We determined the time-averaged and space-averaged structures of supersaturated aqueous sodiumpentaborate solutions by rapid liquid X-ray diffractometry at 298 and 323 K. Difference radial distribution functions (DRDF) and their theoretical partial radial distribution functions for B-B, B-O, O-O, Na-O and Na-B atom pairs were obtained from accurate diffraction data. The effects of concentration and temperature on the structure of the solutions were also discussed. Three main species (B₃O₃(OH)^- ₄, B₅O₆(OH)^- ₄ and B(OH)₃) were found to exist in supersaturated aqueous sodium pentaborate solutions and their hydrated structures were determined by model design and quantitative calculations. Higher temperature and higher concentration result in higher polyborates. As the concentration decreases, interaction distances and the average coordination number of the octahedral hexahydrated Na⁺ ion hardly changes while the hydration number of the polyborate increases. In concentrated solutions, the terminal-oxygen of the polyborates connects with the hydrated Na⁺ in a monodentate formto produce a contact ion pair with a characteristic distance of 0.328 nm.

H-atom abstraction and H₂O production channels for the reaction of O^- with CH₃F were reinvestigated using the ab initio molecular dynamics method at the B3LYP/6-31₊G(d,p) level of theory and based on the Born-Oppenheimer approximation. The reactive trajectories were initiated at the transition state of H-atom abstraction. Thermal sampling at 300 K was chosen to determine the initial conditions. Additionally, the energies added to the transition vector of the barrier were restricted to 2.1, 36.8, and 62.8 kJ·mol ^-1, separately, to reveal the impact of different initial collision energies on the reaction pathways. The results of all the trajectory calculations demonstrate that the H-atom abstraction channel is the dominant production channel. Therefore, our calculations are consistent with previous experimental conclusions. Furthermore, the dynamic reaction pathways for H-atom abstraction and the H₂O production channels on the exit-channel potential energy surface are described based on our calculations and thus a comprehensive reaction mechanismis revealed at the microscopic level.

Platinum-selenium and platinum hollow nanospheres (denoted as (Pt-Se)_HN and Pt_HN, respectively) with different coverages of Se (θ_Se) (θ_Se=0.49, 0.39, 0.06, 0) were prepared using amorphous Se colloids as a sacrificial template. Sulfite was used to completely remove Se from the core-shell nanoparticles. The morphology and structure of the nanoparticles were characterized using various methods, which revealed a hollow structure with a very uniform size distribution and a porous structure on the shell. Assembly of Pt-Se hollownanospheres ((Pt-Se)_HN) on a glassy carbon (GC) electrode produced a (Pt-Se)_HN/GC electrode. The electrocatalytic activity of the electrode for the oxidation of formic acid was compared with the Pt_HN/GCand commercial Pt/C/GCelectrodes by cyclic voltammetry and chronoamperometry. The activity followed the order: (Pt-Se)_HN/GC > Pt_HN/GC >Pt/C/GC. The electrooxidation of formic acid on (Pt-Se)_HN/C, Pt_HN/C, and Pt/C catalysts follows different mechanisms: the former tends to directly oxidize formic acid to CO₂ via weakly adsorbed intermediates, and the latter two via both weakly and strongly adsorbed intermediates. (Pt-Se)_HN with a suitable seleniumcontent showed optimal electrocatalytic activity for the oxidation of formic acid.

WO₃ films were prepared using ammonium metatungstate as the precursor and polyethylene glycol 1000 as the structure-directing agent by the polymeric precursor method. The obtained materials were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible (UV-Vis) spectrophotometry. The photoelectrochemical properties of the WO3 film electrodes were studied by cyclic voltammetry, Mott-Schottky, transient photocurrent spectra, and photocurrent-potential curve analysis. Results indicate that the films are crystalline with a cubic structure and they have bandgap energy of 2.7 eV. The flat band potential, donor carrier density, and photocurrent density of the sample calcined at 450 ℃ are 0.06 V, 2.44×10²² cm^-3 and 2.70 mA·cm^-2 under a 500W Xe lamp (I₀=100 mW·cm^-2), respectively. The effect of calcination temperature on the photoelectrochemical properties of the WO₃ films was investigated and the mechanismof charge separation for its behavior was also discussed.

A TiO₂ film was synthesized on the surface of a Ti substrate by a hydrothermal method, followed by acid treatment and calcination. The properties of the TiO₂ film were characterized by scanning electron microscopy, X-ray diffraction, and ultraviolet-visible spectrophotometry. The photogenerated cathodic protection properties of the TiO₂ film were investigated by electrochemical techniques. The corrosion performance of 403 stainless steel coupled to a TiO2 film photoanode in different solutions was evaluated by photogenerated potential and electrochemical impedance spectroscopy. The results showed that the TiO2 film was composed of many randomly-oriented anatase nanowires of about 10 nm in diameter. The TiO₂ nanowire film prepared by the hydrothermal reaction at 150 ℃ for 6 h was used for the photogenerated cathodic protection of 403 stainless steel. When we coupled the steel in a 0.5 mol·L^-1 NaCl solution to the TiO₂ film photoanode in a mixed solution containing 0.3 mol·^-1 Na₂SO₄ and 0.5 mol·L^-1 HCOOH, its potential decreased by 545 mV. Additionally, the charge transfer resistance of the electrode reaction process for the coupled steel decreased considerably. The results also indicated that the HCOOH in the mixed solution improved the photogenerated cathodic protection of the TiO₂ filmphotoanode.

The long-term effects of four kinds of amine-alcohol based inhibitors on the corrosion behavior of steel rebar inside mortar specimens immersed in saturated NaCl solution were studied by electrochemical impendence spectroscopy (EIS), half cell corrosion potential (E_corr), and macrocell corrosion current density (I_corr) measurements. We found that the E_corr and the impedance modulus were higher than those in the control specimen after inhibitor addition. Additionally, I_corr decreased over the initial 100 d of immersion revealing that the steel rebar electrodes are kept in passive state and the inhibitors showed od inhibition effects. With an increase in the immersion time, E_corr and the impedance modulus for all the inhibited mortar specimens decreased while I_corr increased. After immersion for 125 d there were no obvious differences between E_corr and I_corr for the inhibited systems by comparison to those in the blank sample, except for the specimen containing CI-4. This suggests that the surface of the electrode changes from passive state to active state. The best inhibition was obtained in the presence of the CI-4 inhibitor. We briefly discuss the inhibition mechanismbased on the competitive adsorption of the inhibitor molecules with Cl^- on the steel rebar surface.

Electrochemical methods including polarization curves, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) were used to characterize and investigate the electrochemical behavior of rusted carbon steel immersed in seawater. Results indicate that the inner rust layer that forms on the surface of the carbon steel after long-term immersion greatly affects the electrode process. Polarization resistance (Rp), determined by LPR and EIS, increases during the initial immersion period. After long-term immersion, it decreases. Rp initially increases and then decreases gradually with immersion time. The electrochemical characteristics of the rusted carbon steel were studied by removing the outer and inner rust layers. The materials were analyzed by Fourier transform infrared (FTIR) spectroscopy and their cross-sectional morphologies were obtained to determine the cause. The results show that the β-FeOOH, which exists in the inner rust layer, has high electrochemical activity. Its content increases with the growth of the inner rust layer. In the electrochemical tests, even a small amount of polarization allows β-FeOOH to participate in the cathodic reduction reaction. Besides the anodic dissolution of iron and the cathodic reduction of oxygen, rust reduction is also possible. For this reason, the cathodic reaction rate is promoted and Rp decreases.

We studied the anodic potential, corrosion rate, and anodic passive layer of a flat plate Pb-Ag (0.8% (mass fraction, w) anode over a long period of polarization under different current densities. Additionally, the cathode current efficiency and quality of the zinc product in the ZnSO₄-MnSO₄-H₂SO₄ electrolyte were also studied. The morphology of the anodic passive layer was characterized by scanning electron microscopy (SEM). The results show that the current density greatly affects the electrochemical behavior of the anode and the cathode during zinc electrowinning irrespective of Mn²⁺. With an increase in the current density, the anodic potential, corrosion rate, cathode current efficiency, and quantity of anode slime increased while the Pb content in the zinc product decreased. When the current density decreased from 500 to 200 A·m^-2 in the ZnSO₄-MnSO₄-H₂SO₄ electrolyte, the stable anodic potential and the corrosion rate decreased by 64 mV and 40%, respectively. Under a lower current density, the anodic potential stabilizes more easily and the passive layer that forms on the surface of the anode is denser and it adheres better to the base body, which is advantageous for the reduction of the corrosion rate. Therefore, to reduce the anodic potential, corrosion rate, and the quantity of anode slime, increase the cathode current efficiency and quality of zinc product, we suggested that the ideal working condition for zinc electrowinning is a higher cathodic current density and lower anodic current density.

Ni, Ni-Fe, and Ni-Fe-C alloy electrodes were prepared by electrodeposition. Polarization curves showed that the Ni-Fe-C alloy electrode shows the best electrocatalytic activity for the hydrogen evolution reaction (HER) in a simulated seawater solution (0.5 mol·L-1NaCl, pH=12) at a temperature of 90 °C. The effect of morphology, composition and crystal structure on hydrogen evolution was studied by scanning electron microscope (SEM), X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM).We found that the grain size of the electrodes affect their electrocatalytic activity for the HER. A smaller grain size benefits the catalytic performance. Electrochemical impedance spectroscopy (EIS) indicated that an increase in active sites and intrinsic electrocatalytic activity is important for a major increase in the electrode catalytic activity for the HER.

N-ferrocenoyl-labeled tripeptide Fc-Gly-Pro-Arg(NO₂)-OMe(Fc-GPR) was synthesized from ferrocene-carboxylic acid, glycine (H-Gly-OMe), proline (Boc-Pro-OH) and arginine (H-Arg(NO₂)-OMe) by solution synthesis with a yield of 48.1%. The synthesized Fc-GPR was characterized by infrared spectroscopy (IR), proton nuclear magnetic resonance spectroscopy (¹H-NMR) and electrospray ionization mass spectroscopy (ESI-MS). The electrochemical behavior of Fc-GPR was investigated using electrochemical methods. We observed a pair of well-defined voltammetric peaks with cathodic E_pc and anodic peak potentials E_pa, at 0.552 and 0.624 V (vs Ag/AgCl), respectively. The ratio of oxidative to reductive peak current is 1.13 and the peak currents were found to be proportional to the square root of the scan rates suggesting that Fc-GPRunder es a reversible electron transfer reaction. The molar ratio of Fc-GPR to Cu(II) was found to be 2:1 by the molar ratio method. Furthermore, the electrode reaction of Fc-GPR with Cu(II) is an electrochemical-chemical-electrochemical (ECE) process.

We prepared nanosized hydroxide magnesium (Mg(OH)₂) as a plasticizer and a flame-retarding additive for a poly(ethylene-oxide) (PEO) based polymer electrolyte. We characterized the prepared compound using transition electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetry (TG). The prepared hydroxide magnesium particles are hexa nal crystals with sizes of 50-80 nm. The decomposition of the prepared nanosized hydroxide magnesium started at 340 ℃. Electrochemical measurements shows that the ionic conductivity of the Mg(OH)₂/PEO composite polymer electrolytes (CPEs) increases initially and then decreases with an increase in hydroxide magnesium content. It reaches a maximum when the hydroxide magnesium mass fraction is between 5% and 10%. The anodic decomposition potential of the CPEs increases to a certain extent as the hydroxide magnesium content increases. Hydroxide magnesiumhas a positive influence on the electrochemical stability of PEO.

The initial stages of the anodization of aluminum are influential during the preparation of anodic aluminum oxide nanotemplates and provide an insight into their formation mechanism. The formation and development of both the barrier layer and the porous layer are involved. In this paper, in situ ellipsometric spectra with a high time-resolution were collected. To deconvolute the ellipsometric spectra, several optical models were extracted from the physical models of the Al-H₂SO₄ interface. Using these models and the effective medium approximation, detailed information about the composition and thickness of the Al₂O₃-Al interphase, Al₂O₃ barrier layer, and porous layer was acquired. Based on the deconvoluted results and the optical models, 4 stages of the porous anodization of aluminum, i.e., the barrier layer grows, pores form, pores enlarge, and pores grow at a stable rate, were clearly distinguished. Moreover, during the last stage the thickness of the porous layer changes linearly with time at a rate of 5.8 nm·s^-1 while both the thickness of the barrier layer and the porosity of the porous layer change very little.

Changes in phase structure, hydrogen storage and electrochemical properties of the (Ti Cr)_0.497V_0.42Fe_0.083+ 30% (w) (LaRMg)(NiCoAl)_3.5 alloy after treatment by ball-milling for different time (t=0, 0.5, 1, 3, 5, 10 h) were investigated systematically. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) showed that the particle size of the milled composite samples decreased gradually and the powder appears aggregated. The A₂B₇ alloy particles were uniformly dispersed and encapsulated on the surface of the V based alloy particles that were formed after increasing the ball-milling time. It was found that nanocrystalline composites were formed and partial amorphization occurred when the milling time was more than 5 h. The crystal parameter a and the cell volume V of the BCC phase structure in the composite both showed a decrease. Hydrogen storage capacity of the single V based alloy was 3.11%(w), with an increase in milling time hydrogen storage capacity of the milled composites decreased and the maximum hydrogen absorption capacity at room temperature approached 2.47%(w). Electrochemical studies showed that the electrochemical properties of the milled composite were enhanced and the maximum discharge capacity was 425.8 mAh·g^-1. The cyclic stability of the composite electrode improved noticeably. After 100 charge-discharge cycles the discharge capacity retention rate C₁₀₀/C_max of the milled composite electrode was 97%, and it had a better cycle life than that of the A₂B₇ type alloy electrode.

The electrochemical properties of three carbon-based electrodes including boron-doped nanocrystalline diamond (BDND), boron-doped microcrystalline diamond (BDMD), and glassy carbon (GC) were compared. We used scanning electron microscopy to characterize the two diamond electrodes and the grain sizes of the BDMD and BDND films were 1-5 μm and 20-100 nm, respectively. The phase composition was characterized by Raman spectroscopy and high-quality BDMD and BDND films were formed by hot-filament chemical vapor deposition. Cyclic votammograms for 0.5 mol·L^-1 H₂SO₄ showed that the potential windows for the BDND and BDMD electrodes were 3.3 and 3.0 V, respectively. The potential windows were much wider than that of the GC electrode (2.5 V). The cyclic voltammograms and Nyquist plots of the impedance measurements for [Fe(CN)₆]³-/[Fe(CN)₆]⁴- show peak to peak separations (ΔE_p) of 73, 92, and 112 mV and electron transfer resistances (R_et) of (98依5), (260依19), and (400依25) Ωfor the BDND, BDMD, and GC electrodes, respectively. We also investigated the oxidation of 0.1 mmol·L-1 bisphenol A (BPA) on the three carbon-based electrodes. The above-mentioned electrochemical results reveal that the two diamond electrodes have wider potential windows, better reversibility, faster electron transfer, and higher stability than the GC electrode. Additionally, the BDND electrode shows better electrochemical properties than the BDMD electrode.

A novel energetic coordination complex of [Mn(AZT)₂(H₂O)₄] (HTNR)₂·4H₂O (AZT=3-azido-1,2,4- triazole, HTNR=2,4,6-trinitro resorcinol) was prepared by the reaction between the acidic manganese (II) salt of 2,4,6-trinitro resorcinol and AZT in an aqueous solution. The complex was characterized by elemental analysis and FTIR spectroscopy. The molecular structure was determined by X-ray single crystal diffraction. The crystal belongs to the triclinic systemwith a Pī space group. The central manganese(II) cation has a slightly distorted octahedron feature. Three-dimension networks were formed and the layers are linked by extensive hydrogen bonding. The thermal decompositionmechanismof [Mn(AZT)₂(H₂O)₄] (HTNR)₂·4H₂O was predicted based on differential scanning calorimetry (DSC) and thermogravimetry-derivative thermogravimetry (TG-DTG) analyses. One endothermic peak and three exothermic peaks are present during the thermal decomposition process with the final residue at 600 ℃being MnO and MnO₂. The kinetic parameters of the exothermic process for the complex were studied using Kissinger's and Ozawa- Doyle's methods. Furthermore, impact sensitivity, flame sensitivity, and friction sensitivity tests reveal that the title complex is sensitive and selective towards external stimulants.

We prepared V₂O₅ /CeO₂ catalysts with different V₂O₅ loadings (5% and 15%) by incipient wetness impregnation. Raman spectroscopy (514 and 325 nmexcitation laser lines), X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and N₂ adsorption were used to study the solid-state reaction between V₂O₅ and CeO₂. We found that the vanadium oxidation species reacted with ceria and formed a CeVO₄ phase on the surface of the sample that was calcined at 300 ℃, and the reaction was promoted at higher temperature. In addition, the absorption at 325 nm is stronger than that at 514 nm for the sample, therefore, 325 nm Raman spectroscopy is more sensitive to surface information than 514 nm Raman spectroscopy. Calcination at low temperature leads to unreacted V₂O₅ in the pores of CeO₂ but this is hindered by CeVO₄ on the sample surface. Therefore, the Raman band of V₂O₅ is present when using the 514 nmexcitation laser line and absent when using the 325 nmexcitation laser line.

A porous and hydroxyl group-rich catalyst RuB/SiO₂·xH₂O was prepared by hydrolyzing ethyl silicate, protecting SiO₂·xH₂O with polyvinyl pyrrolidone (PVP), and etching SiO₂·xH₂O with NaOH. The catalyst was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier transforminfrared (FT-IR) spectroscopy, and BET (Brunauer-Emmett-Teller). We found that the catalyst showed excellent performance for the hydrogenation of quinoline under mild condition. At a hydrogen pressure of 3.0 MPa and a reaction temperature of 80 ℃, the conversion of quinoline reached 95% and the selectivity for 1,2,3,4- tetrahydroquinoline was 97%. This porous catalyst also showed an excellent anti-poisoning characteristic. The catalyst can be reused several times. We also investigated the effect of surface hydroxyl groups and the solvent on catalytic activity and selectivity. The results showed that using water as a solvent leads to higher catalyst activity and selectivity for the hydrogenation of quinoline. The mechanism of quinoline hydrogenation over the catalyst is discussed. The coordination of the nitrogen on quinoline onto the surface of ruthenium nanoparticles, the effect of hydrogen bond among the surface hydroxyl groups of the catalyst and the nitrogen present in quinoline and in the water solvent were favorable for the adsorption of the substrate and the desorption of the products fromthe surface of the catalyst.

We added modified sepiolite to a polypropylene (PP)/ammoniumpolyphosphate (APP)/di-pentaerythritol (DPER) composite to study the effect of sepiolite on the retarding behavior of the intumescent flame retardant (IFR) PP flame. The flame retarding behavior of the PP/IFR composite was tested using the limiting oxygen index (LOI) and cone calorimeter tests (CONE). The results show that sepiolite increases the LOI value of the PP/IFR and it is more effective than other nano-fillers such as layered double hydroxides (LDH) and organic montmorillonite (OMMT). The sepiolite decreases the heat release rate (HRR) and the total heat release (THR) of the PP/IFR composite. The flame- retardant mechanism of the PP/IFR/sepiolite system is also discussed in terms of catalytic charring after analysis by thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). For the binary APP/DPER mixture, sepiolite reduces the mass loss rate and increases the amount of residue at high temperature under nitrogen and air atmospheres. This has been considered to be strongly associated with the interaction between sepiolite and APP. FTIR and XPS results show that the P—O—Si bond forms at high temperature for binary mixtures of APP/sepiolite. With the addition of sepiolite to the PP/IFR, the char residue burnt is dense and homogeneous, which is important for the flame retardant performance.

Hexa nal mesoporous silica (HMS) was synthesized using dodecylamine (DDA) or octadecylamine (ODA) as templates which were then removed by calcination or extraction. Characterization data of HMS from XRD and N₂ adsorption-desorption proved that the optimized material were typical mesoporous materials based on the facts that the XRDdiffraction peak displayed apparently the feature of mesoporous materials and the N₂ adsorption-desorption curve was typical of a type IV isothermand contained a type H1 desorption hysteresis loop. These novel photocatalysts had a BET surface area of 675.1 m²·g^-1, an average pore diameter of 5.78 nm and a BJH pore volume of 0.587 cm³·g^-1, and were prepared by the F—C reaction between functionalized HMS and iron sulfophthalocyanine (FePcS). Additionally, the catalysts preserved an undamaged heavy mesoporous structure. Upon the irradiation of the simulated visible light, these novel catalysts were applied to the degradation of simulated phenol wastewater at a concentration of 1000 mg·L^-1. The conversion of phenol reached 85%and the pH decreased from the original 4.52 to 2.65 after reaction time of 400 min, which indicated that acid intermediates were produced during the photocatalysis of phenol. Finally, the conversion rate of phenol was nearly 100% and the total organic carbon (TOC) removal rate exceeded 81%. The novel catalyst is, therefore, highly effective for the degradation of phenol.

Metal-doped xerogels were synthesized by the sol-gel method and their catalytic performance was evaluated for the catalytic ozonation of simulated micro-polluted water containing ortho-dichlorobenzene (o-DCB). The obtained samples were characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), mercury porosimetry and nitrogen adsorption. Results show that Fe³⁺ oxides and Mn³⁺ oxides are present in the Fe-doped xerogel (XFe) and the Mn-doped xerogel (XMn), respectively. No obvious diffraction peaks corresponding to a metallic phase were present in the XRD patterns of the xerogels. Also, the metallic particles were found to be small; therefore, the metallic particles were well distributed over the xerogel supports. Catalytic ozonation experiments indicated that the removal rate of o-DCB was 44% with single ozonation, and this increased to 58% and 72% with catalytic ozonation using XFe and XMn, respectively, which suggests that metal-doped xerogels are promising catalysts for the ozonation process. We also investigated metal leaching from the metal-doped xerogel to the water solution to test the stability of the catalysts, and about 2%and 8%metal leaching for XFe and XMn was obtained within 5 h.

MnO_x-CeO₂/WO₃/ZrO₂-TiO₂monolithic catalyst was prepared by ZrO₂-TiO₂ as support, MnO_x-CeO₂ as active components and WO₃ as the promoter. The influence of the different mass fractions (w) of WO₃ on the NH₃-selective catalytic reduction (NH₃-SCR) of NO_x performance at low temperature was studied. The catalysts were characterized by N2 adsorption-desorption at low temperature, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and NH₃ temperature-programmed desorption (NH₃-TPD). The experimental results showed that, compared with the catalyst without WO₃, the catalyst with 10.0% (w)WO₃ had od texture properties, middle strong acid sites, and higher O_xidation performance. The results of activity test showed that the monolith catalyst had not only od catalytic activity at low temperature but also a wide activity temperature window. The NO_x conversion is more than 90%in the temperature range of 144-374^oC at the space velocity of 10000 h^-1. It shows potential application in de-NO_x at low-temperature.

Many microorganisms can adsorb metal ions strongly and even reduce them to their metal states. We studied the adsorption of ld nanoparticles on Escherichia coil (DH5α) to form Au@DH5α. Titanium tetrabutoxide was added to Au@DH5αto prepare Au@DH5α-Ti(OH)₄ by hydrolysis. The DH5αtemplate was removed by calcination in air to obtain the Au@TiO₂ catalyst. These materials were characterized by N₂ adsorption, X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), thermogravimetry-differential thermal analysis (TG-DTA), and transmission electron microscopy (TEM). The results show that the ld catalyst maintains a rod-like structure similar to DH5αand the porous structure of the titanium oxide prepared using DH5αas a biological template can prevent the aggregation of ld nanoparticles to some extent. With higher amounts of DH5αdosage, smaller ld nanoparticles were obtained and the surface plasmon absorption of ld nanoparticles shifted toward shorter wavelengths. The obtained ld catalyst has a larger surface area than the catalyst prepared by the impregnation method. However, this increases the coke content of the catalyst. Catalytic activity was evaluated by the CO oxidation reaction. We found that with a DH5αdosage of 100 or 150 mL, the obtained ld catalyst can convert CO to CO₂ completely at 80 ℃.

We prepared a TiO₂-Al₂O₃ complex support by the sol-gel method. A nickel phosphide catalyst, Ni₂P/ TiO₂-Al₂O₃, was prepared by the impregnation method. The catalysts were characterized by X-ray diffraction (XRD), N₂-adsorption specific surface area measurements (BET), thermogravimetry-differential thermal analysis (TG-DTA), and X-ray photoelectron spectroscopy (XPS). The catalysts were evaluated using a lab-scale continuous flow fixed-bed reactor for simultaneously hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of thiophene and pyridine. The effects of different supports, Ni₂P loading, Ni/P molar ratio, and calcination temperature on catalyst activity for the HDS and HDN were studied. The catalytic activity of the Ni₂P/TiO₂-Al₂O₃ catalyst with a TiO₂ mass fraction of 80%, a Ni₂P loading of 30.0%(w), a Ni/P molar ratio of 1/2 as well as a calcination temperature of 500^oCwas found to be optimal. At a reaction temperature of 360 ^o, a pressure of 3.0 MPa, a hydrogen/oil ratio of 800 (V/V), and a liquid hourly space velocity of 1.5 h^-1, the conversion of thiophene HDS and pyridine HDN were 61.32%and 64.43%, respectively.

The colors of Au nanoparticles (Au NPs) change along with conformational changes in cytochrome c (Cyt c). We exploited this property for the colorimetric detection of Cyt c conformational changes induced by H⁺ and L-cysteine (L-Cys). We improved the conventional procedure for this detection. After the addition of Cyt c within different pH values, the Au NPs are either cyan, blue, purple or red. This indicates that the Au NPs can be applied to the rapid colorimetric detection of pH-induced conformational changes in Cyt c. At pH 7 the color of Au NPs changes from purple to blue and then cyan upon the addition of L-Cys, which suggests that the Au NPs can be used for the colorimetric detection of Cyt c conformational changes caused by interaction with L-Cys. The conformational changes of Cyt c were verified by circular dichroism (CD) spectroscopy. The relationship between the aggregation states and colors of the Au NPs after the addition of Cyt c was characterized by UV-Vis absorption spectroscopy and scanning electron microscopy (SEM).

We studied the effects of salts on the microstructure of liquid methanol using the Raman spectra. We compared the excess Raman spectra of different methanolic salt solutions in the O—H and C—O stretching regions. These regions reflect the interactions between anions (cations) and methanol molecules. In the O—H stretching region, the excess spectra show that the anions interact with methanol molecules by weak hydrogen bonding and the strength of the hydrogen bonds decrease according to the order: CH₃OH-CH₃OH>Cl--CH₃OH>NO- ₃ -CH₃OH>ClO- ₃ -CH₃OH. Additionally, no interactions between cations and methanol molecules are apparent, as determined after analysis of this region. In the C—O stretching region, the excess Raman spectra show the interactions between anions (cations) and methanol molecules. The C—O stretching vibration frequencies of methanol that interact with the anions and cations increase according to the order: CH₃—OH (anions)3—OH (bulk)3—OH (cations). According to the excess Raman spectra in the C—O stretching region, we fitted the Raman spectra and used the fitting results to determine the solvation numbers in the first solvation shell of the ions. The Raman spectra show that the ions do not affect the microstructure of liquid methanol beyond the first solvation shell at this concentration (~0.005).

The quenching reactions of triplet thioxanthone (TX) by a series of amines, phenols, and alcohols were investigated by laser flash photolysis in deoxygenated acetonitrile. We obtained corresponding transient absorption spectra and quenching rate constants (k_q). Fromchanges in the transient absorption spectra, we determine that the electron transfer reactions occur between triplet TX and amines without an active hydrogen while electron/proton transfer reactions occur between triplet TX and amines with an active hydrogen. The appearance of hydrogenated radicals can be regarded as evidence for hydrogen transfer reactions in the TX/phenol and TX/alcohol systems. In the TX/amine systems, the quenching rate constants decreased with an increase in the free energy change (ΔG). This indicates that electron transfer reactions influence the quenching of triplet TX. In the TX/phenol systems, the quenching rate constants decreased with an increase in ΔG firstly, then increased with an increase in phenol cation acidity. This can be explained by considering that charge transfer and hydrogen transfer may play separate but important roles. In the TX/ alcohol system, the quenching rate constants decreased with an increase in the α-C—H bonding energy of alcohols, and this indicates that the α-C—H bonding energy is a key factor during triplet TX quenching. By comparison with previous studies about the quenching reactions of triplet xanthone (XT) and fluorenone (FL) by a series of amines, phenols, and alcohols, it is established that because of a discrepancy in molecular configurations the quenching rate constants decrease according to the following order: XT, TX, and FL.

The influence of pyrite irradiated by γradiation from ⁶⁰Co on the reductive environment of groundwater was investigated. The dose rate was 200 Gy·min^-1 and the total absorbed dose was 5×10⁶ Gy. Our results indicate that the radiolysis reactions of the γradiation of ⁶⁰Co in groundwater can help to oxidize pyrite, while the structure of pyrite is not changed. The oxidizing of pyrite consumes the radiolysis product in groundwater, which helps to maintain a reductive environment and increase the safety of the repository.

A quantitative structure-property relationship (QSPR) study on the solubility of 84 organic compounds in 4 different ionic liquids was done based on VolSurf parameters using the partial least square (PLS) statistical method and od results were obtained. The training set model predicts the solubilities of the test set well. An analysis of the VolSurf descriptors show that large volume hydrophilic regions are beneficial for solubility, and the interaction energy is about -0.84 kJ·mol^-1 between the organic compounds and the ionic liquids. A certain degree of hydrophobicity is also favorable for solubility. When the ionic liquids have a small hydrophobic substituent, an asymmetric partial hydrophobic region in the organic compound is advantageous for solubility. If the ionic liquid has a large hydrophobic substituent, a large hydrophobic region in the organic compound benefits the solubility. Multiple linear regression (MLR) analysis shows that hydrophilic parameterW1 is the most important parameter, which indicates that hydrophilicity is a key factor that influences the solubility of organic compounds in ionic liquids.

The adsorption properties of linear C₂-C₅ olefins on HY and H-ZSM-5 zeolites were studied by the ONIOM(B3LYP/6-311++G(d,p):UFF)method. The results indicate that microcosmic interactions of the olefin molecules with the Br?nsted acid sites of the zeolites lead to the formation of π-complexes. The adsorption energies of olefins on zeolites increase with an increase in the number of carbon atoms, and the amount of increase is approximately constant (HY zeolites: ca 12 kJ·mol^-1; H-ZSM-5 zeolites: ca 25 kJ·mol^-1), which agrees well with the adsorption properties of alkanes on zeolites. The position of the double bond has a fairly large effect on the adsorption energies of olefins. The adsorption energies of 2-olefins are much higher than those of 1-olefins. The adsorption energies of olefins on the different types of zeolites also show a significant difference. The adsorption energies of olefins on small pore H-ZSM-5 zeolites are much larger than those on large pore HY zeolites. Furthermore, the confinement effect in the different types of zeolites is more obvious when the number of carbon atoms increase. From the microstructure, the distance between the adsorbent molecule and the acidic proton in the H-ZSM-5 zeolite is much bigger than that between the adsorbent molecule and the acidic proton in the HY zeolite. These are mainly attributed to differences in the van der Waals interactions for the different types of zeolites, and the small pore zeolites have much stronger van der Waals interactions. Frontier orbital calculations indicate that the catalytic activity of the large pore HY zeolite is similar for small olefins while the catalytic activity of the small pore H-ZSM-5 zeolite decreases slightly with increasing carbon number.

The growth pattern and magnetic properties of the Ge_nEu (n=1-13) clusters have been investigated using the density functional theory within the generalized gradient approximation. For all the ground state structures of the Ge_nEu (n=1-13) clusters, Eu atomalways prefers to cap on the surface of the germaniumframe, which is different from the growth pattern of the SinEu cluster and other transition metal-doped semiconductor clusters. The total magnetic moments of the Ge_nEu clusters have a constant value (7μB) except the GeEu cluster. The total magnetic moment of the Ge_nEu clusters are mostly equal to the local magnetic moment of the 4f state of the Eu atom. Although charge transfer between Ge and Eu as well as hybridization among the 5d, 6p, and 6s states of Eu atom can enhance the local magnetic moment of Eu, it does not enhance the total magnetic moment of the Ge_nEu clusters.

Benzanthrone derivatives show great potential for use as new luminescent, nonlinear optical, and liquid crystalline materials. The geometries of the ground and the first excited states of 3-pyrrolidinobenzanthrone were optimized using quantum chemistry methods and the obtained structural parameters were compared with experimental data. The time-dependent density functional theory (TD-DFT) calculations were performed to estimate the absorption and emission spectra of 3-pyrrolidinobenzanthrone both in gas-phase and in solutions. In addition, the effects of different exchange correlation functionals, basis sets, and solvents on the absorption and emission spectra were analyzed in detail. We found that the strongest absorption and emission bands of 3-pyrrolidinobenzanthrone could be assigned to a charge transfer (CT) state with a π→π^*character. The result of the B3LYP functional reproduces the experimental absorption spectrum very well and the MPWK functional accurately predicts the emission energy of the first excited state with an intramolecular charge transfer (ICT) feature. The calculated results indicate that solvent effects do not greatly influence the absorption and emission spectra. The theoretical results are in agreement with experimental observations.

Orbital electron momentum spectroscopies for saturated alkanes C_nH_2n+2(n=4-6) were systematically studied using the B3LYP/TZVP//B3LYP/aug-cc-pVTZ model. The effect of saturated alkanes C_nH_2n+2(n=4-6) isomers on orbital momentum distributions was analyzed. Electronic density distributions of coordinate space were systematically investigated by dual space analysis. The results indicate that the innermost valence orbitals are s-dominated whereas the next innermost valence orbitals exhibit p-dominant orbital profiles. The other valence orbitals are sp-mixed because of strong chemical bonding. The relative intensity of innermost valence orbitals is far larger than that of other orbitals. Furthermore, the relative intensity of n-alkane is larger than that of iso-alkane, which indicates that there is an obvious correlation between the relative intensity and the number ofmigratedmethyls.

To improve the carrier-injection of polyfluorene, oli mers of polyfluorene, fluorene-bipyridine, and fluorene-phenanthrolin copolymers were theoretically studied for their geometries, electronic structures, excitation energies, and reorganization energies by density functional theory at the B3LYP/6-31Glevel. We evaluated the properties of the corresponding polymers by linear extrapolation. We found a large decrease of about 0.45/0.47 eV and 0.32/0.38 eVfor the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) levels, respectively, after the introduction of electron-deficient bipyridine/phenanthrolin into polyfluorene. These molecules improved the electron injection ability and the balance of carrier-injection in polyfluorene systems. Additionally, the reorganization energy increased for both electron and hole transports upon the incorporation of bipyridine, which resulted in worse carrier mobility. However, the fluorene-phenanthrolin copolymer showed a similar charge transport property to polyfluorene.

A number of density functional theory (DFT) methods were compared for the calculation of N—O bond dissociation enthalpies (BDEs) with the experimental values on the basis of the high-precision calculation methods G3 and G3B3. We found that the B3P86 method gave the lowest root of mean square error of 6.36 kJ·mol^-1 for calculating N—O BDE of 15 molecules and the correlation coefficient between the theoretical and experimental values was 0.991. We, therefore, used this method to calculate the N—O BDEs of non-aromatic and aromatic compounds. Using natural bond orbital analysis, quantitative relationships between some N—O BDEs and the corresponding N—O bond lengths, atomic charges, bond orders were determined. In addition, we predicted the N—O BDEs of several typical heterocyclic aromatic compounds using the B3P86 method.

Density functional theory (DFT) and quadratic configuration interaction with single and double excitations (QCISD) methods were used to investigate the geometries of the triplet silylenoid HB=SiLiF as well as its insertion reactions with RH (R=F, OH, NH₂). The calculated results indicated that HB=SiLiF has three equilibrium structures wherein the four-membered ring structure had the lowest energy and it was the most stable structure. The mechanisms of the insertion reactions for HB=SiLiF with HF, H₂O, and NH₃ were identical. The QCISD/6-311++G(d,p)//B3LYP/ 6-311+G(d,p) calculated potential energy barriers of the three reactions were 124.85, 140.67, and 148.16 kJ·mol^-1, and the reaction heats for the three reactions were -2.22, 20.08, and 23.22 kJ·mol ^-1, respectively. Under the same conditions, the insertion reactions should occur easily according to the following order: H—F>H—OH>H—NH₂.

Some natural products from traditional Chinese medicine (TCM) such as flavones and resveratrol have been reported to have thromboxane A2 receptor (TP) inhibiting activity.We investigated a possible inhibition mechanism by a homology model of TP, which was built based on the crystal structure of squid rhodopsin. After that, docking methods were used to investigate the binding modes of resveratrol and apigenin in the active pocket of TP. Furthermore, a three- dimensional pharmacophore model was generated for screening other potential natural TP inhibitors. The results indicate that resveratrol and apigenin bind to the active site of TP similar to the way that thromboxane A2 binds to Ser201, Leu198, Arg295, and Thr298. The former three key residues can form hydrogen bonds with the inhibitors. The pharmacophore model consisted of seven features and a set of volume spheres, which has been proven to be efficient in identifying compounds with high TP inhibition activity. In this way, a set of potential TP inhibitors were screened from a natural product database. Some of them were reported to have platelet aggregation inhibiting activities. This research indicates that TP could be an important target of TCMdrugs with blood circulation activation effects.

Cu₇S₄ nanotubes were synthesized using a biomolecule DL-methionine-assisted hydrothermal method. The morphology and phase of the products can be controlled by adjusting the reaction parameters such as synthesis temperature, reaction time and the molar ratio of the reagents. We found that uniform polycrystal Cu₇S₄ nanotubes with diameters of 100-600 nm and lengths of 40-100 μm can be controllably synthesized at 200^oC when the molar ratio of Cu(NO3)2 to DL-methionine in the synthesis system is 1:2. Similar Cu₇S₄ nanotubes can be obtained from D-or L- methionine systems. The bandgap energy of the Cu₇S₄ nanotubes was measured to be about 2.88 eV, a remarkable blue shift in comparison with that of bulk Cu₇S₄ (2.0 eV). We discussed the relationship between the products and the functional groups in the amphiphilic biomolecules. On the basis of our experimental data, we proposed that the Cu₇S₄ nanotubes were formed versus a self-sacrificing template mechanism.

One-dimensional (1D) aligned ZnO nanowire arrays with different morphologies were synthesized by a solution-phase method. The morphology and microstructure of the products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The field emission property of different ZnO nanowire array samples was compared. The factors that influence the field emission property of the 1DZnOnanowire arrays were analyzed using the Fowler-Nordheimequation. The results showed that the ZnOnanowire samples with the lower areal density, higher aspect ratio, and thin tips showed much better field emission characteristics.

Hollowspherical ammoniummetatungstate (AMT), as a precursor, was prepared by an ultrasonic method. Tungsten carbide (WC) was prepared by a gas-solid reaction in an atmosphere of CO/H₂ at 700-900^oC. Microspheres were fractured by ultrasonic dispersion for 1 h. X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry-differential thermal analysis (TG-DTA), Brunauer-Emmett-Teller (BET) surface area, and Barrett- Joyner-Halenda (BJH) pore-size distribution were used to characterize the morphology, mesoporous structure, and thermal stability of the sample. The results indicate that the sample is pure WC. The WC sample is stable in air at 410 ^oC and the mesopores of WC were centered at 4 nm and 22 nm. A WC powder microelectrode (WC-PME) was prepared using the prepared WC powders. The activity of WC for the electroreduction of nitrobenzene was studied by cyclic voltammetry (CV). The results indicate that the bimodal porosity of WC-PME led to higher catalytic activity than that of a Pt micro disc electrode (Pt-MDE). The reduction potential was 30 mV more positive than that of the Pt-MDE. The relation I_p-v^1/2 showed that the electrode reaction was controlled by liquid diffusion.

Well-aligned ZnO/CdS composite nanorod array film was grown on an indium tin oxide (ITO) substrate by two-step chemical solution deposition method. The effects of CdS deposition time on the crystal structure, morphology, and photoelectric performance of the ZnO/CdS composite film were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible absorption spectroscopy (UV-Vis), photoluminescence spectroscopy (PL), and surface photovoltage spectroscopy (SPS). Results showed that the absorbance of the composite film extended into the visible region compared with the bare ZnO nanorod arrays. SPS also showed a new response region corresponding to the absorption spectrum. This result indicated a remarkable photoelectric conversion efficiency improvement in the visible region. We also found that the SPS response intensity of the composite film decreased gradually above 383 nmwith an increase in CdS deposition time. However, the SPS response intensity increased below 383 nm. We interpreted this phenomenon using two distinct photoinduced charge generation and transfer mechanisms.

Chitosan (CS) nanosphere loaded aspirin (aspirin/CS) was prepared by nucleation and ionic crosslinking in an emulsion used for medical and pharmaceutical applications. Chemical component, morphology, size distribution, and crystal structure of nanospheres were characterized by Fourier transforminfrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), dynamic laser light scattering (DLLS), and X-ray powder diffraction (XRD). Results showed that the diameter of a typical aspirin/CS nanosphere is about 88 nm and the distribution is uniform. The crystal structure of CS does not change during the nucleation process. The crystallinity of aspirin is dramatically reduced and aspirin is almost amorphous in the nanosphere. The drug content (mass fraction), the drug loading efficiency, and the in vitro release profiles under different conditions were investigated using UV-Vis spectrophotometry. Results showed that the drug content was about 55%, the drug loading efficiency reached 42%, and the chitosan nanosphere displayed an excellent drug-controlled release behavior under the experimental conditions.