Chlorine anion (Cl-) emission from the synthesized microporous crystal surface of C12A7-Cl- (11CaO·7Al2O3·CaCl2) was observed by time-of-flight mass spectrometry (TOF-MS). We investigated the emission features of C12A7-Cl- (including branching ratios of emission intensity, temperature effect, electric field effect, and apparent activation energy) in detail. The anionic species emitted from the C12A7-Cl - surface were dominant by Cl- anions (maximum branching ratio of intensity: 98%) while a weak O- anion emission and electron emission were also observed. The emission current densities of the anionic species were significantly enhanced by the increase of sample surface temperature or extraction electric field strength. The apparent activation energies for the Cl- emission decreased from 180.9 to 110.0 kJ·mol-1 as the extraction electric field strength increased from200 to 1200 V·cm-1. The binding energy between the Cl- anion and the C12A7-Cl- surface was about 228 kJ·mol-1. The stability of the Cl- emission was also investigated and an electrochemistry implantation method was adopted to obtain a sustainable Cl- emission. We also discussed the formation and emission mechanism of Cl- anions based on the above investigations. This method may be potentially useful to develop a reservoir or generator of Cl- anions.

Indiumdoped ZnO-SiOx core-shell nanocable heterostructures were successfully fabricated by introducing In ions into the raw material via a simple thermal evaporation process. X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS) were used to investigate the structure of the In/ZnO-SiOx core-shell fibers. Results indicated that the core zone of ZnO nanocables is single crystalline In/ZnO with a wurtzite structure and the shell zone is a SiOx amorphous layer. The nanocables have high aspect ratio of more than 100 with widths of 30-60 nm. The growth mechanismof the nanocable heterostructures is different fromthe commonly reported metal-seeded vapor-liquid-solid (VLS) mechanism. The synthesis of core-shell structures reveals the general potential of radial heterostructure growth for the development of nanowire-based devices.

The effect of 4-chlorophenol (4-CP) on the electrochemical activity of Ti-based IrO2 electrodes in acidic aqueous solutions was investigated within the electrochemical window for 4-CP. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements both indicated that the existence of 4-CP in solution resulted in the activation of the IrO2 electrode in the electrochemical window. However, the testing results at metallic Ir electrode showed that the electrode activity was inhibited by 4-CP because of its adsorption onto the metal surface. A possible mechanismis proposed based on the influence of 4-CP on the electrochemical activities of these two electrode materials. The activation of IrO2 is believed to be related to its ease of transition from lower-valent to higher-valent oxides in the electrochemical window. The later oxides can be chemically oxidized and can remove organic molecules that are adsorbed onto the oxide electrode surface.

The pseudo-potential plane wave (PP-PW) method, the local density approximation (LDA) and generalized gradient approximation (GGA) were used to calculate the electronic structures of cubic and tetra nal BaTiO3, respectively. The local density approximation was used to calculate optical properties of cubic BaTiO3. Results show an indirect bandgap of 2.02 eV in the Γ-M direction for the cubic phase and an indirect bandgap of 2.20 eV in the Γ-X direction for the tetra nal phase. For ferroelectric phases, a comparison of shorter bond populations for BaTiO3 and PbTiO3 revealed differences in ferroelectric behavior between BaTiO3 and PbTiO3. Furthermore, the dielectric function, absorption coefficient, refractive index, extinction coefficient, reflectivity, and energy loss coefficient were obtained and analyzed on the basis of electronic band structures for radiation of up to 30 eV. These results are in od agreement with experimental data.

The adsorption and desorption behaviors of Zn(II) on water- ethite interfaces under various particle concentrations (Cp) and temperatures were studied using traditional batch experiments. The Zn(II)/α-FeOOH adsorption system exhibited a significant particle concentration effect, in other words adsorption isotherms decreased as Cp increased. The adsorption also became less reversible because as the Cp increased which was demonstrated by the hysteresis angle (θ) and thermodynamic index of irreversibility (TII) as derived fromadsorption and desorption isotherms. This agrees with the explanation of the particle concentration effect as postulated in metastable-equilibrium adsorption (MEA) theory. Furthermore, the particle concentration effect became more obvious at lower temperatures. Adsorption of Zn(II) on ethite surfaces was found to increase greatly with the increase of temperature and the adsorption became more reversible. These results further confirmed that the Cp effect is the result of changes in adsorption reversibility. The study also showed that the adsorption was a simultaneous (positive △S value of 195.71 J·mol-1·K-1) and endothermic (positive △H value of 34.07 kJ·mol-1) chemisorption process.

To improve the corrosion resistance of silane films further, silanized hot-dip galvanized (HDG) steel was post-sealed with molybdate solution. The surface morphology and corrosion resistance of the composite films were investigated by scanning electron microscopy (SEM), a neutral salt spray (NSS) test, a salt water test, and electrochemical measurements. Results showed that pores in the silane films were filled after post-sealing the silanized HDG steel with molybdate solution. This was accompanied by the formation of a continuous, complete, and compact composite film that was composed of a silane film and a molybdate conversion film on the surface of the HDG steel. The composite coatings have much better corrosion resistance than a single silane film and this is related to the sealing time.  Silanized HDG steel that underwent post-sealing for 60 s in molybdate solution showed the best corrosion resistance. Results of the electrochemical measurements in 5%(w, mass fraction) NaCl solution reveal that both the anodic and cathodic processes of zinc corrosion on the samples are conspicuously suppressed resulting in a large decrease in corrosion current density. A synergistic protection effect for the single silane film and the single molybdate conversion film is evident. The corrosion protection efficiency value was as much as 99.1%. Furthermore, the low frequency inductive loop usually observed in electrochemical impedance spectroscopy (EIS) disappeared and the low frequency impedance values for the composite films initially increased and then decreased with increasing immersion time. This indicates self-healing activity for the composite films. The corrosion resistance of these composite films is superior to some chromate passivation films.

Wangzaozin A (1) is an ent-kaurane diterpenoid isolated from Isodon racemosa (Hemsl) Hara. This natural product exhibits significant cytotoxicity against human Bel-7402 and HO-8910 tumor cells. The structural parameters of compound 1 from X-ray diffraction were compared with those from theoretical calculations at B3LYP/6-31G(d) level compound and the theoretical results were found to be in accordance with the experimental data. The 1H and 13C NMR chemical shifts of compound 1 were also calculated using the gauge independent atomic orbital (GIAO) method at the B3LYP level with the 6-31G(d), 6-31G(d,p), 6-31+G(d,p), and 6-31++G(d,p) basis sets. Results showed that the calculated NMR data for the geometrical conformation optimized using the B3LYP/6-31G(d) basis set are the most accurate by comparison to experimental data. The geometrical conformation optimized using the B3LYP/6-31G(d) basis set, therefore, approximates the real geometric structure of compound 1 most accurately. Statistical error analysis for the theoretically predicted δH and δC values versus experimentally observed values for compound 1 was conducted. A molecular electrostatic potential (MEP) map was used in an attempt to identify key features of the diterpenoid Wangzaozin A to account for its anti-tumor activity. MEP investigations reveal that compound 1, which shows anti-tumor activity, possesses electron-rich regions that extend over the hydroxyl and carbonyl groups of compound 1.

Peat smoldering is one of the main combustion modes of forest ground fires. Research into the pyrolysis kinetics of peat is an essential step in studying the peat smoldering mechanism and ground fire behavior. We measured the elemental composition of one typical peat sampled from the northeast forest zone of China by means of spectrofluorometry and studied the pyrolysis characteristics of peat with thermogravimetry-differential thermal analysis (TG-DTA). Results show that the peat sample is composed of more than 45 elements. The pyrolysis process of peat may be divided into three stages, i.e., dehydration, organic matter pyrolysis and mineral decomposition. Because organic matter pyrolysis played an important role in peat smoldering, the pyrolysis kinetics of organic matter was determined. Using thermal kinetic analysis theory and optimization methods, the model that three-component react parallelly was established to describe the scheme of peat pyrolysis. We found that the scheme containing three-parallel-reactions could describe the pyrolysis kinetics very well.

A Zn-Al-Ti material chip was fabricated by combinatorial technology using an ion beam sputtering method. The anti-corrosion properties of the Zn-Al alloy film and Ti doping effects on its corrosion resistance were investigated. High quality alloy films were obtained using low-temperature diffusion at 200 ℃ for 1 h combined with high-temperature crystallization at 370 ℃ for 2 h in Ar+5% (φ, volume fraction) H2 atmosphere. X-ray diffraction (XRD) and scanning electron microscope (SEM) were also used to characterize the structure and surface morphology of typical samples. The anti-corrosion behavior of samples was studied by electrochemical methods. Results indicated that the corrosion rate decreased markedly when a small amount of Ti was doped in the Zn-Al binary compositions. The Zn-Al-Ti alloy film doped with 6.0% (w, mass fraction) Ti (94.0% (w) Zn-Al with wAl:wZn=55%:45%) showed the best anti-corrosion behavior mainly because the small amount of Ti dopant developed fine grains, made the surface denser, and enhanced its passivation behavior.

Highly ordered CdS nanorods and network nanowires were prapared by reacting cadmium ions with thioacetamide (TAA) using bovine serumalbumin (BSA) as a biomineralization template with a facile and environmentally benign biomineralization method. The morphology, elemental composition, optical property, and microelectronic transmission behavior of the samples synthesized at different reaction temperatures were characterized by means of transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), photoluminescence (PL) emission spectroscopy, and conductivity-atomic force microscopy (C-AFM). Results showed that when the experimental temperature was 20 ℃, monodispersed CdS nanorods with sizes of about 30 nm in diameter and 250 nm in length were obtained; and at 50 ℃, a network of CdS nanowires of about 2-3 μm in length were fabricated. CdS nanorods and nanowires showed a cubic zinc blended structure. Characterization of their fluorescence property showed that CdS nanorods and nanowires had excellent fluorescence. Moreover, characterization of their current-voltage (I-V) characteristics showed that CdS nanowires had od conductivity.

Interactions between the cationic polyelectrolyte polydimethyldiallylammonium chloride (PDMDAAC) and sodium decylsulfate as well as sodium decanesulfonate were investigated by surface tension and pyrene fluorescence spectroscopy techniques. We found that although many properties of sodium decylsulfate and sodium decanesulfonate are similar, there are striking differences in their interactions with PDMDAAC. Sodium decylsulfate interacts with PDMDAAC more strongly than sodium decanesulfonate does. The experimental results in this work were explained by the data of the quantumchemical calculation.

To understand the effects of organic ligands on the reaction equilibrium, interactions between a series of diperoxovanadate complexes [OV(O2)2L]- (L=D2O or HOD, the corresponding peroxovanadate species (bpV)) and [OV(O2)2LL']n-｛n=1-2; LL'=3-hydroxyl-picolinate (3-OH-pic), 2-(2'-pyridine)-imidazole (py-im), 1,10-phenanthroline (phen), the corresponding peroxovanadate species bpV(3-OH-pic), bpV(py-im), and bpV(phen)｝and 1-ethyl-1H-imidazole (N-Et-im) in solution were explored using multinuclear (1H, 13C, and 51V) magnetic resonance, COSY (correlated spectroscopy), HSQC (heteronuclear single quantum coherence) and variable temperature nuclear magnetic responance (NMR) using 0.15 mol·L-1 NaCl ionic medium to mimic physiological conditions. Experimental results indicated that the reactivity of these four complexes with 1-ethyl-1H-imidazole decreased as follows: bpV>bpV(3-OH-pic)>bpV(py-im)>bpV(phen). The coordinating ability, the steric effect, and the molecular weight of these organic ligands affected the reaction equilibrium. A new six-coordinated peroxovanadate species [OV(O2)2(N-Et-im)]- was formed because of competitive coordination.

A molecular conformation study of N'-arylideneacetohydrazide compounds was performed using dynamic NMR (DNMR) spectroscopy and density functional theory (DFT). Three groups of double peak patterns in the 1H NMR spectra were observed, which was the result of rotational hindrance of the N—N bond. The difference in the chemical shift of these peaks decreased with increasing temperature. The exchange rate constants were obtained through simulation of the relationship between the difference in chemical shift and temperature. The energy barriers for rotation of the N—N bond were calculated according to Eyring's equation. A model of coexisting E and Z forms of the N—N bond has been suggested to explain the separation of the NH protons in the NMR spectrum. DFT were carried out to optimize the conformational isomers with minimum energies. Peak separations in the methyl and azomethine signals were also found to originate from the rotation hindrance of the N—N bond. After N'-acylideneacetohydrazides were converted to 1,3,4-oxadiazole compounds, the proton signal of the methyl group appeared as a single peak.

The X-substituted cobalt tetraporphyrins (CoTXPP) (X=H, Cl, NO2) were easily bound to the side chains of the grafting particles poly(4-vinyl-pyridine-co-styrene)/SiO2 (P(4VP-co-St)/SiO2) via an axial coordination reaction to prepare supported catalysts CoTXPP-P(4VP-co-St)/SiO2. Structures of the CoTXPP-P(4VP-co-St)/SiO2 catalysts were characterized with FTIR. The axial coordination reaction between the copolymer P(4VP-co-St) and CoTXPP was studied using electronic absorption spectroscopy. Catalytic performances of the supported catalysts for the oxidation of phenylethane in the absence of any reductant or solvent were investigated and compared in detail. Experimental results show that CoTXPP-P(4VP-co-St)/SiO2 can effectively activate dioxygen and obviously catalyze the oxidation of phenylethane to phenylethanone. The catalytic activities of CoTXPP-P(4VP-co-St)/SiO2 increased as the degree of electron deficiency of the peripheral substituent on the porphyrin ring increased. The catalytic activity of CoTNPP-P(4VP-co-St)/SiO2 was found to be the best. At 120 ℃and under the ordinary pressure of oxygen, the catalyst CoTNPP-P(4VP-co-St)/SiO2 gave excellent results with a 25.53%(x) yield of phenylethanone and very little α-phenylethanol. Additionally, we found that: (1) CoTNPP-P(4VP-co-St)/SiO2 as a biomimetic catalyst had an optimumusage amount, and excess addition would decrease the catalyst's efficiency; (2) the immobilization density of CoTXPP on the surface of P(4VP-co-St)/SiO2 still had a maximum value; (3) the catalyst's activity was stable during six catalytic cycles. All these results indicate that the grafted particles P(4VP-co-St)/SiO2 protect the metalloporphyrins from oxidation and also promote the activation of O2 by the metalloporphyrins.

We obtained resonance Raman spectra and UV absorption spectra of 5-chlorouracil and uracil in methanol and in water. B3LYP/6-311+G(d,p), B3LYP-TD/6-311+G(d,p), and CIS/6-311+G(d,p) computations were carried out to predict their ground state geometries, ground state vibrational frequencies, electronic transition energies, and 1S2 excited state geometries for 5-chlorouracil and uracil. The resonance Raman spectra of 5-chlorouracil and uracil were assigned based on our FT-Raman and FT-IR measurements and density functional theory calculations. Their absorption cross-sections and absolute resonance Raman cross-sections were quantitatively simulated using the time-dependent wave packet formalism. Excited state structural dynamics associated with the lowest singlet 1(π, π*) state was obtained. Results indicate that the major feature of the initial excited state structural dynamics of 5-chlorouracil is along the C5=C6 stretch + C6H12 bending and N3H9/N1H7 bending + N1C6 stretch reaction coordinates, while that of uracil is mostly along the ring stretch + C5H11/C6H12/N1H7 bending and C4=O10 stretch reaction coordinates. We conclude that substitution of 5-Hby a Cl atom results in a p-πconjugation interaction between the pz orbital of the Cl atom and the π or π* orbital of the pyrimidine ring. This makes the vibrational reorganizational energies more partitioned into the ring bending vibrational modes and the C5=C6 vibrational mode for 5-chlorouracil. The major feature of the initial excited state structural dynamics of uracil in methanol is similar to that in water and the wave-packet motions along the C5H11/C6H12/N1H7 bending + N1C6 stretch (υ12) and the ring breathing (υ17) reaction coordinates of uracil are obviously enhanced in methanol relative to those in water.

Dendrimers composed of G1 (generation 1.0) polyamidoamine (PAMAM) and branched with poly(propylene oxide) (PPO)-poly(ethylene oxide) (PEO) were synthesized. The dendrimer series was characterized using Fourier transform infrared (FTIR) spectrometry, mass spectrometry (MS), 1H nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC). Results fromsurface tension and steady fluorescence measurements showed that the critical aggregation concentration (CAC) increased with longer PPO-PEO chains, while the microenvironment of solubilized pyrene became weakly polar. The size distribution of aggregates was examined using the dynamic light scattering (DLS) method, which indicated a narrow distribution and an average hydrodynamic radius (Rh) of around 100 nm. The effect of pH on this system was also investigated and showed that the length of amphiphilic branches played a large role in the protonation process.

Using an acid-base two-step catalysis for the hydrolysis of tetraethyl orthosilicate (TEOS), hydrophobic silica aerogel with a high specific surface area was prepared by an in-situ sol-gel process and ambient pressure drying utilizing the introduction of drying control chemical additives (DCCA) N,N-dimethylformamide (DMF) and trimethylchlorosilane (TMCS) to allowfor the hydrophobic modification of the sol system. The structure and morphology
of these samples were characterized by N2 physical adsorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy (SEM). Results showed that the specific surface area of the hydrophobic silica aerogel modified by this in-situ method was larger than that of an aerogel modified by the ex-situ method. The specific surface area of the former aerogel was up to 979 m2·g-1. The aerogel had a od hydrophobic property because of the hydrophobic group (—CH3) that was linked to the aerogel's surface. After heat treatment at 500 ℃, the aerogel became hydrophilic because it lost most of its hydrophobic groups (—CH3). After heat treatment at high temperature 800 ℃ the hydrophobic silica was still in an amorphous state, which indicated od thermal stability for the hydrophobic silica aerogel.

The binding distance of benzidine to hemoglobin (Hb) and the hydrodynamic radius of Hb in urea-water mixtures were determined by fluorescence quenching and dynamic light scattering, respectively. These data, combined with fluorescence spectra and absorption spectra, were utilized to investigate the interaction between urea and protein as well as its influence on the conformation of protein in aqueous solutions. The results indicated that urea accumulated on the surface of the protein due to its ability to displace water molecules in the solvation shell and to form hydrogen-bond with peptides and hydrophilic side chains, which exhibited a complex influence on protein conformation. It was evident that urea-water mixtures at high urea concentration destabilized the protein conformation whereas those at low urea concentration promoted a more compact one. In the mixtures at high urea concentration, the heme cavity of Hb was found to be of unfolded structure, however similar to the molten globubar state.

Adsorption isotherms of hydrogen on the microporous zeolites A and X under supercritical conditions were modeled using lattice density function theory (LDFT) based on the three-dimensional Ono-Kondo equation. According to the sizes and shapes of the zeolite pores, the local arrangement of adsorption sites within the pores in the LDFT models were simulated by the clusters of simple cubic lattice, face-centered cubic lattice, and body-centered cubic lattice structures. Results indicate that the LDFT models appear to be effective in describing the multilayer or monolayer adsorption of hydrogen on zeolites A and X under supercritical conditions and the calculated adsorption isotherms agree well with the experimental isotherms measured previously. In particular, the hydrogen-zeolite interaction energy parameters used in LDFT models were verified by the Lennard-Jones (12-6) potential model for cylindrical pores based on a thermodynamics method. These results confirm the reliability of LDFT models in describing hydrogen adsorption on zeolite adsorbents. Using the obtained parameters, adsorption isotherms for hydrogen on zeolite X were predicted using the LDFT model over a wider range of temperatures and pressures.

Carbon-nitrogen co-doped titanium dioxide (TiO2) nanoparticles were synthesized by calcining titanium carbonitride (TiCN) powder in air at different temperatures. The as-prepared powders were characterized by X-ray diffraction (XRD), transmission electron microscopy(TEM), ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS), and X-ray photoelectron spectroscopy (XPS). XRDand XPS results showed that nitrogen and carbon in the TiCN lattice could be replaced by oxygen through calcining the TiCN powder in air. Stronger light absorption in both the UV and visible light region was observed for the as-prepared powders compared to commercial P25 from the DRS results. The photocatalytic hydrogen evolution performance over both the as-prepared catalysts and P25 was tested using Na2S-Na2SO3 as a sacrificial electron donor under UV and UV-Vis light irradiation. The highest photocatalytic activity was observed for CN-TiO2 obtained fromTiCNand calcined at 550 ℃. The hydrogen evolution rate reached 41.1 μmol·h-1, which is higher than that from P25 (26.2 μmol·h-1). This may be caused by a synergistic effect between doped C and N elements. Under UV-Vis light illumination, the highest hydrogen evolution rate was 0.2 μmol·h-1, which may be due to a minor contribution of visible light absorption to water photo-splitting for hydrogen production.

Ultra-large scale molecular dynamics simulations were used to investigate the breaking behavior of a [111]||[110] bicrystal copper nanowire. From the periodicity of the copper crystal structure, we developed a discrete Fourier transformation technique to analyze the periodic structure of the crystal system. In particular, the atomic density distribution along the long axis of the nanowire was transformed into a amplitude-frequency relation or into a
normalized atomic density distribution. These two treatments enable us to further study the crystal grain orientation and the crystal structure at different stretching moments of the nanowire. The amplitude-frequency analysis provided information about the large-scale crystallographic features while local characteristics were determined by the normalized atomic density distribution. From analyses of the simulation data, we found that the [111]||[110] bicrystal copper nanowire showed an amalgamation of the grain boundary and a rotation of the crystal grains during stretching and this led to a rupture in the [111] crystal grain. After breaking, the nanowire underwent a newrecrystallization process as determined by amplitude-frequency analysis and normalized atomic density distribution. The Fourier transformation technique proposed in this work provides a powerful tool for theoretical investigations of nanomaterials.

Novel Cu2O/Cu nanocomposites with a flower-like nanoarchitecture were prepared by a facile template-free two-step hydrothermal synthesis route using Cu(NO3)2·3H2O as a precursor. Their properties were characterized by X-ray diffraction (XRD), UV-Vis diffuse reflection spectroscopy (DRS), and scanning electron microscopy (SEM). The flower-like Cu2O/Cu nanocomposites consist of many nanopetals with lengths of 300-500 nm and widths of 30-70 nm. They show strong absorption for visible light. The content of Cu in the composites could be easily controlled by adjusting the hydrothermal time. As photocatalysts, the composites exhibit much higher photocatalytic activity than Cu2O for the photodegradation of Procion Red MX-5B (PR) under visible light illumination when the mass fraction of Cu lies between 27% and 71%. Moreover, flower-like Cu2O/Cu nanocomposites show better performance for the photodegradation of PR than cubic composites. The synthesized composites can also be recycled for further use.

Unusual boron-carbon compounds containing planar tetracoordinate carbon (ptC) and planar pentacoordinate carbon (ppC) were investigated using density functional theory (DFT) at B3LYP/6-311+G**level. These novel compounds are generally assembled with three types of stable structural units C3B2H4 with ptC, CB4H2 with ptC, and CB5H2 with ppC as well as linking elements —CHCH—. On the basis of calculation results the bonding features, spectroscopic properties, and the aromaticities of these novel boron-carbon compounds were discussed. Results show that as for the lowest-energy compounds contained ptC and ppC without being limited by symmetrical planes, stereo cis-structures of C2v symmetry are more stable than the corresponding planar trans-structures. Calculated nucleus- independent chemical shift (NICS) values show that the aromaticity of the center of the three-membered rings is the strongest. The total Wiberg bond indices (WBIs) of the ptC and ppC atoms of the most stable structures of the boron-carbon compounds indicate that the ptC and ppC obey the octal rule.

Nanosized Au/TiO2 catalysts were prepared by the deposition-precipitation method. These catalysts were evaluated by a liquid phase hydrogenation of crotonaldehyde to crotyl alcohol and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). By changing the activation atmosphere, the Au loading, and the reduction temperature we found that the dimension of the Au particles and the metal-support interaction were readily adjustable. For the Au/TiO2 catalyst reduced at 673 K with an optimal Au mass fraction of 9.2%, the mean particle size of Au was 2 nm and the initial hydrogenation rate was as high as 13.7×10-5 mol·s-1·g-1, while the maximum yield of crotyl alcohol was 69.9%. Combined with the characterization results, the superior performance of this catalyst was attributed to it having an optimal size and to its electronic modification effects on the Au nanoparticles. This was due to oxygen defects generated on the TiO2 during the reduction process.

Both chloramphenicol (CHL) and sarafloxacin (SLFX) can quench the fluorescence from bovine serum albumin (BSA). The fluorescence will quench to a larger degree when the two drugs coexist. We thus studied the anta nism between SLFX and CHL using fluorescence spectroscopy. We prove that the anta nism between these drugs increases the binding stability between drug and protein. At the same time, a reduction of the free drug's concentration will reduce the effect of the drugs. Results show that the quenching mechanism of the combination for bovine serum albumin and drugs is a static procedure. The number of binding sites is 1. Based on the theory of Forster energy transfer spectroscopy, the binding distance r between drugs and bovine serum albumin was obtained. Because of the existence of anta nism between the drugs, the correlation coefficient and binding distance are reduced. Synchronous spectra were obtained, which showed the effect of this anta nismbetween the drugs on the conformation of BSA. The protein molecules are extended and their hydrophobic nature is reduced.

Density functional theory (DFT) B3LYP/6-31G* method was employed to optimize the structures of a series of Y-shaped organic heterocyclic molecules containing a thiazole chromophore. Based on the obtained stable molecular configuration, we adopted the finite field (FF) method and time-dependent density-functional theory (TD-DFT) to calculate and analyze the nonlinear optical (NLO) properties and electric spectra of these molecules. Results show that the molecules possess A-π-D-π-A (A: acceptor, D: donor) structures, and the dipole moment of the ground state, the polarizability, and the second-order NLO coefficient (β) of the molecules increase with increase of the length of conjugate bridge of the branched chain and the conjugation effect of the chromophore. The total virtual value of second-order polarizability (βtot) of the series of organic heterocyclic molecules was found to be related to the energy gap of the frontier molecular orbital. The molecule with smaller energy gap of the frontier molecular orbital shows larger values of βtot.

The construction of TiO2with a special architecture to enhance the photocatalytic property of nano-titanium dioxide (TiO2) was achieved by synthesizing a three-dimensional (3D) network TiO2 nanowire film (W-film) on the surface of Ti foil using a hydrothermal method. Samples were characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Results showed that the three-dimensional network nanowire film was composed of many randomly-oriented anatase nanowires, which had diameters of 10-30 nmand lengths larger than 5 μm. Optical properties of these W-films were studied by UV-Vis spectrophotometry (UV-Vis). The results indicated that the absorbency of the W-film was higher than that of a particulate film (P-film) in the 350-700 nm region and the absorption edge was red-shifted. Meanwhile, the absorbency of the W-film increased as the hydrothermal time increased. After further investigation of the photoelectrochemical properties of the W-film in Na2SO4 solution, we determined that the photoelectrochemical properties of the W-film were better than those of P-film. Methyl orange was used as a target molecule to estimate the photocatalytic activity of the W-film. Under the same testing conditions, the catalytic efficiency of the W-film was found to be 2.3 times as that of the P-film and it, therefore, has a bright future. This kind of composited W-film electrode possesses advantages both in flexibility and implementation of the applied potential, which will increase the application field of this TiO2 film.

A possible decomposition mechanismfor ethane on Ni(111) surface was investigated using first-principles density functional theory (DFT) and a self-consistent periodic calculation. The transition states were determined using complete linear synchronous transit and quadratic synchronous transit (LST/QST) methods. All the species involved in this process had four possible adsorption sites (top, fcc, hcp, and bridge) on the Ni(111) surface and all these were fully optimized to obtain their equilibrium geometries and electronic structures. The corresponding adsorption energies and Mulliken charge analyses of these species were predicted and compared. Favorable adsorption sites on the Ni(111) surface for these species were found. In the C—C bond activation pathway, the energy barrier of the rate-limiting step was 257.9 kJ·mol-1. However, the energy barrier of the rate-limiting step was only 159.8 kJ·mol-1 for the C—H bond activation pathway, which suggested that the C—H bond activation pathway would be preferred. As a result, the main products are C2H4 and H2.

Mesoporous tungsten oxides were prepared by a hard templating method using mesoporous silica dioxide (KIT-6) as the hard template, silicotungstic acid (H4O40SiW12·nH2O) as the source of tungsten and by removing silica dioxide with HF. The mesoporous tungsten oxides were characterized by X-ray diffraction (XRD), energy dispersive X-ray(EDX), high resolution transmission electron microscopy (HRTEM), and nitrogen adsorption-desorption isotherms. The influences of the mixing ratio of the silicotungstic acid and mesoporous silica, the calcination temperature of the mixture, and different dispersants on the preparation of the mesoporous tungsten oxides was investigated. Results showed that mesoporous tungsten oxides could be obtained at calcination temperatures of 600-750 ℃ and that mixing mass ratios of silicotungstic acid and mesoporous silica (m(WO3)/m(SiO2)) should be 3:1-4:1. Larger surface area and pore volume were obtained for the mesoporous tungsten oxide when using ethanol instead of distilled water as dispersant.

The geometries of a series of binaphthyl bridged chiral bis-porphyrins were optimized using B3LYP method at 6-31G(d,p) basis set level. The electronic spectra of these porphyrins were then calculated using the semi-empirical ZINDO/S method. Results showed that strong exciton coupling interactions between the two porphyrin chromophores existed in these bis-porphyrins. Davydov splitting of the B bands were related to both the distances and the relative orientations of the two porphyrin rings. First hyperpolarizabilities of these porphyrins were calculated using the ZINDO/SOS method. The second-order nonlinear optical properties of the binaphthyl bridged chiral bis-porphyrins were greatly improved by introducing push/pull substituents onto the porphyrin chromophore. The first hyperpolarizabilities of binaphthyl bridged chiral bis-porphyrins depend on the spatial arrangement of the substituents. The increase in first hyperpolarizabilities of bis-porphyrins is not only related to increasing the dipole moment different between excited and ground state, but also to the relative orientations between the ground state dipole moment vectors and the exciton coupling transition moment vectors.

The permittivities of N,N-dimethylformamide (DMF), water (H2O), and DMF-H2O mixture solution were measured by a resonant cavity perturbation method at 2.45 GHz and 288, 298, and 313 K. The measured results showed a specific phenomenon wherein the imaginary part of the solution's permittivity was larger than that of each of the components. A theoretical calculation indicates that the reason for this phenomenon is high frequency friction increasing in the DMF and H2O mixture. This implies that a new formula needs to be formulated to include hydrogen bond contributions for the explanation of this specific phenomenon.

Poly(N,N-diethylacrylamide) (PDEAM) with a narrow molecular weight distribution was synthesized via atom transfer radical polymerization (ATRP) in methanol using CuBr/2,2'-bipyridyl as the catalyst system and ethyl-2-bromopropionate (EPN-Br) as the initiator. PDEAM was characterized by FT-IR, 1H-NMR, and gel permeation chromatography (GPC). The effects of PDEAM concentration, salts, and surfactant on the lower critical solution temperature (LCST) of PDEAMaqueous solutions were studied by transmittance measurements. It was found that the LCSTdecreased as the concentration of PDEAMincreased and that salts (NaCl, CH3COONa, KCl, Na2SO4, andMgSO4) resulted in a decrease of the LCST of the solution. Species and anions of the salts dominated the salt effect. On the contrary, sodiumdodecyl sulfate (SDS) resulted in an increase in the LCST of the PDEAMaqueous solutions.

Composite cathode material xLiFePO4·yLi3V2(PO4)3 was obtained from wet chemical reduction and lithiation method by using FePO4·xH2O, V2O5, NH4H2PO4, Li2CO3 as raw materials and oxalic acid as reductant. X-ray diffraction (XRD) results showed that the composite material contained olivine LiFePO4 and monoclinic Li3V2(PO4)3 phases. High resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectrometry (EDAX) results indicated that some LiFePO4 and Li3V2(PO4)3 in the composite material were doped by V and Fe, respectively, and formed a solid solution. The valences of Fe and V doping in Li3V2(PO4)3 and LiFePO4 are +2 and +3, respectively. Charge and discharge tests showed that the synthesized composite material exhibited better electrochemical performance than individual LiFePO4 and Li3V2(PO4)3. Cyclic voltammetry indicated the composite material showing od lithium ions extraction/insertion property.

MFI/MFI core-shell zeolites with a low silica to alumina ratio core and a continuous shell of high silica to alumina ratio were successfully synthesized by a novel two-step procedure. This was done by a secondary growth of the ZSM-5 shell onto the modified ZSM-5 crystals and the pre-treatment step played an important role during the synthesis. Critical factors for the growth of the ZSM-5 shell including synthesis temperatures, periods, and core dosages were summarized. Results from cumene and 1,3,5-triisopropylbenzene (1,3,5-TIPB) cracking reactions showed that the core-shell zeolite and the core crystal had comparable activities for the cumene cracking reaction. Compared to the core crystal, the cracking activity of 1,3,5-TIPB of the core-shell zeolite was reduced by 68%, which coincided with the extent of aluminum reduction on the external surface. These results suggested that the acidity of the core crystals was largely preserved in the MFI/MFI core-shell structure. Crystallization kinetics curves were determined at different synthesis temperatures. The apparent energy of crystallization activation was found to be 26.5 kJ·mol-1 and the activation
energy of nucleation was 51.5 kJ·mol-1.

CrOx-Y2O3 catalystswere prepared by a deposition-precipitationmethod and tested by fluorinating 2-chloro-1,1,1-trifleuoroethane (HCFC-133a) to synthesize 1,1,1,2-tetrafluoroethane (HFC-134a). Using Raman spectrum and X-ray powder diffraction (XRD) technique, we found that the atmosphere and the temperature during the calcination process greatly influenced the CrOx species in the catalysts. When the catalyst was calcined in nitrogen and then in air at different temperatures (T) (NAT), the Cr species changed fromCrO3 to YCrO4 and YCrO3 with increasing calcination temperature. The NA500 catalyst showed better stability than the catalyst calcined in air at 350 ℃ (the A350 catalyst), because the YCrO4 species formed during calcination could transform into an active species during the pre-fluorination process and the coke deposition was inhibited on the catalyst surface during the reaction.

The mechanism of ethanol electrooxidation on a Pd electrode was studied by cyclic voltammetry and in situ Fourier transform infrared (FTIR) spectroelectrochemistry. We found that the catalytic activity of the Pd electrode for ethanol oxidation was affected by the pH value of the solution and the concentration of ethanol. Catalytic reactions could not proceed until the solution pH>11.0. The performance for ethanol oxidation on Pd was improved with the increase in the pH value and ethanol concentration. The in situ FTIR spectroelectrochemical measurements indicated that the reaction mechanismand products depend on the pH value of the reaction solution. The main oxidation product was acetate at pH>13.0. The C—C bond cleavage of ethanol occurred as evidenced by the formation of CO2 at pH≤13.0, however, the catalytic activity for ethanol oxidation was quite low. No CO formation was detected during the oxidation of ethanol by FTIR spectroscopy, indicating the electrooxidation was a non-poisoning process.

The dynamic dilational viscoelasticity properties of N-2-(phenoxy)-tetradecanolytaurinate (12+B-T) and N-2-(4-ethylphenoxy)-tetradecanolytaurinate (12+2B-T) at the air/water interface were investigated by drop shape analysis and their foam properties were measured. The influence of time, dilational frequency, and bulk molar concentration on the surface dilational modulus and phase angle were investigated. A molecular interaction controls the nature of the film's adsorption at the lower concentration range and the filmis elastic in nature. At a higher concentration range, a diffusion exchange process controls the dynamic dilational properties and the surface film shows remarkable viscoelasticity. The addition of one ethyl group to the benzene ring enhances the molecular interaction which results in increases of the dilational modulus and foamstability.