Organic-inorganic hybrid solar cells, which combine the advantages of conjugated polymers and inorganic nanocrystals, have attracted a lot of attention and been extensively studied in recent years. Cd-based compound nanocrystals, which were the first inorganic acceptor materials used in hybrid solar cells, have many advantages, such as easy synthesis, controllability of the size and morphology, high charge-carrier mobility, and high stability. This article reviews the structure and working mechanism of organic-inorganic hybrid solar cells, and analyzes the three main factors that have important influences on the power conversion efficiency (PCE) of hybrid solar cells: the open circuit voltage (V_oc), short circuit current density (J_sc), and fill factor (FF). We also summarize the recent progress of Cd-based compound nanocrystal-organic polymer hybrid solar cells from the viewpoints of improvement of the synthetic methods of Cd-based compound nanocrystals, modification of the interfacial contact of Cd-based compound nanocrystals and organic polymer, optimization of the solvent, and the proportions of nanocrystals and organic polymer. Finally, we suggest some strategies to increase solar cell performance and suggest the future research direction of Cd-based compound nanocrystal organic-inorganic hybrid solar cells.

Nitrogen oxides (NO_x), which are emitted from stationary sources (such as coal-fired power plant flue gases) and mobile sources (such as motor vehicle exhausts), cause serious atmospheric pollution. As a result, it is very important to control the emissions of NO_x. Some studies have suggested that NH₃-selective catalytic reduction (NH₃-SCR) of NO_x is one of the best techniques for this purpose. Ceria-based catalysts are widely used in the NH₃-SCR reaction because of their od redox ability, suitable surface acidity, high oxygen storage or release capacity, and rich resource reserves. Investigating the role of ceria component in this reaction is important to understand the nature of the related catalytic process, and provides a valuable scientific reference for the optimization of existing catalysts and the design of novel catalysts. Based on the different roles of ceria in NH₃-SCR catalysts, we have performed a systematic review of the latest research progress of ceria-based catalysts in the NH₃-SCR reaction for the following aspects: CeO₂ used as supports, ceria-based mixed oxides, surface loading components (additives and active species), and ceria-based catalysts with special structures. Finally, we discuss the future directions of this field.

N₂O⁺ ions in the X²П(0,0,0) ground state were prepared by (3+1) resonance-enhanced multiphoton ionization (REMPI) of jet-cooled N₂O molecules at 360.55 nm, and then photoexcited to various vibrational levels in the B²П state over a wavelength range of 243-278 nm, followed by dissociation. The photofragment excitation (PHOFEX) spectrum was recorded by measuring the intensity of NO⁺ ion fragments vs excitation wavelength. The rotational constants and spin-orbit coupling were obtained by fitting the rotational structures of the vibrational bands. Thus, the contributions of highly excited vibronic levels of A²Σ⁺ states were distinguished from the other bands, and the original band of B²П state was verified. The series of vibrational bands in the PHOFEX spectrum were assigned to the transition of B²П(v₁,v₂,v₃) ←X²П. The average released kinetic energy of dissociation from the various B²П(v₁,v₂,v₃) ionic states was obtained by fitting the spreading contour of the NO⁺ ion peak in time-of-flight mass spectra. Dissociation mechanisms of N₂O⁺(B²П) were proposed with the aid of the theoretical potential energy surfaces of N₂O⁺ ions.

Ignition delay measurements of gas-phase decalin/air mixtures were performed in a shock tube at temperatures of 950-1395 K, pressures of 1.82×10⁵ to 6.56×10⁵ Pa, and equivalence ratios of 0.5, 1.0, and 2.0. The ignition delay time was determined using the reflected shock wave pressure and CH^* emission monitored at the sidewall. The effects of temperature, pressure, and equivalence ratio on the ignition delay time of decalin were investigated systematically. The results show that increasing the temperature or pressure decreases the ignition delay time. Opposite ignition delay dependences on the equivalence ratio were observed for decalin/air at high and low pressures, for the first time. At 15.15×10⁵ Pa, the fuel-rich mixture showed the shortest ignition delay time, and the fuel-lean mixture gave the longest one. However, at 2.02×10⁵ Pa, the fuelrich mixture had the longest ignition delay time. Comparisons of the experimental data with predictions based on the available kinetic mechanism were made; the trends in the experimental data were in od agreement with the predictions under all conditions studied. A sensitivity analysis was performed to obtain insights into the effects of the equivalence ratio on the ignition delay time at low and high pressures. The results show that ignition is mainly controlled by the reaction H+O₂=OH+O at 2.02×10⁵ Pa. However, the reactions involving decalin and its corresponding radicals play important roles at 15.15×10⁵ Pa.

The extraction of UO₂(NO₃)₂ from aqueous solution was investigated using trioctylphosphine oxide (TOPO) and tributylphosphine oxide (TBPO) in ionic liquids (ILs) (C_nmimNTf₂, n=2, 4, 6, 8). A third phase was formed in the TOPO-C₂mimNTf₂ and TOPO-C₄mimNTf₂ extraction systems, whereas the extracted species of TBPO-C_nmimNTf₂ (n=2, 4, 6, 8) were well soluble in all ILs. The influence of the concentrations of the extractant, nitric acid, and salt on the extraction efficiency was also investigated. Adding HNO₃ to the aqueous phase decreased the extraction efficiency. The effect of salt indicates the presence of a cation-exchange mechanism in the extraction. The addition of NO₃ - in the aqueous phase increased the extraction efficiency of U, which indicates that NO₃ - participates in the extraction. Selective extraction research indicates that TBPO-C₄mimNTf₂ exhibits od selectivity for U at low acid concentration despite the significant extraction efficiency on Zr at high acid concentration. After removing U, TBPO-C₄mimNTf₂ still showed high selectivity for Nd at low acid concentration. We also confirmed the difference of the extraction mechanisms among TBPO-C_nmimNTf₂ by quantitative measurement of NNO₃ - in ILs, electrospray ionization mass spectroscopy (ESI- MS), and UV spectroscopy. There are two extraction species (UO₂(TBPO)₃(NO₃)⁺ and UO₂(TBPO)₃²⁺) and the proportion of UO₂(TBPO)₃(NO₃)⁺ increases from C₂mimNTf₂ to C₈mimNTf₂.

Mechanisms for the [Fe(MgBr)₂] catalyzed cross-coupling reaction between ortho-chlorostyrene and phenylmagnesium bromide to form biaryl were studied using density functional theory (DFT) calculations. We investigated two mechanisms. Cycle A included three basic steps: (I) oxidation of [Fe(MgBr)₂] to obtain [Ar- Fe(MgBr)], (II) addition to yield [Ar-(phenyl)-Fe(MgBr)₂], and (III) reductive elimination to return to [Fe(MgBr)₂]. Cycle B did not form [Ar-Fe(MgBr)]. In the first step, phenylmagnesium bromide attacks the intermediate of the oxidative addition directly before [Cl-Mg-Br] dissociates to form [Ar-Fe(MgBr)]. The catalytic Cycle B is favored over the catalytic Cycle Awhen considering the solvent effect. The rate-limiting step in the overall catalytic cycle for both Cycle A and Cycle B is the reductive elimination of [Ar-(phenyl)-Fe(MgBr)₂] to regenerate the catalyst [Fe(MgBr)₂], where the Gibbs free energy in solvent tetrahydrofuran (THF), ΔG_sol, is 82.98 kJ ·mol^-1, as determined using the conductor polarized continuum model (CPCM) method.

Intramolecular hydrogen migration in alkylperoxy reactions is one of the most important reaction classes in hydrocarbon combustion at low temperatures. In this study, the kinetic parameters for reactions in this class were calculated using the isodesmic reaction method. The geometries for all the reactants, transition states, and products were optimized at the B3LYP/6-311+G(d,p) level. A criterion based on conservation of the reaction-center geometry of the transition state was proposed for the reaction class, and the intramolecular hydrogen migration reactions studied were divided into four classes, i.e., (1,3), (1,4), (1,5), and (1,n) (n=6, 7, 8) hydrogen migration. The simplest reaction system for each reaction class was defined as the principal reaction; the approximate single-point energies were obtained at the low level of B3LYP/6-311+G(d,p) and accurate single-point energies were obtained at the high level of CBS-QB3. The other reactions in this class were chosen as the target reactions and the approximate single-point energies were obtained at the B3LYP/6- 311+G(d,p) level. The energy barriers and rate constants of these target reactions were corrected using the isodesmic reaction method. The results showed that accurate energy barriers and rate constants for the reactions of large molecules can be obtained by a relatively low level method using the isodesmic reaction method. In this study, classification of the basic isodesmic reaction showed the essential features of the reaction classes. The present work provides accurate kinetic parameters for modeling intramolecular hydrogen migration reactions of hydrocarbons at low temperatures.

We used first-principles calculations to investigate the photo-induced electron transfer (PIET) process of the hemicyanine-(TiO₂)_n complex ((TiO₂)_n-dye) for n=5, 9, 15. The geometries of the (TiO₂)_n-dye in the ground state were optimized using density functional theory (DFT) and their excited states were investigated using the time-dependent DFT (TDDFT) method. The excited energies, which were calculated using the longrange- corrected functionals, CAM-B3LYP and ωB97X-D, were in od agreement with the experimentally observed values. The wave functions based on DFT were used to calculate the charge transfer integrals by the generalized Mulliken-Hush (GMH) approach. In addition, the photo-induced charge separation rate constant (k_CS) and charge recombination rate constant (k_CR) were calculated using Marcus theory. The calculated results showed that there were a cascade of electron transfer channels from the dye into the (TiO₂)_n cluster, which increases the k_CS value. In contrast, the single channel of charge recombination decreases the k_CR value, which is negligible compared with k_CS, indicating that electron recombination is not favored.

Chlorinated phenols (CPs) are the main precursors for forming the persistent organic pollutants dioxins and have strong teratogenicity, carcinogenicity, and mutagenicity. To explore the novel material for the removal or detection of these pollutants, we used density functional theory calculations to investigate the adsorption behaviors and interaction mechanisms of 2-chlorophenol (2-CP), 2,4,6-trichlorophenol (TCP), and pentachlorophenol (PCP) on pristine and Co-doped (8,0) single-walled boron nitride nanotubes (denoted by BNNT and Co-BNNT, respectively). The results show that compared with BNNT, Co-BNNT introduces local states near the Fermi levels, and has a smaller band gap. BNNT physisorbs 2-CP, TCP, and PCP molecules, whereas Co-BNNT presents chemisorption towards them. Charge-transfer between Co-BNNT and molecules can be clearly observed and the electronic densities of states of the doped systems change significantly near the Fermi levels after adsorption of molecules. Doping with Co atom significantly increases the electronic transport capability of BNNT and enhances the adsorption reactivity of the tube to CPs. Co-BNNT is expected to be a potential material for removing or detecting CPs pollutants.

The adsorption behavior of cinnamaldehyde on icosahedral Au₁₃ and Pt₁₃ clusters was investigated by density functional theory with the Perdew-Burke-Ernzerh of generalized gradient approximation (GGA-PBE). When analyzing the adsorption energies and geometrical parameters of different adsorption models, the adsorption energy of cis-cinnamaldehyde was higher than that of trans-cinnamaldehyde for the same cluster. On the Au₁₃ cluster, the most stable adsorption was the C＝O and C＝C double bond coadsorption model. While on the Pt₁₃ cluster, the most stable adsorption was the C＝O double bond adsorption model. Comparison between the Au₁₃ and Pt₁₃ clusters showed that the adsorption capacity of cinnamaldehyde on the Pt₁₃ cluster was higher than on the Au₁₃ cluster. Analyzing the electronic structures of the most stable adsorption configurations of cinnamaldehyde on the Au₁₃ and Pt₁₃ clusters showed that electrons transferred from 2s and 2p orbitals of cinnamaldehyde to the metal clusters. Electrons of metal clusters were also back-donated to the anti-bonding orbitals of the cinnamaldehyde molecule. This collaborative process eventually led to the stable adsorption of cinnamaldehyde on the Au₁₃ and Pt₁₃ clusters. In addition, adsorption of cinnamaldehyde on cluster models was more energetically favorable than on flat models.

Cyclodextrins (CDs) are widely used in the pharmaceutical industry, and the complex stability constant (logK) is an important evaluation target for CD inclusion complexes. In this work, the structures of the inclusion complexes of 233 compounds with β-cyclodextrin (β-CD) were investigated by the quantitative structure-activity relationship (QSAR) method based on a new set of norm indexes proposed by our group. Here, using several arithmetic approaches, a set of QSAR models based on these new norm indexes were developed to predict the logK values of the β-CD complexes. The results showed that all of the norm indexbased- QSAR models could predict logK well, and the best QSAR model was obtained using the least-squares support vector machine method with correlation coefficient (R), leave-one/ten-out validation correlation coefficient (Q_LOO and Q_LTO) values of 0.9587, 0.8775, and 0.8732, respectively. Comparison with other methods suggested that our method performed better for predicting the logK values of β-CD complexes in terms of both accuracy and stability, especially for the discrimination of isomer structures. The results of this and previous studies demonstrate that it might be possible to use the norm index-based model to predict not only the basic physical-chemical properties, but also the chemical reaction-related constants of organic compounds.

The doping energies and electronic structures of B, N, Si, P, and Co in C₅₀ and C₇₀ were investigated using the density functional theory (DFT)-B3LYP/6-31G^* method, and the structural stabilities of doped fullerenes were investigated based on curvature theory and the electronic structures. The calculated results showed that the doping energies decreased with increasing curvature, and increased with increasing atomic radius of the doping species. Doping with B, N, P, and Co stabilized the C₅₀ structure. However, doping with B and N was disadvantageous for the structural stability of C₇₀. The doping reactivities were mainly determined by the curvature and related to the percentage of nonequivalent carbon atoms in the highest occupied molecular orbital (HOMO), and a large percentage was beneficial for the doping stability. In addition, whether the doped atoms accepted or lost electrons depended on their electronegativity. This work will be helpful for the stabilization of fullerene structures in experiment.

A spherical Li[Ni_1/3Co_1/3Mn_1/3]O₂ cathode material for lithium-ion batteries was synthesized using a combination of modified carbonate co-precipitation and solid-state methods. The as-prepared material was analyzed using X- ray diffractometry (XRD), scanning electron microscopy (SEM), galvanostatic chargedischarge tests, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The results indicate that the material synthesized using this new method has a well-ordered layered structure, α-NaFeO₂ [space group: R3m(166)], a spherical morphology, and an average particle size of 157 nm. Electrochemical measurements showed that the material has a od rate capability and long-term cycling performance. At a current density of 0.1C (1.0C=180mA·g^-1) in the voltage range 2.7-4.3 V, the initial discharge capacity was 156.4 mAh·g^-1 and the coulombic efficiency was 81.9%. At 0.5C, 5C, and 20C, the specific capacities of the material were 136.9, 111.3, and 81.3 mAh·g^-1, respectively. After 100 cycles at 1C, the material retained 92.9% of its initial capacity; this is higher than those of materials prepared using conventional carbonate co-precipitation (87.0%).

Anatase TiO₂ shows excellent long-term cycling stability as an anode for sodium-ion batteries. However, the low specific capacity and poor rate capability resulting from its intrinsic low electrical conductivity limit its applications. In this work, TiO₂ nanoparticles were coated with reduced graphene oxide (R ) using a combination of spray-drying and heat treatment. Electrochemical tests showed that the obtained R /TiO₂ composites had improved electrochemical performances. The reversible capacities of the R /TiO₂ [4.0% (w)] composites were 183.7 mAh·g^-1 (20 mA·g^-1), 153.7 mAh·g^-1 (100 mA·g^-1), and 114.4 mAh·g^-1 (600 mA·g^-1). Bare TiO₂ showed low capacities of 93.6mAh·g^-1 (20mA·g^-1), 69.6mAh·g^-1 (100mA·g^-1), and 26.5mAh·g^-1 (600 mA·g^-1). The 4.0%(w) TiO₂/R composites exhibited od cycling stability with a charge capacity of 146.7 mAh·g^-1 at a current density of 100 mA·g^-1 after 350 cycles, compared with 68.8 mAh·g^-1 for bare TiO₂. R modification is a promising method for improving the electrochemical performances of the sodium energystorage materials.

The electrochemical behavior and thermodynamic properties of GdCl₃ in LiCl-KCl molten salt system on both Mo and Al electrodes at 773 K were investigated. An open circuit chronopotentiogram was used to determine the equilibrium potentials and standard apparent potentials of the Gd(III)/Gd(0) system in the temperature range 723-873 K. The results showed that the equilibrium potentials and apparent standard potentials became positive with increasing temperature. The activity coefficients of GdCl₃ were calculated at different temperatures. The depolarization values were calculated by steady state polarization tests, and the theoretical extraction efficiency was obtained at 773 K. Potentiostatic electrolysis was performed to extract gadolinium from LiCl-KCl-GdCl₃ molten salt on Al electrodes at -1.5 V. The extraction efficiency was about 94.22% after 20 h. The Al₃Gd phase was identified in the deposit by X-ray diffraction (XRD).

A new Pt-based electrocatalyst with one-dimensional tubular Mn₃O₄-C as the catalyst support was synthesized by a dual-sacrificial template strategy. The morphology, structure, and composition of the Pt-Mn₃O₄- C composite were characterized by transmission electron microscopy, X-ray diffraction, and energy dispersive X-ray spectroscopy, respectively. The electrochemical performance of Pt-Mn₃O₄-C was investigated by cyclic voltammetry. The results show that Pt nanoparticles with an average size of 1.8 nm are uniformly dispersed on tubular Mn₃O₄-C, and Pt-Mn₃O₄-C exhibits superior electrocatalytic activity and higher stability for methanol oxidation than the commercial E-TEK Pt/C catalyst (20% (w, mass fraction) Pt). The excellent performance of Pt-Mn₃O₄-C is attributed to the uniform dispersion of Pt nanoparticles on Mn₃O₄-C and the synergetic catalytic effect of Pt and Mn₃O₄.

A series of W/SiO₂/Al₂O₃ catalysts with various tungsten loadings were synthesized via the impregnation method. The as-synthesized catalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, H2 temperature-programmed reduction (H₂-TPR), and NH₃ temperature-programmed desorption (NH₃-TPD). The results reveal that the tungsten loadings were crucial to the dispersion and reducibility of the tungsten oxide species and the acidity of catalysts. The catalytic performances were also investigated during the metathesis of 1-butene to propene. Amongst these catalysts, W/SiO₂/Al₂O₃ with a tungsten mass fraction of 6.0% gave the highest activity and stability during the 1-butene metathesis reaction. The excellent catalytic performance of the catalyst containing a tungsten mass fraction of 6.0% is attributed to its moderate dispersion, suitable reducibility of the WO_x species and suitable acidity. We speculate that these factors are favorable for the formation of active centers for olefin metathesis.

Nickel catalysts supported on TiO₂ were prepared using an impregnation method. Changes in the reduction temperature from 200 to 400 ℃ resulted in dispersion of nickel with different oxidation states on TiO₂. The gas-phase hydrogenation of acetonitrile was found to be influenced by the nickel oxidation state. Nickel reduced at 300 ℃ gave the highest acetonitrile conversion ratio, i.e., about 100%, when the reaction temperature was 100 ℃. The product yields depend on the amount of acidic sites on Ni/TiO₂ catalysts; this can be influenced not only by the TiO₂ support, but also by the properties of the supported nickel nanoparticles. The triethylamine yield increased to a maximum (from 34% to about 48%) with increasing reduction temperature; this corresponded to the gradual appearance of Ni⁰ in Ni/TiO₂ and a decrease in the intrinsic acidity of the Ni/TiO₂ catalyst. Triethylamine was the initial product in the hydrogenation of acetonitrile with Ni/TiO₂. The oxidation state of nickel influenced not only the conversion of acetonitrile but also desorption of the final products. Amechanism for the first step in this reaction is proposed.

A series of novel catalysts derived from Ni-Mg-Al-LDHs (LDHs: layered double hydroxides) were synthesized in-situ on γ-Al₂O₃ and evaluated in CO₂ reforming of CH₄ (dry reforming of methane, DRM) reaction system. The catalytic precursors were decomposed and reduced by calcination and an atmospheric plasma technique, respectively. Activity and stability tests showed that the catalytic properties were greatly affected by the pretreatment method. The best catalytic performance was obtained with the catalyst that was directly reduced and decomposed using an atmospheric H₂/Ar plasma jet. Compared with the pure LDH precursor, Ni- Mg-Al-LDHs/γ-Al₂O₃ had much greater mechanical strength, because of the γ-Al₂O₃ support. This feature extends the long lifetime of catalyst at high temperatures. X-ray diffraction (XRD), transmission electron microscopy (TEM), N₂-adsorption-desorption, and thermogravimetry-differential thermal analysis (TG-DTA) results showed that the excellent catalytic performance was based on the small particle size and uniform dispersion of active Ni crystals, as well as the high mechanical strength and large specific surface area of the catalyst.

A novel visible-light-responsive photoanode (Ta/Al-Fe₂O₃) was fabricated by co-doping Ta and Al into iron oxide. The properties of the prepared electrodes were examined using X- ray photoelectron spectroscopy (XPS) and ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy. XPS analysis suggested that the surface chemical environments of Al and O were significantly affected by Ta doping. Photoelectrochemical (PEC), electrocatalytic (EC), and photocatalytic (PC) degradations of methylene blue (MB) were performed using Ta/Al-Fe₂O₃ and Al-Fe₂O₃ electrodes as the photoanodes. The results indicated that synergetic effects in PEC enhanced the MB degradation efficiency compared with the individual PC or EC processes. The estimated rate constant for MB degradation on Ta/Al-Fe₂O₃ was about twice that on Al-Fe₂O₃ under visible-light irradiation in the PEC process. The greatly improved visible-light activity and film stability indicated that Ta doping was an efficient way to improve the PEC activity of Ta/Al-Fe₂O₃ films.

Pore structure and acidity of ZSM-5 catalysts were successfully regulated by alkali treatment. ZSM- 5 was etched in 0.2 mol·L- 1 NaOH solution at 65 and 85 ℃. Micro-mesoporous ZSM-5 catalysts were successfully prepared with a high density of acidic sites. The activity and stability were significantly enhanced with alkali-treated ZSM-5, giving a conversion of glycerol above 95%, with selectivity for acrolein of 78% after 10 h compared with a ZSM-5-at85 (alkali-treated at 85 ℃) catalyst. Characterization of N₂ adsorption and desorption isotherms, X-ray diffraction (XRD), ²⁷Al mass atomic spectroscopy-nuclear magnetic resonance (²⁷Al MAS-NMR), and transmission electron microscopy (TEM) were performed to interpret the morphology and surface properties. The results reveal that the Si in the framework of ZSM-5 was leached out by alkali treatment, and many mesopores were formed on the ZSM-5 surface. However, the MFI topology did not change and Al was mainly integrated within the framework. X-ray photoelectron spectroscopy (XPS), X-ray fluorescence (XRF), and NH₃-temperature-programed desorption (NH₃-TPD) experiments demonstrated that the molar ratio of Si/ Al on the external surface was lower than that in the framework, indicating that more Si on the external surface of ZSM-5 was leached by alkali treatment, while the acidic density increased because of the lower molar ratio of Si/Al near newly formed mesopores. ZSM-5 catalysts with mesopores and higher acidic density enhance reactant diffusion and coking tolerance, which improves the activity and stability during glycerol dehydration.

Butyl levulinate (BL) is one of the most important biochemicals derived from cellulose, and it is of particular interest in industrial applications. Efficient synthesis of BL from cellulose in bio-butanol (bio-BuOH) medium has been investigated in the presence of acidic SO₃H-functionalized ionic liquid (SFIL) catalysts. The results showed that the acid strength of the SFILs, catalyst dosage, reaction temperature, reaction time, and solvent composition significantly affected the conversion of cellulose and the yield of the target products. Using the strongest acidic SFIL 1- (4-sulfobutyl)-3-methylimidazolium hydrosulfate ([C₄H₈SO₃Hmim]HSO₄) as the catalyst, 98.4% of cellulose could be converted into 31.1% of BL accompanied with 33.4%, 20.6%, and 23.8% of butyl formate (BF), water soluble products (WSPs), and biofuel (Biof), respectively, under the optimized conditions. This catalytic system was water-tolerant, and the addition of 0.2 mL water did not significantly decrease its ability for conversion of cellulose. Furthermore, this acidic SFIL catalyst could be recycled up to six consecutive times without loss of catalytic activity.

Laser-induced incandescence (LII) is an optical diagnostic method used to measure the soot volume fraction in a flame. In this paper, the principle of LII and the calibration methods normally used are introduced. Based on two-color LII theory, a quantitative test system for determining the in-cylinder soot volume fraction was established. A dual imaging setup was used, which can achieve multipoint calibration and full field-of-view quantification of soot in a diesel engine chamber. An investigation was carried out on an optical diesel engine with the conditions 1200 r·min^-1 and 21 mg fuel injection per cycle, with various injection pressures (60, 100, and 140 MPa). The results show that the natural soot incandescence emerged after the peak rate of combustion heat release. With increasing injection pressure, the duration of natural soot incandescence shortened and the natural soot luminosity decreased. The range of soot volume fractions in the test zone was (0-50)×10^-6. The mean soot volume fraction at the initial soot stage, soot peak, and soot oxidation stage were in the ranges (5-9)×10^-6, (15-20)×10^-6, and (14-16)×10^-6, respectively, depending on the injection pressure. With increasing injection pressure, the distribution area of the soot particles increased, the mean soot volume fraction decreased, and the distribution of the soot volume fraction in space tended to be more uniform in combustion flames.

The reactive fluorescent dye 4- methoxy-N-(2- hydroxy- 1- hydroxymethylethyl) naphthalimide (MHHNA) was first synthesized by imidization and substitution reactions using 4-bromo-1,8-naphthalic anhydride, 2- amino- 1,3- propanediol, and sodium methoxide as initial materials. A series of covalent fluorescent polyurethane (PU) (PU-MHHNA) emulsions were then fabricated using MHHNA as the chain extender through a phase inverse self-emulsification process. The chemical structure of the synthesized fluorescent dyes and the properties of PU-MHHNA emulsions and their latex films were characterized by 1H nuclear magnetic resonance (¹H NMR) spectroscopy, ¹³C nuclear magnetic resonance (¹³C NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, elemental analysis, ultraviolet- visible (UV- Vis) absorption spectroscopy, fluorescent spectroscopy, particle size analysis, and xenon arc aging measurements. The fluorescent quantum yields of MHHNA and PU-MHHNA were 0.73 and 0.92, respectively. The amount of MHHNA had no obvious influence on the colloidal properties of the PU-MHHNA emulsions. The maximum wavelength (λ_max) of the UVVis absorption spectra was 360.6 nm, and fluorescent spectroscopy analysis indicated that the maximum excitation wavelength (λ_ex) and maximum emission wavelength (λ_em) of PU-MHHNA in acetone were 362 and 435 nm, respectively. In addition, the fluorescence intensity of PU- MHHNA decreased with increasing temperature. The light fastness and solvent fastness of the PU-MHHNA film were much better than those of the non-covalent fluorescent polyurethane (PU/MBNA) film.

The tungsten carbide catalyst is a hot research topic because its catalytic properties are similar to those of platinum. In this paper, a tungsten carbide-montmorillonite (MMT) nanocomposite was fabricated by combining chemical immersion with reduction and carbonization in situ using tungsten hexachloride as the tungsten source and an exfoliated MMT layer as the support. The crystal phase of the sample is composed of monotungsten carbide (WC), bitungsten carbide (W₂C), and MMT, and tungsten carbide is distributed on the outer surface of MMT with a granular or lamellar manner. The components of the crystal phase of the sample are related to the reduction and carbonization time during preparation. The microstructure of the sample is related to the ratio of tungsten to MMT in the precursor used to prepare the sample. The electrocatalytic activity of the sample for methanol oxidation was measured by cyclic voltammetry with a three-electrode system in acidic solution. The results show that the electrocatalytic activity of the sample is improved by compositing tungsten carbide on the surface of MMT, and the electrocatalytic activity is similar to that of platinum. After 5 h reduction and carbonization, a precursor with a 4:1 ratio of tungsten to MMT transformed into a sample with 82%and 18% of WC and W₂C, respectively (ratio of WC to W₂C 4.556). The WC phase forms a uniform loaded layer on the surface of MMT. The electrocatalytic activity of this sample is the highest of the compositions considered. This outline a method to fabricate a tungsten carbide electrocatalyst with similar electrocatalytic activity to platinum.