Alkaline polymer electrolyte membrane fuel cell (APEMFC) has received much recent attention, primarily motivated by their fast dynamics and independence on expensive Pt-based electrocatalysts. As one of vital components of APEMFC, the alkaline polymer membrane directly influences their performance and cost. However, to date, no alkaline membrane has provided a satisfactory benchmark for use in APEMFC. Therefore, intensive efforts have been made to pursue desirable polymer membrane materials. In this article, the research progress over the last 3 years on state-of-the-art alkaline polymer electrolyte membranes for APEMFC is reviewed, including various synthesis strategies, structure-property relationships, water management, and ex situ and in situ stability tests. More specifically, some new metal- cation- based anion exchange membranes, such as ruthenium-complex-based and crown-ether-based anion exchange membranes, are commented on for the first time. Furthermore, future development prospects are also predicted.

This article has been retracted at the request of the authors.

The S₁←S₀ electronic transition and threshold ionization of the cis and trans rotamers of m-methylanisole were investigated by using one- color resonant two- photon ionization and mass- analyzed threshold ionization techniques. The first electronic excitation energies (E₁) of the cis and trans rotamers were determined to be (36049±2) and (36117±2) cm^-1, while the adiabatic ionization energies (I_p) were (64859 ± 5) and (65110 ± 5) cm^-1, respectively. The results of ab initio and density functional theory calculations provide a satisfactory interpretation for our experimental findings concerning the difference in the transitional energies of the cis and trans rotamers and assist in assigning the vibronic and cation spectra obtained in the present study. The observed active vibrations of both rotamers in the S₁ and D₀ states primarily consist of methyl torsion, in- plane ring deformation, and substituent- sensitive bending modes. Both experimental and theoretical results show that, for both cis and trans isomers, the geometry of the cation in the D0 state is somewhat different from that of the neutral species in the S₁ state. In addition, the strengths of both the through- space substituent- substituent and substituent- ring interactions were found to follow the order: S₀<S₁<D₀.

Accurate predictions of the pVT properties of alkanes are very important since they are associated with many fundamental aspects in energy, power engineering, and chemical engineering fields. Predicting the properties of alkanes in the critical region, however, remains challenging. In this work, a crossover volume translation Soave-Redlich-Kwong (SRK) equation of state (EoS) was developed for C1 to C20 alkanes, in which volume translation and crossover methods were combined to improve the description of saturated liquid densities and thermodynamic properties in the critical region. The parameters of the crossover equation are set as constants or expressed as functions of critical parameters and the acentric factor. Comparisons showed that the average deviations of the crossover volume translation SRK equation results for C1 to C20 alkanes were 1.01% for vapor pressure, 1.83% for saturated vapor density, and 0.93% for saturated liquid density, and these deviations are much lower than those obtained with the SRK equation of state. In addition, prediction results for properties in the single phase region and the critical region from the crossover equation were in better agreement with experimental data than those from the SRK equation. The crossover volume translation SRK equation was also extended to the pVT properties of cycloalkanes (cyclopropane, cyclopentane, and cyclohexane), benzene and toluene. The prediction results were also satisfactory, demonstrating the superior predictive ability of the crossover equation of state.

Recent experimental results have indicated that the negative thermal expansion is a common phenomenon in PbTiO₃-based materials, and that this expansion is affected by various substitutions. Interestingly, Cd substitution in PbTiO₃ has a unique effect compared with other A-site substitutions, in that it enhances negative thermal expansion. Therefore, studying A-site substitution in PbTiO₃, the role of which still remains unclear, would provide a deeper understanding of the nature of the negative thermal expansion of PbTiO₃-based materials. Herein we report the results of structural calculations, densities of states and the minimumelectron densities of Pb_1-xSr_xTiO₃, Pb_1-xBa_xTiO₃, and Pb_1-xCd_xTiO₃ supercells on the basis of chemical bond first-principles calculations. The results demonstrate that the hybridization between Cd―O orbitals is more pronounced than that between Pb―O orbitals, while the bonding between Ba/Sr and O is almost ionic in nature. Cd substitution was found to have an unusual effect in terms of enhancing the average bulk coefficient of thermal expansion in PbTiO₃. In contrast, Ba and Sr substitutions reduce the coefficient. Thus, the covalency in the bonding between the A- site and O in PbTiO₃- based materials is responsible for the enhanced negative thermal expansion.

The gas composition in natural gas hydrate deposits is complex, and therefore the use of spectroscopic analysis to elucidate the chemical composition is of great significance. Using density functional theory (DFT) calculations at the B97-D/6-311++G(2d, 2p) level, we systematically explored the stability of 18 alkane guest molecules in two standard water cavities (5¹²6² and 5¹²6⁴). The results indicated that most alkane guest molecules can be stored in the 5¹²6² cage, with the exception of 3-methylpentane and 2,3-dimethylbutane, while all 18 alkanes can be encapsulated in the 5¹²6⁴ cage. The Raman spectroscopic characteristics of five straight-chain and four cyclic alkane guest molecules in the 5¹²6² and 5¹²6⁴ cages were also simulated. The majority of the Raman bands of the straight-chain alkanes in the C―H stretching region were found to move to higher wavenumbers as the number of carbon atoms increased, while most bands of the cyclic molecules in this region transitioned to lower wavenumbers. These theoretical results should prove helpful with regard to identifying hydrate deposits from experimental Raman spectroscopic data.

Multireference approaches have commonly been employed to calculate low-lying states of openshell molecules with spin-orbit coupling (SOC), such as for AuO and AuS. However, by choosing a proper reference state, the equation-of-motion coupled-cluster approach (EOM-CC) can also be used to calculate some low-lying states of these molecules. Furthermore, the EOM-CC approach is a single-reference method and, therefore, more easily employed than multireference approaches. In this work, low-lying states of AuO and AuS are investigated based on a recently developed EOM-CC approach for ionization potentials (EOMIP-CC) with SOC at the CCSD level, using the corresponding anions as reference. The contribution of triples with EOMIPCC is estimated by comparing results of EOMIP-CCSD and EOMIP-CCSDT at a scalar relativistic level. In addition, compared with the EOMIP-CCSDT results, errors by UCCSD(T) can reach 0.1-0.15 eV when spin contamination is significant and the norm of T₁ is sizeable. When SOC is present, bond lengths and harmonic frequencies obtained with EOMIP-CCSD for the investigated states are in reasonable agreement with experimental data. Furthermore, ionization energies corresponding to the high-lying ²Δ_3/2, ²Σ_1/2⁺, and ²Π_1/2 states are overestimated by EOMIP-SOC-CCSD, but results for the other low- lying states agree well with the experimental data, with an error of approximately 0.2 eV. These results indicate that the single-reference EOMIPCCSD method with SOC is able to provide a reasonable description of low-lying states of AuO and AuS.

The adsorption behavior and selective hydrogenation reaction mechanisms (C=O addition, C=C addition, and 1,4-conjugate addition) of cinnamaldehyde on an Au(111) surface were investigated by density functional theory combined with a periodic slab model. The adsorption energies of various adsorption models were obtained to determine the preferred adsorption configuration. The calculated results indicate that the most stable adsorption configuration involved the C=O and C=C double bond adsorbed on the Au(111) surface, with an average adsorption energy of 140.0 kJ·mol^-1. The transition states of each elementary reaction for all possible reaction mechanisms were also located. Comparison of the activation energy barriers revealed hydrocinnamaldehyde (HCAL) to be the most likely selective hydrogenation product of cinnamaldehyde on an Au(111) surface. In addition, the 1,4- conjugate addition mechanism, which generates 3-phenyl-1-propen-1-ol (ENOL) that readily tautomerizes to HCAL, required less activation energy than did the C=C direct addition mechanism. The dominant reaction pathway involved an O atom of cinnamaldehyde preferentially hydrogenating to generate a more stable allyl intermediate. Another H atom then added to a C atom directly connected to the phenyl ring of the allyl intermediate to yield ENOL. Finally, ENOL tautomerized to HCAL. Throughout the process, the generation of ENOL is the rate-determining step, for which the highest activation energy barrier was required.

Alloy 800 is an important steamgenerator material used in nuclear power plants, and so there is significant interest in the properties of passive films of this alloy under service conditions. In this work, the semiconductivity of Alloy 800 in sulfate and chloride solutions was investigated using Mott-Schottky analysis, electrochemistry impedance spectroscopy (EIS), scanning electron microscopy (SEM), and scanning electrochemical microscopy (SECM). The Mott-Schottky results show that the semiconductivity is affected by the sulfate to chloride concentration ratio; p-type semiconductivity is exhibited at high concentration ratios but transitions to n-type when the concentration ratio is low. EIS, SEM, and SECM results indicate that the degradation formof the passive filmchanges fromtranspassive dissolution to pitting as the concentration ratio decreases while the film's surface reactivity increases, an effect that is related to the semiconductivity conversion. The observed variation in semiconductivity results fromthe competitive adsorption of sulfate and chloride, a process that modifies the potential drop at the film/solution interface, changes the vacancy types and ultimately determines the semiconductivity.

Reduced graphene oxide/sulfur (R /S) composites were synthesized by a one-step hydrothermal method using a mixture of sodium thiosulfate (Na₂S₂O₃) and graphene oxide ( ) solution reacting under acid conditions. We explored the influence of the hydrothermal temperature, reaction time, and sulfur content on the composites. Analysis by X-ray diffraction (XRD), scanning electron microscope (SEM), and the galvanostatic charge and discharge shows that the composites have excellent cycling performance when synthesis occurs at 180 ℃ for 12 h to provide a carbon:sulfur mass ratio of 3:7. The first discharge capacity is delivered at 931 mAh·g^-1 and it remains at 828.16 mAh·g^-1 after 50 cycles. The coulomb efficiency of the composites is above 95%. In addition, the rate capability of these composites is much better than that of sulfur. Sulfur molecules can be evenly distributed between the graphene layers and fixed to the functional groups on the surface of graphene by this one-step hydrothermal method.

We report on an ammonia-evaporation-induced synthetic method for nanostructured LiNi_1/3Co_1/3Mn_1/3O₂ cathode material. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high- resolution transmission electron microscopy (HRTEM), energy- dispersive X- ray spectroscopy (EDS), Brunauer-Emmett-Teller nitrogen sorption, and galvanostatic charge-discharge tests were applied to analyze the crystal structure, micromorphology, and electrochemical properties of nanostructured LiNi_1/3Co_1/3Mn_1/3O₂. The results show that it has a well-ordered layered α-NaFeO₂ with little cation mixing. Awalnutkernel- like morphology is formed by nanosheets, leading to a nanoporous material. The lateral plane of nanosheets are {010}-faceted, which could provide multiple channels for Li⁺-ion migration. The electrochemical properties of the lithium cells used this material as cathode are excellent: the specific discharge capacity at 0.5C,1C, 3C, 5C and 10C is, respectively, up to 172.90, 153.95, 147.09, 142.16, and 131.23 mAh·g^-1 between 3.0 and 4.6 V at room temperature. These excellent features will make the nanostructured LiNi_1/3Co_1/3Mn_1/3O₂ become a positive electrode material of potential interest for useful applications, such as in electric vehicles and hybrid electric vehicles.

The pH of the solution used to produce an electro- polymerized polypyrrole (PPy) film has a significant impact on the morphology and properties of the resulting film and, by extension, on the electrocatalytic activity of the film for the I^-/I₃^- redox reaction. Accordingly, the performance of dye-sensitized solar cells (DSSCs) based on PPy counter electrodes (CEs) is affected by solution pH. In this study, p-toluene sulfonate ion-doped PPy (PPy-TsO) CEs on fluorine-doped tin oxide (FTO) glass substrates were fabricated using an electrochemical method under a constant bias in solutions with various pH values. The effect of the pH of the synthetic solution on the morphology, structure, and electrocatalytic activity during the I^-/I₃^- redox reaction of the obtained PPy CEs was thoroughly investigated by scanning electron microscopy (SEM), UV-Vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV). A pH value of 2.0 was found to represent the optimal value, since the PPy-TsO film produced at this pH exhibited the highest degree of doping, the longest conjugation length, and the highest catalytic activity. When working as the CE of a DSSC, this film also showed the highest power conversion efficiency. Films synthesized at pH values either above or below 2.0 exhibited inferior properties and lower performance when in DSSCs.

To improve the light-to-electric conversion efficiency of quantum dots-sensitized nanocrystalline thin-film solar cells, a PbS electrode with high electrocatalytic activity toward polysulfide electrolyte was prepared by successively treating Pb foil in acid and polysulfide solutions. Electrochemical impedance spectroscopy (EIS) measurements were performed to evaluate the electrocatalytic activity of the prepared PbS electrode. Based on the EIS results, the temperature and time to treat the Pb foil in the acid solution were optimized. The PbS electrode prepared under the optimized conditions was used as a counter electrode to fabricate a quantumdotssensitized solar cell with a CdSe quantum dots-sensitized TiO₂ nanocrystalline thin film as the photoanode and polysulfide solution as the electrolyte. Both the electrocatalytic activity and light-to-electric conversion properties of the PbS electrode prepared from acid treatment of Pb foil for the optimized temperature and time are superior to those of electrodes prepared by other reported methods. In our method, the treatment time is considerably less but the PbS counter electrode maintains a superior catalytic activity compared with other methods. X-ray diffraction and scanning electron microscopy were performed to demonstrate the formation process of PbS, and the catalytic enhancement mechanism of the prepared PbS electrode is discussed.

Six-hydrogen-bonded oli aramide heteroduplexes demonstrate extremely high sequencespecificity and tunable stability during their self-assembly. The self-assembly behavior of molecular oli aramide 1 arrayed in a DADDAD-DADDAD sequence and that in the presence of oli aramide 2 with an ADAADAADAADA sequence were examined using multiple techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). Results from these experiments indicate that 1 can self-assemble to vesicles with uniform shapes in both tetrahydrofuran/methanol (V/V, 85/15) and acetone, the size of which increased with an increase in solution concentration. Upon addition of the corresponding complementary 2, the vesicles turned into solid balls. Fluorescence microscopy experiments revealed that the vesicles were able to encapsulate the fluorescence molecules (Rhodamine B). With further modification of molecular structures, these vesicles may hold potential for applications as drug carrier as well as in controlled-release technology.

The wettability, surface topography, surface potential, and degree of order of a homogeneously mixed octyltriethoxysilane (C8TES)/octadecyltrichlorosilane (OTS) self-assembled monolayer (SAM) were characterized by means of contact angle analysis, atomic force microscopy (AFM), electrostatic force microscopy (EFM), and Fourier transform infrared (FTIR) spectroscopy. The formation mechanism of the SAM was studied as the monolayer was constructed using a stepwise approach, taking advantage of the steric hindrance of C8TES. The SAM was found to have a contact angle of 105° and the formation process of the mixed SAM was obviously different from the SAM formation mechanisms of both pure C8TES and OTS. The AFM and EFM characterizations indicated that the mixed SAM had a smooth surface and a homogeneous surface potential distribution with a typical, normal surface potential frequency distribution. The internal structure was highly homogeneous over regions ranging from 500 nm×500 nm to 20 μm×20 μm in size. The FTIR analysis indicated that the mixed SAM had a double-layer film structure, and that the molecular densities were different in the two layers, with the layer closer to the substrate being denser. This work shows that steric hindrance effects can be used to allow the stepwise formation of homogeneously mixed SAMs, and that this method is especially applicable to the construction of the homogeneously mixed SAMs composed of two types of molecules having different head groups.

A microspherical ZSM-5 zeolite aggregated from nanosized zeolite crystals with intra- and intercrystalline mesoporous structures (MMZ- 5) was prepared using presilanized silica as silica source. The acidic properties of this mesoporous zeolite were characterized via Fourier transform infrared spectroscopy (FTIR) in combination with pyridine (Py) and 2,6-di-tert-butylpyridine (DTBPy). Compared with conventional microporous ZSM- 5, the MMZ- 5 zeolite possessed more Lewis acid sites and many more accessible Brönsted acid sites for bulky DTBPy molecule (1.05 nm in diameter). This mesoporous zeolite thus afforded both effective active sites and reaction voids allowing the reaction of larger molecules, resulting in enhanced catalytic activity and stability of the MMZ-5 zeolite during the benzylation of naphthalene with benzyl chloride (BC) to form bulky monobenzylnaphthalenes and dibenzylnaphthalenes, during which the selectivity for monobenzylnaphthalenes was estimated to be about 79%. Moreover, the selectivity for dibenzylnaphthalenes was enhanced with increasing reaction time, owing to the consecutive reactions between monobenzylnaphthalenes and BC occurring at the effective reaction voids of the MMZ-5 zeolite. The distribution of the monobenzylnaphthalene isomers (α-BN and β-BN) was found to be independent of both reaction temperature and extent of BC conversion, the α-BN/β-BN molar ratio being about 83:17.

A series of tungsten-based catalysts were synthesized via a traditional impregnation method using SBA-15, hexa nal mesoporous silica (HMS), and SnO₂ as the support. The supported catalysts were characterized by X-ray powder diffraction (XRD), transmission electron microscopy/field-emission transmission electron microscopy (TEM/FETEM), UV-Vis diffuse reflection spectroscopy (UV-Vis DRS), Raman spectrometry, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. It was found that the support was crucial to the dispersion and nature of the tungsten species on the catalyst. In this study, the catalytic performances of catalysts with different supports were investigated for the synthesis of adipic acid (AA) from the selective oxidation of cyclohexene oxide. The excellent catalytic performance of the catalyst was obtained over WO₃/SnO₂, followed by WO₃/HMS and WO₃/SBA-15. The XRD results indicate that the degree of crystallinity of the tungsten species of WO₃/SnO₂ catalyst was low and the particle size of WO₃ was small (~2 nm). TEM and XPS results imply a high dispersion of tungsten species on the SnO₂ support. The UV-Vis DRS spectra demonstrate the existence of [WO₄] and low-polymeric tungsten species. In addition, the W-based catalyst with SnO₂ as the support could retain high activity, even after being reused six times, suggesting that there is strong interaction between tungsten species and the SnO₂-support that enhanced the stability of the catalyst. This shows the potential of the WO₃/SnO₂ as a catalyst for the synthesis of adipic acid.

Highly ordered TiO₂ nanotube arrays (TNAs) were fabricated by an electrochemical anodization process and Cu₂O nanoparticles were subsequently deposited onto these TNAs via pulse deposition to form Cu₂O/TiO₂ nanotube heterojunction composite materials. Samples were characterized by field emission scanning electron microscopy (FESEM), field emission transmission electron microscopy (FETEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffusion reflection spectroscopy (DRS). The photocatalytic performances of the Cu₂O/TiO₂ composites were investigated by following the visible-light induced photocatalytic decomposition of methyl orange (MO). The results indicated that the inner surfaces and interfaces of the TNAs had been successfully modified with uniformly distributed Cu₂O nanoparticles, and that these composites could effectively improve the visible light photocatalytic performance. The Cu₂O/TiO₂ nanotube composite obtained using 0.01 mol·L^-1 CuSO₄ solution exhibited the best photocurrent and photocatalytic performance. Based on the results obtained, a possible photocatalytic mechanism is also discussed.

In-Si co-modified TiO₂ photocatalysts were synthesized via a microwave-assisted solvothermal method. The obtained materials were characterized by X-ray diffraction (XRD), Raman spectroscopy, N₂ addesorption (BET), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy, and UVVis diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalysts all exist in an anatase phase, despite the fact that the crystallinity slightly decreased upon modification of the TiO₂ photocatalysts. Si-modification resulted in smaller nanoparticles and larger specific surface areas. In-modification led to the formation of In₂O₃ on the surface of TiO₂, such that In cannot enter the TiO₂ lattice, contributing to efficient charge transfer between the coupled semiconductors In₂O₃ and TiO₂. Degradation of Rhodamine B (RhB) showed that In-Si co-modified TiO₂ photocatalysts can exhibit high photocatalytic activity under both ultraviolet and visible light. The highest activity was obtained for In-Si co-modified TiO₂ with an Si:In:Ti molar ratio of 0.03:0.02:1 (IST-2), with which RhB was completely degraded within 3 min under ultraviolet light and where 97% of RhB was degraded after 120 min under visible light. The improved photocatalytic activity of In- Si co-modified TiO₂ may be ascribed to synergistic effects between large surface area, efficient electron transmission at the In₂O₃-TiO₂ interface, and the dye sensation effect of RhB. Photodegradation for colorless phenol occurred at a much slower rate than that for RhB, and the phenol did not completely degrade within 700 min.

A BaFeO_3-x+Cu-ZSM-5 coupled catalyst was designed and synthesized to eliminate the NO_x emitted from lean-burn exhausts, providing an alternative to the traditional noble-metal-based NO_x storage reduction (NSR) catalysts. During the lean-burn period, the NO oxidation and storage processes mainly occurred over the BaFeO_3-x catalyst. During the fuel-rich period, the released NO_x from the BaFeO_3-x catalyst was further reduced over the Cu-ZSM-5 catalyst. Our results show that, compared with the BaFeO_3-x and Cu-ZSM-5 catalyst alone, the operating temperature window of the coupled BaFeO_3-x+Cu-ZSM-5 catalyst is extended from 250 to 400 ℃, and its NO_x elimination performance is significantly improved. The maximum NO_x conversion of the coupled catalyst was 98%, while the N₂ selectivity was close to 100%.

The present work investigated the effects of two types of CeO₂ materials on the lean NO_x trap (LNT) performance over NO_x storage reduction (NSR) catalysts below 300 ℃. These materials were obtained by mechanical mixing of 2% (w) Pt/Al₂O₃ (PA) with CeO₂-X (X=S, I). X-ray diffraction (XRD), BET surface area measurements, and scanning electron microscopy (SEM) were used to characterize the physical structures of the catalysts, while X-ray photoelectron spectroscopy (XPS) and H₂ temperature-programmed reduction (H₂-TPR) were employed to identify and quantify the surface Ce³⁺ concentrations and the amounts of surface-active oxygen. In-situ diffuse reflectance infrared Fourier transform spectroscopy (In-situ DRIFTS) was applied to analyze the surface adsorbed NO_x species. Compared with CeO₂-I, CeO₂-S presented superior physico-chemical properties, including higher surface area, richer porous texture, stronger aging-resistance, and higher surface Ce³⁺ concentration. As a result, the PA+CeO₂-S sample also exhibited outstanding NO_x trapping capacity. Furthermore, interaction between Pt and CeO₂ was observed in the PA+CeO₂-X mixtures, which facilitates NO oxidation and the NO_x trapping process owing to the accompanying increase in the activity of surface active oxygen on the CeO₂. This interaction was stronger in the case of the PA+CeO₂-S sample as compared with the PA+CeO₂-I. The Ce³⁺ content and presence of active oxygen species on the CeO₂ surface both play critical roles in the NO_x trapping process and hydrothermal treatment of the CeO₂ significantly decreased the NO_x trapping capacity of both PA+CeO₂ samples. It was also determined that the interaction between Pt and aged CeO₂ is weakened and that the NO_x trapping capacity of aged CeO₂ is enhanced after loading a small amount of Pt, which is attributed to the promotion of nitrate formation by increased surface oxygen activity.

This study investigated the effects of NO₂ on the selective catalytic reduction (SCR) of NO by NH₃ over Cu/SAPO-34 catalyst at temperatures ranging from 100 to 500 ℃. The Cu/SAPO- 34 sample was hydrothermally treated at 750 ℃ for 4 h to obtain a de-greened sample and X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the structure of the catalyst. SCR activity test, kinetic analysis, and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ-DRIFTS) were all applied to evaluate the changes in catalytic activity in the presence of various NO/NO₂ ratios. The SCR results for different NO/NO₂ molar ratios demonstrated that NO₂ inhibited the NO_x removal efficiency over the Cu/SAPO- 34 catalyst at low temperatures (100-280 ℃), but enhanced the efficiency at high temperatures (above 280 ℃). The amount of N₂O was observed to increase with decreasing NO/NO₂ ratios, owing to the decomposition of NH₄NO₃. The kinetic results showed that the fast SCR reaction exhibited a higher apparent activation energy (E_a=64.02 kJ·mol^-1) than that of the standard SCR reaction (E_a=48.00 kJ·mol^-1) over Cu/SAPO-34 catalyst. The results of in situ-DRIFTS showed that NO₂ did not efficiently generate nitrate species on Cu2+ sites compared with NO, and that some nitrate species combined with NH₄₊ on Brønsted acid sites to generate NH₄NO₃. The inhibitory effect of NO₂ at low temperatures is evidently caused by deposited NH₄NO₃ covering the active sites of Cu/SAPO-34 catalyst, while these NH₄NO₃ species can be reduced by NO or thermally decomposed as the temperature increases.

Photofragment (NO⁺ and N₂⁺) excitation (PHOFEX) spectra of N₂O⁺ via B²П_i←X²Π transitions was obtained over the wavelength range from 230 to 275 nm by preparing N₂O⁺(X²Π(000)) ions via [3+1] resonance enhanced multiphoton ionization of N₂O molecules at 360.50 nm. On the basis of the approximation of harmonic oscillation between N and NO or between N₂ and O, the Franck-Condon factors for the B²П_i(00n)←X²Π(000) transitions of N₂O⁺ ions were calculated using the potential curves and wavefunctions of the harmonic oscillator. The results of such calculations were compared with the photodissociation spectra of the B²П_i(00n)←X²Π(000) transition so as to estimate the validity of the rotational constants and the bond length of the B²П_i state obtained from previous studies. The photodissociation mechanism of the B²П_i(00n)←X²Π(000) transitions of N₂O⁺ ions and the product branching ratios were also discussed.

Dicyclohexano-18-crown-6 ether (DCH18C6) is an efficient extractant for the removal of ⁹⁰Sr from liquid radioactive waste. Because the structure and extractability of DCH18C6 might be affected by radiation during practical application, it is necessary to investigate the radiation stability of the complex ofh Sr²⁺ with DCH18C6. In this work, a single crystal of Sr(NO₃)₂·DCH18C6 complex was synthesized and characterized by X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS). The coordination number of Sr²⁺ proved to be 10, including six crown ether O atoms and four O atoms from two bidentate nitrate groups. The average Sr―O bond length is 0.268 nm or 0.266 nm, as determined by XRD or EXAFS, respectively. EXAFS spectra proved that the coordination number and the Sr―O bond length of the complex were slightly affected by irradiation for 400 kGy. Although the micro-Fourier-transform infrared spectra indicated that some C―H bonds were oxidized to hydroxyl or carbonyl, the coordination shell of Sr²⁺ and DCH18C6 was not damaged, indicating od radiation stability of the Sr(NO₃)₂·DCH18C6 complex.

We investigated the binding process of fullerene to fibril-like Aβ42 oli mers by performing multiple molecular dynamics simulations. It was observed that the C₆₀ molecule searched a series of positions on the surfaces of the Aβ42 oli mers before finding a stable binding state. Multi-binding sites have been identified and these can be classified into six types according to the type of residue in contact with the fullerene. The sites near the central hydrophobic core (CHC) (¹⁷LVFFA²¹) and the turn region (²⁷NKGAI³¹) were identified as the most suitable sites with the lowest associated binding energies. These bound states were primarily stabilized by van der Waals interactions, while the solvation effect acted as a destabilizing factor.