Calculations of Chemical Reaction Dynamics for D+ H_2(j_i,ν_i=0)→DH(j_f, ν_f=0) + H

The constant Centrifugal potential approximation is Corrected so as to apply to the reactions of rotational excited reactants for D + H2 (j,, νi = 0 ) -DH(jf, νf = 0) + H. Our results show that the contributions from ji≠0 and Ωi terms are not negligible.

Dynamic chemical processes on ZnO surfaces tuned by physisorption under ambient conditions

The catalytic properties of non-reducible metal oxides have intrigued continuous interest in the past decades.Often time,catalytic studies of bulk non-reducible oxides focused on their high-temperature applications owing to their weak interaction with small molecules.Hereby,combining ambient-pressure scanning tunneling microscopy(AP-STM),AP X-ray photoelectron spectroscopy(AP-XPS)and density functional theory(DFT)calculations,we studied the activation of CO and CO_(2)on ZnO,a typical nonreducible oxide and major catalytic material in the conversion of C1 molecules.By visualizing the chemical processes on ZnO surfaces at the atomic scale under AP conditions,we showed that new adsorbate structures induced by the enhanced physisorption and the concerted interaction of physisorbed molecules could facilitate the activation of CO and CO_(2)on ZnO.The reactivity of ZnO towards CO could be observed under AP conditions,where an ordered(2×1)–CO structure was observed on ZnO(1010).Meanwhile,chemisorption of CO_(2)on ZnO(1010)under AP conditions was also enhanced by physisorbed CO_(2),which minimizes the repulsion between surface dipoles and causes a(3×1)–CO_(2)structure.Our study has brought molecular insight into the fundamental chemistry and catalytic properties of ZnO surfaces under realistic reaction conditions.

Chemical abundance analysis of 19 barium stars

We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium（Ba） stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences. The chemical abundances of the sample stars were obtained from an LTE, plane-parallel and line-blanketed atmospheric model by inputting the atmospheric parameters（effective temperatures Teff, surface gravities log g, metallicity [Fe/H] and microturbulence velocity ξt） and equivalent widths of stellar absorption lines. These samples of Ba stars are giants as indicated by atmospheric parameters, metallicities and kinematic analysis about UVW velocity. Chemical abundances of 17 elements were obtained for these Ba stars. Their Na, Al, α- and iron-peak elements（O, Na, Mg, Al, Si, Ca,Sc, Ti, V, Cr, Mn, Ni） are similar to the solar abundances. Our samples of Ba stars show obvious overabundances of neutron-capture（n-capture） process elements relative to the Sun. Their median abundances of[Ba/Fe], [La/Fe] and [Eu/Fe] are 0.54, 0.65 and 0.40, respectively. The Y I and Zr I abundances are lower than Ba, La and Eu, but higher than the α- and iron-peak elements for the strong Ba stars and similar to the iron-peak elements for the mild stars. There exists a positive correlation between Ba intensity and [Ba/Fe].For the n-capture elements（Y, Zr, Ba, La）, there is an anti-correlation between their [X/Fe] and [Fe/H]. We identify nine of our sample stars as strong Ba stars with [Ba/Fe]〉0.6 where seven of them have Ba intensity Ba=2-5, one has Ba=1.5 and another one has Ba=1.0. The remaining ten stars are classified as mild Ba stars with 0.17〈[Ba/Fe]〈0.54.

Time-dependent density functional theoretical studies on the photo-induced dynamics of an HCI molecule encapsulated in C60 under femtosecond laser pulses

By using first-principles simulations based on time-dependent density functional theory, the chemical reaction of an HCl molecule encapsulated in C60 induced by femtosecond laser pulses is observed. The H atom starts to leave the Cl atom and is reflected by the C60 wall. The coherent nuclear dynamic behaviors of bond breakage and recombination of the HCl molecule occurring in both polarized parallel and perpendicular to the H-Cl bond axis are investigated. The radial oscillation is also found in the two polarization directions of the laser pulse. The relaxation time of the H-Cl bond lengths in transverse polarization is slow in comparison with that in longitudinal polarization. Those results are important for studying the dynamics of the chemical bond at an atomic level.

Change in Continuous Detonation Wave Propagation Mode from Rotating Detonation to Standing Detonation

We perform a three-dimensional numerical simulation based on a one-step chemical reaction model to investigate changes in the mode of H2-Air detonation wave propagation from rotating detonation wave （RDW） mode to standing detonation wave mode. The physical characteristics of an RDW with injection velocity of 500 m/s are analyzed to investigate the physical mechanisms involved. We find that with increasing injection velocity, the detonation wave gradually changes from perpendicular to the head wall to parallel to the head wall. When the injection velocity exceeds the Chapman-Jouguet velocity VCJ （about 1984 m/s）, the detonation wave changes orientation to become perpendicular to the fuel injection direction, and the rotating mode changes accordingly to a standing mode. Finally, the plane detonation characteristic triple-wave structures can be found from the standing mode.

Theoretical Studies on Formation Mechanism of Resonance States for Na+I_2→Na^++I_2^-System

An extended linear combination of arrangement channels-scattering wave-function(LCAC-SW) quantum scattering dynamic method combined with ab initio quantum chemical calculation was used to study the formation mechanism of the resonance states for the collinear Na+I 2→Na ++I - 2 ion-pair formation process on Aten-Lanting-Los potential energy surface. The resonance energy and the resonance width or the lifetime for the first resonance peak were calculated. The resonance can be identified as the Feshbach type and the physical interpretation is given. The geometric structure of the resonance state for the title system has been optimized.

Chemically induced dynamic electron polarization investigation of the triplet-radical system in the solution of the triplet quencher

The chemically induced dynamic electron polarization (CIDEP) of the triplet molecule/triplet quencher/2, 2, 6, 6-tetramethyl-1-piperidinyloxyl (TEMPO) systems were measured using the high time-resolved ESR spectrometer. The competition between the radical-triplet pair mechanism (RTPM) and triplet mechanism (TM) or radical pair mechanism (KIM) polarization in the solution of the triplet quencher was investigated, and the relationships between reaction rate of the radical-triplet pair and quenching rate of triplet was deduced.

Effect of a high strength chemical industry wastewater on microbial community dynamics and mesophilic methane generation

A high strength chemical industry wastewater was assessed for its impact on anaerobic microbial com- munity dynamics and consequently mesophilic methane generation. Cumulative methane production was 251 mL/g total chemical oxygen demand removed at standard temperature and pressure at the end of 30 days experimental period with a highest recorded methane percentage of 80.6% of total biogas volume. Volatile fatty acids （VFAs） analysis revealed that acetic acid was the major intermediate VFAs produced with propionic acid accumulating over the experimental period. Quantitative analysis of microbial communities in the test and control groups with quantitative real time polymerase chain reaction highlighted that in the test group, Eubacteria （96.3%） was dominant in comparison with methanogens （3.7%）. The latter were dominated by Methanomicrobiales and Methanobacteriales while in test groups increased over the experimental period, reaching a maximum on day 30. Denaturing gradient gel electrophoresis profile was performed, targeting the 16S rRNA gene of Eubacteria and Archaea, with the DNA samples extracted at 3 different time points from the test groups. A phylogenetic tree was constructed for the sequences using the neighborhood joining method. The analysis revealed that the presence of organisms resembling Syntrophomonadaceae could have contributed to increased production of acetic and propionic acid intermediates while decrease of organisms resembling Pelotomaculum sp. could have most likely contributed to accumulation of propionic acid. This study suggested that the degradation of organic components within the high strength industrial wastewater is closely linked with the activity of certain niche microbial communities within eubacteria and methanogens.

Multidisciplinary and multiscale nanoscience research roadmap based on large scientific facilities

With the advancement of modern science and technology, large scientific facilities are increasingly oriented toward demand and application, and can be used for basic research as well as serving multiple disciplines. Developing large scientific facilities and related analytical technologies enhances understanding of large scientific facilities and popularizes their application in research across multiple disciplines. The combination of light or neutron sources from large scientific facilities and advanced analytical technologies can be achieved for materials structure information, dynamics study of chemical reactions, high dissociation of biomolecules, 3D visualization of energy materials or biological samples, etc. We first introduce the progress of domestic large scientific facilities of synchrotron radiation(SR) and free electron lasers(FELs) with different wavelengths and neutron sources.We further discuss the comparison between Chinese and typical foreign facilities in X-ray radiation from X-ray tubes, synchrotrons, X-ray FELs, and neutron sources based on physical parameters of light and neutron sources. In addition, we focus on the technological progress and perspectives combined with advanced X-ray radiation and neutron sources of large scientific facilities in China, especially in the nanoscience fields of energy catalysis and biological science. We hope that this roadmap will provide references on technology and methods to experimental users, as well as prospects for future development of technologies based on large research infrastructure facilities. Comprehensive studies and guidelines for basic research to practical application in various disciplines can be made with the assistance of large scientific facilities.

Reversible grafting of antibiotics onto contact lens mediated by labile chemical bonds for smart prevention and treatment of corneal bacterial infections

Eye trauma, decreased immunity, and contact lens wear often cause serious bacterial infections and irreversible corneal damage. To realize the responsive release of antibiotics such as gentamicin sulfate(GS), a novel antibacterial contact lens was constructed through self-assembly of antibiotics loaded ADAGS/PEI(polyethyleneimine) multilayer films on the surface. Both in vitro and in vivo antibacterial tests demonstrated high efficient and fast antibacterial property based on the smart responsive to bacterial infections and reversible drug loading and release.

Modeling and simulation of chemically reacting flows in gas-solid catalytic and non-catalytic processes

This paper gives an overview of the recent development of modeling and simulation of chemically react- ing flows in gas-solid catalytic and non-catalytic processes. General methodology has been focused on the Eulerian-Lagrangian description of particulate flows, where the particles behave as the catalysts or the reactant materials. For the strong interaction between the transport phenomena （i.e., momentum, heat and mass transfer） and the chemical reactions at the particle scale, a cross-scale modeling approach, i.e., CFD-DEM or CFD-DPM, is established for describing a wide variety of complex reacting flows in multiphase reactors, Representative processes, including fluid catalytic cracking （FCC）, catalytic conversion of syngas to methane, and coal pyrolysis to acetylene in thermal plasma, are chosen as case studies to demonstrate the unique advantages of the theoretical scheme based on the integrated particle-scale information with clear physical meanings, This type of modeling approach provides a solid basis for understanding the multiphase reacting flow problems in general.

Oxygen promoted hydrogen production from formaldehyde reforming with oxide-derived Cu nanowires at room temperature

This work demonstrates a two-step method to produce oxide-derived Cu nanowires on Cu mesh surface to offer a monolithic catalyst that outstandingly improves the hydrogen production from reforming formaldehyde and water under ambient conditions.Our results not only reveal that the special oxidederived nanostructure can significantly improve the formaldehyde reforming performance of Cu,but also display that the hydrogen production has a linear relationship with oxygen pressure.Specially,a maximum of 36 times increment in hydrogen generation rate is observed than that without oxygen during the reaction.Density functional theory calculations show that the formaldehyde molecule is adsorbed on Cu surface only when the adsorbed oxygen is in adjacency,and hydrogen release process is the ratedetermining step.This work highlights that the activity of deliberately synthesized catalyst can further be promoted by dynamic chemical modulation of surface states during working.

Design and therapeutic application of sodium alginate-based hydrogel with biodegradability and catalytic activity

How to efficiently treat cancer in a minimally invasive manner has become one of the major focuses of recent developments in biomedicine.In this research,biodegradable sodium alginate(SA)hydrogel encapsulated with NaHCO_(3)and glucose oxidase(GOX)was synthesized using Fe^(3+)as the crosslinker for the tumor chemodynamic therapy(CDT)and starvation therapy(ST).Material safety assessments revealed that this hydrogel possesses good in vitro and in vivo security.In tumor microenvrionment(TME),the Fe^(3+)further reacted with the intracellular glutathione and was transformed into Fe^(2+),which triggered the Fenton reaction with the H_(2)O_(2)within TME and produced abundant highly toxic·OH(hydroxyl radicals)for efficient tumor CDT.Furthermore,the GOXcatalyzed the enzymolysis of glucose to consume the nutrient of the tumor and enhance the H_(2)O_(2)level in TME.Besides,the CO_(2)bubbles that were generated from the decomposing of NaHCO_(3)promoted the contact between glucose and GOX.Findings in this research would have important implications for the present status of tumor therapy.