Precisely Control Relationship between Sulfur Vacancy and H Absorption for Boosting Hydrogen Evolution Reaction

Ef fective and robust catalyst is the core of water splitting to produce hydrogen.Here, we report an anionic etching method to tailor the sulfur vacancy(VS) of NiS_(2) to further enhance the electrocatalytic performance for hydrogen evolution reaction(HER). With the VS concentration change from 2.4% to 8.5%, the H* adsorption strength on S sites changed and NiS_(2)-VS 5.9% shows the most optimized H* adsorption for HER with an ultralow onset potential(68 m V) and has long-term stability for 100 h in 1 M KOH media. In situ attenuated-total-reflection Fourier transform infrared spectroscopy(ATR-FTIRS) measurements are usually used to monitor the adsorption of intermediates. The S-H* peak of the Ni S_(2)-VS 5.9% appears at a very low voltage, which is favorable for the HER in alkaline media. Density functional theory calculations also demonstrate the Ni S_(2)-VS 5.9% has the optimal |ΔG^(H*)| of 0.17 e V. This work offers a simple and promising pathway to enhance catalytic activity via precise vacancies strategy.

应用大分子促进剂的H型水合物储氢特性的分子动力学模拟

纯氢气水合物形成的温压条件极为苛刻(低温高压),限制了其工业应用,而氢气和甲烷混合气水合物形成的温压条件相对温和。通过恒温恒压(NPT)系综分子动力学模拟,研究了环庚酮(C_(7)H_(12)O)、甲基环己烷(C_(6)H_(11)-CH_(3))、1,1-二甲基环己烷(1,1-C_(8)H_(16))和1,2-二甲基环己烷(1,2-C_(8)H_(16))4种大分子促进剂对H型纯氢气水合物以及氢气和甲烷混合气水合物稳定性的影响。结果表明,分别应用4种大分子促进剂的H型水合物牢笼稳定性从大到小依次为1,1-C_(8)H_(16)、1,2-C_(8)H_(16)、C_(6)H_(11)-CH_(3)和C_(7)H_(12)O。相比于纯氢气,氢气和甲烷混合气能够极大缓和热力学条件(温度升高,压力降低)。两种同分异构体(1,1-C_(8)H_(16)和1,2-C_(8)H_(16))作为大分子促进剂,对应的热力学条件表现出较大差异。在纯氢气水合物中,两种同分异构体作为大分子促进剂所需温度条件相近(270 K),而1,1-C_(8)H_(16)作为大分子促进剂所需压力条件(60 MPa)低于1,2-C_(8)H_(16)(100 MPa)。在氢气和甲烷混合气水合物中,1,1-C_(8)H_(16)作为大分子促进剂所需温度条件(270 K)高于1,2-C_(8)H_(16)(260 K),所需压力条件(20 MPa)低于1,2-C_(8)H_(16)(40 MPa)。

硫化氢在H型高血压中的研究进展

硫化氢(hydrogen sulfide,H_(2)S)是一种参与血管张力调节的内源性气体传递素,具有多种生理特性,如抗高血压、血管松弛、抗炎和抗氧化潜能,在心血管调节中发挥重要作用。同型半胱氨酸(homocysteine,HCY)与心血管疾病的发生、发展密切相关。高同型半胱氨酸血症(HCY≥10μmol·L^(-1))是冠状动脉粥样硬化性心脏病、脑卒中等心脑血管疾病的危险因素,中国学者将伴有高同型半胱氨酸血症的原发性高血压定义为H型高血压,约占我国成年高血压患者的75%。H型高血压的治疗应同时降低血压和血浆HCY的水平。研究表明,H_(2)S能够拮抗高血压和高HCY,提示H_(2)S可能成为H型高血压的潜在治疗靶点。因此,该文就H_(2)S对高血压和HCY的作用机制进行总结。

一种新1H-1,2,3-三唑-4-甲酰胺化合物的合成、晶体结构和氢键研究

合成了一种新的5-甲基-N,1-(二-对甲苯基)-1H-1,2,3-三唑-4-甲酰胺化合物并研究了晶体结构和氢键构成.通过元素分析、核磁共振、质谱、红外光谱对目标化合物进行了表征.化合物的化学式为C_(18)H_(18)N_(4)O,Mr=306.36,晶体属于单斜晶系P21/c空间群中,其晶胞参数为a=1.03251(3)nm,b=0.74042(2)nm,c=2.11902(6)nm,α=90°,β=99.1250(10)(°),γ=90°,V=1.59947(8)nm^(3),Dx=1.272 g5cm^(-3),Z=4.最终R值为0.0429.对目标化合物的芳香体系和氢键体系进行了讨论,并展示了分子晶体在不同平面方向的密堆积.

2-Ethyl-9,10-anthraquinone assisted sol–gel synthesis of Pd/γ-Al2O3 nanorods with enhanced catalytic performance in 2-ethyl-9,10-anthraquinone hydrogenation

A series of nanorod-like porous Pd/γ-Al2 O3 catalysts with controllable textural properties and enhanced catalytic performance in 2-ethyl-9,10-anthraquinone(eAQ) hydrogenation for H2 O2 preparation were successfully prepared via a facile sol-gel method using aluminum isopropoxide as aluminum precursor and eAQ as structure directing agent,sequential calcination and impregnation process with Na2 PdCl4 solution.The physicochemical properties of the catalysts obtained with different addition amounts of eAQ.were comparatively characterized by XRD,TG-DSC,BET,TEM,CO-TPR,H2-TPR and H2-O2 titration.The results show that addition of eAQ can not only effectively control the textural properties(surface area,pore volume and average pore size) of the catalysts,but also lower their reduction temperature of active metal.Importantly,the catalyst obtained with an addition amount of 4 wt% eAQ shows the highest hydrogenation efficiency of 10.28 g·L^-1,which is 37.3% higher than 7.49 g·L^-1 of the catalyst obtained without eAQ.

Study on stability of hydrogenated amorphous silicon films

Hydrogenated amorphous silicon （a-Si：H） films with high and same order of magnitude photosensitivity （-10^5） but different stability were prepared by using microwave electron cyclotron resonance chemical vapour deposition system under the different deposition conditions. It was proposed that there was no direct correlation between the photosensitivity and the hydrogen content （CH） as well as H-Si bonding configurations, but for the stability, they were the critical factors. The experimental results indicated that higher substrate temperature, hydrogen dilution ratio and lower deposition rate played an important role in improving the microstructure of a-Si：H films. We used hydrogen elimination model to explain our experimental results.

Multi-technique integration separation frameworks after steam reforming for coal-based hydrogen generation

Coal-based H2 generation has abruptly increased in recent years.The PSA-VPSA-SC process is the matured and standard framework for H2 purification and CO_(2) capture in many existing plants,including normal and vacuum pressure swing adsorption units in series(PSA-VPSA),and shallow condensation unit(SC).However,this standard process is frequently subjected to low H2 recovery ratio and high purification cost.In this work,H2-selective and C02-selective membrane units,i.e.,HM and CO_(2) M,are attempted to support the standard process and ameliorate constraints.In the beginning,HM unit is arranged after VPSA to enhance H2 recovery from the decarbonized stream,i.e.,the PSA-VPSA-SC/HM process.As a result,H2 recovery ratio can be enhanced significantly from 83%to 98%.In the following,VPSA is replaced with CO_(2) M unit to reduce investment and operation cost,i.e.,the PSA-CO_(2) M-SC/HM process.Accordingly,the specific purification cost is diminished from 33.46 to 32.02 USD·(103 m^(3) H_(2))-1,saved by 4.3%,meanwhile the construction cost is falling back and just a little higher than that for the standard process.In the end,another CO_(2) M unit is launched before PSA,i.e.,the CO_(2) M-PSA-CO_(2) M-SC/HM process,which could unbundle CO_(2) enrichment partially from H2 purification,and then save more investment and operation cost.In comparison with the standard process,this ultimate retrofitted process can be superior in all the three crucial indices,i.e.,recovery ratio,investment,and specific purification cost.On the whole,coal-based H2 generation can be ameliorated significantly through high efficient H2-selective and CO_(2)-selective membrane units.

Renewable hydrogen production from steam reforming of glycerol(SRG)over ceria-modified Y-alumina supported Ni catalyst

Excess crude glycerol derived as a by-product from biodiesel industry prompts the need to valorise glycerol to value-added chemicals.In this context,catalytic steam reforming of glycerol(SRG) was proposed as a promising and sustainable alternative for producing renewable hydrogen(H2).Herein,the development of nickel(Ni) supported on ceria-modified mesoporous γ-alumina(γ-Al2 O3) catalysts and their applications in catalytic SRG(at550-750℃ atmospheric pressure and weight hourly space velocity,WHSV,of 44,122 ml·g^-1·h^-1(STP)) is presented.Properties of the developed catalysts were characterised using many technique s.The findings show that ceria modification improved Ni dispersion on γ-Al2 O3 catalyst support with highly active small Ni particles,which led to a remarkable catalytic performance with the total glycerol conversion(ca.99%),glycerol conversion into gaseous products(ca.77%) and H2 yield(ca.62%).The formation rate for H2 production(14.4 ×10^(-5)mol·s^-1·g^-1, TOF(H2)=3412 s^-1) was significantly improved with the Ni@12 Ce-Al2 O3 catalyst,representing nearly a 2-fold increase compared with that of the conventional Ni@AI2 O3 catalyst.In addition,the developed catalyst also exhibited comparatively high stability(for 12 h) and coke resistance ability.

Research on the optimum hydrogenated silicon thin films for application in solar cells

Hydrogenated silicon （Si：H） thin films for application in solar ceils were deposited by using very high frequency plasma enhanced chemical vapour deposition （VHF PECVD） at a substrate temperature of about 170 ℃, The electrical, structural, and optical properties of the films were investigated. The deposited films were then applied as i-layers for p-i-n single junction solar cells. The current-voltage （I - V） characteristics of the cells were measured before and after the light soaking. The results suggest that the films deposited near the transition region have an optimum properties for application in solar cells. The cell with an i-layer prepared near the transition region shows the best stable performance.

Theoretical Studies on the Stabilities and Hydrogen Bond Actions of (H_2O)_n Clusters

The stable configurations and hydrogen bond nature of （H2O）n clusters （n = 3-6） have been investigated by the B3LYP method at the 6-31＋＋g^＊＊ level. Upon calculation, four conclusions have been drawn： （1） In the （H2O）3-5 clusters, cyclic configurations were confirmed to be the most stable. But in the （H2O）3-4 ones, only cyclic configurations could be observed. From n = 5 （（H2O）5 clusters）, three-dimensional configuration could be found： （2） In the （H2O）6 clusters, all configurations are inclined to be three-dimensional except the most stable configuration which is cyclic; （3） The stable order of （H2O）6 clusters indicates that it is the arrangement of hydrogen bond that plays a decisive role in the cluster stabilities, the zero-point energy is also important, and cluster stabilities are independent on the number of hydrogen bonds; （4） There exist strong cooperativity and superadditivity in the （H2O）n clusters.

Corrosion Rate of Hydrogenation to C110 Casing in High H_2S Environment

The corrosion behavior of C110 bushing at high temperature and high pressure with a high H2S / CO2 was studied, and a basis for the materials selection of sour gas well bushing was provided in H2S, CO2 and saline coexisting environment. Under acidic condiction, hydrogen atoms greatly entered into the material and caused the material properties changed. Weight loss method was used to study the corrosion rate of hydrogen charging samples and original untreated samples in simulated oil field environment. PAR2273 electrochemical workstation was used to examine the electrochemical performance of samples untreated, hydrogen charging after reacting in autoclave. The corrosion product film was observed through SEM. The experimental results show that sample with hydrogen charging has a much more obvious partial corrosion and pitting corrosion than the untreated blank sample even the downhole corrosion speed of bushing is increased after being used for a period of time. Polarization curve shows the corrosion tendency is the same between sample with or without hydrogen charging and corrosion tendency is reduced by corrosion product film. A layer of dense product film formed on the surface of samples provides a certain protective effect to the matrix, but cracked holes which will accelerate partial corrosion of the sample were also observed.

Effects of Roudoukou-8 San Extract on Hydrogen Peroxide Induced Cardiomyocyte Injury

[Objectives] To study the effects of Roudoukou-8 San extract on hydrogen peroxide( H_2O_2) induced cardiomyocyte injury of rats and explore its action mechanism. [Methods] The cardiomyocytes of neonatal rats were isolated and cultured,and the H_2O_2 induced cardiomyocyte injury model was established. Methyl thiazolyl tetrazolium( MTT) assay was used to detect the protective effects of Roudoukou-8 San extract on H_2O_2 induced cardiomyocyte. The effects of Roudoukou-8 San on cardiomyocyte morphology were observed under inverted microscope. The contents of lactate dehydrogenase( LDH),creatine kinase( CK) and aspartate aminotransferase( AST) in cell culture medium were determined by automatic biochemical instrument; the levels of malondialdehyde( MDA),superoxide dismutase( SOD) and nitric oxide( NO) in the cells were detected by kit method. The apoptotic morphology of cardiomyocytes was observed by Hoechst fluorescence staining.Cell apoptosis were measured by Annexin V and PI double staining and flow cytometer. [Results]100 μmol/L of H_2O_2 acting 2 h could cause about 50% of cardiomyocyte injury. H_2O_2 model group showed increased cell gap,decreased cell count,cell cytoplasmic vacuoles and other obvious damages. Compared with H_2O_2 model group,in Roudoukou-8 San extract dose groups,cardiomyocyte morphology showed different degrees of improvement,Roudoukou-8 San extract can significantly reduce the content of LDH,CK and AST in H_2O_2 injured myocardial cell culture solution,significantly reduce content of MDA and NO in H_2O_2 injured myocardial cells,increase the SOD activity,and significantly inhibit the apoptosis of H_2O_2 injured myocardial cells. [Conclusions]Through improving the cell survival status,increasing the cell viability,reducing oxidative stress injury,inhibiting inflammatory responses,and inhibiting apoptosis,Roudoukou-8 San extract can improve the state of H_2O_2 induced cardiomyocyte injury,so as to protect H_2O_2 injured myocardial cells.

INVESTIGATION OF HYDROGEN INDUCED DUCTILE BRITTLE TRANSITION IN 7175 ALUMINUM ALLOY

Effects of hydrogen on the mechanical properties of differently aged 7175 aluminum alloys were investigated by using cathodic H-permeation, slow strain rate tension and so on. The results indicate that both the yield stress and the percentage reduction of area decrease with increasing hydrogen charging time, and the degree of reduction decreases as aging time increases for the same hydrogen charging time.

An Extended Cu(Ⅱ) Complex Structure Sustained by Hydrogen Bonding and C-H…π Interactions

The title complex [Cu（L1）（L2）（H2O）]·H2O（1,HL1 = N-（imino（pyridin-2-yl）me-thyl）picolinamidine）,HL2 = salicylic acid） has been obtained by volatilization method with L1 prepared from 2,4,6-tripyridyl-1,3,5-triazine in situ.1 was fully characterized by single-crystal X-ray diffraction,elemental analysis and FT-IR.This complex exhibits a three-dimensional frame-work constructed through hydrogen bonding and C-H···π stacking interactions.The cyclic voltametric behavior of complex 1 was also investigated.1 belongs to the monoclinic system,space group P21/c with a = 15.112（5）,b = 7.115（2）,c = 19.899（6） ,β = 112.32°,V = 1979.4（11） 3,Mr = 460.94,Dc = 1.540 g/cm3,F（000） = 948,μ = 1.146 mm-1,Z = 4,the final R = 0.0612 and wR = 0.1813 for 2510 observed reflections with I 2σ（I）.

Preparation and hydrogen sorption properties of Mg-Cu-Y-H systems

Mg-xwt.%CuY (x=15, 20, 25) composites were successfully prepared by reactive mechanical alloying (RMA). X-ray diffraction (XRD) measurement shows that main phases of the as milled composites are MgH2 and Mg2Cu, and they converted into Mg and MgCu2 after dehydrogenation, respectively. Pressure-Composition-Isotherm (PCI) test shows that the composites exhibit double pressure plateau at each isothermal desorption process. The hydrogen absorption and desorption kinetics of the composites become worse with increasing x content, indicating that Mg-Cu phase has a negative effect on the hydrogen sorption properties of the composites. It is supposed that the good hydrogen sorption properties of the composites attribute to the catalyst effect of yttrium hydride distributed in Mg substrate and the particles size reduction and crystal defects formed by RMA.

C-H…O Hydrogen Bonds and π…π Interaction and the Crystal and Molecular Structures of 3-Nitro-benzylideneaniline-methyl-2’

The title compound (C14H12N2O2, Mr = 240.26) crystallizes in the monoclinic system, space group P21/a with a = 7.394(1), b = 21.334(3), c = 7.423(1) ? b = 89.82(1)? V = 1170.8(3) ?, Z = 4, Dc = 1.363 g/cm3, m(MoKa) = 0.93 cm-1 and F(000) = 504.00. The final R and wR are 0.0440 and 0.1370 for 2153 observed reflections (I > 2s(I)), respectively. The dihedral angle between the two phenyl rings is 52.9 and that between the NO2 group and its attached ring is 3.0. In the crystal, molecules are stacked along [100] through p…p interactions. The CH…O hydrogen bond (3.403 ? 120.4? laterally connects the stacks along [010] to form networks (001) which are further anti- parallelly connected by CH…O (3.382 ? 142.9) and p…p interactions extending along [001]. Also presented here is a brief study on the CH…O hydrogen bonds in nitro-substituted benzyl-ideneanilines which can be classified into five types, namely, )5(12R, )4(21R, )8(22R, )6(12R and )7(22R, with the first three occurring more often.

The Protective Effects of N-Acetylcysteine on Exogenous Hydrogen Peroxide and Endogenous Superoxide Anion-induced DNA Strand Breakage in Human Spermatozoa

Objective To explore the protective effects of N Acetylcysteine (NAC) on exogenous hydrogen peroxide and endogenous superoxide anion induced DNA strand breakage in human spermatozoa by using the single cell gel electropherosis (SCGE) Methods Sperm cells were exposed to 0.5 mmol/L of H 2O 2 or 5.0 mmol/L of β NADPH with or without 0.1, 0.5, 1.0 mmol/L of NAC. The percentage of sperm comet cells and the comet tail lengths were measured in the treated sperm cells by using SCGE. Results Both percentage of comet sperm nuclei and mean tail length in sperm cells exposed to 0.5 mmol/L hydrogen peroxide with different concentrations of NAC decrease significantly in a dose dependent manner as compared with sperm cells exposed to H 2O 2 without NAC or catalase. Although mean tail length in sperm cells exposed to 5.0 mmol/L of β NADPH with different concentrations of NAC decreases significantly compared with sperm cells exposed to β NADPH without NAC or SOD, there were no significant differences on the percentage of sperm comet cells between sperm cells exposed to 5.0 mmol/L of β NADPH with different concentrations of NAC and sperm cells exposed to 5.0 mmol/L of β NADPH without NAC. Conclusion NAC has a protective effect on exogenous hydrogen peroxide induced DNA damage, while protective effect of NAC against O - 2 induced DNA strand breakage is significant but very weak.

Li-Mg-N-H体系储氢材料的研究进展

以Mg(NH_(2))_(2)-2LiH为代表的Li-Mg-N-H体系储氢材料因其储氢容量高、吸放氢可逆、热力学性能较为适宜等优势,被认为是目前最有望实现车载实用化的固态储氢材料之一。该体系的最大问题是吸放氢反应的动力学壁垒较高。综述了Li-Mg-N-H体系主要的成分体系及储氢性能、储氢性能的改善和规模化应用探索等相关研究进展。Li-Mg-N-H体系储氢性能改善的策略主要为材料纳米化和催化改性,其中有效的催化改性剂包括碱金属基化合物(不含硼氢化物)、金属硼氢化物、过渡金属及其化合物、碳材料等。最后,讨论了该体系实现车载实用化需要重点关注的研究方向。

Preparation of hydrogenated microcrystalline silicon films with hot-wire-assisted MWECR-CVD system

Intrinsic hydrogenated microcrystalline silicon （μc-Si：H） films have been prepared by hot-wire-assisted microwave electron-cyclotron-resonance chemical vapour deposition （HW-MWECR-CVD） under different deposition conditions, Fourier-transform infrared spectra and Raman spectra were measured. Optical band gap was determined by Tauc plots, and experiments of photo-induced degradation were performed. It was observed that hydrogen dilution plays a more essential role than substrate temperature in microcrystalline transformation at low temperatures. Crystalline volume fraction and mean grain size in the films increase with the dilution ratio （R=H2/（H2＋SiH4））. With the rise of crystallinity in the films, the optical band gap tends to become narrower while the hydrogen content and photo-induced degradation decrease dramatically. The samples, were identified as μc-Si：H films, by calculating the optical band gap. It is considered that hydrogen dilution has an effect on reducing the crystallization activation energy of the material, which promotes the heterogeneous solid-state phase transition characterized by the Johnson-Mehl-Avrami （JMA） equation. The films with the needed structure can be prepared by balancing deposition and crystallization through controlling process parameters.