Exploring the Cation Regulation Mechanism for Interfacial Water Involved in the Hydrogen Evolution Reaction by In Situ Raman Spectroscopy

Interfacial water molecules are the most important participants in the hydrogen evolution reaction(HER).Hence,understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism.Unfortunately,investigating interfacial water is extremely challenging owing to the interference caused by bulk water molecules and complexity of the interfacial environment.Here,the behaviors of interfacial water in different cationic electrolytes on Pd surfaces were investigated by the electrochemistry,in situ core-shell nanostructure enhanced Raman spectroscopy and theoretical simulation techniques.Direct spectral evidence reveals a red shift in the frequency and a decrease in the intensity of interfacial water as the potential is shifted in the positively direction.When comparing the different cation electrolyte systems at a given potential,the frequency of the interfacial water peak increases in the specified order:Li+<Na^(+)<K^(+)<Ca^(2+)<Sr^(2+).The structure of interfacial water was optimized by adjusting the radius,valence,and concentration of cation to form the two-H down structure.This unique interfacial water structure will improve the charge transfer efficiency between the water and electrode further enhancing the HER performance.Therefore,local cation tuning strategies can be used to improve the HER performance by optimizing the interfacial water structure.

Genesis of underground brine along south coast of Laizhou Bay:hydrochemical characteristics

Hydrochemistry of underground brines along south coast of Laizhou Bay, Shandong, China has been analyzed. Brine samples were collected from 43 wells in this area. It was considered that the brines were originated from seawater. However, whether they were formed by seawater evaporation or seawater freezing was not fully sure. We created a simple method by plotting Na/Cl vs. seawater concen-tration factor (SCF) and Ca/Mg vs. SCF to determine the brine formation geochemically. Comparison of our results to previous seawater freezing and evaporation experiments indicated that the brines were formed by seawater evaporation. The ratios of HCO3/Cl of some low salinity brines in the study area were relatively higher, indicating that the brines may have mixed with other waters after the generation. The Br/Cl ratios of the brines decreased annually in the past 20 to 30 years of exploitation, indicating down-ward permeation of the brine from which bromine was extracted.

Preparation of Ultrafine Cobalt Powder by Chemical Reduction in Aqueous Solution

Nanocrystalline cobalt powders have been prepared from aqueous solution by reducing their corresponding metal salts under suitable conditions. The experimental conditions have been studied in detail. X-ray powder diffraction patterns show that the cobalt powder is hexagonal crystallite. The average particle size of the ultrafine cobalt powder is 55 nm.

Application of Bandura's Social Learning Theory in the Moral Education of Secondary Vocational College Students

In recent years,with the high rate of juvenile delinquency,people pay more attention to the moral education of students in secondary vocational colleges.Based on the framework of social learning theory,this paper explores the systematic and comprehensive application of social learning theory in the moral education course.From the cognition of the behavior to the selection and internalization of the representation of the model behavior,and finally the selective extemalization of the representation symbol to generate the behavior,the influencing factors and their utility in each stage of the production of moral behavior are analyzed step by step,assisting students to establish correct outlook on life and values,and cultivating their"key abilities."When students face a complex and diverse social environment,they can make judgments in line with the general moral standards of the society,and then seek to improve the effectiveness of the moral standards of secondary vocational students,and strive to maximize the effectiveness of moral education.

Pea-like MoS_(2)@NiS_(1.03)-carbon heterostructured hollow nanofibers for high-performance sodium storage

The rational synergy of chemical composition and spatial nanostructures of electrode materials play important roles in high-performance energy storage devices.Here,we designed pea-like MoS_(2)@NiS_(1.03)-carbon hollow nanofibers using a simple electrospinning and thermal treatment method.The hierarchical hollow nanofiber is composed of a nitrogen-doped carbon-coated NiS_(1.03) tube wall,in which pea-like uniformly discrete MoS_(2) nanoparticles are enclosed.As a sodium-ion battery electrode material,the MoS_(2)@NiS_(1.03)-carbon hollow nanofibers have abundant diphasic heterointerfaces,a conductive network,and appropriate volume variation-buffering spaces,which can facilitate ion diffusion kinetics,shorten the diffusion path of electrons/ion,and buffer volume expansion during Na^(+)insertion/extraction.It shows outstanding rate capacity and long-cycle performance in a sodium-ion battery.This heterogeneous hollow nanoarchitectures designing enlightens an efficacious strategy to boost the capacity and long-life stability of sodium storage performance of electrode materials.

Constructing a hollow core-shell structure of RuO_(2) wrapped by hierarchical porous carbon shell with Ru NPs loading for supercapacitor

Hollow core-shell structure nanomaterials have been broadly used in energy storage, catalysis, reactor,and other fields due to their unique characteristics, including the synergy between different materials,a large specific surface area, small density, large charge carrying capacity and so on. However, their synthesis processes were mostly complicated, and few researches reported one-step encapsulation of different valence states of precious metals in carbon-based materials. Hence, a novel hollow core-shell nanostructure electrode material, RuO_(2)@Ru/HCs, with a lower mass of ruthenium to reduce costs was constructed by one-step hydrothermal method with hard template and co-assembled strategy, consisting of RuO_(2) core and ruthenium nanoparticles(Ru NPs) in carbon shell. The Ru NPs were uniformly assembled in the carbon layer, which not only improved the electronic conductivity but also provided more active centers to enhance the pseudocapacitance. The RuO_(2) core further enhanced the material’s energy storage capacity. Excellent capacitance storage(318.5 F·g^(-1)at 0.5 A·g^(-1)), rate performance(64.4%) from 0.5 A·g^(-1)to 20 A·g^(-1), and cycling stability(92.3% retention after 5000 cycles) were obtained by adjusting Ru loading to 0.92%(mass). It could be attributed to the wider pore size distribution in the micropores which increased the transfer of electrons and protons. The symmetrical supercapacitor device based on RuO_(2)@Ru/HCs could successfully light up the LED lamp. Therefore, our work verified that interfacial modification of RuO_(2) and carbon could bring attractive insights into energy density for nextgeneration supercapacitors.

Co@CoO:An efficient catalyst for the depolymerization and upgrading of lignocellulose to alkylcyclohexanols with cellulose intact

The depolymerization and upgrading of lignin from raw biomass,while keeping cellulose intact is important in biorefinery and various metal-based catalysts have been used in reductive catalytic fractionation,a key method in"lignin-first"strategy,Recently,we found that a core-shell structured Co@CoO catalyst with CoO shell as the real active site had excellent performance in the hydrogenolysis of 5-hydromethylfurfural to 2,5-dimethylfuran due to its unique ability to dissociate H_(2)and yield active H^(δ-)species(Xiang et al.,2022).In this work,we report a one-pot depolymerization and upgrading of lignocellulose to alkylcyclohexanols,a flavour precursor,with intact cellulose over this unique core-shell structured catalyst,Co@CoO.Lignin model compounds(β-O-4,4-O-5,α-O-4)were first used to clarify the activity of Co@CoO catalyst.Then,the one-pot conversion of various organosolv lignin(birch,pine and poplar)to alkylcyclohexanols was realized with the mass yield of alkylcyclohexanols up to25.8 wt%from birch lignin under the reaction condition of 210℃,1 MPa H_(2),16 h.Finally,the corresponding woody sawdusts were used as feedstocks and found that the Co@CoO catalyst indeed preferentially depolymerized and upgraded the lignin part and obtained the same alkylcyclohexanols products with the retention of cellulose-rich pulp.The collected alkylcyclohexanols were further esterified to obtain valueadded esters,which can be used as flavors.This work will inspire the design of new efficient metal oxide catalysts in lignin fractionation and depolymerization to high-value-added chemicals with intact cellulose.

Studies on synthesis and fluorescent property of rare earth complexes RE(ABMF)_2AA and copolymers RE(ABMF)_2AA-co-MMA

Four new complexes RE(ABMF)2AA(RE=Sm, Eu, Tb, Dy) were synthesized by the reaction of RECl3·6H2O with acrylic acid(HAA) and 1-(2-furyl)-3-phenyl-1,3-propanedione(ABMF).The copolymerization of the rare earth complexes with methyl methacrylate was studied by using 2,2-azobis-isobutyronitrile as an initiator.The composition and structure of the four complexes were characterized by elemental analysis, UV-vis and FTIR.The glass transition temperature and molecular weight of the copolymers were determined.Photolu-minescent measurement showed that ligand ABMF could efficiently transfer the energy to Sm3+ and Eu3+ ions in the complexes and sensitize the luminescence of the rare earth ions, but could not sensitize Tb3+ and Dy3+ ions.As a result, both Sm3+ and Eu3+ complexes emitted the characteristic fluorescence of Sm3+ and Eu3+ ions due to the f-f transitions.The four copolymers could emit strong fluorescence of the rare earth ions.

Synthesis,Crystal Structure and Fluorescence Property of the Ag(Ⅰ) Coordination Polymer Constructed by 2D[Ag(1,3-BIP)(PMA)_(0.5)]_n^(n-)Layers and 1D[Ag(1,3-BIP)(H_2O)]_n^(n+) Chains

A new Ag(I) coordination polymer,{[Ag(l,3-BIP)(H_2O)][Ag(l,3- BIP)(PMA)_(0.5)·-4H_2O}_n(PMA = 1,2,4,5-benzenetricarboxylic acid,1,3-BIP = l,3-bis(imidazole)propane),have been synthesized and characterized by single-crystal X-ray diffraction,powder XRD,FTIR,TGA and elemental analysis techniques.The single-crystal X-ray diffraction reveals that the title complex is formed by 1D polymeric cationic chains of[Ag(l,3-BIP)(H_2O)]_n^(n+) and 2D polymetric anionic layer of[Ag(l,3-BIP)(PMA)_(0.5]_n^(n-),which are further linked by intermolecular H-bonding to form a3 D supramolecular framework.In addition,the photoluminescence property of the title complex in the solid state at room temperature was also investigated.

Synthesis, Structure and Luminescent Property of a 2D Cd(Ⅱ) Coordination Polymer Based on Mixed-ligands of 1,3-Bis(imidazol)propane and Pyridine-3,5-dicarboxylic Acid

A new Cd(Ⅱ) coordination polymer, namely, [Cd(1,3-bip)(3,5-pdc)]n(1,3-bip =1,3-bis(imidazol)propane and 3,5-pdc = pyridine-3,5-dicarboxylic acid) has been synthesized under hydrothermal conditions. Compound 1 was characterized by infrared spectrum, elemental analysis,powder X-ray diffraction(PXRD) and single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/c with a = 1.40178(7), b = 1.72502(12), c = 1.41635(6) nm, β =92.653(4)o, V = 3.4212(3) nm3, Z = 4, C316H15 Cd N5O4, Mr = 453.73, Dc = 1.762 g/cm, F(000) =1808, μ = 1.310 mm-1, R = 0.0899 and w R = 0.1945. In compound 1, each 3,5-pdc ligand links three Cd(Ⅱ) ions and each Cd(Ⅱ) attaches to bip ligands to form a complicated 2D double-layer structure. In addition, the thermal stability and luminescent property of 1 have been studied in the solid state at room temperature.

Tungstophosphoric heteropolyacid supported onto neutral alumina: characterization and synthesis of acetals and ketals

Tungstophosphoric acid (HPW) catalyst supported on the neural alumina was studied. It was prepared by means of an equilibrium and incipient wetness impregnation technique. Solution of HPW in 50% V/V ethanol-water was used to impregnate Al2O3 at 25°C. It was found that the catalyst containing 30% PW by calcination at 500°C showed a higher catalytic activity in the synthesis of acetals and/or ketals. In the following condition, that is, the molar ratio of aldehyde/ketone to glycol being 1:1.5,the mass fraction of the catalyst used was 0.5%, and the reaction time was 1.0 h; the yields of ketals and acetals could reach up to 60.5%-86.7%. Moreover, it could be easily recovered and reused.

Synthesis, Crystal Structure and Luminescent Property of a Ag(Ⅰ) Coordination Polymer with a 3D Sandwich-like Framework

A new coordination polymer,{[Ag_2(bpp)_2(H_2O)_2]·bpdc·3H_2O}_n,derived from the ligand biphenyl-4,4'-dicarboxylic acid(H_2bpdc),has been obtained through a hydrothermal technique(bpp = l,3-bis(4-pyridyl)propane).Its single-crystal structure has been characterized by single-crystal X-ray diffraction,powder XRD,FT-IR,TGA and elemental analysis techniques.The single-crystal X-ray diffraction reveals that complex 1 consists of 1D infinite[Ag(bpp)(H_2O)]_n^(n+)cationic chains,2D anionic layer constructed by bpdc anions and free water which provide charge compensation in the crystal structure.The 1D infinite[Ag(bpp)(H_2O)]_n^(n+) cationic chains and 2D anionic layer are further stacked in-ABAB- fashion through intermolecular H-bonding to form a 3D sandwich-like framework.In addition,the luminescent property of complex 1 in the solid state at room temperature was investigated.

Tribological Properties of Magnesium Ion-exchanged α-Zirconium Phosphate as a Solid Lubricant Additive in Lithium Grease

Magnesium ion-exchanged a-zirconium phosphates(Mg-α-ZrP) with particle sizes of 600 and 80 nm were prepared through the sealed ion-exchange and one-step hydrothermal synthesis methods, respectively. It was found that larger particles of Mg-α-ZrP had a higher load-carrying capacity than that of smaller particles, whereas smaller Mg-α-ZrP particles had better anti-wear properties than that of larger Mg-α-ZrP particles under mild loads. The correlation between the particle size of the sample and the surface roughness of the friction pair thus seems to be a key factor influencing the performance.

CORROSION BEHAVIOR OF A ZIRCONIUM-TITANIUM BASED PHOSPHONIC ACID CONVERSION COATING ON AA6061 ALUMINIUM ALLOY

变换涂层被在 fluorotitanate/zirconate 酸和氨基的 trimethylene 蘸 AA6061 形成在房间温度的磷的酸(ATMP ) 答案。形成进程和变换涂层的耐蚀性能分别地用电气化学的测试和盐水花测试(SST ) 被调查。电气化学的测试证明 Zr/Ti 和 ATMP 涂层像铬酸盐一样改进 AA6061 的腐蚀抵抗() SST 的结果显示出的 coating.But Zr/Ti 和 ATMP 涂层的腐蚀抵抗不像铬酸盐一样() coating.The 腐蚀区域在 72 以后是不到2%h 。

Speciation of heavy metals in airborne particles,road dusts,and soils along expressways in China

This study analyzed the concentrations and chemical forms of Zn,Cu,Pb,Sb,Cd and Mn in airborne particles,road dusts and soils collected along three expressways in Jiangxi Province,China,with different traffic densities,and identified the levels and sources of heavy metal contamination.The concentrations of Zn,Cu,Pb,Sb,and Cd except Mn in airborne particles,road dusts and soils were all in direct proportion to traffic volume.Cd concentrations were low compared with other metals.For instance,the concentrations of Zn,Cu,Pb,Sb,Mn and Cd were 6.6,0.7,2.2,0.1,0.1 and 0.1μg·m-3in PM10along the Changjiu Expressway,792.8,241.4,248.3,9.6,340.5and 8.0 mg·kg-1in road dusts,and 201.1,143.2,59.5,9.5,338.9 and 2.3 mg·kg-1in soils,respectively,but in the case of the ratio of concentration to the environmental background value,most serious contamination was caused by Cd.The sources of the heavy metals were judged by comparisons of the chemical forms of the heavy metals in different environmental media.Pb and Mn in airborne particles were both derived from traffic;Pb in road dusts and soils resulted mainly from the use of leaded gasoline in the past;and Mn in road dusts and soils was derived from parent rocks.Zn,Cu,Sb and Cd in airborne particles,road dusts and soils were derived primarily from traffic,and differences in chemical forms of the heavy metals in different media were due to the interaction between heavy metals in airborne particles and organic matter and other surfaces in road dusts and soils.We also discussed the change of chemical forms of heavy metals in particles of different sizes and under different weather conditions.Bioavailability of heavy metals in airborne particles was much higher than that in road dusts and soils,especially Pb(0.676 in airborne particles,0.159 in road dusts and 0.095 in soils).

CORROSION RESISTANCE OF HOT DIP GALVANIZED STEEL PRETREATED WITH BIS-FUNCTIONAL SILANES MODIFIED WITH NANOALUMINA

热剧降的腐蚀行为电镀了有二度的钢 pretreated --[ triethoxy-silylpropyl ]与氧化铝粒子修改的 tetrasulfide ( BTESPT )是 passiving 电影的 studied.The 腐蚀电阻被 Tafel 极化曲线和在电镀的钢底层上形成的电气化学的阻抗 spectroscopy.The 电影评估被 Fourier 变换描绘红外线的光谱学并且精力对待的热剧降的散X光检查 spectrometry.The 表面形态学电镀了钢预告的处理与 nanoalumina 粒子根据 silane 电影修改了的结果表演减少了阳极并且 cathodic 水流密度，和在测量频率的增加的全部的阻抗，因而为电镀的钢在在与铬酸盐电影和 silane 相比的 NaCl 答案的沉浸期间拍摄的热剧降改进腐蚀保护。

Determination of the Toxicities of 16 Halogenated Benzenes to Photobacterium Phosphoreum and 2D- and 3D-QSAR Studies

In this paper we take photobacterium phosphoreum(T_3)as the experimental bacteria, and determine the half-inhibitory concentration(-lgEC_(50))against the photobacterium phosphoreum of 16 halogenated benzenes.Using B3LYP method of DFT in the Gaussian 03 program,we obtain the structural and thermodynamic descriptors of 16 halogenated benzenes by fully-optimized calculation at the 6-311G** level.Taking the structural and thermodynamic descriptors as theoretical descriptors,the 2D QSAR model(R^2=0.983)was established,which can be utilized to predict-1gEC_(50)of halogenated benzene according to the corrected linear solvation energy theory based on the experimental data of-1gEC_(50).In addition,the relationship between the toxicity and 3D spatial structure of the compound is studied by comparing the molecular similarity index analysis (CoMSIA)of 3D-QSAR method.By cross validation,the correlation coefficient q^2 of CoMSIA model is 0.687,and the conventional correlation coefficient R^2=0.958.The model is stable and reliable with great predictive ability.The 3D-QSAR model shows that the toxicity of halogenated benzene compound is mainly affected by the characteristics of hydrophobic field of the substituted halogens.

Phase Equilibrium of Isobutanol in Supercritical CO2

Vapor-liquid phase equilibrium data including composition,densities,molar volume and equilibrium constant of isobutanol in supercritical carbon dioxide from 313.2K to 353.2K were measured in a variable-volume visual cell.The properties of critical point were obtained by extrapolation.The results showed that critical temperature,critical pressure and critical compressibility factor of CO2-isobutanol system decreased with the increase of critical CO2 content.The phase equilibrium model was established by Peng-Robinson equation of state and van der Waals-2 mixing regulation,and model parameters were determined by optimization calculation of nonlinear least square method.The correlation between calculated values and the experimental data showed good agreement.

Zn–Ca–Al mixed oxide as efficient catalyst for synthesis of propylene carbonate from urea and 1,2-propylene glycol

A series of Zn–Ca–Al oxides with different CaO and ZnO contents have been prepared and evaluated in the synthesis of propylene carbonate(PC) from 1,2-propylene glycol(PG) and urea in a batch reactor. The effect of catalyst composition, basicity and reaction process parameters such as temperature, catalyst dose, molar ratio of PG to urea, purge gas flow and reaction time has been studied to find suitable reaction conditions for the PC synthesis. The PC selectivity and yield under the desired conditions could reach 98.4% and 90.8%, respectively. The best performing catalyst also exhibited a good reusability without appreciable loss in the PC selectivity and yield after five consecutive reaction runs. In addition, a stepwise reaction pathway involving a 2-hydroxypropyl carbamate intermediate was proposed for the urea alcoholysis to PC in the presence of Zn–Ca–Al catalysts, according to the time dependences of reaction intermediates and products.

A novel spectrophotometric determination of copper(Ⅱ) with bromosulphonazoⅢ

A novel chromogenic reaction involving copper(Ⅱ)and bromosulphonazoⅢ(Br-SAZⅢ)in hexamethylenetetramine- hydrochloric buffer solution was investigated.The results showed that a blue complex of copper(Ⅱ)and bromosulphonazoⅢwas formed with a molar ratio of 1:1.The apparent molar absorptivity was 3.3×10~5L mol^(-1)cm^(-1)and the maximum absorption peak was at 616.8 nm.The proposed procedure was used for quantitative estimation of Cu(Ⅱ)in the concentration range of 0-1.024μg/mL with the detection limit(3σ)of 7.03×10^(-4)μg/mL(n=20).The relative standard deviations(RSDs)were 0.56-4.68%.Under the optimized conditions,total copper in the vegetables and tea was successfully determined.