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Cubic Mesoporous Aluminosilicate with Primary Structure Units of Zeolite Beta in the Pore Wall
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作者 Gong LI Qiu Bin KAN +1 位作者 Tong Hao WU Jia Hui HUANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第6期637-640,共4页
Mesoporous aluminosilicate with cubic ordered structure was synthesized by two-step crystallization, which showed stronger acid sites and more effective activity for catalytic alkylation of 2, 4-ditert-butylphenol wit... Mesoporous aluminosilicate with cubic ordered structure was synthesized by two-step crystallization, which showed stronger acid sites and more effective activity for catalytic alkylation of 2, 4-ditert-butylphenol with tert-butanol than conventional H-AlMCM-48 materials. 展开更多
关键词 Cubic mesostructure two-step crystallization primary structure units zeolite beta catalysis.
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Investigation of the Interaction Mechanism between Lignin Structural Units and Enzyme
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作者 Lijing Huang Penghui Li +1 位作者 Kangjie Jiang Wenjuan Wu 《Journal of Renewable Materials》 SCIE EI 2023年第4期1613-1626,共14页
The effect of lignin structural units on enzymatic hydrolysis of lignocellulosic biomass was investigated,especially the inhibitory role of lignin in non-productive adsorption with enzymes.Milled wood lignin(MWL)was i... The effect of lignin structural units on enzymatic hydrolysis of lignocellulosic biomass was investigated,especially the inhibitory role of lignin in non-productive adsorption with enzymes.Milled wood lignin(MWL)was isolated from different hardwoods of poplar,eucalyptus and acacia.The isolated lignin samples were characterized by elemental analysis,gel permeation chromatography,nitrobenzene oxidation and fourier infrared spectroscopy.The mechanism of lignin structural units on enzymatic hydrolysis of cellulose was studied by quartz crystal microbalance(QCM).The results showed that different structural units of lignin had different adsorption capacity for enzymes.The results of nitrobenzene oxidation indicated that the S/G ratio(S:syringyl-like lignin structures;G:guaiacyl-like lignin structures)of lignin of poplar was 0.99,that of eucalyptus was 1.92 and that of acacia was 1.34.According to the results of QCM,the adsorption capacity of the three lignin films was as follows:Poplar MWL(S/G ratio 0.99)<Acacia MWL(S/G ratio 1.34)<Eucalyptus MWL(S/G ratio 1.92).Eucalyptus MWL with higher degree of condensation and S/G ratio showed stronger affinity to enzymes and more non-productive adsorption with enzymes,resulting in less adsorption between enzymes and cellulose,and lower enzymatic hydrolysis efficiency. 展开更多
关键词 LIGNIN structural unit enzyme adsorption enzymatic hydrolysis
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Layered oxide cathodes for sodium-ion batteries:microstructure design,local chemistry and structural unit
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作者 Ling-Yi Kong Han-Xiao Liu +10 位作者 Yan-Fang Zhu Jia-Yang Li Yu Su Hong-Wei Li Hai-Yan Hu Yi-Feng Liu Ming-Jing Yang Zhuang-Chun Jian Xin-Bei Jia Shu-Lei Chou Yao Xiao 《Science China Chemistry》 SCIE EI CSCD 2024年第1期191-213,共23页
Because of the low price and abundant reserves of sodium compared with lithium,the research of sodium-ion batteries(SIBs)in the field of large-scale energy storage has returned to the research spotlight.Layered oxides... Because of the low price and abundant reserves of sodium compared with lithium,the research of sodium-ion batteries(SIBs)in the field of large-scale energy storage has returned to the research spotlight.Layered oxides distinguish themselves from the mains cathode materials of SIBs owing to their advantages such as high specific capacity,simple synthesis route,and environmental benignity.However,the commercial development of the layered oxides is limited by sluggish kinetics,complex phase transition and poor air stability.Based on the research ideas from macro-to micro-scale,this review systematically summarizes the current optimization strategies of sodium-ion layered oxide cathodes(SLOC)from different dimensions:microstructure design,local chemistry regulation and structural unit construction.In the dimension of microstructure design,the various structures such as the microspheres,nanoplates,nanowires and exposed active facets are prepared to improve the slow kinetics and electrochemical performance.Besides,from the view of local chemistry regulation by chemical element substitution,the intrinsic electron/ion properties of SLOC have been enhanced to strengthen the structural stability.Furthermore,the optimization idea of endeavors to regulate the physical and chemical properties of cathode materials essentially is put forward from the dimension of structural unit construction.The opinions and strategies proposed in this review will provide some inspirations for the design of new SLOC in the future. 展开更多
关键词 sodium-ion batteries layered oxide cathodes microstructure design local chemistry structural unit
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Coalfield structure and structural controls on coal in China 被引量:2
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作者 Daiyong Cao Anmin Wang +6 位作者 Shuzheng Ning Huantong Li Aijun Guo Limin Chen Kang Liu Jieqing Tan Zhihong Zheng 《International Journal of Coal Science & Technology》 EI 2020年第2期220-239,共20页
The occurrence of coal-bearing strata in a variety of coal-bearing basins of China is characterized by late tectonic deformation and remarkable spatial and geochronologic differences.The main controlling factors,which... The occurrence of coal-bearing strata in a variety of coal-bearing basins of China is characterized by late tectonic deformation and remarkable spatial and geochronologic differences.The main controlling factors,which determine the tectonic framework of coalfields,include the geodynamic environment,tectonic evolution,deep structures,tectonic stress,and lithologic combination of the coal measures.The Chinese continent has experienced multi-stage tectonic movements since the Late Paleozoic.The spatial and temporal heterogeneity of its continental tectonic evolution,the complexity of its basement properties,and its stratigraphic configurations control the tectonic framework of its coalfields’present complex and orderly patterns.The concept of coal occurrence structural units is proposed in this paper and is defined as the structural zoning of coal occurrence.China’s coalfields are divided into five coal occurrence structural areas,and the structural characteristics of the coalfields in five main coal occurrence areas throughout the country are summarized.Based on the analysis of the relationship between the structure characteristics and occurrence of coal in these coalfields,the coal-controlling structures are divided into six groups:extensional structural styles,compressional structural styles,shearing and rotational structural styles,inverted structural styles,sliding structural styles,and syn-depositional structural styles.In addition,the distribution of coal-controlling structural styles is briefly summarized in this paper. 展开更多
关键词 Coalfield structures Coal-controlling structures Coal occurrence structural units Types of coal-bearing basins Coal-controlling structural styles
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A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO_4-H_2O and NaF-H_2O binary solutions and NaClO_4-NaF-H_2O ternary solution 被引量:1
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作者 Xue-min Yang Wei-jie Zhao +2 位作者 Han-jie Guo Qiang Zhang Jian Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2010年第5期546-557,共12页
A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions and NaClO4-NaF-H2O ternary strong electrolyte aqueous solutions was develo... A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions and NaClO4-NaF-H2O ternary strong electrolyte aqueous solutions was developed based on the ion and molecule coexistence theory (IMCT). A transformation coefficient was needed to compare the calculated mass action concentration and the reported activity, because they were usually obtained at different standard states and concentration units. The results show that transformation coefficients between the calculated mass action concentrations and the reported activities of the same components change in a very narrow range. The transformed mass action concentrations of structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions agree well with the reported activities. The transformed mass action concentrations of structural units or ion couples in NaClO4-NaF-H2O ternary solution are also in good agreement with the reported activities in a total ionic strength range from 0.1 to 0.9 mol/kg H2O by the 0.1 mol/kg step with different ionic strength fractions of 0, 0.2, 0.4, 0.5, 0.6, 0.8, and 1, respectively. The results indicate that the developed thermodynamic model can reveal the structural characteristics of binary and ternary strong electrolyte aqueous solutions, and the calculated mass action concentrations of structural units or ion couples also strictly follow the mass action law. 展开更多
关键词 binary systems ternary systems thermodynamic model activity coefficient structural unit
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Synthesis,Crystal Structure and Fluorescent Properties of a Cadmium(Ⅱ) Complex with 3-(Pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole 被引量:3
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作者 王玉芳 孙小媛 耿俊磊 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第3期397-403,共7页
Compound [Cd_(1.5)(ppt)Br_2(H_2O)]_(2n)(1),where Hppt = 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole,has been synthesized under hydrothermal conditions and characterized by elemental analysis,IR s... Compound [Cd_(1.5)(ppt)Br_2(H_2O)]_(2n)(1),where Hppt = 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole,has been synthesized under hydrothermal conditions and characterized by elemental analysis,IR spectra,powder XRD,and X-ray diffraction.Compound 1 crystallizes in the triclinic system,space group P1 with a = 7.4402(6),b = 8.0570(7),c = 12.8674(11) A,α = 89.7300(10),β = 89.8570(10),γ = 68.3910(10)°,V = 717.13(10) A^3,Z = 1,Dc = 2.638 g/cm^3,μ = 7.824 mm^-1,F(000) = 534,the final R = 0.0324 and w R = 0.1084 for 2324 observed reflections with I 〉 2σ(I).X-ray diffraction analyses revealed that complex 1 is a 2D layered coordination polymer constructed from the linkage of [Cd_3(μ-Br)_4] trinuclear units with ppt-spacers,and a 3D supramolecular architecture is further assembled in 1 via hydrogen-bonding contacts.Fluorescence measurements show that 1 has medium fluorescent emission at 450 nm. 展开更多
关键词 trinuclear unit crystal structure fluorescent
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Effect of Structural Units on the Adhesion of Acrylic Copolymers to Fibers for Warp Sizing 被引量:1
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作者 祝志峰 许德生 徐珍珍 《Journal of Donghua University(English Edition)》 EI CAS 2010年第6期825-829,共5页
Radical copolymerization of acrylic acid(AA)with acrylamide(AM)or acrylamide/acrylonitrile(AM/AN)was initiated with ammonium persulfate as initiator to produce acrylic copolymers such as bicopolymer poly(AM-co-AA)and ... Radical copolymerization of acrylic acid(AA)with acrylamide(AM)or acrylamide/acrylonitrile(AM/AN)was initiated with ammonium persulfate as initiator to produce acrylic copolymers such as bicopolymer poly(AM-co-AA)and tercopolymer poly(AM-co-AN-co-AA)for revealing the effects of the structural units of the copolymers on the adhesion of the copolymers to polyester or cotton fibers for warp sizing.The adhesion was evaluated in terms of tensile strength and work-to-break of a roving impregnated with the copolymer solution.It was found that the adhesion strongly depended on type and amount of the units incorporated into the copolymeric chains.Whether the fiber is cotton or polyester,the adhesion of the bicopolymer poly(AM-co-AA)is greater than that of polyacrylic acid or polyacyamide.Excessively increasing the amount of AM or AA unit in poly(AM-co-AA)lowers the adhesion.To enhance the adhesion of the bicopolymer,a favorable mole ratio of AM to AA is 70/30.Based on this mole ratio,incorporation of acrylonitrile units into poly(AM-co-AA)to form tercopolymer enhances the adhesion. 展开更多
关键词 acrylic copolymers warp sizes structural units ADHESION
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SYNTHESIS AND CHARACTERIZATION OF AROMATIC LIQUID CRYSTALLINE COPOLYESTERS WITH REGULAR SEQUENCE STRUCTURE
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作者 林庆煌 王慧芬 +1 位作者 刘德山 周其庠 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1990年第3期240-246,共7页
Several novel aromatic liquid crystalline copolyesters with regular sequence structure were prepared by melt Sehotten-Baumann polycondensation via complex monomer. Polarizing microscope with hot stage, thermal analysi... Several novel aromatic liquid crystalline copolyesters with regular sequence structure were prepared by melt Sehotten-Baumann polycondensation via complex monomer. Polarizing microscope with hot stage, thermal analysis and X-ray diffraction were used to investigate the structure and properties of the copolyesters. The effects of structural units, such as flexible spacer, noncolinear meta-linked phenylene unit, crankshaft unit, kink with flexible bridging unit and various substituted benzene rings on melting temperature of aromatic copolyesters were studied and discussed on the basis of crystalline structure of the polymers. 展开更多
关键词 Aromatic copolyester Thermotropic liquid crystal Melting temperature Structural unit
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STUDY ON MAXIMUM HYDROGEN CAPACITY FOR Zr-Ni AMORPHOUS ALLOY
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作者 张东明 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2000年第4期28-32,共5页
To design the amorphous hydrogen storage alloy efficiently, the maximum hydrogen capacities for Zr - Ni amorphous alloy were calculated. Based on the Rhomb Unit Structure Model(RUSM) for amorphous alloy and the experi... To design the amorphous hydrogen storage alloy efficiently, the maximum hydrogen capacities for Zr - Ni amorphous alloy were calculated. Based on the Rhomb Unit Structure Model(RUSM) for amorphous alloy and the experimental result that hydrogen atoms exist in 3Zr1Ni and 4Zr tetrahedron interstices in Zr-Ni amolphous alloy, the numbers of 3Zr-1Ni and 4Zr tetrahedron interstices in a RUSM were calculated which correspond to the hydrogen capacity. The two extremum Zr distribution states were calculated, such as highly heterogeneous Zr distribution and homogeneous Zr distribution. The calculated curves of hydrogen capacity with different Zr contents at two states indicate that the hydrogen capacity increases with increasing Zr content and reaches its maximum when Zr is 75%. The theoretical maximum hydrogen capacity for Zr - Ni amorphous alloy is 2.0 (H/M). Meanwhile, the hydrogen capacity of heterogenous Zr distribution alloy is higher than that of homogenous one at the same Zr content. The experimental results prove the calculated results reasonable, and accordingly, the experimental results that the distribution of Zr atom in amorphous alloy occur heterogeneous after a few hydrogen absorption desorption cycles can be explained. 展开更多
关键词 Rhomb unit structure Model (RUSM) 3Zr1Ni or 4Zr tetrahedron interstice maximum hydrogen capacity
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CRYSTALLOGRAPHIC PROPERTIES OF AN INHERENT LOW-ENERGY INTERFACE(1■1)Cu//(0001)_(AIN)IN Cu-AlN BICRYS
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作者 J. Du,G.Y.Yang and S. Hagegege(General Research Institute for Non-ferrous Metals, Beijing 100088, China)(CECM-CNRS,15 rue G. Urbain, 94407 Vitry/Seine, France ) 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1996年第4期235-239,共5页
A model Cu-AlN composite has been prepared by ion implantation technique and annealing. The atomic configuration and lattice relationship of a low-energy inherent interface(11)Cn//(0001)AlN were studied by using trans... A model Cu-AlN composite has been prepared by ion implantation technique and annealing. The atomic configuration and lattice relationship of a low-energy inherent interface(11)Cn//(0001)AlN were studied by using transmission electron microscopy and geometrical modelling. By analysing the dichromatic pattern of the composite,a primary structural unit of the interface atomic configuration was determined for purpose of HREM image simulations and of studying the structurul relaxation state in the near-interface region. 展开更多
关键词 Cu-AlN inherent interface SYMMETRY structural unit
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The Power Structure of Rural Grassroots Units and Its Operational Mechanisms: A Case Study of the Situation in Changwuzhen in Heilongjiang Province
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作者 王雅林 Huang Shiqi Su Xuetao 《Social Sciences in China》 2000年第2期5-23,共19页
关键词 The Power structure of Rural Grassroots units and Its Operational Mechanisms A Case Study of the Situation in Changwuzhen in Heilongjiang Province
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The Study-to-work Transition of Chinese International Students:Navigating a Future in the Global Labour Market
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作者 Manli Xu Meng Zhan 《教育技术与创新》 2022年第2期22-39,共18页
In the global competition for talents,the massive inflow of Chinese students into the UK has drawn great attention.However,only a few studies examine students’interactions with socioeconomic structures in their study... In the global competition for talents,the massive inflow of Chinese students into the UK has drawn great attention.However,only a few studies examine students’interactions with socioeconomic structures in their study-to-work transition.This study used Higher Education Statistics Agency􀀋HESA,2􀀓2􀀔􀀌data and interview data collected from Chinese postgraduate students,and it aims to:investigate structural factors that influence post-study migration patterns of Chinese students;and explore how Chinese students interact with wider social structures.This study found that different configurations between students􀀊"goals,""actions,"and"reflexivity"would lead to different employment outcomes.Three different study-to-work transition strategies were identified:"proceeding without a fixed plan";"reaching a compromise";and"knowing goals and approaching goals".Findings suggest that the transition between study and work is more complex than what is described in human capital and push-pull approaches.A better understanding of students’decision-making processes would help higher education institutions in preparing graduates for careers in the global labour market. 展开更多
关键词 Chinese international students study-to-work transition labour market structuration theory the united Kingdom(UK)
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Energy conservation in China's coal-fired power industry by installing advanced units and organized phasing out backward production 被引量:1
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作者 Weiliang WANG Junfu LYU +3 位作者 Zheng LI Hai ZHANG Guangxi YUE Weidou NI 《Frontiers in Energy》 SCIE CSCD 2019年第4期798-807,共10页
Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China.It is generally believed that advanced technology should be counted on for energy conse... Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China.It is generally believed that advanced technology should be counted on for energy conservation.However,a review of the decline in the national average net coal consumption rate(NCCR)of China's coal-fired power industry along with its development over the past few decades indicates that the upgradation of the national unit capacity structure(including installing advanced production and phasing out backward production)plays a more important role.A quantitative study on the effect of the unit capacity structure upgradation on the decline in the national average NCCR suggests that phasing out backward production is the leading factor for the decline in the NCCR in the past decade,followed by the new installation,whose sum contributes to approximately 80%of the decline in the national average NCCR.The new installation has an effective affecting period of about 8 years,during which it would gradually decline from a relatively high value.Since the effect of phasing out backward production may remain at a certain degree given a continual action of phasing out backward capacity,it is suggested that the organized action of phasing out backward production should be insisted on. 展开更多
关键词 coal-fired power energy conservation net coal consumption rate new installation phasing out backward production unit capacity structure
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The Origination and Formation of Chinese Civilization
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作者 Jianye HAN Min HU 《Journal of the Chinese Nation Studies》 2023年第1期5-21,共17页
The Chinese civilization is a highly developed,long-standing and comprehensive entity,materially,spiritually and institutionally created by the Chinese nation.Around 6000 BC,Early China in the cultural sense bears its... The Chinese civilization is a highly developed,long-standing and comprehensive entity,materially,spiritually and institutionally created by the Chinese nation.Around 6000 BC,Early China in the cultural sense bears its root,marking the first stage of the origin of Chinese civilization.Around 4000 BC,Early China in the cultural sense formally takes shape,marking the second stage of the origin of Chinese civilization.Around 3100 BC,with the emergence of Chinese civilization,the stage of the Archaic State begins.Around 2100 BC,Early China enters the stage of the Dynastic State.Chinese civilization,with its universalistic cosmology and united structure,is of a unique"Tianxia(all under heaven)civilization"pattern.The"Tianxia civilization"patern,together with other cultural genes such as ritualism,ancestral worship,sincerity,benevolence,and coexistence of all in harmony,is the root cause for the continuous development of Chinese civilization to date. 展开更多
关键词 Chinese civilization Early cultural China Chinese nation Tianxia civilization united structure
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Critical assessment of three kinds of activity coefficients of carbon and related mixing thermodynamic functions of Fe-C binary melts based on atom-molecule coexistence theory
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作者 Xue-min Yang Jin-yan Li +2 位作者 Fang-jia Yan Dong-ping Duan Jian Zhang 《Journal of Iron and Steel Research(International)》 SCIE EI CAS CSCD 2018年第2期181-199,共19页
Raoultian activity coefficients γ0c of C in infinitely dilute Fe-C binary melts at temperatures of 1833, 1873, 1923, and 1973 K have been determined from the converted mass action concentrations Nc of C in Fe-C binar... Raoultian activity coefficients γ0c of C in infinitely dilute Fe-C binary melts at temperatures of 1833, 1873, 1923, and 1973 K have been determined from the converted mass action concentrations Nc of C in Fe-C binary melts by the developed AMCT-Ni model based on the atom-molecule coexistence theory (AMCT). The obtained expression of γ0c by the developed AMCT-Ni model has been evaluated to be accurate based on the reported ones from the literature. Meanwhile, three activity coefficients γc,f%,c, andfH,c of C coupled with activity aR,C or a%,c or aH,c have been obtained by the developed AMCT-Ni model and assessed through comparing with the predicted ones by other models from the literature. The first-order activity interaction coefficients ec, ec, and hcc related to γc f%,c, and fH,c are also determined and assessed in comparison with the reported ones from the literature. Furthermore, the integral molar mixing thermodynamic functions such as AmixHm,Fe-C, △mix-Sm,Fe-C, and △mixGm,Fe-C of Fe-C binary melts over a temperature range from 1833 to 1973 K have been determined and evaluated to be valid based on the determined ones from the literature. 展开更多
关键词 Fe-C binary melt Carbon activity coefficient Molar mixing thermodynamic functions Atom-moleculecoexistence theory Mass action concentration Thermodynamic model Assessment Structural unit
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A Systems-Science-Based Knowledge Explanation Method
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作者 李膺春 《Tsinghua Science and Technology》 SCIE EI CAS 2001年第1期49-56,共8页
Systems Science principles are the universal fundamental philosophical principles for analyzing, understanding, reforming and perfecting the objective world. This paper presents a Systems-Science-Based Knowledge Model... Systems Science principles are the universal fundamental philosophical principles for analyzing, understanding, reforming and perfecting the objective world. This paper presents a Systems-Science-Based Knowledge Model (SSBKM) to establish a more general knowledge structure model. It can be regarded as a development of frame representation for discovering and constructing slot structures as well as the frame structures. With this model the paper also presents a System-Sciences-Based Object-Oriented Analysis method (SSBOOA), which is a strategy to find and determine object classes and class structures, the relations between object instances of different classes, not to just explain classes. Finally, the paper illustrates knowledge analysis and computerizing (synthesizing) steps in an example of SSBKM of cognitive psychology-based CAI Network for Teaching Middle School Mathematics. 展开更多
关键词 Systems-Science-Based Knowledge Model (SSBKM) knowledge unit structure of units of knowledge Systems-Science-Based Object-Oriented Analysis (SSBOOA)
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Serration and Noise Behavior in Advanced Materials
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作者 Yong ZHANG Wei-hua WANG +2 位作者 Peter K.LIAW Gang WANG Jun-wei QIAO 《Journal of Iron and Steel Research(International)》 SCIE EI CAS CSCD 2016年第1期1-1,共1页
The Chinese Materials Research Society(C-MRS)Conference(2015)was held in the Guizhou Park Hotel International Conference Center,Guiyang,China,from July 10-14,2015.This conference consists of 30symposia,including 4... The Chinese Materials Research Society(C-MRS)Conference(2015)was held in the Guizhou Park Hotel International Conference Center,Guiyang,China,from July 10-14,2015.This conference consists of 30symposia,including 4international symposia.As one of 4international symposia,"Serration and noise behavior in advanced materials" 展开更多
关键词 Plastic deformation and serration behavior High entropy and amorphous alloys Structural flow units for plastic deformation Deformation behaviour in AlMg alloys Twinning Behavior in titanium alloy
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