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锂离子电池正极材料Li_xMn_2O_4电子结构的量子化学DV-X_α研究 被引量:6
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作者 李荣 陈昌国 +1 位作者 梁国明 余丹梅 《中国有色金属学报》 EI CAS CSCD 北大核心 2004年第5期865-870,共6页
采用原子基表示的第一原理赝势DV Xα方法,计算了锂离子电池正极材料LixMn2O4(x=0,1,2)各种模型的电子结构。结果表明:电极材料LixMn2O4具有较好的电子导电性,锂离子嵌入正极材料后发生Jahn Teller效应引起材料结构改变;锂离子的净电荷... 采用原子基表示的第一原理赝势DV Xα方法,计算了锂离子电池正极材料LixMn2O4(x=0,1,2)各种模型的电子结构。结果表明:电极材料LixMn2O4具有较好的电子导电性,锂离子嵌入正极材料后发生Jahn Teller效应引起材料结构改变;锂离子的净电荷变为+0.7(x=1)、+0.9或+0.5(x=2),说明锂离子过度嵌入LixMn2O4中,导致部分锂离子和氧离子的相互作用增强,锂离子脱出较为困难,从而容量降低。最高占有轨道(HOMO)到最低空轨道(LUMO)的跃迁能很小,电子较易进行嵌入和脱出。 展开更多
关键词 锂离子电池 LiχMn2O4 量子化学dv-xα方法
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量子化学DV-X_α方法研究煤大分子的稠环芳香结构与电子光谱 被引量:1
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作者 陈昌国 《重庆师专学报》 1999年第2期5-8,共4页
煤的颜色主要由其中稠环芳香结构大π键的大小决定。稠环芳烃的电子光谱规律表明,省系化合物的最大吸收波长(λmax)随其苯环个数变化最快,庚省以上即多于7个苯环时λmax≥700nm;其它低H/C比稠苯的λmax相应要小些,具有10个苯环的... 煤的颜色主要由其中稠环芳香结构大π键的大小决定。稠环芳烃的电子光谱规律表明,省系化合物的最大吸收波长(λmax)随其苯环个数变化最快,庚省以上即多于7个苯环时λmax≥700nm;其它低H/C比稠苯的λmax相应要小些,具有10个苯环的二蒽嵌四并苯λmax=460nm。量子化学离散变分(DV)Xα方法计算结果表明13个苯环的稠环芳香结构单元的HOMO→LUMO跃迁的λmax=537nm,煤中存在13个苯环以上的稠环芳香结构单元。 展开更多
关键词 稠环芳香结构 电子光谱 量子化学 dv-xα计算
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Fe_4N电子结构与磁性质的DV-X_α方法研究 被引量:3
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作者 杨菁 吴明 《华中师范大学学报(自然科学版)》 CAS CSCD 北大核心 2004年第3期301-303,共3页
用DV-Xα方法对Fe4N的电子结构和磁矩进行了研究.计算结果表明,在Fe4N的体心面心立方结构中,Fe原子在两种不等价晶位上,它们的磁矩是不同的,并从微观机理上作了相应的解释.
关键词 Fe4N 电子结构 磁矩 态密度 dv-xα方法
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贮氢材料VH_x(x=0,1,2)电子结构的DV-X_α研究 被引量:5
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作者 李荣 周上祺 +2 位作者 梁国明 刘守平 陈昌国 《中国有色金属学报》 EI CAS CSCD 北大核心 2005年第3期391-396,共6页
利用电荷自洽离散变分 Xα(SCC DV Xα)方法计算了钒基固溶体中钒氢反应前后钒及其氢化物(VHx,x=0, 1, 2)的电子结构。对净电荷、键级和电子密度差的分析表明: VH和 VH2 中 V—H键之间既有离子性又有共价性的相互作用。VH2 中V—H之间... 利用电荷自洽离散变分 Xα(SCC DV Xα)方法计算了钒基固溶体中钒氢反应前后钒及其氢化物(VHx,x=0, 1, 2)的电子结构。对净电荷、键级和电子密度差的分析表明: VH和 VH2 中 V—H键之间既有离子性又有共价性的相互作用。VH2 中V—H之间的键级比 VH中 V—H之间的键级小, 说明 VH2 中的 H容易释放出来。对能级结构、态密度和价轨道集居数的分析表明, 氢化物VH中是V的4s轨道和H的1s轨道作用成键; 氢化物VH2 中是V的4s、3d轨道和H的1s轨道作用成键; VH比VH2 的费米能级低, 说明VH更稳定。解释了VH2 中的氢不能全部放出的原因。 展开更多
关键词 钒氢化物 电子结构 SCC-dv-xα方法
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SCC-DV-X_α方法的应用(I)─—反应机理研究 被引量:1
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作者 欧光南 曹学功 屈爱存 《集美大学学报(自然科学版)》 CAS 北大核心 1997年第2期26-29,共4页
应用电荷自洽离散变分α近似计算方法,对Oppenauer氧化反应机理进行量子化学研究.计算结果表明:Oppenauer氧化反应发生环内氢负离子转移。
关键词 SCC-dv-x_α方法 Oppenauer氧化 反应机理
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用量子化学 SCC-DV-X_α 方法研究 C_3AH_6 和 C_3(A,F)H_6 的结构稳定性 被引量:3
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作者 李北星 冯修吉 《建筑材料学报》 EI CAS CSCD 1998年第1期54-56,共3页
用量子化学的SCCDVXα方法对水化物C3AH6和C3(A,F)H6结构中的两个模型Al2Ca9O12和Fe2Ca9O12的化学键强度分别进行了计算.C3AH6结构中Ca—O,Al—O键较强而不易断裂,是它具有长... 用量子化学的SCCDVXα方法对水化物C3AH6和C3(A,F)H6结构中的两个模型Al2Ca9O12和Fe2Ca9O12的化学键强度分别进行了计算.C3AH6结构中Ca—O,Al—O键较强而不易断裂,是它具有长期稳定性的本质原因.键级大小、HOMO能级、LUMO与HOMO能级差等计算结果证明由Fe置换C3AH6中的Al所形成的C3(A,F)H6固溶体其结构稳定性将下降. 展开更多
关键词 C3AH6 C3(A F)H6 稳定性 水化物 水泥 量子化学
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H_2、O_2和CO在PPRUC络合物上吸附的DV-X_α研究
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作者 曹中秋 吴林友 +1 位作者 刘尚长 闫丽静 《分子科学学报》 CAS CSCD 1999年第1期55-60,共6页
中图分类号O6414文献标识码A导电聚合物是现代科学技术理论发展中一个相当活跃的研究领域.近年来,新的导电高分子材料不断涌现,正日益朝着具有弹性、塑性、导电性、导热性、导磁性、抗蚀性、质量轻及易加工等方向发展.在众... 中图分类号O6414文献标识码A导电聚合物是现代科学技术理论发展中一个相当活跃的研究领域.近年来,新的导电高分子材料不断涌现,正日益朝着具有弹性、塑性、导电性、导热性、导磁性、抗蚀性、质量轻及易加工等方向发展.在众多的导电聚合物家族中,掺杂聚吡咯因... 展开更多
关键词 掺杂聚吡咯 吸附 dv-x_α方法
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量子化学SCC-DV-X_α计算方法在水泥化学研究中的应用 被引量:1
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作者 李北星 程新 《建筑材料学报》 EI CAS CSCD 1999年第2期147-152,共6页
探讨了量子化学在水泥化学领域应用研究的基本思想,对近几年来应用量子化学SCCDVXα计算方法研究一些水泥熟料矿物价键结构与水化活性、水化产物相的力学强度和稳定性等问题所得到的结果进行了综述与评价。
关键词 量子化学 SCC-dv-xa算法 水泥 水化性能
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碱金属叠氮化物电子结构和稳定性的DV-X_α计算研究 被引量:1
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作者 李永富 肖鹤呜 《无机化学学报》 SCIE CAS CSCD 北大核心 1993年第4期342-346,共5页
首次对系列碱金属(Li、Na、K、Rb和Cs)叠氮化物在基态和激发态下的电子结构进行了基函数电荷自洽的DV-X_α计算.根据热解机理、考察前沿轨道的能级和组成以及电子在前沿轨道之间的跃迁,阐明了碱金属叠氮化物的感度很小的实验事实.
关键词 碱金属 叠氮化物 稳定性 电子结构
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NO在NiO(100)面吸附的DV-X_α簇模型研究
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作者 吕鑫 徐昕 +1 位作者 王南钦 张乾二 《物理化学学报》 SCIE CAS CSCD 北大核心 1995年第9期796-800,共5页
采用量子化学的SCC-DV-Xα嵌入簇模型方法考察了NO/NiO(100)吸附体系的两种不同吸附方式:以N端在正离子顶位的垂直线性吸附和弯折式吸附方式.结果表明:1)在两种吸附方式下,NO都是电子受体;2)NO与表面正离子间的成键行为尽... 采用量子化学的SCC-DV-Xα嵌入簇模型方法考察了NO/NiO(100)吸附体系的两种不同吸附方式:以N端在正离子顶位的垂直线性吸附和弯折式吸附方式.结果表明:1)在两种吸附方式下,NO都是电子受体;2)NO与表面正离子间的成键行为尽管类似于金属亚硝基化合物,但表面电场的作用不容忽视,它是使得吸附的N-O键的σ成链增强的主因.定性解释了NO/NiO(100)面吸附体系的IR光谱行为. 展开更多
关键词 吸附 嵌入簇 一氧化氮 氧化镍
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CaO-Al_2O_3系统铝酸钙矿物水化活性差异的SCC-DV-X_α方法研究 被引量:10
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作者 李北星 余其俊 冯修吉 《硅酸盐学报》 EI CAS CSCD 北大核心 1998年第4期411-416,共6页
建立了CaO-Al2O3系统C3A,C12A7,CA,CA2和CA65种铝酸钙化合物的计算模型并分别对它们进行了量子化学的电荷自洽离散变分Xα法(SCC-DV-Xα)计算.计算结果表明:5种矿物的Ca—O共价键级大小... 建立了CaO-Al2O3系统C3A,C12A7,CA,CA2和CA65种铝酸钙化合物的计算模型并分别对它们进行了量子化学的电荷自洽离散变分Xα法(SCC-DV-Xα)计算.计算结果表明:5种矿物的Ca—O共价键级大小呈C3A<C12A7<CA<CA2<CA6排列,最低空分子轨道(LUMO)与最高占据分子轨道(HOMO)能级之差也基本按上述顺序呈递增趋势,可以认为这是以上5种矿物水化活性依序降低的主要原因. 展开更多
关键词 铝酸钙矿物 水化活性 水泥 SCC-dv-xα 原料
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A Review on Sources,Extractions and Analysis Methods of a Sustainable Biomaterial:Tannins 被引量:2
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作者 Antonio Pizzi Marie-Pierre Laborie Zeki Candan 《Journal of Renewable Materials》 EI CAS 2024年第3期397-425,共29页
Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly ... Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly to substitute petroleum-based products.They are a definite class of sustainable materials of the forestry industry.They have been in operation for hundreds of years to manufacture leather and now for a growing number of applications in a variety of other industries,such as wood adhesives,metal coating,pharmaceutical/medical applications and several others.This review presents the main sources,either already or potentially commercial of this forestry by-materials,their industrial and laboratory extraction systems,their systems of analysis with their advantages and drawbacks,be these methods so simple to even appear primitive but nonetheless of proven effectiveness,or very modern and instrumental.It constitutes a basic but essential summary of what is necessary to know of these sustainable materials.In doing so,the review highlights some of the main challenges that remain to be addressed to deliver the quality and economics of tannin supply necessary to fulfill the industrial production requirements for some materials-based uses. 展开更多
关键词 TANNINS FLAVONOIDS SOURCES extraction methods analysis methods
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SCC-DV-X_α方法的应用Ⅱ.催化活性研究
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作者 欧光南 曹学功 《集美大学学报(自然科学版)》 CAS 北大核心 2001年第1期29-33,共5页
应用电荷自洽离散变分Xα 方法 (SCC DV Xα)和动力学实验 ,研究了酸碱催化剂对羰基化合物离子型反应的催化活性 .对甲醛模型物的SCC DV Xα 计算表明 ,碱催化剂对甲醛羰基的活化作用比酸催化剂强 ,碱催化剂的催化作用与羰基π键的削弱... 应用电荷自洽离散变分Xα 方法 (SCC DV Xα)和动力学实验 ,研究了酸碱催化剂对羰基化合物离子型反应的催化活性 .对甲醛模型物的SCC DV Xα 计算表明 ,碱催化剂对甲醛羰基的活化作用比酸催化剂强 ,碱催化剂的催化作用与羰基π键的削弱有关 ,而酸催化剂能提高羰基碳原子的亲电能力 .动力学实验结果与计算结果相一致 . 展开更多
关键词 SCC-dv-xα方法 羰基化合物 催化活性 酸碱催化剂 亲电能力 电荷自洽离散变分Xα方法
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INFLUENCE OF ALLOYING ELEMENTS ON HYDROGEN DIFFUSION USING SCM-DV-X_α
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作者 Y.Huang D.M.Xing 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2004年第1期71-76,共6页
The influence of alloy composition (Ti, Mn, TiN) on hydrogen diffusion in Fe was studied in detail using SCM-DV-Xα method. The voltage barriers were obtained via calculation on Fe clusters containing the alloy elemen... The influence of alloy composition (Ti, Mn, TiN) on hydrogen diffusion in Fe was studied in detail using SCM-DV-Xα method. The voltage barriers were obtained via calculation on Fe clusters containing the alloy elements such as Ti, Mn as well as the chemical compound TiN respectively. The results showed that Ti element produced deep trap in Fe, decreasing the diffusion coefficient of hydrogen elements, Mn element did not produce deep trap in Fe, decreasing the diffusion coefficient slightly and TiN in Fe produced very deep "trap" decreasing the diffusion coefficient obviously. The calculation results were in agreement with experiment results. 展开更多
关键词 hydrogen diffusion SCM-dv-xα method CLUSTER
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Drilling-based measuring method for the c-φ parameter of rock and its field application 被引量:3
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作者 Bei Jiang Fenglin Ma +5 位作者 Qi Wang Hongke Gao Dahu Zhai Yusong Deng Chuanjie Xu Liangdi Yao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第1期65-76,共12页
The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(R... The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters. 展开更多
关键词 Digital drilling Rock crushing zone c-u parameter Measurement method Field application
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A comparison study on structure-function relationship of polysaccharides obtained from sea buckthorn berries using different methods:antioxidant and bile acid-binding capacity 被引量:5
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作者 Qiaoyun Li Zuman Dou +5 位作者 Qingfei Duan Chun Chen Ruihai Liu Yueming Jiang Bao Yang Xiong Fu 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期494-505,共12页
In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic... In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods. 展开更多
关键词 Sea buckthorn Extraction method STRUCTURE Rheological properties Antioxidant activity Bile acid binding capacity
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Material point method simulation of hydro-mechanical behaviour in twophase porous geomaterials: A state-of-the-art review 被引量:2
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作者 Xiangcou Zheng Shuying Wang +1 位作者 Feng Yang Junsheng Yang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2341-2350,共10页
The material point method(MPM)has been gaining increasing popularity as an appropriate approach to the solution of coupled hydro-mechanical problems involving large deformation.In this paper,we survey the current stat... The material point method(MPM)has been gaining increasing popularity as an appropriate approach to the solution of coupled hydro-mechanical problems involving large deformation.In this paper,we survey the current state-of-the-art in the MPM simulation of hydro-mechanical behaviour in two-phase porous geomaterials.The review covers the recent advances and developments in the MPM and their extensions to capture the coupled hydro-mechanical problems involving large deformations.The focus of this review is aiming at providing a clear picture of what has or has not been developed or implemented for simulating two-phase coupled large deformation problems,which will provide some direct reference for both practitioners and researchers. 展开更多
关键词 Coupled problems Hydro-mechanical behaviour Large deformation Material Point method(MPM)
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用DV-X_α法与用单原子理论计算单质铁电子结构及性质的比较 被引量:2
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作者 彭浩 谢佑卿 +2 位作者 王崇愚 王山鹰 彭坤 《中国有色金属学报》 EI CAS CSCD 北大核心 2001年第3期477-480,共4页
利用密度泛函理论中的电荷自洽离散变分Xα 方法 (Self consistent chargediscretevariationalmethod ,简称DVM或DV Xα 方法 )计算出单质Fe的电子结构为 (3dc) 4.0 77(3dm) 2 .190 (4sc+4sf) 0 .790 (4p) 0 .94 3 ,结合能为5 2 9.30 7k... 利用密度泛函理论中的电荷自洽离散变分Xα 方法 (Self consistent chargediscretevariationalmethod ,简称DVM或DV Xα 方法 )计算出单质Fe的电子结构为 (3dc) 4.0 77(3dm) 2 .190 (4sc+4sf) 0 .790 (4p) 0 .94 3 ,结合能为5 2 9.30 7kJ/mol,磁矩为 18.82× 10 2 4 A·m2 。将该法计算结果与纯金属单原子理论 (即OA理论 )所得结果进行了比较 ,并讨论了两种方法的优劣。 展开更多
关键词 电子结构 电荷自治离散变分Xα法 材料设计 OA理论
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Deciphering gastric inflammation-induced tumorigenesis through multi-omics data and AI methods 被引量:1
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作者 Qian Zhang Mingran Yang +3 位作者 Peng Zhang Bowen Wu Xiaosen Wei Shao Li 《Cancer Biology & Medicine》 SCIE CAS CSCD 2024年第4期312-330,共19页
Gastric cancer(GC), the fifth most common cancer globally, remains the leading cause of cancer deaths worldwide. Inflammation-induced tumorigenesis is the predominant process in GC development;therefore, systematic re... Gastric cancer(GC), the fifth most common cancer globally, remains the leading cause of cancer deaths worldwide. Inflammation-induced tumorigenesis is the predominant process in GC development;therefore, systematic research in this area should improve understanding of the biological mechanisms that initiate GC development and promote cancer hallmarks. Here, we summarize biological knowledge regarding gastric inflammation-induced tumorigenesis, and characterize the multi-omics data and systems biology methods for investigating GC development. Of note, we highlight pioneering studies in multi-omics data and state-of-the-art network-based algorithms used for dissecting the features of gastric inflammation-induced tumorigenesis, and we propose translational applications in early GC warning biomarkers and precise treatment strategies. This review offers integrative insights for GC research, with the goal of paving the way to novel paradigms for GC precision oncology and prevention. 展开更多
关键词 Gastric cancer inflammation-induced tumorigenesis multi-omics artificial intelligence network-based methods
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Volumetric lattice Boltzmann method for pore-scale mass diffusionadvection process in geopolymer porous structures 被引量:1
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作者 Xiaoyu Zhang Zirui Mao +6 位作者 Floyd W.Hilty Yulan Li Agnes Grandjean Robert Montgomery Hans-Conrad zur Loye Huidan Yu Shenyang Hu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2126-2136,共11页
Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste streams.To improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advecti... Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste streams.To improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advection process within porous structures is essential for material design.In this study,we present advancements in the volumetric lattice Boltzmann method(VLBM)for modeling and simulating pore-scale diffusion-advection of radioactive isotopes within geopolymer porous structures.These structures are created using the phase field method(PFM)to precisely control pore architectures.In our VLBM approach,we introduce a concentration field of an isotope seamlessly coupled with the velocity field and solve it by the time evolution of its particle population function.To address the computational intensity inherent in the coupled lattice Boltzmann equations for velocity and concentration fields,we implement graphics processing unit(GPU)parallelization.Validation of the developed model involves examining the flow and diffusion fields in porous structures.Remarkably,good agreement is observed for both the velocity field from VLBM and multiphysics object-oriented simulation environment(MOOSE),and the concentration field from VLBM and the finite difference method(FDM).Furthermore,we investigate the effects of background flow,species diffusivity,and porosity on the diffusion-advection behavior by varying the background flow velocity,diffusion coefficient,and pore volume fraction,respectively.Notably,all three parameters exert an influence on the diffusion-advection process.Increased background flow and diffusivity markedly accelerate the process due to increased advection intensity and enhanced diffusion capability,respectively.Conversely,increasing the porosity has a less significant effect,causing a slight slowdown of the diffusion-advection process due to the expanded pore volume.This comprehensive parametric study provides valuable insights into the kinetics of isotope uptake in porous structures,facilitating the development of porous materials for nuclear waste treatment applications. 展开更多
关键词 Volumetric lattice Boltzmann method(VLBM) Phase field method(PFM) Pore-scale diffusion-advection Nuclear waste treatment Porous media flow Graphics processing unit(GPU) parallelization
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