期刊文献+
共找到510篇文章
< 1 2 26 >
每页显示 20 50 100
A probable new phase H(Ni_2Ti_9Si_9) in Ti-Ni-Si ternary system at 1100 ℃
1
作者 HU Xiaohua CHEN Guoliang NI Kequan (State Key hab for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China) 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 1997年第3期5-7,共3页
A probable new phase was detected in Ni-Ti-Si temary system at 1 100 ℃. ItS composition is aroundM: T: Si = 10: 45: 45 (atom fraction) according to the results of EPMA (Electron Probe Microanalysis) of 4 alloyscontai... A probable new phase was detected in Ni-Ti-Si temary system at 1 100 ℃. ItS composition is aroundM: T: Si = 10: 45: 45 (atom fraction) according to the results of EPMA (Electron Probe Microanalysis) of 4 alloyscontaining the Phase. The SEM microstructure difference of the 4 alloys can give some proof of its existence. 展开更多
关键词 new phase H (Ni_2Ti_9Si_9) phase microstructure chemical composition
下载PDF
New Phase Ti_3Co_2Si in the Ti-Co-Si Ternary System at 1100℃
2
作者 Xianhua HU, Guoliang CHEN, Cinca Ion and Kequan NI (State Key Lab. for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第1期91-93,共3页
A new phase with the appropriate composition of Ti_3Co_2Si is found to exist at 1100℃. The X-ray diffraction of this phase can not be indexed by any other phase in the Ti-Co-Si ternary system and show this phase to b... A new phase with the appropriate composition of Ti_3Co_2Si is found to exist at 1100℃. The X-ray diffraction of this phase can not be indexed by any other phase in the Ti-Co-Si ternary system and show this phase to be hexagonal with the lattice parameter of α=0.676 nm, c=0.732 nm, c/α=1.0825. 展开更多
关键词 TI CO new phase Ti3Co2Si in the Ti-Co-Si Ternary System at 1100 SI
下载PDF
Process Dynamics and Fractal Analysis of New Phase Formation in Thermal Processes 被引量:6
3
作者 WangJ ShenZ.W 《Journal of Thermal Science》 SCIE EI CAS CSCD 2001年第2期153-158,115,共7页
Boiling and fouling are taken as typical examples of new phase formation process to be analyzed and discussed in this paper. The process dynamics of nucleate boiling is analyzed and its mechanism is discussed from the... Boiling and fouling are taken as typical examples of new phase formation process to be analyzed and discussed in this paper. The process dynamics of nucleate boiling is analyzed and its mechanism is discussed from the view point of self-organization. Fouling, which is a more complicated phenomenon of new phase formation, involves series of underlying processes. The morphology and fractal analysis of fouling on low-energy surface and that with fouling inhibitors are studied and discussed. It is suggested that considering the process dynamics, fractal analysis and self-organization, a new avenue of research should be found. 展开更多
关键词 new phase formation process dynamics fractal analysis SELF-ORGANIZATION thermal process
原文传递
The Asia-Pacific Economic cooperation Enters a New Phase
4
作者 陈鲁直 《World Economy & China》 SCIE 1997年第3期22-28,52,共8页
关键词 ASIA PFP The Asia-Pacific Economic cooperation Enters a new phase
原文传递
World Security Enters New Phase
5
作者 XU FEIBIAO 《Beijing Review》 2009年第51期12-13,共2页
The world community seeks answers tolooming terrorist threats The year of 2009 has witnessed an increasing amount of terrorism around the world—requiring
关键词 SECURITY TTP World Security Enters new phase
原文传递
New Phase For Auto Industry
6
作者 Zhang Xiaoyu, Director of Automotive Industry Bureau of MMI 《中国汽车(英文版)》 1995年第4期1-6,共2页
Automotive manufacturing at the present time is still a growing industry and it is crucial to the economy of the nation. Since the 1950s, particularly in the year 1979 when rapid growth began because of the adoption o... Automotive manufacturing at the present time is still a growing industry and it is crucial to the economy of the nation. Since the 1950s, particularly in the year 1979 when rapid growth began because of the adoption of economic restructuring and the opening policy, China has worked economic magic and has made great achievement in the automotive industry. 展开更多
关键词 AUTO new phase For Auto Industry
原文传递
New Dispersed Phase of Electrorheological Fluids:TiO_2 Coating Graphite Particles 被引量:2
7
作者 Sujuan XU+ and Biao WANG (Harbin Institute of Technology, Harbin 150001, China) Shouqiang MEN and Kunquan LU (Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第5期529-530,共2页
We have prepared novel coated particles, with a conductor graphite core and a dielectric TiO2 coating, as the dispersed phase of electrorheological fluids. One order of magnitude enhancement in the shear stress is obt... We have prepared novel coated particles, with a conductor graphite core and a dielectric TiO2 coating, as the dispersed phase of electrorheological fluids. One order of magnitude enhancement in the shear stress is obtained by using such composite particles, when it is compared with that of TiO2 particles. The experimental results show a way to get excellent ER system. 展开更多
关键词 new Dispersed phase of Electrorheological Fluids GRAPHITE TIO
下载PDF
Two Side Chain β-CD Polysiloxanes Used as New Stationary Phase for Chiral Separation by HRGC 被引量:1
8
作者 Han Bang ZHANG Yun LING +1 位作者 Ruo Nong FU Yu Xiu WEN(Department of Chemical Engineering. Beijing Institute of Technology. Beijing 100081) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第2期165-166,共2页
Two new stationary phases : (Ⅰ) [bikis(2,6-di-O-pentyl-3-O-hex-6O-pentyl-3-O-methyl)-β-CD-polysiloxane] and (Ⅱ) [heptkis(2,6-di-O-methyl-3-O-hex-6-enyl)-β-CD-polysiloxane] were synthesized and successfully used fo... Two new stationary phases : (Ⅰ) [bikis(2,6-di-O-pentyl-3-O-hex-6O-pentyl-3-O-methyl)-β-CD-polysiloxane] and (Ⅱ) [heptkis(2,6-di-O-methyl-3-O-hex-6-enyl)-β-CD-polysiloxane] were synthesized and successfully used for GC separation of chiral isomers.The possess high column efficiency and exhibit fine chiral separation ability. 展开更多
关键词 HRGC CD Polysiloxanes Used as new Stationary phase for Chiral Separation by HRGC Two Side Chain
下载PDF
PREPARATION AND PROPERTIES OF THE MICRO-POWDER PHASE AND A NEW PHASE OF AMMONIUM TETRAMOLYBDATES 被引量:1
9
作者 Yin, Zhoulan Chen, Qiyuan +3 位作者 Zhang, Hengzhong Zhou, Guizhi Li, Yuangao Zhang, Pingmin 《中国有色金属学会会刊:英文版》 EI CSCD 1997年第1期19-22,共4页
PREPARATIONANDPROPERTIESOFTHEMICROPOWDERPHASEANDANEWPHASEOFAMMONIUMTETRAMOLYBDATES①YinZhoulan,ChenQiyuan,Zh... PREPARATIONANDPROPERTIESOFTHEMICROPOWDERPHASEANDANEWPHASEOFAMMONIUMTETRAMOLYBDATES①YinZhoulan,ChenQiyuan,ZhangHengzhong,Zhou... 展开更多
关键词 new phase of AMMONIUM tetramolybdate micro POWDER phase of AMMONIUM tetramolybdate phase transformation MOLYBDENUM
下载PDF
New ordered MAX phase Mo_2 TiAlC_2: Elastic and electronic properties from first-principles
10
作者 M A Hadi M S Ali 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第10期323-329,共7页
First-principles computation on the basis of density functional theory(DFT) is executed with the CASTEP code to explore the structural, elastic, and electronic properties along with Debye temperature and theoretical V... First-principles computation on the basis of density functional theory(DFT) is executed with the CASTEP code to explore the structural, elastic, and electronic properties along with Debye temperature and theoretical Vickers’ hardness of newly discovered ordered MAX phase carbide Mo2TiAlC2. The computed structural parameters are very reasonable compared with the experimental results. The mechanical stability is verified by using the computed elastic constants. The brittleness of the compound is indicated by both the Poisson’s and Pugh’s ratios. The new MAX phase is capable of resisting the pressure and tension and also has the clear directional bonding between atoms. The compound shows significant elastic anisotropy. The Debye temperature estimated from elastic moduli(B, G) is found to be 413.6 K. The electronic structure indicates that the bonding nature of Mo2TiAlC2is a mixture of covalent and metallic with few ionic characters. The electron charge density map shows a strong directional Mo–C–Mo covalent bonding associated with a relatively weak Ti–C bond.The calculated Fermi surface is due to the low-dispersive Mo 4d-like bands, which makes the compound a conductive one.The hardness of the compound is also evaluated and a high value of 9.01 GPa is an indication of its strong covalent bonding. 展开更多
关键词 new ordered MAX phase density functional theory calculations Debye temperature Vickers hardness
下载PDF
Africa Ushering in a New Historical Phase
11
作者 Wang Yingying is Senior Research Fellow at China Institute of International Studies. 《China International Studies》 2006年第3期15-32,共18页
Africa, which comprises a significant number of developing countries, is an important force working for world peace and stability and global economic development. The African continent is rich in natural and human res... Africa, which comprises a significant number of developing countries, is an important force working for world peace and stability and global economic development. The African continent is rich in natural and human resources and potentials for development. For years, however, Africa gave people the impression that it was a poverty-stricken, backward land ravaged by successive wars and epidemic diseases. Since the beginning of the 21st century, there have been 展开更多
关键词 Africa Ushering in a new Historical phase
下载PDF
New conserved quantities of Noether-Mei symmetry of mechanical system in phase space 被引量:4
12
作者 方建会 刘仰魁 张小妮 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第6期1962-1966,共5页
This paper studies two new types of conserved quantities deduced by Noether Mei symmetry of mechanical system in phase space. The definition and criterion of Noether Mei symmetry for the system are given. A coordinati... This paper studies two new types of conserved quantities deduced by Noether Mei symmetry of mechanical system in phase space. The definition and criterion of Noether Mei symmetry for the system are given. A coordination function is introduced, and the conditions under which the Noether- Mei symmetry leads to the two types of conserved quantities and the forms of the two types of conserved quantities are obtained. An illustrative example is given. The coordination function can be selected according to the demand for finding the gauge function, and the choice of the coordination function has multiformity, so more conserved quantities deduced from Noether Mei symmetry of mechanical system can be obtained. 展开更多
关键词 mechanical system phase space Noether-Mei symmetry new conserved quantity
下载PDF
Tentative New Terminology: Initial Comedonal Phase Preceding Acute Inflammatory Phase of Acne Vulgaris—Importance of Early Treatment
13
作者 Ichiro Kurokawa Yuko Nomura Toshitatsu Nogita 《Journal of Cosmetics, Dermatological Sciences and Applications》 2023年第3期179-181,共3页
We report a case of a 12-year-old female with closed and open comedo without inflammatory lesions at the first visit. She had been treated with topical adapalene once daily, and closed and open comedo subsided without... We report a case of a 12-year-old female with closed and open comedo without inflammatory lesions at the first visit. She had been treated with topical adapalene once daily, and closed and open comedo subsided without inflammatory lesions one month after the treatment without any side effects induced by adapalen. The recurrence of comedo had not been observed afterwards. In the Japanese Dermatological Association (JDA) guidelines for the treatment of acne vulgaris, comedonal phase has not been stated. Then we propose the tentative new terminology of a comedonal phase and emphasize its importance in the early initial treatment for comedo to prevent the development of the acute inflammatory phase such as red papules and pustules and formation of acne scars. 展开更多
关键词 Comedonal phase new Terminology Early Initial Treatment
下载PDF
A new type of conserved quantity of Mei symmetry for relativistic nonholonomic mechanical system in phase space
14
作者 张小妮 方建会 +1 位作者 庞婷 蔺鹏 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第2期394-398,共5页
In this paper, a new type of conserved quantity induced directly from the Mei symmetry for a relativistic nonholonomic mechanical system in phase space is studied. The definition and the criterion of the Mei symmetry ... In this paper, a new type of conserved quantity induced directly from the Mei symmetry for a relativistic nonholonomic mechanical system in phase space is studied. The definition and the criterion of the Mei symmetry for the system are given. The conditions for the existence and form of the new conserved quantity are obtained. Finally, an example is given to illustrate the application of the result. 展开更多
关键词 RELATIVITY phase space Mei symmetry new type of conserved quantity
下载PDF
Phase2软件在隧洞开挖围岩支护时机中的应用 被引量:6
15
作者 何欣 曹怀园 +1 位作者 刘永智 刘洁玉 《西北水电》 2015年第3期49-53,共5页
新奥法支护理论允许围岩变形,"适时"支护,能够保证围岩稳定的前提下,减少支护措施。文章利用phase2软件,引入应力释放法和弹性模量折减法解决"适时"的问题,将新奥法理论应用于德尔西水电站工程引水隧洞支护结构设计... 新奥法支护理论允许围岩变形,"适时"支护,能够保证围岩稳定的前提下,减少支护措施。文章利用phase2软件,引入应力释放法和弹性模量折减法解决"适时"的问题,将新奥法理论应用于德尔西水电站工程引水隧洞支护结构设计中,采用量化、清晰易懂的方式证明了合理地选择支护时机可以优化支护结构、减少工程投资,对隧洞工程支护结构设计具有实际意义。 展开更多
关键词 隧洞 支护时机 新奥法 位移 phase2 德尔西水电站
下载PDF
Hydrothermal Synthesis and Characterization of a Novel Low Temperature Phase K_4InTi_4O_(11) (OH)·5H_2O
16
作者 Wen Jun ZHENG Guang Yao MENG(Department of Materials Science and Engineering, University of Science and Technology ofChina, Hefei 230026)Yi Hua XU +1 位作者 Wen Qin PANG (Key Laboratory of inorganic Synthesis and Preparative Chemistry, Department of Chemistry, J 《Chinese Chemical Letters》 SCIE CAS CSCD 1998年第12期0-0,共2页
A novel low temperature phase K4InTi4O11 (OH)'5H2O was prepared by thehydrothermal method. The product was characterized by XRD, SEM, TG, DTA and ICP. Theresults indicated that the product crystallizes in a cubic ... A novel low temperature phase K4InTi4O11 (OH)'5H2O was prepared by thehydrothermal method. The product was characterized by XRD, SEM, TG, DTA and ICP. Theresults indicated that the product crystallizes in a cubic system with a cell parameter a=0.7868 um.Moreover, it ecomposes to an amorphous phase after calcining at 340 ℃. 展开更多
关键词 Hydroxy-oxide new low temperature phase hydrothermal synthesis
下载PDF
First-principles study of two new boron nitride structures:C12-BN and O16-BN
17
作者 Hao Wang Yaru Yin +5 位作者 Xiong Yang Yanrui Guo Ying Zhang Huiyu Yan Ying Wang Ping Huai 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第2期503-508,共6页
Based on the first-principles method,we predict two new stable BN allotropes:C12-BN and O16-BN,which belong to cubic and orthorhombic crystal systems,respectively.It is confirmed that both the phases are thermally and... Based on the first-principles method,we predict two new stable BN allotropes:C12-BN and O16-BN,which belong to cubic and orthorhombic crystal systems,respectively.It is confirmed that both the phases are thermally and dynamically stable.The results of molecular dynamics simulations suggest that both the BN phases are highly stable even at high temperatures of 1000 K.In the case of mechanical properties,C12-BN has a bulk modulus of 359 GPa and a hardness of 43.4 GPa,making it a novel superhard material with potential technological and industrial applications.Electronic band calculations reveal that both C12-BN and O16-BN are insulators with direct band gaps of 3.02 e V and 3.54 e V,respectively.The XRD spectra of C12-BN and O16-BN are also simulated to provide more information for possible experimental observation.Our findings enrich the BN allotrope family and are expected to stimulate further experimental interest. 展开更多
关键词 new boron nitride phase first-principles calculations mechanical properties electric properties
下载PDF
中国式产能过剩:历史考察及对新发展阶段治理的启示 被引量:1
18
作者 梁泳梅 《江汉大学学报(社会科学版)》 2024年第1期102-116,共15页
改革开放以来,我国经历了四轮较为明显的产能过剩:20世纪90年代的消费品过剩阶段、2003—2007年的部分工业品过剩阶段、2011—2015年的产能过剩全面加剧阶段、2016—2020年的重点行业治理取得阶段性成果阶段,各阶段产能过剩的背景、表... 改革开放以来,我国经历了四轮较为明显的产能过剩:20世纪90年代的消费品过剩阶段、2003—2007年的部分工业品过剩阶段、2011—2015年的产能过剩全面加剧阶段、2016—2020年的重点行业治理取得阶段性成果阶段,各阶段产能过剩的背景、表现、治理措施及效果不尽相同。历史考察发现,中国式产能过剩具有以下特征:产能过剩跟经济波动密切关联、产能过剩问题反复出现、产能过剩与落后产能问题并存、产能过剩形成机制深刻复杂。在新发展阶段,治理产能过剩问题既要推动存量过剩产能退出,更要从根本上构建预防过剩产能反复的长效机制,建议重点关注以下工作:完善市场化法治化机制,构建过剩产能高效退出机制;推动政府治理机制改革,探索政府与市场结合新模式;加快科技自主创新,推动供需结构匹配;加快构建“管资本”国有资产监管体制,重点推动国有企业产能利用率提升。 展开更多
关键词 产能过剩 需求端管理 供给侧结构性改革 新发展阶段
下载PDF
基于新扩展移相双有源全桥变换器降压-升压模式下电流应力优化
19
作者 陶海军 王宏祎 杨乃通 《上海交通大学学报》 EI CAS CSCD 北大核心 2024年第10期1585-1595,共11页
为降低双有源全桥变换器在降压-升压模式下的电流应力,提出一种基于新扩展移相调制的电流应力优化控制策略.首先,将变压器两端输出高电平电压之间移相量定义为外移相角,再对比分析降压-升压模式下内移相角在变压器不同侧时变换器的工作... 为降低双有源全桥变换器在降压-升压模式下的电流应力,提出一种基于新扩展移相调制的电流应力优化控制策略.首先,将变压器两端输出高电平电压之间移相量定义为外移相角,再对比分析降压-升压模式下内移相角在变压器不同侧时变换器的工作特性,根据移相角之间的关系划分为3种工作模态,得到电流应力表达式和功率模型.然后,对比分析得到优化工作模式,利用拉格朗日乘数法算法获取电流应力最优的相移组合.最后,搭建实验平台在降压-升压模式下对变换器进行验证,实验结果表明电流应力优化控制策略显著降低变换器在降压-升压模式下的电流应力. 展开更多
关键词 双有源全桥 新扩展移相 降压-升压模式 电流应力优化
下载PDF
扩展移相控制的DAB变换器双目标优化策略
20
作者 刘春喜 徐金荣 +1 位作者 刘文强 孙华泽 《电子测量与仪器学报》 CSCD 北大核心 2024年第10期180-190,共11页
为提高双有源桥变换器的传输效率,提出一种基于新扩展移相控制的电流应力和回流功率双目标权重优化策略。首先,根据原边侧输出电压高电平的角度和原副边输出电压之间的移相角关重新定义新移相比,简化传输功率数学模型,再由移相比之间的... 为提高双有源桥变换器的传输效率,提出一种基于新扩展移相控制的电流应力和回流功率双目标权重优化策略。首先,根据原边侧输出电压高电平的角度和原副边输出电压之间的移相角关重新定义新移相比,简化传输功率数学模型,再由移相比之间的关系划分出3种工作模式并求出对应的电流应力和传输功率数学模型;在此基础上,推导出回流功率数学模型并进行特性分析;然后,优选出两种覆盖全功率的工作模式并建立电流应力和回流功率权重优化函数,根据极差正规化法求解出最优移相比组合并分析其软开关特性;最后结合所求软开关条件下的最优移相比组合设计出简洁快速的闭环控制策略。通过搭建样机进行实验验证,在电流应力、回流功率以及传输效率方面对优化策略与传统策略进行对比分析。实验结果表明双目标优化策略相较于传统扩展移相控制在低功率模式下系统效率提升了20%,在高功率模式下系统效率提升了11%,验证了设计方案的可行性和有效性。 展开更多
关键词 双有源桥 扩展移相 电流应力 回流功率 权重优化 移相比
下载PDF
上一页 1 2 26 下一页 到第
使用帮助 返回顶部