全文获取类型
收费全文 | 502篇 |
免费 | 121篇 |
国内免费 | 61篇 |
专业分类
化学 | 135篇 |
晶体学 | 2篇 |
力学 | 292篇 |
综合类 | 5篇 |
数学 | 17篇 |
物理学 | 233篇 |
出版年
2023年 | 4篇 |
2022年 | 10篇 |
2021年 | 5篇 |
2020年 | 14篇 |
2019年 | 19篇 |
2018年 | 7篇 |
2017年 | 21篇 |
2016年 | 36篇 |
2015年 | 21篇 |
2014年 | 24篇 |
2013年 | 41篇 |
2012年 | 28篇 |
2011年 | 31篇 |
2010年 | 31篇 |
2009年 | 35篇 |
2008年 | 35篇 |
2007年 | 35篇 |
2006年 | 21篇 |
2005年 | 24篇 |
2004年 | 40篇 |
2003年 | 28篇 |
2002年 | 21篇 |
2001年 | 15篇 |
2000年 | 16篇 |
1999年 | 15篇 |
1998年 | 13篇 |
1997年 | 13篇 |
1996年 | 16篇 |
1995年 | 9篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 10篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有684条查询结果,搜索用时 15 毫秒
221.
Explosive synchronization of multi-layer complex networks based on inter-layer star network connection
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yan-Liang Jin 《中国物理 B》2021,30(12):120505-120505
Explosive synchronization (ES) is a first-order transition phenomenon that is ubiquitous in various physical and biological systems. In recent years, researchers have focused on explosive synchronization in a single-layer network, but few in multi-layer networks. This paper proposes a frequency-weighted Kuramoto model in multi-layer complex networks with star connection between layers and analyzes the factors affecting the backward critical coupling strength by both theoretical analysis and numerical validation. Our results show that the backward critical coupling strength of each layer network is influenced by the inter-layer interaction strength and the average degree. The number of network layers, the number of nodes, and the network topology can not directly affect the synchronization of the network. Enhancing the inter-layer interaction strength can prevent the emergence of explosive synchronization and increasing the average degree can promote the generation of explosive synchronization. 相似文献
222.
Johnson-Cook材料模型参数的实验测定 总被引:19,自引:1,他引:19
介绍一种通过Hopkinson拉伸实验、圆筒爆炸试验和计算机仿真来确定Johnson-Cook材料模型中相关常数的方法. 相似文献
223.
Shuangfei Zhu Qiang Gan Nianshou Cheng Changgen Feng 《International journal of quantum chemistry》2020,120(12):e26202
In order to attain comprehensive insights into the crystallization of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) from solutions, the geometric and electronic structures and conformational transformations of its β-, γ-, ε-, ζ- and η- forms in six organic solvents (ethanol, ethyl acetate, methanol, acetone, acetonitrile, and 2-propanol) were evaluated using quantum chemistry calculations. Results showed that solvents have little effect on the geometric structures of molecules but greatly impact the energy and electronic structure of CL-20. The electron density, atomic charges, and electrostatic potential of CL-20 exhibit polarization due to the solvent effect, especially in alcohols. The polarity of CL-20 increased because of the change in electron density. The transformations of the five conformers of CL-20 were studied thoroughly, and the energy barriers were evaluated using the Gibbs energies. Importantly, the reason η-CL-20 is only found in CL-20-based cocrystals was suggested. These results indicate that solvents play a critical role in crystal growth. 相似文献
224.
225.
226.
227.
Tyrrell E Dicinoski GW Hilder EF Shellie RA Breadmore MC Pohl CA Haddad PR 《Journal of chromatography. A》2011,1218(20):3007-3012
There are many methods available to detect and positively identify either organic or inorganic explosives separately, however no one method has been developed which can detect both types of explosive species simultaneously from a single sample. In this work, a unique coupled-chromatographic system is reported for the simultaneous determination of both organic and inorganic explosive species and is used for pre-blast analysis/identification purposes. This novel approach is based on the combination of reversed-phase high performance liquid chromatography and ion chromatography which allows trace levels of organic and inorganic explosives to be determined simultaneously from a single sample. Using this procedure, a 20 min reversed-phase separation of organic explosives is coupled to a 16 min ion-exchange separation of anions present in inorganic explosives, providing a complete pre-blast analysis/identification system for the separation and detection of a complex mixture containing organic and/or inorganic explosive species. The total analysis time, including sufficient column re-equilibration between runs, was <25 min using the coupled system. By this method, the minimum resolution for the organic separation was 1.16 between nitroglycerin and tetryl and the detection limits ranged from 0.31 mg L(-1) for cyclotetramethylene tetranitramine (HMX) and 1.54 mg L(-1) for pentaerythrite tetranitrate (PETN), while the minimum resolution for the inorganic separation was 0.99 between azide and nitrate, and the detection limits ranged from 7.70 μg L(-1) for fluoride and 159.50 μg L(-1) for benzoate. 相似文献
228.
229.
V. F. Nesterenko S. A. Pershin A. N. Lazaridi S. I. Afanasenko E. V. Matizen P. I. Yefremova 《高压研究》2013,33(1-6):832-834
Abstract The results of investigating the processes of explosive compaction of Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O powdered ceramic high temperature superconducting materials and the shock-induced variation of their properties are presented. The possibility for obtaining metal-ceramic cylinder and spiral-shaped articles is illustrated. The shock wave loading of sintered ceramics is shown to result in degrading its superconducting properties up on R(T), which are subsequently restored by low-temperature annealing. The loss of superconducting properties is demonstrated to correlate with the X-ray lines width. In case of Bi-4334 ceramic, we have observed the improving SP-properties on susceptibility just after shocking it. The effect of the compaction pressure, initial particle size, atmosphere (air, O2, N2), initial temperature on material properties is studied. 相似文献
230.
本文在传统Asay窗技术基础上设计发展了一种用于诊断熔化状态下 金属样品表面附近一定厚度区域内熔化破碎现象的Asay-F窗技术, 较准确给出了该区域熔化破碎物质的质量和密度分布信息, 并与表面微喷和固体层裂片的特征进行了比对分析, 为熔化破碎现象的形成机理认识和物理建模提供了重要实验数据. 而且研究表明Asay-F窗技术可在一定程度上弥补目前熔化破碎现象 主要依靠高成本质子照相技术诊断的不足.
关键词:
爆轰加载
熔化破碎
Asay-F窗 相似文献