首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   8152篇
  免费   1308篇
  国内免费   771篇
化学   5707篇
晶体学   114篇
力学   493篇
综合类   77篇
数学   830篇
物理学   3010篇
  2024年   9篇
  2023年   179篇
  2022年   178篇
  2021年   255篇
  2020年   385篇
  2019年   354篇
  2018年   306篇
  2017年   255篇
  2016年   431篇
  2015年   400篇
  2014年   548篇
  2013年   623篇
  2012年   691篇
  2011年   747篇
  2010年   486篇
  2009年   410篇
  2008年   520篇
  2007年   452篇
  2006年   402篇
  2005年   329篇
  2004年   223篇
  2003年   212篇
  2002年   157篇
  2001年   119篇
  2000年   140篇
  1999年   150篇
  1998年   129篇
  1997年   131篇
  1996年   155篇
  1995年   110篇
  1994年   105篇
  1993年   92篇
  1992年   77篇
  1991年   68篇
  1990年   71篇
  1989年   47篇
  1988年   50篇
  1987年   35篇
  1986年   33篇
  1985年   26篇
  1984年   22篇
  1983年   15篇
  1982年   18篇
  1981年   15篇
  1980年   11篇
  1979年   7篇
  1975年   5篇
  1974年   5篇
  1970年   12篇
  1937年   5篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
We experimentally analyze the heat capacity and thermal expansion of reference solids in a wide temperature range from several Kelvin to melting temperature,and establish a universal double-linear relation between the experimental heat capacity Cp and thermal expansion β,which is different from the previous models.The universal behavior between heat capacity and thermal expansion is important to predict the thermodynamic parameters at constant pressure,and is helpful for understanding the nature of thermal properties in solids.  相似文献   
2.
Li  Jiashen  Pan  Yun 《Russian Physics Journal》2022,64(9):1715-1723
Russian Physics Journal - The improvement of chip integration leads to the increase of power density of system chips, which leads to the overheating of system chips. When dispatching the power...  相似文献   
3.
Journal of Radioanalytical and Nuclear Chemistry - The preparation of C30 concrete for a cavernous waste repository under construction in China and its Cs(I) adsorption performance were...  相似文献   
4.
The design and exploration of efficient, stable and environmentally compatible organic emitters for an electrochemiluminescence (ECL) sensor is a promising topic. Herein, a novel environmentally-friendly luminophore, ZnBCBTP@MWCNTs, were fabricated via self-assembly of porphyrin molecules (ZnBCBTP) onto multi-walled carbon nanotubes (MWCNTs). The resulting luminophore ZnBCBTP@MWCNTs displayed not only the highly ECL property and but also the good accelerated electron mobility. Then, a label-free ECL biosensor based ZnBCBTP@MWCNTs was constructed for the ultrasensitive detection of uric acid. Excitingly, this proposed ECL biosensor performed a good linear relationship in the range of 0–300 μM with a low detection limit of 1.4 μM, thus offering another reliable and feasible sensing platform for clinical bioanalysis with good selectivity, stability, and repeatability.  相似文献   
5.
Molecular Diversity - According to the fact that 5-nitro-3-trinitromethyl-1H-1,2,4 triazole (NTNMT) is a successful, good explosive, energetic groups such as –CH3, –NH2, –NHNO2,...  相似文献   
6.
Ding  Hao  Wang  Jin-Ting  Lu  Li-Qiao  Pan  Jian-Wen 《Nonlinear dynamics》2021,104(4):3365-3384
Nonlinear Dynamics - Conventional tuned liquid column dampers (TLCDs) are deficient in multidirectionality. In contrast, toroidal TLCDs are designed to extend the application to multidirectional...  相似文献   
7.
Acta Mathematicae Applicatae Sinica, English Series - This paper proposes a method for modelling volatilities (conditional covariance matrices) of high dimensional dynamic data. We combine the...  相似文献   
8.
9.
A fluorescent monolayered two-dimensional polymer (2DP) containing both tetraphenylethylene (TPE) and imine linkages is synthesized at air-water interface using the Langmuir-Blodgett method. We designed TPE-based monomers with long distances between the TPE and the imine linkages to avoid the charge transfer and therefore keep the fluorescence. A monolayered 2DP provided with more than 104 μm2 in domain size and around 0.8 nm thickness was obtained through a successive Schiff base reaction at air-water interface. The nanostructures and fluorescent property of 2DP films were characterized by optical microscopy, SEM, TEM, AFM and fluorescence spectrum. Most importantly, the tip-enhanced Raman spectroscopy (TERS) was utilized here to confirm the success of the polycondensation of monolayered 2DP.  相似文献   
10.
Systematic design and self-assembly of metal–organic polyhedra with predictable configurations has been a long-standing challenge in crystal engineering. Herein a concave polyoxovanadate cluster, [V6O6(OCH3)9(SO4)4]5−, which can be generated in situ under specific reaction conditions, is reported. Based on this cluster, a potential trivalent molecular building block, [V6O6(OCH3)9(SO4)(CO2)3]2−, can be obtained by the bridging-ligand-substitution strategy and it possesses appropriate angle information for the design of molecular cubes. Utilizing the face-directed assembly of the trivalent molecular building block and a diverse set of tetratopic carboxylate linkers, a series of metal–organic cubes ( VMOC-1 – VMOC-5 ) with the same topology but different functionalities and dimensions were designed and constructed. An inclusion study using VMOC-3 shows that they are potential molecular receptors for selective capture of size-matching polycyclic aromatic hydrocarbon guest molecules.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号