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   120篇
  免费   5篇
  国内免费   12篇
化学   66篇
晶体学   3篇
力学   31篇
数学   12篇
物理学   25篇
  2023年   3篇
  2022年   6篇
  2021年   4篇
  2020年   8篇
  2019年   3篇
  2018年   7篇
  2017年   4篇
  2016年   7篇
  2015年   7篇
  2014年   6篇
  2013年   6篇
  2012年   6篇
  2011年   13篇
  2010年   3篇
  2009年   5篇
  2008年   4篇
  2007年   4篇
  2006年   3篇
  2003年   1篇
  2002年   1篇
  2001年   3篇
  2000年   9篇
  1999年   10篇
  1998年   8篇
  1997年   1篇
  1996年   2篇
  1990年   2篇
  1984年   1篇
排序方式: 共有137条查询结果,搜索用时 15 毫秒
1.
以氧化石墨烯(GO)为原料, 利用温和方法制备了3种不同还原程度的部分还原氧化石墨烯pRGO1, pRGO2和pRGO3(pRGO1—3); 利用傅里叶变换红外光谱(FTIR)、 拉曼光谱(Raman)、 X 射线光电子能谱(XPS)、 紫外-可见光谱(UV-Vis)、 透射电子显微镜(TEM)和 EDS能谱对其结构和形貌进行了表征. 细胞实验结果表明, 无激光照射下pRGO1—3本身的细胞毒性较低; 近红外(NIR)激光照射下pRGO1—3通过光热和光毒性双重作用杀伤肿瘤细胞. 实验结果显示了pRGO 在肿瘤光热疗法和光动力疗法领域的应用潜力.  相似文献   
2.
针对传统实验那种安排过死、刻板机械的特点,把设计性实验运用于教具设计与制作课程之中,充分地培养了学生动手、动脑的综合能力。  相似文献   
3.
4.
Triazole-based deubiquitylase (DUB)-resistant ubiquitin (Ub) probes have recently emerged as effective tools for the discovery of Ub chain-specific interactors in proteomic studies, but their structural diversity is limited. A new family of DUB-resistant Ub probes is reported based on isopeptide-N-ethylated dimeric or polymeric Ub chains, which can be efficiently prepared by a one-pot, ubiquitin-activating enzyme (E1)-catalyzed condensation reaction of recombinant Ub precursors to give various homotypic and even branched Ub probes at multi-milligram scale. Proteomic studies using label-free quantitative (LFQ) MS indicated that the isopeptide-N-ethylated Ub probes may complement the triazole-based probes in the study of Ub interactome. Our study highlights the utility of modern protein synthetic chemistry to develop structurally and new families of tool molecules needed for proteomic studies.  相似文献   
5.
Journal of Solid State Electrochemistry - Ionic conductivity is an important separator parameter influencing the cycle life and rate capability of lithium-ion batteries (LIBs). To improve the ionic...  相似文献   
6.
7.
A rapid, sensitive, and selective method using a quick, easy, cheap, effective, rugged, and safe procedure in combination with high-performance liquid chromatography and tandem mass spectrometry was developed for the analysis of fenaminstrobin in peanut and soil. The average recoveries in all samples fall within 88.1%–10%, having relative standard deviations of 2.5%–14%. The limits of quantitation of fenaminstrobin in peanut shell, peanut kernels, peanut plant, and soil were 0.005, 0.004, 0.01, and 0.002 mg kg?1, respectively. The field trial results show that the half-lives of fenaminstrobin in peanut plant and soil are 1.3–10 and 5.5–20 days, respectively. Residues in peanut kernels were found to be present at <0.004 mg kg?1 levels, based on good agricultural practices recommended by the manufacturer. The risk posed by fenaminstrobin exposure at the recommended dosage is negligible to humans, depending on the risk quotient.  相似文献   
8.
Cladding-ring-equivalent effective index method (CREEIM) is proposed to analyze the propagation characteristics in the multi-cladding photonic crystal fibers (MCPCFs). The effective indices and dispersions of the step index two and three-cladding structures are calculated with the Sellmeier formula. The accuracy of CREEIM is competitive to the results calculated by the multipole method (MPM). With different structure parameters, the differences between two methods are evaluated with the relative error RE of effective index and relative difference RD of dispersion. This method is also used to analyze the mode cut-off and nonlinear characteristics in the three-cladding structure PCFs by calculating the mode effective index neff instead of complex mode field distribution.  相似文献   
9.
Trees with Cantor Eigenvalue Distribution   总被引:2,自引:0,他引:2  
Li  He  Xiangwei  Liu    Gilbert  Strang 《Studies in Applied Mathematics》2003,110(2):123-138
We study a family of trees with degree k at all interior nodes and degree 1 at boundary nodes. The eigenvalues of the adjacency matrix have high multiplicities. As the trees grow, the graphs of those eigenvalues approach a piecewise-constant "Cantor function." For each value of     , we will find the fraction of the eigenvalues that are given by     .  相似文献   
10.
光的衍射法测量金属的线胀系数   总被引:2,自引:0,他引:2  
给出测量金属线胀系数的一种新方法.利用光的衍射法可以较精确地测量长度变化这一特点,对黄铜的线胀系数进行了测量.  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