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   176篇
  免费   5篇
  国内免费   1篇
化学   114篇
晶体学   2篇
力学   2篇
数学   44篇
物理学   20篇
  2024年   1篇
  2022年   2篇
  2021年   7篇
  2020年   5篇
  2019年   6篇
  2018年   5篇
  2017年   3篇
  2016年   11篇
  2015年   4篇
  2014年   8篇
  2013年   12篇
  2012年   8篇
  2011年   19篇
  2010年   4篇
  2009年   6篇
  2008年   9篇
  2007年   10篇
  2006年   11篇
  2005年   10篇
  2004年   5篇
  2003年   9篇
  2002年   3篇
  2001年   3篇
  1999年   2篇
  1998年   1篇
  1997年   3篇
  1996年   3篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1991年   1篇
  1983年   1篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1975年   2篇
  1974年   1篇
排序方式: 共有182条查询结果,搜索用时 578 毫秒
31.
A local tuning of the modes of photonic crystal systems both to blue and to red sides of the resonance is implemented by nano-infiltration/evaporation of water and laser micro-oxidation. This technology is used to completely control coupled photonic nanocavities (photonic crystal molecules). Beside the standard condition of zero detuning between identical modes of the two cavities (homoatomic molecule), we are also able to produce coupling between two modes of different polarization and spatial distribution (heteroatomic molecule).  相似文献   
32.
Annamaria Barbagallo 《PAMM》2007,7(1):2060035-2060036
In this paper we consider the dynamic spatial price equilibrium problem and the associated evolutionary variational inequality. In particular the regularity of equilibrium solutions is studied and a method for solving the dynamic spatial price equilibrium problem is presented. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
33.
34.
The paraffin oil dispersion technique innovated in the recent years to synthesize bulk polymer nanocomposite materials has a uniform dispersion. This research work aims to study the effect of added carbon nanotubes (CNTs) on flexural, impact and rheology behaviors of polyoxymethylene (POM) reinforced by 0–0.03 wt% of CNT using paraffin oil dispersion technique. The wettability and lamellar thickness were measured and rheological performance investigated using a parallel plate rheometer. The flexural and impact mechanical properties were also evaluated. The fracture surfaces were then examined by microscopy. The results showed that the energy to break, flexural strength and modulus increased proportionally with the addition of the amount of CNT in the matrix. For the rheology behavior, the viscosity decreased at the low percentage of CNT and then increased with increase in the percentage weight ratio of CNT in the POM matrix. It was also noted that the water contact angle rose with the increase the CNT percentages. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
35.
Set-Valued and Variational Analysis -  相似文献   
36.
We introduce a new numerical approach for solving Volterra integral equations of the second kind when the kernel contains a mild singularity. We give a convergence result. We also present numerical examples which show the performance and efficiency of our method.

  相似文献   

37.
The chaperonin of the hyperthermophilic archaeonSulfolobus solfataricus, briefly Ssocpn, was purified by a fast and high-yield procedure. Ssocpn, a 920 kDa-complex of two different subunits, displays a potassium-dependent ATPase activity with a temperature optimum at 80°C. The ability of Ssocpn to function in vitro was investigated using different protein substrates. Ssocpn promotes correct refolding of thermophilic and mesophilic enzymes from their chemically unfolded state; moreover, Ssocpn prevents the irreversible inactivation of native proteins by suppressing their precipitation upon heating. Both the activity in assisting refolding of unfolded proteins and that in preventing heat denaturation of native proteins require the hydrolysis of ATP. The chaperone-based strategies in different technological fields are discussed, and the advantages in using archaeal chaperonins are underlined.  相似文献   
38.
The title compound was synthesized by CS2 insertion in the C-M bonds of the corresponding AgLi ate organomental compound. It contains flattened tetrahedral Ag4 units, connected in polymeric chains by intermolecular Ag...S interactions. Two Ag atoms and three S atoms are in a distorted square pyramidal arrangement around each silver atom. The crystals are tetragonal, space group 141/a witha=23.706(2) andc=12.934(2) Å. The structure was refined toR=0.032 for 889 reflections.  相似文献   
39.
(η-C5H5)(CO)2W[(η3-C5H5)(C5H5)2], I, containing two tilted five-membered rings, is converted into the bridged ferrocene derivative (η-C5H5)(CO)2W{(η3-C5H5)}[(η-C5 H4)2Fe]} II by successive reaction with Na and FeCl2.  相似文献   
40.
Alkoxydienyl- and alkoxystyrylboronates were used for Pd-catalyzed cross-coupling reactions with lactam-derived vinyl triflates. The hydrolysis of the coupling products with alkoxystyrylboronates provided the corresponding alpha-acyl-substituted 3,4-dihydro-(2H)-pyridines and 2,3,4,5-tetrahydroazepines in good to high yields. The hydrolysis of the coupling products with alkoxydienylboronates, performed in the presence of Amberlyst 15, resulted in a Nazarov-type cyclization that afforded hexahydro[1]pyrindin-7-ones and 3,4,5,6,7,8-hexahydro-(2H)-cyclopenta[b]azepin-8-ones. This methodology represents a novel and efficient procedure for the preparation of these classes of azacyclic compounds.  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