全文获取类型
收费全文 | 792篇 |
免费 | 31篇 |
国内免费 | 3篇 |
专业分类
化学 | 602篇 |
晶体学 | 5篇 |
力学 | 10篇 |
数学 | 37篇 |
物理学 | 172篇 |
出版年
2023年 | 7篇 |
2022年 | 6篇 |
2021年 | 24篇 |
2020年 | 21篇 |
2019年 | 21篇 |
2018年 | 23篇 |
2017年 | 12篇 |
2016年 | 31篇 |
2015年 | 20篇 |
2014年 | 24篇 |
2013年 | 41篇 |
2012年 | 49篇 |
2011年 | 77篇 |
2010年 | 27篇 |
2009年 | 31篇 |
2008年 | 47篇 |
2007年 | 41篇 |
2006年 | 63篇 |
2005年 | 48篇 |
2004年 | 35篇 |
2003年 | 32篇 |
2002年 | 29篇 |
2001年 | 9篇 |
2000年 | 17篇 |
1999年 | 2篇 |
1998年 | 9篇 |
1997年 | 10篇 |
1996年 | 8篇 |
1995年 | 2篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1969年 | 2篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有826条查询结果,搜索用时 46 毫秒
101.
Potential Analysis - In the present paper, we consider long time behaviors of the volume of the Wiener sausage on Dirichlet spaces. We focus on the volume of the Wiener sausage for diffusion... 相似文献
102.
Kazuki Yoshida 《Journal of Mathematical Analysis and Applications》2010,369(2):645-657
We consider an inverse acoustic scattering problem for identifying a non-convex penetrable obstacle in three dimensions in a homogeneous medium. We apply the complex geometrical optics solutions with logarithmic phase, which is called complex spherical waves, to reconstruction problem. The reconstruction schemes will be demonstrated in the last section. 相似文献
103.
M. K. Kabir S. Kawata K. Adachi H. Tobita N. Miyazaki H. Kumagai 《Molecular Crystals and Liquid Crystals》2013,570(2):491-496
Abstract Hydrogen bond supported new iron-chloranilate assemblies, {(Hpy)[Fe(CA)2(H2O)2](H2O)}n (py = pyridine, H2CA = chloranilic acid, C6H2O4Cl2) (1), and [(phz)2[Fe(CA)2(H2O)2](H2O)2]n (phz = phenazine, C12H8N2) (2) have been synthesized and characterized. Compound 2 crystallizes in the monoclinic, space group C2/m (#12), with a= 29.135(6) Å, b= 16.886(6) Å, c = 15.017(5) Å, ß = 165.907(1)°, V= 1798(2) Å3, Z = 2. In both the compounds two chloranilate dianions and two water molecules are coordinated to the iron ion making anionic monomers [Fe(CA)2(H2O)2]?, which are the building blocks of the compounds. The coordination environment around the iron ion in the building block is a distorted octahedron, where two water molecules sit on the trans position to each other. [Fe(CA)2(H2O)2]? anions form common layer structures, supported by hydrogen bonds. Hpy+ are intercalated in between the layers of 1 by electrostatic and hydrogen bonding interactions and phz are intercalated in that of 2 by electrostatic interactions. DSC traces of 1 show anomaly at 174 K, indicating phase transition in the compound. 相似文献
104.
A nickel-catalyzed [2 + 2] cycloaddition of bisallenes has been described. Simple bisallenes are employed for the formation of “head to head” cycloadducts in the presence of Ni(0) with xantphos. The dienyl moiety in a product were applicable for various [4 + 2] cycloaddition reactions. Allene-allenamides under Ni-xantphos system gave the tricyclic compounds through sequential [2 + 2]–[4 + 2] cycloaddition reaction in highly stereoselective manner. 相似文献
105.
Yosuke Hara Kazuyoshi Kanamori Kazuki Nakanishi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(52):19223-19229
We present a two‐step template‐free approach toward monolithic materials with controlled trimodal porous structures with macro‐, meso‐, and micropores. Our method relies on two ordering processes in discrete length scales: 1) Spontaneous formation of macroporous structures in monolithic materials by the sol–gel process through the short‐range ordered self‐assembly of metal–organic frameworks (MOFs), and 2) reorganization of the framework structures in a mediator solution. The Zr‐terephthalate‐based MOF (UiO‐66‐NH2) was adopted as a proof of concept. The self‐assembly‐induced phase separation process offered interconnected macropores with diameters ranging from 0.9 to 1.8 μm. The subsequent reorganization process converted the microporous structure from low crystalline framework to crystalline UiO‐66. The resultant mesopore size within the skeletons was controlled in the range from 9 to 21 nm. This approach provides a novel way of designing spaces from nano‐ to micrometer scale in network‐forming materials. 相似文献
106.
Kazuki Hasebe 《Physics letters. A》2008,372(9):1516-1520
Based on the recently proposed SUSY quantum Hall effect, we show that Laughlin and Moore-Read states are related by a hidden SUSY transformation. Regarding the SUSY Laughlin wavefunction as a master wavefunction, Laughlin and Moore-Read states appear as two extreme limits of component wavefunctions. Realizations of topological excitations on Laughlin and Moore-Read states are also discussed in the SUSY formalism. We develop a stereographically projected formulation of the SUSY quantum Hall effect. With appropriate interpretation of Grassmann odd coordinates, we illustrate striking analogies between SUSY quantum Hall effect and superfluidity. 相似文献
107.
N. Takeyasu T. Tanaka S. Kawata 《Applied Physics A: Materials Science & Processing》2008,90(2):205-209
Three-dimensional silver/polymer conjugated microstructures were fabricated by site-selective metal deposition on photopolymer
structures in the sub-micrometer scale. Photopolymerizable resins with and without an amide group were independently prepared,
and a three-dimensional polymer structure was fabricated with those resins by means of the two-photon-induced photopolymerization
technique to confine the photopolymerization to a sub-micrometer volume. Silver was selectively deposited on the surface of
the amide-containing polymer parts by electroless plating. This method can provide 3D arbitrary silver/polymer composite microstructures
with sub-micrometer resolution.
PACS 81.07-b; 81.16-c; 81.07.Pr 相似文献
108.
Alvarado Tarun Norihiko Hayazawa Taka‐Aki Yano Satoshi Kawata 《Journal of Raman spectroscopy : JRS》2011,42(5):992-997
We demonstrate tip‐heating‐assisted enhanced Raman spectroscopy to investigate the temperature dependence of the carbon nanotube G‐band with nanoscale resolution. The controllable and nanoscale heat generated at the tip apex was used to thermally perturb and characterize a small volume in a carbon nanotube sample that is precisely positioned underneath the tip. The dependence of tip enhancement with temperature was also experimentally examined, which is in good agreement with the enhancement calculated from the electromagnetic model of isolated spheroids. The technique presented may open up opportunities in the study of controlled heat‐assisted biochemical reactions and physical transformations of nanostructures. It can also be used for thermal characterization of various materials requiring site‐selective and controllable nanoscale heat source and could enable the realization of new photothermal devices. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
109.
Kazuki Komatsu Stefan Klotz Satoshi Nakano Shinichi Machida Takanori Hattori Asami Sano-Furukawa 《高压研究》2020,40(1):184-193
ABSTRACTA new high pressure cell for neutron diffraction experiments using nano-polycrystalline anvils is presented. The cell design, off-line pressure generation tests and a gas-loading procedure for this cell are described. The performance is illustrated by powder neutron diffraction patterns of ice VII to ~82?GPa. We also demonstrate the feasibility of single crystal neutron diffraction experiments of Fe3O4 at ambient conditions using this cell and discuss the current limitation and future developments. 相似文献
110.