全文获取类型
收费全文 | 465篇 |
免费 | 10篇 |
国内免费 | 3篇 |
专业分类
化学 | 290篇 |
力学 | 8篇 |
数学 | 104篇 |
物理学 | 76篇 |
出版年
2021年 | 3篇 |
2020年 | 7篇 |
2019年 | 11篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 8篇 |
2015年 | 11篇 |
2014年 | 12篇 |
2013年 | 32篇 |
2012年 | 24篇 |
2011年 | 14篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 27篇 |
2007年 | 27篇 |
2006年 | 27篇 |
2005年 | 14篇 |
2004年 | 18篇 |
2003年 | 14篇 |
2002年 | 14篇 |
2001年 | 10篇 |
2000年 | 16篇 |
1999年 | 13篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1992年 | 5篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1970年 | 11篇 |
1966年 | 4篇 |
1959年 | 3篇 |
1943年 | 2篇 |
1934年 | 2篇 |
1933年 | 3篇 |
1930年 | 2篇 |
排序方式: 共有478条查询结果,搜索用时 15 毫秒
81.
Gunther Mair Hans Georg von Schnering Michael Wrle Reinhard Nesper 《无机化学与普通化学杂志》1999,625(7):1207-1211
Li2B6 is formed from the elements as transparent red microcrystalline compound (Li : B = 1 : 3; Mo crucible in closed Nb ampoule; 1723 K; 4 h). Single crystals are grown from a lithium silicide melt with large Li excess at 1923 K. Li2B6 is a semiconductor with electron as well as Li+ ionic conductivity which dominates above 600 K. Microcrystalline samples react with H2O liberating gases and forming a brownish amorphous product, but larger crystals are not very sensitive. – Li2B6 crystallizes tetragonally in a new tP16 structure type which is a variant of the CaB6 structure (a = 5.975 Å, c = 4.189 Å; Z = 2; space group P4/mbm). The [B62–] net of the polymeric octahedro-anion is slightly distorted to give space for the insertion of a (32434) net of the Li+ cations in the cavities (d(B–B)endo = 1.766 Å; d(B–B)exo = 1.720 Å; d(Li–B) = 2.363 Å; d(Li–Li) = 3.094 Å). The incomplete occupancy of the Li position (80%) and the electron density at a further position (20%) indicate the mobility of the Li+ cations. 相似文献
82.
83.
Gunther Lock 《Monatshefte für Chemie / Chemical Monthly》1959,90(5):680-682
Zusammenfassung Aus 2,4-Difluortoluol wurden nach üblichen Methoden 2,4-Difluorbenzaldehyd und 2,4-Difluorzimtsäure hergestellt. 相似文献
84.
Artyukhova N. V. Kaftanarova M. I. Anikeev S. G. Khodorenko V. N. Garin A. S. Monogenov A. N. Gunther V. É. 《Russian Physics Journal》2019,62(3):527-533
Russian Physics Journal - An investigation of the influence of reaction- and diffusion-induced interactions in the system of PV-N55Т45 TiNi-based powders and activating Co and Ni additions... 相似文献
85.
Nijhuis CA Sinha JK Wittstock G Huskens J Ravoo BJ Reinhoudt DN 《Langmuir : the ACS journal of surfaces and colloids》2006,22(23):9770-9775
Redox-active ferrocenyl (Fc)-functionalized poly(propylenimine) (PPI) dendrimers solubilized in aqueous media by complexation of the Fc end groups with beta-cyclodextrin (betaCD) were immobilized at monolayers of betaCD on glass ("molecular printboards") via multiple host-guest interactions. The directed immobilization of the third-generation dendrimer-betaCD assembly G3-PPI-(Fc)16-(betaCD)16 at the printboard was achieved by supramolecular microcontact printing. The redox activity of the patterned dendrimers was mapped by scanning electrochemical microscopy (SECM) in the positive feedback mode using [IrCl(6)](3-) as a mediator. Local oxidation of the Fc-dendrimers by the microelectrode-generated [IrCl(6)](2-) resulted in an effective removal of the Fc-dendrimers from the host surface since the oxidation of Fc to the oxidized form (Fc+) leads to a concomitant loss of affinity for betaCD. Thus, SECM provided a way not only to image the surface, but also to control the binding of the Fc-terminated dendrimers at the molecular printboard. Additionally, the electrochemical desorption process could be monitored in time as the dendrimer patterns were gradually erased upon multiple scans. 相似文献
86.
Proteomics in cancer research: methods and application of array-based protein profiling technologies
Hoeben A Landuyt B Botrus G De Boeck G Guetens G Highly M van Oosterom AT de Bruijn EA 《Analytica chimica acta》2006,564(1):19-33
With the human genome sequence now determined, the field of molecular medicine is moving beyond genomics to proteomics, the large-scale analysis of proteins.It is now possible to examine the expression of more than 1000 proteins using mass spectrometry technology coupled with various separation methods.Microarray technology is a new and efficient approach, for extracting relevant biomedical data and has a wide range of applications. It provides a versatile tool to study protein-protein, protein-nucleic acid, protein-lipid, enzyme-substrate and protein-drug interactions.This review paper will explore the key themes in proteomics and their application in clinical cancer research. 相似文献
87.
88.
Gabriel P. Paternain Mikko Salo Gunther Uhlmann 《Geometric And Functional Analysis》2012,22(5):1460-1489
We show that for a simple surface with boundary the attenuated ray transform in the presence of a unitary connection and a skew-Hermitian Higgs field is injective modulo the natural obstruction for functions and vector fields. We also show that the connection and the Higgs field are uniquely determined by the scattering relation modulo a gauge transformation. The proofs involve a Pestov type energy identity for connections together with holomorphic gauge transformations which arrange the curvature of the connection to have definite sign. 相似文献
89.
90.
Gunther Schmidt 《Numerische Mathematik》1986,50(3):337-352
Summary This paper analyses the convergence of spline collocation methods for singular integro-differential equations over the interval (0.1). As trial functions we utilize smooth polynomial splines the degree of which coincides with the order of the equation. Depending on the choice of collocation points we obtain sufficient and even necessary conditions for the convergence in sobolev norms. We give asymptotic error estimates and some numerical results. 相似文献