全文获取类型
收费全文 | 1176篇 |
免费 | 37篇 |
国内免费 | 5篇 |
专业分类
化学 | 930篇 |
晶体学 | 6篇 |
力学 | 8篇 |
数学 | 57篇 |
物理学 | 217篇 |
出版年
2023年 | 8篇 |
2022年 | 19篇 |
2021年 | 29篇 |
2020年 | 24篇 |
2019年 | 22篇 |
2018年 | 30篇 |
2017年 | 13篇 |
2016年 | 39篇 |
2015年 | 24篇 |
2014年 | 29篇 |
2013年 | 58篇 |
2012年 | 59篇 |
2011年 | 84篇 |
2010年 | 33篇 |
2009年 | 35篇 |
2008年 | 66篇 |
2007年 | 49篇 |
2006年 | 61篇 |
2005年 | 72篇 |
2004年 | 54篇 |
2003年 | 53篇 |
2002年 | 56篇 |
2001年 | 23篇 |
2000年 | 35篇 |
1999年 | 15篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 7篇 |
1995年 | 9篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 19篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 19篇 |
1984年 | 13篇 |
1983年 | 10篇 |
1982年 | 9篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1975年 | 3篇 |
1973年 | 3篇 |
1970年 | 3篇 |
1968年 | 4篇 |
排序方式: 共有1218条查询结果,搜索用时 8 毫秒
101.
Dr. Yuki Ohishi Kentaro Masuda Kazuki Kudo Prof. Dr. Hajime Abe Prof. Dr. Masahiko Inouye 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(2):785-793
Generally, cage-shaped hosts for saccharides can bind strongly to guest molecules because of the three-dimensional preorganized hydrogen-bonding sites. However, the preparation of cage molecules is often difficult because of the low yield of the macrocyclization step. Here, we report a three-arm-shaped molecule possessing pyridine-acetylene-phenol units as a new kind of host having a preorganized three-dimensional hydrogen-bonding site. This three-arm-shaped host was readily prepared compared to a cage-shaped analogue. This host associated with lipophilic glycosides to form chiral complexes, and the association constants were sufficiently high as to be comparable to those of the cage-shaped analogue. Furthermore, this host extracted native monosaccharides into a lipophilic solvent. 相似文献
102.
Hiroyuki Higuchi Kazuhiro Takatsu Tetsuo Otsubo Yoshiteru Sakata Soichi Misumi 《Tetrahedron letters》1982,23(6):671-672
A novel cage compound was obtained by irradiation of a quadruple-layered dithiacyclophane and showed thermally reverse reaction. 相似文献
103.
Corrugated paper is produced by gluing three types of papers of the same breadth. Given a set of orders, we first assign each order to one of the standard breadths, and then sequence those assigned to each standard breadth so that they are continuously manufactured from the three rolls of the specified standard breadth equipped in the machine called corrugator. Here we are asked to achieve multi-goals of minimizing total length of roll papers, total loss of papers caused by the differences between standard breadths and real breadths of the orders, and the number of machine stops needed during production. We use integer programming to assign orders to standard breadths, and then develop a special purpose algorithm to sequence the orders assigned to each standard breadth. This is a first attempt to handle scheduling problems of the corrugator machine. 相似文献
104.
Kazuki Aoki Nakao Hayashi Pavel I. Naumkin 《NoDEA : Nonlinear Differential Equations and Applications》2016,23(6):65
We consider the Cauchy problem for the fourth-order nonlinear Schrödinger equation where \(n=1,2\). We prove global existence of small solutions under the growth condition of \(f\left( u\right) \) satisfying \(\left| \partial _{u}^{j}f\left( u\right) \right| \le C\left| u\right| ^{p-j},\) where \(p>1+\frac{4}{n},0\le j\le 3\).
相似文献
105.
106.
Journal of Theoretical Probability - We consider the range of the simple random walk on graphs with spectral dimension two. We give a form of strong law of large numbers under a certain uniform... 相似文献
107.
AbstractIn this paper, we study different classes of generalized convex/quasiconvex set-valued maps, defined by means of the l-type and u-type preorder relations, currently used in set-valued optimization. In particular, we identify those classes of set-valued maps for which it is possible to extend the classical characterization of convex real-valued functions by quasiconvexity of their affine perturbations. 相似文献
108.
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
109.
This paper reports the successful operation of a 70 MHz driving surface acoustic wave (SAW) linear motor with a miniaturized stator transducer. This paper also deals with an investigation into an optimized slider design for the miniaturized SAW linear motor. The performance of three silicon type sliders, with different projection size, was compared. Output forces of the three sliders were measured with change of pre-load. It was found that the slider with smaller projection tended to produce greater output force. 相似文献
110.
T. Okada F. Yahiro H. Uetsuhara Y. Nakata M. Maeda S. Higuchi K. Ueda 《Applied Physics A: Materials Science & Processing》1999,69(7):S723-S726
We describe the deposition and characterization of Bi12SiO20 (bismuth silicon oxide; BSO) thin films on Y-stabilized zirconia (YSZ) and SiO2 glass substrates by pulsed-laser deposition (PLD) for the application of an electric field sensor. It was found that all films deposited on YSZ substrates heated at 400 °C and more were crystallized and the (310) plane was perpendicular to the substrate normal. The highly (310) oriented crystallized films were even deposited on SiO2 glass substrates, and this will make it possible to grow the crystallized films on the end surface of a SiO2 glass fiber. 相似文献