全文获取类型
收费全文 | 67817篇 |
免费 | 1027篇 |
国内免费 | 337篇 |
专业分类
化学 | 33125篇 |
晶体学 | 1110篇 |
力学 | 3487篇 |
综合类 | 8篇 |
数学 | 6322篇 |
物理学 | 25129篇 |
出版年
2022年 | 501篇 |
2021年 | 565篇 |
2020年 | 539篇 |
2019年 | 503篇 |
2018年 | 639篇 |
2017年 | 560篇 |
2016年 | 1033篇 |
2015年 | 768篇 |
2014年 | 1140篇 |
2013年 | 3009篇 |
2012年 | 2699篇 |
2011年 | 3482篇 |
2010年 | 2385篇 |
2009年 | 2411篇 |
2008年 | 3217篇 |
2007年 | 3026篇 |
2006年 | 2888篇 |
2005年 | 2599篇 |
2004年 | 2316篇 |
2003年 | 2074篇 |
2002年 | 1996篇 |
2001年 | 3146篇 |
2000年 | 2281篇 |
1999年 | 1653篇 |
1998年 | 1174篇 |
1997年 | 1173篇 |
1996年 | 1031篇 |
1995年 | 870篇 |
1994年 | 807篇 |
1993年 | 731篇 |
1992年 | 1062篇 |
1991年 | 1047篇 |
1990年 | 947篇 |
1989年 | 830篇 |
1988年 | 825篇 |
1987年 | 888篇 |
1986年 | 725篇 |
1985年 | 1033篇 |
1984年 | 973篇 |
1983年 | 688篇 |
1982年 | 695篇 |
1981年 | 682篇 |
1980年 | 641篇 |
1979年 | 744篇 |
1978年 | 781篇 |
1977年 | 786篇 |
1976年 | 691篇 |
1975年 | 585篇 |
1974年 | 626篇 |
1973年 | 553篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Mazurenko V. V. Kvashnin Y. O. Lichtenstein A. I. Katsnelson M. I. 《Journal of Experimental and Theoretical Physics》2021,132(4):506-516
Journal of Experimental and Theoretical Physics - Dzyaloshinskii–Moriya interaction, DMI in short, represents an antisymmetric type of magnetic interactions that favor orthogonal orientation... 相似文献
2.
3.
Kinetics and Catalysis - The catalytic properties of a nickel phosphide catalyst supported on silica gel in the reductive amination of carbonyl compounds were studied in a flow reactor using... 相似文献
4.
Yang T. L. Kao C. L. Kuo C. E. Yeh H. C. Li W. J. Li H. T. Chen C. Y. 《Chemistry of Natural Compounds》2022,58(5):825-827
Chemistry of Natural Compounds - A novel bibenzyl derivative, hydrangchinenin (1), was isolated from the stems of Hydrangea chinensis Maxim. (Hydrangeaceae). Its structure was determined on the... 相似文献
5.
Kobayashi M. Zhang Y. Ishikawa H. Sun J. Oddershede J. Juul Jensen D. Miura H. 《Experimental Mechanics》2021,61(5):817-828
Experimental Mechanics - The internal strain distribution developing during plastic deformation is important for understanding the mechanical properties of polycrystalline materials. Such... 相似文献
6.
7.
Li Y. Shi W. H. Dong L. M. Xu S. X. Huang H. J. Yin J. R. 《Journal of Applied Spectroscopy》2022,89(3):534-541
Journal of Applied Spectroscopy - Sr3B2O6:Dy3+, Eu3+ single-matrix white-light-emitting materials are prepared using the high-temperature solid-state method. The microstructure, emission spectrum,... 相似文献
8.
Physics of Atomic Nuclei - We have investigated the robustness of the spin-navigator based method for manipulating the beam polarization to bend magnet installation errors. Toward that end,... 相似文献
9.
Dr. Yulia Y. Enakieva Dr. Anna A. Sinelshchikova Prof. Mikhail S. Grigoriev Prof. Vladimir V. Chernyshev Dr. Konstantin A. Kovalenko Prof. Irina A. Stenina Prof. Andrey B. Yaroslavtsev Prof. Yulia G. Gorbunova Prof. Aslan Y. Tsivadze 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(45):10552-10556
The design of new solid-state proton-conducting materials is a great challenge for chemistry and materials science. Herein, a new anionic porphyrinylphosphonate-based MOF ( IPCE-1Ni ), which involves dimethylammonium (DMA) cations for charge compensation, is reported. As a result of its unique structure, IPCE-1Ni exhibits one of the highest value of the proton conductivity among reported proton-conducting MOF materials based on porphyrins (1.55×10−3 S cm−1 at 75 °C and 80 % relative humidity). 相似文献
10.
Profiling engineered data with robust mining methods continues attracting attention in knowledge engineering systems. The purpose of this article is to propose a simple technique that deals with non-linear multi-factorial multi-characteristic screening suitable for knowledge discovery studies. The method is designed to proactively seek and quantify significant information content in engineered mini-datasets. This is achieved by deploying replicated fractional-factorial sampling schemes. Compiled multi-response data are converted to a single master-response effectuated by a series of distribution-free transformations and multi-compressed data fusions. The resulting amalgamated master response is deciphered by non-linear multi-factorial stealth stochastics intended for saturated schemes. The stealth properties of our method target processing datasets which might be overwhelmed by a lack of knowledge about the nature of reference distributions at play. Stealth features are triggered to overcome restrictions regarding the data normality conformance, the effect sparsity assumption and the inherent collapse of the ‘unexplainable error’ connotation in saturated arrays. The technique is showcased by profiling four ordinary controlling factors that influence webpage content performance by collecting data from a commercial browser monitoring service on a large scale web host. The examined effects are: (1) the number of Cascading Style Sheets files, (2) the number of JavaScript files, (3) the number of Image files, and (4) the Domain Name System Aliasing. The webpage performance level was screened against three popular characteristics: (1) the time to first visual, (2) the total loading time, and (3) the customer satisfaction. Our robust multi-response data mining technique is elucidated for a ten-replicate run study dictated by an L9(34) orthogonal array scheme where any uncontrolled noise embedded contribution has not been necessarily excluded. 相似文献