全文获取类型
收费全文 | 10595篇 |
免费 | 1242篇 |
国内免费 | 1050篇 |
专业分类
化学 | 7963篇 |
晶体学 | 181篇 |
力学 | 419篇 |
综合类 | 87篇 |
数学 | 1333篇 |
物理学 | 2904篇 |
出版年
2024年 | 12篇 |
2023年 | 201篇 |
2022年 | 242篇 |
2021年 | 394篇 |
2020年 | 452篇 |
2019年 | 417篇 |
2018年 | 336篇 |
2017年 | 369篇 |
2016年 | 528篇 |
2015年 | 491篇 |
2014年 | 599篇 |
2013年 | 825篇 |
2012年 | 950篇 |
2011年 | 968篇 |
2010年 | 641篇 |
2009年 | 571篇 |
2008年 | 747篇 |
2007年 | 669篇 |
2006年 | 586篇 |
2005年 | 529篇 |
2004年 | 424篇 |
2003年 | 313篇 |
2002年 | 338篇 |
2001年 | 203篇 |
2000年 | 160篇 |
1999年 | 108篇 |
1998年 | 93篇 |
1997年 | 58篇 |
1996年 | 89篇 |
1995年 | 47篇 |
1994年 | 58篇 |
1993年 | 53篇 |
1992年 | 30篇 |
1991年 | 47篇 |
1990年 | 45篇 |
1989年 | 29篇 |
1988年 | 29篇 |
1987年 | 34篇 |
1986年 | 17篇 |
1985年 | 35篇 |
1984年 | 22篇 |
1983年 | 15篇 |
1982年 | 19篇 |
1981年 | 13篇 |
1980年 | 14篇 |
1979年 | 15篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 4篇 |
1974年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Rui Feng Zi-Ying Li Zhao-Quan Yao Zi-Ang Guo Yi-Nan Zhang Hao-Xiang Sun Wei Li Xian-He Bu 《中国科学:化学(英文版)》2022,65(1):128-134
The rational designability and chemical tunability of metal-organic frameworks(MOFs)are enabling tributes to efficaciously enhance their room temperature phosphorescence(RTP)performance.A family of stable anionic MOFs,[Zn2(4,5-ImDC)2]M2(NKU-132,M=(CH3)2NH2or(CH2CH3)2NH2),featuring significant RTP have been synthesized.By rational cation selection and in-situ replacement from dimethylammonium to diethylammonium,the phosphorescence lifetime is increased from 30.88 to126.3 ms,along with less sensitivity to air.This work provides an anti-quenching and lifetime tuning example for RTP-MOFmaterials via facile host-guest chemistry. 相似文献
2.
Russian Physics Journal - Aiming at problems of low probability of interception and poor anti-jamming performance of the multi-output radar, the numerical simulation based on a chaos optimization... 相似文献
3.
Ribeiro Sabrina Dias Meneguin Andria Bagliotti Barud Hernane da Silva Silva Jhonatan Miguel Oliveira Rafael L. Asuno Rosana Maria Nascimento de Tormin Thiago Faria Muoz Rodrigo Alejandro Abarza Filho Guimes Rodrigues Ribeiro Clovis Augusto 《Journal of Thermal Analysis and Calorimetry》2022,147(13):7265-7275
Journal of Thermal Analysis and Calorimetry - Cellophane film production generates cellulosic residues from scraps, edges, and low-quality films. In this work, cellophane was used as a raw material... 相似文献
4.
5.
6.
We propose a lumped element Josephson parametric amplifier with vacuum-gap-based capacitor.The capacitor is made of quasi-floating aluminum pad and on-chip ground.We take a fabrication process compatible with air-bridge technology,which makes our design adaptable for future on-chip integrated quantum computing system.Further engineering the input impedance,we obtain a gain above 20 dB over 162-MHz bandwidth,along with a quasi quantum-limit noise performance.This work should facilitate the development of quantum information processing and integrated superconducting circuit design. 相似文献
7.
Oliveira M. Rosário Azeitona Margarida Pacheco António Valadas Rui 《Advances in Data Analysis and Classification》2022,16(3):491-520
Advances in Data Analysis and Classification - Symbolic Data Analysis (SDA) is a relatively new field of statistics that extends conventional data analysis by taking into account intrinsic data... 相似文献
9.
This article aims to provide a survey of biological applications of Schiff base macrocycles and their metal complexes, with emphasis given to the synthesis of the compounds and to their uses as antibacterial and antifungal agents. The literature on the subject, published during the 2005–2019 period, is shortly reviewed. This is an informed report collecting information on the addressed topic in a concise systematic way, and can be expected to be useful as a fast literature catalogue for researchers working on this and related domains. 相似文献
10.
AbstractWe study the inverse problem of parameter identification in noncoercive variational problems that commonly appear in applied models. We examine the differentiability of the set-valued parameter-to-solution map using the first-order and the second-order contingent derivatives. We explore the inverse problem using the output least-squares and the modified output least-squares objectives. By regularizing the noncoercive variational problem, we obtain a single-valued regularized parameter-to-solution map and investigate its smoothness and boundedness. We also consider optimization problems using the output least-squares and the modified output least-squares objectives for the regularized variational problem. We give a complete convergence analysis showing that for the output least-squares and the modified output least-squares, the regularized minimization problems approximate the original optimization problems suitably. We also provide the first-order and the second-order adjoint method for the computation of the first-order and the second-order derivatives of the output least-squares objective. We provide discrete formulas for the gradient and the Hessian calculation and present numerical results. 相似文献