全文获取类型
收费全文 | 111623篇 |
免费 | 1307篇 |
国内免费 | 993篇 |
专业分类
化学 | 40747篇 |
晶体学 | 1303篇 |
力学 | 8076篇 |
综合类 | 81篇 |
数学 | 36773篇 |
物理学 | 26943篇 |
出版年
2023年 | 158篇 |
2022年 | 427篇 |
2021年 | 662篇 |
2020年 | 709篇 |
2019年 | 897篇 |
2018年 | 11601篇 |
2017年 | 11448篇 |
2016年 | 7696篇 |
2015年 | 1734篇 |
2014年 | 1870篇 |
2013年 | 2726篇 |
2012年 | 5946篇 |
2011年 | 12684篇 |
2010年 | 7860篇 |
2009年 | 8149篇 |
2008年 | 8783篇 |
2007年 | 10757篇 |
2006年 | 2141篇 |
2005年 | 2583篇 |
2004年 | 2455篇 |
2003年 | 2595篇 |
2002年 | 1632篇 |
2001年 | 837篇 |
2000年 | 1106篇 |
1999年 | 673篇 |
1998年 | 765篇 |
1997年 | 673篇 |
1996年 | 413篇 |
1995年 | 244篇 |
1994年 | 247篇 |
1993年 | 200篇 |
1992年 | 178篇 |
1991年 | 181篇 |
1990年 | 155篇 |
1989年 | 126篇 |
1988年 | 129篇 |
1987年 | 124篇 |
1986年 | 116篇 |
1985年 | 133篇 |
1984年 | 117篇 |
1983年 | 88篇 |
1982年 | 115篇 |
1981年 | 105篇 |
1980年 | 114篇 |
1979年 | 102篇 |
1978年 | 101篇 |
1977年 | 79篇 |
1976年 | 68篇 |
1975年 | 58篇 |
1973年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
Differential Equations - For a spectrally controllable linear autonomous system with incommensurable delays, we construct a dynamic state feedback in the form of a differential-difference... 相似文献
2.
JETP Letters - Extraordinary multiparticle effects in quantizing magnetic fields that are manifested in strongly interacting two-dimensional electron systems in MgZnO/ZnO heterostructures have been... 相似文献
3.
Kuz’mina L. G. Navasardyan M. A. Kalle P. Bezzubov S. I. 《Crystallography Reports》2021,66(3):420-423
Crystallography Reports - The crystal and molecular structures of Cl–C6H4–O–C16H33 (I) have been studied, and its differential scanning calorimetry (DSC) study is performed.... 相似文献
4.
Daulbaev O. Isaenko L. I. Bogdzel’ A. A. Lobanov S. I. Krinitsyn P. G. Milkov V. M. Belushkin A. V. 《Crystallography Reports》2022,67(3):464-469
Crystallography Reports - Two LiInSe2 single crystals, grown under different conditions, have been studied. Characteristics of these crystals for neutron detection have been compared using... 相似文献
5.
Meccanica - In gear pair actual alternating meshing process, the comprehensive errors of the transmission system and the thermal elastic deformation of the teeth body cause the gears in the meshing... 相似文献
6.
Kai Cheng Xiao-Shuai Zhang Jie An Cheng Li Ruo-Yun Zhang Run Ye Prof. Dr. Bang-Jiao Ye Prof. Dr. Bo Liu Prof. Dr. Yuan-Di Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(31):7553-7560
Given their superior penetration depths, photosensitizers with longer absorption wavelengths present broader application prospects in photodynamic therapy (PDT). Herein, Ag2S quantum dots were discovered, for the first time, to be capable of killing tumor cells through the photodynamic route by near-infrared light irradiation, which means relatively less excitation of the probe compared with traditional photosensitizers absorbing short wavelengths. On modification with polydopamine (PDA), PDA-Ag2S was obtained, which showed outstanding capacity for inducing reactive oxygen species (increased by 1.69 times). With the addition of PDA, Ag2S had more opportunities to react with surrounding O2, which was demonstrated by typical triplet electron spin resonance (ESR) analysis. Furthermore, the PDT effects of Ag2S and PDA-Ag2S achieved at longer wavelengths were almost identical to the effects produced at 660 nm, which was proved by studies in vitro. PDA-Ag2S showed distinctly better therapeutic effects than Ag2S in experiments in vivo, which further validated the enhanced regulatory effect of PDA. Altogether, a new photosensitizer with longer absorption wavelength was developed by using the hitherto-unexplored photodynamic function of Ag2S quantum dots, which extended and enhanced the regulatory effect originating from PDA. 相似文献
7.
In the paper, the authors establish several integral representations for the generating functions of the large and little Schröder numbers and for the large and little Schröder numbers. 相似文献
8.
9.
10.