首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   21428篇
  免费   3956篇
  国内免费   3248篇
化学   16075篇
晶体学   413篇
力学   1164篇
综合类   209篇
数学   2429篇
物理学   8342篇
  2024年   55篇
  2023年   442篇
  2022年   782篇
  2021年   914篇
  2020年   1009篇
  2019年   994篇
  2018年   828篇
  2017年   851篇
  2016年   1169篇
  2015年   1204篇
  2014年   1514篇
  2013年   1812篇
  2012年   2161篇
  2011年   2215篇
  2010年   1561篇
  2009年   1406篇
  2008年   1590篇
  2007年   1253篇
  2006年   1145篇
  2005年   942篇
  2004年   787篇
  2003年   569篇
  2002年   498篇
  2001年   410篇
  2000年   324篇
  1999年   366篇
  1998年   255篇
  1997年   190篇
  1996年   234篇
  1995年   189篇
  1994年   171篇
  1993年   124篇
  1992年   109篇
  1991年   111篇
  1990年   98篇
  1989年   77篇
  1988年   48篇
  1987年   36篇
  1986年   56篇
  1985年   32篇
  1984年   18篇
  1983年   19篇
  1982年   12篇
  1981年   12篇
  1979年   4篇
  1977年   3篇
  1976年   4篇
  1975年   4篇
  1974年   3篇
  1957年   5篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Refractory wounds have always been an important issue to healthcare systems, whose healing process is always delayed by multiple factors, including bacterial infections, chronic inflammation, and excessive exudates, etc. Employing multifunctional wound dressings is recognized as an effective strategy to deal with refractory wounds, which has yielded promising outcomes in recent years. Among these advanced wound dressings, fibrous dressings have gained growing attention due to their unique merits. Such wound dressings have demonstrated great potential in delivering theranostic agents, such as antibacterial agents, anti-inflammatory drugs, growth factors, and diagnostic probes, etc., for the purposes of accelerating wound healing. This paper reviews the development of multifunctional fibrous dressings and their applications in treating refractory wounds. The construction approaches of novel fibrous dressing with capabilities of antibacterial, anti-inflammation, exudate management and diagnosis were also introduced. Furthermore, the existing problems and challenges are also discussed briefly.  相似文献   
2.
Tian  Xiu-Zhi  Yang  Rui  Ma  Jia-Jia  Ni  Yong-Hao  Deng  Hai-Bo  Dai  Lei  Tan  Jiao-Jun  Zhang  Mei-Yun  Jiang  Xue 《高分子科学》2022,40(7):789-798
Chinese Journal of Polymer Science - Antistatic and strength properties are of vital importance for polyurethane rubber used in moving parts of many industrial instruments. Herein, polyurethane was...  相似文献   
3.
4.
International Journal of Theoretical Physics - Quantum coherence, coming from quantum superposition, occupies a significant position in the field of physics. We put forward a lower bound of the...  相似文献   
5.
Journal of Optimization Theory and Applications - We distinguish two kinds of piecewise linear functions and provide an interesting representation for a piecewise linear function between two normed...  相似文献   
6.
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   
7.
8.
A graphic sequence π =(d1, d2,..., dn) is said to be forcibly k-edge-connected if every realization of π is k-edge-connected. In this paper, we obtain a new sufficient degree condition for π to be forcibly k-edgeconnected. We also show that this new sufficient degree condition implies a strongest monotone degree condition for π to be forcibly 2-edge-connected and a conjecture about a strongest monotone degree condition for π to be forcibly 3-edge-connected due to...  相似文献   
9.
The molecular geometries and dissociation energies of AnO (An = Bk–Lr) molecules were first obtained at thecoupled-cluster single-, double-, and perturbative triple-excitations [CCSD(T)] level of theory. Four hybrid functionals,B3LYP, M06-2X, TPSSh, and PBE0, were also employed in the calculations for the sake of comparison. In comparison ofthe CCSD(T) results, B3LYP, TPSSh, and PBE0 functionals can obtain more appropriate results than M06-2X and MP2.The analyses on molecular orbitals show that the 7s, 6d, and 5f atomic orbitals of actinide (An) atoms participate in thebonding of An–O bonds. The partial covalent nature between An and O atoms is revealed by QTAIM analyses.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号