全文获取类型
收费全文 | 3911篇 |
免费 | 794篇 |
国内免费 | 1381篇 |
专业分类
化学 | 2963篇 |
晶体学 | 193篇 |
力学 | 348篇 |
综合类 | 121篇 |
数学 | 537篇 |
物理学 | 1924篇 |
出版年
2024年 | 17篇 |
2023年 | 72篇 |
2022年 | 178篇 |
2021年 | 194篇 |
2020年 | 160篇 |
2019年 | 172篇 |
2018年 | 164篇 |
2017年 | 169篇 |
2016年 | 128篇 |
2015年 | 200篇 |
2014年 | 242篇 |
2013年 | 310篇 |
2012年 | 284篇 |
2011年 | 318篇 |
2010年 | 356篇 |
2009年 | 341篇 |
2008年 | 375篇 |
2007年 | 374篇 |
2006年 | 356篇 |
2005年 | 287篇 |
2004年 | 241篇 |
2003年 | 153篇 |
2002年 | 150篇 |
2001年 | 145篇 |
2000年 | 165篇 |
1999年 | 107篇 |
1998年 | 49篇 |
1997年 | 27篇 |
1996年 | 38篇 |
1995年 | 41篇 |
1994年 | 46篇 |
1993年 | 37篇 |
1992年 | 40篇 |
1991年 | 26篇 |
1990年 | 26篇 |
1989年 | 18篇 |
1988年 | 8篇 |
1987年 | 13篇 |
1986年 | 17篇 |
1985年 | 6篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1981年 | 3篇 |
1979年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1971年 | 2篇 |
1962年 | 1篇 |
1960年 | 1篇 |
1959年 | 5篇 |
排序方式: 共有6086条查询结果,搜索用时 31 毫秒
1.
Yujie Gao Zhiye Qiu Lei Liu Mengmeng Li Bingjie Xu Dan Yu Dongming Qi Jindan Wu 《Journal of polymer science. Part A, Polymer chemistry》2022,60(15):2191-2212
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.
Yujie Xiong 《中国科学:化学(英文版)》2022,65(1):5-6
Photoelectrochemical(PEC)technique represents a promising approach to chemical transformation by harvesting sustainable solar energy.Despite the wide applications of PEC systems such as environmental remediation and solar energy conversion,the reported PEC reactions are dominated by the radical-based processes that are initiated by the single electron transfer between photo-induced carriers and adsorbed species on photoelectrode surface[1,2].For instance,hydroxyl radicals are often involved in the PEC oxidation reactions.As well known,it is a grand challenge to control the formation and evolution rates of radicals,which inevitably leads to the unsatisfactory product selectivity of PEC reactions.Naturally,such a circumstance brings about a question to the research community whether a different mechanism can be established to sustain efficient and selective oxygenation.Recently,based on their previous findings on PEC water oxidation[3,4],Zhao and coworkers[5]reported that many substrates can be oxidized in an oxygen atom transfer(OAT)pathway,a non-radical two electron process,to oxygenated products byα-Fe2O3 photoanodes. 相似文献
3.
4.
考虑电子的反冲并利用康普顿散射,研究了激光同步辐射光源(LSS)辐射的光子波长、光子能量。结果表明,对于不同的γ,LSS辐射的光子波长和能量有不同的近似公式。当γ<<λ1/4λe时,LSS辐射的光子波长λ2≈λ1/4γ2,能量(εc2≈4γ2εc1;当γ>>λ1/4λe时,LSS辐射的光子波长λ2≈λe/γ,能量cε2≈m0γc2;结果表明,LSS辐射的条件是种子激光的波长λ1大于电子的物质波波长λm;LSS辐射的极值波长是λ2m ax=h/m0γv,极值能量是cε2m ax=βeε;本文后半部分提出了利用北京正负电子对撞机的强流高亮度电子束与激光的康普顿背散射产生单色γ射线的建议。 相似文献
5.
6.
7.
GU Bai-Ping REN Zhong-Zhou 《理论物理通讯》2005,44(2):337-342
The Dirac optical potential for p-^14 Be elastic scattering is evaluated by the relativistic impulse approximation. Each of the real part and the imaginary part of the potential shows a pronounced “long tail” for the proton elastic scattering from halo nucleus ^14Be compared with the potentials for proton scattering from its adjacent nuclei ^12C and ^16O, which do not have halo structures.This kind of “long tail” phenomenon suggests another signature for halo nuclei. 相似文献
8.
分子生物学中基因无方向的反向基因组重排问题在数学上已被证明是一个NP困难问题.基于断点图的概念,给出一个时间复杂性为O(max{b^(π),nb(π)}),空间复杂性为0(n)的求其近似最优解的算法.其中n为基因组中基因个数,π=(π1,π2,…,πn)表示n个基因的一种排列,b(π)表示排列π中的断点数.数据实验的结果表明,该近似算法可以求得较好的结果. 相似文献
9.
10.
REN QingBao ZHU WeiTing HONG Bo & ZHANG YuHeng Department of Physics Lishui University Lishui China National High Magnetic Field Laboratory University of Science Technology of China Hefei China 《中国科学G辑(英文版)》2007,(3)
Magnetic properties of Nd_(0.5)Sr_(0.5)Mn_(1-x)(Ga_x, Ti_x)O_3 system (0.04≤x≤0.4) were inves- tigated through magnetization and electron spin resonance (ESR) measurements. It was observed that a small amount of Ti substitution for Mn will destroy the charge-ordering (CO) phase completely and induce the cluster-spin-glass phase in the system, which displays a procedure of collapse of CO and of an enhancement of spin ordering (SO) phase. In contrast, the Ga substitution for Mn induces a melt- ing of CO phase in the system. It was observed that with substitution the CO phase is suppressed gradually and the remanent CO phase is retained all the while, and withal, there is a co-existence of AFM CO phase and FM SO at low temperature. In addition, an abrupt rise of magnetization was observed in M-T curves. We attributed this abnormal phenomenon to a transition from canted AFM SO to FM SO in CO region. 相似文献