全文获取类型
收费全文 | 34741篇 |
免费 | 5501篇 |
国内免费 | 4456篇 |
专业分类
化学 | 25749篇 |
晶体学 | 508篇 |
力学 | 1834篇 |
综合类 | 388篇 |
数学 | 3922篇 |
物理学 | 12297篇 |
出版年
2024年 | 18篇 |
2023年 | 630篇 |
2022年 | 734篇 |
2021年 | 1007篇 |
2020年 | 1380篇 |
2019年 | 1353篇 |
2018年 | 1088篇 |
2017年 | 1097篇 |
2016年 | 1598篇 |
2015年 | 1569篇 |
2014年 | 1977篇 |
2013年 | 2523篇 |
2012年 | 3113篇 |
2011年 | 3200篇 |
2010年 | 2281篇 |
2009年 | 2177篇 |
2008年 | 2512篇 |
2007年 | 2208篇 |
2006年 | 2115篇 |
2005年 | 1727篇 |
2004年 | 1395篇 |
2003年 | 1119篇 |
2002年 | 1039篇 |
2001年 | 837篇 |
2000年 | 712篇 |
1999年 | 725篇 |
1998年 | 609篇 |
1997年 | 493篇 |
1996年 | 503篇 |
1995年 | 454篇 |
1994年 | 414篇 |
1993年 | 384篇 |
1992年 | 311篇 |
1991年 | 291篇 |
1990年 | 262篇 |
1989年 | 195篇 |
1988年 | 134篇 |
1987年 | 105篇 |
1986年 | 112篇 |
1985年 | 85篇 |
1984年 | 49篇 |
1983年 | 48篇 |
1982年 | 42篇 |
1981年 | 26篇 |
1980年 | 13篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1957年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
Pu Lin Peifu Luo Yating Guo Honglong Qiu Min Wang Guoming Huang 《Particle & Particle Systems Characterization》2021,38(10):2100113
In this study, the synthesis of TaN nanosheets and their application in theranostic agents is reported. After coating polyethylene glycol (PEG) on the TaN nanosheets, the as-synthesized PEG-modified TaN nanosheets (TaN-PEG) show good stability and biocompatibility. Because of their high absorbance in the near-IR region, TaN-PEG can be utilized as photoacoustic imaging contrast agents for tumor imaging. Moreover, TaN-PEG has significant photothermal conversion performance, exhibiting effective laser-induced tumor ablation capability. The TaN-PEG possessing excellent photoacoustic contrast effect and photothermal properties thus have great promise in theranostic applications, especially imaging-guided cancer treatment. 相似文献
2.
Acta Mathematicae Applicatae Sinica, English Series - So far there have been few results presented on the exponential stability for time-changed stochastic differential equations. The main aim of... 相似文献
3.
Liu Zhu Sun Wen-Yang Fan Xiao-Gang Wang Dong Ye Liu 《International Journal of Theoretical Physics》2021,60(7):2412-2422
International Journal of Theoretical Physics - In this paper, we investigate Einstein-Podolsky-Rosen steering, Bell non-locality, first-order coherence and concurrence in the spin- $\frac {1}{2}$... 相似文献
4.
Potential Analysis - The purpose of this paper is to provide necessary and sufficient conditions of the boundedness for singular integrals on the local Hardy space and its dual. Particularly the... 相似文献
5.
This study is to numerically test the interfacial instability of ferrofluid flow under the presence of a vacuum magnetic field. The ferrofluid parabolized stability equations(PSEs) are derived from the ferrofluid stability equations and the Rosensweig equations, and the characteristic values of the ferrofluid PSEs are given to describe the ellipticity of ferrofluid flow. Three numerical models representing specific cases considering with/without a vacuum magnetic field or viscosity are created to mathematically examine the interfacial instability by the computation of characteristic values. Numerical investigation shows strong dependence of the basic characteristic of ferrofluid Rayleigh-Taylor instability(RTI) on viscosity of ferrofluid and independence of the vacuum magnetic field.For the shock wave striking helium bubble, the magnetic field is not able to trigger the symmetry breaking of bubble but change the speed of the bubble movement. In the process of droplet formation from a submerged orifice, the collision between the droplet and the liquid surface causes symmetry breaking. Both the viscosity and the magnetic field exacerbate symmetry breaking. The computational results agree with the published experimental results. 相似文献
6.
Song Zi-Long Zhu Yun Liu Jing-Rui Guo Shu-Ke Gu Yu-Cheng Han Xinya Dong Hong-Qiang Sun Qi Zhang Wei-Hua Zhang Ming-Zhi 《Molecular diversity》2021,25(1):205-221
Molecular Diversity - Based on the strategy of diversity-oriented synthesis and the structures of natural product pimprinine and streptochlorin, two series of novel pimprinine derivatives... 相似文献
7.
Nonlinear Dynamics - The paper studies the stability and control of radial deployment of an electric solar wind sail with the consideration of high-order modes of elastic tethers. The electric... 相似文献
8.
Chinese Journal of Polymer Science - The emerging chemical recyclable polymers, such as poly(γ-butyrolactone) (PGBL) and poly((R)-3,4-trans six-membered ring-fused GBL) (P((R)-M)), provide a... 相似文献
9.
Li Hongying Liu Xiaoxuan Huang Jiaqi Zhu Wenjuan Ding Aimin Yao Chengli Zhu Jinmiao 《Crystallography Reports》2022,67(7):1231-1238
Crystallography Reports - Sodium dodecyl sulfonate and rape pollen were selected as soft and hard templates to induce ZnO formation under hydrothermal conditions, respectively. In the preparation... 相似文献
10.
铋基卤化物材料因其无毒和优良的光电性能而显示出巨大的应用潜力。BiI3作为一种层状重金属半导体,已被用于X射线检测、γ射线检测和压力传感器等领域,最近其作为一种薄膜太阳能电池吸收材料备受关注。本文采用简单的气相输运沉积(VTD)法,以BiI3晶体粉末作为蒸发源,在玻璃基底上得到高质量c轴择优取向的BiI3薄膜。并通过研究蒸发源温度和沉积距离对薄膜物相和形貌的影响,分析了BiI3薄膜择优生长的机理。结果表明VTD法制备的BiI3薄膜属于三斜晶系,其光学带隙为~1.8 eV。沉积温度对薄膜的择优取向有较大影响,在沉积温度低于270 ℃时,沉积的薄膜具有沿c轴择优取向生长的特点,超过此温度,c轴择优取向生长消失。在衬底温度为250 ℃、沉积距离为15 cm时制备的薄膜结晶性能最好,晶体形貌为片状八面体。 相似文献