全文获取类型
收费全文 | 45359篇 |
免费 | 3957篇 |
国内免费 | 3067篇 |
专业分类
化学 | 30951篇 |
晶体学 | 528篇 |
力学 | 2064篇 |
综合类 | 281篇 |
数学 | 4887篇 |
物理学 | 13672篇 |
出版年
2023年 | 401篇 |
2022年 | 467篇 |
2021年 | 943篇 |
2020年 | 1068篇 |
2019年 | 1146篇 |
2018年 | 935篇 |
2017年 | 936篇 |
2016年 | 1580篇 |
2015年 | 1512篇 |
2014年 | 1944篇 |
2013年 | 2951篇 |
2012年 | 3577篇 |
2011年 | 3903篇 |
2010年 | 2676篇 |
2009年 | 2542篇 |
2008年 | 3267篇 |
2007年 | 3022篇 |
2006年 | 2869篇 |
2005年 | 2574篇 |
2004年 | 2158篇 |
2003年 | 1688篇 |
2002年 | 1630篇 |
2001年 | 1212篇 |
2000年 | 954篇 |
1999年 | 650篇 |
1998年 | 473篇 |
1997年 | 446篇 |
1996年 | 485篇 |
1995年 | 397篇 |
1994年 | 388篇 |
1993年 | 382篇 |
1992年 | 359篇 |
1991年 | 300篇 |
1990年 | 205篇 |
1989年 | 197篇 |
1988年 | 197篇 |
1987年 | 157篇 |
1986年 | 123篇 |
1985年 | 200篇 |
1984年 | 130篇 |
1983年 | 110篇 |
1982年 | 133篇 |
1981年 | 95篇 |
1980年 | 92篇 |
1978年 | 95篇 |
1977年 | 91篇 |
1976年 | 98篇 |
1975年 | 104篇 |
1974年 | 81篇 |
1973年 | 106篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Pomogaev V. A. Lee H. J. Goh E. Tchaikovskaya O. N. Kononov A. I. Avramov P. V. 《Russian Physics Journal》2022,64(11):2076-2081
Russian Physics Journal - Theoretical calculations of excited states in the complexes of gold and silver three-atom nanoclusters with carbon quantum nanodots are performed using the M062X... 相似文献
2.
Lee Bryan Tian Siyu Xiong Guoping Yang Ying Zhu Xiaoshan 《Journal of nanoparticle research》2022,24(4):1-15
Journal of Nanoparticle Research - Polycrystalline metallic copper nanoparticle samples with the average particle sizes ranging from 53 to 80 nm were controllably prepared by the wet... 相似文献
3.
Science China Chemistry - 相似文献
4.
Zhi Sun Mengfan Zhao Lihua Zuo Shengnan Zhou Feng Fan Qingquan Jia Lianping Xue Hanbing Li Jian Kang Xiaojian Zhang 《Journal of separation science》2022,45(2):518-528
Juglandis Mandshuricae Cortex is the bark of Juglans mandshurica Maxim., which has been used as a folk medicine plant in China and India. In this study, an ultra-high performance liquid chromatography–quadrupole/orbitrap high-resolution mass spectrometry method was developed to clarify and quantify the chemical profiling of Juglandis Mandshuricae Cortex rapidly. A total of 113 compounds were characterized. Among them, seven flavonoids were simultaneously quantified in 15 min, including myricetin, myricetrin, taxifolin, kaempferol, quercetin, quercitrin, and naringenin. The method was validated for accuracy, precision, and the limits of detection and quantification. All calibration curves showed a good linear relationship (r > 0.9990) within test ranges. The intra- and inter-day relative standard deviations were less than 2.16%. Accuracy validation showed that the recovery was between 95.6 and 101.3% with relative standard deviation values below 2.85%. The validated method was successfully applied to determine the contents of seven flavones in Juglandis Mandshuricae Cortex from seven sources and the contents of these places were calculated respectively. This method provides a theoretical basis for further developing the medicinal value of Juglandis Mandshuricae Cortex. 相似文献
5.
Pirozerskii A. L. Charnaya E. V. Lee M. K. Chang L.-J. Naumov S. V. Domozhirova A. N. Marchenkov V. V. 《Physics of the Solid State》2022,64(2):80-84
Physics of the Solid State - The discovery of extreme magnetoresistance (MR) in nonmagnetic materials attracted attention to WTe2 semimetal. We studied MR in a single crystal of tungsten... 相似文献
6.
Yersak Thomas A. Hao Fang Kang Chansoon Salvador James R. Zhang Qinglin Malabet Hernando Jesus Gonzalez Cai Mei 《Journal of Solid State Electrochemistry》2022,26(3):709-718
Journal of Solid State Electrochemistry - In this study, hot pressing was evaluated as a method of cell fabrication to increase the energy density of next-generation all-solid-state batteries with... 相似文献
7.
Ryu Hoon-Hee Lee Soo-Been Sun Yang-Kook 《Journal of Solid State Electrochemistry》2022,26(9):2097-2105
Journal of Solid State Electrochemistry - Preparing a high-performance Ni-rich single-crystal cathode for Li-ion batteries is challenging. This is because calcination must be performed at a high... 相似文献
8.
9.
CdS/Si nanofilm heterojunctions based on amorphous silicon films:Fabrication,structures,and electrical properties 下载免费PDF全文
Shortening the distance between the depletion region and the electrodes to reduce the trapped probability of carriers is a useful approach for improving the performance of heterojunction.The CdS/Si nanofilm heterojunctions are fabricated by using the radio frequency magnetron sputtering method to deposit the amorphous silicon nanofilms and Cd S nanofilms on the ITO glass in turn.The relation of current density to applied voltage(I-V)shows the obvious rectification effect.From the analysis of the double logarithm I-V curve it follows that below~2.73 V the electron behaviors obey the Ohmic mechanism and above~2.73 V the electron behaviors conform to the space charge limited current(SCLC)mechanism.In the SCLC region part of the traps between the Fermi level and conduction band are occupied,and with the increase of voltage most of the traps are occupied.It is believed that Cd S/Si nanofilm heterojunction is a potential candidate in the field of nano electronic and optoelectronic devices by optimizing its fabricating procedure. 相似文献
10.
Liu Jinjie Yang Xinmin Zeng Shengda Zhao Yong 《Journal of Optimization Theory and Applications》2022,193(1):877-909
Journal of Optimization Theory and Applications - In this paper, we introduce and investigate a new kind of coupled systems, called coupled variational inequalities, which consist of two elliptic... 相似文献