全文获取类型
收费全文 | 2454篇 |
免费 | 312篇 |
国内免费 | 336篇 |
专业分类
化学 | 1775篇 |
晶体学 | 21篇 |
力学 | 107篇 |
综合类 | 5篇 |
数学 | 360篇 |
物理学 | 834篇 |
出版年
2024年 | 7篇 |
2023年 | 55篇 |
2022年 | 87篇 |
2021年 | 101篇 |
2020年 | 120篇 |
2019年 | 88篇 |
2018年 | 76篇 |
2017年 | 78篇 |
2016年 | 118篇 |
2015年 | 108篇 |
2014年 | 113篇 |
2013年 | 158篇 |
2012年 | 196篇 |
2011年 | 210篇 |
2010年 | 111篇 |
2009年 | 142篇 |
2008年 | 150篇 |
2007年 | 140篇 |
2006年 | 110篇 |
2005年 | 108篇 |
2004年 | 80篇 |
2003年 | 60篇 |
2002年 | 50篇 |
2001年 | 58篇 |
2000年 | 55篇 |
1999年 | 49篇 |
1998年 | 37篇 |
1997年 | 34篇 |
1996年 | 52篇 |
1995年 | 49篇 |
1994年 | 39篇 |
1993年 | 32篇 |
1992年 | 32篇 |
1991年 | 39篇 |
1990年 | 30篇 |
1989年 | 19篇 |
1988年 | 21篇 |
1987年 | 19篇 |
1986年 | 13篇 |
1985年 | 12篇 |
1984年 | 11篇 |
1983年 | 5篇 |
1982年 | 9篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1968年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有3102条查询结果,搜索用时 15 毫秒
111.
112.
The aminolysis of a novel activated ester resin was utilized for kinetic study via continuous in situ fluorescence measurements. A variety of resin compositions (polystyrene, JandaJel, ArgoPore, TentaGel, NovaGel, and PEGA) and solvents (dimethylformamide, acetonitrile, tetrahydrofuran, 1,2-dichlorethane, and toluene) were tested to compare their effects on the reaction rate. A linear relationship between the reaction rate and (solvent polarity x swelling of resin) was elucidated for the aminolysis reaction. 相似文献
113.
根据气体冷却服的特点,对不同进风型式下气体冷却服中空气流动与换热进行研究。建立了进气口加设挡板层、进气口带均流器型和直吹型3种型式气体冷却服(服装夹层)中冷却空气流动过程的数学模型。对气体的流动过程进行分析,结果表明:不同的进风型式对气体冷却服空气层的温度分布状况、平均气流流速、平均温度、对流散热量影响较大;其中进气口加设挡板层的服装空气夹层温度分布最均匀,进气直吹型的平均气流流速最大,对流散热效果最好。研究结果为气体冷却服进一步的布风优化设计提供了理论和应用依据。 相似文献
114.
115.
116.
<正>Two new cage compounds,4-trinitroethyl-10-nitro-2,6,8,12-tetraacetylhexaazaisowurtzitane(3) and 4-trinitroethyl- 2,6,8,10,12-pentanitrohexaazaisowurtzitane(4),containing trinitromethyl group were synthesized by a novel method,and their structures were confirmed by IR,~1H NMR,MS and single crystal X-ray.DSC result shows that compound 4 has surprising thermal stability and could be a potential energetic compound. 相似文献
117.
Zhang Ning Zhang Bin Pang Yong Yang Hong-Sheng Zong Lu Duan Yong-Xin Zhang Jian-Ming 《高分子科学》2022,40(4):373-383
Chinese Journal of Polymer Science - Macromolecule nanocrystal network and strong interfacial interaction are always beneficial to enhance the mechanical property of polymer-based nanocomposites.... 相似文献
118.
Jing He Mohan Yu Maofu Pang Yanqing Fan Zhe Lian Dr. Ying Wang Prof. Wenguang Wang Prof. Yajun Liu Prof. Hua Jiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(13):e202103832
Structural designs combining cycloparaphenylenes (CPPs) backbone with planar chiral [2.2]paracyclophane ([2.2]PCP) lead to optical-active chiral macrocycles with intriguing properties. X-ray crystal analysis revealed aesthetic necklace-shaped structures and size-dependent packages with long-range channels. The macrocycles exhibit unique photophysical properties with high fluorescence quantum yield of up to 82 %, and the fluorescent color varies with ring size. In addition, size-dependent chiroptical properties with moderately large CPL dissymmetry factor of 10−3 and CPL brightness in the range of 30–40 M−1 cm−1 were observed. 相似文献
119.
Qingqing Ma Shanlin Xu Zhaodong Zhai Kai Wang Xueli Liu Prof. Haibin Xiao Prof. Shuping Zhuo Prof. Yuying Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(39):e202200828
Peroxynitrite (ONOO−) as a major reactive oxygen species plays important roles in cellular signal transduction and homeostatic regulation. Precise detection of ONOO− in biological systems is vital for exploring its physiological and pathological function. Among numerous detection methods, fluorescence imaging technology using fluorescent probes offers some advantages, including simple operation, high sensitivity and selectivity, as well as real-time and nondestructive detection. In particular, ratiometric fluorescent probes, in which the built-in calibration of the two emission bands prevents interference from the biological environment, have been extensively employed to monitor the fluctuation of bioactive species. In this review, we will discuss small-molecule ratiometric fluorescent probes for ONOO− in live cells or in vivo, which involves chemical structures, response mechanisms, and biological applications. Moreover, the challenges and future prospects of ONOO−-responsive ratiometric fluorescent probe are also proposed. 相似文献
120.
Yahui Yan Rahima Abdulla Xiaoyan Liu Shuping Li Haji Akber Aisa 《Journal of separation science》2022,45(13):2148-2160