全文获取类型
收费全文 | 42282篇 |
免费 | 6589篇 |
国内免费 | 6710篇 |
专业分类
化学 | 32898篇 |
晶体学 | 684篇 |
力学 | 1992篇 |
综合类 | 556篇 |
数学 | 4822篇 |
物理学 | 14629篇 |
出版年
2024年 | 29篇 |
2023年 | 609篇 |
2022年 | 854篇 |
2021年 | 1208篇 |
2020年 | 1496篇 |
2019年 | 1571篇 |
2018年 | 1320篇 |
2017年 | 1340篇 |
2016年 | 1886篇 |
2015年 | 1957篇 |
2014年 | 2461篇 |
2013年 | 3230篇 |
2012年 | 3791篇 |
2011年 | 3971篇 |
2010年 | 3038篇 |
2009年 | 2892篇 |
2008年 | 3262篇 |
2007年 | 2998篇 |
2006年 | 2784篇 |
2005年 | 2271篇 |
2004年 | 1871篇 |
2003年 | 1566篇 |
2002年 | 1566篇 |
2001年 | 1309篇 |
2000年 | 1047篇 |
1999年 | 878篇 |
1998年 | 592篇 |
1997年 | 562篇 |
1996年 | 466篇 |
1995年 | 447篇 |
1994年 | 408篇 |
1993年 | 332篇 |
1992年 | 296篇 |
1991年 | 245篇 |
1990年 | 218篇 |
1989年 | 172篇 |
1988年 | 120篇 |
1987年 | 103篇 |
1986年 | 100篇 |
1985年 | 84篇 |
1984年 | 44篇 |
1983年 | 34篇 |
1982年 | 30篇 |
1981年 | 20篇 |
1980年 | 15篇 |
1979年 | 11篇 |
1978年 | 13篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1973年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
A Pronounced Halogen Effect on the Organogelation Properties of Peripherally Halogen Functionalized Poly(benzyl ether) Dendrons 下载免费PDF全文
Prof. Dr. Yu Feng Hui Chen Zhi‐Xiong Liu Yan‐Mei He Prof. Dr. Qing‐Hua Fan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4980-4990
An interesting halogen‐substituent effect on the organogelation properties of poly(benzyl ether) dendrons is reported. A new class of poly(benzyl ether) dendrons with halo substituents decorating their periphery was synthesized and fully characterized. A systematic study on the gelation abilities, thermotropic behaviors, aggregated microstructures, and mechanical properties of self‐assembled organogels was performed to elucidate the halogen‐substituent effects on their organogelation propensity. It was found that the exact halogen substitutions on the periphery of dendrons exert a profound effect on the organogelation propensity, and dendrons G n ‐Cl (n=2, 3) and G2‐I proved to be highly efficient organogelators. The cooperation of multiple π–π, dispersive halogen, CH–π, and weak C?H ??? X hydrogen‐bonding interactions were found to be the key contributor to forming the self‐assembled gels. Dendritic organogels formed from G n ‐Cl (n=2, 3) in 1,2‐dichloroethane exhibited thixotropic‐responsive properties, and such thixotropic organogels are promising materials for future research and applications. 相似文献
94.
95.
Loading of a Coordination Polymer Nanobelt on a Functional Carbon Fiber: A Feasible Strategy for Visible‐Light‐Active and Highly Efficient Coordination‐Polymer‐Based Photocatalysts 下载免费PDF全文
Prof. Dr. Xin‐Xin Xu Dr. Hong‐Yu Yang Dr. Zhen‐Yu Li Prof. Dr. Xiao‐Xia Liu Prof. Dr. Xiu‐Li Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3821-3830
To improve the photocatalytic properties of coordination polymers under irradiation in the visible‐light region, coordination polymer nanobelts (CPNB) were loaded on functional carbon fiber (FCF) through the use of a simple colloidal blending process. The resulting coordination polymer nanobelt loaded functional carbon fiber composite material (CPNB/FCF) exhibited dramatically improved photocatalytic activity for the degradation of rhodamine B (RhB) under visible‐light irradiation. Optical and electrochemical methods illustrated the enhanced photocatalytic activity of CPNB/FCF originated from high separation efficiency of photogenerated electrons and holes on the interface of CPNB and FCF, which was produced by the synergy effect between them. In the composite material, the role of FCF could be described as photosensitizer and good electron transporter. For FCF, the number of functional groups on its surface has a significant influence on the photocatalytic performance of the resulting CPNB/FCF composite material, and an ideal FCF carrier was obtained as a highly efficient CPNB/FCF photocatalyst. CPNB/FCF showed outstanding stability during the degradation of rhodamine B (RhB); thus, the material is suitable for use as a photocatalyst in the treatment of organic dyes in water. 相似文献
96.
97.
98.
Dual‐signal amplification strategy for ultrasensitive chemiluminescence detection of PDGF–BB in capillary electrophoresis 下载免费PDF全文
Jun‐Tao Cao Hui Wang Shu‐Wei Ren Yong‐Hong Chen Yan‐Ming Liu 《Biomedical chromatography : BMC》2015,29(12):1866-1870
Many efforts have been made toward the achievement of high sensitivity in capillary electrophoresis coupled with chemiluminescence detection (CE‐CL). This work describes a novel dual‐signal amplification strategy for highly specific and ultrasensitive CL detection of human platelet‐derived growth factor–BB (PDGF–BB) using both aptamer and horseradish peroxidase (HRP) modified gold nanoparticles (HRP–AuNPs–aptamer) as nanoprobes in CE. Both AuNPs and HRP in the nanoprobes could amplify the CL signals in the luminol–H2O2 CL system, owing to the excellent catalytic behavior of AuNPs and HRP in the CL system. Meanwhile, the high affinity of aptamer modified on the AuNPs allows detection with high specificity. As proof‐of‐concept, the proposed method was employed to quantify the concentration of PDGF–BB from 0.50 to 250 fm with a detection limit of 0.21 fm. The applicability of the assay was further demonstrated in the analysis of PDGF–BB in human serum samples with acceptable accuracy and reliability. The result of this study exhibits distinct advantages, such as high sensitivity, good specificity, simplicity, and very small sample consumption. The good performances of the proposed strategy provide a powerful avenue for ultrasensitive detection of rare proteins in biological sample, showing great promise in biochemical analysis. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
99.
100.