全文获取类型
收费全文 | 109610篇 |
免费 | 5366篇 |
国内免费 | 5106篇 |
专业分类
化学 | 48917篇 |
晶体学 | 1235篇 |
力学 | 8193篇 |
综合类 | 352篇 |
数学 | 35288篇 |
物理学 | 26097篇 |
出版年
2023年 | 470篇 |
2022年 | 583篇 |
2021年 | 895篇 |
2020年 | 1122篇 |
2019年 | 1185篇 |
2018年 | 11229篇 |
2017年 | 10967篇 |
2016年 | 7366篇 |
2015年 | 2360篇 |
2014年 | 2164篇 |
2013年 | 2809篇 |
2012年 | 6554篇 |
2011年 | 13332篇 |
2010年 | 7783篇 |
2009年 | 8018篇 |
2008年 | 8957篇 |
2007年 | 10840篇 |
2006年 | 2246篇 |
2005年 | 3013篇 |
2004年 | 2998篇 |
2003年 | 3232篇 |
2002年 | 2309篇 |
2001年 | 1319篇 |
2000年 | 1140篇 |
1999年 | 840篇 |
1998年 | 692篇 |
1997年 | 611篇 |
1996年 | 592篇 |
1995年 | 472篇 |
1994年 | 449篇 |
1993年 | 400篇 |
1992年 | 342篇 |
1991年 | 284篇 |
1990年 | 240篇 |
1989年 | 229篇 |
1988年 | 153篇 |
1987年 | 140篇 |
1986年 | 133篇 |
1985年 | 113篇 |
1984年 | 93篇 |
1983年 | 64篇 |
1982年 | 70篇 |
1981年 | 60篇 |
1980年 | 72篇 |
1979年 | 52篇 |
1978年 | 49篇 |
1973年 | 43篇 |
1914年 | 45篇 |
1909年 | 41篇 |
1908年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
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
3.
4.
Hu Duo-Duo Gao Qian Dai Jing-Cheng Cui Ru Li Yuan-Bo Li Yuan-Ming Zhou Xiao-Guo Bian Kang-Jie Wu Bing-Bing Zhang Kai-Fan Wang Xi-Sheng Li Yan 《中国科学:化学(英文版)》2022,65(4):753-761
Science China Chemistry - A light-induced, nickel-catalyzed three-component arylsulfonation of 1,3-enynes in the absence of photocatalyst is reported. This methodology exhibited mild conditions,... 相似文献
5.
6.
Mengyuan Zhang Peiling Lin Xiaofan Song Kun Chen Yuxuan Yang Yongliang Xu Qiang Zhang Youshen Wu Yanfeng Zhang Yilong Cheng 《Journal of polymer science. Part A, Polymer chemistry》2022,60(9):1511-1520
The design of wound dressings with excellent self-healing ability, adequate adhesion, good biocompatibility, and potential antibacterial ability is of great significance for the healing of infected wounds arising from human activities. Herein, a series of multi-functional hydrogel dressings, poly(ionized isocyanoethyl methacrylate-glutamine)/poly(hexamethylene guanidine) (iGx/PHMGy) hydrogels, were obtained through homopolymerization of fully ionized isocyanoethyl methacrylate-glutamine (iIEM-Gln) in the presence of poly(hexamethylene guanidine) (PHMG), in which strong hydrogen bonds were formed among urea groups in the P (iIEM-Gln) chain to form a stable hydrogel network. The prepared iGx/PHMGy hydrogels exhibited adequate self-healing ability and tissue adhesion, which could be firmly adhered to the wound surface and remained intact during application. In addition, the presence of PHMG imparted good antibacterial activity to the hydrogels for the effective promotion of the wound healing in S. aureus infected skin wound on mice. Overall, this multi-functional hydrogel provides a facile and effective strategy for the design of infected wound dressings, and may show great potential in clinical applications. 相似文献
7.
Sicheng Yang Dr. Jiaoyu Ren Prof. Hong Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(7):e202103867
The drug delivery system based on nano/micromotors has become a research hot spot in recent years. However, naked micromotors may be ruptured or passivated under the complex biological environment, which will result in the leakage of drugs in advance or limited self-propulsion performance. Herein, an injectable micromotor@hydrogel drug delivery system to protect micromotors from the external environment is proposed. The micromotors were prepared through layer-by-layer assembly technology. The asymmetric decomposition of hydrogen peroxide catalyzed by the locally distributed platinum nanoparticles enabled efficient propulsion of the micromotors in low concentration of hydrogen peroxide. In order to protect micromotors, they were loaded into the Schiff base hydrogel. The micromotor@hydrogel system can be injected directly into the lesion to release micromotors in response to the environment, reducing external influence on micromotors and improving the sustained-release effect. Erythromycin (Ery) loaded into the micromotors and the micromotor@hydrogel system demonstrated excellent antibacterial effect. Micromotors released from the hydrogel underwent enhanced diffusion in the surroundings of bacteria without addition of exogenous hydrogen peroxide, which was manifested by their appearance in edge of the inhibition zone. The proposed micromotor@hydrogel drug delivery system offers a new strategy for the treatment of bacterial infections. 相似文献
8.
Hanghang Zhou Dr. Ying Luo Dr. Jun Xu Dr. Lidan Deng Prof. Dr. Zheng Wang Prof. Dr. Hong He 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(68):e202202044
Cubic-like CaTaO2N photocatalysts with high crystallinity and uniform particle size were successfully prepared by the flux-assisted nitridation method. The growth of CaTaO2N single crystals under different synthesis conditions was systematically investigated to understand the effects of the crystallinity and optical property on photocatalytic performance of CO2 reduction. Moreover, the modification of CaTaO2N single crystals with core-shell Ni−Ag bicomponent cocatalyst by two-step decoration process gave a 2.4 times higher amount of CO evolution than the deposition of sole Ag cocatalyst, because of the synergistic effects of bicomponent cocatalyst on the interfacial electron transfer and surface catalytic process. This study provides a valuable way to construct high-crystalline photocatalysts with effective bicomponent cocatalyst for visible-light-driven CO2 reduction with H2O. 相似文献
9.
Ye Jingyao Al-Jobory Alaa Zhang Qian-Chong Cao Wenqiang Alshehab Abdullah Qu Kai Alotaibi Turki Chen Hang Liu Junyang Ismael Ali K. Chen Zhong-Ning Lambert Colin J. Hong Wenjing 《中国科学:化学(英文版)》2022,65(9):1822-1828
Science China Chemistry - Destructive quantum interference (DQI) provides a unique approach to controlling the leakage current in the OFF state of molecular devices. However, the DQI in... 相似文献
10.
Zhang Mingjie Song Yang Abdelkefi Abdessattar Yu Haiyan Wang Junlei 《Nonlinear dynamics》2022,108(3):1867-1884
Nonlinear Dynamics - Vortex-induced vibration (VIV) systems with stiffness nonlinearity have received increasing attention because the stiffness nonlinearity can broaden the effective flow velocity... 相似文献