全文获取类型
收费全文 | 46415篇 |
免费 | 7810篇 |
国内免费 | 5485篇 |
专业分类
化学 | 32538篇 |
晶体学 | 536篇 |
力学 | 2890篇 |
综合类 | 389篇 |
数学 | 5554篇 |
物理学 | 17803篇 |
出版年
2024年 | 34篇 |
2023年 | 929篇 |
2022年 | 968篇 |
2021年 | 1488篇 |
2020年 | 1945篇 |
2019年 | 1790篇 |
2018年 | 1572篇 |
2017年 | 1446篇 |
2016年 | 2157篇 |
2015年 | 2137篇 |
2014年 | 2641篇 |
2013年 | 3407篇 |
2012年 | 4333篇 |
2011年 | 4323篇 |
2010年 | 3022篇 |
2009年 | 2868篇 |
2008年 | 3114篇 |
2007年 | 2741篇 |
2006年 | 2493篇 |
2005年 | 2069篇 |
2004年 | 1718篇 |
2003年 | 1297篇 |
2002年 | 1156篇 |
2001年 | 980篇 |
2000年 | 861篇 |
1999年 | 952篇 |
1998年 | 787篇 |
1997年 | 725篇 |
1996年 | 783篇 |
1995年 | 680篇 |
1994年 | 634篇 |
1993年 | 527篇 |
1992年 | 507篇 |
1991年 | 417篇 |
1990年 | 378篇 |
1989年 | 273篇 |
1988年 | 244篇 |
1987年 | 214篇 |
1986年 | 157篇 |
1985年 | 179篇 |
1984年 | 150篇 |
1983年 | 129篇 |
1982年 | 91篇 |
1981年 | 65篇 |
1980年 | 50篇 |
1979年 | 34篇 |
1978年 | 27篇 |
1976年 | 28篇 |
1975年 | 32篇 |
1974年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
11.
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
12.
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
13.
Science China Chemistry - Human health is always under global spotlight, but now it suffers from severe environmental issue and various diseases. Developing highly selective and effective... 相似文献
14.
Haicun Yang Shuipi Cai Yu Jiang Zheng Cao Wenzhong Ma Fanghong Gong Guoliang Tao Chunlin Liu 《Journal of polymer science. Part A, Polymer chemistry》2022,60(10):1571-1587
The commonly used multi-center initiation methods always lead to the formation of quantities of homopolymer in the surface tailoring based on reverse atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain-transfer (RAFT) polymerization. In this study, a monocenter redox pair constructed of silica bearing tert-butyl hydroperoxide groups and ascorbic acid (SiO2-TBHP/AsAc) was applied to substitute the commonly used initiation method of R-supported RAFT grafting polymerization. All the propagating radicals were restricted on the surface of solid particles during the whole procedure theoretically, resulting in a higher grafting efficiency of 95.1% combined with the “controllable” feature at 10 h. This redox pair was also used to initiate the reverse ATRP in miniemulsion successfully with a grafting efficiency of 86.3% at 10 h. The grafting efficiency obtained under this monocenter initiation method was significantly higher than that of the frequently reported surface modification by reverse ATRP and RAFT polymerization. In addition, the high-efficient surface tailoring was traced and confirmed by nuclear magnetic resonance, Fourier transform infrared, X-ray photoelectron spectroscopy, thermogravimetric analysis, transmission electron microscopy, and other analysis tests. The advantage of this monocenter redox pair will open a new avenue for the potential “high-efficient” surface tailoring of various materials. 相似文献
15.
Nonlinear Dynamics - Epilepsy is the second largest neurological disease which seriously threatens human life and health. The one important reason of inducing epileptic seizures is ischemic stroke... 相似文献
16.
BIT Numerical Mathematics - In this paper, we introduce a novel class of embedded exponential-type low-regularity integrators (ELRIs) for solving the KdV equation and establish their optimal... 相似文献
17.
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
18.
Tingrui Li Yilitabaier Julaiti Xiaopeng Wu Jie Han Dr. Jin Xie 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(71):e202202851
The gold-catalyzed ring-opening rearrangement of cyclopropenes affords an efficient route to either polysubstituted naphthols or aryl-substituted furans. Owing to the unique dichotomy of gold−carbenes, this protocol provides a switchable reaction selectivity between naphthols and furans enabled by the use of TFP−Au(MeCN)SbF6 (tri(2-furyl) phosphine) or PNP(AuNTf2)2 (bis(diphenylphosphino)(isopropyl) amine) as catalysts respectively. It is proposed that the gold−carbene intermediate might be involved in the cyclopropene→naphthol rearrangement while the gold-carbocation is more likely to be involved in the cyclopropene→furan rearrangement. 相似文献
19.
20.
Feng Cheng Shuqi Wu Wenwei Zheng Shengqun Su Takumi Nakanishi Wenhuang Xu Pritam Sadhukhan Hibiki Sejima Shimon Ikenaga Kaoru Yamamoto Kaige Gao Shinji Kanegawa Prof. Osamu Sato 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(59):e202202161
The crystallization of a complex having electron transfer properties in a polar space group can induce the polarization switching of a crystal in a specific direction, which is attractive for the development of sensors, memory devices, and capacitors. Unfortunately, the probability of crystallization in a polar space group is usually low. Noticing that enantiopure compounds crystallize in Sohncke space groups, this paper reports a strategy for the molecular design of non-ferroelectric polarization switching crystals based on the use of intramolecular electron transfer and chirality. In addition, this paper describes the synthesis of a mononuclear valence tautomeric (VT) cobalt complex bearing an enantiopure ligand. The introduction of enantiomer enables the crystallization of the complex in the polar space group (P21). The polarization of the crystals along the b-axis direction is not canceled out and the VT transition is accompanied by a change in the macroscopic polarization of the polar crystal. Polarization switching via electron transfer is realized at around room temperature. 相似文献