全文获取类型
收费全文 | 571篇 |
免费 | 83篇 |
国内免费 | 121篇 |
专业分类
化学 | 670篇 |
晶体学 | 8篇 |
力学 | 14篇 |
综合类 | 4篇 |
物理学 | 79篇 |
出版年
2024年 | 2篇 |
2023年 | 14篇 |
2022年 | 26篇 |
2021年 | 37篇 |
2020年 | 46篇 |
2019年 | 45篇 |
2018年 | 29篇 |
2017年 | 46篇 |
2016年 | 39篇 |
2015年 | 27篇 |
2014年 | 41篇 |
2013年 | 61篇 |
2012年 | 32篇 |
2011年 | 25篇 |
2010年 | 18篇 |
2009年 | 30篇 |
2008年 | 25篇 |
2007年 | 20篇 |
2006年 | 28篇 |
2005年 | 25篇 |
2004年 | 28篇 |
2003年 | 24篇 |
2002年 | 9篇 |
2001年 | 9篇 |
2000年 | 10篇 |
1999年 | 12篇 |
1998年 | 11篇 |
1997年 | 8篇 |
1996年 | 2篇 |
1995年 | 7篇 |
1994年 | 11篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有775条查询结果,搜索用时 31 毫秒
131.
Issa Yavari Nargess Hosseini Loghman Moradi Anvar Mirzaei 《Tetrahedron letters》2008,49(27):4239-4241
A mild, convenient, and practical one-pot procedure for direct synthesis of N,N′-dialkyl-N″-dialkylaminocarbothioyl thioureas is described via three-component reaction of cyclic secondary amines, CS2, and N,N′-dialkyl carbodiimides in water at room temperature. 相似文献
132.
N-甲基-2-单芳基苯并噻唑啉 (1) 在固体状态时可以稳定地储藏在空气中。但是,它们在不同溶剂中却表现出了不同的行为。在醇溶液或二甲亚砜-水的体系中,1相对稳定;而在其它有机溶剂如:丙酮,氯仿,二氯甲烷和乙酸乙酯等溶剂中,会发生自发偶联反应生成相应的邻-(N-芳酰基-N-甲氨基苯)-二硫化合物 (2)。对这些新的化合物 (1) 和 (2) 进行了体外人乳腺癌细胞 (MDA-MB-231) 血管内皮生长因子靶点筛选,大部分化合物都表现出了抑制活性。实验结果表明这两类化合物 (1) 和 (2) 作为血管内皮生长因子抑制剂值得进行深入研究。 相似文献
133.
Yang D Liu GJ Jiao ZG Zhang DW Luo Z Song KS Chen MQ 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(33):10297-10302
Disulfide-bond formation between the side chains of cysteine-cysteine pairs is often critical to the folding behavior, stability, and functionality of proteins. In this paper, we report that sulfur atoms can be introduced into the amide groups of aminoxy peptides to form a novel type of disulfide bridge, which creates a connecting loop in the peptide backbone. 相似文献
134.
135.
Alexandra R. E. Serre Gabriel C. Nwokolo Dr. Hannah L. M. Spencer Timothy J. Bell Dr. Francis M. Barnieh Laurie Hughes Prof. Robert A. Falconer Dr. Goreti Ribeiro Morais 《European journal of organic chemistry》2023,26(38):e202300789
Cyclic peptides are important molecules, playing key roles in protein architecture, as chemical probes, and increasingly as crucial structural elements of clinically-useful therapeutics. Herein we report methodology using azodicarboxylates as efficient reagents for the facile synthesis of cyclic peptides through a disulfide bridge. The utility of this approach in both solution and solid-phase, and compatibility with common amino acid side chain functionalities is demonstrated, resulting in cyclic peptides in good yield and purity. This approach has significant potential application for synthesis of molecules of biological or therapeutic significance. 相似文献
136.
《Arabian Journal of Chemistry》2023,16(5):104613
A tin disulfide and multi-walled carbon nanotube (SnS2/CNTs) electrochemical sensor was constructed for the sensitive and selective determination of rutin in plants. Tin disulfide nanoflowers with various particle sizes were prepared by controlling the reaction time and composited with multi-walled CNTs. The morphology, crystal structure, and chemical composition of these SnS2/CNTs composites were characterized using XRD, XPS, and SEM-EDS. Results illustrated that the SnS2/CNTs had a large specific surface area, good conductivity, and remarkable electrocatalytic performance. The pH of the buffer solution, the scanning rate, and the amount of modified material were also optimized for the rapid detection of rutin. A 2-electron-2-proton mechanism, involving a few rapid and consecutive stages, was speculated to occur during rutin oxidation, based on the observed slope of -53 mV/pH. There was an appreciable linear relationship between the reductive peak current from DPV and the rutin concentration, ranging from 0.005-0.05 µmol/L and 0.1-6 µmol/L, with a detection limit of 0.22 nmol/L (S/N = 3). The sensor also demonstrated good selectivity, excellent sensitivity, and reproducibility when analyzing rutin in real plant samples, with satisfactory recovery, and was also highly consistent with results of HPLC, and thus could be used to evaluate the medicinal value of natural vegetation. 相似文献
137.
Site‐Selective Disulfide Modification of Proteins: Expanding Diversity beyond the Proteome
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Seah Ling Kuan Dr. Tao Wang Prof. Dr. Tanja Weil 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(48):17112-17129
The synthetic transformation of polypeptides with molecular accuracy holds great promise for providing functional and structural diversity beyond the proteome. Consequently, the last decade has seen an exponential growth of site‐directed chemistry to install additional features into peptides and proteins even inside living cells. The disulfide rebridging strategy has emerged as a powerful tool for site‐selective modifications since most proteins contain disulfide bonds. In this Review, we present the chemical design, advantages and limitations of the disulfide rebridging reagents, while summarizing their relevance for synthetic customization of functional protein bioconjugates, as well as the resultant impact and advancement for biomedical applications. 相似文献
138.
Interface Engineering of MoS2/Ni3S2 Heterostructures for Highly Enhanced Electrochemical Overall‐Water‐Splitting Activity
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Jian Zhang Dr. Tao Wang Dr. Darius Pohl Dr. Bernd Rellinghaus Dr. Renhao Dong Dr. Shaohua Liu Dr. Xiaodong Zhuang Prof. Xinliang Feng 《Angewandte Chemie (International ed. in English)》2016,55(23):6702-6707
To achieve sustainable production of H2 fuel through water splitting, low‐cost electrocatalysts for the hydrogen‐evolution reaction (HER) and the oxygen‐evolution reaction (OER) are required to replace Pt and IrO2 catalysts. Herein, for the first time, we present the interface engineering of novel MoS2/Ni3S2 heterostructures, in which abundant interfaces are formed. For OER, such MoS2/Ni3S2 heterostructures show an extremely low overpotential of ca. 218 mV at 10 mA cm?2, which is superior to that of the state‐of‐the‐art OER electrocatalysts. Using MoS2/Ni3S2 heterostructures as bifunctional electrocatalysts, an alkali electrolyzer delivers a current density of 10 mA cm?2 at a very low cell voltage of ca. 1.56 V. In combination with DFT calculations, this study demonstrates that the constructed interfaces synergistically favor the chemisorption of hydrogen and oxygen‐containing intermediates, thus accelerating the overall electrochemical water splitting. 相似文献
139.
Two‐Dimensional Core‐Shelled Porous Hybrids as Highly Efficient Catalysts for the Oxygen Reduction Reaction
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Kai Yuan Dr. Xiaodong Zhuang Haiyan Fu Dr. Gunther Brunklaus Dr. Michael Forster Prof. Dr. Yiwang Chen Prof. Dr. Xinliang Feng Prof. Dr. Ullrich Scherf 《Angewandte Chemie (International ed. in English)》2016,55(24):6858-6863
Two‐dimensional (2D) transition‐metal dichalcogenides (TMDs) have drawn much attention due to their unique physical and chemical properties. Using TMDs as templates for the generation of 2D sandwich‐like materials with remarkable properties still remains a great challenge due to their poor solvent processability. Herein, MoS2‐coupled sandwich‐like conjugated microporous polymers (M‐CMPs) with high specific surface area were successfully developed by using functionalized MoS2 nanosheets as template. As‐prepared M‐CMPs were further used as precursors for preparation of MoS2‐embedded nitrogen‐doped porous carbon nanosheets, which were revealed as novel electrocatalysts for oxygen reduction reaction with mainly four‐electron transfer mechanism and ultralow half‐wave potential in comparison with commercial Pt/C catalyst. Our strategy to core–shelled sandwich‐like hybrids paves a way for a new class of 2D hybrids for energy conversion and storage. 相似文献
140.