全文获取类型
收费全文 | 43406篇 |
免费 | 18124篇 |
国内免费 | 61篇 |
专业分类
化学 | 55546篇 |
晶体学 | 66篇 |
力学 | 2074篇 |
数学 | 2660篇 |
物理学 | 1245篇 |
出版年
2024年 | 373篇 |
2023年 | 4086篇 |
2022年 | 1462篇 |
2021年 | 2494篇 |
2020年 | 4628篇 |
2019年 | 2319篇 |
2018年 | 2279篇 |
2017年 | 611篇 |
2016年 | 5584篇 |
2015年 | 5526篇 |
2014年 | 4959篇 |
2013年 | 5152篇 |
2012年 | 3218篇 |
2011年 | 1055篇 |
2010年 | 3426篇 |
2009年 | 3374篇 |
2008年 | 1033篇 |
2007年 | 756篇 |
2006年 | 114篇 |
2005年 | 96篇 |
1997年 | 90篇 |
1996年 | 86篇 |
1995年 | 147篇 |
1994年 | 87篇 |
1993年 | 217篇 |
1992年 | 99篇 |
1988年 | 117篇 |
1987年 | 103篇 |
1985年 | 100篇 |
1984年 | 109篇 |
1983年 | 103篇 |
1982年 | 130篇 |
1981年 | 155篇 |
1980年 | 196篇 |
1979年 | 185篇 |
1978年 | 191篇 |
1977年 | 311篇 |
1976年 | 362篇 |
1975年 | 456篇 |
1974年 | 471篇 |
1973年 | 284篇 |
1972年 | 369篇 |
1971年 | 355篇 |
1970年 | 541篇 |
1969年 | 413篇 |
1968年 | 457篇 |
1967年 | 114篇 |
1966年 | 89篇 |
1965年 | 83篇 |
1963年 | 112篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
891.
Prof. Dr. Heinz Langhals Dr. Bernd Böck M. Sc. Tanja Schmid Alexey Marchuk 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(41):13188-13194
Benzoperylene derivatives with two angularly attached dicarboxylic imide rings, which were prepared by the Diels–Alder‐Reaction, exhibit strong fluorescence and their free peri positions allow either control of the UV/Vis spectra through their substituents or form anchor positions for the attachment of functional units. The angular chromophore 3 may be used both for fluorescent labeling such as for primary amines or enzymes or as building blocks for more complex assemblies where they may act as energy donors for FRET or electron acceptors in PET such as for photovoltaic solar cells. 相似文献
892.
Dr. Adam A. Sobczuk Dr. Youichi Tsuchiya Dr. Tomohiro Shiraki Dr. Shun‐ichi Tamaru Prof. Seiji Shinkai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(10):2832-2838
A unique class of oligothiophene‐based organogelator bearing two crown ethers at both ends was synthesized. This compound could gelatinize several organic solvents, forming one‐dimensional fibrous aggregates. From the observation of circular dichroism, it was confirmed that the helical handedness of the fibrous assembly is controllable by the chirality of 1,2bisammonium guests, thus suggesting that one guest molecule bridges two gelator molecules through the crown–ammonium interaction. Interestingly, we have found that such chirality is created by thermal gelation, whereas it disappears by thixotropic gelation. The new finding implies that the present organogel system is applicable as a reversible switching memory device, featuring memory creation by a heat mode and memory erasing by a mechanical mode. 相似文献
893.
894.
Dr. James Biggs Dr. Karsten Danielmeier Dr. Julia Hitzbleck Dr. Jens Krause Tom Kridl Dr. Stephan Nowak Dr. Enrico Orselli Dr. Xina Quan Dirk Schapeler Will Sutherland Dr. Joachim Wagner 《Angewandte Chemie (International ed. in English)》2013,52(36):9409-9421
We present the development and applications of dielectric elastomers. For the last 10 years the significance of this class of polymers has risen as more applications seem possible and first products have been commercialized. 相似文献
895.
Dr. Manuel Moliner Prof. Fernando Rey Prof. Avelino Corma 《Angewandte Chemie (International ed. in English)》2013,52(52):13880-13889
Zeolites are crystalline microporous materials with application in diverse fields, especially in catalysis. The ability to prepare zeolites with targeted physicochemical properties for a specific catalytic application is a matter of great interest, because it allows the efficiency of the entire chemical process to be increased (higher product yields, lower undesired by‐products, less energy consumption, and cost savings, etc). Nevertheless, directing the zeolite crystallization towards the material with the desired framework topology, crystal size, or chemical composition is not an easy task, since several variables influence the nucleation and crystallization processes. The combination of accumulated knowledge, rationalization, and innovation has allowed the synthesis of unique zeolitic structures in the last few years. This is especially true in terms of the design of organic and inorganic structure‐directing agents (SDAs). In this Minireview we will present the rationale we have followed in our studies to synthesize new zeolite structures, while putting this in perspective with the advances made by other researchers of the zeolite community. 相似文献
896.
Eden E. L. Tanner Dr. Christopher Batchelor‐McAuley Prof. Dr. Richard G. Compton 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(17):5976-5981
Herein, we report a change in the mechanism of the oxidation of silver nanoparticles (Ag NPs) with the molecular weight of a poly(ethylene) glycol (PEG) capping agent. Characterisation of the modified nanoparticles is undertaken using dynamic light scattering and UV/Vis spectroscopy. Electrochemical analyses reveal that the oxidation of 6000 molecular weight (MW) PEG is consistent with a polymer‐gated mechanism, whilst for 2000 MW PEG the polymer does not hinder the oxidation. The 10,000 MW PEG Ag NPs are rendered almost electrochemically inactive. This study demonstrates the ability to alter and better understand the electron‐transfer mechanism in a room temperature ionic liquid (RTIL) by systematically altering the capping agent. 相似文献
897.
Modification of σ‐Donor Properties of Terminal Carbide Ligands Investigated Through Carbide–Iodine Adduct Formation
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)
Anders Reinholdt Prof. Dr. Tom Vosch Prof. Dr. Jesper Bendix 《Angewandte Chemie (International ed. in English)》2016,55(40):12484-12487
The terminal carbide ligands in [(Cy3P)2X2Ru≡C] complexes (X=halide or pseudohalide) coordinate molecular iodine, affording charge‐transfer complexes rather than oxidation products. Crystallographic and vibrational spectroscopic data show the perturbations of iodine to vary with the auxiliary ligand sphere on ruthenium, demonstrating the σ‐donor properties of carbide complexes to be tunable. 相似文献
898.
Inside Cover: Stapled Peptides with γ‐Methylated Hydrocarbon Chains for the Estrogen Receptor/Coactivator Interaction (Angew. Chem. Int. Ed. 13/2016)
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)
899.
900.