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91.
92.
Electrodeposition and characterization of Zn–Sn alloy coatings from a deep eutectic solvent based on choline chloride for corrosion protection 下载免费PDF全文
S. Fashu C. D. Gu J. L. Zhang W. Q. Bai X. L. Wang J. P. Tu 《Surface and interface analysis : SIA》2015,47(3):403-412
With the aim of obtaining high corrosion resistant Zn–Sn alloy coatings from an ionic liquid, the effects of electrodeposition potential and electrolyte composition on the electrodeposition behavior, film composition, morphology and corrosion performance were investigated. Cyclic voltammograms indicate that Zn and Sn were co‐deposited at distinct reduction potentials as pure Zn and Sn elements. In addition, the phase composition analysis also showed that the obtained Zn–Sn alloy deposits (8 wt.%–45 wt.% Zn) consist of a two‐phase mechanical mixture of small aggregates of Zn and Sn metals. The Zn content of the alloy significantly increases as the electrodeposition potential and electrolyte Zn (II)/Sn (II) ratio increase. The corrosion performance study of the obtained Zn–Sn coatings showed that they have a passivation behavior and their corrosion resistance increases as the alloy‐Sn content increases. To improve their morphological properties, ethylene diamine tetraacetic acid additive was introduced into the electrolyte and greatly improved the morphology and corrosion resistance of the deposits. For the first time, it was shown that high corrosion resistance Zn–Sn coatings can be obtained from ionic liquids. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
93.
Qing-Qing Guan Xiao-Dian Huang Yan-Hua Zeng Chao-Hai Wei Ping Ning Gu Jun-Jie Xin-Sheng Chai 《Chemical Papers》2015,69(5):662-667
This paper reports a headspace analysis technique for the determination of products, i.e., cyclohexanone (CE) and cyclohexanol (CL), of phenol hydrogenation in a supercritical water reaction system (SWRS) with water removal by hydrate formation. An addition of anhydrous calcium chloride leads to water absorption resulting in crystal water; thus, the samples can be quantitatively measured without the influence of water. After achieving equilibrium at 150°C and maintaining it for 5 min, the obtained results showed a relative standard deviation of less than 5.3% and the recovery ranged from 93% to 104%. The presented method is simple and accurate for the analysis of CL, CE and phenol in samples from phenol conversion in SWRS. 相似文献
94.
95.
将PEG/PAA凝胶浸入铁/柠檬酸(Fe3+/CA)溶液中,自然光照一定时间可实现凝胶-溶胶的相互转化,而且转化行为受溶液的组成及其p H影响。只有当溶液中[Fe3+]0∶[CA]0≤1∶2,且溶液的p H在1~6之间,该转化才会发生,通过改变溶液中[Fe3+]0∶[CA]0的值或溶液的p H可以有效地控制其转化速率。此外,结果还表明,当凝胶转化为溶胶后,向其中加入高价金属阳离子,例如Fe3+、Al3+、Ce4+、Cu2+等,溶胶又会再次转化为凝胶。由于这种新颖的特性,该凝胶有望应用于药物释放、细胞培养等领域。 相似文献
96.
Laurine Gonnard Dr. Amandine Guérinot Prof. Janine Cossy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(36):12797-12803
A cobalt‐catalyzed cross‐coupling between 3‐ and 4‐iodopiperidines and Grignard reagents is disclosed. The reaction is an efficient, cheap, chemoselective, and flexible way to functionalize piperidines. This coupling was used as the key step to realize a short synthesis of (±)‐preclamol. Some mechanistic investigations were conducted that highlight the formation of radical intermediates. 相似文献
97.
Prof. Dr. Li‐Jun Gu Cheng Jin Hong‐Tao Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(24):8741-8744
A novel nickel N‐heterocyclic carbene catalyzed cross‐coupling reaction of aryl aldehydes with boronic esters for the synthesis of aryl ketones was developed. This reaction provides a mild, practical method toward aryl ketones, which are versatile intermediates and building blocks in organic synthesis. 相似文献
98.
Dr. Kimiaka C. Guérard Vincent Hamel Dr. Amandine Guérinot Cloé Bouchard‐Aubin Prof. Sylvain Canesi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(50):18068-18071
A rapid route to 5,5‐ and 5,6‐ bicyclic systems is provided by an 1,3‐alkyl‐shift process mediated by a hypervalent iodine reagent on aromatics. The structures obtained contain several unsaturations with different behaviors and reactivities. Such diversity allows further elaborations for the rapid formation of compact systems present in a variety of natural products. The potential for further transformations has been demonstrated by performing a double Michael addition. This cyclization process is regio‐ and stereoselective due to the presence of a former benzylic substituent. Furthermore, an extension of this approach has been accomplished on indole derivatives. 相似文献
99.
Fluorescent Coumarin–Artemisinin Conjugates as Mitochondria‐Targeting Theranostic Probes for Enhanced Anticancer Activities 下载免费PDF全文
Dr. Xu Zhang Qian Ba Zhanni Gu Dr. Diliang Guo Prof. Yu Zhou Prof. Yungen Xu Prof. Hui Wang Prof. Deju Ye Prof. Hong Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(48):17415-17421
Mitochondria‐targeting theranostic probes that enable the simultaneously reporting of and triggering of mitochondrial dysfunctions in cancer cells are highly attractive for cancer diagnosis and therapy. Three fluorescent mitochondria‐targeting theranostic probes have been developed by linking a mitochondrial dye, coumarin‐3‐carboximide, with a widely used traditional Chinese medicine, artemisinin, to kill cancer cells. Fluorescence images showed that the designed coumarin–artemisinin conjugates localized mainly in mitochondria, leading to enhanced anticancer activities over artemisinin. High cytotoxicity against cancer cells correlated with the strong ability to accumulate in mitochondria, which could efficiently increase the intracellular reactive oxygen species level and induce cell apoptosis. This study highlights the potential of using mitochondria‐targeting fluorophores to selectively trigger and directly visualize subcellular drug delivery in living cells. 相似文献
100.
Remote Construction of Chiral Vicinal Tertiary and Quaternary Centers by Catalytic Asymmetric 1,6‐Conjugate Addition of Prochiral Carbon Nucleophiles to Cyclic Dienones 下载免费PDF全文
Yuan Wei Zunwu Liu Xinxin Wu Jie Fei Xiaodong Gu Xiaoqian Yuan Prof. Dr. Jinxing Ye 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(52):18921-18924
An unprecedented remote construction of chiral vicinal tertiary and quaternary centers by a catalytic asymmetric 1,6‐conjugate addition of prochiral carbon nucleophiles to cyclic dienones has been developed. Both 5H‐oxazol‐4‐ones and 2‐oxindoles were found to be very efficient carbon nucleophiles in this reaction at a remote position, giving products with excellent enantio‐ and diastereoselectivities (up to 99 % ee and >19:1 d.r. for 5H‐oxazol‐4‐ones and up to 97 % ee and >19:1 d.r. for 2‐oxindoles). 相似文献