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51.
Enhanced Photocatalytic Reduction of CO2 to CO through TiO2 Passivation of InP in Ionic Liquids 下载免费PDF全文
Guangtong Zeng Jing Qiu Bingya Hou Haotian Shi Dr. Yongjing Lin Mark Hettick Prof. Ali Javey Prof. Stephen B. Cronin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(39):13502-13507
A robust and reliable method for improving the photocatalytic performance of InP, which is one of the best known materials for solar photoconversion (i.e., solar cells). In this article, we report substantial improvements (up to 18×) in the photocatalytic yields for CO2 reduction to CO through the surface passivation of InP with TiO2 deposited by atomic layer deposition (ALD). Here, the main mechanisms of enhancement are the introduction of catalytically active sites and the formation of a pn‐junction. Photoelectrochemical reactions were carried out in a nonaqueous solution consisting of ionic liquid, 1‐ethyl‐3‐methylimidazolium tetrafluoroborate ([EMIM]BF4), dissolved in acetonitrile, which enables CO2 reduction with a Faradaic efficiency of 99 % at an underpotential of +0.78 V. While the photocatalytic yield increases with the addition of the TiO2 layer, a corresponding drop in the photoluminescence intensity indicates the presence of catalytically active sites, which cause an increase in the electron‐hole pair recombination rate. NMR spectra show that the [EMIM]+ ions in solution form an intermediate complex with CO2?, thus lowering the energy barrier of this reaction. 相似文献
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Mingliang Zhang Abul K. Mallik Makoto Takafuji Hirotaka Ihara Hongdeng Qiu 《Analytica chimica acta》2015
Ionic liquids (ILs), a class of unique substances composed purely by cation and anions, are renowned for their fascinating physical and chemical properties, such as negligible volatility, high dissolution power, high thermal stability, tunable structure and miscibility. They are enjoying ever-growing applications in a great diversity of disciplines. 相似文献
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Zhi-Chao Liu Jian-Wen QiChun Hu Li ZhangWei Song Ru-Ping LiangJian-Ding Qiu 《Analytica chimica acta》2015
Copper is a highly toxic environmental pollutant with bioaccumulative properties. Therefore, sensitive detection of Cu2+ is very important to prevent over-ingestion, and visual detection is preferred for practical applications. In this work, we developed a simple and environmental friendly approach to synthesize hyperbranched polyethyleneimine-protected copper nanoclusters (hPEI-Cu NCs) with great stability against extreme pH, high ionic strength, thiols etching and light illumination, which were then conjugated to the surface of silica coated CdSe quantum dots (QDs) to design a ratiometric fluorescence probe. In the presence of different amounts of Cu2+ ions, the fluorescence of Cu NCs can be drastically quenched, while the emission from QDs stayed constant to serve as a reference signal and the color of the probe changed from yellow-green to red, resulting in ratiometric and visualization detection of Cu2+ ion with high accuracy. The detection limit for Cu2+ was estimated to be 8.9 nM, much lower than the allowable level of Cu2+ in drinking water (∼20 μM) set by U.S. Environmental Protection Agency. Additionally, this probe can be also applied for the determination of Cu2+ ion in complex real water samples. 相似文献
55.
Facile Synthesis of the Pentasaccharide Repeating Unit of the Exopolysaccharide from Cryptococcus neoformans Serotype D 下载免费PDF全文
Sheng‐Jun Huang Jun Liao Hong‐Gang Hu Qing‐Jie Zhao Qiu‐Ye Wu 《Helvetica chimica acta》2015,98(5):618-626
β‐D ‐GlcpA‐(1→2)‐[β‐D ‐Xylp‐(1→2)‐α‐D ‐Manp‐(1→3)]‐α‐D ‐Manp‐(1→3)‐α‐D ‐Manp, the repeating unit of the exopolysaccharide from Cryptococcus neoformans serotype D, was synthesized as its 4‐methoxyphenyl glycoside. The approach presented here also provides a route to the synthesis of more complex repeating units of glucuconoxylomannan (GXM) of C. neoformans serotypes A–C. 相似文献
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Capillary electrophoretic studies on quantum dots and histidine appended peptides self‐assembly 下载免费PDF全文
Jianhao Wang Jingyan Li Yao Chen Yiwan Teng Cheli Wang Jinchen Li Li Liu Bingyu Dong Lin Qiu Pengju Jiang 《Electrophoresis》2015,36(19):2419-2424
Herein, we designed four peptides appended with different numbers of histidine (Hisn‐peptide). We launched a systematic investigation on quantum dots (QDs) and Hisn‐peptide self‐assembly in solution using fluorescence coupled CE (CE‐FL). The results indicated that CE‐FL was a powerful method to probe how ligands interaction on the surface of nanoparticles. The self‐assembly of QDs and peptide was determined by the numbers of histidine. We also observed that longer polyhistidine tags (n ≤ 6) could improve the self‐assembly efficiency. Furthermore, the formation and separation of QD‐peptide assembly were also studied by CE‐FL inside a capillary. The total time for the mixing, self‐assembly, separation, and detection was less than 10 min. Our method greatly expands the application of CE‐FL in QDs‐based biolabeling and bioanalysis. 相似文献
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Feng‐Yang Bai Xiao‐Le Zhu Zi‐Man Jia Xu Wang Yan‐Qiu Sun Prof. Rong‐Shun Wang Prof. Xiu‐Mei Pan 《Chemphyschem》2015,16(8):1768-1776
The mechanism and kinetics of the reactions of CF3COOCH2CH3, CF2HCOOCH3, and CF3COOCH3 with Cl and OH radicals are studied using the B3LYP, MP2, BHandHLYP, and M06‐2X methods with the 6‐311G(d,p) basis set. The study is further refined by using the CCSD(T) and QCISD(T)/6‐311++G(d,p) methods. Seven hydrogen‐abstraction channels are found. All the rate constants, computed by a dual‐level direct method with a small‐curvature tunneling correction, are in good agreement with the experimental data. The tunneling effect is found to be important for the calculated rate constants in the low‐temperature range. For the reaction of CF3COOCH2CH3+Cl, H‐abstraction from the CH2 group is found to be the dominant reaction channel. The standard enthalpies of formation for the species are also calculated. The Arrhenius expressions are fitted within 200–1000 K as kT(1)=8.4×10?20T 2.63exp(381.28/T), kT(2)=2.95×10?21T 3.13exp(?103.21/T), kT(3)=1.25×10?23T 3.37exp(791.98/T), and kT(4)=4.53×10?22T 3.07exp(465.00/T). 相似文献