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951.
Prof. Shuichi Nakamura Daiki Hayama 《Angewandte Chemie (International ed. in English)》2017,56(30):8785-8789
The first highly enantioselective nucleophilic addition reaction of phosphites with 2H-azirines has been developed. The reaction was applied to various 3-substituted 2H-azirines using novel chiral bis(imidazoline)/ZnII catalysts to afford products in good yield with high enantioselectivity. The transformation of the obtained optically active aziridines showed that 2H-azirines act as either α,β- or β,β-dicarbocationic amine synthons. 相似文献
952.
Corey S. Keenan 《合成通讯》2017,47(11):1085-1089
Nitroarenes are reduced to the corresponding aniline derivatives using iron or zinc under mild conditions under microwave heating conditions. Mild acidity is provided by ammonium chloride in an aqueous methanol medium. The conditions are tolerant to other functional groups, with the exception of bromoalkyl derivatives, which yield complex reaction mixtures; otherwise, yields are generally quite high (80–99%). 相似文献
953.
954.
We provide an overview of ZnO applications in solar cells. ZnO (and ZnO‐based materials) can be used as electrodes and/or scattering/light trapping layers, as well as electron transport layers in solar cells based on nanoparticles and organic materials (polymer solar cells, dye‐sensitized solar cells). For each of these applications, we will briefly summarize common research directions, as well as existing problems and unresolved questions. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
955.
Cadmium zinc sulphide thin films with high charge mobilities are obtained from acidic chemical baths employing the corresponding metal chlorides, urea and thioacetamide. The films are characterized by powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, inductively coupled plasma mass spectrometry, absorption spectroscopy and charge transport measurements. The compositional control afforded by the technique and the resultant changes in the structural, optical and electronic properties of the films are critically examined. We find good correlation between structure and properties at extremes of the composition range. 相似文献
956.
Xinyu Lu Weihong Zhu Prof. Dr. Yongshu Xie Prof. Dr. Xin Li Yuan Gao Fuyou Li Prof. Dr. He Tian Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(28):8355-8364
Near‐IR (NIR) emission can offer distinct advantages for both in vitro and in vivo biological applications. Two NIR fluorescent turn‐on sensors N,N′‐di‐n‐butyl‐2‐(N‐{2‐[bis(pyridin‐2‐ylmethyl)amino]ethyl})‐6‐(N‐piperidinyl)naphthalene‐1,4,5,8‐tetracarboxylic acid bisimide and N,N′‐di‐ n‐butyl‐2‐[N,N,N′‐tri(pyridin‐2‐ylmethyl)amino]ethyl‐6‐(N‐piperidinyl)naphthalene‐1,4,5,8‐tetracarboxylic acid bisimide (PND and PNT) for Zn2+ based on naphthalenediimide fluorophore are reported. Our strategy was to choose core‐substituted naphthalenediimide (NDI) as a novel NIR fluorophore and N,N‐di(pyridin‐2‐ylmethyl)ethane‐1,2‐diamine (DPEA) or N,N,N′‐tri(pyridin‐2‐ylmethyl)ethane‐1,2‐diamine (TPEA) as the receptor, respectively, so as to improve the selectivity to Zn2+. In the case of PND, the negligible shift in absorption and emission spectra is strongly suggestive that the secondary nitrogen atom (directly connected to the NDI moiety, N1) is little disturbed with Zn2+. The fluorescence enhancement of PND with Zn2+ titration is dominated with a typical photoinduced electron‐transfer (PET) process. In contrast, the N1 atom for PNT can participate in the coordination of Zn2+ ion, diminishing the electron delocalization of the NDI moiety and resulting in intramolecular charge‐transfer (ICT) disturbance. For PNT, the distinct blueshift in both absorbance and fluorescence is indicative of a combination of PET and ICT processes, which unexpectedly decreases the sensitivity to Zn2+. Due to the differential binding mode caused by the ligand effect, PND shows excellent selectivity to Zn2+ over other metal ions, with a larger fluorescent enhancement centered at 650 nm. Also both PND and PNT were successfully used to image intracellular Zn2+ ions in the living KB cells. 相似文献
957.
958.
A series of four related phenol derivatives, with 2,2′-dipicolylamine substituents at the ortho positions, were prepared and their Zn2+ coordination complexes studied by spectroscopic methods. X-ray crystal diffraction analysis of a dinuclear zinc complex with two bridging acetate anions showed a ternary structure with highly charged interior and lipophilic exterior, which helps explain why this class of water-soluble complexes can effectively diffuse through cell membranes. The stability of the dinuclear zinc complexes in aqueous solution was found to be strongly anion dependent; that is, bridging oxyanions, such as acetate and pyrophosphate, lock the two Zn2+ cations to the surrounding ligand and greatly enhance ligand/zinc affinity. Overall, the results provide new insight into the structural and mechanistic factors that control the recognition and chemosensing performance of phenoxide bridged dipicolylamine molecular probes. 相似文献
959.
960.
Photocatalytic oxidation of 4-chlorophenol using thermosensitive zinc phthalocyanine copolymer under visible light irradiation
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CHEN WenXing Lü WangYang SHEN XiaoYuan & YAO YuYuan Key Laboratory of Advanced Textile Materials Manufacturing Technology Ministry of Education Zhejiang University of Science & Technology Hangzhou China 《中国科学:化学》2010,(3)
A novel thermosensitive photocatalyst,P(NIPA-co-ZnMPc),has been prepared using zinc tetra(N-carbonylacrylic)aminophthalocya-nine(ZnMPc) to copolymerize with N-isopropylacrylamide(NIPA).The lower critical solution temperature(LCST) of P(NIPA-co-ZnMPc) measured by differential scanning calorimetry(DSC) was 33.5 °C.P(NIPA-co-ZnMPc) effectively catalyzes the oxidation of 4-chlorophenols(4-CP) using oxygen as oxidant under the visible light irradiation,and it has higher photocatalytic activity than ZnMPc under t... 相似文献