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961.
WU Bo LI WenBin YU HaoMiao YOU YinTao CHEN XiaoQing HE Yun HOU XiaoYuan 《中国科学:物理学 力学 天文学(英文版)》2013,56(10):2012-2015
Transient photovoltage of ITO/organic/Al cells is studied under different bias polarities and voltages.It is found that for an ITO/NPB/Al cell,light incidence on the Al side induces more bias-dependent transient photovoltage variation when the photovoltage is positive than when it is negative.However,for an ITO/C60 /Al cell,the variation characteristics of transient photovoltage is reversed.These results support the previously proposed mechanism that Al could inject charges into the organic layer upon photon excitation,indicating that the absorption of electrode can also contribute to photovoltaic effect. 相似文献
962.
Let $\varPhi_{t,\pi}: M_{3}({\mathbb{C}}) \rightarrow M_{3}({\mathbb{C}})$ be a linear map defined by $\varPhi_{t,\pi}(A)=(3-t)\*\sum_{i=1}^{3}E_{ii}AE_{ii}+t\sum_{i=1}^{3}E_{i,\pi (i)}AE_{i,\pi(i)}^{\dag}-A$ , where 0≤t≤3 and π is a permutation of (1,2,3). We show that the Hermitian matrix $W_{\varPhi_{t,\pi}}$ induced by Φ t,π is an optimal entanglement witness if and only if t=1 and π is cyclic. 相似文献
963.
In this paper, we study the 3D axisymmetric Navier–Stokes equations with swirl. We prove the global regularity of the 3D Navier–Stokes equations for a family of large anisotropic initial data. Moreover, we obtain a global bound of the solution in terms of its initial data in some L p norm. Our results also reveal some interesting dynamic growth behavior of the solution due to the interaction between the angular velocity and the angular vorticity fields. 相似文献
964.
This paper covers the dynamic behaviors for a class of Nicholson’s blowflies models with a nonlinear density-dependent mortality term. By using inequality analyze technique and coincidence degree theory, some sufficient conditions are determined that guarantee the permanence of the model and the existence of positive periodic solutions. Moreover, we give an example to illustrate our main results. 相似文献
965.
966.
Let G be a connected graph and D(G) be its distance matrix. In this article, the Smith normal forms of the integer matrices D(G) are determined for trees, wheels, cycles, complements of cycles and are reduced for complete multipartite graphs. 相似文献
967.
In this paper, the regular endomorphisms of the join of split graphs are investigated. We give a condition under which the regular endomorphisms of the join of split graphs form a monoid. 相似文献
968.
Lack of information during the growth of carbon nanotubes has hindered efforts to understand the growth mechanism of these unique nanoscale structures. Here, we report that Multi‐walled carbon nanotubes with bamboo‐shaped structure may be synthesized by solvothermal method at 300°C using benzene as carbon source and Zn as catalyst. We have obtained direct experimental information on the growth under Transmission electron microscopy. It has been shown that all the compartments of bamboo‐like tube successively joined leading to the formation of regularly segmented nanobamboos. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
969.
Samraj Mollick Soumya Mukherjee Dongwook Kim Zhiwei Qiao Aamod V. Desai Rajat Saha Yogeshwar D. More Jianwen Jiang Myoung Soo Lah Sujit K. Ghosh 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(4):1053-1057
Metal–organic polyhedra (MOP) are a promising class of crystalline porous materials with multifarious potential applications. Although MOPs and metal–organic frameworks (MOFs) have similar potential in terms of their intrinsic porosities and physicochemical properties, the exploitation of carboxylate MOPs is still rudimentary because of the lack of systematic development addressing their chemical stability. Herein we describe the fabrication of chemically robust carboxylate MOPs via outer‐surface functionalization as an a priori methodology, to stabilize those MOPs system where metal–ligand bond is not so strong. Fine‐tuning of hydrophobic shielding is key to attaining chemical inertness with retention of the framework integrity over a wide range of pH values, in strong acidic conditions, and in oxidizing and reducing media. These results are further corroborated by molecular modelling studies. Owing to the unprecedented transition from instability to a chemically ultra‐stable regime using a rapid ambient‐temperature gram‐scale synthesis (within seconds), a prototype strategy towards chemically stable MOPs is reported. 相似文献
970.
Sheng‐Li Hou Jie Dong Xiao‐Lei Jiang Zhuo‐Hao Jiao Bin Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(2):587-591
Cyclization of propargylic alcohols with CO2 is an important reaction in industry, and noble‐metal catalysts are often employed to ensure the high product yields under environmentally friendly conditions. Herein a porous noble‐metal‐free framework 1 with large 1D channels of 1.66 nm diameter was synthesized for this reaction. Compound 1 exhibits excellent acid/base stability, and is even stable in corrosive triethylamine for one month. Catalytic studies indicate that 1 is an effective catalyst for the cyclization of propargylic alcohols and CO2 without any solvents under mild conditions, and the turnover number (TON) can reach to a record value of 14 400. Furthermore, this MOF catalyst also has rarely seen catalytic activity when the biological macromolecule ethisterone was used as a substrate. Mechanistic studies reveal that the synergistic catalytic effect between CuI and InIII plays a key role in the conversion of CO2. 相似文献