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961.
Xianghua Li Chunsheng Zhao Jun Lin Shenfang Yuan 《Optics and Lasers in Engineering》2007,45(7):819-826
The performance analysis of three-dimensional (3-D) braided composites is made difficult by their complex and interlacing structure, and is still under development. To get complete first-hand data on the material parameters of these composites, co-braided optical fiber sensors (OFS) can be used to measure the internal strain. This information is helpful for subsequent stiffness predictions and failure analysis. This paper introduces a method of incorporating OFS into braided composites, and establishes a constitutive theoretical model for the hybrid material. Experiments are conducted to measure the internal strain of specimens under tension, and the results are compared to theoretical predictions. 相似文献
962.
S.K. Biswas A.R. Ghatak A. Neogi A. Sharma S. Bhattacharya K.P. Ghatak 《Physica E: Low-dimensional Systems and Nanostructures》2007,36(2):163-177
We study theoretically the thermoelectric power in the presence of a large magnetic field (TPM) in heavily doped III–V, II–VI, PbTe/PbSnTe, strained layer and HgTe/CdTe quantum dot superlattices (QDSLs) with graded structures on the basis of newly formulated electron energy spectra and compare the same with that of the constituent materials. It has been found, taking heavily doped GaAs/Ga1−xAlxAs, CdS/CdTe, PbTe/PbSnTe, InAs/GaSb and HgTe/CdTe QDSLs as examples, that the TPM increases with increasing inverse electron concentration and film thickness, respectively, in different oscillatory manners and the nature of oscillations is totally band structure dependent. We have also suggested the experimental methods of determining the Einstein relation for the diffusivity–mobility ratio, the Debye screening length and the electronic contribution to the elastic constants for materials having arbitrary dispersion laws. 相似文献
963.
EAST����Դ���ϵͳ�������ʵ�� 总被引:2,自引:0,他引:2
利用组态软件编程设计监控界面,监控节点通过与现场总线控制器及高压监控节点的通信,实现对极向场电源状态的实时、可靠监控,并经ODBC接口将状态数据发送至数据库节点备份。简述了电源监控系统的构成,及通过不同的通信协议实现实时数据传输和处理的过程。 相似文献
964.
Zbigniew Kisiel Lech Pszczó?kowski Steven B. Charnley 《Journal of Molecular Spectroscopy》2007,241(2):220-229
The rotational spectrum of pyruvic acid has been investigated for the first time in the millimeter-wave region, at 160-314 GHz, and also in supersonic expansion, at 10-17.4 GHz. The analysis of the broadband spectra recorded in this work was carried out with the newly developed AABS software package for Assignment and Analysis of Broadband Spectra, and precise spectroscopic constants are reported for the ground state, the first excited state of the low-frequency skeletal torsional mode ν24, and the first excited state of the methyl torsional mode ν23. Limited results have also been obtained for several higher excited states. The dataset for the ground state currently exceeds 1500 lines and for both the A and E internal rotor sublevels spans the complete range of values of Ka at the mid values of J for the measured transitions. The results were analysed with three freely available computer programs employing different strategies for dealing with internal rotation and a comparative discussion of their merits is made. 相似文献
965.
Shiming Zhang Yugeng Wen Weiyi Zhou Yunlong Guo Lanchao Ma Xingang Zhao Zhen Zhao Stephen Barlow Seth R. Marder Yunqi Liu Xiaowei Zhan 《Journal of polymer science. Part A, Polymer chemistry》2013,51(7):1550-1558
Solution‐processable polymers consisting of perylene diimide (PDI) acceptor moieties alternating with dithienothiophene (DTT), N‐dodecyl‐dithienopyrrole (DTP), or oligomers of these donor groups have been synthesized. We have, in addition to varying the donor, varied the N,N′ substituents of the PDIs. The thermal, optical, electrochemical, and charge‐transport properties of the polymers have been investigated. The polymers show broad absorption extending from 300 to 1000 nm with optical band gaps as low as 1.2 eV; the band gap decreases with increasing the conjugation length of donor block, or by replacement of DTT by DTP. The electron affinities of the polymers, estimated from electrochemical data, range from ?3.87 to ?4.01 eV and are slightly affected by the specific choice of donor moiety, while the estimated ionization potentials (?5.31 to ?5.92 eV) are more sensitive to the choice of donor. Bottom‐gate top‐contact organic field‐effect transistors based on the polymers generally exhibit n‐channel behavior with electron mobilities as high as 1.7 × 10–2 cm2/V/s and on/off ratios as high as 106; one PDI‐DTP polymer is an ambipolar transport material with electron mobility of 4 × 10–4 cm2/V/s and hole mobility of 4 × 10–5 cm2/V/s in air. There is considerable variation in the charge transport properties of the polymers with the chemical structures. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
966.
Prakash Sista Mahesh P. Bhatt Ashton R. Mccary Hien Nguyen Jing Hao Michael C. Biewer Mihaela C. Stefan 《Journal of polymer science. Part A, Polymer chemistry》2011,49(10):2292-2302
Poly{4,8‐bis(4‐decylphenylethynyl)benzo[1,2‐b:4,5‐b′]dithiophene} ( P1 ) homopolymer and poly{4,8‐bis(4‐decylphenylethynyl)benzo[1,2‐b:4,5‐b′]dithiophene ‐alt‐thiophene} ( P2 ) alternating copolymer have been synthesized by Stille coupling polymerization. The field‐effect mobilities of both polymers were measured on both untreated and silane‐treated OFET devices. Various silanes were selected to allow an incremental increase in the hydrophobicity of the silicon dioxide dielectric. A direct correlation was observed between the hydrophobicity of the silicon dioxide dielectric surface and the enhancement of the field‐effect mobilities. The highest mobilities for both polymers were measured on the OFET devices treated with heptadecafluoro‐1,1,2,2‐tetrahydro‐decyl‐1‐trimethoxysilane (FS) which generated the most hydrophobic surface. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
967.
Kang‐Jun Baeg Dongyoon Khim Dong‐Yu Kim Soon‐Won Jung Jae Bon Koo In‐Kyu You Henry Yan Antonio Facchetti Yong‐Young Noh 《Journal of Polymer Science.Polymer Physics》2011,49(1):62-67
Inkjet‐printed high speed polymeric complementary circuits are fabricated using an n‐type ([poly{[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐dithiophene)} [P(NDI2OD‐T2), Polyera ActivInk N2200] and two p‐type polymers [poly(3‐hexylthiophene) (P3HT) and a dithiophene‐based polymer (Polyera ActivInk P2100)]. The top‐gate/bottom‐contact (TG/BC) organic field‐effect transistors (OFETs) exhibit well‐balanced and very‐high hole and electron mobilities (μFET) of 0.2–0.5 cm2/Vs, which were enabled by optimization of the inkjet‐printed active features, small contact resistance both of electron and hole injections, and effective control over gate dielectrics and its orthogonal solvent effect (selection of poly(methyl methacrylate) and 2‐ethoxyethanol). Our first demonstrated inkjet‐printed polymeric complementary devices have been integrated to high‐performance complementary inverters (gain >30) and ring oscillators (oscillation frequency ~50 kHz). We believe that the operating frequency of printable organic circuits can be further improved more than 10 MHz by fine‐tuning of the device architecture and optimization of the p‐ and n‐channel semiconductor processing. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010 相似文献
968.
Benjamin Waldher Jadwiga Kuta Samuel Chen Neil Henson Aurora E. Clark 《Journal of computational chemistry》2010,31(12):2307-2316
The ForceFit program package has been developed for fitting classical force field parameters based upon a force matching algorithm to quantum mechanical gradients of configurations that span the potential energy surface of the system. The program, which runs under UNIX and is written in C++, is an easy‐to‐use, nonproprietary platform that enables gradient fitting of a wide variety of functional force field forms to quantum mechanical information obtained from an array of common electronic structure codes. All aspects of the fitting process are run from a graphical user interface, from the parsing of quantum mechanical data, assembling of a potential energy surface database, setting the force field, and variables to be optimized, choosing a molecular mechanics code for comparison to the reference data, and finally, the initiation of a least squares minimization algorithm. Furthermore, the code is based on a modular templated code design that enables the facile addition of new functionality to the program. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010 相似文献
969.
研究了二次域Q(√7)中单位Vn+Un√7)=(8+3√7)n所给出的两个递归数列{Vn},{Un}中的三角数问题,找到了{Vn},{Un}中的所有的三角数.作为应用,给出了与其相关的两个不定方程的整数解. 相似文献
970.