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991.
Huanping Yang Jian Jiang Weiwei Zhou Linfei Lai Lifei Xi Yeng Ming Lam Zexiang Shen Bahareh Khezri Ting Yu 《Nanoscale research letters》2011,6(1):531
MnO2 supported on graphene oxide (GO) made from different graphite materials has been synthesized and further investigated as electrode materials for supercapacitors. The structure and morphology of MnO2-GO nanocomposites are characterized by X-ray diffraction, X-ray photoemission spectroscopy, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and Nitrogen adsorption-desorption. As demonstrated, the GO fabricated from commercial expanded graphite (denoted as GO(1)) possesses more functional groups and larger interplane gap compared to the GO from commercial graphite powder (denoted as GO(2)). The surface area and functionalities of GO have significant effects on the morphology and electrochemical activity of MnO2, which lead to the fact that the loading amount of MnO2 on GO(1) is much higher than that on GO(2). Elemental analysis performed via inductively coupled plasma optical emission spectroscopy confirmed higher amounts of MnO2 loading on GO(1). As the electrode of supercapacitor, MnO2-GO(1) nanocomposites show larger capacitance (307.7 F g-1) and better electrochemical activity than MnO2-GO(2) possibly due to the high loading, good uniformity, and homogeneous distribution of MnO2 on GO(1) support. 相似文献
992.
In this article some metal hydroxystannates were synthesized. It shows that the ZHS with Fe2SnO3.3H2O imparts fairly good flame retardance to the plasticized poly (vinyl chloride) (PVC). The thermal stability and flammability on heating and burning were explored by TG/DTA. Study on mechanical properties of PVC had also been performed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
993.
The flame‐retardant and smoke‐suppressant properties of soft poly(vinyl chloride) (PVC) treated with zinc hydroxystannate (ZHS), calcium carbonate (CaCO3), magnesium hydroxystannate [MgSn(OH)6], strontium hydroxystannate [SrSn(OH)6], ZHS–MgSn(OH)6, ZHS–SrSn(OH)6, MgSn(OH)6‐coated CaCO3, SrSn(OH)6‐coated CaCO3, ZHS–MgSn(OH)6‐coated CaCO3, and ZHS–SrSn(OH)6‐coated CaCO3 were studied with the limited oxygen index, char yield, and smoke density rating methods; the mechanical properties were also studied. The results showed that, with the equivalent addition of the corresponding hydroxystannate, the soft PVC treated with hydroxystannate‐coated CaCO3 had a higher limited oxygen index than the corresponding hydroxystannate, and the soft PVC treated with the agents containing magnesium had a higher limited oxygen index than the soft PVC treated with the agents containing strontium, except for ZHS–MgSn(OH)6‐coated CaCO3. The improvement in the char formation of the hydroxystannate‐coated CaCO3 was better than that of the corresponding hydroxystannate in most cases, and the aforementioned agents reduced the smoke density rating, decreased the tensile strength, and increased the elongation and impact strength basically. Thermal analysis showed that the additives promoted the evolution of hydrogen chloride, early crosslinking, and rapid charring through the strong catalyzing effect of Lewis acids. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
994.
Weiwei Deng C. Mike Waits Brian Morgan Alessandro Gomez 《Journal of aerosol science》2009,40(10):907-918
Widespread application of the cone-jet electrospray has been hampered by the low flow rate at which the spray is dispersed, despite the unique ability of this device to disperse quasi-monodispersed particles over a phenomenal size range. Compact multiplexing, that is, with a high number of sources per unit area, is indispensable for dramatically increasing the throughput and reducing the cost per electrospray source. We demonstrate the successful operation of multiplexed electrospray systems with an unprecedented packing density of up to 11,547 sources/cm2. The devices were fabricated and operated by implementing three criteria: (a) the extractor electrode configuration should be used to localize the electric field; (b) the viscous pressure drop acting on the liquid should dominate with respect to the electrostatic pulling force by the electric field; and (c) the electric field “driving” the droplets between the extractor electrode and the collector should be sufficiently intense to avoid reversal of the droplet motion near the extractor (satellite trapping). All devices showed excellent droplet size uniformity across the entire spray region, which indicates effective decoupling of the electrospray sources even for closely packed nozzles. The experimental results show that these design criteria provide effective and reliable guidelines for the successful design and operation of multiplexed devices from first principles, that is, based only on knowledge of the suitability of a liquid for electrospray dispersion and of the critical liquid properties such as surface tension, viscosity and electric conductivity. As a result, the design of these devices for a given application is achievable without costly trial-and-error microfabrication trials. This development opens the door for applications requiring flows from multiplexing 106–107 individual electrospray sources from industry-standard 12-in silicon wafers. 相似文献
995.
L. Jiao X. Niu Z. Lu C. R. Wronski A. Matsuda T. Kamei G. Ganguly 《Solar Energy Materials & Solar Cells》2001,66(1-4)
A study has been carried out on a-Si:H solar cell materials fabricated under a wide range of deposition conditions in different laboratories. The results on both thin films and corresponding Schottky barrier cell structures demonstrate that analysis and characterization based solely on the neutral dangling bonds are clearly inadequate. Contributions of charged defects to the properties of a-Si:H, their effect on light-induced changes are identified together with the limitations of methods commonly used to characterize the solar cell properties and stability of a-Si:H materials. Self-consistent fitting of a wide range of results on films and Schottky barrier cell structures is obtained with a gap state distribution in which charged defects are included. 相似文献
996.
介绍钢纤维砼在局部压力作用下的强度和延性的变化规律,再与砼中配有钢筋网片的情况对比,得出了提高砼局部抗压能力的有效方法。 相似文献
997.
McClain D. Thomas N. Youkey S. Schaller R. Jiao J. O'Brien K. P. 《Electron Device Letters, IEEE》2010,31(2):156-158
998.
以具有快速强放热特性的甲苯液相SO3磺化为目标反应,利用微反应器热、质传递能力强的优点,以提高反应性能和过程可控性。针对微反应器内的甲苯液相SO3磺化工艺进行了研究,考察了反应温度、SO3质量分数、SO3与甲苯物质的量之比、空速(LHSV)、产物放置时间、溶剂极性和母液循环次数对产物选择性的影响。结果表明,在温度为28℃、LHSV为13 000 h-1、1,2-二氯乙烷为溶剂的条件下,通过母液多次循环,磺酸异构体产物中对甲苯磺酸的选择性高达96.54%,间甲苯磺酸选择性则降低至0.33%。 相似文献
999.
Weiwei Liu Younho Cho Haidang Phan Jan D. Achenbach 《Journal of Mechanical Science and Technology》2011,25(3):797-802
A frequency domain boundary element method is introduced in this paper to simulate the scattering of two-dimensional Rayleigh
waves by a cavity on the surface of an elastic half-space. This numerical method allows the Rayleigh wave to escape the truncated
boundary without producing any spurious reflections. The numerical results of the displacements and stresses of a 2-D Rayleigh
wave which travels along a flat surface of an elastic half-infinite medium are in good agreement when compared with theoretical
ones. The problem of a Rayleigh wave scattering by a cavity on the surface of an elastic half-infinite medium is simulated
by the proposed numerical method. The result is taken as the benchmark to introduce an approximate analytical method for such
problems of scattering by a cavity on the surface. This numerical method is formulated for a two-dimensional homogeneous,
isotropic, linearly elastic half-space and its implementation in a frequency domain boundary scheme is discussed in detail. 相似文献
1000.