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Films of electroactive polymers, such as polyaniline (PAN) in its emeraldine base form, and poly(3-alkylthiophene), poly(3-hexylthiophene) (P6TH), poly(3-octylthiophene) (P8TH), and poly(3-dodecylthiophene) (P12TH) can be readily functionalized via thermal or near ultraviolet-light-induced surface graft copolymerization with monomers of polyelectrolyte, polyampholyte and polymeric acids. The monomers used in the present work include dimethyl sulphate quaternized dimethylamino-ethylmethacrylate (DMAEM·C2H6SO4), 3-dimethyl(methacryloyloxyethyl)ammonium propane sulphonate (DMAPS), acrylic acid (AAc) and a sodium salt of styrene sulphonic acid (NaSS). The surface structures and compositions of the electroactive polymer films after functionalization via graft copolymerization were characterized by angle-resolved X-ray photoelectron spectroscopy. Graft copolymerization of poly(3-alkylthiophene) films, but not PAN films, with the hydrophilic monomers readily results in a stratified surface microstructure arising from the migration of the hydrophilic graft chains beneath a thin surface layer which is much richer in the substrate chains. On the other hand, graft copolymerization of PAN films with AAc and NaSS readily gives rise to a self-protonated (and thus conductive) surface structure. 相似文献
23.
N‐(4‐Acetoxyphenyl) maleimide (APMI) and three kinds of comonomers bearing a trimethylsilyl group were copolymerized at 60°C in the presence of azobisisobutyronitrile (AIBN) as an initiator in 1,4‐dioxane to obtain the three IP, IIP, and IIIP copolymers. These copolymers were removed from the acetoxy group in a transesterification process into new IVP, VP, and VIP copolymers with a pendant hydroxyl group. Two modified processes were adopted to prepare photoresists using these copolymers. The first process involved mixing the dissolution inhibitor, o‐nitrobenzyl cholate, with the new copolymers. Second, o‐nitrobenzyl cholate was introduced into the copolymers using 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in dimethylformamide (DMF). The cyclic maleimide structure is responsible for the high thermal stability of these copolymers. After irradiation using deep–UV light and development with aqueous Na2CO3 (0.01 wt %), the developed patterns showed positive images and exhibited good adhesion to the silicon wafer without using any adhesion promoter. The resolution of these resists was at least 0.8 μm and an oxygen‐plasma etching rate was 1/5.3 to that of hard‐baked HPR‐204. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2791–2798, 2002; DOI 10.1002/app.10255 相似文献
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The stress buffer layer (SBL) is a widely applied improvement in many advanced packages used to release the stress concentration at solder joints. However, it has been generally found that the metal line adjacent to the SBL may suffer larger deformation and its reliability should be addressed. In this study, the panel level package (PLP) technology with solder on polymer (SOP) structure is selected as the testing sample to investigate the effect of SBL. The ball shear strength test is conducted first to investigate the reliability of metal trace in PLP. In addition, finite element (FE) analysis is applied to understand the actual thermo-mechanical behavior of PLP after its assembly. The package-level and board-level reliability assessments are compared, and the suggested layout of the redistribution layer on the SBL is provided herein. 相似文献
26.
Packaging represents a significant and expensive obstacle in commercializing microsystem technology (MST) devices such as microelectromechanical systems (MEMS), microopticalelectromechanical systems (MOEMS), microsensors, microactuators, and other micromachined devices. This paper describes a novel wafer-level protection method for MSTs which facilitate improved manufacturing throughput and automation in package assembly, wafer-level testing of devices, and enhanced device performance. The method involves the use of a wafer-sized microcap array. This array consists of an assortment of small caps molded onto a material with adjustable shapes and sizes to serve as protective structures against the hostile environments associated with packaging. It may also include modifications which enhance its adhesion to the MST wafer or increase the MST device function. Depending on the application, the micromolded cap can be designed and modified to facilitate additional functions, such as optical, electrical, mechanical, and chemical functions, which are not easily achieved in the device by traditional means. The fabrication and materials selection of the microcap device is discussed in this paper. The results of wafer-level microcap packaging demonstrations are also presented. 相似文献
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28.
S.Y. Cheng K.S. Chiang H.P. Chan 《Photonics Technology Letters, IEEE》2003,15(5):700-702
We report the fabrication of benzocyclobutene strip optical waveguides and the measurement of their birefringence properties. To take into account the stress-induced birefringence in the waveguide, we generalize the formulas reported previously for the analysis of strip waveguides. Our experimental results are shown to agree closely with the theoretical calculation. The condition for achieving zero modal birefringence by control of the aspect ratio of the strip of the waveguide is highlighted. The dependence of the birefringence in the waveguides on the temperature is also measured and discussed. 相似文献
29.
Han‐Lang Wu Chen‐Chi M. Ma Chun‐Chieh Lin Yie‐Chan Chiu Chih‐Yuan Chen Chin‐Lung Chiang 《应用聚合物科学杂志》2008,107(5):3236-3243
Poly(arylene ether benzonitrile) (PAEBN) was synthesized with 2,6‐dichlorobenzonitrile and biphenol. PAEBNs with various molecular weights (MWs), 1,640,000 and 185,000 g/mol, were synthesized by control of the stoichiometry of the monomers and were blended with sulfonated poly(ether ether ketone) (SPEEK). The effects of MW on the water uptake, swelling, methanol permeability, and proton conductivity of the SPEEK/PAEBN blend membranes were investigated. The molecular mobility of the SPEEK/PAEBN blends was also examined in this study. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
30.
ROI-based Watermarking Scheme for JPEG 2000 总被引:1,自引:0,他引:1
Yu-Cheng Fan Arvin Chiang Jan-Hung Shen 《Circuits, Systems, and Signal Processing》2008,27(5):763-774
A new region of interest (ROI)-based watermarking method for JPEG 2000 is presented. The watermark is embedded into the host
image based on the characteristics of the ROI to protect rights to the images. This scheme integrates the watermarking process
with JPEG 2000 compression procedures. Experimental results have demonstrated that the proposed watermark technique successfully
survives JPEG 2000 compression, progressive transmission, and principal attacks. 相似文献