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41.
Preparation of micro-arc oxidation coatings on magnesium alloy and its thermal shock resistance property 总被引:2,自引:1,他引:2
JIANG Zhaohua ZENG Xiaobin and YAO Zhongping Department of Applied Chemistry Harbin Institute of Technology Harbin China 《稀有金属(英文版)》2006,25(3):270-273
1. Introduction Due to their high specific strength, good electro-magnetic shielding characteristics, high damping characteristics, good cast ability, and excellent pol-ishing capability, magnesium alloys are extensively used in aeronautical, automobile, and electro- communication industries [1-3]. But magnesium has some disadvantages, such as low chemical stability, high negative electric potential, and low hardness, so it is necessary to use surface disposal to accommo-date the demand for re… 相似文献
42.
天然气井下节流嘴前后压力温度分布的数值计算 总被引:6,自引:0,他引:6
针对天然气井安装井下节流装置以后很难测得节流嘴上游压力的情况,从空气动力学的原理出发,提出根据井口采集的数据,从节流嘴下游向上游计算其喉部和上游的压力温度综合值的数值计算方法。采用临界状态判别的新方法,即依据节流嘴出口处的马赫数的值,对节流嘴附近的流态进行判别,再分别计算节流嘴出口处,节流嘴喉部以及节流嘴上游的各参数。对宝1井进行了实例计算,计算结果表明:节流后压力温度骤降,经过激波面后压力温度急剧升高的变化情况。 相似文献
43.
Dr. Daisuke Okuno Dr. Noriho Sakamoto Dr. Mohammed S. O. Tagod Yoshiko Akiyama Dr. Sakiko Moriyama Dr. Takuto Miyamura Dr. Atsuko Hara Dr. Takashi Kido Dr. Hiroshi Ishimoto Prof. Yuji Ishimatsu Prof. Takashi Tanaka Prof. Jun Ishihara Prof. Kohsuke Takeda Prof. Yoshimasa Tanaka Prof. Hiroshi Mukae 《ChemMedChem》2021,16(16):2515-2523
Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, is causally related to fibrotic diseases, including idiopathic pulmonary fibrosis. The identification of Compounds that interfere with the HSP47-collagen interaction is essential for the development of relevant therapeutics. Herein, we prepared human HSP47 as a soluble fusion protein expressed in E. coli and established an assay system for HSP47 inhibitor screening. We screened a natural and synthetic Compound library established at Nagasaki University. Among 1023 Compounds, 13 exhibited inhibitory activity against human HSP47, of which three inhibited its function in a dose-dependent manner. Epigallocatechin-3-O-gallate, one of these three Compounds, is a typical polyphenol Compound derived from tea leaves. Structurally related Compounds were synthesized and examined for their activity, revealing a hydroxyl group at A-ring position 5 as important for its activity. The present findings provide valuable insight for the development of natural product-derived therapeutics for fibrotic diseases, including idiopathic pulmonary fibrosis. 相似文献
44.
Pengtao Zhai Mingyang Liu Wenying Zhou Liugang Chen Dafei Ding Guotian Ye 《International Journal of Applied Ceramic Technology》2021,18(3):1017-1024
Refractory materials such as mullite, andalusite, forsterite, and cordierite are generally used to prepare saggers for the calcination of Li-ion battery Li(NixCoyMnz)O2 (LNCM) cathode material. However, these compounds are prone to be attacked by the LNCM materials, thereby leading to short life spans and contamination of the Li-ion battery cathode materials. To improve the corrosion resistance of refractory sagger materials, the most clear cut-way is enhancing the corrosion resistance of matrix using a new refractory component. Potassium aluminate (K2O·11Al2O3, KA11) with an excellent corrosion resistance against alkaline oxide was synthesized via solid-state method using potassium carbonate (K2CO3) and industrial alumina powder (Al2O3). Interactions between KA11 and LNCM cathode materials at 800°C–1100°C were characterized by refractory-LNCM precursor laboratory-scale tests to understand the corrosion behavior of KA11. The microstructure and phase composition of synthesized KA11 and the calcined KA11-LNCM mixture cylinders were analyzed with SEM and XRD. The observations reveal that KA11 shows a better corrosion resistance to LNCM materials compared with mullite, cordierite, and forsterite. The addition of synthesized KA11 also favors the thermal shock resistances of mullite-based sagger materials. 相似文献
45.
以烧结刚玉、碳化硅等为主要原料,分别以红柱石0%、5%、10%、15%替换相同比例的烧结刚玉,同时外加少量的改性剂A制备四组浇注料,对比四种浇注料经1 400 ℃处理后的常温性能、线变化、抗热震性、抗碱侵蚀能力。结果表明,添加红柱石10%和改性剂1%的烧结刚玉基窑口浇注料表现出较好的使用性能。 相似文献
46.
G. Antou F. Hlawka A. Cornet G. Montavon C. Coddet F. Machi 《Journal of Thermal Spray Technology》2004,13(3):381-389
Several studies have been undertaken recently to adapt yttria partially stabilized zirconia (YPSZ) thermal barrier coating
(TBC) characteristics during their manufacturing process. Thermal spraying implementing laser irradiation appears to be a
possibility for modifying the coating morphology. This study aims to present the results of in situ (i.e., simultaneous treatment)
and a posteriori (i.e., post-treatment) laser treatments implementing a high-power laser diode. In both cases, the coatings
underwent atmospheric plasma spraying (APS). Laser irradiation was achieved using a 3 kW, average-power laser diode exhibiting
an 848 nm wavelength. Experiments were performed to reach two goals. First, laser post-treatments aimed at building a map
of the laser-processing parameter effects on the coating microstructure to estimate the laser-processing parameters, which
seem to be suited to the change into in situ coating remelting. Second, in situ coating remelting aimed at quantifying the
involved phenomena. In that case, the coating was treated layer by layer as it was manufactured. The input energy effect was
studied by varying the scanning velocity (i.e., between 35 and 60 m/min), and consequently the irradiation time (i.e., between
1.8 and 3.1 ms, respectively). Experiments showed that coating thermal conductivity was lowered by more than 20% and that
coating resistance to isothermal shocks was increased very significantly. 相似文献
47.
H. Y. Zhao H. Wang Q.J. Liu J.D. Kan Z.Q. LiuDepartment of Materials Science Engineering Yunnan University Kunming China 《金属学报(英文版)》2002,15(5):431-438
Shock wave and annealing crystallization of amorphous alloys FeSiB, FeMoSiB and FeCuNbSiB were studied by isothermal and non-isothermal DSC technique. It was found that the shock wave crystallization is very perfect, the fraction crystallized is very close to 100%, though the period of crystallization is very short, only about 10-4-10-6s. Their produced phases differ from the parent phase in structure and composition. The high velocity of the transformation is very difficult to explain by the diffusion theory of solid state phase transition. 相似文献
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