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排序方式: 共有9629条查询结果,搜索用时 140 毫秒
131.
132.
LIANGChenghao MOUZhanqi 《稀有金属(英文版)》2002,21(4):266-270
The electrochemical behaviors of commercially pure titanium(CP Ti) and Co-Cr alloy in Ringer‘s solution have been investigated.The results indicate that the electric potential of passive region for CP Ti is up to 3000mV,and its passive current density is 3.078 μA/cm^2,The excellent corrosion resistance of CP Ti can be attributed to the formation of TiO2 oxide film.The passive region of Co-Cr alloy is 770mV,which is narrower than that of CP Ti.However,no hystersis loops are found in the reverse scanning curves of Cu-Cr alloy.A complex oxide film of Co3O4,Co2O3,and Cr2O3 formed on the surface provides Co-Cr alloy with a stable electrochemistry property.The corrosion rates of the crevice samples increase with the pH value of medium decreasing.The electron probe microanalyzer(EPMA) analysis indicates that Ti in CP Ti and Co,Cr in Co-Cr alloy dissolve in crevice area due to the Sealed-Cell effect. 相似文献
133.
1 INTRODUCTIONMagnesium and magnesium based alloys arepromising hydrogen storage materials because oftheir absorbability of hydrogen in large quantities,low specific gravity, rich mineral resources, lowmaterial cost and so on. Nevertheless, their hy drides are too stable to be used at room tempera ture[1]. It seems impossible for application of crys talline Mg based alloys in nickel hydrogen batter ies.It is well known that amorphous alloys havemany advanta… 相似文献
134.
钴酸锂的再生及其电化学性能 总被引:3,自引:0,他引:3
采用提取的含少量Co3O4的LiCoO2为原料,在不同温度下合成正极材料LiCoO2,烧结时间为12 h,并采用XRD和SEM技术研究合成的LiCoO2的晶相结构与微观形貌。结果发现:烧结温度对LiCoO2的晶体结构影响较大,烧结温度越高,LiCoO2的层状结构发育越完整。循环伏安曲线很好地反映了再生LiCoO2的脱/嵌锂行为。将LiCoO2样品做成电池进行电化学检测,结果发现,烧结温度为850℃的样品首次放电容量为151mA.h/g,30次循环之后,放电容量仍有141mA.h/g,表现出良好的电化学性能。 相似文献
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136.
G. Antou G. Montavon F. Hlawka A. Cornet C. Coddet 《Journal of Thermal Spray Technology》2006,15(4):765-772
Complex multiscale pore network architecture characterized by multimodal pore size distribution and connectivity develops
during the manufacture of ceramic thermal spray coatings from intra- and interlamellar cracks generated when each lamella
spreads and solidifies to globular pores resulting from lamella stacking defects. This network significantly affects the coating
properties and their in-service behaviors. De Hoff stereological analysis permits quantification of the three-dimensional
(3D) distribution of spheroids (i.e., pores) from the determination of their two-dimensional (2D) distribution estimated by
image analysis when analyzing the coating structure from a polished plane. Electrochemical impedance spectroscopy electrochemically
examines a material surface by frequency variable current and potential and analyzes the complex impedance. When a coating
covers the material surface, the electrolyte percolates through the more or less connected pore network to locally passivate
the substrate. The resistive and capacitive characteristics of the equivalent electrical circuit will depend upon the connected
pore network architecture. Both protocols were implemented to quantify thermal spray coating structures. Al2O3-13TiO2 coatings were atmospherically plasma sprayed using several sets of power parameters, are current intensity, plasma gas total
flow rate, and plasma gas composition in order to determine their effects on pore network architecture. Particle characteristics
upon impact, especially their related dimensionless numbers, such as Reynolds, Weber, and Sommerfeld criteria, were also determined.
Analyses permitted identification of (a) the major effects of power parameters upon pore architecture and (b) the related
formation mechanisms.
This article was originally published inBuilding on 100 Years of Success, Proceedings of the 2006 International Thermal Spray Conference (Seattle, WA), May 15–18, 2006, B.R. Marple, M.M. Hyland, Y.-Ch. Lau, R.S. Lima, and J. Voyer, Ed., ASM International, Materials
Park, OH, 2006. 相似文献
137.
1 INTRODUCTIONIn recent years, the application of the roomtemperature type ( < 100 ℃) polymer electrolytemembrane fuel cells(PEMFCs) as a primary powersource in electric vehicles and portable equipmentsetc has received increasing attention[1 4]. Usuallyin a PEMFC system, platinum is chosen as the e lectrode electrocatalyst, however, it results in ahigh cost PEMFC system for commercialization be cause Pt is a high cost, source limit metal. So,looking fo… 相似文献
138.
139.
铝阳极氧化膜在NaCl溶液中的电化学性能 总被引:11,自引:4,他引:11
采用交流阻抗法研究了工业纯铝L3阳极氧化膜在中性NaCl溶液中交流阻抗谱的变化规律, 比较了未封闭处理与沸水封闭处理后氧化膜的交流阻抗谱的差异, 并结合等效电路分析了氧化膜多孔层与阻挡层电化学参数的变化.结果表明, 未封闭的阳极氧化膜在NaCl溶液中浸泡初期存在一个自封闭过程, 封闭处理明显提高氧化膜多孔层的初始Rp值并降低初始CPEp值; 溶液中侵蚀性离子浓度越高, 封闭处理提高铝阳极氧化膜的耐蚀性能作用越明显. 相似文献
140.