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991.
The mechanism of the pressure-induced tenderization of meat has not been fully established in spite of its beneficial effect. To detect the changes in the large structural proteins of the myofibrils induced by pressurization without heat treatment, high hydrostatic pressure (100-300 MPa) was applied to rabbit at-death skeletal muscle for 10 min at low temperature (0-2°C). Significant differences in the electrophoretic pattern of connectin (also called titin) in isolated myofibrils were observed between the control and pressurized muscle samples. The conversion of α-connectin (2800 kDa) to β-connectin (2100 kDa) was accelerated with increasing pressure applied to the muscle; also nebulin (800 kDa) was degraded by pressure treatment. From the results it is clear that the degradation of connectin is induced by pressurization alone without heat treatment. If the conversion of α-connectin to β-connectin during conditioning has some influence on meat tenderization, the pressure-induced conversion of α- to β-connectin is possibly one of the causes of pressure-induced tenderization of meat. 相似文献
992.
The infiltration behaviour of a tin melt, as an internal electrode, to the porous layers, and the electrical properties of multilayer ceramic capacitors was investigated by electrode infiltration. By preventing green-state delamination between the dielectric green sheet and the carbon paste, uniform porous layers, 5 m thick, could be formed after sintering. When 15 vol % ceramic pillars were added to the carbon paste, the porous layer of the sintered samples could be considered as a porous solid formed by many pores larger than 4 m. The critical pressure for the infiltration of tin melt into such a porous layer was found to be 0.5 MPa. With a high infiltration pressure, the resistivity of multilayer capacitors was decreased to 108–109cm due to the growth of micro-defects formed on the surface of the dielectric layers during the lamination process. 相似文献
993.
Dielectric properties and microstructural behaviour of B-site calcium-doped barium titanate ceramics 总被引:1,自引:0,他引:1
Dielectric properties and microstructural behaviour of Ba1–x
Sr
x
Ti1–y
Ca
y
O3–y
ceramics, where strontium and calcium were doped on the barium and titanium sites, respectively, within the range 0x0.24 and 0y0.05, were investigated. Calcium addition decreased the tetragonality,c/a, increased the unit cell volume, and lowered the Curie temperature, which were all attributed to the occupancy of Ca2+ ions on titanium sites. When sintered at a low oxygen partial pressure of 10–9 MPa, a resistivity higher than 1011 cm was maintained for the formulations containing B-site calcium substitution more than 0.5 mol %. With increasing the amount of calcium addition, the Curie peak was depressed and completely broadened for the compositions with calcium addition more than 3 mol %, where the average grain size was smaller than 1 m. Co-firing with nickel electrodes in a reducing atmosphere also depressed the Curie peak and inhibited the grain growth due to the diffusion of nickel into the dielectrics. 相似文献
994.
The authors studied actual nutrition and certain parameters of food (supply of vitamins A, E, C and the content of phospholipids, cholesterol, NEFA, triglycerides and cholesterol esters) for oil derrick installers working during summer at the "Mangyschlakneft" amalgamation. Incorrect structure of their nutrition and insufficient supply with vitamins A and C, revealed as the result of the study, necessitate rationalization of the nutrition for such workers. 相似文献
995.
Single-crystal (Cz) silicon wafers [(100) p-type] were cut in air, d6onked (DI) water and ethanol, at room temperature, 150 and 200°C by a diamond impregnated dicing wheel using a specially designed apparatus. The effects of environmental fluids and temperature on the cut surface morphology were examined by scanning electron microscopy (SEM). The SEM investigation showed that gouging and ploughing is predominant when silicon is cut in DI water or ethanol. Debris size analysis showed that the mean diameter of the volume distribution (MV) of debris formed in ethanol at room temperature was 9.5 m while that formed in air was 1.3 m. The surface morphology is significantly different at 150 and 200° C as compared to room temperature, i.e. the width of individual wear tracks varied from 0,8 m for room temperature to 1.6 m for 200° C. 相似文献
996.
Krishnaswamy R Kim CE 《IEEE transactions on pattern analysis and machine intelligence》1987,(2):316-321
The slope of digital line segments is defined and an algorithm to evaluate it is presented. Parallelism and perpendicularity of two digital line segments are also defined. Finally, rectangular digital regions are defined and characterized, and an algorithm that determines whether or not a given digital region is a digital rectangle is presented. 相似文献
997.
Ni59Zr20Ti16Si2Sn3 amorphous material was deposited by a vacuum plasma spraying technique onto steel and copper substrates in order to investigate their behaviour in a corrosive environment. For comparison, the same alloy was prepared as amorphous ribbons by melt spinning. The amorphous nature of the coatings and ribbons was characterized by XRD, DSC and TEM, while XPS and AES analyses were performed to understand the origin of passivation and mode of corrosion. The corrosion behaviour of the coating was studied in H2SO4 and HCl solutions open to air at room temperature. Potentiodynamic polarisation and galvanic coupling tests were carried out on the substrate and the coating. It was found that the formation of Zr-, Ti- and Si-rich passive oxide layers provide a high corrosion resistance in H2SO4 solution while the breakdown of the passive layer by chloride ion adsorption was responsible for pitting corrosion of the Ni59Zr20Ti16Si2Sn3 amorphous ribbons in HCl solution. Galvanic corrosion was the dominant corrosion mechanism for the coating/copper hybrid structure, in contrast to the Ni59Zr20Ti16Si2Sn3 amorphous coating, which efficiently protected the steel substrate in the corrosive environment. 相似文献
998.
电机电流分析法在机床类设备诊断中的应用研究 总被引:2,自引:0,他引:2
机床类设备传动链复杂,结构紧凑且封闭,对传动系统状态监测一直没有有效的分析办法,即使在噪声增大等恶劣情况下,常规的振动诊断方法也难以奏效.本文尝试用电流信号分析法,简称MCSA(Motor Current Signal Analysis),对机床状态进行测试和分析.通过电机电流信号的传动链齿轮谱特征分析,对其做出了正确评估,表明定子电流能很好地反映机床传动系统部件的运行状况.同时进行了多种运行工况的测试与试验,研究结论对机床类设备的生产制造和现场运行状态的分析提供了有效依据. 相似文献
999.
1000.