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961.
Song Chen Author Vitae Takeshi Yoshimura Author Vitae 《Integration, the VLSI Journal》2010,43(4):378-388
3-D (stacked device layers) ICs can significantly alleviate the interconnect problem coming with the decreasing feature size and is promising for heterogeneous integration. In this paper, we concentrate on the configuration number and fixed-outline constraints in the floorplanning for 3-D ICs. Extended sequence pair, named partitioned sequence pair (in short, P-SP), is used to represent 3-D IC floorplans. We prove that the number of configuration of 3-D IC floorplans represented by P-SP is less than that of planar floorplans represented by sequence pair (SP) and decreases as the device layer number increases. Moreover, we applied the technique of block position enumeration, which have been successfully used in planar fixed-outline floorplanning, to fixed-outline multi-layer floorplanning. The experimental results demonstrate the efficiency and effectiveness of the proposed method. 相似文献
962.
Herein, we prepare vertical and single crystalline porous silicon nanowires (SiNWs) via a two-step metal-assisted electroless
etching method. The porosity of the nanowires is restricted by etchant concentration, etching time and doping lever of the
silicon wafer. The diffusion of silver ions could lead to the nucleation of silver nanoparticles on the nanowires and open
new etching ways. Like porous silicon (PS), these porous nanowires also show excellent photoluminescence (PL) properties.
The PL intensity increases with porosity, with an enhancement of about 100 times observed in our condition experiments. A
“red-shift” of the PL peak is also found. Further studies prove that the PL spectrum should be decomposed into two elementary
PL bands. The peak at 850 nm is the emission of the localized excitation in the nanoporous structure, while the 750-nm peak
should be attributed to the surface-oxidized nanostructure. It could be confirmed from the Fourier transform infrared spectroscopy
analyses. These porous SiNW arrays may be useful as the nanoscale optoelectronic devices. 相似文献
963.
964.
综述国内外多晶硅的生产工艺及尾气处理方法的研究进展,探讨生产多晶硅的常用6种工艺及其优缺点,重点阐述多晶硅尾气的分离回收技术、从开路控制到闭路控制的发展过程及闭路循环技术的优点。 相似文献
965.
气相色谱仪的常见故障及排除方法 总被引:1,自引:0,他引:1
1气相色谱仪是一种应用十分广泛的有机多组分化学分析仪器 它具有分离效能高,分析速度快,样少,可进行多组分测量等优点。在化工分析中占有十分重要的地位,近80%的原料中控及产品分析任务是由气相色来完成的。但是由于人员素质、样品的性质以及仪器本身等方面的原因,常常出现这样那样的分析故障严重影响了正常的分析。所以掌握一种准确、快速的排除仪器故障的方法非常重要。 相似文献
966.
967.
Yuki Nakashima You Zhou Keisuke Tanabe Souhei Arima Kiyoshi Hirao Tatsuki Ohji Norimitsu Murayama Manabu Fukushima 《Journal of the American Ceramic Society》2023,106(2):1139-1148
Silicon nitride (Si3N4) was prepared from silicon by a sintered reaction-bonded silicon nitride method using yttria and magnesia as sintering additives. Post-sintering (PS) of nitrided compacts was carried out at 1850°C under a nitrogen pressure of 1 MPa. Effect of PS time on microstructure and dielectric breakdown strength (DBS) of the prepared Si3N4 ceramics was evaluated. The DBS was measured using specimens with four different thicknesses (0.30, 0.20, 0.10, and 0.05 mm) in order to examine the thickness dependence. The porosity of the sintered Si3N4 decreased by prolonging the PS time, and the full density could be achieved at the PS time of over 6 h. After full densification, rod-like β-Si3N4 grains grew up, and their maximum grain size increased from 45.1 to 154.7 μm by prolonging the PS time from 6 to 48 h. The DBS of the thick Si3N4 substrates (0.30 mm) showed little variation from 35.4 to 47.0 kV/mm, regardless of the PS time. On the other hand, that of the thin ones (0.05 mm) dramatically decreased from 99.5 to 9.8 kV/mm with increased the PS time from 6 to 48 h. Because the DBS sharply decreased at the thin substrate sintered for longer time in which some large-elongated grains might span the substrate thickness-wise throughout, it was inferred that the interface between β-Si3N4 grains and grain boundary phase/intergranular glassy films might be a path of the dielectric breakdown. 相似文献
968.
Tianhao Li Wei Zhang Liantai Duan Ke Chen Qing Huang Yinsheng Li Zhengren Huang Liu He Yujie Song 《Journal of the American Ceramic Society》2023,106(6):3329-3335
Trimethylsilyl-substituted polysilazanes were designed and successfully synthesized. They were used to fabricate high-purity stoichiometric Si3N4 ceramics through pyrolysis process. Trimethylsilyl groups improved the stability of polysilazanes and easily escaped during pyrolysis, which effectively reduced oxygen and carbon content in the final polymer-derived Si3N4. The C content of Si3N4 ceramic was below 0.06 wt%, and the O content was below 1.2 wt%. The Si3N4 ceramics remained amorphous up to 1400°C, yet they were completely transformed into α-Si3N4 at 1500°C. Synergistic effect from low oxygen and carbon content contributed to highly stable amorphous state of Si3N4 till high temperatures. This amorphous Si3N4 ceramics could be used in cutting-edge technology where high purity is compulsory. 相似文献
969.
α-Si3N4 powder was prepared by combustion synthesis method. The propagation characteristics of combustion wave were investigated by thermocouple temperature measurement and “resistance—combustion wave displacement response device.” The results show that the combustion reaction takes place in a narrow area, and there is a maximum temperature gradient of 180°C/mm in the combustion front. The “resistance—combustion wave displacement response device” was innovatively used to realize the in situ measurement of combustion wave propagation process. The test results showed the pulse combustion mode in which the combustion front took 10 s as a cycle, and the quantitative data of Si–N2 discrete combustion characteristics were obtained for the first time. 相似文献
970.