全文获取类型
收费全文 | 422篇 |
免费 | 11篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 10篇 |
化学工业 | 65篇 |
金属工艺 | 9篇 |
机械仪表 | 7篇 |
建筑科学 | 5篇 |
矿业工程 | 1篇 |
能源动力 | 12篇 |
轻工业 | 17篇 |
无线电 | 70篇 |
一般工业技术 | 73篇 |
冶金工业 | 112篇 |
原子能技术 | 7篇 |
自动化技术 | 46篇 |
出版年
2023年 | 5篇 |
2022年 | 6篇 |
2021年 | 8篇 |
2020年 | 3篇 |
2019年 | 7篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 9篇 |
2014年 | 7篇 |
2013年 | 19篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 6篇 |
2009年 | 11篇 |
2008年 | 19篇 |
2007年 | 13篇 |
2006年 | 9篇 |
2005年 | 7篇 |
2004年 | 12篇 |
2003年 | 15篇 |
2002年 | 15篇 |
2001年 | 7篇 |
2000年 | 16篇 |
1999年 | 12篇 |
1998年 | 50篇 |
1997年 | 27篇 |
1996年 | 19篇 |
1995年 | 7篇 |
1994年 | 11篇 |
1993年 | 13篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1974年 | 4篇 |
排序方式: 共有434条查询结果,搜索用时 21 毫秒
131.
A 6-month regimen consisting of isoniazid (INH. 0.3-0.5 g).rifampicin (RFP. 0.3-0.45 g).pyrazinamide (PZA. 1.2-2.0 g) and streptomycin (SM. 0.75 g) or ethambutol (EB. 0.75-1.0 g) given for 2 month followed by isoniazid and rifampicin for 4 month is the preferred treatment for patients with fully susceptible organism, who adhere to treatment. Consideration should be given to treating all patients with directly observed treatment. 相似文献
132.
Wakita K. Kotaka I. Asai H. Okamoto M. Kondo Y. Naganuma M. 《Photonics Technology Letters, IEEE》1992,4(1):16-18
Monolithic integration of an InGaAsP/InGaAs multiple quantum well (MQW) distributed-feedback (DFB) laser with a high-speed InGaAs/InAlAs MQW intensity modulator is demonstrated. A 3-dB bandwidth. in excess of 16 GHz and low-drive-voltage operation (4.0 V) for a 20-dB on-off ratio are obtained. Good coupling efficiency between an MQW DFB laser and an MQW modulator is accomplished using hybrid crystal growth of MO-VPE and MBE 相似文献
133.
Shigematsu T Kurosawa MK Asai K 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2003,50(4):376-385
High resolution (from nanometer to subnanometer) stepping drives of a surface acoustic wave motor are presented. It was shown that step displacement was easily controlled by adjusting a number of driving waves, using a steel ball slider equipped with permanent magnet for preload. By means of this open loop control, the step displacement was controlled from centimeter-order to submicrometer-order. In this paper, using a silicon slider equipped with a ball bearing linear guide, the stepping motions of a surface acoustic wave motor were investigated. A laser interferometer equipped with a 2-picometer resolution displacement demodulator was introduced. Motions of the slider ranging from several hundreds of nanometers to several nanometers in each step displacement were observed. Reduction of the driving waves down to 25 cycles, under a 100 V/sub peak/ driving voltage and a 30 N preload condition, generated about 2 nm stepping motion using our experimental setup under an open loop condition. We also demonstrated subnanometer step movements. These experimental results indicated that the surface acoustic wave motor has an ability of subnanometer positioning with a centimeter-level stroke. 相似文献
134.
Characterization of the physicochemical properties of the micelles of platelet-activating factor (C18:0) 总被引:3,自引:0,他引:3
The purpose of this study was to clarify the physicochemical properties of the micelles of platelet-activating factor (PAF; C18:0). The critical micelle concentration (CMC) of PAF (C18:0) was determined (0.20 μM) using fluorescence techniques. The fluidity and the micropolarity of the PAF (C18:0) micelle were similar to those of the micelle of stearoyl lysophosphatidylcholine. 相似文献
135.
The effect of the lipid A analog E5531 on the phospholipid membrane was compared with that of the lipid A from Escherichia coli (EC). E5531 decreased the phase transition temperature of dipalmitoylphosphatidylcholine (DPPC) membrane and increased the fluidity and micropolarity. On the other hand, the effect of EC on the membrane was contradictory. These results suggested that the reason for the difference of biological effects of these two lipid A would be caused by the differences from the effect on the cell membranes. 相似文献
136.
Takata H. Komori S. Tamura T. Asai F. Satoh H. Ohno T. Tokuda T. Nishikawa H. Terada H. 《Solid-State Circuits, IEEE Journal of》1990,25(1):95-99
A high-throughput matching memory (MM) for a data-driven microprocessor is discussed. An MM can be constructed using a hashing memory. However, one of the biggest problems with hashing memory is the necessity for selective processing whenever hashed address conflicts occur. To eliminate this problem, the MM incorporated a small amount of associative memory (32 words×50 b) as well as the hashing memory (512 words×42 b). The matching operation is subdivided into three pipeline stages, all controlled by the elastic pipeline scheme. With this structure, an MM with a high throughput of 100-mega-access/s MM can be realized 相似文献
137.
Kenjiro Asai 《Polymer》1982,23(3):391-394
Mechanism of emergence of high pressure phase of polyethylene is analysed on the thermodynamic stand point: The change in free energy due to pressure increase is calculated for each phase on the basis of the experimental data. The transition temperature and melting point under the increased pressures are estimated and the results obtained are consistent with the observed values. 相似文献
138.
A GaAs 256×1-bit static RAM with 2000 FETs organised in E/D-type DCFL circuits was successfully fabricated. A planar device structure was realised by using selective ion implantation and dielectric intermediate lift-off technology. The access time and the power dissipation were 50 ns and 9.4 mW, respectively. 相似文献
139.
140.
The reaction of cellulose with phosphorous acid in molten urea afforded a white, water-soluble product. The product was a monoester of phosphorous acid, and all the phosphorus residues were in phosphonic form, i.e., cellulose phosphonate. Quantitative addition of acrylonitrile to the P? H bonds in cellulose phosphonate occurred in the presence of sodium ethoxide. By alkali hydrolysis of the adduct, a polyelectrolyte having two different ionization groups, P? OH and COOH, could be prepared. Thermal degradation of three cellulose phosphonates, ammonium cellulose phosphonate (I), ammonium cellulose 2-cyanoethlyphosphonate (II), and ammonium cellulose 2-carboxyethylphosphonate (III), was examined. All three samples decomposed at a temperature around 270°C, but their thermal behaviors were different. Replacement of hydrogen in the phosphonic residue by 2-cyanoethyl and 2-carboxyethyl groups retarded dehydration of cellulose. Sample I had a satisfactory flame retardance; samples II and III were not flame resistant. Reduction of flame retardance may be due to the electron-withdrawing effect of the cyano and carboxyl groups. 相似文献