首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   93篇
  免费   0篇
电工技术   6篇
化学工业   22篇
建筑科学   1篇
能源动力   4篇
轻工业   2篇
无线电   7篇
一般工业技术   29篇
冶金工业   9篇
原子能技术   3篇
自动化技术   10篇
  2023年   2篇
  2022年   3篇
  2021年   3篇
  2018年   1篇
  2014年   4篇
  2013年   4篇
  2012年   8篇
  2011年   4篇
  2010年   7篇
  2009年   4篇
  2008年   6篇
  2007年   4篇
  2006年   6篇
  2005年   1篇
  2004年   2篇
  2003年   2篇
  2002年   2篇
  2001年   1篇
  2000年   3篇
  1999年   3篇
  1998年   4篇
  1996年   2篇
  1995年   1篇
  1993年   6篇
  1990年   2篇
  1988年   3篇
  1986年   1篇
  1981年   1篇
  1979年   1篇
  1974年   2篇
排序方式: 共有93条查询结果,搜索用时 15 毫秒
11.
We developed a novel image intensifier (II) of an amplified metal-oxide-semiconductor (MOS) imager (AMI) overlaid with electron-bombarded (EB) amorphous silicon (a-Si). The electron bombardment gain (EB gain) was 1500 at an accelerating voltage of 10 kV. Since the multiplication process was free from a phosphorescent screen and a coupling fiber plate as in the conventional II, the resolution was high and the picture quality was good and free from granularity noises, white spots, lag and sticking. As for fatigue of X-ray irradiation, the contrasts of a vertical stripe (Smear) are not detectable and damaged areas in AMI are weak whereas both of those in charge-coupled devices (CCDs) are strong  相似文献   
12.
We proposed a new approach to identify the frequencies of droplet rotation and m=±2 oscillation that degrade the accuracy of surface tension measurement by an oscillating droplet method. Frequencies of droplet rotation and m=±2 oscillation can be identified by a phase unwrapping analysis of time dependence of the deflection angle for the maximum diameter of the droplet image observed from above. The present method was validated, using test data with given frequencies. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res, 37(7): 421–430, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20214  相似文献   
13.
Emulsion spinning has been discussed as a fiber forming process for a long time. At present, however, there are only a few matrix fibers commercially produced in the world. A matrix fiber composed of polyvinyl alcohol and polyvinyl chloride shows excellent flame retardancy which never goes out either by laundering or by dry cleaning and extremely low toxicity of fumes even when forced to burn. This matrix fiber is being used for home furnishings, apparel and industrial fabrics. The coming into force of regulations on children's sleepwear, carpenting, mattresses and blankets in the USA provides this fiber with a great opportunity to open a market into those fields. It has other features including a soft textural feel, moderate moisture regain and abrasion resistance. Special types of this fiber can be vacuum formed by the same manner that is used for thermoplastics molding.  相似文献   
14.
We report that the results of clinical studies on ceftriaxone (CTRX) in respiratory tract infections (RTIs). Clinical efficacies and side effects of CTRX were as follows; 1. Clinical efficacies of CTRX in a total of 61 cases with RTIs were excellent in 11 cases, good in 23, fair in 11, poor in 12 and unknown in 4. Thus the overall clinical efficacy rate was 59.6%. In cases of patients with lung cancers, the efficacy rate was 42.9%. 2. Clinical efficacy rates with once daily dosage were 50.0% with a dose level of 1 g CTRX and 54.8% with that of 2 g CTRX. 3. Side effects were observed in 2 cases (3.1%) and laboratory abnormalities were observed in 1 case (1.6%). They were not serious, however. These data suggest that CTRX is one of the useful cephalosporins in treatment of RTIs.  相似文献   
15.
16.
A simple procedure for measuring the R -curve properties of ceramics by a stable fracture test in three-point bending is described. As a typical case, data are displayed for a Si3N4 material toughened by the presence of acicular grains in situ grown during the sintering process. The fracture mechanics specimen was a single-edge double-notched beam (SEDNB), whose notch was sharpened to a radius of <10 μm in order to reduce the amount of elastic energy stored at its root prior to crack extension. Furthermore, a stabilizer, specially designed for the bending geometry, was used to control crack stability. During stable extension, the crack could be easily arrested at selected locations of the load-displacement curve, the load quickly released, and the stable crack extension directly measured by the die-penetration technique. The crack resistance, K R, of the material was calculated from the measured crack extent and the onset load value before unloading. This method enabled us to precisely monitor the critical load value at which the load-displacement curve deviated from linear behavior, as well as crack extensions from a few tens of micrometers to about 1 mm. As an application of this method, the fracture resistance of a Si3N4 material with rising R -curve behavior was measured and found to increase from about 5.5 to 9.0 MPaμm1/2 within a 0.8-mm extension.  相似文献   
17.
The caffeine-evoked effects on the intracellular Ca2+ concentration ([Ca2+]i) and on the release of dopamine by PC12 cells were investigated. Stimulation by caffeine resulted in a transient Ca2+ release which was followed by a sustained phase of Ca2+ entry through a non-voltage dependent pathway. Treatment with cyclopiazonic acid (CPA) or thapsigargin, inhibitors of the Ca2+ATPase pump of the endoplasmic reticulum, resulted in only a sustained rise in [Ca2+]i in the presence of extracellular Ca2+. Pretreatment of cells with CPA or thapsigargin abolished the subsequent Ca2+ responses to caffeine. Caffeine also evoked the release of dopamine from the cells only in the presence of extracellular Ca2+, which was mimicked by CPA. These results suggest that store-dependent Ca2+ entry evoked by caffeine has an indispensable role in the secretory response in an excitable cell line, PC12 cells.  相似文献   
18.
Growth-induced anisotropy energy coefficients and their super-cooling temperature dependence, both attributed to rare-earth ion-pairs, Kij, and αij, are obtained by analyzing the relationship between growth temperature dependence of uniaxial anisotropy energy, Ku, and garnet compositions. Regression processes were used for analysis. Better agreements are obtained when the newly obtained Kij and αij values are applied to estimate growth-induced anisotropy energy for 24 garnet compositions. The ratio of calculated growth-induced anisotropy energy values to observed values is 0.98 ± 0.12, when newly obtained Kij and αij values are used in place of Eschenfelder's Kij values (0.85 ± 0.24). Appropriate melt compositions, to obtain LPE garnet films with bubble properties which meet device requirements, are easily given by computer simulation using the newly obtained values.  相似文献   
19.
Of the 29 'Streptococcus milleri' strains tested, all thirteen Streptococcus intermedius (DNA homology group 2) strains but none of the thirteen Streptococcus anginosus (group 1) strains produced beta-N-acetylglucosaminidase, beta-N-acetylgalactosaminidase, alpha-N-acetylneuraminidase, beta-galactosidase, alpha-glucosidase, and hyaluronidase. The three Streptococcus constellatus (group 3) strains produced only the latter two. Glycosidase production divided 274 clinical isolates into 103 S. anginosus, 101 S. intermedius, and 70 S. constellatus strains. Generally, strains of S. anginosus and S. intermedius were non-beta-haemolytic. API II and biotype Ia (lactose positive), but the former contained almost all API III strains and belonged to Lancefield group A/serotype a (A/a), -/b, C/c, -/d, -/e, F/f or G/k, and the latter included most of biotype IId (lactose negative) and serovar -/g, -/h, -/i or -/j. S constellatus strains were beta-, alpha- or gamma-haemolytic, of API I or II but mostly biotype Ib (lactose negative), and of F/- or -/b. S. intermedius was a major member of the oral isolates. Non-oral isolates were virtually all S. anginosus (mainly urogenital isolates) or S. constellatus (the other systemic isolates).  相似文献   
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号