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   57篇
  免费   1篇
  国内免费   2篇
电工技术   3篇
化学工业   15篇
金属工艺   1篇
机械仪表   1篇
能源动力   16篇
轻工业   4篇
无线电   3篇
一般工业技术   12篇
冶金工业   1篇
自动化技术   4篇
  2023年   1篇
  2022年   2篇
  2021年   4篇
  2018年   3篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   1篇
  2013年   2篇
  2012年   2篇
  2011年   5篇
  2009年   1篇
  2008年   6篇
  2007年   9篇
  2002年   2篇
  2001年   3篇
  1999年   2篇
  1998年   2篇
  1996年   1篇
  1993年   1篇
  1991年   1篇
  1984年   1篇
  1983年   1篇
  1981年   1篇
  1979年   1篇
  1976年   1篇
  1973年   1篇
  1972年   2篇
排序方式: 共有60条查询结果,搜索用时 218 毫秒
1.
The coevolution of genomics and proteomics has led to advancements in the field of diagnosis and molecular mechanisms of disease. Proteomics is now stepping into the field of obstetrics, where early diagnosis of pregnancy complication such as preeclampsia (PE) is imperative. PE is a multifactorial disease characterized by hypertension with proteinuria, which is a leading cause of maternal and neonatal morbidity and mortality occurring in 5-7% of pregnancies worldwide. This review discusses the probable molecular mechanisms that lead to PE and summarizes the proteomics research carried out in understanding the pathogenicity of PE, and for identifying the candidate biomarker for diagnosis of the disease.  相似文献   
2.
An automatic algorithm is presented for reducing the bandwidth of symmetric sparse connectivity matrices. The procedure takes an arbitrary input sequence and creates an optimal bandwidth for complex network systems by renumbering the node labels. Thus, considerable improvement for computer storage and time is achieved in the solution of the systems. A large number of examples is presented to demonstrate the reliability and the efficiency of the method.  相似文献   
3.
Aluminum nitride and oxy-nitride thin films have been deposited on Si(100) substrates at temperatures of 300-350K by gas-phase excimer laser photolysis at 193 nm. The precursors used for this deposition process are trimethylamine alane and ammonia. The properties of these laser-deposited films were studied using scanning electron microscopy, energy dispersive x-ray analysis, and x-ray diffraction. X-ray photoelectron spectroscopy has been extensively used to provide information regarding the chemical compositions on the surface and in the bulk of these laser deposited films, as well as on the chemical states of the components of the films. Well-adhering, smooth, amorphous films of AlN are obtained at a substrate temperature of 350K using this technique.  相似文献   
4.
A differentiation between free carboxyl and various lactone groups in oxycelluloses was carried out based on the variation in their reaction rates with KI–KIO3 solution. An attempt has been made to identify the various lactone groups present by comparison of the results of different oxycelluloses as well as study on some model compounds. A characteristic and group spectrum was determined for each oxycellulose. On blocking the free carboxyl groups by zinc acetate treatment, the results for the nature and amounts of various lactones present are in good agreement with the results for oxycelluloses themselves. Sodium borohydride treatment for 120 hr has been found to be incapable of reducing all the lactones present. An appreciable decrease in the value for glucono-δ-lactone was observed, whiles glucuronic acid lactone was only partially attacked. Treatment with chlorous acid resulted in an increase in the values for free carboxyl as well as lactones for all oxycelluloses.  相似文献   
5.
Multimedia Tools and Applications - Breast tumour is one of the leading causes of death among women worldwide. Researchers are working hard to develop early and improved detection tools for breast...  相似文献   
6.
The effect of addition of elastomeric modifiers on the adhesive properties like lap shear strength and T‐peel strength of an addition curable, maleimide functional novolac phenolic resin (PMF), self‐cured and cocured with a novolac epoxy resin, was studied using aluminium adherends. The modifiers used were (1) two grades of carboxyl terminated butadiene acrylonitrile copolymer (CTBN) of different molecular weights, (2) a low molecular weight, epoxidized hydroxyl‐terminated polybutadiene, and (3) a high molecular weight acrylate terpolymer containing pendant epoxy functionality. The adhesive properties, when examined as a function of the varying concentrations of the additives, ranging from 10 to 30 parts per hundred parts (phr) of the resin, were found to depend on the nature of the matrix being modified as well as on the nature and concentration of the elastomer. The adhesive properties at ambient temperature of the self‐cured, highly brittle PMF resin were dramatically improved by the inclusion of all the elastomers, the increase being substantial in the case of high molecular weight CTBN. For the more rigid, less ductile, epoxy‐cured PMF system, the adhesive properties were marginally improved by the high molecular weight CTBN, whereas the other elastomers were practically ineffective. For both self‐cured and epoxy‐cured PMF systems, the inclusion of these elastomers generally decreased the high‐temperature adhesive properties, implying impairment of thermal characteristics, evidenced also from their dynamic mechanical spectra. The presence of phase‐separated elastomer particles in the modified systems has been evidenced from scanning electron micrographs. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2321–2332, 1999  相似文献   
7.
The inorganic–organic hybrid maghemite (γ-Fe2O3)/polypyrrole (PPy) was synthesized and evaluated as cathode-active material for room temperature lithium batteries. The nanometer-sized core–shell structure of the hybrid consisting of the maghemite core with surface modified by PPy was evidenced from the morphological examination. The cathode fabricated with the as-prepared hybrid material delivered an initial discharge capacity of 233 mAh g−1 and a reversible capacity of ∼62 mAh g−1 after 50 charge–discharge cycles. A much higher performance with an initial discharge capacity of 378 mAh g−1 and a reversible capacity of ∼100 mAh g−1 was achieved with the cathode based on the segregated active material, which was obtained by subjecting the as-prepared hybrid material to an additional ball-milling process. The study demonstrates the promising lithium insertion characteristics of the nanometer-sized core–shell maghemite/PPy particles prepared under optimized conditions for application in secondary batteries.  相似文献   
8.
Many studies, both experimental and numerical, were devoted to the electric current of corona discharge and some mathematical models were proposed to express it. As it depends on several parameters, it is difficult to find a theoretical or an experimental formula, which considers all the factors. So we opted for the methodology of experimental designs, also called Tagushi’s methodology, which represents a powerful tool generally employed when the process has many factors to consider. The objective of this paper is to model current using this experimental methodology. The factors considered were geometrical factors (interelectrode interval, surface of the grounded plane electrode, curvature radius of the point electrode), climatic factors (temperature and relative humidity), and applied high voltage. Results of experiments made it possible to obtain mathematical models and to analyse the interactions between all factors.  相似文献   
9.
Fraud Transactions are haunting the economy of many individuals with several factors across the globe. This research focuses on developing a mechanism by integrating various optimized machine-learning algorithms to ensure the security and integrity of digital transactions. This research proposes a novel methodology through three stages. Firstly, Synthetic Minority Oversampling Technique (SMOTE) is applied to get balanced data. Secondly, SMOTE is fed to the nature-inspired Meta Heuristic (MH) algorithm, namely Binary Harris Hawks Optimization (BinHHO), Binary Aquila Optimization (BAO), and Binary Grey Wolf Optimization (BGWO), for feature selection. BinHHO has performed well when compared with the other two. Thirdly, features from BinHHO are fed to the supervised learning algorithms to classify the transactions such as fraud and non-fraud. The efficiency of BinHHO is analyzed with other popular MH algorithms. The BinHHO has achieved the highest accuracy of 99.95% and demonstrates a more significant positive effect on the performance of the proposed model.  相似文献   
10.
A novel, addition-curable maleimide-functional novolac phenolic resin was evaluated for adhesive properties such as lap shear strength and T-peel strength using aluminium adherends, when thermally self-cured and cocured with epoxy resins. The adhesive properties of the self-cured resin, although inferior at ambient temperature, improved at high temperature and were found to depend on the cure conditions. When cocured with epoxy resin, the adhesive properties improved significantly and showed a strong dependence on the nature of the epoxy resin used, on the stoichiometry of the reactants, on the concentration of imide groups in the phenolic resin, and on the extent of polymerization of the maleimide groups. Optimum adhesive properties were obtained for novolac resins with a moderate concentration of maleimide groups, taken on a 1 : 1 hydroxyl–epoxy stoichiometry with a novolac epoxy resin. In comparison to the conventional novolac, the imide–novolac contributed to improved adhesion and better adhesive property retention at higher temperature when cured with the novolac–epoxy resin. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 695–705, 1999  相似文献   
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