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   78篇
  免费   4篇
电工技术   1篇
化学工业   25篇
金属工艺   1篇
建筑科学   1篇
能源动力   1篇
轻工业   13篇
水利工程   1篇
无线电   6篇
一般工业技术   6篇
冶金工业   15篇
自动化技术   12篇
  2023年   2篇
  2022年   5篇
  2021年   3篇
  2020年   8篇
  2019年   2篇
  2016年   3篇
  2015年   2篇
  2014年   1篇
  2013年   3篇
  2012年   5篇
  2011年   7篇
  2010年   2篇
  2009年   7篇
  2008年   6篇
  2007年   3篇
  2006年   1篇
  2005年   2篇
  2001年   1篇
  2000年   2篇
  1998年   1篇
  1997年   2篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
  1992年   1篇
  1991年   3篇
  1990年   1篇
  1989年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1976年   1篇
排序方式: 共有82条查询结果,搜索用时 0 毫秒
31.
Shared feature extraction for nearest neighbor face recognition.   总被引:1,自引:0,他引:1  
In this paper, we propose a new supervised linear feature extraction technique for multiclass classification problems that is specially suited to the nearest neighbor classifier (NN). The problem of finding the optimal linear projection matrix is defined as a classification problem and the Adaboost algorithm is used to compute it in an iterative way. This strategy allows the introduction of a multitask learning (MTL) criterion in the method and results in a solution that makes no assumptions about the data distribution and that is specially appropriated to solve the small sample size problem. The performance of the method is illustrated by an application to the face recognition problem. The experiments show that the representation obtained following the multitask approach improves the classic feature extraction algorithms when using the NN classifier, especially when we have a few examples from each class.  相似文献   
32.
Cyclosporin-A (Cyc-A) stimulates prostanoid (PGI2) synthesis in confluent smooth muscle cells from guinea pig aorta through the release of endogenous fatty acid. Cyc-A, like other stimulatory agents for prostanoids, promotes smooth muscle cell proliferation and prostanoid synthesis in these proliferating cells. Indomethacin, a cyclooxygenase inhibitor, and exogenous arachidonic acid block the Cyc-A effect on cell proliferation.  相似文献   
33.
The main objective of the ISTS project is to develop a simulation-based training system that conducts content training without the human instructor being continuously involved. A prototype for Air Traffic Control (ATC) has been developed by isolating the domain dependent expertise from the generic system. The prototype is modularized to be easily modified, expanded, or adapted to other domains. In order to evaluate a student's performance, a simulation-based training system must be able to accurately interpret student actions. This paper will present a generic paradigm for managing and interpreting the effects of student inputs for an Intelligent Simulation Training System (ISTS).

The Control module is the manager of the ISTS. It is responsible for coordinating the communication between the simulation and the rest of the system. It is also responsible for deciding when and which modules to activate based on a set of prioritized facts. The Interpreter module determines the effects of the student input to the simulation by comparing snapshots of the simulation before and after a student input is executed. It also checks the simulation for late events.  相似文献   

34.
The authors tested effects of a 10-week group cognitive-behavioral stress management intervention among 100 women newly treated for Stage 0-II breast cancer. The intervention reduced prevalence of moderate depression (which remained relatively stable in the control condition) but did not affect other measures of emotional distress. The intervention also increased participants' reports that having breast cancer had made positive contributions to their lives, and it increased generalized optimism. Both remained significantly elevated at a 3-month follow-up of the intervention. Further analysis revealed that the intervention had its greatest impact on these 2 variables among women who were lowest in optimism, at baseline. Discussion centers on the importance of examining positive responses to traumatic events—growth, appreciation of life, shift in priorities, and positive affect—as well as negative responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
35.
The antioxidant capacities of α- and γ-tocopherols (α-E and γ-E) and their quinones (α-EQ and γ-EQ) were determined in non-biological and biological systems. The non-biological system consisted of arachidonic acid [20∶4 (n−6)], the oxidant cumene hydroperoxide, and a Fe3+ catalyst to facilitate malondialdehyde (MDA) formation from lipid peroxides. α-E and γ-E had similar antioxidant capacities in this system. α-EQ also functioned as an antioxidant, while γ-EQ exhibited a crossover effect by functioning as an antioxidant at low concentrations and a prooxidant at high concentrations. Biological lipid peroxidation in smooth muscle cells challenged with 20∶4 (n−6) was measured both by MDA formation in confluent cultures and by cell growth in proliferating cultures. α-E, γ-E and α-EQ had similar antioxidant capacities, but γ-EQ was highly cytotoxic for cells in both confluent and proliferating cultures. Cellular retention of antioxidants was estimated indirectly from MDA formation when cells were loaded with an antioxidant (preincubation) and then incubated for varying periods of time in fresh media containing 20∶4 (n−6). Cellular retention also was measured directly with tritiated α-E and tritiated αEQ. These studies showed that cellular retention decreased in the sequence γ-E>α-E>α-EQ. Thus, cellular retention does not explain the enhanced antioxidant capacity of α-E compared to γ-E that has been reported for animal systems. The antioxidant capacity of αE evidently is enhanced by its metabolism to a quinone which, unlike the quinone from γ-E, functions as a biological antioxidant.  相似文献   
36.
37.
Subarachnoid block is a widely practiced anesthetic technique. With the availability of small-diameter needles and the rises in out-patient surgery, the number of procedures performed with subarachnoid block and short-term local anesthesia have increased. We report two cases of bilateral pain in the lower extremities appearing 20-24 h after intradural anesthesia with 2% hyperbaric lidocaine. We analyze the factors that might have triggered this complication and compare the two patients with 14 others described in the literature. Three points in common were found: the use of hyperbaric lidocaine, administration of the agent through small gauge needles and the performance of out-patient surgery.  相似文献   
38.
Thermal barrier coatings (TBCs) are used to protect underlying metal from heat generated during combustion of fuel, especially in truck engines and jet turbines. These coatings are thin, partially stabilized zirconia, separated from the substrate metal by an interface layer, which serves to enhance bonding and reduce the thermal expansion mismatch between the metal and the ceramic. The reliability of these coatings is currently not predictable. The work described in this paper focused on the use of acoustic emission (AE) as a quality control test for TBCs. The test specimens were commercially sprayed straps. The data show that differences in spraying parameters and microstructure are clearly visible in the emissions during thermal cycling. This work indicates that the failure mechanism can be predicted from the AEs during the first thermal cycle.  相似文献   
39.
Processing conditions must be rigorously controlled in the production of fabric softener because mechanical energy input during the mixing operation may provoke undesirable structural transitions. Hence, ability to control and modify rheological properties of surfactant systems is an important pre‐requisite for many applications of surfactant formulations. Mixtures of a commercial cationic esterquat‐type surfactant and different concentrations of salt (CaCl2) were rheologically and microscopically characterized. Shear‐induced microstructural transitions have been studied in order to control the formation of vesicles, which is undesirable. The addition of salt allows viscosity to be adjusted and provoked a lack of viscoelastic properties. In addition, a shear thickening effect above a specific value of critical shear rate, which is different for each salt concentration, was observed. This is related to the transition from lamellar bilayer to vesicles. This fact was confirmed by hysteresis‐loop experiments, which showed apparent antithixotropic behaviour. Start‐up flow tests indicated that a minimum value for shear rate and a certain shear time are needed for the formation of shear‐induced structures. After this test, the systems showed viscoelastic properties due to the formation of vesicles.  相似文献   
40.
Removing phosphate from alkaline high-level waste sludges at the Department of Energy's Hanford Site in Washington State is necessary to increase the waste loading in the borosilicate glass waste form that will be used to immobilize the highly radioactive fraction of these wastes. We are developing a process which first leaches phosphate from the high-level waste solids with aqueous sodium hydroxide, and then isolates the phosphate by precipitation with calcium oxide. Tests with actual tank waste confirmed that this process is an effective method of phosphate removal from the sludge and offers an additional option for managing the phosphorus in the Hanford tank waste solids. The presence of vibrationally active species, such as nitrate and phosphate ions, in the tank waste processing streams makes the phosphate removal process an ideal candidate for monitoring by Raman or infrared spectroscopic means. As a proof-of-principle demonstration, Raman and Fourier transform infrared (FTIR) spectra were acquired for all phases during a test of the process with actual tank waste. Quantitative determination of phosphate, nitrate, and sulfate in the liquid phases was achieved by Raman spectroscopy, demonstrating the applicability of Raman spectroscopy for the monitoring of these species in the tank waste process streams.  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