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   179篇
  免费   7篇
  国内免费   4篇
电工技术   2篇
化学工业   42篇
金属工艺   2篇
机械仪表   1篇
建筑科学   4篇
能源动力   16篇
轻工业   11篇
水利工程   2篇
石油天然气   5篇
无线电   27篇
一般工业技术   40篇
冶金工业   23篇
原子能技术   1篇
自动化技术   14篇
  2023年   4篇
  2022年   4篇
  2021年   9篇
  2020年   8篇
  2019年   5篇
  2018年   8篇
  2017年   5篇
  2016年   16篇
  2015年   3篇
  2014年   11篇
  2013年   17篇
  2012年   8篇
  2011年   12篇
  2010年   9篇
  2009年   10篇
  2008年   11篇
  2007年   7篇
  2006年   3篇
  2005年   4篇
  2004年   5篇
  2003年   2篇
  2002年   1篇
  2001年   3篇
  1999年   4篇
  1998年   4篇
  1997年   3篇
  1996年   1篇
  1995年   4篇
  1994年   3篇
  1993年   1篇
  1991年   1篇
  1988年   1篇
  1985年   3篇
排序方式: 共有190条查询结果,搜索用时 15 毫秒
41.
With more than 2000 wound care products on the market, choosing an appropriate dressing for the geriatric patient can prove to be a difficult task. Age-related changes in skin structure and decreased resistance to noxious stimuli in the environment place the elderly patient at higher risk for wound complications. Understanding the principles of moist wound healing and how dressing materials can be used to promote healing outcomes gives the clinician a foundation upon which to base treatment decisions. Assigning products to generic dressing categories further facilitates dressing selection, allowing the treatment protocol to be individualized to the patient, the wound, and the setting.  相似文献   
42.
43.
This paper presents a generalized solution to the symbol error probability (SEP) integral containing the product of two Gaussian Q‐functions . Numerical integration technique is first used to approximate the polar form of as a sum of exponentials. This approximation is then used to derive a closed‐form solution to the related SEP integral. Due to the exponential nature of the approximation, solution to the integral is expressed in terms of moment generating function (MGF) of a fading distribution. Therefore, the solution to integral exists for all fading distributions which have well‐defined MGF. The mathematical complexity of the proposed solution is directly proportional to the complexity of MGF expression. For most of the fading models, the corresponding MGF involves power or exponential functions, which guarantees algebraic simplicity of the proposed solution. Further, this generalized solution is used to evaluate the SEP of various modulation schemes over different fading channels. Various computer simulations run in MATLAB for wide range of scenarios confirm the accuracy of the proposed approximation and solution.  相似文献   
44.
The present study provided an evidence for selective changes of the fatty acid methyl esters (FAMEs) of Canavalia seeds and the low doses of electron beam irradiation (EBI; 2.5 and 5 kGy) serve as hormetic doses for selective enhancement of fatty acids. The total lipids and FAMEs of irradiated Canavalia cathartica and Canavalia maritima seeds of the coastal sand dunes of Southwest India were assessed using soxhlet extraction and chloroform–methanol–water extraction (Bligh and Dyer) methods followed by gas chromatography. As the EBI dose increased, total lipid extraction decreased by soxhlet method in seeds of C. cathartica, while it was reverse in C. maritima. Among the doses, 5 and 10 kGy resulted in the highest extraction of lipid by the Bligh and Dyer method in C. maritima and C. cathartica, respectively. A great variation in FAMEs profile of Canavalia seeds subjected to EBI was seen by the soxhlet and Bligh and Dyer methods of extraction. The EBI increased saturated fatty acids in both the seeds. The unsaturated fatty acids were decreased by EBI based on the soxhlet extraction (except for 15 kGy in C. maritima), while a dose-dependent increase was shown by the Bligh and Dyer method on attaining the highest at the doses 5 kGy (C. maritima) and 10 kGy (C. cathartica). The changes in medium chain fatty acids, long chain saturated fatty acids, mono- and polyunsaturated fatty acids, and ratios of fatty acids were dependent on the seed material, the dose EBI, and the method of extraction.  相似文献   
45.
Single nucleotide polymorphisms (SNPs) can play a direct or indirect role in phenotypic expression in food allergy pathogenesis. Our goal was to quantitate the expression of SNPs in relevant cytokines that were expressed in food allergic patients. SNPs in cytokine genes IL-4 and IL-10 are known to be important in IgE generation and regulation. We examined IL-4 (C-590T), IL-4Rα (1652A/G) and IL-10 (C-627A) SNPs using real-time PCR followed by restriction fragment length polymorphism (RFLP) analysis. Our results show that the AA, AG and GG genotypes for IL-4Rα (1652A/G) polymorphisms were statistically different in radioallergosorbent test (RAST) positive versus negative patients, and although no statistically significant differences were observed between genotypes in the IL-4 (C-590T) and IL-10 (C-627A) SNPs, we observed a significant decrease in IL-4 (C-590T) gene expression and increase in IL-4Rα (1652A/G) and IL-10 (C-627A) gene expression between RAST+ versus RAST? patients, respectively. We also observed significant modulation in the protein expression of IL-4 and IL-10 in the serum samples of the RAST+ patients as compared to the RAST? patients indicating that changes in SNP expression resulted in altered phenotypic response in these patients.  相似文献   
46.
47.
A thermochemical water-splitting cycle representing a modification of the classical sulphur–iodine cycle is proposed. To decrease the energetic demand, increasing the cycle energy efficiency, the distillation of the iodine phase was replaced with the evaporation of the excess of water and iodine. This was obtained by neutralizing the hydrogen iodide in the iodine phase with nickel oxide. In such a way water and iodine can be simply recovered by evaporation leaving nickel iodide as solid phase. The nickel iodide is decomposed to obtain nickel metal and hydrogen is produced by reaction of the metal with sulphuric acid. The nickel sulphate, obtained after hydrogen production, is decomposed to generate sulphur dioxide (used as the reagent in the Bunsen reaction) and nickel oxide (that is recycled). To validate the cycle effectiveness the proposed reactions have been carried out. Crystalline solid materials have been identified by XRD diffraction. Powders morphology was studied by scanning electron microscopy and energy dispersive X-ray. Thermodynamics studies were carried out by thermogravimetric and differential thermal analysis. Finally an energy balance to evaluate the theoretical energy efficiency was computed.  相似文献   
48.
The Journal of Supercomputing - A smart intuitionistic fuzzy-based framework is designed to facilitate adaptability by providing continuous changes in the size of time slice to scheduler at run...  相似文献   
49.
50.
Osteoarthritis (OA) is a common debilitating joint disorder, affecting large sections of the population with significant disability and impaired quality of life. During OA, functional units of joints comprising cartilage and subchondral bone undergo uncontrolled catabolic and anabolic remodeling processes to adapt to local biochemical and biological signals. Changes in cartilage and subchondral bone are not merely secondary manifestations of OA but are active components of the disease, contributing to its severity. Increased vascularization and formation of microcracks in joints during OA have suggested the facilitation of molecules from cartilage to bone and vice versa. Observations from recent studies support the view that both cartilage and subchondral bone can communicate with each other through regulation of signaling pathways for joint homeostasis under pathological conditions. In this review we have tried to summarize the current knowledge on the major signaling pathways that could control the cartilage-bone biochemical unit in joints and participate in intercellular communication between cartilage and subchondral bone during the process of OA. An understanding of molecular communication that regulates the functional behavior of chondrocytes and osteoblasts in both physiological and pathological conditions may lead to development of more effective strategies for treating OA patients.  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