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   273篇
  免费   10篇
电工技术   1篇
化学工业   63篇
金属工艺   3篇
机械仪表   6篇
建筑科学   10篇
矿业工程   3篇
能源动力   3篇
轻工业   26篇
水利工程   2篇
石油天然气   2篇
无线电   15篇
一般工业技术   43篇
冶金工业   41篇
自动化技术   65篇
  2023年   6篇
  2022年   18篇
  2021年   21篇
  2020年   6篇
  2019年   9篇
  2018年   6篇
  2017年   10篇
  2016年   8篇
  2015年   7篇
  2014年   12篇
  2013年   16篇
  2012年   13篇
  2011年   20篇
  2010年   7篇
  2009年   15篇
  2008年   17篇
  2007年   8篇
  2006年   8篇
  2005年   14篇
  2004年   11篇
  2003年   3篇
  2002年   7篇
  2001年   3篇
  2000年   5篇
  1999年   4篇
  1998年   7篇
  1997年   5篇
  1995年   3篇
  1994年   5篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1986年   2篇
  1984年   1篇
  1983年   1篇
  1978年   1篇
排序方式: 共有283条查询结果,搜索用时 812 毫秒
121.
122.
Unlocking the secrets of the brain is a task fraught with complexity and challenge – not least due to the intricacy of the circuits involved. With advancements in the scale and precision of scientific technologies, we are increasingly equipped to explore how these components interact to produce a vast range of outputs that constitute function and disease. Here, an insight is offered into key areas in which the marriage of neuroscience and nanotechnology has revolutionized the industry. The evolution of ever more sophisticated nanomaterials culminates in network‐operant functionalized agents. In turn, these materials contribute to novel diagnostic and therapeutic strategies, including drug delivery, neuroprotection, neural regeneration, neuroimaging and neurosurgery. Further, the entrance of nanotechnology into future research arenas including optogenetics, molecular/ion sensing and monitoring, and piezoelectric effects is discussed. Finally, considerations in nanoneurotoxicity, the main barrier to clinical translation, are reviewed, and direction for future perspectives is provided.  相似文献   
123.
Children’s guilt associated with transgressions and their capacity for effortful control are both powerful forces that inhibit disruptive conduct. The authors examined how guilt and effortful control, repeatedly observed from toddlerhood to preschool age, jointly predicted children’s disruptive outcomes in 2 multimethod, multitrait longitudinal studies (Ns = 57 and 99). Disruptive outcomes were rated by mothers at 73 months (Study 1) and mothers, fathers, and teachers at 52 and 67 months (Study 2). In both studies, guilt moderated effects of effortful control: For highly guilt-prone children, variations in effortful control were unrelated to future disruptive outcomes, but for children who were less guilt prone, effortful control predicted such outcomes. Guilt may inhibit transgressions through an automatic response due to negative arousal triggered by memories of past wrongdoing, regardless of child capacity for deliberate inhibition. Effortful control that engages a deliberate restraint may offset risk for disruptive conduct conferred by low guilt. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
124.
Corn cobs are major byproduct of maize processing industries. For value addition of maize byproducts, the present paper aims at extracting xylan from corn cobs and subsequent production of xylooligosaccharides (XOS). Compositional determination of corn cobs revealed 38.78% hemicellulose, 27.71% cellulose and 9.4% lignin. Recovery of xylan increased with increasing concentration of alkali during extraction. The extracted xylan was subjected to acidic hydrolysis to yield XOS. HPLC analysis of hydrolysate revealed increased production of XOS with time, but prolonged incubation resulted in higher amount of xylose. Four probiotic strains were used for undertaking in vitro evaluation of the prebiotic efficacy of XOS. XOS ensured higher growth rate for Enterococcus faecium as compared to other probionts, while fructooligosaccharides (FOS) supported higher proliferation of Lactobacillus viridiscens. This method of xylan extraction and production of XOS offers scope for value addition to the corn byproducts.  相似文献   
125.
Industrial cultivation of Rosa damascena and rose oil production is a centuries-old industry based on well-established traditional hand-picking of rose flowers. Here the traditional rose harvesting practices were evaluated through GC/MS analysis of the volatile compounds accumulation in R. damascena flowers at eight different developmental stages, flower buds with arrested development and flowers collected at six daytime points related to flower picking. The accumulation of 80 out of 100 volatile compounds was significantly influenced by the stage of flower development while 62 out of 103 compounds were significantly influenced by the daytime period of flower collection. Principal component analysis showed close clustering of the flower developmental stages and daytime periods preferable for flower harvesting and production of high quality and quantity of rose oil. Taken together the obtained results provide further support to the currently applied traditional rose flower harvesting practices. The possible applications of more precise flower harvesting for fine modulation of rose oil composition and reduction levels of the unwanted compound methyl eugenol are discussed.  相似文献   
126.
Ogden Air Logistics Center (OO-ALC) is the primary facility within the United States Air Force for maintaining and overhauling aircraft landing gear. Aluminum landing gear components are anodized at OO-ALC to provide enhanced corrosion resistance, paint adhesion, and wear resistance; a sodium dichromate sealing operation usually completes the anodizing process. During sealing, the pores of the anodized (oxide) layer are hydrated, which fills the pores and provides improved corrosion resistance. However, this sealer contains hexavalent chromium, which is listed on the Environmental Protection Agency's list of industrial toxic chemicals that are targeted for voluntary reduction or elimination. The specification that outlines the sodium dichromate sealing process delineates three alternative processes that are approved for use: 1) boiling de-ionized water, 2) cobalt acetate, and 3) nickel acetate. While some research to support the use of these and other sealing processes has been gathered under past efforts, additional work must be conducted to fully integrate non-chromate sealers into OO-ALC's anodizing operations. To meet this need, the Air Force Research Laboratory tasked Concurrent Technologies Corporation to identify viable alternatives to the sodium dichromate sealer, conduct testing on these alternatives, and recommend the most promising sealer(s) for implementation based on the test results. This paper will describe the requirements for anodizing and sealing operations within OO-ALC, as well as the sealing technologies that are available and a path forward to demonstrate/validate the most promising alternatives for the specific needs and applications of OO-ALC.  相似文献   
127.
Researchers at the South African Medical Research Council used the Bangkok Declaration, Thailand, 2009, as a guideline for their food composition activities. The vision is to build a comprehensive food composition database for the country. Activities are directed at increasing the number of food items with country-specific nutrient information; encouraging research organisations, universities and the food industry to become involved in nutrient data generation and the generation of yield factors for South African dishes. The introduction of the South African Food Data System (SAFOODS) website and a symposium were major food composition activities. Educating users on the correct application of food composition data is an important endeavour. The national South African Food Data Advisory Group (SAFDAG) formed in 2008, advises and supports food composition activities at SAFOODS. In conclusion, with the support of SAFDAG, SAFOODS activities are aimed at compiling a country-specific food composition database and promoting its scientific use.  相似文献   
128.
We review the solid‐state physics approach to electronic and optical properties of conducting polymers, and bring together the languages of solid‐state theory for polymers and the quantum chemistry of oligomers. We consider polymers as generic one‐dimensional semiconductors with specific features of strongly correlated electronic systems. Our model combines the large distance electron–hole motion within an exciton, governed by long‐range Coulomb attraction with strong intramonomer electronic correlations, which results in effective intramonomer electron–hole repulsion. We exploit the dielectric screening to go beyond the single chain picture and to compare excitons for polymers in solutions and in films. Our approach allows the connecting, explaining, exploiting and organizing of such different experimental and numerical findings as shallow singlet and deep triplet excitons in phenylenes, anomaly in singlet–triplet exciton formation ratio, Ag–Bu crossing in polyenes and common 1/N energy dependencies in oligomers. Copyright © 2007 Society of Chemical Industry  相似文献   
129.
Theranostics involves finding the biomarkers of a disease, fighting them through site specific drug delivery and following them for prognosis of the disease. Microneedle array technology has been used for drug delivery and extended for continuous monitoring of analytes present in the skin compartment. We envisage the use of microneedle arrays for future theranostic applications. The potential of combining microneedle array-based drug delivery and diagnostics as part of closed-loop control system for the management of diseases and delivery of precision drugs in individual patients is reported in this paper.  相似文献   
130.
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