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   34篇
  免费   0篇
电工技术   1篇
化学工业   13篇
建筑科学   1篇
矿业工程   1篇
能源动力   1篇
轻工业   8篇
无线电   1篇
一般工业技术   3篇
冶金工业   4篇
自动化技术   1篇
  2024年   1篇
  2022年   4篇
  2021年   2篇
  2020年   1篇
  2019年   3篇
  2018年   1篇
  2016年   1篇
  2012年   3篇
  2011年   6篇
  2010年   1篇
  2009年   2篇
  2008年   4篇
  2007年   2篇
  2005年   1篇
  2004年   1篇
  1997年   1篇
排序方式: 共有34条查询结果,搜索用时 14 毫秒
21.
Journal of Applied Electrochemistry - Nowadays, massive NiMo alloys are considered highly active catalysts for the hydrogen evolution reaction (HER) in industrial alkaline electrolysers. Thus, it...  相似文献   
22.
For devices having non-linear contact, load plays a fundamental role. Variations in the characteristics of the load cause change in eigenfrequency and amplitude of the vibration. In most technical applications, this unwanted behaviour is cancelled by the use of control algorithms. However, multiple applications, like bond quality monitoring or chemical and pressure sensors, have found that the load may be characterised by interpreting the change in characteristics of a resonant vibrating device used as a sensor. Surgical resection of tumours is a very difficult task. After localising the tumour by the use of imaging techniques, the resection demands the surgeon to decide where and what to resect based on visual and tactile differentiation of tumour and healthy tissue. Exactness of this process could be enhanced if we can provide the surgeon with a device capable of evaluating mechanical characteristics of the tissue much more accurately than the surgeon himself can do. As the mechanical characteristics of tumour and healthy tissue differ but slightly, the task is to design a system with high sensitivity. Therefore, we have developed a resonant actuator-sensor that allows the differentiation among distinct media that have similar mechanical characteristics to tumour and healthy tissue using a piezoelectric bimorph. The design is based on the detection and evaluation of frequency shift and amplitude variation of the fundamental and higher harmonics using one layer for the resonant excitation of vibration and the other one as the sensing element.  相似文献   
23.
Presence of planar, bulky heterocyclic pendant groups, attached to polymer chains, alters the thermal properties and, once gelled, they modify their rheological properties as well. The authors report generation of stiff gels coming from terpolymers containing 1,2,4‐oxadiazolic pendant groups, obtained by chemical modification of commercial polyacrylonitrile. The gels formed in basic aqueous solutions were compared and the effect of substituents linked to the heterocycles on thermal stability and viscoelastic properties was also analyzed. The structural modifications were followed by FTIR. The potential use of these terpolymers as workover fluids is discussed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   
24.
25.
The receptor-binding assay (RBA) method for the detection of paralytic shellfish poisoning (PSP) toxins was evaluated for its overall performance in comparison with the mouse bioassay (MBA). An initial study to evaluate the effects of filtering shellfish extracts prior to running the RBA indicated no significant difference between filtered and unfiltered extracts on the determined saxitoxin (STX) concentrations. Next, we tested the RBA assay on 295 naturally contaminated mussel tissue samples, ranging in concentrations from 320 µg STX equiv. kg?1 to 13,000 µg STX equiv. kg?1 by MBA. An overall trend was observed with the RBA giving higher results (256 µg STX equiv. kg?1 on average) than the MBA; however, at low concentrations (< 500 µg STX equiv. kg?1) the RBA results were marginally lower. A third study was conducted using spiked mussel tissue analysed by three independent laboratories, two of which performed the RBA and one the MBA. This multi-laboratory study again showed the RBA to give higher results than the MBA; however, it also revealed that STX determination was accurate by the RBA, unlike the MBA. To optimise the assay for efficient usage under regulatory practice, three suggestions have been made: the use of an initial screening plate to separate those samples that exceed the alert level; use of rapid PSP test kits in the field and in the laboratory for screening negative samples and for early detection of toxicity; and use of an alternate commercially available porcine membrane in place of the laboratory-prepared rat membrane homogenate. The large number of samples analysed and the diversity of the tests conducted in this study further support the RBA as an affordable rapid method for STX detection that is also free of the routine sacrifice of live animals.  相似文献   
26.
Electrical and electronic equipments (EEE) have already begun to be accumulated at the garbage dumps. This garbage accumulation brings big danger to the environment and human health. That’s why one should look for exploring the ways to dispose of these wastes and emphasize the waste treatment strategies. Waste treatment strategies also contribute either to local or global economies by creating a new sector and employment opportunities, and by reducing use of scarce resources. In this paper, a linear programming technique for multidimensional analysis of preference (LINMAP) method for solving multi-attribute group decision making (MAGDM) problems with preference information on alternatives in fuzzy environment is developed. The aim is to develop a fuzzy LINMAP model for evaluation and select of a waste treatment strategy for EEE. Thus, three treatment strategy alternatives and eight criteria are determined. The best strategy is selected and the key criterion is found accordingly. The best alternative is found to be treating waste electrical and electronic equipments (WEEE) by reuse and recycling methods.  相似文献   
27.
We report the synthesis of new copolymers from poly(vinyl chloride) (PVC) with 1,2,4‐triazol‐5‐yl‐sulfanyl pendant groups (PVCT) by nucleophilic substitution using microwave energetic sources. By comparing the synthesis of PVCT between microwave and thermal conditions, it was found that the use of microwave‐assisted process led to higher conversion levels than that of the thermal synthesis. Moreover, significant decrease in reaction times was obtained for the microwave assisted synthesis, which avoided secondary reactions. Conversion yields were calculated from elemental analysis and the molecular weighs were analyzed by means of SEC. The molecular structures of the new copolymers were confirmed by FTIR, 13C NMR and 1H NMR spectroscopies. The morphology of the new copolymers was analyzed by SEM. Thermal properties were studied by TGA and DSC techniques. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   
28.
We examine how state-level factors affect greenhouse gas (GHG) reduction policy preference across the United States by analyzing climate action plans (CAPs) developed in 11 states and surveying the CAP advisory group members. This research offers insights into how states approach the problem of choosing emissions-abatement options that maximize benefits and minimize costs, given their unique circumstances and the constellation of interest groups with power to influence state policy. The state CAPs recommended ten popular GHG reduction strategies to accomplish approximately 90% of emissions reductions, but they recommended these popular strategies in different proportions: a strategy that is heavily relied on in one state’s overall portfolio may play a negligible role in another state. This suggests that any national policy to limit GHG emissions should encompass these key strategies, but with flexibility to allow states to balance their implementation for the state’s unique geographic, economic, and political circumstances. Survey results strongly support the conclusion that decisions regarding GHG reductions are influenced by the mix of actors at the table. Risk perception is associated with job type for all strategies, and physical and/or geographic factors may underlie the varying reliance on certain GHG reduction strategies across states.  相似文献   
29.
This study offers a new perspective on the role of relative humidity in strategies to improve the health and wellbeing of office workers. A lack of studies of sufficient participant size and diversity relating relative humidity (RH) to measured health outcomes has been a driving factor in relaxing thermal comfort standards for RH and removing a lower limit for dry air. We examined the association between RH and objectively measured stress responses, physical activity (PA), and sleep quality. A diverse group of office workers (n = 134) from four well-functioning federal buildings wore chest-mounted heart rate variability monitors for three consecutive days, while at the same time, RH and temperature (T) were measured in their workplaces. Those who spent the majority of their time at the office in conditions of 30%-60% RH experienced 25% less stress at the office than those who spent the majority of their time in drier conditions. Further, a correlational study of our stress response suggests optimal values for RH may exist within an even narrower range around 45%. Finally, we found an indirect effect of objectively measured poorer sleep quality, mediated by stress responses, for those outside this range.  相似文献   
30.
We report the acid–base behavior of OATA, an oligomer synthesized from 3‐amino‐1,2,4‐triazole (ATA). We analyze the UV–vis spectroscopy at different media, and we analyze and discuss the acid–base equilibria taking into account tautomeric equilibria at different pH. The low aqueous solubility at neutral pH can be attributed to the neutral form. Indeed, OATA was synthesized in an ordinary filter paper, which can be used as a sensor for ammonia as well as endpoint indication. Using the OATA‐containing paper, ammonia concentrations in a solution as low as 5 ppm could be measured. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  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