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   152篇
  免费   2篇
  国内免费   2篇
电工技术   2篇
化学工业   44篇
金属工艺   5篇
机械仪表   3篇
能源动力   1篇
轻工业   9篇
石油天然气   2篇
无线电   7篇
一般工业技术   22篇
冶金工业   21篇
原子能技术   2篇
自动化技术   38篇
  2022年   7篇
  2021年   4篇
  2020年   1篇
  2018年   3篇
  2017年   3篇
  2016年   5篇
  2015年   2篇
  2014年   4篇
  2013年   11篇
  2012年   13篇
  2011年   7篇
  2010年   5篇
  2009年   10篇
  2008年   4篇
  2007年   4篇
  2006年   2篇
  2005年   3篇
  2004年   5篇
  2002年   4篇
  2001年   3篇
  2000年   4篇
  1999年   3篇
  1998年   7篇
  1997年   4篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   4篇
  1992年   3篇
  1991年   4篇
  1990年   6篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1984年   3篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1977年   1篇
  1973年   1篇
  1971年   1篇
  1957年   1篇
排序方式: 共有156条查询结果,搜索用时 31 毫秒
1.
The separation of PVC from contaminants is one of the most important steps in recycling PVC. Earlier works have shown that one can separate PVC from other polymers by using the X-ray fluorescence technique. However, in many cases, even after careful separation, there is a remaining impurity level of about 0.1% due to the limitations of the separation processes. In many applications, impurities, particularly nonmeltables, cause defects in the PVC matrix and must be removed for best performance and appearance. Melt filtration appears to be the best technique to remove the nonmeltable impurities.  相似文献   
2.
Soft tissue infections are among the rare manifestations of extra intestinal salmonellosis and occur more frequently in immunocompromised patients. Herein we report a case of a 51-year-old white male with type II. diabetes mellitus, diagnosed with supraclavicular abscess caused by Salmonella enteritidis. The patient denied any gastrointestinal symptoms, and stool cultures were negative. After incision, drainage, and administration of intravenous ampicillin (4 x 1.5 g/day for two weeks) the patient recovered completely. To our knowledge, this is the first reported case of cervical soft tissue abscess caused by Salmonella enteritidis without preceding gastrointestinal symptoms. We feel that the presence of diabetes was a risk factor for developing the infection.  相似文献   
3.
The multi-orientation occurs frequently in ancient handwritten documents, where the writers try to update a document by adding some annotations in the margins. Due to the margin narrowness, this gives rise to lines in different directions and orientations. Document recognition needs to find the lines everywhere they are written whatever their orientation. This is why we propose in this paper a new approach allowing us to extract the multi-oriented lines in scanned documents. Because of the multi-orientation of lines and their dispersion in the page, we use an image meshing allowing us to progressively and locally determine the lines. Once the meshing is established, the orientation is determined using the Wigner–Ville distribution on the projection histogram profile. This local orientation is then enlarged to limit the orientation in the neighborhood. Afterward, the text lines are extracted locally in each zone basing on the follow-up of the orientation lines and the proximity of connected components. Finally, the connected components that overlap and touch in adjacent lines are separated. The morphology analysis of the terminal letters of Arabic words is here considered. The proposed approach has been experimented on 100 documents reaching an accuracy of about 98.6%.  相似文献   
4.
Bela Liptak 《软件》2010,(4):60-60,62
寻找替代能源的来源,是美国在新世纪面临的一个挑战。目前,美国军队每年的国防开支约1万亿美元,其中一部分用于保护石油供应。但这样并不能提供一个永久性的解决方案。  相似文献   
5.
Deployment of embedded technologies is increasingly being examined in industrial supply chains as a means for improving efficiency through greater control over purchase orders, inventory and product related information. Central to this development has been the advent of technologies such as bar codes, Radio Frequency Identification (RFID) systems, and wireless sensors which when attached to a product, form part of the product’s embedded systems infrastructure. The increasing integration of these technologies dramatically contributes to the evolving notion of a “smart product”, a product which is capable of incorporating itself into both physical and information environments. The future of this revolution in objects equipped with smart embedded technologies is one in which objects can not only identify themselves, but can also sense and store their condition, communicate with other objects and distributed infrastructures, and take decisions related to managing their life cycle. The object can essentially “plug” itself into a compatible systems infrastructure owned by different partners in a supply chain. However, as in any development process that will involve more than one end user, the establishment of a common foundation and understanding is essential for interoperability, efficient communication among involved parties and for developing novel applications. In this paper, we contribute to creating that common ground by providing a characterization to aid the specification and construction of “smart objects” and their underlying technologies. Furthermore, our work provides an extensive set of examples and potential applications of different categories of smart objects.  相似文献   
6.
In the analysis of farinographic curves, it has been determined that the farinogram area is a very reliable indicator of the quality of wheat flour, if it has been measured 12 min from the achievement of the maximum. In such a way, the dough development time, which can considerably influence the size of the farinographic curve, if it has been measured 15 min after the farinograph has been set in motion, has been eliminated. Quantitative relations between one of the most important characteristics of the farinogram – the farinogram area, and the determined dough characteristics related to dough quality which can be registrated by means of the extensogram, have been determined: , where Afar = farinogram area measured 12 min from the achievement of the maximum, E = dough extensibility, A = area of the extensogram, k′ = represents the farinographic area when the ratio unit value is $ \frac{{{\rm E}^2 }}{{\rm A}}$, k?′ = 4.18 and standard deviation s = 0.214. This determined relation gives a new approach to the farinographic curve interpretation and stresses the new importance of the farinograph as an instrument for physical testing of wheat flour quality.  相似文献   
7.
Data Envelopment Analysis (DEA) is one of the methods that have been proposed to determine the weights in a ranked voting system. DEA solves one model corresponding to each candidate and evaluates candidates with their own weights. However, sometimes solving only one model, and evaluating the candidates based on a common set of weights, is preferred. In this paper, some drawbacks of existing models are explained and new approaches for determining a common set of weights are proposed. Numerical examples are utilized to illustrate the content of the paper.  相似文献   
8.
Numerous recommendation approaches are in use today. However, comparing their effectiveness is a challenging task because evaluation results are rarely reproducible. In this article, we examine the challenge of reproducibility in recommender-system research. We conduct experiments using Plista’s news recommender system, and Docear’s research-paper recommender system. The experiments show that there are large discrepancies in the effectiveness of identical recommendation approaches in only slightly different scenarios, as well as large discrepancies for slightly different approaches in identical scenarios. For example, in one news-recommendation scenario, the performance of a content-based filtering approach was twice as high as the second-best approach, while in another scenario the same content-based filtering approach was the worst performing approach. We found several determinants that may contribute to the large discrepancies observed in recommendation effectiveness. Determinants we examined include user characteristics (gender and age), datasets, weighting schemes, the time at which recommendations were shown, and user-model size. Some of the determinants have interdependencies. For instance, the optimal size of an algorithms’ user model depended on users’ age. Since minor variations in approaches and scenarios can lead to significant changes in a recommendation approach’s performance, ensuring reproducibility of experimental results is difficult. We discuss these findings and conclude that to ensure reproducibility, the recommender-system community needs to (1) survey other research fields and learn from them, (2) find a common understanding of reproducibility, (3) identify and understand the determinants that affect reproducibility, (4) conduct more comprehensive experiments, (5) modernize publication practices, (6) foster the development and use of recommendation frameworks, and (7) establish best-practice guidelines for recommender-systems research.  相似文献   
9.
Ever since continuous casting was introduced, nozzle clogging has been a recurring subject of metallurgical research and publications. Nozzle clogging is caused by the deposition of non‐metallic inclusions – on the casting equipment – which are solid at the temperature of casting. Calcium treatment already represents a possible solution to eliminate this phenomenon, but there are special steel grades which do not allow its application either because they are price sensitive or for certain other reasons.3 Cleaning the steel melt by agitation is an alternative solution, but it has time constraints due to the cooling of the melt. Over extensive cooling can be prevented by heating the melt (in ladle), but its introduction and operational costs per heat are often too high for an individual steelmaking plant to afford. The goal of our research is to find metallurgical solution to reduce the rate of nozzle clogging in plants which do not possess a ladle furnace and the time devoted to treatment or the price of the product do not allow Ca‐treatment to be applied.  相似文献   
10.
Breast cancer (BC) is a malignant neoplasia with the highest incidence and mortality rates in women worldwide. Currently, therapies include surgery, radiotherapy, and chemotherapy, including targeted therapies in some cases. However, treatments are often associated with serious adverse effects. Looking for new options in BC treatment, we evaluated the therapeutic potential of cold atmospheric plasma (CAP) in two cell lines (MCF7 and HCC1806) with distinct histological features. Apoptosis seemed to be the most prevalent type of death, as corroborated by several biochemical features, including phosphatidylserine exposure, the disruption of mitochondrial membrane potential, an increase in BAX/BCL2 ratio and procaspase 3 loss. Moreover, the accumulation of cells in the G2/M phase of the cell cycle points to the loss of replication ability and decreased survival. Despite reported toxic concentrations of peroxides in culture media exposed to plasma, intracellular peroxide concentration was overall decreased accompanying a reduction in GSH levels shortly after plasma exposure in both cell lines. In HCC1806, elevated nitric oxide (NO) concentration accompanied by reduced superoxide levels suggests that these cells are capable of converting plasma-derived nitrites into NO that competes with superoxide dismutase (SOD) for superoxide to form peroxinitrite. The concomitant inhibition of the antioxidative activity of cells during CAP treatment, particularly the inhibition of cytochrome c oxidase with sodium azide, synergistically increased plasma toxicity. Thus, this in vitro research enlightens the therapeutic potential of CAP in the treatment of breast cancer, elucidating its possible mechanisms of action.  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