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   169篇
  免费   8篇
化学工业   27篇
金属工艺   6篇
机械仪表   1篇
建筑科学   2篇
矿业工程   1篇
能源动力   17篇
轻工业   6篇
水利工程   2篇
无线电   20篇
一般工业技术   19篇
冶金工业   53篇
自动化技术   23篇
  2024年   1篇
  2022年   4篇
  2021年   4篇
  2020年   3篇
  2019年   6篇
  2018年   8篇
  2017年   6篇
  2016年   4篇
  2015年   3篇
  2014年   4篇
  2013年   11篇
  2012年   9篇
  2011年   6篇
  2010年   14篇
  2009年   12篇
  2008年   4篇
  2007年   3篇
  2006年   5篇
  2005年   4篇
  2003年   5篇
  2002年   6篇
  2000年   6篇
  1998年   3篇
  1997年   2篇
  1996年   4篇
  1995年   1篇
  1994年   5篇
  1993年   4篇
  1992年   6篇
  1991年   1篇
  1990年   2篇
  1989年   4篇
  1988年   1篇
  1987年   3篇
  1986年   3篇
  1984年   2篇
  1983年   3篇
  1981年   2篇
  1979年   2篇
  1978年   1篇
排序方式: 共有177条查询结果,搜索用时 203 毫秒
1.
Examined the relationships among social support knowledge, supportive behavior, intimacy with one's spouse, and satisfaction with support provided by one's spouse among 41 Israeli kibbutz couples. The hypothesis that support knowledge and support behavior influence the intimacy between couples and increase satisfaction with spouse's social support efforts was tested. Alternative causal mechanisms are explored with simultaneous equation modeling. Results indicate that satisfaction with social support behavior by one's spouse is mediated entirely by intimacy with one's spouse. Results also indicate that partner's knowledge about social support behavior directly affects intimacy and indirectly generates social support satisfaction independent of actual supportive behavior. The findings do not differ by sex. The consistency of the findings with family behavior exchange theory and implications for marital therapy are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
2.
3.
We present an approach for extracting extremal feature lines of scalar indicators on surface meshes, based on discrete Morse Theory. By computing initial Morse‐Smale complexes of the scalar indicators of the mesh, we obtain a candidate set of extremal feature lines of the surface. A hierarchy of Morse‐Smale complexes is computed by prioritizing feature lines according to a novel criterion and applying a cancellation procedure that allows us to select the most significant lines. Given the scalar indicators on the vertices of the mesh, the presented feature line extraction scheme is interpolation free and needs no derivative estimates. The technique is insensitive to noise and depends only on one parameter: the feature significance. We use the technique to extract surface features yielding impressive, non photorealistic images.  相似文献   
4.
This paper proposes a non-domain-specific metadata ontology as a core component in a semantic model-based document management system (DMS), a potential contender towards the enterprise information systems of the next generation. What we developed is the core semantic component of an ontology-driven DMS, providing a robust semantic base for describing documents’ metadata. We also enabled semantic services such as automated semantic translation of metadata from one domain to another. The core semantic base consists of three semantic layers, each one serving a different view of documents’ metadata. The core semantic component’s base layer represents a non-domain-specific metadata ontology founded on ebRIM specification. The main purpose of this ontology is to serve as a meta-metadata ontology for other domain-specific metadata ontologies. The base semantic layer provides a generic metadata view. For the sake of enabling domain-specific views of documents’ metadata, we implemented two domain-specific metadata ontologies, semantically layered on top of ebRIM, serving domain-specific views of the metadata. In order to enable semantic translation of metadata from one domain to another, we established model-to-model mappings between these semantic layers by introducing SWRL rules. Having the semantic translation of metadata automated not only allows for effortless switching between different metadata views, but also opens the door for automating the process of documents long-term archiving. For the case study, we chose judicial domain as a promising ground for improving the efficiency of the judiciary by introducing the semantics in this field.  相似文献   
5.
The transition from traditional energy sources to renewable has gained popularity and acceptance in recent years. This has been driven mainly by the current level of pollution, global warming, decommission of old nuclear power plants and the increasing cost of conventional energy sources. Nevertheless, one of the many steps to overcome is the seasonality or intermittency of renewable energy sources such as wind power. In recent years, new technologies have come up to address this problem, so the energy can be stored for future purposes. This paper analyses these energy storage alternatives for a specific case in the Columbia River Gorge for wind power. A hierarchical decision model is developed with criteria including political, social, environmental, technical and economical. The main conclusions highlight that the economical and technical criteria are among the most important ones for decision-makers.  相似文献   
6.
In this study, the policy, market conditions and food security of biomass energy sources are assessed for supplying the future needs of Vojvodina. The Autonomous Province of Vojvodina is an autonomous province in Serbia, containing about 27% of its total population according to the 2002 Census. It is located in the northern part of the country, in the Pannonia plain, in southeastern Europe.Vojvodina is an energy-deficient province. Vojvodina also has a large potential for renewable energy, especially energy from biomass (biodiesel and bio-ethanol). The lack of knowledge about renewable energy technologies by most policy-makers, potential consumers, and energy firm managers has played against renewable energy developments. The environmental impacts of programs that encourage biofuel production, farmland land requirements and the impacts on food production are also discussed, considering the life cycle analysis (LCA) as a tool.It is concluded that the rise in the use of biofuels is inevitable and that international cooperation, regulations and certification mechanisms must be established regarding the use of land, the mitigation of environmental and social impacts caused by biofuel production. It is also mandatory to establish appropriate working conditions and decent remuneration for workers of the biofuels production chain.  相似文献   
7.
The paper presents a fluid-porous medium model, developed for stationary 2D predictions of fluidized bed. Dense phase is considered a fixed porous medium, while gas–particle interactions and bubbling phase are modeled regarding balance of friction forces between gas and particles. Like referent measurements, predictions of lateral jet injection into the bed suggest the jet penetration length is strongly affected by fluid velocity at the nozzle outlet, while influences of the nozzle vertical position and inclination angle are not significant. Also, the fluid velocity and the nozzle vertical position exert pronounced effects on mixing rate of components (fuel and oxidizer).  相似文献   
8.
Molecular surfaces play an important role in studying the interactions between molecules. Visualizing the dynamic behavior of molecules is particularly interesting to gain insights into a molecular system. Only recently it has become possible to interactively visualize dynamic molecular surfaces using ray casting techniques. In this paper, we show how to further accelerate the construction and the rendering of the solvent excluded surface (SES) and the molecular skin surface (MSS). We propose several improvements to reduce the update times for displaying these molecular surfaces. First, we adopt a parallel approximate Voronoi diagram algorithm to compute the MSS. This accelerates the MSS computation by more than one order of magnitude on a single core. Second, we demonstrate that the contour‐buildup algorithm is ideally suited for computing the SES due to its inherently parallel structure. For both parallel algorithms, we observe good scalability up to 8 cores and, thus, obtain interactive frame rates for molecular dynamics trajectories of up to twenty thousand atoms for the SES and up to a few thousand atoms for the MSS. Third, we reduce the rendering time for the SES using tight‐fitting bounding quadrangles as rasterization primitives. These primitives also accelerate the rendering of the MSS. With these improvements, the interactive visualization of the MSS of dynamic trajectories of a few thousand atoms becomes for the first time possible. Nevertheless, the SES remains a few times faster than the MSS.  相似文献   
9.
In this study, the policy, market conditions and food security of biomass energy sources are assessed for supplying the future needs of Vojvodina. The Autonomous Province of Vojvodina is an autonomous province in Serbia, containing about 27% of its total population according to the 2002 Census. It is located in the northern part of the country, in the Pannonia plain, in southeastern Europe. Vojvodina is an energy-deficient province. The incentives to invest human and financial resources in the research and development of cleaner bioprocesses are high, considering the benefits which might be achieved in terms of environment protection and manufacturing costs. In the near and medium tenu, the development of bioprocesses for waste recycling and resource recovery might be one of the most viable options, considering much research work has already been done. In Vojvodina, there are technological solutions that biofuels produced in a closed cycle, so that the quantity of waste reduced to a minimum. These solutions include the stillage (remainder after distillation) used for fattening cattle, and cattle excrement to produce biogas and manure as fertilizer. The energy required for the production of bioethanol is obtained combustion lignocelullose residual waste from the production of basic raw materials starch, or biogas. Ash from the burned biomass returned to soil as a source of minerals for plants and replacement of mineral fertilizer. Such a closed cycle is economical for small farms in Vojvodina.  相似文献   
10.
The purpose of this paper is to present an algorithm developed for real-time estimation of skeletal muscle ischemia, based on parameters extracted from in vivo obtained electrical impedance spectra. A custom impedance spectrometer was used to acquire data sets: complex impedance spectra measured at 27 frequencies in the range of 100 Hz-1 MHz, and tissue pH. Twenty-nine in vivo animal studies on rabbit anterior tibialis muscle were performed to gather data on the behavior of tissue impedance during ischemia. An artificial neural network (ANN) was used to quantitatively describe the relationship between the parameters of complex tissue impedance spectra and tissue ischemia via pH. The ANN was trained on 1249, and tested on 946 ischemic tissue impedance data sets. A correlation of 94.5% and a standard deviation of 0.15 pH units was achieved between the ANN estimated pH and measured tissue pH values.  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