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   16篇
  免费   0篇
化学工业   3篇
机械仪表   1篇
建筑科学   2篇
能源动力   4篇
轻工业   1篇
一般工业技术   2篇
自动化技术   3篇
  2022年   1篇
  2017年   1篇
  2015年   4篇
  2012年   2篇
  2010年   1篇
  2005年   1篇
  2003年   1篇
  2000年   1篇
  1987年   3篇
  1973年   1篇
排序方式: 共有16条查询结果,搜索用时 0 毫秒
1.
    
Resistivity and thermoelectric-power data for the tetragonal compounds Ln2NiO4 and Ln2CuO4 are interpreted qualitatively in terms of narrow energy bands of strongly correlated d-like electrons.  相似文献   
2.
    
《Geothermics》1987,16(4):375-392
A test site for HDR experiments has been set up in granite in the Bohemian massif in east Bavaria. A large fracture was stimulated by hydraulic fracturing in a depth of 250 m. The orientation of the fracture was investigated by seismo-acoustic recording during the frac-experiments and by examining the fracture pattern initiated in the injection interval of the borehole by an impression packer and by acoustic televiewer measurements. Geoelectric measurements for fracture location at the surface were also tested before attempting to drill through the fracture. The fracture has now been intersected by 6 additional boreholes at distances between 2 m and 70 m from the initiation interval.According to the results of seismo-acoustic recording, temperature logging and acoustic televiewer measurements in the intersection boreholes, a single plane artificial fracture has been produced, striking E-W and dipping 50°S. The orientation of the fracture, which should be normal to the least compressive principal stress, and the value of the normal stress on the fracture are not consistent with the direction and the values of the principal stresses determined by wire line hydraulic fracturing stress measurements.Various hydraulic experiments were performed in the different boreholes to investigate the mechanical reaction of the fracture due to varying fluid pressure, the hydraulic properties of the fracture, the fluid losses and the heat exchange within the fracture. The models developed to interpret the results make it possible to translate the results to greater depth and higher flow rates.  相似文献   
3.
    
《Fuel》1987,66(6):771-773
  相似文献   
4.
    
The present investigation provides a micro-mechanical model for the splitting failure analysis of fiber reinforced plastic (FRP) reinforced concrete members subjected to longitudinal tensile stresses. The model consists of three co-axial cylinders: (a) the inner elastic FRP rod; (b) the mid cracked part of concrete; and (c) the outer elastic part of concrete. The anisotropic properties of reinforcement, the compatibility of longitudinal strain at interface and the effect of Poisson's ratio of concrete are taken into account in the analysis. The method can be used to predict the stress distributions in the hybrid structure and the relations between the growth of cracks and the applied end forces. It is found that the number of splitting cracks and the material properties of the anisotropic FRP rods are not the dominant factors in splitting failure. It is also observed that neglecting Poisson's ratio of cracked concrete may under-estimate stresses in the hybrid structure.  相似文献   
5.
    
Experience with geothermal development for electricity production has shown that use is not sustainable if heat from the reservoir is extracted too rapidly. Examples of unsustainable development are given. Policy aimed at achieving sustainable development at the very least should encompass conditions governing access to reservoirs, the rate at which thermal energy is extracted, monitoring, and re-injection of fluids. An economic model illustrates the application of fiscal instruments to geothermal development for electricity generation. Ad valorem royalties are shown to encourage utilisation of the resource in a more sustainable manner. A variable ad valorem royalty, based on the ratio of the current and original temperature shows a significant change in investment planning, with slower depletion, compared to the application of a non-variable ad valorem royalty.  相似文献   
6.
Russian renewable energy policy has undergone changes following an establishment of targets for installed capacity and power production using renewable energy sources and the introduction of new capacity based support scheme for renewable energy. The forecasted amount of future renewable power will not provide enough power production to meet growing demand for renewable energy; although, it will help with modernization of the energy sector and development of renewable technology and innovation. At the same time, the capacity support scheme for renewable energy may adversely affect capacity prices and become an additional burden for industrial consumers, who are already paying the cost of capacity support for conventional power plants, so-called Capacity Delivery Agreements (CDAs). This work assesses the impact of the new capacity based support scheme on capacity and electricity price formation. Modeling results show that the impact of capacity support for renewable energy is small compared to that of capacity support for conventional energy, suggesting that the Russian energy production mix will continue to be dominated by fossil fuel based generation.  相似文献   
7.
《Journal of food engineering》2003,56(2-3):163-169
Human evolution is accompanied by innovations in food processing. The results are remarkable: there is food security, as there is surplus on cheap, safe and high quality food. Despite this situation nutritional studies reveal that there are still nutritional problems in the world. Food security is only a precondition but no guarantee for nutrition security.The causes of nutritional problems are complex. In industrialised societies the importance of the last links of the food chain, being the competence of consumers regarding food and nutrition, is ignored. Whereas the global knowledge on food processing is increasing continuously, a reverse trend regarding consumer competence can be observed. The consequences of these trends have to be observed and studied. People with less food and nutrition competence are susceptible to disorientation and misguided behaviour. It is likely that the trend accelerates since the traditional ways to learn food and nutrition competence are diminishing; even in the case of food professionals, like cooks or bakers, there is clear evidence of lack of practical experiences.Nutrition and food policy has to focus on this gap. The most important nutritional problems are no longer those of food quality, but related to consumer behaviour. Today’s consumers need high qualification to use all the opportunities to manage the everyday tasks. Without fostering such training (not only for the general population, but also for food professionals) we in Europe are in danger of becoming a food illiterate population.  相似文献   
8.
    
System VVT (verification, validation, and testing) are three tasks of System Engineering that focus on ensuring that systems are designed and delivered to meet customer and engineering requirements in the best way possible. Most organizations use sub-optimal VVT processes and methods. The literature does not offer an effective approach for associating VVT methods to VVT activities in order to satisfy customer and engineering requirements. In many large and complex projects, the project manager faces the dilemma of how best to validate and verify customer and engineering requirements, respectively. In many cases, decisions are made in an intuitive manner. For a project with a small amount of requirements (e.g., design of a new chair, table, or a simple toy), optimum decisions for VVT methods to be included within the project are feasible. For projects with large amount of requirements, for example, design of a new payload (e.g., captive carriage of a fuel tank, camera pod or other equipment) on an aircraft, a structured process to evaluate the overall impact of VVT methods implemented in order to satisfy those requirements, and the risk involved by performing these and not other methods, is necessary. This paper proposes a model for selecting an appropriate VVT approach depending on the phase or the level of the product in the system hierarchy; the model is independent of project size or precedence. We present an analytical model that not only structures the decision process but also outputs the optimal VVT methods given Cost and Risk constraints. The analytical model was formulated as an optimization problem, where a function that associates Quality derived from incorporating VVT methods is maximized subject to Cost and/or Risk constraints. The use of the model is demonstrated on a sample problem.  相似文献   
9.
    
This paper proposes a method to control muscular flexibility during training and rehabilitation. This method invokes muscular stretching by mechanical stimulation of the neuromuscular gamma loop. The specification and characterization of this method are based on a simulation model related to the biomechanical behaviour of muscle. This model was used to identify the parameters required for the implementation of mechanical stimulation on an isokinetic machine. A generic control architecture for this type of machine was proposed to carry out stimulation patterns that invoke muscular stretching. As validation, experimental data were obtained with the help of Multi-Iso, a machine used for training and rehabilitation of the lower limbs.  相似文献   
10.
We present an experimental study of relations between hydraulic properties of clayey rocks and their deformation at bulk and micro scale. The experimentation is based on triaxial deformation of kaolinitic core samples, on permeability measurements, and on several methods of analysis of the microstructure. To produce the samples, remoulded kaolinite material is consolidated by axial loading up to 20 MPa in an oedometric cell. Then, in a triaxial cell, an undrained stress path is applied in order to induce shearing damage in the sample. The permeability of the sample is measured by fluid flow across the sample. Before and after these hydro-mechanical tests, the evolution and the homogeneity of the pore space and moreover the texture of the material are analysed by X-ray tomography, environmental scanning electron microscopy and thermic neutron diffraction. Contrary to expectations, the permeability at the sample scale does not vary significantly, although quite large deformation is reached. The final deformation is heterogeneous, with well-developed shear bands. It appears that the development of compacting and dilating zones generates a heterogeneous permeability field, which results in a negligible variation of the bulk permeability at the sample scale.  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