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排序方式: 共有189条查询结果,搜索用时 15 毫秒
1.
Stig  Egnell  宗菁 《人类居住》2006,(1):15-16
瑞典国际发展合作署(SIDA)支持城市管理项目(UMP)有许多原因。瑞典国际发展合作署发现城市管理项目在减轻贫困、良好治理、环境、性别平等和艾滋病防治等问题上的主要观点、关注重点与其发展重点相近。  相似文献   
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Industry evaluation of the Requirements Abstraction Model   总被引:2,自引:1,他引:1  
Software requirements are often formulated on different levels and hence they are difficult to compare to each other. To address this issue, a model that allows for placing requirements on different levels has been developed. The model supports both abstraction and refinement of requirements, and hence requirements can both be compared with each other and to product strategies. Comparison between requirements will allow for prioritization of requirements, which in many cases is impossible if the requirements are described on different abstraction levels. Comparison to product strategies will enable early and systematic acceptance or dismissal of requirements, minimizing the risk for overloading. This paper presents an industrial evaluation of the model. It has been evaluated in two different companies, and the experiences and findings are presented. It is concluded that the requirements abstraction model provides helpful improvements to the industrial requirements engineering process.
Claes WohlinEmail:
  相似文献   
4.
This essay discusses the claims made by Hofstadter (1997) that machine translation research, as a result of its commercial aims, is based on a ‘pure content’ view of language, which is unrealistic even for specialized domains. The paper argues that this simplified view of language and translation cannot be blamed solely on industrial research; it is a tenet of basic research MT as well, and one that MT shares with much of AI. The question of whether there is a fundamental difference between narrow domain and general translation is discussed in the light of Melby's (1995) notion of a ‘wall’ between terms and general vocabulary.  相似文献   
5.
Since 2005, all fatal road traffic crashes in Norway have been analyzed in-depth by multidisciplinary investigation teams organized by the Norwegian Public Roads Administration (NPRA). During the period 2005–2010, 608 drivers of cars or vans were killed in road traffic crashes. Blood samples were collected from 372 (61%) of the drivers and analyzed for alcohol and a large number of psychoactive drugs at the Norwegian Institute of Public Health (NIPH). After coupling the analytical results with the NPRA crash database, 369 drivers with a fatal outcome were identified and included. Alcohol or drug concentrations in blood above the legal limits were found in 39.8% of the drivers who were investigated for alcohol or drug impairment; 33.9% had blood alcohol concentrations above 0.5 g/L or concentrations of drugs above the equivalent Norwegian legal impairment limits or concentrations of amphetamines above 200 μg/L. Among drivers with a fatal outcome who had been impaired by alcohol or drugs, 64.6% were unbelted and 71.7% were speeding when the crash occurred; whereas 24.2% and 33.2% of the sober drivers were unbelted or speeding, respectively. Statistically significant associations were found between impairment by alcohol or amphetamines and driving unbelted or speeding. Excessive speeding is one of the main reasons for road traffic crashes and together with being unbelted the main reasons for a fatal outcome. This behavior might in many cases be due to increased risk-taking or negligence of safety measures as a result of alcohol or drug use.  相似文献   
6.
The destabilization process was investigated for a Janus emulsion of silicone and Bixa Orellana oils stabilized by polyoxyethylene sorbitan monooleate (Tw 80) and carboxymethyl cellulose. The emulsion stabilized with Tw 80 showed significant and fast creaming, a process that was prevented by the addition of the polymer. During the extensive coalescence of the emulsions stabilized by Tw 80, the Janus topology was retained for months of storage until, finally, separation of the oils occurred. This result strongly indicates an unexpected stabilizing action of the i nterfacial free energy. This conclusion was supported by a calculation for a realistic model system of the interfacial energy difference between two cases of coalescence. In the first case, the two coalescing Janus drops united into a larger Janus drop, while in the second case two drops formed, each with only one oil. The first case gave a spontaneous reaction (reduced interfacial energy), while the second one meant an increase of energy, i.e. it cannot happen without adding energy. The authors are aware that this stabilization is a new phenomenon in emulsion science with potential ramifications in future emulsion technology. However, it is essential to realize that the stabilization is of temporary occurrence in the destabilization process, and the free energy to give a final emulsion state with separated oils is overwhelmingly dominant. In short, Janus emulsions will, in the end, separate into layers of the liquids, like all emulsions.  相似文献   
7.
We present an approach for modelling unsteady, primarily one-dimensional, compressible flow. The conservation laws for mass, energy, and momentum are applied to a staggered mesh of control volumes and loss mechanisms are included directly as extra terms. Heat transfer, flow friction, and multidimensional effects are calculated using empirical correlations. Transformations of the conservation equations into new variables, artificial dissipation for dissipating acoustic phenomena, and an asymmetric interpolation method for minimising numerical diffusion and non physical temperature oscillations are presented. The capabilities of the approach are illustrated with an example solution and an experimental validation of a Stirling engine model.  相似文献   
8.
Leaves of Brachystegia spiciformis represent a substantial fraction of the total aboveground litter in bush fallow fields with sandy soils in southern Mozambique, where annual rainfall exceeds 600 mm. This species is one of the most important in the miombo woodland that is the natural vegetation of the region. Proper knowledge of the decomposition of its litter is therefore crucial for understanding processes responsible for natural build-up of fertility in agricultural soils abandoned to bush fallow during shifting cultivation. This study investigated the effects of soil water content and soil temperature on loss of organic carbon (C) from decomposing leaves in litterbags with 1 mm mesh size. The litterbags were buried 50 mm deep in recently abandoned agricultural fields cleared of any vegetation (Bare) and in more than 15-year-old bush fallow fields (Fallow) of sites covering a climatic transect with annual rainfall from <400 mm to >1,000 mm. Two patterns of C loss were observed, one in coastal and wetter agroecosystems (rainfall >600 mm) and the other in inland and drier agroecosystems (rainfall <600 mm). In the wetter agroecosystems C loss was faster, whereas in drier agroecosystems it was more sensitive to rainfall pulses. Similarly, C loss was faster in fallow fields than in bare fields. During summer, bare fields reached soil temperatures higher than the estimated upper boundary favourable for C loss from decomposing leaf litter at all sites. A simple dynamic decomposition model describing the C fraction remaining in the litterbags was developed. Coefficients of determination (R 2) for the individual experimental units varied between 0.79 and 0.97. The general model for all sites and fields improved explanation of total variation from 81% to 86% when measured soil temperature and soil water content were used as modifiers of decomposition rate, compared with the standard negative exponential model. Root-mean-square error and systematic bias were 9.7% and 0.5% of initial C, respectively. Decomposition was more strongly affected by soil water content than by soil temperature and explained 75% of total variation. Thus, rainfall is the main driver of C loss from leaf litter in these agroecosystems.  相似文献   
9.
本介绍在欧洲和北美15家PCBA制造商的生产数据调查结果。数据末自X射线系统的自动检测结果和维修部门的附加信息。本报告可能是最完整的一份调查,因为它包括了来自不同制造商的566种各种电路板型号的,约329000块印制电路板和超过10亿个焊点的检测,以及焊接缺陷的分布资料。本首先描述数据收集处理的方法学,数据收集的时间,以及参与调查的公司综合介绍。统计结果表示分不同的公司、不同复杂程度的板、不同类型的公司和不同地理区域的缺陷水平。此外,还介绍了失效的分布图,并且对某些令人惊奇的结果作出了尽可能的解释。  相似文献   
10.
The evaporation path was determined for the emulsion system water, linalool and 5% Laureth 4, (L4), from the phase diagram of the components. The initial part of the evaporation took place in a two‐phase region of the emulsion and the path, expressed as fractions of the compounds, was non‐linear reflecting the changed vapour pressure of the linalool. The latter part of the evaporation, on the other hand, occurred through a three‐phase region and the path now formed a straight line. The recently introduced algebraic approach to extracting information from phase diagrams enabled presenting quantitative changes in composition, phase fractions and total content of the emulsion, as well as the vapour pressure versus different variables; including time.  相似文献   
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