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21.
Loss statistics for natural disasters demonstrate, also after correction for inflation, a dramatic increase of the loss burden since 1950. This increase is driven by a concentration of population and values in urban areas, the development of highly exposed coastal and valley regions, the complexity of modern societies and technologies and probably, also by the beginning consequences of global warming. This process will continue unless remedial action will be taken. Managing the risk from natural disasters starts with identification of the hazards. The next step is the evaluation of the risk, where risk is a function of hazard, exposed values or human lives and the vulnerability of the exposed objects. Probabilistic computer models have been developed for the proper assessment of risks since the late 1980s. The final steps are controlling and financing future losses. Natural disaster insurance plays a key role in this context, but also private parties and governments have to share a part of the risk. A main responsibility of governments is to formulate regulations for building construction and land use. The insurance sector and the state have to act together in order to create incentives for building and business owners to take loss prevention measures. A further challenge for the insurance sector is to transfer a portion of the risk to the capital markets, and to serve better the needs of the poor. Catastrophe bonds and microinsurance are the answer to such challenges. The mechanisms described above have been developed to cope with well-known disasters like earthquakes, windstorms and floods. They can be applied, in principle, also to less well investigated and less frequent extreme disasters: submarine slides, great volcanic eruptions, meteorite impacts and tsunamis which may arise from all these hazards. But there is an urgent need to improve the state of knowledge on these more exotic hazards in order to reduce the high uncertainty in actual risk evaluation to an acceptable level. Due to the rarity of such extreme events, specific risk prevention measures are hardly justified with exception of attempts to divert earth-orbit crossing meteorites from their dangerous path. For the industry it is particularly important to achieve full transparency as regards covered and non-covered risks and to define in a systematic manner the limits of insurability for super-disasters.  相似文献   
22.
The thermally developing turbulent lead bismuth (Pb45Bi55) flow within a vertical annulus with the inner surface uniformly heated is experimentally investigated. The ratio between internal and external diameter is 0.136. The investigated Reynolds numbers vary between 1.48 × 104 and 2.37 × 105 and the applied heat flux from 135 kW/m2 to 905 kW/m2, covering both the forced and mixed convection regime. For forced convection, the local heat transfer convective coefficient is evaluated and compared with literature correlations for low Prandtl number fluids. Additionally, a new empirical relation for the local Nusselt number in the thermal entry region is proposed. The applicability of criteria addressing the forced to mixed convection transition in medium to high Prandtl number fluids is reviewed and extended to account also for low Prandtl number fluids such as heavy liquid metals. Here, the transition from turbulent-diffusion to molecular-diffusion dominated mixed convection is clearly shown.  相似文献   
23.
No work is inherently either visible or invisible. We always see work through a selection of indicators: straining muscles, finished artifacts, a changed state of affairs. The indicators change with context, and that context becomes a negotiation about the relationship between visible and invisible work. With shifts in industrial practice these negotiations require longer chains of inference and representation, and may become solely abstract.This article provides a framework for analyzing invisible work in CSCW systems. We sample across a variety of kinds of work to enrich the understanding of how invisibility and visibility operate. Processes examined include creating a non-person in domestic work; disembedding background work; and going backstage. Understanding these processes may inform the design of CSCW systems and the development of related social theory.  相似文献   
24.
Definition of the problem: Under certain conditions terminal sedation can be considered ethically justifiable. Arguments and conclusion: As humans are aware of the limitations of their lives, the process of dying can be understood as a part of life which is consciously shaped and subject to one’s own will. This also includes the paradox to forego a conscious death. The desire of a terminally ill patient for euthanasia can be interpreted as the consequence of a life that has been fully integrated into the health-care system. Patients comprehend dying as a task of the medical system, and medically-assisted suicide as an expression of human dying, paradoxically even as a natural death. In this complex situation, terminal sedation represents progress as the medical system can play its anticipated role and fulfil its responsibility in the death process without directly or intentionally killing. Nevertheless, doubts remain concerning possible abuse, the physician’s role, and the limitations of human actions. “The illusion of easy solutions” (H. Thielicke) should be avoided and attempts made to seek the best solution for each individual.  相似文献   
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Films, either organic or inorganic in nature, can form at electrode surfaces by naturally occurring processes or can be deliberately induced to form there. The behaviour of a deliberately formed Ca(OH)2 film on the rate of cathodic hypochlorite reduction in an undivided brine electrolysis cell is examined. The results can be modelled in terms of electrode obscuration and the conditions for film formation and dissolution are also treated. It is shown that the latter is a self-limiting process.  相似文献   
27.
Based on the test information available in the literature since 1990, a comprehensive database is assembled for an extensive survey of existing studies on the flexural behavior of reinforced concrete beams externally strengthened with fiber-reinforced polymer (FRP) composites. Beam dimensions, material properties (concrete, steel reinforcement, FRP composites, etc.), and corresponding flexural responses such as failure modes, moment capacities, and so on, are collected in this database. The purpose of this database is to verify the design formulas presented in ACI 440.2R-02, Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures. The performance of some other simple strength design models is investigated based on the same database and compared with that of the ACI model, which is found to have the least scattered prediction compared to others. Finally, a modified maximum strain FRP equation is recommended.  相似文献   
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29.
Systemic lupus erythematosus (SLE) is an autoimmune disease that affects approximately 1–45.3 per 100,000 people worldwide. Although deaths as a result of active and renal diseases have been substantially declining amongst SLE patients, disease involving the central nervous system (CNS), collectively termed neuropsychiatric systemic lupus erythematosus (NPSLE), remains one of the important causes of death in these patients. Cognitive dysfunction is one of the most common manifestations of NPSLE, which comprises deficits in information-processing speed, attention and executive function, in conjunction with preservation of speech. Albeit a prevalent manifestation of NPSLE, the pathogenetic mechanisms of cognitive dysfunction remain unclear. Recent advances in genetic studies, molecular techniques, neuropathology, neuroimaging and cognitive science have gleaned valuable insights into the pathophysiology of lupus-related cognitive dysfunction. In recent years, a role for autoantibodies, molecular and cellular mechanisms in cognitive dysfunction, has been emerging, challenging our previous concept of the brain as an immune privileged site. This review will focus on the potential pathogenic factors involved in NPSLE, including anti-N-methyl-d-aspartate receptor subunit NR2A/B (anti-NR2A/B) antibodies, matrix metalloproteinase-9, neutrophil extracellular traps and pro-inflammatory mediators. Better understanding of these mechanistic processes will enhance identification of new therapeutic modalities to halt the progression of cognitive decline in SLE patients.  相似文献   
30.
The stable isotope technique and the difference method are common approaches for estimating fertiliser N uptake efficiency. Both methods, however, have limitations and their suitability may depend on N management and environmental conditions. A field experiment was conducted on a humus sandy soil in northern Germany to estimate fertiliser N uptake efficiency of silage maize in the year of application (Zea mays L.) by the stable isotope and the difference method as influenced by the type of N fertiliser (mineral vs. cattle slurry), the application mode (separate or combined application), and N rate. Seven N treatments were included (0, 50, 100 and 150 kg mineral N ha−1; 20, 40 m3 cattle slurry ha−1; 50 kg mineral N ha−1 plus 40 m3 slurry ha−1), where either mineral N or slurry N was labelled, and mineral N was split into two dressings. In addition, 4.1 kg ha−1 labelled mineral N was incorporated into otherwise unlabelled treatments (0, 20, 40 m3 ha−1, and 50 kg mineral N ha−1 plus 40 m3 ha−1) to estimate N uptake from the upper soil layer. Uptake of 15N was followed in leaves, stalk, ear, and the whole crop. Fertiliser N uptake efficiency (FNUE15N) of mineral fertiliser N obtained by the isotope technique ranged between 51 and 61%. Recovered fertiliser N was mainly found in the ear, while less labelled N remained in leaves and the stalk. The nitrogen rate tended to increase the amount of recovered N, but the effect was not consistent among plant parts and the whole crop. Plant N uptake from non-fertiliser N was found to increase N input up to 100 kg N ha−1. Nitrogen recoveries of the two mineral N dressings were similar for the different plant parts as well as for the whole crop. Fertiliser N uptake efficiency (FNUEdiff) of mineral N estimated by the difference method resulted in substantially higher values compared to FNUE15N, varying between 56 and 98%. More N was taken up from the upper soil layer with increasing N supply, which is regarded as a major error source of the difference method. Slurry N was taken up less efficient in the year of application than mineral fertiliser N as indicated by recovery rates of 21–22% (FNUE15N) and 39–62% (FNUEdiff), respectively. When mineral N and slurry were applied together, the difference method estimated significantly lower N uptake efficiencies for both mineral and slurry N compared to a single application, while values obtained by the isotope method were not affected.  相似文献   
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