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991.
Tino Kühn Daniel Schmitt Oliver Millon Thomas Hntzschel Alexander Stolz Manfred Curbach Klaus Thoma 《Bautechnik》2016,93(10):717-724
Metrological challenges analyzing high dynamic impact on reinforced slabs The comprehension of high dynamic impact processes on reinforced concrete structures is of essential importance for the dimensioning of structures regarding exceptional loading scenarios like airplane impacts. Since, for high strain rates in comparison with quasi‐static conditions an altered material behavior appears, an adequate methodology and application of appropriate measurement is required to assess the structural behavior of building components. The present paper describes the metrological methodology and the challenges of the experimental investigations of reinforced concrete slabs under impact with loading periods of only a few μs or ms. The determination of time history curves of impact velocities, bearing forces, displacements and the determination of sound wave velocities inside the structure requires an appropriate high sampling rate with the signal recording. The results lately lead to a holistic assessment of the structural behavior and the damage phenomena of such processes. 相似文献
992.
Jeldrik Mainka Harald Kloft Sarah Baron Hans‐Werner Hoffmeister Klaus Drder 《Beton- und Stahlbetonbau》2016,111(12):784-793
Non‐Waste wax formwork‐technology Today's possibilities to realize complex free‐form reinforced concrete shapes, curved walls and filigree details require a formwork technology which meets these challenges. High precision with maximum freedom of form is therefore an essential requirement for the formwork of this new, so‐called freeform architectures. Preconditions for this are the 3D digital design and manufacturing technologies, with their help formwork can be designed and manufactured in high precision and with many degrees of freedom in form. This paper describes a research approach using industrial waxes as formwork materials. Due to the nearly 100 % recyclability of the wax, this approach is an economical and ecological manufacturing process for customized free‐form‐members made of concrete. 相似文献
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Microbiological investigations for sanitary assessment of wastewater treated in constructed wetlands 总被引:3,自引:0,他引:3
Microbiological investigations into the occurrence and fate of pathogens in wastewater were carried out in a multi-annual measurement programme, using samples from three artificial wetlands equipped with pre-treatment systems (multi-chamber septic tanks, lagoons) and predominantly treating domestic wastewater. In this study, the concentrations of indicator organisms and pathogenic or potentially pathogenic microorganisms were determined in the various components or stages of the systems. The evaluation of data from some 3.600 microbiological analyses and a comparison with older data from a plant which has already been operation for 18 y made it possible for the first time ever to include operational factors in the assessment. Average removal of all major indicator organisms and pathogens is 1.5-2.5 log units for one-stage systems and increases to 3-5 log units for multi-stage systems. Significant differences between horizontal and vertical filters were not found. If no clogging problems arise during their operation, multi-stage systems can meet the requirements of the EU bathing water and irrigation water directives. Influent concentration, wastewater temperature, and hydraulic loading rate were found to be major factors of influence. The performance of constructed wetlands in removing microorganisms is clearly superior to that of conventional biological activated sludge systems. 相似文献
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Enns AA Vogel LJ Abdelzaher AM Solo-Gabriele HM Plano LR Gidley ML Phillips MC Klaus JS Piggot AM Feng Z Reniers AJ Haus BK Elmir SM Zhang Y Jimenez NH Abdel-Mottaleb N Schoor ME Brown A Khan SQ Dameron AS Salazar NC Fleming LE 《Water research》2012,46(7):2237-2246
Fecal indicator microbes, such as enterococci, are often used to assess potential health risks caused by pathogens at recreational beaches. Microbe levels often vary based on collection time and sampling location. The primary goal of this study was to assess how spatial and temporal variations in sample collection, which are driven by environmental parameters, impact enterococci measurements and beach management decisions. A secondary goal was to assess whether enterococci levels can be predictive of the presence of Staphylococcus aureus, a skin pathogen. Over a ten-day period, hydrometeorologic data, hydrodynamic data, bather densities, enterococci levels, and S. aureus levels including methicillin-resistant S. aureus (MRSA) were measured in both water and sand. Samples were collected hourly for both water and sediment at knee-depth, and every 6 h for water at waist-depth, supratidal sand, intertidal sand, and waterline sand. Results showed that solar radiation, tides, and rainfall events were major environmental factors that impacted enterococci levels. S. aureus levels were associated with bathing load, but did not correlate with enterococci levels or any other measured parameters. The results imply that frequencies of advisories depend heavily upon sample collection policies due to spatial and temporal variation of enterococci levels in response to environmental parameters. Thus, sampling at different times of the day and at different depths can significantly impact beach management decisions. Additionally, the lack of correlation between S. aureus and enterococci suggests that use of fecal indicators may not accurately assess risk for some pathogens. 相似文献
999.
在过去十几年里,没有一个概念能够像“创意城市”那样对欧洲的学术论著、城市政策和战略思考等产生如此强烈的影响.很多人认为创意城市理念已经成长为城市发展的一种新范式;但在另一部分人眼里,它不过是一种不可持续的、创造性的概念热潮而已,一旦人们发现创意城市实际能带来的现实效应非常有限,它的政治吸引力就会逐渐消失.事实上,尽管创意城市的概念非常模糊和笼统,但在全球化和城市竞争日益加剧的特殊时代背景下,它仍然激励着无数规划师、政策决策者和城市开发管理人员,想方设法地通过“创意”来推进文化、经济和城市的全面发展: 相似文献
1000.
This article explores the challenges, advantages and limitations of the pro-active use of the social construction of technology (SCOT) to improve the methods applied in the development of technology for use by a broad range of actors. Our example is the development of environmental indicators for buildings (EIFOBs). We compare the pro-active use of SCOT with both the ‘traditional’ use of SCOT and with the ‘traditional’ way of developing EIFOBs. pro-actively applying SCOT in developing EIFOBs has the potential of bridging some of the communication gaps at the boundaries between the various professional groups in a multi-actor decision-making process. Using SCOT in a pro-active way means the research becomes action research and the researcher goes beyond the role of a mere observer and becomes an actor too. This means the researcher has to consider the criteria for valid action research when designing and carrying out the research. 相似文献