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1.
The constructive analysis of Madrid's old timber-framed collective courtyard buildings, whether demolished, preserved intact, or enlarged, has achieved the dating of relevant case studies. New parameters established in this study set a chronology based on front sector original projects: old (1737–1788), pre-modern (1788–1847) and modern (1847–1892). The on-site inspection and archival research point to ongoing misleading construction in the historic Southern area. Some modern corralas erected on top of pre-existing buildings confirm the initial hypothesis. First dimensioning rules for new façades and the stability required in old ones before adding new storeys, maintaining the original masonry or double-layered system, are discovered. Undated buildings suggest their possible origin a la malicia and a later transformation into transitional corralas. Finally, an analysis of the demolished courtyards narrows down the dating and points to new conjectures in some preserved by showing their uneven layout, old features, and structural discordances in each sector.  相似文献   
2.
The ability of landscape architectural projects to mitigate the worst effects of climate change will depend upon designed ecological systems. These systems will be built with plants. Despite the recognition of ecology as an essential driver of landscapes, the professionals of landscape architecture too often lack the knowledge and practical skills to create robust vegetative systems. New approaches and tools are required. This article outlines principles and methods for designing biodiverse plant systems for urban sites. Planting methods that increase species richness, functional diversity, and spatial complexity are emphasized as a way of developing more resilient plantings. Selecting species with similar evolutionary adaptions to stress, disturbance, and competition—as well as creating multi-layered compositions of diverse plant morphologies—allows designers to create compatible, long-lived plant mixes. To balance the increased visual complexity of diverse plant mixes, the article explores design techniques to make plantings more appealing to the public. The strategies explored here are based on the projects, experience, and research of Phyto Studio, a Washington, D.C. based studio. The methods build on work described in the author’s book, Planting in a Post-Wild World, an exploration of how to create designed plant communities.  相似文献   
3.
This paper assesses building integrated photovoltaic (BIPV) installation parameters based on the profit generated by a photovoltaic system. It takes into consideration a home building case study and it investigates its monthly energy demand based on a specific location and a typical occupancy. The capability of a photovoltaic (PV) system to generate more profit occurs when solar intensity is maximum while the electric energy price is at its highest rate. The paper traces a framework that encompasses different aspects such as energy demand, energy price, and solar intensity. This framework identifies profit alternatives according to different installation parameters. A tool that predicts a PV installation hourly electric energy production is developed. The profit generated is simulated for home buildings located in Beirut (Lebanon) and Xihua (China), both at 33.8° latitude north. The paper highlights a new approach for BIPV installations, taking into account weather conditions, energy demand, and electric energy utility rates.  相似文献   
4.
While creativity is essential for developing students’ broad expertise in Science, Technology, Engineering, and Math (STEM) fields, many students struggle with various aspects of being creative. Digital technologies have the unique opportunity to support the creative process by (1) recognizing elements of students’ creativity, such as when creativity is lacking (modeling step), and (2) providing tailored scaffolding based on that information (intervention step). However, to date little work exists on either of these aspects. Here, we focus on the modeling step. Specifically, we explore the utility of various sensing devices, including an eye tracker, a skin conductance bracelet, and an EEG sensor, for modeling creativity during an educational activity, namely geometry proof generation. We found reliable differences in sensor features characterizing low vs. high creativity students. We then applied machine learning to build classifiers that achieved good accuracy in distinguishing these two student groups, providing evidence that sensor features are valuable for modeling creativity.  相似文献   
5.
Control of self-assembling systems at the micro- and nano-scale provides new opportunities for the engineering of novel materials in a bottom-up fashion. These systems have several challenges associated with control including high-dimensional and stochastic nonlinear dynamics, limited sensors for real-time measurements, limited actuation for control, and kinetic trapping of the system in undesirable configurations. Three main strategies for addressing these challenges are described, which include particle design (active self-assembly), open-loop control, and closed-loop (feedback) control. The strategies are illustrated using a variety of examples such as the design of patchy and Janus particles, the toggling of magnetic fields to induce the crystallization of paramagnetic colloids, and high-throughput crystallization of organic compounds in nanoliter droplets. An outlook of the future research directions and the necessary technological advancements for control of micro- and nano-scale self-assembly is provided.  相似文献   
6.
为了提供高性能和柔性,操作系统内核应该只保留最小的功能,今天的操作系统大而低效,更缺乏柔性,我们提出了保护分散式操作系统抽象方法,集成了分散式操作系统抽象和保护抽象的方法,这种新的安全方式在分散式抽象系统里共享用户级的抽象,能够使非特权,不信任的任务在运行时定义并安全的共享生成的抽象,它在对相同的抽象重复调用时,通过消除上下文切换的需求和对通常情况进行优化,可获得较好的柔性,保护分散式抽象的设计强调简单并正确性证明,易于理解和使用,文章介绍了保护分散式操作系统抽象方法,并运用该方法开发了一个基于共享库的原型操作系统-ExLinux/LibOS.  相似文献   
7.
环境中氚和碳-14   总被引:4,自引:0,他引:4  
方栋  李红 《辐射防护》2002,22(1):51-56
本文介绍了加拿大恰克河实验室有关氚和碳-14在环境中行为和评价的研究。  相似文献   
8.
Based on an idea introduced by Benjamin and Cornell (1970. Probability, statistics and decision for civil engineers. New York: McGaw Hill) and previous works by the authors it is demonstrated how condition indicators may be formulated for the general purpose of quality control and for assessment and inspection planning in particular. The formulation facilitates quality control based on sampling of indirect information about the condition of the considered components. This allows for a Bayesian formulation of the indicators whereby the experience and expertise of the inspection personnel may be fully utilized and consistently updated as frequentistic information is collected. The approach is illustrated on an example considering a concrete structure subject to corrosion. It is shown how half-cell potential measurements may be utilized to update the probability of excessive repair after 50 years. Furthermore in the same example it is shown how the concept of condition indicators might be applied to develop a cost optimal maintenance strategy composed of preventive and corrective repair measures.  相似文献   
9.
This article traces the connection between expert systems used as consultants in medicine and their design for instructional purposes in education. It is suggested that there are important differences between these applications. Recognizing these differences leads to the view that the development of intelligent computer-assisted instructions (ICAI) should be guided by empirical research into social/psychological consequences and by ethical inquiries into the acceptability of those consequences. Three proposals are put forward: (1) that the pedagogical role of intelligent CAI be clarified, (2) that forms of intelligent CAI be developed that aim primarily at refining rather than replacing human judgements, and (3) that ICAI research and development projects contain components which address ethical and social/psychological components and which are equitably-funded, integral parts of the overall development effort.This work was supported in part by funds from the Foundation of the University of North Carolina at Charlotte and from the State of North Carolina. An earlier version of this paper was read at the Human Dimension in Artificial Intelligence Symposium held at the University of Kentucky (April 1988).  相似文献   
10.
The worldwide proliferation of fraudulent materials has brought about the need for a new approach to the control of purchased material quality. Nuclear power, defense, aerospace and many other industries are affected by the supply of poor quality clones that presume to be original replacement parts. Safety considerations abound as these highly defective materials are used in systems that are critical to the preservation of human lives. Commonly utilized quality assurance programs have not effectively stopped the influx of fraudulent materials. These programs fail to concentrate inspection efforts on materials and inspection attributes that would effectively prevent the acceptance of fraudulent materials. herein a solution is presented to this problem in the form of an expert system application. Information commonly available in industry is formulated into a knowledge based system wherein advisories are given to the user regarding key purchased material receipt inspection strategies.  相似文献   
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