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991.
针对齿轮结构复杂、造型困难、使用频繁的特点,研究基于Pro/E平台的渐开线齿轮三维参数化造型技术;运用Pro/TOOLKIT、VC 对Pro/E软件进行二次开发,可根据用户输入的齿轮设计参数,自动生成齿轮的三维实体. 相似文献
992.
993.
Segmentation of volumetric data is an important part of many analysis pipelines, but frequently requires manual inspection and correction. While plenty of volume editing techniques exist, it remains cumbersome and errorprone for the user to find and select appropriate regions for editing. We propose an approach to improve volume editing by detecting potential segmentation defects while considering the underlying structure of the object of interest. Our method is based on a novel histogram dissimilarity measure between individual regions, derived from structural information extracted from the initial segmentation. Based on this information, our interactive system guides the user towards potential defects, provides integrated tools for their inspection, and automatically generates suggestions for their resolution. We demonstrate that our approach can reduce interaction effort and supports the user in a comprehensive investigation for high‐quality segmentations. 相似文献
994.
Nico Pietroni Davide Tonelli Enrico Puppo Maurizio Froli Roberto Scopigno Paolo Cignoni 《Computer Graphics Forum》2015,34(2):627-641
We introduce a framework for the generation of polygonal gridshell architectural structures, whose topology is designed in order to excel in static performances. We start from the analysis of stress on the input surface and we use the resulting tensor field to induce an anisotropic nonEuclidean metric over it. This metric is derived by studying the relation between the stress tensor over a continuous shell and the optimal shape of polygons in a corresponding gridshell. Polygonal meshes with uniform density and isotropic cells under this metric exhibit variable density and anisotropy in Euclidean space, thus achieving a better distribution of the strain energy over their elements. Meshes are further optimized taking into account symmetry and regularity of cells to improve aesthetics. We experiment with quad meshes and hexdominant meshes, demonstrating that our gridshells achieve better static performances than stateoftheart gridshells. 相似文献
995.
Kensei Hiwaki 《控制论与系统》2015,46(6-7):588-604
This article argues for a theoretical framework of alternative economics pertinent to Sustainable Development. The alternative economics requires an appropriate belief/value system based on a dynamic, sound and holistic society-specific culture (abbreviated as “Culture”). To represent the Culture-based belief/value system, a general framework for overarching Integral Harmony is introduced as an appropriate social value system for a paradigm shift toward sustainability. Such a social value system is now related to the value premises of the alternative economics. Then, the framework of alternative economics is explained in terms of basic theoretical construct that is simplified as a summary equation comprising value and real aspects. Finally, a typical working of the alternative economics is demonstrated diagrammatically as constant interactions of the value aspect and the real aspect (abbreviated as “Value-Real Interactions”). 相似文献
996.
《电子技术应用》2015,(12)
针对传统太阳能跟踪系统现场调试复杂、可靠性不够高的问题,提出一种基于STM32的太阳能跟踪系统设计。该系统为单轴跟踪系统,通过获取太阳能板的地理位置和当前时间信息用一定算法算出太阳的方位角,驱动电机,实现对太阳的跟踪;采用基于Zig Bee技术的无线通讯系统,具有群簇控制能力,简化现场调试过程;通过Mod Bus协议实现控制系统信息上报,便于后台管理;提供多种工作模式,提高系统的抗风、抗雪性能;通过在控制芯片片内Flash写入备份程序,保证系统主程序出现问题后,系统跳转至备份程序继续运行,提高系统的可靠性。在实际现场应用中,该系统具有系统运行稳定、升级维护方便、使用寿命长的特点。 相似文献
997.
This two‐group, pretest‐posttest, quasi‐experimental study compared secondary students' learning of Algebra II materials over a 4‐week period when identical instruction by the same teacher was delivered through either embedded blended learning (treatment group; n = 32) or a live‐lecture classroom (control group; n = 24). For both groups, instruction was delivered in a normal classroom setting. A math test and a student survey were used to measure students' learning of Algebra II and satisfaction with the instruction. Students in the treatment group showed significantly greater gains in Algebra II test scores and evaluated their learning experiences significantly more positively than did the control group. The great majority (80%) of students in the treatment group preferred the embedded blended learning over traditional live lectures for future learning of math. Students' responses to open‐ended survey questions suggested that students in the treatment group appreciated the: (a) ability to control the pace of instruction; (b) new role of the classroom teacher; (c) lack of distraction in the blended learning environment; and (d) accessibility of the embedded multimedia lessons outside the classroom. This study suggests that screen‐capture instructional technology can be used towards establishing a teacher‐based, embedded blended learning environment within a secondary algebraic classroom. 相似文献
998.
Heath education is an important component of the curriculum for fostering children's correct health knowledge and good daily life habits. However, educators have indicated that most children might fail to realize the importance and meaning of health education content owing to the lack of authentic scenarios and daily life experience. With the advancement of computer technologies, researchers have tried to develop multimedia learning content in order to improve students' learning performance. Among various technology-enhanced learning alternatives, digital game-based learning has been recognized as a highly potential approach to motivating students. However, several previous studies have indicated that, without properly incorporating learning content into game scenarios, the effectiveness of digital game-based learning might not be as good as expected in comparison with conventional technology-enhanced learning. In this study, a contextual digital game was developed for improving students' learning performance in an elementary school health education course. A quasi experiment was conducted to evaluate the effectiveness of the proposed approach by situating the experimental group in the game-based learning scenario and the control group to learn with conventional e-books. The experimental results showed that the proposed approach not only improved the students' learning motivation, but also their learning achievement and problem-solving competences. Moreover, the significant two-way interaction suggested that the contextual game-based learning approach benefited the higher motivation students more than the lower motivation ones in terms of the advanced knowledge, showing the importance and potential of applying contextual games to health education activities. 相似文献
999.
A collegial practice transfer process between more- and less-experienced teachers was examined in two cases that sought to encourage teachers to use information and communication technology (ICT) in a pedagogically meaningful way. Collegial practice transfer aims to offer new models for in-service teacher training. The process included guiding sessions, training materials presenting authentic pedagogical examples, and try-outs in the classroom. The success of practice transfer was examined through comparing the classroom practices of more- and less-experienced teachers applying the Pedagogical Infrastructure Framework, and through analyzing the tutored teachers' self-reported experiences in interviews. The process provided flexible support and gave self-confidence to the less-experienced teachers. Technology use was successful, but the tutored teachers designed less coherent tasks and weaker support for pupils' collaboration, knowledge construction and metacognition than their more-experienced colleagues. When tutoring, underlying educational ideologies and reasons should be explicated in addition to practical issues of classroom orchestration and technology use. 相似文献
1000.
Interactive high-performance computing is doubtlessly beneficial for many computational science and engineering applications whenever simulation results should be visually processed in real time, i.e. during the computation process. Nevertheless, interactive HPC entails a lot of new challenges that have to be solved – one of them addressing the fast and efficient data transfer between a simulation back end and visualisation front end, as several gigabytes of data per second are nothing unusual for a simulation running on some (hundred) thousand cores. Here, a new approach based on a sliding window technique is introduced that copes with any bandwidth limitations and allows users to study both large and small scale effects of the simulation results in an interactive fashion. 相似文献