全文获取类型
收费全文 | 3772篇 |
免费 | 288篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 76篇 |
综合类 | 19篇 |
化学工业 | 987篇 |
金属工艺 | 81篇 |
机械仪表 | 64篇 |
建筑科学 | 310篇 |
矿业工程 | 18篇 |
能源动力 | 104篇 |
轻工业 | 263篇 |
水利工程 | 27篇 |
石油天然气 | 2篇 |
无线电 | 321篇 |
一般工业技术 | 801篇 |
冶金工业 | 233篇 |
原子能技术 | 14篇 |
自动化技术 | 744篇 |
出版年
2024年 | 6篇 |
2023年 | 58篇 |
2022年 | 133篇 |
2021年 | 148篇 |
2020年 | 117篇 |
2019年 | 98篇 |
2018年 | 128篇 |
2017年 | 108篇 |
2016年 | 160篇 |
2015年 | 165篇 |
2014年 | 190篇 |
2013年 | 266篇 |
2012年 | 256篇 |
2011年 | 314篇 |
2010年 | 261篇 |
2009年 | 210篇 |
2008年 | 211篇 |
2007年 | 208篇 |
2006年 | 158篇 |
2005年 | 149篇 |
2004年 | 100篇 |
2003年 | 87篇 |
2002年 | 80篇 |
2001年 | 51篇 |
2000年 | 44篇 |
1999年 | 53篇 |
1998年 | 47篇 |
1997年 | 33篇 |
1996年 | 46篇 |
1995年 | 30篇 |
1994年 | 17篇 |
1993年 | 18篇 |
1992年 | 11篇 |
1991年 | 11篇 |
1990年 | 10篇 |
1989年 | 13篇 |
1988年 | 5篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1979年 | 8篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 5篇 |
1970年 | 3篇 |
1969年 | 2篇 |
排序方式: 共有4064条查询结果,搜索用时 22 毫秒
41.
Enterprise architecture is a model-based IT and business management discipline. Enterprise architecture analysis concerns using enterprise architecture models for analysis of selected properties to provide decision support. This paper presents a framework based on the ArchiMate metamodel for the assessment of four properties, viz., application usage, system availability, service response time and data accuracy. The framework integrates four existing metamodels into one and implements these in a tool for enterprise architecture analysis. The paper presents the overall metamodel and four viewpoints, one for each property. The underlying theory and formalization of the four viewpoints is presented. In addition to the tool implementation, a running example as well as guidelines for usage makes the viewpoints easily applicable. 相似文献
42.
43.
Christoph Windmeier Felix Flegiel Alexander Döß Ronald Franz Eckhard Schleicher Michael Wiezorek Markus Schubert Uwe Hampel 《化学,工程师,技术》2021,93(7):1119-1125
An optimized equipment design for natural gas processing and liquefaction plants becomes increasingly difficult with changing process conditions: Particularly low values of surface tension create rising challenges on the design of phase separators and column internals. The TERESA test rig at HZDR was designed to allow the investigation of multiphase thermohydraulics and phase separator performance under critical fluid properties in industrial dimensions. A versatile pipe test section is available in DN200 and equipment internals may be tested in a sectional DN300/DN500 test separator. The applied test fluid shows a high vapor-liquid density difference between 1470 and 940 kg m−3, viscosity as low as 0.12 mm2s−1, and surface tension down to 1.3 mN m−1. Volumetric liquid and vapor flow rates may be varied up to 9 and 530 m3h−1 in the test rig, respectively. 相似文献
44.
Chethan Savandaiah Julia Maurer Markus Gall Andreas Haider Georg Steinbichler Janak Sapkota 《应用聚合物科学杂志》2021,138(16):50243
For the 3D printed composites, fiber alignment is affected by the direction of melt-flow during extrusion of filaments and subsequently through the printing nozzle. The resulting fibers orientation and the fiber-matrix compatibility have a direct correlation with mechanical properties. This study investigates the impact of processing conditions on the state of the carbon fiber types and their orientation on the mechanical properties of 3D-printed composites. Short and long carbon fibers were used as starting reinforcing materials, and the state of fibers at the beginning and on the printed parts were evaluated. Strong anisotropy in terms of mechanical properties (flexural and impact properties) was observed for the samples printed with different printing orientations. Interestingly, the number of voids in the printed composites was found to be correlated with the fiber types. The present work provides a step towards the optimization of tailored composite properties by additive manufacturing. 相似文献
45.
Nataraj Nandita Adam Elisabeth Hansson Bill S. Knaden Markus 《Journal of chemical ecology》2021,47(12):1042-1048
Journal of Chemical Ecology - Many pollinating insects exhibit flower constancy, i.e. they target flower species they have already experienced and fed from. While the insects might profit from... 相似文献
46.
This survey gives an overview of the current state of the art in GPU techniques for interactive large‐scale volume visualization. Modern techniques in this field have brought about a sea change in how interactive visualization and analysis of giga‐, tera‐ and petabytes of volume data can be enabled on GPUs. In addition to combining the parallel processing power of GPUs with out‐of‐core methods and data streaming, a major enabler for interactivity is making both the computational and the visualization effort proportional to the amount and resolution of data that is actually visible on screen, i.e. ‘output‐sensitive’ algorithms and system designs. This leads to recent output‐sensitive approaches that are ‘ray‐guided’, ‘visualization‐driven’ or ‘display‐aware’. In this survey, we focus on these characteristics and propose a new categorization of GPU‐based large‐scale volume visualization techniques based on the notions of actual output‐resolution visibility and the current working set of volume bricks—the current subset of data that is minimally required to produce an output image of the desired display resolution. Furthermore, we discuss the differences and similarities of different rendering and data traversal strategies in volume rendering by putting them into a common context—the notion of address translation. For our purposes here, we view parallel (distributed) visualization using clusters as an orthogonal set of techniques that we do not discuss in detail but that can be used in conjunction with what we present in this survey. 相似文献
47.
Hagen Seifert Nicola Ranieri Quinn Smithwick Markus Gross 《Journal of the Society for Information Display》2016,24(9):552-562
We propose two methods to increase the pixel and spatial resolution of Digital Micromirror Devices (DMD)‐based projectors by utilizing the large bandwidth provided by their high pattern rates. By varying the intensity of the illumination for each binary pattern displayed on the DMD, the time required to display an 8‐bit grayscale image can be reduced by up to factor 32 compared to using constant illumination and binary pulse‐width modulation (BPWM). The high image rate projection is then spatially separated by either using a galvanometer scanner or sequentially illuminating the DMD from different directions, thus creating multiple independently addressable projections which are then tiled to form a larger, higher resolution image. 相似文献
48.
49.
Markus Kostrzewa Katrin Sparbier Thomas Maier Sören Schubert 《Proteomics. Clinical applications》2013,7(11-12):767-778
MALDI-TOF MS profiling for microorganism detection has already been demonstrated in the 1990s, but has evolved to the first-line identification method in many laboratories just during the past five years. While this application of MALDI-TOF MS has proven its broad applicability, accuracy, robustness, and cost-effectiveness it is of particular interest to expand the capabilities of the mass spectrometric platform. Resistance detection is the most desirable further application of MALDI-TOF MS in microbiology, but maybe also the most challenging. Different approaches have been published regarding diverse antibiotic drugs and distinct microorganism classes. The current review shall give an overview about the developments of the recent years and their potential to get transformed in clinical useful assays in the future. 相似文献
50.
Olaf Mersmann Bernd Bischl Heike Trautmann Markus Wagner Jakob Bossek Frank Neumann 《Annals of Mathematics and Artificial Intelligence》2013,69(2):151-182
Meta-heuristics are frequently used to tackle NP-hard combinatorial optimization problems. With this paper we contribute to the understanding of the success of 2-opt based local search algorithms for solving the traveling salesperson problem (TSP). Although 2-opt is widely used in practice, it is hard to understand its success from a theoretical perspective. We take a statistical approach and examine the features of TSP instances that make the problem either hard or easy to solve. As a measure of problem difficulty for 2-opt we use the approximation ratio that it achieves on a given instance. Our investigations point out important features that make TSP instances hard or easy to be approximated by 2-opt. 相似文献