全文获取类型
收费全文 | 1684篇 |
免费 | 69篇 |
专业分类
电工技术 | 16篇 |
综合类 | 3篇 |
化学工业 | 552篇 |
金属工艺 | 29篇 |
机械仪表 | 27篇 |
建筑科学 | 137篇 |
矿业工程 | 6篇 |
能源动力 | 40篇 |
轻工业 | 182篇 |
水利工程 | 5篇 |
石油天然气 | 1篇 |
无线电 | 94篇 |
一般工业技术 | 329篇 |
冶金工业 | 215篇 |
原子能技术 | 15篇 |
自动化技术 | 102篇 |
出版年
2021年 | 22篇 |
2019年 | 21篇 |
2018年 | 23篇 |
2017年 | 28篇 |
2016年 | 36篇 |
2015年 | 39篇 |
2014年 | 43篇 |
2013年 | 69篇 |
2012年 | 62篇 |
2011年 | 76篇 |
2010年 | 45篇 |
2009年 | 61篇 |
2008年 | 63篇 |
2007年 | 54篇 |
2006年 | 53篇 |
2005年 | 48篇 |
2004年 | 53篇 |
2003年 | 34篇 |
2002年 | 36篇 |
2001年 | 30篇 |
2000年 | 28篇 |
1999年 | 18篇 |
1998年 | 28篇 |
1997年 | 31篇 |
1996年 | 37篇 |
1995年 | 26篇 |
1994年 | 21篇 |
1993年 | 33篇 |
1992年 | 19篇 |
1991年 | 28篇 |
1990年 | 21篇 |
1989年 | 27篇 |
1988年 | 16篇 |
1986年 | 15篇 |
1985年 | 31篇 |
1984年 | 34篇 |
1983年 | 28篇 |
1982年 | 27篇 |
1981年 | 30篇 |
1980年 | 28篇 |
1979年 | 22篇 |
1978年 | 27篇 |
1976年 | 19篇 |
1975年 | 18篇 |
1974年 | 28篇 |
1973年 | 20篇 |
1972年 | 17篇 |
1971年 | 15篇 |
1970年 | 16篇 |
1969年 | 17篇 |
排序方式: 共有1753条查询结果,搜索用时 15 毫秒
1.
Heinz Blenke Beate Farys-Kahle Carl-Max Freiherr Von Meysenbug Helmut Weimer 《化学,工程师,技术》1985,57(5):381-390
Rationalizing drawings for chemical apparatus . For small and medium-sized manufacturers of apparatus, producing drawings may constitute a disproportionate waste of time and personnel, particularly when no new designs are involved but only modification or improvement of drawings supplied by the customer. One possibility for rationalizing drawing is to simplify the old-fashioned approach by using symbols for frequently drawn or standard items, or by listing alphanumerically. This presumes a kind of systematization permitting determination of those symbols and their reasonable use, as well facilitating rationalization by means of data processing. There are different approaches to computer-aided drawing (from computer controlled drawing-board to interactive screens); here a CAD programme is presented which was especially developed for graphic presentation of chemical apparatus, and which can be used without learning a programming language. 相似文献
2.
3.
Peter Horn Peter Schaaf Brigitte Holbach Stefan Hölzl Heinz Eschnauer 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1993,196(5):407-409
For provenance assignments of wines strontium isotope ratios can be used because soils from different wine-growing regions, and hence the wines grown there, each show specific ratios. Some successful applications are demonstrated.
87Sr/86Sr aus Gestein und Boden in Rebe und Wein
Zusammenfassung Zur Herkunftsbestimmung von Weinen können Strontium-Isotopenverhältnisse herangezogen werden, da die Böden verschiedener Weinbaugebiete, und damit die dort gezogenen Weine, jeweils spezifische Verhältnisse aufweisen. Einige erfolgreiche Anwendungen werden demonstriert.相似文献
4.
5.
6.
7.
Economic ideas and processes are becoming increasingly integrated with more traditional engineering and hydrologic models
of water management problems. Combining economic management concepts and performance indicators with an engineering-level
of understanding of a hydrologic system can provide results and insights more directly relevant for water management decisions
and policies. When such models are developed and used with involvement of stakeholders, they can become a basis for shared
understanding of water problems as a foundation for negotiated management and policy solutions. When implemented with optimization
software, integrated hydro-economic models also can suggest promising innovative solutions for policy-makers to consider.
Their applications to river basin management problems are reviewed. Economic and integrated economic-engineering-hydrologic
modeling is then discussed in the context of the evolving European Water Framework Directive. Relevant items are cost recovery
and water pricing, cost-effectiveness of water management measures, and public participation in decision processes. 相似文献
8.
Improving the vacuum would increase the insulation capacity of commercially available glass containers by a factor of about two. To do this, pressures of 10?4 mbar must be attained. Different approaches were taken to meet this objective. As an alternative to today's commonly practiced sealing method, three possibilities are introduced which eliminate the necessity of pump stub narrowing which causes reduced conductance. Furthermore, depending on the sealing process used, the gases occuring during sealing are either avoided completly or they can at least be reduced by having the chance of exact temperature control resp. by a lower separation temperature. A completly different approach was taken by using Getters, of which a metal hydride on a TiVMn base proved especially suitable. It is activated by heat and can be integrated into the normal production process without any problem. Aside from a shorter pump period, the added advantage here is the containment of the gasses occuring during sealing as well as that of the longterm gasses. 相似文献
9.
10.
Karl Heinz Schwalbe 《Engineering Fracture Mechanics》1993,45(6):751-758
The Engineering Treatment Model (ETM) provides a means for estimating the load line displacement of a cracked body. Under contained yielding conditions the model uses available linear elastic solutions with an Irwin-type plasticity correction of the crack length. The magnification factor (F/Fy)1/n describing the material's strain hardening behaviour is applied for extrapolation into the regime of net section yielding. Comparison of ETM estimates with finite element and experimental results shows that the assumptions of the model are realistic. 相似文献