全文获取类型
收费全文 | 1141篇 |
免费 | 26篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 9篇 |
综合类 | 15篇 |
化学工业 | 78篇 |
金属工艺 | 21篇 |
机械仪表 | 16篇 |
建筑科学 | 651篇 |
矿业工程 | 4篇 |
能源动力 | 30篇 |
轻工业 | 87篇 |
水利工程 | 9篇 |
石油天然气 | 2篇 |
无线电 | 30篇 |
一般工业技术 | 92篇 |
冶金工业 | 26篇 |
原子能技术 | 5篇 |
自动化技术 | 93篇 |
出版年
2023年 | 7篇 |
2021年 | 15篇 |
2020年 | 17篇 |
2019年 | 4篇 |
2018年 | 17篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 12篇 |
2014年 | 20篇 |
2013年 | 113篇 |
2012年 | 27篇 |
2011年 | 21篇 |
2010年 | 17篇 |
2009年 | 32篇 |
2008年 | 20篇 |
2007年 | 8篇 |
2006年 | 24篇 |
2005年 | 50篇 |
2004年 | 41篇 |
2003年 | 42篇 |
2002年 | 48篇 |
2001年 | 34篇 |
2000年 | 50篇 |
1999年 | 41篇 |
1998年 | 49篇 |
1997年 | 43篇 |
1996年 | 42篇 |
1995年 | 43篇 |
1994年 | 43篇 |
1993年 | 29篇 |
1992年 | 44篇 |
1991年 | 34篇 |
1990年 | 23篇 |
1989年 | 38篇 |
1988年 | 25篇 |
1987年 | 16篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 10篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 9篇 |
1979年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1971年 | 4篇 |
1969年 | 2篇 |
排序方式: 共有1168条查询结果,搜索用时 78 毫秒
1.
This study, which is based on responses from over 300 individuals in England and Wales, explores how a willingness to use a water-recycling system of specific configuration varies against a number of factors which are linked to system design, system scale, system context, and water-conservation behaviour. Findings show that there is broad willingness to accept in-house water recycling provided that public health is not compromised. 相似文献
2.
Anguilla is a UK overseas (non-independent) territory in the Caribbean. It is a small middle-income island with a population of 13 000, and recent statistics indicate that it is more dependent on tourism than any other country or territory in the world. Rapid population growth and development have placed more emphasis on the need for human health and environmental protection. For the first time, a systematic water-quality monitoring programme has been developed, based on the realities of the local situation, e.g. low resource base, limited capabilities, dependence on household rainwater catchment, storage cisterns, and a poor water-supply network. Development of the programme incorporated the key themes of pragmatic, realistic, incremental, responsive, and consultative approaches. 相似文献
3.
Kyle A. Crawford
Osama K. Eyada PhD PE
《Computers & Industrial Engineering》1989,17(1-4):298-302The 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
4.
In the present investigation, the process model developed in Part I has been applied to evaluate the microstructure and strength
evolution during active brazing of ceramics. As a starting point, reaction-layer growth is assumed to occur isothermally with
no restrictions in the supply of reactive element. Different kinds of diagrams are then constructed to show how specific process
variables (e.g. the heating and cooling period, the limiting layer thickness, and the diffusion mechanism) affect the growth
kinetics. It is concluded that the key to improved joint properties lies in control of the reaction-layer thickness through
optimization of the brazing conditions, and an illustration of this is given.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
5.
Water turbidity, surface temperature and circulation of Barton and Wroxham Broads, two of the Norfolk Broads, were studied using one reflective (TM1) and the thermal (TM6) TM band. The results indicated that the through-flowing path of the River Ant in Barton Broad is the major influence on the distribution of these parameters. In Wroxham Broad, both turbidity and surface temperature displayed a uniform distribution. This could be explained by the absence of a predominant direction of flow. 相似文献
6.
An 8-bit, 200 MSPS Folding and Interpolating ADC 总被引:1,自引:0,他引:1
An 8-bit, 200 MSPS folding and interpolating analog-to-digitalconverter, ADC, has been implemented in a 1.2 µmBiCMOS-process. It achieves 7.5 effective bits with a power dissipationof 575mW. The active area is 4mm2. The implementationand measured results are presented. A simple analytical modelfor the interpolation-induced nonlinearity in a folding and interpolatingADC using sinusoidal folding is presented. The bowing of thereference ladder due to interaction with the input stages isanalyzed, and analytical models are derived. 相似文献
7.
During the day, there are considerable variations in the climatic factors prevailing in these regions. This is especially so during the 24-hour daily cycle of the long, hot and dry summer (mid-May to midOctober). Such climatic conditions have had a considerable impact on the daily living pattern of family life in the same season, particularly in the urban areas. During the same 24-hour cycle, they have compelled the inhabitants to shift their living activities both vertically in section and horizontally in plan; they do this in pursuit of more acceptable, if not, desirable internal thermal environmental ambience. 相似文献
8.
9.
T he feasibility of treating a synthetic toxic waste and a petroleum refinery effluent was evaluated using a four-stage, fixed-film aerated bioreactor with a 50 I capacity and a surface area-to-volume ratio of 72. The process performance at various waste strengths and influent flow rates was found satisfactory.
Organic loading proved to be a better operational or design parameter. Treatment efficiency decreased as the loading was increased. An organic loading of 42 g COD/m2d or less is recommended to ensure good quality effluent. The reactor coped with organic and hydraulic overloads because of the good oxygen transfer capacity and the considerable quantity of attached biomass attained. Staging of the reactor was effective in damping excessive loadings.
Treatment of the refinery waste in the bioreactor removed up to 80 per cent of the COD and reduced the oil, sulphide and amm.N concentrations substantially, but polishing of reactor effluent using alum treatment improved effluent quality for potential reuse. 相似文献
Organic loading proved to be a better operational or design parameter. Treatment efficiency decreased as the loading was increased. An organic loading of 42 g COD/m2d or less is recommended to ensure good quality effluent. The reactor coped with organic and hydraulic overloads because of the good oxygen transfer capacity and the considerable quantity of attached biomass attained. Staging of the reactor was effective in damping excessive loadings.
Treatment of the refinery waste in the bioreactor removed up to 80 per cent of the COD and reduced the oil, sulphide and amm.N concentrations substantially, but polishing of reactor effluent using alum treatment improved effluent quality for potential reuse. 相似文献
10.
Jin B. Ong Osama K. Eyada PhD PE Abu S. Masud PhD PE 《Computers & Industrial Engineering》1989,17(1-4):85-89
This paper presents a Knowledge-based system (KBS) developed to allow users, who may not be knowledgeable about sensors, to select sensors suitable for their specific needs. The KBS runs on a micro-computer. The selection criteria are user specified and are based on the desired measurement parameters. The system output includes all of the operational and dimensional parameters of the recommended sensor, price, and vendor information. 相似文献