全文获取类型
收费全文 | 345篇 |
免费 | 20篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 36篇 |
金属工艺 | 3篇 |
机械仪表 | 9篇 |
建筑科学 | 33篇 |
矿业工程 | 5篇 |
能源动力 | 6篇 |
轻工业 | 68篇 |
水利工程 | 4篇 |
石油天然气 | 2篇 |
无线电 | 15篇 |
一般工业技术 | 34篇 |
冶金工业 | 109篇 |
原子能技术 | 1篇 |
自动化技术 | 39篇 |
出版年
2021年 | 2篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 4篇 |
2013年 | 19篇 |
2012年 | 15篇 |
2011年 | 16篇 |
2010年 | 8篇 |
2009年 | 12篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 9篇 |
2005年 | 9篇 |
2004年 | 7篇 |
2003年 | 11篇 |
2002年 | 9篇 |
2001年 | 16篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 43篇 |
1997年 | 22篇 |
1996年 | 14篇 |
1995年 | 11篇 |
1994年 | 8篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1978年 | 2篇 |
1977年 | 8篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有365条查询结果,搜索用时 78 毫秒
1.
Mine water pollution is a major cause of surface- and groundwater pollution in former mining districts throughout Europe. It is a potential barrier to achieving good status water bodies, which is a requirement of the EU Water Framework Directive. In the UK, a concerted effort has been made over the last decade or so to address the scientific and practical challenges relating to the remediation of mine water pollution. However, most of this work has focused on remediation of point sources of pollution (typically arising from abandoned mines and shafts), while the behaviour of mine water at the groundwater-surface water interface (the "hyporheic zone") has received far less attention in relevant scientific and engineering literature. The extent of mine water pollution and capacity for its attenuation at the hyporheic zone has not been well quantified while, furthermore, the complex chemical and microbial processes occurring there (specifically with reference to mining-derived pollutants) have not been investigated in any depth. The absence of such data may relate, in a large part, to the difficulty in physically measuring volumes and concentrations associated with these river inputs/exports. A far greater body of literature addresses biogeochemical processes at the hyporheic zone (especially relating to manganese), albeit many such articles relate to aqueous metal dynamics in general, rather than mine water specifically. This paper presents a review of the natural attenuation processes that may limit the movement and availability of mining-derived pollutants at the groundwater-surface water (GW-SW) interface, and specifically within the hyporheic zone. A substantial part focuses on precipitation and adsorption processes at the hyporheic zone, as well as discussing the role of microbial processes in governing metal ion mobility. 相似文献
2.
Andrew J. Hartshorn George Prpich Andrew Upton Jitka Macadam Bruce Jefferson Peter Jarvis 《Water and Environment Journal》2015,29(1):16-26
This investigation explores the use of five‐parameter logistic curve fitting in quantifying turbidity robustness and risk scoring in clarification and filtrations stages of several surface water treatment works in the Anglian Water region of the United Kingdom. The approach taken reviews different scoring systems and addresses issues of weighting, averages and variability in robustness performance using turbidity robustness indices (TRIs). It also proposes an area‐based risk scoring profile to assess performance [relative area profile for T90 (RAP90)]. The metrics produced are considered to be a logical and rational way to help prioritise where resources for water treatment operation should be deployed. 相似文献
3.
Performance of different advanced oxidation processes for tertiary wastewater treatment to remove the pesticide acetamiprid 下载免费PDF全文
4.
S.J. Pennycook S.D. Hammond S.A. Wright J.A. Herdman I. Miller S.A. Jarvis 《Journal of Parallel and Distributed Computing》2013
This paper reports on the development of an MPI/OpenCL implementation of LU, an application-level benchmark from the NAS Parallel Benchmark Suite. An account of the design decisions addressed during the development of this code is presented, demonstrating the importance of memory arrangement and work-item/work-group distribution strategies when applications are deployed on different device types. The resulting platform-agnostic, single source application is benchmarked on a number of different architectures, and is shown to be 1.3–1.5× slower than native FORTRAN 77 or CUDA implementations on a single node and 1.3–3.1× slower on multiple nodes. We also explore the potential performance gains of OpenCL’s device fissioning capability, demonstrating up to a 3× speed-up over our original OpenCL implementation. 相似文献
5.
W. H. Sillekens D. J. Jarvis A. Vorozhtsov V. Bojarevics C. F. Badini M. Pavese S. Terzi L. Salvo L. Katsarou H. Dieringa 《Metallurgical and Materials Transactions A》2014,45(8):3349-3361
The performance of structural materials is commonly associated with such design parameters as strength and stiffness relative to their density; a recognized means to further enhance the weight-saving potential of low-density materials is thus to improve on their mechanical attributes. The European Community research project ExoMet that started in mid-2012 targets such high-performance aluminum- and magnesium-based materials by exploring novel grain refining and nanoparticle additions in conjunction with melt treatment by means of external fields (electromagnetic, ultrasonic, and mechanical). These external fields are to provide for an effective and efficient dispersion of the additions in the melt and their uniform distribution in the as-cast material. The consortium of 27 companies, universities, and research organizations from eleven countries integrates various scientific and technological disciplines as well as application areas—including automotive, aircraft, and space. This paper gives an overview of the project, including its scope for development and organization. In addition, exemplary results are presented on nanoparticle production and characterization, mixing patterns in metal melts, interface reactions between metal and particles, particle distribution in the as-cast composite materials, and mechanical properties of the as-cast composite materials. The application perspective is considered as well. 相似文献
6.
An environmental comparison is made between two gamma titanium aluminide (γ-TiAl) alloys, Ti–46Al–8Nb and Ti–46Al–8Ta (at.%), and the standard nickel superalloy, INC713LC used for investment cast components in the low pressure (LP) turbine section of aero-engines. Over the complete lifetime, weight reduction by direct replacement could give significant reductions in CO2 emissions, greatly outweighing the impact of other environmental emissions. 相似文献
7.
Low energy ballasted flotation 总被引:1,自引:0,他引:1
A novel process which involves the replacement or supplementation of bubbles in the dissolved air flotation process with low density beads is presented. The work comprised a series of bench-scale flotation trials treating three commonly encountered algal species (Microcystis, Melosira and Chlorella) that were removed in a flotation cell configured as either: conventional dissolved air flotation (DAF); ballasted flotation using low density 70 μm glass beads with a density of 100 kg m−3; or a hybrid process of ballasted flotation combined with conventional DAF. Results indicated that the bead only system was capable of achieving better residual turbidity than standard DAF at bead concentrations of 500 mg L−1. Addition of beads in combination with standard DAF reduced turbidity further to even lower residual turbidity levels. Algae removal was improved when glass beads were dosed, but removal was dependent on algal species. Microcystis was removed by 97% for bead only systems and this removal did not change significantly with the addition of air bubbles. Melosira was the next best removed algae with bead only dosed systems giving similar removals to that achieved by standard DAF using a 10% air recycle ratio (81 and 76% removal respectively). Chlorella was the least well removed algae by bead only systems (63% removal). However, removal was rapidly improved to 86% by the addition of air bubbles using only a 2% recycle ratio. Energy estimations suggested that at least a 50% energy reduction could be achieved using the process offering a potential route for future development of low energy separation processes for algae removal. 相似文献
8.
Experience with user-centred requirements engineering 总被引:1,自引:1,他引:0
This paper describes the application of human–computer interaction (HCI) principles and methods to requirements engineering
in a case study development of a visualisation tool, ADVISES, to support epidemiological research. The development approach
consisted of scenario-based design and analysis of the users’ tasks and mental model of the domain. Prototyping and storyboarding
techniques were used to explore design options with users as well as specifying functionality for two versions of the software
to meet the needs of novice and expert users. Application of HCI functional allocation heuristics to guide system requirements
decisions is explained. An evaluation of the prototype was carried out to assess the extent to which the expert model would
support public health professionals in their analysis activities. The results of the design exploration requirements analysis
study are reported. The implications of scenario-based design exploration, functional allocation and software architecture
are discussed. 相似文献
9.
Neil V. Jarvis 《溶剂提取与离子交换》2013,31(6):1077-1088
The small-scale recovery and separation of the actinides U, Np, Pu and Am using the commercial product, Lewatit OC 1023. has been studied. Conditions under which these actinides may be extracted or eluted and methods for separation of any combination of these elements are presented. A separation scheme for all four actinides achieved complete separation of Np from U and Am from Pu and U. Good separation of U, Np and Pu was achieved. Quantitative separation is possible by repeating the procedure. Since Np and Am follow one another in the above scheme, a further procedure for their quantitative separation is presented. Reductants investigated for separation of Pu from U were ferrous sulfamate and hydroxylamraonium nitrate. The latter is only effective if small amounts of U are present. The behaviour of Ru and Zr under the conditions for the separation of U, Np, Pu and Am was also investigated The behaviour of these two troublesome elements was shown to be similar to that in the purex process. 相似文献
10.
The permeation and separation characteristics of four different alcohol—water systems through cellophane and poly(vinyl alcohol) membranes were investigated. The homologous series of linear alcohols n-propanol, ethanol, and methanol as well as isopropanol were studied. A specially designed permeation cell was used to study permeation rates at temperatures ranging from 30° to 50°C. The dependency of both permeation and separation on the molecular size and shape of the permeating species was discussed qualitatively. The temperature dependence of the permeation rate for both pure compounds and binary mixtures was expressed by Arrhenius-type relationships. The rate was found to increase with increasing temperature while the separation decreased. Activation energies of 4–9 kcal/mole were calculated for alcohol—water solutions through cellophane, and of 8–15 kcal/through poly(vinyl alcohol). Departure of permeation rates from the ideal rates were discussed in terms of permeation “enhancement” or “depression.” These phenomena were explained in terms of both the plasticizing action of water and the “clustering” of water molecules within the polymer network. 相似文献