全文获取类型
收费全文 | 517篇 |
免费 | 8篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 9篇 |
综合类 | 18篇 |
化学工业 | 272篇 |
金属工艺 | 6篇 |
机械仪表 | 14篇 |
建筑科学 | 78篇 |
矿业工程 | 2篇 |
能源动力 | 38篇 |
轻工业 | 37篇 |
水利工程 | 1篇 |
石油天然气 | 5篇 |
无线电 | 4篇 |
一般工业技术 | 22篇 |
冶金工业 | 14篇 |
原子能技术 | 2篇 |
自动化技术 | 4篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 16篇 |
2019年 | 10篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 13篇 |
2014年 | 25篇 |
2013年 | 23篇 |
2012年 | 37篇 |
2011年 | 50篇 |
2010年 | 51篇 |
2009年 | 23篇 |
2008年 | 37篇 |
2007年 | 32篇 |
2006年 | 19篇 |
2005年 | 42篇 |
2004年 | 24篇 |
2003年 | 30篇 |
2002年 | 25篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1987年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有526条查询结果,搜索用时 0 毫秒
1.
One method to reduce fouling is to extend the induction time by a defined modification of the interfacial interactions between the heat transfer surface and the crystalline deposit. Since these interactions are a result of both molecular and mechanical forces, two approaches for fouling mitigation have been developed: (a) Modification of the energy related properties of the heat transfer surface and (b) Modification of the geometry related properties of the heat transfer surface. 相似文献
2.
为提高四角喷燃液态排渣锅炉运行的安全性和经济性,从锅炉原理和实际运行情况对锅炉高温受热面的积灰与结焦问题进行了分析,并提出了解决办法,同时提出了一种基于热力学模型的受热面积灰状态实时监测方法。 相似文献
3.
4.
防止设备结垢延长乙烯装置运行周期 总被引:2,自引:1,他引:2
设备结垢堵塞问题已成为乙烯装置长周期运转的难点。笔者重点论述了急冷油塔和冷箱的结垢问题及防范措施。 相似文献
5.
本文介绍了目前MBR的主要类型、膜污染情况、膜清洗方式以及MBR在不同领域的应用情况和工程实例,并对MBR技术未来的发展趋势进行了预测。 相似文献
6.
电站锅炉污垢费用估算 总被引:8,自引:4,他引:8
该文参照国际通用算法提出了一种电站锅炉污垢费用的估算方法,该法将锅炉污垢造成的经济损失分别按冗余面积、附加燃料、附加维护3个方面,根据某厂350MW机组锅炉的现场实测数据逐项进行评估.继而将所得结果按2000年我国火电机组装机容量推算出该年我国锅炉污垢导致的经济损失约为100.08亿元,约占当年GDP的0.11%. 相似文献
7.
《分离科学与技术》2012,47(4):483-503
Abstract Historical development, principal operation, different ways of experimental realization, and typical examples of application of countercurrent electrophoresis are reviewed. The separation process is principally capable of being applied to all types of ions, as far as any difference is shown in their ionic behavior. Different types of columns can be adapted to varying amounts of substance from approximately 10?6 mole up to several moles (in the laboratory scale). The production of high purity components and the use of the column as an absolute ion filter are further possible applications. 相似文献
8.
Membranes are located in a membrane module that physically seals and isolates the feed stream from the permeate flux in membrane bioreactors (MBRs). Therefore, module type, structure, and geometrical configuration are critical design considerations affecting membrane performance in MBRs. In this study, impact of membrane module design on treatment and filtration performance of MBRs was investigated. For this purpose, two flat sheet membrane modules with different outlet structures and module geometries, including rectangular- and D-shaped, were tested. In addition to the differences in outlet structure and module geometry, size of circular structures which supported membranes in rectangular- and D-shaped modules differed from each other. Considering the results, permeate quality was not affected from the change in the module design. However, the most remarkable impact of the module design was observed on the transmembrane pressure (TMP) evolution and fouling potential. D-shaped membrane module including smaller circular structures resulted in a decrease in fouling potential and thus, this module could be operated longer time in comparison to rectangular-shaped membrane module without a severe TMP increase. The observed differences in TMP increase and fouling potential lead to the hypothesis that module design is a critical factor affecting filtration performance in MBRs. 相似文献
9.
Mehdi Koohmishi 《Soils and Foundations》2019,59(6):2265-2278
The aggregate in the ballast layer of the railway track structure degrades due to the splitting of single particles and the abrasion of the angular corners, resulting in a ballast course comprised of degraded aggregate with a lower drainage potential. In the present study, the hydraulic conductivity of clean, degraded and clay-fouled degraded ballast specimens was evaluated considering the initial particle size distribution of aggregate and the degradation mechanism to investigate the permeability of ballast fouled by both internal and external factors. First, degraded ballast aggregate was generated by using a large-scale impact loading testing apparatus. Then, a large-scale constant head permeability test was performed to estimate the hydraulic conductivity of degraded ballast aggregate contaminated with clay. Based on the obtained results, the flow regime through extremely degraded ballast remained between a completely turbulent regime (observed in the case of clean ballast) and a laminar flow regime. Darcy’s law was shown to be valid for degraded aggregate samples contaminated with clay. While the degradation of the aggregate had the expected effect of reducing hydraulic conductivity, the abrasion of asperities was shown to have an even greater impact on hydraulic conductivity. Also, the further degradation of aggregate under impact loading was shown to accelerate the reduction in the permeability of clay-fouled degraded ballast to an unacceptable extent. 相似文献
10.
Conventional water reclamation processes, such as membrane bioreactors, are not always effective in removal of pharmaceuticals and personal care products (PPCPs), endocrine disrupting chemicals (EDCs) and/or N-nitrosodimethylamine (NDMA), even with the reverse osmosis (RO) membrane process. A study was conducted, at a NEWater factory in Singapore, to compare a conventional ultrafiltration (UF) membrane /RO treatment process with a treatment train having the HiPOx unit, an advanced oxidation process (AOP), which was installed between the UF and the RO unit operations. By incorporating the HiPOx into the UF/RO treatment process, following results were observed; 1) increased removal of PPCPs, EDCs and NDMA, 2) improvement in ultraviolet transmission (UVT) of the RO permeate, 3) enhanced removal of TOC and color, and increased UVT of the RO brine, 4) suppression of the increase in the RO transmembrane pressure by organic fouling. 相似文献