全文获取类型
收费全文 | 365篇 |
免费 | 26篇 |
国内免费 | 13篇 |
专业分类
电工技术 | 8篇 |
综合类 | 33篇 |
化学工业 | 75篇 |
金属工艺 | 4篇 |
机械仪表 | 35篇 |
建筑科学 | 46篇 |
矿业工程 | 10篇 |
能源动力 | 16篇 |
轻工业 | 11篇 |
水利工程 | 5篇 |
石油天然气 | 77篇 |
无线电 | 6篇 |
一般工业技术 | 51篇 |
冶金工业 | 2篇 |
原子能技术 | 2篇 |
自动化技术 | 23篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 10篇 |
2019年 | 7篇 |
2018年 | 17篇 |
2017年 | 11篇 |
2016年 | 20篇 |
2015年 | 16篇 |
2014年 | 18篇 |
2013年 | 35篇 |
2012年 | 14篇 |
2011年 | 20篇 |
2010年 | 28篇 |
2009年 | 26篇 |
2008年 | 20篇 |
2007年 | 32篇 |
2006年 | 21篇 |
2005年 | 28篇 |
2004年 | 16篇 |
2003年 | 12篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有404条查询结果,搜索用时 15 毫秒
1.
The present study investigates the decomposition of N-Methyl-2-Pyrolidone (NMP) using conventional ozonation (O3), ozonation in the presence of UV light (UV/O3), hydrogen peroxide (O3/H2O2), and UV/H2O2 processes under various experimental conditions. The influence of solution pH, ozone gas flow dosage, and H2O2 dosage on the degradation of NMP was studied. All ozone-based advanced oxidation processes (AOPs) were efficient in alkaline medium, whereas the UV/H2O2 process was efficient in acidic medium. Increasing ozone gas flow dosage would accelerate the degradation of NMP up to certain level beyond which no positive effect was observed in ozonation as well as UV light enhanced ozonation processes. Hydrogen peroxide dosage strongly influenced the degradation of NMP and a hydrogen peroxide dosage of 0.75 g/L and 0.5 g/L was found to be the optimum dosage in UV/H2O2 and O3/H2O2 processes, respectively. The UV/O3 process was most efficient in TOC removal. Overall it can be concluded that ozonation and ozone-based AOPs are promising processes for an efficient removal of NMP in wastewater. 相似文献
2.
The size of bubbles created in the flotation process is of great importance to the efficiency of the mineral separation achieved. Meanwhile, it is believed that frother transport between phases is perhaps the most important reason for the interactive nature of the phenomena occurring in the bulk and froth phases in flotation, as frother adsorbed in the surface of rising bubbles is removed from the bulk phase and then released into the froth as a fraction of the bubbles burst. This causes the increased concentration in the froth compared to the bulk concentration, named as frother partitioning. Partitioning reflects the adsorption of frother on bubbles and how to influence bubble size is not known. There currently exists no such a topic aiming to link these two key parameters. To fill this vacancy, the correspondence between bubble size and frother partitioning was examined. Bubble size was measured by sampling-for-imaging (SFI) technique. Using total organic carbon (TOC) analysis to measure the frother partitioning between froth and bulk phases was determined. Measurements have shown, with no exceptions including four different frothers, higher frother concentration is in the bulk than in the froth. The results also show strong partitioning giving an increase in bubble size which implies there is a compelling relationship between these two, represented byCFroth/CBulk andD32. TheCFroth/CBulk andD32 curves show similar exponential decay relationships as a function of added frother in the system, strongly suggesting that the frother concentration gradient between the bulk solution and the bubble interface is the driving force contributing to bubble size reduction. 相似文献
3.
Interorganizational systems (IOS) may provide substantial benefits, however many organizations are reluctant to implement
them. This empirical research takes a novel approach and develops a model of IOS feasibility, which is based on the Theory
of Constraints (TOC). It introduces the notion of maximal infeasibility, which is the highest among the values of five factors:
economic infeasibility, organizational infeasibility, technological infeasibility, risks, and lack of financial resources.
The highest value was selected because implementation is hindered even if only one of the feasibility requirements is not
fulfilled. Data collected from 139 medium and large Israeli business organizations validated the model, and indicated that
strategic motivation is the main driving force for an organization to initiate or to join an IOS, while the main barriers
are organizational infeasibility issues such as lack of management support or uninterested potential partners. Adopting a
TOC approach to IOS implementation may assist organizations to overcome these obstacles and increase the chance of a successful
implementation.
An earlier shorter version of this paper was presented at WEB 2006, a pre-ICIS workshop on e-business, in Milwaukee, WI. 相似文献
4.
采用纳滤法处理电厂离子交换树脂再生废水,试验结果表明:废水中绝大部分有机污染物的分子量小于1 000,且含有的大量C l-;以出水的TOC浓度来评价纳滤试验的处理效果比CODC r值更合理,采用纳滤法处理废水,出水的TOC浓度将稳定在14~18 mg/L范围内,达到废水的处理要求. 相似文献
5.
6.
针对中国东北通化地区页岩层理的发育特点,根据两个方向的三轴压缩实验和纵、横波速度测试,分析了页岩弹性模量、泊松比和纵横波速度在不同方向的变化规律.实验数据分析表明:不同围压条件下页岩各向异性参数e与γ间存在线性相关性,应用线性回归建立的经验公式可为二者相互预测或测试提供参考;有利储层岩样的各向异性程度明显大于不利储层;... 相似文献
7.
有机化工废水COD与TOC的相关性 总被引:1,自引:0,他引:1
研究了有机化工废水COD与TOC的相关性。用Rosemount DC-85A有机总碳测定仪测定了有机废水的TOC,并通过TOC回归方程(COD=a+bTOC)的表达,发现它们有很好的相关性。可以用TOC值作有机化工废水污染的快速监测。 相似文献
8.
一种新的TOC含量拟合方法研究与应用 总被引:2,自引:0,他引:2
由于取样的限制,通常在烃源岩评价中往往只能获得十分有限的实测烃源岩的TOC含量数据。但随着我国多数盆地精细勘探的深入,需要更加精细的烃源岩评价,因此,人们对测井数据拟合烃源岩的TOC含量变化越来越重视。目前该技术最先进的是人工神经网络拟合方法,但多种神经网络在拟合高成熟度碳酸盐岩烃源岩地层的TOC含量时相关性均不够高。针对研究区内烃源岩的特点,尝试了一种用图版分类-模糊排队-BP神经网络联合拟合TOC含量的新方法。利用该方法对鄂尔多斯盆地马家沟组的测井资料和实测总有机碳资料进行数据处理,将结果与ΔlogR方法、模糊神经网络方法的结果相比较,证实该方法的结果与实测值有更好的相关性,为系统了解鄂尔多斯盆地下古生界烃源岩发育提供了一定的科学依据。 相似文献
9.
This paper analyses a case study of a dynamic expert system which was developed according to the theory of constraints (TOC) approach, and implemented at the Ashdod refinery of Oil Refineries Ltd in Israel, as part of an overall improvement process based on the focused management philosophy. The unique feature of the system is its ability to cope with dynamic bottlenecks typical of the continuous process industry, as well as frequent shifts from an external market constraint to internal capacity constraints. The paper examines the development and implementation stages, describes the expert system along with the new process control, and evaluates its impact. The system creates a dynamic, effective and immediate link between the production planning and the operation control, which enables the oil refinery to maximize its profits. During the first two years of its use, the system generated over $3 million of estimated benefits. Finally, we suggest practical implications to assist organizations in developing and utilizing similar applications, emphasizing knowledge gathering and maintenances, which are the major challenges facing expert systems projects. 相似文献
10.
Alex Coman 《国际生产研究杂志》2013,51(20):5677-5689
Despite the problems involved in its use, SWOT (strengths-weaknesses-opportunities-threats) analysis remains a major strategic tool for listing the strengths and weaknesses of an organisation, for recording the major strengths and translating them into value. This paper presents a straightforward methodology for making a structured analysis of strengths and weaknesses, based on an analysis of important value-creating events and the strengths and weaknesses that caused these events. The focused SWOT methodology distils the strengths and weaknesses into core competences and core problems, by using the core-competence tree and the current-reality tree. The core competences and core problems are then linked into a plan of action aimed at preserving and leveraging the organisation's core competences, while defending against exposure to core problems. Applications of the methodology are presented and it is demonstrated in a detailed case study. 相似文献