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41.
42.
对于完整的控制和安全系统,建立强大的防护体系是否是一项可以确保安全仪表系统商业连续性的必要投资? 相似文献
43.
创新推动无线技术的发展,成功的应用充分证明无线技术的经济、可靠、安全和易用性。 相似文献
44.
Bob Scannell 《电子产品世界》2006,(13)
传感器对工业系统设计中的性能、可靠性、安全性和自身成本等方面具有提供重大改进的潜能.涉及惯性传感器的应用案例包括平台稳定性、工业机器的运动控制、安全性设备、天线稳定性、机器人技术、导航、机械调平以及许多其它的应用.但是,在优秀的传感器技术与其在重要工业系统中的实现之间长期以来一直处于空白阶段. 相似文献
45.
In this research, a number of process modifications to the lime-soda softening process were examined, including utilization of high Mg-content lime, addition of MgCl2, and the recycling of softening sludge, in order to improve the removal of natural organic matter (NOM) and reduce the formation of disinfection byproducts (DBPs). Jar test results showed that dissolved organic carbon (DOC) removal increased and trihalomethane (THM) formation was reduced as the magnesium in hydrated lime increased, and was directly correlated with the amount of magnesium removed from the system. However, a dolomitic quick lime hydrated under atmospheric conditions resulted in less effective DOC removal due to a lack of available Mg, and subsequently, less co-precipitation of Mg(OH)2-NOM complexes. The addition of MgCl2 to the raw water also increased DOC removal and reduced THM formation in both the presence and absence of softening sludge, with DOC removal increasing as softening sludge and magnesium dosages increased. As high as 43% removal of DOC was achieved at the stoichoimetric lime-soda ash dose in the presence of 457 mg/L sludge and 7.5 mg/L MgCl2, as compared to only 13% removal in the absence of sludge and MgCl2. The recycling of softening sludge had little or no effect on the hardness and the level of inorganic elements in treated water. The results presented here provide new approaches for improving DBP precursor removal during lime-soda softening without significantly increasing lime and soda ash dosage or the generation of waste sludge. 相似文献
46.
The introduction of inexpensive microcomputer hardware and innovative user‐oriented software packages has had a significant impact on the traditional data processing procedures of the construction industry. Copyrighted electronic spreadsheet packages such as VisiCalc and SuperCalc are now available to practically all microcomputer users. These spreadsheet packages provide construction contractors, owners and managers with a versatile management tool that can be applied to a wide range of construction‐related problems. The overall capabilities of spreadsheet packages are examined and specific applications of interest to the construction management community are presented. 相似文献
47.
48.
Discusses a federal proposal that would limit the amount of health insurance an employer could provide tax free to employees. This could lead to the elimination of cost-effective health benefits such as mental health coverage, drug and alcohol abuse programs, and other preventive care services. The proposal threatens health security and is unlikely to provide additional tax revenues for the government. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
49.
Stability of particle flocs upon addition of natural organic matter under quiescent conditions 总被引:7,自引:0,他引:7
In this research, the influence of two natural organic polymers (polysaccharide and humic acid) on the stability of colloidal aggregates was examined. The primary objective of this research was to determine whether addition of organic matter to floc suspensions results in the fragmentation or stabilization of aggregates. A second objective was to determine how the size of aggregates and the composition of organic matter influence the floc breakup or stabilization process. It was found that the stability of aggregates depended on the type of organic material present as well as floc size. For example, humic acid increased the stability of aggregates more effectively than polysaccharides of larger size. It was also found that the addition of humic acid or polysaccharide generally decreased the rate of coagulation of small aggregates but had less influence on large aggregates. In no case did the addition of polysaccharide or humic acid result in the fragmentation of particle aggregates. The existence of strong interparticle forces within flocs prevented aggregate breakup upon adsorption of natural organic polymers. The results presented here provide important new information regarding the influence of NOM on the behavior of particles in aquatic systems. 相似文献
50.
Vera Hollink Maarte van Someren Bob J Wielinga 《User Modeling and User-Adapted Interaction》2007,17(1-2):183-214
Users of web sites often do not know exactly which information they are looking for nor what the site has to offer. The purpose
of their interaction is not only to fulfill but also to articulate their information needs. In these cases users need to pass
through a series of pages before they can use the information that will eventually answer their questions. Current systems
that support navigation predict which pages are interesting for the users on the basis of commonalities in the contents or
the usage of the pages. They do not take into account the order in which the pages must be visited. In this paper we propose
a method to automatically divide the pages of a web site on the basis of user logs into sets of pages that correspond to navigation
stages. The method searches for an optimal number of stages and assigns each page to a stage. The stages can be used in combination
with the pages’ topics to give better recommendations or to structure or adapt the site. The resulting navigation structures
guide the users step by step through the site providing pages that do not only match the topic of the user’s search, but also
the current stage of the navigation process. 相似文献