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171.
Diana Hurdowar-Castro Ioannis Tsanis Ilmar Simanovskis 《Journal of Great Lakes research》2007,33(1):232-252
A 3D transport model is used to perform a comparative analysis of several potential drinking water intakes located along the northwest shore of Lake Ontario between Toronto and Oshawa. The model is specifically used to assess each intake under both long- and short-term transport of a potential pollutant release from the Pickering Nuclear Generating Station and potential and actual pollutant releases from local land sources respectively. A model based on a 500 m grid resolution is calibrated using data collected in the aftermath of the 1992 tritium spill at the Pickering Nuclear Generation Station and subsequently used to simulate long-term transport. A model based on a 100 m grid resolution is verified using drogue studies and used to simulate short-term transport events. Both models are used to assess pollutant levels at each of nine potential intake locations under different wind scenarios and pollutant releases. Field data for the study included water quality and flow measurements from local sewers and rivers, and estimates of pollutant levels from the local waste water treatment plants. This paper describes the model setup for both the long-term and short-term transport models, calibration using field data, long-term transport modeling, short-term transport modeling, and the comprehensive analysis approach used to evaluate the nine potential intake locations proposed. Results indicated that four intakes in particular outperformed other intake locations by maintaining bottom pollutant levels within governmental standards and warning times that exceeded 20 hours. 相似文献
172.
173.
Katsuhiko Fuwa Tatsuo Narikiyo Yasuyuki Funahashi 《Electrical Engineering in Japan》2002,138(4):50-60
A well‐known control system which can reduce the adverse effects of disturbances is a disturbance observer. However, in many cases of mechanical systems, system disturbances which do not satisfy the matching condition may be imposed. Therefore, it may be difficult to reduce the adverse effects of the disturbances by the traditional disturbance observer. In this paper, a method of control system synthesis for disturbance rejection using a dual observer is proposed. This method is based on the zeroing induced by the disturbance localization problem. This problem may be solved by dividing the state space into observable subspace and unobservable subspace. As compared with an H∞ controller based on perfect observation, the usefulness of the proposed control system for disturbance rejection is demonstrated by numerical simulations for a two‐mass spring system. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 50–60, 2002; DOI 10.1002/eej.1138 相似文献
174.
Responds to commentary by I. Silverman (see record 2007-08963-001) entitled "Review of Pure types are rare": Comment on book review. I do not think that either one of us will change his position, and therefore it is up to the interested (yet disinterested) reader to adjudicate our dispute by checking Professor Silverman's book and his references. In the process, the reader will be forced to consider the thought-provoking implications for our mental health system of some of the incidents which the author describes so vividly, and that will not be a bad thing. There is one point, however, which is worth pursuing further here, for Professor Silverman persists in an elementary statistical fallacy. Let us take the situation which he cites, where the base rate for diagnosing schizophrenia is 50%. Suppose with the same base rate the degree of agreement is in fact 53%; this is far above chance level. It must be emphasized, however, that the 53% agreement under discussion came not from a study where the base rate for diagnosing schizophrenia was 50%, but from one where the conditions were far more stringent since the base rate for diagnosing schizophrenia was around 20%. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
175.
176.
氧浓度对近临界水中纤维素分解的影响 总被引:3,自引:0,他引:3
研究了不同初始氧浓度对纤维素在近临界水中分解的影响,实验结果表明,氧浓度显著地影响产物总碳收支平衡,液相不同组分的收率、气体的产量以及气相产物的组成,微量氧对产物总碳收支平衡影响不大,而对液相不同组分的收率有一定的影响。从实验结果可以看出,离子型反应机理在纤维素水解的第一步中起主导作用。而单糖的进一步分解是一个以自由基反应机理为主的过程。 相似文献
177.
178.
针对目前大多数科研单位在内部会计控制中存在的问题,根据财政部颁布的《内部会计控制规范一基本规范》,探讨了科研单位在转制过程中应如何建立和完善内部会计控制制度,以达到防范经营风险,保护资产安全、完整,确保经营管理目标和政策有效实施. 相似文献
179.
Masahide Hojo Yasunori Mitani Toshifumi Ise Kiichiro Tsuji 《Electrical Engineering in Japan》2002,138(3):43-51
The advancement of power electronics technologies has significantly developed the power system stabilizing controllers. Quantitative as well as qualitative evaluation of their effectiveness in power systems is a matter of great importance for the feasibility investigation of these apparatus. In this paper, the possible control region of FACTS controllers with series and/or shunt configuration in a single machine to infinite bus system is formulated in the powerangle curve with a set of algebraic equations. The effectiveness of TCPST (Thyristor‐Controlled Phase Shifting Transformer), SSSC (Static Synchronous Series Compensator), and TCSC (Thyristor‐Controlled Series Compensator) for the improvement of the transient stability is evaluated quantitatively as a numerical example. The correctness of the proposed method has been confirmed by analysis based on the electromagnetic transients simulation with a detailed system model. © 2001 Scripta Technica, Electr Eng Jpn, 138(3): 43–51, 2002 相似文献
180.
云南省水环境状况及问题分析 总被引:2,自引:0,他引:2
根据2000年云南省主要河流水质监测评价结果,全省评价河段总长9280km中,水质为Ⅰ-Ⅲ类的河长占76.3%,总体上,云南省内各大水系水质良好,但水污染总体上正在加重,从1985-2000年,Ⅰ类河长年均减少2.3%,V类河长年均增长0.6%,废污水直接排入江河是引起污染的重要原因。水环境问题已成为社会经济可持续发展的关键问题,要切实加强水资源的保护,科学地开发利用水土资源,为了有效地改善水环境的质量,污染控制应从源头开始并采取综合治理措施。 相似文献