海上石油平台电力系统自励磁研究

研究海上石油平台的电力系统抑制自励磁优化控制问题,当海上石油平台孤岛电力系统黑启动时,由于海缆距离长、分布电容大,易造成发电机的自励磁现象,对系统的电气设备产生极大危害,影响了系统的安全。而应用在陆地电力系统的抑制自励磁措施并不能在孤岛电力系统中完全有效。针对海上石油平台电力系统的特点,提出三种应用在海上油田群电力系统的抑制自励磁方法,即双机带空载海缆黑启动、防止新接入的海缆长度超过临界长度以及并联电抗器黑启动。首先通过同步发电机电枢反应原理分析了同步发电机产生自励磁现象,以劳斯判据来确定产生同步自励磁时发电机参数的判断依据及条件,对某海上油田群电力系统的自励磁情况提出抑制模型,最后利用PSCAD/EMTDC软件对黑启动方案进行仿真,结果证明了方法的有效性,为设计提供了可靠依据。     

Stages of Change in Treatment-Seeking Pathological Gamblers.

The transtheoretical model has been applied to many addictive disorders. In this study, psychometrics properties of the University of Rhode Island Change Assessment (URICA) scale were evaluated in 234 pathological gamblers initiating treatment. Four components were identified--reflective of precontemplation, contemplation, action, and maintenance stages--with internal consistency from .74 to .88. Cluster analyses identified 4 patterns of responding, ranging from ambivalent to active change. The 4 clusters differed with respect to baseline gambling variables and treatment engagement and outcomes assessed 2 months later. A continuous measure of readiness to change was also correlated with gambling severity and predictive of reductions in gambling. This study provides initial support for reliability and validity of the URICA in treatment-seeking gamblers, and it suggests that stage of change may have an impact on outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

能源岛余热锅炉的实验研究

能源岛余热锅炉是能源岛系统中的关键设备,其结构、性能和参数都极大地影响到其它设备和整个系统的性能,因此有必要对其热力学性能进行实验研究。本实验基于低温废热余热锅炉及蓄热技术研究实验台,对余热锅炉的性能进行实验研究。     

共生城市——郑东新区龙子湖湖心岛城市设计

生态城市是未来城市设计发展的主要方向,共生城市是生态城市理论的一个重要分支,该文希望通过对郑东新区龙子湖湖心岛城市设计的实践研究,对共生城市的实践进行一些有益地探索.     

浅析厦门岛城市空间发展

城市的空间发展是复杂的,是综合因素作用的结果。海岛因为其自身地形的原因,使其在城市空间变化中显现了具有独特的地方。基于对厦门的了解,本文浅析了厦门岛的空间发展变化,主要通过地理学因素和社会经济因素两方面进行了分析,其中以行政区划分等社会经济因素为主,补充了地形、围填海、交通等厦门岛独特的地理学因素为辅进行探究,最终总结出各因素的影响,得出城市空间的发展是自然因素和社会经济因素的相互作用协调,综合作用的结果。     

广州大学城“文化遗产漫步系统”建设的探索

“广州大学城”的前身“小谷围岛”曾有着丰富的物质和非物质文化遗产,是典型的岭南传统村落。现今,大学城仅余4条保留村,传统村落风貌大不及从前。“文化遗产漫步系统”是近年一种很好的保存和展示文化遗产的方法,笔者尝试运用此种方法,借鉴香港屏山文物径的经验,以北亭村作为试验,召集民间学术组织、社工、村民和大学生,以公众参与的方式,在广州大学城传统村落中共同策划、建设“文化遗产漫步系统”,并组织导赏,以此向大学生和本地村民普及历史文化保护思想、唤起公众对文化遗产保护的关注与重视。     

北京城市绿化与热岛效应的关系研究

采用遥感卫星影像数据结合实地同步测定的方法,对北京规划市区地面热场状况进行研究.对遥感影像进行信息提取和分类,建立北京市热岛分布图和城市绿化现状图,分析了城市热岛的分布和强度特征;进行不同类型下垫面热特性的系统测定,分析了热岛效应与城市下垫面绿化分量的关系研究了热岛的发生规律、影响因素和缓解热岛的措施.     

New Pilot Plant Studies at the Budapest Waterworks

The quality of water provided by the Budapest Waterworks should comply with the standards prescribed by the European Community. According to these provisions, on one of the major water-producing regions (Csepel Island), rows of wells of 60,000 m³/day yield have been closed recently, and in the immediate future further plants would have been closed because of the high iron and manganese content of the water.

The raw water obtained from 100 different wells will be purified by a water treatment plant of 150,000 m³/day capacity. Considering the high iron content (0.05–0.15 mg/L) and manganese content (0.05–0.2 mg/L), the raw water fails to comply with the requirements of the potable water standard.

Since 1990, over a period of three years, we conducted water purification experiments in several stages. In these, three methods of oxidizing as well as single and double layer open rapid filters were applied to oxidize the manganese (and, to a lesser extent, the water) present in dissolved form, resp., to destroy various living organisms.

In the course of the experiments, it became clear that the chlorine and chlorine + air methods are efficient in case of a small quantity of iron to be oxidized and only 20–25% of the dissolved manganese content could be oxidized.

Neither of the two methods could ensure firm management of microbiological and bacteriological characteristics. The best results were obtained by ozone oxidation, in which case the chemical oxidizing process was almost fully completed and even the chlorine-resistant living organisms could be destroyed.

On the basis of the experiments carried out, the investment program of the water treatment plant was worked out and the conditions of an international tender were compiled whose winner will be commissioned to build up the water works in the time period 1993–1996. One of the main steps of the proposed technology is the ozone treatment.     

基于信息熵的企业信息孤岛分析

从信息论中熵的概念为出发点,分析信息孤岛集成的需要,通过熵增原理揭示系统不能孤立地存在于环境中,必须与环境交换物质、能量与信息才能生成、存在与发展.     

Managing the Mismatch: Enhancing Early Literacy Progress for Children With Diverse Language and Cultural Identities in Mainstream Urban Schools in New Zealand.

Despite New Zealand's reputation in literacy instruction, a major achievement gap has been identified for minority Maori and Pacific Islands children in poor schools. An intervention through professional development of teachers modified instructional practices in beginning literacy instruction. The intervention involved 72 teachers from 12 schools who focused on children in the 1st 6 months of schools. A mixed longitudinal and cross-sectional design was used to examine the effects of the intervention on the language and literacy of 344 children across the age range of 5.0-6.0 years. The children in these schools made accelerated progress and gained higher levels of achievement across a broad band of measures compared with matched cohort groups. It is possible to raise achievement for minority children in schools serving low socioeconomic communities to near national levels. (PsycINFO Database Record (c) 2010 APA, all rights reserved)