解读陕西750 kV电网远景目标网架规划

结合西北电网“西水东火”的能源布局及负荷分布特点，阐述了陕西750kV电网在西北电网中的功能和定位；论述了陕西关中、陕北、陕南750kV电网建设的必要性和建设时机，从长远的发展需求考虑，勾画出了陕西750kV电网目标网架结构。     

Early hospital readmission was less likely for hemodialysis patients from facilities with longer median length of stay in the DOPPS study

The length of hospital stay is considered to influence hospital readmission in general. The Dialysis Outcomes and Practice Patterns Study (DOPPS), an international prospective observational study undertaken to establish a relationship between facility practices and dialysis outcomes, started in 1996. Results suggest that the duration of hospital stay is significantly correlated with the probability of early readmission in dialysis patients. Thus, early hospital readmission was observed to be less likely for hemodialysis patients from facilities with longer median length of stay. The lengths of hospital stay for hemodialysis patients differed in the three continents studied. Although socioeconomic pressures may drive the lengths of hospital stay, the duration of hospitalization should be determined keeping in mind the safety of clinical course for each disease. In this forum, a 47-year-old female hemodialysis patient with severe secondary hyperparathyroidism, who had been treated with hemodialysis for 21 years, was hospitalized with severe clinical symptoms. Although the clinical symptoms disappeared 10 days after total parathyroidectomy with autotransplantation, severe hypocalcemia persisted despite large amounts of intravenous calcium gluconate. This patient was hospitalized for a long duration owing to the large calcium deficit in her body. Had the length of her hospital stay been shortened, either she could have needed rehospitalization or her condition could have worsened.     

水资源可持续发展的道路

简要介绍和评价了美国环境与水资源研究所组织编写的论文集《水资源可持续的未来:预期2050年的前景》(Toward a Sustainable Water Future:Visions for 2050),该论文集由52位美国科学家合作撰写,全面分析和描述了水资源和环境学科领域在科学和工程技术两方面的发展道路,包括规划与政策、教育、科学与技术3个部分。     

确定预期瞬态恢复电压的低压模拟装置

瞬态恢复电压(TRV)是电力网络中存在的固有特性之一,是影响断路器开断性能的重要因素,因此在IEC、GB以及DL的相关标准中都对此做出了明确的规定。为了获得满足标准要求的试验回路预期参数,需要采用低压模拟的方法来测取TRV波形,因此参照相关标准中推荐的直接短路开断法、工频电流注入法、电容电流注入法等几种方法,经过分析比较,选定基于“电容电流注入法”的原理研制出了一套操作简便的低压模拟装置,使用该装置可快速实施对试验回路预期TRV波形的测取。装置研制成功后已投入课题的调试工作,进行了数百次低压模拟试验,取得了很好的预期效果。     

水凝胶的研究进展及发展新动向

水凝胶是一种具有三维网络结构的新型功能高分子材料，以其含水量高、溶胀快、柔软、具有橡胶般的粘稠性和良好的生物相容性等优点得到广泛应用及研究。本文综述了水凝胶的分类、制备及目前研究的热点，并预测了未来发展方向。     

A prospective study of cigarette smoking initiation during college: Chinese and Korean American students.

Objective: The present study was a prospective investigation of baseline influences on initial smoking and transition to established smoking among college students who had not smoked prior to college. Design: Included were 267 participants in a longitudinal study of tobacco use. Students of Chinese (52%) or Korean (48%) descent were enrolled during their freshman year in college. Data for the present study were collected during four annual in-person interviews. Main outcome measures: (1) Initial use of a cigarette reflected having first smoked a cigarette (more than a puff) during college. (2) Established smoking was defined as having smoked at least 100 cigarettes. Results: Over the course of the study, 25% of baseline never-smokers tried their first cigarette, and 9% became established smokers. Overall, men were significantly more likely to experiment and progress to established smoking. Baseline alcohol and drug use, behavioral undercontrol, and parental smoking predicted smoking experimentation but not established smoking. Students of Korean ethnicity were more likely to become established smokers. However, acculturation was not a significant predictor of experimentation or established smoking after accounting for the effects of other predictors. Conclusion: These findings suggest a need for efforts to prevent smoking uptake among Asian American college students. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

西欧电力发展回顾与展望

20年前,欧洲位于能源和电力行业的前沿。在20世纪90年代,电力充足,价格合理,欧洲成为大型工业企业的所在地,这些企业通常都是各行业的领导者和世界级的电力企业。然而今天的欧洲正在失去这一优势。与其他主要竞争国家相比,欧洲现在的电力成本更高,工业组织规模正在缩小,其电力企业也正面临困难。为何会产生这样的反转?自20世纪90年代起,建立欧洲电力市场时的“自下而上”的方法被“自上而下”的逻辑所取代。一个单一模式被应用于所有国家,欧盟委员会利用竞争与环境的手段来解决电力议题。过去20年来,在抽象及缺乏系统化的观念指导下,欧洲在碳排放、竞争力以及工业发展方面取得的成效非常令人失望。通过回顾西欧电力史,不仅能够了解这种变迁,并且能够为未来提供经验反馈。     

Focal/nonfocal cue effects in prospective memory: Monitoring difficulty or different retrieval processes?

We investigated whether focal/nonfocal effects (e.g., Einstein et al., 2005) in prospective memory (PM) are explained by cue differences in monitoring difficulty. In Experiment 1, we show that syllable cues (used in Einstein et al., 2005) are more difficult to monitor for than are word cues; however, initial-letter cues (in words) are similar in monitoring difficulty to word cues (Experiments 2a and 2b). Accordingly, in Experiments 3 and 4, we designated either an initial letter or a particular word as a PM cue in the context of a lexical decision task, a task that presumably directs attention to focal processing of words but not initial letters. We found that the nonfocal condition was more likely than the focal condition to produce costs to the lexical decision task (task interference). Furthermore, when task interference was minimal or absent, focal PM performance remained relatively high, whereas nonfocal PM performance was near floor (Experiment 4). Collectively, these results suggest that qualitatively different retrieval processes can support prospective remembering for focal versus nonfocal cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The cognitive processes underlying event-based prospective memory in school-age children and young adults: A formal model-based study.

Fifty children 7 years of age (29 girls, 21 boys), 53 children 10 years of age (29 girls, 24 boys), and 36 young adults (19 women, 17 men) performed a computerized event-based prospective memory task. All 3 groups differed significantly in prospective memory performance, with adults showing the best performance and with 7-year-olds showing the poorest performance. We used a formal multinomial process tree model of event-based prospective memory to decompose age differences in cognitive processes that jointly contribute to prospective memory performance. The formal modeling results demonstrate that adults differed significantly from the 7-year-olds and the 10-year-olds on both the prospective component and the retrospective component of the task. The 7-year-olds and the 10-year-olds differed only in the ability to recognize prospective memory target events. The prospective memory task imposed a cost to ongoing activities in all 3 age groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

云南白牛厂银多金属矿床硫同位素组成及滇东南多金属矿找矿远景

白牛厂银多金属矿床位于滇东南多金属成矿带中部,该矿床的银、锡、铅、锌储量达到了大型-超大型规模,同时伴生丰富的分散元素。由于该矿床成因争议较大,直接制约了进一步的勘探和开发。根据新开采矿段矿石矿物的硫同位素数据,系统研究了白牛厂矿床的硫同位素组成特征。结果表明：白牛厂矿床矿石矿物的δ34S值分布范围较小,黄铁矿δ34S值为2.5‰~4.0‰,磁黄铁矿δ34S值为2.7‰~3.9‰,闪锌矿δ34S值为2.9‰~4.3‰,方铅矿δ34S值为1.5‰~2.3‰,黄铜矿δ34S值为3.4‰~4.3‰。通过与赋矿地层中硫化物及与成因密切的花岗岩体的δ34S值进行对比,显示出白牛厂矿床的硫主要由岩浆作用提供,为岩浆热液型矿床。结合个旧和都龙多金属矿床的地质研究成果进一步分析认为,在滇东南地区围绕晚白垩世花岗岩体及外缘为寻找多金属矿产的有利地段。