1-二茂铁基乙醇的制备及结构表征

采用NaBH4/CaC12的还原体系将乙酰基二茂铁还原为1-二茂铁基乙醇。探讨NaBH4、CaC12的用量及反应时间对还原产物收率的影响,得到将乙酰基二茂铁还原的较为理想条件:甲醇为溶剂,投料按FcCOCH3:NaBH4:CaC12=1:3:2,碱性条件下回流1.5 h,1-二茂铁基乙醇的收率达87.5%。     

Communication in the management of uncertainty: The case of persons living with HIV or AIDS

Communication is a means of managing uncertainty. In a state of uncertainty: (a) information seeking can reduce uncertainty by allowing for better discrimination between or among alternatives; (b) information seeking can increase uncertainty by increasing the number of alternatives, or by blurring the distinction between or among alternatives; and (c) information avoidance can maintain uncertainty. Individuals living with HIV or AIDS, like many other chronically‐ill or terminally‐ill individuals, must manage high levels of uncertainty about their illness. Participants in a focus group study of persons with HIV or AIDS reported effective uncertainty management, including managing uncertainty that was challenging, managing uncertainty that was essential for maintaining hope, learning to live with chronic uncertainty, and managing information problems. New information can serve uncertainty management even if it fails to reduce the number or ambiguity of alternatives, because new information can invite a reappraisal of uncertainty. A theory of uncertainty management based on these findings is offered.     

Predicted Outcome Value Theory in Ongoing Relationships

Theory and research reported in this paper provide both theoretical and methodological advances in the study of predicted outcome value theory (POV) in established, ongoing relationships. From a theoretical perspective, POV, previously a theory focused solely on initial interaction behaviors and consequences, is extended into the realm of ongoing relationships. The propositions of the theory are reformulated and hypotheses derived from them are tested. Overall, the results strongly support this extension and shed new light on its role in understanding the effect of unexpected events. Methodologically, the study provides a longitudinal approach for assessing ongoing relationships both before and after the occurrence of an unexpected event.     

Teachers’ workplace and professional certainty

The study focuses on teachers’ perceived certainty, a concept which is understood as being made up of didactic, practical and relational certainty, and its relationship with teacher collaboration, role ambiguity and job satisfaction. Analyses draw on data from 1153 Norwegian elementary and junior high school teachers. Results indicate that there are statistically significant differences between the two subgroups of teachers concerning collaboration and job satisfaction. Furthermore, interesting differences regarding relations between collaboration and teacher certainty are found. Teachers in this study also report most collaboration on planning lessons, but little collaboration on activities one would expect to enhance self-awareness and reflection. A structural equation model involving relationships between all variables is tested and results reveal good fit indices.     

案例教学在《电力系统不确定性理论与测度》课程中的应用研究

《电力系统不确定性理论与测度》是电力专业里一门交叉型课程,根据电力系统课程的独特性,结合现有教学环境,按照课程教学目的,文章根据课程教学中出现的缺点与不足,从教学内容、教学理念和教学方式等方面进行了改革。通过引入案例教学,激发学生对电力系统不确定性理论深入了解的热情,使学生更加充分理解课程内容,同时培养学生的分析解决问题能力、工程实践能力,整体上提高学生的综合素质。     

论傻子视角的现实性平行与边缘性交叉

阿来《尘埃落定》中的“傻子”是土司制度巩固、走向瓦解的参与、思想、见证人，是作品在历史的厚重中凸显空灵的灵魂人物，他以其自我审视与历史审视的眼睛，既显示出他对土司权力的略带侥幸的患得惠失的不懈图谋，又显示出他长远瞩望不得其真的无奈，他只能无可奈何地站在广漠历史天幕下踟躇独行，矛盾重重地成了一个历史“化亡灵”的记忆。     

RSA在高性能DSP上实现的算法分析及优化

RSA是公开密码体系中应用最广泛的算法，通过对算法结构的分析，运用中国剩余定理、M-ary乘方以及Montgomery约化等方法对RSA的运算过程进行了重新设计，提出了一种减少预计算数的M-ary算法；并结合TI公司TMS320C6201高性能DSP的流水特点，对模幂运算中用到最频繁的模平方运算进行了优化，提高了计算的速度。     

无汞定铁法评述及应用——澳大利亚、巴西进口铁矿石含铁分析

本文评述了三种无汞定铁的方法,认为以SnCl_2-TiCl_3联合还原、钨酸钠或磷钨酸作还原指示剂、用重铬酸钾标准溶液滴定全铁的方法是一条有希望的无汞定铁途径,并应用于澳大利亚进口铁矿石含铁分析,结果令人满意。     

Flexibility of Suckler Cattle Farms in the Face of Uncertainty within the Beef Industry: A Proposed Definition and an Illustration

Abstract

The aim of this study, carried out in association with beef cattle producers, was to explore the capacity of farms to adapt, from a techno-conomic point of view, to both structural changes in consumer demand for beef products and market disruptions (sudden drop in beef consumption due partly to media coverage of bovine spongiform encephalopathy [BSE] and foot-and-mouth disease in the winter 2000/2001). The aim is to help farmers and advisors to find solutions to fit farmers’ management choices with their strategic objectives. The flexibility concept was adopted in order to examine how farms reacted to the winter 2000/2001 crisis, and was based on several technical, economic and sociological surveys. A series of variables was proposed and several hypotheses were formulated regarding their impact on farm flexibility. Four types of farm strategy were identified using different combinations of the degree of importance of these variables, with technical, economic and marketing flexibilities specific to each type. The results revealed the different combinations of flexibility-types possible (technical, economic, marketing) and explain why cattle farmers reacted as they did. Analysis of farm flexibility also revealed situations where these technical, economic and marketing flexibilities were either complementary or incompatible. For traditional livestock farmers, high flexibility (technical and economic) allowed them to minimize the impact of the crisis on their systems. In other cases, low flexibility either resulted in inertia, or led farmers to react by seeking solutions outside the cattle farming system. Development groups should take into account these parameters when interacting with farmers. We propose a framework to qualify the use of information resources by farmers, relative to their flexibility.     

Patterns of Social Support Communicated in Response to Expressions of Uncertainty in an Online Community of Young Adults with Cancer

In order to develop more effective ways of helping adolescents and young adult (AYA) cancer survivors cope with cancer-related uncertainty, it is important to understand how AYAs respond communicatively to each other's uncertainty. We designed this project to gain insight into the patterns of social support that occur in response to AYAs' expressions of uncertainty. We analyzed 510 responses to posts in an AYA-focused online discussion group. Eighty-two percent of messages responding to uncertainty contained informational support. Sixty-seven percent contained multiple types of support. Among medical, personal, and social sources of uncertainty, the most typical response tended to be a combination of informational support accompanied by emotional and/or esteem support. AYAs who express uncertainty in online support groups should be advised that their posts are likely to be met with information, such as advice and referrals, which may either facilitate or impede their uncertainty management goals.