D-1,2,4-丁三醇的绿色合成

D-1,2,4-丁三醇(D-1,2,4-butanetriol,BT)是四碳的手性多羟基醇,同时也是极具价值的有机合成中间体,应用十分广泛,特别是在医药和军事工业领域。目前D-1,2,4-丁三醇的工业化生产仍以化学合成法为主,该方法存在反应条件苛刻、产率低、副产物多,易引发环境污染等弊端。目前,利用合成生物学技术,安全高效的生物合成该化学品成为研究的热点。本文评述了D-1,2,4-丁三醇的化学合成和生物合成,以期为D-1,2,4-丁三醇的绿色合成提供理论基础。     

A dynamic product quality evaluation based pricing model for perishable food supply chains

Waste stemmed from inappropriate quality control and excessive inventories is a major challenge for perishable food management in grocery retail chains. Improvement of visibility and traceability in food supply chains facilitated by tracking and tracing technologies has great potential to improve operations efficiency. This research aims to reduce food spoilage waste and maximise food retailer's profit through a pricing approach based on dynamically identified food shelf life. The proposed model is evaluated through different pricing policies to exploit the benefits from utilising accurate product shelf life information captured through innovated tracking and monitoring technologies. Numerical analysis is conducted in an illustrative case study.     

The influence of acculturation level and family relationships on quality of life among U.S. Chinese older adults

ABSTRACT

The present study examined the influence of acculturation level and family relationships (i.e., positive family support and negative family strain) on quality of life (QOL), using the data from the Population Study of ChINese Elderly (PINE) in Chicago (N = 3159). Controlling for sociodemographic variables and health status, it was found that individuals’ acculturation level and positive family support were positively related to QOL, whereas negative family strain was negatively associated with QOL. More importantly, higher acculturation levels were associated with increased protective effects of positive family support and reduced risk effects of negative family strain on QOL among U.S. Chinese older adults.     

增强意识形态主导权的哲学思考

意识形态的话语权、领导权和主导权是逐层递进的,最高层级的主导权是依靠意识形态自身魅力维持的.社会主义意识形态主导权的根本任务是实现广大无产阶级利益,它所要维护的和实际维护的利益是一致的,这和阶级社会"虚假"的观念体系有本质区别.维持意识形态的主导权,就要不断实现人民群众的根本利益,还要强化宣传教育,坚守意识形态阵地,让先进的科学理论武装群众.     

高校教师信息素养评价体系研究

本文将在综合分析信息素养的发展历程和研究进展基础上深入探讨高校教师信息素养评价体系的现实课题,并期望未来研究采用实证定量研究对其信度和效度进行验证。     

论竞争条件下多销售渠道并存的航空货运舱位控制问题

在航空货运市场竞争日趋激烈的环境下，基于竞争的收益管理问题已经成为管理科学界的研究热点之一。针对竞争条件下的两个航空货运公司两个舱位的容量控制问题，利用博弈论的方法，建立了代理市场和现货市场并存时两公司两子舱的水平竞争的三方博弈模型，并详细分析了在 Stackelberg博弈中货运代理商的最优订购决策以及两个航空货运公司在 Cournot 博弈中的最优反应函数的性质。结果表明：如果在位者不在代理市场上销售运力，那么进入者也绝对不会提供代理市场的舱位，也就是说，如果在位者没有动力提供代理市场的运力，则代理市场将不会存在。     

新型城镇化背景下产城人融合的模式探索——以佛山为例

本文从国内外新型城镇化发展趋势及背景着手,以制造业名城佛山为例,分析历年来佛山城市定位和产城人融合战略的演进,并在实践中探索"1+2+5+X"城市组团模式下人与自然生态、文化科技和谐酿成的三湖模式、佛山新城模式等成功做法,揭示了产城人融合的科学选择。     

Tapping into English Language Learners' (ELLs') Prior Knowledge in Social Studies Instruction

Second language research and Culturally Relevant Pedagogy have shown a consensus that ELLs who have studied social studies in their home countries will have a better chance of understanding social studies concepts and quickly catching up to their native English-speaking peers. This article discusses strategies to make good use of ELLs' prior knowledge, native language and culture, and previous literacy to teach social studies concepts meaningfully and effectively to this group of students.     

Co-Occurring Psychosocial Problems and Multiple Sexual Partners among Men Who Have Sex with Men in Shanghai,China: A Syndemic Approach

We aimed to apply syndemic theory to verify the association and reinforcing effects between psychosocial problems and multiple sexual partners (MSP) of men who have sex with men (MSM) in Shanghai, China. A cross-sectional study was conducted among 547 MSM in Shanghai, China using a face-to-face survey. Sociodemographic and psychosocial data were collected, as well as information on MSP and condomless anal sex. In the 6 months prior to the survey, 54.3% of the MSM sample had had MSP. Univariate analysis showed that self-esteem, depression, loneliness, sexual compulsivity, and involuntary subordination (IS) were associated with MSP. Sexual compulsivity (multivariate odds ratio [ORm] = 2.94, 95% CI = 1.76–4.91) and IS (ORm = 1.79, 95% CI = 1.14–2.81) remained significant in multivariate analysis. MSM with five or more psychosocial problems had greater odds of (adjusted odds ratios = 3.06, 95% CI = 1.49–6.25) having MSP in the previous 6 months than the non-syndemic group. Our findings provide preliminary confirmation of the additive relationship of syndemic psychosocial health conditions and MSP among MSM in Shanghai, China. An integrated intervention with special focus on sexual compulsivity and IS is needed.     

Dimension reduction via local rank regression

Outer product of gradients (OPG) achieves dimension reduction via estimating the gradients of the regression function. In this paper, we propose two novel OPG estimators via local rank regression: the rank OPG estimator and the Walsh-average OPG estimator. Both proposals guard against a wide range of error distributions, and are safe alternatives to existing OPG estimators based on local linear regression or local L1 regression. The effectiveness of the new proposals are demonstrated via extensive numerical studies.