利用遥控心率仪器对女大学生减肥的实验研究

肥胖是常见病,对人类的危害很大。肥胖的治疗应该是综合治疗,运动减肥已经引起人们足够的重视,但实际上科学的减肥方式并没有为大多数人所认识。本文利用遥控心率仪器进行实验,通过选择不同的运动方法对减肥者进行有效的心率控制。运用问卷调查和实验的方法,使受试者达到较好的减肥效果。利用遥控心率进行减肥是科学的、合理的,适宜的运动心率是减肥的较好手段。     

城市生活垃圾气化特性及动力学研究

采用热重分析仪,分别对我国城市生活垃圾典型有机物(厨余、废纸和废塑料)及其混合物(MMSW)非等温气化特性进行了研究。通过改变加热终温和升温速率,获得了厨余、纸类、塑料及其混合物TG-DTG曲线,并采用Coats-Redfern积分法和外推法对曲线进行了动力学分析。试验表明,加热终温是影响气化失重的主要因素;改变升温速率会造成失重率的波动,并对气化反应初始温度有显著影响。当CO2替代N2作载气时,两者作用明显增强;同时由于C+CO2→2CO反应增强,使MMSW表现出明显与N2气氛下不同的特性。动力学分析表明城市生活垃圾典型有机物及其混合物气化反应为一级。     

期货套保基金服务中国农业的模式探讨

期货市场在规避农产品市场价格风险方面具有重要作用。文章从中国农业的实际出发,分析现有农产品期货服务农业模式存在的局限和不足,提出了农产品期货套保基金新模式。重点探讨了套保基金设立的方式、运作流程,分析其有利因素和制约因素,并提出了相应对策。     

基于能量消耗分析的乳状液液滴粒径计算关系式

在油水混输管道中,存在着大量粒径大小不一的乳状液液滴,液滴粒径及分布对油水混合液的粘度有重要影响,从而在很大程度上影响管道的压降。因此,研究乳状液液滴粒径的计算关系式对于描述油水两相的流动特性以及准确计算管道压降具有重要意义。针对4种原油,通过油水体系的乳化实验,研究了搅拌转速、温度及含水率对乳状液液滴粒径的影响。研究发现,搅拌转速增大,乳状液液滴粒径减小;温度升高,乳状液液滴粒径增大,并且在低温下增大的趋势较显著;含水率增加,乳状液液滴粒径有减小趋势,但减小的幅度不大;以火用损率来表征剪切过程中的能量消耗,建立了基于剪切火用损率分析的乳状液液滴粒径计算关系式。     

Relative uncertainty aversion and additively representable set rankings

This paper proposes a definition of relative uncertainty aversion for decision models under complete uncertainty. It is shown that, for a large class of decision rules characterized by a set of plausible axioms, the new criterion yields a complete ranking of those rules with respect to the relative degree of uncertainty aversion they represent. In addition, we address a combinatorial question that arises in this context, and we examine conditions for the additive representability of our rules.     

CONSTANT PROPORTION PORTFOLIO INSURANCE IN THE PRESENCE OF JUMPS IN ASSET PRICES

Constant proportion portfolio insurance (CPPI) allows an investor to limit downside risk while retaining some upside potential by maintaining an exposure to risky assets equal to a constant multiple of the cushion , the difference between the current portfolio value and the guaranteed amount. Whereas in diffusion models with continuous trading, this strategy has no downside risk, in real markets this risk is nonnegligible and grows with the multiplier value. We study the behavior of CPPI strategies in models where the price of the underlying portfolio may experience downward jumps. Our framework leads to analytically tractable expressions for the probability of hitting the floor, the expected loss, and the distribution of losses. This allows to measure the gap risk but also leads to a criterion for adjusting the multiplier based on the investor's risk aversion. Finally, we study the problem of hedging the downside risk of a CPPI strategy using options. The results are applied to a jump-diffusion model with parameters estimated from returns series of various assets and indices.     

电力系统线路电压降与电压损失的精确表达式

以电力系统线路的向量图为基础,分别导出了线路的电压降和电压损失的精确表达式。     

International tourism demand and the business cycle

The focus of this study is on presenting causes and hypotheses for the existence of asymmetric income and price effects on tourism demand across business cycles. The theoretical assumptions were tested by analyzing tourism import demand in different source markets, drawing on econometric models that provide for the magnitudes of price and income effects either to vary depending on the phase of the business cycle or to remain stable across the business cycles. The major outcome of this study is that the general assumption in most of the tourism demand studies—i.e. that the income effects are symmetric—should not be expected to be automatically true for every source market.