环境响应性微胶囊及其在农业领域中应用的研究进展

在传统农业中,如何高效率地使用农药,提高其利用率,一直是一大难题。环境响应性微胶囊是一类在外界环境的刺激下,可以相适应地改变其表面结构的物质。这一类微胶囊具有智能、可控、精准、高效等特点。目前,这一项技术已经被广泛地应用于农业生产中。本文主要综述了环境中pH、温度、光以及磁场四大因素对响应性微胶囊的影响,并且简要介绍了该类微胶囊的制备技术、形成机理、主要材料以及在农业领域的应用。     

我国农业非点源污染研究进展及其防治措施

随着点源污染的有效控制,非点源污染已经成为我国重要污染类型之一,其中由农业产生的非点源污染又是重中之重。本文介绍了农业非点源污染的特点、研究进展及其对环境的影响,并针对不同形式的污染源提出了相应的防治措施,以便实现对农业非点源污染从源到汇的全面治理,减少农业非点源污染对水体和对人类健康的危害。     

A methodology for integrated critical spare parts and insurance management

Critical spare‐parts stock optimization has become a relevant topic for academy and industry. In most articles, the problem has been stated as a trade‐off between economic risks of shortages and financial costs. Risk optimization in this context has been mainly studied from a logistics point of view. The most common decision variables have been stock levels, stock location, and reorder points. In this context, buying insurance to cover shortage cost can be a complementary (or exclusive) measure for risk mitigation. Insurance optimization traditionally has been studied from a microeconomic and financial perspective. The main decision variable has been the indemnity function, and occasionally, the insurance premium. Its use in the context of physical asset management has not been observed to the best of our knowledge. This creates an opportunity to link inventory optimization techniques with insurance optimization for shortage losses. In this work, we present a novel approach to jointly manage the shortage risk of a critical non‐repairable component in a unique critical system. We develop an original model to integrate critical spare‐parts stock optimization with insurance optimization techniques. The result is a decision model to select the optimal stock and insurance policy that maximizes the decision maker's expected utility. This allows for a business‐centered integrated perspective in critical parts decisions. We present a case study representative of the mining industry, illustrating the complementary nature of selecting optimal stock levels and contracting an optimal insurance. Our results show that contracting an insurance can lead to policies preferred by a risk‐averse decision maker. The case study shows that this may even occur lowering stock levels and increasing profits. Copyright © 2015 John Wiley & Sons, Ltd.     

基于ARIMA模型的我国大宗农产品价格指数预测

以2006年6月至2015年12月我国大宗农产品价格指数月度时间序列作为研究对象.构建ARIMA(1,1,1)模型对我国大宗农产品价格指数进行了拟合和预测,并对模型拟合效果和预测准确度进行了检验,效果均良好.预测结果表明,从长期变化趋势看,我国大宗农产品价格指数上涨是大势所趋.从短期变化趋势看,大宗农产品面对较大的价格下行压力.     

机关事业单位基本养老保险的精算应计负债

通过养老金测算的平行四边形框架建立养老保险的精算模型应计负债,测算机关事业单位基本养老保险在2015年初的精算应计负债.提高退休年龄、利率、缴费率和工资增长率都会降低精算应计负债,退休年龄的影响非常强,利率的影响也很强.提高养老金增长率、工龄工资增长率和同年度养老金随年龄增长率都会增加精算应计负债,养老金增长率的影响很强.为控制机关事业单位基本养老保险精算应计负债,可适时适度提高退休年龄,创造条件提高投资收益率,通过全社会创新提高社会生产力来提高工资增长率,与此同时可降低缴费率.     

基于个体公平原则的寿险产品定价模型

在无套利框架的基础上,讨论基于个体公平原则下的寿险产品定价问题,即运用倒向随机微分方程理论,将投保人和保险人置于同一系统中进行考虑:首先,根据双方的随机投资决策目标分别建立无套利寿险定价模型和动态资产份额定价模型,得出两个特殊线性倒向随机微分方程的显式解;然后,建立基于个体公平原则的寿险定价模型,从投保人和保险人双方的角度对寿险产品进行公平定价,得出了从供需双方考虑的投资回报定价公式;最后,利用所建立的模型进行案例分析,计算出基于个体公平原则的保费及保险公司的投资策略.该寿险产品定价模型不仅考虑了保险人的意愿,还同时考虑了投保人的实际情况,因此,按此定价理念开发出的保险产品,不仅可以提高产品研发的成功率,而且使得研发出的新产品更能在竞争激烈的保险市场中站稳脚步.     

Polynomial diffusion models for life insurance liabilities

In this paper we study the pricing and hedging problem of a portfolio of life insurance products under the benchmark approach, where the reference market is modelled as driven by a state variable following a polynomial diffusion on a compact state space. Such a model can be used to guarantee not only the positivity of the OIS short rate and the mortality intensity, but also the possibility of approximating both pricing formula and hedging strategy of a large class of life insurance products by explicit formulas.     

Analytical method for assessing exposure of greenhouse applicators to procymidone by gas chromatography and whole body dosimetry

Summary An analytical method for the determination of the potential and actual exposure of agricultural workers to procymidone has been developed. The methodology is based on the whole body technique, using Tyvek Pro-Tech and Sontara as sampling media, and uses hexane extraction, GC-ECD analysis and GC-MSD confirmation. The validation of the analytical method has been carried out incorporating the matrix of coverall in all steps when calculating parameters such as retention time window, limits of detection and quantification, linear ranges and precision. A field sampling strategy has also been developed and the method has been applied to the evaluation of the potential and actual dermal exposure of an applicator and an assistant in normal working conditions.     

吉布斯自由能的农业应用和生物学意义

吉布斯自由能作为基本力学函数,在农业和生物学中有着重要的应用,在现代农业中,由吉布斯自由能的水势要概念,已成为判断农业系统水份动转的主要判据;在生物学中,吉布斯自由能作为生命体系赖以生存的能量,直接维持和驱动着生命体系的运转,本文讨论了吉布斯自由能的农业应用和生物学意义。     

农作物废弃物液化的实验研究

在250 mL的高压反应釜中对五种不同种类的农作物废弃物进行了液化研究。以花生壳作探索实验,重点考察了温度、时间、催化剂用量等因素对液化行为的影响,并给出了五种农作物的液化结果。研究结果表明,给料比为10 g原料/100 mL水时,在300℃～340 ℃、10 min、K2CO3添加量为1/30（催化剂/原料）的条件下,五种农作物废弃物液化获得的重油产率为21%～28%。对产物的高热值进行分析表明,农作物废弃物液化重油具有较高的热值,液化促进了能量分化,是农作物废弃物转化为生物燃料的有效手段。