信息服务模式及网络利用

当今的用户获取信息的渠道越来越广,这使得信息服务面临着多方面的竞争。对于从事信息服务的工作者而言,如何让信息真正有效地服务于各行各业和广大用户,以及依据什么因素来选择恰当的服务模式与推动模式的更新都是非常重要的。文章初步探讨了信息服务模式的变化,以及网络在信息服务中的利用。     

影子价格两种定义的统一性及其经济学含义

通过应用库恩-塔克定理,本文论证了线性规划对偶解和一般数学规划的拉格朗日乘子这两种影子价格定义的统一性。由于非线性规划比线性规划更具有普遍性,本文的结论为深入讨论影子价格的经济学意义提供了极大方便。完全竞争是影子价格等于机会成本和市场价格的充分条件。但在不完全竞争条件下,影子价格一般不等于机会成本和市场价格,也不代表资源的最优配置价格,它反映的只是企业的资源利用效率。     

Understanding the Large Negative Impact of Oil Shocks

This paper offers a plausible explanation for the close link between oil prices and aggregate macroeconomic performance in the 1970s. Although this link has been well documented in the empirical literature, standard economic models are not able to replicate this link when actual oil prices are used to simulate the models. In particular, standard models cannot explain the depth of the recession in 1974–75 and the strong revival in 1976–78 based on the oil price movements in that period. This paper argues that a missing multiplier-accelerator mechanism from standard models may hold the key.     

Valuing Food Store Access: Policy Implications for the Food Stamp Program

Food stamp recipients may lack access to larger stores, reducing the availability of nutritious food. Reliance on smaller stores may have undesirable impacts. Policy alternatives include limiting food stamp redemption to larger stores and subsidizing store development. I estimate that limiting redemption to supermarkets and grocery stores, or supermarkets alone, results in losses ranging from $499.2 million to $1.05 billion, or $1.17 billion to $2.44 billion (respectively) annual loss in food stamp recipient welfare nationwide. The impact of improving access is also significant, ranging from $333.6 million to $931.2 million.     

The Nested PIGLOG Model: An Application to U.S. Food Demand

A new demand system is introduced, the Nested PIGLOG model, nesting thirteen other demand systems including five that are also new. This new model and its nested special cases are applied to models of U.S. food demand that include food-at-home (FAH), food-away-from-home (FAFH), and alcoholic beverages. Although nested tests and out-of-sample forecasting performance favor generalizing models to a certain degree, statistically insignificant improvements to in-sample-fit and even poorer out-of-sample forecast accuracy undermine further generalizations. Based on a subset of preferred models, FAFH is found to be price and income elastic compared to FAH which is price and income inelastic.     

农村居民食物消费的可持续发展

农村居民食物消费的可持续发展不仅决定着农村居民的健康水平 ,还决定着农村居民食物消费的可持续性。通过对我国农村居民食物消费的合理性分析 ,提出了农村居民食物消费的合理选择和可持续发展对策。     

小氮肥清洁生产实践

文章介绍了沅江市氮肥厂废水闭路循环、尾气回收、废渣综合利用等工程,并介绍了该厂的生产工艺、污染源分布及排污特点。     

生鲜加工配送中心生鲜食品及加工食品检验和退货流程

生鲜加工配送中心的生鲜商品检验、退货流程对确保生鲜商品的安全有着十分重要的作用，本文着重针对生鲜加工配送中心蔬菜及加工食品检验和退货作业流程进行了研究。     

湿地公路与农田水利建设关系分析

湿地因其特殊的自然状况，公路交通建设投资大，成绩显著，但农田水利设施损失严重，正确处理好湿地公路建设与农田水利建设的矛盾，有利于发展交通建设和解决三农问题。文章从公路交通与农田水利现状分析出发，试图找到湿地交通发展与农田水利建设的平衡点，形成公路建设，农田水利建设共同发展的良好循环。     

国外食品冷藏供应链发展概况

着重介绍了国外冷藏链的发展历程以及在现代冷藏技术方面所取得的成就和最新发展趋势。