China feels the heat: negative impacts of high temperatures on China's rice sector

We analysed a county‐level data set of single‐season rice yield and daily weather outcomes in China to examine the effects of temperature on China's rice sector. We found that rice yield exhibited highly nonlinear responses to temperature changes: rice yield increased with temperature up to 28°C and decreased sharply with higher temperatures. Holding current growing seasons and regions constant, average rice yield in China is projected to decrease by 10–19 per cent by 2050 and 11–33 per cent by 2070 due to future warming under the global climate models HadGEM2‐ES and NorESM1‐M. These results imply that future warming poses a major challenge for Chinese rice farmers and that the effectiveness of adaptations will depend on how well they reduce the negative temperature impacts on rice yield because of very hot days.     

石化产品的结构优化模型

石化产品及主要原料－原油的价格变化速度较快，这就要求企业根据市场变化及时进行产品结构调整。结合一个具有代表性的石化企业实际，运用优化方法，以原油加工量、产品收率为主要指标进行石化产品结构优化，为企业生产决策提供可靠的依据。     

证券市场成交量对收益率波动性影响的实证分析

本文根据上海证券市场上证综合指数2005年1月1日到2006年1月1日的复合收益率和日成交量。用GARCC模型描述日成交量对复合收益率的波动性影响。在GARCH模型中加入当期交易量、滞后一期的交易量，结果表明当期交易量变化率能明显削弱收益率条件方差的波动性，而滞后一期的成交量只通过对当期的成交量间接的影响复合收益率。     

On the determinants of yield spreads between mortgage pass-through and Treasury securities

Yield spreads between mortgage pass-through and U.S. Treasury securities may reflect differences in taxation, phenomena affecting relative supply and demand, and compensation for default, call, and marketability risks on mortgage instruments. Our research empirically models differences in yields between pass-throughs and comparable-maturity Treasuries. We find that interest-rate volatility and the term structure of rates, factors often cited in the mortgage pricing literature as affecting the mortgage call premium, are the primary determinants of movements in these spreads. Moreover, these effects have grown in importance in recent years as exercise of the prepayment option has increased. We also find evidence that liquidity and credit concerns affect the pricing of pass-through securities.     

The Gilt-Equity Yield Ratio and the Predictability of UK and US Equity Returns

A number of financial variables have been shown to be effective in explaining the time-series of aggregate equity returns in both the UK and the US. These include, inter alia , the equity dividend yield, the spread between the yields on long and short government bonds, and the lagged equity return. Recently, however, the ratio between the long government bond yield and the equity dividend yield – the gilt-equity yield ratio – has emerged as a variable that has considerable explanatory power for UK equity returns. This paper compares the predictive ability of the gilt-equity yield ratio with these other variables for UK and US equity returns, providing evidence on both in-sample and out-of-sample performance. For UK monthly returns, it is shown that while the dividend yield has substantial in-sample explanatory power, this is not matched by out-of sample forecast accuracy. The gilt-equity yield ratio, in contrast, performs well both in-sample and out-of-sample. Although the predictability of US monthly equity returns is much lower than for the UK, a similar result emerges, with the gilt-equity yield ratio dominating the other variables in terms of both in-sample explanatory power and out-of-sample forecast performance. The gilt-equity yield ratio is also shown to have substantial predictive ability for long horizon returns.     

西宁市建筑施工垃圾的管理及对策研究

近年来我国建筑业发展迅速,西宁市城市化进程导致新建、改建、扩建、拆除工程随处可见,因而在施工阶段产生大量的建筑施工垃圾。如果对这些垃圾不进行有效分析和管理,产量加剧会更加严重,对环境污染也会更严重。本文针对西宁建筑施工垃圾管理现状,提出相对应的有效对策。     

Interest Rates and Credit Risk

This paper explores the effects of shifts in interest rates on corporate leverage and default in the context of a dynamic model in which the link between leverage and default risk comes from the lower incentives of overindebted entrepreneurs to guarantee firm survival. The need to finance new investment pushes firms' leverage ratio above some state‐contingent target toward which firms gradually adjust through earnings retention. The response to interest rate rises and cuts is both asymmetric and heterogeneously distributed across firms. Our results help rationalize some of the evidence regarding the risk‐taking channel of monetary policy.     

气候变化对粮食产量影响的研究方法综述

[目的]受气候变化的影响,全球粮食安全面临严峻挑战,及时准确地评估气候变化对粮食产量的影响是应对挑战、制定农业适应性对策的关键。相关研究已产生了不少方法,通过综述对方法进行分类,明晰各种方法的优缺点和适用性,以期扬长避短,促进研究方法的综合、发展与完善。[方法]利用文献法、归纳法和比较法,从方法的原理和应用、存在的问题、发展的趋势3个方面进行探讨。[结果]产量分解法可用于分析粮食产量及其构成要素与不同生育期气候变化的关系,实验比较法一般用于粮食产量对单个气候因子或若干气候因子变化的敏感性分析,生产函数法适用于在农业生产系统中分析气候变化对粮食产量影响的边际效应,气候生产潜力模型法侧重于农业生产环境发展评估,作物生长模型法便于结合气候情景预测未来气候变化对粮食产量的影响。在不同研究方向上得以运用的同时,各方法也暴露了一些问题:产量分解法的技术产量难以拟合,实验比较法的数据获取难、模型稳定性较差,生产函数法容易遗漏重要变量、函数构造困难,气候生产潜力模型法的结论难以验证,作物生长模型法参数标定难、模型应用存在尺度错位。[结论]研究方法将逐渐形成一套综合的气候—水文—作物—经济模型法,多源数据融合和多目标模式已经成为方法发展的驱动力。     

特种高收益风险债券──风险投资的金融创新

风险投资是指投资者以获得红利或出售股权获利为目的，出资协助具有专门技术而无自由资金的企业或个人实现创业，承担创业阶段的失败风险并将回收资金循环投入高风险事业。但是，由于种种投资类型所固有的特征，它所涵盖的投资主体和投资对象都会受到一定的限制。因此，设计一种特种高收益风险债券，这种债券能够弥补传统风险投资的缺陷，吸引更多业绩良好的中小企业或是具有特殊性的行业及企业进入风险投资领域，成为高科技企业融资的新选择。     

新疆农村土地整治的特点和对策

新疆以其独特的地理区位、重要的战略地位和丰富的自然资源禀赋成为我国土地整治的重点地区和国家土地整治重大项目工程的实施地区。2001年以来,新疆累计投入资金50×108元,实施土地开发整治项目292个,新增耕地面积7.15×104hm2。要结合新疆土地利用,树立环保优先、生态立区的理念,坚持走资源开发可持续、生态环境可持续的道路,以改善民生为目标,围绕高标准基本农田建设、安居富民、定居兴牧等民生工程,积极探索有效利用土地资源的新机制,扎实有效推进新疆土地整治工作。