干散货航运即期费率和远期费率的动态引导关系——基于不同船型运输市场的月度经验数据

利用干散货航运市场2002—2010年的月度数据,通过ECM模型对3种主要干散货船型的即期费率和远期费率之间的动态引导关系进行实证研究。结论表明：不同船型的即期运费之间、远期运费之间均不存在协整关系;同一船型的即期运费与远期运费之间存在协整关系;Capsize型船舶的即期运费引导远期运费,Panamax型船舶的即期运费和远期运费双向引导,而Handymax型船舶的远期运费引导即期运费;各类船型的即期费率和远期费率之间呈正相关关系,且船型越大,两者之间的弹性越高。     

阜新市主导产业选择问题研究

在分析了阜新市三次产业主导性,构建了以经济效益好,发展速度快;关联效应强;前景光明,优势明显;资源枯竭型城市主导产业选择特点为原则的11项指标为体系的模糊聚类数学模型,对阜新地区的主导产业选择问题作实证研究,阜新处于主导产业培育阶段,并为主导产业发展提出一些建议和意见。     

The Value of Improved National Exposure Information for Perchloroethylene (Perc): A Case Study for Dry Cleaners

Opportunities to improve our information about risk continue to arise and lead decision makers to indirectly address the issue of the value of improved information through resource allocation decisions. Statistical decision analysis techniques provide an analytical framework for valuing information explicitly in the context of regulatory decision making. This paper provides estimates of the value of improved national estimates of perchloroethylene (perc) exposure from U.S. dry cleaners in the context of EPA's recently promulgated National Emissions Standard for Hazardous Air Pollutants (NESHAP) with emphasis on exposure information. Consistent with the NESHAP decision, we relied on EPA's technology and economic assessments. In this first cut analysis, estimates of the exposures of workers, consumers of dry cleaning services, and the general public are probabilistically characterized to reflect uncertainty about exposure and potency. We consider the net benefits of the different control options by assessing the associated changes in the total annual population risks and valuing them in monetary terms, with no constraints placed on maximum individual risks. The results suggest that the expected value of perfect information (EVPI) about potency exceeds the EVPI about exposure. Sensitivity analyses demonstrate how the choices of the valuation parameters and distributions used to characterize uncertainty in the model affect the estimates of the value of information.     

晚稻旱育秧综合配套技术研究

通过五元二次回归旋转组合设计试验，明确了影响洞庭湖区晚稻生产的主要因素，依次为播种量（X1），2．1叶期喷施效唑（X4）移栽叶龄（X2），分蘖期施纯氮（X5）等，建立了五元二次目标函数模型，提出了适应洞庭湖区一季晚稻和双季晚稻的五套优化综合配套技术，探讨了二因素对产量影响显著的交互效应。     

Generalized Additive Modelling of Mixed Distribution Markov Models with Application to Melbourne's Rainfall

The paper considers the modelling of time series using a generalized additive model with first-order Markov structure and mixed transition density having a discrete component at zero and a continuous component with positive sample space. Such models have application, for example, in modelling daily occurrence and intensity of rainfall, and in modelling numbers and sizes of insurance claims. The paper shows how these methods extend the usual sinusoidal seasonal assumption in standard chain-dependent models by assuming a general smooth pattern of occurrence and intensity over time. These models can be fitted using standard statistical software. The methods of Grunwald & Jones (2000) can be used to combine these separate occurrence and intensity models into a single model for amount. The models are used to investigate the relationship between the Southern Oscillation Index and Melbourne's rainfall, illustrated with 36 years of rainfall data from Melbourne, Australia.     

粗颗粒土混合料最大干密度及压实度研究

通过表面振动与振动台两种方法进行粗颗粒混合料最大干密度测试，试验结果表明：同一种土湿土法做出的最大干密度明显要大于干土法所测的最大干密度，表面振动仪法的振密效果要优于振动台法的振密效果。通过高速铁路路基施工现场压实后路基干密度与室内最大干密度测试结果对比，发现既有路基施工工艺可以达到以表面振动法测试得到最大干密度的95%压实度。     

耕作制度发展矛盾及对策--以黄土高原为例

建国50年来,我国的耕作制度发生了翻天覆地的变化,耕作制度的改革有新的起点与突破,仅以占全世界7%的耕地养活了占全世界22%的人口,取得了举世瞩目的成就.本文根据中国近几年耕作制度合理利用自然资源和社会资源,运用各种高新技术,实现农业持续、稳定和高效的增产,使农业生产各关联部门得以协调发展的实际,阐明了耕作制度的发展趋势,探讨了耕作制度在新形势下面临的挑战,研究了耕作技术发展的对策,可供同类地区研究者参考.     

基于Copula方法的干散货运费子市场尾部相关性分析

通过分析Copula函数的尾部相关性来揭示干散货巴拿马运费市场和好望角运费市场的相关性。实证结果表明,基于时变相关的二元对称Joe-Clayton(SJC)Copula对干散货运费子市场尾部相关性的拟合效果最好,而且当市场下降时,两个子市场表现出强而剧烈的相关性;市场上升时,二者表现出弱而平稳的相关性,因此基于不同船型的航线组合投资在市场上升时的效果优于市场下降。     

焦炉煤气干法脱硫剂的研究现状与进展

评述了目前国内外用于焦炉煤气脱除硫化氢的各种干法脱硫剂的研究现状,分析了活性炭、铁系、锌系、铜系、锰系及钙系脱硫剂的脱硫原理,并指出了其在再生和脱硫效率等方面的优缺点,发现对于单一的金属氧化物脱硫剂已不能满足生产的需要,研究人员逐渐向复合金属氧化物脱硫剂进行开发研究,结果发现,复合金属氧化物在脱硫效率和再生性能方面都要优于单一的金属氧化物。     

浅谈22例干槽症的病因及预防

干槽症是指拔牙创口无血凝块复盖,发生感染,引起部分牙槽骨坏死的一种病症,是拔牙手术后较为常见的并发症。本文从病因及预防上加以分析,目的是寻找可预防的环节,以期达到减少或杜绝干槽症的发生。