目标价格政策前后国内棉花期货市场波动特征分析——基于ARCH族模型

目标价格机制给棉花期货市场带来的政策效应是期货投资者和政策制定者密切关注的问题.选取CF401、CF501期货合约作为政策实施前后的对比序列,运用基于GED和Normal的ARCH族模型进行实证分析,结果表明:目标价格政策实施后,期货市场活跃度增强,投资者投资意愿增强,与现货市场联动性增强;同时,波动集群效应更显著,不存在高风险高报酬特征,价格收益率波动呈现非对成型,目标价格机制的政策效应基本发挥.最后,针对完善期货市场提出相应建议.     

两因素HJM模型下奇异债券期货期权的定价

在HJM模型下考虑远期利率由两个独立的布朗运动驱动,利用鞅方法得到了三种奇异的债券期货期权—上限型期货期权,抵付型期货期权与后定选择期货期权的定价公式。     

A note on multiple life premiums for dependent lifetimes

We study the properties of multiple life annuity and insurance premiums for general symmetric and survival statuses in the case when the joint distribution of future lifetimes has a dependence structure belonging to some nonparametric neighbourhood of independence. The size of the neighbourhood is controlled by a single parameter, which enables us to model really weak as well as stronger dependencies. We provide bounds on the difference of multiple life premiums for vectors of dependent and independent future lifetimes with the same univariate marginal distributions. Each such upper bound can be treated as a premium loading related to the strength of lifetimes’ dependence.     

Unraveling supersymmetry at future colliders

After a quick review of the current limits on sparticle masses, we outline the prospects for their discovery at future colliders. We then proceed to discuss how precision measurements of sparticle masses can provide information about how SM superpartners acquire their masses. Finally, we examine how we can proceed to establish whether or not any new physics discovered in the future is supersymmetry, and describe how we might zero in on the framework of SUSY breaking. In this connection, we review sparticle mass measurements at future colliders, and point out that some capabilities of experiments ate ⁺ e ⁻ linear colliders may have been over-stated in the literature.     

Future pricing through homogeneous semi‐Markov processes

An Erratum for this article has been published in Applied Stochastic Models in Business and Industry 2005; (in press) This paper presents a future pricing model based on the discrete time homogeneous semi‐Markov process (DTHSMP). The model is adapted to the real data of the Italian primary future stock index. After showing the pricing model, the DTHSMP solution is given. The solution of the semi‐Markov process gives, for each period of the considered horizon time, and for each starting state, the probability distribution of the future price. Copyright © 2005 John Wiley & Sons, Ltd.     

摩擦学的进展与展望

对摩擦学近１０多年来在润滑与润滑剂和摩擦与磨损两个方面的进展作了综合介绍与评述，指出最引人注目的是采用扫描隧道显微镜、原子力显微镜和超薄膜干涉仪等先进仪器设备对边界润滑和边界膜进行原位研究，以及纳米摩擦学、陶瓷摩擦学、空间摩擦学、核反应系统摩擦学、微观摩擦学和表面工程等的发展与各种新型摩擦学材料的开发。同时，还对本世纪末和下世纪初摩擦学的发展前景作了展望，认为在摩擦学设计、新的摩擦学系统、特殊的摩     

Search for heavy Majorana neutrinos at future lepton colliders

A nonzero neutrino mass may be a sign of new physics beyond the standard model (SM). To explain the small neutrino mass, we can extend the SM using right-handed Majorana neutrinos in a low-scale seesaw mechanism, and the CP violation effect can be induced due to the CP phase in the interference of heavy Majorana neutrinos. The existence of heavy Majorana neutrinos may lead to lepton number violation processes, which can be used to search for the signals of heavy Majorana neutrinos. In this paper, we focus on the CP violation effect related to two generations of heavy Majorana neutrinos at \begin{document}$ 15 $\end{document} GeV \begin{document}$ <m_{N_1}< 70 $\end{document} GeV in the pair production of W bosons and rare decays. It is valuable to investigate Majorana neutrino production signals and the related CP violation effects in rare W boson decays at future lepton colliders.     

催化水解反应的肽基模拟酶的活性来源、催化机理及应用

肽基材料由于其与蛋白质高度相似和结构可控等优势,是构建人工模拟酶的一种理想材料;此外,小肽中氨基酸排列的多样性、序列的自组装特性、纳米结构稳定性、结构简单易于设计、良好生物相容性等优势,使得构建具有高效催化活性的肽基模拟酶具有非常好的应用前景。利用肽基材料通过理性设计活性位点来构建模拟酶具有多方面优势:(1) 氨基酸序列可以直接从天然酶中的活性位点获得,保留酶的功能,但降低了酶固有的复杂性;(2) 肽序列中可以嵌入各种具有特定结构及功能的活性位点,便于对模拟酶进行人工理性设计;(3) 肽具有良好的生物相容性,可以在温和条件下催化反应进行。根据催化降解化学键的不同,可将肽基水解模拟酶分为以下几种:催化酯键降解的肽基模拟酶、催化肽键降解肽基模拟酶、催化糖苷键水解的肽基模拟酶。本文主要分析了具有水解酶活性的肽基模拟酶的活性来源、构建方法及微观结构、催化反应类型、催化影响因素、活性改善方法、作用机理及未来潜在应用等;以期为构建具有高效水解催化活性的模拟酶提供借鉴,推进肽基水解模拟酶的研究发展及实际应用。     

飞翼概念设计的广义参数定义及其性能验算

提出基于飞机传统部件设计参数的广义参数概念,描述未来飞行器概念外形,并通过初步的性能验算公式体系验证其合理、有效性。外形广义参数的探讨是为实现未来飞行器概念外形创新设计进行的一种有益尝试。以飞翼布局在民用运输机中的应用为例,在巡航马赫为0.85的设计点下,采用广义参数设计体系进行飞翼布局外形概念设计,在概念设计中实现广义参数定义飞翼外形,完成飞翼的初步选型。对该外形在应用中的性能结果进行分析,着重体现升阻比及容积率两项重要性能指标,方案设计中,在容积率损失相对不大的情况下实现了飞翼的高升阻比。     

The Future of Carica papaya Leaf Extract as an Herbal Medicine Product

Carica papaya (papaya) leaf extract has been used for a long time in a traditional medicine to treat fever in some infectious diseases such as dengue, malaria, and chikungunya. The development of science and technology has subsequently made it possible to provide evidence that this plant is not only beneficial as an informal medication, but also that it has scientifically proven pharmacological and toxicological activities, which have led to its formal usage in professional health care systems. The development of formulations for use in nutraceuticals and cosmeceuticals has caused this product to be more valuable nowadays. The use of good manufacturing practice (GMP) standards, along with the ease of registering this product facilitated by policies of the national government, will absolutely increase the value of papaya leaf extract as a vital nutraceutical and cosmeceutical products in the near future. In this article, we review the potential of papaya leaf extract to be a high-value commodity in terms of its health effects as well as its industrial benefits.