无风险投资对有效边界与有效投资组合的影响

以允许卖空的风险证券组合投资有效边界、有效集研究为基础，分析了无风险投资的引入对风险证券组合投资有效边界，有效集的影响，并给出了无风险投资与风险组合投资再组合的有效边界，有效集等若干数学结果。     

一类风险资产组合模型的分析

资产投资是当今市场经济的主要内容之一,投资者面对的往往不只一种资产,各种资产都具有其自身的特性,具体表现为收益率、风险损失率、交易费率等等。投资的目的就是要获得收益,而收益一般和风险相伴存在,不同的投资项目有不同的收益和风险。风险投资的出现给资本市场带来了全新的理念,风险越大收益越高。在这样的背景下,考虑到投资越分散,总的风险越小,同时为了保证收益的最大化,投资者必须考虑在多种资产的组合方案中选择一个适合自己的有效的投资组合方案。     

第四讲 证券投资策略与方法（一）

证券投资的基本方法证券投资的最终目的是为了获取利益,而收益的大小始终与风险并存.由于各种证券的风险中既有不可分散的风险,也有可分散的风险,因此投资者不应把资金全部投资于一种证券上,而应选择风险相关程度较低的多种证券,组成证券组合、在形成证券组合时,投资者通常可采用两种投资的基本方法.一是收入到投资法,一是增长型投资法.     

风险投资预测-决策模型与风险定价机制研究

立足于风险投资全过程,发现了风险投资的金融行为特征,明确了当风险投资主体高度理性时,外部市场不确定和投融资主体之间信息不确定并不是绝对的外生;借助数学模型,论证了风险投资预测过程的实质是将风险内部化．风险投资主体充分运用其投资优势,对投资目标的可行性、不确定性和收益性等方面进行事先“定性”考察、分析与判断,使投融资过程中的风险内部化．在预测的基础上,风险投资主体根据所拥有的投资优势、掌握的经验数据与未来信息,运用动态连续判断策略,获得“定量”风险收益优化组合决策,而不是传统地降低风险．最优风险收益组合决策与无预测决策的收益差值,即风险外溢与创新外溢的估值,体现了风险投资作为内部驱动的经济意义．      

多期投资组合问题的优化分析

根据实践中风险分散的要求,在多期投资组合问题中加入资产分散约束,建立了该问题的随机规划模型,并将其转化为两阶段有补偿模型.然后将资产虚拟为局中人,构造了一个合作博弈问题.利用随机规划的对偶理论证明了该合作博弈存在核心分配,结论显示将初始资金投资到全部资产上的多期投资组合,其收益优于分散初始资金、分散资产组合的投资方法.     

谈风险投资项目投资后管理

风险投资项目的投资后管理,是风险投资机构及风险投资项目管理人员以提高风险企业的管理能力为核心,通过提供增值服务,帮助解决其存在的问题,促进其快速成长升值,选择最佳时机,以股权转让方式实现投资退出变现增值的过程。依“法”施管。风险投资机构依据与风险企业之间的投资协议等具有法律约束力的契约而对风险企业实施的监督和管理。投资协议是风险投资后管理的起点,是风险投资机构实施投资后管理的依据和基础。投资协议中作为风险投资机构实施监管依据的内容包括关于风险企业董事会组建调整条款、风险投资机构有权检查风险企业所有信息…     

风险投资最优组合

在理论上投资与风险的最优组合为投资的类型越分散,所承担的总风险越小,最低风险和最高收益二者是不可以兼得的.讨论了在一定范围内如何科学地把投资种类进行组合,才会使得收益和风险达到一个最优的状态.     

我国风险投资体系研究

 风险投资,是指风险投资组织通过一定的途径和方式向机构或者个人筹集风险资本,然后将所筹集资本投入风险企业（或项目）,并以一定的方式参与管理,期望通过出售股权最终获得高额回报的一种商业投资行为。风险投资主体主要包括：风险资本供给方（投资者）、风险资本运作方（风险投资组织）与风险资本需求方（风险企业）。其中风险投资组织是沟通投资者与风险企业的纽带,风险投资组织按市场运作规律,将风险企业置于市场竞争中,通过参与管理和市场评价,使风险企业向股票市场的方向逼近,以实现高收益的投资期望。风险投资体系由风险资本的供给体系、风险资本的组织体系、风险资本的需求体系和风险资本的退出体系４个方面构成。     

房地产投资组合风险分散策略

基于现代投资组合理论,探讨了房地产投资组合风险管理中,按照物业类型与按照地理区域分散投资风险的选择问题。利用Jennrich相关检验和有效边界方法,对北京、上海、广州和深圳四城市的住宅市场与写字楼市场进行的实证分析表明:按照物业类型与按照地理区域构建房地产投资组合都可以有效的分散投资风险;但是,与在同一地理区域中按照不同物业类型构建投资组合的策略相比,在同一物业类型中按照不同地理区域进行房地产投资是更好的风险分散效果。     

基于投资组合理论的房地产投资组合决策模型

现代投资组合理论具有分散风险、稳定收益的作用,被广泛地应用于房地产投资实践中。本文引入风险系数γp,以单位收益下风险最小为目标建立房地产投资组合决策模型,并用不可分散度量系数β将单项房地产投资的总风险分解为系统风险和非系统风险,进一步完善该模型,克服了传统决策方法的缺陷和不足,从理论角度解决了投资者的资金分配问题,以实现风险和收益的最佳组合。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with