延迟期权在大型基建项目风险决策中的应用

不确定性条件下,净现值法（NPV）在对基建设施项目进行价值评估时忽略了项目管理柔性特征.本文基于实物期权理论分析基建设施项目的特点,指出分阶段投资的基建设施项目中存在的延迟期权,并运用二叉树期权定价模型对其进行评价.文章通过案例分析对基建设施项目进行价值评估,对影响延迟期权的各种因素进行敏感性分析,说明运用实物期权方法进行投资决策的优越性.     

基于实物期权的PPP项目投资评价研究

传统的现金流折现法忽视了不确定性因素的影响,不能对基础设施PPP项目进行有效评价.针对传统的折现法的这一缺陷,分析了PPP项目中存在的期权特征,并提出基于实物期权理论的二叉树期权评价模型.通过实际的案例分析,考虑交通PPP项目中车流量的不确定性,得出实物期权理论相对于现金流折现法的优势.最后提出实物期权在PPP项目评价中的应用前景与建议.     

高管股权激励对R&D资本化与费用化价值相关性的调节效应

选取2007~2011年披露研发投入且数据完整的1695家上市公司为研究样本,利用层次回归分析,实证检验了高管股权激励对RD资本化与费用化价值相关性的影响作用。研究结果表明:高管股权激励不仅是RD资本化投入与股票价格的半调节变量,同时,高管股权激励也是RD费用化投入与股票价格的半调节变量;通过高管股权激励,可以解决监管RD活动中信息不对称和风险性等问题,使企业实现股东价值最大化。     

不同激励频率比下复合模态振荡的结构特性分析

研究多频激励下不同激励频率比时快慢耦合系统的各种复合模态振荡的动力特性及其产生机制.以广义BVP(Bonhoffer-van der Pol)耦合电路为例,通过引入两个电压源控制的电路模块,建立了具有双周期激励的五阶动力模型.选定适当的参数,使得两个激励频率均远小于系统的固有频率,以此考察不同激励频率比下系统的快慢动力学行为.将两个外激励项转化为一个慢变量表达形式,从而将系统分为快慢耦合两子系统.分析了快子系统的平衡点及其分岔条件,探讨了不同激励频率比对复合模态振荡结构的影响,得出系统可能产生原点中心对称,轴对称和非对称的复合模态振荡.给出了系统在6组激励频率下的不同复合模态振荡行为,并进一步揭示了其相应的产生机理.     

基于实物期权的多重不确定条件下人力资本投资决策

以个人教育投资为例,充分考虑投资成本—收益的不确定性,首次构建了多重不确定性人力资本投资的实物期权模型。结合数值释例和比较静态分析,研究了各个关键不确定性参数的变动对投资阀值的影响。结果表明:投资不确定性的增强会使个人在人力资本最优投资阀值提高时推迟离开学校;预期投资收益的增加使个人倾向于尽快就业,而投资成本的不断上升则会一定程度地增强个人"等待"的激励,使个人倾向于继续留校;无风险利率的降低会刺激个人尽早进行人力资本投资。此外,与净现值模型相比,实物期权模型充分考虑了投资的多重不确定性,故所得出的投资阀值相对更高,而对投资成本-收益的敏感度更低。     

非定常等离子激励器诱导平板边界层的流动结构

采用唯象模型模拟DBD等离子激励器,通过求解Navier-Stokes方程研究了等离子非定常激励与平板边界层的相互作用.分别考察了激励强度、激励波形和激励频率对非定常等离子体激励诱导流场结构的影响.结果表明,非定常等离子激励使边界层内形成系列涡对,其涡量沿程呈指数型衰减.涡对的强度主要由等离子的有效激励强度决定,激励频率主要是对涡的平均流向间距的影响.占空因子不太大时,相邻涡对的相互作用可以忽略,激励波形对涡对影响不大.     

表面介质阻挡纳秒脉冲放电能量特性和诱导流动特性研究

聚焦于表面介质阻挡纳秒脉冲放电(NS DBD)基本问题,设计不同结构激励器,研究放电能量特性、诱导流动特性.结果表明:单位展长激励器单次放电能量随激励电压增大而非线性增大,其值在0.1~1 m J/cm量级,与激励器长度和激励频率无关;NS DBD瞬时功率可达几百千瓦,而时均功率较低,仅为瓦量级.NS DBD诱导流动的速度较低,在0.1 m/s量级上;提升激励电压对诱导速度提升不明显;随激励频率增大有所增大.NS DBD可诱导形成冲击波,其初始运动速度稍高于音速,不同结构激励器诱导冲击波在传播位置上无明显差别,主要影响诱导冲击波个数;激励电压对冲击波传播速度无明显影响;唯象学仿真表明不同沉积能量诱导冲击波速度不同,实验对应下的沉积能量诱导冲击波波速近于音速.     

电力系统在高斯随机小激励下的响应及稳定性

随着可再生能源发电和电动汽车等接入电网,随机激励对电力系统稳定性的影响日渐突出.本文针对高斯型随机激励,在确定性模型的基础上,构造带有高斯型随机激励项的模型.采用Euler-Maruyama（EM）方法对随机响应进行模拟计算,对不同随机激励强度下的功角曲线进行仿真分析,给出了EM方法的数值解稳定性证明.从理论上证明了在高斯型随机激励较小情况下,电力系统的均值稳定性和均方稳定性,并通过仿真算例从统计学角度加以阐释.     

我国上市公司管理层过度自信对会计稳健性的影响

我国资本市场处于转型发展的新时期,上市公司规范管理的重要性日益突出。本文从行为金融学的角度出发,以2012~2014年沪市主板和深市创业板的上市公司为研究对象,选择严格的过度自信衡量方法,提出优化的会计稳健性计算方法,对上市公司管理层过度自信和会计稳健性的关系进行实证研究。结果表明,上市公司管理层的过度自信对公司的会计稳健性有着不利影响,会损害公司的会计稳健性;公司的成长阶段和规模与会计稳健性亦为负相关,规模越大、发展阶段越成熟的上市公司的会计稳健性越低。     

反应动力学参数变化对MOVPE生长GaN的反应路径模拟的影响

在金属有机化学气相外延(MOVPE)生长GaN薄膜的反应-输运过程数值模拟中,反应动力学参数(活化能和指前因子)的选取存在很大的不确定性,从而导致不同的气相反应路径和生长速率.本文对前人采用的反应动力学参数的偏差做了归纳总结,讨论了偏差的来源.在此基础上,本文对垂直转盘式MOVPE反应器生长GaN的反应-输运过程进行数值模拟研究.模拟改变不同的反应动力学参数组合,包括加合物的生成和可逆分解的指前因子、加合物不可逆分解生成氨基物的活化能和指前因子以及三聚物生成的指前因子.通过分析主要含Ga物质的摩尔浓度和对应的生长速率的变化,研究上述反应动力学参数变化对GaN生长反应路径的模拟结果的影响.研究的主要结论如下:(1)不同的指前因子和活化能导致不同的反应路径和生长速率的差异,而热解路径比起加合路径能够更有效地提高生长速率.(2)在不考虑三聚物反应时,预测的生长速率值都与实验值接近.原因在于,输运限制的生长速率取决于含Ga粒子的输运速率,不同的反应路径对含Ga粒子的影响此消彼长,但到达衬底的含Ga粒子的总量变化不大,这也很好地解释了不同文献采用不同的动力学参数模拟都与实验基本吻合的原因.(3)改变三聚物反应的指前因子发现,由于热泳力对大分子的排斥作用,三聚物对生长的贡献很小,生成的三聚物越多,与实验的误差越大.模拟结果澄清了前人在模拟MOVPE生长GaN的反应-输运过程中存在的一些问题,并加深了对GaN生长机理的了解.     

Inherent properties and statistics with individual particles in quantum mechanics

This paper puts forward the hypothesis that the distinctive features of quantum statistics are exclusively determined by the nature of the properties it describes. In particular, all statistically relevant properties of identical quantum particles in many-particle systems are conjectured to be irreducible, ‘inherent’ properties only belonging to the whole system. This allows one to explain quantum statistics without endorsing the ‘Received View’ that particles are non-individuals, or postulating that quantum systems obey peculiar probability distributions, or assuming that there are primitive restrictions on the range of states accessible to such systems. With this, the need for an unambiguously metaphysical explanation of certain physical facts is acknowledged and satisfied.     

Spasmin-like proteins in various ciliates revealed by antibody to purified spasmins ofCarchesium polypinum

Summary It was found that some ciliates,Stentor, Spirostomum andBlepharisma, which can contract rapidly like the stalks of Vorticellidae, have Ca²⁺-binding proteins that are very similar to spasmins, in the immunological sense. The presence of spasmins in other Protozoa and in some Metazoa was also investigated.     

Partial sequence of the gene for a serine protease from a halophilic archaeumhaloferax mediterranei R4, and nucleotide sequences of 16S rRNA encoding genes from several halophilic archaea

A part of the gene coding for a halophilic serine protease from a halophilic archaeumHaloferax mediterranei R4 was amplified by PCR and its 672 nucleotide sequence was determined. Tentative translation to the amino acid sequence suggested that the enzyme was quite similar to halolysin produced by another halophilic archaeum strain 172P1. Nucleotide sequences of 16S rRNA encoding genes from 9 halophilic archaea were determined. Alignment of 19 sequences known so far showed that there are more than 20 positions carrying bases or deletions specific for each halobacterial genus:Halobacterium, Haloarcula, Haloferax, andHalococcus.     

Endorcine cells producing regulatory peptides

Summary Recent data on the immunologication of regulatory peptides and related propeptide sequences in endocrine cells and tumours of the gastrointestinal tract pancreas, lung, thyroid, pituitary (ACTH and opioids), adrenals and paraganglia have been revised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory beenrevised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory polypeptide), neurotensin, glicentin/glucagon-37 and PYY (peptide tyrosine tyrosine) are the main products of gastrointestinal endocrine cells; glucagon, CRF (corticotropin releasing factor), somatostatin, PP (pancreatic polypeptide) and GRF (growth hormone releasing factor), in addition to insulin, are produced in pancreatic islet cells; bombesin-related peptidesare the main markers of pulmonary endocrine cells; calcitonin and CGRP (calcitonin gene-related peptide) occur in thyroid and extrathyroid C cells; ACTH and endorphins in anterior and intermediate lobe pituitary cells, -MSH and CLIP (corticotropoin-like intermediate lobe peptide) in intermediate lobe cells; met- and leu-enkephalins and related peptides in adrenal medullary and paraganglionic cells as well as in some gut (enterochromaffin) cells; NPY (neuropeptide Y) in adrenalin-type adrenal medullary cells, etc.. Both tissue-appropriate and tissue-inappropriate regulatory peptides are produced by endocrine tumours, with inappropriate peptides mostly produced by malignant tumours.     

Cognition wars

In what kinds of physical systems can cognition be realized? There are currently competing answers among scientists and theorists of cognition. There are many plant scientists who maintain that cognition can be realized in plants. There are biological scientists who maintain that cognition is materially realized in bacteria. In this paper, I will present the basis for such claims and evaluate them and discuss the future for theories of the metaphysical basis of cognition in the cognitive sciences.     

Anthelmintic activity of a benzimidazoline compound in sheep by abomasal infusion

Summary In vitro and in vivo data on the benzimidazoline compound indicate anthelmintic potential when introduced directly into the abomasum.     

Evolutionary and ecological implications of cardenolide sequestration in the monarch butterfly

Summary Monarch butterflies sequester cardenolides from their larval host plants in the milkweed genusAsclepias for use in defense against predation. Of 108Asclepias species in North America, monarchs are known to feed as larvae on 27. Research on 11 of these has shown that monarchs sequester cardenolides most effectively, to an asymptote of approximately 350 g/0.1 g dry butterfly, from plants with intermediate cardenolide contents rather than from those with very high or very low cardenolide contents. SinceAsclepias host plant species are distributed widely in space and time across the continent, monarchs exploit them by migration between breeding and overwintering areas. After overwintering in central Mexico, spring migrants east of the Rocky Mountains exploit three predominantAsclepias species in the southern USA that have moderately high cardenolide contents. Monarchs sequester cardenolides very effectively from these species. First generation butterflies are thus well protected against predators and continue the migration north. Across the northern USA and southern Canada most summer breeding occurs on a fourthAsclepias species and in autumn most of these monarchs migrate back to Mexican overwintering sites. The ecological implications of this cycle of cardenolide sequestration for the evolution of monarch migration are discussed.     

Bioaccumulation processes in ecosystems

The fate of environmental pollutants — the various isotopes of elements, and inorganic or organic compounds — is a fundamental aspect of ecology and ecotoxicology, and bioaccumulation is a phenomenon often discussed in this context. Human activities have drastically altered natural concentrations of many substances in the environment and added numerous new chemicals. An understanding of the processes of bioaccumulation is important for several reasons. 1) Bioaccumulation in organisms may enhance the persistence of industrial chemicals in the ecosystem as a whole, since they can be fixed in the tissues of organisms. 2) Stored chemicals are not exposed to direct physical, chemical, or biochemical degradation. 3) Stored chemicals can directly affect an individual's health. 4) Predators of those organisms that have bioaccumulated harmful substances may be endangered by food chain effects. While former theories on the processes of bioaccumulation focused on single aspects that affect the extent of accumulation (such as the trophic level within the food chain or the lipophilicity of the chemical), modern theories are based on compartmental kinetics and the integration of various environmental interactions. Concepts include results from quantitative structure-activity relationships (QSAR), pharmacokinetics, ecophysiology and general biology, molecular genetic aspects and selection, and finally the structure of communities and man-made alterations in them.     

Mating attempts between the Scarlet Tiger Moth,Callimorpha dominula L., and the Cinnabar Moth,Tyria jacobaeae L. (Lepidoptera: Arctiidae), involve a common sex pheromone composition

It has been suggested that a common sex pheromone composition may account for interspecific sexual interactions observed with certain moths in the Arctiidae. In this study, it is demonstrated that the sex pheromones released by females of the Scarlet Tiger Moth,Callimorpha dominula L., and the Cinnabar Moth,Tyria jacobaeae L., have similar activities and elute at the same retention time on analysis by coupled gas chromatography (GC)-electrophysiology with males from each species. Peak enhancement on GC, chiral GC and coupled GC-mass spectrometry using authentic compounds show that the sex pheromone for bothC. dominula andT. jacobaeae is (3Z,6Z,9S,10R)-9,10-epoxyheneicosa-3,6-diene.     

Observation and prediction in ancient astrology

What is the relationship between observations, predictions, texts, and instruments in ancient astrology? By distinguishing between two distinct kinds of observation claim in astrological texts, I show on the one hand the rhetorical and theoretical importance of each kind of observation claim to ancient astrological traditions, and on the other hand how practices of ancient astrology break from observation once astronomical phenomena become reliably predictable. We thus see a shift in practice from observationally derived predictions to a reliance on textual and instrumental authority, even though the rhetoric of ancient astrology still tries to maintain an emphasis on observation.