项目投资决策的现金流量二重分析和决策模型探讨

与其他财务活动比较，项目投资具有投资周期长、变现难、金额多、回报高等特点。因此企业在进行项目投资前，需要充分调查市场，慎重确定投资方向；科学评价项目，全面论证投资效益；足额筹措资金，确保及时执行投资；及时反馈进程，努力控制投资风险。其中，科学评价项目、全面论证投资效益既是项目投资决策的重点，也是难点。笔者拟构建现金流量二重分析模型和现金流量二重分析决策模型，试图全面、客观、准确地评价项目投资效益，促进项目投资决策科学化。

底部钻具组合的二重非线性有限元分析

本文将弯曲井眼中的底部钻具组合(英文名称为Bottom Hole Assembly，简称BHA)作为空间梁来处理，在考虑几何非线性因素的基础上，导出了相应的有限元切向刚度矩阵。然后，利用“施加”与“放松”约束的方法处理了钻柱与井壁之间的接触非线性问题，并且考虑了钻柱与井壁之间摩擦力的影响。在此基础上，建立了对大曲率弯曲井眼中的钻柱进行二重非线性有限元分析的基本方程，以及相应的牛顿－拉斐逊迭代求解技术。最后，通过数值算例和工程算例证明了本文方法的可靠性，所得结果为大曲率井眼轨迹控制提供了参考依据。

二重预想事故排序的快速计算

在线安全分析中 ,二重预想事故由于其后果的严重性已受到越来越多的关注。在本文中 ,提出仅考虑由于一重预想事故引发的继发性二重预想事故 ,即不考虑由于偶然原因引起的两预想事故同时发生的情况 ,在进行计算时 ,采用了完全边界法和自适应边界法相结合的方法 ,并提出了包含电压、无功与有功的综合性能指标 ,从而大大提高了预想事故筛选的速度 ,并且预想事故筛选过程同时进行了一重预想事故筛选和二重预想事故筛选 ,为运行人员提供了更多有用的信息。

寝室文化对大学生社会化的影响研究

大学阶段是广大青年学生社会化进程中的一个重要时期,大学生社会化受多种因素影响,其中大学阶段的寝室文化更是在大学生社会化的过程中有着重要的影响。从大学寝室文化和大学生的社会化入手,分析寝室文化如何影响当代大学生的社会化,旨在发现其中存在的问题,并提出一些可供参考的对策和建议,希望对更好的实现大学生的社会化有所帮助。

马克思经济学特殊方法的传承与创新

马克思经济学创立的二重分析法依据的是经济现象的二重性和特殊的研究目的,为揭示劳资之间的矛盾服务。既然经济学研究科学方法的确立是由研究对象的性质和研究目的决定的,那么,随着经济学这个学科的发展和经济学研究目的的改变,经济学研究方法也要随之改变,在继承马克思经济学二重分析法的基础上,将二重分析法拓展为三重分析法,实现马克思经济学特殊方法的传承与创新。应用三重分析法不但对经济行为主体的决策具有重要的实践意义,而且对经济学者的理论研究具有重要的指导作用,既有利于经济学理论范畴的创新,又有利于构建中国市场经济学理论的新体系。

Flame retardancy and its mechanism of polymers flame retarded by DBDPE/Sb_2O_3

The flammability characterization and thermal composition of polymers flame retarded by decabromodiphenylethane (DBDPE) and antimony trioxide (Sb2O3) were studied by cone calorimeter and thermogravimetry (TG). The results show that ABS/DBDPE/Sb2O3 has the similar flammability parameters and thermal composition curves to ABS/DBDPO/Sb2O3. It suggests that DBDPE/Sb2O3 has the similar flame retardant behavior to DBDPO/Sb2O3. The heat release rate (HRR) and the effect heat combustion (EHC) curves of polymers flame retarded by DBDPE/Sb2O3 all decrease, but the mass loss rate (MLR) curve slightly increase. It shows that the decrease of HRR is not due to the increase of char formation ratio but the generation of incombustible gases. The major flame retardant mechanism of DBDPE/Sb2O3 is gas phase flame retardant mechanism. Increasing content of Sb2O3 in DBDPE/Sb2O3 can improve the flame retardant property and thermal stability of acrylonitrile butadiene styrene. Sb2O3 has a good synergistic effect with DBDPE.

Reactivities of Shenfu Chars Toward Gasification with Carbon Dioxide

Five Shenfu char samples were prepared from Shenfu raw coal at different temperatures （950, 1100, 1200, 1300 and 1400℃） using a muffle furnace. Demineralization of the char samples was performed by treating them with 10% nitric acid for 10 min in a CEM Discover microwave reactor. The gasification of the chars, and corresponding demineralized chars, in a carbon dioxide （CO2） atmosphere was conducted in a Netzsch STA 409Cl31F tempera- ture-programmed thermogravimetry apparatus. The effects of charring temperature and demineralization on the gasification reactivity of chars were systematically investigated. The results show that a char formed at a lower temperature is more reactive except for demineralized char formed at 1100℃, which is less reactive than char formed at 1200℃. Demineralization decreases the char reactivities toward gasification with CO2 to a small extent.

Least Squares Spectral Analysis and Its Application to Superconducting Gravimeter Data Analysis

Detection of a periodic signal hidden in noise is the goal of Superconducting Gravimeter (SG) data analysis. Due to spikes, gaps, datum shrifts (offsets) and other disturbances, the traditional FFT method shows inherent limitations. Instead, the least squares spectral analysis (LSSA) has showed itself more suitable than Fourier analysis of gappy, unequally spaced and unequally weighted data series in a variety of applications in geodesy and geophysics. This paper reviews the principle of LSSA and gives a possible strategy for the analysis of time series obtained from the Canadian Superconducting Gravimeter Installation (CGSI), with gaps, offsets, unequal sampling decimation of the data and unequally weighted data points.

Dissolved Silica Adsorbed onto MnO_2 in Catalyzing the Decomposition of H_2O_2: Molecular Structural Rearrangement Revealed by FTIR,SEM-EDX and XRD

It has been generally unclear over the mechanism of inhibitory influence of silicate on structural rearrangement or solely physical adsorption onto manganese dioxide （MnO2） about the decomposition of hydrogen peroxide （H2O2）. Consequently, several experiments were carried out by using MnO2 as a catalyst for the decomposition of H2O2 in a concentration series under certain concentrations of silicates. The silicates were analyzed by using a molybdenum blue colorimetric method. The results showed that the determination of silicates was inhibited by H2O2, whose inhibitory effect was greatly increased by increasing its concentration, but not limited by pH. SEM-EDX （scanning electron microscopy-energy dispersive x-ray spectrometry） results showed that the adsorption of silicates onto the surface of MnO2 was not purely via a structural rearrangement, with increasing Mn atoms protruding on the outer surface by covering oxygen and silicon atoms. XRD （X-ray diffraction） and FTIR （Fourier transform infrared） spectra results further revealed no significant total crystal structural changes in MnO2 after the adsorption of silicates, but only a small shift of 0.21° at 2e from 56.36° to 56.15° , and a FTIR vibration showed at around 1 050 cm-1. The results, therefore, showed that silicate adsorption onto MnO2 took place via both surface adsorption and structural rearrangement by interfacial reaction.

Synthesis and Characterization of Modified Epoxy Resins by Silicic Acid Tetraethyl Ester and Nano-SiO_2

A kind of modified epoxy resins was obtained by condensation of epoxy resin with silicic acid tetraethyl ester（TEOS） and nano-SiO2. The reactions were performed with hydrochloric acid as a catalyst at 63 ℃. The structure, thermal stability and morphological characteristics of the modified epoxy resins were studied through infrared spectra（FT-IR） analysis, thermogravimetric（TG） analysis and scanning electron microscopy respectively. It has been found from the IR and TG study that modified epoxy resins have greater thermal stability than epoxy resins, and its thermal stability has been improved by the formation of inter-crosslinked network structure. The modified epoxy resins exhibit heterogeneous morphology and heterogeneity increases with more TEOS feeding, which in turn confirms the formation of inter-crosslinked network structure in modified epoxy resins.

Numerical analysis and experimental study of hydrogen production from dimethyl ether steam reforming

An experimental and theoretical study of steam reforming of dimethyl ether was carried out in a processor for fuel cell vehicles to explore the effect of temperature gradient and hydrogen content of the processor.A steady-state,laminar,two-dimensional axi-symmetric model was proposed to investigate the fluid flow,heat transfer and chemical reactions in the dimethyl ether steam reforming processor using porous medium approach.The numerical model was established with Star-CD program using SIMPLE algorithm and finite volume method.Experimental verification of the two-dimensional mathematical model was conducted.The numerical results coincided well with the experimental data.The effects of the parameters on the temperature gradient and hydrogen content of the processor were studied using the numerical model.

A Decision Method Based on Competition Model

We propose a decision method -double scale method to derive the priority vector of finite alternatives with respect to a single criterion based on competition model. Compared with the attribute hierarchical model, the double scale method is reasonable and practical.