制度动力学视角下的行业信用体系法律建设研究

从制度动力学角度看,行业协会天然地出身于市场经济活动中,用以满足各类主体在交易活动中对失信行为予以约束和惩治的需要。以其为基础的行业信用是社会信用体系中的重要组成部分,在社会信用体系建设中具有天然优势。目前中国行业信用体系的法律建设尚处于初级阶段,受历史因素影响,现有法律制度体系难以满足信用体系建设和市场经济发展的要求。因此,必须在立法上明确行业协会独立的私法主体地位,并同时构建各项具体行业信用制度及信息共享机制。

资本结构突变的制度动力学模型探讨

现代资本结构理论缺乏企业资本结构动态调整的制度动力学模型。本文利用新制度经济学的基本理论,研究了相关制度对重新谈判和股票发行时企业资本结构突变的影响,得出的结论是银行监管制度和债权人保护制度的变化,通过银行的债务豁免区的范围和位置而影响处于财务困境中的企业的资本结构被动调整;股票发行制度和股东权利保护制度的变化,通过发行人信号组合的选择而影响利用投资机会的企业的资本结构的主动调整。

论行业协会组织的法律性质——从制度动力学视角

行业协会是指同一行业的商事主体为增进共同利益、维护合法权益而自愿组成的非营利性社会团体法人。从制度动力学的视角来看,行业协会组织是商品经济发展到一定阶段,为满足商事主体间顺利交易的需要,作为一种契约履约机制自发形成并不断演进的。由其生成路径决定,行业协会法人具有非营利性、互益性,是一类私法人。

行业协会组织的制度动力学原理

对转型期行业组织的研究,是现实对理论工作者提出的迫切挑战。行业组织作为一种经济制度,它的定义、它的发生、它的目标和功能、它的变迁以及它的改革,自然是新制度经济学(NIE)最主要的研究对象。但由于行业组织同时又是一种社会组织,它的功能及其对社会政治结构的影响,还必然受到其他社科学家,如社会学,法学和政治学家的极大关注。本文对行业组织的生成和发展在理论规范意义上的考察,正是在这种跨学科的氛围里展开的。

Comparison of pharmacokinetics,efficacy and toxicity profile of gemcitabine using two different administration regimens in Chinese patients with non-small-cell lung cancer

Objective： To conduct a randomized comparative trial of pharmacokinetics, efficacy and toxicity profile treatment with 1200 mg/m^2 gemcitabine using standard 30-min infusion or fixed dose rate （FDR） infusion [10 mg/（m^2-min）] on days 1 and 8 plus carboplatin AUC （area under curve） 5 on day 1 in Chinese non-small-cell cancer patients. Twelve patients were enrolled in this study. Methods： Plasma gemcitabine concentrations were measured by ion-pair reversed phase high performance liquid chromatography. Antitumoral activity and toxicity of gemcitabine was assessed according to World Health Organization criteria. Results： The obtained mean parameters, such as T1/2 （elimination half time）, AUC, and CL （clearance）, were consistent with those reported in literature. Qualified response rate in our study was 33.3% for standard arm and 50% for FDR ann. Additional 50% and 33.3% patients contracted stable disease （SD） in standard arm and FDR arm, respectively. The predominant toxicity was hematologic, and patients in the standard infusion ann experienced consistently more hematologic toxicity, Conclusion： Pharmacokinetic and clinical data in this trial support the continued evaluation of the FDR infusion strategy with gemcitabine.

Dynamic Thermal Model and Temperature Control of Proton Exchange Membrane Fuel Cell Stack

A dynamic thermal transfer model of a proton exchange membrane fuel cell (PEMFC) stack is developed based on energy conservation in order to reach better temperature control of PEMFC stack. Considering its uncertain parameters and disturbance, we propose a robust adaptive controller based on backstepping algorithm of Lyaponov function. Numerical simulations indicate the validity of the proposed controller.

Inproved grade length limitation of freeways

A method of ascertaining grade length limitation of freeways in mountain terrain is presented. The relationship models between 15 th percentile speeds and grades were built through the surveys and analyses of operation speeds on 7 typical sections of 3 freeways in mountain terrain. Using 15 thpercentile and 85 th percentile as speed limitations, the methods of determining admitted velocities were put forward according to the grades. Deceleration distances of longitudinal slopeways were analyzed utilizing the theories of vehicle. According to the results of analysis, grade length limitation was loosed. Finally the values of grade length limitation for freeways were put forward. The results could be used as references for freeway design.

Effects of Low Concentration Methanol, PVP and PVCap on Structure-I Methane Hydrate Formation

Kinetic mechanisms describing how THIs （thermodynamic hydrate inhibitors） and KHIs （kinetic hydrate inhibitors） work on gas hydrate formation have drawn interests for decades. These mechanisms could be better revealed with more fundamental experimental studies. With experiments performed in an isochoric cell with continuous cooling and stirring, this paper presents observed effects of methanol, PVP （polyvinylpyrrolidone, Mw= 15,000） and PVCap （polyvinylcaprolactam, Mw = 6,000） on both nucleation and growth of structure-I methane hydrate at concentrations 100 to 3,000 ppm （i.e., 0.01 to 0.3 wt%）. The results suggest that methanol had no significant effect on nucleation, while it weakly promoted, spontaneous hydrate growth at an early stage. PVP and PVCap gave reduced average nucleation rate at and prior to hydrate onset, while increased the induction time and the degree of sub-cooling. PVP gave no observable effect on total gas intake and average hydrate growth rate. A decreased total gas intake was observed for all concentrations of PVCap.

Vehicle height and leveling control of electronically controlled air suspension using mixed logical dynamical approach

Vehicle height and leveling control of electronically controlled air suspension(ECAS) still poses theoretical challenges for researchers that have not been adequately addressed in prior research. This paper investigates the design and verification of a new controller to adjust the vehicle height and to regulate the roll and pitch angles of the vehicle body(leveling control) during the height adjustment procedures. A nonlinear mechanism model of the vehicle height adjustment system is formulated to describe the dynamic behaviors of the system. By using mixed logical dynamical(MLD) approach, a novel control strategy is proposed to adjust the vehicle height by controlling the on-off statuses of the solenoid valves directly. On this basis, a correction algorithm is also designed to regulate the durations of the on-off statuses of the solenoid valves based on pulse width modulated(PWM) technology, thus the effective leveling control of the vehicle body can be guaranteed. Finally, simulations and vehicle tests results are presented to demonstrate the effectiveness and applicability of the proposed control methodology.

SiC nanowires with thickness-controlled SiO2 shells： Fabrication, mechanism, reaction kinetics and photoluminescence properties

SiC nanowires with thickness-controlled SiO2 shells have been obtained by a simple and efficient method, namely treatment of SiC/SiO2 core-shell nanowires in NaOH solution. The products were characterized by transmission electron microscopy （TEM）, high-resolution transmission electron microscopy （HRTEM）, X-ray diffraction （XRD）, Raman spectroscopy, infrared （IR） spectroscopy, and photoluminescence spectroscopy. The thickness of the SiO2 shell can be effectively controlled by selecting the appropriate processing time, and pure SiC nanowires were also obtained by alkaline cleaning in 1 mol-L-1 NaOH solution for 40 min at 70 ~C. A mechanism for the removal of the SiO2 shells has been proposed, and a two-phase reaction kinetic equation was derived to explain the rate of the removal of the SiO2 shells. The validity of this equation was verified by experiment. This work not only describes an effective experimental method for achieving SiC nanowires with thickness-controlled SiO2 coatings but also provides a fundamental theoretical equation with a certain level of generality. In addition, photoluminescence （PL） measurement results showed that the SiC nanowires sheathed with an optimum SiO2 thickness （3.03 nm） have better photoluminescence properties than either the bare SiC nanowires or SiC nanowires with thicker coatings of SiO2.

Auto-ignition of biomass synthesis gas in shock tube at elevated temperature and pressure

Ignition delay times of multi-component biomass synthesis gas （bio-syngas） diluted in argon were measured in a shock tube at elevated pressure （5, 10and 15 bar, 1 bar = 105 Pa）, wide temperature ranges （1,100-1,700 K） and various equivalence ratios （0.5, 1.0, 2.0）. Additionally, the effects of the variations of main constituents （H2：CO = 0.125-8） on ignition delays were investigated. The experimental results indicated that the ignition delay decreases as the pressure increases above certain temperature （around 1,200 K） and vice versa. The ignition delays were also found to rise as CO concentration increases, which is in good agreement with the literature. In addition, the ignition delays of bio-syngas were found increasing as the equivalence ratio rises. This behavior was primarily discussed in present work. Experimental results were also compared with numerical predictions of multiple chemical kinetic mechanisms and Li＇s mechanism was found having the best accuracy. The logarithmic ignition delays were found nonlinearly decrease with the H2 concentration under various conditions, and the effects of temperature, equivalence ratio and H2 concentration on the ignition delays are all remarkable. However, the effect of pressure is rela- tively smaller under current conditions. Sensitivity analysis and reaction pathway analysis of methane showed that R1 （H ＋O2= O -9 OH） is the most sensitive reaction promot- ing ignition and R13 （H ＋O2 （＋M） = HO2 （＋M））, R53（CH3＋H （＋M）= CH4 （＋M））, R54 （CH4＋H= CH3 ＋ H2） as well as R56 （CH4 ＋ OH = CH3 ＋ H2O） are key reactions prohibiting ignition under current experimental conditions. Among them, R53 （CH3 ＋ H （＋M） = CH4 （＋M））, R54 （CH4 ＋ H = CH3 ＋ H2） have the largest posi- tive sensitivities and the high contribution rate in rich mixture. The rate of production （ROP） of OH of R1 showed that OH ROP of R1 decreases sharply as the mixture turns rich. Therefore, the ignition delays become longer as the equiva- lence ratio increases.

Numerical study on the aerodynamic performance and safe running of high-speed trains in sandstorms

The influence of sandstorms on train aerodynamic performance and safe running was studied in response to the frequent occurrence of sandstorm weather in north China.An Eulerian two-phase model in the computational fluid dynamic (CFD) software FLUENT,validated with published data,was used to solve the gas-solid multiphase flow of a sandstorm around a train.The train aerodynamic performance under different sandstorm levels and no sand conditions was then simulated.Results showed that in sandstorm weather,the drag,lift,side forces and overturning moment increase by variable degrees.Based on a numerical analysis of aerodynamic characteristics,an equation of train stability was also derived using the theory of moment balance from the view of dynamics.A recommended speed limit of a train under different sandstorm levels was calculated based on the stability analysis.

Multi-spacecraft observations of earthward flow bursts

On the basis of the plasma, electric and magnetic fields jointly observed by Cluster and the Double Star TC-I spacecraft in the Earth＇s magnetotail, we have investigated the earthward flow bursts by introducing the momentum equation in the X-direction in the ideal conditions of magneto hydrodynamics （MHD）. One earthward flow burst with a peak in excess of 500 km/s was selected, when the four spacecraft of Cluster were located around -16 RE and TC-1 was located around -10 RE in the X-direction. The inter-spacecraft distances in Y and Z directions were smaller than the statistical spatial scales of the bursty bulk flows. When the Y components of E and -VxB were compared, there was no clear breakdown of the frozen-in condition during the earthward flow burst. With the measured plasma and magnetic parameters from two spacecraft at different positions in the magnetotail, the X component of the pressure gradient was calculated. Magnetic tension was calculated using the mag- netic field measured at four points, which could be compared with the assumed constant in the past research with single satel- lite. When the pressure gradient and the magnetic tension were put into the MHD momentum equation, some samples of the earthward flow bursts were accelerated and some were decelerated. The braking process of the earthward flow burst was more complicated than what the past results had shown. The accelerated samples accounted for about one third of the whole earth- ward flow bursts and discontinuously located among the decelerated elements. The original single earthward flow burst event might be split into several short flow bursts when it was moving to the Earth. Our results may partly illustrate that the duration of fast flows during three phases of substorm becomes short near the Earth. The results are consistent with the past results that fast flows intrude to places earthward the typical braking region.

Investigation of Detailed Kinetic Scheme Performance on Modelling of Turbulent Non-Premixed Sooting Flames

This paper presents the results of an application of a first-order conditional moment closure （CMC） approach coupled with a semi-empirical soot model to investigate the effect of various detailed combustion chemistry schemes on soot formation and destruction in turbulent non-premixed flames. A two-equation soot model repre- senting soot particle nucleation, growth, coagulation and oxidation, was incorporated into the CMC model. The turbulent flow-field of both flames is described using the Favre-averaged fluid-flow equations, applying a stan- dard k-c turbulence model. A number of five reaction kinetic mechanisms having 50 - 100 species and 200 - 1000 elementary reactions called ABF, Miller-Bowman, GRI-Mech3.0, Warnatz, and Qin were employed to study the effect of combustion chemistry schemes on soot predictions. The results showed that of various kinetic schemes being studied, each yields similar accuracy in temperature prediction when compared with experimental data. With respect to soot prediction, the kinetic scheme containing benzene elementary reactions tends to result in a better prediction on soot concentrations in comparison to those contain no benzene elementary reactions. Among five kinetic mechanisms being studied, the Qin combustion scheme mechanism turned to yield the best prediction on both flame temperature and soot levels.

A Unified Lorenz-Like System and Its Tracking Control

This paper introduces the finding of a unified Lorenz-like system.By gradually tuning the only parameter d,the reported system belongs to Lorenz-type system in the sense defined by Clikovsky.Meanwhile,this system belongs to Lorenz-type system,Lu-type system,Chen-type system with d less than,equivalent to and greater than 1.5,respectively,according to the classification defined by Yang.However,this system can only generate a succession of Lorenz-like attractors.Some basic dynamical properties of the system are investigated theoretically and numerically.Moreover,the tracking control of the system with exponential convergence rate is studied.Theoretical analysis and computer simulation show that the proposed scheme can allow us to drive the output variable x\ to arbitrary reference signals exponentially,and the guaranteed exponential convergence rate can be estimated accurately.