基于24Model-D-ISM的地铁站火灾疏散影响因素研究

为预防地铁站火灾事故,深入了解地铁站火灾人员疏散影响因素间的内在联系与层次结构,基于第6版“2-4”模型(24Model)分析63起地铁站火灾疏散事故,充分考虑各个因素之间的交互作用,提取19个影响地铁站人员疏散的关键因素,建立地铁站火灾人员疏散影响因素指标体系;采用算子客观赋权法(C-OWA)改进决策试验与评价实验法(DEMATEL),确定地铁站火灾人员疏散的重要影响因素;在此基础上,采用解释结构模型(ISM)分析各个因素间的层次结构及相互作用路径,构建地铁站火灾人员疏散影响因素的多级递阶结构模型。研究结果表明:疏散引导、恐慌从众行为、人员拥挤为地铁站火灾人员疏散的关键影响因素;地铁站火灾人员疏散受表层因素、中间层因素、深层因素共同作用的影响,其中,疏散教育与培训、设施维护与检查、疏散预案等因素是根源影响因素,重视根源影响因素的改善有利于从本质上预防和控制事故的发生。

A Two-Sector Economic Growth Model with Labor Force Transfer

In this paper, a two\|sector growth model is given. The labor force transfer process from agricultural sector to industrial sector is exogenous determined. By introducing the labor force transferring function, a two\|dimension nonautonomous differential equation is obtained. The results of the model manifest that the labor force transfer delays industrial sector growth and accelerates the agricultural sector growth. It is proved that the solution of the model is asymptotic stable. By the numerical analysis, the economic growth and labor force transfer is presented under the specific parameters.

Model and Characteristics of China's Service Sector Reform during 1978-2016

This paper intends to provide an in-depth and comprehensive analysis of China＇s service sector reform during 1978-2016 and characterize the model of the service sector reform. Due to unique national conditions and development journey, China＇s service sector reform was carried out in the context of China＇s overall reform and opening-up program based on non-industrial motivations with a pragmatic approach to improve both people＇s livelihood and efficiency and address practical problems facing China in various stages of its development, putting aside theoretical controversies. How to further improve the model of China＇s service sector reform that came into shape in such a unique historical context and advance service sector reform is an important yet arduous task.

An Investigation into Green Total Factor Productivity in China's Carbon-Intensive Sectors and Its Influencing Factors

This paper uses an SBM-GML index model to assess Green Total Factor Productivity(GTFP)in China's carbon-intensive sectors and conducts an empirical investigation into which factors influence GTFP in these sectors.The GTFP in the carbon-intensive sectors experienced a decline between 2006 and 2011,followed by an upward trend beginning in 2012.Technological progress was the primary driver of GTFP growth,while business size was also a notable contributor.Irrational energy structures negatively influenced the high-quality development of the carbon-intensive sectors,and environmental regulation and foreign direct investment(FDI)have not yet significantly impacted GTFP.Based on these findings,this paper suggests that the carbon-intensive sectors should expedite their green transitions by focusing on system improvement,technological innovations,energy revolutions,and high-level opening up.

Overreliance on Net Export and Investment Impedes China's Structural Transformation: Estimation and Analysis Based on a Multi-Sector Growth Model

Since reform and opening-up in 1978, changes in China's industrial structure have generally followed the pattern of "Kuznets facts" but still exhibits some unique characteristics, which led us to raise the following three questions regarding China's structural transformation:(1) Why did the share of China's agricultural and manufacturing employment reduce/increase intermittently rather than continuously?(2) Why did the share of China's agricultural employment increase during certain periods? When the share of manufacturing employment reduced, why did the workforce reversely flow into agriculture rather than move to the service sector?(3) Why did growth in the share of China's service sector employment decelerate before reaching its peak? Why did the share of employment in the industrial sector suddenly increase after an abrupt decline? This paper creates a multisector economic growth model that contains non-homothetic preferences and differentiated productivity, and incorporates the "two drivers" therein for a demand-side estimation and analysis. The result shows that China's economic growth model driven by net export and investment is a critical factor for explaining the three questions regarding its structural transformation. This paper believes that only by implementing supply-side structural reforms, reducing the dependence on net export and investment, and achieving sustainable endogenous economic growth will China be able to expedite its industrial restructuring.

Parameter Extraction for 2-π Equivalent Circuit Model of RF CMOS Spiral Inductors

A novel parameter extraction method with rational functions is presented for the 2-πequivalent circuit model of RF CMOS spiral inductors. The final S-parameters simulated by the circuit model closely match experimental data. The extraction strategy is straightforward and can be easily implemented as a CAD tool to model spiral inductors. The resulting circuit models will be very useful for RF circuit designers.

房地产股价波动对高技术板块的溢出效应研究——基于DGC-t-MSV模型

过度的金融资产投资可能导致房地产股价泡沫,并且通过风险溢出渠道给高技术板块带来价格冲击。研究聚焦于房地产行业和高技术产业的股票价格指数,结合MODWT分解和DGC-t-MSV模型进行实证分析,结果表明:其一,“房地产-高技术”的股票价格动态相关,房地产行业价格波动的传导作用更加强烈,对高技术板块具有明显的溢出效应;其二,实施限制性政策后房地产行业的挤出效应降低,高技术及其分类产业的创新投入受到的限制逐渐减弱;其三,短、中期频繁交易是导致房地产溢价的主要原因,需要警惕高技术板块面临的溢出风险。积极引导高技术板块的价值投资,合理配置技术要素,能够有效促进高技术产业的高质量、高水平发展。

中国产业部门隐含碳生产率的驱动因素分解——基于LMDI-PDA模型的实证分析

提升隐含碳生产率是产业部门碳减排的关键。基于2002—2020投入产出数据与能源碳排放数据建立隐含碳生产率指标,利用LMDI-PDA综合分解法,系统梳理各效应、各细分产业部门对产业部门整体隐含碳生产率变动的影响。研究结论为:直接排放率效应对28个产业部门中的大部分产业部门的隐含碳生产率提升起到阻碍作用,排放能效效应以及能源资本替代效应则主要起积极作用;隐含碳生产率效应普遍推动三次产业隐含碳生产率上升,排放结构效应则阻碍第二产业与第三产业隐含碳生产率的增长,负向效应分别为-0.0166万元/吨、-0.0190万元/吨;对产业部门整体隐含碳生产率增长贡献最大的两个产业部门是其他服务业和建筑业。研究结论为加速推进产业低碳变革提供了理论与数据支撑。

A hybrid Lagrangian-Eulerian numerical model for sea-ice dynamics

A hybrid Lagrangian - Eulerian （HLE） method is developed for sea ice dynamics, which combines the high computational efficiency of finite difference method （FDM） with the high numerical accuracy of smoothed particle hydrodynamics （SPH）. In this HLE model, the sea ice cover is represented by a group of Lagrangian ice particles with their own thicknesses and concentrations. These ice variables are interpolated to the Eularian gird nodes using the Gaussian interpolation function. The FDM is used to determine the ice velocities at Eulerian grid nodes, and the velocities of Lagrangian ice particles are interpolated from these grid velocities with the Gaussian function also. The thicknesses and concentrations of ice particles are determined based on their new locations. With the HLE numerical model, the ice ridging process in a rectangular basin is simulated, and the simulated results are validated with the analytical solution. This method is also applied to the simulation of sea ice dynamics in a vortex wind field. At last, this HLE model is applied to the Bohai Sea, and the simulated concentration, thickness and velocity match the satellite images and the field observed data well.

Analysis of axial strain in one-dimensional loading by different models

Different phenomenological equations based on plasticity, primary creep （as a viscoplastic mechanism）, secondary creep （as another viscoplastic mechanism） and different combinations of these equations are presented and used to describe the material inelastic deformation in uniaxial test. Agreement of the models with experimental results and with the theoretical concepts and physical realities is the criterion of choosing the most appropriate formulation for uniaxial test. A model is thus proposed in which plastic deformation, primary creep and secondary creep contribute to the inelastic deformation. However, it is believed that the hardening parameter is composed of plastic and primary creep parts. Accordingly, the axial plastic strain in a uniaxial test may no longer be considered as the hardening parameter. Therefore, a proportionality concept is proposed to calculate the plastic contribution of deformation.

Analytical models for the penetration of semi-infinite targets by rigid,deformable and erosive long rods

A theoretical study is presented herein on the pen- etration of a semi-infinite target by a spherical-headed long rod for Yp 〉 S, where Yp is the penetrator strength and S is the static target resistance. For Yp 〉 S, depending upon initial impact velocity, there exist three types of penetration, namely, penetration by a rigid long rod, penetration by a deforming non-erosive long rod and penetration by an erosive long rod. If the impact velocity of the penetrator is higher than the hydrodynamic velocity （VH）, it will penetrate the target in an erosive mode; if the impact velocity lies between the hydrodynamic velocity （VH） and the rigid body velocity （VR）, it will penetrate the target in a deformable mode; if the impact velocity is less than the rigid body velocity （VR）, it will penetrate the target in a rigid mode. The critical conditions for the transition among these three penetration modes are proposed. It is demonstrated that the present model predictions correlate well with the experimental observations in terms of depth of penetration （DOP） and the critical transition conditions.

Periodic Packing Mode for Trickle-Bed Reactors: Experiments and Modeling

A periodic packing mode of trickle-bed reactor (TBR) for the gas limited reaction was proposed. Hy-drogenation of 2-ethylanthraquinone over Pd/Al2O3 in a laboratory-scale TBR was taken as a test reaction for determining whether the periodic packing mode is advantageous. The effects of operating conditions and packing type on TBR performance were experimentally examined to demonstrate the cause-effect relationships. A mathe-matic model of TBR considering axial dispersion and fractional wetting was developed to quantitatively illuminate the reason of performance enhancement.

Numerical analysis of the failure process of soil-rock mixtures through computed tomography and PFC3D models

Soil-rock mixture （SRM） is a unique type of geomaterial characterized by a heterogeneous composition and a complicated structure. It is intractable for the continuum-based soil and rock mechanics theories to accurately characterize and predict the SRM＇s mechanical properties. This study reports a novel numerical method incorporating microfocus computed tomography and PFC3D codes to probe the deformation and failure processes of SRM. The three-dimensional （3D） PFC models that represent the SRM＇s complex structures were built. By simulating the entire failure process in PFC3D, the SRM＇s strength, elastic modulus and crack growth were obtained. The influence of rock ratios on the SRM＇s strength, deformation and failure processes, as well as its internal mesoscale mechanism, were analyzed. By comparing simulation results with experimental data, it was verified that the 3D PFC models were in good agreement with SRM＇s real structure and the SRM＇s compression process, deformation and failure patterns; its intrinsic mesomechanism can be effectively analyzed based on such 3D PFC models.

Roll System and Stock's Multi-parameter Coupling Dynamic Modeling Based on the Shape Control of Steel Strip

The existence of rolling deformation area in the rolling mill system is the main characteristic which dis- tinguishes the other machinery. In order to analyze the dynamic property of roll system＇s flexural deformation, it is necessary to consider the transverse periodic movement of stock in the rolling deformation area which is caused by the flexural deformation movement of roll system simul- taneously. Therefore, the displacement field of roll system and flow of metal in the deformation area is described by kinematic analysis in the dynamic system. Through intro- ducing the lateral displacement function of metal in the deformation area, the dynamic variation of per unit width rolling force can be determined at the same time. Then the coupling law caused by the co-effect of rigid movement and flexural deformation of the system structural elements is determined. Furthermore, a multi-parameter coupling dynamic model of the roll system and stock is established by the principle of virtual work. More explicitly, the cou- pled motion modal analysis was made for the roll system. Meanwhile, the analytical solutions for the flexural defor- mation movement＇s mode shape functions of rolls are discussed. In addition, the dynamic characteristic of the lateral flow of metal in the rolling deformation area has been analyzed at the same time. The establishment ofdynamic lateral displacement function of metal in the deformation area makes the foundation for analyzing the coupling law between roll system and rolling deformation area, and provides a theoretical basis for the realization of the dynamic shape control of steel strip.

Investment in deepwater oil and gas exploration projects:a multi-factor analysis with a real options model

Deepwater oil and gas projects embody high risks from geology and engineering aspects, which exert substantial influence on project valuation. But the uncer- tainties may be converted to additional value to the projects in the case of flexible management. Given the flexibility of project management, this paper extends the classical real options model to a multi-factor model which contains oil price, geology, and engineering uncertainties. It then gives an application example of the new model to evaluate deepwater oil and gas projects with a numerical analytical method. Compared with other methods and models, this multi-factor real options model contains more project information. It reflects the potential value deriving not only from oil price variation but also from geology and engi- neering uncertainties, which provides more accurate and reliable valuation information for decision makers.

Modelling of Quasi 3-D Groundwater Flow and Studying of Equivalent Drainage Boundary in Beihai Peninsula,Guangxi

This paper describes a quasi 3-D finite element model of the groundwater flow in two -aquifer system which is constructed from a sequence of aquifer flow equations coupled by leakage terms representing flow through the aquitard . It is applied to evaluate the maximum rate of groundwater resources exploited from the coastal aquifer without seawater intrusion . The main task in this model is to determine the drainage boundary of the aquifer extending under the sea . The information of the boundary can be obtained from the fluctuations of the groundwater level caused by sea-tide fluctuations . A new idea, Equivalent Drainage Boundary (EDB), is proposed and the corresponding methods , determining the EDB, are developed with tidal fluctuations data observed in boreholes . The quasi 3-D model and the methods determining EDB have been applied to the aquifer system of Beihai peninsula , Guangxi Autonomous Region of China for calculating the available groundwater resources .

Kinetic Modeling the Formation of Low-mature Gases and Analysis of the Possibility to Be Accumulated

At present, shallow gases have received much attention due to low cost in exploration and production. Low-mature gases, as one significant origin to shallow gas, turns to be an important research topic. The present understanding of low-mature gases is confined within some geological cases, and few laboratory studies have been reported. Therefore, the potential and characters of low- mature gases are not clear up to now. Here, two premature samples （one coal and the other shale） were pyrolyzed in a gold confined system. The gaseous components including hydrocarbon gases and non-hydrocarbon gases were analyzed. Based on kinetic modeling, the formation of low-mature gases was modeled. The results showed that during low mature stage, about 178 mL/gTOC gas was generated from the shale and 100 mL/gTOC from the coal. Two third to three fourth of the generated gases are non-hydrocarbon gases such as H2S and CO2. The total yields of C1-5 for the two samples are almost the same, 30-40 mL/gTOC, but individual gaseous hydrocarbon is different. The shale has much lower C1 but higher C2-5, whereas the coal has higher C1 but lower C2-5. Hydrocarbon gases formed during low-mature stage are very wet. The stable carbon isotope ratios of methane range from -40‰ to -50‰ （PDB）, in good consistence with empiric criterion for low-mature gases summed up by the previous researchers. The generation characters suggest that the low-mature gases could be accumulated to form an economic gas reservoir, but most of them occur only as associated gases.

Thermodynamic modeling and phase diagram prediction of salt lake brine systemsⅡ.Aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) and its subsystems

It is still a challenging task to accurately and temperature-continuously express the thermodynamic properties and phase equilibrium behaviors of the salt-lake brine with multi-component,multitemperature and high concentration.The essential subsystem of sulfate type brine,aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) and its subsystems across a temperature range from 250 K to 643 K are investigated with the improved comprehensive thermodynamic model.Liquid parameters(Δg_(IJ),Δh_(IJ),and ΔC_(p,IJ))associated with the contributions of Gibbs energy,enthalpy,and heat capacity to the binary interaction parameters,i.e.the temperature coefficients of eNRTL parameters formulated with a Gibbs Helmholtz expression,are determined via multi-objective optimization method.The solid constantsΔ_(f)G_(k)°^((298.15))andΔ_(f)H_(k)°^((298.15))of11 solid species occurred in the quaternary system are rebuilt from multi-temperature solubilities.The modeling results show the accurate representation of(1)solution properties and binary phase diagram at temperature ranges from eutectic points to 643 K;(2)isothermal phase diagrams for Li_(2)SO_(4)-Na_(2)SO_(4)-H_(2)O,Li_(2)SO_(4)-K_(2)SO_(4)-H_(2)O and Na_(2)SO_(4)-K_(2)SO_(4)-H_(2)O ternary systems.The predicted results of complete structure and polythermal phase diagram of ternary systems and the isothermal phase diagrams of quaternary system excellently match with the experimental data.

A Numerical Algorithm Based on Quadratic Finite Element for Two-Dimensional Nonlinear Time Fractional Thermal Diffusion Model

In this article,a high-order scheme,which is formulated by combining the quadratic finite element method in space with a second-order time discrete scheme,is developed for looking for the numerical solution of a two-dimensional nonlinear time fractional thermal diffusion model.The time Caputo fractional derivative is approximated by using the L2-1formula,the first-order derivative and nonlinear term are discretized by some second-order approximation formulas,and the quadratic finite element is used to approximate the spatial direction.The error accuracy O(h3+
t2)is obtained,which is verified by the numerical results.

Aeroelastic modeling of wind loading on a cable-net supported glass wall

Wind loading study on a cable-net supported glass wall is conducted by means of wind tunnel tests. An equiva- lent aeroelastic model is designed and constructed. Response of displacements of the wall is measured and analyzed. In order to design a glass wall under wind loading, the ＂wind- vibration factor＂ is estimated and discussed. In fact, the mech- anism of wind acting on the wall is commonly known not only as positive pressure, but also as negative pressure caused by the flow separation on the corners of the building. Due to the diffidence in the mechanism of wind acting, two typi- cal response cases are classified. The results show that the dynamic response of the structure caused by the negative pressure is stronger than that of the positive pressure case. To determine the aerodynamic wind loading on a flexible part of structure on a building, wind tunnel study may be useful and play an important role.