利用道岔条件实现可动渡线的轨道区段检测方案

以计轴在跨坐式轻轨中的运用,提出利用道岔条件实现可动渡线的轨道区段检测方法及思路。

人口流动规律及其政策含义

人口流动是人力资源配置优化的根本创新路径 ,人口流动的一般规律是 :如果流动人口为理性行为选择者 ,在社会制度安排许可的发展环境下 ,当不同区域和不同产业间形成比较收益差异 ,存在着流动收益大于流动成本的潜在和现实的各种获利机会时 ,就必定驱使人们由低收益领域向高收益领域流动 ,而且比较收益差异量与流动人口的流速、流量正相关 ,并必然导致产生收益率及人口分布走向平均化的趋势 ,社会发展也将获得最优化的人力资源配置结果。其相关政策含义 :一是人口流动是流动人口的理性选择 ;二是切实保障公民的自由流动权利 ;三是利用比较利益差别促进人口流动 ;四是降低各种不必要的流动成本和流动风险 ;

基于GARCH模型的房地产投资风险波动性探析

房地产投资是大众投资的首选，但是投资风险也不容忽视。传统对于投资行为所面临到的风险仅以标的资产价格的非条件变异数或标准差作为衡量尺度，认为投资风险是固定的，未考虑随时间改变的条件变异数来估计风险。文章基于GARCH模型着重分析房地产投资风险波动性情形。

基于植入SV的VaR模型的股指期货风险度量

股指期货交易在规避股票市场风险的同时,产生了新的风险———投机风险和套期保值风险。从上述两种风险的基本概念出发,建立了其对应的VaR度量模型。将SV植入VaR模型中,用于模型中参数的计算,更好地体现金融市场的本质特征。本文对参数计算的实现过程作了一定的论述,研究成果具有重要的理论和实际意义。

汇率改革对人民币NDF与DF关系的影响——基于中国金融管制背景下的实证研究

通过对亚洲金融危机以来,1年期NDF汇率和DF汇率的波动以及贴水点数比较,发现人民币NDF市场和DF市场之间存在着相互影响的关系,其中NDF市场对DF市场的影响在汇改之前要大于DF市场对NDF市场的影响,但是在汇改以后,出现相反的情况,且国内的汇率水平正在接近一个合理的水平。为此,我国应加强国内远期外汇市场建设,完善外汇市场体系。

High Pressure Phase Stability of Ti with Self-consistent ab initio Lattice Dynamics Approach

The traditional quasiharmonic approximation cannot predict the phase diagram of Ti accu- rately, due to the well-known soften phonon modes of the β-Ti. By means of self-consistent ab initio lattice dynamics （SCAILD） method, in which the effects of phonon-phonon in- teractions are considered, the phonon dispersion relations at finite temperature for Ti are calculated. From the phonon dispersions, we extrapolat the acoustic velocities and harmonic elastic constants. The dynamical stable regions and phase diagram of Ti are also predicted successfully. The results show that SCAILD method can be designed to work for strongly anharmonic systems where the QHA fails.

Thiopurine use associated with reduced B and natural killer cells in inflammatory bowel disease

To identify which blood and mucosal lymphocyte populations are specifically depleted by thiopurine use in vivo.METHODSThe thiopurines azathioprine and 6-mercaptopurine have been a mainstay of inflammatory bowel disease (IBD) therapy for decades, but their mechanism of action in vivo remains obscure. Although thiopurines are lymphotoxic at high doses, and have been reported to cause T cell apoptosis in vitro, their ability to control IBD at lower doses suggests that they may selectively deplete particular lymphocyte populations. Blood cells from 19 IBD patients on a thiopurine, 19 IBD patients not on a thiopurine, and 38 matched healthy control subjects were analyzed by multiple multi-color flow cytometry panels to quantify the immune cell subsets contained therein, both as a percent of cells, and as an absolute cell count. Similar analyses were performed on colon biopsies from 17 IBD patients on a thiopurine, 17 IBD patients not on a thiopurine, and 49 healthy screening colonoscopy recipients.RESULTSComplete blood counts revealed lower lymphocyte, but not monocyte or granulocyte, counts in IBD patients who were taking thiopurines at the time of sampling. This reduction was restricted to CD3-negative lymphocytes, wherein both natural killer (NK) and B cells were significantly reduced among thiopurine recipients. Among CD19+ B cells, the transitional B cells were particularly depleted, being nearly absent in both blood and colon biopsies of thiopurine recipients. No differences were associated with thiopurine use in CD8+ T cells, mucosa-associated invariant T (MAIT) cells, invariant natural killer T (iNKT) cells, gamma/delta T cells, Th1, Th17, regulatory T cells (Tregs) or naïve CD4+ T cells. However, patients with IBD had significantly more circulating FOXP3+, Helios+ Tregs and fewer iNKT and MAIT cells than healthy controls.CONCLUSIONThiopurine use is associated with reduced B and NK cell, but not T cell, subpopulations in the blood of IBD patients.

Hydrodynamic characteristics of Wujiangdu Reservoir during the dry season-a case study of a canyon reservoir

With the development of hydropower in the karst area of Southwest China, a series of cascade canyon reservoirs have been formed through the construction of dams. Given that hydrodynamic conditions in canyon reservoirs play a pivotal role in controlling the spatiotemporal distribution of physical and chemical properties of the stored water, hydrodynamic characteristics are of great importance in understanding biogeochemical cycles in those reservoirs. To further this understanding, a field campaign was conducted in the Wujiangdu Reservoir of Guizhou Province. It was found that from the reservoir inlet to the front of the dam, velocity(v) was negativelycorrelated and had a logarithmic relationship with distance along the ship track(s) under dry-season flow conditions[v =-0.104 ln(s) + 0.4756]. Analysis showed that dryseason flow velocity had no significant correlation with water temperature, p H, or dissolved oxygen(DO). However, when velocity decreased to 0.061 m/s, water depth increased abruptly. In addition, DO displayed a sudden drop and the trend in p H changed from increasing to decreasing, while water temperature showed an opposite trend, indicating the existence of a transition zone from the river to the reservoir.

FE Analysis of Longitudinal Dynamic Response of Subgrade in Bridge-Subgrade Transition of Heavy Haul Railway

With the increase of axle load and the train speed, dynamic interaction of train-track system becomes so exacerbated that the deformation and dynamic response of subgrade are more aggravated. The differential settlement will be created in bridge-embankment transition section under such dynamic action, and an adverse effect on the train operation safety can be caused. Meanwhile, differential settlement will produce additional dynamic effect when high-speed trains go through the transition between bridge-embankment. Such dynamic action will aggravate the differential settlement and subgrade damage. This paper applies the methods of field test and finite-element to systematically study the dynamic response characteristics of subgrade in bridge-embankment transition section of heavy haul railway under dynamic load for the first time. This research is focused on the analysis of influence of the different axle load, train speed, filled soil modulus, etc.. At last, the dynamic response rules are systematically summarized.

Experimental Investigation of Electric Drive Dynamics

Induction motor is used in many applications to drive an electromechanical system. Transients of the motor torque and speed are outlined by the inertia of rotating rotor. The paper deals with influence of rotor inertia to transients of motor speed. The method of speed control measurement and experimental equipment is discussed. Simulation and experimental results are compared.

Studies on genetic relationships among Oakleaf loquat, Daduhe loquat and common loquat by RAPD and ISSR

The genetic relationships among oakleaf loquat （Eriobotrya prinoides）, Daduhe loquat （Eriobotrya prinoides var. dadunensis） and common loquat （Eriobotrya japonica） were studied by RAPD and ISSR markers. The results showed that the similarity coefficient between oakleaf loquat and common loquat was minimal （0.6996 and 0.7219, respectively） and the similarity coefficient between oakleaf loquat and Daduhe loquat was maximal （0.8403 and 0.8211, respectively）, while the similarity coefficient between Daduhe loquat and common loquat was always intermediate （0.7195 and 0.7219, respectively）. The highest additivity was obtained when Daduhe loquat was regarded as the undetermined hybrid （44.9% and 45.8%, respectively）. The specific bands of oakleaf loquat and common loquat were present in Daduhe loquat. Thus, it could be concluded that Daduhe loquat was a hybrid of oakleaf loquat and common loquat.

Ab initio Molecular Dynamics Study of Adsorption of Hydroxyl Groups on Graphene Surface

Reduced graphene oxide is the precursor to produce graphene in a large scale;however,to date,there has been no consensus on the electronic structure of reduced graphene oxide.In this study,we carried out an ab initio molecular dynamics simulation to investigate the adsorption process of hydroxyl groups on graphene surface.During the adsorption process,the OH group needs to firstly pass through a physical adsorption complex with the OH above the bridge site of two carbon atoms,next to surmount a transition state,then to be adsorbed at the atop site of a carbon atom.With a 5×5 graphene surface,up to 6 hydroxyl groups can be adsorbed on the graphene surface,indicating the concentration coverage of the hydroxyl groups on graphene surface is about 12%.The simulation results show that the negative adsorption energy increases linearly as the number of adsorbed hydroxyl groups increases,and the band gap also increases linearly with the number of adsorbed hydroxyl groups.

A Simple Lumped Mass Model to Describe Velocity of Granular Flows in a Large Flume

This paper presents a lumped mass model to describe the run-out and velocity of a series of large flume tests,which was carried out to investigate some propagation mechanisms involved in rapid,dry,dense granular flows and energy transformation when the flows encountered obstacles and reoriented their movement directions.Comparisons between predicted and measured results show that the trend of predicted velocities was basically matched with that of measured ones.Careful scrutiny of test videos reveals that subsequent particles with a higher velocity collided with slowed fronts to make them accelerate. However,this simple model cannot reflect collisions between particles because it treated released materials as a rigid block.Thus,the predicted velocity was somewhat lower than the measured velocity in most cases.When the flow changed its direction due to the variation in slope inclination,the model predicted a decrease in velocity.The predicted decrease in velocity was less than the measured one within a reasonable range of 10% or less.For some cases in which a convexity was introduced,the model also predicted the same trend of velocities as measured in the tests.The velocity increased greatly after the materials took a ballistic trajectory from the vertex of the convexity,and reduced dramatically when they finally made contact with the base of the lower slope.The difference between prediced and measured decrease in velocity was estimated to be about 5% due to the landing.Therefore,the simple lumped mass model based on the energy approach could roughly predict the run-out and velocity of granular flows,although it neglected internal deformation,intergranular collision and friction.

A model of local labor market regulation of China in the transition period

With the establishment of labor market of China, market is playing a more and mare important role in allocation of human resources. However, with the transition of economy in China and industrial upgrading in recent years, many labor problems have occurred which do harm to the sustainable development of local economy. The paper researches on the labor market issues of China from the perspective of local labor market regulation. Firstly, it reviews the theories of local labor market regulation. And then the main components of local labor market regulation of China are identified and the evaluation index system is established. The results of analysis of the calculated output show that （1） the local labor market regulation of China has an obvious character of gradient distribution geographically and decreases gradually from east to west; （2） of all the regulations, the regulation of the development of human capital has the most significant impact on local economy currently which is followed by the regulation of labor relation and the regulation of market participation. As to the regulation of social security, it has no Significant impact on the development of local economy.

Two-dimensional semiconductors with possible high room temperature mobility

We have calculated the longitudinal acoustic phonon limited electron mobility of 14 twvo-dimensional semiconductors with composition of MX2, where M （= Mo, W, Sn, Hf, Zr and Pt） is the transition metal, and X is S, Se and Te. We treated the scattering matrix by the deformation potential approximation. We found that out of 14 compounds, MoTe2, HfSe2 and ZrSe2 are promising regarding to their possible high mobility and finite band gap. The phonon limited mobility can be above 2,500 cm^2·V^-1·s^-1 at room temperature.

The Constructional Meaning and the Semantic Make-up of the Chinese Ba-construction

From the perspective of Cognitive Grammar, this study investigates the semantic characteristics of, as well as the respective constraints on, the three （schematic） components of the Chinese ba-construction that are essential in its constructional meaning, namely the pre-posed object, the main verb, and the resultative component, and concludes that the Chinese bd--construction describes a transition between two states of affairs, either intended or actualized, with the post- transitional state being the focus of attention, and that the semantic characteristics of its component structures, the main verb, the pre-posed object, and the resultative component in particular, synergistically contribute to the accentuation of this constructional meaning： the lexical aspect of the main verb signals the potential for transition; the high degree of specificity of the pre-posed object conserves cognitive resources as well as measures out the process denoted by the main verb; and the rich forms and the almost obligatory presence of the resultative component specify the post-transitional state and command the bearer＇s attention.

SPECIAL ISSUE： DISTRIBUTION OF NATIONAL INCOME IN A TRANSITIONAL ECONOMY Changes in the labor share of GDP： a U-shaped curve

In this paper, we try to find some general rules and the structural factors that cause a fall in labor economic growth in countries all over the world, the by a U-shaped curve in which the tuming point is for labor share in primary distribution share. We show that, in the process of evolution of labor share is characterized $6,000 per capita GDP （in PPP, 2000）. We develop a model to explain this phenomenon that provides an in-depth explanation for Kuznets＇ inverted U hypothesis. Our findings indicate that the evolution of China＇s labor share is basically consistent with the model we have constructed. In addition, sectoral composition and the relative bargaining power of labor are also factors influencing labor share. These findings imply that labor share of primary distribution in China may enter an upward trajectory over the next two years. This process may be accelerated by the central government＇s policies for dealing with global financial crisis and by structural adjustment.

Optimal Force Mismatch for Fluctuation-Activated Transition in a System of Two Coupled Bistable Oscillators

We study the fluctuation-activated transition process in a system of two coupled forced bistable oscillators with a mismatch σ in the force constants. As the coupling strength μ is increased, the transition pathway undergoes four stages changes from a two-step process with two candidate pathways to a mixture of a two-step pathway and a one-step pathway to a one-step process with also two candidate pathways and then to a one-step process with a single pathway.Interestingly, we find that the total transition rate depends nonmonotonically on σ in the weak coupling: a maximal rate appears in an intermediate magnitude of σ. Moreover, the rate also exhibits an unexpected maximum as a function ofμ. The results are in an excellent agreement with our numerical simulations by forward flux sampling.

Mechanistic study and kinetic properties of the CF_3CHO+Cl reaction

Theoretical investigations have been carried out on the mechanism and kinetics for the reaction of CF 3 CHO + Cl using duallevel direct dynamics method. The potential energy surface information was obtained at the MCQCISD/3//MP2/cc-pVDZ level and the kinetic calculations were done using variational transition state theory with interpolated single-point energy (VTST-ISPE) approach. The calculated results show that the reaction proceeds primarily via the H-abstraction channel, while the Cl-addition channel is unfavorable due to the higher barriers. The improved canonical variational transition-state theory (ICVT) with the small-curvature tunneling correction (SCT) was used to calculate the rate constants. The theoretical rate constants at room temperature are in general agreement with the experimental values. A three-parameter rate constant expression was fitted over a wide temperature range of 200-2000 K.