近代广东商业人群在广西的分布面及其梯度差考详——粤港商业经济对广西经济辐射研究之二

文章从中国近代史上城镇经济主体——商业经济的角度切入,运用各类历史资料,分区逐县地确证广东商业人群以及所造成的“无东不成市”格局在全广西的分布范围,并揭示其在广西不同地域的程度等差和梯度分布状态。从而,以原始的生活场景原生态地呈现出粤港澳地区对广西经济辐射由东而西逐步推进、由城市而圩市逐层次渗透的基本节奏和客观规律。

直角坐标下正弦分布面电流元近场分析

本文从并矢格林函数的场方程出发 ,研究直角坐标下长方形电流元的场分布 ,分别给出考虑线电荷影响及不考虑线电荷影响两种情况下用指数积分表示的严格近场表达式 。

基于ArcGIS的连续分布面域的公共边编辑处理的方法研究

行政区划图、植被图、土地利用类型图、地表覆盖分类图等描绘的是一种地球表面非常普遍的连续分布面域现象。本文基于ArcGIS,首先阐述运用拓扑工具检索并解决连续分布面域出现的有重叠或有缝隙问题,然后列出对无几何错误的连续分布面域进行公共边的形状改变和结点移动的方法。

In-situ thermal Raman mapping and stress analysis of CNT/CF/epoxy interfaces

A study of the interfacial behavior and internal thermal stress distribution in fiber-reinforced composites is essential to assess their performance and reliability.CNT/carbon fiber(CF)hybrid fibers were constructed using electrophoretic deposition.The interfacial properties of CF/epoxy and CNT/CF/epoxy composites were statistically investigated and compared using in-situ thermal Raman mapping by dispersing CNTs as a Raman sensing medium(CNT_(R))in a resin.The associated local thermal stress changes can be simulated by capturing the G'band position distribution of CNT_(R) in the epoxy at different temperatures.It was found that the G'band shifted to lower positions with increasing temperature,reaching a maximum difference of 2.43 cm^(−1) at 100℃.The interfacial bonding between CNT/CF and the matrix and the stress distribution and changes during heat treatment(20-100℃)were investig-ated in detail.This work is important for studying thermal stress in fiber-reinforced composites by in-situ thermal Raman mapping technology.

岩体初始地应力场边界模拟方式探讨

针对某水电站地下厂房地下洞室群的地形地质条件,在边界上施加分布位移与分布面力两类不同边界条件下,采用7种方案模拟构造应力场,对其初始地应力进行了多元回归计算,并对回归结果进行了比较分析。结果表明:相对于在边界上施加位移的方案,在边界上施加分布面力的方案对x、y向面力分布形式的变化较敏感;在边界上施加均布位移的方案操作简单,模拟效果较好比较适合于区域性地层较平缓、岩体状况较好的工程条件。

Development of a distributed and integratable manufacturing execution system framework

Using remote method invocation (RMI) and a distributed object-oriented technique, this paper presents a systematic approach to developing a manufacturing execution system (MES) framework, which is open, modularized, distributed, configurable, interoperable and maintainable. Moreover, the design patterns for the framework .are developed and a variety of functional components are designed by inheriting appropriate patterns. And then an application is constructed by invoking corresponding methods of related components. An MES system implementing the framework and design patterns can be facilely integrated with other manufacturing applications, such as enterprise resource planning (ERP) and floor control system (FCS) .

Analytical Model of Surface Field Distribution and Breakdown Voltage for RESURF LDMOS Transistor

An analytical model of the surface field distribution and breakdown voltage of the reduced surface field lateral double diffusion MOS transistor is proposed.Based on the 2-D Poisson's equation solution,the derived model gives the closed form solutions of the surface potential and electrical field distributions as a function of the structure parameters and drain bias.A criterion for obtaining the optimal trade-off between the breakdown voltage and on-resistance is also presented to serve to quantify the maximum breakdown voltage and optimal relations of all design parameters.Analytical results are shown in good agreement with the numerical analysis obtained by the semiconductor device simulator MEDICI and previous reported experimental data.

A Novel Analytical Model for Surface Electrical Field Distribution and Optimization of TFSOI RESURF Devices

A novel analytical model for the thin film silicon on insulator (TFSOI) reduced surface field (RESURF) devices has been proposed.Based on the 2-D Poisson equation solution,the analytical expressions for the surface potential and field distributions are derived.From this analysis,the optimum design condition for the maximum breakdown voltage is obtained.The dependence of the maximum breakdown voltage on the drift region length is examined and the relationship between the critical doping concentration and the front- and back- interface oxide layer thickness is discussed.The numerical simulation performed by the advanced semiconductor simulation tool,DESSIS-ISE,has been shown to support the analytical results.

Vertical distribution of the Kuroshio velocity in the Pollution Nagasaki section and its formative mechanism

The seasonal and interannual variations of the vertical distribution of the Kuroshio velocity and its formative mechanism were studied by analyzing the Global Ocean Reanalysis Simulation 2 （GLORYS2） dataset in the Pollution Nagasaki （PN） section （126.0°E-128.2°, at depths less than 1000 m）. The results indicated that： 1） the maximum transport in the PN section occurs in summer, followed by spring, and the minimum transport occurs in fall and winter; the maximum velocities are located at the subsurface in both winter and summer and velocities are relatively larger and at a shallower depth in summer; and the velocity core is located at the surface in spring and fall. The isopycnic line has a clear depression around the Kuroshio axis in winter. The depth of maximum velocity and the zero horizontal density gradients both exhibit substantial seasonal and interannual variations, and the interannual variations are larger. 2） The distributions of velocity and density are in accordance with the therma~ wind relation. Although Kuroshio transport is determined by the large-scale wind field and mesoscale motion in the Pacific Ocean; local heat flux and thermohaline circulation influence the density field, modify the vertical structure of the Kuroshio velocity, and adjust the allocation of water fluxes and nutrients transport. 3） Shelf-water offshore transport into the Kuroshio upper layer induced by southwest monsoons might contribute to the maximum velocity up to the surface in summer. Nonlinear and nongeostrophic processes are not considered in the present study, and the thermal wind relation accounts for part of the vertical structure of the Kuroshio velocity.

Effect of reagent films on coupling relationship between glass surface and particles

The experiments were conducted to investigate the behavior of airborne particles adhering to the glass slides which were coated by several reagent films. The results showed that the adhesion level could be significantly changed by the reagent films. There were no evident rules between the average size of particles and sampling time interval, the placing angle and reagent concentration. The average particle size on the surface coated by composite reagent （2-3 μm） was smaller than that on the single reagent coated surface, while the largest particle size （4-5 μm） was observed on the surface coated with the Tween 60. The experiment also demonstrated that the best adhesive performance was obtained on the surface which was coated with 0.5% SDBS and 0.5% fluorocarbon composite reagents. The experiment results indicated that each reagent had a certain optimum adhesive range to the particle. The composite reagents with different proportion of single reagents exhibited some particular physical and chemical properties, which could effectively change the adhesive performance between the solid surface and the particles.

Methods of Random Fatigue Design for Vehicle Transmission System Components

Some representative working conditions were measured, and the amplitude distribution rule of each representative working condition after analysis of measured data was got. The building of 2 D distributing function between the range and the mean of random load was discussed. Experiment was carried out to get the fatigue strength data of the material of transmission component. Accessing the P S a S m N camber of combined load of bending and torsion on this material after analysis. And the process of calculating the 2 D fatigue life in multi working condition was discussed.

Energy Dependence of Interface Trap Density——Investigated by Relaxation Spectral Technique

According to the definition of interface traps,a new application of relaxation spectral technique to sub-threshold swing shift and sub-threshold gate voltage shift is proposed to extract interface trap density in 1.9nm MOSFET.And thus the energy distribution of interface trap can be determined.According to the two methods,the energy profile of interface traps agrees with those reported in literature.Compared to other methods,this method is simpler and more convenient.

Present status and conservation strategies of mangrove resource in Guangdong, P. R. China

According to the survey of Guangdong mangrove resource in 2001 and authors field investigations in the past 5 years, the total mature mangrove land area of Guangdong Province was estimated at 9084 hm2, accounting for 41.4% of total mangrove land area of China. These mangrove forests totally consisted of 50 species belonging to 28 families, distributed at more than 100 locations along the coastlines of Guangdong and most of them present a high dense and dwarf appearance. The Ass. Avicennia marina is the most dominant mangrove association. The investigation results showed that the mangrove forests with coverage rates above 0.7 accounted for 68.0% of the total mangrove land area of the province and 77.8% of mangrove forests was less than 2 m in tree height. Since 1950, 54.6% of mangrove forests have disappeared due to paddy rice reclaim, aquaculture and city constructions. Derivational conservation efforts are still weakly empowered and should be strengthened intensively. The author suggested that mangrove laws and regulations should be enforced, mangrove scientific research should be strengthened; and mangrove conservation awareness of local community should be raised on conservation of mangroves.

A model study of residual oil distribution jointly using crosswell and borehole-surface electric potential methods

Although high resolution can be provided by electrical logging, the measured electrical log range is narrow and is limited to near the well. Borehole-surface electric potential measurements are able to detect a wide enough range but its resolution is limited, particularly for reservoirs with complex oil and water distribution or complicated structure. In this study, we attempt to accurately locate the 3-D reservoir water and oil distribution by combining borehole-surface and crosswell electric potentials. First, the distributions of oil and water in both vertical and horizontal directions are detected by the borehole-surface and erosswell electric potential methods, respectively, and then the measured crosswell potential result is used to calibrate the measured borehole-surface electric potential data to improve vertical resolution so that the residual oil distribution is determined in a lower half-space with three dimensions. The evaluation of residual oil distribution is obtained by investigation of differences between the simulation results of the reservoir with and without water flooding. The finite difference numerical simulation results prove that the spatial residual oil distribution can be effectively determined by combining the crosswell and borehole-surface electric potentials.

Comparative Efficacy and Distribution of Evans Blue Liposome Modified with DSPE-PEG,Tween80,and Brij35

Aim To improve the stability and optimize the tissue distribution of Evans blue liposome in rats, some surfactants such as DSPE-PEG, Tween80, and Brij35 were used to modify the Evans blue liposome. Methods The Evans blue liposome was prepared by the reverse-phase-evaporation method. The effect of cholesterol on the encapsulation percentage of Evans blue was studied. The effects of DSPE-PEG, Tween80, and Brij35 on the encapsulation percentage and tissue distribution of Evans blue liposome in the rat were determined. Results The top encapsulation percentage of Evans blue liposome is 25.30%. After modification by DSPE-PEG, Tween80, and Brij35, the encapsulation percentages decreased slightly, but not significantly. After modification, the Evans blue concentrations deceased in the liver, spleen, lung and kidney, but increased in the brain, especially in the EB-L-Tween80 group. Conclusion DSPE-PEG, Tween80, and Brij35 have slight effect on the encapsulation percentage of Evans blue liposome. The effect of Brij35 on the distribution of Evans blue liposome is similar to that of DSPE-PEG because they both is prevent the reticuloendothelial system (RES) from clearing liposome. The Evans blue concentration in the brain is greatly improved when Tween80 is used to modify the EB liposome, which is good information for preparing liposome targeting the brain.

CUTTING TEMPERATURE MEASUREMENT IN HIGH-SPEED END MILLING

A computer aided measurement system is used to measure the cutting temperature directly in high-speed machining by natural thermocouples and standard thermocouples. In this system the tool/workpiece interface temperature is measured by the tool/workpiece natural thermocouple, while the temperature distribution on the workpiece surface and that of interior are measured by some standard thermocouples prearranged at proper positions. The system can be used to measure cutting temperature in the machining with the rotary cutting tools, such as vertical drill and end milling cutter. It is practically used for the research on high-speed milling with hardened steel.

Developmental Mechanism and Distribution Pattern of Stomatal Clusters in Begonia peltatifolia

The function of stomata in plants is controlling gas exchange and modulating water balance. The distribution pattern of stomata in most vascular plants follows a certain regulation with at least one normal epidermal cell between two stomata. However, some plants restricted in several genera of vascular plants have stomatal clusters in which more than one stoma is adjacently arranged with no epidermal cells among them. The developmental process of stomatal clusters in plants, especially in non-mutant (wild type) vascular plants, has rarely been documented, and very few studies concerning the distribution pattern of stomatal clusters on leaf epidermis have been carried out. We reported the developmental mechanism and distribution pattern of stomatal clusters in Begonia peltatifolia Li native to China. The results indicated that the clustered arrangement of meristemoids at the juvenile stage of the leaf development contributed greatly to the pattern of stomatal clusters. Additionally, satellite meristemoids derived from subsidiary cells around the mature stomata also had an impact on the development as well as the pattern of stomatal clusters. Regarding stomatal cluster and singly occurring stoma both as a stomatal unit, we found that the stomatal unit density (i.e., number of stomatal unit per area) increased gradually from the middle part to the edge and the apex of the leaf, while stomatal unit size (i.e., number of stomata per stomatal unit) decreased. The possible reason of this pattern was discussed.

Ionic Distribution, Electrostatic Potential and Zeta Potential at Electrochemical Interfaces

Density functional theory is applied to predicting the structures and electrostatic potentials of planar electrochemical surfaces within the framework of the restricted primitive model where small ions are represented by charged hard spheres of equal diameter and the solvent is assumed to be a continuous dielectric medium. The hard-sphere contribution to the excess Helmholtz energy functional is evaluated using the modified fundamentalmeasure theory and the electrostatic contribution is obtained from the quadratic functional Taylor expansion using the second-order direct correlation function from the mean-spherical approximation. Numerical results for the ionic density profiles and the mean electrostatic potentials near a planar surface of various charge densities are in excellent agreement with molecular simulations. In contrast to the modified Gouy-Chapman theory, the present density functional theory correctly predicts the second layer formation and charge inversion of charged surfaces as observed in simulations and in experiments. The theory has also been tested with the zeta potentials of positively charged polystyrene particles in aqueous solutions of KBr. Good agreement is achieved between the calculated and experimental results.

Wet Oxidation of Al_x Ga_(1-x)As/GaAs Distributed Bragg Reflectors

The wet oxidation of AlGaAs with high Al content in a distributed Bragg reflectors （DBR） is studied by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Some voids distribute along the oxide/GaAs interfaces due to the stress induced by the wet oxidation of the AlGaAs layers. These voids decrease the shrinkage of the Al2O3 layers to 8% instead of the theoretical 20% when compared to the unoxidized AlGaAs layers. With the extension of oxidation time, the reactants are more completely transported to the front interface and the products are more completely transported out along the porous interfaces. As a result,the oxide quality is better.

Effect of cooling structure on thermal behavior of copper plates of slab continuous casting mold

A three-dimensional finite-element model of slab continuous casting mold was conducted to clarify the effect of cooling structure on thermal behavior of copper plates. The results show that temperature distribution of hot surface is mainly governed by cooling structure and heat-transfer conditions. For hot surface centricity, maximum surface temperature promotions are 30 ℃and 15 ℃ with thickness increments of copper plates of 5 mm and nickel layers of 1 ram, respectively. The surface temperature without nickel layers is depressed by 10 ℃ when the depth increment of water slots is 2 mm and that with nickel layers adjacent to and away from mold outlet is depressed by 7℃ and 5 ℃, respectively. The specific trend of temperature distribution of transverse sections of copper plates is nearly free of cooling structure, but temperature is changed and its law is similar to the corresponding surface temperature.