电子商务领域内潜在客户的识别方法

对于电子商务领域内的企业而言,其潜在客户可从浏览本企业站点的参观者中确定.本文针对电子商务领域内企业潜在客户确定问题,根据该类企业甄选潜在客户的途径和特点,运用可能性理论,提出了一种有效而方便的潜在客户识别与选择的方法,为该类企业选择理想的潜在客户提供理论依据.最后给出一个算例.     

变电站接地网优化设计

在不等电位数学模型下,以网内最大接触电压差为目标函数,使用接地网工频参数计算软件得到了一种均匀土壤结构下接地网导体最优布置方案。优化结果表明,与DL/T621-1997中给出的接地网不等间距布置相比较,故障电流入地点处导体得到了充分利用,相应地减小了边缘导体泄漏电流,改善了土壤表面的电位分布,使接地系统的安全性得到明显提高。     

土壤电阻率对罐底外侧阴极保护电位分布的影响

建立了罐底外侧阴极保护电位分布的数学模型,模型中考虑了介质的不均匀性。利用数值模拟方法研究了罐底土壤电阻率沿垂直方向变化对电位分布的影响。结果表明:罐底沥青砂基础会加大电位分布的不均匀性;阳极埋深处的土壤电阻率对整个罐底的电位均有显著影响;在不同地质条件下进行深井阳极保护时,存在一个使电位分布效果最佳的阳极埋深点。     

本溪市城市街道灰尘中重金属污染特征及评价

采用X射线荧光光谱法探究了城市不同功能区街道灰尘重金属（Cu、Pb、V、Zn、Cr、Mn）空间分布特征与潜在生态风险。对本溪市文教区、商业区、居民区、工业区、交通区和混合区街道灰尘样品中的重金属含量进行了分析。结果表明，街道灰尘中重金属Cu、Pb、V、Zn、Cr、Mn平均质量分数分别为本溪市土壤环境背景值的3.4、3.1、0.9、5.5、2.0、1.0倍；Cu、V、Cr在文教区质量分数最高，Cr、Mn在商业区质量分数最低，V在居民区质量分数最低，Pb、Zn、Mn在工业区质量分数最高，Cu、Pb、Zn在混合区质量分数最低。应用潜在生态危害指数法评价的结果表明，本溪市街道灰尘中的重金属达到重污染水平，具有严重的潜在生态危害，其中，V、Cr、Mn属于低潜在生态危害，Zn属于中等潜在生态危害，Cu、Pb达到了重潜在生态危害。     

Method to determine electrochemical potential gradients without reinforcement connection in concrete structures

A suitable condition assessment of a structure is usually based on comprehensive non-destructive measurements to locate the relevant critical areas. Electrochemical potential mapping is an approved method to detect areas with a high risk of chloride induced corrosion in concrete structures. A novel approach has been developed to locate critical areas without a reinforcement connection by using three external electrodes. As result a vector is calculated which points directly to the critical area near the sensor position, comparable with a compass. This method allows an immediate identification of critical areas on site. In this paper the methodology is explained and measuring results are compared to the conventional method.     

On the implementation of 3D Galerkin boundary integral equations

In this article, a reverse contribution technique is proposed to accelerate the construction of the dense influence matrices associated with a Galerkin approximation of hypersingular boundary integral equations of mixed-type in potential theory. In addition, a general-purpose sparse preconditioner for boundary element methods has also been developed to successfully deal with ill-conditioned linear systems arising from the discretization of mixed boundary-value problems on non-smooth surfaces. The proposed preconditioner, which originates from the precorrected-FFT method, is sparse, easy to generate and apply in a Krylov subspace iterative solution of discretized boundary integral equations. Moreover, an approximate inverse of the preconditioner is implicitly built by employing an incomplete LU factorization. Numerical experiments involving mixed boundary-value problems for the Laplace equation are included to illustrate the performance and validity of the proposed techniques.     

四川盆地三叠系天然气地球化学特征及资源潜力分析

简要介绍了四川盆地三叠系的总体勘探形势,认为该层系资源发现率和探明率不高,仍具有很好的勘探前景。通过分析四川盆地三叠系天然气的地球化学特征,指出该层系可划分为2个含油气系统,即志留系—中三叠统含油气系统和上三叠统—侏罗系含油气系统。通过研究四川盆地三叠系烃源岩地球化学特征、生气强度、展布特征等，定量评价出该层系油气资源总量为8.01×10¹²m³，同时指出了该层系天然气有利勘探领域。     

Shil’nikov chaos in the oxidation of formic acid with bismuth ion on Pt ring electrode

We report experimental observations of potential oscillations in electrocatalytic oxidation of formic acid with bismuth ion on the Pt ring electrode. Potential oscillations were investigated under galvanostatic conditions. The presence of bismuth ion enables to get the low and stable potential values at larger current range. Periodic and Shil’nikov chaotic potential oscillations were observed at fixed current. To extract information from the oscillation pattern, we used time series, reconstructed attractor, next-maximum map, pattern formation of interfacial potential above ring electrode.     

松辽盆地油气勘探成果与潜力分析

本在总结松辽盆地勘探成果的基础上，对松辽盆地的勘探潜力进行了分析，提出了下步勘探地区和应发展的勘探技术。     

Study of grain boundaries influence on electrical properties of nitrides

The electronic conduction mechanism through grain boundaries in heteroepitaxial gallium nitride layers was explained by applying the model, which included three effects: thermionic emission over potential barrier, thermionic field emission through potential barrier and thermionic field emission through scattering barrier. Space charge potential barriers height at the grain boundary layer was estimated to be 80 meV from the measurement of the temperature dependence of layer resistivity. Influence of the deep traps location in the different regions of active layers of the MSM detector on the device performance was evaluated by 2D numerical simulation.