《楚辞·天问》中的神话传说

中国古代的神话资料,仅存零星片断,散见各书。《楚辞》有深厚的楚国民间歌谣根基,蕴藏着丰富的神话传说,仅以《天问》为例,即可窥其一斑。     

An application of network analysis on tourist attractions: The case of Xinjiang,China

This study constitutes a novel application of network analysis to explore the underlying mechanisms of tourist attraction network informed by tourist flows. Using survey data collected from a sample of 456 tourists visiting Xinjiang, China, the study applies the Quadratic Assignment Procedure (QAP) to test the relationships between region proximity, grade proximity, and tenure proximity, and the attraction network determined by tourists' free choice movements. Results show that while region proximity and tenure proximity among major attractions in a destination were positively related to attraction network, grade proximity was negatively related to the attraction network, indicating that same grade attractions were mostly competing with one another for tourists. The study contributes to the methodological development of social network analysis in tourism and advances understanding of demand-driven network relationships among tourist attractions in a destination. Destination management implications are discussed.     

多层介质频率选择表面的等效电路分析方法

基于数值仿真计算和微波网络理论，提出了一种多层介质中频率选择表面（FSS）等效电路的分析方法。该方法物理过程直观，计算量小，适用于二维任意形状FSS等效电路的精确求解。以方形贴片型FSS为例验证了等效电路模型的准确性，并分析了多层介质对其等效电路参数的影响规律。最后，基于滤波器理论与FSS等效电路模型设计了双层带通型FSS，计算结果表明全波仿真结果与理论计算结果基本一致，为多层FSS的综合设计提供了一种精确设计方法。     

Forecasting technology diffusion: a new generalisation of the logistic model

The present research proposes a new generalisation of the logistic model aiming at technology diffusion forecasting. Regarding criticisms and failures reported in the literature to apply logistic function for long-term forecasting, in our work we focused on short-term accuracy of forecast. To formulate the model, based on mathematical approximation, at first the differential equation governing the diffusion process is found and then by solving the derived differential equation, the forecast function is obtained. In all steps, mathematical tools from numerical analysis are used. We compared the New Generalized Logistic Model with eight of the most renowned models in the literature. The model led to more accurate fits and forecasts than those obtained from other models we applied for comparison.     

Numerical Maximisation of Likelihood: A Neglected Alternative to EM?

There is by now a long tradition of using the EM algorithm to find maximum‐likelihood estimates (MLEs) when the data are incomplete in any of a wide range of ways, even when the observed‐data likelihood can easily be evaluated and numerical maximisation of that likelihood is available as a conceptually simple route to the MLEs. It is rare in the literature to see numerical maximisation employed if EM is possible. But with excellent general‐purpose numerical optimisers now available free, there is no longer any reason, as a matter of course, to avoid direct numerical maximisation of likelihood. In this tutorial, I present seven examples of models in which numerical maximisation of likelihood appears to have some advantages over the use of EM as a route to MLEs. The mathematical and coding effort is minimal, as there is no need to derive and code the E and M steps, only a likelihood evaluator. In all the examples, the unconstrained optimiser nlm available in R is used, and transformations are used to impose constraints on parameters. I suggest therefore that the following question be asked of proposed new applications of EM: Can the MLEs be found more simply and directly by using a general‐purpose numerical optimiser?     

路基稳定性数值分析

本文通过对常见的路基稳定性分析案例进行强度折减法的数值分析,为进一步研究这一方法在路基稳定性分析中的应用奠定基础。     

程序公平对新产品开发成功的影响——跨职能整合的中介作用

本文通过对中外汽车合资企业的实地调研，提出将程序公平引入现有关于跨职能整合与新产品开发成功的模型中，并进一步提出跨职能整合在合资企业程序公平与新产品开发成功关系中的中介作用。通过对获取数据的分析，发现合资企业程序公平不仅可以直接影响合资企业的新产品开发成功，而且也可以通过跨职能整合间接影响新产品开发成功，而跨职能整合在程序公平与新产品开发成功关系中起中介作用。     

基于fluent紊流幂律流体偏心环空数值模拟研究

为解决常规钻井水力学公式对偏心流场计算结果与实际有所差别的问题,揭示大位移井偏心环空水力行为规律,基于fluent软件对幂律钻井液偏心环空紊流流动进行了数值模拟研究,分析偏心度、稠度系数、流性指数、屈服值、钻杆与钻头组合对流动规律的影响.结果表明,随偏心度、稠度系数、流性指数、屈服值、钻杆与钻头尺寸比例的增大,环空中宽间隙处的流速、压力逐渐增大,而窄间隙处的流速、压力逐渐减小.     

国家标准《数值修约规则与极限数值的表示和判定》在车用汽油胶质含量测定中的应用

本文根据胶质含量测定试验方法的要求，以车用汽油中胶质含量（包括未洗胶质含量和溶剂洗胶质含量）测定为例，探讨了0．5单位数值修约、极限数值的表示和判定在胶质含量测定数据处理和结果判定中的应用。目的在于使车用汽油产品检测工作中在数据处理、报告和结果判定方面更加规范和统一。     

深部沿空掘巷窄煤柱合理宽度数值模拟分析

合理的煤柱宽度能够保证工作面巷道的稳定性,改善沿空掘巷维护状况,降低由于矿山压力造成的巷道变形,煤柱宽度的确定对于提高煤柱回收率、保障安全高效的生产起到积极作用。本文针对煤矿沿空掘巷具体生产地质条件,采用数值计算及现场试验相结合的方法,研究了沿空掘巷窄煤柱的合理的煤柱宽度,得到S2105瓦斯排放巷和S2106回风巷之间合理煤柱宽度为8 m,为该矿地质条件下煤柱留设的合理宽度确定提供了理论依据。