交通诱导室外LED显示屏有关问题之浅见

本文探讨了智能交通系统中交通诱导室外LED显示屏的使用功能,对交通诱导室外LED显示屏在实际应用中的有关问题发表了认识和看法。     

瞬态非傅里叶导热效应判据的探讨

讨论了通用傅里叶导热定律的数学模型,推导了半无限大物体在第一类边界条件下的基于非傅里叶导热定律的双曲线型偏微分方程的解析解。通过分析非傅里叶导热定律在瞬态条件下温度分布的变化过程,提出了非傅里叶导热效应的瞬态判据以及非傅里叶导热的作用范围,对研究工程中瞬态导热问题(如激光处理,电子束处理等)有重要意义。     

濮城油田濮67块低渗凝析难动用气藏挖潜技术研究

濮67块具有埋藏深、物性条件差、储量难动用程度低等特点，目前气藏采出程度很低，开发效果差。通过对濮67块天然气储量再认识，落实了该块储量；通过对濮67块各砂组剩余天然气分布规律的研究，明确了剩余气的下步挖潜方向；并开展了配套的剩余天然气挖潜技术研究，通过在生产中应用，取得了较好的增产效果，提高了气藏的采收率。     

The Clausius inequality corrected for heat transfer involving radiation

The objective of this paper is to prove that the Clausius inequality must be re-stated to have general applicability for heat transfer involving radiative fluxes. The integrand (đQ/T) of the Clausius expression applies to heat conduction and convection, but does not hold for most radiative transfer scenarios, with the exception of reversible infinitesimal net blackbody radiation transfer. In other cases involving radiative transfer, the equality holds for a cycle even though irreversible heat addition by radiative transfer occurs. This is without the erroneous presumption of entropy destruction anywhere in the cycle. Thus, the Clausius inequality indicates reversibility for a cycle that includes an irreversible process. Further, in some radiative cases the quantity đQ/T, where T is the boundary temperature, is not the entropy transfer at the system boundary, and in fact, primarily represents entropy production within the system. It is also clear that in another case considered, the quantity đQ/T had no physical meaning whatsoever. Consequently, the Clausius expression has been re-stated so that it is applicable to cycles with processes involving any form of heat transfer. A new integrand (đQ_cc/T + đS_Net,Rad) is presented, allowing the Clausius inequality to generally apply to all heat transfer scenarios. The work in this paper emphasizes the need to re-state other fundamental equations allowing applicability to all heat transfer processes, and draws attention to the unique character of radiative entropy calculations.     

Exoatmospheric interception problem solved using output feedback law

Interception problems are often dealt with by separating guidance and autopilot design. Guidance law can be obtained using optimal control theory and autopilot design is performed on a linearized system. In this paper, we introduce a new approach that determines a global guidance and autopilot law, based on direct output feedback design. Application of this method to exoatmospheric interception problem results in good performances. Extension to endoatmospheric case is under investigation.     

碾压混凝土穿透型诱导缝不同扩展阶段的强度指标试验研究

在不同削弱度碾压混凝土轴拉试件的穿透型诱导缝周围粘贴了应变片，得到在不同应力状态下诱导缝应变发展规律为：在加载初期，离缝端不同距离的应变发展较为均匀，数值上相差不突出；随着荷载的增加，应变开始出现不均匀发展，离缝端越远，应变变化越缓慢；当接近最大荷载的阶段，缝端应变急速发展，试件瞬间断裂。应变从均匀发展变为不均匀发展，实质上隐含了诱导缝起裂、稳定发展、失稳断裂的整个过程，针对这一试验现象，结合断裂力学理论，建立了诱导缝不同开裂阶段的远场温度应力强度指标模型。     

Coupling of free surface and groundwater flows

In this paper we present some preliminary results about the coupling of shallow water equations for free surface flows and Darcy equation for groundwater flows. A suitable set of interface conditions is discussed: the Beavers and Joseph formula for the bottom stress is used. An iterative algorithm to solve the coupled problem is proposed and some numerical results are presented.     

石油企业办社会的“悖理行为”辨疑

企业办社会虽与市场经济的客观要求相悖，但石油企业大量办社会的事实仍揭示了所具备的理性面。认为国家作为不受所有者监督的代理者对石油企业的要求，石油企业的行业特性以及在传统体制下长期运作所成的定热是石油企业办社会的主要原因。     

基于AHP法的主导产业选择研究——以娄底市为例

适时地选择和培育符合经济发展阶段要求的主导产业，对一个地区的发展具有重要的战略意义。采用层次分析法（AHP法）进行工业主导产业选择可以取得比较好的效果。从评价指标的选择、调查表格的设计及统计整理等方面对采用AHP法进行主导产业的选择进行了探讨，并以娄底市为例进行了论证。     

结构滑模控制的一种指数趋近律方法

提出了一种指数趋近律 ,当正常运动段远离切换面时 ,能快速地趋向切换面 ;当运动接近切换面时 ,趋近速度又大大降低。这样与常用指数趋近律相比 ,过渡时间、系统的抖动以及所需控制力都能进一步减小。最后将这一理论应用到三层剪切型框架进行数值模拟 ,振动控制效果明显。