自由口通信模式下计算机读写PLC存储区的程序设计

本文介绍了在自由口通信模式下，用计算机读写S7—200PLC存储区内相邻的多个字节数据的通信程序设计方法，程序设计中采用了多种可靠性措施。     

EXPERIMENTAL INVESTIGATIONS ON LONGITUDINAL DISPERSION CHARACTERISTICS OF TIDAL RIVERS

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＵｎｄｅｒｔｈｅｉｎｆｌｕｅｎｃｅｏｆｎａｔｕｒａｌｔｉｄｅｓ,ｔｈｅｉｎｔｅｒａｃ ｔｉｏｎｓｂｅｔｗｅｅｎｆｌｏｗｆｅａｔｕｒｅｓａｎｄｐｏｌｌｕｔａｎｔｌｏｎｇｉｔｕｄｉｎａｌｄｉｆｆｕｓｉｏｎｉｎｔｉｄａｌｒｉｖｅｒｓａｒｅｉｍｐｏｒｔａｎｔｆｏｒｗａｔｅｒｅｎｖｉ ｒｏｎｍｅｎｔｒｅｃｔｉｆｉｃａｔｉｏｎｉｎｅｓｔｕａｒｉｎｅｒｅｇｉｏｎｓ.Ｔｈｅｄｉｆｆｕ ｓｉｏｎａｎｄｔｒａｎｓｐｏｒｔｏｆｐｏｌｌｕｔａｎｔｉｎｎａｔｕｒａｌｒｉｖｅｒｓｆａｌｌｉｎ ｔｏｍ…     

基于嵌入式以太网的异步电机矢量控制系统体系结构设计

为了实现异步电机现场控制与上层管理的无缝集成，提出在通用变频器一异步电动机调速系统的基础上，采用基于ARM7TDMI核的微控制器和以太网控制芯片，实现异步电机的网络化控制。详细介绍了该系统的体系结构设计方案。     

An Interval Fuzzy Multiobjective Watershed Management Model for the Lake Qionghai Watershed, China

Integrated watershed management is required to ensure the reasonable use of resources and reconcile interactions among natural and human systems. In the present study, an interval fuzzy multiobjective programming (IFMOP) method was used to solve an integrated watershed management problem. Based on system analysis, an IFMOP model suitable for a lake watershed system {IFMOPLWS} was developed and applied to the Lake Qionghai watershed in China. Scenario analysis and an interactive approach were used in the solution process. In this manner, various system components were incorporated into one framework for holistic consideration and optimization. Integrality and uncertainty, as well as the multiobjective and dynamic characteristics of the watershed system, were well addressed. Using two scenarios, two planning schemes were generated. Agriculture, tourism, macroeconomics, cropland use, water supply, forest coverage, soil erosion, and water pollution were fully interpreted and compared to identify a preferable planning alternative for local agencies. This study showed that the IFMOPLWS is a powerful tool for integrated watershed management planning and can provide a solid base for sustainable watershed management.     

一种增强型冲突分解算法

冲突分解算法是一种能有效改善无线信道多址接入协议的方式。本文对传统的冲突分解算法——树形冲突分解算法和先到先服务冲突分解算法进行了深入研究和仿真，探讨了这两种算法的优点和不足之处，提出了一种增强型的冲突分解算法（Enhanced Splitting Algorithm，ESA）。该算法继承了树形冲突分解算法和先到先服务算法的优点，不仅考虑了碰撞分组产生的时间，还考虑了分组的产生间隔，从而有效地提高了冲突分解算法的性能。仿真结果显示ESA算法是一种可行的算法。     

Traction-based Completed Adjoint Double Layer Boundary Element Method in elasticity

This paper is concerned with a traction-based Completed Adjoint Double Layer Boundary Element Method to solve for the surface traction of a system of rigid particles embedded in an elastic matrix. The main feature of the method is a single layer representation of the displacement field, which leads to a system of second-kind integral equations for the traction field, the extreme eigenvalue of which could be deflated, allowing iterative solution strategies to be effectively applied. The method is therefore most suitable for large-scale simulations of particulate solids. The method is benchmarked against some known analytic solutions, including the difficult stress singularity problems at sharp edges. The effectiveness of the method in dealing with a large number of inclusions is also demonstrated with an elongational deformation problem involving up to 25 inclusions.Research supported by the Australian Research Council (to NP-T and X-JF) and the National Natural Science Foundation of China (X-JF).     

基于eZ publish的网站实现方法

eZ publish系统是一种新型的PHP开发框架，其网页模板TPL机制可用于快速地开发网站。本文说明了笔者对eZ publish系统的改进与扩充，以及如何利用这个改进的系统去构建一个大型的专业网站，以实现美工和程序的分离，降低网站开发与维护的成本。     

浅析循环流化床锅炉尾部受热面的磨损

分析循环流化床锅炉尾部受热面的磨损，采取防磨措施，减缓磨损。     

Imaging of follicular dendritic cell tumours of the liver

Follicular dendritic cell tumour of the liver is a recently recognized entity. To date, only two cases have been described, both in the pathology literature. Histologically, it resembles an inflammatory pseudotumour and immunohistochemical and ultrastructural studies are required for its diagnosis. The ultrasound, computed tomography and angiographic features of two cases of follicular dendritic cell tumour of the liver are described in detail. One of the patients had multiple recurrences of this tumour. The imaging features are very similar to those of hepatocellular carcinoma. As follicular dendritic cell tumour is considered to be of low-grade malignant potential, in contrast to the dismal prognosis for hepatocellular carcinoma, it is important to be able to accurately distinguish between the two types of tumour prior to initiating definitive therapy.