PLC在林业育苗温室中的应用

温室设计是林木种苗示范基地建设中的关键。本文在讨论育苗温室控制功能要求和松下电工FP0系列微型PLC配套单元技术性能指标的基础上,着重探讨了PLC模拟单元输入口共享技术方案。它对降低温室数据采集成本,对育苗自动化技术的推广和普及都有现实意义。     

黑脸琵鹭在海南岛的越冬地及其保护

于2003、2004和2005年连续3年对黑脸琵鹭在海南岛已知和潜在的越冬地进行调查.分别在东寨港自然保护区、临高县后水湾和东方市北黎湾发现了黑脸琵鹭的越冬种群,后两者是在海南岛首次记录到.2005年海南岛黑脸琵鹭的越冬种群数量已达77只,约占全球越冬种群数量的5%以上,这是继香港和台湾等地之后黑脸琵鹭在中国的又一重要越冬地.调查结果表明:黑脸琵鹭越冬栖息地所面临的主要威胁是湿地滩涂的围垦、海产品挖采和非法猎捕.建议有关职能部门采取有效措施,分别在2个新发现地建立保护机构,并对越冬地周围的村民进行保护意识教育和宣传,以加强黑脸琵鹭及其栖息地的保护与管理.     

4气门柴油机进气道的设计模拟及试验匹配研究

通过对国内外多种机型4气门柴油机进气道进行试验和数据分析,并结合自主开发4气门柴油机进气道的实践经验,提出了4气门柴油机进气道的性能影响因素和设计要点,为4气门结构更广泛地应用在国产柴油机上提供有益的借鉴。     

To Use Virtual x Driver to Realize Interruption Serial Communication

How to develop Virtual x Driver(VxD) in windows system bottom layer is given to realize high efficiency interrupt communication of serial port. By analyzing Virtual x Driver, Programable Interrupt Controller, how to virtually a interruption is proposed. With the operational principle of UART chip 8250, the communication of serial port is analyzed. Finally, the communication between WIN32 application and VxD is discussed, and the constitute of the VxD is given. The applied solid example expresses that method of the serial port communication is efficient.     

Study on Application of Protocol Analysis in Attack of ICMP

In this paper, the encapsulation of ICMP packets and the specifications of IP packet, ICMP packet and UDP packet are introduced. At the angle of the protocol analysis, a ICMP attack case is described the characters of attack are abtained and the corresponding countermeasures are presented.     

Optimization of Helix Intake Port Based on Numerical Simulation

With numerical simulation, an analysis is done on the three-dimension air flow in the helix intake port of a diesel engine. The anthors acquire the distribution of characteristic parameters of air in the port, such as velocity, pressure, turbulence kinetic energy, as well as the flow coefficient and rotate moment around the erect axes at the outlet. The results of simulation indicate that the negotiability of the port is very good while the ability of forming eddy can be enhanced, so several improve measures have been put forward. Comparing with simulation results of these measures, it finds out that the method of combining increase the distance between the definition curve of volute cavity and central line of valve protruding support as well as increase the eddy shell angle can obviously enhance the ability of forming eddy, which is an efficient and rational method.     

Surface Reconstruction and Modification of Port-Combustion Chamber Structure for a Gasoline Engine

Geometry of port-combustion chamber has an important effect on the performance of gasoline engines. Methods and approaches in reverse engineering are introduced into surface reconstruction and modification of a port-combustion chamber structure. Free-form surfaces of the port-combustion chamber structure for a gasoline engine with 4-valves and dual-ball type combustion chamber are successfully reconstructed in the reverse way through data processing, surface modeling, surface verifying, surface re-modeling and smooth evaluating etc., based on laser-scanned point cloud data of a sample work piece. It lays a foundation for imitation innovation of gasoline engine by changing the local structural characteristics and dimensions of a prototype model.     

Harmonising sediment criteria of North sea and Rhine river Basin

As a result of convenants between the Port of Rotterdam and the German Chemical Industry, the emissions in the Rhine between Basle (Switzerland) and the Dutch boarder have fallen by more than half in the past fifteen years. Recent studies have concluded that people are nowadays polluting the Rhine more than industry. This places Rotterdam’s involvement with the quality of water and the sediment of the Rhine, port and North Sea in a different perspective. As a medium-sized European municipality, Rotterdam doesn’t want to take on too much, certainly not when cross-border issues such as the quality of the North Sea and the Rhine water are concerned. Rotterdam is now trying to get other organisations to co-operate in solving this problem. A cleaner Rhine, after the success on point sources, can be achieved primarily by reducing the contamination from diffuse sources, over which the port itself has absolutely no control. Rotterdam is the homeport of Mrs. Els Kuijper. She gave a keynote lecture during the SedNet Inaugural Conference, April 22–23, 2002, which forms the basis of this article. Mrs. Kuijper is the vice-mayor and environmental alderman of Rotterdam.     

基于上位机控制的喷雾成像装置的研制

研制出一种喷油嘴喷雾成像系统,该系统利用PC机作为上位机,用PC机的串口通信系统发送指令到单片机,单片机接收指令并利用单片机的内部资源和控制电路对外部成像系统的闪光灯和数码照相机进行自动控制,闪光灯闪光时刻是相对于同一基准信号不同循环的延时,可得不同喷雾时刻的图像,从而获得油束发展过程的全部图像。     

水体微生物群落结构的系列选择性培养基扫描法的初步研究

利用选定的系 列选择性培 养基可以较 好地扫描水 体的微生物群 落组成和 群落结 构，我们称之为系列选择性培养基扫描法。该方法可以一次检出 水体常见的微生物菌株， 根据需要鉴定到属或种甚至株系； 可以准确 反映不同株系微生物的数 量， 便于进行 群落结构的分析和研究。利用该方法对一个小水体进行了研究， 系列选择性培养基检出微生物４８ 个菌株， 数量是普通营养肉汤数量的１０ 倍左右， 两者间有较好的相关性。