无线HART网络管理器的研究与实现

工业无线网络技术是继现场总线之后，工业控制领域的又一个热点技术，是降低工业测控系统成本、提高工业测控系统应用范围的革命性技术。无线HART规范作为第一个开放的工业无线网络国际标准，在满足工业应用苛刻的可靠性、实时性和安全性等关键需求的同时，还提供良好的向后兼容性，具有广阔的应用前景。网络管理器是无线HART网络的核心设备，是无线HART规范研究与开发的重点和难点。 本文在对工业无线网络技术、无线HART协议及其关键技术、无线HART网络管理器进行详细总结的基础上，从核心算法、软件的设计与实现等方面对无线HART网络管理器进行了研究，取得以下成果： (1)提出了一种基于有向图的独立多路径路由算法。算法包括路由发现和路由计算两个过程。路由发现中提出了基于负载均衡和信号强度的邻居过滤，以及邻居冗余等机制，保证了网络可靠性，降低了算法开销。路由计算中提出了基于双向链路筛选的拓扑构建，基于改进Dijkstra算法的最短路径生成，以及基于启发式搜索的独立多路径筛选等机制，满足了工业应用可靠、实时、低开销和低能耗等性能要求。 (2)提出了基于均衡搜索的通信资源分配算法。采用动态的信道黑名单技术，提高了网络的可靠性；保证所分资源均匀分布在搜索空间中，提高了算法应对网络动态性的能力；与主通信资源反序的冗余通信资源搜索过程，使得不同节点的资源均衡，保证了通信资源分配的公平性。此外，该算法还具有轻型、实时等优点。 (3)设计和实现了无线HART网络管理器软件。针对网络管理器功能复杂，性能要求高等问题，本文采用模块化软件设计方法设计和实现了无线HART网络管理器软件，并将其应用于辽宁省一大型纸业有限公司75吨流化床温度与压力监测系统中。网络管理器长期稳定运行、性能良好的事实表明了设计与实现的合理性。

凝析天然气管道分层流动相间水力摩阻系数计算式评价

前人已经得出了许多计算分层流动相间水力摩阻系数的经验、半经验半理论的公式.然而,由于它们多是以室内小型实验架上得到的数据为基础,虽然与各自的实验结果符合较好,但是普遍存在适用范围窄、精度低的缺陷.获得了大型多相流环道上的实验数据,并利用这些数据对部分常用的经验公式进行了评价.依据评价结果认为,当气相速度低于15 m/s时,依据Chen等人的关联式的计算值与实验结果比较接近,误差不超过13.2％;当气相速度大于15 m/s时,Hart等人的模型预测值与实验结果符合较好,误差普遍介于0～15.94％之间.因此

用ANUDEM建立水文地貌关系正确DEM的方法研究

针对区域尺度的径流、水土流失定量评价和植被适宜性评价等研究工作需要,利用1∶25万数字地形图和ANUDEM软件,对黄土丘陵区中等分辨率水文地貌关系正确DEM建立方法进行了研究。结果表明该方法所建立的DEM,可以正确反映地貌梁、沟结构及其与流水线网络的关系,对地形描述的能力优于TIN方法建立的DEM;利用ANUDEM和1∶25万地形图插值建立黄土丘陵区DEM的三个主要参数分别为分辨率50或100,计算迭代次数40,第二糙率系数0.8。

苯基稀土氯化物的合成及其表征

1970年,Hart等首先合成了Sc(C_6H_5)_3、Y(C_6H_5)_3、LiLa(C_6H_5)_4和LiPr(C_6H_5)_4。1972年,Cotton等测定了[Lu(2,6-(CH_3)_2C_6H_3)_4]·[Li·4THF]的晶体结构。1986年,陈文启等人合成了Nd(C_6H_5)_3,Gd(C_6H_5)_3和LiNd(C_6H_5)_4。本文首次合成了苯基稀土氯化物C_6H_5LnCl_2·nTHF(Ln=Pr,Sm,Gd,n=3,4);C_6H_5LnCl_2·LiCl·nTHF(Ln=Pr、Nd、Sm、Gd,n=2、3、5);(C_6H_5)_2GdCl·LiCl·2THF;[(C_6H_5)_2NdCl]_2·LiCl·4THF。测定了C_6H_5GdCl_2·4THF的晶体结构。

SYNTHESIS OF [LI.3DME] [(ETA-5-C5H5)3NDC6H5]

The phenyl derivatives of lanthanides Sc(C_6H_5)_3, Y(C_6H_5)_3, LiLa (C_6H_5)_4 and LiPr(C_6H_5)_4 were prepared by Hart et al. in 1970, and dis(cyclopentadienyl) phenyl complexes of lanthanides have been isolated recently. We reported here the synthesis and crystallography parameters of a new type of phenyl derivative of neodymium:

四苯基丁二烯基稀土化合物的合成及其对丁二烯聚合的催化活性

稀土碳π键型化合物已得到广泛研究,而稀土碳σ键型化合物的合成却报道得较少。1970年Hart等人首次报道了稀土碳σ型化合物LiLn(C_6H_5)_4(Ln=Sc,Y,La,Pr)的合成,1981年Evans等人合成了稀土碳σ键型化合物[(C_5H_5)_2LnC(CH_3)_3](THF)(Ln=Er和Lu)。我们合成了如下两种新型四苯基丁二烯基稀土σ键化合物。相似的d-类化合物的晶体结构证实金属碳键为σ键型。研究了(Ⅰ)中的Nd化合物与三乙基铅配合对丁二烯聚合的催化活性。

一种面向无线传感器网络协同任务分配的动态联盟更新机制

在面向目标追踪等应用的无线传感器网络研究中,协同任务分配机制的研究是很重要的。基于动态联盟机制的协同任务分配方法是事件触发的,适用于任务出现频率相对较低的大规模无线传感器网络。本文在基于动态联盟机制研究的基础上,首先引入了联盟覆盖范围和休眠盟员的概念,进一步消除针对同一任务的检测传感器节点的冗余,降低系统的能量消耗;而后又给出了一种动态联盟的更新机制,以保证动态联盟执行任务时的连续性,在一定程度上保证网络的检测性能。最后通过仿真,从系统总能耗、目标捕获率和检测误差标准差等方面检验了算法的性能,并给出了缓冲带宽度等参数对能耗和网络检测性能的影响。

加工深度、记忆材料类型对FOK和FOnK判断的影响

Predecessors’ research found that feeling-of-knowing and feeling-of-not-knowing was two different cognitional processes. Processing depth had more good effects on FOK judgment, but it had little effects on FOnK judgment, furthermore, it perhaps decreased the accuracy of FOnK judgment. On the base of predecessors’ research the experiment discussed the different effects on FOK judgment and FOnK judgment by processing depth and memory materials of different kinds. The first purpose was to find that the effects of processing depth on FOK judgment and FOnK judgment were different or not. The second purpose was to reveal the two different memory materials of the Paired-Chinese-words and the Paired- Chinese-phonetic-alphabet would cause difference on the grade and accuracy of FOK judgment or not, and if the two different kinds of memory materials took different effects on FOK judgment and FOnK judgment. The third purpose was to search if there was interaction on processing depth and different kinds of memory materials. The experiment used the Paired-Chinese-words and the Paired- Chinese-phonetic-alphabet as the materials, and regarded processing depth in the time of encoding stage and different kinds of memory materials as the independent variable. The experiment regarded validity of memory; the grade of FOK judgment; the accuracy of FOK judgment; the accuracy of FOnK judgment as the dependent variable. The experiment adopted the “RJR” normal researching form of FOK judgment projected by Hart. The result of the researching proved that in the condition of deep processing in the time of encoding stage, the validity of memory; the grade of FOK judgment; the accuracy of FOK judgment were higher than in the condition of superficial processing, but processing depth had little effect on accuracy of FOnK judgment. FOK judgment and FOnK judgment were two different cognitional processes. Memory materials of different kinds led clear difference on the dependent variable of the validity of memory; the grade of FOK judgment; the accuracy of FOK judgment, and also had little effect on accuracy of FOnK judgment. Processing depth and different kinds of memory materials had interaction on their effects on FOK judgment. Regard the accuracy of recall, the percentage of “feeling of knowing”, the percentage of “feeling of not knowing”, and the grade of FOK judgment as the dependent variables, memory materials of different kinds make little effect in the condition of superficial processing in the time of encoding stage, but in the condition of deep processing in the time of encoding stage, Chinese characters was higher than Chinese phonetic alphabet.