棉田残膜拣拾机工作部件和参数选择初步探讨

地膜栽培技术能提高作物产量,但作物收获后,残留地里的塑膜要及时清除,回收,以免污染土壤和浪费塑料资源。本文重点叙述棉田残膜拣拾机械的主要工作部件,工艺流程及有关设计参数的选择。     

基于全站仪和CASS软件的土石方量计算

土石方量计算是工程设计的一个重要组成部分,计算方法多种多样。文章结合实际建筑工程场地平整,探讨了利用全站仪进行土石方量数据采集和采用CASS软件进行土石方量计算的方法,方法简单适用,以同行供参。     

A Tabu Search Approach for the Prize Collecting Traveling Salesman Problem

The Prize Collecting Traveling Salesman Problem is a generalization of the Traveling Salesman Problem. A salesman collects a prize for each visited city and pays a penalty for each non visited city. The objective is to minimize the sum of the travel costs and penalties, but collecting a minimum pre-established amount of prizes. This problem is here addressed by a simple, but efficient tabu search approach which had improved several upper bounds of the considered instances.     

自动出油排水装置设计理念与应用实验

提出了自动出油排水装置的设计理念,通过对原有收油装置与本设计装置的工艺流程对比分析,验证了此装置设计理念的高效性与环保性及科学性与先进性;通过工业应用实验与统计分析,验证了装置的实用节能性。从而为油田、炼厂、化工厂污水处理或油水储罐系统提供了一种高效、节能、环保的输油设备,该设备可以应用在沉降罐或沉降池中收取油水混合物或两种不溶液体分离后的上层漂浮液体。     

An Algorithmic Framework for the Exact Solution of the Prize-Collecting Steiner Tree Problem

The Prize-Collecting Steiner Tree Problem (PCST) on a graph with edge costs and vertex profits asks for a subtree minimizing the sum of the total cost of all edges in the subtree plus the total profit of all vertices not contained in the subtree. PCST appears frequently in the design of utility networks where profit generating customers and the network connecting them have to be chosen in the most profitable way. Our main contribution is the formulation and implementation of a branch-and-cut algorithm based on a directed graph model where we combine several state-of-the-art methods previously used for the Steiner tree problem. Our method outperforms the previously published results on the standard benchmark set of problems. We can solve all benchmark instances from the literature to optimality, including some of them for which the optimum was not known. Compared to a recent algorithm by Lucena and Resende, our new method is faster by more than two orders of magnitude. We also introduce a new class of more challenging instances and present computational results for them. Finally, for a set of large-scale real-world instances arising in the design of fiber optic networks, we also obtain optimal solution values. Received: April, 2004 This work has been partly supported by the RTNADONET, 504438, by the Doctoral Scholarship Program of the Austrian Academy of Sciences (DOC) and by CNR and MIUR, Italy.A preliminary version of this paper appeared as [21].     

由8032单片机构成的通信协转换器的设计与实现

目前正在配电系统中使用的用于电能监测和电能计量的许多多功能表没有使用统一的通信协议,这给自动抄表技术的实施来不便,为了使得多功能表能以统一的通信协议与抄表系统的抄表中心控制机通信,提出了使用通信协议转换器的抄表系统结构,介绍了基于8032单片机实现的抄表系统通信协议转换器。     

煤粉用电除尘器的试验研究

本文对煤粉进行了大量的收尘试验和引爆试验，得出了煤粉的驱进速度对影响收尘效率的主要因素和安全防爆问题进行了研究讨论，为煤粉用电除尘器的设计提供了可靠的试验数据和依据。这些工作对用于其它粉尘的电除尘器设计也具有重要意义。     

浅谈宽带EMI接收机扫描控制器设计

本文介绍了宽带EMI接收机扫描控制器的功能,并给出了基于CPLD的详细设计方案。     

用偏压限制器控制KT－5C托卡马克等离子体边缘电场的实验研究

在托卡马克ＫＴ－５Ｃ上，我们首次采用可灵活组合的多块限制器进行了施加偏压以控制等离子体边缘电场的实验，结果表明，在本装置上限制器加正偏压优于加负偏压，正偏压改变等离子体边缘电场效果更明显。偏压限制器收集面积、纵场和偏置电压的大小对偏压效果的影响都是敏感的。改变限制器收集面积和偏压导致的边缘电场的变化最终将趋于饱和，另外发现，偏压限制器与等离子体柱的相对位置对等离子体边缘电场的影响也是重要的。     

采集舌象用光源的光谱研究

在中医舌诊中,传统的光源通常为自然光甚至烛光,易受气候,环境干扰,不利于医生获得正确的舌苔色泽信息。文章引进人造光源作为对自然光源的补充或直接应用人造光源来代替自然光,能得到稳定和真实的舌态图像,获得科学严谨的诊断结果。不同的光源由于其各异的辐射光谱功率分布,显色性Ra和色温Tc的不同对同一物体照明会产生不同的颜色。文章选择了四种人造光源,通过光谱分析和分别照明时拍摄的相同图像[1]、舌象,用舌象视觉计算比较的方法选出了最佳光谱对应的光源,并在多个光学参数,色坐标容差椭圆等色度学参数上进行比较,得出一种最接近于自然光的光源,即PHILIPS YPZ220/18-3U.RR.D型光源,其色温为6 500 K的光谱特性及光学参数最接近自然光源,可作为采集舌象时的照明标准光源。此方法可为选择人造标准光源替代自然日光提供理论和实验依据。