地下通风系统管理的新技术——系统特征图

本文介绍系统特征图的原理与方法 ,及其推广应用的前景     

Unicast-based multicast communication in wormhole-routed networks

Multicast communication, in which the same message is delivered from a source node to an arbitrary number of destination nodes, is being increasingly demanded in parallel computing. System supported multicast services can potentially offer improved performance, increased functionality, and simplified programming, and may in turn be used to support various higher-level operations for data movement and global process control. This paper presents efficient algorithms to implement multicast communication in wormhole-routed direct networks, in the absence of hardware multicast support, by exploiting the properties of the switching technology. Minimum-time multicast algorithms are presented for n-dimensional meshes and hypercubes that use deterministic, dimension-ordered routing of unicast messages. Both algorithms can deliver a multicast message to m-1 destinations in [log ₂ m] message passing steps, while avoiding contention among the constituent unicast messages. Performance results of implementations on a 64-node nCUBE-2 hypercube and a 168-node Symult 2010 2-D mesh are given     

Well-posedness of dual-phase-lagging heat conduction equation: higher dimensions

The dual-phase-lagging heat conduction equation is shown to be of one unique solution for a finite region of dimension n (n?2) under Dirichlet, Neumann or Robin boundary conditions. The solution is also found to be stable with respect to initial conditions. The work is of fundamental importance in applying the dual-phase-lagging model for the microscale heat conduction of high-rate heat flux.     

南化大化肥硝铵库屋面施工防渗漏措施

南化大化肥硝铵库工程 ,于 2 0 0 0年 2月 15日开工 ,2 0 0 0年 10月 10日竣工 ,混凝土杯形基础 ,主体结构为单层、单跨、装配式的排架结构 ,30ｍ预应力折线形屋架 ,大型屋面板 ,氯化聚乙烯防水卷材 ,建筑面积为 162 0ｍ2 。氯化聚乙烯防水卷材是防水新型材料 ,由于防水性能好 ,施工方便 ,近几年得到了广泛的应用 ,在实际操作中往往由于施工人员对操作规程不甚了解 ,或虽有所了解 ,但没有认真对待 ,造成这样那样的质量问题 ,硝铵库作为一个储物库房 ,对防渗漏的要求高 ,那么施工中怎样避免出现渗漏现象 ,确保工程质量呢 ?1　做好施工准备检…     

面向WCDMA建立网络管理信息模型

分析了WCDMA移动通信网网管系统管理框架，在此基础上提出采用公共对象请求代理体系结构（CORBA）建立网管系统信息模型的优势，给出WCDMA网管系统的信息模型，同时介绍了对象管理组（OMG）接口描述语言（IDL）。     

Improving signal prediction performance of neural networks through multiresolution learning approach.

In this paper, we extend the original work on multiresolution learning for neural networks, and present new developments on the multiresolution learning paradigm. The contributions of this paper include: (1) proposing a new concept and method of adjustable neural activation functions in multiresolution learning to improve neural network learning efficacy and generalization performance for signal predictions; (2) providing new insightful explanations for the multiresolution learning paradigm from a multiresolution optimization perspective; (3) exploring underlying ideas why the multiresolution learning scheme associated with adjustable activation functions would be more appropriate for the multiresolution learning paradigm; and (4) providing rigorous validations to evaluate the multiresolution learning paradigm with adjustable activation functions and comparing it with the schemes of multiresolution learning with fixed activation functions and traditional learning. This paper presents systematically new analytical and experimental results on the multiresolution learning approach for training an individual neural network model, demonstrates our integral solution on neural network learning efficacy, and illustrates the significant improvements on neural networks' generalization performance and robustness for nonlinear signal predictions.     

利用新型场效应管(QFET)的正向变换器

介绍了单端正向变换器基本电路，重点叙述带三路调节DC电压的100KHZ180W离线电源。它采用具有低导电阻RDS和低栅极电荷Qg的新型场效应管（QFET）作为变换电路的主开关器件，降低了电源开关损耗并提高了效率3%-5%。     

由乙腈一步法制备乙酸丁酯的研究

以丁醇和制备丙烯腈的副产物乙腈为原料 ,采用一步法合成了乙酸丁酯。通过正交实验得到了影响反应的 4种因素。确定了最佳的工艺条件为 :催化剂的量为样品质量的 40 % ;n(CH3CN)∶ n(C4 H9OH) =1∶ 1 .0 5 ;反应温度为 1 0 5℃ ;反应时间为 8h。在此反应条件下 ,乙酸丁酯的收率为 88.8% ,纯度可达 99.5 %。并用气相色谱及红外光谱对产品的纯度进行了表征     

橡胶卷材挤出连续硫化生产线的结构特色与工作原理

介绍了橡胶防水防腐卷材挤出连续硫化生产线的结构、特点和工作原理;指出在目前国内同类设备中,该生产设备具有先进性,并可替代引进设备。