用PLC实现加氯串级比值控制

以水厂后加氯自动控制系统为例 ,介绍了由PLC、流量计和余氯检测仪等构成的串级和比值系统的控制原理及系统运行步骤 ,表明了系统具有良好的控制品质     

光纤应变传感系统消噪技术的研究

本文分析干涉式光纤应变传感系统中噪声对系统分辩率的影响,提出消除光源幅度、相位噪声和环境噪声的措施。     

A Network Architecture with High Availability for Real-time Premium Traffic over the Internet

Real-time traffic will be a predominant traffic type in the next generation networks, and networks with 100% reliability and availability will be required by real-time premium traffic. It is believed that QoS guarantees could be better provided by connection oriented networks such as Multi Protocol Label Switching (MPLS). These connection oriented networks are more vulnerable to network failure. Conventional path protection methods perform re-routing to cope with this. However, re-routing always causes packet losses and results in service outage. These losses are bursty in nature and highly degrade the QoS of the real-time premium traffic. Thus, 100% availability cannot be achieved by conventional methods. The novel path protection proposed in this paper recovers the bursty packet losses due to re-routing by using forward error correction (FEC) path. Therefore, it can provide network architecture with no service outage for such traffic. The numerical results show that the proposed method can achieve a very high availability for real-time premium traffic in future IP/MPLS networks.

Streaming potential and electroviscous effect in heterogeneous microchannels

This communication presents a theoretical analysis of the streaming potential and the electroviscous effect on pressure-driven flow in heterogeneous microchannels. Compact formulae in terms of phenomenological coefficients are derived for the streaming potential and the apparent viscosity ratio in channels with surface charge variations perpendicular and parallel to the applied pressure gradient. In the latter case, the streaming potential per unit liquid flow in a multi-section channel is found to be simply the summation of that in each homogeneous section. The apparent viscosity ratio is a weighted average of each section where the hydrodynamic resistance serves as the weighting factor. The phenomenological coefficients are specified using electrokinetic flow analysis, through which the streaming potential and electroviscous effect in a two-section slit channel are examined. It is found that they both depend on the arrangement of surface heterogeneity in small microchannels. This dependence, however, gets weak in large microchannels, which is consistent with the prediction of thin double layer approximation.

材料在城市公共设施设计中的应用

公共设施作为城市空间的要素之一,已是城市形象构筑中不可缺少的一部分。在提倡可持续发展的现代社会,产品在满足审美性、使用性的同时,材料的应用至关重要。本文分析现代社会,城市公共设施设计中材料的使用情况,并从绿色设计角度展望未来的材料前景。     

A Face Identification System Based on the Mahalanobis–Taguchi System

In this paper, we propose a face identification system based on the Mahalanobis–Taguchi System (MTS). The MTS is one of the pattern recognition methods frequently used in quality engineering, and can perform robust pattern recognition by using training data, including noise. It is likely that this advantage will allow the effective implementation of a robust face identification system against lighting and face position fluctuations. Moreover, the MTS can optimize the number of attributes required for identification by using the orthogonal array and the signal/noise (SN) ratio. The face identification system has to deal with many users and the amount of data in a facial image is large. Therefore, the time required for identification can be decreased and the amount of data in the facial image database can be reduced by performing the optimization. We confirmed the effectiveness of the proposed system through practical experiments. The experimental results revealed that the MTS was an effective method for robust face identification, and could effectively reduce the number of attributes required for identification.     

耐高温多晶硅应变计

介绍了一种适用于特殊环境进行高温测量的多晶硅应变计的原理、设计、制作工艺及粘贴方法。它的特点是耐高温 (可用在温度达 2 5 0℃的环境中 )、体积小、安装方便。该种应变计已用于检测电站锅炉焊缝的牢固程度 ,在实际应用中性能较好     

Data distribution schemes of sparse arrays on distributed memory multicomputers

A data distribution scheme of sparse arrays on a distributed memory multicomputer, in general, is composed of three phases, data partition, data distribution, and data compression. To implement the data distribution scheme, many methods proposed in the literature first perform the data partition phase, then the data distribution phase, followed by the data compression phase. We called a data distribution scheme with this order as Send Followed Compress (SFC) scheme. In this paper, we propose two other data distribution schemes, Compress Followed Send (CFS) and Encoding-Decoding (ED), for sparse array distribution. In the CFS scheme, the data compression phase is performed before the data distribution phase. In the ED scheme, the data compression phase can be divided into two steps, encoding and decoding. The encoding step and the decoding step are performed before and after the data distribution phase, respectively. To evaluate the CFS and the ED schemes, we compare them with the SFC scheme. In the data partition phase, the row partition, the column partition, and the 2D mesh partition with/without load-balancing methods are used for these three schemes. In the compression phase, the CRS/CCS methods are used to compress sparse local arrays for the SFC and the CFS schemes while the encoding/decoding step is used for the ED scheme. Both theoretical analysis and experimental tests were conducted. In the theoretical analysis, we analyze the SFC, the CFS, and the ED schemes in terms of the data distribution time and the data compression time. In experimental tests, we implemented these three schemes on an IBM SP2 parallel machine. From the experimental results, for most of test cases, the CFS and the ED schemes outperform the SFC scheme. For the CFS and the ED schemes, the ED scheme outperforms the CFS scheme for all test cases.

多降液管结晶罐的循环比的确定

结晶罐的循环比是否合理,反映了结晶罐结构性能的优劣。本文通过对糖膏在结晶罐中流动的压力降的分析,讨论了多降液管结晶罐的循环比的理论计算,并提出了等比例的校正方法,使整个计算过程变得非常简单。     

High-pressure plastic flow in silicon: A first-principles theoretical study

Summary Microindentation experiments have recently shown that silicon can exhibit plastic flow when subjected to high pressure. Assuming that under these conditions the relevant reference structure is the -Sn high-pressure phase of silicon, we apply the magic-strain concept to explore the space of configurations that could describe the observed behavior. We use first-principles total-energy calculations (including full relaxation of the atomic basis for every structure) to evaluate the relevance of strained configurations. Using this approach, we were able to identify a low-energy path that corresponds to planar flow of the atoms. The atomic configurations along this path provide insight into possible microscopic motions under high pressure that may be relevant to plastic flow in silicon.