革新质量观念,打造制造业强国

最近美国内布拉斯加州林肯大学的MARC J.SCHNIEDERJANS等人对中国制造产品和外国制造产品进行了对比调查与分析,根据对500位美国消费者的调查数据分析,中国产品平均质量得分2.77(满分为10分),非中国产品平均质量得分7.22.这一结果显示中国产品在美国消费者心目中的质量形象很差,这对于希望成为世界制造业基地的中国来说应是一个值得警惕的信号.尽管2004年中国国际贸易额将突破万亿美元大关,但我们必须冷静思考:中国产品仅仅依靠低廉价格抢占国际市场的做法是否可以长期持续?外国对我国产品的反倾销制裁日益频繁、当地制造业的激烈抵制给我国企业敲响了警钟:市场竞争不仅仅是价格竞争,更重要的是质量竞争.那么,是什么制约了中国产品质量的提高?     

Transient aspects of inner wall temperatures at different spatial positions in fluidized bed evaporators

In this work, the instantaneous data of inner wall temperatures obtained at given axial positions but for different heated tubes or at various axial positions but at the same heated tube in a tube-bank fluidized bed evaporator with a vapor–liquid–solid external natural circulation flow were analyzed by employing linear and nonlinear time series analysis methods, including correlation dimension and Kolmogorov entropy analyses besides time domain, power spectrum and autocorrelation analyses. It is found that nonlinear characteristics of the wall temperature time series vary with spatial position in the evaporator at given operation conditions, and thus the multi-phase flow boiling behavior. However, the signals obtained at given axial position but different heated tubes in the evaporator exhibit more similar nonlinear evolution behavior, and those measured in the same heated tube but at different axial heights in the evaporator undergo more distinct nonlinear dynamic behavior. Multi-scale phenomena in different spatial positions are also found and discussed. These transient aspects of inner wall temperatures are closely related to the average holdup of solid particles and motion of vapor bubbles in vapor–liquid–solid flow. These results can provide some valuable information on the system modeling and controlling from the point of view of nonlinearity.     

Study of trace elements in coal and mining wastes and its significance in China

In the world energy about 26% of all was dedved from coal combustion. Nearly 80% of the electricity produced in China is generated from coal. Coal will play the most important role in the coming 50 years as the past century in China. However one consequentially of the mining and combustion of coal is the mobilization of trace elements, especially trace metals, which have environmental and human health significance. Information on concentrations and distributions of potentially toxic elements in coal, and information On the modes of occurrence of these elements and the relations of the minerals in coal can help to predict the behavior of the potentially toxic trace metals dudng cleaning, combustion, weathering, and leaching.     

The effect of ionic interaction on the miscibility and crystallization behaviors of poly(ethylene glycol)/poly(L‐lactic acid) blends

The effect of end groups (2NH₂) of poly(ethylene glycol) (PEG) on the miscibility and crystallization behaviors of binary crystalline blends of PEG/poly(L ‐lactic acid) (PLLA) were investigated. The results of conductivity meter and dielectric analyzer (DEA) implied the existence of ions, which could be explained by the amine groups of PEG gaining the protons from the carboxylic acid groups of PLLA. The miscibility of PEG(2NH₂)/PLLA blends was the best because of the ionic interaction as compared with PEG(2OH, 1OH‐1CH₃, and 2CH₃)/PLLA blends. Since the ionic interaction formed only at the chain ends of PEG(2NH₂) and PLLA, unlike hydrogen bonds forming at various sites along the chains in the other PEG/PLLA blend systems, the folding of PLLA blended with PEG(2NH₂) was affected in a different manner. Thus the fold surface free energy played an important role on the crystallization rate of PLLA for the PEG(2NH₂)/PLLA blend system. PLLA had the least fold surface free energy and the fast crystallization rate in the PEG(2NH₂)/PLLA blend system, among all the PEG/PLLA systems studied. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Establishing a System for Food Recalls to Protect Food Quality and Safety in China

There are no explicit laws concerning food recalls in China; moreover, some related regulations have weaknesses. China should first create a system of laws and regulations governing food recalls, establish a system to recall defective food, and strengthen administrative and legal remedial mechanisms related to consumer rights.     

一种网络服务自动部署方法

为满足网络服务使用者对网络服务部署的功能性和非功能性需求,运用Petri网的方法进行了互联网动态多变环境下的网络服务自动部署的研究,建立了一种基于Petri网的网络服务部署网模型,从形式化的角度描述了网络服务功能的部署情况,提出了一种按照服务质量来选择最优网络服务部署的算法。仿真的结果表明,与目前常用的固定部署算法和随机部署算法相比,按照该方法得到的网络服务部署能最好地满足服务使用者对服务的非功能性方面的需求。     

ERP的实施与风险防范

在管理应用的广度方面，ERP超越了MRP的应用范围。文中指出了实施ERP系统的步骤及ERP实施中应注意的问题，强调企业有必要对风险有充分认识，建立一套行之有效的风险管理机制，从而提高了ERP系统的实施成功率，最终提高企业的管理水平。     

Passivity Analysis of Dynamic Neural Networks with Different Time-scales

Dynamic neural networks with different time-scales include the aspects of fast and slow phenomenons. Some applications require that the equilibrium points of the designed networks are stable. In this paper, the passivity-based approach is used to derive stability conditions for dynamic neural networks with different time-scales. Several stability properties, such as passivity, asymptotic stability, input-to-state stability and bounded input bounded output stability, are guaranteed in certain senses. A numerical example is also given to demonstrate the effectiveness of the theoretical results.     

钢包炉(LF)预熔精炼渣的研究

预熔精炼渣具有成分均匀，性能稳定，储存时不吸水等特点，钢包炉中使用预熔精炼渣时成渣均匀且速度快，具有较强的吸附钢中非金属夹杂的能力。综合脱硫率高等冶金效果。有显著净化钢液作用。