中国特色的低碳经济、能源、电力之路初探

中国作为发展中大国,探索一条适合我国国情的低碳经济-能源-电力的发展路径是至关重要的。在过去30年中,我国在节能方面取得了巨大成就,可以概括为具有中国特色的能源使用管理,它是低碳能源的重要组成部分。综合资源战略规划与智能电网构成低碳电力。它们将在中国的低碳经济中发挥重要作用。本文结合中国国情,在低碳经济(低碳能源与低碳电力)的模型基础上,展望了未来20年我国经济发展前景、能源的需求、能源消费结构、非化石能源的比重、能耗-电耗水平、CO2排放强度,以及经济发展对电力的需求、电源的结构、清洁能源的发电比重,能效电厂及其发电量(终端电力用户节约的电量)等,分析了今后发展应关注的问题。     

关于“理想城市”的几点感知

在未来的20年,世界城市将以史无前例的速度和规模迅猛扩张。其中正在崛起的亚洲地区,特别是中印两国被认为是最典型的案例。交通拥堵,环境污染,房价飞腾,健康危害,安全弱化,文化丧失等问题造就了多种多样的城市病,离开了人,城市就不付存在。城市的所有问题都是由人而引发,中国城市最缺的不是知识、历史、也不是硬件的基础建设,而是城...     

珠海情侣北路南段填海区特色塑造的规划对策研究

珠海市情侣北路南段填海区现状建设简单、规划整合阻力较小,对外交通联系便捷,自然景观优势明显,可通过强化研究明确填海区城市定位与职能、多方案比较确定填海区整体骨架结构、强化理念指导填海区的用地功能布局、有效衔接打造多层面复合型交通网络、多角度分析构建合理的城市开敞空间、臻善城市轮廓线,强化其滨海特色形象,采用导则与图则相...     

Placement sequence identification using artificial neural networks in surface mount PCB assembly

The widespread use of automation in the printed circuit board (PCB) assembly domain has been dictated by the increasing density of components on PCBs coupled with the continual decrease in component lead pitch, greater product mix, smaller volumes, quality considerations, and the increased cost of labour. However, these advances in technology have also resulted in automated systems that are complex, and solving problems related to these systems requires the efficient use of extensive specialised knowledge.Expert (or knowledge-based) systems have become a widely accepted problem solving methodology for the surface mount PCB assembly domain. Nevertheless, problems in the PCB assembly domains are frequently unstructured, ill-defined, and difficult to communicate. Artificial neural networks provide a novel approach and an advanced technology to deal with the weaknesses and problems associated with expert systems.The surface mount component (SMC) placement process plays a vital and influential part in determining the throughput time of a PCB assembly line. It is important to identify an efficient component placement sequence while considering constraints such as feeder location and tooling and nozzle optimisation. This research studied the use of artificial neural networks as a complement to expert systems in PCB assembly. A prototype decision support system that combined the use of artificial neural networks and expert system techniques to identify a near optimal solution for the surface mount placement sequence problem was designed, implemented, and validated. Artificial intelligence based technologies such as expert systems and artificial neural networks were used in a mutually supportive manner to solve a complex problem within the surface mount PCB assembly domain.     

浙江纺织服装企业自主创新模式探析——基于产业链升级的视角

从浙江纺织服装企业发展的现状出发,结合价值链管理的“微笑曲线”理论,提出浙江纺织服装企业进行自主创新的三大路径,并通过分析价值链升级的三大路径,总结出了六大自主创新模式.     

浅论浙江省农村能源生态建设现状及规划

本文概述了浙江省农村能源生态建设现状;并根据不同地区的经济发展和自然条件,提出了能源生态建设规划和对策措施。     

An interval fixed-mix stochastic programming method for greenhouse gas mitigation in energy systems under uncertainty

In this study, an interval fixed-mix stochastic programming (IFSP) model is developed for greenhouse gas (GHG) emissions reduction management under uncertainties. In the IFSP model, methods of interval-parameter programming (IPP) and fixed-mix stochastic programming (FSP) are introduced into an integer programming framework, such that the developed model can tackle uncertainties described in terms of interval values and probability distributions over a multi-stage context. Moreover, it can reflect dynamic decisions for facility-capacity expansion during the planning horizon. The developed model is applied to a case of planning GHG-emission mitigation, demonstrating that IFSP is applicable to reflecting complexities of multi-uncertainty, dynamic and interactive energy management systems, and capable of addressing the problem of GHG-emission reduction. A number of scenarios corresponding to different GHG-emission mitigation levels are examined; the results suggest that reasonable solutions have been generated. They can be used for generating plans for energy resource/electricity allocation and capacity expansion and help decision makers identify desired GHG mitigation policies under various economic costs and environmental requirements.     

Numerical study of assembly pressure effect on the performance of proton exchange membrane fuel cell

The performance of the fuel cell is affected by many parameters. One of these parameters is assembly pressure that changes the mechanical properties and dimensions of the fuel cell components. Its first duty, however, is to prevent gas or liquid leakage from the cell and it is important for the contact behaviors of fuel cell components. Some leakage and contact problems can occur on the low assembly pressures whereas at high pressures, components of the fuel cell, such as bipolar plates (BPP), gas diffusion layers (GDL), catalyst layers, and membranes, can be damaged. A finite element analysis (FEA) model is developed to predict the deformation effect of assembly pressure on the single channel PEM fuel cell in this study. Deformed fuel cell single channel model is imported to three-dimensional, computational fluid dynamics (CFD) model which is developed for simulating proton exchange membrane (PEM) fuel cells. Using this model, the effect of assembly pressure on fuel cell performance can be calculated. It is found that, when the assembly pressure increases, contact resistance, porosity and thickness of the gas diffusion layer (GDL) decreases. Too much assembly pressure causes GDL to destroy; therefore, the optimal assembly pressure is significant to obtain the highest performance from fuel cell. By using the results of this study, optimum fuel cell design and operating condition parameters can be predicted accordingly.     

利用水基清洗，提高柱塞偶件的清洁度

本文介绍了在生产过程中采用水基清洗工艺代替传统的油基清洗工艺，不仅能提高和保证产品的清洁度，而且还能节约燃料，改善工作环境和消除安全隐患。     

管束式集装箱的组装工艺和型式试验要求

大容积无缝钢瓶、管柬式集装箱和长管拖车作为专用气体储运装备在我国使用和制造已有10年时间,在检验检测和安全监管方面已基本形成相应的安全规范,但设计制造缺乏标准支撑。本文对管柬式集装箱的设计制造资质、组装工艺和型式试验要求进行简要介绍,包括大容积无缝钢瓶和长管拖车的相应要求。