基于规模经济理论的物流配送中心选址方法研究

物流配送中心的建设与经营对周边地区乃至整个城市的经济发展以及所处区域的生态环境都具有非常重要的影响,物流配送中心选址需要考虑的因素很多,选址方法既要具有科学性又要具有可行性。物流配送中心选址方法很多,大体可分为定性分析方法与定量分析方法。文章基于规模经济理论的思想,利用德尔菲法和层次分析法,提出了符合规模经济要求的物流配送中心选址模型,该模型既能确保物流中心满足本区域的物流需求量,又可通过对有物流服务需求的区域进行分块,减少物流服务中物流成本的重复计算,降低数据调查的难度与模型求解的难度。

地方矿山生态可持续发展模式研究──以迁安包官营铁矿为例

以迁安包官营铁矿为例分析了地方矿山实施生态可持续发展的可能 ,并利用能源、物流分析方法对该矿生态复垦模式进行了分析 ,分析结果表明该生态复垦模式基本合理 ,是地方矿山实现可持续发展的可行之路。

Analysis of anthropogenic aluminum cycle in China

Anthropogenic aluminum cycle in China was analyzed by the aluminum flow diagram based on the life cycle of aluminum products. The whole anthropogenic aluminum cycle consists of four stages： alumina and aluminum production, fabrication and manufacture, use and reclamation. Based on the investigation on the 2003-2007 aluminum cycles in China, a number of changes can be found. For instance, resources self-support ratio （RSR） in alumina production dropped from 95.42%to 55.50%, while RSR in the aluminum production increased from 52.45%to 79.25%. However, RSR in the Chinese aluminum industry leveled off at 50%in the period of 2003-2007. The respective use ratios of domestic and imported aluminum scrap in the aluminum industry of 2007 were 5.38% and 9.40%. In contrast, both the net imported Al-containing resources and the lost quantity of Al-containing materials in aluminum cycle increased during the same period, as well as the net increased quantity of Al-containing materials in social stock and recycled Al-scrap. Proposals for promoting aluminum cycle were put forward. The import/export policy and reducing the loss of Al-containing materials for the aluminum industry in China in the future were discussed.

Comparative Study on the Development Levels of Cold Chain Logistics for Agricultural Products between China and Developed Countries Based on Analytic Hierarchy Process

By introducing the analytic hierarchy process （AHP）, a model is constructed to compare the logistics development level of cold chain for agricultural products between China and other developed countries such as United States, Japan and Euro- pean. The paper makes a comparative study on the development levels of agricultural cold chain logistics in China and developed countries from the aspects of the level of cold chain logistics facilities and equipments, the degree of cold chain logistics market-oriented and the capacity of cold chain logistics, then determines the problems of cold chain logistics in China. With the experiences learning from developed countries, some countermeasures are proposed to resolve those problems of cold chain logistics for agricultural products development combining with the national conditions in China.

Multi-physics analysis of permanent magnet tubular linear motors under severe volumetric and thermal constraints

Permanent magnet tubular linear motors(TLMs) arranged in multiple rows and multiple columns used for a radiotherapy machine were studied. Due to severe volumetric and thermal constraints, the TLMs were at high risk of overheating. To predict the performance of the TLMs accurately, a multi-physics analysis approach was proposed. Specifically, it considered the coupling effects amongst the electromagnetic and the thermal models of the TLMs, as well as the fluid model of the surrounding air. To reduce computation cost, both the electromagnetic and the thermal models were based on lumped-parameter methods. Only a minimum set of numerical computation(computational fluid dynamics, CFD) was performed to model the complex fluid behavior. With the proposed approach, both steady state and transient state temperature distributions, thermal rating and permissible load can be predicted. The validity of this approach is verified through the experiment.

Fluid-Solid Interaction Analysis of Drug Delivery Mechanism to Damaged Cancer Cellules in the Shape of Single-Walled Carbon Nanocone by Molecular Mechanics Approach

Drug delivery systems able to deliver the required dose of the drug to the target level use active or passive nano metric designed systems. In the earlier researches, carbon nanocones are used for transferring the serum to damaged proteins and damaged cancer cellules. In this lecture, stability analysis of drug delivery to damaged cancer cellutes is studied in the shape of single-walled carbon nanocone. In this method, each atom is considered as node and interactions between them are supposed as 3D-beam elements. By supposing that potential energy in macro relations is equal to the nano relations, nano-drug characteristics can be calculated. Then shape functions can be extracted to use in blood＇s FEM model and using reduced-order method, divergence velocities of carbon nanocone can be found. In this lecture, carbon nanocones are modeled with different dimensions and boundary conditions and stability of them in blood flow is studied and optimized carbon nanocone is selected in blood flow. Results show that conical nano-drug structures have more efficiency in blood flow rather than tube nano-drug structures and by increasing length of carbon nanocones, dimensionless stability parameter decreased and by increasing declination angle of carbon nanocones, dimensionless stability parameter increased.