An economic evaluation model of supply chain flexibility

With the advent of the supply chain management concepts, business communities have been realizing that being competitive as a single company is no longer adequate; instead, competitiveness requires consideration of all channels in the supply chain. Despite its importance, the availability of the literature addressing supply chain flexibility is still limited to date. Although relationships between various types of flexibilities have been established, the degree to which one type of flexibility affects the other types and the system performance remains to be investigated. In particular, there is a lack of rigorous analytical models elucidating the relationships between the degree of flexibility in a system and the system level of performance. In this paper, a supply chain flexibility model is developed comprising labor flexibility, machine flexibility, routing flexibility, and information technology, with total system flexibility measured by an economic index. Outputs from the model can assist in making suitable production decisions to produce multiple products under an uncertain environment. Example solutions are given. This paper can help economic evaluation when supply chain flexibility and the factors affecting flexibility are to be improved. It can also assist in making supply chain flexibility-promotion decisions.     

A generalized geometric-programming solution to “An economic production quantity model with flexibility and reliability considerations”

The classical economic production quantity (EPQ) model assumes that items are produced by a perfectly reliable production process with a fixed set-up cost. While the reliability of the production process cannot be perfected cost-free, the set-up cost can be reduced by investment in flexibility improvement. In this paper, we propose an EPQ model with a flexible and imperfect production process. We formulate this inventory decision problem using geometric programming (GP), establish more general results using the arithmetic-geometric mean inequality, and solve the problem to obtain a closed-form optimal solution. Following the theoretical treatment, we provide a numerical example to demonstrate that GP has potential as a valuable analytical tool for studying a certain class of inventory control problems. Finally we discuss some aspects of sensitivity analysis of the optimal solution based on the GP approach.     

聚合物结构对包膜缓释肥缓释性能的影响

研发和使用缓控释肥能有效解决普通肥料利用率低以及由于化肥使用过量而引起的环境问题。聚合物包膜型缓控释肥是缓控释肥中的一种,影响其缓释性能的因素如环境因素、包膜厚度、加工工艺等,前人已研究较多。聚合物结构对于缓释性能的影响也很重要,而这方面研究较少。本文主要讨论了聚合物结晶性、分子亲疏水性、分子链柔顺性、交联等结构因素对缓释性能的影响。深入研究聚合物结构对缓释性能的影响有助于缓控释材料的创新;能为聚合物包膜材料的设计、聚合物缓控释肥的研发及生产提供一定的理论依据。     

Impact of the flexibility of pillar linkers on the structure and CO_2 adsorption property of ‘‘pillar-layered' MOFs

A new metal–organic framework {[Zn_2(bpta)(bpy-ee)(H_2O)_2]·x solve}_n(1)(H_4bpta = biphenyl-2,20,6,60-tetracarboxylic acid and bpy-ee = 1,2-bis(4-pyridyl)ethylene) has been obtained under hydrothermal condition, and structurally characterized by single-crystal X-ray diffraction. Complex 1 reveals a threedimensional(3D) ‘‘pillar-layered' framework with non-flexible linker, in which some different structure characters can be found compared to that of some related other ‘‘pillar-layered' MOFs based on flexible pillar linkers. It demonstrates the impact of the flexibility of pillar linker on the final structure in this system. In addition, the selective CO_2 adsorption performance of 1 was also investigated.     

反倾层状边坡弯曲折断的应力及挠度判据

以地质分析为基础 ,将反倾层状边坡的任意岩层概化为受复合作用力的板梁模型 ,通过简单的力学解析 ,开展了反倾层状岩石边坡弯曲折断判据的研究。依据岩层折断时和相临岩层的瞬时关系 ,将岩层下部视为瞬时临空状态 ,考虑岩层自重荷载和上部岩层附加荷载 (上部岩层重力荷载、层间摩擦力 )的共同作用 ,基于最大拉应力准则 ,提出了岩层弯曲折断的应力判据 ;依据应力判据 ,得到了岩层弯曲折断的挠度判据 ;利用应力判据及挠度判据 ,可实现反倾层状边坡弯曲折断的现场判定及其控制设计     

柔韧性羧端基不饱和聚酯粉末涂料的研制

本文研制了粉末涂料用柔韧性羧端基不饱和聚酯树脂及其相应的环氧树脂固化的柔韧性不饱和聚酯粉末涂料，讨论了树脂合成，涂料制备及涂层性能，涂层的装饰性能特别是柔韧性能有了较大改善。     

“嵌埋式实时操作系统”灵活性的研究

本文阐述了“嵌埋式实时操作系统”灵活性的三个因素；可移植性、可配置性、可剪裁性及其概念和重要性，并提出了一些设计和实现的方法。     

Mapping ICT use at home and telecommuting practices: A perspective from work/family border theory

This study draws on the work/family border theory to investigate the role of information communication technology (ICT) use at home in shaping the characteristics of work/family borders (i.e. flexibility and permeability) and consequently influencing individuals’ perceived work-family conflict, technostress, and level of telecommuting. Data were collected from a probability sample of 509 information workers in Hong Kong who were not self-employed. The results showed that the more that people used ICT to do their work at home, the greater they perceived their work/family borders flexible and permeable. Interestingly, low flexibility and high permeability, rather than the use of ICT at home, had much stronger influences on increasing, in particular, family-to-work conflict. As expected, work-to-family conflict was significantly and positively associated with technostress. Results also showed that the telecommuters tended to be older, had lower family incomes, used ICT frequently at home, and had a permeable boundary that allowed work to penetrate their home domain. The theoretical and practical implications are discussed.     

Top-gate organic field-effect transistors fabricated on paper with high operational stability

We report on top-gate organic field-effect transistors (OFETs) fabricated on specialty paper, PowerCoat™ HD 230 from Arjowiggins Creative Papers coated with a buffer layer composed of a polyvinyl alcohol (PVA) and polyvinylpyrrolidine (PVP) blend. OFETs operate at low voltages and display average carrier mobility values of 1.7 ± 1.1 × 10⁻¹ cm²/Vs, average threshold voltage values of −1.4 ± 0.2 V, and average on/off current ratio of 10⁵. OFETs also display excellent operational stability demonstrated by stable 1000 scans of the transfer characteristics and by stable on-currents displaying less than 6% change during a DC bias stress test at V_DS = V_GS = −10 V for 1 h. Furthermore, OFETs on paper display a decrease of only 7% in their on-state current during a bending test. The performance of these OFETs on paper is comparable to that displayed by top-gate OFETs with the same geometry fabricated on glass substrates.     

Supercooled Liquids with Dynamic Room Temperature Phosphorescence Using Terminal Hydroxyl Engineering

Dynamic room temperature phosphorescence (RTP) materials have potential applications in optoelectronics, which inevitably suffer from poor processability, flexibility or stretchability. Herein, we report a concise strategy to develop supercooled liquids (SCLs) with dynamic RTP behavior using terminal hydroxyl engineering. The terminal hydroxyls effectively hinder the nucleation process of molecules for the formation of stable SCLs after thermal annealing. Impressively, the SCLs show reversible RTP emission via alternant stimulation by UV light and heat. Photoactivated SCLs have phosphorescent efficiency of 8.50 % and a lifetime of 31.54 ms under ambient conditions. Regarding the dynamic RTP behavior and stretchability of SCLs, we demonstrate the applications in erasable data encryption and patterns on flexible substrates. This finding provides a design principle for obtaining SCLs with RTP and expands the potential applications of RTP materials in flexible optoelectronics.