Dynamic Scheduling on a Single Batch Processing Machine with Split Compatibility Graphs

We consider the problem of minimizing the makespan on a batch processing machine, in which jobs are not all compatible. Only compatible jobs can be included into the same batch. This relation of compatibility is represented by a split graph. Jobs have release dates. The capacity of the batch processing machine is finite or infinite. The processing time of a batch is given by the processing time of the longest job in the batch. We establish the NP-hardness of the general problem and present polynomial algorithms for several special cases. Relating scheduling theory and graph theory appears to be an interesting and important concept.     

Synthesis and morphology of polyethylene‐block‐poly(methyl methacrylate) through the combination of metallocene catalysis with living radical polymerization

Polyethylene‐block‐poly(methyl methacrylate) (PE‐b‐PMMA) was successfully synthesized through the combination of metallocene catalysis with living radical polymerization. Terminally hydroxylated polyethylene, prepared by ethylene/allyl alcohol copolymerization with a specific zirconium metallocene/methylaluminoxane/triethylaluminum catalyst system, was treated with 2‐bromoisobutyryl bromide to produce terminally esterified polyethylene (PE‐Br). With the resulting PE‐Br as an initiator for transition‐metal‐mediated living radical polymerization, methyl methacrylate polymerization was subsequently performed with CuBr or RuCl₂(PPh₃)₃ as a catalyst. Then, PE‐b‐PMMA block copolymers of different poly(methyl methacrylate) (PMMA) contents were prepared. Transmission electron microscopy of the obtained block copolymers revealed unique morphological features that depended on the content of the PMMA segment. The block copolymer possessing 75 wt % PMMA contained 50–100‐nm spherical polyethylene lamellae uniformly dispersed in the PMMA matrix. Moreover, the PE‐b‐PMMA block copolymers effectively compatibilized homopolyethylene and homo‐PMMA at a nanometer level. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3965–3973, 2003     

Remarks on Two Approaches to the Horizontal Cohomology: Compatibility Complex and the Koszul–Tate Resolution

The Koszul–Tate resolution is described in the context of the geometry of jet spaces and differential equations. The application due to Barnich, Brandt, and Henneaux of this resolution to computing the horizontal cohomology is analyzed. Relations with the Vinogradov spectral sequence are discussed.     

一种薄板弯曲问题的四边形位移单元

本文基于修正势能泛函,引入广义协调的概念,导出了一种具有12个自由度的薄板弯曲四边形位移单元LGC—Q12,这种单元协调性好,列式简单,计算精度高。并且能近似地通过分片检验。     

空间静不定桁架的变形协调条件及求解

根据桁架受载后各杆件的伸长量、各杆件夹角的变化之间的几何关系，以各杆的伸长量和夹角的微小变化为未知量，建立了空间静不定桁架的变形协调条件，并结合实例给出了求解空间静不定桁架的一种计算方法．     

Linear Isotropic Relations in Finite Hyperelasticity: Some General Results

The form of the classical stress–strain relations of linear elasticity are considered here within the context of nonlinear elasticity. For both Cauchy and symmetric Piola-Kirchhoff stresses, conditions are obtained for the associated strain fields so that they are independent of the material constants and compatible with existence of a strain–energy function. These conditions can be integrated in both cases to obtain the most general strain field that satisfies these conditions and the corresponding strain–energy function is obtained. In both cases, a natural choice of form of solution is suggested by the special case of the compatibility conditions being satisfied identically. It will be shown that some strain–energy functions previously introduced in the literature are special cases of the results obtained here. Some recent linear stress–strain relations, proposed in the context of Cauchy elasticity, are examined to see if they are compatible with hyperelasticity.      

Correct Solutions of Plane Elastic Problems for a Half-Plane

Continuous and integrable solutions and one-to-one relationships between boundary forces and displacements are found through the direct integration of the differential equations of the plane elastic problem for a half-plane with boundary conditions for either forces or displacements or with mixed boundary conditions. The necessary equilibrium conditions for forces and the compatibility conditions for displacements that ensure the correctness of the solutions are formulated     

Evaluation of a proficiency test on cadmium and lead in herbal material using assigned reference values

This paper presents an international proficiency testing program (APLAC T065) on two trace elements, cadmium and lead, in an herbal sample, Herba Desmodii Styracifolii. The program was registered with a total of 109 laboratories from 42 countries. The assigned reference values of the analytes for performance assessment were provided by the organizers using an accurate gravimetric isotope dilution inductively coupled plasma-mass spectrometry technique. z-Score was used as the numerical indicator to interpret participants' competence. The between-laboratory variations for cadmium and lead were respectively 18.7% and 19.8% and the consensus values were found to be consistent with the assigned reference values. Twenty-two participants gave at least one unsatisfactory z-score, but the performance of the majority of participants on the analysis of cadmium and lead in herbal matrix was generally good when compared with the assigned reference values.     

Semi-synthetic polysaccharide sulfates as anticoagulant coatings for PET, 1--cellulose sulfate

In the present study, blood-compatible PET surfaces were prepared by coating with anticoagulant cellulose sulfates that were synthesized homogeneously in ionic liquids. The adsorption behavior of polysaccharides on PET films was investigated using QCM-D. It was demonstrated that pre-coating with different amino-group-containing polysaccharides improves the affinity toward cellulose sulfate. Moreover, the effect of different degrees of sulfation on the adsorption process was evaluated. Based on these results, several layer-by-layer coated PET foils were prepared that showed significantly improved blood compatibility compared to the initial untreated material.     

基于权益再融资与策略性债务支付的公司财务困境纾解研究

为了应对公司财务困境问题,在兼顾股东与债权人利益的基础上,采用激励相容理论,构建了基于权益再融资和策略性债务支付的公司定价模型,厘清了权益再融资、债务重组、财务困境及其伴生的再谈判之间的关系,据此提出了一种公司财务困境纾解方案。特别地,给出了策略性债务支付下进行权益再融资的可行性依据,并辅以再谈判手段及股东、债权人双方利益最大化目标,确定了最优重组边界及最优减记息票。分析结果表明:①将策略性债务支付置于财务困境之后、兼容权益再融资的综合方案,可在一定程度上避免策略性债务支付行为的投机性所导致的对公司定价的高估,产生了在一定条件下增加债务价值、放缓信用价差增长速度的效果;②权益再融资成本与信用价差之间呈现倒U型关系;③基于纳什均衡博弈的策略性债务支付减记息票不受流动性及权益再融资的影响,并可保证其处于公司的支付能力之内。