Catalytic Pyrolyses of Rayon and the Effect on Activated Carbon Fiber

Introduction Sinceactivatedcarbonfiber(ACF)appearedinUK, ithasbeenstudiedandproducedoncommercialscalefor tensofyears.Owingtoitsspecialporestructures, excellentabsorptionandextensiveuses,ACFhasattached muchimportanceovertheworld[1,2].Butitsapplications arestillgreatlylimitedforitsveryexpensiveprice.RayonnowisthemajorrawmaterialofACFinindustryinthat theproductiontechniquefromrayoniseasyandreliable. Catalystsplayanimportantroleinrayon basedACF smanufacture.Theycanacceleratethedehydrati…     

MOLECULAR CHAIN STRUCTURE AND CRYSTALLINE STRUCTURE OF PB-ET COPOLYESTER

The molecular chain structure and crystalline structure of PB-ET copolyester made by con-densation polymerization are studied by means of ~(13)C nuclear magnetic resonance spectroscopy(~(13)C NMR),dynamic mechanical analysis (DMA),wide angle X-ray scattering (WAXS),depolarized light intensity (DLI) and stress-strain measurement(S-S).It is shown that PB-ETcopolyester is a random copolymer.Because of different ratios of EG(ethylene glycol)to BD(butane diol)in the copolyester,its crystalline forms and mechanical properties vary remarkably.With the increasing amount of BD,its crystallization kinetic parameters n,k and t_(1/2)~(-1) increaserapidly.When EG/BD equals 25/75 (mole ratio),the copolyester has αβ transition as PBTdoes.     

男子手枪慢射项目赛前训练时间控制的研究

在竞技运动训练中存在着许多时间规律,如重大比赛赛前训练阶段构成的时间学特征及时间构成,以及中短期赛前训练中各相关训练学因素的时间学特征及其全过程总体时域。赛前训练对射击运动员的比赛竞技状态有重要影响,通过对广东省慢射运动员不同赛前训练时间安排的研究,为男子手枪慢射运动员赛前训练时间安排实施有效的控制提供理论与实践依据。     

基于熵权–VIKOR及AGA-BP模型的企业绩效评价研究——以我国上市物流企业为例

针对现有的企业绩效评价研究存在评价指标体系维度单一、评价结果时效较短、缺乏对企业未来绩效水平的探讨等问题,以我国上市物流企业为例,从财务及非财务角度构建了我国上市物流企业绩效评价指标体系,并通过熵权–VIKOR算法确定了各评价指标的权重以及各样本企业的期望绩效值。同时,采用自适应遗传算法（adaptive genetic algorithm, AGA）对传统的BP神经网络进行优化,构建了基于AGA-BP神经网络的企业绩效评价和预测模型。最后以36家样本企业数据为基础,对该模型进行训练和测试。测试结果证明了基于AGA-BP神经网络的上市物流企业绩效预测模型的有效性和实用性。