Synthesis and characterization of novel poly (phthalazinone ether ketone)s containing alkyl pendants

目的合成既具有好的溶解性又具有优异的热稳定性的聚(二氮杂萘酮醚酮)。方法通过分子设计,将烷基取代基引入到聚(二氮杂萘酮醚酮)的分子链中。结果通过芳基亲核取代缩聚反应合成一系列带有烷基取代基的新型聚(二氮杂萘酮醚酮)。这种聚(二氮杂萘酮醚酮)室温下可全溶于NMP,DMAc,DMF,Py,CHCl3等极性溶剂中。在氮气中,10%失重高于454℃,玻璃化转变温度范围为208～236℃。结论该方法适宜于将来高性能工程塑料的合成。     

一类非本原代换系统的混沌性态

研究符号集{0,1}上的非本原且非等长代换ζ诱导的系统, 这里ζ(0)=0a₁…a_p-1, ζ(1)=1,…,1, 证明了该系统是Li-Yorke混沌当且
仅当存在i>0, 使得a_i=0; 并通过对符号出现频率的分析, 给出了诱导系统不是分布混沌的一个充分条件.     

基于VES生产函数的经济预测模型与应用

生产函数一直是经济学研究与应用中一个活跃的领域,文中就变替代弹性生产函数VES的两种情形给出经济预测模型。由于模型是非线性的,参数估计一般采用线性化的方法近似估计,在预测上多数情况存在较大的误差,所以文中利用非线性回归方法,非常好地给出最佳估计值,以使预测误差最小。     

Recent progress on the hydrogen storage properties of ZrCo-based alloys applied in International Thermonuclear Experimental Reactor (ITER)

Under the development of International Thermonuclear Experimental Reactor (ITER) system aimed at realizing the controllable fusion reaction to solve the energy crisis fundamentally, there is an urgent need to find an appropriate material for tritium handling. ZrCo alloy is considered to be a promising candidate for the storage and delivery of hydrogen isotopes due to the favorable characteristics such as low plateau pressure for absorption, high dissociation pressure at moderate temperature and better ability of trapping 3He. However, the hydrogen induced disproportionation and the slower recovery/deliverty rate of ZrCo-based alloys have limited their further application in ITER system. This review summarizes the efforts towards enhancing the hydrogen storage properties of ZrCo-based alloys including element substitution, surface modification, disproportionation mechanism investigation and the isotope effect study. Element substitution and surface modification play positive role to improve the anti-disproportionation ability and kinetic property of the alloys. However, the ZrCo-based alloys require to be further modified by more attempts such as new composition, novelty modification method or catalyst addition in order to better satisfy the application demands for tritium handling. Moreover, new insight for further understanding the inner disproportionation mechanisms of this material is needed by combining the advance characterization and theoretical analysis, which is in favor of addressing the disproportionation problem of the ZrCo-based alloys essentially.     

Hydroxyapatites enriched in silicon – Bioceramic materials for biomedical and pharmaceutical applications

Hydroxyapatite (Ca10(PO4)6(OH)2, abbreviated as HA) plays a crucial role in implantology, dentistry and bone surgery. Due to its considerable similarity to the inorganic fraction of the mineralized tissues (bones, enamel and dentin), it is used as component in many bone substitutes, coatings of metallic implants and dental materials. Biomaterial engineering often takes advantage of HA capacity for partial ion substitution because the incorporation of different ions in the HA structure leads to materials with improved biological or physicochemical properties. The objective of the work is to provide an overview of current knowledge about apatite materials substituted with silicon ions. Although the exact mechanism of action of silicon in the bone formation process has not been fully elucidated, research has shown beneficial effects of this element on bone matrix mineralization as well as on collagen type I synthesis and stabilization. The paper gives an account of the functions of silicon in bone tissue and outlines the present state of research on synthetic HA containing silicate ions (Si-HA). Finally, methods of HA production as well as potential and actual applications of HA materials modified with silicon ions are discussed.     

供应失效风险下可替代原材料供应网络的设计问题

研究了供应失效风险环境下可替代原材料的三级供应网络设计问题,供应网络存在由外界干扰而导致供应失效的风险.在保证供应网络弹性水平前提下,为最小化供应网络的期望成本,建立了混合整数规划模型以描述问题并使用优化软件CPLEX进行求解.通过对算例的实验分析,检验了原材料可替代性在供应失效情况下对供应网络的影响.实验结果显示,在供应失效风险环境下,原材料可替代性总是可以降低供应网络的运营成本;能同时供应两种原材料的供应商在与只能供应一种原材料的供应商的竞争中处于明显有利的地位.     

用量子化学方法研究烷基糖苷的反应机理

用量子化学的方法研究烷基糖苷反的机理，计算表明：4号位的C具有较高的正电性，而反应历程的计算表明该反应是个活化能比较高的反应。     

对我国居民消费偏好参数的估计

分两时期对我国居民消费的时间偏好参数ρ和跨期替代弹性1/θ进行估计：1979-1988；ρ=0.072262,1/θ=90.5141202(θ=0.011048);1991-1998;ρ=0.04125,1/θ=4.64507(θ=0.215282)。两个时期的参数估计结果表明；我国居民消费正从单期消费方式向跨期消费方式转变。     

2-烷基-取代苯并咪唑的合成及结构表征

根据Ｌａｄｅｎｂｕｒｇ方法，以邻苯二胺类化合物、脂肪酸为原料，合成２烷基取代苯并咪唑，通过选择反应物配比等，获得了一条较满意的合成路线。通过熔点测定、红外光谱、质谱等方法，对产物进行了结构认证。     

新型表面活性剂烷基糖苷合成研究进展

综述了烷基糖苷（APG）的特性、合成机理、合成方法及国内外的研究进展．针对目前我国合成烷基糖苷的现状，指出在合成烷基糖苷中遇到的一些问题，并提出了解决办法．