CECE法重水电解分离氚的热力学研究

文章研究了CECE法中D2-含氚重水同位素交换以及电解的热力学问题,即可逆分解电压和2个反应(19-1) 和(19-2)的热力学平衡条件。研究给出了H2O, HDO, D2O, DTO和T2O的可逆分解电压。H2O(0) 与T2O(4)的可逆分解电压的相差为0.047 V,如要保留T2O,则实际的分解电压不能大于H2O的分解电压。同时,导出了这5种氢同位素水的平衡蒸汽压和汽化热与温度(0～100 ℃)的函数关系。从热力学来讲,反应(19-1)和(19-2)的平衡常数都很小,在静态反应中难以实现,如果在流动系统中,则能符合条件Q < K,使反应进行。电解分离氢同位素水的最大的难点是选择性差,可以探索使用光催化分离的方法。     

有固相析出的多效两段蒸发 系统模型与过程模拟

建立了带有冷凝水闪蒸的有固相析出的多效两段蒸发系统的常规设计数学模型,模型将系统的相平衡关系用回归式表达,使模型可以用计算机编程求解,避免了手工计算结合查相图的烦琐的计算过程;利用矩阵方程具有结构清晰和高度模块化的特点,将系统的物料衡算和热量衡算方程组写成矩阵方程的形式,只要保留或舍弃矩阵方程中的相关块矩阵,模型就能代表没有冷凝水闪蒸或没有固相析出的多效两段蒸发系统常规设计模型;采用迭代法结合矩阵法来求解模型,算例表明,冷凝水闪蒸对多效两段蒸发系统是有效的节能措施,算法收敛速度快、收敛稳定性好。     

交通流诱导系统实时方法研究

交通流的实时诱导系统多为建立在单位时间的信息重构,一旦在周期时间内事故发生,则造成行驶车辆正常诱导无法进行。通过对实际交通状况的分析,提出一个新的并且简单可行的解决方案。方案在原有系统中增加了对实时事件突发诱导系统的修正,减少系统应变时间。此方案是建立在现有的诱导基础之上的改进技术,可以在交通流诱导系统中大范围推广应用。     

Facile and environment friendly synthesis of hierarchical BiOCl flowery microspheres with remarkable photocatalytic properties

A facile and environment friendly approach to synthesis of unique hierarchical BiOC1 flowery micro- spheres （FMs） using a biodegradable surfactant polyvinyl alcohol （PVA） was reported herein for the first time. Com- pared to the BiOC1 nanosheets synthesized in the absence of PVA, hierarchical BLOC1 FMs consist of large amounts of interwoven polycrystalline nanosheets that assemble into a porous flowery structure. The formation mechanism of the hierarchical BiOC1 FMs was also proposed, whereby PVA was believed to play a key role in the crystal growth and the formation of the final microstructures. Compared with TiO2- P25 and BiOC1 nanosheets, hierarchical BiOC1 FMs dis- played remarkably enhanced photocatalytic activity, and 20 mg of BiOC1 FMs could completely degrade 50 mL of methyl orange solution （20 rag/L） within 30 min under UV- light irradiation. According to the comprehensive analysis, it can be concluded that the larger specific surface area, porosity, suitable band gap, and the enhanced light absorp- tion capacity may contribute to the remarkably enhanced photocatalytic activity. This facile and green approach to fabricating hierarchical BiOC1 FMs would give vital clues to develop new route for synthesizing other hierarchical structured materials.     

催化裂化反应工艺技术进展

催化裂化工艺是炼油行业高效利用石油资源的一个重要手段。各炼油企业的原料性质差异和对产品分布的要求不同使催化裂化工艺的发展多样化。原油劣质化和环保要求越来越严格是催化裂化工艺发展的推动力;强化重油裂化能力、改善产品分布、提高产品质量、减少污染物排放和提高经济效益是其发展的出发点;提高剂/油比、缩短反应时间、让不同的反应分区进行、将部分待生催化剂循环等是其基本手段。     

独轮自平衡电动车的建模与运动平衡控制

为了设计新型、环保、便捷的智能代步工具,搭建了一款独轮自平衡电动车物理系统。利用拉格朗日方法建立了人车一体的动力学模型,并对系统进行了特性分析。设计了独轮车系统的比例微分(proportional-differential,PD)平衡控制器,并对独轮车系统分别进行了自平衡、冲击干扰和阶跃干扰实验。实验结果表明,独轮自平衡电动车系统具有较好的鲁棒性和操控性,证明设计方案的合理性和有效性。     

强力氨肽对小鼠成纤维细胞的影响

蛋白质对细胞合成和代谢有一定程度的影响,高浓度胺肽含有丰富的氨基酸,通过对实验组和对照组小鼠脸颊、腹部和四肢等部位皮下结缔组织的比较,实验组小鼠上述３ 个部位的成纤维细胞数量和直径与对照组相比均有显著差异,而且细胞外基质成分也比对照组发达实验证明强力氨肽具有促进成纤维细胞的分裂和合成能力,对伤口愈合增强皮下结缔组织的韧性和弹性具有显著作用     

次生栎林蒸腾强度与蒸腾量的研究

采用多元回归分析和灰色关联分析方法,探讨了下蜀次生栎林蒸腾强度与生态因子的相关关系;并采用曲线积分的方法对林分蒸腾量作了估测。结果表明影响蒸腾强度的主要生态因子是温度和净辐射;其次是空气相对湿度和土壤热流通量;风速和土壤含水率的影响很小。次生栎林１９９６年总蒸腾量为４２８．８８ｍｍ;总蒸发散量为８５８．６８ｍｍ,占全年总降雨量的６８．８５％。研究结果为进一步阐明次生栎林的结构和功能提供了理论基础。     

Highly sensitive detection of melamine based on reversed phase liquid chromatography mass spectrometry

In this work, we developed a highly sensitive method to detect melamine based on reversed phase liquid chromatography mass spectrometry. A mass spectrometry compatible ion pair, heptafluorobutyric acid(HFBA), was used to separate melamine by reversed phase liquid chromatography prior to electrospray mass spectrometry. The incorporation of isotope internal standard and multiple reaction monitoring improved the accuracy and linearity of quantification. Based on this strategy, the method limit of quantification was 0.1 ng/g. The limits of quantification were 8 ng/g for liquid milk and 15 ng/g for dry milk powder. This method provided a reproducible and stable approach to sensitive detection and quantification of melamine. Supported by the National Natural Science Foundation of China (Grant No. 30425021) and National High Technology Research and Development Program of China (Grant No. 2007AA02Z334)     

Convergence analysis in sense of Lebesgue-p norm of decentralized non-repetitive iterative learning control for linear large-scale systems

In this paper, a decentralized iterative learning control strategy is embedded into the procedure of hierarchical steady-state optimization for a class of linear large-scale industrial processes which consists of a number of subsystems. The task of the learning controller for each subsystem is to iteratively generate a sequence of upgraded control inputs to take responsibilities of a sequential step functional control signals with distinct scales which are determined by the local decision-making units in the two-layer hierarchical steady-state optimization processing. The objective of the designated strategy is to consecutively improve the transient performance of the system. By means of the generalized Young inequality of convolution integral, the convergence of the learning algorithm is analyzed in the sense of Lebesgue-p norm. It is shown that the inherent feature of system such as the multi-dimensionality and the interaction may influence the convergence of the non-repetitive learning rule. Numerical simulations illustrate the effectiveness of the proposed control scheme and the validity of the conclusion. This research was supported by the National Natural Science Foundation of China under Grant No. F030101–60574021.