石灰石—石膏湿法烟气脱硫效率影响因素分析

从5个方面分析了影响石灰石—石膏湿法烟气脱硫效率的因素,并对各因素进行了综合探讨。     

表面态对TiO_2纳米晶薄膜光电流的影响

研究 Ti O2 纳米晶薄膜电极的光电化学特性 .通过测定阳极光电流 -时间瞬态光电流响应 ,分析纳米晶薄膜 /溶液界面的光生电荷转移的动力学规律 .光照后的慢电流响应与 Ti O2纳米材料的表面态有关 .导带电子向深能级表面态的传递是造成慢电流响应的原因 .     

Myeloid leukaemia inhibitory factor maintains the developmental potential of embryonic stem cells

Embryonic stem (ES) cells, the totipotent outgrowths of blastocysts, can be cultured and manipulated in vitro and then returned to the embryonic environment where they develop normally and can contribute to all cell lineages. Maintenance of the stem-cell phenotype in vitro requires the presence of a feeder layer of fibroblasts or of a soluble factor, differentiation inhibitory activity (DIA) produced by a number of sources; in the absence of DIA the ES cells differentiate into a wide variety of cell types. We recently noted several similarities between partially purified DIA and a haemopoietic regulator, myeloid leukaemia inhibitory factor (LIF), a molecule which induces differentiation in M1 myeloid leukaemic cells and which we have recently purified, cloned and characterized. We demonstrate here that purified, recombinant LIF can substitute for DIA in the maintenance of totipotent ES cell lines that retain the potential to form chimaeric mice.     

一种改进的复合材料损伤塑性耦合模型

复合材料的损伤和破坏行为是相当复杂的,为了描述在复杂载荷条件下的材料的力学行为,可采用损伤与裂纹面间由摩擦诱导的塑性相结合的研究方法。在现有的复合材料摩擦塑性与损伤的耦合模型的基础上,在平面应力条件下,考虑了剪切应变对损伤能释放率的影响,适当地修正了损伤演化方程,从而建立了一种改进的复合材料损伤与摩擦塑性耦合模型。通过算例讨论了复合材料层板在复杂载荷作用下的力学行为,计算结果不仅反映了材料在加卸载过程中的剪切滞回现象,又反映了材料在一个加卸载循环内损伤值增加的实际情况,并且计算结果对应的理论曲线与试验曲线符合得很好。这种改进的模型除了可以解决复合材料的复杂加载问题,还可推广到材料的疲劳损伤的研究中。     

Stem cells, cancer, and cancer stem cells.

Stem cell biology has come of age. Unequivocal proof that stem cells exist in the haematopoietic system has given way to the prospective isolation of several tissue-specific stem and progenitor cells, the initial delineation of their properties and expressed genetic programmes, and the beginnings of their utility in regenerative medicine. Perhaps the most important and useful property of stem cells is that of self-renewal. Through this property, striking parallels can be found between stem cells and cancer cells: tumours may often originate from the transformation of normal stem cells, similar signalling pathways may regulate self-renewal in stem cells and cancer cells, and cancer cells may include 'cancer stem cells' - rare cells with indefinite potential for self-renewal that drive tumorigenesis.     

氯化1-甲基-3-丁基咪唑的制备与表征

用N-甲基咪唑和氯代正丁烷反应,合成了作为室温离子液体中间体的氯化1-甲基-3-丁基咪唑,对其合成过程进行优化和改进.通过核磁共振谱对氯化1-甲基-3-丁基咪唑进行化学结构的表征,使用差示扫描量热法对合成的中间体进行熔点和熔化热的测定,合成了纯度较高的氯化1-甲基-3-丁基咪唑.     

构建近红外网络分析平台实现从原料到产品的整个生产过程质量监控

建立近红外分析技术在生产过程中的网络分析平台方案,发挥近红外过程分析技术的优点,实现从原材料到产品整个生产过程质量监控,保证产品质量的稳定性、安全性。     

考虑概率参数相关性的电动车悬置系统分析

针对电动车动力总成悬置系统(PMS)参数同时存在不确定性和相关性的复杂情形,本文开展了考虑概率参数相关性的电动车悬置系统固有特性分析研究.首先,分别采用相关系数矩阵和概率不确定变量描述PMS参数的相关性和不确定性;然后,基于蒙特卡洛抽样提出了一种求解概率参数相关情形下PMS固有特性统计矩的蒙特卡洛法(MCM);接着,基...     

Male development of chromosomally female mice transgenic for Sry

The initiation of male development in mammals requires one or more genes on the Y chromosome. A recently isolated gene, termed SRY in humans and Sry in mouse, has many of the genetic and biological properties expected of a Y-located testis-determining gene. It is now shown that Sry on a 14-kilobase genomic DNA fragment is sufficient to induce testis differentiation and subsequent male development when introduced into chromosomally female mouse embryos.