乳液聚合中单体醋酸乙烯酯与保护胶体聚乙烯醇的接枝反应研究

研究了以聚乙烯醇为保护胶体的醋酸乙烯乳液聚合中,聚乙烯醇与单体的接枝反应。探讨了引发剂用量、聚合反应温度、保护胶体聚合度等因素对接枝反应的影响。     

Possible Energy Network with polygeneration system and CCS for China

On basis of adopting polygeneration systems for power and alternative fuels,capturing CO2 with near zero energy penalties,and storing CO2 on sites,a new kind of Energy Network can integrate energy utilization,CO2 capture,transportation and storage synthetically.Techno-economic analysis of this solution focusing on Inner Mongolia and the Yangtze River Delta districts had been carried with comparison to the chain method for energy utilization and CO2 sequestration.This solution can save 21.5% of energy,and re...     

Preparation,characterization and salt-resistance of a coal based super absorbent composite

Potassium humate was extracted from brown coal.A novel super absorbent composite,poly (acrylic acid-co-acrylamide)/potassium humate (PAA-AM/KHA),was prepared by graft polymerization of acrylic acid,acrylamide and coal based potassium humate using N,N'-methylenebisacrylamide as a crosslinker and potassium peroxydisulfate as an initiator.The effects of reaction temperature,degree of neutralization of the poly (acrylic acid) and the amounts of crosslinker,initiator and potassium humate were investigated.Salt resistance tests were also carried out.The composite prepared under optimal conditions had a potassium humate content of 10% and exhibited a water absorption of 770 g/g in distilled water,and 349,286 and 41 g/g in 0.5 mol/L KC1,MgCl2 and AlCl3 solutions respectively.The results indicate that the salt resistance of PAA-AM/KHA was superior to that of poly (acrylic acid-co-acrylamide) because of the collaborative effect of functional groups of the coal based potassium humate.The PAA-AM/KHA micro powder was characterized by IR spectroscopy and the micrographic surface was characterized by scanning electron microscopy.Introduction of potassium humate into the poly (acrylic acid-co-acrylamide) structure creates a composite more suitable for use as a water-managing material in the renewal of arid and desert environments.The salt resisting property of the composite is improved,production costs are reduced and the growth stimulant effect is still present.     

An improvement to the simulation of phase-change heat-transfer during soil freezing and thawing

A new variable time step method, which is called the backwards calculating time step method, is presented in this paper. It allows numerical simulation of soil freezing and thawing while avoiding "phase change missing and overflowing". A sensitive heat capacity model is introduced through which the calculation errors are analyzed. Then the equation using the self-adjusted time step is presented and solved using finite differences. Through this equation, the time needed for a space cell to reach the phase change point temperature is calculated. Using this time allows the time step to be adjusted so that errors caused by "phase change missing and overflowing" are successfully eliminated. Above all, the obvious features of this method are an accelerated rate for adjusting the time step and simplifing the computations. An actual example proves that this method can accurately calculate the temperature fields during soil freezing and thawing. It is an improvement over traditional methods and can be widely used on com- plicated multi-dimensional phase change problems.     

透过节能减排政策和制度看中国节能减排

随着世界人口的增长、现代工业的高速发展,不可再生资源遭到掠夺式开采、能源消耗几何级增长、环境污染程度大大超出了生态系统的承受能力。如何解决能源短缺与污染严重对经济和社会发展的影响已经成为世界性的难题,我国同样如此。因此,加强对节能减排体系的研究,对我国节能减排工作的开展具有非常重要的意义。对我国节能减排的政策和制度进行剖析,指出了我国节能减排政策、制度以及做法中存在的问题,并提出解决的方法。     

3种花卉在山区及平原越夏的效果评价

通过对金宝剑（Vrieseamarjolcin）、安祖花（Anthuriumandraeanum）和一品红（Euphorbiapulcherrima）3种花卉在萧山区海拔500m山区越夏与海拔9m平原越夏的比较试验,结果显示：山区越夏后,金宝剑的叶片数、叶片长度、叶宽、株高和冠径分别比平原越夏后增长了6．9％,28．6％,7．1％,7．5％和9．7％,叶色较深,生长好又快;安祖花的植株高,花蕾多,叶片深绿、有光泽,其平均株高和单株花蕾数分别比平原越夏后高3．2cm和多0．8个;一品红的平均株高55．8cm,每株最大苞片平均7．8cm,且完全转红,达到市场销售的要求,而平原越夏后则出现下部叶片掉落的现象（平均株高57．1cm,每株最大苞片平均7．2cm）,不完全转红,不能形成成品,达不到市场销售的要求。表明这三种花卉在山区越夏的生长情况都要好于平原越夏。     

基于Kanai-Tajimi模型的地震作用荷载新型识别方法

目的研究一种识别地震作用荷载的方法,为地震作用荷载的识别与相应结构的动力特性、损伤的识别提供一种新的途径,进一步为结构的安全性、损伤进程和耐久性等研究提供理论参考.方法利用Kanai-Tajimi模型将单位强度白噪声过程模拟为未知的地震作用,并将其作用在结构上,然后根据数值模拟计算得到的结构体系响应作为观测量,采用Kalman滤波对未知荷载状态加以识别.结果最终可以利用结构的加速度响应反演得出地震作用的等效荷载,在人工添加5%观测噪声的条件下,最大误差率为7%左右,而在人工添加10%观测噪声的条件下,最大误差率为8%左右.结论通过算例的验证,说明笔者所采用的方法精度较高,获得了较好的识别效果.     

Bone Tissue Response to the Bone-like Tissue Coating on Titanium

The objective of this study was to investigate the effects of mineralized bone nodules, formed in vitro by bone marrow stromal cells(BMSCs), on the new bone formation in bone defect and on implant surface. The mineralized bone nodules were generated by culture of Lewis rats BMSCs on titanium disks in osteogenic induction medium. The gap-healing animal model was used to create the bone defect facing the disk. The titanium disks in the presence of B group or in the absence of NB group bone nodules were randomly placed into one of the rat distal femurs. This self-control design was used to compare the bone formation in defects and on titanium surface, by Micro-CT, fluorescence staining, histological and histomorphometric analysis. The new bone formation parameters in bone defect area of B group were significantly higher than those of NB group at 2 weeks, including bone volume fraction, trabecular thickness and bone area ratio. The bone nodules pre-stained with Alizarin red disappeared mostly at 2 weeks, while the red fluorescence reappeared in the newly formed bone away from the disk surface. For the bone-implant contact, B group showed lower values than NB group at 2 weeks, but no significant difference was found at 4 weeks. Our results indicate that the mineralized bone nodules can be resorbed in vivo and promote the early osteogenesis in the bone defects, and bone nodules may be applicable for new bone generation in bone defect or modification of tissue engineering scaffold.     

民族传统体育项目引入高校体育课的研究

在高校开展少数民族传统优秀体育项目教学,不仅能使少数民族传统体育走向规范化、科学化,较好地展现学生的运动能力,培养民族文化情感,激发民族热情,更重要的是还能提高学生的身心健康和综合素质,有利于对民族传统体育的继承、发展和广泛地传播。     

红色文化:马克思主义中国化的文化棱镜

马克思主义基本原理的理论自觉、中国传统文化的文化自觉、人民群众的实践自觉的三者和谐互动与有机统一,创造与发展了中国主流意识形态与文化的特殊形态,二者构成了马克思主义中国化历程中的两个主要面相,在此进程中,生成了两种主要形态,即中国化的马克思主义理论形态和以革命遗迹为"底板"的红色文化形态。作为一种特殊的文化形态,红色文化不仅是马克思主义中国化的文化自觉和文化再造的产物,也是继续推进马克思主义中国化的文化展望的对象。