氮气流量对金刚石膜生长的影响

采用电子辅助热灯丝化学气相沉积（EA-CVD）方法沉积大面积金刚石膜,在金刚石膜的沉积过程中,氮气流量对金刚石膜沉积的影响会直接影响着金刚石膜的生长和质量。用Raman等手段对金刚石膜的生长特性进行了表征。     

Effects of aFGF on rat kidney in hypothermic preservation

目的:探讨酸性成纤维细胞生长因子(aFGF)对大鼠离体肾脏的低温保存效果的影响.方法:24只Wistar大鼠随机均分成高渗枸橼酸盐腺嘌呤液(HCA)对照组和aFGF复方保存液试验组:HCA液中含40 μg/L aFGF.采用腹主动脉插管原位灌注法,分别用HCA保存液和aFGF复方保存液灌洗并4℃低温保存肾脏.24、72 h后检测保存液pH值变化,以及肾脏组织丙二醛(MDA)、乳酸脱氢酶(LDH)和谷草转氨酶(GOT)水平的变化,并进行肾脏组织病理学检查.结果:肾脏低温保存24、72 h后,试验组保存液pH值均高于对照组(P＜0.05),肾组织MDA水平均低于对照组(P＜0.01);试验组肾组织LDH及GOT水平在24h和对照组无明显差异,而72 h明显低于对照组(P＜0.05).形态学观察结果显示,实验组肾脏损伤较对照组明显减轻.结论:aFGF能改善肾脏的保存效果,并可延长肾脏的保存时间.     

甲烷浓度对大面积金刚石膜生长的影响

采用电子辅助热灯丝化学气相沉积(EA.CVD)方法沉积大面积金刚石膜,在金刚石膜的沉积过程中,碳源浓度的变化会直接影响着金刚石膜的生长和质量.使用Raman,SEM等手段对金刚石膜的生长特性进行了表征.     

米非司酮对晚孕大鼠肾超微结构的影响

目的 :探讨米非司酮对晚孕大鼠肾超微结构的影响。方法 :将妊娠 2 0dWistar大鼠 10只 ,随机分实验组与对照组 ,每组各 5只 ,灌胃法饲予实验组米非司酮 (11 5± 1 0 )mg /只 ,对照组每只给予食用麻油 1mL ,分娩后处死大鼠 ,取右侧肾脏作电镜观察。结果 :与对照组相比 ,实验组肾小体无明显改变 ,大部分肾小管上皮正常 ,局部肾小管上皮细胞出现胞质水肿 ,线粒体肿胀 ,嵴断裂 ,肾间质水肿增宽 ,间质细胞肿胀 ,甚至出现胞膜破裂、染色质边聚、核浓缩等坏死性改变。结论 :单剂量米非司酮用于晚孕引产可造成大鼠肾组织损伤。     

甲烷浓度对大面积金刚石膜生长的影响

采用电子辅助热灯丝化学气相沉积(EA.CVD)方法沉积大面积金刚石膜,在金刚石膜的沉积过程中,碳源浓度的变化会直接影响着金刚石膜的生长和质量。使用Raman,SEM等手段对金刚石膜的生长特性进行了表征。     

Influence of the cobalt concentration on optical and magnetic properties of zinc oxide

A series of Co-doped ZnO thin films have been prepared by direct current reactive magnetron sputtering on glass substrates.The structural characterization by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) gave no evidence of second phase formation.The qualitative composition and chemical state were characterized by energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectronic spectrometry (XPS),respectively.The results confirmed that Co was incorporated as Co3+,occupying the ...     

Similarity of the nucleotide sequences of rat alpha-lactalbumin and chicken lysozyme genes

alpha-Lactalbumin (alpha-LA) is a milk protein that interacts with the enzyme galactosyltransferase, modifying its substrate specificity in a way which promotes the transfer of galactose to glucose, resulting in a way which promotes the transfer of galactose to glucose, resulting in a beta-1----4 glycosidic linkage and the synthesis of lactose. Lysozyme, an enzyme which catalyses the hydrolysis of a beta-1----4 glycosidic linkage in polysaccharides, has been shown to be structurally related to alpha-LA and it has been proposed that they have arisen from a common ancestral gene. To compare their evolutionary relationships, we report here the complete nucleotide sequence of the rat alpha-LA gene, including its 5'-flanking sequences, and compare its gene structure with the chicken egg-white lysozyme gene. Both genes contain three introns at similar positions. The first three exons of the two genes have similar nucleotide sequences. The fourth exon of alpha-LA, which partly codes for the C-terminal residues of the protein, essential for its interaction with galactosyltransferase, is markedly different from the corresponding exon of the lysozyme gene and is preceded by two (TG)n repeats.     

废气燃烧器结构对流动和排放物浓度的影响

为了提高废气处理燃烧器喷嘴的使用寿命、降低排放物中NOx的浓度,采用Realizablek-ε模型对废气处理燃烧器三维流动和燃烧进行了数值模拟.结果显示燃烧室内的流动、燃烧、化学反应以及排放物中NOx的浓度与燃烧器的导流片角度和燃烧器结构密切相关,包括内部流道的形状和面积.据此提出了燃烧器的两种结构修改方案.数值模拟结果表明当去掉导流片从而增大空气流通截面积并减小流动阻力后,燃烧器内的速度和压力分布合理,高温区位置后移,燃烧和化学反应效率提高,排放物NOx的浓度明显降低.其中一种结构改进的燃烧器投入使用后,经检测NOx的浓度减少9.5%.     

煤矸石堆放对周围耕作层土壤中重金属含量的影响

煤矸石地表堆放常会造成周围耕作层土壤的重金属污染,且这种污染可为植物所富集,并通过食物链危害人类健康。本文以陕西白水煤矿为例,通过对煤矸石及其周围耕作层土壤中Cr,Cu,Cd,Zn 4种重金属全量和有效态含量的测定,研究了煤矸石堆放对周边耕作层中重金属含量的影响。研究表明:矸石样与土样中四种重金属的含量均高于当地的土壤本底值,煤矸石的堆放使得周边耕作层受到了不同程度的重金属污染;随着距矸石堆距离的增大,土壤中重金属含量逐渐减小,且下风向区域重金属含量高于等距离的上风向区域;在四种重金属元素中,Cd的有效态含量占全量的比率最高,具有最强的活性,最易于被植物吸收,其污染风险也最大。     

Influence of solution concentration and temperature on the dissolution process and the internal structure of glauberite

Although transport in porous media under the influence of chemistry and temperature is a common phenomenon, the dissolution and internal structure evolution of glauberite during in-situ mining have been unique and challenging. This uniqueness indicates the complexity of mineral dissolutions, whereas the challenge represents the characterization of pore development and evolution during the dissolution processes. To investigate the microstructure development of glauberite under the influence of chemistry and temperature, experimental studies were performed with fine cuboid specimens of 4 mm×4 mm×9 mm soaked in solutions of different concentrations (fresh water, half-saturated, and saturated brine). The evolutions of internal structures were monitored through a micro computed tomography system. The statistical analysis indicated that the concentration and temperature of solutions significantly influenced the evolutions of pore size, porosity, and specific surface area of glauberite. The results showed that the increase in the rates of pore size, porosity, and specific surface area declined with time when glauberite was saturated in fresh water. The main reason for pore parameter variation is the differential concentration of solution. However, in the half-saturated and saturated solutions, the increase in rate increased with time. These observations suggest that the chloride ions contained in the saline solution could facilitate the dissolution of glauberite, whereas the existence of salt effect could contribute to the dissolution of calcium sulfate. Compared with the results at 20℃ and 65℃, the studied parameters of glauberite have dramatically decreased when the mineral was soaked in the solutions at high temperature (95℃). This function was most striking in fresh water. The dissolution of glauberite soaked in fresh water or half-saturated brine solution was conditioned by the temperature and solution concentration. However, the dissolution of glauberite was less influenced by temperature at high concentrations. These findings may feature significant implication for the effective recovery of mineral resources by in-situ solution mining method.     

烘焙和通风对室内VOC浓度分布的影响及预测

为了研究烘焙温度和通风量对室内建材散发挥发性有机化合物(VOC)以及室内VOC浓度分布的影响,对现有的VOC散发和传递模型进行了改进.引入温度对建材中VOC的传质系数的影响,并采用文献中的实验数据验证了该模型的正确性.应用该模型计算了建材内部和室内空气中VOC浓度变化.结果表明,换气次数的提高能够加强空气中VOC的稀释,烘焙温度的升高能够加强材料内VOC的传质速率,使VOC向外扩散速率加快,降低建材中剩余VOC的含量,从根源上解决VOC的长期散发问题.从理论上提出和验证了间歇通风烘焙方法是有效降低室内VOC浓度的措施.     

煤浆浓度对油煤浆流变特性和表观黏度的影响

煤浆质量分数是影响油煤浆流变特性的主要因素之一。文中研究了煤浆质量分数对内蒙古胜利褐煤与液化起始溶剂和循环溶剂配制成的油煤浆的流变特性和表观黏度的影响。采用NXS-11A型旋转黏度计测量煤浆体系在30～70℃时在不同剪切速率下的剪切应力和表观黏度,绘制煤浆体系流变曲线和黏度曲线,分析了流变和黏度特性。结果表明:在实验条件下胜利褐煤起始溶剂油煤浆和循环溶剂油煤浆都符合宾汉流体的特征;油煤浆体系的塑性黏度、屈服应力和表观黏度都随煤浆质量分数的增大而增大,煤浆的表观黏度与煤浆质量分数之间呈指数增长型关系,当煤浆质量分数超过一定数值范围后,煤浆体系的表观黏度会急剧上升。     

Cl~-含量对2A12铝合金初期腐蚀行为的影响

通过干湿周浸加速实验方法、扫描电镜观察和电化学阻抗谱测试技术,研究了2A12铝合金的初期腐蚀规律与电化学行为. 实验结果表明,干湿周浸48h后,所有Cl~-溶液中试样都发生了明显的点蚀. 提高Cl~-含量可以促进点蚀的形成和发展,同时腐蚀产物增多. 当Cl~-含量低时,腐蚀过程主要受电荷转移电阻控制;随Cl~-含量增加,其电化学特征转变为受电荷转移电阻和Warburg阻抗扩散混合控制.