白银市工业废水和淡水中的原生动物及水质评价

笔者于1988年3～6月调查了甘肃省白银市工业废水、生活废水和公园湖水中的原生动物.共选择了14个不同水质区域采水样,然后带回室内活体镜检,鉴定出58种原生动物,隶属于植鞭、动鞭、根足、动基片、多膜及寡膜等6纲,其中工业废水中的优势种为梨波豆虫和尾波豆虫,常见种为气球屋滴虫等,均属于多污带至α-中污带生活种类,表明该区的工业废水污染严重.这种用原生动物对水质污染度所作的评价与废水中有害成分的化学分析结果相一致,说明原生动物可以作为宏观评价废水污染程度的指示生物.     

小雁塔日晷初探

本文为小雁塔日晷定了名,并从构造原理、使用方法、年代推断三方面进行探讨,认为它是赤道式日晷,是隋唐时代的物品。     

无孔型轧制时轧件展宽的研究

本文对无孔型轧制时轧件展宽进行了实验研究和理论分析,在定量分析歪斜轧件轧制时轧件单侧展宽的基础上,采用刚-塑性材料变分原理对歪斜轧件的轧制变形过程进行了解析,通过曲线拟合将最接近真实速度场的数值解表示成了具体的函数表达式,推导了无孔型轧制时轧件宽展系数的理论计算公式。理论计算的结果与实验结果符合很好。     

边界积分方程数值解法及其应用(Ⅱ)

本文推广了中的结果,对于三维问题,利用多元插值和边界型求积公式给出边界积分方程一种新的数值解法。     

方形柱体外侧自然对流换热的干涉仪研究

本文用Mach-Zehnder干涉仪对置于空气中水平方形柱体的大空间自然对流换热进行了系统的实验研究.得到了柱体底面与水平线成各种倾角下的温度场;整理了不同倾角下平均Nu数随Ra数变化的关系式;分析了底面倾角对整体换热影响的机理,得出了倾角等于45°时换热最强的结论;分析了不同倾角下局部Nu数沿壁面变化的原因,尖角对换热的影响.并对自然对流流动分离进行了探讨,认为方形柱体在各种倾角下,Ra数超过一定值时,均会产生流动分离,分离的可能性随Ra数的增高而加大.     

创建学习型城市的思考

建设学习型城市的最终目的，就是为了不断提高市民的综合素质，促进人的全面发展，进而推动经济、科技、文化的全面发展。建设学习型组织，不能简单地等同于传统的一般性的学习方式的改进，是一场深刻的管理革命。在推进教育现代化、社会化，其主旨不能等同于打造“大学城”，应把构建终身教育体系作为创建学习型城市的重大目标。     

Isolation and Characterization of Phytoene Desaturase cDNA from Stigma of Crocus sativus

Phytoene desatumse (PDS) has recently been identified as an important enzyme in carotenoid biosynthesis pathway. A cDNA clone encoding phytoene desaturase gene is isolated from stigma of saffron (Crocus sativus L. ) using RT-PCR technique. Sequence analysis shows 85% similarity to Narcissus pseudonarcissus, 79% to Zea mays, 78% to Arabidopsis thaliana, 77% to Lycopersicon esculentum. A new full-length cDNA is obtained by 5 ‘-RACE and 3‘ -RACE techniques. The cDNA is 2149bp long with an open reading frame of 1697bp, which encodes a polypeptide of 565 amino acids. Southern analy-sis shows that the PDS gene is a single copy in saffron. Northern blot analysis shows higher expression level of PDS gene in stigma and anther than in leaves and stem.     

Experimental investigation of integrated air purifying technology for bioaerosol removal and inactivation in central air-conditioning system

In this research, high voltage static electricity and ultraviolet technologies were integrated to an air purifying device which can be used to trap and kill airborne bacteria and viruses in central air-conditioning systems. An experimental platform was built to mimic the central air system, in which the efficacy of the newly built device was examined. In addition to the standard physical and chemical tests, bacteriophages were used to simulate airborne viruses in the experimental system. The bacteriophage suspension was aerosolized into the air with ultrasonic wave atomization. The result showed that more than 86% removal efficiency of micro-particles (<10 micron in diameter) were removed after the device was in operation in a building and more than 95% of bacteriophages in the experimental system. It is concluded that the integrated air purifier is suitable for controlling air quality and preventing virus transmission through the central air system.