摘要:对枯草芽孢杆菌(Bacillussubtilis)转酮酶(EC2.2.1.1)缺失突变株FBL04-215芽孢形成特性进行了研究,发现与野生型相比较,突变株具有芽孢形成能力下降的生理特性,同时对影响芽孢形成的重要因素—Mn2+进行了研究.%This paper studied sporulation characteristics of Bacillus subtilis transketolase-deficient mutant. The sporulation ability of transketolase -def icient mutant was lower than wild type. The effect of Mn2+ on sporulation was also studied in detail.
摘要:研究不同磁场强度对蚕豆种子根的生长、细胞分裂和染色体形态的影响.实验结果表明,磁场强度在3000~5000GS范围内,根的生长速率最快,根尖细胞分裂指数最高;磁场强度低于3000GS时,对种子根的生长和细胞分裂指数影响不明显;高于5000GS时,蚕豆根的生长速率和有丝分裂指数降低.不同磁场强度对染色体畸变率没有明显的变化.%The paper studied the effect of different magnetic intensity onthe root growth of beans, the cells division and the chromosomal morphology .The results showed that the rate of root growth was the fastest,the cell's mi totic index at point of root was the highest between 3 000~5 000 GS magnetic int ensity.When the magnetic intensity is lower than 3 000 GS, the effect of the ro ot growth and the cell's mitotic index was not obvious.When it is higher than 5 000 GS ,the rate of root growth and mitotic index decreased.The different ma gnetic intensity had no obvious effect on the rate of aberrant of mitotic division.
摘要:对未知参数估计值的方差、解释变量的误删(误加)、多重共线性等问题进行了研究,给出两个重要的结论且进行了严格的理论证明.%The variance of the estimated values of unknowm parameters, underspecification of a regression equation, overspecification of a regression equ ation, mutuality of linearity are discussed. Two important conclusions were proved.
摘要:It is important to have an objective and fair evaluation in suchaspects as teacher's quality,teaching and research. It is also an impor tant measure in training persons qualified to teach. In this paper, we will discuss about how to use quantitative method to evaluate teacher's achievemen ts.%对教师思想品德、教学、科研等进行客观公正的考核是师资管理工作的重要内容,也是师资队伍建设的重要措施,为此,对教师业绩考核中如何采用定量计算的办法进行了探讨.
摘要:The mutagenicity studies on the non-uniform stable and uniformunstable magnetic fields have been done, by utilizing the salmonella mut agenicity test and SOS chromotest. The results show that the fields have no muta genicity.%通过鼠伤寒沙门氏菌组氨酸缺陷型诱变实验及SOS显色诱导实验对非均匀稳恒磁场及均匀交变磁场进行了致突变性研究.结果表明,实验条件无致突变作用.
摘要:Gold is a comprehensive used precious metal. Gold resources inChi na have characteristics as follows:①gold mineral distribution is comprehensive , the types are complete; ②the medium-sized and diminutive deposits are legi onary;③ attendant-gold proportion in gold production is relatively high; ④the resource gross is inadequate. During exploitation and utilization, there are ma ny issues such as that the perambulation level is lower and the resources used i n production are difficult, that the reserve possessive percentage is high but the utilization is lower, that the environment pollution and disorderly digging deposits are serious and so on. The only way to sustainably develop and utilize gold resources is to strengthen geological exploration, resource administrat ion and environment protection.%黄金是具有广泛用途的贵重金属.针对现存问题,如我国黄金资源具有金矿床分布面广、中小型矿床多、黄金生产中伴生金所占的比重较大、资源量不足等特点,以及在开发利用上存在黄金勘查水平较低和生产利用困难、矿山储量占有率高而利用率低、环境污染和乱采滥挖现象等,指出,加强地质勘探、资源管理和黄金生产中环境保护工作,是黄金资源实现合理开发和利用的可持续发展的必由之路.
摘要:西北地区是我国生态环境最脆弱的地区.为了顺利发展西北地区经济,探讨了西北地区生态环境的演变,客观分析了西北生态逐步恶化的原因,进而提出了开发西北必须以生态建设为重点的可持续发展战略.%The organisms' habits environment is the most fragile in thenorth west of China. Through introducing the development and the changes of the organi sms' habits environment, the article submits the sustainable development methods which is the center on the organisms' habits construction to develop the Northw est.
摘要:Sol-gel method is a new material preparation method. There are many advantages of using the method, such as facility briefness, technology being prone to control, higher purity uniformity of products. The fundamental technol ogical process and application of the sol-gel method are summarized.%综述了溶胶-凝胶法的基本原理、过程及其应用前景,溶胶-凝胶法是一种新兴的材料制备方法,具有设备简单、工艺易于控制、制品纯度和均匀度高等优点.
摘要:对分布于吉林省西部干旱草甸上4种旱生植物茎和叶的解剖学研究发现,它们具有适应旱生环境的典型结构特征:植株矮、叶面积小、表皮细胞厚且有较厚的角质层.栅栏组织发达并具环栅结构、栅栏细胞内叶绿体发达等.叶脉外有维管束鞘包围,而且叶有大量的表皮毛.茎中导水组织发达.%On resaerch ,We find that the four types of Xerophyte have typical structural features in adjusting to the arid envirement:short ,small leaves ,thick cuticle, developed surrounding paling tissues,developed chloroplast ins ide paling tissues,etc. Out of their leaves and veins there are surrounding bund le sheath and large amount of villi.There are as well developed conducting tissu es in the stems.