冠军的诞生

162kW，升功率81kW，这是一个多么令人惊讶的数字!要知道这不是超级跑车，它只是—部普通的2．0L排量的民用轿车的数字，而另一个竞争对手仍在使用的2.0L发动机的功率只有85kW，这就是科技的力量。     

环的幂等元与素谱的开闭集

设R是任意带单位元的结合环,L(R)表示Levitzki根,左素理想谱specl(R)是一个弱Zariski拓扑空间。本文主要研究所有包含L(R)的左素理想谱Sl(R)的正规性与环的Gelfand性、Sl(R)的开闭集与环的幂等元的关系。证明了:设R是任意环,对任意Sl(R)的开闭集U,都存在环R一个幂等元e,使得U=Ul(Re)∩Sl(R)。     

几种菊科植物SOD和POD同工酶的比较(简报)

菊花是我国十大名花之一,并成为当今四大鲜切花之一。栽培历史悠久,栽培范围广,品种繁多,目前在世界上已有20 000-25 000个园艺品种,我国有7000个品种以上。同工酶已广泛应用于生物学研究的各个领域中,特别是生理学、分类学、病理学、遗传及育种学。SOD是一种超氧阴离子(O2.-)歧化酶,它存在于植物的细胞质、线粒体和叶绿体中,与植物的种类及器官的衰老程度、线粒体和叶绿体的含量及所处的生长环境有关。     

LabVIEW在快速傅立叶变换中的应用

本文介绍了LabVIEW的基本知识,快速傅立叶变换的基础知识,以及LabVIEW在快速傅立叶变换中的应用。     

应用玉米种子盐溶蛋白方法对大豆种子室内谱带对比的试验

通过应用玉米种子纯度室内鉴定方法对大豆种子品种间进行对比，对不同的品种在同一条件下谱带所表现的不同差异，因而可知此方法对此试验中的大豆品种可以应用于鉴别。     

植物免疫系统新观点

科学家最近研究发现，植物免疫系统的作用不仅局限在一系列特定的广谱响应，还表现出一定的灵活性和弹性，并且对各种病原体产生不同的响应特性。植物免疫系统的这些特征与动物免疫系统具有一定的相似性。     

穗发芽深度对早稻米品质和 RVA谱特征值的影响研究

以3个早稻品种（组合）为材料，采用发芽箱人工诱导模拟穗发芽的方法，研究了不同穗发芽深度对水稻稻米品质和RVA谱特征值的影响。结果表明：穗发芽严重影响稻米品质，发芽引起糙米率、精米率和整精米率下降，垩白粒率增多和垩白大小增大，碱消值降低，糊化温度升高，胶稠度减小，粗蛋白含量降低，其中整精米率下降幅度最大，最大降幅达50％以上，其次是垩白大小。因此发芽严重影响了稻米的加工品质、外观品质和蒸煮品质，营养品质；发芽还使RVA谱的特征值最高黏度和崩解值度减小，降低稻米的食味品质。     

防治玉米叶斑病，必扑尔效果好

必扑尔的产品特点： 杀菌谱很广 必扑尔可以有效杀灭叶斑病、炭疽病、白粉病等病害的病菌；     

Cloning of L-PGDS Gene and Its Expression Pattern in Different Tissues and Testis at Different Development Stages in Cattle-yak

The purpose of this study was to clone the prostaglandin D synthase (L-PGDS) gene and identify its expression pattern in various tissues and testis at different development stages in cattle-yak,in order to provide experimental basis for studying the mechanism of L-PGDS gene in testis development of cattle-yak.The total RNA of heart,liver,spleen,lung,kidney,large intestine,small intestine,gastric,brain and testis at different development stages (fetal,calve tuberty and old) of healthy cattle-yak were extracted by Trizol method.The L-PGDS gene sequence was amplified and cloned by RT-PCR,and analyzed by related biological software.The expression of L-PGDS gene mRNA in different tissues and testicular tissues at different development period of in cattle-yak were detected by Real-time quantitative PCR.The results showed that the length of L-PGDS gene was 624 bp,including the ORF of 576 bp,which encoded 191 amino acids.Homology alignment results showed that L-PGDS gene in cattle-yak had high homology with Bos taurus and Ovis aries,which were 99.28% and 94.00%,respectively.Phylogenetic tree results showed that the relation between cattle-yak and Bos taurus was the closest,followed by Ovis aries and Equus caballus.The L-PGDS protein was an unstable hydrophobic protein,the molecular weight was 21.229 ku,the molecular formula was C₉₅₃H₁₄₇₁N₂₅₁O₂₈₁S₉,the isoelectric point was 6.43,and the instability index was 47.25.The L-PGDS protein had no transmembrane region and no signal peptide.The secondary structure of L-PGDS protein contained alpha helix,random coil and extended chain,the rats of them were 25.65%,53.40% and 20.94%,respectively.L-PGDS gene was highly expressed in testis of cattle-yak,which was extremely significantly higher than that in other tissues (P<0.01).The expression of L-PGDS gene mRNA in testis of cattle-yak increased firstly and then decreased along with age,and with the highest expression in puberty stage,which was extremely significantly higher than that at other periods (P<0.01).This study provided basic data for further study on the mechanism of L-PGDS gene in the development of testis in cattle-yak.     

拖拉机故障几例

1.发动机功率为何突然下降 一台S195柴油机带动一台8千瓦发电机,运行半年无明显异常。后来三天之内输出电压逐渐下降,最后不能带动正常负荷而熄火。检查低压油路来油正常,而喷油声则很微弱,且不连续,转速加快喷油声反而更小。