机帆渔船主机余热锅灶的试验研究

为了节约全国每年约10万吨的渔船炊事用油，文章从我国大、小渔船组成的现状出发，根据中，小渔船的特点，分析现有余热锅炉用于渔船的利弊。提出了研制适于在中、小渔船普遍推广的余热锅灶的设计思想。为此必须解决设计、制造与试验的一系列问题。经过大量的实验室台架试验与实船试验，终于研制出YGIH与YG2L两种样机。经省级技术鉴定认为：该锅灶适用于机帆渔船，一般主机性能无不良影响，节能及经济效益显著，有推广应用价值。     

燃油磁化节油器节油机理探讨

七十年代中期，燃油磁化节能技术首先出现在日本，当时在燃油锅炉中试用中发现，它可以减少排气烟尘及NOx含量，降低空气(D2)供应量、排烟热损失及引风机的动力消耗，从而达到节能与减少环境污染的目的。随后，人们才用现有的理论来解释其节油机理。但这种解释带有假设的性质，还有待试验来证明。     

宁夏银古高速公路绿化带背景树选择及造林技术

银古（银川——古窑子）高速公路位于银川市东侧，是青岛——济南——银川公路（宁夏境内）的重要组成部分，同时也是宁夏规划的“三纵六横”干线公路网的重要组成部分。银古高速公路绿化工程建设对绿化、美化高速公路，完善国道、省道绿化做出了示范样板，同时，也是为了迎接第七届全国少数民族运动会在宁夏的举行，将该段（银川——河东机场段）建成“样板路、景观路、园林路”，使从东大门进入银川的人们对银川有一个初步印象，以此展示“塞上江南、高原湖城、凤凰城”的魅力。     

Identification of the essential catalytic residues and selectivity-related residues of maltooligosyltrehalose trehalohydrolase from the thermophilic archaeon Sulfolobus solfataricus ATCC 35092

Maltooligosyltrehalose trehalohydrolase (MTHase) catalyzes the release of trehalose by cleaving the alpha-1,4-glucosidic linkage next to the alpha-1,1-linked terminal disaccharide of maltooligosyltrehalose. Mutations at residues D255, E286, and D380 were constructed to identify the essential catalytic residues of MTHase, while mutations at residues W218, A259, Y328, F355, and R356 were constructed to identify selectivity-related residues of the enzyme. The specific activities of the purified D255A, E286A, and D380A MTHases were only 0.15, 0.09 and 0.01%, respectively, of that of wild-type MTHase, suggesting that these three residues are essential catalytic residues. Compared with wild-type MTHase, A259S, Y328F, F355Y, and R356K MTHases had increased selectivity ratios, which were defined as the ratios of the catalytic efficiencies for glucose formation to those for trehalose formation in the hydrolysis of maltooligosaccharides and maltooligosyltrehaloses, respectively, while W218A and W218F MTHases had decreased selectivity ratios. When starch digestion was carried out at 75 degrees C and wild-type and mutant MTHases were, respectively, used with isoamylase and maltooligosyltrehalose synthase (MTSase), the ratios of initial rates of glucose formation to those of trehalose formation were inversely correlated to the peak trehalose yields.     

Fault diagnosis of rotating machinery based on fuzzy clusteringoptimized by chaos embedded particle swarm optimization

A method of weighted fuzzy clustering optimized by chaos embedded particle swarm algorithm(CPSO) is put forward and applied in vibration fault diagnosis of rotating machinery. In the method, CPSO is used to displace the traditional stochastic-gradient algorithm to optimize parameters of weighted fuzzy C-means (WFCM). The best clustering num and clustering centers are automatically attained according to clustering validity function. The experimental results show that the method effectively increases the convergence velocity and precision of WFCM and so does the correctness rate of fault diagnosis for rotating machinery.     

犬瘟热小议

1前言 犬瘟热是一种分布于世界各地,主要发生于幼犬的疾病,有高度的接触传染性,也见于狼、狐狸、貂等动物.据查,新疆犬瘟热的流行发生于70年代初,最早在伊犁发现,且死亡率极高,而乌鲁木齐地区犬瘟热的发现则在90年代初,到目前为止,乌鲁木齐地区已成为犬瘟热的高发区.     

Genetic variations and sequences analysis of MTATP6 and MTATP8 genes among different Chinese pig breeds

To investigate the genetic variations of mtATP6 and mtATP8 genes among different Chinese pig breeds, two fragments of 425 and 743 bp containing the whole coding region of mtATP8 and mtATP6 genes were amplified with 805 individuals from 23 Chinese local pig breeds, three types of Chinese wild boars and three European pig breeds. Sequence comparison identified a total number of 17 substitutions including six variable sites in mtATP8 and eleven substitutions in mtATP6 gene. The restriction enzyme Fok I revealed four polymorphic sites (nt8086, 8176, 8514 and 7784), and four RFLP haplotype patterns (A, B, C and D) were identified in mtATP6 and mtATP8 genes among all tested samples. Our data showed AC combined haplotype originated from Asia and BD was regarded as European origin. The average frequency of Asian mtDNA haplotypes was 38.3% across the investigated European breeds but varied within each breeds (13.3～76.7%). Phylogenetic analyses were performed also considering some published sequences in the databases; the sequences were divided into three distinct groups, denoted A, E1, and E2. The Asian AC haplotype existed among the European domestic pigs was fully consistent with the results of previous molecular studies and well-documented history. This study will help us to better understand the genetic variations of mitochondrial genes among different Chinese pig breeds.     

棉蚜危害损失和经济阈值的研究现状

经济阈值 ,是害虫化学防治的基本依据 ,是有害生物综合治理的重要内容 ,也是保护农业生态环境的综合指标之一 ,八十年代以来一直是国内外研究的热点问题[1～ 3] ,但在新疆相关报道甚少。棉蚜的危害在本地区较为突出 ,造成棉花大面积减产 ,经济损失惨重 ,本地区为独特的干旱—荒漠—绿洲型气候环境 ,对于棉蚜的防治 ,拟采用化学防治 ,或采用天敌控制 ,没有估算数据作依据。本文结合相关文献资料和本地区的棉花生产实际与水平 ,从不同角度对棉蚜危害损失和经济阈值进行了初略估算。1　棉蚜危害及其危害指标的研究1 .1　棉蚜的危害棉蚜对棉花的…