汽车运材费用的多因素分析

本文应用多元统计分析方法对汽车运材费用进行分析，影响运材费用的主要因素按其对单位成本影响的贡献大小排序，依次是单位养路费、单位燃润费、单位保修费和单位大修费．     

草地类型梯度分析

紫泥泉地区位于天山北坡低山带，具有代表性的冬春秋放牧场。本文应用数量分类（ＴＷＩＮＳＰＡＮ）、排序（ＤＣＡ）和回归分析方法研究了草地类型的分类及其分布的梯度规律。研究结果表明：该地区的草地类型按传统分类划分出１８个型，ＴＷＩＮＳＰＡＮ分类结合ＤＣＡ排序归纳出８个型，其中６个型为地带性草地类型，２个型为非地带性草池类型；地带性草地类型沿水热梯度分布，非地带性草地类型沿质地梯度分布。     

Feline Ubiquitin Fusion Protein Genes

Using cDNA from a CRFK cell line as a template, PCR amplification was performed with the Ub1S and poly(dT) primers to isolate feline ubiquitin genes. Sequencing of the 495 bp PCR fragment revealed that the putative amino acids induced by this fragment gave a fusion protein consisting of a ubiquitin polypeptide (76 amino acids) and an extension protein of ribosomal proteins L40 (52 amino acids). The putative amino acid sequence of ubiquitin was identical to those of humans, rats and pigs.The recombinant glutathione S-transferase (GST)–feline ubiquitin fusion proteins were produced in Escherichia coli and purified. The fusion proteins had a molecular weight of about 42 kDa and were detected by immunoblot assay with rabbit anti-ubiquitin antiserum.The mRNAs from heat-shocked and non-heat-shocked cells were subjected to RT-PCR (Ub1S and poly(dT) primers) analysis. The molecular weights of the ubiquitinated proteins in heat-shocked CFRK cells were between 18 kDa and 24 kDa by immunoblot assay.These results suggested that there were more ubiquinated proteins in the heat-shocked CRFK cells than in the pre-heat-shocked cells.     

可持续发展类型与测度的理论探讨

可持续发展的类型划分与可持续发展的测度是可持续发展理论研究的重要内容。科学反应可持续发展的特征 ,有利于可持续发展类型划分 ,是可持续发展测度的依据和目标。本文运用人地关系协调分析法与经济分析法 ,特别是与替代弹性不变生产函数分析法 (C.E.S生产函数 )相结合 ,提出了可持续的人均国内生产总值 ,探讨了可持续发展中人文资本、自然资本相互协调、相互依存的关系特征 ,建立可持续发展测度的指标系统和可持续发展的类型体系     

广州香蕉束顶病毒分离和核酸鉴定

经液氮冷冻、差速离心和蔗糖梯度离心，从广州地区香蕉束顶病株中获得大小为25nm的病毒颗粒，该病毒与香蕉束顶病毒单克隆兔抗血清呈阳性反应，该病毒核酸可被Dnase和S1核酸酶降解，但不能被RNase降解，属于ssDNA ；人子量大小约为1165碱基。     

辽宁西部半干旱地区油松纯林改造的研究

喀左县位于辽宁西部地区，现存大面积油松人工纯林，不仅改善地力和水土保持效益差，而且火险性强、虫害蔓延成灾、生长早期衰退。为改善其林分生态条件，提高林木生长量和综合效益，在中三家镇对25年生油松人工纯林进行改造试验。结果表明，选择山杏、刺槐、沙棘等乔、灌木树种，利用林间空地、林缘隙地、侵蚀沟壑和疏林地造林，在大面积油松纯林连片地区进行窄带状或块状砍伐后造林，5年后效益显著，林分相对湿度提高了2．2％，土壤有机质含量提高5．4％，土壤含水量提高9．8％，减轻土壤容重３％,林分虫害明显下降，油松树高、胸径生长量分别提高22．6％、19．8％。     

Spatial distribution of Aspergillus flavus and its toxigenic strains on commercial cottonseed from south Texas and its relationship to aflatoxin contamination

The structure of Aspergillus flavus communities associated with south Texas cottonseed was determined by analysing samples from 178 truckloads of commercial cottonseed from 35 gins, extending from Fort Bend County in the north to the Rio Grande Valley in the south, from September 1999 to October 2001. The number of colony-forming units (CFU) of A. flavus on the cottonseed, and the percentage of S strain (%S) were both correlated with aflatoxin contamination of cottonseed. The number of CFU differed between both regions and seasons, while %S differed only between regions. Comparison of maps of CFU and %S revealed that CFU shows a higher variation across years, while %S shows higher spatial variation. The Rio Grande Valley had significantly lower CFU and %S strain than the Coastal Bend and Upper Coast regions. Cottonseed produced in 1999 had significantly more A. flavus than that produced in either 2000 or 2001. Identification of factors dictating geographical variation in S-strain incidence may provide insights that will lead to improved aflatoxin management.     

松材线虫病入侵陕西的风险分析

松材线虫病自1982年在我国发现后，扩散和危害呈逐年扩大和加重趋势，严重影响了我国生态安全和经济发展。本文通过对松材线虫病定量的风险分析，得出风险值R=2．775，表明松材线虫病对陕西省而言属于特别危险的林业有害生物，应加强监测、检疫和除治管理，防止传入陕西省并造成扩散危害。     

捻转血矛线虫(H.contortus)ZJ株H11蛋白基因的克隆及序列分析

参照已发表的捻转血矛线虫H11蛋白基因序列设计引物，以H．contortuss ZJ株的总RNA为模板，进行RT—PCR扩增，成功扩增出H11基因。将PCR产物与pUCm—T载体连接后，转化DH5α感受态细胞，筛选阳性克隆并测序。序列分析表明，其核苷酸序列与国外报道的H11基因的同源性为99．5％。编码氨基酸序列具有氨基肽酶的保守序列，推测可使虫体不能获得所必需的氨基酸而导致死亡。