临夏干旱与厄尔尼诺和拉尼娜事件的相关分析

根据临夏地区1950—2012年63年的气候资料,进行对厄尔尼诺、拉尼娜事件与临夏地区干旱的相关分析。结果表明：厄尔尼诺与拉尼娜事件与临夏降水有显著地相关关系。其置信水平达到99％。厄尔尼诺与临夏地区降水成负相关,降水平均减少量为9．1％～26.4％,有86．9％的年份符合这一规律。拉尼娜事件与临夏地区降水成正相关,降水平均增加量为9．7％～36．6％,有78．9％的年份符合这一规律。在每个年代的初期,临夏地区降水偏少几率较大,降水平均减少量为16．5％,厄尔尼诺事件出现的几率较大,为56．6％。     

国内外降雨侵蚀力简易计算方法的比较

降雨是引起土壤侵蚀的主要动力 ,用 EI30 指标度量。计算 EI30 时 ,需要降雨过程资料 ,而且计算繁琐和费时 ,为此 ,很多学者采用常规降雨资料计算降雨侵蚀力的简易算法。它们往往利用区域资料经验拟合求得 ,如要推广使用 ,需要进行验证。利用我国 10个气象站降雨过程和常规降雨资料 ,通过对国内外 9种比较有代表性的多年平均年降雨侵蚀力简易计算方法的比较 ,建议采用年雨量的指数函数形式作为估算我国多年平均年降雨侵蚀力的简易计算方法。为保证计算结果的区域稳定性 ,应分不同区域进行拟合。     

近49 a乌鲁木齐气候变化及其与EI Nino/La Nina事件的关系

利用乌鲁木齐气象站1961－2009年的逐月平均气温、降水量和风速以及EI Nino/La Nina事件统计数据,采用趋势线法和统计分析等方法,研究近49 a来乌鲁木齐气候变化与EI Nino/La Nina事件的关系。结果表明：49 a来乌鲁木齐降水量和气温均有所增加,风速具有一定的下降趋势;气候向暖湿化方向转变。1961－2009年共有16个厄尔尼诺事件年,13个拉尼娜事件年。EI Nino/La Nina事件影响乌鲁木齐季节降水量、年平均气温和风速。在厄尔尼诺年,乌鲁木齐冬季降水偏少、风速偏小、年平均气温偏高、容易形成暖冬,且易发生旱灾。在拉尼娜事件年,乌鲁木齐春季或夏季往往降水偏多、风速偏大、易遭遇洪水、寒潮和风灾。     

珠江三角洲城市群生态状况变化遥感评价

为了解珠江三角洲城市群的生态状况,基于珠江三角洲城市群2006年和2016年的Landsat卫星影像,对比、分析EI法与RSEI法对珠江三角洲城市群生态状况的评价,分析珠江三角洲城市群的生态状况及动态变化。结果表明,EI法与RSEI法评价珠江三角洲城市群生态状况结果差异不明显,RSEI法能有效反映城市群的生态状况。2006年珠江三角洲城市群生态状况主要受湿度指标影响,2016年生态状况主要受绿度指标影响。2006年珠江三角洲城市群生态状况以良为主,2016年以良和优为主。2006-2016年,珠江三角洲城市群生态状况不断改善,有向优、良转变的趋势,生态状况改善的地区主要分布在城市群边缘、植被盖度较高或高海拔的地区,占总面积的48.71%;生态状况变差的地区主要分布在城市群中部发展较快的、密集居民区和工业基地等人类活动频繁的地区,占总面积的6.42%。     

Metabolite profiling of the response to high-nitrogen fertilizer during grain development of bread wheat (Triticum aestivum L.)

Wheat yield and quality are dependent largely on nitrogen (N) availability. In this study, we performed the first metabolomic analysis of the response to high-N fertilizer during wheat grain development using non-targeted gas chromatography-mass spectrometry (GC–MS). Quality parameter analyses demonstrated that high-N fertilizer application led to a significant increase in grain protein content and improvement in starch and bread-making quality. Comparative metabolomic profiling of six grain developmental stages resulted in identification of 74 metabolites, including amino acids, carbohydrates, organic acids and lipids/alcohol, which are primarily involved in carbon and N metabolism. Under high-N fertilizer treatment, numerous metabolites accumulated significantly during grain development. Principal component analysis revealed two principal components as being responsible for the variances resulting from N-fertilizer treatments. Metabolite–metabolite correlation analysis demonstrated that the high-N treatment group had a greater number of positive correlations among metabolites, suggesting that high-N fertilizer treatment induced a concerted metabolic change that resulted in improved grain development. Particularly, the high-N treatment-mediated significant accumulation of metabolites involved in the TCA cycle, starch and storage protein synthesis could be responsible for the improvement of grain yield and quality. Our results provide new insight into the molecular mechanisms of wheat grain development and yield and quality.     

三大检索系统收录我校论文的现状分析

统计分析了三大著名检索系统收录山东农业大学论文的基本特点，提出了存在的问题和发展的建议。     

综合治理前后和田河流域生态环境状况变化及原因探讨

干旱区内陆河流域生态环境的变化关系到人类的生存和社会的发展。针对和田河流域在综合治理前后生态环境变化的问题,以1990年、2000年、2010年7—8月份三期的Landsat-TM和中巴资源卫星遥感数据为依据,借助转移矩阵和生态环境状况指数的方法,对比分析了综合治理前后林草地面积及生态环境状况的变化,得到如下结论:(1)综合治理后,天然林草地面积减少幅度加大,人工林地面积快速增加;(2)1990—2000年和2000—2010年,生态环境状况指数下降幅度分别为0.1%和1.19%;(3)耕地大面积的扩张是天然林草地面积减少和生态环境状况变差的根本原因。     

1978—2008年EI收录广东省论文统计分析

EI论文是衡量地区科技实力的重要参数之一。对1978—2008年间EI收录的广东省论文进行统计分析,从年度、地区、作者、机构和语种、文献类型方面描述论文分布特征,揭示改革开放30年来广东省的科研成果和科技进步。     

国际三大检索系统收录分析与投稿指南

介绍了SCI、EI、ISTP国际三大检索系统和其收录文献的特点，指出写好英文摘要、参考文献等对收录的重要性．以及三大检索系统收录文献的投稿要求。     

Screening of allelochemicals on barnyardgrass (Echinochloa crus-galli) and identification of potentially allelopathic compounds from rice (Oryza sativa) variety hull extracts

Experiments were conducted to screen 23 known allelochemicals, including sinapic acid, and an equimolar mixture of the chemicals for potential allelopathy on barnyardgrass (Echinochloa crus-galli var. oryzicola), and to identify allelochemical(s) from hull extracts from three rice (Oryza sativa L.) cultivars. In a bioassay, the inhibitory effect was increased as the concentration of allelochemicals increased from 10⁻⁵ to 10⁻³ M. Ferulic, p-hydroxybenzoic, p-coumaric, and m-coumaric acids were the most active compounds and caused the greatest effect on seed germination, germination rate, and total seedling dry weight reduction. p-hydroxybenzoic acid (10⁻³ M; pH 4.1) showed the greatest inhibitory effect on the same parameters. HPLC analysis using three rice cultivars, Janganbyeo, Baekambyeo, and Labelle, showed that the concentration and composition of potentially allelopathic compounds depended upon the cultivar. Hull extracts from the allelopathic cultivar Janganbyeo contained higher levels of p-hydroxybenzoic acid than did those of the non-allelopathic cultivars Labelle and Baekambyeo. Nine compounds, including p-hydroxybenzoic acid (4.29 mg/g) in Janganbyeo, seven compounds including m-coumaric (0.43 mg/g) in Labelle, and five compounds including p-hydroxybenzoic acid (0.36 mg/g) in Baekambyeo, were detected. Preliminary identification by HPLC analysis resulted in peaks with retention times near those of standards, including p-hydroxybenzoic acid that was confirmed with EI/MS. It is suggested that these compounds may be, at least, a key factor in rice allelopathy on barnyardgrass, and the information presented may contribute to the development of naturally occurring herbicides.