Identification of Plant Resistance Gene with Random Forest

为了解决传统基于同源序列比对的抗性基因识别方法中假阳性高、无法发现新的抗性基因的问题,提出了一种利用随机森林分类器和k-MEAnS聚类降采样方法的抗性基因识别算法。针对目前研究工作中挖掘盲目性大的问题,进行两点改进:引入了随机森林分类器和188维组合特征来进行抗性基因识别,这种基于样本统计学习的方法能够有效地捕捉抗性基因内在特性;对于训练过程中存在的严重类别不平衡现象,使用基于聚类的降采样方法得到了更具代表性的训练集,进一步降低了识别误差。实验结果表明,该算法可以有效地进行抗性基因的识别工作,能够对现有实验验证数据进行准确的分类,并在反例集上也获得了较高的精度。The traditional homology sequence alignment based approaches usually have high false positive rate and consequently new resistance genes are difficult to be identified.This paper presents a resistance gene identification approach by applying random forest classifier and K-Means under-sampling method.In order to solve the aimless problem in gene-mining research,two main contributions are provided.Firstly,it introduces random forest and 188 dimension features to identify resistance genes,accordingly the sample statistic learning approach can efficiently capture the internal characteristic of resistance genes.Secondly,it selects a more representative training subset and reduces the identification errors for solving the serious imbalanced classification during the training process.The experimental results indicate that the approach can efficiently identify the resistance genes,not only precisely clas-sifying the existing experimental verified data,but also obtaining high accuracy on the negative sample dataset.国家自然科学基金(60932008;61172098;60871092;61001013);中央高校基本科研业务费专项资金(HIT.ICRST.2010022);高等学校博士学科点专项科研基金(201003446)---

Effect of Flue-gas Cleaning Devices on Mercury Emission From Coal-fired Boiler

为研究燃煤锅炉烟气净化设施对汞排放特性的影响,采用Ontario-Hydro方法,对设有催化脱硝、静电除尘、海水脱硫的300MW燃煤锅炉排放烟气中汞的含量与形态进行分析,同时测定锅炉的煤、底渣、飞灰等固体样品以及脱硫塔前后、曝气之后海水样品中的汞含量。实验结果为:烟气中的气态汞占总汞的79.1%以上,脱硝催化剂对汞的价态具有强烈的转化作用,烟气中83.4%的气态Hg0被氧化成气态Hg2+;静电除尘对颗粒态汞的去除率几乎达到100%;在脱硫塔中,海水对烟气中汞的洗脱率高达73.6%,曝气后排放前的海水中含汞量是新鲜海水的5.5倍。研究表明锅炉烟气净化设施对汞的排放特性有着重要的影响。In order to study the effect of flue-gas cleaning devices on mercury emission from coal-fired boiler, Ontario-Hydro method had been applied to determine the mercury concentration and speciation in the flue-gas emitted from a 300MW coal-fired boiler, which was equipped with various pollution control devices, including selective catalyst reduction (SCR) De-NOx system, electrostatic precipitator (ESP), and flue-gas seawater De-SO2 system (FGD). Mercury concentration in raw coal, bottom ash and fly ash of the boiler, seawater at the inlet and outlet of SO2 absorption reactor and the drainage of aeration sink, were also analyzed. The results indicate that the percentage of gaseous mercury in total mercury discharged is more than 79.1%. De-NOx catalyst strongly affects the mercury speciation transformation, showing a conversion rate of 83.4% for Hg0 to Hg2+. The removal efficiency of particulate mercury by ESP is close to 100%. With seawater FGD, the removal efficiency of mercury is as high as 73.6%. The mercury concentration in the seawater of drainage from aeration sink is 5.5 times higher than that in fresh seawater. The study shows that the flue-gas cleaning devices in coal-fired power plant play an important role on mercury emission characterization

基于BP神经网络模型的新疆建设用地分析

鉴于BP神经网络在非线性领域预测中的应用,以新疆建设用地为研究对象,构建BP神经网络预测模型,选取1996～2006年总人口、城市化水平、GDP等10个因子,反映新疆人口状况、经济发展水平、产业结构及投资水平作为网络的仿真输入,对2007年新疆建设用地进行模拟预测,预测结果与实际面积的相对误差仅为0.06%.最后针对新疆建设用地中存在的问题,提出了保障经济与社会协调可持续发展的土地利用策略

1990年以来新疆生产建设兵团团场区域开发空间分异性研究

1990年以来新疆生产建设兵团155个团场区域开发的空间分异性分析表明:兵团团场区域开发整体水平提升,不同地域间团场发展态势也表现出鲜明的空间分异性。天山北坡团场具备整体的区域提升优势,塔河流域团场集聚增长较快,各独立片区集聚增长性相对较弱。团场区域发展的空间分异特征具有突出的区位指向性。在此基础上提出兵团区域开发的"两带、五区"的空间组织和发展战略思路

天山北坡经济带产业聚集与空间结构研究

产业聚集是区域经济发展中的必然过程和显著特点,产业空间结构则是在其过程中所形成的地域布局格局。天山北坡经济带作为重点经济开发区域,由于其自然条件与资源禀赋、区位交通与地缘优势、区域发展战略与产业布局、产业结构与产业分工调整等主要因素作用,发生了较为明显的产业聚集现象,演化发展成"一轴四区"的产业空间结构,产业地域分工明确。本文通过分析,提出了天山北坡经济带产业发展与调整的战略目标、思路和方向,以及产业聚集与城镇化发展、资源开发和绿洲生态环境相关问题的思考

Text mining in bioinformatics

从两个角度讨论应用于生物信息学中的文本挖掘方法。以搜索生物知识为目标,利用文本挖掘方法进行文献检索,进而构建相关数据库,如在PubMEd中挖掘蛋白质相互作用和基因疾病关系等知识。总结了可以应用文本挖掘技术的生物信息学问题,如蛋白质结构与功能的分析。探讨了文本挖掘研究者可以探索的生物信息学领域,以便更多的文本挖掘研究者可以将相关成果应用于生物信息学的研究中。Text mining methods in bioinformatics are discussed from two views.First,three problems are reviewed including searching biology knowledge,retrieving the reference by text mining method and reconstructing databases.For example,protein-protein interaction and gene-disease relationship can be mined from PubMed.Then the bioinformatics applications of text mining are concluded,such as protein structure and function prediction.At last,more methods and applications are discussed for helping text mining researchers to do more contribution in bioinformatics.国家自然科学基金项目(61001013、60932008、61001143

Nutrition state of culture water body and analyzation of its self -purification ability

本文根据 1 997年 2～ 1 2月间对对虾养殖水体的监测结果 ,应用营养指数法进行养殖水体的营养水平评价 ,结合自养指数对水体的自净能力进行分析。结果表明 ,养殖水体内具有较高的DIP和COD是造成水体富营养化的主要因素。较高的Chl a含量则是富营养化水体的表现。养殖池内水质状况同养殖周期和季节变更密切相关。养殖水体浮游植物和微生物的代谢偶联 ,是反映水体自净能力 ,保持水体稳定的基础。In this paper, the nutrient level of culture water body is elaborated according to nutritional index, and its self purification ability is analyzed in the light of autotrophic index,on the basis of monitoring result of prawn water during 1997.2～1997.12. The result shows that high DIP and COD are the main factors leading to eutrophication ,feature of which is high concentration of Chl a . The quality of the water has closer connection with the culture cycle and change of seasons.Metabolism coupling of phytoplankton and microorganism is the basis of indicating culture water's self purification ability and keeping it stable.福建省自然科学基金资助项目!(970 0 8号

影响‘尤力克’柠檬不定芽发生主要因素的研究

以无菌培养的‘尤力克’柠檬(Citrus limon L.)Burm ‘Eureka’实生苗为材料，探讨影响不定芽发生的主要因素