乌鲁木齐市空气环境质量变化趋势及污染防治办法     

董兰芳  魏艳敏  李维青 《新疆农业科学》2010,47(4):796-802

[目的]通过对乌鲁木齐市二氧化硫(SO2)、二氧化氮(NO2)、可吸入颗粒物、降尘的连续监测,分析了1996～2005年间空气环境质量中各污染物的变化趋势.[方法]通过实地监测,采样,对所采样品采用甲醛-盐酸副玫瑰苯胺光度法、Saltzman法进行实验分析.[结果]在此期间,乌鲁木齐市的主要污染物为SO2和可吸入颗粒物,其中SO2的年均值在0.068～0.145 mg/m3,可吸入颗粒物的年均值在0.115～0.186 mg/m3.SO2和可吸入颗粒物都超过国家<环境空气质量标准>二级标准,但总体上呈现下降趋势.从污染指数来看,1996年的主要污染物为降尘,1999、2003、2004、2005年主要污染物为SO2,其余年份均为可吸入颗粒物.[结论]从2005年空气污染状况分析出乌鲁木齐市空气污染具有明显的季节差异,在此基础上,从能源、工业布局、法律保障三方面提出相应的治理措施,用以减轻乌鲁木齐是空气污染程度.  相似文献   

六角弹簧管汽车碰撞吸能装置的效能研究     

孟志强  何涛  尹望吾  江和平  陈颖 《湖南农业大学学报(自然科学版)》2011,38(11):43-46

根据六角弹簧管汽车碰撞吸能装置的结构与工作原理,采用SolidWorks,Hypermesh和LS-DYNA仿真软件,建立吸能装置的有限元分析模型应用所建立的有限元模型,分析了当配重块质量为1.5 t,时速为50 km/h,汽车正面碰撞时吸能装置的效能仿真结果表明,六角弹簧管汽车碰撞吸能装置具有很好的保护效果,汽车纵梁侵入量小（252.9 mm）、碰撞能量的吸收比高（52.09%）、汽车X方向加速度峰值低（58.8 g）,验证了该吸能装置能有效地保护汽车和车内乘员的安全  相似文献   

基于改进占空比扰动法的光伏系统的研究     

刘珊  易灵芝  邓栋  罗晓雪 《湖南农业大学学报(自然科学版)》2011,38(3):29-32

针对车辆轮荷的显著差异会降低车辆的平顺性和驱动能力这一问题,提出了一种油气耦连悬架系统.首先介绍了该系统的结构和原理,并在Matlab/Simulink下搭建了其动力学模型,最后将该模型与车辆动力学仿真软件Carsim进行联合仿真,在不平路面下对是否装有该耦连悬架系统车辆的侧倾角、不足转向度、发动机输出功率等指标进行仿真对比,研究该耦连悬架系统对车辆平顺性和操纵稳定性的影响.仿真结果表明,油气耦连悬架系统可以增加车辆的通过性和驱动能力,提高车辆的平顺性.  相似文献   

日光温室蔬菜生产控湿防病技术     

宜荣莉 《河北农业》2011,(2):32-32

日光温室蔬菜生产由于周年利用,复种指数高,并以塑料薄膜为覆盖材料,密封性强,严寒季节为了保温蓄热,通常通风量小,通风时间短,有时甚至需要完全密闭.使棚室内空气湿度大,有时茎叶表面还会形成水膜或露珠,为病菌侵染和病害蔓延提供了条件.造成日光温室蔬菜病害发生种类多、危害重,用药频繁,污染严重.因此,控制湿度对控制病害、减少...  相似文献   

Ambrosia Artemisfifolia L. Invasive and Allergic Weed Species on the Territory of Novi Sad     

B. Konstantinovie  ;M. Meseldzija  ;Bo. Konstantinovie  ;N. Mandie 《农业科学与技术》2011,(3):304-309

During three years lasting studies on the territory of the city of Novi Sad, terrain studies of Ambrosia artemisiifolia L. distribution as well as mapping were performed on regulated and disordered green areas and on arable areas. For mapping of ragweed distribution, partially modified method of Braun-Blanquet was used, and data processing was perfomed by specially designed program Ambrosia Spot Marker. Monitoring of this species was also done because of the occurrence of retrovegetation after mowing. During vegetation period, this allergenic weed species was controlled by multiple mowing, and rough ruderal sites outside settlements were treated by glyphosate at a rate of 1.2 kg ha^-1 -2.4 kg ha^-1. The study comprehended also monitoring of pollen concentrations in the air by Rotorod pollen sampler spore collector. A. artemisiifolia L. was established in 21 city zones on over 200 localities, on the banks of the river Danube, in Petrovaradin and Sremski Karlovci. Recommended mechanical measures such as mowing, drilling in the phase of germination, and chemical control measures, resulted in significant reduction ofA. artemisiifolia L. In the second half of the August 2009 the highest number of pollen grains was found in the amount of 783 pollen grains per m3 of air.  相似文献   

小桐子幼苗在空气干旱胁迫下的水份状况变化与渗透调节物质响应差异（摘要）     

陈凯  龚明 《农业科学与技术》2011,(3):343-346

[目的]研究小桐子幼苗在空气干旱胁迫下的水分状况变化与渗透调节物质响应差异,以更好地理解其抗旱性机制。[方法]以培养12d的小桐子幼苗为材料,在25℃/20℃（昼/夜）、16h光照、相对湿度75%的人工气候箱中进行空气干旱处理,测定小桐子水势、渗透势,以及可溶性糖、脯氨酸、甜菜碱含量变化。[结果]空气干旱处理导致小桐子叶片水势、渗透势显著下降,膨压丧失。小桐子叶片和茎秆中可溶性糖、脯氨酸和甜菜碱含量不同程度地显著上升。[结论]小桐子叶和茎中有机渗透调节物质对干旱胁迫的响应存在明显差异,总体而言,叶片对干旱的响应大于茎秆。  相似文献   

Survey on Gamasyab River Water Quality in Nahavand Township,Iran     

M. Reyahi Khoram  M. Nafea 《农业科学与技术》2011,(4):495-501

Gamasyab River, which is the biggest river of Hamadan Province, is sourced from Karstic Springs in Nahavand Township Southern Mountainous Region and supplies a major part of water needs of the region. In this research seasonal variation of water quality and also the degree of pollution related to Gamasyab River water have been assessed. First the general status of the river was studied and four sampling stations were determined. In this research, the quality of river water including Dissolved Oxygen （DO）, five days Biochemical Oxygen Demand （BOD）5, Chemical Oxygen Demand （COD）, Nitrate, phosphate, temperature, Total Hardness（TH）, Total Suspended Solid （TSS）, Total Dissolved Solid （TDS） and PH have been determined and assessed on a monthly basis within a five years period. The results were reported as seasonally and presented using statistical tables and graphs. These results showed that Nitrate concentration in Gamasyab River is strongly depending on distance from Gamasyab spring. By increasing the distance from Gamasyab spring, nitrate concentration increased. The amount of DO in the river water is stable in each station within the year. Air temperature changes have had no effect in the amount of DO. Therefore, it is recommended that the river pollution control plans be implemented more serious than before, non point source pollution related to agricultural activities be managed and prevent from pouring untreated rural wastewaters to the mentioned river.  相似文献   

荠菜主要病虫害防治     

何永梅 《农药市场信息》2010,(3)

<正>1.霜霉病发病初期,叶面上呈浅绿色病斑,后为黄色、浅褐色,背面生暗绿色的霉层。病株叶片僵化,严重时枯黄脱落。该病由十字花科霜霉菌侵染所致。平均气温16℃,空气相对湿度在80%~90%时,有利于病菌  相似文献   

保护中国红豆杉之措施     

刘声喜 《安徽林业科技》2010,(Z1):78-78

红豆杉是第四纪冰川遗留下来的古老树种,在地球上已有250万年的历史,是世界上公认的濒临绝灭的天然珍稀植物,也是我国一级保护植物,有"树木活化石"和"植物界的大熊猫"之称。红豆杉全身是宝。它的木材是优质红木,属珍稀名贵树木;它的提取物紫杉醇是国际公认的治癌良药;它全天24小时不停吸入二氧化碳,呼出氧气,还可以吸收一氧化碳、尼古丁、甲醛、二甲苯等有毒物质,是名副其实的"空气净化器"。  相似文献   

低温天气猪流感的防治   总被引：1，自引：0，他引：1  

张是  侍刚 《当代畜禽养殖业》2010,(9)

<正>猪流感是猪的一种急性、热性、高度接触性传染病,主要通过空气传播,各种日龄猪只均可发生,多发于冬春寒冷与天气突变季节。本病能引起种猪繁殖障碍、育肥猪增重减慢等,也是猪产生免疫抑制的主要诱因,并且继发细菌感染。  相似文献