TCD燃烧系统对柴油机燃烧和排放性能改善效果的试验研究

为探究道依茨TCD2015柴油机上配备的导流燃烧系统(简称TCD燃烧系统,T表示涡轮增压器,Turbocharger,C表示进气中冷,Charge air cooling,D为柴油颗粒捕集器,Diesel particle filter)对改善柴油机燃烧性能和降低污染物排放的效果,采用单缸机试验对TCD燃烧系统在不同转速、负荷和过量空气系数下的燃烧和排放性能进行研究。试验结果表明不同工况下TCD燃烧系统燃油消耗率和Soot排放量均低于传统ω燃烧系统,燃油消耗率最大降幅为7.01%,Soot排放量最大降幅为86.67%,且低过量空气系数(1.2～1.6)下TCD燃烧系统仍具有较好的性能。为揭示TCD燃烧系统改善油气混合促进燃烧的机理,采用AVL Fire软件建立了柴油机性能仿真模型。计算结果表明,TCD燃烧系统的环状凸起结构将燃油导向内外两室,从而促进了缸内燃油发展过程,燃油当量比大于4的浓混合气区域燃油质量比例相比ω燃烧系统降幅最大为9.75%,活塞下移时TCD燃烧系统内油束撞击浅盘侧壁形成撞壁射流扩大了燃油扩散面积,从而改善了缸内油气混合质量,燃油当量比小于1的均匀混合气区域燃油质量比例相比ω燃烧系统降幅最大为7.45%,因此TCD燃烧系统能够有效改善柴油机的燃烧和排放性能,可应用于柴油机高负荷和低过量空气系数工况综合性能提升。研究结果可为柴油机燃烧系统开发和改进提供参考。     

规模化猪舍废气复合净化系统设计与试验

为解决规模化猪舍废气排放造成的环境污染问题，设计了一种猪舍废气复合净化系统。该系统采用化学法与水洗法相结合，通过PLC（可编程逻辑控制器）控制系统实时采集净化系统内的pH值、电导率、液位和压差等动态环境数据，智能控制洗涤泵启停和电磁阀通断，自动完成供水、加酸、喷淋和排废4个工作环节。同时，控制系统采用MCGS触摸屏与PLC建立通讯，通过创建人机交互界面实现系统环境数据监测、运行状态流动显示、按需配置系统参数和报警信息输出等多种功能，实现了系统操作的人性化和过程的可视化。系统可根据实际应用中对净化效率和运行成本的要求，实现多种控制模式，均有效抑制了猪舍废气排放。试验结果表明，系统对主要污染成分氨气的平均去除率可达到85%，整体运行可靠、控制简单，经济成本量化清晰。该系统在江西某种猪场实施应用，成效显著，可为畜禽养殖环境废气净化处理的工程应用提供参考。     

降低反刍动物甲烷排放的研究进展

本文阐述了反刍动物瘤胃甲烷生成的生物学机制及影响反刍动物瘤胃甲烷生成的因素，并用产明了降低瘤胃甲烷产生的方法，最后对降低甲烷生成的前景作了展望。     

木材干燥导水系数和换水系数的研究

木材(板、方材)的导水系数和换水系数是反映木材干燥或存放过程中水分迁移的重要物性参数。然而,我国对木材导水系数和换水系数的研究和测定工作十分有限。木材干燥有关的理论计算中,常用原苏联的数据。由于这些数据本身可能存在的误差及用于我国树种的可靠程度难以估计,故使理论结果的实际运用受到限制。本文采用等厚试件系数分离法研究和测定了木材干燥过程动态导水系数和换水系数。     

水稻中系8541与中系8240光合特性的比较研究

本文通过光合作用参数的测定,详细的研究了中系8541和8240两种不同产量水平的水稻品种的光合特性.论述了在含等量叶绿素的条件下,中系8541和中系8240之间在对光谱的吸收、叶片的光合作用量子转化效率,叶绿体的PSⅡ(光系统Ⅱ)潜在活性(Fv/F_0)和原初光能转化效率(Fv/Fm等的主要区别.实验结果说明,上述各光合作用参数中系8541都优于中系8240.不仅如此.在Mg~(2+)作用下,Fv/Fo和Fv/Fm比值的提高以及Mg~(2+)对两个光系统激发能分配的调节能力中系8541也强于中系8240.     

Societal expectations of livestock farming in relation to environmental effects in Europe

The potential environmental effects of livestock farming are mainly associated with intensification of poultry, pig and dairy cow production systems. The major impacts are mainly caused by housing of livestock, which can lead to air and water pollution associated with nitrogen and phosphorus emissions and losses from manure. European countries regulate the potential for these types of pollution through a number of mechanisms, which have received wide public acceptance. In grazing systems, nitrogen pollution, associated with the use of nitrogen fertilizer, is also the subject of legislation. Perhaps because of this regulatory approach, surveys of the public have found that human food quality and animal welfare are more important issues than effects on air and water quality when considering livestock systems.Variation in stocking rates of grazing ruminants can change the structure and composition of pastures with potential impacts on biodiversity and the production of methane, a greenhouse gas. In European countries, maximum stocking rates have been set to reduce these impacts. Surveys of the European public have suggested that they are willing to pay for the mitigation of these environmental effects but that they also value strongly the cultural component of grazed livestock systems. There are few underlying concepts about how society views the environmental impacts of livestock systems. These are used to conclude that current attitudes are likely to prevail in the next decade.     

亚硫酸氢钠处理减轻低温对温州蜜柑光合作用的影响

 低温胁迫使温州蜜柑叶片的净光合速率(Pn)、光系统Ⅱ的光化学效率(Fv/Fm)及光合电子传递速率(ETR)下降，反映跨膜质子动力势的叶绿素毫秒延迟发光(ms-DIE)减弱，叶片中的ATP含量降低。低温胁迫前，用NaHSO₃ 5 mmol/L涂于叶片表面，可使处理植株叶片的Pn和Fv/Fm分别少下降了11.5%和11.6%，ETR和ATP含量几乎没有下降，ms-DLE的下降幅度减少。可见，在柑橘上施用NaHSO₃能够减轻短期低温对光合机构及光合作用的影响。     

Ranking cows’ methane emissions under commercial conditions with sniffers versus respiration chambers

This study assessed the ranking of dairy cows using individual-level correlations for methane (CH₄) emission on-farm using sniffers and in respiration chambers. In total 20 lactating dairy cows, ten Holstein and ten Jerseys were recorded using sniffers installed in milking robots for three weeks of lactation and subsequently in respiration chambers (RC) where they were each recorded on three occasions within the RC. Bivariate linear mixed models were used to determine the individual-level correlations (r_I) between sniffer and RC phenotypes as proxies for genetic correlations. Despite differences in feeding and management, the predicted CH₄ production from sniffers correlated highly with RC CH₄ production r_I?=?0.77?±?0.18 and CH₄ breath concentration correlated nearly as well with RC CH₄ production r_I?=?0.75?±?0.20. These correlations between sniffers on-farm and RC demonstrate the potential of sniffers measurements as large-scale indicator traits for CH₄ emissions in dairy cattle.     

新一代温室气体排放情景下安徽省未来气候变化预估分析

基于联合国政府间气候变化专门委员会(IPCC)发布的新一代排放情景,和中国气象局发布的"中国地区气候变化预估数据集V3.0",针对安徽省,笔者选择1971—2000年作为基准期,采用区域气候模式模拟的方法,对比分析安徽省未来气候变化特征,重点评估近期内即未来20年气候变化趋势。模拟结果显示,未来20年不同情景下安徽省平均气温均为上升,全省平均增温幅度约0.9~1.1℃;而降水量变化具有不同特征,较低排放情景下降水量以上升为主,高排放情景则以下降为主。到2050s全省平均气温相比于基准期将升高1.6~1.7℃,升温幅度呈现北高南低的特征;全省降水量相比于基准期将下降50~90 mm,各地降水量均呈下降趋势。另外,通过对降水和气温的模拟,预估未来该地区旱涝演替更加频繁,高温热浪等事件也将进一步频发。     

水分条件对巴音布鲁克高寒湿地CO_2排放的影响

在新疆天山中部巴音布鲁克天鹅湖高寒湿地,以苔草(Carex tristachya)为主要建群种的样地为研究对象,利用英国PP-systems公司生产的便携式土壤呼吸测定系统(CIRAS-2-SRC)研究了不同地表水分条件对天鹅湖高寒湿地夏季土壤CO2排放的影响。结果表明,1)湿润区的生物量大于干燥区;干燥区土壤CO2排放高于湿润区,干燥区土壤CO2排放日变化曲线为单峰曲线,CO2排放最高点出现在当地14:00-16:00,最高值为1.185 0g CO2·m-2·h-1;湿润区土壤CO2排放日变化曲线为双峰曲线,两个峰值分别出现在12:00和16:00,最高值为1.024 0g CO2·m-2·h-1。2)不同水分条件下生物量中凋落物含量影响土壤CO2排放。土壤温度是CO2排放的主要限制因子,且地表干燥区CO2排放与土壤温度的相关性更显著(P0.01)。土壤湿度与CO2排放相关性不显著(P湿润区=0.997,P干燥区=0.409)。