畜禽舍末端水喷淋废气处理系统的颗粒物净化性能分析与优化

【目的】畜禽养殖舍排出的大量颗粒物及吸附的臭气成分和微生物会对大气环境和周边人员的健康造成严重破坏,降低废气中颗粒物浓度是畜禽舍末端废气净化技术的核心目标之一。【方法】针对畜禽养殖末端卧式水喷淋净化技术,通过自主搭建的卧式水喷淋系统颗粒物净化效率试验平台,设计正交试验方案,采用极差分析和方差分析方法,研究通风风速、喷嘴压力、喷嘴额定孔径及喷嘴雾化角度等关键调控参数对颗粒物(PM2.5和PM10)净化效率的影响规律,并运用参数优化模型获得针对不同粒径颗粒物的最优调控参数组合。【结果】研究结果表明,影响PM2.5净化效果的主次顺序为喷嘴压力>通风风速>喷嘴额定孔径>喷嘴雾化角度;影响PM10净化效果的主次顺序为喷嘴压力>喷嘴额定孔径>喷嘴雾化角度>通风风速。通过优化求解,最优参数组合为通风风速为1.5 m/s、喷嘴压力为60 kPa、喷嘴额定孔径为11.1 mm、喷嘴雾化角度为120°。验证试验结果表明,最优参数组合的PM10净化效率为40.4%,PM2.5净化效率为41.1%。【结论】研究结果可以为畜禽舍末端废气处理系统颗粒物净化设备的设计和运行参数调...     

Distribution and Identification of Ixodid Tick Species on Livestock in Northern Pakistan

Identification of lxodid tick species on livestock in two districts, viz., D.I. Khan and Lakki Marwat of Northern Pakistan were made during the period from March to November 2009 through animals＇ survey and questionnaire. The main tick species were Amblyomma （14.3%）, Boophilus microplus （l 8.5%） and Hyalomma anatolicum and H. dromedarii （67.2%）. Out of 3009 collected ticks, the highest number of female （88.7%） and the lowest of males （ l 1.3%） belong to Boophilus; the lowest number of female （92.4%） and the highest of males （77.5%） belong to Amblyomma. However, cows were more susceptible than buffaloes and camels ranked third to ticks infestation. Moreover, cows, buffalos, goats and sheep harbored mixed infestation （had more than one type of ticks）, however, camels and donkey harbored single infestation （had only one type of tick）. An emerging ethno-veterinary or traditional remedy is poultry keeping for ticks＇ elimination in Lakki Marwat. The results of this research will be helped in taking appropriate measures to reduce tick infestation and to improve management practices. Hence, it will help to increase farm productivity and farmers income.     

基于灰色综合关联度的廊坊市商品房平均售价及影响因素实证研究

对近年来河北省及其典型地市商品房平均售价进行定性对比分析.在此基础上,借助灰色综合关联度技术,以该指标连续多年位居河北省前列的廊坊市为例进行实证分析,并对其商品房平均售价及影响因素的相互关系进行探讨,对影响程度重大的地区经济发展和城镇居民可支配收入等因素,提出今后进一步发展的意见和建议;同时对商品房平均售价的未来发展趋势进行预测.这对于促进廊防市市商品房平均售价稳健增长、进而带动河北省房地产业繁荣发展具有重要的现实指导意义;同时,对于填补相关领域内研究空白、实证分证分析方法的完善,具有重要的理论意义.     

不同降温时间与肉仔鸡生产性能的研究

本试验利用600只星布罗肉用仔鸡,在自行设计的控温设备中,观察了设计高温30℃下,不同降温时间(降温到25℃)对29—60日龄肉用仔鸡的生产性能,屠宰成绩和血液生理指标的影响。试验结果表明:降温能极显著地改进肉用仔鸡的平均体增重(P<0.01)公鸡好于母鸡,并且降温6小时能达到同12小时降温一样的效果。饲料转化率在不同温度处理间没有出现差异。这证明高温对生长快的鸡影响较大。降温促进鸡增重的效果,不仅与刺激采食量有关,而且与调节生理活动有关。在不同温度处理间,半净膛率,全净膛率,胸肌率和腹脂率没有显著差异。血红蛋白含量和红细胞数在不同温度处理间没有出现差异。红细胞压积在不同温度处理间有显著差异(P<0.05),降温12小时组的鸡显著大于恒温组的鸡,上述两组又显著大于降温6小时组。     

Study of the Disaster Prevention in the Process of the Traditional Dwelling Formation Through the Hakka''s Dwelling in Meizhou

Disaster prevention is the main reason of building origin and its direct developing motivation.The hakka's ancestor migrated from the Yellow River drainage basin for escaping the wars and built the dwellings with the style of homeland building,which comes to the first formation of the traditional architecture.Through the understanding the nature disasters and the results of disaster prevention,the hakka changed the plan and body of the building.The traditional dwellings in their matured stage improve their life-span by application of the disasters prevention measures.     

THE TIMES TRANSFORMATION OF DWELLING

It's a historical inexorable trend that the development of architecture is synchronistic with the social economic and science and technology.Dwelling also faces new transformation with the passage of times.This paper makes a systematic analysis in theory,method and conception.It includes four parts,they arc cataclysm of living requirement,al-ter of general conception,the renewal of composition method,and the exploration of new style.     

The Purchasers'' Risks and Its Precautions in the Pre-Selling of Commercial Houses

With the development of innovation in economic system,the real estate business became more and more active in recent years.In order to fit the innovation in housing system,the commercial housing pre-selling emerged,as the times require.Because the commercial housing pre-selling is still in the first phase in China,and the legal relations of the business are comparatively complicated,the legislation is not perfect correspondingly.So there are some new problems in the pre-selling of commercial houses.Hence the purchasers' risks and the precautions in the pre-selling of commercial houses are discussed in this paper.     

农村宅基地使用权权能及流转问题研究

具体分析了目前宅基地使用权转让中的问题,进而得出农村宅基地使用权应自由转让的结论。