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寒冷地区奶牛舍建筑形式对牛舍热环境舒适性的影响效果

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中国农业大学学报 2024年第8期29卷 169-178页

作者：王琦刘运颖杜欣怡赵婉莹王朝元施正香中国农业大学水利与土木工程学院北京100083 农业农村部设施农业工程重点实验室北京100083 北京市畜禽健康养殖环境工程技术研究中心北京100083 中国农村技术开发中心北京100045

针对目前我国奶牛舍在寒冷地区应用时保温隔热性能不足的问题,采用建筑热工评价和奶牛热应激评估相结合的方法,对寒冷地区开放式和密闭有窗式2种牛舍的围护结构热阻进行测算,对牛舍内夏季的热环境参数进行测试并采用温湿指数和奶牛皮肤... 详细信息

针对目前我国奶牛舍在寒冷地区应用时保温隔热性能不足的问题,采用建筑热工评价和奶牛热应激评估相结合的方法,对寒冷地区开放式和密闭有窗式2种牛舍的围护结构热阻进行测算,对牛舍内夏季的热环境参数进行测试并采用温湿指数和奶牛皮肤温度指数对奶牛的热应激程度进行评估,基于已有研究对牛舍内冬季的热环境进行理论预测,对寒冷地区应用不同建筑形式的奶牛舍的舍内热环境舒适性效果进行研究。结果表明:(1)开放式和密闭有窗式牛舍的屋面热阻值基本满足要求,但侧墙热阻值均显著低于该地区要求的墙体低限热阻值;(2)在夏季,2种建筑形式的牛舍在寒冷地区均可提供较舒适的舍内热环境,舍内奶牛热应激问题不显著;(3)冬季应用时舍内温度均无法满足要求。开放式牛舍应用于我国寒冷地区时无法提供适宜的舍内热环境,建议采用密闭有窗式牛舍,要求其墙体热阻值≥1.137 m^(2)·K/W,屋面热阻值≥1.459 m^(2)·K/W。

关键词：建筑形式热环境环境舒适性牛舍

AMicroseismic Signal Denoising Algorithm Combining VMD and Wavelet Threshold Denoising Optimized by BWOA

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Computer Modeling in Engineering & Sciences 2024年第10期141卷 187-217页

作者： Dijun Rao Min Huang Xiuzhi shi Zhi Yu zhengxiang He Zijin Mining Group Co. Ltd.Xiamen361016China Zijin(Changsha)Engineering Technology Co. Ltd.Changsha410006China State Key Laboratory of Comprehensive Utilization of Low-Grade Refractory Gold Ores Shanghang364204China School of Resources and Safety Engineering Central South UniversityChangsha410083China School of Resources&Environment Engineering Jiangxi University of Science and TechnologyGanzhou341000China Zijin School of Geology and Mining Fuzhou UniversityFuzhou350116China State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources China University of Mining and TechnologyXuzhou221116China

The denoising of microseismic signals is a prerequisite for subsequent analysis and *** this research,a new microseismic signal denoising algorithm called the Black Widow Optimization Algorithm(BWOA)optimized VariationalMode Decomposition(VMD)jointWavelet Threshold Denoising(WTD)algorithm(BVW)is *** BVW algorithm integrates VMD and WTD,both of which are optimized by ***,this algorithm utilizes VMD to decompose the microseismic signal to be denoised into several Band-Limited IntrinsicMode Functions(BLIMFs).Subsequently,these BLIMFs whose correlation coefficients with the microseismic signal to be denoised are higher than a threshold are selected as the effective mode functions,and the effective mode functions are denoised using WTD to filter out the residual low-and intermediate-frequency ***,the denoised microseismic signal is obtained through *** ideal values of VMD parameters and WTD parameters are acquired by searching with BWOA to achieve the best VMD decomposition performance and solve the problem of relying on experience and requiring a large workload in the application of the WTD *** outcomes of simulated experiments indicate that this algorithm is capable of achieving good denoising performance under noise of different intensities,and the denoising performance is significantly better than the commonly used VMD and Empirical Mode Decomposition(EMD)*** BVW algorithm is more efficient in filtering noise,the waveform after denoising is smoother,the amplitude of the waveform is the closest to the original signal,and the signal-to-noise ratio(SNR)and the root mean square error after denoising are more *** case based on Fankou Lead-Zinc Mine shows that for microseismic signals with different intensities of noise monitored on-site,compared with VMD and EMD,the BVW algorithm ismore efficient in filtering noise,and the SNR after denoising is higher.

关键词： Variational mode decomposition microseismic signal denoising wavelet threshold denoising black widow optimization algorithm

Gases emissions estimation and analysis by using carbon dioxide balance method in natural-ventilated dairy cow barns

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International Journal of Agricultural and Biological Engineering 2020年第2期13卷 41-47页

作者： Bing Zou zhengxiang shi Songhuai Du College of Information and Electrical Engineering China Agricultural UniversityBeijing 100083China College of Water Sources and Civil Engineering China Agricultural UniversityBeijing 100083China

Contaminated gases emissions from livestock industry are becoming one of the most significant contributors to the increasingly serious environmental *** find a way to reduce gases emissions,it is essential to reveal the factors that can affect the gases *** this study,the concentrations of typical gases(including ammonia(NH_(3)),carbon dioxide(CO_(2)),hydrogen sulfide(H_(2)S),and sulfur dioxide(SO_(2)))generated from naturally-ventilated dairy cow barns were detected through the sample-data method in Tianjin,northern *** environmental conditions,such as temperature(T)and relative humidity(RH),were measured *** applying the carbon dioxide mass balance method,ammonia,hydrogen sulfide and sulfur dioxide emissions were *** correlation analysis and regression analysis between the climate condition and gas emissions were conducted to assess the data collected in dairy cow barns during the whole study *** was a significant relationship between environmental conditions and gas ***3,H2S and SO_(2) emissions from the building are in the range of 0.98-2.36 g/LU·h,0-0.034 g/LU·h,and 0-0.069 g/LU·h,*** numerical analysis shows that the NH3 emission is highly correlated with the temperature and relative *** ventilation rate shows a positive correlation with all the three gases.

关键词： gas emissions environmental conditions correlation analysis regression analysis carbon dioxide H2S emission NH3 emission SO_(2)emission

Effects of inductive methods on dunging behavior of weaning pigs in slatted floor pens

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International Journal of Agricultural and Biological Engineering 2016年第4期9卷 192-198页

作者： Wang Yu Li Dapeng Shen Xiong shi zhengxiang Key Laboratory of Agricultural Engineering in Structure and Environment Ministry of AgricultureBeijing 100083China College of Water Resources and Civil Engineering China Agricultural UniversityBeijing 100083China Tianjin Key Laboratory of Indoor Air Environmental Quality Control School of Environmental Science and EngineeringTianjin UniversityTianjin 300072China

The excreta of pig is generally utilized to induce pigs to excrete in particular area,which reduces the subsequent work required to clean *** paper discussed a new induction device design based on the biological characteristics of *** different induction materials in the devices,the frequency and location of the excretory behavior of pigs through five treatments and a control group were *** to the results,different induction methods had significant(p<0.05)effects on frequency and duration of excretory *** to the conventional induction method,the induction devices were significantly(p<0.05)more effective in training pigs to excrete in the assigned area,the most effective material used in the induction devices was *** the inductive feces had been preserved in the air for a longer time,the effect of inducing excretory behavior would have been more *** devices did not work to induce pigs to excrete in the induction area.

关键词： animal behavior weaning pigs slatted floor pen pig training excretory behavior inductive material

Behavioral response of pregnant ewes to high ambient temperature in loose housing system

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International Journal of Agricultural and Biological Engineering 2008年第1期1卷 31-36页

作者： Geng Ailian Zang Qiang Chen Gang shi zhengxiang Li Baoming Key Laboratory of Agricultural Bioenvironmental Engineering Ministry of AgricultureCollege of Water Conservancy and Civil EngineeringChina Agricultural UniversityBeijing 100083China Institute of Animal Husbandry and Veterinary Medicine Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China

In order to investigate the behavioral responses of pregnant ewes to high ambient temperature in a loose housing system,eighty-seven pregnant ewes(Chinese little fat-tailed sheep,Ovis aries)from the same loose house were chosen,and nine ewes with the similar body weight and age were marked for later individual behavioral *** ambient temperature and relative humidity were recorded,and the individual behaviors of the pregnant ewes were observed continuously from 04:50 to 20:00 once every other day for 14 *** behavioral state of all the pregnant ewes was recorded once every hour from 5:00 to 20:00,the number of pregnant ewes selecting specific lying areas(designated as area A and area B),was recorded at 15 minute intervals from 12:00 to 17:00 *** final results show that the behavioral durations are significantly different in eating and drinking,rumination,rest,and locomotion for pregnant ewes(P<0.05).The time spent in lying for rumination or rest is significantly longer than that for locomotion(P<0.05).Temperature has a significant effect on the number of pregnant ewes lying on the floor(P<0.05).There are significant differences for pregnant ewes’preference of area A and area B for lying at temperatures ranging from 27.0℃to 31.0℃(P<0.05).The results indicate that the lying behavior is significantly more than the locomotion behavior for the pregnant ewes in the loose housing systems under the high ambient temperature.

关键词： pregnant ewes loose housing behavior high temperature

Effects of ripple cross angles and turbulence models on wet curtain resistance

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International Journal of Agricultural and Biological Engineering 2019年第4期12卷 43-46页

作者： Tao Ding Lumeng Fang zhengxiang shi Baoming Li Yang Zhao College of Water Resources and Civil Engineering China Agricultural UniversityBeijing 100083China Beijing Engineering Research Center for Safety and Energy-Saving Technology for Water Supply Network Systems Beijing 100083China Key Laboratory of Agricultural Engineering in Structure and Environment Beijing 100083China

To study the influence of ripple cross angles on the resistance of wet curtains,wet curtains with different ripple cross angles(45°/45°,45°/15°)were tested on agricultural ventilation equipment performance testing benches,and the static pressure drop under different wind speeds(1-3 m/s)was *** turbulence models(κ-ε,RNGκ-ε,κ-ω,SSTκ-ω)were adopted for numerical simulations of the two types of wet curtain,and the simulations’results were compared with those of *** average errors found are 41.1%,48.7%,27.1%,and 27.8%,respectively,and theκ-ωmodel is found to be the most suitable one for the calculation of wet curtain resistance among the four turbulence *** using theκ-ωturbulence model,the static pressure drop performances of wet curtains with ripple cross angles 45°/35°and 45°/25°were *** increases with wind speed and ripple cross angles,and a large ripple cross angle has a higher resistance growth rate with increasing wind speed.

关键词： wet curtain ripple cross angle resistance turbulence model ventilation cooling and humidifying system

Inactivation efficiency of slightly acidic electrolyzed water against microbes on facility surfaces in a disinfection channel

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International Journal of Agricultural and Biological Engineering 2017年第6期10卷 23-30页

作者： Zang Yitian Li Baoming shi zhengxiang Sheng Xiaowei Wu Hongxiang Shu Dengqun College of Animal Science and Technology Jiangxi Agricultural UniversityNanchang 330045China Key Laboratory of Structure and Environment in Agricultural Engineering Ministry of AgricultureChina Agricultural UniversityBeijing 100083China

Slightly acidic electrolyzed water(SAEW,pH 6.0-6.5)is an ideal and environmentally-friendly disinfectant,which was used to prevent and control bacterial infections on *** work aims to investigate the inactivation effectiveness of SAEW in inactivating microbes in a disinfection *** bactericidal efficiency of SAEW on equipment surfaces was compared to two commercial disinfectants,Kuei A bromide solution(KAS,5:1000 v/v)and Glutaraldehyde solution(GS,5:1000 v/v).The disinfection effectiveness of SAEW in inactivating Salmonella enteritidis(***)on equipment surfaces in the disinfection channel was evaluated,and a model was developed using multiple linear regression *** indicated that SAEW was significantly(p0.05).In addition,available chlorine concentration(ACC)was an important factor than other factors,and the inactivation efficiency of Salmonella enteritidis sprayed by SAEW treatment was different between iron materials,kits and clothing surfaces(iron>kit>clothing).

关键词： slightly acidic electrolyzed water disinfection channel S.enteritidis disinfection bacterial infection prevention and control livestock farm

Comparison of direct and indirect determinations of dynamic ventilation rate in a modern dairy free stall barn

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International Journal of Agricultural and Biological Engineering 2020年第6期13卷 41-46页

作者： Bing Zou Albert J.Heber zhengxiang shi Songhuai Du Yaomin Jin Teng Teeh Lim College of Information and Electrical Engineering China Agricultural UniversityBeijing 100083 China Department of Agriculture and Biological Engineering Purdue UniversityWest Lafayette 47907USA College of Water Sources and Civil Engineering China Agricultural UniversityBeijing 100083China Ministry of Energy Mines and Petroleum ResourcesVictoria V8W 9N3Canada College of Agriculture Food and Natural ResourcesUniversity of MissouriColumbia 65211USA

Reliable estimation of the ventilation rate(VR)in intensive livestock buildings is necessary for studying building environmental control strategies and predicting indoor air quality and air *** direct air exchange measurements are time-consuming and expensive,it is environmentally inefficient to measure livestock building VR continuously in ***,indirect VR estimation methods have been widely used in modelling environmental control and air emissions,and also to measure airflow in the *** accuracy of indirect measurement methods needs to be evaluated by comparing with direct *** this study,the direct and indirect methods of determining hourly and daily mean VRs were applied to a mechanically-ventilated dairy free stall barn monitored by the 24-month National Air Emissions Monitoring *** direct method was used to continuously monitor fan rotational speeds,and differential static pressures,coupled with periodic in-situ fan performance assessments,to calculate the *** indirect method consisted of estimating the VR using CO2 concentration measurements and the CO2 mass balance *** average daily and hourly means(mean±SD)of directly measured barn ventilation rates for two years were(246±73)m3/s and(245±77)m3/s,*** average daily and hourly means(mean±SD)of barn ventilation rates estimated by the CO2 mass balance method were(287±93.4)m3/s and(287±118)m3/s,*** analyses showed a strong correlation between the indirect CO2 mass balance method and direct measurement methods(r=0.93 for daily means and r=0.85 for hourly means).

关键词： dynamic ventilation rate modern dairy free stall barn carbon dioxide mass balance dairy cow direct and indirect determination comparison

Heat stress alleviation for dairy cows housed in an open-sided barn by cooling fan and perforated air ducting(PAD)system

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International Journal of Agricultural and Biological Engineering 2017年第6期10卷 1-10页

作者： Xie Lina Wang Chaoyuan Ding Luyu Gui Zhiyuan Zhang Lu shi zhengxiang Li Baoming Jia Chuntao Department of Agricultural Structure and Bioenvironmental Engineering College of Water Resources and Civil EngineeringChina Agricultural UniversityBeijing 100083China Key Laboratory of Agricultural Engineering in Structure and Environment Ministry of AgricultureChina Agricultural UniversityBeijing 100083China Engineering Research Center on Animal Healthy Environment Beijing 100083China Hailin Dairy Farm Shigezhuang TownTianjin 301718China

Curtain-sided barns with circulation fans above stall are commonly used to house dairy cows in *** farms equipped with circulation fans are unable to provide appropriate cooling,especially for the naturally ventilated shed,which can result in decreasing feed intake and milk *** alleviating heat stress and improving animal comfort,a system consisting of an air cooler and a 30 m perforated air duct(PAD)was integrated to evenly distribute cooling *** air was cooled by underground water and delivered to targeted zones above stall *** system was evaluated in an open sided dairy barn in Tianjin,*** the stalls equipped with PAD system,air velocity reached above 1.1 m/s at 0.5 m height plane of the stall space,and was more uniformly *** to the stalls equipped with circulation fans,the PAD system lowered air temperature by 1.5℃,and increased relative humidity by 8.1%.On average,Temperature Humidity Index(THI)and Equivalent Temperature Index(ETI)were decreased by 0.5 and 0.6,*** a 15 days’operation of the system,rectal temperatures of the treated dairy cows were significantly *** results also showed that the cows under PADs had a higher milk *** findings suggest the PAD can be an effective cooling alternative for naturally ventilated dairy barns to alleviate heat stress.

关键词： dairy cow heat stress perforated air duct cooling fan naturally-ventilated barn