Residual behavior and risk assessment of butralin in peanut fields
作者：
Yang, Lihua;Song, Xiangxiang;Zhou, Xuguo;Zhou, Yuzhou;Zhou, Yaoyu* ;...
期刊：
Environmental Monitoring and Assessment ,2020年192(1):62 ISSN：0167-6369
通讯作者：
Zhou, Yaoyu;Gong, Daoxin
作者机构：
[Yang, Danxin; Deng, Yaocheng; Gong, Daoxin; Yang, Lihua; Zhou, Yuzhou; Zhou, Yaoyu; Song, Xiangxiang; Zhou, YY; Gong, DX; Chen, Ling] Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Hunan, Peoples R China.;[Luo, Haifeng] Hunan Agr Univ, Coll Engn, Changsha 410128, Hunan, Peoples R China.;[Zhou, Xuguo] Univ Kentucky, Dept Entomol, Lexington, KY 40546 USA.
通讯机构：
[Zhou, YY; Gong, DX] H;Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Hunan, Peoples R China.
关键词：
Butralin;Degradation;Half-life;Peanut;Residue;Risk assessment
摘要：
Butralin is widely used to control single-leaf weeds and some dicotyledons. The application of butralin in the environment may cause residue beyond regulation criteria and residual toxicity. Therefore, it is important to detect and supervise the dissipation behavior of butralin in edible raw food and in the environment. The aim of this study was to monitor butralin in peanuts and soil under farmland conditions and examine the likely dietary risk assessment of butralin for Chinese people on the basis of residual concentrations. A method for the analysis of butralin residue and its dissipation in peanut plants and soil under field conditions was investigated. The results show that an analytical method for the quantization of butralin in peanuts and soil utilizing gas chromatography with electron capture detection (GC-ECD) was developed. Standard recovery experiments using three different butralin spiking levels of 0.01, 0.1, and 1.0mgkg−1 in different samples (i.e., peanut kernels, shell, seedling, stalk, and soil) were conducted. The recoveries of butralin from all matrices ranged from 86 to 108% with relative standard deviations from 3 to 6% (n = 5). The limit of quantification (LOQ) of the method was 0.01mgkg−1. After storage at − 20°C for 365days, the degradation rate of residues of butralin in peanut kernels was less than 30%, which met the storage stability test criteria for pesticide residues in stored commodities of plant origin. The dissipation half-lives of butralin ranged from 4.2 to 6.6days and 4.6 to 6.6days in peanut seedlings and soil, respectively, in farmland ecosystems. At the normal harvest time, the final residue concentrations of butralin in peanuts and soil were all below the LOQ. The final total risk quotient (RQ) values were much lower than RQ = 100%, which indicated that the long-run fitness risk associated with butralin residue in different groups of registered crops is correspondingly low for people in China. The current research results could offer guidance for the rational use of butralin and provide data support for the building of maximum residue limits (MRLs) in China. © 2019, Springer Nature Switzerland AG.
语种：
英文
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Evapotranspiration estimation using a modified Priestley-Taylor model in a rice-wheat rotation system
作者：
Qiu, Rangjian;Liu, Chunwei;Cui, Ningbo* ;Wu, Youjie;Wang, Zhenchang;...
期刊：
Agricultural Water Management ,2019年224:105755 ISSN：0378-3774
通讯作者：
Cui, Ningbo
作者机构：
[Liu, Chunwei; Qiu, Rangjian] Nanjing Univ Informat Sci & Technol, Collaborat Innovat Ctr Forecast & Evaluat Meteoro, Sch Appl Meteorol, Jiangsu Key Lab Agr Meteorol, Nanjing 210044, Jiangsu, Peoples R China.;[Cui, Ningbo] Sichuan Univ, State Key Lab Hydraul & Mt River Engn, Chengdu 610065, Sichuan, Peoples R China.;[Cui, Ningbo] Sichuan Univ, Coll Water Resource & Hydropower, Chengdu 610065, Sichuan, Peoples R China.;[Wu, Youjie] Hunan Agr Univ, Coll Engn, Changsha 410128, Hunan, Peoples R China.;[Wang, Zhenchang] Hohai Univ, Coll Water Conservancy & Hydropower Engn, Nanjing 210098, Jiangsu, Peoples R China.
通讯机构：
[Cui, Ningbo] S;Sichuan Univ, State Key Lab Hydraul & Mt River Engn, Chengdu 610065, Sichuan, Peoples R China.;Sichuan Univ, Coll Water Resource & Hydropower, Chengdu 610065, Sichuan, Peoples R China.
关键词：
Bowen ratio energy balance;Evapotranspiration partitioning;Oryza sativa;Path analysis;Triticum aestivum
摘要：
The rice-wheat rotation system is one of the largest agricultural production systems worldwide. Accurate estimation of evapotranspiration (ET) in the rice-wheat rotation system is critical to enhance efficient irrigation management and water use. The variation of ET for a rice-wheat rotation system during 2015–2018 and its controlling meteorological factors was investigated using the Bowen ratio energy balance and path analysis methods. A modified Priestley–Taylor (PT) model considering soil water stress for soil evaporation (E) (fsw), and plant temperature constraint (deviation of air temperature from optimum for the crops used, ft), leaf senescence for transpiration was developed. The results showed that the diurnal variation of ET rate in different months exhibited a single peak curve with the maximum ET rates of 0.90 and 0.42 mm h−1 for rice and winter wheat, respectively. The total ET of the rice-wheat rotation system over the whole growing season was 765–841 mm, of which 63–67% was consumed by the rice field. The average daily ET rate over the whole growing season was 3.27–4.13 and 1.50-1.65 mm d−1 for rice and winter wheat, respectively. The results of ET partitioning showed that E accounted for 23–32% of the seasonal ET for rice and 48–51% for winter wheat. The ET partitioning of rice and winter wheat was closely linked to leaf area index (LAI). The ratio of E/ET reduced exponentially for rice with the increase of LAI, while it reduced linearly for winter wheat. The path analysis showed that the net radiation (Rn) was the dominant meteorological factor affecting short-term ET of the rice-wheat rotation system through the direct effect. The water vapour pressure deficit (VPD), another important factor influencing ET, showed mainly an indirect effect on ET through path of Rn and had a greater impact on ET for rice than that for wheat. The modified PT model could estimate ET for rice and winter wheat reasonably, with linear regression coefficient of 0.93–1.09 and coefficient of determination of 0.92−0.96. The model was sensitive to the fsw or ft. © 2019 Elsevier B.V.
语种：
英文
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Experimental and numerical investigation of the effects of low-pressure, high-pressure and internal EGR configurations on the performance, combustion and emission characteristics in a hydrogen-enriched heavy-duty lean-burn natural gas SI engine
作者：
Duan, Xiongbo;Liu, Yiqun;Liu, Jingping* ;Lai, Ming-Chia* ;Jansons, Marcis;...
期刊：
Energy Conversion and Management ,2019年195:1319-1333 ISSN：0196-8904
通讯作者：
Liu, Jingping;Lai, Ming-Chia
作者机构：
[Liu, Jingping; Zhang, Shiheng; Duan, Xiongbo] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Liu, Yiqun; Jansons, Marcis; Duan, Xiongbo; Lai, Ming-Chia] Wayne State Univ, Dept Mech Engn, Detroit, MI 48202 USA.;[Guo, Genmiao] Jiangsu Univ, Sch Energy & Power Engn, Zhenjiang 212013, Jiangsu, Peoples R China.;[Tang, Qijun] Hunan Agr Univ, Coll Engn, Changsha 410000, Hunan, Peoples R China.
通讯机构：
[Liu, Jingping] H;[Lai, Ming-Chia] W;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;Wayne State Univ, Dept Mech Engn, Detroit, MI 48202 USA.
关键词：
High-pressure EGR;Hydrogen-enriched natural gas engine;Internal EGR;Low-pressure EGR;Pressure wave
摘要：
In this study, a detailed 1D simulation model of the hydrogen-enriched natural gas SI engine was built according to realistic engine layout in the lab with practical boundary conditions, and validated against the experimental data. Four different types of EGR systems were comprehensively investigated, including a low-pressure (LP) EGR, a high-pressure (HP) EGR, their combinations, and an internal EGR, using the validated 1D simulation model of the hydrogen-enriched natural gas SI engine for their combustion, performance, and emissions characteristics. The results indicated that the peak combustion pressure of the in-cylinder pressure decreased with increase in EGR ratio either using the HP, LP, or combined HP-LP systems. The NOx emissions with the HP EGR were observed to be lowest of all types of EGR systems. Combined the 10% HP EGR ratio with the 5% LP EGR ratio (total 15% EGR ratio) was predicted to achieve the highest indicated thermal efficiency compared with other EGR strategies. As for the internal EGR, the peak combustion pressure and the heat release rate slightly increased with decrease in the valve overlap. Moreover, the indicated thermal efficiency firstly increased with decrease in overlap and then slightly declined. The internal EGR was mainly determined by the timing of the exhaust valve closing; However, it was not the only influence factor. The positive and negative waves in the intake and exhaust systems also played a crucial role in the gas exchange process and volumetric efficiency. © 2019 Elsevier Ltd
语种：
英文
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Two-dimensional knapsack-block packing problem
作者：
Zhou, Shengchao* ;Li, Xueping;Zhang, Kaike;Du, Ni
期刊：
Applied Mathematical Modelling ,2019年73:1-18 ISSN：0307-904X
通讯作者：
Zhou, Shengchao
作者机构：
[Zhou, Shengchao] Cent South Univ Forestry & Technol, Sch Logist, Changsha 410004, Hunan, Peoples R China.;[Zhang, Kaike; Li, Xueping] Univ Tennessee, Dept Ind & Syst Engn, Knoxville, TN 37996 USA.;[Du, Ni] Hunan Agr Univ, Sch Engn, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Zhou, Shengchao] C;Cent South Univ Forestry & Technol, Sch Logist, Changsha 410004, Hunan, Peoples R China.
关键词：
Two-dimensional knapsack problem;Block packing;Bin packing problem;Integer linear programming
摘要：
We study the two-dimensional knapsack problem with block packing constraints that is originated from an agricultural company when placing its seed experiments into test fields. The problem extends the classical knapsack problem by considering a block packing requirement. In this problem, a single bin is divided into many disjoint blocks and each block is a union of rectangles. If an item is placed, it should be contained in one of the blocks. The objective is to select a subset of the items to be packed into the bin to maximize the space usage, or equivalently, to minimize the wasted space. We propose three types of mathematical models for addressing the problem. The efficiency of the proposed models is analyzed through numerical studies. © 2019 Elsevier Inc.
语种：
英文
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NaCl溶液处理亚热带土壤水分特征曲线差异与模型优选
作者：
胡传旺;王辉;武芸;卢佳宇;刘常
期刊：
农业机械学报 ,2018年49(4):290-296,329 ISSN：1000-1298
通讯作者：
Wang, Hui(wanghuisb@126.com)
作者机构：
[胡传旺] College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China;[刘常; 王辉; 卢佳宇; 武芸] College of Engineering, Hunan Agricultural University, Changsha, 410128, China
通讯机构：
College of Engineering, Hunan Agricultural University, Changsha, China
关键词：
亚热带土壤;钠盐溶液;土壤水分特征曲线;模型
摘要：
携带大量盐分的低质水长期灌溉导致土壤存在极大的物理化学特性退化风险,为了探究盐分对土壤水分特征曲线影响的差异性,采用压力膜法对亚热带地区粘性潮土、沙性潮土、红壤、紫色土、水稻土等5种土壤进行室内测定,对比分析了各土壤在0、5、10、15 g/L等4个钠盐浓度水平下土壤水分特征曲线的差异,并利用RETC软件结合数理统计方法确定了各土壤不同钠盐浓度水平下相应的最优拟合模型。结果表明:钠盐处理均可提高各土壤的持水能力,且粘粒含量较高的土壤影响显著;钠盐处理减少了粘性潮土、沙性潮土和红壤的有效含水率,分别最大减少了40.8%、30.5%、31.5%,却提高了紫色土、水稻土有效含水率,分别最大提高了45.7%、28.9%。粘粒含量少或低浓度盐溶液处理的土壤水分特征曲线以BC模型拟合最优,而粘粒含量多且高浓度盐溶液处理的以DP-M模型拟合最优。
语种：
中文
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Pricing and Service Quality Guarantee Decisions in Logistics Service Supply Chain with Fairness Concern
作者：
Du, Ni* ;Han, Qinglan
期刊：
ASIA-PACIFIC JOURNAL OF OPERATIONAL RESEARCH ,2018年35(5):1850036 ISSN：0217-5959
通讯作者：
Du, Ni
作者机构：
[Han, Qinglan; Du, Ni] Cent S Univ, Sch Business, Changsha 410083, Hunan, Peoples R China.;[Du, Ni] Hunan Agr Univ, Coll Engn, Changsha, Hunan, Peoples R China.
通讯机构：
[Du, Ni] C;[Du, Ni] H;Cent S Univ, Sch Business, Changsha 410083, Hunan, Peoples R China.;Hunan Agr Univ, Coll Engn, Changsha, Hunan, Peoples R China.
关键词：
Logistics service supply chain;pricing;service quality defect rate guarantee;fairness concerns;Stackelberg game
摘要：
Although existing contributions that explore service quality guarantee problem of a logistic service supply chain (LSSC) consider fairness concern behavior of one member, little attention is paid to considering the combination of members' fairness concern and the joint decision of pricing and service quality guarantee in LSSC. Therefore, it is necessary to research how different fairness concern affects the joint decision of pricing and service quality guarantee in an LSSC. First considering a price and quality-sensitive logistics service market, a basic model without fairness concern of a customized LSSC is established. Then, a new model with fairness concern of a decentralized LSSC is constructed based on the basic model. The optimal decision of the LSSC with fairness concern is investigated in three cases. In each case, we analyze the effect of fairness concern on the optimal decision, and the expected profits and utilities. Finally, some numerical studies are shown to verify our theoretical analyses and some managerial insights are given. © 2018 World Scientific Publishing Co.
语种：
英文
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A random-keys genetic algorithm for scheduling unrelated parallel batch processing machines with different capacities and arbitrary job sizes
作者：
Zhou, Shengchao;Xie, Jianhui* ;Du, Ni;Pang, Yan
期刊：
Applied Mathematics and Computation ,2018年334:254-268 ISSN：0096-3003
通讯作者：
Xie, Jianhui
作者机构：
[Pang, Yan; Zhou, Shengchao] Cent South Univ Forestry & Technol, Sch Logist, Changsha 410004, Hunan, Peoples R China.;[Xie, Jianhui] Sun Yat Sen Univ, Lingnan Coll, Guangzhou 510275, Guangdong, Peoples R China.;[Du, Ni] Hunan Agr Univ, Sch Engn, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Xie, Jianhui] S;Sun Yat Sen Univ, Lingnan Coll, Guangzhou 510275, Guangdong, Peoples R China.
关键词：
Scheduling;Unrelated parallel machines;Batch processing machines;Random-keys genetic algorithm
摘要：
A batch processing machine (BPM) can simultaneously process several jobs and has wide applications in various industrial environments. This paper studies the problem of minimizing makespan on unrelated parallel BPMs with non-identical job sizes and arbitrary release times. In the environment of unrelated machines, each machine has a processing speed for each job. The unrelated BPM problem is the most general case of parallel BPM problems and is closer to actual production conditions. The problem under study is NP-hard. We present two lower bounds for the problem. Then a genetic algorithm based on random-keys encoding is proposed to solve the problem. The performance of the proposed algorithm is compared with a commercial solver (ILOG CPLEX) and two meta-heuristics published in the literature: a recent iterated greedy algorithm and a particle swarm optimization algorithm. Computational experiments show that the proposed algorithm produces better solutions compared to the other methods. The quality of the proposed lower bounds is evaluated as well. © 2018 Elsevier Inc.
语种：
英文
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A multi-objective differential evolution algorithm for parallel batch processing machine scheduling considering electricity consumption cost
作者：
Zhou, Shengchao;Li, Xiaolin* ;Du, Ni;Pang, Yan;Chen, Huaping
期刊：
Computers & Operations Research ,2018年96:55-68 ISSN：0305-0548
通讯作者：
Li, Xiaolin
作者机构：
[Pang, Yan; Zhou, Shengchao] Cent South Univ Forestry & Technol, Sch Logist, Changsha 410004, Hunan, Peoples R China.;[Li, Xiaolin] China Univ Min & Technol, Sch Mines, Xuzhou 221116, Jiangsu, Peoples R China.;[Du, Ni] Hunan Agr Univ, Sch Engn, Changsha 410128, Hunan, Peoples R China.;[Chen, Huaping] Univ Sci & Technol China, Sch Management, Hefei 230026, Anhui, Peoples R China.
通讯机构：
[Li, Xiaolin] C;China Univ Min & Technol, Sch Mines, Xuzhou 221116, Jiangsu, Peoples R China.
关键词：
Batch processing machines;Differential evolution algorithm;Multi-objective optimization;Sustainable scheduling;Total electricity cost
摘要：
The manufacturing industry consumes massive amounts of energy and produces great numbers of greenhouse gases every year. Recently, an increasing attention has been paid to the energy efficiency of the manufacturing industry. This paper considers a parallel batch processing machine (BPM) scheduling problem in the presence of dynamic job arrivals and a time-of-use pricing scheme. The objective is to simultaneously minimize makespan, a measure of production efficiency and minimize total electricity cost (TEC), an indicator for environmental sustainability. A BPM is capable of processing multiple jobs at a time, which has wide applications in many manufacturing industries such as electronics manufacturing facilities and steel-making plants. We formulate this problem as a mixed integer programming model. Considering the problem is strongly NP-hard, a multi-objective differential evolution algorithm is proposed for effectively solving the problem at large scale. The performance of the proposed algorithm is evaluated by comparing it to the well-known NSGA-II algorithm and another multi-objective optimization algorithm AMGA. Experimental results show that the proposed algorithm performs better than NSGA-II and AMGA in terms of solution quality and distribution. © 2018 Elsevier Ltd
语种：
英文
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基于无人机遥感影像的水稻种植信息提取
作者：
李明;黄愉淇;李绪孟;彭冬星;谢景鑫
期刊：
农业工程学报 ,2018年34(4):108-114 ISSN：1002-6819
作者机构：
[黄愉淇; 李明; 谢景鑫; 彭冬星] College of Engineering, Hunan Agricultural University, Changsha, 410128, China;[李明] Hunan Soar Star Aviation Technology Co. Ltd, Changsha, 410100, China;[李绪孟] College of Science, Hunan Agricultural University, Changsha, 410128, China
关键词：
无人机;遥感;农作物;可见光;水稻;二分类
摘要：
水稻是中国南方最主要的粮食作物,种植面积波动对国家粮食稳定有很大影响。通过无人机遥感试验获取多幅有重叠区域的图像,使用Agisoft photoscan软件拼接重构试验区的完整图像,利用多尺度分割方法将试验区域分割成若干对象,并基于统计方法提取对象的光谱特征、几何特征和纹理特征;然后,建立识别水稻地块的二分类Logistic回归模型,特征指标为形状指数、红色均值、红色标准偏差、最大化差异度量、灰度共生矩阵同质性和灰度共生矩阵非相似性。结果表明:模型辨识训练样本集的正确率为100%,辨识检验样本的正确率为97%,模型应用于辨识验证区域水稻田块,总体正确率为98%。最后基于累计像素方法测算水稻田块的面积,并与目视解译测算的结果对比,面积误差小于3.5%,研究方法识别水稻田块效果好,面积测算准确率高。因此,该研究对利用无人机遥感影像普查水稻种植信息具有一定的适用性。
语种：
中文
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油菜钵体苗移栽栽植孔成型机设计与试验
作者：
向伟;吴明亮;官春云;贺一鸣;罗海峰;...
期刊：
农业机械学报 ,2017年48(10):40-48,58 ISSN：1000-1298
通讯作者：
Wu, Mingliang(mlwu@hunau.edu.cn)
作者机构：
[吴明亮; 罗海峰; 贺一鸣; 向伟; 颜波] College of Engineering, Hunan Agricultural University, Changsha, 410128, China;[官春云] College of Agronomy, Hunan Agricultural University, Changsha, 410128, China;[吴明亮; 罗海峰; 官春云; 贺一鸣; 向伟; 颜波] Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Changsha, 410128, China
通讯机构：
College of Engineering, Hunan Agricultural University, Changsha, China
关键词：
油菜;移栽;栽植孔;成孔机构
摘要：
为实现打穴式移栽机高效成型满足农艺要求栽植孔,基于打孔移栽作业的工作特点,融合油菜移栽农艺要求,设计了一种纯滚动式油菜移栽栽植孔成型机。通过分析纯滚动机构运动机理,研究成孔机构的运动参数方程,建立成型栽植孔的参数方程。采用Matlab软件生成栽植孔理论轮廓线,并生成成型栽植孔的外形图,运用CATIA软件进行仿真分析得出成型栽植孔的轮廓曲线图,并将上述图形进行拟合模拟,验证了成孔机构结构参数与运动参数的合理性。试制样机,进行田间试验,试验结果表明:机具以慢2挡工作状态下前进速度为1.80~1.96km/h,作业效率达到0.306~0.333hm~2/h,在黏土、壤土和砂土3种土壤中试验,其成孔的平均合格率分别达到了94.4%、93.3%、90.4%,表明研制的成孔机能成型满足设计要求的栽植孔。
语种：
中文
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New insights into the activity of a biochar supported nanoscale zerovalent iron composite and nanoscale zero valent iron under anaerobic or aerobic conditions
作者：
Peng, Xiangqi;Liu, Xiaocheng;Zhou, Yaoyu* ;Peng, Bo;Tang, Lin* ;...
期刊：
RSC Advances ,2017年7(15):8755-8761 ISSN：2046-2069
通讯作者：
Zhou, Yaoyu;Tang, Lin
作者机构：
[Liu, Xiaocheng; Peng, Xiangqi; Zhou, Yaoyu; Luo, Lin] Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Hunan, Peoples R China.;[Zeng, Guangming; Deng, Yaocheng; Tang, Lin; Peng, Bo; Tang, Jing] Hunan Univ, Coll Environm Sci & Engn, Changsha 410082, Hunan, Peoples R China.;[Yao, Bangsong] Hunan Agr Univ, Coll Engn, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Zhou, Yaoyu; Tang, Lin] H;Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Hunan, Peoples R China.;Hunan Univ, Coll Environm Sci & Engn, Changsha 410082, Hunan, Peoples R China.
摘要：
In this work, to gain insight into the mechanism of p-nitrophenol (PNP) removal using the reactivity of a biochar supported nanoscale zerovalent iron composite (nZVI/biochar) and nanoscale zero valent iron (nZVI) under anaerobic or aerobic conditions, batch experiments and models were conducted. The PNP removal rate in the more acidic solutions was higher, while it was significantly suppressed at higher pH, especially at pH 9.0. The peak value of the apparent rate constants suggests that the reactivity of nZVI/biochar could be much stronger than that of nZVI under the same aeration conditions. The modified Langmuir–Hinshelwood kinetic model could successfully describe the PNP removal process using nZVI/biochar or nZVI. The reaction constants obtained through a Langmuir–Hinshelwood mechanism under different aeration conditions followed the trend nZVI/biochar (N2) > nZVI/biochar (air) > nZVI (N2) > nZVI (air), indicating that nZVI/biochar under anaerobic conditions exhibits enhanced activity for the degradation of PNP. The nZVI/biochar under anaerobic conditions has the lowest Arrhenius activation energy of PNP degradation–adsorption, suggesting that the surface interaction of eliminating PNP has a low energy barrier. In addition, TOC removal under anaerobic conditions was negligible compared with that under the aerobic system and the total number of iron ions leaching at solution pH 3.0 in the nZVI/biochar or nZVI system under air aeration conditions was much higher than that under nitrogen aeration conditions. The profiles of the intermediates formed during the PNP degradation indicated that in the anaerobic environment, reduction was the predominant step in the removal process, while the degradation of PNP could be regarded as a combination of oxidation and reduction in an aerobic environment.
语种：
英文
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Experimental study on the performance, combustion and emission characteristics of a high compression ratio heavy-duty spark-ignition engine fuelled with liquefied methane gas and hydrogen blend
作者：
Liu, Jingping;Duan, Xiongbo* ;Yuan, Zhipeng;Liu, Qi;Tang, Qijun
期刊：
Applied Thermal Engineering ,2017年124:585-594 ISSN：1359-4311
通讯作者：
Duan, Xiongbo
作者机构：
[Liu, Jingping; Duan, Xiongbo; Yuan, Zhipeng; Liu, Qi] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Tang, Qijun] Hunan Agr Univ, Coll Engn, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Duan, Xiongbo] H;Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.
关键词：
Combustion;Emission;Heavy-duty spark-ignition engine;Hydrogen energy content;Liquefied methane gas;Performance
摘要：
The aim of this paper investigated the performance, combustion and emission characteristics of a high compression ratio heavy-duty spark ignition engine fuelled with liquefied methane gas (LMG) and different hydrogen blends under at low engine speed. In this study, a compression ignition engine was modified to inject hydrogen and LMG using port fuel injection in spark ignition mode. The results showed that the brake thermal efficiency increased with increasing percentage of hydrogen energy content. The equivalent fuel efficiency value dramatically decreased with increasing load and slightly decreased with increasing percentage of hydrogen energy content. In-cylinder pressures of all the blends with hydrogen are higher than that only LMG fuel. The heat release rate shifted to the top dead center (TDC) and the 50% combustion location was remarkably advanced with the increasing of hydrogen energy content. Furthermore, the maximum pressure rise rate increased and the location of the maximum pressure rise rate shifted to the TDC with increasing of hydrogen energy content, respectively. NOx emission dramatically increased with increasing load and hydrogen energy content, respectively. Conversely, HC and CO2 emission concentration declined with increasing of hydrogen energy content. CO emission concentration kept low value at all the loads. © 2017 Elsevier Ltd
语种：
英文
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Study on the steam-assisted Brayton air cycle for exhaust heat recovery of internal combustion engine
作者：
Deng, Banglin;Tang, Qijun* ;Li, Meng
期刊：
Applied Thermal Engineering ,2017年125:714-726 ISSN：1359-4311
通讯作者：
Tang, Qijun
作者机构：
[Deng, Banglin; Li, Meng] Shenzhen Univ, Coll Mechatron & Control Engn, Shenzhen 518060, Peoples R China.;[Tang, Qijun] Hunan Agr Univ, Coll Engn, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Tang, Qijun] H;Hunan Agr Univ, Coll Engn, Changsha 410128, Hunan, Peoples R China.
关键词：
Brayton air cycle;Exhaust heat recovery;IC engine;Rankine cycle;Recovery efficiency
摘要：
A steam-assisted Brayton air cycle (SBAC) is proposed for exhaust heat recovery (EHR) of internal combustion (IC) engine, which consists of a regenerated Brayton air cycle and an open Rankine steam cycle. The regenerated Brayton air cycle is coupled to IC engine exhaust pipe and used to directly recover IC engine exhaust heat. A steam generating plant is coupled to IC engine exhaust pipe behind the Brayton air cycle which uses IC engine exhaust heat to generate steam, and then the steam is injected into the power turbine of Brayton air cycle. In this way, the exhaust heat of IC engine can be recovered twice. The simulation model was built by using GT-Power and then the working processes of SBAC were investigated under IC engine full load. On this basis, the recovery potential of exhaust heat through this SBAC was revealed and the influence factors were analyzed. Results show that, EHR efficiency of this SBAC is determined by both the cycle parameters (such as pressure, temperature and flow rate of working medium air) and engine operating conditions. Under the fixed engine operating conditions, the maximum EHR efficiency first increases and then decreases with working pressure increasing. Since the effective working pressure, temperature as well as air flow rate of EHR system are influenced by IC engine speed, the maximum EHR efficiency increases with IC engine speed and comes up to 7.0% at 6000r/min, which is obvious higher than the previous studies due to the complementary steam. The research results indicate that the proposed SBAC is an effective way for IC engine EHR. © 2017 Elsevier Ltd
语种：
英文
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Effect of grouser height on tractive performance of tracked mining vehicle
作者：
Li, Junzheng* ;Liu, Shaojun* ;Dai, Yu
期刊：
Journal of the Brazilian Society of Mechanical Sciences and Engineering ,2017年39(7):2459-2466 ISSN：1678-5878
通讯作者：
Li, Junzheng;Liu, Shaojun
作者机构：
[Dai, Yu; Li, JZ; Liu, Shaojun; Li, Junzheng] Cent S Univ, Coll Mech & Elect Engn, Changsha 410083, Hunan, Peoples R China.;[Li, Junzheng] Hunan Agr Univ, Coll Engn, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Li, JZ; Liu, SJ] C;[Li, Junzheng] H;Cent S Univ, Coll Mech & Elect Engn, Changsha 410083, Hunan, Peoples R China.;Hunan Agr Univ, Coll Engn, Changsha 410128, Hunan, Peoples R China.
关键词：
Tracked vehicle;Seabed soft sediments;Simulation experiment;Driving force;Tractive performance;Grouser height
摘要：
The aim of this study is to establish a single track shoe with grouser driving model to optimize the track structural parameters and improve the tractive performance of the tracked mining vehicle on soft sediments. The calculation formula of each component force and total driving force about grouser height was obtained through theoretical analysis. The basic parameters and the relationship of mechanical properties for computer simulation were also obtained by the testing experiment using soil simulation whose main physical and mechanical properties are close to the deep-sea sediments. The computer simulation results show that the total driving force of the track improved rapidly with the increases of the grouser height and the slip rate. It keeps rising until it reaches a maximum value. And then it will maintain a steady value when the slip rate exceeds 40 %. The total driving force also improved with the increase of the ratio (slip rate/grouser height). When the grouser height is in the range of 0–15 cm, the total driving force keeps increasing gradually with the increase of the slip rate until it reached the stable state. When the grouser height is in the range of 15–30 cm, the total driving force keeps increasing to a maximum value rapidly with the increasing of slip rate first, and then keeps decreasing gradually. The greater the increase of grouser height, the faster the decrease of the total driving force.
语种：
英文
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秸秆灰混凝土力学性能试验及强度预测
作者：
张强;李耀庄;刘保华;徐志胜
期刊：
农业工程学报 ,2017年33(2):259-265 ISSN：1002-6819
通讯作者：
Liu, Baohua(344419897@qq.com)
作者机构：
[徐志胜; 张强; 李耀庄] Institute of Disaster Prevention Science and Safety Technology, Central South University, Changsha, 410128, China;[刘保华] College of Engineering, Hunan Agricultural University, Changsha, 410000, China
通讯机构：
College of Engineering, Hunan Agricultural University, Changsha, China
关键词：
秸秆;混凝土;力学性能;神经网络;油菜秸秆;秸秆灰混凝土;小波神经网络
摘要：
为了优化混凝性能,减少水泥产业耗能,尝试采用以部分秸秆灰替代水泥制备混凝土。该文通过试验对油菜秸秆灰混凝土拉压性能进行了研究,得到秸秆灰质量分数和水胶比对秸秆灰混凝土拉压性能的影响规律,如当秸秆灰质量分数增大时,混凝土拉压性能呈下降趋势;当水胶比过大时,混凝土力学性能急剧下降。同时提出秸秆灰混凝土抗拉性能与抗压性能间的线性函数关系以及混凝土轴心抗压强度计算公式,并与其他混凝土抗压强度公式进行比对验证。采用小波神经网络的预测方法,引入随机函数,对试验数据抽样进行训练,而后预测数据并与试验数据进行比对,计算误差,并将预测数据用于该文提出的拉压公式进行验证,结果表明验证较好。最后试验结果表明:当秸秆灰替代掺量为10%时,秸秆灰混凝土劈裂抗拉强度下降了25%,抗压强度仅下降了8%;当替代掺量为20%时,抗压强度下降了31%。
语种：
中文
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犁旋组合式油菜播种开沟起垄装置设计
作者：
包攀峰;吴明亮;官春云;罗海峰;贺一鸣;...
期刊：
农业工程学报 ,2017年33(20):23-31 ISSN：1002-6819
通讯作者：
Wu, Mingliang(mlwu@hunau.edu.cn)
作者机构：
[吴明亮; 罗海峰; 包攀峰; 贺一鸣; 向伟] College of Engineering, Hunan Agricultural University, Changsha, 410128, China;[官春云] Oilseeds Crops Institute, Hunan Agricultural University, Changsha, 410128, China;[吴明亮; 罗海峰; 官春云; 包攀峰; 贺一鸣; 向伟] Collaborative Innovation Center for Grain and Oil Crops in South China, Changsha, 410128, China;[吴明亮; 罗海峰; 包攀峰; 贺一鸣; 向伟] Hunan Provincial Engineering Technology Research Center for Modern Agricultural Equipment, Changsha, 410128, China
通讯机构：
College of Engineering, Hunan Agricultural University, Changsha, China
关键词：
农业机械;设计;农作物;油菜;犁旋组合式;开沟;垄作
摘要：
针对中国南方稻田土壤黏重、高含水率土壤使传统油菜开沟起垄机构作业后沟壁易垮塌影响垄沟排水和后期油菜生长,研制了犁旋组合式油菜播种开沟起垄装置。设计了犁体式成沟起垄部件的入土角、翼板角度和翼板长度等结构参数,优化了旋转式切土部件的旋耕弯刀、沟壁切土直刀的安装方式及其结构参数。在室内土槽进行了多因素二次正交旋转组合试验,结果表明:影响沟面宽稳定度、垄高稳定度的主次顺序为沟壁切土直刀的回转半径、翼板长度、翼板角度;影响回土率的主次顺序为翼板长度、翼板角度、沟壁切土直刀的回转半径。装置最优的工作参数组合为沟壁切土直刀的回转半径为351 mm,翼板长度为78 cm,翼板角度为41°。对最优工作参数组合进行试验验证,各评价指标试验结果与软件分析值的相对偏差均不超过1%。该研究可为油菜垄作高产栽培提供技术参考。
语种：
中文
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Dynamic modeling of the ventilated double skin façade in hot summer and cold winter zone in China
作者：
Wang, Yanjin;Chen, Youming* ;Zhou, Juan
期刊：
Building and Environment ,2016年106:365-377 ISSN：0360-1323
通讯作者：
Chen, Youming
作者机构：
[Chen, Youming; Wang, Yanjin] Hunan Univ, Coll Civil Engn, Changsha 410082, Hunan, Peoples R China.;[Zhou, Juan] Hunan Agr Univ, Coll Engn, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Chen, Youming] H;Hunan Univ, Coll Civil Engn, Changsha 410082, Hunan, Peoples R China.
关键词：
Airflow network;Double skin façade;Dynamic optical model;Hot summer and cold winter zone;Improved zonal approach;Mechanical ventilation
摘要：
An improved zonal approach with a dynamic optical model of the venetian blind and airflow network model is proposed to model the mechanical ventilated double skin façade (DSF) in hot summer and cold winter zone in China. It is validated by the experiment in both cooling and heating season cases. The comparison results show that the simulated results fit well with the measured results. The effects of the ventilation rate and slat angle on the inner glass temperature and heat gains through the DSF are discussed. Both increase ventilation rate and slat angle can decrease the inner glass temperature and heat gains through the DSF, but the decrease range is greater by increasing the slat angle. Compared to the slat angle at 0°, heat gains can be reduced by 63% when the slat angle at 60°. The proposed method can not only meet the requirements of engineering application, but also spend less computational time in modeling DSF dynamically in hot summer and cold winter zone in China. It can be used to evaluate the thermal performance and simulate the annual energy consumption of DSF. © 2016 Elsevier Ltd
语种：
英文
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基于CFD-DEM耦合的水力旋流器水沙运动三维数值模拟
作者：
喻黎明;邹小艳;谭弘;严为光;陈立志;...
期刊：
农业机械学报 ,2016年47(1):126-132 ISSN：1000-1298
作者机构：
[严为光; 喻黎明; 谭弘; 邹小艳] School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha, China;[熊子维] College of Engineering, Hunan Agricultural University, Changsha, China;[陈立志] College of Mechanical and Electrical Engineering, Central South University, Changsha, China;[严为光; 喻黎明; 谭弘; 邹小艳] Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention, Changsha University of Science and Technology, Changsha, China
关键词：
水力旋流器;水沙运动;离散元法;计算流体力学;耦合;数值模拟
摘要：
针对水力旋流器内流场运动复杂、沙粒运动规律难以掌握的问题,运用基于颗粒动力学理论的欧拉-拉格朗日液固多相湍流模型,对水力旋流器内的水沙两相三维流动进行了CFD-DEM耦合数值模拟研究,分析了水力旋流器内单个沙粒的轨迹线、速度和沙粒群的运动规律、分布特性等。模拟结果表明,沙粒粒径越小,沙粒向下运行的距离越短,越容易从下降流中进入到上升流中,越难以分离。粒径为40μm的沙粒,在圆柱体与圆锥体交界面处出现沙粒峰值,分离效果易受影响,而50μm和60μm沙粒在圆锥体部分出现峰值,具有较好的分离效果。通过跟踪单个沙粒和沙粒群的运动可知,沙粒在圆柱体内主要作圆周运动,进入到圆锥体部分,沙粒既有圆周运动,又有明显的进入沉沙口的直线运动。分析大量沙粒个体和群体运动以及群体分布情况能从微观角度了解水力旋流器的分离效率,是水力旋流器性能研究的有效手段。
语种：
中文
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动定刀同轴水稻秸秆切碎还田装置结构设计与试验
作者：
邱进;吴明亮;官春云;方友祥;李小聪
期刊：
农业工程学报 ,2015年31(10):11-19 ISSN：1002-6819
通讯作者：
Wu, Mingliang
作者机构：
[吴明亮; 邱进; 李小聪] College of Engineering, Hunan Agricultural University, Changsha, China;[方友祥] Yiyang Zijiang Combine Harvester Development Co. Ltd, Yiyang, China;[官春云] Oilseeds Crops Institute, Hunan Agricultural University, Changsha, China;[吴明亮; 邱进; 李小聪] Collaborative Innovation Center for Grain and Oil Crops in South China, Changsha, China;[吴明亮; 邱进; 李小聪] Hunan Provincial Engineering Technology Research Center for Modern Agricultural Equipment, Changsha, China
通讯机构：
College of Engineering, Hunan Agricultural University, Changsha, China
关键词：
农业机械;机械化;设计;稻秸秆;切碎;秸秆还田
摘要：
针对中国南方稻田留茬高、土壤黏重,油菜栽种复式作业机耕整地作业部件易缠草、壅泥,影响作业质量和油菜出苗的难题,提出了将田间稻秸秆收集切碎并绕过耕作部件后均匀覆盖于播种行行间的种植方法,研发了多功能油菜覆草直播播种机,围绕该机器设计了一种动刀与定刀及风送叶片同轴安装的稻秸秆切碎装置,并分别对稻秸秆的"站秆"和"残茬"进行切碎台架试验。结果表明:喂入压辊转速、动刀转轴转速、动定刀间隙3个影响因素对切碎长度合格率、功耗影响显著;对"站秆"和"残茬"切碎的各因素取值为:喂入压辊转速399.2、401.64 r/min,动刀转轴转速968.12、977.23 r/min,动定刀间隙0.52、0.49 mm时,稻秸秆切碎合格长度率为95.78%、96.98%,功率损耗为3.09、2.68 kW。经整机田间试验,该装置的秸秆田间覆盖效果达到油菜种植农艺要求。该研究为多功能油菜覆草直播播种机产业化提供了技术参考。
语种：
中文
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Gas-solid two-phase separation operation mechanism for 4LZ-0.8 rice combine harvester cleaning device
作者：
任述光;谢方平;王修善;刘大为;李旭;...
期刊：
农业工程学报 ,2015年31(12):16-22 ISSN：1002-6819
通讯作者：
Xie, Fangping
作者机构：
[谢方平; 任述光; 王修善; 刘大为; 李旭] College of Engineering Hunan Agriculture University, Changsha, China;[陈立永] Hunan Nongguang Agricultural Equipment Limited company, Loudi, China;[谢方平; 任述光; 王修善; 刘大为; 李旭] Collaborative Innovation Center of Southern Chinese Grain and Oilseed, Changsha, China;[谢方平; 任述光] Hunan Provincial Engineering Technology Research Center for Modern Agricultural Equipment, Changsha, China
通讯机构：
College of Engineering Hunan Agriculture University, Changsha, China
关键词：
农业机械;联合收割机;农作物;两相流;清选;空气动力学;分离;脱粒混合物
摘要：
为解决小型水稻联合收割机脱净率和损失率问题,提高脱粒清选质量,利用两相流动力学理论,分析了4LZ-0.8型水稻联合收割机脱粒清选分流筒中气流和杂物颗粒两相流动的规律。建立了杂物颗粒流的运动微分方程,导出了分离筒中杂物漂浮速度计算的一种方法,通过比较不同粒径、密度的物料的悬浮速度,得到了杂物颗粒最高速度与气流速度之比随气流速度变化的关系曲线,气流和杂物在分流筒及吸风管中运动时的压力损失随气流速度变化呈现先降后升的规律,压力损失中以加速损失和摩擦损失为主,各约占30%和26%。压力损失曲线存在最小值,此时的气流速度定义为经济气流速度。在喂入量为0.8 kg/s,谷草比为3:1脱粒条件下的经济的清选气流速度9.2 m/s,压力损失为630 Pa。该研究为4LZ-0.8型水稻联合收割机脱粒清选部件的参数优化设计及风机的选择提供了理论依据。
语种：
中文
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