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AMMONIA DISPERSION FROM MULTI-FLOOR VERSUS STANDARD SINGLE-FLOOR PIG PRODUCTION FACILITIES BASED ON COMPUTATIONAL FLUID DYNAMICS SIMULATIONS

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Frontiers of Agricultural Science and Engineering 2023年第3期10卷 374-389页

作者： Yicong XIN Li RONG Gunther SCHAUBERGER dejia liu Xiusong LI Zhihua YANG Songming ZHU Dezhao liu Key Laboratory of Equipment and Informatization in Environment Controlled Agriculture Ministry of Agriculture and Rural AffairsKey Laboratory of Intelligent Equipment and Robotics for Agriculture of Zhejiang ProvinceInstitute of Agricultural Bio-Environmental EngineeringCollege of Biosystems Engineering and Food ScienceZhejiang UniversityHangzhou 310058China Department of Civil and Architectural Engineering—Building Science Aarhus UniversityAarhus C 8000Denmark WG Environmental Health Unit for Physiology and BiophysicsUniversity of Veterinary MedicineA-1210 ViennaAustria Big Herdsman Machinery Co. Ltd.Qingdao 266000China Zhejiang Huatong Meat Products Co. Ltd.Yiwu 322000China

Multi-floor buildings for raising pigs have recently attracted widespread attention as an emerging form of intensive livestock production especially in eastern China,due to the fact that they can feed a much larger number of animals per unit area of land and thus alleviate the shortage of land available for standard single-floor pig production facilities.However,this more intensive kind of pig building will pose new challenges to the local environment in terms of pollutant dispersion.To compare the dispersion air pollutants(ammonia as a representative)emitted from multi-versus single-floor pig buildings,ammonia dispersion distance and concentration gradients were investigated through three-dimensional simulations based on computational fluid dynamics.The validation of an isolated cubic model was made to ensure the simulation method was effective.The effects of wind direction,wind speed and emission source concentration at 1.5 m(approximate human inhalation height)during summer were investigated.The results showed that the ammonia dispersion distance of the multi-floor pig building was far greater than that of the single-floor building on a plane of Z=1.5 m.When the wind direction was 67.5°,the wind speed was 2 m·s^(−1) and the emission source concentration was 20 ppmv,the dispersion distance of the multi-floor pig building could reach 1380 m.Meanwhile,the ammonia could accumulate in the yard to 7.68 ppmv.Therefore,future site selection,wind speed and source concentration need to be given serious consideration.Based on the simulation used in this study with source concentration is 20 ppmv,the multi-floor pig buildings should be located 1.4 km away from residential areas to avoid affecting residents.The results of this study should guidance for any future development of multi-floor pig buildings.

关键词： pig building computational fluid dynamics ammonia dispersion

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Influence of texture distribution in magnesium welds on their non-uniform mechanical behavior:A CPFEM study

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Journal of Materials Science & Technology 2020年第11期42卷 168-176页

作者： Weijie Ren dejia liu Qing liu Renlong Xin Joint International Laboratory for Light Alloys(MOE) College of Materials Science and EngineeringChongqing UniversityChongqing 400044China College of Materials Science and Engineering East China Jiaotong UniversityNanchang3300J3China Key Laboratory for Light-weight Materials NanjingTech UniversityNanjing211816China

Recent studies indicate that the texture distribution in friction stir welded(FSW)Mg alloys can be tailored and hence improve the joint performance.In this work,a crystal plasticity finite element modeling(CPFEM)was performed to understand the effects of texture distribution in stir zone(SZ)on the nonuniform plastic deformation and fracture localization.In total,six kinds of observed or purposely tilted texture distributions were modelled.The"concave-convex"appearance,as commonly observed in the tensile sample,was successfully simulated.It reveals that the mirror-symmetrical distribution of basal planes in the region of easy to activate basal slip(EABS)determined the"concave-convex"appearance in SZ-center.The asymmetrical appearance exchanged on plane A and plane B when the directions of basal planes were switched in the two EABS regions.Furthermore,the asymmetrical feature of plastic deformation was changed with varying the texture distribution in SZ.The"embossed"feature became more obvious in SZ-center first,and then gradually weakened with the c-axis rotated away from the weld plate plane.Severe necking was successfully simulated in SZ-center of FSW-H joint and in SZ-side of FSW-L joint.That might determine the observed fracture morphology.We believe that this simulation study is helpful for further improving the performance of FSW Mg joints.

关键词： Friction stir welding Magnesium alloy CPFEM Non-uniform deformation Fracture

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数字化发展对先进制造企业服务创新的影响研究——基于企业动态能力视角

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中国软科学 2023年第3期 150-161页

作者：张昊刘德佳哈尔滨理工大学经济与管理学院黑龙江哈尔滨150040 哈尔滨工程大学经济管理学院黑龙江哈尔滨150001

在数字经济时代背景下,数字化发展已成为推动先进制造企业迈向高端价值链的有效路径。基于中国A股上市公司2015—2021年的数据,研究数字化发展对先进制造企业服务创新的影响及内在作用机制。结果表明:数字化发展能够促进先进制造企业服... 详细信息

在数字经济时代背景下,数字化发展已成为推动先进制造企业迈向高端价值链的有效路径。基于中国A股上市公司2015—2021年的数据,研究数字化发展对先进制造企业服务创新的影响及内在作用机制。结果表明:数字化发展能够促进先进制造企业服务创新;企业动态能力在数字化发展与先进制造企业服务创新的关系中起中介作用;非沉淀性冗余资源在企业动态能力与服务创新之间起正向调节作用,而沉淀性冗余资源在企业动态能力与服务创新之间起负向调节作用。研究结论以期为先进制造企业服务创新理论研究与实践探索提供重要依据。

关键词：服务创新先进制造企业数字化发展企业动态能力冗余资源

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Enhanced fluorescence sensing of tetracycline with Ti_(2)C quantum dots

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Nano Research 2024年第4期17卷 3180-3188页

作者： dejia Hu ShangZuo Jiang Tianhao Xia Danyang Xiao Yan Li Yanbing Hou Jin Zhong Zhang Ying-Chih Pu School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Key Lab Luminescence&Optical Information Ministry EducationBeijing JiaoTong UniversityBeijing 100044China Department of Chemistry and Biochemistry University of CaliforniaSanta CruzCalifornia 95064USA Department of Materials Science "National University of Tainan"Tainan 700301TaiwanChina

Ti_(2)C quantum dots(QDs)with rich surface functional groups have been synthesized using a hydrothermal method,and used to detect tetracycline(Tc)based on enhanced fluorescence.The interaction between the surface functional groups of Ti_(2)C QDs and Tc enhanced the fluorescence of Tc at 514 nm,which is used to detect Tc quickly and accurately.Under optimal conditions,the fluorescence intensity was linear to the concentration of Tc in the range of 50.0–30.0μM,with a detection limit of 21.6 nM.Furthermore,the Tc-Ti_(2)C QDs detection system was evaluated for detection of Tc in milk and artificial urine.This study demonstrates a new and simple strategy for Tc detection,which is important for food safety and human health.

关键词： Ti_(2)C MXene quantum dots tetracycline fluorescence enhancement detection

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AlMgLi_(0.5) Zn_(0.5) Cu_(0.2)轻质高熵合金的组织和耐腐蚀性研究

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材料导报 2022年第14期36卷 39-44页

作者：胡勇刘飞刘员员赵龙志焦海涛唐延川刘德佳华东交通大学材料科学与工程学院南昌330013 南昌市载运工具先进材料与激光增材制造重点实验室南昌330013

采用Al、Mg、Li、Cu、Zn五种元素,通过磁悬浮熔炼制备了AlMgLi_(0.5) Zn_(0.5) Cu_(0.2)轻质高熵合金。利用XRD、SEM分析了热处理对AlMgLi_(0.5) Zn_(0.5)-Cu_(0.2)轻质高熵合金微观组织形貌的影响。利用ES-D电子天平和CS350电化学工作... 详细信息

采用Al、Mg、Li、Cu、Zn五种元素,通过磁悬浮熔炼制备了AlMgLi_(0.5) Zn_(0.5) Cu_(0.2)轻质高熵合金。利用XRD、SEM分析了热处理对AlMgLi_(0.5) Zn_(0.5)-Cu_(0.2)轻质高熵合金微观组织形貌的影响。利用ES-D电子天平和CS350电化学工作站检测了AlMgLi_(0.5) Zn_(0.5) Cu_(0.2)轻质高熵合金的密度和耐腐蚀性。结果表明:AlMgLi_(0.5) Zn_(0.5) Cu_(0.2)轻质高熵合金的密度为2.851 g/cm^(3)。经过热处理后,AlMgLi_(0.5) Zn_(0.5) Cu_(0.2)轻质高熵合金晶界处含Mg_(32)(AlZn)_(49)相的共晶组织减少,形貌由条状变为点状。经过300℃热处理以后,FCC1相枝晶组织细化且变得更加均匀;FCC1相中的Cu元素固溶到基体内,提高了合金的耐腐蚀性能。但是经过300℃+120℃热处理后,FCC1相变为等轴状,FCC1基体表面有FCC2(富Cu相)析出,构成了微小腐蚀电池,降低了合金的耐腐蚀性能。

关键词：轻质高熵合金 AlMgLi 0.5 Zn 0.5 Cu 0.2 显微组织耐腐蚀性

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原位TiC-TiB_(2)/Al-12Si混杂铝基复合材料组织及耐腐蚀性能研究

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稀有金属材料与工程 2022年第10期51卷 3937-3942页

作者：胡勇刘员员符声启赵龙志焦海涛刘德佳唐延川华东交通大学材料科学与工程学院江西南昌330013

采用激光沉积制备了原位TiC-TiB_(2)/Al-12Si混杂铝基复合材料,通过XRD、OM、SEM、TEM和电化学测试分析了复合材料的微观组织和耐蚀性能。结果表明,原位TiC为细小弥散分布的多边形状、TiB_(2)为短棒状,两者均可作为Al的异质形核核心而... 详细信息

采用激光沉积制备了原位TiC-TiB_(2)/Al-12Si混杂铝基复合材料,通过XRD、OM、SEM、TEM和电化学测试分析了复合材料的微观组织和耐蚀性能。结果表明,原位TiC为细小弥散分布的多边形状、TiB_(2)为短棒状,两者均可作为Al的异质形核核心而细化晶粒。在3.5%NaCl溶液中,随着原位TiC-TiB_(2)增强相含量的增加,复合材料的自腐蚀电位正移,自腐蚀电流密度降低,阻抗模量值及相位角值增大,表明复合材料的耐蚀性增强。

关键词：原位 TiC-TiB_(2) 混杂铝基复合材料显微组织耐腐蚀性能

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Effectiveness and safety of acupuncture in treatment of pregnancyrelated symptoms:a systematic review and Meta-analysis

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Journal of Traditional Chinese Medicine 2024年第1期44卷 16-26页

作者： liu Tingting liu Tongou liu Mingfu School of Traditional Chinese Medicine Clinical Medicine Hubei University of Traditional Chinese MedicineWuhan 430000China First Clinical College of Hubei University of Traditional Chinese Medicine Wuhan 430000China Department of Acupuncture and Tuina Affiliated Hospital of Hubei University of Traditional Chinese MedicineHubei Provincial Hospital of Traditional Chinese MedicineWuhan 430000China

OBJECTIVE:To systematically evaluate the efficacy and safety of acupuncture(AM)in the treatment of pregnancyrelated symptoms such as acute vomiting during pregnancy.METHODS:We comprehensively searched the available literature up to November 2021,including Pub Med,Embase,Cochrane Library,Chinese Biomedical Literature Database,and China National Knowledge Infrastructure Database,for randomized controlled trials(RCTs)on AM for the treatment of severe vomiting,insomnia,pharyngeal and pelvic pain,mood abnormalities,and dyspepsia during pregnancy.RESULTS:Sixteen RCTs with a cumulative sample size of 1178 cases were included.Of these,964 patients were included in the Meta-analysis.The Meta-analysis results showed that AM was more efficient than Western medicine in treating discomfort during pregnancy[odds ratio(OR)=1.19,95%confidence interval(CI)(1.11,1.28),P<0.01].AM was better than the control group in improving the visual analog scale scores[standard mean difference(SMD)=0.62,95%CI(0.53,0.71),P<0.01].AM was superior to the control group in improving Numerical Rating Scale(NRS)symptom scores[OR=7.31,95%CI(3.36,15.94),P<0.01].There was no significant difference in adverse effects between the AM and sham-AM groups and the analgesic drug group[OR=0.70,95%CI(0.39,1.28),P=0.25],but the treatment and control groups had mild adverse effects with a low incidence.CONCLUSIONS:AM is more effective than other treatments or pharmacotherapy alone in the treatment of pregnancy-related symptoms,and is relatively safe.However,the quality of the included trials was rather poor,and high-quality studies are required to confirm our findings.

关键词： acupuncture pregnancy nausea vomiting sleep initiation and maintenance disorders low back pain pelvic pain mood abnormalities Meta-analysis systematic review

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先进制造企业服务创新转型演进逻辑及驱动机制研究——基于企业资源与能力视角

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科研管理 2023年第8期44卷 47-56页

作者：李庆雪綦天熠王莉静刘德佳哈尔滨理工大学经济与管理学院黑龙江哈尔滨150040 哈尔滨工程大学经济管理学院黑龙江哈尔滨150001

服务创新作为先进制造业转型升级新业态,是塑造先进制造业竞争优势的新引擎,先进制造企业服务创新转型演进的相关理论研究,成为学术界亟待突破的重要难题。本文基于企业资源与能力视角,运用多案例研究方法,在扎根理论编码分析基础上,厘... 详细信息

服务创新作为先进制造业转型升级新业态,是塑造先进制造业竞争优势的新引擎,先进制造企业服务创新转型演进的相关理论研究,成为学术界亟待突破的重要难题。本文基于企业资源与能力视角,运用多案例研究方法,在扎根理论编码分析基础上,厘清先进制造企业服务创新转型演进逻辑及驱动机制。研究发现:第一,先进制造企业服务创新转型经历“传统制造服务创新阶段-全生命周期管理服务创新阶段-智能制造服务数字化创新阶段”演化,并遵循“资源与能力提升-内外要素驱动-转型阶段演进”的服务创新转型演进逻辑;第二,服务创新转型各阶段需要依次满足资源的“利用开发-整合配置-智能优化”以及“服务认知-服务响应-动态服务创新”能力的提升条件;第三,先进制造企业分别受到服务价值及动态竞争环境、服务生态发展及服务效益、服务集成创新需求及服务反馈机制等内外要素共同驱动作用,促进服务创新转型演进与升级。研究旨在丰富服务创新转型的相关研究,并为先进制造业服务创新战略演进提供理论指导。

关键词：服务创新演进逻辑驱动机制企业资源企业能力

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Removal of Cr(Ⅵ)by glutaraldehyde-crosslinked chitosan encapsulating microscale zero-valent iron:Synthesis,mechanism,and longevity

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Journal of Environmental Sciences 2024年第8期142卷 115-128页

作者： Yijun Duan Fang liu Xiang liu Miao Li School of Environment Tsinghua UniversityBeijing 100084China Transportation Institute of Inner Mongolia University Hohhot 010070China

Microscale zero-valent iron(mZVI)has shown great potential for groundwater Cr(Ⅵ)remediation.However,low Cr(Ⅵ)removal capacity caused by passivation restricted the wide use of mZVI.We prepared mZVI/GCS by encapsulating mZVI in a porous glutaraldehydecrosslinked chitosan matrix,and the formation of the passivation layer was alleviated by reducing the contact between zero-valent iron particles.The average pore diameter of mZVI/GCS was 8.775 nm,which confirmed the mesoporous characteristic of this material.Results of batch experiments demonstrated that mZVI/GCS exhibited high Cr(Ⅵ)removal efficiency in a wide range of pH(2-10)and temperature(5-35℃).Common groundwater coexisting ions slightly affected m ZVI/GCS.The material showed great reusability,and the average Cr(Ⅵ)removal efficiency was 90.41%during eight cycles.In this study,we also conducted kinetics and isotherms analysis.Pseudo-second-order model was the most matched kinetics model.The Cr(Ⅵ)adsorption process was fitted by both Langmuir and Freundlich isotherms models,and the maximum Langmuir adsorption capacity of m ZVI/GCS reached243.63 mg/g,which is higher than the adsorption capacities of materials reported in most of the previous studies.Notably,the column capacity for Cr(Ⅵ)removal of a mZVI/GCS-packed column was 6.4 times higher than that of a mZVI-packed column in a 50-day experiment.Therefore,mZVI/GCS with a porous structure effectively relieved passivation problems of mZVI and showed practical application prospects as groundwater Cr(Ⅵ)remediation material with practical application prospects.

关键词： Chitosan Glutaraldehyde mZVI Cr(Ⅵ) Groundwater

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Frequency Regulation of VSC-MTDC System with Offshore Wind Farms

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 275-286页

作者： Haoyu liu Chongru liu North China Electric Power University Beijing 102206China

Frequency regulation of voltage source converter-based multi-terminal high-voltage direct current(VSC-MTDC)system with offshore wind farms enhances the frequency stability by compensating the power for a disturbed AC system.However,it is difficult to reasonably allocate frequency-regulation resources due to a lack of coordination mechanisms between wind farms and the MTDC system.Moreover,it is difficult for the frequency control of the wind farms to manage changes in wind speed;and the risk of wind-turbine stalls is high.Thus,based on the kinetic energy of wind turbines and the power margin of the converters,the frequency-regulation capability of wind turbines is evaluated,and a dynamic frequency-support scheme considering the real-time frequency-support capability of the wind turbines and system frequency evolution is proposed to improve the frequency-support performance.A power adaptation technique at variable wind speeds is developed;the active power in the frequency-support stage and restoration stage is switched according to the wind speed.A hierarchical zoning frequency-regulation scheme is designed to use the frequency-regulation resources of different links in the MTDC system with wind farms.The simulation results show that the novel frequency-regulation strategy maintains frequency stability with wind-speed changes and avoids multiple frequency dips.

关键词： Wind generation voltage source converter-based multi-terminal high-voltage direct current(VSC-MTDC) frequency regulation cooperative control adaptive control variable wind speed

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