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Adjusting the nutrient solution formula based on growth stages to promote the yield and quality of strawberry in greenhouse

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International Journal of agricultural and Biological engineering 2023年第2期16卷 57-64页

作者： Weizhong Yu Jianfeng Zheng Yingli Wang Fang Ji Baoying Zhu Key Laboratory of Agricultural Engineering in Structure and Environment of MARA College of Water Resources&Civil EngineeringChina Agricultural UniversityBeijing 100083China Beijing Changping District Management Center of Xiaotangshan Modern Agricultural Science and Technology Demonstration Park Beijing 102200China

To optimize the nutrient supply of strawberry,fertilization was reduced as much as possible on the premise of satisfying the elements needed for strawberry *** study put forward a modified nutrient solution formula(NM)by adjusting the ratios of N/K,K/Ca,NO_(3)^(-)-N/NH_(4)^(+)-N in vegetative growth,flowering and fruiting,and fruit expanding stages based on Yamasaki strawberry nutrient solution formula(NY).Taking the NY as the control group,the NM was verified with elevated-grown‘Ssanta’strawberry using three different substrates(Vulcanics-added substrate,Horticultural substrate,Comme rcial substrate)in *** results indicated that under the NM treatment,strawberry plants had better photosynthesis in the vegetative growth stage and flowering and fruiting stage,and the first crop yield and total crops yield per plant also increased by 20%.Although the vegetative growth stage was longer,it entered the full fruiting stage earlier so that the maturity stage was advanced one *** to strawberries grown in horticultural substrate irrigated with NY,the fruit yield per plant of‘Ssanta’strawberry grown in horticultural substrate irrigated with NM increased by 26%,and the sugar-acid ratio and vitamin C content of primary fruits reached 10.6 and 74.1 mg/100g,improving by 41%and 34%*** NM based on the growth stage can optimize the element needs of strawberry in all growth and development stages and maintain the substrate’s pH stability,improving the yield and quality of‘Ssanta’strawberry under substrate ***,it is recommended to use the horticultural substrate irrigated with the modified nutrient solution for the‘Ssanta’strawberries cultivation elevated in greenhouse to improve the economic benefit of strawberry cultivation.

关键词： elevated-grown strawberry nutrient solution formula substrate cultivation phenological stage fruit yield fruit quality

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A comprehensive set of criteria for evaluating thermal management systems of aerial vehicles

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Science China(Technological Sciences) 2023年第7期66卷 2093-2107页

作者： YIN HuiNing XUAN YiMin LIAN WenLei WANG TianYi School of Energy and Power Engineering Aero-engine Thermal Environment and Structure Key Laboratory of Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China

Thermal management has become a significant concern in the design of advanced air ***,an effective evaluation method is needed when designers need to evaluate aircraft thermal management systems *** paper proposes an evaluation method in which several evaluation directions concerned with thermal management systems(TMSs) are put forward to form an evaluation index *** effect of temperature control,heat sink utilization efficiency,energy utilization efficiency,flight performance penalty,thermal endurance,space occupancy ratio,and economy are chosen as the direction of evaluation for TMS,considering its primary function,system performance,and impact on aerial *** method is comprehensive,intuitive,and user-friendly,along with the intensely subjective user-defined weight parameters,which provide rational metrics for thermal management techniques involved in aerial *** evaluation method could potentially be helpful for designers to comprehensively analyze the performance of aircraft thermal management systems and provide a basis for practical *** examples are provided to demonstrate the application of the method to evaluating TMS comprehensively.

关键词： comprehensive evaluation method evaluation index system aircraft thermal management system

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Analytical modeling and approaches of multihelix cables incorporating with interwire mutual contacts

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Applied Mathematics and Mechanics(English Edition) 2024年第9期45卷 1633-1654页

作者： Zhichao ZHANG Xingzhe WANG Key Laboratory of Mechanics on Disaster and Environment in Western China The Ministry of Education of ChinaCollege of Civil Engineering and MechanicsKey Laboratory of Special Function Materials and Structure Design of Ministry of EducationLanzhou UniversityLanzhou 730000China College of Civil Science and Engineering Yangzhou UniversityYangzhou 225127Jiangsu ProvinceChina

This study aims to develop an analytical model based on the curve beam theory to capture the mechanical response of a multihelix cable considering the internal contact ***,a double-helix cable subjected to axial tension and torsion is analyzed,and both the line and point contacts between the neighboring wires and strands are considered via an equivalent homogenized ***,the proposed theoretical model is extended to a hierarchical multihelix cable with mutual contact displacements by constructing a recursive relationship between the high-and low-level multihelix *** global tensile stiffness and torsional stiffness of the double-helix cable are successfully *** results are validated by a finite element(FE)model,and are found to be consistent with the findings of previous *** is shown that the contact deformations in multihelix cables significantly affect their equivalent mechanical stiffness,and the contact displacements are remarkably enhanced as the helix angles *** study provides insights into the interwire/interstrand mutual contact effects on global and local responses.

关键词： wordshierarchical multihelix cable mutual contact effect mechanical response effective stiffness

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Stability analysis of intermittently jointed rock slopes based on the stepped failure mode

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Journal of Mountain Science 2024年第3期21卷 1019-1035页

作者： LI Dejian FU Junwen LI Hekai CHENG Xiao ZHAO Lianheng ZHANG Yingbin PENG Xinyan School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Institute for Disaster Management and Reconstruction College of Architecture&EnvironmentSichuan UniversityChengdu 610065China School of Civil Engineering Key Laboratory of Heavy-Haul Railway Engineering StructureMinistry of EducationHunan Provincial Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering StructureCentral South UniversityChangsha 410075China

In practical engineering,due to the noncontinuity characteristics of joints in rock slopes,in addition to plane failure,stepped sliding failure may occur for intermittently jointed rock *** for intermittently bedding jointed rock slopes,the correlation and difference in strength parameters between joints and rock bridges,along with the various failure modes and intermittency of rock bridges,contribute to the complexity of stepped failure modes and the unpredictability of failure *** on the upper-bound limit analysis method and multi-sliders step-path failure mode,considering the shear and tensile failure of rock bridges and the weakened relationship between the strength parameters of rock bridges and jointed surfaces,by introducing the modified M-C failure criterion and the formula for calculating the energy consumption of tensile failure of rock bridges,two failure mechanisms are constructed to obtain the safety factor(F_(s))of intermittently jointed rock *** sequential quadratic programming method is used to obtain the optimal upper-bound solution for F_(s).The influence of multiple key parameters(slope height H,horizontal distance L,Slope angleβ,shear strength parameters of the rock bridgeφr and cr,Dimensionless parameter u,weakening coefficients of the internal friction angle and cohesion between the rock bridges and joint surfaces Kφand Kc)on the stability analysis of intermittently jointed rock slopes under the shear failure mode of rock bridges as well as under the tensile failure mode is also *** reliability of the failure mechanisms is verified by comparative analysis with theoretical results,numerical results,and landslide cases,and the variation rules of F_(s)with each key parameter are *** results show that F_(s) varies linearly withφr and cr of the rock bridge and with K_(φ)and K_(c),whereas F_(s)changes nonlinearly with H and *** particular,with the increase in Kφand Kc,Fs increases by approximately 52.

关键词： Jointed rock slopes Stepped sliding failure Weakening characteristics Modified M‒C failure criterion

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Effects of Biowaste-Derived Hydrochar on Anaerobic Digestion:Insights into Hydrochar Characteristics

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Journal of Renewable Materials 2023年第10期11卷 3647-3657页

作者： Hongqiong Zhang Xu Wang Zhaojing Qian Buchun Si Kai Jin Tengfei Wang Key Laboratory of Agricultural Renewable Resource Utilization Technology College of EngineeringNortheast Agriculture UniversityHarbin150030China College of Engineering Northeast Agricultural UniversityHarbin150030China College of Food Science Northeast Agricultural UniversityHarbin150030China Laboratory of Environment-Enhancing Energy(E2E) Key Laboratory of Agricultural Engineering in Structure and EnvironmentMinistry of AgricultureCollege of Water Resources and Civil EngineeringChina Agricultural UniversityBeijing100083China Faculty of Geosciences and Environmental Engineering Southwest Jiao Tong UniversityChengdu611756China

Hydrochar prepared with four typical biowastes,pine wood,food waste,digested sewage sludge,and Chlorella were applied for the promotion of anaerobic *** gas production and substrate composition were analyzed associated with the hydrochar *** results suggested that Chlorella hydrochar(C-C)showed the highest cumulative yield of methane(approximately 345 mL)with high total organic carbon(TOC)removal efficiency and low volatile fatty acids(VAFs)***,food waste hydrochar(F-C)showed a poor effect on anaerobic digestion and aroused 1.4–1.6 g/L accumulation of VAFs,in which the toxic components may account for the low *** C-C and sludge hydrochar(S-C)may develop direct interspecific electron transport(DIET)to facilitate the generation of methane by both surface groups and conductivity of the body structure,unlike pinewood hydrochar(P-C),which mainly depended on the aromatic matrix structure of hydrochar *** work suggested that C-C can be the best candidate for the facilitation of anaerobic digestion,and N-containing biowaste like algae and lignocellulose like pine wood may establish different DIET pathways based on the physicochemical characteristics of hydrochar.

关键词： Biowaste hydrochar DIET anaerobic digestion methane

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Behavioural recognition model for laying hens based on skeletal feature points 11

Behavioural recognition model for laying hens based on skele...

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11th European Conference on Precision Livestock Farming

作者： Peng, Yin Siqi, Wei Qin, Tong Baoming, Li Yujia, Chen Yang, Wang College of Water Resources and Civil Engineering China Agricultural University Beijing100083 China Key Laboratory of Agricultural Engineering in Structure and Environment Ministry of Agriculture Beijing100083 China Beijing Engineering Research Center for Animal Healthy Environment Beijing100083 China

ISBN: (纸本)9791221067361

The behavioural expressions of poultry serve as vital indicators of health and welfare. In this study, an individual behaviour recognition model for laying hens was developed by analyzing the distribution characteristics of skeletal feature points. This model successfully categorized behaviours such as standing, preening, wing flap, and resting. Three experimental cages, each housing 10 laying hens at 0-20 wk of age, were established in the laboratory for the purpose of recording video data capturing the behavioural expressions of the flock. A dataset was compiled by manually selecting image frames representing each target behaviour, resulting in a total of 937 frames. We employed a deep convolutional neural network model to detect the 8 feature points on the hen's body. These continuously extracted key points were rendered as grayscale images and then fed into an improved 1D-CNN model, enabling classification based on the distribution characteristics of each feature point. The test error for the 8 feature points on the hen's body was 10.13 pixel. The improved 1D-CNN model achieved an overall classification accuracy of 86.02%. The classification accuracy for standing, preening, wing flap, and resting behaviours was 85.19%, 96.30%, 92.59%, and 84.31%, respectively. In summary, the individual behaviour recognition model for laying hens, based on skeletal feature points, served as an automated and non-invasive monitoring method. © 2024 11th European Conference on Precision Livestock Farming. All rights reserved.

关键词： Deep neural networks

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Research on performance optimization of virtual data space across WAN

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Frontiers of Computer Science 2024年第6期18卷 167-187页

作者： Jiantong HUO Zhisheng HUO Limin XIAO Zhenxue HE State Key Laboratory of Software Development Environment Beihang UniversityBeijing 100191China School of Computer Science and Engineering Beihang UniversityBeijing 100191China High Performance Computing Center Beihang UniversityBeijing 100191China Hebei Key Laboratory of Agricultural Big Data Hebei Agricultural UniversityBaoding 071001China

For the high-performance computing in a WAN environment,the geographical locations of national supercomputing centers are scattered and the network topology is complex,so it is difficult to form a unified view of *** aggregate the widely dispersed storage resources of national supercomputing centers in China,we have previously proposed a global virtual data space named GVDS in the project of“High Performance Computing Virtual Data Space”,a part of the National key Research and Development Program of *** GVDS enables large-scale applications of the high-performance computing to run efficiently across ***,the applications running on the GVDS are often data-intensive,requiring large amounts of data from multiple supercomputing centers across *** this regard,the GVDS suffers from performance bottlenecks in data migration and access across *** solve the above-mentioned problem,this paper proposes a performance optimization framework of GVDS including the multitask-oriented data migration method and the request access-aware IO proxy resource allocation *** a WAN environment,the framework proposed in this paper can make an efficient migration decision based on the amount of migrated data and the number of multiple data sources,guaranteeing lower average migration latency when multiple data migration tasks are running in *** addition,it can ensure that the thread resource of the IO proxy node is fairly allocated among different types of requests(the IO proxy is a module of GVDS),so as to improve the application’s performance across *** experimental results show that the framework can effectively reduce the average data access delay of GVDS while improving the performance of the application greatly.

关键词： storage aggregation across WANs large-scale applications GVDS data migration allocation of IO proxy resource

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Waste bio-tar based N-doped porous carbon for supercapacitors under dual activation:performance,mechanism,and assessment

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Biochar 2023年第1期5卷 1559-1573页

作者： Jixiu Jia Yuxuan Sun Zhidan Liu Ziyun Liu Lili Huo Kang Kang Yanan Zhao Lixin Zhao Teng Xie Maojiong Cao Zonglu Yao Key Laboratory of Low-Carbon Green Agriculture in North China Ministry of Agriculture and Rural Affairs P.R.China.Institute of Environment and Sustainable Development in AgricultureCAASBeijing 100081China Laboratory of Environment-Enhancing Energy(E2E) Key Laboratory of Agricultural Engineering in Structure and EnvironmentMinistry of College of Water Resources and Civil EngineeringChina Agricultural UniversityBeijing 100083China Biorefining Research Institute(BRI)and Department of Chemical Engineering Lakehead UniversityThunder BayON P7B 5E1Canada

Bio-tar extra-produced from biomass pyrolysis is prone to pose a threat to environment and human health.A novel N-doped porous electrode from bio-tar was produced under dual-activation of urea and KOH in this *** dual-activation played significant roles in N-functional group and micro-mesoporous structure,which resulted in the carbon material with the highest of nitrogen content(4.08%)and the special surface area(1298.26 m^(2)·g^(−1)).Specifically,the potential mechanisms of pore formation and N-doping in the one-pot dual-activation strategy were also proposed as a consequence,the one-pot dual-activated carbon material displayed excellent electrochemical performance with the highest capacitance of 309.5 F·g^(−1) at 0.5 A·g^(−1),and the unipolar specific capacitance remained with cyclic characteristics of 80.1%after 10,000 cycles in two-electrode symmetric ***,the one-pot dual-activation strategy could create a profit of$1.64-$2.38 per kilogram of bio-tar processed without considering the initial investment and labor costs,which provides new perspectives for the utilization of waste bio-tar.

关键词： Bio-tar Dual activation Techno-economic assessment Porous carbon N-doping Supercapacitors

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Pilot Combustion Characteristics of RP-3 Kerosene in a Trapped-Vortex Cavity with Radial Bluff-Body Flameholder

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Journal of Thermal Science 2023年第1期32卷 468-487页

作者： ZHANG Yuxuan HE Xiaomin College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Aero-Engine Thermal Environment and Structure Key Laboratory of Ministry of Industry and Information TechnologyNanjing 210016China

The structure of the trapped-vortex cavity and radial flameholder can maintain stable combustion under severe conditions,such as sub-atmospheric pressure and high inlet *** article reports a complete study of combustion characteristics for this *** flow field of the physical model was obtained by numerical *** pilot combustion characteristics,including the combustion process,combustion efficiency,and wall temperature distribution,were studied by *** pilot combustion can be divided into three modes under different fuel flow rates and inlet ***“cavity maintained(CM)”mode,pilot flame exists at both sides of the cavity zone,rotating with the main ***“cavity-flameholder maintained(CFM)”mode,the combustion process occurs both inside the cavity and behind the *** in“flameholder maintained(FM)”mode,the cavity will quench,and the combustion is maintained by the radial flameholder *** to the difference in the flow field,the flame pattern and propagation direction vary under different combustion *** combustion efficiency,influenced by combustion modes,shows an increase-decrease-increase *** wall temperature distribution is also affected;the cavity wall temperature decreases under large fuel flux while the temperature of the burner-back plate continues to rise to a maximum value.

关键词： cavity spray combustion flame propagation combustion efficiency wall temperature

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Fe/BC co-conditioners with environmental and economic benefits on composting:reduced NH_(3)emissions and improved fertilizer quality

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Biochar 2024年第1期6卷 50-65页

作者： Jixiang Wang Huifang Xie Jun Wu Weijiang He Xi Zhang Junxia Huang Yanfang Feng Lihong Xue Key Laboratory of Agro-Environment in Downstream of Yangtze Plain Ministry of Agriculture and Rural AffairsInstitute of Agricultural Resources and EnvironmentJiangsu Academy of Agricultural SciencesNanjing 210014China. Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing 210094China. Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes Ministry of EducationCollege of EnvironmentHohai UniversityNanjing 210098China.

The significant volatilization of NH_(3)during aerobic composting causes nitrogen(N)losses and environmental *** iron(Fe)and biochar(BC)can influence the N conversion process in *** application can delay the maturation of materials,while biochar can enhance the quality of organic *** combination of these two conditioners may help decrease NH_(3)emissions and improve organic fertilizer ***,this study investigates the effects of different doses of FeCl_(3)and BC on NH_(3)emissions and organic fertilizer quality during *** results demonstrated that Fe/BC co-conditioners reduced the accumulation of NH_(3)emissions during composting by 11.1-48.2%,increased the total nutrient content by 0.6-15.3%,and enhanced economic and environmental benefits by 0.1-23.6$t^(−1).At the high-temperature stage of composting,Fe/BC co-conditioners decreased the pH by 0.3-1.2,but there was no significant difference compared to the control at the end of composting,and they did not affect compost *** structural equation model analysis suggested that the reduction in NH_(3)emis-sions was related to ammonia-oxidizing bacteria(AOB),NH_(4)^(+)-N,and total nitrogen(TN).As a result,the Fe/BC co-conditioners reduced NH_(3)emissions by lowering the pH at the beginning of composting and increasing the content of NH_(4)^(+)-*** study concludes that Fe/BC co-conditioners could complement each other to significantly reduce NH_(3)emissions and improve the quality of organic fertilizers.

关键词： Aerobic composting Biochar Organic fertilizer NH_(3)emissions FeCl_(3)

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