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Aerial refueling scheduling of multi-receiver and multi-tanker under spatial-temporal constraints for forest firefighting

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Chinese Journal of Aeronautics 2024年第5期37卷 71-91,I0001页

作者： Jing HUANG Jiaqi XING Jinrui REN Quan QUAN youmin ZHANG Department of Information and Control Engineering Xi’an University of TechnologyXi’an 710048China Jiujiang Measuring Test Technology Research Institute Jiujiang 332000China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China School of Automation Xi’an University of Posts&TelecommunicationsShaanxiXi’an 710121China Department of Mechanical Industrial and Aerospace EngineeringConcordia UniversityMontreal H3G 1M8Canada

Forest fires pose a significant threat to human life and property,so the utilization of unmanned aircraft systems provides new ways for forest *** the constrained load capacities of these aircraft,aerial refueling becomes crucial to extend their operational time and *** order to address the complexities of firefighting missions involving multi-receiver and multi-tanker deployed from various airports,first,a fuel consumption calculation model for aerial refueling scheduling is established based on the receiver ***,two distinct methods,including an integrated one and a decomposed one,are designed to address the challenges of establishing refueling airspace and allocating tasks for *** methods aim to optimize total fuel consumption of the receivers and tankers within the aerial refueling scheduling *** optimization problem is established as nonlinear optimization models along with *** integrated method seamlessly combines refueling rendezvous point scheduling and tanker task allocation into unified *** has a complete solution space and excels in optimizing total fuel *** decomposed method,through the separation of rendezvous point scheduling and task allocation,achieves a reduced computational ***,this comes at the cost of sacrificing optimality by excluding specific feasible ***,numerical simulations are carried out to verify the feasibility and effectiveness of the proposed *** simulations yield insights crucial for the practical engineering application of both the integrated and decomposed methods in real-world *** comprehensive approach aims to enhance the efficiency of forest firefighting operations,mitigating the risks posed by forest fires to human life and property.

关键词： Aerial refueling Scheduling Planning Spatial-temporal constraint Firefighting

WeldNet:A voxel-based deep learning network for point cloud annular weld seam detection

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Science China(Technological Sciences) 2024年第4期67卷 1215-1225页

作者： WANG Hui RONG youmin XU JiaJun XIANG SongMing PENG YiFan HUANG Yu State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

Weld seam detection is an important part of automated *** present,few studies have been conducted on annular weld seams,and a lot of defects exist in the point cloud model of the tube sheet obtained by RGB-D cameras and photography *** at the above problems,this paper proposed an annular weld seam detection network named WeldNet where a voxel feature encoding layer was adaptively improved for annular weld seams,the sparse convolutional network and region proposal network(RPN)were used to detect annular weld seam position,and an annular weld seam detection loss function was ***,an annular weld seam dataset was established to train the *** with the random sampling consistency(RANSAC)method,WeldNet has a higher detection accuracy,as well as a higher detection success rate which has increased by 23%.Compared with U-Net,WeldNet has been proven to achieve a better detection result,and the intersection over the union of the weld seam detection is improved by 17.8%.

关键词： deep learning point cloud weld seam detection welding annular weld seam

Transplant outcomes of 100 cases of living-donor ABO-incompatible kidney transplantation

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Chinese Medical Journal 2022年第19期135卷 2303-2310页

作者： Saifu Yin Qiling Tan youmin yang Fan Zhang Turun Song Yu Fan Zhongli Huang Tao Lin Xianding Wang Department of Urology Institute of UrologyOrgan Transplantation CenterWest China HospitalSichuan UniversityChengduSichuan 610041China The Third Comprehensive Care Unit West China HospitalWest China School of NursingSichuan UniversityChengduSichuan 610041China.

Background:Although ABO-incompatible(ABOi)kidney transplantation(KT)has been performed successfully,a standard preconditioning regimen has not been *** on the initial antidonor ABO antibody titers,an individualized preconditioning regimen is developed,and this study explored the efficacy and safety of the ***:From September 1,2014,to September 1,2020,we performed 1668 consecutive living-donor KTs,including 100 ABOi and 1568 ABO-compatible(ABOc)*** KT recipients(KTRs)with a lower antibody titer(≤1:8)were administered oral immunosuppressive drugs(OIs)before KT,while patients with a medium titer(1:16)received OIs plus antibody-removal therapy(plasma exchange/double-filtration plasmapheresis),patients with a higher titer(≥1:32)were in addition received rituximab(Rit).Competing risk analyses were conducted to estimate the cumulative incidence of infection,acute rejection(AR),graft loss,and patient ***:After propensity score analyses,100 ABOi KTRs and 200 matched ABOc KTRs were *** were no significant differences in graft and patient survival between the ABOi and ABOc groups(P=0.787,P=0.386,respectively).After using the individualized preconditioning regimen,ABOi KTRs showed a similar cumulative incidence of AR(10.0%vs.10.5%,P=0.346).Among the ABOi KTRs,the Rit-free group had a similar cumulative incidence of AR(P=0.714)compared to that of the Rittreated *** competing risk analyses revealed that a Rit-free regimen reduced the risk of infection(HR:0.31;95%CI:0.12–0.78,P=0.013).Notably,antibody titer rebound was more common in ABOi KTRs receiving a Rit-free preconditioning regimen(P=0.013)than those receiving *** KTRs with antibody titer rebound had a 2.72-fold risk of AR(HR:2.72,95%CI:1.01–7.31,P=0.048).ABOi KTRs had similar serum creatinine and estimated glomerular filtration rate compared to those of ABOc KTRs after the first ***:An individualized preconditioning regimen can achieve comp

关键词： ABO blood-group system Kidney transplantation Rituximab Immunologic desensitization

Research on the Soil Carbon Storage of Alpine Grassland under Different Land Uses in Qinghai-Tibet Plateau

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Journal of Agricultural Science and Technology(A) 2013年第2期3卷 99-104页

作者： Tao Li Lei Ji Tao Liu Zhongqi Song Shujing yang youmin Gan Department of Grassland Science College of Animal Science and Technology Sichuan Agricultural University Sichuan Ya 'an625014 China

In this article, we mainly analysis the soil carbon storage of the alpine grassland under different land uses in Qinghai-Tibet Plateau. The samples of this investigation include six experimental fields which are fenced mowing grassland, artificial grassland, winter and spring grazing meadowland, summer and autumn mild grazing land, summer and autumn moderate grazing pasture and summer and autumn severe grazing land and seven soil layers included 0 cm-5 cm, 5 cm-10 cm, 10 cm-20 cm, 20 cm-30 cm, 30 cm-50 cm, 50 cm-70 cm and 70 cm-100 cm. The results show that the soil carbon storage in different soil layers will gradually reduce and the difference was remarkable （P 〈 0.05）. What is more, the soil carbon storage of alpine grassland under different land uses has following sequence： winter and spring grazing grassland 〉 summer and autumn mild grazing land 〉 artificial grassland 〉 summer and autumn moderate grazing meadowland 〉 summer and autumn severe grazing pasture 〉 fenced mowing meadow, and the significant difference between them is remarkable （P 〈 0.05）.

关键词： Qinghai-Tibet Plateau alpine grassland soil carbon storage.

Influence of syngas components and ash particles on the radiative heat transfer in a radiant syngas cooler

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Chinese Journal of Chemical Engineering 2024年第4期68卷 203-215页

作者： Chen Han youmin Situ Huaxing Zhu Jianliang Xu Zhenghua Dai Guangsuo Yu Haifeng Liu National Energy Coal Gasification Technology Research and Development Center East China University of Science and TechnologyShanghai 200237China Shanghai Engineering Research Center of Coal Gasification East China University of Science and TechnologyShanghai 200237China

Radiant syngas cooler(RSC)is widely used as a waste heat recovery equipment in industrial *** this work,an RSC with radiation screens is established and the impact of gaseous radiative property models,gas components,and ash particles on heat transfer is investigated by the numerical simulation *** the syngas components and the pressure environment of the RSC,a modified weighted-sum-of-gray-gases model was *** modified model shows high accuracy in *** computational fluid dynamics simulation,the calculated steam production is only 0.63%in error with the industrial *** with Smith's model,the temperature decay along the axial direction calculated by the modified model is *** components are of great significance to heat recovery capacity,especially when the absorbing gas fraction is less than 10%.After considering the influence of particles,the outlet temperature and the proportion of radiative heat transfer are less affected,but the difference in steam output reaches 2.7 t·h^(-1).The particle deposition on the wall greatly reduces the heat recovery performance of an RSC.

关键词： Radiant syngas cooler Weighted-sum-of-gray-gases model Numerical simulation Particle radiation

Tuning synergy between nickel and iron in Ruddlesden-Popper perovskites through controllable crystal dimensionalities towards enhanced oxygenevolving activity and stability

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Carbon Energy 2024年第6期6卷 113-123页

作者： Haijuan Zhang Daqin Guan Yuxing Gu Hengyue Xu Chunchang Wang Zongping Shao youmin Guo School of Materials Science and Technology Anhui UniversityHefeiAnhuiChina Department of Building and Real Estate The Hong Kong Polytechnic UniversityHung HomHong KongChina WA School of Mines:Minerals Energy and Chemical EngineeringCurtin UniversityPerthWestern AustraliaAustralia State Key Laboratory of Materials-Oriented Chemical Engineering Nanjing Tech UniversityNanjingJiangsuChina Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhenGuangdongChina

Ni-Fe-based oxides are among the most promising catalysts developed to date for the bottleneck oxygen evolution reaction(OER)in water ***,understanding and mastering the synergy of Ni and Fe remain ***,we report that the synergy between Ni and Fe can be tailored by crystal dimensionality of Ni,Fe-contained Ruddlesden-Popper(RP)-type perovskites(La_(0.125)Sr_(0.875))n+1(Ni_(0.25)Fe_(0.75))nO3n+1(n=1,2,3),where the material with n=3 shows the best OER performance in alkaline *** X-ray absorption spectroscopy spectra before and after OER reveal that the material with n=3 shows enhanced Ni/Fe-O covalency to boost the electron transfer as compared to those with n=1 and n=*** experimental investigations demonstrate that the Fe ion is the active site and the Ni ion is the stable site in this system,where such unique synergy reaches the optimum at n=***,as n increases,the proportion of unstable rock-salt layers accordingly decreases and the leaching of ions(especially Sr^(2+))into the electrolyte is suppressed,which induces a decrease in the leaching of active Fe ions,ultimately leading to enhanced *** work provides a new avenue for rational catalyst design through the dimensional strategy.

关键词： crystal dimensionalities oxygen evolution reaction Ruddlesden-Popper perovskites synergy

Ultrafast laser-chemical modification hybrid fabrication of hydrostatic bearings with a superhydrophobicity solid-liquid interface

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Science China(Technological Sciences) 2024年第3期67卷 696-708页

作者： GUO MingHui RONG youmin HUANG Yu FENG XiaoLin HU HaiDong WU CongYi ZHANG GuoJun State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and Technology Wuhan 430074China School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China Faculty of Engineering and Life Sciences Universiti Selangor Bestari JayaSelangor 45600Malaysia

Oil film vortex severely reduces the stability of hydrostatic bearings. A solid-liquid interface with drag and slip properties can weaken the oil film vortex of the bearing. Here, a combined picosecond laser ablation and chemical modification method is proposed to prepare surfaces with microbulge array structure on 6061 aluminum alloy substrates. Because of the low surface energy of the perfluorododecyltriethoxysilane modification and the bulge geometry of the microbulge array structure, the surface shows excellent superhydrophobicity. The optimum contact angle in air for water is 164°, and that for oil is 139°. Two surfaces with “lotus-leaf effect” and “rose-petal effect” were obtained by controlling the processing parameters. The drag reduction properties of superhydrophobic surfaces were systematically investigated with slip lengths of 22.26 and 36.25 μm for deionized water and VG5 lubricant, respectively. In addition, the superhydrophobic surface exhibits excellent mechanical durability and thermal stability. The proposed method provides a new idea for vortex suppression in hydrostatic bearings and improves the stability of bearings in high-speed operation.

关键词： superhydrophobicity surface ultrafast laser drag reduction solid-liquid interface microbulge array structure

The Research on Carbon Accumulation of Grassland Ecological System in China

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Journal of Life Sciences 2012年第5期6卷 563-569页

作者： Tao Li Lei Ji Jianrong Tan Tao Liu Zhongqi Song Shujing yang youmin Gan College of Animal Science and Technology Sichuan Agricultural University Ya 'an 625014 Sichuan China

This article mainly introduced the research progress of the carbon accumulation on grassland ecological system, which is under the condition of the carbon cycle and the climate change in China. And in carbon cycle and the carbon storage on the terrestrial ecosystem, the author also analyzed the status and functions of the Chinese grassland ecological system. Based on the evaluation of the primary productivity, soil organic carbon and dry falling objects, herding utilization, the grass reclamation and other factors that affect carbon accumulation on grassland ecological system, the author then put forward the primal problems and the prospect of the research on China＇s carbon accumulation of grassland ecological system. The future of carbon stock volume in grassland ecosystem in China has great potential, the fixed carbon content is about 152 Tg/a, far more than the United States, Canada, Russia and other countries.

关键词： Grassland ecosystem carbon cycle carbon accumulation China.

Vibration properties of Paulownia wood for Ruan sound quality using machine learning methods

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Journal of Forestry Research 2024年第5期35卷 216-222页

作者： yang yang College of Art and Design Harbin UniversityHarbin 150076People’s Republic of China College of Mechanical and Electrical Engineering Northeast Forestry UniversityHarbin 150040People’s Republic of China

As an important material for manufacturing resonant components of musical instruments,Paulownia has an important influence on the sound quality of *** this paper,a model for evaluating the sound quality of Ruan based on the vibration characteristics of wood is developed using machine learning ***,the selection of materials for Ruan manufacturing relies primarily on manually weighing,observing,striking,and listening by the instrument *** in scientific theory have hindered the quality of the finished *** this study,nine Ruans were manufactured,and a prediction model of Ruan sound quality was proposed based on the raw material information of *** of a total of 180 data sets,145 and 45 sets were chosen for training and validation,*** this paper,typical correlation analysis was used to determine the correlation between two single indicators in two adjacent pairwise combinations of the measured objects in each stage of the production process in *** vibra-tion characteristics of the wood were tested,and a model for predicting the evaluation of Ruan’s acoustic qualities was developed by measuring the vibration characteristics of the resonating plate *** acoustic quality of the Ruan sound board wood was evaluated and predicted using machine learning model generalized regression neural *** results show that the prediction of Ruan sound quality can be achieved using Matlab simulation based on the vibration characteristics of the soundboard *** the model-predicted values were compared with the tradi-tional predicted results,it was found that the generalized regression neural network had good performance,achieving an accuracy of 93.8%which was highly consistent with the experimental *** was concluded that the model can accurately predict the acoustic quality of the Ruan based on the vibration performance of the soundboards.

关键词： Sound quality Wood vibration performance Paulownia wood Machine learning methods