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Biomedical and Environmental Sciences 2006年第3期19卷 192-196页

作者： jing kang jian-long wang Laboratory of Environmental Technology INET Tsinghua University Beijing lO0084 China

Objective To investigate the effect of chemical oxygen demand （COD） concentrations on the anaerobic ammonium oxidation （ANAMMOX）. Methods An Expanded Granular Sludge Bed （EGSB） reactor was used to cultivate the granular sludge and to perform the ANAMMOX reaction in the bench scale experiment. NH4^＋-N and NO2^--N were measured by using colorimetric method. NO3^＋-N was analyzed by using the UV spectrophotometric method. COD measurement was based on digestion with potassium dichromate in concentrated sulphuric acid. Results When the COD concentrations in the reactors were 0 mg/L, 200 mg/L, 350 mg/L, and 550 mg/L, respectively, the NH4^＋-N removal efficiency was 12.5%, 14.2%, 14.3%, and 23.7%; the removal amount of NO2-N was almost the same; the nitrate removal efficiency was 16.8%, 94.5%, 86.6%, and 84.2% and TN removal efficiency was 16.3%, 50.7%, 46.9%, and 50.4%, moreover, the COD removal efficiency was 85%, 65.7%, and 60%; the COD removal rate was 27.42, 61.88, and 97.8 mg COD/（h·L）. Conclusion COD concentrations have a significant influence on anaerobic ammonium oxidation by granular sludge.

关键词： Anaerobic ammonium oxidation Granular sludge Nitrogen removal COD

Steel-refractory reactions in lanthanum-,cerium-,and ytrium-added steels

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Journal of Iron and Steel Research International 2024年第6期31卷 1473-1485页

作者： jian kang Hong-po wang Yu wang College of Materials Science and Engineering Chongqing UniversityChongqing 400044China The State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China

A systematic experimental study was conducted on the similarities and differences in the reactions between commonly used rare earth elements(REEs)and frequently used refractories in the steelmaking *** results indicate that the reaction behaviors of La,Ce,and Y with MgO,Al_(2)O_(3),and MgO·Al_(2)O_(3) crucibles differed *** consumption rates of La,Ce,and Y in the molten steel were in descending order of La>Ce>Y for smelting with all three kinds of *** the REEs reacted with the crucible,the contents of Mg and Al showed a trend of first increasing and then *** laboratory-scale smelting conditions,the reactions related to REEs were dominated by steel-crucible reactions,and the contact area between the unit mass of molten steel and refractory materials mainly determined the consumption rates of ***-and Ce-crucible reactions generated loose and porous reaction interfaces;however,Y-crucible reactions generated a dense Y_(2)O_(3) layer,dramatically suppressing the consumption rate of *** calculation indicated that the reactions between rare earth and different refractory materials were first-order *** crucible materials significantly affected the product type and morphology of the steel-crucible reaction interfaces,thereby influencing the consumption rate of *** reactions between REEs and refractories must be seriously considered,especially for small-scale smelting.

关键词： Rare earth Inclusion Refractory Thermodynamics Dynamics

Covariate-Assisted Matrix Completion with Multiple Structural Breaks

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Journal of Systems Science & Complexity 2024年第2期37卷 692-728页

作者： MENG jing FENG long ZOU Changliang wang Zhaojun School of Statistics and Data Science KLMDASRLEBPSand LPMCNankai UniversityTianjin 300071China

In matrix completion,additional covariates often provide valuable information for completing the unobserved entries of a high-dimensional low-rank matrix *** this paper,the authors consider the matrix recovery problem when there are multiple structural breaks in the coefficient matrix β under the column-space-decomposition model A=Xβ+B.A cumulative sum(CUSUM)statistic is constructed based on the penalized estimation of β.Then the CUSUM is incorporated into the Wild Binary Segmentation(WBS)algorithm to consistently estimate the location of ***,a nearly-optimal recovery of A is *** findings are further corroborated via numerical experiments and a real-data application.

关键词： Additional covariates matrix completion multiple structural breaks wild Binary Segmentation

In situ regulating intimately connected heterostructure by decomposition of solid solution oxides toward high-efficient water oxidation

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Rare Metals 2024年第4期43卷 1557-1569页

作者： Shao-Fei Zhang Xiao-Lu Yin Jin wang jian-Li kang Tian-Tian Li Jin-Feng Sun Yong-Qiang Meng jian-jiang wang Dian-long wang Kai-Qiang Qin Hebei Key Laboratory of Flexible Functional Materials/Hebei Key Laboratory of Material Near-Net Forming Technology School of Materials Science and EngineeringHebei University of Science and TechnologyShijiazhuang050018China Key Laboratory of Advanced Ceramics and Machining Technology/Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin300072China Electrochemical Engine Center Department of Mechanical EngineeringPennsylvania State UniversityUniversity ParkPA16802USA

Heterogeneous interfaces produced by interdomain interactions on a nanoscale performs a crucial role in boosting the properties of an electrocatalyst toward oxygen evolution reaction(OER)***,a series of dual-phase electrodes with intimately connected heterointerfaces are prepared by in situ decomposing solid solution oxide of Ni_(x)Co_(y)Fe_(100-x-y)O,which grew on Ni foam massively via an ultrafast combustion ***,with high-reaction kinetics caused by the reduction treatment at 450℃,the less electronegative Fe and Co are more oxyphilic than Ni,which facilitated their co-exsolution and formation of CoFe_2O_4/NiO oxide with enriched oxygen *** from the nanoporous framework,heterojunction structure,and oxygen defects,the self-supporting electrodes present rapid charge/mass transmission and provide abundant active sites for *** optimized sample(R-SNCF4.5)shows low overpotentials of 226 and 324 mV at 10 and100 mA·cm^(-2),a small Tafel slope(46.7 mV·dec^(-1)),and excellent *** assembled R-SNCF4.5//Pt/C/NF electrolyzer demonstrates continuous electrolysis over 50 h at a current density of 10 mA·cm^(-2),under 1.51 *** functional theory(DFT)calculations verify that the strong electronic modulation plays a critical part in the CoFe_2O_4/NiO hybrid by lowering the energy barriers for the ratedetermining steps,and Fe sites are the most active OER sites.

关键词： Rapid combustion Decomposition of solid solution oxide Dual-phase heterostructure Oxygen evolution reaction Theoretical calculation

Exhaust hood performance and its improvement technologies in industrial buildings:A literatu rereview

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Building Simulation 2024年第1期17卷 23-40页

作者： jing Zhang jian wang Jun Gao Weimin Zhang Architectural Engineering Institute Jinhua PolytechnicJinhua 321017China Institute of HVAC Engineering Schoolof Mechanical EngineeringTongji UniversityShanghai 200092China Tongji Architectural Design(Group)Co .LtdShanghai 200092China

The pollutant control performance of exhaust hoods plays a crucial role in the indoor air quality and energy consumption of ventilation systems in industrial *** better understand the impact of local ventilation on the industrial indoor environment,this paper presents a literature review of exhaust hood performance and its improvement *** create an index for evaluating the performance of exhaust hoods,the capture velocity,capture efficiency,flow ratio of pollutant emissions and exhaust airflow and energy consumption are first introduced.A number of factors affecting exhaust hood performance are assessed such as hood type,hood opening size,exhaust rate,installation distance,pollution source emission and environmental *** to structural improvement methods,the use of active airflow is a more effective way to improve the exhaust hood *** most commonly used methods for determining the exhaust rate are the controlled speed method and the flow ratio *** use of an exhaust hood with an appropriate exhaust rate and jet parameters(for an active air-assisted hood)can effectively improve the pollutant control performance and reduce the energy consumption that would be wasted on the redundant exhaust *** more information focused on exhaust hood performance,this work suggests more effective strategies for improving indoor air quality and reducing energy consumption in industrial buildings.

关键词： industrial ventilation exhaust hood capture efficiency exhaust rate performance improvement

Autonomous multi-drone racing method based on deep reinforcement learning

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Science China(Information Sciences) 2024年第8期67卷 35-48页

作者： Yu kang jian DI Ming LI Yunbo ZHAO Yuhui wang Department of Automation University of Science and Technology of China Institute of Advanced Technology University of Science and Technology of China Institute of Artificial Intelligence Hefei Comprehensive National Science Center College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Racing drones have attracted increasing attention due to their remarkable high speed and excellent maneuverability. However, autonomous multi-drone racing is quite difficult since it requires quick and agile flight in intricate surroundings and rich drone interaction. To address these issues, we propose a novel autonomous multi-drone racing method based on deep reinforcement learning. A new set of reward functions is proposed to make racing drones learn the racing skills of human experts. Unlike previous methods that required global information about tracks and track boundary constraints, the proposed method requires only limited localized track information within the range of its own onboard sensors. Further, the dynamic response characteristics of racing drones are incorporated into the training environment, so that the proposed method is more in line with the requirements of real drone racing scenarios. In addition, our method has a low computational cost and can meet the requirements of real-time racing. Finally, the effectiveness and superiority of the proposed method are verified by extensive comparison with the state-of-the-art methods in a series of simulations and real-world experiments.

关键词： racing drone autonomous multi-drone racing sim-to-real deep reinforcement learning Markov game

Application of Isogeometric Analysis Method in Three-Dimensional Gear Contact Analysis

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 817-846页

作者： long Chen Yan Yu Yanpeng Shang Zhonghou wang jing Zhang School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai200093China Zhejiang Fine-Motion Robot Joint Technology Co. Ltd.Taizhou317600China

Gears are pivotal in mechanical drives,and gear contact analysis is a typically difficult problem to *** isogeometric analysis(IGA)methods have developed new ideas to solve this *** this paper,a threedimensional body parametric gear model of IGA is established,and a theoretical formula is derived to realize single-tooth contact *** were benchmarked against those obtained from commercial software utilizing the finite element analysis(FEA)method to validate the accuracy of our *** findings indicate that the IGA-based contact algorithmsuccessfullymet theHertz contact *** juxtaposed with the FEA approach,the IGAmethod demonstrated fewer node degrees of freedomand reduced computational units,all whilemaintaining comparable ***,the IGA method appeared to exhibit consistency in analysis accuracy irrespective of computational unit density,and also significantlymitigated non-physical oscillations in contact stress across the tooth *** underscores the prowess of IGA in contact *** conclusion,IGA emerges as a potent tool for addressing contact analysis challenges and holds significant promise for 3D gear modeling,simulation,and optimization of various mechanical components.

关键词： Contact analysis involute gear isogeometric analysis finite element analysis

Microstructure and texture evolution of Cu-Cr-Co-Ti alloys during the two-stage cryorolling

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Rare Metals 2024年第9期43卷 4535-4547页

作者： Jia-Jun Zhang long-jian Li Zhi-Feng Liu Zong-Ning Chen En-Yu Guo Hui-Jun kang Ren-Geng Li Tong-Min wang Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China Center of Hyper-Gravity Experimental and Interdisciplinary Research Zhejiang UniversityHangzhou 310058China Ningbo Institute of Dalian University of Technology Ningbo 315000China Key Laboratory for Light-Weight Materials Nanjing Tech UniversityNanjing 210009China

This study entailed an investigation of the mechanical properties,microstructural and texture orientation evolutions of Cu-Cr-Co-Ti alloys prepared via twostage cryorolling and intermediate aging *** this end,X-ray diffraction and electron backscatter diffraction were *** results indicate that the two-stage cryorolling and intermediate aging treatments led to the development of profuse twin bundles and significantly enhanced the mechanical *** initial cryorolling led to coplanar slip and developed a strong Y({111})orientation,accelerating the formation of Goss({011})orientation and a Brass-type *** intermediate aging treatment relieved the restriction on dislocation slip and reoriented the grains toward the Copper({112})and Z({111})*** Z orientation,with a relatively high volume fraction,dominated the *** cryorolling intensified twinning and shear banding,transforming the Copper-type shear bands into Brass-type shear bands with rhomboidal prism *** areas inside the Brasstype shear bands exhibited a Y orientation,and the areas outside the shear bands exhibited a stable Brass-type *** evident decrease in the weighted Schmid factors demonstrated that the two-stage cryorolling and intermediate aging treatment can modify the texture evolution and aid the design of high-performance Cu alloys.

关键词： Copper alloys Two-stage cryorolling Macrotexture evolution Electron backscatter diffraction Schmid factor

Milestone progress of the HEPS booster commissioning

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Nuclear Science and Techniques 2024年第1期35卷 170-177页

作者： Yue-Mei Peng jian-She Cao Jin-Hui Chen Hai-Yi Dong Ping He Yi Jiao Ling kang Wen kang jian Li jing-Yi Li Guo-Ping Lin Fang Liu Feng-Li long Cai Meng Xin Qi Hua-Min Qu Yan-Feng Sui Sheng wang Gang Xu Qiang Ye jing Zhang Pei Zhang Wei-Min Pan Key Laboratory of Particle Acceleration Physics and Technology Institute of High Energy PhysicsChinese Academy of Sciences19B Yuquan RoadShijingshan DistrictBeijing 100049China University of the Chinese Academy of Sciences 19A Yuquan RoadShijingshan DistrictBeijing 100049China

The high-energy photon source(HEPS)is the first fourth-generation synchrotron light source facility in *** HEPS injector consists of a linear accelerator(Linac)and a full energy *** booster captures the electron beam from the Linac and increases its energy to the value required for the storage *** full-energy beam could be injected to the storage ring directly or after“high-energy accumulation.”On November 17,2023,the key booster parameters successfully reached their corresponding target *** milestone results were achieved based on numerous contributions,including nearly a decade of physical design,years of equipment development and installation,and months of beam *** measured at the extraction energy of 6 GeV,the averaged beam current and emittance reached 8.57 mA with 5 bunches and 30.37 nm rad with a single-bunch charge of 5.58 nC,compared with the corresponding target values of 6.6 mA and 35 nm rad,*** paper presents the physical design,equipment development,installation,and commissioning process of the HEPS booster.

关键词： High energy photon source Booster Beam commissioning

Meiotic transcriptional reprogramming mediated by cell-cell communications in humans and mice revealed by scATACseq and scRNA-seq

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Zoological Research 2024年第3期45卷 601-616页

作者： Hai-Quan wang Xiao-long Wu jing Zhang Si-Ting wang Yong-Juan Sang kang Li Chao-Fan Yang Fei Sun Chao-Jun Li State Key Laboratory of Reproductive Medicine and Offspring Health Center for Global HealthSchool of Public HealthNanjing Medical UniversityNanjingJiangsu 211166China Medical School Nanjing UniversityNanjingJiangsu 210093China Zhejiang University School of Medicine HangzhouZhejiang 310016China Department of Urology and Andrology Sir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouZhejiang 310000China Model Animal Research Center of Medical School Nanjing UniversityNanjingNanjingJiangsu 210093China Liangzhu Laboratory Zhejiang UniversityHangzhouZhejiang 311121China

Meiosis is a highly complex process significantly influenced by transcriptional ***,studies on the mechanisms that govern transcriptomic changes during meiosis,especially in prophase I,are ***,we performed single-cell ATAC-seq of human testis tissues and observed reprogramming during the transition from zygotene to pachytene *** event,conserved in mice,involved the deactivation of genes associated with meiosis after reprogramming and the activation of those related to spermatogenesis before their functional ***,we identified 282 transcriptional regulators(TRs)that underwent activation or deactivation subsequent to this *** suggested that physical contact signals from Sertoli cells may regulate these TRs in spermatocytes,while secreted ENHO signals may alter metabolic patterns in these *** results further indicated that defective transcriptional reprogramming may be associated with non-obstructive azoospermia(NOA).This study revealed the importance of both physical contact and secreted signals between Sertoli cells and germ cells in meiotic progression.

关键词： Single-cell RNA-seq Single-cell ATAC-seq Spermatogenesis Meiosis Transcriptional reprogramming Cell-cell communication