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星载光子计数激光测距雷达的实时去噪方法

红外与毫米波学报 2024年第2期43卷 242-253页

作者：谭崇涛于文博向雨琰李少辉余婧王倩莹李松武汉大学电子信息学院湖北武汉430072 中国空间技术研究院北京100098 武汉量子技术研究院湖北武汉430010

星载光子计数体制激光测距雷达系统具有高重频、高精度等显著优势,但也面临原始数据量大且噪声数据占比过高的问题。为适应星上数据通道的传输能力,需压缩原始数据量并保障信号光子的查全率,因此必须发展以硬件为主体的实时去噪算法。... 详细信息

星载光子计数体制激光测距雷达系统具有高重频、高精度等显著优势,但也面临原始数据量大且噪声数据占比过高的问题。为适应星上数据通道的传输能力,需压缩原始数据量并保障信号光子的查全率,因此必须发展以硬件为主体的实时去噪算法。本文提出一种粗精结合的快速去噪算法,首先基于激光器发射脉宽、系统噪声率、目标特性以及接收光子事件的局部密度信息进行粗去噪,剔除部分噪声光子;再利用直方图统计,对保留的光子事件进行精去噪,确定信号光子区间及最终的信号光子及其时间信息。通过蒙特卡洛仿真和ICESat-2实测数据对算法进行验证,测试结果表明,本算法查全率大于94%、查准率大于93%、调和平均值大于94%,运行效率提高了10%。算法可以实现光子事件的快速实时去噪,为星上硬件实时去噪处理提供了理论基础。

关键词：光子计数激光测距粗精去噪数据密度直方图统计

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可调汽蚀管式调节阀的仿真与试验研究

阀门 2024年第8期 969-976页

作者：何海涛朱崇涛胡锐陈苗赵承卓罗庶胡兆华航天科工火箭技术有限公司

可调汽蚀管式调节阀采用汽蚀文氏管原理，能有效实现推进剂流量的大范围调节，是液体火箭发动机推力调节的关键部件。本文针对不同锥度的两种阀杆，通过仿真和试验对其调节性能进行了分析研究，获得了阀杆不同行程下的有效流通面积和相... 详细信息

可调汽蚀管式调节阀采用汽蚀文氏管原理，能有效实现推进剂流量的大范围调节，是液体火箭发动机推力调节的关键部件。本文针对不同锥度的两种阀杆，通过仿真和试验对其调节性能进行了分析研究，获得了阀杆不同行程下的有效流通面积和相对压力损失。结果表明：两种阀杆的仿真结果和试验数据吻合较好，均能满足流量线性调节的要求，阀杆B的流量可调范围更大，但在满足流量调节范围的要求下，阀杆A的调节精度会更高。两种阀杆的相对压力损失试验结果相差不大，但阀杆A仿真得到的相对压力损失更大。通过仿真结果和试验数据的对比，验证了仿真模型的正确性，为相关设计提供重要参考。

关键词：调节阀火箭发动机变推力汽蚀仿真与试验研究

Damage characteristics of YAG transparent ceramics under different loading conditions

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Defence Technology（防务技术） 2022年第8期18卷 1394-1404页

作者： Kuo Bao Xian-feng Zhang Gui-ji Wang Jia-jie Deng tao chong Dan Han Bing-qiang Luo Meng-ting Tan School of Mechanical Engineering Nanjing University of Science&TechnologyNanjing210094China Institute of Fluid Physics CAEPMianyang621900China Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai200050China

YAG (Y_(3)Al_(5)O_(12)) transparent ceramics have attractive application prospects for transparent armor protection modules because of their excellent light transmittance and anti-ballistic capability. Understanding the fracture behavior and damage mechanism of YAG is necessary for armor design. To explore the damage characteristics of YAG under compression and tension, shock compression and shockless spalling experiments with soft recovery technique are conducted. The spall strength of YAG is obtained and the recovered samples are observed by CT and SEM. It is shown that the macroscopic damage characteristic of YAG under compression is vertical split cracks with oblique fine cracks distributed in the entire sample, while that under tension is horizontal transgranular cracks concentrated near the main spall surface. The cracks generated by macroscopic compression, tension and shear stress extend in similar tensile form at the microscale. The proportion of transgranular fractures on spall surfaces is higher than that of cracks induced by macroscopic compression. Meanwhile, higher loading rate and longer loading duration increase the transgranular fracture percentage.

关键词： YAG transparent Ceramics Damage characteristics Impact loading Shock compression Spall strength

Facile molybdenum and aluminum recovery from spent hydrogenation catalyst

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Chinese Journal of Chemical Engineering 2024年第5期69卷 72-78页

作者： Zhenhui Lv Jianan Li Dong Xue tao Yang Gang Wang chong Peng State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian 116024China Dalian Research Institute of Petroleum and Petrochemicals SINOPECDalian 116041China

Industrial catalyst waste has emerged as a hazardous pollutant that requires safe and proper disposal after the unloading *** a valuable and sustainable strategy for its treatment is a significant challenge compared to traditional *** this study,we present a facile method for the recovery of molybdenum and aluminum contents from spent Mo-Ni/Al_(2)O_(3) hydrogenation catalysts through crystallization separation and ***,the recovered molybdenum and aluminum are utilized as active metals and carriers for the preparation of new *** properties were thoroughly analyzed and investigated using various characterization *** hydrogenation activity of these newly prepared catalysts was evaluated on a fixed-bed small-scale device and compared with a reference catalyst synthesized from commercial raw ***,the hydrogenation activity of the catalysts was further assessed by using the entire distillate oil of coal liquefaction as the raw oil,specifically focusing on denitrogenation and aromatic *** work not only offers an effective solution for recycling catalysts but also promotes sustainable development.

关键词： Waste treatment Alumina Hydrogenation Catalyst Crystallization Precipitation

High-temperature frictional wear behavior of MCrAlY-based coatings deposited by atmosphere plasma spraying

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International Journal of Minerals,Metallurgy and Materials 2017年第2期24卷 222-228页

作者： chong tao Lei Wang Xiu Song Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) Northeastern UniversityShenyang 110819China Baosteel Group Shanghai Meishan Iron&Steel Co.Ltd. Nanjing 210039China

Al2O3-r2O03/NiCoCrAIYTa coatings were prepared via atmosphere plasma spraying （APS）. The microstructure and phase com- position of the coatings were analyzed by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, laser confocal scanning microsco- py （LSCM）, and transmission electron microscopy （TEM）. The dry frictional wear behavior of the coatings at 500℃ in static air was inves- tigated and compared with that of 0Cr25Ni20 steel. The results show that the coatings comprise the slatted layers of oxide phases, unmelted particles, and pores. The hot abrasive resistance of the coatings is enhanced compared to that of 0Cr25Ni20, and their mass loss is approxi- mately one-fifteenth that of 0Cr25Ni20 steel. The main wear failure mechanisms of the coatings are abrasive wear, fatigue wear, and adhe- sive wear.

关键词： metal matrix composites composite coatings wear behavior high temperature properties plasma spraying

Inhibition of proliferation,migration,and invasiveness of bladder cancer cells through SAPCD2 knockdown

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BIOCELL 2024年第1期48卷 97-109页

作者： chong SHEN JIAJUN YAN YU REN ZHIRONG ZHU XIAOLONG ZHANG SHUIXIANG tao Department of Urology Shaoxing People’s HospitalShaoxing HospitalZhejiang University School of MedicineShaoxingChina

Introduction:Bladder cancer(BC)has a high incidence and mortality rate *** anaphasepromoting complex domain containing 2(SAPCDC2)is over-expressed in a variety of ***:This study investigated the effects of SAPCD2 knockdown on BC ***:T24 and UMUC3 cell models and the xenografted BC tumor model with SAPCD2 knockdown were established to observe the malignant phenotype of BC cells by cell counting kit-8 assay,colony formation test,wound healing,and Transwell assay,mRNA and proteins expressions were measured with quantitative real-time polymerase chain reaction,western blotting,and tissue *** chloride agonist on the Wnt/β-catenin pathway was used to clarify the molecular mechanism of SAPCD2 ***:SAPCD2 expression was significantly higher in BC cell lines than in SVHUC-1 ***2 knockdown inhibited viability and cloning,hindered the G0/G1 phase of the cell cycle in UMUC3 and T24 cells,and decreased the migration and invasiveness of BC ***2 knockdown inhibited expression levels of cyclin D1,cyclin B1,N-cadherin,vimentin,Snail,β-catenin,c-Myc,and cyclin-dependent kinase 4,while the P21 and E-cadherin were raised by SAPCD2 ***,lithium chloride reversed the effects of SAPCD2 knockdown on the expression levels of the above proteins in UMUC3 and T24 *** vivo,SAPCD2 knockdown inhibited the volume,weight,and expression of Ki-67 andβ-catenin in tumors and increased the E-cadherin ***:SAPCD2 knockdown inhibits the malignant phenotype of BC via a pathway involvingβ-catenin.

关键词： Bladder cancer SAPCD2 β-catenin c-Myc CDK4 Lithium chloride

Prognostic relevance of ventricular arrhythmias in surgical patients with gastrointestinal tumors

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 1787-1795页

作者： Jiao-Jie Xue Su-Tian Hu chong-chong Wang Zhi-chong Chen Shi-Yao Cheng Shu-Qi Yu Hua-Jing Peng Yi-tao Zhang Wei-Jie Zeng Department of Cardiovascular Internal Medicine Sun Yat-sen University Sixth Affiliated HospitalGuangzhou 510655Guangdong ProvinceChina Department of Cardiovascular Internal Medicine The Fifth Affiliated Hospital of Guangzhou Medical UniversityGuangzhou 510700Guangdong ProvinceChina Department of Ultrasound Fuwai HospitalChinese Academy of Medical Sciences ShenzhenShenzhen 518052Guangdong ProvinceChina Department of Kidney Internal Medicine Sun Yat-sen University First Affiliated HospitalGuangzhou 510062Guangdong ProvinceChina

BACKGROUND Individuals diagnosed with gastrointestinal tumors are at an increased risk of developing cardiovascular *** which,ventricular arrhythmia is a prevalent clinical *** suggests that ventricular arrhythmias may have predictive value in the prognosis of patients with gastrointestinal *** To explore the prognostic value of ventricular arrhythmias in patients with gastrointestinal tumors receiving *** We retrospectively analyzed data from 130 patients undergoing gastrointestinal tumor *** patients were evaluated by a 24-h ambulatory electrocardiogram(ECG)at the Sixth Affiliated Hospital of Sun Yat-sen University from January 2018 to June ***,41 general healthy age-matched and sexmatched controls were *** were categorized into survival and non-survival *** primary endpoint was all-cause mortality,and secondary endpoints included major adverse cardiovascular events(MACEs).RESULTS Colorectal tumors comprised 90%of *** ambulatory ECG monitoring revealed that among the 130 patients with gastrointestinal tumors,100(76.92%)exhibited varying degrees of premature ventricular contractions(PVCs).Ten patients(7.69%)manifested non-sustained ventricular tachycardia(NSVT).The patients with gastrointestinal tumors exhibited higher PVCs compared to the healthy controls on both conventional ECG[27(21.3)vs 1(2.5),P=0.012]and 24-h ambulatory ECG[14(1.0,405)vs 1(0,6.5),P35/24 h to all-cause mortality,and NSVT was associated with ***,neither PVC burden nor NSVT independently predicted outcomes according to multivariate *** Patients with gastrointestinal tumors exhibited elevated ***>35/24 h and NSVT detected by 24-h ambulatory ECG were prognos

关键词： Ventricular arrhythmia Gastrointestinal tumor Major adverse cardiovascular events Prognostic Surgery

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拉萨市医学生疏离感的影响因素研究

西藏医药 2024年第1期45卷 100-102页

作者：邹青松徐梦伟杨丽君沙马古布旦增卓嘎陶冲西藏大学医学院西藏拉萨850011 江南大学无锡医学院江苏无锡214122 四川大学华西护理学院/四川大学华西医院四川成都610041

目的了解拉萨市高校医学生疏离感现况并分析医学生疏离感的影响因素,为采取针对性的措施降低医学生疏离感提供依据。方法采用随机整群抽样的方法,通过自编人口社会学问卷和青少年疏离感量表进行调查。结果医学生总体疏离感得分为(3.33... 详细信息

目的了解拉萨市高校医学生疏离感现况并分析医学生疏离感的影响因素,为采取针对性的措施降低医学生疏离感提供依据。方法采用随机整群抽样的方法,通过自编人口社会学问卷和青少年疏离感量表进行调查。结果医学生总体疏离感得分为(3.33±0.84)。单因素分析表明,疏离感得分在人口社会学变量中的性别、是否有留守经历、户口类型、父母是否离异、与父母沟通频率分组(P<0.05)。多元线性回归分析:与父母沟通频率、父母离异、性别、是否有留守经历是医学生疏离感的影响因素,并能解释医学生疏离感6.3%的方差变异(F=12.464,R2=0.063,P<0.001)。结论高校医学生疏离感处于中等偏下水平,男生、有留守经历、父母离异和与父母沟通频率低的医学生疏离感水平相对较高。学校应该重视医学生心理健康问题,可以举办有针对的心理健康宣教活动,以降低医学生较高水平的疏离感。

关键词：医学生疏离感横断面调查影响因素

Automated machine learning for rainfall-induced landslide hazard mapping in Luhe County of Guangdong Province,China

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China Geology 2024年第2期7卷 315-329页

作者： tao Li Chen-chen Xie chong Xu Wen-wen Qi Yuan-dong Huang Lei Li National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Key Laboratory of Compound and Chained Natural Hazards Dynamics Ministry of Emergency Management of ChinaBeijing 100085China Institute of Disaster Prevention Sanhe 065201China School of Emergency Management Science and Engineering University of Chinese Academy of SciencesBeijing 100049China

Landslide hazard mapping is essential for regional landslide hazard *** main objective of this study is to construct a rainfall-induced landslide hazard map of Luhe County,China based on an automated machine learning framework(AutoGluon).A total of 2241 landslides were identified from satellite images before and after the rainfall event,and 10 impact factors including elevation,slope,aspect,normalized difference vegetation index(NDVI),topographic wetness index(TWI),lithology,land cover,distance to roads,distance to rivers,and rainfall were selected as *** WeightedEnsemble model,which is an ensemble of 13 basic machine learning models weighted together,was used to output the landslide hazard assessment *** results indicate that landslides mainly occurred in the central part of the study area,especially in Hetian and *** 102.44 s were spent to train all the models,and the ensemble model WeightedEnsemble has an Area Under the Curve(AUC)value of92.36%in the test *** addition,14.95%of the study area was determined to be at very high hazard,with a landslide density of 12.02 per square *** study serves as a significant reference for the prevention and mitigation of geological hazards and land use planning in Luhe County.

关键词： Landslide hazard Heavy rainfall Harzard mapping Hazard assessment Automated machine learning Shallow landslide Visual interpretation Luhe County Geological hazards survey engineering