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Used car price prediction based on XGBoost and retention rate

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The Journal of China Universities of Posts and Telecommunications 2024年第3期31卷 72-79页

作者： Shen Yutian Chen jian Dai min Zhang Sirui Xu Jing Wang Qing College of Mechanical Engineering Yangzhou UniversityYangzhou 225127China College of Economics and Management Southeast University Chengxian CollegeNanjing 210088China Shandong Shuncheng Automobile Trade Co. LtdJinan 250000China

In order to improve the accuracy of used car price prediction,a machine learning prediction model based on the retention rate is proposed in this ***,a random forest algorithm is used to filter the variables in the *** main characteristic variables that affect used car prices,such as new car price,service time,mileage and so on,are filtered ***,the linear regression classification method is introduced to classify the test data into high and low retention rate *** that,the extreme gradient boosting(XGBoost)regression model is built for the two datasets *** prediction results show that the comprehensive evaluation index of the proposed model is 0.548,which is significantly improved compared to 0.488 of the original XGBoost ***,compared with other representative machine learning algorithms,this model shows certain advantages in terms of mean absolute percentage error(MAPE),5%accuracy rate and comprehensive evaluation *** a result,the retention rate-based machine learning model established in this paper has significant advantages in terms of the accuracy of used car price prediction.

关键词： random forest data dimensionality reduction extreme gradient boosting(XGBoost) retention rate price prediction

Solidification behaviour and hot cracking susceptibility of a novel Ni-based superalloy

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Journal of Iron and Steel Research International 2024年第4期31卷 956-966页

作者： yue Chen Shao-min Lv Xing-fei Xie Xiao-can Wen Jng-long Qu Jin-hui Du High-Temperature Materials Institute China Iron and Steel Research Institute Group Co.Ltd.Beijing 100081China Beijing GAONA Materials and Technology Co. Ltd.Beijing 100081China Sichuan CISRI-GAONA Forging Co. Ltd.Deyang 610000SichuanChina

A novel Ni-based superalloy GH4151,with a γ′ volume fraction of about 55%and a service temperature capability up to 8oo oC,was *** to the different cooling conditions of various regions during the solidification of ingots,significant cooling rate variations may lead to the occurrence of hot *** scanning laser microscope was utilised to investigate the solidification process and phase precipitation behaviour of the GH4151 under wide range cooling *** characteristics of L→γ transformation were analysed,and the growth rates of at each stage were *** segregation behaviour was predicted using the Scheil equation,and the predicted results match well with the experimental *** sensitivity coefficient for hot cracking was modified,and cracking sensitivity coefficient values for the alloy under different cooling rates were computed,revealing that the alloy is most susceptible to hot cracking at 10℃/min cooling ***,controlling the cooling rate can reduce the possibility of hot cracking in ingot.

关键词： Ni-based superalloy Solidification behaviour In-situ observation Clyne and Davies's criterion:Hot cracking susceptibility

Salmonella Grumpensis Causing Diarrhea in Children—Shanghai Municipality,China,2023

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China CDC weekly 2024年第18期6卷 396-400,I0006,I0007页

作者： yue Liu Xuebin Xu Wenqin Wang Wenjia Xiao Yi Hu Xin Chen min Chen Shanghai Municipal Center for Disease Control and Prevention ShanghaiChina Pudong New Area Center for Disease Control and Prevention ShanghaiChina Department of Epidemiology Key Laboratory of Public Health Safety of Ministry of EducationSchool of Public HealthFudan UniversityShanghaiChina

Summary What is already known about this topic?Foodborne diseases are a growing public health concern with a notable disease burden in *** is added by this report?Two children with diarrhea visited a healthcare facility within 24 hours on August 1 and 2,*** Grumpensis was detected in their stool samples by the public health *** genome sequencing(WGS)analysis revealed characteristics typical of outbreak *** the origin of the outbreak was unknown,the possibility of a hidden shared infection was deemed feasible.

关键词： diarrhea diseases Whole

Copper-Free Click Chemistry-Mediated Assembly of Single Quantum Dot Nanosensor for Accurately Monitoring Locus-Specific m^(6)A in Cancer Cells

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Chinese Journal of Chemistry 2024年第5期42卷 499-504页

作者： yue-Ying Li Ning-Ning Zhao Yi-Xuan Geng Qian Han jian-Ge Qiu Bing-Hua jiang Zi-yue Wang Chun-Yang Zhang Translational Medicine Center The First Affiliated Hospital of Zhengzhou UniversityThe Academy of Medical SciencesHenan Institute of Medical and Pharmaceutical Sciences BGI CollegeZhengzhou UniversityZhengzhouHenan450052 China College of Chemistry Chemical Engineering and Materials ScienceShandong Normal UniversityJinanShandong250014 China School of Chemistry and Chemical Engineering Southeast UniversityNanjingJiangsu211189 China

N6-methyladenosine(m^(6)A)plays an important role in embryogenesis,nuclear export,transcription splicing,and protein translation ***,we demonstrate a copper-free click chemistry-mediated assembly of single quantum dot(QD)nanosensor for accurately monitoring locus-specific m^(6)A in cancer *** m^(6)A-sensitive endoribonuclease MazF can digest the unmethylated A-RNA,and the intact m^(6)A-RNA then hybridizes with DNA probes a and b to produce a sandwich hybrid,initiating the click chemistry to generate probe a–b ligation product via first tandem ligation detection reaction(LDR)***,DNA probes c and d can hybridize with the probe a–b ligation product to generate the probe c–d ligation product via second LDR *** LDR cycles can be repeated through denaturation and annealing reaction to generate abundant biotin-/fluorophore-modified probe c–d ligation products that can easily assemble on the QD surface to induce distinct fluorescence resonance energy transfer(FRET)between QD and *** assay can be homogenously performed without the involvement of copper catalyst,m^(6)A-specific antibody,radioactive labeling,ligase enzyme,enzymatic reverse transcription,and next-generation ***,it can discriminate even 0.01% m^(6)A level in complex samples and accurately measure cellular m^(6)A-RNA expression,providing a promising avenue for clinical diagnostics and biomedical research.

关键词： RNA methylation Click chemistry Förster resonance energy transfer Biosensor Cancer

Influence of transcatheter arterial embolization on symptom distress and fatigue in liver cancer patients

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 810-818页

作者： Xu-min Yang Xu-Yan Yang Xin-Yu Wang yue-Xia Gu Department of Nursing The First Affiliated Hospital of Naval Medical University(Changhai Hospital)Shanghai 200433China Department of Thyroid Breast and Vascular SurgeryShanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China Department of Nursing Shanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China

BACKGROUND Hepatocellular carcinoma(HCC)is a prevalent malignancy,and transcatheter arterial embolization(TAE)has emerged as a pivotal therapeutic ***-ever,TAE may induce symptom distress and fatigue,adversely affecting the quality of life of *** To investigate symptom distress,fatigue,and associated factors in HCC patients undergoing *** We used a cross-sectional design and purposive sampling to enroll HCC patients who underwent TAE at our institution from January to December ***-naires were utilized to collect data on symptom distress and fatigue scores from the first to the third day after *** Our study revealed a significant reduction in fatigue and symptom distress among patients after ***,fatigue,insomnia,fever and abdominal dis-tension were the most common symptoms troubling patients during the first 3 d *** status,presence of family support,physical functional status,age,and symptom distress were identified as predictors of fatigue in *** Healthcare professionals should educate HCC patients on symptom distress and INTRODUCTION Hepatocellular carcinoma(HCC)ranks as the fifth most prevalent cancer and the third leading cause of cancer-related mortality *** intervention remains the cornerstone of HCC treatment;however,due to the challenges associated with early diagnosis and the lack of specific diagnostic markers,a considerable proportion of patients are diagnosed at advanced stages,rendering them ineligible for surgical *** arterial embolization(TAE)is an interventional therapeutic approach involving the insertion of a fine catheter via the femoral artery to reach the vasculature near the tumor *** aims to obstruct the arterial supply to the tumor by deploying embolic agents,thereby inducing necrosis in cancer *** procedure is suitable for patients with good liver function and overall health,particularly those with large HCCs that ha

关键词： Transcatheter arterial embolization Fatigue Symptom distress Hepatocellular carcinoma Influencing factors

Concerted Steric and Electronic Strategy in Thermostable Salicylaldiminato Nickel Catalysts for Ethylene(Co)polymerization

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Chinese Journal of Polymer Science 2024年第8期42卷 1085-1092页

作者： Hong-Yu Ji Hong-Liang Mu Chun-Feng Tang Yu-Xing Zhang yue Chi Zhong-Bao jian Key Laboratory of Advanced Structural Materials Ministry of EducationSchool of Materials Science and EngineeringChangchun University of TechnologyChangchun 130012China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Olefin polymerization is one of the most im portant chemical reactions in *** work presents a strategy that emphasizes the synergistic meta/poro-steric hindrance of N-aryl groups and electronic effects in newly synthesized neutral salicylaldiminato nickel *** nickel(Ⅱ)catalysts exhibit exceptional thermostability,ranging from 30℃to 130℃,demonstrating enhanced catalytic activities and broadly regulated polyethylene molecular weights(3-341 kg·mol^(-1))and controlled polymer branch density(2-102 brs/1000C).The preferred catalyst Ni3 with concerted steric and electronic effects enables the production of solid-state semi-crystalline polyethylene materials at temperatures below 90℃.Notably,Ni3 exhibits an impressive tolerance of 110℃and can withstand even the challenging polymerization temperature of 130℃,leading to the production of polyethylene wax and ***,functionalized polyethylene is produced.

关键词： Polyolefin Salicylaldiminato ligand Nickel catalyst Oil Wax

Synthesis,chemical bonding and reactivity of new medium-sized polyarsenides

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Chinese Chemical Letters 2024年第7期35卷 497-501页

作者： Xu-Hui yue Xiang-Wen Zhang Hui-min He Lei Qiao Zhong-ming Sun State Key Laboratory of Element-Organic Chemistry Tianjin Key Lab for Institution Rare Earth Materials and ApplicationsSchool of Materials Science and EngineeringNankai UniversityTianjin 300350China Department of Physics Institute of Computational and Applied PhysicsTaiyuan Normal UniversityJinzhong 030619China

Gaining an understanding of the growth mechanism from single atoms to clusters and bulk materials continues to present a ***,it is important to explore the evolving trends of clusters in the structure and properties during the size *** this work,we report the synthesis and characterization of two medium-sized chain-like polyarsenic anions.[As_(21)]^(3-)represents a trimeric example of polyarsenic anion assembled through oxidative coupling of As_(7)^(3-)*** anion As_(18)^(4-)included in[As_(18)MO_(2)(CO)_(8)]^(4-)is regarded as formed by two realgar-type As_(8)subunits connected by a dinuclear AsAs *** As_(18)cluster was previously predicted by theory,and this is the first time successfully synthesized using wet chemistry ***,small-sized polyarsenides As_(2)^(2-)and As_(10)^(2-)were found in compound[K(18-crown-6)]_(3)[As_(10)]_(0.5)[As_(4){Mo(CO)_(3)}_(2)]_(0.5)·*** these,the former exhibits coordination with metal ***-crystal X-ray diffraction combined with quantum chemical calculations revealed the formation of double bonded As_(2)^(2-)stabilized by metal carbonyl *** work demonstrates a novel synthetic approach for the preparation of new polyarsenides and highlights their intriguing bonding characteristics,laying the foundation for the synthesis of such compounds and paving the way for their potential applications.

关键词： Polyarsenide Zintl anions Chain-like cluster DFT calculations AdNDP

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Optimizing 2D-metal contact in layered Tin-selenide via native oxide modulation

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Nano Research 2024年第4期17卷 3014-3020页

作者： yue Zheng Qi You Zhentian Yin jian Tang Ke jiang Zihao Xie Henan Li Cheng Han Yumeng Shi International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of ministry of Education Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China College of Electronics and Information Engineering Shenzhen UniversityShenzhen 518060China

The discovery of two-dimensional(2D)semiconductor has opened up new avenues for the development of short-channel field-effect transistors(FETs)with desired electrical *** them,orthorhombic tin-selenide(SnSe)has garnered increasing attention due to its potential applications in a variety of electronic,optoelectronic,and thermoelectric ***,the realization of high-performance SnSe FETs with low contact resistance(Rc)remains a ***,we systematically investigate the contact of few-layer SnSe FETs through the modulation of native oxide on SnSe by using different *** is found that chromium(Cr)-contacted devices possess the best FET performance,such as electron mobility up to 606 cm^(2)/(V·s)at 78 K,current on/off ratio exceeding 1010,and saturation current of~550μA/μm,where a negligible Schottky barrier(SB)of~30 meV and a low contact resistance of~425Ωμm are achieved.X-ray photoelectron spectroscopy(XPS)and cross-sectional electron dispersive X-ray spectroscopy(EDX)results further reveal that the improved contact arises from the Cr-induced reduction of native oxide(SnOx)to Sn,which thins the tunneling barrier for efficient electron *** findings provide a deep insight into the 2D-metal contact of SnSe and pave the way for its applications in future nanoelectronics.

关键词： few-layer SnSe field-effect transistors(FETs) Cr contact native oxide contact resistance(Rc) Schottky barrier(SB)

Understanding Why People Complain: Using Spatial Embeddedness to Explore Residents' Satisfaction in China's Danwei Neighborhood Renovation

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China City Planning Review 2024年第3期 51-61页

作者： Li yue Zhou Peiling Li min School of Architecture Chang'an University Department of Urban and Rural Planning Harbin Institute of Technology Shenzhen

Against the backdrop of China's socio-economic transition, there is a growing imperative to examine neighborhood renovation initiatives in addressing the emerging needs of residents. Developing Granovetter's classic work on embeddedness, this paper proposes a conceptual framework of spatial embeddedness to understand changes in the physical space brought about by neighborhood renovation, in order to explore how it affects residents' satisfaction in a dynamic temporal and spatial process. It presents whether and why residents' real feelings produced from their interaction with neighborhood renovation are(un)different, and how their feelings are shaped based on six months of fieldwork in a danwei neighborhood in Xi'an, China. The paper conceptualizes the relationship between the neighborhood space and embeddedness by adopting spatial embeddedness to capture the interplay of temporal, spatial, and social factors in the process of danwei neighborhood renovation. This framework not only integrates multiple perspectives and scales, but also reflects different levels of residents' satisfaction, trying to establish a connection between the abstract space and the renovation space. It suggests that spatial embeddedness should be considered as a response to the negative social impacts resulting from changes in the physical space in neighborhood renovation.

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