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Elevated-temperature tribological behavior of Ti–B–C–N coatings deposited by reactive magnetron sputtering

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Rare Metals 2015年第12期34卷 838-843页

作者： xiang-yang chen Shao-Fu Huang Sheng-Li Ma Run Huang Jin Zhang Hai-Xia Hu School of Mechanical Engineering Anhui University of Science and Technology State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University School of Materials Science and Engineering Anhui University of Science and Technology

Quaternary Ti–B–C–N coatings with various carbon contents were deposited on high-speed steel (HSS) substrates by reactive magnetron sputtering (RMS) system. The elevated-temperature tribological behavior of Ti–B–C–N coatings was explored using pin-on-disk tribometer, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The present results show that the steady-state friction coefficient value and the instantaneous friction coefficient fluctuation range of Ti–B–C–N coatings decrease as carbon content increases at 100 and 300°C, while the steady-state friction coefficient value of all Ti–B–C–N coatings becomes higher than 0.4 at 500°C. As ambient temperature increases, the running-in periods of all Ti–B–C–N coatings become shorter. Wear damage to Ti–B–C–N coatings during sliding at elevated temperature is mainly caused by adhesive wear, and adhesive-wear damage to Ti–B–C–N coatings increases as ambient temperature increases; however, higher carbon content is beneficial for decreasing the adhesive-wear damage to Ti–B–C–N coatings during sliding at elevated temperature.

关键词： Tribological behavior Ti–B–C–N coatings Reactive magnetron sputtering Elevated temperature

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Effect of nursing on postoperative respiratory function and mental health of lung cancer patients

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World Journal of Clinical Cases 2024年第5期12卷 922-930页

作者： xiang yang Dan Yin Shi-Qing chen Department of Rehabilitation The First People's Hospital of Jiangxia DistrictWuhan(Union Jiangnan Hospital Huazhong University of Science and Technology)Wuhan 430200Hubei ProvinceChina Department of Intensive Care The First People's Hospital of Jiangxia DistrictWuhan(Union Jiangnan Hospital Huazhong University of Science and Technology)Wuhan 430200Hubei ProvinceChina Department of Neurology The First People's Hospital of Jiangxia DistrictWuhan(Union Jiangnan Hospital Huazhong University of Science and Technology)Wuhan 430200Hubei ProvinceChina

BACKGROUND Both pulmonary rehabilitation training and psychological care have been shown to have a positive effect on the postoperative recovery of patients with lung cancer.However,few studies have combined the two to explore their combined effect.Therefore,this study aimed to investigate the effects of pulmonary rehabil-itation training combined with psychological care on postoperative respiratory function and mental health in lung cancer patients.AIM To investigate effect of nursing on postoperative respiratory function and mental health of lung cancer patients.METHODS 122 cases of lung cancer patients who underwent surgical treatment in our hospital and were treated in our department from January 2022 to April 2023 were selected and randomly divided into the control group and observation group.The control group performed the routine care intervention.The obser-vation group was given pulmonary rehabilitation training and psychological care based on conventional nursing interventions.Forced expiratory volume,forced vital capacity.Maximum ventilatory volume(MVV)in one second was measured,and the patient's 6-min walking distance and dyspnoea index scale were used to assess the patient's respiratory condition.The Connor-Davidson resilience scale(CD-RISC),self-rating anxiety scale(SAS),and self-rating depression scale(SDS)were used to evaluate the mental health of the patients.RESULTS There was no difference between the two groups regarding age,gender,education level,surgical procedure,type of pathology,and treatment(P>0.05).After treatment,MVV,6-min walking distance,toughness,strength,optimism,and total CD-RISC scores were significantly higher in the observation group(P<0.05),dyspnoea scores,SAS,and SDS scores were substantially lower in the control group compared to the observation group(P<0.05).CONCLUSION Pulmonary rehabilitation training combined with psychological care for patients after lung cancer resection could improve lung function,enhance daily activities,effectively relieve negative emotions such as anx

关键词： Pulmonary rehabilitation training Psychological care Lung cancer Postoperative care Respiratory function

Interregional Value-Added Tax in the Era of E-Commerce: Tax Policy Design Based on Big Data from Online Retailing

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Journal of Social Computing 2024年第1期5卷 46-57页

作者： Yu chen Luwei xiang Hu yang School of Public Finance and Taxation Central University of Finance and EconomicsBeijing 100008China School of Management and Economics The Chinese University of Hong KongShenzhen 518172China School of Information Central University of Finance and EconomicsBeijing 100008China

The value-added tax(VAT)in China is levied and allocated based on the origin principle.Under the background of the increasing substitution of online retail for traditional offline retail,this mechanism will exacerbate the disparity of regional tax revenue,and intensify tax competition among local governments.Therefore,reconsidering the allocation mechanism of value-added tax in China can be an important policy decision,and it is influenced by various economic and social factors.Firstly,we utilize large-scale retail transaction data from an e-commerce platform to measure regional disparities in retail and consumption among different regions and then reveals present tax policy results in revenue imbalance in different regions.Secondly,we establish a model based on game theory to illustrate how the origin principle leads to fierce tax competition among regions.Furthermore,by establishing and solving tax allocation models between local governments and the central government,this study simulates and calculates the degree of revenue imbalance under different scenarios and attempts to propose policy measures.The results indicate that implementing the destination principle will reduce regional tax imbalances.Moreover,adjusting the allocation ratio between the central government and local governments based on city levels is advantageous for further reducing regional tax revenue disparities.

关键词： value-added tax e-commerce destination principle origin principle

Precipitating thermally reinforcement phase in aluminum alloys for enhanced strength at 400℃

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Journal of Materials Science & Technology 2024年第5期172卷 71-82页

作者： xiang Su Yuan Lei yang chen Hongjie Qu Zhixiang Qi Gong Zheng Xu Liu Henggao xiang Guang chen National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China School of Aviation and Mechanical Engineering Changzhou Institute of TechnologyChangzhou 213032China

Heat-resistant aluminum alloys are widely used in aerospace and automotive fields for manufacturing hot components due to their advantages in lightweight design and energy conservation.However,the high-temperature strength of existing cast aluminum alloys is always limited to about 100 MPa at 350℃due to coarsening and transformation of strengthening phases.Here,we reveal that the yield strength and ultimate tensile strength of the T6 state Al-8.4Cu-2.3Ce-1.0Mn-0.5Ni-0.2Zr alloy at 400◦C increase by 34%and 44%after re-aging at 300℃for 100 h,and its thermal strength exhibits distinguished ad-vantage over traditional heat-resistant aluminum alloys.The enhanced elevated-temperature strength is attributed to the reprecipitation of the Ni-bearing T-Al_(20)Cu_(2)Mn_(3)phase,whose number density increases over one time.The significant segregation of Ni,Ce,and Zr elements at the interfaces helps improve the thermal stability of the T phase.The thermostable T phase effectively strengthens the matrix by in-hibiting dislocation motion.Meanwhile,a highly interconnected 3D intermetallic network along the grain boundaries can still remain after long-term re-aging at 300℃,which is conducive to imposing a drag on the grain boundaries at high temperatures.This finding offers a viable route for enhancing the elevated-temperature strength of heat-resistant aluminum alloys,which could provide expanded opportunities for higher-temperature applications.

关键词： Aluminum alloys Precipitation Thermally reinforcement phase Re-aging treatment High-temperature strength

Effect of short neuropeptide F signaling on larval feeding in Mythimna separata

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Insect Science 2024年第2期31卷 417-434页

作者： Mei-Mei Li Qi yang Li-Hui chen Yan-Ying Li Jun-xiang Wu xiang-Li Xu State Key Laboratory of Crop Stress Biology in Arid Areas College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi ProvinceChinaand School of Agricultural Sciences Jiangxi Agricultural UniversityNanchangChina

Mythimna separata is a notorious phytophagous pest which poses serious threats to cereal crops owing to the gluttony of the larvae.Because short neuropeptide F(sNPF)and its receptor sNPFR are involved in a diversity of physiological functions,especially in functions related to feeding in insects,it is a molecular target for pest control.Herein,an sNPF and 2 sNPFRs were identified and cloned from M.separata.Bioinformatics analysis revealed that the sNPF and its receptors had a highly conserved RLRFamide C-terminus and 7 transmembrane domains,respectively.The sNPF and its receptor genes were distributed across larval periods and tissues,but 2 receptors had distinct expression patterns.The starvation-induced assay elucidated that sNPF and sNPFR expression levels were downregulated under food deprivation and recovered with subsequent re-feeding.RNA interference knockdown of sNPF,sNPFR1,and sNPFR2 by injection of double-stranded RNA into larvae not only suppressed food consumption and increased body size and weight,but also led to decrease of glycogen and total lipid contents,and increase of trehalose compared with double-stranded green fluorescent protein injection.Furthermore,molecular docking was performed on the interaction mode between sNPFR protein and its ligand sNPF based on the 3-dimensional models constructed by AlphaFold;the results indicated that both receptors were presumably activated by the mature peptide sNPF-2.These results revealed that sNPF signaling played a considerably vital role in the feeding regulation of M.separata and represents a potential control target for this pest.

关键词： feeding regulation Mythimna separata pest control target RNA interference short neuropeptide F sNPF receptors

A process-oriented approach for identifying potential landslides considering time-dependent behaviors beyond geomorphological features

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 961-978页

作者： xiang Sun Guoqing chen Xing yang Zhengxuan Xu Jingxi yang Zhiheng Lin Yunpeng Liu State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu610059China China Railway Eryuan Engineering Group Co.Ltd. Chengdu610031China Power China chengdu Engineering Co.Ltd. Chengdu610072China

Geomorphological features are commonly used to identify potential landslides.Nevertheless,overemphasis on these features could lead to misjudgment.This research proposes a process-oriented approach for potential landslide identification that considers time-dependent behaviors.The method integrates comprehensive remote sensing and geological analysis to qualitatively assess slope stability,and employs numerical analysis to quantitatively calculate aging stability.Specifically,a time-dependent stability calculation method for anticlinal slopes is developed and implemented in discrete element software,incorporating time-dependent mechanical and strength reduction calculations.By considering the time-dependent evolution of slopes,this method highlights the importance of both geomorphological features and time-dependent behaviors in landslide identification.This method has been applied to the Jiarishan slope(JRS)on the Qinghai-Tibet Plateau as a case study.The results show that the JRS,despite having landslide geomorphology,is a stable slope,highlighting the risk of misjudgment when relying solely on geomorphological features.This work provides insights into the geomorphological characterization and evolution history of the JRS and offers valuable guidance for studying slopes with similar landslide geomorphology.Furthermore,the process-oriented method incorporating timedependent evolution provides a means to evaluate potential landslides,reducing misjudgment due to excessive reliance on geomorphological features.

关键词： Geomorphological features Evolution history Time-dependent stability calculation Landslides identification Qinghai-Tibet Plateau

Reduced macular thickness and vascular density in abnormal glucose metabolism patients: A meta-analysis of optical coherence tomography (OCT) and OCT angiography studies

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中华医学杂志(英文版) 2024年第9期137卷 1054-1068页

作者： Fu xiangyu Ren xiang chen Wenyue chen Danian Department of Ophthalmology West China Hospital Sichuan University Chengdu Sichuan China Research Laboratory of Ophthalmology and Vision Sciences State Key Laboratory of Biotherapy West China Hospital Sichuan University Chengdu Sichuan China Department of Ophthalmology The People’s Hospital of Guizhou Province Guiyang Guizhou China

Background: Alterations in macular thickness and vascular density before clinically visible diabetic retinopathy (DR) remain inconclusive. This study aimed to determine whether retinal manifestations in abnormal glucose metabolism (AGM) patients differ from those in the healthy individuals.Methods: PubMed, Embase, and Web of Science were searched between 2000 and 2021. The eligibility criteria were AGM patients without DR. Primary and secondary outcomes measured by optical coherence tomography (OCT) and OCT angiography (OCTA) were analyzed and expressed as standardized mean differences (SMDs) with 95% confidence intervals (CIs). A random-effects model was used in the data synthesis. The potential publication bias for the variables was evaluated using Egger’s test.Results: A total of 86 observational studies involving 13,773 participants and 15,416 eyes were included. OCT revealed that compared to healthy controls, the total macular thickness of AGM patients was thinner, including the thickness of fovea (–0.24, 95% CI [–0.39, –0.08];P = 0.002,I2 = 87.7%), all regions of parafovea (–0.32, 95% CI [–0.54, –0.11];P = 0.003;I2 = 71.7%) and the four quadrants of perifovea; the thickness of peripapillary retinal nerve fiber layer (pRNFL), macular retinal nerve fiber layer (mRNFL), and ganglion cell layer (GCL) also decreased. OCTA indicated that the superficial and deep vascular density decreased, the foveal avascular zone (FAZ) area enlarged, and the acircularity index (AI) reduced in AGM individuals.Conclusions: Retinal thinning and microvascular lesions have occurred before the advent of clinically detectable DR; OCT and OCTA may have the potential to detect these preclinical changes.Registration: PROSPERO; http://www.***.york.***.uk/prospero/; No. CRD42021269885.

关键词： Abnormal glucose metabolism Optical coherence tomography Optical coherence tomography angiography Diabetic retinopathy Prediabetes Meta-analysis

Progress on early diagnosing Alzheimer’s disease

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Frontiers of Medicine 2024年第3期18卷 446-464页

作者： Yixin chen Murad Al-Nusaif Song Li xiang Tan Huijia yang Huaibin Cai Weidong Le Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases The First Affiliated Hospital of Dalian Medical UniversityDalian116021China Transgenic Section Laboratory of NeurogeneticsNational Institute on AgingNational Institutes of HealthBethesdaMD20892USA Institute of Neurology Sichuan Provincial People’s HospitalUniversity of Electronic Science and Technology of ChinaChinese Academy of Sciences Sichuan Translational Medicine Research HospitalChengdu610072China

Alzheimer’s disease(AD)is a progressive neurodegenerative disorder that affects both cognition and non-cognition functions.The disease follows a continuum,starting with preclinical stages,progressing to mild cognitive and behavioral impairment,ultimately leading to dementia.Early detection of AD is crucial for better diagnosis and more effective treatment.However,the current AD diagnostic tests of biomarkers using cerebrospinal fluid and/or brain imaging are invasive or expensive,and mostly are still not able to detect early disease state.Consequently,there is an urgent need to develop new diagnostic techniques with higher sensitivity and specificity during the preclinical stages of AD.Various non-cognitive manifestations,including behavioral abnormalities,sleep disturbances,sensory dysfunctions,and physical changes,have been observed in the preclinical AD stage before occurrence of notable cognitive decline.Recent research advances have identified several biofluid biomarkers as early indicators of AD.This review focuses on these non-cognitive changes and newly discovered biomarkers in AD,specifically addressing the preclinical stages of the disease.Furthermore,it is of importance to explore the potential for developing a predictive system or network to forecast disease onset and progression at the early stage of AD.

关键词： Alzheimer’s disease early diagnosis non-cognitive symptoms biomarkers

Cerium oxide inclusion nucleation mechanism based on classical nucleation theory and two-step nucleation

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Journal of Rare Earths 2024年第4期42卷 793-802页

作者： Yutang Li Jun Wang Linzhu Wang Chaoyi chen Shufeng yang Junqi Li xiang Li School of Materials and Metallurgy Guizhou UniversityGuiyang550025China State Key Laboratory of Public Big Data Guizhou UniversityGuiyang550025China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Department of Materials&Metallurgy Engineering Guizhou Institute of TechnologyGuiyang550003China

It is challenging to assess the mechanism responsible for the nucleation of inclusions in metals at high temperatures.The present work therefore systematically investigates the nucleation of cerium oxide inclusions according to classical nucleation theory and a two-step nucleation mechanism.The nucleation rates and nucleation radii of these inclusions are obtained,and the results demonstrate a considerable difference between theoretical and experimental values.On the basis of a two-step nucleation mechanism,(CeO_(2))_(n) and(Ce_(2)O_(3))_(n)(n=1-6)clusters were constructed and the thermodynamic properties of both these clusters and of cerium oxide nanoparticles were analyzed.In addition,the entropies and heat capacity changes of cerium oxides were determined using first principles calculations and are found to be consistent with literature data.The present data indicate that the cerium oxide inclusion nucleation pathway can be summarized as[Ce]+[O]→(CeO_(2))n/(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(2)→core(Ce_(2)O_(3)crystal)-shell((Ce_(2)O_(3))_(2) cluster)nanoparticles→(Ce_(2)O_(3))bulk.

关键词： Cerium oxide inclusion Classical nucleation theory Two-step nucleation mechanism First principles Rare earths

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