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China Foundry 2023年第5期20卷 365-375页

作者： jia-yan sun Rong Yin Ye-yuan Hu Yun-xiang Tan Qing-yan Xu Key Laboratory for Advanced Materials Processing Technology(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Xiaomi AI Lab Beijing100102China

To enhance the accuracy of mechanical simulation in the directional solidification process of turbine blades for heavy-duty gas turbines,a new constitutive model that employs machine learning methods was *** model incorporates incremental learning and transfer learning,thus improves the predictive accuracy and generalization *** account for the anisotropy of the directionally solidified alloy,a deformation direction parameter is added to the model,enabling prediction of the stress-strain relationship of the alloy under different deformation *** predictive capabilities of both models are evaluated using correlation coefficient(R),average relative error(δ),and value of relative error(RE).Compared to the traditional model,the machine learning constitutive model achieves higher prediction accuracy and better generalization *** offers a new approach for the establishment of flow constitutive models for other directionally solidified and single-crystal superalloys.

关键词： Ni-based superalloy constitutive model machine learning directional solidification anisotropy

A novel method for simultaneous measurement of^(222)Rn and^(220)Rn progeny concentrations measured by an alpha spectrometer

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Nuclear Science and Techniques 2025年第1期36卷 127-139页

作者： Zhong-Kai Fan jia-Le sun Hao-Xuan Li Xiang-Ming Cai Hui yang Shou-Kang Qiu yan-Liang Tan jian Shan School of Nuclear Science and Technology University of South ChinaHengyang 421001China College of Physics and Electronic Engineering Hengyang Normal UniversityHengyang 421008China

The accumulation of^(222)Rn and^(220)Rn progeny in poorly ventilated environments poses the risk of natural radiation exposure to the public.A previous study indicated that satisfactory results in determining the^(222)Rn and^(220)Rn progeny concentrations by measuring the total alpha counts at five time intervals within 560 min should be expected only in the case of high progeny concentrations in *** complete the measurement within a relatively short period and adapt it for simultaneous measurements at comparatively lower^(222)Rn and^(220)Rn progeny concentrations,a novel mathematical model was proposed based on the radioactive decay *** model employs a nonlinear fitting method to distinguish nuclides with overlapping spectra by utilizing the alpha particle counts of non-overlapping spectra within consecutive measurement cycles to obtain the concentrations of^(222)Rn and^(220)Rn progeny in *** verification experiments were conducted using an alpha *** experimental results demonstrate that the concentrations of^(222)Rn and^(220)Rn progeny calculated by the new method align more closely with the actual circumstances than those calculated by the total count method,and their relative uncertainties are all within±16%.Furthermore,the measurement time was reduced to 90 min,representing an acceleration of 84%.The improved capability of the new method in distinguishing alpha particles with similar energies emitted from ^(218)Po and^(212)Bi,both approximately 6 MeV,contributed to realizing more accurate *** proposed method has the potential advantage of measuring relatively low concentrations of^(222)Rn and^(220)Rn progeny in air more quickly via air filtration.

关键词： ^(222)Rn ^(220)Rn Progeny concentration Nonlinear fitting method Alpha spectrometer

Gradient age-precipitation behavior induced by gradient nano-grain in Mg-Gd-Ag-Zr alloy

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Journal of Iron and Steel Research International 2025年第1期32卷 19-24页

作者： Bang-jun Li jia-peng sun Jing Han Guo-song Wu College of Materials Science and Engineering Hohai UniversityNanjing 210024JiangsuChina School of Mechanical and Electrical Engineering China University of Mining and TechnologyXuzhou 221116JiangsuChina

Gradient nano-grained structure is frequently engineered into metallic materials,including Mg alloys,to achieve superior combination of strength and ***,the influence of this microstructural feature on aging precipitation behavior remains inadequately *** this study,the age-precipitation behavior of a gradient nano-grained Mg-Gd-Ag-Zr alloy prepared via ultrasonic severe surface rolling was *** result indicates that the aging precipitation behavior exhibits a depth-dependent variation within this *** the nano-grained surface layer,hierarchicalβnano-precipitates are predominant,while at greater depths,the precipitates consist ofβnanoparticles located at grain boundaries,along with intragranularβ′andγ″*** formation ofβnano-precipitates deviates from the conventional precipitation behavior observed in Mg-Gd-Ag alloys,and is attributed to the high density of defects induced by the surface nano-grained *** finding advances our understanding of the precipitation behavior in the alloys with heterogeneous microstructure.

关键词： Mg alloy Gradient Precipitation Aging behavior Microstructure

Ti_(3)C_(2)T_(x) Composite Aerogels Enable Pressure Sensors for Dialect Speech Recognition Assisted by Deep Learning

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Nano-Micro Letters 2025年第5期17卷 1-15页

作者： yanan Xiao He Li Tianyi Gu Xiaoteng jia Shixiang sun Yong Liu Bin Wang He Tian Peng sun Fangmeng Liu Geyu Lu State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012People’s Republic of China School of Integrated Circuits Tsinghua UniversityBeijing 100084People’s Republic of China International Center of Future Science Jilin UniversityChangchun 130012People’s Republic of China

Wearable pressure sensors capable of adhering comfortably to the skin hold great promise in sound ***,current intelligent speech assistants based on pressure sensors can only recognize standard languages,which hampers effective communication for non-standard language ***,we prepare an ultralight Ti_(3)C_(2)T_(x)MXene/chitosan/polyvinylidene difluoride composite aerogel with a detection range of 6.25 Pa-1200 k Pa,rapid response/recovery time,and low hysteresis(13.69%).The wearable aerogel pressure sensor can detect speech information through the throat muscle vibrations without any interference,allowing for accurate recognition of six dialects(96.2%accuracy)and seven different words(96.6%accuracy)with the assistance of convolutional neural *** work represents a significant step forward in silent speech recognition for human–machine interaction and physiological signal monitoring.

关键词： Pressure sensor Wearable sensor Ti_(3)C_(2)T_(x) composite aerogel Dialect speech recognition

miRNA-21-5p is an important contributor to the promotion of injured peripheral nerve regeneration using hypoxia-pretreated bone marrow-derived neural crest cells

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Neural Regeneration Research 2025年第1期20卷 277-290页

作者： Meng Cong Jing-Jing Hu yan Yu Xiao-Li Li Xiao-Ting sun Li-Ting Wang Xia Wu Ling-Jie Zhu Xiao-jia yang Qian-Ru He Fei Ding Hai-yan Shi School of Medicine Nantong UniversityNantongJiangsu ProvinceChina Key Laboratory of Neuroregeneration of jiangsu and Ministry of Education and Coinnovation Center of Neuroregeneration Nantong UniversityNantongJiangsu ProvinceChina Department of Physiology Jiangsu Health Vocational CollegeNanjingJiangsu ProvinceChina Department of Pathology Affiliated Hospital of Nantong UniversityNantongJiangsu ProvinceChina jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair Affiliated Hospital of Nantong UniversityNantongJiangsu ProvinceChina

Our previous study found that rat bone marrow–derived neural crest cells(acting as Schwann cell progenitors)have the potential to promote long-distance nerve ***-based therapy can enhance peripheral nerve repair and regeneration through paracrine bioactive factors and intercellular ***,the complex contributions of various types of soluble cytokines and extracellular vesicle cargos to the secretome remain *** investigate the role of the secretome and extracellular vesicles in repairing damaged peripheral nerves,we collected conditioned culture medium from hypoxia-pretreated neural crest cells,and found that it significantly promoted the repair of sensory neurons damaged by oxygen-glucose *** mRNA expression of trophic factors was highly expressed in hypoxia-pretreated neural crest *** performed RNA sequencing and bioinformatics analysis and found that miR-21-5p was enriched in hypoxia-pretreated extracellular vesicles of neural crest ***,to further clarify the role of hypoxia-pretreated neural crest cell extracellular vesicles rich in miR-21-5p in axonal growth and regeneration of sensory neurons,we used a microfluidic axonal dissociation model of sensory neurons in vitro,and found that hypoxia-pretreated neural crest cell extracellular vesicles promoted axonal growth and regeneration of sensory neurons,which was greatly dependent on loaded ***,we constructed a miR-21-5p-loaded neural conduit to repair the sciatic nerve defect in rats and found that the motor and sensory functions of injured rat hind limb,as well as muscle tissue morphology of the hind limbs,were obviously *** findings suggest that hypoxia-pretreated neural crest extracellular vesicles are natural nanoparticles rich in ***-21-5p is one of the main contributors to promoting nerve regeneration by the neural crest cell *** helps to explain the mechanism of action of the secretome and e

关键词： axotomy cell-free therapy conditioned medium extracellular vesicles hypoxic preconditioning microRNA oxygen-glucose deprivation peripheral nerve injury Schwann cell precursors

Potential preservative mechanisms of cardiac rehabilitation pathways on endothelial function in coronary heart disease

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Science China(Life Sciences) 2025年第1期68卷 158-175页

作者： Wen-Tao sun jian-Yong Du jia Wang Yi-Long Wang Er-Dan Dong Research Center for Cardiopulmonary Rehabilitation University of Health and Rehabilitation Sciences Qingdao Hospital(Qingdao Municipal Hospital)Schoolof Health and Life SciencesUniversityof Health and Rehabilitation SciencesQingdao 266071China Department of Cardiology and Instituteof Vascular Medicine Peking University Third HospitalTheInstituteofCardiovascular SciencesPeking UniversityState Key Laboratoryof Vascular Homeostasisand RemodelingPeking UniversityBeijing 100191China

Cardiac rehabilitation,a comprehensive exercise-based lifestyle and medical management,is effective in decreasing morbidity and improving life quality in patients with coronary heart *** function,an irreplaceable indicator in coronary heart disease progression,is measured by various methods in traditional cardiac rehabilitation pathways,including medicinal treatment,aerobic training,and smoking ***,studies on the effect of some emerging cardiac rehabilitation programs on endothelial function are *** article briefly reviewed the endothelium-beneficial effects of different cardiac rehabilitation pathways,including exercise training,lifestyle modification and psychological intervention in patients with coronary heart disease,and related experimental models,and summarized both uncovered and potential cellular and molecular mechanisms of the beneficial roles of various cardiac rehabilitation pathways on endothelial *** exercise training and some lifestyle interventions,the enhanced bioavailability of nitric oxide,increased circulating endothelial progenitor cells(EPCs),and decreased oxidative stress are major contributors to preventing endothelial dysfunction in coronary heart ***,the preservation of endothelial-dependent hyperpolarizing factors and inflammatory suppression play *** the one hand,to develop more endothelium-protective rehabilitation methods in coronary heart disease,adequately designed and sized randomized multicenter clinical trials should be advanced using standardized cardiac rehabilitation programs and existing assessment *** the other hand,additional studies using suitable experimental models are warranted to elucidate the relationship between some new interventions and endothelial protection in both macro-and microvasculature.

关键词： cardiac rehabilitation coronary heart disease endothelial function

A Novel Model for Describing Rail Weld Irregularities and Predicting Wheel-Rail Forces Using a Machine Learning Approach

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 555-577页

作者： Linlin sun Zihui Wang Shukun Cui Ziquan yan Weiping Hu Qingchun Meng State Key Laboratory of High-Speed Railway Track System China Academy of Railway Sciences Corporation LimitedBeijing100081China Railway Engineering Research Institute China Academy of Railway Sciences Corporation LimitedBeijing100081China School of Aeronautic Science and Engineering Beihang UniversityBeijing100191China

Rail weld irregularities are one of the primary excitation sources for vehicle-track interaction dynamics in modern high-speed *** can cause significant wheel-rail dynamic interactions,leading to wheel-rail noise,component damage,and *** researchers have employed the vehicle-track interaction dynamic model to study the dynamic interactions between wheel and rail induced by rail weld geometry ***,the cosine wave model used to simulate rail weld irregularities mainly focuses on the maximum value and neglects the geometric *** this study,novel theoretical models were developed for three categories of rail weld irregularities,based on measurements of the high-speed railway from Beijing to *** vertical dynamic forces in the time and frequency domains were compared under different running *** forces generated by the rail weld irregularities that were measured and modeled,respectively,were compared to validate the accuracy of the proposed ***,based on the numerical study,the impact force due to rail weld irrregularity is modeled using an Artificial Neural Network(ANN),and the optimum combination of parameters for this model is *** results showed that the proposed model provided a more accurate wheel/rail dynamic evaluation caused by rail weld irregularities than that established in the *** ANN model used in this paper can effectively predict the impact force due to rail weld irrregularity while reducing the computation time.

关键词： Rail weld irregularity high-speed railway vehicle-track coupled dynamics wheel/rail dynamic vertical force artificial neural networks

Study of spatiotemporal variation and annual emission of CH_(4)in Shaoxing yangtze River Delta,China,Using a portable CH4 detector on the UAV

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Journal of Environmental Sciences 2025年第5期151卷 140-149页

作者： Xiaobing Pang Qianqian Shang Lang Chen Songhua sun Gaosheng Zhao Zhentao Wu Canming Zhao Youhao Lu Qianqian sun yan Lyu Baozhen Wang College of Environment Zhejiang University of TechnologyHangzhou 310000China Shaoxing Institute of Zhejiang University of Technology Shaoxing 312000China Shaoxing Ecological and Environmental Monitoring Center of Zhejiang Province Shaoxing 312000China School of Environmental and Chemical Engineering Shanghai UniversityShanghai 200444China Green Intelligence Environmental School Yangtze Normal UniversityChongqing 408100China

Methane(CH_(4))is the second greenhouse gas and has a profound impact on global climate change due to its high global warming potential and *** 2022,the CH_(4)concentration was approximately 1.9 ppm,which was 264%of the pre-industrial *** spatiotemporal distribution of CH_(4)was investigated by a portable CH_(4)detector on an unmanned aerial vehicle and electric bicycles in Shaoxing,a city situated in the yangtze River Delta,*** vertical distribution revealed CH_(4)concentration generally decreased slowly with ***,the inversion condition and low atmospheric boundary layer height(ABLH)leaded to the enhancement of CH_(4)with *** highest CH_(4)concentration(2.2±0.1 ppm,n=1428)was observed in winter and the lowest(2.0±0.2 ppm,n=1530)in *** the daily variation,CH_(4)concentration peaked at 5:00 local time(LT)and reached its lowest level at 14:00 LT,which was attributed to the daily variation of ABLH,lowest in the early morning and highest in the *** urban areas,CH_(4)concentrations showed higher levels near restaurants,natural gas stations and sewerage well,with a maximum value of 13.1 ppm,which was caused by CH_(4)emission and natural gas leakage from these *** annual CH_(4)emission in Shaoxing were estimated to be approximately 69 ton/(km^(2)·year)by the mass balance *** with other cities in the world,the CH_(4)emission is in higher level which imply some control measures should be conducted to reduce CH_(4)emission in Shaoxing.

关键词： Portable CH_(4)detector Spatiotemporal variation Annual CH_(4)emission Unmanned aerial vehicle

A single-pixel elemental imaging method using neutron-induced gamma-ray activation

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Nuclear Science and Techniques 2025年第1期36卷 1-12页

作者： Can Cheng Yong-Ji Xie Xun-Rong Xia jia-Yu Gu Dong Zhao Yi-Ze Chen Ai-Yun sun Xu-Wen Liang Wen-Bao jia Da-Qian Hei Department of Ionizing Radiation and Medical Engineering Jiangsu Institute of MetrologyNanjing 210023China Institute of Nuclear Analytical Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China China Nuclear Power Engineering Co. LtdBeijing 100840China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

Neutron-induced gamma-ray imaging is a spectroscopic technique that uses characteristic gamma rays to infer the elemental distribution of an ***,this technique requires the use of large facilities to supply a high neutron flux and a time-consuming detection procedure involving direct collimating *** this study,a new method based on low neutron flux was proposed.A single-pixel gamma-ray detector combined with random pattern gamma-ray masks was used to measure the characteristic gamma rays emitted from the *** of the elemental distribution in the sample,comprising 30×30 pixels,were reconstructed using the maximum-likelihood expectation-maximization *** results demonstrate that the elemental imaging of the sample can be accurately determined using this *** proposed approach,which eliminates the need for high neutron flux and scanning measurements,can be used for in-field imaging applications.

关键词： Elemental imaging Neutron-induced gamma-ray activation Single-pixel imaging

Cu/TiO_(2)adsorbents modified by air plasma for adsorption-oxidation of H_(2)S

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Journal of Environmental Sciences 2025年第2期148卷 476-488页

作者： Yongqi yan Xinyu yang Ping Ning Chi Wang Xin sun Fei Wang Peng Gao Kai Li Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500China National-Regional Engineering Center for Recovery of Waste Gases from Metallurgical and Chemical Industries Kunming University of Science and TechnologyKunming 650500China Faculty of Chemical Engineering Kunming University of Science and TechnologyKunming 650500China City College Kunming University of Science and TechnologyKunming 650500China

In this study,non-thermal plasma(NTP)was employed to modify the Cu/TiO_(2)adsorbent to efficiently purify H_(2)S in low-temperature and micro-oxygen *** effects of Cu loading amounts and atmospheres of NTP treatment on the adsorption-oxidation performance of the adsorbents were *** NTP modification successfully boosted the H_(2)S removal capacity to varying degrees,and the optimized adsorbent treated by air plasma(Cu/TiO_(2)-Air)attained the best H_(2)S breakthrough capacity of 113.29 mg H_(2)S/gadsorbent,which was almost 5 times higher than that of the adsorbent without NTP *** studies demonstrated that the superior performance of Cu/TiO_(2)-Air was attributed to increased mesoporous volume,more exposure of active sites(CuO)and functional groups(amino groups and hydroxyl groups),enhanced Ti-O-Cu interaction,and the favorable ratio of active oxygen ***,the X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)results indicated the main reason for the deactivationwas the consumption of the active components(CuO)and the agglomeration of reaction products(CuS and SO_(4)^(2−))occupying the active sites on the surface and the inner pores of the adsorbents.

关键词： Non-thermal plasma(NTP) Surface modification Simultaneous adsorption-oxidation Cu/TiO_(2)(TiO_(2)loaded with copper) H_(2)S