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Low temperature quasi-superplasticity of ZK60 alloy prepared by reciprocating extrusion

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Transactions of Nonferrous Metals Society of China 2012年第2期22卷 255-261页

作者：杨文朋郭学锋杨凯军西安理工大学材料科学与工程学院西安710048 河南理工大学材料科学与工程学院焦作454003

Fine-grained ZK60 alloy was prepared by 2-pass reciprocating extrusion, and the low temperature superplasticity was conducted in a temperature range from 443 to 523 K and an initial strain rate ranging from 3.3×10^-4 to 3.3×10-2^s^-1. The results show that the alloy has an equiaxed grain structure with an average grain size of about 5.0μm, and the sizes of broken secondary particles and precipitates are no more than 175 and 50 nm, respectively. The alloy exhibits quasi-superplasticity with a maximum elongation of 270% at 523 K and an initial strain rate of 3.3×10^-4 s^-1. The strain rate sensitivity m is less than 0.2 at 443 and 473 K, and it is 0.42 at 523 K. The apparent activation energies at temperature below 473 K and at 523 K are less than 63.2 and 110.6 kJ/mol, respectively At temperature below 473 K, mainly intragranular sliding contributes to superplastic flow. At 523 K, grain boundary sliding is the dominant deformation mechanism, and dislocation creep controlled by grain boundary diffusion is considered to be the main accommodation mechanism.

关键词： ZK60 Mg alloy reciprocating extrusion quasi-superplasticity intragranular sliding grain boundary sliding

Structure design and coordinated motion analysis of bionic crocodile robot

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Biomimetic Intelligence & Robotics 2024年第2期4卷 50-62页

作者： jun Wang Jingya Zheng Yuhang Zhao kai yang School of Information and Control Engineering China University of Mining and TechnologyXuzhou 221116China

Crocodiles,one of the oldest and most resilient species on Earth,have demonstrated remarkable locomotor abilities both on land and in water,evolving over millennia to adapt to diverse *** this study,we draw inspiration from crocodiles and design a highly biomimetic crocodile robot equipped with multiple degrees of freedom and articulated trunk *** design is based on comprehensive analysis of the structural and motion characteristics of real *** bionic crocodile robot has a problem of limb-torso incoordination during *** solve this problem,we used the D-H method for both forward and inverse kinematics analysis of the robot's legs and *** a series of simulation experiments,we investigated the robot's motion stability,fault tolerance,and adaptability to environments in two motor patterns:with and without spine and tail *** experimental results show that the bionic crocodile robot exhibits superior motion performance when the spine and tail cooperate with the *** study not only demonstrates the potential of biomimicry in robotics but also underscores the significance of understanding how nature's designs can inform and enhance technological innovations.

关键词： Bionic crocodile robot Kinematic modeling Motion simulation Multipart coordination

Differential bonding behaviors of sodium/potassium-ion storage in sawdust waste carbon derivatives

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Chinese Chemical Letters 2024年第4期35卷 496-501页

作者： jun-Ming Cao kai-yang Zhang Jia-Lin yang Zhen-Yi Gu Xing-Long Wu MOE Key Laboratory for UV Light-Emitting Materials and Technology Northeast Normal UniversityChangchun 130024China Department of Chemistry Northeast Normal UniversityChangchun 130024China

Sodium-ion batteries(SIBs) and potassium-ion batteries(PIBs) are the most promising alternatives to lithium-ion batteries, and thus have drawn intensive research attention. Porous carbon materials from different precursors have been widely used as anode materials owing to their compatible storage effectiveness of both larger radii sodium and potassium ions. However, the differential bonding behaviors of Na and K ions with porous carbon-based anode are the significant one worth investigating, which could provide a clean picture of alkali ions storage mechanism. Therefore, in this work, we prepare a porous carbon network derived from sawdust(SDC) wastes, to further analyze the differences on sodium and potassium ions storage behaviors in terms of bond-forming process. It is found that, as-prepared SDC anodes could deliver stable sodium and potassium storage capacities, however, there are notable distinctions in terms of electrochemical behaviors and diffusion processes. By virtue of ex-situ XRD and Raman spectroscopy, the phase transition reaction of potassium ions could be well-observed, and the results shows that the multiple intercalated compounds was formed in SDC network during ions insertion, further resulting in slower diffusion kinetics and larger resistance compared to non-bonded process of sodium ions storage. This study provides more insights into the differences between sodium and potassium ions storage, as well as the energy storage mechanism of porous carbon as anodes for secondary batteries.

关键词： Porous carbon Sodium-ion storage Potassium-ion storage Bonding behaviors Batteries

A Survey on an Emerging Safety Challenge for Autonomous Vehicles:Safety of the Intended Functionality

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Engineering 2024年第2期33卷 17-34页

作者： Hong Wang Wenbo Shao Chen Sun kai yang Dongpu Cao jun Li Tsinghua Intelligent Vehicle Design and Safety Research Institute School of Vehicle and MobilityTsinghua UniversityBeijing 100084China CogDrive Lab Department of Mechanical and Mechatronics EngineeringUniversity of WaterlooWaterlooON N2L3G1Canada College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China

As the complexity of autonomous vehicles(AVs)continues to increase and artificial intelligence algorithms are becoming increasingly ubiquitous,a novel safety concern known as the safety of the intended functionality(SOTIF)has emerged,presenting significant challenges to the widespread deployment of *** focuses on issues arising from the functional insufficiencies of the AVs’intended functionality or its implementation,apart from conventional safety *** the systems engineering standpoint,this study offers a comprehensive exploration of the SOTIF landscape by reviewing academic research,practical activities,challenges,and perspectives across the development,verification,validation,and operation *** research encompasses system-level SOTIF studies and algorithm-related SOTIF issues and ***,it encapsulates practical SOTIF activities undertaken by corporations,government entities,and academic institutions spanning international and Chinese contexts,focusing on the overarching methodologies and practices in different ***,the paper presents future challenges and outlook pertaining to the development,verification,validation,and operation phases,motivating stakeholders to address the remaining obstacles and challenges.

关键词： Safety of the intended functionality Autonomous vehicles Artificial intelligence Uncertainty Verification Validation

KLF4 Inhibits the Activation of Human Hepatic Stellate Cell In Vitro

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Current Medical Science 2024年第3期44卷 512-518页

作者： Xing-yu yang Zhe CHEN jun TAN Yin-kai XUE Hai ZHENG Department of Emergency Surgery Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China Department of Thoracic Surgery The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an710061China Department of Thoracic Surgery Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China

Objective Hepatic stellate cells(HSCs)play a crucial role in liver ***-stage liver fibrosis is reversible and intimately associated with the state of ***-like factor 4(KLF4)plays a pivotal role in a wide array of physiological and pathological *** study aimed to investigate the effect of KLF4 on the proliferation,apoptosis and phenotype of quiescent HSCs Methods We designed a KLF4 lentiviral vector and a KLF4 siRNA lentiviral vector,to upregulate and silence KLF4 expression in human HSC LX-2 cells via *** proliferation was assessed using the CCK-8 *** cytometry was used to detect the cell cycle distribution and apoptosis *** blotting was used to determine the levels of some quiescence and activation markers of HSCs Results Overexpression of KLF4 significantly increased the levels of E-cadherin and ZO-1,which are quiescent HSC markers,while significantly decreased the levels of N-cadherin and a-SMA,known activated HSC *** contrast,cell proliferation and apoptosis rates were elevated in LX-2 cells in which KLF4 expression was silenced Conclusion KLF4 inhibits the proliferation and activation of human LX-2 *** might be a key regulatory protein in the maintenance of HSC quiescence and may serve as a target for the inhibition of hepatic fibrosis.

关键词： Kruppel-like factor 4 hepatic stellate cells LX-2 cells liver fibrosis

Machine learning prediction model for gray-level co-occurrence matrix features of synchronous liver metastasis in colorectal cancer

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World Journal of Gastrointestinal Surgery 2024年第6期16卷 1571-1581页

作者： kai-Feng yang Sheng-Jie Li jun Xu Yong-Bin Zheng Department of Gastrointestinal Surgery Renmin Hospital of Wuhan UniversityWuhan 430030Hubei ProvinceChina Department of Gastrointestinal Surgery The First College of Clinical Medical ScienceChina Three Gorges UniversityYichang Central People’s HospitalYichang 443008Hubei ProvinceChina

BACKGROUND Synchronous liver metastasis(SLM)is a significant contributor to morbidity in colorectal cancer(CRC).There are no effective predictive device integration algorithms to predict adverse SLM events during the diagnosis of *** To explore the risk factors for SLM in CRC and construct a visual prediction model based on gray-level co-occurrence matrix(GLCM)features collected from magnetic resonance imaging(MRI).METHODS Our study retrospectively enrolled 392 patients with CRC from Yichang Central People’s Hospital from January 2015 to May *** were randomly divided into a training and validation group(3:7).The clinical parameters and GLCM features extracted from MRI were included as candidate *** prediction model was constructed using a generalized linear regression model,random forest model(RFM),and artificial neural network *** operating characteristic curves and decision curves were used to evaluate the prediction *** Among the 392 patients,48 had SLM(12.24%).We obtained fourteen GLCM imaging data for variable screening of SLM prediction *** difference,mean sum,sum entropy,sum variance,sum of squares,energy,and difference variance were listed as candidate variables,and the prediction efficiency(area under the curve)of the subsequent RFM in the training set and internal validation set was 0.917[95%confidence interval(95%CI):0.866-0.968]and 0.09(95%CI:0.858-0.960),*** A predictive model combining GLCM image features with machine learning can predict SLM in *** model can assist clinicians in making timely and personalized clinical decisions.

关键词： Colorectal cancer Synchronous liver metastasis Gray-level co-occurrence matrix Machine learning algorithm Prediction model

Lossless Compression Method for the Magnetic and Helioseismic Imager(MHI)Payload

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Research in Astronomy and Astrophysics 2024年第4期24卷 214-221页

作者： Li-Yue Tong Jia-Ben Lin Yuan-Yong Deng kai-Fan Ji jun-Feng Hou Quan Wang Xiao yang National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Key Laboratory of Solar Activity and Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Yunnan Observatories Chinese Academy of SciencesKunming 650216China

The Solar Polar-orbit Observatory(SPO),proposed by Chinese scientists,is designed to observe the solar polar regions in an unprecedented way with a spacecraft traveling in a large solar inclination angle and a small ***,one of the most significant challenges lies in ultra-long-distance data transmission,particularly for the Magnetic and Helioseismic Imager(MHI),which is the most important payload and generates the largest volume of data in *** this paper,we propose a tailored lossless data compression method based on the measurement mode and characteristics of MHI *** background out of the solar disk is removed to decrease the pixel number of an image under *** predictive coding methods are combined to eliminate the redundancy utilizing the correlation(space,spectrum,and polarization)in data set,improving the compression *** results demonstrate that our method achieves an average compression ratio of *** compression time is also less than the general observation *** method exhibits strong feasibility and can be easily adapted to MHI.

关键词： methods:data analysis techniques:image processing Sun:magnetic fields Sun:photosphere

Ultrafast pulse-dilation framing camera and its application for time-resolved X-ray diagnostic

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Nuclear Science and Techniques 2024年第7期35卷 101-114页

作者： Hou-Zhi Cai Qiu-Yan Luo kai-Xuan Lin Xuan Deng jun-kai Liu kai-Zhi yang Dong Wang Jia-Jie Chen Jia-Heng Wang Jing-Hua Long Li-Hong Niu Yun-Fei Lei Jin-Yuan Liu Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province Shenzhen Key Laboratory of Photonics and BiophotonicsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China

An ultrafast framing camera with a pulse-dilation device,a microchannel plate(MCP)imager,and an electronic imaging system were *** camera achieved a temporal resolution of 10 ps by using a pulse-dilation device and gated MCP imager,and a spatial resolution of 100μm by using an electronic imaging system comprising combined magnetic *** spatial resolution characteristics of the camera were studied both theoretically and *** results showed that the camera with combined magnetic lenses reduced the field curvature and acquired a larger working area.A working area with a diameter of 53 mm was created by applying four magnetic lenses to the ***,the camera was used to detect the X-rays produced by the laser-targeting *** diagnostic results indicated that the width of the X-ray pulse was approximately 18 ps.

关键词： Inertial confinement fusion Plasma diagnostics Framing camera Combined lenses Pulse-dilation

Influences of the Fresh Air Volume on the Removal of Cough-Released Droplets in a Passenger Car of a High-Speed Train Using CFD

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2727-2748页

作者： jun Xu kai Bi Yibin Lu TiantianWang Hang Zhang Zeyuan Zheng Fushan Shi Yaxin Zheng Xiaoying Li Jingping yang CRRC Changchun Railway Vehicles Co. Ltd.Changchun130062China Key Laboratory of Traffic Safety on Track Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha410075China College of Mechanical and Vehicle Engineering Hunan UniversityChangsha410082China

The spread and removal of pollution sources,namely,cough-released droplets in three different areas(front,middle,and rear areas)of a fully-loaded passenger car in a high-speed train under different fresh air flow volume were studied using computational fluid dynamics(CFD)*** addition,the structure of indoor flow fields was also *** results show that the large eddies are more stable and flow faster in the air supply under Mode 2(fresh air volume:2200m3/h)compared to Mode 1(fresh air volume:1100m3/h).By analysing the spreading process of droplets sprayed at different locations in the passenger car and with different particle sizes,the removal trends for droplets are found to be similar under the two air supply ***,when increasing the fresh air flow volume,the droplets in the middle and front areas of the passenger car are removed *** the droplets had dispersed for 60s,Mode 2 exhibited a removal rate approximately 1%–3%higher than Mode 1 for small and medium-sized droplets with diameters of 10 and 50μ*** those in the rear area,the situation is reversed,with Mode 1 slightly surpassing Mode 2 by 1%–3%.For large droplets with a diameter of 100μm,both modes achieved a removal rate of over 96%in all three regions at the 60 *** results can provide guidance for air supply modes of passenger cars of high-speed trains,thus suppressing the spread of virus-carrying droplets and reducing the risk of viral infection among passengers.

关键词： Cough-released pollutants CFD ventilation inside trains supply air volume