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Modeling of the Separation Bubble on Cambered Airfoils Utilizing Modified Parameters in a Transition Model
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作者 Eren Anıl Sezer Muhammer Ayvazoğlu +4 位作者 Muhammed Hatem Sinem Keskin MustafaÖzden Mustafa Serdar Genç Halil Hakan Açıkel 《Computer Modeling in Engineering & Sciences》 2026年第3期635-662,共28页
Separation bubbles forming on airfoils significantly influence aerodynamic behavior,particularly at low Reynolds numbers,making their accurate prediction a critical challenge in transition modelling.This study investi... Separation bubbles forming on airfoils significantly influence aerodynamic behavior,particularly at low Reynolds numbers,making their accurate prediction a critical challenge in transition modelling.This study investigates numerical modeling of a separation bubble and the effects of airfoil thickness and camber variation on the formation of the bubble dynamics at low Reynolds numbers.The numerical results were compared with the experimental results obtained from surface pressure distribution measurements,oil flow visualisation,and surface shear measurements to analyse the detailed flow behavior.The combination of pressure and flow visualisation techniques provided complementary insights,enabling a detailed characterisation of bubble formation.The results reveal that both the thickness and camber of the airfoil significantly influence the location,length,and stability of the bubble.At low Reynolds number flows(Re=0.5×10^(5)),particularly for highly cambered profiles,closer to the leading edge,separation and long bubbles were observed.As the Reynolds number increased,the separation point shifted to the leading edge,and reattachment became more likely.In numerical studies,transition models can accurately model the bubble initiation point;however,they often fail to model the bubble reattachment points accurately.This is due to the inadequacy of models that use empirical expressions for turbulence modelling,particularly in low Reynolds number flows,in their viscous modelling.In this study,it was concluded that transition onset terms,which specifically affect bubble formation,should be modified for more accurate modeling. 展开更多
关键词 Bubble dynamics transition modeling cambered airfoil transition onset
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选区激光熔化成形Ti175合金的高温静态球化机制
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作者 王彦伟 赵子博 +6 位作者 张健 张博华 张帅 李晨旭 王中 刘征 刘玉敬 《热加工工艺》 北大核心 2026年第5期154-160,共7页
研究系统揭示了选区激光熔化(selective laser melting,SLM)成形的Ti175高温钛合金在热处理过程中熔池中心的结构演变特征与熔池边缘晶粒的静态球化机制。结果表明,SLM成形过程中熔池中心与边缘区域因冷却速率差异分别形成粗大板条α&#... 研究系统揭示了选区激光熔化(selective laser melting,SLM)成形的Ti175高温钛合金在热处理过程中熔池中心的结构演变特征与熔池边缘晶粒的静态球化机制。结果表明,SLM成形过程中熔池中心与边缘区域因冷却速率差异分别形成粗大板条α'马氏体与细针状α'马氏体,其中熔池边缘晶粒取向因高密度位错和残余应力累积呈现杂乱分布的特征。经960℃×1h炉冷热处理后,熔池边缘区域晶粒通过残余应力释放驱动位错重组与亚晶界演化机制实现静态球化,晶粒内部取向差降至3°以下;而熔池中心因初始位错密度和残余应力水平较低,主要发生Ostwald熟化主导的板条粗化,保留原始板条形态。球化过程分为曲率驱动的端部迁移和残余应力驱动的亚晶界演化两阶段,其本质为低能位错结构形成与界面能最小化的动态平衡。本研究阐明了残余应力梯度与温度场作用下的组织调控规律,为SLM钛合金构件性能优化提供了理论依据。 展开更多
关键词 Ti175合金 静态球化 选区激光熔化 高温钛合金
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MXene‑Ti_(3)C_(2)T_(x)‑Based Neuromorphic Computing:Physical Mechanisms,Performance Enhancement,and Cutting‑Edge Computing 被引量:1
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作者 Kaiyang Wang Shuhui Ren +3 位作者 Yunfang Jia Xiaobing Yan Lizhen Wang Yubo Fan 《Nano-Micro Letters》 2025年第11期251-302,共52页
Neuromorphic devices have shown great potential in simulating the function of biological neurons due to their efficient parallel information processing and low energy consumption.MXene-Ti_(3)C_(2)T_(x),an emerging two... Neuromorphic devices have shown great potential in simulating the function of biological neurons due to their efficient parallel information processing and low energy consumption.MXene-Ti_(3)C_(2)T_(x),an emerging twodimensional material,stands out as an ideal candidate for fabricating neuromorphic devices.Its exceptional electrical performance and robust mechanical properties make it an ideal choice for this purpose.This review aims to uncover the advantages and properties of MXene-Ti_(3)C_(2)T_(x)in neuromorphic devices and to promote its further development.Firstly,we categorize several core physical mechanisms present in MXene-Ti_(3)C_(2)T_(x)neuromorphic devices and summarize in detail the reasons for their formation.Then,this work systematically summarizes and classifies advanced techniques for the three main optimization pathways of MXene-Ti_(3)C_(2)T_(x),such as doping engineering,interface engineering,and structural engineering.Significantly,this work highlights innovative applications of MXene-Ti_(3)C_(2)T_(x)neuromorphic devices in cutting-edge computing paradigms,particularly near-sensor computing and in-sensor computing.Finally,this review carefully compiles a table that integrates almost all research results involving MXene-Ti_(3)C_(2)T_(x)neuromorphic devices and discusses the challenges,development prospects,and feasibility of MXene-Ti_(3)C_(2)T_(x)-based neuromorphic devices in practical applications,aiming to lay a solid theoretical foundation and provide technical support for further exploration and application of MXene-Ti_(3)C_(2)T_(x)in the field of neuromorphic devices. 展开更多
关键词 Neuromorphic device MXene-Ti_(3)C_(2)T_(x) Physical mechanisms Performance improvement Cutting-edge computing
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Novel Active Contour Model for Image Segmentation Based on Local Fuzzy Gaussian Distribution Fitting
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作者 Quang Tung Thieu Marie Luong +2 位作者 Jean-Marie Rocchisani Nguyen Linh-Trung Emmanuel Viennet 《Journal of Electronic Science and Technology》 CAS 2012年第2期113-118,共6页
A novel active contour model is proposed, which incorporates local information distributions in a fuzzy energy function to effectively deal with the intensity inhomogeneity. Moreover, the proposed model is convex with... A novel active contour model is proposed, which incorporates local information distributions in a fuzzy energy function to effectively deal with the intensity inhomogeneity. Moreover, the proposed model is convex with respect to the variable which is used for extracting the contour. This makes the model independent on the initial condition and suitable for an automatic segmentation. Furthermore, the energy function is minimized in a computationally efficient way by calculating the fuzzy energy alterations directly. Experiments are carried out to prove the performance of the proposed model over some existing methods. The obtained results confirm the efficiency of the method. 展开更多
关键词 Active contour energy minimization fuzzy energy function local information medical image segmentation.
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Shallow Water Waves with Surface Tension by Laplace–Adomian Decomposition
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作者 Oswaldo Gonzalez-Gaxiola Yakup Yildirim +1 位作者 Luminita Moraru Anjan Biswas 《Fluid Dynamics & Materials Processing》 2025年第9期2273-2287,共15页
This study presents a numerical investigation of shallow water wave dynamics with particular emphasis on the role of surface tension.In the absence of surface tension,shallow water waves are primarily driven by gravit... This study presents a numerical investigation of shallow water wave dynamics with particular emphasis on the role of surface tension.In the absence of surface tension,shallow water waves are primarily driven by gravity and are well described by the classical Boussinesq equation,which incorporates fourth-order dispersion.Under this framework,solitary and shock waves arise through the balance of nonlinearity and gravity-induced dispersion,producing waveforms whose propagation speed,amplitude,and width depend largely on depth and initial disturbance.The resulting dynamics are comparatively smoother,with solitary waves maintaining coherent structures and shock waves displaying gradual transitions.When surface tension is incorporated,however,the dynamics become significantly richer.Surface tension introduces additional sixth-order dispersive terms into the governing equation,extending the classical model to the sixth-order Boussinesq equation.This higher-order dispersion modifies the balance between nonlinearity and dispersion,leading to sharper solitary wave profiles,altered shock structures,and a stronger sensitivity of wave stability to parametric variations.Surface tension effects also change the scaling laws for wave amplitude and velocity,producing conditions where solitary waves can narrow while maintaining large amplitudes,or where shock fronts steepen more rapidly compared to the tension-free case.These differences highlight how capillary forces,though often neglected in macroscopic wave studies,play a fundamental role in shaping dynamics at smaller scales or in systems with strong fluid–interface interactions.The analysis in this work is carried out using the Laplace-Adomian Decomposition Method(LADM),chosen for its efficiency and accuracy in solving high-order nonlinear partial differential equations.The numerical scheme successfully recovers both solitary and shock wave solutions under the sixth-order model,with error analysis confirming remarkably low numerical deviations.These results underscore the robustness of the method while demonstrating the profound contrast between shallow water wave dynamics without and with surface tension. 展开更多
关键词 Boussinesq equation shallow water waves surface tension Laplace–Adomian Decomposition Method
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A Concept of Dynamically Reconfigurable Real-time Vision System for Autonomous Mobile Robotics 被引量:3
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作者 Aymeric De Cabrol Thibault Garcia +1 位作者 Patrick Bonnin Maryline Chetto 《International Journal of Automation and computing》 EI 2008年第2期174-184,共11页
This paper describes specific constraints of vision systems that are dedicated to be embedded in mobile robots. If PC-based hardware architecture is convenient in this field because of its versatility, flexibility, pe... This paper describes specific constraints of vision systems that are dedicated to be embedded in mobile robots. If PC-based hardware architecture is convenient in this field because of its versatility, flexibility, performance, and cost, current real-time operating systems are not completely adapted to long processing with varying duration, and it is often necessary to oversize the system to guarantee fail-safe functioning. Also, interactions with other robotic tasks having more priority are difficult to handle. To answer this problem, we have developed a dynamically reconfigurable vision processing system, based on the innovative features of Cleopatre real-time applicative layer concerning scheduling and fault tolerance. This framework allows to define emergency and optional tasks to ensure a minimal quality of service for the other subsystems of the robot, while allowing to adapt dynamically vision processing chain to an exceptional overlasting vision process or processor overload. Thus, it allows a better cohabitation of several subsystems in a single hardware, and to develop less expensive but safe systems, as they will be designed for the regular case and not rare exceptional ones. Finally, it brings a new way to think and develop vision systems, with pairs of complementary operators. 展开更多
关键词 Real-time vision dynamic reconfiguration embedded systems ROBUSTNESS real-time operating system
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MXene-Derived Defect-Rich TiO2@rGO as High-Rate Anodes for Full Na Ion Batteries and Capacitors 被引量:3
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作者 Yongzheng Fang Yingying Zhang +9 位作者 Chenxu Miao Kai Zhu Yong Chen Fei Du Jinling Yin Ke Ye Kui Cheng Jun Yan Guiling Wang Dianxue Cao 《Nano-Micro Letters》 SCIE EI CAS CSCD 2020年第10期53-68,共16页
Sodium ion batteries and capacitors have demonstrated their potential applications for next-generation low-cost energy storage devices.These devices’s rate ability is determined by the fast sodium ion storage behavio... Sodium ion batteries and capacitors have demonstrated their potential applications for next-generation low-cost energy storage devices.These devices’s rate ability is determined by the fast sodium ion storage behavior in electrode materials.Herein,a defective TiO2@reduced graphene oxide(M-TiO2@rGO)self-supporting foam electrode is constructed via a facile MXene decomposition and graphene oxide self-assembling process.The employment of the MXene parent phase exhibits distinctive advantages,enabling defect engineering,nanoengineering,and fluorine-doped metal oxides.As a result,the M-TiO2@rGO electrode shows a pseudocapacitance-dominated hybrid sodium storage mechanism.The pseudocapacitance-dominated process leads to high capacity,remarkable rate ability,and superior cycling performance.Significantly,an M-TiO2@rGO//Na3 V2(PO4)3 sodium full cell and an M-TiO2@rGO//HPAC sodium ion capacitor are fabricated to demonstrate the promising application of M-TiO2@rGO.The sodium ion battery presents a capacity of 177.1 mAh g-1 at 500 mA g-1 and capacity retention of 74%after 200 cycles.The sodium ion capacitor delivers a maximum energy density of 101.2 Wh kg-1 and a maximum power density of 10,103.7 W kg-1.At 1.0 A g-1,it displays an energy retention of 84.7%after 10,000 cycles. 展开更多
关键词 MXene-Ti2CTx Vacancy oxygen SELF-SUPPORTING TiO2 anodes Sodium ion battery and capacitor
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GIS-based landslide susceptibility modeling:A comparison between fuzzy multi-criteria and machine learning algorithms 被引量:11
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作者 Sk Ajim Ali Farhana Parvin +7 位作者 Jana Vojteková Romulus Costache Nguyen Thi Thuy Linh Quoc Bao Pham Matej Vojtek Ljubomir Gigović Ateeque Ahmad Mohammad Ali Ghorbani 《Geoscience Frontiers》 SCIE CAS CSCD 2021年第2期857-876,共20页
Hazards and disasters have always negative impacts on the way of life.Landslide is an overwhelming natural as well as man-made disaster that causes loss of natural resources and human properties throughout theworld.Th... Hazards and disasters have always negative impacts on the way of life.Landslide is an overwhelming natural as well as man-made disaster that causes loss of natural resources and human properties throughout theworld.The present study aimed to assess and compare the prediction efficiency of different models in landslide susceptibility in the Kysuca river basin,Slovakia.In this regard,the fuzzy decision-making trial and evaluation laboratory combining with the analytic network process(FDEMATEL-ANP),Naïve Bayes(NB)classifier,and random forest(RF)classifier were considered.Initially,a landslide inventory map was produced with 2000 landslide and nonlandslide points by randomly dividedwith a ratio of 70%:30%for training and testing,respectively.The geospatial database for assessing the landslide susceptibility was generated with the help of 16 landslide conditioning factors by allowing for topographical,hydrological,lithological,and land cover factors.The ReliefF methodwas considered for determining the significance of selected conditioning factors and inclusion in the model building.Consequently,the landslide susceptibility maps(LSMs)were generated using the FDEMATEL-ANP,Naïve Bayes(NB)classifier,and random forest(RF)classifier models.Finally,the area under curve(AUC)and different arithmetic evaluation were used for validating and comparing the results and models.The results revealed that random forest(RF)classifier is a promising and optimum model for landslide susceptibility in the study area with a very high value of area under curve(AUC=0.954),lower value of mean absolute error(MAE=0.1238)and root mean square error(RMSE=0.2555),and higher value of Kappa index(K=0.8435)and overall accuracy(OAC=92.2%). 展开更多
关键词 Landslide susceptibility modeling Geographic information system Fuzzy DEMATEL Analytic network process Naïve Bayes classifier Random forest classifier
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Diagnostic efficacy of fecal-based miR-92a for advanced colorectal neoplasia:a prospective multicenter screening trial
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作者 Jia-Chen Wang Li Zhao +31 位作者 Xiang-Yang Yu Ting-Ping Wu Chang-Fa Xia Ju-Fang Shi Hui He Zhi-Qi Chen Dan Shi Han Xue Qi Ao Shu-Ping Liao Zhang-Qiang Zheng Qiong-Fang Huang Lin Li Sui-Ling Lin Ying-Xue Li Wen-Long Hu Ji Peng Lin Lei Mao-Mao Cao Fan Yang Xin-Xin Yan Si-Yi He Meng-Di Cao Shao-Li Zhang Yi Teng Qian-Ru Li Nuo-Pei Tan Hao-Yang Yu Hong-Hui Cheng Xi-Mo Wang Wei-Qing Wu Wan-Qing Chen 《Military Medical Research》 2025年第11期1722-1734,共13页
Background:More efficacious,noninvasive screening methods are needed for advanced colorectal neoplasia.miR-92a is a reliable and reproducible biomarker for early colorectal cancer detection in stool samples.We compare... Background:More efficacious,noninvasive screening methods are needed for advanced colorectal neoplasia.miR-92a is a reliable and reproducible biomarker for early colorectal cancer detection in stool samples.We compared the diagnostic efficacies of miR-92a,immunochemical fecal occult blood testing(FIT),and their combination(FIT+miR-92a)in a prospective multicenter screening trial.Methods:Overall,16,240 participants aged 30-75 years were enrolled between April 1,2021,and December 31,2023.A total of 15,586 participants returned samples available for both FIT and miR-92a tests.All those with positive,and a random selection of those with negative screening tests were recommended to undergo colonoscopy.Follow-ups were performed until participants completed the colonoscopic examination.A total of 1401 screen-positive and 2079 randomly selected screen-negative individuals completed colonoscopies.Primary outcomes included sensitivity,number needed to screen(NNS),Youden index and receiver operating characteristic area under the curve(AUC)for advanced adenomas and colorectal cancer[advanced neoplasia(AN)]for each screening modality in the diagnostic performance analysis.Results:Colonoscopy was performed in 3480 individuals.The colonoscopy compliance rate was 47.8%for screen-positive individuals.The sensitivity of miR-92a vs.FIT for AN was 70.9%vs.54.3%(P<0.001),NNS was 24.7 vs.32.2(P=0.001),Youden index was 47.9%vs.35.0%(P<0.001),AUC was 0.74 vs.0.67(P=0.010).FIT+miR-92a had a sensitivity of 85.4%,an NNS of 20.5,a Youden index of 47.9%and an AUC of 0.74 for AN.Conclusions:For AN screening,miR-92a demonstrated better sensitivity,NNS,Youden index and AUC as compared with FIT.Compared with FIT,using miR-92a appears to be more efficient for population-based screening programs.Screening sensitivity for AN can be further enhanced if conditionally used in combination with FIT.Trial registration Chinese Clinical Trial Registration Number:ChiCTR2200065415. 展开更多
关键词 Advanced neoplasia Colorectal cancer Immunochemical fecal occult blood testing miR-92a SCREENING
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Spatial Modeling of Soil Lime Requirements with Uncertainty Assessment Using Geostatistical Sequential Indicator Simulation
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作者 Jussara de Oliveira Ortiz Carlos Alberto Felgueiras +2 位作者 Eduardo Celso Gerbi Camargo Camilo Daleles Rennó Manoel Jimenez Ortiz 《Open Journal of Soil Science》 2017年第7期133-148,共16页
This work presents and analyses a geostatistical methodology for spatial modelling of Soil Lime Requirements (SLR) considering punctual samples of Cation Exchange Capacity (CEC) and Base Saturation (BS) soil propertie... This work presents and analyses a geostatistical methodology for spatial modelling of Soil Lime Requirements (SLR) considering punctual samples of Cation Exchange Capacity (CEC) and Base Saturation (BS) soil properties. Geostatistical Sequential Indicator Simulation is used to draw realizations from the joint uncertainty distributions of the CEC and the BS input variables. The joint distributions are accomplished applying the Principal Component Analyses (PCA) approach. The Monte Carlo method for handling error propagations is used to obtain realization values of the SLR model which are considered to compute and store statistics from the output uncertainty model. From these statistics, it is obtained predictions and uncertainty maps that represent the spatial variation of the output variable and the propagated uncertainty respectively. Therefore, the prediction map of the output model is qualified with uncertainty information that should be used on decision making activities related to the planning and management of environmental phenomena. The proposed methodology for SLR modelling presented in this article is illustrated using CEC and BS input sample sets obtained in a farm located in Ponta Grossa city, Paraná state, Brazil. 展开更多
关键词 SPATIAL Modeling of SOIL Attributes INDICATOR GEOSTATISTICS Joint Simulation Principal Component ANALYSES SPATIAL UNCERTAINTY ANALYSES
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Measurement of mouse liver glutathione S-transferase activity by the integrated method 被引量:10
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作者 廖飞 李甲初 +2 位作者 康格非 曾昭淳 左渝萍 《Journal of Medical Colleges of PLA(China)》 CAS 2003年第5期295-300,共6页
Objective: The integrated method was investigated to measure Vm/Km of mouse liver glutathione S-transfer-ase (GST) activity on GSH and 7-Cl-4-nitrobenzofurazozan. Methods: Presetting concentration of one substrate twe... Objective: The integrated method was investigated to measure Vm/Km of mouse liver glutathione S-transfer-ase (GST) activity on GSH and 7-Cl-4-nitrobenzofurazozan. Methods: Presetting concentration of one substrate twenty-fold above the other's and taking maximum product absorbance Am as parameter while Km as constant, Vm/Km was obtained by nonlinear fitting of GST reaction curve to the integrated Michaelis-Menten equation In [Am/(Am -Ai)] + Ai/ ( ξ× Km ) = ( Vm/Km )×ti (1). Results: Vm/Km for GST showed slight dependence on initial substrate concentration and data range, but it was resistant to background absorbance, error in reaction origin and small deviation in presetting Km. Vm/Km was proportional to the amount of GST with upper limit higher than that by initial rate. There was close correlation between Vm/Km and initial rate of the same GST. Consistent results were obtained by this integrated method and classical initial rate method for the measurement of mouse liver GST. Conclusion: With the concentration of one substrate twenty-fold above the other's, this integrated method was reliable to measure the activity of enzyme on two substrates , and substrate concentration of the lower one close to its apparent Km was able to be used. 展开更多
关键词 integrated method glutathione S-transferase nonlinear fitting reaction curve predictor variable enzyme activity measurement
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一种新型高冲击韧性钛合金Ti-64S 被引量:2
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作者 文志刚 李献军 +3 位作者 吴月茜 王丽瑛 杨蓉 杨慧丽 《世界有色金属》 2018年第6期278-279,共2页
为满足石油、天然气、海洋等行业开采应用需求,本文在Ti-64(Ti-6Al-4V)钛合金基础上进行成分改型,形成了一种室温拉伸性能与Ti-64合金相当,且冲击韧性明显优于原合金的新型钛合金Ti-64S。投工业化Ti-64及Ti-64S铸锭以相同锻造及挤压工... 为满足石油、天然气、海洋等行业开采应用需求,本文在Ti-64(Ti-6Al-4V)钛合金基础上进行成分改型,形成了一种室温拉伸性能与Ti-64合金相当,且冲击韧性明显优于原合金的新型钛合金Ti-64S。投工业化Ti-64及Ti-64S铸锭以相同锻造及挤压工艺试验了10622mm挤压管材、Φ25mm棒材及35mm×72mm扁方,并进行了室温拉伸、冲击、断裂韧性、硬度等性能测试及比对。结果表明Ti-64S合金冲击韧性及断裂韧性优于Ti-64,强度、硬度与Ti-64相当。改型合金Ti-64S可完全满足石油等行业开采用P110钢级钢材强度及冲击韧性指标要求,实现以钛材替代该级别钢材,从而大大提高设备耐蚀性能,延长设备使用寿命。 展开更多
关键词 冲击韧性 Ti-64S P110钢级
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Novel TINF2 gene mutation in dyskeratosis congenita with extremely short telomeres:A case report
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作者 Verónica Judith Picos-Cárdenas Saúl Armando Beltrán-Ontiveros +7 位作者 JoséAlfonso Cruz-Ramos JoséAlfredo Contreras-Gutiérrez Eliakym Arámbula-Meraz Carla Angulo-Rojo Alma Marlene Guadrón-Llanos Emir Adolfo Leal-León Dora María Cedano-Prieto Juan Pablo Meza-Espinoza 《World Journal of Clinical Cases》 SCIE 2022年第33期12440-12446,共7页
BACKGROUND Dyskeratosis congenita is a rare disease characterized by bone marrow failure and a clinical triad of oral leukoplakia,nail dystrophy,and abnormal skin pigmentation.The genetics of dyskeratosis congenita in... BACKGROUND Dyskeratosis congenita is a rare disease characterized by bone marrow failure and a clinical triad of oral leukoplakia,nail dystrophy,and abnormal skin pigmentation.The genetics of dyskeratosis congenita include mutations in genes involved in telomere maintenance,including TINF2.CASE SUMMARY Here,we report a female patient who presented thrombocytopenia,anemia,reticulate hyperpigmentation,dystrophy in fingernails and toenails,and leukoplakia on the tongue.A histopathological study of the skin showed dyskeratocytes;however,a bone marrow biopsy revealed normal cell morphology.The patient was diagnosed with dyskeratosis congenita,but her family history did not reveal significant antecedents.Whole-exome sequencing showed a novel heterozygous punctual mutation in exon 6 from the TINF2 gene,namely,NM_001099274.1:-c.854delp.(Val285-Alafs*32).An analysis of telomere length showed short telomeres relative to the patient’s age.CONCLUSION The disease in this patient was caused by a germline novel mutation of TINF2 in one of her parents. 展开更多
关键词 Dyskeratosis congenita TINF2 Germline mutation Novel mutation Short telomeres Case report
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NiTi40合金微观组织结构的电子显微学分析 被引量:2
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作者 杜志伟 彭永刚 +4 位作者 韩小磊 张婧 李聪 刘淑凤 徐云培 《中国有色金属学报》 EI CAS CSCD 北大核心 2020年第3期587-594,共8页
采用扫描电子显微分析(SEM)、电子背散射衍射分析(EBSD)、透射电子显微分析(TEM)、高分辨电子显微分析(HRTEM)、高角度环形暗场-扫描透射(HAADF-STEM)等技术手段,对NiTi40(60%Ni+40%Ti,质量分数)合金淬火态样品的微观组织结构进行分析... 采用扫描电子显微分析(SEM)、电子背散射衍射分析(EBSD)、透射电子显微分析(TEM)、高分辨电子显微分析(HRTEM)、高角度环形暗场-扫描透射(HAADF-STEM)等技术手段,对NiTi40(60%Ni+40%Ti,质量分数)合金淬火态样品的微观组织结构进行分析。结果表明:NiTi40合金在950℃、150 min固溶水冷和1050℃、150 min固溶水冷的硬度值相近,为60~61 HRC,但微观组织结构有显著的区别。经950℃固溶水冷后,合金中的粗大第二相主要为NiTi2和Ni3Ti相,还有少量和NiTi2相互伴生的TiC相;经1050℃固溶水冷后,合金中的Ni3Ti相接近完全回溶的,粗大第二相主要为相互伴生的NiTi2及Ti C相。随着固溶温度的升高,合金的晶粒尺寸明显增大,合金晶界处的小晶粒在1050℃固溶时基本消失。经950℃固溶处理,晶内析出相主要为10~20 nm的Ni4Ti3相;经1050℃固溶处理,晶内析出相主要为几十至几百纳米的Ni4Ti3相。 展开更多
关键词 NiTi40合金 固溶处理 电子显微学分析 Ni4Ti3相
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Remote Sensing-based Spatiotemporal Distribution of Grassland Aboveground Biomass and Its Response to Climate Change in the Hindu Kush Himalayan Region 被引量:3
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作者 XU Cong LIU Wenjun +4 位作者 ZHAO Dan HAO Yanbin XIA Anquan YAN Nana ZENG Yuan 《Chinese Geographical Science》 SCIE CSCD 2022年第5期759-775,共17页
The grassland in the Hindu Kush Himalayan(HKH) region is one of the large st and most biodiverse mountain grassland types in the world,and its ecosystem service functions have profound impacts on the sustainable devel... The grassland in the Hindu Kush Himalayan(HKH) region is one of the large st and most biodiverse mountain grassland types in the world,and its ecosystem service functions have profound impacts on the sustainable development of the HKH region.Monitoring the spatiotemporal distribution of grassland aboveground biomass(AGB) accurately and quantifying its response to climate change are indispensable sources of information for sustainably managing grassland ecosystems in the HKH region.In this study,a pure vegetation index model(PVIM) was applied to estimate the long-term dynamics of grassland AGB in the HKH region during 2000-2018.We further quantified the response of grassland AGB to climate change(temperature and precipitation) by partial correlation and variance partitioning analyses and then compared their differences with elevation.Our results demonstrated that the grassland AGB predicted by the PVIM had a good linear relationship with the ground sampling data.The grassland AGB distribution pattern showed a decreasing trend from east to west across the HKH region except in the southern Himalayas.From 2000 to 2018,the mean AGB of the HKH region increased at a rate of 1.57 g/(m~2·yr) and ranged from 252.9(2000) to 307.8 g/m~2(2018).AGB had a positive correlation with precipitation in more than 80% of the grassland,and temperature was positively correlated with AGB in approximately half of the region.The change in grassland AGB was more responsive to the cumulative effect of annual precipitation,while it was more sensitive to the change in temperature in the growing season;in addition,the influence of climate varied at different elevations.Moreover,compared with that of temperature,the contribution of precipitation to grassland AGB change was greater in approximately 60% of the grassland,but the differences in the contribution for each climate factor were small between the two temporal scales at elevations over 2000 m.An accurate assessment of the temporal and spatial distributions of grassland AGB and the quantification of its response to climate change are of great significance for grassland management and sustainable development in the HKH region. 展开更多
关键词 grassland aboveground biomass(AGB) climate change ELEVATION spatiotemporal distribution Hindu Kush Himalayan(HKH)region
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Left bundle branch area pacing:A new era of cardiac resynchronization therapy?
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作者 Carlo Alberto Caruzzo Elia Rigamonti Francesca Romana Scopigni 《World Journal of Cardiology》 2024年第9期542-545,共4页
The recent systematic review and meta-analysis provided a comprehensive focus on the current state of cardiac resynchronization therapy(CRT).The authors determined the feasibility of physiological left bundle branch a... The recent systematic review and meta-analysis provided a comprehensive focus on the current state of cardiac resynchronization therapy(CRT).The authors determined the feasibility of physiological left bundle branch area pacing(LBBAP)in patients indicated for CRT through a careful analysis of trials.They found that LBBAP was associated with significant reductions in QRS duration,New York Heart Association functional class,B-type natriuretic peptide levels,and pacing thresholds as well as improvements in echocardiographic parameters compared to biventricular pacing. 展开更多
关键词 Left bundle branch pacing Biventricular pacing QRS duration Left ventricular ejection fraction Heart failure
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Correlation of the anisotropic hardening behavior and texture features of cold rolled Zr-4 sheet under uniaxial tension
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作者 Huan Liu Siying Deng +3 位作者 Shuaifeng Chen Hongwu Song Shihong Zhang Ben Wang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第24期111-122,共12页
The strongly anisotropic mechanical behaviors commonly observed in Zr-4 sheets typically lead to inferior formability.In this study,the mechanical behavior and texture evolution of a cold-rolled Zr-4 sheet under uniax... The strongly anisotropic mechanical behaviors commonly observed in Zr-4 sheets typically lead to inferior formability.In this study,the mechanical behavior and texture evolution of a cold-rolled Zr-4 sheet under uniaxial tension in various directions were systematically investigated,and the results showed both anisotropic yielding and hardening behavior in the Zr-4 sheet.The microstructure and texture features revealed by electron backscattered diffraction(EBSD)method indicate that this anisotropic mechanical behavior is closely related to the initial texture and its evolution during plastic deformation.In conjunction with experimental observations,a visco-plastic self-consistent(VPSC)model was employed to quantitatively analyze the relationship between the mechanical anisotropy and the texture features and activation of deformation modes.It was found that the yield anisotropy is affected by the distinct activity of prismaticslip,while the different activities of basalslip and extension twinning(ETW)result in anisotropic hardening.The distinct activation of deformation modes is mainly caused by differences in the evolution of the Schmid factor(SF)and critical resolved shear stress(CRSS)with increasing strain.Additionally,the results prove that the limited twinning activation with a fraction of less than 3%plays a non-negligible role in the hardening behavior during tension along the transverse direction.The latent hardening effect caused by the interaction between prismatic slip and tensile twinning is considered to successfully capture the anisotropic hardening behavior of the Zr-4 sheet.The implementation and insights from the predictions are presented and discussed in this work. 展开更多
关键词 Zr-4 sheet Anisotropic hardening Texture evolution Deformation modes TWINNING
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The new method of prediction on mining subsidence and deformation
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作者 姜岩 张玉卓 +2 位作者 宋振骐 A.SROKA 田茂义 《Journal of Coal Science & Engineering(China)》 2001年第1期25-29,共5页
A new probability function of mining overlying strata and subsidence is put forward that has a general statistical significance based on the ideal stochastic medium displacement model. It establishes a new system of p... A new probability function of mining overlying strata and subsidence is put forward that has a general statistical significance based on the ideal stochastic medium displacement model. It establishes a new system of prediction on horizontal mining subsidence and deformation, which gives a new method for prediction on mining subsidence and deformation. 展开更多
关键词 stochastic medium subsidence probability mining subsidence prediction method
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Physico-Chemical and Microbiological Analysis of Water of the “Presa De Los Patos” in the Desierto De Los Leones National Park, Mexico
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作者 Luis Raúl Gutiérrez-Lucas Luz María Chávez-Ramírez Leticia Arregui 《Advances in Biological Chemistry》 2017年第2期122-138,共17页
The Desierto de los Leones National Park is a place that features recreational activities for residents and visitors to Mexico City. The Presa de los Patos (Ducks Dam) is one of the many bodies of water that are prese... The Desierto de los Leones National Park is a place that features recreational activities for residents and visitors to Mexico City. The Presa de los Patos (Ducks Dam) is one of the many bodies of water that are present in the park. By means of physico-chemical and microbiological analysis, it was determined that the water of the Presa de los Patos cannot be considered potable. The pH range was between 5.5 - 5.9. The turbidity exceeded the values established in the standards (10.7 - 32.3 Nephelometric Turbidity Units (NTU’s)). Chemical Oxygen Demand (COD) showed that large amounts of oxygen are needed to oxidize organic matter (106 - 450 mg/L). The amount of coliforms and fecal coliforms exceeds the values established by the standards used (total coliforms 98 - 956 Colony Forming Units (CFU’s), fecal coliforms 78 - 807 CFU’s). Five bacterial genera (Escherichia coli, Pseudomona, Klebsiella, Shigella and Salmonella) were isolated and identified. Most of the bacteria isolated were resistant to ampicillin (90%), while 25% were resistant to ciprofloxacin. The water consumption of the Presa de los Patos is a great risk for the habitants and visitors of the park. 展开更多
关键词 WATER PHYSICO-CHEMICAL MICROBIOLOGICAL Antimicrobial Resistance ANTIBIOTICS
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Ti-O Magnéli相氧化物的性质、制备与应用研究进展 被引量:1
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作者 霍玲玲 乔丹 +2 位作者 王义智 李钒 黄一兵 《材料导报》 EI CAS CSCD 北大核心 2017年第11期29-37,58,共10页
Ti-O Magnéli相氧化物因具有特殊的结构和性质自发现以来就备受关注。Ti-O Magnéli相氧化物优良的电子导电性、稳定性以及耐腐蚀性使得其在电化学领域应用广泛。综述了Ti-O Magnéli相氧化物的组成、结构、性质及其主要... Ti-O Magnéli相氧化物因具有特殊的结构和性质自发现以来就备受关注。Ti-O Magnéli相氧化物优良的电子导电性、稳定性以及耐腐蚀性使得其在电化学领域应用广泛。综述了Ti-O Magnéli相氧化物的组成、结构、性质及其主要的制备方法,并总结归纳了该材料的主要应用。提供了Ti-O Magnéli相氧化物未来合成与应用研究的方向。 展开更多
关键词 Ti-O Magnéli相 电子导电氧化物 材料制备 电极特性
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