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Characterization of high-pressure die-cast hypereutectic Al-Si alloys based on microstructural distribution and fracture morphology

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Journal of Materials Science & Technology 2019年第6期35卷 1099-1107页

作者： X.Y. Jiao J. Wang C.F. liu Z.P. Guo G.D. tong S.L. Ma Y. Bi Y.F. Zhang S.M. Xiong School of Materials Science and Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Automobile Safety and Energy Tsinghua University Beijing China China FAW Foundry Co. Ltd. Changchun 130011. China

The fracture behavior of high-pressure die-cast hypereutectic(HPDC) Al-Si alloys was investigated using a high-resolution laboratory CT and synchrotron X-ray tomography with a particular focus on the influence of HPDC microstructure. Results showed that microstructure of the alloy was mainly comprised of primary silicon particles(PSPs), Al dendrites, Cu-rich phases and pores. Most of the coarse PSPs, Cu-rich phases and pores were located in the center of the specimen. The rapid solidification of HPDC led to a heterogeneous microstructural feature. Elemental Cu was enriched in the frontiers of solid-liquid interface, causing the formation of large size dendritic arms. The pores were formed in the interdendrites which endured high stress intensity under high applied stress. Microcracks were originated from pores and further connected Cu-rich phases causing intergranular fracture. PSPs worked as obstacles causing piling-up dislocations in the phase interface. In the regions where large size of PSPs enriched in, PSPs ruptured rather than debonded from matrix, indicating transgranular fractures of PSPs. Microcracks originated around pores and PSPs tended to converge on the main cracks to decrease the energy required for crack propagation.

关键词： Hypereutectic Al-Si alloy Primary silicon particles Porosity Fracture morphology High pressure die casting

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性发育异常新生儿的临床评价和管理

中国当代儿科杂志 2016年第12期18卷 1313-1318页

作者：刘慧童笑梅北京大学第三医院儿科北京100191

性发育异常/性分化异常(DSD)是患儿染色体核型与性腺表型和(或)性腺的解剖结构不一致,表现为新生儿性别难辨。DSD主要根据染色体核型分为3类:46,XY DSD、46,XX DSD、性染色体DSD。临床上需要结合病史、体格检查、实验室和影像学检查来... 详细信息

性发育异常/性分化异常(DSD)是患儿染色体核型与性腺表型和(或)性腺的解剖结构不一致,表现为新生儿性别难辨。DSD主要根据染色体核型分为3类:46,XY DSD、46,XX DSD、性染色体DSD。临床上需要结合病史、体格检查、实验室和影像学检查来进行新生儿DSD的诊断、综合评估以及明确潜在的病因。性别认定必须在所有诊断评估完成后才能做出。医学社会多因素包括基因型性别(核型)、激素性性别(睾酮、双氢睾酮、肾上腺类固醇系列激素水平)、表现型性别(内外生殖器的外观)、生殖性别(生育的潜能)和父母的感觉乃至社会接受程度和宗教习俗等都会影响DSD患儿的性别认定。一个多学科合作的团队是必需的,患儿家人必须参与到有关性别认定的所有过程中。新生儿医师对于DSD的主要任务在于评估患儿状况及其管理。

关键词：性发育异常评价管理新生儿

Point-of-Care Testing Using Three Dimensional Optical Biosensor Based on Microfluidic Technology

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Journal of Biosciences and Medicines 2016年第12期4卷 56-61页

作者： Chunxiu liu Haoyuan Cai Jian Jia Tianyang Cao tong Li Tianjun Ma Chang liu State Key Laboratory of Transducer Technology Institute of Electronics Chinese Academy of Sciences Beijing China

We have presented a three dimensional optical protein chip that fulfills the demanding for point-of-care diagnostics in terms of ease-of-use (one step assay), miniaturization (5 μl). The artful combination of magnetic nanoparticles on chip and total internal reflection imaging (TIRI) technology permits the sensitive and rapid detection of hs-CRP (high-sensitivity C-reactive protein). The whole test was complete within 10 min using “all in one step” assay with a limit of detection of 0.1 ng/mL hs-CRP. The measuring range for hs-CRP could be extended to 10 ng/mL. The chip can also be used to detect more parameters in blood samples.

关键词： Point-of-Care Testing (POCT) Three Dimensional Optical Chip hs-CRP

Strain Softening and Hardening Behavior in AZ61 Magnesium Alloy

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Journal of Materials Science & Technology 2004年第6期20卷 691-693页

作者： Haitao ZHOU, liufa liu, Qudong WANG, Da LU, Xiaoqin ZENG and Wenjiang DINGNational Engineering Research Center of Light Alloys Net Forming, School of Materials Science and Engineering, Shanghai Jiao tong University, Shanghai 200030, China Ctr. of Light Alloys Net Forming Sch. of Mat. Sci. and Eng. Shanghai Jiaotong Univ. Shanghai 200030 China

The deformation behavior of AZ61 Mg alloy during hot deformation has been investigated in wide temperature and strain rate range by a Gleeble simulator. Specimens are deformed in compression in the temperature range of 523-673 K and at strain rates of 0.001-1 s-1. It is found that the flow curves exhibit a peak and then decrease towards steady-state of classical DRX, which decrease with rising temperature and decreasing strain rate. The deformation behavior of the specimens can be attributed to the occurrence of strain hardening and softening. As stress decreases, the strain hardening rate declines at a fast rate when temperature rises or strain rate decreases. The shapes of θ-σ curves indicate some important features such as subgrain formation, the criticai stress, the peak stress and steady stress. The onset of DRX can be determined by the point of inflection on θ-σ or Inθ-σ curves.

关键词： AZ61 Mg alloy Recrystallization Strain hardening and softening

基于光场幅度动态变化的OCT功能成像原理和应用(特邀)

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激光与光电子学进展 2024年第2期61卷 248-263页

作者：杨建龙张浩然刘畅谷成富上海交通大学生物医学工程学院上海200240

光学相干层析成像(OCT)能够无损获得微米级空间分辨率的样品截面信息,在眼科、血管内科等临床诊疗研究和应用中起到了重要的作用。利用OCT测量光场的幅度可以获得样本的三维结构信息,如眼底视网膜的分层结构,但对组织特异性、血流、力... 详细信息

光学相干层析成像(OCT)能够无损获得微米级空间分辨率的样品截面信息,在眼科、血管内科等临床诊疗研究和应用中起到了重要的作用。利用OCT测量光场的幅度可以获得样本的三维结构信息,如眼底视网膜的分层结构,但对组织特异性、血流、力学特性等功能信息的作用有限。基于相位、偏振态、波长等光场参量的OCT功能成像技术应运而生,如多普勒OCT、OCT弹性成像、偏振敏感OCT、可见光OCT等。其中,基于光场幅度动态变化的OCT功能成像技术具有显著的鲁棒性和系统复杂度优势,已经在临床无标记血管造影中获得成功。此外,应用于三维血流流速测量的动态光散射OCT、具有无标记组织/细胞特异性显示能力的动态OCT、能够监控热物理治疗温度场的OCT温度层析成像等,已经成为了OCT功能成像的技术前沿。综述基于光场幅度动态变化的OCT功能成像技术的原理、实现和应用,分析了所面临的技术挑战,并展望了未来发展方向。

关键词：光学相干层析成像功能成像光场幅度动态变化动态光散射

A Novel Prediction Method of Optimal Driving Speed for Intelligent Vehicles in Urban Traffic Scenarios

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A Novel Prediction Method of Optimal Driving Speed for Intel...

A Real-Time Vessel-Buoy Collision Risk Estimation Model for Inland Waterway Navigation

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作者： Yeqing Zhang Mailing Wang tong liu School of Automation Beijing Institute of Technology

Due to sensitively reflect traffic conditions in road network, driving speed is a vital index to evaluate the capability of urban traffic network and intelligent transportation system. The research on optimal driving speed is beneficial for improving the stability and safety of intelligent vehicles in urban traffic scenarios. This paper puts forward a novel prediction method of optimal driving speed for urban intelligent vehicles based on road design principles and traffic flow theories. Firstly, driving factors of urban traffic scenarios are selected, quantized and stored in the optimal-driving geographic information database established for intelligent vehicles. Secondly, multivariate linear equations are investigated using regression analysis methods to reveal the relationship between driving speed of intelligent vehicles and related factors, including urban road parameters, real-time traffic conditions and vehicle information. Thirdly, urban traffic variable-length model is built to explore dynamic characteristics of traffic evolution, further macroscopic constraint equations of driving speed for intelligent vehicles are deduced based on traffic fundamental diagram. Finally, regarding instant travel time, total travel time and total travel distance as evaluation metrics, the optimal solution of the multivariate linear equation and macroscopic constraint equations is calculated ultimately, which is the optimal driving speed for intelligent vehicles in the urban traffic network. Simulation results have proved that the proposed prediction method can provide safe, feasible and efficient driving speed advice for intelligent vehicles in urban traffic scenarios.

关键词： Multivariate Linear Regression Variable Length Model Traffic Fundamental Diagram Geographic Information System Intelligent Vehicles

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A Real-Time Vessel-Buoy Collision Risk Estimation Model for ...

Safety of high-carbohydrate fluid diet 2 h versus overnight fasting before non-emergency endoscopic retrograde cholangiopancreatography:A single-blind,multicenter,randomized controlled trial

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作者： Tingxuan Li Shan Liang tong liu Key Laboratory of Dependable Service Computing in Cyber Physical Society Ministry of Education College of Automation Chongqing University

The inland waterway is the navigation passage in inland waters including rivers,lakes,reservoirs and channels,in which the buoy plays an important role in the pilotage for guiding vessels（especially in large size） to avoid dangerous water ***,the inland waterway buoys can easily be drifted or even damaged by a vessel crash,which may lead to a serious waterway traffic *** order to increase the security of buoys,the collision risk estimation is seriously required to detect potential Vessel-Buoy collision events ahead of *** by this demand,we propose a real-time Vessel-Buoy collision risk estimation model to reduce the collision *** this study the Kalman Filtering（KF） is firstly introduced to predict *** an improved KUNZI model is built to estimate collision *** experiment results show a real-time dynamic Vessel-Buoy collision risk estimation and reveal the advantages compared to a traditional estimation model.

关键词： Collision Risk Trajectory Prediction Kalman Filtering KUNZI model

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Chinese Medical Journal 2024年第12期137卷 1437-1446页

作者： Wenbo Meng Joseph W.Leung Zhenyu Wang Qiyong Li Leida Zhang Kai Zhang Xuefeng Wang Meng Wang Qi Wang Yingmei Shao Jijun Zhang Ping Yue Lei Zhang Kexiang Zhu Xiaoliang Zhu Hui Zhang Senlin Hou Kailin Cai Hao Sun Ping Xue Wei liu Haiping Wang Li Zhang Songming Ding Zhiqing Yang Ming Zhang Hao Weng QingyuanWu Bendong Chen Tiemin Jiang Yingkai Wang Lichao Zhang Ke Wu Xue Yang Zilong Wen Chun liu LongMiao Zhengfeng Wang Jiajia Li Xiaowen Yan Fangzhao Wang Lingen Zhang Mingzhen Bai Ningning Mi XianzhuoZhang Wence Zhou Jinqiu Yuan Azumi Suzuki Kiyohito Tanaka Jiankang liu Ula Nur Elisabete Weiderpass Xun Li Department of General Surgery The First Hospital of Lanzhou UniversityLanzhouGansu 730000China Key Laboratory of Biological Therapy and Regenerative Medicine Transformation Gansu Province LanzhouGansu 730000China Division of Gastroenterology and Hepatology UC Davis Medical CenterSacramentoCA 95816USA Department of Minimally Invasive Surgery Tianjin Nankai HospitalTianjin 300100China Division of Hepatobiliary and Pancreatic Surgery Department of SurgeryShulan(Hangzhou)Hospital Affiliated to Zhejiang Shuren UniversityHangzhouZhejiang 310000China Department of Hepatobiliary Surgery Southwest HospitalArmy Medical UniversityChongqing 400000China Hepatobiliary Surgery Department Shandong Provincial Third HospitalJinanShandong 250000China Department of General Surgery Xinhua HospitalAffiliated to Shanghai Jiao Tong University School of MedicineShanghai Key Laboratory of Biliary Tract Disease ResearchShanghai 200000China Department of Hepatobiliary and Pancreatic Surgery The First Hospital of Jilin UniversityChangchunJilin 130000China Department of Hepatobiliary Surgery The General Hospital of Ningxia Medical UniversityYinchuanNingxia 750000China Department of Hepatobiliary&Hydatid Digestive and Vascular Surgery CenterXinjiang Key Laboratory of Echinococcosis and Liver Surgery ResearchThe First Affiliated Hospital of Xinjiang Medical UniversityUrumqiXinjiang 830000China Department of Hepatobiliary and Pancreatic Surgery The First Hospital of Shanxi Medical UniversityTaiyuanShanxi 030000China Department of General Surgery The Second Hospital of Lanzhou UniversityLanzhouGansu 730000China Department of Biliopancreatic Endoscopic Surgery The Second Hospital of Hebei Medical UniversityShijiazhuangHebei 050000China Gastrointestinal Surgery Department Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei 430000China Department of Hepatobiliary Surgery The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’anShaanxi 710000China Depart

Background:Although overnight fasting is recommended prior to endoscopic retrograde cholangiopancreatography(ERCP),the benefits and safety of high-carbohydrate fluid diet(CFD)intake 2 h before ERCP remain *** study aimed to analyze whether high-CFD intake 2 h before ERCP can be safe and accelerate patients’***:This prospective,multicenter,randomized controlled trial involved 15 tertiary ERCP centers.A total of 1330 patients were randomized into CFD group(n=665)and fasting group(n=665).The CFD group received 400 mL of maltodextrin orally 2 h before ERCP,while the control group abstained from food/water overnight(>6 h)before *** ERCP procedures were performed using deep sedation with intravenous *** investigators were blinded but not the *** primary outcomes included postoperative fatigue and abdominal pain score,and the secondary outcomes included complications and changes in metabolic *** outcomes were analyzed according to a modified intention-to-treat ***:The post-ERCP fatigue scores were significantly lower at 4 h(4.1±2.6 vs.4.8±2.8,t=4.23,P<0.001)and 20 h(2.4±2.1 vs.3.4±2.4,t=7.94,P<0.001)in the CFD group,with least-squares mean differences of 0.48(95%confidence interval[CI]:0.26-0.71,P<0.001)and 0.76(95%CI:0.57-0.95,P<0.001),*** 4-h pain scores(2.1±1.7 vs.2.2±1.7,t=2.60,P=0.009,with a least-squares mean difference of 0.21[95%CI:0.05-0.37])and positive urine ketone levels(7.7%[39/509]vs.15.4%[82/533],χ^(2)=15.13,P<0.001)were lower in the CFD *** CFD group had significantly less cholangitis(2.1%[13/634]vs.4.0%[26/658],χ^(2)=3.99,P=0.046)but not pancreatitis(5.5%[35/634]vs.6.5%[43/658],χ^(2)=0.59,P=0.444).Subgroup analysis revealed that CFD reduced the incidence of complications in patients with native papilla(odds ratio[OR]:0.61,95%CI:0.39-0.95,P=0.028)in the multivariable ***:Ingesting 400 mL of CFD 2 h before ERCP is safe,with a reduction in post-ERCP fatigue,

关键词： Endoscopic retrograde cholangiopancreatography ERCP Carbohydrate Fasting Safety Complications Enhanced recovery after surgery Randomized controlled trial

古尔班通古特沙漠西部退化梭梭群落多样性与土壤理化性质的关系

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应用与环境生物学报 2018年第5期24卷 1165-1170页

作者：李中赫刘彤石河子大学生命科学学院

以古尔班通古特沙漠西部退化梭梭林为研究对象，野外取样调查和实验室检测分析相结合，探讨退化梭梭群落植物分布及多样性特征，并结合土壤理化性质分析引起梭梭群落退化的主要环境因素．结果显示：（1）退化梭梭群落共有6种多年生植物... 详细信息

以古尔班通古特沙漠西部退化梭梭林为研究对象，野外取样调查和实验室检测分析相结合，探讨退化梭梭群落植物分布及多样性特征，并结合土壤理化性质分析引起梭梭群落退化的主要环境因素．结果显示：（1）退化梭梭群落共有6种多年生植物，其中梭梭在各样地均有分布，其分布频度达到60％以上的样地数占总样地数的80％．盐生假木贼在60％的样地中有分布，而柽柳、白刺、淡枝沙拐枣和翼果驼蹄瓣仅在个别样地有分布且分布频度较低．（2）退化梭梭群落Shannon-Wiener指数变化幅度为0．1．25，Simpson优势度指数大于0．5的样地数占总样地数的90％，而仅有9个样地的Pielou均匀度指数大于0．5．（3）相关分析表明梭梭群落盖度与0-40cm土层中的有机质、电导率、氯离子（CI-）、土壤含水量有显著的正相关关系．（4）主成分分析发现0．40cm土层的有机质、电导率、CI-含量、土壤含水量对群落物种多样性指数均产生显著的负作用，而40—80cm土层的有机质、电导率、c1含量、土壤含水量对群落物种多样性指数均产生显著的正作用．因此认为，古尔班通古特沙漠西部优势物种梭梭退化群落植物多样性简单，随着梭梭退化，表层土壤理化性质变劣，对群落中不同物种的种子萌发、幼苗建立产生影响，影响了植物分布和多样性组成，进而导致梭梭群落物种多样性的变化．（图1表4参39）

关键词：退化梭梭群落植物分布群落盖度物种多样性土壤理化性质古尔班通古特沙漠