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Parallel Nanoimprint Forming of One-Dimensional Chiral Semiconductor for Strain-Engineered Optical Properties

Nano-Micro Letters 2020年第11期12卷 242-254页

作者： Yixiu Wang Shengyu Jin Qingxiao Wang Min Wu shukai yao Peilin Liao Moon JKim Gary JCheng Wenzhuo Wu School of Industrial Engineering Purdue UniversityWest LafayetteIN 47907USA Flex Laboratory Purdue UniversityWest LafayetteIN 47907USA Department of Materials Science and Engineering University of Texas at DallasRichardsonTX 75080USA School of Materials Engineering Purdue UniversityWest LafayetteIN 47907USA Birck Nanotechnology Center Purdue UniversityWest LafayetteIN 47907USA Regenstrief Center for Healthcare Engineering Purdue UniversityWest LafayetteIN 47907USA

The low-dimensional,highly anisotropic geometries,and superior mechanical properties of one-dimensional(1D) nanomaterials allow the exquisite strain engineering with a broad tunability inaccessible to bulk or thin-film materials.Such capability enables unprecedented possibilities for probing intriguing physics and materials science in the 1-D limit.Among the techniques for introducing controlled strains in 1D materials,nanoimprinting with embossed substrates attracts increased attention due to its capability to parallelly form nanomaterials into wrinkled structures with controlled periodicities,amplitudes,orientations at large scale with nanoscale resolutions.Here,we systematically investigated the strain-engineered anisotropic optical properties in Te nanowires through introducing a controlled strain field using a resist-free thermally assisted nanoimprinting process.The magnitude of induced strains can be tuned by adjusting the imprinting pressure,the nanowire diameter,and the patterns on the substrates.The observed Raman spectra from the chiral-chain lattice of 1D Te reveal the strong lattice vibration response under the strain.Our results suggest the potential of 1D Te as a promising candidate for flexible electronics,deformable optoelectronics,and wearable sensors.The experimental platform can also enable the exquisite mechanical control in other nanomaterials using substrate-induced,on-demand,and controlled strains.

关键词： Chiral semiconductor Nanowires Nanoimprinting Strain engineering Optical property

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Self-healing behavior of Ti_(2)AlC at a low oxygen partial pressure

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Journal of Advanced Ceramics 2022年第11期11卷 1687-1695页

作者： Boxiang yao Shibo LI Weiwei ZHANG Wenbo YU Yang ZHOU shukai FAN Guoping BEI Center of Materials Science and Engineering School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China China Porcelain Fuchi(Suzhou)High Tech Nano Materials Co. Ltd.Suzhou 215100China

Ti_(2)AlC,a MAX phase ceramic,has an attractive self-healing ability to restore performance via the oxidation-induced crack healing mechanism upon healing at high temperatures in air(high oxygen partial pressures).However,such healing ability to repair damages in vacuum or low oxygen partial pressure conditions remains unknown.Here,we report on the self-healing behavior of Ti_(2)AlC at a low oxygen partial pressure of about 1 Pa.The experimental results showed that the strength recovery depends on both healing temperature and time.After healing at 1400℃for 1–4 h,the healed samples exhibited the recovered strengths even exceeding the original strength of 375 MPa.The maximum recovered strength of~422 MPa was achieved in the healed Ti_(2)AlC sample after healing at 1400 for 4 h,about 13%higher than the original strength.Damages were healed by the formed℃TiCx from the decomposition of Ti_(2)AlC.The decomposition-induced crack healing as a new mechanism in the low oxygen partial pressure condition was disclosed for the MAX ceramics.The present study illustrates that key components made of Ti_(2)AlC can prolong their service life and keep their reliability during use at high temperatures in low oxygen partial pressures.

关键词： MAX ceramics Ti_(2)AlC self-healing low oxygen partial pressures strength recovery mechanism

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Synthesis and properties of MoAlB composites reinforced with SiC particles

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Journal of Advanced Ceramics 2022年第3期11卷 495-503页

作者： Weiwei ZHANG Shibo LI Shuang WU Boxiang yao shukai FAN Guoping BEI Wenbo YU Yang ZHOU Ying WU Sun-An DING Center of Materials Science and Engineering School of Mechanical and Electronic Control Engineering.Beijing Jiaotong UniversityBeijing 100044China Research Center of Rail Vehicles Safety Monitoring and Health Management Beijing Jiaotong UniversityBeijing 100044China China Porcelain Fuchi(Suzhou)High Tech Nano Materials Co. Ltd.Suzhou 215100China School of Microelectronics Southern University of Science and TechnologyShenzhen 518055China

Novel MoAlB composites reinforced with 5–15 vol% SiC have been firstly prepared and characterized in the present study. The SiC reinforcement is stable with MoAlB at a sintering temperature of 1200 ℃ in Ar. The 5 vol% SiC/MoAlB composite exhibited improved mechanical properties and enhanced oxidation resistance. A flexural strength of 380 MPa and a Vickers hardness of 12.7 GPa were achieved and increased by 24% and 51%, respectively, as compared with those for MoAlB, indicating the enhanced strengthening effect of SiC. Cyclic oxidation tests at 1200 and 1300 ℃ for 10 h in air showed that the 5 vol% SiC/MoAlB composite has better oxidation resistance than MoAlB due to the formation of a dense and continuous scale composed of Al_(2)O_(3) and SiO_(2), which prevents the oxygen inward diffusion and the evaporation of oxides. We expect that the general strategy of second phase reinforcing for materials will help to widen the applications of MoAlB composites.

关键词： SiC/MoAlB composite mechanical properties oxidation microstructure

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Development and validation of a nomogram to predict indolent course in patients with ulcerative colitis:a single-center retrospective study

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Gastroenterology Report 2022年第1期10卷 405-412页

作者： Na Li shukai Zhan Caiguang Liu Tong Li Tong Tu Baili Chen yao He Minhu Chen Zhirong Zeng Xiaojun Zhuang Department of Gastroenterology The First Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdongP.R.China

Background:The natural disease course for patients with ulcerative colitis(UC)is heterogeneous and few data are available on the indolent course of UC and its related factors.We aimed to develop and validate a nomogramto predict indolent course in patients with UC.Methods:Data of patients diagnosed with UC in the First Affiliated Hospital of Sun Yat-sen University(Guangzhou,China)between April 2007 and February 2021 were retrospectively analysed.Indolent course was defined as a disease course without need for strict interventions(steroids,immunomodulators,biological agents,hospitalization,or surgery therapy)during the follow-up period.The whole cohort was randomly divided into training set and validation set.The nomogram was constructed in the training set based on the results of univariate and multivariate Cox regression analyses.The performance of the nomogram was assessed by the concordance index(C-index),area under the receiver-operating characteristic curve(AUC),and calibration plots.In addition,we internally validated the nomogramvia the bootstrap method and the validation set.Results:Of 969 treatment-naive patients with UC,771(79.6%)had an indolent course after diagnosis.Of these,313 patients were included in the development and validation of the nomogram.The nomogram incorporating age,disease activity,C-reactive protein,and platelet count showed good calibration and discrimination.The C-index was 0.759(0.741 in bootstrap validation)and the AUC at 2,4,and 6 years was 0.767,0.782,and 0.775,respectively.The nomogramperformed well when applied to the validation set.Conclusion:A majority of patients with UC had an indolent course after diagnosis.The nomogram developed in this study might be useful in therapeutic decision-making and follow-up management for patients with UC.

关键词： ulcerative colitis indolent course predict nomogram

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基于偏载检测技术的实时反馈装车方法的设计与研究

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煤矿机械 2020年第2期41卷 14-16页

作者：姚树楷天地科技股份有限公司北京100013

针对目前铁路运输上常出现的车辆偏载现象,通过对车辆装车时的偏载情况进行分析,设计了偏载实时检测系统,通过快速定量装车站的装车设备联合控制,可以实现装车过程的实时反馈控制,显著改善了装车偏载现象,提高了装车系统的自动化程度。

关键词：偏载检测实时反馈控制装车站

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全自动防偏载抛撒式卸料系统的研究

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煤矿机械 2020年第3期41卷 26-28页

作者：武徽姚树楷煤炭科学研究总院储装分院北京100013 中煤科工集团天地科技股份有限公司北京100013

针对当前装车站抛撒式卸料过程中,过程控制难度大、物料极易偏载、人工介入程度高等问题,开发设计了一种全自动抗偏载的抛撒式卸料系统。通过跟踪待卸载的物料状态和列车运动的情况,实现对溜槽卸料闸板的自动连续控制。该系统在抛撒式... 详细信息

针对当前装车站抛撒式卸料过程中,过程控制难度大、物料极易偏载、人工介入程度高等问题,开发设计了一种全自动抗偏载的抛撒式卸料系统。通过跟踪待卸载的物料状态和列车运动的情况,实现对溜槽卸料闸板的自动连续控制。该系统在抛撒式卸料情况下,可将物料均匀有序填充到车厢底部,避免了偏载情况的出现和人工干预的情况,提高了装车系统的自动化程度。

关键词：装车站防偏载抛撒式卸料

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综合安全评估的研究进展及展望

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哈尔滨工程大学学报 2021年第1期42卷 152-158页

作者：张树凯刘正江蔡垚史国友梁伟珍上海海事大学商船学院上海201306 招商局集团招商蛇口邮轮事业部广东深圳518067 大连海事大学航海学院辽宁大连116026 交通运输部政策研究室北京100736

为提高海上安全和环保水平,国际海事组织采纳并倡导由英国提出的综合安全评估方法。综合安全评估现已广泛应用于国际海事组织规则制定、船舶设计制造、航运安全管理等多方面。本文通过回顾综合安全评估产生的背景及其在国际海事组织的... 详细信息

为提高海上安全和环保水平,国际海事组织采纳并倡导由英国提出的综合安全评估方法。综合安全评估现已广泛应用于国际海事组织规则制定、船舶设计制造、航运安全管理等多方面。本文通过回顾综合安全评估产生的背景及其在国际海事组织的发展历程、对比新旧综合安全评估指南,归纳了综合安全评估的最新进展。最后,分析了综合安全评估的未来发展趋势以及综合安全评估研究中存在的不足和亟待开展的工作。建议我国加强海事风险数据的统一管理并建立分享机制,为我国综合安全评估相关的国际海事组织提案提供技术和案例支持,在国际海事公约、规则、规范的制定过程中为我国争取更多的话语权。

关键词：综合安全评估海上安全风险分析海事基础数据库专家意见一致度评判 ALARP原则 GBS原则安全水平法

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基于Douglas-Peucker算法的船舶AIS航迹数据压缩

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哈尔滨工程大学学报 2015年第5期36卷 595-599页

作者：张树凯刘正江张显库史国友蔡垚大连海事大学航海学院辽宁大连116026

为解决普通模式下,将海量AIS航迹数据显示在ECDIS平台上效率低、实时性差等问题,设计一种基于DouglasPeucker算法的AIS航迹数据压缩算法。通过分析AIS航迹数据的特征,总结普通模式下ECDIS平台AIS航迹显示实时性差的原因,提出在保留原始... 详细信息

为解决普通模式下,将海量AIS航迹数据显示在ECDIS平台上效率低、实时性差等问题,设计一种基于DouglasPeucker算法的AIS航迹数据压缩算法。通过分析AIS航迹数据的特征,总结普通模式下ECDIS平台AIS航迹显示实时性差的原因,提出在保留原始航迹特征和误差允许的范围内剔除冗余和重复信息的思想,结合Douglas-Peucker算法,根据设定的不同阈值提取出关键特征点从而对AIS航迹数据进行压缩。在VC2010平台下对该算法进行实现,实践证明,该算法能在较低失真度的前提下对船舶AIS航迹数据进行压缩,提高了轨迹回放、再现效率,与普通模式下ECDIS显示大量AIS航迹相比,系统占用资源少、处理效率高并具有较高的稳定性。

关键词：船舶 AIS航迹 Douglas-Peucker算法数据压缩

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AIS Trajectories Simplification Based on Douglas-Peucker Algorithm

AIS Trajectories Simplification Based on Douglas-Peucker Alg...

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作者： ZHANG shukai LIU Zhengjiang CAI yao WU Zhaolin Dalian Maritime University

Automatic Identification System（AIS） trajectories are sequences of ship locations,each is associated with a timestamp,course,speed and other information describing ship’s movement.It creates problem of transmitting,storing and processing these date when recorded trajectories are becoming larger.Therefore,using adequate method as an accurate representation with least distortion is necessary,and it should be obtained by compression of redundant information while maintaining the characteristic points.The main object of this paper is to study the AIS trajectories simplification by using the original Douglas-Peucker algorithm and the improved Douglas-Peucker algorithm.Furthermore,by comparing the efficiency and effectiveness of the two algorithms while simplifying 11 days AIS trajectories of Qiongzhou Strait,the optimal algorithm is obtained.Finally,through the analysis of function curvature between simplification thresholds with compression rate,the maximum curvature is confirmed and acted as optimal simplification threshold.

关键词： line simplification AIS trajectories Douglas-Peucker threshold

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顶空固相微萃取-气相色谱/质谱法测定水中丁基黄原酸

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分析试验室 2021年第6期40卷 727-730页

作者：张泾凯顾雪华鄢姝恺顾雅婷姚斌顾颖苏州见远检测技术有限公司苏州215000

在酸性条件下,水中的丁基黄原酸能快速水解生成二硫化碳(CS_(2)),通过固相微萃取吸附,并与气相色谱-质谱仪联用,建立了测定水中丁基黄原酸的新方法。CS_(2)质量浓度在0.10~10.0μg/L范围内呈良好的线性,检出限为20 ng/L,定量限为80 ng/L... 详细信息

在酸性条件下,水中的丁基黄原酸能快速水解生成二硫化碳(CS_(2)),通过固相微萃取吸附,并与气相色谱-质谱仪联用,建立了测定水中丁基黄原酸的新方法。CS_(2)质量浓度在0.10~10.0μg/L范围内呈良好的线性,检出限为20 ng/L,定量限为80 ng/L,纯水加标的平均回收率为95.0%~98.8%,相对标准偏差为3.9%~6.8%;对饮用水和地表水进行了加标回收率实验,其平均回收率范围在94.3%~99.4%之间,相对偏差为2.0%~4.5%。方法已用于实际水样的测定。

关键词：丁基黄原酸固相微萃取气相色谱-质谱

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