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Solvability and thermal response of cellulose with different crystal configurations

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Frontiers of Engineering Management 2019年第1期6卷 62-69页

作者： qian CHEN Kai ZHENG Qingtao FAN Kun WANG Haiyan YANG Jianxin JIANG shijie LIU Beijing Key Laboratory of Lignocellulosic Chemistry College of Materials Science and Technology Beijing Forestry University Beijing 100083 China Beijing Institute of Science and Technology Information Beijing 100044 China College of Chemical Engineering Southwest Forestry University Kunming 650224 China Department of Paper and Bioprocess Engineering SUNY College of Environmental Science and Forestry 1 Forestry Drive Syracuse NY 13210 USA

Cellulose is a biodegradable and renewable natural material that it is naturally resistant to breaking and modification. Moreover, the crystalline structure of cellulose is a major factor restricting its industrial utilization. In this study, cellulose polymorphs were prepared from natural cellulose, and their solvability and thermal response were investigated. Using liquid- and solid-state NMR signals, the distinct types and dissolving states of cellulose polymorphs were identified. The thermal behavior of the polymorphic forms of cellulose-d was also evaluated, and cellulose Ⅱ exhibited the poorest thermal stability and a unique exothermic reaction.

关键词： cellulose crystal structure thermal response XRD CP/MAS^13C NMR

Method of Smartphone Navigation Heading Compensation Based on Gravimeter

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Method of Smartphone Navigation Heading Compensation Based o...

Selective laser melting of NiTi alloy with superior tensile property and shape memory effect

第九届中国卫星导航学术年会

作者： shijie Zeng Qinghua Zeng qian Meng Jianye Liu Ruizhi Chen Navigation Research Center Nanjing University of Aeronautics and Astronautics State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan University

Smartphone based pedestrian inertial navigation system usually uses the Pedestrian Dead Reckoning(PDR) algorithm to achieve navigation and *** traditional PDR algorithm requires inertial devices to remain a stationary position relative to the human body,however,in the field of smart pedestrian navigation,smartphone can’t always keep a stationary posture when it is being *** the way of using smartphone has been changed,traditional PDR algorithm will give the wrong heading estimation which is caused by the change of smartphone’s ***,in order to satisfy the navigation demand for smartphone pedestrian inertial positioning especially when the using way changed,a Heading Compensation with Gravity Assisted(HCGA) method is proposed in this *** method will judge the change of smartphone’s attitude and compensate heading based on data from gravity *** result of experiment shows that using HCGA method,it can be distinguished whether the change of heading caused by the attitude change automatically when the change of heading is detected,then compensate the result of *** this way,the influence of navigation solution caused by different handheld modes will be reduced.

关键词： Gravity Assisted Smartphone Navigation Heading Compensation

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Journal of Materials Science & Technology 2019年第10期35卷 2238-2242页

作者： Zhiwei Xiong Zhonghan Li Zhen Sun shijie Hao Ying Yang Meng Li Changhui Song Ping Qiu Lishan Cui State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China qian Xuesen Laboratory of Space Technology China Academy of Space TechnologyBeijing100094China School of Mechanical&Automotive Engineering South China University of TechnologyGuangzhou510641China

It is a challenge to develop complex-shaped Ni Ti shape memory alloy parts by traditional processing methods, due to the poor machinability of Ni Ti alloy. It is reported that selective laser melting(SLM) of additive manufacturing could overcome this problem. However, the reported SLM-produced Ni Ti exhibits poor tensile ductility due to the inner defects and adverse unidirectional columnar grains from SLM process. In this work, the defect-less SLM-Ni Ti with nondirective columnar grains was fabricated by optimizing the intraformational laser scanning length and interformational laser scanning direction. The obtained lath-shaped SLM-Ni Ti sample exhibits tensile strain of 15.6%, more than twice of the reported maximum result(7%). Besides, the SLM-Ni Ti part with complex geometry displays a shape memory recovery of 99% under compressive deformation of 50%.

关键词： NiTi shape memory alloy Selective laser melting Tensile ductility Shape memory effect

Grain-size gradient NiTi ribbons with multiple-step shape transition prepared by melt-spinning

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Journal of Materials Science & Technology 2021年第12期71卷 163-168页

作者： Xiangguang Kong Ying Yang Shiyu Guo Ran Li Bo Feng Daqiang Jiang Meng Li Changfeng Chen Lishan Cui shijie Hao State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China Beijing Key Laboratory of Failure Corrosionand Protection of Oil/Gas FacilitiesChina University of Petroleum BeijingBeijing102249China Key Laboratory of Aerospace Materials and Performance School of Materials Science and EngineeringBeihang UniversityBeijing100191China qian Xuesen Laboratory of Space Technology China Academy of Space TechnologyYouyi Street No.104HaidianBeijing100094China

A grain-size gradient Ni Ti ribbon with multiple-step shape transition was papered by means of *** ribbons contain coarse and fine grains in the free surface side and copper roller surface side,*** grain-size gradient microstructure induces a two-stage phase transformation behavior in the ribbons during heating or *** tensile deformation pre-treatment,the ribbons exhibit a back-and-forth shape change(shape A→B→A)upon a single heating or cooling process,resulting from the sequential phase transformation through the thickness of the ribbon as dictated by gradient grain *** activating performance of the ribbons,*** transition amplitude and speed,can be customized by controlling the pre-deformation *** work offers a new opportunity for innovative designs to reach a novel shape memory behavior in Ni Ti alloys conveniently and efficiently.

关键词： NiTi shape memory alloy Melt spinning Shape memory effect Martensitic transformation

基于小波域平稳子空间分析的风力发电机齿轮箱故障诊断

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机械工程学报 2014年第11期50卷 9-16页

作者：严如强钱宇宁胡世杰高晓旸东南大学仪器科学与工程学院南京210096 康涅狄格大学机械工程系

风力发电机齿轮箱故障信号为非平稳瞬态微弱信号,容易被齿轮啮合信号及其他噪声淹没。提出一种融合连续小波变换(Continuous wavdot transform,CWT)和平稳子空间分析(Startionary subspace analysis,SSA)的信号分解方法并应用于风力发... 详细信息

风力发电机齿轮箱故障信号为非平稳瞬态微弱信号,容易被齿轮啮合信号及其他噪声淹没。提出一种融合连续小波变换(Continuous wavdot transform,CWT)和平稳子空间分析(Startionary subspace analysis,SSA)的信号分解方法并应用于风力发电机齿轮箱故障诊断中。平稳子空间分析作为一种盲源分离技术可将高维数据分解成平稳源部分和非平稳源部分,对待分析信号各分量间的独立性没有要求且不需要任何先验信息。连续小波变换则可利用其所具有的多尺度分析特性把一维时间序列转换为不同尺度下的多维时间序列。对观测得到的一维时间序列数据进行连续小波变换得到多维时间序列作为平稳子空间分析的输入,利用平稳子空间分析方法将该多维时间序列分解为平稳源信号分量和非平稳源信号分量,对非平稳源信号进行包络谱分析得到齿轮箱故障的特征频率。该小波域平稳子空间分析方法被应用于一个实际风力发电机齿轮箱振动信号的分析,试验结果表明该方法可有效地诊断出齿轮箱中的轴承故障。

关键词：风力发电机齿轮箱故障诊断连续小波变换平稳子空间分析

Fringe pattern analysis using deep learning

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Advanced Photonics 2019年第2期1卷 34-40页

作者： shijie Feng qian Chen Guohua Gu Tianyang Tao Liang Zhang Yan Hu Wei Yin Chao Zuo Nanjing University of Science and Technology School of Electronic and Optical EngineeringNanjingChina Jiangsu Key Laboratory of Spectral Imaging and Intelligent Sense NanjingChina Nanjing University of Science and Technology Smart Computational Imaging Laboratory(SCILab)NanjingChina

In many optical metrology techniques,fringe pattern analysis is the central algorithm for recovering the underlying phase distribution from the recorded fringe *** extensive research efforts for decades,how to extract the desired phase information,with the highest possible accuracy,from the minimum number of fringe patterns remains one of the most challenging open *** by recent successes of deep learning techniques for computer vision and other applications,we demonstrate for the first time,to our knowledge,that the deep neural networks can be trained to perform fringe analysis,which substantially enhances the accuracy of phase demodulation from a single fringe *** effectiveness of the proposed method is experimentally verified using carrier fringe patterns under the scenario of fringe projection *** results demonstrate its superior performance,in terms of high accuracy and edge-preserving,over two representative single-frame techniques:Fourier transform profilometry and windowed Fourier transform profilometry.

关键词： fringe analysis phase measurement deep learning

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规模化储能参与电力现货市场的商业模式

上海交通大学学报 2023年第12期57卷 1543-1558页

作者：李迁姜欣张钧钊段世杰金阳郑州大学电气工程学院郑州450001

以规模化储能为研究对象,在电力市场放开背景下,开展其参与电力现货市场的商业模式研究.首先,从国内外典型市场出清机制出发,分析日前市场及实时市场的出清方式、出清计算等过程,提出适应规模化储能参与现货市场的联合出清机制,包括投... 详细信息

以规模化储能为研究对象,在电力市场放开背景下,开展其参与电力现货市场的商业模式研究.首先,从国内外典型市场出清机制出发,分析日前市场及实时市场的出清方式、出清计算等过程,提出适应规模化储能参与现货市场的联合出清机制,包括投标方式、计费方式和出清方式等.其次,为充分发掘规模化储能的市场价值与其他附加价值,增强集群效应并解决储能容量闲置问题,提出适应规模化储能参与现货市场的商业模式,包括独立式(投资主体单一、服务模式单一),联盟式(投资主体多样、服务模式单一),共享式(投资主体多样、服务模式多样),并分析市场交易链中存在的博弈关系,量化电能价值、辅助服务价值以及其他附加价值.在此基础上,基于主从博弈构建不同商业模式下储能参与现货联合市场的双层出清模型范式.上层模型以储能为领导者、以储能收益最大化为目标参与市场竞争,下层模型以调度和交易中心为跟随者、以社会福利最大化为目标进行联合出清;最后,基于改进的IEEE30节点系统,以典型交易场景为例验证所提参与商业模式的有效性和可行性.

关键词：规模化储能现货市场出清机制商业模式博弈论

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基于深度学习的散斑投影轮廓术

红外与激光工程 2020年第6期49卷 73-83页

作者：钟锦鑫尹维冯世杰陈钱左超(指导) 南京理工大学电子工程与光电技术学院智能计算成像实验室(SCILab)江苏南京210094 南京理工大学江苏省光谱成像与智能感知重点实验室江苏南京210094

针对传统的单幅散斑图像匹配算法测量精度低且无法测量复杂面型物体等问题,提出了一种基于深度学习的散斑投影轮廓术,即通过深度学习的方法实现散斑图像的逐像素匹配。设计利用孪生卷积神经网络结构,将目标散斑图像和参考散斑图像以图... 详细信息

针对传统的单幅散斑图像匹配算法测量精度低且无法测量复杂面型物体等问题,提出了一种基于深度学习的散斑投影轮廓术,即通过深度学习的方法实现散斑图像的逐像素匹配。设计利用孪生卷积神经网络结构,将目标散斑图像和参考散斑图像以图像块的形式输入神经网络。通过卷积层运算提取散斑图像块的特征信息,进而将子网络得到的特征信息融合为两个图像块之间的匹配系数,以获得散斑图像的视差数据,并最终可将视差数据转化为物体的三维信息。实验结果表明,该方法可以通过单幅散斑图像实现精度约为290μm的三维轮廓测量。

关键词：散斑投影深度学习三维测量孪生网络

Effect of Hot Extrusion and Cyclic Extrusion Compression Progress on the Microstructures and Properties of Mg-Zn-Y-Nd Alloy

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Effect of Hot Extrusion and Cyclic Extrusion Compression Pro...