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Study on attrition of spherical-shaped Mo/HZSM-5 catalyst for methane dehydro-aromatization in a gas–solid fluidized bed

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Chinese Journal of Chemical Engineering 2021年第10期34卷 172-183页

作者： Xinzhuang Zhang yunda han Dapeng Li Zhanguo Zhang Xiaoxun Ma School of Chemical Engineering Northwest UniversityXi’an 710069China Research Institute of Shaanxi Yanchang Petroleum(Group)Co. Ltd.Xi’an 710065China Chemical Engineering Research Center of the Ministry of Education(MOE)for Advanced Use Technology of Shanbei Energy Xi’an 710069China Shaanxi Research Center of Engineering Technology for Clean Coal Conversion Xi’an 710069China Collaborative Innovation Center for Development of Energy and Chemical Industry in Northern Shaanxi Xi’an 710069China International Scientific and Technological Cooperation Base of the Ministry of Science and Technology(MOST)for Clean Utilization of Hydrocarbon Resources Xi’an 710069China Hydrocarbon High-efficiency Utilization Technology Research Center of Shaanxi Yanchang Petroleum(Group)Co. Ltd.Xi’an 710065China Key Laboratory on Resources Chemicals and Materials Shenyang University of Chemical TechnologyShenyang 110142China Longdong University Qingyang 745000China

As a potential methane efficient conversion process,non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance,especially in the states of high temperature,longtime rapid movement and chemical *** evaluation methods for attrition resistance,such as ASTM D5757 and Jet Cup test,are targeted for fresh catalysts at ambient temperature,which cannot well reflect the real *** this study,spherical-shaped Mo/HZSM-5 catalyst prepared by dipping and spray drying was placed in a self-made apparatus for attrition testing,in which the catalyst attrition under different system temperatures,running time and process factors was investigated with percent mass loss(PML),particle size-mass distribution(PSMD)and scanning electron microscope(SEM).Carbon deposition on the catalyst before and after activation,aromatization and regeneration was analyzed by thermogravimetry(TG),and the attrited catalysts were evaluated for methane dehydro-aromatization(MDA).The results show that the surface abrasion and body breakage of catalyst particles occur continuously,with the increase of system temperature and running time,and make the PML rise *** process factors of activation,aromatization and regeneration can cause the catalyst attrition and carbon deposits,which broaden the PSMD in varying degrees,and the carbon-substances on catalysts greatly improve their attrition resistance at high *** attrition has a certain influence on its catalytic performance,and the main reasons point to particle breakage and fine powder escape.

关键词： Attrition Mo/HZSM-5 Fluidized-bed Catalyst activation Methane dehydro-aromatization

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基于视觉感知的V2V毫米波波束对准技术

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移动通信 2023年第12期47卷 9-14页

作者：韩昀达陈舒怡叶亮哈尔滨工业大学电子与信息工程学院黑龙江哈尔滨150000

针对V2V毫米波通信中传统波束搜索方法开销较大、实时性差的问题,结合视觉感知技术,提出采用一种基于视觉感知的V2V毫米波波束对准方法,以降低波束对准的时延和开销。该方法首先利用车载单目相机采集的实时场景图像,通过FCOS3D目标检测... 详细信息

针对V2V毫米波通信中传统波束搜索方法开销较大、实时性差的问题,结合视觉感知技术,提出采用一种基于视觉感知的V2V毫米波波束对准方法,以降低波束对准的时延和开销。该方法首先利用车载单目相机采集的实时场景图像,通过FCOS3D目标检测算法,估计场景中车辆目标的三维位置;而后,对车辆目标位置进行坐标变换获得空间角度和距本车体的距离,并由此推导出模拟波束成形矢量,实现波束对准。仿真结果表明,该方法能够通过高精度的目标位置估计,在较低硬件开销的情况下,完成相对精确的波束对准。

关键词： V2V通信毫米波波束对准视觉感知

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三维微流控芯片的挤出式3D打印工艺

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微纳电子技术 2024年第9期61卷 125-132页

作者：韩蕴达苑泽伟郭凯郑雄飞王赫然沈阳工业大学机械工程学院沈阳110870 中国科学院沈阳自动化研究所机器人学国家重点实验室沈阳110016 中国科学院机器人与智能制造创新研究院沈阳110169

微流控芯片技术在疾病模型、药物筛选和个性化医疗领域显示出巨大的应用潜力。针对传统二维微流控芯片在模拟复杂生物环境方面存在局限性的问题,开发了一种新型的适用于挤出式3D打印的高分子共混材料,该混合材料由聚L-丙交酯-己内酯(PL... 详细信息

微流控芯片技术在疾病模型、药物筛选和个性化医疗领域显示出巨大的应用潜力。针对传统二维微流控芯片在模拟复杂生物环境方面存在局限性的问题,开发了一种新型的适用于挤出式3D打印的高分子共混材料,该混合材料由聚L-丙交酯-己内酯(PLCL)和聚乙二醇(PEG)组成。测试了PLCL和PEG质量比分别为7∶3、6∶4、5∶5的三种混合材料的流变性能,筛选最佳配比材料,优化打印工艺参数,实现了复杂三维结构的高精度打印,并且打印件具备明显的抗塌陷能力和飞线断丝的可控性。提出了一种创新的微流控芯片分区设计与打印方法,将芯片结构分为4个区域并单独优化打印轨迹,有效减少了悬空结构产生的塌陷。实验结果显示,PLCL和PEG质量比为7∶3的混合材料具有良好的可打印性能,在3 mm/s的打印速度、20 mm/s的飞线速度下,成功实现了无需溶芯材料的三维微流控芯片的打印,微通道截面显示了良好的形状。细胞实验显示,PLCL/PEG材料支架对人脐静脉内皮细胞(HUVEC)具有良好的细胞相容性,并且具有调节巨噬细胞极化、促进M2型表型形成的能力,显示了其在抗炎和免疫调节方面的功能。研究结果为微流控芯片的制造提供了新的材料和制备技术,拓展了3D打印在生物医学领域的应用范围,并为未来器官芯片技术的临床转化提供了实验基础。

关键词：微流控芯片挤出式3D打印高分子共混材料细胞相容性免疫调节

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Spatio-temporal Pattern and Driving Forces of Comprehensive Agricultural Productivity in Jilin Province,China

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Chinese Geographical Science 2020年第3期30卷 493-504页

作者： LIU yunda TONG Lianjun Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102China University of Chi-nese Academy of Sciences Beijing 100049China

Improving comprehensive agricultural productivity is an important measure to realize agricultural *** on the data from Jilin Statistical Yearbook,this study analyzed the spatial and temporal characteristics of comprehensive agricultural productivity discrepancy in the main agricultural production areas of Jilin Province,*** comprehensive agricultural productivity of 25 county-level administrative units were evaluated by a comprehensive index system based on five aspects which included 20 indicators from 2004 to *** pattern of the discrepancy was analyzed by the spatial differentiation indices and spatial convergence *** results were as follows:1) the overall comprehensive agricultural productivity was in a ’W-type’ rising trend;2) the discrepancy was in’inverted W-type’ trend;3) the spatial distribution characteristics were mainly discrete plaque and ’inverted V-type’;4) the formation of differences was forced by a combination of internal and external driving *** study demonstrates the effectiveness of rising agricultural productivity and the level of economic and social developments in different counties in Jilin Province.

关键词： spatio-temporal pattern comprehensive agricultural productivity spatial convergence/divergence driving forces Jilin Province,China

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求解高光谱解混的三算子分裂方法

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郑州大学学报(理学版) 2025年第2期57卷 85-88页

作者：董云达张园园李一怡郑州大学数学与统计学院

对于高光谱解混问题，提出了一个相应的三算子单调包含和求解该问题的一个分裂方法，其中邻近因子可以自适应选取。该方法还可用于求解更一般的带有线性复合的三算子单调包含问题。数值实验表明，该算法的性能远远超过最近提出的邻近内... 详细信息

对于高光谱解混问题，提出了一个相应的三算子单调包含和求解该问题的一个分裂方法，其中邻近因子可以自适应选取。该方法还可用于求解更一般的带有线性复合的三算子单调包含问题。数值实验表明，该算法的性能远远超过最近提出的邻近内点方法，并且与其变尺度版本相当。

关键词：邻近内点法单调包含分裂方法高光谱解混自适应

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Optimization of parameters on photocatalytic degradation of chloramphenicol using TiO_2 as photocatalyist by response surface methodology

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Journal of Environmental Sciences 2010年第8期22卷 1281-1289页

作者： Junwei Zhang Dafang Fu yunda Xu Cuiyun Liu Department of Municipal Engineering Southeast University Nanjing 210096 China Nanjing Engineering Research Centre for Water Treatment and Ecological Restoration Nanjing 210013 China

The experimental design methodology was applied for modeling and optimizing the operation parameters on photocatalytic degradation of chloramphenicol （CAP） using TiO 2 as photocatalyst in a photoreactor. Three experimental parameters （including pH, TiO 2 concentration and CAP initial concentration） were adopted to obtain the preliminary information. The multivariate experimental design was employed to establish a quadratic model as a functional relationship between the degradation rate of CAP and three experimental parameters. The interaction effects and optimal parameters were obtained by using Design Expert software. The optimal values of the operation parameters under the related constraint conditions were found at pH 6.4, TiO 2 concentration of 0.94 g/L and CAP initial concentration of 19.97 mg/L, respectively. The degradation rate of CAP approached 85.97% under optimal conditions. The regression analysis with R 2 value of 0.9519 had a good agreement between the experimental results and the predictive values. In addition, pH and TiO 2 concentration had a significant influence on the degradation rate of CAP.

关键词： chloramphenicol photocatalysis TiO 2 response surface methodology

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Effect of blank quenching on shear spinning forming precision of 2219 aluminum alloy complex thin-walled components

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Chinese Journal of Aeronautics 2023年第4期36卷 538-555页

作者： Zhixin LI Mei Zhan Xiaoguang FAN yunda DONG Luopeng XU School of Science Civil Aviation Flight University of ChinaGuanghan 618307China State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of High-Performance Precision Forming

The quenching-spinning(Q-S)process,i.e.,shear spinning after blank quenching,has been increasingly utilized to form 2219 aluminum alloy complex thin-walled ***,the changes in material property,shape and stress of the blanks after quenching will affect the spin-ning forming *** this study,the rules and mechanisms of these effects are investigated based on a combined finite element(FE)model including blank quenching and component spinning *** results indicate that the increase of material strength and the existence of distortion of the quenched blank lead to a notable increase in the non-uniformity of the circumferential compres-sive stress in the spinning area and the increase of the flange swing height during *** changes result in an increase in the wall thickness and component-mandrel gap of the *** quenching residual stress has little effect on wall thickness and roundness but can noticeably reduce the component-mandrel *** is because that the existence of quenching residual stress of the blank can lead to the decrease of the maximum circumferential compressive stress of the workpiece in spinning and an obvious drop in the maximum compressive stress after reaching the stress *** distortion is the main factor affecting the ***,the opti-mized installation way of the blank for spinning is obtained.

关键词： 2219 aluminum alloy Complex thin-walled com-ponents Finite element analysis Quenching distortion Residual stress Shear spinning

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Wind disturbance compensated path-following control for fixed-wing UAVs in arbitrarily strong winds

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Chinese Journal of Aeronautics 2024年第2期37卷 431-445页

作者： Hao LU Lan GAO yunda YAN Mingzhe HOU Chenliang WANG hangzhou Innovation Institute Beihang UniversityHangzhou 310051China School of Information Science and Technology Hangzhou Normal UniversityHangzhou 311121China Department of Computer Science University College LondonLondon WC1E 6BTUnited Kingdom Center for Control Theory and Guidance Technology Harbin Institute of TechnologyHarbin 150001China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Wind is the primary challenge for low-speed fixed-wing unmanned aerial vehicles to follow a predefined flight *** cope with various wind conditions,this paper proposes a wind disturbance compensated path following control strategy where the wind disturbance estimate is incorporated with the nominal guiding vector field to provide the desired airspeed direction for the *** the control input vector for the outer-loop kinematic subsystem needs to satisfy a magnitude constraint,a scaling mechanism is introduced to tune the proportions of the compensation and nominal ***,an optimization problem is formulated to pursue a maximum wind compensation in strong winds,which can be solved analytically to yield two scaling factors.A cascaded inner-loop tracking controller is also designed to fulfill the outer-loop wind disturbance compensated guiding vector ***-fidelity simulation results under sensor noises and realistic winds demonstrate that the proposed path following algorithm is less sensitive to sensor noises,achieves promising accuracy in normal winds,and mitigates the deviation from a desired path in wild winds.

关键词： Path following Guiding vector field Wind disturbance Disturbance rejection Fixed wings

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Development of microstructural inhomogeneity in multi-pass flow forming of TA15 alloy cylindrical parts

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Chinese Journal of Aeronautics 2020年第7期33卷 2088-2097页

作者： Xianxian WANG Pengfei GAO Mei Zhan Ke YANG yunda DONG Yukun LI State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of High-Performance Precision Forming Technology and EquipmentSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710072China

Revealing the development of microstructural inhomogeneity in the multi-pass flow forming of titanium alloy components is of great significance to the microstructure control and property *** this end,the microstructural inhomogeneity of TA15 alloy spun cylindrical parts was analyzed based on the deformation *** results indicate that the material underwent significant compressive strain in the normal direction(ND),tension strain in the rolling and circumferential directions(RD and CD),while tension strain in the CD is slightly small due to the limited material flow in this *** strain characteristics make the microstructure,especially the primary a(ap),present different morphologies in the different planes of the ***,the combined effects of inhomogeneous deformation and temperature distribution in the ND also cause the inhomogeneity of microstructure morphology and parameters in this *** analyses show that with the forming pass increasing,the aspect ratio of apincreases most in the normal-rolling plane,then in the normal-circumferential plane and least in the circumferential-rolling plane,whereas apcontent decreases in an opposite *** the ND,the aspect ratio and content of apis relatively high in the outer and inner surface areas but lowest in the central area,and these inhomogeneous characteristics can be gradually diminished with the forming pass ***,the variation of hardness inhomogeneity factor indicates that a four-pass forming with the total reduction ratio of 63%could obtain a homogenous microstructure along the ND of the TA15 alloy spun cylindrical part.

关键词： Deformation history Microstructural inhomogeneity Multi-pass flow forming TA15 alloy cylindrical parts Vickers hardness

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MiR-33a suppresses breast cancer cell proliferation and metastasis by targeting ADAM9 and ROS1

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Protein & Cell 2015年第12期6卷 881-889页

作者： Chuankai Zhang yunda Zhang Weiji Ding Yancheng Lin Zhengjie Huang Qi Luo Department of Gastrointestinal Surgery First Affiliated Hospital of Xiamen University Xiamen 361003 China State Key Laboratory of Cellular Stress Biology Innovation Center for Cell Signaling Network School of Life Sciences Xiamen University Xiamen 361102 China Department of Gastrointestinal Surgery First Clinical Medical College of Fujian Medical University Fuzhou 350005 China

MicroRNAs （miRNAs） are small noncoding RNAs that have a pivotal role in the post-transcriptional regulation of gene expression by sequence-specifically targeting multiple mRNAs. Although miR-33a was recently repotted to play an important role in lipid homeostasis, atherosclerosis, and hepatic fibrosis, the functions of miR-33a in tumor progression and metastasis are lar- gely unknown. Here, we found that downregulated miR- 33a in breast cancer tissues correlates with lymph node metastasis. MiR-33a expression is significantly lower in the highly metastatic breast cancer cell lines than the noncancerous breast epithelial cells and non-metastatic breast cancer cells. Moreover, the overexpression of miR-33a in metastatic breast cancer cells remarkably decreases cell proliferation and invasion in vitro and significantly inhibits tumor growth and lung metastasis in vivo, whereas its knockdown in non-metastatic breast cancer cells significantly enhances cell proliferation and invasion in vitro and promotes tumor growth and lung metastasis in vivo. Combining bioinformatics prediction and biochemical analyses, we showed that ADAM9 and ROS1 are direct downstream targets of miR-33a. These findings identified miR-33a as a negative regulator of breast cancer cell proliferation and metastasis.

关键词： miR-33a breast cancer proliferation,metastasis

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