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Comparative crystal structure determination of griseofulvin:Powder X-ray diffraction versus single-crystal X-ray diffraction

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Chinese Science Bulletin 2012年第23期57卷 3867-3871页

作者： PAN QingQing guo Ping DUAN jiong CHENG Qiang LI Hui College of Chemical Engineering Sichuan UniversityChengdu 610065China

In an attempt to compare crystal structure determination from powder data and single-crystal data,crystal structure of griseofulvin(C 17 H 17 ClO 6) was tested by both powder and single-crystal X-ray *** parameters of griseofulvin are α=90.0°,a=b=8.9757,c=19.9345,V=1605.99 3 from powder data coinciding with α=90.0°,a=b=8.9714,c=19.8848,V=1600.46 3 from single-crystal *** processes of structure elucidating of griseofulvin by the two approaches were *** X-ray diffraction was demonstrated to be a powerful auxiliary implement to single-crystal X-ray diffraction in structure characterization,and its application can be popularized in the field of structure research of small organic molecules.

关键词：单晶X-射线衍射晶体结构灰黄霉素粉末测定晶胞参数辅助工具结构特征

Recent Development in the Space Utility System of China's Manned Space Flight Program

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空间科学学报 2010年第5期30卷 388-391页

作者： Gu Yidong guo jiong General Establishment of Space Science and Application Chinese Academy of Sciences Beijing 100190

This paper briefly introduces the history of China's Manned Space Flight Program and concludes the experiments done since 2008,namely,a small satellite and a material science *** outlook of future Chinese Space Statio... 详细信息

关键词：载人航天计划空间站飞行方案中国科学实验小型卫星

Effect of cyclic wetting-drying on tensile mechanical behavior and microstructure of clay-bearing sandstone

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International Journal of Coal Science & Technology 2021年第5期8卷 956-968页

作者： Pingye guo Juan Gu Yi Su jiong Wang Zhanwen Ding State Key Laboratory for Geo-Mechanics and Deep Underground Engineering Beijing 100083China School of Mechanics Architecture and Civil EngineeringChina University of Mining and TechnologyBeijing 100083China Tang Steel International Engineering Technology Corp Tangshan 063000China China Henan Geological and Mineral Resources Construction Engineering(Group)Co. LtdZhengzhou 450007China

The understanding of the weakening mechanism of tensile strength of rock subjected to cyclic wetting-drying is critical for rock *** strength tests were conducted on a total of 35 sandstone specimens with different wetting-drying *** crack propagation process and acoustic emission characteristics of the tested samples were obtained through a high-speed camera and acoustic emission *** results indicate that the tensile strength is observably reduced after cyclic wetting-drying,and the extent of the reduction is not only related to the number of wettingdrying cycle,but also closely related to the clay mineral content of the *** addition,as the cycles of wetting-drying increase,the effect of each single cycle on tensile strength get reduced until it becomes ***,the crack initiation and penetration time is prolonged as the number of wetting-drying cycle increases,which indicates that cyclic wetting-drying weakens the rock stiffness and enhances the ductility of ***,the acoustic emission characteristics of the tested samples further confirmed the ductile behaviour of the sandstone samples with increasing wetting-drying ***,through the analysis of the microstructure and mineral composition of the samples with different wetting-drying cycles,it is concluded that the main weakening mechanisms of sandstones containing clay minerals are frictional reduction,chemical and corrosive deterioration.

关键词： Sandstone Wetting-drying cycle Tensile strength Weakening mechanism Failure characteristics

Directed graph-based distribution network reconfiguration for operation mode adjustment and service restoration considering distributed generation

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Journal of Modern Power Systems and Clean Energy 2017年第1期5卷 142-149页

作者： Haifeng HONG Zhesheng HU Ruipeng guo Jun MA jiong TIAN College of Electrical Engineering Zhejiang UniversityHangzhou 310027China Ningxia Electric Power Company State Grid Corporation of ChinaYinchuan 750001China

We present a directed graph-based method for distribution network reconfiguration considering distributed generation. Two reconfiguration situations are considered: operation mode adjustment with the objective of minimizing active power loss(situation Ⅰ) and service restoration with the objective of maximizing loads restored(situation Ⅱ). These two situations are modeled as a mixed integer quadratic programming problem and a mixed integer linear programming problem, respectively. The properties of the distribution network with distributed generation considered are reflected as the structure model and the constraints described by directed graph. More specifically, the concepts of "in-degree" and "out-degree"are presented to ensure the radial structure of the distribution network, and the concepts of "virtual node" and"virtual demand" are developed to ensure the connectivity of charged nodes in every independent power supply *** validity and effectiveness of the proposed method are verified by test results of an IEEE 33-bus system and a 5-feeder system.

关键词： Distribution network Distributed generation Network reconfiguration Directed graph Operation mode adjustment Service restoration

SERCA regulates collective cell migration by maintaining cytoplasmic Ca2+ homeostasis

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Journal of Genetics and Genomics 2019年第9期46卷 451-454页

作者： Xuan guo Jun Luo Heng Wang jiong Chen State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animals for Disease Study Model Animal Research CenterNanjing UniversityNanjing210061China College of Life Science Shangrao Normal UniversityShangrao334001China

Characterized by multicellular migratory behavior and cooperative ability,collective cell migration plays critical roles in developmental,physiological and pathological processes,such as organogenesis,wound healing and tumor metastasis (Friedl and Gilmour,2009).Molecular features of collective cell migration including collective polarization,coordinated cytoskeletal activity,and guidance signaling have been recently investigated in a variety of in vivo and in vitro model systems (Scarpa and Mayor,2016),but many other aspects of regulatory mechanisms remain unexplored.

关键词： homeostasis healing collective

Double-directional control bolt support technology and engineering application at large span Y-type intersections in deep coal mines

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Mining Science and Technology 2010年第2期20卷 254-259页

作者： guo, Zhibiao SHI, Jianjun WANG, jiong CAI, Feng WANG, Fuqiang state key laboratory of geomechanics and deep underground engineering beijing 100083china institute of geotechnical engineering china university of mining & technologybeijing 100083china safety engineering college north china university of science & technologybeijing 101601china

Under deep and complex geological conditions,severe deformation occurs at intersection points of Y-type roadways with large cross sections during engineering projects in coal mines,especially at junction *** on in-situ investigations and theoretical studies,we have summarized typical forms of destruction and identified high stress and unrestricted support at both sides of junction arch as its main *** this study,we also presented double-directional control bolt support technology for a large Y-type span intersection,applied to deep intersection engineering in the Jiahe Coal Mine,which has proved effective.

关键词： Y-type intersection double-directional control bolt support deep coal mines

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面向学科能力培养的单元教学设计模型研究

电化教育研究 2022年第7期43卷 81-88页

作者：郭炯潘霞西北师范大学教育技术学院甘肃兰州730070

核心素养教育是当前教育变革的核心主题,基于学科能力的单元教学不仅是对核心素养教育的基本回应,也是推动核心素养落地的现实需要。通过单元教学的方式促进核心素养发展,需厘清核心素养导向下单元教学设计要点与逻辑,建构面向学科能力... 详细信息

核心素养教育是当前教育变革的核心主题,基于学科能力的单元教学不仅是对核心素养教育的基本回应,也是推动核心素养落地的现实需要。通过单元教学的方式促进核心素养发展,需厘清核心素养导向下单元教学设计要点与逻辑,建构面向学科能力培养的单元教学设计模型。该模型源自脑的学习机理、心理认知规律,探索单元教学中学科能力的培养机制,立足大数据、人工智能、虚拟现实等技术赋能单元教学的认知价值,围绕单元目标,明确了课程分析、内容重构、活动设计、评价设计等核心要素,并以“大”为切入点,探究大概念、大整合、大任务、大进阶所揭示的实施逻辑。在此基础上,设计面向学科能力的单元教学案例,详细阐述单元教学设计流程与策略,希冀为单元教学提供理论解释与实践指导。

关键词：学科能力单元教学设计模型学科核心素养大概念

农村中小学教师数字素养提升:价值意蕴、现实困境及策略探析

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电化教育研究 2023年第8期44卷 122-128页

作者：张靖郭炯西北师范大学教育技术学院甘肃兰州730070

在教育数字化转型背景下,农村中小学教师数字素养亟待有效提升,以帮助农村教师应对日益严峻的数字化挑战。本研究认为,提升农村中小学教师数字素养是农村教育数字化转型的动力源泉,能够持续赋能数字化转型走向纵深;有利于教师适应新技... 详细信息

在教育数字化转型背景下,农村中小学教师数字素养亟待有效提升,以帮助农村教师应对日益严峻的数字化挑战。本研究认为,提升农村中小学教师数字素养是农村教育数字化转型的动力源泉,能够持续赋能数字化转型走向纵深;有利于教师适应新技术、新模式,从而创新教育教学体验;有助于推进城乡教育一体化发展,为农村学生带来高质量的教育资源;能够带动农村学生数字素养提升,有效弥补城乡学生间的“数字鸿沟”等。提升过程中存在的现实困境有:农村中小学教师自身提升意愿较弱、农村教师研修仍存在诸多现实桎梏、难以准确评价并表征教师数字素养等。对此,应以智慧教育平台为“桥梁”缩减城乡教师提升动力差,强化农村中小学教师提升积极性;以农村教师真实需求为“蓝本”开展循证式研修,提升研修定位的准确性与实施的有效性;以数字徽章为“支点”,撬动农村中小学教师数字素养评价及表征难题。

关键词：数字素养数字徽章农村中小学教师教师研修

On the Distribution of Laplacian Eigenvalues of a Graph

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Acta Mathematica Sinica,English Series 2011年第11期27卷 2259-2268页

作者： Ji Ming guo Xiao Li WU jiong Ming ZHANG Kun Fu FANG Department of Applied Mathematics China University of Petroleum Dongying 257061 P. R. China Faculty of Science Huzhou Teachers College Huzhou 313000 P. R. China

This paper presents some bounds on the number of Laplacian eigenvalues contained in various subintervals of [0, n] by using the matching number and edge covering number for G, and asserts that for a connected graph the Laplacian eigenvalue 1 appears with certain multiplicity. Furthermore, as an application of our result （Theorem 13）, Grone and Merris＇ conjecture [The Laplacian spectrum of graph II. SIAM J. Discrete Math., 7, 221-229 （1994）] is partially proved.

关键词： Laplacian eigenvalue matching number edge covering number pendant neighbor