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Twisted Integration of Complex Oxide Magnetoelectric Heterostructures via Water‑Etching and Transfer Process

Nano-Micro Letters 2024年第1期16卷 360-369页

作者： Guannan Yang guohua dong Butong Zhang Xu Xu Yanan Zhao Zhongqiang Hu Ming Liu State Key Laboratory for Manufacturing Systems Engineering Electronic Materials Research LaboratoryKey Laboratory of the Ministry of EducationEngineering Research Center of Spin Quantum Sensor ChipsUniversities of Shaanxi ProvinceSchool of Electronic Science and EngineeringXi’an Jiaotong UniversityXi’an 710049People’s Republic of China

Manipulating strain mode and degree that can be applied to epitaxial complex oxide thin films have been a cornerstone of strain *** recent years,lift-off and transfer technology of the epitaxial oxide thin films have been developed that enabled the integration of heterostructures without the limitation of material types and crystal ***,twisted integration would provide a more interesting strategy in artificial magnetoelectric heterostructures.A specific twist angle between the ferroelectric and ferromagnetic oxide layers corresponds to the distinct strain regulation modes in the magnetoelectric coupling process,which could provide some insight in to the physical *** this work,the La_(0.67)Sr_(0.33)MnO_(3)(001)/0.7Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.3PbTiO_(3)(011)(LSMO/PMN-PT)heterostructures with *** *** angles were assembled via water-etching and transfer *** transferred LSMO films exhibit a fourfold magnetic anisotropy with easy axis along LSMO.A coexistence of uniaxial and fourfold magnetic anisotropy with LSMO[110]easy axis is observed for the 45°Sample by applying a 7.2 kV cm^(−1)electrical field,significantly different from a uniaxial anisotropy with LSMO[100]easy axis for the 0°*** fitting of the ferromagnetic resonance field reveals that the strain coupling generated by the 45°twist angle causes different lattice distortion of LSMO,thereby enhancing both the fourfold and uniaxial *** work confirms the twisting degrees of freedom for magnetoelectric coupling and opens opportunities for fabricating artificial magnetoelectric heterostructures.

关键词： Magnetoelectric heterostructures Twist angle Epitaxial lift-off Magnetic anisotropy Ferromagnetic resonance

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汉字谐声与明清上古音研究分期述论

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海峡人文学刊 2024年第2期4卷 91-95,104,158页

作者：董国华广东海洋大学文学与新闻传播学院广东湛江524088

步南宋遗绪,明清两代的古音学家在“说文学”勃兴的浪潮中,完善以谐声推求古音的理论和方法,编撰诸多可谓“后出转精”的谐声韵谱,力求得到更为合理的古韵分部。根据各家对谐声材料,尤其对《说文》的认识和利用程度及其对古音学史的贡献... 详细信息

步南宋遗绪,明清两代的古音学家在“说文学”勃兴的浪潮中,完善以谐声推求古音的理论和方法,编撰诸多可谓“后出转精”的谐声韵谱,力求得到更为合理的古韵分部。根据各家对谐声材料,尤其对《说文》的认识和利用程度及其对古音学史的贡献,可将明代杨慎、陈第、赵宧光,清代顾炎武、潘咸、万光泰等二十余位古音学家以汉字谐声材料研究上古音的演进历程,分为明代的萌芽与探索期,清代的奠基与勃发期、成熟与兴盛期和融合与消退期四个主要阶段,并通过对比和分析,评述诸家的贡献和不足。

关键词：汉字谐声上古音古韵分部分期

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管状g-C_(3)N_(4)/CQDs复合物制备及其光催化降解亚甲基蓝

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高师理科学刊 2024年第5期44卷 66-71页

作者：韩鹏达吴寒侯旭董国华齐齐哈尔大学化学与化学工程学院黑龙江齐齐哈尔161006

以汉麻叶和氟化铵为原料,利用微波醇溶剂热法制备碳量子点(CQDs),然后通过搅拌旋蒸将CQDs负载到三聚氰胺和三聚氰酸的复合物前驱体上,烘干后再利用煅烧法制备了g-C_(3)N_(4)/CQDs复合物光催化剂,对其结构、组成和形貌表征分析后,通过降... 详细信息

以汉麻叶和氟化铵为原料,利用微波醇溶剂热法制备碳量子点(CQDs),然后通过搅拌旋蒸将CQDs负载到三聚氰胺和三聚氰酸的复合物前驱体上,烘干后再利用煅烧法制备了g-C_(3)N_(4)/CQDs复合物光催化剂,对其结构、组成和形貌表征分析后,通过降解亚甲基蓝(MB)评价其光催化性能.结果表明,引入CQDs致使g-C_(3)N_(4)/CQDs呈现管状形貌,且具有更高的可见光响应能力.与空白g-C_(3)N_(4)相比,g-C_(3)N_(4)/CQDs复合物表现出更高的光催化降解能力,在可见光照射下,120 min对MB的降解效率达到80.8%,而空白g-C_(3)N_(4)仅为31.9%,提高了1.53倍.机理分析表明,光催化性能的提高主要归咎于催化剂改善的形貌结构,提高的可见光响应和碳量子点加速了光电荷迁移速率.

关键词：碳量子点 g-C_(3)N_(4) 光催化亚甲基蓝

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基于经验频率分布的偏态概率模型可靠度计算方法研究

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四川建筑科学研究 2024年第1期50卷 52-59页

作者：冉志红董国华杨子富林帆云南大学建筑与规划学院云南昆明650091

在既有结构可靠度计算中,经验频率分布较容易通过简单的序列计算得到。利用经验频率分布回归得到的正态概率模型或偏态概率模型可以计算相关统计参数、失效概率和可靠指标。大量的计算和比较分析得出,偏态概率模型在工程实践中具有更好... 详细信息

在既有结构可靠度计算中,经验频率分布较容易通过简单的序列计算得到。利用经验频率分布回归得到的正态概率模型或偏态概率模型可以计算相关统计参数、失效概率和可靠指标。大量的计算和比较分析得出,偏态概率模型在工程实践中具有更好的适应性。数值计算结果也进一步表明,用正态分布进行近似,其可靠指标的误差较大,甚至会影响既有结构的评估结果。提出了基于Azzalini偏态分布函数的参数估计方法,并利用失效概率作为联系纽带,建立了偏态分布下失效概率与可靠指标之间的函数关系。以某较为复杂的功能函数为例,展示了所提出的基于经验频率分布的偏态概率模型可靠度计算方法,该方法具有步骤清晰、目标明确、精度较高的优点,能够适用于更加广泛的实际既有工程结构可靠度的评估。

关键词：工程结构可靠度经验频率分布偏态概率模型既有结构评估

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Large electrical strain in lead-free K_(0.5)Na_(0.5)NbO_(3)-based ceramics by heterovalent doping

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Journal of Materiomics 2023年第5期9卷 959-970页

作者： Xiangjian Wang Jun Wang Wenping Geng guohua dong Brahim Dkhil Xiaojie Lou Department of Information Engineering Quzhou College of TechnologyQuzhou324000China Frontier Institute of Science and Technology and State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China Science and Technology on Electronic Test and Measurement Laboratory North University of ChinaTaiyuan030051China Electronic Materials Research Laboratory Key Laboratory of the Ministry of Education&International Center for Dielectric ResearchXi'an Jiaotong UniversityXi'an710049China Applied Physics Division of Materials ScienceDepartment of Engineering Sciences and MathematicsLuleåUniversity of TechnologySE-97187LuleåSweden Laboratoire Structures Proprietes et Modelisation des SolidesUniversite Paris SaclayCentraleSupelecCNRS-UMR8580Grande Voie des VignesCh^atenay MalabryCedex92295France

Heterovalent doped(K_(0.48-0.07)xNa_(0.52-0.43)xBi_(0.5)x)(Nb_(0.95-0.95x)Sb_(0.05-0.05x)Zrx)O_(3)ceramics were fabricated using conventional solid-state ***,the phase structures,dielectric,ferroelectric,and electricstrain properties were *** compositions were tuned to be located at polymorphic phase boundary with increasing heterovalent Bi3t and Zr4t doping levels.A large strain of 0.19%was obtained at relatively low electric fields of 30 kV/cm in the composition of x=*** normalized large-signal d33*values were approximately 633 pm/V under a low driving electric field of 30 kV/cm,which were comparable or larger than the values reported for other lead-free *** large strains obtained can be attributed to the formation of nanodomains and high-density domain walls,which were confirmed by the observations of domain morphology using transmission electron microscopy(TEM)*** temperature stability of the strain properties of the x=0.04 sample could be ascribed to the sluggish behaviour for the local structural heterogeneity in heterovalent-ion doped KNN *** simulations revealed that the Zr^(4t)produce the local stress at the BO6 octahedra and Bi3t could yield off-centering of AO12 ployhedron due to the nature of Bi 6s lone pair electrons,which induced lattice expansion and local distortions in the *** local displacements are strongly anisotropic in heterovalent-ion doped *** is believed that random local fields exist in these compositions owing to the eixstence of charge *** heterovalent doping of Bi^(3t)and Zr^(4t)could destory simultaneously the orthorhombic symmetry and the short-range ferroelecctric order,leading to the formation of complex nanodomains and local structral *** doping may,therefore,offer a new avenve to design novel K0.5Na0.5NbO3(KNN)-based materials for their mutifunctional applications.

关键词： Lead-free Strain Heterovalent doping Local structure Nanodomain

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工程结构椭球凸集模型可靠度的二次型计算方法研究

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四川建筑科学研究 2024年第2期50卷 25-31页

作者：冉志红凌枫董国华谢璐源林帆云南大学建筑与规划学院云南昆明650091

工程结构概率可靠度在理论上已经建立了完整的计算体系,但在实际工程应用中却停留在近似或半经验阶段。对于既有工程结构的可靠度评估,由于测试数据有限,采用椭球凸集模型可靠度进行评估有很高的工程价值和广泛的应用前景。椭球凸集模... 详细信息

工程结构概率可靠度在理论上已经建立了完整的计算体系,但在实际工程应用中却停留在近似或半经验阶段。对于既有工程结构的可靠度评估,由于测试数据有限,采用椭球凸集模型可靠度进行评估有很高的工程价值和广泛的应用前景。椭球凸集模型可靠度有很多种不同的定义,但无论何种定义,如果完全脱离概率可靠度与失效概率的基本假定,则很难与现在基于概率可靠度评估方法的主流实现有效的衔接。从多维正态联合概率密度出发,推导了斜椭球方程及其标准化方法,同时结合极限状态方程,给出了椭球凸集模型可靠度与概率可靠度之间的数学关系。算例表明,得出的特殊简化情况下的椭球凸集模型可靠度计算方法和几何解释,可进一步推动该类可靠度在工程中的应用。

关键词：结构可靠度椭球凸集模型工程结构可靠度极限状态方程

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Stress-induced controllable magnetic properties in flexible epitaxial Mn_(0.5)Zn_(0.5)Fe_(2)O_(4) ferrite films

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Journal of Materiomics 2022年第3期8卷 596-600页

作者： Tian Wang guohua dong Yuxuan Ma Haixia Liu Ziyao Zhou Ming Liu Electronic Materials Research Laboratory Key Laboratory of the Ministry of Education&International Center for Dielectric ResearchSchool of Electronic and Information EngineeringState Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China

Flexible ferrite film has high potential applications in electronic skins and wearable ***,it is an enormous challenge to fabricate flexible ferrite film because of its high *** work uses a novel etching sacrificial Sr_(3)Al_(2)O_(6)(SAO)layer to synthesize flexible Mn_(0.5)Zn_(0.5)Fe_(2)O_(4)(MZFO)ferrite *** MZFO film remains its single crystal structure after being transferred onto a flexible *** to the great lattice mismatch between SAO and MZFO,the as-grown and transferred MZFO films exhibit the difference in magnetic properties,which is more sensitive along out-of-plane *** controllable magnetic properties of the film under the bending test are characterized by ferromagnetic resonance(FMR).A huge FMR field(Hr)shift of 704 Oe is achieved along out-of-plane direction when the bending radii are 5 ***,the FMR linewidth(dH)of bent MZFO film(1267 Oe)is about 4 times higher than that of the unbent film(310 Oe).These controllable changes mainly come from the contribution of the two magnon scattering(TMS)***,the Hr and dH almost return to their initial states when the stress is released,indicating a great recoverability.

关键词： ferrite film magnetic

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Lateral root elongation in maize is related to auxin synthesis and transportation mediated by N metabolism under a mixed NO_(3)^(–) and NH_(4)^(+) supply

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Journal of Integrative Agriculture 2024年第3期23卷 1048-1060页

作者： Peng Wang Lan Yang Xichao Sun Wenjun Shi Rui dong Yuanhua Wu guohua Mi Key Laboratory of Tobacco Biology and Processing of Ministry of Agriculture and Rural Affairs Tobacco Research InstituteChineseAcademy of Agricultural SciencesQingdao 266101China Department of Plant Nutrition College of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China College of Resources Hunan Agricultural UniversityChangsha 410128China Agro-Environmental Protection Institute Ministry of Agriculture and Rural AffairsTianjin 300191China

A mixed nitrate (NO_(3)^(–)) and ammonium (NH_(4)^(+)) supply can promote root growth in maize (Zea mays),however,the changes in root morphology and the related physiological mechanism under different N forms are still ***,maize seedlings were grown hydroponically with three N supplied in three different forms (NO_(3)^(–)only,75/25 NO_(3)^(–)/NH_(4)^(+)and NH_(4)^(+)only).Compared with sole NO_(3)^(–)or NH_(4)^(+),the mixed N supply increased the total root length of maize but did not affect the number of axial *** main reason was the increased total lateral root length,while the average lateral root (LR) length in each axle was only slightly *** addition,the average LR density of 2nd whorl crown root under mixed N was also *** with sole nitrate,mixed N could improve the N metabolism of roots (such as the N influx rate,nitrate reductase (NR) and glutamine synthase (GS)enzyme activities and total amino content of the roots).Experiments with exogenously added NR and GS inhibitors suggested that the increase in the average LR length under mixed N was related to the process of N assimilation,and whether the NR mediated NO synthesis participates in this process needs further ***,an investigation of the changes in root-shoot ratio and carbon (C) concentration showed that C transportation from shoots to roots may not be the key factor in mediating lateral root elongation,and the changes in the sugar concentration in roots further proved this ***,the synthesis and transportation of auxin in axial roots may play a key role in lateral root elongation,in which the expression of ZmPIN1B and ZmPIN9 may be involved in this *** study preliminarily clarified the changes in root morphology and explored the possible physiological mechanism under a mixed N supply in maize,which may provide some theoretical basis for the cultivation of crop varieties with high N efficiency.

关键词： maize NO_(3)^(–)/NH_(4)^(+)ratio lateral root elongation N assimilation indole-3-acetic acid

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Effect of Tb Doping on Structural and Electrical Properties of BiFeO_3 Thin Films Prepared by Sol-Gel Technique

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Journal of Materials Science & Technology 2014年第4期30卷 365-370页

作者： guohua dong Guoqiang Tan Wenlong Liu Ao Xia Huijun Ren Key Laboratory of Auxiliary Chemistry & Technology for Chemical Industry Ministry of EducationShaanxi University of Science & Technology

Bil_xTbxFe03 thin films were prepared on Sn02 （fluorine doped tin oxide） substrates by a sol-gel method. The structural and electrical properties of the BiFe03 thin films were characterized and tested. The results indicated that the diffraction peak of the Tb-doped BiFe03 films was shifted towards right as the doping amounts were increased. The structure was transformed from the rhombohedral to tetragonal/orthorhombic phase. The ***.11Fe03 thin film showed the well-developed P-E loops, which enhanced remnant polarization （Pr = 88.05 μC/cm2） at room temperature. The dielectric constant and dielectric loss of ***03 thin film at 100 kHz were 185 and 0.018, respectively. Furthermore, the ***03 thin film showed a relatively low leakage current density of 2.07×10-5 A/cm2 at an applied electric field of 150 kV/cm. The X- ray photoelectron spectroscopy （XPS） spectra indicated that the presence of Fe2＋ ions in the ***.11Fe03 thin film was less than that in the pure BiFe03.

关键词： BiFeO3 thin films Tb doping Sol-gel method Ferroelectric properties

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Synthesis of Bis-benzimidazolium Cyclic Receptors and Their Anion Binding Properties

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Chinese Journal of Chemistry 2013年第5期31卷 673-678页

作者： Xiaozhi Jiang Meiyun Feng Dawei Zhang Binshen Wang Zhiyun dong guohua Gao Shanghai Key Laboratory of Green Chemistry and Chemical Processes Department of Chemistry East China Normal University 3663 North Zhongshan Road Shanghai 200062 China

A series of cyclic receptors 1--5 based on bis-benzimidazolium group were designed and synthesized. Their anion recognition properties were investigated by UV-vis, fluorescent spectroscopy, 1H NMR and MALDI-TOF mass spectrometry. The UV-vis and fluorescent spectroscopic studies showed that the receptors 1--5 had different binding abilities for various anions such as fluoride, chloride, bromide, iodide and acetate. The high selectivity of the receptors for fluoride and acetate anions is attributed to their basicity. Job plot and MALDI-TOF mass spec- trometry demonstrated that the receptors form 1 ： 1 complex with fluoride. DFT calculation and 1H NMR studies indicated that the receptors bind anions through （C--H）＋…X- hydrogen bond.

关键词： cyclic ionic receptors bis-benzimidazolium anion recognition hydrogen bond

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