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Extension of covariant derivative(Ⅰ): From component form to objective form

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Acta Mechanica Sinica 2015年第1期31卷 79-87页

作者： ya-jun Yin Department of Engineering Mechanics School of AerospaceTsinghua University

This paper extends the covariant derivative un der curved coordinate systems in 3D Euclid space. Based on the axiom of the covariant form invariability, the classical covariant derivative that can only act on components is ex tended to the generalized covariant derivative that can act on any geometric quantity including base vectors, vectors and tensors. Under the axiom, the algebra structure of the gen eralized covariant derivative is proved to be covariant dif ferential ring. Based on the powerful operation capabilities and simple analytical properties of the generalized covariant derivative, the tensor analysis in curved coordinate systems is simplified to a large extent.

关键词： Tensor analysis Classical covariant derivatives Generalized covariant derivatives The axiom of the covari-ant form invariability Covariant differential ring

Extension of covariant derivative(Ⅱ): From flat space to curved space

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Acta Mechanica Sinica 2015年第1期31卷 88-95页

作者： ya-jun Yin Department of Engineering Mechanics School of Aerospace Tsinghua University

This paper extends the classical covariant deriva tive to the generalized covariant derivative on curved sur faces. The basement for the extension is similar to the pre vious paper, i.e., the axiom of the covariant form invariabil ity. Based on the generalized covariant derivative, a covari ant differential transformation group with orthogonal duality is set up. Through such orthogonal duality, tensor analy sis on curved surfaces is simplified intensively. Under the covariant differential transformation group, the differential invariabilities and integral invariabilities are constructed on curved surfaces.

关键词： Tensor analysis on curved surfaces Classicalcovariant derivative and generalized covariant derivative Axiom of the covariant form invariability Covariant differ-ential transformation group Differential invariabilities andintegral invariabilities

Extension of covariant derivative(Ⅲ): From classical gradient to shape gradient

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Acta Mechanica Sinica 2015年第1期31卷 96-103页

作者： ya-jun Yin Department of Engineering Mechanics School of Aerospace Tsinghua University

This paper further extends the generalized covari ant derivative from the first covariant derivative to the sec ond one on curved surfaces. Through the linear transforma tion between the first generalized covariant derivative and the second one, the second covariant differential transformation group is set up. Under this transformation group, the sec ond class of differential invariants and integral invariants on curved surfaces is made clear. Besides, the symmetric struc ture of the tensor analysis on curved surfaces are revealed.

关键词： Tensor analysis on curved surfaces The sec-ond generalized covariant derivative The second covariantdifferential transformation group The second class of dif-ferential and integral invariants

Structural engineering of high-entropy alloys for advanced electrocatalytic reactions

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Tungsten 2025年第1期 1-31页

作者： Qiao Xie Ying-Jie Yu Hai-jun Zhang ya-Ping Deng Wen lei The State Key laboratory of Refractories and Metallurgy Wuhan University of Science and Technology Department of Chemical Engineering Waterloo Institute for Sustainable Energy Waterloo Institute for Nanotechnology University of Waterloo

High-entropy alloys(HEAs) have emerged as promising candidates to replace traditional precious metal catalysts,owing to their unique chemical and physical *** review commences by revisiting the fundamental concepts of HEAs,including their synthesis methods and structural control strategies in *** underscores the critical role of meticulously manipulating both macroscopic and microscopic structures of the HEAs to optimize their catalytic performance.A deep understanding of the structure-activity relationship in HEAs across various configurations is pivotal in developing more effective *** review methodically encapsulates the research progress of structural control strategies for HEAs in achieving efficient energy conversion,with the aim of gaining a better understanding of the relationship between structure and *** review concludes by summarizing the current achievements and challenges,and suggestions for potential future directions of HEAs in the fields of energy conversion and environmental purification.

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Facile and One-step Direct Synthesis of Poly(valine)as a Robust Drug Nanocarrier for Enhanced Breast Cancer Therapy

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Chinese Journal of Polymer Science 2022年第9期40卷 1016-1027页

作者： ya-Bin Meng jun Wu School of Biomedical Engineering Sun Yat-sen UniversityShenzhen 518107China

Synthetic poly(amino acid)s with good biodegradable and biocompatible properties have attracted increased attention as carriers in biomedical applications in recent years,their synthesis and purification procedures are usually complicated and some by-products would occur *** this,polypeptide with good biodegradable and biocompatible properties is prepared and optimized by one-step and direct synthesis strategy and poly(valine)(PVal)is selected here as a model polypeptide in this *** newly generated PVal can self-assemble into poly(valine)nanoparticles(PVal-NPs)with a high drug-loading capacity(>20 wt%)of doxorubicin(DOX)and shows strong cytotoxicity against 4T1 *** cellular internalization,the release of DOX could be accelerated by the endosomal acidic environment which leads to enhanced anticancer *** results in vivo show that DOX@PVal-NPs have a long blood circulation time,high cancer accumulation and penetration,and good therapeutic performance in 4T1 tumor-bearing mice without causing obvious adverse effect on main *** these combined advantages,these PVal-based nanoplatform would provide an effective drug delivery tool for clinical breast cancer therapy.

关键词： Poly(amino acid) Nanoparticle Drug carrier Doxorubicin Breast cancer

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提高激素性股骨头坏死模型成活率的方法

中国组织工程研究 2013年第50期17卷 8729-8734页

作者：李瑞琦张国平李宜炯李亚丽任立中张宇宸王伟高宏阳吕亚军河北医科大学第一医院骨科河北省石家庄市050031

背景:激素性股骨头坏死动物模型建立过程中动物的死亡成为影响实验结果的主要因素。目的:观察以脂多糖和地塞米松建立股骨头坏死模型,提高模型成功率的方法。方法:新西兰大白兔48只随机等分为模型组、庆大霉素组、庆大霉素+兰索拉唑组... 详细信息

背景:激素性股骨头坏死动物模型建立过程中动物的死亡成为影响实验结果的主要因素。目的:观察以脂多糖和地塞米松建立股骨头坏死模型,提高模型成功率的方法。方法:新西兰大白兔48只随机等分为模型组、庆大霉素组、庆大霉素+兰索拉唑组和对照组,前3组连续2 d经耳缘静脉注射脂多糖,再连续3 d,臀部肌肉注射地塞米松注射液建立股骨头坏死模型,庆大霉素组和庆大霉素+兰索拉唑组在建模成功后连续7 d以庆大霉素灌胃,同时庆大霉素+兰索拉唑组肌肉注射兰索拉唑注射液。对照组兔仅注射生理盐水。结果与结论:模型组、庆大霉素组和庆大霉素+兰索拉唑组均造模成功;其中庆大霉素+兰索拉唑组存活状况最好,3组动物死亡率分别是33.3%,25%,8.3%,模型组、庆大霉素组、庆大霉素组+兰索拉组和对照组兔的死亡数量差异有显著性意义(P<0.05)。提示在兔激素性股骨头坏死模型建立中,庆大霉素+兰索拉唑的使用,可以提高实验动物的生存率。

关键词：组织构建组织构建实验造模内毒素脂多糖地塞米松股骨头坏死动物模型致死原因兰索拉唑药物干预

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激素性股骨头坏死模型:不同构建技术分析

中国组织工程研究 2013年第37期17卷 6676-6681页

作者：李瑞琦张国平李宜炯李亚丽任立中张宇宸王伟高宏阳吕亚军河北医科大学第一医院骨科河北省石家庄市050031

背景:良好的股骨头坏死动物模型的建立,有助于研究股骨头坏死的发病机制,为股骨头坏死的预防和治疗提供理论依据。目的:研究内毒素脂多糖联合地塞米松注射液诱导兔股骨头坏死的实验效果。方法:新西兰大白兔36只随机分为模型组21只和对照... 详细信息

背景:良好的股骨头坏死动物模型的建立,有助于研究股骨头坏死的发病机制,为股骨头坏死的预防和治疗提供理论依据。目的:研究内毒素脂多糖联合地塞米松注射液诱导兔股骨头坏死的实验效果。方法:新西兰大白兔36只随机分为模型组21只和对照组15只。模型组连续2 d每日经耳缘静脉注射内毒素脂多糖10μg/kg,再连续3 d,每日肌肉注射地塞米松注射液25 mg/kg;对照组注射同等剂量的生理盐水。结果与结论:模型组4周后X射线显示兔关节间隙增宽,密度增大,关节软骨下骨密度增高,股骨头变平,骨小梁模糊,软骨下骨与骨松质界限不清,在股骨头内出现斑块状高密度区域,股骨颈变短粗。双能量X射线骨密度测量仪进行股骨头局部骨密度测量,兔股骨头骨密度检测发现模型组股骨头骨密度、骨矿物质含量均显著低于对照组(P<0.05)。组织学切片见模型组骨细胞陷窝空疏,脂肪细胞增多,部分血管栓塞,其中存活动物的骨坏死率和骨陷窝率均明显高于对照组。证实地塞米松联合脂多糖可有效建立激素性股骨头坏死模型。

关键词：股骨头坏死地塞米松骨密度骨坏死模型,动物

Valley switch effect in anα-T3 lattice-based superconducting interferometer

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Chinese Physics B 2024年第11期33卷 372-377页

作者： ya-jun Wei jun Wang School of Physics Southeast UniversityNanjing 210096China

Dirac electrons possess a valley degree of freedom,which is currently under investigation as a potential information *** propose an approach to generate and manipulate the valley-switching current(VSC)through Andreev reflection using an interferometer-based superconductor hybrid *** interferometer comprises a ring-shaped structure formed by topological kink states in the a-T3 lattice via carefully designed electrostatic *** results demonstrate the feasibility of achieving a fully polarized VSC in this device without contamination from cotunneling electrons sharing the same valley as the incident ***,we show that control over the fully polarized VSC can be achieved by applying a nonlocal gate voltage or modifying the global parameter *** former alters the dynamic phase of electrons while the latter provides an a-dependent Berry phase,both directly influencing quantum interference and thereby affecting performance in terms of generating and manipulating VSC,crucial for advancements in valleytronics.

关键词： valley switch effect valleytronics Andreev reflection a-T3 lattice

Synchrotron infrared spectral regions as signatures for foodborne bacterial typing

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Nuclear Science and Techniques 2019年第2期30卷 109-113页

作者： ya-Di Wang Xue-ling li jun Hu jun-Hong lü Division of Physical Biology and CAS Key laboratory of Interfacial Physics and Technology Shanghai Institute of Applied PhysicsChinese Academy of Sciences (CAS) University of Chinese Academy of Sciences Shanghai Center for Bioinformation Technology Shanghai Industrial Technology Institute

Fourier-transform infrared(FTIR) spectroscopy has emerged as a viable alternative to biochemical and molecular biology techniques for bacterial typing with advantages such as short analysis time, low cost and laboratorial simplicity. In this study, synchrotron radiationbased FTIR(SR-FTIR) spectroscopy with higher spectral quality was successfully applied to type 16 foodborne pathogenic bacterial strains. Combined with principal component analysis(PCA) and hierarchical cluster analysis(HCA), we found that the specific spectral region1300-1000 cm^(-1), which reflects the information of phosphate compounds and polysaccharides, can be used as the signature region to cluster the strains into groups similar with genetic taxonomic method. These findings demonstrated that FTIR spectra combined with HCA have a great potential in quickly typing bacteria depending on their biochemical signatures.

关键词： Synchrotron radiation FTIR Spectral signature Bacterial typing PCA HCA