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Unconventional phonon spectra and obstructed edge phonon modes

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 114-118页

作者： Ruihan Zhang Haohao Sheng Junze Deng Zhong Fang Zhilong Yang zhijun wang Beijing National Laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Based on the elementary band representations(EBR),many topologically trivial materials are classified as unconventional ones(obstructed atomic limit),where the EBR decomposition for a set of electronic states is not consistent with atomic valenceelectron band *** the work,we identify that the unconventional nature can also exist in phonon spectra,where the EBR decomposition for a set of well-separated phonon modes is not consistent with atomic vibration band representations(ABR).The unconventionality has two types:typeⅠis on an empty site;and typeⅡis on an atom site with non-atomic vibration *** unconventionality is described by the nonzero real-space invariant at the *** detailed calculations show that the black phosphorus(BP)has the typeⅠunconventional phonon spectrum,while 1H-Mo Se_(2)has the typeⅡone,although their electronic structures are also ***,the obstructed phonon modes are obtained for two types of unconventional phonon spectra.

关键词： unconventional phonon spectra obstructed edge phonon mode typeⅠ&typeⅡunconventionality

Properties of Self-recoverable Mechanoluminescence Phosphor Ca_(5)Ga_(6)O_(14)∶Eu^(3+)and Its Information Encryption Application

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发光学报 2024年第9期45卷 1445-1455页

作者： ZHANG Ting wang zhijun wang Dawei ZHAO Jinxin YANG Zhiping LI Panlai Hebei Key Laboratory of Optic-electronic Information and Materials College of Physics Science&TechnologyHebei UniversityBaoding 071002China Hebei Key Laboratory of Semiconductor Lighting and Display Critical Materials Hebei Ledphor Optoelectronics Technology Co.LTD.Baoding 071000China

A novel self-recoverable mechanoluminescent phosphor Ca_(5)Ga_(6)O_(14)∶Eu^(3+)was developed by the high-tem-perature solid-state reaction method,and its luminescence properties were ***_(5)Ga_(6)O_(14)∶Eu^(3+)can produce red mechanoluminescence,and importantly,it shows good *** mechanoluminescence of Ca_(5)Ga_(6)O_(14)∶Eu^(3+)re-sults from the piezoelectric field generated inside the material under stress,rather than the charge carriers stored in the traps,which can be confirmed by the multiple cycles of mechanoluminescence tests and heat treatment *** mechanoluminescence color can be turned from red to green by co-doping varied concentrations of Tb^(3+),which may be meaningful for encrypted letter *** encryption scheme for secure communication was devised by harness-ing mechanoluminescence patterns in diverse shapes and ASCII codes,which shows good encryption *** results suggest that the mechanoluminescence phosphor Ca_(5)Ga_(6)O_(14)∶Eu^(3+),Tb^(3+)may be applied to the optical infor-mation encryption.

关键词： phosphor mechanoluminescence self-recoverable information encryption

Instance segmentation from small dataset by a dual-layer semantics-based deep learning framework

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Science China(Technological Sciences) 2024年第9期67卷 2817-2833页

作者： CHEN YiMing LI JianWei HU XiaoBing LIU YiRui MA JianKai XING Chen LI JunJie wang zhijun wang JinCheng State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

Efficient and accurate segmentation of complex microstructures is a critical challenge in establishing process-structure-property(PSP) linkages of materials. Deep learning(DL)-based instance segmentation algorithms show potential in achieving this ***, to ensure prediction reliability, the current algorithms usually have complex structures and demand vast training *** overcome the model complexity and its dependence on the amount of data, we developed an ingenious DL framework based on a simple method called dual-layer semantics. In the framework, a data standardization module was designed to remove extraneous microstructural noise and accentuate desired structural characteristics, while a post-processing module was employed to further improve segmentation accuracy. The framework was successfully applied in a small dataset of bimodal Ti-6Al-4V microstructures with only 112 samples. Compared with the ground truth, it realizes an 86.81% accuracy IoU for the globular αphase and a 94.70% average size distribution similarity for the colony structures. More importantly, only 36 s was taken to handle a 1024 × 1024 micrograph, which is much faster than the treatment of experienced experts(usually 900 s). The framework proved reliable, interpretable, and scalable, enabling its utilization in complex microstructures to deepen the understanding of PSP linkages.

关键词： instance segmentation dual-layer semantics deep learning small dataset Ti-6Al-4V

Modulation of starch digestibility using non-thermal processing techniques:A review

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Grain & Oil Science and Technology 2024年第3期7卷 209-218页

作者： Liyuan Rong Weiqi Fei zhijun wang Xianxiang Chen Huiliang Wen Jianhua Xie Mingyue Shen State Key Laboratory of Food Science and Resources Nanchang University School of Biosystems and Food Engineering University College Dublin

Obesity and type 2 diabetes are widespread throughout the world, especially in developed countries. Starch is an important part of human staple food, the modulating of starch digestibility is conducive to reducing postprandial blood glucose levels and alleviating the chronic disease caused by high caloric intake. The digestion properties of starch are correlated with its structural features, including crystallization, amylose/amylopectin ratio, non-starch components, etc. Among the modified methods applied to regulate starch digestibility, non-thermal processing techniques(NTPT) receive extensive attention due to the characteristics of safety, environmental friendliness and high efficiency. The influence and mechanism of NTPT on the digestion properties of starch are discussed in this review, including ultrasounds, high pressure, γ-irradiation, etc. NTPT induces the alternation of morphological and structural characteristics of native starch, changing their sensitivity to enzymes. The effects of NTPT on the digestibility of starch are highly related to the processing parameters and structure characteristics of native starch. The review shows that NTPT is an effective way to modulate the digestion properties of starch and prevent people from suffering from chronic diseases such as obesity and type 2 diabetes.

关键词： Digestibility Non-thermal processing Chronic disease Starch

Excitonic Instability in Ta2Pd3Te5 Monolayer

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Chinese Physics Letters 2024年第9期41卷 57-62页

作者： Jingyu Yao Haohao Sheng Ruihan Zhang Rongtian Pang Jin-Jian Zhou Quansheng Wu Hongming Weng Xi Dai Zhong Fang zhijun wang Beijing National Laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Centre for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE)School of PhysicsBeijing Institute of TechnologyBeijing 100081China Department of Physics Hong Kong University of Science and TechnologyHong Kong 999077China

By systematic theoretical calculations,we reveal an excitonic insulator(EI)in the Ta_(2)Pd_(3)Te_(5)*** bulk Ta_(2)Pd_(3)Te_(5)is a van der Waals(vdW)layered compound,whereas the vdW layer can be obtained through exfoliation or molecular-beam ***-principles calculations show that the monolayer is a nearly zero-gap semiconductor with the modified Becke–Johnson *** to the same symmetry of the band-edge states,the two-dimensional polarization 2D would be finite as the band gap goes to zero,allowing for an EI state in the *** the first-principles many-body perturbation theory,the GW plus Bethe–Salpeter equation calculation reveals that the exciton binding energy is larger than the single-particle band gap,indicating the excitonic *** computed phonon spectrum suggests that the monolayer is dynamically stable without lattice *** findings suggest that the Ta_(2)Pd_(3)Te_(5) monolayer is an excitonic insulator without structural distortion.

关键词： monolayer principles calculations

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王兵的艺术神话与精神复活

美术 2024年第8期 60-63,F0003页

作者：王志军兰州理工大学设计艺术学院

王兵出生在甘南藏区,那种与生俱来的文化品格,艺术成长中的内在精神,已经奠定了他绘画语言的本能与艺术创作的基本走向。对他而言,绘画是与生命意识同步的,忧伤是一种难得的自我疗愈。在成长旅途中,他将生活世界里的经验内化为自己理解... 详细信息

王兵出生在甘南藏区,那种与生俱来的文化品格,艺术成长中的内在精神,已经奠定了他绘画语言的本能与艺术创作的基本走向。对他而言,绘画是与生命意识同步的,忧伤是一种难得的自我疗愈。在成长旅途中,他将生活世界里的经验内化为自己理解万物的方法,甘南的风土人情和生生不息的流变,被描绘成笔下的精神影子,透过其速写、素描、版画、水彩、油画等语言形式,显现契合灵魂的艺术表达,转化成个人处理与世界关系的方法,以此实现自我精神的复活。

关键词：王兵版画超现实精神性

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融合特征的红外与可见光异源图像匹配

激光杂志 2024年第5期45卷 127-132页

作者：王智军王鹏赤峰学院数学与计算机科学学院内蒙古赤峰024000

当前红外和可见光图像配准未考虑灰度、空间的位置情况,匹配结果的平均归一化修正检索秩(A_(r))较高。因此,提出融合特征的红外与可见光异源图像匹配算法。分析待匹配图像的中矩形区域灰度差值特征,绘制Haar特征密度分布图,并基于此实... 详细信息

当前红外和可见光图像配准未考虑灰度、空间的位置情况,匹配结果的平均归一化修正检索秩(A_(r))较高。因此,提出融合特征的红外与可见光异源图像匹配算法。分析待匹配图像的中矩形区域灰度差值特征,绘制Haar特征密度分布图,并基于此实现图像滤波。通过离散变换(K-L)提取滤波后图像灰度特征、像素密度特征和纹理特征,完成多图像特征的压缩与融合。基于融合特征,计算待匹配红外图像与可见光图像的格贴近度,得到异源图像匹配结果。实验结果表明:所提方法应用后,异源图像匹配结果的A_(r)平均值仅为0.35,更好地满足了图像匹配要求。

关键词：红外图像可见光图像纹理特征特征融合格贴近度图像匹配

碳化硅纳米抛光亚表面损伤机理的分子动力学模拟

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机械工程学报 2024年第5期60卷 231-240页

作者：华东鹏周青王婉李硕王志军王海丰西北工业大学凝固技术国家重点实验室西安710072 西北工业大学先进润滑与密封材料研究中心西安710072

碳化硅(SiC)在表面微纳加工过程中损伤机理的研究不足限制了SiC的加工表面质量及应用,因此了解不同抛光参数下SiC的损伤机理对提高SiC的纳米加工表面质量具有重要意义。采用分子动力学模拟研究了单晶SiC在纳米抛光过程中的亚表面损伤机... 详细信息

碳化硅(SiC)在表面微纳加工过程中损伤机理的研究不足限制了SiC的加工表面质量及应用,因此了解不同抛光参数下SiC的损伤机理对提高SiC的纳米加工表面质量具有重要意义。采用分子动力学模拟研究了单晶SiC在纳米抛光过程中的亚表面损伤机理,并考虑了抛光速度和抛光深度的影响。结果表明,随着抛光深度的增加,SiC的去除机制逐渐由以黏附和犁沟机制为主转变为以切削机制为主。微裂纹通过滑移面层间Si-Si键的断裂形成于滑移带尖端。此外,抛光深度越大,工件吸收动能的效率越高,从而导致抛光速度对工件温度和力学性能的影响越显著。因此较小的抛光深度和较大的抛光速度可以获得更好的表面加工质量。这些结果为解释SiC纳米抛光实验中的变形损伤机理提供了新的见解,可以指导设计纳米抛光工艺以获得更好的SiC表面质量。

关键词：碳化硅纳米抛光微裂纹亚表面损伤分子动力学模拟

钢管混凝土柱-钢梁-轻钢主次框架振动台试验研究

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建筑结构学报 2024年第2期45卷 82-94页

作者：杨红苏星宇王志军郑宇睿白久林重庆大学土木工程学院重庆400045 重庆大学山地城镇建设与新技术教育部重点实验室重庆400045

为了增加轻钢框架结构的应用范围,基于主次结构的理念,提出了以钢管混凝土柱-钢梁-斜撑为主结构并形成主要抗侧力体系,以主要承受自身竖向荷载的轻钢框架为次结构的结构体系,其中轻钢次框架以循环嵌套的方式与主结构相结合。为研究轻钢... 详细信息

为了增加轻钢框架结构的应用范围,基于主次结构的理念,提出了以钢管混凝土柱-钢梁-斜撑为主结构并形成主要抗侧力体系,以主要承受自身竖向荷载的轻钢框架为次结构的结构体系,其中轻钢次框架以循环嵌套的方式与主结构相结合。为研究轻钢次框架的结构形式、钢管混凝土柱-钢梁连接节点、次框架采用预制装配式楼板对主次框架结构损伤特征和抗震性能的影响,按7度0.1g设计并制作了2个按1∶3缩尺的6层钢管混凝土柱-钢梁-轻钢主次框架结构模型。对2个模型分别进行振动台试验,分析了其动力特性和地震响应。试验结果表明:2个缩尺模型在7度0.1g罕遇地震作用下均无明显破坏现象,在8度0.2g极罕遇地震下的最大层间位移角分别达到1/28和1/35,但主要结构构件未出现明显损伤;次框架采用铰接梁柱节点并取消第3层钢柱可明显减小水平地震对次框架受力的影响,且可提高装配率、降低造价;刚性法兰连接节点可确保双向水平地震下钢管混凝土柱端先屈服,能满足连接节点更强的抗震要求;经过构造措施加强的次结构预制楼板与边钢梁有明显的组合空间作用,可对边钢梁扭转形成有效约束。

关键词：钢管混凝土柱主次结构轻钢框架结构振动台试验抗震性能