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The room temperature ferromagnetism in highly strained twodimensional magnetic semiconductors

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Journal of Semiconductors 2023年第4期44卷 13-14页

作者： dahai wei State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

In spintronics,it is still a challenge in experiments to realize the ferromagnetic semiconductors with Curie temperature Tc above room temperature.In 2017,the successful synthesis of two-dimensional(2D)van der Waals ferromagnetic semiconductors,including the monolayer CrI3 with Tc=45 K[1]and the bilayer Cr2Ge2Te6 with Tc=28 K[2]in experiments,has attracted extensive attention in the 2D ferromagnetic semiconductors.One of the key problems is to find suitable 2D magnetic semiconductors,which can have room-temperature operation as required in applications.

关键词： temperature semiconductors ferromagnetic

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一种高效求解简谐晶格声子传输系数的算法

曲靖师范学院学报 2024年第3期43卷 1-5页

作者：魏宇航贺达海厦门大学物理科学与技术学院福建厦门361005

根据朗之万格林函数理论,求简谐晶格中热流的关键在于求声子传输系数.传统上人们用基于分解三对角矩阵行列式的方法将求传输系数的过程转化为求转移矩阵的乘积从而降低时间复杂度,这种方法被称为转移矩阵法.但转移矩阵法的并行效果不佳... 详细信息

根据朗之万格林函数理论,求简谐晶格中热流的关键在于求声子传输系数.传统上人们用基于分解三对角矩阵行列式的方法将求传输系数的过程转化为求转移矩阵的乘积从而降低时间复杂度,这种方法被称为转移矩阵法.但转移矩阵法的并行效果不佳且不能用于存在长程相互作用的系统.提出了一种基于解线性方程组的高效算法来求解简谐系统中声子传输系数,提升了计算的并行效率,且使求解存在任意近邻耦合的声子传输系数的时间复杂度降为O(N),为相关领域的研究提供了算法上的帮助.

关键词：热传导朗之万格林函数理论传输系数高效算法

Polarization-sensitive and wide-spectrum photovoltaic detector based on quasi-1D ZrGeTe_(4)nanoribbon

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InfoMat 2022年第3期4卷 109-120页

作者： Ruixue Bai Tao Xiong Jinshu Zhou Yue-Yang Liu Wanfu Shen Chunguang Hu Faguang Yan Kaiyou Wang dahai wei Jingbo Li Juehan Yang Zhongming wei State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijingChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina College of Electronic Information and Optical Engineering Nankai UniversityTianjinChina State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjinChina Institute of Semiconductors South China Normal UniversityGuangzhouChina Guangdong Provincial Key Laboratory of Chip and Integration Technology GuangzhouChina

Low-dimensional semiconductors with in-plane anisotropy and narrow bandgap have been extensively applied to polarized detection in the near-infrared(NIR)region.However,the narrow bandgap can cause noise owing to the high dark current in photodetectors.This article reports quasi-1D ZrGeTe_(4)nanoribbonbased photodetectors with low dark current and broadband polarization detection.The photodetector was fabricated by evaporating 50-nm-thick Au electrodes on a ZrGeTe_(4)nanoribbon.Benefiting from the photovoltaic characteristics in the ZrGeTe_(4)nanoribbon and Au electrodes,these photodetectors can operate without bias voltage,with decreased dark current,and improved device performance.Furthermore,the quasi-1D ZrGeTe_(4)nanoribbon-based photodetectors demonstrate a polarization sensitivity in a broadband from visible(VIS)to the NIR region,such as a high photoresponsivity of 625.65 mA W1,large external quantum efficiency of 145.9%at 532 nm,and photocurrent anisotropy ratio of 2.04 at 1064 nm.They exhibit a novel perpendicular optical reversal of 90in polarization-sensitive photodetection,angle-resolved absorption spectra,and azimuth-dependent reflectance difference microscopy(ADRDM)from VIS to the NIR region,as opposed to other nanoribbon-based polarization-sensitive photodetectors.This work paves the way for utilizing photovoltaic photodetectors based on low-dimensional materials for broad-spectrum polarized photodetection.

关键词： linear polarization photodetector photovoltaic ZrGeTe_(4)nanoribbon

A crystal graph multilayer descriptor

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Journal of Semiconductors 2020年第8期41卷 2-2页

作者： dahai wei State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijingChina

2D ferromagnetic(FM)materials are crucial for next-generation spintronic devices owing to their atomic thickness and controllable electron/spin degree of freedom.However,due to the diversity of 2D structures and the complexity of magnetism,massive search for 2D FM materials is still a tough task.Recent development of machine learning technique has shown great potential in rapid searching for material with target property in large chemical space.Nevertheless,due to the lack of material data and proper descriptor,searching for 2D FM materials remains a challenge.

关键词： searching tough property

Artificial neuron and synapse in spintronics devices

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Journal of Semiconductors 2019年第5期40卷 6-6页

作者： dahai wei Institute of Semiconductors CAS

Neuromorphic computing is the development of computingschemes inspired by the processing of information in thebrain, which can execute complex tasks very efficiently usingan architecture that is completely different from that of semiconductorchips. Recently, researchers from Tohoku Universityhave realized an artificial neuron and synapse in spintronicsdevices, which are promising for future energy-efficientand adoptive computing systems, as they behave likethe spiking neural network in human brains.

关键词： Artificial neuron and synapse in spintronics devices

Tribological behavior comparisons of high chromium stainless and mild steels against high-speed steel and ceramics at high temperatures

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Friction 2022年第3期10卷 436-453页

作者： Shaogang CUI Yangzhen LIU Tong WANG Kiet TIEU Long WANG dahai ZENG Zhou LI wei LI Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou 510632China School of Mechanical MaterialsMechatronic and Biomedical EngineeringUniversity of WollongongNSW 2522Australia

High-temperature tribology,which is often involved during hot metal forming,is controlled via oxidation on a rubbing surface.However,for high chromium stainless steel(ST),where oxidation is strongly inhibited,the effect of counterface materials on tribological behavior is yet to be elucidated.In this study,the effects of counterfaces on the tribological behavior of 253MA ST and mild steel(MS)are investigated via a ball-on-disc test at 900°C using a 20 N load.The results reveal that high-speed steel(HSS)experiences severe abrasive wear with MS and causes severe sticking problems with ST.Si3N4 and SiC present substantially stronger abrasive wear resistance than HSS with MS,and the friction coefficients are dependent on the type of ceramic.Both ceramics can facilitate the establishment of a thick tribo-oxide layer(>3μm)on ST to prevent sticking;however,this is accompanied by severe pull-out and fracture wear.The effects of the counterface on the mechanical properties of the tribo-oxide layer,near-surface transformation,and the responses of the tribo-oxide layer to friction and wear are discussed.This study contributes to the understanding of interfacial tribological behaviors when different types of tools are used on MS and ST.

关键词： austenitic stainless steel(ST) counterface materials high-temperature tribology sticking problem tribo-oxide layer

IFN-γ表达与食管癌患者细胞免疫水平及预后的相关性分析

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现代肿瘤医学 2024年第4期32卷 659-663页

作者：黄腾黄维于大海马珺赵迪鹿红南京中医药大学附属医院江苏省中医院江苏南京210000

目的:探讨干扰素-γ(interferon gamma,IFN-γ)与食管癌患者细胞免疫水平及预后的相关性。方法:收集40例食管癌患者外周血标本,流式细胞仪检测标本中IFN-γ的浓度及CD4+T/CD8+T细胞比值;利用TISIDB数据库分析IFN-γ表达与免疫调控基因... 详细信息

目的:探讨干扰素-γ(interferon gamma,IFN-γ)与食管癌患者细胞免疫水平及预后的相关性。方法:收集40例食管癌患者外周血标本,流式细胞仪检测标本中IFN-γ的浓度及CD4+T/CD8+T细胞比值;利用TISIDB数据库分析IFN-γ表达与免疫调控基因的关系;收集119例食管癌患者临床预后信息,利用Kaplan-Meier生存曲线分析IFN-γ表达与食管癌患者生存预后的相关性。结果:外周血中IFN-γ的浓度和CD4+T/CD8+T细胞比值呈负相关(R2=0.1662,P=0.009);食管癌组织中IFN-γ表达与免疫负调控基因CD274(rho=0.449,P<0.001)和PDCD1(rho=0.778,P<0.001)的表达呈正相关;IFN-γ高表达于食管癌组织(P<0.001),且IFN-γ高表达组患者的总生存(overall survival,OS)显著低于IFN-γ低表达组(P=0.008)。结论:IFN-γ在食管癌组织中的表达与细胞免疫水平呈负相关,同时可作为食管癌患者预后不良的指标。

关键词：食管癌 IFN-γ 细胞免疫预后指标

Preface to the Special Issue on Challenges and Possibilities of Magnetic Semiconductors

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Journal of Semiconductors 2019年第8期40卷 8-8页

作者： Xinyu Liu dahai wei Jianhua Zhao University of Notre Dame Notre Dame 46556 USA Institute of Semiconductors Chinese Academy of Sciences Beijing100083 China

Magnetic semiconductors have been pursued for over 50 years because they combine two critical components of modern information technology: semiconductors for logic and magnets for memory. Remarkably, boosted by the discovery of ferromagnetism in the (III,Mn)As system two decades ago, magnetic semiconductors have become one of leading material systems which are critical for future applications in energy efficient information technology, quantum computing, and quantum communication. However, after more than a decade of rapid development, the ongoing research in magnetic semiconductors must now face reality:"Is it possible to create magnetic semiconductors that work at room temperature?" To answer this question, great efforts have recently been made in theory and experiments to discover and design new material platforms to host magnetic ions. These recent advances have thus revived our understanding of the field and lifted the field off for a new opportunity.

关键词： Special Issue Challenges Possibilities Magnetic Semiconductors

IL-1β表达与食管癌患者细胞免疫水平的相关性分析

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标记免疫分析与临床 2024年第6期31卷 1049-1053,1059页

作者：黄腾鹿红马珺赵迪黄维陈乐君于大海南京中医药大学附属医院江苏省中医院江苏南京210000

目的探讨IL-1β表达与食管癌患者细胞免疫水平的相关性。方法收集38例食管癌患者外周血标本,流式细胞仪检测血清中IL-1β的水平及CD4^(+)T/CD8^(+)T细胞比值;收集8例PD-1免疫治疗前后食管癌患者外周血标本,采用酶联免疫吸附法检测血清中... 详细信息

目的探讨IL-1β表达与食管癌患者细胞免疫水平的相关性。方法收集38例食管癌患者外周血标本,流式细胞仪检测血清中IL-1β的水平及CD4^(+)T/CD8^(+)T细胞比值;收集8例PD-1免疫治疗前后食管癌患者外周血标本,采用酶联免疫吸附法检测血清中IL-1β的水平;利用TIMER数据库分析IL-1β表达与免疫细胞浸润及关键调控基因的关系。结果外周血中IL-1β的水平和CD4^(+)T/CD8^(+)T细胞比值呈负相关(P=0.047);血清中IL-1β的水平在PD-1单抗免疫治疗后显著下降(P=0.038);食管癌组织中IL-1β的表达与巨噬细胞浸润呈负相关(P=0.00241),与中性粒细胞浸润呈正相关(P=0.00324);食管癌组织中IL-1β表达与B2M(P=0.0128)和PD-L1(P=0.00174)的表达呈正相关,与TNFRSF13C的表达呈负相关(P=0.0094)。结论IL-1β的表达与食管癌患者细胞免疫水平呈负相关,其机制与抑制免疫细胞浸润有关。

关键词： IL-1β 食管癌细胞免疫免疫细胞浸润