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Enhancing bifunctionality of CoN nanowires by Mn doping for long-lasting Zn-air batteries

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Science China Chemistry 2020年第7期63卷 890-896页

作者： Yongqi Zhang Bo Ouyang Guankui Long Hua Tan Zhe Wang Zheng Zhang weibo gao Rajdeep Singh Rawat Hong Jin Fan School of Physical and Mathematical Sciences Nanyang Technological University21 Nanyang Link637371Singapore Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 611731China Department of Applied Physics and Institution of Energy and Microstructure Nanjing University of Science and TechnologyNanjing 210094China Institute of Materials Research and Engineering A*STAR(Agency fo r ScienceTechnology and Research)Innovis 138634Singapore Natural Sciences and Science Education National Institute of EducationNanyang Technological UniversitySingapore 637616Singapore

Tailoring the nanostructure and composition of transition metal nitrides is highly important for their use as potent low-cost electrocatalysts. Cobalt nitride(CoN) exhibits strong catalytic activity for oxygen evolution reaction(OER). However, its poor catalytic efficiency for oxygen reduction reaction(ORR) hinders its application in rechargeable zinc-air batteries(ZABs) as the air cathode. In this work, we deploy the effective strategy of Mn doping to improve both OER and ORR activity of CoN nanowires as the cathode material for ZAB. Theoretical calculation predicts that moderate Mn doping in cobalt nitride results in a downshift of the d-band center and reduces the adsorption energy of reaction intermediates. With ~10 at% Mn dopants, stronger catalysis activities for both OER and ORR are achieved compared to pure CoN nanowires. Subsequently, both aqueous and flexible quasi-solid-state ZABs are constructed using the Mn-doped CoN nanowires array as additive-free air cathode. Both types of devices present large open circuit potential, high power density and long-cycle stability. This work pushes forward the progress in developing cost-effective ZABs.

关键词： bifunctional electrocatalyst Zn-air battery oxygen reduction reaction flexible battery plasma processing

Understanding and improving fairness in cognitive diagnosis

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Science China(Information Sciences) 2024年第5期67卷 99-114页

作者： Zheng ZHANG Le WU Qi LIU Jiayu LIU Zhenya HUANG Yu YIN Yan ZHUANG weibo gao Enhong CHEN Anhui Province Key Laboratory of Big Data Analysis and Application School of Computer Science and Technology& School of Data Science University of Science and Technology of China State Key Laboratory of Cognitive Intelligence School of Computer Science and Information Engineering Hefei University of Technology

Intelligent education is a significant application of artificial intelligence. One of the key research topics in intelligence education is cognitive diagnosis, which aims to gauge the level of proficiency among students on specific knowledge concepts(e.g., Geometry). To the best of our knowledge, most of the existing cognitive models primarily focus on improving diagnostic accuracy while rarely considering fairness issues; for instance, the diagnosis of students may be affected by various sensitive attributes(e.g., region). In this paper,we aim to explore fairness in cognitive diagnosis and answer two questions:(1) Are the results of existing cognitive diagnosis models affected by sensitive attributes?(2) If yes, how can we mitigate the impact of sensitive attributes to ensure fair diagnosis results? To this end, we first empirically reveal that several wellknown cognitive diagnosis methods usually lead to unfair performances, and the trend of unfairness varies among different cognitive diagnosis models. Then, we make a theoretical analysis to explain the reasons behind this phenomenon. To resolve the unfairness problem in existing cognitive diagnosis models, we propose a general fairness-aware cognitive diagnosis framework, FairCD. Our fundamental principle involves eliminating the effect of sensitive attributes on student proficiency. To achieve this, we divide student proficiency in existing cognitive diagnosis models into two components: bias proficiency and fair *** design two orthogonal tasks for each of them to ensure that fairness in proficiency remains independent of sensitive attributes and take it as the final diagnosed result. Extensive experiments on the Program for International Student Assessment(PISA) dataset clearly show the effectiveness of our framework.

关键词： fairness intelligent education cognitive diagnosis psychometrics adversarial learning

Quantum light sources from semiconductor

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Journal of Semiconductors 2019年第7期40卷 3-6页

作者： Disheng Chen weibo gao Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore The Photonics Institute and Centre for Disruptive Photonic Technologies Nanyang Technological University Singapore 637371 Singapore

Semiconductor provides a physics-rich environment to host various quantum light sources applicable for quantum information processing. These light sources are capable of deterministic generation of non-classical photon streams that demonstrate antibunching photon statistics, strong indistinguishability, and high-fidelity entanglement. Some of them have even successfully transitioned from proof-ofconcept to engineering efforts with steadily improving performance[ 1]. Here, we briefly summarize recent efforts and progress in the race towards ideal quantum light sources based on semiconductor materials. The focus of this report will be on group III–V semiconductor quantum dots, defects in wide band-gap materials, emitters in two-dimensional van der Waals layered hosts, and carbon nanotubes, as these systems are well-positioned to benefit from recent breakthroughs in nanofabrication and materials growth techniques.

关键词： Quantum light sources semiconductor

Room-temperature phonon-coupled single-photon emission in hexagonal boron nitride

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 109-114页

作者： Jia-Min Lai Qing-Hai Tan Feilong Song Haonan Chang Yanpei Lv Xue-Lu Liu Jinghua Teng weibo gao Ping-Heng Tan Jun Zhang State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing100083China Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education&Research Institute of Materials Science Shanxi Normal UniversityTaiyuan 030000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore Institute of Materials Research and Engineering(IMRE) Agency for ScienceTechnology and Research(A*STAR)Singapore 138634Singapore

Photon-lattice(phonon)coupling is fundamental to light-matter interaction,particularly when it reaches the quantum limit of the phonon-coupled single-photon emission,which holds great potential for quantum manipulation and quantum information ***,we report single defect state-phonon coupling in hexagonal boron nitride(h BN)at room *** ultrabroad spectrum of single-photon emissions can be achieved by selecting the excitation *** photoluminescence excitation spectroscopy,we observe single-phonon-assisted resonance-enhanced single-photon emission,along with multiple phonon replicas that herald the creation of phonon Fock *** also develop a transition model to gain insight into the physical process behind the single defect state-phonon *** work sets the stage for manipulating electron-phonon coupling state with single quantum-level precision at room temperature.

关键词： temperature phonon hexagonal

Phase-pure two-dimensional Fe_(X)GeTe_(2) magnets with near-room-temperature Tc

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Nano Research 2022年第1期15卷 457-464页

作者： Govindan Kutty Rajendran Nair Zhaowei Zhang Fuchen Hou§ Ali Abdelaziem Xiaodong Xu Steve Wu Qing Yang Nan Zhang Weiqi Li Chao Zhu Yao Wu Heng Weiling Lixing Kang Teddy Salim Jiadong Zhou Lin Ke Junhao Lin Xingji Li weibo gao Zheng Liu School of Material Science and Engineering 50 Nanyang Ave639798Singapore Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological University21 Nanyang Link637371 Singapore Department of Physics Southern University of Science and TechnologyShenzhen 518055China Institute of Materials Research and Engineering Agency for Science Technology and Research(A*STAR)2 Fusionopolis WaySingapore 138634Singapore School of Material Science and Engineering School of PhysicsHarbin Institute of TechnologyHarbin 150001China Shenzhen Key Laboratory of for Advanced Quantum Functional Materials and Devices Southern University of Science and TechnologyShenzhen 518055China National Institute of Laser Enhanced Sciences(NILES) Cairo UniversityGiza 12613Egypt CINTRA CNRS/NTU/THALES UMI3288Research Techno Plaza637553Singapore School of Electrical and Electronic Engineering Nanyang Technological University50 Nanyang Ave639798Singapore

Two-dimensional(2D)ferromagnets with out-of-plane(OOP)magnetic anisotropy are potential candidates for realizing the next-generation memory devices with ultra-low power consumption and high storage ***,a scalable approach to synthesize 2D magnets with OOP anisotropy directly on the complimentary metal-oxide semiconductor(CMOS)compatible substrates has not yet been mainly explored,which hinders the practical application of 2D *** work demonstrates a cascaded space confined chemical vapor deposition(CS-CVD)technique to synthesize 2D FexGeTe_(2) *** weight fraction of iron(Fe)in the precursor controls the phase purity of the as-grown *** a result,high-quality Fe_(3)GeTe_(2) and Fe_(5)GeTe_(2) flakes have been grown selectively using the CS-CVD *** temperature(Tc)of the as-grown FexGeTe2 can be up to-280 K,nearly room *** thickness and temperature-dependent magnetic studies on the Fe_(5)GeTe_(2) reveal a 2D Ising to 3D XY ***,Terahertz spectroscopy experiments on Fe_(5)GeTe_(2) display the highest conductivity among other FexGeTe_(2) 2D *** results of this work indicate a scalable pathway for the direct growth and integration of 2D ternary magnets on CMOS-based substrates to develop spintronic memory devices.

关键词： cascaded space confined chemical vapor deposition(CVD) van der Waals(vdW) ferromagnetism out of plane anisotropy iron germanium telluride terahertz

中性粒细胞/淋巴细胞比率联合血小板/淋巴细胞比率检测对于重症急性胰腺炎早期预测价值

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中华急诊医学杂志 2021年第8期30卷 948-953页

作者：宋小静高伟波朱继红北京大学人民医院急诊科 100044

目的评估中性粒细胞/淋巴细胞比率(Neutrophil to lymphocyte ratio,NLR)联合血小板/淋巴细胞比率(platelet to lymphocyteratio,PLR)检测(NLR-PLR)对于重症急性胰腺炎(severe acute pancreatitis,SAP)早期预测价值。方法连续性收集2019年1月至2019年12月北京大学人民医院急诊科符合急性胰腺炎(acute pancreatitis,AP)诊断标准的216例患者。按病情严重程度分为轻症急性胰腺炎组(mild acute pancreatitis,MAP)(86例)、中度重症急性胰腺炎组(moderately severe acute pancreatitis,MSAP)(40例)及SAP组(90例)三组。所有患者均于发病48 h内采集外周血样进行分析,检测白细胞计数(WBC)、中性粒细胞计数(NEUT)、淋巴细胞计数(LYM)、血红蛋白(HGB)、血小板计数(PLT)、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)、血清肌酐(CR)、血糖(GLU)等实验室指标,同时完善CT影像学等检查,分别计算NLR和PLR,比较NLR和PLR在三组中是否具有统计学意义。比较NLR、PLR和APACHEⅡ评分及Ranson评分的相关性。同时绘制受试者工作特征曲线(R0C曲线)计算NLR和PLR的最佳阈值,分别依据NLR和PLR的最佳阈值,计算NLR-PLR,同时绘制ROC曲线研究NLR-PLR对于SAP的预测价值。结果NLR[OR=1.071,95%CI(1.025,1.120),P=0.002]和PLR[OR=1.003,95%CI(1.000,1.244),P=0.044]是早期重症胰腺炎的危险因素。NLR与Ranson评分呈正相关(r=0.0342,P<0.05);NLR与APACHEⅡ评分呈正相关(r=0.0210,P=0.003);PLR与Ranson评分呈正相关(r=0.0218,P=0.002);PLR与APACHEⅡ评分呈无相关性(P=0.157)。NLR和PLR的ROC曲线下面积(AUC)分别为0.894和0.728。NLR的最佳阈值为6.105,敏感度为92.9%,特异度为76.1%,PLR的最佳阈值为154.358,敏感度为78.2%,特异度为73.2%。依据最佳阈值,计算NLR-PLR(NLR≥6.105且PLR≥154.358),比较NLR-PLR、NLR(≥6.105)和PLR(≥154.358)的ROC曲线下面积,其中NLR-PLR曲线下面积最大,为0.864。结论NLR和PLR在AP发病48 h内对SAP患者病情的具有预测价值,NLR-PLR联合检测对于SAP具有早期预测价值。

关键词：中性粒细胞/淋巴细胞比率血小板/淋巴细胞比率重症急性胰腺炎

中性粒细胞和淋巴细胞比率与溶栓后急性脑卒中预后的关系

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中华急诊医学杂志 2020年第7期29卷 976-980页

作者：吕苏高伟波朱继红北京大学人民医院急诊科 100044

目的探讨中性粒细胞与淋巴细胞比率(neutrophil and lymphocyte ratio,NLR)与急性缺血性脑卒中的严重程度以及患者接受静脉溶栓治疗后临床预后的关系。方法回顾性研究2016年1月至2019年1月北京大学人民医院急诊科及重症监护室符合急性... 详细信息

目的探讨中性粒细胞与淋巴细胞比率(neutrophil and lymphocyte ratio,NLR)与急性缺血性脑卒中的严重程度以及患者接受静脉溶栓治疗后临床预后的关系。方法回顾性研究2016年1月至2019年1月北京大学人民医院急诊科及重症监护室符合急性缺血性脑卒中(acute ischemic stroke,AIS)诊断标准的147例静脉溶栓患者,根据NLR值,将147例患者分为NLR≤2组(37例),2

关键词：中性粒细胞与淋巴细胞比率急性缺血脑卒中溶栓严重程度预后

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钕铁硼磁钢居里温度的测定

中国稀土学报 2020年第4期38卷 460-466,I0001页

作者：高伟波王顺杰孙梦翔张俊良宁波市计量测试研究院浙江宁波315048 宁波大学信息科学与工程学院浙江宁波315211

居里温度是影响钕铁硼磁钢应用的重要因素和反映磁性材料温度稳定性的基本参数。对于居里温度的测量,多数方法局限在小尺寸的样品测量,但在工程应用中,往往关注的是磁钢的整体特性,而小尺寸样品的测量不能很好反映磁钢的整体特性。通过... 详细信息

居里温度是影响钕铁硼磁钢应用的重要因素和反映磁性材料温度稳定性的基本参数。对于居里温度的测量,多数方法局限在小尺寸的样品测量,但在工程应用中,往往关注的是磁钢的整体特性,而小尺寸样品的测量不能很好反映磁钢的整体特性。通过钕铁硼磁钢的热膨胀实验发现:热膨胀系数α的最小值所对应的温度点不会因磁钢的取向改变而改变,此温度点就是钕铁硼磁钢的居里温度。由于不受几何尺寸与取向的限制,此方法能更好地反映钕铁硼磁钢整体的居里温度。同时还对比了M-T曲线测试法、差热(DSC)或热重(TG)分析测试法、ARROTT图测试法,研究进一步证实了热膨胀测试居里温度具有很高的准确性;通过材料测试与分析进一步证明了所测居里温度的合理性。

关键词：钕铁硼磁钢居里温度热膨胀系数准确性

中性粒/淋巴细胞比率、血小板/淋巴细胞比率联合BISAP评分对于重症高三酰甘油血症性胰腺炎早期预测分析

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中华急诊医学杂志 2022年第9期31卷 1193-1199页

作者：宋小静高伟波朱继红北京大学人民医院急诊科北京100044

目的研究中性粒/淋巴细胞比率(neutrophil to lymphocyte ratio,NLR)、血小板/淋巴细胞比率(platelet to lymphocyte ratio,PLR)联合急性胰腺炎床旁严重度指数(bedsideindex for severity in acute pancreatitis,BISAP)评分对于重症高三酰甘油血症性胰腺炎(hypertriglyceridemia pancreatitis,HTGP)患者的早期预测价值。方法回顾性收集2019年1月至2019年12月北京大学人民医院急诊科符合HTGP诊断标准的患者。按病情严重程度分为轻症急性胰腺炎和重症急性胰腺炎(severeacute pancreatitis,SAP)两组。所有患者均于发病24h内采集血样,检测白细胞计数、中性粒细胞计数、淋巴细胞计数等实验室指标,均在HTGP发病24h内进行BISAP评分。比较两组中各种指标,通过Logistic回归分析HTGP中SAP患者的危险因素,利用相关性分析各危险因素的相关性。同时绘制受试者工作特征(ROC)曲线,分别计算NLR和PLR的最佳阈值,比较BISAP评分、NLR联合BISAP评分(BN评分)、PLR联合BISAP评分(BP评分)和NLR、PLR联合BISAP评分(BNP评分)对HTGP中SAP患者的预测价值。结果共纳入82例患者,两组中发热患者比例、NLR、PLR、乳酸脱氢酶、尿素氮、Ranson评分、急性生理学与慢性健康状况(acute physiology and chronic health evaluation,APACHE)Ⅱ评分及BISAP评分具有统计学差异(P<0.05)。通过Logistic回归分析,NLR(OR=1.859,95%CI:1.385~2.497,P<0.001),PLR(OR=1.074,95%CI:1.036~1.112,P<0.001)和BISAP评分(OR=2.880,95%CI:1.578~5.258,P=0.001)是HTGP中重症患者的危险因素。相关性分析证实NLR、PLR均与BISAP评分、APACHEⅡ评分及Ranson评分呈正相关性。通过绘制ROC曲线,计算BISAP评分、BN评分、BP评分及BNP评分预测HTGP中SAP的AUC分别为0.865(95%CI:0.787~0.943)0.925(95%CI:0.869~0.981).0.930(95%CI:0.885~0.987)及0.936(95%CI:0.874~0.986)。结论NLR和PLR联合BISAP评分预测HTGP中SAP患者的敏感度更高,可以HTGP发病24h内对SAP做出预测,更好的指导治疗,改善预后。

关键词：中性粒细胞/淋巴细胞比率血小板/淋巴细胞比率高三酰甘油性胰腺炎重症胰腺炎急性胰腺炎床旁严重度指数评分