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基于瞬态平面热源法测定SiO_2气凝胶导热系数的试验
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作者 戴健彪 桂晓丽 《科技视界》 2024年第3期63-65,共3页
阐述基于瞬态平面热源法的Hot Disk热常数分析仪的测试原理,利用测试标准304不锈钢对仪器准确性及重复性进行了验证,同时研究了不同孔隙率SiO_2气凝胶的导热系数随温度和压力变化的特点。结果表明:Hot Disk热常数分析仪在测试SiO_2气凝... 阐述基于瞬态平面热源法的Hot Disk热常数分析仪的测试原理,利用测试标准304不锈钢对仪器准确性及重复性进行了验证,同时研究了不同孔隙率SiO_2气凝胶的导热系数随温度和压力变化的特点。结果表明:Hot Disk热常数分析仪在测试SiO_2气凝胶导热系数方面具有优异的准确性和重复性;在相同的温度和压力下,SiO_2气凝胶的导热系数随着孔隙率增大而变小;当环境压力小于5×10~3 Pa时,导热系数随环境压力改变而变化不明显,当环境压力大于5×10~3 Pa,导热系数随环境压力升高而变化较大;当环境温度在100~500℃范围内,SiO_2气凝胶的导热系数随环境温度升高而略微变大,当环境温度继续升高时,导热系数随环境温度升高而迅速增大。 展开更多
关键词 瞬态平面热源法 孔隙率 SiO_2气凝胶 导热系数
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The initial stages of Li_(2)O_(2) formation during oxygen reduction reaction in Li-O_(2) batteries:The significance of Li_(2)O_(2) in charge-transfer reactions within devices 被引量:1
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作者 Daniela M.Josepetti Bianca P.Sousa +2 位作者 Simone A.J.Rodrigues Renato G.Freitas Gustavo Doubek 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期223-231,I0006,共10页
Lithium-oxygen batteries are a promising technology because they can greatly surpass the energy density of lithium-ion batteries.However,this theoretical characteristic has not yet been converted into a real device wi... Lithium-oxygen batteries are a promising technology because they can greatly surpass the energy density of lithium-ion batteries.However,this theoretical characteristic has not yet been converted into a real device with high cyclability.Problems with air contamination,metallic lithium reactivity,and complex discharge and charge reactions are the main issues for this technology.A fast and reversible oxygen reduction reaction(ORR)is crucial for good performance of secondary batteries',but the partial knowledge of its mechanisms,especially when devices are concerned,hinders further development.From this perspective,the present work uses operando Raman experiments and electrochemical impedance spectroscopy(EIS)to assess the first stages of the discharge processes in porous carbon electrodes,following their changes cycle by cycle at initial operation.A growth kinetic formation of the discharge product signal(Li_(2)O_(2))was observed with operando Raman,indicating a first-order reaction and enabling an analysis by a microkinetic model.The solution mechanism in the evaluated system was ascribed for an equivalent circuit with three time constants.While the time constant for the anode interface reveals to remain relatively constant after the first discharge,its surface seemed to be more non-uniform.The model indicated that the reaction occurs at the Li_(2)O_(2) surface,decreasing the associated resistance during the initial discharge phase.Furthermore,the growth of Li_(2)O_(2) forms a hetero-phase between Li_(2)O_(2)/electrolyte,while creating a more compact and homogeneous on the Li_(2)O_(2)/cathode surface.The methodology here described thus offers a way of directly probing changes in surface chemistry evolution during cycling from a device through EIS analysis. 展开更多
关键词 Li-O_(2)battery Operando Raman analysis Equivalent circuit modeling Time-constant distribution
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Magnetic domain structures in ultrathin Bi_(2)Te_(3)/CrTe_(2) heterostructures
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作者 夏体瑞 杨笑天 +6 位作者 张逸凡 刘馨琪 蔡新雨 刘畅 姚岐 寇煦丰 王文波 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期511-517,共7页
Chromium tellurium compounds are important two-dimensional van der Waals ferromagnetic materials with high Curie temperature and chemical stability in air,which is promising for applications in spintronic devices.Here... Chromium tellurium compounds are important two-dimensional van der Waals ferromagnetic materials with high Curie temperature and chemical stability in air,which is promising for applications in spintronic devices.Here,highquality spin-orbital-torque(SOT)device,Bi_(2)Te_(3)/CrTe_(2)heterostructure was epitaxially grown on Al_(2)O_(3)(0001)substrates.Anomalous Hall measurements indicate the existence of strong ferromagnetism in this device with the CrTe_(2)thickness down to 10 nm.In order to investigate its micromagnetic structure,cryogenic magnetic force microscope(MFM)was utilized to measure the magnetic domain evolutions at various temperatures and magnetic fields.The virgin domain state of the device shows a worm-like magnetic domain structure with the size around 0.6μm-0.8μm.Larger irregular-shape magnetic domains(>1μm)can be induced and pinned,after the field is increased to coercive field and ramped back to low fields.The temperature-dependent MFM signals exhibit a nice mean-field-like ferromagnetic transition with Curie temperature around 201.5 K,indicating a robust ferromagnetic ordering.Such a device can be potentially implemented in future magnetic memory technology. 展开更多
关键词 CrTe_(2) magnetic domain magnetic force microscopy
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Microstructural, wettability, and corrosion behaviour of TiO_(2) thin film sputtered on aluminium
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作者 Rajeev VERMA Vijay KUMAR +2 位作者 Saurabh KANGO Amindra KHILLA Rajeev GUPTA 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2210-2224,共15页
The study investigated the application of radiofrequency(RF)-sputtered TiO2 coatings at various temperatures to enhance the hydrophobicity and corrosion resistance of Al6061 alloy.The research aimed to establish a cor... The study investigated the application of radiofrequency(RF)-sputtered TiO2 coatings at various temperatures to enhance the hydrophobicity and corrosion resistance of Al6061 alloy.The research aimed to establish a correlation between the coating process and the resulting surface properties.Surface roughness and wettability were quantified with a surface profilometer and goniometer.Additionally,chemical boiling and salt spray corrosion tests were conducted to evaluate any topographical changes during these procedures.The analysis further involved the use of field-emission scanning electron microscopy(FESEM),energy-dispersive spectroscopy(EDS),and X-ray diffraction(XRD)techniques to characterize the deposited coatings.The findings indicated that the TiO2 coating applied at 500℃exhibited the highest water contact angle and superior corrosion resistance compared to other temperatures.Surface characterization confirmed that this specific TiO_(2) coating at 500℃ effectively delays corrosion due to its hydrophobic behavior,making it durable for industrial applications. 展开更多
关键词 aluminium TiO_(2)coating radiofrequency-sputtering HYDROPHOBIC corrosion
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Light-emitting devices based on atomically thin MoSe_(2)
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作者 Xinyu Zhang Xuewen Zhang +7 位作者 Hanwei Hu Vanessa Li Zhang Weidong Xiao Guangchao Shi Jingyuan Qiao Nan Huang Ting Yu Jingzhi Shang 《Journal of Semiconductors》 EI CAS CSCD 2024年第4期19-35,共17页
Atomically thin MoSe_(2) layers,as a core member of the transition metal dichalcogenides(TMDs)family,benefit from their appealing properties,including tunable band gaps,high exciton binding energies,and giant oscillat... Atomically thin MoSe_(2) layers,as a core member of the transition metal dichalcogenides(TMDs)family,benefit from their appealing properties,including tunable band gaps,high exciton binding energies,and giant oscillator strengths,thus pro-viding an intriguing platform for optoelectronic applications of light-emitting diodes(LEDs),field-effect transistors(FETs),sin-gle-photon emitters(SPEs),and coherent light sources(CLSs).Moreover,these MoSe_(2) layers can realize strong excitonic emis-sion in the near-infrared wavelengths,which can be combined with the silicon-based integration technologies and further encourage the development of the new generation technologies of on-chip optical interconnection,quantum computing,and quantum information processing.Herein,we overview the state-of-the-art applications of light-emitting devices based on two-dimensional MoSe_(2) layers.Firstly,we introduce recent developments in excitonic emission features from atomically thin MoSe_(2) and their dependences on typical physical fields.Next,we focus on the exciton-polaritons and plasmon-exciton polaritons in MoSe_(2) coupled to the diverse forms of optical microcavities.Then,we highlight the promising applications of LEDs,SPEs,and CLSs based on MoSe_(2) and their heterostructures.Finally,we summarize the challenges and opportunities for high-quality emis-sion of MoSe_(2) and high-performance light-emitting devices. 展开更多
关键词 MoSe_(2) light-matter interaction EXCITON POLARITON light-emitting device
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Interworking between Modbus and internet of things platform for industrial services
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作者 Sherzod Elamanov Hyeonseo Son +3 位作者 Bob Flynn Seong Ki Yoo Naqqash Dilshad JaeSeung Song 《Digital Communications and Networks》 SCIE CSCD 2024年第2期461-471,共11页
In the era of rapid development of Internet of Things(IoT),numerous machine-to-machine technologies have been applied to the industrial domain.Due to the divergence of IoT solutions,the industry is faced with a need t... In the era of rapid development of Internet of Things(IoT),numerous machine-to-machine technologies have been applied to the industrial domain.Due to the divergence of IoT solutions,the industry is faced with a need to apply various technologies for automation and control.This fact leads to a demand for an establishing interworking mechanism which would allow smooth interoperability between heterogeneous devices.One of the major protocols widely used today in industrial electronic devices is Modbus.However,data generated by Modbus devices cannot be understood by IoT applications using different protocols,so it should be applied in a couple with an IoT service layer platform.oneM2M,a global IoT standard,can play the role of interconnecting various protocols,as it provides flexible tools suitable for building an interworking framework for industrial services.Therefore,in this paper,we propose an interworking architecture between devices working on the Modbus protocol and an IoT platform implemented based on oneM2M standards.In the proposed architecture,we introduce the way to model Modbus data as oneM2M resources,rules to map them to each other,procedures required to establish interoperable communication,and optimization methods for this architecture.We analyze our solution and provide an evaluation by implementing it based on a solar power management use case.The results demonstrate that our model is feasible and can be applied to real case scenarios. 展开更多
关键词 Internet of things INTEROPERABILITY INTERWORKING MODBUS oneM2M
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Numerical Analysis on the Effect of n-Si on Cu(In, Ga)Se2 Based Thin-Films for High-Performance Solar Cells by 1D-SCAPS
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作者 Rasika N. Mohottige Micheal Farndale +1 位作者 Gary S. Coombs Shahnoza Saburhhojayeva 《Open Journal of Applied Sciences》 2024年第5期1315-1329,共15页
We report the performances of a chalcopyrite Cu(In, Ga)Se<sub>2 </sub>CIGS-based thin-film solar cell with a newly employed high conductive n-Si layer. The data analysis was performed with the help of the ... We report the performances of a chalcopyrite Cu(In, Ga)Se<sub>2 </sub>CIGS-based thin-film solar cell with a newly employed high conductive n-Si layer. The data analysis was performed with the help of the 1D-Solar Cell Capacitance Simulator (1D-SCAPS) software program. The new device structure is based on the CIGS layer as the absorber layer, n-Si as the high conductive layer, i-In<sub>2</sub>S<sub>3</sub>, and i-ZnO as the buffer and window layers, respectively. The optimum CIGS bandgap was determined first and used to simulate and analyze the cell performance throughout the experiment. This analysis revealed that the absorber layer’s optimum bandgap value has to be 1.4 eV to achieve maximum efficiency of 22.57%. Subsequently, output solar cell parameters were analyzed as a function of CIGS layer thickness, defect density, and the operating temperature with an optimized n-Si layer. The newly modeled device has a p-CIGS/n-Si/In<sub>2</sub>S<sub>3</sub>/Al-ZnO structure. The main objective was to improve the overall cell performance while optimizing the thickness of absorber layers, defect density, bandgap, and operating temperature with the newly employed optimized n-Si layer. The increase of absorber layer thickness from 0.2 - 2 µm showed an upward trend in the cell’s performance, while the increase of defect density and operating temperature showed a downward trend in solar cell performance. This study illustrates that the proposed cell structure shows higher cell performances and can be fabricated on the lab-scale and industrial levels. 展开更多
关键词 n-Si p-CIGS 1D-SCAPS thin-Films In2S3
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Engineering of oxygen vacancy and bismuth cluster assisted ultrathin Bi_(12)O_(17)Cl_(2)nanosheets with efficient and selective photoreduction of CO_(2)to CO
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作者 Meili Guan Ni Lu +7 位作者 Xuan Zhang Qiuwan Wang Jian Bao Guiye Chen Hao Yu Huaming Li Jiexiang Xia Xuezhong Gong 《Carbon Energy》 SCIE EI CAS CSCD 2024年第4期1-11,共11页
The photocatalytic conversion of CO_(2)into solar‐powered fuels is viewed as a forward‐looking strategy to address energy scarcity and global warming.This work demonstrated the selective photoreduction of CO_(2)to C... The photocatalytic conversion of CO_(2)into solar‐powered fuels is viewed as a forward‐looking strategy to address energy scarcity and global warming.This work demonstrated the selective photoreduction of CO_(2)to CO using ultrathin Bi_(12)O_(17)Cl_(2)nanosheets decorated with hydrothermally synthesized bismuth clusters and oxygen vacancies(OVs).The characterizations revealed that the coexistences of OVs and Bi clusters generated in situ contributed to the high efficiency of CO_(2)–CO conversion(64.3μmol g^(−1)h^(−1))and perfect selectivity.The OVs on the facet(001)of the ultrathin Bi_(12)O_(17)Cl_(2)nanosheets serve as sites for CO_(2)adsorption and activation sites,capturing photoexcited electrons and prolonging light absorption due to defect states.In addition,the Bi‐cluster generated in situ offers the ability to trap holes and the surface plasmonic resonance effect.This study offers great potential for the construction of semiconductor hybrids as multiphotocatalysts,capable of being used for the elimination and conversion of CO_(2)in terms of energy and environment. 展开更多
关键词 Bi cluster Bi_(12)O_(17)Cl_(2)nanosheet oxygen vacancy photocatalytic CO_(2)reduction
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Ultrathin GaN Film Derived from Amorphous Ga_(2)O_(3) Film
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作者 王鹏 ZHANG Binbin +4 位作者 LIU Xiaofei ZHANG Xin TU Rong ZHANG Song 李宝文 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第4期814-818,共5页
It remains a big challenge to synthesize two-dimensional(2D)GaN material for applications in power nanodevices.Traditional synthetic methods require complex equipment and processes and time consuming.Here,we reported ... It remains a big challenge to synthesize two-dimensional(2D)GaN material for applications in power nanodevices.Traditional synthetic methods require complex equipment and processes and time consuming.Here,we reported a two-step route to prepare polycrystalline 2D GaN film.The amorphous ultrathin Ga_(2)O_(3)film was first exfoliated from the surface of liquid gallium.In a vapor phase reaction,2D Ga_(2)O_(3)film was then converted into 2D GaN film while maintaining the 2D morphology.Raman and high-resolution transmission electron microscope(HRTEM)analysis implies the successful synthesis of wurtzite-type GaN ultrathin film.This simple strategy proposed in this work will provide more opportunities for applications of GaN ultrathin film in many devices. 展开更多
关键词 GaN Ga_(2)O_(3) liquid gallium
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Regulation of interlayer channels of graphene oxide nanosheets in ultra-thin Pebax mixed-matrix membranes for CO_(2) capture
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作者 Feifan Yang Yuanhang Jin +5 位作者 Jiangying Liu Haipeng Zhu Rong Xu Fenjuan Xiangli Gongping Liu Wanqin Jin 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期257-267,共11页
For the application of carbon capture by membrane process,it is crucial to develop a highly permeable CO_(2)-selective membrane.In this work,we reported an ultra-thin polyether-block-amide(Pebax)mixedmatrix membranes(... For the application of carbon capture by membrane process,it is crucial to develop a highly permeable CO_(2)-selective membrane.In this work,we reported an ultra-thin polyether-block-amide(Pebax)mixedmatrix membranes(MMMs)incorporated by graphene oxide(GO),in which the interlayer channels were regulated to optimize the CO_(2)/N_(2) separation performance.Various membrane preparation conditions were systematically investigated on the influence of the membrane structure and separation performance,including the lateral size of GO nanosheets,GO loading,thermal reduction temperature,and time.The results demonstrated that the precisely regulated interlayer channel of GO nanosheets can rapidly provide CO_(2)-selective transport channels due to the synergetic effects of size sieving and preferential adsorption.The GO/Pebax ultra-thin MMMs exhibited CO_(2)/N_(2) selectivity of 72 and CO_(2) permeance of 400 GPU(1 GPU=106 cm^(3)(STP)·cm^(2)·s^(-1)·cmHg^(-1)),providing a promising candidate for CO_(2) capture. 展开更多
关键词 Mixed-matrix membrane Ultra-thin membrane Pebax Graphene oxide CO_(2) capture
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Observing ferroelastic switching in Hf_(0.5)Zr_(0.5)O_(2) thin film
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作者 关赵 王陶 +11 位作者 郑赟喆 彭悦 魏鹿奇 张宇科 阿卜力孜·麦提图尔荪 黄家豪 童文旖 韩根全 陈斌斌 向平华 段纯刚 钟妮 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期526-530,共5页
Hafnium zirconium oxides(HZO),which exhibit ferroelectric properties,are promising materials for nanoscale device fabrication due to their high complementary metal-oxide-semiconductor(CMOS) compatibility.In addition t... Hafnium zirconium oxides(HZO),which exhibit ferroelectric properties,are promising materials for nanoscale device fabrication due to their high complementary metal-oxide-semiconductor(CMOS) compatibility.In addition to piezoelectricity,ferroelectricity,and flexoelectricity,this study reports the observation of ferroelasticity using piezoelectric force microscopy(PFM) and scanning transmission electron microscopy(STEM).The dynamics of 90° ferroelastic domains in HZO thin films are investigated under the influence of an electric field.Switching of the retentive domains is observed through repeated wake-up measurements.This study presents a possibility of enhancing polarization in HZO thin films during wake-up processes. 展开更多
关键词 HfO_(2)-based ferroelectrics FERROELASTICITY piezoelectric force microscopy(PFM)
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Multi-Elemental Analysis and 2D Image Mapping within Roots, Leaves and Seeds from O. glaberrima Rice Plants Using Micro-PIXE Technique
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作者 Alassane Traore Anna Ndiaye +6 位作者 Christopher Bongani Mtshali Manneh Baboucarr Jean Paul Latyr Faye Daouda Mbodj Kandiaba Traore Tapha Gueye Ababacar Sadikhe Ndao 《World Journal of Nuclear Science and Technology》 CAS 2024年第2期97-106,共10页
Understanding metal accumulation at organ level in roots, leaves and seeds in O. glaberrima (OG) is crucial for improving physiological and metabolic aspects in growing Asian and African rice in salted areas. The micr... Understanding metal accumulation at organ level in roots, leaves and seeds in O. glaberrima (OG) is crucial for improving physiological and metabolic aspects in growing Asian and African rice in salted areas. The micro-analytical imaging techniques are required to reveal its accumulation and distribution within plant tissues. PIXE studies have been performed to determine different elements in rice plants. The existing microbeam analytical technique at the iThemba LABS will be applied for the 2D image mapping of fresh rice tissues to perform a concentration of low atomic mass elements (such as Al, Si, P, S, Cl, Ca, Ti, Mn, Fe, Cu, Br, Zn and K) with detection limits of typically 1-10 μg/g. Comparison of the distribution of the elements between leaves, root and seed samples using uptake and distribution of elements in particular environmental conditions with potential amount of salt in water have been performed. We are also expecting to indicate metal exclusion as salt tolerance strategies from leaves, root, and seed compartments using matrix correlation between samples and between elements on rice species. 展开更多
关键词 PIXE 2D Mapping Rice Concentration Elemental Analysis
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An Efficient and Provably Secure SM2 Key-Insulated Signature Scheme for Industrial Internet of Things
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作者 Senshan Ouyang Xiang Liu +3 位作者 Lei Liu Shangchao Wang Baichuan Shao Yang Zhao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期903-915,共13页
With the continuous expansion of the Industrial Internet of Things(IIoT),more andmore organisations are placing large amounts of data in the cloud to reduce overheads.However,the channel between cloud servers and smar... With the continuous expansion of the Industrial Internet of Things(IIoT),more andmore organisations are placing large amounts of data in the cloud to reduce overheads.However,the channel between cloud servers and smart equipment is not trustworthy,so the issue of data authenticity needs to be addressed.The SM2 digital signature algorithm can provide an authentication mechanism for data to solve such problems.Unfortunately,it still suffers from the problem of key exposure.In order to address this concern,this study first introduces a key-insulated scheme,SM2-KI-SIGN,based on the SM2 algorithm.This scheme boasts strong key insulation and secure keyupdates.Our scheme uses the elliptic curve algorithm,which is not only more efficient but also more suitable for IIoT-cloud environments.Finally,the security proof of SM2-KI-SIGN is given under the Elliptic Curve Discrete Logarithm(ECDL)assumption in the random oracle. 展开更多
关键词 KEY-INSULATED SM2 algorithm digital signature Industrial Internet of things(IIoT) provable security
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Effect of Lewis acid-base additive on lead-free Cs_(2)SnI_(6) thin film prepared by direct solution coating process
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作者 Saqib Nawaz Khan 王燕 +3 位作者 钟李祥 梁会力 杜小龙 梅增霞 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期444-451,共8页
Inorganic Cs_(2)SnI_(6) perovskite has exhibited substantial potential for light harvesting due to its exceptional optoelectronic properties and remarkable stability in ambient conditions.The charge transport characte... Inorganic Cs_(2)SnI_(6) perovskite has exhibited substantial potential for light harvesting due to its exceptional optoelectronic properties and remarkable stability in ambient conditions.The charge transport characteristics within perovskite films are subject to modulation by various factors,including crystalline orientation,morphology,and crystalline quality.Achieving preferred crystalline orientation and film morphology via a solution-based process is challenging for Cs_(2)SnI_(6) films.In this work,we employed thiourea as an additive to optimize crystal orientation,enhance film morphology,promote crystallization,and achieve phase purity.Thiourea lowers the surface energy of the(222)plane along the(111)direction,confirmed by x-ray diffraction,x-ray photoelectron spectroscopy,ultraviolet photoelectron spectroscopy studies,and density functional theory calculations.Varying thiourea concentration enables a bandgap tuning of Cs_(2)SnI_(6) from 1.52 eV to1.07 eV.This approach provides a novel method for utilizing Cs_(2)SnI_(6) films in high-performance optoelectronic devices. 展开更多
关键词 Cs_(2)SnI_(6) crystalline orientation Lewis acid-case additive engineering bandgap engineering
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Interface optimization and defects suppression via Na F introduction enable efficient flexible Sb_(2)Se_(3) thin-film solar cells
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作者 Mingdong Chen Muhammad Ishaq +7 位作者 Donglou Ren Hongli Ma Zhenghua Su Ping Fan David Le Coq Xianghua Zhang Guangxing Liang Shuo Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期165-175,I0006,共12页
Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of f... Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of flexible Sb_(2)Se_(3) photovoltaic devices is temporarily limited by the complicated intrinsic defects and the undesirable contact interfaces.Herein,a high-quality Sb_(2)Se_(3) absorber layer with large crystal grains and benign [hkl] growth orientation can be first prepared on a Mo foil substrate.Then NaF intermediate layer is introduced between Mo and Sb_(2)Se_(3),which can further optimize the growth of Sb_(2)Se_(3)thin film.Moreover,positive Na ion diffusion enables it to dramatically lower barrier height at the back contact interface and passivate harmful defects at both bulk and heterojunction.As a result,the champion substrate structured Mo-foil/Mo/NaF/Sb_(2)Se_(3)/CdS/ITO/Ag flexible thin-film solar cell delivers an obviously higher efficiency of 8.03% and a record open-circuit voltage(V_(OC)) of 0.492 V.This flexible Sb_(2)Se_(3) device also exhibits excellent stability and flexibility to stand large bending radius and multiple bending times,as well as superior weak light photo-response with derived efficiency of 12.60%.This work presents an effective strategy to enhance the flexible Sb_(2)Se_(3) device performance and expand its potential photovoltaic applications. 展开更多
关键词 Sb_(2)Se_(3) Flexible solar cells NaF intermediate layer Interface optimization Defects suppression
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A Novel Approach for Developing a Linear Regression Model within Logistic Cluster Using Scikit-Learn
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作者 Nwosu Ambrose Gilbert I. O. Aimufua Choji Davou Nyap 《Journal of Data Analysis and Information Processing》 2024年第3期348-369,共22页
Due to the rapid development of logistic industry, transportation cost is also increasing, and finding trends in transportation activities will impact positively in investment in transportation infrastructure. There i... Due to the rapid development of logistic industry, transportation cost is also increasing, and finding trends in transportation activities will impact positively in investment in transportation infrastructure. There is limited literature and data-driven analysis about trends in transportation mode. This thesis delves into the operational challenges of vehicle performance management within logistics clusters, a critical aspect of efficient supply chain operations. It aims to address the issues faced by logistics organizations in optimizing their vehicle fleets’ performance, essential for seamless logistics operations. The study’s core design involves the development of a predictive logistics model based on regression, focused on forecasting, and evaluating vehicle performance in logistics clusters. It encompasses a comprehensive literature review, research methodology, data sources, variables, feature engineering, and model training and evaluation and F-test analysis was done to identify and verify the relationships between attributes and the target variable. The findings highlight the model’s efficacy, with a low mean squared error (MSE) value of 3.42, indicating its accuracy in predicting performance metrics. The high R-squared (R2) score of 0.921 emphasizes its ability to capture relationships between input characteristics and performance metrics. The model’s training and testing accuracy further attest to its reliability and generalization capabilities. In interpretation, this research underscores the practical significance of the findings. The regression-based model provides a practical solution for the logistics industry, enabling informed decisions regarding resource allocation, maintenance planning, and delivery route optimization. This contributes to enhanced overall logistics performance and customer service. By addressing performance gaps and embracing modern logistics technologies, the study supports the ongoing evolution of vehicle performance management in logistics clusters, fostering increased competitiveness and sustainability in the logistics sector. 展开更多
关键词 Mean Squared Error R2 Score F-TEST MSE
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Ultrahigh thermoelectric properties of p‐type Bi_(x)Sb_(2−x)Te_(3)thin films with exceptional flexibility for wearable energy harvesting
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作者 Zhuang‐Hao Zheng Yi‐Ming Zhong +9 位作者 Yi‐Liu Li Mohammad Nisar Adil Mansoor Fu Li Shuo Chen Guang‐Xing Liang Ping Fan Dongyan Xu Meng Wei Yue‐Xing Chen 《Carbon Energy》 SCIE EI CAS CSCD 2024年第8期273-284,共12页
Use of a flexible thermoelectric source is a feasible approach to realizing selfpowered wearable electronics and the Internet of Things.Inorganic thin films are promising candidates for fabricating flexible power supp... Use of a flexible thermoelectric source is a feasible approach to realizing selfpowered wearable electronics and the Internet of Things.Inorganic thin films are promising candidates for fabricating flexible power supply,but obtaining highthermoelectric‐performance thin films remains a big challenge.In the present work,a p‐type Bi_(x)Sb_(2−x)Te_(3)thin film is designed with a high figure of merit of 1.11 at 393 K and exceptional flexibility(less than 5%increase in resistance after 1000 cycles of bending at a radius of∼5 mm).The favorable comprehensive performance of the Bi_(x)Sb_(2−x)Te_(3)flexible thin film is due to its excellent crystallinity,optimized carrier concentration,and low elastic modulus,which have been verified by experiments and theoretical calculations.Further,a flexible device is fabricated using the prepared p‐type Bi_(x)Sb_(2−x)Te_(3)and n‐type Ag_(2)Se thin films.Consequently,an outstanding power density of∼1028μWcm^(−2)is achieved at a temperature difference of 25 K.This work extends a novel concept to the fabrication of highperformance flexible thin films and devices for wearable energy harvesting. 展开更多
关键词 Bi_(x)Sb_(2−x)Te_(3) electrical transport properties FLEXIBILITY THERMOELECTRIC
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Novel Sum-of-Sinusoids Simulation Channel Modeling for 6G Multiple-Input Multiple-Output Vehicle-to-Everything Communications
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作者 Hao Jiang Hongming Zhang Ting Liu 《China Communications》 SCIE CSCD 2024年第1期242-259,共18页
In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)environ... In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)environments.In the proposed sum-of-sinusoids(SoS)channel model,the waves that emerge from the transmitter undergo line-of-sight(LoS)and non-line-of-sight(NLoS)propagation to the receiver,which makes the model suitable for describing numerous V2X wireless communication scenarios for sixth-generation(6G).We derive expressions for the real and imaginary parts of the complex channel impulse response(CIR),which characterize the physical propagation characteristics of V2X wireless channels.The statistical properties of the real and imaginary parts of the complex CIRs,i.e.,autocorrelation functions(ACFs),Doppler power spectral densities(PSDs),cross-correlation functions(CCFs),and variances of ACFs and CCFs,are derived and discussed.Simulation results are generated and match those predicted by the underlying theory,demonstrating the accuracy of our derivation and analysis.The proposed framework and underlying theory arise as an efficient tool to investigate the statistical properties of 6G MIMO V2X communication systems. 展开更多
关键词 complex CIRs LoS and NLoS propagation components MIMO V2X communication environments SoS simulation channel model statistical properties
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MAML2重排阴性腮腺Warthin瘤样黏液表皮样癌1例并文献复习
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作者 宋汉香 文双雪 郭乔楠 《临床与实验病理学杂志》 CAS 北大核心 2024年第4期433-435,共3页
目的探讨原发于腮腺MAML2重排阴性的Warthin瘤样黏液表皮样癌(Warthin-like mucoepidermoid carcinoma,WT-MEC)的临床病理特征、诊断和鉴别诊断。方法收集1例原发于腮腺的WT-MEC临床资料,采用免疫组化EnVision两步法染色和FISH检测,分... 目的探讨原发于腮腺MAML2重排阴性的Warthin瘤样黏液表皮样癌(Warthin-like mucoepidermoid carcinoma,WT-MEC)的临床病理特征、诊断和鉴别诊断。方法收集1例原发于腮腺的WT-MEC临床资料,采用免疫组化EnVision两步法染色和FISH检测,分析其临床病理特征和预后的关系,并复习相关文献。结果眼观:肿瘤呈实性,多小叶状,边界大部分清楚,切面灰白、灰黄色,局部呈蜂窝状伴点灶性出血。镜检:大量呈多层排列的嗜酸性上皮、部分透明细胞样上皮,丰富的非肿瘤性淋巴细胞间质,可见淋巴滤泡。嗜酸性上皮细胞呈圆形或卵圆形、泡状核和嗜酸性胞质,核仁清楚,上皮内可见异型黏液细胞,还可见灶性分布的中间细胞和表皮样细胞。免疫表型:上皮细胞CK35βH11阳性、CD117部分阳性,表皮样细胞和中间细胞CK5/6、p63局灶阳性,S-100阴性,AB染色黏液呈阳性,Ki67增殖指数<5%。FISH检测:MAML2重排阴性。结论MAML2基因易位是诊断WT-MEC的金标准,当MAML2重排阴性不能除外时,需根据组织病理学特征和免疫组化综合分析。 展开更多
关键词 唾液腺肿瘤 Warthin瘤样黏液表皮样癌 MAML2重排阴性 临床病理特征 诊断 鉴别诊断
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Optimal parameter space for stabilizing the ferroelectric phase of Hf_(0.5)Zr_(0.5)O_(2) thin films under strain and electric fields
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作者 王侣锦 王聪 +4 位作者 周霖蔚 周谐宇 潘宇浩 吴幸 季威 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期509-517,共9页
Hafnia-based ferroelectric materials, like Hf_(0.5)Zr_(0.5)O_(2)(HZO), have received tremendous attention owing to their potentials for building ultra-thin ferroelectric devices. The orthorhombic(O)-phase of HZO is fe... Hafnia-based ferroelectric materials, like Hf_(0.5)Zr_(0.5)O_(2)(HZO), have received tremendous attention owing to their potentials for building ultra-thin ferroelectric devices. The orthorhombic(O)-phase of HZO is ferroelectric but metastable in its bulk form under ambient conditions, which poses a considerable challenge to maintaining the operation performance of HZO-based ferroelectric devices. Here, we theoretically addressed this issue that provides parameter spaces for stabilizing the O-phase of HZO thin-films under various conditions. Three mechanisms were found to be capable of lowering the relative energy of the O-phase, namely, more significant surface-bulk portion of(111) surfaces, compressive c-axis strain,and positive electric fields. Considering these mechanisms, we plotted two ternary phase diagrams for HZO thin-films where the strain was applied along the in-plane uniaxial and biaxial, respectively. These diagrams indicate the O-phase could be stabilized by solely shrinking the film-thickness below 12.26 nm, ascribed to its lower surface energies. All these results shed considerable light on designing more robust and higher-performance ferroelectric devices. 展开更多
关键词 Hf_(0.5)Zr_(0.5)O_(2) orthorhombic phase ferroelectric films phase stability thickness-dependent ternary phase diagrams
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