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Elevated CO_(2) increases soil redox potential by promoting root radial oxygen loss in paddy field

Journal of Environmental Sciences 2024年第2期136卷 11-20页

作者： Jie Li Han zhang Wenyi Xie Cheng Liu Xiaoyu Liu xuhui zhang Lianqing Li Genxing Pan Institute of Resource Ecosystem and Environment of AgricultureNanjing Agricultural UniversityNanjing 210095China College of Agriculture Nanjing Agricultural UniversityNanjing 210095China

Soil redox potential(Eh)plays an important role in the biogeochemical cycling of soil nutrients.Whereas its effect soil process and nutrients'availability under elevated atmospheric CO_(2) concentration and warming has seldom been investigated.Thus,in this study,a field experiment was used to elucidate the effect of elevated CO_(2) concentration and warming on soil Eh,redox-sensitive elements and root radial oxygen loss(ROL).We hypothesized elevated CO_(2) and warming could alter soil Eh by promoting or inhibiting ROL.We found that soil Eh in the rhizosphere was significantly higher than that of non-rhizosphere.Elevated CO_(2) enhanced soil Eh by 11.5%,which corresponded to a significant decrease in soil Fe^(2+)and Mn^(2+)concentration.Under elevated CO_(2),the concentration of Fe^(2+)and Mn^(2+)decreased by 14.7%and 13.7%,respectively.We also found that elevated CO_(2) altered rice root aerenchyma structure and promoted rice root ROL.Under elevated CO_(2),rice root ROL increased by 79.5%and 112.2%for Yangdao 6 and Changyou 5,respectively.Warming had no effect on soil Eh and rice root ROL.While warming increased the concentration of Mn^(2+)and SO_(4)^(2-)by 4.9%and 19.3%,respectively.There was a significant interaction between elevated CO_(2) and warming on Fe^(2+)and Mn^(2+).Under elevated CO_(2),warming had no effect on the concentration of Fe^(2+)but decreased Mn^(2+)concentration significantly.Our study demonstrated that elevated atmospheric CO_(2) in the future could increase soil Eh by promoting rice root ROL,which will alter some soil nutrients'availability,such as Fe^(2+)and Mn^(2+).

关键词： Atmospheric CO_(2)enrichment Global warming Soil redox potential FACE Rice root aerenchyma

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Energy-based Directional Pilot Protection for Distribution Networks with IBDGs Considering Unmeasured Load Switching

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 139-150页

作者： Chenghan Zhou Guibin Zou Shuo zhang xuhui Wen Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong UniversityJinan 250061China

Inverter-based distributed generations(IBDGs)are the main approach to utilizing clean energy in distribution networks(DNs).Compared with synchronous source,fault response of IBDG is very different.As a result,in DNs with high penetration of IBDGs,legacy protection schemes will no longer be applicable.In this paper,an energy-based directional pilot protection scheme suitabie for DNs with IBDGs is proposed.This scheme considers the large range of phase angle caused by IBDG integration and uses improved energy polarity criterion to determine fault direction.In addition,magnitude of energy is used to distinguish between faults and load switching to overcome maloperation of directional pilot protection caused by internal unmeasured load switching.The proposed scheme first uses local measured information to determine fault direction sign and then exchanges the direction sign with the remote terminal.This scheme does not require high-bandwidth communication and strict data synchronization,so it can be implemented at a low cost.Finally,simulation studies verify effectiveness of the proposed scheme.

关键词： Distribution network energy polarity inverterbased distributed generation pilot protection unmeasured load

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Clinical management of a rare melanoma case arising from congenital melanocytic nevus

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Genes & Diseases 2024年第3期11卷 79-82页

作者： Ruixin Jiang Yan Wang xuhui Ma Xinyang Xuanyuan Yanjie zhang Bin Jiang Weizhen zhang Hanlin Zeng Department of Oncology Shanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai 201900China Department of Oncology The Third People's Hospital of ZhengzhouZhengzhouHenan 450000China Department of Oral&Maxillofacial-Head and Neck Oncology Shanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai 200125China Shanghai Institute of Precision Medicine Shanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai200125China Department of Dermatology Shanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai 200000China

Congenital melanocytic nevi(CMNs)are skin lesions characterized by benign melanocytic proliferations and present at birth or shortly thereafter.Large and giant CMNs,with a projected adult size≥20 cm and 40 cm in diameter respectively,are more likely to develop into malignant melanoma.In most cases,melanoma arising from congenital melanocytic nevus(CMN)is particularly aggressive.

关键词： melanoma congenital melan

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A 16-bit 18-MSPS flash-assisted SAR ADC with hybrid synchronous and asynchronous control logic

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Journal of Semiconductors 2024年第6期45卷 3-12页

作者： Junyao Ji Xinao Ji Ziyu Zhou Zhichao Dai xuhui Chen Jie zhang Zheng Jiang Hong zhang School of Microelectronics Xi'an Jiaotong UniversityXi'an 710049China Qingdao Hi-image Tech.Co.Ltd. Qingdao 266100China

This paper presents a 16-bit,18-MSPS(million samples per second)flash-assisted successive-approximation-register(SAR)analog-to-digital converter(ADC)utilizing hybrid synchronous and asynchronous(HYSAS)timing control logic based on an on-chip delay-locked loop(DLL).The HYSAS scheme can provide a longer settling time for the capacitive digital-to-analog converter(CDAC)than the synchronous and asynchronous SAR ADC.Therefore,the issue of incomplete settling or ringing in the DAC voltage for cases of either on-chip or off-chip reference voltage can be solved to a large extent.In addition,the fore-ground calibration of the CDAC’s mismatch is performed with a finite-impulse-response bandpass filter(FIR-BPF)based least-mean-square(LMS)algorithm in an off-chip FPGA(field programmable gate array).Fabricated in 40-nm CMOS process,the proto-type ADC achieves 94.02-dB spurious-free dynamic range(SFDR),and 75.98-dB signal-to-noise-and-distortion ratio(SNDR)for a 2.88-MHz input under 18-MSPS sampling rate.

关键词： SAR ADC control logic reference ringing DAC incomplete settling

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Factors Influencing the Spatial Variability of Air Temperature Urban Heat Island Intensity in Chinese Cities

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Advances in Atmospheric Sciences 2024年第5期41卷 817-829页

作者： Heng LYU Wei WANG Keer zhang Chang CAO Wei XIAO xuhui LEE Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Ecosystem Carbon Source and SinkChina Meteorological Administration(ECSS-CMA)/Jiangsu Key Laboratory of Agricultural MeteorologyNanjing University of Information Science&TechnologyNanjing 210044China Key Laboratory of Urban Meteorology China Meteorological AdministrationBeijing 100089China School of the Environment Yale UniversityNew HavenCT 06511USA

Few studies have investigated the spatial patterns of the air temperature urban heat island(AUHI)and its controlling factors.In this study,the data generated by an urban climate model were used to investigate the spatial variations of the AUHI across China and the underlying climate and ecological drivers.A total of 355 urban clusters were used.We performed an attribution analysis of the AUHI to elucidate the mechanisms underlying its formation.The results show that the midday AUHI is negatively correlated with climate wetness(humid:0.34 K;semi-humid:0.50 K;semi-arid:0.73 K).The annual mean midnight AUHI does not show discernible spatial patterns,but is generally stronger than the midday AUHI.The urban–rural difference in convection efficiency is the largest contributor to the midday AUHI in the humid(0.32±0.09 K)and the semi-arid(0.36±0.11 K)climate zones.The release of anthropogenic heat from urban land is the dominant contributor to the midnight AUHI in all three climate zones.The rural vegetation density is the most important driver of the daytime and nighttime AUHI spatial variations.A spatial covariance analysis revealed that this vegetation influence is manifested mainly through its regulation of heat storage in rural land.

关键词： air temperature urban heat island spatial variations biophysical drivers Chinese cities climate model

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Multi-field Coupled Inverse Hall–Petch Relations for Ferroelectric Nanocrystals

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Acta Mechanica Solida Sinica 2024年第1期37卷 139-147页

作者： Xiaodong zhang Wei Yan xuhui Lou Yujun Chen Zhihong Zhou Qingyuan Wang Lianhua Ma Xiaobao Tian Non-Destructive Testing Laboratory School of Quality and Technical SupervisionHebei UniversityBaoding 071002China AVIC Huiyang Aviation Propeller Co. LtdBaoding 071051China Department of Mechanics and Engineering Sichuan UniversityChengdu 610065China Yibin Institute of Industrial Technology Sichuan University Yibin ParkYibin 644000China Research Institute of Interdisciplinary Sciences(RISE) Dongguan University of TechnologyDongguan 523808China School of Materials Science and Engineering Dongguan University of TechnologyDongguan 523808China

Tailoring grain size can improve the strength of polycrystals by regulating the proportion of grains to grain boundaries and the interaction area.As the grain size decreases to the nanoscale,the deformation mechanism in polycrystals shifts from being primarily mediated by dislocations to deformation occurring within the grains and grain boundaries.However,the mechanism responsible for fine-grain strengthening in ferroelectric materials remains unclear,primarily due to the complex multi-field coupling effect arising from spontaneous polarization.Through molecular dynamics simulations,we investigate the strengthening mechanism of barium titanate(BaTiO3),with extremely fine-grain sizes.This material exhibits an inverse Hall–Petch relationship between grain size and strength,rooting in the inhomogeneous concentration of atomic strain and grain rotation.Furthermore,we present a theoretical model to predict the transition from the inverse Hall–Petch stage to the Hall–Petch stage based on strength variations with size,which aligns well with the simulation results.It has been found that the piezoelectric properties of the BaTiO3 are affected by polarization domain switching at various grain sizes.This study enhances our understanding of the atomic-scale mechanisms that contribute to the performance evolution of fine-grain nano-ferroelectric materials.It also provides valuable insights into the design of extremely small-scale ferroelectric components.

关键词： Ferroelectrics Multi-field coupling Molecular dynamics Fine-grain reinforcement Inverse Hall-Petch effect

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Hollow FeCoNiAl microspheres with stabilized magnetic properties for microwave absorption

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Nano Research 2024年第3期17卷 2079-2087页

作者： Linhe Yu Gangjie Lian Guozhen Zhu Sue Ren Yanfang Du xuhui Xiong Rui Chen Jincang zhang Wenbin You Renchao Che Institute of Advanced Materials College of Chemistry and Chemical EngineeringJiangxi Normal UniversityNanchang 330022China Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative MaterialsAcademy for Engineering&TechnologyFudan UniversityShanghai 200438China Zhejiang Laboratory Hangzhou 311100China Capital Aerospace Machinery Corporation Limited Beijing 100000China AECC Beijing Institute of Aeronautical Materials Beijing 100095China International Center for Quantum and Molecular Structures Materials Genome InstitutePhysics DepartmentShanghai UniversityShanghai 200444China

Development of high-performance microwave absorption materials(MAM)with stabilized magnetic properties at high temperatures is specifically essential but remains challenging.Moreover,the Snoke's limitation restrains the microwave absorption(MA)property of magnetic materials.Modulating alloy components is considered an effective way to solve the aforementioned problems.Herein,a hollow medium-entropy FeCoNiAl alloy with a stable magnetic property is prepared via simple spray-drying and two-step annealing for efficient MA.FeCoNiAl exhibited an ultrabroad effective absorption band(EAB)of 5.84 GHz(12.16–18 GHz)at a thickness of just 1.6 mm,revealing an excellent absorption capability.Furthermore,the MA mechanism of FeCoNiAl is comprehensively investigated via off-axis holography.Finally,the electromagnetic properties,antioxidant properties,and residual magnetism at high temperatures of FeCoNiAl alloys are summarized in detail,providing new insights into the preparation of MAM operating at elevated temperatures.

关键词： microwave absorption hollow structure magnetic stability multiple microwave absorption mechanism

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Preparation and characteristic study of Schottky diodes based on Ga_(2)O_(3)thin films

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The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 28-37页

作者： zhang xuhui Chen Haifeng Liu Xiangtai Lu Qin Wang Zhan Cheng Hang Che Lujie Guan Youyou Han Xiaocong School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China

This study uses atomic layer deposition(ALD)to grow Ga_(2)O_(3)films on SiO_(2)substrates and investigates the influence of film thickness and annealing temperature on film quality.Schottky diode devices are fabricated based on the grown Ga_(2)O_(3)films,and the effects of annealing temperature,electrode size,and electrode spacing on the electrical characteristics of the devices are studied.The results show that as the film thickness increases,the breakdown voltage of the fabricated devices also increases.A Schottky diode with a thickness of 240 nm can achieve a reverse breakdown voltage of 300 V.The film quality significantly improves as the annealing temperature of the film increases.At a voltage of 5 V,the current of the film annealed at 900℃is 64 times that of the film annealed at 700℃.The optimum annealing temperature for Ohmic contact electrodes is 450℃.At 550℃,the Ohmic contact metal tends to burn,and the performance of the device is reduced.Reducing the electrode spacing increases the forward current of the device but decreases the reverse breakdown voltage.Increasing the Schottky contact electrode size increases the forward current,but the change is not significant,and there is no significant change in the reverse breakdown voltage.The device also performs well at high temperatures,with a reverse breakdown voltage of 220 V at 125℃.

关键词： atomic layer deposition(ALD) Ga_(2)O_(3)film Schottky diode annealing temperature

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Performance study of vertical MSM solar-blind photodetectorsbased onβ-Ga_(2)O_(3)thin film

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The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 17-27页

作者： Chen Haifeng Che Lujie Lu Qin Wang Shaoqing Liu Xiangtai Liu Zhanhang Guan Youyou Zhao Xu Cheng Hang Han Xiaocong zhang xuhui School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China

In this work,β-Ga_(2)O_(3)thin films were grown on SiO_(2)substrate by atomic layer deposition(ALD)and annealed in N_(2)atmosphere to enhance the crystallization quality of the thin films,which were verified from X-rays diffraction(XRD).Based on the grownβ-Ga_(2)O_(3)thin films,vertical metal-semiconductor-metal(MSM)interdigital photodetectors(PDs)were fabricated and investigated.The PDs have an ultralow dark current of 1.92 pA,ultra-high photo-to-dark current ratio(PDCR)of 1.7×10^(6),and ultra-high detectivity of 4.25×10^(14)Jones at a bias voltage of 10 V under 254 nm deep ultraviolet(DUV).Compared with the horizontal MSM PDs under the same process,the PDCR and detectivity of the fabricated vertical PDs are increased by 1000 times and 100 times,respectively.In addition,the vertical PDs possess a high responsivity of 34.24 A/W and an external quantum efficiency of 1.67×10^(4)%,and also exhibit robustness and repeatability,which indicate excellent performance.Then the effects of electrode size and external irradiation conditions on the performance of the vertical PDs continued to be investigated.

关键词： Ga_(2)O_(3) atomic layer deposition(ALD) annealing vertical metal-semiconductor-metal(MSM)interdigital photodetectors

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High-performance Ag_(2)BiI_(5)Pb-free perovskite photodetector

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Photonics Research 2022年第8期10卷 1886-1891页

作者： ZIHAO SHUANG HAI ZHOU DINGJUN WU xuhui zhang BOAO XIAO JINXIA DUAN HAO WANG International School of Microelectronics Dongguan University of TechnologyDongguan 523808China Hubei Yangtze Memory Laboratories Wuhan 430205China School of Microelectronics Hubei UniversityWuhan 430062China

Recently,lead-free all-inorganic halide perovskites have attracted great interest because they not only have the merits of the halide perovskite family,but also are non-toxic.However,the commercialization of lead-free allinorganic perovskites is restricted by their relatively low performances,which are usually caused by the fabrication methods and undesirable interfaces between the active layer and carrier transport layers.Herein,we demonstrate a solution-processed route for high-quality Ag_(2)BiI_(5) lead-free perovskite film by adopting ideal electron transport material SnO_(2)and a carbon electrode.By optimizing the fabrication process and tailoring the composition of the perovskite active layer,a high-performance photodetector(PD)with an FTO∕SnO_(2)∕Ag_(2)BiI_(5)∕carbon structure PD is first fabricated,which shows good self-powered performance with a detectivity of as high as 5.3×10^(12)Jones and a linear dynamic range of up to 138 d B,which are better than those of the reported Pb-free perovskite PDs and comparable to high-performance Pb-based perovskite PDs.In addition,our unpackaged PDs show good light,thermal,and storage stability in air.Our results provide a special route for the development of lead-free perovskite devices in an environmentally friendly field.

关键词： field. perovskite performance

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