检索结果-南通市图书馆

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

在线全文

学校读者我要写书评

暂无评论

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

Preparation and characteristic study of Schottky diodes based on GaOthin films

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2024年

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 Telecommunications

This study uses atomic layer deposition (ALD) to grow Ga2O3films on SiO2substrates and investigates the influence of film thickness and annealing temperature on film quality. Schottky diode devices are fabricated based on the grown Ga2O3films， 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：

Random gradient-free method for online distributed optimization with strongly pseudoconvex cost functions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Control Theory and Technology 2024年第1期22卷 14-24页

作者： Xiaoxi Yan cheng Li Kaihong Lu hang Xu School of Electrical and Information Engineering Jiangsu UniversityZhenjiang212013JiangsuChina College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao266590ShandongChina

This paper focuses on the online distributed optimization problem based on multi-agent systems. In this problem, each agent can only access its own cost function and a convex set, and can only exchange local state information with its current neighbors through a time-varying digraph. In addition, the agents do not have access to the information about the current cost functions until decisions are made. Different from most existing works on online distributed optimization, here we consider the case where the cost functions are strongly pseudoconvex and real gradients of the cost functions are not available. To handle this problem, a random gradient-free online distributed algorithm involving the multi-point gradient estimator is proposed. Of particular interest is that under the proposed algorithm, each agent only uses the estimation information of gradients instead of the real gradient information to make decisions. The dynamic regret is employed to measure the proposed algorithm. We prove that if the cumulative deviation of the minimizer sequence grows within a certain rate, then the expectation of dynamic regret increases sublinearly. Finally, a simulation example is given to corroborate the validity of our results.

关键词： Multi-agent system Online distributed optimization Pseudoconvex optimization Random gradient-free method

Pre-MASLD:Should it be defined separately?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2024年第1期23卷 1-3页

作者： hang-Kai Huang You-Ming Li cheng-Fu Xu Department of Gastroenterology Zhejiang Provincial Clinical Research Center for Digestive Diseasesthe First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China

Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic liver diseases,yet it has not received sufficient attention[1].Over the past two decades,the overall global prevalence of NAFLD has risen from 25%to 37%[2].The disease burden of NAFLD is fueled by the epidemic of obesity and diabetes[3].It is estimated that more than half of patients with diabetes have NAFLD.

关键词： NAFLD liver diseases

Orbital angular momentum-mediated machine learning for high-accuracy mode-feature encoding

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第3期13卷 466-477页

作者： Xinyuan Fang Xiaonan Hu Baoli Li hang Su Ke cheng Haitao Luan Min Gu Institute of Photonic Chips University of Shanghai for Science and TechnologyShanghai 200093China Centre for Artificial-Intelligence Nanophotonics School of Optical-Electrical and Computer EngineeringUniversity of Shanghai for Science and TechnologyShanghai 200093China

Machine learning with optical neural networks has featured unique advantages of the information processing including high speed,ultrawide bandwidths and low energy consumption because the optical dimensions(time,space,wavelength,and polarization)could be utilized to increase the degree of freedom.However,due to the lack of the capability to extract the information features in the orbital angular momentum(OAM)domain,the theoretically unlimited OAM states have never been exploited to represent the signal of the input/output nodes in the neural network model.Here,we demonstrate OAM-mediated machine learning with an all-optical convolutional neural network(CNN)based on Laguerre-Gaussian(LG)beam modes with diverse diffraction losses.The proposed CNN architecture is composed of a trainable OAM mode-dispersion impulse as a convolutional kernel for feature extraction,and deep-learning diffractive layers as a classifier.The resultant OAM mode-dispersion selectivity can be applied in information mode-feature encoding,leading to an accuracy as high as 97.2%for MNIST database through detecting the energy weighting coefficients of the encoded OAM modes,as well as a resistance to eavesdropping in point-to-point free-space transmission.Moreover,through extending the target encoded modes into multiplexed OAM states,we realize all-optical dimension reduction for anomaly detection with an accuracy of 85%.Our work provides a deep insight to the mechanism of machine learning with spatial modes basis,which can be further utilized to improve the performances of various machine-vision tasks by constructing the unsupervised learning-based auto-encoder.

关键词： polarization mode momentum

New insight into Ca^(2+)-permeable channel in plant immunity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第3期66卷 623-631页

作者： Wei Wang hang-Yuan cheng Jian-Min Zhou State Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China CAS Center for Excellence in Biotic Interactions University of Chinese Academy of SciencesBeijing 100049China College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing 100049China Hainan Yazhou Bay Seed Laboratory Sanya 572025China

Calcium ions(Ca^(2+)) are crucial intracellular second messengers in eukaryotic cells. Upon pathogen perception, plants generate a transient and rapid increase in cytoplasmic Ca^(2+)levels, which is subsequently decoded by Ca^(2+)sensors and effectors to activate downstream immune responses. The elevation of cytosolic Ca^(2+)is commonly attributed to Ca^(2+)influx mediated by plasma membranelocalized Ca^(2+)–permeable channels. However, the contribution of Ca^(2+)release triggered by intracellular Ca^(2+)-permeable channels in shaping Ca^(2+)signaling associated with plant immunity remains poorly understood. This review discusses recent advances in understanding the mechanism underlying the shaping of Ca^(2+)signatures upon the activation of immune receptors, with particular emphasis on the identification of intracellular immune receptors as non-canonical Ca^(2+)-permeable channels. We also discuss the involvement of Ca^(2+)release from the endoplasmic reticulum in generating Ca^(2+)signaling during plant immunity.

关键词： Ca^(2+)-permeable channels endoplasmic reticulum phosphorylation plant immunity resistosome

Ensemble projections of climate and streamflow in a typical basin of semi-arid steppes in Mongolian Plateau of 2021-2100

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第2期15卷 230-243页

作者： hang PAN Jian-Ping TANG Liang cheng Man-Chun LI Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Nanjing UniversityNanjing 210023China School of Geography and Ocean Science Nanjing UniversityNanjing 210023China Key Laboratory of Mesoscale Severe Weather/Ministry of Education Nanjing UniversityNanjing 210023China School of Atmospheric Sciences Nanjing UniversityNanjing 210023China

The Kherlen River is the main water source for Hulun Lake,the largest lake in northern China.Due to reduced inflow from the Kherlen River,Hulun Lake experienced rapid shrinkage at the beginning of the 21st century,posing a serious threat to the ecological security of northern China.However,there is still a significant lack of projections regarding future climate change and its hydrological response in the Kherlen River basin.This study analyzed the projected climate and streamflow changes in the Kherlen River basin,a vital yet vulnerable international semi-arid steppes type basin.A combination of multi-model ensemble projection techniques,and the soil and water assessment tool(SWAT)model was employed to examine the spatio-temporal changes in precipitation,temperature,streamflow,and the associated uncertainties in the basin.The temperature(an increase of 1.84-6.42℃)and the precipitation(an increase of 15.0-46.0 mm)of Kherlen River basin are projected to increase by 2100,leading to a rise in streamflow(1.08-4.78 m^(3) s^(-1)).The upstream of the Kherlen River exhibits remarkable increasing trends in precipitation,which has a dominant influence on streamflow of Kherlen River.Noteworthy increases in streamflow are observed in April,August,September,and October compared to the reference period(1971-2000).These findings suggest a partial alleviation of water scarcity in the Kherlen River,but also an increased likelihood of hydrological extreme events.The projected temperature increase in the Kherlen River basin exhibits the smallest uncertainty,while more pronounced uncertainties are found in precipitation and streamflow.The spread among the results of CMIP6 models is greater than that of CMIP5 models,with lower signal-to-noise ratio(SNR)values for temperature,precipitation,and streamflow.

关键词： Climate change Flow projection Uncertainty SWAT Mongolian Plateau

Intelligent Predetermination of Generator Tripping Scheme: Knowledge Fusion-based Deep Reinforcement Learning Framework

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第1期10卷 66-75页

作者： Lingkang Zeng Wei Yao Ze Hu hang Shuai Zhouping Li Jinyu Wen Shijie cheng State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronics EngineeringHuazhong University of Science and TechnologyWuhan 430074China Dispatching and Control Center Central China Branch of State Grid Corporation of ChinaWuhan 430077China. Department of Electrical Engineering and Computer Science University of TennesseeKnoxvilleTN 37996USA

Generator tripping scheme(GTS)is the most commonly used scheme to prevent power systems from losing safety and stability.Usually,GTS is composed of offline predetermination and real-time scenario match.However,it is extremely time-consuming and labor-intensive for manual predetermination for a large-scale modern power system.To improve efficiency of predetermination,this paper proposes a framework of knowledge fusion-based deep reinforcement learning(KF-DRL)for intelligent predetermination of GTS.First,the Markov Decision Process(MDP)for GTS problem is formulated based on transient instability events.Then,linear action space is developed to reduce dimensionality of action space for multiple controllable generators.Especially,KF-DRL leverages domain knowledge about GTS to mask invalid actions during the decision-making process.This can enhance the efficiency and learning process.Moreover,the graph convolutional network(GCN)is introduced to the policy network for enhanced learning ability.Numerical simulation results obtained on New England power system demonstrate superiority of the proposed KF-DRL framework for GTS over the purely data-driven DRL method.

关键词： Deep reinforcement learning generator tripping scheme graph convolutional network invalid action masking knowledgefusion

Controllable CPL response driven by achiral UV-photosensitive dichroic dye through cholesteric liquid crystals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第4期67卷 1250-1255页

作者： Yihan Chen Yang Li hang Li Lulu Li Yiwu Quan Yixiang cheng State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Key Laboratory of High-Performance Polymer Material and Technology of Ministry of Education School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

Versatile stimuli-responsive circularly polarized luminescent(CPL)materials have potential applications in information storage,security encryption,and intelligent displays.In this study,the Z/E isomerization of ultraviolet(UV)-photosensitive achiralα-cyanostilbene derivative was used as an achiral dichroic dye(Switch)to drive the controllable CPL-active response in cholesteric liquid crystals(CLCs).Under irradiation by 365 nm UV light,the resulting CLCs-Z-Switch underwent a Z-to-E configuration isomerization as CLCs-E-Switch,accompanied by a decrease in its dichroic order parameter(SFvalue)from 0.15to 0.07.Although the quantum yield(QY)of CLCs-E-Switch increased from 8.1%(CLCs-Z-Switch)to 16.8%,the corresponding glumvalues of CPL emission decreased from+0.55/-0.57 to+0.37/-0.39 due to a decrease in the order of helical arrangement of E-Switch in E7 media.This study enables photosensitive CLCs-Switch to be applied for optical information storage devices.

关键词： circularly polarized luminescent photosensitive dichroic dye cholesteric liquid crystals chiral induction