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Chinese Physics B 2016年第9期25卷 474-479页

作者：周书星齐鸣艾立鹍徐安怀 State key laboratory of Functional Materials for informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences

The structure of In P-based In_xGa_（1-x） As/In0.52Al0.48 As pseudomorphic high electron mobility transistor（PHEMT）was optimized in detail.Effects of growth temperature,growth interruption time,Si δ-doping condition,channel thickness and In content,and inserted Al As monolayer（ML） on the two-dimensional electron gas（2DEG） performance were investigated carefully.It was found that the use of the inserted Al As monolayer has an enhancement effect on the mobility due to the reduction of interface roughness and the suppression of Si movement.With optimization of the growth parameters,the structures composed of a 10 nm thick In0.75Ga0.25 As channel layer and a 3 nm thick Al As/In0.52Al0.48 As superlattices spacer layer exhibited electron mobilities as high as 12500 cm^2·V-1·s^（-1）（300 K） and 53500 cm^2·V~（-1_·s^（-1）（77 K） and the corresponding sheet carrier concentrations（Ns） of 2.8×10^（12）cm^（-2）and 2.9×1012cm^（-2）,respectively.To the best of the authors＇ knowledge,this is the highest reported room temperature mobility for In P-based HEMTs with a spacer of 3 nm to date.

关键词： high electron mobility transistor two-dimensional electron gas InP

Continuous adjoint-based error estimation and its application to adaptive discontinuous Galerkin method

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Applied Mathematics and Mechanics(English Edition) 2016年第11期37卷 1419-1430页

作者： Huiqiang YUE Tiegang LIU V.SHAYDUROV key laboratory of Mathematics Informatics and Behavioral Semantics Ministry of EducationSchool of Mathematics and Systems Science Beihang University

An adaptive mesh refinement algorithm based on a continuous adjoint ap- proach is developed. Both the primal equation and the adjoint equation are approximated with the discontinuous Galerkin （DG） method. The proposed adaptive algorithm is used in compressible Euler equations. Numerical tests are made to show the superiority of the proposed adaptive algorithm.

关键词： adaptivity discontinuous Galerkin （DG） adjoint

A Cross-Domain Ontology Semantic Representation Based on NCBI-BlueBERT Embedding

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Chinese Journal of Electronics 2022年第5期31卷 860-869页

作者： ZHAO Lingling WANG Junjie WANG Chunyu GUO Maozu Faculty of Computing Harbin Institute of Technology Department of Medical informatics School of Biomedical Engineering and InformaticsNanjing Medical University Beijing key laboratory of Intelligent Processing for Building Big Data School of Electrical and Information Engineering Beijing University of Civil Engineering and Architecture

A common but critical task in biological ontologies data analysis is to compare the difference between ontologies. There have been numerous ontologybased semantic-similarity measures proposed in specific ontology domain, but it still remains a challenge for crossdomain ontologies comparison. An ontology contains the scientific natural language description for the corresponding biological aspect. Therefore, we develop a new method based on natural language processing(NLP) representation model bidirectional encoder representations from transformers(BERT) for cross-domain semantic representation of biological ontologies. This article uses the BERT model to represent the word-level of the ontologies as a set of vectors, facilitating the semantic analysis or comparing the biomedical entities named in an ontology or associated with ontology terms. We evaluated the ability of our method in two experiments: calculating similarities of pair-wise disease ontology and human phenotype ontology terms and predicting the pair-wise of proteins interaction. The experimental results demonstrated the comparative performance. This gives promise to the development of NLP methods in biological data analysis.

关键词： Ontology Semantic representation Semantic similarity Protein-protein interaction

The effects of factor generalization scales on the reproduction of dynamic urban growth

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Geo-Spatial Information Science 2022年第3期25卷 457-475页

作者： Yongjiu Feng Peiqi Wu Xiaohua Tong Pengshuo Li Rong Wang Yilun Zhou Jiafeng Wang Jinyu Zhao College of Surveying&Geo-informatics Tongji UniversityShanghaiChina The Shanghai key laboratory of Space Mapping and Remote Sensing for Planetary Exploration Tongji UniversityShanghaiChina

The production and selection of driving factors are essential to building a strong Cellular Automata(CA)model of dynamic urban growth simulation.A critical issue that should be addressed is how the spatial representation and the generalization scale of driving factors affect the CA modeling and the simulation results.It is challenging to evaluate the effectiveness of the selected driving factors because they have no true values.To explore the impacts of the generalization scales,we produced nine sets of driving factors at nine scales to calibrate the CA models based on the Particle Swarm Optimization(CAPSO)and applied them to simulate urban growth of Suzhou during 2000-2020.Our results show that the driving factors at a smaller scale have much better performance in explaining urban growth simulations as inferred by the Explained Residual Deviance(ERD)of the Generalized Additive Models(GAMs).Specifically,the ERD declined from 51.9%to 45.9%as the factor scale became larger during 2000-2020,but there was a peak value(52.2%)at Scale-2.For all simulations during 2000-2020,the CAPSO models with larger-scale factors have slightly lower overall accuracy and Figure-of-Merit(FOM),which respectively decreased by 3.1%and 4.4%as compared to the CA models with scale-free factors.We concluded that the driving factors at a smaller scale(200~400 m for point-like facilities and 7~14 m for line-like facilities)can build more accurate CA models to simulate urban growth patterns,and the optimal scale for factors can be identified using the ERD.This study contributes to the methods of evaluating the effectiveness of driving factor production and reveals the impacts of spatial representation of factors on the CA modeling and simulation considering the factor generalization scales.

关键词： Cellular automata urban growth driving factors scale effects generalized additive model

Image processing methods to evaluate tomato and zucchini damage in post-harvest stages

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International Journal of agricultural and Biological Engineering 2017年第5期10卷 126-133页

作者： José Antonio Alvarez-Bermejo Cynthia Giagnocavo Li Ming Encarnación Castillo Morales Diego P.Morales Santos Yang Xinting Department of informatics CeiA3University of AlmeriaAlmeriaCP 04120Spain Cátedra(Chair)Coexphal-UAL of Horticulture Cooperative Studies and Sustainable DevelopmentUniversity of AlmeríaSpain Beijing Research Center for Information Technology in agriculture/National Engineering Research Center for Information Technology in agriculture/National Engineering laboratory for agri-product Quality Traceability/key laboratory for Information Technologies in agriculture Ministry of AgricultureBeijing 100097China Department of Electronics and Computer Technology Facultad de CienciasGranadaCP 18071Spain

Through the supply chain,the quality or quality change of the products can generate important losses.The quality control in some steps is made manually that supposes a high level of subjectivity,controlling the quality and its evolution using automatic systems can suppose a reduction of the losses.Testing some automatic image analysis techniques in the case of tomatoes and zucchini is the main objective of this study.Two steps in the supply chain are considered,the feeding of the raw products into the handling chain(because low quality generates a reduction of the chain productivity)and the cool storage of the processed products(as the value at the market is reduced).It was proposed to analyze the incoming products at the head the processing line using CCD cameras to detect low quality and/or dirty products(corresponding to specific farmers/suppliers,it should be asked to improve to maintain the productivity of the line).The second stage is analyzing the evolution of the products along the cool chain(storage and transport),the use of an App developed to be use under Android was proposed to substitute the“visual”evaluation used in practice.The algorithms used,including stages of pre-treatment,segmentation,analysis and presentation of the results take account of the short time available and the limited capacity of the batteries.High performance techniques were applied to the homography stage to discard some of the images,resulting in better performance.Also threads and renderscript kernels were created to parallelize the methods used on the resulting images being able to inspect faster the products.The proposed method achieves success rates comparable to,and improving,the expert inspection.

关键词： image processing color space smartphone efficient stitching homography controlled supervision artificial vision embedded parallel processing injury assessment traceability post-harvest control feature detection

Delaying application time of slow-release fertilizer increases soil rhizosphere nitrogen content,root activity,and grain yield of spring maize

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The Crop Journal 2022年第6期10卷 1798-1806页

作者： Guanghao Li Pengxiao Fu Guigen Cheng Weiping Lu Dalei Lu Jiangsu key laboratory of Crop Genetics and Physiology/Jiangsu key laboratory of Crop Cultivation and Physiology/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou UniversityYangzhou 225009JiangsuChina Joint International Research laboratory of agriculture and agri-Product Safety the Ministry of Education of ChinaYangzhou UniversityYangzhou 225009JiangsuChina

Application of slow-release fertilizer(SF)is a nutrient-management measure aimed at improving maize nutrient use and yield and saving labor cost.One-time application of SF at sowing usually results in nutrient deficiency during the post-silking stage,owing to the long growth period of spring maize.This study was conducted to investigate the effects on spring maize of SF application stage(zero,three-,and six-leaf stages,designated as SF0,SF3,and SF6,respectively)on grain yield,total soil rhizosphere nitrogen(N)content,and root activity,in comparison with the conventional fertilization mode(CF,application of compound fertilizer at sowing time,and topdressing urea at six-leaf and tasseling stages)at the same fertilization level as the control.Compared with no fertilization(F0)and CF,SF increased grain number and weight.The maize cultivars Suyu 30(SY30)and Jiangyu 877(JY877)produced the highest grain yield and net return under SF6 treatment over the three years.SF6 increased enzymatic activities including oxidoreductase,hydrolase,transferase,and lyase in rhizosphere soil at silking(R1)and milking stages(R3).SF6 increased the total N contents of rhizosphere soil by 7.1%at R1 and 9.2%R3 stages compared with SF0.The activities of antioxidant enzymes in roots were increased under SF6 treatments at R1and R3.The mean root activities of SF0,SF3,and SF6 increased by 7.1%,12.8%,and 20.5%compared with CF at R1 and by 8.8%,13.0%,and 23.5%at R3.Delaying the application time of SF could increase grain yield by increasing total N content of rhizosphere soil,delaying root senescence,and increasing root activity at the late reproductive stage.Applying SF at the six-leaf stage is recommended as an effective fertilization strategy for the sustainable production of spring maize in southern China.

关键词： Spring maize Slow-release fertilizer Fertilization stage Root activity Grain yield

Ta-Doped Sb2Te Allows Ultrafast Phase-Change Memory with Excellent High-Temperature Operation Characteristics

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Nano-Micro Letters 2021年第2期13卷 221-231页

作者： Yuan Xue Shuai Yan Shilong Lv Sannian Song Zhitang Song State key laboratory of Functional Materials for informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050People’s Republic of China

Phase-change memory(PCM)has considerable promise for new applications based on von Neumann and emerging neuromorphic computing systems.However,a key challenge in harnessing the advantages of PCM devices is achieving high-speed operation of these devices at elevated temperatures,which is critical for the efficient processing and reliable storage of data at full capacity.Herein,we report a novel PCM device based on Ta-doped antimony telluride(Sb2Te),which exhibits both high-speed characteristics and excellent high-temperature characteristics,with an operation speed of 2 ns,endurance of >106 cycles,and reversible switching at 140℃.The high coordination number of Ta and the strong bonds between Ta and Sb/Te atoms contribute to the robustness of the amorphous structure,which improves the thermal stability.Furthermore,the small grains in the three-dimensional limit lead to an increased energy efficiency and a reduced risk of layer segregation,reducing the power consumption and improving the long-term endurance.Our findings for this new Ta-Sb2Te material system can facilitate the development of PCMs with improved performance and novel applications.

关键词： Phase-change memory High speed Ta High-temperature operation

A comparative study of Ge/Au/Ni/Au-based ohmic contact on graphene

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Journal of Semiconductors 2014年第5期35卷 139-142页

作者：闵文超孙浩张祁连陈志蓥张燕辉于广辉孙晓玮 key laboratory of Terahertz Solid-State Technology Shanghai Institute of Microsystem and Information Technology University of Chinese Academy of Sciences State key laboratory of Functional Materials for informatics

Superior graphene-metal contacts can improve the performance of graphene devices. We report on an experimental demonstration of Ge/Au/Ni/Au-based ohmic contact on graphene. The transfer length method （TLM） is adopted to measure the resistivity of graphene-metal contacts. We designed a process flow, which can avoid residual photoresist at the interface of metal and graphene. Additionally, rapid thermal annealing （RTA） at different temperatures as a post-processing method is studied to improve graphene-metal contact. The results reveal that the contact resistivity of graphene and Ge/Au/Ni/Au can reach 10^-5 Ω· cm^2 after RTA, and that 350 ℃ is optimum annealing temperature for the contact of graphene-Ge/Au/Ni/Au. This paper provides guidance for fabrication and applications of graphene devices.

关键词： ohmic contact graphene anneal

Enhanced solar-blind ultraviolet single-photon detection with a Geiger-mode silicon avalanche photodiode

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Chinese Optics Letters 2016年第3期14卷 5-8页

作者：师亚帆李召辉冯百成颜佩琴杜秉乘周慧潘海峰吴光 State key laboratory of Precision Spectroscopy East China Normal University State key laboratory of Functional Materials for informatics Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences

Solar-blind ultraviolet detection is of great importance in astronomy and industrial and military applications. Here, we report enhanced solar-blind ultraviolet single-photon detection by a normal silicon avalanche photo- diode （Si APD） single-photon detector with a specially designed photon-collecting device. By re-focusing the reflected photon from the Si chip surface on the detection area by the aluminum-coated hemisphere, the detec- tion efficiency of the Si APD at 280 nm can be improved to 4.62%. This system has the potential for high-efficiency photon detection in the solar-blind ultraviolet regime with low noise.

关键词： Aluminum coatings Avalanche photodiodes Efficiency Military applications Photodetectors Photodiodes Photons Silicon

Prediction Model of Weekly Retail Price for Eggs Based on Chaotic Neural Network

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Journal of Integrative agriculture 2013年第12期12卷 2292-2299页

作者： LI Zhe-min CUI Li-guo XU Shi-wei WENG Ling-yun DONG Xiao-xia LI Gan-qiong YU Hai-peng agricultural Information Institute Chinese Academy of Agricultural Sciences/Key Laboratory of Agri-Information Service TechnologyMinistry of Agriculture

This paper establishes a short-term prediction model of weekly retail prices for eggs based on chaotic neural network with the weekly retail prices of eggs from January 2008 to December 2012 in China.In the process of determining the structure of the chaotic neural network,the number of input layer nodes of the network is calculated by reconstructing phase space and computing its saturated embedding dimension,and then the number of hidden layer nodes is estimated by trial and error.Finally,this model is applied to predict the retail prices of eggs and compared with ARIMA.The result shows that the chaotic neural network has better nonlinear fitting ability and higher precision in the prediction of weekly retail price of eggs.The empirical result also shows that the chaotic neural network can be widely used in the field of short-term prediction of agricultural prices.

关键词： chaos theory chaotic neural network neural network technology short-term prediction weekly retail price of eggs