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High-voltage trench-gate hole-gas enhancement-mode HEMT with multi-conduction channels

Science China(Information Sciences) 2018年第6期61卷 182-191页

作者： Chao YANG Xiaorong LUO Siyu deng Fu PENG Bo ZHANG State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China

In this paper, we present a novel high-voltage low on-resistance trench-gate（TG） hole-gas enhancement-mode（E-mode） high-electron mobility transistor（HEMT） with multi-conduction channels（MCs） and investigate its mechanism using simulations. This device features a repetitive Al N/Ga N heterojunction unit and a Ga N/Al0.26Ga0.74N hetero-junction. Its source and drain are located on the same side of the metal-insulator-semiconductor（MIS） TG, and the source is located beside the gate. During operation,first, 2-D electron gas（2 DEG） forms MCs at multiple Al N/Ga N hetero-interfaces. These MCs result in ultra-low specific on-resistance(Ron,sp) and improved transconductance（gm）. Second, 2-D hole gas（2 DHG）is induced at the Ga N/Al0.26Ga0.74N hetero-interface to prevent electrons from being injected from the source to the MCs. As such, E-mode operation is realized, which exceeds the performance of the conventional E-mode method by depleting the 2 DEG under the gate. Third, in the off-state, 2 DHG and 2 DEG are depleted into negative and positive charges, respectively, thereby forming the polarization junction. This depletion region is extended due to the electric field（E-field） modulation effect by the polarization junction,thereby achieving an enhanced breakdown voltage（BV）. Fourth, the drain-induced barrier lowering（DIBL）effect is significantly suppressed, which ensures a high BV and low leakage current. Additionally, due to the unique source location, the TG-MC-HEMT is smaller than the conventional MIS Al Ga N/Ga N HEMT（Con-HEMT）. The BV of the TG-MC-HEMT is 604 V and the Ron,sp value can be as small as 0.38 m?·cm2.

关键词： multi-conduction channels 2-D hole gas polarization-junction high-voltage low specific onresistance drain-induced barrier lowering effect

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Improved analysis of the rare decay processes of Λ_(b)

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Communications in Theoretical Physics 2021年第10期73卷 114-124页

作者： Ren-hao deng Yong-lu liu Ming-qiu Huang College of Art and Science National University of Defense TechnologyHunan 410073China

It is noted that in the new Particle Data Group(PDG) version the rare decays of the Λ_(b) baryon have been revised with more accuracy. The new results show that most of the existing theoretical results on the process Λ_(b)→Λ_(γ) Lgbare larger than those of experiments. With the improved higher-order light-cone distribution amplitudes of the Λ baryon, we reanalyze the process in the framework of light-cone quantum chromodynamics sum rules and the branching ratio is estimated to be Br (Λ_(b)→Λ_(γ))=(7.38-0.39+0.40)×10^(16), which is consistent with the new experimental result. Furthermore, another process Λ_(b)→Λl+l- is also analyzed in the same frame. The final branching ratio is calculated to be Br (Λ_(b)→Λl+l-)=1.20×10^(-6), which is in good accordance with the data from the PDG and other theoretical predictions.

关键词： light-cone distribution amplitude rare decay light-cone QCD sum rules

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Coupling framework for a wind speed forecasting model applied to wind energy

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Science China(Technological Sciences) 2022年第10期65卷 2462-2473页

作者： deng Ying CHONG KaiLeong WANG BoFu ZHOU Quan LU ZhiMing Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai 200072China

Wind energy is the burgeoning renewable energy. Accurate wind speed prediction is necessary to ensure the stability and reliability of the power grid for wind energy. This study focuses on developing a novel hybrid forecasting model to tackle adverse effects caused by strong variability and abrupt changes in wind speed. The hybrid model combines data decomposition and error correction strategy for a wind speed forecasting model applied to wind energy. First, wavelet packet decomposition is applied to wind speed series to obtain stationary subseries. Next, outlier robust extreme learning machine is implemented to predict subseries. Finally, an error correction strategy coupled with data decomposition is designed to repair preliminary prediction results. In addition, four measured datasets from China and USAwind farms with different time intervals are used to evaluate the performance of the proposed approach. Experimental analysis indicates that the proposed model outperforms the compared models. Results show that(1) the prediction accuracy of the proposed model is remarkably improved compared with other conventional models;(2) the proposed model can reduce the influence of the end effect in the decomposition-based forecasting model;(3) the coupling framework is successful for enhancing performance of hybrid forecasting model.

关键词： wind speed forecasting artificial intelligence hybrid model data preprocessing error correction wavelet packet decomposition

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Optimizing the Qusai-static Folding and Deploying of Thin-Walled Tube Flexure Hinges with Double Slots

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Chinese Journal of Mechanical Engineering 2014年第2期27卷 279-286页

作者： YANG Hui deng Zongquan liU Rongqiang WANG Yan GUO Hongwei State Key Laboratory of Robotics and System Harbin Institute of Technology

The thin-walled tube flexure（TWTF） hinges have important potential application value in the deployment mechanisms of satellite and solar array, but the optimal design of the TWTF hinges haven＇t been completely solved, which restricts their applications. An optimal design method for the qusai-static folding and deploying of TWTF hinges with double slots is presented based on the response surface theory. Firstly, the full factorial method is employed to design of the experiments. Then, the finite element models of the TWTF hinges with double slots are constructed to simulate the qusai-static folding and deploying non-linear analysis. What＇s more, the mathematical model of the TWTF flexure hinge quasi-static folding and deploying properties are derived by the response surface method. Considering of small mass and high stability, the peak moment of quasi-static folding and deploying as well as the lightless are set as the objectives to get the optimal performances. The relative errors of the objectives between the optimal design results and the FE analysis results are less than 7%, which demonstrates the precision of the surrogate models. Lastly, the parameter study shows that both the slots length and the slots width both have significant effects to the peak moment of quasi-static folding and deploying of TWTF hinges with double slots. However, the maximum Mises stress of quasi-static folding is more sensitive to the slots length than the slots width. The proposed research can be applied to optimize other thin-walled flexure hinges under quasi-static folding and deploying, which is of great importance to design of flexure hinges with high stability and low stress.

关键词： design optimization quasi-static folding and deploying flexure hinges thin-walled tube response surface method,numerical simulation

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Distributed sensor fault diagnosis for a formation system with unknown constant time delays

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Science China(Information Sciences) 2018年第11期61卷 128-143页

作者： Donghua ZHOU liguo QIN Xiao HE Rui YAN Ruiliang deng College of Electrical Engineering and Automation Shandong University of Science and Technology Department of Automation TNList Tsinghua University

In this paper, a distributed velocity sensor fault diagnosis scheme is presented for a formation of a second-order multi-agent system with unknown constant communication time delays. An existing distributed proportion-derivation(DPD) formation control law is adopted and a delay-independent condition is proposed to guarantee the asymptotical formation stability of the formation system based on the Nyquist stability criterion. Then a distributed fault diagnosis scheme is developed. In each agent, a distributed fault detection residual generator(DFDRG) and a bank of distributed fault isolation residual generators(DFIRGs) are designed based on the closed-loop model of the whole system. Each DFIRG is built up on the basis of a reduced-order unknown input observer(UIO) which is robust to the fault of one neighboring agent. According to the robust relationship between DFIRGs and faults, distributed fault isolation can be achieved. Conditions are presented to guarantee that each agent is able to diagnose faults of itself and its neighbors despite the disturbance of time delays. Finally, outdoor experimental results illustrate the effectiveness of the proposed schemes.

关键词： formation systems distributed fault diagnosis sensor faults time delays quadrotor unmanned helicopters

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钢精炼过程非金属夹杂物演变与控制

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金属学报 2022年第1期58卷 28-44页

作者：朱苗勇邓志银东北大学冶金学院沈阳110819

夹杂物控制是高品质特殊钢生产的难点和重点,本文介绍了钢中夹杂物的主要类型及其在精炼过程中的生成演变及去除行为规律,并结合作者的研究与实践,阐述了夹杂物控制的关键技术。钢中夹杂物类型与最初脱氧产物有较大的区别,其生成和演变... 详细信息

夹杂物控制是高品质特殊钢生产的难点和重点,本文介绍了钢中夹杂物的主要类型及其在精炼过程中的生成演变及去除行为规律,并结合作者的研究与实践,阐述了夹杂物控制的关键技术。钢中夹杂物类型与最初脱氧产物有较大的区别,其生成和演变与钢中的成分元素(如Ca、Mg和Ti等)密切相关,同一组成的夹杂物在钢中形态分布不同,最终会导致评级类别的差异。精炼过程中固态夹杂物通常比液态夹杂物更容易被去除,Al_(2)O_(3)和MgO·Al_(2)O_(3)夹杂物相比液态的CaO-Al_(2)O_(3)系夹杂物具有更高的去除效率。精炼渣、耐火材料以及钢包挂渣均会对钢中微量元素控制和夹杂物演变行为产生重要影响,适宜的渣碱度和稳定的造渣操作对夹杂物的控制非常重要。铝镇静钢的精炼渣碱度控制在4~7之间即可获得较好的脱氧效果;而硅锰镇静钢精炼渣采用变碱度操作并不利于夹杂物控制。同时,应该谨慎使用含CaO耐火材料。优质的洁净合金以及适宜的合金化时机,有助于控制钢中微量元素,减少合金中夹杂物的污染。精炼过程应避免过度搅拌,减弱对钢包挂渣的冲刷,并理性考虑夹杂物变性处理。控制钢中Ca含量、避免卷渣以及尽可能排除引流砂等手段有助于控制钢中的大型夹杂物。近年来的夹杂物演变和去除机理研究解释了诸多冶金过程现象,并提出了夹杂物控制新方向,但仍有如CaO-Al_(2)O_(3)夹杂物长大机制等机理需要进一步研究揭示,也亟待开发新的夹杂物控制技术来解决诸如如何彻底消除引流砂大型夹杂物等已知问题。

关键词：夹杂物钢精炼演变规律去除机理控制技术

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Perchlorate removal using granular activated carbon supported iron compounds: Synthesis, characterization and reactivity

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Journal of Environmental Sciences 2010年第11期22卷 1807-1813页

作者： Jianhong Xu Naiyun Gao Yulin Tang Yang deng Minhao Sui State Key Laboratory of Pollution Control and Resource Resue Tongji University Shanghai 200092 China Jiangxi University of Science and Technology Ganzhou 341000 China Department of Earth and Environmental Studies Montclair State University Montclair New Jersey 07043 USA

Synthesis and use of the iron compounds supported on granular activated carbon （ICs/GAC） have shown significant environmental implications for perchlorate （ClO4^- ） removal. ICs/GAC was synthesized via hydrolyzing FeSO 4 ·7H2O on GAC, reduced by NaBH 4 solution in polyethylene glycol 6000 and ethanol solution, dried in vacuum condition and exposed to air. Synthesized ICs/GAC was characterized using transmission electron micrograph （TEM）, Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy （XPS）. ICs/GAC was determined to be containing a large amount of FeOHSO 4 , Fe2O3 and a small amount of zero-valent iron （ZVI） nanoparticles according to TEM and XPS measurements. Batch static kinetic tests showed that 97% of ClO4^- was removed within 10 hr at 90°C and 86% of ClO4^- was removed within 12 hr at 25°C, at ICs/GAC dosage of 20 g/L. The experimental results also showed that FeOHSO 4 and Fe 2 O 3 nanoparticles have the function of perchlorate adsorption and play important roles in ClO4^- removal. The activation energy （E a ） was determined to be 9.56 kJ/mol.

关键词： perchlorate removal ICs /GAC activation energy synthesis

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Drilling Power Consumption and Soil Conveying Volume Performances of Lunar Sampling Auger

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Chinese Journal of Mechanical Engineering 2015年第3期28卷 451-459页

作者： TIAN Ye TANG Dewei deng Zongquan JIANG Shengyuan QUAN Qiquan State Key Laboratory of Robotics and System Harbin Institute of Technology University Research Center of Package Mechanical Design Harbin University of Commerce

The sampling auger used in lunar sampling and return mission is to transmit power and convey soil, and its performance is the key factor of the whole mission. However, there is currently a lack of the optimization research on soil conveying volume and power consumption models in auger structure design. To provide the drilled object, the simulation lunar soil, whose physical and mechanical property is the same as the real soil, is made by reducing soil void ratio. The models are formulated to analyze the influence of auger structure parameters on power consumption and soil conveying volume. To obtain the optimized structure parameters of auger, the multi-objective optimization functions of the maximum soil conveying volume and minimum power consumption are developed. To verify the correctness of the models, the performances of different augers drilling simulation soil are tested. The test results demonstrate that the power consumption of optimized auger is the lowest both in theory and test, and the experimental results of soil conveying volume are in agreement with theoretical analysis. Consequently, a new method for designing a lunar sampling auger is proposed which includes the models of soil conveying volume and transportation power consumption, the optimization of structure parameters and the comparison tests. This method provides a reference for sampling auger designing of the Chinese Lunar Sample Mission.

关键词： lunar sampling optimal design auger soil conveying volume model structure parameter

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Vascular Basement Membrane-derived Multifunctional Peptide,a Novel Inhibitor of Angiogenesis and Tumor Growth

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Acta Biochimica et Biophysica Sinica 2006年第7期38卷 514-521页

作者： Jian-Guo CAO~(1,2)Shu-Ping PENG~1 li SUN~2 Hui li~2 li WANG~2 Han-Wu deng~(1*) 1 Department of Pharmacology,School of Pharmaceutical Sciences,Central South University,Changsha 410078,China 2 Cancer Research Institute of Nanhua University,Hengyang 421001,China Department of Pharmacology School of Pharmaceutical Sciences Central South UniversityChangsha 410078 China Cancer Research Institute of Nanhua UniversityHengyang 421001 China

Vascular basement membrane-derived multifunctional peptide(VBMDMP)gene(fusion geneof the human immunoglobulin G3 upper hinge region and two tumstatin-derived fragments)obtained bychemical synthesis was cloned into vector pUC19,and introduced into the expression vector pGEX-4T-1 toconstruct a prokaryotic expression vector *** VBMDMP produced inEscherichia coli has been shown to have significant activity of antitumor growth and antimetastasis inLewis lung carcinoma transplanted into mouse C57B1/*** the present study,we have studied the ability ofrVBMDMP to inhibit endothelial cell tube formation and proliferation,to induce apoptosis in vitro,and tosuppress tumor growth in *** experimental results showed that rVBMDMP potently inhibited prolif-eration of human endothelial(HUVEC-12)cells and human colon cancer(SW480)cells in vitro,with noinhibition of proliferation in Chinese hamster ovary(CHO-K1)*** also significantly inhibitedhuman endothelial cell tube formation and suppressed tumor growth of SW480 cells in a mouse *** results suggest that rVBMDMP is a powerful therapeutic agent for suppressing angiogenesisand tumor growth.

关键词： recombinant vascular basement membrane-derived multifunctional peptide angiogenesis inhibitor therapeutic action

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Free-surface air entrainment in open-channel flows

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Science China(Technological Sciences) 2017年第6期60卷 893-901页

作者： WEI WangRu XU Weilin deng Jun TIAN Zhong ZHANG FaXing State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065 China

In hydraulic engineering,free-surface aeration is a natural phenomenon occurring in smooth channel *** self-aerated flows,a key aspect that has not yet been well understood is the formation mechanism of free-surface air *** this research,the process of free-surface entrapped deformation is analyzed theoretically and the critical radius of curvature for air entrainment is obtained,affected by flow mean velocity and *** the severity of local free-surface deformation exceeds the critical condition,the entrapped free surface encounters closure in the unstable deformation movement process,resulting in air *** inference agrees well with observed experimental results that are obtained from the processes of surface entrapped deformation and air entrainment captured by a high-speed camera-based data acquisition *** agreement indicates that self-aeration occurs in low-velocity open-channel *** is also confirmed that free-surface turbulent deformation provides a mechanism for air entrainment.

关键词： hydraulic engineering self-aeration turbulence free surface open-channel flows

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