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Overcoming the limitations of gallium oxide through heterogeneous integration

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Science China(Physics,Mechanics & Astronomy) 2021年第1期64卷 118-119页

作者： yuhao zhang Kevin JChen Center for Power Electronics Systems Virginia Polytechnic and State UniversityBlacksburgVA24060USA Departmnet of Electronic and Computer Engineering The Hong Kong University of Science and TechnologyHong KongChina

Power electronics,processing over 50%of world's electric energy,enables very efficient electric energy conversion for a wide range of applications such as electric vehicles,data centers,autonomous driving,robotics and smart *** availability of low-cost,efficient,and reliable power semiconductor devices that can conduct high current,block high voltage,and switch at high frequencies are key to improving the performance of power electronics systems.

关键词： integration enable autonomous

Energy-efficient resource allocation for hybrid bursty services in multi-relay OFDM networks

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Science China(Information Sciences) 2017年第10期60卷 169-186页

作者： yuhao zhang Qimei CUI Ning WANG Yanzhao HOU Weiliang XIE School of Information and Communication Engineering Beijing University of Posts and Telecommunications China Telecom Corporation Limited

In this paper, we propose mapped two-way water filling(MTWF) scheme to maximize energy efficiency(EE) for hybrid bursty services with quality of services(Qo S) requirements in two-way multirelay(TWMR) OFDM networks. The bursty traffic is first analyzed by strictly proved equivalent homogeneous Poisson process, based on which the Qo S requirements are converted into sum-rate constraints. The formulated non-convex EE maximization problem, including subcarrier assignment, relay selection(RS) and rate allocation, is NP-hard involving combinatorial optimization. To conduct optimal RS on each subcarrier without priori bursty traffic knowledge, we utilize some approximate relationships under high data rate demands to remove its dependence on two-way data rates, and simplify the whole optimization problem as well. After the optimal channel configuration is obtained, which only depends on channel conditions, subcarrier assignment is attained through elitist selection genetic algorithm(ESGA), and rate allocation of each service is fulfilled by deducing two-way water filling principle. A new equivalent optimization objective function is proposed next as the simple evaluating index in ESGA to reduce complexity. Finally, simulations are carried out to verify the superiority and convergence of our scheme, as well as the applicability for different scenarios.

关键词： energy efficiency resource allocation hybrid bursty services two-way multi-relay genetic algorithm

Constructing an artificial short route for cell-free biosynthesis of the phenethylisoquinoline scaffold

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Synthetic and Systems Biotechnology 2023年第4期8卷 610-617页

作者： yuhao zhang Wan-Qiu Liu Jian Li School of Physical Science and Technology ShanghaiTech UniversityShanghai201210China

Plant-originated natural products are important drug ***,total biosynthesis of these compounds is often not achievable due to their uncharacterized,lengthy biosynthetic *** nature,phenethylisoquinoline alkaloids(PIAs)such as colchicine are biosynthesized via a common precursor 6,7-dihydroxy-1-(4-hydroxyphenylethyl)-1,2,3,4-tetrahydroisoquinoline(i.e.,phenethylisoquinoline scaffold,PIAS).PIAS is naturally synthesized in plants by using two upstream substrates(L-phenylalanine and L-tyrosine)catalyzed by eight *** shorten this native pathway,here we designed an artificial route to synthesize PIAS with two enzymatic steps from two alternative substrates of 3-(4-hydroxyphenyl)propanol(4-HPP)and *** the two-step bioconversion,an alcohol dehydrogenase selected from yeast(i.e.,ADH7)was able to oxidize its non-native alcohol substrate 4-HPP to form the corresponding aldehyde product,which was then condensed with dopamine by the(S)-norcoclaurine synthase(NCS)to synthesize *** optimization,the final enzymatic reaction system was successfully scaled up by 200 times from 50μL to 10 mL,generating 5.4 mM of *** envision that this study will provide an easy and sustainable approach to produce PIAS and thus lay the foundation for large-scale production of PIAS-derived natural products.

关键词： Phenethylisoquinoline scaffold Artificial pathway Cell-free biosynthesis Natural product

Experimental study of primary and secondary side coupling natural convection heat transfer characteristics of the passive residual heat removal system in AP1000

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Frontiers in Energy 2021年第4期15卷 860-871页

作者： Zhimin QIU Daogang LU Jingpin FU Li FENG yuhao zhang School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy Beijing 102206China

Passive residual heat removal heat exchanger(PRHR HX),which is a newly designed equipment in the advanced reactors of AP1000 and CAP1400,plays an important role in critical accidental *** primary and secondary side coupling heat transfer characteristics of the passive residual heat removal system(PRHRS)determine the capacity to remove core decay heat during the ***,it is necessary to investigate the heat transfer characteristics and develop applicable heat transfer formulas for optimized *** the present paper,an overall scaled-down natural circulation loop of PRHRS in AP1000,which comprises a scaleddown in-containment refueling water storage tank(IRWST)and PRHR HX models and a simulator of the reactor core,is built to simulate the natural circulation process in residual heat removal accidents.A series of experiments are conducted to study thermal-hydraulic behaviors in both sides of the miniaturized PRHR HX which is simulated by 12 symmetric arranged C-shape *** the local PRHR HX heat transfer performance,traditional natural convection correlations for both the horizontal and vertical bundles are compared with the experimental data to validate their applicability for the specific heat transfer ***,the revised natural convection heat transfer correlations based on the present experimental data are developed for PRHR HX vertical and lower horizontal *** paper provides essential references for the PRHRS operation and further optimized design.

关键词： passive residual heat removal heat exchanger(PRHR HX) C-shape tube revised heat transfer correlations coupled natural convection*

A Knowledge-Enriched and Span-Based Network for Joint Entity and Relation Extraction

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Computers, Materials & Continua 2021年第7期68卷 377-389页

作者： Kun Ding Shanshan Liu yuhao zhang Hui zhang Xiaoxiong zhang Tongtong Wu Xiaolei Zhou The Sixty-Third Research Institute National University of Defense TechnologyNanjing210007China School of Computer Science and Technology Southeast UniversityNanjing211189China Faculty of Information Technology Monash UniversityMelbourne3800Australia

The joint extraction of entities and their relations from certain texts plays a significant role in most natural language *** entity and relation extraction in a specific domain,we propose a hybrid neural framework consisting of two parts:a span-based model and a graph-based *** span-based model can tackle overlapping problems compared with BILOU methods,whereas the graph-based model treats relation prediction as graph *** main contribution is to incorporate external lexical and syntactic knowledge of a specific domain,such as domain dictionaries and dependency structures from texts,into end-to-end neural *** conducted extensive experiments on a Chinese military entity and relation extraction *** results show that the proposed framework outperforms the baselines with better performance in terms of entity and relation *** proposed method provides insight into problems with the joint extraction of entities and their relations.

关键词： Entity recognition relation extraction dependency parsing 1 Introduction

Blue light-emitting polyfluorenes containing dibenzothiophene-S,S-dioxide unit in alkyl side chain

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Science China Chemistry 2017年第10期60卷 1356-1366页

作者： Yiwen Fang Jie Liu yuhao zhang Ting Guo Fei Huang Wei Yang Yong Cao Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 China

Blue light-emitting polyfluorenes containing dibenzothiophene-S,S-dioxide(SO) unit in alkyl side chain(PF-FSOs and PF-CzSOs) were synthesized. All the polymers show high thermal stability with the decomposition temperatures over400 °C. The highest occupied molecular orbital(HOMO) and the lowest unoccupied molecular orbital(LUMO) energy levels of the copolymer slightly decrease with the increase of SO content in side chain. PL spectra of the polymers show slightly red shift and broadening with the increase of solvent polarities, indicating unremarkable intramolecular charge transfer(ICT) effect in the polymers containing SO unit in alkyl side chain. EL spectra of the polymers are almost unchanged in the current densities from 100 to 400 mA cm.2, indicating the superb EL stability of the resulted polymers. The EL spectra of the copolymers exhibit obvious blue-shift and narrowing with the CIE of(0.18, 0.11) for PF-FSO10 and(0.17, 0.11) for PF-CzSO10, respectively,compared with PF-SO10 containing SO unit in main chain with the CIE of(0.16, 0.17) and PFO with the CIE of(0.18, 0.18).The superior device performances were obtained with the luminous efficiency(LEmax) of 1.17 and 0.68 cd A.1 for PF-FSO15 and PF-CzSO20, respectively, compared with the LEmax of 0.37 cd A.1 for PFO. The results indicate that linking SO unit to alkyl side chain of the polyfluorene is a promising strategy for efficient blue light-emitting polymers.

关键词： dibenzothiophene-S S-dioxide alkyl side chain polyfluorene blue emission polymer light-emitting diode(PLED)

Control of crystal growth to obtain needle-shaped violet phosphorus with excellent photocatalytic degradation performance

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Nano Research 2023年第2期16卷 3320-3325页

作者： Mengting Jin Yanhao Wang Mengyue Gu Xuewen Zhao Rongzheng Zhao yuhao zhang Yonghong Cheng Jinying zhang School of Electrical Engineering Xi’an Jiaotong UniversityXi’an 710049China

The control of crystal growth is important but challenging for multi-disciplinary *** phosphorus,the most stable phosphorus allotrope,has recently been produced as a unique semiconducting layered *** crystal orientation and morphology bring extra performance due to its unique structure and ***,the layered violet phosphorus has been controlled to grow along the c-axis to give tunable length up to centimeters with the assistance of tin,while the reported flat bulk ones with thickness are limited to *** as-produced needle-shaped violet phosphorus has also been demonstrated to significantly enhance the photocatalytic degradation of methyl orange pollutants due to its special crystallographic *** 98.6%of methyl orange pollutants with a concentration of 50 ppm were degraded within 80 min under visible light conditions by needle-shaped violet phosphorus,which is much more effective than that of amorphous red phosphorus with only 14.1%degradation.

关键词： crystal growth photocatalytic degradation red phosphorus tin violet phosphorus

Nanodiamonds decorated yolk-shell ZnFe_(2)O_(4) sphere as magnetically separable and recyclable composite for boosting antibiotic degradation performance

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Chinese Journal of Chemical Engineering 2023年第2期54卷 162-172页

作者： Jingjing Pan Haoran Sun Keyi Chen yuhao zhang Pengnian Shan Weilong Shi Feng Guo School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212003China School of Material Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China College of Chemistry Zhengzhou UniversityZhengzhou 450001China

Photocatalysis is an environmentally friendly and energy-saving technology, which can effectively remove persistent dangerous pollutants in the water. Pitifully, optical absorption capacity and carrier separation have become major bottlenecks for marvelous photocatalytic performance of ***, to address these issue, Nanodiamonds/yolk-shell ZnFe_(2)O_(4) spheres(NDs/ZFO) nanocomposites were successfully constructed via a facile two-step of solvothermal and calcination methods. The synthesized optimal NDs/ZFO-10 nanocomposite exhibits superior photocatalytic degradation activity of antibiotic under visible light, approximately 85% of the total tetracycline(TC) is degraded, and this photocatalyst shows durable cycling stability. This stems from two aspects of refinement: improvement of light absorption capacity and photo-induced charges migration and separation. In addition, the NDs/ZFO composite photocatalyst features excellent magnetic recovery capability, facilitating the recovery of photocatalyst in industry. This study opens a new chapter in the combination of NDs with magnetic materials, and deepens the understanding of the application of NDs modified composite photocatalysts.

关键词： Nanodiamonds ZnFe_(2)O_(4) Photocatalytic Heterojunction Antibiotic degradation

Recent progress in preventive effect of collagen peptides on photoaging skin and action mechanism

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Food Science and Human Wellness 2022年第2期11卷 218-229页

作者： Chongyang Li Yu Fu Hongjie Dai Qiang Wang Ruichang Gao yuhao zhang Key Laboratory of Luminescent and Real-Time Analytical Chemistry Ministry of EducationCollege of Food ScienceSouthwest UniversityChongqing 400715China Biological Science Research Center Southwest UniversityChongqing 400715China Institute of Food Science and Technology Chinese Academy of Agriculture Sciences/Key Laboratory of Agro-Products ProcessingMinistry of Agriculture and Rural AffairsBeijing 100193China School of Food and Biological Engineering Jiangsu UniversityZhenjiang 212013China

Ultraviolet(UV)-induced photoaging skin has become an urgent *** functional foods and cosmetics aiming to improve skin photoaging are developing rapidly,and the demand is gradually increasing year by *** peptides have been proven to display diverse physiological activities,such as excellent moisture retention activity,hygroscopicity,tyrosinase inhibitory activity and antioxidant activity,which indicates that they have great potential in amelioration of UV-induced *** main objective of this article is to recap the main mechanisms to improve photoaging skin by collagen peptides and their physiological activities in ***,the extraction and structural characteristics of collagen peptides are *** importantly,some clinical trials on the beneficial effect on skin of collagen peptides are also *** addition,prospects and challenges of collagen peptides are emphatically elucidated in this *** article implies that collagen peptides have great potential as an effective ingredient in food and cosmetics industry with a wide application prospect.

关键词： Collagen peptides Photoprotection MAPK TGF-β-Smad Action mechanism