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Electron Transport Properties of Graphene-Based Quantum Wires

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Communications in Theoretical Physics 2018年第12期69卷 829-833页

作者： Hua Zhao Xiao-Wei Zhang Xiao-Chun liu Yong Zheng wan-guo liu School of Physics and Electronics Qiannan Normal University for Nationalities

We study the electronic transport in quantum wire structures made of graphene. By using the nonequilibrium Green function method, the transmission is studied for varies sizes samples. Our results show that the transmission sensitive depends on the size of the system and exhibits fluctuations due to the mismating of propagating modes between the central region and the leads. The number of resonant transmission peaks increases with the increase of length of the wire, while the width of the leads mainly affect the transmission in the region of low energy. A central energy gap in the transmission spectrum is more likely to appear in the quantum wire system than in the uniform armchair graphene nanoribbons. Moreover, the energy gap can be widened for a certain size of the quantum wire system by changing the width of the leads. These results may have potential applications in designing graphene-based devices.

关键词： graphene quantum wire transmission

Synthesis and Herbicidal Activity of Novel Sulfonylureas Containing Thiadiazol Moiety

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Chemical Research in Chinese Universities 2008年第1期24卷 32-35页

作者： guo wan-cheng liu Xing-hai LI Yong-hong wanG Su-hua LI Zheng-ming Institute of Elemento-Organic Chemistry State Key Laboratory of Elemento-Organic Chemistry Nankai University Tianjin 300071 P. R. China

Thirteen novel sulfonylureas containing thiadiazole moiety were synthesized in a two-step reaction. Their structures were determined using IR, ^1H NMR, HRFTMS, and elemental analysis. Herbicidal activities of these compounds were determined in the green house bio-assay. The results show that four compounds among them exhibit some activity toward four tested herbs.

关键词： Sulfonylurea Synthesis Herbicidal activity

Light People:*** May Lau,newly elected US NAE member in Hong Kong,talks about future of photonics and women in science

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Light(Science & Applications) 2024年第4期13卷 602-608页

作者： Yating wan Chenzi guo Electrical and Computer Engineering the ComputerElectrical and Mathematical Sciences and Engineering DivisionKing Abdullah University of Science and Technology23955-6900 ThuwalSaudi Arabia Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchunChina

Editorial Photonics technology remains a driving force in today’s scientific landscape,marked by continuous innovation and crossdisciplinary *** an enlighting conversation with Light:Science&Applications,*** May Lau,a pioneer in photonics research,shares her deep insights on the evolution of technologies of LEDs,lasers,challenges of hetero-epitaxy,and the future of micro-LEDs and quantum dot *** honored as a member of the US National Academy of Engineering(NAE)for her significant contributions to photonics and electronics using III-V semiconductors on silicon,*** stands out as the sole Hong Kong scholar inducted into the NAE this year,joining 114 new and 21 international *** this exclusive Light People interview,*** shares her journey as a pioneering woman in engineering,her commitment to mentorship and academia,and her perspective on advancing female representation in *** summary provided is distilled from ***’s thoughtful responses during the *** a deeper exploration of ***’s experiences and advice,the full interview is available in the Supplementary material.

关键词： interview lighting driving

Harnessing data using symbolic regression methods for discovering novel paradigms in physics

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 1-11页

作者： Jianyang guo wan-Jian Yin College of Energy Soochow Institute for Energy and Materials Innovations(SIEMIS)Jiangsu Provincial Key Laboratory for Advanced Carbon Materials and Wearable Energy TechnologiesSoochow UniversitySuzhou 215006China Shanghai Qi Zhi Institute Shanghai 200232China Light Industry Institute of Electrochemical Power Sources Soochow UniversitySuzhou 215006China

In recent years,machine-learning methods have profoundly impacted research in the interdisciplinary fields of ***,most machine-learning models lack interpretability,and physicists doubt the credibility of their conclusions because they cannot be combined with prior physical ***,this review focuses on symbolic regression,which is an interpretable machine-learning ***,the relevant concepts of machine learning are introduced in conjunction with ***,we provide an overview of symbolic regression ***,the recent directions for the application of symbolic regression methods in different subfields of physics are outlined,and an overview of the ways in which the applications of symbolic regression have evolved in the realm of physics is *** major aim of this review is to introduce the basic principles of symbolic regression and explain its applications in the field of physics.

关键词： machine learning genetic programming symbolic regression

Critical role of carbon support in metal nanoaggregate facilitating Fe-N-C catalyst for PEM fuel cell application

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Journal of Energy Chemistry 2024年第10期97卷 669-676页

作者： Liming guo Xin wan Qingtao liu Xiaofang liu Jiaxiang Shang Ronghai Yu Jianglan Shui School of Materials Science and Engineering Beihang University Tianmushan Laboratory

Metal nanoaggregates can simultaneously enhance the activity and stability of Fe-N-C catalysts in proton-exchange-membrane fuel cells（PEMFC）.Previous studies on the relevant mechanism have focused on the direct interaction between FeN4active sites and metal ***,the role of carbon support that hosts metal nanoaggregates and active sites has been ***,a Fe-N-C catalyst encapsulating inactive gold nanoparticles is prepared as a model catalyst to investigate the electronic tuning of Au nanoparticles（NPs） towards the carbon *** NPs donate electrons to carbon support,making it rich in π electrons,which reduces the work function and regulates the electronic configuration of the FeN4sites for an enhanced ORR ***,the electron-rich carbon support can mitigate the electron depletion of FeN4sites caused by carbon support oxidation,thereby preserving its high *** yield and accumulation of H2O2are thus alleviated,which delays the oxidation of the catalyst and benefits the *** to the electron-rich carbon support,the composite catalyst achieves a top-level peak power density of 0.74 W/cm2in a 1.5 bar H2-air PEMFC,as well as the improved *** work elucidates the key role of carbon support in the performance enhancement of the FeN-C/metal nanoaggregate composite catalysts for fuel cell application.

关键词： Carbon support Fe-N-C Fuel cells Hetero-structure catalyst Oxygen reduction reaction

Optimal regularity of positive solutions of the Hénon-Hardy equation and related equations

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Science China Mathematics 2024年第10期67卷 2283-2302页

作者： Zongming guo Fangshu wan College of Mathematics and Information Science Henan Normal University School of Mathematical Sciences University of Science and Technology of China School of Mathematical Sciences Anhui University

We present a new method to determine the optimal regularity of positive solutions u∈C4（Ω{0}）∩C0■ of the Hénon-Hardy equation,i.e.,■ where Ω■RN（N≥4） is a bounded smooth domain with 0∈Ω,α>-4,and p∈*** is clear that 0 is an isolated singular point of solutions of（0.1） and the optimal regularity of u in Ω relies on the parameter α.It is also important to see that the regularity of u at x=0 determines the regularity of u in Ω.We first establish asymptotic expansions up to arbitrary orders at x=0 of prescribed positive solutions u ∈C4（Ω{0}） ∩ C0（Ω）of（0.1）.Then we show that the regularity at x=0 of each positive solution u of（0.1） can be determined by some terms in asymptotic expansions of the related positive radial solution of the equation（0.1） with Ω=B,where B is the unit ball of *** main idea works for more general equations with singular weights.

关键词： Hénon-Hardy equation positive solutions optimal regularity singular point asymptotic expansions

Vibration Control of A Flexible Marine Riser System Subject to Input Dead Zone and Extraneous Disturbances

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China Ocean Engineering 2024年第2期38卷 271-284页

作者： ZHOU Li wanG guo-rong wan Min School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China Energy Equipment Institute Southwest Petroleum UniversityChengdu 610500China National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China

An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental *** control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control ***,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each *** direction interference observers are designed to track the timevarying boundary *** this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead *** addition,the stability of the closed-loop system is proven by Lyapunov stability *** the system states are bounded,and the vibration offset of the riser converges to a small area of the initial ***,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.

关键词： adaptive backstepping control disturbance observer flexible marine riser input dead zone vibration control

Integration of morphology and electronic structure modulation on cobalt phosphide nanosheets to boost photocatalytic hydrogen evolution from ammonia borane hydrolysis

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Green Energy & Environment 2024年第2期9卷 333-343页

作者： Chao wan Yu Liang liu Zhou Jindou Huang Jiapei wang Fengqiu Chen Xiaoli Zhan Dang-guo Cheng School of Chemistry and Chemical Engineering Anhui Province Key Laboratory of Coal Clean Conversion and High Valued UtilizationAnhui University of TechnologyMa'anshan243002China College of Chemical and Biological Engineering Zhejiang UniversityZhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology38 Zheda RoadHangzhou310027China Key Laboratory of New Energy and Rare Earth Resource Utilization of State Ethnic Affairs Commission Key Laboratory of Photosensitive Materials&Devices of Liaoning ProvinceSchool of Physics and Materials EngineeringDalian Nationalities University 18 Liaohe West RoadDalian116600China Institute of Zhejiang University-Quzhou 78 Jiuhua Boulevard NorthQuzhou324000China Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology Changzhou University213164China

The controllable and safe hydrogen storage technologies are widely recognized as the main bottleneck for the accomplishment of sustainable hydrogen *** borane(AB)has regarded as a competitive candidate for chemical hydrogen ***,developing efficient yet high-performance catalysts towards hydrogen evolution from AB hydrolysis remains an enormous ***,cobalt phosphide nanosheets are synthesized by a facile salt-assisted along with low-temperature phosphidation strategy for simultaneously modulating its morphology and electronic structure,and function as hydrogen evolution ***,the Co_(2)P nanosheets display extraordinary performance with a record high turnover frequency of 44.9 min^(-1),outperforming most of the noble-metal-free catalysts reported to *** remarkable performance is attributed to its desired nanosheets structure,featuring with high specific surface area,abundant exposed active sites,and short charge diffusion *** findings provide a novel strategy for regulating metal phosphides with desired phase structure and morphology for energy-related applications and beyond.

关键词： Ammonia borane Hydrogen generation Hydrolysis Cobalt phosphide nanosheets Photocatalysis

Adverse effect of niobium and boron on hot deformation behavior of sulfur-containing steel

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Journal of Iron and Steel Research International 2024年第1期31卷 252-263页

作者： guo-ning He Shi-qi wan Bo Jiang Chao-lei Zhang Ya-zheng liu Chun-jing Wu School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing100083China

The hot deformation behaviors of sulfur-containing gear steel 20MnCr5 containing three different contents of Nb and B(0,0.021%Nb,and 0.024%Nb-0.0022%B)were *** compression and tenssion tests were carried out by Gleeble3800 at the austenite region from 850 to 1150℃and the adverse effects of Nb and B were analyzed by the fracture,microstructure and precipitate *** compression tests showed that the proportions of instable area in hot processing maps of 0.021%Nb and Nb-B steels were higher and the deformability of Nb free steel was *** tensile deformation experiments showed that the reduction areas of Nb free,0.021%Nb and Nb-B steels were 92%-99%,84%-98%and 67%-97%,*** addition of Nb or Nb and B inhibited the dynamic recrystallization during hot deformation,and consequently,more deformed grains were then formed in 0.021%Nb and Nb-B steels thus to obtain the microstructure with worse uniformity and then deteriorate the *** addition,the interaction between inclusions and microalloyed elements was also *** particles of 0.021%Nb and Nb-B steels dynamically precipitated during deformation and precipitated together with MnS thus to worsen the deformability,resulting in the decrease of reduction area.

关键词： Hot deformation Gear steel Processing map Dynamic recrystallization Microalloying