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Behavior of fractional quantum Hall states in LLL and 1LL with in-plane magnetic field and Landau level mixing:A numerical investigation

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Chinese Physics B 2018年第8期27卷 492-497页

作者： lin-Peng Yang Qi Li zi-Xiang Hu Department of Physics Chongqing UniversityChongqing 401331China

By exactly solving the effective two-body interaction for a two-dimensional electron system with layer thickness and an in-plane magnetic field, we recently found that the effective interaction can be described by the generalized pseudopoten- tials （PPs） without the rotational symmetry. With this pseudopotential description, we numerically investigate the behavior of the fractional quantum Hall （FQH） states both in the lowest Landau level （LLL） and first excited Landau level （1LL）. The enhancements of the 7/3 FQH state on the 1LL for a small tilted magnetic field are observed when layer thickness is larger than some critical values, while the gap of the 1/3 state in the LLL monotonically reduced with increasing the in-plane field. From the static structure factor calculation, we find that the systems are strongly anisotropic and finally enter into a stripe phase with a large tilting. With considering the Landau level mixing correction on the two-body interaction, we find the strong LL mixing cancels the enhancements of the FQH states in the 1LL.

关键词： fractional quantum Hall in-plane magnetic field pseudopotentials Landau level mixing

Modelling and analysis of half-/full-bridge hybrid MMC when riding through DC-side pole-to-ground fault

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High Voltage 2022年第3期7卷 496-509页

作者： Zhen He Jiabing Hu Lei lin Pingliang zeng School of Automation Hangzhou Dianzi UniversityHangzhouChina State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhanChina

In a modular multilevel converter-based high-voltage direct current(MMC-HVDC)system,the dc fault ride through(FRT)control is an effective way to deal with a dc-side pole-to-ground(PTG)***,the setting of FRT duration brings potential hazards:1)MMC will face the risk of“secondary short circuit”if FRT duration is short;2)ac grid may have power angle stability issue if FRT duration is *** avoid these hazards and provide theoretical guidance for the FRT duration setting,transient behaviour of dc fault current during the PTG FRT stage is explored in this ***,challenges of the transient analysis are summarised as non-linearity and high-order *** light of this,numerical and Hilbert-Huang Transformation methods are introduced to evaluate the non-linearity *** is found that the path of MMC from dc current to dc internal voltage is weakly ***,a linear transient model is built to analyse the dc fault *** participation factor analysis,the order of the proposed model is further reduced,so that an analytical expression of the dc fault current is approximately *** on the analytical expression,regularities and mechanism of dc fault current are fully *** of the transient analysis to the setting of FRT duration is elaborated in ***,the PSCAD/EMTDC simulation verifies the validity of the proposed model and analytical expression.

关键词： fault ground setting

Janus MXene film with gradient structure for highly efficient terahertz and infrared electromagnetic absorption

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Nano Research 2025年第1期18卷 434-442页

作者： Shaodian Yang Weiqiang Huang Zhiqiang lin zibo Chen Rongliang Yang Yi Jia Xuebin Liu Rui Wang Zhiping zeng Yougen Hu Huanjun Chen Xuchun Gui11 State Key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou 510275China National Key Laboratory of Materials for Integrated Circuits Shenzhen Institute of Advanced Electronic MaterialsShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China China Academy of Aerospace Science and Innovation Beijing 100176China Guangdong Province Key Laboratory of Display Material and Technology Guangzhou 510275China School of Materials Science and Engineering Sun Yat-sen UniversityGuangzhou 510275China

Electromagnetic interference (EMI) shielding inhigh-frequency range, especially the rapidly growing terahertz(THz) frequency range, attracts increasing attention due tothe potential application of terahertz in 6G wirelesscommunication, and security inspection. However, traditionalconductive EMI films typically achieve high shieldingeffectiveness through strong reflection, which may causesecondary pollution to other devices. Here, a gradientstructure strategy was proposed to constructTi_(3)C_(2)Tx/hydroxypropyl methyl cellulose (HPMC) film, in whichthe content of Ti_(3)C_(2)Tx gradually increases along the thicknessdirection, resulting in different conductivity of the two surfaces(surface-M and surface-H) for the film. The obtained gradientfilmexhibits an EMI shielding efficiency of over 48.5 dB in theTHz range (0.2-1.6 THz) at a thickness of 40 μm. Especially,as the THz waves incident from the surface-H to the film, the absorption effectiveness reaches 48.2 dB (average absorbedpower loss up to 91.4%), and the reflection effectiveness is only 0.3 dB. In additions, the gradient-film also demonstrates ahigh absorption rate of 95.5% in the infrared band (2.5-16.7 μm). Moreover, the gradient-film exhibits an excellent tensilestress and Young’s modulus value of 173.1 MPa and 2.8 GPa, respectively. Therefore, the gradient-film proposed in thiswork, with excellent electromagnetic absorption in both THz and infrared band, provides a promising candidate for the nextgenerationEMI shielding applications.

关键词： electromagnetic interference shielding Janus film terahertz MXene

Electrodeposited highly-oriented bismuth microparticles for efficient CO_(2)electroreduction into formate

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Nano Research 2022年第12期15卷 10078-10083页

作者： Chen lin Yan Liu Xiangdong Kong Zhigang Geng Jie zeng University of Science and Technology of China Hefei230026China

Bi is one of the most fascinating catalysts for the formation of HCOO-towards CO_(2)***,we developed electrodeposited angular-shaped Bi microparticles(Bi MP)with exposed surfaces of{003}and{101}planes as efficient catalyst for the electroreduction of CO_(2)into HCOO-.During CO_(2)electroreduction,Bi MP achieved a Faraday efficiency(FE)for HCOO-of higher than 95%over a wide range of applied potential from-0.6 to-1.1 V versus reversible hydrogen electrode(***),whereas the FE for HCOO-of Bi nanoflakes(Bi NF)with exposed surfaces of{104}and{110}planes was around 70%.At-1.1 V ***,the partial current density for HCOO-of Bi MP was-271.7 mA·cm-2,1.56 times as high as that of Bi *** to kinetic analysis and mechanistic study,highly-oriented surface of Bi MP not only facilitated Faradaic process and accelerated reaction kinetics via enhancing the CO_(2)activation,but also restrained competing hydrogen evolution reaction,thus boosting catalytic performance of the electroreduction of CO_(2)into HCOO-.

关键词： electrodeposited Bi formate product highly-oriented bismuth surface CO_(2)electroreduction

The Formation and Characterization of GaN Hexagonal Pyramids

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Chinese Physics Letters 2013年第5期30卷 116-119页

作者： ZHANG Shi-Ying XIU Xiang-Qian lin zeng-Qin HUA Xue-Mei XIE zi-Li ZHANG Rong ZHENG You-Dou Key Laboratory of Advanced Photonic and Electronic Materials School of Electronic Science and EngineeringNanjing UniversityNanjing 210093

GaN with hexagonal pyramids is fabricated using the photo-assisted electroless chemical etching *** areas of the GaN substrate are selectively etched in a mixed solution of KOH and K2S2O8 under ultraviolet illumination,producing submicron-sized *** pyramids on the etched GaN with well-defined{1011}facets and very sharp tips are ***-resolution x-ray diffraction shows that etched GaN with pyramids has a higher crystal quality,and micro-Raman spectra reveal a tensile stress relaxation in GaN with pyramids compared with normal *** cathodoluminescence intensity of GaN after etching is significantly increased by three times,which is attributed to the reduction in the internal reflection,high-quality GaN with pyramids and the Bragg effect.

关键词： pyramid illumination ultraviolet

Post-evaluation of a water pollution control plan： methodology and case study

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Frontiers of Environmental Science & Engineering 2015年第4期9卷 712-724页

作者： lin zeng Xin DONG Siyu zeng Tianzhu ZHANG Jing LI Jining CHEN School of Environment Tsinghua University Beijing 100084 China

China has developed more than 20 water pollution control plans for river basins （RBWPs） since 1996. However, the implementation has generally lagged. This paper proposes a three-step, post-evaluation methodology to analyze the implementation result of a RBWP and its influential factors. First, a multi-attribute evaluation method based on an index system is established to score the enforcement results of a RBWP. Indicators measure how well a RBWP has achieved its objectives, which include water quality compliance, pollution load control, project construction, financial inputs, and related management requirements. Second, an interpretive structural model is used to detect the significant factors that affect RBWP implementation. This model can effectively analyze the cause-effect chain and hierarchical relationship among variables. Five groups of factors were identified, namely, plan preparation, water resource endowment, policy, institution, and management. Both qualitative and quantitative methods are employed in the third step to evaluate the extent to which these factors have influenced the execution result of a RBWP, including pre-post contrast, scenario analysis, and correlation analysis. This research then post-evaluated the implementation of the Huai River Basin water pollution control plans （H-RBWPs） over a period of 10 years as a case study. Results showed that the implementation of the H-RBWPs was unsatisfactory during 2001–2005, although it improved during 2006–2010. The poor execution of these plans was partially caused by the underestimation of regional economic development in combination with ineffective industrial structure adjustment policies. Therefore, this case study demonstrates the feasibility and flexibility of the proposed post-evaluation methodology.

关键词： river basin water pollution control plan postplan evaluation multi-attribute comprehensive evaluation,interpretive structural model combined qualitative/quantitative method

Mechanical performance of 22SiMn2TiB steel welded with lowtransformation- temperature filler wire and stainless steel filler wire

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Journal of Iron and Steel Research International 2024年第4期31卷 967-981页

作者： zi-dong lin Kai-jie Song Zhen Sun zi-qian Zhu Xue-feng Zhao Constantinos Goulas Wei Ya Xing-hua Yu School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China Department of Design Production and Management Faculty of Engineering Technology.University of TwenteEnschede 7500 AETheNetherlands Rotterdam Additive Manufacture Fieldlab(RAMLAB) Rotterdam 3089 JWTheNetherlands

TX-80 low-transformation-temperature(LTT)welding wire was used to replace the traditional ER 307Si welding wire to realize the connection of 22SiMn2TiB armor steel in manual overlay *** previously existing issues,such as welding cracks,large welding deformation,and severe welding residual stress,were solved to ensure good strength and ductility *** particular,with the same welding conditions,TX-80 LTT wire eliminates welding *** reduces the welding deformation no matter the base pretreatment of pre-setting angle or no pre-setting *** comparison,it was found that the microstructure at the TX-80 weld is mainly composed of martensite and a small amount of retained *** contrast,the microstructure of the ER 307Si weld consists of a large amount of austenite and a small amount of skeleton-like *** variation trend of residual stress and microhardness from the weld to the base were investigated and compared with the mechanical properties of base *** TX-80 and the ER 307Si tensile samples elongation is 6.76%and 6.01%,while the ultimate tensile strengths are 877 and 667 MPa,*** average impact toughness at room temperature of the ER 307Si weld is 143.9 J/cm^(2),much higher than that of the TX-80 weld,which is only 36.7 J/cm^(2).The relationship between impact and tensile properties with microstructure species and distribution was *** addition,the fracture surface of the tensile and the impact samples was observed and *** dimples,fewer pores,larger radiation zone,and shear lips of TX-80 samples indicate better tensile ductility and worse impact toughness than those of ER 307Si weld.

关键词： Low-transformation-temperature material 22SiMn2TiB steel Welding deformation Residual stress Martensitic transformation Mechanical property

Neutrophil extracellular traps in gastrointestinal cancer

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World Journal of Gastroenterology 2021年第33期27卷 5474-5487页

作者： zi-Qiang Chu Ke-Cheng Zhang lin Chen Graduate School Chinese PLA General HospitalBeijing 100853China Institute of Basic Medical Sciences Chinese PLA General HospitalBeijing 100853China Department of General Surgery Chinese PLA General Hospital First Medical CenterBeijing 100853China

Gastrointestinal(GI)cancer is a high-risk malignancy and is characterized by high mortality and morbidity *** extracellular traps(NETs),a weblike structure consisting of chromatin DNA with interspersed cytoplasmic and granule proteins,are extruded by activated neutrophils to entrap and kill bacteria and ***,accumulating evidence shows that NETs are related to the progression and metastasis of *** clinical studies,NETs infiltrate primary GI cancer tissues and are even more abundant in metastatic *** quantity of NETs in peripheral blood is revealed to be associated with ascending clinical tumour stages,indicating the role of NETs as a prognostic markers in GI ***,several inhibitors of NETs or NET-related proteins have been discovered and used to exert anti-tumour effects in vitro or in vivo,suggesting that NETs can be regarded as targets in the treatment of GI *** this review,we will focus on the role of NETs in gastric cancer and colorectal cancer,generalizing their effects on tumour-related thrombosis,invasion and *** reports are also listed to show the latest evidences of how NETs affect GI ***,notwithstanding the scarcity of systematic studies elucidating the underlying mechanisms of the interaction between NETs and cancer cells,we highlight the potential importance of NETs as biomarkers and anti-tumour therapeutic targets.

关键词： Neutrophil extracellular traps Gastric cancer Colorectal cancer Biomarkers Therapeutic targets

Corrosion resistance and superhydrophobicity of one-step polypropylene coating on anodized AZ31 Mg alloy

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Journal of Magnesium and Alloys 2021年第4期9卷 1452-1466页

作者： Zhao-Qi Zhang Li Wang Mei-Qi zeng Rong-Chang zeng Cun-Guo lin Zhen-lin Wang Dong-Chu Chen Qiang Zhang Corrosion Laboratory for Light Metals College of Material Science and EngineeringShandong University of Science and TechnologyQingdao 266590China State Key Laboratory for Marine Corrosion and Protection Luoyang Ship Material Research InstituteQingdao 266101China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450002China College of Materials Science and Engineering Chongqing University of TechnologyChongqing 400065China School of Materials Science and Energy Engineering Foshan UniversityFoshan 528000China

Superhydrophobic coatings have been considerably used in corrosion and its protection of metallic *** the comprehensive performance(hydrophobicity,bonding strength,and corrosion resistance,etc.)of the top coating may be highly dependent on the physical and chemical properties of the primer or under ***,an integrated superhydrophobic polypropylene(PP)coating was fabricated on the micro-arc oxidized Mg substrate via one-step *** morphologies and chemical compositions of the composite coating were examined through Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),and field-emission scanning electron microscopy(FESEM)together with X-ray photoelectron spectroscopy(XPS).The surface wettability of the coating was determined by contact angle and sliding *** corrosion-resistant performance was evaluated via electrochemical and immersion *** results showed that the hybrid coating possessed micron-scaled granular structure on the surface with a high water contact angle of 167.2±0.8°and a low water sliding angle of 2.7±0.5°.The corrosion resistance of superhydrophobic coating was obviously enhanced with a low corrosion current density of 8.76×10^(−9)A/cm^(2),and the coating still maintained integrity after 248 h of immersion in 3.5wt%NaCl aqueous *** MAO coating provides better adhesion of PP to the ***,the superhydrophobic coating exhibited superior bonding strength,corrosion resistance and durability.

关键词： Magnesium alloy Corrosion resistance Superhydrophobicity Bonding strength Polymer coating