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Defects as a factor limiting carrier mobility in WSe2： A spectroscopic investigation

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Nano Research 2016年第12期9卷 3622-3631页

作者： zhangting wu Zhongzhong Luo Yuting Shen Weiwei Zhao Wenhui Wang Haiyan Nan Xitao Guo Litao Sun Xinran Wang Yumeng You Zhenhua Ni Department of Physics andJiangsu Key Laboratory forAdvanced Metallic Materials Southeast University Nanjing 211189 China National Laboratory of Solid State Microstructure School of Electronic Science and Engineering National Center of Microstructures and Quantum Manipulation Nanjing University Nanjing 210093 China SEU-FEI Nano-Pico Center Key Laboratory of MEMS of the Ministry of Education Southeast University Nanjing 210095 China Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments School of Mechanical Engineering Southeast University Nanjing 211189 China Ordered Matter Science Research Center Southeast University Nanjing 211189 China

The electrical performance of two-dimensional transition metal dichalcogenides （TMDs） is strongly affected by the number of structural defects. In this work, we provide an optical spectroscopic characterization approach to correlate the number of structural defects and the electrical performance of WSe2 devices. Low-temperature photoluminescence （PL） spectra of electron-beam-lithography- processed WSe2 exhibit a clear defect-induced PL emission due to excitons bound to defects, which would strongly degrade the electrical performance. By adopting an electron-beam-free transfer-electrode technique, we successfully prepared a backgated WSe2 device containing a limited amount of defects. A maximum hole mobility of approximately 200 cm2.V -1.s-1 was achieved because of the reduced scattering sources, which is the highest reported value for this type of device. This work provides not only a versatile and nondestructive method to monitor the defects in TMDs but also a new route to approach the room-temperature phonon-limited mobility in high-performance TMD devices.

关键词： two-dimensional materials tungsten diselenide structural defects photoluminescencespectroscopy mobility

Thickness-dependent enhanced optoelectronic performance of surface charge transfer-doped ReS2 photodetectors

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Nano Research 2022年第4期15卷 3638-3646页

作者： Peiyu Zeng Wenhui Wang Jie Jiang Zheng Liu Dongshuang Han Shuojie Hu Jiaoyan He Peng Zheng Hui Zheng Liang Zheng Xiaojing Yao Weitao Su Dexuan Huo zhangting wu Zhenhua Ni Yang Zhang Lab for Nanoelectronics and NanoDevices Department of Electronics Science and TechnologyHangzhou Dianzi UniversityHangzhou 310018China School of Physics Southeast UniversityNanjing 211189China Jiangsu Province Special Equipment Safety Supervision and Inspection Institute Wuxi 214170China School of Sciences Hangzhou Dianzi UniversityHangzhou 310018China College of Physics and Hebei Advanced Thin Film Laboratory Hebei Normal UniversityShijiazhuang 050024China Institute of Materials Physics Hangzhou Dianzi UniversityHangzhou 310018China

Surface charge transfer doping has been widely utilized to tune the electronic and optical properties of semiconductor photodetectors based on low-dimensional *** many studies have been conducted on the performance(response time,responsivity,etc.)of doped photodetectors and their mechanisms,they merely examined a specific thickness and did not systematically explore the dependence of doping effects on the number of *** work performs a series of investigations on ReS_(2)photodetectors with different numbers of layers and demonstrates that the p-dopant tetrafluorotetracyanoquinodimethane(F_(4)-TCNQ)converts the deep trap states into recombination centers for few-layer ReS_(2)and induces a vertical p-n junction for thicker ReS_(2).A response time of 200 ms is observed in the decorated 2-layer ReS_(2)photodetector,more than two orders of magnitude faster than the response of the pristine photodetector,due to the disappearance of deep trap states.A current rectification ratio of 30 in the F_(4)-TCNQ-decorated sandwiched ReS_(2)device demonstrates the formation of a vertical p-n junction in a thicker ReS_(2)*** responsivity is as high as 2,000 A/W owing to the strong carrier separation of the p-n *** thicknesses of ReS_(2)enable switching of the prominent operating mechanism between transforming deep trap states into recombination centers and forming a vertical p-n *** thicknessdependent doping effect of a two-dimensional material serves as a new mechanism and provides a scheme toward improving the performance of other semiconductor devices,especially optical and electronic devices based on low-dimensional materials.

关键词： Surface charge transfer doping ReS_(2) thickness response time responsivity tetrafluorotetracyanoquinodimethane(F_(4)-TCNQ)

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二维过渡金属硫属化合物的激光发射

激光与光电子学进展 2017年第4期54卷 41-50页

作者：郑婷南海燕吴章婷倪振华东南大学物理系江苏南京211189

以二硫化钼(MoS_2)为代表的二维过渡金属硫属化合物(TMDs)具有随厚度/层数变化的光学和电学性质,并且展示出独特的激子效应和较高的光学量子产率,在光电子器件中具有很好的应用前景。近年来,基于TMDs材料的光学性质和光电子器件的研究... 详细信息

以二硫化钼(MoS_2)为代表的二维过渡金属硫属化合物(TMDs)具有随厚度/层数变化的光学和电学性质,并且展示出独特的激子效应和较高的光学量子产率,在光电子器件中具有很好的应用前景。近年来,基于TMDs材料的光学性质和光电子器件的研究进展迅速,如通过电场、化学掺杂、缺陷等方式实现了对其光致发光(PL)的调控,并极大地提高了PL发射量子产率;基于TMDs边带异质结和垂直异质结的LEDs被广泛研究并获得了较高的光发射效率;以TMDs作为增益介质,并将其与微盘、光子晶体空腔等耦合实现了低阈值激光发射。从TMDs的结构和光学性质出发,总结了TMDs材料PL的调控手段及效果,并介绍TMDs中激光发射的研究进展,最后对基于TMDs的激光发展进行了展望。

关键词：材料激光过渡金属硫属化合物荧光

Quantitative impacts of meteorology and emissions on the long-term trend of O3 in the Yangtze River Delta(YRD),China from 2015 to 2022

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Journal of Environmental Sciences 2025年第3期149卷 314-329页

作者： Lingxia wu Junlin An Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration Nanjing University of Information Science and TechnologyNanjing 210044China

Extensive spatiotemporal analyses of long-trend surface ozone in the Yangtze River Delta(YRD)region and itsmeteorology-related and emission-related have not been systematically *** this study,by using 8-year-long(2015–2022)surface ozone observation data,we attempted to reveal the variation ofmultiple timescale components using the Kolmogorov–Zurbenko filter,and the effects of meteorology and emissions were quantitatively isolated using multiple linear regression with meteorological *** results showed that the short-term,seasonal,and long-term components accounted for daily maximum 8-hr average O_(3)(O_(3–8)hr)concentration,46.4%,45.9%,and 1.0%,*** meteorological impacts account for an average of 71.8%of O_(3–8)hr,and the YRD’s eastern and northern sections aremeteorology-sensitive *** on statistical analysis technology with empirical orthogonal function,the contribution of meteorology,local emission,and transport in the long-term component of O_(3–8)hr were 0.21%,0.12%,and 0.6%,*** spatiotemporal analysis indicated that a distinct decreasing spatial pattern could be observed from coastal cities towards the northwest,influenced by the monsoon and synoptic *** central urban agglomeration north and south of the YRD was particularly susceptible to local *** the cities studied,Shanghai,Anqing,and Xuancheng,located at similar latitudes,were significantly impacted by atmospheric transmission—the contribution of Shanghai,the maximum accounting for 3.6%.

关键词： O_(3)Yangtze River Delta(YRD)Kolmogorov-Zurbenko filter Empirical orthogonal function Long-term trend

Effect of chlorination and ultraviolet on the adsorption of pefloxacin on polystyrene and polyvinyl chloride

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Journal of Environmental Sciences 2025年第3期149卷 21-34页

作者： Yanan Li Yaning wu Kai Guo Weiqin wu Meijing Yao School of Environmental Science and Engineering Taiyuan University of TechnologyShanxi 030600China

During thewater treatment process,chlorination and ultraviolet(UV)sterilization can modify microplastics(MPs)and alter their physicochemical properties,causing various changes between MPs and other *** this study,the impact of chlorination and UV modification on the physicochemical properties of polystyrene(PS)and polyvinyl chloride(PVC)were investigated,and the adsorption behavior of pefloxacin(PEF)before and after modificationwas *** effect of pH,ionic strength,dissolved organicmatter,heavymetal ions and other water environmental conditions on adsorption behavior was *** results showed that PS had a higher adsorption capacity of PEF than PVC,and the modification increased the presence of O-containing functional groups in the MPs,thereby enhancing the adsorption capacity of both *** had a more significant impact on the physicochemical properties of MPs compared to UV irradiation within the same time period,leading to better adsorption performance of *** optimal pH for adsorption was found to be 6,and NaCl,sodium alginate and Cu2+would inhibit adsorption to varying degrees,among which the inhibition caused by pH was the *** and UV modification would weaken the inhibitory effect of environmental factors on the adsorption of PEF by *** main mechanisms of adsorption involved electrostatic interaction and hydrogen *** study clarified the effects of modification on the physicochemical properties of MPs,providing reference for subsequent biotoxicity analysis and environmental protection studies.

关键词： Microplastics Chlorination Ultraviolet Pefloxacin Adsorption mechanism

Parametric Analysis and Designing Maps for Powder Spreading in Metal Additive Manufacturing

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Computer Modeling in Engineering & Sciences 2025年第2期142卷 2067-2090页

作者： Yuxuan wu Sirish Namilae Department of Aerospace Engineering Embry-Riddle Aeronautical UniversityDaytona BeachFL 32114USA

Powder bed fusion(PBF)in metallic additive manufacturing offers the ability to produce intricate geometries,high-strength components,and reliable ***,powder processing before energy-based binding significantly impacts the final product’s *** maps guide efficient process design to minimize defects,but creating them through experimentation alone is challenging due to the wide range of parameters,necessitating a comprehensive computational parametric *** this study,we used the discrete element method to parametrically analyze the powder processing design space in PBF of stainless steel 316L *** lattice parameter sweeps are often used for parametric analysis,but are computationally *** find that non-uniform parameter sweep based on the low discrepancy sequence(LDS)algorithm is ten times more efficient at exploring the design space while accurately capturing the relationship between powder flow dynamics and bed packing *** introduce a multi-layer perceptron(MLP)model to interpolate parametric causalities within the LDS parameter *** over 99%accuracy,it effectively captures these causalities while requiring fewer ***,we generate processing design maps for machine setups and powder selections for efficient process *** find that recoating speed has the highest impact on powder processing quality,followed by recoating layer thickness,particle size,and inter-particle friction.

关键词： Powder bed fusion additive manufacturing discrete element method parameter sweep process design

The Impact of Different Effective Models for Star Formation on the Properties of Simulated Milky Way-sized Galaxies

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Research in Astronomy and Astrophysics 2025年第1期25卷 194-210页

作者： Yiheng wu Volker Springel Shanghai Astronomical Observatory Chinese Academy of Sciences University of Chinese Academy of Sciences Max-Planck-Institut für Astrophysik

Hydrodynamical cosmological simulations of galaxy formation such as Illustris TNG or Auriga have shown considerable success in approximately matching many galaxy properties,but their treatment of the star-forming interstellar medium (ISM) has relied on heuristic sub-grid ***,recent high-resolution simulations of the ISM that directly resolve the regulation of star formation suggest different mean relations for the dependences of pressure and star formation rate on the average gas *** this study,we adopt such a modern,physically grounded parameterization inspired by the TIGRESS small-scale *** dub this model TEQS and use it for a detailed comparative analysis of the formation and evolution of a Milky Way-sized galaxy when compared with the widely used TNG *** employing high-resolution simulations in tall box setups,we first investigate the structural differences expected for these two models when applied to different self-gravitating gas surface *** results indicate that TEQS produces considerably thinner gaseous layers and can be expected to form stellar distributions with smaller scale-height than TNG,especially at higher surface *** test whether this induces systematic structural differences in cosmological galaxy formation simulations,we carry out zoom-in simulations of 12 galaxies taken from the set of Milky Way-sized galaxies that have been studied in the Auriga *** results for these galaxies shows that disk galaxies formed with the TEQS model have on average very similar stellar mass but are more concentrated in their central regions and exhibit smaller stellar radii compared to those formed with the TNG *** differences in the scale-heights of the formed stellar disks are only marginal,however,suggesting that other factors for setting the thickness of the disk are more important than the applied ISM equation-of-state ***,the predicted galaxy structure is quite similar for TNG and

关键词： Galaxy: evolution Galaxy: formation methods: numerical

Obesogenic effects of six classes of emerging contaminants

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Journal of Environmental Sciences 2025年第5期151卷 252-272页

作者： Siying wu Chaoyu Tong Jing Liu MOE Key Laboratory of Environmental Remediation and Ecosystem Health College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China

There is growing concern about the concept that exposure to environmental chemicals may be contributing to the obesity ***,there is no consensus on the obesogenic effects of emerging contaminants from a toxicological and environmental *** potential human exposure and experimental evidence for obesogenic effects of emerging contaminants need to be systematically *** main objective of this review is to provide recommendations for further subsequent policy development following a critical analysis of the literature for humans and experimental animals exposed to emerging *** article reviews human exposure to emerging contaminants(with a focus on antimicrobials,preservatives,water and oil repellents,flame retardants,antibiotics and bisphenols)and the impact of emerging contaminants on *** emerging contaminants have been widely detected in human biological *** studies provide evidence linking exposure to emerging contaminants to the risks of obesity in *** based on animalmodels and adipose cells show the obesogenic effects of emerging contaminants and identify modes of action by which contaminants may induce changes in body fat accumulation and lipid metabolic *** knowledge gaps in this area and future directions for further investigation are discussed.

关键词： Emerging contaminants Obesity Human exposure Preservatives Flame retardants Plasticizers Antibiotics

Tectonic modes of mantle convection and their implications for Earth's tectonic evolution based on three-dimensional numerical simulations

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Science China Earth Sciences 2025年第1期68卷 270-296页

作者： Song XIANG Jinshui HUANG Bingcheng wu School of Earth and Space Sciences University of Science and Technology of ChinaHefei230026China CAS Center of Excellence in Comparative Planetary Studies Hefei230026China

Five tectonic modes of mantle convection are obtained and analyzed with three-dimensional numerical models in a spherical shell *** five tectonic convective modes are non-plate mobile-lid,plate-like mobile-lid,episodic plate-like mobile-lid,episodic stagnant-lid,and stagnant-lid convective modes,*** typical characteristics of these five tectonic modes and their numerical classification criteria based on plateness,mobility,and their standard deviations are presented and *** results show that the yield stress of the lithosphere has profound effects on the tectonic convective *** the gradual increase of yield stress,the tectonic mode of mantle convection changes from one to another sequentially through the aforementioned five ***,as the Rayleigh number increases,the range of yield stress for the platelike mobile-lid convective mode decreases,and the dimensionless transition stress between different tectonic modes ***,the dimensional transition stress between the non-plate mobile-lid convective mode and plate-like mobile-lid convective mode increases with the increase of Rayleigh number,but decreases between other tectonic ***,we find that the transition stress between different tectonic modes is inversely proportional to the internal heating rate,with the transition stress decreasing as the internal heating rate *** fitting analysis of the transition stress between tectonic modes shows that Earth's current plate tectonics correspond to a lithospheric yield stress of 150–250 MPa,which aligns with the strength of serpentinized mantle rock determined by experimental *** the Archean mantle was 300℃warmer than it is today,then the Earth was in an episodic stagnant-lid convective *** tectonic evolution of the Earth's surface is closely related to the lithospheric strength and the process of thermal *** the lithospheric strength was only 150 MPa,plate tecton

关键词： Tectonic mode of mantle convection Plate-like mobile-lid convection Episodic plate-like mobile-lid convection Episodic stagnant-lid convection Plate tectonics and tectonic evolution of the Earth