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Lattice-distorted Pt wrinkled nanoparticles for highly effective hydrogen electrocatalysis

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Nano Research 2024年第5期17卷 3819-3826页

作者： Xue Li Xiang Han Zhenrui Yang Shun Wang Yun Yang Juan Wang Jiadong Chen Zhongwei Chen Huile Jin Wenzhou Key Lab of Advanced Energy Storage and Conversion Zhejiang Province Key Lab of Leather EngineeringCollege of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035China Institute of New Materials and Industry Technology College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035China Department of Chemical Engineering Waterloo Institute for NanotechnologyUniversity of WaterlooWaterlooOntario N2L 3G1Canada

Modulating Pt surfaces through the introduction of lattice distortion emerges as immensely effective strategy that enhances the kinetics of alkaline hydrogen evolution and oxidation processes.In this study,we fabricated lattice-distorted Pt wrinkled nanoparticles(LD-Pt WNPs)for efficient hydrogen electrocatalysis.The LD-Pt WNPs not only outperform the Pt/C benchmark in hydrogen oxidation reaction,achieving an excellent mass-specific current of 968.5 mA·mg_(Pt)^(-1)(9 times that of Pt/C),but also demonstrate outstanding hydrogen evolution reaction activity with a small overpotential of 58.0 mV.Comprehensive experiments and density functional theory calculations reveal that lattice defects introduce an abundance of unsaturated coordination atoms while modifying the d-band center of Pt.This dual effect optimizes the binding strength of crucial H and OH intermediates,leading to a significant reduction in the energy barrier of the reaction bottleneck,commonly known as the Volmer step.This work unveils a fresh viewpoint on projecting and developing high efficiency electrocatalysts through defect engineering.

关键词： distortion nanoparticle hydrogen evolution reaction defect engineering hydrogen oxidation reaction

Prediction and Minimization of the Heat Treatment Induced distortion in 8620H Steel Gear:Simulation and Experimental Verification

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Chinese Journal of Mechanical Engineering 2022年第6期35卷 207-218页

作者： Wen Shao Mohan Yi Jinyuan Tang Siyuan Sun State Key Laboratory of High Performance Complex Manufacturing College of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China

The considerable heat treatment induced runout value in the end face of the automobile main reducer gear is always dimensionally out of tolerance.It directly affects the dimensional accuracy,the grade of carburized and hardened gears,and the post-quenching manufacturing costs.In this study,three dimensional numerical models were developed to simulate the carburizing-quenching process of gear based on the multi-field coupling theory using DEFORM software.The results indicated that the ununiform cooling rate of the gear caused by the asymmetry of the web structure would result in the ununiform distribution of martensite,leading to the large runout value at the end face of the gear.Therefore,a novel method was proposed to minimize the heat treatment induced runout value.It was found that the heat treatment induced runout value could be effectively controlled by the addition of a compensation ring and the support of a rod structure.Further experiments showed that the average runout value of the gear end face before and after the proposed heat treatment method were about 0.023 mm and 0.059 mm respectively,which was in good agreement with the simulated results.The novel approach proposed in this study led to a reduction of the gear runout value by 70.0%‒76.9%compared to that of the original heat treatment process,which may serve as a practical and economical way to predict and minimize the heat treatment induced distortion in drive gear.

关键词： distortion Carburizing-quenching Numerical simulation Heat treatment 8620H steel gear

Intensity diffusion:a concealed cause of fringe distortion in fringe projection profilometry

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Photonics Research 2022年第5期10卷 1210-1222页

作者： ZHENG SUN MINGHUI DUAN YABING ZHENG YI JIN XIN FAN JINJIN ZHENG Department of Precision Machinery and Precision Instruments University of Science and Technology of ChinaHefei 230022China

Fringe projection profilometry(FPP)is widely used in optical three-dimensional(3D)measurements because of its high stability.In FPP,fringe distortion is an inevitable and highly complex systematic error that significantly reduces the 3D measurement accuracy.At this point,the existing causes of fringe distortion represented by gamma distortion,high-order harmonics,and image saturation have been effectively analyzed and compensated to restore high-quality fringe images.In this paper,we innovatively reveal a concealed cause of fringe distortion,i.e.,intensity diffusion across pixels,which is induced by photocarrier diffusion between photodiodes.To the best of our knowledge,intensity diffusion has not been studied in the field of fringe restoration.Based on the motion of photocarrier diffusion,we theoretically analyze the mechanism of how the intensity diffusion affects FPP.Subsequently,an intensity diffusion model is established for quantifying the diffused intensity in each pixel,and an intensity diffusion correction algorithm is presented to remove the diffused intensity from the fringe images and correct the fringe distortion.Experiments demonstrate the impact of intensity diffusion on FPP,and the 3D measurement results prove the effectiveness of the proposed methods on improving the 3D measurement accuracy by correcting the fringe distortion.

关键词： stability diffusion distortion

Depth distortion correction for consumer-grade depth cameras in crop reconstruction

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Information Processing in Agriculture 2023年第4期10卷 523-534页

作者： Cailian Lao Yu Feng Han Yang Key Laboratory of Modern Precision Agriculture System Integration Research Ministry of EducationChina Agricultural UniversityBeijing 100083PR China Key Laboratory of Agricultural Information Acquisition Technology Ministry of Agriculture and Rural AffairsChina Agricultural UniversityBeijing 100083PR China

Modern consumer-grade RGB-D cameras provide intensive depth estimation and high frame rates.They have been widely used in agriculture.However,depth anamorphose occurswhen using the RGB-D camera.In order to address this issue,this paper proposes a novel approach to correct the distorted depth images that fit the relationship between the true distances and the depth values from depth images.This study considers the structured light camera ASUS Xtion PRO LIVE as example to develop a system for obtaining a series of depth images at different distances from the target plane.A comparison analysis is conducted between the images before and after correction to evaluate the performance of the distortion correction.The point cloud image of corrected maize leaves is well coincident with the original plant.This approach improves the accuracy of depth measurement and optimizes the subsequent use of the depth camera in crop reconstruction and phenotyping studies.

关键词： RGB-D camera Structured light distortion Depth correction Point cloud

The push-pull principle:an electrostatic actuator concept for low distortion acoustic transducers

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Microsystems & Nanoengineering 2022年第6期8卷 181-194页

作者： Bert Kaiser Hermann A.G.Schenk Lutz Ehrig Franziska Wall Jorge M.Monsalve Sergiu Langa Michael Stolz Anton Melnikov Holger Conrad David Schuffenhauer Harald Schenk Fraunhofer Institute for Photonic Microsystems IPMS DresdenGermany Arioso Systems GmbH since Sep.1st 2022:BOSCH Sensortec GmbHDresdenGermany Chair of Micro and Nano Systems Brandenburg University of Technology Cottbus-SenftenbergCottbusGermany

Electrostatic actuators are of particular interest for microsystems(MEMS),and in particular for MEMS audio transducers for use in advanced true wireless applications.They are attractive because of their typically low electrical capacitance and because they can be fabricated from materials that are compatible with standard complementary metal-oxide semiconductor(CMOS)technology.For high audio performance and in particular low harmonic distortion(THD)the implementation of the push-pull principle provides strong benefits.With an arrangement of three electrodes in a conjunct moving configuration on a beam,we demonstrate here for the first time a balanced bending actuator incarnating the push-pull principle operating at low voltages.Our first design already exhibits a harmonic distortion as low as 1.2%at 79 dB using a signal voltage of only 6 V_(p) and a constant voltage of only±10 V_(dc) in a standard acoustic measurement setup.Thus,exceeding our previously reported approach in all three key performance indications at the same time.We expect that our novel electrode configurations will stimulate innovative electrostatic actuator developments for a broad range of applications.In this paper we report the basic theory,the fabrication and the performance of our novel actuator design acting as an audio transducer.

关键词： distortion push electrostatic

Defocused imaging-based quantification of plasmon-induced distortion of single emitter emission

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Light(Science & Applications) 2023年第10期12卷 2236-2247页

作者： Gwiyeong Moon Taehwang Son Hajun Yoo Changhun Lee Hyunwoong Lee Seongmin Im Donghyun Kim School of Electrical and Electronic Engineering Yonsei UniversitySeoul 03722Korea LG Innotek Seoul 07796South Korea Center for Systems Biology Massachusetts General HospitalBostonMAUSA LG Display PajuGyeonggi-do 10845South Korea

Optical properties of single emitters can be significantly improved through the interaction with plasmonic structures,leading to enhanced sensing and imaging capabilities.In turn,single emitters can act as sensitive probes of the local electromagnetic field surrounding plasmonic structures,furnishing fundamental insights into their physics and guiding the design of novel plasmonic devices.However,the interaction of emitters in the proximity to a plasmonic nanostructure causes distortion,which hinders precise estimation of position and polarization state and is one of the reasons why detection and quantification of molecular processes yet remain fundamentally challenging in this era of super-resolution.Here,we investigate axially defocused images of a single fluorescent emitter near metallic nanostructure,which encode emitter positions and can be acquired in the far-field with high sensitivity,while analyzing the images with pattern matching algorithm to explore emitter-localized surface plasmon interaction and retrieve information regarding emitter positions.Significant distortion in defocused images of fluorescent beads and quantum dots near nanostructure was observed and analyzed by pattern matching and finite-difference time-domain methods,which revealed that the distortion arises from the emitter interaction with nanostructure.Pattern matching algorithm was also adopted to estimate the lateral positions of a dipole that models an emitter utilizing the distorted defocused images and achieved improvement by more than 3 times over conventional diffraction-limited localization methods.The improvement by defocused imaging is expected to provide a way of enhancing reliability when using plasmonic nanostructure and diversifying strategies for various imaging and sensing modalities.

关键词： distortion matching interaction

Analysis and application of the acoustic interfered field distortion for acoustic forward-scattering detection of underwater targets

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Chinese Journal of Acoustics 2022年第2期41卷 99-115页

作者： HE Chuanlin ZHENG Yi MA Yuanliang Institute of Oceanographic Instrumentation Qilu University of Technology(Shandong Academy of Sciences)Qingdao 266100 School of Ocean Technology Sciences Qilu University of Technology(Shandong Academy of Sciences)Qingdao 266100 School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072

The signal-to-direct-blast ratio SDRF in acoustic forward-scattering detection can measure the relative magnitudes of the forward scattered wave and the direct-blast,but it does not consider the interference and superimposition effects between the two waves.These two waves inevitably interfere with one another and are difficult to distinguish,so it is difficult to directly apply SDRF in target detection and analysis.Based on SDRF and considering the interference between the forward scattered wave and the direct-blast,a new parameter called the acoustic interfered field distortion ΔFTL is developed,and the corresponding calculation formula is deduced.Compared with SDRF,ΔFTL can be obtained directly from data and has the advantage of not relying on prior information to a certain extent.The following is found according to this formula in combination with data from the Qiandao Lake scaled-target detection experiment.(1) Estimating the geometric expansion loss coefficient reveals that the acoustic wave propagates spherically,which is consistent with the simulation results of the ray model based on the measured hydrological parameters.(2) The relation between ΔFTL and the target crossing position is quantitatively confirmed,confirming the effectiveness of the ΔFTL formula.(3) A performance evaluation scheme independent of prior information is established for direct-blast suppression and then applied to an adaptive direct-blast suppression method.The influences of acoustic leakage and disturbances in the attitude angle of the target on the results can be ignored.These results show that ΔFTL can effectively replace SDR_(F),providing theoretical references for conducting performance evaluations on acoustic forward-scattering detection and direct-blast suppression.

关键词： distortion scattered underwater

Genome-wide dissection of segregation distortion using multiple inter-subspecific crosses in rice

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Science China(Life Sciences) 2019年第4期62卷 507-516页

作者： Guangwei Li Jiye Jin Yan Zhou Xufeng Bai Donghai Mao Cong Tan Gongwei Wang Yidan Ouyang National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan) Huazhong Agricultural University

Mendelian inheritance can ensure equal segregation of alleles from parents to offspring, which provides fundamental basis for genetics and molecular biology. Segregation distortion(SD) leads to preferential transmission of certain alleles from generation to generation. Such violation of Mendelian genetic principle is often accompanied by reproductive isolation and eventually speciation. Although SD is observed in a wide range of species from plants to animals, genome-wide dissection of such biased transmission of gametes is rare. Using nine inter-subspecific rice crosses, a genome-wide screen for SD loci is performed, which reveals 61 single-locus quantitative trait loci and 194 digenic interactions showing distorted transmission ratio, among which 24 new SD loci are identified. Biased transmission of alleles is observed in all nine crosses, suggesting that SD exists extensively in rice populations. 72.13% distorted regions are repeatedly detected in multiple populations, and the most prevalent SD hotspot that observed in eight populations is mapped to chromosome 3. Xian alleles are transmitted at higher frequencies than geng alleles in inter-subspecific crosses, which change the genetic composition of the rice populations. Epistatic interaction contributes significantly to the deviation of Mendelian segregation at the whole-genome level in rice, which is distinct from that in animals. These results provide an extensive archive for investigating the genetic basis of SD in rice, which have significant implications in understanding the reproductive isolation and formation of inter-subspecific barriers during the evolution.

关键词： Oryza sativa,xian/indica geng/japonica segregation distortion reproductive isolation allele frequency

distortion THEOREM FOR BIHOLOMORPHIC MAPPINGS IN TRANSITIVE DOMAINS(Ⅱ)

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Chinese Annals of Mathematics,Series B 1992年第4期13卷 471-484页

作者：郑学安龚昇 Department of Mathematics Anhui University Hefei Anhui 230039 China. Department of Mathematics University of Science and Technology of China Hefei Anhui 230026 China.

Based on [1], this paper gives concrete estimates for distortion theorem for biholomorphic convex mappings in classical domains of types Ⅰ, Ⅱ, and Ⅲ including transitive domains which are holomorphically homeomorph... 详细信息

关键词： convex distortion estimates normalized invariant 二尹 kernel satisfy verify Domain