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structures of a P4-ATPase lipid flippase in lipid bilayers

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Protein & Cell 2020年第6期11卷 458-463页

作者： Yilin He Jinkun Xu Xiaofei Wu Long Li State Key Laboratory of Membrane Biology Peking-Tsinghua Center for Life SciencesSchool of Life SciencesPeking UniversityBeijing 100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China

Dear Editor,Phospholipid molecules are unevenly distributed in membrane bilayers of eukaryotic cells.Phosphatidylethanolamine(PE)and phosphatidylserine(PS)are concentrated in the cytoplasmic leaflet,whereas phosphatidylcholine(PC)is enriched in the exoplasmic leaflet(lumenal or extracellular leaflet)(van Meer et al.2008).Type 4 P-type ATPases(P4-ATPases)are the phospholipid flippases which move specific lipids from the exoplasmic leaflet to the cytoplasmic leaflet.P4-ATPases belong to the P-type ATPase family.P4-ATPases are conserved in eukaryotes.

关键词： enriched concentrated structures

Development of hybrid optimization algorithm for structures furnished with seismic damper devices using the particle swarm optimization method and gravitational search algorithm

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Earthquake Engineering and Engineering Vibration 2022年第2期21卷 455-474页

作者： Najad Ayyash Farzad Hejazi Civil Engineering University Putra MalaysiaSeri Kembangan 43300Malaysia

Previous studies about optimizing earthquake structural energy dissipation systems indicated that most existing techniques employ merely one or a few parameters as design variables in the optimization process,and thereby are only applicable only to simple,single,or multiple degree-of-freedom structures.The current approaches to optimization procedures take a specific damper with its properties and observe the effect of applying time history data to the building;however,there are many different dampers and isolators that can be used.Furthermore,there is a lack of studies regarding the optimum location for various viscous and wall dampers.The main aim of this study is hybridization of the particle swarm optimization(PSO) and gravitational search algorithm(GSA) to optimize the performance of earthquake energy dissipation systems(i.e.,damper devices) simultaneously with optimizing the characteristics of the structure.Four types of structural dampers device are considered in this study:(ⅰ) variable stiffness bracing(VSB) system,(ⅱ) rubber wall damper(RWD),(ⅲ) nonlinear conical spring bracing(NCSB) device,(iv) and multi-action stiffener(MAS) device.Since many parameters may affect the design of seismic resistant structures,this study proposes a hybrid of PSO and GSA to develop a hybrid,multi-objective optimization method to resolve the aforementioned problems.The characteristics of the above-mentioned damper devices as well as the section size for structural beams and columns are considered as variables for development of the PSO-GSA optimization algorithm to minimize structural seismic response in terms of nodal displacement(in three directions) as well as plastic hinge formation in structural members simultaneously with the weight of the structure.After that,the optimization algorithm is implemented to identify the best position of the damper device in the structural frame to have the maximum effect and minimize the seismic structure response.To examine the performance of the proposed PSO-GSA optimization method,it h

关键词： hybrid optimization algorithm structures earthquake seismic damper devices particle swarm optimization method gravitational search algorithm

Moisture electricity generation:Mechanisms,structures,and applications

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Nano Research 2023年第5期16卷 7496-7510页

作者： Quanmao Wei Wenna Ge Zichao Yuan Shixu Wang Chenguang Lu Shile Feng Lei Zhao Yahua Liu Key Laboratory for Precision and Non-Traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116024China Key Laboratory of Icing and Anti/De-icing China Aerodynamics Research and Development CenterMianyang 621000China

With the increasing concern of energy crisis and global warming,the whole globe is in an urgent need to develop clean energy that comes from renewable sources and does not harm the environment to fulfill the carbon neutralization and green earth commitments.Water is the most abundant substance on earth and has been historically used as the major energy carriers in watermill,water wheel,hydroelectricity.Moisture electricity generation is another emerging technology that can convert lowgrade energy in the widely-accessible moisture to electricity simply by the integration of moisture,electrodes,deliberatelydesigned hygroscopic films.Recent research on moisture electricity generators(MEGs)led to the creation of a series of selfpowered sensors and in some occasions they have replaced conventional batteries to power miniaturized devices.In this review,the basic mechanisms of MEGs are firstly clarified,three categories of them,i.e.,gradient structure,homogeneous structure,and heterogeneous structure depending on the structure of hygroscopic films,are then introduced.Furthermore,recent advances in the fabrication,characteristics,performance of MEGs are summarized,MEGs with continuous or transient output that could be applied in self-powered sensors and power sources are discussed.Finally,some remaining challenges and our perspectives on MEGs are highlighted.

关键词： moisture hygroelectricity nanogenerators structures hygroscopic film

structures,stabilities,and magnetic properties of the Fe_nAu(n=1-12) clusters

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Chinese Physics B 2016年第6期25卷 179-190页

作者：吕瑾张江燕梁瑞瑞武海顺 School of Chemistry and Material Science Shanxi Normal University

The configurations,stabilities,electronic,and magnetic properties of FenAu（n = 1–12） clusters are investigated systematically by using the relativistic all-electron density functional theory with the generalized gradient approximation.The substitutional effects of Au in Fen＋1（n = 1,2,4,5,10–12） clusters are found in optimized structures which keep the similar frameworks with the most stable Fen＋1clusters.And the growth way for FenAu（n = 6–9） clusters is that the Au atom occupies a peripheral position of Fen cluster.The peaks appear respectively at n = 6 and 9 for Fen Au clusters and at n = 5 and 10 for Fen＋1clusters based on the size dependence of second-order difference of energy,implying that these clusters possess relatively high stabilities.The analysis of atomic net charge Q indicates that the charge always transfers from Fe to Au atom which causes the Au atom to be nearly non-magnetic,and the doped Au atom has little effect on the average magnetic moment of Fe atoms in Fen Au cluster.Finally,the total magnetic moment is reduced by 3 μB for each of Fen Au clusters except n = 3,11,and 12 compared with for corresponding pure Fen＋1 clusters.

关键词： alloy clusters structures electronic properties magnetism

Capillary-force-induced collapse lithography for controlled plasmonic nanogap structures

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Microsystems & Nanoengineering 2020年第1期6卷 404-412页

作者： Inki Kim Jungho Mun Wooseup Hwang Younghwan Yang Junsuk Rho Department of Mechanical Engineering Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Department of Chemistry Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea National Institute of Nanomaterials and Technology(NINT) Pohang 37673Republic of Korea

The capillary force effect is one of the most important fabrication parameters that must be considered at the micro/nanoscale because it is strong enough to deform micro/nanostructures.However,the deformation of micro/nanostructures due to such capillary forces(e.g.,stiction and collapse)has been regarded as an undesirable and uncontrollable obstacle to be avoided during fabrication.Here,we present a capillary-force-induced collapse lithography(CCL)technique,which exploits the capillary force to precisely control the collapse of micro/nanostructures.CCL uses electron-beam lithography,so nanopillars with various shapes can be fabricated by precisely controlling the capillary-force-dominant cohesion process and the nanopillar-geometry-dominant collapse process by adjusting the fabrication parameters such as the development time,electron dose,and shape of the nanopillars.CCL aims to achieve sub-10-nm plasmonic nanogap structures that promote extremely strong focusing of light.CCL is a simple and straightforward method to realize such nanogap structures that are needed for further research such as on plasmonic nanosensors.

关键词： capillary structures collapse

Inkjet printing-based fabrication of microscale 3D ice structures

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Microsystems & Nanoengineering 2020年第1期6卷 305-314页

作者： Fengyi Zheng Zhongyan Wang Jiasheng Huang Zhihong Li National Key Laboratory of Science and Technology on Micro/Nano Fabrication Institute of MicroelectronicsPeking UniversityBeijing 100871China

This study proposed a method for fabricating 3D microstructures of ice without a supporting material.The inkjet printing process was performed in a low humidity environment to precisely control the growth direction of the ice crystals.In the printing process,water droplets(volume=hundreds of picoliters)were deposited onto the previously formed ice structure,after which they immediately froze.Different 3D structures(maximum height=2000µm)could be formed by controlling the substrate temperature,ejection frequency and droplet size.The growth direction was dependent on the landing point of the droplet on the previously formed ice structure;thus,3D structures could be created with high degrees of freedom.

关键词： printing structures hundreds

Subwavelength hybrid plasmonic structures for nonlinear nanophotonics

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Light(Science & Applications) 2021年第3期10卷 307-309页

作者： Ann-Katrin U.Michel Optical Materials Engineering Laboratory Department of Mechanical and Process EngineeringETH ZurichZurichSwitzerland

Plasmonic structures made of a semiconductor-insulator-metal hybrid provide efficient routes for second-harmonic and sum-frequency generation in sub-micrometer structures,which ultimately may boost on-chip integrated ... 详细信息

关键词： structures nonlinear plasmon

Wafer-scale 3D shaping of high aspect ratio structures by multistep plasma etching and corner lithography

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Microsystems & Nanoengineering 2020年第1期6卷 1176-1186页

作者： Shu Ni Erwin J.W.Berenschot Pieter J.Westerik Meint Jde Boer Rene Wolf Hai Le-The Han J.G.E.Gardeniers Niels R.Tas Mesoscale Chemical System Group MESA+InstituteUniversity of Twente7522 NB EnschedeThe Netherlands Inorganic Materials Science Group MESA+InstituteUniversity of Twente7522 NB EnschedeThe Netherlands NanoLab Cleanroom MESA+InstituteUniversity of Twente7522 NB EnschedeThe Netherlands Physics of Fluids Group MESA+Institute&Max Planck Center for Complex Fluid DynamicsUniversity of Twente7522 NB EnschedeThe Netherlands BIOS Lab-on-a-Chip Group MESA+Institute&Max Planck Center for Complex Fluid DynamicsUniversity of Twente7522 NB EnschedeThe Netherlands

The current progress of system miniaturization relies extensively on the development of 3D machining techniques to increase the areal structure density.In this work,a wafer-scale out-of-plane 3D silicon(Si)shaping technology is reported,which combines a multistep plasma etching process with corner lithography.The multistep plasma etching procedure results in high aspect ratio structures with stacked semicircles etched deep into the sidewall and thereby introduces corners with a proper geometry for the subsequent corner lithography.Due to the geometrical contrast between the gaps and sidewall,residues are left only inside the gaps and form an inversion mask inside the semicircles.Using this mask,octahedra and donuts can be etched in a repeated manner into Si over the full wafer area,which demonstrates the potential of this technology for constructing high-density 3D structures with good dimensional control in the bulk of Si wafers.

关键词： lithography high structures

Effect of initial crystallization temperature and surface diffusion on formation of GaAs multiple concentric nanoring structures by droplet epitaxy

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Chinese Physics B 2020年第4期29卷 391-396页

作者：王一郭祥魏节敏杨晨罗子江王继红丁召 College of Big Data and Information Engineering Guizhou UniversityGuiyang 550025China Power Semiconductor Device Reliability Research Center of the Ministry of Education Guizhou UniversityGuiyang 550025China Key Laboratory of Micro-Nano-Electronics of Guizhou Province Guiyang 550025China School of Information Guizhou University of Finance and EconomicsGuiyang 550025China

GaAs multiple concentric nano-ring structures(CNRs)are prepared with multistep crystallization procedures by droplets epitaxy on GaAs(001)to explore the influence of different initial crystallization temperatures on CNRs morphology.Atomic force microscope(AFM)images show that GaAs nanostructures are more likely to form elliptical rings due to diffusion anisotropy.Meanwhile,with the increase of initial crystallization temperature,the inner ring height and density of CNRs are increased,and outer rings are harder to form.In addition,the mechanism of formation of CNRs is discussed by classical nucleation theory and diffusion theory.The method can be used to calculate the diffusion activation energy of gallium atoms(0.7±0.1 eV)on the GaAs(001)surface conveniently.

关键词： concentric nano-ring structures crystallization temperature activation energy of diffusion