It is of great significance to develop a high-efficiency and low-noise propeller optimization method for new-generation propeller aircraft design.Coupled with free form deformation method,dynamic mesh interpolation te...It is of great significance to develop a high-efficiency and low-noise propeller optimization method for new-generation propeller aircraft design.Coupled with free form deformation method,dynamic mesh interpolation technology,optimization algorithm,surrogate model,aerodynamic calculation and aeroacoustic prediction model module,the integrated aerodynamic and aeroacoustic design method of propeller is built.The optimization design for the six-blade propeller is carried out.The non-reduction in efficiency,thrust coefficient and the minimum of aerodynamic noise is treated as the optimization design objective.The spatial vorticity distribution of the propeller before and after the design is also analyzed by using unsteady computational fluid dynamics method.The results show that the optimized propeller can effectively reduce the aerodynamic noise level.The maximum total sound pressure level can be reduced by 5 dB without reducing its aerodynamic performance.The developed method has good application potential in low-noise optimization design of propeller and other rotating machinery.展开更多
The structure of protein and peptide at interfaces plays a crucial role in various biological processes and technological advancements.Understanding these structures is critical for diagnosing diseases,drug delivery,a...The structure of protein and peptide at interfaces plays a crucial role in various biological processes and technological advancements.Understanding these structures is critical for diagnosing diseases,drug delivery,and developing biomaterials.However,the complexity of these systems and limitations in analytical tools have hindered the in-depth exploration.Despite significant efforts in determining protein structures using advanced techniques like X-ray crystallography and cryo-electron microscopy,the understanding of surface-bound protein structures in real conditions remains relatively limited,posing a current challenge in this field.Vibrational sum frequency generation(SFG)spectroscopy has been developed as a versatile method for elucidating molecular structures of proteins across interfaces.This review is intended to introduce the basic principle of SFG spectroscopy,discuss its current advancements in phase measurement,and showcase recent examples(2021-2023)illustrating SFG’s ability in revealing the molecular structure of peptides and proteins at interfaces.This concise review aims to establish a foundation for future studies and applications exploring different types of peptides and proteins at interfaces using SFG.展开更多
The strategic introduction of defects in polyoxometalate-based metal–organic frameworks(POM@MOFs)enables synergistic catalytic effects between POMs and defect sites,achieving catalytic functions unattainable by eithe...The strategic introduction of defects in polyoxometalate-based metal–organic frameworks(POM@MOFs)enables synergistic catalytic effects between POMs and defect sites,achieving catalytic functions unattainable by either component alone.However,the complexity of the POM@MOFs synthetic system makes the controlled construction of defects more challenging than in conventional MOFs.Herein,we develop an atomic substitution-modulated host-vip interaction strategy for controlled synthesis of electron-deficient defect sites in POM@MOFs with tunable missing-linker content.Specifically,the gradual substitution of Mo atoms with V atoms in H_3PMo_(12)O_(40)(PMo_(12))enhances the nucleophilicity of surface oxygen species,thereby strengthening the interaction between POMs and Zr_6-oxo clusters in UiO-67.This enhanced interaction induces varying degrees of ligand loss through coordination competition of POMs with organic ligands during the self-assembly of POM@UiO-67.Meanwhile,POMs acting as electron sponges withdraw electrons from UiO-67,resulting in lower electron density at defect sites compared to traditional defective UiO-67.The induced defect sites exhibit superior catalytic performance in the transfer hydrogenation of cinnamaldehyde,due to a significantly reduced hydrogen transfer energy barrier.This work provides a new perspective for designing crystalline porous catalysts with synergistic effects based on the modulation of host-vip interaction.展开更多
With the proliferation of the Internet,particularly the rise of social media,digital images have gradually become an important part of life,and trading platforms have emerged for buying and selling images.However,trad...With the proliferation of the Internet,particularly the rise of social media,digital images have gradually become an important part of life,and trading platforms have emerged for buying and selling images.However,traditional image trading service providers may disclose users’private information for profit.Additionally,many image trading platforms disregard the fairness of a transaction and the issue of copyright protection after an image is sold.This neglect harms the interests of users and affects their enthusiasm for trading.A secure way to safely transact images is needed.We proposed a copyright-preserving and fair image trading scheme based on blockchain,which combines amplifying locality-sensitive hashing with searchable symmetric encryption to achieve safe image retrieval on blockchain and ensure the credibility of the image retrieval process.Additionally,we use digital fingerprint and watermark technologies to realize the copyright protection of images and use smart contracts to achieve fair transaction processes.The experimental results show that our scheme can protect image copyrights and realize a fair trading process while ensuring efficiency.展开更多
文摘It is of great significance to develop a high-efficiency and low-noise propeller optimization method for new-generation propeller aircraft design.Coupled with free form deformation method,dynamic mesh interpolation technology,optimization algorithm,surrogate model,aerodynamic calculation and aeroacoustic prediction model module,the integrated aerodynamic and aeroacoustic design method of propeller is built.The optimization design for the six-blade propeller is carried out.The non-reduction in efficiency,thrust coefficient and the minimum of aerodynamic noise is treated as the optimization design objective.The spatial vorticity distribution of the propeller before and after the design is also analyzed by using unsteady computational fluid dynamics method.The results show that the optimized propeller can effectively reduce the aerodynamic noise level.The maximum total sound pressure level can be reduced by 5 dB without reducing its aerodynamic performance.The developed method has good application potential in low-noise optimization design of propeller and other rotating machinery.
基金Hongtao Bian acknowledges the support from the National Natural Science Foundation of China(No.22173054)Hongtao Bian also thanks the financial support from Fundamental Research Funds for the Central Universities(GK202001009)+2 种基金Natural Science Fundamental Research Plan of Shaanxi Province(No.2024JC-JCQN-15)111 Project(B14041)Program for Changjiang Scholars and the Innovative Research Team in University(IRT-14R33).
文摘The structure of protein and peptide at interfaces plays a crucial role in various biological processes and technological advancements.Understanding these structures is critical for diagnosing diseases,drug delivery,and developing biomaterials.However,the complexity of these systems and limitations in analytical tools have hindered the in-depth exploration.Despite significant efforts in determining protein structures using advanced techniques like X-ray crystallography and cryo-electron microscopy,the understanding of surface-bound protein structures in real conditions remains relatively limited,posing a current challenge in this field.Vibrational sum frequency generation(SFG)spectroscopy has been developed as a versatile method for elucidating molecular structures of proteins across interfaces.This review is intended to introduce the basic principle of SFG spectroscopy,discuss its current advancements in phase measurement,and showcase recent examples(2021-2023)illustrating SFG’s ability in revealing the molecular structure of peptides and proteins at interfaces.This concise review aims to establish a foundation for future studies and applications exploring different types of peptides and proteins at interfaces using SFG.
基金supported by the National Natural Science Foundation of China(22171035)Liaoning Provincial Science and Technology Programme Joint Programme(2024-MSLH-068)+3 种基金Liaoning Provincial Natural Science Foundation Joint Fund(Doctoral Research Start-up Project)(2023-BSBA-088 and 2023-BSBA-087)the Fundamental Research Funds for the Central Universities(DUT24BS067 and DUT24BS068)China Postdoctoral Science Foundation(2024M750307)the fund of the State Key Laboratory of Catalysis in Dalian Institute of Chemical Physics(N-21-08)。
文摘The strategic introduction of defects in polyoxometalate-based metal–organic frameworks(POM@MOFs)enables synergistic catalytic effects between POMs and defect sites,achieving catalytic functions unattainable by either component alone.However,the complexity of the POM@MOFs synthetic system makes the controlled construction of defects more challenging than in conventional MOFs.Herein,we develop an atomic substitution-modulated host-vip interaction strategy for controlled synthesis of electron-deficient defect sites in POM@MOFs with tunable missing-linker content.Specifically,the gradual substitution of Mo atoms with V atoms in H_3PMo_(12)O_(40)(PMo_(12))enhances the nucleophilicity of surface oxygen species,thereby strengthening the interaction between POMs and Zr_6-oxo clusters in UiO-67.This enhanced interaction induces varying degrees of ligand loss through coordination competition of POMs with organic ligands during the self-assembly of POM@UiO-67.Meanwhile,POMs acting as electron sponges withdraw electrons from UiO-67,resulting in lower electron density at defect sites compared to traditional defective UiO-67.The induced defect sites exhibit superior catalytic performance in the transfer hydrogenation of cinnamaldehyde,due to a significantly reduced hydrogen transfer energy barrier.This work provides a new perspective for designing crystalline porous catalysts with synergistic effects based on the modulation of host-vip interaction.
基金supported by the National Natural Science Foundation of China(Nos.62062016,U21A20474)Guangxi Natural Science Foundation(No.2019JJA170060)+1 种基金Jiangsu Provincial Key Laboratory of Network and Information Security(No.BM2003201)Guangxi Science and Technology project(Nos.GuikeAA22067070,GuikeAD21220114).
文摘With the proliferation of the Internet,particularly the rise of social media,digital images have gradually become an important part of life,and trading platforms have emerged for buying and selling images.However,traditional image trading service providers may disclose users’private information for profit.Additionally,many image trading platforms disregard the fairness of a transaction and the issue of copyright protection after an image is sold.This neglect harms the interests of users and affects their enthusiasm for trading.A secure way to safely transact images is needed.We proposed a copyright-preserving and fair image trading scheme based on blockchain,which combines amplifying locality-sensitive hashing with searchable symmetric encryption to achieve safe image retrieval on blockchain and ensure the credibility of the image retrieval process.Additionally,we use digital fingerprint and watermark technologies to realize the copyright protection of images and use smart contracts to achieve fair transaction processes.The experimental results show that our scheme can protect image copyrights and realize a fair trading process while ensuring efficiency.
