Aging and circadian rhythms have been connected for decades,but their molecular interaction has remained unknown,especially for cancers.In this situation,we summarized the current research actuality and problems in th...Aging and circadian rhythms have been connected for decades,but their molecular interaction has remained unknown,especially for cancers.In this situation,we summarized the current research actuality and problems in this field using the bibliometric analysis.Publications in the PubMed and Web of Science databases were retrieved.Overall,there is a rising trend in the publication volume regarding aging and circadian rhythms in the field of cancer.Researchers from USA,Germany,Italy,China and England have greater studies than others.Top three publication institutions are University of California System,UDICE-French Research Universities and University of Texas System.Current research hotspots include oxidative stress,breast cancer,melatonin,cell cycle,calorie restriction,prostate cancer and NF-κB.In conclusion,results generated by bibliometric analysis indicate that many approaches involve in the complex interactions between aging and circadian rhythm in cancer.These established and emerging research directions guide our exploration of the regulatory mechanisms of aging and circadian rhythms in cancer and provide a reference for developing new research avenues.展开更多
The controllable transfer of droplets on the surface of objects has a wide application prospect in the fields of microfluidic devices,fog collection and so on.The Leidenfrost effect can be utilized to significantly re...The controllable transfer of droplets on the surface of objects has a wide application prospect in the fields of microfluidic devices,fog collection and so on.The Leidenfrost effect can be utilized to significantly reduce motion resistance.However,the use of 3D structures limits the widespread application of self-propulsion based on Leidenfrost droplets in microelectromechanical system.To manipulate Leidenfrost droplets,it is necessary to create 2D or quasi-2D geometries.In this study,femtosecond laser is applied to fabricate a surface with periodic hydrophobicity gradient(SPHG),enabling directional self-propulsion of Leidenfrost droplets.Flow field analysis within the Leidenfrost droplets reveals that the vapor layer between the droplets and the hot surface can be modulated by the SPHG,resulting in directional propulsion of the inner gas.The viscous force between the gas and liquid then drives the droplet to move.展开更多
In this study,we investigated the oxidation of the Mg-11Y-1Al alloy at 500℃in an Ar-20%O2environment.Multiscale analysis showed the network-like long-period stacking ordered(LPSO)phase transformed into needle-like LP...In this study,we investigated the oxidation of the Mg-11Y-1Al alloy at 500℃in an Ar-20%O2environment.Multiscale analysis showed the network-like long-period stacking ordered(LPSO)phase transformed into needle-like LPSO and polygonal Mg24Y5 phases,leading to the formation of a high-dense network of needle-like oxides at the oxidation front.These oxides grew laterally along the oxide/matrix interfaces,forming a thicker,continuous scale that effectively blocked elemental diffusion.Hence,the preferential oxidation along the needle-like LPSO is believed to accelerate the formation of a thicker and continuous oxide scale,further improving the oxidation resistance of the Mg-11Y-1Al alloy.展开更多
Oil Vapor recovery is a critical process in downstream chemical industries, in oil and gas industries and in environmental protection. For that purpose, highly-efficient absorbent materials for vapor recovery are in h...Oil Vapor recovery is a critical process in downstream chemical industries, in oil and gas industries and in environmental protection. For that purpose, highly-efficient absorbent materials for vapor recovery are in high demand and their associated adsorption kinetics is of great importance for their performance. As oil vapor consists of multiple components with different physical and chemical properties, modeling the overall adsorption kinetics of activated carbon for multi-component oil vapor is essentially valuable for industrial applications. In this work, we developed a comprehensive model of multi-component gas adsorption kinetics on activated carbon in a packed-bed reactor and numerically solved the model by the finite element method. The predictions from the model are all in the reasonable range indicating good validity of the model. Some dimensionless parameters are also derived to further investigate the prediction results.展开更多
Most proteins adopt an approximate structural symmetry. However, they have no symmetry detectable in their sequences and it is unclear for most of these proteins whether their structural symmetry originates from dupli...Most proteins adopt an approximate structural symmetry. However, they have no symmetry detectable in their sequences and it is unclear for most of these proteins whether their structural symmetry originates from duplication. As one of the six popular folds (super-folds) possessing an approximate structural symmetry, the triosephosphate isomerase barrel (TIM-barrel) domain has been widely studied. Using modified recurrent quantification analysis of primary sequences, we identified the same 2-, 3-, and 4-fold symmetry pattern as their tertiary structures. This result indicates that the symmetry in tertiary structure is coded by symmetry in the primary sequence and that the TIM-barrel adopts a 2-, 3-, or 4-fold repeat pattern during evolution. This discovery will be useful for understanding the evolutionary mechanisms of this protein family and the symmetry pattern that may be a clue into the ancient origin of duplication of half-barrels or the β a unit.展开更多
A high-performance single-pole single-throw(SPST) RF switch for mobile phone RF front-end modules(FEMs) was designed and characterized in a 0.13 μm partially depleted silicon-on-insulator(PD SOI) process. In this pap...A high-performance single-pole single-throw(SPST) RF switch for mobile phone RF front-end modules(FEMs) was designed and characterized in a 0.13 μm partially depleted silicon-on-insulator(PD SOI) process. In this paper, the traditional seriesshunt configuration design was improved by introducing a suitably large DC bias resistor and leakage-preventing PMOS, together with the floating body technique. The performance of the RF switch is greatly improved. Furthermore, a new Ron × Coff testing method is also proposed. The size of this SPST RF switch is 0.2 mm2. This switch can be widely used for present 4 G and forthcoming 5 G mobile phone FEMs.展开更多
Recently, the g-C3N4-based heterojunctions have been widely investigated for their greatly enhanced photogenerated carrier separation efficiency. However, most studies are based on the study of g-C3N4 powders. In this...Recently, the g-C3N4-based heterojunctions have been widely investigated for their greatly enhanced photogenerated carrier separation efficiency. However, most studies are based on the study of g-C3N4 powders. In this study, a novel TiN/C3N4/CdS nanotube arrays core/shell structure is designed to improve the photoelectrochemical catalytic performance of the g-C3N4-based heterojunctions. Among them, TiN nanotube arrays do not respond to simulated solar light, and thus only serve as an excellently conductive nanotube arrays backbone for supporting g-C3N4/CdS heterojunctions. g-C3N4 prepared by simple liquid atomic layer deposition, which possesses appropriate energy band position, mainly acts as the electron acceptor to transport and separate electrons. Deposited CdS quantum dots obtained by successive ionic layer adsorption reaction can effectively absorb visible light and thus act as a light absorber. The TiN/C3N4/CdS nanotube arrays core/shell structure could be verified by X-ray diffractions, Raman spectra, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy elemental mappings and X-ray photoelectron spectroscopy. Compared with TiN/C3N4 nanotube arrays, the TiN/C3N4/CdS samples greatly improve the photoelectrochemical performance, which can be evaluated by photoelectrochemical tests and photoelectrochemical catalytic degradation. Especially, the optimized photocurrent density of TiN/C3N4/CdS has almost 120 times improvement on TiN/C3N4 at 0 V bias under simulated sunlight, which can be ascribed to the effective expansion of the light absorption range and separation of electron-hole pairs.展开更多
The plow of the submarine plowing trencher is one of the main functional mechanisms, and its optimization is very important. The design parameters play a very significant role in determining the requirements of the to...The plow of the submarine plowing trencher is one of the main functional mechanisms, and its optimization is very important. The design parameters play a very significant role in determining the requirements of the towing force of a vessel. A multi-objective genetic algorithm based on analytical models of the plow surface has been examined and applied in efforts to obtain optimal design of the plow. For a specific soil condition, the draft force and moldboard surface area which are the key parameters in the working process of the plow are optimized by finding the corresponding optimal values of the plow blade penetration angle and two surface angles of the main cutting blade of the plow. Parameters such as the moldboard side angle of deviation, moldboard lift angle, angular variation of the tangent line, and the spanning length are also analyzed with respect to the force of the moldboard surface along soil flow direction. Results show that the optimized plow has an improved plow performance. The draft forces of the main cutting blade and the moldboard are 10.6% and 7%, respectively, less than the original design. The standard deviation of Gaussian curvature of moldboard is lowered by 64.5%, which implies that the smoothness of the optimized moldboard surface is much greater than the original.展开更多
Objective To discover critical genes contributing to the sternness and maintenance of spermatogonial stem cells(SSCs)and provide new insights into the function of the leucine-rich repeat(LRR)family member Lrrc34(leudn...Objective To discover critical genes contributing to the sternness and maintenance of spermatogonial stem cells(SSCs)and provide new insights into the function of the leucine-rich repeat(LRR)family member Lrrc34(leudne-rich repeat-containing 34)in SSCs from mice.Methods Bioinformatic methods,including differentially expressed gene(DEG),gene ontology(GO)enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses,were used to uncover latent pluripotency-related genes.Reverse transcription-polymerase chain reaction(RT-PCR)and immunofluorescence analyses were utilized to verify the mRNA and protein expression levels,respectively.RNA interference of Lrrc34 using siRNA was performed to detect its transient impact on SSCs.Results Eight DEGs between ID4-EGFP+(G)and ID4-EGFP+/TSPAN8Hig11(TH),eight DEGs between G and ID4-EGFP+/TSPAN8Uw(TL)and eleven DEGs between TH and TL were discovered,and eleven proteinprotein interaction(PPI)modules were found to be significant in the PPI network of DEGs.One of the DEGs,Lrrc34,was selected as a potential pluripotency?related gene due to its differential expression among ID4-EGFP+spermatogonia subsets and its interaction with fibroblast growth factor 2 in the fifth module.Immunofluorescence experiments exhibited specific expression of Lrrc34 in a subpopulation of undifferentiated spermatogonia marked by LIN28A,and RT-PCR experiments confirmed the high expression of Lrrc34 in SSCs from P7 and adult mice.The transient knockdown of Lrrc34 in SSCs resulted in reduced colony sizes and significant changes in the transcriptome and apoptotic pathways.Conclusion Lrrc34 is highly expressed in mouse SSCs and is required for SSC proliferation in vitro through effects on transcriptome and signaling transduction pathways.展开更多
As the fundamental problem in the computer vision area,image matching has wide applications in pose estimation,3D reconstruction,image retrieval,etc.Suffering from the influence of external factors,the process of imag...As the fundamental problem in the computer vision area,image matching has wide applications in pose estimation,3D reconstruction,image retrieval,etc.Suffering from the influence of external factors,the process of image matching using classical local detectors,e.g.,scale-invariant feature transform(SIFT),and the outlier filtering approaches,e.g.,Random sample consensus(RANSAC),show high computation speed and pool robustness under changing illumination and viewpoints conditions,while image matching approaches with deep learning strategy(such as HardNet,OANet)display reliable achievements in large-scale datasets with challenging scenes.However,the past learning-based approaches are limited to the distinction and quality of the dataset and the training strategy in the image-matching approaches.As an extension of the previous conference paper,this paper proposes an accurate and robust image matching approach using fewer training data in an end-to-end manner,which could be used to estimate the pose error This research first proposes a novel dataset cleaning and construction strategy to eliminate the noise and improve the training efficiency;Secondly,a novel loss named quadratic hinge triplet loss(QHT)is proposed to gather more effective and stable feature matching;Thirdly,in the outlier filtering process,the stricter OANet and bundle adjustment are applied for judging samples by adding the epipolar distance constraint and triangulation constraint to generate more outstanding matches;Finally,to recall the matching pairs,dynamic guided matching is used and then submit the inliers after the PyRANSAC process.Multiple evaluation metrics are used and reported in the 1st place in the Track1 of CVPR Image-Matching Challenge Workshop.The results show that the proposed method has advanced performance in large-scale and challenging Phototourism benchmark.展开更多
Complicated electromagnetic environments of the space situational awareness facilities(i.e.,satellite navigation systems,radar)would significantly impact normal operations.Effective monitoring and the corresponding di...Complicated electromagnetic environments of the space situational awareness facilities(i.e.,satellite navigation systems,radar)would significantly impact normal operations.Effective monitoring and the corresponding diagnosis of the jamming signals are essential to normal opera-tions and the innovations in anti-jamming equipment.This paper demonstrates a comprehensive survey on jamming monitoring algorithms and applications.The methods in dealing with jamming signals are summarized primarily.Subsequently,the jamming detection,identification,and direc-tion finding techniques are addressed separately.Based on the established studies,we also provide some potential trends of the demonstrated jamming monitoring issues.展开更多
With various potential health-promoting bioactivities,genistein has great prospects in treatment of a series of complex diseases and metabolic syndromes such as cancer,diabetes,cardiovascular diseases,menopausal sympt...With various potential health-promoting bioactivities,genistein has great prospects in treatment of a series of complex diseases and metabolic syndromes such as cancer,diabetes,cardiovascular diseases,menopausal symptoms and so on.However,poor solubility and unsatisfactory bioavailability seriously limits its clinical application and market development.To optimize the solubility and bioavailability of genistein,the cocrystal of genistein and piperazine was prepared by grinding assisted with solvent based on the concept of cocrystal engineering.Using a series of analytical techniques including single-crystal X-ray diffraction,powder X-ray diffraction,Fourier transform infrared spectroscopy,differential scanning calorimetry and thermogravimetric analysis,the cocrystal was characterized and confirmed.Then,structure analysis on the basis of theoretical calculation and a series of evaluation on the stability,dissolution and bioavailability were carried out.The results indicated that the cocrystal of genistein and piperazine improved the solubility and bioavailability of genistein.Compared with the previous studies on the cocrystal of genistein,this is a systematic and comprehensive investigation from the aspects of preparation,characterization,structural analysis,stability,solubility and bioavailability evaluation.As a simple,efficient and green approach,cocrystal engineering can pave a new path to optimize the pharmaceutical properties of natural products for successful drug formulation and delivery.展开更多
Currently,rotary drilling is one of the main pieces of equipment used for in-situ remediation of contaminated soil.However,this equipment has problems such as uneven mixing and low utilization efficiency,which affect ...Currently,rotary drilling is one of the main pieces of equipment used for in-situ remediation of contaminated soil.However,this equipment has problems such as uneven mixing and low utilization efficiency,which affect the efficiency of in-situ soil remediation.To improve the efficiency of in-situ soil remediation,this paper takes contaminated black soil as the research object,and the structural design of the new three-stage soil remediation auger is carried out based on SolidWorks.The mixing process of soil and heavy metal passivator under different motion and structural parameters was investigated by the discrete element method(DEM)and response surface methodology.The experimental design was based on rotational speed,homogenizing mixing time,crushing section pitch,and homogenizing section pitch as factors,and soil fragmentation ratio,the coefficient of dispersion,and torque as optimization indices.The kinematic and structural parameters of the three-stage auger drill bit were then optimized using the one-factor method,the orthogonal test,and the response surface methodology,respectively.The test method uses a one-way test to determine the central level value of the orthogonal test and a comprehensive balance method to determine the best combination of parameters for the orthogonal test,which is then used as the central value of the response surface test for parameter optimization.The optimal combinations of kinematic and structural parameters of the three-stage auger drill bit are determined and validated using response surface methodology.The optimum combination of parameters was found to be a speed of 129 rpm,a homogenizing mixing time of 24 s,a pitch of 165 mm in the crushing section,and a pitch of 132 mm in the homogenizing section.The error between the optimal value of the predicted model using the response surface method and the actual simulated value under the optimal parameters is 4.2%,4.9%,and 5.3%,respectively.The optimized factor parameters provide a reference for the design of the structural and kinematic parameters of the in-situ homogenization equipment.展开更多
The effect of rare earth addition on the microstructure and mechanical performances of as-cast and wrought Al alloys has been attracting increasing attention recently.Rare earth addition has great potential in modifyi...The effect of rare earth addition on the microstructure and mechanical performances of as-cast and wrought Al alloys has been attracting increasing attention recently.Rare earth addition has great potential in modifying the structure and improving the properties of materials.However,there are currently few reports about the effect of rare earth addition on the microstructure and performances of Al alloys prepared via selective laser melting.Here,AlSi10Mg alloys were manufactured using selective laser melting,and the effect of Er addition was investigated.The results indicate that Er addition leads toα-Al refinement and modifies the minority Si phase.The formation of the Al_(3)Er phase induced by Er addition enhances the stren gth of the material.Modification of the Si phase also increases ductility.This strategy can help improve the mechanical performance of alum inum alloys prepared via selective laser melting.展开更多
Poppet valves have become increasingly significant in ensuring precise digital flow rate and pressure control in hydraulic systems,necessitating a more profound understanding of the geometrical properties of cavitatio...Poppet valves have become increasingly significant in ensuring precise digital flow rate and pressure control in hydraulic systems,necessitating a more profound understanding of the geometrical properties of cavitation in them,as well as associated flow-choking conditions.Through a comparative analysis with experimentally observed cavity images,we found that large eddy simulation(LES)turbulence modeling effectively replicates the geometrical properties of cavitation in these valves.The analysis demonstrated that cavitation is generated from vortices that result from the interaction between the notch contracta flow and the surrounding fluid structure.Variations in the internal or external vena contracta conditions result in fixed or discrete cavities,and the length-to-diameter ratio serves as a measure of the transition between internal and external vena contracta flow properties.This study establishes a threshold length-to-diameter ratio of approximately 2 for the tested poppet valves.More specifically,in notch structures with a smaller valve opening,longer sealing length,and smaller throttling angle(corresponding to a larger length-to-diameter ratio),the liquid-to-vapor transfer process is more evident than that in the reverse direction.A long-standing vapor cavity becomes fixed inside the notch,leading to a more pronounced flow-choking phenomenon.In contrast,for structures with a smaller length-to-diameter ratio,the cavitation process for discrete vapor cavities is more complete,ensuring fluid flow continuity and significantly reducing the occurrence of the flow-choking phenomenon.展开更多
With rapid development of UAV technology,research on UAV image analysis has gained attention.As the existing techniques of UAV target localization often rely on additional equipment,a method of UAV target localization...With rapid development of UAV technology,research on UAV image analysis has gained attention.As the existing techniques of UAV target localization often rely on additional equipment,a method of UAV target localization based on depth estimation has been proposed.However,the unique perspective of UAVs poses challenges such as the significant field of view variations and the presence of dynamic objects in the scene.As a result,the existing methods of depth estimation and scale recovery cannot be directly applied to UAV perspectives.Additionally,there is a scarcity of depth estimation datasets tailored for UAV perspectives,which makes supervised algorithms impractical.To address these issues,an outlier filter is introduced to enhance the applicability of depth estimation networks to target localization.A frame buffer method is proposed to achieve more accurate scale recovery,so as to handle complex scene textures in UAV images.The proposed method demonstrates a 14.29%improvement over the baseline.Compared with the average recovery results from UAV perspectives,the difference is only 0.88%,approaching the performance of scale recovery using ground truth labels.Furthermore,to overcome the limited availability of traditional UAV depth datasets,a method for generating depth labels from video sequences is proposed.Compared to state-of-the-art methods,the proposed approach achieves higher accuracy in depth estimation and stands for the first attempt at target localization using image sequences.Proposed algorithm and dataset are available at https://github.com/uav-tan/uav-object-localization.展开更多
Magnetic/dielectric composite materials with numerous heterointerfaces are highly promising functional materials, which are widely applied in the fields of electromagnetic wave absorption. Constructing heterogeneous s...Magnetic/dielectric composite materials with numerous heterointerfaces are highly promising functional materials, which are widely applied in the fields of electromagnetic wave absorption. Constructing heterogeneous structure is beneficial to further enhance the microwave absorption performance of composite materials. However, the process of constructing multi-heterogeneous interfaces is extremely complex. In this work, hollow porous FeCo/Cu/CNTs composite microspheres are prepared by the simple spray drying method and subsequently two-step annealing treatment, which possess abundant heterogeneous interfaces, unique three-dimensional conductive network and magnetic coupling network. This unique structure is beneficial to improving the ability of dielectric loss and magnetic loss, and then achieving an excellent microwave absorption performance. The prepared FeCo/Cu/CNTs-1 composite microspheres maintain a minimum reflection loss (RL) of −48.1 dB and a maximum effective absorption bandwidth of 5.76 GHz at a thickness of 1.8 mm. Generally, this work provides a new idea for designing multi-heterogeneous of microwave absorbing materials.展开更多
基金supported by the Chinese Scholarship Council(No.202206240086)Zhejiang Province Public Welfare Technology Application Research Project in China(No.TGY23H160090 and No.LGF21H160029)+1 种基金Taizhou Science and Technology Project,Zhejiang Province(No.20ywb12)Program for Talents of Chongqing University Three Gorges Hospital(No.2022YJKYXM-036).
文摘Aging and circadian rhythms have been connected for decades,but their molecular interaction has remained unknown,especially for cancers.In this situation,we summarized the current research actuality and problems in this field using the bibliometric analysis.Publications in the PubMed and Web of Science databases were retrieved.Overall,there is a rising trend in the publication volume regarding aging and circadian rhythms in the field of cancer.Researchers from USA,Germany,Italy,China and England have greater studies than others.Top three publication institutions are University of California System,UDICE-French Research Universities and University of Texas System.Current research hotspots include oxidative stress,breast cancer,melatonin,cell cycle,calorie restriction,prostate cancer and NF-κB.In conclusion,results generated by bibliometric analysis indicate that many approaches involve in the complex interactions between aging and circadian rhythm in cancer.These established and emerging research directions guide our exploration of the regulatory mechanisms of aging and circadian rhythms in cancer and provide a reference for developing new research avenues.
基金supported by the Beijing Municipal Natural Science Foundation(JQ20015)National Key Research and Development Program of China(No.2022YFB4601300)+3 种基金the National Science Fund for Distinguished Young Scholars(No.52325505)the National Natural Science Foundation of China(NSFC)(No.52075041)the Joint Funds of the National Natural Science Foundation of China(Grant No.U2037205)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No2021WNLOKF016)。
文摘The controllable transfer of droplets on the surface of objects has a wide application prospect in the fields of microfluidic devices,fog collection and so on.The Leidenfrost effect can be utilized to significantly reduce motion resistance.However,the use of 3D structures limits the widespread application of self-propulsion based on Leidenfrost droplets in microelectromechanical system.To manipulate Leidenfrost droplets,it is necessary to create 2D or quasi-2D geometries.In this study,femtosecond laser is applied to fabricate a surface with periodic hydrophobicity gradient(SPHG),enabling directional self-propulsion of Leidenfrost droplets.Flow field analysis within the Leidenfrost droplets reveals that the vapor layer between the droplets and the hot surface can be modulated by the SPHG,resulting in directional propulsion of the inner gas.The viscous force between the gas and liquid then drives the droplet to move.
基金the financial support from the National Key Research and Development Program of China(No.2022YFB3708400)the National Science and Technology Major Project(J2019-VIII-0003-0165)the Space Utilization System of China Manned Space Engineering(No.KJZ-YY-WCL04).
文摘In this study,we investigated the oxidation of the Mg-11Y-1Al alloy at 500℃in an Ar-20%O2environment.Multiscale analysis showed the network-like long-period stacking ordered(LPSO)phase transformed into needle-like LPSO and polygonal Mg24Y5 phases,leading to the formation of a high-dense network of needle-like oxides at the oxidation front.These oxides grew laterally along the oxide/matrix interfaces,forming a thicker,continuous scale that effectively blocked elemental diffusion.Hence,the preferential oxidation along the needle-like LPSO is believed to accelerate the formation of a thicker and continuous oxide scale,further improving the oxidation resistance of the Mg-11Y-1Al alloy.
文摘Oil Vapor recovery is a critical process in downstream chemical industries, in oil and gas industries and in environmental protection. For that purpose, highly-efficient absorbent materials for vapor recovery are in high demand and their associated adsorption kinetics is of great importance for their performance. As oil vapor consists of multiple components with different physical and chemical properties, modeling the overall adsorption kinetics of activated carbon for multi-component oil vapor is essentially valuable for industrial applications. In this work, we developed a comprehensive model of multi-component gas adsorption kinetics on activated carbon in a packed-bed reactor and numerically solved the model by the finite element method. The predictions from the model are all in the reasonable range indicating good validity of the model. Some dimensionless parameters are also derived to further investigate the prediction results.
文摘Most proteins adopt an approximate structural symmetry. However, they have no symmetry detectable in their sequences and it is unclear for most of these proteins whether their structural symmetry originates from duplication. As one of the six popular folds (super-folds) possessing an approximate structural symmetry, the triosephosphate isomerase barrel (TIM-barrel) domain has been widely studied. Using modified recurrent quantification analysis of primary sequences, we identified the same 2-, 3-, and 4-fold symmetry pattern as their tertiary structures. This result indicates that the symmetry in tertiary structure is coded by symmetry in the primary sequence and that the TIM-barrel adopts a 2-, 3-, or 4-fold repeat pattern during evolution. This discovery will be useful for understanding the evolutionary mechanisms of this protein family and the symmetry pattern that may be a clue into the ancient origin of duplication of half-barrels or the β a unit.
文摘A high-performance single-pole single-throw(SPST) RF switch for mobile phone RF front-end modules(FEMs) was designed and characterized in a 0.13 μm partially depleted silicon-on-insulator(PD SOI) process. In this paper, the traditional seriesshunt configuration design was improved by introducing a suitably large DC bias resistor and leakage-preventing PMOS, together with the floating body technique. The performance of the RF switch is greatly improved. Furthermore, a new Ron × Coff testing method is also proposed. The size of this SPST RF switch is 0.2 mm2. This switch can be widely used for present 4 G and forthcoming 5 G mobile phone FEMs.
文摘Recently, the g-C3N4-based heterojunctions have been widely investigated for their greatly enhanced photogenerated carrier separation efficiency. However, most studies are based on the study of g-C3N4 powders. In this study, a novel TiN/C3N4/CdS nanotube arrays core/shell structure is designed to improve the photoelectrochemical catalytic performance of the g-C3N4-based heterojunctions. Among them, TiN nanotube arrays do not respond to simulated solar light, and thus only serve as an excellently conductive nanotube arrays backbone for supporting g-C3N4/CdS heterojunctions. g-C3N4 prepared by simple liquid atomic layer deposition, which possesses appropriate energy band position, mainly acts as the electron acceptor to transport and separate electrons. Deposited CdS quantum dots obtained by successive ionic layer adsorption reaction can effectively absorb visible light and thus act as a light absorber. The TiN/C3N4/CdS nanotube arrays core/shell structure could be verified by X-ray diffractions, Raman spectra, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy elemental mappings and X-ray photoelectron spectroscopy. Compared with TiN/C3N4 nanotube arrays, the TiN/C3N4/CdS samples greatly improve the photoelectrochemical performance, which can be evaluated by photoelectrochemical tests and photoelectrochemical catalytic degradation. Especially, the optimized photocurrent density of TiN/C3N4/CdS has almost 120 times improvement on TiN/C3N4 at 0 V bias under simulated sunlight, which can be ascribed to the effective expansion of the light absorption range and separation of electron-hole pairs.
基金Supported the National Natural Science Foundation of China （No. 51179040） Natural Science Foundation of Heilongjiang Province （No. E200904）
文摘The plow of the submarine plowing trencher is one of the main functional mechanisms, and its optimization is very important. The design parameters play a very significant role in determining the requirements of the towing force of a vessel. A multi-objective genetic algorithm based on analytical models of the plow surface has been examined and applied in efforts to obtain optimal design of the plow. For a specific soil condition, the draft force and moldboard surface area which are the key parameters in the working process of the plow are optimized by finding the corresponding optimal values of the plow blade penetration angle and two surface angles of the main cutting blade of the plow. Parameters such as the moldboard side angle of deviation, moldboard lift angle, angular variation of the tangent line, and the spanning length are also analyzed with respect to the force of the moldboard surface along soil flow direction. Results show that the optimized plow has an improved plow performance. The draft forces of the main cutting blade and the moldboard are 10.6% and 7%, respectively, less than the original design. The standard deviation of Gaussian curvature of moldboard is lowered by 64.5%, which implies that the smoothness of the optimized moldboard surface is much greater than the original.
基金grants from the National Key Research and Development Program of China(2018YFC1003500)the CAMS Innovation Fund for Medical Sciences(2017-I2M-3-009,2016-12M-1-001,and 2017-I2M-1-004)+1 种基金the National Natural Science Foundation of China(81672472 and 31970794)the State Key Laboratory Special Fund from the Ministry of Science of China(2060204).
文摘Objective To discover critical genes contributing to the sternness and maintenance of spermatogonial stem cells(SSCs)and provide new insights into the function of the leucine-rich repeat(LRR)family member Lrrc34(leudne-rich repeat-containing 34)in SSCs from mice.Methods Bioinformatic methods,including differentially expressed gene(DEG),gene ontology(GO)enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses,were used to uncover latent pluripotency-related genes.Reverse transcription-polymerase chain reaction(RT-PCR)and immunofluorescence analyses were utilized to verify the mRNA and protein expression levels,respectively.RNA interference of Lrrc34 using siRNA was performed to detect its transient impact on SSCs.Results Eight DEGs between ID4-EGFP+(G)and ID4-EGFP+/TSPAN8Hig11(TH),eight DEGs between G and ID4-EGFP+/TSPAN8Uw(TL)and eleven DEGs between TH and TL were discovered,and eleven proteinprotein interaction(PPI)modules were found to be significant in the PPI network of DEGs.One of the DEGs,Lrrc34,was selected as a potential pluripotency?related gene due to its differential expression among ID4-EGFP+spermatogonia subsets and its interaction with fibroblast growth factor 2 in the fifth module.Immunofluorescence experiments exhibited specific expression of Lrrc34 in a subpopulation of undifferentiated spermatogonia marked by LIN28A,and RT-PCR experiments confirmed the high expression of Lrrc34 in SSCs from P7 and adult mice.The transient knockdown of Lrrc34 in SSCs resulted in reduced colony sizes and significant changes in the transcriptome and apoptotic pathways.Conclusion Lrrc34 is highly expressed in mouse SSCs and is required for SSC proliferation in vitro through effects on transcriptome and signaling transduction pathways.
文摘As the fundamental problem in the computer vision area,image matching has wide applications in pose estimation,3D reconstruction,image retrieval,etc.Suffering from the influence of external factors,the process of image matching using classical local detectors,e.g.,scale-invariant feature transform(SIFT),and the outlier filtering approaches,e.g.,Random sample consensus(RANSAC),show high computation speed and pool robustness under changing illumination and viewpoints conditions,while image matching approaches with deep learning strategy(such as HardNet,OANet)display reliable achievements in large-scale datasets with challenging scenes.However,the past learning-based approaches are limited to the distinction and quality of the dataset and the training strategy in the image-matching approaches.As an extension of the previous conference paper,this paper proposes an accurate and robust image matching approach using fewer training data in an end-to-end manner,which could be used to estimate the pose error This research first proposes a novel dataset cleaning and construction strategy to eliminate the noise and improve the training efficiency;Secondly,a novel loss named quadratic hinge triplet loss(QHT)is proposed to gather more effective and stable feature matching;Thirdly,in the outlier filtering process,the stricter OANet and bundle adjustment are applied for judging samples by adding the epipolar distance constraint and triangulation constraint to generate more outstanding matches;Finally,to recall the matching pairs,dynamic guided matching is used and then submit the inliers after the PyRANSAC process.Multiple evaluation metrics are used and reported in the 1st place in the Track1 of CVPR Image-Matching Challenge Workshop.The results show that the proposed method has advanced performance in large-scale and challenging Phototourism benchmark.
基金supported by the National Key Research and De-velopment Program of China(2020YFB0505601)。
文摘Complicated electromagnetic environments of the space situational awareness facilities(i.e.,satellite navigation systems,radar)would significantly impact normal operations.Effective monitoring and the corresponding diagnosis of the jamming signals are essential to normal opera-tions and the innovations in anti-jamming equipment.This paper demonstrates a comprehensive survey on jamming monitoring algorithms and applications.The methods in dealing with jamming signals are summarized primarily.Subsequently,the jamming detection,identification,and direc-tion finding techniques are addressed separately.Based on the established studies,we also provide some potential trends of the demonstrated jamming monitoring issues.
基金the National Natural Science Foundation of China(Grant No.22278443)CAMS Innovation Fund for Medical Sciences(Grant No.2022-I2M-1-015)the Chinese Pharmacopoeia Commission Drug Standard Promoting Fund(Grant No.2023Y11)for financial support.
文摘With various potential health-promoting bioactivities,genistein has great prospects in treatment of a series of complex diseases and metabolic syndromes such as cancer,diabetes,cardiovascular diseases,menopausal symptoms and so on.However,poor solubility and unsatisfactory bioavailability seriously limits its clinical application and market development.To optimize the solubility and bioavailability of genistein,the cocrystal of genistein and piperazine was prepared by grinding assisted with solvent based on the concept of cocrystal engineering.Using a series of analytical techniques including single-crystal X-ray diffraction,powder X-ray diffraction,Fourier transform infrared spectroscopy,differential scanning calorimetry and thermogravimetric analysis,the cocrystal was characterized and confirmed.Then,structure analysis on the basis of theoretical calculation and a series of evaluation on the stability,dissolution and bioavailability were carried out.The results indicated that the cocrystal of genistein and piperazine improved the solubility and bioavailability of genistein.Compared with the previous studies on the cocrystal of genistein,this is a systematic and comprehensive investigation from the aspects of preparation,characterization,structural analysis,stability,solubility and bioavailability evaluation.As a simple,efficient and green approach,cocrystal engineering can pave a new path to optimize the pharmaceutical properties of natural products for successful drug formulation and delivery.
基金funding from the National Key Research and Development Plan of China(grant No.2020YFC1806402)the Shenyang Science and Technology Plan Project(grant No.20-202-4-37).
文摘Currently,rotary drilling is one of the main pieces of equipment used for in-situ remediation of contaminated soil.However,this equipment has problems such as uneven mixing and low utilization efficiency,which affect the efficiency of in-situ soil remediation.To improve the efficiency of in-situ soil remediation,this paper takes contaminated black soil as the research object,and the structural design of the new three-stage soil remediation auger is carried out based on SolidWorks.The mixing process of soil and heavy metal passivator under different motion and structural parameters was investigated by the discrete element method(DEM)and response surface methodology.The experimental design was based on rotational speed,homogenizing mixing time,crushing section pitch,and homogenizing section pitch as factors,and soil fragmentation ratio,the coefficient of dispersion,and torque as optimization indices.The kinematic and structural parameters of the three-stage auger drill bit were then optimized using the one-factor method,the orthogonal test,and the response surface methodology,respectively.The test method uses a one-way test to determine the central level value of the orthogonal test and a comprehensive balance method to determine the best combination of parameters for the orthogonal test,which is then used as the central value of the response surface test for parameter optimization.The optimal combinations of kinematic and structural parameters of the three-stage auger drill bit are determined and validated using response surface methodology.The optimum combination of parameters was found to be a speed of 129 rpm,a homogenizing mixing time of 24 s,a pitch of 165 mm in the crushing section,and a pitch of 132 mm in the homogenizing section.The error between the optimal value of the predicted model using the response surface method and the actual simulated value under the optimal parameters is 4.2%,4.9%,and 5.3%,respectively.The optimized factor parameters provide a reference for the design of the structural and kinematic parameters of the in-situ homogenization equipment.
基金Project supported by the National Natural Science Foundation of China(51974092,U21A2043)Guangdong Basic and Applied Basic Research Foundation(2020A1515110136,2020B1515120065,2022B1515120066)Dongguan Science and Technology Special Agent Project(20221800500212)。
文摘The effect of rare earth addition on the microstructure and mechanical performances of as-cast and wrought Al alloys has been attracting increasing attention recently.Rare earth addition has great potential in modifying the structure and improving the properties of materials.However,there are currently few reports about the effect of rare earth addition on the microstructure and performances of Al alloys prepared via selective laser melting.Here,AlSi10Mg alloys were manufactured using selective laser melting,and the effect of Er addition was investigated.The results indicate that Er addition leads toα-Al refinement and modifies the minority Si phase.The formation of the Al_(3)Er phase induced by Er addition enhances the stren gth of the material.Modification of the Si phase also increases ductility.This strategy can help improve the mechanical performance of alum inum alloys prepared via selective laser melting.
基金supported by the National Natural Science Foundation of China(Nos.52075387 and 52375060)the Shanghai Natural Science Foundation of China(No.22ZR1464400)+2 种基金the National Key R&D Program of China(No.2019YFB2005102)the Shanghai Municipal Science and Technology Major Project(No.2021SHZDZX0100)the Fundamental Research Funds for the Central Universities(No.2022-1-ZD-04),China.
文摘Poppet valves have become increasingly significant in ensuring precise digital flow rate and pressure control in hydraulic systems,necessitating a more profound understanding of the geometrical properties of cavitation in them,as well as associated flow-choking conditions.Through a comparative analysis with experimentally observed cavity images,we found that large eddy simulation(LES)turbulence modeling effectively replicates the geometrical properties of cavitation in these valves.The analysis demonstrated that cavitation is generated from vortices that result from the interaction between the notch contracta flow and the surrounding fluid structure.Variations in the internal or external vena contracta conditions result in fixed or discrete cavities,and the length-to-diameter ratio serves as a measure of the transition between internal and external vena contracta flow properties.This study establishes a threshold length-to-diameter ratio of approximately 2 for the tested poppet valves.More specifically,in notch structures with a smaller valve opening,longer sealing length,and smaller throttling angle(corresponding to a larger length-to-diameter ratio),the liquid-to-vapor transfer process is more evident than that in the reverse direction.A long-standing vapor cavity becomes fixed inside the notch,leading to a more pronounced flow-choking phenomenon.In contrast,for structures with a smaller length-to-diameter ratio,the cavitation process for discrete vapor cavities is more complete,ensuring fluid flow continuity and significantly reducing the occurrence of the flow-choking phenomenon.
基金financial support from the National Key Research and Development Program of China (Nos. 2022YFB3904303 and 2020YFB0505602)the National Natural Science Foundation of China (Nos. 62076019, 62022012, U2233217, 62101019 and 62371029)the Civil Aviation Security Capacity Building Fund Project, China (Nos. CAAC Contract 2020(123), CAAC Contract 2021(77) and CAAC Contract 2022(110))
文摘With rapid development of UAV technology,research on UAV image analysis has gained attention.As the existing techniques of UAV target localization often rely on additional equipment,a method of UAV target localization based on depth estimation has been proposed.However,the unique perspective of UAVs poses challenges such as the significant field of view variations and the presence of dynamic objects in the scene.As a result,the existing methods of depth estimation and scale recovery cannot be directly applied to UAV perspectives.Additionally,there is a scarcity of depth estimation datasets tailored for UAV perspectives,which makes supervised algorithms impractical.To address these issues,an outlier filter is introduced to enhance the applicability of depth estimation networks to target localization.A frame buffer method is proposed to achieve more accurate scale recovery,so as to handle complex scene textures in UAV images.The proposed method demonstrates a 14.29%improvement over the baseline.Compared with the average recovery results from UAV perspectives,the difference is only 0.88%,approaching the performance of scale recovery using ground truth labels.Furthermore,to overcome the limited availability of traditional UAV depth datasets,a method for generating depth labels from video sequences is proposed.Compared to state-of-the-art methods,the proposed approach achieves higher accuracy in depth estimation and stands for the first attempt at target localization using image sequences.Proposed algorithm and dataset are available at https://github.com/uav-tan/uav-object-localization.
基金supported by the National Natural Science Foundation of China(Nos.52231007,12327804,T2321003,and 22088101)in part by the National Key Research Program of China(No.2021YFA1200600)+2 种基金the Science and Technology Research Project of Jiangxi Provincial Department of Education(No.GJJ200338)the Fund of Science and Technology on Surface Physics and Chemistry Laboratory(No.JCKYS2023120201)the Fund of Key Laboratory of High Temperature Electromagnetic Materials and Structure of MOE(No.KB202401).
文摘Magnetic/dielectric composite materials with numerous heterointerfaces are highly promising functional materials, which are widely applied in the fields of electromagnetic wave absorption. Constructing heterogeneous structure is beneficial to further enhance the microwave absorption performance of composite materials. However, the process of constructing multi-heterogeneous interfaces is extremely complex. In this work, hollow porous FeCo/Cu/CNTs composite microspheres are prepared by the simple spray drying method and subsequently two-step annealing treatment, which possess abundant heterogeneous interfaces, unique three-dimensional conductive network and magnetic coupling network. This unique structure is beneficial to improving the ability of dielectric loss and magnetic loss, and then achieving an excellent microwave absorption performance. The prepared FeCo/Cu/CNTs-1 composite microspheres maintain a minimum reflection loss (RL) of −48.1 dB and a maximum effective absorption bandwidth of 5.76 GHz at a thickness of 1.8 mm. Generally, this work provides a new idea for designing multi-heterogeneous of microwave absorbing materials.
