Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically time-consuming.To address these issues,this study proposes a new technological method to des...Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically time-consuming.To address these issues,this study proposes a new technological method to design and prepare a high-performance assembled asphalt concrete block for fast repair of the potholes.A series of composite modified asphalt binders with 10%crumb rubber(CR)and different dosages(0%,1%,3%,5%)of polyurethane(PU)are examined to determine the optimized binder.Subsequently,the corresponding asphalt mixtures are prepared for further comparison and assessment of engineering properties,such as moistureinduced damage,high-temperature deformation,and low-temperature cracking characteristics.The test results show that PU can significantly improve the high-temperature performance and hardness of(crumb rubber modified asphalt)CRMA binder;3%PU contributes allowing the resistance of CRMA mixture to moisture-induced damage at higher levels,particularly under water whole immersion;as 3%PU is added,the high-temperature rutting deformation resistance of the CRMA mixture increases significantly,and the low-temperature anti-cracking properties are also improved slightly.Therefore,the innovatively designed high-quality assembled fast-repairing asphalt concrete block is recommended as an appropriate option for highway maintenance.展开更多
Segmentally assembled bridges are increasinglyfinding engineering applications in recent years due to their unique advantages,especially as urban viaducts.Vehicle loads are one of the most important variable loads acti...Segmentally assembled bridges are increasinglyfinding engineering applications in recent years due to their unique advantages,especially as urban viaducts.Vehicle loads are one of the most important variable loads acting on bridge structures.Accordingly,the influence of overloaded vehicles on existing assembled bridge structures is an urgent concern at present.This paper establishes thefinite element model of the segmentally assembled bridge based on ABAQUS software and analyzes the influence of vehicle overload on an assembled girder bridge struc-ture.First,afinite element model corresponding to the target bridge is established based on ABAQUS software,and the load is controlled to simulate vehicle movement in each area of the traveling zone at different times.Sec-ond,the key cross-sections of segmental girder bridges are monitored in real time based on the force character-istics of continuous girder bridges,and they are compared with the simulation results.Finally,a material damage ontology model is introduced,and the structural damage caused by different overloading rates is compared and analyzed.Results show that thefinite element modeling method is accurate by comparing with on-site measured data,and it is suitable for the numerical simulation of segmental girder bridges;Dynamic sensors installed at 1/4L,1/2L,and 3/4L of the segmental girder main beams could be used to identify the dynamic response of segmental girder bridges;The bottom plate of the segmental girder bridge is mostly damaged at the position where the length of the precast beam section changes and the midspan position.With the increase in load,damage in the direction of the bridge develops faster than that in the direction of the transverse bridge.Thefindings of this study can guide maintenance departments in the management and maintenance of bridges and vehicles.展开更多
As an efficient,environmentally friendly,energy-saving construction method,assembled buildings are now widely used in campus building construction.Modular design thinking is system-based design thinking,and its applic...As an efficient,environmentally friendly,energy-saving construction method,assembled buildings are now widely used in campus building construction.Modular design thinking is system-based design thinking,and its application to the design of an assembled teaching building project will comprehensively improve the rationality of the teaching building and component design.The paper focuses on the application of modular design thinking in assembled teaching building design,aiming to provide references for China’s architectural design units,giving full play to the advantages of modular design thinking in future teaching building design projects,and enhancing the level of design,for the construction of the teaching building and the basis of the technical guarantee.展开更多
To enhance the corrosion resistance of magnesium(Mg) alloy and to impart its surface with antibacterial functionality for inhibiting biofilm formation and biocorrosion, Mg(OH)2 films were fabricated on AZ31 magnes...To enhance the corrosion resistance of magnesium(Mg) alloy and to impart its surface with antibacterial functionality for inhibiting biofilm formation and biocorrosion, Mg(OH)2 films were fabricated on AZ31 magnesium alloy substrates by an in-situ hydrothermal method and well-defined multilayer coatings, consisting of gentamicin sulfate(GS) and poly(sodium 4-styrene sulfonate)(PSS), were prepared via layer-by-layer(Lb L) assembly. The morphologies, chemical compositions and corrosion resistance of the obtained(PSS/GS)n/Mg sample were investigated using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, electrochemical methods and immersion tests. Finally, the bactericidal activity of(PSS/GS)n/Mg samples against Staphylococcus aureus was assessed by the zone of inhibition methods and plate-counting method. The so-synthesized composite coating on the Mg alloy substrates exhibits good corrosion resistance and antibacterial performance, which make them attractive as coatings for medical implanted devices.展开更多
This work aims to improve the thermal performance of a light emitting diode(LED) module by employing a novelly assembled heat pipe heat sink. The heat pipe was embedded into the heat sink by a phase change expansion a...This work aims to improve the thermal performance of a light emitting diode(LED) module by employing a novelly assembled heat pipe heat sink. The heat pipe was embedded into the heat sink by a phase change expansion assembly(PCEA) process, which was developed by both finite element(FE) analysis and experiments. Heat transfer performance and optical performance of the LED modules were experimentally investigated and discussed. Compared to the LED module with a traditionally assembled heat pipe heat sink, the LED module employing the PCEA process exhibits about 20% decrease in the thermal resistance from the MCPCB to the heat pipe. The junction temperature is 4% lower and the luminous flux is 2% higher. The improvement in the thermal and optical performance is important to the high power LED applications.展开更多
Surface functionalization of magnesium(Mg)alloys is desired to obtain the surfaces with both improved corrosion resistance and antibacterial property.A corrosion-resistant and antimicrobial coating was prepared on Mg ...Surface functionalization of magnesium(Mg)alloys is desired to obtain the surfaces with both improved corrosion resistance and antibacterial property.A corrosion-resistant and antimicrobial coating was prepared on Mg alloy surface by layer-by-layer(LbL)assembly of chitosan(CHI)and poly-L-glutamic acid(PGA)by electrostatic attraction.The functionalized surfaces of the Mg alloys were characterized by field-emission scanning electron microscopy(FE-SEM),Fourier transform infrared(FT-IR)spectroscopy and electrochemical tests.The bactericidal activity of the samples against Staphylococcus aureus was assessed by the zone of plate-counting method.The obtained coating on the Mg alloy substrates exhibits good corrosion resistance and antibacterial performance.展开更多
A chitosan/deoxyribonucleic acid(CHI/DNA)_(5)coating was constructed by layer-by-layer(LbL)assembly dip coating method with Mg(OH)_(2)coating as an inner protective layer on AZ31 alloy.X-ray diffractometry,X-ray photo...A chitosan/deoxyribonucleic acid(CHI/DNA)_(5)coating was constructed by layer-by-layer(LbL)assembly dip coating method with Mg(OH)_(2)coating as an inner protective layer on AZ31 alloy.X-ray diffractometry,X-ray photoelectron spectrometry,Fourier transform infrared spectroscopy and field-emission scanning electron microscopy were utilized to represent the chemical compositions and surface morphologies of the coatings.Electrochemical tests and hydrogen evolution measurements were implemented to confirm the good corrosion resistance of the composite coating in artificial body fluid.Antimicrobial activity of the composite coatings was tested via the plate-counting method,and the cytotoxicity of the samples was appraised by MTT assay and Live/dead staining.A double action was put into effect for the composite coating,which the inner Mg(OH)2 coating plays the part of physical barrier,and the outer(CHI/DNA)5 coating is employed as an inducer to fabricate a biocompatible Ca-P corrosion product coating during immersion,making up for its thin thickness.Otherwise,the composite coating is also beneficial for the growth of bone,resulting from the biomineralization effect of the outer polyelectrolyte multilayer.The good antibacterial property of the(CHI/DNA)5/Mg(OH)2 coating is ascribed to the contact-killing strength of CHI.Thus,the obtained(CHI/DNA)5/Mg(OH)2 coating has a wide application prospect in the field of Mg-based bone implantation.展开更多
Capsulating guest into the nanometer voids of zeolites is a effective way to form novel host-guest material. In our work, stoichiometric SrAl2O4 : Eu2+, Dy3+ sol guest was prepared by sol-gel method and assembled into...Capsulating guest into the nanometer voids of zeolites is a effective way to form novel host-guest material. In our work, stoichiometric SrAl2O4 : Eu2+, Dy3+ sol guest was prepared by sol-gel method and assembled into the nanometer channels of zeolite ZSM-5 host through mechanical mixing, hydrothemial reaction and microwave heating reaction, respectively. After being reduced and diffused in a microwave muffle, the fluorescence spectra of the host-guest materials exhibit remarkable blue shifts in companison of that of SrAl2O4 : Eu2+, Dy3+ Some interesting phenomena in the assembled host-guest materials are that the after-low emission spectra exist two bands at about 400 nm and 517 nm and the relative strengths of these two hands can be adjusted by changing the assembly methods and the assembly concentration. These are attributed to the fact that the phosphor was capsuiated into the voids of zeolite ZSM-5 and generated the quantum size effect and the host-guest effect.展开更多
Low-temperature assembly of MXene nanosheets into three-dimensional(3D) robust aerogels addresses the crucial stability concern of the nano-building blocks during the fabrication process,which is of key importance for...Low-temperature assembly of MXene nanosheets into three-dimensional(3D) robust aerogels addresses the crucial stability concern of the nano-building blocks during the fabrication process,which is of key importance for transforming the fascinating properties at the nanoscale into the macroscopic scale for practical applications.Herein,suitable cross-linking agents(amino-propyltriethoxysilane,Mn^(2+),Fe^(2+),Zn^(2+),and Co^(2+)) as interfacial mediators to engineer the interlayer interactions are reported to realize the graphene oxide(GO)-assisted assembly of Ti_(3)C_(2)T_(x) MXene aerogel at room temperature.This elaborate aerogel construction not only suppresses the oxidation degradation of Ti_(3)C_(2)T_(x) but also generates porous aerogels with a high Ti_(3)C_(2)T_(x) content(87 wt%) and robustness,thereby guaranteeing the functional accessibility of Ti_(3)C_(2)T_(x) nanosheets and operational reliability as integrated functional materials.In combination with a further sulfur modification,the Ti_(3)C_(2)T_(x) aerogel electrode shows promising electrochemical performances as the freestanding anode for sodium-ion storage.Even at an ultrahigh loading mass of 12.3 mg cm^(-2),a pronounced areal capacity of 1.26 mAh cm^(-2) at a current density of 0.1 A g^(-1) has been achieved,which is of practical significance.This work conceptually suggests a new way to exert the utmost surface functionalities of MXenes in 3D monolithic form and can be an inspiring scaffold to promote the application of MXenes in different areas.展开更多
The layer by layer complexation technique of polymer and metal ion was successfully utilized to fabricate the ultrathin multilayer film of poly(3 thiophene acetic acid (PTAA) and Tb 3+ ion by dipping the subst...The layer by layer complexation technique of polymer and metal ion was successfully utilized to fabricate the ultrathin multilayer film of poly(3 thiophene acetic acid (PTAA) and Tb 3+ ion by dipping the substrates alternatively in polymer and Tb 3+ ion aqueous solutions. UV-vis measurement revealed that the absorbance has linearity with the bilayer number from layer to layer and the X ray photoelectron spectrum (XPS) confirmed the existence of Tb 3+ ion. The pH of both the polymer and TbCl 3 solutions influence the thickness dramatically while the concentration of the solutions is not so sensitive. The luminescent spectrum of the complex film shows the characteristic emission of Tb 3+ ion as well as the ligand indicating the formation of the complex.展开更多
Turbine blisks are assembled using blades,disks and casings.They can endure complex loads at a high temperature,high pressure and high speed.The safe operation of assembled structures depends on the reliability of eac...Turbine blisks are assembled using blades,disks and casings.They can endure complex loads at a high temperature,high pressure and high speed.The safe operation of assembled structures depends on the reliability of each component.Monte Carlo(MC)simulation is commonly used to analyze structural reliability,but this method needs to run thousands of computations.In order to assess the clearance reliability of assembled structures in an efficient and precise manner,the novel Kriging-based decomposed-coordinated(DC)(DCNK)approach is proposed by integrating the DC strategy,the Kriging model and the importance sampling-based Markov chain(MCIS)technique.In this method,the DC strategy is used to decompose a multi-objective problem into many single-objective problems.The relationships between these many single-objectives and the overall objective are then coordinated.The Kriging model is applied to establish the limit state functions of the single-objectives and multi-objective problems,while the MCIS method is used to assess the structural assembled clearance reliability.Moreover,a highly nonlinear complex compound function is first utilized to verify the DCNK model from a mathematical perspective.Then,the reliability of an aeroengine high-pressure turbine(HPT)blade-tip radial running clearance(BTRRC)is analyzed to validate the DCNK approach by considering thermo-structural interaction.The analytical results show that the reliability is 0.9976 when the allowance value of the BTTRC is 1.7650×10^(−3)m.Compared with different methodologies(including direct simulation,the classical Kriging model,and the weighted response surface method(WRSM)),the proposed method holds obvious advantages in computing time and precision,as well as simulation efficiency and precision.The efforts of this paper provide a useful approach to analyzing assembled clearance reliability and contribute to the development of structural reliability theory.展开更多
Gap junctions, consisting of connexins, allow the exchange of small molecules (<1 kD) between adjacent cells, thusproviding a mechanism for synchronizing the responses of groups of cells to environmental stimuli. C...Gap junctions, consisting of connexins, allow the exchange of small molecules (<1 kD) between adjacent cells, thusproviding a mechanism for synchronizing the responses of groups of cells to environmental stimuli. Connexin 31 is amember of the connexin family. Mutations on connexin 31 are associated with erythrokeratodermia variabilis, hearingimpairment and peripheral neuropathy. However, the pathological mechanism for connexin 31 mutants in these diseasesare still unknown. In this study, we analyzed the assembly, trafficking and metabolism of connexin 31 in HeLa cellsstably expressing connexin 31. Calcein transfer assay showed that calcein transfer was inhibited when cells weretreated with Brefeldin A or cytochalasin D, but not when treated with nocodazole or α-glycyrrhetinic acid, suggestingthat Golgi apparatus and actin filaments, but not microtubules, are crucial to the trafficking and assembly of connexin31, as well as the formation of gap junction intercellular communication by connexin 31. Additionally, α-glycyrrhetinicacid did not effectively inhibit gap junctional intercellular communication formed by connexin 31. Pulse-chase assayrevealed that connexin 31 had a half-life of about 6 h. Moreover, Western blotting and fluorescent staining demonstratedthat in HeLa cells stably expressing connexin 31, the amount of connexin 31 was significantly increased after these cellswere treated with proteasomal or lysosomal inhibitors. These findings indicate that connexin 31 was rapidly renewed,and possibly degraded by both proteasomal and lysosomal pathways.展开更多
A robust and green strategy for the selective upgrading of biomass-derived platform chemicals towards highly valuable products is important for the sustainable development.Herein,the efficient electrocatalytic oxidati...A robust and green strategy for the selective upgrading of biomass-derived platform chemicals towards highly valuable products is important for the sustainable development.Herein,the efficient electrocatalytic oxidation of biomass-derived furfuryl alcohol(FFA)into furoic acid(FurAc)catalyzed by the electrodeposited non-precious NiFe microflowers was successfully reached under the low temperature and ambient pressure.The 3D hierarchical NiFe microflowers assembled from ultrathin nanosheets were controllably synthesized by the electrodeposition method and uniformly grown on carbon fiber paper(CFP).Electrochemical analysis confirmed that NiFe nanosheets more preferred in the selective oxidation of FFA(FFAOR)than oxygen evolution reaction(OER).The linear sweep voltammetry(LSV)in FFAOR displayed a clear decrease towards lower potential,resulting in 30 mV reduction of overpotential at 20 mA cm^(-2) compared with that of OER.The optimal catalyst Ni_(1)Fe_(2) nanosheets exhibited the highest selectivity of FurAc(94.0%)and 81.4%conversion of FFA within 3 h.Besides,the influence of various reaction parameters on FFAOR was then explored in details.After that,the reaction pathway was investigated and rationally proposed.The outstanding performance for FFAOR can be ascribed to the unique structure of 3D flower-like NiFe nanosheets and oxygen vacancies,resulting in large exposure of active sites,faster electron transfer and enhanced adsorption of reactants.Our findings highlight a facile and convenient mean with a promising green future,which is promising for processing of various biomass-derived platform chemicals into value-added products.展开更多
Deep learning accelerators(DLAs)have been proved to be efficient computational devices for processing deep learning algorithms.Various DLA architectures are proposed and applied to different applications and tasks.How...Deep learning accelerators(DLAs)have been proved to be efficient computational devices for processing deep learning algorithms.Various DLA architectures are proposed and applied to different applications and tasks.However,for most DLAs,their programming interfaces are either difficult to use or not efficient enough.Most DLAs require programmers to directly write instructions,which is time-consuming and error-prone.Another prevailing programming interface for DLAs is high-performance libraries and deep learning frameworks,which are easy to be used and very friendly to users,but their high abstraction level limits their control capacity over the hardware resources thus compromises the efficiency of the accelerator.A design of the programming interface is for DLAs.First various existing DLAs and their programming methods are analyzed and a methodology for designing programming interface for DLAs is proposed,which is a high-level assembly language(called DLA-AL),assembler and runtime for DLAs.DLA-AL is composed of a low-level assembly language and a set of high-level blocks.It allows experienced experts to fully exploit the potential of DLAs and achieve near-optimal performance.Meanwhile,by using DLA-AL,end-users who have little knowledge of the hardware are able to develop deep learning algorithms on DLAs spending minimal programming efforts.展开更多
This study investigated the stability behaviour of molecular monolayer symmetric chemically modified tetraether lipids caldarchaeol-PO<sub>4</sub> on the amino-silanised silicon wafer using Langmuir-Blodge...This study investigated the stability behaviour of molecular monolayer symmetric chemically modified tetraether lipids caldarchaeol-PO<sub>4</sub> on the amino-silanised silicon wafer using Langmuir-Blodgett films, Self Assembling Monolayers (SAMs), ellipsometry, and atomic force microscopy (AFM). The monolayers of caldarchaeol-PO<sub>4 </sub>were stable on the solid surface amino-silanised silicon wafer. The organizations of molecular monolayers caldarchaeol-PO<sub>4</sub> by Langmuir-Blodgett method and SAMs have been analyzed. The surface of pressure in Langmuir-Blodgett processing is carried out monolayers caldarchaeol-PO<sub>4</sub> more flat island inhomogeneous. Another method of monolayers caldarchaeol-PO<sub>4</sub> by SAMs is showed a large flat domain. Monolayers caldarchaeol-PO<sub>4</sub> by Langmuir-Blodgett method seems to be stable and chemically resistant after washing with organic solvent and an additional treatment ultrasonification with various thickness lipids arround 2 nm to 6 nm. Conversely, monolayer caldarchaeol-PO<sub>4</sub> by SAMs appears fewer than monolayers caldarchaeol-PO<sub>4</sub> by Langmuir-Blodgett method, the thickness of various from 1 nm to 3 nm.展开更多
In order to acquire the dynamic characteristics of joint surfaces of complex assembled structures, a novel parameter identification technique was adopted. Virtual materials were introduced to simulate the stiffness an...In order to acquire the dynamic characteristics of joint surfaces of complex assembled structures, a novel parameter identification technique was adopted. Virtual materials were introduced to simulate the stiffness and damping features of the joint surfaces between two different structures. Properties of the virtual materials, including elasticity modulus, density, and Poisson ratio, were gradually modified. At last, FEM modal results of the assembled structures are consistent with the experimental ones. This proves the feasibility of the simulating method and paves a solid foundation of the further research of the dynamic simulation.展开更多
The role of self assembled monolayer in inducing the crystal growth was investigated by X ray diffractions (XRD), and scanning electron microscopy (SEM). Results show that crystallization in the absence of monolayer r...The role of self assembled monolayer in inducing the crystal growth was investigated by X ray diffractions (XRD), and scanning electron microscopy (SEM). Results show that crystallization in the absence of monolayer results in a mixture of poorly crystallized calcium phosphates, including hydroxyapatite (HAP) and octacalcium phosphate (OCP), while the presence of self assembled monolayer gives rise to oriented and well crystallized HAP crystals. Moreover, the HAP crystal grows very quickly under the self assembled monolayer, whereas very little calcium phosphate crystals grow without the monolayer. It is rationalized that the hexadecylamine monolayer with high polarity and charged density leads to increase supersaturation and lower the interfacial energy, which attributes to the HAP crystals nucleation. On the other hand, the positive headgroups construct the ordered "recognized site" with distinct size and topology, which results in the oriented HAP crystals deposit.展开更多
To improve the performance of the 2 m telescope, the optimum design is applied to the telescope assemble. Referring to the telescope assemble with the dimetric truss, a group of reasonable sizes of the telescope assem...To improve the performance of the 2 m telescope, the optimum design is applied to the telescope assemble. Referring to the telescope assemble with the dimetric truss, a group of reasonable sizes of the telescope assemble are found by optimization methods and modal analysis, which will raise the resonant frequency by 4.21 %. As a result, the telescope assemble is less likely to resonate. Besides, the dynamic response module in ANSYS is utilized to analyze the modal type, harmonic vibration response and random vibration response of the telescope assemble. By the calculation of ANSYS, finite dement analysis (FEA) method proves that the performance of the telescope assemble is mildly enhanced by means of optimum design.展开更多
The reaction of 2,6-diformyl-4-methylphenol, ethylenediamine and Cu(Ⅱ) in the proportion of 3:2:2 yields a new tetranuclear copper(Ⅱ) complex, [Cu2L]2(ClO4)2.2H2O(H3L= N,N'-bis(4-(3'-formyl-5'-methylsa...The reaction of 2,6-diformyl-4-methylphenol, ethylenediamine and Cu(Ⅱ) in the proportion of 3:2:2 yields a new tetranuclear copper(Ⅱ) complex, [Cu2L]2(ClO4)2.2H2O(H3L= N,N'-bis(4-(3'-formyl-5'-methylsalicyclidene)iminoethyl)-4-methyl-2,6-bimethyliminophenol). The complex has been characterized by ES-MS, IR and X-ray diffraction analysis, and its crystal crystallizes in the triclinic system, space group P1 with a = 10.8673(11), b = 12.0829(12), c = 14.4834(15) А, α= 111.946(2), β= 105.828(2), γ = 99.583(2)°,V= 1618.5(3) А^3, Dc = 1.605 g/cm^3, Z = 2, Mr = 1564.26, F(000) = 800.0,μ(MoKa) = 1.460/mm, S = 1.063, R = 0.0612 and wR = 0.1163 for 6245 observed reflections (I 〉 2σ(I)). The complex is a dimer of dinuclear copper(Ⅱ) acylic enantiomorph subunit [Cu2L]ClO4.H_2O, held together by π…π weak coordination and hydrogen bonding interactions. In addition, the π…π interactions related to phenyl moieties as well as CH=N…π interactions were also found to stabilize the supramolecular architectures in the solid state.展开更多
In this paper, the synthesis and characterization of a triarylpyrazoline modified four-H-bonded molecular duplex are described. Its molecular structure has been confirmed by ^1H NMR and ESI-MS. The duplex emits strong...In this paper, the synthesis and characterization of a triarylpyrazoline modified four-H-bonded molecular duplex are described. Its molecular structure has been confirmed by ^1H NMR and ESI-MS. The duplex emits strong pure blue light peaking at 448 and 452 nm under UV photoexcitation in solution and solid state, respectively, and its relative photoluminescence quantum efficiency in solution is determined as 0.778 using quinine sulfate as reference. In concentration of 〉40 mmol/L, the duplex can gelate DMSO, and the organogel formed shows good pure blue photoluminescence too. This novel duplex, for its well-defined structure and efficient photoluminescence property, is a prospective candidate for pure blue electroluminescent emitter.展开更多
基金the Scientific Technology R&D Project of CCCC Asset Management Co.,Ltd.(RP2022015294&RP2022015296).
文摘Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically time-consuming.To address these issues,this study proposes a new technological method to design and prepare a high-performance assembled asphalt concrete block for fast repair of the potholes.A series of composite modified asphalt binders with 10%crumb rubber(CR)and different dosages(0%,1%,3%,5%)of polyurethane(PU)are examined to determine the optimized binder.Subsequently,the corresponding asphalt mixtures are prepared for further comparison and assessment of engineering properties,such as moistureinduced damage,high-temperature deformation,and low-temperature cracking characteristics.The test results show that PU can significantly improve the high-temperature performance and hardness of(crumb rubber modified asphalt)CRMA binder;3%PU contributes allowing the resistance of CRMA mixture to moisture-induced damage at higher levels,particularly under water whole immersion;as 3%PU is added,the high-temperature rutting deformation resistance of the CRMA mixture increases significantly,and the low-temperature anti-cracking properties are also improved slightly.Therefore,the innovatively designed high-quality assembled fast-repairing asphalt concrete block is recommended as an appropriate option for highway maintenance.
基金supported in part by the Key Research Projects of Higher Education Institutions in Henan Province(Grant No.24A560021)in part by the Henan Postdoctoral Foundation(Grant No.202102015).
文摘Segmentally assembled bridges are increasinglyfinding engineering applications in recent years due to their unique advantages,especially as urban viaducts.Vehicle loads are one of the most important variable loads acting on bridge structures.Accordingly,the influence of overloaded vehicles on existing assembled bridge structures is an urgent concern at present.This paper establishes thefinite element model of the segmentally assembled bridge based on ABAQUS software and analyzes the influence of vehicle overload on an assembled girder bridge struc-ture.First,afinite element model corresponding to the target bridge is established based on ABAQUS software,and the load is controlled to simulate vehicle movement in each area of the traveling zone at different times.Sec-ond,the key cross-sections of segmental girder bridges are monitored in real time based on the force character-istics of continuous girder bridges,and they are compared with the simulation results.Finally,a material damage ontology model is introduced,and the structural damage caused by different overloading rates is compared and analyzed.Results show that thefinite element modeling method is accurate by comparing with on-site measured data,and it is suitable for the numerical simulation of segmental girder bridges;Dynamic sensors installed at 1/4L,1/2L,and 3/4L of the segmental girder main beams could be used to identify the dynamic response of segmental girder bridges;The bottom plate of the segmental girder bridge is mostly damaged at the position where the length of the precast beam section changes and the midspan position.With the increase in load,damage in the direction of the bridge develops faster than that in the direction of the transverse bridge.Thefindings of this study can guide maintenance departments in the management and maintenance of bridges and vehicles.
文摘As an efficient,environmentally friendly,energy-saving construction method,assembled buildings are now widely used in campus building construction.Modular design thinking is system-based design thinking,and its application to the design of an assembled teaching building project will comprehensively improve the rationality of the teaching building and component design.The paper focuses on the application of modular design thinking in assembled teaching building design,aiming to provide references for China’s architectural design units,giving full play to the advantages of modular design thinking in future teaching building design projects,and enhancing the level of design,for the construction of the teaching building and the basis of the technical guarantee.
基金Project(2014TDJH104)supported by Shandong University of Science and Technology(SDUST)Research FundChina+3 种基金Project(2013RCJJ006)supported by Scientific Research Foundation of Shandong University of Science and Technology for Recruited TalentsChinaProject(BS2013CL009)supported by Scientific Research Foundation of Shandong for Outstanding Young ScientistChina
文摘To enhance the corrosion resistance of magnesium(Mg) alloy and to impart its surface with antibacterial functionality for inhibiting biofilm formation and biocorrosion, Mg(OH)2 films were fabricated on AZ31 magnesium alloy substrates by an in-situ hydrothermal method and well-defined multilayer coatings, consisting of gentamicin sulfate(GS) and poly(sodium 4-styrene sulfonate)(PSS), were prepared via layer-by-layer(Lb L) assembly. The morphologies, chemical compositions and corrosion resistance of the obtained(PSS/GS)n/Mg sample were investigated using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, electrochemical methods and immersion tests. Finally, the bactericidal activity of(PSS/GS)n/Mg samples against Staphylococcus aureus was assessed by the zone of inhibition methods and plate-counting method. The so-synthesized composite coating on the Mg alloy substrates exhibits good corrosion resistance and antibacterial performance, which make them attractive as coatings for medical implanted devices.
基金Projects(51375177,U1401249,51405161)supported by the National Natural Science Foundation of ChinaProject(2014M560659)supported by the Postdoctoral Science Foundation of ChinaProject(2014B090901065)supported by the Science and Technology Planning Project for Industry-University-Research Cooperation in Guangdong Province,China
文摘This work aims to improve the thermal performance of a light emitting diode(LED) module by employing a novelly assembled heat pipe heat sink. The heat pipe was embedded into the heat sink by a phase change expansion assembly(PCEA) process, which was developed by both finite element(FE) analysis and experiments. Heat transfer performance and optical performance of the LED modules were experimentally investigated and discussed. Compared to the LED module with a traditionally assembled heat pipe heat sink, the LED module employing the PCEA process exhibits about 20% decrease in the thermal resistance from the MCPCB to the heat pipe. The junction temperature is 4% lower and the luminous flux is 2% higher. The improvement in the thermal and optical performance is important to the high power LED applications.
基金Projects(51571134,51601108)supported by the National Natural Science Foundation of ChinaProject(2013RCJJ006)supported by the Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents,China+1 种基金Project(2016ZRB01A62)supported by the Natural Science Foundation of Shandong Province,ChinaProject(2014TDJH104)supported by Shandong University of Science and Technology Research Fund,China
文摘Surface functionalization of magnesium(Mg)alloys is desired to obtain the surfaces with both improved corrosion resistance and antibacterial property.A corrosion-resistant and antimicrobial coating was prepared on Mg alloy surface by layer-by-layer(LbL)assembly of chitosan(CHI)and poly-L-glutamic acid(PGA)by electrostatic attraction.The functionalized surfaces of the Mg alloys were characterized by field-emission scanning electron microscopy(FE-SEM),Fourier transform infrared(FT-IR)spectroscopy and electrochemical tests.The bactericidal activity of the samples against Staphylococcus aureus was assessed by the zone of plate-counting method.The obtained coating on the Mg alloy substrates exhibits good corrosion resistance and antibacterial performance.
基金This work was supported by the National Natural Sci-ence Foundation of China(51571134)Shandong Provincial Natural Science Foundation(ZR2017BEM002)Shan-dong University of Science and Technology Research Fund(2014TDJH104).
文摘A chitosan/deoxyribonucleic acid(CHI/DNA)_(5)coating was constructed by layer-by-layer(LbL)assembly dip coating method with Mg(OH)_(2)coating as an inner protective layer on AZ31 alloy.X-ray diffractometry,X-ray photoelectron spectrometry,Fourier transform infrared spectroscopy and field-emission scanning electron microscopy were utilized to represent the chemical compositions and surface morphologies of the coatings.Electrochemical tests and hydrogen evolution measurements were implemented to confirm the good corrosion resistance of the composite coating in artificial body fluid.Antimicrobial activity of the composite coatings was tested via the plate-counting method,and the cytotoxicity of the samples was appraised by MTT assay and Live/dead staining.A double action was put into effect for the composite coating,which the inner Mg(OH)2 coating plays the part of physical barrier,and the outer(CHI/DNA)5 coating is employed as an inducer to fabricate a biocompatible Ca-P corrosion product coating during immersion,making up for its thin thickness.Otherwise,the composite coating is also beneficial for the growth of bone,resulting from the biomineralization effect of the outer polyelectrolyte multilayer.The good antibacterial property of the(CHI/DNA)5/Mg(OH)2 coating is ascribed to the contact-killing strength of CHI.Thus,the obtained(CHI/DNA)5/Mg(OH)2 coating has a wide application prospect in the field of Mg-based bone implantation.
文摘Capsulating guest into the nanometer voids of zeolites is a effective way to form novel host-guest material. In our work, stoichiometric SrAl2O4 : Eu2+, Dy3+ sol guest was prepared by sol-gel method and assembled into the nanometer channels of zeolite ZSM-5 host through mechanical mixing, hydrothemial reaction and microwave heating reaction, respectively. After being reduced and diffused in a microwave muffle, the fluorescence spectra of the host-guest materials exhibit remarkable blue shifts in companison of that of SrAl2O4 : Eu2+, Dy3+ Some interesting phenomena in the assembled host-guest materials are that the after-low emission spectra exist two bands at about 400 nm and 517 nm and the relative strengths of these two hands can be adjusted by changing the assembly methods and the assembly concentration. These are attributed to the fact that the phosphor was capsuiated into the voids of zeolite ZSM-5 and generated the quantum size effect and the host-guest effect.
基金This work was supported by the National Natural Science Foundation of China(52071137,51977071,51802040,and 21802020)the Science and Technology Innovation Program of Hunan Province(2021RC3066 and 2021RC3067)+1 种基金the Natural Science Foundation of Hunan Province(2020JJ3004 and 2020JJ4192)N.Zhang and X.Xie also acknowledge the financial support of the Fundamental Research Funds for the Central Universities.
文摘Low-temperature assembly of MXene nanosheets into three-dimensional(3D) robust aerogels addresses the crucial stability concern of the nano-building blocks during the fabrication process,which is of key importance for transforming the fascinating properties at the nanoscale into the macroscopic scale for practical applications.Herein,suitable cross-linking agents(amino-propyltriethoxysilane,Mn^(2+),Fe^(2+),Zn^(2+),and Co^(2+)) as interfacial mediators to engineer the interlayer interactions are reported to realize the graphene oxide(GO)-assisted assembly of Ti_(3)C_(2)T_(x) MXene aerogel at room temperature.This elaborate aerogel construction not only suppresses the oxidation degradation of Ti_(3)C_(2)T_(x) but also generates porous aerogels with a high Ti_(3)C_(2)T_(x) content(87 wt%) and robustness,thereby guaranteeing the functional accessibility of Ti_(3)C_(2)T_(x) nanosheets and operational reliability as integrated functional materials.In combination with a further sulfur modification,the Ti_(3)C_(2)T_(x) aerogel electrode shows promising electrochemical performances as the freestanding anode for sodium-ion storage.Even at an ultrahigh loading mass of 12.3 mg cm^(-2),a pronounced areal capacity of 1.26 mAh cm^(-2) at a current density of 0.1 A g^(-1) has been achieved,which is of practical significance.This work conceptually suggests a new way to exert the utmost surface functionalities of MXenes in 3D monolithic form and can be an inspiring scaffold to promote the application of MXenes in different areas.
文摘The layer by layer complexation technique of polymer and metal ion was successfully utilized to fabricate the ultrathin multilayer film of poly(3 thiophene acetic acid (PTAA) and Tb 3+ ion by dipping the substrates alternatively in polymer and Tb 3+ ion aqueous solutions. UV-vis measurement revealed that the absorbance has linearity with the bilayer number from layer to layer and the X ray photoelectron spectrum (XPS) confirmed the existence of Tb 3+ ion. The pH of both the polymer and TbCl 3 solutions influence the thickness dramatically while the concentration of the solutions is not so sensitive. The luminescent spectrum of the complex film shows the characteristic emission of Tb 3+ ion as well as the ligand indicating the formation of the complex.
基金This paper is supported by the National Natural Science Foundation of China(51875465)the Civil Aircraft Scientific Research Project.The authors would like to thank their generous supports.
文摘Turbine blisks are assembled using blades,disks and casings.They can endure complex loads at a high temperature,high pressure and high speed.The safe operation of assembled structures depends on the reliability of each component.Monte Carlo(MC)simulation is commonly used to analyze structural reliability,but this method needs to run thousands of computations.In order to assess the clearance reliability of assembled structures in an efficient and precise manner,the novel Kriging-based decomposed-coordinated(DC)(DCNK)approach is proposed by integrating the DC strategy,the Kriging model and the importance sampling-based Markov chain(MCIS)technique.In this method,the DC strategy is used to decompose a multi-objective problem into many single-objective problems.The relationships between these many single-objectives and the overall objective are then coordinated.The Kriging model is applied to establish the limit state functions of the single-objectives and multi-objective problems,while the MCIS method is used to assess the structural assembled clearance reliability.Moreover,a highly nonlinear complex compound function is first utilized to verify the DCNK model from a mathematical perspective.Then,the reliability of an aeroengine high-pressure turbine(HPT)blade-tip radial running clearance(BTRRC)is analyzed to validate the DCNK approach by considering thermo-structural interaction.The analytical results show that the reliability is 0.9976 when the allowance value of the BTTRC is 1.7650×10^(−3)m.Compared with different methodologies(including direct simulation,the classical Kriging model,and the weighted response surface method(WRSM)),the proposed method holds obvious advantages in computing time and precision,as well as simulation efficiency and precision.The efforts of this paper provide a useful approach to analyzing assembled clearance reliability and contribute to the development of structural reliability theory.
基金supported by "the National High Tech-nology Research and Development Program of China, No.2002BA711A07-03, 08the Major State Basic ResearchDevelopment Program of China, No. 2001CB510302 and2004CB518800the National Natural Science Foun-dation of China, No. 30370737.
文摘Gap junctions, consisting of connexins, allow the exchange of small molecules (<1 kD) between adjacent cells, thusproviding a mechanism for synchronizing the responses of groups of cells to environmental stimuli. Connexin 31 is amember of the connexin family. Mutations on connexin 31 are associated with erythrokeratodermia variabilis, hearingimpairment and peripheral neuropathy. However, the pathological mechanism for connexin 31 mutants in these diseasesare still unknown. In this study, we analyzed the assembly, trafficking and metabolism of connexin 31 in HeLa cellsstably expressing connexin 31. Calcein transfer assay showed that calcein transfer was inhibited when cells weretreated with Brefeldin A or cytochalasin D, but not when treated with nocodazole or α-glycyrrhetinic acid, suggestingthat Golgi apparatus and actin filaments, but not microtubules, are crucial to the trafficking and assembly of connexin31, as well as the formation of gap junction intercellular communication by connexin 31. Additionally, α-glycyrrhetinicacid did not effectively inhibit gap junctional intercellular communication formed by connexin 31. Pulse-chase assayrevealed that connexin 31 had a half-life of about 6 h. Moreover, Western blotting and fluorescent staining demonstratedthat in HeLa cells stably expressing connexin 31, the amount of connexin 31 was significantly increased after these cellswere treated with proteasomal or lysosomal inhibitors. These findings indicate that connexin 31 was rapidly renewed,and possibly degraded by both proteasomal and lysosomal pathways.
基金supported by Key Area Research and Development Program of Guangdong Province (2019B110209003)Guangdong Basic and Applied Basic Research Foundation (2019B1515120058,2020A1515011149)+2 种基金National Natural Science Foundation of China (22078374,21776324)National Key R&D Program of China (2018YFD0800703)National Ten Thousand Talent Plan,the Fundamental Research Funds for the Cornell University (19lgzd25)and Hundred Talent Plan (201602)from Sun Yat-sen University.
文摘A robust and green strategy for the selective upgrading of biomass-derived platform chemicals towards highly valuable products is important for the sustainable development.Herein,the efficient electrocatalytic oxidation of biomass-derived furfuryl alcohol(FFA)into furoic acid(FurAc)catalyzed by the electrodeposited non-precious NiFe microflowers was successfully reached under the low temperature and ambient pressure.The 3D hierarchical NiFe microflowers assembled from ultrathin nanosheets were controllably synthesized by the electrodeposition method and uniformly grown on carbon fiber paper(CFP).Electrochemical analysis confirmed that NiFe nanosheets more preferred in the selective oxidation of FFA(FFAOR)than oxygen evolution reaction(OER).The linear sweep voltammetry(LSV)in FFAOR displayed a clear decrease towards lower potential,resulting in 30 mV reduction of overpotential at 20 mA cm^(-2) compared with that of OER.The optimal catalyst Ni_(1)Fe_(2) nanosheets exhibited the highest selectivity of FurAc(94.0%)and 81.4%conversion of FFA within 3 h.Besides,the influence of various reaction parameters on FFAOR was then explored in details.After that,the reaction pathway was investigated and rationally proposed.The outstanding performance for FFAOR can be ascribed to the unique structure of 3D flower-like NiFe nanosheets and oxygen vacancies,resulting in large exposure of active sites,faster electron transfer and enhanced adsorption of reactants.Our findings highlight a facile and convenient mean with a promising green future,which is promising for processing of various biomass-derived platform chemicals into value-added products.
基金Supported by the National Key Research and Development Program of China(No.2017YFA0700902,2017YFB1003101)the 973 Program of China(No.2015CB358800)National Science and Technology Major Project(No.2018ZX01031102)
文摘Deep learning accelerators(DLAs)have been proved to be efficient computational devices for processing deep learning algorithms.Various DLA architectures are proposed and applied to different applications and tasks.However,for most DLAs,their programming interfaces are either difficult to use or not efficient enough.Most DLAs require programmers to directly write instructions,which is time-consuming and error-prone.Another prevailing programming interface for DLAs is high-performance libraries and deep learning frameworks,which are easy to be used and very friendly to users,but their high abstraction level limits their control capacity over the hardware resources thus compromises the efficiency of the accelerator.A design of the programming interface is for DLAs.First various existing DLAs and their programming methods are analyzed and a methodology for designing programming interface for DLAs is proposed,which is a high-level assembly language(called DLA-AL),assembler and runtime for DLAs.DLA-AL is composed of a low-level assembly language and a set of high-level blocks.It allows experienced experts to fully exploit the potential of DLAs and achieve near-optimal performance.Meanwhile,by using DLA-AL,end-users who have little knowledge of the hardware are able to develop deep learning algorithms on DLAs spending minimal programming efforts.
文摘This study investigated the stability behaviour of molecular monolayer symmetric chemically modified tetraether lipids caldarchaeol-PO<sub>4</sub> on the amino-silanised silicon wafer using Langmuir-Blodgett films, Self Assembling Monolayers (SAMs), ellipsometry, and atomic force microscopy (AFM). The monolayers of caldarchaeol-PO<sub>4 </sub>were stable on the solid surface amino-silanised silicon wafer. The organizations of molecular monolayers caldarchaeol-PO<sub>4</sub> by Langmuir-Blodgett method and SAMs have been analyzed. The surface of pressure in Langmuir-Blodgett processing is carried out monolayers caldarchaeol-PO<sub>4</sub> more flat island inhomogeneous. Another method of monolayers caldarchaeol-PO<sub>4</sub> by SAMs is showed a large flat domain. Monolayers caldarchaeol-PO<sub>4</sub> by Langmuir-Blodgett method seems to be stable and chemically resistant after washing with organic solvent and an additional treatment ultrasonification with various thickness lipids arround 2 nm to 6 nm. Conversely, monolayer caldarchaeol-PO<sub>4</sub> by SAMs appears fewer than monolayers caldarchaeol-PO<sub>4</sub> by Langmuir-Blodgett method, the thickness of various from 1 nm to 3 nm.
文摘In order to acquire the dynamic characteristics of joint surfaces of complex assembled structures, a novel parameter identification technique was adopted. Virtual materials were introduced to simulate the stiffness and damping features of the joint surfaces between two different structures. Properties of the virtual materials, including elasticity modulus, density, and Poisson ratio, were gradually modified. At last, FEM modal results of the assembled structures are consistent with the experimental ones. This proves the feasibility of the simulating method and paves a solid foundation of the further research of the dynamic simulation.
文摘The role of self assembled monolayer in inducing the crystal growth was investigated by X ray diffractions (XRD), and scanning electron microscopy (SEM). Results show that crystallization in the absence of monolayer results in a mixture of poorly crystallized calcium phosphates, including hydroxyapatite (HAP) and octacalcium phosphate (OCP), while the presence of self assembled monolayer gives rise to oriented and well crystallized HAP crystals. Moreover, the HAP crystal grows very quickly under the self assembled monolayer, whereas very little calcium phosphate crystals grow without the monolayer. It is rationalized that the hexadecylamine monolayer with high polarity and charged density leads to increase supersaturation and lower the interfacial energy, which attributes to the HAP crystals nucleation. On the other hand, the positive headgroups construct the ordered "recognized site" with distinct size and topology, which results in the oriented HAP crystals deposit.
基金the Ministerial Level Advanced Rearch Foundation (304030401)
文摘To improve the performance of the 2 m telescope, the optimum design is applied to the telescope assemble. Referring to the telescope assemble with the dimetric truss, a group of reasonable sizes of the telescope assemble are found by optimization methods and modal analysis, which will raise the resonant frequency by 4.21 %. As a result, the telescope assemble is less likely to resonate. Besides, the dynamic response module in ANSYS is utilized to analyze the modal type, harmonic vibration response and random vibration response of the telescope assemble. By the calculation of ANSYS, finite dement analysis (FEA) method proves that the performance of the telescope assemble is mildly enhanced by means of optimum design.
基金Supported by the key Foundation of the Education Department of Hubei Province (No. D20081503)the foundation of the innovative group of the Education Department of Hubei Province (T200802)
文摘The reaction of 2,6-diformyl-4-methylphenol, ethylenediamine and Cu(Ⅱ) in the proportion of 3:2:2 yields a new tetranuclear copper(Ⅱ) complex, [Cu2L]2(ClO4)2.2H2O(H3L= N,N'-bis(4-(3'-formyl-5'-methylsalicyclidene)iminoethyl)-4-methyl-2,6-bimethyliminophenol). The complex has been characterized by ES-MS, IR and X-ray diffraction analysis, and its crystal crystallizes in the triclinic system, space group P1 with a = 10.8673(11), b = 12.0829(12), c = 14.4834(15) А, α= 111.946(2), β= 105.828(2), γ = 99.583(2)°,V= 1618.5(3) А^3, Dc = 1.605 g/cm^3, Z = 2, Mr = 1564.26, F(000) = 800.0,μ(MoKa) = 1.460/mm, S = 1.063, R = 0.0612 and wR = 0.1163 for 6245 observed reflections (I 〉 2σ(I)). The complex is a dimer of dinuclear copper(Ⅱ) acylic enantiomorph subunit [Cu2L]ClO4.H_2O, held together by π…π weak coordination and hydrogen bonding interactions. In addition, the π…π interactions related to phenyl moieties as well as CH=N…π interactions were also found to stabilize the supramolecular architectures in the solid state.
基金supported by the Foundation of Science and Technology Bureau,Sichuan Province(No. 2006j13-141)the National Natural Science Foundation of China(No.20672076).
文摘In this paper, the synthesis and characterization of a triarylpyrazoline modified four-H-bonded molecular duplex are described. Its molecular structure has been confirmed by ^1H NMR and ESI-MS. The duplex emits strong pure blue light peaking at 448 and 452 nm under UV photoexcitation in solution and solid state, respectively, and its relative photoluminescence quantum efficiency in solution is determined as 0.778 using quinine sulfate as reference. In concentration of 〉40 mmol/L, the duplex can gelate DMSO, and the organogel formed shows good pure blue photoluminescence too. This novel duplex, for its well-defined structure and efficient photoluminescence property, is a prospective candidate for pure blue electroluminescent emitter.