Recent advancements in additive manufacturing(AM)have revolutionized the design and production of complex engineering microstructures.Despite these advancements,their mathematical modeling and computational analysis r...Recent advancements in additive manufacturing(AM)have revolutionized the design and production of complex engineering microstructures.Despite these advancements,their mathematical modeling and computational analysis remain significant challenges.This research aims to develop an effective computational method for analyzing the free vibration of functionally graded(FG)microplates under high temperatures while resting on a Pasternak foundation(PF).This formulation leverages a new thirdorder shear deformation theory(new TSDT)for improved accuracy without requiring shear correction factors.Additionally,the modified couple stress theory(MCST)is incorporated to account for sizedependent effects in microplates.The PF is characterized by two parameters including spring stiffness(k_(w))and shear layer stiffness(k_(s)).To validate the proposed method,the results obtained are compared with those of the existing literature.Furthermore,numerical examples explore the influence of various factors on the high-temperature free vibration of FG microplates.These factors include the length scale parameter(l),geometric dimensions,material properties,and the presence of the elastic foundation.The findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments.In addition,the findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments.In addition,the results of this research will have great potential in military and defense applications such as components of submarines,fighter aircraft,and missiles.展开更多
This work develops a Hermitian C^(2) differential reproducing kernel interpolation meshless(DRKIM)method within the consistent couple stress theory(CCST)framework to study the three-dimensional(3D)microstructuredepend...This work develops a Hermitian C^(2) differential reproducing kernel interpolation meshless(DRKIM)method within the consistent couple stress theory(CCST)framework to study the three-dimensional(3D)microstructuredependent static flexural behavior of a functionally graded(FG)microplate subjected to mechanical loads and placed under full simple supports.In the formulation,we select the transverse stress and displacement components and their first-and second-order derivatives as primary variables.Then,we set up the differential reproducing conditions(DRCs)to obtain the shape functions of the Hermitian C^(2) differential reproducing kernel(DRK)interpolant’s derivatives without using direct differentiation.The interpolant’s shape function is combined with a primitive function that possesses Kronecker delta properties and an enrichment function that constituents DRCs.As a result,the primary variables and their first-and second-order derivatives satisfy the nodal interpolation properties.Subsequently,incorporating ourHermitianC^(2)DRKinterpolant intothe strong formof the3DCCST,we develop a DRKIM method to analyze the FG microplate’s 3D microstructure-dependent static flexural behavior.The Hermitian C^(2) DRKIM method is confirmed to be accurate and fast in its convergence rate by comparing the solutions it produces with the relevant 3D solutions available in the literature.Finally,the impact of essential factors on the transverse stresses,in-plane stresses,displacements,and couple stresses that are induced in the loaded microplate is examined.These factors include the length-to-thickness ratio,the material length-scale parameter,and the inhomogeneity index,which appear to be significant.展开更多
The modified couple stress theory(MCST)is applied to analyze axisymmetric bending and buckling behaviors of circular microplates with sinusoidal shear deformation theory.The differential governing equations and bounda...The modified couple stress theory(MCST)is applied to analyze axisymmetric bending and buckling behaviors of circular microplates with sinusoidal shear deformation theory.The differential governing equations and boundary conditions are derived through the principle of minimum total potential energy,and expressed in nominal form with the introduced nominal variables.With the application of generalized differential quadrature method(GDQM),both the differential governing equations and boundary conditions are expressed in discrete form,and a set of linear equations are obtained.The bending deflection can be obtained through solving the linear equations,while buckling loads can be determined through solving general eigenvalue problems.The influence of material length scale parameter and plate geometrical dimensions on the bending deflection and buckling loads of circular microplates is investigated numerically for different boundary conditions.展开更多
Tin halide perovskites recently have attracted extensive research attention due to their similar electronic and band structures but non-toxicity compared with their lead analogues. In this work, we prepare high-qualit...Tin halide perovskites recently have attracted extensive research attention due to their similar electronic and band structures but non-toxicity compared with their lead analogues. In this work, we prepare high-quality CsSnX_(3)(X=Br,I) microplates with lateral sizes of around 1–4 μm by chemical vapor deposition and investigate their low-temperature photoluminescence(PL) properties. A remarkable splitting of PL peaks of the CsSnBr_(3)microplate is observed at low temperatures. Besides the possible structural phase transition at below 70 K, the multi-peak fittings using Gauss functions and the power-dependent saturation phenomenon suggest that the PL could also be influenced by the conversion from the emission of bound excitons into free excitons. With the increase of temperature, the peak position shows a blueshift tendency for CsSnI_(3), which is governed by thermal expansion. However, the peak position of the CsSnBr3microplate exhibits a transition from redshift to blueshift at ~160 K. The full width at half maximum of CsSnX_(3)broadens with increasing temperature, and the fitting results imply that longitudinal optical phonons dominate the electron–phonon coupling and the coupling strength is much more robust in CsSnBr3than in CsSnI_(3). The PL intensity of CsSnX_(3)microplates is suppressed due to the enhanced non-radiative relaxation and exciton dissociation competing with radiative recombination. According to the Arrhenius law, the exciton binding energy of CsSnBr_(3)is ~38.4 meV, slightly smaller than that of CsSnI_(3).展开更多
Previous studies have shown that Eringen’s differential nonlocal model would lead to the ill-posed mathematical formulation for axisymmetric bending of circular microplates.Based on the nonlocal integral models along...Previous studies have shown that Eringen’s differential nonlocal model would lead to the ill-posed mathematical formulation for axisymmetric bending of circular microplates.Based on the nonlocal integral models along the radial and circumferential directions,we propose nonlocal integral polar models in this work.The proposed strainand stress-driven two-phase nonlocal integral polar models are applied to model the axisymmetric bending of circular microplates.The governing differential equations and boundary conditions(BCs)as well as constitutive constraints are deduced.It is found that the purely strain-driven nonlocal integral polar model turns to a traditional nonlocal differential polar model if the constitutive constraints are neglected.Meanwhile,the purely strain-and stress-driven nonlocal integral polar models are ill-posed,because the total number of the differential orders of the governing equations is less than that of the BCs plus constitutive constraints.Several nominal variables are introduced to simplify the mathematical expression,and the general differential quadrature method(GDQM)is applied to obtain the numerical solutions.The results from the current models(CMs)are compared with the data in the literature.It is clearly established that the consistent softening and toughening effects can be obtained for the strain-and stress-driven local/nonlocal integral polar models,respectively.The proposed two-phase local/nonlocal integral polar models(TPNIPMs)may provide an efficient method to design and optimize the plate-like structures for microelectro-mechanical systems.展开更多
This paper analyses the modal interactions in the nonlinear, size-dependent dynamics of geometrically imperfect microplates. Based on the modified couple stress theory,the equations of motion for the in-plane and out-...This paper analyses the modal interactions in the nonlinear, size-dependent dynamics of geometrically imperfect microplates. Based on the modified couple stress theory,the equations of motion for the in-plane and out-of-plane motions are obtained employing the von Kármán plate theory as well as Kirchhoff＇s hypotheses by means of the Lagrange equations. The equations of motions are solved using the pseudo-arclength continuation technique and direct timeintegration method. The system parameters are tuned to the values associated with modal interactions, and then nonlinear resonant responses and energy transfer are analysed.Nonlinear motion characteristics are shown in the form of frequency-response and force-response curves, time histories, phase-plane portraits, and fast Fourier transforms.展开更多
Small-scale lithospheric terranes (microplates) are important building-blocks of continental accretion but their presence is often obscured by subsequent plate-margin deformation events and by younger volcano-sediment...Small-scale lithospheric terranes (microplates) are important building-blocks of continental accretion but their presence is often obscured by subsequent plate-margin deformation events and by younger volcano-sedimentary covers. The geological fabric of the eastern Anatolian-Caucasian region results from the sequential accretion of lithospheric terranes against the southwestern continental margin of the Eurasian plate. Widespread sedimentary and volcanic covers conceal some of the principal tectonic boundaries in the region, and major uncertainties persist as to the number and extent of the various terranes.展开更多
Novel strategies for the simultaneous and portable detection of multiple analytes are highly favorable for clinical diagnosis and healthcare.Conventional colorimetric enzyme-linked immunosorbent assay(ELISA)is a widel...Novel strategies for the simultaneous and portable detection of multiple analytes are highly favorable for clinical diagnosis and healthcare.Conventional colorimetric enzyme-linked immunosorbent assay(ELISA)is a widely used laboratory technique for medical diagnostics,quality control,and research applications.However,nonspecific absorption of proteins may lead to a reduction of functional sites,resulting in high background and low sensitivity in ELISA.Herein,we report a simple method of functionalization of poly(methyl methacrylate)(PMMA)with polylysine to be used as the microfluidic microplate substrate for enhanced ELISA,enabling rapid,ultrasensitive,and multiplexed detection of infectious diseases.FTIR and fluorescence microscopy characterization confirmed high amine densities on polylysine-modified PMMA surface,resulting in high detection sensitivity of the colorimetric ELISA on the PMMA microdevice.The ultrasensitive polylysine-modified microplate can immobilize protein within 20 min and results of the assay can be viewed by the naked eye or scanned through a simple desktop scanner for quantitative analysis within 90 min.A sandwich-type immunoassay for the rapid and sensitive detection of immunoglobulin G(IgG),hepatitis B surface antigen(HBsAg),and hepatitis B core antigen(HBcAg)was demonstrated as a proof-of-concept for multiplexed detection.The limits of detection(LOD)of 200.0 pg/mL for IgG,180.0 pg/mL for HBsAg,and 300.0 pg/mL for HBcAg were achieved,without any specialized equipment like a microplate reader.The surface-modified microchip exhibited about 10-fold higher sensitivity than traditional microplates.This surface-modified microplate has tremendous potential as a point-ofcare multiplexed testing platform for many applications ranging from clinical diagnosis to environmental monitoring,particularly in resource-limited settings.展开更多
Hybrid organolead halide perovskites have attracted tremendous attention due to their recent success as high efficiency solar cell materials and their fascinating material properties uniquely suitable for optoelectron...Hybrid organolead halide perovskites have attracted tremendous attention due to their recent success as high efficiency solar cell materials and their fascinating material properties uniquely suitable for optoelectronic devices. However, the poor ambient and operational stability as well as the concern of lead toxicity greatly hamper their practical utilization. In this work, crystalline, all-inorganic and lead-free Cs_(3)Sb_(2)I_(9) perovskite microplates are successfully synthesized by a two-step chemical vapor deposition method. As compared with other typical lead-free perovskite materials, the Cs_(3)Sb_(2)I_(9) microplates demonstrate excellent optoelectronic properties, including substantial enhancements in the Stokes shift, exciton binding energy and electron-phonon coupling. Simple photoconductive devices fabricated using these microplates exhibit an ultra-fast response with the rise and decay time constants down to 96 and 58 µs, respectively. This respectable photoconductor performance can be regarded as a record among all the lead-free perovskite materials. Importantly, these photodetectors show superior thermal stability in a wide temperature range, capable to function reversibly between 80 and 380 K, indicating their robustness to operate under both low and high temperatures. All these results evidently suggest the technological potential of inorganic lead-free Cs_(3)Sb_(2)I_(9) perovskite microplates for next-generation high-performance optoelectronic devices.展开更多
Hexagonal and triangular Au microplates extending over an area of~12,000μm^(2) with thickness in the range 30-1000 nm have been synthesized using a single step thermolysis of(AuCl_(4))^(-)-tetraoctylammonium bromide ...Hexagonal and triangular Au microplates extending over an area of~12,000μm^(2) with thickness in the range 30-1000 nm have been synthesized using a single step thermolysis of(AuCl_(4))^(-)-tetraoctylammonium bromide complex in air.The microplates are self-supporting and can be easily manipulated using a sharp pin,a property which enables them to serve as substrates for living cells.The microplate surface is non-toxic to living cells and can enhance the fluorescence signal from fluorophores residing within the cell by an order of magnitude.In addition,the microplates are smooth and single-crystalline,and ideal as microscopy substrates and molecular electrodes.The growth of the microplates in the initial stages is interesting in that they seem to grow perpendicular to the substrate,as evidenced by in situ microscopy.展开更多
Titanium dioxide(Ti O_2) is widely employed as a solid photocatalyst for solar energy conversion and environmental remediation. The ability to construct porous Ti O_2 with controlled particle size and narrowed bandgap...Titanium dioxide(Ti O_2) is widely employed as a solid photocatalyst for solar energy conversion and environmental remediation. The ability to construct porous Ti O_2 with controlled particle size and narrowed bandgap is an essential requirement for the design of highly efficient and recyclable photocatalysts. Here, we report a templatefree acetic acid induced method for the synthesis of visiblelight responsive carbon-doped Ti O_2 microplates with high crystallinity and mesoporous structure. It is shown that the electron-withdrawing bidentate carboxylate ligands derived from acetic acid can narrow the bandgap of Ti O_2(1.84 e V)substantially. Moreover, the resultant microplate photocatalysts exhibit excellent photocatalytic efficiency and solid–liquid separation performance, which will be beneficial for future industrial applications.展开更多
Viral diseases are an important threat to crop yield,as they are responsible for losses greater than US$30 billion annually.Thus,understanding the dynamics of virus propagation within plant cells is essential for devi...Viral diseases are an important threat to crop yield,as they are responsible for losses greater than US$30 billion annually.Thus,understanding the dynamics of virus propagation within plant cells is essential for devising effective control strategies.However,viruses are complex to propagate and quantify.Existing methodologies for viral quantification tend to be expensive and time-consuming.Here,we present a rapid cost-effective approach to quantify viral propagation using an engineered virus expressing a fluorescent reporter.Using a microplate reader,we measured viral protein levels and we validated our findings through comparison by western blot analysis of viral coat protein,the most common approach to quantify viral titer.Our proposed methodology provides a practical and accessible approach to studying virus-host interactions and could contribute to enhancing our understanding of plant virology.展开更多
Organic-inorganic hybrid perovskites attract considerable attention owing to their applications in high-efficiency solar cells and light emission. Compared with three-dimensional perovskites, two-dimensional （2D） la...Organic-inorganic hybrid perovskites attract considerable attention owing to their applications in high-efficiency solar cells and light emission. Compared with three-dimensional perovskites, two-dimensional （2D） layered hybrid perovskites have a higher exciton binding energy and potentially higher light- emission efficiency. The growth of high-quality crystalline 2D perovskites with a well-defined nanoscale morphology is desirable because they can be suitable building blocks for integrated optoelectronics and （nano）photonics. Herein, we report the facile solution growth of single-crystal microplates of 2D perovskites based on a 2-phenylethylammonium （C6HsCH2CH2NHG PEA） cation, （PEA）2PbX- （X = Br, I）, with a well-defined rectangular geometry and nanoscale thickness through a dissolution-recrystallization process. The crystal structures of （PEA）2PbX4 are first confirmed using single-crystal X-ray diffraction. A solution-phase transport-growth process is developed to grow microplates with a typical size of tens of micrometers and thickness of hundreds of nanometers on another clean substrate different from the substrate coated with lead-acetate precursor film. Surface-topography analysis suggests that the formation of the 2D microplates is likely driven by the wedding-cake growth mechanism. Through halide alloying, the photoluminescence emission of （PEA）2Pb（Br, I）4 perovskites with a narrow peak bandwidth is readily tuned from violet （-410 nm） to green （-530 nm）.展开更多
Bismuth oxychloride(BiOCl)square microplates were prepared via a facile hydrothermal method.The X-ray diffraction patterns of the samples reveal a tetragonal BiOCl phase,and the scanning electron microscopy images sho...Bismuth oxychloride(BiOCl)square microplates were prepared via a facile hydrothermal method.The X-ray diffraction patterns of the samples reveal a tetragonal BiOCl phase,and the scanning electron microscopy images show plate-like structures with large lateral size of 3~6μm and thickness in the range of 100~300 nm.The effects of surfactant,reaction temperature and duration on the morphology of BiOCl powders are systematically in-vestigated.The polar behavior of a BiOCl single-crystalline microplate is examined by using piezoresponse force microscopy evidenced over 80 pm displacement under 40 V bias voltage.In addition,the photoelectric performance of the BiOCl microplates is evaluated by using electrochemical workstation with three-electrode system,and large photocurrent densities(over 0.5μA/cm^(2))and fast photoresponse(0.7~1.1 s)are detected by applying both 365 nm monochromatic light and sunlight illumination.The surface potential changes of BiOCl microplate under different light condition,characterized by in-situ Kelvin probe force microscopy,further verify the separation ability of the photo-induced charge carriers.These findings would be beneficial for further design photocatalytic and piezocatalytic materials.展开更多
A new species of Microplitis Foerster 1862：Microplitis vitellipedis,sp.nov.（♀） is described from China,Fujian,Mt.Wuyi.The new species is similar to Microplitis changbaishana Song et Chen.but has the following diff...A new species of Microplitis Foerster 1862：Microplitis vitellipedis,sp.nov.（♀） is described from China,Fujian,Mt.Wuyi.The new species is similar to Microplitis changbaishana Song et Chen.but has the following differences：Microplitis vitllivipes sp.nov：T1 parallel or subparallel-sided;antennae with F12-15 loosely connected;hind coxae reddish yellow;body normal.Microplitis changbaishana Song et Chen：T1 slightly widened towards apex;antennae with F12-15 tightly connected;hind coxae yellowish beown;body stout.展开更多
During the Paleozoic, the Ordos area in the western North China Plate was located at the intersecting position of microplates and controlled by their interaction. The structural framework in the Ordos area, which unde...During the Paleozoic, the Ordos area in the western North China Plate was located at the intersecting position of microplates and controlled by their interaction. The structural framework in the Ordos area, which underwent transformations in the Ordovician, the Carboniferous and the Permian respectively, was dominated by the alternation of uplift and depression. The transformations of structural framework are utilized as the clues to investigate the microplates＇ interacting type and its response in the Ordos area. According to the regional structural evolution, the Ordos area is simplified into an isopachous, isotropic and elastic shell model, and under proposed various boundary conditions, three series of numerical simulations corresponding to the three structural transformations are carried out to determine the detailed tectonic constraints. Numerical simulations reveal that the structure of the uplift and depression, which is similar to the actual pattern, develops only under one special boundary condition in each of the three series, indicating that the structural framework responds to the unique tectonic background. The simulation results show that in the Early Paleozoic, the L-shaped paleouplift formed nearby the southwestern corner of the Ordos area because the intensity of the compressions in the southern and western boundaries resulting from the ocean-continent collisions was similar. In the Late Paleozoic, it evolved into continent-continent （or arc-continent） interaction in the southern and northern boundaries; in the preliminary stage of the interaction, since the interface between the North China Plate and the plates on the south and north was narrow, the relative acting force was little and the regional western boundary immobile, and the structural framework in the basin was characterized by the N-S trending slender-waist-shaped uplift; as the interface between the plates expanded gradually, the extrusive force in the southern and northern boundaries of the North China Plate increased, resulting in the paleogeographic divisions showing E-W trending, and, the western boundary of the basin was extruded westward due to the intense compression inducing the local NE trending of paleogeographic division in the central area. The simulation results further reflect that the symmetry of the uplift-depression pattern is restricted by that of the boundary conditions, suggesting that the Paleozoic structural transformations of the Ordos area under boundary constraints accord with the universal physical symmetrical principle.展开更多
A new method for the determination of antithrombotic activity of egg white protein hydrolysate （EWPH） was developed using a microplate reader. Reaction was carried out at 37℃and pH 7.2 with fibrinogen concentration...A new method for the determination of antithrombotic activity of egg white protein hydrolysate （EWPH） was developed using a microplate reader. Reaction was carried out at 37℃and pH 7.2 with fibrinogen concentration 0.1%. Microplate reading was conducted at 405 nm. Inhibition rate of EWPH on thrombin activity showed linearity （R2 = 0.9971）, when the inhibition rate was in the range of 10-90%. The lower limit of detection （LLD, at 99.7% probability） and the biological limit of detection （BLD, at 99.7% probability） of the method were 10.643 and 40 mg/mL, respectively. The repeatability standard deviation （R.S.D.） was 1.08%. The standard deviation of the method was ±0.027 AT-U.展开更多
A microtiter plate assay (MPA) for soluble reactive phosphorus (SRP) was applied to samples in overlying water and pore water as well as in three forms of environmental soil test phosphorus (P) types: water soluble ph...A microtiter plate assay (MPA) for soluble reactive phosphorus (SRP) was applied to samples in overlying water and pore water as well as in three forms of environmental soil test phosphorus (P) types: water soluble phosphorus (WSP),diluted calcium chloride extractable phosphorus (PCaCl2), and Olsen-P in the sediments of Taihu Lake, China, where potential P release in response to pH was analyzed. MPA for rapid P analysis was shown to be promising when applied on samples of natural water and sediment extracts. Concentrations of WSP and PCaCl2 in the sediments were much lower than those of Olsen-P. Olsen-P levels in the littoral sediments along the north coast of Meiliang Bay in Taihu Lake (80to 140 mg kg-1) were much higher than those in the mouth of the bay (less than 50 mg kg-1). The risk of P release in the mouth area of Meiliang Bay was lower than that in the north littoral zone with a risk of sediment P release induced by pH increases.展开更多
[Objectives] To screen the optimal extraction conditions of flavonoids from leaves of Paliurus ramosissimus( Lour.) Poir.,measure the content of flavonoids in leaves of P. ramosissimus. using the Microplate Reader,and...[Objectives] To screen the optimal extraction conditions of flavonoids from leaves of Paliurus ramosissimus( Lour.) Poir.,measure the content of flavonoids in leaves of P. ramosissimus. using the Microplate Reader,and provide experimental basis for the development of medicinal resources of P. ramosissimus. [Methods] The ultrasonic extraction method was adopted and orthogonal design was carried out to study the effects of ethanol concentration( A),ultrasonic time( B),the solid-to-liquid ratio( C) on the extraction of flavonoids from leaves of P. ramosissimus. The Microplate Reader was used to measure the content of flavonoids in leaves of P. ramosissimus. in different extraction conditions,P. ramosissimus. and the optimal extraction conditions were used to measure the content of flavonoids from leaves of P. ramosissimus.[Results]Effects of the ultrasonic extraction method on the extraction rate of flavonoids from leaves of P. ramosissimus: extraction times >ethanol concentration > Ultrasound time > solid-liquid ratio. The screened optimal extraction process was: ethanol concentration of 65%,the solid-to-liquid ratio of 1∶ 25,ultrasonic time of 2 h and extraction times Under this condition,the extraction rate of total flavonoids in leaves of P. ramosissimus. was 2. 56%. [Conclusions] This method is simple and feasibility,reliable,and suitable for rapid measurement with large samples.展开更多
Objective: To identify the impact of lamivudine on HBV e antigen (HBeAg) seroconversion and HBV DNA level, and the appearance of Tyr-Met-Asn-Asp (YMDD) resistants. Methods: Forty-seven hepatitis B patients were trea- ...Objective: To identify the impact of lamivudine on HBV e antigen (HBeAg) seroconversion and HBV DNA level, and the appearance of Tyr-Met-Asn-Asp (YMDD) resistants. Methods: Forty-seven hepatitis B patients were trea- ted with oral lamivudine. ALT level and HBeAg were detected in the treatment on the zero, 3rd, 6th and 9th month respectively. The levels of HBV DNA and YMDD resistants were analyzed with PCR mi- croplate hybridization-ELISA. Results: After 9 months of treatment, HBV DNA be- came negative and ALT level was normal in 74% pa- tients. Among these patients, 17% patients had HBeAg converted to negative and anti-HBe antibody positive, whereas another 15% patients showed HBeAg negative. YMDD resistants appeared in 19 % patients (9/47). One, three and five resistants were detected in the treatment on the 3rd, 6th and 9th month respectively. Conclusions: Most HBV DNA in serum became nega- tive after 9 months of treatment, and the rate of HBeAg seroconversion was 17% (HBV DNA level was lower than 100 pg/ml before treatment). YMDD resistants appeared in 19% patients.展开更多
文摘Recent advancements in additive manufacturing(AM)have revolutionized the design and production of complex engineering microstructures.Despite these advancements,their mathematical modeling and computational analysis remain significant challenges.This research aims to develop an effective computational method for analyzing the free vibration of functionally graded(FG)microplates under high temperatures while resting on a Pasternak foundation(PF).This formulation leverages a new thirdorder shear deformation theory(new TSDT)for improved accuracy without requiring shear correction factors.Additionally,the modified couple stress theory(MCST)is incorporated to account for sizedependent effects in microplates.The PF is characterized by two parameters including spring stiffness(k_(w))and shear layer stiffness(k_(s)).To validate the proposed method,the results obtained are compared with those of the existing literature.Furthermore,numerical examples explore the influence of various factors on the high-temperature free vibration of FG microplates.These factors include the length scale parameter(l),geometric dimensions,material properties,and the presence of the elastic foundation.The findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments.In addition,the findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments.In addition,the results of this research will have great potential in military and defense applications such as components of submarines,fighter aircraft,and missiles.
基金supported by a grant from the National Science and Technology Council of the Republic of China(Grant Number:MOST 112-2221-E-006-048-MY2).
文摘This work develops a Hermitian C^(2) differential reproducing kernel interpolation meshless(DRKIM)method within the consistent couple stress theory(CCST)framework to study the three-dimensional(3D)microstructuredependent static flexural behavior of a functionally graded(FG)microplate subjected to mechanical loads and placed under full simple supports.In the formulation,we select the transverse stress and displacement components and their first-and second-order derivatives as primary variables.Then,we set up the differential reproducing conditions(DRCs)to obtain the shape functions of the Hermitian C^(2) differential reproducing kernel(DRK)interpolant’s derivatives without using direct differentiation.The interpolant’s shape function is combined with a primitive function that possesses Kronecker delta properties and an enrichment function that constituents DRCs.As a result,the primary variables and their first-and second-order derivatives satisfy the nodal interpolation properties.Subsequently,incorporating ourHermitianC^(2)DRKinterpolant intothe strong formof the3DCCST,we develop a DRKIM method to analyze the FG microplate’s 3D microstructure-dependent static flexural behavior.The Hermitian C^(2) DRKIM method is confirmed to be accurate and fast in its convergence rate by comparing the solutions it produces with the relevant 3D solutions available in the literature.Finally,the impact of essential factors on the transverse stresses,in-plane stresses,displacements,and couple stresses that are induced in the loaded microplate is examined.These factors include the length-to-thickness ratio,the material length-scale parameter,and the inhomogeneity index,which appear to be significant.
基金supported in part by the National Natural Science Foundation of China(No.12172169)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘The modified couple stress theory(MCST)is applied to analyze axisymmetric bending and buckling behaviors of circular microplates with sinusoidal shear deformation theory.The differential governing equations and boundary conditions are derived through the principle of minimum total potential energy,and expressed in nominal form with the introduced nominal variables.With the application of generalized differential quadrature method(GDQM),both the differential governing equations and boundary conditions are expressed in discrete form,and a set of linear equations are obtained.The bending deflection can be obtained through solving the linear equations,while buckling loads can be determined through solving general eigenvalue problems.The influence of material length scale parameter and plate geometrical dimensions on the bending deflection and buckling loads of circular microplates is investigated numerically for different boundary conditions.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11974279, 12074311, 12004310, and 12261141662)。
文摘Tin halide perovskites recently have attracted extensive research attention due to their similar electronic and band structures but non-toxicity compared with their lead analogues. In this work, we prepare high-quality CsSnX_(3)(X=Br,I) microplates with lateral sizes of around 1–4 μm by chemical vapor deposition and investigate their low-temperature photoluminescence(PL) properties. A remarkable splitting of PL peaks of the CsSnBr_(3)microplate is observed at low temperatures. Besides the possible structural phase transition at below 70 K, the multi-peak fittings using Gauss functions and the power-dependent saturation phenomenon suggest that the PL could also be influenced by the conversion from the emission of bound excitons into free excitons. With the increase of temperature, the peak position shows a blueshift tendency for CsSnI_(3), which is governed by thermal expansion. However, the peak position of the CsSnBr3microplate exhibits a transition from redshift to blueshift at ~160 K. The full width at half maximum of CsSnX_(3)broadens with increasing temperature, and the fitting results imply that longitudinal optical phonons dominate the electron–phonon coupling and the coupling strength is much more robust in CsSnBr3than in CsSnI_(3). The PL intensity of CsSnX_(3)microplates is suppressed due to the enhanced non-radiative relaxation and exciton dissociation competing with radiative recombination. According to the Arrhenius law, the exciton binding energy of CsSnBr_(3)is ~38.4 meV, slightly smaller than that of CsSnI_(3).
基金Project supported by the National Natural Science Foundation of China(No.12172169)the Research Fund of State Key Laboratory of Mechanicsthe Priority Academic Program Development of Jiangsu Higher Education Institutions of China。
文摘Previous studies have shown that Eringen’s differential nonlocal model would lead to the ill-posed mathematical formulation for axisymmetric bending of circular microplates.Based on the nonlocal integral models along the radial and circumferential directions,we propose nonlocal integral polar models in this work.The proposed strainand stress-driven two-phase nonlocal integral polar models are applied to model the axisymmetric bending of circular microplates.The governing differential equations and boundary conditions(BCs)as well as constitutive constraints are deduced.It is found that the purely strain-driven nonlocal integral polar model turns to a traditional nonlocal differential polar model if the constitutive constraints are neglected.Meanwhile,the purely strain-and stress-driven nonlocal integral polar models are ill-posed,because the total number of the differential orders of the governing equations is less than that of the BCs plus constitutive constraints.Several nominal variables are introduced to simplify the mathematical expression,and the general differential quadrature method(GDQM)is applied to obtain the numerical solutions.The results from the current models(CMs)are compared with the data in the literature.It is clearly established that the consistent softening and toughening effects can be obtained for the strain-and stress-driven local/nonlocal integral polar models,respectively.The proposed two-phase local/nonlocal integral polar models(TPNIPMs)may provide an efficient method to design and optimize the plate-like structures for microelectro-mechanical systems.
文摘This paper analyses the modal interactions in the nonlinear, size-dependent dynamics of geometrically imperfect microplates. Based on the modified couple stress theory,the equations of motion for the in-plane and out-of-plane motions are obtained employing the von Kármán plate theory as well as Kirchhoff＇s hypotheses by means of the Lagrange equations. The equations of motions are solved using the pseudo-arclength continuation technique and direct timeintegration method. The system parameters are tuned to the values associated with modal interactions, and then nonlinear resonant responses and energy transfer are analysed.Nonlinear motion characteristics are shown in the form of frequency-response and force-response curves, time histories, phase-plane portraits, and fast Fourier transforms.
基金funded by a PRIN 2017-2020 project grant from the Italian Ministry of University and Research(MUR)we thank Paolo Ballato(University Roma Tre)and Magdala Tesauro(University of Trieste)for support during the projectChiara Civiero(University of Trieste)is thanked for sharing the GNSS compilation.
文摘Small-scale lithospheric terranes (microplates) are important building-blocks of continental accretion but their presence is often obscured by subsequent plate-margin deformation events and by younger volcano-sedimentary covers. The geological fabric of the eastern Anatolian-Caucasian region results from the sequential accretion of lithospheric terranes against the southwestern continental margin of the Eurasian plate. Widespread sedimentary and volcanic covers conceal some of the principal tectonic boundaries in the region, and major uncertainties persist as to the number and extent of the various terranes.
基金support from NIH/NIAID(R41AI162477)the U.S.NSF(IIP2122712 and CHE2216473)+7 种基金the Cancer Prevention and Research Institute of Texas(CPRIT,RP210165)the TTUHSC-UTEP Joint Seed Grant,and the AAFS Foundation Research Lucas grantthe prior financial support to our research from the NIH/NIAID(R21AI107415)the NIH/NIGMS(SC2GM105584)the NIH/NIMHD RCMI Pilot grant(5G12MD007593-22)the NIH Building Scholar Summer Sabbatical Award,the NSF(IIP1953841,IIP2052347,and DMR1827745)the DOT(CARTEEH)the Philadelphia Foundation,the Medical Center of the Americas Foundation(MCA)。
文摘Novel strategies for the simultaneous and portable detection of multiple analytes are highly favorable for clinical diagnosis and healthcare.Conventional colorimetric enzyme-linked immunosorbent assay(ELISA)is a widely used laboratory technique for medical diagnostics,quality control,and research applications.However,nonspecific absorption of proteins may lead to a reduction of functional sites,resulting in high background and low sensitivity in ELISA.Herein,we report a simple method of functionalization of poly(methyl methacrylate)(PMMA)with polylysine to be used as the microfluidic microplate substrate for enhanced ELISA,enabling rapid,ultrasensitive,and multiplexed detection of infectious diseases.FTIR and fluorescence microscopy characterization confirmed high amine densities on polylysine-modified PMMA surface,resulting in high detection sensitivity of the colorimetric ELISA on the PMMA microdevice.The ultrasensitive polylysine-modified microplate can immobilize protein within 20 min and results of the assay can be viewed by the naked eye or scanned through a simple desktop scanner for quantitative analysis within 90 min.A sandwich-type immunoassay for the rapid and sensitive detection of immunoglobulin G(IgG),hepatitis B surface antigen(HBsAg),and hepatitis B core antigen(HBcAg)was demonstrated as a proof-of-concept for multiplexed detection.The limits of detection(LOD)of 200.0 pg/mL for IgG,180.0 pg/mL for HBsAg,and 300.0 pg/mL for HBcAg were achieved,without any specialized equipment like a microplate reader.The surface-modified microchip exhibited about 10-fold higher sensitivity than traditional microplates.This surface-modified microplate has tremendous potential as a point-ofcare multiplexed testing platform for many applications ranging from clinical diagnosis to environmental monitoring,particularly in resource-limited settings.
基金This work was supported by the National Natural Science Foundation of China(Nos.11874351,11874352,51672229,and 61805237)the Hong Kong Scholars Program(No.XJ2019027)+2 种基金the General Research Fund(CityU 11204618)the Theme-based Research(No.T42-103/16-N)of the Research Grants Council of Hong Kong SAR,ChinaCityU SGP-9380076 and the Foshan Innovative and Entrepreneurial Research Team Program(No.2018IT100031).
文摘Hybrid organolead halide perovskites have attracted tremendous attention due to their recent success as high efficiency solar cell materials and their fascinating material properties uniquely suitable for optoelectronic devices. However, the poor ambient and operational stability as well as the concern of lead toxicity greatly hamper their practical utilization. In this work, crystalline, all-inorganic and lead-free Cs_(3)Sb_(2)I_(9) perovskite microplates are successfully synthesized by a two-step chemical vapor deposition method. As compared with other typical lead-free perovskite materials, the Cs_(3)Sb_(2)I_(9) microplates demonstrate excellent optoelectronic properties, including substantial enhancements in the Stokes shift, exciton binding energy and electron-phonon coupling. Simple photoconductive devices fabricated using these microplates exhibit an ultra-fast response with the rise and decay time constants down to 96 and 58 µs, respectively. This respectable photoconductor performance can be regarded as a record among all the lead-free perovskite materials. Importantly, these photodetectors show superior thermal stability in a wide temperature range, capable to function reversibly between 80 and 380 K, indicating their robustness to operate under both low and high temperatures. All these results evidently suggest the technological potential of inorganic lead-free Cs_(3)Sb_(2)I_(9) perovskite microplates for next-generation high-performance optoelectronic devices.
基金B.Radha thanks the Council of Scientific and Industrial Research,India for financial assistance.
文摘Hexagonal and triangular Au microplates extending over an area of~12,000μm^(2) with thickness in the range 30-1000 nm have been synthesized using a single step thermolysis of(AuCl_(4))^(-)-tetraoctylammonium bromide complex in air.The microplates are self-supporting and can be easily manipulated using a sharp pin,a property which enables them to serve as substrates for living cells.The microplate surface is non-toxic to living cells and can enhance the fluorescence signal from fluorophores residing within the cell by an order of magnitude.In addition,the microplates are smooth and single-crystalline,and ideal as microscopy substrates and molecular electrodes.The growth of the microplates in the initial stages is interesting in that they seem to grow perpendicular to the substrate,as evidenced by in situ microscopy.
基金supported by the National Natural Science Foundation of China(20966006)the Natural Science Foundation of the Inner Mongolia Autonomous Region(2014MS0218)the Program for Innovative Research Team in Universities of Inner Mongolia Autonomous Region(NMGIRT-A1603)
文摘Titanium dioxide(Ti O_2) is widely employed as a solid photocatalyst for solar energy conversion and environmental remediation. The ability to construct porous Ti O_2 with controlled particle size and narrowed bandgap is an essential requirement for the design of highly efficient and recyclable photocatalysts. Here, we report a templatefree acetic acid induced method for the synthesis of visiblelight responsive carbon-doped Ti O_2 microplates with high crystallinity and mesoporous structure. It is shown that the electron-withdrawing bidentate carboxylate ligands derived from acetic acid can narrow the bandgap of Ti O_2(1.84 e V)substantially. Moreover, the resultant microplate photocatalysts exhibit excellent photocatalytic efficiency and solid–liquid separation performance, which will be beneficial for future industrial applications.
基金Funding from Natural Sciences and Engineering Research Council of Canada award number RGPIN/4002-2020.
文摘Viral diseases are an important threat to crop yield,as they are responsible for losses greater than US$30 billion annually.Thus,understanding the dynamics of virus propagation within plant cells is essential for devising effective control strategies.However,viruses are complex to propagate and quantify.Existing methodologies for viral quantification tend to be expensive and time-consuming.Here,we present a rapid cost-effective approach to quantify viral propagation using an engineered virus expressing a fluorescent reporter.Using a microplate reader,we measured viral protein levels and we validated our findings through comparison by western blot analysis of viral coat protein,the most common approach to quantify viral titer.Our proposed methodology provides a practical and accessible approach to studying virus-host interactions and could contribute to enhancing our understanding of plant virology.
文摘Organic-inorganic hybrid perovskites attract considerable attention owing to their applications in high-efficiency solar cells and light emission. Compared with three-dimensional perovskites, two-dimensional （2D） layered hybrid perovskites have a higher exciton binding energy and potentially higher light- emission efficiency. The growth of high-quality crystalline 2D perovskites with a well-defined nanoscale morphology is desirable because they can be suitable building blocks for integrated optoelectronics and （nano）photonics. Herein, we report the facile solution growth of single-crystal microplates of 2D perovskites based on a 2-phenylethylammonium （C6HsCH2CH2NHG PEA） cation, （PEA）2PbX- （X = Br, I）, with a well-defined rectangular geometry and nanoscale thickness through a dissolution-recrystallization process. The crystal structures of （PEA）2PbX4 are first confirmed using single-crystal X-ray diffraction. A solution-phase transport-growth process is developed to grow microplates with a typical size of tens of micrometers and thickness of hundreds of nanometers on another clean substrate different from the substrate coated with lead-acetate precursor film. Surface-topography analysis suggests that the formation of the 2D microplates is likely driven by the wedding-cake growth mechanism. Through halide alloying, the photoluminescence emission of （PEA）2Pb（Br, I）4 perovskites with a narrow peak bandwidth is readily tuned from violet （-410 nm） to green （-530 nm）.
基金supported by the National Natural Science Foundation of China (Nos. 51872311, 51902331 and 11974250)the Shanghai International Science and Technology Cooperation Fund Project (No. 18520723200)+1 种基金the Science and Technology Commission of Shanghai Municipality (Nos. 19070502800 and 19ZR1464900)the Frontier Science Key Project of the Chinese Academy of Sciences (QYZDB-SSW-JSC027)
文摘Bismuth oxychloride(BiOCl)square microplates were prepared via a facile hydrothermal method.The X-ray diffraction patterns of the samples reveal a tetragonal BiOCl phase,and the scanning electron microscopy images show plate-like structures with large lateral size of 3~6μm and thickness in the range of 100~300 nm.The effects of surfactant,reaction temperature and duration on the morphology of BiOCl powders are systematically in-vestigated.The polar behavior of a BiOCl single-crystalline microplate is examined by using piezoresponse force microscopy evidenced over 80 pm displacement under 40 V bias voltage.In addition,the photoelectric performance of the BiOCl microplates is evaluated by using electrochemical workstation with three-electrode system,and large photocurrent densities(over 0.5μA/cm^(2))and fast photoresponse(0.7~1.1 s)are detected by applying both 365 nm monochromatic light and sunlight illumination.The surface potential changes of BiOCl microplate under different light condition,characterized by in-situ Kelvin probe force microscopy,further verify the separation ability of the photo-induced charge carriers.These findings would be beneficial for further design photocatalytic and piezocatalytic materials.
基金supported by the Digitization Construction of Insect Specimen of Nature Reserve from MST(2005DKA21404)
文摘A new species of Microplitis Foerster 1862：Microplitis vitellipedis,sp.nov.（♀） is described from China,Fujian,Mt.Wuyi.The new species is similar to Microplitis changbaishana Song et Chen.but has the following differences：Microplitis vitllivipes sp.nov：T1 parallel or subparallel-sided;antennae with F12-15 loosely connected;hind coxae reddish yellow;body normal.Microplitis changbaishana Song et Chen：T1 slightly widened towards apex;antennae with F12-15 tightly connected;hind coxae yellowish beown;body stout.
文摘During the Paleozoic, the Ordos area in the western North China Plate was located at the intersecting position of microplates and controlled by their interaction. The structural framework in the Ordos area, which underwent transformations in the Ordovician, the Carboniferous and the Permian respectively, was dominated by the alternation of uplift and depression. The transformations of structural framework are utilized as the clues to investigate the microplates＇ interacting type and its response in the Ordos area. According to the regional structural evolution, the Ordos area is simplified into an isopachous, isotropic and elastic shell model, and under proposed various boundary conditions, three series of numerical simulations corresponding to the three structural transformations are carried out to determine the detailed tectonic constraints. Numerical simulations reveal that the structure of the uplift and depression, which is similar to the actual pattern, develops only under one special boundary condition in each of the three series, indicating that the structural framework responds to the unique tectonic background. The simulation results show that in the Early Paleozoic, the L-shaped paleouplift formed nearby the southwestern corner of the Ordos area because the intensity of the compressions in the southern and western boundaries resulting from the ocean-continent collisions was similar. In the Late Paleozoic, it evolved into continent-continent （or arc-continent） interaction in the southern and northern boundaries; in the preliminary stage of the interaction, since the interface between the North China Plate and the plates on the south and north was narrow, the relative acting force was little and the regional western boundary immobile, and the structural framework in the basin was characterized by the N-S trending slender-waist-shaped uplift; as the interface between the plates expanded gradually, the extrusive force in the southern and northern boundaries of the North China Plate increased, resulting in the paleogeographic divisions showing E-W trending, and, the western boundary of the basin was extruded westward due to the intense compression inducing the local NE trending of paleogeographic division in the central area. The simulation results further reflect that the symmetry of the uplift-depression pattern is restricted by that of the boundary conditions, suggesting that the Paleozoic structural transformations of the Ordos area under boundary constraints accord with the universal physical symmetrical principle.
文摘A new method for the determination of antithrombotic activity of egg white protein hydrolysate （EWPH） was developed using a microplate reader. Reaction was carried out at 37℃and pH 7.2 with fibrinogen concentration 0.1%. Microplate reading was conducted at 405 nm. Inhibition rate of EWPH on thrombin activity showed linearity （R2 = 0.9971）, when the inhibition rate was in the range of 10-90%. The lower limit of detection （LLD, at 99.7% probability） and the biological limit of detection （BLD, at 99.7% probability） of the method were 10.643 and 40 mg/mL, respectively. The repeatability standard deviation （R.S.D.） was 1.08%. The standard deviation of the method was ±0.027 AT-U.
基金Project supported by the National Key Basic Research Support Foundation (NKBRSF) of China (No. 2002CB412304) the Chinese Academy of Sciences (No. KZCX1-SW-Ⅱ-32).
文摘A microtiter plate assay (MPA) for soluble reactive phosphorus (SRP) was applied to samples in overlying water and pore water as well as in three forms of environmental soil test phosphorus (P) types: water soluble phosphorus (WSP),diluted calcium chloride extractable phosphorus (PCaCl2), and Olsen-P in the sediments of Taihu Lake, China, where potential P release in response to pH was analyzed. MPA for rapid P analysis was shown to be promising when applied on samples of natural water and sediment extracts. Concentrations of WSP and PCaCl2 in the sediments were much lower than those of Olsen-P. Olsen-P levels in the littoral sediments along the north coast of Meiliang Bay in Taihu Lake (80to 140 mg kg-1) were much higher than those in the mouth of the bay (less than 50 mg kg-1). The risk of P release in the mouth area of Meiliang Bay was lower than that in the north littoral zone with a risk of sediment P release induced by pH increases.
基金Supported by Project of Sichuan Provincial Health Department(120385)Project of Sichuan Provincial Science and Technology Department(14JC0137)Project of Luzhou City Department of Science and Technology(2015LZCYDS09(2/8))
文摘[Objectives] To screen the optimal extraction conditions of flavonoids from leaves of Paliurus ramosissimus( Lour.) Poir.,measure the content of flavonoids in leaves of P. ramosissimus. using the Microplate Reader,and provide experimental basis for the development of medicinal resources of P. ramosissimus. [Methods] The ultrasonic extraction method was adopted and orthogonal design was carried out to study the effects of ethanol concentration( A),ultrasonic time( B),the solid-to-liquid ratio( C) on the extraction of flavonoids from leaves of P. ramosissimus. The Microplate Reader was used to measure the content of flavonoids in leaves of P. ramosissimus. in different extraction conditions,P. ramosissimus. and the optimal extraction conditions were used to measure the content of flavonoids from leaves of P. ramosissimus.[Results]Effects of the ultrasonic extraction method on the extraction rate of flavonoids from leaves of P. ramosissimus: extraction times >ethanol concentration > Ultrasound time > solid-liquid ratio. The screened optimal extraction process was: ethanol concentration of 65%,the solid-to-liquid ratio of 1∶ 25,ultrasonic time of 2 h and extraction times Under this condition,the extraction rate of total flavonoids in leaves of P. ramosissimus. was 2. 56%. [Conclusions] This method is simple and feasibility,reliable,and suitable for rapid measurement with large samples.
文摘Objective: To identify the impact of lamivudine on HBV e antigen (HBeAg) seroconversion and HBV DNA level, and the appearance of Tyr-Met-Asn-Asp (YMDD) resistants. Methods: Forty-seven hepatitis B patients were trea- ted with oral lamivudine. ALT level and HBeAg were detected in the treatment on the zero, 3rd, 6th and 9th month respectively. The levels of HBV DNA and YMDD resistants were analyzed with PCR mi- croplate hybridization-ELISA. Results: After 9 months of treatment, HBV DNA be- came negative and ALT level was normal in 74% pa- tients. Among these patients, 17% patients had HBeAg converted to negative and anti-HBe antibody positive, whereas another 15% patients showed HBeAg negative. YMDD resistants appeared in 19 % patients (9/47). One, three and five resistants were detected in the treatment on the 3rd, 6th and 9th month respectively. Conclusions: Most HBV DNA in serum became nega- tive after 9 months of treatment, and the rate of HBeAg seroconversion was 17% (HBV DNA level was lower than 100 pg/ml before treatment). YMDD resistants appeared in 19% patients.
