Single crystal silicon freestanding structures for tensile and fatigue testing were treated with KrF excimer laser to improve surface roughness and accordingly mechanical performance. Sample thickness was 5 μm. Local...Single crystal silicon freestanding structures for tensile and fatigue testing were treated with KrF excimer laser to improve surface roughness and accordingly mechanical performance. Sample thickness was 5 μm. Localized laser treatment was successful in eliminating the scallops developed during Bosch process and in reducing surface roughness. Harsh irradiation at laser energies up to 4 J/cm2 was only possible due to localized treatment without significant vibrations occurring on the freestanding samples that led to fracture in preliminary experiments at energies as low as 0.16 J/cm2. Finite element analysis was used to investigate the temperature distribution on the irradiated structures. Atomic force microscopy (AFM) and Raman spectroscopy were also used to assess surface roughness, crystallinity changes and surface stresses developing on surfaces subjected to perpendicular laser irradiation. At a high energy (3.2 J/cm2) the top surface showed a decrease of roughness compared to fabricated samples. Raman spectroscopy showed the dominance of crystalline silicon after laser irradiation. The effects of laser energy, number of展开更多
This paper presents the estimation of three-dimensional volumetric errors of a machining center by using a tracking interferometer. A tracking interferometer is a laser interferometer with the mechanism to steer the l...This paper presents the estimation of three-dimensional volumetric errors of a machining center by using a tracking interferometer. A tracking interferometer is a laser interferometer with the mechanism to steer the laser direction to follow a target retroreflector. Based on the triangulation principle, the three-dimensional position of the target can be estimated from measured laser displacements. Its capability to measure three-dimensional positioning errors for arbitrary trajectories is important for the indirect measurement of the machine＇s kinematic model. This paper presents experimental investigation of the estimation accuracy of the multilateration-based measurement by a tracking interferometer. A tracking interferometer developed by a part of the authors is used in experiments. In the present experiment, the measured volume of target positions was 100 mm × 100 mm × 100 mm. The estimation accuracy of targets within this volume was not sufficiently high compared to the positioning error of the measured machine tool. The results of the experiment and simulation show that the estimation uncertainty is dependent on tracking interferometer locations relative to target locations. Error sensitivity analysis shows that wider distribution of tracker positions in XY improves the estimation accuracy.展开更多
[ Objective ] To investigate effects of Cordyceps feed additive on growth performance, laying rate and egg quality in laying ducks. [ Method] A total of 270 healthy laying ducks were randomly divided into throe groups...[ Objective ] To investigate effects of Cordyceps feed additive on growth performance, laying rate and egg quality in laying ducks. [ Method] A total of 270 healthy laying ducks were randomly divided into throe groups, 90 ducks in each group. The ducks in the control group, group I and group II were fed common basal diet, basal diet containing 10 g/kg Cordyceps feed additive and basal diet containing 40 g/kg Cordyceps feed additive, respectively. The trial lasted for 28 d. During the whole trial, the ducks were weighed and their growth was observed at an interval of 7 d. The exterior quality and the nutritive indexes of duck eggs were determined. [ Result] After experiments, the body weights of ducks in the group I and group II were increased and higher than that of the control group. In the group I and group II, the laying rate was increased by 1.07% and 2.15%, respectively; the egg weight was increased by 3.95% and 4.16%, respectively; and the feed to egg ratio was decreased by 2.54% and 4.23%, respectively. The egg shape and eggshell thickness were consistent between the control group and experimental groups. In the group I and group II, the protein content of the duck eggs was increased by 5.55% and 17.15%, respectively; the cholesterol content was decreased by 11.79% and 42.14%, respectively; the IgY level was increased by 13.20% and 27.97%, respectively; and the lecithin content was increased by 5.13% and 11.69%, respectively. [Condusion] The Cordyceps feed additive can increase the body weight and laying rate of laying ducks and improve the quality of duck eggs.展开更多
The piezoresistive effect in graphene ribbon has been simulated based on the first-principles electronic-state calculation for the development of novel piezoresistive materials with special performances such as high f...The piezoresistive effect in graphene ribbon has been simulated based on the first-principles electronic-state calculation for the development of novel piezoresistive materials with special performances such as high flexibility and low fabrication cost. We modified theoretical approach for piezoresistivity simulation from our original method for semiconductor systems to improved procedure applicable to conductor systems. The variations of carrier conductivity due to strain along with the graphene ribbon models (armchair model and zigzag model) have been calculated using band carrier densities and their corresponding effective masses derived from the one-dimensional electronic band diagram. We found that the armchair-type graphene nano-ribbon models have low conductivity with heavy effective mass. This is a totally different conductivity from two-dimensional graphene sheet. The variation of band energy diagrams of the zigzag-type graphene nano-ribbon models due to strain is much more sensitive than that of the armchair models. As a result, the longitudinal and transverse gauge factors are high in our calculation, and in particular, the zigzag-type graphene ribbon has an enormous potential material with high piezoresistivity. So, it will be one of the most important candidates that can be used as a high-performance piezoresistive material for fabricating a new high sensitive strain gauge sensor.展开更多
Natural bone constitutes a complex and organized structure of organic and inorganic components with limited ability to regenerate and restore injured tissues,especially in large bone defects.To improve the reconstruct...Natural bone constitutes a complex and organized structure of organic and inorganic components with limited ability to regenerate and restore injured tissues,especially in large bone defects.To improve the reconstruction of the damaged bones,tissue engineering has been introduced as a promising alternative approach to the conventional therapeutic methods including surgical interventions using allograft and autograft implants.Bioengineered composite scaffolds consisting of multifunctional biomaterials in combination with the cells and bioactive therapeutic agents have great promise for bone repair and regeneration.Cellulose and its derivatives are renewable and biodegradable natural polymers that have shown promising potential in bone tissue engineering applications.Cellulose-based scaffolds possess numerous advantages attributed to their excellent properties of non-toxicity,biocompatibility,biodegradability,availability through renewable resources,and the low cost of preparation and processing.Furthermore,cellulose and its derivatives have been extensively used for delivering growth factors and antibiotics directly to the site of the impaired bone tissue to promote tissue repair.This review focuses on the various classifications of cellulose-based composite scaffolds utilized in localized bone drug delivery systems and bone regeneration,including cellulose-organic composites,cellulose-inorganic composites,cellulose-organic/inorganic composites.We will also highlight the physicochemical,mechanical,and biological properties of the different cellulose-based scaffolds for bone tissue engineering applications.展开更多
Emulsion is a disperse system with two immiscible liquids,which demonstrates wide applications in diverse industries.Emulsifcation technology has advanced well with the development of microfluidic process.Compared to ...Emulsion is a disperse system with two immiscible liquids,which demonstrates wide applications in diverse industries.Emulsifcation technology has advanced well with the development of microfluidic process.Compared to conventional methods,the micro-fluidics-based process can produce controllable droplet size and distribution.The droplet formation or breakup is the result of combined effects resulting from interfacial tension,viscous,and inertial forces as well as the forces generated due to hydrodynamic pressure and extermal stimuli.In the current study,typical microfluidic systems,including microchannel array,T-shape,flow-focusing,co-flowing,and membrane systems,are reviewed and the corresponding mechanisms,fow regimes,and main parameters are compared and summarized.展开更多
Repetitive bending fatigue tests were performed using five types of single-crystal silicon specimens with different crystal orientations fabricated from{100}and{110}wafers.Fatigue lifetimes in a wide range between 100...Repetitive bending fatigue tests were performed using five types of single-crystal silicon specimens with different crystal orientations fabricated from{100}and{110}wafers.Fatigue lifetimes in a wide range between 100 and 1010 were obtained using fan-shaped resonator test devices.Fracture surface observation via scanning electron microscope(SEM)revealed that the{111}plane was the primary fracture plane.The crack propagation exponent n was estimated to be 27,which was independent of the crystal orientation and dopant concentration;however,it was dependent on the surface conditions of the etched sidewall.The fatigue strengths relative to the deflection angle were orientation dependent,and the ratios of the factors obtained ranged from 0.86 to 1.25.The strength factors were compared with those obtained from finite element method stress analyses.The calculated stress distributions showed strong orientation dependence,which was well-explained by the elastic anisotropy.The comparison of the strength factors suggested that the first principal stress was a good criterion for fatigue fracture.We include comparisons with specimens tested in our previous report and address the tensile strength,initial crack length,volume effect,and effects of surface roughness such as scallops.展开更多
Light-based additive manufacturing holds great potential in the field of bioprinting due to its exceptional spatial resolution,enabling the reconstruction of intricate tissue structures.However,printing through biolog...Light-based additive manufacturing holds great potential in the field of bioprinting due to its exceptional spatial resolution,enabling the reconstruction of intricate tissue structures.However,printing through biological tissues is severely limited due to the strong optical scattering within the tissues.The propagation of light is scrambled to form random speckle patterns,making it impossible to print features at the diffraction-limited size with conventional printing approaches.The poor tissue penetration depth of ultra-violet or blue light,which is commonly used to trigger photopolymerization,further limits the fabrication of high cell-density tissue constructs.Recently,several strategies based on wavefront shaping have been developed to manipulate the light and refocus it inside scattering media to a diffraction-limited spot.In this study,we present a high-resolution additive manufacturing technique using upconversion nanoparticles and a wavefront shaping method that does not require measurement from an invasive detector,i.e.,it is a non-invasive technique.Upconversion nanoparticles convert near-infrared light to ultraviolet and visible light.The ultraviolet light serves as a light source for photopolymerization and the visible light as a guide star for digital light shaping.The incident light pattern is manipulated using the feedback information of the guide star to focus light through the tissue.In this way,we experimentally demonstrate that near-infrared light can be non-invasively focused through a strongly scattering medium.By exploiting the optical memory effect,we further demonstrate micro-meter resolution additive manufacturing through highly scattering media such as a 300-μm-thick chicken breast.This study provides a concept of high-resolution additive manufacturing through turbid media with potential application in tissue engineering.展开更多
Current trends in artificial intelligence toward larger models demand a rethinking of both hardware and algorithms.Photonics-based systems offer high-speed,energy-efficient computing units,provided algorithms are desi...Current trends in artificial intelligence toward larger models demand a rethinking of both hardware and algorithms.Photonics-based systems offer high-speed,energy-efficient computing units,provided algorithms are designed to exploit photonics'unique strengths.The recent implementation of cellular automata in photonics demonstrates how a few local interactions can achieve high throughput and precision.展开更多
Partial discharge(PD)detection is considered one of the most crucial and effective methods for identifying defects in electrical equipment.Consequently,investigating advanced and efficient PD monitoring techniques is ...Partial discharge(PD)detection is considered one of the most crucial and effective methods for identifying defects in electrical equipment.Consequently,investigating advanced and efficient PD monitoring techniques is essential for the development of gas-insulated equipment(GIE)and the construction of ultra-high-voltage(UHV)networks.This paper first explores the causes and impact characteristics of various defects in GIE based on experimental results and simulation analysis.It then reviews current research on advanced PD measurement techniques,integrating acoustic,chemical and optical methods.The findings preliminarily demonstrate the unique advantages and applicability of the advanced methods for complex detection environments.Finally,this paper ad-dresses the technical challenges and potential breakthroughs associated with these detection techniques.In this regard,this study aims to provide technical insights and research directions for defect detection techniques in UHV GIE.展开更多
The ever-increasing demand for training and inferring with larger machine-learning models requires more efficient hardware solutions due to limitations such as power dissipation and scalability.Optics is a promising c...The ever-increasing demand for training and inferring with larger machine-learning models requires more efficient hardware solutions due to limitations such as power dissipation and scalability.Optics is a promising contender for providing lower power computation,since light propagation through a nonabsorbing medium is a lossless operation.However,to carry out useful and efficient computations with light,generating and controlling nonlinearity optically is a necessity that is still elusive.Multimode fibers(MMFs)have been shown that they can provide nonlinear effects with microwatts of average power while maintaining parallelism and low loss.We propose an optical neural network architecture that performs nonlinear optical computation by controlling the propagation of ultrashort pulses in MMF by wavefront shaping.With a surrogate model,optimal sets of parameters are found to program this optical computer for different tasks with minimal utilization of an electronic computer.We show a remarkable decrease of 97%in the number of model parameters,which leads to an overall 99%digital operation reduction compared to an equivalently performing digital neural network.We further demonstrate that a fully optical implementation can also be performed with competitive accuracies.展开更多
Destruction resistance such as start-up wear resistance characteristics of vitamin E(dl-α-tocopherol)blended ultrahigh molecular weight polyethylene(UHMWPE)were evaluated using the destruction energy index(DEI).The D...Destruction resistance such as start-up wear resistance characteristics of vitamin E(dl-α-tocopherol)blended ultrahigh molecular weight polyethylene(UHMWPE)were evaluated using the destruction energy index(DEI).The DEI is used to evaluate wear-like destruction,by minimising the effects of viscosity at the sliding interface,and is estimated using newly designed friction testers.In this experiment,silicone oils of different viscosities were used to determine micro displacement up to a start-up point,and the DEI of the UHMWPE was changed from 17.48 to 1.84μJ by adding vitamin E.The results suggest that the blending with vitamin E reduces destruction of UHMWPE at start-up friction in silicone oils.展开更多
Artificial intelligence(AI)as a multi-purpose technology is gaining increased attention and is now widely used across all sectors of the economy.The growing complexity of planning and operating power systems makes AI ...Artificial intelligence(AI)as a multi-purpose technology is gaining increased attention and is now widely used across all sectors of the economy.The growing complexity of planning and operating power systems makes AI extremely valuable for the power industry.Until now,there has been a lack of clarity regarding the specific points along the power system supply chain where AI applications demonstrate significant value,as well as which AI domains are best suited for such applications.This study employs an AI taxonomy and automated web search to qualitatively and quantitatively unveil the biggest potentials of AI in the power industry.Our analysis,based on a review of 258’919 publications between 1982 and 2022,reveals where AI applications are particularly promising.We consider six AI domains(reasoning,planning,learning,communication,perception,integration&interaction)and 19 use cases from the power supply chain(i.e.,generation,transmission networks,distribution networks,isolated grids/microgrids,market operations and retail).Our findings indicate that,as of now,the focus is predominantly on AI applications in power retail(55%),transmission(14%)and generation(13%).Most analyzed works describe applications built on algorithms of the AI domains“learning”(45%)and“planning”(14%).Results also suggest that the current definition of AI domains is ambiguous,and they highlight missing information on the actual use and successful implementation of AI in power system use cases.展开更多
The utilisation of Artificial Intelligence (AI) applications in the energy sector is gaining momentum, withincreasingly intensive search for suitable, high-quality and trustworthy solutions that displayed promisingres...The utilisation of Artificial Intelligence (AI) applications in the energy sector is gaining momentum, withincreasingly intensive search for suitable, high-quality and trustworthy solutions that displayed promisingresults in research. The growing interest comes from decision makers of both the industry and policydomains, searching for applications to increase companies’ profitability, raise efficiency and facilitate theenergy transition. This paper aims to provide a novel three-dimensional (3D) indicator for AI applicationsin the energy sector, based on their respective maturity level, regulatory risks and potential benefits. Casestudies are used to exemplify the application of the 3D indicator, showcasing how the developed frameworkcan be used to filter promising AI applications eligible for governmental funding or business development.In addition, the 3D indicator is used to rank AI applications considering different stakeholder preferences(risk-avoidance, profit-seeking, balanced). These results allow AI applications to be better categorised in theface of rapidly emerging national and intergovernmental AI strategies and regulations that constrain the useof AI applications in critical infrastructures.展开更多
Volcano-shaped microelectrodes have demonstrated superior performance in measuring attenuated intracellular action potentials from cardiomyocyte cultures. However, their application to neuronal cultures has not yet yi...Volcano-shaped microelectrodes have demonstrated superior performance in measuring attenuated intracellular action potentials from cardiomyocyte cultures. However, their application to neuronal cultures has not yet yielded reliable intracellular access. This common pitfall supports a growing consensus in the field that nanostructures need to be pitched to the cell of interest to enable intracellular access. Accordingly, we present a new methodology that enables us to resolve the cell/probe interface noninvasively through impedance spectroscopy. This method measures changes in the seal resistance of single cells in a scalable manner to predict the quality of electrophysiological recordings. In particular, the impact of chemical functionalization and variation of the probe’s geometry can be quantitatively measured. We demonstrate this approach on human embryonic kidney cells and primary rodent neurons. Through systematic optimization, the seal resistance can be increased by as much as 20-fold with chemical functionalization, while different probe geometries demonstrated a lower impact. The method presented is therefore well suited to the study of cell coupling to probes designed for electrophysiology, and it is poised to contribute to elucidate the nature and mechanism of plasma membrane disruption by micro/nanostructures.展开更多
A lateral double-diffused metal-oxide-semiconductor field effect transistor （LDMOST） with multiple n-regions in the p-substrate is investigated in detail. Because of the decrescent n-regions, the electric field dist...A lateral double-diffused metal-oxide-semiconductor field effect transistor （LDMOST） with multiple n-regions in the p-substrate is investigated in detail. Because of the decrescent n-regions, the electric field distribu- tion is higher and more uniform, and the breakdown voltage of the new structure is increased by 95%, in comparison with that of a conventional counterpart without substrate n-regions. Based on the trade-off between the breakdown voltage and the on-resistance, the optimal number of n-regions and the other key parameters are achieved. Furthermore, sensitivity research shows that the breakdown voltage is relatively sensitive to the drift region doping and the n-regions＇ lengths.展开更多
In this work,we set out to elucidate the light-harvesting properties of various random and ordered photocatalyst supports(PSs)with different macropore sizes.To accomplish this,we propose two studies of increasing rele...In this work,we set out to elucidate the light-harvesting properties of various random and ordered photocatalyst supports(PSs)with different macropore sizes.To accomplish this,we propose two studies of increasing relevance,enabled by computed tomography(CT)reconstructions and raytracing COMSOL Multiphysics simulations:(a)a 360-degree light release study approximating a PS situated within a compound parabolic concentrator(CPC)or cylindrical LED reactor with open ends;and(b)the same systemas before but with closed ends.The ordered geometry is of interest,as it can be 3D printed at scale with a tailored morphology and porosity,and it can potentially be refined using machine learning models to optimize its light-harvesting properties.As will be shown,the local volumetric light absorption(LVLA)data suggests that an ordered PSwith amore open pore interior and a smaller pore exterior would begin to approach the more isophotonic light-harvesting properties of random PSs.展开更多
文摘Single crystal silicon freestanding structures for tensile and fatigue testing were treated with KrF excimer laser to improve surface roughness and accordingly mechanical performance. Sample thickness was 5 μm. Localized laser treatment was successful in eliminating the scallops developed during Bosch process and in reducing surface roughness. Harsh irradiation at laser energies up to 4 J/cm2 was only possible due to localized treatment without significant vibrations occurring on the freestanding samples that led to fracture in preliminary experiments at energies as low as 0.16 J/cm2. Finite element analysis was used to investigate the temperature distribution on the irradiated structures. Atomic force microscopy (AFM) and Raman spectroscopy were also used to assess surface roughness, crystallinity changes and surface stresses developing on surfaces subjected to perpendicular laser irradiation. At a high energy (3.2 J/cm2) the top surface showed a decrease of roughness compared to fabricated samples. Raman spectroscopy showed the dominance of crystalline silicon after laser irradiation. The effects of laser energy, number of
文摘This paper presents the estimation of three-dimensional volumetric errors of a machining center by using a tracking interferometer. A tracking interferometer is a laser interferometer with the mechanism to steer the laser direction to follow a target retroreflector. Based on the triangulation principle, the three-dimensional position of the target can be estimated from measured laser displacements. Its capability to measure three-dimensional positioning errors for arbitrary trajectories is important for the indirect measurement of the machine＇s kinematic model. This paper presents experimental investigation of the estimation accuracy of the multilateration-based measurement by a tracking interferometer. A tracking interferometer developed by a part of the authors is used in experiments. In the present experiment, the measured volume of target positions was 100 mm × 100 mm × 100 mm. The estimation accuracy of targets within this volume was not sufficiently high compared to the positioning error of the measured machine tool. The results of the experiment and simulation show that the estimation uncertainty is dependent on tracking interferometer locations relative to target locations. Error sensitivity analysis shows that wider distribution of tracker positions in XY improves the estimation accuracy.
基金funded by the Key Science and Technology Project of Anhui Province in 2008 (08010302085)the Agricultural Science and Technology Achievements Transformation Fund Programs of the Ministry of Science and Technology of the People's Republic of China (2008GB2C300131)
文摘[ Objective ] To investigate effects of Cordyceps feed additive on growth performance, laying rate and egg quality in laying ducks. [ Method] A total of 270 healthy laying ducks were randomly divided into throe groups, 90 ducks in each group. The ducks in the control group, group I and group II were fed common basal diet, basal diet containing 10 g/kg Cordyceps feed additive and basal diet containing 40 g/kg Cordyceps feed additive, respectively. The trial lasted for 28 d. During the whole trial, the ducks were weighed and their growth was observed at an interval of 7 d. The exterior quality and the nutritive indexes of duck eggs were determined. [ Result] After experiments, the body weights of ducks in the group I and group II were increased and higher than that of the control group. In the group I and group II, the laying rate was increased by 1.07% and 2.15%, respectively; the egg weight was increased by 3.95% and 4.16%, respectively; and the feed to egg ratio was decreased by 2.54% and 4.23%, respectively. The egg shape and eggshell thickness were consistent between the control group and experimental groups. In the group I and group II, the protein content of the duck eggs was increased by 5.55% and 17.15%, respectively; the cholesterol content was decreased by 11.79% and 42.14%, respectively; the IgY level was increased by 13.20% and 27.97%, respectively; and the lecithin content was increased by 5.13% and 11.69%, respectively. [Condusion] The Cordyceps feed additive can increase the body weight and laying rate of laying ducks and improve the quality of duck eggs.
文摘The piezoresistive effect in graphene ribbon has been simulated based on the first-principles electronic-state calculation for the development of novel piezoresistive materials with special performances such as high flexibility and low fabrication cost. We modified theoretical approach for piezoresistivity simulation from our original method for semiconductor systems to improved procedure applicable to conductor systems. The variations of carrier conductivity due to strain along with the graphene ribbon models (armchair model and zigzag model) have been calculated using band carrier densities and their corresponding effective masses derived from the one-dimensional electronic band diagram. We found that the armchair-type graphene nano-ribbon models have low conductivity with heavy effective mass. This is a totally different conductivity from two-dimensional graphene sheet. The variation of band energy diagrams of the zigzag-type graphene nano-ribbon models due to strain is much more sensitive than that of the armchair models. As a result, the longitudinal and transverse gauge factors are high in our calculation, and in particular, the zigzag-type graphene ribbon has an enormous potential material with high piezoresistivity. So, it will be one of the most important candidates that can be used as a high-performance piezoresistive material for fabricating a new high sensitive strain gauge sensor.
文摘Natural bone constitutes a complex and organized structure of organic and inorganic components with limited ability to regenerate and restore injured tissues,especially in large bone defects.To improve the reconstruction of the damaged bones,tissue engineering has been introduced as a promising alternative approach to the conventional therapeutic methods including surgical interventions using allograft and autograft implants.Bioengineered composite scaffolds consisting of multifunctional biomaterials in combination with the cells and bioactive therapeutic agents have great promise for bone repair and regeneration.Cellulose and its derivatives are renewable and biodegradable natural polymers that have shown promising potential in bone tissue engineering applications.Cellulose-based scaffolds possess numerous advantages attributed to their excellent properties of non-toxicity,biocompatibility,biodegradability,availability through renewable resources,and the low cost of preparation and processing.Furthermore,cellulose and its derivatives have been extensively used for delivering growth factors and antibiotics directly to the site of the impaired bone tissue to promote tissue repair.This review focuses on the various classifications of cellulose-based composite scaffolds utilized in localized bone drug delivery systems and bone regeneration,including cellulose-organic composites,cellulose-inorganic composites,cellulose-organic/inorganic composites.We will also highlight the physicochemical,mechanical,and biological properties of the different cellulose-based scaffolds for bone tissue engineering applications.
基金This work was supported by the National Key Research and Development Program of China(Grant Nos.2017YFB-1103002 and 2018YFB0604304)Federal Ministry for Economic Affairs and Energy,Germany(No.03ET1093C)+1 种基金Fundamental Research Funds for the Central Universities,China(No.2017MS011)the National Natural Science Foundation of China(Grant No.51821004).
文摘Emulsion is a disperse system with two immiscible liquids,which demonstrates wide applications in diverse industries.Emulsifcation technology has advanced well with the development of microfluidic process.Compared to conventional methods,the micro-fluidics-based process can produce controllable droplet size and distribution.The droplet formation or breakup is the result of combined effects resulting from interfacial tension,viscous,and inertial forces as well as the forces generated due to hydrodynamic pressure and extermal stimuli.In the current study,typical microfluidic systems,including microchannel array,T-shape,flow-focusing,co-flowing,and membrane systems,are reviewed and the corresponding mechanisms,fow regimes,and main parameters are compared and summarized.
文摘Repetitive bending fatigue tests were performed using five types of single-crystal silicon specimens with different crystal orientations fabricated from{100}and{110}wafers.Fatigue lifetimes in a wide range between 100 and 1010 were obtained using fan-shaped resonator test devices.Fracture surface observation via scanning electron microscope(SEM)revealed that the{111}plane was the primary fracture plane.The crack propagation exponent n was estimated to be 27,which was independent of the crystal orientation and dopant concentration;however,it was dependent on the surface conditions of the etched sidewall.The fatigue strengths relative to the deflection angle were orientation dependent,and the ratios of the factors obtained ranged from 0.86 to 1.25.The strength factors were compared with those obtained from finite element method stress analyses.The calculated stress distributions showed strong orientation dependence,which was well-explained by the elastic anisotropy.The comparison of the strength factors suggested that the first principal stress was a good criterion for fatigue fracture.We include comparisons with specimens tested in our previous report and address the tensile strength,initial crack length,volume effect,and effects of surface roughness such as scallops.
基金funding from the Swiss National Science Foundation under project number 196971-“Light based Volumetric printing in scattering resins.”。
文摘Light-based additive manufacturing holds great potential in the field of bioprinting due to its exceptional spatial resolution,enabling the reconstruction of intricate tissue structures.However,printing through biological tissues is severely limited due to the strong optical scattering within the tissues.The propagation of light is scrambled to form random speckle patterns,making it impossible to print features at the diffraction-limited size with conventional printing approaches.The poor tissue penetration depth of ultra-violet or blue light,which is commonly used to trigger photopolymerization,further limits the fabrication of high cell-density tissue constructs.Recently,several strategies based on wavefront shaping have been developed to manipulate the light and refocus it inside scattering media to a diffraction-limited spot.In this study,we present a high-resolution additive manufacturing technique using upconversion nanoparticles and a wavefront shaping method that does not require measurement from an invasive detector,i.e.,it is a non-invasive technique.Upconversion nanoparticles convert near-infrared light to ultraviolet and visible light.The ultraviolet light serves as a light source for photopolymerization and the visible light as a guide star for digital light shaping.The incident light pattern is manipulated using the feedback information of the guide star to focus light through the tissue.In this way,we experimentally demonstrate that near-infrared light can be non-invasively focused through a strongly scattering medium.By exploiting the optical memory effect,we further demonstrate micro-meter resolution additive manufacturing through highly scattering media such as a 300-μm-thick chicken breast.This study provides a concept of high-resolution additive manufacturing through turbid media with potential application in tissue engineering.
文摘Current trends in artificial intelligence toward larger models demand a rethinking of both hardware and algorithms.Photonics-based systems offer high-speed,energy-efficient computing units,provided algorithms are designed to exploit photonics'unique strengths.The recent implementation of cellular automata in photonics demonstrates how a few local interactions can achieve high throughput and precision.
基金Natural Science Foundation of Beijing,Grant/Award Number:3244048National Natural Science Foundation of China,Grant/Award Number:52407175‘Chen Guang’project supported by the Shanghai Municipal Education Commission and the Shanghai Education Development Foundation,Grant/Award Number:21CGA63。
文摘Partial discharge(PD)detection is considered one of the most crucial and effective methods for identifying defects in electrical equipment.Consequently,investigating advanced and efficient PD monitoring techniques is essential for the development of gas-insulated equipment(GIE)and the construction of ultra-high-voltage(UHV)networks.This paper first explores the causes and impact characteristics of various defects in GIE based on experimental results and simulation analysis.It then reviews current research on advanced PD measurement techniques,integrating acoustic,chemical and optical methods.The findings preliminarily demonstrate the unique advantages and applicability of the advanced methods for complex detection environments.Finally,this paper ad-dresses the technical challenges and potential breakthroughs associated with these detection techniques.In this regard,this study aims to provide technical insights and research directions for defect detection techniques in UHV GIE.
文摘The ever-increasing demand for training and inferring with larger machine-learning models requires more efficient hardware solutions due to limitations such as power dissipation and scalability.Optics is a promising contender for providing lower power computation,since light propagation through a nonabsorbing medium is a lossless operation.However,to carry out useful and efficient computations with light,generating and controlling nonlinearity optically is a necessity that is still elusive.Multimode fibers(MMFs)have been shown that they can provide nonlinear effects with microwatts of average power while maintaining parallelism and low loss.We propose an optical neural network architecture that performs nonlinear optical computation by controlling the propagation of ultrashort pulses in MMF by wavefront shaping.With a surrogate model,optimal sets of parameters are found to program this optical computer for different tasks with minimal utilization of an electronic computer.We show a remarkable decrease of 97%in the number of model parameters,which leads to an overall 99%digital operation reduction compared to an equivalently performing digital neural network.We further demonstrate that a fully optical implementation can also be performed with competitive accuracies.
文摘Destruction resistance such as start-up wear resistance characteristics of vitamin E(dl-α-tocopherol)blended ultrahigh molecular weight polyethylene(UHMWPE)were evaluated using the destruction energy index(DEI).The DEI is used to evaluate wear-like destruction,by minimising the effects of viscosity at the sliding interface,and is estimated using newly designed friction testers.In this experiment,silicone oils of different viscosities were used to determine micro displacement up to a start-up point,and the DEI of the UHMWPE was changed from 17.48 to 1.84μJ by adding vitamin E.The results suggest that the blending with vitamin E reduces destruction of UHMWPE at start-up friction in silicone oils.
文摘Artificial intelligence(AI)as a multi-purpose technology is gaining increased attention and is now widely used across all sectors of the economy.The growing complexity of planning and operating power systems makes AI extremely valuable for the power industry.Until now,there has been a lack of clarity regarding the specific points along the power system supply chain where AI applications demonstrate significant value,as well as which AI domains are best suited for such applications.This study employs an AI taxonomy and automated web search to qualitatively and quantitatively unveil the biggest potentials of AI in the power industry.Our analysis,based on a review of 258’919 publications between 1982 and 2022,reveals where AI applications are particularly promising.We consider six AI domains(reasoning,planning,learning,communication,perception,integration&interaction)and 19 use cases from the power supply chain(i.e.,generation,transmission networks,distribution networks,isolated grids/microgrids,market operations and retail).Our findings indicate that,as of now,the focus is predominantly on AI applications in power retail(55%),transmission(14%)and generation(13%).Most analyzed works describe applications built on algorithms of the AI domains“learning”(45%)and“planning”(14%).Results also suggest that the current definition of AI domains is ambiguous,and they highlight missing information on the actual use and successful implementation of AI in power system use cases.
文摘The utilisation of Artificial Intelligence (AI) applications in the energy sector is gaining momentum, withincreasingly intensive search for suitable, high-quality and trustworthy solutions that displayed promisingresults in research. The growing interest comes from decision makers of both the industry and policydomains, searching for applications to increase companies’ profitability, raise efficiency and facilitate theenergy transition. This paper aims to provide a novel three-dimensional (3D) indicator for AI applicationsin the energy sector, based on their respective maturity level, regulatory risks and potential benefits. Casestudies are used to exemplify the application of the 3D indicator, showcasing how the developed frameworkcan be used to filter promising AI applications eligible for governmental funding or business development.In addition, the 3D indicator is used to rank AI applications considering different stakeholder preferences(risk-avoidance, profit-seeking, balanced). These results allow AI applications to be better categorised in theface of rapidly emerging national and intergovernmental AI strategies and regulations that constrain the useof AI applications in critical infrastructures.
基金This work was funded by the Swiss National Science Foundation(grant number 200021175943 awarded to P.R.)The authors are indebted to Benoît Desbiolles for his advice in the early stage of this study,Anne-laure Mahul,Somanath Jagannath and Lorène Aeschbach for their advice on neuronal cell culture and early experiments with hippocampal rodent neurons,Rodrigo de Campos Perin for lending his olympic patch clamping skills during a control experiment and the CMi(Center of MicroNanotechnology)staff for their outstanding support and flawless infrastructures.
文摘Volcano-shaped microelectrodes have demonstrated superior performance in measuring attenuated intracellular action potentials from cardiomyocyte cultures. However, their application to neuronal cultures has not yet yielded reliable intracellular access. This common pitfall supports a growing consensus in the field that nanostructures need to be pitched to the cell of interest to enable intracellular access. Accordingly, we present a new methodology that enables us to resolve the cell/probe interface noninvasively through impedance spectroscopy. This method measures changes in the seal resistance of single cells in a scalable manner to predict the quality of electrophysiological recordings. In particular, the impact of chemical functionalization and variation of the probe’s geometry can be quantitatively measured. We demonstrate this approach on human embryonic kidney cells and primary rodent neurons. Through systematic optimization, the seal resistance can be increased by as much as 20-fold with chemical functionalization, while different probe geometries demonstrated a lower impact. The method presented is therefore well suited to the study of cell coupling to probes designed for electrophysiology, and it is poised to contribute to elucidate the nature and mechanism of plasma membrane disruption by micro/nanostructures.
基金supported by the National Natural Science Foundation of China(No.61274080)the Natural Science Foundation of Jiangsu Province(No.BK2011753)the Postdoctoral Science Foundation of China(No.2013M541585)
文摘A lateral double-diffused metal-oxide-semiconductor field effect transistor （LDMOST） with multiple n-regions in the p-substrate is investigated in detail. Because of the decrescent n-regions, the electric field distribu- tion is higher and more uniform, and the breakdown voltage of the new structure is increased by 95%, in comparison with that of a conventional counterpart without substrate n-regions. Based on the trade-off between the breakdown voltage and the on-resistance, the optimal number of n-regions and the other key parameters are achieved. Furthermore, sensitivity research shows that the breakdown voltage is relatively sensitive to the drift region doping and the n-regions＇ lengths.
文摘In this work,we set out to elucidate the light-harvesting properties of various random and ordered photocatalyst supports(PSs)with different macropore sizes.To accomplish this,we propose two studies of increasing relevance,enabled by computed tomography(CT)reconstructions and raytracing COMSOL Multiphysics simulations:(a)a 360-degree light release study approximating a PS situated within a compound parabolic concentrator(CPC)or cylindrical LED reactor with open ends;and(b)the same systemas before but with closed ends.The ordered geometry is of interest,as it can be 3D printed at scale with a tailored morphology and porosity,and it can potentially be refined using machine learning models to optimize its light-harvesting properties.As will be shown,the local volumetric light absorption(LVLA)data suggests that an ordered PSwith amore open pore interior and a smaller pore exterior would begin to approach the more isophotonic light-harvesting properties of random PSs.
