High performance can be obtained for the integrated power electronics module（IPEM） by using a three-dimensional packaging structure instead of a planar structure. A three- dimensional packaged half bridge-IPEM （HB-...High performance can be obtained for the integrated power electronics module（IPEM） by using a three-dimensional packaging structure instead of a planar structure. A three- dimensional packaged half bridge-IPEM （HB-IPEM）, consisting of two chip scale packaged MOSFETs and the corresponding gate driver and protection circuits, is fabricated at the laboratory. The reliability of the IPEM is controlled from the shape design of solder joints and the control of assembly process parameters. The parasitic parameters are extracted using Agilent 4395A impedance analyzer for building the parasitic parameter model of the HB- IPEM. A 12 V/3 A output synchronous rectifier Buck converter using the HB-IPEM is built to test the electrical performance of the HB-IPEM. Low voltage spikes on two MOSFETs illustrate that the three-dimensional package of the HB-IPEM can decrease parasitic inductance. Temperature distribution simulation results of the HB-IPEM using FLOTHERM are given. Heat dissipation of the solder joints makes the peak junction temperature of the chip drop obviously. The package realizes three-dimensional heat dissipation and has better thermal management.展开更多
Physical contamination of food occurs when it comes into contact with foreign objects.Foreign objects can be introduced to food at any time during food delivery and packaging and can cause serious concerns such as bro...Physical contamination of food occurs when it comes into contact with foreign objects.Foreign objects can be introduced to food at any time during food delivery and packaging and can cause serious concerns such as broken teeth or choking.Therefore,a preventive method that can detect and remove foreign objects in advance is required.Several studies have attempted to detect defective products using deep learning networks.Because it is difficult to obtain foreign object-containing food data from industry,most studies on industrial anomaly detection have used unsupervised learning methods.This paper proposes a new method for real-time anomaly detection in packaged food products using a supervised learning network.In this study,a realistic X-ray image training dataset was constructed by augmenting foreign objects with normal product images in a cut-paste manner.Based on the augmented training dataset,we trained YOLOv4,a real-time object detection network,and detected foreign objects in the test data.We evaluated this method on images of pasta,snacks,pistachios,and red beans under the same conditions.The results show that the normal and defective products were classified with an accuracy of at least 94%for all packaged foods.For detecting foreign objects that are typically difficult to detect using the unsupervised learning and traditional methods,the proposed method achieved high-performance realtime anomaly detection.In addition,to eliminate the loss in high-resolution X-ray images,the false positive rate and accuracy could be lowered to 5%with patch-based training and a new post-processing algorithm.展开更多
Two kinds of packaged processes by nickel on the surface of titanium carbide particle are studied in this work. One is the chemical nickel-plating, the other is the organometallic compound decomposition. The compositi...Two kinds of packaged processes by nickel on the surface of titanium carbide particle are studied in this work. One is the chemical nickel-plating, the other is the organometallic compound decomposition. The composition, structure and morphology of the packaged powder were analyzed with XRD, DAT/TGA, SEM, EPMA etc. It has been shown that nickel was even dispersed on the surface of titanium carbide particle by the. two kinds of processes, deposited nickel exists as spherical particles of about 0.1 μm in diameter. The merits and demerits of the two kinds of processes have been compared, the organometallic copmound decomposition among them is a kind of hopeful method, which is not used by other researchers.展开更多
Provision of quality drinking water is paramount for sustaining good public health in urban residents. Packaged water produced and consumed across cities in Nigeria lacks integrity in protecting Health. Water safety p...Provision of quality drinking water is paramount for sustaining good public health in urban residents. Packaged water produced and consumed across cities in Nigeria lacks integrity in protecting Health. Water safety plan based on hazard identification and risk assessment in each component of the water production system is essential in providing quality water by packaged water producing companies in Nigeria. This study aims at developing water safety plan for selected packaged water manufacturing companies in Abeokuta, Ogun State, Nigeria. Hazard identification and risk assessment were carried out based on site inspection studies, key informant interview, questionnaire survey and water sample analysis, and risk analysis using semi-quantitative risk matrix approach. The results revealed a total of 26 possible hazardous events which may compromise water quality such as on-site septic tanks and effluents discharged at source water and improper maintenance and hygiene practices within the system. Based on these, appropriate mitigation and monitoring plans were drawn for action. The research found that water safety plan is feasible for the packaged water systems, and therefore calls on the relevant stakeholders for urgent implementation towards ensuring clean drinking water and protecting public health as more and more people are opting for packaged waters due to uncertain public water safety.展开更多
Recent estimates indicate that more than half the software market belongs to enterprise applications. One of the greatest challenges in these is in conducting the complex process of adaptation of pre-packaged applicat...Recent estimates indicate that more than half the software market belongs to enterprise applications. One of the greatest challenges in these is in conducting the complex process of adaptation of pre-packaged applications, such as Oracle or SAP, to the organization needs. Although very detailed, structured and well documented methods govern this process, the consulting team implementing the method must spend much manual effort in making sure that the guidelines of the method are followed as intended by the method author. The problem is exacerbated by the diversity of skills and roles of team members, and the many sorts of communications of collaboration that methods prescribe. By enhancing the metamodel in which the methods are defined, we automatically produce a CASE tool (so to speak) for the applications of these methods. Our results are successfully employed in a number of large, ongoing projects with demonstrable, non-meager saving.展开更多
The cosmetics industry has entered the era of professional marketing, advanced promotion, refined service, and scientific design of customer order marketing. The previous era of one lipstick or one mascara marketing, ...The cosmetics industry has entered the era of professional marketing, advanced promotion, refined service, and scientific design of customer order marketing. The previous era of one lipstick or one mascara marketing, or one BB cream to be performed as the terminal strategy has gone. Consumers have been through ignorant to rational and to today’s professional consumption era. As brand owners and agents, as well as store operators, it is a must to possess industry knowledge and professionalism to better serve customers. Sometimes customers are more professional than the sellers, under this situation, there will be no way out for the old service style.展开更多
Au80Sn20 alloy is a widely used solder for laser diode packaging.In this paper,the thermal resistance of Ga N-based blue laser diodes packaged in TO56 cans were measured by the forward voltage method.The microstructur...Au80Sn20 alloy is a widely used solder for laser diode packaging.In this paper,the thermal resistance of Ga N-based blue laser diodes packaged in TO56 cans were measured by the forward voltage method.The microstructures of Au80Sn20 solder were then investigated to understand the reason for the difference in thermal resistance.It was found that the microstructure with a higher content of Au-rich phase in the center of the solder and a lower content of(Au,Ni)Sn phase at the interface of the solder/heat sink resulted in lower thermal resistance.This is attributed to the lower thermal resistance of Au-rich phase and higher thermal resistance of(Au,Ni)Sn phase.展开更多
The packing patterns have close correlation with the thermoelastic properties of DNA adsorption films and the relevant detection signals of microcantilevers.In this paper,we investigate the influence of packing patter...The packing patterns have close correlation with the thermoelastic properties of DNA adsorption films and the relevant detection signals of microcantilevers.In this paper,we investigate the influence of packing patterns on the thermoelastic properties of DNA adsorption films,the detection signals of microcantilevers and their temperature dependence.First,the Parsegian's empirical potential based on a mesoscopic liquid crystal theory is employed to describe the interaction energy among coarse-grained DNA cylinders;then,the thought experiment method and the force balance method of nonlinear elastic network nodes are combined to characterize the elastic modulus,prestress and thermal expansion coefficient of DNA adsorption films;finally,based on an effective macroscopic continuum model for DNA microbeam deformation,we study the microcantilever resonance frequency shifts caused by DNA adsorptions and the temperature effect on the microcantilever static deflections,respectively.Results show that,compared with the convex-packaged,the re-entrant honeycomb packing pattern endows DNA adsorption films with a larger adjustable range of the elastic modulus and prestress,so as to make DNA-microcantilevers having an enhanced dynamic detection signal whereas a weaker response to temperature variation.These results are expected to provide a new option for the regulation design of DNA composite materials and microbeam sensors.展开更多
Fifty four, seven month old lambs, that had grazed perennial or annual pasture, were slaughtered and at 24 h post mortem m. longissimus lumborum samples were collected. Half of the fresh muscle section was sliced into...Fifty four, seven month old lambs, that had grazed perennial or annual pasture, were slaughtered and at 24 h post mortem m. longissimus lumborum samples were collected. Half of the fresh muscle section was sliced into three pieces and overwrapped with 15 micron polyvinyl chloride film and displayed under light (Lux = 1500) at 3℃ - 4℃. The remainder of the muscle section was vacuum packaged and aged for 4 weeks at 3℃, before slicing and display. Surface brownness and redness were measured over 3 days of simulated retail display. Aging in vacuum packs led to substantially less brownness and greater redness compared with fresh meat, over the entire three days of display. It was concluded that aging in vacuum packs could be a useful strategy for improving consumer acceptability of retail lamb in local markets, even where there is no logistical or transport need to extend the life of the meat.展开更多
In many industries,there is a growing demand for semiconductor pressure sensors capable of operating in harsh environments with extremely high and low temperatures and high vibrations.Utilizing the piezoresistive effe...In many industries,there is a growing demand for semiconductor pressure sensors capable of operating in harsh environments with extremely high and low temperatures and high vibrations.Utilizing the piezoresistive effect of heavily doped N-type 4H-SiC,we proposed a family design of eight pressure sensor chip structures featuring different diaphragm shapes of circles and squares,along with different piezoresistor configurations.The 4H-SiC piezoresistive pressure sensor was developed using micro-electromechanical systems(MEMS)technology and encapsulated in a leadless package structure via low-stress connection achieved by glass frit sintering.The 4H-SiC pressure sensor demonstrates impressive performance,exhibiting an accuracy of 0.18%FSO and a temperature tolerance range from−50 to 600°C,with a temperature coefficient of zero output as low as 0.08%/°C at 600°C.Furthermore,the developed sensor shows remarkable stability under conditions of high-temperature vibration coupling.The advancement of this family of 4H-SiC pressure sensors provides a promising solution for pressure measurement in harsh industrial environments.展开更多
The exceptional temporal and spatial photon confinement properties of whispering gallery mode (WGM) microcavities render them ideally suitable for nonlinear frequency conversion.Here,we present a reliable packaged mic...The exceptional temporal and spatial photon confinement properties of whispering gallery mode (WGM) microcavities render them ideally suitable for nonlinear frequency conversion.Here,we present a reliable packaged microcavity device with vibration isolation,air tightness,temperature adaptability,and quality factors greater than 2 billion that can serve as a compact and stable platform for soliton optical comb generation.Low-noise soliton combs can be initiated with a repetition rate of 24.98 GHz at wavelengths near 1550 nm with 4 mW threshold power.Our work provides innovative solutions for investigating and manufacturing miniature,economical,and robust microcomb devices.展开更多
Due to the rise of 5G,IoT,AI,and high-performance computing applications,datacenter trafc has grown at a compound annual growth rate of nearly 30%.Furthermore,nearly three-fourths of the datacenter trafc resides withi...Due to the rise of 5G,IoT,AI,and high-performance computing applications,datacenter trafc has grown at a compound annual growth rate of nearly 30%.Furthermore,nearly three-fourths of the datacenter trafc resides within datacenters.The conventional pluggable optics increases at a much slower rate than that of datacenter trafc.The gap between application requirements and the capability of conventional pluggable optics keeps increasing,a trend that is unsustainable.Copackaged optics(CPO)is a disruptive approach to increasing the interconnecting bandwidth density and energy efciency by dramatically shortening the electrical link length through advanced packaging and co-optimization of electronics and photonics.CPO is widely regarded as a promising solution for future datacenter interconnections,and silicon platform is the most promising platform for large-scale integration.Leading international companies(e.g.,Intel,Broadcom and IBM)have heavily investigated in CPO technology,an inter-disciplinary research feld that involves photonic devices,integrated circuits design,packaging,photonic device modeling,electronic-photonic co-simulation,applications,and standardization.This review aims to provide the readers a comprehensive overview of the state-of-the-art progress of CPO in silicon platform,identify the key challenges,and point out the potential solutions,hoping to encourage collaboration between diferent research felds to accelerate the development of CPO technology.展开更多
Operating Lithium-ion batteries at their temperature limits is a challenging design task due to explosion risk at high temperatures and rapid degradation at low temperatures.Depending on the battery package design,tho...Operating Lithium-ion batteries at their temperature limits is a challenging design task due to explosion risk at high temperatures and rapid degradation at low temperatures.Depending on the battery package design,those risks can be solved with passive solutions,which require no active cooling or heating.Thecurrentwork aims to optimize the pack design and materials of the type-NCR18650B battery based on a wide range of operation temperature.The lower limit was denoted by cold case while the maximum limit was expressed by hot case.A combined analyticalnumerical approach was developed to model the heat generation inside the battery.A thermal resistance analysis was used to determine the boundary conditions of the numerical model.The governing differential equations for the 1-D heat generation model were solved analytically.The numerical analysis was considered to determine the best battery pack design based on material parameters,number of batteries,and geometrical arrangement.The analytical results revealedthat the cold case canbe selectedas theworst case and thebestmodel wasobtainedusing thehexagonal-shaped 10-battery pack that was covered with Delrin of 1.8 mm in thickness.The numerical results showed that the best model was the hexagonal-shaped 10-battery pack with Delrin of 2 mm in thickness that achieved the largest temperature of−20.6℃ in the cold case.展开更多
The photothermal effect enhances the antibacterial activity by generating localized heat that disrupts microbial cells,leading to increased bacterial inactivation.The objective of this study was to develop and evaluat...The photothermal effect enhances the antibacterial activity by generating localized heat that disrupts microbial cells,leading to increased bacterial inactivation.The objective of this study was to develop and evaluate the antibacterial and photothermal applications of polydopamine-berberine nanoparticles(PDA-BBR-NPs),incorporating them into a sodium alginate matrix for food preservation.The self-assembled PDA-BBR-NPs were synthesized using a solution oxidation method and characterized by scanning electron microscopy,Fourier transform infrared spectroscopy,and nanoparticle size analysis.The results demonstrated that PDA-BBR-NPs were uniform spheres with an average diameter of 177.1 nm.Drug loading and encapsulation efficiency tests showed that the optimal formulation had a drug loading capacity of 48.4%and an encapsulation efficiency of 84.70%.Antibacterial activity against Escherichia coli and Staphylococcus aureus was evaluated using the dilution coating plate method,showing an inhibition rate of over 98%.Photothermal testing under 808 nm near-infrared irradiation revealed a maximum photothermal conversion efficiency of 32.65%.To assess the practical application of the nanoparticles,they were incorporated into a sodium alginate-based coating for the preservation of Kyoho grapes.Key parameters such as weight loss rate,pH,titratable acidity,and soluble solids content were monitored over a 12-day storage period at room temperature.The PDA-BBR-near-infrared spectroscopy-treated group exhibited significantly reduced weight loss rate(6.08%lower than the control group)and a slower decrease in pH.The coating effectively inhibited microbial activity and extended the shelf life of the grapes by 3-6 days compared to the control group.These findings demonstrated the potential of PDA-BBR-NPs to enhance the preservation of fresh produce through their combined antibacterial and photothermal effects,offering a promising method for extending fruit shelf life.展开更多
This review draws attention to the innovative use of arrowroot(Maranta arundinacea)fiber as a unique and underutilized biomass source for nanocrystalline cellulose(NCC)-based nanocomposites,presenting a noteworthy alt...This review draws attention to the innovative use of arrowroot(Maranta arundinacea)fiber as a unique and underutilized biomass source for nanocrystalline cellulose(NCC)-based nanocomposites,presenting a noteworthy alternative to extensively researched materials like wood pulp,bacterial cellulose,and chemically modified NCCs.In contrast to traditional sources,arrowroot possesses a naturally elevated cellulose and diminished lignin content,facilitating more effective NCC extraction requiring reduced chemical input and enabling environmentally friendly processing techniques.The review evaluates the performance of arrowroot-derived nanocomposites against systems documented in the literature,including NCC-based shape memory composites and nanoparticle-reinforced films,demonstrating enhanced tensile strength,improved moisture barrier properties,and thermal stability,as well as potential piezoelectric response.This study recognizes arrowroot as a viable option in the biomass-based nanocellulose sector,providing ecological and functional benefits while tackling significant issues such as process scalability and feedstock variability,thereby offering important insights for the advancement of sustainable materials.展开更多
To investigate the long-term performance of the packaged fiber Bragg grating(FBG)sensors embedded in civil infrastructure for strain monitoring,in this paper,the influence of host matrix’s creep effect on the behavio...To investigate the long-term performance of the packaged fiber Bragg grating(FBG)sensors embedded in civil infrastructure for strain monitoring,in this paper,the influence of host matrix’s creep effect on the behavior of the FBG sensors was systematically studied through theoretical,numerical,and experimental analysis.A theoretical strain transfer analysis between the optic fiber,packaging layer,and host matrix to consider the creep effect of the host matrix was performed accordingly for long-term strain monitoring.Parametric studies were carried out using numerical analysis for FBG sensors packaged with glass fiber reinforced plastic(GFRP),also known as FBG-GFRP sensors in concrete,as an example.The results show that embedded in a creep medium,an acceptable long-term performance of packaged FBG sensors requires the packaging layer to have a minimum length and maximum thickness.Laboratory long-term creep tests using epoxy resin and concrete as host matrix for FBG-GFRP sensors also clearly demonstrated that the influence of creep effect cannot be ignored for strain measurements if the host matrix has a creep potential and the developed correction model performed well to reduce measurement errors of such sensors in creep medium.展开更多
This paper presents a micro packaged MEMS pressure sensor for intracranial pressure measurement which belongs to BioMEMS. It can be used in lumbar puncture surgery to measure intracranial pressure. Minia- turization i...This paper presents a micro packaged MEMS pressure sensor for intracranial pressure measurement which belongs to BioMEMS. It can be used in lumbar puncture surgery to measure intracranial pressure. Minia- turization is key for lumbar puncture surgery because the sensor must be small enough to allow it be placed in the reagent chamber of the lumbar puncture needle. The size of the sensor is decided by the size of the sensor chip and package. Our sensor chip is based on silicon piezoresistive effect and the size is 400 × 400 μm2. It is much smaller than the reported polymer intracranial pressure sensors such as liquid crystal polymer sensors. In terms of package, the traditional dual in-line package obviously could not match the size need, the minimal size of recently reported MEMS-based intracranial pressure sensors after packaging is 10 × 10 mm2. In this work, we are the first to introduce a quad flat no-lead package as the package form of piezoresistive intracranial pressure sensors, the whole size of the sensor is minimized to only 3 × 3 mm2. Considering the liquid measurement environment, the sensor is gummed and waterproof performance is tested; the sensitivity of the sensor is 0.9 × 10-2 mV/kPa.展开更多
Objectives:To deveop on-pack visual indicators for the real-time monitoring of raw beef steaks in a modified atmospheric packaging(MAP).Materials and Methods:Three indicators were prepared by spray deposition of a nan...Objectives:To deveop on-pack visual indicators for the real-time monitoring of raw beef steaks in a modified atmospheric packaging(MAP).Materials and Methods:Three indicators were prepared by spray deposition of a nanocellulose suspension(1.5%,in mass)with the desired concentration of the pH-sensitive indicators,either red cabbage(RC)extract,black carrot(BC)extract,or chlorophenol red(CPR).The responsiveness of the colorimetric pH indicators,assessed visually and by CiE-Lab quantitative analysis,to the freshness of raw beef steaks stored under MAP conditions at 4℃ or 20℃,was analysed over7d.Results:All the indicators showed a colour change for beef steak stored at 4℃ for 7 d that was noticeable with the naked eye and had a △E value>12.The sensitivity of the RC pH indicator was superior to that of the BC and CPR pH indicators.A study linking total microbial count(aerobic+Escherichia coli+coliform)and the quantitative colorimetric response of the indicators(△E)revealed a strong linear correlation.Conclusions:The developed colorimetric pH indicators could be used to monitor the freshness of raw beef and as an alternative to the bestbefore date commonly used in pre-packagedmeat.展开更多
Sn-based solder is a widely used interconnection material in the field of electronic packaging;however,the performance requirements for these solders are becoming increasingly demanding owing to the rapid development ...Sn-based solder is a widely used interconnection material in the field of electronic packaging;however,the performance requirements for these solders are becoming increasingly demanding owing to the rapid development in this area.In recent years,the addition of micro/nanoreinforcement phases to Sn-based solders has provided a solution to improve the intrinsic properties of the solders.This paper reviews the progress in Sn-based micro/nanoreinforced composite solders over the past decade.The types of reinforcement particles,preparation methods of the composite solders,and strengthening effects on the microstructure,wettability,melting point,mechanical properties,and corrosion resistance under different particle-addition levels are discussed and summarized.The mechanisms of performance enhancement are summarized based on material-strengthening effects such as grain refinement and second-phase dispersion strengthening.In addition,we discuss the current shortcomings of such composite solders and possible future improvements,thereby establishing a theoretical foundation for the future development of Sn-based solders.展开更多
Three types of Al/Al−27%Si laminated composites,each containing 22%Si,were fabricated via hot pressing and hot rolling.The microstructures,mechanical properties and thermo-physical properties of these composites were ...Three types of Al/Al−27%Si laminated composites,each containing 22%Si,were fabricated via hot pressing and hot rolling.The microstructures,mechanical properties and thermo-physical properties of these composites were investigated.The results demonstrated that the three laminated composites exhibited similar microstructural features,characterized by well-bonded interfaces between the Al layer and the Al−27%Si alloy layer.The tensile and flexural strengths of the composites were significantly higher than those of both Al−22%Si and Al−27%Si alloys.These strengths increased gradually with decreasing the layer thickness,reaching peak values of 222.5 and 407.4 MPa,respectively.Crack deflection was observed in the cross-sections of the bending fracture surfaces,which contributed to the enhanced strength and toughness.In terms of thermo-physical properties,the thermal conductivity of the composites was lower than that of Al−22%Si and Al−27%Si alloys.The minimum reductions in thermal conductivity were 6.8%and 0.9%for the T3 laminated composite,respectively.Additionally,the coefficient of thermal expansion of the composites was improved,exhibiting varying temperature-dependent behaviors.展开更多
基金Fok Ying Tung Education Foundation(No.91058)the Natural Science Foundation of High Education Institutions of Jiangsu Province(No.08KJD470004)Qing Lan Project of Jiangsu Province of 2008
文摘High performance can be obtained for the integrated power electronics module（IPEM） by using a three-dimensional packaging structure instead of a planar structure. A three- dimensional packaged half bridge-IPEM （HB-IPEM）, consisting of two chip scale packaged MOSFETs and the corresponding gate driver and protection circuits, is fabricated at the laboratory. The reliability of the IPEM is controlled from the shape design of solder joints and the control of assembly process parameters. The parasitic parameters are extracted using Agilent 4395A impedance analyzer for building the parasitic parameter model of the HB- IPEM. A 12 V/3 A output synchronous rectifier Buck converter using the HB-IPEM is built to test the electrical performance of the HB-IPEM. Low voltage spikes on two MOSFETs illustrate that the three-dimensional package of the HB-IPEM can decrease parasitic inductance. Temperature distribution simulation results of the HB-IPEM using FLOTHERM are given. Heat dissipation of the solder joints makes the peak junction temperature of the chip drop obviously. The package realizes three-dimensional heat dissipation and has better thermal management.
基金supported by Basic Science Research Program through the National Research Foundation(NRF)of Korea funded by the Ministry of Education(grant number 2020R1A6A1A03040583,Kangjik Kim,www.nrf.re.kr)this research was also supported by the Soonchunhyang University Research Fund.
文摘Physical contamination of food occurs when it comes into contact with foreign objects.Foreign objects can be introduced to food at any time during food delivery and packaging and can cause serious concerns such as broken teeth or choking.Therefore,a preventive method that can detect and remove foreign objects in advance is required.Several studies have attempted to detect defective products using deep learning networks.Because it is difficult to obtain foreign object-containing food data from industry,most studies on industrial anomaly detection have used unsupervised learning methods.This paper proposes a new method for real-time anomaly detection in packaged food products using a supervised learning network.In this study,a realistic X-ray image training dataset was constructed by augmenting foreign objects with normal product images in a cut-paste manner.Based on the augmented training dataset,we trained YOLOv4,a real-time object detection network,and detected foreign objects in the test data.We evaluated this method on images of pasta,snacks,pistachios,and red beans under the same conditions.The results show that the normal and defective products were classified with an accuracy of at least 94%for all packaged foods.For detecting foreign objects that are typically difficult to detect using the unsupervised learning and traditional methods,the proposed method achieved high-performance realtime anomaly detection.In addition,to eliminate the loss in high-resolution X-ray images,the false positive rate and accuracy could be lowered to 5%with patch-based training and a new post-processing algorithm.
文摘Two kinds of packaged processes by nickel on the surface of titanium carbide particle are studied in this work. One is the chemical nickel-plating, the other is the organometallic compound decomposition. The composition, structure and morphology of the packaged powder were analyzed with XRD, DAT/TGA, SEM, EPMA etc. It has been shown that nickel was even dispersed on the surface of titanium carbide particle by the. two kinds of processes, deposited nickel exists as spherical particles of about 0.1 μm in diameter. The merits and demerits of the two kinds of processes have been compared, the organometallic copmound decomposition among them is a kind of hopeful method, which is not used by other researchers.
文摘Provision of quality drinking water is paramount for sustaining good public health in urban residents. Packaged water produced and consumed across cities in Nigeria lacks integrity in protecting Health. Water safety plan based on hazard identification and risk assessment in each component of the water production system is essential in providing quality water by packaged water producing companies in Nigeria. This study aims at developing water safety plan for selected packaged water manufacturing companies in Abeokuta, Ogun State, Nigeria. Hazard identification and risk assessment were carried out based on site inspection studies, key informant interview, questionnaire survey and water sample analysis, and risk analysis using semi-quantitative risk matrix approach. The results revealed a total of 26 possible hazardous events which may compromise water quality such as on-site septic tanks and effluents discharged at source water and improper maintenance and hygiene practices within the system. Based on these, appropriate mitigation and monitoring plans were drawn for action. The research found that water safety plan is feasible for the packaged water systems, and therefore calls on the relevant stakeholders for urgent implementation towards ensuring clean drinking water and protecting public health as more and more people are opting for packaged waters due to uncertain public water safety.
文摘Recent estimates indicate that more than half the software market belongs to enterprise applications. One of the greatest challenges in these is in conducting the complex process of adaptation of pre-packaged applications, such as Oracle or SAP, to the organization needs. Although very detailed, structured and well documented methods govern this process, the consulting team implementing the method must spend much manual effort in making sure that the guidelines of the method are followed as intended by the method author. The problem is exacerbated by the diversity of skills and roles of team members, and the many sorts of communications of collaboration that methods prescribe. By enhancing the metamodel in which the methods are defined, we automatically produce a CASE tool (so to speak) for the applications of these methods. Our results are successfully employed in a number of large, ongoing projects with demonstrable, non-meager saving.
文摘The cosmetics industry has entered the era of professional marketing, advanced promotion, refined service, and scientific design of customer order marketing. The previous era of one lipstick or one mascara marketing, or one BB cream to be performed as the terminal strategy has gone. Consumers have been through ignorant to rational and to today’s professional consumption era. As brand owners and agents, as well as store operators, it is a must to possess industry knowledge and professionalism to better serve customers. Sometimes customers are more professional than the sellers, under this situation, there will be no way out for the old service style.
基金supported by the National Key Research and Development Program of China(Grant Nos.2016YFB0401803,2017YFE0131500,2017YFB0405000)National Natural Science Foundation of China(Grant Nos.61834008,61574160,61804164,and 61704184)+1 种基金Natural Science Foundation of Jiangsu province(BK20180254)China Postdoctoral Science Foundation(2018M630619)。
文摘Au80Sn20 alloy is a widely used solder for laser diode packaging.In this paper,the thermal resistance of Ga N-based blue laser diodes packaged in TO56 cans were measured by the forward voltage method.The microstructures of Au80Sn20 solder were then investigated to understand the reason for the difference in thermal resistance.It was found that the microstructure with a higher content of Au-rich phase in the center of the solder and a lower content of(Au,Ni)Sn phase at the interface of the solder/heat sink resulted in lower thermal resistance.This is attributed to the lower thermal resistance of Au-rich phase and higher thermal resistance of(Au,Ni)Sn phase.
基金The research was supported by the National Natural Science Foundation of China(Grants 11772182,11272193 and 10872121)the Program of Shanghai Municipal Education Commission(Grant 2019-01-07-00-09-E00018).
文摘The packing patterns have close correlation with the thermoelastic properties of DNA adsorption films and the relevant detection signals of microcantilevers.In this paper,we investigate the influence of packing patterns on the thermoelastic properties of DNA adsorption films,the detection signals of microcantilevers and their temperature dependence.First,the Parsegian's empirical potential based on a mesoscopic liquid crystal theory is employed to describe the interaction energy among coarse-grained DNA cylinders;then,the thought experiment method and the force balance method of nonlinear elastic network nodes are combined to characterize the elastic modulus,prestress and thermal expansion coefficient of DNA adsorption films;finally,based on an effective macroscopic continuum model for DNA microbeam deformation,we study the microcantilever resonance frequency shifts caused by DNA adsorptions and the temperature effect on the microcantilever static deflections,respectively.Results show that,compared with the convex-packaged,the re-entrant honeycomb packing pattern endows DNA adsorption films with a larger adjustable range of the elastic modulus and prestress,so as to make DNA-microcantilevers having an enhanced dynamic detection signal whereas a weaker response to temperature variation.These results are expected to provide a new option for the regulation design of DNA composite materials and microbeam sensors.
文摘Fifty four, seven month old lambs, that had grazed perennial or annual pasture, were slaughtered and at 24 h post mortem m. longissimus lumborum samples were collected. Half of the fresh muscle section was sliced into three pieces and overwrapped with 15 micron polyvinyl chloride film and displayed under light (Lux = 1500) at 3℃ - 4℃. The remainder of the muscle section was vacuum packaged and aged for 4 weeks at 3℃, before slicing and display. Surface brownness and redness were measured over 3 days of simulated retail display. Aging in vacuum packs led to substantially less brownness and greater redness compared with fresh meat, over the entire three days of display. It was concluded that aging in vacuum packs could be a useful strategy for improving consumer acceptability of retail lamb in local markets, even where there is no logistical or transport need to extend the life of the meat.
基金supported by the National Natural Science Foundation of China(62401451,62131017)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZB20230584)the China Postdoctoral Science Foundation(2024M762579)。
文摘In many industries,there is a growing demand for semiconductor pressure sensors capable of operating in harsh environments with extremely high and low temperatures and high vibrations.Utilizing the piezoresistive effect of heavily doped N-type 4H-SiC,we proposed a family design of eight pressure sensor chip structures featuring different diaphragm shapes of circles and squares,along with different piezoresistor configurations.The 4H-SiC piezoresistive pressure sensor was developed using micro-electromechanical systems(MEMS)technology and encapsulated in a leadless package structure via low-stress connection achieved by glass frit sintering.The 4H-SiC pressure sensor demonstrates impressive performance,exhibiting an accuracy of 0.18%FSO and a temperature tolerance range from−50 to 600°C,with a temperature coefficient of zero output as low as 0.08%/°C at 600°C.Furthermore,the developed sensor shows remarkable stability under conditions of high-temperature vibration coupling.The advancement of this family of 4H-SiC pressure sensors provides a promising solution for pressure measurement in harsh industrial environments.
基金supported by the National Natural Science Foundation of China (No. 62305006)the Natural Science FoundationofJiangsuProvince(Nos.BK20230287 and BK20230286)the Nantong Social Livelihood Science and Technology Planning Project (Nos. MS12022003 and MS2023071)。
文摘The exceptional temporal and spatial photon confinement properties of whispering gallery mode (WGM) microcavities render them ideally suitable for nonlinear frequency conversion.Here,we present a reliable packaged microcavity device with vibration isolation,air tightness,temperature adaptability,and quality factors greater than 2 billion that can serve as a compact and stable platform for soliton optical comb generation.Low-noise soliton combs can be initiated with a repetition rate of 24.98 GHz at wavelengths near 1550 nm with 4 mW threshold power.Our work provides innovative solutions for investigating and manufacturing miniature,economical,and robust microcomb devices.
基金supported by the National Key Research and Development Program of China(No.2019YFB2203004).
文摘Due to the rise of 5G,IoT,AI,and high-performance computing applications,datacenter trafc has grown at a compound annual growth rate of nearly 30%.Furthermore,nearly three-fourths of the datacenter trafc resides within datacenters.The conventional pluggable optics increases at a much slower rate than that of datacenter trafc.The gap between application requirements and the capability of conventional pluggable optics keeps increasing,a trend that is unsustainable.Copackaged optics(CPO)is a disruptive approach to increasing the interconnecting bandwidth density and energy efciency by dramatically shortening the electrical link length through advanced packaging and co-optimization of electronics and photonics.CPO is widely regarded as a promising solution for future datacenter interconnections,and silicon platform is the most promising platform for large-scale integration.Leading international companies(e.g.,Intel,Broadcom and IBM)have heavily investigated in CPO technology,an inter-disciplinary research feld that involves photonic devices,integrated circuits design,packaging,photonic device modeling,electronic-photonic co-simulation,applications,and standardization.This review aims to provide the readers a comprehensive overview of the state-of-the-art progress of CPO in silicon platform,identify the key challenges,and point out the potential solutions,hoping to encourage collaboration between diferent research felds to accelerate the development of CPO technology.
文摘Operating Lithium-ion batteries at their temperature limits is a challenging design task due to explosion risk at high temperatures and rapid degradation at low temperatures.Depending on the battery package design,those risks can be solved with passive solutions,which require no active cooling or heating.Thecurrentwork aims to optimize the pack design and materials of the type-NCR18650B battery based on a wide range of operation temperature.The lower limit was denoted by cold case while the maximum limit was expressed by hot case.A combined analyticalnumerical approach was developed to model the heat generation inside the battery.A thermal resistance analysis was used to determine the boundary conditions of the numerical model.The governing differential equations for the 1-D heat generation model were solved analytically.The numerical analysis was considered to determine the best battery pack design based on material parameters,number of batteries,and geometrical arrangement.The analytical results revealedthat the cold case canbe selectedas theworst case and thebestmodel wasobtainedusing thehexagonal-shaped 10-battery pack that was covered with Delrin of 1.8 mm in thickness.The numerical results showed that the best model was the hexagonal-shaped 10-battery pack with Delrin of 2 mm in thickness that achieved the largest temperature of−20.6℃ in the cold case.
基金supported by Research Projects of Liaoning Provincial Department of Education(LJ212410163008)the National Training Program of Innovation and Entrepreneurship for Undergraduates of Shenyang Pharmaceutical University(202410163042)。
文摘The photothermal effect enhances the antibacterial activity by generating localized heat that disrupts microbial cells,leading to increased bacterial inactivation.The objective of this study was to develop and evaluate the antibacterial and photothermal applications of polydopamine-berberine nanoparticles(PDA-BBR-NPs),incorporating them into a sodium alginate matrix for food preservation.The self-assembled PDA-BBR-NPs were synthesized using a solution oxidation method and characterized by scanning electron microscopy,Fourier transform infrared spectroscopy,and nanoparticle size analysis.The results demonstrated that PDA-BBR-NPs were uniform spheres with an average diameter of 177.1 nm.Drug loading and encapsulation efficiency tests showed that the optimal formulation had a drug loading capacity of 48.4%and an encapsulation efficiency of 84.70%.Antibacterial activity against Escherichia coli and Staphylococcus aureus was evaluated using the dilution coating plate method,showing an inhibition rate of over 98%.Photothermal testing under 808 nm near-infrared irradiation revealed a maximum photothermal conversion efficiency of 32.65%.To assess the practical application of the nanoparticles,they were incorporated into a sodium alginate-based coating for the preservation of Kyoho grapes.Key parameters such as weight loss rate,pH,titratable acidity,and soluble solids content were monitored over a 12-day storage period at room temperature.The PDA-BBR-near-infrared spectroscopy-treated group exhibited significantly reduced weight loss rate(6.08%lower than the control group)and a slower decrease in pH.The coating effectively inhibited microbial activity and extended the shelf life of the grapes by 3-6 days compared to the control group.These findings demonstrated the potential of PDA-BBR-NPs to enhance the preservation of fresh produce through their combined antibacterial and photothermal effects,offering a promising method for extending fruit shelf life.
基金the financial support provided by Universiti Putra Malaysiasupported by the Matching Grant(9300489).
文摘This review draws attention to the innovative use of arrowroot(Maranta arundinacea)fiber as a unique and underutilized biomass source for nanocrystalline cellulose(NCC)-based nanocomposites,presenting a noteworthy alternative to extensively researched materials like wood pulp,bacterial cellulose,and chemically modified NCCs.In contrast to traditional sources,arrowroot possesses a naturally elevated cellulose and diminished lignin content,facilitating more effective NCC extraction requiring reduced chemical input and enabling environmentally friendly processing techniques.The review evaluates the performance of arrowroot-derived nanocomposites against systems documented in the literature,including NCC-based shape memory composites and nanoparticle-reinforced films,demonstrating enhanced tensile strength,improved moisture barrier properties,and thermal stability,as well as potential piezoelectric response.This study recognizes arrowroot as a viable option in the biomass-based nanocellulose sector,providing ecological and functional benefits while tackling significant issues such as process scalability and feedstock variability,thereby offering important insights for the advancement of sustainable materials.
基金supported by the The National Key R&D Program of China[2018FYC0705606]。
文摘To investigate the long-term performance of the packaged fiber Bragg grating(FBG)sensors embedded in civil infrastructure for strain monitoring,in this paper,the influence of host matrix’s creep effect on the behavior of the FBG sensors was systematically studied through theoretical,numerical,and experimental analysis.A theoretical strain transfer analysis between the optic fiber,packaging layer,and host matrix to consider the creep effect of the host matrix was performed accordingly for long-term strain monitoring.Parametric studies were carried out using numerical analysis for FBG sensors packaged with glass fiber reinforced plastic(GFRP),also known as FBG-GFRP sensors in concrete,as an example.The results show that embedded in a creep medium,an acceptable long-term performance of packaged FBG sensors requires the packaging layer to have a minimum length and maximum thickness.Laboratory long-term creep tests using epoxy resin and concrete as host matrix for FBG-GFRP sensors also clearly demonstrated that the influence of creep effect cannot be ignored for strain measurements if the host matrix has a creep potential and the developed correction model performed well to reduce measurement errors of such sensors in creep medium.
基金Project supported by the National Natural Science Foundation of China(Nos.61025021,61434001)the ‘Thousands Talents’ Program for Pioneer Researchers and Its Innovation Team,China
文摘This paper presents a micro packaged MEMS pressure sensor for intracranial pressure measurement which belongs to BioMEMS. It can be used in lumbar puncture surgery to measure intracranial pressure. Minia- turization is key for lumbar puncture surgery because the sensor must be small enough to allow it be placed in the reagent chamber of the lumbar puncture needle. The size of the sensor is decided by the size of the sensor chip and package. Our sensor chip is based on silicon piezoresistive effect and the size is 400 × 400 μm2. It is much smaller than the reported polymer intracranial pressure sensors such as liquid crystal polymer sensors. In terms of package, the traditional dual in-line package obviously could not match the size need, the minimal size of recently reported MEMS-based intracranial pressure sensors after packaging is 10 × 10 mm2. In this work, we are the first to introduce a quad flat no-lead package as the package form of piezoresistive intracranial pressure sensors, the whole size of the sensor is minimized to only 3 × 3 mm2. Considering the liquid measurement environment, the sensor is gummed and waterproof performance is tested; the sensitivity of the sensor is 0.9 × 10-2 mV/kPa.
基金co-funded by Meat Livestock Australia(MLA)under the Monash Graduate Research Industry Partnership(GRIP)Program(project P.PSH.0889).
文摘Objectives:To deveop on-pack visual indicators for the real-time monitoring of raw beef steaks in a modified atmospheric packaging(MAP).Materials and Methods:Three indicators were prepared by spray deposition of a nanocellulose suspension(1.5%,in mass)with the desired concentration of the pH-sensitive indicators,either red cabbage(RC)extract,black carrot(BC)extract,or chlorophenol red(CPR).The responsiveness of the colorimetric pH indicators,assessed visually and by CiE-Lab quantitative analysis,to the freshness of raw beef steaks stored under MAP conditions at 4℃ or 20℃,was analysed over7d.Results:All the indicators showed a colour change for beef steak stored at 4℃ for 7 d that was noticeable with the naked eye and had a △E value>12.The sensitivity of the RC pH indicator was superior to that of the BC and CPR pH indicators.A study linking total microbial count(aerobic+Escherichia coli+coliform)and the quantitative colorimetric response of the indicators(△E)revealed a strong linear correlation.Conclusions:The developed colorimetric pH indicators could be used to monitor the freshness of raw beef and as an alternative to the bestbefore date commonly used in pre-packagedmeat.
基金financially supported by the State Key Laboratory for Mechanical Behavior of Materials,China(No.202325012)the National Natural Science Foundation of China(No.U21A20128).
文摘Sn-based solder is a widely used interconnection material in the field of electronic packaging;however,the performance requirements for these solders are becoming increasingly demanding owing to the rapid development in this area.In recent years,the addition of micro/nanoreinforcement phases to Sn-based solders has provided a solution to improve the intrinsic properties of the solders.This paper reviews the progress in Sn-based micro/nanoreinforced composite solders over the past decade.The types of reinforcement particles,preparation methods of the composite solders,and strengthening effects on the microstructure,wettability,melting point,mechanical properties,and corrosion resistance under different particle-addition levels are discussed and summarized.The mechanisms of performance enhancement are summarized based on material-strengthening effects such as grain refinement and second-phase dispersion strengthening.In addition,we discuss the current shortcomings of such composite solders and possible future improvements,thereby establishing a theoretical foundation for the future development of Sn-based solders.
基金supported by the National Natural Science Foundation of China(No.52274369)the National Key Laboratory of Science and Technology on High-strength Structural Materials,China(No.623020034).
文摘Three types of Al/Al−27%Si laminated composites,each containing 22%Si,were fabricated via hot pressing and hot rolling.The microstructures,mechanical properties and thermo-physical properties of these composites were investigated.The results demonstrated that the three laminated composites exhibited similar microstructural features,characterized by well-bonded interfaces between the Al layer and the Al−27%Si alloy layer.The tensile and flexural strengths of the composites were significantly higher than those of both Al−22%Si and Al−27%Si alloys.These strengths increased gradually with decreasing the layer thickness,reaching peak values of 222.5 and 407.4 MPa,respectively.Crack deflection was observed in the cross-sections of the bending fracture surfaces,which contributed to the enhanced strength and toughness.In terms of thermo-physical properties,the thermal conductivity of the composites was lower than that of Al−22%Si and Al−27%Si alloys.The minimum reductions in thermal conductivity were 6.8%and 0.9%for the T3 laminated composite,respectively.Additionally,the coefficient of thermal expansion of the composites was improved,exhibiting varying temperature-dependent behaviors.
