The objective of this study is to improve the mechanical properties and machining performance of high thermal conductivity and low expansion silicon carbide dispersion-strengthened hypereutectic aluminum-silicon elect...The objective of this study is to improve the mechanical properties and machining performance of high thermal conductivity and low expansion silicon carbide dispersion-strengthened hypereutectic aluminum-silicon electronic packaging materials to meet the needs of aviation,aerospace,and electronic packaging fields.We used the powder metallurgy method and high-temperature hot pressing technology to prepare SiC/Al-Si composite materials with different SiC contents(5vol%,10vol%,15vol%,and 20vol%).The results showed that as the SiC content increased,the tensile strength of the composite material first increased and then decreased.The tensile strength was the highest when the SiC content was 15%;the sintering temperature significantly affected the composite material’s structural density and mechanical properties.Findings indicated 700℃was the optimal sintering and the optimal SiC content of SiC/Al-Si composite materials was between 10%and 15%.Besides,the sintering temperature should be strictly controlled to improve the material’s structural density and mechanical properties.展开更多
Based on the deepening awareness of the risk of changing packaging materials of injections,the national regulatory authorities and the China National Pharmaceutical Packaging Association have issued the relevant guide...Based on the deepening awareness of the risk of changing packaging materials of injections,the national regulatory authorities and the China National Pharmaceutical Packaging Association have issued the relevant guidelines and group standards for changing packaging materials in recent years,greatly improving the research and development and technical requirements of packaging materials of injections.In 2021,Guangdong Province carried out the archival examination of the change of listed drugs,among which the proportion of the acceptance of changed injection packaging materials has increased year by year.On the basis of sorting out the archival examination work and combining with the cases of changing packaging materials of chemical injections accepted by Guangdong Province during 2021-2022,the requirements and problems of archival examination were analyzed and discussed to provide a reference and idea for applicants when studying the change in packaging materials.展开更多
Thermal property is one of the most important properties of light-emitting diode （LED）. Thermal property of LED packaging material determines the heat dissipations of the phosphor and the chip surface, accordingly h...Thermal property is one of the most important properties of light-emitting diode （LED）. Thermal property of LED packaging material determines the heat dissipations of the phosphor and the chip surface, accordingly having an influence on the light-emitting efficiency and the life-span of the device. In this paper, photoacoustic piezoelectric （PAPE） technique has been employed to investigate the thermal properties of polyvinyl alcohol （]？VA） and silicon dioxide, which are the new and the traditional packaging materials in white LED, respectively. Firstly, the theory of PAPE technique has been developed for two-layer model in order to investigate soft materials; secondly, the experimental system has been set up and adjusted by measuring the reference sample; thirdly, the thermal diffusivities of PVA and silicon dioxide are measured and analysed. The experimental results show that PVA has a higher thermal diffusivity than silicon dioxide and is a better packaging material in the sense of thermal diffusivity for white LED.展开更多
Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics.Unfortunately,paper is a combustible material,and thus exploring environment-friendly flame retar...Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics.Unfortunately,paper is a combustible material,and thus exploring environment-friendly flame retardant for paper-based archive packaging material plays an important role.Herein,boric acid,borax and disodium octaborate are used to modify the craft paper-based packaging materials for archive conservation to improve fire safety.The modified craft paper exhibits much higher flame retardancy than the pristine one dose based on vertical burning tests,without much influence on mechanical properties such as tensile strength and elongation at break.Thermogravimetric analysis(TGA),scanning electron microscope(SEM),and X-ray photoelectron spectroscopy(XPS)reveal that porous glass structure is formed during the combustion,because thermal decomposition of boric acid,borax and disodium octaborate will produce porous glassy matter as B_(2)O_(3).The porous glass covers the paper surface as an insulating layer which retards the further pyrolysis and combustion,resulting in a denser carbon layer.Our study provides a robust way to reduce the fire hazard of the archive packaging material by applying environment-friendly boron-based fire retardants.展开更多
A polymer-based carbon nano-tubes (CNTs) composite with high electromagnetic (EM) wave shielding effectiveness (SE) and with high mechanical property is developed for packaging of electronic modulus or devices.The ...A polymer-based carbon nano-tubes (CNTs) composite with high electromagnetic (EM) wave shielding effectiveness (SE) and with high mechanical property is developed for packaging of electronic modulus or devices.The liquid crystal polymers (LCP) and melamine formaldehydes (MF) polymer are used to study the orientation effect of CNTs in various polymeric matrix.The influences of orientation,aspect ratio,and mass fraction of CNTs upon the shielding effectiveness (SE) of CNTs-composites are investigated.The higher the orientation,aspect ratio,and weight percentages of nano-materials are, the higher the SE of the carbon composites.The highest SE for the CNTs/LCP nano composite obtained is more than 62 dB. This results may lead to the developing for CPU IC chip packaging.展开更多
In this study kokum rind dried by different methods,i.e.open air sun drying,solar drying and the convective hot air drying(60℃)was taken after being packaged in gunny bags,nylon bags and plastic jars for storage stud...In this study kokum rind dried by different methods,i.e.open air sun drying,solar drying and the convective hot air drying(60℃)was taken after being packaged in gunny bags,nylon bags and plastic jars for storage study upto nine months.The effect of different drying methods on quality parameters i.e.acidity,pH,TSS,reducing sugar,non-reducing sugar,colour(L,a and b)and calorific value of the stored product were evaluated.The quality parameters were tested at three-month intervals.Among three packaging materials,plastic jar was found best for kokum rind storage upto nine months as compared with nylon and gunny bags.Deterioration occurred as changes in acidity,non-reducing sugar,lightness,redness and calorific value over the storage period from the 0^(th) to the 9^(th) month.However,the TSS and b value increased as storage duration extended.展开更多
The serious problems caused by extensive usage of petroleum-based plastic materials led to investigating the comprehensive studies and developing active food packaging materials.Even if the chitosan-based films are co...The serious problems caused by extensive usage of petroleum-based plastic materials led to investigating the comprehensive studies and developing active food packaging materials.Even if the chitosan-based films are considered an attractive source,they exhibit some practical difficulties in developing active food packaging applications.Hence,Ficus carica Linn leaves extract(FLE),with the features of its cheapness,easy accessibility and superoxide anion radical scavenging activity,was incorporated into chitosan(CS)film at various concentrations(2%-6%w/w).To the best of our knowledge,this was the first time that FLE was utilized as a bioactive substance incorporated into chitosan films to develop eco-friendly,biodegradable,active food packaging material.The results obtained revealed that FLE incorporation into chitosan films significantly improved the swelling,water solubility and opacity of neat chitosan films.FTIR and morphological analysis indicated that the films produced exhibited smooth structure with homogenous dispersion of FLE.In mechanically,the addition of FLE resulted in a significant reduction in tensile strength while the elasticity of the films was improved.Additionally,the antioxidant and biodegradability properties of neat chitosan films were enhanced significantly.It was concluded that CS-FLE films appeared to be a capable and enhanced option for synthetic polymer-based food packaging materials.Based on the analyses performed,further studies are suggested on the packaging application for various foods and to evaluate the possible interaction of packaging film materials with the compounds of the food products,to avoid possible negative effects.展开更多
Synthetic polymers are the most widely used materials for packaging because of their ease of processing,low cost,and low density.However,many of these materials are not easily recyclable and are difficult to degrade c...Synthetic polymers are the most widely used materials for packaging because of their ease of processing,low cost,and low density.However,many of these materials are not easily recyclable and are difficult to degrade completely in nature,creating environmental problems.Thus,there is a tendency to substitute such polymers with natural polymers and copolymers that are easily bio-degraded and less likely to cause environmental pollution.There has been a greater interest in poly-lactic acid(PLA),poly-hydroxyalkanoates(PHAs),cellulose and starch based polymers and copolymers as the emerging biodegradable material candidates for the future.This paper reviews the present state-of-the-art biodegradable polymers made from renewable resources and discusses the main features of their properties and design.展开更多
The effects of different grinding methods and packaging materials on qualities of fenugreek and black pepper powders were evaluated.Various parameters and their evaluation methods are as follows:change in colour deter...The effects of different grinding methods and packaging materials on qualities of fenugreek and black pepper powders were evaluated.Various parameters and their evaluation methods are as follows:change in colour determined using Chroma meter calorimeter,aroma and odour measured by sensory evaluation,and change in moisture measured using oven drying method.Packaging materials such as glass jar,steel jar,plastic jar,aluminum bag and poly bags were used for keeping ambient and cryogenically ground fenugreek and black pepper powders.Packed powders were stored in dry and cool places under ambient condition.Sensory evaluation revealed quality reduction in terms of colour,odour,flavour,aroma and acceptability for fenugreek and black pepper powder stored for a long term(6 months).However,glass jar and steel jar were found to be better containers for storing powders for longer storage period than other options.For practical applications,the present investigation on the deterioration behaviour of fenugreek and black pepper powder contributes to the design of a suitable grinder out of ball,hammer,rotor,and pin mill for spice grinding.The study also helps select a suitable packaging material or container to store spice powders.A method to assess the quality of stored powder and its deterioration with the storage time is provided.展开更多
Thermal cracking occurs in the plastic packaging materials due to the presence of moisturized micro-cavities in the material.The moisture resident in the micro-cavities gives rise to the internal vapor pressure that d...Thermal cracking occurs in the plastic packaging materials due to the presence of moisturized micro-cavities in the material.The moisture resident in the micro-cavities gives rise to the internal vapor pressure that drives the thermal expansion of micro-cavities as temperature rises.The plastic packaging materials are considered a class of thermo-hyperelastic materials,thus allowing the micro-cavities to thermally expand to the substantial extent before the cracking failure.The micro-cavities can be moisture-abundant(i.e.,wet) or substantially dry when cracking occurs.Cracking appears to be almost certain in the presence of wet cavities.The possibility of cracking in dry cavities turns to be two-sided:when the initial volume fraction of the micro-cavities is relatively small,cracking cannot occur in the dry cavities regardless of the phase transition temperature;when the initial cavity volume fraction is relatively large,cracking tends to occur in the dry cavities especially when the phase transition temperature is large.Because of the two-sided cracking possibility,the dry-cavity cracking mode presents a scenario that might reveal the mechanism of popcorning-type cracking failure in plastic packaging materials.展开更多
Wood packaging waste with a high recycling value is one of the main components of packaging waste.However,most research has been focused on natural wood,and less is known about the recycling of wood-based panel waste ...Wood packaging waste with a high recycling value is one of the main components of packaging waste.However,most research has been focused on natural wood,and less is known about the recycling of wood-based panel waste commonly used in packaging.This paper examined the pyrolysis of common urea-formaldehyde(UF)resin particleboard,including the decomposition characteristics of its nitrogen-containing adhesives,the product types,and how they are generated.The samples and pyrolysis products were analyzed by infrared spectroscopy.The results showed that the UF resin was the main contributor to the release of ammonia(NH3)and hydrogen cyanide(HCN).At low temperatures,more NH3 was released than the HCN,and at high temperatures,the reverse was true.A high heating rate promoted the release of the NH_(3) and HCN.The UF resin and wood in the particleboard interacted and caused the release of the NH3 and HCN.These results provide a reference for further study of the thermochemical regeneration of wood-based packaging waste.展开更多
The rapid development of the electronic information industry brings to the irreplaceable role of electronic components, therefore the search of a more reliable packaging material has become increasingly important. In ...The rapid development of the electronic information industry brings to the irreplaceable role of electronic components, therefore the search of a more reliable packaging material has become increasingly important. In the electronic packaging system, the failure phenomenon caused by residual stress is one of the key factors restricting the development of electronic packaging technology. In order to use the in-situ characterization technology to explore the residual stress inducing mechanism and failure mechanism of epoxy-based advanced packaging materials, this paper gives a review of related previous research, and lays a theoretical foundation for the upcoming research. The classification and generation mechanism of residual stress are clarified in this paper, which provides data support for future related research.展开更多
This study was conducted to investigate the effects of different packaging methods on seed germination and vigor under a long-term bank storage condition, selecting suitable packaging materials and methods, and compre...This study was conducted to investigate the effects of different packaging methods on seed germination and vigor under a long-term bank storage condition, selecting suitable packaging materials and methods, and comprehensively estimate changes in seed vigor of seeds stored with different packaging materials. Hibiscus cannabinus L. seeds were stored in aluminium box, seed box, glass bottle, POlyethylene film bag, sack and kraft paper bag as packaging materials in a, long-term bank and tested for their seeds germinability, electrical conductivity and field seedling rate after 31 years. The results showed that the kenaf seeds with an initial germination rate of 88% exhibited the germination rates over 79.7% after being stored in the 6 packaging materials for 31 years, the germination rates of seeds packaged with paper bag and sack and of those sealed in film bag and aluminium box showed significantly decreased germination rates, while the seeds sealed in seed boxes and glass bottles exhibited non-significant decreases in seed germination rate, and their germination rates were still above 85%. Seed box and glass bottle were the packaging materials most suitable for long-term safe storage of kenaf seeds with a safe storage period long than 31 years.展开更多
Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious an...Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious and rare metals but also organic packaging materials.In previous studies,LED recycling focused on recovering precious and strategic metals while ignoring harmful substances such as organic packaging materials.Unlike crushing and other traditional methods,hydrothermal treatment can provide an environment-friendly process for decomposing packaging materials.This work developed a closed reaction vessel,where the degradation rate of plastic polyphthalamide(PPA)was close to 100%,with nano-TiO_(2)encapsulated in plastic PPA being efficiently recovered,while metals contained in LED were also recycled efficiently.Besides,the role of water in plastic PPA degradation that has been overlooked in current studies was explored and speculated in detail in this work.Environmental impact assessment revealed that the proposed recycling route for waste LED could significantly reduce the overall environmental impact compared to the currently published processes.Especially the developed method could reduce more than half the impact of global warming.Furthermore,this research provides a theoretical basis and a promising method for recycling other plastic-packaged e-waste devices,such as integrated circuits.展开更多
The Cu/Invar composites of 40% Cu were prepared by powder metallurgy, and the composites were rolled with 70% reduction and subsequently annealed at 750 ℃. Phases, microstructures and properties of the composites wer...The Cu/Invar composites of 40% Cu were prepared by powder metallurgy, and the composites were rolled with 70% reduction and subsequently annealed at 750 ℃. Phases, microstructures and properties of the composites were then studied. After that, the amount of a-Fe（Ni,Co） in the composites is reduced, because a-Fe（Ni,Co） partly transfers into y-Fe（Ni,Co） through the diffusion of the Ni atoms into a-Fe（Ni,Co） from Cu. When the rolling reduction is less than 40%, the deformation of Cu takes place, resulting in the movement of the Invar particles and the seaming of the pores. When the rolling reduction is in the range from 40% to 60%, the deformations of Invar and Cu occur simultaneously to form a streamline structure. After rolling till 70% and subsequent annealing, the Cu/Invar composites have fine comprehensive properties with a relative density of 98.6%, a tensile strength of 360 MPa, an elongation rate of 50%, a thermal conductivity of 25.42 W/（m.K） （as-tested） and a CTE of 10.79× 10-6/K （20-100 ℃）.展开更多
The current work explores the potential use of commercial Chinese bayberry tannin(BT)to develop antioxidant PVA-based films using solvent casting process for packaging applications.The effect of BT concentration on op...The current work explores the potential use of commercial Chinese bayberry tannin(BT)to develop antioxidant PVA-based films using solvent casting process for packaging applications.The effect of BT concentration on opa-city,water resistance and antioxidant capacity of resulting films was investigated.Properties like tensile strength,thermal behavior,and morphological aspects were also characterized.The experimental results showed that PVA/BT films formed with uniformly brown color and generally good transparency,offering good antioxidant ability.The PVA film containing BT presented slightly higher water resistance according to the results of moisture content and water vapor permeability,especially at low BT content(<10 wt%).The PVA can be compounded with up to 10 wt%BT without any obvious deterioration in the tensile strength.The PVA/BT films exhibited better thermal degradation behavior compared with PVA alone because of the chemical bonds of PVA-BT and the for-mation of char at high temperature.Based on the results,PVA incorporated with Chinese bayberry tannin may provide broader formulation options for packaging materials with antioxidant action.展开更多
A novel type of ZnO-Al2O3-B2O3-SiO2 glass-ceramics sealing to Kovar in electronic packaging was developed, whose thermal expansion coefficient and electrical resistance are 5.2× 10^-6/℃ and over 1×10^13 Ω&...A novel type of ZnO-Al2O3-B2O3-SiO2 glass-ceramics sealing to Kovar in electronic packaging was developed, whose thermal expansion coefficient and electrical resistance are 5.2× 10^-6/℃ and over 1×10^13 Ω·cm, respectively. The major crystalline phases in the glass-ceramic seals were ZnAl2O4, ZnB2O4, and NaSiAl2O4. The dielectric resistance of the glass-ceramic could be remarkably enhanced through the control of alkali metal ions into crystal lattices. It was found that crystallization happened first on the surface of the sample, leaving the amorphous phase in the inner, which made the glass suitable for sealing. The glass-ceramic showed better wetting on the Kovar surface, and sealing atmosphere and temperature had great effect on the wetting angle. Strong interracial bonding was obtained, which was mainly attributed to the interracial reaction between SiO2 and FeO or Fe3O4.展开更多
Objective To evaluate the clinical value of basic infusion packaging materials for providing suggestions on formulating basic infusion volume procurement policies.Methods Combined with market data,questionnaire survey...Objective To evaluate the clinical value of basic infusion packaging materials for providing suggestions on formulating basic infusion volume procurement policies.Methods Combined with market data,questionnaire surveys were used to rank different basic infusion packaging materials.Pharmacists,nurses,and experts in the field of packaging respectively assess the safety,compatibility,effectiveness,convenience,and environmental friendliness of the materials.Results and Conclusion Products with the best clinical value have a lower market share than other products with average clinical value.The best three packaging materials only account for 15%of the market share.The order of clinical value from good to bad is inner-sealed polypropylene infusion bag(BFS)>soft aseptic bag with double valves and layers>upright polypropylene infusion bag>non-PVC soft bag>plastic bottle>glass bottle.The order of market share is non-PVC soft bag>soft aseptic bag with double valves and layers>plastic bottle>vertical polypropylene infusion bag>inner-sealed polypropylene infusion bag(BFS)>glass bottle.Therefore,the clinical values of various basic infusion packaging materials are different.The following countermeasures are put forward such as separating bidding for basic infusions with different packaging materials,combining volume and price with procurement,and priority procurement of packaging materials with better clinical values.展开更多
Magnetics,ferroelectrics,and multiferroics have attracted great attentions because they are not only extremely im-portant for investigating fundamental physics,but also have important applications in information techn...Magnetics,ferroelectrics,and multiferroics have attracted great attentions because they are not only extremely im-portant for investigating fundamental physics,but also have important applications in information technology.Here,recent computational studies on magnetism and ferroelectricity are reviewed.We first give a brief introduction to magnets,fer-roelectrics,and multiferroics.Then,theoretical models and corresponding computational methods for investigating these materials are presented.In particular,a new method for computing the linear magnetoelectric coupling tensor without applying an external field in the first principle calculations is proposed for the first time.The functionalities of our home-made Property Analysis and Simulation Package for materials(PASP)and its applications in the field of magnetism and ferroelectricity are discussed.Finally,we summarize this review and give a perspective on possible directions of future computational studies on magnetism and ferroelectricity.展开更多
In the post-Moore era,the development of active phased array antennas will inevitably trend towards active array microsystems.In this paper,the characteristics and composition of the active array antenna are briefly d...In the post-Moore era,the development of active phased array antennas will inevitably trend towards active array microsystems.In this paper,the characteristics and composition of the active array antenna are briefly described.Owing to the high efficiency,low profile,and light weight of the active array microsystems,the application prospects and advantages in the engineering of multi-functional airborne radar,spaceborne radar,and communication systems are analyzed.Moreover,according to the characteristics of the post-Moore era of integrated circuits,scientific and technological problems in the active array microsystems are presented,including multi-scale,multi-signal,and multi-physics field coupling.The challenges are also discussed,such as new architectures and algorithms,miniaturization of passive components,novel materials and processes,ultra-wideband technology,and new interdisciplinary technological applications.This paper is expected to inspire in-depth research on active array microsystems.展开更多
文摘The objective of this study is to improve the mechanical properties and machining performance of high thermal conductivity and low expansion silicon carbide dispersion-strengthened hypereutectic aluminum-silicon electronic packaging materials to meet the needs of aviation,aerospace,and electronic packaging fields.We used the powder metallurgy method and high-temperature hot pressing technology to prepare SiC/Al-Si composite materials with different SiC contents(5vol%,10vol%,15vol%,and 20vol%).The results showed that as the SiC content increased,the tensile strength of the composite material first increased and then decreased.The tensile strength was the highest when the SiC content was 15%;the sintering temperature significantly affected the composite material’s structural density and mechanical properties.Findings indicated 700℃was the optimal sintering and the optimal SiC content of SiC/Al-Si composite materials was between 10%and 15%.Besides,the sintering temperature should be strictly controlled to improve the material’s structural density and mechanical properties.
基金Supported by the Research on the Archival Examination Strategy of changes in Listed Drugs Based on Risk under the Guidance of Holders'Principal Responsibility(2023TDZ01)。
文摘Based on the deepening awareness of the risk of changing packaging materials of injections,the national regulatory authorities and the China National Pharmaceutical Packaging Association have issued the relevant guidelines and group standards for changing packaging materials in recent years,greatly improving the research and development and technical requirements of packaging materials of injections.In 2021,Guangdong Province carried out the archival examination of the change of listed drugs,among which the proportion of the acceptance of changed injection packaging materials has increased year by year.On the basis of sorting out the archival examination work and combining with the cases of changing packaging materials of chemical injections accepted by Guangdong Province during 2021-2022,the requirements and problems of archival examination were analyzed and discussed to provide a reference and idea for applicants when studying the change in packaging materials.
基金Project supported by the National Nature Science Foundation of China (Grant No. 50506006)the National High Technology Research and Development Program of China (Grant No. 2006AA03A116)the Youth Foundation of University of Electronic Science and Technology of China (Grant No. JX05024)
文摘Thermal property is one of the most important properties of light-emitting diode （LED）. Thermal property of LED packaging material determines the heat dissipations of the phosphor and the chip surface, accordingly having an influence on the light-emitting efficiency and the life-span of the device. In this paper, photoacoustic piezoelectric （PAPE） technique has been employed to investigate the thermal properties of polyvinyl alcohol （]？VA） and silicon dioxide, which are the new and the traditional packaging materials in white LED, respectively. Firstly, the theory of PAPE technique has been developed for two-layer model in order to investigate soft materials; secondly, the experimental system has been set up and adjusted by measuring the reference sample; thirdly, the thermal diffusivities of PVA and silicon dioxide are measured and analysed. The experimental results show that PVA has a higher thermal diffusivity than silicon dioxide and is a better packaging material in the sense of thermal diffusivity for white LED.
文摘Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics.Unfortunately,paper is a combustible material,and thus exploring environment-friendly flame retardant for paper-based archive packaging material plays an important role.Herein,boric acid,borax and disodium octaborate are used to modify the craft paper-based packaging materials for archive conservation to improve fire safety.The modified craft paper exhibits much higher flame retardancy than the pristine one dose based on vertical burning tests,without much influence on mechanical properties such as tensile strength and elongation at break.Thermogravimetric analysis(TGA),scanning electron microscope(SEM),and X-ray photoelectron spectroscopy(XPS)reveal that porous glass structure is formed during the combustion,because thermal decomposition of boric acid,borax and disodium octaborate will produce porous glassy matter as B_(2)O_(3).The porous glass covers the paper surface as an insulating layer which retards the further pyrolysis and combustion,resulting in a denser carbon layer.Our study provides a robust way to reduce the fire hazard of the archive packaging material by applying environment-friendly boron-based fire retardants.
文摘A polymer-based carbon nano-tubes (CNTs) composite with high electromagnetic (EM) wave shielding effectiveness (SE) and with high mechanical property is developed for packaging of electronic modulus or devices.The liquid crystal polymers (LCP) and melamine formaldehydes (MF) polymer are used to study the orientation effect of CNTs in various polymeric matrix.The influences of orientation,aspect ratio,and mass fraction of CNTs upon the shielding effectiveness (SE) of CNTs-composites are investigated.The higher the orientation,aspect ratio,and weight percentages of nano-materials are, the higher the SE of the carbon composites.The highest SE for the CNTs/LCP nano composite obtained is more than 62 dB. This results may lead to the developing for CPU IC chip packaging.
文摘In this study kokum rind dried by different methods,i.e.open air sun drying,solar drying and the convective hot air drying(60℃)was taken after being packaged in gunny bags,nylon bags and plastic jars for storage study upto nine months.The effect of different drying methods on quality parameters i.e.acidity,pH,TSS,reducing sugar,non-reducing sugar,colour(L,a and b)and calorific value of the stored product were evaluated.The quality parameters were tested at three-month intervals.Among three packaging materials,plastic jar was found best for kokum rind storage upto nine months as compared with nylon and gunny bags.Deterioration occurred as changes in acidity,non-reducing sugar,lightness,redness and calorific value over the storage period from the 0^(th) to the 9^(th) month.However,the TSS and b value increased as storage duration extended.
文摘The serious problems caused by extensive usage of petroleum-based plastic materials led to investigating the comprehensive studies and developing active food packaging materials.Even if the chitosan-based films are considered an attractive source,they exhibit some practical difficulties in developing active food packaging applications.Hence,Ficus carica Linn leaves extract(FLE),with the features of its cheapness,easy accessibility and superoxide anion radical scavenging activity,was incorporated into chitosan(CS)film at various concentrations(2%-6%w/w).To the best of our knowledge,this was the first time that FLE was utilized as a bioactive substance incorporated into chitosan films to develop eco-friendly,biodegradable,active food packaging material.The results obtained revealed that FLE incorporation into chitosan films significantly improved the swelling,water solubility and opacity of neat chitosan films.FTIR and morphological analysis indicated that the films produced exhibited smooth structure with homogenous dispersion of FLE.In mechanically,the addition of FLE resulted in a significant reduction in tensile strength while the elasticity of the films was improved.Additionally,the antioxidant and biodegradability properties of neat chitosan films were enhanced significantly.It was concluded that CS-FLE films appeared to be a capable and enhanced option for synthetic polymer-based food packaging materials.Based on the analyses performed,further studies are suggested on the packaging application for various foods and to evaluate the possible interaction of packaging film materials with the compounds of the food products,to avoid possible negative effects.
基金support from the NSERC Strategic Network-Innovative Green Wood Fibre Product(Canada)Natural Science Foundation of China(Grant No.21466005)are gratefully acknowledged.
文摘Synthetic polymers are the most widely used materials for packaging because of their ease of processing,low cost,and low density.However,many of these materials are not easily recyclable and are difficult to degrade completely in nature,creating environmental problems.Thus,there is a tendency to substitute such polymers with natural polymers and copolymers that are easily bio-degraded and less likely to cause environmental pollution.There has been a greater interest in poly-lactic acid(PLA),poly-hydroxyalkanoates(PHAs),cellulose and starch based polymers and copolymers as the emerging biodegradable material candidates for the future.This paper reviews the present state-of-the-art biodegradable polymers made from renewable resources and discusses the main features of their properties and design.
文摘The effects of different grinding methods and packaging materials on qualities of fenugreek and black pepper powders were evaluated.Various parameters and their evaluation methods are as follows:change in colour determined using Chroma meter calorimeter,aroma and odour measured by sensory evaluation,and change in moisture measured using oven drying method.Packaging materials such as glass jar,steel jar,plastic jar,aluminum bag and poly bags were used for keeping ambient and cryogenically ground fenugreek and black pepper powders.Packed powders were stored in dry and cool places under ambient condition.Sensory evaluation revealed quality reduction in terms of colour,odour,flavour,aroma and acceptability for fenugreek and black pepper powder stored for a long term(6 months).However,glass jar and steel jar were found to be better containers for storing powders for longer storage period than other options.For practical applications,the present investigation on the deterioration behaviour of fenugreek and black pepper powder contributes to the design of a suitable grinder out of ball,hammer,rotor,and pin mill for spice grinding.The study also helps select a suitable packaging material or container to store spice powders.A method to assess the quality of stored powder and its deterioration with the storage time is provided.
基金supported by the National Natural Science Foundation of China (Grant No. 11172195)the Natural Science Foundation of Shanxi Province,China (Grant No. 2012011019-4)
文摘Thermal cracking occurs in the plastic packaging materials due to the presence of moisturized micro-cavities in the material.The moisture resident in the micro-cavities gives rise to the internal vapor pressure that drives the thermal expansion of micro-cavities as temperature rises.The plastic packaging materials are considered a class of thermo-hyperelastic materials,thus allowing the micro-cavities to thermally expand to the substantial extent before the cracking failure.The micro-cavities can be moisture-abundant(i.e.,wet) or substantially dry when cracking occurs.Cracking appears to be almost certain in the presence of wet cavities.The possibility of cracking in dry cavities turns to be two-sided:when the initial volume fraction of the micro-cavities is relatively small,cracking cannot occur in the dry cavities regardless of the phase transition temperature;when the initial cavity volume fraction is relatively large,cracking tends to occur in the dry cavities especially when the phase transition temperature is large.Because of the two-sided cracking possibility,the dry-cavity cracking mode presents a scenario that might reveal the mechanism of popcorning-type cracking failure in plastic packaging materials.
文摘Wood packaging waste with a high recycling value is one of the main components of packaging waste.However,most research has been focused on natural wood,and less is known about the recycling of wood-based panel waste commonly used in packaging.This paper examined the pyrolysis of common urea-formaldehyde(UF)resin particleboard,including the decomposition characteristics of its nitrogen-containing adhesives,the product types,and how they are generated.The samples and pyrolysis products were analyzed by infrared spectroscopy.The results showed that the UF resin was the main contributor to the release of ammonia(NH3)and hydrogen cyanide(HCN).At low temperatures,more NH3 was released than the HCN,and at high temperatures,the reverse was true.A high heating rate promoted the release of the NH_(3) and HCN.The UF resin and wood in the particleboard interacted and caused the release of the NH3 and HCN.These results provide a reference for further study of the thermochemical regeneration of wood-based packaging waste.
文摘The rapid development of the electronic information industry brings to the irreplaceable role of electronic components, therefore the search of a more reliable packaging material has become increasingly important. In the electronic packaging system, the failure phenomenon caused by residual stress is one of the key factors restricting the development of electronic packaging technology. In order to use the in-situ characterization technology to explore the residual stress inducing mechanism and failure mechanism of epoxy-based advanced packaging materials, this paper gives a review of related previous research, and lays a theoretical foundation for the upcoming research. The classification and generation mechanism of residual stress are clarified in this paper, which provides data support for future related research.
文摘This study was conducted to investigate the effects of different packaging methods on seed germination and vigor under a long-term bank storage condition, selecting suitable packaging materials and methods, and comprehensively estimate changes in seed vigor of seeds stored with different packaging materials. Hibiscus cannabinus L. seeds were stored in aluminium box, seed box, glass bottle, POlyethylene film bag, sack and kraft paper bag as packaging materials in a, long-term bank and tested for their seeds germinability, electrical conductivity and field seedling rate after 31 years. The results showed that the kenaf seeds with an initial germination rate of 88% exhibited the germination rates over 79.7% after being stored in the 6 packaging materials for 31 years, the germination rates of seeds packaged with paper bag and sack and of those sealed in film bag and aluminium box showed significantly decreased germination rates, while the seeds sealed in seed boxes and glass bottles exhibited non-significant decreases in seed germination rate, and their germination rates were still above 85%. Seed box and glass bottle were the packaging materials most suitable for long-term safe storage of kenaf seeds with a safe storage period long than 31 years.
基金supported by the National Natural Science Foundation of China(52270132).
文摘Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to reduce.As a new type of e-waste,LED is a double-edged sword,as it contains not only precious and rare metals but also organic packaging materials.In previous studies,LED recycling focused on recovering precious and strategic metals while ignoring harmful substances such as organic packaging materials.Unlike crushing and other traditional methods,hydrothermal treatment can provide an environment-friendly process for decomposing packaging materials.This work developed a closed reaction vessel,where the degradation rate of plastic polyphthalamide(PPA)was close to 100%,with nano-TiO_(2)encapsulated in plastic PPA being efficiently recovered,while metals contained in LED were also recycled efficiently.Besides,the role of water in plastic PPA degradation that has been overlooked in current studies was explored and speculated in detail in this work.Environmental impact assessment revealed that the proposed recycling route for waste LED could significantly reduce the overall environmental impact compared to the currently published processes.Especially the developed method could reduce more than half the impact of global warming.Furthermore,this research provides a theoretical basis and a promising method for recycling other plastic-packaged e-waste devices,such as integrated circuits.
文摘The Cu/Invar composites of 40% Cu were prepared by powder metallurgy, and the composites were rolled with 70% reduction and subsequently annealed at 750 ℃. Phases, microstructures and properties of the composites were then studied. After that, the amount of a-Fe（Ni,Co） in the composites is reduced, because a-Fe（Ni,Co） partly transfers into y-Fe（Ni,Co） through the diffusion of the Ni atoms into a-Fe（Ni,Co） from Cu. When the rolling reduction is less than 40%, the deformation of Cu takes place, resulting in the movement of the Invar particles and the seaming of the pores. When the rolling reduction is in the range from 40% to 60%, the deformations of Invar and Cu occur simultaneously to form a streamline structure. After rolling till 70% and subsequent annealing, the Cu/Invar composites have fine comprehensive properties with a relative density of 98.6%, a tensile strength of 360 MPa, an elongation rate of 50%, a thermal conductivity of 25.42 W/（m.K） （as-tested） and a CTE of 10.79× 10-6/K （20-100 ℃）.
基金This work was supported by the National Natural Science Foundation of China(NSFC 31971595,31760187)the Program for Leading Talents of Science and Technology(Grant No.2017HA013)the Yunnan Provincial Reserve Talents for Middle&Young Academic and Technical Leaders(2019HB026),and the 111 Project.
文摘The current work explores the potential use of commercial Chinese bayberry tannin(BT)to develop antioxidant PVA-based films using solvent casting process for packaging applications.The effect of BT concentration on opa-city,water resistance and antioxidant capacity of resulting films was investigated.Properties like tensile strength,thermal behavior,and morphological aspects were also characterized.The experimental results showed that PVA/BT films formed with uniformly brown color and generally good transparency,offering good antioxidant ability.The PVA film containing BT presented slightly higher water resistance according to the results of moisture content and water vapor permeability,especially at low BT content(<10 wt%).The PVA can be compounded with up to 10 wt%BT without any obvious deterioration in the tensile strength.The PVA/BT films exhibited better thermal degradation behavior compared with PVA alone because of the chemical bonds of PVA-BT and the for-mation of char at high temperature.Based on the results,PVA incorporated with Chinese bayberry tannin may provide broader formulation options for packaging materials with antioxidant action.
基金supported by the National Natural Science Foundation of China (No.50274014, 50774005)the Major State Basic Research Development Program of China (No.2006CB605207)the National High-Tech Research and Development Program of China (No.2006AA03Z557)
文摘A novel type of ZnO-Al2O3-B2O3-SiO2 glass-ceramics sealing to Kovar in electronic packaging was developed, whose thermal expansion coefficient and electrical resistance are 5.2× 10^-6/℃ and over 1×10^13 Ω·cm, respectively. The major crystalline phases in the glass-ceramic seals were ZnAl2O4, ZnB2O4, and NaSiAl2O4. The dielectric resistance of the glass-ceramic could be remarkably enhanced through the control of alkali metal ions into crystal lattices. It was found that crystallization happened first on the surface of the sample, leaving the amorphous phase in the inner, which made the glass suitable for sealing. The glass-ceramic showed better wetting on the Kovar surface, and sealing atmosphere and temperature had great effect on the wetting angle. Strong interracial bonding was obtained, which was mainly attributed to the interracial reaction between SiO2 and FeO or Fe3O4.
文摘Objective To evaluate the clinical value of basic infusion packaging materials for providing suggestions on formulating basic infusion volume procurement policies.Methods Combined with market data,questionnaire surveys were used to rank different basic infusion packaging materials.Pharmacists,nurses,and experts in the field of packaging respectively assess the safety,compatibility,effectiveness,convenience,and environmental friendliness of the materials.Results and Conclusion Products with the best clinical value have a lower market share than other products with average clinical value.The best three packaging materials only account for 15%of the market share.The order of clinical value from good to bad is inner-sealed polypropylene infusion bag(BFS)>soft aseptic bag with double valves and layers>upright polypropylene infusion bag>non-PVC soft bag>plastic bottle>glass bottle.The order of market share is non-PVC soft bag>soft aseptic bag with double valves and layers>plastic bottle>vertical polypropylene infusion bag>inner-sealed polypropylene infusion bag(BFS)>glass bottle.Therefore,the clinical values of various basic infusion packaging materials are different.The following countermeasures are put forward such as separating bidding for basic infusions with different packaging materials,combining volume and price with procurement,and priority procurement of packaging materials with better clinical values.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11825403,12188101,and 11804138)the Natural Science Foundation of Anhui Province,China(Grant No.1908085MA10)the Opening Foundation of the State Key Laboratory of Surface Physics of Fudan University(Grant No.KF2019_07)。
文摘Magnetics,ferroelectrics,and multiferroics have attracted great attentions because they are not only extremely im-portant for investigating fundamental physics,but also have important applications in information technology.Here,recent computational studies on magnetism and ferroelectricity are reviewed.We first give a brief introduction to magnets,fer-roelectrics,and multiferroics.Then,theoretical models and corresponding computational methods for investigating these materials are presented.In particular,a new method for computing the linear magnetoelectric coupling tensor without applying an external field in the first principle calculations is proposed for the first time.The functionalities of our home-made Property Analysis and Simulation Package for materials(PASP)and its applications in the field of magnetism and ferroelectricity are discussed.Finally,we summarize this review and give a perspective on possible directions of future computational studies on magnetism and ferroelectricity.
基金Project supported by the National Natural Science Foundation of China(No.92373115)the Natural Science Foundation of Anhui Province,China(No.2308085MF193)+2 种基金the Major Natural Science Project of Anhui Provincial Education Department,China(No.KJ2021ZD0003)the Key Research and Development Project of Anhui Province,China(No.2023n06020026)the Innovation and Entrepreneurship of Anhui Province,China(No.Z020118060)。
文摘In the post-Moore era,the development of active phased array antennas will inevitably trend towards active array microsystems.In this paper,the characteristics and composition of the active array antenna are briefly described.Owing to the high efficiency,low profile,and light weight of the active array microsystems,the application prospects and advantages in the engineering of multi-functional airborne radar,spaceborne radar,and communication systems are analyzed.Moreover,according to the characteristics of the post-Moore era of integrated circuits,scientific and technological problems in the active array microsystems are presented,including multi-scale,multi-signal,and multi-physics field coupling.The challenges are also discussed,such as new architectures and algorithms,miniaturization of passive components,novel materials and processes,ultra-wideband technology,and new interdisciplinary technological applications.This paper is expected to inspire in-depth research on active array microsystems.
