Organic solar cells based on poly（N-vinylcarbazole） （PVK）： porphyrin： tris （8-hydroxyquinolinato） aluminium （Alq3） blend p-n junction systems have been fabricated in this work. The roles of the different com...Organic solar cells based on poly（N-vinylcarbazole） （PVK）： porphyrin： tris （8-hydroxyquinolinato） aluminium （Alq3） blend p-n junction systems have been fabricated in this work. The roles of the different components in the blend system and of the amount of porphyrin have been investigated. The 5, 10, 15, 20-tetraphenylporphyrin （TPP） and 5, 10, 15, 20-tetra（o-chloro）phenylporphyrinato-copper （CuTC1PP） are used in the solar cells. The results show that TPP is better than CuTC1PP in enhancing the performance of PVK：Alq3 solar cells. When the weight ratio of PVK：TPP：Alq3 is 1：1.5：1, the best performance of solar cell is obtained. The open circuit voltage （Voc） is 0.87 V, and the short circuit current （Jsc） is 17.5 μA·cm-2. In the ternary bulk hereojunction system, the device may be regarded as a cascade of three devices of PVK：TPP, TPP：Alq3 and PVK：Alq3. PVK, TPP and Alq3 can improve the hole mobility, light absorption intensity and electron mobility of the ternary bulk hereojunction system, respectively.展开更多
Embedding a third and/or fourth component into a binary blend active layer of organic photovoltaics (OPVs) is a promising approach to achieve high-performance photovoltaic cells and modules. This multicomponent strate...Embedding a third and/or fourth component into a binary blend active layer of organic photovoltaics (OPVs) is a promising approach to achieve high-performance photovoltaic cells and modules. This multicomponent strategy favors absorption broadening via additional components. Quaternary OPV (QOPV) blends have four components in three possible configurations: (i) a donor and three acceptors, (ii) two donors and two acceptors, or (iii) three donors and an acceptor. Although quaternary systems have only been relatively recently studied compared to other systems in OPVs, leveraging the synergistic effects of the four components leads to record power conversion efficiencies, currently approaching 20%. QOPVs provide ample material choices for compatibility and channels for charge transfer mechanisms, possibly leading to optimized morphology and orientation. Reviewing recent progress in advancing QOPVs is essential for understanding their contribution to the OPV field. The review mainly discusses research progress in QOPVs with a keen interest in their various configurations, semitransparency, and outdoor and indoor applications. It describes the not-well-understood QOPV's general working mechanism. This review explores high-performance QOPVs based on the fourth component's contribution as a donor, acceptor, or dye molecule and beyond in photovoltaic applications. Finally, there is a discussion around QOPV's outlook and projected future research directions in this field. This review intends to provide an overview of the quaternary systems approach to OPVs and inform current and future researchers on investigating the full spectrum of OPVs.展开更多
In this research, we report a bulk heterojunction（BHJ） solar cell consisting of a ternary blend system. Poly（3-hexylthiophene） P3 HT is used as a donor and [6,6]-phenyl C61-butyric acid methylester（PCBM） plays t...In this research, we report a bulk heterojunction（BHJ） solar cell consisting of a ternary blend system. Poly（3-hexylthiophene） P3 HT is used as a donor and [6,6]-phenyl C61-butyric acid methylester（PCBM） plays the role of acceptor whereas vanadyl 2,9,16,23-tetraphenoxy-29 H, 31H-phthalocyanine（VOPc Ph O） is selected as an ambipolar transport material. The materials are selected and assembled in such a fashion that the generated charge carriers could efficiently be transported rightwards within the blend. The organic BHJ solar cells consist of ITO/PEDOT：PSS/ternary BHJ blend/Al structure. The power conversion efficiencies of the ITO/ PEDOT：PSS/P3HT：PCBM/Al and ITO/PEDOT：PSS/P3HT：PCBM：VOPcPhO/Al solar cells are found to be 2.3% and 3.4%, respectively.展开更多
We investigated the phase behavior of diblock copolymer AB/homopolymer C blends in concentrated aqueous solutions using a simulated annealing method.Phase diagrams were constructed as a function of the concentration o...We investigated the phase behavior of diblock copolymer AB/homopolymer C blends in concentrated aqueous solutions using a simulated annealing method.Phase diagrams were constructed as a function of the concentration of all polymers(Φ)and the volume fraction of homopolymer(fC).Rich phase transition sequences were observed,especially reentrant phase transitions,such as lamellae→inverted cylinders→gyroids→lamellae→disorder,for a givenΦwith increasing fC.By analyzing the variations in the average contact numbers between different components and the effective volume fractions of B-domains,we elucidated the mechanisms of the reentrant phase transitions.We found that the strong attraction between B and C leads to the swelling of B-domains upon addition of homopolymer.Concurrently,the solvent preferentially swells the A-domains over the B+C-domains.The competing swelling effects of the solvent and homopolymer on the A-domains and B-domains,respectively,triggered the reentrant phase behavior in the symmetric AB copolymer system upon addition of homopolymer.展开更多
A polylactide(PLA)blend with simultaneous enhancement of strength,toughness,and heat resistance was successfully achieved by adding biodegradable poly(propylene carbonate)(PPC)and uniaxial pre-stretching.The effects o...A polylactide(PLA)blend with simultaneous enhancement of strength,toughness,and heat resistance was successfully achieved by adding biodegradable poly(propylene carbonate)(PPC)and uniaxial pre-stretching.The effects of the PPC content(0 wt%-50 wt%)on the phase morphology and performance of the blends before and after pre-stretching were systematically investigated.Blending PPC initially reduced the strength,modulus,and heat resistance,but pre-stretching significantly enhanced these properties.In blends containing≤30 wt%PPC,where PPC formed a well-dispersed island-like phase within the PLA matrix,pre-stretching simultaneously enhanced strength,toughness,and heat resistance.The optimized pre-stretched 70/30 PLA/PPC(ps-70/30)blend achieved exceptional performance:tensile strength increased from 66.9MPa to 84.5 MPa,elongation at break dramatically improved from 6.8%to 115.1%,impact strength reached 55.1 k J/m^(2)(far exceeding neat PLA's 3.5 k J/m^(2)),and Vicat softening temperature(VST)increased by 60.6%to 101.8℃.Notably,the ps-70/30 blend retained excellent mechanical properties even after six months of aging.These improvements were attributed to the synergistic effects of the PPC incorporation and prestretching.PPC not only promoted the high orientation of the PLA molecular chains but also facilitated the formation of a stable crystalline phase during pre-stretching,thereby enhancing both the mechanical properties and heat resistance.However,when the PPC content exceeded 30wt%,phase inversion occurred,resulting in a continuous amorphous PPC phase that degraded the overall performance.This study demonstrated that a combination of controlled PPC incorporation and pre-stretching can effectively overcome PLA's brittleness of PLA while improving its heat resistance,offering a promising strategy for developing high-performance,fully biodegradable PLA materials suitable for industrial applications.展开更多
To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt b...To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt by physical property index,microscopic morphology,rheological testing,and infrared spectroscopy on multiple scales.The results show that the best preparation process for TB-modified asphalt is stirring at 260℃ for 4 h at 400 rpm,which significantly reduces the modification time of the asphalt.From a physical property viewpoint,the TB composite-modified asphalt sample with 5% styrene-butadiene-styrene(SBS)+1% aromatics+0.1% sulfur exhibits high-comprehensive,high-and low-temperature properties.More-over,its crosslinked mesh structure comprises black rubber particles uniformly interwoven in the middle,which further enhances the performance of the asphalt and results in an excellent performance formulation.In addition,the sample with 5%SBS content has a higher G*value and smaller δ value than that with 3%SBS content,indicating that its high-temperature resistance is improved.The effect of adding 3%SBS content on the viscoelastic ratio is,to some extent,less than that caused by 20% rubber powder.展开更多
A new principle for producing fire-resistant polymer materials with increased deformation properties using a flame retardant not as a heterogeneous additive,but as a thermoplastic flame retardant in a hybrid polymer m...A new principle for producing fire-resistant polymer materials with increased deformation properties using a flame retardant not as a heterogeneous additive,but as a thermoplastic flame retardant in a hybrid polymer mixture with a polyhydrocarbon is considered.Hybrid polymer blends of low-molecular ammonium polyphosphate(APP)with an ethylene-vinyl acetate copolymer(EVA)with an APP content of 80 wt%with enhanced deformation properties were obtained by extrusion mixing at various temperatures in the range from 200°C to 250°C.A chemical scheme for the transformations of the components during the formation of the composite is proposed.X-ray diffraction analysis showed the formation of new crystalline structures of APP.The phase structure of the systems corresponding to the model of a dispersed-filled composite in which EVA plays the role of a matrix,determining the deformation of the mixture,and the filler is ammonium polyphosphate,was studied by scanning electron microscopy(SEM).The method of FTIR microscopy showed chemical interactions between EVA and APP with the formation of amide groups.The conditions for obtaining compositions characterized by heat resistance of 210°C,oxygen index of 55 and ultimate elongation at drawing of 213%were established.展开更多
Rubber-toughened thermoplastic materials have become ubiquitous in modern society owing to their lightweight nature and desirable combination of advantageous performances.Despite the ever-increasing demand,the develop...Rubber-toughened thermoplastic materials have become ubiquitous in modern society owing to their lightweight nature and desirable combination of advantageous performances.Despite the ever-increasing demand,the development of polymer alloys that are lightweight,high-strength,and high-toughness remains an ongoing challenge.Inspired by the unique“salami”microstructure from commercial acrylonitrile butadiene styrene copolymer(ABS)and high-impact polystyrene(HIPS),a facile approach was developed to overcome the trade-off between enhancing the toughness and rigidity of fully polymer-based alloys by virtue of elastomeric salami particles.This strategy entails pre-grafting rigid poly(lactic acid)(PLLA)chains with glycidyl methacrylate-grafted octene ethylene copolymer(POE-g-GMA)using complementary reactive groups.It can be envisaged that the PLLA grafts featuring strong incompatibility with polypropylene(PP)remain fixed in elastomer phase upon the subsequent melt compounding,facilitating the in situ formation of“hard core(PLLA)-soft shell(polyolefin elastomer,POE)”particles in polypropylene(PP)matrix.The all-polymer alloys containing elastomeric salami particles demonstrated unprecedented performance combinations,including upper notched impact strengths(56.8 kJ/m2),even higher tensile strength(36.8 MPa),and Young’s modulus(0.93 GPa)than that of the PP matrix.Furthermore,these materials are lightweight without the incorporation of reinforcing nano-fillers,which is competitive with industrial engineering plastics.It is highly anticipated that this universal and highly efficient protocol will be appropriate for arbitrary rubber toughened/reinforced systems,offering a paradigm in the design of advanced all-polymer alloys.展开更多
In mixture experiments,the observed response is determined by the relative proportions of the components,consequently rendering the experimental region a simplex.This paper focuses primarily on the optimal designs of ...In mixture experiments,the observed response is determined by the relative proportions of the components,consequently rendering the experimental region a simplex.This paper focuses primarily on the optimal designs of mixture experiments that involve process variables.Prior research has extensively delved into optimal orthogonal block designs for some classic mixture models with process variables.Based on the framework of general blending models,this paper proposes a class of symmetric linear mixture models,which can be regarded as a generalization of many existing ones.Under the orthogonal blocking conditions,orthogonal block designs are devised through Latin squares in the presence of process variables.TheD-,A-,and E-optimality criteria are utilized to obtain optimal designs at the boundary of the simplex in the case of 3 components.As the values of the exponents change,numerically derived optimal design points are presented to illustrate the pattern of their variations,and to verify the consistency of the results with previous research on some specific symmetric general blending models.展开更多
The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behav...The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.展开更多
An initial conditions （ICs） perturbation method was developed with the aim to improve an operational regional ensemble prediction system （REPS）. Three issues were identified and investigated： （1） the impacts of...An initial conditions （ICs） perturbation method was developed with the aim to improve an operational regional ensemble prediction system （REPS）. Three issues were identified and investigated： （1） the impacts of perturbation scale on the ensemble spread and forecast skill of the REPS; （2） the scale characteristic of the IC perturbations of the REPS; and （3） whether the REPS＇s skill could be improved by adding large-scale information to the IC perturbations. Numerical experiments were conducted to reveal the impact of perturbation scale on the ensemble spread and forecast skill. The scales of IC perturbations from the REPS and an operational global ensemble prediction system （GEPS） were analyzed. A ＂multi-scale blending＂ （MSB） IC perturbation scheme was developed, and the main findings can be summarized as follows： The growth rates of the ensemble spread of the REPS are sensitive to the scale of the IC perturbations; the ensemble forecast skills can benefit from large-scale perturbations; the global ensemble IC perturbations exhibit more power at larger scales, while the regional ensemble IC perturbations contain more power at smaller scales; the MSB method can generate IC perturbations by combining the small-scale component from the REPS and the large-scale component from the GEPS; the energy norm growth of the MSB-generated perturbations can be appropriate at all forecast lead times; and the MSB-based REPS shows higher skill than the original system, as determined by ensemble forecast verification.展开更多
Using GIS, GPS and GPRS, a dynamic management system of ore blending in an open pit mine has been designed and developed. A linear program was established in a practical application. The system is very good at automat...Using GIS, GPS and GPRS, a dynamic management system of ore blending in an open pit mine has been designed and developed. A linear program was established in a practical application. The system is very good at automatically drawing up a daily production plan of ore blending and monitors and controls the process of mining production in real time. Experiments under real conditions show that the performance of this system is stable and can satisfy production standards of ore blending in open pit mines.展开更多
A series of polymer blends were prepared from 1,3-bis（3,4-dicyanophenoxy）benzene（3 BOCN） and epoxy resin with methyl tetrahydrophthalic anhydride as curing agent. The curing behavior and curing kinetics of the ble...A series of polymer blends were prepared from 1,3-bis（3,4-dicyanophenoxy）benzene（3 BOCN） and epoxy resin with methyl tetrahydrophthalic anhydride as curing agent. The curing behavior and curing kinetics of the blends were studied by differential scanning calorimetry. The apparent activation energy of the blends with various contents of 3 BOCN was higher than that of the blends without 3 BOCN. A model experiment suggested that there is no obvious reaction between phthalonitrile and epoxy. The thermal and mechanical properties of the polymer blends were evaluated. The polymer blends exhibit high storage modulus and char yield compared with the neat epoxy. The polymer blends show ductile fracture morphology by scanning electron microscopy（SEM） images.展开更多
As the important matrix material,epoxy resin has been widely used in the composites for various fields.On account of the poor toughness of epoxy resin limiting their suitability for advanced applications,considerable ...As the important matrix material,epoxy resin has been widely used in the composites for various fields.On account of the poor toughness of epoxy resin limiting their suitability for advanced applications,considerable interests have been conducted to modify the epoxy resin to meet the engineering requirements.In this study,the bio-based polyurethane(PU)modified resin was adopted to modify the pure bisphenol-A epoxy by blending method with various proportions.Aiming to illuminate the curing behavior,mechanical and thermal properties,the blended epoxy systems were characterized by viscosity-time analysis,dynamic mechanical analysis(DMA)at different frequencies and temperatures,mechanical tensile test,thermogravimetric analysis(TGA)and Fourier transform infrared(FT-IR)spectroscopy.The results indicated that the introduction of PU modified epoxy was found to significantly inhibit the viscosity growth rates especially when the content of PU modified epoxy resin is higher than 60%.Notwithstanding the dynamic modulus and T_(g)reduced with the increment of PU modified epoxy,remarkable increment on the elongation at break was found and the flexibility was greatly promoted with the introduction of PU modified epoxy.The proportion of PU modified epoxy in the blends should be put balance considerations to obtain optimal mechanical properties.TGA results and FTIR spectrum demonstrated that the addition of PU modified epoxy did not change the thermal decomposition mechanism and chemical reaction mechanism,but the addition of PU modified epoxy inhibits the curing reaction of epoxy resin by measured and calculated the damping temperature domainT from 35.7℃ to 48.9℃.展开更多
A multi-objective intelligent coordinating optimization strategy based on qualitative and quantitative synthetic model for Pb-Zn sintering blending process was proposed to obtain optimal mixture ratio. The mechanism a...A multi-objective intelligent coordinating optimization strategy based on qualitative and quantitative synthetic model for Pb-Zn sintering blending process was proposed to obtain optimal mixture ratio. The mechanism and neural network quantitative models for predicting compositions and rule models for expert reasoning were constructed based on statistical data and empirical knowledge. An expert reasoning method based on these models were proposed to solve blending optimization problem, including multi-objective optimization for the first blending process and area optimization for the second blending process, and to determine optimal mixture ratio which will meet the requirement of intelligent coordination. The results show that the qualified rates of agglomerate Pb, Zn and S compositions are increased by 7.1%, 6.5% and 6.9%, respectively, and the fluctuation of sintering permeability is reduced by 7.0%, which effectively stabilizes the agglomerate compositions and the permeability.展开更多
The dynamic viscoelastic response of the two-phase polymer blend systems shows the characteristics of the thermorheologically complex materials. In this paper theoretical equations for describing the dynamic viscoelas...The dynamic viscoelastic response of the two-phase polymer blend systems shows the characteristics of the thermorheologically complex materials. In this paper theoretical equations for describing the dynamic viscoelastic response of such polymer blend systems have been established by means of the mechanical modeling technique. The dynamic viscoelastic response of the blend systems at any blend composition can be predicted theoretically by using the equations established, provided that the dynamic viscoelastic response of the two pure components and the mechanical model parameters are known in advance. Thus, we provide an effective method for studying the dynamic mechanical properties and the molecular relaxation characteristics of the two-phase polymer blend systems.展开更多
For two-phase polymer blend systems, the phase inversion will take place as the blendcomposition is changed. In this paper a mechanical model has been proposed to describe themodulus-composition relation in the phase ...For two-phase polymer blend systems, the phase inversion will take place as the blendcomposition is changed. In this paper a mechanical model has been proposed to describe themodulus-composition relation in the phase inversion region. The application of the mechanicalmodel to two polyurethane blend systems has been studied. It was found that the theoreticalprediction for the modulus-composition relation is quite consistent with the experimentalresults. Furthermore, the characteristics of the phase inversion can be determined uniquelyby the parameters involved in the mechanical model.展开更多
The melt rheological behaviors of the PET/E-HDP(for short of Easily Hydrolyzed and Easily Dyed Polyester) blending systems at different blending ratios were investigated by the capillary rheometer. The E-HDP is derive...The melt rheological behaviors of the PET/E-HDP(for short of Easily Hydrolyzed and Easily Dyed Polyester) blending systems at different blending ratios were investigated by the capillary rheometer. The E-HDP is derived from polyethylene terephathalate (PET) modified through copolycondensation with sulfonate moiety, (sodiosulfo) isophthalate (Na-SIP) and iso-phthalic acid(IPA). The results showed that the apparent viscosity and non-Newtonian index of the PET/E-HDP blend system had the non-linearity change with the change of the blend ratio of PET/E-HDP. The anomaly of the viscous flow activation energy change was founded as the mass fraction of E-HDP was about 40% in the blend system,suggesting the presence of reversible crosslinked structure formed by strong polar tangling points and the phase separation owing to poor compatibility between the PET and展开更多
New information and communication technologies(ICT)are being applied in various industries to upgrade the value of the major service items.Moreover,data collection,storage,processing,and security applications have led...New information and communication technologies(ICT)are being applied in various industries to upgrade the value of the major service items.Moreover,data collection,storage,processing,and security applications have led to the creation of an interrelated ICT environment in which one industry can directly influence the other.This is called the“internet of blended environ-ments”(IoBE),as it is an interrelated data environment based on internet-of-things collection activities.In this environment,security incidents may increase as size and interconnectivity of attackable operations grow.Consequently,pre-emptive responses to combined security threats are needed to securely utilize IoBE across industries.For example,the medical industry has more stringent information protection measures than other industries.Consequently,it has become a major target of attackers,as more clinician–patient interactions occur over the internet owing to COVID-19.Therefore,this study aims to acquire security for IoBE while focusing on the medical industry.Among the various types of medical ICT services,this study analyzes dataflow and potential security threats from the e-prescription lifecycle perspective,which is highly utilized,strongly data-centric,and has numerous security issues.Based on our analysis,we propose a secure authentication and data-sharing scheme.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 60978060 and 50602008)the Beijing Municipal Science & Technology Commission (Grant No. Z090803044009001)the Excellent Doctor’s Science and Technology Innovation Foundation of Beijing Jiaotong University of China (Grant No. 141107522)
文摘Organic solar cells based on poly（N-vinylcarbazole） （PVK）： porphyrin： tris （8-hydroxyquinolinato） aluminium （Alq3） blend p-n junction systems have been fabricated in this work. The roles of the different components in the blend system and of the amount of porphyrin have been investigated. The 5, 10, 15, 20-tetraphenylporphyrin （TPP） and 5, 10, 15, 20-tetra（o-chloro）phenylporphyrinato-copper （CuTC1PP） are used in the solar cells. The results show that TPP is better than CuTC1PP in enhancing the performance of PVK：Alq3 solar cells. When the weight ratio of PVK：TPP：Alq3 is 1：1.5：1, the best performance of solar cell is obtained. The open circuit voltage （Voc） is 0.87 V, and the short circuit current （Jsc） is 17.5 μA·cm-2. In the ternary bulk hereojunction system, the device may be regarded as a cascade of three devices of PVK：TPP, TPP：Alq3 and PVK：Alq3. PVK, TPP and Alq3 can improve the hole mobility, light absorption intensity and electron mobility of the ternary bulk hereojunction system, respectively.
基金the support of the research commission of the Catholic University of Lille and its Foundationthe IEMN laboratory for the financial supportsupport from the Materials Research Institute (MRI) and the Institute of Energy and the Environment (IEE) of the Pennsylvania State University。
文摘Embedding a third and/or fourth component into a binary blend active layer of organic photovoltaics (OPVs) is a promising approach to achieve high-performance photovoltaic cells and modules. This multicomponent strategy favors absorption broadening via additional components. Quaternary OPV (QOPV) blends have four components in three possible configurations: (i) a donor and three acceptors, (ii) two donors and two acceptors, or (iii) three donors and an acceptor. Although quaternary systems have only been relatively recently studied compared to other systems in OPVs, leveraging the synergistic effects of the four components leads to record power conversion efficiencies, currently approaching 20%. QOPVs provide ample material choices for compatibility and channels for charge transfer mechanisms, possibly leading to optimized morphology and orientation. Reviewing recent progress in advancing QOPVs is essential for understanding their contribution to the OPV field. The review mainly discusses research progress in QOPVs with a keen interest in their various configurations, semitransparency, and outdoor and indoor applications. It describes the not-well-understood QOPV's general working mechanism. This review explores high-performance QOPVs based on the fourth component's contribution as a donor, acceptor, or dye molecule and beyond in photovoltaic applications. Finally, there is a discussion around QOPV's outlook and projected future research directions in this field. This review intends to provide an overview of the quaternary systems approach to OPVs and inform current and future researchers on investigating the full spectrum of OPVs.
基金made possible by PDRA(Grant No.PDRA1-0117-14109)from the Qatar National Research Fund(a member of Qatar Foundation)
文摘In this research, we report a bulk heterojunction（BHJ） solar cell consisting of a ternary blend system. Poly（3-hexylthiophene） P3 HT is used as a donor and [6,6]-phenyl C61-butyric acid methylester（PCBM） plays the role of acceptor whereas vanadyl 2,9,16,23-tetraphenoxy-29 H, 31H-phthalocyanine（VOPc Ph O） is selected as an ambipolar transport material. The materials are selected and assembled in such a fashion that the generated charge carriers could efficiently be transported rightwards within the blend. The organic BHJ solar cells consist of ITO/PEDOT：PSS/ternary BHJ blend/Al structure. The power conversion efficiencies of the ITO/ PEDOT：PSS/P3HT：PCBM/Al and ITO/PEDOT：PSS/P3HT：PCBM：VOPcPhO/Al solar cells are found to be 2.3% and 3.4%, respectively.
基金financially supported by the Natural Science Foundation of Shandong Province(Nos.ZR2023QA136,ZR2021MA073 and ZR2024QA235)the National Natural Science Foundation of China(No.22173051).
文摘We investigated the phase behavior of diblock copolymer AB/homopolymer C blends in concentrated aqueous solutions using a simulated annealing method.Phase diagrams were constructed as a function of the concentration of all polymers(Φ)and the volume fraction of homopolymer(fC).Rich phase transition sequences were observed,especially reentrant phase transitions,such as lamellae→inverted cylinders→gyroids→lamellae→disorder,for a givenΦwith increasing fC.By analyzing the variations in the average contact numbers between different components and the effective volume fractions of B-domains,we elucidated the mechanisms of the reentrant phase transitions.We found that the strong attraction between B and C leads to the swelling of B-domains upon addition of homopolymer.Concurrently,the solvent preferentially swells the A-domains over the B+C-domains.The competing swelling effects of the solvent and homopolymer on the A-domains and B-domains,respectively,triggered the reentrant phase behavior in the symmetric AB copolymer system upon addition of homopolymer.
基金supported by the Science and Technology Development Plan of Jilin Province(No.YDZJ202403009CGZH)Engineering Research Center of Coalbased Ecological Carbon Sequestration Technology of the Ministry of Education(No.MJST2025-1)+2 种基金Chinese Academy of Sciences(Changchun Branch)(No.2024SYHZ0038)Development and Reform Commission of Jilin Province of China(No.2024C019-5)Science and Technology Bureau of Changchun City of China(No.23SH08)。
文摘A polylactide(PLA)blend with simultaneous enhancement of strength,toughness,and heat resistance was successfully achieved by adding biodegradable poly(propylene carbonate)(PPC)and uniaxial pre-stretching.The effects of the PPC content(0 wt%-50 wt%)on the phase morphology and performance of the blends before and after pre-stretching were systematically investigated.Blending PPC initially reduced the strength,modulus,and heat resistance,but pre-stretching significantly enhanced these properties.In blends containing≤30 wt%PPC,where PPC formed a well-dispersed island-like phase within the PLA matrix,pre-stretching simultaneously enhanced strength,toughness,and heat resistance.The optimized pre-stretched 70/30 PLA/PPC(ps-70/30)blend achieved exceptional performance:tensile strength increased from 66.9MPa to 84.5 MPa,elongation at break dramatically improved from 6.8%to 115.1%,impact strength reached 55.1 k J/m^(2)(far exceeding neat PLA's 3.5 k J/m^(2)),and Vicat softening temperature(VST)increased by 60.6%to 101.8℃.Notably,the ps-70/30 blend retained excellent mechanical properties even after six months of aging.These improvements were attributed to the synergistic effects of the PPC incorporation and prestretching.PPC not only promoted the high orientation of the PLA molecular chains but also facilitated the formation of a stable crystalline phase during pre-stretching,thereby enhancing both the mechanical properties and heat resistance.However,when the PPC content exceeded 30wt%,phase inversion occurred,resulting in a continuous amorphous PPC phase that degraded the overall performance.This study demonstrated that a combination of controlled PPC incorporation and pre-stretching can effectively overcome PLA's brittleness of PLA while improving its heat resistance,offering a promising strategy for developing high-performance,fully biodegradable PLA materials suitable for industrial applications.
基金Funded by the National Natural Science Foundation of China(No.52278446)。
文摘To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt by physical property index,microscopic morphology,rheological testing,and infrared spectroscopy on multiple scales.The results show that the best preparation process for TB-modified asphalt is stirring at 260℃ for 4 h at 400 rpm,which significantly reduces the modification time of the asphalt.From a physical property viewpoint,the TB composite-modified asphalt sample with 5% styrene-butadiene-styrene(SBS)+1% aromatics+0.1% sulfur exhibits high-comprehensive,high-and low-temperature properties.More-over,its crosslinked mesh structure comprises black rubber particles uniformly interwoven in the middle,which further enhances the performance of the asphalt and results in an excellent performance formulation.In addition,the sample with 5%SBS content has a higher G*value and smaller δ value than that with 3%SBS content,indicating that its high-temperature resistance is improved.The effect of adding 3%SBS content on the viscoelastic ratio is,to some extent,less than that caused by 20% rubber powder.
基金financially supported by Ministry of Science and Higher Education of the Russian Federation.
文摘A new principle for producing fire-resistant polymer materials with increased deformation properties using a flame retardant not as a heterogeneous additive,but as a thermoplastic flame retardant in a hybrid polymer mixture with a polyhydrocarbon is considered.Hybrid polymer blends of low-molecular ammonium polyphosphate(APP)with an ethylene-vinyl acetate copolymer(EVA)with an APP content of 80 wt%with enhanced deformation properties were obtained by extrusion mixing at various temperatures in the range from 200°C to 250°C.A chemical scheme for the transformations of the components during the formation of the composite is proposed.X-ray diffraction analysis showed the formation of new crystalline structures of APP.The phase structure of the systems corresponding to the model of a dispersed-filled composite in which EVA plays the role of a matrix,determining the deformation of the mixture,and the filler is ammonium polyphosphate,was studied by scanning electron microscopy(SEM).The method of FTIR microscopy showed chemical interactions between EVA and APP with the formation of amide groups.The conditions for obtaining compositions characterized by heat resistance of 210°C,oxygen index of 55 and ultimate elongation at drawing of 213%were established.
基金financially supported by the National Natural Science Foundation of China(Nos.52373070,52273071 and U25A20255)the Special Support Plan for High-Level Talents in Zhejiang Province(No.2022R51008)the HZNU scientific research and innovation team project(No.TD2025004).
文摘Rubber-toughened thermoplastic materials have become ubiquitous in modern society owing to their lightweight nature and desirable combination of advantageous performances.Despite the ever-increasing demand,the development of polymer alloys that are lightweight,high-strength,and high-toughness remains an ongoing challenge.Inspired by the unique“salami”microstructure from commercial acrylonitrile butadiene styrene copolymer(ABS)and high-impact polystyrene(HIPS),a facile approach was developed to overcome the trade-off between enhancing the toughness and rigidity of fully polymer-based alloys by virtue of elastomeric salami particles.This strategy entails pre-grafting rigid poly(lactic acid)(PLLA)chains with glycidyl methacrylate-grafted octene ethylene copolymer(POE-g-GMA)using complementary reactive groups.It can be envisaged that the PLLA grafts featuring strong incompatibility with polypropylene(PP)remain fixed in elastomer phase upon the subsequent melt compounding,facilitating the in situ formation of“hard core(PLLA)-soft shell(polyolefin elastomer,POE)”particles in polypropylene(PP)matrix.The all-polymer alloys containing elastomeric salami particles demonstrated unprecedented performance combinations,including upper notched impact strengths(56.8 kJ/m2),even higher tensile strength(36.8 MPa),and Young’s modulus(0.93 GPa)than that of the PP matrix.Furthermore,these materials are lightweight without the incorporation of reinforcing nano-fillers,which is competitive with industrial engineering plastics.It is highly anticipated that this universal and highly efficient protocol will be appropriate for arbitrary rubber toughened/reinforced systems,offering a paradigm in the design of advanced all-polymer alloys.
基金supported by the National Natural Science Foundation of China[grant numbers 12071329,12471246].
文摘In mixture experiments,the observed response is determined by the relative proportions of the components,consequently rendering the experimental region a simplex.This paper focuses primarily on the optimal designs of mixture experiments that involve process variables.Prior research has extensively delved into optimal orthogonal block designs for some classic mixture models with process variables.Based on the framework of general blending models,this paper proposes a class of symmetric linear mixture models,which can be regarded as a generalization of many existing ones.Under the orthogonal blocking conditions,orthogonal block designs are devised through Latin squares in the presence of process variables.TheD-,A-,and E-optimality criteria are utilized to obtain optimal designs at the boundary of the simplex in the case of 3 components.As the values of the exponents change,numerically derived optimal design points are presented to illustrate the pattern of their variations,and to verify the consistency of the results with previous research on some specific symmetric general blending models.
基金financially supported by the National Natural Science Foundation of China(Nos.22341304,22303100 and 12205270)the National Key R&D Program of China(Nos.2023YFA1008800 and 2020YFA0713601)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC0180303)。
文摘The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.
基金supported by the National Natural Science Foundation of China (Grant No. 91437113)the Special Fund for Meteorological Scientific Research in the Public Interest (Grant Nos. GYHY201506007 and GYHY201006015)+1 种基金the National 973 Program of China (Grant Nos. 2012CB417204 and 2012CB955200)the Scientific Research & Innovation Projects for Academic Degree Students of Ordinary Universities of Jiangsu (Grant No. KYLX 0827)
文摘An initial conditions （ICs） perturbation method was developed with the aim to improve an operational regional ensemble prediction system （REPS）. Three issues were identified and investigated： （1） the impacts of perturbation scale on the ensemble spread and forecast skill of the REPS; （2） the scale characteristic of the IC perturbations of the REPS; and （3） whether the REPS＇s skill could be improved by adding large-scale information to the IC perturbations. Numerical experiments were conducted to reveal the impact of perturbation scale on the ensemble spread and forecast skill. The scales of IC perturbations from the REPS and an operational global ensemble prediction system （GEPS） were analyzed. A ＂multi-scale blending＂ （MSB） IC perturbation scheme was developed, and the main findings can be summarized as follows： The growth rates of the ensemble spread of the REPS are sensitive to the scale of the IC perturbations; the ensemble forecast skills can benefit from large-scale perturbations; the global ensemble IC perturbations exhibit more power at larger scales, while the regional ensemble IC perturbations contain more power at smaller scales; the MSB method can generate IC perturbations by combining the small-scale component from the REPS and the large-scale component from the GEPS; the energy norm growth of the MSB-generated perturbations can be appropriate at all forecast lead times; and the MSB-based REPS shows higher skill than the original system, as determined by ensemble forecast verification.
文摘Using GIS, GPS and GPRS, a dynamic management system of ore blending in an open pit mine has been designed and developed. A linear program was established in a practical application. The system is very good at automatically drawing up a daily production plan of ore blending and monitors and controls the process of mining production in real time. Experiments under real conditions show that the performance of this system is stable and can satisfy production standards of ore blending in open pit mines.
基金financially supported by the National Natural Science Foundation of China(Nos.51203098 and 51173114)
文摘A series of polymer blends were prepared from 1,3-bis（3,4-dicyanophenoxy）benzene（3 BOCN） and epoxy resin with methyl tetrahydrophthalic anhydride as curing agent. The curing behavior and curing kinetics of the blends were studied by differential scanning calorimetry. The apparent activation energy of the blends with various contents of 3 BOCN was higher than that of the blends without 3 BOCN. A model experiment suggested that there is no obvious reaction between phthalonitrile and epoxy. The thermal and mechanical properties of the polymer blends were evaluated. The polymer blends exhibit high storage modulus and char yield compared with the neat epoxy. The polymer blends show ductile fracture morphology by scanning electron microscopy（SEM） images.
基金The authors acknowledge the financial support of the National Natural Science Foundation of China(No.51908330)the Qilu Young Scholars Program of Shandong University,Natural Science Foundation of Shandong Province(CN)(No.ZR2020ME244),the Fundamental Research Funds of Shandong University(No.2020GN059)the Fundamental Research Funds for the Central Universities,CHD(No.300102210502)and Scientific Research Project of Shandong High-speed Group Co.,Ltd.,(No.SDGS-KJCX-2020-006-08).
文摘As the important matrix material,epoxy resin has been widely used in the composites for various fields.On account of the poor toughness of epoxy resin limiting their suitability for advanced applications,considerable interests have been conducted to modify the epoxy resin to meet the engineering requirements.In this study,the bio-based polyurethane(PU)modified resin was adopted to modify the pure bisphenol-A epoxy by blending method with various proportions.Aiming to illuminate the curing behavior,mechanical and thermal properties,the blended epoxy systems were characterized by viscosity-time analysis,dynamic mechanical analysis(DMA)at different frequencies and temperatures,mechanical tensile test,thermogravimetric analysis(TGA)and Fourier transform infrared(FT-IR)spectroscopy.The results indicated that the introduction of PU modified epoxy was found to significantly inhibit the viscosity growth rates especially when the content of PU modified epoxy resin is higher than 60%.Notwithstanding the dynamic modulus and T_(g)reduced with the increment of PU modified epoxy,remarkable increment on the elongation at break was found and the flexibility was greatly promoted with the introduction of PU modified epoxy.The proportion of PU modified epoxy in the blends should be put balance considerations to obtain optimal mechanical properties.TGA results and FTIR spectrum demonstrated that the addition of PU modified epoxy did not change the thermal decomposition mechanism and chemical reaction mechanism,but the addition of PU modified epoxy inhibits the curing reaction of epoxy resin by measured and calculated the damping temperature domainT from 35.7℃ to 48.9℃.
基金Project(2002CB312203) supported by the National Key Fundamental Research and Development Programof China pro-ject(60574030) supported bythe National Natural Science Foundation of China project(06FD026) supported bythe Natural Science Foun-dation of Hunan Province , China
文摘A multi-objective intelligent coordinating optimization strategy based on qualitative and quantitative synthetic model for Pb-Zn sintering blending process was proposed to obtain optimal mixture ratio. The mechanism and neural network quantitative models for predicting compositions and rule models for expert reasoning were constructed based on statistical data and empirical knowledge. An expert reasoning method based on these models were proposed to solve blending optimization problem, including multi-objective optimization for the first blending process and area optimization for the second blending process, and to determine optimal mixture ratio which will meet the requirement of intelligent coordination. The results show that the qualified rates of agglomerate Pb, Zn and S compositions are increased by 7.1%, 6.5% and 6.9%, respectively, and the fluctuation of sintering permeability is reduced by 7.0%, which effectively stabilizes the agglomerate compositions and the permeability.
基金Project supported by the Natural Science Foundation of Academia Sinica.
文摘The dynamic viscoelastic response of the two-phase polymer blend systems shows the characteristics of the thermorheologically complex materials. In this paper theoretical equations for describing the dynamic viscoelastic response of such polymer blend systems have been established by means of the mechanical modeling technique. The dynamic viscoelastic response of the blend systems at any blend composition can be predicted theoretically by using the equations established, provided that the dynamic viscoelastic response of the two pure components and the mechanical model parameters are known in advance. Thus, we provide an effective method for studying the dynamic mechanical properties and the molecular relaxation characteristics of the two-phase polymer blend systems.
基金Project supported by the National Natural Science Foundation of China.
文摘For two-phase polymer blend systems, the phase inversion will take place as the blendcomposition is changed. In this paper a mechanical model has been proposed to describe themodulus-composition relation in the phase inversion region. The application of the mechanicalmodel to two polyurethane blend systems has been studied. It was found that the theoreticalprediction for the modulus-composition relation is quite consistent with the experimentalresults. Furthermore, the characteristics of the phase inversion can be determined uniquelyby the parameters involved in the mechanical model.
文摘The melt rheological behaviors of the PET/E-HDP(for short of Easily Hydrolyzed and Easily Dyed Polyester) blending systems at different blending ratios were investigated by the capillary rheometer. The E-HDP is derived from polyethylene terephathalate (PET) modified through copolycondensation with sulfonate moiety, (sodiosulfo) isophthalate (Na-SIP) and iso-phthalic acid(IPA). The results showed that the apparent viscosity and non-Newtonian index of the PET/E-HDP blend system had the non-linearity change with the change of the blend ratio of PET/E-HDP. The anomaly of the viscous flow activation energy change was founded as the mass fraction of E-HDP was about 40% in the blend system,suggesting the presence of reversible crosslinked structure formed by strong polar tangling points and the phase separation owing to poor compatibility between the PET and
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT,No.2021R1A2C2011391).
文摘New information and communication technologies(ICT)are being applied in various industries to upgrade the value of the major service items.Moreover,data collection,storage,processing,and security applications have led to the creation of an interrelated ICT environment in which one industry can directly influence the other.This is called the“internet of blended environ-ments”(IoBE),as it is an interrelated data environment based on internet-of-things collection activities.In this environment,security incidents may increase as size and interconnectivity of attackable operations grow.Consequently,pre-emptive responses to combined security threats are needed to securely utilize IoBE across industries.For example,the medical industry has more stringent information protection measures than other industries.Consequently,it has become a major target of attackers,as more clinician–patient interactions occur over the internet owing to COVID-19.Therefore,this study aims to acquire security for IoBE while focusing on the medical industry.Among the various types of medical ICT services,this study analyzes dataflow and potential security threats from the e-prescription lifecycle perspective,which is highly utilized,strongly data-centric,and has numerous security issues.Based on our analysis,we propose a secure authentication and data-sharing scheme.
