In this paper,we study make-or-buy decisions with the consideration of retail-level competition,in which a supplier provides substitutable products to two retailers.One incumbent retailer is capable of producing the p...In this paper,we study make-or-buy decisions with the consideration of retail-level competition,in which a supplier provides substitutable products to two retailers.One incumbent retailer is capable of producing the product in-house and makes the make-or-buy decision,while the rival retailer can only outsource from the supplier.Intuitively,the incumbent will not outsource if the wholesale price is higher than its production cost.However,we illustrate this may not be true when the supplier also supplies the retail rival.In this case,the incumbent may accept a high wholesale price to limit the supplier's incentive to serve the retail rival on particularly favorable terms.Moreover,under certain circumstances,the supplier may charge a wholesale price lower than its production cost to attract orders from the incumbent,which can generate for the supplier and the incumbent a higher total profit than the situation in which the incumbent makes the product in-house.展开更多
This paper considers tripartite pricing issues in a two-echelon supply chain involving duopolistic manufacturers and a single retailer.Firstly,a tripartite competitive model is conducted,in which both a Stackelberg ga...This paper considers tripartite pricing issues in a two-echelon supply chain involving duopolistic manufacturers and a single retailer.Firstly,a tripartite competitive model is conducted,in which both a Stackelberg game and a Bertrand game occur simultaneously.It is shown that the manufacturer who possesses a higher sales quantity gains more profits than the other one.Secondly,a definition of optimal vertical pricing alliance is proposed when cooperation exists between the retailer and some manufacturer.We conduct two-player games when partial cooperation exists among the three participants.It is demonstrated that the total profit of the alliance is higher than the sum profit of the corresponding two participants in the tripartite competition model,and meanwhile the profit of the manufacturer who is not in the alliance suffers a loss.Further,a criterion is given to judge which manufacturer the retailer will choose to cooperate in order to maximize the total increased profits.From the perspective of game theory,we examine the stability of the vertical alliance with considering the dominance of the retailer.Finally,a numerical illustration is designed to examine the judging criteria of which manufacturer is the member of the optimal alliance under different potential market demands.展开更多
A medical image encryption is proposed based on the Fisher-Yates scrambling,filter diffusion and S-box substitution.First,chaotic sequence associated with the plaintext is generated by logistic-sine-cosine system,whic...A medical image encryption is proposed based on the Fisher-Yates scrambling,filter diffusion and S-box substitution.First,chaotic sequence associated with the plaintext is generated by logistic-sine-cosine system,which is used for the scrambling,substitution and diffusion processes.The three-dimensional Fisher-Yates scrambling,S-box substitution and diffusion are employed for the first round of encryption.The chaotic sequence is adopted for secondary encryption to scramble the ciphertext obtained in the first round.Then,three-dimensional filter is applied to diffusion for further useful information hiding.The key to the algorithm is generated by the combination of hash value of plaintext image and the input parameters.It improves resisting ability of plaintext attacks.The security analysis shows that the algorithm is effective and efficient.It can resist common attacks.In addition,the good diffusion effect shows that the scheme can solve the differential attacks encountered in the transmission of medical images and has positive implications for future research.展开更多
Base-catalyzed nucleophilic substitution reactions ofβ-ketonitrile with azodicarboxylates have been developed.A series of disubstituted C—N coupling products were obtained in good to excellent yields under Et_(3)N c...Base-catalyzed nucleophilic substitution reactions ofβ-ketonitrile with azodicarboxylates have been developed.A series of disubstituted C—N coupling products were obtained in good to excellent yields under Et_(3)N catalysis.Monosubstitu-tion C—N bond formation reaction catalyzed by K_(2)CO_(3) also gave novel enol-based target products.This method is simple and mild,with good chemoselectivity,excellent substrate compatibility and tolerance for various functional groups,and achieves gram-scale synthesis.The reaction is a nucleophilic substitution process without the involvement of free radicals.展开更多
Asymmetric allylic C—H functionalization is a valuable and challenging research area. Different from the conventional direct allylic C—H cleavage strategy, transition metal-catalyzed migratory allylic substitution o...Asymmetric allylic C—H functionalization is a valuable and challenging research area. Different from the conventional direct allylic C—H cleavage strategy, transition metal-catalyzed migratory allylic substitution of remote dienes has emerged as a new route to achieve allylic C—H functionalization enantioselectively. This review provides a detailed summary of the development and advance of this strategy, introduces the related mechanistic processes, and discusses the area based on the types of catalysts and products.展开更多
A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones w...A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones with cyclic quaternary centers in moderate to good yields and>19∶1 dr.This catalysis enables the direct construction of two types of carboncyclic skeletons by adjusting the olefin types of 1,3-enyne acetates.When 1,3-enyne acetates bearing a cyclic alkene unit were used,5~6 fused bicarbocyclic products were diastereoselectively synthesized,whereas the reaction of acyclic 1,3-enyne acetates resulted in five-memebered carbocyclic framework.Notably,cyclic ether acetals are commonly used as protecting groups in traditional multistep organic syntheses,and in this reaction,such reagents serve as electrophilic cyclic ether precursors,achieving new uses for old reagents.The current method demonstrates good functional group compatibility,a broad substrate scope and high diastereoselectivity,providing a new synthetic strategy toward functionalized cyclopentenones.展开更多
The feldspar-based microwave dielectric ceramic with low relative permittivity(εr)and excellent mechanical properties has attracted much attention in the fifth-generation wireless communication technology.In this wor...The feldspar-based microwave dielectric ceramic with low relative permittivity(εr)and excellent mechanical properties has attracted much attention in the fifth-generation wireless communication technology.In this work,a series of microwave dielectric ceramic SrAl_(2-x)Ga_(x)Si_(2)O_(8)(0.1≤x≤2.0)was synthesized using the traditional solid-state method.X-ray diffraction pattern indicates that Ga^(3+)can be dissolved into Al^(3+),forming a solid solution.Meanwhile,substitution of Ga^(3+)for Al^(3+)can promote the space group transition from I2/c(0.1≤x≤1.4)to P21/a(1.6≤x≤2.0)with coefficient of thermal expansion(CTE)increasing from 2.9×10^(-6)℃^(-1) to 5.2×10^(-6)℃^(-1).During this substitution,the phase transition can significantly improve the structural symmetry to enhance the dielectric properties and mechanical properties.Rietveld refinement results indicate that Ga^(3+)averagely occupied four Al^(3+)compositions to form solid solution.All ceramics have a dense microstructure and high relative density above 95%.An ultralower of 5.8 was obtained at x=1.6 composition with high quality factor(Q´f)of 50700 GHz and negative temperature coefficients of resonant frequency(tf)of approximately−35×10^(-6)℃^(-1).The densification temperature can be reduced to 940℃by adding 4%(in mass)LiF,resulting in good chemical compatibility with Ag electrode.Meanwhile,negativetf can be tuned to near-zero(+3.7×10^(-6)℃^(-1))by adding CaTiO_(3) ceramic.展开更多
Sustainable integrated inventory management policy focuses on reducing the environmental impact of the manufacturing and transport sector.This study develops an integrated single-manufacturer single-buyer inventory mo...Sustainable integrated inventory management policy focuses on reducing the environmental impact of the manufacturing and transport sector.This study develops an integrated single-manufacturer single-buyer inventory model for substitutable deteriorating items considering transport and industry carbon emissions.This article categorizes carbon emissions into two parts:direct and indirect emissions.We also assume two mutually substitutable items,and substitution is considered on the buyer's side.If one of the items is out of stock,the demand for that item can be partially satisfied by the stock of the other item;else,demand will be lost.The purpose of this study is to minimize the integrated cost of the supply chain with total carbon emissions produced by industry and transport sectors and to determine the optimal number of deliveries,order level and carbon emission quantity.A solution procedure is developed to find the optimal values of the policy.Numerical experiments and sensitivity analyses are presented to demonstrate the proposed model.展开更多
Industrial waste management constitutes a major challenge for sustainable development. This study aims to transform hardened cement waste stored in cement warehouses and in real estate construction sites into paving s...Industrial waste management constitutes a major challenge for sustainable development. This study aims to transform hardened cement waste stored in cement warehouses and in real estate construction sites into paving stones. This innovative solution will contribute to the protection of the environment and the reduction of inert industrial waste. To do this, paving stones based on hardened cement have been developed and characterized. The raw materials were subjected to physical and mechanical characterization tests. The hardened cement aggregates previously crushed with the 5/15 granular class were used as substitutes to replace the natural 5/15 aggregates in the hardened paving stones at contents ranging from 0 to 100%. The mechanical characterization results on the raw material showed that the hardened cement aggregate is made from lightweight aggregates. On the prepared mortar, in the fresh state, the Abrams cone slump test showed an increase in the quantity of waste water with the increase in the content of hardened cement aggregate. In the hardened state, physical (porosity, absorption and dry density) and mechanical (compression, splitting traction, 3-point bending traction and wear) characterization tests were carried out at periods of 7, 14 and 28 days of maturation in water on the cobblestones. These results show that the substitution of natural aggregates by hardened cement aggregates in increasingly large proportions leads to an improvement in compressive, flexural, splitting and wear resistance. In addition, the incorporation of hardened cement aggregate considerably slows down the mechanical degradation of the paving stones. They can, therefore, be used in road and interior or exterior floor coverings.展开更多
Bioprinting is a widely used technique for creating three-dimensional,complex,and heterogeneous artificial tissue constructs that are biologically and biophysically similar to natural tissues.The skin is composed of s...Bioprinting is a widely used technique for creating three-dimensional,complex,and heterogeneous artificial tissue constructs that are biologically and biophysically similar to natural tissues.The skin is composed of several layers including the epidermis,basement membrane(BM),and dermis.However,the unique undulating structure of basement membranes(i.e.rete ridges)and the function of BM have not been extensively studied in the fabrication of engineered skin substitutes.In this study,a novel engineered skin substitute incorporating an artificially designed rete ridge(i.e.mogul-shape)was developed using bioprinting and bioinks prepared using collagen and fibrinogen.To mimic the structure of the rete ridges of skin tissue,we developed a modified bioprinting technique,controlling rheological property of bioink to create a mogul-shaped layer.In vitro cellular activities,including the expression of specific genes(those encoding vimentin,laminin-5,collagen IV,and cytokeratins),demonstrated that the engineered skin substitute exhibited more potent cellular responses than the normally bioprinted control owing to the favorable biophysical BM structure and the bioink microenvironment.Additionally,the feasibility of utilizing the bioprinted skin-structure was evaluated in a mouse model,and in vivo results demonstrated that the bioprinted skin substitutes effectively promoted wound healing capabilities.Based on these results,we suggest that bioprinted skin tissues and the bioprinting technique for mimicking rete ridges can be used not only as potential lab-chip models for testing cosmetic materials and drugs,but also as complex physiological models for understanding human skin.展开更多
Metal oxides as support for constructing precious metal single-atom catalysts hold great promise for a wide range of industrial applications,but achieving a high-loading of thermally stable metal single atoms on such ...Metal oxides as support for constructing precious metal single-atom catalysts hold great promise for a wide range of industrial applications,but achieving a high-loading of thermally stable metal single atoms on such supports has been challenging.Herein,we report an innovative strategy for the fabrication of high-density single-atoms(Rh,Ru,Pd)catalysts on CaAl-layered double hydroxides(CaAl-LDH)via isomorphous substitution.The Rh species have occupied Ca^(2+)vacancies within CaAl-LDH laminate by ion-exchange,facilitating a substantial loading of isolated Rh single-atoms.Such catalysts displayed superior performance in the selective hydrogenation to quinoline,pivotal for liquid organic hydrogen storage,and the universality for the hydrogenation of N-heterocyclic aromatic hydrocarbons was also verified.Combining the experimental results and density functional theory calculations,the pathway of quinoline hydrogenation over Rh1CaAl-LDH was proposed.This synthetic strategy marks a significant advancement in the field of single-atom catalysts,expanding their horizons in green chemical processes.展开更多
Alloy engineering,with its ability to tune the electronic band structure,is regarded as an effective method for adjusting the electronic and optoelectronic properties of two-dimensional(2D)semiconductors.However,synth...Alloy engineering,with its ability to tune the electronic band structure,is regarded as an effective method for adjusting the electronic and optoelectronic properties of two-dimensional(2D)semiconductors.However,synthesizing metal-site substitution alloys remains challenging due to the low reactivity of metal precursors and the tendency for spatial phase separation during high-temperature growth.Here,we report the preparation of a high-quality metal-site substitution alloy,Zn_(0.167)Sn_(0.833)S_(2),via the chemical vapor transport method,which exhibits excellent photoresponsivity and enhanced electrical transport properties.Comprehensive characterization techniques,including Raman spectroscopy,x-ray photoelectron spectroscopy(XPS),and electron microscopy,unambiguously confirm the uniform Zn substitution in the as-prepared Zn_(0.167)Sn_(0.833)S_(2) alloy.Furthermore,the photodetector based on the Zn_(0.167)Sn_(0.833)S_(2) alloy demonstrated a high on/off ratio of 51 under white light,a wide spectral response range from 350 nm to 900 nm,and a broad dynamic power range of 80 dB under 638-nm illumination.In terms of transport properties,field-effect transistors(FETs)based on Zn_(0.167)Sn_(0.833)S_(2) achieved a carrier mobility of 6.5 cm^(2)·V^(-1)·s^(-1),which is six times higher than that of SnS_(2).This alloy semiconductor showcases significantly enhanced electronic and optoelectronic properties,offering great potential for the development of high-resolution photodetection technologies.展开更多
To advance the application of layered oxide cathodes in fast-charging sodium-ion batteries,it is crucial to not only suppress irreversible phase transitions but also improve the rate capability of cathode materials an...To advance the application of layered oxide cathodes in fast-charging sodium-ion batteries,it is crucial to not only suppress irreversible phase transitions but also improve the rate capability of cathode materials and optimize Na^(+)diffusion kinetics to ensure high capacity output at various charge-discharge rates.In this research,the targeted F-substitution with a heavy ratio in oxygen anion layer optimizes the Na^(+)diffusion path and electronic conductivity of the material,thereby decreasing the Na^(+)diffusion barrier and imparting high-rate performance.At a 20 C rate,the cathode achieves a capacity of over 80 mAh g^(-1)with stable cycling performance.Additionally,the dual rivet effect between the transition metal layer and oxygen layer prevents significant phase transitions during charge/discharge within the 2-4.2 V range for the modified cathode.As a result,the F-substituted oxygen anion layer improved Na^(+)diffusion,electronic conductivity,and crystal plane structure stability,which led to the development of a highperformance,fast-charging sodium-ion battery(SIB),opening new avenues for commercial applications.展开更多
Grain size is a crucial factor influencing both rice yield and appearance quality.In this study,we identified GL6.1 as a gene associated with rice grain size by map-based cloning.The GL6.1 encodes a protein with CC-NB...Grain size is a crucial factor influencing both rice yield and appearance quality.In this study,we identified GL6.1 as a gene associated with rice grain size by map-based cloning.The GL6.1 encodes a protein with CC-NB-LRR domain,a structural motif related to rice disease resistance.Genetic transformation experiments and the construction of gene pyramiding lines indicate that GL6.1 functions as a negative regulatory factor for rice grain length.By the analysis of SSSLs with diverse donor parents,a total of 11 single nucleotide polymorphisms(SNPs)are identified that are closely associated with the phenotype variations.A yeast one-hybrid library screening revealed that GL6.1 interacts with OsWRKY53,a transcription factor associated with rice disease resistance.Furthermore,RNA-seq assay also revealed the involvement of pathways associated with disease resistance,hinting at a multifaceted role for GL6.1 in both yield and stress tolerance traits in rice.These results indicate that the cloning and in-depth studies of GL6.1 would provide valuable insights into the interplay among high yield,superior quality,and stress tolerance,which are critical goals for rice breeding.展开更多
Understanding the molecular relevance of metabolic rate(MR)is crucial for unveiling the mechanisms driving the evolution of animals.In this study,we investigated the association between mitochondrial DNA characteristi...Understanding the molecular relevance of metabolic rate(MR)is crucial for unveiling the mechanisms driving the evolution of animals.In this study,we investigated the association between mitochondrial DNA characteristics and both resting and maximal MRs in conjunction with life-history traits among 139 species of teleost fish,We gathered fish MR data from various sources and procured sequences of 13 mitochondrial protein-encoding genes.We calculated the absolute substitution rate for entire nucleotide sequences and 4-fold degenerate sites of each gene,along with encoding amino acid sequences.Using the phylogenetic comparative method,we then explored the associations between MR and mitochondrial DNA absolute substitution rate.Additionally,we screened MR-associated single nucleotide variants in mitochondrial DNA.The findings indicate no positive correlation between MRs and any substitution rate values of both combined sequences and individual mitochondrial protein-coding genes,refuting the MR hypothesis.Instead,both maximum body size and longevity correlated negatively with molecular substitution rates,suggesting their influences on both mutation and fixation within mitochondrial genes in fish.Results also revealed significant correlations between base variation at ATP6_169 and both resting MR and maximum MR,identifying the unique ATP6_169G in Scombridae fish,which results in an extremely low isoelectric point(pl)value of the ATP6 protein.Considering its functional significance,the ATP6_169G in Scombridae fish might link to their lifestyle characterized by fast locomotion and high metabolic demands alongside a slower molecular evolutionary rate.展开更多
The relationship between ecosystem services(ES)and human well-being(HWB)is fundamental to the science and practice of sustainability.However,studies have shown conflicting results,which has been attributed to the infl...The relationship between ecosystem services(ES)and human well-being(HWB)is fundamental to the science and practice of sustainability.However,studies have shown conflicting results,which has been attributed to the influences of indicators,contexts,and scales.Yet,another potential factor,which has been overlooked,may be the mixed use of spatial and temporal approaches.Using twelve ES and seven well-being indicators and multiple statistical methods,we quantified and compared the spatial and temporal ES–HWB relationships for Inner Mongolia,China.The spatial and temporal relationships differed in both correlation direction and strength.Most relationships of economic and employment-related indicators with food provisioning and supporting services were temporally positive but spatially nonsignificant or negative.Some relationships of economic and employmentrelated indicators with water retention,sandstorm prevention,and wind erosion were temporally negative but spatially complex.However,the spatial and temporal ES–HWB relationships could also be similar in some cases.We conclude that although both the spatial and temporal approaches have merits,space generally cannot substitute for time in the study of ES–HWB relationship.Our study helps reconcile the seemingly conflicting findings in the literature,and suggests that future studies should explicitly distinguish between the spatial and temporal ES–HWB relationships.展开更多
Donor-acceptor(D-A)compounds are particularly important in optoelectronic and biological applications.However,they are normally synthesized in the presence of transition metal catalysts.Herein,we report a metal-free m...Donor-acceptor(D-A)compounds are particularly important in optoelectronic and biological applications.However,they are normally synthesized in the presence of transition metal catalysts.Herein,we report a metal-free method by a complexmediated nucleophilic aromatic substitution of aryl nitriles with amines.The method can lead to rich D-A type aggregation-induced emission luminogens(AIEgens)with tunable properties.They emit from deep-blue to yellow-green and possess high photoluminescence quantum yields up to 70.5%in the aggregate state.Interestingly,the suppression of intramolecular flapping is proved to play an indispensable role in the AIE behavior,which is different from the mechanism met in other AIEgens.Moreover,the biocompatible AIEgens possess specific staining of lipid droplets in HeLa cells and the superiority of identifying fatty liver over traditional Oil Red O staining is exhibited.展开更多
A series of CoS_(2-x)Se_(x)(x=0.05,0.1,0.2,0.3,and 2)composite catalysts were synthesized on carbon fiber paper via the hydrothermal method with Se doping.By precisely controlling the reaction temperature and Se dopin...A series of CoS_(2-x)Se_(x)(x=0.05,0.1,0.2,0.3,and 2)composite catalysts were synthesized on carbon fiber paper via the hydrothermal method with Se doping.By precisely controlling the reaction temperature and Se doping level,a hollow spherical catalyst structure composed of CoSSe was successfully synthesized,which exhibited exceptional activity for hydrogen evolution in acidic solutions.The influences of Se doping on the microstructure and catalytic mechanism of hydrogen evolution reaction(HER)of these composites were systematically investigated.The experimental results reveal that the hollow spherical sample displays an overpotential value of 143 mV along with a Tafel slope value of 69.8 mV·dec^(-1)at a current density of 10 mA·cm^(-2)in an acid aqueous solution.Furthermore,it demonstrates remarkable cycling stability after undergoing 3000 cycles.The comprehensive analysis indicates that Se doping optimizes the electronic structure and enhances conductivity,meanwhile the unique hollow spherical architecture increases active sites for HER and significantly improves overall electrocatalytic performance.展开更多
P3-type manganese-iron-based cathodes with high specific capacity and abundant resource have attracted considerable attention for sodium-ion batteries.However,the long-term cycle stability of P3-type cathodes is still...P3-type manganese-iron-based cathodes with high specific capacity and abundant resource have attracted considerable attention for sodium-ion batteries.However,the long-term cycle stability of P3-type cathodes is still not satisfactory.In this work,we design a new quaternary manganese-iron-based cathode material(P3-Na_(0.54)Mn_(0.64)Fe_(_(0.1)6)Mg_(0.1)Cu_(0.1)O_(2))by Cu substitution.The strong covalent Cu-O bonds improve the structural stability and the reversibility of O redox during charge and discharge processes.Cu substitution also mitigates the structure change with less unit cell volume variation,and improves the Na-ion transport kinetics effectively.As a result,NMFMC delivers much improved cycling stability and rate capability compared with NMFM.It reveals that the charge compensation of NMFMC is mainly contributed by Mn^(3+/4+),Fe^(3+/3.5+)and O_(2-/-)during the charge and discharge processes,and Cu substitution can also enhance the activity and reversibility of Fe redox.This strategy provides a new pathway toward improving the stability and O redox reversibility of P3-type cathode materials for sodium-ion batteries.展开更多
Halide electrolytes,renowned for their excellent electrochemical stability and wide voltage window,exhibit significant potential in the development of high energy density solid-state batteries featuring high voltage c...Halide electrolytes,renowned for their excellent electrochemical stability and wide voltage window,exhibit significant potential in the development of high energy density solid-state batteries featuring high voltage cathode materials.In this study,we present the development and synthesis of a 0.6Li_(2)S-ZrCl_(4)solid electrolyte,demonstrating an ion conductivity of 1.9×10^(–3)S/cm at 25°C.Under a pressure of 500 MPa,the relative density of the electrolyte can reach 97.37%,showcasing its commendable compressibility.0.6Li_(2)S-ZrCl_(4)served as the electrolyte,and we assembled batteries utilizing a LiCoO_(2)(LCO)positive electrode,Li_(9.54)Si_(1.74)P_(1.44)S_(11.7)Cl_(0.3)(LSPSCl)coating,and Li-In negative electrode for laboratory testing.At 25°C,this all-solid-state battery demonstrated an impressive discharge capacity retention rate of86.99%(with a final discharge specific capacity of 110.5 m Ah/g)after 250 cycles at 24 m A/g and 100 MPa stack pressure.Upon substituting the positive electrode material with LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811)and assembling an all-solid-state battery,it demonstrated a discharge capacity retention rate of 74.17%after200 cycles at 3.6 m A/g and 100 MPa stack pressure in an environment at 25°C(with a final discharge specific capacity of 103.3 m A/g).Our findings hold significant implications for the design of novel superionic conductors,thereby contributing to the advancement of all-solid-state battery technology.展开更多
基金National Natural Science Foundation of China 71831007,71571079,71571160Social Science Foundation in Zhejiang Province 13ZJQN041YBby the Fundamental Research Funds for the Central Universities,No.2019kfyXMBZ046.
文摘In this paper,we study make-or-buy decisions with the consideration of retail-level competition,in which a supplier provides substitutable products to two retailers.One incumbent retailer is capable of producing the product in-house and makes the make-or-buy decision,while the rival retailer can only outsource from the supplier.Intuitively,the incumbent will not outsource if the wholesale price is higher than its production cost.However,we illustrate this may not be true when the supplier also supplies the retail rival.In this case,the incumbent may accept a high wholesale price to limit the supplier's incentive to serve the retail rival on particularly favorable terms.Moreover,under certain circumstances,the supplier may charge a wholesale price lower than its production cost to attract orders from the incumbent,which can generate for the supplier and the incumbent a higher total profit than the situation in which the incumbent makes the product in-house.
文摘This paper considers tripartite pricing issues in a two-echelon supply chain involving duopolistic manufacturers and a single retailer.Firstly,a tripartite competitive model is conducted,in which both a Stackelberg game and a Bertrand game occur simultaneously.It is shown that the manufacturer who possesses a higher sales quantity gains more profits than the other one.Secondly,a definition of optimal vertical pricing alliance is proposed when cooperation exists between the retailer and some manufacturer.We conduct two-player games when partial cooperation exists among the three participants.It is demonstrated that the total profit of the alliance is higher than the sum profit of the corresponding two participants in the tripartite competition model,and meanwhile the profit of the manufacturer who is not in the alliance suffers a loss.Further,a criterion is given to judge which manufacturer the retailer will choose to cooperate in order to maximize the total increased profits.From the perspective of game theory,we examine the stability of the vertical alliance with considering the dominance of the retailer.Finally,a numerical illustration is designed to examine the judging criteria of which manufacturer is the member of the optimal alliance under different potential market demands.
文摘A medical image encryption is proposed based on the Fisher-Yates scrambling,filter diffusion and S-box substitution.First,chaotic sequence associated with the plaintext is generated by logistic-sine-cosine system,which is used for the scrambling,substitution and diffusion processes.The three-dimensional Fisher-Yates scrambling,S-box substitution and diffusion are employed for the first round of encryption.The chaotic sequence is adopted for secondary encryption to scramble the ciphertext obtained in the first round.Then,three-dimensional filter is applied to diffusion for further useful information hiding.The key to the algorithm is generated by the combination of hash value of plaintext image and the input parameters.It improves resisting ability of plaintext attacks.The security analysis shows that the algorithm is effective and efficient.It can resist common attacks.In addition,the good diffusion effect shows that the scheme can solve the differential attacks encountered in the transmission of medical images and has positive implications for future research.
文摘Base-catalyzed nucleophilic substitution reactions ofβ-ketonitrile with azodicarboxylates have been developed.A series of disubstituted C—N coupling products were obtained in good to excellent yields under Et_(3)N catalysis.Monosubstitu-tion C—N bond formation reaction catalyzed by K_(2)CO_(3) also gave novel enol-based target products.This method is simple and mild,with good chemoselectivity,excellent substrate compatibility and tolerance for various functional groups,and achieves gram-scale synthesis.The reaction is a nucleophilic substitution process without the involvement of free radicals.
文摘Asymmetric allylic C—H functionalization is a valuable and challenging research area. Different from the conventional direct allylic C—H cleavage strategy, transition metal-catalyzed migratory allylic substitution of remote dienes has emerged as a new route to achieve allylic C—H functionalization enantioselectively. This review provides a detailed summary of the development and advance of this strategy, introduces the related mechanistic processes, and discusses the area based on the types of catalysts and products.
文摘A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones with cyclic quaternary centers in moderate to good yields and>19∶1 dr.This catalysis enables the direct construction of two types of carboncyclic skeletons by adjusting the olefin types of 1,3-enyne acetates.When 1,3-enyne acetates bearing a cyclic alkene unit were used,5~6 fused bicarbocyclic products were diastereoselectively synthesized,whereas the reaction of acyclic 1,3-enyne acetates resulted in five-memebered carbocyclic framework.Notably,cyclic ether acetals are commonly used as protecting groups in traditional multistep organic syntheses,and in this reaction,such reagents serve as electrophilic cyclic ether precursors,achieving new uses for old reagents.The current method demonstrates good functional group compatibility,a broad substrate scope and high diastereoselectivity,providing a new synthetic strategy toward functionalized cyclopentenones.
基金National Natural Science Foundation of China (52302140)Major Scientific and Technological Innovation Project of Wenzhou (ZG2023040, ZG2023042)Joint Funds of the National Natural Science Foundation of China Key Program (U21B2068)。
文摘The feldspar-based microwave dielectric ceramic with low relative permittivity(εr)and excellent mechanical properties has attracted much attention in the fifth-generation wireless communication technology.In this work,a series of microwave dielectric ceramic SrAl_(2-x)Ga_(x)Si_(2)O_(8)(0.1≤x≤2.0)was synthesized using the traditional solid-state method.X-ray diffraction pattern indicates that Ga^(3+)can be dissolved into Al^(3+),forming a solid solution.Meanwhile,substitution of Ga^(3+)for Al^(3+)can promote the space group transition from I2/c(0.1≤x≤1.4)to P21/a(1.6≤x≤2.0)with coefficient of thermal expansion(CTE)increasing from 2.9×10^(-6)℃^(-1) to 5.2×10^(-6)℃^(-1).During this substitution,the phase transition can significantly improve the structural symmetry to enhance the dielectric properties and mechanical properties.Rietveld refinement results indicate that Ga^(3+)averagely occupied four Al^(3+)compositions to form solid solution.All ceramics have a dense microstructure and high relative density above 95%.An ultralower of 5.8 was obtained at x=1.6 composition with high quality factor(Q´f)of 50700 GHz and negative temperature coefficients of resonant frequency(tf)of approximately−35×10^(-6)℃^(-1).The densification temperature can be reduced to 940℃by adding 4%(in mass)LiF,resulting in good chemical compatibility with Ag electrode.Meanwhile,negativetf can be tuned to near-zero(+3.7×10^(-6)℃^(-1))by adding CaTiO_(3) ceramic.
文摘Sustainable integrated inventory management policy focuses on reducing the environmental impact of the manufacturing and transport sector.This study develops an integrated single-manufacturer single-buyer inventory model for substitutable deteriorating items considering transport and industry carbon emissions.This article categorizes carbon emissions into two parts:direct and indirect emissions.We also assume two mutually substitutable items,and substitution is considered on the buyer's side.If one of the items is out of stock,the demand for that item can be partially satisfied by the stock of the other item;else,demand will be lost.The purpose of this study is to minimize the integrated cost of the supply chain with total carbon emissions produced by industry and transport sectors and to determine the optimal number of deliveries,order level and carbon emission quantity.A solution procedure is developed to find the optimal values of the policy.Numerical experiments and sensitivity analyses are presented to demonstrate the proposed model.
文摘Industrial waste management constitutes a major challenge for sustainable development. This study aims to transform hardened cement waste stored in cement warehouses and in real estate construction sites into paving stones. This innovative solution will contribute to the protection of the environment and the reduction of inert industrial waste. To do this, paving stones based on hardened cement have been developed and characterized. The raw materials were subjected to physical and mechanical characterization tests. The hardened cement aggregates previously crushed with the 5/15 granular class were used as substitutes to replace the natural 5/15 aggregates in the hardened paving stones at contents ranging from 0 to 100%. The mechanical characterization results on the raw material showed that the hardened cement aggregate is made from lightweight aggregates. On the prepared mortar, in the fresh state, the Abrams cone slump test showed an increase in the quantity of waste water with the increase in the content of hardened cement aggregate. In the hardened state, physical (porosity, absorption and dry density) and mechanical (compression, splitting traction, 3-point bending traction and wear) characterization tests were carried out at periods of 7, 14 and 28 days of maturation in water on the cobblestones. These results show that the substitution of natural aggregates by hardened cement aggregates in increasingly large proportions leads to an improvement in compressive, flexural, splitting and wear resistance. In addition, the incorporation of hardened cement aggregate considerably slows down the mechanical degradation of the paving stones. They can, therefore, be used in road and interior or exterior floor coverings.
基金supported by the‘Korea National Institute of Health’(KNIH)research project(Project No.2022ER130502)the National Research Foundation of Korea(NRF)Grant funded by the Korea Government(MSIT)(No.2021R1A2C20060331222182102840102)。
文摘Bioprinting is a widely used technique for creating three-dimensional,complex,and heterogeneous artificial tissue constructs that are biologically and biophysically similar to natural tissues.The skin is composed of several layers including the epidermis,basement membrane(BM),and dermis.However,the unique undulating structure of basement membranes(i.e.rete ridges)and the function of BM have not been extensively studied in the fabrication of engineered skin substitutes.In this study,a novel engineered skin substitute incorporating an artificially designed rete ridge(i.e.mogul-shape)was developed using bioprinting and bioinks prepared using collagen and fibrinogen.To mimic the structure of the rete ridges of skin tissue,we developed a modified bioprinting technique,controlling rheological property of bioink to create a mogul-shaped layer.In vitro cellular activities,including the expression of specific genes(those encoding vimentin,laminin-5,collagen IV,and cytokeratins),demonstrated that the engineered skin substitute exhibited more potent cellular responses than the normally bioprinted control owing to the favorable biophysical BM structure and the bioink microenvironment.Additionally,the feasibility of utilizing the bioprinted skin-structure was evaluated in a mouse model,and in vivo results demonstrated that the bioprinted skin substitutes effectively promoted wound healing capabilities.Based on these results,we suggest that bioprinted skin tissues and the bioprinting technique for mimicking rete ridges can be used not only as potential lab-chip models for testing cosmetic materials and drugs,but also as complex physiological models for understanding human skin.
文摘Metal oxides as support for constructing precious metal single-atom catalysts hold great promise for a wide range of industrial applications,but achieving a high-loading of thermally stable metal single atoms on such supports has been challenging.Herein,we report an innovative strategy for the fabrication of high-density single-atoms(Rh,Ru,Pd)catalysts on CaAl-layered double hydroxides(CaAl-LDH)via isomorphous substitution.The Rh species have occupied Ca^(2+)vacancies within CaAl-LDH laminate by ion-exchange,facilitating a substantial loading of isolated Rh single-atoms.Such catalysts displayed superior performance in the selective hydrogenation to quinoline,pivotal for liquid organic hydrogen storage,and the universality for the hydrogenation of N-heterocyclic aromatic hydrocarbons was also verified.Combining the experimental results and density functional theory calculations,the pathway of quinoline hydrogenation over Rh1CaAl-LDH was proposed.This synthetic strategy marks a significant advancement in the field of single-atom catalysts,expanding their horizons in green chemical processes.
基金supported by the Beijing Natural Science Foundation(Grant No.Z220005)the National Key Research and Development Program of China(Grant Nos.2022YFB3606902 and 2022YFA1405600)+1 种基金the National Natural Science Foundation of China(Grant No.12274456)the Opening Project of the Laboratory of Microelectronic Devices&Integrated Technology,Chinese Academy of Sciences(CAS),Institute of Microelectronics,Chinese Academy of Sciences.
文摘Alloy engineering,with its ability to tune the electronic band structure,is regarded as an effective method for adjusting the electronic and optoelectronic properties of two-dimensional(2D)semiconductors.However,synthesizing metal-site substitution alloys remains challenging due to the low reactivity of metal precursors and the tendency for spatial phase separation during high-temperature growth.Here,we report the preparation of a high-quality metal-site substitution alloy,Zn_(0.167)Sn_(0.833)S_(2),via the chemical vapor transport method,which exhibits excellent photoresponsivity and enhanced electrical transport properties.Comprehensive characterization techniques,including Raman spectroscopy,x-ray photoelectron spectroscopy(XPS),and electron microscopy,unambiguously confirm the uniform Zn substitution in the as-prepared Zn_(0.167)Sn_(0.833)S_(2) alloy.Furthermore,the photodetector based on the Zn_(0.167)Sn_(0.833)S_(2) alloy demonstrated a high on/off ratio of 51 under white light,a wide spectral response range from 350 nm to 900 nm,and a broad dynamic power range of 80 dB under 638-nm illumination.In terms of transport properties,field-effect transistors(FETs)based on Zn_(0.167)Sn_(0.833)S_(2) achieved a carrier mobility of 6.5 cm^(2)·V^(-1)·s^(-1),which is six times higher than that of SnS_(2).This alloy semiconductor showcases significantly enhanced electronic and optoelectronic properties,offering great potential for the development of high-resolution photodetection technologies.
基金supported by the National Natural Science Foundation of China(Nos.22178221,22208221)the Shenzhen Science and Technology Program(Nos.JCYJ20220818095805012,JCYJ20230808105109019)+2 种基金the Natural Science Foundation of Guangdong Province(Nos.2024A1515011078,2024A1515011507)the Scientific Foundation for Youth Scholars of Shenzhen University(868-000001032522,827-0001004)the Instrumental Analysis Center of Shenzhen University for the assistance with the Electron Microscope technical support。
文摘To advance the application of layered oxide cathodes in fast-charging sodium-ion batteries,it is crucial to not only suppress irreversible phase transitions but also improve the rate capability of cathode materials and optimize Na^(+)diffusion kinetics to ensure high capacity output at various charge-discharge rates.In this research,the targeted F-substitution with a heavy ratio in oxygen anion layer optimizes the Na^(+)diffusion path and electronic conductivity of the material,thereby decreasing the Na^(+)diffusion barrier and imparting high-rate performance.At a 20 C rate,the cathode achieves a capacity of over 80 mAh g^(-1)with stable cycling performance.Additionally,the dual rivet effect between the transition metal layer and oxygen layer prevents significant phase transitions during charge/discharge within the 2-4.2 V range for the modified cathode.As a result,the F-substituted oxygen anion layer improved Na^(+)diffusion,electronic conductivity,and crystal plane structure stability,which led to the development of a highperformance,fast-charging sodium-ion battery(SIB),opening new avenues for commercial applications.
基金supported by STI 2030-Major Project(2023ZD04069)the National Natural Science Foundation of China(32472129,U24A20392,32201841)+1 种基金Regional Joint Youth Fund for Basic and Applied Basic Research Foundation of Guangdong Province(2022 A1515110454)Science and Technology Projects in Guangzhou(2023B03J1355).
文摘Grain size is a crucial factor influencing both rice yield and appearance quality.In this study,we identified GL6.1 as a gene associated with rice grain size by map-based cloning.The GL6.1 encodes a protein with CC-NB-LRR domain,a structural motif related to rice disease resistance.Genetic transformation experiments and the construction of gene pyramiding lines indicate that GL6.1 functions as a negative regulatory factor for rice grain length.By the analysis of SSSLs with diverse donor parents,a total of 11 single nucleotide polymorphisms(SNPs)are identified that are closely associated with the phenotype variations.A yeast one-hybrid library screening revealed that GL6.1 interacts with OsWRKY53,a transcription factor associated with rice disease resistance.Furthermore,RNA-seq assay also revealed the involvement of pathways associated with disease resistance,hinting at a multifaceted role for GL6.1 in both yield and stress tolerance traits in rice.These results indicate that the cloning and in-depth studies of GL6.1 would provide valuable insights into the interplay among high yield,superior quality,and stress tolerance,which are critical goals for rice breeding.
基金supported by the National Natural Science Foundation of China[Grant No.:32070438].
文摘Understanding the molecular relevance of metabolic rate(MR)is crucial for unveiling the mechanisms driving the evolution of animals.In this study,we investigated the association between mitochondrial DNA characteristics and both resting and maximal MRs in conjunction with life-history traits among 139 species of teleost fish,We gathered fish MR data from various sources and procured sequences of 13 mitochondrial protein-encoding genes.We calculated the absolute substitution rate for entire nucleotide sequences and 4-fold degenerate sites of each gene,along with encoding amino acid sequences.Using the phylogenetic comparative method,we then explored the associations between MR and mitochondrial DNA absolute substitution rate.Additionally,we screened MR-associated single nucleotide variants in mitochondrial DNA.The findings indicate no positive correlation between MRs and any substitution rate values of both combined sequences and individual mitochondrial protein-coding genes,refuting the MR hypothesis.Instead,both maximum body size and longevity correlated negatively with molecular substitution rates,suggesting their influences on both mutation and fixation within mitochondrial genes in fish.Results also revealed significant correlations between base variation at ATP6_169 and both resting MR and maximum MR,identifying the unique ATP6_169G in Scombridae fish,which results in an extremely low isoelectric point(pl)value of the ATP6 protein.Considering its functional significance,the ATP6_169G in Scombridae fish might link to their lifestyle characterized by fast locomotion and high metabolic demands alongside a slower molecular evolutionary rate.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.B240201068)the National Natural Science Foundation of China(Grant No.42361144861)the National Basic Research Program of China(Grant No.2014CB954303).
文摘The relationship between ecosystem services(ES)and human well-being(HWB)is fundamental to the science and practice of sustainability.However,studies have shown conflicting results,which has been attributed to the influences of indicators,contexts,and scales.Yet,another potential factor,which has been overlooked,may be the mixed use of spatial and temporal approaches.Using twelve ES and seven well-being indicators and multiple statistical methods,we quantified and compared the spatial and temporal ES–HWB relationships for Inner Mongolia,China.The spatial and temporal relationships differed in both correlation direction and strength.Most relationships of economic and employment-related indicators with food provisioning and supporting services were temporally positive but spatially nonsignificant or negative.Some relationships of economic and employmentrelated indicators with water retention,sandstorm prevention,and wind erosion were temporally negative but spatially complex.However,the spatial and temporal ES–HWB relationships could also be similar in some cases.We conclude that although both the spatial and temporal approaches have merits,space generally cannot substitute for time in the study of ES–HWB relationship.Our study helps reconcile the seemingly conflicting findings in the literature,and suggests that future studies should explicitly distinguish between the spatial and temporal ES–HWB relationships.
基金supported by the National Natural Science Foundation of China(22275072 and 62105184)the Natural Science Foundation of Guangdong Province(2020A1515010622)+1 种基金the Project of Science and Technology of Guangzhou(2024A04J3712)the Teli Young Scholar Program of Beijing Institute of Technology.
文摘Donor-acceptor(D-A)compounds are particularly important in optoelectronic and biological applications.However,they are normally synthesized in the presence of transition metal catalysts.Herein,we report a metal-free method by a complexmediated nucleophilic aromatic substitution of aryl nitriles with amines.The method can lead to rich D-A type aggregation-induced emission luminogens(AIEgens)with tunable properties.They emit from deep-blue to yellow-green and possess high photoluminescence quantum yields up to 70.5%in the aggregate state.Interestingly,the suppression of intramolecular flapping is proved to play an indispensable role in the AIE behavior,which is different from the mechanism met in other AIEgens.Moreover,the biocompatible AIEgens possess specific staining of lipid droplets in HeLa cells and the superiority of identifying fatty liver over traditional Oil Red O staining is exhibited.
基金Funded by the Breeding Project of Anhui Polytechnic University(No.2019YQQ027)the Scientific Research Foundation of Anhui Polytechnic University(No.xjky2022016)+1 种基金the Open Research Found of Anhui Key Laboratory of High-performance Non-ferrous Metal Materials(No.YSJS-2023-07)the Innovative Entrepreneurship Training Program for College Students in Anhui Province(No.S202210363391)。
文摘A series of CoS_(2-x)Se_(x)(x=0.05,0.1,0.2,0.3,and 2)composite catalysts were synthesized on carbon fiber paper via the hydrothermal method with Se doping.By precisely controlling the reaction temperature and Se doping level,a hollow spherical catalyst structure composed of CoSSe was successfully synthesized,which exhibited exceptional activity for hydrogen evolution in acidic solutions.The influences of Se doping on the microstructure and catalytic mechanism of hydrogen evolution reaction(HER)of these composites were systematically investigated.The experimental results reveal that the hollow spherical sample displays an overpotential value of 143 mV along with a Tafel slope value of 69.8 mV·dec^(-1)at a current density of 10 mA·cm^(-2)in an acid aqueous solution.Furthermore,it demonstrates remarkable cycling stability after undergoing 3000 cycles.The comprehensive analysis indicates that Se doping optimizes the electronic structure and enhances conductivity,meanwhile the unique hollow spherical architecture increases active sites for HER and significantly improves overall electrocatalytic performance.
基金supported by the National Key Scientific Research Project(No.2022YFB2502300)the National Natural Science Foundation of China(No.52071085).
文摘P3-type manganese-iron-based cathodes with high specific capacity and abundant resource have attracted considerable attention for sodium-ion batteries.However,the long-term cycle stability of P3-type cathodes is still not satisfactory.In this work,we design a new quaternary manganese-iron-based cathode material(P3-Na_(0.54)Mn_(0.64)Fe_(_(0.1)6)Mg_(0.1)Cu_(0.1)O_(2))by Cu substitution.The strong covalent Cu-O bonds improve the structural stability and the reversibility of O redox during charge and discharge processes.Cu substitution also mitigates the structure change with less unit cell volume variation,and improves the Na-ion transport kinetics effectively.As a result,NMFMC delivers much improved cycling stability and rate capability compared with NMFM.It reveals that the charge compensation of NMFMC is mainly contributed by Mn^(3+/4+),Fe^(3+/3.5+)and O_(2-/-)during the charge and discharge processes,and Cu substitution can also enhance the activity and reversibility of Fe redox.This strategy provides a new pathway toward improving the stability and O redox reversibility of P3-type cathode materials for sodium-ion batteries.
基金financially supported by Natural Science Foundation of Hebei Province(Nos.B2020203037,F2021203097)Science Research Project of Hebei Education Department(No.JZX2024022)National Natural Science Foundation of China(Nos.52022088,51971245)。
文摘Halide electrolytes,renowned for their excellent electrochemical stability and wide voltage window,exhibit significant potential in the development of high energy density solid-state batteries featuring high voltage cathode materials.In this study,we present the development and synthesis of a 0.6Li_(2)S-ZrCl_(4)solid electrolyte,demonstrating an ion conductivity of 1.9×10^(–3)S/cm at 25°C.Under a pressure of 500 MPa,the relative density of the electrolyte can reach 97.37%,showcasing its commendable compressibility.0.6Li_(2)S-ZrCl_(4)served as the electrolyte,and we assembled batteries utilizing a LiCoO_(2)(LCO)positive electrode,Li_(9.54)Si_(1.74)P_(1.44)S_(11.7)Cl_(0.3)(LSPSCl)coating,and Li-In negative electrode for laboratory testing.At 25°C,this all-solid-state battery demonstrated an impressive discharge capacity retention rate of86.99%(with a final discharge specific capacity of 110.5 m Ah/g)after 250 cycles at 24 m A/g and 100 MPa stack pressure.Upon substituting the positive electrode material with LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811)and assembling an all-solid-state battery,it demonstrated a discharge capacity retention rate of 74.17%after200 cycles at 3.6 m A/g and 100 MPa stack pressure in an environment at 25°C(with a final discharge specific capacity of 103.3 m A/g).Our findings hold significant implications for the design of novel superionic conductors,thereby contributing to the advancement of all-solid-state battery technology.
