[ Objective ] This study aimed to provide basic data for studying the relationship between structure and property of cellulose microspheres by measuring molecular weight of cellulose and cellulose microspheres with vi...[ Objective ] This study aimed to provide basic data for studying the relationship between structure and property of cellulose microspheres by measuring molecular weight of cellulose and cellulose microspheres with viscosity method and gel permeation chromatography （GPC） method. [ Method] In viscosity method, cadmium ethylenediamine was used as the solvent, intrinsic viscosity η of the solution was determined at 25 ℃ by using a Ubbelohde viscometer, to calculate the molecular weight of cellulose; in GPC method, 8% LiC1 / N, N-dimethylacetamide （LiC1/DMAc） was used as the solvent and 0.5% LiC1/DMAc was used as the mobile phase to determine the relative molecular weight and distribution of cellulose and cellulose microspheres. In addition, the determination results were analyzed to compare these two methods. [ Result ] Viscosity-average molecular weight Mr/ of cellulose and cellulose microspheres determined with viscosity method were 224,532 and 16,686, respectively; weight-average molecular weight Mw of cellulose and cellulose microspheres determined with GPC method were 284,196 and 22,345, respectively. [ Conclusion] The determination results of （;PC method are relatively close to the actual value and could truly reflect the characteristics of molecular weialat distribution of eellulose and cellulose mierosr, heres.展开更多
Herein,the successful preparation of a singleatom catalyst V-N-C using vanadium-doped zeolitic imidazolate framework(ZIF)-8 as a precursor is reported.The experimental results showed that the V-N-C had a good promotin...Herein,the successful preparation of a singleatom catalyst V-N-C using vanadium-doped zeolitic imidazolate framework(ZIF)-8 as a precursor is reported.The experimental results showed that the V-N-C had a good promoting effect on the hydrogen storage performance of MgH_(2),and the optimal addition amount of V-N-C was 10wt%.The hydrogenation and dehydrogenation apparent activation energies of 10 wt%V-N-C-catalyzed MgH_(2)were reduced by 44.9 and 53.5 kJ·mol^(-1),respectively,compared to those of additive-free MgH_(2).The 10 wt%V-N-C-catalyzed MgH_(2)could reabsorb 5.92 wt%of hydrogen in 50 min at 150℃,with a capacity retention rate of 99.1%after 30 cycles of hydrogen absorption and desorption.Mechanism analysis showed that V-N-C was partially transformed into VN and metallic V when it was milled with MgH_(2);the in-situ-formed VN and metallic V played an important role in improving the hydrogen storage performance of MgH_(2).This approach provides a potential solution for obtaining high-performance Mg-based hydrogen storage materials through synergistic interactions between V,N and C.展开更多
The performance of organic solar cells is significantly influenced by the acceptor molecular packing properties within the active layers,which is essential for optimizing charge dynamics and photovoltaic performance.H...The performance of organic solar cells is significantly influenced by the acceptor molecular packing properties within the active layers,which is essential for optimizing charge dynamics and photovoltaic performance.However,achieving precise control over this packaging structure presents a considerable challenge.Herein,we propose a dual additive strategy utilizing dibenzofuran and halogenated naphthalene to systematically manipulate molecular packing orientation and enhance the long-range molecular packing order of the acceptors.Dibenzofuran is crucial in promoting crystallinity within the material,facilitating the formation of an ordered structure,while halogenated naphthalene regulates the orientation of the molecules,ensuring proper alignment.Specifically,the combination of dibenzofuran and 1-chloronaphthalene promotes edge-on molecular packing and enhances the formation of nanofibrillar structures with improved order,leading to improved charge transport and device performance.Implementing this strategy in devices composed of PM6 and L8-BO has yielded a power conversion efficiency of 19.58%,accompanied by long-term stability.Similarly,1-fluoronaphthalene has also demonstrated effectiveness in improving molecular orientation and overall device efficiency,demonstrating the robustness of this dual additive strategy.By addressing the challenges associated with molecular packing and orientation in active layers,our result contributes valuable insights into optimizing organic solar cells for practical applications.展开更多
In the domain of data governance,crimes involving virtual currencies have emerged as an integral concern that cannot be overlooked.To address challenges such as the difficulty of evidence col-lection and the low proba...In the domain of data governance,crimes involving virtual currencies have emerged as an integral concern that cannot be overlooked.To address challenges such as the difficulty of evidence col-lection and the low probability of recovering stolen funds in virtual currency crimes,this paper proposes a new mechanism for the electronic storage and retrieval of evidence using blockchain technology,elab-orating on its core steps and underlying technology.Moreover,from the perspective of virtual currency transaction intermediaries,this study employs game theory to analyze the issue,constructing replicator dynamics equations,solving for the Jacobian matrix,and exploring the direction of game evolution and the factors influencing the decision-making of the participants.This analysis demonstrates that the decision-making of virtual currency criminals is impacted by this electronic evidence mechanism,which can deter illicit intermediaries from assisting in money laundering activities,thereby reducing the fea-sibility of committing crimes with virtual currencies.Lastly,the paper offers policy recommendations to enhance the implement ability of the evidence storage and retrieval mechanism in regulating virtual currency crimes.展开更多
When used in organic solar cells,poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)aligns interfacial energy levels,promotes hole extraction,blocks electrons,and optimizes the active layer’s morpholog...When used in organic solar cells,poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)aligns interfacial energy levels,promotes hole extraction,blocks electrons,and optimizes the active layer’s morphology.However,with an optimal thickness of approximately 30-40 nm,PEDOT:PSS has insufficient layer thickness tolerance,owing to its low conductivity and hole extraction property.Herein,a hole-selective-molecule doping strategy is proposed to enhance the properties of PEDOT:PSS by introducing MPA2FPh-BT-BA(abbreviated as 2F)into its layer.2F assembles at the anode to form interfacial dipoles due to its unique donor-acceptor-anchor molecular configuration,altering the anode work function and hole-selective extraction.Additionally,2F improves the aggregation properties of PEDOT:PSS by forming hydrogen bonds with the PSS group,enhancing the conductivity characteristics.These changes in the PEDOT:PSS layer further influence the overlaying morphology,leading to increased crystalline features of PM6 and the bulk heterojunction of PM6:Y6.When a 2F-PEDOT:PSS(2FPP)layer is used,power conversion efficiencies of 18.3%,19.2%,and 19.1%are achieved in PM6:Y6,PM6:BTP-eC9,and PM6:L8-BO devices,respectively,outperforming counterparts with PEDOT:PSS.Specifically,the performance of PM6:Y6 devices with a 2FPP layer of 170 nm remains at>15%,providing valuable guidance for designing a thickness-insensitive hole transport layer for high-efficiency organic solar cells.展开更多
基金Supported by Natural Science Foundation of Guangxi(0991024Z)
文摘[ Objective ] This study aimed to provide basic data for studying the relationship between structure and property of cellulose microspheres by measuring molecular weight of cellulose and cellulose microspheres with viscosity method and gel permeation chromatography （GPC） method. [ Method] In viscosity method, cadmium ethylenediamine was used as the solvent, intrinsic viscosity η of the solution was determined at 25 ℃ by using a Ubbelohde viscometer, to calculate the molecular weight of cellulose; in GPC method, 8% LiC1 / N, N-dimethylacetamide （LiC1/DMAc） was used as the solvent and 0.5% LiC1/DMAc was used as the mobile phase to determine the relative molecular weight and distribution of cellulose and cellulose microspheres. In addition, the determination results were analyzed to compare these two methods. [ Result ] Viscosity-average molecular weight Mr/ of cellulose and cellulose microspheres determined with viscosity method were 224,532 and 16,686, respectively; weight-average molecular weight Mw of cellulose and cellulose microspheres determined with GPC method were 284,196 and 22,345, respectively. [ Conclusion] The determination results of （;PC method are relatively close to the actual value and could truly reflect the characteristics of molecular weialat distribution of eellulose and cellulose mierosr, heres.
基金financially supported by the National Natural Science Foundation of China(Nos.52261038 and 51861002)Nanning Excellent Young Talents Cultivation Project of Scientific and Technological Innovation and Entrepreneurship(No.RC20220102)。
文摘Herein,the successful preparation of a singleatom catalyst V-N-C using vanadium-doped zeolitic imidazolate framework(ZIF)-8 as a precursor is reported.The experimental results showed that the V-N-C had a good promoting effect on the hydrogen storage performance of MgH_(2),and the optimal addition amount of V-N-C was 10wt%.The hydrogenation and dehydrogenation apparent activation energies of 10 wt%V-N-C-catalyzed MgH_(2)were reduced by 44.9 and 53.5 kJ·mol^(-1),respectively,compared to those of additive-free MgH_(2).The 10 wt%V-N-C-catalyzed MgH_(2)could reabsorb 5.92 wt%of hydrogen in 50 min at 150℃,with a capacity retention rate of 99.1%after 30 cycles of hydrogen absorption and desorption.Mechanism analysis showed that V-N-C was partially transformed into VN and metallic V when it was milled with MgH_(2);the in-situ-formed VN and metallic V played an important role in improving the hydrogen storage performance of MgH_(2).This approach provides a potential solution for obtaining high-performance Mg-based hydrogen storage materials through synergistic interactions between V,N and C.
基金the financial support from the National Natural Science Foundation of China(62275057)the Guangxi Natural Science Foundation(2023GXNSFFA026004)+2 种基金the Guangxi Talent Program("Highland of Innovation Talents")the Shenzhen High-tech Development Special Plan-Pingshan Districts Innovation Platform Project(29853M-KCJ-2023-002-04)Industry and Energy(MOTIE),Republic of Korea(Project No.:RS-2025-02413058)。
文摘The performance of organic solar cells is significantly influenced by the acceptor molecular packing properties within the active layers,which is essential for optimizing charge dynamics and photovoltaic performance.However,achieving precise control over this packaging structure presents a considerable challenge.Herein,we propose a dual additive strategy utilizing dibenzofuran and halogenated naphthalene to systematically manipulate molecular packing orientation and enhance the long-range molecular packing order of the acceptors.Dibenzofuran is crucial in promoting crystallinity within the material,facilitating the formation of an ordered structure,while halogenated naphthalene regulates the orientation of the molecules,ensuring proper alignment.Specifically,the combination of dibenzofuran and 1-chloronaphthalene promotes edge-on molecular packing and enhances the formation of nanofibrillar structures with improved order,leading to improved charge transport and device performance.Implementing this strategy in devices composed of PM6 and L8-BO has yielded a power conversion efficiency of 19.58%,accompanied by long-term stability.Similarly,1-fluoronaphthalene has also demonstrated effectiveness in improving molecular orientation and overall device efficiency,demonstrating the robustness of this dual additive strategy.By addressing the challenges associated with molecular packing and orientation in active layers,our result contributes valuable insights into optimizing organic solar cells for practical applications.
基金Supported by the National Natural Science Foundation of China(72274010,71932002,71904010)。
文摘In the domain of data governance,crimes involving virtual currencies have emerged as an integral concern that cannot be overlooked.To address challenges such as the difficulty of evidence col-lection and the low probability of recovering stolen funds in virtual currency crimes,this paper proposes a new mechanism for the electronic storage and retrieval of evidence using blockchain technology,elab-orating on its core steps and underlying technology.Moreover,from the perspective of virtual currency transaction intermediaries,this study employs game theory to analyze the issue,constructing replicator dynamics equations,solving for the Jacobian matrix,and exploring the direction of game evolution and the factors influencing the decision-making of the participants.This analysis demonstrates that the decision-making of virtual currency criminals is impacted by this electronic evidence mechanism,which can deter illicit intermediaries from assisting in money laundering activities,thereby reducing the fea-sibility of committing crimes with virtual currencies.Lastly,the paper offers policy recommendations to enhance the implement ability of the evidence storage and retrieval mechanism in regulating virtual currency crimes.
基金support from the National Natural Science Foundation of China(62275057)the Guangxi Natural Science Foundation(2022GXNSFDA035066 and 2023GXNSFFA026004)+3 种基金the Innovation Project of Guangxi Graduate Education(YCBZ2024034)supported by the National Research Foundation(NRF)of Korea(2020R1A2C3004477)Natural Science Foundation of Ningbo under grant No.2022J149Natural Science Foundation of Ningbo under grant No.2022A-230-G.
文摘When used in organic solar cells,poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)aligns interfacial energy levels,promotes hole extraction,blocks electrons,and optimizes the active layer’s morphology.However,with an optimal thickness of approximately 30-40 nm,PEDOT:PSS has insufficient layer thickness tolerance,owing to its low conductivity and hole extraction property.Herein,a hole-selective-molecule doping strategy is proposed to enhance the properties of PEDOT:PSS by introducing MPA2FPh-BT-BA(abbreviated as 2F)into its layer.2F assembles at the anode to form interfacial dipoles due to its unique donor-acceptor-anchor molecular configuration,altering the anode work function and hole-selective extraction.Additionally,2F improves the aggregation properties of PEDOT:PSS by forming hydrogen bonds with the PSS group,enhancing the conductivity characteristics.These changes in the PEDOT:PSS layer further influence the overlaying morphology,leading to increased crystalline features of PM6 and the bulk heterojunction of PM6:Y6.When a 2F-PEDOT:PSS(2FPP)layer is used,power conversion efficiencies of 18.3%,19.2%,and 19.1%are achieved in PM6:Y6,PM6:BTP-eC9,and PM6:L8-BO devices,respectively,outperforming counterparts with PEDOT:PSS.Specifically,the performance of PM6:Y6 devices with a 2FPP layer of 170 nm remains at>15%,providing valuable guidance for designing a thickness-insensitive hole transport layer for high-efficiency organic solar cells.
