Forced dissociation of selectin-ligand complex is crucial to such biological processes as leukocyte recruitment,thrombosis formation,as well as tumor metastasis<sup>[</sup>1].Although several assays and te...Forced dissociation of selectin-ligand complex is crucial to such biological processes as leukocyte recruitment,thrombosis formation,as well as tumor metastasis<sup>[</sup>1].Although several assays and techniques,e.g.,dynamic force spectroscopy（DFS）,have been applied to probe the complex at single-bond level,the discrepancies in the loading rate dependence of bond rupture force were found in the assays,presumably due to the different pathways in energy landscape and binding kinetics of molecular complexes<sup>[2]</sup>.However,the underlying mechanisms remain unclear.Here an optical trap（OT）assay was used to quantify the bond rupture at r<sub>f</sub>≤20 pN/s展开更多
Owing to the merits of high energy density,as well as clean and sustainable properties,hydrogen has been deemed to be a prominent alternative energy to traditional fossil fuels.Electrocatalytic hydrogen evolution reac...Owing to the merits of high energy density,as well as clean and sustainable properties,hydrogen has been deemed to be a prominent alternative energy to traditional fossil fuels.Electrocatalytic hydrogen evolution reaction(HER)has been considered to be mostly promising for achieving green hydrogen production,and has been widely studied in acidic and alkaline solutions.In particular,HER in alkaline media has high potential to achieve large-scale hydrogen production because of the increased durability of electrode materials.However,for the currently most prominent catalyst Pt,its HER kinetics in an alkaline solution is generally 2e3 orders lower than that occurring in an acidic solution because of the low Hþconcentration in alkaline electrolytes.Fortunately,construction of heterostructured electrocatalysts has proved to be an efficient strategy for boosting alkaline HER kinetics because of their various structural merits.The synergistic effect is a unique characteristic of heterostructures,which means that one functional active site serves as a promoter for water dissociation and another one takes a charge of moderate hydrogen adsorption,thus synergistically improving HER performance.In addition,each building block of the heterostructures is tunable,providing moreflexibility and chances to construct optimal catalysts.Furthermore,due to the presence of Fermi energy difference between the two components at the interface,the electronic structure of each component could possibly be rationally modulated,thus much enhanced HER performance in alkaline electrolyte can be ach-ieved.With a deeper understanding of on nanoscience and rapid development of nanotechnology,more sophisticated alternative designing strategies have been explored for constructing high-performance heterostructured electro-catalysts.This review presents an outline of the latest development of heterostructured catalysts toward alkaline HER and the rational design principles for constructing interfacial heterostructures to accelerate alkaline HER kinetics.The basic reaction pathways of HER in alkaline media arefirst described,and then emerging efficient strategies to promote alkaline HER kinetics,including synergistic effect,strain effect,electronic interaction,phase engineering,and ar-chitecture engineering.Finally,current existing challenges and research opportunities that deserve further investi-gation are proposed for the consideration of novel heterostructures towards practical applications.展开更多
Copolymer of acrylic acid and maleic acid(PMA)was used to remove Hg^2+from aqueous solution by complexation-ultrafiltration(C-UF)through rotating disk membrane(RDM).The effects of P/M(mass ratio of PMA to metal ions),...Copolymer of acrylic acid and maleic acid(PMA)was used to remove Hg^2+from aqueous solution by complexation-ultrafiltration(C-UF)through rotating disk membrane(RDM).The effects of P/M(mass ratio of PMA to metal ions),pH and rotation speed(N)on the interception of Hg^2+were investigated.The interception could reach 99.7%at pH 7.0,P/M 6 and N less than 1890 r/min.The shear stability of PMA-Hg complex was studied by RDM.The critical rotation speed,at which the interception starts to decrease,was 1890 r/min,and the critical shear rate,the smallest shear rate at which PMA-Hg complex begins to dissociate,was 2.50×10^5s^-1 at pH 7.0.Furthermore,the critical radii were obtained at different rotation speeds and pHs.The results showed that the critical radius decreased with the rotation speed and increased with pH.Shear induced dissociation coupling with ultra?ltration(SID-UF)was efficiently used to recover Hg^2+and PMA.展开更多
To further test whether polynitriprismanes are capable of being potential high energy density materials （HEDMs）, extensive theoretical calculations were carried out to investigate on a series of polynitrotriprisman...To further test whether polynitriprismanes are capable of being potential high energy density materials （HEDMs）, extensive theoretical calculations were carried out to investigate on a series of polynitrotriprismanes （PNNPs）： C6H6-.（NO2）. （n=1-6） Heats of formation （HOFs）, strain energies （SE）, and disproportionation energy （DE） were obtained using B3LYP/6-311＋G（2df, 2p）//B3LYP/6-31G＊ method by designing different isodesmic reactions, respectively. Detonation properties of PNNPs were obtained by the well-known KAMLET-JACOBS equations, using the predicted densities （p） obtained by Monte Carlo method and HOFs. It is found that they increase as the number of nitro groups n varies from 1 to 6, and PNNPs with n〉4 have excellent detonation properties The relative stability and the pyrolysis mechanism of PNNPs were evaluated by the calculated bond dissociation energy （BDE）. The comparison of BDE suggests that rupturing the C--C bond is the trigger for thermolysis of PNNPs. The computed BDE for cleavage of C--C bond （88.5 kJ/mol） further demonstrates that only the hexa-nitrotriprismane can be considered to be the target of HEDMs.展开更多
For minerals containing multivalent elements,their stabilities depend not only on pressure(P),temperature(T),and bulk chemical composition,but also the redox state.This applies to many ore forming minerals,such that t...For minerals containing multivalent elements,their stabilities depend not only on pressure(P),temperature(T),and bulk chemical composition,but also the redox state.This applies to many ore forming minerals,such that the redox state and its fluctuations in hydrothermal systems have long been considered as important controlling factors for the transport and deposition of ores.展开更多
Ternary strategy has demonstrated great potential in promoting the power conversion efficiency(PCE)of bulk heterojunction organic solar cells(BHJ OSCs).Two new polymer donors,TPQ-2 F-2 Cl and TPQ-2 F-4 F,were synthesi...Ternary strategy has demonstrated great potential in promoting the power conversion efficiency(PCE)of bulk heterojunction organic solar cells(BHJ OSCs).Two new polymer donors,TPQ-2 F-2 Cl and TPQ-2 F-4 F,were synthesized with chlorinated and fluorinated aromatic side chains,respectively,which contributed to distinct noncovalent interactions.Compared with the PM 6:L 8-BO host system,the TPQ-2 F-2 Cl based ternary OSCs obtained enhanced exciton dissociation and more balanced carrier mobility.Moreover,benefiting from the favorable miscibility of the PM 6:L 8-BO:TPQ-2 F-2 Cl blend,the ternary blending film featured a well-defined fibrillar morphology and improved molecular ordering.Consequently,the optimal PM 6:L 8-BO:TPQ-2 F-2 Cl device achieved a more outstanding PCE of 18.2%,a higher open circuit voltage(V_(oc)),and a better fill factor(FF)in comparison with the binary device(PCE=17.7%).In contrast,the addition of TPQ-2 F-4 F would generate excessive aggregation of blend,thereby reducing the PCE of ternary OSCs(16.0%).This work shows a promising idea for designing efficient third component donor polymers.展开更多
Carbon nanotube formation exemplifies atomically precise self-assembly,where atomic interactions dynamically engineer nanoscale architectures with emergent properties that transcend classical material boundaries.Howev...Carbon nanotube formation exemplifies atomically precise self-assembly,where atomic interactions dynamically engineer nanoscale architectures with emergent properties that transcend classical material boundaries.However,elucidating the transient molecular intermediates remains a critical mechanistic frontier.This study investigates the atomic-scale nucleation process of single-walled carbon nanotubes(SWCNTs)from acetylene on iron(Fe)clusters,utilizing GFN(-x)TB-based nanoreactor molecular dynamics simulations.The simulations reveal a consistent nucleation pathway,regardless of iron cluster size(Fe_(13),Fe_(38),Fe_(55)),where the chemisorption and dissociation of acetylene molecules on the Fe clusters lead to the formation of C_(2)H and C_(2)intermediates.These species then undergo oligomerization,initiating the growth of carbon chains.As the chains cross-link and cyclize,five-membered carbon rings are preferentially formed,which eventually evolve into six-membered rings and more complex sp2-hybridized carbon networks,resembling the cap structures of nascent SWCNTs.Although the nucleation mechanism remains similar across all cluster sizes,larger clusters show enhanced catalytic activity,leading to higher molecular weight hydrocarbons and more extensive carbocyclic networks due to their higher density of active sites per reacting molecule.Crucially,the study highlights the role of C_(2)H as the key active species in the carbon network formation process.These findings offer critical insights into the initial stages of SWCNT nucleation,contributing to a deeper understanding of the mechanisms driving SWCNT growth and guiding the development of optimized synthetic strategies.展开更多
基金supported by National Natural Science Foundation of China grants 10902117, 31230027,30730032,and 10332060
文摘Forced dissociation of selectin-ligand complex is crucial to such biological processes as leukocyte recruitment,thrombosis formation,as well as tumor metastasis<sup>[</sup>1].Although several assays and techniques,e.g.,dynamic force spectroscopy（DFS）,have been applied to probe the complex at single-bond level,the discrepancies in the loading rate dependence of bond rupture force were found in the assays,presumably due to the different pathways in energy landscape and binding kinetics of molecular complexes<sup>[2]</sup>.However,the underlying mechanisms remain unclear.Here an optical trap（OT）assay was used to quantify the bond rupture at r<sub>f</sub>≤20 pN/s
基金supported by the National Natural Science Foundation of China(No.22179098)。
文摘Owing to the merits of high energy density,as well as clean and sustainable properties,hydrogen has been deemed to be a prominent alternative energy to traditional fossil fuels.Electrocatalytic hydrogen evolution reaction(HER)has been considered to be mostly promising for achieving green hydrogen production,and has been widely studied in acidic and alkaline solutions.In particular,HER in alkaline media has high potential to achieve large-scale hydrogen production because of the increased durability of electrode materials.However,for the currently most prominent catalyst Pt,its HER kinetics in an alkaline solution is generally 2e3 orders lower than that occurring in an acidic solution because of the low Hþconcentration in alkaline electrolytes.Fortunately,construction of heterostructured electrocatalysts has proved to be an efficient strategy for boosting alkaline HER kinetics because of their various structural merits.The synergistic effect is a unique characteristic of heterostructures,which means that one functional active site serves as a promoter for water dissociation and another one takes a charge of moderate hydrogen adsorption,thus synergistically improving HER performance.In addition,each building block of the heterostructures is tunable,providing moreflexibility and chances to construct optimal catalysts.Furthermore,due to the presence of Fermi energy difference between the two components at the interface,the electronic structure of each component could possibly be rationally modulated,thus much enhanced HER performance in alkaline electrolyte can be ach-ieved.With a deeper understanding of on nanoscience and rapid development of nanotechnology,more sophisticated alternative designing strategies have been explored for constructing high-performance heterostructured electro-catalysts.This review presents an outline of the latest development of heterostructured catalysts toward alkaline HER and the rational design principles for constructing interfacial heterostructures to accelerate alkaline HER kinetics.The basic reaction pathways of HER in alkaline media arefirst described,and then emerging efficient strategies to promote alkaline HER kinetics,including synergistic effect,strain effect,electronic interaction,phase engineering,and ar-chitecture engineering.Finally,current existing challenges and research opportunities that deserve further investi-gation are proposed for the consideration of novel heterostructures towards practical applications.
基金Project(21476265)supported by the National Natural Science Foundation of China。
文摘Copolymer of acrylic acid and maleic acid(PMA)was used to remove Hg^2+from aqueous solution by complexation-ultrafiltration(C-UF)through rotating disk membrane(RDM).The effects of P/M(mass ratio of PMA to metal ions),pH and rotation speed(N)on the interception of Hg^2+were investigated.The interception could reach 99.7%at pH 7.0,P/M 6 and N less than 1890 r/min.The shear stability of PMA-Hg complex was studied by RDM.The critical rotation speed,at which the interception starts to decrease,was 1890 r/min,and the critical shear rate,the smallest shear rate at which PMA-Hg complex begins to dissociate,was 2.50×10^5s^-1 at pH 7.0.Furthermore,the critical radii were obtained at different rotation speeds and pHs.The results showed that the critical radius decreased with the rotation speed and increased with pH.Shear induced dissociation coupling with ultra?ltration(SID-UF)was efficiently used to recover Hg^2+and PMA.
基金Projects(2006DFA41090,2007DFA40680) supported by the International Cooperation Project on Traditional Chinese Medicines of Ministry of Science and Technology of ChinaProject(20475066) supported by the National Natural Science Foundation of China
文摘To further test whether polynitriprismanes are capable of being potential high energy density materials （HEDMs）, extensive theoretical calculations were carried out to investigate on a series of polynitrotriprismanes （PNNPs）： C6H6-.（NO2）. （n=1-6） Heats of formation （HOFs）, strain energies （SE）, and disproportionation energy （DE） were obtained using B3LYP/6-311＋G（2df, 2p）//B3LYP/6-31G＊ method by designing different isodesmic reactions, respectively. Detonation properties of PNNPs were obtained by the well-known KAMLET-JACOBS equations, using the predicted densities （p） obtained by Monte Carlo method and HOFs. It is found that they increase as the number of nitro groups n varies from 1 to 6, and PNNPs with n〉4 have excellent detonation properties The relative stability and the pyrolysis mechanism of PNNPs were evaluated by the calculated bond dissociation energy （BDE）. The comparison of BDE suggests that rupturing the C--C bond is the trigger for thermolysis of PNNPs. The computed BDE for cleavage of C--C bond （88.5 kJ/mol） further demonstrates that only the hexa-nitrotriprismane can be considered to be the target of HEDMs.
文摘For minerals containing multivalent elements,their stabilities depend not only on pressure(P),temperature(T),and bulk chemical composition,but also the redox state.This applies to many ore forming minerals,such that the redox state and its fluctuations in hydrothermal systems have long been considered as important controlling factors for the transport and deposition of ores.
基金Projects(52125306,21875286)supported by the National Natural Science Foundation of China。
文摘Ternary strategy has demonstrated great potential in promoting the power conversion efficiency(PCE)of bulk heterojunction organic solar cells(BHJ OSCs).Two new polymer donors,TPQ-2 F-2 Cl and TPQ-2 F-4 F,were synthesized with chlorinated and fluorinated aromatic side chains,respectively,which contributed to distinct noncovalent interactions.Compared with the PM 6:L 8-BO host system,the TPQ-2 F-2 Cl based ternary OSCs obtained enhanced exciton dissociation and more balanced carrier mobility.Moreover,benefiting from the favorable miscibility of the PM 6:L 8-BO:TPQ-2 F-2 Cl blend,the ternary blending film featured a well-defined fibrillar morphology and improved molecular ordering.Consequently,the optimal PM 6:L 8-BO:TPQ-2 F-2 Cl device achieved a more outstanding PCE of 18.2%,a higher open circuit voltage(V_(oc)),and a better fill factor(FF)in comparison with the binary device(PCE=17.7%).In contrast,the addition of TPQ-2 F-4 F would generate excessive aggregation of blend,thereby reducing the PCE of ternary OSCs(16.0%).This work shows a promising idea for designing efficient third component donor polymers.
基金supported by the National Key R&D Program of China(2022YFA1604100)the National Natural Science Foundation of China(22302220,22372187,1972157,21972160,22402218)+2 种基金the National Science Fund for Distinguished Young Scholars of China(22225206)the Fundamental Research Program of Shanxi Province(202203021222403)the Youth Innovation Promotion Association CAS(2020179)。
文摘Carbon nanotube formation exemplifies atomically precise self-assembly,where atomic interactions dynamically engineer nanoscale architectures with emergent properties that transcend classical material boundaries.However,elucidating the transient molecular intermediates remains a critical mechanistic frontier.This study investigates the atomic-scale nucleation process of single-walled carbon nanotubes(SWCNTs)from acetylene on iron(Fe)clusters,utilizing GFN(-x)TB-based nanoreactor molecular dynamics simulations.The simulations reveal a consistent nucleation pathway,regardless of iron cluster size(Fe_(13),Fe_(38),Fe_(55)),where the chemisorption and dissociation of acetylene molecules on the Fe clusters lead to the formation of C_(2)H and C_(2)intermediates.These species then undergo oligomerization,initiating the growth of carbon chains.As the chains cross-link and cyclize,five-membered carbon rings are preferentially formed,which eventually evolve into six-membered rings and more complex sp2-hybridized carbon networks,resembling the cap structures of nascent SWCNTs.Although the nucleation mechanism remains similar across all cluster sizes,larger clusters show enhanced catalytic activity,leading to higher molecular weight hydrocarbons and more extensive carbocyclic networks due to their higher density of active sites per reacting molecule.Crucially,the study highlights the role of C_(2)H as the key active species in the carbon network formation process.These findings offer critical insights into the initial stages of SWCNT nucleation,contributing to a deeper understanding of the mechanisms driving SWCNT growth and guiding the development of optimized synthetic strategies.
