Dichloromethane(DCM)dehalogenase stands as a crucial enzyme implicated in the degradation of methylene chloride across diverse environmental and biological contexts.However,the unbinding pathways of ligands from DCM d...Dichloromethane(DCM)dehalogenase stands as a crucial enzyme implicated in the degradation of methylene chloride across diverse environmental and biological contexts.However,the unbinding pathways of ligands from DCM dehalogenase remain unexplored.In order to gain a deeper understanding of the binding sites and dissociation pathways of dichloromethane(DCM)and glutathione(GSH)from the DCM dehalogenase,random accelerated molecular dynamics(RAMD)simulations were performed,in which DCM and GSH were forced to leave the active site.The protein structure was predicted using Alphafold2,and the conformations of GSH and DCM in the binding pocket were predicted by docking.A long equilibrium simulation was conducted to validate the structure of the complex.The results show that GSH is most commonly observed in three main pathways,one of which is more important than the other two.In addition,DCM was observed to escape along a unique pathway.The key residues and protein helices of each pathway were identified.The results can provide a theoretical foundation for the subsequent dissociation mechanism of DCM dehalogenase.展开更多
Alkaline water electrolysis(AWE)is the most mature technology for hydrogen production by water electrolysis.Alkaline water electrolyzer consists of multiple electrolysis cells,and a single cell consists of a diaphragm...Alkaline water electrolysis(AWE)is the most mature technology for hydrogen production by water electrolysis.Alkaline water electrolyzer consists of multiple electrolysis cells,and a single cell consists of a diaphragm,electrodes,bipolar plates and end plates,etc.The existing industrial bipolar plate channel is concave-convex structure,which is manufactured by complicated and high-cost mold punching.This structure still results in uneven electrolyte flow and low current density in the electrolytic cell,further increasing in energy consumption and cost of AWE.Thereby,in this article,the electrochemical and flow model is firstly constructed,based on the existing industrial concave and convex flow channel structure of bipolar plate,to study the current density,electrolyte flow and bubble distribution in the electrolysis cell.The reliability of the model was verified by comparison with experimental data in literature.Among which,the electrochemical current density affects the bubble yield,on the other hand,the generated bubbles cover the electrode surface,affecting the active specific surface area and ohmic resistance,which in turn affects the electrochemical reaction.The result indicates that the flow velocity near the bottom of the concave ball approaches zero,while the flow velocity on the convex ball surface is significantly higher.Additionally,vortices are observed within the flow channel structure,leading to an uneven distribution of electrolyte.Next,modelling is used to optimize the bipolar plate structure of AWE by simulating the electrochemistry and fluid flow performances of four kinds of structures,namely,concave and convex,rhombus,wedge and expanded mesh,in the bipolar plate of alkaline water electrolyzer.The results show that the expanded mesh channel structure has the largest current density of 3330 A/m^(2)and electrolyte flow velocity of 0.507 m/s in the electrolytic cell.Under the same current density,the electrolytic cell with the expanded mesh runner structure has the smallest potential and energy consumption.This work provides a useful guide for the comprehensive understanding and optimization of channel structures,and a theoretical basis for the design of large-scale electrolyzer.展开更多
A series of Cr^(3+)-substituted Na_(1+x)Ti_(2−x)Cr_(x)P_(3)O_(12)(x=0.1,0.2,0.3,0.4,0.5,molar fraction)solid electrolytes were prepared by the solid-phase reaction method.The effects of Cr^(3+)ions on the phase compos...A series of Cr^(3+)-substituted Na_(1+x)Ti_(2−x)Cr_(x)P_(3)O_(12)(x=0.1,0.2,0.3,0.4,0.5,molar fraction)solid electrolytes were prepared by the solid-phase reaction method.The effects of Cr^(3+)ions on the phase composition,microstructure,and electrochemical ion conductivity of Na-based conductors were studied using X-ray powder diffraction,field emission scanning electron microscopy,and AC impedance measurement.The results show that the main crystal phase of NaTi_(2)(PO_(4))_(3) is formed in the solid electrolytes.The substitution of Ti4+sites by 15 at.%Cr^(3+)ions contributes to the enhancement of electrical conductivity,which is attributed to the combined effect of suppressing the formation of impurity phases,broadening ion channels,and improving the bonding degree of grains.Na_(1.3)Ti_(1.7)Cr_(0.3)P_(3)O_(12) electrolyte can obtain the best ionic conductivity of 6.13×10^(−6)S/cm at room temperature,which is 8 times that of the undoped NaTi_(2)(PO_(4))_(3) electrolyte.展开更多
Ether-based solvents generally show better affinity for lithium metal,and thus ether-based electrolytes(EBEs)are more inclined to form a uniform and thin solid electrolyte interface(SEI),ensuring the long cycle stabil...Ether-based solvents generally show better affinity for lithium metal,and thus ether-based electrolytes(EBEs)are more inclined to form a uniform and thin solid electrolyte interface(SEI),ensuring the long cycle stability of the lithium metal batteries(LMBs).Nonetheless,EBEs still face the challenge of oxidative decomposition under high voltage,which will corrode the structure of cathodes,destroy the stability of the electrode−electrolyte interface,and even cause safety risks.Herein,the types and challenges of EBEs are reviewed,the strategies for improving the high voltage stability of EBEs and constructing stable electrode−electrolyte interfaces are discussed in detail.Finally,the future perspectives and potential directions for composition optimization of EBEs and electrolyte−electrode interface regulation of high-voltage LMBs are explored.展开更多
The development of efficient nonprecious bifunctional electrocatalysts for water electrolysis is crucial to enhance the sluggish kinetics of the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).A sel...The development of efficient nonprecious bifunctional electrocatalysts for water electrolysis is crucial to enhance the sluggish kinetics of the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).A self-supporting,multiscale porous NiFeZn/NiZn-Ni catalyst with a triple interface heterojunction on nickel foam(NF)(NiFeZn/NiZn-Ni/NF)was in-situ fabricated using an electroplating-annealing-etching strategy.The unique multiinterface engineering and three-dimensional porous scaffold significantly modify the mass transport and electron interaction,resulting in superior bifunctional electrocatalytic performance for water splitting.The NiFeZn/NiZn-Ni/NF catalyst demonstrates low overpotentials of 187 m V for HER and 320 mV for OER at a current density of 600 mA/cm^(2),along with high durability over 150 h in alkaline solution.Furthermore,an electrolytic cell assembled with NiFeZn/NiZn-Ni/NF as both the cathode and anode achieves the current densities of 600 and 1000 m A/cm^(2) at cell voltages of 1.796 and 1.901 V,respectively,maintaining the high stability at 50 mA/cm^(2) for over 100 h.These findings highlight the potential of NiFeZn/NiZn-Ni/NF as a cost-effective and highly efficient bifunctional electrocatalyst for overall water splitting.展开更多
A mutant with abnormal hull was first discovered from a twin-seedling strain W2555 in rice （Oryza sativa L.）. The mutant had sparse branches and decreased number of florets from the base to the peak. Frequently, the...A mutant with abnormal hull was first discovered from a twin-seedling strain W2555 in rice （Oryza sativa L.）. The mutant had sparse branches and decreased number of florets from the base to the peak. Frequently, the florets at the top of the panicle did not develop completely. The underdeveloped florets often showed slender and white in their life cycle. Genetic analysis indicated that the mutant traits were controlled by a single recessive gene （temporarily designated as ah）. ah gene controlled the development of inflorescence meristem and the flower organ. The florets of mutant showed degenerated lemma and palea. Stamens and lodicules were homeoticly transformed into pistils and palea/lemma-like structures, respectively. It seemed that ah mutant phenotypes of the homeotic conversions in lodicules and stamens were very similar to that of the B loss-of-function spwl gene reported previously in rice.展开更多
Plants usually suffer drought stress during their growth process. As the photosynthetic activity center of plants, the leaf is the most sensitive organ under drought stress. In order to support the research on drought...Plants usually suffer drought stress during their growth process. As the photosynthetic activity center of plants, the leaf is the most sensitive organ under drought stress. In order to support the research on drought resistance of higher plants, this study reviewed the adaptation response and damage performance of epidermal structure, palisade tissue and spongy tissue, thickness, veins and stomata of plant leaves under drought stress.展开更多
Using interface engineering,a highly efficient catalyst with a shell@core structure was successfully synthesized by growing an amorphous material composed of Ni,Mo,and P on Cu nanowires(Ni-MoP@CuNWs).This catalyst onl...Using interface engineering,a highly efficient catalyst with a shell@core structure was successfully synthesized by growing an amorphous material composed of Ni,Mo,and P on Cu nanowires(Ni-MoP@CuNWs).This catalyst only requires an overpotential of 35 mV to reach a current density of 10 mA cm^(-2).The exceptional hydrogen evolution reaction(HER)activity is attributed to the unique amorphous rod-like nature of NiMoP@CuNWs,which possesses a special hydrophilic feature,en-hances mass transfer,promotes effective contact between the electrode and electrolyte solution,and exposes more active sites during the catalytic process.Density functional theory revealed that the introduction of Mo weakens the binding strength of the Ni site on the catalyst surface with the H atom and promotes the desorption process of the H_(2) product significantly.Owing to its facile syn-thesis,low cost,and high catalytic performance,this electrocatalyst is a promising option for com-mercial applications as a water electrolysis catalyst.展开更多
Calcium carbonate was synthesized in a CaCl2/NaCO3 mixed solution by using ethylenediaminetetraacetic acid （EDTA） as an additive. The thermodynamics and kinetics analyses indicate that although the driving force of ...Calcium carbonate was synthesized in a CaCl2/NaCO3 mixed solution by using ethylenediaminetetraacetic acid （EDTA） as an additive. The thermodynamics and kinetics analyses indicate that although the driving force of amorphous calcium carbonate （ACC） precipitation is always less than that of calcite and vaterite precipitation, the nucleation rate of ACC is greater than that of calcite and vaterite at the initial stage of the precipitation reaction. With the increasing incubation time, vaterite and calcite particles nucleate heterogeneously by using the as-formed particles as active sites. Scanning electron microscopy images indicate that the transformation mechanism of ACC and vaterite to calcite is the dissolution-recrystallisation reaction. The presence of EDTA not only improves the stabilities of ACC and vaterite, but also leads to forming enlongated, connected rhombohedral calcite crystals after incubation 7 days in solutions. The ACC and vaterite are stabler in air than in solutions at room temperature, although the dissolution-recrystallisation reaction occurs on the surface.展开更多
Electrocatalytic reduction of CO_(2)(CO_(2)RR)to multicarbon products is an efficient approach for ad-dressing the energy crisis and achieving carbon neutrality.In H-cells,achieving high-current C_(2)products is chall...Electrocatalytic reduction of CO_(2)(CO_(2)RR)to multicarbon products is an efficient approach for ad-dressing the energy crisis and achieving carbon neutrality.In H-cells,achieving high-current C_(2)products is challenging because of the inefficient mass transfer of the catalyst and the presence of the hydrogen evolution reaction(HER).In this study,dendritic Cu/Cu_(2)O with abundant Cu^(0)/Cu^(+)interfaces and numerous dendritic curves was synthesized in a CO_(2)atmosphere,resulting in the high selectivity and current density of the C_(2)products.Dendritic Cu/Cu_(2)O achieved a C_(2)Faradaic efficiency of 69.8%and a C_(2)partial current density of 129.5 mA cm^(-2)in an H-cell.Finite element simulations showed that a dendritic structure with a high curvature generates a strong electric field,leading to a localized CO_(2)concentration.Additionally,DRT analysis showed that a dendritic struc-ture with a high curvature actively adsorbed the surrounding high concentration of CO_(2),enhancing the mass transfer rate and achieving a high current density.During the experiment,the impact of the electronic structure on the performance of the catalyst was investigated by varying the atomic ratio of Cu^(0)/Cu^(+) on the catalyst surface,which resulted in improved ethylene selectivity.Under the optimal atomic ratio of Cu^(0)/Cu^(+),the charge transfer resistance was minimized,and the desorption rate of the intermediates was low,favoring C_(2) generation.Density functional theory calculations indicated that the Cu^(0)/Cu^(+) interfaces exhibited a lower Gibbs free energy for the rate-determining step,enhancing C_(2)H_(4) formation.The Cu/Cu_(2)O catalyst also exhibited a low Cu d-band center,which enhanced the adsorption stability of *CO on the surface and facilitated C_(2)formation.This observa-tion explained the higher yield of C_(2) products at the Cu^(0)/Cu^(+) interface than that of H_(2) under rapid mass transfer.The results of the net present value model showed that the H-cell holds promising industrial prospects,contingent upon it being a catalyst with both high selectivity and high current density.This approach of integrating the structure and composition provides new insights for ad-vancing the CO_(2)RR towards high-current C_(2) products.展开更多
This study was conducted to compare leaf anatomical structures and ap- parent plant print characteristics of 3 Vicia plants from Changbai Mountains applying structural botany principle and fingerprint identification t...This study was conducted to compare leaf anatomical structures and ap- parent plant print characteristics of 3 Vicia plants from Changbai Mountains applying structural botany principle and fingerprint identification technology, aiming at dis- cussing the structure evolution law of Vicia plants and providing scientific reference for research about classification, genetic relationship and evolutionary trend of this genus. The comparison of leaf anatomical structures of Vicia lilacina, V. pseu- dorobus and V. unijuga showed that： V. unijuga has tidily arranged leaf epidermal cells, thickened outer tangential wall cuticle, large diameter of xylem vessels, and developed midrib fibrocytes which form vascular bundle sheaths. Plant print identifi- cation results showed that the tested 3 plants showed remarkable differences in leaf apparent texture and anticlinal wall type though plant print characteristics of appar- ent structures of plants in the same genus had homologous similarity. V. lilacina has no subsidiary cells, and apparent textures of V. pseudorobus and V. unijuga are both of paracytic unequal type. Statistical analysis showed that V. unijuga is more advanced than V. pseudorobus. The 3 tested plants are in evolutionary rela- tionship of V. lilacina〈V, pseudorobus〈V, unijuga.展开更多
The growth and development of staminate inflorescence and anatomic structure of male chestnut flower were observed. Results showed that staminate in-florescence on the base of branch formed first, then upward successi...The growth and development of staminate inflorescence and anatomic structure of male chestnut flower were observed. Results showed that staminate in-florescence on the base of branch formed first, then upward successively. About 50 days were needed from the formation of staminate inflorescence on the base of branch to ful y develop the staminate inflorescence on the top of the branch. On the same staminate inflorescence, male flower clusters of the base formed first, then upward successively. About 20 days were needed from the formation of stami-nate inflorescence on the base of the male flower cluster to ful y develop the stami-nate inflorescence on the top of the branch. 5-7 male flowers forming a cluster, the flower number in a cluster was odd number usual y, and there was one on the top and each two paral el y arranged downward. The flower on the top came into bloom first, and then downward successively. The flowers paral el y arranged came into bloom at the same time. Sporangium of male flower of chestnut was monolocular. There were a large number of pol en grains in the sporangium. There were large differences between the development process of different sporangium in one male flower. Chestnut had larger quantity of male flowers and pol en and long period of pol ination compared with female flower. It is remained to be further studied whether it was necessary for anemophilous pol ination.展开更多
[Objective] The aim was to study the effect of tomato yellow leaf curl virus （TYLCV） infection on leaf anatomical structure and protective enzyme system of tomato. [Method] The anatomical structure of infected and h...[Objective] The aim was to study the effect of tomato yellow leaf curl virus （TYLCV） infection on leaf anatomical structure and protective enzyme system of tomato. [Method] The anatomical structure of infected and healthy leaves of tomato were observed and compared by using paraffin section method. The activity changes of SOD, POD and CAT in the infected leaves of tomato were determined. [ Result] The results revealed that there were some differences in anatomical structure between healthy and infected leaves. Some cells of infected leaves were damaged so that the leaves curled and became yellow, which affected the normal function of organs. Compared with control, enzyme activities in the tomato plants infected by TYLCV were enhanced at the early periods and higher than that in control, then started to decline at the middle and late periods but lower than that in control.[ Conclusion] After infection by TYLCV, the leaf anatomical structure of tomato was changed greatly and the protective enzyme system was damaged severely, and affected the normal physJological metabolic functions of tissues and organs in tomato in further.展开更多
[Objective] This study was conducted to compare leaf anatomical structure of Malus sieversii and M. robusta under different salt concentration levels to determine their tolerance to salt and thus to provide rootstock ...[Objective] This study was conducted to compare leaf anatomical structure of Malus sieversii and M. robusta under different salt concentration levels to determine their tolerance to salt and thus to provide rootstock materials for apple production in salinized soil in Southern Xinjiang. [Method] The experiment was conducted with M. sieversii and M. robusta as test materials. Salt stress was simulated using 8 g/L of NaCI solution, and Hoagland nutrient solution was used instead of NaCI solution as control group （CK）. Samples were collected on the 20^th d of treatment, sliced through paraffin processing. The prepared paraffin sections of M. sieversii and M. robusta were then observed under a light microscope for anatomical structures of leaf, upper epidermis, lower epidermis, palisade tissue and spongy tissue. [Result] Compared with the control, the leaf, upper epidermis, lower epidermis and spongy tissue of M. sieversii and M. robusta under salt stress were thickened at different degrees, while the thickness of the palisade tissue was decreased. Moreover, high salt concentration caused severer damage to the cell structure of M. sieversii than to that of M. robusta, as M. robusta cells maintained better structural integrity. [Conclusion] M. robusta has higher adaptability to salt stress than M. sieversii.展开更多
A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution ...A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,X-ray photoelectron spectroscopy,and N2 adsorption-desorption were used to characterize the crystalline phase,morphology,particle size,chemical composition,and surface area of the WO3 samples.The formation of hexagonal（h-WO3） and monoclinic（m-WO3） crystal structures of WO3 at different temperatures or different times was confirmed by XRD.m-WO3 is formed at 600 ℃,while m-WO3 starts to transform into h-WO3 at 800℃.However,h-WO3,which forms at 800℃,may transform into m-WO3 by increasing the calcination temperature to 1000℃.SEM results indicate that m-WO3 particles exhibit a bulky shape with heavy aggregates,while h-WO3 particles exhibit a rod-like shape.Moreover,m-WO3 crystals are sporadically patched on the surface of the h-WO3 rod-like particles,resulting in the exposure of both m-WO3 and h-WO3 on the surface.It is observed that the monoclinic phase（m-WO3）/hexagonal phase（h-WO3） junction was fabricated by tuning the calcination temperature and calcination time.The relative ratios between m-WO3 and h-WO3 in the phase junction can readily be tailored by control of the calcination time.The photocatalytic activities of WO3 with different crystalline phases were evaluated by the photocatalytic degradation of rhodamine B as a model pollutant.A higher photocatalytic activity was observed in the WO3 sample with the m-WO3/h-WO3junction as compared with the sample with only m-WO3.The improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate owing to the formation of the phase junction,whose presence has been confirmed by HRTEM and photoluminescence spectra.展开更多
ZnO/Znml2O4 nanocomposites with heteronanostructures were successfully prepared by co-precipitation method. The as-prepared samples were characterized by HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. Th...ZnO/Znml2O4 nanocomposites with heteronanostructures were successfully prepared by co-precipitation method. The as-prepared samples were characterized by HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. The photoeatalytic activities of the as-prepared samples were evaluated by the photocatalytic degradation of methyl orange and inactivation of Escherichia coli in suspension under the irradiation of the simulated sunlight. The effects of compositions, calcination temperatures, concentration ofphotocatalysts and light source on the photocatalytic activities were systematically studied. The results show that when the concentration of ZnO/ZnA1204 photocatalyst with the starting Zn to Al molar ratio of 1：1.5 calcined at 600 ℃ is 1.0 g/L, the maximum photocatalytic degradation rate of 98.5% can be obtained in 50 min under the irradiation of the simulated sunlight. Under the same conditions, an inactivation rate of 99.8% for E.coli is achieved in 60 min.展开更多
The crystal structure, morphology, dissolution kinetics and mechanism of gibbsitic bauxite and pure gibbsite in Na OH solution under atmospheric pressure were systematically investigated by XRD and SEM. The results sh...The crystal structure, morphology, dissolution kinetics and mechanism of gibbsitic bauxite and pure gibbsite in Na OH solution under atmospheric pressure were systematically investigated by XRD and SEM. The results show that the size of single crystal of gibbsite in gibbsitic bauxite is smaller than that in pure gibbsite, but the interplanar distance is larger than that of pure gibbsite, which result in more defects in the crystal and less energy needed to dissolve in alkaline solution for the gibbsitic bauxite. The dissolution kinetic equations of gibbsitic bauxite and pure gibbsite were established, and the corresponding activation energies were calculated to be 99.144 and 115.149 k J/mol, respectively.展开更多
基金National Natural Science Foundation of China(22073030)the Oriental Scholars of Shanghai Universities。
文摘Dichloromethane(DCM)dehalogenase stands as a crucial enzyme implicated in the degradation of methylene chloride across diverse environmental and biological contexts.However,the unbinding pathways of ligands from DCM dehalogenase remain unexplored.In order to gain a deeper understanding of the binding sites and dissociation pathways of dichloromethane(DCM)and glutathione(GSH)from the DCM dehalogenase,random accelerated molecular dynamics(RAMD)simulations were performed,in which DCM and GSH were forced to leave the active site.The protein structure was predicted using Alphafold2,and the conformations of GSH and DCM in the binding pocket were predicted by docking.A long equilibrium simulation was conducted to validate the structure of the complex.The results show that GSH is most commonly observed in three main pathways,one of which is more important than the other two.In addition,DCM was observed to escape along a unique pathway.The key residues and protein helices of each pathway were identified.The results can provide a theoretical foundation for the subsequent dissociation mechanism of DCM dehalogenase.
基金financially supported by the National Natural Science Foundation of China(No.52074130)the Engineering Research Center of Resource Utilization of Carbon-containing Waste with Carbon Neutrality,Ministry of Education。
文摘Alkaline water electrolysis(AWE)is the most mature technology for hydrogen production by water electrolysis.Alkaline water electrolyzer consists of multiple electrolysis cells,and a single cell consists of a diaphragm,electrodes,bipolar plates and end plates,etc.The existing industrial bipolar plate channel is concave-convex structure,which is manufactured by complicated and high-cost mold punching.This structure still results in uneven electrolyte flow and low current density in the electrolytic cell,further increasing in energy consumption and cost of AWE.Thereby,in this article,the electrochemical and flow model is firstly constructed,based on the existing industrial concave and convex flow channel structure of bipolar plate,to study the current density,electrolyte flow and bubble distribution in the electrolysis cell.The reliability of the model was verified by comparison with experimental data in literature.Among which,the electrochemical current density affects the bubble yield,on the other hand,the generated bubbles cover the electrode surface,affecting the active specific surface area and ohmic resistance,which in turn affects the electrochemical reaction.The result indicates that the flow velocity near the bottom of the concave ball approaches zero,while the flow velocity on the convex ball surface is significantly higher.Additionally,vortices are observed within the flow channel structure,leading to an uneven distribution of electrolyte.Next,modelling is used to optimize the bipolar plate structure of AWE by simulating the electrochemistry and fluid flow performances of four kinds of structures,namely,concave and convex,rhombus,wedge and expanded mesh,in the bipolar plate of alkaline water electrolyzer.The results show that the expanded mesh channel structure has the largest current density of 3330 A/m^(2)and electrolyte flow velocity of 0.507 m/s in the electrolytic cell.Under the same current density,the electrolytic cell with the expanded mesh runner structure has the smallest potential and energy consumption.This work provides a useful guide for the comprehensive understanding and optimization of channel structures,and a theoretical basis for the design of large-scale electrolyzer.
基金supported by the National Natural Science Foundation of China(No.51972344)the Natural Science Foundation of Hunan Province,China(No.2018JJ3646).
文摘A series of Cr^(3+)-substituted Na_(1+x)Ti_(2−x)Cr_(x)P_(3)O_(12)(x=0.1,0.2,0.3,0.4,0.5,molar fraction)solid electrolytes were prepared by the solid-phase reaction method.The effects of Cr^(3+)ions on the phase composition,microstructure,and electrochemical ion conductivity of Na-based conductors were studied using X-ray powder diffraction,field emission scanning electron microscopy,and AC impedance measurement.The results show that the main crystal phase of NaTi_(2)(PO_(4))_(3) is formed in the solid electrolytes.The substitution of Ti4+sites by 15 at.%Cr^(3+)ions contributes to the enhancement of electrical conductivity,which is attributed to the combined effect of suppressing the formation of impurity phases,broadening ion channels,and improving the bonding degree of grains.Na_(1.3)Ti_(1.7)Cr_(0.3)P_(3)O_(12) electrolyte can obtain the best ionic conductivity of 6.13×10^(−6)S/cm at room temperature,which is 8 times that of the undoped NaTi_(2)(PO_(4))_(3) electrolyte.
基金financial support from the Natural Science Foundation of Hunan Province,China (No.2023JJ40759)the State Key Laboratory of Powder Metallurgy in Central South University,China。
文摘Ether-based solvents generally show better affinity for lithium metal,and thus ether-based electrolytes(EBEs)are more inclined to form a uniform and thin solid electrolyte interface(SEI),ensuring the long cycle stability of the lithium metal batteries(LMBs).Nonetheless,EBEs still face the challenge of oxidative decomposition under high voltage,which will corrode the structure of cathodes,destroy the stability of the electrode−electrolyte interface,and even cause safety risks.Herein,the types and challenges of EBEs are reviewed,the strategies for improving the high voltage stability of EBEs and constructing stable electrode−electrolyte interfaces are discussed in detail.Finally,the future perspectives and potential directions for composition optimization of EBEs and electrolyte−electrode interface regulation of high-voltage LMBs are explored.
基金financially supported from the National Natural Science Foundation of China(No.52201254)the Natural Science Foundation of Shandong Province,China(Nos.ZR2023ME155,ZR2020MB090,ZR2020QE012,ZR2020MB027)+1 种基金the Project of“20 Items of University”of Jinan,China(No.202228046)the Taishan Scholar Project of Shandong Province,China(No.tsqn202306226)。
文摘The development of efficient nonprecious bifunctional electrocatalysts for water electrolysis is crucial to enhance the sluggish kinetics of the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).A self-supporting,multiscale porous NiFeZn/NiZn-Ni catalyst with a triple interface heterojunction on nickel foam(NF)(NiFeZn/NiZn-Ni/NF)was in-situ fabricated using an electroplating-annealing-etching strategy.The unique multiinterface engineering and three-dimensional porous scaffold significantly modify the mass transport and electron interaction,resulting in superior bifunctional electrocatalytic performance for water splitting.The NiFeZn/NiZn-Ni/NF catalyst demonstrates low overpotentials of 187 m V for HER and 320 mV for OER at a current density of 600 mA/cm^(2),along with high durability over 150 h in alkaline solution.Furthermore,an electrolytic cell assembled with NiFeZn/NiZn-Ni/NF as both the cathode and anode achieves the current densities of 600 and 1000 m A/cm^(2) at cell voltages of 1.796 and 1.901 V,respectively,maintaining the high stability at 50 mA/cm^(2) for over 100 h.These findings highlight the potential of NiFeZn/NiZn-Ni/NF as a cost-effective and highly efficient bifunctional electrocatalyst for overall water splitting.
基金This work was supported by the Program for Changjiang Scholars and Innovative Research Team in University(No.IRTO453).
文摘A mutant with abnormal hull was first discovered from a twin-seedling strain W2555 in rice （Oryza sativa L.）. The mutant had sparse branches and decreased number of florets from the base to the peak. Frequently, the florets at the top of the panicle did not develop completely. The underdeveloped florets often showed slender and white in their life cycle. Genetic analysis indicated that the mutant traits were controlled by a single recessive gene （temporarily designated as ah）. ah gene controlled the development of inflorescence meristem and the flower organ. The florets of mutant showed degenerated lemma and palea. Stamens and lodicules were homeoticly transformed into pistils and palea/lemma-like structures, respectively. It seemed that ah mutant phenotypes of the homeotic conversions in lodicules and stamens were very similar to that of the B loss-of-function spwl gene reported previously in rice.
基金Supported by the Scientific Research Innovation Fund for the Youth of Hunan Academy of Forestry(2013LQJ13)~~
文摘Plants usually suffer drought stress during their growth process. As the photosynthetic activity center of plants, the leaf is the most sensitive organ under drought stress. In order to support the research on drought resistance of higher plants, this study reviewed the adaptation response and damage performance of epidermal structure, palisade tissue and spongy tissue, thickness, veins and stomata of plant leaves under drought stress.
文摘Using interface engineering,a highly efficient catalyst with a shell@core structure was successfully synthesized by growing an amorphous material composed of Ni,Mo,and P on Cu nanowires(Ni-MoP@CuNWs).This catalyst only requires an overpotential of 35 mV to reach a current density of 10 mA cm^(-2).The exceptional hydrogen evolution reaction(HER)activity is attributed to the unique amorphous rod-like nature of NiMoP@CuNWs,which possesses a special hydrophilic feature,en-hances mass transfer,promotes effective contact between the electrode and electrolyte solution,and exposes more active sites during the catalytic process.Density functional theory revealed that the introduction of Mo weakens the binding strength of the Ni site on the catalyst surface with the H atom and promotes the desorption process of the H_(2) product significantly.Owing to its facile syn-thesis,low cost,and high catalytic performance,this electrocatalyst is a promising option for com-mercial applications as a water electrolysis catalyst.
文摘Calcium carbonate was synthesized in a CaCl2/NaCO3 mixed solution by using ethylenediaminetetraacetic acid （EDTA） as an additive. The thermodynamics and kinetics analyses indicate that although the driving force of amorphous calcium carbonate （ACC） precipitation is always less than that of calcite and vaterite precipitation, the nucleation rate of ACC is greater than that of calcite and vaterite at the initial stage of the precipitation reaction. With the increasing incubation time, vaterite and calcite particles nucleate heterogeneously by using the as-formed particles as active sites. Scanning electron microscopy images indicate that the transformation mechanism of ACC and vaterite to calcite is the dissolution-recrystallisation reaction. The presence of EDTA not only improves the stabilities of ACC and vaterite, but also leads to forming enlongated, connected rhombohedral calcite crystals after incubation 7 days in solutions. The ACC and vaterite are stabler in air than in solutions at room temperature, although the dissolution-recrystallisation reaction occurs on the surface.
文摘Electrocatalytic reduction of CO_(2)(CO_(2)RR)to multicarbon products is an efficient approach for ad-dressing the energy crisis and achieving carbon neutrality.In H-cells,achieving high-current C_(2)products is challenging because of the inefficient mass transfer of the catalyst and the presence of the hydrogen evolution reaction(HER).In this study,dendritic Cu/Cu_(2)O with abundant Cu^(0)/Cu^(+)interfaces and numerous dendritic curves was synthesized in a CO_(2)atmosphere,resulting in the high selectivity and current density of the C_(2)products.Dendritic Cu/Cu_(2)O achieved a C_(2)Faradaic efficiency of 69.8%and a C_(2)partial current density of 129.5 mA cm^(-2)in an H-cell.Finite element simulations showed that a dendritic structure with a high curvature generates a strong electric field,leading to a localized CO_(2)concentration.Additionally,DRT analysis showed that a dendritic struc-ture with a high curvature actively adsorbed the surrounding high concentration of CO_(2),enhancing the mass transfer rate and achieving a high current density.During the experiment,the impact of the electronic structure on the performance of the catalyst was investigated by varying the atomic ratio of Cu^(0)/Cu^(+) on the catalyst surface,which resulted in improved ethylene selectivity.Under the optimal atomic ratio of Cu^(0)/Cu^(+),the charge transfer resistance was minimized,and the desorption rate of the intermediates was low,favoring C_(2) generation.Density functional theory calculations indicated that the Cu^(0)/Cu^(+) interfaces exhibited a lower Gibbs free energy for the rate-determining step,enhancing C_(2)H_(4) formation.The Cu/Cu_(2)O catalyst also exhibited a low Cu d-band center,which enhanced the adsorption stability of *CO on the surface and facilitated C_(2)formation.This observa-tion explained the higher yield of C_(2) products at the Cu^(0)/Cu^(+) interface than that of H_(2) under rapid mass transfer.The results of the net present value model showed that the H-cell holds promising industrial prospects,contingent upon it being a catalyst with both high selectivity and high current density.This approach of integrating the structure and composition provides new insights for ad-vancing the CO_(2)RR towards high-current C_(2) products.
基金Supported by Natural Science Foundation of China(41271231)~~
文摘This study was conducted to compare leaf anatomical structures and ap- parent plant print characteristics of 3 Vicia plants from Changbai Mountains applying structural botany principle and fingerprint identification technology, aiming at dis- cussing the structure evolution law of Vicia plants and providing scientific reference for research about classification, genetic relationship and evolutionary trend of this genus. The comparison of leaf anatomical structures of Vicia lilacina, V. pseu- dorobus and V. unijuga showed that： V. unijuga has tidily arranged leaf epidermal cells, thickened outer tangential wall cuticle, large diameter of xylem vessels, and developed midrib fibrocytes which form vascular bundle sheaths. Plant print identifi- cation results showed that the tested 3 plants showed remarkable differences in leaf apparent texture and anticlinal wall type though plant print characteristics of appar- ent structures of plants in the same genus had homologous similarity. V. lilacina has no subsidiary cells, and apparent textures of V. pseudorobus and V. unijuga are both of paracytic unequal type. Statistical analysis showed that V. unijuga is more advanced than V. pseudorobus. The 3 tested plants are in evolutionary rela- tionship of V. lilacina〈V, pseudorobus〈V, unijuga.
基金Supported by the Major Project of the Natural Science Foundation of Hubei Province(2010CBB03901)the Key Project of the Industry-University-Research Cooperation Program of the Education Department of Hubei Province(C2010060)+3 种基金the Demonstration Project of the Forestry Scientific and Technical Extension of the Central Finance in 2011(2011BH0032)the Open Fund Project of the Key Laboratory of Economic Forest Germplasm Improvement Resources Comprehensive Utilization of Hubei Province(2013000503)the Industry-University-Research Cooperation Program of Huanggang Normal University(2012025703)the Postdoctoral Fund of Jiangsu Province(1402115C)~~
文摘The growth and development of staminate inflorescence and anatomic structure of male chestnut flower were observed. Results showed that staminate in-florescence on the base of branch formed first, then upward successively. About 50 days were needed from the formation of staminate inflorescence on the base of branch to ful y develop the staminate inflorescence on the top of the branch. On the same staminate inflorescence, male flower clusters of the base formed first, then upward successively. About 20 days were needed from the formation of stami-nate inflorescence on the base of the male flower cluster to ful y develop the stami-nate inflorescence on the top of the branch. 5-7 male flowers forming a cluster, the flower number in a cluster was odd number usual y, and there was one on the top and each two paral el y arranged downward. The flower on the top came into bloom first, and then downward successively. The flowers paral el y arranged came into bloom at the same time. Sporangium of male flower of chestnut was monolocular. There were a large number of pol en grains in the sporangium. There were large differences between the development process of different sporangium in one male flower. Chestnut had larger quantity of male flowers and pol en and long period of pol ination compared with female flower. It is remained to be further studied whether it was necessary for anemophilous pol ination.
基金Supported by the National 863 Program:Gene Polymerization Tech-nology Study and New Variety Breeding of High-qualityMulti-resist-ance and High-yield Tomato(2007AA10Z178)+1 种基金Shanghai Agricul-ture Committee Key ProjectGermplasm Innovation of Tomato Re-sistance to Yellow Leaf Curl Virus(2007)~~
文摘[Objective] The aim was to study the effect of tomato yellow leaf curl virus （TYLCV） infection on leaf anatomical structure and protective enzyme system of tomato. [Method] The anatomical structure of infected and healthy leaves of tomato were observed and compared by using paraffin section method. The activity changes of SOD, POD and CAT in the infected leaves of tomato were determined. [ Result] The results revealed that there were some differences in anatomical structure between healthy and infected leaves. Some cells of infected leaves were damaged so that the leaves curled and became yellow, which affected the normal function of organs. Compared with control, enzyme activities in the tomato plants infected by TYLCV were enhanced at the early periods and higher than that in control, then started to decline at the middle and late periods but lower than that in control.[ Conclusion] After infection by TYLCV, the leaf anatomical structure of tomato was changed greatly and the protective enzyme system was damaged severely, and affected the normal physJological metabolic functions of tissues and organs in tomato in further.
文摘[Objective] This study was conducted to compare leaf anatomical structure of Malus sieversii and M. robusta under different salt concentration levels to determine their tolerance to salt and thus to provide rootstock materials for apple production in salinized soil in Southern Xinjiang. [Method] The experiment was conducted with M. sieversii and M. robusta as test materials. Salt stress was simulated using 8 g/L of NaCI solution, and Hoagland nutrient solution was used instead of NaCI solution as control group （CK）. Samples were collected on the 20^th d of treatment, sliced through paraffin processing. The prepared paraffin sections of M. sieversii and M. robusta were then observed under a light microscope for anatomical structures of leaf, upper epidermis, lower epidermis, palisade tissue and spongy tissue. [Result] Compared with the control, the leaf, upper epidermis, lower epidermis and spongy tissue of M. sieversii and M. robusta under salt stress were thickened at different degrees, while the thickness of the palisade tissue was decreased. Moreover, high salt concentration caused severer damage to the cell structure of M. sieversii than to that of M. robusta, as M. robusta cells maintained better structural integrity. [Conclusion] M. robusta has higher adaptability to salt stress than M. sieversii.
基金supported by the National Natural Science Foundation of China (21573101)the Liaoning Provincial Natural Science Foundation(2014020107)+2 种基金the Program for Liaoning Excellent Talents in University (LJQ2014041)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry ([2013]1792)the Opening Project of Key Laboratory of Photochemical Conversion and Optoelectronic Materials, TIPC, CAS,the Opening Project of State Key Laboratory of Catalysis, DICP, CAS (N-09-06)~~
文摘A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,X-ray photoelectron spectroscopy,and N2 adsorption-desorption were used to characterize the crystalline phase,morphology,particle size,chemical composition,and surface area of the WO3 samples.The formation of hexagonal（h-WO3） and monoclinic（m-WO3） crystal structures of WO3 at different temperatures or different times was confirmed by XRD.m-WO3 is formed at 600 ℃,while m-WO3 starts to transform into h-WO3 at 800℃.However,h-WO3,which forms at 800℃,may transform into m-WO3 by increasing the calcination temperature to 1000℃.SEM results indicate that m-WO3 particles exhibit a bulky shape with heavy aggregates,while h-WO3 particles exhibit a rod-like shape.Moreover,m-WO3 crystals are sporadically patched on the surface of the h-WO3 rod-like particles,resulting in the exposure of both m-WO3 and h-WO3 on the surface.It is observed that the monoclinic phase（m-WO3）/hexagonal phase（h-WO3） junction was fabricated by tuning the calcination temperature and calcination time.The relative ratios between m-WO3 and h-WO3 in the phase junction can readily be tailored by control of the calcination time.The photocatalytic activities of WO3 with different crystalline phases were evaluated by the photocatalytic degradation of rhodamine B as a model pollutant.A higher photocatalytic activity was observed in the WO3 sample with the m-WO3/h-WO3junction as compared with the sample with only m-WO3.The improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate owing to the formation of the phase junction,whose presence has been confirmed by HRTEM and photoluminescence spectra.
基金Project(21271071)supported by the National Natural Science Foundation of ChinaProject(21306041)supported by the National Natural Science Young Foundation of China
文摘ZnO/Znml2O4 nanocomposites with heteronanostructures were successfully prepared by co-precipitation method. The as-prepared samples were characterized by HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. The photoeatalytic activities of the as-prepared samples were evaluated by the photocatalytic degradation of methyl orange and inactivation of Escherichia coli in suspension under the irradiation of the simulated sunlight. The effects of compositions, calcination temperatures, concentration ofphotocatalysts and light source on the photocatalytic activities were systematically studied. The results show that when the concentration of ZnO/ZnA1204 photocatalyst with the starting Zn to Al molar ratio of 1：1.5 calcined at 600 ℃ is 1.0 g/L, the maximum photocatalytic degradation rate of 98.5% can be obtained in 50 min under the irradiation of the simulated sunlight. Under the same conditions, an inactivation rate of 99.8% for E.coli is achieved in 60 min.
基金Projects(5110404151174054+2 种基金51374065)supported by the National Natural Science Foundation of ChinaProject(N130402010)supported by the Fundamental Research Funds for the Central UniversitiesChina
文摘The crystal structure, morphology, dissolution kinetics and mechanism of gibbsitic bauxite and pure gibbsite in Na OH solution under atmospheric pressure were systematically investigated by XRD and SEM. The results show that the size of single crystal of gibbsite in gibbsitic bauxite is smaller than that in pure gibbsite, but the interplanar distance is larger than that of pure gibbsite, which result in more defects in the crystal and less energy needed to dissolve in alkaline solution for the gibbsitic bauxite. The dissolution kinetic equations of gibbsitic bauxite and pure gibbsite were established, and the corresponding activation energies were calculated to be 99.144 and 115.149 k J/mol, respectively.
