To investigate the roles of Harvista(a sprayable 1-methylcyclopropene,1-MCP,available component is 150 g·hm^(-2))and Ethephon(1 mL·L^(-1))applied at preharvest in apple(Malus domestica Borkh.'Golden Deli...To investigate the roles of Harvista(a sprayable 1-methylcyclopropene,1-MCP,available component is 150 g·hm^(-2))and Ethephon(1 mL·L^(-1))applied at preharvest in apple(Malus domestica Borkh.'Golden Delicious')fruit cuticular wax biosynthesis,the expression of genes related to fruit cuticular wax biosynthesis and ethylene biosynthesis and signaling,ethylene production rate,respiration rate,wax constituents and structure,and fruit quality were determined at harvest and during cold storage.The results showed that 1-MCP inhibited the expression levels of ethylene biosynthesis and signaling-related genes,decreased fruit ethylene production,and inhibited the expression of Md LACS1,Md CER6,Md CER4 and Md WSD1,which resulted in decreases in alcohols,acids,and esters content in fruit cuticular wax.1-MCP also reduced fruit dropping rate from 17.17%to 12%;maintained fruit firmness,soluble solids,titratable acidity during cold storage;showed about as one fifth in the total length and one third in the widest width of wax crack as that in control at harvest.In contrast,Ethephon produced the opposite effects.In conclusion,1-MCP inhibited fruit ethylene biosynthesis and signaling,and influenced fruit cuticular wax biosynthesis.Thus,the fruit cuticular wax constituents and structure was altered,and the fruit quality were maintained at harvest and during cold storage.The results provide a new technology for improving apple fruit harvest and postharvest quality by preharvest application of sprayable 1-MCP.展开更多
Anionic redox reaction(ARR) in layered manganese-based oxide cathodes has been considered as an effective strategy to improve the energy density of sodium-ion batteries.Mn-vacancy layered oxides deliver a high ARR-rel...Anionic redox reaction(ARR) in layered manganese-based oxide cathodes has been considered as an effective strategy to improve the energy density of sodium-ion batteries.Mn-vacancy layered oxides deliver a high ARR-related capacity with small voltage hysteresis,however,they are limited by rapid capacity degradation and poor rate capability,which arise from inferior structure changes due to repeated redox of lattice oxygen.Herein,redox-inactive Ti^(4+)is introduced to substitute partial Mn^(4+)to form Na_(2) Ti_(0.5)Mn_(2.5)O_7(Na_(4/7)[□_(1/7)Ti_(1/7)Mn_(5/7)]O_(2),□ for Mn vacancies),which can effectively restrain unfavorable interlayer gliding of Na2 Mn307 at high charge voltages,as reflected by an ultralow-strain volume variation of 0.11%.There is no irreversible O_(2) evolution observed in Na_(2) Ti_(0.5)Mn_(2.5)O_7 upon charging,which stabilizes the lattice oxygen and ensures the overall structural stability.It exhibits increased capacity retention of 79.1% after 60 cycles in Na_(2) Ti_(0.5)Mn_(2.5)O_7(17.1% in Na_(2) Mn_(3) O_7) and good rate capability(92.1 mAh g^(-1) at 0.5 A g^(-1)).This investigation provides new insights into designing high-performance cathode materials with reversible ARR and structural stability for SIBs.展开更多
Few-layered 2D analogs exhibit new physical/chemical properties,leading to a strong research interest and broad areas of application.Recently,lots of methods(such as ultrasonic and electrochemical methods)have already...Few-layered 2D analogs exhibit new physical/chemical properties,leading to a strong research interest and broad areas of application.Recently,lots of methods(such as ultrasonic and electrochemical methods)have already used to prepared 2D materials.However,these methods suffer from the drawbacks of low yield,high cost,or precarious state,which limit the largescale applications.Inspired by the famous Scotch tape method,we develop a ball-milling with polymer"tape"method,fabricating few-atomic-layered material,showing the high-yield,low-cost,and much stability.As electrode material,ultrathin 2D materials can shorten the ion transfer pathway,contributing to the development of high-power batteries.Meanwhile,fewatomic-layered structure can expose more active sites to increase their capacity,showing special energy storage mechanism.We use the as-prepared few-atomic-layered Bi(FALB)and reduced oxide graphene composites as the anode for potassium/sodium-ion batteries(KIBs/NIBs).The sample achieves a high reversible capacity of 395 m Ah g^(-1)for KIBs,of which FALB contributes 438 m Ah g^(-1)(higher than the theoretical capacity of Bi,386 m Ah g^(-1)),and it carries outstanding cycle and rate performance in KIBs/NIBs.展开更多
In recent years,with the increasing planting area of facility tomato,diseases and insect pests such as tomato grey mold(Botrytis cinerea),early blight(Alternaria solani),late blight(Phytophthora infestans),and whitefl...In recent years,with the increasing planting area of facility tomato,diseases and insect pests such as tomato grey mold(Botrytis cinerea),early blight(Alternaria solani),late blight(Phytophthora infestans),and whitefly(Trialeurodes uaporariorum) occur frequently,causing severe harms and difficulties in prevention and control.In order to ensure the normal production of facility tomato and improve the yield and quality of tomato,the corresponding prevention and control measures are put forward according to the regularity of the occurrence of diseases and insect pests and the characteristics of facility environment,which has certain guiding significance for agricultural production.展开更多
Methyl jasmonate(MeJA)has been shown to induce autophagy in various plant stress responses and metabolic pathways.MYC2 is involved in MeJA-mediated postharvest fruit biological metabolism,but it is unclear how it affe...Methyl jasmonate(MeJA)has been shown to induce autophagy in various plant stress responses and metabolic pathways.MYC2 is involved in MeJA-mediated postharvest fruit biological metabolism,but it is unclear how it affects MeJA-induced fruit autophagy.In this study,we noticed that silencing SlMYC2 significantly reduced the increase in autophagy-related genes(SlATGs)expression induced by MeJA.SlMYC2 could also bind to the promoters of several SlATGs,including SlATG13a,SlATG13b,SlATG18a,and SlATG18h,and activate their transcript levels.Moreover,SlMsrB5,a methionine sulfoxide reductase,could interact with SlMYC2.Methionine oxidation in SlMYC2 and mimicking sulfoxidation in SlMYC2 by mutation of methionine-542 to glutamine reduced the DNA-binding ability and transcriptional activity of SlMYC2,respectively.SlMsrB5 partially repaired oxidized SlMYC2 and restored its DNA-binding ability.On the other hand,silencing SlMsrB5 inhibited the transcript levels of SlMYC2-targeted genes(SlATG13a,SlATG13b,SlATG18a,and SlATG18h).Similarly,dual-luciferase reporter(DLR)analysis revealed that SlMsrB5–SlMYC2 interaction significantly increased the ability of SlMYC2-mediated transcriptional activation of SlATG13a,SlATG13b,SlATG18a,and SlATG18h.These findings demonstrate that SlMsrB5-mediated cyclic oxidation/reduction of methionine in SlMYC2 inf luences SlATGs expression.Collectively,these findings reveal the mechanism of SlMYC2 in SlATGs transcriptional regulation,providing insight into the mechanism of MeJA-mediated postharvest fruit quality regulation.展开更多
Objective: To construct the point mutation plasmids expressing HCV NS3/4A with different secondary structures at the N-terminus, and to analyze their serine protease activities. Methods: The point mutation plasmid c...Objective: To construct the point mutation plasmids expressing HCV NS3/4A with different secondary structures at the N-terminus, and to analyze their serine protease activities. Methods: The point mutation plasmid constructs were generated by using the QuickChange site-directed mutagenesis kit with the backbone of M-H05-5 (AI-1), and were named as subgroup A1-2, A2-1, A2-2, BI-1, B1-2, B2-1, and B2-2 respectively. The transient expression of the constructs was investigated by immunofluorescence assay and Western blot analysis. The difference in in cis and in trans NS3 serine protease activity between each subgroup was determined by Western blot analysis. Luciferase reporter assay was used to observe the inhibitory effects of the constructs on RIG-I induced IFN-β promoter activity and on p53-dependent transcriptional activation. Results: The point mutation plasmid constructs were verified for the correct sequence by DNA sequencing. The immunofluorescence assay revealed 4 subcellular localization patterns of NS3, including dot-like staining, diffuse staining, doughnut-like staining, and rod-shape staining. Western blot analysis indicated that the incomplete cleavage of NS3/4A appeared in subgroups A2-1 and B2-1, indicating that the in cis NS3 serine protease activities of subgroup A2-1 and B2-1 were weaker when compared with the other subgroups. By using NS5A/SBAC as a substrate for NS3/4A serine protease, it was also found that the in trans NS3 serine protease activities of subgroup A2-1 and B2-1 were also weaker compared the other subgroups. Differences in inhibitory effects of HCV NS3 on RIG-I induced IFN-β promoter activity and on p53-dependent transcriptional activation were also observed between subgroup A2-1, B2-1 and the other subgroups. Conclusion: The results suggest that subgroup A2-1 and B2-1 has weaker serine protease activities and weaker inhibitory activities on host cell functions than the other subgroups, which might be explained by the different secondary structure of the 120-aa sequence at N-terminus of NS3.展开更多
Lithium metal batteries(LMBs)have gained increasing attention owing to high energy density for large-scale energy storage applications.However,serious side reactions between Li anodes and organic electrolytes lead to ...Lithium metal batteries(LMBs)have gained increasing attention owing to high energy density for large-scale energy storage applications.However,serious side reactions between Li anodes and organic electrolytes lead to low Columbic efficiency and Li dendrites.Although progress has been achieved in constructing electrode structures,the interfacial instability of Li anodes is still challenging.Solvation chemistry significantly affects the electrolyte properties and interfacial reactions,but the reaction mechanisms and the roles of each component in electrolytes are still vague.This review spotlights the recent development of electrolyte regulation with concentration and composition adjustments,aiming to understanding the correlation between solvation structures and Li anode stability.Further perspectives on the solvation design are provided in light of anode interfacial stability in LMBs.展开更多
Organic materials with redox-active centers are regarded as promising candidates for rechargeable batteries in recent years for their light weight, low cost, environmental friendliness and structural diversity [1–4]....Organic materials with redox-active centers are regarded as promising candidates for rechargeable batteries in recent years for their light weight, low cost, environmental friendliness and structural diversity [1–4]. Organic materials, such as conducting polymers (polyacetylene, polypyrrole, polyaniline, etc.)[5], conjugated carbonyl compounds (quinone compounds, imides, etc.)[6–9] and nitroxide radical (N-O.)[10,11] compounds have been attempted as cathode materials in lithium-ion batteries (LIBs).展开更多
Wheat crown rot was first found in Weifang City in 2015,and now has become a major disease of wheat,showing an aggravating trend year by year.The author investigated the occurrence area and characteristics of wheat cr...Wheat crown rot was first found in Weifang City in 2015,and now has become a major disease of wheat,showing an aggravating trend year by year.The author investigated the occurrence area and characteristics of wheat crown rot in Weifang City over the past 5 years,and analyzed the causes of the disease.The disease was mainly related to variety resistance and farming system.According to the occurrence regularity of the disease,a set of comprehensive control measures were put forward.展开更多
[Objective]The paper was to monitor the occurrence dynamics of Agrotis ypsilon in Weifang and to clarify its occurrence regularity.[Method]High-altitude trap lamp and ground trap lamp were used to trap insects respect...[Objective]The paper was to monitor the occurrence dynamics of Agrotis ypsilon in Weifang and to clarify its occurrence regularity.[Method]High-altitude trap lamp and ground trap lamp were used to trap insects respectively.The lamps were automatically turned on at 19:00 every day,and monitored for 12 h until 7:00 am.The species of insects trapped by lamps was recorded every day,and the number of each species was counted.[Result]The peak periods of A.ypsilon caught by high-altitude trap lamp were basically consistent with those caught by ground trap lamp,indicating that A.ypsilon was more likely to immigrate from local area of Weifang.[Conclusion]The study provides theoretical support for migration prediction and early warning of A.ypsilon in Weifang.展开更多
Layered lithium transition metal oxide(LTMO)cathode materials have attracted much attention for lithium-ion batteries and are shining in the current market.Establishing a clear structure-performance relationship is ne...Layered lithium transition metal oxide(LTMO)cathode materials have attracted much attention for lithium-ion batteries and are shining in the current market.Establishing a clear structure-performance relationship is necessary for the performance improvement of LTMO cathode materials.The combination of synchrotron X-ray diffraction(XRD)with high intensity and XRD Rietveld refinement is powerful for revealing the structural characteristics of LTMO cathode materials.This review summarizes the application of high energy XRD and Rietveld refinement in LTMO cathode materials,including the brief introduction of synchrotron XRD and Rietveld refinement and their applications in understanding the structural evolution related to the synthetic,thermal runaway,cycling,and high-rate charge/discharge process of LTMO cathode materials.Synchrotron XRD can provide insights into the intermediates and reaction paths in the synthesis process,the origin of thermal runaway,the mechanism of structural decay during cycles,and the structural evolution during high-rate charging/discharging.Future works should focus on the development of higher intensity X-rays to gain more in-depth insights into the intrinsic relationship between their structural characteristics and properties.展开更多
Na-O_(2) and K-O_(2) batteries have attracted extensive attention in recent years.However,the parasitic reactions involving the discharge product of NaO_(2) or K anode with electrolytes and the severe Na or K dendrite...Na-O_(2) and K-O_(2) batteries have attracted extensive attention in recent years.However,the parasitic reactions involving the discharge product of NaO_(2) or K anode with electrolytes and the severe Na or K dendrites plague their rechargeability and cycle stability.Herein,we report a hybrid Na//K^(+)-containing electrolyte//O_(2) battery consisting of a Na anode,1.0 M of potassium trifate in diglyme,and a porous carbon cathode.Upon discharging,KO_(2) is preferentially produced via oxygen reduction in the cathode with Na+stripped from the Na anode,and reversely,the KO_(2) is electrochemically decomposed with Na+plated back onto the anode.Te new reaction pathway can circumvent the parasitic reactions involving instable NaO_(2) and active K anode,and alternatively,the good stability and conductivity of KO_(2) and stable Na stripping/plating in the presence of K^(+) enable the hybrid battery to exhibit an average discharge/charge voltage gap of 0.15 V,high Coulombic efciency of>96%,and superior cycling stability of 120 cycles.Tis will pave a new pathway to promote metal-air batteries.展开更多
石墨负极有望应用于钾离子电池,但受到循环过程中不可控的体积波动和枝晶生长的限制.在此,我们利用酰胺基电解质构建了具有高机械强度和离子电导率的阴离子衍生界面,可有效解决这些问题.酰胺分子的高供体数可以加强溶剂分子与K+的溶剂...石墨负极有望应用于钾离子电池,但受到循环过程中不可控的体积波动和枝晶生长的限制.在此,我们利用酰胺基电解质构建了具有高机械强度和离子电导率的阴离子衍生界面,可有效解决这些问题.酰胺分子的高供体数可以加强溶剂分子与K+的溶剂化作用,确保更多的阴离子进入初级溶剂化鞘层.缩短的溶剂与阴离子距离有利于电子从溶剂化的K+转移到阴离子,进而促进阴离子还原.生成的富含无机物的界面缓冲了充放电过程中的体积变化,抑制了K枝晶的生成,促进了钾离子的扩散.基于此,K//K对称电池以0.15 V的极化电位稳定循环超过2800 h.石墨电极实现了C?KC60?KC48?KC36?KC_(2)4?KC8的高度可逆相变,在循环100周后仍保持了217.6 mA h g-1的高放电容量和86.9%的容量保持率.组装的全电池也表现出52.5 W h kg-1的高能量密度.这项工作突出了界面结构的重要性,并为设计高性能电解质提供了全新策略.展开更多
Comprehensive Summary Layered transition-metal oxides are promising cathode candidates for sodium-ion batteries.However,the inferior interphase formation and particulate fracture during sodiation/desodiation result in...Comprehensive Summary Layered transition-metal oxides are promising cathode candidates for sodium-ion batteries.However,the inferior interphase formation and particulate fracture during sodiation/desodiation result in structure degradation and poor stability.Herein,the interface chemistry of P2-Na_(0.640)Ni_(0.343)Mn_(0.657)O_(2)in an electrolyte of 1.0 mol/L NaPF6 in diglyme is unveiled to enable highly reversible Na extraction and intercalation.The uniform and robust cathode-electrolyte interphase layer is in situ formed with decomposition of diglyme molecules and anions in initial cycles.The NaF-and CO-rich CEI film exhibits high mechanical strength and ionic conductivity,which suppresses the reconstruction of its electrode interphase from P2 phase to spinel-like structure and reinforces its structure integrity without cracks.This favours facile Na+transport and stable bulk redox reactions.It is demonstrated to show long cycling stability with capacity retention of 94.4%for 180 cycles and superior rate capability.This investigation highlights the cathode interphase chemistry in sodium-ion batteries.展开更多
Sodium-ion batteries(SIBs) have been considered as promising candidates for large-scale energy storage, owing to the high abundance and low cost of sodium(Na) resources. However, the development of full SIB has been h...Sodium-ion batteries(SIBs) have been considered as promising candidates for large-scale energy storage, owing to the high abundance and low cost of sodium(Na) resources. However, the development of full SIB has been hindered by low energy density because of the sluggish kinetics of large Na^+. Here, we report a full SIB with commercial tin(Sn) anode, cross-linked Na_3V_2(PO_4)_3/carbon nanotubes composites(NVP-CNT) cathode, and ether-based electrolyte. Sn is capable of delivering high reversible capacity via formation of Na15 Sn4 and stable solid-electrolyte interface(SEI) in initial cycles. Meanwhile, the NASICON-type NVP enables ultrafast and stable Na^+intercalation/extraction, and the incorporation of CNT can improve its electrical conductivity. The assembled full SIB delivers high output voltage of ~3.2 V, high energy density of 253.4 W h kg^(-1) at1600 W kg^(-1) based on total mass of both cathode and anode, and remarkable capacity retention of 96.1% after 180 cycles. These merit construction of high-energy full SIBs and will promote the development of SIBs.展开更多
We report the synthesis and electrochemical sodium storage of cobalt disulfide (COS2) with various micro/nano-structures. CoS2 with microscale sizes are either assembled by nanoparticles (P-CoS2) via a facile solv...We report the synthesis and electrochemical sodium storage of cobalt disulfide (COS2) with various micro/nano-structures. CoS2 with microscale sizes are either assembled by nanoparticles (P-CoS2) via a facile solvothermal route or nano- octahedrons constructed solid (O-COS2) and hollow microstructures (H-CoS2) fabricated by hydrothermal methods. Among three morphologies, H-CoS2 exhibits the largest discharge capacities and best rate performance as anode of sodium-ion batteries (SIBs). Furthermore, H-CoS2 delivers a capacity of 690 mA.h.g 1 at 1 A·g 1 after 100 cycles in a potential range of 0.1-3.0 V, and N240 mA.h.g-1 over 800 cycles in the potential window of 1.0-3.0 V. This cycling difference mainly lies in the two discharge plateaus observed in 0.1-3.0 V and one discharge plateau in 1.0-3.0 V. To interpret the reactions, X-ray diffraction (XRD) and transmission electron microscopy (TEM) are applied. The results show that at the first plateau around 1.4 V, the insertion reaction (COS2 + xNa* + xe NaxCoS2) Occurs; while at the second plateau around 0.6 V, the conversion reaction (NaxCoS2 + (4 - x) Na+ + (4 - x)e -~ Co + 2Na2S) takes place. This provides insights for electrochemical sodium storage of CoS2 as the anode of SIBs.展开更多
Transition metal dichalcogenide nanodots (NDs) have received considerable interest. We report a facile bottom-up synthetic route for MoS2 NDs by using molybdenum pentachloride and L-cysteine as precursors in oleylam...Transition metal dichalcogenide nanodots (NDs) have received considerable interest. We report a facile bottom-up synthetic route for MoS2 NDs by using molybdenum pentachloride and L-cysteine as precursors in oleylamine. The synthesis of NDs with a narrow size distribution ranging from 2.2 to 5.3 nm, was tailored by controlling the reaction time. Because of its coating characteristics, oleyalmine leads to uniformity and monodispersity of the NDs. Moreover, the NDs synthesized have large specific surface areas providing active sites. Graphene possesses outstanding conductivity. Combining the advantages of the two materials, the 0D/2D material exhibits superior electrochemical performance because of the 2D permeable channels for ion adsorption, energy storage, and conversion. The as-prepared MoS2/rGO (-2.2 nm) showed a stable capacity of 220 mAh.g-1 after 10,000 cycles at the current density of 20 A.g-1. Furthermore, a reversible capacity -140 mAh·g-1 was obtained at a much higher current density of 40 A.g-L Additionally, this composite exhibited superior catalytic performance evidenced by a small overpotential (222 mV) to afford 10 mA.cm-2, and a small Tafel slope (59.8 mV-decade-1) with good acid-stability. The facile approach may pave the way for the preparation of NDs with these nanostructures for numerous applications.展开更多
A combined hot-injection and heat-up method was developed to synthesize monodisperse and uniform CoMn2O4 quantum dots (CMO QDs).CMO QDs with average size of 2.0,3.9,and 5.4 nm were selectively obtained at 80,90,and ...A combined hot-injection and heat-up method was developed to synthesize monodisperse and uniform CoMn2O4 quantum dots (CMO QDs).CMO QDs with average size of 2.0,3.9,and 5.4 nm were selectively obtained at 80,90,and 105 ℃,respectively.The CMO QDs supported on carbon nanotubes (CNTs) were employed as catalysts for the oxygen reduction/evolution reaction (ORR/OER) in alkaline solution to investigate their size-performance relationship.The results revealed that the amount of surface-adsorbed oxygen and the band gap energy,which affect the charge transfer in the oxygen electrocatalysis processes,strongly depend on the size of the CMO QDs.The CMO-3.9/CNT hybrid,consisting of CNT-supported CMO QDs of 3.9 nm size,possesses a moderate amount of surfaceadsorbed oxygen,a lower band gap energy,and a larger charge carrier concentration,and exhibits the highest electrocatalytic activity among the hybrid materials investigated.Moreover,the CMO-3.9/CNT hybrid displays ORR and OER performances similar to those of the benchmark Pt/C and RuO2 catalysts,respectively,due to the strong carbon-oxide interactions and the high dispersion of CoMn2O4 QDs on the carbon substrate;this reveals the huge potential of the CMO-3.9/CNT hybrid as a bifunctional OER/ORR electrocatalyst.The present results highlight the importance of controlling the size of metal oxide nanodots in the design of active oxygen electrocatalysts based on spinel-type,nonprecious metal oxides.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.31772024)。
文摘To investigate the roles of Harvista(a sprayable 1-methylcyclopropene,1-MCP,available component is 150 g·hm^(-2))and Ethephon(1 mL·L^(-1))applied at preharvest in apple(Malus domestica Borkh.'Golden Delicious')fruit cuticular wax biosynthesis,the expression of genes related to fruit cuticular wax biosynthesis and ethylene biosynthesis and signaling,ethylene production rate,respiration rate,wax constituents and structure,and fruit quality were determined at harvest and during cold storage.The results showed that 1-MCP inhibited the expression levels of ethylene biosynthesis and signaling-related genes,decreased fruit ethylene production,and inhibited the expression of Md LACS1,Md CER6,Md CER4 and Md WSD1,which resulted in decreases in alcohols,acids,and esters content in fruit cuticular wax.1-MCP also reduced fruit dropping rate from 17.17%to 12%;maintained fruit firmness,soluble solids,titratable acidity during cold storage;showed about as one fifth in the total length and one third in the widest width of wax crack as that in control at harvest.In contrast,Ethephon produced the opposite effects.In conclusion,1-MCP inhibited fruit ethylene biosynthesis and signaling,and influenced fruit cuticular wax biosynthesis.Thus,the fruit cuticular wax constituents and structure was altered,and the fruit quality were maintained at harvest and during cold storage.The results provide a new technology for improving apple fruit harvest and postharvest quality by preharvest application of sprayable 1-MCP.
基金Financial supports from the National Natural Science Foundation of China (21822506 and 51761165025)the Tianjin Natural Science Foundation (19JCJQJC62400)the 111 project of B12015。
文摘Anionic redox reaction(ARR) in layered manganese-based oxide cathodes has been considered as an effective strategy to improve the energy density of sodium-ion batteries.Mn-vacancy layered oxides deliver a high ARR-related capacity with small voltage hysteresis,however,they are limited by rapid capacity degradation and poor rate capability,which arise from inferior structure changes due to repeated redox of lattice oxygen.Herein,redox-inactive Ti^(4+)is introduced to substitute partial Mn^(4+)to form Na_(2) Ti_(0.5)Mn_(2.5)O_7(Na_(4/7)[□_(1/7)Ti_(1/7)Mn_(5/7)]O_(2),□ for Mn vacancies),which can effectively restrain unfavorable interlayer gliding of Na2 Mn307 at high charge voltages,as reflected by an ultralow-strain volume variation of 0.11%.There is no irreversible O_(2) evolution observed in Na_(2) Ti_(0.5)Mn_(2.5)O_7 upon charging,which stabilizes the lattice oxygen and ensures the overall structural stability.It exhibits increased capacity retention of 79.1% after 60 cycles in Na_(2) Ti_(0.5)Mn_(2.5)O_7(17.1% in Na_(2) Mn_(3) O_7) and good rate capability(92.1 mAh g^(-1) at 0.5 A g^(-1)).This investigation provides new insights into designing high-performance cathode materials with reversible ARR and structural stability for SIBs.
基金financially supported by the National Natural Science Foundation of China(51972258)the Fundamental Research Funds for the Central Universities(WUT:2019IVA007)
文摘Few-layered 2D analogs exhibit new physical/chemical properties,leading to a strong research interest and broad areas of application.Recently,lots of methods(such as ultrasonic and electrochemical methods)have already used to prepared 2D materials.However,these methods suffer from the drawbacks of low yield,high cost,or precarious state,which limit the largescale applications.Inspired by the famous Scotch tape method,we develop a ball-milling with polymer"tape"method,fabricating few-atomic-layered material,showing the high-yield,low-cost,and much stability.As electrode material,ultrathin 2D materials can shorten the ion transfer pathway,contributing to the development of high-power batteries.Meanwhile,fewatomic-layered structure can expose more active sites to increase their capacity,showing special energy storage mechanism.We use the as-prepared few-atomic-layered Bi(FALB)and reduced oxide graphene composites as the anode for potassium/sodium-ion batteries(KIBs/NIBs).The sample achieves a high reversible capacity of 395 m Ah g^(-1)for KIBs,of which FALB contributes 438 m Ah g^(-1)(higher than the theoretical capacity of Bi,386 m Ah g^(-1)),and it carries outstanding cycle and rate performance in KIBs/NIBs.
文摘In recent years,with the increasing planting area of facility tomato,diseases and insect pests such as tomato grey mold(Botrytis cinerea),early blight(Alternaria solani),late blight(Phytophthora infestans),and whitefly(Trialeurodes uaporariorum) occur frequently,causing severe harms and difficulties in prevention and control.In order to ensure the normal production of facility tomato and improve the yield and quality of tomato,the corresponding prevention and control measures are put forward according to the regularity of the occurrence of diseases and insect pests and the characteristics of facility environment,which has certain guiding significance for agricultural production.
基金supported by the National Natural Science Foundation of China(No.32172278)the Shandong Province Natural Science Foundation(ZR2020KC011).
文摘Methyl jasmonate(MeJA)has been shown to induce autophagy in various plant stress responses and metabolic pathways.MYC2 is involved in MeJA-mediated postharvest fruit biological metabolism,but it is unclear how it affects MeJA-induced fruit autophagy.In this study,we noticed that silencing SlMYC2 significantly reduced the increase in autophagy-related genes(SlATGs)expression induced by MeJA.SlMYC2 could also bind to the promoters of several SlATGs,including SlATG13a,SlATG13b,SlATG18a,and SlATG18h,and activate their transcript levels.Moreover,SlMsrB5,a methionine sulfoxide reductase,could interact with SlMYC2.Methionine oxidation in SlMYC2 and mimicking sulfoxidation in SlMYC2 by mutation of methionine-542 to glutamine reduced the DNA-binding ability and transcriptional activity of SlMYC2,respectively.SlMsrB5 partially repaired oxidized SlMYC2 and restored its DNA-binding ability.On the other hand,silencing SlMsrB5 inhibited the transcript levels of SlMYC2-targeted genes(SlATG13a,SlATG13b,SlATG18a,and SlATG18h).Similarly,dual-luciferase reporter(DLR)analysis revealed that SlMsrB5–SlMYC2 interaction significantly increased the ability of SlMYC2-mediated transcriptional activation of SlATG13a,SlATG13b,SlATG18a,and SlATG18h.These findings demonstrate that SlMsrB5-mediated cyclic oxidation/reduction of methionine in SlMYC2 inf luences SlATGs expression.Collectively,these findings reveal the mechanism of SlMYC2 in SlATGs transcriptional regulation,providing insight into the mechanism of MeJA-mediated postharvest fruit quality regulation.
基金supported by Japan China Sasakawa Medical Fellowship(2006-2007)
文摘Objective: To construct the point mutation plasmids expressing HCV NS3/4A with different secondary structures at the N-terminus, and to analyze their serine protease activities. Methods: The point mutation plasmid constructs were generated by using the QuickChange site-directed mutagenesis kit with the backbone of M-H05-5 (AI-1), and were named as subgroup A1-2, A2-1, A2-2, BI-1, B1-2, B2-1, and B2-2 respectively. The transient expression of the constructs was investigated by immunofluorescence assay and Western blot analysis. The difference in in cis and in trans NS3 serine protease activity between each subgroup was determined by Western blot analysis. Luciferase reporter assay was used to observe the inhibitory effects of the constructs on RIG-I induced IFN-β promoter activity and on p53-dependent transcriptional activation. Results: The point mutation plasmid constructs were verified for the correct sequence by DNA sequencing. The immunofluorescence assay revealed 4 subcellular localization patterns of NS3, including dot-like staining, diffuse staining, doughnut-like staining, and rod-shape staining. Western blot analysis indicated that the incomplete cleavage of NS3/4A appeared in subgroups A2-1 and B2-1, indicating that the in cis NS3 serine protease activities of subgroup A2-1 and B2-1 were weaker when compared with the other subgroups. By using NS5A/SBAC as a substrate for NS3/4A serine protease, it was also found that the in trans NS3 serine protease activities of subgroup A2-1 and B2-1 were also weaker compared the other subgroups. Differences in inhibitory effects of HCV NS3 on RIG-I induced IFN-β promoter activity and on p53-dependent transcriptional activation were also observed between subgroup A2-1, B2-1 and the other subgroups. Conclusion: The results suggest that subgroup A2-1 and B2-1 has weaker serine protease activities and weaker inhibitory activities on host cell functions than the other subgroups, which might be explained by the different secondary structure of the 120-aa sequence at N-terminus of NS3.
基金supported by the National Natural Science Foundation of China(No.52171215),the 111 project(No.B12015)Haihe Laboratory of Sustainable Chemical Transformations.
文摘Lithium metal batteries(LMBs)have gained increasing attention owing to high energy density for large-scale energy storage applications.However,serious side reactions between Li anodes and organic electrolytes lead to low Columbic efficiency and Li dendrites.Although progress has been achieved in constructing electrode structures,the interfacial instability of Li anodes is still challenging.Solvation chemistry significantly affects the electrolyte properties and interfacial reactions,but the reaction mechanisms and the roles of each component in electrolytes are still vague.This review spotlights the recent development of electrolyte regulation with concentration and composition adjustments,aiming to understanding the correlation between solvation structures and Li anode stability.Further perspectives on the solvation design are provided in light of anode interfacial stability in LMBs.
基金financially supported by the National Key R&D Program of China(2017YFA0206700)the National Natural Science Foundation of China(grant No.21822506&51671107)+1 种基金the 111 project of B12015the Natural Science Foundation of Tianjin(grant No.19JCJQJC62400)。
文摘Organic materials with redox-active centers are regarded as promising candidates for rechargeable batteries in recent years for their light weight, low cost, environmental friendliness and structural diversity [1–4]. Organic materials, such as conducting polymers (polyacetylene, polypyrrole, polyaniline, etc.)[5], conjugated carbonyl compounds (quinone compounds, imides, etc.)[6–9] and nitroxide radical (N-O.)[10,11] compounds have been attempted as cathode materials in lithium-ion batteries (LIBs).
基金Weifang Comprehensive Test Station of National Modern Industrial Technology SystemScience and Technology Innovation Project of Shandong Academy of Agricultural Sciences(CXGC2021A38)。
文摘Wheat crown rot was first found in Weifang City in 2015,and now has become a major disease of wheat,showing an aggravating trend year by year.The author investigated the occurrence area and characteristics of wheat crown rot in Weifang City over the past 5 years,and analyzed the causes of the disease.The disease was mainly related to variety resistance and farming system.According to the occurrence regularity of the disease,a set of comprehensive control measures were put forward.
基金Supported by Major Scientific and Technological Innovation Project (2020CXGC010802)。
文摘[Objective]The paper was to monitor the occurrence dynamics of Agrotis ypsilon in Weifang and to clarify its occurrence regularity.[Method]High-altitude trap lamp and ground trap lamp were used to trap insects respectively.The lamps were automatically turned on at 19:00 every day,and monitored for 12 h until 7:00 am.The species of insects trapped by lamps was recorded every day,and the number of each species was counted.[Result]The peak periods of A.ypsilon caught by high-altitude trap lamp were basically consistent with those caught by ground trap lamp,indicating that A.ypsilon was more likely to immigrate from local area of Weifang.[Conclusion]The study provides theoretical support for migration prediction and early warning of A.ypsilon in Weifang.
基金This work was supported by the National Natural Science Foundation of China(Nos.22121005,22020102002,and 21835004)the Frontiers Science Center for New Organic Matter of Nankai University(No.63181206).
文摘Layered lithium transition metal oxide(LTMO)cathode materials have attracted much attention for lithium-ion batteries and are shining in the current market.Establishing a clear structure-performance relationship is necessary for the performance improvement of LTMO cathode materials.The combination of synchrotron X-ray diffraction(XRD)with high intensity and XRD Rietveld refinement is powerful for revealing the structural characteristics of LTMO cathode materials.This review summarizes the application of high energy XRD and Rietveld refinement in LTMO cathode materials,including the brief introduction of synchrotron XRD and Rietveld refinement and their applications in understanding the structural evolution related to the synthetic,thermal runaway,cycling,and high-rate charge/discharge process of LTMO cathode materials.Synchrotron XRD can provide insights into the intermediates and reaction paths in the synthesis process,the origin of thermal runaway,the mechanism of structural decay during cycles,and the structural evolution during high-rate charging/discharging.Future works should focus on the development of higher intensity X-rays to gain more in-depth insights into the intrinsic relationship between their structural characteristics and properties.
基金Financial support from National Key R&D Program of China(2017YFA0206700)NSFC(grant No.21603108&51671107)+1 种基金National Natural Science Foundation of ChinaResearch Grants Council of Hong Kong joint project(NSFCRGC project of 51761165025)the 111 project of B12015 is acknowledged.
文摘Na-O_(2) and K-O_(2) batteries have attracted extensive attention in recent years.However,the parasitic reactions involving the discharge product of NaO_(2) or K anode with electrolytes and the severe Na or K dendrites plague their rechargeability and cycle stability.Herein,we report a hybrid Na//K^(+)-containing electrolyte//O_(2) battery consisting of a Na anode,1.0 M of potassium trifate in diglyme,and a porous carbon cathode.Upon discharging,KO_(2) is preferentially produced via oxygen reduction in the cathode with Na+stripped from the Na anode,and reversely,the KO_(2) is electrochemically decomposed with Na+plated back onto the anode.Te new reaction pathway can circumvent the parasitic reactions involving instable NaO_(2) and active K anode,and alternatively,the good stability and conductivity of KO_(2) and stable Na stripping/plating in the presence of K^(+) enable the hybrid battery to exhibit an average discharge/charge voltage gap of 0.15 V,high Coulombic efciency of>96%,and superior cycling stability of 120 cycles.Tis will pave a new pathway to promote metal-air batteries.
基金supported by the National Natural Science Foundation of China(22005082)the Natural Science Foundation of Hebei Province(B2020202065 and E2020202091)+4 种基金Hebei Province Education Department Science and Technology Research Project(QN2020209)the Special Project of Local Science and Technology Development Guided by the Central Government of China(226Z4402G)Shenzhen Science and Technology Program(KQTD20190929173815000)Guangdong Innovative and Entrepreneurial Research Team Program(2019ZT08C044)the Cryo-TEM Center at SUSTech CRF that receives support from the Presidential fund and Development and Reform Commission of Shenzhen Municipality.
文摘石墨负极有望应用于钾离子电池,但受到循环过程中不可控的体积波动和枝晶生长的限制.在此,我们利用酰胺基电解质构建了具有高机械强度和离子电导率的阴离子衍生界面,可有效解决这些问题.酰胺分子的高供体数可以加强溶剂分子与K+的溶剂化作用,确保更多的阴离子进入初级溶剂化鞘层.缩短的溶剂与阴离子距离有利于电子从溶剂化的K+转移到阴离子,进而促进阴离子还原.生成的富含无机物的界面缓冲了充放电过程中的体积变化,抑制了K枝晶的生成,促进了钾离子的扩散.基于此,K//K对称电池以0.15 V的极化电位稳定循环超过2800 h.石墨电极实现了C?KC60?KC48?KC36?KC_(2)4?KC8的高度可逆相变,在循环100周后仍保持了217.6 mA h g-1的高放电容量和86.9%的容量保持率.组装的全电池也表现出52.5 W h kg-1的高能量密度.这项工作突出了界面结构的重要性,并为设计高性能电解质提供了全新策略.
基金the National Natural Science Foundation of China(52171215)Haihe Laboratory of Sustainable Chemical Transformations,and China National Postdoctoral Program for Innovative Talents(BX2021024)。
文摘Comprehensive Summary Layered transition-metal oxides are promising cathode candidates for sodium-ion batteries.However,the inferior interphase formation and particulate fracture during sodiation/desodiation result in structure degradation and poor stability.Herein,the interface chemistry of P2-Na_(0.640)Ni_(0.343)Mn_(0.657)O_(2)in an electrolyte of 1.0 mol/L NaPF6 in diglyme is unveiled to enable highly reversible Na extraction and intercalation.The uniform and robust cathode-electrolyte interphase layer is in situ formed with decomposition of diglyme molecules and anions in initial cycles.The NaF-and CO-rich CEI film exhibits high mechanical strength and ionic conductivity,which suppresses the reconstruction of its electrode interphase from P2 phase to spinel-like structure and reinforces its structure integrity without cracks.This favours facile Na+transport and stable bulk redox reactions.It is demonstrated to show long cycling stability with capacity retention of 94.4%for 180 cycles and superior rate capability.This investigation highlights the cathode interphase chemistry in sodium-ion batteries.
基金supported by the Ministry of Science and Technology of China(2017YFA0206700)the National Natural Science Foundation of China(21822506,51671107)
文摘Sodium-ion batteries(SIBs) have been considered as promising candidates for large-scale energy storage, owing to the high abundance and low cost of sodium(Na) resources. However, the development of full SIB has been hindered by low energy density because of the sluggish kinetics of large Na^+. Here, we report a full SIB with commercial tin(Sn) anode, cross-linked Na_3V_2(PO_4)_3/carbon nanotubes composites(NVP-CNT) cathode, and ether-based electrolyte. Sn is capable of delivering high reversible capacity via formation of Na15 Sn4 and stable solid-electrolyte interface(SEI) in initial cycles. Meanwhile, the NASICON-type NVP enables ultrafast and stable Na^+intercalation/extraction, and the incorporation of CNT can improve its electrical conductivity. The assembled full SIB delivers high output voltage of ~3.2 V, high energy density of 253.4 W h kg^(-1) at1600 W kg^(-1) based on total mass of both cathode and anode, and remarkable capacity retention of 96.1% after 180 cycles. These merit construction of high-energy full SIBs and will promote the development of SIBs.
基金This work was supported by the National Natural Science Foundation of China (No. 51231003) and MOE (Nos. B12015 and IRT13R30).
文摘We report the synthesis and electrochemical sodium storage of cobalt disulfide (COS2) with various micro/nano-structures. CoS2 with microscale sizes are either assembled by nanoparticles (P-CoS2) via a facile solvothermal route or nano- octahedrons constructed solid (O-COS2) and hollow microstructures (H-CoS2) fabricated by hydrothermal methods. Among three morphologies, H-CoS2 exhibits the largest discharge capacities and best rate performance as anode of sodium-ion batteries (SIBs). Furthermore, H-CoS2 delivers a capacity of 690 mA.h.g 1 at 1 A·g 1 after 100 cycles in a potential range of 0.1-3.0 V, and N240 mA.h.g-1 over 800 cycles in the potential window of 1.0-3.0 V. This cycling difference mainly lies in the two discharge plateaus observed in 0.1-3.0 V and one discharge plateau in 1.0-3.0 V. To interpret the reactions, X-ray diffraction (XRD) and transmission electron microscopy (TEM) are applied. The results show that at the first plateau around 1.4 V, the insertion reaction (COS2 + xNa* + xe NaxCoS2) Occurs; while at the second plateau around 0.6 V, the conversion reaction (NaxCoS2 + (4 - x) Na+ + (4 - x)e -~ Co + 2Na2S) takes place. This provides insights for electrochemical sodium storage of CoS2 as the anode of SIBs.
基金This work was supported by the National Key R&D Program (No. 2016YFB0901502), National NaturalScience Foundation of China (Nos. 51231003, 51271094, and 21231005), Ministry of Education (Nos. B12015 and IRT13R30), and the Fundamental Research Funds for the Central Universities.
文摘Transition metal dichalcogenide nanodots (NDs) have received considerable interest. We report a facile bottom-up synthetic route for MoS2 NDs by using molybdenum pentachloride and L-cysteine as precursors in oleylamine. The synthesis of NDs with a narrow size distribution ranging from 2.2 to 5.3 nm, was tailored by controlling the reaction time. Because of its coating characteristics, oleyalmine leads to uniformity and monodispersity of the NDs. Moreover, the NDs synthesized have large specific surface areas providing active sites. Graphene possesses outstanding conductivity. Combining the advantages of the two materials, the 0D/2D material exhibits superior electrochemical performance because of the 2D permeable channels for ion adsorption, energy storage, and conversion. The as-prepared MoS2/rGO (-2.2 nm) showed a stable capacity of 220 mAh.g-1 after 10,000 cycles at the current density of 20 A.g-1. Furthermore, a reversible capacity -140 mAh·g-1 was obtained at a much higher current density of 40 A.g-L Additionally, this composite exhibited superior catalytic performance evidenced by a small overpotential (222 mV) to afford 10 mA.cm-2, and a small Tafel slope (59.8 mV-decade-1) with good acid-stability. The facile approach may pave the way for the preparation of NDs with these nanostructures for numerous applications.
基金This work was supported by the National Key Research and Development Program of China (Nos. 2016YFA0202500 and 2016YFB0101201), the National Natural Science Foundation of China (Nos. 21322101 and 21231005) and 111 Project (Nos. B12015 and IRT13R30).
文摘A combined hot-injection and heat-up method was developed to synthesize monodisperse and uniform CoMn2O4 quantum dots (CMO QDs).CMO QDs with average size of 2.0,3.9,and 5.4 nm were selectively obtained at 80,90,and 105 ℃,respectively.The CMO QDs supported on carbon nanotubes (CNTs) were employed as catalysts for the oxygen reduction/evolution reaction (ORR/OER) in alkaline solution to investigate their size-performance relationship.The results revealed that the amount of surface-adsorbed oxygen and the band gap energy,which affect the charge transfer in the oxygen electrocatalysis processes,strongly depend on the size of the CMO QDs.The CMO-3.9/CNT hybrid,consisting of CNT-supported CMO QDs of 3.9 nm size,possesses a moderate amount of surfaceadsorbed oxygen,a lower band gap energy,and a larger charge carrier concentration,and exhibits the highest electrocatalytic activity among the hybrid materials investigated.Moreover,the CMO-3.9/CNT hybrid displays ORR and OER performances similar to those of the benchmark Pt/C and RuO2 catalysts,respectively,due to the strong carbon-oxide interactions and the high dispersion of CoMn2O4 QDs on the carbon substrate;this reveals the huge potential of the CMO-3.9/CNT hybrid as a bifunctional OER/ORR electrocatalyst.The present results highlight the importance of controlling the size of metal oxide nanodots in the design of active oxygen electrocatalysts based on spinel-type,nonprecious metal oxides.