Lithium-sulfur batteries(LSBs)are considered promising candidates for next-generation battery technologies owing to their outstanding theoretical energy density and cost-effectiveness.However,the low conductivity and ...Lithium-sulfur batteries(LSBs)are considered promising candidates for next-generation battery technologies owing to their outstanding theoretical energy density and cost-effectiveness.However,the low conductivity and polysulfide shuttling effect of S cathodes severely hamper the practical performance of LSBs.Herein,in situ-generated single layer MXene nanosheet/hierarchical porous carbonized wood fiber(MX/PCWF)composites are prepared via a nonhazardous eutectic activation strategy coupled with pyrolysis-induced gas diffusion.The unique architecture,wherein single layer MXene nanosheets are constructed on carbonized wood fiber walls,ensures rapid polysulfide conversion and continuous electron transfer for redox reactions.The C-Ti-C bonds formed between MXene and PCWF can considerably expedite the conversion of polysulfides,effectively suppressing the shuttle effect.An impressive capacity of 1301.1 m A h g^(-1)at 0.5 C accompanied by remarkable stability is attained with the MX/PCWF host,as evidenced by the capacity maintenance of 722.6 m A h g^(-1)after 500 cycles.Notably,the MX/PCWF/S cathode can still deliver a high capacity of 886.8 m A h g^(-1)at a high S loading of 5.6 mg cm^(-2).The construction of two-dimensional MXenes on natural wood fiber walls offers a competitive edge over S-based cathode materials and demonstrates a novel strategy for developing high-performance batteries.展开更多
As a substitute for synthetic ammonia under mild condition, electrocatalytic nitrogen reduction reaction(NRR) provides a hopeful approach for the development of ammonia. Nevertheless, the current development of NRR el...As a substitute for synthetic ammonia under mild condition, electrocatalytic nitrogen reduction reaction(NRR) provides a hopeful approach for the development of ammonia. Nevertheless, the current development of NRR electrocatalysts is far from enough and a systematic research is needed to gain a better improvement. This article presents that 2 D C_(3)N_(4)-NV with a large specific surface area and abundant nitrogen vacancies is prepared by a simple and feasible method, and used as a metal-free catalyst for electrocatalytic NRR. Experiment result and density functional theory(DFT) calculation reveal that nitrogen vacancies in 2 D C_(3)N_(4)-NV can act as an efficient active site for catalytic NRR, which is conducive to capturing and activating N_(2), lowering Gibbs free energy(DG) in reaction and inhibiting hydrogen evolution reaction(HER) at the same time. In addition, the larger specific surface area also makes more active site exposed, which is good for the contact between the electrolyte and the active site, thus enhancing its NRR activity. The electrocatalyst shows an excellent catalytic activity for NRR in 0.1 M HCl, including Faradaic efficiency of 10.96%, NH_(3) yields of 17.85 lg h^(-1) mg_(cat)^(-1)., and good stability(over 20 h).展开更多
Tree peony(Paeonia suffruticosa Andr.)is a popular ornamental plant in China due to its showy and colorful flowers.However,yellow-colored flowers are rare in both wild species and domesticated cultivars.The molecular ...Tree peony(Paeonia suffruticosa Andr.)is a popular ornamental plant in China due to its showy and colorful flowers.However,yellow-colored flowers are rare in both wild species and domesticated cultivars.The molecular mechanisms underlying yellow pigmentation remain poorly understood.Here,petal tissues of two tree peony cultivars,“High Noon”(yellow flowers)and“Roufurong”(purple–red flowers),were sampled at five developmental stages(S1–S5)from early flower buds to full blooms.Five petal color indices(brightness,redness,yellowness,chroma,and hue angle)and the contents of ten different flavonoids were determined.Compared to“Roufurong,”which accumulated abundant anthocyanins at S3–S5,the yellow-colored“High Noon”displayed relatively higher contents of tetrahydroxychalcone(THC),flavones,and flavonols but no anthocyanin production.The contents of THC,flavones,and flavonols in“High Noon”peaked at S3 and dropped gradually as the flower bloomed,consistent with the color index patterns.Furthermore,RNA-seq analyses at S3 showed that structural genes such as PsC4Hs,PsDFRs,and PsUFGTs in the flavonoid biosynthesis pathway were downregulated in“High Noon,”whereas most PsFLSs,PsF3Hs,and PsF3’Hs were upregulated.Five transcription factor(TF)genes related to flavonoid biosynthesis were also upregulated in“High Noon.”One of these TFs,PsMYB111,was overexpressed in tobacco,which led to increased flavonols but decreased anthocyanins.Dual-luciferase assays further confirmed that PsMYB111 upregulated PsFLS.These results improve our understanding of yellow pigmentation in tree peony and provide a guide for future molecular-assisted breeding experiments in tree peony with novel flower colors.展开更多
Aqueous zinc metal batteries are considered as promising candidates for next-generation electrochemical energy storage devices,especially for large-scale energy storage,due to the advantages of high-safety,high energy...Aqueous zinc metal batteries are considered as promising candidates for next-generation electrochemical energy storage devices,especially for large-scale energy storage,due to the advantages of high-safety,high energy density and low cost.As the bridge connecting cathode and anode,electrolyte provides a realistic operating environment.In alkaline and neutral aqueous zinc metal batteries,issues associated with electrolyte and anode are still intractable.In this review,we reveal the development and evolution of electrolytes for aqueous zinc metal batteries from alkaline to neutral via the description of fundamentals and challenges in terms of comparison and connection.We also elaborate the strategies in electrolytes regulation and highlight the basic roles and progresses in additives engineering.展开更多
The hydrothermal/soft templating method is an effective way to synthesize ordered mesoporous carbon(OMC),yet the mechanism of this strategy is not well illustrated.Herein,a hydrothermal temperature-controlled approach...The hydrothermal/soft templating method is an effective way to synthesize ordered mesoporous carbon(OMC),yet the mechanism of this strategy is not well illustrated.Herein,a hydrothermal temperature-controlled approach is developed to precisely synthesize OMCs with well-defined morphologies from liquefied wood(LW).As the hydrothermal temperature increases from 130 to 210◦C,the hydrophilicity of the hydrophilic blocks decreases accompanied by the increase of the rel-ative volume of the hydrophobic block,resulting in the packing parameter p of micelles changing from p≤1/3 to 1/3<p<1/2,which transforms the micelle’s structure from spherical to cylindrical.Additionally,accelerated nucle-ation occurred with the increased hydrothermal temperature.When the rate of nucleation is matched to the self-assembly of the composite micelles,the compos-ite micelles grow into worm-like morphology and an ordered p6m mesostructure.This hydrothermal temperature-controlled strategy provides a straightforward and effective approach for synthesizing OMCs with various morphologies from LW,addressing the previously insufficiently elucidated micelle formation mechanism in the hydrothermal/soft templating method.展开更多
The influence of the wavelength dispersion on the temperature accuracy of the Raman distributed temperature sensor system （RDTS） is analyzed in detail, and a simple correction algorithm is proposed to compensate the...The influence of the wavelength dispersion on the temperature accuracy of the Raman distributed temperature sensor system （RDTS） is analyzed in detail, and a simple correction algorithm is proposed to compensate the fiber position error caused by the wavelength dispersion. The principle of the proposed algorithm is described theoretically, and the correction on each point along the entire fiber is realized. Temperature simulation results validate that the temperature distortion is corrected and the temperature accuracy is effectively improved from ＋5 ℃ to ±1 ℃.展开更多
Sedum alfredii Hance is a cadmium(Cd)/zinc(Zn)hyperaccumulator native to China.However,its relatively low biomass restricted the large-scale application for heavy metal contamination remediation.The chromosome set dou...Sedum alfredii Hance is a cadmium(Cd)/zinc(Zn)hyperaccumulator native to China.However,its relatively low biomass restricted the large-scale application for heavy metal contamination remediation.The chromosome set doubling of S.alfredii in vitro was achieved by 0.1%–0.2%(W/V)colchicine treatment.The plant DNA ploidy was analyzed by flow cytometry and chromosome set doubling plants(CSD)were identified based on the obvious different sharp peak.A tissue culture experiment with different Cd treated levels and a field trial with natural polluted mined soil were conducted to study the effects of chromosome doubling on plant biomass and Cd accumulation in shoots.The results suggested that S.alfredii is a mixoploid.Compared with the wild type plants(WT),CSD exhibited typical"gigas"characteristics in morphology including stem thickness,root hair production,number of leaves and size of stoma guard cell.Fresh weight and dry weight of CSD were increased to 1.62–2.03-fold and 2.26–3.25-fold of WT.And Cd content of CSD showed a17.49%–42.82%increase and 59%increase under tissue culture and field condition,accordingly.In addition,the TF and in BCF of CSD were 2.37-and 1.59-fold of WT,respectively.These results proved that it is feasible to promote phytoextraction efficiency of S.alfredii in Cd contaminated soils through chromosomal engineering,which provides a novel approach for hyperaccumulator application in phytoremediation.展开更多
The impact of microwave sweeper power fluctuation in the BOTDA system has been theoretically analyzed and experimentally tested. And a novel method comparing real-time acquisition of probe wave power with a new algori...The impact of microwave sweeper power fluctuation in the BOTDA system has been theoretically analyzed and experimentally tested. And a novel method comparing real-time acquisition of probe wave power with a new algorithm to realize probe wave power normalization for eliminating this impact was proposed. The principle of the proposed method was described theoretically. And the contrast test between our new method and conventional one was carried out. The experiment results indicated that the temperature accuracy was effectively improved from ＋5 C to 2 C.展开更多
To the Editor:Alveolar rhabdomyosarcoma(ARMS)of nasalwingwith distant metastasis has a very poor prognosis.Because it is difficult to achieve complete surgical excision of the primary site of the nasal wing,distant me...To the Editor:Alveolar rhabdomyosarcoma(ARMS)of nasalwingwith distant metastasis has a very poor prognosis.Because it is difficult to achieve complete surgical excision of the primary site of the nasal wing,distant metastasis is not easy to control.Here,we present an unusual case of a 29-month-old boy with ARMS in the left nasal wing accompanied by bone metastasis who was treated with systemic chemotherapy as well as 125I interstitial brachytherapy,and this special multidisciplinary management resulted in a perfect prognosis and mild long-term side effects.展开更多
基金financially supported by the National Natural Science Foundation of China(31890771)the Young Elite Scientists Sponsorship Program from the National Forestry and Grassland Administration of China(2019132614)+1 种基金the Science and Technology Innovation Program of Hunan Province(2022RC3054)the Hunan Provincial Innovation Foundation for Postgraduate(CX20230758)。
文摘Lithium-sulfur batteries(LSBs)are considered promising candidates for next-generation battery technologies owing to their outstanding theoretical energy density and cost-effectiveness.However,the low conductivity and polysulfide shuttling effect of S cathodes severely hamper the practical performance of LSBs.Herein,in situ-generated single layer MXene nanosheet/hierarchical porous carbonized wood fiber(MX/PCWF)composites are prepared via a nonhazardous eutectic activation strategy coupled with pyrolysis-induced gas diffusion.The unique architecture,wherein single layer MXene nanosheets are constructed on carbonized wood fiber walls,ensures rapid polysulfide conversion and continuous electron transfer for redox reactions.The C-Ti-C bonds formed between MXene and PCWF can considerably expedite the conversion of polysulfides,effectively suppressing the shuttle effect.An impressive capacity of 1301.1 m A h g^(-1)at 0.5 C accompanied by remarkable stability is attained with the MX/PCWF host,as evidenced by the capacity maintenance of 722.6 m A h g^(-1)after 500 cycles.Notably,the MX/PCWF/S cathode can still deliver a high capacity of 886.8 m A h g^(-1)at a high S loading of 5.6 mg cm^(-2).The construction of two-dimensional MXenes on natural wood fiber walls offers a competitive edge over S-based cathode materials and demonstrates a novel strategy for developing high-performance batteries.
基金funded by the National Natural Science Foundation of China (21802058 and 21872066)the Fundamental Research Funds for the Central Universities (China, lzujbky-2020-42)the Natural Science Foundation of Gansu Province (20JR5RA225)。
文摘As a substitute for synthetic ammonia under mild condition, electrocatalytic nitrogen reduction reaction(NRR) provides a hopeful approach for the development of ammonia. Nevertheless, the current development of NRR electrocatalysts is far from enough and a systematic research is needed to gain a better improvement. This article presents that 2 D C_(3)N_(4)-NV with a large specific surface area and abundant nitrogen vacancies is prepared by a simple and feasible method, and used as a metal-free catalyst for electrocatalytic NRR. Experiment result and density functional theory(DFT) calculation reveal that nitrogen vacancies in 2 D C_(3)N_(4)-NV can act as an efficient active site for catalytic NRR, which is conducive to capturing and activating N_(2), lowering Gibbs free energy(DG) in reaction and inhibiting hydrogen evolution reaction(HER) at the same time. In addition, the larger specific surface area also makes more active site exposed, which is good for the contact between the electrolyte and the active site, thus enhancing its NRR activity. The electrocatalyst shows an excellent catalytic activity for NRR in 0.1 M HCl, including Faradaic efficiency of 10.96%, NH_(3) yields of 17.85 lg h^(-1) mg_(cat)^(-1)., and good stability(over 20 h).
基金This research was supported by the National Key R&D Program of China(Grant number 2019YFD1001505)the National Natural Science Foundation of China(Grant number 31800599).
文摘Tree peony(Paeonia suffruticosa Andr.)is a popular ornamental plant in China due to its showy and colorful flowers.However,yellow-colored flowers are rare in both wild species and domesticated cultivars.The molecular mechanisms underlying yellow pigmentation remain poorly understood.Here,petal tissues of two tree peony cultivars,“High Noon”(yellow flowers)and“Roufurong”(purple–red flowers),were sampled at five developmental stages(S1–S5)from early flower buds to full blooms.Five petal color indices(brightness,redness,yellowness,chroma,and hue angle)and the contents of ten different flavonoids were determined.Compared to“Roufurong,”which accumulated abundant anthocyanins at S3–S5,the yellow-colored“High Noon”displayed relatively higher contents of tetrahydroxychalcone(THC),flavones,and flavonols but no anthocyanin production.The contents of THC,flavones,and flavonols in“High Noon”peaked at S3 and dropped gradually as the flower bloomed,consistent with the color index patterns.Furthermore,RNA-seq analyses at S3 showed that structural genes such as PsC4Hs,PsDFRs,and PsUFGTs in the flavonoid biosynthesis pathway were downregulated in“High Noon,”whereas most PsFLSs,PsF3Hs,and PsF3’Hs were upregulated.Five transcription factor(TF)genes related to flavonoid biosynthesis were also upregulated in“High Noon.”One of these TFs,PsMYB111,was overexpressed in tobacco,which led to increased flavonols but decreased anthocyanins.Dual-luciferase assays further confirmed that PsMYB111 upregulated PsFLS.These results improve our understanding of yellow pigmentation in tree peony and provide a guide for future molecular-assisted breeding experiments in tree peony with novel flower colors.
基金the Natural Science Foundation of Sichuan Province(No.2023NSFSC0116)the University of Electronic Science and Technology of China for startup funding(No.A1098531023601355).
文摘Aqueous zinc metal batteries are considered as promising candidates for next-generation electrochemical energy storage devices,especially for large-scale energy storage,due to the advantages of high-safety,high energy density and low cost.As the bridge connecting cathode and anode,electrolyte provides a realistic operating environment.In alkaline and neutral aqueous zinc metal batteries,issues associated with electrolyte and anode are still intractable.In this review,we reveal the development and evolution of electrolytes for aqueous zinc metal batteries from alkaline to neutral via the description of fundamentals and challenges in terms of comparison and connection.We also elaborate the strategies in electrolytes regulation and highlight the basic roles and progresses in additives engineering.
基金National Natural Science Foundation of China,Grant/Award Number:32371808Fundamental Research Funds for the Central Universities,Grant/Award Number:2572023CT06。
文摘The hydrothermal/soft templating method is an effective way to synthesize ordered mesoporous carbon(OMC),yet the mechanism of this strategy is not well illustrated.Herein,a hydrothermal temperature-controlled approach is developed to precisely synthesize OMCs with well-defined morphologies from liquefied wood(LW).As the hydrothermal temperature increases from 130 to 210◦C,the hydrophilicity of the hydrophilic blocks decreases accompanied by the increase of the rel-ative volume of the hydrophobic block,resulting in the packing parameter p of micelles changing from p≤1/3 to 1/3<p<1/2,which transforms the micelle’s structure from spherical to cylindrical.Additionally,accelerated nucle-ation occurred with the increased hydrothermal temperature.When the rate of nucleation is matched to the self-assembly of the composite micelles,the compos-ite micelles grow into worm-like morphology and an ordered p6m mesostructure.This hydrothermal temperature-controlled strategy provides a straightforward and effective approach for synthesizing OMCs with various morphologies from LW,addressing the previously insufficiently elucidated micelle formation mechanism in the hydrothermal/soft templating method.
基金This work was supported by Natural Science Foundation of China （60977058）, Science Fund for Distinguished Young Scholars of Shandong Province of China （JQ200819）, Independent Innovation Foundation of Shandong University （IIFSDU2010JC002＆2012JC015）, and promotive research fund for excellent young and middle-aged scientists of Shandong Province （BS2010DX028）.
文摘The influence of the wavelength dispersion on the temperature accuracy of the Raman distributed temperature sensor system （RDTS） is analyzed in detail, and a simple correction algorithm is proposed to compensate the fiber position error caused by the wavelength dispersion. The principle of the proposed algorithm is described theoretically, and the correction on each point along the entire fiber is realized. Temperature simulation results validate that the temperature distortion is corrected and the temperature accuracy is effectively improved from ＋5 ℃ to ±1 ℃.
基金supported by the National Key Research and Development Project of China (No. 2016YFD0800801)the National Natural Science Foundation of China (No. 41771345)the Fundamental Research Funds for the Central Universities (2019FZJD007)
文摘Sedum alfredii Hance is a cadmium(Cd)/zinc(Zn)hyperaccumulator native to China.However,its relatively low biomass restricted the large-scale application for heavy metal contamination remediation.The chromosome set doubling of S.alfredii in vitro was achieved by 0.1%–0.2%(W/V)colchicine treatment.The plant DNA ploidy was analyzed by flow cytometry and chromosome set doubling plants(CSD)were identified based on the obvious different sharp peak.A tissue culture experiment with different Cd treated levels and a field trial with natural polluted mined soil were conducted to study the effects of chromosome doubling on plant biomass and Cd accumulation in shoots.The results suggested that S.alfredii is a mixoploid.Compared with the wild type plants(WT),CSD exhibited typical"gigas"characteristics in morphology including stem thickness,root hair production,number of leaves and size of stoma guard cell.Fresh weight and dry weight of CSD were increased to 1.62–2.03-fold and 2.26–3.25-fold of WT.And Cd content of CSD showed a17.49%–42.82%increase and 59%increase under tissue culture and field condition,accordingly.In addition,the TF and in BCF of CSD were 2.37-and 1.59-fold of WT,respectively.These results proved that it is feasible to promote phytoextraction efficiency of S.alfredii in Cd contaminated soils through chromosomal engineering,which provides a novel approach for hyperaccumulator application in phytoremediation.
文摘The impact of microwave sweeper power fluctuation in the BOTDA system has been theoretically analyzed and experimentally tested. And a novel method comparing real-time acquisition of probe wave power with a new algorithm to realize probe wave power normalization for eliminating this impact was proposed. The principle of the proposed method was described theoretically. And the contrast test between our new method and conventional one was carried out. The experiment results indicated that the temperature accuracy was effectively improved from ＋5 C to 2 C.
文摘To the Editor:Alveolar rhabdomyosarcoma(ARMS)of nasalwingwith distant metastasis has a very poor prognosis.Because it is difficult to achieve complete surgical excision of the primary site of the nasal wing,distant metastasis is not easy to control.Here,we present an unusual case of a 29-month-old boy with ARMS in the left nasal wing accompanied by bone metastasis who was treated with systemic chemotherapy as well as 125I interstitial brachytherapy,and this special multidisciplinary management resulted in a perfect prognosis and mild long-term side effects.
