Furious dendritic growth and destructive parasitic reactions(hydrogen evolution reaction,corrosion,and passivation)severely degraded the development of aqueous Zn-ion batteries(AZIBs)in the field of grid and stationar...Furious dendritic growth and destructive parasitic reactions(hydrogen evolution reaction,corrosion,and passivation)severely degraded the development of aqueous Zn-ion batteries(AZIBs)in the field of grid and stationary energy storage.Herein,trace amount of tetracycline hydrochloride(TC-HCl)additive(only 0.5 mM)is employed as a mediator to steer a stable Zn anode-electrolyte interface.Informed by theoretical calculations and experiment analysis,TC molecule with zincophilic groups can remodel the solvation sheath and disrupt H-bonds network due to its high electronegative O atoms,which effectively expedites the desolvation process and reduces the electrochemical activity of solvent water.Additionally,the TC molecules are preferentially adsorbed on the Zn electrode than active water molecules,which are beneficial for steering uniform nucleation and restricting the erosion of electrode.Benefitting from these synergistic effects,the Zn//Zn symmetric cell containing TC-HCl additive exhibits an ultra-long cycle life of exceeding 2200 h at 1.0 mA cm^(-2)and 1.0 mAh cm^(-2).Accordingly,the practical Zn//α-MnO_(2)full cell using the modified electrolyte also demonstrates the enhanced performance.This study provides valuable insights into the widespread use of trace electrolyte additives and facilitates the industrialization of AZIBs with long lifespans.展开更多
The Saxi tungsten deposit,located in the Laojunshan ore district of southeastern Yunnan Province,is a significant W-polymetallic deposit.The origins of tungstenbearing pegmatite dikes and quartz vein mineralization in...The Saxi tungsten deposit,located in the Laojunshan ore district of southeastern Yunnan Province,is a significant W-polymetallic deposit.The origins of tungstenbearing pegmatite dikes and quartz vein mineralization in the Saxi deposit remain poorly understood.This study employs in situ U-Pb dating of apatite from the altered granite,along with trace element and S-Pb isotopic analysis of arsenopyrite,to investigate the timing,source of ore-forming fluids and the mechanisms of tungsten enrichment.The apatite in the altered granite yields a U-Pb age of 147.0±4.0 Ma,indicating magmatic activity during the Early Cretaceous.Three generations of arsenopyrite(Apy)are identified:Apy-1 in the altered granite,Apy-2 in the pegmatite dikes and Apy-3 in the quartz veins.The S/Fe ratios for Apy-1,Apy-2 and Apy-3 range from 0.98 to 1.09,0.89 to 0.92 and 0.86 to 1.02,respectively(average 0.97),suggesting a magmatic-hydrothermal origin.Sulfur isotope values(δ^(34)S=4.29‰-8.11‰)indicate that it was likely sourced from deep magmatic-hydrothermal fluids.Lead isotopic compositions of arsenopyrite suggest that the granitic parental magma is derived from the upper crust.These findings point to a magmatic-hydrothermal origin for the vein-type tungsten mineralization,linked to a concealed magmatichydrothermal system in the Early Cretaceous.展开更多
The apparent OER activity on S-incorporated catalyst outputs an over-estimated current,which is actually contributed not only from the oxygen evolution reaction(OER),but also from the inevitable surface reconstruction...The apparent OER activity on S-incorporated catalyst outputs an over-estimated current,which is actually contributed not only from the oxygen evolution reaction(OER),but also from the inevitable surface reconstruction-involved electrochemical oxidation reactions.The mechanism of such catalysts still remains complex and controversial.Here,we applied a set of operando electrochemical-spectrometric methodologies to investigate the precise interfacial activation process on the bimetallic sulfide heterogeneous catalyst,which delivers an extraordinary OER activity of 100 mA cm^(-2) at 190 mV overpotential.Differential electrochemical mass spectrometry(DEMS)suggested the electrochemical oxidations of the lattice S to SO,SO_(2) and SO_(4)^(2-)species and the coordinately unsaturated metal sites.Operando Raman and attenuated total reflectance surface-enhanced infrared absorption spectra confirmed the phase transformation of sulfide to oxide,and then to oxyhydroxide,which acted as an active site for OER.The density functional theory also simulated this process by showing that the(CoNi)_(x)S_(y) transition phase exhibited the optimal activity,and elucidated the attenuation kinetics of the apparent activity during OER.This study demonstrates the structure evolution of a certain S-incorporated catalyst and establishes the protocol for the real activity identification under the real-time reaction.展开更多
Scalable printing of stretchable conjugated polymer films offers the opportunity to develop low-cost and large-area wearable electronics.However,achieving optimal film morphology to simultaneously improve energy dissi...Scalable printing of stretchable conjugated polymer films offers the opportunity to develop low-cost and large-area wearable electronics.However,achieving optimal film morphology to simultaneously improve energy dissipation and charge transport is still challenging for printed conjugated polymer films.Herein,we fabricate large-area stretchable conjugated polymer films with low crystallinity but strong chain alignment toward a high-performance wearable X-ray detector by simultaneously regulating fluid field and solidification dynamics during bar-coating.The strong fluid field aligns conjugated polymer chains in the coating direction and enhances solution aggregation in the initial wet layer,while sequential rapid solidification of the thin wet layer further restricts polymer crystallization but facilitates the alignment of aggregates,forming highly-aligned nanofiber networks within the elastomer phase.The elastomer-constrained nanofiber networks can further align with strain to maintain connectivity,providing an efficient charge transport channel during stretching.Consequently,the film shows high charge mobilities of 6.11 and 2.98 cm^(2)V^(−1)s^(−1)under 0%and 100%strains,among the highest values for stretchable conjugated polymer films.The designed film also exhibits a high sensitivity of 1757.2µC G_(yair)^(−1)cm^(−2)and an ultralow detection limit of 72.5 nG_(yair)s^(−1),maintaining good X-ray imaging capability before and after stretching.展开更多
Rationally regulating the inevitable dynamic evolution of the catalyst surface structure towards high efficiency for water electrolysis remains a significant challenge.Here,the ternary cobalt-iron-chromium double hydr...Rationally regulating the inevitable dynamic evolution of the catalyst surface structure towards high efficiency for water electrolysis remains a significant challenge.Here,the ternary cobalt-iron-chromium double hydroxide(DH)was synthesized on nickel foam as a monolithic catalytic electrode(CoFeCr-DH/NF)for the oxygen evolution reaction(OER)via a simple electrodeposition technique.The optimized Co_(0.7)Fe_(0.3)Cr-DH/NF electrode exhibited remarkable catalytic activity and stability.The overpotential at the current density of 100 mA cm^(-2) is only 281 mV,far exceeding those of other monolithic catalytic electrodes.Furthermore,we elucidated the variations in the valence states of metals during the OER process and found the electrochemical oxidation of Co^(2+)to Co^(3+)and leaching of Cr.Importantly,Cr-leaching can induce surface reconstruction,which not only optimizes the surface electronic structure to enhance the intrinsic activity but also increases the surface irregularity to enlarge the electrochemically active surface area,thereby significantly improving the OER performance.Theoretical calculations revealed that OER preferentially occurred at the adjacent Cr-leached Co sites and confirmed that the Cr-leached trimetallic CoFeCr-DH performs an outstanding OER performance.展开更多
Highly effident metal-free, carbon-based, bi-functional electrocatalysts for the oxygen evolution reaction （OER） and oxygen reduction reaction （ORR） have attracted increased attention for use in electrochemical en...Highly effident metal-free, carbon-based, bi-functional electrocatalysts for the oxygen evolution reaction （OER） and oxygen reduction reaction （ORR） have attracted increased attention for use in electrochemical energy conversion systems, owing to their low cost and high activity. In this work, N-doped carbon nanocages （N-CCs） with a porous self-supported architecture and high specific surface area are synthesized by a facile interfacial assembly synthetic route. The materials are comprehensively characterized by scanning electron microscop36 transmission electron microscopy, nitrogen adsorption-desorption experiments, X-ray diffraction, and X-ray photoelectron spectroscopy. Cyclic voltammetry , chronoamperometry, and linear sweep voltammetry demonstrate that the as-prepared N-CC could serve as an effective metal-free electrocatalyst with excellent catalytic activity, long-term operation durability, and excellent methanol tolerance for the ORR in alkaline media. In the presence of 3 mM methanol, the half wave potential of the N-CCs for the ORR is 190 mV; this is more positive than that of the commercial Pt/C electrocatalyst. Meanwhile, the N-CCs also show an OER activity comparable to that of the commercial Ru/C electrocatalyst, revealing their bifunctional property.展开更多
The purpose of this study was to explore the variations in the circulating leptin concentrations of the wild ground squirrels in relation to seasonal changes in testicular activities.Hematoxylin-eosin staining showed ...The purpose of this study was to explore the variations in the circulating leptin concentrations of the wild ground squirrels in relation to seasonal changes in testicular activities.Hematoxylin-eosin staining showed all types of elongated spermatids and spermatogenic cells existed in the testis in April,while the primary spermatocytes and spermatogonia were most advanced stages of germ cells in June.In addition,the primary spermatocytes,secondary spermatocytes,and spermatogonia were most advanced stages of germ cells in September.The highest circulating leptin concentration was consistent with the maximum body weight results from accumulation of adipose tissue in September.The mRNA expression level of leptin receptor(Ob-R)and STAT3 was lowest in June,raised in September,and remained increased in April.Ob-R and STAT3 were stronger staining in the Leydig cells in July.Moreover,the concentrations of testosterone(T)showed the maximum values in April,the minimum values in June,and significant increases in September.Furthermore,it is worth noting that the levels of T increased with the mRNA levels of Ob-R,STAT3,StAR,and testicular steroidogenic enzymes(3β-HSD,P450c17,and P450scc).Moreover,RNA-seq analyses of testis during the different periods showed that a total of 4209 genes were differ-entially expressed genes(DEGs);further analysis revealed that DEGs related with the Jak/STAT pathways and reproduction were altered.Taken together,the results suggested that the leptin regulated testicular function through the Jak/STAT pathways and testicular steroidogenic factor expressions.展开更多
基金supported by the National Natural Science Foundation of China(51702081)。
文摘Furious dendritic growth and destructive parasitic reactions(hydrogen evolution reaction,corrosion,and passivation)severely degraded the development of aqueous Zn-ion batteries(AZIBs)in the field of grid and stationary energy storage.Herein,trace amount of tetracycline hydrochloride(TC-HCl)additive(only 0.5 mM)is employed as a mediator to steer a stable Zn anode-electrolyte interface.Informed by theoretical calculations and experiment analysis,TC molecule with zincophilic groups can remodel the solvation sheath and disrupt H-bonds network due to its high electronegative O atoms,which effectively expedites the desolvation process and reduces the electrochemical activity of solvent water.Additionally,the TC molecules are preferentially adsorbed on the Zn electrode than active water molecules,which are beneficial for steering uniform nucleation and restricting the erosion of electrode.Benefitting from these synergistic effects,the Zn//Zn symmetric cell containing TC-HCl additive exhibits an ultra-long cycle life of exceeding 2200 h at 1.0 mA cm^(-2)and 1.0 mAh cm^(-2).Accordingly,the practical Zn//α-MnO_(2)full cell using the modified electrolyte also demonstrates the enhanced performance.This study provides valuable insights into the widespread use of trace electrolyte additives and facilitates the industrialization of AZIBs with long lifespans.
基金Yunnan Major Scientific and Technological Project(grant no.202202AG050006)National Natural Science Foundation project(grant No.42272078)Yunnan Fundamental Research Project(grant No.202401CF070094).
文摘The Saxi tungsten deposit,located in the Laojunshan ore district of southeastern Yunnan Province,is a significant W-polymetallic deposit.The origins of tungstenbearing pegmatite dikes and quartz vein mineralization in the Saxi deposit remain poorly understood.This study employs in situ U-Pb dating of apatite from the altered granite,along with trace element and S-Pb isotopic analysis of arsenopyrite,to investigate the timing,source of ore-forming fluids and the mechanisms of tungsten enrichment.The apatite in the altered granite yields a U-Pb age of 147.0±4.0 Ma,indicating magmatic activity during the Early Cretaceous.Three generations of arsenopyrite(Apy)are identified:Apy-1 in the altered granite,Apy-2 in the pegmatite dikes and Apy-3 in the quartz veins.The S/Fe ratios for Apy-1,Apy-2 and Apy-3 range from 0.98 to 1.09,0.89 to 0.92 and 0.86 to 1.02,respectively(average 0.97),suggesting a magmatic-hydrothermal origin.Sulfur isotope values(δ^(34)S=4.29‰-8.11‰)indicate that it was likely sourced from deep magmatic-hydrothermal fluids.Lead isotopic compositions of arsenopyrite suggest that the granitic parental magma is derived from the upper crust.These findings point to a magmatic-hydrothermal origin for the vein-type tungsten mineralization,linked to a concealed magmatichydrothermal system in the Early Cretaceous.
基金supported by the National Natural Science Foundation of China(22162026,22402115,22102184)the Central University Basic Research Fund of China(GK202304010)+4 种基金the Sanqin Youth Talent Project of Shaanxi Province(YJ002)the Shaanxi Provincial Science and Technology Plan Project(2020JQ-792)the Science and Technology Plan Project of Yulin Government(2023-CXY-213,CXY-2022186)the Innovation and Entrepreneurship Training Program for Undergraduates(S202310719113,D2022082,D2022083)the support from the Australian Research Council(DP210103892,IC200100023)。
文摘The apparent OER activity on S-incorporated catalyst outputs an over-estimated current,which is actually contributed not only from the oxygen evolution reaction(OER),but also from the inevitable surface reconstruction-involved electrochemical oxidation reactions.The mechanism of such catalysts still remains complex and controversial.Here,we applied a set of operando electrochemical-spectrometric methodologies to investigate the precise interfacial activation process on the bimetallic sulfide heterogeneous catalyst,which delivers an extraordinary OER activity of 100 mA cm^(-2) at 190 mV overpotential.Differential electrochemical mass spectrometry(DEMS)suggested the electrochemical oxidations of the lattice S to SO,SO_(2) and SO_(4)^(2-)species and the coordinately unsaturated metal sites.Operando Raman and attenuated total reflectance surface-enhanced infrared absorption spectra confirmed the phase transformation of sulfide to oxide,and then to oxyhydroxide,which acted as an active site for OER.The density functional theory also simulated this process by showing that the(CoNi)_(x)S_(y) transition phase exhibited the optimal activity,and elucidated the attenuation kinetics of the apparent activity during OER.This study demonstrates the structure evolution of a certain S-incorporated catalyst and establishes the protocol for the real activity identification under the real-time reaction.
基金supported by the National Natural Science Foundation of China(52433009)the Fundamental Research Funds for the Central Universities(GK202501005)the Young Scientist Initiative Project of School of Materials Science and Engineering at Shaanxi Normal University(2024YSIP-MSE-SNNU012)。
文摘Scalable printing of stretchable conjugated polymer films offers the opportunity to develop low-cost and large-area wearable electronics.However,achieving optimal film morphology to simultaneously improve energy dissipation and charge transport is still challenging for printed conjugated polymer films.Herein,we fabricate large-area stretchable conjugated polymer films with low crystallinity but strong chain alignment toward a high-performance wearable X-ray detector by simultaneously regulating fluid field and solidification dynamics during bar-coating.The strong fluid field aligns conjugated polymer chains in the coating direction and enhances solution aggregation in the initial wet layer,while sequential rapid solidification of the thin wet layer further restricts polymer crystallization but facilitates the alignment of aggregates,forming highly-aligned nanofiber networks within the elastomer phase.The elastomer-constrained nanofiber networks can further align with strain to maintain connectivity,providing an efficient charge transport channel during stretching.Consequently,the film shows high charge mobilities of 6.11 and 2.98 cm^(2)V^(−1)s^(−1)under 0%and 100%strains,among the highest values for stretchable conjugated polymer films.The designed film also exhibits a high sensitivity of 1757.2µC G_(yair)^(−1)cm^(−2)and an ultralow detection limit of 72.5 nG_(yair)s^(−1),maintaining good X-ray imaging capability before and after stretching.
基金financially supported by the National Natural Science Foundation of China(Nos.22162026 and 22263011)the Shaanxi Provincial Science and Technology Plan Project(No.2020JQ-792)+2 种基金the Youth Science and Technology Star Project of Shaanxi Province(No.2023KJXX-053)the Science and Technology Plan Project of Yulin Government(Nos.CXY-2022-82,CXY-2022-186,and 2023-CXY-213)the Training Program of Innovation and Entrepreneurship for Undergraduates(No.S202310719113).
文摘Rationally regulating the inevitable dynamic evolution of the catalyst surface structure towards high efficiency for water electrolysis remains a significant challenge.Here,the ternary cobalt-iron-chromium double hydroxide(DH)was synthesized on nickel foam as a monolithic catalytic electrode(CoFeCr-DH/NF)for the oxygen evolution reaction(OER)via a simple electrodeposition technique.The optimized Co_(0.7)Fe_(0.3)Cr-DH/NF electrode exhibited remarkable catalytic activity and stability.The overpotential at the current density of 100 mA cm^(-2) is only 281 mV,far exceeding those of other monolithic catalytic electrodes.Furthermore,we elucidated the variations in the valence states of metals during the OER process and found the electrochemical oxidation of Co^(2+)to Co^(3+)and leaching of Cr.Importantly,Cr-leaching can induce surface reconstruction,which not only optimizes the surface electronic structure to enhance the intrinsic activity but also increases the surface irregularity to enlarge the electrochemically active surface area,thereby significantly improving the OER performance.Theoretical calculations revealed that OER preferentially occurred at the adjacent Cr-leached Co sites and confirmed that the Cr-leached trimetallic CoFeCr-DH performs an outstanding OER performance.
基金This research was sponsored by Key Technologies R＆D Program of Shaanxi Province （Nos. 2014K10-06 and 2015XT-18）, the National Natural Science Foundation of China （Nos. 51373092 and 21543012）, the Funda-mental Research Funds for the Central Universities （Nos. GK201503038 and GK201501002）, Program for Key Science ＆ Technology Innovation Team of Shaanxi Province （No. 2015KCT-13）, and the 111 Project （No. B14041）.
文摘Highly effident metal-free, carbon-based, bi-functional electrocatalysts for the oxygen evolution reaction （OER） and oxygen reduction reaction （ORR） have attracted increased attention for use in electrochemical energy conversion systems, owing to their low cost and high activity. In this work, N-doped carbon nanocages （N-CCs） with a porous self-supported architecture and high specific surface area are synthesized by a facile interfacial assembly synthetic route. The materials are comprehensively characterized by scanning electron microscop36 transmission electron microscopy, nitrogen adsorption-desorption experiments, X-ray diffraction, and X-ray photoelectron spectroscopy. Cyclic voltammetry , chronoamperometry, and linear sweep voltammetry demonstrate that the as-prepared N-CC could serve as an effective metal-free electrocatalyst with excellent catalytic activity, long-term operation durability, and excellent methanol tolerance for the ORR in alkaline media. In the presence of 3 mM methanol, the half wave potential of the N-CCs for the ORR is 190 mV; this is more positive than that of the commercial Pt/C electrocatalyst. Meanwhile, the N-CCs also show an OER activity comparable to that of the commercial Ru/C electrocatalyst, revealing their bifunctional property.
基金supported by the National Natural Science Foundation of China(31872320,21806010)the Young Scientist Start-up funding of Beijing Forestry University(BLX201714).
文摘The purpose of this study was to explore the variations in the circulating leptin concentrations of the wild ground squirrels in relation to seasonal changes in testicular activities.Hematoxylin-eosin staining showed all types of elongated spermatids and spermatogenic cells existed in the testis in April,while the primary spermatocytes and spermatogonia were most advanced stages of germ cells in June.In addition,the primary spermatocytes,secondary spermatocytes,and spermatogonia were most advanced stages of germ cells in September.The highest circulating leptin concentration was consistent with the maximum body weight results from accumulation of adipose tissue in September.The mRNA expression level of leptin receptor(Ob-R)and STAT3 was lowest in June,raised in September,and remained increased in April.Ob-R and STAT3 were stronger staining in the Leydig cells in July.Moreover,the concentrations of testosterone(T)showed the maximum values in April,the minimum values in June,and significant increases in September.Furthermore,it is worth noting that the levels of T increased with the mRNA levels of Ob-R,STAT3,StAR,and testicular steroidogenic enzymes(3β-HSD,P450c17,and P450scc).Moreover,RNA-seq analyses of testis during the different periods showed that a total of 4209 genes were differ-entially expressed genes(DEGs);further analysis revealed that DEGs related with the Jak/STAT pathways and reproduction were altered.Taken together,the results suggested that the leptin regulated testicular function through the Jak/STAT pathways and testicular steroidogenic factor expressions.
