Electronic devices have become ubiquitous in our daily lives,leading to a surge in the use of microwave absorbers and wearable sensor devices across various sectors.A prime example of this trend is the aramid nanofibe...Electronic devices have become ubiquitous in our daily lives,leading to a surge in the use of microwave absorbers and wearable sensor devices across various sectors.A prime example of this trend is the aramid nanofibers/polypyrrole/nickel(APN)aerogels,which serve dual roles as both microwave absorbers and pressure sensors.In this work,we focused on the preparation of aramid nanofibers/polypyrrole(AP15)aerogels,where the mass ratio of aramid nanofibers to pyrrole was 1:5.We employed the oxidative polymerization method for the preparation process.Following this,nickel was thermally evaporated onto the surface of the AP15 aerogels,resulting in the creation of an ultralight(9.35 mg·cm^(-3)).This aerogel exhibited a porous structure.The introduction of nickel into the aerogel aimed to enhance magnetic loss and adjust impedance matching,thereby improving electromagnetic wave absorption performance.The minimum reflection loss value achieved was-48.7 dB,and the maximum effective absorption bandwidth spanned 8.42 GHz with a thickness of 2.9 mm.These impressive metrics can be attributed to the three-dimensional network porous structure of the aerogel and perfect impedance matching.Moreover,the use of aramid nanofibers and a three-dimensional hole structure endowed the APN aerogels with good insulation,flame-retardant properties,and compression resilience.Even under a compression strain of 50%,the aerogel maintained its resilience over 500 cycles.The incorporation of polypyrrole and nickel particles further enhanced the conductivity of the aerogel.Consequently,the final APN aerogel sensor demonstrated high sensitivity(10.78 kPa-1)and thermal stability.In conclusion,the APN aerogels hold significant promise as ultra-broadband microwave absorbers and pressure sensors.展开更多
We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes,as well as the formation mechanism of aggregates in reclaimed soil,to p...We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes,as well as the formation mechanism of aggregates in reclaimed soil,to provide a theoretical basis for rapid reclamation of soil fertility in the subsidence area of coal mines in Shanxi Province,China.In this study,soil samples of 0–20 cm depth were collected from four fertilization treatments of a longterm experiment started in 2008:no fertilizer (CK),inorganic fertilizer (NPK),chicken manure compost (M),and50%inorganic fertilizer plus 50%chicken manure compost (MNPK).The concentrations of cementing agents and changes in soil aggregate size distribution and stability were analysed.The results showed that the formation of>2 mm aggregates,the aggregate mean weight diameter (MWD),and the proportion of>0.25 mm water-stable aggregates (WR_(0.25)) increased significantly after 6 and 11 years of reclamation.The concentration of organic cementing agents tended to increase with reclamation time,whereas free iron oxide (Fed) and free aluminium oxide(Ald) concentrations initially increased but then decreased.In general,the MNPK treatment signi?cantly increased the concentrations of organic cementing agents and CaCO_(3),and CaCO_(3) increased by 60.4%at 11 years after reclamation.Additionally,CaCO_(3) had the greatest effect on the stability of aggregates,promoting the formation of>0.25 mm aggregates and accounting for 54.4%of the variance in the proportion and stability of the aggregates.It was concluded that long-term reclamation is bene?cial for improving soil structure.The MNPK treatment was the most effective measure for increasing maize grain yield and concentration of organic cementing agents and CaCO_(3).展开更多
Multifunctional carbon encapsulated Ni@NiO nanocomposites（Ni@NiO@C） were synthesized for applications in oxygen reduction reactions（ORR）,oxygen evolution reactions（OER） and lithium-ion batteries（LIB）. The morp...Multifunctional carbon encapsulated Ni@NiO nanocomposites（Ni@NiO@C） were synthesized for applications in oxygen reduction reactions（ORR）,oxygen evolution reactions（OER） and lithium-ion batteries（LIB）. The morphology was investigated via SEM and TEM,suggesting that the Ni@NiO@C nanocomposites have uniform and spherical core-shell structures. When the Ni@NiO@C nanocomposite is used as the catalyst in ORR,90% of the initial current density can be maintained after 15h in O_2-saturated 0.1 mol L^-1 KOH at 0.3 V under a rotation speed of 1600rpm.As a catalyst for OER,the highest activity overpotential of the Ni@NiO@C nanocomposite electrocatalyst is 380 mV（vs.RHE） under the current density of 10 mA cm^（-2）,and the Tafel slope was calculated to be 55 mV dec^-1 by linear fitting. Electrochemical performances of the Ni@NiO@C nanocomposites used as LIB electrodes exhibited a long cycling life with a high capacity of 750 mA h g^-1 after 400 cycles under 200 mA g^-1.展开更多
Lenvatinib is a targeted drug used for first-line treatment of hepatocellular carcinoma(HCC).A deeper insight into the resistance mechanism of HCC against lenvatinib is urgently needed.In this study,we aimed to dissec...Lenvatinib is a targeted drug used for first-line treatment of hepatocellular carcinoma(HCC).A deeper insight into the resistance mechanism of HCC against lenvatinib is urgently needed.In this study,we aimed to dissect the underlying mechanism of lenvatinib resistance(LR)and provide effective treatment strategies.We established an HCC model of acquired LR.Cell counting,migration,self-renewal ability,chemoresistance and expression of stemness genes were used to detect the stemness of HCC cells.Molecular and biochemical strategies such as RNA-sequencing,immunoprecipitation,mass spectrometry and ubiquitination assays were used to explore the underlying mechanisms.Patient-derived HCC models and HCC samples from patients were used to demonstrate clinical significance.We identified that increased cancer stemness driven by the hypoxia-inducible factor-1α(HIF-1α)pathway activation is responsible for acquired LR in HCC.Phosphorylated non-muscle myosin heavy chain 9(MYH9)at Ser1943,p-MYH9(Ser1943),could recruit ubiquitin-specific protease 22(USP22)to deubiquitinate and stabilize HIF-1αin lenvatinib-resistant HCC.Clinically,p-MYH9(Ser1943)expression was upregulated in HCC samples,which predicted poor prognosis and LR.A casein kinase-2(CK2)inhibitor and a USP22 inhibitor effectively reversed LR in vivo and in vitro.Therefore,the p-MYH9(Ser1943)/USP22/HIF-1αaxis is critical for LR and cancer stemness.For the diagnosis and treatment of LR in HCC,p-MYH9(Ser1943),USP22,and HIF-1αmight be valuable as novel biomarkers and targets.展开更多
Breaking the space-time symmetries in materials can markedly influence their electronic and optical properties.In 3R-stacked transition metal dichalcogenides,the explicitly broken inversion symmetry enables valley-con...Breaking the space-time symmetries in materials can markedly influence their electronic and optical properties.In 3R-stacked transition metal dichalcogenides,the explicitly broken inversion symmetry enables valley-contrasting Berry curvature and quantization of electronic angular momentum,providing an unprecedented platform for valleytronics.Here,we study the valley coherence of 3R WS_(2) large single-crystal with thicknesses ranging from monolayer to octalayer at room temperature.Our measurements demonstrate that both A and B excitons possess robust and thickness-independent valley coherence.The valley coherence of direct A(B)excitons can reach 0.742(0.653)with excitation conditions on resonance with it.Such giant and thickness-independent valley coherence of large single-crystal 3R WS_(2) at room temperature would provide a firm foundation for quantum manipulation of the valley degree of freedom and practical application of valleytronics.展开更多
In recent years,electromagnetic wave(EMW)absorption has been extensively investigated for solving EMW radiation and pollution.The metal-organic frameworks(MOFs)have attracted attention due to their low density and uni...In recent years,electromagnetic wave(EMW)absorption has been extensively investigated for solving EMW radiation and pollution.The metal-organic frameworks(MOFs)have attracted attention due to their low density and unique structure,which can meet the requirements of strong reflection loss(RL)and wide absorption bandwidth of EMW absorption materials.In this manuscript,indium nanoparticles/porous carbon(In/C)nanorods composites were prepared via the pyrolysis of nanorods-like In-MOFs at a low temperature of450°C.Indium nanoparticles are evenly attached and embedded on porous carbon.Low electrical conductivity of In/C nanorods is unfavorable to EMW absorption performance,which is due to the low temperature carbonization.Thus,graphene(Gr)nanosheets with high electrical conductivity are introduced to adjust electromagnetic parameters of In/C nanorods for enhancing EMW absorption.The minimum RL of the In/C-Gr-4 composite is up to-43.7 dB with a thin thickness of 1.30 mm.In addition,when the thickness is further reduced to 1.14 mm,the minimum RL of-39.3 dB at 16.1 GHz and effective absorption bandwidth of 3.7 GHz(from 14.3 to 18.0 GHz)can be achieved.This work indicates that In/C-Gr composites show excellent EMW absorption performance.展开更多
The three-dimensional nanoflower-like β-In2S3 composited with carbon nanotubes {CNTs） has been synthesized by a single mode micro- wave-assisted hydrothermal technique. The In2S3 and CNTs nanocomposites （In2S3@CNTs...The three-dimensional nanoflower-like β-In2S3 composited with carbon nanotubes {CNTs） has been synthesized by a single mode micro- wave-assisted hydrothermal technique. The In2S3 and CNTs nanocomposites （In2S3@CNTs） were investigated as the anode materials of lithium batteries （LIBs） and the electromagnetic wave absorption materials. For LIBs applications, the In2S3@CNTs nanocomposite exhibited excellent cycling stability with a high reversible charge capacity of 575 mA·h·g-1 after 300 cycles at 0.S A·g^-1, In addition, the In2S3@CNTs used as electromagnetic wave absorber displayed a maximum reflection loss of-42.75 dB at 11.96 GHz with a thickness of 1.55 ram.展开更多
Low dimensional semiconductors can be used for various electronic and optoelectronic devices because of their unique structure and property.In this work,one-dimensional Sb2 S3 nanowires(NWs)with high crystallinity wer...Low dimensional semiconductors can be used for various electronic and optoelectronic devices because of their unique structure and property.In this work,one-dimensional Sb2 S3 nanowires(NWs)with high crystallinity were grown via chemical vapor deposition(CVD)technique on SiO2/Si substrates.The Sb2 S3 NWs exhibited needle-like structures with inclined cross-sections.The lengths of Sb2S3 nanowires changed from 7 to 13μm.The photodetection properties of Sb2 S3 nanowires were comprehensively and systematically characterized.The Sb2S3 photodetectors show a broadband photoresponse ranging from ultraviolet(360 nm)to near-infrared(785 nm).An excellent specific detectivity of 2.1×10^(14)Jones,high external quantum efficiency of 1.5×10^(4)%,sensitivity of 2.2×10^(4)cm^(2)W^(-1)and short response time of less than 100 ms was achieved for the Sb2 S3 NW photodetectors.Moreover,the Sb2S3 NWs showed outstanding switch cycling stability that was beneficial to the practical applications.The high-quality Sb2S3 nanowires fabricated by CVD have great application potential in semiconductor and optoelectronic fields.展开更多
Tartary buckwheat(Fagopyrum tataricum)is an important pseudocereal feed crop with medicinal and nutritional value.Drought is one of the main causes of reduced growth and yield in these plants.We investigated the growt...Tartary buckwheat(Fagopyrum tataricum)is an important pseudocereal feed crop with medicinal and nutritional value.Drought is one of the main causes of reduced growth and yield in these plants.We investigated the growth,physiological,and metabolic responses of the widely promoted Tartary buckwheat variety Chuan Qiao No.1 to polyethylene glycol(PEG)-mediated drought stress.Drought significantly decreased shoot length,shoot biomass and relative water content.Root length,malondialdehyde content,electrolyte leakage,activities of superoxide dismutase,peroxidase,catalase and amylase,and contents of soluble sugar,soluble protein and proline were increased by PEG-mediated drought.Untargeted metabolomics analysis identified 32 core metabolites in seedlings subjected to PEG-mediated drought,16 of which increased—including quercetin,isovitexin,cyanidin 3-O-beta-D-glucoside,L-arginine,and glycerophosphocholine,while the other 16 decreased—including 3-methoxytyramine,2,6-diaminopimelic acid,citric acid,UDP-alpha-D-glucose,adenosine,keto-D-fructose.The 32 core metabolites were enriched in 29 metabolic pathways,including lysine biosynthesis,citrate(TCA)cycle,anthocyanin biosynthesis,and aminoacyl-tRNA biosynthesis.Among them,taurine and hypotaurine metabolism,flavor and flavor biosynthesis,indole alkaline biosynthesis,and alanine,aspartate and glutamate metabolism were the four main metabolic pathways affected by drought.Our findings provide new insights into the physiological and metabolic response mechanisms of Tartary buckwheat to drought stress.展开更多
Thin films of millimeter-scale continuous monolayer WS_(2) have been grown on SiO_(2)/Si substrate,followed by the deposition ofβ-In_(2)Se_(3) crystals on monolayer WS2 to prepare In_(2)Se_(3)/WS_(2) van deWaals hete...Thin films of millimeter-scale continuous monolayer WS_(2) have been grown on SiO_(2)/Si substrate,followed by the deposition ofβ-In_(2)Se_(3) crystals on monolayer WS2 to prepare In_(2)Se_(3)/WS_(2) van deWaals heterostructures by a two-step chemical vapor deposition(CVD)method.After the growth of In_(2)Se_(3) at elevated temperatures,high densities of In_(2)Se_(3)/WS_(2) heterostructure bubbles with monolayer to multilayerβ-In_(2)Se_(3) crystals atop are observed.Fluorescence of the resultantβ-In_(2)Se_(3)/WS_(2) heterostructure is greatly enhanced in intensity upon the formation of bubbles,which are evidenced by the Newton’s rings in optical image owing to constructive and destructive interference.In photoluminescence(PL)mapping images of monolayerβ-In_(2)Se_(3)/monolayer WS2 heterobilayer bubble,significant oscillatory behavior of emission intensity is demonstrated due to constructive and destructive interference.However,oscillatory behaviors of peak position are also observed and come from a local heating effect induced by an excitation laser beam.The oscillatory mechanism of PL is further verified by changing the exterior pressure of bubbles placed in a home-made vacuum chamber.In addition,redshifted in peak position and broadening in peak width are observed due to strain effect during decreasing the exterior pressure of bubbles.展开更多
Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2....Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2.2 eV)and strong light-matter interactions.Unfortunately,their practical applications are limited by low visible light absorption stemming from atomic thickness and negligible infrared response.Here,we report the triangular Sb_(2)O_(3) microresonators in wide thickness and lateral size distributions grown on 1L TMDCs and their created significant broadband enhancement of light adsorption and photoresponse in 1L WSe_(2) crystal via coexisting Fabry-Perot and whispering gallery type resonances.As an example of demonstration,1L WSe_(2) crystal coupled to Sb_(2)O_(3) microresonators with widely distributed sizes exhibits the enhanced visible light absorption by up to 5 folds and the simultaneously extended near infrared(NIR)one of more than 50%.For application of 1L WSe_(2) in photodetection,incorporation of Sb2O3 microresonators leads to significantly enhanced visible light responsivity by~10^(4) order and expanded NIR one of more than 400 mA·W^(-1).Similar results have been observed in the other 1L W(Mo)dichalcogenides coupled to Sb2O3 microresonators.This work provides a new route for development of the high-performance monolayer TMDCs-based optoelectronic devices.展开更多
基金The authors acknowledge the financial support from the National Natural Science Foundation of China(Nos.52071280 and 51972280)the Natural Science Foundation of Hebei Province,China(Nos.E2020203151 and E2022203208)+1 种基金the Research Program of the College Science&Technology of Hebei Province,China(No.ZD2020121)the Cultivation Project for Basic Research and Innovation of Yanshan University,China(No.2021LGZD016).
文摘Electronic devices have become ubiquitous in our daily lives,leading to a surge in the use of microwave absorbers and wearable sensor devices across various sectors.A prime example of this trend is the aramid nanofibers/polypyrrole/nickel(APN)aerogels,which serve dual roles as both microwave absorbers and pressure sensors.In this work,we focused on the preparation of aramid nanofibers/polypyrrole(AP15)aerogels,where the mass ratio of aramid nanofibers to pyrrole was 1:5.We employed the oxidative polymerization method for the preparation process.Following this,nickel was thermally evaporated onto the surface of the AP15 aerogels,resulting in the creation of an ultralight(9.35 mg·cm^(-3)).This aerogel exhibited a porous structure.The introduction of nickel into the aerogel aimed to enhance magnetic loss and adjust impedance matching,thereby improving electromagnetic wave absorption performance.The minimum reflection loss value achieved was-48.7 dB,and the maximum effective absorption bandwidth spanned 8.42 GHz with a thickness of 2.9 mm.These impressive metrics can be attributed to the three-dimensional network porous structure of the aerogel and perfect impedance matching.Moreover,the use of aramid nanofibers and a three-dimensional hole structure endowed the APN aerogels with good insulation,flame-retardant properties,and compression resilience.Even under a compression strain of 50%,the aerogel maintained its resilience over 500 cycles.The incorporation of polypyrrole and nickel particles further enhanced the conductivity of the aerogel.Consequently,the final APN aerogel sensor demonstrated high sensitivity(10.78 kPa-1)and thermal stability.In conclusion,the APN aerogels hold significant promise as ultra-broadband microwave absorbers and pressure sensors.
基金supported financially by the National Natural Science Foundation of China(41807102,U1710255-3 and 41907215)the Special Fund for Science and Technology Innovation Teams of Shanxi Province,China(202304051001042)the Distinguished and Excellent Young Scholar Cultivation Project of Shanxi Agricultural University,China(2022YQPYGC05)。
文摘We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes,as well as the formation mechanism of aggregates in reclaimed soil,to provide a theoretical basis for rapid reclamation of soil fertility in the subsidence area of coal mines in Shanxi Province,China.In this study,soil samples of 0–20 cm depth were collected from four fertilization treatments of a longterm experiment started in 2008:no fertilizer (CK),inorganic fertilizer (NPK),chicken manure compost (M),and50%inorganic fertilizer plus 50%chicken manure compost (MNPK).The concentrations of cementing agents and changes in soil aggregate size distribution and stability were analysed.The results showed that the formation of>2 mm aggregates,the aggregate mean weight diameter (MWD),and the proportion of>0.25 mm water-stable aggregates (WR_(0.25)) increased significantly after 6 and 11 years of reclamation.The concentration of organic cementing agents tended to increase with reclamation time,whereas free iron oxide (Fed) and free aluminium oxide(Ald) concentrations initially increased but then decreased.In general,the MNPK treatment signi?cantly increased the concentrations of organic cementing agents and CaCO_(3),and CaCO_(3) increased by 60.4%at 11 years after reclamation.Additionally,CaCO_(3) had the greatest effect on the stability of aggregates,promoting the formation of>0.25 mm aggregates and accounting for 54.4%of the variance in the proportion and stability of the aggregates.It was concluded that long-term reclamation is bene?cial for improving soil structure.The MNPK treatment was the most effective measure for increasing maize grain yield and concentration of organic cementing agents and CaCO_(3).
基金supported by the National Natural Science Foundation of China (51571172,51672240,51571171,and 11404280)the Natural Science Foundation for Distinguished Young Scholars of Hebei Province (E2017203095)+1 种基金the Natural Science Foundation of Hebei Province (E2016203484 and A2015203337)the Research Program of the College Science & Technology of Hebei Province (ZD2017083 and QN2014047)
文摘Multifunctional carbon encapsulated Ni@NiO nanocomposites（Ni@NiO@C） were synthesized for applications in oxygen reduction reactions（ORR）,oxygen evolution reactions（OER） and lithium-ion batteries（LIB）. The morphology was investigated via SEM and TEM,suggesting that the Ni@NiO@C nanocomposites have uniform and spherical core-shell structures. When the Ni@NiO@C nanocomposite is used as the catalyst in ORR,90% of the initial current density can be maintained after 15h in O_2-saturated 0.1 mol L^-1 KOH at 0.3 V under a rotation speed of 1600rpm.As a catalyst for OER,the highest activity overpotential of the Ni@NiO@C nanocomposite electrocatalyst is 380 mV（vs.RHE） under the current density of 10 mA cm^（-2）,and the Tafel slope was calculated to be 55 mV dec^-1 by linear fitting. Electrochemical performances of the Ni@NiO@C nanocomposites used as LIB electrodes exhibited a long cycling life with a high capacity of 750 mA h g^-1 after 400 cycles under 200 mA g^-1.
基金National Key Research and Development Program of China(2022YFA1106800),National Natural Science Foundation of China(82203070,82200726,82200727,92159202 and 82273270)Project of Medical and Health Technology Program in Zhejiang Province(2024KY853).
文摘Lenvatinib is a targeted drug used for first-line treatment of hepatocellular carcinoma(HCC).A deeper insight into the resistance mechanism of HCC against lenvatinib is urgently needed.In this study,we aimed to dissect the underlying mechanism of lenvatinib resistance(LR)and provide effective treatment strategies.We established an HCC model of acquired LR.Cell counting,migration,self-renewal ability,chemoresistance and expression of stemness genes were used to detect the stemness of HCC cells.Molecular and biochemical strategies such as RNA-sequencing,immunoprecipitation,mass spectrometry and ubiquitination assays were used to explore the underlying mechanisms.Patient-derived HCC models and HCC samples from patients were used to demonstrate clinical significance.We identified that increased cancer stemness driven by the hypoxia-inducible factor-1α(HIF-1α)pathway activation is responsible for acquired LR in HCC.Phosphorylated non-muscle myosin heavy chain 9(MYH9)at Ser1943,p-MYH9(Ser1943),could recruit ubiquitin-specific protease 22(USP22)to deubiquitinate and stabilize HIF-1αin lenvatinib-resistant HCC.Clinically,p-MYH9(Ser1943)expression was upregulated in HCC samples,which predicted poor prognosis and LR.A casein kinase-2(CK2)inhibitor and a USP22 inhibitor effectively reversed LR in vivo and in vitro.Therefore,the p-MYH9(Ser1943)/USP22/HIF-1αaxis is critical for LR and cancer stemness.For the diagnosis and treatment of LR in HCC,p-MYH9(Ser1943),USP22,and HIF-1αmight be valuable as novel biomarkers and targets.
基金This work was supported financially by the NSFC(grants:11834017 and 61888102)the Strategic Priority Research Program of CAS(grant:XDB30000000)+5 种基金the Key Research Program of Frontier Sciences of CAS(grant:QYZDBSSW-SLH004)the National Key R&D program(grant:2016YFA0300904)the financial supports from Business Finland(A-Photonics)the Academy of Finland(grants:276376,284548,286920,295777,298297,304666,312297,312551,and 314810)the Academy of Finland Flagship Programme(320167,PREIN)the European Union’s Horizon 2020 research and innovation programme(820423,S2QUIP).
文摘Breaking the space-time symmetries in materials can markedly influence their electronic and optical properties.In 3R-stacked transition metal dichalcogenides,the explicitly broken inversion symmetry enables valley-contrasting Berry curvature and quantization of electronic angular momentum,providing an unprecedented platform for valleytronics.Here,we study the valley coherence of 3R WS_(2) large single-crystal with thicknesses ranging from monolayer to octalayer at room temperature.Our measurements demonstrate that both A and B excitons possess robust and thickness-independent valley coherence.The valley coherence of direct A(B)excitons can reach 0.742(0.653)with excitation conditions on resonance with it.Such giant and thickness-independent valley coherence of large single-crystal 3R WS_(2) at room temperature would provide a firm foundation for quantum manipulation of the valley degree of freedom and practical application of valleytronics.
基金supported by the National Natural Science Foundation of China(No.52071280)the Natural Science Foundation of Hebei Province,China(No.E2020203151)+2 种基金the Research Program of the College Science&Technology of Hebei Province,China(No.ZD2020121)the Cultivation Project for Basic Research and Innovation of Yanshan University(No.2021LGZD016)the Innovation Capability Improvement Project of Hebei province(No.22567605H)。
文摘In recent years,electromagnetic wave(EMW)absorption has been extensively investigated for solving EMW radiation and pollution.The metal-organic frameworks(MOFs)have attracted attention due to their low density and unique structure,which can meet the requirements of strong reflection loss(RL)and wide absorption bandwidth of EMW absorption materials.In this manuscript,indium nanoparticles/porous carbon(In/C)nanorods composites were prepared via the pyrolysis of nanorods-like In-MOFs at a low temperature of450°C.Indium nanoparticles are evenly attached and embedded on porous carbon.Low electrical conductivity of In/C nanorods is unfavorable to EMW absorption performance,which is due to the low temperature carbonization.Thus,graphene(Gr)nanosheets with high electrical conductivity are introduced to adjust electromagnetic parameters of In/C nanorods for enhancing EMW absorption.The minimum RL of the In/C-Gr-4 composite is up to-43.7 dB with a thin thickness of 1.30 mm.In addition,when the thickness is further reduced to 1.14 mm,the minimum RL of-39.3 dB at 16.1 GHz and effective absorption bandwidth of 3.7 GHz(from 14.3 to 18.0 GHz)can be achieved.This work indicates that In/C-Gr composites show excellent EMW absorption performance.
基金We are grateful to the National Natural Science Foundation of China （51571172, 11404280, 51571171, 516722401, Natural Science Foundation for Distinguished Young Scholars of Hebei Province （E2017203095）, Natural Science Foundation of Hebei Province （A2015203337, E2016203484）, Science Foundation for the Excellent Youth Scholars from Universities and Colleges of Hebei Province （YQ2014009）, and Research Program of the College Science ＆ Technology of Hebei Province （ZD2017083, QN2014047）.
文摘The three-dimensional nanoflower-like β-In2S3 composited with carbon nanotubes {CNTs） has been synthesized by a single mode micro- wave-assisted hydrothermal technique. The In2S3 and CNTs nanocomposites （In2S3@CNTs） were investigated as the anode materials of lithium batteries （LIBs） and the electromagnetic wave absorption materials. For LIBs applications, the In2S3@CNTs nanocomposite exhibited excellent cycling stability with a high reversible charge capacity of 575 mA·h·g-1 after 300 cycles at 0.S A·g^-1, In addition, the In2S3@CNTs used as electromagnetic wave absorber displayed a maximum reflection loss of-42.75 dB at 11.96 GHz with a thickness of 1.55 ram.
基金supported by the National Natural Science Foundation of China(51732010,51972280,51672240,51801175)。
文摘Low dimensional semiconductors can be used for various electronic and optoelectronic devices because of their unique structure and property.In this work,one-dimensional Sb2 S3 nanowires(NWs)with high crystallinity were grown via chemical vapor deposition(CVD)technique on SiO2/Si substrates.The Sb2 S3 NWs exhibited needle-like structures with inclined cross-sections.The lengths of Sb2S3 nanowires changed from 7 to 13μm.The photodetection properties of Sb2 S3 nanowires were comprehensively and systematically characterized.The Sb2S3 photodetectors show a broadband photoresponse ranging from ultraviolet(360 nm)to near-infrared(785 nm).An excellent specific detectivity of 2.1×10^(14)Jones,high external quantum efficiency of 1.5×10^(4)%,sensitivity of 2.2×10^(4)cm^(2)W^(-1)and short response time of less than 100 ms was achieved for the Sb2 S3 NW photodetectors.Moreover,the Sb2S3 NWs showed outstanding switch cycling stability that was beneficial to the practical applications.The high-quality Sb2S3 nanowires fabricated by CVD have great application potential in semiconductor and optoelectronic fields.
基金We acknowledge the Project of National Key Research and Development Program of China(2020YFD1001403)China Agriculture Research System(CARS-07-B-1)+3 种基金Science&Technology Department of Sichuan Province(2022YFQ0041)the National Natural Science Foundation of China(31601260,32160428)Innovative Training Program for College Students(S202111079058)Special Research Fund from Key Laboratory of Coarse Cereal Processing,Ministry of Agriculture and Rural Affairs(2020CC012)to facilitate the research.
文摘Tartary buckwheat(Fagopyrum tataricum)is an important pseudocereal feed crop with medicinal and nutritional value.Drought is one of the main causes of reduced growth and yield in these plants.We investigated the growth,physiological,and metabolic responses of the widely promoted Tartary buckwheat variety Chuan Qiao No.1 to polyethylene glycol(PEG)-mediated drought stress.Drought significantly decreased shoot length,shoot biomass and relative water content.Root length,malondialdehyde content,electrolyte leakage,activities of superoxide dismutase,peroxidase,catalase and amylase,and contents of soluble sugar,soluble protein and proline were increased by PEG-mediated drought.Untargeted metabolomics analysis identified 32 core metabolites in seedlings subjected to PEG-mediated drought,16 of which increased—including quercetin,isovitexin,cyanidin 3-O-beta-D-glucoside,L-arginine,and glycerophosphocholine,while the other 16 decreased—including 3-methoxytyramine,2,6-diaminopimelic acid,citric acid,UDP-alpha-D-glucose,adenosine,keto-D-fructose.The 32 core metabolites were enriched in 29 metabolic pathways,including lysine biosynthesis,citrate(TCA)cycle,anthocyanin biosynthesis,and aminoacyl-tRNA biosynthesis.Among them,taurine and hypotaurine metabolism,flavor and flavor biosynthesis,indole alkaline biosynthesis,and alanine,aspartate and glutamate metabolism were the four main metabolic pathways affected by drought.Our findings provide new insights into the physiological and metabolic response mechanisms of Tartary buckwheat to drought stress.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51732010 and 51972280)the Natural Science Foundation of Hebei Province,China(Grant No.E2019203233)the Research Program of the College Science&Technology of Hebei Province,China(Grant No.ZD2020121).
文摘Thin films of millimeter-scale continuous monolayer WS_(2) have been grown on SiO_(2)/Si substrate,followed by the deposition ofβ-In_(2)Se_(3) crystals on monolayer WS2 to prepare In_(2)Se_(3)/WS_(2) van deWaals heterostructures by a two-step chemical vapor deposition(CVD)method.After the growth of In_(2)Se_(3) at elevated temperatures,high densities of In_(2)Se_(3)/WS_(2) heterostructure bubbles with monolayer to multilayerβ-In_(2)Se_(3) crystals atop are observed.Fluorescence of the resultantβ-In_(2)Se_(3)/WS_(2) heterostructure is greatly enhanced in intensity upon the formation of bubbles,which are evidenced by the Newton’s rings in optical image owing to constructive and destructive interference.In photoluminescence(PL)mapping images of monolayerβ-In_(2)Se_(3)/monolayer WS2 heterobilayer bubble,significant oscillatory behavior of emission intensity is demonstrated due to constructive and destructive interference.However,oscillatory behaviors of peak position are also observed and come from a local heating effect induced by an excitation laser beam.The oscillatory mechanism of PL is further verified by changing the exterior pressure of bubbles placed in a home-made vacuum chamber.In addition,redshifted in peak position and broadening in peak width are observed due to strain effect during decreasing the exterior pressure of bubbles.
基金This work is supported by the National Natural Science Foundation of China(Nos.51732010,5197228051801175),and Natural Science Foundation of Hebei Province(No.E2019203233).
文摘Monolayer(1L)transition metal dichalcogenides(TMDCs)have been attracting tremendous interest in recent years as promising candidate materials in atomic-scale optoelectronic devices due to their direct band gaps(1.5-2.2 eV)and strong light-matter interactions.Unfortunately,their practical applications are limited by low visible light absorption stemming from atomic thickness and negligible infrared response.Here,we report the triangular Sb_(2)O_(3) microresonators in wide thickness and lateral size distributions grown on 1L TMDCs and their created significant broadband enhancement of light adsorption and photoresponse in 1L WSe_(2) crystal via coexisting Fabry-Perot and whispering gallery type resonances.As an example of demonstration,1L WSe_(2) crystal coupled to Sb_(2)O_(3) microresonators with widely distributed sizes exhibits the enhanced visible light absorption by up to 5 folds and the simultaneously extended near infrared(NIR)one of more than 50%.For application of 1L WSe_(2) in photodetection,incorporation of Sb2O3 microresonators leads to significantly enhanced visible light responsivity by~10^(4) order and expanded NIR one of more than 400 mA·W^(-1).Similar results have been observed in the other 1L W(Mo)dichalcogenides coupled to Sb2O3 microresonators.This work provides a new route for development of the high-performance monolayer TMDCs-based optoelectronic devices.
