The correlation of ambient noise with wind speed,and the depth dependence of ambient noise are both investigated,where the ocean noise data were recorded by a vertical line array in the northern South China Sea.It is ...The correlation of ambient noise with wind speed,and the depth dependence of ambient noise are both investigated,where the ocean noise data were recorded by a vertical line array in the northern South China Sea.It is shown that the correlation coefficients increase with increasing hydrophone depth during typhoon periods when the frequency≥250 Hz,which opposes the generally accepted knowledge that the correlation coefficients of noise level and wind speed decrease with increasing depth during non-typhoon periods.Particularly at frequencies of 250 Hz,315 Hz and 400 Hz,the correlation coefficients increase by more than 0.05 at depths ranging from 155 m to 875 m.At the three frequencies,the average noise levels also increase with increasing depth during typhoon periods.It is suggested that these differences are attributed to the wind-generated noise in shallow waters and the effect of"downslope enhancement"to sound propagation.During typhoon periods,the surf breaking and surf beat upon the shores and reefs are strengthened,and the source levels are increased.The wind-generated noise in shallow waters interacts with the downslope sea floor,with the noise-depth distribution changed by a"downslope enhancement"effect promoting noise propagation.展开更多
Promoting interfacial reaction kinetics is highly desirable for achieving high-performances of anode material in alkali-ion batteries.Herein,flower-like MoSe_(2)/MoO_(3-x)@r GO composites are fabricated by a facile so...Promoting interfacial reaction kinetics is highly desirable for achieving high-performances of anode material in alkali-ion batteries.Herein,flower-like MoSe_(2)/MoO_(3-x)@r GO composites are fabricated by a facile solvothermal method involving a thermal-treatment at 800°C.When evaluated as an anode material for potassium ion batteries,MoSe_(2)/MoO_(3-x)@r GO delivers 248.2 m A h g^(-1)after 50 cycles at 0.2 A g^(-1) with a capacity retention of 84.6%and 182.9 m A h g^(-1)after 150 cycles at 1.0 A g^(-1) with a capacity retention of almost 61.2%,superior to those of bare MoSe_(2)or MoSe_(2)@r GO composites.Analysis from electrochemical measurements,the amorphous MoO_(3-x)containing oxygen vacancies could not only effectively buffer the self-aggregation of MoSe_(2)nanosheets but also provides lots of accessible active sites for potassium ion storage.Additionally,the open channels in the amorphous MoO_(3-x) phase lead to easier ion hopping and smaller diffusion barriers.Furthermore,the built-in electric field at the interface would be beneficial for electron transfer and K-ion migration across the hetero-junction interface.Moreover,larger dielectric polarization induced by the high relative permittivity of amorphous MoO_(3-x) would reduce charge transfer resistance and enhance K-ion migration across electric double-layer.Our work provides new insight into the enhanced performance of anode material coated by an amorphous layer with large relative permittivity.展开更多
Under-ice ambient noise in the Arctic Ocean is studied using the data recorded by autonomous hydrophones at the long-term ice station during the 9th Chinese National Arctic Research Expedition.Time-frequency analysis ...Under-ice ambient noise in the Arctic Ocean is studied using the data recorded by autonomous hydrophones at the long-term ice station during the 9th Chinese National Arctic Research Expedition.Time-frequency analysis of two 7-s-long ice-induced noise samples shows that both ice collision and ice breaking noise have many outliers in the time-domain(impulsive characteristic)and abundant frequency components in the frequency-domain.Ice collision noise lasts for several seconds while the duration of ice breaking noise is much shorter(i.e.,less than tens of milliseconds).Gaussian distribution and symmetric alpha stable(sαs)distribution are used in this paper to fit the impulsive under-ice noise.The sαs distribution can achieve better performance as it can track the heavy tails of impulsive noise while Gaussian distribution fails.This paper also analyzes the meteorological variables during the under-ice noise observation experiment and deduces that the impulsive ambient noise was caused by the combined force of high wind speed and increasing atmosphere temperature on the ice canopy.The Pearson correlation coefficients between long-term power spectral density variations of under-ice ambient noise and meteorological variables are also studied in this paper.展开更多
Synthetic aperture radar(SAR)images play an increasingly important role in ocean environmental monitoring and research.However,SAR images are inherently corrupted by speckle noise.SAR ocean images have some unique cha...Synthetic aperture radar(SAR)images play an increasingly important role in ocean environmental monitoring and research.However,SAR images are inherently corrupted by speckle noise.SAR ocean images have some unique characteristics.The signatures of ocean phenomena in SAR images mainly exhibit as stripe or plaque shaped features.These features typically have a high degree of self-similarity or redundancy.The nonlocal means(NLM)method can measure the structural similarity between different image patches and take advantage of redundant information in images.Considering that the NLM algorithm is computationally intensive and timeconsuming,an accelerated NLM algorithm for SAR ocean image despeckling is proposed in this paper.A method is used to discriminate between texture and flat pixels in SAR images.Large similarity and search windows are used on texture pixels,whereas small similarity and search windows are used on flat pixels.Furthermore,the improved NLM algorithm is accelerated by a graphic processing unit(GPU)based on the compute unified device architecture(CUDA)parallel computation framework.The computational efficiency is improved by approximately 200 times.展开更多
Biochar amendment offers a chance for sustainable agriculture.However,the effectiveness of biochar relies on its physical and chemical properties,which are heavily affected by biochar production conditions and managem...Biochar amendment offers a chance for sustainable agriculture.However,the effectiveness of biochar relies on its physical and chemical properties,which are heavily affected by biochar production conditions and management practices.Therefore,substantial uncertainties regarding the use of biochar exist in agricultural systems globally.This study provides the first quantitative evaluation of the impacts of biochar characteristics and management practices on key ecosystem services by performing a second-order meta-analysis based on 34,628 paired observations in biochar-amended and unamended systems.Overall,biochar enhances phytotoxicity alleviation,physiology regulation,soil remediation and carbon sequestration,and microbial functional gene abundance.However,some prominent trade-offs exist between crop productivity and ecosystem service deliveries including for nutrient cycling,microbial function,climate change mitigation,and the soil microbial community.The adoption of low C:N biochar produced at high pyrolysis temperatures from sewage sludge-derived feedstock,in combination with a moderate application rate and inorganic fertilizer input,shows potential for achieving synergistic promotion of crop productivity and ecosystem services.These outcomes highlight the need for judicious implementation of biochar-based solutions to site-specific soil constraints.The quantified synergy and tradeoff relationships will aid the establishment of a sustainable biochar development framework that strengthens necessary ecosystem services commensurate with food security assurance.展开更多
The focal mechanism solution of the Shiqu MS 4.4 earthquake occurred on May 16th,2017 in Sichuan Province is studied by the gCAP method using the waveform data from the regional seismic networks in Sichuan,Qinghai,Tib...The focal mechanism solution of the Shiqu MS 4.4 earthquake occurred on May 16th,2017 in Sichuan Province is studied by the gCAP method using the waveform data from the regional seismic networks in Sichuan,Qinghai,Tibet and Gansu provinces.The strike/dip/dipping angle of the first nodal plane are 214/80/167and those of the second nodal plane are 306/77/10,the optimal centroid depth is 7.30.6 km and the moment magnitude is MW 4.5.Furthermore,the study investigates the robustness of the results against the error of crustal velocity structure,location,data quality and difference of seismic parameters,subsequently obtaining a stable resolved focal mechanism.According to the geological structure in the seismogenic area,spatial distribution of aftershock sequenceof the regional tectonic stress field,and the focal mechanism of the main shock,we suggest that the Shiqu earthquake is induced by a left-lateral strike-slip mechanism and the second nodal plane is inferred to be the seismogenic fault,consistent with the geometry of the Changshagongma fault which is the secondary fault of the northwest part of the Xianshuihe fault zone.展开更多
As one of the hallmarks of cancer,metabolic reprogramming leads to cancer progression,and targeting glycolytic enzymes could be useful strategies for cancer therapy.By screening a small molecule library consisting of ...As one of the hallmarks of cancer,metabolic reprogramming leads to cancer progression,and targeting glycolytic enzymes could be useful strategies for cancer therapy.By screening a small molecule library consisting of 1320 FDA-approved drugs,we found that penfluridol,an antipsychotic drug used to treat schizophrenia,could inhibit glycolysis and induce apoptosis in esophageal squamous cell carcinoma(ESCC).Gene profiling and Ingenuity Pathway Analysis suggested the important role of AMPK in action mechanism of penfluridol.By using drug affinity responsive target stability(DARTS)technology and proteomics,we identified phosphofructokinase,liver type(PFKL),a key enzyme in glycolysis,as a direct target of penfluridol.Penfluridol could not exhibit its anticancer property in PFKL-deficient cancer cells,illustrating that PFKL is essential for the bioactivity of penfluridol.High PFKL expression is correlated with advanced stages and poor survival of ESCC patients,and silencing of PFKL significantly suppressed tumor growth.Mechanistically,direct binding of penfluridol and PFKL inhibits glucose consumption,lactate and ATP production,leads to nuclear translocation of FOXO3a and subsequent transcriptional activation of BIM in an AMPK-dependent manner.Taken together,PFKL is a potential prognostic biomarker and therapeutic target in ESCC,and penfluridol may be a new therapeutic option for management of this lethal disease.展开更多
基金The National Natural Science Foundation of China under contract No.41606116the Natural Science Foundation of Fujian Province of China under contract No.2016J01019the National Key R&D Program of China under contract No.2018YFC1405903。
文摘The correlation of ambient noise with wind speed,and the depth dependence of ambient noise are both investigated,where the ocean noise data were recorded by a vertical line array in the northern South China Sea.It is shown that the correlation coefficients increase with increasing hydrophone depth during typhoon periods when the frequency≥250 Hz,which opposes the generally accepted knowledge that the correlation coefficients of noise level and wind speed decrease with increasing depth during non-typhoon periods.Particularly at frequencies of 250 Hz,315 Hz and 400 Hz,the correlation coefficients increase by more than 0.05 at depths ranging from 155 m to 875 m.At the three frequencies,the average noise levels also increase with increasing depth during typhoon periods.It is suggested that these differences are attributed to the wind-generated noise in shallow waters and the effect of"downslope enhancement"to sound propagation.During typhoon periods,the surf breaking and surf beat upon the shores and reefs are strengthened,and the source levels are increased.The wind-generated noise in shallow waters interacts with the downslope sea floor,with the noise-depth distribution changed by a"downslope enhancement"effect promoting noise propagation.
基金the Natural Science Foundations of China(Nos.12174057,22179020)Natural Science Foundation of Fuccccjian Province(No.2021L3011)Fujian Natural Science Foundation for Distinguished Young Scholars(No.2020J06042)。
文摘Promoting interfacial reaction kinetics is highly desirable for achieving high-performances of anode material in alkali-ion batteries.Herein,flower-like MoSe_(2)/MoO_(3-x)@r GO composites are fabricated by a facile solvothermal method involving a thermal-treatment at 800°C.When evaluated as an anode material for potassium ion batteries,MoSe_(2)/MoO_(3-x)@r GO delivers 248.2 m A h g^(-1)after 50 cycles at 0.2 A g^(-1) with a capacity retention of 84.6%and 182.9 m A h g^(-1)after 150 cycles at 1.0 A g^(-1) with a capacity retention of almost 61.2%,superior to those of bare MoSe_(2)or MoSe_(2)@r GO composites.Analysis from electrochemical measurements,the amorphous MoO_(3-x)containing oxygen vacancies could not only effectively buffer the self-aggregation of MoSe_(2)nanosheets but also provides lots of accessible active sites for potassium ion storage.Additionally,the open channels in the amorphous MoO_(3-x) phase lead to easier ion hopping and smaller diffusion barriers.Furthermore,the built-in electric field at the interface would be beneficial for electron transfer and K-ion migration across the hetero-junction interface.Moreover,larger dielectric polarization induced by the high relative permittivity of amorphous MoO_(3-x) would reduce charge transfer resistance and enhance K-ion migration across electric double-layer.Our work provides new insight into the enhanced performance of anode material coated by an amorphous layer with large relative permittivity.
基金The National Natural Science Foundation of China under contract Nos 61631008,61901136 and 51779061the National Key Research and Development Program of China under contract No.2018YFC1405904+2 种基金the Fok Ying-Tong Education Foundation under contract No.151007the Opening Funding of Science and Technology on Sonar Laboratory under contract No.6142109KF201802the Innovation Special Zone of National Defense Science and Technology.
文摘Under-ice ambient noise in the Arctic Ocean is studied using the data recorded by autonomous hydrophones at the long-term ice station during the 9th Chinese National Arctic Research Expedition.Time-frequency analysis of two 7-s-long ice-induced noise samples shows that both ice collision and ice breaking noise have many outliers in the time-domain(impulsive characteristic)and abundant frequency components in the frequency-domain.Ice collision noise lasts for several seconds while the duration of ice breaking noise is much shorter(i.e.,less than tens of milliseconds).Gaussian distribution and symmetric alpha stable(sαs)distribution are used in this paper to fit the impulsive under-ice noise.The sαs distribution can achieve better performance as it can track the heavy tails of impulsive noise while Gaussian distribution fails.This paper also analyzes the meteorological variables during the under-ice noise observation experiment and deduces that the impulsive ambient noise was caused by the combined force of high wind speed and increasing atmosphere temperature on the ice canopy.The Pearson correlation coefficients between long-term power spectral density variations of under-ice ambient noise and meteorological variables are also studied in this paper.
基金The Scientific Research Foundation of Third Institute of Oceanography,SOA under contract No.2015008the National Natural Science Foundation of China under contract No.61601132
文摘Synthetic aperture radar(SAR)images play an increasingly important role in ocean environmental monitoring and research.However,SAR images are inherently corrupted by speckle noise.SAR ocean images have some unique characteristics.The signatures of ocean phenomena in SAR images mainly exhibit as stripe or plaque shaped features.These features typically have a high degree of self-similarity or redundancy.The nonlocal means(NLM)method can measure the structural similarity between different image patches and take advantage of redundant information in images.Considering that the NLM algorithm is computationally intensive and timeconsuming,an accelerated NLM algorithm for SAR ocean image despeckling is proposed in this paper.A method is used to discriminate between texture and flat pixels in SAR images.Large similarity and search windows are used on texture pixels,whereas small similarity and search windows are used on flat pixels.Furthermore,the improved NLM algorithm is accelerated by a graphic processing unit(GPU)based on the compute unified device architecture(CUDA)parallel computation framework.The computational efficiency is improved by approximately 200 times.
基金funded by the National Natural Science Foundation of China(32272233)the National Key Research and Development Program of China(2023YFD2302300)+1 种基金the Shaanxi Innovative Talents Promotion Plan,China(2023KJXX-012)the Science and Technology Plan Project of Inner Mongolia,China(2022YFDZ0018)。
文摘Biochar amendment offers a chance for sustainable agriculture.However,the effectiveness of biochar relies on its physical and chemical properties,which are heavily affected by biochar production conditions and management practices.Therefore,substantial uncertainties regarding the use of biochar exist in agricultural systems globally.This study provides the first quantitative evaluation of the impacts of biochar characteristics and management practices on key ecosystem services by performing a second-order meta-analysis based on 34,628 paired observations in biochar-amended and unamended systems.Overall,biochar enhances phytotoxicity alleviation,physiology regulation,soil remediation and carbon sequestration,and microbial functional gene abundance.However,some prominent trade-offs exist between crop productivity and ecosystem service deliveries including for nutrient cycling,microbial function,climate change mitigation,and the soil microbial community.The adoption of low C:N biochar produced at high pyrolysis temperatures from sewage sludge-derived feedstock,in combination with a moderate application rate and inorganic fertilizer input,shows potential for achieving synergistic promotion of crop productivity and ecosystem services.These outcomes highlight the need for judicious implementation of biochar-based solutions to site-specific soil constraints.The quantified synergy and tradeoff relationships will aid the establishment of a sustainable biochar development framework that strengthens necessary ecosystem services commensurate with food security assurance.
基金sponsored by The Key Project of Director Fund of Earthquake Agency of Inner Mongolia Autonomous Region,China(2020TM04)the Key Youth Task of Earthquake Emergency of China Earthquake Administration,China(CEA_EDEM-202103)Project of Director Fund of Earthquake Agency of Inner Mongolia Autonomous Region,China(2019JC27).
文摘The focal mechanism solution of the Shiqu MS 4.4 earthquake occurred on May 16th,2017 in Sichuan Province is studied by the gCAP method using the waveform data from the regional seismic networks in Sichuan,Qinghai,Tibet and Gansu provinces.The strike/dip/dipping angle of the first nodal plane are 214/80/167and those of the second nodal plane are 306/77/10,the optimal centroid depth is 7.30.6 km and the moment magnitude is MW 4.5.Furthermore,the study investigates the robustness of the results against the error of crustal velocity structure,location,data quality and difference of seismic parameters,subsequently obtaining a stable resolved focal mechanism.According to the geological structure in the seismogenic area,spatial distribution of aftershock sequenceof the regional tectonic stress field,and the focal mechanism of the main shock,we suggest that the Shiqu earthquake is induced by a left-lateral strike-slip mechanism and the second nodal plane is inferred to be the seismogenic fault,consistent with the geometry of the Changshagongma fault which is the secondary fault of the northwest part of the Xianshuihe fault zone.
基金supported by National Natural Science Foundation of China(31961160727,81773085,and 81973339)National Key Research and Development Program of China(2017YFA0505100)Guangdong Natural Science Research Grant International joint project(2021A0505030035,China)。
文摘As one of the hallmarks of cancer,metabolic reprogramming leads to cancer progression,and targeting glycolytic enzymes could be useful strategies for cancer therapy.By screening a small molecule library consisting of 1320 FDA-approved drugs,we found that penfluridol,an antipsychotic drug used to treat schizophrenia,could inhibit glycolysis and induce apoptosis in esophageal squamous cell carcinoma(ESCC).Gene profiling and Ingenuity Pathway Analysis suggested the important role of AMPK in action mechanism of penfluridol.By using drug affinity responsive target stability(DARTS)technology and proteomics,we identified phosphofructokinase,liver type(PFKL),a key enzyme in glycolysis,as a direct target of penfluridol.Penfluridol could not exhibit its anticancer property in PFKL-deficient cancer cells,illustrating that PFKL is essential for the bioactivity of penfluridol.High PFKL expression is correlated with advanced stages and poor survival of ESCC patients,and silencing of PFKL significantly suppressed tumor growth.Mechanistically,direct binding of penfluridol and PFKL inhibits glucose consumption,lactate and ATP production,leads to nuclear translocation of FOXO3a and subsequent transcriptional activation of BIM in an AMPK-dependent manner.Taken together,PFKL is a potential prognostic biomarker and therapeutic target in ESCC,and penfluridol may be a new therapeutic option for management of this lethal disease.
