In photolithography,shortening the exposure wavelength from ultraviolet to extreme ultraviolet(EUV,13.5 nm)and soft X-ray region in terms of beyond EUV(BEUV,6.X nm)and water window X-ray(WWX,2.2–4.4 nm)is expected to...In photolithography,shortening the exposure wavelength from ultraviolet to extreme ultraviolet(EUV,13.5 nm)and soft X-ray region in terms of beyond EUV(BEUV,6.X nm)and water window X-ray(WWX,2.2–4.4 nm)is expected to further miniaturize the technology node down to sub-5 nm level.However,the absorption ability of molecules in these ranges,especially WWX region,is unknown,which should be very important for the utilization of energy.Herein,the molar absorption cross sections of different elements at 2.4 nm of WWX were firstly calculated and compared with the wavelengths of 13.5 nm and 6.7 nm.Based on the absorption cross sections in these ranges and density estimation results from the density-functional theory calculation,the linear absorption coefficients of typical resist materials,including metal-oxy clusters,organic small molecules,polymers,and photoacid generators(PAGs),are evaluated.The analysis suggests that the Zn cluster has higher absorption in BEUV,whereas the Sn cluster has higher absorption in WWX.Doping PAGs with high EUV absorption atoms improves chemically amplified photoresist(CAR)polymer absorption performance.However,for WWX,it is necessary to introduce an absorption layer containing high WWX absorption elements such as Zr,Sn,and Hf to increase the WWX absorption.展开更多
For many water quality studies,a data analyst,or modeler, may need to know the spatio-temproal patterns of the data sets and their relationships in both pre-processing and post-processing. Geographic Information Syste...For many water quality studies,a data analyst,or modeler, may need to know the spatio-temproal patterns of the data sets and their relationships in both pre-processing and post-processing. Geographic Information System(GIS) can provide an exploratory spat展开更多
Palladium-based catalysts have long been considered the benchmark for methane combustion;however,the authentic phase of catalytic active sites remains a subject of ongoing debate.Additionally,challenges like water-poi...Palladium-based catalysts have long been considered the benchmark for methane combustion;however,the authentic phase of catalytic active sites remains a subject of ongoing debate.Additionally,challenges like water-poisoning and long-term stability need to be addressed to advance catalyst performance.Herein,we investigate Pd on Co_(3)O_(4) nanorods as a highly effective catalyst for catalytic oxidation of methane,demonstrating long-term stability and water tolerance during a 100-h continuous operation at 350℃.Comprehensive characterizations reveal the presence of an active Pd-oxygen vacancy(Ov)-cobalt interface in Pd/Co_(3)O_(4),which effectively adsorbs molecular O_(2).The absorbed oxygen species on this interface are activated and directly participate in methane combustion.Moreover,near-ambient pressure X-ray photoelectron spectroscopy demonstrates that Pd nanoparticles undergo a rapid phase transition and predominantly remain in the metallic state during the reaction.This behavior is attributed to the electronic metal-support interaction between Pd and Co_(3)O_(4).Furthermore,in situ Fourier transformed infrared spectrum reveals that under reaction conditions,HCO3*species are formed initially and subsequently transformed into formate species,indicating that the formate pathway is the dominant mechanism for CH_(4) oxidation.展开更多
The oxidation behavior of alloy 690 exposed to high-temperature and high-pressure steam and water at 280℃ for 1 h was investigated by scanning electron microscopy （SEM）, atomic force microscopy （AFM） and X-ray ph...The oxidation behavior of alloy 690 exposed to high-temperature and high-pressure steam and water at 280℃ for 1 h was investigated by scanning electron microscopy （SEM）, atomic force microscopy （AFM） and X-ray photoelectron spectroscopy （XPS）. In high-temperature and high-pressure steam, the oxide film is composed of an outermost Ni-rich hydroxides layer, an intermediate layer of hydroxides and oxides enriched in Cr, an inner oxide layer. The film formed in high-temperature water is similar to that in steam, except for missing the Ni-rich hydroxides layer. Samples with different surface finishes （electropolished, mechanically polished, ground, and as-received） were prepared for comparison. A general increase of the oxide thickness with the degree of surface roughness is observed. The equivalent oxide thicknesses lie in the range of 100-200 nm for the as-received samples, 150-250 nm for the samples ground to 400# and 10-20 nm for the samples ground to 1500#, mechanically polished, and electropolished.展开更多
In recent years,persistent luminescence materials(PLMs)excited by X-rays and emitting in biological windows have received extensive attention in the field of high-sensitivity bioimaging.Transition metal Mn^(2+)is an i...In recent years,persistent luminescence materials(PLMs)excited by X-rays and emitting in biological windows have received extensive attention in the field of high-sensitivity bioimaging.Transition metal Mn^(2+)is an ideal emission center,but few studies focus on Mn^(2+)-doped PLMs with X-ray excitation and biological window emission.Here,we report a Mn^(2+)-doped PLM,LiYGeO_(4):Mn^(2+)(LYGM),with excellent biological window persistent luminescence emission.After excitation by UV,LYGM produces a durable biological window of persistent luminescence emission at 660 nm for up to 20 h.More importantly.LYGM can be repeatedly excited by X-rays,resulting in long-term biological window persistent luminescence emission.In addition,we obtain LYGM around 200 nm in diameter by ball milling and centrifugation and improve its biocompatibility by surface modification to apply it to in vivo imaging in mice.After LYGM are injected into mice through the tail vein,in situ excitation of X-rays can be achieved.After the persistent luminescence decays,LYGM can be re-excited for repeated imaging.Therefore,LYGM shows potential prospects for in vivo deep tissue and long-term bioimaging.展开更多
Nanostructured iron oxyhydroxide（Fe OOH） thin films have been synthesized using an electrodeposition method on a nickel foam（NF） substrate and effect of air annealing temperature on the catalytic performance is st...Nanostructured iron oxyhydroxide（Fe OOH） thin films have been synthesized using an electrodeposition method on a nickel foam（NF） substrate and effect of air annealing temperature on the catalytic performance is studied. The as-deposited and annealed thin films were characterized by X-ray diffraction（XRD）,X-ray photoelectron spectroscopy（XPS）, field emission scanning electron microscopy（FE-SEM） and linear sweep voltammetry（LSV） to determine their structural, morphological, compositional and electrochemical properties, respectively. The as-deposited nanostructured amorphous Fe OOH thin film is converted into a polycrystalline Fe;O;with hematite crystal structure at a high temperature. The Fe OOH thin film acts as an efficient electrocatalyst for the oxygen evolution reaction（OER） in an alkaline 1 M KOH electrolyte. The film annealed at 200 °C shows high catalytic activity with an onset overpotential of 240 m V with a smaller Tafel slope of 48 m V/dec. Additionally, it needs an overpotential of 290 mV to the drive the current density of 10 m A/cm;and shows good stability in the 1 M KOH electrolyte solution.展开更多
Multilayer graphene as a potential anti-oxidation barrier to protect nickel foils from oxidation was studied in simulated primary water of pressurized water reactors （PWRs）. The results show that after immersion for...Multilayer graphene as a potential anti-oxidation barrier to protect nickel foils from oxidation was studied in simulated primary water of pressurized water reactors （PWRs）. The results show that after immersion for 1000 h, the structure of the multilayer graphene remains unchanged and no obvious oxide film formed on the graphene coated nickel foils, indicating multilayer graphene can effectively act as the anti-oxidation barrier to protect the substrate from oxidation and hence can improve the heat transfer efficiency of the substrate in simulated primary water of PWRs.展开更多
The penetration of water during water flooding has been observed over many years using several methods. A microfocused X-ray computed tomography scanner can be used to directly observe 3D water flooding in a nondestru...The penetration of water during water flooding has been observed over many years using several methods. A microfocused X-ray computed tomography scanner can be used to directly observe 3D water flooding in a nondestructive manner. To eliminate the possibility of false images being produced because of X-ray broadening effects, we developed a visualization method by arranging the brightness distribution of all phases involved. Water flooding experiments were conducted using oil-wet and water-wet porous media. The water phase was injected upward into packed glass beads containing an oil phase, and the process was scanned every minute until steady state was reached. Using this scheme, real-time, the water invasion pattern and oil trapping process in clusters of pores and individual pores can be observed clearly. By eliminating false images, the boundary of each phase could be identified with high precision, even in a single pore. Porelevel phenomena, including snap off (which has never before been captured in a real 3D porous medium), piston-like displacement, and the curvature of the interface, were also observed. Direct measurement of the pore throat radius and the contact angle between the wetting and nonwetting phases gave an approximation of the capillary pressure during the piston-like displacement and snap-off processes.展开更多
Computer-aided diagnosis(CAD)models exploit artificial intelligence(AI)for chest X-ray(CXR)examination to identify the presence of tuberculosis(TB)and can improve the feasibility and performance of CXR for TB screenin...Computer-aided diagnosis(CAD)models exploit artificial intelligence(AI)for chest X-ray(CXR)examination to identify the presence of tuberculosis(TB)and can improve the feasibility and performance of CXR for TB screening and triage.At the same time,CXR interpretation is a time-consuming and subjective process.Furthermore,high resemblance among the radiological patterns of TB and other lung diseases can result in misdiagnosis.Therefore,computer-aided diagnosis(CAD)models using machine learning(ML)and deep learning(DL)can be designed for screening TB accurately.With this motivation,this article develops a Water Strider Optimization with Deep Transfer Learning Enabled Tuberculosis Classification(WSODTL-TBC)model on Chest X-rays(CXR).The presented WSODTL-TBC model aims to detect and classify TB on CXR images.Primarily,the WSODTL-TBC model undergoes image filtering techniques to discard the noise content and U-Net-based image segmentation.Besides,a pre-trained residual network with a two-dimensional convolutional neural network(2D-CNN)model is applied to extract feature vectors.In addition,the WSO algorithm with long short-term memory(LSTM)model was employed for identifying and classifying TB,where the WSO algorithm is applied as a hyperparameter optimizer of the LSTM methodology,showing the novelty of the work.The performance validation of the presented WSODTL-TBC model is carried out on the benchmark dataset,and the outcomes were investigated in many aspects.The experimental development pointed out the betterment of the WSODTL-TBC model over existing algorithms.展开更多
The motion of a lure in water is investigated experimentally and numerically.The lure motion in water of apassing water tank is observed,and the periodic motion is found.From the Fourier analysis,it is found that the ...The motion of a lure in water is investigated experimentally and numerically.The lure motion in water of apassing water tank is observed,and the periodic motion is found.From the Fourier analysis,it is found that the frequency with the largest amplitude in the lateral direction depends on the lip width of the lure.To understand the lure dynamics,a numerical simulation of the flow field around the lure is performed.The shape is measured using an X-ray computer tomography and converted into a voxel model.From visualization,it is found that vortex sheds from its lip correspond to the vibration frequency of the lure.展开更多
Satellite retrieval of atmospheric water vapor is intended to further understand the role played by the energy and water cycle to determine the Earth's weather and climate.The algorithm for operational retrieval o...Satellite retrieval of atmospheric water vapor is intended to further understand the role played by the energy and water cycle to determine the Earth's weather and climate.The algorithm for operational retrieval of total precipitable water (TPW) from the visible and infrared radiometer (VIRR) onboard Fengyun 3A (FY-3A) employs a split window technique for clear sky radiances over land and oceans during both day and night.The retrieved TPW is compared with that from the moderate resolution imaging spectroradiometer (MODIS) onboard the Terra satellite and data from radiosonde observations (RAOB).During the study period,comparisons show that the FY-3A TPW is in general agreement with the gradients and distributions from the Terra TPW.Their zonal mean difference over East Asia is smaller in the daytime than at night,and the main difference occurs in the complex terrain at mid latitude near 30°N.Compared with RAOB,the zonal FY-3A and the Terra TPW have a moist bias at low latitudes and a dry bias at mid and high latitudes;in addition,the FY-3A TPW performs slightly better in zonal mean biases and the diurnal cycle.The temporal variation of the FY-3A and the Terra TPW generally fits the RAOB TPW with the FY-3A more accurate at night while Terra TPW more accurate during the daytime.Comparisons of correlations,root mean square differences and standard deviations indicate that the FY-3A TPW series is more consistent with the RAOB TPW at selected stations.As a result,the FY-3A TPW has some advantages over East Asia in both spatial and temporal dimensions.展开更多
Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the ...Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the development of aqueous electrolytes to a new height,the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce.Herein,in order to enrich the type of aqueous electrolyte with high operative voltage,tetramethylammonium trifluoromethanesulfonate(TMAOTf)based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile(ACN)co-solvent and LiTFSI co-solute.In view of the coordination effect of ACN and Lit on free water in TMAOTf based WIS electrolyte,the TMAt-Lit-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V.Further coupled with the commercial YP-50F electrodes,TMAt-Lit-AWIS based SCs exhibited wide operative voltage window(2.5 V),long cycling life(45,000 cycles)and good low-temperature performance(99.99%capacitance retention after 2000 cycles at20℃).The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.展开更多
This study is designed to investigate the suitability of selected Nigeria clay deposit for clay based ceramic water filters (CWFs). Clay samples were taken from five randomly selected locations in Nigeria Namely: Okpe...This study is designed to investigate the suitability of selected Nigeria clay deposit for clay based ceramic water filters (CWFs). Clay samples were taken from five randomly selected locations in Nigeria Namely: Okpella (Edo<sup>1</sup>) and Ojirami (Edo<sup>2</sup>) in Edo;Ikere in Ekiti state;FUTA in Ondo state and Onibode in Ogun to determine their suitability for clay based ceramic water filters (CWFs). Experimental analysis for linear shrinkage, water absorption, bulk density, compressive strength X-ray diffraction (XRD) and X-ray Fluorescence (XRF) was carried out on each of the clay samples. Test results reveal that all the clays contain high contents of alumina (Al<sub>2</sub>O<sub>3</sub>) and silica (SiO<sub>2</sub>) with minor contents of P<sub>2</sub>O<sub>5</sub>, Fe<sub>2</sub>O<sub>3</sub>, MgO, K<sub>2</sub>O, MnO and TiO<sub>2</sub>. The average crystal sizes of the clay were between 15 and 27 nm. Lattice structure indicates that the sample is Monoclinic and Anorthic. Ceramic water filters (CWFs) were made from a mixture of clay and sawdust at different volume ratios, and processed into test samples. Water absorption, linear shrinkage and compressive strength of the clay based ceramic filters (CWFs), reveal that as the volume ratio of sawdust increases these properties decrease. Flow rate analysis indicates that Edo and Ekiti ceramic water filters (CWFs) have higher flow rates. The research indicates that Edo and Ekiti Clay with specification of some industrial clays shows that the samples can be recommended for use in clay based ceramic water filters production.展开更多
Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not mee...Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not meet the requirements of analysis for time-sensitive samples and/or complicated environmental samples. Since energy-dispersive X-ray spectrometry(EDS) can be used to simultaneously detect multiple elements in a sample, including sulfur, with minimal sample treatment, this technology was applied to detect sulfur-oxidizing bacteria using their high sulfur content within the cell. This article describes the application of scanning electron microscopy imaging coupled with EDS mapping for quick detection of sulfur oxidizers in contaminated environmental water samples, with minimal sample handling. Scanning electron microscopy imaging revealed the existence of dense granules within the bacterial cells, while EDS identified large amounts of sulfur within them. EDS mapping localized the sulfur to these granules. Subsequent 16S rRNA gene sequencing showed that the bacteria detected in our samples belonged to the genus Chromatium, which are sulfur oxidizers. Thus, EDS mapping made it possible to identify sulfur oxidizers in environmental samples based on localized sulfur within their cells, within a short time(within 24 h of sampling). This technique has wide ranging applications for detection of sulfur bacteria in environmental water samples.展开更多
Atmospheric water harvesting offers a powerful and promising solution to address the problem of global freshwater scarcity.In the past decade,significant progress has been achieved in utilizing hydrolytically stable m...Atmospheric water harvesting offers a powerful and promising solution to address the problem of global freshwater scarcity.In the past decade,significant progress has been achieved in utilizing hydrolytically stable metal-organic frameworks as recyclable water-sorbent materials under low relative humidity,especially in those arid areas.Recently,Yaghi's group has employed a combined crystallographic and theoretical technique to decipher the water filling mechanism in MOF-303,where the polar organic linkers rather than the inorganic units of MOF are demonstrated as the key factor.Hence,the hydrophilic strength of the water-binding pocket in MOFs can be optimized through the approach of multivariate modulations,resulting in enhanced water harvesting properties.展开更多
Beryllium （Be） window is a key component of the ITER radial X-ray camera （RXC）. The Be window presented in this paper has a mechanical clamping structure, the thickness of the Be foil is 80 μm, and the X-ray thre...Beryllium （Be） window is a key component of the ITER radial X-ray camera （RXC）. The Be window presented in this paper has a mechanical clamping structure, the thickness of the Be foil is 80 μm, and the X-ray threshold of the 80 μm Be foil is 1.24 keV. A honeycomb support is designed and applied to strengthen the Be foil to prevent it from breakage when it is exposed to 1 atm perssure. Based on analysis results, the hole diameter of the support is chosen as 4 mm. A metal seal is used to isolate the vacuum on two sides of the Be window, the hollow metal sealing ring ensures the He leakage rate of the Be window being lower than 6× 10^-1 Pa.m^3.s^-1. Baking （240 ℃, 2 h） and vibration（3.3 Hz, 2 h） tests are carried out and the feasibility of the Be window＇s sealant in these situations is tested. The Be window has good stability that can save maintenance cost as well as enhancing the safety of the RXC.展开更多
The effect of (Pt-loaded)TiO2 crystallite diameter (i.e. Scherrer size) on the photocatalytic water splitting rate was investigated. (Pt-loaded)TiO2 powders with a wide range of crystallite diameters from about 16 to ...The effect of (Pt-loaded)TiO2 crystallite diameter (i.e. Scherrer size) on the photocatalytic water splitting rate was investigated. (Pt-loaded)TiO2 powders with a wide range of crystallite diameters from about 16 to 45 nm with a blank region between about 23 and 41 nm were prepared by various annealing processes from an identical TiO2 powder. Water splitting experiments with these powders were carried out with methanol as an oxidizing sacrificial agent. It was found that the photocatalytic water splitting rate was sensitively affected by the crystallite diameter of the (Pt-loaded)TiO2 powder. More concretely, similar steep improvements of photocatalytic water splitting rates from around 15 and a little over 2 to about 30 μmol·m-2hr-1?were obtained in the two (Pt-loaded)TiO2 crystallite diameters ranging from 16 to 23 and from 41 to 45 nm, respectively.展开更多
基金supported by the National Natural Science Foundation of China(22090011,22378052)the Fundamental Research Funds for China Central Universities(DUT22LAB608 and DUT20RC(3)030)+1 种基金Liaoning Binhai Laboratory(LBLB-2023-03)Key R&D Program of Shandong Province(2021CXGC010308).
文摘In photolithography,shortening the exposure wavelength from ultraviolet to extreme ultraviolet(EUV,13.5 nm)and soft X-ray region in terms of beyond EUV(BEUV,6.X nm)and water window X-ray(WWX,2.2–4.4 nm)is expected to further miniaturize the technology node down to sub-5 nm level.However,the absorption ability of molecules in these ranges,especially WWX region,is unknown,which should be very important for the utilization of energy.Herein,the molar absorption cross sections of different elements at 2.4 nm of WWX were firstly calculated and compared with the wavelengths of 13.5 nm and 6.7 nm.Based on the absorption cross sections in these ranges and density estimation results from the density-functional theory calculation,the linear absorption coefficients of typical resist materials,including metal-oxy clusters,organic small molecules,polymers,and photoacid generators(PAGs),are evaluated.The analysis suggests that the Zn cluster has higher absorption in BEUV,whereas the Sn cluster has higher absorption in WWX.Doping PAGs with high EUV absorption atoms improves chemically amplified photoresist(CAR)polymer absorption performance.However,for WWX,it is necessary to introduce an absorption layer containing high WWX absorption elements such as Zr,Sn,and Hf to increase the WWX absorption.
文摘For many water quality studies,a data analyst,or modeler, may need to know the spatio-temproal patterns of the data sets and their relationships in both pre-processing and post-processing. Geographic Information System(GIS) can provide an exploratory spat
文摘Palladium-based catalysts have long been considered the benchmark for methane combustion;however,the authentic phase of catalytic active sites remains a subject of ongoing debate.Additionally,challenges like water-poisoning and long-term stability need to be addressed to advance catalyst performance.Herein,we investigate Pd on Co_(3)O_(4) nanorods as a highly effective catalyst for catalytic oxidation of methane,demonstrating long-term stability and water tolerance during a 100-h continuous operation at 350℃.Comprehensive characterizations reveal the presence of an active Pd-oxygen vacancy(Ov)-cobalt interface in Pd/Co_(3)O_(4),which effectively adsorbs molecular O_(2).The absorbed oxygen species on this interface are activated and directly participate in methane combustion.Moreover,near-ambient pressure X-ray photoelectron spectroscopy demonstrates that Pd nanoparticles undergo a rapid phase transition and predominantly remain in the metallic state during the reaction.This behavior is attributed to the electronic metal-support interaction between Pd and Co_(3)O_(4).Furthermore,in situ Fourier transformed infrared spectrum reveals that under reaction conditions,HCO3*species are formed initially and subsequently transformed into formate species,indicating that the formate pathway is the dominant mechanism for CH_(4) oxidation.
基金supported by the Special Funds for the Major State Basic Research Projects(G2011CB610502)the National Natural Science Foundation of China (No.51025104)
文摘The oxidation behavior of alloy 690 exposed to high-temperature and high-pressure steam and water at 280℃ for 1 h was investigated by scanning electron microscopy （SEM）, atomic force microscopy （AFM） and X-ray photoelectron spectroscopy （XPS）. In high-temperature and high-pressure steam, the oxide film is composed of an outermost Ni-rich hydroxides layer, an intermediate layer of hydroxides and oxides enriched in Cr, an inner oxide layer. The film formed in high-temperature water is similar to that in steam, except for missing the Ni-rich hydroxides layer. Samples with different surface finishes （electropolished, mechanically polished, ground, and as-received） were prepared for comparison. A general increase of the oxide thickness with the degree of surface roughness is observed. The equivalent oxide thicknesses lie in the range of 100-200 nm for the as-received samples, 150-250 nm for the samples ground to 400# and 10-20 nm for the samples ground to 1500#, mechanically polished, and electropolished.
基金Project supported by the National Natural Science Foundation of China(62105333)the Key Research Program of the Chinese Academy of Sciences(ZDRW-CN-2021-3)+1 种基金Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2020ZZ114)the Xiamen Medical and Health Guidance Project,China(3502Z20209124)。
文摘In recent years,persistent luminescence materials(PLMs)excited by X-rays and emitting in biological windows have received extensive attention in the field of high-sensitivity bioimaging.Transition metal Mn^(2+)is an ideal emission center,but few studies focus on Mn^(2+)-doped PLMs with X-ray excitation and biological window emission.Here,we report a Mn^(2+)-doped PLM,LiYGeO_(4):Mn^(2+)(LYGM),with excellent biological window persistent luminescence emission.After excitation by UV,LYGM produces a durable biological window of persistent luminescence emission at 660 nm for up to 20 h.More importantly.LYGM can be repeatedly excited by X-rays,resulting in long-term biological window persistent luminescence emission.In addition,we obtain LYGM around 200 nm in diameter by ball milling and centrifugation and improve its biocompatibility by surface modification to apply it to in vivo imaging in mice.After LYGM are injected into mice through the tail vein,in situ excitation of X-rays can be achieved.After the persistent luminescence decays,LYGM can be re-excited for repeated imaging.Therefore,LYGM shows potential prospects for in vivo deep tissue and long-term bioimaging.
基金supported by the Human Resources Development program(no.20124010203180) of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)Grant funded by the Korea government Ministry of Trade,Industry and Energysupported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Science,ICT and Future Planning(NRF-2015R1A2A2A01006856)
文摘Nanostructured iron oxyhydroxide（Fe OOH） thin films have been synthesized using an electrodeposition method on a nickel foam（NF） substrate and effect of air annealing temperature on the catalytic performance is studied. The as-deposited and annealed thin films were characterized by X-ray diffraction（XRD）,X-ray photoelectron spectroscopy（XPS）, field emission scanning electron microscopy（FE-SEM） and linear sweep voltammetry（LSV） to determine their structural, morphological, compositional and electrochemical properties, respectively. The as-deposited nanostructured amorphous Fe OOH thin film is converted into a polycrystalline Fe;O;with hematite crystal structure at a high temperature. The Fe OOH thin film acts as an efficient electrocatalyst for the oxygen evolution reaction（OER） in an alkaline 1 M KOH electrolyte. The film annealed at 200 °C shows high catalytic activity with an onset overpotential of 240 m V with a smaller Tafel slope of 48 m V/dec. Additionally, it needs an overpotential of 290 mV to the drive the current density of 10 m A/cm;and shows good stability in the 1 M KOH electrolyte solution.
基金supported by the National Basic Research Program of China (No.2011CB610502)the National Natural Science Foundation of China for Distinguished Young Scholars (No.51025104).
文摘Multilayer graphene as a potential anti-oxidation barrier to protect nickel foils from oxidation was studied in simulated primary water of pressurized water reactors （PWRs）. The results show that after immersion for 1000 h, the structure of the multilayer graphene remains unchanged and no obvious oxide film formed on the graphene coated nickel foils, indicating multilayer graphene can effectively act as the anti-oxidation barrier to protect the substrate from oxidation and hence can improve the heat transfer efficiency of the substrate in simulated primary water of PWRs.
文摘The penetration of water during water flooding has been observed over many years using several methods. A microfocused X-ray computed tomography scanner can be used to directly observe 3D water flooding in a nondestructive manner. To eliminate the possibility of false images being produced because of X-ray broadening effects, we developed a visualization method by arranging the brightness distribution of all phases involved. Water flooding experiments were conducted using oil-wet and water-wet porous media. The water phase was injected upward into packed glass beads containing an oil phase, and the process was scanned every minute until steady state was reached. Using this scheme, real-time, the water invasion pattern and oil trapping process in clusters of pores and individual pores can be observed clearly. By eliminating false images, the boundary of each phase could be identified with high precision, even in a single pore. Porelevel phenomena, including snap off (which has never before been captured in a real 3D porous medium), piston-like displacement, and the curvature of the interface, were also observed. Direct measurement of the pore throat radius and the contact angle between the wetting and nonwetting phases gave an approximation of the capillary pressure during the piston-like displacement and snap-off processes.
文摘Computer-aided diagnosis(CAD)models exploit artificial intelligence(AI)for chest X-ray(CXR)examination to identify the presence of tuberculosis(TB)and can improve the feasibility and performance of CXR for TB screening and triage.At the same time,CXR interpretation is a time-consuming and subjective process.Furthermore,high resemblance among the radiological patterns of TB and other lung diseases can result in misdiagnosis.Therefore,computer-aided diagnosis(CAD)models using machine learning(ML)and deep learning(DL)can be designed for screening TB accurately.With this motivation,this article develops a Water Strider Optimization with Deep Transfer Learning Enabled Tuberculosis Classification(WSODTL-TBC)model on Chest X-rays(CXR).The presented WSODTL-TBC model aims to detect and classify TB on CXR images.Primarily,the WSODTL-TBC model undergoes image filtering techniques to discard the noise content and U-Net-based image segmentation.Besides,a pre-trained residual network with a two-dimensional convolutional neural network(2D-CNN)model is applied to extract feature vectors.In addition,the WSO algorithm with long short-term memory(LSTM)model was employed for identifying and classifying TB,where the WSO algorithm is applied as a hyperparameter optimizer of the LSTM methodology,showing the novelty of the work.The performance validation of the presented WSODTL-TBC model is carried out on the benchmark dataset,and the outcomes were investigated in many aspects.The experimental development pointed out the betterment of the WSODTL-TBC model over existing algorithms.
基金supported in part by Tokyo Denki University Science Promotion Fund(Q12K-04)
文摘The motion of a lure in water is investigated experimentally and numerically.The lure motion in water of apassing water tank is observed,and the periodic motion is found.From the Fourier analysis,it is found that the frequency with the largest amplitude in the lateral direction depends on the lip width of the lure.To understand the lure dynamics,a numerical simulation of the flow field around the lure is performed.The shape is measured using an X-ray computer tomography and converted into a voxel model.From visualization,it is found that vortex sheds from its lip correspond to the vibration frequency of the lure.
基金supported by the National High Technology Research and Development Program of China(Grant No. 2007AA12Z144)the Professional Projects (Grant Nos.GYHY200706005 and GYHY200906036)the China Meteoro-logical Administration New Technology Promotion Project (GrantNo. CMATG2008Z04)
文摘Satellite retrieval of atmospheric water vapor is intended to further understand the role played by the energy and water cycle to determine the Earth's weather and climate.The algorithm for operational retrieval of total precipitable water (TPW) from the visible and infrared radiometer (VIRR) onboard Fengyun 3A (FY-3A) employs a split window technique for clear sky radiances over land and oceans during both day and night.The retrieved TPW is compared with that from the moderate resolution imaging spectroradiometer (MODIS) onboard the Terra satellite and data from radiosonde observations (RAOB).During the study period,comparisons show that the FY-3A TPW is in general agreement with the gradients and distributions from the Terra TPW.Their zonal mean difference over East Asia is smaller in the daytime than at night,and the main difference occurs in the complex terrain at mid latitude near 30°N.Compared with RAOB,the zonal FY-3A and the Terra TPW have a moist bias at low latitudes and a dry bias at mid and high latitudes;in addition,the FY-3A TPW performs slightly better in zonal mean biases and the diurnal cycle.The temporal variation of the FY-3A and the Terra TPW generally fits the RAOB TPW with the FY-3A more accurate at night while Terra TPW more accurate during the daytime.Comparisons of correlations,root mean square differences and standard deviations indicate that the FY-3A TPW series is more consistent with the RAOB TPW at selected stations.As a result,the FY-3A TPW has some advantages over East Asia in both spatial and temporal dimensions.
基金supported by the Longkou City Science and Technology Research and Development Plan(No.2020KJJH061).
文摘Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the development of aqueous electrolytes to a new height,the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce.Herein,in order to enrich the type of aqueous electrolyte with high operative voltage,tetramethylammonium trifluoromethanesulfonate(TMAOTf)based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile(ACN)co-solvent and LiTFSI co-solute.In view of the coordination effect of ACN and Lit on free water in TMAOTf based WIS electrolyte,the TMAt-Lit-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V.Further coupled with the commercial YP-50F electrodes,TMAt-Lit-AWIS based SCs exhibited wide operative voltage window(2.5 V),long cycling life(45,000 cycles)and good low-temperature performance(99.99%capacitance retention after 2000 cycles at20℃).The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.
文摘This study is designed to investigate the suitability of selected Nigeria clay deposit for clay based ceramic water filters (CWFs). Clay samples were taken from five randomly selected locations in Nigeria Namely: Okpella (Edo<sup>1</sup>) and Ojirami (Edo<sup>2</sup>) in Edo;Ikere in Ekiti state;FUTA in Ondo state and Onibode in Ogun to determine their suitability for clay based ceramic water filters (CWFs). Experimental analysis for linear shrinkage, water absorption, bulk density, compressive strength X-ray diffraction (XRD) and X-ray Fluorescence (XRF) was carried out on each of the clay samples. Test results reveal that all the clays contain high contents of alumina (Al<sub>2</sub>O<sub>3</sub>) and silica (SiO<sub>2</sub>) with minor contents of P<sub>2</sub>O<sub>5</sub>, Fe<sub>2</sub>O<sub>3</sub>, MgO, K<sub>2</sub>O, MnO and TiO<sub>2</sub>. The average crystal sizes of the clay were between 15 and 27 nm. Lattice structure indicates that the sample is Monoclinic and Anorthic. Ceramic water filters (CWFs) were made from a mixture of clay and sawdust at different volume ratios, and processed into test samples. Water absorption, linear shrinkage and compressive strength of the clay based ceramic filters (CWFs), reveal that as the volume ratio of sawdust increases these properties decrease. Flow rate analysis indicates that Edo and Ekiti ceramic water filters (CWFs) have higher flow rates. The research indicates that Edo and Ekiti Clay with specification of some industrial clays shows that the samples can be recommended for use in clay based ceramic water filters production.
基金Supported by the Basic Scientific Fund for National Public Research Institutes of China(Nos.GY02-2011T10,2015P07)the Qingdao Talent Program(No.13-CX-20)+1 种基金the National Natural Science Foundation of China(Nos.31100567,41176061)the National Natural Science Foundation for Creative Groups(No.41521064)
文摘Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not meet the requirements of analysis for time-sensitive samples and/or complicated environmental samples. Since energy-dispersive X-ray spectrometry(EDS) can be used to simultaneously detect multiple elements in a sample, including sulfur, with minimal sample treatment, this technology was applied to detect sulfur-oxidizing bacteria using their high sulfur content within the cell. This article describes the application of scanning electron microscopy imaging coupled with EDS mapping for quick detection of sulfur oxidizers in contaminated environmental water samples, with minimal sample handling. Scanning electron microscopy imaging revealed the existence of dense granules within the bacterial cells, while EDS identified large amounts of sulfur within them. EDS mapping localized the sulfur to these granules. Subsequent 16S rRNA gene sequencing showed that the bacteria detected in our samples belonged to the genus Chromatium, which are sulfur oxidizers. Thus, EDS mapping made it possible to identify sulfur oxidizers in environmental samples based on localized sulfur within their cells, within a short time(within 24 h of sampling). This technique has wide ranging applications for detection of sulfur bacteria in environmental water samples.
基金supported by the National Natural Science Foundation of China(Grant Nos.21471118,21971199,22025106,51202127,91545205,and 91622103)National Key Research and Development Project of China(2018YFA0704000)+1 种基金Natural Science Foundation of Hubei Province(2016CFB382)Fundamental Research Funds for the Central Universities(2042017kf0227,2042019kf0205)。
文摘Atmospheric water harvesting offers a powerful and promising solution to address the problem of global freshwater scarcity.In the past decade,significant progress has been achieved in utilizing hydrolytically stable metal-organic frameworks as recyclable water-sorbent materials under low relative humidity,especially in those arid areas.Recently,Yaghi's group has employed a combined crystallographic and theoretical technique to decipher the water filling mechanism in MOF-303,where the polar organic linkers rather than the inorganic units of MOF are demonstrated as the key factor.Hence,the hydrophilic strength of the water-binding pocket in MOFs can be optimized through the approach of multivariate modulations,resulting in enhanced water harvesting properties.
基金supported by the National Magnetic Confinement Fusion Program of China(No.2008GB109003)
文摘Beryllium （Be） window is a key component of the ITER radial X-ray camera （RXC）. The Be window presented in this paper has a mechanical clamping structure, the thickness of the Be foil is 80 μm, and the X-ray threshold of the 80 μm Be foil is 1.24 keV. A honeycomb support is designed and applied to strengthen the Be foil to prevent it from breakage when it is exposed to 1 atm perssure. Based on analysis results, the hole diameter of the support is chosen as 4 mm. A metal seal is used to isolate the vacuum on two sides of the Be window, the hollow metal sealing ring ensures the He leakage rate of the Be window being lower than 6× 10^-1 Pa.m^3.s^-1. Baking （240 ℃, 2 h） and vibration（3.3 Hz, 2 h） tests are carried out and the feasibility of the Be window＇s sealant in these situations is tested. The Be window has good stability that can save maintenance cost as well as enhancing the safety of the RXC.
文摘The effect of (Pt-loaded)TiO2 crystallite diameter (i.e. Scherrer size) on the photocatalytic water splitting rate was investigated. (Pt-loaded)TiO2 powders with a wide range of crystallite diameters from about 16 to 45 nm with a blank region between about 23 and 41 nm were prepared by various annealing processes from an identical TiO2 powder. Water splitting experiments with these powders were carried out with methanol as an oxidizing sacrificial agent. It was found that the photocatalytic water splitting rate was sensitively affected by the crystallite diameter of the (Pt-loaded)TiO2 powder. More concretely, similar steep improvements of photocatalytic water splitting rates from around 15 and a little over 2 to about 30 μmol·m-2hr-1?were obtained in the two (Pt-loaded)TiO2 crystallite diameters ranging from 16 to 23 and from 41 to 45 nm, respectively.
