ADC distribution network is an effective solution for increasing renewable energy utilization with distinct benefits,such as high efficiency and easy control.However,a sudden increase in the current after the occurren...ADC distribution network is an effective solution for increasing renewable energy utilization with distinct benefits,such as high efficiency and easy control.However,a sudden increase in the current after the occurrence of faults in the network may adversely affect network stability.This study proposes an artificial neural network(ANN)-based fault detection and protection method for DC distribution networks.The ANN is applied to a classifier for different faults ontheDC line.The backpropagationneuralnetwork is used to predict the line current,and the fault detection threshold is obtained on the basis of the difference between the predicted current and the actual current.The proposed method only uses local signals,with no requirement of a strict communication link.Simulation experiments are conducted for the proposed algorithm on a two-terminal DC distribution network modeled in the PSCAD/EMTDC and developed on the MATLAB platform.The results confirm that the proposed method can accurately detect and classify line faults within a few milliseconds and is not affected by fault locations,fault resistance,noise,and communication delay.展开更多
Objective:Cassiae Semen(CS,Juemingzi in Chinese)has been used for thousands of years in ancient Chinese history for relieving constipation,improving liver function as well as preventing myopia.Here we aimed to elucida...Objective:Cassiae Semen(CS,Juemingzi in Chinese)has been used for thousands of years in ancient Chinese history for relieving constipation,improving liver function as well as preventing myopia.Here we aimed to elucidate the anti-steatosis effect and underlying mechanism of CS against non-alcoholic fatty liver disease(NAFLD).Methods:High-performance liquid chromatography(HPLC)was used to identify the major components of CS water extract.Mice were fed with a high-fat and sugar-water(HFSW)diet to induce hepatic steatosis and then treated with CS.The anti-NAFLD effect was determined by measuring serum biomarkers and histopathology staining.Additionally,the effects of CS on cell viability and lipid metabolism in oleic acid and palmitic acid(OAPA)-treated HepG2 cells were measured.The expression of essential genes and proteins involved in lipid metabolism and autophagy signalings were measured to uncover the underlying mechanism.Results:Five compounds,including aurantio-obtusin,rubrofusarin gentiobioside,cassiaside C,emodin and rhein were simultaneously identified in CS extract.CS not only improved the diet-induced hepatic steatosis in vivo,as indicated by decreased number and size of lipid droplets,hepatic and serum triglycerides(TG)levels,but also markedly attenuated the OAPA-induced lipid accumulation in hepatocytes.These lipid-lowering effects induced by CS were largely dependent on the inhibition of fatty acid synthase(FASN)and the activation of autophagy-related signaling,including AMP-activated protein kinase(AMPK),light chain 3-II(LC3-II)/LC3-1 and autophagy-related gene5(ATG5).Conclusion:Our study suggested that CS effectively protected liver steatosis via decreasing FASN-related fatty acid synthesis and activating AMPK-mediated autophagy,which might become a promising therapeutic strategy for relieving NAFLD.展开更多
In this work,(-201)β-Ga2O3 films are grown on GaN substrate by metal organic chemical vapor deposition(MOCVD).It is revealed that theβ-Ga2O3 film grown on GaN possesses superior crystal quality,material homogeneity ...In this work,(-201)β-Ga2O3 films are grown on GaN substrate by metal organic chemical vapor deposition(MOCVD).It is revealed that theβ-Ga2O3 film grown on GaN possesses superior crystal quality,material homogeneity and surface morphology than the results of common heteroepitaxialβ-Ga2O3 film based on sapphire substrate.Further,the relevance between the crystal quality of epitaxialβ-Ga2O3 film and theβ-Ga2O3/GaN interface behavior is investigated.Transmission electron microscopy result indicates that the interface atom refactoring phenomenon is beneficial to relieve the mismatch strain and improve the crystal quality of subsequentβ-Ga2O3 film.Moreover,the energy band structure ofβ-Ga2O3/GaN heterostructure grown by MOCVD is investigated by X-ray photoelectron spectroscopy and a large conduction band offset of 0.89 eV is obtained.The results in this work not only convincingly demonstrate the advantages ofβ-Ga2O3 films grown on GaN substrate,but also show the great application potential of MOCVDβ-Ga2O3/GaN heterostructures in microelectronic applications.展开更多
Various single-ring aromatic compounds in water sources are of great concern due to its hazardous impact on the environment and human health.The fluorescence excitation-emission matrix(EEMs)spectrophotometry is a usef...Various single-ring aromatic compounds in water sources are of great concern due to its hazardous impact on the environment and human health.The fluorescence excitation-emission matrix(EEMs)spectrophotometry is a useftil method to identify organic pollutants in water.This study provides a detailed insight into the fluorescence properties of the 14 selected toxic single-ring aromatic compounds by experimental and theoretical analysis.The theoretical analysis were done with Time-Dependent Density Functional Theory(TD-DFT)and B3LYP/6-31G(d,p)basis set,whereas,Polarizable Continuum Model(PCM)was used to consider water as solvent.The selected compounds displayed their own specific excitation-emission(Ex/Em)wavelengths region,at Ex<280 nm and Em<340 nm,respectively.Whereas the theoretical Ex/Em was observed as.Ex at 240 nm-260 nm and Em at 255 nm-300 nm.Aniline as a strong aromatic base has longer Em(340 nm)than alkyl,carbonyl,and halogens substituted benzenes.The lone pair of electrons at amide substituent serves as a 7r-electron contributor into the aromatic ring,hence increasing the stability and transition energy,which results in longer emission and low quantum yield for the aniline.The fluorescence of halogenated benzenes illustrates an increase in the HOMO-LUMO energy gap and a decrease in quantum yield associated with atomic size(F>Cl>Br>I).In this study the theoretical results are in line with experimental ones.The understanding of fluorescence and photophysical properties are of great importance in the identification of these compounds in the water.展开更多
The feasibility of simultaneous water recovery,salt separation and effective descaling of hypersaline brine was investigated by diisopropylamine(DIPA)-based directional solvent extraction(DSE),using diluted/concentrat...The feasibility of simultaneous water recovery,salt separation and effective descaling of hypersaline brine was investigated by diisopropylamine(DIPA)-based directional solvent extraction(DSE),using diluted/concentrated seawater with initial saline concentration range of 12–237 g/L at extraction temperatures of 5 and 15°C,respectively.The water recovery shows an obvious boundary at saline concentration of 115 g/L under dual effect of specific water extraction efficiency and extraction cycles.High Cl–ion concentration in product water is in sharp contrast to the nearly complete removal of SO_(4)^(2–)and hardness ions,indicating that DIPA-based DSE process indeed achieved efficient separation and purification of Cl–ion from hypersaline brines.Especially,the radical precipitation of Mg^(2+)and Ca^(2+)ions in form of Mg(OH)_(2)and CaCO_(3)demonstrates effective descaling potential,although it leads to more DIPA residues in dewatered raffinate than product water.Moreover,an exponential correlation between the Cl–removal efficiency and specific water extraction efficiency further reveals the intrinsic relationship of water extraction process and transfer of Cl–ion to the product water.Overall,the study provides a novel approach for integrating the water recovery and separation of Cl–ion from ultra-high-salinity brines with radical precipitation of Mg^(2+)and Ca2+ions in one step.展开更多
基金supported by Key Natural Science Research Projects of Colleges and Universities in Anhui Province(No.2022AH051831).
文摘ADC distribution network is an effective solution for increasing renewable energy utilization with distinct benefits,such as high efficiency and easy control.However,a sudden increase in the current after the occurrence of faults in the network may adversely affect network stability.This study proposes an artificial neural network(ANN)-based fault detection and protection method for DC distribution networks.The ANN is applied to a classifier for different faults ontheDC line.The backpropagationneuralnetwork is used to predict the line current,and the fault detection threshold is obtained on the basis of the difference between the predicted current and the actual current.The proposed method only uses local signals,with no requirement of a strict communication link.Simulation experiments are conducted for the proposed algorithm on a two-terminal DC distribution network modeled in the PSCAD/EMTDC and developed on the MATLAB platform.The results confirm that the proposed method can accurately detect and classify line faults within a few milliseconds and is not affected by fault locations,fault resistance,noise,and communication delay.
基金supported by the Beijing Municipal Science&Technology Commission(No.7212174 to XL)National Natural Science Foundation of China(No.82004045 to XL)+2 种基金Beijing Nova Program of Science&Technology(No.Z191100001119088 to XL)the Young Talents Promotion Project of China Association of Traditional Chinese Medicine(No.2020-QNRC2-01 to XL)Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine(No.ZYYCXTD-C-202006 to XL)。
文摘Objective:Cassiae Semen(CS,Juemingzi in Chinese)has been used for thousands of years in ancient Chinese history for relieving constipation,improving liver function as well as preventing myopia.Here we aimed to elucidate the anti-steatosis effect and underlying mechanism of CS against non-alcoholic fatty liver disease(NAFLD).Methods:High-performance liquid chromatography(HPLC)was used to identify the major components of CS water extract.Mice were fed with a high-fat and sugar-water(HFSW)diet to induce hepatic steatosis and then treated with CS.The anti-NAFLD effect was determined by measuring serum biomarkers and histopathology staining.Additionally,the effects of CS on cell viability and lipid metabolism in oleic acid and palmitic acid(OAPA)-treated HepG2 cells were measured.The expression of essential genes and proteins involved in lipid metabolism and autophagy signalings were measured to uncover the underlying mechanism.Results:Five compounds,including aurantio-obtusin,rubrofusarin gentiobioside,cassiaside C,emodin and rhein were simultaneously identified in CS extract.CS not only improved the diet-induced hepatic steatosis in vivo,as indicated by decreased number and size of lipid droplets,hepatic and serum triglycerides(TG)levels,but also markedly attenuated the OAPA-induced lipid accumulation in hepatocytes.These lipid-lowering effects induced by CS were largely dependent on the inhibition of fatty acid synthase(FASN)and the activation of autophagy-related signaling,including AMP-activated protein kinase(AMPK),light chain 3-II(LC3-II)/LC3-1 and autophagy-related gene5(ATG5).Conclusion:Our study suggested that CS effectively protected liver steatosis via decreasing FASN-related fatty acid synthesis and activating AMPK-mediated autophagy,which might become a promising therapeutic strategy for relieving NAFLD.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.JB181108)the National Natural Science Foundation of China(Grant No.61904139)the Science and Technology Program of Guangzhou(Grant No.201904010457)。
文摘In this work,(-201)β-Ga2O3 films are grown on GaN substrate by metal organic chemical vapor deposition(MOCVD).It is revealed that theβ-Ga2O3 film grown on GaN possesses superior crystal quality,material homogeneity and surface morphology than the results of common heteroepitaxialβ-Ga2O3 film based on sapphire substrate.Further,the relevance between the crystal quality of epitaxialβ-Ga2O3 film and theβ-Ga2O3/GaN interface behavior is investigated.Transmission electron microscopy result indicates that the interface atom refactoring phenomenon is beneficial to relieve the mismatch strain and improve the crystal quality of subsequentβ-Ga2O3 film.Moreover,the energy band structure ofβ-Ga2O3/GaN heterostructure grown by MOCVD is investigated by X-ray photoelectron spectroscopy and a large conduction band offset of 0.89 eV is obtained.The results in this work not only convincingly demonstrate the advantages ofβ-Ga2O3 films grown on GaN substrate,but also show the great application potential of MOCVDβ-Ga2O3/GaN heterostructures in microelectronic applications.
基金We are grateful for the financial support provided by the National Major Scientific Instrument Equipment Development Project(No.2017YFF0408500).
文摘Various single-ring aromatic compounds in water sources are of great concern due to its hazardous impact on the environment and human health.The fluorescence excitation-emission matrix(EEMs)spectrophotometry is a useftil method to identify organic pollutants in water.This study provides a detailed insight into the fluorescence properties of the 14 selected toxic single-ring aromatic compounds by experimental and theoretical analysis.The theoretical analysis were done with Time-Dependent Density Functional Theory(TD-DFT)and B3LYP/6-31G(d,p)basis set,whereas,Polarizable Continuum Model(PCM)was used to consider water as solvent.The selected compounds displayed their own specific excitation-emission(Ex/Em)wavelengths region,at Ex<280 nm and Em<340 nm,respectively.Whereas the theoretical Ex/Em was observed as.Ex at 240 nm-260 nm and Em at 255 nm-300 nm.Aniline as a strong aromatic base has longer Em(340 nm)than alkyl,carbonyl,and halogens substituted benzenes.The lone pair of electrons at amide substituent serves as a 7r-electron contributor into the aromatic ring,hence increasing the stability and transition energy,which results in longer emission and low quantum yield for the aniline.The fluorescence of halogenated benzenes illustrates an increase in the HOMO-LUMO energy gap and a decrease in quantum yield associated with atomic size(F>Cl>Br>I).In this study the theoretical results are in line with experimental ones.The understanding of fluorescence and photophysical properties are of great importance in the identification of these compounds in the water.
基金supported financially by a grant from Shougang Group Co.,Ltd.,China(No.K202200134Y).
文摘The feasibility of simultaneous water recovery,salt separation and effective descaling of hypersaline brine was investigated by diisopropylamine(DIPA)-based directional solvent extraction(DSE),using diluted/concentrated seawater with initial saline concentration range of 12–237 g/L at extraction temperatures of 5 and 15°C,respectively.The water recovery shows an obvious boundary at saline concentration of 115 g/L under dual effect of specific water extraction efficiency and extraction cycles.High Cl–ion concentration in product water is in sharp contrast to the nearly complete removal of SO_(4)^(2–)and hardness ions,indicating that DIPA-based DSE process indeed achieved efficient separation and purification of Cl–ion from hypersaline brines.Especially,the radical precipitation of Mg^(2+)and Ca^(2+)ions in form of Mg(OH)_(2)and CaCO_(3)demonstrates effective descaling potential,although it leads to more DIPA residues in dewatered raffinate than product water.Moreover,an exponential correlation between the Cl–removal efficiency and specific water extraction efficiency further reveals the intrinsic relationship of water extraction process and transfer of Cl–ion to the product water.Overall,the study provides a novel approach for integrating the water recovery and separation of Cl–ion from ultra-high-salinity brines with radical precipitation of Mg^(2+)and Ca2+ions in one step.
