Ice cover on transmission lines is a significant issue that affects the safe operation of the power system.Accurate calculation of the thickness of wire icing can effectively prevent economic losses caused by ice disa...Ice cover on transmission lines is a significant issue that affects the safe operation of the power system.Accurate calculation of the thickness of wire icing can effectively prevent economic losses caused by ice disasters and reduce the impact of power outages on residents.However,under extreme weather conditions,strong instantaneous wind can cause tension sensors to fail,resulting in significant errors in the calculation of icing thickness in traditional mechanics-based models.In this paper,we propose a dynamic prediction model of wire icing thickness that can adapt to extreme weather environments.The model expands scarce raw data by the Wasserstein Generative Adversarial Network with Gradient Penalty(WGAN-GP)technique,records historical environmental information by a recurrent neural network,and evaluates the ice warning levels by a classifier.At each time point,the model diagnoses whether the current sensor failure is due to icing or strong winds.If it is determined that the wire is covered with ice,the icing thickness will be calculated after the wind-induced tension is removed from the ice-wind coupling tension.Our new model was evaluated using data from the power grid in an area with extreme weather.The results show that the proposed model has significant improvements in accuracy compared with traditional models.展开更多
The Tbx family is first known through the study of their functions in the body and limbs,and its members Tbx4 and Tbx5 genes are important factors in determining the characteristics of the appendages.Pampus argenteus ...The Tbx family is first known through the study of their functions in the body and limbs,and its members Tbx4 and Tbx5 genes are important factors in determining the characteristics of the appendages.Pampus argenteus is one of the important economical marine fishes widely distributed in offshore areas.Therefore,it is necessary to study the role of Tbx family genes in the deletion of pelvic fin in P.argenteus.In this study,we cloned Tbx4 and Tbx5 cDNA sequence of P.argenteus(GenBank:MH709128 and MH712458).The Western blot and real time PCR were used to detect the expressions of Tbx4 and Tbx5 in different developmental stages and tissues of P.argenteus.In addition,whole-mount in-situ hybridization was used to study the localization of Tbx4 and Tbx5 genes in different developmental stages of P.argenteus.Results show that the translation of Tbx4 mRNA was inhibited during the critical period of pelvic fin development.Among different tissues,Tbx4 protein levels were the lowest in the abdominal epithelium,and even lower than that in the pectoral fin,suggesting that the protein expression was also inhibited in the abdominal epithelium of adult P.argenteus.Therefore,the results indicated that upstream genes regulation led to the key stage-specific and low expression of Tbx4 during pelvic fin development and in the abdominal epithelium.展开更多
Matrix Padé approximation is a widely used method for computing matrix functions. In this paper, we apply matrix Padé-type approximation instead of typical Padé approximation to computing the matrix exp...Matrix Padé approximation is a widely used method for computing matrix functions. In this paper, we apply matrix Padé-type approximation instead of typical Padé approximation to computing the matrix exponential. In our approach the scaling and squaring method is also used to make the approximant more accurate. We present two algorithms for computing and for computing with many espectively. Numerical experiments comparing the proposed method with other existing methods which are MATLAB’s functions expm and funm show that our approach is also very effective and reliable for computing the matrix exponential . Moreover, there are two main advantages of our approach. One is that there is no inverse of a matrix required in this method. The other is that this method is more convenient when computing for a fixed matrix A with many t ≥ 0.展开更多
In this paper, the adsorption and storage of hydrogen on calcium-decorated, boron-doped bilayer graphene was investigated using first principles calculation. The calcium-decorated bilayer graphene was investigated and...In this paper, the adsorption and storage of hydrogen on calcium-decorated, boron-doped bilayer graphene was investigated using first principles calculation. The calcium-decorated bilayer graphene was investigated and it was shown that the binding energy of H2 molecule adsorbed on the calcium-decorated bilayer graphene is −0.02 eV and the energy does not belong to reversible usage range of −0.2 - −0.6 eV. Substitutional boron doping can improve the adsorption energy of Ca to bilayer graphene with the empty pz orbital of boron atoms. Our calculations show that calcium atoms can be solidly adsorbed on the interlayer (Ca/B/Graphene) and outerlayer (2Ca/B/Graphene and 3Ca/B/Graphene) of B-doped bilayer graphene. Hydrogen molecule binds with Ca/B/Graphene, 2Ca/B/Graphene and 3Ca/B/Graphene system with an energy that belongs to reversible usage range of −0.2 - −0.6 eV. The overlap between Ca 3d and H2σ orbitals just below the Fermi energy demonstrates the charge transfer between the Ca atom and the H atom and the role of hybridization of the 3d orbita of Ca with the σ orbitals of H2 in efficient adsorption of hydrogen molecules. The charge from hydrogen bonding orbital transfers to empty 3d orbitals of the Ca atom, and then from the 3d orbitals of the Ca atom donated to H2σ* antibonding orbital. Hydrogen moleculars can be adsorbed on the interlayer and outerlayer of Ca-decorated B-doped bilayer graphene.展开更多
To explore the formation process and mechanism of organic matter and organic-mineral complex under humification and mineralization conditions, a series of samples including humic acid, kaolin, and humic acid-kaolin co...To explore the formation process and mechanism of organic matter and organic-mineral complex under humification and mineralization conditions, a series of samples including humic acid, kaolin, and humic acid-kaolin complex were prepared using a subcritical water treatment method（SWT） under specific temperature, pressure and reaction time conditions. HA was used as a surrogate for natural organic matter because it has a similar abundant pore structure,variety of carbon types, and chemical components. These samples were used in carbamazepine（CBZ） sorption experiments and characterized by a variety of techniques. The polymerization of humic acid under the conditions of increased temperature and pressure resulted in an increase in specific surface area and molecular quantity. In addition, the degree of aromaticity rose from59.52% to 70.90%. These changes were consistent with the transformation from ‘soft carbon＇ to‘hard carbon＇ that occurs in nature. The results of sorption experiments confirmed the interaction between humic acid and kaolin from the difference between the predicted and actual Qevalues. The conceptual model of humic acid-kaolin complex could be deduced and described as follows. Firstly, the aromatic components of humic acid preferentially combine with kaolin through the intercalation effect, which protects them from the treatment effects.Next, the free carboxyl groups and small aliphatic components of humic acid interact on the surface of kaolin, and these soft species transform into dense carbon through cyclization and polymerization. As a result, humic acid-kaolin complex with a mineral core and dense outer carbonaceous patches were formed.展开更多
Polycyclic aromatic hydrocarbons(PAHs)are major organic pollutants in soil.It is known that they are released to the atmosphere by wind via dust aerosol generation.However,it remains unclear how these pollutants are t...Polycyclic aromatic hydrocarbons(PAHs)are major organic pollutants in soil.It is known that they are released to the atmosphere by wind via dust aerosol generation.However,it remains unclear how these pollutants are transferred through the air/soil interface.In this study,dust aerosols were generated in the laboratory using soils(sandy loam and loam)with various physicochemical properties.The PAH concentrations of these soils and their generated dust aerosol were measured,showing that the enrichment factors(EFs)of PAHs were affected by soil texture,PAH contamination level,molecular weight of PAH species and aerosol sizes.The PAHs with higher EFs(6.24–123.35 in dust PM_(2.5);7.02–47.65 in dust PM_(10))usually had high molecular weights with more than four aromatic rings.In addition,the positive correlation between EFs of PAHs and the total OCaerosol content of dust aerosol in different particle sizes was also statistically significant(r=0.440,P<0.05).This work provides insights into the relationship between atmospheric PAHs and the contaminated soils and the transfer process of PAHs through the soil-air interface.展开更多
How horizontal gene transfer(HGT)has contributed to the evolution of animals and plants remains a major puzzle.Despite recent progress,defining the overall scale and pattern of HGT events in land plants has been large...How horizontal gene transfer(HGT)has contributed to the evolution of animals and plants remains a major puzzle.Despite recent progress,defining the overall scale and pattern of HGT events in land plants has been largely elusive.In this study,we performed systematic analyses for acquired genes in different plant groups and throughout land plant evolution.We found that relatively recent HGT events occurred in char-ophytes and all major land plant groups,but their frequency declined rapidly in seed plants.Two major ep-isodes of HGT events occurred in land plant evolution,corresponding to the early evolution of strepto-phytes and the origin of land plants,respectively.Importantly,a vast majority of the genes acquired in the two episodes have been retained in descendant groups,affecting numerous activities and processes of land plants.We analyzed some of the acquired genes involved in stress responses,ion and metabolite transport,growth and development,and specialized metabolism,and further assessed the cumulative ef-fects of HGT in land plants.展开更多
To the Editor:Helicobacter pylori(H.pylori)is estimated to affect approximately half of the world’s population,especially in most developing countries.[1]Eradication of H.pylori has been proven to promote peptic ulce...To the Editor:Helicobacter pylori(H.pylori)is estimated to affect approximately half of the world’s population,especially in most developing countries.[1]Eradication of H.pylori has been proven to promote peptic ulcer healing and reduce the incidence of gastric cancer.Previous studies have reported that the northwest region of China has a high H.pylori infection rate of 51.8%.[2]However,the H.pylori eradication rate is declining every year,primarily due to increasing antibiotic resistance,notably clarithromycin,[3]and various other factors may also impact H.pylori eradication.Consequently,this study was conducted to elaborate on the situation of H.pylori eradication in Northwest China and evaluate the related risk factors for eradication failure to explore possible solutions.展开更多
基金supported by the Science and Technology Project of State Grid Corporation of China(SGXJDK00GYJS2400035).
文摘Ice cover on transmission lines is a significant issue that affects the safe operation of the power system.Accurate calculation of the thickness of wire icing can effectively prevent economic losses caused by ice disasters and reduce the impact of power outages on residents.However,under extreme weather conditions,strong instantaneous wind can cause tension sensors to fail,resulting in significant errors in the calculation of icing thickness in traditional mechanics-based models.In this paper,we propose a dynamic prediction model of wire icing thickness that can adapt to extreme weather environments.The model expands scarce raw data by the Wasserstein Generative Adversarial Network with Gradient Penalty(WGAN-GP)technique,records historical environmental information by a recurrent neural network,and evaluates the ice warning levels by a classifier.At each time point,the model diagnoses whether the current sensor failure is due to icing or strong winds.If it is determined that the wire is covered with ice,the icing thickness will be calculated after the wind-induced tension is removed from the ice-wind coupling tension.Our new model was evaluated using data from the power grid in an area with extreme weather.The results show that the proposed model has significant improvements in accuracy compared with traditional models.
基金Supported by the National Natural Science Foundation of China(Nos.31872586,42076118)the Major Project of Science,Technology and Innovation 2025 in Ningbo City(No.2021Z003)the K.C.Wong Magna Fund in Ningbo University。
文摘The Tbx family is first known through the study of their functions in the body and limbs,and its members Tbx4 and Tbx5 genes are important factors in determining the characteristics of the appendages.Pampus argenteus is one of the important economical marine fishes widely distributed in offshore areas.Therefore,it is necessary to study the role of Tbx family genes in the deletion of pelvic fin in P.argenteus.In this study,we cloned Tbx4 and Tbx5 cDNA sequence of P.argenteus(GenBank:MH709128 and MH712458).The Western blot and real time PCR were used to detect the expressions of Tbx4 and Tbx5 in different developmental stages and tissues of P.argenteus.In addition,whole-mount in-situ hybridization was used to study the localization of Tbx4 and Tbx5 genes in different developmental stages of P.argenteus.Results show that the translation of Tbx4 mRNA was inhibited during the critical period of pelvic fin development.Among different tissues,Tbx4 protein levels were the lowest in the abdominal epithelium,and even lower than that in the pectoral fin,suggesting that the protein expression was also inhibited in the abdominal epithelium of adult P.argenteus.Therefore,the results indicated that upstream genes regulation led to the key stage-specific and low expression of Tbx4 during pelvic fin development and in the abdominal epithelium.
文摘Matrix Padé approximation is a widely used method for computing matrix functions. In this paper, we apply matrix Padé-type approximation instead of typical Padé approximation to computing the matrix exponential. In our approach the scaling and squaring method is also used to make the approximant more accurate. We present two algorithms for computing and for computing with many espectively. Numerical experiments comparing the proposed method with other existing methods which are MATLAB’s functions expm and funm show that our approach is also very effective and reliable for computing the matrix exponential . Moreover, there are two main advantages of our approach. One is that there is no inverse of a matrix required in this method. The other is that this method is more convenient when computing for a fixed matrix A with many t ≥ 0.
文摘In this paper, the adsorption and storage of hydrogen on calcium-decorated, boron-doped bilayer graphene was investigated using first principles calculation. The calcium-decorated bilayer graphene was investigated and it was shown that the binding energy of H2 molecule adsorbed on the calcium-decorated bilayer graphene is −0.02 eV and the energy does not belong to reversible usage range of −0.2 - −0.6 eV. Substitutional boron doping can improve the adsorption energy of Ca to bilayer graphene with the empty pz orbital of boron atoms. Our calculations show that calcium atoms can be solidly adsorbed on the interlayer (Ca/B/Graphene) and outerlayer (2Ca/B/Graphene and 3Ca/B/Graphene) of B-doped bilayer graphene. Hydrogen molecule binds with Ca/B/Graphene, 2Ca/B/Graphene and 3Ca/B/Graphene system with an energy that belongs to reversible usage range of −0.2 - −0.6 eV. The overlap between Ca 3d and H2σ orbitals just below the Fermi energy demonstrates the charge transfer between the Ca atom and the H atom and the role of hybridization of the 3d orbita of Ca with the σ orbitals of H2 in efficient adsorption of hydrogen molecules. The charge from hydrogen bonding orbital transfers to empty 3d orbitals of the Ca atom, and then from the 3d orbitals of the Ca atom donated to H2σ* antibonding orbital. Hydrogen moleculars can be adsorbed on the interlayer and outerlayer of Ca-decorated B-doped bilayer graphene.
基金supported by the Fundamental Research Funds for the Outstanding Teachers in the Central Universities(No.35832015023)
文摘To explore the formation process and mechanism of organic matter and organic-mineral complex under humification and mineralization conditions, a series of samples including humic acid, kaolin, and humic acid-kaolin complex were prepared using a subcritical water treatment method（SWT） under specific temperature, pressure and reaction time conditions. HA was used as a surrogate for natural organic matter because it has a similar abundant pore structure,variety of carbon types, and chemical components. These samples were used in carbamazepine（CBZ） sorption experiments and characterized by a variety of techniques. The polymerization of humic acid under the conditions of increased temperature and pressure resulted in an increase in specific surface area and molecular quantity. In addition, the degree of aromaticity rose from59.52% to 70.90%. These changes were consistent with the transformation from ‘soft carbon＇ to‘hard carbon＇ that occurs in nature. The results of sorption experiments confirmed the interaction between humic acid and kaolin from the difference between the predicted and actual Qevalues. The conceptual model of humic acid-kaolin complex could be deduced and described as follows. Firstly, the aromatic components of humic acid preferentially combine with kaolin through the intercalation effect, which protects them from the treatment effects.Next, the free carboxyl groups and small aliphatic components of humic acid interact on the surface of kaolin, and these soft species transform into dense carbon through cyclization and polymerization. As a result, humic acid-kaolin complex with a mineral core and dense outer carbonaceous patches were formed.
基金supported by the National Natural Science Foundation of China(Nos.42077193,21906024,and 92044301)the Shanghai Natural Science Foundation(China)(No.19ZR1404000)。
文摘Polycyclic aromatic hydrocarbons(PAHs)are major organic pollutants in soil.It is known that they are released to the atmosphere by wind via dust aerosol generation.However,it remains unclear how these pollutants are transferred through the air/soil interface.In this study,dust aerosols were generated in the laboratory using soils(sandy loam and loam)with various physicochemical properties.The PAH concentrations of these soils and their generated dust aerosol were measured,showing that the enrichment factors(EFs)of PAHs were affected by soil texture,PAH contamination level,molecular weight of PAH species and aerosol sizes.The PAHs with higher EFs(6.24–123.35 in dust PM_(2.5);7.02–47.65 in dust PM_(10))usually had high molecular weights with more than four aromatic rings.In addition,the positive correlation between EFs of PAHs and the total OCaerosol content of dust aerosol in different particle sizes was also statistically significant(r=0.440,P<0.05).This work provides insights into the relationship between atmospheric PAHs and the contaminated soils and the transfer process of PAHs through the soil-air interface.
基金This work is funded in part by the National Natural Science Foundation of China(31970248 and 32000176).
文摘How horizontal gene transfer(HGT)has contributed to the evolution of animals and plants remains a major puzzle.Despite recent progress,defining the overall scale and pattern of HGT events in land plants has been largely elusive.In this study,we performed systematic analyses for acquired genes in different plant groups and throughout land plant evolution.We found that relatively recent HGT events occurred in char-ophytes and all major land plant groups,but their frequency declined rapidly in seed plants.Two major ep-isodes of HGT events occurred in land plant evolution,corresponding to the early evolution of strepto-phytes and the origin of land plants,respectively.Importantly,a vast majority of the genes acquired in the two episodes have been retained in descendant groups,affecting numerous activities and processes of land plants.We analyzed some of the acquired genes involved in stress responses,ion and metabolite transport,growth and development,and specialized metabolism,and further assessed the cumulative ef-fects of HGT in land plants.
基金supported by grants from the National Natural Science Foundation of China(Nos.82170560 and 81873554).
文摘To the Editor:Helicobacter pylori(H.pylori)is estimated to affect approximately half of the world’s population,especially in most developing countries.[1]Eradication of H.pylori has been proven to promote peptic ulcer healing and reduce the incidence of gastric cancer.Previous studies have reported that the northwest region of China has a high H.pylori infection rate of 51.8%.[2]However,the H.pylori eradication rate is declining every year,primarily due to increasing antibiotic resistance,notably clarithromycin,[3]and various other factors may also impact H.pylori eradication.Consequently,this study was conducted to elaborate on the situation of H.pylori eradication in Northwest China and evaluate the related risk factors for eradication failure to explore possible solutions.
