One-third of patients with autoimmune hepatitis(AIH)have cirrhosis at the time of diagnosis.The relevance of these variables,although unknown,is believed to be critical in AIH because of suspected interactions between...One-third of patients with autoimmune hepatitis(AIH)have cirrhosis at the time of diagnosis.The relevance of these variables,although unknown,is believed to be critical in AIH because of suspected interactions between the gut microbiome and genetic factors.Dysbiosis of the gut flora and elevated polymeric immunoglobulin receptor(pIgR)levels have been observed in both patients and mouse models.Moreover,there is a direct relationship between pIgR expression and transaminase levels in patients with AIH.In this study,we aimed to explore how pIgR influences the secretion of regenerating islet-derived 3 beta(Reg3b)and the flora composition in AIH using in vivo experiments involving patients with AIH and a concanavalin A-induced mouse model of AIH.Reg3b expression was reduced in pIgR gene(Pigr)-knockout mice compared to that in wild-type mice,leading to increased microbiota disruption.Conversely,exogenous pIgR supplementation increased Reg3b expression and maintained microbiota homeostasis.RNA sequencing revealed the participation of the interleukin(IL)-17 signaling pathway in the regulation of Reg3b through pIgR.Furthermore,the introduction of external pIgR could not restore the imbalance in gut microbiota in AIH,and the decrease in Reg3b expression was not apparent following the inhibition of signal transducer and activator of transcription 3(STAT3).In this study,pIgR facilitated the upregulation of Reg3b via the STAT3 pathway,which plays a crucial role in preserving the balance of the intestinal microbiota in AIH.Through this research,we discovered new molecular targets that can be used for the diagnosis and treatment of AIH.展开更多
The application of artificial intelligence technology in Internet of Vehicles(lov)has attracted great research interests with the goal of enabling smart transportation and traffic management.Meanwhile,concerns have be...The application of artificial intelligence technology in Internet of Vehicles(lov)has attracted great research interests with the goal of enabling smart transportation and traffic management.Meanwhile,concerns have been raised over the security and privacy of the tons of traffic and vehicle data.In this regard,Federated Learning(FL)with privacy protection features is considered a highly promising solution.However,in the FL process,the server side may take advantage of its dominant role in model aggregation to steal sensitive information of users,while the client side may also upload malicious data to compromise the training of the global model.Most existing privacy-preserving FL schemes in IoV fail to deal with threats from both of these two sides at the same time.In this paper,we propose a Blockchain based Privacy-preserving Federated Learning scheme named BPFL,which uses blockchain as the underlying distributed framework of FL.We improve the Multi-Krum technology and combine it with the homomorphic encryption to achieve ciphertext-level model aggregation and model filtering,which can enable the verifiability of the local models while achieving privacy-preservation.Additionally,we develop a reputation-based incentive mechanism to encourage users in IoV to actively participate in the federated learning and to practice honesty.The security analysis and performance evaluations are conducted to show that the proposed scheme can meet the security requirements and improve the performance of the FL model.展开更多
Rapeseed(Brassica napus L.)is one of the main oil crops in the world,and increasing its yield is of great significance for ensuring the safety of edible oil.Presently,improving rapeseed plant architecture is an effect...Rapeseed(Brassica napus L.)is one of the main oil crops in the world,and increasing its yield is of great significance for ensuring the safety of edible oil.Presently,improving rapeseed plant architecture is an effective way to increase rapeseed yield with higher planting density.However,the regulatory mechanism of rapeseed plant architecture is poorly understood.In this study,a dwarf rapeseed mutant dwarf08(df08)is obtained by ethyl methane sulfonate(EMS)-mutagenesis.The decrease in plant height of df08 is mainly caused by the reduction in main inflorescence length and first effective branch height and controlled by a single semi-dominant gene.The hybrid plants(F1)show a semi-dwarf phenotype.Through map-based cloning and transgenic assay,we confirm that the nonsynonymous single nucleotide variant(SNV)(C to T)in BnaC03.BIN2,which is homologous with Arabidopsis(Arabidopsis thaliana)BIN2,is responsible for the dwarfism of df08.BnaC03.BIN2 interacts with BnaBZR1/BES1 and involves in brassinosteroids(BRs)signal transduction.Proline to Leucine substitution in 284(P284L)enhances the protein stability of BnaC03.bin2-D,disrupts BRs signal transduction and affects the expression of genes regulating cell division,leading to dwarfism of df08.This study provides a new insight for the mechanism of rapeseed plant height regulation and creates an elite germplasm that can be used for genetic improvement of rapeseed architecture.展开更多
Quinoa is a good source of phenolics,which both exist as free and bound forms.In order to mark clear the characteristic free and bound phenolics in different quinoa samples,in this study,characteristic free and bound ...Quinoa is a good source of phenolics,which both exist as free and bound forms.In order to mark clear the characteristic free and bound phenolics in different quinoa samples,in this study,characteristic free and bound phenolics in three colored quinoas including WQ(white quinoa),RQ(red quinoa)and BQ(black quinoa)were investigated.Result showed a total of 14 phenolics both acted as free and bound form were analyzed in three colored quinoas(WQ,RQ and BQ).Gallic acid,vanillic acid,epicatechin,p-coumaric acid and quercetin existed both as free and bound forms were common phenolics in quinoas.The highest total free phenolics(238.10 mg/kg)and bound phenolics(3377.75 mg/kg)were presented in WQ and RQ,respectively.It indicated WQ and RQ were respectively good source of free and bound phenolics.Moreover,characteristic free and bound phenolics in three colored quinoas could be well analyzed by principal component analysis(PCA),indicating it was an effective and reliable method in distinguishing three colored quinoas based on their characteristic free and bound phenolics,respectively.展开更多
Corporate identity construction of external publicity image is an important part of the development of enterprises.Based on Wodak’s discourse-historical approach,this study takes the text of COFCO’s English promotio...Corporate identity construction of external publicity image is an important part of the development of enterprises.Based on Wodak’s discourse-historical approach,this study takes the text of COFCO’s English promotional video as the research object,analyzes the corporate brand image,media image,organizational image,and environmental image constructed by the enterprises from three steps:linguistic expression,discourse strategy,and theme to provide references for Chinese enterprises to enhance their international influence.展开更多
In industry, ethylene(C_(2)H_(4))/propylene(C_(3)H_(6)) separations are usually performed by a cryogenic process,which is energy intensive. Membrane separation technology is an alternative separation process that save...In industry, ethylene(C_(2)H_(4))/propylene(C_(3)H_(6)) separations are usually performed by a cryogenic process,which is energy intensive. Membrane separation technology is an alternative separation process that saves energy and is efficient. In this study, blend membranes were prepared by doping polyethylene glycol(PEG600) into a poly(ether-block-amide)(Pebax^(■) 2533) matrix and were used to separate the C_(2)H_(4)/C_(3)H_(6) mixture. The PEG 600 and Pebax^(■) 2533 polymers have good compatibility because they share hydrogen bonds. The addition of PEG600 is conducive to the hydrophilicity and the free volume of blend membranes, and it is also conducive to the solubility of C_(2)H_(4) and C_(3)H_(6) in the membranes, which improves the ability of the membranes to separate this gas pair. The Pebax^(■) 2533/PEG600 blend membrane with 15%(mass) PEG600 showed the highest separation performance in our investigated membranes, with a C_(3)H_(6)/C_(2)H_(4) selectivity of 8.9 and a C_(3)H_(6) permeability of 196 barrer(1 barrer = 1.33×10^(14)m^(3)(STP)·m·m^(-2)·s^(-1)·kPa^(-1)) at 238 K and 0.2 MPa, which is higher than that of the Pebax^(■) 2533/NaY-6%(mass) membrane(α_(C_(3)H_(6)/C_(2)H_(4)) =6.5, P_(C_(3)H_(6))=211 barrer) reported in our previous work. It is confirmed that incorporating PEG600 into the Pebax^(■) 2533 matrix to fabricate blend membranes is an efficient strategy for separating light olefins.展开更多
Due to the harsh actual operating environment of the permanent magnet wind turbine,it is easy to break down and difficult to monitor.Therefore,the electromagnetic characteristics identification of major fault types of...Due to the harsh actual operating environment of the permanent magnet wind turbine,it is easy to break down and difficult to monitor.Therefore,the electromagnetic characteristics identification of major fault types of large-scale permanent magnet wind turbines is studied in this paper.The typical faults of rotor eccentricity,stator winding short circuit and permanent magnet demagnetization of permanent magnet wind turbines are analyzed theoretically.The wavelet analysis algorithm is used to decompose and reconstruct the abnormal electromagnetic signal waveform band,and the characteristic frequency of the electromagnetic signal is obtained when the fault occurs.In order to verify the effectiveness of the proposed method,a 3.680MW permanent magnet wind turbine was taken as the research object.Its physical simulation model was established,and an external circuit was built to carry out field co-simulation.The results show that the motor fault type can be determined by detecting the change rule of fault characteristic frequency in the spectrum diagram,and the electromagnetic characteristic analysis can be applied to the early monitoring of the permanent magnet wind turbine fault.展开更多
Dimethyl oxalate(DMO) hydrogenation is a crucial step in the coal to ethylene glycol(CTEG) process.Herein, Cu catalyst supported on fibrous mesoporous silica(Cu/FMS) was synthesized via liquid phase deposition techniq...Dimethyl oxalate(DMO) hydrogenation is a crucial step in the coal to ethylene glycol(CTEG) process.Herein, Cu catalyst supported on fibrous mesoporous silica(Cu/FMS) was synthesized via liquid phase deposition technique and applied for the DMO hydrogenation to EG. The catalyst exhibited a remarkable EG selectivity of 96.95% and maintained its activity without deactivation for 1000 h. Fibers of FMS support and liquid phase deposition technology cooperated to give high dispersion of Cu species in the Cu/FMS catalyst, resulting in a high Cu surface area. The formation of Si—O—Cu during catalyst preparation process increased the Cu^(+)/(Cu^(0)+ Cu^(+)) ratio and enhanced the thermal and valence stability of Cu species.The high Cu^(+) surface area and Cu stability(thermal and valence stability) of the Cu/FMS catalyst were key factors for achieving superior EG selectivity and ultra-high stability.展开更多
Memtransistors combine memristors and field-effect transistors, which can introduce multi-port control and have significant applications for enriching storage methods. In this paper, multilayer α-In2Se3and MoS2were t...Memtransistors combine memristors and field-effect transistors, which can introduce multi-port control and have significant applications for enriching storage methods. In this paper, multilayer α-In2Se3and MoS2were transferred to the substrate by the mechanical exfoliation method, then a heterojunction MoS_(2)/α-In_(2)Se_(3) memtransistor was prepared. Neural synaptic simulations were performed using electrical and optical pulses as input signals. Through measurements, such as excitatory/inhibitory post-synaptic current(EPSC/IPSC), long-term potentiation/depression(LTP/LTD), and paired-pulse facilitation/depression(PPF/PPD), it can be found that the fabricated device could simulate various functions of neural synapses well, and could work as an electronic synapse in artificial neural networks, proposing a possible solution for neuromorphic storage and computation.展开更多
Microscopic vision has been widely applied in precision assembly.To achieve sufficiently high resolution in measurements for precision assembly when the sizes of the parts involved exceed the field of view of the visi...Microscopic vision has been widely applied in precision assembly.To achieve sufficiently high resolution in measurements for precision assembly when the sizes of the parts involved exceed the field of view of the vision system,an image mosaic technique must be used.In this paper,a method for constructing an image mosaic with non-overlapping areas with enhanced efficiency is proposed.First,an image mosaic model for the part is created using a geometric model of the measurement system installed on a X-Y-Z precision stages with high repeatability,and a path for image acquisition is established.Second,images are captured along the same path for a specified calibration plate,and an entire image is formed based on the given model.The measurement results obtained from the specified calibration plate are utilized to identify mosaic errors and apply compensation for the part requiring measurement.Experimental results show that the maximum error is less than 4μm for a camera with pixel equivalent 2.46μm,thereby demonstrating the accuracy of the proposed method.This image mosaic technique with non-overlapping regions can simplify image acquisition and reduce the workload involved in constructing an image mosaic.展开更多
An experimental study was conducted to investigate the properties of stratified regular or wavy two-phase flow in two parallel separators located after a manifold.A total of 103 experiments with various gas and liquid...An experimental study was conducted to investigate the properties of stratified regular or wavy two-phase flow in two parallel separators located after a manifold.A total of 103 experiments with various gas and liquid velocity combinations in three inlet pipes were conducted,including 77 groups of outlet pipe resistance symmetry and 26 groups of outlet pipe resistance asymmetry trials.The experimental results have revealed that when the gas-liquid flow rate is low,the degree of uneven splitting is high,and“extreme”conditions are attained.When the superficial gas velocity is greater than that established in the extreme case,the direction of the liquid-phase displacement is reversed,while that of the gas remains unchanged.Thus,the degree of gas phase bias tends to be mitigated with an increase in the gas velocity,while the uneven splitting degree of liquid approaches 10%.Finally,varying the gas-phase outlet pipe resistance is shown to effectively change the gas-liquid two-phase flow distribution.展开更多
Ultraintense short-period infrared laser pulses play an important role in frontier scientific research,but their power is quite low when generated using current technology.This paper demonstrates a scheme for generati...Ultraintense short-period infrared laser pulses play an important role in frontier scientific research,but their power is quite low when generated using current technology.This paper demonstrates a scheme for generating an ultraintense few-cycle infrared pulse by directly compressing a long infrared pulse.In this scheme,an infrared picosecond-to-nanosecond laser pulse counterpropagates with a rapidly extending plasma grating that is created by ionizing an undulated gas by a short laser pulse,and the infrared laser pulse is reflected by the rapidly extending plasma grating.Because of the high expansion velocity of the latter,the infrared laser pulse is compressed in the reflection process.One-and two-dimensional particle-in-cell simulations show that by this method,a pulse with a duration of tens of picoseconds in the mid-to far-infrared range can be compressed to a few cycles with an efficiency exceeding 60%,thereby making ultraintense few-cycle infrared pulses possible.展开更多
Damage detection is an important area with growing interest in mechanical and structural engineering.One of the critical issues in damage detection is how to determine indices sensitive to the structural damage and in...Damage detection is an important area with growing interest in mechanical and structural engineering.One of the critical issues in damage detection is how to determine indices sensitive to the structural damage and insensitive to the surrounding environmental variations.Current damage identification indices commonly focus on structural dynamic characteristics such as natural frequencies,mode shapes,and frequency responses.This study aimed at developing a technique based on energy Curvature Difference,power spectrum density,correlation-based index,load distribution factor,and neutral axis shift to assess the bridge deck condition.In addition to tracking energy and frequency over time using wavelet packet transform,in order to further demonstrate the feasibility and validity of the proposed technique for bridge condition assessment,experimental strain data measured from two stages of a bridge in the different intervals were used.The comparative analysis results of the bridge in first and second stage show changes in the proposed feature values.It is concluded,these changes in the values of the proposed features can be used to assess the bridge deck performance.展开更多
experience shared by human beings,but it is often expressed in the form of conceptual metaphor which is pervasive in the concrete language.Drawing upon the theory of conceptual metaphor and emotion metaphors,this pape...experience shared by human beings,but it is often expressed in the form of conceptual metaphor which is pervasive in the concrete language.Drawing upon the theory of conceptual metaphor and emotion metaphors,this paper aims to study the translation of positive emotions in David Hawkes’version of The Story of the Stone and the related daily expressions as the corpus.According to the theories,this paper categorizes the positive emotions metaphors into body metaphors,sensory metaphors,entity metaphors,and orientational metaphors to discuss the process of English translation and the metaphorical mechanism,analyzes the similarities and differences between Chinese and English expressions of positive emotions and their cultural,physiological,and psychological motives,and lastly attempts to summarize the translation strategies of emotional expressions.The analysis of metaphorical mechanisms reveals that the common physiological and psychological experiences of human beings and cultural exchanges give rise to similarities,while the unique cultural environments,antecedents,and historical development of each nation give rise to their distinctiveness.This paper concludes that translators need to make full use of their subjectivity,understand the surface and underlying meaning of the text,and establish a high level of mental compatibility between themselves,the readers,and the author.展开更多
基金supported by the National Natural Science Foundation of China(82070593)the Zhejiang Provincial Natural Science Foundation(LD21H030002)+1 种基金the Department of Science and Technology of Zhejiang Province(ZY2019008)the Youth Program of the National Natural Science Foundation of China(82200632).
文摘One-third of patients with autoimmune hepatitis(AIH)have cirrhosis at the time of diagnosis.The relevance of these variables,although unknown,is believed to be critical in AIH because of suspected interactions between the gut microbiome and genetic factors.Dysbiosis of the gut flora and elevated polymeric immunoglobulin receptor(pIgR)levels have been observed in both patients and mouse models.Moreover,there is a direct relationship between pIgR expression and transaminase levels in patients with AIH.In this study,we aimed to explore how pIgR influences the secretion of regenerating islet-derived 3 beta(Reg3b)and the flora composition in AIH using in vivo experiments involving patients with AIH and a concanavalin A-induced mouse model of AIH.Reg3b expression was reduced in pIgR gene(Pigr)-knockout mice compared to that in wild-type mice,leading to increased microbiota disruption.Conversely,exogenous pIgR supplementation increased Reg3b expression and maintained microbiota homeostasis.RNA sequencing revealed the participation of the interleukin(IL)-17 signaling pathway in the regulation of Reg3b through pIgR.Furthermore,the introduction of external pIgR could not restore the imbalance in gut microbiota in AIH,and the decrease in Reg3b expression was not apparent following the inhibition of signal transducer and activator of transcription 3(STAT3).In this study,pIgR facilitated the upregulation of Reg3b via the STAT3 pathway,which plays a crucial role in preserving the balance of the intestinal microbiota in AIH.Through this research,we discovered new molecular targets that can be used for the diagnosis and treatment of AIH.
基金supported by the National Natural Science Foundation of China under Grant 61972148.
文摘The application of artificial intelligence technology in Internet of Vehicles(lov)has attracted great research interests with the goal of enabling smart transportation and traffic management.Meanwhile,concerns have been raised over the security and privacy of the tons of traffic and vehicle data.In this regard,Federated Learning(FL)with privacy protection features is considered a highly promising solution.However,in the FL process,the server side may take advantage of its dominant role in model aggregation to steal sensitive information of users,while the client side may also upload malicious data to compromise the training of the global model.Most existing privacy-preserving FL schemes in IoV fail to deal with threats from both of these two sides at the same time.In this paper,we propose a Blockchain based Privacy-preserving Federated Learning scheme named BPFL,which uses blockchain as the underlying distributed framework of FL.We improve the Multi-Krum technology and combine it with the homomorphic encryption to achieve ciphertext-level model aggregation and model filtering,which can enable the verifiability of the local models while achieving privacy-preservation.Additionally,we develop a reputation-based incentive mechanism to encourage users in IoV to actively participate in the federated learning and to practice honesty.The security analysis and performance evaluations are conducted to show that the proposed scheme can meet the security requirements and improve the performance of the FL model.
基金supported by the National Key Research and Development Program of China(2022YFD1200401)the National Natural Science Foundation of China(U22A20477,32172095)the Central Public-interest Scientific Institution Basal Research Fund(Y2022QC21).
文摘Rapeseed(Brassica napus L.)is one of the main oil crops in the world,and increasing its yield is of great significance for ensuring the safety of edible oil.Presently,improving rapeseed plant architecture is an effective way to increase rapeseed yield with higher planting density.However,the regulatory mechanism of rapeseed plant architecture is poorly understood.In this study,a dwarf rapeseed mutant dwarf08(df08)is obtained by ethyl methane sulfonate(EMS)-mutagenesis.The decrease in plant height of df08 is mainly caused by the reduction in main inflorescence length and first effective branch height and controlled by a single semi-dominant gene.The hybrid plants(F1)show a semi-dwarf phenotype.Through map-based cloning and transgenic assay,we confirm that the nonsynonymous single nucleotide variant(SNV)(C to T)in BnaC03.BIN2,which is homologous with Arabidopsis(Arabidopsis thaliana)BIN2,is responsible for the dwarfism of df08.BnaC03.BIN2 interacts with BnaBZR1/BES1 and involves in brassinosteroids(BRs)signal transduction.Proline to Leucine substitution in 284(P284L)enhances the protein stability of BnaC03.bin2-D,disrupts BRs signal transduction and affects the expression of genes regulating cell division,leading to dwarfism of df08.This study provides a new insight for the mechanism of rapeseed plant height regulation and creates an elite germplasm that can be used for genetic improvement of rapeseed architecture.
基金support of Youth Project of Liaoning Provincial Education Department(JYTQN2023334)Anhui Provincial Department of Education Key Research Project on Natural Science in Higher Education Institutions(KJ2021A1072)Science and Technology Plan Project of Chuzhou Science and Technology Bureau(2021ZD023).
文摘Quinoa is a good source of phenolics,which both exist as free and bound forms.In order to mark clear the characteristic free and bound phenolics in different quinoa samples,in this study,characteristic free and bound phenolics in three colored quinoas including WQ(white quinoa),RQ(red quinoa)and BQ(black quinoa)were investigated.Result showed a total of 14 phenolics both acted as free and bound form were analyzed in three colored quinoas(WQ,RQ and BQ).Gallic acid,vanillic acid,epicatechin,p-coumaric acid and quercetin existed both as free and bound forms were common phenolics in quinoas.The highest total free phenolics(238.10 mg/kg)and bound phenolics(3377.75 mg/kg)were presented in WQ and RQ,respectively.It indicated WQ and RQ were respectively good source of free and bound phenolics.Moreover,characteristic free and bound phenolics in three colored quinoas could be well analyzed by principal component analysis(PCA),indicating it was an effective and reliable method in distinguishing three colored quinoas based on their characteristic free and bound phenolics,respectively.
文摘Corporate identity construction of external publicity image is an important part of the development of enterprises.Based on Wodak’s discourse-historical approach,this study takes the text of COFCO’s English promotional video as the research object,analyzes the corporate brand image,media image,organizational image,and environmental image constructed by the enterprises from three steps:linguistic expression,discourse strategy,and theme to provide references for Chinese enterprises to enhance their international influence.
基金the financial support of the National Key Research and Development Program of China (2020YFB0606405)the Basic Research Program of Shanxi Province (20210302123197)+2 种基金the Key Project of the National Natural Science Foundation of China (21336006)the Scientific Research Foundation for Returned Scholars of Ministry of Education (2017047)the Foundation of State Key Laboratory of Highefficiency Utilization of Coal and Green Chemical Engineering (2017-K15)。
文摘In industry, ethylene(C_(2)H_(4))/propylene(C_(3)H_(6)) separations are usually performed by a cryogenic process,which is energy intensive. Membrane separation technology is an alternative separation process that saves energy and is efficient. In this study, blend membranes were prepared by doping polyethylene glycol(PEG600) into a poly(ether-block-amide)(Pebax^(■) 2533) matrix and were used to separate the C_(2)H_(4)/C_(3)H_(6) mixture. The PEG 600 and Pebax^(■) 2533 polymers have good compatibility because they share hydrogen bonds. The addition of PEG600 is conducive to the hydrophilicity and the free volume of blend membranes, and it is also conducive to the solubility of C_(2)H_(4) and C_(3)H_(6) in the membranes, which improves the ability of the membranes to separate this gas pair. The Pebax^(■) 2533/PEG600 blend membrane with 15%(mass) PEG600 showed the highest separation performance in our investigated membranes, with a C_(3)H_(6)/C_(2)H_(4) selectivity of 8.9 and a C_(3)H_(6) permeability of 196 barrer(1 barrer = 1.33×10^(14)m^(3)(STP)·m·m^(-2)·s^(-1)·kPa^(-1)) at 238 K and 0.2 MPa, which is higher than that of the Pebax^(■) 2533/NaY-6%(mass) membrane(α_(C_(3)H_(6)/C_(2)H_(4)) =6.5, P_(C_(3)H_(6))=211 barrer) reported in our previous work. It is confirmed that incorporating PEG600 into the Pebax^(■) 2533 matrix to fabricate blend membranes is an efficient strategy for separating light olefins.
基金supported by the National Natural Science Foundation of China(U22A20215 and 51537007)the Natural Science Foundation of LiaoNing Province(2021-YQ-09).
文摘Due to the harsh actual operating environment of the permanent magnet wind turbine,it is easy to break down and difficult to monitor.Therefore,the electromagnetic characteristics identification of major fault types of large-scale permanent magnet wind turbines is studied in this paper.The typical faults of rotor eccentricity,stator winding short circuit and permanent magnet demagnetization of permanent magnet wind turbines are analyzed theoretically.The wavelet analysis algorithm is used to decompose and reconstruct the abnormal electromagnetic signal waveform band,and the characteristic frequency of the electromagnetic signal is obtained when the fault occurs.In order to verify the effectiveness of the proposed method,a 3.680MW permanent magnet wind turbine was taken as the research object.Its physical simulation model was established,and an external circuit was built to carry out field co-simulation.The results show that the motor fault type can be determined by detecting the change rule of fault characteristic frequency in the spectrum diagram,and the electromagnetic characteristic analysis can be applied to the early monitoring of the permanent magnet wind turbine fault.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51863005,51462006,51102230,51671062,51871065,and 51971068)the Guangxi Natural Science Foundation(No.2018GXNSFDA281051,2014GXNSFAA118401,and 2020GXNSFGA297004)+2 种基金the Science Research and Technology Development Program of Guangxi(AD17195073,AA19182014 and AA17202030-1)the Guangxi Bagui Scholar Foundation,the Guangxi Collabora-tive Innovation Centre of Structure and Property for New Energy and Materials,the Guangxi Advanced Functional Materials Foundation and Application Talents Small Highlands,Chinesisch-Deutsche Kooperationsgruppe(GZ1528)the Innovation Project of GUET Graduate Education(2019YCXS114 and 2018YJCX88).
文摘We deviseda functional form stable compositephase-change materials(PCMs)toachieve a three-dimensional(3D)interconnectedporous carbon aerogel structure for encapsulating polyethyleneglycol(PEG).Anovelhomogeneity reinforced carbonaerogel witha well-interconnected porous structure was constructed bycombining a flexible carbonresource from biomass guar gum with hard-brittle carbonfrom polyimide,to overcome severeshrinkage andpoor mechanical performance of traditionalcarbon aerogel.Thesupportingcarbon aerogel-encapsulated PEG produced thenovel composite PCMswithgood structure stability andcomprehensive energy storage performance.Theresults showed thatthecomposite PCMsdisplayed awell-defined 3Dinterconnected structure,and theirenergy storage capacities were 171.5 and169.5 J/g,which changed onlyslightlyafter 100 thermalcycles,andthe compositescould maintainthe equilibrium temperature at50.0−58.1℃ for about 760.3 s.The thermal conductivityofthe compositescould reach0.62 W m^(−1) K^(−1),which effectively enhanced the thermalresponse rate.And thecomposite PCMs exhibited good leakage-proof performance andexcellent light–thermal conversion.The compressive strengthof thecomposite PCMscan improveupto 1.602 MPa.Results indicatethatthisstrategy canbe efficiently usedtodevelop novel composite PCMswithimproved comprehensive thermalperformance and high light–thermal conversion.
基金financial support from the National Natural Science Foundation of China(22078238,21961132005,and 21908160)the National Key Research and Development Program of China(2022YFC2104800 and 2021YFC2100800).
基金financially supported by National Natural Science Foundation of China (22008166)Natural Science Foundation of Shanxi (201901D211047)Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (2019L0185)。
文摘Dimethyl oxalate(DMO) hydrogenation is a crucial step in the coal to ethylene glycol(CTEG) process.Herein, Cu catalyst supported on fibrous mesoporous silica(Cu/FMS) was synthesized via liquid phase deposition technique and applied for the DMO hydrogenation to EG. The catalyst exhibited a remarkable EG selectivity of 96.95% and maintained its activity without deactivation for 1000 h. Fibers of FMS support and liquid phase deposition technology cooperated to give high dispersion of Cu species in the Cu/FMS catalyst, resulting in a high Cu surface area. The formation of Si—O—Cu during catalyst preparation process increased the Cu^(+)/(Cu^(0)+ Cu^(+)) ratio and enhanced the thermal and valence stability of Cu species.The high Cu^(+) surface area and Cu stability(thermal and valence stability) of the Cu/FMS catalyst were key factors for achieving superior EG selectivity and ultra-high stability.
基金Project supported by the National Natural Science Foundation of China (Grant No. 51702245)。
文摘Memtransistors combine memristors and field-effect transistors, which can introduce multi-port control and have significant applications for enriching storage methods. In this paper, multilayer α-In2Se3and MoS2were transferred to the substrate by the mechanical exfoliation method, then a heterojunction MoS_(2)/α-In_(2)Se_(3) memtransistor was prepared. Neural synaptic simulations were performed using electrical and optical pulses as input signals. Through measurements, such as excitatory/inhibitory post-synaptic current(EPSC/IPSC), long-term potentiation/depression(LTP/LTD), and paired-pulse facilitation/depression(PPF/PPD), it can be found that the fabricated device could simulate various functions of neural synapses well, and could work as an electronic synapse in artificial neural networks, proposing a possible solution for neuromorphic storage and computation.
基金supported by the Liaoning Revitalization Talents Program(Grant No.XLYC2002020)the Major Project of Basic Scientific Research of Chinese Ministry(Grant No.JCYK2016205A003).
文摘Microscopic vision has been widely applied in precision assembly.To achieve sufficiently high resolution in measurements for precision assembly when the sizes of the parts involved exceed the field of view of the vision system,an image mosaic technique must be used.In this paper,a method for constructing an image mosaic with non-overlapping areas with enhanced efficiency is proposed.First,an image mosaic model for the part is created using a geometric model of the measurement system installed on a X-Y-Z precision stages with high repeatability,and a path for image acquisition is established.Second,images are captured along the same path for a specified calibration plate,and an entire image is formed based on the given model.The measurement results obtained from the specified calibration plate are utilized to identify mosaic errors and apply compensation for the part requiring measurement.Experimental results show that the maximum error is less than 4μm for a camera with pixel equivalent 2.46μm,thereby demonstrating the accuracy of the proposed method.This image mosaic technique with non-overlapping regions can simplify image acquisition and reduce the workload involved in constructing an image mosaic.
基金supported by the National Science and Technology Major Project of China(No.2016ZX05028-004-003).
文摘An experimental study was conducted to investigate the properties of stratified regular or wavy two-phase flow in two parallel separators located after a manifold.A total of 103 experiments with various gas and liquid velocity combinations in three inlet pipes were conducted,including 77 groups of outlet pipe resistance symmetry and 26 groups of outlet pipe resistance asymmetry trials.The experimental results have revealed that when the gas-liquid flow rate is low,the degree of uneven splitting is high,and“extreme”conditions are attained.When the superficial gas velocity is greater than that established in the extreme case,the direction of the liquid-phase displacement is reversed,while that of the gas remains unchanged.Thus,the degree of gas phase bias tends to be mitigated with an increase in the gas velocity,while the uneven splitting degree of liquid approaches 10%.Finally,varying the gas-phase outlet pipe resistance is shown to effectively change the gas-liquid two-phase flow distribution.
基金China Academy of Engineering Physics(Grant No.CX20200022)the National Key Program for S&T Research and Development(Grant No.2018YFA0404804)the National Natural Science Foundation of China(Grant No.11875240).
文摘Ultraintense short-period infrared laser pulses play an important role in frontier scientific research,but their power is quite low when generated using current technology.This paper demonstrates a scheme for generating an ultraintense few-cycle infrared pulse by directly compressing a long infrared pulse.In this scheme,an infrared picosecond-to-nanosecond laser pulse counterpropagates with a rapidly extending plasma grating that is created by ionizing an undulated gas by a short laser pulse,and the infrared laser pulse is reflected by the rapidly extending plasma grating.Because of the high expansion velocity of the latter,the infrared laser pulse is compressed in the reflection process.One-and two-dimensional particle-in-cell simulations show that by this method,a pulse with a duration of tens of picoseconds in the mid-to far-infrared range can be compressed to a few cycles with an efficiency exceeding 60%,thereby making ultraintense few-cycle infrared pulses possible.
文摘Damage detection is an important area with growing interest in mechanical and structural engineering.One of the critical issues in damage detection is how to determine indices sensitive to the structural damage and insensitive to the surrounding environmental variations.Current damage identification indices commonly focus on structural dynamic characteristics such as natural frequencies,mode shapes,and frequency responses.This study aimed at developing a technique based on energy Curvature Difference,power spectrum density,correlation-based index,load distribution factor,and neutral axis shift to assess the bridge deck condition.In addition to tracking energy and frequency over time using wavelet packet transform,in order to further demonstrate the feasibility and validity of the proposed technique for bridge condition assessment,experimental strain data measured from two stages of a bridge in the different intervals were used.The comparative analysis results of the bridge in first and second stage show changes in the proposed feature values.It is concluded,these changes in the values of the proposed features can be used to assess the bridge deck performance.
基金“Comparative Study of the Cultivation of Chinese-English Translation Ability in China Mainland,Hong Kong SAR,and China Taiwan”of Hunan Provincial Philosophy and Social Science Foundation(Project number:18JD71)“Research on Xi Jinping’s Overseas Signed Articles Based on Comparable Corpus”of Hunan Provincial Philosophy and Social Science Foundation(Project number:21YBA016)“A Practical Exploration of Translation Theory Talents in Universities Based on Enterprise Training”of Industry-Academy Cooperative Educational Project of Ministry of Education in 2023。
文摘experience shared by human beings,but it is often expressed in the form of conceptual metaphor which is pervasive in the concrete language.Drawing upon the theory of conceptual metaphor and emotion metaphors,this paper aims to study the translation of positive emotions in David Hawkes’version of The Story of the Stone and the related daily expressions as the corpus.According to the theories,this paper categorizes the positive emotions metaphors into body metaphors,sensory metaphors,entity metaphors,and orientational metaphors to discuss the process of English translation and the metaphorical mechanism,analyzes the similarities and differences between Chinese and English expressions of positive emotions and their cultural,physiological,and psychological motives,and lastly attempts to summarize the translation strategies of emotional expressions.The analysis of metaphorical mechanisms reveals that the common physiological and psychological experiences of human beings and cultural exchanges give rise to similarities,while the unique cultural environments,antecedents,and historical development of each nation give rise to their distinctiveness.This paper concludes that translators need to make full use of their subjectivity,understand the surface and underlying meaning of the text,and establish a high level of mental compatibility between themselves,the readers,and the author.