With the popularisation of intelligent power,power devices have different shapes,numbers and specifications.This means that the power data has distributional variability,the model learning process cannot achieve suffi...With the popularisation of intelligent power,power devices have different shapes,numbers and specifications.This means that the power data has distributional variability,the model learning process cannot achieve sufficient extraction of data features,which seriously affects the accuracy and performance of anomaly detection.Therefore,this paper proposes a deep learning-based anomaly detection model for power data,which integrates a data alignment enhancement technique based on random sampling and an adaptive feature fusion method leveraging dimension reduction.Aiming at the distribution variability of power data,this paper developed a sliding window-based data adjustment method for this model,which solves the problem of high-dimensional feature noise and low-dimensional missing data.To address the problem of insufficient feature fusion,an adaptive feature fusion method based on feature dimension reduction and dictionary learning is proposed to improve the anomaly data detection accuracy of the model.In order to verify the effectiveness of the proposed method,we conducted effectiveness comparisons through elimination experiments.The experimental results show that compared with the traditional anomaly detection methods,the method proposed in this paper not only has an advantage in model accuracy,but also reduces the amount of parameter calculation of the model in the process of feature matching and improves the detection speed.展开更多
This paper studies the countermeasure design problems of distributed resilient time-varying formation-tracking control for multi-UAV systems with single-way communications against composite attacks,including denial-of...This paper studies the countermeasure design problems of distributed resilient time-varying formation-tracking control for multi-UAV systems with single-way communications against composite attacks,including denial-of-services(DoS)attacks,false-data injection attacks,camouflage attacks,and actuation attacks(AAs).Inspired by the concept of digital twin,a new two-layered protocol equipped with a safe and private twin layer(TL)is proposed,which decouples the above problems into the defense scheme against DoS attacks on the TL and the defense scheme against AAs on the cyber-physical layer.First,a topologyrepairing strategy against frequency-constrained DoS attacks is implemented via a Zeno-free event-triggered estimation scheme,which saves communication resources considerably.The upper bound of the reaction time needed to launch the repaired topology after the occurrence of DoS attacks is calculated.Second,a decentralized adaptive and chattering-relief controller against potentially unbounded AAs is designed.Moreover,this novel adaptive controller can achieve uniformly ultimately bounded convergence,whose error bound can be given explicitly.The practicability and validity of this new two-layered protocol are shown via a simulation example and a UAV swarm experiment equipped with both Ultra-WideBand and WiFi communication channels.展开更多
Background Frontal lobe injury(FLI)is related to cognitive control impairments,but the influences of FLI on the internal subprocesses of cognitive control remain unclear.Aims We sought to identify specific biomarkers ...Background Frontal lobe injury(FLI)is related to cognitive control impairments,but the influences of FLI on the internal subprocesses of cognitive control remain unclear.Aims We sought to identify specific biomarkers for long-term dysfunction or compensatory modulation in different cognitive control subprocesses.Methods A retrospective case-control study was conducted.Event-related potentials(ERP),oscillations and functional connectivity were used to analyse electroencephalography(EEG)data from 12 patients with unilateral frontal lobe injury(UFLI),12 patients with bilateral frontal lobe injury(BFLI)and 26 healthy controls(HCs)during a Go/NoGo task,which included several subprocesses:perceptual processing,anticipatory preparation,conflict monitoring and response decision.Results Compared with the HC group,N2(the second negative peak in the averaged ERP waveform)latency,and frontal and parietal oscillations were decreased only in the BFLI group,whereas P3(the third positive peak in the averaged ERP waveform)amplitudes and sensorimotor oscillations were decreased in both patient groups.The functional connectivity of the four subprocesses was as follows:alpha connections of posterior networks in the BFLI group were lower than in the HC and UFLI groups,and these alpha connections were negatively correlated with neuropsychological tests.Theta connections of the dorsal frontoparietal network in the bilateral hemispheres of the BFLI group were lower than in the HC and UFLI groups,and these connections in the uninjured hemisphere of the UFLI group were higher than in the HC group,which were negatively correlated with behavioural performances.Delta and theta connections of the midfrontal-related networks in the BFLI group were lower than in the HC group.Theta across-network connections in the HC group were higher than in the BFLI group but lower than in the UFLI group.Conclusions The enhancement of low-frequency connections reflects compensatory mechanisms.In contrast,alpha connections are the opposite,therefore revealing more abnormal neural activity and less compensatory connectivity as the severity of injury increases.The nodes of the above networks may serve as stimulating targets for early treatment to restore corresponding functions.EEG biomarkers can measure neuromodulation effects in heterogeneous patients.展开更多
The harmonics and resonance of traction power supply systems(TPSSs)aggravate the electromagnetic interference(EMI)to adjacent metallic pipelines(MPs),which has aroused widespread concern.In this paper,an evaluation me...The harmonics and resonance of traction power supply systems(TPSSs)aggravate the electromagnetic interference(EMI)to adjacent metallic pipelines(MPs),which has aroused widespread concern.In this paper,an evaluation method on pipeline interference voltage under harmonic induction is presented.The results show that the Carson integral formula is more accurate in calculating the mutual impedance at higher frequencies.Then,an integrated train-network-pipeline model is established to estimate the influences of harmonic distortion and resonance on an MP.It is revealed that the higher the harmonic cur-rent distortion rate of the traction load,the larger the interference voltage on an MP.Particularly,the interference voltage is amplified up to 7 times when the TPSS resonates,which is worthy of attention.In addition,the parameters that affect the variation and sensitivity of the interference voltage are studied,namely,the pipeline coating material,locomotive position,and soil resistivity,indicating that soil resistivity and 3PE(3-layer polyethylene)anticorrosive coating are more sensitive to harmonic induction.Field test results show that the harmonic distortion can make the interference voltage more serious,and the protective measures are optimized.展开更多
Objective:To investigate the efteets of traditional Chinese medicine.Danzhi decoction,on the expression angiogenesis factors in human endometrial cells during the sequelae of pelvic inflammatoty disease(SPID) and expl...Objective:To investigate the efteets of traditional Chinese medicine.Danzhi decoction,on the expression angiogenesis factors in human endometrial cells during the sequelae of pelvic inflammatoty disease(SPID) and explore the role of Danzhi decction in improving the blood stasis microenvironment of SPID.Methods:A three-dimensional(3D) co—culture system including human vascular endothelial cells(VECs),endometrial stromal cells and glandular epithelial cells was established in vitro and treated with Danzhi decoction,sterilized water and aspirin respectively.A Milliplex multifunctional liquid chip technique was used to measure the expression levels of vascular endothelial growth factor(VEGF)—A/C/D,fibroblast growth factor-1/2.angiopoietin-2.epidermal growth factor(EGF) HB-EGF,bone morphogenetic protein-9.endoglin.endothehn-l.granulocyte colony stimulating factor,hepatocyte growth factor,interleukin-8,follistatin.placenta growth factor and leptin.The location of angiogenesis factors was monitored by immunofluorescence labeling and confocal laser scanning microscope3 D reconstruction.Results:Endometrial stromal cells and glandular epithelial cells were isolated and primary cultured for establishing a 3D co-culture system.The levels of VEGF—A/C/D in Danzhi decoction group and aspirin group were significantly lower than those in mock group(P<0.05).while there was no significant difference between Danzhi decoction group and aspirin group(P>0.05).Furthermore,the alterative location of VEGF—A/C/D was observed in the cytoplasm of endometrial glandular epithelial cells.Conclusions:Danzhi decoction mav inhibit the expression of VEGF in the blood stasis microenvironment of SPID by targeting the cytoplasm of endometrial glandular epithelial cell.展开更多
Phase engineering is an important strategy to modulate the electronic structure of molybdenum disulfide(MoS_(2)).MoS_(2)-based composites are usually used for the electromagnetic wave(EMW)absorber,but the effect of di...Phase engineering is an important strategy to modulate the electronic structure of molybdenum disulfide(MoS_(2)).MoS_(2)-based composites are usually used for the electromagnetic wave(EMW)absorber,but the effect of different phases on the EMW absorbing performance,such as 1T and 2H phase,is still not studied.In this work,micro-1T/2H MoS_(2) is achieved via a facile one-step hydrother-mal route,in which the 1T phase is induced by the intercalation of guest molecules and ions.The EMW absorption mechanism of single MoS_(2) is revealed by presenting a comparative study between 1T/2H MoS_(2) and 2H MoS_(2).As a result,1T/2H MoS_(2) with the matrix loading of 15%exhibits excellent microwave absorption property than 2H MoS_(2).Furthermore,taking the advantage of 1T/2H MoS_(2),a flexible EMW absorbers that ultrathin 1T/2H MoS_(2)grown on the carbon fiber also performs outstanding performance only with the matrix loading of 5%.This work offers necessary reference to improve microwave absorption performance by phase engineering and design a new type of flexible electromagnetic wave absorption material to apply for the portable microwave absorption electronic devices.展开更多
The gasifier temperature is a key parameter in the operation of a slag-tapping entrained-flow gasifier.However,there is no effective method for measuring the operating temperature of a membrane-wall-lined gasifier.In ...The gasifier temperature is a key parameter in the operation of a slag-tapping entrained-flow gasifier.However,there is no effective method for measuring the operating temperature of a membrane-wall-lined gasifier.In this study,a novel robust method for estimation of the online temperature was developed for a membrane-wall gasifier and applied in an industrial SE gasifier.The industrial test results show that the method can estimate the gasifier temperature within 0.04 s,and its value can be reliably obtained.Based on the combination of bench-scale gasifier validation,commercial-scale gasifier operation experience,and the comparison of different simulation methods,the proposed method is accurate and reliable for measuring the operating temperature of a membrane-wall-lined gasifier.展开更多
Poly(methyl methacrylate)(PMMA) is widely used for graphene transfer and device fabrication.However,it inevitably leaves a thin layer of polymer residues after acetone rinsing and leads to dramatic degradation of devi...Poly(methyl methacrylate)(PMMA) is widely used for graphene transfer and device fabrication.However,it inevitably leaves a thin layer of polymer residues after acetone rinsing and leads to dramatic degradation of device performance.How to eliminate contamination and restore clean surfaces of graphene is still highly demanded.In this paper,we present a reliable and position-controllable method to remove the polymer residues on graphene films by laser exposure.Under proper laser conditions,PMMA residues can be substantially reduced without introducing defects to the underlying graphene.Furthermore,by applying this laser cleaning technique to the channel and contacts of graphene fieldeffect transistors(GFETs),higher carrier mobility as well as lower contact resistance can be realized.This work opens a way for probing intrinsic properties of contaminant-free graphene and fabricating high-performance GFETs with both clean channel and intimate graphene/metal contact.展开更多
Programmed cell death(PCD)and secondary cell wall(SCW)thickening in pear fruit are accompanied by the deposition of cellulose and lignin to form stone cells.Metacaspase is an important protease for development,tissue ...Programmed cell death(PCD)and secondary cell wall(SCW)thickening in pear fruit are accompanied by the deposition of cellulose and lignin to form stone cells.Metacaspase is an important protease for development,tissue renewal and PCD.The understanding of the molecular mechanism whereby pear(Pyrus)metacaspase promotes PCD and cell wall lignification is still limited.In this study,the Metacaspases gene family(PbMCs)from P.bretschneideri was identified.PbMC1a/1b was associated with lignin deposition and stone cell formation by physiological data,semiquantitative real-time polymerase chain reaction(RT-PCR)and quantitative RT-PCR(qRT-PCR).Relative to wildtype(WT)Arabidopsis,the overexpression of PbMC1a/1b increased lignin deposition and delayed growth,thickened the cell walls of vessels,xylary fibers and interfascicular fibers,and increased the expression of lignin biosynthetic genes.Yeast two-hybrid(Y2H),bimolecular fluorescence complementation(BiFC)and GST pull-down assays indicated that the PbMC1a/1b protein physically interacted with PbRD21.Simultaneously,the transient expression of PbMC1a/1b and PbRD21 led to significant changes in the expression of genes and lignin contents in pear fruits and flesh calli.These results indicate that PbMC1a/1b plays an important role in cell wall lignification,possibly by interacting with PbRD21 to increase the mRNA levels of some lignin synthesis-associated genes and promote the formation of stone cells in pear fruit.展开更多
In 2020 and 2021,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,caused a global pandemic.Vaccines are expected to reduce the pressure of prevention and control,and have become the most...In 2020 and 2021,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,caused a global pandemic.Vaccines are expected to reduce the pressure of prevention and control,and have become the most effective strategy to solve the pandemic crisis.SARS-CoV-2 infects the host by binding to the cellular receptor angiotensin converting enzyme 2(ACE2)via the receptor-binding domain(RBD)of the surface spike(S)glycoprotein.In this study,a candidate vaccine based on a RBD recombinant subunit was prepared by means of a novel glycoengineered yeast Pichia pastoris expression system with characteristics of glycosylation modification similar to those of mammalian cells.The candidate vaccine effectively stimulated mice to produce high-titer anti-RBD specific antibody.Furthermore,the specific antibody titer and virus-neutralizing antibody(NAb)titer induced by the vaccine were increased significantly by the combination of the double adjuvants Al(OH)_(3) and CpG.Our results showed that the virus-NAb lasted for more than six months in mice.To summarize,we have obtained a SARS-CoV-2 vaccine based on the RBD of the S glycoprotein expressed in glycoengineered Pichia pastoris,which stimulates neutralizing and protective antibody responses.A technical route for fucose-free complex-type N-glycosylation modified recombinant subunit vaccine preparation has been established.展开更多
As the widely implemented electrode material,graphite has the characteristic of sublimation by the thermal shock of the switching arc,and the produced carbon vapor is easy to condense into carbon powders and deposit i...As the widely implemented electrode material,graphite has the characteristic of sublimation by the thermal shock of the switching arc,and the produced carbon vapor is easy to condense into carbon powders and deposit in the switch.The impact of the type of dilution gas in a mixture of20%oxygen and 80%dilution gas on the sublimation and oxidation characteristics of the graphite electrode is investigated.It is found that when nitrogen dilution gas was replaced by argon,the heat flux to the electrodes decreased,which led to a 63%reduction of graphite sublimation.At the same time,the cooling rate of the arc was slower in argon,which promotes oxidation of the carbon vapor.The residual solid carbon can be reduced by 70%–85%by using argon as the dilution gas.Consequently,it is demonstrated that the stability and working life of the switch could be increased by appropriate selection of the dilution gas.展开更多
Spike architecture influences both grain weight and grain number per spike,which are the two major components of grain yield in bread wheat(Triticum aestivum L.).However,the complex wheat genome and the influence of var...Spike architecture influences both grain weight and grain number per spike,which are the two major components of grain yield in bread wheat(Triticum aestivum L.).However,the complex wheat genome and the influence of various environmental factors pose challenges in mapping the causal genes that affect spike traits.Here,we systematically identified genes involved in spike trait formation by integrating information on genomic variation and gene regulatory networks controlling young spike development in wheat.We identified 170 loci that are responsible for variations in spike length,spikelet number per spike,and grain number per spike through genome-wide association study and meta-QTL analyses.We constructed gene regulatory networks for young inflorescences at the double ridge stage and thefloret primordium stage,in which the spikelet meristem and thefloret meristem are predominant,respec-tively,by integrating transcriptome,histone modification,chromatin accessibility,eQTL,and protein–pro-tein interactome data.From these networks,we identified 169 hub genes located in 76 of the 170 QTL regions whose polymorphisms are significantly associated with variation in spike traits.The functions of TaZF-B1,VRT-B2,and TaSPL15-A/D in establishment of wheat spike architecture were verified.This study provides valuable molecular resources for understanding spike traits and demonstrates that combining genetic analysis and developmental regulatory networks is a robust approach for dissection of complex traits.展开更多
Based on the commercial computational software, a three-dimensional finite ele- ment model to simulate the thermo-mechanical behaviors in a nuclear fuel rod is established; By taking into consideration irradiation-swe...Based on the commercial computational software, a three-dimensional finite ele- ment model to simulate the thermo-mechanical behaviors in a nuclear fuel rod is established; By taking into consideration irradiation-swelling of the pellet and the irradiation damage effects in the cladding together with the coupling effects between the temperature field and the mechanical field, the user subroutines to define the special material performance and boundary conditions have been developed independently and validated. Three-dimensional numerical simulation of the thermo-mechanical coupling behaviors in a nuclear fuel rod is carried out, and the evolution rules of the important thermal and mechanical variables are obtained and analyzed. The research re- sults indicate that: (i) the fuel pellets will be in contact with the cladding at high burnup, which will induce a strong mechanical interaction between them; (2) the irradiation creep effect plays an important role in the mechanical behavior evolution in the nuclear fuel rod.展开更多
The bulk flow properties of four different fly ashes were assessed at ambient temperature and at 500 ~C, using a high temperature annular shear cell. These powders all resulted from industrial processes and had simila...The bulk flow properties of four different fly ashes were assessed at ambient temperature and at 500 ~C, using a high temperature annular shear cell. These powders all resulted from industrial processes and had similar chemical compositions but different particle size distributions. Applying a high temperature was found to increase the powder cohesion, with this effect being more significant in the case of the sample with the highest proportion of fines. To better understand the effect of temperature on the bulk flow properties of these materials, a model previously proposed by some of the authors was used to correlate the powder isostatic tensile strength with the interparticle forces and microscale particle contact struc- ture. This model combines the continuum approach with description of particle-to-particle interactions. A comparison with experimental data indicated that the effects of consolidation and temperature on the tensile strength of the fly ashes were correctly described by the model. This theoretical approach also elucidates the mechanism by which the temperature affects the bulk flow properties of fly ashes through modifications of the microscale intemarticle contacts.展开更多
This paper presents our study on removal of carbon dioxide(CO_(2)) greenhouse gas emissions by using the mixture of ammonia and soil.CO_(2) capture capacity using this method is 15%higher than the sum of ammonia chemi...This paper presents our study on removal of carbon dioxide(CO_(2)) greenhouse gas emissions by using the mixture of ammonia and soil.CO_(2) capture capacity using this method is 15%higher than the sum of ammonia chemical absorption capacity and soil physical adsorption capacity.Scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)are utilized to study this synergism.The removal effect is not only reflected in ammonia chemical reaction with CO_(2).CO_(2) can also be absorbed by ammonium bicarbonate(NH_(4)HCO_(3)) crystal,which is the main component of the product,or wrapped in the pore of the crystal or packed in the gap between the crystal and the soil.CO_(2) can be permanently deposited as carbonated minerals in the subsoil earth layers.展开更多
This work studied the mechanical properties of a series of industrial fuel powders: bituminite, lignite, and petroleum coke. Sieved cuts of these powders were assessed and the flow properties of each sample were used...This work studied the mechanical properties of a series of industrial fuel powders: bituminite, lignite, and petroleum coke. Sieved cuts of these powders were assessed and the flow properties of each sample were used to calculate tensile strengths as functions of consolidation stress. In addition, BET surface areas and dispersive surface energies were estimated from surface energy analysis. To analyze the bulk flow properties of these fuel powders in terms of micro-contact mechanics, the fundamentals of fuel powder adhesion and consolidation were reconsidered based on the "stiff particles with soft contacts" model proposed by Tomas. In the present work, a multi-contact concept was introduced to account for the irregular shapes of actual particles. This modified model was based on elastic-plastic contact deformation theory and was employed to describe the contact between rough particles and to estimate the associated inter-particle forces. The results were used in conjunction with the Rumpf approach to relate the isostatic tensile strength to the degree of consolidation, Applying average values for the powder compressibility parameters allowed the model to be used for predictive purposes, and an acceptable level of agreement was found between predicted and measured tensile strengths.展开更多
文摘With the popularisation of intelligent power,power devices have different shapes,numbers and specifications.This means that the power data has distributional variability,the model learning process cannot achieve sufficient extraction of data features,which seriously affects the accuracy and performance of anomaly detection.Therefore,this paper proposes a deep learning-based anomaly detection model for power data,which integrates a data alignment enhancement technique based on random sampling and an adaptive feature fusion method leveraging dimension reduction.Aiming at the distribution variability of power data,this paper developed a sliding window-based data adjustment method for this model,which solves the problem of high-dimensional feature noise and low-dimensional missing data.To address the problem of insufficient feature fusion,an adaptive feature fusion method based on feature dimension reduction and dictionary learning is proposed to improve the anomaly data detection accuracy of the model.In order to verify the effectiveness of the proposed method,we conducted effectiveness comparisons through elimination experiments.The experimental results show that compared with the traditional anomaly detection methods,the method proposed in this paper not only has an advantage in model accuracy,but also reduces the amount of parameter calculation of the model in the process of feature matching and improves the detection speed.
基金This work was supported in part by the National Natural Science Foundation of China(61903258)Guangdong Basic and Applied Basic Research Foundation(2022A1515010234)+1 种基金the Project of Department of Education of Guangdong Province(2022KTSCX105)Qatar National Research Fund(NPRP12C-0814-190012).
文摘This paper studies the countermeasure design problems of distributed resilient time-varying formation-tracking control for multi-UAV systems with single-way communications against composite attacks,including denial-of-services(DoS)attacks,false-data injection attacks,camouflage attacks,and actuation attacks(AAs).Inspired by the concept of digital twin,a new two-layered protocol equipped with a safe and private twin layer(TL)is proposed,which decouples the above problems into the defense scheme against DoS attacks on the TL and the defense scheme against AAs on the cyber-physical layer.First,a topologyrepairing strategy against frequency-constrained DoS attacks is implemented via a Zeno-free event-triggered estimation scheme,which saves communication resources considerably.The upper bound of the reaction time needed to launch the repaired topology after the occurrence of DoS attacks is calculated.Second,a decentralized adaptive and chattering-relief controller against potentially unbounded AAs is designed.Moreover,this novel adaptive controller can achieve uniformly ultimately bounded convergence,whose error bound can be given explicitly.The practicability and validity of this new two-layered protocol are shown via a simulation example and a UAV swarm experiment equipped with both Ultra-WideBand and WiFi communication channels.
基金This work was supported by the National Natural Science Foundation of China(82271933,81971800 and 81871536)Priority Academic Program Development of Jiangsu Higher Education Institutes(PAPD)(SYSD2012063)Shandong Provincial Natural Science Foundation(ZR2023QH434),China.
文摘Background Frontal lobe injury(FLI)is related to cognitive control impairments,but the influences of FLI on the internal subprocesses of cognitive control remain unclear.Aims We sought to identify specific biomarkers for long-term dysfunction or compensatory modulation in different cognitive control subprocesses.Methods A retrospective case-control study was conducted.Event-related potentials(ERP),oscillations and functional connectivity were used to analyse electroencephalography(EEG)data from 12 patients with unilateral frontal lobe injury(UFLI),12 patients with bilateral frontal lobe injury(BFLI)and 26 healthy controls(HCs)during a Go/NoGo task,which included several subprocesses:perceptual processing,anticipatory preparation,conflict monitoring and response decision.Results Compared with the HC group,N2(the second negative peak in the averaged ERP waveform)latency,and frontal and parietal oscillations were decreased only in the BFLI group,whereas P3(the third positive peak in the averaged ERP waveform)amplitudes and sensorimotor oscillations were decreased in both patient groups.The functional connectivity of the four subprocesses was as follows:alpha connections of posterior networks in the BFLI group were lower than in the HC and UFLI groups,and these alpha connections were negatively correlated with neuropsychological tests.Theta connections of the dorsal frontoparietal network in the bilateral hemispheres of the BFLI group were lower than in the HC and UFLI groups,and these connections in the uninjured hemisphere of the UFLI group were higher than in the HC group,which were negatively correlated with behavioural performances.Delta and theta connections of the midfrontal-related networks in the BFLI group were lower than in the HC group.Theta across-network connections in the HC group were higher than in the BFLI group but lower than in the UFLI group.Conclusions The enhancement of low-frequency connections reflects compensatory mechanisms.In contrast,alpha connections are the opposite,therefore revealing more abnormal neural activity and less compensatory connectivity as the severity of injury increases.The nodes of the above networks may serve as stimulating targets for early treatment to restore corresponding functions.EEG biomarkers can measure neuromodulation effects in heterogeneous patients.
基金This work was supported by the National Natural Science Foundation of China(No.51877182).
文摘The harmonics and resonance of traction power supply systems(TPSSs)aggravate the electromagnetic interference(EMI)to adjacent metallic pipelines(MPs),which has aroused widespread concern.In this paper,an evaluation method on pipeline interference voltage under harmonic induction is presented.The results show that the Carson integral formula is more accurate in calculating the mutual impedance at higher frequencies.Then,an integrated train-network-pipeline model is established to estimate the influences of harmonic distortion and resonance on an MP.It is revealed that the higher the harmonic cur-rent distortion rate of the traction load,the larger the interference voltage on an MP.Particularly,the interference voltage is amplified up to 7 times when the TPSS resonates,which is worthy of attention.In addition,the parameters that affect the variation and sensitivity of the interference voltage are studied,namely,the pipeline coating material,locomotive position,and soil resistivity,indicating that soil resistivity and 3PE(3-layer polyethylene)anticorrosive coating are more sensitive to harmonic induction.Field test results show that the harmonic distortion can make the interference voltage more serious,and the protective measures are optimized.
基金supported by a grant from the National Natural Science Founlation of China(81373677)
文摘Objective:To investigate the efteets of traditional Chinese medicine.Danzhi decoction,on the expression angiogenesis factors in human endometrial cells during the sequelae of pelvic inflammatoty disease(SPID) and explore the role of Danzhi decction in improving the blood stasis microenvironment of SPID.Methods:A three-dimensional(3D) co—culture system including human vascular endothelial cells(VECs),endometrial stromal cells and glandular epithelial cells was established in vitro and treated with Danzhi decoction,sterilized water and aspirin respectively.A Milliplex multifunctional liquid chip technique was used to measure the expression levels of vascular endothelial growth factor(VEGF)—A/C/D,fibroblast growth factor-1/2.angiopoietin-2.epidermal growth factor(EGF) HB-EGF,bone morphogenetic protein-9.endoglin.endothehn-l.granulocyte colony stimulating factor,hepatocyte growth factor,interleukin-8,follistatin.placenta growth factor and leptin.The location of angiogenesis factors was monitored by immunofluorescence labeling and confocal laser scanning microscope3 D reconstruction.Results:Endometrial stromal cells and glandular epithelial cells were isolated and primary cultured for establishing a 3D co-culture system.The levels of VEGF—A/C/D in Danzhi decoction group and aspirin group were significantly lower than those in mock group(P<0.05).while there was no significant difference between Danzhi decoction group and aspirin group(P>0.05).Furthermore,the alterative location of VEGF—A/C/D was observed in the cytoplasm of endometrial glandular epithelial cells.Conclusions:Danzhi decoction mav inhibit the expression of VEGF in the blood stasis microenvironment of SPID by targeting the cytoplasm of endometrial glandular epithelial cell.
基金the National Natural Science Foundation of China(No.51672222)Joint Fund Project-Enterprise-Shaanxi Coal Joint Fund Project(2019JLM-32)+2 种基金Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(CX202054)the Graduate innovation team of Northwestern Polytechnical Universitythe Analysis and Testing Center of Northwestern Polytechnical University for their technical assistance in SEM(Verios G4).
文摘Phase engineering is an important strategy to modulate the electronic structure of molybdenum disulfide(MoS_(2)).MoS_(2)-based composites are usually used for the electromagnetic wave(EMW)absorber,but the effect of different phases on the EMW absorbing performance,such as 1T and 2H phase,is still not studied.In this work,micro-1T/2H MoS_(2) is achieved via a facile one-step hydrother-mal route,in which the 1T phase is induced by the intercalation of guest molecules and ions.The EMW absorption mechanism of single MoS_(2) is revealed by presenting a comparative study between 1T/2H MoS_(2) and 2H MoS_(2).As a result,1T/2H MoS_(2) with the matrix loading of 15%exhibits excellent microwave absorption property than 2H MoS_(2).Furthermore,taking the advantage of 1T/2H MoS_(2),a flexible EMW absorbers that ultrathin 1T/2H MoS_(2)grown on the carbon fiber also performs outstanding performance only with the matrix loading of 5%.This work offers necessary reference to improve microwave absorption performance by phase engineering and design a new type of flexible electromagnetic wave absorption material to apply for the portable microwave absorption electronic devices.
基金supported by the National Natural Science Foundation of China(21878082,21376082,U1402272 and 21776087)National Key Research Program of China(2017YFB0602604)the Fundamental Research Funds for the Central Universities.
文摘The gasifier temperature is a key parameter in the operation of a slag-tapping entrained-flow gasifier.However,there is no effective method for measuring the operating temperature of a membrane-wall-lined gasifier.In this study,a novel robust method for estimation of the online temperature was developed for a membrane-wall gasifier and applied in an industrial SE gasifier.The industrial test results show that the method can estimate the gasifier temperature within 0.04 s,and its value can be reliably obtained.Based on the combination of bench-scale gasifier validation,commercial-scale gasifier operation experience,and the comparison of different simulation methods,the proposed method is accurate and reliable for measuring the operating temperature of a membrane-wall-lined gasifier.
基金the National Basic Research Program of China(Grant No.2013CBA01604)the National Science and Technology Major Project of China(Grant No.2011ZX02707)
文摘Poly(methyl methacrylate)(PMMA) is widely used for graphene transfer and device fabrication.However,it inevitably leaves a thin layer of polymer residues after acetone rinsing and leads to dramatic degradation of device performance.How to eliminate contamination and restore clean surfaces of graphene is still highly demanded.In this paper,we present a reliable and position-controllable method to remove the polymer residues on graphene films by laser exposure.Under proper laser conditions,PMMA residues can be substantially reduced without introducing defects to the underlying graphene.Furthermore,by applying this laser cleaning technique to the channel and contacts of graphene fieldeffect transistors(GFETs),higher carrier mobility as well as lower contact resistance can be realized.This work opens a way for probing intrinsic properties of contaminant-free graphene and fabricating high-performance GFETs with both clean channel and intimate graphene/metal contact.
基金supported by the Major Science and Technology Project of Corps(2017DB006)the National Natural Science Foundation of China(31972361,31672105,and 31372044)the National High-Technology Research,Development Program(2011AA10020602),for the design of the study and the collection,analyses,and interpretation of data.
文摘Programmed cell death(PCD)and secondary cell wall(SCW)thickening in pear fruit are accompanied by the deposition of cellulose and lignin to form stone cells.Metacaspase is an important protease for development,tissue renewal and PCD.The understanding of the molecular mechanism whereby pear(Pyrus)metacaspase promotes PCD and cell wall lignification is still limited.In this study,the Metacaspases gene family(PbMCs)from P.bretschneideri was identified.PbMC1a/1b was associated with lignin deposition and stone cell formation by physiological data,semiquantitative real-time polymerase chain reaction(RT-PCR)and quantitative RT-PCR(qRT-PCR).Relative to wildtype(WT)Arabidopsis,the overexpression of PbMC1a/1b increased lignin deposition and delayed growth,thickened the cell walls of vessels,xylary fibers and interfascicular fibers,and increased the expression of lignin biosynthetic genes.Yeast two-hybrid(Y2H),bimolecular fluorescence complementation(BiFC)and GST pull-down assays indicated that the PbMC1a/1b protein physically interacted with PbRD21.Simultaneously,the transient expression of PbMC1a/1b and PbRD21 led to significant changes in the expression of genes and lignin contents in pear fruits and flesh calli.These results indicate that PbMC1a/1b plays an important role in cell wall lignification,possibly by interacting with PbRD21 to increase the mRNA levels of some lignin synthesis-associated genes and promote the formation of stone cells in pear fruit.
基金supported by the National Key Research and Development Program of China (2020YFC0841400-008)the National Science and Technology Major Projects(2018ZX09711003-013-002)the National Natural Science Foundation of China (81673339 and 81773619)
文摘In 2020 and 2021,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,caused a global pandemic.Vaccines are expected to reduce the pressure of prevention and control,and have become the most effective strategy to solve the pandemic crisis.SARS-CoV-2 infects the host by binding to the cellular receptor angiotensin converting enzyme 2(ACE2)via the receptor-binding domain(RBD)of the surface spike(S)glycoprotein.In this study,a candidate vaccine based on a RBD recombinant subunit was prepared by means of a novel glycoengineered yeast Pichia pastoris expression system with characteristics of glycosylation modification similar to those of mammalian cells.The candidate vaccine effectively stimulated mice to produce high-titer anti-RBD specific antibody.Furthermore,the specific antibody titer and virus-neutralizing antibody(NAb)titer induced by the vaccine were increased significantly by the combination of the double adjuvants Al(OH)_(3) and CpG.Our results showed that the virus-NAb lasted for more than six months in mice.To summarize,we have obtained a SARS-CoV-2 vaccine based on the RBD of the S glycoprotein expressed in glycoengineered Pichia pastoris,which stimulates neutralizing and protective antibody responses.A technical route for fucose-free complex-type N-glycosylation modified recombinant subunit vaccine preparation has been established.
基金supported by National Natural Science Foundation of China(Nos.51777082 and 52077091)Chinese Scholarship Council(No.201906160101)。
文摘As the widely implemented electrode material,graphite has the characteristic of sublimation by the thermal shock of the switching arc,and the produced carbon vapor is easy to condense into carbon powders and deposit in the switch.The impact of the type of dilution gas in a mixture of20%oxygen and 80%dilution gas on the sublimation and oxidation characteristics of the graphite electrode is investigated.It is found that when nitrogen dilution gas was replaced by argon,the heat flux to the electrodes decreased,which led to a 63%reduction of graphite sublimation.At the same time,the cooling rate of the arc was slower in argon,which promotes oxidation of the carbon vapor.The residual solid carbon can be reduced by 70%–85%by using argon as the dilution gas.Consequently,it is demonstrated that the stability and working life of the switch could be increased by appropriate selection of the dilution gas.
基金supported by STI2030-Major Projects (2023ZD0406802)the Fundamental Research Funds for the Central Universities (2662020ZKPY002)+1 种基金the National Key Laboratory of Crop Genetic Improvement Self-Research Program (ZW19A0201)the HZAUAGIS Cooperation Fund 869 (SZYJY2021006).
文摘Spike architecture influences both grain weight and grain number per spike,which are the two major components of grain yield in bread wheat(Triticum aestivum L.).However,the complex wheat genome and the influence of various environmental factors pose challenges in mapping the causal genes that affect spike traits.Here,we systematically identified genes involved in spike trait formation by integrating information on genomic variation and gene regulatory networks controlling young spike development in wheat.We identified 170 loci that are responsible for variations in spike length,spikelet number per spike,and grain number per spike through genome-wide association study and meta-QTL analyses.We constructed gene regulatory networks for young inflorescences at the double ridge stage and thefloret primordium stage,in which the spikelet meristem and thefloret meristem are predominant,respec-tively,by integrating transcriptome,histone modification,chromatin accessibility,eQTL,and protein–pro-tein interactome data.From these networks,we identified 169 hub genes located in 76 of the 170 QTL regions whose polymorphisms are significantly associated with variation in spike traits.The functions of TaZF-B1,VRT-B2,and TaSPL15-A/D in establishment of wheat spike architecture were verified.This study provides valuable molecular resources for understanding spike traits and demonstrates that combining genetic analysis and developmental regulatory networks is a robust approach for dissection of complex traits.
基金Project supported by the National Natural Science Foundation of China(Nos.11172068,91226101,11072062 and91026005)the Research Fund for the Doctoral Program of Higher Education of China(No.20110071110013)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA01020304)
文摘Based on the commercial computational software, a three-dimensional finite ele- ment model to simulate the thermo-mechanical behaviors in a nuclear fuel rod is established; By taking into consideration irradiation-swelling of the pellet and the irradiation damage effects in the cladding together with the coupling effects between the temperature field and the mechanical field, the user subroutines to define the special material performance and boundary conditions have been developed independently and validated. Three-dimensional numerical simulation of the thermo-mechanical coupling behaviors in a nuclear fuel rod is carried out, and the evolution rules of the important thermal and mechanical variables are obtained and analyzed. The research re- sults indicate that: (i) the fuel pellets will be in contact with the cladding at high burnup, which will induce a strong mechanical interaction between them; (2) the irradiation creep effect plays an important role in the mechanical behavior evolution in the nuclear fuel rod.
文摘The bulk flow properties of four different fly ashes were assessed at ambient temperature and at 500 ~C, using a high temperature annular shear cell. These powders all resulted from industrial processes and had similar chemical compositions but different particle size distributions. Applying a high temperature was found to increase the powder cohesion, with this effect being more significant in the case of the sample with the highest proportion of fines. To better understand the effect of temperature on the bulk flow properties of these materials, a model previously proposed by some of the authors was used to correlate the powder isostatic tensile strength with the interparticle forces and microscale particle contact struc- ture. This model combines the continuum approach with description of particle-to-particle interactions. A comparison with experimental data indicated that the effects of consolidation and temperature on the tensile strength of the fly ashes were correctly described by the model. This theoretical approach also elucidates the mechanism by which the temperature affects the bulk flow properties of fly ashes through modifications of the microscale intemarticle contacts.
基金the support by the National Development Programming of Key Fundamental Researches of China(2004CB217700)Program for Changjiang Scholars and Innovative Research Team of Ministry of Education(PCSIRT-IRT0620)Subsidy Scheme of Outstanding Academic Leaders in Shanghai(08XD1401300).
文摘This paper presents our study on removal of carbon dioxide(CO_(2)) greenhouse gas emissions by using the mixture of ammonia and soil.CO_(2) capture capacity using this method is 15%higher than the sum of ammonia chemical absorption capacity and soil physical adsorption capacity.Scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)are utilized to study this synergism.The removal effect is not only reflected in ammonia chemical reaction with CO_(2).CO_(2) can also be absorbed by ammonium bicarbonate(NH_(4)HCO_(3)) crystal,which is the main component of the product,or wrapped in the pore of the crystal or packed in the gap between the crystal and the soil.CO_(2) can be permanently deposited as carbonated minerals in the subsoil earth layers.
文摘This work studied the mechanical properties of a series of industrial fuel powders: bituminite, lignite, and petroleum coke. Sieved cuts of these powders were assessed and the flow properties of each sample were used to calculate tensile strengths as functions of consolidation stress. In addition, BET surface areas and dispersive surface energies were estimated from surface energy analysis. To analyze the bulk flow properties of these fuel powders in terms of micro-contact mechanics, the fundamentals of fuel powder adhesion and consolidation were reconsidered based on the "stiff particles with soft contacts" model proposed by Tomas. In the present work, a multi-contact concept was introduced to account for the irregular shapes of actual particles. This modified model was based on elastic-plastic contact deformation theory and was employed to describe the contact between rough particles and to estimate the associated inter-particle forces. The results were used in conjunction with the Rumpf approach to relate the isostatic tensile strength to the degree of consolidation, Applying average values for the powder compressibility parameters allowed the model to be used for predictive purposes, and an acceptable level of agreement was found between predicted and measured tensile strengths.