Privacy protection is the key to maintaining the Internet of Things(IoT)communication strategy.Steganography is an important way to achieve covert communication that protects user data privacy.Steganalysis technology ...Privacy protection is the key to maintaining the Internet of Things(IoT)communication strategy.Steganography is an important way to achieve covert communication that protects user data privacy.Steganalysis technology is the key to checking steganography security,and its ultimate goal is to extract embedded messages.Existing methods cannot extract under known cover images.To this end,this paper proposes a method of extracting embedded messages under known cover images.First,the syndrome-trellis encoding process is analyzed.Second,a decoding path in the syndrome trellis is obtained by using the stego sequence and a certain parity-check matrix,while the embedding process is simulated using the cover sequence and parity-check matrix.Since the decoding path obtained by the stego sequence and the correct parity-check matrix is optimal and has the least distortion,comparing the path consistency can quickly filter the coding parameters to determine the correct matrices,and embedded messages can be extracted correctly.The proposed method does not need to embed all possible messages for the second time,improving coding parameter recognition significantly.The experimental results show that the proposed method can identify syndrome-trellis coding parameters in stego images embedded by adaptive steganography quickly to realize embedded message extraction.展开更多
Objective:To explore the effect and mechanism of action of the Wenjing Zhitong recipe(WZR)in primary dysmenorrhea(PD)treatment.Methods:Uterine contractions were induced by estradiol benzoate and oxytocin in a PD model...Objective:To explore the effect and mechanism of action of the Wenjing Zhitong recipe(WZR)in primary dysmenorrhea(PD)treatment.Methods:Uterine contractions were induced by estradiol benzoate and oxytocin in a PD model and WZR was administrated.The rate of change in uterine contractility and the writhing test were used to evaluate the effects of WZR.The serum levels of prostaglandin F_(2a)(PGF_(2a))and prostaglandin E_2(PGE_2),and the activity of cyclooxygenase-2(COX2)were detected by enzyme-linked immunosorbent assay(ELISA).The changes in phosphor-phospholipase C(pPLC/PLC),phosphor-protein kinase C(pPKC/PKC),and connexin 43(CX43)expression were detected using immunohistochemistry and western blot.Results:WZR significantly reduced the rate of change in uterine contractility and writhing times in the PD model.WZR treatment inhibited the enzymatic activity of COX2 and reduced the levels of PGF_(2a),PGF_(2a)/PGE2and COX2 in the PD model.WZR also significantly reduced the expression of pPLC/PLC,pPKC/PKC and CX43.Targeting the inhibition of COX2 activity,caffeic acid and 1-acetyl-β-carboline were validated as the active ingredients in WZR responsible for reducing uterine contractions.Conclusion:WZR attenuated PD by inhibiting COX2 activity,downregulating PGF_(2a)/PGE_2 expression,and inhibiting the PKC signaling pathway.展开更多
The financial market is the core of national economic development,and stocks play an important role in the financial market.Analyzing stock prices has become the focus of investors,analysts,and people in related field...The financial market is the core of national economic development,and stocks play an important role in the financial market.Analyzing stock prices has become the focus of investors,analysts,and people in related fields.This paper evaluates the volatility of Apple Inc.(AAPL)returns using five generalized autoregressive conditional heteroskedasticity(GARCH)models:sGARCH with constant mean,GARCH with sstd,GJR-GARCH,AR(1)GJR-GARCH,and GJR-GARCH in mean.The distribution of AAPL’s closing price and earnings data was analyzed,and skewed student t-distribution(sstd)and normal distribution(norm)were used to further compare the data distribution of the five models and capture the shape,skewness,and loglikelihood in Model 4-AR(1)GJR-GARCH.Through further analysis,the results showed that Model 4,AR(1)GJR-GARCH,is the optimal model to describe the volatility of the return series of AAPL.The analysis of the research process is both,a process of exploration and reflection.By analyzing the stock price of AAPL,we reflect on the shortcomings of previous analysis methods,clarify the purpose of the experiment,and identify the optimal analysis model.展开更多
Self-rooted apple stock is widely used for apple production.However,the shallowness of the adventitious roots in self-rooted apple stock leads to poor performance in the barren orchards of China.This is because of the...Self-rooted apple stock is widely used for apple production.However,the shallowness of the adventitious roots in self-rooted apple stock leads to poor performance in the barren orchards of China.This is because of the considerable difference in the development of a gravitropic set-point angle(GSA)between self-rooted apple stock and seedling rootstock.Therefore,it is crucial to study the molecular mechanism of adventitious root GSA in self-rooted apple stock for breeding self-rooted and deep-rooted apple rootstock cultivars.An apple auxin response factor MdARF19 functioned to establish the adventitious root GSA of self-rooted apple stock in response to gravity and auxin signals.MdARF19 bound directly to the MdPIN7 promoter,activating its transcriptional expression and thus regulating the formation of the adventitious root GSA in 12-2 self-rooted apple stock.However,MdARF19 influenced the expression of auxin efflux carriers(MdPIN3 and MdPIN10)and the establishment of adventitious root GSA of self-rooted apple stock in response to gravity signals by direct activation of MdFLP.Our findings provide new information on the transcriptional regulation of MdPIN7 by auxin response factor MdARF19 in the regulation of the adventitious root GSA of self-rooted apple stock in response to gravity and auxin signals.展开更多
Carrying out green energy transformation,implementing clean energy power replacement and supply,and developing a new power system are some primary driving forces needed to fulfill China’s carbon-peak and carbon-neutr...Carrying out green energy transformation,implementing clean energy power replacement and supply,and developing a new power system are some primary driving forces needed to fulfill China’s carbon-peak and carbon-neutral strategic goals.The construction of new power systems in China’s provinces and cities is developing rapidly,and the lack of a typical model promotes the application.The new power system path design should be based on the actual development of the power grid in different regions,energy use characteristics,and other actual needs to carry out the differentiated path design.In this context,this study analyzes the characteristics of the new domestic power system based on the policy background of the new domestic power system,constructs a new model for power system development stage identification,and proposes the overall design of the new power system development path from the power supply,transmission and distribution,and load sides.It also uses the Hebei South Network as an example to explore the development stage of the Hebei South Grid based on actual development needs.Finally,this study designs a novel power system development path for the entire supply and demand chain for the Hebei South Grid to propose ideas for constructing a new power system in China and to help green energy transformation.展开更多
Flavonols and proanthocyanidins(PAs)are the main pigments in the black spines of cucumber(Cucumis sativus)fruit,and CsMYB60 is a key regulator of the biosynthesis of flavonols and PAs.However,in cucumber,the tissue di...Flavonols and proanthocyanidins(PAs)are the main pigments in the black spines of cucumber(Cucumis sativus)fruit,and CsMYB60 is a key regulator of the biosynthesis of flavonols and PAs.However,in cucumber,the tissue distribution pattern of flavonols and PAs and the mechanism of their biosynthesis regulated by CsMYB60 remain unclear.In this study,we clarified the tissue-specific distribution of flavonoids and the unique transcriptional regulation of flavonoid biosynthesis in cucumber.CsMYB60 activated CsFLS and CsLAR by binding to their promoters and directly or indirectly promoted the expression of CsbHLH42,CsMYC1,CsWD40,and CsTATA-box binding protein,resulting in the formation of complexes of these four proteins to increase the expression of Cs4CL and interact with CsTATA-box binding protein to regulate the expression of CsCHS,thereby regulating the biosynthesis of flavonols and PAs in cucumber.Our data provide new insights into the molecular mechanism of flavonoid biosynthesis,which will facilitate molecular breeding to improve fruit quality in cucumber.展开更多
Synechococcus is one of the most abundant picocyanobacteria in marine ecosystem,and the absence of Prochlorococcus would make it indispensable as a primary producer in the Bohai Sea,North China.However,the abundance d...Synechococcus is one of the most abundant picocyanobacteria in marine ecosystem,and the absence of Prochlorococcus would make it indispensable as a primary producer in the Bohai Sea,North China.However,the abundance distribution and genetic diversity of Synechococcus in this region have rarely been reported.In this study,the distribution pattern of Synechococcus abundance was investigated during four cruises in April,June,August,and November from 2018 to 2019,moreover,its phenogenetic diversity was studied based on high-throughput sequencing of the cpe BA operon.The results demonstrate that phycoerythrin-containing Synechococcus was most abundant in August when temperature was high and oxygen saturation was low.During this period,Synechococcus pigment type(PT)2 was abundant in the Bohai Bay and Laizhou Bay under conditions of high nutrient concentration,temperature,and turbidity.In comparison,PT3,especially those clusters characterized with high or variable ratio of phycourobilin and phycoerythrobilin,was predominant in the Bohai Strait and Liaodong Bay under conditions of high salinity,pH,and oxygen saturation.Furthermore,co-occurrence correlations using network analysis revealed that Synechococcus PTs were related to 15.37%-43.48%of the prokaryotic genera.Synechococcus PT3c/PT3d and PT2 were the most important PTs in the network.The hierarchical clustering revealed that taxa co-occurred with Synechococcus PTs diff ered among samples.It could be attributed to the substance exchange and the environmental impact,which calls for more studies in the future.展开更多
The comparison of domestic and foreign studies has been utilized to extensively employ junction termination extension(JTE)structures for power devices.However,achieving a gradual doping concentration change in the lat...The comparison of domestic and foreign studies has been utilized to extensively employ junction termination extension(JTE)structures for power devices.However,achieving a gradual doping concentration change in the lateral direction is difficult for SiC devices since the diffusion constants of the implanted aluminum ions in SiC are much less than silicon.Many previously reported studies adopted many new structures to solve this problem.Additionally,the JTE structure is strongly sensitive to the ion implantation dose.Thus,GA-JTE,double-zone etched JTE structures,and SM-JTE with modulation spacing were reported to overcome the above shortcomings of the JTE structure and effectively increase the breakdown voltage.They provided a theoretical basis for fabricating terminal structures of 4H-SiC PiN diodes.This paper summarized the effects of different terminal structures on the electrical properties of SiC devices at home and abroad.Presently,the continuous development and breakthrough of terminal technology have significantly improved the breakdown voltage and terminal efficiency of 4H-SiC PiN power diodes.展开更多
As the core economic variable in the process of the integration of world economy,the change of the exchange rate has an important impact on the import and export,foreign exchange reserves,interest rates,capital flows ...As the core economic variable in the process of the integration of world economy,the change of the exchange rate has an important impact on the import and export,foreign exchange reserves,interest rates,capital flows and other macro and microeconomic factors.This paper first analyzes the status quo of RMB exchange rate risk and the advanced experience of exchange rate management of other countries.Then,the empirical method is used to analyze the characteristics of RMB exchange rate fluctuation based on the day-frequency data of USD/RMB,GBP/RMB,EUR/RMB and JPY/RMB from December 2011 to December 2016.This paper also respectively uses the GARCH,TARCH,EGARCH and PARCH model to fit four representative foreign currencies against RMB,and selects the optimal model to calculate VaR value.Finally,validity of the data is verified through the Chi-square distribution test.The empirical results show that the four sequences are non-normal and first-order monotonic sequences.Besides,there is a significantly high-order ARCH effect,and the GARCH family model has a better fitting effect.JPY/RMB is with lower exchange rate risk,while the fluctuation of EUR/RMB is significantly greater than other currencies.According to the international situation of financial market,the status quo of RMB exchange rate and the conclusion of empirical research,this paper puts forward that the marketization and internationalization of RMB exchange rate should be based on improving the financial system and environment.It is also suggested that the government should properly intervene in the foreign exchange market and make good use of the risk measurement model and commercial banks should further develop the financial derivatives to hedge the foreign exchange risk.展开更多
Cardiovascular health metrics are now widely recognized as modifable risk factors for cognitive decline and dementia.Metabolic perturbations might play roles in the linkage of cardiovascular diseases and dementia.Circ...Cardiovascular health metrics are now widely recognized as modifable risk factors for cognitive decline and dementia.Metabolic perturbations might play roles in the linkage of cardiovascular diseases and dementia.Circulating metabolites profling by metabolomics may improve understanding of the potential mechanism by which cardiovascular risk factors contribute to cognitive decline.In a prospective community-based cohort in China(n=725),312 serum metabolic phenotypes were quantifed,and cardiovascular health score was calculated including smoking,exercise,sleep,diet,body mass index,blood pressure,and blood glucose.Cognitive function assessments were conducted in baseline and follow-up visits to identify longitudinal cognitive decline.A better cardiovascular health was signifcantly associated with lower risk of concentration decline and orientation decline(hazard ratio(HR):0.84–0.90;p<0.05).Apolipoprotein-A1,high-density lipoprotein(HDL)cholesterol,cholesterol ester,and phospholipid concentrations were signifcantly associated with a lower risk of longitudinal memory and orientation decline(p<0.05 and adjusted-p<0.20).Mediation analysis suggested that the negative association between health status and the risk of orientation decline was partly mediated by cholesterol ester and total lipids in HDL-2 and-3(proportion of mediation:7.68–8.21%,both p<0.05).Cardiovascular risk factors were associated with greater risks of cognitive decline,which were found to be mediated by circulating lipoproteins,particularly the medium-size HDL components.These fndings underscore the potential of utilizing lipoproteins as targets for early stage dementia screening and intervention.展开更多
Microbial application is an efficient, economical, and ecofriendly method for remediating black-odorous rivers. In this study, the field treatment effect and microbial community changes were monitored during remediati...Microbial application is an efficient, economical, and ecofriendly method for remediating black-odorous rivers. In this study, the field treatment effect and microbial community changes were monitored during remediation by the acclimated complex microorganisms of a typical black-odorous stream. After the treatment, the total phosphorus and ammonia contents decreased by 74.0% and 76.3% and the concentrations of dissolved oxygen increased from 1.65 to 4.90 mg/L, indicating the effectiveness of the acclimated composite microorganisms. The proportion of Bacteroidetes decreased significantly by 48.1% and that of Firmicutes increased by 2.23% on average, and the microbial diversity index first increased and then tended to be uniform. Redundancy analysis demonstrated that the pH,dissolved oxygen, and oxidation-reduction potential together determined the composition of the microbial communities(p < 0.05). These findings showed that the acclimated composite microorganisms can effectively remediate the black odor.展开更多
Currently, modeling studies tend to significantly underestimate observed space-based glyoxal (CHOCHO) vertical column densities (VCDs), implying the existence of missing sources of giyoxal. Several recent studies ...Currently, modeling studies tend to significantly underestimate observed space-based glyoxal (CHOCHO) vertical column densities (VCDs), implying the existence of missing sources of giyoxal. Several recent studies suggest that the emissions of aromatic compounds and molar yields of glyoxal in the chemical mechanisms may both be underestimated, which can affect the simulated glyoxal concentrations. In this study, the influences of these two factors on glyoxal amounts over China were investigated using the RAMS-CMAQ modeling system for January and July 2014. Four sensitivity simulations were performed, and the results were compared to satellite observations. These results demonstrated significant impacts on glyoxal concentrations from these two factors. In case 1, where the emissions of aromatic compounds were increased three-fold, improvements to glyoxal VCDs were seen in high anthropogenic emissions regions. In case 2, where molar yields of glyoxal from isoprene were increased five-fold, the resulted concentrations in July were B-B-fold higher, achieving closer agreement between the modeled and measured glyoxal VCDs. The combined changes from both cases 1 and 2 were applied in case B, and the model succeeded in further reducing the underestimations of glyoxal VCDs. However, the results over most of the regions with pronounced anthropogenic emissions were still underestimated. So the molar yields of giyoxal from anthropogenic precursors were considered in case 4. With these additional mole yield changes (a two-fold increase), the improved concentrations agreed better with the measurements in regions of the lower reaches of the Yangtze River and Yellow River in January but not in July.展开更多
The most practical high-temperature proton exchange membranes(PEMs) are phosphoric acid(PA)-doped polymer electrolytes. However, due to the plasticizing effect of PA, it is a challenge to address the trade-off between...The most practical high-temperature proton exchange membranes(PEMs) are phosphoric acid(PA)-doped polymer electrolytes. However, due to the plasticizing effect of PA, it is a challenge to address the trade-off between the proton conductivity and the mechanical performance of these materials. Here,we report an effective strategy to fabricate robust high-temperature PEMs based on the in situ electrostatic crosslinking of polyoxometalates and polymers. A comb copolymer poly(ether-ether-ketone)-grafted-poly(2-ethyl-2-oxazoline)(PGE) with transformable side chains was synthesized and complexed with H_(3)PW_(12)O_(40)(PW) by electrostatic self-assembly, forming PGE/PW nanocomposite membranes with bicontinuous nanostructures. After a subsequent PA-treatment of these membranes, high-temperature PEMs of PGE/PW/PA ternary nanocomposites were obtained, in which the in situ electrostatic crosslinking effect between PW and PGE side chains was generated in the hydrophilic domains of the bicontinuous structures. The microphase separation structure and the electrostatic crosslinking feature endow the PGE/PW/PA membranes with excellent anhydrous proton conductive ability while retaining high mechanical performance. The membranes show a high proton conductivity of 42.5 m S/cm at 150 ℃ and a high tensile strength of 13 MPa. Our strategy can pave a new route based on electrostatic control to design nanostructured polymer electrolytes.展开更多
In the present study, we developed and validated a simple and sensitive gradient elution liquid chromatography tandem mass spectrometry (LC-MS/MS) method for quantification of doxorubicin in rabbit plasma. Daunorubi...In the present study, we developed and validated a simple and sensitive gradient elution liquid chromatography tandem mass spectrometry (LC-MS/MS) method for quantification of doxorubicin in rabbit plasma. Daunorubicin was used as an internal standard (IS). The doxorubicin and IS were extracted with ethyl acetate from plasma samples. The chromatographic separations were achieved on a C18 column (2.1 mm×50 mm, 2.5μm) configured with a C18 guard column (2.1 mm×10 mm, 2.5 μm). The mobile phase of 0.1% formic acid-water solution and acetonitrile was delivered using a gradient elution program at a flow rate of 0.4 mL/min. The temperature for column was maintained at 40 ℃. The electrospray ionization (ESI) source was operated in the positive ion mode, and the quantification was conducted using multiple reaction monitoring (MRM) of the transitions m/z 544.07→396.96 and m/z 528.06→321.05 for doxorubicin and IS, respectively. The calibration curve of doxorubicin was linear (r 〉 0.999) within the range of 2-600 ng/mL. The lower limit of quantification was 2 ng/mL. The relative errors of intra-day and inter-day accuracies ranged from -2.48% to 0.18% and from -3.78% to 1.94%, respectively. The relative standard deviations of intra-day and inter-day precisions were less than 8.65% and 6.41%, respectively. The method exhibited satisfactory results in terms of specificity, sensitivity, matrix effect, recovery and stability. The newly developed LC-MS/MS method was reliable to monitor doxorubicin concentrations in rabbit plasma.展开更多
Background:The involvement of specific basal ganglia-thalamocortical circuits in response inhibition has been extensively mapped in animal models.However,the pivotal nodes and directed causal regulation within this in...Background:The involvement of specific basal ganglia-thalamocortical circuits in response inhibition has been extensively mapped in animal models.However,the pivotal nodes and directed causal regulation within this inhibitory circuit in humans remains con-troversial.Objective:The main aim of the present study was to determine the causal information flow and critical nodes in the basal ganglia-thalamocortical inhibitory circuits and also to examine whether these are modulated by biological factors(i.e.sex)and behavioral performance.Methods:Here,we capitalize on the recent progress in robust and biologically plausible directed causal modeling(DCM-PEB)and a large response inhibition dataset(n=250)acquired with concomitant functional magnetic resonance imaging to determine key nodes,their causal regulation and modulation via biological variables(sex)and inhibitory performance in the inhibitory circuit encompassing the right inferior frontal gyrus(rIFG),caudate nucleus(rCau),globus pallidum(rGP),and thalamus(rThal).Results:The entire neural circuit exhibited high intrinsic connectivity and response inhibition critically increased causal projections from the rIFG to both rCau and rThal.Direct comparison further demonstrated that response inhibition induced an increasing rIFG inflow and increased the causal regulation of this region over the rCau and rThal.In addition,sex and performance influenced the functional architecture of the regulatory circuits such that women displayed increased rThal self-inhibition and decreased rThal to GP modulation,while better inhibitory performance was associated with stronger rThal to rIFG communication.Furthermore,control analyses did not reveal a similar key communication in a left lateralized model.Conclusions:Together,these findings indicate a pivotal role of the rIFG as input and causal regulator of subcortical response inhibition nodes.展开更多
Chlorfenapyr is a broad-spectrum halogenated pyrrole insecticide with a unique mode of action.Due to the misuse and overuse of this chemical,resistance has been reported in several arthropods,including Plutella xylost...Chlorfenapyr is a broad-spectrum halogenated pyrrole insecticide with a unique mode of action.Due to the misuse and overuse of this chemical,resistance has been reported in several arthropods,including Plutella xylostella,which is one of the most destructive insect pests afflicting crucifers worldwide.A better understanding of the cross-resistance and genetics of field-evolved chlorfenapyr resistance could effectively guide resistance management practices.Here,the chlorfenapyr resistance of a fieldderived population of P xylostella was introgressed into the susceptible IPP-S strain using a selection-assisted multigenerational backcrossing approach.The constructed nearisogenic strain,TH-BCsF2,shared 98.4%genetic background with the recurrent parent IPP-S strain.The TH-BCsF2 strain showed 275-fold resistance to chlorfenapyr,but no significant cross-resistance to spinosad,abamectin,chlorpyrifos,β-cypermethrin,indoxacarb,chlorantraniliprole,or broflanilide(no more than 4.2-fold).Genetic analysis revealed that resistance was autosomal,incompletely dominant,and conferred by 1 major gene or a few tightly linked loci.The synergism of metabolic inhibitors(PBO,DEM,and DEF)to chlorfenapyr was very weak(<1.7-fold),and the metabolic enzyme activities in the TH-BCsF2 strain were not significantly elevated compared with the IPP-S strain.The results enhances our understanding of the genetic traits of chlorfenapyr resistance,and provides essential information for improving resistance management strategies.展开更多
The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 3...The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.展开更多
In aerospace industry,gears are the most common parts of a mechanical transmission system.Gear pitting faults could cause the transmission system to crash and give rise to safety disaster.It is always a challenging pr...In aerospace industry,gears are the most common parts of a mechanical transmission system.Gear pitting faults could cause the transmission system to crash and give rise to safety disaster.It is always a challenging problem to diagnose the gear pitting condition directly through the raw signal of vibration.In this paper,a novel method named augmented deep sparse autoencoder(ADSAE)is proposed.The method can be used to diagnose the gear pitting fault with relatively few raw vibration signal data.This method is mainly based on the theory of pitting fault diagnosis and creatively combines with both data augmentation ideology and the deep sparse autoencoder algorithm for the fault diagnosis of gear wear.The effectiveness of the proposed method is validated by experiments of six types of gear pitting conditions.The results show that the ADSAE method can effectively increase the network generalization ability and robustness with very high accuracy.This method can effectively diagnose different gear pitting conditions and show the obvious trend according to the severity of gear wear faults.The results obtained by the ADSAE method proposed in this paper are compared with those obtained by other common deep learning methods.This paper provides an important insight into the field of gear fault diagnosis based on deep learning and has a potential practical application value.展开更多
基金upported by the National Natural Science Foundation of China(No.U1804263,61772549,62172435)the Zhongyuan Science and Technology Innovation Leading Talent Project(No.214200510019)Thanks to the recommendation of SPDE2020,which gives us the opportunity to publish an expanded and full version of this paper.
文摘Privacy protection is the key to maintaining the Internet of Things(IoT)communication strategy.Steganography is an important way to achieve covert communication that protects user data privacy.Steganalysis technology is the key to checking steganography security,and its ultimate goal is to extract embedded messages.Existing methods cannot extract under known cover images.To this end,this paper proposes a method of extracting embedded messages under known cover images.First,the syndrome-trellis encoding process is analyzed.Second,a decoding path in the syndrome trellis is obtained by using the stego sequence and a certain parity-check matrix,while the embedding process is simulated using the cover sequence and parity-check matrix.Since the decoding path obtained by the stego sequence and the correct parity-check matrix is optimal and has the least distortion,comparing the path consistency can quickly filter the coding parameters to determine the correct matrices,and embedded messages can be extracted correctly.The proposed method does not need to embed all possible messages for the second time,improving coding parameter recognition significantly.The experimental results show that the proposed method can identify syndrome-trellis coding parameters in stego images embedded by adaptive steganography quickly to realize embedded message extraction.
基金supported by Beijing University of Chinese Medicine(1000061224003)National Natural Science Foundation of China(81903766,81900603,82104440)。
文摘Objective:To explore the effect and mechanism of action of the Wenjing Zhitong recipe(WZR)in primary dysmenorrhea(PD)treatment.Methods:Uterine contractions were induced by estradiol benzoate and oxytocin in a PD model and WZR was administrated.The rate of change in uterine contractility and the writhing test were used to evaluate the effects of WZR.The serum levels of prostaglandin F_(2a)(PGF_(2a))and prostaglandin E_2(PGE_2),and the activity of cyclooxygenase-2(COX2)were detected by enzyme-linked immunosorbent assay(ELISA).The changes in phosphor-phospholipase C(pPLC/PLC),phosphor-protein kinase C(pPKC/PKC),and connexin 43(CX43)expression were detected using immunohistochemistry and western blot.Results:WZR significantly reduced the rate of change in uterine contractility and writhing times in the PD model.WZR treatment inhibited the enzymatic activity of COX2 and reduced the levels of PGF_(2a),PGF_(2a)/PGE2and COX2 in the PD model.WZR also significantly reduced the expression of pPLC/PLC,pPKC/PKC and CX43.Targeting the inhibition of COX2 activity,caffeic acid and 1-acetyl-β-carboline were validated as the active ingredients in WZR responsible for reducing uterine contractions.Conclusion:WZR attenuated PD by inhibiting COX2 activity,downregulating PGF_(2a)/PGE_2 expression,and inhibiting the PKC signaling pathway.
文摘The financial market is the core of national economic development,and stocks play an important role in the financial market.Analyzing stock prices has become the focus of investors,analysts,and people in related fields.This paper evaluates the volatility of Apple Inc.(AAPL)returns using five generalized autoregressive conditional heteroskedasticity(GARCH)models:sGARCH with constant mean,GARCH with sstd,GJR-GARCH,AR(1)GJR-GARCH,and GJR-GARCH in mean.The distribution of AAPL’s closing price and earnings data was analyzed,and skewed student t-distribution(sstd)and normal distribution(norm)were used to further compare the data distribution of the five models and capture the shape,skewness,and loglikelihood in Model 4-AR(1)GJR-GARCH.Through further analysis,the results showed that Model 4,AR(1)GJR-GARCH,is the optimal model to describe the volatility of the return series of AAPL.The analysis of the research process is both,a process of exploration and reflection.By analyzing the stock price of AAPL,we reflect on the shortcomings of previous analysis methods,clarify the purpose of the experiment,and identify the optimal analysis model.
基金the National Natural Science Foundation of China(Grant Nos.32102310,32202484,and 32072520)the Shandong Key Research and Development Program,China(Grant Nos.2021LZGC007 and 2022TZXD009).
文摘Self-rooted apple stock is widely used for apple production.However,the shallowness of the adventitious roots in self-rooted apple stock leads to poor performance in the barren orchards of China.This is because of the considerable difference in the development of a gravitropic set-point angle(GSA)between self-rooted apple stock and seedling rootstock.Therefore,it is crucial to study the molecular mechanism of adventitious root GSA in self-rooted apple stock for breeding self-rooted and deep-rooted apple rootstock cultivars.An apple auxin response factor MdARF19 functioned to establish the adventitious root GSA of self-rooted apple stock in response to gravity and auxin signals.MdARF19 bound directly to the MdPIN7 promoter,activating its transcriptional expression and thus regulating the formation of the adventitious root GSA in 12-2 self-rooted apple stock.However,MdARF19 influenced the expression of auxin efflux carriers(MdPIN3 and MdPIN10)and the establishment of adventitious root GSA of self-rooted apple stock in response to gravity signals by direct activation of MdFLP.Our findings provide new information on the transcriptional regulation of MdPIN7 by auxin response factor MdARF19 in the regulation of the adventitious root GSA of self-rooted apple stock in response to gravity and auxin signals.
基金funded by the State Grid Hebei Electric Power Co.,Ltd projectthe National Natural Science Foundation of China’s major project,“Research on the Construction of China’s Economic Transformation Mode for Carbon Neutrality(72140001)This study is titled“Research on Novel Power System Development Path”。
文摘Carrying out green energy transformation,implementing clean energy power replacement and supply,and developing a new power system are some primary driving forces needed to fulfill China’s carbon-peak and carbon-neutral strategic goals.The construction of new power systems in China’s provinces and cities is developing rapidly,and the lack of a typical model promotes the application.The new power system path design should be based on the actual development of the power grid in different regions,energy use characteristics,and other actual needs to carry out the differentiated path design.In this context,this study analyzes the characteristics of the new domestic power system based on the policy background of the new domestic power system,constructs a new model for power system development stage identification,and proposes the overall design of the new power system development path from the power supply,transmission and distribution,and load sides.It also uses the Hebei South Network as an example to explore the development stage of the Hebei South Grid based on actual development needs.Finally,this study designs a novel power system development path for the entire supply and demand chain for the Hebei South Grid to propose ideas for constructing a new power system in China and to help green energy transformation.
基金supported by fundings from the National Natural Science Foundation of China(31672170 and 31872950)the Natural Science Foundation of Shandong Province(JQ201309)+1 种基金the Shandong“Double Tops”Program(SYL2017YSTD06)the“Taishan Scholar”Foundation of the People’s Government of Shandong Province(ts20130932).
文摘Flavonols and proanthocyanidins(PAs)are the main pigments in the black spines of cucumber(Cucumis sativus)fruit,and CsMYB60 is a key regulator of the biosynthesis of flavonols and PAs.However,in cucumber,the tissue distribution pattern of flavonols and PAs and the mechanism of their biosynthesis regulated by CsMYB60 remain unclear.In this study,we clarified the tissue-specific distribution of flavonoids and the unique transcriptional regulation of flavonoid biosynthesis in cucumber.CsMYB60 activated CsFLS and CsLAR by binding to their promoters and directly or indirectly promoted the expression of CsbHLH42,CsMYC1,CsWD40,and CsTATA-box binding protein,resulting in the formation of complexes of these four proteins to increase the expression of Cs4CL and interact with CsTATA-box binding protein to regulate the expression of CsCHS,thereby regulating the biosynthesis of flavonols and PAs in cucumber.Our data provide new insights into the molecular mechanism of flavonoid biosynthesis,which will facilitate molecular breeding to improve fruit quality in cucumber.
基金Supported by the Key Deployment Project of Centre for Ocean Mega-Research of Science,Chinese Academy of Sciences(No.COMS2020Q09)the National Key Research and Development Program of China(No.2018YFD0901102)the Science and Technology program of Yantai(No.2017ZH095)。
文摘Synechococcus is one of the most abundant picocyanobacteria in marine ecosystem,and the absence of Prochlorococcus would make it indispensable as a primary producer in the Bohai Sea,North China.However,the abundance distribution and genetic diversity of Synechococcus in this region have rarely been reported.In this study,the distribution pattern of Synechococcus abundance was investigated during four cruises in April,June,August,and November from 2018 to 2019,moreover,its phenogenetic diversity was studied based on high-throughput sequencing of the cpe BA operon.The results demonstrate that phycoerythrin-containing Synechococcus was most abundant in August when temperature was high and oxygen saturation was low.During this period,Synechococcus pigment type(PT)2 was abundant in the Bohai Bay and Laizhou Bay under conditions of high nutrient concentration,temperature,and turbidity.In comparison,PT3,especially those clusters characterized with high or variable ratio of phycourobilin and phycoerythrobilin,was predominant in the Bohai Strait and Liaodong Bay under conditions of high salinity,pH,and oxygen saturation.Furthermore,co-occurrence correlations using network analysis revealed that Synechococcus PTs were related to 15.37%-43.48%of the prokaryotic genera.Synechococcus PT3c/PT3d and PT2 were the most important PTs in the network.The hierarchical clustering revealed that taxa co-occurred with Synechococcus PTs diff ered among samples.It could be attributed to the substance exchange and the environmental impact,which calls for more studies in the future.
基金financially supported by the Scientific and Technology Project of State Grid Corporation of China,Research on Dry Etching Forming Technology of Silicon Carbide Device,Project No.5500-202158437A-0-0-00.
文摘The comparison of domestic and foreign studies has been utilized to extensively employ junction termination extension(JTE)structures for power devices.However,achieving a gradual doping concentration change in the lateral direction is difficult for SiC devices since the diffusion constants of the implanted aluminum ions in SiC are much less than silicon.Many previously reported studies adopted many new structures to solve this problem.Additionally,the JTE structure is strongly sensitive to the ion implantation dose.Thus,GA-JTE,double-zone etched JTE structures,and SM-JTE with modulation spacing were reported to overcome the above shortcomings of the JTE structure and effectively increase the breakdown voltage.They provided a theoretical basis for fabricating terminal structures of 4H-SiC PiN diodes.This paper summarized the effects of different terminal structures on the electrical properties of SiC devices at home and abroad.Presently,the continuous development and breakthrough of terminal technology have significantly improved the breakdown voltage and terminal efficiency of 4H-SiC PiN power diodes.
文摘As the core economic variable in the process of the integration of world economy,the change of the exchange rate has an important impact on the import and export,foreign exchange reserves,interest rates,capital flows and other macro and microeconomic factors.This paper first analyzes the status quo of RMB exchange rate risk and the advanced experience of exchange rate management of other countries.Then,the empirical method is used to analyze the characteristics of RMB exchange rate fluctuation based on the day-frequency data of USD/RMB,GBP/RMB,EUR/RMB and JPY/RMB from December 2011 to December 2016.This paper also respectively uses the GARCH,TARCH,EGARCH and PARCH model to fit four representative foreign currencies against RMB,and selects the optimal model to calculate VaR value.Finally,validity of the data is verified through the Chi-square distribution test.The empirical results show that the four sequences are non-normal and first-order monotonic sequences.Besides,there is a significantly high-order ARCH effect,and the GARCH family model has a better fitting effect.JPY/RMB is with lower exchange rate risk,while the fluctuation of EUR/RMB is significantly greater than other currencies.According to the international situation of financial market,the status quo of RMB exchange rate and the conclusion of empirical research,this paper puts forward that the marketization and internationalization of RMB exchange rate should be based on improving the financial system and environment.It is also suggested that the government should properly intervene in the foreign exchange market and make good use of the risk measurement model and commercial banks should further develop the financial derivatives to hedge the foreign exchange risk.
基金the National Key Research and Development program of China(2022YFC3400700,2022YFA0806400,2021YFC2500100,2020YFE0201600)the Science and Technology Innovation 2030 Major Projects(2022ZD0211600)+5 种基金the Shanghai Rising-Star Program(22QA1404000)Shanghai Municipal Science and Technology Major Project(2017SHZDZX01)the Natural Science Foundation of Shanghai,China(22ZR1405300)the National Natural Science Foundation of China(31821002)the Key Research and Development Plans of Jiangsu Province,China(BE2021696)the Greater Bay Area Institute of Precision Medicine(Guangzhou).
文摘Cardiovascular health metrics are now widely recognized as modifable risk factors for cognitive decline and dementia.Metabolic perturbations might play roles in the linkage of cardiovascular diseases and dementia.Circulating metabolites profling by metabolomics may improve understanding of the potential mechanism by which cardiovascular risk factors contribute to cognitive decline.In a prospective community-based cohort in China(n=725),312 serum metabolic phenotypes were quantifed,and cardiovascular health score was calculated including smoking,exercise,sleep,diet,body mass index,blood pressure,and blood glucose.Cognitive function assessments were conducted in baseline and follow-up visits to identify longitudinal cognitive decline.A better cardiovascular health was signifcantly associated with lower risk of concentration decline and orientation decline(hazard ratio(HR):0.84–0.90;p<0.05).Apolipoprotein-A1,high-density lipoprotein(HDL)cholesterol,cholesterol ester,and phospholipid concentrations were signifcantly associated with a lower risk of longitudinal memory and orientation decline(p<0.05 and adjusted-p<0.20).Mediation analysis suggested that the negative association between health status and the risk of orientation decline was partly mediated by cholesterol ester and total lipids in HDL-2 and-3(proportion of mediation:7.68–8.21%,both p<0.05).Cardiovascular risk factors were associated with greater risks of cognitive decline,which were found to be mediated by circulating lipoproteins,particularly the medium-size HDL components.These fndings underscore the potential of utilizing lipoproteins as targets for early stage dementia screening and intervention.
基金supported by the Science and Technology program of Yantai (No. 2017ZH095)。
文摘Microbial application is an efficient, economical, and ecofriendly method for remediating black-odorous rivers. In this study, the field treatment effect and microbial community changes were monitored during remediation by the acclimated complex microorganisms of a typical black-odorous stream. After the treatment, the total phosphorus and ammonia contents decreased by 74.0% and 76.3% and the concentrations of dissolved oxygen increased from 1.65 to 4.90 mg/L, indicating the effectiveness of the acclimated composite microorganisms. The proportion of Bacteroidetes decreased significantly by 48.1% and that of Firmicutes increased by 2.23% on average, and the microbial diversity index first increased and then tended to be uniform. Redundancy analysis demonstrated that the pH,dissolved oxygen, and oxidation-reduction potential together determined the composition of the microbial communities(p < 0.05). These findings showed that the acclimated composite microorganisms can effectively remediate the black odor.
基金supported by the National Natural Science Foundation of China (No. 91544221)the National Key R&D Programs of China (Nos. 2017YFC0209803, 2017YFC0210000)the CAS Strategic Priority Research Program Grant (No. XDB05020000)
文摘Currently, modeling studies tend to significantly underestimate observed space-based glyoxal (CHOCHO) vertical column densities (VCDs), implying the existence of missing sources of giyoxal. Several recent studies suggest that the emissions of aromatic compounds and molar yields of glyoxal in the chemical mechanisms may both be underestimated, which can affect the simulated glyoxal concentrations. In this study, the influences of these two factors on glyoxal amounts over China were investigated using the RAMS-CMAQ modeling system for January and July 2014. Four sensitivity simulations were performed, and the results were compared to satellite observations. These results demonstrated significant impacts on glyoxal concentrations from these two factors. In case 1, where the emissions of aromatic compounds were increased three-fold, improvements to glyoxal VCDs were seen in high anthropogenic emissions regions. In case 2, where molar yields of glyoxal from isoprene were increased five-fold, the resulted concentrations in July were B-B-fold higher, achieving closer agreement between the modeled and measured glyoxal VCDs. The combined changes from both cases 1 and 2 were applied in case B, and the model succeeded in further reducing the underestimations of glyoxal VCDs. However, the results over most of the regions with pronounced anthropogenic emissions were still underestimated. So the molar yields of giyoxal from anthropogenic precursors were considered in case 4. With these additional mole yield changes (a two-fold increase), the improved concentrations agreed better with the measurements in regions of the lower reaches of the Yangtze River and Yellow River in January but not in July.
基金financial support from the National Natural Science Foundation of China (No. 22075097)the Program for JLU Science and Technology Innovative Research Team (No. 2017TD-10)the Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences (No. 2020–09)。
文摘The most practical high-temperature proton exchange membranes(PEMs) are phosphoric acid(PA)-doped polymer electrolytes. However, due to the plasticizing effect of PA, it is a challenge to address the trade-off between the proton conductivity and the mechanical performance of these materials. Here,we report an effective strategy to fabricate robust high-temperature PEMs based on the in situ electrostatic crosslinking of polyoxometalates and polymers. A comb copolymer poly(ether-ether-ketone)-grafted-poly(2-ethyl-2-oxazoline)(PGE) with transformable side chains was synthesized and complexed with H_(3)PW_(12)O_(40)(PW) by electrostatic self-assembly, forming PGE/PW nanocomposite membranes with bicontinuous nanostructures. After a subsequent PA-treatment of these membranes, high-temperature PEMs of PGE/PW/PA ternary nanocomposites were obtained, in which the in situ electrostatic crosslinking effect between PW and PGE side chains was generated in the hydrophilic domains of the bicontinuous structures. The microphase separation structure and the electrostatic crosslinking feature endow the PGE/PW/PA membranes with excellent anhydrous proton conductive ability while retaining high mechanical performance. The membranes show a high proton conductivity of 42.5 m S/cm at 150 ℃ and a high tensile strength of 13 MPa. Our strategy can pave a new route based on electrostatic control to design nanostructured polymer electrolytes.
基金National Natural Science Foundation of China( Grant No.81571779).
文摘In the present study, we developed and validated a simple and sensitive gradient elution liquid chromatography tandem mass spectrometry (LC-MS/MS) method for quantification of doxorubicin in rabbit plasma. Daunorubicin was used as an internal standard (IS). The doxorubicin and IS were extracted with ethyl acetate from plasma samples. The chromatographic separations were achieved on a C18 column (2.1 mm×50 mm, 2.5μm) configured with a C18 guard column (2.1 mm×10 mm, 2.5 μm). The mobile phase of 0.1% formic acid-water solution and acetonitrile was delivered using a gradient elution program at a flow rate of 0.4 mL/min. The temperature for column was maintained at 40 ℃. The electrospray ionization (ESI) source was operated in the positive ion mode, and the quantification was conducted using multiple reaction monitoring (MRM) of the transitions m/z 544.07→396.96 and m/z 528.06→321.05 for doxorubicin and IS, respectively. The calibration curve of doxorubicin was linear (r 〉 0.999) within the range of 2-600 ng/mL. The lower limit of quantification was 2 ng/mL. The relative errors of intra-day and inter-day accuracies ranged from -2.48% to 0.18% and from -3.78% to 1.94%, respectively. The relative standard deviations of intra-day and inter-day precisions were less than 8.65% and 6.41%, respectively. The method exhibited satisfactory results in terms of specificity, sensitivity, matrix effect, recovery and stability. The newly developed LC-MS/MS method was reliable to monitor doxorubicin concentrations in rabbit plasma.
基金supported by the by the National Key Research and Development Program of China (grant number:2018YFA0701400-BB)National Natural Science Foundation of China (grant numbers 31530032-KMK,91632117-BB,32200904 Qian Zhuang)Key Technological Projects of Guangdong Province (grant number 2018B030335001-KMK).
文摘Background:The involvement of specific basal ganglia-thalamocortical circuits in response inhibition has been extensively mapped in animal models.However,the pivotal nodes and directed causal regulation within this inhibitory circuit in humans remains con-troversial.Objective:The main aim of the present study was to determine the causal information flow and critical nodes in the basal ganglia-thalamocortical inhibitory circuits and also to examine whether these are modulated by biological factors(i.e.sex)and behavioral performance.Methods:Here,we capitalize on the recent progress in robust and biologically plausible directed causal modeling(DCM-PEB)and a large response inhibition dataset(n=250)acquired with concomitant functional magnetic resonance imaging to determine key nodes,their causal regulation and modulation via biological variables(sex)and inhibitory performance in the inhibitory circuit encompassing the right inferior frontal gyrus(rIFG),caudate nucleus(rCau),globus pallidum(rGP),and thalamus(rThal).Results:The entire neural circuit exhibited high intrinsic connectivity and response inhibition critically increased causal projections from the rIFG to both rCau and rThal.Direct comparison further demonstrated that response inhibition induced an increasing rIFG inflow and increased the causal regulation of this region over the rCau and rThal.In addition,sex and performance influenced the functional architecture of the regulatory circuits such that women displayed increased rThal self-inhibition and decreased rThal to GP modulation,while better inhibitory performance was associated with stronger rThal to rIFG communication.Furthermore,control analyses did not reveal a similar key communication in a left lateralized model.Conclusions:Together,these findings indicate a pivotal role of the rIFG as input and causal regulator of subcortical response inhibition nodes.
基金supported by the National Natural Science Foundation of China(32072454)the Guidance Foundation of Sanya Institute of Nanjing Agricultural University(NAUSY-MS09).
文摘Chlorfenapyr is a broad-spectrum halogenated pyrrole insecticide with a unique mode of action.Due to the misuse and overuse of this chemical,resistance has been reported in several arthropods,including Plutella xylostella,which is one of the most destructive insect pests afflicting crucifers worldwide.A better understanding of the cross-resistance and genetics of field-evolved chlorfenapyr resistance could effectively guide resistance management practices.Here,the chlorfenapyr resistance of a fieldderived population of P xylostella was introgressed into the susceptible IPP-S strain using a selection-assisted multigenerational backcrossing approach.The constructed nearisogenic strain,TH-BCsF2,shared 98.4%genetic background with the recurrent parent IPP-S strain.The TH-BCsF2 strain showed 275-fold resistance to chlorfenapyr,but no significant cross-resistance to spinosad,abamectin,chlorpyrifos,β-cypermethrin,indoxacarb,chlorantraniliprole,or broflanilide(no more than 4.2-fold).Genetic analysis revealed that resistance was autosomal,incompletely dominant,and conferred by 1 major gene or a few tightly linked loci.The synergism of metabolic inhibitors(PBO,DEM,and DEF)to chlorfenapyr was very weak(<1.7-fold),and the metabolic enzyme activities in the TH-BCsF2 strain were not significantly elevated compared with the IPP-S strain.The results enhances our understanding of the genetic traits of chlorfenapyr resistance,and provides essential information for improving resistance management strategies.
基金support from diverse funding sources,including the National Key Program for S&T Research and Development of the Ministry of Science and Technology(MOST),Yifang Wang's Science Studio of the Ten Thousand Talents Project,the CAS Key Foreign Cooperation Grant,the National Natural Science Foundation of China(NSFC)Beijing Municipal Science&Technology Commission,the CAS Focused Science Grant,the IHEP Innovation Grant,the CAS Lead Special Training Programthe CAS Center for Excellence in Particle Physics,the CAS International Partnership Program,and the CAS/SAFEA International Partnership Program for Creative Research Teams.
文摘The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.
基金supported by the Natural Science Foundation of China(No.51675089).
文摘In aerospace industry,gears are the most common parts of a mechanical transmission system.Gear pitting faults could cause the transmission system to crash and give rise to safety disaster.It is always a challenging problem to diagnose the gear pitting condition directly through the raw signal of vibration.In this paper,a novel method named augmented deep sparse autoencoder(ADSAE)is proposed.The method can be used to diagnose the gear pitting fault with relatively few raw vibration signal data.This method is mainly based on the theory of pitting fault diagnosis and creatively combines with both data augmentation ideology and the deep sparse autoencoder algorithm for the fault diagnosis of gear wear.The effectiveness of the proposed method is validated by experiments of six types of gear pitting conditions.The results show that the ADSAE method can effectively increase the network generalization ability and robustness with very high accuracy.This method can effectively diagnose different gear pitting conditions and show the obvious trend according to the severity of gear wear faults.The results obtained by the ADSAE method proposed in this paper are compared with those obtained by other common deep learning methods.This paper provides an important insight into the field of gear fault diagnosis based on deep learning and has a potential practical application value.