Fermi-LAT LCR provides continuous and regularly sampled gamma-ray light curves, spanning about 14 yr, for a large sample of blazars. The log-normal flux distribution and linear rms–flux relation of the light curves f...Fermi-LAT LCR provides continuous and regularly sampled gamma-ray light curves, spanning about 14 yr, for a large sample of blazars. The log-normal flux distribution and linear rms–flux relation of the light curves for a few Fermi blazars have been examined in previous studies. However, the probability that blazars exhibit the log-normal flux distribution and linear rms–flux relation in their gamma-ray light curves has not been systematically explored.In this study, we comprehensively research the distribution of γ-ray flux and the statistical characteristics on a large sample of 1414 variable blazars from the Fermi-LAT LCR catalog, including 572 FSRQs, 477 BL Lacs, and 365BCUs, and statistically compare their flux distributions with normal and log-normal distributions. The results indicate that the probability of not rejecting log-normal is 42.05% for the large sample, and there is still a 2.05%probability of not rejecting normality, based on the joint of Kolmogorov–Smirnov, Shapiro–Wilk, and Normality tests. We further find that the probability that BL Lacs conform to the log-normal distribution is higher than that of FSRQs. Besides, after removing sources with less than 200 data points from this large sample, a sample of 549blazars, which is still a large sample compared to the previous studies, was obtained. Based on dividing the light curves into segments every 20 points(or 40 points, or one year), we fitted the linear rms–flux relation of these three different sets and found that the Pearson correlation coefficients are all close to 1 for most blazars. This result indicates a strong linear correlation between the rms and the flux of these 549 blazars. The log-normal distribution and linear rms–flux relation indicate that the variability of the γ-ray flux for most blazars is a non-linear and multiplicative process.展开更多
In this work,we report for the first time two repeated quasi-periodic oscillations(QPOs)in the light curve of the Flat Spectrum Radio Quasar S51044+71.This source was observed by the Transiting Exoplanet Survey Satell...In this work,we report for the first time two repeated quasi-periodic oscillations(QPOs)in the light curve of the Flat Spectrum Radio Quasar S51044+71.This source was observed by the Transiting Exoplanet Survey Satellite in multiple sectors.We used the generalized Lomb-Scargle periodogram method and weighted wavelet Z-transform method to search for significant periodic signals.The main results are as follows:We found QPOs of~7.0 days(persisted for 4 cycles,with a significance of~3.5σ)and~7.3 days(persisted for 5 cycles,with a significance of~3.8σ)in the light curves of Sector 47 and EP1,respectively.Considering range of error,we regard them to be the same.We discussed two likely models of these rapid quasi-periodic variations:One comes from the jet and the other from the accretion disk.For the first one,we consider kink instability of the jet as a plausible explanation.Second,the QPO probably comes from the main hot spots in the accretion disk,which are located approximately within the innermost stable circular orbit allowed by general relativity.Based on this model,we estimate the mass of the black hole in S51044+71 to be 3.49×10^(9)M☉.展开更多
OBJECTIVE:To investigate the effect of moxibustion on synovitis and the autophagy of synoviocytes in rheumatoid arthritis(RA).METHODS:Forty Sprague-Dawley rats were randomly divided into a normal group,model group,mox...OBJECTIVE:To investigate the effect of moxibustion on synovitis and the autophagy of synoviocytes in rheumatoid arthritis(RA).METHODS:Forty Sprague-Dawley rats were randomly divided into a normal group,model group,moxibustion group,cigarette moxibustion group,and medicine group,with eight rats included in each group.The RA model was established by subcutaneous injection of complete Freund's adjuvant into the left posterior toe.Rats in the model group were not interfered with.In the moxibustion group,rats were treated by moxibustion,where a 1-cm diameter moxa stick was applied at the left Zusanli(ST 36)point.The distance of the moxa stick to the skin was 2 cm and moxibustion was completed for 20 min daily for 15 d total.In the cigarette moxibustion group,the moxa stick was replaced by a common cigarette.In the medicine group,rats were treated with a tripterygium glycoside suspension(8 mg/kg)once a day for 15 d total.In each group,the left hind limb toe volume was measured with a toe volume meter;the synovial cells were observed by hematoxylin and eosin staining;the interleukin(IL)-4,IL-6,IL-10,IL-1β,IL-23,IL-17,and tumor necrosis factor(TNF)-αlevels in serum were measured by enzyme-linked immunosorbent assay;the erythrocyte sedimentation rate(ESR)were detected by Westergren sedimentation rate testing;the C-reactive protein(CRP)and rheumatoid factor(RF)levels in serum were detected by rate nephelometry;the expression levels of ULK1,autophagy-associated protein(Atg)3,Atg5,and Atg12 messenger RNA(m RNA)in synovium were detected by real time-quantitative polymerase chain reaction(RT-q PCR);and the protein expression levels of phosphatidylinositol-3-kinase(PI3K),protein kinase B(Akt),mammalian target of rapamycin(mTOR),LC3-Ⅱ,beclin-1,phosphorylated-PI3K(p-PI3K),p-Akt,p-mTOR in synovium were detected by Western blotting.RESULTS:Among the RA model rats,joint swelling,an inflammatory reaction,and the proliferation of synovial tissue were obvious and the signal of the PI3K/Akt/mTOR pathway was active,while autophagy was inhibited.Moxibustion at Zusanli(ST36)or intragastric administration of Tripterygium wilfordii glycosides could alleviate the inflammatory reaction of RA rats;relieve the swelling of the toes;downregulate the levels of ESR,CRF,RF;lower the levels of IL-6,IL-1β,TNF-α,and IL-17;and increase the IL-4 and IL-10.At the same time,the m RNA expression levels of ULK1,Atg3,Atg5,and Atg12 and those of LC3-Ⅱand beclin-1 were increased,while the PI3K,Akt,mTOR,p-PI3K,p-Akt,p-mTOR were decreased.Cigarette moxibustion did not significantly reduce the swelling of the toe joint in RA rats,and was not as good as that of moxibustion or Tripterygium wilfordii polyglycosides in the effects of inflammation relief and the influences of the levels of ESR,CRF,RF.While cigarette moxibustion has a weak effect to affect the expression of corresponding molecules in autophages and the expression level of the autophagy biomaker in synovial tissue.Moxibustion and tripterygium glycosides can significantly reduce the joint swelling,relieve synovitis and synovial hyperplasia,and inhibit the PI3K/Akt/mTOR signaling pathway to increase autophagy in a manner superior to cigarette moxibustion.CONCLUSION:Moxibustion can limit the proliferation of synoviocytes in RA rats by inhibiting the PI3K/Akt/mTOR signaling pathway,promoting autophagy,effectively reducing synovitis,and alleviating joint swelling.展开更多
In the current study,the ecosystem services(ES) of conventional and organic rice paddies in Wannian,Jiangxi Province,China are investigated.First,the ES at the field level under organic and conventional paddies were i...In the current study,the ecosystem services(ES) of conventional and organic rice paddies in Wannian,Jiangxi Province,China are investigated.First,the ES at the field level under organic and conventional paddies were investigated.Total economic value of ES in organic rice paddies was 30093.08 yuan RMB/ha per year and that of conventional rice paddies was 22 793.31 yuan RMB/ha per year.The total indirect value of ES was 14 813.7 yuan RMB/ha per year in organic rice paddies and 12 424.56 yuan RMB/ha per year in conventional ones.There were significant differences between organic and conventional rice paddies for the economic values.Then,this economic information was used to extrapolate and to calculate the total and indirect value of ES from rice paddies in Wangnian.The total and indirect economic values of ES from conventional rice paddies in Wannian were 6791 million and 3702 million yuan RMB per year respectively,and the total and indirect economic values of ES from organic rice paddies in Wannian were 1311 million and 646 million yuan RMB per year.If half the area had being converted to organic farming in Wannian,the total and indirect economic values of ES from conventional rice paddies were 3397 million and 1851 million yuan RMB per year,and the total and indirect economic values of ES from organic rice paddies were 5794 million and 2852 million yuan RMB per year.Finally,the total economic value of ES in rice paddies in Wannian was demonstrated through geographic information system techniques.展开更多
As compact and efficient heat exchange equipment,helically coiled tube-in-tube heat exchangers(HCTT heat exchangers)are widely used in many industrial processes.However,the thermal-hydraulic research of liquefied natu...As compact and efficient heat exchange equipment,helically coiled tube-in-tube heat exchangers(HCTT heat exchangers)are widely used in many industrial processes.However,the thermal-hydraulic research of liquefied natural gas(LNG)as the working fluid inHCTT heat exchangers is rarely reported.In this paper,the characteristics of HCTT heat exchangers,in which LNG flows in the inner tube and ethylene glycol-water solution flows in the outer tube,are studied by numerical simulations.The influences of heat transfer characteristics and pressure drops of the HCTT heat transfers are studied by changing the initial flow velocity,the helical middle diameter,and the helical pitch.The results indicate that different initial flow velocities in the inner tube and the outer tube of the HCTT heat exchanger have little influence on the secondary flow of the fluid in the helical tubes,and the overall flow characteristics tend to be stable.The smaller helical middle diameter of the HCTT heat exchanger leads to the shorter fluid flow length,the smaller resistance along the tubes and the increase of initial pressure under the condition of constant inlet velocity,which promotes the occurrence of secondary flow.The axial flow of fluid promotes the destruction of heat transfer boundary layer and gains strength of the turbulence and heat transfer efficiency.With the increase of the helical pitch of the HCTT heat exchanger,the turbulent intensity and the heat transfer efficiency are also increased.Moreover,the improvement of the flow state of the HCTT exchanger in a longer helical pitch also enhances the heat exchange efficiency.展开更多
Helically coiled tube-in-tube(HCTT)heat exchangers are widely applied to the process technology because of their compactness and higher heat transfer efficiency.HCTT heat exchangers play an important role in liquified...Helically coiled tube-in-tube(HCTT)heat exchangers are widely applied to the process technology because of their compactness and higher heat transfer efficiency.HCTT heat exchangers play an important role in liquified natural gas(LNG)use and cold energy recovery.The heat transfer characteristics,pressure distribution,and degree of vaporization of LNG in HCTT heat exchangers are numerically investigated.By comparing the simulation results of the computational model with existing experimental results,the effectiveness of the computational model is verified.The numerical simulation results show the vapor volume fraction of the HCTT heat exchanger is related to the inlet Reynolds number,inner tube diameters,and helix diameter.The vapor volume fraction increases rapidly from the fourth to the seventh equal division points of the helix tube length.On condition that the inlet Reynolds number is greater than 33500,the pressure drop rate gradually increases.When the magnitude of the vapor volume fraction is below 0.2,the heat transfer coefficient increase rate is greater than that when the vapor volume fraction is above 0.2.The heat exchange efficiency of HCTT heat exchangers increases with the decrease of the ratio of helix diameter to inner tube diameter.展开更多
基金funded by the National Natural Science Foundation of China (grants 12063007 and 11863007)。
文摘Fermi-LAT LCR provides continuous and regularly sampled gamma-ray light curves, spanning about 14 yr, for a large sample of blazars. The log-normal flux distribution and linear rms–flux relation of the light curves for a few Fermi blazars have been examined in previous studies. However, the probability that blazars exhibit the log-normal flux distribution and linear rms–flux relation in their gamma-ray light curves has not been systematically explored.In this study, we comprehensively research the distribution of γ-ray flux and the statistical characteristics on a large sample of 1414 variable blazars from the Fermi-LAT LCR catalog, including 572 FSRQs, 477 BL Lacs, and 365BCUs, and statistically compare their flux distributions with normal and log-normal distributions. The results indicate that the probability of not rejecting log-normal is 42.05% for the large sample, and there is still a 2.05%probability of not rejecting normality, based on the joint of Kolmogorov–Smirnov, Shapiro–Wilk, and Normality tests. We further find that the probability that BL Lacs conform to the log-normal distribution is higher than that of FSRQs. Besides, after removing sources with less than 200 data points from this large sample, a sample of 549blazars, which is still a large sample compared to the previous studies, was obtained. Based on dividing the light curves into segments every 20 points(or 40 points, or one year), we fitted the linear rms–flux relation of these three different sets and found that the Pearson correlation coefficients are all close to 1 for most blazars. This result indicates a strong linear correlation between the rms and the flux of these 549 blazars. The log-normal distribution and linear rms–flux relation indicate that the variability of the γ-ray flux for most blazars is a non-linear and multiplicative process.
基金supported by the National Natural Science Foundation of China(NSFC,Grant Nos.12203041,12063007,and 11863007)Yunnan Province China-Malaysia HF-VHF Advanced Radio Astronomy Technology International Joint Laboratory(No.202303AP140003)。
文摘In this work,we report for the first time two repeated quasi-periodic oscillations(QPOs)in the light curve of the Flat Spectrum Radio Quasar S51044+71.This source was observed by the Transiting Exoplanet Survey Satellite in multiple sectors.We used the generalized Lomb-Scargle periodogram method and weighted wavelet Z-transform method to search for significant periodic signals.The main results are as follows:We found QPOs of~7.0 days(persisted for 4 cycles,with a significance of~3.5σ)and~7.3 days(persisted for 5 cycles,with a significance of~3.8σ)in the light curves of Sector 47 and EP1,respectively.Considering range of error,we regard them to be the same.We discussed two likely models of these rapid quasi-periodic variations:One comes from the jet and the other from the accretion disk.For the first one,we consider kink instability of the jet as a plausible explanation.Second,the QPO probably comes from the main hot spots in the accretion disk,which are located approximately within the innermost stable circular orbit allowed by general relativity.Based on this model,we estimate the mass of the black hole in S51044+71 to be 3.49×10^(9)M☉.
基金Supported by the University Natural Science Research Program of Jiangsu:Study on the Mechanism Of Moxibustion Regulating Autophagy in RA synovial Fibroblasts Based on PI3K/Akt/mTOR Pathway(No.18KJB360005)the 973 Program of China:Effect and Biological Mechanism of Heat,Light and Smoking in Moxibustion(No.2015CB554504)+1 种基金funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(Integration of Chinese and Western Medicine)the Exploration and Scientific Research Project of Anhui University of Chinese Medicine:Clinical Application and Mechanism Study of Moxibustion(No.2016ts024)。
文摘OBJECTIVE:To investigate the effect of moxibustion on synovitis and the autophagy of synoviocytes in rheumatoid arthritis(RA).METHODS:Forty Sprague-Dawley rats were randomly divided into a normal group,model group,moxibustion group,cigarette moxibustion group,and medicine group,with eight rats included in each group.The RA model was established by subcutaneous injection of complete Freund's adjuvant into the left posterior toe.Rats in the model group were not interfered with.In the moxibustion group,rats were treated by moxibustion,where a 1-cm diameter moxa stick was applied at the left Zusanli(ST 36)point.The distance of the moxa stick to the skin was 2 cm and moxibustion was completed for 20 min daily for 15 d total.In the cigarette moxibustion group,the moxa stick was replaced by a common cigarette.In the medicine group,rats were treated with a tripterygium glycoside suspension(8 mg/kg)once a day for 15 d total.In each group,the left hind limb toe volume was measured with a toe volume meter;the synovial cells were observed by hematoxylin and eosin staining;the interleukin(IL)-4,IL-6,IL-10,IL-1β,IL-23,IL-17,and tumor necrosis factor(TNF)-αlevels in serum were measured by enzyme-linked immunosorbent assay;the erythrocyte sedimentation rate(ESR)were detected by Westergren sedimentation rate testing;the C-reactive protein(CRP)and rheumatoid factor(RF)levels in serum were detected by rate nephelometry;the expression levels of ULK1,autophagy-associated protein(Atg)3,Atg5,and Atg12 messenger RNA(m RNA)in synovium were detected by real time-quantitative polymerase chain reaction(RT-q PCR);and the protein expression levels of phosphatidylinositol-3-kinase(PI3K),protein kinase B(Akt),mammalian target of rapamycin(mTOR),LC3-Ⅱ,beclin-1,phosphorylated-PI3K(p-PI3K),p-Akt,p-mTOR in synovium were detected by Western blotting.RESULTS:Among the RA model rats,joint swelling,an inflammatory reaction,and the proliferation of synovial tissue were obvious and the signal of the PI3K/Akt/mTOR pathway was active,while autophagy was inhibited.Moxibustion at Zusanli(ST36)or intragastric administration of Tripterygium wilfordii glycosides could alleviate the inflammatory reaction of RA rats;relieve the swelling of the toes;downregulate the levels of ESR,CRF,RF;lower the levels of IL-6,IL-1β,TNF-α,and IL-17;and increase the IL-4 and IL-10.At the same time,the m RNA expression levels of ULK1,Atg3,Atg5,and Atg12 and those of LC3-Ⅱand beclin-1 were increased,while the PI3K,Akt,mTOR,p-PI3K,p-Akt,p-mTOR were decreased.Cigarette moxibustion did not significantly reduce the swelling of the toe joint in RA rats,and was not as good as that of moxibustion or Tripterygium wilfordii polyglycosides in the effects of inflammation relief and the influences of the levels of ESR,CRF,RF.While cigarette moxibustion has a weak effect to affect the expression of corresponding molecules in autophages and the expression level of the autophagy biomaker in synovial tissue.Moxibustion and tripterygium glycosides can significantly reduce the joint swelling,relieve synovitis and synovial hyperplasia,and inhibit the PI3K/Akt/mTOR signaling pathway to increase autophagy in a manner superior to cigarette moxibustion.CONCLUSION:Moxibustion can limit the proliferation of synoviocytes in RA rats by inhibiting the PI3K/Akt/mTOR signaling pathway,promoting autophagy,effectively reducing synovitis,and alleviating joint swelling.
基金supported by GEF/FAO project"Rice-fish GIAHS Conservation and Adaptive Management"(GCP/GCO/212/GEF)
文摘In the current study,the ecosystem services(ES) of conventional and organic rice paddies in Wannian,Jiangxi Province,China are investigated.First,the ES at the field level under organic and conventional paddies were investigated.Total economic value of ES in organic rice paddies was 30093.08 yuan RMB/ha per year and that of conventional rice paddies was 22 793.31 yuan RMB/ha per year.The total indirect value of ES was 14 813.7 yuan RMB/ha per year in organic rice paddies and 12 424.56 yuan RMB/ha per year in conventional ones.There were significant differences between organic and conventional rice paddies for the economic values.Then,this economic information was used to extrapolate and to calculate the total and indirect value of ES from rice paddies in Wangnian.The total and indirect economic values of ES from conventional rice paddies in Wannian were 6791 million and 3702 million yuan RMB per year respectively,and the total and indirect economic values of ES from organic rice paddies in Wannian were 1311 million and 646 million yuan RMB per year.If half the area had being converted to organic farming in Wannian,the total and indirect economic values of ES from conventional rice paddies were 3397 million and 1851 million yuan RMB per year,and the total and indirect economic values of ES from organic rice paddies were 5794 million and 2852 million yuan RMB per year.Finally,the total economic value of ES in rice paddies in Wannian was demonstrated through geographic information system techniques.
基金supported by Innovative Team Introduction Projects for New Universities in Jinan City(No.2021GXRC075).
文摘As compact and efficient heat exchange equipment,helically coiled tube-in-tube heat exchangers(HCTT heat exchangers)are widely used in many industrial processes.However,the thermal-hydraulic research of liquefied natural gas(LNG)as the working fluid inHCTT heat exchangers is rarely reported.In this paper,the characteristics of HCTT heat exchangers,in which LNG flows in the inner tube and ethylene glycol-water solution flows in the outer tube,are studied by numerical simulations.The influences of heat transfer characteristics and pressure drops of the HCTT heat transfers are studied by changing the initial flow velocity,the helical middle diameter,and the helical pitch.The results indicate that different initial flow velocities in the inner tube and the outer tube of the HCTT heat exchanger have little influence on the secondary flow of the fluid in the helical tubes,and the overall flow characteristics tend to be stable.The smaller helical middle diameter of the HCTT heat exchanger leads to the shorter fluid flow length,the smaller resistance along the tubes and the increase of initial pressure under the condition of constant inlet velocity,which promotes the occurrence of secondary flow.The axial flow of fluid promotes the destruction of heat transfer boundary layer and gains strength of the turbulence and heat transfer efficiency.With the increase of the helical pitch of the HCTT heat exchanger,the turbulent intensity and the heat transfer efficiency are also increased.Moreover,the improvement of the flow state of the HCTT exchanger in a longer helical pitch also enhances the heat exchange efficiency.
基金supported by Innovative Team Introduction Projects for New Universities in Jinan City(No.2021GXRC075).
文摘Helically coiled tube-in-tube(HCTT)heat exchangers are widely applied to the process technology because of their compactness and higher heat transfer efficiency.HCTT heat exchangers play an important role in liquified natural gas(LNG)use and cold energy recovery.The heat transfer characteristics,pressure distribution,and degree of vaporization of LNG in HCTT heat exchangers are numerically investigated.By comparing the simulation results of the computational model with existing experimental results,the effectiveness of the computational model is verified.The numerical simulation results show the vapor volume fraction of the HCTT heat exchanger is related to the inlet Reynolds number,inner tube diameters,and helix diameter.The vapor volume fraction increases rapidly from the fourth to the seventh equal division points of the helix tube length.On condition that the inlet Reynolds number is greater than 33500,the pressure drop rate gradually increases.When the magnitude of the vapor volume fraction is below 0.2,the heat transfer coefficient increase rate is greater than that when the vapor volume fraction is above 0.2.The heat exchange efficiency of HCTT heat exchangers increases with the decrease of the ratio of helix diameter to inner tube diameter.
