We investigated the sebaceous gland metaplasia(SGM) of the esophagus and clarified the evidence of misdiagnosis and its diagnosis pitfall. Cases of pathologically proven SGM were enrolled in the clinical analysis and ...We investigated the sebaceous gland metaplasia(SGM) of the esophagus and clarified the evidence of misdiagnosis and its diagnosis pitfall. Cases of pathologically proven SGM were enrolled in the clinical analysis and reviewed description of endoscope. In the current study, we demonstrated that SGM is very rare esophageal condition with an incidence around 0.00465% and an occurrence rate of 0.41 per year. There were 57.1% of senior endoscopists identified 8 episodes of SGM. In contrast, 7.7% of junior endoscopists identified SGM in only 2 episodes. Moreover, we investigated the difference in endoscopic biopsy attempt rate between the senior and junior endoscopist(P = 0.0001). The senior endoscopists had more motivation to look for SGM than did junior endoscopists(P = 0.01). We concluded that SGM of the esophagus is rare condition that is easily and not recognized in endoscopy studies omitting pathological review.展开更多
A concise definition of Transport Efficiency (TE) was given to examine the amount of transported grains in the pipe flow with certain energy consumption. The transport characteristics and the so-called 'roto-float...A concise definition of Transport Efficiency (TE) was given to examine the amount of transported grains in the pipe flow with certain energy consumption. The transport characteristics and the so-called 'roto-floating' characteristics were studied from the tests of sediment transport in the normal pipe flow and the spiral pipe flow, and hereby the energy gradients of the two kinds of pipe flows were obtained. By comparing the mean concentrations at the same gradient, it was concluded that the TE of the latter is several times to over ten times higher than that of the former, and the lift of the latter is 200 times larger than that of the former for the nearly same TE. The spiral flow in circular pipe is suitable for transporting fine grains of high concentration, and with sedimentation trend and coarse grains.展开更多
We calculate the D→P transition form factors within the framework of the light-cone QCD sum rules(LCSR)with the D-meson light-cone distribution amplitudes(LCDAs).The next-to-leading power(NLP)corrections to the vacuu...We calculate the D→P transition form factors within the framework of the light-cone QCD sum rules(LCSR)with the D-meson light-cone distribution amplitudes(LCDAs).The next-to-leading power(NLP)corrections to the vacuum-to-D-meson correlation function are considered,and the NLP corrections from the high-twist D-meson LCDAs and the SU(3)breaking effect from a strange quark mass are investigated.Adopting the exponential model of the D-meson LCDAs,the SU(3)flavor symmetry breaking effects are predicted as R+,0 SU(3)=1.12 and R T SU(3)=1.39,respectively,confirming the results obtained from LCSR with pion LCDA.The numerical predictions of the form factors show that the contribution from two-particle higher-twist contributions is of great importance and the uncertainties are dominated by the inverse moment ofϕ+D(ω,μ).With the obtained form factors,the predicted Cabibbo-Kobayashi-Maskawa(CKM)matrix elements are|Vcd|=0.151+0.091−0.043|th.+0.017−0.02|exp.and|Vcs|=0.89+0.467−0.234|th.+0.008−0.008|exp..展开更多
In this work,we calculate the sub-leading power contributions to radiative leptonic D→γνdecay.For the first time,we provide the analytic expressions of next-to-leading power contributions and the error estimation a...In this work,we calculate the sub-leading power contributions to radiative leptonic D→γνdecay.For the first time,we provide the analytic expressions of next-to-leading power contributions and the error estimation associated with the power expansion of O(∧_(QCD)/m_(c)).In our calculation,we adopt two different models of the D-meson distribution amplitudesφ^(+)_(D,Ⅰ)andφ^(+)_(DⅡ).Within the framework of QCD factorization as well as the dispersion relation,we evaluate the soft contribution up to the next-to-leading logarithmic accuracy and also consider the higher-twist contribution from the two-particle and three-particle distribution amplitudes.Finally,we find that all the sub-leading power contributions are significant atλd(μ0)354 MeV,and the next-to-leading power contributions lead to 143%inφ^(+)_(D,Ⅰ)and 120%inφ^(+)_(DⅡ)corrections to leading power vector form factors with Eγ=0.5 GeV.As the corrections from the higher-twist and local sub-leading power contributions are enhanced with increasing inverse moment,it is difficult to extract an appropriate inverse moment of the D-meson distribution amplitude.The predicted branching fractions are(1.88^(+0.36)_(0.29))×10^(-5)forφ^(+)_(D,Ⅰ)and(2.31^(+0.65)_(-0.54))×10^(-5)forφ^(+)_(DⅡ).展开更多
为了探索适用于国内垃圾焚烧的烟气再循环(exhaust gas recirculation,EGR)技术路线,适应日益提高的NO_(X)排放要求,本文以国内某垃圾焚烧厂为例,采用CFD模拟等方法,研究了EGR系统再循环比例、取风口位置等工艺设计要点,并通过工程试验...为了探索适用于国内垃圾焚烧的烟气再循环(exhaust gas recirculation,EGR)技术路线,适应日益提高的NO_(X)排放要求,本文以国内某垃圾焚烧厂为例,采用CFD模拟等方法,研究了EGR系统再循环比例、取风口位置等工艺设计要点,并通过工程试验评估了EGR系统的脱硝效果及其对锅炉效率和燃烧稳定性的影响。结果表明,“SNCR+EGR”工艺能够将NO_(X)值降低至100 mg/Nm^(3)(11%O_(2)、干基)以下,且相比传统工艺焚烧线,采用EGR工艺的焚烧线吨垃圾产汽量提高3.29%。另外,EGR系统运行时,焚烧炉燃烧充分,CO浓度稳定达标。同时,炉膛温度可降低约50℃,有利于减少炉内结焦,延长耐火材料使用寿命。但是,系统运行控制要求较高且存在设备腐蚀风险。本研究为垃圾焚烧脱硝工艺的选择提供了新的方向,对于NO_(X)<100mg/Nm^(3)的地区,可采用“SNCR+EGR”工艺,对于NO_(X)<50mg/Nm^(3)等要求更加严格的地区,仍需配合SCR工艺,达到排放要求。展开更多
文摘We investigated the sebaceous gland metaplasia(SGM) of the esophagus and clarified the evidence of misdiagnosis and its diagnosis pitfall. Cases of pathologically proven SGM were enrolled in the clinical analysis and reviewed description of endoscope. In the current study, we demonstrated that SGM is very rare esophageal condition with an incidence around 0.00465% and an occurrence rate of 0.41 per year. There were 57.1% of senior endoscopists identified 8 episodes of SGM. In contrast, 7.7% of junior endoscopists identified SGM in only 2 episodes. Moreover, we investigated the difference in endoscopic biopsy attempt rate between the senior and junior endoscopist(P = 0.0001). The senior endoscopists had more motivation to look for SGM than did junior endoscopists(P = 0.01). We concluded that SGM of the esophagus is rare condition that is easily and not recognized in endoscopy studies omitting pathological review.
文摘A concise definition of Transport Efficiency (TE) was given to examine the amount of transported grains in the pipe flow with certain energy consumption. The transport characteristics and the so-called 'roto-floating' characteristics were studied from the tests of sediment transport in the normal pipe flow and the spiral pipe flow, and hereby the energy gradients of the two kinds of pipe flows were obtained. By comparing the mean concentrations at the same gradient, it was concluded that the TE of the latter is several times to over ten times higher than that of the former, and the lift of the latter is 200 times larger than that of the former for the nearly same TE. The spiral flow in circular pipe is suitable for transporting fine grains of high concentration, and with sedimentation trend and coarse grains.
基金the National Natural Science Foundation of China(11675082,11735010)the Natural Science Foundation of Tianjin(19JCJQJC61100)。
文摘We calculate the D→P transition form factors within the framework of the light-cone QCD sum rules(LCSR)with the D-meson light-cone distribution amplitudes(LCDAs).The next-to-leading power(NLP)corrections to the vacuum-to-D-meson correlation function are considered,and the NLP corrections from the high-twist D-meson LCDAs and the SU(3)breaking effect from a strange quark mass are investigated.Adopting the exponential model of the D-meson LCDAs,the SU(3)flavor symmetry breaking effects are predicted as R+,0 SU(3)=1.12 and R T SU(3)=1.39,respectively,confirming the results obtained from LCSR with pion LCDA.The numerical predictions of the form factors show that the contribution from two-particle higher-twist contributions is of great importance and the uncertainties are dominated by the inverse moment ofϕ+D(ω,μ).With the obtained form factors,the predicted Cabibbo-Kobayashi-Maskawa(CKM)matrix elements are|Vcd|=0.151+0.091−0.043|th.+0.017−0.02|exp.and|Vcs|=0.89+0.467−0.234|th.+0.008−0.008|exp..
基金Supported in part by the National Natural Science Foundation of China(1675082,11735010)the Natural Science Foundation of Tianjin(19JCJQJC61100)。
文摘In this work,we calculate the sub-leading power contributions to radiative leptonic D→γνdecay.For the first time,we provide the analytic expressions of next-to-leading power contributions and the error estimation associated with the power expansion of O(∧_(QCD)/m_(c)).In our calculation,we adopt two different models of the D-meson distribution amplitudesφ^(+)_(D,Ⅰ)andφ^(+)_(DⅡ).Within the framework of QCD factorization as well as the dispersion relation,we evaluate the soft contribution up to the next-to-leading logarithmic accuracy and also consider the higher-twist contribution from the two-particle and three-particle distribution amplitudes.Finally,we find that all the sub-leading power contributions are significant atλd(μ0)354 MeV,and the next-to-leading power contributions lead to 143%inφ^(+)_(D,Ⅰ)and 120%inφ^(+)_(DⅡ)corrections to leading power vector form factors with Eγ=0.5 GeV.As the corrections from the higher-twist and local sub-leading power contributions are enhanced with increasing inverse moment,it is difficult to extract an appropriate inverse moment of the D-meson distribution amplitude.The predicted branching fractions are(1.88^(+0.36)_(0.29))×10^(-5)forφ^(+)_(D,Ⅰ)and(2.31^(+0.65)_(-0.54))×10^(-5)forφ^(+)_(DⅡ).
文摘为了探索适用于国内垃圾焚烧的烟气再循环(exhaust gas recirculation,EGR)技术路线,适应日益提高的NO_(X)排放要求,本文以国内某垃圾焚烧厂为例,采用CFD模拟等方法,研究了EGR系统再循环比例、取风口位置等工艺设计要点,并通过工程试验评估了EGR系统的脱硝效果及其对锅炉效率和燃烧稳定性的影响。结果表明,“SNCR+EGR”工艺能够将NO_(X)值降低至100 mg/Nm^(3)(11%O_(2)、干基)以下,且相比传统工艺焚烧线,采用EGR工艺的焚烧线吨垃圾产汽量提高3.29%。另外,EGR系统运行时,焚烧炉燃烧充分,CO浓度稳定达标。同时,炉膛温度可降低约50℃,有利于减少炉内结焦,延长耐火材料使用寿命。但是,系统运行控制要求较高且存在设备腐蚀风险。本研究为垃圾焚烧脱硝工艺的选择提供了新的方向,对于NO_(X)<100mg/Nm^(3)的地区,可采用“SNCR+EGR”工艺,对于NO_(X)<50mg/Nm^(3)等要求更加严格的地区,仍需配合SCR工艺,达到排放要求。
