The source rock sample of the Shahejie Formation （upper Es4） in Jiyang Sag was pyrolyzed under open system with the Rock-Eval-lI apparatus, and then kinetic model parameters were calibrated for investigating the eff...The source rock sample of the Shahejie Formation （upper Es4） in Jiyang Sag was pyrolyzed under open system with the Rock-Eval-lI apparatus, and then kinetic model parameters were calibrated for investigating the effect of uncertainty of pre-exponential factors on kinetic parameters and geological applications, where the parallel first-order reaction rate model with an average pre- exponential factor and discrete distribution activity energies was used. The results indicate that when the pre-exponential factor changes from low to high, an extreme value for residual errors occurs. And with the increasing pre-exponential factor, the distribution shape of activation energies are nearly the same, but the values of activation energies move higher integrally, and the average activation energy increases about 12 kJ/mol for every 10-fold of the pre-exponential factors. Extrapolating the geological heating rate of 3.3 ~C/Ma, the results show that with the increases in pre-exponential factor, the geological temperature corresponding to TRo.5 （transforming ratio of hydrocarbon generation is 50%） increases gradually, and the additional temperature gradually decreases. Combined with geochemical data of source rock, the kinetic parameters with different pre-exponentia[ factors are used to calculate the transformation ratio of hydrocarbon generation, and the result indicates that kinetic parameters corresponding to the better optimized pre-exponential factor are more suitable. It is suggested that the risk assessment of hydrocarbon generation kinetic parameters should be enhanced when using the kinetic method to appraise the oil-gas resources. Meantime, the application result of different kinetic parameters should be verified with geological and geochemical data of source rock in the target area; therefore, the most suitable kinetic parameters for target can be obtained.展开更多
Although the slippage effect has been extensively studied,most of the previous studies focused on the impact of the slippage effect on apparent permeability within a low pore pressure range,resulting in the inability ...Although the slippage effect has been extensively studied,most of the previous studies focused on the impact of the slippage effect on apparent permeability within a low pore pressure range,resulting in the inability of matching the evolution of permeability in the remaining pressure range.In this paper,a new apparent permeability model that reveals the evolution of permeability under the combined action of effective stress and slippage in the full pore pressure range was proposed.In this model,both intrinsic permeability and slippage coefficient are stress dependent.Three experimental tests with pore pressure lower than 2 MPa and a test with pore pressure at about 10 MPa using cores from the same origin under constant confining stress and constant effective stress are conducted.By comparing experimental data and another apparent permeability model,we proved the fidelity of our newly developed model.Furthermore,the contribution factor of the slippage effect Rslip is used to determine the low pore pressure limit with significant slippage effect.Our results show that both narrow initial pore size and high effective stress increase the critical pore pressure.Finally,the evolutions of the slippage coefficient and the intrinsic permeability under different boundary conditions were analyzed.展开更多
Correlations among free radicals, apparent activation energy, and functional groups during lowtemperature oxidation of Jurassic coal in Northern Shaanxi were investigated by examining three coal samples collected from...Correlations among free radicals, apparent activation energy, and functional groups during lowtemperature oxidation of Jurassic coal in Northern Shaanxi were investigated by examining three coal samples collected from the Ningtiaota, Jianxin, and Shigetai coal mines. Free radical concentrations at less than 120 ℃ were investigated by electron spin resonance experiments while the thermogravimetric experiments were conducted to analyze apparent activation energies. In addition, Fourier transform infrared spectroscopy was employed to study the spectrum of functional groups generated in coal. The results indicated that, in decreasing order, the apparent activation energies were Shigetai 〉Jianxin 〉 Ningtiaota, indicating that, from 50 to 120 ℃, the Ningtiaota coal sample most easily absorbed and reacted with oxygen while the most resistant was the Shigetai coal sample. Free radical concentrations and line heights increased with increased temperature, and the line width and Lande factor showed irregular fluctuations. Functional group variations were different among these coals, and the phenol and alcohol-associated OHs, carboxyls, and aromatic ring double bonds might have had a major impact on free radical concentrations. These results were meaningful for better consideration and management of coal oxidation at low temperatures.展开更多
To analyze how the multidisciplinary clinical, biohumoral, instrumental approach to ALTE (Apparent Life Threatening Event) episode may discover cardiovascular disease in the newborn. Introduction: In the first year of...To analyze how the multidisciplinary clinical, biohumoral, instrumental approach to ALTE (Apparent Life Threatening Event) episode may discover cardiovascular disease in the newborn. Introduction: In the first year of life ALTEs concern 0.8% of access to Pediatric Emergency Department. The cause of apparent life-threatening events (ALTEs) in infants reflects a differential diagnosis that includes an array of congenital or acquired disorders. Approximately 10% - 25% of ap-parent life-threatening events may remain unexplained following a thorough evaluation. Case re-port: B. E., a 2-month-old child, in wellbeing, shortly before meal, during sleep, was not responsive to repeated stimulations;he was hypotonic and unresponsive. About 15 minutes later, he pre-sented a normal tone and state of consciousness. Evaluating the referred symptoms, diagnostic protocol for ALTE was started;the Angio-MRI brain performed as second line analysis showed a focal gliotic lesion at left striatal area. The cardiological evaluation with echocardiography detected a pervium foramen ovale (PFO), with minimum shunt left-right direction. At least, biohumoral tests revealed protrombin gene heterozygosis mutation. Conclusion: Apparent Life-Threatening Events are first manifestation of stroke in infant. Discussion: This report discloses how the multidisciplinary clinical approach is essential in ALTE. The exact management of ALTE patients is very important in situations like this, when the concomitant disease is rare. In fact, arterial stroke incidence in children > 28 days of life is estimated between 1.2 and 7.9 cases/100,000 child-ren/year. However, in the last 20 years, we observed an increased incidence of stroke, probably related to two main causes: a greater attention for this disease and a major survival of children with pathology that arrange for stroke thanks to a better prevention. In conclusion, it’s a fundamental multidisciplinary approach even in following months after the events.展开更多
Power factor (PF) is simply an expression of energy efficiency, which is always expressed in terms of percentage. Technically, PF is a ratio of real power in Kilowatts to the apparent power, which is always expressed ...Power factor (PF) is simply an expression of energy efficiency, which is always expressed in terms of percentage. Technically, PF is a ratio of real power in Kilowatts to the apparent power, which is always expressed in kilovolts amperes. In AC power analysis, power is always expressed in three ways, the real power (<i></span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;"></i>), reactive power (<i></span><i><span style="font-family:Verdana;">Q</span></i><span style="font-family:Verdana;"></i>), and the apparent power (<i></span><i><span style="font-family:Verdana;">S</span></i><span style="font-family:Verdana;"></i>). The real power is the work useful power, while the reactive power is the wasted power in the 3-phase AC system, and the apparent power is the vectorial sum of the two powers. The increase of reactive power will reduce the presence of real power, thus making the power to be more expensive. In this paper, we will analyze the importance of improving the power factor by applying a bank of capacitors to a case study in Lebanon. Analysis of the economic improvement in the application of power factor correction is carried out. The result shows a reduction of 12 percent in the total cost.展开更多
目的探讨并比较单指数模型、双指数模型、拉伸指数模型定量参数对乳腺癌HER2阳性状态的预测价值。方法回顾性分析67例确诊为浸润性乳腺癌患者的影像及临床资料。在病灶表观扩散系数(ADC)图像勾画感兴趣区(ROI),并对照扩散加权成像(DWI)...目的探讨并比较单指数模型、双指数模型、拉伸指数模型定量参数对乳腺癌HER2阳性状态的预测价值。方法回顾性分析67例确诊为浸润性乳腺癌患者的影像及临床资料。在病灶表观扩散系数(ADC)图像勾画感兴趣区(ROI),并对照扩散加权成像(DWI)图像修正ROI,记录病灶的表观扩散系数(ADC)、伪扩散系数(ADC_(fast))、真实扩散系数(ADC_(slow))、灌注分数(ADC_(fraction of fast))、分布扩散系数(DDC)、扩散异质性值(α)。根据免疫组化结果,将患者分为两组(HER2阳性vs.HER2阴性)。采用单因素分析比较两组间三种指数模型的六项定量参数(ADC、ADC_(fast)、ADC_(slow)、ADC_(fraction of fast)、DDC、α)组间差异。将具有统计学差异的定量参数纳入二元Logistic回归分析,并构建联合预测模型。采用DeLong检验比较三种模型定量参数、联合模型的受试者工作特征(ROC)曲线下面积(AUC),区分诊断效能。结果HER2阳性组ADC_(fast)值高于HER2阴性组(P<0.05),ADC、ADC_(slow)、DDC值低于HER2阴性组(均P<0.05)。ADC、ADC_(fast)、ADC_(slow)、DDC、ADC_(fast)-ADC_(slow)联合模型的AUC分别为75.85%、71.11%、76.92%、71.11%、88.19%;ADC_(fast)-ADC_(slow)联合模型的AUC最高,诊断效能显著优于ADC_(fast)(P=0.009),与ADC、ADC_(slow)、DDC相仿(均P>0.05);ADC、ADC_(fast)、ADC_(slow)、DDC的诊断效能组间比较表现相仿(均P>0.05)。结论三种不同指数模型定量参数有助于预测乳腺癌HER2阳性状态;双指数模型参数联合模型预测效能最优。展开更多
Replacing solid carbon with hydrogen gas in ferromanganese production presents a forward-thinking,sustainable solution to re-ducing the ferro-alloy industry’s carbon emissions.The HAlMan process,a groundbreaking and ...Replacing solid carbon with hydrogen gas in ferromanganese production presents a forward-thinking,sustainable solution to re-ducing the ferro-alloy industry’s carbon emissions.The HAlMan process,a groundbreaking and eco-friendly method,has been meticu-lously researched and scaled up from laboratory experiments to pilot tests,aiming to drastically cut CO_(2) emissions associated with ferro-manganese production.This innovative process could potentially reduce CO_(2) emissions by about 1.5 tonnes for every tonne of ferroman-ganese produced.In this study,a lab-scale vertical thermogravimetric furnace was used to carry out the pre-reduction of Nchwaning man-ganese ore,where direct reduction occurred with H_(2) gas under controlled isothermal conditions at 700,800,and 900℃.The results indic-ated that higher pre-reduction temperatures(800 and 900℃)effectively converted Fe_(2)O_(3) to metallic iron and Mn_(2)O_(3) to MnO.By continu-ously monitoring the mass changes during the reduction,both the rate and extent of reduction were assessed.A second-order reaction model was applied to validate the experimental outcomes of H_(2) reduction at various temperatures,showing apparent activation energies of 29.79 kJ/mol for dried ore and 61.71 kJ/mol for pre-calcined ore.The reduction kinetics displayed a strong dependence on temperature,with higher temperatures leading to quicker and more complete reductions.The kinetics analysis suggested that the chemical reaction at the gas-solid interface between hydrogen and the manganese ore is likely the rate-limiting step in this process.展开更多
The thermal decomposition kinetics of high iron gibbsite ore was investigated under non-isothermal conditions.Popescu method was applied to analyzing the thermal decomposition mechanism.The results show that the most ...The thermal decomposition kinetics of high iron gibbsite ore was investigated under non-isothermal conditions.Popescu method was applied to analyzing the thermal decomposition mechanism.The results show that the most probable thermal decomposition mechanism is the three-dimensional diffusion model of Jander equation,and the mechanism code is D3.The activation energy and pre-exponential factor for thermal decomposition of high iron gibbsite ore calculated by the Popescu method are 75.36 kJ/mol and 1.51×10-5 s-（-1）,respectively.The correctness of the obtained mechanism function is validated by the activation energy acquired by the iso-conversional method.Popescu method is a rational and reliable method for the analysis of the thermal decomposition mechanism of high iron gibbsite ore.展开更多
基金supported by grants from the Natural Science Foundation of China(40972101)the National Key Basic Research and Development Program(2009CB219306)CNPC Innovation Foundation(2011D-5006-0101)
文摘The source rock sample of the Shahejie Formation （upper Es4） in Jiyang Sag was pyrolyzed under open system with the Rock-Eval-lI apparatus, and then kinetic model parameters were calibrated for investigating the effect of uncertainty of pre-exponential factors on kinetic parameters and geological applications, where the parallel first-order reaction rate model with an average pre- exponential factor and discrete distribution activity energies was used. The results indicate that when the pre-exponential factor changes from low to high, an extreme value for residual errors occurs. And with the increasing pre-exponential factor, the distribution shape of activation energies are nearly the same, but the values of activation energies move higher integrally, and the average activation energy increases about 12 kJ/mol for every 10-fold of the pre-exponential factors. Extrapolating the geological heating rate of 3.3 ~C/Ma, the results show that with the increases in pre-exponential factor, the geological temperature corresponding to TRo.5 （transforming ratio of hydrocarbon generation is 50%） increases gradually, and the additional temperature gradually decreases. Combined with geochemical data of source rock, the kinetic parameters with different pre-exponentia[ factors are used to calculate the transformation ratio of hydrocarbon generation, and the result indicates that kinetic parameters corresponding to the better optimized pre-exponential factor are more suitable. It is suggested that the risk assessment of hydrocarbon generation kinetic parameters should be enhanced when using the kinetic method to appraise the oil-gas resources. Meantime, the application result of different kinetic parameters should be verified with geological and geochemical data of source rock in the target area; therefore, the most suitable kinetic parameters for target can be obtained.
基金supported by the National Natural Science Foundation of China(No.52079077)the Natural Science Foundation of Shandong Province(No.ZR2021QE069)China Postdoctoral Science Foundation(No.2019M662402).
文摘Although the slippage effect has been extensively studied,most of the previous studies focused on the impact of the slippage effect on apparent permeability within a low pore pressure range,resulting in the inability of matching the evolution of permeability in the remaining pressure range.In this paper,a new apparent permeability model that reveals the evolution of permeability under the combined action of effective stress and slippage in the full pore pressure range was proposed.In this model,both intrinsic permeability and slippage coefficient are stress dependent.Three experimental tests with pore pressure lower than 2 MPa and a test with pore pressure at about 10 MPa using cores from the same origin under constant confining stress and constant effective stress are conducted.By comparing experimental data and another apparent permeability model,we proved the fidelity of our newly developed model.Furthermore,the contribution factor of the slippage effect Rslip is used to determine the low pore pressure limit with significant slippage effect.Our results show that both narrow initial pore size and high effective stress increase the critical pore pressure.Finally,the evolutions of the slippage coefficient and the intrinsic permeability under different boundary conditions were analyzed.
基金supported by the Key Projects of the National Natural Science Foundation of China (Nos. 51504187, 51774233, and 51704226)Shaanxi Province Industrial Science and Technology Research Project (No. 2016GY-192)the China Postdoctoral Science Foundation (No. 2016-M-590963)
文摘Correlations among free radicals, apparent activation energy, and functional groups during lowtemperature oxidation of Jurassic coal in Northern Shaanxi were investigated by examining three coal samples collected from the Ningtiaota, Jianxin, and Shigetai coal mines. Free radical concentrations at less than 120 ℃ were investigated by electron spin resonance experiments while the thermogravimetric experiments were conducted to analyze apparent activation energies. In addition, Fourier transform infrared spectroscopy was employed to study the spectrum of functional groups generated in coal. The results indicated that, in decreasing order, the apparent activation energies were Shigetai 〉Jianxin 〉 Ningtiaota, indicating that, from 50 to 120 ℃, the Ningtiaota coal sample most easily absorbed and reacted with oxygen while the most resistant was the Shigetai coal sample. Free radical concentrations and line heights increased with increased temperature, and the line width and Lande factor showed irregular fluctuations. Functional group variations were different among these coals, and the phenol and alcohol-associated OHs, carboxyls, and aromatic ring double bonds might have had a major impact on free radical concentrations. These results were meaningful for better consideration and management of coal oxidation at low temperatures.
文摘To analyze how the multidisciplinary clinical, biohumoral, instrumental approach to ALTE (Apparent Life Threatening Event) episode may discover cardiovascular disease in the newborn. Introduction: In the first year of life ALTEs concern 0.8% of access to Pediatric Emergency Department. The cause of apparent life-threatening events (ALTEs) in infants reflects a differential diagnosis that includes an array of congenital or acquired disorders. Approximately 10% - 25% of ap-parent life-threatening events may remain unexplained following a thorough evaluation. Case re-port: B. E., a 2-month-old child, in wellbeing, shortly before meal, during sleep, was not responsive to repeated stimulations;he was hypotonic and unresponsive. About 15 minutes later, he pre-sented a normal tone and state of consciousness. Evaluating the referred symptoms, diagnostic protocol for ALTE was started;the Angio-MRI brain performed as second line analysis showed a focal gliotic lesion at left striatal area. The cardiological evaluation with echocardiography detected a pervium foramen ovale (PFO), with minimum shunt left-right direction. At least, biohumoral tests revealed protrombin gene heterozygosis mutation. Conclusion: Apparent Life-Threatening Events are first manifestation of stroke in infant. Discussion: This report discloses how the multidisciplinary clinical approach is essential in ALTE. The exact management of ALTE patients is very important in situations like this, when the concomitant disease is rare. In fact, arterial stroke incidence in children > 28 days of life is estimated between 1.2 and 7.9 cases/100,000 child-ren/year. However, in the last 20 years, we observed an increased incidence of stroke, probably related to two main causes: a greater attention for this disease and a major survival of children with pathology that arrange for stroke thanks to a better prevention. In conclusion, it’s a fundamental multidisciplinary approach even in following months after the events.
文摘Power factor (PF) is simply an expression of energy efficiency, which is always expressed in terms of percentage. Technically, PF is a ratio of real power in Kilowatts to the apparent power, which is always expressed in kilovolts amperes. In AC power analysis, power is always expressed in three ways, the real power (<i></span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;"></i>), reactive power (<i></span><i><span style="font-family:Verdana;">Q</span></i><span style="font-family:Verdana;"></i>), and the apparent power (<i></span><i><span style="font-family:Verdana;">S</span></i><span style="font-family:Verdana;"></i>). The real power is the work useful power, while the reactive power is the wasted power in the 3-phase AC system, and the apparent power is the vectorial sum of the two powers. The increase of reactive power will reduce the presence of real power, thus making the power to be more expensive. In this paper, we will analyze the importance of improving the power factor by applying a bank of capacitors to a case study in Lebanon. Analysis of the economic improvement in the application of power factor correction is carried out. The result shows a reduction of 12 percent in the total cost.
文摘目的探讨并比较单指数模型、双指数模型、拉伸指数模型定量参数对乳腺癌HER2阳性状态的预测价值。方法回顾性分析67例确诊为浸润性乳腺癌患者的影像及临床资料。在病灶表观扩散系数(ADC)图像勾画感兴趣区(ROI),并对照扩散加权成像(DWI)图像修正ROI,记录病灶的表观扩散系数(ADC)、伪扩散系数(ADC_(fast))、真实扩散系数(ADC_(slow))、灌注分数(ADC_(fraction of fast))、分布扩散系数(DDC)、扩散异质性值(α)。根据免疫组化结果,将患者分为两组(HER2阳性vs.HER2阴性)。采用单因素分析比较两组间三种指数模型的六项定量参数(ADC、ADC_(fast)、ADC_(slow)、ADC_(fraction of fast)、DDC、α)组间差异。将具有统计学差异的定量参数纳入二元Logistic回归分析,并构建联合预测模型。采用DeLong检验比较三种模型定量参数、联合模型的受试者工作特征(ROC)曲线下面积(AUC),区分诊断效能。结果HER2阳性组ADC_(fast)值高于HER2阴性组(P<0.05),ADC、ADC_(slow)、DDC值低于HER2阴性组(均P<0.05)。ADC、ADC_(fast)、ADC_(slow)、DDC、ADC_(fast)-ADC_(slow)联合模型的AUC分别为75.85%、71.11%、76.92%、71.11%、88.19%;ADC_(fast)-ADC_(slow)联合模型的AUC最高,诊断效能显著优于ADC_(fast)(P=0.009),与ADC、ADC_(slow)、DDC相仿(均P>0.05);ADC、ADC_(fast)、ADC_(slow)、DDC的诊断效能组间比较表现相仿(均P>0.05)。结论三种不同指数模型定量参数有助于预测乳腺癌HER2阳性状态;双指数模型参数联合模型预测效能最优。
基金the financial support from European Union’s Horizon Europe program HAlMan project (No. 101091936)
文摘Replacing solid carbon with hydrogen gas in ferromanganese production presents a forward-thinking,sustainable solution to re-ducing the ferro-alloy industry’s carbon emissions.The HAlMan process,a groundbreaking and eco-friendly method,has been meticu-lously researched and scaled up from laboratory experiments to pilot tests,aiming to drastically cut CO_(2) emissions associated with ferro-manganese production.This innovative process could potentially reduce CO_(2) emissions by about 1.5 tonnes for every tonne of ferroman-ganese produced.In this study,a lab-scale vertical thermogravimetric furnace was used to carry out the pre-reduction of Nchwaning man-ganese ore,where direct reduction occurred with H_(2) gas under controlled isothermal conditions at 700,800,and 900℃.The results indic-ated that higher pre-reduction temperatures(800 and 900℃)effectively converted Fe_(2)O_(3) to metallic iron and Mn_(2)O_(3) to MnO.By continu-ously monitoring the mass changes during the reduction,both the rate and extent of reduction were assessed.A second-order reaction model was applied to validate the experimental outcomes of H_(2) reduction at various temperatures,showing apparent activation energies of 29.79 kJ/mol for dried ore and 61.71 kJ/mol for pre-calcined ore.The reduction kinetics displayed a strong dependence on temperature,with higher temperatures leading to quicker and more complete reductions.The kinetics analysis suggested that the chemical reaction at the gas-solid interface between hydrogen and the manganese ore is likely the rate-limiting step in this process.
基金Project(51374058)supported by the National Natural Science Foundation of China
文摘The thermal decomposition kinetics of high iron gibbsite ore was investigated under non-isothermal conditions.Popescu method was applied to analyzing the thermal decomposition mechanism.The results show that the most probable thermal decomposition mechanism is the three-dimensional diffusion model of Jander equation,and the mechanism code is D3.The activation energy and pre-exponential factor for thermal decomposition of high iron gibbsite ore calculated by the Popescu method are 75.36 kJ/mol and 1.51×10-5 s-（-1）,respectively.The correctness of the obtained mechanism function is validated by the activation energy acquired by the iso-conversional method.Popescu method is a rational and reliable method for the analysis of the thermal decomposition mechanism of high iron gibbsite ore.
