Targeting the problem of large amounts of gas emission from the goaf of the No.14201 working face in the Shaqu coal mine of Huajin Coking Coal Co. Ltd., we used a negative exponential function to describe the attenuat...Targeting the problem of large amounts of gas emission from the goaf of the No.14201 working face in the Shaqu coal mine of Huajin Coking Coal Co. Ltd., we used a negative exponential function to describe the attenuation process of gas emission in goaf (the stable source) based on the principle of field flow. Equations of two-component flow (gas and air) and seep- age-diffusion in a heterogeneous goaf flow field are solved by means of numerical simulation and fluid mechanics principles of air movement and gas distribution during gas emission from goaf. The results indicate that the air diversion volume has a negative, exponential relation with the volume of gas emitted from goaf to the working face and is clearly inversely related to gas concentra- tion. We calculated the minimum amount of air diversion and distributed air volume in the tailing roadway required for safe pro- duction.展开更多
Based on the analysis of conditions for airflow reversal within a bypass branch, the airflow reversal phenomena were successfully simulated in the laboratory experiments. Data obtained indicate that airflow reversal w...Based on the analysis of conditions for airflow reversal within a bypass branch, the airflow reversal phenomena were successfully simulated in the laboratory experiments. Data obtained indicate that airflow reversal within a bypass branch is mainly caused by fire pressure yielded in the combustion branch. In addition, the maximum reversal quantity of airflow occurs in step with the highest temperature of fire, the highest concentration of CO 2 and the lowest concentration of O 2. Moreover, the time that fire size reaches the maximum value corresponds to the time airflow reversal in the bypass branch is most possible. The results are of great significance for guiding rescue work to avoid airflow reversal.展开更多
Using merged sea level anomaly and absolute geostrophic velocity products from satellite altimetry and Argos drifter data, we analyzed the reversal process of the South China Sea （SCS） westem boundary current （SCS...Using merged sea level anomaly and absolute geostrophic velocity products from satellite altimetry and Argos drifter data, we analyzed the reversal process of the South China Sea （SCS） westem boundary current （SCSwbc） from a summer to winter pattern in 2011 and important oceanic phenomena during this process. Results show that the outbreak time of the northeast monsoon over the southern SCS lagged that over the northern SCS by about 1 month. During the SCS monsoon reversal period, the SCSwbc reversed rapidly into the winter pattern at the Guangdong continental slope in late September. Subsequently, the southward Vietnam coastal boundary current strengthened. However, the northward Natuna Current maintained a summer state until mid-October. Thus, the balance between the southward and northward currents was lost when they met, their junction moved gradually southward. However, a loop current formed southeast of Vietnam because the main stream of the Vietnam Offshore Current （VOC） remained near its original latitude, Meanwhile, the VOC and associated dipole circulation system strengthened. After mid- October, the northward Natuna Current began to weaken, the loop current finally shed, becoming a cool ring. The VOC and its associated dipole sub-basin circulation system also weakened gradually until it disappeared.展开更多
Objective To investigate the regulatory mechanisms of acetylated p53 in the expression of microtubule-associated protein-2(MAP2) in neuronal differentiation of P19 cells induced by all-trans retinoic acid(RA).Methods ...Objective To investigate the regulatory mechanisms of acetylated p53 in the expression of microtubule-associated protein-2(MAP2) in neuronal differentiation of P19 cells induced by all-trans retinoic acid(RA).Methods Neuronal differentiation of P19 cells was initiated with 4-day RA treatment.Immunofluorescence,real-time reverse transcription-polymerase chain reaction(RT-PCR) assay,and map2 promoter driven luciferase assay were performed to detect the expression and relative promoter activity of MAP2 in those RA-treated cells.Real-time PCR-based chromatin immunoprecipitation assay(ChIP) was carried out to reveal the specific recruitment of acetylated p53 onto its binding sites on map2 promoter.Results The expression of MAP2 was markedly increased in RA-induced P19 cells.The map2 mRNA increased 34-fold after 4 days of RA treatment and 730-fold 2 days after the treatment,compared with the cells without RA treatment(control).p53 was recruited to the promoter of map2 gene in acetylated form and thereby enhanced its promoter activity.p300/CBP associated factor(PCAF) was found induced in RA-treated cells and enriched in the nucleus,which might contribute to the acetylation of p53 in the regulation of map2 gene.Conclusions Acetylated p53 may participate in regulating the expression of map2 in RA-induced differentiation of P19 cells.PCAF is possibly involved in this process by mediating the acetylation of p53.展开更多
Nowadays,the upwind schemes are in a rapid development to capture shock accurately.However,these upwind schemes’properties at low speeds,such as their reconstruction scheme dependencies,grid dependencies,and Mach num...Nowadays,the upwind schemes are in a rapid development to capture shock accurately.However,these upwind schemes’properties at low speeds,such as their reconstruction scheme dependencies,grid dependencies,and Mach number dependencies,are concerned by few people.In this paper,a systematic study on their low speeds’issues is conducted.Through a series of tests,we can find that most parameter-free upwind schemes,widely used in practice today,are not applicable to low speeds’simulations.In contrast,SLAU and SLAU2 can give reliable results.Also,the upwind scheme’s influence on the accuracy is stronger than the reconstruction scheme’s influence at low speeds.展开更多
基金Project 50574038 supported by the National Natural Science Foundation of China
文摘Targeting the problem of large amounts of gas emission from the goaf of the No.14201 working face in the Shaqu coal mine of Huajin Coking Coal Co. Ltd., we used a negative exponential function to describe the attenuation process of gas emission in goaf (the stable source) based on the principle of field flow. Equations of two-component flow (gas and air) and seep- age-diffusion in a heterogeneous goaf flow field are solved by means of numerical simulation and fluid mechanics principles of air movement and gas distribution during gas emission from goaf. The results indicate that the air diversion volume has a negative, exponential relation with the volume of gas emitted from goaf to the working face and is clearly inversely related to gas concentra- tion. We calculated the minimum amount of air diversion and distributed air volume in the tailing roadway required for safe pro- duction.
基金National Natural Science Foundation of China( 5 9876 0 45 )
文摘Based on the analysis of conditions for airflow reversal within a bypass branch, the airflow reversal phenomena were successfully simulated in the laboratory experiments. Data obtained indicate that airflow reversal within a bypass branch is mainly caused by fire pressure yielded in the combustion branch. In addition, the maximum reversal quantity of airflow occurs in step with the highest temperature of fire, the highest concentration of CO 2 and the lowest concentration of O 2. Moreover, the time that fire size reaches the maximum value corresponds to the time airflow reversal in the bypass branch is most possible. The results are of great significance for guiding rescue work to avoid airflow reversal.
基金Supported by the UNESCO-IOC/WESTPAC Project"Response of marine hazards to climate change in the Western Pacific"the Special Fund of Chinese Central Government for Basic Scientific Research Operations in Commonweal Research Institutes(No.GY0212172)+1 种基金the Open Foundation of the Key Laboratory of Data Analysis and ApplicationsState Oceanic Administration(No.LDAA-2012-02)
文摘Using merged sea level anomaly and absolute geostrophic velocity products from satellite altimetry and Argos drifter data, we analyzed the reversal process of the South China Sea （SCS） westem boundary current （SCSwbc） from a summer to winter pattern in 2011 and important oceanic phenomena during this process. Results show that the outbreak time of the northeast monsoon over the southern SCS lagged that over the northern SCS by about 1 month. During the SCS monsoon reversal period, the SCSwbc reversed rapidly into the winter pattern at the Guangdong continental slope in late September. Subsequently, the southward Vietnam coastal boundary current strengthened. However, the northward Natuna Current maintained a summer state until mid-October. Thus, the balance between the southward and northward currents was lost when they met, their junction moved gradually southward. However, a loop current formed southeast of Vietnam because the main stream of the Vietnam Offshore Current （VOC） remained near its original latitude, Meanwhile, the VOC and associated dipole circulation system strengthened. After mid- October, the northward Natuna Current began to weaken, the loop current finally shed, becoming a cool ring. The VOC and its associated dipole sub-basin circulation system also weakened gradually until it disappeared.
基金Supported by National Natural Science Foundation of China (30871382,30721063)National Basic Research Program of China (973 Program) (2005CB522405)Special Funds of State Key Laboratories (2060204)
文摘Objective To investigate the regulatory mechanisms of acetylated p53 in the expression of microtubule-associated protein-2(MAP2) in neuronal differentiation of P19 cells induced by all-trans retinoic acid(RA).Methods Neuronal differentiation of P19 cells was initiated with 4-day RA treatment.Immunofluorescence,real-time reverse transcription-polymerase chain reaction(RT-PCR) assay,and map2 promoter driven luciferase assay were performed to detect the expression and relative promoter activity of MAP2 in those RA-treated cells.Real-time PCR-based chromatin immunoprecipitation assay(ChIP) was carried out to reveal the specific recruitment of acetylated p53 onto its binding sites on map2 promoter.Results The expression of MAP2 was markedly increased in RA-induced P19 cells.The map2 mRNA increased 34-fold after 4 days of RA treatment and 730-fold 2 days after the treatment,compared with the cells without RA treatment(control).p53 was recruited to the promoter of map2 gene in acetylated form and thereby enhanced its promoter activity.p300/CBP associated factor(PCAF) was found induced in RA-treated cells and enriched in the nucleus,which might contribute to the acetylation of p53 in the regulation of map2 gene.Conclusions Acetylated p53 may participate in regulating the expression of map2 in RA-induced differentiation of P19 cells.PCAF is possibly involved in this process by mediating the acetylation of p53.
基金supported by the National Basic Research Program of China("973" Project)(Grant No.2009CB724104)
文摘Nowadays,the upwind schemes are in a rapid development to capture shock accurately.However,these upwind schemes’properties at low speeds,such as their reconstruction scheme dependencies,grid dependencies,and Mach number dependencies,are concerned by few people.In this paper,a systematic study on their low speeds’issues is conducted.Through a series of tests,we can find that most parameter-free upwind schemes,widely used in practice today,are not applicable to low speeds’simulations.In contrast,SLAU and SLAU2 can give reliable results.Also,the upwind scheme’s influence on the accuracy is stronger than the reconstruction scheme’s influence at low speeds.
