Using the complex variable method,an elastic analytical solution of the ground displacement caused by a shallow circular tunneling is derived.Non-symmetric deformation relative to the horizontal center line of the tun...Using the complex variable method,an elastic analytical solution of the ground displacement caused by a shallow circular tunneling is derived.Non-symmetric deformation relative to the horizontal center line of the tunnel cross-section is used as a boundary condition.A comparison between the proposed analytical method and the Finite Element Method is carried out to validate the rationality of the obtained analytical solution.Two parameters in the Peck formula,namely the maximum settlement of the ground surface center and the width coefficient of settlement curve,are fitted and determined.We propose a modified Peck formula by considering three input parameters,namely the tunnel depth,tunnel radius,and the tunnel gap.The influence of these three parameters on the modified Peck formula is analyzed.The applicability of the modified Peck formula is further investigated by reference to six engineering projects.The ground surface displacement obtained by the explicit Peck formula is in good agreement with the field data,and the maximum error is only 1.3 cm.The proposed formula can quickly and reasonably predict the ground surface settlement caused by tunnelling.展开更多
Morchella angusticeps Peck,one of the most popular edible mushrooms,has attracted great attention due to its delicious taste and healthy properties.However,both its biological effects and the possible mechanism of act...Morchella angusticeps Peck,one of the most popular edible mushrooms,has attracted great attention due to its delicious taste and healthy properties.However,both its biological effects and the possible mechanism of action have not yet been known.We investigated the anti-proliferative activity of the phenolic extract derived from Morchella angusticeps Peck(MPE)against HepG2 human hepatocellular carcinoma cells.Results showed that MPE at non-cytotoxicity doses significantly inhibited the proliferation of HepG2 cells in a dose-dependent manner with inhibitory rates ranging from 18 to 90%(P<0.01).The possible mechanism might be that MPE induced apoptosis through initiating the mitochondrial death pathway by regulating Bax,Bcl-2 and cleaved caspase-3.On the other hand,MPE might trigger cell cycle arrest at G0/G1/S phases by managing p21,Cyclin D1,cyclin-dependent kinases-4(CDK4)and proliferating cell nuclear antigen(PCNA).Additionally,MPE downregulated TRAF-2 and p-p53,while upregulated p-ASK1 and p-p38.Therefore,it could be inferred that MPE might induce the anti-proliferative function to HepG2 cells through the p38/MAPK signal transduction pathway.展开更多
Based on database of ecological factors and geographic information space analysis method, we analyzed suitability of Wolfiporia extensa (Peck) Ginns producing regions, in the hope of providing reference for scientific...Based on database of ecological factors and geographic information space analysis method, we analyzed suitability of Wolfiporia extensa (Peck) Ginns producing regions, in the hope of providing reference for scientific zoning and cultivation. Ecological factors we analyzed mainly include temperature, altitude, and soil. Our analysis shows that Hubei, Anhui, Yunnan, Guizhou and Sichuan provinces are regions that have highest similarity with original producing areas of Wolfiporia extensa (Peck) Ginns. This is basically consistent with actual conditions. In addition, we predicted some regions (for example, Gansu) that have not been recorded in literature, which provides scientific and reliable data support for seed introduction and expansion of Wolfiporia extensa (Peck) Ginns. Using the GIS-based program for the distribution prediction of traditional Chinese medicine (TCMGIS-II) to analyze suitability of Wolfiporia extensa (Peck) Ginns producing regions is scientific and accurate, and will provide important reference for seed introduction, cultivation and scientific zoning of Wolfiporia extensa (Peck) Ginns.展开更多
In this study,experimental and numerical investigations are performed to clarify the seepage failure by heave in sheeted excavation pits in stratified cohesionless soils in which a relatively permeable soil layer(Kupp...In this study,experimental and numerical investigations are performed to clarify the seepage failure by heave in sheeted excavation pits in stratified cohesionless soils in which a relatively permeable soil layer(Kupper)lies above a less permeable soil layer(Klower)between excavation base and wall tip.It is shown that the evaluation of base stabilities of excavation pits against seepage failure by using Terzaghi and Peck's approach leads to considerably lower critical potential differences than those obtained from the model tests.On the other hand,a relatively good agreement is achieved between the results of the model tests and the finite element(FE)analyses.Further investigations are performed by using axisymmetric excavation models with various dimensions and ground conditions,and a comparison between the results obtained from Terzaghi and Peck's approach and finite element analyses is given.展开更多
基金National Natural Science Foundation of China(Grant Nos.52025084 and 52208396)China Postdoctoral Science Foundation(No.2021M701934).
文摘Using the complex variable method,an elastic analytical solution of the ground displacement caused by a shallow circular tunneling is derived.Non-symmetric deformation relative to the horizontal center line of the tunnel cross-section is used as a boundary condition.A comparison between the proposed analytical method and the Finite Element Method is carried out to validate the rationality of the obtained analytical solution.Two parameters in the Peck formula,namely the maximum settlement of the ground surface center and the width coefficient of settlement curve,are fitted and determined.We propose a modified Peck formula by considering three input parameters,namely the tunnel depth,tunnel radius,and the tunnel gap.The influence of these three parameters on the modified Peck formula is analyzed.The applicability of the modified Peck formula is further investigated by reference to six engineering projects.The ground surface displacement obtained by the explicit Peck formula is in good agreement with the field data,and the maximum error is only 1.3 cm.The proposed formula can quickly and reasonably predict the ground surface settlement caused by tunnelling.
基金This research was supported by the National Natural Science Foundation of China(31471576,31271825)the Fundamental Research Funds for the Central Universities,China(XDJK2018B030,SWU118012).
文摘Morchella angusticeps Peck,one of the most popular edible mushrooms,has attracted great attention due to its delicious taste and healthy properties.However,both its biological effects and the possible mechanism of action have not yet been known.We investigated the anti-proliferative activity of the phenolic extract derived from Morchella angusticeps Peck(MPE)against HepG2 human hepatocellular carcinoma cells.Results showed that MPE at non-cytotoxicity doses significantly inhibited the proliferation of HepG2 cells in a dose-dependent manner with inhibitory rates ranging from 18 to 90%(P<0.01).The possible mechanism might be that MPE induced apoptosis through initiating the mitochondrial death pathway by regulating Bax,Bcl-2 and cleaved caspase-3.On the other hand,MPE might trigger cell cycle arrest at G0/G1/S phases by managing p21,Cyclin D1,cyclin-dependent kinases-4(CDK4)and proliferating cell nuclear antigen(PCNA).Additionally,MPE downregulated TRAF-2 and p-p53,while upregulated p-ASK1 and p-p38.Therefore,it could be inferred that MPE might induce the anti-proliferative function to HepG2 cells through the p38/MAPK signal transduction pathway.
基金Supported by Significant New Medicine Formulation in the Eleventh Five-Year Plan Period(2009ZX09504-004)Key National Natural Scient Foundation of China(81130069)(81274013)
文摘Based on database of ecological factors and geographic information space analysis method, we analyzed suitability of Wolfiporia extensa (Peck) Ginns producing regions, in the hope of providing reference for scientific zoning and cultivation. Ecological factors we analyzed mainly include temperature, altitude, and soil. Our analysis shows that Hubei, Anhui, Yunnan, Guizhou and Sichuan provinces are regions that have highest similarity with original producing areas of Wolfiporia extensa (Peck) Ginns. This is basically consistent with actual conditions. In addition, we predicted some regions (for example, Gansu) that have not been recorded in literature, which provides scientific and reliable data support for seed introduction and expansion of Wolfiporia extensa (Peck) Ginns. Using the GIS-based program for the distribution prediction of traditional Chinese medicine (TCMGIS-II) to analyze suitability of Wolfiporia extensa (Peck) Ginns producing regions is scientific and accurate, and will provide important reference for seed introduction, cultivation and scientific zoning of Wolfiporia extensa (Peck) Ginns.
文摘In this study,experimental and numerical investigations are performed to clarify the seepage failure by heave in sheeted excavation pits in stratified cohesionless soils in which a relatively permeable soil layer(Kupper)lies above a less permeable soil layer(Klower)between excavation base and wall tip.It is shown that the evaluation of base stabilities of excavation pits against seepage failure by using Terzaghi and Peck's approach leads to considerably lower critical potential differences than those obtained from the model tests.On the other hand,a relatively good agreement is achieved between the results of the model tests and the finite element(FE)analyses.Further investigations are performed by using axisymmetric excavation models with various dimensions and ground conditions,and a comparison between the results obtained from Terzaghi and Peck's approach and finite element analyses is given.
