Given the background of a transmission tower erected on a particular mining subsidence area,we used finite element modeling to analyze the anti-deformation performance of transmission towers under a number of differen...Given the background of a transmission tower erected on a particular mining subsidence area,we used finite element modeling to analyze the anti-deformation performance of transmission towers under a number of different load conditions,including horizontal foundation displacement,uneven vertical downward displacement,wind loads and icing conditions.The results show that the failure in stability of a single steel angle iron represents the limit of the tower given ground deformation.We calculated the corresponding limits of foundation displacements.The results indicate that compression displacement of the foundation is more dangerous than tension displacement.Under complex foundation displacement conditions,horizontal foundation displacement is a key factor leading to failure in the stability of towers.Under conditions of compression or tension displacement of the foundation,wind load becomes the key factor.Towers do not fail when foundation displacements are smaller than 1% (under tension) or 0.5% (under horizontal compression or single foundation subsidence) of the distance between two supports.展开更多
Objective: To investigate anti-tumor effect of bufalin on the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice. Methods: BEL-7402 cells of human hepatocellular carcinoma were inocu...Objective: To investigate anti-tumor effect of bufalin on the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice. Methods: BEL-7402 cells of human hepatocellular carcinoma were inoculated to form subcutaneous tumors in nude mice by subcutaneous injection. Then the subcutaneous tumors were implanted into the liver of nude mice, and the orthotopic transplantation tumor models of human hepatocellular carcinoma were established. Seventy-five models were randomized into 5 groups ( n = 15) . Bufalin was injected intraperitoneally into the 3 groups at dose of 1.5,1 and 0.5 mg/kg for day 15 - 24, respectively. NS group were injected equal volume saline as above and adriamycin were injected intraperitoneally into ADM group at dose of 8.0 mg/kg for day 15. Ten mice in each group were killed at day 25 and detected on morphological and ultrastructural changes in myocardium, brain, liver, kidney and tumor tissues by pathology and electron microscope. The survival time in each group were observed. Results: The tumor volumes in each group of bufalin were reduced significantly compared with NS group (P < 0.01), the survival time were prolonged in group Bu 1 and Bu 2 compared with NS group ( P < 0.05), and tumor tissues were mainly necrosis in severe or moderate degree in Bu 1, Bu 2 groups, and mild degree or moderate degree in Bu 3 group. No morphological changes were detected in myocardium, brain, liver and kidney tissues, respectively. Apoptotic characteristics could be seen in tumor tissues of group Bu 1 and group Bu 2. Conclusion: Bufalin has significant anti-tumor effects on the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice without marked toxicity. To guide cell apoptosis may be one of its anti-tumor mechanism of bufalin.展开更多
Hydraulic fracture is one of the key methods in well stimulation to increase production of oil and gas.Crack Opening Displacement(COD) is of great importance in this method since it is in direct relation with permeabi...Hydraulic fracture is one of the key methods in well stimulation to increase production of oil and gas.Crack Opening Displacement(COD) is of great importance in this method since it is in direct relation with permeability and production rate.In this paper COD is measured by a distinct element model which has been validated by an exact solution.A comprehensive study has been performed on confining pressure effect on COD which is neglected in the analytical solution.Numerical results showed that confining pressure considerably affects COD.A multi-parameter regression(considering effect of confining pressure,rock mass properties and fluid pressure) was performed on numerical results which resulted in an equation.The proposed equation considers the effect of confining pressure and its results are in good agreement with numerical results.展开更多
Objective: To establish a patient-like human ovary carcinoma /spontaneous metastasis model using orthotopic transplanation of histologically intact tumor tissue. Methods: An highly metastatic ovarian tumor line (HO-89...Objective: To establish a patient-like human ovary carcinoma /spontaneous metastasis model using orthotopic transplanation of histologically intact tumor tissue. Methods: An highly metastatic ovarian tumor line (HO-8910PM: Human serum carcinoma of the ovary )previously grown substaneously was transplanted into the ovicapsule using microsurgery technique .Histologically intact human ovary tumor pieces gained from implantation site were passaged between ovicapsules for four generations. Results: All mice developed ovary tumors and the metastatic rates were about 75%. The tumors only metastasized to liver but no other organs. The earliest appearance of metastasis was 14 d and the average survival period was 20.7±4.89 d.The microscopic appearance of the metastases was similar to the tumor observed in the substaneous xenografts and orthotopically transplanted. Chromosomes analysis exhibited the feature of human carcinoma and retained genetic stability during the processes of passage. Conclusion: Orthotopic implanation provides a suitable micro-enviroment in which ovarian cancer can express its intrinsic clinically-relevant properties. This approach is relevant to the spontaneous development of ovarian cancer and is thought to be a useful model for studies of metastatic mechanism and therapy for ovary cancer.展开更多
In order to compensate for the deficiency of present methods of monitoring plane displacement in similarity model tests,such as inadequate real-time monitoring and more manual intervention,an effective monitoring meth...In order to compensate for the deficiency of present methods of monitoring plane displacement in similarity model tests,such as inadequate real-time monitoring and more manual intervention,an effective monitoring method was proposed in this study,and the major steps of the monitoring method include:firstly,time-series images of the similarity model in the test were obtained by a camera,and secondly,measuring points marked as artificial targets were automatically tracked and recognized from time-series images.Finally,the real-time plane displacement field was calculated by the fixed magnification between objects and images under the specific conditions.And then the application device of the method was designed and tested.At the same time,a sub-pixel location method and a distortion error model were used to improve the measuring accuracy.The results indicate that this method may record the entire test,especially the detailed non-uniform deformation and sudden deformation.Compared with traditional methods this method has a number of advantages,such as greater measurement accuracy and reliability,less manual intervention,higher automation,strong practical properties,much more measurement information and so on.展开更多
基金National Natural Science Foundation of China(No.50004008)Xuzhou Power Supply Company and the Fundamental Research Funds for the Central Universities(No.2011QNB18) for their financial and technical support for this work
文摘Given the background of a transmission tower erected on a particular mining subsidence area,we used finite element modeling to analyze the anti-deformation performance of transmission towers under a number of different load conditions,including horizontal foundation displacement,uneven vertical downward displacement,wind loads and icing conditions.The results show that the failure in stability of a single steel angle iron represents the limit of the tower given ground deformation.We calculated the corresponding limits of foundation displacements.The results indicate that compression displacement of the foundation is more dangerous than tension displacement.Under complex foundation displacement conditions,horizontal foundation displacement is a key factor leading to failure in the stability of towers.Under conditions of compression or tension displacement of the foundation,wind load becomes the key factor.Towers do not fail when foundation displacements are smaller than 1% (under tension) or 0.5% (under horizontal compression or single foundation subsidence) of the distance between two supports.
基金Supported by National Natural Science Foundation of China (No.30200364)
文摘Objective: To investigate anti-tumor effect of bufalin on the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice. Methods: BEL-7402 cells of human hepatocellular carcinoma were inoculated to form subcutaneous tumors in nude mice by subcutaneous injection. Then the subcutaneous tumors were implanted into the liver of nude mice, and the orthotopic transplantation tumor models of human hepatocellular carcinoma were established. Seventy-five models were randomized into 5 groups ( n = 15) . Bufalin was injected intraperitoneally into the 3 groups at dose of 1.5,1 and 0.5 mg/kg for day 15 - 24, respectively. NS group were injected equal volume saline as above and adriamycin were injected intraperitoneally into ADM group at dose of 8.0 mg/kg for day 15. Ten mice in each group were killed at day 25 and detected on morphological and ultrastructural changes in myocardium, brain, liver, kidney and tumor tissues by pathology and electron microscope. The survival time in each group were observed. Results: The tumor volumes in each group of bufalin were reduced significantly compared with NS group (P < 0.01), the survival time were prolonged in group Bu 1 and Bu 2 compared with NS group ( P < 0.05), and tumor tissues were mainly necrosis in severe or moderate degree in Bu 1, Bu 2 groups, and mild degree or moderate degree in Bu 3 group. No morphological changes were detected in myocardium, brain, liver and kidney tissues, respectively. Apoptotic characteristics could be seen in tumor tissues of group Bu 1 and group Bu 2. Conclusion: Bufalin has significant anti-tumor effects on the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice without marked toxicity. To guide cell apoptosis may be one of its anti-tumor mechanism of bufalin.
文摘Hydraulic fracture is one of the key methods in well stimulation to increase production of oil and gas.Crack Opening Displacement(COD) is of great importance in this method since it is in direct relation with permeability and production rate.In this paper COD is measured by a distinct element model which has been validated by an exact solution.A comprehensive study has been performed on confining pressure effect on COD which is neglected in the analytical solution.Numerical results showed that confining pressure considerably affects COD.A multi-parameter regression(considering effect of confining pressure,rock mass properties and fluid pressure) was performed on numerical results which resulted in an equation.The proposed equation considers the effect of confining pressure and its results are in good agreement with numerical results.
文摘Objective: To establish a patient-like human ovary carcinoma /spontaneous metastasis model using orthotopic transplanation of histologically intact tumor tissue. Methods: An highly metastatic ovarian tumor line (HO-8910PM: Human serum carcinoma of the ovary )previously grown substaneously was transplanted into the ovicapsule using microsurgery technique .Histologically intact human ovary tumor pieces gained from implantation site were passaged between ovicapsules for four generations. Results: All mice developed ovary tumors and the metastatic rates were about 75%. The tumors only metastasized to liver but no other organs. The earliest appearance of metastasis was 14 d and the average survival period was 20.7±4.89 d.The microscopic appearance of the metastases was similar to the tumor observed in the substaneous xenografts and orthotopically transplanted. Chromosomes analysis exhibited the feature of human carcinoma and retained genetic stability during the processes of passage. Conclusion: Orthotopic implanation provides a suitable micro-enviroment in which ovarian cancer can express its intrinsic clinically-relevant properties. This approach is relevant to the spontaneous development of ovarian cancer and is thought to be a useful model for studies of metastatic mechanism and therapy for ovary cancer.
基金provided by the Program for New Century Excellent Talents in University (No. NCET-06-0477)the Independent Research Project of the State Key Laboratory of Coal Resources and Mine Safety of China University of Mining and Technology (No. SKLCRSM09X01)the Fundamental Research Funds for the Central Universities
文摘In order to compensate for the deficiency of present methods of monitoring plane displacement in similarity model tests,such as inadequate real-time monitoring and more manual intervention,an effective monitoring method was proposed in this study,and the major steps of the monitoring method include:firstly,time-series images of the similarity model in the test were obtained by a camera,and secondly,measuring points marked as artificial targets were automatically tracked and recognized from time-series images.Finally,the real-time plane displacement field was calculated by the fixed magnification between objects and images under the specific conditions.And then the application device of the method was designed and tested.At the same time,a sub-pixel location method and a distortion error model were used to improve the measuring accuracy.The results indicate that this method may record the entire test,especially the detailed non-uniform deformation and sudden deformation.Compared with traditional methods this method has a number of advantages,such as greater measurement accuracy and reliability,less manual intervention,higher automation,strong practical properties,much more measurement information and so on.
