Tight sandstone gas(hereafter"tight gas")has become a subject of unconventional gas exploration globally.The large-scale development and use of tight gas resources in the USA,in particular,facilitated the ra...Tight sandstone gas(hereafter"tight gas")has become a subject of unconventional gas exploration globally.The large-scale development and use of tight gas resources in the USA,in particular,facilitated the rapid rebound of natural gas production in the USA,in addition to driving the rapid development of tight gas worldwide.In the eastern Ordos Basin,the Upper Paleozoic feature includes multiple layers of gas,a shallow depth,and notable potential for exploration and development.However,the reservoirs in the area are relatively tight,exhibit strong heterogeneity,and possess a complex micropore structure,thus restricting the eff ective economic development of oil and gas.Thus,research on the primary parameters controlling pore throat structure and the seepage capability of low-permeability reservoirs will be beneficial for the effcient exploration and development of natural gas in the eastern Ordos Basin.The parameters of reservoir porosity and percolation ability,as well as permeability,were analyzed using systematic sampling of the of the Upper Paleozoic Benxi,Taiyuan,and Shanxi Formations in the eastern Ordos Basin,constant-rate mercury injection experiments,nuclear magnetic resonance analysis,and gas–water-phase experimental studies.The results indicate that reservoir porosity is controlled by the effective pore volume and number,whereas permeability is controlled by the largest throat radius,rather than the average.The effective pore volume controls the movable fluid saturation,while reservoir percolation capability is controlled by the effective pore volume,irreducible water saturation,and size of the gas–water two-phase seepage zone.展开更多
BACKGROUND Epithelioid trophoblastic tumor(ETT)is a special type of gestational trophoblastic tumor.However,its pathogenesis has been incompletely elucidated.ETT rarely occurs in the ovaries and fallopian tubes,unlike...BACKGROUND Epithelioid trophoblastic tumor(ETT)is a special type of gestational trophoblastic tumor.However,its pathogenesis has been incompletely elucidated.ETT rarely occurs in the ovaries and fallopian tubes,unlike placental site trophoblastic tumor,requiring a histopathological biopsy and immunohistochemistry for further diagnosis.CASE SUMMARY A 29-year-old woman with irregular vaginal bleeding and elevated serum chorionic gonadotropin(β-hCG)levels presented similar symptoms to ectopic pregnancy.Transvaginal ultrasound revealed abnormal echoes of the left adnexa.Postoperatively,the pathology of the left ovary and fallopian tube was reported as ETT.The patient was followed up with regular hCG measurements and ultrasounds.The blood hCG values showed an upward trend 3 mo after the operation and then chemotherapy was prescribed.The current health status is normal.CONCLUSION For women of childbearing age with elevated serumβ-hCG levels,practitioners should consider ETT and be alert to the poor prognosis of the disease.After surgery,the patient’s condition should be closely observed to prevent recurrence and metastasis.Postoperative chemotherapy is only helpful for treating the disease to a certain extent.展开更多
BACKGROUND Malignant tumors of the appendix are extremely rare,constituting about 1%of all gastrointestinal tumors.Generally,pathology identifies these tumors during or after appendectomy because they are difficult to...BACKGROUND Malignant tumors of the appendix are extremely rare,constituting about 1%of all gastrointestinal tumors.Generally,pathology identifies these tumors during or after appendectomy because they are difficult to detect at the preoperative stage.This case report aims to introduce the definitive diagnosis and treatment of mucinous adenocarcinoma of the appendix.CASE SUMMARY A 49-year-old female patient came to our hospital with right lower abdominal pain,nausea,and vomiting for three days.There was no change in the menstrual cycle.Gynecological ultrasound showed a cystic,solid mass in the right adnexa.Abdominal enhanced computed tomography showed a thick appendix.Cancer was found on exploration of the appendix during gynecological surgery.The right colon was removed.After surgery,the patient received chemotherapy and is recovering well.CONCLUSION Appendiceal carcinoma is frequently found during or after surgery,and both preoperative examination and early evaluation of clinical manifestations are extremely important.展开更多
Rapidity-dependent transverse momentum spectra of negatively charged pions measured at different rapidities in proton-proton collisions at the Super Proton Synchrotron （SPS） at various energies within its Beam Energ...Rapidity-dependent transverse momentum spectra of negatively charged pions measured at different rapidities in proton-proton collisions at the Super Proton Synchrotron （SPS） at various energies within its Beam Energy Scan （BES） program are investigated by using one- and two-component standard distributions where the chemical potential and spin property of particles are implemented. The rapidity spectra are described by a double- Gaussian distribution. At the stage of kinetic freeze-out, the event patterns are structured by the scatter plots in the three-dimensional subspaces of velocity, momentum and rapidity. The results of the studies of the rapidityindependent transverse mass spectra measured at mid-rapidity in proton-proton collisions are compared with those based on the similar transverse mass spectra measured in the most central beryllium-beryllium, argon-scandium and lead-lead collisions from the SPS at its BES energies.展开更多
基金supported by the National Natural Science Foundation of China(Grants Nos.41390451 and 41172101)the National Key Research Project of China(No.2016YFC0601003)
文摘Tight sandstone gas(hereafter"tight gas")has become a subject of unconventional gas exploration globally.The large-scale development and use of tight gas resources in the USA,in particular,facilitated the rapid rebound of natural gas production in the USA,in addition to driving the rapid development of tight gas worldwide.In the eastern Ordos Basin,the Upper Paleozoic feature includes multiple layers of gas,a shallow depth,and notable potential for exploration and development.However,the reservoirs in the area are relatively tight,exhibit strong heterogeneity,and possess a complex micropore structure,thus restricting the eff ective economic development of oil and gas.Thus,research on the primary parameters controlling pore throat structure and the seepage capability of low-permeability reservoirs will be beneficial for the effcient exploration and development of natural gas in the eastern Ordos Basin.The parameters of reservoir porosity and percolation ability,as well as permeability,were analyzed using systematic sampling of the of the Upper Paleozoic Benxi,Taiyuan,and Shanxi Formations in the eastern Ordos Basin,constant-rate mercury injection experiments,nuclear magnetic resonance analysis,and gas–water-phase experimental studies.The results indicate that reservoir porosity is controlled by the effective pore volume and number,whereas permeability is controlled by the largest throat radius,rather than the average.The effective pore volume controls the movable fluid saturation,while reservoir percolation capability is controlled by the effective pore volume,irreducible water saturation,and size of the gas–water two-phase seepage zone.
文摘BACKGROUND Epithelioid trophoblastic tumor(ETT)is a special type of gestational trophoblastic tumor.However,its pathogenesis has been incompletely elucidated.ETT rarely occurs in the ovaries and fallopian tubes,unlike placental site trophoblastic tumor,requiring a histopathological biopsy and immunohistochemistry for further diagnosis.CASE SUMMARY A 29-year-old woman with irregular vaginal bleeding and elevated serum chorionic gonadotropin(β-hCG)levels presented similar symptoms to ectopic pregnancy.Transvaginal ultrasound revealed abnormal echoes of the left adnexa.Postoperatively,the pathology of the left ovary and fallopian tube was reported as ETT.The patient was followed up with regular hCG measurements and ultrasounds.The blood hCG values showed an upward trend 3 mo after the operation and then chemotherapy was prescribed.The current health status is normal.CONCLUSION For women of childbearing age with elevated serumβ-hCG levels,practitioners should consider ETT and be alert to the poor prognosis of the disease.After surgery,the patient’s condition should be closely observed to prevent recurrence and metastasis.Postoperative chemotherapy is only helpful for treating the disease to a certain extent.
文摘BACKGROUND Malignant tumors of the appendix are extremely rare,constituting about 1%of all gastrointestinal tumors.Generally,pathology identifies these tumors during or after appendectomy because they are difficult to detect at the preoperative stage.This case report aims to introduce the definitive diagnosis and treatment of mucinous adenocarcinoma of the appendix.CASE SUMMARY A 49-year-old female patient came to our hospital with right lower abdominal pain,nausea,and vomiting for three days.There was no change in the menstrual cycle.Gynecological ultrasound showed a cystic,solid mass in the right adnexa.Abdominal enhanced computed tomography showed a thick appendix.Cancer was found on exploration of the appendix during gynecological surgery.The right colon was removed.After surgery,the patient received chemotherapy and is recovering well.CONCLUSION Appendiceal carcinoma is frequently found during or after surgery,and both preoperative examination and early evaluation of clinical manifestations are extremely important.
基金Supported by National Natural Science Foundation of China(11575103,11747319)the Shanxi Provincial Natural Science Foundation(201701D121005)the Fund for Shanxi "1331 Project" Key Subjects Construction
文摘Rapidity-dependent transverse momentum spectra of negatively charged pions measured at different rapidities in proton-proton collisions at the Super Proton Synchrotron （SPS） at various energies within its Beam Energy Scan （BES） program are investigated by using one- and two-component standard distributions where the chemical potential and spin property of particles are implemented. The rapidity spectra are described by a double- Gaussian distribution. At the stage of kinetic freeze-out, the event patterns are structured by the scatter plots in the three-dimensional subspaces of velocity, momentum and rapidity. The results of the studies of the rapidityindependent transverse mass spectra measured at mid-rapidity in proton-proton collisions are compared with those based on the similar transverse mass spectra measured in the most central beryllium-beryllium, argon-scandium and lead-lead collisions from the SPS at its BES energies.
