The Sulige gas field is a typical low-pressure low-permeability tight sandstone gas reservoir. The reservoir has poor seepage capacity, strong heterogeneity, high mineralization of formation water and extremely scarce...The Sulige gas field is a typical low-pressure low-permeability tight sandstone gas reservoir. The reservoir has poor seepage capacity, strong heterogeneity, high mineralization of formation water and extremely scarce water resources on the site. These unfavorable factors have brought great difficulties to the on-site mining process. Now, a nano-composite green environmental protection slick water fracturing fluid system CQFR can be quickly dissolved because of the larger specific surface area, and the small molecular size makes the damage to the reservoir less than 5%, and the average drag reduction effect can reach more than 73%. It can quickly and well dissolve and maintain performance under high salinity conditions and fracturing flowback fluids. It responds well to the complex reservoir conditions on the construction site and makes the flowback fluid recyable, which greatly reduces the consumption of water resources on the construction site and effectively improves the construction efficiency and economic benefits.展开更多
BACKGROUND Dieulafoy's lesion is a rare vascular abnormality characterized by a small abnormally dilated artery that runs a tortuous course in the submucosa.There is usually no ulcer present in Dieulafoy's les...BACKGROUND Dieulafoy's lesion is a rare vascular abnormality characterized by a small abnormally dilated artery that runs a tortuous course in the submucosa.There is usually no ulcer present in Dieulafoy's lesions and the overlying mucosa is most often normal.Bleeding caused by a Dieulafoy's lesion is usually urgent,massive,life-threatening and prone to recurrence.Dieulafoy's lesions have been reported throughout the digestive tract although the majority of them have been found in the upper digestive tract especially the stomach and duodenum.However,a Dieulafoy's lesion occurring inside a duodenal diverticulum is very rare.CASE SUMMARY A 74-year-old Asian male with epigastric pain,hematemesis and melena was admitted to our clinic.Before admission,the patient had vomited 500 m L of dark red blood,and passed 200 g of black tarry stool.Conservative management was first undertaken as the patient had not been fasting.However,hemorrhage recurred and the patient went into shock.Urgent endoscopy was performed and a diverticulum of 1.8 cm×1.2 cm×0.8 cm was found on the anterior wall of the descending duodenum.The diverticulum was covered with a blood clot.After the clot was removed,an artery stump was observed in the diverticulum with a diameter of 2-3 mm.Two titanium hemostatic clips were inserted to clamp the vessel stump.The patient was discharged 7 d post-endoscopy and followed for 6 mo with no recurrence.CONCLUSION This case was diagnosed with a Dieulafoy's lesion inside a duodenal diverticulum which has rarely been reported.Hematemesis was stopped by clamping the vessel stump with titanium clips.No complications occurred.展开更多
A 325-MHz continuous-wave(CW) four-vane radiofrequency quadrupole(RFQ) is employed in Injector-I of the China Accelerator-Driven Subcritical System. The radiofrequency tuning and beam commissioning were performed from...A 325-MHz continuous-wave(CW) four-vane radiofrequency quadrupole(RFQ) is employed in Injector-I of the China Accelerator-Driven Subcritical System. The radiofrequency tuning and beam commissioning were performed from January 2014 to January 2017. In a cold test, a stability study showed that the design of the segmented resonantly coupling and dipole stabilizer rods can shift the harmful quadrupole and dipole mode from the fundamental mode to above 2.6 MHz. We also found a simplified tuning method for the field unflatness, involving changing the inserted length of a few plug tuners. For achieving CW-beam commissioning, two full-size RFQs were constructed successively. The commissioning results indicate that the beam transmission rate decreased by approximately 3% as the normalized field unflatness decreased by 1%. A 10-MeV CW proton beam with an average beam current of 2.1 m A was achieved at the target of Injector-I, and the output beam energy of the RFQ was3.18 MeV.展开更多
The High Energy Photon Source(HEPS)is a 6 GeV diffraction-limited storage ring light source under construction.The swap-out injection is adopted with the depleted bunch recycled via high-energy accumulation in the boo...The High Energy Photon Source(HEPS)is a 6 GeV diffraction-limited storage ring light source under construction.The swap-out injection is adopted with the depleted bunch recycled via high-energy accumulation in the booster.The extremely high beam energy density of the bunches with an ultra-low emittance(about 30 pm horizontally and 3 pm vertically)and high bunch charges(from 1.33 to 14.4 nC)extracted from the storage ring could cause hazardous damage to the extraction Lambertson magnet in case of extraction kicker failure.To this end,we proposed the use of a pre-kicker to spoil the bunches prior to extraction,significantly reducing the maximum beam energy density down to within a safe region while still maintaining highly efficient extractions.The main parameters of the pre-kicker are simulated and discussed.展开更多
The 10-MeV Accelerator-Driven Subcritical(ADS)system Injector-I test stand at the Institute of High Energy Physics(IHEP)is a testing facility dedicated to demonstrating the feasibility of the spoke-based super-conduct...The 10-MeV Accelerator-Driven Subcritical(ADS)system Injector-I test stand at the Institute of High Energy Physics(IHEP)is a testing facility dedicated to demonstrating the feasibility of the spoke-based super-conducting(SC)linear accelerator(linac)for the ADS project in China.The injector adopted a four-vane copper structure radio frequency quadrupole(RFQ)with an output energy of 3.2 MeV and an SC section accommodating 14 β_(g)=0.12 single spoke cavities,14 SC solenoids,and 14 cold beam position monitors(BPMs).A 10-MeV pulsed beam with a beam current of 10 mA and a 2-mA continuous wave(CW)beam were successfully shooting through.The commissioning results confirmed the feasibility of using a 325-MHz spoke-type cavity for accelerating the proton beam in the low β and medium β sections.This paper describes the results achieved,the difficulties encountered,and the experiences obtained during commissioning.展开更多
The Appellate Body report in January 2012 had supported the decision of Panel in the"China-measures related to the exportation of various raw materials"case(WT/DS394,395,398)and affirmed that China's res...The Appellate Body report in January 2012 had supported the decision of Panel in the"China-measures related to the exportation of various raw materials"case(WT/DS394,395,398)and affirmed that China's restrictions(such as tariffs and quota measures)on the exportation of raw materials violated rules put forth by the WTO,which were required to be modified.In this case China's right to invoke Article 20 of GATT1994("general exception")to justify its exemption from the guidelines in Article 11.3 of the WTO Accession Protocol was denied by the Panel and the Appellate Body.This was due to the fact that the phrasing in Article 11.3 of Protocol failed to mention"GATT."This was the consequence of the two interpretation approaches the Dispute Settlement Body(DSB)adopted-a narrow textual interpretation and a subjective presumption of"legislative silence."The inappropriate use of the two methods of interpretation lead to an imbalance between the right and obligation of China under the additional obligations that were imposed upon China by the WTO,which create a negative impact on China's rare earth case and the protection of domestic natural resources.展开更多
Hypoxia is closely related to many diseases and often leads to death.Early detection andidentification of the hypoxia causes may help to promptly determine the right rescue plan andreduce the mortality.We proposed a n...Hypoxia is closely related to many diseases and often leads to death.Early detection andidentification of the hypoxia causes may help to promptly determine the right rescue plan andreduce the mortality.We proposed a new multiparametric monitoring method employingmitochondrial reduced nicotinamide adenine dinucleotide(NA DH)fluorescence,regional reflectance,regional cerebral blood flow(CBF),electrocardiography(ECG),and respiration under sixkinds of acute hypoxia in four categories to investigate a correlation bet ween the parametervariances and the hypoxia causes.The variation patterns of the paramet ers were discussed,andthe combination of NADH and CBF may contribute to the identification of the causes of hypoxia.展开更多
文摘The Sulige gas field is a typical low-pressure low-permeability tight sandstone gas reservoir. The reservoir has poor seepage capacity, strong heterogeneity, high mineralization of formation water and extremely scarce water resources on the site. These unfavorable factors have brought great difficulties to the on-site mining process. Now, a nano-composite green environmental protection slick water fracturing fluid system CQFR can be quickly dissolved because of the larger specific surface area, and the small molecular size makes the damage to the reservoir less than 5%, and the average drag reduction effect can reach more than 73%. It can quickly and well dissolve and maintain performance under high salinity conditions and fracturing flowback fluids. It responds well to the complex reservoir conditions on the construction site and makes the flowback fluid recyable, which greatly reduces the consumption of water resources on the construction site and effectively improves the construction efficiency and economic benefits.
文摘BACKGROUND Dieulafoy's lesion is a rare vascular abnormality characterized by a small abnormally dilated artery that runs a tortuous course in the submucosa.There is usually no ulcer present in Dieulafoy's lesions and the overlying mucosa is most often normal.Bleeding caused by a Dieulafoy's lesion is usually urgent,massive,life-threatening and prone to recurrence.Dieulafoy's lesions have been reported throughout the digestive tract although the majority of them have been found in the upper digestive tract especially the stomach and duodenum.However,a Dieulafoy's lesion occurring inside a duodenal diverticulum is very rare.CASE SUMMARY A 74-year-old Asian male with epigastric pain,hematemesis and melena was admitted to our clinic.Before admission,the patient had vomited 500 m L of dark red blood,and passed 200 g of black tarry stool.Conservative management was first undertaken as the patient had not been fasting.However,hemorrhage recurred and the patient went into shock.Urgent endoscopy was performed and a diverticulum of 1.8 cm×1.2 cm×0.8 cm was found on the anterior wall of the descending duodenum.The diverticulum was covered with a blood clot.After the clot was removed,an artery stump was observed in the diverticulum with a diameter of 2-3 mm.Two titanium hemostatic clips were inserted to clamp the vessel stump.The patient was discharged 7 d post-endoscopy and followed for 6 mo with no recurrence.CONCLUSION This case was diagnosed with a Dieulafoy's lesion inside a duodenal diverticulum which has rarely been reported.Hematemesis was stopped by clamping the vessel stump with titanium clips.No complications occurred.
文摘A 325-MHz continuous-wave(CW) four-vane radiofrequency quadrupole(RFQ) is employed in Injector-I of the China Accelerator-Driven Subcritical System. The radiofrequency tuning and beam commissioning were performed from January 2014 to January 2017. In a cold test, a stability study showed that the design of the segmented resonantly coupling and dipole stabilizer rods can shift the harmful quadrupole and dipole mode from the fundamental mode to above 2.6 MHz. We also found a simplified tuning method for the field unflatness, involving changing the inserted length of a few plug tuners. For achieving CW-beam commissioning, two full-size RFQs were constructed successively. The commissioning results indicate that the beam transmission rate decreased by approximately 3% as the normalized field unflatness decreased by 1%. A 10-MeV CW proton beam with an average beam current of 2.1 m A was achieved at the target of Injector-I, and the output beam energy of the RFQ was3.18 MeV.
基金the National Natural Science Foundation of China(Nos.11605212,11475200,and 11675194)Youth Innovation Promotion Association CAS(No.2021012)High Energy Photon Source(HEPS),a major national science and technology infrastructure in China.
文摘The High Energy Photon Source(HEPS)is a 6 GeV diffraction-limited storage ring light source under construction.The swap-out injection is adopted with the depleted bunch recycled via high-energy accumulation in the booster.The extremely high beam energy density of the bunches with an ultra-low emittance(about 30 pm horizontally and 3 pm vertically)and high bunch charges(from 1.33 to 14.4 nC)extracted from the storage ring could cause hazardous damage to the extraction Lambertson magnet in case of extraction kicker failure.To this end,we proposed the use of a pre-kicker to spoil the bunches prior to extraction,significantly reducing the maximum beam energy density down to within a safe region while still maintaining highly efficient extractions.The main parameters of the pre-kicker are simulated and discussed.
基金This work was supported by Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA03030201)the Key Laboratory of Particle Acceleration Physics and Technology Autonomous Foundation of CAS China(No.JSQ2017ZZ01).
文摘The 10-MeV Accelerator-Driven Subcritical(ADS)system Injector-I test stand at the Institute of High Energy Physics(IHEP)is a testing facility dedicated to demonstrating the feasibility of the spoke-based super-conducting(SC)linear accelerator(linac)for the ADS project in China.The injector adopted a four-vane copper structure radio frequency quadrupole(RFQ)with an output energy of 3.2 MeV and an SC section accommodating 14 β_(g)=0.12 single spoke cavities,14 SC solenoids,and 14 cold beam position monitors(BPMs).A 10-MeV pulsed beam with a beam current of 10 mA and a 2-mA continuous wave(CW)beam were successfully shooting through.The commissioning results confirmed the feasibility of using a 325-MHz spoke-type cavity for accelerating the proton beam in the low β and medium β sections.This paper describes the results achieved,the difficulties encountered,and the experiences obtained during commissioning.
文摘The Appellate Body report in January 2012 had supported the decision of Panel in the"China-measures related to the exportation of various raw materials"case(WT/DS394,395,398)and affirmed that China's restrictions(such as tariffs and quota measures)on the exportation of raw materials violated rules put forth by the WTO,which were required to be modified.In this case China's right to invoke Article 20 of GATT1994("general exception")to justify its exemption from the guidelines in Article 11.3 of the WTO Accession Protocol was denied by the Panel and the Appellate Body.This was due to the fact that the phrasing in Article 11.3 of Protocol failed to mention"GATT."This was the consequence of the two interpretation approaches the Dispute Settlement Body(DSB)adopted-a narrow textual interpretation and a subjective presumption of"legislative silence."The inappropriate use of the two methods of interpretation lead to an imbalance between the right and obligation of China under the additional obligations that were imposed upon China by the WTO,which create a negative impact on China's rare earth case and the protection of domestic natural resources.
基金supported bythe 111 Project of China(B07038)alsosupported by the Ph.D.Programs Foundation of the Mimnistry of Education of China(Grant_No.20110142130006)the Director Fund of Wuhan National Laboratory for Optoelectronics(WNLO,2009,Z.H.ZHANG).
文摘Hypoxia is closely related to many diseases and often leads to death.Early detection andidentification of the hypoxia causes may help to promptly determine the right rescue plan andreduce the mortality.We proposed a new multiparametric monitoring method employingmitochondrial reduced nicotinamide adenine dinucleotide(NA DH)fluorescence,regional reflectance,regional cerebral blood flow(CBF),electrocardiography(ECG),and respiration under sixkinds of acute hypoxia in four categories to investigate a correlation bet ween the parametervariances and the hypoxia causes.The variation patterns of the paramet ers were discussed,andthe combination of NADH and CBF may contribute to the identification of the causes of hypoxia.
