目的:评价Perigee系统治疗女性前盆腔器官脱垂的安全性及临床疗效。方法 :对24例盆腔器官脱垂定量系统(pelvic organ prolapse-quantitation,POP-Q)诊断为Ⅱ度或以上的前盆腔器官脱垂患者行Perigee前盆底重建术,采用主观评价[盆底功能...目的:评价Perigee系统治疗女性前盆腔器官脱垂的安全性及临床疗效。方法 :对24例盆腔器官脱垂定量系统(pelvic organ prolapse-quantitation,POP-Q)诊断为Ⅱ度或以上的前盆腔器官脱垂患者行Perigee前盆底重建术,采用主观评价[盆底功能障碍影响问卷简版(PFIQ-7)、性生活质量问卷]和客观评价(POP-Q)对围手术期及术后近期各项指标的变化及并发症发生情况进行分析。结果:24例患者的平均手术时间(70.83±15.30)min,术中平均出血(80.92±40.39)ml,术后中位随访时间为4个月。以POP-Q评分作为客观疗效评价指标,治愈率为100%;PFIQ-7评分较术前有显著改善;术后1例有性生活,性生活质量无明显下降。术后发生网片暴露1例(4.2%);新发压力性尿失禁2例(8.4%);会阴部、臀部疼痛4例(16.7%);新发阴道后壁脱垂3例(12.6%);无严重并发症发生。结论:Perigee系统是治疗前盆腔脏器脱垂的安全、微创术式,近期疗效肯定,中远期疗效待进一步随访。展开更多
For the final stage of a launch vehicle which cannot start multiple times,the main constraint of a highly eccentric orbit launch mission is the argument of perigee,which is conditioned by the range.This paper studies ...For the final stage of a launch vehicle which cannot start multiple times,the main constraint of a highly eccentric orbit launch mission is the argument of perigee,which is conditioned by the range.This paper studies the payload capacity at different launch sites for a highly eccentric orbit(e.g.GTO)and gives a method to improve the payload capacity with an argument of perigee constraint by increasing the sliding time before the final ignition and simultaneously adjusting the launch azimuth and yaw at the final stage.An example of launching to GTO orbit on a rocket from Hainan is given,which proves that the method has strong engineering value.展开更多
Basic resources for communication satellites are communication radio-frequencies and satellite orbits. An orbit is the trajectory followed by the satellite. The communication between the satellite and a ground station...Basic resources for communication satellites are communication radio-frequencies and satellite orbits. An orbit is the trajectory followed by the satellite. The communication between the satellite and a ground station is established only when the satellite is consolidated in its own orbit and it is visible from the ground station. Different types of orbits are possible, each suitable for a specific application or mission. Most used orbits are circular, categorized as low, medium and geosynchronous (geostationary) orbits based on the attitude above the Earths surface. The launching process heading the satellite in geostationary orbit, by the first step places the satellite in a transfer orbit. The transfer orbit is elliptical in shape with low attitude at perigee, and the apogee of the geostationary orbit attitude. The apogee of the parking orbit depends on the injection velocity applied at perigee. Simulation approach of injection velocity at perigee to attain different apogees, considering an incremental step is presented in this paper.展开更多
In this paper we emphasize statistical links between solar activity and orbital motion with various terrestrial phenomena: terrestrial temperature, sea levels, ice areas, frequencies of volcanic eruptions, and Oceanic...In this paper we emphasize statistical links between solar activity and orbital motion with various terrestrial phenomena: terrestrial temperature, sea levels, ice areas, frequencies of volcanic eruptions, and Oceanic Nino Index (ONI). Solar activity links. The solar activity indices are expressed through the averaged sunspot numbers SSN and the summary curve of eigen vectors of the solar background magnetic field (SBMF). The terrestrial temperature (GLB dataset), global sea level, and volcanic eruption frequencies are shown from the wavelet analysis to have a clear link to the SBMF index, which has the same significant period of 21.4 years. The ice and snow areas in the Northern hemisphere are found to vary with a period of 10.7 years equal to the usual sunspot activity cycle while in the Southern hemispheres, no links to solar activity are detected. Solar orbital motion links. The variations of total solar irradiance (TSI) measured from the abundance of 14C isotope during the Holocene are shown to have a similar period of 2200-2300 years (Hallstatt’s cycle) as the solar inertial motion (SIM) induced by the gravitation of large planets, In the current millennium the amount of TSI deposited on Earth in the March-September to Northern hemisphere is ≈1.2% higher than in the September to March in the Southern hemisphere. The wavelet analysis of ONI revealed the two significant periods of 4.5 and 12 years. The first one is shown to have a link to the lunar perigee period variations while the second period is linked to the Jupiter period of revolution about the Sun whose gravitation seems to trigger terrestrial tectonic processes leading to volcanic eruptions. The ONI variation is noticeably linked to the occurrence of underwater volcanic eruptions (correlation of 25%), which, in turn, are linked to the tidal forces of Jupiter, the Moon and the Sun in its inertial motion. Joint effects of the solar activity and the solar and planetary orbital motion are likely to govern the current changes in the terrestrial environment defining continuing climate change.展开更多
The primary technique used for air traffic surveillance is radar.However,nowadays,its role in surveillance is gradually being replaced by the recently adopted Automatic Dependent Surveillance-Broadcast(ADS-B).ADS-B of...The primary technique used for air traffic surveillance is radar.However,nowadays,its role in surveillance is gradually being replaced by the recently adopted Automatic Dependent Surveillance-Broadcast(ADS-B).ADS-B offers a higher accuracy,lower power consumption,and longer range than radar,thus providing more safety to aircraft.The coverage of terrestrial radar and ADS-B is confined to continental parts of the globe,leaving oceans and poles uncovered by real-time surveillance measures.This study presents an optimized Low-Earth Orbit(LEO)-based ADS-B constellation for global air traffic surveillance over intercontinental trans-oceanic flight routes.The optimization algorithm is based on performance evaluation parameters,i.e.,coverage time,satellite availability,and orbit stability(precession and perigee rotation),and communication analysis.The results indicate that the constellation provides ample coverage in the simulated global oceanic regions.The constellation is a feasible and cost-effective solution for global air supervision,which can supplement terrestrial ADS-B and radar systems.展开更多
文摘目的:评价Perigee系统治疗女性前盆腔器官脱垂的安全性及临床疗效。方法 :对24例盆腔器官脱垂定量系统(pelvic organ prolapse-quantitation,POP-Q)诊断为Ⅱ度或以上的前盆腔器官脱垂患者行Perigee前盆底重建术,采用主观评价[盆底功能障碍影响问卷简版(PFIQ-7)、性生活质量问卷]和客观评价(POP-Q)对围手术期及术后近期各项指标的变化及并发症发生情况进行分析。结果:24例患者的平均手术时间(70.83±15.30)min,术中平均出血(80.92±40.39)ml,术后中位随访时间为4个月。以POP-Q评分作为客观疗效评价指标,治愈率为100%;PFIQ-7评分较术前有显著改善;术后1例有性生活,性生活质量无明显下降。术后发生网片暴露1例(4.2%);新发压力性尿失禁2例(8.4%);会阴部、臀部疼痛4例(16.7%);新发阴道后壁脱垂3例(12.6%);无严重并发症发生。结论:Perigee系统是治疗前盆腔脏器脱垂的安全、微创术式,近期疗效肯定,中远期疗效待进一步随访。
文摘For the final stage of a launch vehicle which cannot start multiple times,the main constraint of a highly eccentric orbit launch mission is the argument of perigee,which is conditioned by the range.This paper studies the payload capacity at different launch sites for a highly eccentric orbit(e.g.GTO)and gives a method to improve the payload capacity with an argument of perigee constraint by increasing the sliding time before the final ignition and simultaneously adjusting the launch azimuth and yaw at the final stage.An example of launching to GTO orbit on a rocket from Hainan is given,which proves that the method has strong engineering value.
文摘Basic resources for communication satellites are communication radio-frequencies and satellite orbits. An orbit is the trajectory followed by the satellite. The communication between the satellite and a ground station is established only when the satellite is consolidated in its own orbit and it is visible from the ground station. Different types of orbits are possible, each suitable for a specific application or mission. Most used orbits are circular, categorized as low, medium and geosynchronous (geostationary) orbits based on the attitude above the Earths surface. The launching process heading the satellite in geostationary orbit, by the first step places the satellite in a transfer orbit. The transfer orbit is elliptical in shape with low attitude at perigee, and the apogee of the geostationary orbit attitude. The apogee of the parking orbit depends on the injection velocity applied at perigee. Simulation approach of injection velocity at perigee to attain different apogees, considering an incremental step is presented in this paper.
文摘In this paper we emphasize statistical links between solar activity and orbital motion with various terrestrial phenomena: terrestrial temperature, sea levels, ice areas, frequencies of volcanic eruptions, and Oceanic Nino Index (ONI). Solar activity links. The solar activity indices are expressed through the averaged sunspot numbers SSN and the summary curve of eigen vectors of the solar background magnetic field (SBMF). The terrestrial temperature (GLB dataset), global sea level, and volcanic eruption frequencies are shown from the wavelet analysis to have a clear link to the SBMF index, which has the same significant period of 21.4 years. The ice and snow areas in the Northern hemisphere are found to vary with a period of 10.7 years equal to the usual sunspot activity cycle while in the Southern hemispheres, no links to solar activity are detected. Solar orbital motion links. The variations of total solar irradiance (TSI) measured from the abundance of 14C isotope during the Holocene are shown to have a similar period of 2200-2300 years (Hallstatt’s cycle) as the solar inertial motion (SIM) induced by the gravitation of large planets, In the current millennium the amount of TSI deposited on Earth in the March-September to Northern hemisphere is ≈1.2% higher than in the September to March in the Southern hemisphere. The wavelet analysis of ONI revealed the two significant periods of 4.5 and 12 years. The first one is shown to have a link to the lunar perigee period variations while the second period is linked to the Jupiter period of revolution about the Sun whose gravitation seems to trigger terrestrial tectonic processes leading to volcanic eruptions. The ONI variation is noticeably linked to the occurrence of underwater volcanic eruptions (correlation of 25%), which, in turn, are linked to the tidal forces of Jupiter, the Moon and the Sun in its inertial motion. Joint effects of the solar activity and the solar and planetary orbital motion are likely to govern the current changes in the terrestrial environment defining continuing climate change.
文摘The primary technique used for air traffic surveillance is radar.However,nowadays,its role in surveillance is gradually being replaced by the recently adopted Automatic Dependent Surveillance-Broadcast(ADS-B).ADS-B offers a higher accuracy,lower power consumption,and longer range than radar,thus providing more safety to aircraft.The coverage of terrestrial radar and ADS-B is confined to continental parts of the globe,leaving oceans and poles uncovered by real-time surveillance measures.This study presents an optimized Low-Earth Orbit(LEO)-based ADS-B constellation for global air traffic surveillance over intercontinental trans-oceanic flight routes.The optimization algorithm is based on performance evaluation parameters,i.e.,coverage time,satellite availability,and orbit stability(precession and perigee rotation),and communication analysis.The results indicate that the constellation provides ample coverage in the simulated global oceanic regions.The constellation is a feasible and cost-effective solution for global air supervision,which can supplement terrestrial ADS-B and radar systems.
