球探技术在成人退行性脊柱侧弯矫形术中的应用

目的探讨球探技术在成人退行性脊柱侧弯矫形术中的应用,并与传统徒手置钉法进行比较,以评估该技术的安全性及准确性。方法选取2014年3月—2019年1月诊断为成人退行性脊柱侧弯,且行胸腰椎后路侧弯矫形术的患者共30例。将术中应用传统徒手置钉技术的15例患者纳入对照组,应用球探技术辅助下置钉的15例患者纳入实验组。分别比较2组置钉准确率与平均置钉时间。结果对照组椎弓根完美置入145枚(81.46%),临床标准162枚(91.01%),置入不良为16枚(8.99%)。实验组椎弓根完美置入153枚(88.95%),临床标准为167枚(97.09%),置入不良为5枚(2.91%)。2组进行统计学分析显示:实验组椎弓根螺钉完美置入率及临床标准置入率均优于对照组,差异有统计学意义(P<0.05)。对照组椎弓根螺钉平均置钉时间为(2.87±1.15)min;实验组为(3.12±2.20)min,2组相比差异无统计学意义(P>0.05)。2组均未出现椎弓根螺钉相关的脑脊液漏、切口深部感染或神经及血管损伤等并发症。结论球探技术辅助置钉在退行性脊柱侧弯矫形手术中,可获得比传统徒手置钉法更高的置钉准确率,且不增加操作时间,是一种安全可靠的置钉方法。

应用“漏斗法”和“球探技术”椎弓根植钉治疗上胸椎骨折临床效果分析

目的 探讨“漏斗法”联合“球探技术”置入椎弓根螺钉治疗上胸椎骨折的临床疗效。方法 回顾性分析采用“漏斗法”结合“球探技术”椎弓根植钉法治疗7例上胸椎骨折患者的临床资料,观察术后并发症、椎弓根螺钉位置、置钉失败率、术后神经功能恢复和植骨愈合情况。结果 7例患者共置入上胸椎椎弓根钉59枚,CT断层扫描显示无椎弓根内壁及前壁穿透,首次置钉成功率为93.2%;术中和术后均未出现血管、神经损伤及脑脊液漏等并发症;术后随访8~24个月,患者切口均一期愈合,后凸角纠正（11.0±3.3）°;无内固定松动、断裂发生,ASIA分级较术前改善;术后3~5个月,7例均达骨性融合。结论 “漏斗法”联合“球探技术”椎弓根螺钉置入治疗上胸椎骨折的实用性和安全性良好。

球探技术在老年髋部骨折髓内钉内固定手术中的应用

目的:探讨"球探技术"(Ball Tip Technique)在老年髋部骨折髓内钉内固定术中精确控制"尖顶距"(Tip-apex Distance,TAD)的应用价值。方法:回顾分析38例应用"球探技术"的老年股骨粗隆间骨折髓内钉内固定患者术后的TAD值以及患者术后内固定失败、骨折愈合和患者功能恢复的情况。结果:术后TAD值为18~28mm,平均21.45mm,无穿出股骨头病例。随访时间6~18个月,平均10个月。骨折全部愈合,愈合时间为13~26周,平均16周,无内固定失效病例。按Parkland和Palmer活动能力评分,7~9分11例,4~6分21例,0~3分6例,优良率84.2%.结论:"球探技术"是一种简便有效的术中控制TAD的技术。

Spherical External Gravity Correction

In mountainous area, gravity survey external corrections, including terrain and Bouguer corrections, are the prerequisites for gravity data processing and interpretation. This paper presents a suite of techniques for spherical terrain and slab corrections for a finite spherical shell based on the analysis of conventional external corrections and deduces an equation for spherical terrain correction. The processing of gravity data acquired in the ZJJ area, South China shows that this technique significantly improves the accuracy of terrain corrections, and the quality of the data reaches or approaches the data acquired on plains.

Automatic Change Detection of Geo-spatial Data from Imagery

The problems and difficulty of current change detection techniques are presented. Then, according to whether image registration is done before change detection algorithms, the authors classify the change detection into two categories:the change detection after image registration and the change detection simultaneous with image registration. For the former, four topics including the change detection between new image and old image, the change detection between new image and old map, the change detection between new image/old image and old map, and the change detection between new multi-source images and old map/image are introduced. For the latter, three categories, i.e. the change detection between old DEM, DOM and new non-rectification image, the change detection between old DLG, DRG and new non-rectification image, and the 3D change detection between old 4D products and new multi-overlapped photos, are discussed.

Stratospheric balloon-based dropsonde technology:Development and preliminary assessment over the Tibetan Plateau

To complement the atmospheric profile measurements under complex geographical environments and extreme weather conditions,a stratospheric balloon-based dropsonde technology,which is carried by a stratospheric balloon platform from the Earth's surface to the upper troposphere and lower stratosphere(UTLS)to release the dropsonde for measurements,is independently developed and preliminarily assessed over the Tibetan Plateau(TP)in this study.The dropsonde system is mainly composed of the dropsonde chamber,dropsonde with a parachute,data receiving and communication antennas,dropsonde-releasing device,and GPS(Global Positioning System)modules.The dropsonde measurements can be sent in real time through satellite communication links and by radio signals to a data receiver at the ground control center for storage and processing.A total of eight dropsondes aboard the stratospheric balloon were successfully released during the TP campaign in 2020.A preliminary assessment was conducted based on a case comparison between the dropsonde and radiosonde measurements,which indicated that the dropsonde technology we developed can generally provide reasonable atmospheric profiles.However,further efforts are still required to improve the detection performance of the dropsonde sensors after long-term locating in the UTLS and to assess the accuracy and precision of the detection technology more carefully.

Detection of Hazard Zones over Abandoned Mines of Albania through Geophysical Methods

This study consists to the detection of cavities that could be present over abandoned mines of Albania with the use of SP （self potential） and ERT （electrical resistance tomography）. In general, natural and artificial cavities represent an important investigation target in geotechnical, environmental and scientific studies. These studies could be engineering, archaeological or speleological. For the detection and localization of such cavities during the last 20 years, several geophysical studies have been used worldwide. In this field study, several geophysical methods could be used such as electrical, electromagnetic, gravimetric and seismic ones. Now days, the ground penetrating radar technique and ERT are widely used. Depending on geological formation conditions every used method is more or less effective. As a result of actual conditions of works on ore mines, the dynamic regime of the surroundings areas has undergone changes creating superficial cavities and funnels and as consequence the geological risk to the community is present. The detection of cavities is a challenge for geophysicists and in these cases the ambiguity on interpretation of geophysical data has to be solved properly. The simultaneous application of different geophysical methods and monitoring in time are necessary in order that the field data interpretation could be significant. Geophysical investigations were carried out as tests over galleries of ore mines of Albania. In this study, we present the SP and ERT results in two sites, in Dhrovjan and Perrenjas region. The effectiveness of the used geophysical methods was present.

Technological advancements and promotion roles of Chang'e-3 lunar probe mission

The mission objective of Chang’e-3 lunar probe is to achieve our first soft-landing and roving exploration on celestial bodies beyond Earth.On the basis of analyzing technological characteristics in the probe development,key technology breakthroughs and technological promoting roles of Chang’e-3 are both described.

An overview of the mission and technical characteristics of Change'4 Lunar Probe

Change＇4 Lunar Probe will softly land on the farside of the Moon for the first time of all mankind and carry out in-situ and rovering exploration. In this paper, the scientific significance and engineering difficulties of Change＇4 are introduced and the probe＇s general design, including the aspects of landing site selection, relay communication, trajectory design of relay satellite is explained. Besides, four key technologies, namely safe landing strategy on complex terrain, orbit design and control of libration point 2, relay communication on L2, radioisotope thermoelectric generator （RTG） and electric-thermal utilization, as well as how to realize them are also discussed. Finally the prospect of the prominent technological breakthrough of Change＇4 is described.

Technical advancements and significance of circumlunar return and reentry spacecraft

As one of the vital steps in the 3rd phase of China＇s lunar exploration program （CLEP）, the circumlunar return and reentry spacecraft, developed by China Academy of Space Technology （CAST）, is used to demonstrate the key technologies of by- per-speed return and reentry spacecraft. The system configuration and flight process are presented in this paper, as well as the analysis of mission characteristics, the key technologies and the technical advancement during the R＆D progress. The significance of circumlunar return and reentry spacecraft is given at the end.