The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of G...The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of GIM products in data-sparse regions is of paramount importance.In this study,measurements from the Crustal Movement Observation Network of China(CMONOC)are leveraged to evaluate the suitability of IGS-GIM products over China region in 2013-2014.The indices of mean error(ME),root mean square error(RMSE),and normalized RMSE(NRMSE)are then utilized to quantify the accuracy of IGS-GIM products.Results revealed distinct local time and latitudinal dependencies in IGS-GIM errors,with substantially high errors at nighttime(NRMSE:39%)and above 40°latitude(NRMSE:49%).Seasonal differences also emerged,with larger equinoctial deviations(NRMSE:33.5%)compared with summer(20%).A preliminary analysis implied that the irregular assimilation of sparse IGS observations,compounded by China’s distinct geomagnetic topology,may manifest as error variations.These results suggest that modeling based solely on IGS-GIM observations engenders inadequate representations across China and that a thorough examination would proffer the necessary foundation for advancing regional total electron content(TEC)constructions.展开更多
The Global Navigation Satellite System （GNSS） is becoming important for monitoring the variations in the earth＇s ionosphere based on the total electron content （TEC） and iono- spheric electron density （IED）. Th...The Global Navigation Satellite System （GNSS） is becoming important for monitoring the variations in the earth＇s ionosphere based on the total electron content （TEC） and iono- spheric electron density （IED）. The Crustal Movement Observation Network of China （CMONOC）, which includes GNSS stations across China's Mainland, enables the continuous monitoring of the ionosphere over China as accurately as possible. A series of approaches for GNSS-based ionospheric remote sensing and software has been proposed and devel- oped by the Institute of Geodesy and Geophysics （IGG） in Wuhan. Related achievements include the retrieval of ionospheric observables from raw GNSS data, differential code biases estimations in satellites and receivers, models of local and regional ionospheric TEC, and algorithms of ionospheric tomography. Based on these achievements, a software for processing GNSS data to determine the variations in ionospheric TEC and IED over China has been designed and developed by IGG. This software has also been installed at the CMONOC data centers belonging to the China Earthquake Administration and China Meteorological Administration. This paper briefly introduces the related research achievements and indicates potential directions of future work.展开更多
A prediction method of strata movement in underground metal mines is put forward, in which fuzzy BP neural network is applied. The results show that there is a strong nonlinear relation between the selected factors an...A prediction method of strata movement in underground metal mines is put forward, in which fuzzy BP neural network is applied. The results show that there is a strong nonlinear relation between the selected factors and strata movement angle, the anticipant and the actual output results are very similar. It is proved that the numerical value of movement angle is correlated with the selected factors in theory. The scope of strata and surface movement due to mining can be predicted. This research provides a thought to study the movement scope of strata due to mining.展开更多
An observation network focusing on earthquakes wascompleted one year aheadof schedule and put into operationrecently. According to scientists, this135-million-yuan (U.S.$16.3million) project could also be usedfor geod...An observation network focusing on earthquakes wascompleted one year aheadof schedule and put into operationrecently. According to scientists, this135-million-yuan (U.S.$16.3million) project could also be usedfor geodetic surveying, ionosphereand sea-level observations,展开更多
GPS observation network is deployed in the central part of Ningxia, which is the juncture of the Alxa block, Ordos block and Qinghai-Xizang (Tibet) block. Using the data of five phases of repeated survey sine 1996, th...GPS observation network is deployed in the central part of Ningxia, which is the juncture of the Alxa block, Ordos block and Qinghai-Xizang (Tibet) block. Using the data of five phases of repeated survey sine 1996, the current state of crustal movement in the central part of Ningxia is analyzed. From the result, we can know the following. (1) In the period from Dec. 1996 to May 1999, the central part of Ningxia had the phenomenon of left-lateral movement about the west margin of Ordos (measuring station P2) and the Lingwu fault on the east of the Yinchuan basin displayed the mode of left-lateral reverse strike slip movement. In that region, the direction of the principal stress field was NNE-SSW (with an azimuth of 29.8?; the central part to the south of the measuring station P2 displaced eastward; the vertical deformation was obviously greater than the horizontal deformation in order of magnitude; the Yinchuan basin and Qinghai-Xizang (Tibet) block were in a state of rising; the measuring station P1 in the hinterland of Ordos showed a trend of subsiding year by year; and there may be a hidden fault to exist between the measuring points P3 and P4. (2) About one year before the occurrence of moderately strong earthquakes in the vicinity of the measuring region, deformation anomalies and abnormal changes of principal stress direction can be observed by the GPS measuring stations in that region; before moderately strong earthquakes near the measuring region and before strong earthquakes in adjacent regions, the simulated GPS deformation vector field ofthat region can betoken the approximate position of the coming earthquake. These results can be regarded as the eigenvalues of earthquake prediction for consideration.展开更多
目的系统评价上肢强化训练对脑瘫儿童上肢运动功能的效果。方法构建PICO架构,检索PubMed、Embase、Cochrane Library、Scopus、Web of Science、中国知网、中国生物医学文献数据库、维普和万方数据库,搜集关于上肢强化训练改善脑瘫儿童...目的系统评价上肢强化训练对脑瘫儿童上肢运动功能的效果。方法构建PICO架构,检索PubMed、Embase、Cochrane Library、Scopus、Web of Science、中国知网、中国生物医学文献数据库、维普和万方数据库,搜集关于上肢强化训练改善脑瘫儿童上肢运动功能的随机对照试验,检索时限均为2010年1月至2024年3月。按照Cochrane系统评价手册和物理治疗证据数据库量表对纳入文献进行质量评价,由2名研究者独立筛选文献、提取资料并评价纳入研究的偏倚风险后,采用RevMan 5.4和Stata 17.0进行网状Meta分析。结果共纳入27篇文献,包括1173例患者,涉及3种上肢强化训练。强制性运动疗法、改良强制性运动疗法和手-臂双侧强化训练均可提高辅助手功能评分与Peabody精细运动功能评分;强制性运动疗法和改良强制性运动疗法可提高上肢技能质量量表评分;手-臂双侧强化训练可提高儿童生活功能量表评分。在提高辅助手功能、上肢技能质量量表评分和Peabody精细运动功能评分方面,强制性运动疗法为最佳干预方式;在提高儿童生活功能量表评分方面,手-臂双侧强化训练为最佳干预方式。结论上肢强化训练可显著改善脑瘫儿童的上肢运动功能、精细运动功能和日常生活活动能力,强制性运动疗法在改善上肢运动功能和精细运动功能方面效果最好,手-臂双侧强化训练在提高日常生活活动能力方面疗效最佳。展开更多
目的:运用系统评价与网状meta分析方法比较综合正畸治疗中用于加速牙齿运动的各种干预措施的有效性。方法:通过检索PubMed、Willey Library、EBSCO、Web of Science和EMBASE数据库中检索关于不同干预措施对正畸牙齿移动加速效果影响的...目的:运用系统评价与网状meta分析方法比较综合正畸治疗中用于加速牙齿运动的各种干预措施的有效性。方法:通过检索PubMed、Willey Library、EBSCO、Web of Science和EMBASE数据库中检索关于不同干预措施对正畸牙齿移动加速效果影响的随机对照实验,筛选符合纳入标准文章后提取文献数据并评价纳入文献偏移风险,采用ADDIS 1.16.6和Stata 16.0软件进行网络Meta分析(NMA)。结果:按照尖牙移动的时间作结局指标进行讨论,分别为尖牙组持续时长1、2、3个月,把各个时间段的牙齿迁移数量当作连续性随机变量进行数据分析。最后一共纳入47篇随机对照实验,干预措施总共包含11种:光生物调节(PBMT)、富血小板血浆(PRP)、电磁(EF)、低强度激光(LLLT)、低强度脉冲超声波(LIPUS)、循环加载振动(LFV)、牙周膜牵张成骨/牙槽骨牵张成骨(DAD)、骨皮质切开术(corti)、压电环切术(Piezo)、微骨穿刺(MOPs)和传统治疗(OT)。根据最佳干预效果SUCRA概率排序,在正畸治疗持续1月时,PBMT(90.6%)、Piezo(87.4%)、MOPs(73.6%)为提高尖牙移动效率的排名前三的干预措施。在正畸治疗持续2月时,Corti(75.7%)、Piezo(69.6%)、LFV(58.9%)为提高尖牙移动效率的排名前三的干预措施。在正畸治疗持续3月时,Corti(73.3%)、LLLT(68.4%)、LFV(60.8%)为提高尖牙移动效率的排名前三的干预措施。结论:PBMT和Piezo在使用1个月时对于尖牙移动效率提高较明显,Corti和LFV在使用2个月和3个月对于尖牙移动效率有较好的效果。展开更多
基金the National Key R&D Program of China(Grant No.2022YFF0503702)the National Natural Science Foundation of China(Grant Nos.42074186,41831071,42004136,and 42274195)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20211036)the Specialized Research Fund for State Key Laboratories,and the University of Science and Technology of China Research Funds of the Double First-Class Initiative(Grant No.YD2080002013).
文摘The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of GIM products in data-sparse regions is of paramount importance.In this study,measurements from the Crustal Movement Observation Network of China(CMONOC)are leveraged to evaluate the suitability of IGS-GIM products over China region in 2013-2014.The indices of mean error(ME),root mean square error(RMSE),and normalized RMSE(NRMSE)are then utilized to quantify the accuracy of IGS-GIM products.Results revealed distinct local time and latitudinal dependencies in IGS-GIM errors,with substantially high errors at nighttime(NRMSE:39%)and above 40°latitude(NRMSE:49%).Seasonal differences also emerged,with larger equinoctial deviations(NRMSE:33.5%)compared with summer(20%).A preliminary analysis implied that the irregular assimilation of sparse IGS observations,compounded by China’s distinct geomagnetic topology,may manifest as error variations.These results suggest that modeling based solely on IGS-GIM observations engenders inadequate representations across China and that a thorough examination would proffer the necessary foundation for advancing regional total electron content(TEC)constructions.
基金partially funded by the Crustal Movement Observation Network of China(CMONOC)iGMAS,the National Basic Research Program of China(2012CB825604)+4 种基金China Natural Science Funds(41304034,41231064,41204031)China Scholarship Council,and CAS/SAFEA International Partnership Program for Creative Research Teams(KZZD-EW-TZ-05)Beijing Natural Science Funds(4144094)863programs(2012AA121803)the State Key Laboratory of Geodesy and Earth's Dynamics(SKLGED2014-3-1-E,SKLGED2014-3-7-E)
文摘The Global Navigation Satellite System （GNSS） is becoming important for monitoring the variations in the earth＇s ionosphere based on the total electron content （TEC） and iono- spheric electron density （IED）. The Crustal Movement Observation Network of China （CMONOC）, which includes GNSS stations across China's Mainland, enables the continuous monitoring of the ionosphere over China as accurately as possible. A series of approaches for GNSS-based ionospheric remote sensing and software has been proposed and devel- oped by the Institute of Geodesy and Geophysics （IGG） in Wuhan. Related achievements include the retrieval of ionospheric observables from raw GNSS data, differential code biases estimations in satellites and receivers, models of local and regional ionospheric TEC, and algorithms of ionospheric tomography. Based on these achievements, a software for processing GNSS data to determine the variations in ionospheric TEC and IED over China has been designed and developed by IGG. This software has also been installed at the CMONOC data centers belonging to the China Earthquake Administration and China Meteorological Administration. This paper briefly introduces the related research achievements and indicates potential directions of future work.
文摘A prediction method of strata movement in underground metal mines is put forward, in which fuzzy BP neural network is applied. The results show that there is a strong nonlinear relation between the selected factors and strata movement angle, the anticipant and the actual output results are very similar. It is proved that the numerical value of movement angle is correlated with the selected factors in theory. The scope of strata and surface movement due to mining can be predicted. This research provides a thought to study the movement scope of strata due to mining.
文摘An observation network focusing on earthquakes wascompleted one year aheadof schedule and put into operationrecently. According to scientists, this135-million-yuan (U.S.$16.3million) project could also be usedfor geodetic surveying, ionosphereand sea-level observations,
基金the Program of the Science and Technology Commission of Ningxia Hui Autonomous Region and Joint Foundation of Seismological Science(197043).
文摘GPS observation network is deployed in the central part of Ningxia, which is the juncture of the Alxa block, Ordos block and Qinghai-Xizang (Tibet) block. Using the data of five phases of repeated survey sine 1996, the current state of crustal movement in the central part of Ningxia is analyzed. From the result, we can know the following. (1) In the period from Dec. 1996 to May 1999, the central part of Ningxia had the phenomenon of left-lateral movement about the west margin of Ordos (measuring station P2) and the Lingwu fault on the east of the Yinchuan basin displayed the mode of left-lateral reverse strike slip movement. In that region, the direction of the principal stress field was NNE-SSW (with an azimuth of 29.8?; the central part to the south of the measuring station P2 displaced eastward; the vertical deformation was obviously greater than the horizontal deformation in order of magnitude; the Yinchuan basin and Qinghai-Xizang (Tibet) block were in a state of rising; the measuring station P1 in the hinterland of Ordos showed a trend of subsiding year by year; and there may be a hidden fault to exist between the measuring points P3 and P4. (2) About one year before the occurrence of moderately strong earthquakes in the vicinity of the measuring region, deformation anomalies and abnormal changes of principal stress direction can be observed by the GPS measuring stations in that region; before moderately strong earthquakes near the measuring region and before strong earthquakes in adjacent regions, the simulated GPS deformation vector field ofthat region can betoken the approximate position of the coming earthquake. These results can be regarded as the eigenvalues of earthquake prediction for consideration.
