[目的]探究山东省不同气候分区年降水量的时空特征,为该地区气候分析、防灾减灾提供更加区域性的参考依据。[方法]根据山东省95个国家地面气象观测站1991—2020年降水年值数据,首先对山东省年降水场进行气候分区,然后通过相关统计方法...[目的]探究山东省不同气候分区年降水量的时空特征,为该地区气候分析、防灾减灾提供更加区域性的参考依据。[方法]根据山东省95个国家地面气象观测站1991—2020年降水年值数据,首先对山东省年降水场进行气候分区,然后通过相关统计方法分析各分区降水的时空变化特征。[结果](1)山东省各降水模态降水偏少的年份更多,降水偏多的年份降水强度更大,年代际变化均较为明显,但各模态降水偏多偏少的年份分布及强度变化有所不同。(2)山东省年降水量大致由东南向西北递减,年降水场划分为东南沿海区(Ⅰ区)、西北平原区(Ⅱ区)和中部山地区(Ⅲ区)3个区域,各降水分区年降水均呈不显著增加趋势,趋势率各不相同,突变均不明显。(3)山东省各降水分区年降水量均具有较为明显的周期性特征,东南沿海区年降水场存在2个较为明显的能量中心,中心尺度均为2~3 a,未来变化具有强持续性;西北平原区年降水场存在3个较为明显的能量中心,中心尺度分别为5~7 a, 3 a和2~3 a,未来变化具有持续性;中部山地区年降水场存在2个较为明显的能量中心,中心尺度分别为2~3 a, 6 a,未来变化具有强持续性。[结论]山东省降水偏少的年份更多,降水偏多的年份降水强度更大,年降水场大致可分为3个分区,各分区年降水量均呈不显著增加趋势,均具有较为明显的周期性特征,且未来变化均具有持续性。展开更多
Background:After the implantation of toric intraocular lenses(tIOLs)significant postoperative tIOL rotation angles were measured occasionally.We investigated the rotational stability of eyes during standardized photog...Background:After the implantation of toric intraocular lenses(tIOLs)significant postoperative tIOL rotation angles were measured occasionally.We investigated the rotational stability of eyes during standardized photography and recommend two methods for an enhanced evaluation of tIOL rotation.Patients and Methods:1.The cyclororation of the eye was investigated using standard fundus photography.A sequence of two fundus photographic slides was taken in 550 phakic eyes of 275 consecutive patients with a time interval of at least 6 months.With characteristic markers on the fundus photograph,the axial orientation of the eyes was defined and the cyclorotation between the two slides of each eye was measured.2.Using bifocal photography(HRA II-Heidelberg Retina Angiograph),a sequence of anterior segment and fundus images was taken considering stable head position in 19 pairs of photographs of eyes with implanted tIOLs.The angle between reference fundus axis and tIOL axis was measured at both time stages(mean:after 3 months).The difference of the angle between bifocal-image samples was defined as the real tIOL rotation angle.3.Ten pairs of anterior segment photographs of eyes with a tIOL were investigated using the Axenfeld loop analysis.In each photograph,the angle between the axis connecting two Axenfeld loops and the tIOL axiswasmeasured.The difference of two angles of two photographs was defined as the rotational tIOL angle.Results:1.The mean absolute eye’ s rotation angle was 2.3± 1.7(range:0 to 11.5)in all 550 eyes.Only 9.1% of the eyes did not rotate.In 57.3% of the eyes a rotation of less than 3° and in 33.6% of more than or equal to 3 was detected.The eye’ s cyclorotation correlated(p < 0.04)with an age older than 39 years and higher astigmatism(> 1.5 D).Because of the significant amount of spontaneous globe rotation we developed the following enhanced methods to minimize measurement errors of tIOL rotation:2.Bifocal photography:Comparing the 19 HRA anterior segment images,the amount of mean tIOL rotation was 5.4± 4.8°(range:0-20.0°).Using the bifocal photography,the mean tIOL rotation was 1.9± 1.3°(range:0-5.0°).The overestimated rotation of the tIOL(only anterior segment tIOL comparison)correlated with higher amounts of the eye’ s cyclorotation(r=0.94;p=0.01)and higher corneal astigmatism(r=0.54;p=0.05).3.The simultaneous analysis of Axenfeld loops revealed significantly smaller amounts of tIOL rotation(2.3± 2.5° range:0-7.0°)in 10 pairs of anterior segment photographs in contrast to the single analysis of tIOL axis(5.5± 4.8° range:1-13.0° p=0.09).A reduction of up to 18.0° tIOL rotation measurement failure was possible in single cases by applying the bifocal photography or simultaneous Axenfeld loop analysis.Conclusions:Head inclination,head rotation,and incyclo-or excyclorotation of the eye may have a significant impact on the tIOL axis evaluation.Besides the bifocal photography the simultaneous Axenfeld loop analysis could be a promising alternative to the conventional axis evaluation of tIOLs.展开更多
文摘[目的]探究山东省不同气候分区年降水量的时空特征,为该地区气候分析、防灾减灾提供更加区域性的参考依据。[方法]根据山东省95个国家地面气象观测站1991—2020年降水年值数据,首先对山东省年降水场进行气候分区,然后通过相关统计方法分析各分区降水的时空变化特征。[结果](1)山东省各降水模态降水偏少的年份更多,降水偏多的年份降水强度更大,年代际变化均较为明显,但各模态降水偏多偏少的年份分布及强度变化有所不同。(2)山东省年降水量大致由东南向西北递减,年降水场划分为东南沿海区(Ⅰ区)、西北平原区(Ⅱ区)和中部山地区(Ⅲ区)3个区域,各降水分区年降水均呈不显著增加趋势,趋势率各不相同,突变均不明显。(3)山东省各降水分区年降水量均具有较为明显的周期性特征,东南沿海区年降水场存在2个较为明显的能量中心,中心尺度均为2~3 a,未来变化具有强持续性;西北平原区年降水场存在3个较为明显的能量中心,中心尺度分别为5~7 a, 3 a和2~3 a,未来变化具有持续性;中部山地区年降水场存在2个较为明显的能量中心,中心尺度分别为2~3 a, 6 a,未来变化具有强持续性。[结论]山东省降水偏少的年份更多,降水偏多的年份降水强度更大,年降水场大致可分为3个分区,各分区年降水量均呈不显著增加趋势,均具有较为明显的周期性特征,且未来变化均具有持续性。
文摘Background:After the implantation of toric intraocular lenses(tIOLs)significant postoperative tIOL rotation angles were measured occasionally.We investigated the rotational stability of eyes during standardized photography and recommend two methods for an enhanced evaluation of tIOL rotation.Patients and Methods:1.The cyclororation of the eye was investigated using standard fundus photography.A sequence of two fundus photographic slides was taken in 550 phakic eyes of 275 consecutive patients with a time interval of at least 6 months.With characteristic markers on the fundus photograph,the axial orientation of the eyes was defined and the cyclorotation between the two slides of each eye was measured.2.Using bifocal photography(HRA II-Heidelberg Retina Angiograph),a sequence of anterior segment and fundus images was taken considering stable head position in 19 pairs of photographs of eyes with implanted tIOLs.The angle between reference fundus axis and tIOL axis was measured at both time stages(mean:after 3 months).The difference of the angle between bifocal-image samples was defined as the real tIOL rotation angle.3.Ten pairs of anterior segment photographs of eyes with a tIOL were investigated using the Axenfeld loop analysis.In each photograph,the angle between the axis connecting two Axenfeld loops and the tIOL axiswasmeasured.The difference of two angles of two photographs was defined as the rotational tIOL angle.Results:1.The mean absolute eye’ s rotation angle was 2.3± 1.7(range:0 to 11.5)in all 550 eyes.Only 9.1% of the eyes did not rotate.In 57.3% of the eyes a rotation of less than 3° and in 33.6% of more than or equal to 3 was detected.The eye’ s cyclorotation correlated(p < 0.04)with an age older than 39 years and higher astigmatism(> 1.5 D).Because of the significant amount of spontaneous globe rotation we developed the following enhanced methods to minimize measurement errors of tIOL rotation:2.Bifocal photography:Comparing the 19 HRA anterior segment images,the amount of mean tIOL rotation was 5.4± 4.8°(range:0-20.0°).Using the bifocal photography,the mean tIOL rotation was 1.9± 1.3°(range:0-5.0°).The overestimated rotation of the tIOL(only anterior segment tIOL comparison)correlated with higher amounts of the eye’ s cyclorotation(r=0.94;p=0.01)and higher corneal astigmatism(r=0.54;p=0.05).3.The simultaneous analysis of Axenfeld loops revealed significantly smaller amounts of tIOL rotation(2.3± 2.5° range:0-7.0°)in 10 pairs of anterior segment photographs in contrast to the single analysis of tIOL axis(5.5± 4.8° range:1-13.0° p=0.09).A reduction of up to 18.0° tIOL rotation measurement failure was possible in single cases by applying the bifocal photography or simultaneous Axenfeld loop analysis.Conclusions:Head inclination,head rotation,and incyclo-or excyclorotation of the eye may have a significant impact on the tIOL axis evaluation.Besides the bifocal photography the simultaneous Axenfeld loop analysis could be a promising alternative to the conventional axis evaluation of tIOLs.
