A bow echo is a type of mesoscale convective phenomenon that often induces extreme weather and appears with strong reflectivity on radar images. A strong bow echo that developed from a supercell was observed over Fosh...A bow echo is a type of mesoscale convective phenomenon that often induces extreme weather and appears with strong reflectivity on radar images. A strong bow echo that developed from a supercell was observed over Foshan City in southern China on 17 April 2011. The intense gusty winds and showers caused huge losses of property and severely affected human lives. This paper presents an analysis of this strong meso- n-scale convective system based on Doppler radar observations. The isolated bow echo exhibited a horizontal scale of about 80 km in terms of reflectivity above 40 dBZ, and a life span of 8 hours. The system originated from the merging of a couple of weakly organized cells in a shear line, and developed into an arch shape as it moved through the shear zone. Sufficient surface moisture supply ensured the convective instability and development of the bow echo. The low-altitude winds retrieved from single Doppler radar observations showed an obvious rear-inflow jet along the notch area. Different from the conventional definition, no book- end anticyclone was observed throughout the life cycle. Very strong slantwise updrafts and downdrafts were recognizable from the retrieved winds, even though the spatial scale of the bow echo was small. Strong winds and induced damage on the surface are considered to have been caused by the mid-level rear-inflow jet and intense convective downdrafts.展开更多
Background: Post-menopausal bleeding is a warning sign that accounts for about 5% of all outpatient gynaecologic visits and is a common indication for referral to rapid access clinics because of the fear of underlying...Background: Post-menopausal bleeding is a warning sign that accounts for about 5% of all outpatient gynaecologic visits and is a common indication for referral to rapid access clinics because of the fear of underlying malignancy. Endometrial malignancies differ from other malignancies in that early symptomization is common, allowing early cure. Patients and Methods: During the study period, 100 women with post-menopausal bleeding having inclusion criteria were evaluated in Al Hussein University Hospital. For each patient full history, general, abdominal and pelvic examination was performed. Routine pre-operative investigations were done. Patients were divided into four groups: Group 1 included 29 patients with endometrial polyp. Group 2 included 34 patients with endometrial hyperplasia. Group 3 included 21 patients with atrophic endometrium. Group 4 included 16 patients with endometrial carcinoma. Results: As regards the predictive value of BMI, in the study there was a high statistical significance in comparison between the endometrial carcinoma group and all other benign groups. When discussing the predictive value of blood glucose level, in the study there was a high statistical significance in comparison between the endometrial carcinoma group and all other benign groups. It is worth to mention that the predictive value of endometrial thickness, in the study, was with high statistical significance in comparison between the endometrial carcinoma group and all other benign groups providing the highest specificity and sensitivity. At the last the predictive value of uterine artery velocimetry, in the study, was with high statistical significance in comparison between the endometrial carcinoma group and all other benign groups. Conclusion: BMI, blood glucose level, endometrial thickness and uterine artery velocimetry indices, improve the prediction of endometrial carcinoma in women with post-menopausal bleeding.展开更多
With Zunyi CINRAD/CD Doppler radar data and other data,a hail wind and heavy rainfall in short time occurred on July 10,2008 in northern Guizhou Province was analyzed in this study.The results showed that the system w...With Zunyi CINRAD/CD Doppler radar data and other data,a hail wind and heavy rainfall in short time occurred on July 10,2008 in northern Guizhou Province was analyzed in this study.The results showed that the system was affected by the southward of cold air pressure in a low-shear vortex zone.Echo monomer initially developed and arranged along the shear line,and there was hail weather in echo location with intense development.Before the hail shooting,the strongest echo value was 60-65 dBz.When the hail shooting,the low-elevation echo intensity sharply increased to 55-60 dBz with echo height of 11-15 km and VIL values>35 kg/m2,and its echo distribution showed band characteristics of vortex.When the vortex center moved to the original echo,echo intensity increased,resulting in a profound and lasting convergence of cyclones,and hail or strong wind occurred on the ground.Hail and strong short-term precipitation in towns of northern Renhuai might be related to the left inverted U-terrain.Echoes from Yongxing and Yuquan in Meitan,Xuekong and Xitou in Renhuai were the supercell echoes,and other regional hail shooting echoes were strong multi-monomer echoes.展开更多
It was difficult to probe the clear air echo by the general traditional radar for echo's weak intensity.Therefore,its investigation was less because of the restrictions of probe technique and data.In recent years,...It was difficult to probe the clear air echo by the general traditional radar for echo's weak intensity.Therefore,its investigation was less because of the restrictions of probe technique and data.In recent years,with the probe tools improving,more clear air echoes were probed,and the relative investigations were more and more.However,most investigations stayed in the theory at present,and the relative literatures about its application in the practical forecast work were few.For a new generation of Doppler radars' powers and sensitivities were all high,they were put into service successively in China.People could observe more and more the clear air atmospheric echoes in the daily business.Its Doppler radar velocity provided the important basis for daily short-term predication and had very important indication meaning for the nowcasting of seasons which were spring,summer and fall.It was important to forecast the precipitation,especially the abrupt rainstorm by using the symptom of clear air echo which was probed by the new generation of Doppler radar products.Therefore,the advances on clear air echo research at home and abroad were summarized simply.展开更多
[Objective] The aim was to summarize the characteristics of refelectivity factors of Doppler radar of the cold front cloud system. [Method] Judging from the characteristics of reflectivity factors, by dint of the new ...[Objective] The aim was to summarize the characteristics of refelectivity factors of Doppler radar of the cold front cloud system. [Method] Judging from the characteristics of reflectivity factors, by dint of the new generation weather radar in Harbin from 2002 to 2007, the features of the reflectivity factors of the cold front cloud system were summarized. [Result] The cloud formed by the cold front was in banded form in general. However, there was void in the cloud and its intensity was uneven. Most fast moving cold front was long and narrow banded echo and basically the radial velocity turned from northwest wind to southwest. With the changes of month, the feature of the reflective rate also changed. In winter, the cold front cloud was in layer form. The feature of the reflectivity factors was weak and in large area. However, the structure was loose and there was space in the echo. Among them, there were several strong echoes. Strong convection cell echo formed in the two sides of the cold front, and it moved with the entire cloud belt. When the dry cold front moved, regional strong convective current formed, mainly by convective cloud and small echo area. Generally, the changes of the wind direction can not be expounded from the radial velocity. However, the intensity of the convection cell was distinct, 'three-body scattering', 'side lobe echo', and 'weak echo', as well as features of super convection cell. [Conclusion] The study provided positive role for the application of Doppler radar in the surveillance of weather in Heilongjiang Province.展开更多
基金supported by the National Basic Research Program of China(Grant No.2012CB417204)National Natural Science Foundation of China projects(Grant Nos.41175095 and 40875065)partly by the National Key Technology R&D Program(Grant No.2012BAC22B01)
文摘A bow echo is a type of mesoscale convective phenomenon that often induces extreme weather and appears with strong reflectivity on radar images. A strong bow echo that developed from a supercell was observed over Foshan City in southern China on 17 April 2011. The intense gusty winds and showers caused huge losses of property and severely affected human lives. This paper presents an analysis of this strong meso- n-scale convective system based on Doppler radar observations. The isolated bow echo exhibited a horizontal scale of about 80 km in terms of reflectivity above 40 dBZ, and a life span of 8 hours. The system originated from the merging of a couple of weakly organized cells in a shear line, and developed into an arch shape as it moved through the shear zone. Sufficient surface moisture supply ensured the convective instability and development of the bow echo. The low-altitude winds retrieved from single Doppler radar observations showed an obvious rear-inflow jet along the notch area. Different from the conventional definition, no book- end anticyclone was observed throughout the life cycle. Very strong slantwise updrafts and downdrafts were recognizable from the retrieved winds, even though the spatial scale of the bow echo was small. Strong winds and induced damage on the surface are considered to have been caused by the mid-level rear-inflow jet and intense convective downdrafts.
文摘Background: Post-menopausal bleeding is a warning sign that accounts for about 5% of all outpatient gynaecologic visits and is a common indication for referral to rapid access clinics because of the fear of underlying malignancy. Endometrial malignancies differ from other malignancies in that early symptomization is common, allowing early cure. Patients and Methods: During the study period, 100 women with post-menopausal bleeding having inclusion criteria were evaluated in Al Hussein University Hospital. For each patient full history, general, abdominal and pelvic examination was performed. Routine pre-operative investigations were done. Patients were divided into four groups: Group 1 included 29 patients with endometrial polyp. Group 2 included 34 patients with endometrial hyperplasia. Group 3 included 21 patients with atrophic endometrium. Group 4 included 16 patients with endometrial carcinoma. Results: As regards the predictive value of BMI, in the study there was a high statistical significance in comparison between the endometrial carcinoma group and all other benign groups. When discussing the predictive value of blood glucose level, in the study there was a high statistical significance in comparison between the endometrial carcinoma group and all other benign groups. It is worth to mention that the predictive value of endometrial thickness, in the study, was with high statistical significance in comparison between the endometrial carcinoma group and all other benign groups providing the highest specificity and sensitivity. At the last the predictive value of uterine artery velocimetry, in the study, was with high statistical significance in comparison between the endometrial carcinoma group and all other benign groups. Conclusion: BMI, blood glucose level, endometrial thickness and uterine artery velocimetry indices, improve the prediction of endometrial carcinoma in women with post-menopausal bleeding.
文摘With Zunyi CINRAD/CD Doppler radar data and other data,a hail wind and heavy rainfall in short time occurred on July 10,2008 in northern Guizhou Province was analyzed in this study.The results showed that the system was affected by the southward of cold air pressure in a low-shear vortex zone.Echo monomer initially developed and arranged along the shear line,and there was hail weather in echo location with intense development.Before the hail shooting,the strongest echo value was 60-65 dBz.When the hail shooting,the low-elevation echo intensity sharply increased to 55-60 dBz with echo height of 11-15 km and VIL values>35 kg/m2,and its echo distribution showed band characteristics of vortex.When the vortex center moved to the original echo,echo intensity increased,resulting in a profound and lasting convergence of cyclones,and hail or strong wind occurred on the ground.Hail and strong short-term precipitation in towns of northern Renhuai might be related to the left inverted U-terrain.Echoes from Yongxing and Yuquan in Meitan,Xuekong and Xitou in Renhuai were the supercell echoes,and other regional hail shooting echoes were strong multi-monomer echoes.
文摘It was difficult to probe the clear air echo by the general traditional radar for echo's weak intensity.Therefore,its investigation was less because of the restrictions of probe technique and data.In recent years,with the probe tools improving,more clear air echoes were probed,and the relative investigations were more and more.However,most investigations stayed in the theory at present,and the relative literatures about its application in the practical forecast work were few.For a new generation of Doppler radars' powers and sensitivities were all high,they were put into service successively in China.People could observe more and more the clear air atmospheric echoes in the daily business.Its Doppler radar velocity provided the important basis for daily short-term predication and had very important indication meaning for the nowcasting of seasons which were spring,summer and fall.It was important to forecast the precipitation,especially the abrupt rainstorm by using the symptom of clear air echo which was probed by the new generation of Doppler radar products.Therefore,the advances on clear air echo research at home and abroad were summarized simply.
文摘[Objective] The aim was to summarize the characteristics of refelectivity factors of Doppler radar of the cold front cloud system. [Method] Judging from the characteristics of reflectivity factors, by dint of the new generation weather radar in Harbin from 2002 to 2007, the features of the reflectivity factors of the cold front cloud system were summarized. [Result] The cloud formed by the cold front was in banded form in general. However, there was void in the cloud and its intensity was uneven. Most fast moving cold front was long and narrow banded echo and basically the radial velocity turned from northwest wind to southwest. With the changes of month, the feature of the reflective rate also changed. In winter, the cold front cloud was in layer form. The feature of the reflectivity factors was weak and in large area. However, the structure was loose and there was space in the echo. Among them, there were several strong echoes. Strong convection cell echo formed in the two sides of the cold front, and it moved with the entire cloud belt. When the dry cold front moved, regional strong convective current formed, mainly by convective cloud and small echo area. Generally, the changes of the wind direction can not be expounded from the radial velocity. However, the intensity of the convection cell was distinct, 'three-body scattering', 'side lobe echo', and 'weak echo', as well as features of super convection cell. [Conclusion] The study provided positive role for the application of Doppler radar in the surveillance of weather in Heilongjiang Province.
