期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
基于线裁剪的自适应网络带宽分级传输图像的方法 被引量:3
1
作者 李灿林 孟凡佳 +2 位作者 吴庆岗 毕丽华 刘金华 《科学技术与工程》 北大核心 2019年第10期132-136,共5页
针对图像网络传输中传输图像数据量或时长与目标图像质量之间的矛盾问题,考虑图像在不同网络带宽下传输的时效性,通过基于内容敏感的线裁剪减少图像数据量,提出了一种自适应网络带宽分级传输图像的方法。首先对网络带宽进行分级;并根据... 针对图像网络传输中传输图像数据量或时长与目标图像质量之间的矛盾问题,考虑图像在不同网络带宽下传输的时效性,通过基于内容敏感的线裁剪减少图像数据量,提出了一种自适应网络带宽分级传输图像的方法。首先对网络带宽进行分级;并根据网络带宽对所传输的图像定义并实施不同程度的基于内容敏感的线裁剪;这里所采用的线裁剪在水平与垂直方向上交替同时进行。实验结果表明:所提出的基于内容敏感线裁剪的图像自适应网络带宽传输方法不仅很好地保留图像的主要特征,而且适应网络带宽减少了图像网络传输时的数据量;进而减少了图像网络传输时间,提高传输时效性,有利于图像的高效传输。 展开更多
关键词 线裁剪 网络带宽 分级传输 内容敏感
下载PDF
Syntheses and Liquid Crystal Properties of New Rare Earth Sandwich Type Heteropoly Compounds 被引量:2
2
作者 bi li-hua LIU Jing-hua +3 位作者 WANG En-bo HUANG Ru-dan YU Yong-zhang WU Ping-song 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1999年第4期364-366,共3页
关键词 SYNTHESES Rare earth Liquid crystal
下载PDF
Fetal echocardiographic screening in twins for congenital heart diseases 被引量:4
3
作者 LI Hui MENG Tao +4 位作者 SHANG Tao GUAN Yun-ping ZHOU Wei-wei YANG Guang bi li-hua 《Chinese Medical Journal》 SCIE CAS CSCD 2007年第16期1391-1394,共4页
Background Congenital heart disease (CHD) is the most common congenital disorder at birth. Yagel and colleagues's method of heart examination has been proved valuable in finding CHD prenatally in single pregnancies... Background Congenital heart disease (CHD) is the most common congenital disorder at birth. Yagel and colleagues's method of heart examination has been proved valuable in finding CHD prenatally in single pregnancies. The aim of this study was to analyze the frequency of CHD in twin pregnancies and the sensitivity of the method. Methods A total of 1103 pregnant women with twins were enrolled in this study, including 127 cases with high-risk for CHD. Five transverse ultrasound measurements were used for fetal heart examination, including the upper abdomen view, four-chamber view, five-chamber view, pulmonary artery bifurcation view, and three-vessel view. In the fetuses who were diagnosed with CHD and whose parents requested termination of the pregnancy, autopsy of the fetal heart was performed after an abortion, and a blood sample was collected from the heart for chromosome evaluation. In the other fetuses, a close follow-up was conducted by echocardiography within one year after birth. Results Antenatally, CHD was found in 12 twins, of which 4 were from the high-risk group (3.15%), and 8 from the low-risk group (0.82%). In 2 pairs of the twins, the two fetuses had a same kind of CHD (one pair had tetralogy of Fallot (TOF), another pair had rhabdomyoma). Another pair had different types of anomaly (one fetus had TOF, and the other duodenal atresia with a normal heart). Termination of pregnancy was performed in these three pairs and the autopsy of the fetal heart confirmed the ultrasound findings. In the other 9 pairs, CHD was detected in one fetus, and a normal heart in the others. In the cases who received chromosome evaluation, 2 had abnormal chromosomes. During the follow-up after birth, heart examinations confirmed the prenatal diagnosis in 7 of the 9. The diagnosis of CHD was missed antenatally in 2 pairs of twins. In both the cases, one fetus was normal, and the other was confirmed as having CHD after birth (small ventricle septum defect in one, and persistent open ductus arteriosus in the other). Thus, the total frequency of CHD was 16 (7.3/1000), which was similar to that in single pregnancies. The sensitivity of fetal echocardiography was 87.5% and the specificity was 100%. Conclusions The frequency of CHD is the same in twin as in single pregnancies. Systemic ultrasound scanning with five transverse views is effective in diagnosing fetal CHD in twin pregnancies. 展开更多
关键词 TWINS ultrasound heart MALFORMATIONS antenatal diagnosis ECHOCARDIOGRAPHY
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部