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本文根据组合模式原理提出了一种用小震调制比(rm)异常区出现高频次的空间异常图,进行强地震中短期预报的方法,简称rs法。该方法在预报强震地点和时间上可望取得较好效果。本文在介绍该方法的基础上,应用该法对3次7级以上大震进行了回顾性检验。  相似文献   
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利用我国160个台站1951—2010年逐月降水观测资料,分析了我国1990—2009年夏季(6—8月)降水的变化特征,对其代表性雨型进行了分类,重点分析了1990年代和2000年代主要多雨带的变化特征。此外还分析了1990年代和2000年代的北半球500 hPa大尺度环流背景和气温及海温背景的差异,从而探讨了夏季降水...  相似文献   
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We report on the prenatal diagnosis and ultrasonographic findings of a second-trimester fetus with jumping translocation involving chromosome 22. A 28-year-old gravida 2, partus 1, Turkish woman was referred for genetic counselling and ultrasonographic examination at 18 weeks' gestation because of a high risk of trisomy 21 in triple test. Prenatal ultrasonography showed tetralogy of Fallot with a diverticular dilatation of the pulmonary artery, flattened brow, complete absence of the right upper limb, hypospadias, oligodactyly (three digits) in left hand and in both feet, and hyperechogenic abdominal foci. Amniocentesis revealed a karyotype of 46,XY[4]/46,XY,−8,+ der(8),t(8;22)(q24.3;q11.21)[2]/45, XY,−22,−8,+ der(8)t(8;22)(q24.3;q11.21)[22]/45,XY,−22,−5,+ der(5)t(5;22)(q35.3;q11.21)[44]. A C-banding and FISH study with a specific centromeric probe (D14Z1/D22Z1) for chromosome 22 was made. In our case, partial monosomy for the regions 22q11.21→22pter, 8q24.3→8qter and 5q35.3→5qter may partially explain the fetal malformations. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
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Studies on the vegetation and soil complexes in areas of the Kolyma River basin disturbed by mining, in the northeast of the Chukchi Peninsula, have been performed to reveal trends in natural restorative processes in posttechnogenic landscapes. Data on the flora, phytomass stock, chemical composition of plants pioneering in the overgrowing of disturbed areas, and physicochemical properties of soils and technogenic eluvia have been obtained. The results have shown that plant cover restoration in disturbed areas depends primarily on the type (genesis) of technogenic substrates, the content of fine earth in the surface layer, and the distance from natural plant complexes that serve as a source of seeds coming to the disturbed area.  相似文献   
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Ultrasound scans in the mid trimester of pregnancy are now a routine part of antenatal care in most European countries. With the assistance of Registries of Congenital Anomalies a study was undertaken in Europe. The objective of the study was to evaluate prenatal detection of congenital heart defects (CHD) by routine ultrasonographic examination of the fetus. All congenital malformations suspected prenatally and all congenital malformations, including chromosome anomalies, confirmed at birth were identified from the Congenital Malformation Registers, including 20 registers from the following European countries: Austria, Croatia, Denmark, France, Germany, Italy, Lithuania, Spain, Switzerland, The Netherlands, UK and Ukrainia. These registries follow the same methodology. The study period was 1996–1998, 709 030 births were covered, and 8126 cases with congenital malformations were registered. If more than one cardiac malformation was present the case was coded as complex cardiac malformation. CHD were subdivided into ‘isolated’ when only a cardiac malformation was present and ‘associated’ when at least one other major extra cardiac malformation was present. The associated CHD were subdivided into chromosomal, syndromic non-chromosomal and multiple. The study comprised 761 associated CHD including 282 cases with multiple malformations, 375 cases with chromosomal anomalies and 104 cases with non-chromosomal syndromes. The proportion of prenatal diagnosis of associated CHD varied in relation to the ultrasound screening policies from 17.9% in countries without routine screening (The Netherlands and Denmark) to 46.0% in countries with only one routine fetal scan and 55.6% in countries with two or three routine fetal scans. The prenatal detection rate of chromosomal anomalies was 40.3% (151/375 cases). This rate for recognized syndromes and multiply malformed with CHD was 51.9% (54/104 cases) and 48.6% (137/282 cases), respectively; 150/229 Down syndrome (65.8%) were livebirths. Concerning the syndromic cases, the detection rate of deletion 22q11, situs anomalies and VATER association was 44.4%, 64.7% and 46.6%, respectively. In conclusion, the present study shows large regional variations in the prenatal detection rate of CHD with the highest rates in European regions with three screening scans. Prenatal diagnosis of CHD is significantly higher if associated malformations are present. Cardiac defects affecting the size of the ventricles have the highest detection rate. Mean gestational age at discovery was 20–24 weeks for the majority of associated cardiac defects. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
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Jarcho–Levin syndrome (JLS) or spondylothoracic dysotosis causes early newborn death from respiratory insufficiency. Prenatal diagnosis is possible using fetal ultrasound, but requires a high level of suspicion and definitive diagnosis may be delayed well into the second trimester. We present a case in which a combination of three-dimensional ultrasound and measurement of nuchal translucency thickness allowed successful detection of recurrent JLS at 12 weeks' gestation. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
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