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751.
This paper describes a case of pseudomosaic centric fission of chromosome 4 detected in amniotic fluid cell culture. The pregnancy went to term and the newborn had a normal chromosomal constitution. 相似文献
752.
关于建立地震灾害指标体系的研究:地震灾情的综合信息系统 总被引:2,自引:0,他引:2
建立地震灾害指杯体系,对全面、系统地反映灾情是十分重要的。本文对地震灾害指标和指标体系的定义及指标的类型、建立指标体系的基本原则及其结构、功能等进行了论述。 相似文献
753.
煤矿安全目标管理成果评价的模型与方法 总被引:1,自引:0,他引:1
在简要介绍煤矿安全目标管理方法和目标体系的基础上,提出了确定安全目标管理综合目标值的GM(1,N)- SMCO模型,用于对目标成果进行评价,并给出了某煤矿安全目标管理成果评价的应用实例 相似文献
754.
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756.
Stability of alpine timberline ecotone on Taibai Mountain,China 总被引:3,自引:0,他引:3
--Landscape
boundaries are always indicated by thevegetation boundaries. As an ecotone between closed
forest andtreeline, alpine timberline may respond to global climate changessensitively.
The stability of timberline and treeline depend notonly on climate change, but also on the
interaction of both sidesof the ecosystems. Three natural boundaries existing in
thetimberline transitional zone are recognized (1) timberline (upperlimit of closed
forest zone); (2) treeline (upper limit of treeislands zone); (3) tree-species line (upper
limit of individualtree growth). Paleobotanical and sedimentary evidences suggest
thatthere were several times of climate fluctuation during the Holoceneperiod in this
area. The timberline of Taibai Mountain must havemoved for four times on the millennium
scale. Being a stochasticoscillation boundary, treeline appears in a semi-stable
conditionon the century scale. The tree-species line is even more unstable,which appears
in an unstable status on the decades scale. Thecomparison of the stability within several
landscape boundaries,shed light on the sensibility of these communities to
variousperturbation and environmental heterogeneity, i.e., herb community is the most
sensitive one, which is followed by shrubs, and forestis the most stable one. Trees and
shrubs can adapt to rocky andpoor soils. On the contrary, alpine herbs are able to adapt
towetter and cooler soils. Finally, under a scenario of a temperatureof 1.5-4.5℃
increase, the present timberline will be relativelystable but treeline and tree-species
line will move upward. 相似文献
757.
EnvironmentalSciences,Beijing100012,China)Abstract:AstudyonlandfillgasemissioninQingdao,Chinawascarriedout.Theresultsshowedth... 相似文献
758.
759.
介绍了球团坚炉的烟尘排放特性,分析研究了影响静电除尘器工作性能的主要因素,总结了静电除尘改造工程中技术改进经验和运行管理所取得的经验。 相似文献
760.
C. Rosatelli F. Schettini G. Monni T. Tuveri M. T. Scalas A. Di Tucci G. B. Leoni Professor A. Cao 《黑龙江环境通报》1988,8(5):393-397
This report describes a couple at risk for β thalassaemia in which one spouse was heterozygous for classical high Hb A2 β-thalassaemia while the other had the compound heterozygous state for β+-thalassaemia and a β-chain variant. This variant comigrates on carboxymethyl-cellulose columns (CMC) with γ-chains, indicating that globin separation on CMC columns could not have been used for fetal diagnosis. The β-chain variant migrates separately from the other globin chains on HPLC and the respective abnormal haemoglobin can be separated by isoelectrofocusing. Oligonucleotide hybridization showed that both parents were carriers of the β+ IVS-1, nt 6 mutation. Prenatal diagnosis was successfully accomplished by oligo-nucleotide analysis on trophoblast DNA. This case indicates that an Antenatal Service should have alternative methods to CMC columns so as to carry out prenatal diagnosis of β-thalassaemia in uncommon cases. 相似文献