关于长江产业带建设总体布局的初步思考

重点开发长江是90年代中国经济重大战略布署。将长江产业带建设成具有强大经济实力的国家一级经济轴线,宜采用分层次推进与中心辐射相结合的发展战略,以浦东开发和三峡建设为契机,加强基础产业,发展新兴产业和第三产业,优化产业结构,以能源和交通建设先行,改善基础设施。同时,要协调产业带建设与浦东开发、三峡工程建设的关系。     

长江三峡柑桔的冻害和热害（二）

本文从柑桔冻害和热害的危害因子和指标等级划分的研究和选取入手,着重探讨了长江三峡地区(湖北境内)两害显著的时空变化特征、差异与关联性及对柑桔生产的影响;揭示了80年代以来冬暖春热的重大气候变化是使两害向“两极分化”的根本原因;讨论了三峡水利工程对两害时空格局的可能调整及减灾原理;最后提出了可能的对策。     

Processes involved in uptake and release of nitrogen dioxide from soil and building stones into the atmosphere

Atmospheric NO₂ was taken up by samples of various soils and building stones. The NO₂ uptake rate constants were highest in soil samples taken during the summer months. However, the NO₂ uptake rate constants of the soils and building stones were not significantly correlated with any of the following variables: moisture, pH, ammonium, nitrite, or nitrate. NO₂ uptake by soil and stone was not abolished by autoclaving indicating a chemical uptake process. NO₂ uptake by acidic and air-dry soils and stones resulted in nearly stoichiometric reduction of NO₂ to NO. This reduction was enhanced by the addition of ferrous iron and was further enhanced by incubation under 1 ppmv SO₂. The results suggest that NO₂ reduction may be coupled to oxidation of ferrous to ferric iron which may be reduced again by atmospheric SO₂ thus regenerating the ferrous iron content of the soil or stone. Conversion of NO₂ to NO was not observed in neutral or/and moist soils and stones. NO₂ was also taken up by purified and sterilized quartz sand moistend with water. This uptake was enhanced by addition of humic material but not by addition of bacteria which both had been extracted from genuine soil. Under most conditions, only uptake but no release of NO₂ was observed. However, NO₂ was released in air-dry soils that were heated to 45–65°C, or in ammonium-fertilized soil or stone that was drying up at room temperature. Under the latter conditions mimicking field practice, the NO₂ release reached rates that were similar to the NO release rates.     

4种不同生境的蟹类金属硫蛋白cDNA的克隆与比较

利用Carcinus maenas金属硫蛋白氨基酸序列资料，用全简并引物从鳃组织总RNA中扩增并克隆了首个甲壳类金属硫蛋白cDNA片段序列，3'-RACE获得了其编码区全长cDNA。之后，用部分简并的引物扩增并克隆了其它3种国内常见蟹类的金属硫蛋白cDNA编码区全长序列。序列分析结果表明，几种蟹的金属硫蛋白cDNA序列存在差异，推知的氨基酸序列也不完全相同，比较不同蟹的cDNA和氨基酸序列数据不能证明不同生态环境对金属硫蛋白的分子进化起重要作用。图4表1参15     

Prenatal diagnosis of partial monosomy 18p(18p11.2→pter) and trisomy 21q(21q22.3→qter) with alobar holoprosencephaly and premaxillary agenesis

A prenatal diagnosis of partial monosomy 18p(18p11.2→pter) and trisomy 21q(21q22.3→qter) in a fetus with alobar holoprosencephaly (HPE) and premaxillary agenesis (PMA) but without the classical Down syndrome phenotype is reported. A 27-year-old primigravida woman was referred for genetic counselling at 21 weeks' gestation due to sonographic findings of craniofacial abnormalities. Level II ultrasonograms manifested alobar HPE and median orofacial cleft. Cytogenetic analysis and fluorescence in situ hybridization (FISH) on cells obtained from amniocentesis revealed partial monosomy 18p and a cryptic duplication of 21q,46,XY,der(18)t(18;21)(p11.2;q22.3), resulting from a maternal t(18;21) reciprocal translocation. The breakpoints were ascertained by molecular genetic analysis. The pregnancy was terminated. Autopsy showed alobar HPE with PMA, pituitary dysplasia, clinodactyly and classical 18p deletion phenotype but without the presence of major typical phenotypic features of Down syndrome. The phenotype of this antenatally diagnosed case is compared with those observed in six previously reported cases with monosomy 18p due to 18;21 translocation. The present study is the first report of concomitant deletion of HPE critical region of chromosome 18p11.3 and cryptic duplication of a small segment of distal chromosome 21q22.3 outside Down syndrome critical region. The present study shows that cytogenetic analyses are important in detecting chromosomal aberrations in pregnancies with prenatally detected craniofacial abnormalities, and adjunctive molecular investigations are useful in elucidating the genetic pathogenesis of dysmorphism. Copyright © 2001 John Wiley & Sons, Ltd.     

Population Ageing and Sustainable Development Research in China

According to the United Nations population projections, the population of the elderly is expected to roughly triple in China from 2000 to 2050, particularly when the generations who were born between the 1950s and 1970s move through the age structure, and also because people are living longer and fertility rates have fallen, population aging is expected to put pressure on government's fiscal balance through higher old-age security benefits and health-care expenditures. This work draws together the broad range of elements involved within a consistent framework, based on a computable dynamic general equilibrium model with an overlapping generation structure. Further analysis using model simulation illustrates that the alternative schemes for the benefit rate, retirement age and technological progress are likely to be beneficial, and that an obvious slow-down in the growth of living standards is likely to be avoided.     

论生态园林及其建设的基本原则

生态园林是城市绿地建设的新思维,也是生态学具体应用的实践.生态园林建设应遵循生态优先、物种多样性保护和重建、因地制宜、处理好种间关系、建立群落自维持机制、重视生态文化内涵等六要素.     

生态足迹影响因子的定量分析

人口的膨胀和人类工业化进程的加剧，使得人类向自然界获取越来越多的资源，同时向环境源源不断的输入废弃物，已经严重超过了自然生态系统的供给能力和环境容量，生态环境日益恶化，水土流失、草场退化、植被消亡、生物多样性锐减、全球变暖等情况已经严重到难以遏制的地步，危及到人类自身的生存。在和平与发展成为世界两大主题的今天，人们越来越关注可持续发展的问题。在现有资料的基础上，利用主成分分析方法，定量地讨论了中国各省（区市）1999年生态足迹大小与其影响因子间的关系。结果表明，生态足迹的大小是各省（区市）的大中型企业个数、全社会固定生产投资等众多因子共同作用的结果，其中总人口和GDP是生态足迹大小的主要影响因子，其因子载荷量分别达到了0.940和0.913。值得一提的是非农业人口与生态足迹的相关系数超过了农业人口，这说明由于消费模式和生活水平等的差异，非农业人口对生态足迹的影响大于农业人口对生态足迹的影响。在此基础上建立了生态足迹影响因子的多元线性回归模型，以期为生态足迹在进行区域可持续发展评价的方法上提供新的思路。     

Increased fetal nuchal fold leading to prenatal diagnosis of ring chromosome 15

We report on the prenatal diagnosis of ring chromosome 15 in a fetus with increased nuchal fold and intrauterine growth restriction (IUGR). A 27-year-old woman gravida 2, para 1 had normal maternal serum screen tests in the early second trimester of the index pregnancy. Fetal nuchal fold thickening up to 8 mm was incidentally found during the routine obstetric ultrasound scan at 20 weeks' gestation. Amniocentesis was undertaken and the fetal karyotype was found to be 46,XY,r(15) on cytogenetic study. Fluorescence in situ hybridization (FISH) using a telomeric probe of chromosome 15 demonstrated a terminal deletion on the q arm of the ring-shaped chromosome 15. This is the first report of a prenatally diagnosed case of ring chromosome 15. Moreover, nuchal fold thickness in the second trimester may have a role in its prenatal diagnosis. Copyright © 2001 John Wiley & Sons, Ltd.