直岗拉卡水电站工程生态环境的影响分析

直岗拉卡水电站地处青藏高原,是黄河上游第4个梯级电站,工程所处区域属生态环境十分敏感和脆弱的青藏高原。论文在阐述直岗拉卡水电站工程影响区生态环境基本特征的基础上,度量了该区域生物多样性及电站运行后对生态环境的影响程度,提出了相关对策。分析表明,直岗拉卡水电站工程在实施严格的环境保护措施后对生态环境的影响是可以接受的。     

糠醛废水处理工程的调试运行实例

本文就糠醛生产工艺与生产废水水质特点 ,采用中和———厌氧———好氧气浮处理技术 ,对工程试运行中的各个环节及处理问题的措施及小试过程效果的应用 ,作系统的介绍。     

次声实验系统及其声学性能分析

为了从环境保护和劳动卫生学的角度研究次声对人的影响 ,本研究基于亥姆霍兹谐振器的基本原理研制了一个次声试验系统。该系统由亥姆霍兹谐振器、电声驱动部分和测控分析部分组成 ,通过对该系统的声学性能进行测试和分析 ,确定了系统所能发出的次声频率和次声级范围 ,讨论了系统发出次声时所产生的高次谐波对系统性能的影响及系统的频响特性 ,检验了谐振腔内部次声场空间分布的均匀性 ,结果表明该系统的声学性能是令人满意的 ,能够满足研究次声及其对人影响的实验要求。     

野生动物资源保护管理的价值观

野生动物资源作为一种可更新资源,与人类生活密切相关。发展经济使生态环境受到很大破坏,并涉及野生动物的生存环境。阐述野生动物资源对人类社会的科学价值,引起人们对野生动物资源的重视,以便更好地保护和管理野生动物资源。     

Prenatal diagnosis for dystrophia myotonica using the polymerase chain reaction

The polymerase chain reaction has been used to detect an abundant class of short repeat DNA families of the form (dC-dA)n.(dG-dT)n, known as microsatellites. These units are found throughout the human genome and have been characterized for several loci including APOC2 on chromosome 19ql2-ql3.2. The locus APOC2 is linked to the gene for dystrophia myotonica and a microsatellite within this locus was used to derive polymorphisms in a family to predict the inheritance of the disease. Chorionic villus sampling (CVS) was performed at 151/2 weeks' gestation. Following DNA extraction from the CVS material and parental blood samples, microsatellite analysis was carried out by the polymerase chain reaction.     

Prenatal diagnosis of β-thalassaemia in Mediterranean populations by dot blot analysis with DNA amplification and allele specific oligonucleotide probes

In this study, we describe a simple strategy to detect β-thalassaemia mutations in prospective parents and to make prenatal diagnosis in pregnancies at risk in the Mediterranean population. Screening of prospective parents is carried out by dot blot analysis on enzymatically amplified DNA with a set of oligonucleotide probes complementary to the most common mutations in this population. Prenatal diagnosis is accomplished by the same procedure on enzymatically amplified amniocyte or trophoblast DNA. The main advantages of this procedure are the simplicity, sensitivity (0.05 μg of DNA), and rapidity (12–24 h). Further simplification is obtained by amplification of the DNA from crude amniotic cell lysate. The very low amount of fetal material necessary for this analysis eliminates the need to culture amniotic fluid cells and may decrease the fetal loss rate associated with trophoblast sampling. The number of specific DNA sequences obtained by the amplification procedure allowed us to use non-radioactive labelled oligonucleotide probes, which have several advantages compared to radioactive probes.     

Prenatal diagnosis of Opitz (BBB) syndrome in the second trimester by ultrasound detection of hypospadias and hypertelorism

Prenatal diagnosis in a kindred with the Opitz (BBB) syndrome is presented. The inheritance is consistent with either autosomal dominant inheritance with sex limited expression or X-linked inheritance. The abnormalities in the kindred consist of hypertelorism, hypospadias, ambiguous genitalia, urocolic fistula, imperforate anus, mental retardation, diaphragmatic hernia, and malrotation with volvulus. A male fetus at 19 weeks was found by ultrasound to have hypertelorism and hypospadias with a small phallus consistent with the syndrome. The diagnosis was confirmed by pathologic examination after pregnancy termination. This is the first report of prenatal diagnosis of Opitz syndrome by ultrasonographic demonstration of hypertelorism and hypospadias in the second trimester.     

Fetal urinary insulin-like growth factor I and binding protein 3 in bilateral obstructive uropathies

Fetal urinary concentrations of insulin-like growth factor I (UIGF-I) and binding protein 3 (UIGFBP-3) were determined in patients with prenatal diagnosis of bilateral obstructive uropathy. Patients were retrospectively assigned to three groups, on the basis of outcome: group 1, termination of pregnancies (n = 11) with sonographic evidence of severe oligohydramnios or renal dysplasia, confirmed at histological examination; group 2, patients (n = 10) with postnatal plasma creatinine > 50 μmol/1 at the age of 1 year (1 yr-pCreat); and group 3, patients (n = 16) with 1 yr-pCreat ≤ μmol/1. The results show a significant increase in UIGF-I and UIGFBP-3 in groups 1 (18 159 ± 9083 pg/ml; 2657 ± 669 ng/ml) and 2 (1574 ± 847 pg/ml; 176 ± 50 ng/ml) in comparison with group 3 (35 ± 6 pg/ml; 21 ± 2 ng/ml). UIGF-I and UIGFBP-3 were significantly correlated with postnatal plasma creatinine, and were both sensitive (90 per cent; 80 per cent) and specific (88 per cent; 88 per cent) for prediction of elevated 1 yr-pCreat (>50 μmol/1). Fetal urinary IGF-I and IGFBP-3 are increased in severe fetal bilateral obstructive uropathy, possibly reflecting tubular dysfunction or/and increased synthesis consequent upon fetal kidney injury. Their predictive value for postnatal renal function needs further assessment.     

环境思想史和环境科学历史发展

人类主体与环境客体的相分导致明确环境概念的产生。人类产生过“环境决定论”、“环境可能论”和“人类中心论”等环境思想。对日趋严重的环境问题的认识中产生“环境报复论”和“环境和谐论”等思想,推动了环境科学的诞生和发展。环境科学发展了“环境质量学说”,正将注意力转向社会与环境协调发展上。环境科学仍处于发展与完善之中。     

长江中下游成矿侵入岩的特征研究

长江中下游的侵入岩体，尤其是燕山期的侵入岩体面广量大．它们与区内铜、铁、金等矿产关系密切。本文通过对侵入岩体地质特征、岩石化学成分等对比研究后，总结出如下几个特点：1、侵入体主要形成时代为135-95Ma，自西向东有逐渐变新的趋势；2、与成矿有关者多数是复式岩体，与铜矿化有关的主要是燕山早期侵入岩，与铁矿化有关的则主要是燕山晚期侵入岩；3、多数岩体受到过中、下三叠统蒸发岩层（膏盐层）的同化混染；4、岩体含碱质高，在Na2O－SiO2关系图上显示出二者没有相关性；5、侵入体中的铜有可能提供部分铜矿床的物源；6、岩石化学成分上某些组分的对比研究表明，成铜矿与成铁矿岩体之间、成矿岩体和无矿岩体之间有一定程度的差异。