城市生活垃圾场垂直防渗技术应用与认识

为防止生活垃圾场渗滤液扩散 ,造成二次污染 ,本文着重论述了采用帷幕注浆进行垂直防渗的可行性 ,并结合工程实践 ,对生活垃圾场场址选择、帷幕注浆材料使用以及防渗工程布置作了分析和探讨。     

荧光光谱法鉴别海面溢油源的研究进展

本文以大量的研究成果介绍了荧光光谱技术在鉴别海面溢油源中的应用和进展。根据普通荧光光谱、同步扫描光谱、可变角同步扫描光谱和总荧光光谱等不同荧光光谱信息特等，论述了荧光光谱的三维特性及维特性及其在溢油鉴别中的应用。同时，结合低温荧光法、磷光光谱法、导数荧光光谱法等辅助方法和技术，介绍了国内外荧光光谱法鉴别海面溢油的新进展和新成果。     

废塑料的回收利用及降解塑料的生产现状

介绍了废塑料的再生利用，热分解回收低分子化合物和焚烧回收热能的技术，并对国内降解塑料的生产现状进行了评述。     

Cardiac blood flow studies in fetuses with haemoglobin bart's disease

Blood flow across the atrioventricular valves and outflow tracts was measured in 55 normal fetuses and 32 fetuses with haemoglobin (Hb) Bart's disease between 18 and 26 weeks of gestation. The mean velocities remained unchanged in both normal and affected fetuses over the gestations studied. The volume flow across both atrioventricular valves and outflow tracts increased as the gestation advanced in both normal and affected fetuses, but was significantly higher in affected than in normal fetuses. The same magnitude of increased flow was found in both hydropic and non-hydropic fetuses with Hb Bart's disease. These findings suggest that fetuses with severe and long-standing anaemia have a remarkable cardiac compensatory mechanism for the maintenance of tissue oxygenation. In response to anaemia and circulatory loading, the cardiac chambers and outflow tracts enlarge proportionately up to twice the normal values. Because of this response and the operation of the Frank-Starling mechanism, the heart is able to maintain a normal mean velocity of propulsion and the net output is increased to two to three times that in normal fetuses. Hydropic changes in these anaemic fetuses appear unrelated to cardiac failure as cardiac failure is not observed at the time that hydropic changes develop.     

中国医院污水处理现状及前景分析

医院污水具有空间污染、急性传染和潜伏性传染等特征,不有效处理会成为一条疫病扩散的重要途径,并严重污染环境.本文首先提出了中国医院污水的处理现状,找出与发达国家之间的差距,进而对中国医院污水处理的前景进行了分析,提出中国医院污水处理中应改善的几个方面.     

Evaluation of a prenatal screening procedure for β-thalassaemia carriers in a chinese populationbased on the mean corpuscular volume (MCV)

Haemoglobin A₂ (HbA₂) levels were determined on 25 β-thalassaemia carriers by the microcolumn method and were found to range from 4.5–7.2 per cent (mean 5.2±0.82 S.D.). The haemoglobin level (Hb), mean corpuscular volume (MCV), plasma ferritin and HbA₂ levels were measured on a further 299 cconsecutive Chinese pregnant women at a gestation of less than 24 weeks. 18 patients (6 per cent) had HbA₂ level greater than 4.5 per cent and were diagnosed to be β-thalassaemic carriers. It was observed that all these patients had a MCV below 75 fl. If this level is selected in a screening procedure based on measurement of MCV alone all β-thalassaemia carriers could be detected and 11 per cent of the population screened would require HbA₂ estimation. At a lower cut-off level of 70 fl, 8 per cent of the population screened wouid require HbA₂ measurement (a decrease of 27 per cent) but the detection rate will be lowered considerably (83 per cent). The high false positive rate at all cut-off levels of MCV was largely due to the prevalence of iron deficiency anaemia in the population. Estimation of plasma ferritin level in patients with low MCV will reduce this false positive rate, but there will be a considerable delay in diagnosis in patients with concomitant iron deficiency and β-thalassaemia. The presence of iron deficiency in β-thalassaemia carriers did not reduce their HbA₂ level below the diagnostic range in this study. Measurement of Hb level did not appear to be useful as a screening method since one third of the β-thalassaemia carriers had a Hb level over 11 g/dl. The validity of the MCV cut-off levels derived from the first part of the study was assessed in screening a larger population. 61 β-thalassaemia carriers (6 per cent) were detected out of 1166 patients screened. This incidence was not significantly different from the first part of the study. All these 61 patients had a MCV less than 75 ml. It was concluded that a two-step screening policy, based on MCV measurement followed by HbA₂ estimation when the MCV value is less than 75 fl, is suitable for our population. It is efficient, straight forward with excellent sensitivity and required less time and effort for both laboratory staff and clinicians.     

浅谈一元线性回归在清洁生产审核中的应用

回归分析法是分析相关因素相互关系的一种数理统计方法,这种方法通常应用在预测分析中,如在市场预测时的产品需求预测,而这种方法亦可用于企业清洁生产审核,通过建立一元回归方程,从而表明消耗-生产之间的关系,并更深入地对绩效进行简单的分析,本文就一元线性回归在企业清洁生产审核中的应用进行了简要论述.     

中国自然灾害和减灾对策(之五)——开拓"综合减灾"新理念

近年世界上自然灾害损失增长日益严重,联合国副秘书长杨·埃格兰向联合国第61次大会报告了《国际减灾战略的执行情况》,近年内115个国家因自然灾害有93 000人丧生,经济损失比前十年平均值高出2.6倍、水灾次数大约高出50%.     

南太湖沉积物磷的释放研究

南太湖沉积物磷的释放与沉积物有机质含量、上覆水的化学性质、沉积物－水系统的细菌总数及湖泊水动力对沉积物释磷影响最强烈、沉积物因有机物含量不同，导致总有机磷、总氮、有机硫、水溶性无机硫含量差异，明显影响着磷的释放。沉积物－水系统的细菌总数与沉积物的释磷量存在显著性相关，而某细菌数量与释磷量相关笥不显著。对有机质含量低的沉积物，上覆水的ＢＯＤ，ＮＨ２－Ｎ浓度越高，磷的释放量越大。     

推行清洁生产是防治污染的有效方法

概述了清洁生产的重要性，以大庆化工二厂为例，阐述了推行清洁生产收到的显著的经济和环境效益