悬浮颗粒物对黄河铜的生物有效性影响的研究

利用t检验分析了悬浮颗粒物对黄河水体中铜的生物有效性的影响.结果表明,虽然过滤后水样的EC50比未过滤水样的EC50高,但是过滤前后24h-EC50和48h-EC50在统计学上没有显著差异;而过滤前后72h-EC50和96h-EC50存在显著差异.通过分析,认为造成这种现象的原因有两个:(1)未过滤的水样泥沙含量阻碍了藻类的光合作用;(2)试验过程中水样的理化性质发生改变,导致颗粒物中吸附的铜再次发生了解吸现象。     

强化混凝去除黄浦江水有机物的试验研究

强化混凝去除有机物的效果与水源的分子量分布特性有着密切的关系.由于黄浦江水中低分子量的溶解性有机物占多数,因此,强化混凝处理有机物效果有限.对于＜1k分子量区间的有机物.增加混凝剂投量可有效去除紫外吸光值(UV254),但去除溶解性有机碳(DOC)的效果很差.尽管增加混凝剂投量和降低pH都能有效地去除有机物,但决定强化混凝效果的主要因素是pH,去除黄浦江水有机物的最佳pH范围为6～5.     

沈阳市大气污染防治对策

本文根据沈阳市的大气污染现状，分析了大气污染形成的原因和特点及影响大气环境质量的主要因素，确定了大气环境质量目标。并提出了近期和２０００年的大气污染防治对策．     

Effectiveness evaluation of water-sprinkling in controlling urban fugitive road dust based on TRAKER method: A case study in Baoding, China

Fugitive road dust (FRD) contributes a great deal to urban rainwater and air pollution and is commonly controlled by water-sprinkling in most Chinese cities. However, there is a lack of information on its effectiveness. We used the Testing Re-entrained Aerosol Kinetic Emissions from Roads (TRAKER) method to monitor different types of roads in Baoding city before and within 1 hr after water-sprinkling and obtained the road dirtiness index (a) and PM concentration in the road environment ($T_{\mathrm{T}}^{*}$), to evaluate the removal efficiency for PM deposited on the road surface (${\eta }_a$) and the reduction efficiency for the PM concentration in the road environment (${\eta }_{\text{PM}}$). The results give that the ${\eta }_a$ for three types of roads is ranked: branch road (87%-–100%) > major arterial road (80%-83%) > minor arterial road (68%-77%), and the ${\eta }_{\text{PM}}$ ranked: minor arterial road (70%) > branch road (46%-58%) > major arterial road (37%-53%). The ${\eta }_a$ and ${\eta }_{\text{PM}}$ varied non-linearly with time and presented a quadratic curve. The average effective control time (${\eta }_{\mathit{a}}$> 0) was 62 min on the major and minor arterial roads, and much longer than 1 hr on branch roads. The ${\eta }_{\text{PM}}$ values diminished completely by 72 min on average from the end of sprinkling for the three types of roads. Water-sprinkling can remove PM₁₀ particles from the road surface and reduce their concentration in the road environment more thoroughly than PM_2.5. Our findings could be helpful for controlling urban FRD emissions more efficiently and precisely.     

Prenatal diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency by steroid analysis in the amniotic fluid of mid-pregnancy: Comparison with HLA typing in 17 pregnancies at risk for CAH

Amniotic fluid (AF) levels of 17-hydroxyprogesterone (17OHP) and testosterone (T) were determined at 16–17 weeks in 17 pregnancies at risk for CAH and results compared to 75 normal controls. The fetus was predicted to be unaffected in 12 cases on the findings of normal AF levels of both 17OHP and T and the latter allowed a correct prediction of fetal sex in all instances. HLA typing confirmed normality in 12 cases revealing 5 carriers, 5 homozygous normal and 2 indeterminate. Steroid levels of the 2 groups were similar. Three fetuses were predicted to be CAH affected on unambiguously high levels of 17OHP and T (in female only). HLA typing was in agreement, and the diagnosis was confirmed in 2 abortuses and a female newborn by physical and hormonal studies. In the last 2 cases AF levels of OHP and T were normal but HLA (A/B/C) genotypes were identical to the CAH affected siblings. Normal physical and hormonal findings in the 2 aborted fetuses would exclude the possibility of an in utero virilizing form of CAH. The discrepancy could be explained on the basis that the fetuses had an allelic form of 21-hydroxylase deficiency or on the basis of recombination (not fully tested). It is concluded that a fully informative prenatal diagnosis of CAH should not rely entirely on HLA typing but on hormonal studies.     

Prenatal diagnosis of gastrointestinal obstruction: A correlation between prenatal ultrasonic findings and postnatal operative findings

The impact of prenatal sonographic diagnosis of oesophageal and gastrointestinal obstructions has been analysed over a 10-year period. Three groups of patients were evaluated. The first group consisted of 46 newborns with abnormal prenatal sonogratns, 41 of which were confirmed to have intestinal obstruction postnatally. The second group consisted of 17 neonates with normal prenatal sonograms who had intestinal obstruction postnatally. The third group included 56 newborns who did not undergo a prenatal sonogram but who had intestinal obstruction confirmed at surgery. Polyhydramnios without the appearance of a stomach on ultrasound was diagnostic of pure oesophageal atresia. Polyhydramnios with intestinal dilation was diagnostic of intestinal obstruction. Although surgery was performed earlier in the infants diagnosed prenatally with ultrasound, mortality was no less than in the group that did not undergo a prenatal sonogram, probably because of the high incidence of associated anomalies.     

预处理的铜绿假单胞菌对Cu2+的生物吸附研究

从电镀废水污泥中分离，纯化获一高抗铜菌株，经鉴定为铜绿假单胞菌（Pseudomonas aeruginosa)，采用不同浓度盐酸对铜绿假单胞菌进行预处理，同时考察了不同因素如溶液的pH，温度，摇床转速，接触反应时间对未处理菌和预处理的影响，结果表明，经0．1NHCl预处理的菌体具有最佳吸附效果，pH、摇床转速对菌体的吸附具有较显著影响，温度对菌体吸附影响不大。     

研究单位压边力值对板料成形性能的影响

主要介绍板料在拉深成形过程中单位压边力值对板料成形性能的影响。研究方法采用仿真技术 ,指出板料在成形过程中如按最初设定的单位压边力值进行成形 ,那么 ,板料成形过程中单位压边力值将逐渐增大 ,严重影响板料成形极限。如果采用控制板料在成形过程中压边圈下坯料的单位压边力值 ,将提高板料成形极限。其结论为生产现场提高板料成形性能和表面质量提供了一种可实施的方法。