自硬性玻璃基生物水泥的结构研究

利用X射线衍射和扫描电镜研究了玻璃基生物水泥在生理模拟液中羟基磷灰石（HAP）晶相的形成和长大，应用溶解－析晶理论，阐述了玻璃粉末与调和液及表面活性剂反应，形成HAP的动力学观点，实验结果表明，玻璃基生物水泥在调和液作用下，会形成HAP晶相，在生理模拟液中，随着时间的延长，晶体逐渐长大，图3表1参5     

Assessment of Groundwater Quality and Contamination from Uranium-Bearing Black Shale in Goesan–Boeun Areas, Korea

This study was initiated to identify the impact of metals and uranium enriched soil and black shale in groundwater quality and contamination. From a Piper diagram, groundwater was classified into four types as (Ca+Mg)–HCO₃ type, (Ca+Mg)–SO₄ type, the mixed type of these two and Na–HCO₃ type, reflecting the complicated nature of geology of the study area. Silicate weathering appeared to be the major water–rock interaction. In groundwater, metals including Cr, Pb, Cu and V, previously identified as being enriched in soils and black shale, were much lower in concentrations than Korean and US EPA drinking water guidelines. Instead, Fe and Mn caused major water-quality problems. In the artesian groundwater from an abandoned uranium mine, the uranium concentration was 21.3 µg L^–1, slightly higher than EPA guidelines of 20 µg L^–1. Heavy metals in groundwater appeared to be controlled mostly by sorptions on to Fe- and Mn-oxyhydroxides. They could be remobilised in groundwater with changes of pH and Eh conditions due to acid mine drainage from black shale or the recharge of fresh water. Uranium would be associated with carbonate and sulphate complexes in groundwater. Because of the remaining water-quality problems in the study area, we suggested containment of identified mine wastes, considering remedial measures for local problems with Fe and Mn, continuous monitoring of groundwater and developing groundwater from deep aquifers.     

烟区烟草根际与非根际土壤微生物的生态因子作用分析

烟草根际和非根际土壤的理化性质、微生物区系和土壤酶之间的相互关系尚缺乏系统研究。对南阳烟区6种土壤包括黄褐土和黄棕壤等共13个取样点的烟草根际和非根际土壤的分析表明,根际与非根际微生物之间没有对应相关关系。根际土壤真菌数与解钾菌数、硝化细菌数显著正相关;非根际土壤荧光假单胞菌数与细菌芽孢数极显著正相关,氨化细菌数与放线菌数显著负相关。与土壤容重和空隙度显著相关的仅有根际真菌数(正相关)。与土壤全氮呈显著正相关的分别有根际荧光假单胞菌、纤维素分解菌(正相关)以及根际解磷菌和非根际真菌(负相关)。土壤全C与根际细菌总数显著负相关。土壤pH与非根际纤维素分解菌显著正相关。速效P与非根际放线菌数呈显著正相关。根际土壤蛋白酶活性与根际细菌总数极显著负相关。非根际土壤蛋白酶活性则分别与非根际放线菌和解钾菌显著正相关。根际土壤脲酶活性分别与根际真菌、解磷菌显著正相关,非根际脲酶活性则与非根际纤维分解菌显著正相关。非根际土壤过氧化氢酶活性与非根际细菌总数显著正相关。     

森林生态系统的水文调节功能及生态学机制研究进展

森林水文调节功能是森林所实现的重要服务功能之一,可是由于森林资源被无节制的开采利用,导致人们不断遭受森林破环所带来的洪旱灾害。因此关于森林生态水文功能研究已成为生态学和水文学的研究重点之一。近年来,国内外对森林水文调节过程及其生态学机制进行了广泛深入的研究,所以文章从森林的水文过程出发,对林冠截留、树干流、凋落物层截留、林地水分涵养和蒸发蒸腾及其影响因子的国内外研究现状进行了归纳分析,研究认为林地各冠层均能够截留降雨,降低雨水动能,从而减少地表径流的产生和对地表的冲击;凋落物层能蓄留水分、抑制蒸散、减缓地表径流;而树干流改变降雨水平空间格局,影响水分入渗以及土壤水源涵养。森林结构复杂,明显改变了降雨分配过程,而森林水文过程及调节功能又受到森林结构的制约,因此定量定性探讨森林生态系统的结构、过程与水文调节功能之间关系,是未来森林生态水文功能研究的重点。     

Probabilistic prediction of exposures to arsenic contaminated residential soil

Probabilistic modelling using Monte Carlo simulation has been proposed as a more scientifically valid method of estimating soil contaminant exposures than conservative deterministic methods currently used by regulatory agencies. A retrospective application of probabilistic modelling to an exposure scenario involving arsenic-contaminated residential soil near the former ASARCO smelter near Tacoma, Washington is presented. The population of interest is children, aged 2–6 years, living within one-half mile (0.3 km) of the smelter site. Models that predict urinary arsenic levels based on unintentional soil ingestion and inhalation exposure pathways are used. Distributions of exposure variables are based on site-specific data and previous exposure studies. Simulated urinary arsenic levels are compared with data from two biomonitoring studies performed during the late 1980s. Arsenic distributions produced by simulation and biomonitoring are significantly different, and likely contributors to this difference are discussed. However the probabilistic model provides closer estimations of urinary arsenic levels than conservative deterministic models similar to those used by regulatory agencies, and provides useful information regarding parameter uncertainty. Soil ingestion rate was a driving variable in the probabilistic models. Further quantification of soil ingestion rates is warranted.     

造纸行业环境影响评价中清洁生产评价的实践与思考

造纸行业是资金密集型、技术密集型产业，企业能耗、水耗、资源消耗很大。随着产品产量的增加，行业污染物排放重势必存在增长趋势，造纸行业清洁生产潜力巨大，造纸项目环境影响评价中的清洁生产水平评价变得越来越重要。就造纸行业环境影响评价中清洁生产水平评价的评价指标、评价方法、评价工作中遇到的实际问题以及当前形势对环境影响评价的更高要求以及应对办法等进行了论述。     

汽车尾气和大气中C1—C4烃类分析方法研究

采用熔融性Ａｌ２Ｏ３／ＫＣｌ大孔径毛细管柱，用气相色谱直接进样方式，对汽车尾气中的低碳烃类化合物进行了分析监测。在汽车尾气中检出了３２个色谱峰，对其中的１０种烃类化合物进行了定量测定。浓度在２５μｇ／Ｌ－２０ｍｇ／Ｌ范围内与峰面积有良好的线性关系，方法的相对标准偏差小于１０％；样品的回收率为８５．０％－１１５．０％；最低检出浓度为２５μｇ／Ｌ。     

Intrauterine intervention in a case of recurrent meconium peritonitis

We present a case of recurrent meconium peritonitis detected in the second trimester and treated by intrauterine intervention. Antenatal ultrasound findings included fetal ascites and intra-abdominal calcification. Aspiration of fetal ascites under ultrasound guidance and determination of the bilirubin concentration established the diagnosis of meconium peritonitis. Paracentesis was repeated to remove irritating intestinal contents and to decrease pressure on the fetal thorax. Although the exact cause of the meconium peritonitis remains unknown, the recurrence of the condition suggests a genetic basis. A possibility of cystic fibrosis was not considered because the clinical picture did not suggest it. Intrauterine intervention helped to establish the diagnosis of meconium peritonitis and may have contributed to the good outcome.     

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.     

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.