水体的营养水平对苦草(Vallisneria atans)生长的影响

在室外控制条件下,以太湖梅梁湾水体现状营养水平(ρ(TN)为5 mg/L和ρ(TP)为0.2 mg/L)为依据,研究营养盐含量升高对苦草生长的影响.结果表明:①在满足光补偿点及无种间竞争等的条件下,苦草在营养水平为ρ(TN)＞10 mg/L和ρ(TP)＞0.4 mg/L的水中也能成活.②随着营养盐含量的升高,苦草生物量的增长率逐渐降低,当水中ρ(TN)达到10 mg/L和ρ(TP)达到0.4 mg/L时,苦草的生物量开始减少;营养盐含量升高对苦草叶片特征的影响不明显,而苦草根状茎的生物量却随着营养盐含量的升高而逐渐减少,当水体营养水平达到ρ(TN)为10 mg/L和ρ(TP)为0.4 mg/L时,除叶片长度外,苦草的其他形态指标值均显著下降.③在梅梁湾水体现状营养水平的基础上,当水中磷含量增加1倍时对苦草生长造成的抑制作用大于氮含量增加1倍时;当二者均增加时,对植物生长造成的抑制作用显著增加.     

添加不同钝化剂降低污泥堆肥的植物毒性研究

高温堆肥后污泥的土地利用可充分发挥资源化、无害化的优势,污泥土地利用防止重金属污染一直是污泥施用中最重要的问题。通过测验发芽率指数这一代表植物毒性的指标证明,通过在污泥堆肥中加入粉煤灰、磷矿粉和草炭等不同的改性剂或重金属钝化剂可大大降低堆肥的植物毒性,从而降低污泥中重金属的可利用性。     

雨天硫酸盐化速率样品扩散分析

选择采样期不同降雨天数的碱片,测定余边的硫酸盐化速率含量,其结果为：采样期全月无雨时,余边上的硫酸盐均未检出;半月以上至全月有雨时检出率为１００％,检出量占样品量的２．７０～１５．９５％。经扩散试验,查清了余边上的硫酸盐主要是有效面积上采集的样品的扩散,并提出了相应的修正方法。     

Essential hazard and process safety assessment of para-toluene sulfonic acid through calorimetry and advanced thermokinetics

Para-toluene sulfonic acid is a typical intermediary for the synthesis of pharmaceuticals, pesticides, and dyes and is a catalyst for organic synthesis. The consumption of para-toluene sulfonic acid used in organic synthesis has increased substantially. The toluene sulfonation process is the central path for synthesizing para-toluene sulfonic acid in China. However, the process has risks and has resulted in numerous disasters. This study utilized a reaction calorimeter 1 to reproduce the commercial toluene sulfonation process in a laboratory. The para-toluene sulfonic acid product was examined with an accelerating rate calorimeter and through differential scanning calorimetry. Both differential and integral isoconversional methods were used to determine the thermal stability of and appropriate thermokinetic models for para-toluene sulfonic acid. The safety parameters of para-toluene sulfonic acid were estimated. The research findings can be used for optimization of the toluene sulfonation process and for safe handling of para-toluene sulfonic acid.     

Effects of age and sex ratios on offspring recruitment rates in translocated black rhinoceros

Success of animal translocations depends on improving postrelease demographic rates toward establishment and subsequent growth of released populations. Short‐term metrics for evaluating translocation success and its drivers, like postrelease survival and fecundity, are unlikely to represent longer‐term outcomes. We used information theory to investigate 25 years of data on black rhinoceros (Diceros bicornis) translocations. We used the offspring recruitment rate (ORR) of translocated females—a metric integrating survival, fecundity, and offspring recruitment at sexual maturity—to detect determinants of success. Our unambiguously best model (AICω = 0.986) predicted that ORR increases with female age at release as a function of lower postrelease adult rhinoceros sex ratio (males:females). Delay of first postrelease reproduction and failure of some females to recruit any calves to sexual maturity most influenced the pattern of ORRs, and the leading causes of recruitment failure were postrelease female death (23% of all females) and failure to calve (24% of surviving females). We recommend translocating older females (≥6 years old) because they do not exhibit the reproductive delay and low ORRs of juveniles (<4 years old) or the higher rates of recruitment failure of juveniles and young adults (4–5.9 years old). Where translocation of juveniles is necessary, they should be released into female‐biased populations, where they have higher ORRs. Our study offers the unique advantage of a long‐term analysis across a large number of replicate populations—a science‐by‐management experiment as a proxy for a manipulative experiment, and a rare opportunity, particularly for a large, critically endangered taxon such as the black rhinoceros. Our findings differ from previous recommendations, reinforce the importance of long‐term data sets and comprehensive metrics of translocation success, and suggest attention be shifted from ecological to social constraints on population growth and species recovery, particularly when translocating species with polygynous breeding systems.     

Female oviposition-site preference and egg hatching success in the damselfly Calopteryx splendens xanthostoma

By removing males and controlling the rate of water flow past oviposition patches in an experimental area, we showed that female Calopteryx splendens xanthostoma preferred to oviposit in fast flowing water rather than slow flowing water. A series of manipulations revealed the fitness benefits to females for this preference: eggs placed in fast-flowing water developed significantly faster and showed significantly lower mortality than eggs placed in slow-flowing water. A major factor determining this difference was the deposition and growth of encrusting algae which prevented the successful hatching of eggs in slow-flowing water.     

乐山市区大气硫氧化物污染状况及相关因子分析

本文研究了乐山市区较大面积范围内的大气硫氧化物相对污染水平。通过分析绘出了较详细的污染图谱;在得出SO_x时间分布规律基础上,了解了与它相关的因子;用模糊聚类方法,对乐山城区大气SO_2监测点提出了优化方案;并针对乐山市的大气状况,提出了对策。     

基于210Pb和137Cs计年法的黄河下游湿地沉积速率研究初探

本文利用²¹⁰Pb和¹³⁷Cs计年方法分析探讨黄河下游湿地沉积速率演化与上游水沙变化的响应关系。结果表明，²¹⁰Pb比活度大致指数衰减趋势以及¹³⁷Cs蓄积峰的鉴出，表明放射性核素手段在黄河下游湿地的沉积学研究具有一定可行性。基于²¹⁰Pb的CIC模式和CRS模式得出的沉积速率分别为1.68 cm/a和0.67~2.76 cm/a；基于¹³⁷Cs剖面的1963年和1986年两个蓄积峰，计算自下而上沉积速率分别为2.67 cm/a、1.08 cm/a和1.21 cm/a。研究发现，近几十年黄河下游湿地沉积速率呈逐渐减小趋势，这与黄河流域气候变化、上游流域建坝、水土保持和下游水资源利用存在密切关系。此外，水库调度方式也在一定程度上影响下游沉积速率，虽然下游淤积量不变，但洪峰的"削平"导致泥沙难以淤积于湿地。     

判别符合率递增法辅助酚类化合物构效关系研究

计算了酚类化合物的分子连接性指数及其在正辛醇和水之间的分配系数ｌｏｇＰ，运用新近提出的数学方法－判别符合率递增法，对酚类化合物的构效关系进行了研究，所得结果优于逐步判别法及穷举法。     

大气监测仪器维护检修能力的评价

一直以来,环境大气监测的数据精度与维护成本,始终是数据应用部门和数据提供部门的难题之一.作者谷学先生根据多年的实档践,首次提出,运用数据对大气监测仪器维护管理进行评价的可行性,并试图建立仪器维护管理作业量化的评价系统.在仪器维护管理中,任何时候,都很难完全排除技术水平比较低的仪器维护检修人员,为了回避这种实际情况,作者通过对数字的分析指出,急需构建环境大气监测仪器维护管理业务能力的评价系统,并期待地方自制体通过评价手段,来选择和指导监测仪器维护管理人员.从而提高数据的精度和减低运转经费的开支.