南京市清凉山公园药用植物调查

对南京清凉山公园的药用植物进行了初步调查,初步统计清凉山公园地区有药用植物41种,隶属于30科;并对其中的枸杞等11种药食同源植物进行了简要阐述,为药用植物资源的有效利用和保护提供一定依据。     

西华段沙颍河和贾鲁河表层水体中有机氯农药研究

采用固相萃取-气相色谱/质谱联用分析水体中有机氯农药的方法,分析了淮河(河南段)沙颍河和贾鲁河表层水体中有机氯农药的分布及组成特征。结果表明,研究区14个采样点中共检出包括六六六、滴滴涕、七氯、环氧七氯、反式九氯、艾氏剂、硫丹硫酸酯和甲氧滴滴涕在内的共13种有机氯农药,其总含量范围在97.41～496.16 ng/L,其中以六六六(HCHs)和滴滴涕(DDTs)为主,各类有机氯农药均未超出国家地表水环境质量标准。研究区的有机氯农药污染除主要源于历史上农田中有机氯农药的残留外,也有近期新农药污染源进入水环境的可能。     

基于DPSR模型的涉及自然保护区海岸带生态安全评估研究

以江苏东台海岸带为例,根据"驱动力-压力-状态-响应力"(DPSR)模型,结合研究区域实际情况,构建了江苏东台海岸带生态安全评价指标体系,同时通过收集东台1984、2001和2011年Landsat遥感影像数据,在地理信息系统(GIS)和遥感(RS)技术的支持下,运用加权主成分分析法对1984、2001和2011年东台海岸带生态安全状况(F值)进行了评价。结果表明,1984、2001、2011年的F值分别为3.242、0.279、-3.521,生态安全水平逐年下降,且呈加速下降的趋势;生态环境的恶化、生物多样性下降等趋势将进一步降低该区域的生态安全水平,并反映在状态指标中。     

中国季风区土壤137Cs背景值研究

 通过测定山东沂蒙山区、江苏苏南丘陵区以及云南滇池流域背景点样品中土壤137Cs活度,探讨了土壤剖面中137Cs的分布状况,发现不同地区不同质地的土壤137Cs 的分布深度有所不同。非耕地137Cs活度呈指数型分布,且与分布深度表现出很强的相关关系;耕地中137Cs活度呈深度分异上的均一性。确定了这几个地区137Cs的背景值分别为1 737.1、1847.2和918.0 Bq/m2。地区土壤137Cs背景值的确定使得 137Cs示踪技术研究土壤侵蚀退化状况、侵蚀和沉积的空间分布成为可能,为土壤资源的可持续利用、土壤侵蚀的经济损益评估及水土保持措施评价等提供有力的技术支持。     

基于137Cs的土壤沉积速率的定量模型

在假设137Cs在耕层中得到充分混合而变得均一的基础上,根据质量平衡原理建立了一个根据农业耕作土壤剖面中137Cs的沉积量和土壤沉积量之间关系的定量模型.在建立模型的过程中,充分考虑了137Cs的衰变常数,年沉降分量,耕层厚度和采样年份等因素.模型的模拟结果表明,137Cs的沉积量与年平均土壤沉积量之间的关系是一种复杂的曲线关系.     

Methyl-mercury affects microbial activity and biomass,bacterial community structure but rarely the fungal community structure

Monomethyl-mercury is one of the most toxic compounds. Methylation of Hg usually appears under anoxic conditions. In Swiss forest soils, methyl-Hg concentrations of up to 3 μg kg⁻¹ soil dw have been observed, but the impact of methyl-Hg on soil microorganisms have rarely been examined so far. In this study, we investigated the effect of increasing concentrations of methyl-Hg (0, 5, 20, 90 μg kg⁻¹ soil dw) on the microbial communities in various forest soils differing in their physico-chemical properties. Experiments were conducted in microcosms under controlled conditions and the basal respiration (BR), the microbial biomass carbon (MBC) and the bacterial and fungal community structures using T-RFLP-profiling were investigated. BR was significantly affected by methyl-Hg. In general, the BR increased with increasing methyl-Hg concentrations, whereas the MBC was significantly reduced. Bacterial communities were more sensitive to methyl-Hg than fungal communities. In five out of seven soils, the bacterial community structures differed significantly between the treatments whereas the fungal communities did not. The impact of methyl-Hg on the soil bacterial communities was site specific. In one soil, a methyl-Hg concentration of already 5 μg kg⁻¹ soil dw significantly affected the relative abundance of 13% bacterial operational taxonomic units (OTU), whereas in other soils concentrations of even 90 μg kg⁻¹ soil dw rarely affected the abundance of OTUs. In this study, for the first time, the impact of methyl-Hg on soil bacterial and fungal communities in forest soils was assessed. We showed that its impact strongly depends on the physico-chemical conditions of the soil and that bacterial communities were more sensitive to methyl-Hg than fungi.     

短波紫外线对高水分稻谷抑霉效果的研究

紫外线辐照是一种安全无污染的处理方式,通过控制短波紫外线的辐照功率、辐照距离、辐照时间和单位面积的稻谷质量四个因素,研究粳稻谷中霉菌总数,表面霉菌量,游离脂肪酸值,电导率和过氧化物酶活性的变化情况,探讨紫外线对稻谷抑霉的效果。并根据Box-Benhnken的中心组合试验进行响应面设计,考察单位面积的稻谷质量、辐照时间、辐照功率对紫外抑霉效果的影响。结果表明:三因素的影响程度为辐照功率单位面积的稻谷质量辐照时间;优化条件为辐照时间15.39min、单位辐照面积的稻谷质量74.7g/dm2、辐照功率136.30W。     

基于主成分分析评价不同类型肥料对向日葵穴盘苗素质的影响

旨在研究不同类型肥料对向日葵穴盘苗生长的影响,筛选适用于向日葵穴盘的肥料类型和壮苗指数。以观赏向日葵‘夏日微风’为试材,采用主成分分析方法综合评价不同类型肥料对向日葵穴盘苗素质的影响。结果表明,花多多高氮钾比例肥提高向日葵穴盘苗叶片叶绿素含量、株高和茎粗,增加幼苗同化物积累;硫酸钾型复合肥更有利于根系生长及根同化物积累。与其他肥料相比,花多多高氮钾比例肥处理的叶绿素含量、株高、茎粗、植株干重、植株鲜重、地上部干重、地上部鲜重分别平均增加15.6%、10.0%、6.6%、15.1%、11.4%、16.6%、13.8%;硫酸钾型复合肥处理的根系干重、根系鲜重、主根长分别平均增加13.3%、35.0%、4.9%。4种肥料肥效大小依次为：花多多高氮钾比例肥>硫酸钾型复合肥>控释肥>花多多1号肥。综上所述,向日葵穴盘苗施肥优选花多多高氮钾比例肥,茎粗/株高×单株鲜重×100可作为向日葵穴盘苗的壮苗指数。     

Effect of Dietary Carbohydrate‐to‐lipid Ratios on Growth Performance,Body Composition,Hepatic Enzyme Activities,and Digestive Enzyme Activities of Juvenile Australian Redclaw Crayfish,Cherax quadricarinatus (von Martens)

A growth experiment was conducted to determine the optimal dietary carbohydrate‐to‐lipid (CHO : L) ratio for the Australian redclaw crayfish, Cherax quadricarinatus (von Martens). Specimens were divided into five treatment groups and fed twice a day to apparent satiation with isonitrogenous and isoenergetic diets with dietary CHO : L ratios of 10.75:1, 5.99:1, 3.60:1, 2.18:1, or 1.33:1. Over the 8‐wk growth trial, redclaw crayfish fed the 2.81:1 and 3.60:1 diets exhibited better weight gain (WG), specific growth rate (SGR), and feed conversion ratio (FCR) than specimens fed the other diets (P < 0.05). Activities of hexokinase and pyruvate kinase were stimulated by elevated levels of dietary carbohydrate, whereas activities of lipase and alkaline phosphatase were stimulated by elevated levels of dietary lipid. Dietary CHO : L ratios significantly affected digestive enzyme activities (P < 0.05), except for trypsin (P > 0.05). On the basis of the analysis of growth, FCR, and costs of culturing redclaw crayfish, the optimal growth and costs occurred when the dietary carbohydrate and lipid levels were 290.10 g/kg and 80.70 g/kg, respectively, corresponding to a CHO : L ratio of 3.60:1. These results indicate that a CHO : L ratio of 3.60:1 is optimal for rearing redclaw crayfish and that this species uses carbohydrate more efficiently than lipid.     

人工湿地对水体悬浮泥沙的影响

根据自然水体湿生植物(挺水植物)、浮叶植物以及沉水植物的空间分布规律,利用水生高等植物菖蒲(Acorus calamus)、菱(Trapa incisa)、黑藻(Hydrilla verticillata)、苦草(Vallisneria spiralis)和狐尾藻(Myriophyllum spicatum)构建的阶梯式人工湿地,定量化研究了植物群落对不同浓度悬浮泥沙水体在不同水力停留时间下的影响,并对输入悬浮泥沙浓度、输出悬浮泥沙浓度、水力停留时间等参数进行了比较分析。结果表明:(1)输入悬浮泥沙浓度依次为98.69,191.76,273.13 mg/L,平均为187.76 mg/L,流经人工湿地植物群落后,输出植物组的水体悬浮泥沙平均浓度为26.52 mg/L,为对照组平均浓度51.96 mg/L的51.04%;(2)输出人工湿地的悬浮泥沙浓度随输入悬浮物浓度的增加而增加,随水力停留时间的延长而降低,回归方程为Cplant out=1.231 0.170Cin-0.356H;(3)试验水体中滞留的悬浮泥沙浓度随输入悬浮物浓度的增加而增加,随水力停留时间的延长而减小,回归方程为Cplant water=1.158 0.261Cin-0.623H;(4)悬浮泥沙在人工湿地中的沉降量随输入悬浮物浓度的增加和水力停留时间的延长而增加,回归方程为Wplant=0.810Cin 0.886H-2.340;(5)要维持人工湿地沉水植物生长需要的透明度条件,输入悬浮泥沙浓度(Cin)与最小水力停留时间(Hmin)要满足如下关系:Hmin=0.419Cin-38.478(98.7相似文献