Wave sloshing in corrugated bottom tanks with two-dimensional flow

The boundary integral element method based on Green's formula is applied to the analysis of transient flow problem in corrugated bottom tanks. The problem is formulated as a two-dimensional linear, initial boundary value problem in terms of a velocity potential. The Laplace equation and the boundary conditions, except the dynamic boundary condition on the free surface, are transformed into an integral equation by the application of Green's formula. Finite Difference discretization is applied timewise. Initially a triangular wave on the free surface is assumed to be formed. The height of the triangular corrugated bottom is varied between 1/10 and 1/5 of the tank depth. The form of the free surface and the equipotential lines for the flow in the tank are presented at different time steps. An accuracy analysis is performed and distortion in time is considered. Proper coefficients for solutions are derived and presented. The results show that utilization of triangular corrugated bottoms may help to regulate the flow in tanks.     

南沙海洋沉积物中生物标志化合物的组成及地化意义

对１９９０年取自南沙海域１０２站位岩芯柱样中饱和烃进行色谱－质谱分析，研究沉积物中生物标志化合物组成和地球化学意义，结果表明，正构烷烃，类异戊二烯烷烃，甾烷和藿烷组成特征指示了其先质主要为海洋浮游生物和细菌，部分为陆源高等植物，反映了南沙海洋沉积有机质起源于这些生物，较丰富的胡萝卜烷在和Ｐｒ／Ｐｈ比值低，说明沉积环境具强还原性，随沉积物理埋藏深度增加，藿烷和藿烷以及藿烷异体之间，均存在明显的成岩转     

马尾藻活性物质对水稻幼苗抗旱性的作用

从亨氏马尾藻(Sargassum henslouianum)中提取活性组分,对水稻幼苗根施培养,10d后进行干旱处理,结果表明,用马尾藻活性提取物处理者在严重干旱3d后的电解质渗漏率和丙二醛(MDA)含量分别比对照降低了13．1％和15．8％,而超氧化物歧化酶(g)D)活性比对照提高了131．9％,这说明马尾藻活性物质可以减轻干旱幼苗的自由基伤害和膜脂过氧化作用．减轻细胞膜的损伤程度,从而提高其抗旱性。     

贝加尔湖的污染与富营养化

The long term systematic investigations of ion composition components (bicarbonates, chlorides, sulphates, magnesium, calcium, sodium, potassium) and trophic status components (suspension, chlorophyll-a, mineral and organic forms phosphorus and nitrogen, carbon, silica) of water from the lake proper, its tributaries and atmospheric precipitation, which make up the main share of substance supply in to the lake, as well as the Angara river, being the source of substance discharge allowed the lake recent state to be evaluated in terms of both chemical pollution and possible eutrophication of its water. The similar (in terms of river runojf) periods of 50-ies and 80-ies have been compared. It was revealed that as a result of industrial activity 409 thousand tons of mineral substances (27.2 thousand tons of chlorides, 162 thousand tons of sulphates and over 200 thousand tons of organic substances) are supplied in the lake annually. The supply of substances of the anthropogenic origin is higher for the South Baikal than that for the North and Middle Baikal (the sum of mineral substances in 3.6 times; sulphates in 5 times, organic substances, including hydrocarbons in 7 times).The absence of abundant phytoplankton in the period studied when the ratio of silica to phosphorus is optimum (over 100), as well as a revers correlation between winter nitrogen content and spring of chlorophyll-a concentration in the Baikal water and revers dependence between the suspension and chlorophyll-a along the Selenga river valley lead to the conclusion that Baikal water contains toxicants. It is verified by the presence of polychlorbiphenyls (PCB), poly-chlordibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) for the whole food web with the maximum PCDD/PCDF (TEQ to 175 P g · g^-1) concentration in the seal blubber. The levels are comparable with those reported for ringed seal (phoca hispida), living in the Baltic sea and Bar-row Strait Inlet in the Canadian Arctic.     

富营养水体磷酸酶动力学参数的季节变化——水体酶研究之一

本文报道了武汉东湖富营养湖区(东湖Ⅰ站)水体磷酸酶动力学参数(最大反应速度V_(max)和米氏常数K_m)的季节变化规律,在6月、8月和11月(或邻近时间),湖水溶解正磷酸盐的浓度较低而叶绿素的浓度达到高峰值,同时,V_(max)达到最大值,K_m值明显减小。因此,浮游植物可以通过提高酶的反应速度以及增强酶与底物的亲和能力这两种方式有效地利用有机磷。实验结果表明,湖水中对紫外线敏感的磷化合物可能是磷酸酶的竞争性抑制剂。     

CuCl2—石墨层间化合物的结构及电化学性能研究

用直接反应法制备了C/CuCl2 从 6 .3- 88.2的五种不同的CuCl2 -石墨层间化合物 .X射线粉末衍射分析指出它们分别为一阶、一二混阶、二阶和高阶 (大于二阶 )石墨层间化合物 ,Ic(°A)分别为 9.4 6、9.4 6 /11.6 3、12 .0 99、15.74、18.394 °A。通过循环伏安法对一阶、一二混阶层间化合物的电化学性能进行了研究 ,并测试了作为锂电池阴极材料的电池充放电循环性能     

2种海藻中半挥发性物质的成分分析

选择孔石莼(Uiva pertusa)和蜈蚣藻(Grateloupia filicina)两种海藻在挥发油测定器中用乙酸乙酯通过循环蒸馏萃取,浓缩后用电子轰击(electron impact,EI)源在全扫描检测模式下进行检测。各分离组分采用美国国家标准局NIST147及WILEY7谱库检索定性,采用色谱峰面积归一法进行相对定量。从两种海藻中共鉴定出61种半挥发性化合物,以醛类物质种类最多,半挥发性组分主要是醛类、脂肪酸类和醇类物质。两种海藻中含量最高的均是棕榈酸和十五醛。烘干对鉴定出的半挥发性物质种类没有影响,但对同一类物质,保留时间短的组分烘干后质量分数有增加的趋势,而保留时间长的组分质量分数有减少的趋势。该方法是一种灵敏、准确的分析方法,可以为海洋微藻中半挥发性成分的研究提供科学依据。     

改性当地土壤技术修复富营养化水体的综合效果研究:Ⅲ.模拟湖泛水体的应急治理效果

为了探索原位解决湖泛引起的水体感官和水质恶化问题,本研究在室内考察了改性当地土壤对湖泛黑物质的絮凝去除效果及土壤和沙子覆盖对絮体再悬浮的抑制作用,并在梅梁湾围隔实验中考察了改性当地土壤湖泊综合修复技术对模拟湖泛水体嗅味物质和营养盐的去除及水体溶解氧(DO)的改善效果.室内研究结果表明,壳聚糖改性土壤对湖泛水体黑物质的絮凝去除效果比聚合氯化铝更佳,在55 mg/L的壳聚糖改性土壤投加量时,水体浊度从对照的 >2000NTU降低到5 NTU,土壤和沙子覆盖能够有效地减少湖泛水体黑物质絮凝去除后的再悬浮.现场研究结果表明,该技术处理30 min后总氮和总磷的去除率达到97.0%,嗅味物质DMTS和MIB的去除率达到75.0%以上,水体表层DO增加了75.0%,底层DO增加了183.5%.改性当地土壤湖泊综合修复技术对湖泛水体的感官和水质起到明显的应急改善效果.