安防领域中的电视数字监控系统

通常把防入侵报警、电视监控、出人口控制作为安全防范技术系统的三要素。而电视监控在其中的地位和作用日渐突出,这是因为图像(视频信号)本身具有信息量大的特点,是报警复核、动态监控、过程控制和信息记录的有效手段。有安防必有电视监控。应该指出:目前的电视监控基本上是经典应用     

Petroleum hydrocarbons and their effects on fishery species in the Bohai Sea, North China

Systematic studies on the changes in concentrations of petroleum hydrocarbons (PHs) and their e ects on fishery species in the Bohai Sea during 1974–2004 are presented. Changes in PHs concentrations were closely related to Yellow River runo . Concentrations of PHs accumulated in fish and shrimp increased by about 0.712 mg/kg dry weight when trophic level of fish and shrimps increased by 1. Attention should also be paid to the high PHs concentrations in mollusks along the coastal waters of the Bohai Sea. Average concentration of PHs in the adjacent coastal waters of Tianjin City during 1996–2005 decreased the population growth rates of fish, crustaceans and mollusks in the Bohai Sea by 2.58%, 6.59% and 2.33%, respectively. Therefore, PHs have significantly contributed to the decline in fisheries in the Bohai Sea, and they must be reduced to realize the sustainable fisheries.     

干细胞有望挽救濒危物种

研究人员发现,干细胞能演变成不同的特殊细胞。干细胞之所以颇具科学研究价值,这是由于它们能转换成为身体的任何类型细胞,具有特殊的“多能性”。     

预防外来物种入侵的立法对策

对我国目前预防外来物种入侵问题的现状进行了分析,指出了我国在预防外来物种入侵立法上没有专门的针对性法律,立法目的有偏差、法律涉及范围有限的弊病,提出了明确立法目的、制订专项立法与中长期规划、适当扩大相关法律覆盖范围、完善法律法规和顺应国际形势的立法对策.     

广州城区生态安全岛森林生物量、叶片滞尘和物种多样性研究

通过样方调查、植被生物量估算和植物叶片滞尘测定等途径,研究广州城区生态安全岛森林的生物量、植物叶片滞尘和物种多样性的作用.结果表明:①生态安全岛植物群落的生物量介于69.61～371.34t·hm-2之间,碳储量介于34.81～185.67t·hm-2之间.随着植物群落的正向演替,生物量和碳储量不断增加.②不同采样点植...     

深圳沿岸海水入侵灾害现状研究

2008年8月~2009年8月期间对深圳沿海岸18个海水入侵观测站位进行地下水水质连续监测,选用矿化度、C l-、SO42-、rC l-∶rHCO3-、K+指标作为评价因子,运用模糊数学方法对区内海水入侵现状做出综合评价。结果能较客观准确地反映调查区域的海水入侵趋势和程度,评价结果与代表性指标氯度和矿化度浓度变化有很好的相关性。结果显示总体上说目前深圳沿岸的多数地区海水入侵程度不大,但在局部地区入侵状况严重。     

滇缅国际通道沿线紫茎泽兰(Eupatorium adenophorum)的分布规律及其与环境因子的关系

为探讨道路工程建设与环境因子对紫茎泽兰入侵的生态效应,在滇缅国际通道沿线选取34个样点采集了107个样方,分析了通道沿线紫茎泽兰的分布规律.研究结果表明,①公路所在路段、公路类型、公路建设年限、公路工程用地类型及样点与公路的距离等道路因子显著影响紫茎泽兰的存在度(p＜0.01或P＜0.05),但这些因子不影响紫茎泽兰的丰富度(p＞O.05);工程用地类型及离公路的远近显著影响紫茎泽兰的优势度(p＜0.05).②大理-丽江段紫茎泽兰的存在度明显低于保山-大理、芒市一保山和瑞丽.芒段(p＜0.05),省道沿线紫茎泽兰的存在度明显低于高速公路、国道和乡村公路(P＜0.05);弃土场和高架桥用地的紫茎泽兰存在度和优势度明显高于其它工程用地类型(p＜0.05);紫茎泽兰的优势度随着与公路垂直距离的增加而明显下降(p＜0.05).③紫茎泽兰的分布受经度、纬度的限制,但与海拔高度、坡度、坡向等地形因子无关;土壤有机质、全氮和总磷与紫茎泽兰的存在度呈显著负相关关系(p＜0.01),表明紫茎泽兰容易在贫瘠的土壤环境中生存和扩展.④植被类型与紫茎泽兰的丰富度和优势度存在显著相关关系(p＜0.01).迹地次生灌丛或草地、弃土场荒地等受人类干扰较大的植被或生态系统容易受到紫茎泽兰入侵的影响;灌木盖度与紫茎泽兰的丰富度和优势度存在显著负相关关系,自然灌丛覆盖较好的植物群落能够较好地抑制紫茎泽兰的入侵和扩展.     

江苏省生物物种资源监测体系总体方案探讨

通过调查研究江苏省生物物种资源现状和相关部门监测能力,提出了我省监测的总体目标、工作要求、工作任务,分析了江苏省生物物种资源面临的威胁。根据江苏省生物资源分布特点及保护目标,制定了包括自然保护区、湿地、森林生态系统等生物物种生境及濒危物种、外来入侵物种在内的江苏省生物物种重点监测样地和对象,为今后生物物种资源的动态监测提供了比较可行的技术方案。     

Effects of fulvic acid and humic acid on aluminum speciation in drinking water

This article focused on the influences of fulvic acid and humic acid on aluminum speciation in drinking water. Factors including the concentration of residual chlorine and pH value had been concerned. Aluminum species investigated in the experiments included inorganic mononuclear, organic mononuclear, mononuclear, polymer, soluble, and suspended forms. It was found that the e ects of fulvic acid and humic acid on aluminum speciation depended mainly on their molecular weight. Fulvic acid with molecular weight less than 5000 Dalton had little influence on aluminum speciation; while fulvic acid with molecular weight larger than 5000 Dalton and humic acid would increase the concentration of soluble aluminum significantly even at concentration below 0.5 mg/L (calculated as TOC). Aluminum species, in the present of fulvic acid with molecular weight larger than 5000 Dalton and humic acid, were more stable than that in the present of fluvic acid with molecular mass less than 5000 Dalton, and varied little with reaction time. Within pH range 6.5–7.5, soluble aluminum increased notably in water with organic matter. As the concentration of residual chlorine increased, the e ects of fulvic acid and humic acid became weak. The reactions between humic acid, fulvic acid with large molecular weight, and aluminum were considered to be a multi-dentate coordination process. With the consideration of aluminum bioavailability, reducing the concentration of fulvic acid and humic acid and keeping the pH value among 6.5–7.5 were recommended during drinking water treatment.     

莱州湾地区海水入侵变化动态研究

通过对莱州湾地区11个剖面60多个观测井进行测定,统计分析了水样的氯度、矿化度数据,得出了莱州湾地区海水入侵的时空变化规律。结果表明,在时间上,海水入侵的状况基本上保持稳定,受月季变化影响较小;空间上,地下水水质呈从沿岸向内陆由咸变淡的梯度变化趋势,海水入侵程度由近海岸至内陆逐渐降低,入侵面积和过渡带面积进一步扩大,表明莱州湾海水入侵程度日趋严重。