基于人工鱼群算法南宁市内河水质综合评价的投影寻踪回归分析

针对目前我国城市内河普遍遭到污染的问题,在分析影响内河水质因素的基础上,选取BOD5（五日生化需氧量）、CODcr（化学需氧量）、石油类、挥发酚、NH3-N（氨氮）、总磷等6个主要因素作为评价因子,建立了城市内河水质评价的投影寻踪分析模型,采用人工鱼群算法对评价模型进行优化,并将该模型应用于南宁市10条内河水质的评价与排序。研究表明,用投影寻踪回归分析法进行水质评价,避免了传统评价方法由于主观原因造成的误差,评价结果合理可信、方法简单,为我国城市内河水质的评价提供了新途径。     

国外内陆渔业设施的应用现状

９０ 年代世界渔业稳步发展,内陆渔业发展显著。随着世界高新技术不断引进至渔业的科学技术中,内陆渔业应用的一些设施日趋先进。     

Evaluation of an alternative salt mixture to culture Pacific white shrimp (Litopenaeus vannamei) in inland aquaculture

Pacific white shrimp, Litopenaeus vannamei, exhibit a remarkable ability to tolerate low‐salinity environments, facilitating its culture far from coastal areas using various production systems at salinities less than 15 g/L. Recirculating aquaculture systems (RAS) and biofloc systems are usually operated using reconstituted sea salt (RSS), which is a considerable financial burden to commercial producers due to its higher price. Current study was carried out with the objective of testing the efficacy of a low‐cost salt solution to replace expensive RSS to grow shrimp under laboratory conditions. Low‐cost salt mixture (LCSM) was formulated to yield sodium, potassium, calcium and magnesium concentrations closely comparable to that of diluted seawater using agriculture grade sodium chloride, magnesium chloride, magnesium sulphate, potassium oxide, calcium chloride and sodium bicarbonate. Growth trials were conducted at three different salinities of 3, 6 and 15 g/L, incrementally replacing RSS with LCSM (0, 2.5, 25, 50, 75 and 100%) at four replicates per treatment. Twenty juvenile shrimp were reared for 42 days in 150 L polyethylene tanks. Ionic profile of water, ionic profile and osmolality of shrimp haemolymph were determined to justify growth and survival data through analysing ionic variations and osmoregulatory capacity of shrimp. At the conclusion, no significant differences were observed in survival, growth, osmoregulation and levels of cations in shrimp haemolymph between RSS and LCSM treatments at all salinities examined. Results reflect the potential use of LCSM to replace RSS which could be an excellent solution to bring down the cost of production in inland shrimp aquaculture.     

都市型自然保护区系统构建与规划探讨

从国内外都市型自然保护区的发展现状出发,总结归纳了都市型自然保护区系统构建方法以及保护区规划原则和理论依据,旨在为都市型自然保护区的研究提供一定的理论探讨。     

封闭型内陆湖泊夏季氮素赋存特征——以达里诺尔湖为例

氮素是影响湖泊初级生产力的主要因素之一。近年来,受气候干旱及上游用水量增加等因素的影响,大多数封闭性内陆湖都面临着湖面萎缩、湖水因营养盐浓度增加而逐渐恶化的问题。本文以内蒙古高原境内封闭型内陆湖泊——达里诺尔湖为例,于2017年夏季采集湖水、间隙水、沉积物、入湖河流等样品。对湖泊氮素赋存特征、迁移趋势做出分析,并且对入湖河流携带的氮素对湖泊水质的影响展开讨论。结果表明:氨氮(NH_4~+-N)是上覆水中占比例最高的形态氮。总氮(TN)、硝酸盐氮(NO_3~--N)、亚硝酸盐氮(NO_2~--N)含量随水深从浅到深基本保持不变。只有B6、E2、E5样点的NH_4~+-N在水深1.5 m向下处含量有所波动。表层沉积物TN均值2 809.97 mg·kg~(-1),可交换态氮占TN含量6.74%;河水中占比例最高的形态氮是NO_3~--N,四条入湖河流中,TN、NH_4~+-N含量最高的是沙里河,NO_3~--N含量最高的是亮子河;每年由入湖河流携带入湖的TN量为120 t。总体来看,达里诺尔湖氮素赋存特征为:NH_4~+-N是上覆水的主导形态氮,TN及各形态氮含量在不同深度水层掺混均匀,无明显的分层现象。沉积物TN含量较高且氮素迁移能力较强。TN、NO_3~--N、NO_2~--N表现为由沉积物到上覆水的释放状态,而NH_4~+-N则以上覆水到沉积物的吸附状态为主。河流的输入对湖水TN含量有稀释作用,但会增加湖水NO_3~--N的负荷。     

大都市外围乡村地区国土空间规划双评价与分区研究——以北京昌平为例

为推进乡村分类发展，优化乡村发展模式，以大都市外围北京昌平区为研究对象，利用空间分析法和三维魔方法，进行研究区资源环境承载能力与国土空间开发适宜性双评价，并基于双评价结果进行三类空间分区和国土空间综合功能分区，以打造人类与自然环境和谐共处的生态化绿色新城。结果表明：1）昌平区生态保护极重要区占全区56.83%，分布在西部和北面地表植被覆盖为森林的广泛山区；农业生产适宜区面积相对较小，占全区2.01%，适宜区、较适宜区和一般适宜区主要紧密交错分布在昌平平原中部；城镇建设适宜区占全区11.58%，占昌平城镇村及工矿用地面积44.43%。2）昌平区生态保护功能区、城镇建设功能区和农业生产功能区，面积依次是1 076.47、181.61和87.96 km2，分别占全区80.12%、13.52%和6.55%。全区以生态保护功能区为主，且三类空间分区在镇域分布极不均匀。3）昌平中心集约提质区、科教文娱引领区、文旅康乐涵养区和城乡腹地承载区，面积所占比例分别为5.16%、15.96%、69.08%和9.29%。中心集约提质区主要包括城北街道、城南街道和南邵镇；科教文娱引领区主要包括百善镇、北七家镇、...     

Responses of nitrogen cycling and related microorganisms to brackish wetlands formed by evapotranspiration

Elevated evapotranspiration due to warmer air temperature could raise salinity and nutrient levels of some inland wetlands, potentially impacting nitrogen cycling. To characterize the impact of high evapotranspiration on soil microbial nitrogen cycling in inland wetlands, we compared freshwater and brackish marsh(or non-marsh) wetlands in terms of sediment ammonia-oxidizing rate(AOR), denitrifying rate(DR), and related microbial communities in a typical inland basin, the Hulun Lake basin, in Chi...     

Germination capacity of Thekopsora areolata aeciospores and the effect of cone rusts on seeds of Picea abies

Mature Norway spruce (Picea abies) cones of different ages and colonized by Thekopsora areolata were collected in northern Finland 2009–2010. The germination capacity of aeciospores collected from intact aecia was measured on water agar and compared across cone age. Seed formation was investigated in healthy cones and those infected by T. areolata, Chrysomyxa pirolata, Chrysomyxa ledi, and seed germination was also measured for healthy cones and those infected by T. areolata. Unsporulated aecia of T. areolata occurred in 0- to 4-year-old cones. Aeciospores from current-year cones did not germinate and the germination capacity was significantly higher in one- to three-year-old cones than in older or current-year cones. However, a small number of aeciospores remained viable in four-year-old cones. Seed number and apparent health were significantly lower in cones infected by T. areolata and C. pirolata than in healthy cones or cones infected by C. ledi. Seed germination was significantly lower in cones infected with T. areolata compared to seeds from healthy cones. Our results suggest that infected cones more than one-year old continue to spread T. areolata for several years after the initial infection and fruiting, and thus promote the likelihood of epidemics and virulence of local outbreaks. Although cones infected by T. areolata and C. pirolata form significantly fewer seeds and of diminished viability, C. ledi does not appear to affect seed formation and health in Norway spruce. We recommend all rust-infected cones to be removed from orchards to improve stand health, reduce the risk of local outbreaks, and thereby increase the production and quality of Norway spruce seed.     

三北地区内陆盐水生物资源及其渔业利用

报道了1981－2001年对中国三北地区内陆盐水生物资源调研的结果，总计对大约50个水体进行了采样调查，其中盐度为0．8－286．0，碱度1．75－67．00mmol/L，pH7.3-10.6，离子系数0．45－67．00，共见到浮游植物132种和变种，浮游动物193种，底栖动物31种，鱼类37种，根据出现率和平均生物量，有33种浮游植物，34种浮游动物和6种底栖动物为三北地区内陆盐水的主要种类，此外，还讨论了浮游生物对盐度，碱度和pH的适应性，内陆盐水生物资源的渔业利用以及利用盐水或耐盐性淡水枝角类作为海水鱼苗活饵料的前景。     

阿瓦提丰收灌区零通量面的形成变化规律研究

以新疆阿瓦提县丰收灌区为例，通过负压计、地下水埋深监测，研究了在干旱内陆河灌区地面灌溉条件下零通量面形成变化规律和田间水的运动转化过程。分析结果表明：灌溉季节开始前，在地表下100cm处形成稳定、单一的发散型零通量面（ZFP）；冬灌后，在同样土层深度形成单一的聚合型ZFP。灌溉季节，头水和第2水期间，最终在地表下100cm处形成稳定的单一发散型ZFP。第3水至第5水期间，灌水后早期有多个ZFP，晚期ZFP消失，土壤水和地下水的运动表现为地下水补给土壤水的全蒸发型运动状态。