春季石家庄市水体浮游植物群落结构调查与分析

为探索春季石家庄市水体浮游植物群落组成与结构特点,及其主要环境影响因素,对水体中浮游植物的种类组成、细胞密度、环境因子等指标进行了调查,分析了其物种优势度、多样性指数,并对各水体的浮游植物组成与环境因子进行了聚类分析和相关性分析。结果发现:在春季的石家庄市水体中,共检出浮游植物7门47属76种,以绿藻门种类最多,约占总数的39.47%,其次为硅藻和蓝藻,裸藻、金藻、黄藻和甲藻种类很少且仅在个别采样点位出现。水体中硅藻细胞密度最高,平均为1.0×10~7 cells/L,占丰度组成的61.84%,其次为绿藻和蓝藻。值得注意的是,岗南水库是所有水体中仅有的金藻丰富型水体,它的金藻细胞密度高达4.5×10~6 cells/L。物种优势度分析和多样性指数分析显示,石家庄市水体中以中度富营养型指示藻类为优势类群,基本处于中度污染水平;水体聚类分析表明,石家庄市水体的浮游植物组成受整体水环境因素影响不明显;而单环境因子数据及其与浮游植物的相关性分析表明,石家庄市水质酸化严重(pH值低于6.0),除科大牧星湖和岗南水库外,多数水体处于劣V类水平,主要超标物为pH值、总磷、总氮和COD,而这可能是导致蓝藻、绿藻等耐污性种类大量繁殖的主要因素。因此,对石家庄市水体中浮游植物群落组成与结构变化的生物学监测,是进行石家庄市地表水水质监测及生态保护的重要途径。     

From ‘just a swimmer’ to a ‘swimming mother’: women’s embodied experiences of recreational aquatic activity with pre-school children

Increased academic attention on the gendering of leisure pastimes in recent years has highlighted the centrality of the gendered body in influencing how leisure is accessed, experienced and transformed. To date, however, little attention has been paid to how women experience aquatic leisure activity, the second most popular form of leisure activity in the UK, and where female participation predominates. This paper presents results from research investigating the aquatic leisure experiences of 22 women, with children aged under 3, in the North-East of England. A number of key themes emerged from the data, which highlighted the centrality of the gendered, lived body as a key social construct contouring participant perceptions in the swimming pool environment. Women reflected upon their self-perceived physical deficiencies when wearing revealing swimming costumes, particularly under the critical gaze of ‘other’ bodies, whether present or imagined. The co-presence of other bodies was also central in shaping lived experiences, and the presence of ‘dependent’ children’s bodies shifted bodily intentionality away from the self towards perceived maternal responsibilities and the management of perceived risks, including ‘dirt’ and ‘germs’ and the negotiation of the tacit rules of the swimming pool. Results also suggest that the emphasis on maternal responsibility in aquatic leisure activity and timing of parent-toddler sessions could lead to reproduction of gender inequalities and the exclusion of some fathers from participation.     

水产品加工业供应链风险及其控制策略

根据对文献的研究成果,结合对水产品加工业的深入调研分析,本文着重从供应、物流、财务、信息、需求、环境等方面对水产品加工业供应链风险进行剖析。供应链中各种风险因素之间并非独立存在,而是相互影响、互为因果。因此,在明确水产业供应链每种风险产生根源及其变动规律的基础上,提出适宜的风险控制策略,以期规避风险,确保水产业供应链整体安全高效运行。     

水产品供应链组织效率的影响因素

影响水产品供应链中企业合作的因素是多方面的,其中合作效率是最为重要的影响因素,主要受到合作能力和合作意向的影响.应利用利益杠杆调动水产品供应链内部诸方面的积极性,使各主体在各个经营环节来实现利益平衡,建立科学、合理的利益分配机制;通过市场约束、交易成本内部化、合同约束等,完善水产品供应链的约束机制;建立违约风险基金,完善水产品供应链风险化解机制.     

长春市水生态系统服务价值核算及其动态变化

运用生态学和经济学方法进行了长春市水生态系统服务价值核算及其动态变化分析。结果表明,2010年长春市水生态系统服务总价值为17.80亿元,其中,资源功能价值(生物生产、水分供给、释放氧气)为10.42亿元,占58.54%;环境功能价值(污染净化、调蓄洪水、固定碳、养分积累、生物多样性保护)为6.55亿元,占36.80%;人文功能价值(旅游、健康)为0.83亿元,占4.66%。与1990年和2000年相比,长春市2010年水生态系统的资源功能价值所占比例升高,环境功能价值所占比例下降,人文功能价值所占比例升高。在城市发展过程中,不仅要科学利用水生态系统资源功能价值,还应进一步重视其环境功能价值和人文功能价值的实现。     

中国水产品对日本出口的商品结构实证分析

本文收集了近10年中国水产品对日本出口的贸易数据，利用分散度指数、结构变化指数以及区域显示性比较优势指数，对中国水产品出口到日本的商品结构进行实证分析，结果发现：1998～2007年，中国水产品对日出口的分散程度呈现出“先增高，后降低”的趋势；商品结构变化幅度呈现出“低-高-低-高”的变化趋势；中国深加工水产品（0371、0372）在日本市场具有很强的竞争优势；中国对日本出口额较大、竞争优势较强的水产品大多集中在日本进口额相对较小的水产品类别上。     

北京城市家庭水产品在外消费的影响因素分析

本文使用记帐式调查数据，采用Double—hurdle模型分析了北京城市居民家庭水产品在外消费及其影响因素。计量分析结果发现，收入与时间机会成本会显著增加城市居民家庭水产品在外消费的参与概率与消费数量。此外，家庭在外水产品消费的参与和消费决策还受到家庭人口结构与区域分布的显著影响。本文的研究结果对促进我国餐饮业与水产业的健康发展和相关政策的制定有重要意义。     

Aquatic resources and recreation behavior

While substantial effort has been undertaken to understand the consequences of industrial and agricultural uses for the environment, concern has also been expressed about its other uses, including recreation. Little is known about the relationship between recreational behavior and an environmental resource base. The present paper focuses upon participation in a specific outdoor recreation activity or activity‐cluster and dominant resource base where participation occurs. Resource bases identified were river, lake, ocean, swamp/marsh, forest/mountain, range/ farm and city/town. Emphasis is placed upon aquatic environs and participation in water‐based recreation. Water activities constituted from 14–30 percent of all outdoor activities taking place at those resource bases identified. Aquatic environments provided the resource base for 38 percent of all recreation participation events, water‐ and non‐water based, occurring during one reporting period. While participation in water‐based activities requires a water resource, the array of participation patterns reported suggests that resource bases defined as recreation places provide a wide range of opportunities for non‐resource‐dependent recreation activities. One conclusion is that resource bases cannot be distinguished by the recreation activities occurring on them. Resource bases in fact facilitate a wide range of recreation activities, some holding little direct connection with the resource base, nor are the conditions of the resource sufficient to predict behavioral outcomes.     

浅论水利与水产

本文在正确认识水利和水产关系的基础丰，提出安徽省桐城市水利和水产两部门之间的一些问题和相应对策。     

浅谈水生植物对生活污水的净化作用

本文探讨水生植物对生活污水的净化作用,它主要有沉降悬浮物、吸收营养物质、吸收重金属等直接作用和为根际提供氧气使微生物有效降解有机物的间接作用等。为建立人工生态系统治理生活污水提供科学参考。