浅议我国水产品物流的发展

水产品物流的发展关系到水产业现代化的进程、水产业竞争力的提高和农民收入的增加.本文在明确水产品物流内涵的前提下,重点分析了我国水产品物流的发展现状和面临的问题,并在此基础上,结合实际提出了加快我国水产品物流发展的若干对策.     

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。     

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.     

Response of montane meadow vegetation after two years of streamflow augmentation

Changes in montane meadow vegetation were examined in a previously ephemeral drainage that received flow augmentation as a mitigation measure for a transbasin diversion in southeastern Wyoming. After two years of elevated surface and groundwater levels, the herbaceous vegetation shifted toward more water-tolerant species. Dry meadows became like moist meadows, moist meadows became more like moist-wet meadows, and moist-wet meadows became more like wet meadows. Sedge (Carex spp.) biomass increased from 337 to 456 g m^?2 in the wet meadows, while tufted hairgrass (Deschampsia cespitosa) biomass decreased from 18 to 3 g m^?2 in the moist-wet meadows. Slimstem reedgrass (Calamagrostis neglecta) remained unchanged in the meadows with shallow standing water, but increased from 17 to 88 stems m^?2 in the dry meadows with an elevated water table. Bare ground also increased as much as 31 per cent in the meadows without a defined drainage channel.     

影响岩质路堑边坡表层土稳定性因素的敏感度分析

针对渝怀铁路鱼嘴车站岩质路堑植被边坡,采用直剪切试验获得边坡表层绿色防护层的物理力学参数。在此基础上,选取5个影响边坡表层土稳定性的因素（坡度、土层厚度、重度、粘聚力、内摩擦角）,采用数学及数理统计的方法进行敏感度分析,得出各影响因素的敏感度顺序为内摩擦角〉坡度〉重度〉土层厚度〉粘聚力,分析表明绿色防护层的内摩擦角是控制其稳定性的主控因素。     

漕河渡槽深厚卵石层钻探取芯样技术探讨

对深厚卵石层钻探完整取芯样问题一直是水电勘探中的一大难题,近十年来由于采取了SM植物胶金刚石钻进工艺,岩芯采取率和钻进效率都有一定的提高;随着实践经验的积累和技术参数、配制方法的不断调整,此钻进工艺得到了不断完善.槽河渡槽是南水北调中线工程河北省段最大的建筑物,河床段卵石层深厚且含砂量小,钻探取样难度极大;就漕河渡槽深厚卵石层勘探中钻具的选用、技术参数的选择及植物胶配制方法、注意事项、取芯样技术进行了较详细的叙述并进行了总结,可供以后类似地层勘探时参考.     

Decision-making in Water Management under Uncertainty

Decision-making in water management requires the delivery of accurate scientific information. However, the task is challenging under the situation where a large amount of uncertainty exists in the available information (e.g., model outputs). This paper investigates the effect of uncertainty on the ranking of options in water management. Different methods for ranking the management options under uncertainty are reviewed and they account for only partial uncertainty information in model outputs. To consider the full uncertainty information, a new ranking procedure is proposed in this paper, which is capable of providing more information to decision makers and at the same time taking their opinions on uncertainty into consideration. The ranking is achieved by conducting pair-wise comparison of management options, on the basis of the risk defined by the probability of obtaining an unacceptable ranking and the mean difference in model outputs in pair-wise comparison. An application example is presented to illustrate the use of the proposed ranking approach. Furthermore, the sensitivity of management option ranking to different ranking methods and to model uncertainty is also investigated.     

HYDRAULIC RESISTANCE OF SUBMERGED VEGETATION RELATED TO EFFECTIVE HEIGHT

Submerged vegetation has a significant impact on water flow velocity. Current investigations include the impact through adding drag resistance and increasing bottom roughness coefficient, which cannot elucidate the characters of real submerged vegetation. To evaluate the effects of submerged vegetation on water currents at different velocities, a laboratory experiment was conducted using three kinds of vegetations. The effective heights of these vegetations on varying flow velocities were evaluated. An equation describing the relationship between the normalized resistance of the submerged plants and the Reynolds number based on the plant effective height was then established and used to calculate the hydraulic resistance parameters of submerged plants in different stages of growth.     

淮河流域水生态服务功能类型研究

明确区域水生态特征与水生态服务功能类型是水生态保护工作的基础和前提。在分析淮河流域水生态问题的基础上,结合流域内生态服务功能空间分异规律,参考现有生态服务功能的概念、内涵、分类等研究,提出淮河流域二级水生态服务功能体系。针对3类一级水生态服务功能和7种二级功能,分别给出其具体释义与简要特征描述。对淮河流域水生态特征的辨识与水生态服务功能的划分,可为流域生态建设与水资源保护奠定理论基础。