Possibilities and problems with the use of models as a communication tool in water resource management

Politicians and policy-makers, as well as modellers, often nurses an expectation that model derived results is an objective source of information that can be used to support decisions. However, several prerequisites have to be dealt with in order to ensure that models can be used as legitimate and efficient tools in water resource management. Based on empirical material from recent studies on the use of models in stakeholder dialogues, mainly focusing on catchment nutrient transport, two central problems are identified: (a) Models are laden with choices and thus depend on assumptions and priorities of modellers. (b) There are several factors that influence ability and willingness of stakeholders (as information recovers) to criticize or accept results of the modelling exercise. Recognized factors likely to influence stakeholders' acceptance of model derived results include issues at stake, stakeholders' ability to criticize model derived information, and their trust in the institutions that have developed or applied the used models. Identified prerequisites for successful use of models in integrated water resource management include: consideration of user relevance, awareness of and preparedness to handle constraints linked to communication of model-based results, transparency of used models and data and of involved uncertainties, mutual respect between experts and stakeholders and between involved stakeholder groups, a robust institutional network, and sufficient time for dialogues. Development and use of strategies for participatory modelling, based on a continuous dialogue between experts and stakeholders is recommended as a way to facilitate that the prerequisites for a successful use of models in water resource management are fulfilled.     

Equilibrium distribution of water in the two-phase system supercritical carbon dioxide–textile

When natural fibres are dyed in supercritical carbon dioxide, the addition of a small amount of water increases coloration. For a process design it is important to know how much water has to be added to obtain a desired humidity of both textile and carbon dioxide. In this work a thermodynamic model is proposed to calculate the distribution of water over the textile phase and the supercritical phase as a function of pressure and temperature. The phase equilibrium is described with Raoult's law for non-ideal fluids. The absorbed water in the textile is a condensed phase and is modelled here as a non-ideal liquid, using the NRTL-equation. The non-ideality of the supercritical phase is described by a solubility enhancement factor, a new equation derived from statistical thermodynamics. Although the model is applied to cotton, viscose, silk and wool, it can be used for all water absorbing textiles.     

核磁共振测井在致密含气砂岩中的应用

通过对核磁共振测井的T₂谱及其T₂截至值的合理选取，解释并获得了鄂尔多斯盆地西缘上古生界山西组、石盒子组致密砂岩储集层的总孔隙度、有效孔隙度、毛细管束缚水体积、可动水体积及渗透率等参数，据此预测的储集层孔隙结构特征与岩心分析测试结果很吻合。研究还发现，致密含气砂岩的T₂谱具有分布范围窄-中等，波形及差谱分析谱位置明显后移、分布中等、呈单峰的典型特征。结合常规测井资料，综合研究了致密砂岩储层特征及其含气层的测井响应。经测试验证，致密含气砂岩储层的核磁共振测井解释结果十分可靠，表明核磁共振测井可用于该区致密含气砂岩复杂储集层评价。     

空分设备氮水预冷系统改进

分析 6 0 0 0m3 /h空分设备原氮水预冷系统存在的问题及原因 ,将水循环由原制氧站大循环改为氮水预冷系统内部的自循环 ,只增加水换热器和蓄水器 ,效果明显。     

Excel二次开发在模拟水氡观测中的应用

尝试对Excel工作表进行二次开发,将其应用到台站模拟水氡观测工作当中,可以自动计算出模拟水氡观测的标定、季检结果,需要作图的还可以自动作图,杜绝了人工计算产生的不必要误差,减轻了劳动强度,实现了观测资料的数字化存档,对台站模拟水氡观测日常工作具有很大帮助。经吉林省地震局多个台站使用,Excel工作表自动计算结果与人工计算结果两者完全相符,效果良好。     

水压环形缝隙泄漏量的试验研究

在水压系统环形缝隙泄漏试验基础上，对圆柱形配合状态下的缝隙泄漏量进行了理论和试验对比研究，分析了两者的变化规律。得出的结果可以为水压元件的设计提供试验依据。     

Water vapor and oxygen permeability of wax films

The water vapor (WVP) and oxygen (O₂P) permeabilities of beeswax (BW), candelilla wax (CnW), carnauba wax (CrW) and microcrystalline wax (MW), formed as freestanding films, were determined. CnW and CrW both had small values for O₂P (0.29 and 0.26 g·m⁻¹·sec⁻¹·Pa⁻¹ × 10⁻¹⁴, respectively), which are less than half the value for high-density polyethylene and about a decade greater than the value for polyethylene terephthalate. O₂P values for BW and MW were about 6−9× greater than those of CnW and CrW. WVP of CnW was 0.18 g·m⁻¹·sec⁻¹·Pa⁻¹ × 10⁻¹², which is about one-half the value for CrW and MW and about one-third the value for BW. The WVP of CnW was somewhat less than that of polypropylene and somewhat greater than that of high-density polyethylene. Differences in permeabilities among the wax films are attributed mainly to differences in chemical composition and crystal type as determined by X-ray diffraction.     

淀粉丙烯酸接枝共聚吸水性树脂的研究进展

基于淀粉丙烯酸接枝共聚作为吸水性树脂具有环保和可生物降解的优良特性 ,目前 ,人们普遍关注的是如何提高其吸水性 ,抗温性 ,控制水份释放 ,压力下保水 ,以及电解液的吸收等。这些特性的改进将使产品的用途更为广泛 ,可以预见 ,淀粉丙烯酸接枝共聚作为吸水性树脂具有广阔的应用和发展前景。     

黄河海勃湾水利枢纽对西鄂尔多斯国家级自然保护区胡杨岛的影响分析

海勃湾水利枢纽的建设、运行将对西鄂尔多斯胡杨岛旅游区产生不可逆的影响。经调查分析,胡杨岛胡杨种群分布面积为2.31 hm~2,总株数约为1 800株;胡杨种群表现出增长型特征;胡杨林总生物量为95.43 t。海勃湾水利工程运行后胡杨岛的淹没历时延长,淹没水深、淹没面积显著增加,岛北部低矮位置甚至全年淹没。胡杨部分种子可能落入水中被水流携带,丧失了种子繁殖的条件。根蘖产生的不定芽在4—6月生长期也会浸在水下,不能完成无性繁殖。胡杨幼苗树不高于2.5 m,淹没后无法生存。水库淹没将岛上以陆生生态为主的生态系统演变成以水生生态为主的生态系统,原有的旅游功能将发生变化或丧失,须采取生态补偿措施,减免工程造成的生态影响。     

黄金峡水利枢纽工程大型水泵机组选型设计及运行调节研究

引汉济渭工程黄金峡水利枢纽是陕西省境内一项重要的大型跨流域调水工程,泵站装机容量和设计流量均为目前国内甚至亚洲在建和已建泵站之最,且调水过程复杂、调水流量分布范围宽广。在分析黄金峡泵站调度原则及运行方式的基础上,综合比较目前国内外大型泵站机组设计制造水平、枢纽建筑物及机电设备投资等因素,详细论证了大型单级单吸离心式水泵机组台数和性能参数的确定方法及其影响因素,并给出了黄金峡泵站机组选型设计的最优方案,同时论证了采用变频调节的必要性及其效果。研究结果可为大型调水泵站机组的选型设计提供参考。