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31.
艺术性花园展是以推动园林艺术探索与发展、向公众普及园林艺术思想与应用为主要目的一类园林展。当代艺术性花园展与当代园林艺术在不断相互启发与促进的过程中逐渐发展成熟,对我国现阶段园林展的举办具有积极的借鉴意义。通过对外国艺术性花园展与展览花园的历史发展研究,系统介绍了世界范围内主要的艺术性花园展,深入分析了艺术性花园展及展览花园的特征,并以肖蒙花园节与梅蒂斯花园节为例介绍了艺术性展览花园主要的五种表达方式。  相似文献   
32.
高耐磨炉黑填充粉末丁腈橡胶的制备及性能   总被引:3,自引:1,他引:3  
研究了利用高分子树脂凝聚包覆法制备高耐磨炉黑填充粉末丁腈橡胶的制备过程及其影响硫化胶物理机械性能的因素。结果表明,当分散剂/包覆剂(质量比)为4/6或10/4时,粒径不大于0.90mm的粉末丁腈橡胶粒子的质量分数为100.0%,相应硫化胶的物理机械性能达到块状丁腈橡胶硫化胶的。高耐磨炉黑填充粉末丁腈橡胶硫化胶的物理机械性能极大地依赖于高耐磨炉黑粒子在基体橡胶中的分散程度及其与基体黏结的紧密性。  相似文献   
33.
腐殖酸-聚丙烯酸表面交联吸水性树脂的合成与性能   总被引:9,自引:0,他引:9       下载免费PDF全文
初茉  朱书全  李华民  黄占斌  邹力壮 《化工学报》2005,56(10):2004-2008
将交联剂N,N′-亚甲基双丙烯酰胺溶于甲醇溶液制成表面处理液,通过表面交联反应将磺化腐殖酸(HA)与聚丙烯酸(PAA)结合,制得一种适合于农林领域应用的腐殖酸-聚丙烯酸高吸水性树脂(HA-PAA).研究了表面处理液浓度、交联剂用量和腐殖酸量对HA-PAA吸水性能的影响规律和吸水机理,以及产物在沙土中的保水性能,并通过扫描电镜分析了HA-PAA的表面结构.研究结果表明,当含有10% HA时,HA-PAA耐电解质性能良好,吸水性能最佳;当沙土中添加0.2%的HA-PAA时,可明显改善沙土的贮水、保水性能.HA-PAA作为农林领域用保水剂,可发挥抗旱保墒和促进植物生长的双重作用.  相似文献   
34.
Bananas and plantains (Musa spp.) are a staple food for millions of impoverished people and as such are an important source of vitamins and micronutrients. To evaluate the potential of Musa spp. to meet dietary micronutrients requirements, we have screened 171 different genotypes for fruit provitamin A carotenoids (pVACs) contents, and a subset of 47 genotypes for macro- and micro-mineral (iron and zinc) contents using standardised sampling and analytical protocols. The results indicate that there is substantial variability in mean fruit pulp pVACs contents between cultivars, and that cultivars with a high fruit pVACs content are widely distributed across the different genome groups but only at a low frequency. The introduction of such high pVACs cultivars has much potential for improving the vitamin A nutritional status of Musa-dependent populations at modest and realistic fruit-consumption levels. In contrast, fruit pulp mineral micronutrient contents (iron and zinc), were low and showed limited inter-cultivar variability, even for genotypes grown under widely-differing environments and soil types. Results are discussed within the framework of the development of strategies to improve the nutritional health and alleviation of micronutrient deficiencies within Musa-consuming population groups.  相似文献   
35.
Takashi Nakai and Toshinari Tanaka of the Forestry and Forest Products Research Institute in Japan present the results of tests, using the easy handling and reasonable cost technique of fundamental vibration frequency measurement, on larger than usual cross‐sections. Modulus of elasticity measurements showed this method to have high possibilities for stress grading, overcoming the size limitations of existing commercial equipment at the saw mill or lumber yard. This paper was first presented at CIB Working Commission W18a in Vancouver in September 1988.  相似文献   
36.
Performance-based building regulation: current situation and future needs   总被引:1,自引:0,他引:1  
Although performance-based building regulations are in use or under development in numerous countries worldwide, there remain significant challenges in adequately identifying and defining performance, in understanding and addressing diverse societal expectations, and in establishing robust performance-based regulatory systems. These challenges become intensified as the building construction market becomes increasingly global, with the resulting expectation that building regulatory instruments remain valid across borders and do not create barriers to trade, while at the same time address local and national needs without compromising local cultural and societal norms. Many of these issues are just now beginning to be explored, and there is significant opportunity and need for future research and development in these areas.  相似文献   
37.
38.
How can the physical design of the workplace enhance collaborations without compromising an individual's productivity? The body of research on the links between physical space and collaboration in knowledge work settings is reviewed. Collaboration is viewed as a system of behaviours that includes both social and solitary work. The social aspects of collaboration are discussed in terms of three dimensions: awareness, brief interaction and collaboration (working together). Current knowledge on the links between space and the social as well as individual aspects of collaborative work is reviewed. The central conflict of collaboration is considered: how to design effectively to provide a balance between the need to interact and the need to work effectively by oneself. The body of literature shows that features and attributes of space can be manipulated to increase awareness, interaction and collaboration. However, doing so frequently has negative impacts on individual work as a result of increases in noise distractions and interruptions to on-going work. The effects are most harmful for individual tasks requiring complex and focused mental work. The negative effects are compounded by a workplace that increasingly suffers from cognitive overload brought on by time stress, increased workload and multitasking.  相似文献   
39.
The major problem with using standard first-order logic as a basis for knowledge representation systems is its undecidability. A variant of first-order tautological entailment, a simple version of relevance logic, has been developed that has decidable inference and thus overcomes this problem. However, this logic is too weak for knowledge representation and must be strengthened. One way to strengthen the logic is to create a hybrid logic by adding a terminological reasoner. This must be done with care to retain the decidability of the logic as well as its reasonable semantics. The result, a stronger decidable logic, is used in the design of a hybrid, decidable, logic-based knowledge representation system.  相似文献   
40.
The main goal of this work is to study the multiple material flows in side-by-side (SBS) tape casting and analyze the influence of the different material properties, i.e. the density and the viscosity, on the interface between the fluids, since this is highly important for the efficiency of a graded configuration of the magnetocaloric materials. The Newtonian flow behavior with relatively high viscosity is assumed for each fluid and used in the simulation with a commercial CFD code (ANSYS FLUENT). The results show that the density difference does not affect the interface between the adjacent fluids, whereas the viscosity of the fluids plays the most important role in the behavior of the interface. Moreover, increasing the viscosity difference of the adjacent fluids, Δμ, leads to increasing the diffusive region between them. However, this can be counteracted by decreasing the velocity by the substrate.  相似文献   
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