共查询到20条相似文献，搜索用时 218 毫秒
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植物配置是景观设计中非常重要的组成部分,但是在许多现代景观与园林设计中,植物配置大多是生搬硬套的模式化设计,缺乏美感.文章论述植物配置在园林设计中的作用与意义,从基于美学的形式美原则与人文情感方面进行探讨如何进行植物配置.在此基础上科学合理搭配植物种植,并因地制宜,结合低干预原则对植物配置进行规划设计. 相似文献
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爬山虎属植物利用研究 总被引：9，自引：0，他引：9
爬山虎属植物属于系葡萄科系多年生木质大藤本攀缘植物,全世界约有15种.爬山虎属植物生有粘性吸盘因此可以攀缘岩石、峭壁和墙壁等.本属植物适宜生活在阴湿的环境条件下,但是也不畏惧强烈的阳光.本属植物能够普遍生存于中国大部分土壤贫瘠、寒冷、干燥的恶劣生活环境中,若条件稍好生长则更加良好.本文对爬山虎属植物基本生物学性质以及爬山虎的具体生物学特性进行了描述,同时对国内外该属植物的研究状况进行了综述总结,其中重点叙述了爬山虎和五叶爬山虎的实际应用情况以及介绍了爬山虎及其它爬山虎属植物可以广泛应用于城市垂直绿化、绿化荒山以及治理风沙地中解决饲养家畜和绿化矛盾等用途并对该属植物的医药和食品研究应用前景提出了建议. 相似文献
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对武汉大学珞珈山全面勘查,将该区域内的藤蔓植物进行调查、鉴定和统计,初步确认的藤蔓植物有37科86种(品种).同时对藤蔓植物在校园绿化中的使用形式作了简要论述,由此发现藤蔓植物在环境绿化中还有很大的发展空间. 相似文献
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本文通过综合30多年来国内外在菌根植物抗旱性研究方面的成就,介绍了干旱条件下AM提高植物抗旱性的相关生理生化指标.综述了AM真菌与水分的关系,当土壤水分长期处于亏损状态,虽不利于植物的生长,但对菌根侵染和菌丝发育影响不大.干旱逆境条件下,AM真菌能够促进植物的生长、改善植物水分状况、调节物质的变化、提高苗木成活率、降低植株萎蔫系数.并探讨了AM真菌提高植物抗旱性的可能作用机制:一是菌丝的直接吸收;二是改善植物的矿质营养;三是提高酶活性,改变激素平衡.在此基础上,对AM真菌的研究前景进行了概括,为AM真菌在干旱地区的应用提供理论依据. 相似文献
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负氧离子对在空气中起到净化空气的作用,同时负氧离子的存在让人体更为舒适,生活更为健康.空气中的负氧离子由植物产生,不同的植物以及植物的不同配置对空气中负氧离子含量均有影响.采用实验手段研究了北京地区夏季城市绿化带与空气负氧离子含量的关系,包括负氧离子含量的城郊变化,不同植物配置对负氧离子含量的影响以及负氧离子含量的日变化等,并对结论进行一定探究. 相似文献
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通过对野外调查资料和相关文献资料的分析,共确定东北地区外来入侵植物23科95种.在综合分析前人建立的外来入侵物种风险评估方法的基础上,结合东北地区外来入侵植物的实际情况,建立东北地区外来入侵植物的风险评估体系.通过对东北地区外来入侵植物进行风险评估,确定风险等级为A的植物25种,风险等级为B的植物53种,风险等级为C的植物17种.针对各风险等级的外来入侵植物提出防治对策. 相似文献
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Spherical and non-spherical wax microparticles are generated by employing a facile two-step droplet microfluidic process which consists of the formation of molten wax microdroplets in a flow-focusing microchannel and their subsequent off-chip crystallization and deformation via microdroplet impingement on an immiscible liquid interface. Key parameters on the formation of molten wax microdroplets in a microfluidic channel are the viscosity of the molten wax and the interfacial tension between the dispersed and continuous fluids. A cursory phase diagram of wax morphology transition is depicted depending on the Capillary number and the Stefan number during the impact process. A combination of numerical simulation and analytical modeling is carried out to understand the physics underlying the deformation and crystallization process of the molten wax. The deformation of wax microdroplets is dominated by the viscous and thermal effects rather than the gravitational and buoyancy effects. Non-isothermal crystallization kinetics of the wax illustrates the time dependent thermal effects on the droplet deformation and crystallization. The work presented here will benefit those interested in the design and production criteria of soft non-spherical particles (i.e., alginate gels, wax, and polymer particles) with the aid of time and temperature mediated solidification and off-chip crosslinking. 相似文献
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蜡在油层条件下通常以溶解态存在,然而在开采过程中,含蜡原油沿着油管上升,随着压力不断降低,以及轻质组分的不断逸出,当原油接触到一个温度低于临界浊点的表面时,即出现蜡沉积。蜡沉积的机理有若干种,其中占主导地位的是蜡分子向冷表面（管壁）分子的扩散作用和已经结晶的蜡的剪切扩散作用。蜡晶呈薄片状,并形成固态的三维网络,故蜡晶结构在一定温度下,有一定的牢固性,结在管道中,会造成原油流动阻力增大,直接影响产量和能耗,严重时会造成停产,故清防蜡是维持正常开采及输送的必要措施。 相似文献
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BackgroundLiquid wax esters are widely used in cosmetic as well as pharmaceutical and other industries. The demand of organic and natural products is increasing nowadays. Coconut oil contains benefit fatty acids and has been mainly used for oil-based and moisturizer products. Liquid wax esters from coconut oil and unsaturated fatty alcohol can be synthesized by enzymatic reaction; and it is interesting for using as an alternative natural ingredient in these industries.ResultsOptimal condition for coconut oil based wax ester synthesis by immobilized lipase EQ3 was 10 U of enzyme, temperature at 30°C and molar ratio of coconut oil to oleyl alcohol at 1:3 (mol/mol) (0.33X) dissolved in isooctane for 12 h, while for Lipozyme RM IM optimal condition was 10 U of enzyme, temperature at 45°C and oil/alcohol molar ratio at 1:3 (0.33X) dissolved in isooctane for 3 h. Percentage of wax esters synthesized by both lipases reached more than 88%. Both immobilized lipases catalyzed high yield of wax esters within the 2nd batch; after that, the immobilized lipases showed reduced activity and synthesized < 60% of wax esters from the 3rd to 5th batch. The main composition of wax esters was ~ 48% oleyl laurate with 10% degradation at ~ 250°C.ConclusionsThe liquid wax ester synthesis by commercial Lipozyme RM IM had higher effect than immobilized lipase EQ3, but both catalysts were stable within 2 batches in the optimum condition. The characteristic properties of wax esters showed potential for use as components in cosmetics and skin care products.How to citeUngcharoenwiwat P, H-Kittikun A. Enzymatic synthesis of coconut oil based wax esters by immobilized lipase EQ3 and commercial lipozyme RMIM. Electron J Biotechnol 2020;47. https://doi.org/10.1016/j.ejbt.2020.06.005 相似文献
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Microfluidic paper-based analytical devices (μPADs) are widely used for performing diagnostic assays. However, in many assays, time-delay valves are required to improve the sensitivity and specificity of the results. Accordingly, this study presents a simple, low-cost method for realizing time-delay valves using a color wax printing process. In the proposed approach, the time-delay effect is controlled through a careful selection of both the color and the saturation of the wax content. The validity of the proposed method is demonstrated by performing nitrite and oxalate assays using both a simple two-dimensional μPAD and a three-dimensional μPAD incorporating a colored wax-printed timer. The experimental results confirm that the flow time can be controlled through an appropriate selection of the color and the wax content. In addition, it is shown that nitrite and oxalate assays can be performed simultaneously on a single device. In general, the results presented in this study show that the proposed μPADs provide a feasible low-cost alternative to conventional methods for performing diagnostic assays. 相似文献
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针对汽车发动机冷却液循环系统中的节温器,应用形状记忆合金节温器取代原来使用的石蜡节温器,形状记忆合金节温器的温控驱动元件采用TiNi形状记忆合金制作,并将其记忆动作温度通过相应的热处理调节至发动机冷却液温度的变化范围,用以驱动节温器主副阀门完成对发动机冷却液大小循环的控制。 相似文献
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通过借鉴橡胶、塑料等其它化工行业表面改性的方法,试用石蜡、硅油、硬脂酸、钛酸酯复合型偶联剂等做表面改性剂,对炼钢过程铁水预处理用脱磷剂石灰粉进行改性处理,对比测试改性效果,确定工艺路线和改性剂的选择,解决了太钢二炼钢厂铁水预处理过程中的石灰粉剂堵枪、粘结料罐壁的难题,达到了理想的效果. 相似文献
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Nidhi Gupta Ramesh Kandimalla Kumari Priyanka Gagandip Singh Kiran Dip Gill Surjit Singh 《Indian journal of clinical biochemistry : IJCB》2014,29(1):69-73
Dietary and lifestyle factors have been shown to have a profound effect on paraoxonase-1 (PON1) activity. Cigarette smoke has been shown to inhibit its mass and activity where as resveratrol has been shown to enhance it. We exposed hepatoma derived cell line (HepG2) to resveratrol and nicotine in varying doses and measured PON1 enzymatic activity and PON1 gene expression. In addition, total protein content of HepG2 cells was also measured. Resveratrol in a dose of 15 μmol/l or above significantly increased the PON1 enzyme activity (p > 0.001) where as nicotine in a dose of 1 μmol/l or higher significantly reduced it (p < 0.05). The resveratrol in this dose also enhanced the PON1 gene expression whereas nicotine decreased it as compared to controls. However, the protein conent of cells was not changed suggesting that they were not cytotoxic in the doses used. Till date the antioxidant vitamins have shown disappointing results against LDL oxidation and cardiovascular protection. However, the effect of resveratrol on PON1 gene expression and activity was significant, suggesting increase in PON1 activity and enhanced gene expression may be its alternative mechanism for offering protection against cardiovascular disease and may be an potential pharmacological agent which can be used for this. 相似文献
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Nakano T Itoyama T Yoshida K Sawada Y Ikeda S Fukuda T Matsuda T Negoro M Arai F 《Biomicrofluidics》2010,4(4):46505
We proposed and fabricated multiscale transparent arteriole and capillary vessel models with circular cross sections of 10-500 μm using photolithography. The circularities of the fabricated 10, 50, and 500 μm diameter microchannels were 84.0%, 61.5%, and 82.3%, respectively. Next, we connected these different models to realize a circulation type blood vessel model simulating arteriole networks. We proposed a novel connection method using an intermediate connector made of wax, which we used to connect these models to make a circulation model. In flow experiments, the fabricated models showed no leakage and circulation models with seamless connections were achieved. 相似文献