水生植物应用问题多

随着水生植物在园林中应用的日益广泛,暴露的问题也越来越多.本文就水生植物的名称规范、种植密度、种植季节、规格标注、种植土、常水位和水深适应性等问题与读者讨论、交流.     

太原市河道沿线绿地空间设计初探

通过对北沙河河道沿线绿地空间的研究,在尊重滨水区特有自然规律的前提下,以开发滨水区景观为主导,探索了河道空间发展的有益模式,对北沙河河道沿线绿地空间设计方法进行了详细阐述,以带动河道周边区域的发展,真正实现对城市中宝贵资源的充分利用。     

浅谈小河道护岸绿化种植施工

河道生态景观是城市中最具生命力与变化的景观形态,能满足人们回归自然的渴求,因此,以生态景观造景为主的河道景观是现代城市河道建设的重点。本文结合广州永和河两岸绿化设计及种植施工进行了探讨。     

水生植物在复地艺墅居住区绿化中的应用

介绍了复地艺墅生态别墅居住区中水生植物的配置、所选用的几种水生植物的种植密度;分析了水生植物在本工程应用中存在的问题,并提出建议。经合理配置水生植物后,柔化了水体景观,改善了水性。     

城市河道工程规划方法初探

从城市河道工程规划的视角出发,分析了如何在城市规划工作中最大程度地保护水体资源,形成有效率的用地水系格局,从而维系宁波市江南水乡的特色。     

杭州园林水景的水生植物调查及其配置应用

经实地调查,目前在杭州主要园林水景中已应用的水生植物共有42种.在应用现状基础上,从水生植物在不同水体环境中的应用特点出发,并结合景观生态学原理,初步探讨了水生植物在园林水景设计中的应用特点和在不同水体环境中的生态配置模式.     

水生植物在河道生态修复中的应用研究

以河道景观建设工程项目为研究对象,对工程概况及项目施工要求进行阐述,并概括了水生植物在水生态修复中的影响因素及具体作用,介绍了植物品种选择的原则及具体施工要点,分析了河道生态修复工程实践后的思考及维护管理。     

杭州的河道景观与文化传承

人类对水的认识,不仅要用自然科学的方法去研究,而且要用社会科学的观点去丰富.中外游客每每提到杭州,都会想到波澜壮阔的钱江潮,如诗如画的西子湖,历史悠久的大运河.本文要说的是,请别忘了还有纵横交错、民生以赖的河道,它的产生、发展,它的现在、未来,都与杭州特有的钱江、西湖、运河血脉相通,共同哺育这座美丽的山水城市.     

城市湿地公园水生植物应用初探

作为湿地与公园的复合体,湿地公园在城市的发展中起着十分重要的作用。在在保护中利用,在利用中保护的生态思想的指导下,强大的生态功能和社会功能使城市湿地公园的价值得到社会的广泛认可。其中湿地公园水生植物在生态效益和景观效益上起着不可替代的作用,科学合理的应用水生植物,不仅可以净化湿地中的水体,还可以提升湿地公园的景观效果。旨在从水生植物配置和选择原则角度,为湿地公园水生植物景观营造提供思路。     

宁波市中塘河支流黑臭河道治理与生态修复

中塘河支流(世纪花园小区段)为宁波市内一条黑臭河道,通过曝气造流、种植水生植物、构建水生微生物种群等措施对该河道进行深度治理。运行结果表明,上述工程措施能够有效去除水体中的有机物、氨氮、总磷等污染物,增加水体溶解氧量和透明度,同时需要环保监管与定期运行管理。应用生态修复技术治理城市黑臭河道,在技术上是切实可行的,具有良好的应用前景和社会、环境效益。     

A preliminary note on the sequential decomposition of pectin by aquatic bacteria

In a eutrophic lake, an inverse relationship was observed between total aerobic heterotrophic bacteria and their pectolytic share which consisted mainly of Flavobacterium-Cytophaga species. When grown in a medium containing pectin and yeast extract as organic compounds pure cultures of the most abundant type of this bacterial group showed a diauxic characteristic of growth. Short time before entering the first lag phase of growth, production of pectolytic enzymes increased until the end of the second log phase of growth. This phenomenon may be due to the mechanism of a catabolic repression and derepression.     

Phosphorus in primary aquatic plants

As with other organisms, phosphorus is an essential element for aquatic plants. It is a component of molecules such as the nucleic acids and adenosine triphosphate (ATP) involved in the vital processes of enzyme synthesis and energy transfer and its compounds play a basic role in the mechanisms of photosynthesis by which these plants act as the primary producers of organic matter in aquatic environments. In the plant it is about eighth in order of abundance among the elements whereas in cosmic abundance it lies fifteenth and among the nutrient elements dissolved in natural waters it is often in relatively shortest supply. These facts lead to the conclusion that the concentration of available phosphorus compounds controls the growth of plants in aquatic habitats. This generalization has a certain validity, as Vollenweider (1968), for example, has shown, but because of the complexities in the utilization and metabolism of phosphorus by plants apparent exceptions are frequent and those who have sought to controvert it have had no difficulty in finding data to support their case (see Schindler, 1971).In this review attention will be concentrated on the relations of algal growth to phosphorus supply. This seems justified because not only are algae the predominant plants in aquatic habitats but little research appears to have been carried out specifically on phosphorus uptake and metabolism in higher aquatic plants. Presumably the latter are generally similar to terrestrial flowering plants in their relations to phosphorus and the information given in works on plant physiology applies. No attempt can be made to review completely the literature on the phosphorus metabolism of algae. For further references the reviews of Kuhl (1962, 1968) should be consulted.     

个体化预测梗阻性乙状结肠癌患者预防性肠造口回纳的风险Nomgram模型的建立

目的 探讨梗阻性乙状结肠癌患者预防性肠造口回纳的风险并建立Nomgram模型。方法 选取肠造口的乙状结肠癌患者104例，根据肠造口回纳时间分为延迟回纳组40例，正常回纳组64例。分析数据并建立相关Nomgram预测模型。结果 两组患者在肿瘤距肛缘的距离、术后辅助化疗、新辅助治疗、吻合口狭窄和吻合口漏方面的差异具有统计学意义。肿瘤距肛缘的距离、术后辅助化疗和吻合口漏是肠造口回纳延迟的独立危险因素。建立列线图模型，并进行验证，C-index指数为0.740(95%CI:0.691～0.789)。结论 肿瘤距肛缘的距离、术后辅助化疗和吻合口漏是影响梗阻性乙状结肠癌患者预防性肠造口回纳的独立危险因素；所建列线图预测模型具有良好的精准度和区分度。     

A preliminary investigation of water usage behavior in single-family homes

As regional drought conditions continue deteriorating around the world, residential water use has been brought into the built environment spotlight. Nevertheless, the understanding of water use behavior in residential buildings is still limited. This paper presents data analytics and results from monitoring data of daily water use (DWU) in 50 single-family homes in Texas, USA. The results show the typical frequency distribution curve of the DWU per household and indicate personal income, education level and energy use of appliances all have statistically significant effects on the DWU per capita. Analysis of the water-intensive use demonstrates the residents tend to use more water in post-vacation days. These results help generate awareness of water use behavior in homes. Ultimately, this research could support policy makers to establish a water use baseline and inform water conservation programs.     

Some ecological observation on the decomposition of periphytic algae and aquatic plants

Stigeoclonium tenue, Chlamydomonas sp. and Chlorella sp., which are dominant periphytic algae in a shallow river (Tama-gawa, running through the Metropolitan area of Tokyo) were subjected to dark- and aerobic-decomposition tests using Selenastrum capricornutum as control. The decomposition of aquatic plants,Potamogeton crispus and Potamogeton pusillus which become dominant in the river mid- and downstream during summer was also studied. Successions of protozoa and smaller metazoa were noted from the decomposition tests.Regardless of the species of algae and aquatic plants studied the decomposition rate could be simulated as the 1st-order reaction if the refractory fraction, f of each organism was used as the datum of assessment. The value of f was roughly from 0.2 to 0.4, also irrespective of the organisms examined. The rate constant, k thus assessed extended from 0.08 to 0.2 day ⁻¹ at 20°C.Phosphorus and nitrogenous compounds regenerated into liquid (decomposer) amounted at 50th day of decomposition test to a level of 50 to 75% of that retained initially with the cells. Thus far, the seriousness of secondary pollution due to decomposition of periphytic algae and aquatic plants was pointed out. Lastly, the significance of removing nutrients from effluent of the wastewater treatment was demonstrated.     

水生植物在湿地生态恢复中的应用研究

从阐述水生植物的概念与种类出发,分析了水生植物的应用价值,提出了水生植物在湿地生态恢复中的应用建议,从而有效发挥水生植物在湿地生态系统中的主体作用,促进良性的湿地生态演替和自循环,提升湿地生态系统的稳定性。     

Testing the potential of aquatic plants to treat abattoir effluent

The potential of 3 genera of emergent aquatic plant species (Typha spp, Phragmites and Scirpus) to ameliorate effluent from a poultry abattoir was evaluated in an experimental trench system. Three plastic-lined trenches containing Typha (two species), Phragmites and Scirpus plants in a gravel substrate were constructed near the abattoir. Effluent was allowed to percolate, with retention times of 2.7–3.6 days, through the trenches. The quality of the inflowing and outflowing effluent was compared by a regular sampling program for suspended solids, conductivity, turbidity, pH, dissolved oxygen, Na, K, Cl, N and P concentrations. The importance of water loss by evapotranspiration was investigated.Comparing the inflow to outflow, each trench system successfully reduced the suspended solids (83–89%), turbidity (58–67%), total nitrogen (14–56%) and total phosphorus (37–61%) concentration of the effluent while maintaining an acceptable pH and in the case of the Phragmites and Scirpus systems oxygenating the anaerobic inflow. Conductivity increased in the Typha and Phragmites trenches. If a correction is made for water lost by evapotranspiration, the three experimental trench systems reduced the nitrogen (42–75%), phosphorus (68–79%), sodium (7–34%), potassium (9–56%) content of the effluent. The chloride content of the effluent in the Phragmites system was increased by 15% but was reduced by 31 and 53% in the Typha and Scirpus systems respectively. The results from this initial experiment give an indication of the relative abilities of the three plant systems to treat the wastewater from the abattoir. Of the three, that containing the Scirpus was superior.     

A preliminary investigation of the metal content of certain children's sweet wrappers

An investigation of the lead, cadmium and copper contents of certain sweet wrappers has been carried out in response to a number of reports by other workers on the metal content of American confection wrappers. In this study the wrappers analysed were from some of the most popular sweets consumed by young children in the U.K. This selection was made as it is not uncommon for children to suck the sweet wrappers as well as the sweets contained therein. No significant levels of any of the metals examined were found and it is apparent that no hazard exists from this source at the present time.