5 resultados para Pilot Study

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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生物多样性的维持、监测、保育与恢复是生物多样性科学的核心研究内容( DIVERSITAS)。作为世界上典型的植被类型,常绿阔叶林以其丰富的生物多样性而倍受世人关注。我国的常绿阔叶林是全球分布面积最大,发育最为典型的常绿阔叶林,其分布区多为农业区,与长江流域的生态安全密切相关:伴随着人们的生产活动,生境的岛屿化与破碎化问题越来越突出,常绿阔叶林的合理保育问题和生态恢复问题已成为大家关注的焦点。本研究“常绿阔叶林恢复生态学研究初报”正是在这种背景下开展的,主要实验研究工作与结果如下: 1.系统综述了生态系统退化程度的诊断指标体系、途径与方法,绘制了生态系 统退化程度的概念模型,为恢复生态学研究和生态恢复实践提供参考。 2.固定样地的建立:为深入开展生物多样性与恢复生态学研究,本研究建立了一系列固定样地(常绿阔叶林固定样地、常绿落叶阔叶林固定样地、退化生态系统恢复与重建实验样地等),这些样地的建立为进一步深化研究奠定了坚实基础。 3.种群大小级结构特征:对栲树Castanopsis fargesii和油茶Camellia oleifera种 群大小级结构特征研究表明,栲树种群大小级结构(高度级和胸围级)呈弱双峰型分布,油茶种群大小级结构呈倒“J”型分布。对树木大小级划分标 准的比较研究表明划分标准的选择应基于研究目的和物种性质。作者认为应深入研究干扰特别是生境的岛屿化与破碎化对常绿阔叶林稳定性的影响。 4.种子扩散与种群维持:种子扩散是种群维持的一个关键阶段,而建群种的维持机制可在一定程度上反映群落的维持机理。对都江堰常绿阔叶林固定样地的主要建群种栲树种子扩散的研究表明,种子雨密度、种子在地上保留密度以及种子丢失状况是个动态过程,种子雨在2001年持续了约3个月的时间,种子年产量达到每平方米73.37个正常种子;研究发现栲树种子下落后能在地上保留一段相当长的时间(捕食者饱和现象“predator satiation"),这为种子萌发提供了更多的时间和机会,从而使得栲树种群能通过大年(the mast year)的高种子产量与捕食者饱和现象顺利完成自然更新;捕食者饱和现象有助于解释栲树的优势种群地位和稳定机制,以及对整个生态系统稳定性的贡献;作者提出了一个描述栲树种子扩散命运的概念模型,该模型表明种子雨与种子丢失的不同阶段是在不同程度上以不同方式贡献于栲树的自然更新。总之,栲树自然更新伴随着一个复杂的种子扩散过程。 5.光因子调控与生态恢复:光是影响植物生长的一个重要生态因子。研究了三种不同遮荫处理(100% PAR、40% PAR和22% PAR)对青冈Cyclobalanopsis glauca幼苗在亚热带弃耕地上的影响作用,两年的研究结果显示:青冈幼苗 可以在弃耕地上正常生长:两种遮荫处理(40% PAR和22% PAR)对青冈的萌芽和幼苗生长有正效应,并且22% PAR遮荫处理有明显的促进作用;本研究也说明了植物在不同的遮荫处理作用下有不同的生长策略。关于在生态恢复中如何利用光因素对植物生长的影响以及遮荫的复合效应问题值得深入研究。 6.种间关系与生态恢复:杂草竞争是植被恢复中的一个重要问题。对两种常绿阔叶树种(青冈和石栎Lithocarpus glaber)在不同坡位(坡上位、中位、下位)和有无地上杂草竞争的情况下的对比研究表明:不同物种在不同坡位,其幼苗生长对杂草竞争的反应是不同的;在坡上位和下位,除草处理能显著地提高青冈幼苗的田间保存率、苗高、基径和冠幅的生长,而在中位,除草处理的效果不显著;但是对于石栎来说,除草处理仅能显著地提高坡中位幼苗基径的生长量;研究说明了(地上)杂草竞争对植物生长的影响(程度)因物种而异,因而除草处理并不是对所有常绿阔叶树种的幼苗生长有促进作用,杂草竞争也不是一切常绿阔叶树种在弃耕地上建立与定居的障碍因子。作者建议在生态恢复实践中应根据具体情况选择除草与否,关于杂草竞争/除草在植被恢复中的作用值得进一步研究。

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Extract of Ginkgo biloba is used to alleviate age-related decline in cognitive function, which may be associated with the loss of catecholamines in the prefrontal cortex. The purpose of this study was to verify whether alpha-2 adrenergic activity is involved in the facilitative effects of extract of Ginkgo biloba on prefrontal cognitive function. Male Wistar rats were trained to reach criterion in the delayed alternation task (0, 25, and 50-s delay intervals). A pilot study found that 3 or 4 mg/kg of yohimbine (intraperitoneal) reduced the choice accuracy of the delayed alternation task in a dose and delay-dependent manner, without influencing motor ability or perseverative behaviour. Acute oral pre-treatment with doses of 50, 100, or 200 mg/kg (but not 25 mg/kg) of extract of Ginkgo biloba prevented the reduction in choice accuracy induced by 4 mg/kg yohimbine. These data suggest that the prefrontal cognition-enhancing effects of extract of Ginkgo biloba are related to its actions on alpha-2-adrenoceptors.

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一体化反应器由于投资少、占地小、管理运行方便等优点而备受青睐。但现有的一体化反应器大都适用于处理中低浓度废水,耐受负荷普遍偏低。本课题研制出新型高效的厌氧好氧一体化生物反应器,旨在通过反应器结构优化、高效微生物载体研制、配合高效微生物菌剂技术处理中高浓度有机废水,实现高效和低耗,降低设备造价,提高反应器运行稳定性。 首先开展了菌剂对废水的适配试验。采用15种不同的微生物菌剂,以葡萄糖配水、中药提取废水、啤酒废水、氨氮配水为基质,分别测定了微生物菌剂的耗氧速率和厌氧比产甲烷速率,以其为指标比较了各菌剂对废水的适配性。根据结果选择活性高的14#、8#、10#菌剂,在试验室进行了菌剂对废水的连续处理试验,取得良好的处理效果,为菌剂在厌氧好氧一体化生物反应器的小试、中试中的应用奠定了基础。 经小试研究后,又对厌氧好氧一体化生物反应器进行了处理发酵废水的中试研究。试验结果表明,反应器启动快,系统有机负荷2.72 kgCODm-3d-1时整个反应器去除率保持在84.5%~93.19%,在30多天内一次启动成功。冲击负荷试验中,系统总有机负荷最高可达到8.88 kgCODm-3d-1,系统去除率稳定在88.10%~96.88%,说明反应器处理效率高,抗冲击能力强。稳定运行期间,COD去除率可达90%以上,各项指标都能达到国家排放标准。 此外,对反应器配套系统高效菌剂、高分子复合颗粒载体进行了研究。结果显示,菌剂与反应器适配良好,各功能区形成了丰富、高活性的微生物,厌氧区颗粒污泥TS高达83.9 gL-1,VS/TS为56.9%~57.4%,比产甲烷活性为280~350 mLCH4 gvss-1d-1;好氧区固定化微生物TS高达1.921 gL-1,VS/TS为94.02~94.30%。对载体性能的研究表明,此高分子复合颗粒载体密度适中,易于流化,不易流失;粗糙多空,易于挂膜;且无生物毒害作用,稳定安全,是一种优良的生物载体。反应器各功能区对废水的降解过程分析,说明了反应器、菌剂、载体适配良好,在其协同作用下,实现了污染物的高效降解。 The integrated reactors were popular because of their characteristics such as little investment, small occupation of land, convenient of manage and running etc. But the present integrated reactors were mostly applied for treating wastewater of low concentration, the load tolerance was generally on the low side. A new type integrated anaerobic-aerobic bio-reactor was developed, which was conducted to treating organic wastewater of middle or high concentration by optimization of reactor structure, development of efficient microbe carrier and adaptation of high active microbial blends, to achieve high efficiency and low consume, reduce equipment cost, enhance running stabilization of reactor. The adaptability test of microbial blends on different wastewater was carried on firstly. Oxygen consumption rate and anaerobic specific activity of methane producing of 15 different microbial blends were measured separately taking glucose artificial wastewater, Chinese herb extracting wastewater, brewery wastewater and ammonia nitrogen artificial wastewater as substrate, by which the adaptabilities of different microbial blends to wastewater were compared. According to the results high active microbial blends 14#, 8# and 10# were selected and used in the continuous treatment of wastewater in the laboratory and had obtained good effect, which had laid a foundation for application microbial blends to small scale test and pilot test of integrated anaerobic-aerobic bio-reactor. After the small scale test, the pilot test of the integrated anaerobic-aerobic bio-reactor treating fermentation wastewater was carried on. The test results showed fast initiation of the reactor. When system organic load reached 2.72 kgCODm-3d-1the COD removal rate of the reactor was stable between 84.5%~93.19% and it initiated successfully in more than 30 days at a time. In the load shock test the maximum organic load of system could reach to 8.88 kgCODm-3d-1 and the COD removal rate could be stable between 88.10%~96.88% which indicated that the reactor was efficient for treating wastewater and had strong resistance to shock load. At stable running period the COD removal rate of the reactor was over 90% and each index of wastewater could reach to the national discharge standards. In addition, the high active microbial blends and the macromolecule compound granule carrier, the matching system of the reactor was studied. It showed that the microbial blends adapted well to the reactor and abundant and high active microbes were formed in each functional field. The TS of granule sludge in anaerobic field was as high as 83.9 gL-1, the VS/TS was 56.9%~57.4%, the specific activity of methane producing was 280~350 mLCH4 gvss-1d-1. And the TS of immobilized biological granule was as high as 1.921 gL-1, the VS/TS was 94.02%~94.30%. Study on the carrier showed that the self-made macromolecular compound granule carrier was moderate of density, easy of fluidization, unease of running off, rough and porous, easy of films fixation, no bio-toxic, stable and safe, was a kind of superior carrier. Analysis of degradation process in each functional field confirmed the reactor, microbial blends and carriers were in good adaptation and wastewater was decontaminated by their cooperation.

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依据定位观测数据,对紫色土丘陵区农用地土壤水分的动态变化规律进行了初步研究。结果表明,该区农用地土壤水分的季节变化主要受降水、蒸发和土地利用状况的影响,呈现出明显的三峰三谷型;垂直梯度变化由于受降雨入渗分布与土壤水分向上蒸发的综合作用,基本表现为增长型。并利用标准差和变异系数对土壤水分的垂直梯度变化进行了具体描述和层次划分。最后,通过分析该地区典型农作物及其不同栽培方式对农用地土壤水分的影响,认为优化农作物栽培方式是提高紫色土丘陵区农用地土壤水分利用效率和减少水土流失的有效途径。