35 research outputs found

    Effects of mowing plus waterlogging on germination and seedling growth of Spartina alterniflora

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    互花米草(Spartina alterniflora)是我国危害最严重的外来入侵植物之一,探索环保、经济、有效地防治互花米草的技术对保护我国海滩生态环境具有重要意义。本研究通过人工气候室(20~25℃)的盆栽实验,研究刈割与淹水对互花米草萌发和幼苗生长的影响。实验持续4个月,对互花米草地上部分进行了2次刈割,首次刈割是在互花米草生长季结束时,3个月后进行第二次刈割。首次刈割后持续淹水至实验结束,淹水处理设计0、5、10、20 cm四个淹水深度。首次刈割后各淹水处理互花米草根茎上迅速萌发克隆苗,种子的萌发比克隆苗晚约3个月。不同淹水深度对克隆苗的萌发和生长均有抑制作用,克隆苗株数、株高和地上生物量均随淹水深度增加而减少。第二次刈割后各淹水处理均没有再萌发克隆苗,但有少量种子实生苗,其中20 cm水深处理的实生苗数量最少。刈割加淹水可以很好地抑制互花米草的萌发和幼苗生长,据此建议互花米草防治方案为:在春季萌芽前,修筑堤坝,保持淹水20 cm,在营养生长期后期贴地刈割互花米草,继续淹水,第二年重复同样的刈割和淹水。为防止二次入侵,需要在邻近的互花米草分布区同时进行治理。&nbsp;</p

    Effects of mechanical and chemical control on invasive Spartina alterniflora in the Yellow River Delta, China

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    Spartina alterniflora is one of the most noxious invasive plants in China and many other regions. Exploring environmentally friendly, economic and effective techniques for controlling Spartina alterniflora is of great significance for the management of coastal wetlands. In the present study, different approaches, including mowing and waterlogging, mowing and tilling and herbicide application, were used to control Spartina alterniflora. The results suggest that the integrated approach of mowing and waterlogging could eradicate Spartina alterniflora, the herbicide haloxyfop-r-methyl could kill almost all the Spartina alterniflora, and the integrated approach of mowing and tilling at the end of the growing season was a perfect way to inhibit the germination of Spartina alterniflora in the following year. However, no matter which control approach is adopted, secondary invasion of Spartina alterniflora must be avoided. Otherwise, all the efforts will be wasted in a few years

    Control of invasive Spartina alterniflora: A review

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    互花米草在其原产地具有保滩护堤、促淤造陆等生态功能,但在被引入其他地区后,常给当地生态系统带来诸多负面影响,因此,互花米草常被视为入侵种,对互花米草的入侵性以及防控方面的研究成为一大热点.本研究从物理防治、化学防治、生物防治、生物替代防治、综合防治和防控策略6个方面综述了互花米草防治的最新研究进展,对各类措施的理论基础、技术方案、防治效果和环境影响等方面进行了分析,指出了现有防治技术的不足,并提出生态风险分区防控等建议</p

    Resource utilization of invasive Spartina alterniflora: A review

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    In China, Spartina alterniflora, an invasive alien plant species, covers an area of approximately 54 600 hectares. The total dry matter of the aboveground part of S. alterniflora is 7.5*10~5~1.15*10~6 tons per year. The control and utilization of S. alterniflora have received increasing attention. A combined utilization and control approach could produce simultaneous economic and ecological benefits. Studies of the utilization of S. alterniflora in China tended to focus on the direct utilization of straw, including its use as fuel, feed, and raw material. These methods of utilization were generally low-value. Possible high-value utilization includes the medicinal value of S. alterniflora and its salt-tolerant genes. In all the studies, the largest proportion (43%) of straw was utilized as fuel, whereas the smallest proportion (approximately 8%) was utilized for other purposes, such as fertilizer and for its salt-tolerant genes. Previous studies have focused on utilization technologies, but they have not looked at S. alterniflora collection technology and market promotion. In the future, attention should be paid to every link of the industry chain of S. alterniflora utilization, and cooperation between research institutions and enterprises is essential for the synchronous development of industry, education, and research

    Resource utilization of invasive Spartina alterniflora: A review

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    外来入侵种互花米草(Spartina alterniflora)在我国的分布面积约为5.46万hm~2,每年地上干物质总量为7.5×10~5~1.15×10~6 t,其防治与利用受到越来越多的关注,若能将二者结合起来同时进行,可望收获生态和经济双重收益。我国对互花米草利用的研究主要为对秸秆的直接利用,包括燃料化利用、饲料化利用、原料化利用,这些利用方式一般为低值化利用,另有研究涉及互花米草的药用价值和耐盐基因等高值化利用。在所有利用研究中,秸秆燃料化利用占比最大,为43%,秸秆肥料化利用和耐盐基因等其他利用形式的占比最小,合计约为8%。总体而言,过去对互花米草利用的研究集中于加工利用技术这一环节,缺少对互花米草收集技术和市场化推广的研究,未来应该重视互花米草利用产业链的每一个环节,加强研究机构与企业的合作,实现产学研同步配套发展

    光通信用10Gbit/s Transponder的设计

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    本文分析了在高速光模块设计中介质损耗和微带结构对信号的影响,并对PCB中信号串扰模型的参数进行了计算.解决了高速光模块设计的一些关键问题,设计出满足MSA的300-pin transponder,并对模块进行了一系列性能和指标测试.测试结果表明,该模块完全满足SDH/SONET(STM-64/OC-192)以及10G Ethemet应用要求

    采用不同集热器的太阳能有机朗肯-闪蒸循环性能分析

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    针对太阳能有机朗肯-闪蒸循环(SBFC),本文基于EES(engineering equation solver)软件建立数学模型,以R245fa为循环工质,在集热器出口热水温度介于353.15~373.15K范围内,对平板集热器(FPC)和真空管集热器(ETC)驱动的SBFC系统热力性能以及投资成本进行了对比分析。选用的性能指标参数包括净输出功、热效率、第二定律效率、不可逆损失以及比初始投资。结果表明,随着集热器出口热水温度的增大,SBFC系统的热力性能显著升高,且采用ETC的系统比FPC系统在热力性能上更具优势,该优势随着热水温度的升高而持续增大。研究同时表明,在SBFC的投资成本中,太阳能集热器投资占比最大,且采用ETC的系统比初始投资远大于采用FPC的系统;此外,集热器出口热水温度的升高有利于降低SBFC系统的比初始投资

    Effects of herbicides on invasive Spartina alterniflora in the Yellow River Delta

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    互花米草(Spartina alterniflora)作为我国危害最严重的外来入侵植物之一,严重威胁滨海湿地生态系统安全。筛选可高效灭除互花米草的除草剂,为互花米草防治提供技术支持。2017年7月在黄河三角洲潮间带对互花米草茎叶喷施不同除草剂,在施药当年和次年对互花米草生长状况和大型底栖动物密度进行跟踪调查。研究结果表明:1)高效氟吡甲禾灵对互花米草的灭除效果最好,既能杀死互花米草地上部分从而完全抑制有性繁殖,又可完全抑制次年的无性繁殖;2)氰氟草酯对互花米草的灭除效果也比较好,可以完全抑制互花米草的生长和结穗,但抑制根状茎无性繁殖能力的效果稍差,草甘膦可以完全抑制互花米草的有性繁殖,但无法抑制次年互花米草的无性繁殖;3)施用除草剂在短期内会毒害某些底栖动物,但在1年后底栖动物种群数量与对照处理无显著差异。除草剂对环境的影响程度与除草剂用量和施用时间息息相关,未来研究中,应在保证灭草效果的前提下,探索最佳用药时间和最低用量以最大限度地降低环境影响。</p
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