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91.
The study explored the effects of intensive urbanization on urban plant diversity and landscape pattern. An inventory of plant species in managed green spaces in the nine urban districts of Guangzhou (south China) with varied development history was conducted. The relationships among species richness, diversity and urban development were analysed by community ecology attributes, cluster analysis, growth-form differentiation and district fidelity indices, and statistical tests. The 1055 vascular species were dominated by a small number of common evergreen species, accompanied by many rare species. By species richness, tree was the dominant growth form, followed by herb and shrub. Species richness and diversity were slightly below urban-fringe secondary forests. Old and young districts offered disparate conditions for species enrichment to establish urban landscape patterns with divergent floristic and growth-form assemblages. Urban species profile and vegetation landscapes were mainly influenced by planning and management of the urban landscape and changing landscape fashion. 相似文献
92.
M. George 《Construction Management & Economics》2019,37(8):419-432
There is a widely accepted assumption in the construction literature that the industry is highly masculinised. However, there has been a surprising lack of empirical evidence around workers’ own attitudes towards masculinity in the sector. Addressing this lack of research, a survey to measure construction site operatives’ attitudes towards traditional masculinity ideology was undertaken in Australia using the Male Role Norms Inventory Scale-Short Form (MRNI-SF). It is found that the focus of attitudes towards masculinity in the construction industry may be shifting to reflect trends in the wider population and may be more inclusive and less hegemonic than has been previously argued. It is also found that the focus of masculinity in the construction industry is closely related to the physical and high-risk nature of work and that sexuality and humour may also be an important source of masculine identity. These results are important since they contribute a more nuanced understanding of the dimensions and exact nature of attitudes towards masculinity in the construction industry. It is concluded that future research into the impact of masculinity in areas such as gender diversity, safety and mental health would benefit from a more inclusive theoretical lens which recognises the dynamic nature of masculinity and which highlights the institutional legacies of past hegemonies that have to be challenged to move the industry forward. 相似文献
93.
针对超双疏涂层在建筑室内、外功能性家装领域的应用问题,采用溶胶-凝胶法,以正硅酸乙酯(TEOS)和甲基三甲氧基硅烷(MTMS)为共前驱体,结合1H,1H,2H,2H-全氟辛基三甲氧基硅烷(PFTMS)改性制备了PFTMS-SiO2有机-无机杂化超双疏涂覆液。当改性剂与正硅酸乙酯摩尔比达到0.3时,该涂覆液在玻璃、瓷砖、石材、水泥板表面形成的涂层均呈现超双疏特性,最高水接触角157.4°,正十六烷接触角142.6°,涂层附着力达到1级,耐洗刷试验1600次后仍保持良好超双疏性能。XPS结果表明,经过改性处理后的SiO2链段上含氟基团相对含量达到了69.53%,在玻璃表面形成的超双疏涂层含氟基团相对含量为33.75%,涂层表面的平均粗糙度达到937 nm,说明了含氟基团的成功引入及表面凹凸不平的微观形貌共同构成了涂层表面的超疏性能。 相似文献
94.
Mary W. Stoertz Heather Bourne Christa Knotts Matthew M. White 《Mine Water and the Environment》2002,21(2):60-72
Isolated headwater streams in mined watersheds may have good water quality and fish habitat, yet be disconnected from immigration
sources by stream segments impaired by acid mine drainage (AMD). Studies of fish and macroinvertebrate communities, habitat,
and a number of hydrochemical parameters in Monday Creek, Ohio, show that AMD eliminates fish communities and severely limits
macroinvertebrate communities in directly affected tributaries. Isolated headwaters in the heavily mined Monday Creek watershed
have relatively good water quality and habitat, but poor fish communities. Comparison of isolated Monday Creek headwaters
with non-isolated reaches in unmined watersheds indicates that differences in fish communities are attributable to isolation.
Fish communities in isolated headwaters have lower Indices of Biotic Integrity (IBI) than comparable non-isolated communities,
reduced species numbers, and lower numbers of individuals, despite suitable habitat as measured by the Qualitative Habitat
Evaluation Index (QHEI). Comparison of macroinvertebrate communities shows higher Invertebrate Community Indices (ICI), and
no apparent species loss, which can be attributed to the obligate flight stage in the life cycle of many macroinvertebrates,
which enables them to overcome aquatic barriers. The implication of this research is that there is an opportunity for recovery
of depleted fish communities in large AMD-isolated areas with good water quality, suitable habitat, and intact macroinvertebrate
communities, by downstream treatment or source control of AMD to create aquatic corridors for fish immigration. 相似文献
95.
96.
【目的】研究旨在通过构建栖息地适宜性评价模型,对山东省烟台市东岛咀滨海绿地的鸟类多样性和栖息地本底进行调查和评估,并为开展城市鸟类栖息地营建及海岸带生态景观规划设计提供参考。【方法】研究以烟台市东岛咀滨海绿地为研究区域,通过实地调查对其鸟类多样性特征进行分析,同时运用相关性分析和冗余分析探究表征鸟类栖息地食源条件、隐蔽条件和人为干扰强度特征的19个群落环境因子对鸟类多样性的影响,并在此基础上结合层次分析法构建东岛咀滨海绿地鸟类栖息地适宜性评价模型,对陆地区域的鸟类栖息地质量进行定量评价。【结果】分布连续的大面积林地是研究区域内鸟类多样性最高的区域;在不同海岸线距离梯度下,乔木盖度、乔木丰富度指数、灌木盖度、草本盖度等8个环境因子与至少1项鸟类多样性指标显著相关,其中,乔木层的结构特征对滨海鸟类多样的积极影响更突出;东岛咀滨海绿地的鸟类栖息地适宜性水平呈现近海区域低、远海区域高的特征。【结论】以阔叶乔木覆盖为主要特征的林地对滨海绿地鸟类多样性有突出的支持功能,是鸟类栖息地营建的重要生境。本研究构建的栖息地适宜性评价模型能够有效地模拟研究区域鸟类栖息地质量的现状分布特征,对烟台东岛咀滨海绿... 相似文献
97.
主要介绍了OFDM-CDM系统以及它在高速传输下与通常的OFDM系统的比较.OFDM-CDM系统将信号扩展到不同的子载波上,可以达到很好的频率分集的效果.该文详细介绍了OFDM-CDM系统以及对其有效的检测技术,并进行仿真.通过性能的对比,可以看出OFDM-CDM系统比一般的OFDM系统有很大的优势. 相似文献
98.
99.
Ngoc Tuan Nguyen Wei-Hsin Sun Tzu-Hsuan Chen Po-Chun Tsai Chih-Chen Chen Shir-Ly Huang 《International journal of molecular sciences》2022,23(7)
Rheumatoid arthritis (RA), an autoimmune disease, is characterized by chronic joint inflammation and pain. We previously found that the deletion of T-cell death-associated gene 8 (TDAG8) significantly reduces disease severity and pain in RA mice. Whether it is by modulating gut microbiota remains unclear. In this study, 64 intestinal samples of feces, cecal content, and cecal mucus from the complete Freund’s adjuvant-induced arthritis mouse models were compared. The α- and β-diversity indices of the microbiome were significantly lower in RA mice. Cecal mucus showed a higher ratio of Firmicutes to Bacteroidetes in RA than healthy mice, suggesting the ratio could serve as an RA indicator. Four core genera, Eubacterium_Ventriosum, Alloprevotella, Rikenella, and Treponema, were reduced in content in both feces and mucus RA samples, and could serve microbial markers representing RA progression. TDAG8 deficiency decreased the abundance of proinflammation-related Eubacterium_Xylanophilum, Clostridia, Ruminococcus, Paraprevotella, and Rikenellaceae, which reduced local mucosal inflammation to relieve RA disease severity and pain. The pharmacological block of the TDAG8 function by a salicylanilide derivative partly restored the RA microbiome to a healthy composition. These findings provide a further understanding of specific bacteria interactions with host gut mucus in the RA model. The modulation by TDAG8 on particular bacteria can facilitate microbiota-based therapy. 相似文献
100.
该研究采用Illumina MiSeq高通量测序技术对襄阳市石花酒大曲中微生物多样性进行分析。结果表明,4个样品中优势细菌门(>0.1%)为变形杆菌门(Proteobacteria)、厚壁菌门(Firmicutes)和放线菌门(Actinobacteria),且均为核心菌门;优势细菌属(>1%)为假单胞菌属(Pseudomonas)、芽孢杆菌属(Bacillus)、乳杆菌属(Lactobacillus)、链霉菌属(Streptomyces)、魏斯氏菌属(Weissella)、明串珠菌属(Leuconostoc)和Kroppenstedtia。优势真菌门(>0.1%)为子囊菌门(Ascomycota)、担子菌门(Basidiomycota)和Mucoromycota,其中子囊菌门为核心菌门;优势真菌属(>1%)为复膜孢酵母属(Saccharomycopsis)、红曲菌属(Monascus)、热子囊菌属(Thermoascus)、青霉菌属(Penicillium)、曲霉属(Aspergillus)和Leiothecium。样品中假单胞菌属和曲霉属呈现显著正相关(P<0.05)。综上,4个石花酒大曲样品中共有大量的核心菌群,且样品中细菌与真菌有一定的相关性。 相似文献