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91.
通过对中山公园实地调研,对园林植物种类、生活型、生态型和观赏特性进行了分析与总结,结果表明:中山公园植物总共162种,隶属于69科129属;具有亚热带地域风味以及岭南风情,植物群落布设自然合理,既符合适地适树的科学原则,也具有外来树种与乡土树种相结合等特点;存在有乡土树种种类少,人类活动与行为对植物景观造成的影响较大,公园的养护管理不到位以及特色植物菊花的配置形式简单等问题;因此在探讨植物种类选取的科学性基础上,从科学性、艺术性、生态性等角度出发,提供了一些优化建议。 相似文献
92.
黄晓剑 《中南林业科技大学学报(自然科学版)》1991,(2)
机构的第2类可动性。是机构分析与综合所要探讨的基本问题之一。本文对一般形式的空间RRRSR五杆机构的可动性进行分析。通过拆开运动副,分析运动轨迹,根据其雅可比矩阵奇异获得各位形分支的边界后,采用拓朴变换原理,讨论得出该机构的装配条件和连架杆的运动情况。为空间多杆机构的第2类可动性分析,提供了一条方便、实用的途径。 相似文献
93.
陈幼南 《林业机械与木工设备》2001,29(7):12-14
介绍了装板机械与液压系统的组成,工作原理和设计特点,装板机为引进德国中密板生产线上的关键设备,对该设备的剖析于同类设备的国产化有着重要意义。 相似文献
94.
Takeshi Katayama Jyoji Tsutsui Kazuo Tsueda Takao Miki Yasuhiro Yamada Murao Sogo 《Journal of Wood Science》2000,46(6):458-465
When (±)--oxo-guaiacylglycerol--(vanillic acid) ether (1) is degraded byFusarium solani M-13-1, the-ketone is initially reduced to giveerythro andthreo guaiacylglycerol--(vanillic acid) ethers (2), arylglycerol--aryl ethers, both of which are enantiomerically pure. The absolute configuration in each2 was determined by Mosher's method; the products were converted to,-di-(R)--methoxy--trifluoromethylphenylacetates (MTPA esters) (3) oferythro (-)- andthreo (+)-veratrylglycerol--(methyl vanillate) ethers (3), whose1H nuclear magnetic resonance (NMR) spectra were examined and compared with those of four di-(R)-MTPA ester (3) diastereomers from chemically synthesizederythro (±)-3 andthreo (±)-3. To assign the- and-MTPA-OCH3 peaks, the1H NMR scans of several compounds that have substructures of 3 and their 3,4,5-trimethoxyphenyl analogues were examined. When a racemic alcohol reacts with (R)-MTPA to give a pair of (R)-MTPA ester diastereomers, the value was defined as the absolute value of the difference in the1H chemical shifts of the peak between the diastereomers. It was found that the values of-MTPA-OCH3 were larger than those of-MTPA-OCH3 owing to a shielding effect of the veratryl ring located on the-MTPA-OCH3, and that the-MTPA-OCH3 peaks in the 3,4,5-trimethoxyphenyl compounds shifted downfield relative to those in the veratryl compounds. On the basis of the1h NMR data of (R)-MTPA esters, the absolute configuration of the four chemically prepared diastereomers (3) were determined. The catabolicerythro
3 [fromerythro (-)-3] andthreo
3 [fromthreo (+)-3] were identical to (R, S, R)-erythro
3 and (R, S, S)- threo
3, respectively. An hydrogen species in the fungal reduction would attack the-ketone fromre-face of both (R)-1 and (S)-1, givingerythro (S, R)-2 andthreo (S, S)-2, respectively.Part of this paper was presented at the 33rd Lignin Symposium, Tsukuba, November 1988 相似文献
95.
文章在分析宁夏生态经济型林业发展现状的基础上,以生态学、恢复生态学和生态经济学为理论基础,围绕“生态”“经济”两条主线,以林业资源保育和增加植被盖度为切入点,由北向南将宁夏构建为3个林业生态功能区,即宁夏干旱带贺兰山及引黄灌溉绿洲生态网络体系建设区、宁夏中部干旱风沙带灌草配置区、宁夏南部半干旱带水土保持和水源涵养林区,实行多林种、树种,多序列的资源优化配置,以期形成产出效益的多样性和受益的社会性。 相似文献
96.
从分析我国城市园林植物配置的现状出发,阐述了园林植物生态配置的内涵、特点和原则,提出了园林植物生态配置应以构建人工顶级植物群落为园林设计"立意在先"的基础、以地带性植物作为绿化植物材料选择的依据、以模仿植物的自然组合作为园林植物的主要配置形式等三个方面来合理地配置植物,使城市园林绿化达到最佳的综合效果。 相似文献
97.
98.
介绍了渭南移动分公司生产调度楼的方案构思与立意、总体布局、建筑功能设计、建筑智能化与节能。 相似文献
99.
100.
Shiang‐Lin Huang Haiping Wu Xianyan Wang Chongwei Peng Chun‐Chieh Wang 《水产资源保护:海洋与淡水生态系统》2020,30(9):1775-1782
- Protecting critical habitats of the Indo‐Pacific humpback dolphin, Sousa chinensis, is a hot topic of discussion for marine biodiversity conservation in China and many Southeast Asian countries. In practice, sound habitat protection action (HPA) planning often suffers from information gaps in macroscopic habitat configurations and changes in the habitat conditions of humpback dolphins.
- Recent publications in the journal Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) have served to advance humpback dolphin conservation in Chinese waters by resolving such habitat configurations and indicating significant changes in distribution patterns and habitat characteristics under intense coastal anthropogenic activity.
- We highlight an integrative research framework to investigate habitat configuration and long‐term habitat changes when planning a holistic HPA programme for humpback dolphins. When constructing habitat configuration baselines, field surveys should be designed and conducted in a systematic manner to ensure survey efforts cover diverse environments equally, in either a spatially stratified or gridded pattern, to minimize potential spatial sampling biases. Long‐term habitat changes can be revealed by comparing satellite images from different decades. Changes in habitat preferences and habitat characteristics can be explored through questionnaire surveys on local ecological knowledge, associating historical occurrences with coastline features and projecting historical habitat configuration by species distribution modelling exercises.
- A lack of good communication and sharing of information between research and management sectors can still be an obstacle to the implementation of sound conservation practices, however, even though there is robust scientific evidence to fill knowledge gaps in distribution and habitat baselines. We have addressed the need to establish a mechanism to improve and streamline information sharing between research teams, management sectors, and stakeholder groups.