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11.
近红外光谱法快速鉴定干海参产地   总被引:3,自引:3,他引:3       下载免费PDF全文
该文采用近红外漫反射光谱法,对来自4个不同产地的96个干刺参样品,进行了产地鉴别分析。研究表明:在5 000~4 000 cm-1 波段,干海参样品具有丰富的光谱结构,且反映出了由于海参生长环境不同带来的差异性;对该波段的一次微分光谱数据进行主成分聚类(PCCA)计算,可成功实现对其产地的鉴定分析。该研究为动物性海洋食品的产地快速鉴别分析提供了新方法。  相似文献   
12.
Numerous plants ofSilene nicaeensis having symptoms resembling those associated with the presence of phytoplasmas were observed in an extensive coastal area in the south of Italy. Microscopic observation showed histological abnormalities in the organization of tissues in symptomatic plants, and molecular tests, including PCR/RFLP analyses and nucleic acid sequencing, revealed the presence of phytoplasmas belonging to the aster yellows group (‘Candidatus phytoplasma asteris’). This is the first report of phytoplasma infection inS. nicaeensis, a wild species that colonizes the Calabrian coast. http://www.phytoparasitica.org posting June 12, 2008  相似文献   
13.
为探索小灵猫人工驯养繁殖技术,对小灵猫生态行为进行观察研究,结果表明,小灵猫的某些野性可通过人为引导加以改进,向有利于人工养殖的方面发展,并成功地引导其定点排粪及投食后即时取食。  相似文献   
14.
    
Water shortage and global water demand in arid and semi‐arid countries are continuously increasing, and therefore the agricultural sector is under critical pressure. Sustainable water management is a crucial issue and needs detailed investigation. Lysimeter measurement and nuclear techniques have been used to improve water management, saving water by reducing loss components which are not used by the plants and thus enhance water productivity (WP). Two experimental sites were selected at Nashabieh and Serghaya in the Damascus Basin (Syria). Monitoring of soil water content, evaporation and deep percolation measurements were carried out. The results showed that the measured deep percolation in a maize field (Nashabieh) formed 20% of the applied drip irrigation. On average, volumetric water content increased with depth from 30 to 37% in the apple orchard field under drip irrigation (Serghaya). Water component distribution reveals that 10–20% of water can be saved and used to enhance WP. The computed WP of maize crop was 1.4 kg m−3. Thus the surface drip irrigation method increases WP significantly. Consequently, the application of this irrigation method at the farm scale is highly recommended. Finally, these results may help to develop better agricultural water management strategies, increase agriculture productivity, and consequently improve WP. © 2019 John Wiley & Sons, Ltd.  相似文献   
15.
张雄  张庆红 《北方园艺》2019,(9):176-183
构建了包含思想观念、普通话水平等内容的农户多维贫困指标体系,基于2017年微观调查数据,利用A-F方法测度了南疆三地州连片特困地区农户多维贫困状况,并进一步从家庭特征、村庄特征和县域特征方面系统地探究农户多维贫困的影响因素。结果表明:该地区农户贫困多元化特征显著,多维贫困发生率较高,从维度分解看,思想观念、普通话水平和收入对多维贫困的贡献最大。对农户家庭劳动力开展职业技能培训、改善农户生产生活自然条件、村文化基础设施建设、提高教育基础设施可达性、通村公路建设和增加县公共财政投入可以显著降低农户陷入多维贫困的可能性。  相似文献   
16.
本文对林区建筑物普遍存在的质量通病进行了分析。对其产生的原因及防治措施提出了自己的观点。该内容对林区建筑设计人员有一定的借鉴。  相似文献   
17.
送电线路的路径选择是线路设计中的重要环节,直接影响工程总造价及运行可靠性。该文针对送电线路选择路径的特点,建立全局最优路径的搜索模型,形成简单的连通图,并对基本蚁群算法的选择策略及信息素更新进行改进,同时考虑了地质状况、水文情况及林带征地等对线路路径选择的影响,最后利用改进的算法直接在模型上进行全局最优路径搜索。仿真结果表明,此方法可以准确地搜索到送电线路的全局最优路径。  相似文献   
18.
对照“金牌住区”七大特色目标,对哈尔滨市近年开发的规模住区人居环境进行深入调研,分析总结现状存在的共性特征和发展的优劣势,指出今后规模住区人居环境改进方向。  相似文献   
19.
Recognition and analysis of dynamic information about population images during wheat growth periods can be taken for the base of quantitative diagnosis for wheat growth. A recognition system based on self-learning BP neural network for feature data of wheat population images, such as total green areas and leaves areas was designed in this paper. In addition, some techniques to create favorable conditions for image recognition was discussed, which were as follows: (1) The method of collecting images by a digital camera and assistant equipment under natural conditions in fields. (2) An algorithm of pixei labeling was used to segment image and extract feature. (3)A high pass filter based on Laplacian was used to strengthen image information. The results showed that the ANN system was availability for image recognition of wheat population feature.  相似文献   
20.
Currently, rural residential space can't continue to meet the growing demand for tourism receptions because of the development of rural tourism, resulting in the evolution and reconstruction of residential space in rural areas. In the past decade, rural tourism has become the main driving force for industrial transformation and economic growth in rural areas of China. Taking three tourism-oriented villages in Jizhou District, Tianjin, namely Xiaochuanfangyu Village, Dongshuichang Village and Maojiayu Village, as the objects of the research, this paper analyzed the influence of rural tourism on the evolution of rural residential space from the perspectives of the spatial pattern and architectural style at the microscopic scale.  相似文献   
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