Results 21 to 30 of about 107,409 (290)

Taxonomic study on Orychophragmus Bunge (Brassicaceae),a genus endemic to China(中国特有植物诸葛菜属(十字花科)的分类研究)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2017
诸葛菜属Orychophragmus Bunge为中国特有植物,至今为止在分类学上仍存在较大分歧.在文献考证、野外采集和标本查阅的基础上,对诸葛菜O. violaceus、铺散诸葛莱O. diffusus(O. violaceus var. homaeophyllus)、湖北诸葛莱O. hupehensis、太白诸葛菜O. taibaiensis的13个形态性状进行了观测.基于对6个居群58个个体的形态性状的观测数据,进行了主成分分析(PCA).结果表明:(1)PCA散点图显示所分析的所有个体可分成3类,
CHENZhenhui(陈珍慧)   +4 more
doaj   +1 more source

Combating infections under siege: Healthcare challenges amidst the military assault in Gaza

open access: yesWorld Medical &Health Policy, Volume 17, Issue 1, Page 188-213, March 2025.
Abstract The ongoing Israeli military assault on Gaza has caused a devastating collapse of healthcare infrastructure, resulting in an unprecedented surge in infectious diseases. The destruction of sanitation systems, restrictions on medical supplies, and displacement of civilians have created an environment conducive to the rapid spread of waterborne ...
Bilal Irfan   +24 more
wiley   +1 more source

香溪河小水电的梯级开发对浮游藻类的影响 [PDF]

open access: yes, 2007
以香溪河干流上5个连续的小水电站为对象,于2005年10月20—22日分别对其浮游藻类和主要理化指标进行研究.结果表明:硅藻占绝对优势(95.54%),其中,线性曲壳藻(Achnanthes linearis)、披针曲壳藻椭圆变种(A.lanceolatavar.elliptica)、扁圆卵形藻(Cocconeisplacentula)为绝对优势种,其平均相对丰富度分别为23.96%、18.62%和12.48%;所有样点的平均藻类密度为6.29×105ind.L-1,最高为1 ...
傅小城   +5 more
core  

Community feature and species diversity of Acacia mearnsii communities in Wenzhou(外来种黑荆树的群落特征及其对物种多样性的影响)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2010
以温州地区黑荆树(Acacia mearnsii)入侵群落为对象,采用样方法对10个样地进行了群落学调查,研究其群落的种类组成、区系特点、数量特征和物种多样性,探讨了黑荆树对群落物种多样性的影响.结果表明:①群落中共出现了225种维管束植物,分属于77科162属;②在种子植物属的分布区类型上,属于热带类型的有74属,占总属数的51.10%;温带类型50属,占总属数的34.48%;③群落可分为3种类型,其成层现象不明显,上木层中以黑荆树的优势度最大;下木层的物种丰富,各样地黑荆树的重要值有较大差异 ...
KEQian-qian(柯倩倩)   +5 more
doaj   +1 more source

Implementation of clinical breast examination screening programme as part of primary care in Vietnam: An analysis of contextual factors

open access: yesWorld Medical &Health Policy, Volume 17, Issue 1, Page 90-107, March 2025.
Abstract Clinical breast examination (CBE) screening for breast cancer in Vietnam was proved to be cost‐effective and acceptable to women. However, the outcomes of the implementation of such proposed programme are unknown. To inform the design and implementation planning of the proposed screening programme, this study investigated and analysed the ...
Tran Thu Ngan   +3 more
wiley   +1 more source

Four new plant records of Zhejiang discovered in Wenzhou(发现于温州的4种浙江植物分布新纪录)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2014
报道了近来发现的4个浙江分布新记录种:茄科的水茄Solanum torvum Swartz和多裂水茄Solanum chrysotrichum Schlechtendal; 爵床科的早田氏 爵床Justifies hayatae Yamamoto;菊科的银胶菊Parthenium hysterophorus Linnaeus.
LAIMengmeng(赖蒙蒙)   +4 more
doaj   +1 more source

Exploring Challenges and Opportunities in International Healthcare Partnerships: A Thematic Analysis

open access: yesWorld Medical &Health Policy, EarlyView.
ABSTRACT In global health collaborations, countries of all development levels may seek international assistance, emphasizing trust and conflict resolution. However, existing frameworks lack sustainability metrics, governance, and evaluation criteria.
Salma Arabi   +2 more
wiley   +1 more source

Research on Optimization of Fe Clusters Structure Based on Structural Clustering Niche Differential Evolution Algorithm [PDF]

open access: yes, 2016
团簇被称之为“物质第五态”。它是材料科学的新起点,在许多领域都有着广泛的应用。团簇的稳态结构对其独特的物理和化学等性质起到了至关重要的作用,因而受到许多学者的广泛关注。由于团簇的大小在几埃到几百埃之间,尺寸非常小,用实验设备很难合成和直接观测。因此用理论研究的方法来探究团簇的稳态结构显得十分重要。但是寻找团簇的稳态结构十分困难,除了基态结构之外,还存在成千上万的亚稳态结构。目前团簇优化问题已被学者证明为NP难问题,因此用传统的优化方法难以获得最优解,于是使得基于进化算法的全局优化方法得到了广泛应用 ...
郑骥文
core  

生境变化的种群效应——一种定量评价方法

open access: yes野生动物学报, 1991
野生动物的生境可能会在时间和空间上发生变化。在某一地区,各种生境所占比例的变化,可能引起该地区野生动物对整个生境适宜性的改变。因此,需要一个预测野生动物对生境变化所产生反应的生境关系模型(Verner et al, 1986)。本文根据野生动物短期的生境利用和野生动物管理中收集到的有关资料,提出了一种预测生境变化对野生动物影响的方法。生态学上关于生境选择理论是以种群密度大小表示生境质量好坏为前提的。故根据生境利用以及有关资料,便能直接地预测生境变化的结果。一、理论基础 ...
Robert Fagen, 张明海, 陈丽娟
doaj  

Comparison of photosynthetic characteristics and chlorophyll fluorescence parameters of Juglans cathayensis var. formosana in different habitats(不同生境华东野核桃光合生理特性及叶绿素荧光参数比较)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2013
采用LI-6400便携式光合作用系统,于2011年7月下旬的晴朗天气条件下,对浙江省天台山林窗、林缘、林下生境华东野核桃(Juglans cathayensis var. formosana)的光合生理特性及叶绿素荧光参数进行测定,并比较林窗生境中华东野核桃与其伴生植物山胡椒(Lindera glauca )、玉兰(Magnolia denudata)、云锦杜鹃(Rhododendron fortunei)光合日进程的差异.结果表明:夏季,林窗生境的华东野核桃及主要伴生植物叶片的净光合速率(Pn ...
LIYue-ling(李月灵)   +3 more
doaj   +1 more source

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