Results 11 to 20 of about 11,190 (177)

中华按蚊自然种群动力学——Ⅲ.净增殖率及其他有关参数 [PDF]

open access: yesZhongshan Daxue xuebao. Yixue kexue ban, 1985
近年来我国已开始进行中华按蚊实验室种群动力学的观察,加深了了解种群数量变动的原因,对传播疟疾的动力学及媒介防制均有重要的参考价值。但迄今未见有关中华按蚊自然种群动力学的报道。本文是在观察中华按蚊幼虫期在自然界孳生地的存活率的基础上,进一步研究中华按蚊自然种群的净增殖率及其他有关参数,分析构成数学模型的数据对各项参数的影响。
何桂铭
doaj   +2 more sources

Population Structure Characteristics and Survival Status of Natural Platycladus Orientalis in Loess Hilly Region [PDF]

open access: yes, 2023
[Objective] Population structure characteristics and survival status of natural Platycladus orientalis in the loess hilly region were determined in order to provide a scientific basis for high-quality and sustainable development of forest grassland in ...
Gu Zhonghou   +8 more
core   +1 more source

A Fast Optimization Algorithm for Fin Structure of Phase Change Thermal Storage [PDF]

open access: yes, 2022
The phase change thermal storage technology has broad application prospects in the field of solar thermal power generation and the fins can effectively increase the charge and release rate of the phase change heat storage.
CAI Xiao   +3 more
core   +1 more source

Improved PESA algorithm based on comentropy [PDF]

open access: yes, 2013
Aiming at the issue that the computational effort the complexity and the running time of PESA algorithm are increasing rapidly with the growth of the solutions set number, a comentropy-based PESA algorithm (C-PESA) by merg-ing the entropy value metric ...
Kun WANG   +4 more
core   +1 more source

Life Stage‐Specific Genetic Diversity and Landscape Characteristics Collectively Influence Genetic Recovery in Pometia pinnata Population 生活史阶段特异的遗传多样性与景观特征对番龙眼种群遗传恢复的协同影响

open access: yesIntegrative Conservation, EarlyView.
Pometia pinnata demonstrated life‐stage‐specific genetic responses to landscape features, with asymmetric gene flow patterns and population recovery following historical bottlenecks, revealing complex topographic and demographic influences on forest genetic structure.
Madhuparna Chatterjee   +5 more
wiley   +1 more source

银鲫遗传型雄性和温度依赖型雄性的比较研究 [PDF]

open access: yes, 2018
在变温动物中,不同的性别决定机制可以在同一物种中共存并且发生相互转变,但由不同性别决定机制造成的雄性之间的差异及其内在机制还不清楚。在本研究中,我们利用同时具有遗传型性别决定和温度依赖型性别决定的雌核生殖银鲫(Carassius gibelio)来阐述这个问题。 通过本文的研究发现,银鲫遗传型雄性和温度依赖型雄性具有相似的雄性形态、精巢组织结构、精子结构和精子活力。然而,当雌性个体与遗传型雄性受精时,在受精卵中可以观察到精核发生解凝并与雌原核融合。与此相反的是,当雌性个体与温度依赖型雄性受精时 ...
朱要军
core  

Risk of Secondary Extinction in the Asian Songbird Trade, as Exemplified by the Selling of Crested Jayshrikes as Master Birds

open access: yesIntegrative Conservation, EarlyView.
The Asian Songbird Crises negatively affects so‐called master birds, species that are used to increase the song complexity of competitive songbirds. We assessed the trade in a master bird, the crested jayshrike, in Indonesia before and after its legal protection.
Vincent Nijman   +11 more
wiley   +1 more source

小扭口藓(Barbula indica)芽胞发育特征的实验研究 [PDF]

open access: yes, 2005
在光照培养箱中人工对照培养小扭口藓(Barbulaindica(Hook. )Spreng)的芽胞,显微镜下观察并记录其发育成配子体的全过程。结果表明:小扭口藓芽胞在3 ~4d即可萌发; 10d左右开始分化出绿丝体、轴丝体及假根; 18d,轴丝体上的侧枝顶端细胞以分生缢割的方式产生单细胞或多细胞芽胞; 40d,轴丝体上开始出现配子体原始细胞;之后,配子体原始细胞发育成桑椹状的幼小配子体。还对芽胞形态发育、生理生态及配子体发生过程的特点进行了分析和讨论。,CN 23-1480/
赵建成,黄士良,李敏,张元明,王晓蕊,范庆书
core  

Are Galliformes of the High Himalayas Well Protected? Identifying Conservation Priority Areas Using an Assemblage‐Level Approach 高喜马拉雅地区的鸡形目鸟类是否得到了有效保护?利用群落水平方法确定优先保护区域

open access: yesIntegrative Conservation, EarlyView.
This study investigates distribution patterns of Galliforms in the Indian Himalayas, focusing on factors influencing their occurrence, regions of high diversity and endemism, and their overlap with protected areas. Our study highlights the need for assemblage‐level conservation strategies in high Himalaya which primarily relies on snow leopard‐focused ...
Manvi Sharma   +5 more
wiley   +1 more source

Community and population research of Tsuga longibracteata [PDF]

open access: yes, 2016
长苞铁杉(TsugalongibracteataCheng),是属于松科(Pinaceae),铁杉属(Tsuga)的第四冰期孑遗植物;主要分布在我国22°49'-28°33'N,107°12'-118°14'E之间;由于自身更新速度缓慢以及长期的砍伐利用,其地理分布相对狭小且呈零星分布,分布区和居群规模在逐渐缩小和下降,面临着灭绝的危险;本文针对分布在福建省内各县市的长苞铁杉群落进行了基本区系特征、物种多样性、种群生命过程、分布格局和生态位等方面的生态学研究,结论主要如下: 1、各样地长苞铁杉群落在科 ...
夏玉叶
core  

Home - About - Disclaimer - Privacy