Results 101 to 110 of about 17,401 (196)
小扭口藓(Barbula indica)芽胞发育特征的实验研究 [PDF]
, 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
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Assessing differences among elasmobranch nurseries to aid conservation based on a genomics framework
Conservation Biology, EarlyView.Abstract Elasmobranch nurseries often differ in environmental conditions, demographics, and use patterns. These differences affect the distribution of genetic variation among nurseries. However, conservation and management strategies often fail to account for such differences because they are difficult to characterize.
Dominic G. Swift +8 more
wiley +1 more source
Ecological Studies of Marine Virus and its Viral Lysate [PDF]
, 2015 病毒是海洋生态系统中数量最多、多样性最为丰富的一类生命形式，具有极为重要的生态地位。为了深入认识海洋浮游病毒及其裂解浮游细菌释放的裂解产物的生态效应，本论文首先研究了西太平洋典型寡营养海区的浮游病毒对浮游细菌的致死效应；接着研究病毒裂解产物如何在不同营养水平（寡营养和富营养）特征的海洋水体中影响浮游细菌的生长、群落组成等生态特性。此外，本论文以海洋生态系统中一类生态地位非常重要的浮游细菌-玫瑰杆菌（Roseobacter）为研究对象，对其裂解性病毒进行了分离纯化和鉴定 ...
纪建达
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Behavioral interventions to reduce demand for threatened freshwater turtles as pets
Conservation Biology, EarlyView.Abstract Growing demand for freshwater turtles as pets has fueled illegal trade and accelerated wild population declines, underscoring the need for theory‐based demand‐reduction interventions. We conducted a three‐part randomized controlled trial with active turtle keepers (n = 1800) in China to test conservation‐ and legality‐framed messages by ...
Wuji Zheng +9 more
wiley +1 more source
野生动物学报, 2009 通过问卷调查和样地调查方法,分析极端天气气候对宁夏野生动物种群安全产生的影响。极端天气气候对优势物种数量影响严重。雀形目种群安全主要受到沙尘暴、冰雹和暴雨的影响较大;迁徙鸟类种群安全主要受到沙尘暴、冰雹和暴雨的影响较大;啮齿类种群安全主要受到暴雨的影响较大;岩羊种群安全受到沙尘暴、冰雹、暴雨和降雪的影响。
刘晓红
doaj
Survey of viral diversity in the sediments of South China Sea [PDF]
, 2016 病毒是海洋生态系统中丰度最大，多样性最为丰富的微生物颗粒。海洋沉积物中的病毒丰度相比较海水中，要高1~2个数量级，并且其形态和基因型也更加多样。目前，人们对海洋沉积物中的病毒相关研究还比较少。为了增强对海洋沉积物中病毒的了解，本论文利用荧光显微镜法获得了珠江口沉积物以及南海北部和西部沉积物中病毒的丰度数据，并且通过病毒标记基因（g23&psbA）PCR扩增、克隆文库测序等分子技术获得了沉积物中T4类噬菌体和噬藻体类群的多样性信息。主要的研究结果： （1）荧光显微镜检测结果显示珠江口沉积物中病毒（4.49×
何茂求
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International Journal of Applied Linguistics, EarlyView.ABSTRACT The study investigated how writing motivation and self‐regulated read‐to‐write (SRL‐R2W) strategy use was related to writing performance and how the relationship between motivation and SRL‐R2W strategy use varied among different writing performance groups.
Huixuan Zhou +3 more
wiley +1 more source
野生动物学报, 2015 对中国白头鹤圈养种群的统计学和遗传学结果进行了相关分析,并对种群数量、年龄结构、性比情况、基因多样性、近交系数以及未来100 a种群的发展趋势进行了重点研究。结果表明:截止到2013年12月31日,中国圈养白头鹤种群共有存活个体76只,分别饲养于15家单位,其中建立者的数量为16只,潜在建立者的数量为41只。圈养白头鹤种群中育龄个体充足,但幼龄个体数量不足,种群年龄结构不是很合理。白头鹤种群保留了野生个体92.9%的基因多样性,平均近亲系数为0,是一个没有任何近亲繁殖的优质种群。通过分析发现 ...
何相宝 田秀华 李晓敏 周军英 尹惠媛
doaj
Sequencing and correlation analysis of miRNAome and transcriptome of Larimichthys crocea infected by Cryptocaryon irritans [PDF]
, 2016 大黄鱼（LarimichthyscroceaRichardson，1846）曾是我国的传统四大海洋渔业对象之一，也是我国目前最主要的海水网箱养殖经济鱼类之一，2015年养殖年产量超过14万吨。近年来由于发展模式的制约，养殖管理的缺失，加之养殖环境的严重污染，大黄鱼养殖过程中的各种病毒性疾病，细菌疾病和寄生虫疾病日趋严重，其中以刺激隐核虫（Cryptocaryonirritans）病的危害最为严重。其所感染大黄鱼并导致继发性的细菌感染，造成养殖大黄鱼大面积死亡，对该养殖产业损失极大 ...
乔莹
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How Do I Measure up? Social Influence and L2 Motivation in the Algorithmic Age
International Journal of Applied Linguistics, EarlyView.ABSTRACT Comparative thinking is a fundamental human drive and a hallmark of contemporary life. For social action, such as the learning and use of additional languages, a target for appraisal (an L2 attribute) is evaluated in relation to a comparison standard (an appraiser's standpoint).
Alastair Henry, Meng Liu
wiley +1 more source