Results 41 to 50 of about 1,266 (124)

Automating the analysis of public saliency and attitudes toward biodiversity from digital media

open access: yesConservation Biology, EarlyView.
Abstract Measuring public attitudes toward wildlife provides crucial insights into human relationships with nature and helps monitor progress toward Global Biodiversity Framework targets. Yet, conducting such assessments at a global scale presents challenges.
Noah Giebink   +8 more
wiley   +1 more source

黑龙江省的蝮蛇资源及保护现状

open access: yes野生动物学报, 2006
通过2001~2005年对黑龙江省蝮蛇资源进行调查研究,确定黑龙江省的蝮蛇为乌苏里蝮(Gloydius ussuriensis)、岩栖蝮(G.saxatilis)和中介蝮(G.intermedius)三种,主要分布在大、小兴安岭及东部山地。其中乌苏里蝮为广布种,种群数量居多;岩栖蝮主要分布在黑龙江省南部,数量较多;中介蝮主要分布在黑龙江省北部,种群数量较少,且与岩栖蝮存在地理隔离。同时对黑龙江省蝮蛇的保护现状和影响种群增长的因素进行分析,提出种群管理和合理利用的意见。
刘鹏, 赵文阁, 董丙君, 刘志涛
doaj  

Survival strategy of Calanus sinicus in the northwest of the South China Sea [PDF]

open access: yes, 2015
中华哲水蚤(Calanussinicus)是我国近海生态系统的特征种之一,在我国浮游生物学和近海生态系统动力学研究中具有重要意义。本文基于2006~2007年在南海西北部进行的四个季节的航次调查,研究了中华哲水蚤的空间分布和季节变化,以广义可加模型为工具量化分析了影响中华哲水蚤丰度变化的重要环境因子,同时探讨了南海西北部中华哲水蚤的种群来源和生存策略问题。主要研究结果如下: (1)中华哲水蚤的丰度变化具有显著的季节差异。在北部湾调查区域,春季平均丰度为2.37±8.00ind/m3,占桡足类总丰度的6 ...
杨璐
core  

Geographic risks to functional groups of mammals and birds from habitat loss in Mexico

open access: yesConservation Biology, EarlyView.
Abstract There is a need to quantify the impact of habitat loss due to anthropogenic factors on different aspects of biodiversity, such as functional trait diversity represented by functional groups (FGs). We developed a metric to assess the weighted risk of loss of habitat for 33 FGs of mammals and 36 FGs of birds in Mexico based on potential ...
Fernando Mayani‐Parás   +4 more
wiley   +1 more source

太行山片麻岩区植被恢复过程中物种多样性与土壤水分效益分析

open access: yesShuitu Baochi Xuebao, 2007
植被恢复是退化生态系统重建的重要途径,植被恢复过程中物种多样性的变化反映了植被的恢复程度,通过群落调查,研究了太行山片麻岩区植被恢复过程中群落物种多样性特征及其与土壤含水量之间的关系,结果表明:物种多样性指数天然灌木群落〉人工乔木群落。乔木和灌木群落各指数大小为封禁20年〉封禁10年〉封禁5年。6种群落其土壤含水量均偏低,随着封禁时间的加长,含水量略为增加,但天然灌木群落平均含水量稍大于人工群落。不同封禁时间群落土壤含水贯与均匀度指数成正相关,多样性指数与含水量先呈正相关,在封禁20年时,呈负相关 ...
徐学华   +4 more
doaj  

An experimental approach to assess the combined effects of multiple stressors on a large vertebrate species

open access: yesConservation Biology, EarlyView.
Abstract The design of experiments to investigate the combined effects of multiple stressors requires exposing target organisms to multiple combinations of stressor doses. Concurrent manipulation of stressors is often infeasible with wildlife, but long‐lasting health effects allow individual health to be used as an integrator of prior stressor exposure.
Enrico Pirotta   +24 more
wiley   +1 more source

Effects of tributyltin on Glucose Homeostasis in male mice and the recovery feasibility [PDF]

open access: yes, 2016
三丁基锡(Tributyltin,TBT)是一种有机锡化合物,TBT暴露对糖尿病发生的影响报道很少。本研究以KM小鼠为对象,研究TBT长期暴露导致小鼠糖尿病发生以及停止暴露后患病小鼠的恢复。采用浓度分别为0.5、5和50μg/kg的TBT通过灌胃法对小鼠进行暴露,每3天灌胃1次,暴露持续45天后立刻恢复60天。结果显示: 1.TBT暴露45天后,小鼠体重增加,相对于对照组,50μg/kg组体重增长显著;TBT暴露小鼠的饥饿血糖水平与对照组相比有显著的升高;并出现葡萄糖不耐受。停止TBT暴露恢复60天后 ...
李炳水
core  

一种基于差分进化神经网络的模糊控制方法 [PDF]

open access: yes, 2018
在模糊控制的实际应用中,隶属函数的选取往往依靠专家经验设定。这使得模糊控制由于隶属函数设定复杂,加大了实际应用的难度,往往达不到较好的控制效果。本文从RBF神经网络的特点出发,使用差分进化算法分成两个部分来优化RBF神经网络的参数,使之可以自动设置模糊控制的隶属函数。再通过模糊控制实时调整的PID控制器的三个参数,并分别对二阶系统和倒立摆系统进行仿真模拟。简化了模糊控制的设置方法,提高了进化算法在优化神经网络参数过程中的计算效率,取得了较好的控制效果。福建省高校产学合作项目 ...
何俊杰, 刘畅, 肖可, 陈松岩
core   +1 more source

Profiling EFL Students’ Motivation and Anxiety in Collaborative Learning: Associations With Teachers’ Support, Self‐Regulated Learning, and Achievement

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Previous research has established the relationships between motivation, anxiety, teachers’ support, and self‐regulated learning (SRL) in English‐as‐a‐foreign‐language (EFL) learning. Most of the studies, however, have taken a variable‐centered approach in addressing the variable correlations, while learners’ characteristics and variable links ...
Yuhong Jiao, Barry Bai, Jing Li
wiley   +1 more source

Study on latitudinal gradient of species diversity in forest communities [PDF]

open access: yes, 2015
森林群落结构和物种多样性的空间分异规律一直是生态学研究的热点问题。近年来,关于森林群落结构的描述与物种多样性的测定方法等研究也都有所发展,但这些研究大多是对森林生态系统的定性描述,而且方法不一,数据之间也缺乏可比性。 群落的组成结构是群落的重要标志,研究群落结构是研究群落物种多样性意义的理论基础,所以从群落组成结构的角度来探讨生物群落的物种多样性具有重要的意义,为进一步深入研究生物多样性功能及确定功能群提供理论基础 ...
孙影
core  

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