开展了相同加载速度条件下单轴压缩煤样最大剪切应变、最小主应变和最大主应变的变异系数随纵向应变和纵向应力的演变规律.利用基于粒子群优化算法及牛顿-拉菲逊迭代方法获得煤样表面测点的位移,利用中心差分方法获得应变.研究发现,在煤样应变局部化启动(单轴抗压强度的56%)瞬时,最大剪切应变和最大主应变的变异系数发生了突增(分别为0.16~0.32和0.12~0.53);在煤样应变局部化启动至应力峰之间,两种
Drought, as a recurring extreme climate event, affects the structure, function, and process of terrestrial ecosystems. Despite the increasing occurrence and intensity of the drought in the past decade
Extreme heat events have serious effects on human daily life. Accurately capturing the dynamic variance of extreme high-temperature distributions in a timely manner is the basis for analyzing the pote
Understanding the temporal variations of extreme floods that occur in response to climate change is essential to anticipate the trends in flood magnitude and frequency in the context of global warming
The adjustment of administrative divisions is one of the important factors guiding Chinas urbanization, which has profound economic and social effects for regional development. In this paper, we compr
There is an increasing concern for potentially hazardous metals pollution, which can threaten crops production and human health. In this study, the spatial distribution and environmental risks of eigh
High PM_(2.5) concentrations and frequent air pollution episodes during late autumn and winter in Jilin Province have attracted attention in recent years. To describe the spatial and temporal variatio
今年是《极地研究》创刊30周年,在此致以衷心的祝贺!30年前的1988年,《南极研究》正式创刊,国家南极考察委员会主任武衡院士发表了发刊词,随着我国极地考察领域的拓展,1997年更名为《极地研究》,2011年期刊改版扩容。30年来,期刊发文量逐年增加,期刊质量不断提升。《极地研究》作为国内唯一集中反映南北极多学科考察研究成果的综合性中文学术刊物,给我国的极地科学工作者