Research on Creep Deformation and Control Mechanism of Weak Surrounding Rock in Super Large Section Tunnel

Geotechnical and Geological Engineering - In order to solve the difficulties of creep deformation of surrounding rock in super large section tunnel, taking Letuan tunnel of Binlai expressway, a...     

四川盆地东部再生稻高温伏旱区腋芽萌发期气象适宜度

以四川盆地东部再生稻高温伏旱区为研究区,基于气象条件对腋芽萌发期再生稻生长发育的影响机理,采用结构方程模型探明了腋芽萌发的影响因素、影响路径及影响强度。进一步结合隶属函数和层次分析法,构建了再生稻腋芽萌发气象适宜度模型,并分析了1981—2021年研究区腋芽萌发期气象影响因素及气象适宜度的变化特征。结果表明：气温、空气湿度、降水是四川盆地东部再生稻高温伏旱区腋芽萌发的关键影响因素,基于以上因素的气象适宜度模型能较好地评价再生稻腋芽萌发期的气象影响。1981—2021年研究区气温适宜度、空气湿度适宜度及综合气象适宜度均呈下降趋势,降水适宜度没有表现出明显的变化趋势。气温适宜度、空气湿度适宜度及综合气象适宜度总体呈“西高东低”的空间分布特征,降水适宜度则表现为“东西高、中部低”。1981—2021年研究区气温上升趋势与空气湿度下降趋势显著,导致致害高温（日平均气温≥32℃）积温和致害低湿（日平均相对湿度≤65％）日数明显增加,这是再生稻腋芽萌发期气象适宜度总体呈下降趋势的诱因。     

The pattern,evolution, and mechanism of venture capital flows in the Guangdong-Hong Kong-Macao Greater Bay Area,China

As an important innovation flow, venture capital has been examined in urban network research. However, the segmentation of capital categories and the cross-scale connection of capital remain scarcely analyzed. This study focuses on the structure and industry differentiation of venture capital flows in the Guangdong-Hong Kong-Macao Greater Bay Area(GBA) and its cross-scale network characteristics. Based on a venture capital database covering capital amount, investment subject address information,...     

Compression behavior of MICP-treated sand with various gradations

Acta Geotechnica - One-dimensional compression tests on quartz sands treated by microbially induced carbonate precipitation (MICP) were carried out to evaluate the effects of gradation and calcium...     

Spatio-temporal variability in sea surface temperatures for the Yellow Sea based on MODIS dataset

The spatio-temporal variabilities in sea surface temperature (SST) were analyzed using a time series of MODIS datasets for four separate regions in the Yellow Sea (YS) that were located along a north-south axis. The space variant temporal anomaly was further decomposed using an empirical orthogonal function (EOF) for estimating spatially distributed SST. The monthly SSTs showed similar temporal patterns in each region, which ranged from 2.4°C to 28.4°C in the study years 2011 to 2013, with seasonal cycles being stronger at the higher latitudes and weaker at the lower latitudes. Spatially, although there were no significant differences among the four regions (p < 0.05) in any year, the geographical distribution of SST was characterized by an obvious gradient whereby SST decreased along the north-south axis. The monthly thermal difference among regions was largest in winter since the SST in the southeast was mainly affected by the Yellow Sea Warm Currents. The EOF1 mode accounted for 56% of the total spatial variance and exhibited a warming signal during the study period. The EOF2 mode accounted for 8% of the total variance and indicated the warm current features in the YS. The EOF3 mode accounted for 6% of the total variance and indicated the topographical features. The methodology used in this study demonstrated the spatio-temporal variabilities in the YS.     

Black band disease as a possible factor of the coral decline at the northern reef-flat of Yongxing Island,South China Sea

Black band disease(BBD),characterized by the Cyanobacterial dominated pathogenic consortium,is thought to play a key role in the global decline of the coral reef ecosystems.The present paper originally documents a case of BBD from Yongxing Island(Xisha Islands,South China Sea),and further probes the reasons of this abnormal phenomenon.Prior to 2007,corals at northern reef-flat of Yongxing Isand were in healthy growth.Catastrophic coral mortality occurred between 2007 and 2008.The 16S rRNA gene sequencing and PCR amplification,with universally conserved primers,were applied to detect the contagious bacterial community of the microbial mat.The results demonstrated that six bacterial divisions constituted the clone libraries derived from the BBD mat,and that Cyanobacteria are the most diversely represented group that inhabit BBD bacterial mats,despite the fact that species in five others divisions(α-Proteobacteria,γ-Proteobacteria,Bacteroidetes,Verrucomicrobia and Actinobacteria) are also consistently diverse within the BBD mats of diseased coral.Other factors such as coral bleaching,typhoons,ocean acidification and crown-of-thorns starfish outbreaks,are not primarily responsible for the coral mortality within such a short time interval.The disaster expansion of BBD associated with Cyanobacterial blooms is a more likely mechanism impacting these coral reefs.Excessive human activity enhances the eutrophication of the marine water of the reefal region and may result in occurrence of the BBD.     

东格陵兰盆地油气资源评价

东格陵兰盆地陆上和近海地区是目前北极与深水油气勘探的热点地区,但油气勘探程度和资源认识程度低。美国地质调查局(2000、2007年)油气资源评价结果表明该区具有很大的油气资源潜力,同时油气勘探具有高风险和不确定性。通过收集整理东格陵兰盆地、北海盆地油气地质资料及油气田勘探开发数据,从区域上对两个地区的油气成藏条件进行了对比,并采用地球化学方法与类比法,评价了东格陵兰盆地的油气资源潜力。东格陵兰盆地属于晚古生代—中生代的裂谷盆地,呈现两坳一隆的构造格局,与挪威陆架盆地在进入被动陆缘阶段之前具有相同的地质发育过程,沉积环境类似,共同经历古生代和中生代裂谷及裂后的热沉降。东格陵兰盆地发育晚古生代湖相烃源岩、上侏罗统海相烃源岩,储层主要为中侏罗统浅海相砂岩和白垩系深海浊积砂岩,圈闭类型主要为伸展构造圈闭、地垒断块圈闭、盐构造圈闭以及地层圈闭等。东格陵兰盆地油气成藏条件优越,油气资源潜力较大,具有较好的勘探前景。在影响东格陵兰盆地油气资源认识的诸多地质因素中,有利圈闭类型、必要数量的烃源岩以及油气生成条件和适当埋藏史还待进一步证实。     

莱州湾地区10万年以来沉积环境变化

本文用热释光测年和地球化学标志法研究了莱州湾地区沉积环境的变化。石英的375℃热释光峰作为测年基础。岩芯样品的测定结果、反映了自全新世(1.2万年)至晚更新世(11万年)地层的年代特点。实验中来用了Sr/Ba、Rb、Mn/Fe和CaO作为地球化学标志,所得数据经Sheppard方程和Fisher判别处理。在得到的沉积环境变化曲线和大洋δ~(18)O曲线对比中可以看出,本区在十万年以来出现过三次海陆相地层变化序列,其中在距今11—7万年和深度为43.5—60m处,在距今4.6—2.1万年和深度为23—35m处,以及在距今1.1—0.6万年和深度为8—11m处出现过三次海相地层,分别与沧州、献县和黄骅海侵事件相应,并同时受到全球气候变化的控制。     

The 2020/21 Extremely Cold Winter in China Influenced by the Synergistic Effect of La Niña and Warm Arctic

In the first half of winter 2020/21,China has experienced an extremely cold period across both northern and southern regions,with record-breaking low temperatures set in many stations of China.Meanwhile,a moderate La Ni?a event which exceeded both oceanic and atmospheric thresholds began in August 2020 and in a few months developed into its mature phase,just prior to the 2020/21 winter.In this report,the mid?high-latitude large-scale atmospheric circulation anomalies in the Northern Hemisphere,which were forced by the negative phase of Arctic Oscillation,a strengthened Siberian High,an intensified Ural High and a deepened East Asian Trough,are considered to be the direct reason for the frequent cold surges in winter 2020/21.At the same time,the synergistic effect of the warm Arctic and the cold tropical Pacific(La Ni?a)provided an indispensable background,at a hemispheric scale,to intensify the atmospheric circulation anomalies in middle-to-high latitudes.In the end,a most recent La Ni?a prediction is provided and the on-coming evolution of climate is discussed for the remaining part of the 2020/21 winter for the purpose of future decision-making and early warning.     

中国大洋生物基因研究开发基地成立

2002年6月28日,“中国大洋生物基因研究开发基地”在厦门国家海洋局第三海洋研究所(下称海洋三所)成立,并正式挂牌。“基地”在中国大洋矿产资源研究开发协会(下称中国大洋协会)和海洋三所的相关研究方向基础上建立,目的是把中国大洋生物基因研究开发方面的工作推向深入和提高到一个新水平。国家海洋