Three new species of Batrachospermum Roth (Batrachosper-maceae,Rhodophyta) in China

1 INTRODUCTION The first published records of genus Batra-chospermum Roth in China are from Jao (1941), when eleven taxa were reported. Since then, Shi, Hu and Kumano (1993), Shi (1994a, 1994b), Hua and Shi (1996), Xie et al. (1999, 2003), Xie and Shi (2003) have described in more detail the species from China. To date, 23 taxa of Batrachospermum Roth in China have been reported, of which, B. yunnanense, B. nothocladoideum and B. transito-rium are new species of this genus, and are…     

“知音”中的同情体验与孤独体验——《文心雕龙》鉴赏批评论的美学生命探微

刘勰倾注其毕生的追求与思索而创作的体大思精的《文心雕龙》正是其美学生命与心理体验的显现。刘勰将其在独特的人生旅途中获得的心理体验贯穿于《文心雕龙》的文道论、创作论、鉴赏批评论和文体论之中,其中,"割情析采"中的鉴赏批评论蕴含了刘勰的"觇文见心"的同情体验、"贵古贱今"的孤独体验以及这两种体验的实践与超越,这些共同构成了其丰富深刻又灵动精妙的心理体验与美学生命。     

一种计算地下结构地震主动土压力的新方法

针对目前地下结构地震土压力设计方法的研究现状,介绍了计算挡土墙地震主动土压力的物部·冈部公式及浅埋隧道谢家然围岩压力理论。并结合物部·冈部公式、谢家然理论提出了一种适用于计算地下结构地震土压力的新方法。该方法基于极限平衡理论,根据谢家然理论提供的滑裂面参数构造了滑动土体,采用物部·冈部公式计算了滑动土体作用在地下结构边墙上的地震土压力。最后结合工程实例,将本文方法与其它计算方法进行了比较,评价了该计算方法的优缺点。     

内蒙古陈巴尔虎旗谢尔塔拉铁锌矿床成矿流体演化与成矿作用

内蒙古谢尔塔拉铁锌矿床位于大兴安岭中段华力西期、燕山期成矿带上,是一个大中型的火山喷发沉积-热液富集型矿床。在对谢尔塔拉铁锌矿床的物质组成分析的基础上,着重对流体包裹体和稳定同位素进行分析,以此来研究该矿床的成矿流体演化和成矿作用。研究表明,从热液作用早期到中期,具有成矿温度递减、盐度升高的趋势,两者呈负相关变化,指示流体发生了沸腾作用;从热液作用中期到晚期,具有成矿温度递减、盐度降低的趋势,两者呈正相关变化,指示流体发生了混合作用。S、Pb、C、H、O同位素组成表明,金属物质主要来自赋矿岩石和下伏地层,同时还有深部岩浆物质的参与。成矿热液为大气降水补给加热的循环地下水和岩浆水组成的的混合流体,后期又有大量的大气降水补充,使得成矿流体与围岩发生了强烈的同位素交换。矿化和蚀变作用是在水/岩比值比较低的体系中进行的。谢尔塔拉铁锌矿床的成矿流体总体表现为中低温、低盐度、低密度的热液。构造热效应、地热梯度和多次的岩浆喷气热是驱动流体活化迁移的主要因素。构造体制转换使流体稳定体系发生改变,压力释放发生沸腾作用,造就铁、锌在有利位置富集成矿。     

Record Arctic Ozone Loss in Spring 2020 is Likely Caused by North Pacific Warm Sea Surface Temperature Anomalies

Record ozone loss was observed in the Arctic stratosphere in spring 2020. This study aims to determine what caused the extreme Arctic ozone loss. Observations and simulation results are examined in order to show that the extreme Arctic ozone loss was likely caused by record-high sea surface temperatures(SSTs) in the North Pacific. It is found that the record Arctic ozone loss was associated with the extremely cold and persistent stratospheric polar vortex over February–April, and the extremely cold vortex was a result of anomalously weak planetary wave activity. Further analysis reveals that the weak wave activity can be traced to anomalously warm SSTs in the North Pacific. Both observations and simulations show that warm SST anomalies in the North Pacific could have caused the weakening of wavenumber-1 wave activity, colder Arctic vortex, and lower Arctic ozone. These results suggest that for the present-day level of ozone-depleting substances, severe Arctic ozone loss could form again, as long as certain dynamic conditions are satisfied.     

内蒙古陈巴尔虎旗谢尔塔拉铁锌矿床成矿流体演化与成矿作用

内蒙古谢尔塔拉铁锌矿床位于大兴安岭中段华力西期、燕山期成矿带上,是一个大中型的火山喷发沉积-热液富集型矿床。在对谢尔塔拉铁锌矿床的物质组成分析的基础上,着重对流体包裹体和稳定同位素进行分析,以此来研究该矿床的成矿流体演化和成矿作用。研究表明,从热液作用早期到中期,具有成矿温度递减、盐度升高的趋势,两者呈负相关变化,指示流体发生了沸腾作用;从热液作用中期到晚期,具有成矿温度递减、盐度降低的趋势,两者呈正相关变化,指示流体发生了混合作用。S、Pb、C、H、O同位素组成表明,金属物质主要来自赋矿岩石和下伏地层,同时还有深部岩浆物质的参与。成矿热液为大气降水补给加热的循环地下水和岩浆水组成的的混合流体,后期又有大量的大气降水补充,使得成矿流体与围岩发生了强烈的同位素交换。矿化和蚀变作用是在水/岩比值比较低的体系中进行的。谢尔塔拉铁锌矿床的成矿流体总体表现为中低温、低盐度、低密度的热液。构造热效应、地热梯度和多次的岩浆喷气热是驱动流体活化迁移的主要因素。构造体制转换使流体稳定体系发生改变,压力释放发生沸腾作用,造就铁、锌在有利位置富集成矿。     

VERTICAL SLIP RATE OF MINLE-DAMAYING FAULT INDICATED BY SCARPS ON TERRACES OF DONGDA RIVER

The Qilianshan north-edge thrust (QNT)is located at the boundary between the northern margin of the Qilianshan mountain and Hexi Corridor, with a length over 700km. The Minle-Damaying fault (MDF), trending NWW, is part of the eastern section of the QNT, cutting through the Minle and Wuwei Basins. Hexi Corridor is a region of intense seismic activities, where many large earthquakes have been documented in history, such as the M7.5 Gaotai earthquake in 180, M8.5 Haiyuan earthquake in 1920, M8.0 Gulang earthquake in 1927 and the M7.6 Changma earthquake in 1932. While, there is no seismic record on the MDF. The Dongda River flows across the MDF from south to north. One of the tributary of the Dongda River, Xie River, has very well preserved terraces (T₆-T₁)which were offset by the MDF. On these terraces, there is clear trace of scarps, of which the height increases from terraces T₃ to T₆, indicating an accumulation of offset with time. In order to acquire the cross-section of scarps, unmanned aerial vehicle (UAV)scanning was implemented. With a digital camera mounted on, the UAV scanned an area of 0.52km² and digital elevation model (DEM)was generated with an accuracy of 0.2m vertically. The Thompson's method was utilized to conduct linear regressions on both the hanging wall and foot wall of the fault. The difference between the intercepts of the regression lines with the vertical line going through the intersection of the scarp surface on the fault surface is considered as the vertical offset. Terraces from T₆ to T₃ are very well preserved where MFD intercepts the Xie river, while T₂ and T₁ are badly eroded at the same location. Utilizing the cross-sections extracted from high resolution DEM, we estimate that the vertical offsets of T₆-T₃ are 13.26~15.67m, 9.74~10.13m, 5.86~7.35m and 5.03~5.60m, respectively, with 95%confidence interval. From the offsets of terraces, at least 4 paleo-seismic events are indentified. Terraces were dated by the AMS ¹⁴ C dating, yielding ages (cal BP)of T₆-T₂ as (16 405±210)a, (111 975±21)a, (5 697.5±210)a, (4 470.5±54.5)a and (3 137.5±77.5)a. Liner regression was performed for the relation between the ages and the offsets of terraces, resulting in the average vertical slip rate of MDF since the formation of T₆ as 0.91 average v. As the dip of MDF is about 35°, the shortening rate is estimated to be (1.3±0.13)mm/a. This study provides important parameters for the analysis of seismic activity in heavily populated Minle and Yongchang areas.     

西藏谢通门斯弄多地区新生代逆冲推覆构造的基本特征

谢通门县斯弄多地区发育大型新生代逆冲推覆构造,逆冲断层面倾向200°左右,断层倾角15～25°。逆冲断层上盘主要由上石炭统昂杰组灰岩、白云质灰岩构成,形成陡峭高耸的推覆前缘断崖;下盘以始新统年波组火山岩为主。断层全长约60km,断层带宽2～3km。逆冲推覆上盘推覆体向北北东方向滑移,根据飞来峰的相对位置估算,推覆体推覆距离约15km。逆冲推覆构造的形成可能与印度板块向北俯冲导致冈底斯地区强烈的陆内挤压作用有关。     

Three new species of Batrachospermum Roth （Batrachospermaceae, Rhodophyta） in China

Three new species of Batrachospermum Roth (Batrachospermales, Rhodophyta) from China are described in this paper. B. yunnanense sp. nov. has long-cylindrical trichogynes with long stalks and is diagnostic of section Virescentia. Within this section, B. yunnanense is similar to B. helminthosum Bory emend. Sheath et al., but it is dioecious and has curved carpogonial branches, while the latter is monoecious and has straight carpogonial branches. It is also similar to B. transtaganum Reis, but it differs from the latter in long carpogonia,big carposporophytes and carposporangia. It is considered that B. nothocladoideum sp. nov. is assigned to section Contorta, subsection Kushiroense, because its carpogonial branches are twisted and gonimoblast filaments are loosely agglomerated. This new species similar to B. iriomotense Kumano, but with short fascicles, long-ovoid or subpyriform cells, numerous terminal hairs, long-ellipsoid trichogynes, big carposporophytes and small carposporangia. The plant is quite tough and cartilaginous and similar to Nothocladus in gross morphology, but its carposporophytes are compact instead of diffuse. This shows that it may be a transitional species between section Contorta and genus Nothocladus. So, B. transitorium sp. nov. should belong to section Contorta, subsection Kushiroense, because of its curved or twisted carpogonial branches and loosely agglomerated gonimoblast filaments, with globose or subglobose cells in fascicles similar to B. spermatiophorum Vis et Sheath, but no colourless spermatiophores. In terms of small and numerous carposporophytes, B. transitorium sp. nov. is similar to some species of section Batrachospermum. However, their other features are unique, indicating its transitional nature between section Contorta and Batrachospermum.     

协尔苏盆地聚煤环境与构造格架分析

从收集整理资料入手,系统地分析了协尔苏盆地聚煤环境与构造格架,即协尔苏盆地为晚侏罗世-早白垩世地堑式聚煤盆地;聚煤作用取决于盆地沉积环境与古构造环境;是湖泊淤浅沼泽化环境成煤;盆地垂向沉积序列与盆地构造演化阶段相一致;盆地沉降轴心与沉积中心均显示南北向展布。