山西轩岗矿区焦家寨井田构造特征及形成机制

轩岗矿区焦家寨井田位于宁武煤田东北部,构造位置上处在山西块体北部中段、吕梁山凸起和恒山-五台山隆起之间,属于宁（武）-静（乐）向斜组成单元之一,本井田地处该向斜东北仰起端的东南翼上。经地面勘察及井下揭露,井田发育有两组断层,一组与地层及煤层倾向一致,另一组与煤层倾向相反;上、下煤组中的断层产状相近,但互不连通,发育程度也有差异;井田内岩层层面上的滑动痕迹随处可见,层间断层发育,综合评价井田地质构造复杂程度为中等-复杂。由于井田构造断层发育,将成为现代化机械采煤的重大障碍,直接影响矿井生产,因此加强断层预测工作,对矿井建设及生产具有一定指导意义。     

遵义市近10 a来降温频次及强度分析

选取遵义市13个国家站2010—2019年逐日日最低气温资料,将降温过程分为弱降温、较强降温、强降温、寒潮4个等级,分析了各级降温过程的频次、持续日数、降温幅度、过程最低气温、空间分布等特征。分析表明：① 10 a来遵义市共发生降温过程11 915站次,平均每站每年91.7次,以降温幅度在6 ℃以下的弱降温为主。②近10 a遵义市平均过程降温幅度为3 ℃,平均过程最低日低温11.9 ℃,持续时间在1~10 d之间,寒潮、强降温、较强降温持续天数以2~3 d为主,弱降温过程大多持续1 d。③不同等级降温频次空间分布与地形相关,较强降温以上的降温过程主要集中出现在遵义市娄山以南地区,弱降温主要出现在娄山山区及其西北部。④寒潮、强降温、较强降温主要出现在春秋季,寒潮主要出现在3月份,而弱降温在夏季发生频次较高,4月份是遵义市降温最剧烈的时候。     

Genesis and mineralization of gold-bearing quartz veins in the Xiao Qinling area, central China

Gold-bearing quartz veins of the Taihua Group consisting of Archean metavolcanic rocks are a main gold deposit type in the Xiao Qinling area,one of the three biggest gold production areas in China.The quartz veins experienced strong alteration characterized by a typical mesothermal hydrothermal altered mineral assemblage.The grade of gold is affected by the contents of sulphides,e.g.galena,pyrite and chalcopyrite.Results of minor elements analysis for the of gold-bearing quartz veins indicate higher contents of Au and high contents of Ag,Pb,Cu,Cd,W,and Mo.Abundant fluid inclusions were found in the gold-bearing quartz veins.Three types of fluid inclusions were identified:(1) aqueous inclusions;(2) CO 2-bearing inclusions;and(3) daughter crystal-bearing fluid inclusions.Homogenization temperatures ranged from 110 to 670℃ with low and high peaks appearing at 160 180℃ and 280 300℃,respectively.The salinity of aqueous inclusions varies between 1.8 wt% and 38.2 wt% NaCl.The homogenization temperature and salinity show a positive correlation.The H and O isotopes of fluid inclusions in the gold-bearing quartz veins indicate that magmatic solution and metamorphic hydrothermal solution,together with meteoric water,were involved in the formation of gold-bearing fluid.Mesozoic magma activities related to granite intrusions should be the main source of CO 2 fluid with higher temperature and salinity.     

Geochemical records of decadal variations in terrestrial input and recent anthropogenic eutrophication in the Changjiang Estuary and its adjacent waters

Increasing eutrophication and seasonal anoxia in bottom water in the Changjiang Estuary and its adjacent waters has progressed in recent decades, caused by elevated anthropogenic N and P input. Sedimentary biogenic elements were investigated to determine whether the biogenic proxies could be used in paleoenvironmental studies in an energetic estuary, as well as to reconstruct the histories of environmental changes in the East China Sea (ECS). Two ²¹⁰Pb-dated cores from the coastal and offshore waters were analyzed for organic C (TOC) and its stable isotope (δ¹³C), total N (TN), biogenic Si (BSi), total P (TP) and P species. In coastal sediment, the variations of P species, especially Fe-P, Al-P and detrital apatite P (Det-P), reflected the dry–wet oscillations in the Changjiang River for the past century, which has influenced the sediment grain size and terrestrial material input. Much lower BSi content (0.756%) at 16–22 cm likely recorded the pronounced decrease in silicate flux in the Changjiang River and its lower flow in the late 1980s. In offshore sediment, higher concentrations of TOC, TN, BSi, Ex-P, Fe-P and Lea-OP indicated higher primary productivity in response to the strong winter monsoons during the 1960s–1980s, and their 20-a fluctuations were in agreement with the decadal variations of the winter monsoon. Low contents and little variations of Al-P and Det-P indicated the slight influence of the terrestrial sediment input in offshore waters. The influence of human activities on the environment in recent decades has also been recorded in coastal sediment. Grain-size normalized concentrations of TOC, TN, TP, Ex-P, Fe-P and Lea-OP increased by 24%, 23%, 15%, 13% and 51% in the upper 16 cm of coastal sediment, indicating elevated P and N load and primary productivity since the 1990s. Elevated TN/TP ratios and decreased BSi/TOC recorded the changed nutrient structure and the decrease in the proportion of the diatom to phytoplankton community. However, the sediment record indicated that the eutrophication might actually have started from the end of the 20th century rather than the reported middle of 20th century. In contrast, biogenic elements in offshore sediment did not reflect disturbance by human activities. This study revealed that multi-nutrient proxies in sediment in the ECS could indicate natural environmental changes including runoff and the winter monsoon over the past century, as well as the influence of human activities in recent decades. Phosphorus species with distinct origins and biogeochemical behaviors could effectively reflect different aspects of past environmental conditions.     

青藏高原冬春积雪影响亚洲夏季风的研究进展

青藏高原积雪作为亚洲夏季降水异常的一个预测因子已有很长历史。统计分析表明,青藏高原冬春积雪与印度夏季降水反相关,与我国长江中下游夏季降水多为正相关,不同作者对此现象给出了一些可能的解释,如地表反照率效应和积雪一水文效应。但积雪的这种跨季节滞后影响的具体物理过程仍有争议。另一方面,青藏高原冬春积雪资料存在不确定性,这对相关物理机制的理解造成了很大困难。通过回顾和梳理前人在该领域的研究成果,提出了高原积雪影响亚洲季风的未来研究方向。     

2020年中国大陆地震灾害损失述评

本文在统计分析2020年中国5.0级以上地震目录的基础上,结合有关省（自治区、直辖市）地震局地震灾害损失评估资料,总结2020年中国大陆地震灾害情况和主要特点。总体全年地震灾害程度较轻,但小震致灾致亡的现象突出。将1991—2020年中国大陆地震灾害相应数据和特性进行比较,得到中国大陆致灾地震频次、伤亡情况和经济损失变化趋势。     

ArcGIS点符号库向QGIS平台迁移的实现

地图符号在各GIS平台之间存在的差异导致符号交换、共享困难, 本文以点状地图符号为基础, 分析了ArcGIS与QGIS平台中常用地图符号的格式结构差异; 通过Python编程设计符号转换方式, 将TTF转换为SVG图片格式, 使用标记组合的方法完成点符号制作。通过该方法转换的QGIS点状地图符号具备与ArcGIS相同的功能, 转换后的符号能够满足QGIS的制图要求, 实现了由ArcGIS到QGIS平台的点符号完整迁移, 节省了人工制作符号所消耗的时间。本文提出的符号转换方法在实际应用中能够满足地震行业相关业务需求, 在其他行业和GIS制图领域也具有良好的发展前景。     

Effects of blue light on gametophyte development of Laminaria japonica (Laminariales, Phaeophyta)

Laminaria gametophyte was greatly influenced by light in its growth and development. Using light-emitting diodes (LED) as blue and red light sources, we analyzed the light effect on gametophytes development ofLaminaria japonica Aresch. The gametophytes were obtained from zoospores collected in April, May, July, 2003 and September, 2004. We found that the growth of gametophytes was stimulated by increasing intensity of blue light (BL) and red light (RL) illumination, of which BL was obviously stronger than that of RL. The fertilization of gametophytes depended largely on BL, and only sufficient BL illumination could take the reproductive effect. In addition, we noticed that there was a significant difference in light responses for gametophytes developed from zoospore collected in different times. For zoospores released in April, under BL₁ (73.90 μmol photons/m·s), the unicellular female gametophytes and multi-cellular male gametophytes produced eggs and sperms respectively, and further developed towards sporophytes. However, for gametophytes developed in May, July or September, they became multi-cellular and never formed oogonia or antheridia. It is believed that theLaminaria sporangium maturation stage could affect the gametophytes reaction to BL under laboratory culture conditions. Therefore, cryptochrome- or phototropin-like BL photoreceptors is probably involved in BL-induced development ofLaminaria gametophytes. This research was supported by the NSFC (No.40376049) and Japan Society for the Promotion of Science (The Invitation Fellowship for Research in Japan 2002).     

Observation of female gamete (Carpogonia) germination of Porphyra yezoensis and P. oligospermatangia

Several papers have reported that part or whole leafy thallus seemingly consisting of zygotospores can give rise to both blades and conchocelis in the same culture ofPorphyra. Study on samples of wild and cultivatedPorphyra yezoensis andP. oligospermatangia were conducted to clarify the origination of the young blades in the culture. It is confirmed that single cells on the blade of both species, which normally intermixed with zygotospores, germinated into young blades. TEM and SEM observation has shown that the single cells ofPorphyra yezoensis had typical features of female gamete (carpogonia) but archeospore. Therefore, the female gametes are responsible in developing leafy thalli. This project was sponsored by the NSFC (No. C-0205-05-39770593)     

A new method for testing pile by single-impact energy and <Emphasis Type="Italic">P-S</Emphasis> curve

By studying the pile-formula and stress-wave methods (e.g., CASE method), the authors propose a new method for testing piles using the single-impact energy and P-S curves. The vibration and wave figures are recorded, and the dynamic and static displacements are measured by different transducers near the top of piles when the pile is impacted by a heavy hammer or micro-rocket. By observing the transformation coefficient of driving energy (total energy), the consumed energy of wave motion and vibration and so on, the vertical bearing capacity for single pile is measured and calculated. Then, using the vibration wave diagram, the dynamic relation curves between the force (P) and the displacement (S) is calculated and the yield points are determined. Using the static-loading test, the dynamic results are checked and the relative constants of dynamic-static P-S curves are determined. Then the subsidence quantity corresponding to the bearing capacity is determined. Moreover, the shaped quality of the pile body can be judged from the formation of P-S curves.