New approaches for archaeal genome-guided cultivation

Archaea, one of the three domains of life along with Bacteria and Eukarya, contains ancient life forms such as methanogen that are observed today on Earth, and one lineage Asgard archaea is also considered the closest ancestor of Eukarya.Recently, with the development of interdisciplinary studies from Earth and Life sciences, archaeal organisms are considered to play pivotal roles in geochemical cycling in nature. However, our understanding of the attributes, origin and evolution, geochemical and ecological functions of Archaea is hampered by the scarcity of archaeal isolates, which has represented a challenge to researchers for the last 40 years. Cultivation-independent sequencing and phylogenomic analyses have demonstrated a considerable diversity of Archaea with more than 20 novel phyla. However, only four archaeal phyla have cultured representatives, leaving large gaps in our knowledge of the metabolic capabilities and ecological functions of the majority of archaeal strains identified exclusively by DNA sequencing. In this review, we summarize the discovery and development of archaeal research, highlight the knowledge gap between uncultured and cultured archaeal microbes, and call on the importance of devoting greater research efforts to archaeal cultivation. Finally, we outlined new ideas and strategic approaches, namely,(1)genome-based methods,(2) microbial network information-based methods,(3) genome-scale model-guided methods, and(4)machine learning methods, to enable the cultivation of uncultivated archaeal microbes using accumulated high-throughput sequencing data.     

Tectonics of the offshore Red River Fault recorded in the junction of the Yinggehai and Qiongdongnan Basins

Science China Earth Sciences - The Red River Fault, which originated from the southeastern margin of the Tibetan Plateau, has a great significance for obtaining a further understanding of the...     

北太平洋500hpa候高度场的主成分分析

对太平洋500hPa候高度场和距平场进行了主成分分析,得出反映500hPa候高度特征的典型场。指出候高度场的第1特征向量的空间型是季节变化的主要型,它可解释总方差的74.5％,候高度场的其余特征向量与距平场的特征向量是按顺序的对应相似。这些典型场可以很好地描述北太平洋的大气环流特征。距平场的第1特征向量空间型清楚地反映了与厄尔·尼诺现象有关的环流型。     

绝对差分算法误差对测大气视宁度的影响分析

对绝对差分算法检测太阳边缘的起伏测量白日视宁度的方法进行了研究,并对绝对差分的结果进行二阶拟合使之可以达到亚像素的检测精度。对可能的影响因素如噪声和像差等进行了分析和数值模拟,算法的精度优于0．1”。模拟结果表明,采用绝对差分算法可以对白日视宁度进行高精度的测量,最后用绝对差分算法对实际数据进行了处理,给出了初步结果。     

Morphological analysis on the coherence of kHz QPOs

We take the recently published data of twin kHz quasi-period oscillations (QPOs) in neutron star (NS) low-mass X-ray binaries (LMXBs) as the samples, and investigate the morphology of the samples, which focuses on the quality factor, peak frequency of kHz QPOs, and try to infer their physical mechanism. We notice that: (1) The quality factors of upper kHz QPOs are low (2～20 in general) and increase with the kHz QPO peak frequencies for both Z and Atoll sources. (2) The distribution of quality factor versus frequency for the lower kHz QPOs are quite different between Z and Atoll sources. For most Z source samples, the quality factors of lower kHz QPOs are low (usually lower than 15) and rise steadily with the peak frequencies except for Sco X-1, which drop abruptly at the frequency of about 750 Hz. While for most Atoll sources, the quality factors of lower kHz QPOs are very high (from 2 to 200) and usually have a rising part, a maximum and an abrupt drop. (3) There are three Atoll sources (4U 1728-34, 4U 1636-53 and 4U 1608-52) of displaying very high quality factors for lower kHz QPOs. These three sources have been detected with the spin frequencies and sidebands, in which the source with higher spin frequency presents higher quality factor of lower kHz QPOs and lower difference between sideband frequency and lower kHz QPO frequency.     

甲烷气爆震源性能研究及其在粤港澳大湾区化龙断层探测中的应用

针对近年兴起的甲烷气爆主动震源,设计了不同尺寸震源装置,分别在不同激发环境下,通过比较激发信号能量及频带分布进行了震源性能研究,实现了震源参数优化.同点甲烷气爆和炸药震源成像结果研究表明,甲烷气爆震源引起的地表振动速度更小,更符合安全环保的需求.将优化后的甲烷气爆震源用于粤港澳大湾区的化龙断裂浅部结构勘查,单炮记录结果可见高信噪比初至信号.对 10炮激发记录进行初至走时拾取后进行走时层析成像发现,化龙断裂推测位置附近纵波速度在第四系下方 200～400 m深度范围明显错断.基于横波/纵波波谱比分析结果(HVSR),根据经验关系推断了该地区沉积层厚度分布,发现与走时层析成像结果中的第四系沉积底界面位置吻合良好.以上成像结果与该地区已有钻孔及早期反射地震结果高度吻合,证明了此次采用的甲烷气爆主动震源作为炸药震源的替代品,在未来城市地下结构浅勘工作中有广泛的应用前景.     

青海玛多7.4级地震极震区震灾调查及分析

2021年5月22日2时4分,青海省玛多县发生7.4级地震,距震中26 km的野马滩大桥及周边区域为此次地震极震区（地震烈度Ⅹ度,面积约69 km2）,受损尤为严重。桥梁表现为落梁式破坏,房屋不同程度受损。对极震区内野马滩大桥及周边房屋进行实地调查与震灾分析,并提出灾后重建及震灾防御相关建议,包括组织专业人员进行灾区房屋安全鉴定,建议牧民居住建筑采用轻钢式结构,建议原地重建野马滩大桥并增加限位装置及连梁装置。     

The Effect of AGN and SNe Feedback on Star Formation, Reionization and the Near Infrared Background

Feedback from supernovae (SNe) and from active galactic nuclei (AGN) accom-panies the history of star formation and galaxy evolution. We present an analytic model to explain how and when the SNe and AGN exert their feedback effects on the star formation and galaxy evolution processes. By using SNe and AGN kinetic feedback mechanisms based on the Lambda Cold Dark Matter (LCDM) model, we explore how these feedback mecha-nisms affect the star formation history (SFH), the Near-Infrared Background (NIRB) flux and the cosmological reionization. We find the values of the feedback strengths, ∈AGN =1.0+0.50.3and ∈SN=0.04+0.02-0.02, can provide a reasonable explanation of most of the observational re-suits, and that the AGN feedback effect on star formation history is quite different from the SNe feedback at high redshifts. Our conclusions manifest quantitatively that these feedback effects decrease star formation rate density (SFRD) and the NIRB flux (in 1.4 - 4.0μm), and postpone the time of completion of the cosmological reionization.     

Energy transition,CO2 mitigation,and air pollutant emission reduction: scenario analysis from IPAC model

The salinization of freshwater-dependent coastal ecosystems precedes inundation by sea level rise. This type of saltwater intrusion places communities, ecosystems, and infrastructure at substantial risk. Risk perceptions of local residents are an indicator to gauge public support for climate change adaptation planning. Here, we document residential perspectives on the present and future threats posed by saltwater intrusion in a rural, low-lying region in coastal North Carolina, and we compare the spatial distribution of survey responses to physical landscape variables such as distance to coastline, artificial drainage density, elevation, saltwater intrusion vulnerability, and actual salinity measured during a synoptic field survey. We evaluate and discuss the degree of alignment or misalignment between risk perceptions and metrics of exposure to saltwater intrusion. Risk perceptions align well with the physical landscape characteristics, as residents with greater exposure to saltwater intrusion, including those living on low-lying land with high concentrations of artificial drainages, perceive greater risk than people living in low-exposure areas. Uncertainty about threats of saltwater intrusion is greatest among those living at higher elevations, whose properties and communities are less likely to be exposed to high salinity. As rising sea levels, drought, and coastal storms increase the likelihood of saltwater intrusion in coastal regions, integrated assessments of risk perceptions and physical exposure are critical for developing outreach activities and planning adaptation measures.

     

柴达木盆地英西地区渐新统硫酸盐硫同位素组成及其地质意义

对柴达木盆地英西地区渐新统沉积环境和硫酸盐硫同位素组成进行了研究,刻画了硫化氢气体的形成机理及其对储层的改造作用,提出英西地区渐新统发生的TSR为其硫酸盐硫同位素组成的主控因素之一,并对储集层物性具有一定的改善作用。主要取得3项进展:①研究区为干旱气候、缺氧还原环境的咸化半深深湖沉积。Sr/Ba平均值为6.71,Fe/Mn平均值为44.35,(Fe+Al)/(Ca+Mg)平均值为0.45,以咸化半深—深湖沉积为主;Sr/Cu平均值为148.24,为干旱气候;U/Th平均值为0.55, w(V+Ni+Mn)平均值为495.77μg/g, V/(V+Ni)平均值为0.63,Ni/Co平均值为2.28,Cu/Zn平均值为1.00,为缺氧还原环境;②研究区硫酸盐硫同位素δ~(34)S偏重,主要受控于沉积环境和TSR硫同位素的分馏作用。硫酸盐种类主要包括硬石膏、芒硝、钙芒硝、天青石和重晶石等,以硬石膏分布最为广泛,其硫同位素δ~(34)S平均值为32.23‰,较同期海水明显偏重;③TSR对储集层物性、孔隙的连通具有一定的改善作用。TSR的产物H_2S具有较强的溶蚀能力,可进入酸性流体难以进入的极小空间进行溶蚀改造,虽然其伴生的方解石沉淀可占据一定量的储集空间,但硫酸盐的消耗可产生一定量的次生孔隙,对储集层物性起到改善作用。