淮南煤田丁集井田B组煤中硼元素与沉积环境演化分析

为了查清丁集矿区B组煤层的沉积环境及其赋存规律,对井田内3个补勘钻孔中142件煤样进行了测试分析,特别对硼元素的分布特征及其沉积环境进行了详细的探讨与分析,结果表明:从4-1煤至8煤硼元素呈现总体下降的趋势;B组煤层沉积在以咸水为主导的多变环境下,且大部分煤层沉积在半咸水—咸水的环境中;多变的沉积环境致使B组煤中部分煤层出现分叉与合并现象、其厚度较薄且间距较小。     

淮南煤田深部煤的孔隙特征及其意义

从压汞试验入手,对淮南煤田煤的孔隙结构随埋藏深度的变化进行分析,根据大量实验数据得到以下认识:随采样深度的增大,煤中总比孔容积呈减小趋势,其中大孔的比孔容积在总比孔容积中所占比率逐渐减小,微孔的比孔容积在总比孔容积中所占比率显示增大趋势;随埋藏深度增加,煤的孔隙率有减小迹象,煤的真密度和视密度呈线性增加。煤内微孔的增多使煤吸附瓦斯的容量相对增多。深部煤与其顶板和底板岩石的力学性质的差异减小,使深部煤层厚度的稳定性增加。     

漂白粉消毒后对虾养殖源水细菌群落的响应特征研究

漂白粉消毒是凡纳滨对虾养殖源水常见的管控措施, 可有效控制病原菌传播; 然而,消毒会强烈扰动水体微生物群落,但源水细菌群落对漂白粉消毒的响应特征尚未阐明。在室内条件下, 设置高浓度(60 mg/L)和低浓度(20 mg/L)漂白粉消毒源水, 通过高通量测序及荧光定量PCR技术探究消毒后源水细菌群落、病原菌及抗生素抗性基因(ARGs)的动态响应规律。结果显示, 消毒后, 拟杆菌门(Bacteroidota)丰度上升, 高浓度组变形菌门(Proteobacteria)的丰度显著降低; 至第3天, 两组源水的细菌群落组成趋于一致。此外, 漂白粉消毒显著改变了源水的细菌群落结构及共现网络的复杂性。在控制水体病原菌方面, 消毒后病原菌的总丰度降低, 但种类增加, 高浓度漂白粉消毒对病原菌的抑制作用更加显著。漂白粉消毒对ARGs的去除具有选择性, 仅对sul1、floR、cfr、tetQ有一定的去除作用, 且高、低浓度对ARGs的去除无差异。综上, 60 mg/L可以作为漂白粉消毒养殖源水的更好浓度选择。研究结果从微生物生态视角评价了不同浓度漂白粉的消毒作用, 可为对虾养殖生产中的源水管控提供理论支撑。     

Receiver function analysis for seismic structure of the crust and uppermost mantle in the Liupanshan area,China

A portable broadband seismic array was deployed from the northeast Tibetan Plateau to the southwest Ordos block, China. The seismic structure of the crust and uppermost mantle of the Liupanshan area is obtained using receiver function analysis of teleseismic body waves. The crustal thickness and Poisson’s ratios are estimated by stacking the weighted amplitudes of receiver functions. Our results reveal complex seismic phases in the Liupanshan area, implying intense deformation at the boundary between the Tibetan Plateau and the Ordos block. The average crustal thickness is 51.5 km in the northeast Tibetan Plateau, 53.5 km in the Liupan Mountain and 50 km in the southwest Ordos block, resulting in a concave Moho beneath the Liupan Mountain. The Poisson’s ratio of the Liupanshan area varies between 0.27–0.29, higher than the value of 0.25–0.26 to the east and west of the Liupan Mountain, suggesting partial melting in the lower crust. The variance in Poisson’s ratio across the Liupan Mountain indicates notable changes in the crustal composition and mechanical properties, which may be formed by the northeastward flow of the Tibetan lower crust during the India-Eurasia collision.

     

下扬子无为盆地异常高压富氦天然气的发现及其成藏地质条件

在无为盆地WWY1井三叠系周冲村组首次发现了异常高压富氦天然气显示,对其中2个气样的气体组分分析发现,He的体积分数分别为4.51%和4.56%,远高于0.1%的氦气工业利用标准;³He/⁴He值分别为5.50×10^-8和6.40×10^-8,幔源氦占比仅仅为0.32%和0.40%,应属典型的壳源氦。同时依据δ¹³C_CH4、δ¹³C_CO2、CO₂含量及N₂含量综合分析认为该天然气为有机成因,其烃源岩类型与研究区广泛发育的二叠系烃源岩相吻合。通过区域地质资料和深部地球物理资料分析认为其氦源极可能来源于古—中元古代基底花岗岩。长江深断裂带可作为联通深部地壳与浅部地层的重要通道,对于氦气扩散外移起到了关键作用。当富氦流体运移至浅部遇到天然气等载体气气藏时,流体的氦浓度迅速降低,氦气大量脱溶进入载体气气藏形成富氦天然气藏,活动的断裂系统...     

Braking PSR J1734–3333 with a possible fall-back disk

The very small braking index of PSR J1734–3333,n=0.9±0.2,challenges the current theories of braking mechanisms in pulsars.We present a possible interpretation that this pulsar is surrounded by a fall-back disk and braked by it.A modified braking torque is proposed based on the competition between the magnetic energy density of the pulsar and the kinetic energy density of the fall-back disk.With this torque,a self-similar disk can fit all the observed parameters of PSR J1734–3333with natural initial values of parameters.In this regime,the star will evolve to the region having anomalous X-ray pulsars and soft gamma repeaters in the P˙P diagram in about 20 000 years and stay there for a very long time.The mass of the disk around PSR J1734–3333 in our model is about 10M⊕,similar to the observed mass of the disk around AXP 4U 0142+61.     

Interaction between adjacent lightning discharges in clouds

Using a 3D lightning radiation source locating system (LLS), three pairs of associated lightning discharges (two or more adjacent lightning discharges following an arbitrary rule that their space-gap was less than 10 km and their time-gap was less than 800 ms) were observed, and the interaction between associated lightning discharges was analyzed. All these three pairs of associated lightning discharges were found to involve three or more charge regions (the ground was considered as a special charge region). Moreover, at least one charge region involved two lightning discharges per pair of associated lightning discharges. Identified from electric field changes, the subsequent lightning discharges were suppressed by the prior lightning discharges. However, it is possible that the prior lightning discharge provided a remaining discharge channel to facilitate the subsequent lightning discharge. The third case provided evidence of this possibility. Together, the results suggested that, if the charges in the main negative charge region can be consumed using artificial lightning above the main negative charge regions, lightning accidents on the ground could be greatly reduced, on the condition that the height of the main negative charge region and the charge intensity of the lower positive charge region are suitable.     

物探技术在多年冻土探测方面的应用

在青藏高原东部温泉地区对多年冻土厚度探测进行了试验研究,总结出一套可行的用于探测0～100 m范围内多年冻土分布及厚度的探测方法:选用探地雷达及瞬变电磁测深法分别对冻土上限及冻土下限进行探测,探地雷达分辨率高,能够有效解决地下0～5 m范围内多年冻土是否存在及上限埋深情况,而瞬变电磁测深法能有效解决地下5～100 m范围内的多年冻土下限埋深情况。     

贵州盘县峨眉山玄武岩系顶部凝灰岩LA-ICP-MS 锆石U-Pb年龄:对峨眉山大火成岩省与生物大规模灭绝关系的约束

在20世纪90年代,有学者认为峨眉山大火成岩省(Emeishan Large Igneous Province, ELIP)大规模火山活动与二叠-三叠系之交(Permian-Triassic Boundary, P-TB)的生物大灭绝事件在时间上有耦合关系,随后的⁴⁰Ar/³⁹Ar同位素测年结果也显示峨眉山大火成岩省是晚二叠世形成的。但是,近些年大量的SHRIMP U-Pb测年结果表明,ELIP大规模火山喷发约在~260Ma;因此有研究认为,ELIP火山活动与中二叠世瓜德卢普期末(end-Guadalupian)的生物灭绝事件在时间上联系更加紧密。至于P-T界线生物大灭绝,现在多数学者认为是,由于西伯利亚大火成岩省火山强烈活动释放大量气体和火山灰所造成环境变化引起的。最近,我们在ELIP东部的贵州盘县峨眉山玄武岩系剖面中发现顶部发育厚度达近百米的凝灰岩层,其LA-ICP-MS U-Pb法测年结果为251.0±1.0Ma,与浙江煤山剖面中二叠系-三叠系边界处黏土层或火山灰层的锆石U-Pb年龄接近。因此,峨眉山玄武岩喷发结束的时间应该在P-T边界,与西伯利亚大火成岩省的主体喷发时间一致。新的测年结果暗示了ELIP火山活动与地球历史上最大的一次生物灭绝事件(P-T边界)可能存在着成因联系。     

基于GIS煤炭勘查地测空间信息系统

为改变地测行业生产与管理模式,提高信息化程度,基于组件GIS开发了煤炭勘察地测空间信息系统。该系统采用了.net2003 C#语言,其良好的开发界面和方便快捷的开发模式,保证了系统开发的简易性,节约了时间成本,且在功能设计上立足煤炭、地勘行业特点和实际情况。系统不仅适用于地勘、地测部门,也可以广泛应用于采矿等相关技术部门,是一种通用的数据库及图形处理专业化软件。应用实例表明该系统具有实用、专业、高效、易操作、动态预测可视化等特点。