Monopole gravitational waves from relativistic fireballs driving gamma-ray bursts

Einstein's general relativity predicts that pressure, in general stresses, plays a similar role to energy density,  ε=ρ c ²  (with ρ being the corresponding mass density), in generating gravity. The source of gravitational field, the active gravitational mass density, sometimes referred to as Whittaker's mass density, is  ρ_grav=ρ+ 3 p / c ²  , where p is pressure in the case of an ideal fluid. Whittaker's mass is not conserved, hence its changes can propagate as monopole gravitational waves. Such waves can be generated only by astrophysical sources with varying gravitational mass. Here we show that relativistic fireballs, considered in modelling gamma-ray burst phenomena, are likely to radiate monopole gravitational waves from high-pressure plasma with varying Whittaker's mass. Also, ejection of a significant amount of initial mass-energy of the progenitor contributes to the monopole gravitational radiation. We identify monopole waves with   h ¹¹+ h ²²  waves of Eddington's classification which propagate (in the z -direction) together with the energy carried by massless fields. We show that the monopole waves satisfy Einstein's equations, with a common stress-energy tensor for massless fields. The polarization mode of monopole waves is  Φ₂₂  , i.e. these are perpendicular waves which induce changes of the radius of a circle of test particles only (breathing mode). The astrophysical importance of monopole gravitational waves is discussed.     

High‐Precision Measurement of Molybdenum Isotopic Compositions of Selected Geochemical Reference Materials

Here we describe high‐precision molybdenum isotopic composition measurements of geological reference materials, performed using multi‐collector inductively coupled plasma‐mass spectrometry (MC‐ICP‐MS). Purification of Mo for isotopic measurements was achieved by ion exchange chromatography using Bio‐Rad AG^® 1‐X8 anion exchange resin. Instrumental mass bias was corrected using ¹⁰⁰Mo‐⁹⁷Mo double spiking techniques. The precision under intermediate measurement conditions (eighteen measurement sessions over 20 months) in terms of δ^98/95Mo was 0.10‰ (2s). The measurement output was approximately four times more efficient than previous techniques, with no compromise in precision. The Mo isotopic compositions of seven geochemical reference materials, seawater (IAPSO), manganese nodules (NOD‐P‐1 and NOD‐A‐1), copper‐molybdenum ore (HV‐2), basalt (BCR‐2) and shale (SGR‐1b and SCo‐1), were measured. δ^98/95Mo values were obtained for IAPSO (2.25 ± 0.09‰), NOD‐P‐1 (?0.66 ± 0.05‰), NOD‐A‐1 (?0.48 ± 0.05‰), HV‐2 (?0.23 ± 0.10‰), BCR‐2 (0.21 ± 0.07‰), SCo‐1 (?0.24 ± 0.06‰) and SGR‐1b (0.63 ± 0.02‰) by calculating δ^98/95Mo relative to NIST SRM 3134 (0.25‰, 2s). The molybdenum isotopic compositions of IAPSO, NOD‐A‐1 and NOD‐P‐1 obtained in this study are within error of the compositions reported previously. Molybdenum isotopic compositions for BCR‐2, SCo‐1 and SGR‐1b are reported for the first time.     

An Investigation of the Reliability of HF Acid Mixtures in the Bomb Digestion of Silicate Rocks for the Determination of Trace Elements by ICP‐MS

The influence of the mixtures HF‐HNO₃ and HF‐NH₄F‐HNO₃ in bomb digestion for trace element determination from different rock types was studied using ICP‐MS. It is shown that the HF concentration, not the ratio of reagents in the decomposing mixture, controls the digestion process of a rock. Data for Zr in the granite G‐2 as a function of HF concentration gave the same results as reaction mixtures of various compositions. A complete digestion in 50‐mg sample bombs was achieved by 1.0 ml of HF alone, or with a mixture of other acids at a HF concentration of at least 35% m/m at 196 °C over 18 h. The results of the analysis of basalts BCR‐1, BIR‐1, mica schist SDC‐1, shale SBC‐1, granites G‐2, SG‐1A, garnet‐biotite plagiogneiss GBPg‐1, rhyolite RGM‐1, granodiorite GSP‐1, trachyandesite MTA‐1 and rhyolite MRh‐1 are given and compared against available data. The reproducibility of the element determinations by ICP‐MS and XRF as an independent non‐destructive analysis for a quality check in the range of concentrations typical for routine rock samples is given.     

辽东青城子矿集区姚家沟钼矿床成矿物质来源、成矿年代及成矿动力学背景

本文对辽东青城子矿集区姚家沟钼矿床与成矿密切的姚家沟花岗岩进行了元素地球化学、锆石LA-ICP-MS U-Pb定年和矿床金属硫化物硫同位素系统分析。结果表明:姚家沟花岗岩侵入时代为(167.47±0.87)Ma,具有富硅、富铝、全碱含量中等、过铝质-强过铝质的特征;稀土配分模式呈现轻稀土富集、重稀土亏损的右倾型,Eu弱正异常;富集K、Rb、U、Sr、Pb等大离子亲石元素,亏损Nb、Ti、P等高场强元素,δ34S值为2.0‰~3.9‰,平均值为2.7‰。结合姚家沟矿床辉钼矿Re-Os同位素研究成果进一步得出,姚家沟岩体至少为两期岩浆活动的产物,辉钼矿成矿与本次获得的(167.47±0.87)Ma岩浆活动有关,二者成岩、成矿时代一致。硫同位素指示成矿物质来源于岩浆。姚家沟钼矿成岩、成矿构造背景为受古亚洲洋闭合影响,华北板块与西伯利亚板块后碰撞造山阶段构造-岩浆-流体活动的环境。     

土壤中痕量氨基甲酸酯和三唑类农药的样品提取方法研究

本文对比研究了QuEChERS、加速溶剂萃取和超声提取三种方法,结合液相色谱-串联质谱法解决了土壤中18种极性强、热稳定性差的痕量氨基甲酸酯和三唑类农药提取难题。研究表明,Qu ECh ERS法的基体加标回收率为76.3%~121.0%(除涕灭威为27.5%外),超声提取法为71.0%~100.0%(除涕灭威为4.7%,涕灭威亚砜为137.8%外),加速溶剂萃取法大多低于70%(甲硫威、涕灭威、三唑醇几乎没有回收),可见QuEChERS法比另两种提取方法结果更优,最终确定为检测氨基甲酸酯类和三唑类农药的样品提取方法。涕灭威回收率偏低、涕灭威亚砜回收率偏高与提取方法的热效应有关;仲丁威、甲萘威等组分的回收状况与土壤类型相关。     

2020年3月20日蒙古MS 5.9地震前地倾斜资料异常特征分析

采用形态法和小波分析法,分析2020年3月20日蒙古M_S 5.9地震震中距400 km范围内巴里坤、富蕴和芨芨台地震台倾斜观测资料的震前异常特征。结果表明：3套资料在震前均具有明显的中短期异常,分别表现为反向趋势变化、破年变形态和倾斜速率减缓的特征;使用db4小波对3套资料进行分析,其6—9阶在震前出现周期为几天至几十天的低频短期异常,同时巴里坤水平摆倾斜仪EW分量8—9阶趋势异常较显著。     

2022年1月2日宁蒗MS 5.5地震现场新闻宣传启示

2022年1月2日云南省丽江市宁蒗县发生M_S 5.5地震。震后社会舆论关注度较高,相关话题一度冲上新浪微博热搜榜第十位。此时,因地震系统职责所在,运用新闻宣传手段快速、高效回复社会关切,既可还原地震事件真相、有效减少地震谣言的产生,亦能塑造地震行业的正面形象,从而更好地为防震减灾事业发展服务。     

2022年6月1日芦山MS 6.1地震前地电阻率异常分析

利用归一化速率变化方法（NVRM）分析处理了芦山M_S 6.1地震震中距450 km范围内的成都地震基准台、冕宁地震台、红格地震台、甘孜地震台等4个台站的地电阻率观测数据,结果显示：红格地震台NS、EW测道及甘孜地震台NE测道原始数据震前出现年变趋势性下降,下降幅度为1%—3%;红格地震台NVRM曲线震前出现正异常,冕宁地震台、甘孜地震台出现负异常,曲线转折下降过程中发生芦山M_S 6.1地震。虽然整体而言提取出的地电阻率震前异常在时间上与此次地震对应关系较好,但甘孜地震台、红格地震台与此次地震震中间距离均大于300 km,提取出的异常是否为此次地震异常,还需进一步探究。     

A Study on the Mineralization of the Woxi Au–Sb–W Deposit,Western Hunan,China

The Woxi Au–Sb–W deposit in the western Hunan Province, China, is of hydrothermal vein type characterized by a rare mineral assemblage of stibnite, scheelite and native gold, of which gold fineness ranges from 998.6 to 1000. The mineralization sequence observed in the deposit is, from early to late, coarse‐grained pyrite – scheelite – stibnite – Pb–Sb–S minerals – sphalerite (+ cubanite) – fine‐grained pyrite. Native gold may have precipitated with scheelte. Microthermometric and LA–ICP–MS analyses of fluid inclusions in scheelite, quartz associated with scheelite and stibnite and barren quartz clarified that there may be at least three types of hydrothermal fluids during the vein formation in the Woxi deposit. Scheelite and native gold precipitated from the fluid of high temperature and salinity with high concentrations of metal elements, followed by stibnite precipitation. The later fluid of the highest temperature and salinity with low concentrations of the elements yielded the sphalerite mineralization. The latest fluid of low temperature and salinity with low concentrations of the elements is observed mainly in barren quartz. The remarkably high Au/Ag concentration ratios determined in the fluid inclusions in scheelite might be the reason for the extremely high gold fineness of native gold.     

A Rapid Method for Determining Boron Concentration (ID‐ICP‐MS) and δ11B (MC‐ICP‐MS) in Vegetation Samples after Microwave Digestion and Cation Exchange Chemical Purification

We present in this article a rapid method for B extraction, purification and accurate B concentration and δ¹¹B measurements by ID‐ICP‐MS and MC‐ICP‐MS, respectively, in different vegetation samples (bark, wood and tree leaves). We developed a rapid three‐step procedure including (1) microwave digestion, (2) cation exchange chromatography and (3) microsublimation. The entire procedure can be performed in a single working day and has shown to allow full B recovery yield and a measurement repeatability as low as 0.36‰ (± 2s) for isotope ratios. Uncertainties mostly originate from the cation exchange step but are independent of the nature of the vegetation sample. For δ¹¹B determination by MC‐ICP‐MS, the effect of chemical impurities in the loading sample solution has shown to be critical if the dissolved load exceeds 5 μg g^?1 of total salts or 25 μg g^?1 of DOC. Our results also demonstrate that the acid concentration in the sample loading solution can also induce critical isotopic bias by MC‐ICP‐MS if chemistry of the rinsing‐, bracketing calibrator‐ and sample solutions is not thoroughly adjusted. We applied this method to provide a series of δ¹¹B values of vegetal reference materials (NIST SRM 1570a = 25.74 ± 0.21‰; NIST 1547 = 40.12 ± 0.21‰; B2273 = 4.56 ± 0.15‰; BCR 060 = ?8.72 ± 0.16‰; NCS DC73349 = 16.43 ± 0.12‰).