A study of the glazing techniques and provenances of Tang sancai glazes using elemental and lead isotope analyses

This study discusses the elemental compositions and lead isotope ratios of Tang sancai glazes unearthed from the Huangpu kiln, Huangye kiln and two Tang sancai tomb sites. The various glazes feature distinct lead isotope ratios and trace element characteristics, which can be interpreted as evidence for the use of different lead ore deposits and siliceous raw materials in the glazes. This is a strong indication that lead isotopes combined with trace element analysis could be used as a viable approach for identifying the provenance of Tang sancai of unknown origin by linking them to kiln sites, This provenance technique could be significant in the interpretation of ancient ceramic trade and communication patterns. In this study, the provenance of several Tang sancai glazes of uncertain origin were determined using this method: some Tang sancai wares unearthed in Xi'an City were produced in the kiln near Luoyang City and then traded to Xi'an City, providing an idea of ancient Tang sancai ceramic trade route

Iron isotope compositions of coexisting sulfide and silicate minerals in Sudbury-type ores from the Jinchuan Ni-Cu- sulfide deposit: A perspective on possible core-mantle iron isotope fractionation

Many studies have shown that the average iron (Fe) isotope compositions of mantle-derived rocks, mantle peridotite and model mantle are close to those of chondrites. Therefore, it is considered that chondrite values represent the bulk Earth Fe isotope composition. However, this is a brave assumption because nearly 90% Fe of the earth is in the core, whose Fe isotope composition is unknown, but is required to construct bulk earth Fe isotope composition. We approach the problem by assuming that the earth’s core separation can be approximated in terms of the Sudbury-type Ni-Cu sulfide mineralization, where sulfide-saturated mafic magmas segregate into immiscible sulfide liquid and silicate liquid. Their density/buoyancy controlled stratification and solidification produced net-textured ores above massive ores and below disseminated ores. The coexisting sulfide minerals (pyrrhotite (Po) > pentlandite (Pn) > chalcopyrite (Cp)) and silicate minerals (olivine (Ol) > orthopyroxene (Opx) > clinopyroxene (Cpx)) are expected to hold messages on Fe isotope fractionation between the two liquids before their solidification. We studied the net-textured ores of the Sudbury-type Jinchuan Ni-Cu sulfide deposit. The sulfide minerals show varying δ56Fe values (-1.37 ~ -0.74‰ (Po) < 0.09 ~ 0.56‰ (Cp) < 0.53 ~ 1.05‰ (Pn), but silicate minerals (Ol, Opx, Cpx) have δ56Fe values close to chondrites (δ56Fe = -0.01±0.01‰). The heavy δ56Fe value (0.52 ~ 0.60‰) of serpentines may reflect Fe isotopes exchange with the coexisting pyrrhotite with light δ56Fe. We ob- tained an equilibrium fractionation factor of Δ56Fesilicate-sulfide = ~ 0.51‰ between reconstructed silicate liquid (δ56Fe = ~ 0.21‰) and sulfide liquid (δ56Fe = ~ -0.30‰), or Δ56Fesilicate-sulfide = ~ 0.36‰ between the weighted mean bulk-silicate minerals (δ56Fe[0.70ol,0.25opx,0.05cpx] = 0.06‰) with weighted mean bulk- sulfide minerals (δ56Fe = ~ -0.30‰). Our study indicates that significant Fe isotope fractionation does take place between silicate and sulfide liquids during the Sudbury-type sulfide mineralization. We hypothesize that significant iron isotope fractionation must have taken place during core-mantle segregation, and the bulk earth may have lighter Fe isotope composition than chondrites although Fe isotope analysis on experimental sulfide-silicate liquids produced under the varying mantle depth conditions is needed to test our results. We advocate the importance of further research on the subject. Given the close Fe-Ni association in the magmatic mineralization and the majority of Earth’s Ni is also in the core, we infer that Ni isotope fractionation must also have taken place during the core separation that needs attention

Astronomical Distance Determination in the Space Age: Secondary Distance Indicators

The formal division of the distance indicators into primary and secondary leads to difficulties in description of methods which can actually be used in two ways: with, and without the support of the other methods for scaling. Thus instead of concentrating on the scaling requirement we concentrate on all methods of distance determination to extragalactic sources which are designated, at least formally, to use for individual sources. Among those, the Supernovae Ia is clearly the leader due to its enormous success in determination of the expansion rate of the Universe. However, new methods are rapidly developing, and there is also a progress in more traditional methods. We give a general overview of the methods but we mostly concentrate on the most recent developments in each field, and future expectations. © 2018, The Author(s)

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)

[no abstract available

GW190814: gravitational waves from the coalescence of a 23 solar mass black hole with a 2.6 solar mass compact object

We report the observation of a compact binary coalescence involving a 22.2–24.3 Me black hole and a compact object with a mass of 2.50–2.67 Me (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO’s and Virgo’s third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of - + 241 45 41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with gravitational waves, - + 0.112 0.009 0.008, and its secondary component is either the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system. The dimensionless spin of the primary black hole is tightly constrained to �0.07. Tests of general relativity reveal no measurable deviations from the theory, and its prediction of higher-multipole emission is confirmed at high confidence. We estimate a merger rate density of 1–23 Gpc−3 yr−1 for the new class of binary coalescence sources that GW190814 represents. Astrophysical models predict that binaries with mass ratios similar to this event can form through several channels, but are unlikely to have formed in globular clusters. However, the combination of mass ratio, component masses, and the inferred merger rate for this event challenges all current models of the formation and mass distribution of compact-object binaries

Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

Production of Υ(nS) mesons in Pb+Pb and pp collisions at 5.02 TeV

A measurement of the production of vector bottomonium states, Υ ( 1S ) , Υ ( 2S ) , and Υ ( 3S ) , in Pb + Pb and p p collisions at a center-of-mass energy per nucleon pair of 5.02 TeV is presented. The data correspond to integrated luminosities of 1.38 nb − 1 of Pb + Pb data collected in 2018, 0.44 nb − 1 of Pb + Pb data collected in 2015, and 0.26 fb − 1 of p p data collected in 2017 by the ATLAS detector at the Large Hadron Collider. The measurements are performed in the dimuon decay channel for transverse momentum p μ μ T &lt; 30 GeV , absolute rapidity | y μ μ | &lt; 1.5 , and Pb + Pb event centrality 0–80%. The production rates of the three bottomonium states in Pb + Pb collisions are compared with those in p p collisions to extract the nuclear modification factors as functions of event centrality, p μ μ T , and | y μ μ | . In addition, the suppression of the excited states relative to the ground state is studied. The results are compared with theoretical model calculations

Lu Ji’s Structural Imitation Method and His Influence on Poets of the Southern Dynasties

本文試圖從「影響」的角度，考察陸機詩歌在南朝奠定「經典」地位的原因。陸機擬作古詩時，跟隨前作結構，置換文辭的「擬篇法」，為謝靈運、謝惠連、沈約等南朝詩人所繼承，而且模擬的多為陸機詩作。在各種擬作形式中，「擬篇法」最清楚標誌後輩詩人與經典前作的關連，故本文分析南朝詩人擬篇陸機之作，探討陸機對於南朝詩人的影響。首先，陸機詩歌以辭賦化的結構鋪寫時間物象，完成「嘆逝」主題的新風貌；注重結構層次的描寫方式，成為南朝詩人模仿的重點。其次，陸機的影響不僅在於形式典範，更來自情感上的召喚——作為一位士人，在出處進退之間的矛盾與感嘆。南朝詩人們藉著擬篇，表達對陸機的呼應、認同與對話，進而使陸機徘徊仕隱的形象，成為一種士人困境的原型。此外，陸機與陸雲以詩歌贈答，互相慰勉，或以擬作樂府舊題的方式，將前作內容納入，形成多重互文的對話。謝靈運與謝惠連亦模仿此方式，在共同擬篇陸機詩作中進行贈答對話；不僅再現二陸兄弟的互文，陸機的生命困境與仕途感嘆，更成為二謝對話中的潛在聲音。陸機詩歌之所以被南朝詩人奉為經典，實具有上述各方面的原因與意義，而應在文學史上有更公允的評價與定位。This paper explores how Lu Ji’s influence on later poets makes his poetry regarded as classic in the Southern Dynasties. Lu always composes his imitations of ancient poems by meticulously maintaining the structure of the originals and exchanging their words. Southern Dynasties poets such as Xie Ling-Yun, Xie Hui-Lian and Shen Yue keep using this structural imitation method to compose imitations, primarily of Lu’s works. Of all methods of imitation writing, structural imitation is the one that most clearly indicates connection between the original poem and the imitator. For this reason, this paper inspects Southern Dynasties poets’ imitations of Lu’s works to discuss Lu’s influence on them. First, Lu’s poetry describes time and things with structure made of fu poetry’s quality, creating a new appearance for the topic of lamenting the past. This structural feature is the point of Southern Dynasties poets’ imitation. Second, Lu influences not only the form of poetry but its emotions, displaying the scholar-official poet’s inner conflict and sentiment about whether to be an official or a recluse. Southern Dynasties poets use the method to respond to and identify with Lu, transforming Lu’s hesitant image into a prototype of scholar-official in dilemma. In addition, Xie Ling-Yun and Xie Hui-Lian use this method to follow Lu Ji and Lu Yun’s example of presenting each other with poems as the method of dialogue, in which Lu’s dilemma and grief over his career become the inner voice of the two Xies’ poems. The above are the reasons and significances of the canonization of Lu’s poetry during the Southern Dynasties, which are to provide Lu with a more adequate evaluation and position in the history of literature