2023年4月6日 Uranium and thorium are actinoids, a group of chemical elements with atomic numbers ranging from 89 (actinium) to 103 (lawrencium), including well-known
2021年1月15日 Using high-precision uranium-thorium (U Th) dating, we reconstruct a ~100-year-long history of extensive coral loss, changes in coral community structure, and
Tianran Chen, Shu Li, Jianxin Zhao, Yuexing Feng2023年11月1日 This paper looks at the present status of thorium nuclear fuel technology, providing an overview of thorium as a prospective natural resource for future energy, the
标记:ThoriumNuclear EnergyAbstract. The natural radioactive elements uranium (U) and thorium (Th) in atmospheric environment should be given attention, and their particle size distribution and
标记:ThoriumUraniumPublish Year:2019Abstract. Data from a wide variety of igneous rock types show that the ratio of potassium to uranium is approximately 1 × 10 4. This suggests that the value of K/U ≈ 1 × 10 4 is
标记:ThoriumUraniumPublish Year:19642020年6月1日 Uranium and thorium are the only naturally-occurring actinides in the Periodic Table of the Elements, and share many similar properties such as: the order of
标记:Nuclear EnergyNuclear PhysicsSeawater Abundance Of Thorium2012年1月1日 Uranium and thorium represent two elements which can be used for the production of energy. The types of uranium deposits, the mechanisms driving their
标记:ThoriumUraniumAuthor:Michel CuneyPublish Year:2012Abstract. On exposure of thorium to slow neutrons a small amount of uranium is formed in the irradiated material. From the irradiation product an aqueous solution is prepared of thorium and uranium nitrates the proportion of nitrate: water ranging from 0.7: 1 to 1.4: 1 and the proportion of uranium: thorium not exceeding 1: 50.
2020年4月28日 Abstract. We report the structural properties of ultra-small ThO 2 and UO 2 nanoparticles (NPs), which were synthesized without strong binding surface ligands by employing a covalent organic
2021年1月15日 Using high-precision uranium-thorium (U Th) dating, we reconstruct a ~100-year-long history of extensive coral loss, changes in coral community structure, and a shifting baseline. The data were collected at Weizhou Island, northern South China Sea (SCS), which has highly disturbed inshore coral habitats that are typical globally.
Abstract. Data from a wide variety of igneous rock types show that the ratio of potassium to uranium is approximately 1 × 10 4. This suggests that the value of K/U ≈ 1 × 10 4 is characteristic of terrestrial materials and is distinct from the value of 8 × 10 4 found in chondrites. In a model earth with K/U ≈ 10 4, uranium and thorium are ...
2017年3月6日 Abstract. The uranium-thorium (U-Th) method can constrain the age of cave art by providing dates of formation of calcite deposits from on top of paintings or calcite layers on which paintings were done. It is particularly useful for art made without radiocarbon datable organic pigments or binders, or where contamination of radiocarbon samples ...
2011年1月1日 Magmatic Enrichment of Uranium, Thorium, and Rare Earth Elements in Late Paleozoic Rhyolites of Southern New Brunswick, Canada: Evidence from Silicate Melt Inclusions Taryn R. Gray; ... Abstract. The major and trace element geochemistry of silicate melt inclusions was investigated within late Paleozoic felsic rhyolites from the Piskahegan
Abstract. Uranium, thorium and their decay products are the most common radionuclides in groundwater in addition to potassium-40. Once groundwater is used for drinking, domestic and irrigation purposes, the radionuclides will then pose environmental and health related hazard originating from radioactivity and toxicity. In the investigation ...
2008年11月1日 Abstract. Laser-induced breakdown spectrometry (LIBS) has been successfully developed to quantify thorium (Th) and uranium (U) in solution using membrane-based filter paper as a sample support. The filter paper is easy to handle and the entire analysis process takes only a few minutes for each sample. The developed method
2023年4月6日 Uranium and thorium are heavy metals, and all of their isotopes are radioactive, so it is impossible to study chemical effects entirely independent of the radiation effects. In the present study, we tried to compare the chemo- and radiotoxicity of both metals, taking into account deterministic radiation damages reflected by acute radiation
2021年1月15日 Using high-precision uranium-thorium (U Th) dating, we reconstruct a ~100-year-long history of extensive coral loss, changes in coral community structure, and a shifting baseline. The data were collected at Weizhou Island, northern South China Sea (SCS), which has highly disturbed inshore coral habitats that are typical globally.
2020年5月1日 Abstract. Uranium, thorium and potassium are distinguished in different compartments of the environmental media according to the inputs, the fate and the distribution patterns that occur in the ecosystems. Thus, an understanding of the sources patterns and behaviours of these elements in soils, their rock-soil relationships and
2020年8月1日 The felsic rocks are noted with frequent occurrences of thorium, mon- azite, and allanite, known as source of thorium, uranium, and REEs. Monazite occurring in such dacites is a major source of ...
Abstract. All isotopes heavier than 208 Pb (lead) are radioactive and many of these have half-lives that are long compared to the age of our Solar System. ‘Uranium, thorium, and their daughters’ describes the natural decay series where radioactive isotopes of uranium and thorium decay by α- and β-emission through several stages until a stable lead
The rate of ejection of alpha-recoil thorium-234 into solution from the surface of zircon sand gives an alpha-recoil range of 550 angstroms. The alpha-recoil thorium-234 atoms ejected into the groundwater may supply excess uranium-234.
2020年5月1日 Abstract. Uranium, thorium and potassium are distinguished in different compartments of the environmental media according to the inputs, the fate and the distribution patterns that occur in the ecosystems. Thus, an understanding of the sources patterns and behaviours of these elements in soils, their rock-soil relationships and
2020年8月1日 The felsic rocks are noted with frequent occurrences of thorium, mon- azite, and allanite, known as source of thorium, uranium, and REEs. Monazite occurring in such dacites is a major source of ...
Abstract. All isotopes heavier than 208 Pb (lead) are radioactive and many of these have half-lives that are long compared to the age of our Solar System. ‘Uranium, thorium, and their daughters’ describes the natural decay series where radioactive isotopes of uranium and thorium decay by α- and β-emission through several stages until a stable lead
The rate of ejection of alpha-recoil thorium-234 into solution from the surface of zircon sand gives an alpha-recoil range of 550 angstroms. The alpha-recoil thorium-234 atoms ejected into the groundwater may supply excess uranium-234.
Abstract. Work on various methods of assay of uranium and thorium in ores by purely radiometric methods are described. Some of the methods are applicable only to ores containing either uranium or thorium separately, and some can be used when a mixture of the two is present in one ore. Methods are discussed also of dealing with ores in which
Uranium and thorium are two common natural radioactive elements with high concentrations in Earth’s crust. The main aim of this study is to estimate the inhaled effective dose of uranium and thorium caused by a typical radioactive rare earth ore to the occupational population and the surrounding public. The particulate matter (PM)
1970年10月1日 A correlation between uranium concentrations and magnetic properties due to inclusions with high susceptibility has been observed by ABBHENIVS and KOBKISCH (1959). uranium, thorium, potassium and argon in marine phillipaites 1069 SUMMABY A model for the growth of phillipsite m the marine sedimentary column is
Abstract The solubility of uranium and thorium has been measured under the conditions anticipated in a cementitious, geological disposal facility for low and intermediate level radioactive waste. ... No breakthrough of either uranium or thorium was observed in diffusion experiments involving NRVB after three years. Nevertheless, backscattering ...
2019年5月31日 Abstract Activation of prototypical bonds by actinide atoms is an important aspect of material activity, and the results can be used for the study of nuclear material storage. In this study, the activation of the P–H bonds of the PH 3 molecule by U or Th to form uranium or thorium hydride phosphorus has been systematically explored using ...
2021年11月1日 Uranium is mostly present in accessory minerals (zircon, allanite and monazite) in granite and charnockite rock bodies (Park and Dash, 1984; Kamineni and Rao, 1988). Compared to thorium, uranium can be easily leached from the granite and charnockite rock bodies and transported to greater distances because of its high reactivity
2018年2月10日 Uranium and Thorium Uranium and Thorium. Roger James Kuhns 3 George H. Shaw 4 Chapter; First Online: 10 February 2018; 400 Accesses. Abstract. Nuclear energy relies on uranium resources, and the production of electricity from this fuel source is applicable to centralized power stations, military naval vessels, and to a lesser
2023年9月1日 Introduction. Uranium and thorium are naturally occurring, radioactive heavy metals with unusual properties. The energy generated by the natural breakdown of radioactive elements is immense and can be used in nuclear reactors. Australia has significant resources of both uranium and thorium within the rocks that make up the
Abstract. A direct method of uranium and thorium determination in non-conducting geological samples using time-of-flight mass spectrometry with pulsed glow discharge was proposed. The following rock specimens were analysed: metamict zircon, metamict rinkite, metamict samarskite (Y–Fe-niobate), pyrochlore and jacinth.
Abstract. The thorium and uranium contents of the volcanic and ancient terra formations of Mars are evaluated on the basis of Mars-5 space probe measurements of gamma radiation from the Martian surface. Gamma-ray data for two partially overlapping territories containing different proportions of the major Martian geological formations were ...