Fe-rich carbonatites with a mineral assemblage of ankerite-calcite or siderite are widespread in southern Siberia, Russia. The siderite carbonatites are associated with F-Ba-Sr-REE mineralization and ...have a
40
Ar/
39
Ar age of 117.2 ± 1.3 Ma. Melt and fluid inclusions suggest that the carbonatites formed from volatile-rich alkali- and chloride-bearing carbonate melts. Ankerite-calcite carbonatites formed from carbonatite melt at a temperature of more than 790 °C. The ferrocarbonatites (the second phase of carbonatite intrusion) formed from a sulfate-carbonate-chloride fluid phase (brine-melt) at >650 °C and ≥360 MPa. The brine-melt fluid phase had high concentrations of Fe and LREEs. A subsequent hydrothermal overprint contributed to the formation of economically important barite-Sr-fluorite-REE mineralization in polymict siderite breccia.
Large areas of central Asia and mainland China have been affected by intraplate anorogenic magmatism, linked to mantle activity from the Palaeoproterozoic to present day. This magmatism is manifested ...by layered mafic–ultramafic intrusions, flood basalts, bimodal volcanic rocks, dyke swarms, I- and A-type granitoids, alkaline complexes, carbonatites and kimberlites. In this paper we discuss a selection of these thermal events, namely East Asia Mesozoic–Cenozoic, Siberian Traps, Emeishan, Tarim (Bachu), Yakutsk and South China. Mineral systems that are associated with the Asian intraplate magmatic events include Ni–Cu–PGE in mafic–ultramafic intrusions, porphyry Cu–Mo and skarn deposits, polymetallic veins and auriferous lode deposits generally hosted in granitoids, rare earths and rare metals in alkaline complexes and diamondiferous kimberlites. The anorogenic intraplate igneous rocks originate from mantle sources or mixed mantle and crustal sources and are related, directly or indirectly, to deep mantle plumes or to asthenospheric upwellings that occur in response to lower crust and subcontinental lithosphere delamination linked to collision and subduction processes.
The use of multilevel quantum information carriers, also known as qudits, has attracted significant interest as a way of further scaling quantum computing devices. However, such multilevel systems ...usually express shorter coherence time than their two-level counterparts, which limits their computational potential. We thus propose and experimentally demonstrate two approaches for realizing the continuous dynamical decoupling of magnetic-sensitive states with
m
F
= ±1 for qudits encoded in optical transition of trapped
171
Yb
+
ions. We improve the coherence time of qudit levels by an order of magnitude (more than 9 ms) without any magnetic shielding, revealing the potential advantage of the symmetry of the
171
Yb
+
ion energy structure for counteracting magnetic field noise. Our results are a step toward realizing qudit-based algorithms using trapped ions.
Hybrid magnetic heterostructures made of epitaxial manganite La
0.7
Sr
0.3
MnO
3
thin film and intermetallic superlattice (TeCo
2
/FeCo)
n
were prepared on orthorhombic NdGaO
3
substrates and ...characterized by means of magneto-optical Kerr effect and magnetoresistance. Experimental data show that magnetic interaction between La
0.7
Sr
0.3
MnO
3
and (TeCo
2
/FeCo)
n
is of the antiferromagnetic type. The features observed in magnetotransport characteristics are caused by the magnetization reversal at the interface between manganite thin film and intermetallic superlattice.
This paper presents new data derived from field sampling and from a thorough description of lamprophyres located in southeastern Altai and northwestern Mongolia in terms of their mineralogy, ...textures, and chemical composition. The swarms of alkaline mafic dikes in the area coexist with granosyenite-monzodiorite and gabbro-dolerite intrusions and spatially coincide with an ore district of Sb-Hg, Ag-Sb, Ni-Co-As, Cu-Mo-W, and CaF2 hydrothermal mineralization. All lamprophyres belong to the Early Mesozoic Chuya complex formed in an intracontinental enviroment. Their distribution and orientation is controlled by two large fault zones. The Chuya dikes were investigated at two localities, namely, Yustyd and South-Chuya. The Yustyd lamprophyres intrude Middle-Upper Devonian black shale of the Yustyd depression. At South Chuya, lamprophyres, together with the Tarkhata granosyenite-monzodiorite complex, are hosted by Cambrian and Ordovician metamorphic rocks of the South-Chuya Range. Ar-Ar (phlogopite) and U-Pb (SHRIMP, zircon) ages of the lamprophyre dikes indicate long and continuous period of the formation of the Chuya complex (250-235 Ma). Major- and trace-element compositions of the lamprophyres from both localities and of the syenite indicate their origin from the same magma source. The textures and structures of the lamprophyre and plutonic rocks, their mineral assemblages and the chemistry of the rock-forming minerals provide clues to the evolution of the parental alkaline mafic magma and fluid regime.
The review article discusses modern methods for diagnosing and treating patients with non-muscle-invasive bladder cancer. The search and analysis of information was carried out in the databases ...PubMed, Google Scholar, eLibrary. Information about photodynamic diagnostics, narrow-band imaging, mono- and bipolar transurethral resection, transurethral thulium and holmium laser resection, en-bloc resection of neoplasms, Nd:YAG laser ablation of the tumor bed is presented. The features, advantages and disadvantages of each of these methods, as well as their combinations and modifications are described in detail. Particular attention is paid to the use of laser technologies in the surgical treatment of patients with non-muscle-invasive bladder cancer. An analysis of the results of studies of the efficacy and safety of various methods of surgical treatment of non-muscle-invasive bladder cancer was carried out. The significance of the problem of increasing the efficiency of treatment of such patients, which is one of the priority areas of modern oncourology, is indicated.
Economic Ag–Sb deposits are located within four large ore districts of Central Asia: SE Altai–NW Mongolia, SE Pamir (Tajikistan), Talas (Kyrgyzstan) and Verkhoyansk province (Yakutia), where Ag–Sb ...ores are spatially associated with tin mineralization. The geology, mineral composition and geochemistry of the Ag–Sb deposits, age of mineralization, distribution and genesis are presented in this paper. Results of new studies show that Ag–Sb ores commonly occur within Sn ore provinces and can be divided into three groups according to their relationships with tin mineralization. Ag–Sb deposits of the first group are spatially isolated from Sn–W ore fields and from metamorphic haloes of Sn-bearing granitoids (pre-granitic deposits of the Mangazeisky ore cluster in Yakutia and deposits of the Asgat-Ozernoe ore zone in the SE Altai–NW Mongolia). A 240
±
3.5 Ma
39Ar/
40Ar age of Ag–Sb mineralization was determined for the Asgat deposit (SE Altai–NW Mongolia), which correlates well with the 243
±
3.7 Ma
39Ar/
40Ar age of alkaline mafic intrusions (lamprophyre dike). The Ag–Sb ore appears to be younger than Sn–W mineralization (352
±
6.0 Ma) related with granite of the Yustid complex (355.7
±
8.6 Ma). The second group comprises granite-hosted Ag–Sb deposits of the Bazardara ore cluster (SE Pamir) of Paleogene age (44
±
1.5 Ma) located within a tin ore cluster, but separated in time from the Cretaceous Sn mineralization (98.5
±
1 Ma, Ar–Ar). Ag–Sb ore veins of the third group are located within tin ore clusters and are nearly coeval with tin mineralization (post-granitic Ag rich ore of the Mangazeiskoe, Prognoz and Menkechenskoe deposits, Verkhoyansk province). A close spatial and temporal relationship of Ag–Sb deposits with Sb–Hg mineralization and alkaline mafic magmatism is observed. Helium isotope systematics from the ore-forming fluids of Ag–Sb Akjilga deposit (Pamir) confirm the role of mantle helium in the ore-forming process. Another important indicator of a mantle source in these Ag–Sb deposits is the Hg content in the ores; Hg being a typical element of mantle origin. Isotopic (
3He/
4He,
87Sr/
86Sr, Pb, S) and geochronological data demonstrate that Ag–Sb deposits are polygenetic in sources of ore matter and relate to the mantle-crustal ore-magmatic systems.