Search Results (1,878)

The Lujiang–Chuzhou Metallogenic Area is an important component of the Middle–Lower Yangtze River Valley Metallogenic Belt. Despite being an important copper–gold deposit in this area, the Shanlixu skarn Cu-Au deposit has not yet been systematically studied. According to LA-ICP-MS zircon U-Pb dating, the quartz monzonite porphyry from the Shanlixu deposit is aged 137.5 ± 1.7 Ma: while it differs from the timing of the magmatism and related mineralization in the Lujiang–Chuzhou Area, it is consistent with magmatic activity elsewhere in the Middle–Lower Yangtze River Valley Metallogenic Belt. The Ce⁴⁺/Ce³⁺ values of zircon in the quartz monzonite porphyry vary from 204.5 to 886.5, indicating that the intrusion might have formed in an environment with high oxygen fugacity. Additionally, the quartz monzonite porphyry exhibits high contents of Al₂O₃, Sr, Ba, and Mg^# (Mg^# = Mg²⁺/(Mg²⁺ + Fe²⁺)) and low ratios of Y, Nb, Ta, and K₂O/Na₂O, showing geochemical characteristics similar to those of adakitic rocks. Based on these characteristics, it is suggested that the intrusion might have been derived from the partial melting of subducted oceanic crust under a continental arc margin setting. Furthermore, it is strongly indicated that the quartz monzonite porphyry from the Shanlixu deposit, in the Lujiang–Chuzhou Area, is closely related to Cu-Au mineralization, as suggested by the age of the intrusion, which is approximately 137 Ma. These findings provide a new direction for research and exploration in this region. Full article

Due to the optical properties of the electron transport layer (ETL) and hole transport layer (HTL), inverted perovskite solar cells can perform better than traditional perovskite solar cells. It is essential to compare both types to understand their efficiencies. In this article, we studied inverted perovskite solar cells with NiO_x/CH₃NH₃Pb₃/ETL (ETL = MoO₃, TiO₂, ZnO) structures. Our results showed that the optimal thickness of NiO_x is 80 nm for all structures. The optimal perovskite thickness is 600 nm for solar cells with ZnO and MoO₃, and 800 nm for those with TiO₂. For the ETLs, the best thicknesses are 100 nm for ZnO, 80 nm for MoO₃, and 60 nm for TiO₂. We found that the efficiencies of inverted perovskite solar cells with ZnO, MoO₃, and TiO₂ as ETLs, and with optimal layer thicknesses, are 30.16%, 18.69%, and 35.21%, respectively. These efficiencies are 1.5%, 5.7%, and 1.5% higher than those of traditional perovskite solar cells. Our study highlights the potential of optimizing layer thicknesses in inverted perovskite solar cells to achieve higher efficiencies than traditional structures. Full article

The present paper describes the technological solution for obtaining Cu, Zn, Pb, and Ag from jarosite waste raw material, with its simultaneous separation from In and Fe. By roasting at low temperatures, iron was transformed from the Fe₂(SO₄)₃ form into Fe₂O₃, which is insoluble in water and slightly soluble in acid. Copper sulfate and zinc sulfate are present in jarosite as sulfates. During temperature roasting, the copper and zinc were still in the form of CuSO₄ and ZnSO₄, i.e., they were easily dissolved in water. This procedure led to good selectivity of Cu and Zn compared to Fe. After water leaching, PbSO₄ and Ag₂SO₄ remained in the solid residue. By treating jarosite with a content of 0.7% Cu, 5.39% Zn, and 5.68% Pb, products of commercial quality were obtained. By roasting jarosite in an electric furnace and leaching the roasted sample in water, leaching degrees of 91.07%, 91.97%, and 9.60% were obtained for Cu, Zn, and Fe, respectively. Using 1 M NaOH in the leaching solution, 99.93% Fe was precipitated to pH = 4. Cu in the form of CuSO₄ was further treated by cementation with Zn, after which cement copper was obtained as a commercial product. Zn in the form of ZnSO₄ was further treated by precipitation with Na₂CO₃ to obtain ZnCO₃ concentrate of commercial grade. The total recovery of Pb and Ag, which were treated by chloride leaching, was 96.05% and 87.5%, respectively. The resulting NaPbCl₃ solution was further treated with Na₂CO₃ solution, whereby PbCO₃ was obtained as a commercial product. The produced PbCO₃ could be further subjected to roasting to obtain soluble PbO. In these investigations, PbCO₃ was smelted where a Pb anode was obtained; this was electrolytically refined to a Pb cathode. The proposed process does not pollute the environment with As and Cd. Full article

Fluid infiltration into Proterozoic and Early Palaeozoic dry, orthopyroxene-bearing granitoids and gneisses in Dronning Maud Land, Antarctica, has caused changes to rock appearance, mineralogy, and rock chemistry. The main mineralogical changes are the replacement of orthopyroxene by hornblende and biotite, ilmenite by titanite, and various changes in feldspar structure and composition. Geochemically, these processes resulted in general gains of Si, mostly of Al, and marginally of K and Na but losses of Fe, Mg, Ti, Ca, and P. The isotopic oxygen composition (δ¹⁸O_SMOW = 6.0‰–9.9‰) is in accordance with that of the magmatic precursor, both for the host rock and infiltrating fluid. U-Pb isotopes in zircon of the altered and unaltered syenite to quartz-monzonite indicate a primary crystallization age of 520.2 ± 1.0 Ma, while titanite defines alteration at 485.5 ± 1.4 Ma. Two sets of gneiss samples yield a Rb-Sr age of 517 ± 6 Ma and a Sm-Nd age of 536 ± 23 Ma. The initial Sr and Nd isotopic ratios suggest derivation of the gneisses from a relatively juvenile source but with a very strong metasomatic effect that introduced radiogenic Sr into the system. The granitoid data indicate instead a derivation from Mid-Proterozoic crust, probably with additions of mantle components. Full article

Flexible PbZr_0.52Ti_0.48O₃ (PZT) films have a wide application prospect in wearable devices. In this work, PZT films were fabricated on LaNiO₃–based Si substrates and mica substrates, respectively. The effects of Si substrates and mica substrates on the dielectric and ferroelectric properties of PZT films were studied. The stability of PZT films on different substrates was discussed by controlling temperature and frequency. The optimal annealing temperature for preparing PZT films on LaNiO₃–based Si substrates and mica substrates is 750 °C. The dielectric and ferroelectric properties of PZT films vary with the substrates. The diffraction peak of PZT films deposited on mica substrates shifted to the left compared with that deposited on Si substrates, due to difference of the expansion coefficients. The as–prepared PZT films exhibit a good ferroelectric property at a frequency in the range of 100 Hz~1000 Hz. Moreover, PZT films deposited on mica substrates have larger remanent polarization values and coercive fields than PZT films deposited on Si substrates. With the elevation in temperature, the dielectric constant of PZT films gradually enhance. And as–prepared PZT films at an annealing temperature of 750 °C have a better dielectric temperature stability. PZT films grown on Si substrates exhibit more excellent dielectric temperature stability than that of PZT films grown on mica substrates. Full article

Himalayan leucogranite is an excellent target for understanding the orogenic process of the India–Asia collision, but its origin and tectonic significance are still under debate. An integrated study of geochronology, geochemistry, and in situ Sr-Nd-Hf isotopes was conducted for a tourmaline-bearing leucogranite in the eastern Tethyan Himalaya using LA-ICP-MS, X-ray fluorescence spectroscopy, and ICP-MS and LA-MC-ICP-MS, respectively. LA-ICP-MS U-Pb dating of zircon and monazite showed that it was emplaced at ~19 Ma. The leucogranite had high SiO₂ and Al₂O₃ contents ranging from 73.16 to 73.99 wt.% and 15.05 to 15.24 wt.%, respectively. It was characterized by a high aluminum saturation index (1.14–1.19) and Rb/Sr ratio (3.58–6.35), which is characteristic of S-type granite. The leucogranite was enriched in light rare-earth elements (LREEs; e.g., La and Ce) and large ion lithophile elements (LILEs; e.g., Rb, K, and Pb) and depleted in heavy rare-earth elements (e.g., Tm, Yb, and Lu) and high field strength elements (HFSEs; e.g., Nb, Zr, and Ti). It was characterized by high I Sr (t) (0.7268–0.7281) and low ε Nd (t) (−14.6 to −13.2) and ε Hf (t) (−12.6 to −9.47), which was consistent with the isotopic characteristics of the Higher Himalayan Sequence. Petrogenetically, the origin of the leucogranite is best explained by the decompression-induced muscovite dehydration melting of an ancient metapelitic source within the Higher Himalayan Sequence during regional extension due to the movement of the South Tibetan Detachment System (STDS). The significantly high lithium and beryllium contents of the leucogranite and associated pegmatite suggest that Himalayan leucogranites possess huge potential for lithium and beryllium exploration. Full article

In this study, to develop the composition ceramics for the application of an ultrasonic transducer device for alleviating temporomandibular joint disorder pain, Pb_0.88 (La_0.6 Sm_0.4)_0.08(Mn_1/3 Sb_2/3)_0.02Ti_0.98 O₃ ceramics were manufactured using CuO as sintering aids, and their piezoelectric and resonant properties were investigated. For the specimen sintered at 1200 °C, excellent values of piezoelectric properties appeared: the dielectric constant (εr) of 202, piezoelectric constant (d₃₃) of 56 pC/N, first and third overtone electromechanical coupling factors k_t of 0.548 and k_t3 of 0.219, and first and third overtone mechanical quality factors Q_mt1 of 345 and Q_mt3 of 292, respectively, made the device suitable for application as an ultrasonic transducer. When the length of the piezoelectric device was 7.7 mm, the first and third overtone electromechanical coupling factors k_t1 of 0.555 and k_t3 of 0.196, first and third overtone mechanical quality factors Q_mt1 of 381 and Q_mt3 of 393, and first and third overtone dynamic ratios (D.Rs) of 63.7 (dB) and 37.7 (dB) were suitable for device applications as an ultrasonic transducer and facial skin massage, respectively. Full article

Objective: to identify advanced or “so-called inoperable” cases of tympanojugular paragangliomas (PGLs) and analyze how each case is surgically managed and followed afterward. Study Design: a retrospective case series study. Methods: Out of 262 type C and D TJPs and more than 10 cases of advanced or so-called inoperable cases, files of 6 patients with a diagnosis of advanced tympanojugular PGLs who were referred to an otology and skull-base center between 1996 and 2021 were reviewed to analyze management and surgical outcomes. The criteria for choosing these cases involve having one or more of the following features: (1) a large-sized tumor; (2) a single ipsilateral internal carotid artery (ICA); (3) involvement of the vertebral artery; (4) a considerable involvement of the ICA; (5) an extension to the clivus, foramen magnum, and cavernous sinus; (6) large intradural involvement (IDE); and (7) bilateral or multiple PGLs. Results: The age range at presentation was 25–43 years old, with a mean of 40.5 years: two females and four males. The presenting symptoms were glossal atrophy, hearing loss, pulsatile tinnitus, dysphonia, shoulder weakness, and diplopia. The modified Infratemporal Fossa Approach (ITFA) with a transcondylar–transtubercular extension is the principal approach in most cases, with additional approaches being used accordingly. Conclusions: The contemporary introduction of carotid artery stenting with the direct and indirect embolization of PGLs has made it possible to operate on many cases, which was otherwise considered impossible to treat surgically. Generally, the key is to stage the removal of the tumor in multiple stages during the management of complex PGLs to decrease surgical morbidities. A crucial aspect is to centralize the treatment of PGLs in referral centers with experienced surgeons who are trained to plan the stages and manage possible surgical complications. Full article

Escherichia coli (E. coli) was among the first organisms to have its complete genome published (Genome Sequence of E. coli 1997 Science). It is used as a model system in microbiology research. E. coli can cause life-threatening illnesses, particularly in children and the elderly. Possible contamination by the bacteria also results in product recalls, which, alongside the potential danger posed to individuals, can have significant financial consequences. We report the detection of live Escherichia coli (E. coli) in liquid samples using a biosensor based on a field-effect transistor (FET) biosensor with B/N co-coped reduced graphene oxide (rGO) gel (BN-rGO) as the transducer material. The FET was functionalized with antibodies to detect E. coli K12 O-antigens in phosphate-buffered saline (PBS). The biosensor detected the presence of planktonic E. coli bacterial cells within a mere 2 min. The biosensor exhibited a limit of detection (LOD) of 10 cells per sample, which can be extrapolated to a limit of detection at the level of a single cell per sample and a detection range of at least 10–10⁸ CFU/mL. The selectivity of the biosensor for E. coli was demonstrated using Bacillus thuringiensis (B. thuringiensis) as a sample contaminant. We also present a comparison of our functionalized BN-rGO FET biosensor with established detection methods of E. coli k12 bacteria, as well as with state-of-the-art detection mechanisms. Full article

Zircon, with a chemical formula of ZrSiO₄, is a widely used mineral for determining the crystallization age of igneous rocks. It is also used to constrain the timing of metamorphic events from its overgrowth or recrystallized domains. Furthermore, detrital zircon grains can provide information on the sedimentary provenance. Due to the trace amounts of uranium (parent) which decays into its daughter element (Pb), it is a prime geochronometer for the majority of magmatic and metamorphic rocks. With high-precision analytical instruments, such as TIMS, SIMS, and LA-ICP-MS, huge amounts of geochronological and trace element data from zircon have been generated around the globe to date. Target domains within zircon grains are analyzed to extract geochemical and geochronological records using spatially resolved techniques such as ion probes or laser ablation coupled with mass spectrometry. Before any such analysis, the zircon grains are examined for internal structures, growth zoning, and the presence of tiny inclusions. However, many researchers analyze multiple domains within single zircon grains for U-Pb isotope analysis with little regard for their internal structures, particularly crystallographic orientations. Hence, they may obtain mixed ages with variable discordance, leading to imprecise interpretation especially when the growth domains are not well-identified. Particularly, zircon grains that contain multi-growth domains or have local internal deformations within a single grain may not produce geologically meaningful age results if the analyses are conducted on mixed domains. This study presents a brief review on zircon geochronology, how to identify and visualize micro-deformations in metamorphic zircons through the EBSD analysis, and the effects of micro-deformation on age results. Examples from a case study conducted on zircons hosted in the Himalayan high-pressure eclogites are presented that show intra-grain plastically deformed domains and their effects on the corresponding age results. Full article

In this study, the thermodynamic simulation model and system of the copper side-blown smelting process were established using the chemical equilibrium constant method, based on the process reaction mechanism, multiphase equilibrium principle, and MetCal software platform (MetCal v7.81). Under typical production conditions, the composition of the product and the distribution behavior of impurity elements were simulated. The results indicate that the average relative error between the calculated mass fractions of major elements such as Cu, S, Fe, SiO₂, CaO, MgO, and Al₂O₃ in copper matte and smelting slag, and the actual production values, is 4.25%. Additionally, the average relative error between the calculated distribution ratios of impurity elements such as Pb, Zn, As, Bi, Mo, Au, and Ag in copper matte and smelting slag, and the actual production data, is 6.74%. Therefore, this model and calculation system accurately reflects the actual production situation of the copper side-blown smelting process well and has potential to predict process output accurately while optimizing process parameters, effectively guiding production practice. Full article

This work describes the process of synthesizing magnesia (MgO) nanomaterials through ultrasonic electrodeposition, followed by an examination of their ability and mechanism to remove Pb(II) from industrial soil at 100, 150, and 200 W ultrasonic powers. Nanomaterials were examined for their surface shape and phase composition using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffractometry (XRD). The capability of magnesia nanomaterials to adsorb Pb(II) improved greatly when operated at 150 W, attaining a maximal 68.94 mg/g value. Adsorption of Pb(II) onto magnesia nanomaterial surfaces was examined by utilizing the pseudo-second-order kinetic and Langmuir models. The nanomaterials exhibited significant features of both chemical and monolayer adsorptions for Pb(II) as a result of the intense chemical interactions between the atoms of the magnesia nanomaterials’ surface and Pb(II), as shown by Fourier transform infrared (FTIR) analysis. At 30 °C, the magnesia nanomaterial exhibited the highest adsorption capacity for Pb(II), suggesting that temperature played a significant role in this capacity. Furthermore, the Langmuir model produced a correlation coefficient greater than 0.99, indicating an excellent fit for the adsorption behavior of magnesia towards Pb(II). The findings suggest that ultrasonic power significantly impacts the adsorption characteristics of magnesia nanoparticles synthesized via ultrasonic electrodeposition. Specifically, ultrasonic power of 150 W yields the most efficient adsorption characteristics. Moreover, the 150 W-fabricated magnesia materials demonstrated exceptional pH compatibility. Full article

Petrological, geochronological, and geochemical analyses of mafic rocks in northern Liaoning were conducted to constrain the formation age of the Proterozoic strata, and to further study the source characteristics, genesis, and tectonic setting. The mafic rocks in northern Liaoning primarily consist of basalt, diabase, gabbro, and amphibolite. Results of zircon U-Pb chronology reveal four stages of mafic magma activities in northern Liaoning: the first stage of basalt (2209 ± 12 Ma), the second stage of diabase (2154 ± 15 Ma), the third stage of gabbro (2063 ± 7 Ma), and the fourth stage of magmatic protolith of amphibolite (2018 ± 13 Ma). Combined with the unconformity overlying Neoproterozoic granite, the formation age of the Proterozoic strata in northern Liaoning was found to be Paleoproterozoic rather than Middle Neoproterozoic by the geochronology of these mafic rocks. A chronological framework of mafic magmatic activities in the eastern segment of the North China Craton (NCC) is proposed. The mafic rocks in northern Liaoning exhibit compositional ranges of 46.39–50.33 wt% for SiO₂, 2.95–5.08 wt% for total alkalis (K₂O + Na₂O), 6.17–7.50 wt% for MgO, and 43.32–52.02 for the Mg number. TiO₂ contents lie between 1.61 and 2.39 wt%, and those of MnO between 0.17 and 0.21 wt%. The first basalt and the fourth amphibolite show low total rare earth element contents. Normalized against primitive mantle, they are enriched in large ion lithophile elements (Rb, Ba, K), depleted in high field strength elements (Th, U, Nb, Ta, Zr, Ti), and exhibit negative anomalies in Sr and P, as well as slight positive anomalies in Zr and Hf. The second diabase and the third gabbro have similar average total rare earth element contents. The diabase shows slight negative Eu anomalies (Eu/Eu* = 0.72–0.88), enrichment in large ion lithophile elements (Ba), depletion in Rb, and slight positive anomalies in high field strength elements (Th, U, Nb, Ta, Zr, Hf, Ti), with negative anomalies in K, Sr, and P. The gabbro is enriched in large ion lithophile elements (Rb, Ba, K), depleted in high field strength elements (Th, U, Nb, Ta, Zr, Hf), and exhibits positive anomalies in Eu (Eu/Eu* = 1.31–1.37). The contents of Cr, Co, and Ni of these four stages of mafic rocks are higher than those of N-MORB. The characteristics of trace element ratios indicate that the mafic rocks belong to the calc-alkaline series and originate from the transitional mantle. During the process of magma ascent and emplacement, it is contaminated by continental crustal materials. There are residual hornblende and spinel in the magma source of the first basalt. The other three magma sources contain residual garnet and spinel. The third gabbro was formed in an island arc environment, and the other three stages of mafic rocks originated from the Dupal OIB and were formed in an oceanic island environment. The discovery of mafic rocks in northern Liaoning suggests that the Longgang Block underwent oceanic subduction and extinction in both the north and south in the Paleoproterozoic, indicating the possibility of being in two different tectonic domains. Full article

Perovskite solar cells with an indium tin oxide (ITO)/SnO₂/CH₃NH₃PbI₃/Spiro-OMeTAD/2,2,2-trifluoroethanol (TFE) doped single-walled carbon nanotube (SWCNT) structure were developed by dropping TFE onto SWCNTs, which replaced the metal back electrode, and a conversion efficiency of 14.1% was achieved. Traditionally, acidic doping of the back electrode, SWCNT, has been challenging due to the potential damage it may cause to the perovskite layer. However, TFE has facilitated easy doping of SWCNT as the back electrode. The sheet resistance of the SWCNTs decreased and their ionization potential shifted to deeper levels, resulting in improved hole transport properties with a lower barrier to carrier transport. Furthermore, the Seebeck coefficient (S) increased from 34.5 μV/K to 73.1 μV/K when TFE was dropped instead of EtOH, indicating an enhancement in the behavior of p-type charge carriers. It was observed that hydrophilic substances adhered less to the SWCNT surface, and the formation of PbI₂ was suppressed. These effects resulted in higher conversion efficiency and improved solar cell performance. Furthermore, the decrease in conversion efficiency after 260 days was suppressed, showing improved durability. The study suggests that combining SWCNTs and TFEs improves solar cell performance and stability. Full article

The Paleocene ore deposits related to the India–Asia continental collision are widely distributed in the Gangdese metallogenic belt. Among these, Sinongduo is the first discovered epithermal Ag-Pb-Zn deposit in the Lhasa terrane. However, there is still controversy over the ore-forming magma in this deposit. This study mainly reports new zircon U-Pb isotopic ages, whole-rock geochemistry, and Sr-Nd isotopic data for the granite porphyry from the Sinongduo deposit, aiming to discuss the petrogenesis and tectonic setting of the granite porphyry and its genetic link between the Ag-Pb-Zn mineralization. The results show that zircon U-Pb analyses yield ages of 62.9 ± 0.5 Ma and 59.0 ± 0.7 Ma for the granite porphyry, indicating that it formed during the Paleocene period. The timing of the granite porphyry intrusion is contemporaneous with the mineralization, suggesting that it is most likely the ore-forming magma in the Sinongduo deposit. The granite porphyry has high SiO₂ and K₂O, moderate Al₂O₃, and low Na₂O, CaO, and FeO^T contents, and it displays significant enrichments in LREEs and LILEs and depletions in HREEs and HFSEs, with negative Eu anomaly. The granite porphyry is a peraluminous series and can be classified as S-type granite. Moreover, the granite porphyry shows relatively high ratios of (⁸⁷Sr/⁸⁶Sr)_i and low values of ε_Nd(t). The geochemical and isotopic compositions of the granite porphyry from the Sinongduo area are similar to those of the upper continental crust, which suggests that the granite porphyry was most likely derived from the melting of the upper continental crust in the Lhasa terrane during the India–Asia collisional tectonic setting. Full article