Mixed Pb Research Articles

PE/PP fibrous adsorbents with bifunctional groups of tertiary amine and phosphate prepared by electron beam induced co-grafting for heavy metal adsorption of both cationic and anionic forms in acidic conditions

A novel fabric adsorbent having bifunctional groups of tertiary amine and phosphate was prepared by co-graft polymerization of 2-diethylaminoethyl methacrylate (NMA) and 2-hydroxyethyl methacrylate phosphate (PMA) onto a polyethylene/polypropylene nonwoven fabric (PE/PP NF) under low-energy electron beam acceleration. The process involved pre-irradiating the fabric and immersing it in the comonomer solution for grafting. The kinetics of radiation-induced graft polymerization at a total dose of 100 kGy was investigated. For pre-irradiation at 100 kGy, the optimum condition offering highest degree of grafting was at 12 wt% of NMA, 8 wt% of PMA and 4 h of reaction time. The adsorption of anions using hydrogen chromate (HCrO4−) or Cr(VI) and cations using lead (Pb(II)), cadmium (Cd(II)) and copper (Cu(II)) in aqueous solution was carried out. The results demonstrated that the bifunctional adsorbent was able to adsorb both heavy metal anionic and cationic ions from water. The co-grafted adsorbents with tertiary amine and phosphate were able to adsorb 85 % Cr(VI) anion and 29 % Pb(II) cations from mixed Cr(VI) and Pb(II) solution at pH 3.0 and 71 % Pb(II), 13 % Cd(II) and 31 % Cu(II) from mixed Pb(II), Cd(II) and Cu(II) solution at pH 5.0. The unique achievement of this study is its hypothesis that a bifunctional adsorbent can be prepared from radiation-induced graft polymerization of two different monomers onto NF, along with proof that the prepared bifunctional adsorbent can actually absorb both cationic or anionic heavy metals forms. Additionally, the adsorbent's preparation offers a rapid and straightforward one-step grafting technique. Therefore, the new bifunctional adsorbents can remove heavy metal ions in aqueous solution, either in the cation or anion form, thus offering highly promising applications in industrial wastewater treatment.

Unraveling the Positive Effects of Glycine Hydrochloride on the Performance of Pb–Sn‐Based Perovskite Solar Cells

Additives are commonly used to increase the performance of metal‐halide perovskite solar cells, but detailed information on the origin of the beneficial outcome is often lacking. Herein, the effect of glycine hydrochloride is investigated when used as an additive during solution processing of narrow‐bandgap mixed Pb–Sn perovskites. By combining the characterization of the photovoltaic performance and stability under illumination, with determining the quasi‐Fermi level splitting, time‐resolved microwave conductivity (TRMC), and morphological and elemental analysis a comprehensive insight is obtained. Glycine hydrochloride is able to retard the oxidation of Sn2+ in the precursor solution, and at low concentrations (1–2 mol%) it improves the grain size distribution and crystallization of the perovskite, causing a smoother and more compact layer, reducing non‐radiative recombination, and enhancing the lifetime of photogenerated charges. These improve the photovoltaic performance and have a positive effect on stability. By determining the quasi‐Fermi level splitting on perovskite layers without and with charge transport layers it is found that glycine hydrochloride primarily improves the bulk of the perovskite layer and does not contribute significantly to passivation of the interfaces of the perovskite with either the hole or electron transport layer (ETL).

Enhanced removal of lead ions from wastewaters by electrochemical adsorption using nitrogen-doped Ti3C2Tx MXene

As a two-dimensional material containing transition metal carbides and nitrides, MXene is often used in capacitive deionization for its excellent hydrophilic and pseudocapacitive properties. Nitrogen doping is widely used to improve the adsorption properties of certain materials. However, the effect of nitrogen doping on the electrochemical adsorption properties of MXene remains unclear. In this work, nitrogen-doped Ti3C2Tx MXene was synthesized using a simple hydrothermal method to achieve highly selective and efficient removal of Pb(II) at a constant cell voltage. The concentration of Pb(II) decreased from 4.95 to 0.02 mg L−1 in a 100 mg L−1 NaCl supporting electrolyte after electrosorption. The removal efficiency of Pb(II) reached 99.5%, whereas it was only 15.2% for Na+. The introduction of nitrogen functional groups increased the electrical conductivity and layer spacing of MXene, thereby improving the pseudocapacitive adsorption performance in the presence of Pb(II). The complexation function of the Ti-OH group on nitrogen-doped Ti3C2Tx surface increased and contributed to the selective adsorption of Pb(II). The removal efficiency of Pb(II) increased with increasing solution pH and cell voltage, reaching the maximum value at pH 5.0 and 1.5 V, respectively. The effect of supporting electrolyte type on the removal of Pb(II) was negligible. In addition, the removal efficiency for mixed heavy metal ion solutions, including Cu(II), Ni(II), and Pb(II), exceeded 79.0%. It exhibited the highest removal efficiency for Pb(II) at 97.9%. After five cycles of electrochemical adsorption–desorption, the nitrogen-doped Ti3C2Tx maintained a stable Pb(II) removal efficiency of 97.0%. This work provides a promising material for the electrochemical removal of low-concentration heavy metal ions from wastewaters.

Super-stable mineralization of arsenic contaminated water using industrialized layered double hydroxides and derivatives

The issue of arsenic contamination, specifically in the form of As(III), is progressively escalating, so presenting a substantial danger to human well-being and security. In this study, commercially industrially produced CaAl-layered double hydroxides (CaAl-LDH) and MgAl-LDH were processed by calcination to produce a series of LDH-based mixed metal oxides (CaAl-x, MgAl-x) at calcination temperatures (x) ranging from 200 to 1000 °C. The resulting CaAl-900 exhibited a remarkable capacity for removing high concentrations of As(III), with a removal capacity of 612.5 mg/g. Besides, MgAl-500 demonstrated effective removal of low levels of As(III) to meet industrial emission standards, specifically below 0.5 mg/L. Furthermore, MgAl-500 was employed to simultaneously stabilize mixed toxic metals (As(III), Pb(II), and Cd(II) ions) in the treatment process of contaminated water, meeting standard levels. The comprehensive analysis of the characterization data indicated that the key determinant for the remarkable capacity of CaAl-900 to remove As(III) was its surface adsorption and memory effect. MgAl-500 also formed complex compounds through formation of As-O-Mg bond. This research showcases the capacity of LDHs produced from the industry for efficient remediation of As(III) ions in water.

Stabilizing Solution–Substrate Interaction of Perovskite Ink on PEDOT:PSS for Scalable Blade Coated Narrow Bandgap Perovskite Solar Modules by Gas Quenching

The development of scalable 1.25 eV mixed Pb–Sn perovskite solar modules by blade coating lags behind Pb‐based perovskites due to limited understanding of solution–substrate interaction of the perovskite ink on PEDOT:PSS and subsequent gas quenching. To address this challenge, the wet film deposition and quenching process to better understand narrow bandgap perovskite film formation on PEDOT:PSS are studied. It is found that the wetting of Pb–Sn perovskite ink on PEDOT:PSS is highly unstable over relevant coating time scales, causing the contact angles to decrease rapidly from 42° to 16° within seconds. This instability leads to localized irregularities in the wet film, resulting in uneven solvent extraction and inhomogeneous nuclei density. As a result, rough perovskite films with voids at the buried interface are obtained. To overcome this problem, a quasistatic wetting process by reducing the blade coating speed is developed, thereby stabilizing the wetting behavior of Pb–Sn perovskite precursor ink on PEDOT:PSS. This optimized process facilitates the deposition of high‐quality, void‐free Pb–Sn perovskite films with uniform thickness over 8 cm of coating length using moderate (1.4 bar) N2 quenching. 20% efficient narrow bandgap perovskite solar cells and minimodules with 15.8% active area efficiency on 15.9 cm2 are achieved.

Development of a split G-quadruplex and DAPI-based fluorescent probe for Hg(II) and Pb(II) ions detection.

A novel thymine- and guanine-rich oligonucleotide (ODN-7) was engineered explicitly for the detection of Hg(II) and Pb(II) by a single intercalated dye 4',6-diamidinyl-2-phenylindole (DAPI). Upon the introduction of Hg(II), a rapid formation of T-Hg(II)-T base pairs takes place, triggering the assembly of a split G-quadruplex structure, resulting in a strong fluorescence signal due to DAPI intercalating into the T-Hg(II)-T mismatch. The introduction of Pb(II) initiates an interaction with the split G-quadruplex, causing a significant conformational change in its structure. Consequently, the altered split G-quadruplex structure fails to facilitate the insertion of DAPI into the T-Hg(II)-T complexes, leading to fluorescence quenching. This strategy offers a straightforward means of detecting Hg(II) and Pb(II). Leveraging the split G-quadruplex, the ODN-7 sensor enables the detection limits (3σ) for Hg(II) and Pb(II) to reach an impressive low of 0.39 nM and 4.98 nM, respectively. It exhibited a favorable linear range of 0.39-900 nM for Hg(II) detection (R2 = 0.9993) and 4.98 nM-5 μM for Pb(II) determination (R2 = 0.9953), respectively. Furthermore, the proposed sensor had excellent selectivity for detecting Hg(II) and Pb(II). It was used in milk samples containing mixed Hg(II) and Pb(II) solutions, yielding recovery rates of 99.3-103.8% for Hg(II) detection and 100.1-104.1% for Pb(II) detection.

Advancing Efficiency and Stability of Lead, Tin, and Lead/Tin Perovskite Solar Cells: Strategies and Perspectives

Halide‐perovskite‐based solar cells (HPSCs) have established themselves as a promising photovoltaic (PV) technology in a remarkably short time. The rapid improvement in HPSCs can be attributed to the unique material and optoelectronic properties of metal halide perovskite semiconductors coupled with a very knowledgeable and experienced PV community. This review briefly summarizes the chemistry of halide perovskites, delving into the fundamental aspects of crystal structure and optical bandgap, followed by a more in‐depth report on the advancements in HPSCs efficiencies, thanks to structural regulation, interfacial modulation, and thin‐film engineering. It is mainly focused on three metal halide perovskites topics: 1) high‐performance Pb‐based perovskites, 2) Sn‐based perovskites and their associated challenges, and 3) emerging work on mixed composition Pb–Sn perovskites. For each of these domains, the effects stemming from the tuning of the monovalent A‐site and the halide site are examined. Additionally, various approaches aimed at passivating defects in the bulk film and at the interface, along with carrier transport engineering, are discussed. The discussions also encompass the broader implications for device performance, stability, and material toxicity. Finally, perspectives on the future directions and the commercial feasibility of perovskite photovoltaic technologies are provided.

FA/Cs-based mixed Pb–Sn perovskite solar cells: A review of recent advances in stability and efficiency

Perovskite solar cells (PSCs) have gained widespread attention due to their impressive optoelectronic properties, extraordinarily high efficiency, and low-cost manufacturing processes. PSCs are poised to usher in a new era of clean energy production. However, the use of methylammonium (MA) as the A-site cation in PSCs may result in poor thermal and atmospheric stability, limiting their potential for widespread commercialization. On the other hand, the most extensively studied perovskite systems with respect to B-site cations are pure Pb-based compositions due to their high device performance demonstrated to date. However, mixed Pb–Sn compositions can offer optimal bandgap energies for single-junction solar cells, suggesting the promise of future efficiency improvements. Thus, this review focuses on mixed Pb–Sn perovskite solar cells that use formamidinium (FA) or mixed cations of FA and cesium (Cs) without MA. These materials have bandgap energies suitable for use in either single-junction or multi-junction solar cells and show improved stability compared to their MA-based counterparts. We discuss the structural and optoelectronic properties of FA/Cs-based Pb–Sn perovskites and the efforts to improve their solar cell performance and stability through additive engineering, process optimization, and structural modifications. Our review highlights the potential for FA/Cs-based mixed Pb–Sn perovskites as a more stable and efficient alternative for future commercial applications of PSCs.

Additive Engineering for Mixed Lead–Tin Narrow-Band-Gap Perovskite Solar Cells: Recent Advances and Perspectives

Low-cost perovskite solar cells (PSCs) with high power conversion efficiencies (PCEs) of >25% are considered as the most promising replacement for commercial silicon-based solar cells to realize a sustainable future. To break the theoretical PCE limits of single-junction PSCs, all-perovskite tandem solar cells consisting of a narrow-band-gap bottom subcell and a wide-band-gap top subcell have attracted particular attention recently. Mixed Pb–Sn perovskites with narrow band gaps have received great attention as an efficient light harvester in the bottom subcell of all-perovskite tandem solar cells as a result of the reduced toxicity, high light-absorbing capability, and matched current with the wide-band-gap top subcells. However, mixed Pb–Sn narrow-band-gap PSCs suffer from low PCEs, inferior stability, and high open-circuit voltage (Voc) loss, owing to the high defect amount and inferior perovskite film quality induced by the detrimental oxidation of Sn2+ cations and the rapid crystallization of perovskite crystals. Herein, the recent advances about the additive engineering for mixed Pb–Sn narrow-band-gap PSCs are reviewed by demonstrating the origins and unique features of Pb–Sn narrow-band-gap perovskites. Additionally, several strategies to improve PCEs and durability of Pb–Sn narrow-band-gap PSCs through additive engineering are proposed, including Sn2+ cation stabilization, heterojunction construction, crystallization control, surface/grain boundary passivation, film morphology control, carrier dynamics modulation, and gradient-distributed film formation. Furthermore, the existing challenges and future directions are also presented, aiming to provide important insights for designing and developing efficient and stable single-junction narrow-band-gap PSCs and all-perovskite tandem solar cells.

Bidirectional Anions Gathering Strategy Afford Efficient Mixed PbSn Perovskite Solar Cells.

Mixed lead-tin (PbSn) perovskite solar cells (PSCs) possess low toxicity and adjustable bandgap for both single-junction and all-perovskite tandem solar cells. However, the performance of mixed PbSn PSCs still lags behind the theoretical efficiency. The uncontrollable crystallization and the resulting structural defect are important reasons. Here, the bidirectional anions gathering strategy (BAG) is reported by using Methylammonium acetate (MAAc) and Methylammonium thiocyanate (MASCN) as perovskite bulk additives, which Ac- escapes from the perovskite film top surface while SCN- gathers at the perovskite film bottom in the crystallization process. After the optoelectronic techniques, the bidirectional anions movement caused by the top-down gradient crystallization is demonstrated. The layer-by-layer crystallization can collect anions in the next layer and gather at the broader, enabling a controllable crystallization process, thus getting a high-quality perovskite film with better phase crystallinity and lower defect concentration. As a result, PSCs treated by the BAG strategy exhibit outstanding photovoltaic and electroluminescent performance with a champion efficiency of 22.14%. Additionally, it demonstrates excellent long-term stability, which retains ≈92.8% of its initial efficiency after 4000 h aging test in the N2 glove box.

Genesis and prospecting significance of the Buziwannan gold-polymetallic ore deposit in the West Kunlun Orogen Belt, China: Constraints from mineral geochemistry and in situ S–Pb isotope analyses of sulfides

The Buziwannan gold-polymetallic deposit is located in Northwest China's West Kunlun Orogen Belt (WKOB). There are two metallogenic stages that have been identified: skarn and hydrothermal. In this research study, in situ mineral geochemistry and sulfur–lead isotopes are used to precisely constrain the genesis and ore-forming process.Pyrite is the most dominant sulfide, and four types have been identified. Py0 is a sedimentary euhedral crystal; Py1 is a subhedral grain occurring in skarn ores, and coexists with Po1, Apy1, Ccp1 and Gn1; Py2, which coexists with Apy2, Po2 and Ccp2, is a subhedral to irregular crystal; and Py3 is a colloform crystal. Gn2 is the most recent sulfide. Magnetite and Ccp1 LA–ICMPS analyses indicate a skarn origin. Py0 and Py1 have the highest Co/Ni ratios and Ni contents, respectively, and Au has positive correlations with Pb, Ag and As, according to the trace element compositions of pyrite (LA–ICPMS). With the exception of four spots, most pyrites have Au (0.01–30.23 ppm) and As (1.47–15,709 ppm) concentrations below the Au saturation line, indicating that the majority of gold is present as lattice bound Au+. Py3 has clearly higher Sb contents indicating that Sb-rich fluids were added.The δ34S values of sulfides show that the sedimentary Py0 and skarn sulfides have the highest and lowest δ34S values of +13.30 to +14.67 ‰ and +4.48 to +7.77 ‰, respectively, and other sulfides possess δ34S values that fall between the two members, indicating a mixed source of magmatic and sedimentary. The lead isotope values also indicate that the sulfides from the hydrothermal stage have a mixed Pb source of magmatic and sedimentary.The skarn ores are spatially and genetically related to the Triassic granodiorite, indicating a Triassic age for ore formation. The Triassic magmatic intrusions hold the potential for future gold deposit exploration in the WKOB.

Fabrication of nitrogen-doped graphene quantum dots hybrid membranes and its sorption for Cu(II), Co(II) and Pb(II) in mixed polymetallic solution

With the rapid development of new–energy batteries, heavy-metals pollution from spent batteries has drawn much attention. Various techniques are recently proposed to delete or eliminate such pollution. Among which, membrane sorption exhibits exceptional advantages for the separation of multi-metal solution. For such a purpose, nitrogen-doped graphene quantum dots (N-GQDs) hybrid membranes were fabricated via sol–gel technique and hydrothermal synthesis, in which the precursor powder of N-GQDs was obtained by the combination of urea (used as a nitrogen source) and citric acid (used as a carbon source). Subsequently, the N-GQDs precursor was mixed with silane and PVA to generate N-GQDs hybrid membranes (NHMs). Competitive sorption of Cu(II), Co(II) and Pb(II) in the mixed polymetallic solution, such as a mixed Cu(II), Co(II) and Pb(II) ternary solution, a mixed Cu(II), Pb(II), Ca(II), Co(II) and Cr(III) quintuple solution, was investigated. It indicated that Cu(II) sorption on NHMs had better selectivity in these mixed polymetallic solutions. Moreover, sorption mechanism of Cu(II), Co(II) and Pb(II) demonstrates that the sorption of NHMs for Cu(II) and Pb(II) abided by Elovich model, indicating the properties of heterogeneous chemisorption. Such a trend shows that the sorption via chemical process between the active sites on the top-layer of NHMs, and Cu(II) and Pb(II) is one of the dominant interfering factors. Desorption testing demonstrated that EDTA-2Na is a best de-sorbent for Cu(II) sorption on NHMs and the number of cycles of these membranes can reach up to 10 times. These findings suggest that NHMs can be used to adsorb Cu(II), Co(II) and Pb(II) from mixed polymetallic solution, indicating promising applications in the successive separation of wastewater containing multiple mixed toxic metals from spent new-energy batteries and other metal-containing wastewater.

Effects of intermetallic phases on electrochemical properties of powder metallurgy Mg-6%Al-5%Pb anode alloy used for seawater activated battery

The changes in intermetallic phases of Mg-6%Al-5%Pb (Mg-Al-Pb) alloy prepared by powder metallurgy and their effects on electrochemical properties were studied. Experimental results showed that coarse Mg17Al12 phases (with size ranges from 20 μm to 70 μm) and fine Mg2Pb phases (with the size of 100 nm scale) formed in the mixed Al, Pb and Mg powder during the hot press sintering procedure. Fine Mg2Pb phases exhibit strong diffusional ability to diffuse into Mg17Al12 phases. Extruding further promotes the diffusion of Mg2Pb phases into Mg17Al12 phases. Solution treatment produced a mixed microstructure which is Mg17Al12 phase containing Mg2Pb phases inside and made other Mg2Pb phases homogeneously distributed in Mg matrix. Mg17Al12 phases and the gathered Mg2Pb phases will accumulate the Mg(OH)2 corrosion products, which impedes the subsequent discharge behavior. Homogeneously distributed Mg2Pb phases will fall off during discharge, which makes the discharge curve more stable. The mixed microstructure has positive effect on corrosion resistance and discharge potential. Therefore, solution-treated alloy shows the highest negative potential and the smoothest curve during the galvanostatic discharge test. Compared with the commercial AZ61 sheet, solution-treated alloy exhibit much higher anode properties in Mg/PbCl2 battery test. Thus, the solution-treated alloy could serve as an excellent anode in seawater-activated batteries.

Compositional Variation in FAPb1-xSnxI3 and Its Impact on the Electronic Structure: A Combined Density Functional Theory and Experimental Study.

Given their comparatively narrow band gap, mixed Pb–Sn iodide perovskites are interesting candidates for bottom cells in all-perovskite tandems or single junction solar cells, and their luminescence around 900 nm offers great potential for near-infrared optoelectronics. Here, we investigate mixed FAPb1–xSnxI3 offering the first accurate determination of the crystal structure over a temperature range from 293 to 100 K. We demonstrate that all compositions exhibit a cubic structure at room temperature and undergo at least two transitions to lower symmetry tetragonal phases upon cooling. Using density functional theory (DFT) calculations based on these structures, we subsequently reveal that the main impact on the band gap bowing is the different energy of the s and p orbital levels derived from Pb and Sn. In addition, this energy mismatch results in strongly composition-dependent luminescence characteristics. Whereas neat and Sn-rich compounds exhibit bright and narrow emission with a clean band gap, Sn-poor compounds intrinsically suffer from increased carrier recombination mediated by in-gap states, as evidenced by the appearance of pronounced low-energy photoluminescence upon cooling. This study is the first to link experimentally determined structures of FAPb1–xSnxI3 with the electronic properties, and we demonstrate that optoelectronic applications based on Pb–Sn iodide compounds should employ Sn-rich compositions.

Ultrasensitive Near-Infrared Circularly Polarized Light Detection Using 3D Perovskite Embedded with Chiral Plasmonic Nanoparticles.

Chiral organic ligand‐incorporated low‐dimensional metal‐halide perovskites have received increasing attention for next‐generation photodetectors because of the direct detection capability of circularly polarized light (CPL), which overcomes the requirement for subsidiary optical components in conventional CPL photodetectors. However, most chiral perovskites have been based on low‐dimensional structures that confine chiroptical responses to the ultraviolet (UV) or short‐wavelength visible region and limit photocurrent due to their wide bandgap and poor charge transport. Here, chiroptical properties of 3D Cs0.05FA0.5MA0.45Pb0.5Sn0.5I3 polycrystalline films are achieved by incorporating chiral plasmonic gold nanoparticles (AuNPs) into the mixed Pb—Sn perovskite, without sacrificing its original optoelectronic properties. CPL detectors fabricated using chiral AuNP‐embedded perovskite films can operate without external power input; they exhibit remarkable chirality in the near‐infrared (NIR) region with a high anisotropy factor of responsivity (g res) of 0.55, via giant plasmon resonance shift of chiral plasmonic AuNPs. In addition, a CPL detector array fabricated on a plastic substrate demonstrates highly sensitive self‐powered NIR detection with superior flexibility and durability.

Influence of intrinsic defects on the structure and dynamics of the mixed Pb–Sn perovskite: first-principles DFT and NAMD simulations

The mixed tin (Sn) and lead (Pb) perovskite compositions have shown great potential in perovskite photovoltaic devices due to the significantly enhanced material stability and prolonged carrier lifetime, compared to the pure Sn halide perovskites.

Highly Efficient Hole Transport Layer‐Free Low Bandgap Mixed Pb–Sn Perovskite Solar Cells Enabled by a Binary Additive System

AbstractThe development of high‐performance hole transport layer (HTL)‐free perovskite solar cells (PSCs) with a simplified device structure has been a major goal in the commercialization of PSCs due to the economic advantage of low manufacturing cost. Unfortunately, low bandgap (Eg) mixed Pb–Sn perovskites, which have promising utility for constructing efficient all‐perovskite tandem solar cells, have rarely been explored in simplified HTL‐free device configurations. In this study, efficient band bending and defect engineering at the interface between perovskite and indium tin oxide (ITO) are realized via a binary additive system using copper thiocyanate (CuSCN) and glycine hydrochloride (GlyHCl). Using mixed Pb–Sn perovskites decorated with crystalline p‐type CuSCN, the energy level alignment at the hole extractive interface is modulated in favor of hole extraction, simultaneously increasing hole mobility. Suppressed nonradiative carrier recombination in the perovskite bulk, or across the charge extractive interface, is further achieved by GlyHCl without disturbing the efficient hole transfer characteristics. Notably, a more optimized band alignment is achieved at the hole extractive interface with the addition of GlyHCl. The HTL‐free mixed Pb–Sn PSC shows an efficiency up to 20.1% under forward bias with negligible hysteresis, comparable to state‐of‐the‐art high‐performance full‐structured mixed Pb–Sn PSCs.

Superimposing porphyry Mo and vein-type Cu-Pb-Zn mineralization in the Panjiaduan deposit, Great Xing’an Range (NE China): Perspective from zircon U-Pb and sphalerite Rb-Sr dating, geochemistry and S-Pb isotopes

The southern Great Xing’an Range (SGXR) is located in the eastern Central Asian Orogenic Belt (CAOB), and represents the most important Cu-Mo-Pb-Zn polymetallic mineral province in NE China. The Panjiaduan deposit in the SGXR is characterized by superimposing mineralization: (1) porphyry Mo ore hosted by syenogranite, and (2) superimposing vein-type Cu-Pb-Zn ore, hosted by fracture zones in the Manitu Formation volcanics and granodiorite. Two zircon U-Pb ages of 233.9 ± 2.8 Ma and 236.1 ± 2.8 Ma for the syenogranite (porphyry) ore host indicate that the porphyry Mo mineralization occurred in the Late Triassic, coeval with the adjacent Laojiagou porphyry Mo deposit. Sphalerite from the Cu-Pb-Zn ore veins yielded a Rb-Sr isochron age of 138.5 ± 3.5 Ma, suggesting Early Cretaceous overprinting mineralization. The syenogranite is geochemically similar to the ore-causative monzogranite at Laojiagou. They are unfractionated I-type granites, LILE- and LREE-enriched, and HFSE- and HREE-depleted. In addition, their magma source was likely derived from partial melting of the juvenile lower crust. Major sulfides (pyrite, molybdenite, and galena) from the porphyry ores have slightly lower δ34S values (−2.8 to −0.3 ‰) than the vein-type ore sulfides (pyrite, chalcopyrite, sphalerite, and galena) (1.5 to 5.3 ‰), although they are all close to the mantle δ34S values and thus suggests a magmatic sulfur source. Meanwhile, the Pb isotope compositions of the two ore types suggest that the Pb for the porphyry mineralization was likely derived from an orogenic Pb reservoir, while the latter may have crust-mantle mixed Pb source. We suggested that both mineralization events were formed in an extensional setting, induced by the post-collision tectonics after the Paleo-Asian Ocean closure and the Paleo-Pacific subduction rollback, respectively.

Thermostructural and Elastic Properties of PbTe and Pb0.884Cd0.116Te: A Combined Low-Temperature and High-Pressure X-ray Diffraction Study of Cd-Substitution Effects

Rocksalt-type (Pb,Cd)Te belongs to IV–VI semiconductors exhibiting thermoelectric properties. With the aim of understanding of the influence of Cd substitution in PbTe on thermostructural and elastic properties, we studied PbTe and Pb0.884Cd0.116Te (i) at low temperatures (15 to 300 K) and (ii) at high pressures within the stability range of NaCl-type PbTe (up to 4.5 GPa). For crystal structure studies, powder and single crystal X-ray diffraction methods were used. Modeling of the data included the second-order Grüneisen approximation of the unit-cell-volume variation, V(T), the Debye expression describing the mean square atomic displacements (MSDs), <u2>(T), and Birch–Murnaghan equation of state (BMEOS). The fitting of the temperature-dependent diffraction data provided model variations of lattice parameter, the thermal expansion coefficient, and MSDs with temperature. A comparison of the MSD runs simulated for the PbTe and mixed (Pb,Cd)Te crystal leads to the confirmation of recent findings that the cation displacements are little affected by Cd substitution at the Pb site; whereas the Te displacements are markedly higher for the mixed crystal. Moreover, information about static disorder caused by Cd substitution is obtained. The calculations provided two independent ways to determine the values of the overall Debye temperature, θD. The resulting values differ only marginally, by no more than 1 K for PbTe and 7 K for Pb0.884Cd0.116Te crystals. The θD values for the cationic and anionic sublattices were determined. The Grüneisen parameter is found to be nearly independent of temperature. The variations of unit-cell size with rising pressure (the NaCl structure of Pb0.884Cd0.116Te sample was conserved), modeled with the BMEOS, provided the dependencies of the bulk modulus, K, on pressure for both crystals. The K0 value is 45.6(2.5) GPa for PbTe, whereas that for Pb0.884Cd0.116Te is significantly reduced, 33.5(2.8) GPa, showing that the lattice with fractional Cd substitution is less stiff than that of pure PbTe. The obtained experimental values of θD and K0 for Pb0.884Cd0.116Te are in line with the trends described in recently reported theoretical study for (Pb,Cd)Te mixed crystals.

Comparable Outcome of CD3+-/CD19+ Depleted Haploidentical with Matched Sibling Donor Hematopoietic Stem Cell Transplantation for Advanced Stage Sickle Cell Disease: Result of a Pilot Study

IntroductionSickle cell disease (SCD) is an inherited disorder with an estimate of 300.000 affected newborns per year worldwide. Despite significant improvements in preventive measures, supportive care and conventional therapy, substantial morbidity and mortality with a reduced life expectancy persists. Allogeneic hematopoietic stem cell transplantation (HSCT) with a matched sibling donor (MSD) is currently the curative standard of care for SCD patients (pts). But MSD and unrelated matched donor availability is <20% and graft- versus-host disease (GvHD) remains to be associated with significant morbidity and mortality with T cell repleted grafts and standard GvHD prophylaxis, which is unacceptable, particularly in pts with non-malignant diseases. A T cell depleted haploidentical HSCT (T-haplo-SCT) expands donor availability while exhibiting low GvHD rates. In our single center pilot study, we compared T-haplo-SCT with a MSD HSCT in pts with advanced stage SCD, using almost identical transplant conditions except donor source and GvHD prophylaxis.Methods17 pts were transplanted for advanced stage SCD-related complications. Five SCD pts received bone marrow (BM) from a MSD and 12 peripheral blood stem cells (PBSC) from a haploidentical donor. The conditioning regimen for both groups consisted of thiotepa (2x5mg/kg), fludarabine (4x40mg/m2), treosulfan (3x14g/m2) and anti-thymocyte globulin (ATG, Neovii, 3x15mg/kg), given on day -9 to -7 for T-haplo-SCT and on days -3 to -1 for MSD. In addition, Cyclosporine A (CSA) or Tacrolimus and MMF was applied for GvHD prophylaxis. All pts underwent exchange transfusions prior to conditioning and means of fertility preservation. The MSD pts included four females and one male, median age 22 years (range 9 to 25 years). Three suffered from homozygous SCD, two from HbS/ß-thalassemia. The BM graft consisted of a median of 2,2 x 106 CD34+ cells/kg bodyweight, with a A/S in three and a A/A genotype in two donors. In T-haplo-SCT, five were females and seven were males. Median age was 18 yrs (range 3 to 28 yrs). Nine had homozygous SCD, three HbS/ß-thalassemia. The PB grafts consisted of a median of 12,2 x 106 CD34+ cells, 11,2 x 103 CD3+ and 23,3 x 103 CD19+ cells/kg. Haploidentical donors were fully haplotype mismatched relatives (1 mother, 8 fathers, 1 cousin, 1 sister and one step sister). Donor genotype was Hb A/A in one and Hb A/S in all others.ResultsThe median follow-up was 21 months in the MSD group and 26 months in T-haplo-SCT group. The median hospitalization was 38 days for both. The median time to engraftment was faster in T-haplo-SCT versus MSD: 16 versus 23 days for leukocytes, 18 versus 23 days for granulocytes and 11 versus 21 days for thrombocytes. The median T (>500/µl) and B cell recovery (>100/µl) in T-haplo-SCT versus MSD was 115 versus 103 days and 85 versus 140 days, respectively.Two pts in the T-haplo-SCT group developed a stable mixed PB chimerism with no SCD-related complications off immunosuppression. Lineage specific chimerism analyses of red cell precursors (CD235a, glycophorine A) in the BM of these pts showed a complete red cell chimerism. The median HbS level off immunosuppression was comparable in both groups (37-38%). In all 17 pts, the conditioning regimen was well tolerated. Mild veno-occlusive disease (VOD/SOS) was diagnosed in 1 MSD patient and a transient thromboembolic event in one T-haplo-SCT patient. One patient developed a life threatening capillary leak syndrome during ATG treatment and subsequent PRES and was rescued by a switch to everolimus MMF prophylaxis. One patient from the T-haplo-SCT succumbed to a CMV pneumonitis combined with rotavirus gastroenteritis. None of our pts developed a grade III-IV acute GvHD. Five T-haplo-SCT and one MSD patient developed steroid responsive grade I-II acute GvHD. One of five MSD and three of twelve T-haplo-SCT pts developed mild to moderate steroid responsive chronic GvHD, which resolved in the meantime. CMV and EBV reactivations were observed but could be treated with standard of care except one patient mentioned above. One patient after T-haplo-SCT developed BK virus nephritis. All pts are stably engrafted off immunosuppression and free of SCD-related complications.ConclusionsIn our experience T-haplo-SCT with CD3+/CD19+ depleted PBSC is safe and efficient with a very low incidence of GvHD and is at least comparable to MSD HSCT, even for advanced stage SCD pts. DisclosuresCorbacioglu:Jazz Pharmaceuticals: Consultancy, Honoraria.