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In light of the extensive use of tungsten (W) in fusion experimental devices and the importance of hydrogen isotopes permeation, based on the first principle approaches we study the effects of W doping on the formation energies of intrinsic point defects, hydrogen interactions with such defects, and hydrogen diffusion in bulk of α-Al 2 O 3. Our investigation demonstrated that W doping enhances the formation of oxygen and aluminum vacancies (Vo and V Al) in α-Al 2 O 3. In W doping α-Al 2 O 3 , hydrogen primarily exists in the form of Ho− (hydrogenation of the bulk V O 3−) and Hi− (H interstitial) defects, while it hardly occupies V Al. Hydrogen is firmly trapped by Vo with a formation energy −3.35eV, and Hi− diffusion become extremely challenging because W doping significantly raises the Hi− diffusion barrier to 4.44 eV. Our findings indicate that W doping is beneficial for hydrogen permeation resistance in α-Al 2 O 3. • W doping in α-Al 2 O 3 promotes oxygen and aluminum vacancies (Vo and V Al). • Hydrogen is firmly trapped by Vo (formation energy: −3.35eV) and rarely occupies V Al. • Hydrogen exists as Hi− (H interstitial) and Ho− (hydrogenation of bulk V O 3−). • W doping increases the migration barrier for Hi− to 4.44 eV, significantly limiting hydrogen permeation in α-Al 2 O 3. [ABSTRACT FROM AUTHOR]

Exposure to metals, a newly recognized risk factor for cardiovascular disease (CVD), could be related to atherosclerosis progression. The authors hypothesized that higher urinary levels of nonessential (cadmium, tungsten, uranium) and essential (cobalt, copper, zinc) metals previously associated with CVD would be associated with baseline and rate of change of coronary artery calcium (CAC) progression, a subclinical marker of CVD in MESA (Multi-Ethnic Study of Atherosclerosis). We analyzed data from 6,418 MESA participants with spot urinary metal levels at baseline (2000-2002) and 1 to 4 repeated, continuous measures of CAC over a 10-year period. We used linear mixed-effect models to assess the association of baseline urinary metal levels with baseline CAC and cumulative change in CAC over a 10-year period. Urinary metals (μg/g creatinine) and CAC were log transformed. Models were adjusted for baseline sociodemographic factors, estimated glomerular filtration rate, lifestyle factors, and clinical factors. At baseline, the median CAC was 6.3 (Q1-Q3: 0.7-58.2). Comparing the highest to lowest quartile of urinary cadmium, CAC levels were 51% (95% CI: 32%, 74%) higher at baseline and 75% (95% CI: 47%, 107%) higher over the 10-year period. For urinary tungsten, uranium, and cobalt, the corresponding CAC levels over the 10-year period were 45% (95% CI: 23%, 71%), 39% (95% CI: 17%, 64%), and 47% (95% CI: 25%, 74%) higher, respectively, with no difference for models with and without adjustment for clinical factors. For copper and zinc, the corresponding estimates dropped from 55% to 33% and from 85% to 57%, respectively, after adjustment for clinical factors. The associations of metals with CAC were comparable in magnitude to those for classical CVD risk factors. Exposure to metals was generally associated with extent of coronary calcification at baseline and follow-up. These findings support that metals are associated with the progression of atherosclerosis, potentially providing a novel strategy for the prevention and treatment of atherosclerosis progression. [ABSTRACT FROM AUTHOR]

A novel integrated strategy is proposed to construct the LiNi 0.9 Co 0.09 W 0.01 O 2 with simultaneous spinel phase and Li 2 TiO 3 conductive network, which can enhance the lithium-ion migration kinetics and structural stability of ultrahigh-Ni cathode materials. [Display omitted] The tungsten with high oxidation states (W6+) had been proved to effectively improve the electrochemical performance of ultrahigh-nickel (Ni ≥ 90 %) cathode materials due to the unique microstructures. However, the exat location and underlying action mechanism of tungsten are still not well-understood, and there have been no reports on in-situ modification from bulk to surface simultaneously for these novel cathode materials. Here, a novel integrated strategy is proposed for in-situ modification of LiNi 0.9 Co 0.09 W 0.01 O 2 (NCW). Innovatively, the introduction of nano spinel phase and titanium pinned into the lattice further suppresses the anisotropic variation of unit cell and promotes the lithium-ion migration kinetics within the bulk. Additionally, the Li 2 TiO 3 conductive network enhances migration kinetics across interface and protects the active material against electrolyte erosion. Furthermore, the combination of in-situ analysis and DFT calculation reveals the ordered distribution of tungsten and the suppression effects of titanium on phase transition and cobalt redox. Consequently, the titanium-modified NCW exhibits significantly improved electrochemical performance, such as capacity retention of 93.0 % at 1C after 500 cycles in pouch-type full-cell, along with stable lattice oxygen during operation. [ABSTRACT FROM AUTHOR]

Dual-band electrochromic windows have emerged as a promising approach to reduce building energy consumption. However, developing facile and effective method for preparing single-component dual-band electrochromic material remains a challenge. Herein, an in situ carbothermal reduction strategy was utilized to fabricate monoclinic oxygen-deficient tungsten oxide (WO 3-x) for high-performance dual-band electrochromism. Polyvinylpyrrolidone (PVP–K90) underwent transformation into amorphous carbon at high temperature, serving as the reducing agent embedded in the tungsten oxide film, and in situ inducing the formation of oxygen vacancies during annealing treatment. Lastly, the amorphous carbon was gasified without weakening the transmittance of WO 3-x film. The content of oxygen vacancies in WO 3-x could be modulated by controlling the added amount of PVP-K90. The intrinsic generation of oxygen vacancies not only obtained a strong local surface plasmon resonance (LSPR) absorption in near-infrared (NIR) range, but also improved lithium ion (Li+) diffusion in WO 3-x film. The WO 3-x electrochromic film exhibited excellent dual-band electrochromic performance in optical modulation, switching time, coloring efficiency, bistability, and cycle stability. Furthermore, the WO 3-x film was applied to electrochromic window to verify its available regulation in solar illumination and heat, indicating that the designed modification strategy has potential for developing a single-component dual-band electrochromic window with outstanding performance. [ABSTRACT FROM AUTHOR]

Electrochromic (EC) mirrors fabricated using the electrodeposition of metals can dynamically transition between reflective and transparent states via the deposition and dissolution of the employed metals. In particular, the incorporation of an EC counter electrode enables the realization of an absorptive state under optimized applied voltage. Herein, we present reversible EC mirrors composed of Ag and WO 3 layers as the two electrodes, highlighting their EC properties in three optical transformation modes: transparent, reflective, and absorptive. The formation of Ag layers under optimized deposition conditions was confirmed, and the electrodeposited WO 3 layers exhibited compact or porous structures depending on the deposition conditions. The prepared Ag–WO 3 EC mirrors showed substantial transmittance modulation during the reflecting (53.7%) and coloring (63.5%) process. Interestingly, in comparison to the compact WO 3 , the EC mirrors with porous WO 3 layers exhibited dark-gray coloration in the reduced state, which was attributed to the localized surface plasmon resonance effect caused by codeposited Ag particles. [ABSTRACT FROM AUTHOR]

In this study, novel compositionally graded tungsten alloys incorporating ceramics were prepared using mechanical alloying and pressure-assisted vacuum hot press (VHP) sintering. Three distinct tungsten compositions (W1, W2, and W3) were developed with varying alloying elements and reinforcements, were stacked layer-wise, and then sintered using VHP. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were employed to analyze the morphology and microstructural features of synthesized alloys. The effect of alloying elements and reinforcements on mechanical properties and wear behavior was examined. The results showed improvement in mechanical characteristics and enhanced wear resistance of the compositionally graded tungsten alloys. The hardness was increased due to the formation of carbide phases during milling and sintering. The W1 side exhibited a hardness of 8.4 GPa, while the W3 side reached a hardness of 13.3 GPa. Additionally, the wear behavior of both sides (W1 and W3) was also investigated under different applied loads. At a load of 10 N, the W1 surface exhibited a minimum specific wear rate of 3 × 10−6 mm3/Nm, attributed to the presence of MWCNTs and WC phase. However, the W3 surface reinforced with TiC and cBN showed a minimum specific wear rate of 9 × 10−7 mm3/Nm at a higher load of 20 N. This indicates that the W3 side possessed superior hardness and wear resistance ability as compared to the W1 side of compositionally graded tungsten alloys. The novel compositionally graded approach is useful for developing tungsten alloys with tailored mechanical properties for wear resistance applications. [ABSTRACT FROM AUTHOR]

In this work, a series of multiple lanthanide and tungsten co-doped fluorite structured (Bi 2 O 3) 0.95- x (Ho 0.4 Er 0.4 Tm 0.4 Yb 0.4 Lu 0.4 O 3) x (WO 3) 0.05 (x = 0.1, 0.2, 0.3, 0.4) and (Bi 2 O 3) 0.26 (Ho 0.5 Er 0.5 Tm 0.5 Yb 0.5 O 3) 0.48 (WO 3) 0.26 materials were prepared by traditional solid-state reaction method. The phases, stabilities, and electrical properties of these materials were thoroughly studied. The results revealed that under high oxygen partial pressure, CO 2 , or inert atmospheres, all these samples had excellent long term thermal stability and chemical stability, and the samples of (Bi 2 O 3) 0.95- x (Ho 0.4 Er 0.4 Tm 0.4 Yb 0.4 Lu 0.4 O 3) x (WO 3) 0.05 (x = 0.1, 0.2, 0.3, 0.4) with low or mediate configuration entropies showed pure and high oxide ion conductivities, e.g. ∼2.6 × 10−2 S/cm at 600 °C for the sample x = 0.2. Whereas, for the (Bi 2 O 3) 0.26 (Ho 0.5 Er 0.5 Tm 0.5 Yb 0.5 O 3) 0.48 (WO 3) 0.26 sample with high configuration entropy, pure ionic conduction occurred only within a narrow temperature range (700−750 °C) under the N 2 atmosphere. Under strong reducing condition, only the high-entropy sample (Bi 2 O 3) 0.26 (Ho 0.5 Er 0.5 Tm 0.5 Yb 0.5 O 3) 0.48 (WO 3) 0.26 showed high phase and chemical stabilities, but would introduce strong electronic conduction rise from the reduction of the high content W6+. While for (Bi 2 O 3) 0.95- x (Ho 0.4 Er 0.4 Tm 0.4 Yb 0.4 Lu 0.4 O 3) x (WO 3) 0.05 with low or mediate configuration, phase decompositions with impurities of Bi metal and HoH 2 were observed under strong reducing atmosphere, accompany with obviously decreased conductivities. Therefore, we provided here a comprehensive understanding for the multiple components doped Bi 2 O 3 -based materials with configuration entropy from low to high on their phases, stabilities, and electrical properties, and suggested a new strategy for designing and stabilizing bismuth-oxide-based materials. [ABSTRACT FROM AUTHOR]

Nano tungsten carbide (WC) was synthesized using loose yellow tungsten oxide (WO3) rods, which were derived from violet tungsten oxide (WO2.72) through calcination in dry oxygen. The WO3 rods were then subjected to ball milling with carbon black, followed by carbothermal reduction and carbonization. Unlike conventional methods such as hydrogen reduction or carbothermal reduction, this technique avoids the formation of hydrated tungsten oxides and addresses challenges related to precise carbon control and matching. This streamlined procedure produces nanoscale tungsten carbide particles approximately 150 nm in size, showing great potential for future industrial applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • The refractory oxides of the W-residue formed a harmless slag after smelting with SKW. • Photovoltaic sawing waste was applied as a high-efficient silicothermic reductant. • Heavy metal oxides in W-residue were converted into high-value alloy phase. • An overall recovery rate of valuable metals of 91.7% was achieved. • The synergistic recovery mechanism of two industrial wastes was studied. Solid waste challenges in both the tungsten and photovoltaic industries present significant barriers to achieving carbon neutrality. This study introduces an innovative strategy for the efficient extraction of valuable metals from hazardous tungsten leaching residue (W-residue) by leveraging photovoltaic silicon kerf waste (SKW) as a silicothermic reducing agent. W-residue contains 26.2% valuable metal oxides (WO 3 , CoO, Nb 2 O 5 , and Ta 2 O 5) and other refractory oxides (SiO 2 , TiO 2 , etc.), while micron-sized SKW contains 91.9% Si with a surface oxide layer. The impact of SKW addition on the silicothermic reduction process for valuable metal oxides in W-residue was investigated. Incorporating SKW and Na 2 CO 3 flux enables valuable metal oxides from W-residue to be effectively reduced and enriched as a valuable alloy phase, with unreduced refractory oxides forming a harmless slag phase during the Na 2 O-SiO 2 -TiO 2 slag refining process. This process achieved an overall recovery yield of valuable metals of 91.7%, with individual recovery yields of W, Co, and Nb exceeding 90% with the addition of 8 wt.% SKW. This innovative approach not only achieves high-value recovery from W-residue and utilization of SKW but also minimizes environmental impact through an efficient and eco-friendly recycling pathway. The strategy contributes significantly to the establishment of a resource-efficient circular economy, wherein the recovered high-value alloy phase return to the tungsten supply chain, and the harmless slag phase become raw materials for microcrystalline glass production. [ABSTRACT FROM AUTHOR]

As the penetration technology develops and the projectile velocity increases, it becomes imperative to investigate the protection mechanism of high-performance ceramic under hypervelocity impact. The impact process of tungsten alloy projectile penetrated into B 4 C–TiB 2 –SiC composite ceramic target using ballistic test and finite element simulation at an ultra-high velocity of 2154 m/s was researched in the present study. Additionally, the protection mechanisms were described in terms of the morphology of target damage, the behavior of projectile kinetic energy dissipation, and the temperature field cloud. The findings from the ballistic experiments highlighted that the formation of macro-damage areas (concentrated damage, cone crack, circumferential crack, and radial crack areas) and micro-fragmentation zones could consume a significant amount of impact energy. The mixed fracture mode and the typical inelastic deformation characteristics (dislocations and micro-twinning) contributed to the energy dissipation. Simulation results indicated that the surface dwell effect of the projectile exhibited the highest rate of energy consumption. Furthermore, the temperature field results indicated that the maximum temperature on composite ceramic surface could reach 2310 K, which was below the melting point of B 4 C ceramic (2723 K). However, this temperature could cause the melting of the majority of metal materials. Therefore, ceramic materials exhibited a significant advantage under conditions of ultra-high impact velocities. [ABSTRACT FROM AUTHOR]

Developing efficient catalysts for hydrogen (H 2) evolution from ammonia-borane (AB, NH 3 BH 3) is crucial for fuel cell applications. Photocatalytic hydrolysis of AB by heterogeneous catalysts under light irradiation has attracted attention as an effective technique for H 2 evolution. Here, we report an impregnation-reduction method to prepare the tungsten(VI) oxide-supported nickel/silver nanoparticles (denoted as NiAg/WO 3) and their characterization by advanced tools such as ICP-OES, PXRD, SEM, TEM, and XPS. The initial turnover frequency (TOF), activation energy (E a#), activation enthalpy (ΔH#), and activation entropy (ΔS#) values of NiAg/WO 3 nanoparticles in H 2 evolution from AB under visible light irradiation are calculated as 56.6 molH 2 ⋅ molNi 0.27 Ag 0.73 −1 ⋅ min−1, 52.14 kJ ⋅ mol−1, 47.78 kJ ⋅ mol−1, and −91.62 J ⋅ mol−1 ⋅ K−1, respectively. These findings are especially significant for a feasible application of AB in H 2 fuel cells. [Display omitted] • Ni 0.27 Ag 0.73 /WO 3 catalyst was prepared according to the impregnation-reduction method. • Characterization of the Ni 0.27 Ag 0.73 /WO 3 catalyst was performed using advanced analytical methods. • The Ni 0.27 Ag 0.73 /WO 3 catalyst provided an TOF value of 56.6 min−1 in the hydrolysis of AB under visible light irradiation. [ABSTRACT FROM AUTHOR]

Mica is the most important carrier of rare alkalis (Li, Rb and Cs) and volatiles, and also a major host of rare metals such as Sn, W, Nb and Ta. Thus, the knowledge of trace element partitioning between mica and silicate melt is crucial to understand enrichment mechanisms of ore metals in evolved silicic systems. However, experimental data are scarce, mainly because the synthesis of large mica grains which can be analyzed with laser ablation techniques is challenging. To address this issue, we conducted two-step experiments, using a high-temperature step at 800 °C, and a low-temperature step at 600 °C with a temperature cycling interval of 30 °C, and variable run durations from 21 to 60 days. The experimental products, at 600 °C, 200 MPa, are mainly composed of mica and alkali feldspars. Ferroholmquistite (Fhlm; a Li-bearing amphibole) was also observed in the Li-bearing systems. Beryllium, Zn and Cs are highly incompatible in all run products with mineral/melt partitioning of mineral/melt D Be between 0.01 and 0.08, mineral/melt D Zn between < 0.01 and 0.24 and mineral/melt D Cs between <0.01 and 0.19. Gallium is mildly incompatible in mica and feldspars with mica/melt D Ga , K-feld/melt D Ga and Na-feld/melt D Ga of 0.24–0.35, 0.60–0.67 and 0.69–0.72, respectively, whereas Fhlm/melt D Ga is nearly 1. Rubidium is characterized by a slight enrichment in mica and K-rich feldspar with respect to melt. Niobium and Ta are highly incompatible in feldspars, while they are compatible in ferroholmquistite. Li-mica crystallization would cause Nb/Ta fractionation with mica/melt D Nb and mica/melt D Ta of 4.46 and 0.88, respectively. Tungsten is preferentially incorporated in Li-rich mica with mica/melt D W > 22. The strong partitioning of W into Li-rich mica implies that minor Li-rich mica fractionation (>5 %) will strongly deplete W in the residual melt, thus inhibiting transfer to the magmatic fluid at the magmatic-hydrothermal transition. Based on the observed mineral/melt D value, a multi-stage quantitative fractionation model for the behavior of metals during the crystallization of Li-bearing granitic magmas was developed. The results suggest that crystal fractionation is an effective mechanism that could further enrich Be, Ga, Rb, Cs, Nb and Ta in residual melts. Li-rich mica and muscovite are more effective in causing Nb/Ta fractionation as compared with biotite. The very low Nb/Ta ratios found in natural granite may have resulted via extreme, i.e., >99 wt% of fractional crystallization, even if without the precipitation of columbite-group minerals or increasing hydrothermal activity. Due to the very high Li-mica/melt D W value, water saturation in the melt and subsequent magmatic fluid exsolution should occur before Li-mica starts to crystallize to avoid W sequestration in the magma. At 175 MPa, the efficiency of extracting W from Li-poor granitic system is at least 15 % higher than that from Li-rich granitic system. Li-poor granitic systems are thus expected to have a greater W-mineralization potential than Li-rich system, which is consistent with the fact that most parental magmas of large/giant W deposits are Li-poor in composition. [ABSTRACT FROM AUTHOR]

NiFe-based metal-organic frameworks (MOFs) are promising low-cost and easily prepared non-precious catalysts for the oxygen evolution reaction (OER). However, effectively modulating the electronic structures in these electrocatalysts remains a critical challenge. In this study, we successfully incorporated tungsten into FeNi-MOF to synthesize W-doped FeNi 2.4 -MIL-53 and achieved electronic structure modulation. The results show that the optimized FeNi 2.4 W 0.05 -MIL-53 exhibits a lowe overpotential of 235 mV at a current density of 10 mA cm−2, low Tafel slope of 43.3 mV dec−1, and high cyclability over 1000 cycles. Density functional theory (DFT) calculations demonstrate that the conversion from O* to OOH* is the rate-determining step on the active sites of FeNi 2.4 W 0.05 -MIL-53. The incorporation of tungsten induces an upshift of the d-band center of the active site, effectively modulating the adsorption energy of oxygen intermediates, thereby enhancing the catalytic activity. • Incorporation of tungsten into FeNi-MOFs successfully modulates electronic structures. • Optimized catalyst shows lower overpotential and excellent durability. • DFT confirms tungsten's role in enhancing oxygen intermediate adsorption. [ABSTRACT FROM AUTHOR]

Polycrystalline diamond compacts (PDCs) with varying amounts of vanadium were successfully sintered. The mechanical and thermal performance tests showed that the abrasion resistance, impact toughness, and thermal resistance increased by 69%, 202.9%, and 30 °C, respectively. The improved performance can be attributed to the solid solution formed by V 8 C 7 with tungsten carbide (WC) as a reinforcing phase, which eliminated interfacial defects, improved residual stress, and reduced the thermal expansion coefficient. In summary, we successfully developed a novel method for fabricating high-performance PDCs to enhance abrasion resistance and thermal stability, while substantially improving impact resistance, and which have remarkable application prospects. [ABSTRACT FROM AUTHOR]

Sodium tungsten bronzes (Na x WO 3) are reduced metal oxides with applications in nanoparticle plasmonics. Despite decades of research, little is known about the conditions under which they can corrode. Here, Na x WO 3 nanoparticles were exposed to high-humidity air for 71 days to induce corrosion. The samples were studied ex-situ by using X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The low-Na sample (x = 0.4) corroded slowly into a single, insulating, hydrated Na–W– O –N phase over 10 weeks. The high-Na sample (x = 0.7) fully corroded after only 4 weeks, decomposing into at least 3 corrosion products, including the phase observed in the low-Na sample. Despite the complex corrosion process, the corrosion rate of both samples was reasonably well-described by a first-order rate equation, allowing for straightforward estimation of the corrosion kinetics. Although the corrosion phases could not be unambiguously determined, the EDS and XRD data suggests that the phases are hydrated, sodiated tungstates which appear to contain N. These findings help clarify the conditions under which the tungsten bronzes can corrode and are important for designing applications which use tungsten bronze nanoparticles. [ABSTRACT FROM AUTHOR]

The sluggish kinetics of the oxygen evolution reaction (OER) is generally undesirable for advanced green hydrogen production through renewable energy unless the employment of efficient catalysts. Perovskite-type oxide materials have been recognized as promising alternatives to overcome the kinetic limitations of OER. Nonetheless, despite extensive research endeavors, the electrochemical activity and durability of versatile perovskite candidates still fall short of expectations. Herein, a novel perovskite cobaltite BaCo 0.6 Fe 0.2 W 0.2 O 3-δ (BCFW0.2), enlightened by tungsten incorporation strategy, is proposed as a reliable electrocatalyst for OER. Characterization analyses unravel that the manipulation of tungsten substitution in BCFW0.2 leads to the formation of high-symmetry crystal structure and more reactive oxygen species, which in turn promotes favorable oxygen catalytic behavior. Accordingly, the BCFW0.2 catalyst exhibits significantly lower overpotential of 273 mV at a current density of 10 mA cm−2 and remarkably smaller Tafel slope of 42.34 mV dec−1 relative to its un-doped counterpart, as well as considerable operational durability under various current densities. The mechanism of lattice oxygen activation in BCFW0.2 is also explored. This study paves a constructive avenue for the rational design of high-performance perovskite-based derivative catalysts. [Display omitted] • A novel single-hexagonal perovskite electrocatalyst BaCo 0.6 Fe 0.2 W 0.2 O 3-δ (BCFW0.2) is well-developed. • Tungsten substitution contributes to formation of high-symmetry crystal structure and more reactive oxygen species. • BCFW0.2 achieves exceptional activity and durability for water oxidation, significantly surpassing pristine BCF counterpart. • Oxygen evolution mechanism of BCFW0.2 is probably associated with the LOM pathway. [ABSTRACT FROM AUTHOR]

Tungsten iron-oxide zeolite composites with different Fe and W loadings were synthesized over NaY zeolite supports using a wet impregnation method. The composites exhibited suitable textural properties, light absorption, redox sites and acidity for photocatalytic VOC degradation. The photocatalytic activity for degrading acetaldehyde and o-xylene VOCs emitted from rubber powder modified asphalt was evaluated under solar irradiation. The 5Fe-10 W-NaY(2.8) composite achieved the highest VOC removal of 80% for acetaldehyde and 76% for o-xylene after 6 hours. Increasing Fe and W loading up to 5 wt% and 10 wt%, respectively, significantly enhanced the VOC degradation efficiency. Higher zeolite content and stronger acidity also boosted the photocatalytic performance. The degradation occurred via redox mechanisms involving photo-generated electrons, holes and reactive oxygen species, facilitated by the zeolite acid sites. The 5Fe-10 W-NaY(2.8) composite exhibited good stability over 5 reuse cycles, indicating its potential for mitigating VOC emissions from rubber powder modified asphalt pavements. [ABSTRACT FROM AUTHOR]

Tungsten (W) stable isotope data for twenty-four composites made from the fine-grained matrix of glacial diamictites, deposited between the Mesoarchean and the Paleozoic, as well as two Archean tonalite-trondhjemite-granodiorites (TTG) are used to refine the W isotope compositions (expressed as δ186W deviations from the NIST 3163 W standard) of the upper continental crust (UCC). To do this we evaluate W isotope fractionation in the diamictites as the result of both magmatic and low-temperature processes. The δ186W values of the diamictites are heterogeneous (0.017 ± 0.011 ‰, 2SE to 0.182 ± 0.007 ‰, 2SE), encompassing the range of previously published values for igneous rocks. We find that δ186W correlates positively with the diamictite's chemical index of alteration (CIA), a measure of the degree of chemical weathering in the provenance, suggesting that the continental regolith (i.e., surface material composed of weathered residues) is isotopically heavy for W. Since W in rivers and ocean water is also isotopically heavy, this suggests that equilibration with Fe-Mn-oxides controls the W isotope composition of surface waters and that such oxides are not important constituents of the regolith, whose W is likely accommodated in clays. Using diamictites with low CIA (<60, n = 9), we calculate an average δ186W of 0.046 ± 0.036 ‰ (2SD) for the UCC, from 2.3 to 0.3 Ga. This average is combined with the TTG data of this study, as well as data from the literature for upper crustal rocks to obtain a representative δ186W value of the UCC of 0.046 ± 0.046 ‰ (2SD). The W stable isotope composition of the UCC is lighter than that of mantle-derived melts (MORB and OIB, with an average δ186W = 0.082 ± 0.026 ‰, 2SD), and much lighter than the weighted average δ186W of intra-oceanic arcs (δ186W = 0.104 ± 0.052 ‰, 2SD), though the spread in the arc rocks is large. The significant difference in δ186W between average intra-oceanic island arc lavas and UCC is intriguing given that continental crust is thought to form primarily via arc magmatism. This difference suggests that not all modern intra-oceanic arcs are representative of those that formed the continental crust. Rather, only arcs that are enriched in incompatible trace elements, which also tend to have lighter W isotope compositions, may have been involved in making new continental crust. Alternatively, there may have been a secular change in the W isotope composition of arc magmas. [ABSTRACT FROM AUTHOR]

In this paper, WO 3 with specific exposed facets was prepared through hydrothermal method, then Pt nanoparticles were decorated on the surface of WO 3 to enhance the H 2 dissociation ability, and the obtained Pt/WO 3 materials could realize the visualized H 2 detection by the rapid color change of powder. In specific, the high exposure of oxygen ion at c-axis and the shortened diameter of (001) crystal facets is helpful for achieving fast coloring-blenching process. As a result, WO 3 nanowires could exhibit a reflectance change of 86.2%, rapid coloring time (64 s) and recovery rate compared with nanorods and microspheres. Moreover, the detailed influencing mechanism of morphology on diffusion and injection of H and O atoms during gasochromism was revealed. This study could contribute to deepen the understanding of morphology-dependent hydrogen gasochromic performance from microscopic view. • Pt decorated WO 3 hydrogen gasochromic materials with different morphologies were prepared. • The morphology discrepancy of WO 3 resulted in differentiated gasochromic performance. • Enhancing the exposure of O2− at c axis could improve gasochormic performance of WO 3. • The mechanism of morphology-dependent hydrogen gasochromic performance was explored. [ABSTRACT FROM AUTHOR]

Electrocatalytic full water splitting is still a challenge. Porous single-crystalline (PSC) has a long-range ordered crystal structure and large specific surface area, which has great potential to be applied in the fields of catalysis and energy storage. Nitride single-crystalline possesses unsaturated coordination of metal-nitrogen active sites on the crystal surface, which has shown excellent performance in the electrocatalytic field. PSC tungsten nitride mesoporous nanosheets are grown from single-crystalline (SC) WO 3 nanosheets and are applied as bifunctional electrocatalysts in Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER). The overpotential of mesoporous W 2 N and WN single-crystalline nanosheets in HER is as low as 67.44 mV and 84.26 mV at a current density of 10 mA cm−2, respectively. A low overpotential has been found in PSC W 2 N and WN as the OER electrocatalyst. The PSC tungsten nitride mesoporous nanosheets provide a simple and effective solution for efficient water splitting electrocatalysts. [Display omitted] • Porous tungsten nitride single-crystalline nanosheets synthesized for the first time. • Porous single-crystalline W 2 N possesses large specific surface area. • Porous single-crystalline W 2 N has excellent HER performance. • Porous single-crystalline shows outstanding long-term durability at HER and OER. [ABSTRACT FROM AUTHOR]

This study investigates hydrogen diffusion in tungsten at high temperatures using molecular dynamics simulations. It explores the effect of different hydrogen concentrations on diffusion mechanisms, the interaction of hydrogen atoms with vacancy defects, and their impact on the mechanical properties of tungsten. The activation energy for hydrogen diffusion in perfect bulk tungsten with 0.1 % hydrogen concentration is calculated as 0.235 eV, with a diffusion pre-exponential factor of 5.336 × 10-8 m2/s at temperatures ranging from 1000 to 3000 K. The investigation reveals two factors contributing to the increase in activation energy with temperature: migration paths involving TIS-TIS and TIS-OIS-TIS pathways, and an increase in migration energy. Three diffusion regimes are identified, with trapping effects dominating at temperatures below 1500 K, TIS-TIS pathway dominating at intermediate temperatures, and TIS-OIS-TIS pathway becoming more prominent at higher temperatures. Increasing hydrogen concentration up to 2 % (H/W concentrations in fusion environments) has minimal effect on diffusion in perfect tungsten. However, in a W-H-V system with a 1 % vacancy defect, increasing hydrogen concentration increases the effective diffusion coefficient and activation energy. The presence of hydrogen atoms and vacancy defects reduces the tensile strength and elastic modulus of tungsten, with hydrogen atoms having a greater impact on mechanical properties compared to vacancies. The degree of reduction in mechanical properties is proportional to the concentration of hydrogen atoms and vacancy defects. • The hydrogen diffusion in tungsten at high temperatures was studied using molecular dynamics. • The study explores the effect of different hydrogen concentrations on diffusion mechanisms. • The impact of hydrogen interaction with vacancy on the mechanical properties of tungsten was studied. • The investigation reveals two factors contributing to the increase in activation energy with temperature. • The presence of hydrogen atoms and vacancy defects reduces the tensile strength and elastic modulus of tungsten. [ABSTRACT FROM AUTHOR]

The equilibrium isotope effect (EIE) of hydrogen isotopes (H and D) on the W electrode in alkaline aqueous (H 2 O) and heavy water (D 2 O) solutions was empirically studied based on the relevant electrochemical adsorption isotherms, which were determined using the phase-shift method and electrochemical impedance spectra. For a fractional surface coverage range of 0.2 < θ < 0.8, the potential differences (Δ E) for hydrogen isotope adsorptions on the W electrode were 70 mV, which were much lower than those on the Ni, Ti, Pd, and Rh electrodes. Furthermore, the value of EIE on the W electrode was 13.4, significantly higher than that on the Ti and most Pt-group metal (Pt, Ir, Pt–Ir alloy, and Rh) electrodes. The W electrode can therefore be considered as a potential electrocatalyst for optimizing the hydrogen and deuterium evolution reactions (HER and DER) and EIE of hydrogen isotopes, particularly in water electrolysis and the hydrogen isotope effect. [Display omitted] • Frumkin isotherms and equilibrium isotope effect (EIE) of H to D on W. • EIE on W is much higher than that on Ti, Pt, Ir, Pt–Ir alloy, and Rh. • Potential difference (Δ E) at coverage range (0.2 < θ < 0.8) on W. • Δ E (0.2 < θ < 0.8) on W is much lower than that on Ni, Ti, Pd, and Rh. • W can be a potential electrocatalyst for optimizing water electrolysis and EIE. [ABSTRACT FROM AUTHOR]

Porphyry-type ore deposits are closely associated with subduction zones, but the ultimate source of the metals in these deposits is still uncertain. To test whether aqueous fluids from the subducted slab may contribute to the metal enrichment, we investigated the partitioning of Cu, Zn, Mo, and W between saline aqueous fluids and the subducted basaltic crust at 2.5–3.0 GPa and 650–670 °C by experiments in piston cylinder presses. The bulk fluid/solid partition coefficients (Dfluid/solid) of Cu and Zn increase significantly with fluid salinity. For Cu, Dfluid/solid is less than 1 in a salt-free aqueous fluid, but at a salinity of 10 wt% NaCl, Dfluid/solid approaches 10. On the other hand, the Dfluid/solid of Zn is still below 0.4 even at the same salinity. Dfluid/solid of Mo is always relatively high (>4), with only a very slight enhancement by salinity at 2.5 GPa. The fluid/solid partition coefficient of W is close to 1 for a chloride-free fluid, but slightly decrease with increasing salinity. Overall, these experimental data show that saline aqueous fluids released from the basaltic layer of the subducted oceanic slab can effectively transport Cu and Mo and therefore enrich these two metals in the mantle wedge. This enrichment does not contradict the observation that Cu concentrations in primitive arc magmas and MORB are similar, since these concentrations may be controlled by a buffering sulfide phase. The enrichment of copper in the source then does not necessarily increase Cu concentrations in the melt, but it ensures that the copper-bearing sulfide phase is not exhausted during repeated melting events. For molybdenum, our data suggest that aqueous fluids from the slab are the major source of Mo in arc magmas. Due to the high pre-enrichment of Mo in some sediments, there may be a direct link between the types of subducted sediment and the location of porphyry Mo deposits. On the other hand, the contribution of slab fluids to the Zn budget of these magmas is likely negligible. The W partitioning data are consistent with isotopic evidence for the mobility of W in subduction fluids. Moreover, the behavior of Mo and W is strongly affected by the abundance of rutile in the solid residue. In a rutile-free lithology, not only Mo, but also W would strongly partition into the fluid. As some sediments may be highly enriched in W relative to the average mantle, fluids from such sediments may also produce a significant W enrichment in the mantle wedge, provided that the sedimentary residue is free of rutile. [ABSTRACT FROM AUTHOR]

Hydrogen, a carbon-neutral and renewable energy resource, is alternative to the diminishing conventional fossil fuels energy. However, developing pollution-free electrocatalysts for hydrogen evolution reaction (HER) is desirable but remains a challenge. Herein, a novel nanohybrid consisting of tungsten doped RuP 2 nanoparticles (NPs) anchored on the carbon dots (W 0.15 -RuP 2 @CDs 1.0) has been developed for wide-pH HER. Due to the strong coordination interactions between the metal ions and the surface functional groups of CDs, the dispersion improvement of W doping RuP 2 NPs is achieved. Meanwhile, CDs form the N-rich self-crosslinking structures that accelerates electron transfer during the reaction. Moreover, the W dopant optimizes the electronic configuration, leading to faster proton shift and hydrogen diffusion. Beneficially, the optimized W 0.15 -RuP 2 @CDs 1.0 achieves 10 mA cm at low overpotentials of 19 mV (0.5 M H 2 SO 4) and 28 mV (1.0 M KOH) with an excellent stability. This study provides an innovative idea to design the high-performance non-platinum catalysts. [Display omitted] • A novel W 0.15 -RuP 2 @CDs 1.0 nanohybrid has been developed for wide-pH HER. • The dispersion improvement of W doping RuP 2 NPs is achieved by complexing with CDs. • The W 0.15 -RuP 2 @CDs 1.0 achieves excellent HER activity in acidic and alkaline media. • The W 0.15 -RuP 2 @CDs 1.0 possesses outstanding catalytic stability over 40 h. [ABSTRACT FROM AUTHOR]

In this study, leached graphite coin decorated with tungsten oxide nanoparticles and carbon nanotubes (leached tungsten oxide/carbon nanotubes-graphite coin) with high surface area and excellent mechanical strength is introduced as a novel and low-cost electrode in the supercapacitor application. The leached tungsten oxide/carbon nanotubes-graphite coin was easily fabricated via uniform addition of commercial Zinc-metal powder into the matrix of commercial graphite powder and carbon nanotubes powder, pressing under optimized pressure followed by treatment in H 2 SO 4 solution for leaching out of Zinc from carbon nanotubes-graphite matrix and finally electrodeposition of tungsten oxide nanoparticles onto the previously leached coin. The surface chemistry and structure features of the leached coin were investigated by FTIR, RAMAN, XRD, SEM, TEM, AFM and BET analysis. The leached tungsten oxide/carbon nanotubes-graphite coin had acceptable capacitive characteristic such as negligible ohmic drop and favorite specific capacitance of 3519 mF cm−2 at 2 mA cm−2 in aqueous 1.0 M H 2 SO 4 media. After assembling a symmetric supercapacitor coin-device including leached tungsten oxide/carbon nanotubes-graphite coin in a PVA/H 2 SO 4 gel, the coin-device shows a high specific capacitance of 283 mF cm−2 at the current density of 2.5 mA cm−2. [Display omitted] • Simple, inexpensive and scalable fabrication of leached graphite coin was reported. • Leached graphite coin was decorated by tungsten oxide nanoparticles and carbon nanotubes. • The modified coin showed negligible ohmic drop and favorite specific capacitance of 3519 mF cm−2 at 2 mA cm−2. • Symmetric supercapacitor coin-device showed high cell voltage of 2 V as well as a high specific capacitance. [ABSTRACT FROM AUTHOR]

Proton exchange membrane water electrolysis (PEMWE) exhibits the superior benefits including high gas purity, high power density and wide variable loading but is still limited by the prohibitive cost and dearth of iridium (Ir)-based anode catalysts. Herein, we report a low-loading Ir-based catalyst with ultrasmall iridium nanoparticles (1.46 ± 0.01 nm) supported on oxygen-vacancy-rich tungsten oxide nanofibers (WO 3-x) through electrospinning combined with surfactant-free microwave-assisted polyol reduction method for active acidic oxygen evolution reaction (OER). According to structural analysis and theoretical calculation, the charge transfer from W to Ir is induced by the strong electronic interaction at the Ir and WO 3-x interface, thereby raising the electron density surrounding the Ir sites and favoring to boost OER activity. The resultant Ir@WO 3-x exhibits an excellent overpotential of ca. 276 mV@10 mA cm−2 and remarkable durability. This study offers a new path for promoting the activity and durability of electrocatalysts while minimizing the mass loading of Ir towards OER. Oxygen-rich-vacancy WO 3-x nanofibers induce the deposition of ultrafine Ir nanoparticles to efficiently enhance acidic oxygen evolution reaction in water electrolysis. [Display omitted] • Ir@WO 3-x nanofibers is designed via electrospinning combined with surfactant-free microwave-assisted polyol reduction method. • Ir@WO 3-x nanofibers is rich in oxygen vacancies. • The charge transfer is induced by the strong metal support interaction at the Ir and WO 3-x interface. • Ir@WO 3-x nanofibers exhibits the enhanced oxygen evolution reaction activity. [ABSTRACT FROM AUTHOR]

Hydrogen (H 2) is a clean and sustainable energy source, and it plays an integral part in lowering the world's reliance on fossil fuels. H 2 evolution by the electrocatalytic reduction of water is a key step toward protecting the environment, and the development of cost-effective electrocatalysts is required for the production of huge quantities. In this article, metal (Tungsten)-doped molybdenum selenide (MoSe 2) electrocatalysts for the hydrogen evolution process are proposed. MoSe 2 activity in the hydrogen evolution process not only promotes the (selenium) Se vacancies and generation of phase shift from 2H to 1T but also optimizes the electronic structure of the material, which is favorable for hydrogen adsorption. Compared to pure P–MoSe 2 , engineered V–WMoSe 2 nanosheets exhibit a low overpotential of ∼247 mV at a current density of 10 mA cm−2 and a lowered Tafel slope and decent turnover frequency (TOF). This technology not only explains the process behind the enhanced hydrogen evolution capabilities but also provides low-cost and effective Mo-based electrocatalysts by stimulating metal cations. [Display omitted] • Metal (Tungsten)-doped molybdenum selenide (MoSe 2) electrocatalysts for the hydrogen evolution was successfully fabricated. • MoSe 2 activity in the hydrogen evolution process is increased as a result of the incorporation of tungsten. • V–WMoSe 2 serve as a potential electrocatalysts for the hydrogen evolution process. • In comparison to pure P–MoSe 2 , modified V–WMoSe 2 nanosheets exhibit a low overpotential of ∼247 mV. [ABSTRACT FROM AUTHOR]

In this work, synthesis of WO 3 nanoparticles is reported using a novel, yet simplified microwave-metal discharge approach. The discharge was triggered from the pointed tip of a tungsten electrode, which eventually got vaporized and deposited on the collector substrates surrounding the metallic electrode. The buildup of high electric field at the tip of the tungsten electrode ionized the surrounding air molecules that lead to the discharge formation. X-Ray diffraction revealed monoclinic phase of the synthesized WO 3 nanoparticles. The morphological analysis executed using transmission electron microscopy showed the presence of single crystalline nanoparticles in spherical, rhombic, and rectangular shapes. X-ray photoelectron spectroscopy confirmed the elemental composition and showed formation of stoichiometric WO 3. Thermal stability analysis showed high stability of the nanoparticles below 1200 °C. The nitrogen absorption-desorption studies suggested that the nanoparticles exhibited a mesoporous structure. The antimicrobial susceptibility tests indicated an increased resistance towards Gram-negative bacteria (E. coli) compared to Gram-positive bacteria (S. aureus). [Display omitted] [ABSTRACT FROM AUTHOR]

Nanofluid rheology and heat transfer were lately the subjects of several research and investigations. In this paper, an experimental investigation was used to investigate the influence of temperature and volume fraction of nanoparticles on dynamic viscosity (µ nf) of WO 3 -Multi-Walled Carbon Nanotubes (MWCNT)-SiO 2 / water-EG ternary hybrid nanofluids. The impacts of these factors were also evaluated on mono nanofluids. The nanofluids were made using a two-step process at solid volume fractions of nanoparticles (SVF) of 0.2 to 0.6% and temperatures ranging from T = 20 to 60 °C. The zeta-potential test was used to measure the stability of nanofluids. According to the obtained results, the nanofluids have high qualities. A Brookfield viscometer was used to measure the µ nf. All volume fractions of nanoparticles show that µ nf decreases with temperature rise. At all temperatures, the µ nf increases as the SVF increase, regardless of temperature. The results showed that in ternary nanofluids the highest amount of viscosity is related to the SVF = 0.6% and the T = 20 °C, which shows a value of 79.7% increase compared to the base fluid at the same temperature. Also, among mono nanofluids, the highest amounts of viscosity were observed for MWCNT at all temperatures and volume fractions. Finally, a mathematical model for calculating the µ nf is established. The results of the proposed models were well correlated with laboratory data. The results of the established model show an acceptable correlation with experimental data. [ABSTRACT FROM AUTHOR]

In the current paper, we have studied the impact of microwave (2.45 GHz) plasma treatment of submicronic (250–600 nm) tungsten dust, upon tritium gas retention. Herein, the conducted experiments have emphasized the role of dust treatments in pure hydrogen gas versus hydrogen plasma, before the tritiation process at different pressures. The obtained tritiated dust was analyzed via room temperature desorption and dissolutions. Additionally, Scanning Electron Microscopy and X-ray Photoelectron Spectroscopy analyses were performed to observe the changes induced by the plasma discharge. The results have shown that the Specific Surface Area of dust is enhanced by using microwave hydrogen plasma treatments, resulting in a high tritium gas retention inside the submicronic tungsten dust. [Display omitted] • We studied the 3H retention in W submicronic dust. • One compared 3H retention in untreated/plasma-treated dust. • Microwave plasma dust treatment enhanced 3H retention. [ABSTRACT FROM AUTHOR]

Solid rocket propellants that demonstrate variable burning rates are highly desirable in various propulsion applications. Electrically controlled solid propellants (ECSPs) are one such kind that ignite and combust only when external electric power is applied, which enables to adjust/control their combustion rates. However, the knowledge on their combustion mechanisms is scant in the limited literature. In this study, pyroelectric combustion behaviour of metallized ECSPs, based on lithium perchlorate (LP) and poly vinyl alcohol (PVA), containing 5%, 10%, and 15% tungsten (W) are investigated, in comparison to the non-metallized baseline propellant. Theoretical performance parameters, heat release and mass loss from decomposition process, and combustion rates are obtained. Pyroelectric combustion of ECSPs involves electrolytic decomposition of LP producing oxidizer species, which react with fuel species from PVA and/or W in thermochemical reactions, to generate heat and products including LiCl, HCl, LiOH, WO 3 , etc. Results indicate that addition of W reduces the theoretical adiabatic combustion temperature and overall heat release from exothermic decomposition by 19% and 36% respectively, in ECSP-M15 containing 15% W, compared to the baseline case. However, relatively low voltage response time for metallized ECSPs implies that their ionic conductivity is higher than the baseline ECSP. More importantly, combustion rates of all ECSPs increase exponentially with increase in applied initial voltage in the 100–500 V range. Inclusion of W enhances the combustion rates significantly by 4.9 times at 100 V and by 1.7 times at 500 V for ECSP-M15 relative to the baseline propellant. This signifies that electrochemical mechanisms become the rate controlling step at high electric power, in governing the pyroelectric combustion behaviour of ECSPs. Further, these propellants were successfully tested for multiple burn/no-burn conditions under the application/removal of the external electric power, which is highly desirable for various propulsion systems. [ABSTRACT FROM AUTHOR]

Demand for electrical energy storage (EES) is growing, necessitating the development of improved batteries. Inorganic glassy materials are a class of essential electrodes due of their excellent conductivity and stable structures, they are appropriate for both cathode and anode applications. The most important characteristics that determine the dynamic behavior and rate performance of batteries are the ionic and electronic conductivities of active materials. In this sense, many crystalline, vitreous, and glass ceramics are investigated for their electrical properties. To create uniformly mixed glasses within the xLi 2 WO 4 –(50–x)Li 2 O–40P 2 O 5 –10B 2 O 3 system, the melt-quenching technique is employed. Glasses containing up to 50 mol% Li 2 WO 4 are synthesized with a substantial region of glass formation. They are homogeneous, transparent, and bubble-free. The structural approach and selected physical parameters of these glasses, such as density, molar volume, electrical conductivity, and glass transition temperature, are evaluated. The study emphasizes that an increase in the Li 2 WO 4 amount leads to an elevation in both the density (ρ) and molar volume (Vm). Infrared spectroscopy identifies the presence of numerous structural units within the glass framework. Electrical conductivity measurements of the glasses are investigated using impedance spectroscopy. The measurements are taken over a wide frequency range of 10 Hz to 1 MHz and across temperatures ranging from 303K to 403K. It is highlighted that the electric conductivity rises as the Li 2 WO 4 content is added. The glass with x = 30 mol% exhibits a dc conductivity of 8.63 × 10−7 (Ω−1 cm−1) at room temperature and 8.90 × 10−5 (Ω−1 cm−1) at 150°C. To gain insight into the conductivity relaxation mechanism, the frequency dependence of the glasses' conductivity is investigated. The results indicate that the ion transport in the glasses is governed by the correlated barrier hopping mechanism, which follows Jonscher's power behavior. The scaling conductivity spectra reveal that the conduction mechanism in the glasses is influenced by both temperature and composition. [ABSTRACT FROM AUTHOR]

Hydrogen isotope retention of tungsten in nuclear fusion reactors is one of the hot research issues all along. In this paper, tungsten samples in different rolled surfaces were polished by mechanical processing, subsequently subjected to D 2 + irradiation and thermal desorption. To better understand the experimental observations, this study also performed molecular dynamics (MD) simulation and investigated the effects of temperature, grain number, grain boundary density, and crystal orientation on hydrogen retention. It is found that the grain number and grain boundary density of rolled tungsten increase successively in RD/TD, RD/ND, and TD/ND surfaces. The RD/ND surface exhibits the best hydrogen radiation resistance, whereas the TD/ND surface is unsatisfactory. MD simulations further indicate that hydrogen retention is more obvious with the increase of grain density in tungsten, and hydrogen atoms are more easily enriched at the grain boundaries. With the increase in temperature, the retention of hydrogen atoms in monocrystalline/polycrystalline tungsten decreases significantly. The average implantation depth of H atoms is deepest along the <111> and <112> crystalline directions, which reveals that hydrogen retention is dependent on the crystal orientations. The good agreement between the experimental data and simulation results reveals that grain boundaries play an important role in hydrogen retention. [Display omitted] • The hydrogen retention behavior is studied in W samples with different rolled surfaces. • RD/ND surface has the best hydrogen resistance, while the TD/ND surface is undesirable. • The hydrogen retention behavior depends on temperature, grain size, grain boundary density and orientation. [ABSTRACT FROM AUTHOR]

Deposition of tungsten in methane atmosphere was performed using a low energy plasma focus device. The resulting compounds were synthesized and investigated during the deposition process. Carbon-rich contamination was identified as an organic viscous liquid crystal defect. Tungsten carbide (W 2 C) and dark-black oxygen-deficient tungsten trioxide (WO 3-x) thin films were synthesized by plasma focus device using different number of focused shots. The synthesis of each thin film, which was dependent upon operation of plasma focus device was verified and discussed. Tungsten carbide W 2 C was synthesized during the deposition process while the dark-black WO 3-x was created after the deposition process in atmosphere. All compounds were investigated by spectroscopy, crystalline, and microscopy methods. Nano indentation test disclosed higher value of hardness for the film containing tungsten carbide compound (10.01 GPa) compared to both pure tungsten (5.72 GPa) and the dark-black WO 3-x thin film (6.83 GPa). The verified band gap energy of dark-black WO 3-x was around 1.475 eV. [ABSTRACT FROM AUTHOR]

The current work is interested in the preparation, characterization, and mechanical-optical properties of the glasses in the (75-x)B 2 O 3 –10SrO–8TeO 2 –7ZnO−xWO 3 system, with (x = 0 (BSTZW0), 1 (BSTZW1), 5 (BSTZW2), 10 (BSTZW3), 22 (BSTZW4), 27 (BSTZW5), 34 (BSTZW6), and 40 mol% (BSTZW7). The preparation of the glasses has involved the melt-quenching route. The new glasses are characterized by different characterization techniques using densimeter, microhardness, Raman spectroscopy, UV–visible absorption and emission, and X-ray diffraction. Photoluminescence can determine the impact of substituting B 2 O 3 with WO 3 on the mechanical-optical parameters and the structure of the present glasses. The prepared samples' X-ray patterns showed amorphous states. The density value rises from 2.88 to 4.50 g/cm3, with the amount of WO 3 rising from 0 to 40 mol% as a result of the difference in molecular weight between WO 3 and B 2 O 3. The Vickers microhardness (Hv) rises as the amount of WO 3 increases as a result of a decrease in free volume and the formation of covalent bonds. The elastic moduli were found to increase when the WO 3 concentrations increased from 0 to 40 mol%. This increase depends on the formation of bridging oxygen atoms. The Raman bands are designed to correspond to the bonds that form the structure of the current glass and detect the insertion of WO 3 content by the attribution of the new W–O–W and W–O bonds. The UV–Visible spectroscopy analysis showed no band characteristic for the reduced species of W5+ ions identified by dark blue. However, the photoluminescence spectra showed emission bands (under excitation at 300 nm) that are associated with the active centers of W4+, W5+, and W6+ ions. [ABSTRACT FROM AUTHOR]

Syngas production via dry reforming of methane was conducted over 5 wt%Ni + xWO 3 /γ-Al 2 O 3 (x = 1, 3, 5, 7, or 9 wt%) catalysts at 700 °C and ambient pressure for 7.5 h in a tubular fixed-bed reactor. Textural, morphological, and catalytic properties were investigated in relation to the weight percent of tungsten trioxide loading. The physicochemical properties of the catalysts were evaluated using XRD, N 2 -physisorption, TGA, H 2 -TPR, CO 2 -TPD, NH 3 -TPD, SEM, EDX, and Raman techniques. N 2 -physisorption analysis showed that tungsten trioxide promoter had a minor impact on the textural properties upon varying its weight percentage loading. With increasing tungsten trioxide loading, the total amount of reducible NiO-interacting species was increased over the catalyst surface. 5Ni+5WO 3 /γ-Al 2 O 3 catalyst showed stable 79% CH 4 conversions and 83% CO 2 conversion with the lowest carbon deposition due to the presence of stable metallic Ni species (derived from reducible NiAl 2 O 4 and NiWOAl), the highly acidic sites, and moderate basic sites. [Display omitted] • Promoting nickel-supported on mesoporous γ-alumina with tungsten trioxide. • The optimum weight percent loading of tungsten trioxide: 5.0 wt%. • Enhancement of coke deposition resistance by tungsten trioxide loading. • Reduction of nickel interaction with mesoporous γ-alumina by tungsten trioxide. • Superior catalytic performance of 5Ni+5WO 3 /γ-Al 2 O 3 with 83% CO 2 conversion. [ABSTRACT FROM AUTHOR]

Plasma focus devices generate discharges with dense hot plasma (HP) flows and fast ion streams (FIS) with energies up to several MeV, enabling their use to test materials for nuclear fusion applications. Tungsten plates were exposed to deuterium and to mixed deuterium-helium plasmas at distinct power flux densities at the large PF-1000U device. Elemental modifications as the induced deuterium retention and co-deposition of impurities at the target surfaces were studied by scanning electron microscopy and, particularly, by ion beam analysis (IBA). The results evidence that typically, deuterium retention is enhanced during the first discharges and may decreases afterwards due to surface erosion. Additionally, by adding helium to the working gas to generate the plasmas, deuterium retention increase. Similar results may be achieved by decreasing incident flux densities. The experiment highlights the role of the use of IBA to quantify elemental modifications imposed by irradiation of materials in plasma focus facilities. [ABSTRACT FROM AUTHOR]

Epidemiological studies have established that exposure to tungsten increases the risk of developing cardiovascular diseases. However, no studies have investigated how tungsten affects cardiac function or the development of cardiovascular disease. Inhalation of tungsten particulates is relevant in occupational settings, and inhalation of particulate matter has a known causative role in driving cardiovascular disease. This study examined if acute inhalation to tungsten particulates affects cardiac function and leads to heart tissue alterations. Female BALB/c mice were exposed to Filtered Air or 1.5 ± 0.23 mg/m3 tungsten particles, using a whole-body inhalation chamber, 4 times over the course of two weeks. Inhalation exposure resulted in mild pulmonary inflammation characterized by an increased percentage and number of macrophages and metabolomic changes in the lungs. Cardiac output was significantly decreased in the tungsten-exposed group. Additionally, A′, an indicator of the amount of work required by the atria to fill the heart was elevated. Cardiac gene expression analysis revealed, tungsten exposure increased expression of pro-inflammatory cytokines, markers of remodeling and fibrosis, and oxidative stress genes. These data strongly suggest exposure to tungsten results in cardiac injury characterized by early signs of diastolic dysfunction. Functional findings are in parallel, demonstrating cardiac oxidative stress, inflammation, and early fibrotic changes. Tungsten accumulation data would suggest these cardiac changes are driven by systemic consequences of pulmonary damage. • Inhalation of tungsten particulates results in mild inflammation and metabolomic changes in the lungs. • Inhalation of tungsten results in early signs of cardiac injury (decreased cardiac output and increased atrial workload). • Tungsten increases expression of pro-inflammatory, cardiac remodeling, and oxidative stress genes in the heart. • Tungsten accumulation data would suggest these cardiac changes are driven by systemic consequences of pulmonary damage. [ABSTRACT FROM AUTHOR]

Co-reduction of lanthanum and nickel ions on inert tungsten and active nickel electrodes were studied using the methods of cyclic chronovoltammetry, chronopotentiometry and open circuit chronopotentiometry in equimolar KCl–NaCl at 973 K. When both lanthanum and nickel ions are present in equimolar KCl–NaCl, the voltammetry dependences demonstrate the nickel ions reduction wave in the region of potentials –(0.00–0.1) V and lanthanum ions reduction wave in the region of potentials –(1.85–1.9) V relative to a silver chloride reference electrode. There are two more reduction waves on the opposite sides of voltammograms in the regions of potentials –(1.5–1.6) V and –(1.75–1.8) V. These waves are associated with the reduction of lanthanum ions and their depolarization on metallic nickel preliminarily deposited on the tungsten electrode, which results in the formation of intermetallic La x Ni y phases. The (E–t) dependences of open circuit chronopotentiometry demonstrate a delay plateau, which corresponds to the time required for dissolution of separate phases of intermetallic compounds. LaNi 2 and LaNi 5 intermetallic phases were electrochemically synthesized at a definite concentration of lanthanum and nickel chlorides in equimolar KCl–NaCl. The synthesized lanthanum and nickel intermetallic compounds were characterized by the X-ray diffraction analysis, scanning electron microscopy and photon correlation spectroscopy. • Co-reduction of La3+ and Ni2+ has been first performed in equimolar KCl–NaCl. • La x Ni y is synthesized under kinetic regime due to difference in La and Ni deposition potentials. • La x Ni y intermetallic phases can be synthesized by potentiostatic electrolysis. [ABSTRACT FROM AUTHOR]

By modeling particle trajectories in solids, channeling was studied for the D-W and H-Au cases at energies below 100 keV. It was found that, at energies above 1 keV, a component associated with the channeling of particles in the crystal appears in the spatial distribution of implanted atoms. After passing a distance of about 1000 Å at the particle energy of 100 keV, a stable spatial structure of the beam of particles trapped in the channel is observed, which persists until passing a distance of 0.9 from the particle range. An experiment is proposed to use this phenomenon to obtain information about the potential distribution in the channel, the crystal structure, and the electronic stopping of channeled particles. A difference was observed in the resulting spatial structure for the D-W and H-Au cases due to the difference in the target crystal structure and interaction potential. [ABSTRACT FROM AUTHOR]

Using tailings to prepare constructive materials is of great significance for sustainable development of mineral processing industry. In this study, the possibility of preparing tungsten tailing-based geopolymers was explored in detail. XRD, FTIR, PLM, SEM and XPS analyses were carried out to characterize the phase composition, chemical bonding, microstructure, chemical state, and interface properties of tungsten tailing-based geopolymers. Results showed tungsten tailings presented little activity using NaOH as activator, while geopolymers with 60% non-pretreatment tungsten tailing and 40% metakaolin presented a 3-day compressive strength of 8.4 MPa and 28-day compressive strength of 9.1 MPa. The geopolymerization products of tungsten tailing-based geopolymers were N-A-S-H gels and aluminosilicate zeolite crystals, while tungsten tailings were wrapped by metakaolin-derived geopolymerization phases as aggregates with interfaces containing Si–O–Si bonding between quartz in tungsten tailings and zeolite and/or gel phase in metakaolin-derived geopolymer in the geopolymerization process. Besides, the leaching test results indicated that the immobilization efficiency of T6M4 geopolymers for Mn and Pb derived from tungsten tailings reached up to 97.28% and 99.95%, respectively. This research results provide a new idea for utilization of tungsten tailings on a large scale. [ABSTRACT FROM AUTHOR]

Isotope dilution W whole-rock data, coupled with data for other trace elements in 42 peridotite xenoliths from Tariat (Mongolia), Yangyuan and Hannuoba (China), and Letlhakane (Botswana) are used to constrain the W abundance and behavior in the continental lithospheric mantle. Tungsten concentrations are >11 ng g−1, even in the most depleted peridotites, and higher than the W abundance estimate of the bulk silicate Earth (BSE) in all but one sample. Combined W-Th-U systematics reveal fractionation of W from Th and U with increasing degree of melt depletion, while incompatible element-enriched samples display no such fractionation. Integrated melt reactions and degrees of melt depletion are estimated based on either residual Th or residual Yb abundances for each sample, relative to a BSE precursor. This allows modelling of different partial melting scenarios that consider maximized trace element retention (Th-based model; where measured Th contents are decoupled from Al 2 O 3 contents) or correction for metasomatic trace element contributions (Yb-based model; where measured Yb contents are well-coupled with Al 2 O 3 contents). Modelled residual W concentrations reveal W excesses of 11–19 ng g−1, even when correcting for metasomatic W contributions. Combined with available in situ trace element mineral data for the rock-forming silicates and spinel, which all display W abundances much higher than expected, these findings suggest that either (i) W is less incompatible than previously thought, or that (ii) the peridotites experienced W metasomatism after the last melt depletion event with subsequent re-equilibration. The latter is unlikely, as similar geochemical patterns are observed for oceanic lithospheric mantle based on published data, requiring such W metasomatism to be a global phenomenon. We thus conclude that W is not as incompatible as Th and U during upper mantle melting and potential W-Th-U fractionation mechanisms are examined to explain near-constant W/Th and W/U in mantle melts. We propose revised W concentrations for the BSE of 27 ± 16 ng g−1 to 31 ± 14 ng g−1 and for the depleted mantle of 22 ± 13 ng g−1. [ABSTRACT FROM AUTHOR]

Prefilled syringes are widely used as a primary container for therapeutic proteins because they are more convenient than glass vials. The stability of biologic molecules can be affected by different syringe materials and techniques, such as silicone oil levels and coating method, amount of tungsten remaining in the glass barrel after using a tungsten pin to create the needle hole, and end of the syringe, which can be Luer locked or pre-staked with a needle. We investigated the impact of these parameters by using a monoclonal antibody to collect the antibody's stability profile and the prefilled syringes' functionality data. Silicone oil levels had no impact on aggregation levels, and particle counts were lowest for silicone oil–free syringes. Functionality performance was similar and did not change throughout all stability time points for all syringe configurations. The break-loose force for Ompi syringes was initially lower and increased over time to align with those of the other configurations, all of which remained well below 25 N. Tungsten contaminants and agitation stress from shipping studies did not impact quality attributes. This work can help guide the development of similar products in prefilled syringes to ensure selection of the primary container that provides adequate stability for the protein, as well as maintain the desired functionality features over the shelf life of the drug product. [ABSTRACT FROM AUTHOR]

• We conducted an experiment to measure activation cross sections of alpha-particle-induced reactions on natural tungsten. • The stacked-foil activation technique and high-resolution gamma-ray spectrometry were used for the measurement. • Production cross sections of 185,183m,183g,182gOs and 188g,186g,184g,183g,182g,181Re were determined up to 50 MeV. • The results were compared with the previous experimental data and the TENDL-2019 values. We measured activation cross sections of alpha-particle-induced reactions on natural tungsten targets. The stacked-foil activation technique and gamma-ray spectrometry were used. Production cross sections of 185,183m,183g,182gOs and 188g,186g,184g,183g,182g,181Re were determined. The results were compared with experimental literature data and the TENDL-2019 and TENDL-2021 values. The cross sections of the most reactions were determined for the first time. [ABSTRACT FROM AUTHOR]

The exploration of high-efficiency and stable electrocatalysts for alkaline and seawater hydrogen evolution reaction (HER) is the key to realize energy conversion, but there is still a significant challenge owing to the slow HER kinetics in alkaline and seawater systems. In this study, we prepared nickel foamed-supported Ru, W co-doped NiSe 2 (Ru, W–NiSe 2 /NF) by a brief two-step hydrothermal strategy and the prepared Ru, W–NiSe 2 /NF displays exceptional HER property, requiring only a low overpotential of 100 and 353 mV to reach 10 mA cm−2 in 1 M KOH and natural seawater, respectively, far superior to Ru–NiSe 2 /NF, W–NiSe 2 /NF and NiSe 2 /NF. Electrochemical surface area (ECSA) and operando electrochemical impedance spectroscopy (EIS) verify the abundant active sites and superior electron transfer rate of Ru, W–NiSe 2 , which optimized the HER kinetics in alkaline solution and natural seawater. The ECSA normalization and TOF results indicated that Ru, W co-doping increased the intrinsic activity of NiSe 2. This study revealed the impact of bimetallic doping on the intrinsic activity of NiSe 2 , and provided a practical strategy for designing and developing the HER electrocatalysts with excellent performance. • Ru, W co-doped NiSe 2 on nickel foam were synthesized by a two-step hydrothermal method. • Ru, W co-doping increases the active area, enhances the conductivity, and greatly improves its intrinsic activity. • The Ru, W–NiSe 2 /NF exhibited greatly enhanced hydrogen evolution activity in alkaline and natural seawater. [ABSTRACT FROM AUTHOR]