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In this study, the Ba 3 P 2 O 8 and Mg 2 B 2 O 5 were fabricated by the solid-state reaction method separately, and the (1-x)Ba 3 P 2 O 8 -xMg 2 B 2 O 5 (x = 0.2–0.4) low-temperature co-fired ceramic (LTCC) materials were obtained in the sintering temperature range of 880–960 °C. The phase compositions, microstructures, elemental compositions, and microwave dielectric properties of the (1-x)Ba 3 P 2 O 8 -xMg 2 B 2 O 5 composite ceramics were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and TE 01δ mode dielectric resonator method, respectively. The results revealed that the Mg 2 B 2 O 5 phase and Ba 3 P 2 O 8 phase could coexist well in the (1-x)Ba 3 P 2 O 8 -xMg 2 B 2 O 5 composite ceramics without formation of any new phases. The abnormal grain growth of Ba 3 P 2 O 8 grains was inhibited by the addition of Mg 2 B 2 O 5. In addition, through composition of Ba 3 P 2 O 8 and Mg 2 B 2 O 5 , the temperature coefficient of resonant frequency (τ f) and quality factor (Q×f) were effectively optimized, and the sintering temperature was reduced to 880–960 °C. The optimal performance of 0.8Ba 3 P 2 O 8 -0.2Mg 2 B 2 O 5 composite ceramic was achieved at a sintering temperature of 920 °C, τ f = −1.9 ppm/°C, Q×f = 61,250 GHz, and a low permittivity ε r = 10.7. The chemical compatibility test demonstrated that the composite ceramic could coexist well with silver, which indicated that the 0.8Ba 3 P 2 O 8 -0.2Mg 2 B 2 O 5 composite ceramic is a candidate LTCC material with wide application prospects. [ABSTRACT FROM AUTHOR]

The purpose of this research is to examine the effects of the economic complexity index and its square, investments in the energy sector, green technological innovation, and the growth of the industrial structure in 32 provinces in China on carbon dioxide emissions from 2005 to 2019. Modern methods that consider cross-sectional dependency, unit root test, co-integration test, IFE estimation, and one- and two-step generalized method of moments (GMM) models were used in the econometric analysis. The results showed that the economic complexity index is to blame for the worsening trends in China's carbon dioxide emissions. In contrast, we find that the economic complexity index square, investments in renewable energy, green technical innovation, and industrial structure all help to reduce carbon dioxide emissions, which is helpful for China's carbon-abatement goals. Carbon emissions are negatively affected by renewable energy's limited effect on green technology innovation and industrial structure. Based on these findings, a number of policy suggestions are offered. • This study uses the innovative determinants of sustainable development. • This study uses the IFE and series of GMM Estimators. • Industrial sector, GTI and REI rises the level of sustainable development. • There exists an inverted U-shaped EKC-hypothesis. • Moderate role of REI significantly improves the level of environment. [ABSTRACT FROM AUTHOR]

To constrain the behavior of K isotopes during granitic magmatic differentiation, we present high-precision K isotope data for bulk granitoids and their K-bearing minerals from Dabie and Himalayan orogens in China. Plagioclase displays extremely large K isotopic variation, with δ41K ranging from −0.56 to 1.91‰. Other minerals also have heterogeneous K isotopic compositions, with δ41K varying from −0.56 to −0.24‰ in hornblende, from −0.72 to −0.39‰ in biotite, from −0.79 to −0.47‰ in K-feldspar, and from −0.74 to −0.61‰ in muscovite. The general trend of 41K enrichment follows the order of plagioclase ≫ hornblende > biotite ≈ K-feldspar ≥ muscovite, which can be attributed to the difference in K O bond strengths. Both δ41K of plagioclase and K isotope fractionation factors between plagioclase and other minerals are negatively correlated with K concentration in plagioclase, suggesting a compositional control on isotope fractionations. Inter-mineral K isotope fractionations among other minerals are roughly temperature-dependent. Potassium isotopic compositions of whole rocks display measurable variations (δ41K = –0.69 to −0.28‰), which are correlated with proxies for plagioclase fractionation (e.g., Sr and Rb/Sr). The correlation indicates that fractional crystallization may account for the whole-rock K isotopic variations observed in high-silica igneous rocks, which is supported by modeling of fractional crystallization using the apparent isotope fractionation factors determined in this work. Our study demonstrates the existence of large K isotope fractionation during granitic magmatism, making K isotopes a potential tool for studying differentiation of felsic magmas. [ABSTRACT FROM AUTHOR]

Knowledge of the behavior of magnesium (Mg) isotopes during magmatic differentiation is a prerequisite for applying Mg isotopes as a tracer of crustal recycling and mantle heterogeneity. Crystal fractionation of mafic silicate minerals leads to limited Mg isotope fractionation; hence, Mg isotopic variations in basalts largely result from contributions of subducted crustal materials into their mantle sources. However, recent studies have revealed that the segregation of iron oxides, such as chromite during early-stage basaltic differentiation and titanomagnetite and ilmenite during late-stage differentiation, can potentially modify Mg isotopic compositions of mantle-derived lavas. Titanomagnetite is much more commonly observed in terrestrial basaltic lavas than chromite and ilmenite, and can also form during early-stage basaltic differentiation. To constrain the effects of titanomagnetite crystallization on Mg isotopic systematics of basaltic magma, we report Mg isotopic data for a suite of well-characterized alkaline basaltic lavas (MgO wt% = 4.99 to 6.52) from Gerba Guracha, western Ethiopian Plateau, which have undergone extensive titanomagnetite fractionation. Their δ26Mg values range from −0.29‰ to −0.17‰ and do not correlate with indicators of titanomagnetite fractionation such as TiO 2 and V. These observations suggest that the segregation of titanomagnetite produced limited Mg isotope fractionation, possibly because of its composition-dependent, highly variable Δ26Mg Ti-Mgt−melt (Δ26Mg Ti-Mgt−melt = δ26Mg Ti-Mgt − δ26Mg melt) values. Considering that most iron oxides occur as complex solid solutions that are controlled by the oxygen fugacity of magmas, the effects of oxide segregation on Mg isotopic systematics of basalts require further evaluation. • Alkaline basaltic lavas from Gerba Guracha display limited Mg isotopic variations. • The δ26Mg values do not correlate with indicators of titanomagnetite fractionation. • Titanomagnetite fractionation has produced limited Mg isotope fractionation. [ABSTRACT FROM AUTHOR]

1. The Ir a Hf b Al c alloy thin films were deposited by Direct Current Magnetron Sputtering (DC-MS). 2. We for the first time prepared Ir a Hf b Al c alloy thin films with a preferred (111) orientation substitution solid solution, which have the advantages of mechanical properties and oxidation resistance. 3. The mechanical properties of the Ir a Hf b Al c alloy films were significantly improved over the previous ones, with maximum hardness (H) and modulus of elasticity (E) exceeding 20 GPa and 330 GPa, respectively. 4. The catalytic activity of Ir in Ir a Hf b Al c films is effectively reduced. The volatilization temperature of the films is increased and the overall oxidation resistance is substantially improved. [Display omitted] • The Ir a Hf b Al c alloy thin films with a preferred (111) orientation substitution solid solution were first prepared by us for the first time. It has the advantages of mechanical properties and oxidation resistance. • The mechanical properties of the Ir a Hf b Al c alloy films were significantly improved over the previous ones. The minimum surface roughness (Ra) value of the IraHfbAlc alloy films was 0.7 nm, while the maximum hardness (H) and elastic modulus (E) exceeded 20 GPa and 330 GPa, respectively. • The oxidized volatility of the Ir in the films was only 0.11 μm/h at 1300 °C (lower than most of the previously reported values, such as 0.5 μm/h). The oxidation rate was slowed down by 50 % compared to the previous one, which greatly improved the lifetime of the film. • Moreover, the modified Ir a Hf b Al c alloy thin films reduce the catalytic activity of Ir metal, reduces the thermal effect and increases the volatilization temperature. • Detailed analysis of microscopic phenomena reveals the presence of crystal-like order (CLO) in thin films, solving the mystery of improved oxidation resistance and mechanical properties. Improving oxidation resistance has long been a challenge for hot end components in high temperature environments. We have fabricated a series of Ir a Hf b Al c (at. %) alloy thin films by multi-targeted direct current magnetron sputtering (DC-MS) and have thoroughly investigated the microscopic mechanism of the films. More importantly, we for the first time prepared Ir a Hf b Al c alloy thin films with a preferred (111) orientation substitution solid solution, which exhibits excellent mechanical properties and oxidation resistance. The minimum surface roughness (R a) value of the Ir a Hf b Al c alloy films was 0.7 nm, while the maximum hardness (H) and elastic modulus (E) exceeded 20 GPa and 330 GPa, respectively. The oxidized volatility of the Ir in the films was only 0.11 μm/h at 1300 °C (lower than most previously reported values, such as 0.5 μm/h), which greatly improved the lifetime of the film. Confirmation that lattice distortion induces the refinement of crystal-like order (CLO) in thin films, and solves the mystery of enhanced oxidation resistance. The findings provide important insights into the design of Ir-containing alloy coatings and offer new ideas in the field of high-temperature protection. [ABSTRACT FROM AUTHOR]

[Display omitted] • GO/PANI nanocomplex electrode with high biocompatibility was fabricated. • GO/PANI@CP electrode showed 54 times of power density compared to blank CP. • Bacteria on electrode surface showed fast electron release and uptake. • Efficient bio-denitrification in cathode was developed via GO/PANI@CP electrode. Bidirectional electron transfer is about that exoelectrogens produce bioelectricity via extracellular electron transfer at anode and drive cytoplasmic biochemical reactions via extracellular electron uptake at cathode. The key factor to determine above bioelectrochemical performances is the electron transfer efficiency under biocompatible abiotic/biotic interface. Here, a graphene/polyaniline (GO/PANI) nanocomposite electrode specially interfacing exoelectrogens (Shewanella loihica) and augmenting bidirectional electron transfer was conducted by in-situ electrochemical modification on carbon paper (CP). Impressively, the GO/PANI@CP electrode tremendously improved the performance of exoelectrogens at anode for wastewater treatment and bioelectricity generation (about 54 folds increase of power density compared to blank CP electrode). The bacteria on electrode surface not only showed fast electron release but also exhibited high electricity density of extracellular electron uptake through the proposed direct electron transfer pathway. Thus, the cathode applications of microbial electrosynthesis and bio-denitrification were developed via GO/PANI@CP electrode, which assisted the close contact between microbial outer-membrane cytochromes and nanocomposite electrode for efficient nitrate removal (0.333 mM/h). Overall, nanocomposite modified electrode with biocompatible interfaces has great potential to enhance bioelectrochemical reactions with exoelectrogens. [ABSTRACT FROM AUTHOR]

[Display omitted] • A biohydrogel electrode containing nanosheets and Shewanella was farbicated. • Biohydrogel was modified into photoanode with thylakoid membrane. • Photoanode produced maximum photocurrent 126 μA/cm3 under visible light. • 5.4 mM butyrate was yield from CO 2 bio-reduction in photoelectrochemical cell. Bio-photoelectrochemical cell (BPEC) is an emerging technology that can convert the solar energy into electricity or chemicals. However, traditional BPEC depending on abiotic electrodes is challenging for microbial/enzymatic catalysis because of the inefficient electron exchange. Here, electroactive bacteria (Shewanella loihica PV-4) were used to reduce graphene oxide (rGO) nanosheets and produce co-assembled rGO/ Shewanella biohydrogel as a basic electrode. By adsorbing chlorophyll contained thylakoid membrane, this biohydrogel was fabricated as a photoanode that delivered maximum photocurrent 126 μA/cm3 under visible light. Impressively, the biohydrogel could be served as a cathode in BPEC by forming coculture system with genetically edited Clostridium ljungdahlii. Under illumination, the BPEC with above photoanode and cathode yielded ∼ 5.4 mM butyrate from CO 2 reduction, 169 % increase compared to dark process. This work provided a new strategy (nanotechnology combined with synthetic biology) to achieve efficient bioelectricity and valuable chemical production in PBEC. [ABSTRACT FROM AUTHOR]

Self-healable hydrogels have attracted significant interests in the fields of environmental protection, oil plugging and electronic sensors, etc. Benefiting from the synergistic contribution of hydrogen bonding and ligand chelation, in this work, we prepared a series of self-healable hydrogels via a simple and inexpensive approach, which overcame the limitations of the intrinsic nature of dynamic covalent bonds and non-covalent interactions under harsh conditions. Systematic study of the effect of temperature, salt concentration and particle size on the physicochemical performance of the re-crosslinking progress revealed that re-crosslinked gels using particles of 0.20–0.28 mm (in a solution with salt concentration of 10%) at 130 °C presented an elastic modulus of 62 Pa at a frequency of 10 Hz and remained elastic after 45 days of aging (elastic modulus: 18,170 Pa). Of particular interest, gel particles with a particle size of 0.125–0.28 mm can be reassembled at temperatures up to 150 °C or salt concentrations up to 20%, which is superior to a plethora of previous reports (self-healing temperature usually less than 130 °C, salt concentration <10%). Employment of the green inexpensive sodium D-gluconate instead of partial acrylamide makes the gel product a promising candidate material for oil plugging, targeting fractured reservoirs for consistent control. [Display omitted] • Self-healable hydrogels were fabricated in a simple and inexpensive method. • Hydrogels were capable of re-crosslinking at harsh conditions. • Chelation of metal ions and hydrogen bonds contributed to the re-crosslinking process. • This re-crosslinkable hydrogel is a promising candidate for oil plugging. [ABSTRACT FROM AUTHOR]

Protein compartments are distinct structures assembled in living cells via self-assembly or phase separation of specific proteins. Significant efforts have been made to discover their molecular structures and formation mechanisms, as well as their fundamental roles in spatiotemporal control of cellular metabolism. Here, we review the design and construction of synthetic protein compartments for spatial organization of target metabolic pathways toward increased efficiency and specificity. In particular, we highlight the compartmentalization strategies and recent examples to speed up desirable metabolic reactions, to reduce the accumulation of toxic metabolic intermediates, and to switch competing metabolic pathways. We also identify the most important challenges that need to be addressed for exploitation of these designer compartments as a versatile toolkit in metabolic reprogramming. • Compartment formation driven by protein self-assembly or phase transition. • Pathway enzymes can be directed into compartments for metabolic engineering. • Membraneless compartments enable dynamic control of metabolic pathways. • Synthetic protein compartments enable spatial control of cellular metabolism. [ABSTRACT FROM AUTHOR]

• Magnesium isotopic compositions are reported of magnetite in layered mafic intrusions for the first time. • Large Mg isotopic variation in magnetite is primarily governed by subsolidus processes. • Magnesium isotopic compositions of magnetite are related to mineral proportions in the cumulates. • Primitive Mg isotopic signature of coexisting Fe–Ti oxides indicates early crystallization in origin. To constrain the mechanisms governing the extremely large variations of Mg and Fe isotopes in magmatic Fe–Ti oxides in layered mafic intrusions, we investigate Mg isotopic compositions of magnetite, coupled with its chemical data and whole-rock major element and Sr-Nd isotope compositions from the Baima layered mafic intrusion in the Emeishan large igneous province, SW China. The Baima intrusion is mainly composed of magnetite-wehrlite and magnetite-troctolite (i.e., oxide-rich rocks) in the Lower Zone, and troctolite and gabbro (i.e., oxide-barren rocks) in the Middle and Upper Zones. Magnetite separates display large Mg isotopic variation, with δ26Mg ranging from −0.17 ± 0.06 to +0.58 ± 0.04‰ in the oxide-rich rocks and from −0.18 ± 0.06 to +0.98 ± 0.04‰ in the oxide-barren ones. The lack of correlation of δ26Mg with trace elements in magnetite and whole-rock Sr-Nd isotopic compositions indicates that the large Mg isotopic variation in magnetite was not produced by fractional crystallization, magma mixing, crustal contamination, and/or trapped liquid shift. Instead, equilibrium isotope fractionation induced by Mg–Fe re-equilibration between magnetite and ilmenite at different subsolidus temperatures controlled the Mg isotopic variation in the oxide-rich rocks; and kinetic isotope fractionation driven by Mg–Fe inter-diffusion between magnetite and olivine and/or clinopyroxene dominated the oxide-barren rocks. Both processes were primarily controlled by the assemblage and modal abundance of coexisting minerals to which magnetite adjoins. Overall, fractional crystallization and subsequent subsolidus diffusion played crucial roles in the genesis of the Fe–Ti oxides in the Baima intrusion. Our results also reveal widespread isotope disequilibrium between coexisting minerals in mafic magma chambers and suggest that Mg isotope geochemistry has a great potential to characterize the formation of Fe–Ti oxides in layered mafic intrusions. [ABSTRACT FROM AUTHOR]

Arc magmas derived from mantle melting often have trace element and isotopic signatures that indicate crustal contributions. The origin and extent of crustal contributions are critical constraints for quantifying crust-mantle recycling at subduction zones; however, it is difficult to distinguish between inputs from the downgoing oceanic slabs and that of the over-riding arc crust. Here we present a novel study using stable potassium (K) isotopes to fingerprint the long-debated crustal signatures in lavas from Martinique Island, Lesser Antilles arc. We find δ41K of Martinique lavas varies from −0.66 to 0.01‰ and correlates with chemical parameters and radiogenic isotope ratios. These correlations cannot be produced by assimilation of arc crust during magma ascent. Rather, they reflect mantle sources that have been modified by the input of subducted sediments. Most lavas display a strong negative correlation between δ41K and radiogenic isotopic compositions, from typical mantle values of −0.37‰ to much lower values of −0.66‰, suggesting the addition of <1% to 5% subducted sediments to their mantle sources. Notable divergence in this correlation occurs for three samples with variably high δ41K (−0.28 to 0.01‰), which is likely caused by the addition of isotopically heavy K-bearing fluids derived from slab dehydration. Our study indicates that a substantial fraction of large ion lithophile elements, including K in arc magmas and thus nascent crust, is inherited from subducted crust; K isotopes are useful tracers of this cycling process. [ABSTRACT FROM AUTHOR]

Lignocellulosic nanofibril (LCNF) is indispensable in numerous potential applications because of its unsurpassed quintessential characteristics. While it still remains a challenge to assemble LCNF in a facile and environmental economy-first manner. In this work, a simple and green one-step synthetic approach was reported to prepare a series of LCNF-containing versatile hydrogels using deep eutectic solvent (DES). In particular, the LCNF5% hydrogel (namely LCNF5%-gel) in this work perfectly integrated superior stretchability (∼643 %), and displayed a dramatically improved anti-swelling ability (25 %) compared to the control sample (neat DES hydrogel, 2252 %). Simultaneously, the LCNF5% hydrogel presented underwater adhesiveness and outstanding long-term low-temperature resistance (stable at −25 °C for a month). This novel multifunctional hydrogel, prepared by a facile and eco-friendly strategy, is potentially useful in wet adhesion or underwater applications. • Lignocellulose nanofibril was used to prepare multifunctional hydrogels. • This hydrogel was prepared with a one-step approach using deep eutectic solvent. • The hydrogel presented good anti-swelling and long-term low-temperature resistance. • The product can be potentially useful in wet adhesion or underwater applications. [ABSTRACT FROM AUTHOR]

The REBa 2 Cu 3 O x (REBCO) tape, known for its exceptional mechanical properties, stands as an optimal conductor for high-field applications. Nevertheless, stress degradation attributed to the membrane and monofilament structure of REBCO tape often occurs in high-field REBCO coils. On the other hand, iron-based superconductor (IBS) tapes offer notable advantages, including multifilament structure and upper critical field above 150 T, rendering it an appealing choice for high magnetic field applications. In this context, we first propose a methodology for designing a new type of compact hybrid magnet that integrates REBCO coils with multifilament IBS coils and a water-cooled resistive magnet to generate a high magnetic field. This paper presents the preliminary design of a hybrid magnet and employs a numerical simulation model to assess the magnet's electromagnetic and mechanical configuration, the simulation results show that the stress and strain experienced by all coils is within safe limits. Furthermore, details of the fabrication and testing of the IBS-REBCO joint are also provided. We hoped that the resistance of the IBS-REBCO joint would be less than 50 nΩ, however the resistance of the joint we developed did not meet our expectations. We discuss the reasons and propose the next plan to improve the performance of the IBS-REBCO joint. [ABSTRACT FROM AUTHOR]

Marine ecosystem recovery after the latest Permian mass extinction (LPME) was a protracted process during the Early Triassic (∼252–247 Ma) owing to repeated climatic and environmental perturbations. Chemical weathering can supply nutrients to the ocean and may have played an important role in the Early Triassic carbon cycle and biological recovery. However, only limited geochemical records of chemical weathering during the Early Triassic have been presented to date, and the relationship between changes in weathering intensity and the slow recovery of marine ecosystems is effectively unknown. Here, we report magnesium (Mg) isotopic compositions of the siliciclastic components from shallow-marine carbonates in two well-studied Upper Permian-Lower Triassic sections in Iran and South China to track changes in chemical weathering intensity after the LPME. Both sections display a wide range of δ26Mg values (−2.09‰ to +1.10‰ at Zal, −2.30‰ to +0.33‰ at Zuodeng). We identified two distinct stages (I and II) in each section based on δ26Mg values and major elemental ratios. Variations of δ26Mg values in Stage I (Changhsingian to mid-Dienerian) are mainly controlled by mineralogical composition that can obscure weathering signals. By contrast, δ26Mg variations in Stage II (upper Dienerian to upper Spathian) are independent of lithology and inferred to reflect control by chemical weathering intensity. The trends in chemical weathering intensity within Stage II correspond to first-order variations in climate and carbon cycling. Marine ecosystem recovery during the Early Triassic may have been linked to recurrent episodes of intense chemical weathering caused by CO 2 degassing and climate warming. This study demonstrates the potential utility of the Mg isotopic compositions of the silicate fraction in marine carbonates as a proxy for chemical weathering intensity, laying the groundwork for general applications of this method to deep-time Earth systems. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) isotopes in carbonate minerals are a useful proxy for paleoclimate studies, but interpretations are often limited by an inadequate understanding of the various factors controlling Mg isotopic fractionation during carbonate formation. Previous work has studied a number of parameters including aqueous chemistry, mineralogy, temperature, and precipitation rate. However, little is known about the impact of solid/solution ratio, calcite growth mechanism, and crystal morphology on isotope fractionation. In this work, two groups of seeded chemo-stat calcite precipitation experiments were conducted at 25 °C to explore the potential impact of crystal growth and morphology on the fractionation of Mg isotopes. Group-1 experiments (G1) contained nine individual runs that were performed under identical physicochemical conditions, except for solid/solution ratio and the length of an experiment. The isotope fractionation between precipitated calcite and aqueous solution is limited, with Δ26Mg cal-sol ranging from −2.58 to −2.40‰ and an average of −2.49 ± 0.12‰ (2SD, n = 9). The Group-2 experiments (G2) contained 3 paired runs with solution Mg/Ca molar ratios of 0.5, 2.0, and 5.0, and yielded Δ26Mg cal-sol values that ranged from −2.69 to −2.36‰ with an average of −2.62 ± 0.25‰ (2SD, n = 6). The average Δ26Mg cal-sol value for both sets of experiments is −2.54 ± 0.22‰ (2SD, n = 15), and it is independent of precipitation rate, solution Mg/Ca molar ratio, solid/solution ratio, amount of overgrowth, and mol% Mg content in overgrowth. The form and texture of the calcite overgrowths in our experiments range from {104} rhombohedra with smooth crystal faces containing few macrosteps to {104} rhombohedra containing extensive evidence for 2-D nucleation on crystal faces, to more steeply sided rhombohedra {0 kl }. While significant changes in crystal morphology are related to solid/solution ratio and solution composition in the G1 and G2 experiments, respectively, there was no difference in Mg isotope systematics, suggesting that crystal morphology does not affect the Mg isotopic composition of calcite within the range of features investigated and 2-D nucleation may be less affected by calcite growth kinetics than a spiral growth mechanism. Integrating our results with previous published values, an equilibrium isotopic fractionation factor of −2.47 ± 0.09‰ (weighted average ± weighted 2SD, n = 70) between calcite and aqueous solutions is derived at room temperature. [ABSTRACT FROM AUTHOR]

Potassium isotopic compositions of profiles through saprolites developed on a diabase in South Carolina, U.S.A., and on a granite in Guangdong, China, allow characterization of the behavior of K isotopes during continental weathering. Saprolites from the diabase profile are heavily weathered with chemical index of alteration (CIA) values up to 95; however, their K isotopic variation is limited, with δ41K ranging from −0.475 ± 0.028‰ in the unweathered diabase to −0.407 ± 0.021‰ for the saprolites. The lack of significant K isotope fractionation mainly reflects the conservative behavior of K in the diabase weathering profile, with >50% of the original K remaining in the saprolites. By contrast, K isotopes are fractionated during granite weathering and correlate with sample depth, CIA, and kaolinite abundance, with δ41K decreasing from −0.493 ± 0.030‰ in the unweathered granites at the bottom to −0.628 ± 0.021‰ in the most weathered saprolite close to the surface. These observations suggest the preference of light K isotopes in saprolites relative to fluids, which is further supported by the overall isotopically heavy nearby stream water samples (δ41K = −0.709 ± 0.017 to −0.339 ± 0.018‰). These results demonstrate that continental weathering plays an important role in the global K isotopic budget through the formation of isotopically heterogeneous rivers and weathered regolith. Recycling of K-rich crustal materials with distinct K isotopic signatures may produce distinct mantle K isotopic end members. [ABSTRACT FROM AUTHOR]

Continental crust loses Mg by lower crustal foundering and chemical weathering to become its intermediate-silicic composition. Both processes should preferentially retain heavy Mg isotopes in the crust, yet the estimated Mg isotopic ratio for the bulk continental crust is indistinguishable from that for unmodified mantle. This can be elucidated by two notions that are not mutually exclusive: (i) the basaltic parent to the crust has Mg isotopes lighter than the mantle and has since become mantle-like as a result of Mg loss by igneous and weathering fractionation, and (ii) heavy Mg isotopes in the continental crust are constantly balanced by a hidden input of light Mg isotopes. Arc magmas are arguably building blocks of the continental crust and their Mg isotopic signature could be used to place limits on the above views. Here, we conducted a Mg isotopic study of the Makran arc, a rare continental arc in Iran within the Alpine-Himalayan orogenic belt. The measured Mg isotopic ratios for most mafic and intermediate samples are mantle-like with δ26Mg values ranging from −0.32‰ to −0.20‰. After excluding dubious samples affected by alteration, the silicic samples span a broad range of isotopic ratios with δ26Mg values ranging from −0.32‰ to +0.32‰, beyond that of unmodified mantle (δ26Mg = −0.25 ± 0.04‰). The isotopic data form a trend from mantle-like δ26Mg at relatively high MgO towards elevated δ26Mg at low MgO, requiring the isotopic variability be related to differentiation in an open system involving assimilation of high-δ26Mg crustal rocks. Our results are generally consistent with Mg isotopic data compiled for global arcs where magmas have Mg isotopic ratios ranging from mantle-like to ∼0.7 per mil above the mantle range, and compositions substantially below that range are rare. Thus, heavy Mg isotopes in the continents predicted by igneous and weathering fractionation might have been compensated by a hidden input of light Mg isotopes, which is presumably in the form of carbonates, leading to a bulk crustal Mg isotopic composition that is mantle-like. [ABSTRACT FROM AUTHOR]

Dehydration of subducting oceanic crust and underlying serpentinized mantle is potentially the most important source of fluids for element cycling between surface-processed materials and the interior of the Earth. Magnesium (Mg) isotopes -have been proposed as a promising tracer of dehydration of serpentinites because of their high Mg contents and distinctive Mg isotopic signatures relative to the mantle, which is difficult to identify using other isotopes. To constrain the primary controls on Mg isotope cycling in subduction zones, here we analyze a suite of well-characterized sub-arc mantle xenoliths from the Avacha volcano in southern Kamchatka arc, Russia. They are comparable in modal and/or chemical composition to serpentinized fore-arc harzburgites and sub-arc harzburgite xenoliths from the western Pacific. Despite evidence for ubiquitous slab-related fluid metasomatism, the 23 spinel harzburgite xenoliths and four pyroxenite metasomatic veins display mantle-like δ26Mg values from −0.30 to −0.21‰. Mineral separates have similar δ26Mg values, with an average of −0.26 ± 0.04‰ (2SD, n = 17) for olivine, −0.23 ± 0.04‰ (2SD, n = 17) for orthopyroxene, and −0.24 ± 0.10‰ (2SD, n = 5) for late-stage interstitial clinopyroxene. The lack of a clear slab-derived δ26Mg signature in the Avacha sub-arc peridotites is probably due to their high MgO contents and low fluid/rock mass ratios during flux melting and metasomatism. We also compare published δ26Mg data for four volcanic arcs distributed worldwide. This inter-arc comparison reveals that the thermal structure of a subduction zone appears to exert a strong control on the efficiency of Mg isotope cycling from the downgoing slab to the mantle wedge and subsequently to the arc magmas; those arcs that permit large-scale dehydration of Mg-rich serpentinized slab mantle, coupled with available channelized fluid pathways, are more likely to produce isotopically diverse arc magmas. [ABSTRACT FROM AUTHOR]

Substantial quantities of oceanic slabs are known to be recycled into the mantle through subduction. However, tracing their fate in the mantle through studies of mantle-derived samples is not always straightforward. As K represents an omnipresent element in subducting crustal materials, its two stable isotopes (39K and 41K) display outstanding potential in tracing recycled crustal materials in the mantle. Here we report the first set of K isotopic data for a suite of well-characterized continental basaltic lavas from Northeast China. The δ41K of these lavas exhibit large variation from −0.81‰ to −0.15‰, compared with the narrow range of unaltered oceanic basalts (−0.43 ± 0.03‰). The isotopic variations, together with geochemical data obtained in earlier studies, cannot be ascribed to chemical weathering, crystal fractionation, crustal contamination, or partial melting, but are consistent with the presence of diverse crustal materials in magma sources. Recycled oceanic crust and sediments both have contributed to the contrasting K isotopic signature observed in these lavas. Our study here highlights the potential of using K isotopes to trace different types of recycled crustal materials in the mantle and places new constraints on the generation of enriched mantle reservoirs. [ABSTRACT FROM AUTHOR]

Assessing the K isotopic composition of the upper continental crust is important for understanding the processes by which the crust is generated and modified, and constraining the K isotopic budget of the silicate Earth. High-precision K isotopic data are reported for 70 well-characterized individual and composite samples from the upper continental crust, including diorite, granodiorite, granite, loess, shale, graywacke, pelite, and tillite, to constrain its K isotopic composition. δ41K varies significantly in eight I-type and two S-type granites from Australia (−0.57 to −0.40‰), nine A-type granites (−0.53 to −0.38‰), and three granitoid composites including diorite, granodiorite, and granite (−0.50 to −0.37‰) from China, mainly reflecting source heterogeneity. The 22 post-Archean Australian shales (PAAS) (δ41K = −0.68 to −0.12‰) and the 12 sedimentary composites including graywacke, pelite, and tillite from China (δ41K = −0.57 to −0.23‰) have heterogeneous K isotopic compositions while the 12 loess samples from around the world display more limited K isotopic variation (δ41K = −0.47 to −0.35‰). δ41K values display a smaller dispersion in loess compared to shales, which have comparatively more intense weathering and higher chemical index of alteration (CIA). δ41K correlates with Fe 2 O 3 /Al 2 O 3 and Fe 2 O 3 /K 2 O in shales and Al 2 O 3 /SiO 2 , K 2 O/Al 2 O 3 , and δ7Li in loess, suggesting that K isotopes are fractionated during chemical weathering. Overall, the upper continental crust has a heterogeneous K isotopic composition, ranging from −0.68 to −0.12‰ with an average δ41K of −0.44 ± 0.05‰ (2SD, n = 88), which is indistinguishable from the mantle. [ABSTRACT FROM AUTHOR]

Abstract Fast pyrolysis, which is comparable with the enzyme or acid hydrolysis, should be considered for further development for fermentable levoglucosan (LG) production. This manuscript offers a broad review of the current status and future research perspectives of LG and its hydrolysates production from lignocellulosic biomass by fast pyrolysis for fermentation. The utilization, distribution and formation paths of LG from cellulose are presented. In consideration of the complexity of cellulose structure and lignocellulosic components, the influence of the major individual components (cellulose, hemicellulose, lignin and ash) and the structural properties (particle size, degree of polymerization and crystallinity) on the LG formation are reviewed. Aiming to further improve the yield of LG and the fermentability of pyrolysate, a number of pretreatment methods (e.g. hot-water pretreatment, acid pretreatment, acid impregnation) prior to fast pyrolysis, hydrolysis of LG and detoxification before fermentation, and microbial production of valuable products are also discussed in detail. At last, a brief conclusion for the challenge in this topic is provided. The low content of LG and the presentence of inhibitors to biocatalysts in the pyrolysate of lignocelluloses hamper the fermentable utilization of pyrolytic sugars, which need further investigation and improvement to make this process feasible. Graphical abstract fx1 Highlights • Levoglucosan (LG) from biomass by fast pyrolysis is reviewed in details. • Biomass components and structural properties on LG formation are presented. • Pretreatment techniques for fast hydrolysis are summarized. • Detoxification and hydrolysis of LG for fermentation are introduced. • Challenges for LG production and fermentation are proposed. [ABSTRACT FROM AUTHOR]

Highlights • Protein engineering realizes high activity and excretion of Ker in E. coli. • Rapid folding and maturation of Ker is essential for extracellular expression. • N-terminal propeptide engineering is highly efficient to obtain excellent Ker mutants. • Ker yield increased 9.26 times with feeding strategy in scale-up fermenter. Abstract Escherichia coli is one kind of the simple and excellent biosystem to overexpress heterologous enzymes, such as keratinolytic protease, an excellent enzyme to hydrolyze keratin substrate for broad industrial application. However, protein expression in E. coli frequently faces some problems such as inactive and inclusion body formation. This work described a series of protein engineering strategies of N-terminal propeptide replacement and site-directed mutagenesis to modify this enzyme activity and production. Site-directed mutagenesis (S180G/Y215S) on N-terminal propeptide altered mutant contributed to the highest specific activity (4725 ± 65 U/mg, more than 1300 U/mg improvement than wild-type enzyme). This comprehensive mutation also achieved 2.5-fold improvement of extracellular enzyme yield in shake-flask level. The fermentation strategies about optimizing glycerol feeding and inducing point in scale-up bioreactor resulted in tremendous leakage of keratinolytic protease (954 mg/L extracellular yield within 48 h, about 9.26-fold higher than the original shake-flask level) as well as cell lysis. Although this proposed strategy faces a major challenge to maintain cell integrity or viability, it still exists the opportunity to realize other enzymes extracellular expression in E. coli system and simplify downstream processing to meet the industrial application. [ABSTRACT FROM AUTHOR]

Graphical abstract Carbonaceous acid catalyst with high acid content was synthesized by metal (Zr) ion chelation and sulfonation of sodium carboxymethylcellulose. It catalyzed the esterification of oleic acid, with biodiesel yield > 99% at 40–90 °C (activation energy of 24.7 KJ/mol). Highlights • Carbon-based catalyst with various acid sites was synthesized. • Catalyst had high total acid content (8.45 mmol/g) for esterification of oleic acid. • High biodiesel yield (> 99%) was achieved at 40–90 °C with Ea of 24.7 KJ/mol. • 10 cycles with biodiesel yield > 87% at 90 °C for 2 h reaction. • 3 cycles with biodiesel yield > 93% at 50 °C for 6 h reaction. Abstract Carbonaceous catalyst, with a variety of acid sites, was successfully synthesized by a two-step method at low temperature. The synthesized catalyst (Zr-SO 3 H@CMC) was characterized by elemental analysis, XRD, ICP-OES, FT-IR, BET, SEM-EDX and Boehm titration. It had high total acid content (8.45 mmol/g) for oleic acid esterification with high biodiesel yields (> 99%) at 40–90 °C. Under conditions of 90 °C, 20/1 methanol/oleic acid molar ratio, 5 wt% catalyst and 2 h reaction time, biodiesel yield of > 87% was achieved after 10 cycles of use. At lower temperatures (40, 50 and 60 °C), biodiesel yield still reached 82%, 93% and 90% after 3 cycles, respectively. The high activity of Zr-SO 3 H@CMC benefited from low activation energy of 24.7 KJ/mol. It shows potential application for esterification of free fatty acids or pretreatment of oils with high acid value for the green production of biodiesel. [ABSTRACT FROM AUTHOR]

Abstract The Mg isotope compositions of weathering profiles developed on granite and granodiorite bedrock have been analyzed to investigate Mg isotope behavior during the weathering of felsic rocks in a continental environment. δ26Mg generally exhibits a small increase from the bedrock values, which range from −0.17 ± 0.06‰ to +0.07 ± 0.06‰, until the upper two meters in which a decrease is observed, producing near surface values between −0.14 ± 0.06‰ and +0.09 ± 0.06‰. The small observed increase in isotopic composition below 2 m is likely due to Mg loss to the hydrosphere during biotite weathering and in situ illite production, while the decrease at depths <2 m is likely due to illite weathering near the surface, with a possible minor contribution from downslope deposition of less weathered material. One hydrothermally altered profile shows more extreme fractionation, reaching δ26Mg values as heavy as +0.55 ± 0.06‰ in the near surface component of the section. The fractionation associated with Mg loss during weathering can be modeled by Rayleigh distillation with fractionation factors between the residual rock and fluid ranging from α = 1.00001 to 1.00040. The Mg isotope composition is primarily controlled by the behavior of illite in the weathering profile, as Mg isotope composition is positively correlated with the illite fraction of major Mg-bearing minerals. A thorough understanding of Mg isotope systematics in these complex clay minerals may permit the use of Mg isotopes in paleosols as paleoclimate indicators. Highlights • Mg isotopes are primarily controlled by illite behavior during granite weathering. • Profiles varied from δ26Mg ≅ −0.17‰ in the bedrock up to +0.09‰ in the regolith. • One hydrothermal profile varied from δ26Mg ≅ −0.07‰ in the bedrock up to +0.55‰. • Mg isotopes could help to elucidate Mg cycling in continental environments. [ABSTRACT FROM AUTHOR]

To investigate the behavior of Mg isotopes during low-temperature alteration of oceanic crust and to further understand its role in the global Mg cycle, we measured the Mg isotopic compositions ( 25 Mg/ 24 Mg and 26 Mg/ 24 Mg) of a set of samples of altered oceanic crust (AOC) recovered from the Ocean Drilling Program Hole 801C, the reference site for old crust (∼170 Ma) subducting in the Pacific. The measured δ 26 Mg values range from −1.70‰ to 0.21‰, deviating from that of pristine oceanic basalts (−0.25 ± 0.07‰). Composite samples of volcanoclastic breccia that have experienced relatively intense alteration have larger variation in δ 26 Mg values (−1.01‰ to 0.15‰) than composite samples of massive basaltic flows (−0.53‰ to −0.04‰), indicating significant Mg isotope fractionation during low-temperature alteration of the oceanic crust. Moreover, the upper off-axis basement has on average lower δ 26 Mg values (−1.70‰ to −0.04‰) than the lower on-axis basement (−0.16‰ to 0.21‰). These findings, combined with the co-variations between MgO content and FeO ∗ /CaO ratio and between δ 26 Mg and FeO ∗ /CaO ratio, suggest that formation of Mg-bearing minerals (i.e., saponite and calcite) during low-temperature alteration of the oceanic crust accounts for the highly variable δ 26 Mg of AOC. Early formation of saponite under anoxic condition preferentially takes up heavy Mg isotopes and accounts for Mg enrichment and relatively high δ 26 Mg in the on-axis basement. Subsequent precipitation of carbonates results in the dilution of Mg and relatively low δ 26 Mg in the off-axis basement. In addition, accumulation of carbonate-rich interflow sediments in the upper basement may contribute further to the low δ 26 Mg. A weighted average δ 26 Mg value of 0.00 ± 0.09‰ is estimated for the AOC at Site 801, implying that low-temperature alteration of oceanic crust drives the ocean to a lighter Mg isotopic composition, and thus requires additional carbonate precipitation to maintain a steady-state Mg isotopic composition of seawater. A mass balance calculation suggests that the Mg output flux due to low-temperature alteration of the oceanic crust equals ∼12% of the annual Mg riverine input, indicating that AOC is a significant sink of Mg in seawater. Our study further highlights that recycling of AOC with highly variable δ 26 Mg along with overlying marine sediments into the mantle through subduction may generate Mg isotopic heterogeneity in the mantle at small scales. [ABSTRACT FROM AUTHOR]

Biodiesel production from Jatropha oils with high acid value at low temperature was catalyzed with synthesized novel magnetic acid-base amphoteric nanoparticles (<46 nm). Alkaline oxides (ZnFe 2 O 4, ferrihydrite, zincite, maghemite and magnetite) concerted with acidic -COOFe structure, benefited the one-pot esterification and transesterification of Jatropha oils with high acid value to produce biodiesel without additional pretreatment. The strong magnetism of catalyst helped catalyst separation for recycle in continuous biodiesel production. Jatropha biodiesel yield of 100% at 160 °C within 4 h, with methanol/oil molar ratio of 40/1 and catalyst dosage of 7 wt% was achieved, while the catalyst can be cycled for at least 10 times with biodiesel yield >94.3% at acid value of 6.3 mg KOH/g. No obvious saponification was observed during the reactions and storage. [ABSTRACT FROM AUTHOR]

Fluids released from subducting slabs play an important role in mantle metasomatism and arc magmatism. Magnesium could be mobile in subduction-zone fluids and Mg isotopic signatures of mélange rocks may provide information on crust-mantle interactions at subduction zones. To investigate the behaviour of Mg isotopes during fluid metasomatism along the slab-mantle interface, we report Mg isotopic compositions of a set of well-characterized samples from the ultramafic blocks in the Franciscan Complex of California. The partially serpentinized and completely serpentinized peridotites have δ 26 Mg values (from −0.26 to −0.14) clustered around the mantle value, indicating small Mg isotope fractionation during peridotite serpentinization. Samples with serpentine completely replaced by talc have lower MgO contents and heavier Mg isotopic compositions (δ 26 Mg of −0.13 to −0.01) than serpentinized peridotites, implying that Mg was non-conservative during this metasomatic replacement. The shift toward higher δ 26 Mg values of talc-dominated metaperidotites reflects the preferential loss of light Mg isotopes into fluids via Rayleigh distillation during the dehydration reactions that produced talc from serpentine. On the other hand, samples with talc completely replaced by tremolite have lighter Mg isotopic compositions (δ 26 Mg of −0.50 to −0.41) and higher CaO contents than the talc-dominated samples. These features suggest a metasomatic process involving isotopically light carbonate-rich fluids derived from the subducting slab. Collectively, large Mg isotope fractionation occurs during multistage fluid-rock interactions within the Franciscan subduction channel, which provides direct evidence for significant Mg isotopic variation during fluid metasomatism along the slab-mantle interface. This may account for the observed heterogeneous Mg isotopic compositions of arc lavas. Magnesium isotopes thus could be a potentially useful tracer of crust-mantle interactions at subduction zones. [ABSTRACT FROM AUTHOR]

A novel sesquilignan compound ( 1 ), possesing an unusual carbon skeleton of aryltetralin unit linked with a C6-C3 unit and a five-membered ring by a C-7″ and C-4 linkage pattern via an oxygen atom, and a new lignan glycoside ( 2 ) have been isolated from the twigs and leaves of Illicium majus . Their structures were determined by spectroscopic analysis and chemical methods. The absolute configurations of 1 and 2 are confirmed by observing the circular dichroism. At 10 μM, Compounds 1 and 2 showed in Vitro inhibitory activity against the release of β -glucuronidase in rat polymorphonuclear leukocytes induced by platelet-activating factor. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel pretreatment of wheat straw combined with NaAlO 2 and BM was developed. • Glucose yield (95.4%) at 24 h increased by 3.7 times that of raw straw (20.3%). • NaAlO 2 BM pretreatment required less energy in reducing particle size and CrI. • Highest energy efficiency was 0.121 kg glucose/kWh with NaAlO 2 BM 20 min treatment. • Effects of energy consumption on alterations of structural proprieties were showed. Pretreatment of lignocellulosic biomass is crucial in producing fermentable sugars in a sustainable biorefinery. In this study, wheat straw was pretreated with a combination of ball milling (BM) and NaAlO 2 particles (NaAlO 2 -BM) for enzymatic hydrolysis within a short hydrolysis period. The effects of energy consumption on modifications of physicochemical proprieties and energy efficiency were elucidated. NaAlO 2 -BM pretreatment decreased particle size rapidly to tissue scale in 10 min with energy consumption reduced by 0.5 times compared to BM pretreatment. NaAlO 2 -BM pretreated for 20 min achieved a glucose yield of 95.4% at a cellulase loading of 10 FPU/g dry substrate for 24 h enzymatic hydrolysis and provided the highest energy efficiency of 0.121 kg glucose/kWh, increasing by 1.1 times than BM pretreatment. Energy consumption showed a positive relationship with cellulose content while it negatively correlated with median particle size, cellulose crystallinity and energy efficiency. The combination of BM and NaAlO 2 particles was demonstrated to be a promising pretreatment approach for glucose production and improving energy efficiency during hydrolysis of lignocellulose. [ABSTRACT FROM AUTHOR]

Magnesium isotopic compositions of olivine, clinopyroxene, and ilmenite from the Baima intrusion, SW China, for the first time, are investigated to constrain the magnitude and mechanisms of Mg isotope fractionation among cumulus minerals in layered mafic intrusions and to evaluate their geological implications. Olivine and clinopyroxene have limited Mg isotope variations, with δ 26 Mg ranging from −0.33 to +0.05‰ and from −0.29 to −0.13‰, respectively, similar to those of mantle xenolithic peridotites. By contrast, ilmenites display extremely large Mg isotopic variation, with δ 26 Mg ranging from −0.50 to +1.90‰. The large inter-mineral fractionations of Mg isotopes between ilmenite and silicates may reflect both equilibrium and kinetic processes. A few ilmenites have lighter Mg isotopic compositions than coexisting silicates and contain high MgO contents without compositional zoning, indicating equilibrium fractionation. The implication is that the light Mg isotopic compositions of lunar high-Ti basalts may result from an isotopically light source enriched in cumulate ilmenites. On the other hand, most ilmenites have heavy Mg isotopic compositions, coupled with high MgO concentration and chemical zoning, which can be quantitatively modeled by kinetic Mg isotope fractionations induced by subsolidus Mg–Fe exchange between ilmenite and ferromagnesian silicates during the cooling of the Baima intrusion. The extensive occurrence of kinetic Mg isotope fractionation in ilmenites implies the possibility of widespread compositional disequilibrium among igneous minerals in magma chambers. Consequently, disequilibrium effects need to be considered in studies of basaltic magma evolution, magma chamber processes, and magmatic Fe–Ti oxide ore genesis. [ABSTRACT FROM AUTHOR]

The electrochemical activity of electroactive bacteria is unique and essential for bioelectrochemical systems (BES) with promising energy and environment applications. However, the strategies for bacterial electrochemical activity modulation are still limited. Herein, a novel approach for engineering of bacterial electrochemical activity with global regulator (sigma factor RpoS) manipulation was developed. By knockout of rpoS in Pseudomonas aeruginosa PAO1, the biofilm formation on the electrode was enhanced and the bacterial cells were adapted to a new electron shuttle, which promoted the extracellular electron transfer and improved the performance of BES. This work demonstrated that global regulator manipulation could be efficient for electrochemical activity engineering and offered new opportunities for BES applications. [ABSTRACT FROM AUTHOR]

Keratinase has great potential to convert poultry waste into feed or fertilizers. In order to obtain excellent keratinase variants with improved thermostability and activity to degrade feather waste, we did rational protein engineering approaches. Using site-directed mutagenesis on keratinase FDD, two variants (Y94F and Y215F) showed higher extracellular keratinolytic activity and specific activity in Escherichia coli expression system. The C-terminus fusion on keratinase DDF created a new variant DDFD with the highest substrate specificity and keratinolytic activity of 6220 ± 20 U/mg. Besides, the performance of thermophilicity and theromostability of the variants was evaluated. The A218S and A218G showed more than 30% improvement of relative activity at 70 °C while DDFD owned the most outstanding comprehensive performance between half-life ( t 1/2 = 146 min) and keratinolytic activity. It is highly effective to obtain excellent keratinases by site-directed mutagenesis and C-terminus fusion based on model structure analysis, and it provides possibility of industrial application of new keratinases. [ABSTRACT FROM AUTHOR]

Biodiesel production was catalyzed by a novel magnetic carbonaceous acid (Zr-CMC-SO 3 H@3Fe-C 400 ) with both Brønsted and Lewis sites synthesized by a four-step method: (i) metal (Fe) ion chelation, (ii) calcination, (iii) metal (Zr) ion chelation and embedding, and (iv) sulfonation. It catalyzed the esterification of oleic acid with 97% biodiesel yield, transesterification of high acid value (AV) soybean oil with 95% biodiesel yield, and pretreatment of Jatropha oil with AV reduced from 17.2 to 0.7 mg KOH/g. Biodiesel yields (>90%) at 90 °C for 4 h reaction time were obtained for ten cycles by easy magnetic separation which showed potential practical applications in the field of green production. The synthesized catalyst was characterized with elemental analysis, XRD, ICP-OES, FT-IR, BET, VSM, SEM-EDX, HRTEM, TG-DSC and Boehm titration. [ABSTRACT FROM AUTHOR]

Slab-derived fluids play a key role in mass transfer and elemental/isotopic exchanges in subduction zones. The exhumation of deeply subducted crust is achieved via a subduction channel where fluids from various sources are abundant, and thus the chemical/isotopic compositions of these rocks could have been modified by subduction-zone fluid–rock interactions. Here, we investigate the Mg isotopic systematics of eclogites from southwestern Tianshan, in conjunction with major/trace element and Sr-Nd isotopes, to characterize the source and nature of fluids and to decipher how fluid–rock interactions in subduction channel might influence the Mg isotopic systematics of exhumed eclogites. The eclogites have high LILEs (especially Ba) and Pb, high initial 87 Sr/ 86 Sr (up to 0.7117; higher than that of coeval seawater), and varying Ni and Co (mostly lower than those of oceanic basalts), suggesting that these eclogites have interacted with metamorphic fluids mainly released from subducted sediments, with minor contributions from altered oceanic crust or altered abyssal peridotites. The positive correlation between 87 Sr/ 86 Sr and Pb* (an index of Pb enrichment; Pb* = 2*Pb N /[Ce N + Pr N ]), and the decoupling relationships and bidirectional patterns in 87 Sr/ 86 Sr-Rb/Sr, Pb*-Rb/Sr and Pb*-Ba/Pb spaces imply the presence of two compositionally different components for the fluids: one enriched in LILEs, and the other enriched in Pb and 87 Sr/ 86 Sr. The systematically heavier Mg isotopic compositions (δ 26 Mg = − 0.37 to + 0.26) relative to oceanic basalts (− 0.25 ± 0.07) and the roughly negative correlation of δ 26 Mg with MgO for the southwestern Tianshan eclogites, cannot be explained by inheritance of Mg isotopic signatures from ancient seafloor alteration or prograde metamorphism. Instead, the signatures are most likely produced by fluid–rock interactions during the exhumation of eclogites. The high Rb/Sr and Ba/Pb but low Pb* eclogites generally have high bulk-rock δ 26 Mg values, whereas high Pb* and 87 Sr/ 86 Sr eclogites have mantle-like δ 26 Mg values, suggesting that the two fluid components have diverse influences on the Mg isotopic systematics of these eclogites. The LILE-rich fluid component, possibly derived from mica-group minerals, contains a considerable amount of isotopically heavy Mg that has shifted the δ 26 Mg of the eclogites towards higher values. By contrast, the 87 Sr/ 86 Sr- and Pb-rich fluid component, most likely released from epidote-group minerals in metasediments, has little Mg so as not to modify the Mg isotopic composition of the eclogites. In addition, the influence of talc-derived fluid might be evident in a very few eclogites that have low Rb/Sr and Ba/Pb but slightly heavier Mg isotopic compositions. These findings represent an important step toward a broad understanding of the Mg isotope geochemistry in subduction zones, and contributing to understanding why island arc basalts have averagely heavier Mg isotopic compositions than the normal mantle. [ABSTRACT FROM AUTHOR]

Subducted sediments have been suggested to be a possible cause for local Mg isotopic variation in the overall homogeneous mantle based on anomalous Mg isotopic compositions detected in some mantle-derived rocks. Here we examine the Mg isotopic systematics of 77 bulk marine sediment samples from ten DSDP and ODP drill sites adjacent to the world's major subduction zones to assess their potential to cause mantle heterogeneity. In contrast to the limited mantle range (δ 26 Mg = − 0.25 ± 0.07‰), δ 26 Mg of these sediments varies widely from − 1.34‰ to + 0.46‰, which is similar to values measured in continental sediments and appears to be linked to sediment lithology. Calcareous oozes are generally isotopically lighter than seawater; however, the presence of detrital impurities can shift their δ 26 Mg to higher values. In comparison to calcareous oozes, Mg-rich aluminosilicate sediments typically have higher δ 26 Mg values, although they may be either isotopically heavier or lighter than the mantle. Detrital sediments are the dominant sediment type and display large variation (− 0.90‰ to + 0.18‰) that reflects provenance heterogeneity and textural/mineralogical sorting. Sediments derived from juvenile terranes have δ 26 Mg similar to mantle values while those derived from mature, and thus more strongly weathered sources, often have higher δ 26 Mg values. On the other hand, turbidites may have lower δ 26 Mg values if containing isotopically light dolomite and/or garnet. In addition, clay-size fractions in turbidites commonly have higher δ 26 Mg than the associated sands. Hydrogenetic clays have a relatively high and uniform δ 26 Mg value of + 0.02 ± 0.14‰ (2SD, n = 14), suggesting preferential uptake of heavy Mg isotopes during authigenic clay formation while hydrothermal clays have highly variable δ 26 Mg values (− 0.57‰ to + 0.46‰) that likely reflect variable exchange with seawater/hydrothermal fluids. Overall, considerable variations exist in both regional Mg mass flux and the weighted δ 26 Mg average of sedimentary sections subducting at different trenches. The flux-weighted δ 26 Mg of − 0.336‰ is estimated for Global Subducting Sediments (GLOSS-II), which is isotopically lighter than the mantle average because of the presence of thick turbidite sequences with relatively low δ 26 Mg values and local carbonate enrichment in a few trenches near the equator. Therefore, it appears that subducting marine sediments are a source of heterogeneous δ 26 Mg values in the mantle, and they may be manifested locally in volcanic rocks that form in regions having a high flux of sediment melts to the mantle. [ABSTRACT FROM AUTHOR]

Long-short term memory (LSTM) network is one of the state-of-the-art models to forecast the movement of financial time series (FTS). However, existing LSTM networks do not perform well in the long-term forecasting FTS with sharp change points, which significantly influences the accumulated returns. This paper proposes a novel long-term forecasting method of FTS movement based on a modified adaptive LSTM model. The adaptive network mainly consists of two LSTM layers followed by a pair of batch normalization (BN) layers, a dropout layer and a binary classifier. In order to capture the important profit points, we propose to use an adaptive cross-entropy loss function that enhances the prediction capacity on the sharp changes and deemphasizes the slight oscillations. Then, we perform the forecasting on multiple independent networks and vote on their output data to obtain stable forecasting result. Considering the temporal correlation of FTS, an inherited training strategy is introduced to accelerate the retraining procedure when performing the long-term forecasting task. The proposed methods are assessed and verified by the numerical experiments on the stock index datasets, including "Standard's & Poor's 500 Index", "China Securities Index 300" and "Shanghai Stock Exchange 180". A substantial improvement of forecasting performance is proved. Moreover, the proposed hybrid forecasting framework can be generalized to different FTS datasets and deep learning models. • LSTM network is a useful model to forecast the movement of financial time series. • The proposed forecasting framework can bring more accumulated returns. • The adaptive loss function enhances the forecasting capacity on the sharp changes. • A stable result is obtained using vote operation on multiple independent results. • An inherited training accelerates the fine-turn procedure in a long-term prediction. [ABSTRACT FROM AUTHOR]

Herein, xMg 2 B 2 O 5 -(1-x)Ba 3 V 2 O 8 (0.5 ≤x ≤ 0.7) microwave dielectric composite ceramics were prepared via the solid-state reaction method at a relatively low sintering temperature (around 940–1020 °C). The phase compositions, microstructure, and elemental compositions of the ceramics were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM) combined with energy-dispersive spectroscopy (EDS), respectively. According to the results, both Mg 2 B 2 O 5 and Ba 3 V 2 O 8 phases coexisted after sintering in the temperature range of 940–1020 °C. The growth of Ba 3 V 2 O 8 grains was inhibited by the increase in amount of Mg 2 B 2 O 5 inclusions. Moreover, mixing these two phases in a proper ratio did not only reduce the sintering temperature, but also improved the temperature coefficient of resonant frequency (τ f) and Q×f value (Q is quality factor=1/ dielectric loss, f=resonant frequency) of the xMg 2 B 2 O 5 -(1-x)Ba 3 V 2 O 8 microwave dielectric ceramics. In particular, the optimal microwave dielectric properties (ε r = 10.1, Q×f = 48,050 GHz, τ f = −3 ppm/°C) were reached after 2 h of sintering at 960 °C for the ceramic with x = 0.7. • The sintering temperature of the xMg 2 B 2 O 5 -(1-x)Ba 3 (VO 4) 2 (x = 0.5–0.7) composite ceramics could be reduced to 960 °C. • The quality factor was improved to 48,050 GHz by combining Mg 2 B 2 O 5 and Ba 3 V 2 O 8. • A near-zero temperature coefficient of the resonant frequency (τ f) could be obtained by adjusting the molar ratio of the two phases. • Mg 2 B 2 O 5 and Ba 3 V 2 O 8 were chemically compatible with each other. [ABSTRACT FROM AUTHOR]

Herein we report the discovery of a series of new small molecule inhibitors of histone lysine demethylase 4D (KDM4D). Molecular docking was first performed to screen for new KDM4D inhibitors from various chemical databases. Two hit compounds were retrieved. Further structural optimization and structure-activity relationship (SAR) analysis were carried out to the more selective one, compound 2 , which led to the discovery of several new KDM4D inhibitors. Among them, compound 10r is the most potent one with an IC 50 value of 0.41 ± 0.03 μM against KDM4D. Overall, compound 10r could be taken as a good lead compound for further studies. [ABSTRACT FROM AUTHOR]

In this paper, a wind energy harvester, which can be used as building skin, is developed. In order to overcome the defects of traditional wind energy harvester, such as expensive and crisp, the developed harvester is designed as a circular silicon plate with several symmetrically distributed rectangular cavities which were covered with ZnO (Zinc oxide) thin film. It is verified whether the designed harvester can function in turbulence flow by theoretical analysis and finite element analysis. The acoustic measurement illustrated that the output of designed device is linear to the frequency. And, the wind fluid experiments suggested that the thin film can vibrate under a low wind velocity 1 m/s and is easy to vibrate in wind turbulence. The maximum output power density is 23.39nW/cm 2 with a maximum open circuit output voltage 2.81 V. All of characteristics of designed harvester enable that it can be used as the building skin to harvest wind energy. [ABSTRACT FROM AUTHOR]

To constrain the Mg isotopic composition of the oceanic mantle, investigate Mg isotope fractionation of abyssal peridotites during seafloor alteration, and assess Mg budget in the oceans, a suite of 32 abyssal peridotite samples from the Gakkel Ridge and Southwest Indian Ridge (SWIR) was, for the first time, selected for high-precision Mg isotope analyses. Although most of these samples are extensively altered, largely by serpentinization and weathering, primary olivine, diopside and enstatite grains are preserved in some samples. Olivine grains from the least altered samples have δ 26 Mg varying from −0.30 to −0.12‰ ( n = 7), whereas enstatite and diopside have δ 26 Mg varying from −0.27 to −0.16‰ ( n = 7), and from −0.23 to −0.09‰ ( n = 6), respectively. Whole-rock δ 26 Mg values range from −0.24 to 0.03‰ with an average of −0.12 ± 0.13‰ (2SD, n = 32). Strongly serpentinized peridotites have lower average δ 26 Mg values (δ 26 Mg = −0.19 ± 0.07‰, 2SD, n = 7) than weathering-dominated ones (δ 26 Mg = −0.10 ± 0.12‰, 2SD, n = 25). Calculated Mg isotopic compositions of fresh mantle peridotites vary from −0.29 to −0.13‰, beyond the previously reported range of the subcontinental lithospheric mantle (−0.25 ± 0.04‰) and the analytical uncertainty (±0.07‰, 2SD). Our study therefore indicates that the oceanic mantle may have similar but slightly heterogeneous Mg isotopic compositions to that of subcontinental lithospheric mantle. Secondary serpentinization does not fractionate Mg isotopes of abyssal peridotites, whereas low-T weathering and formation of clay can result in the enrichment of heavy Mg isotopes in abyssal peridotites. This study also demonstrates that fluid-rock interaction does not necessarily produce rocks with intermediate Mg isotopic compositions. Magnesium isotopes of the rocks thereafter are dependent on the secondary minerals formed. We also conclude that the release of light Mg isotopes into the ocean during alteration of abyssal peridotites can be an important influx of Mg for the seawater Mg budget. Abyssal peridotites with a heavy Mg isotopic signature can be recycled into the mantle in subduction zones and may thus result in heterogeneous Mg isotopic compositions of the oceanic mantle and heavy Mg isotopic compositions of arc magmas. [ABSTRACT FROM AUTHOR]

A series of metal-zeolite hybrids was prepared by impregnation and deposition-precipitation methods and charaterized with different techniques. Catalytic performance of these catalysts on microwave-assisted conversion of selected carbohydrates to the fuel component methyl levulinate (ML) in methanol was studied. It was demonstrated that metal oxide content/type and acid-base bifunctionality were closely correlated with substrate conversion and ML yield, respectively. Among various as-prepared catalysts, zirconia-zeolite hybrid ZrY6(0.5) with moderate acid-base site content (0.97 & 0.08 mmol g −1 ), high stability and porosity (average mesopore diameter: 6.2 nm) exhibited superior catalytic activity. At 180 °C, around 67–73%, 78%, 53% and 27% yields of ML could be achieved from monosaccharides (e.g., glucose, mannose and galactose), sucrose, starch and cellulose, respectively. The Zr-Y6(0.5) hybrid exhibited good stability, and could be reused for five times with ML yields of ≥63% from glucose. [ABSTRACT FROM AUTHOR]

Modern dolomite formation is conditional and restricted in specific environmental and geochemical conditions, accordingly cannot be used as the analog of ancient dolostones, which normally have platform-wide distribution. The key to understand ancient dolostone formation is to find a dolomitization process that is independent of physical/geochemical environments. It is well-known that ribbon rock (one type of calcareous rhythmites, sensu stricto referring to the alternating limestone and marlstone layers or the limestone-marl alternations) that are deposited in nearly all marine environments throughout the Earth's history, are exclusively, though normally partially, dolomitized. Thus, understanding ribbon rock dolomitization may provide valuable insight into the ‘dolomite problem’. In this study, we measured Mg isotopic compositions ( δ 26 Mg) of ribbon rock samples collected from the Ediacaran Doushantuo Formation in South China. The marlstone layers contain higher dolomite contents and are characterized by higher δ 26 Mg (ranging from − 2.68‰ to − 1.84‰) than the limestone layers (varying between − 3.21‰ and − 2.53‰). A numerical model calculation indicates that clay minerals cannot provide enough Mg for dolomitization, arguing against the traditional interpretation that dolomitization is resulted from diagenetic Mg release from clays. Instead, contemporaneous seawater might provide sufficient Mg for dolomitization, because both Mg isotopes and dolomite content can be simulated by the Diffusion-Advection-Reaction model. Contemporaneous seawater dolomitization requires kinetic barrier be overcome at shallow depth of sediments. We propose the ribbon rock dolomitization is attributed to differential diagenesis of the clay-rich and clay-poor sediment layers, in which Ca 2 + -Mg 2 + exchange elevates porewater Mg/Ca in clay-rich layers. [ABSTRACT FROM AUTHOR]

We investigate in detail the chiral thermal transition of QCD in an improved soft-wall AdS/QCD model with a simply modified 5D conformal mass of the bulk scalar field. We also present a calculation in this model for the light meson spectra and other low-energy characteristic quantities including the pion form factor, the π – ρ coupling constant and the decay constants of π , ρ , a 1 , which are shown to result in a good agreement with experimental data except for the pion decay constant. The thermal behavior of chiral condensate is studied. It is found that such a simply improved soft-wall model incorporates the crossover behavior of chiral thermal transition indicated by lattice simulations. The expected chiral transition temperature can be obtained. [ABSTRACT FROM AUTHOR]

Magnesium isotopic compositions of igneous rocks could be potentially used to trace recycling of supracrustal materials. High-δ 26 Mg granitoids have been previously reported and explained to reflect the involvement of surface weathered materials in their sources. Low-δ 26 Mg granitoids, however, have not been reported. In this study, we report high-precision Mg isotopic analyses of Cenozoic alkaline syenites and syenogranites from the Kuzigan and Zankan plutons, northwest Xinjiang, China. The Kuzigan syenites were originated from the mantle metasomatized by recycled supracrustal materials, and the syenogranites are differentiated products of the syenites. Both syenites and syenogranites have δ 26 Mg values (− 0.46 to − 0.26‰ and − 0.41 to − 0.17‰, respectively) significantly lighter than the mantle (− 0.25 ± 0.07‰, 2SD). No correlation of δ 26 Mg with either SiO 2 or MgO is observed, indicating limited Mg isotope fractionation during alkaline magmatic differentiation. The low δ 26 Mg of the syenites and syenogranites thus reflects a light Mg isotopic source. This, combined with high 87 Sr/ 86 Sr ratios (0.70814 to 0.71105) and negative correlation between δ 26 Mg and δ 18 O, suggests that the magma source contains recycled marine carbonates. Modeling of the Mg-O-Sr isotopic data indicates that the recycled carbonate is mainly limestone with minor dolostone, suggesting that the metasomatism occurred at depths shallower than 60 to 120 km. Given that the plutons are located at the India–Eurasia collision zone, the carbonate recycling was most likely derived from the subducted Tethyan oceanic crust during the Mesozoic–Cenozoic. Our study suggests that the combined Mg, O, and Sr isotopic studies are powerful for tracing recycled carbonates and identifying their species in mantle sources. [ABSTRACT FROM AUTHOR]

In this study, lignocellulose nanofibril (LCNF) was prepared from high yield pulps (HYP) by hydrated choline chloride-ethylene glycol (CE) in combination with mechanical treatment. TEMPO-oxidized cellulose nanofibrils (TO-CNF), LCNF and LCNF/TO-CNF composite films were then produced by a solution casting method. The yield of HYP reached up to 89.1 % with a lignin retention rate of 23.9 % under the optimal reaction condition (100 % DES). The obtained LCNF/TO-CNF composite film demonstrated several advantageous properties over LCNF and TO-CNF films including: 1) excellent mechanical properties, 2) higher hydrophobic property, and 3) improved thermal stability. Compared to composite straw by reconstructing the cellulose-lignin reinforced composite structure in previous reports, in this study, the fabricated LCNF/TO-CNF composite straw from the as-prepared film by a one-step process without complicated procedures, achieved comparable high mechanical performance and water resistance. Overall, this LCNF/TO-CNF composite film with appropriate performance is envisioned as a promising candidate to replace conventional plastics-based materials to produce single-use straw. [Display omitted] • LCNF was prepared from high yield pulps by DES hydrated in combination with mechanical treatment • LCNF/TO-CNF composite film have excellent mechanical properties, higher hydrophobic property and thermal stability. • LCNF/TO-CNF composite straw has potential to replace conventional plastics-based materials. [ABSTRACT FROM AUTHOR]

Elemental exchange during seafloor alteration exerts substantial control on the chemical compositions of seawater and oceanic crust, as well as the global elemental cycling. However, detailed processes and mechanisms for element transport and isotopic exchange remain unclear. Here, we report Li and K isotopic compositions across an altered MORB-like pillow basalt from Mariana Trench. We find large and systematic isotopic variations on a centimeter scale, with δ7Li decreasing from +9.07‰ to +6.21‰ and δ41K increasing from −0.12‰ to +0.33‰ from the rim to the core. The heavier-than-mantle Li and K isotopic compositions in the core likely inherit from an enriched mantle source rather than post-magmatic alteration processes. The low K and high Li isotopic compositions at the outmost rims result from adsorption during seawater-rock interactions. The basin-shaped elemental and isotopic variations were subsequently formed by chemical diffusion and spontaneous seawater penetration from the weathered rind to the interior of pillow basalt sample. This study uses a small-scale sampling approach and provides the first evidence for multi-mode chemical exchange in oceanic basalts and improves our understanding of the seafloor alteration processes. [ABSTRACT FROM AUTHOR]

AlkB homolog 5 (ALKBH5) is an RNA m6A demethylase involved in the regulation of genes transcription, translation and metabolism and has been considered as a promising therapeutic target for various human diseases, especially cancers. However, there is still a lack of potent and selective ALKBH5 inhibitors. Herein, we report a new class of ALKBH5 inhibitors containing the 1-aryl-1 H -pyrazole scaffold, which were obtained through fluorescence polarization-based screening, structural optimization and structure-activity relationship analysis. Among these compounds, 20m was the most potent one, which showed an IC 50 value of 0.021 μM in fluorescence polarization assay. Compound 20m exhibited high selectivity towards ALKBH5 versus FTO as well as other AlkB subfamily members, indicating good selectivity for ALKBH5. Cellular thermal shift assay (CETSA) analysis showed that 20m could efficiently stabilize ALKBH5 in HepG2 cells. Dot blot assay demonstrated that 20m could increase m6A level in intact cells. Collectively, 20m is a potent, selective and cell active ALKBH5 inhibitor and could be used as a versatile chemical probe to explore the biological function of ALKBH5. [Display omitted] • A series of 1-aryl-1 H -pyrazole derivatives were synthesized as ALKBH5 inhibitors. • The most potent one, 20m , showed high potency against ALKBH5 with an IC 50 value of 0.021 μM in FP assay. • Compound 20m exhibited high selectivity towards ALKBH5 versus FTO as well as other tested AlkB subfamily members. • Compound 20m could efficiently stabilize ALKBH5 and increase m6A level in intact cells. [ABSTRACT FROM AUTHOR]