Search

How to design ultra-strong, light-weight Cu alloys is a long-term pursuit in materials community, which is technically superior and cost-effective for their promising energy-saving applications. In this work, we prepared Cu-Mg alloyed thin films to study light element Mg alloying effects on the microstructure, hardness and strain rate sensitivity (SRS) of nanocrystalline Cu thin films. In the studied Mg concentration-range spanning from 0 at.% to 16.8 at.%, both the grain size and the twin spacing decrease monotonously with increasing Mg composition while Cu-2.8 at.% Mg sample has the highest twin fraction of ∼75%. A combined strengthening model was employed to quantify the Mg concentration-dependent hardness of nanotwinned (NT) Cu-Mg thin films, in which the grain/twin boundary facilitates strengthening while the solute Mg atoms induce softening. Both the constant rate of loading tests and the nanoindentation creep tests uncover that compared with pure Cu samples, the NT Cu-Mg thin films manifest much lower SRS, particularly in the creep tests, owing to the activation of dynamic strain aging effects.

Onion-like carbon (OLC) is one kind of a quasi-nanosphere with a concentric graphite shell structure and abundant mesopores, which is appropriate for a high rate of charging/discharging and long-lifespan cycling. However, the moderate specific surface area seriously impeded its capacitance performance in comparison with activated carbon and porous carbon. Herein, we have unlocked the Zn ion storage performance of OLC material through introducing N and P dopants. Benefitting from the fabricated N,P-OLC with a fully accessible external surface area for ion adsorption, high proportion of mesopores for fast ion migration, and synergistic effect of N and P co-doping in a carbon matrix favoring chemical adsorption of Zn

We report the co-mutations in AML with CEBPAWe retrospectively sequenced 112 genes in 302 patients with CEBPA① The average number of mutations in CEBPACEBPA

It is generally considered that the Al3Sc nanoprecipitates are highly thermal stable, mainly due to quite slow Sc diffusion in the α-Al matrix. In this paper, we demonstrate in an Al-Cu-Sc alloy that the Cu atoms have dual effect on the coarsening of Al3Sc nanoprecipitates. On the one hand, the Cu atoms with high diffusivity tend to accelerate the Al3Sc coarsening, which results from the Cu-promoted Sc diffusion. On the other hand, some Cu atoms will segregate at the Al3Sc/matrix interface, which further stabilizes the Al3Sc nanoprecipitates by reducing the interfacial energy. Competition between these two effects is tailored by temperature, which rationalizes the experimental findings that the coarsening kinetics of Al3Sc nanoprecipitate is greatly boosted at 300 °C-overaging while significantly suppressed at 400 °C-overaging.

Introduction: Several studies have confirmed that mutations in the Wilms tumor 1 (WT1) gene occur in adult acute myeloid leukemia (AML). However, few data are available regarding the incidence of WT1 mutations in CEBPAmut AML and their impact. Methods: We retrospectively analyzed the frequency and clinical impact of WT1 mutations in 220 newly diagnosed AML patients with CEBPA mutations. Chromosome karyotype analysis was performed by R or G banding method and further confirmed either by fluorescence in situ hybridization (FISH) and/or by multiple reverse transcription polymerase chain reaction (multiple RT-PCR). Mutations were detected with a panel of 112 mutational genes using next-generation sequencing (NGS). FLT3-ITD, NPM1 and CEBPA mutation were detected by PCR Sanger sequencing.Results: Overall, 30 WT1 mutations were detected in 29 of the 220 patients (13.18%) screened. These mutations clustered overwhelmingly in exon 7 (16 mutations in 15 patients), but they were also detected in exon 8 (n=6) and exon 9 (n=8). WT1-mutated (WT1mut) patients presented with lower platelet counts (P=0.0481), higher WT1 expression (P=0.0371), and a negative trend with the M5 subtype (P=0.07) compared to WT wild-type (WTwt) patients. WT1 mutations were found to be significantly more frequent in AML patients with double-mutated CEBPA (CEBPAdm) than in AML patients with single-mutated CEBPA (P=0.043). Of note, the concomitant mutations in epigenetic regulators were inversely correlated with WT1 mutations (P=0.003). Patients with newly diagnosed WT1mut AML had inferior relapse-free survival, event-free survival and overall survival compared with patients with WT1wt AML (P=0.002, 0.004, and 0.010, respectively). Conclusion: Our data showed that WT1 mutations are frequently identified in CEBPAmut AML, especially in CEBPAdm AML. Patients with WT1 mutations show distinct clinical features, a spectrum of comutations, and poor prognosis compared to WT1 wild-type patients.

In order to boost the energy density of supercapacitors, the strategy of using advanced pseudo-capacitive electrode and asymmetric device architecture is feasible and effective. Herein, we report a significant advance in the design and synthesis of a new hierarchically nanostructures with a series of controllable Ni/Co molar ratios of NixCo3-xS4 (i.e., NiCo2S4 and Ni2CoS4) nanosheets coatings have in situ grown on NiCo2O4 nanowires arrays on a flexible carbon fiber paper (CFP). Remarkably, the hybrid Ni2CoS4@NiCo2O4 composite electrode delivers the highest discharge gravimetric capacitance of 1501 F g−1, and areal capacitance of 1.86 F cm−2 at 1 mA cm−2. Furthermore, coupled with nitrogen-doped carbon xerogels anode, we have fabricated a 1.6 V asymmetric supercapacitor (Ni2CoS4@NiCo2O4//nitrogen-doped carbon xerogels), such device delivers a maximum energy and power densities of 32.2 Wh kg−1 and 2.5 kW kg−1 in 1.0 M KOH electrolyte, respectively, and an excellent cycling stability (∼87.6% retention after 10,000 cycles).

Lithium ion capacitors (LICs) are considered to be high-performance energy storage devices that have stimulated intense attention to bridge the gap between lithium ion battery and supercapacitor. Currently, the major challenge for LICs has been to improve the energy density without sacrificing the high rate of power output performance. Herein, we designed a three-dimensional (3D) hierarchical porous nanostructure of hydrogen-treated TiO2 nanoparticles wrapped conducting polymer polypyrrole (PPy) framework with single-walled carbon nanotubes (SWCNTs) hybrid (denoted as, H-TiO2/PPy/SWCNTs) anode material for LICs through a conventional and green approach. Such a unique network can offer continuous electron transport and reduce the diffusion length of lithium ions. A greatly lithium storage specific capacity is achieved with reversible discharge capacity ∼213 mA h g−1 (based on the mass of TiO2) over 50 cycles (@ 0.1 A g−1), which is almostly three times compared with raw TiO2 (a commercial TiO2 nanoparticles powder). In addition, coupled with commercial activated carbon (AC) cathode, the fully assembled H-TiO2/PPy/SWCNTs//AC LICs delivers a maximum energy and power densities of 31.3 Wh kg−1 and 4 kW kg−1, a reasonably good cycling stability (∼77.8% retention after 3000 cycles) within the voltage range of 1.0–3.0 V.

Liquid-phase exfoliation is an effective method to fabricate thin nanosheet materials with layered structure. In this paper, we successfully synthesized NH 4 Co 0.4 Ni 0.6 PO 4 ·H 2 O nanosheets with the thickness of about tens of nanometers through liquid-phase exfoliation under ultrasonication. Specifically, the formamide solution was chosen as the exfoliation solvent due to it is capable of entering the interlayer of bulk materials and rapidly swelling between layers. Electrochemistry tests revealed that the optimized exfoliation time was 4 days. The asymmetric battery type energy storage device AC//NH 4 Co 0.4 Ni 0.6 PO 4 ·H 2 O nanosheets showed an energy density of 10.8 Wh kg −1 at the power density of 703.1 W kg −1 . More importantly, the long-term cycle stability measurements demonstrated that NH 4 Co 0.4 Ni 0.6 PO 4 ·H 2 O nanosheets after exfoliation had an ultra-long cycling life that still retained 102.3% of specific capacitance even 10000 continuous charge/discharge cycles.

For multicomponent Al-based alloys, one of the most valuable approaches of microstructural design is to find a path to maximize the multiple microalloying effects while overcoming their negative counterparts. In this paper, triple Sc-Fe-Si microalloying was performed in an Al–Cu alloy to assemble the co-existence of θ′-Al2Cu and Al3Sc precipitates. Besides, the mutual interactions among triple microalloying elements were utilized to maximize the positive effects on tailoring the dual precipitates, as illustrated in two goals of microstructural design: (i). As to θ′-Al2Cu plates, the multiple Sc-Fe-Si segregation at θ′-Al2Cu/matrix interface was preferentially created in the alloy before creep (as-aged condition). During subsequent high-temperature creep, such interfacial warden will be rapidly reinforced by solute repositioning, as a process of accumulating solutes diffusing from both inner θ′-Al2Cu precipitate and outer matrix to limit the interfacial migration. (ii). For Al3Sc precipitates, the beneficial Si microalloying effect on encouraging the nucleation of Sc-rich entities (precursor of Al3Sc) was successfully acquired during aging, while the detrimental Si effect on accelerating Al3Sc coarsening is generally prohibited by tuning Fe–Si synergy within Al3Sc interior. The establishments of (i) and (ii) enable the satisfactory dispersion as well as the outstanding thermal stability of dual precipitates in the current Al-Cu-Sc-Fe-Si system, leading to a good creep resistance at a high homologous temperature of 0.61Tm ~ 300 °C (where Tm is the melting temperature of the α-Al matrix).

The formation of second-phase particles by solid-state precipitation is well-known as the most effective strengthening method for the light-weight aluminum (Al) alloys. Here, the interfacial evolutions from Sc solute segregation to Al3Sc precipitation at θ′-Al2Cu/matrix interfaces were investigated in an Al–Cu–Sc alloy crept at beyond 300 °C. By considering the trace Si impurity, it is proposed that Al3Sc precipitation preferentially occurs at the Si-concentrated interfacial locations, i.e. growth ledges. Two effects of interfacial Al3Sc precipitation on θ′-Al2Cu were demonstrated: (1) The Al3Sc precipitation was processed at the expense of the adjacent Sc segregation and allows localized θ′-Al2Cu decomposition, causing “precipitate splitting”. (2) The Al3Sc-enclosed growth ledges resultantly prevented θ′-Al2Cu from coarsening and equilibrium transformation to θ-phase at temperature as high as 400 °C. This work is expected to provide a precipitate-stabilizing strategy by interfacial architecture to maintain the closely spaced dispersion of precipitates and its strengthening contribution at elevated temperature.

Li–O2 batteries (LOBs) with ultrahigh theoretical energy density are regarded as the most promising next-generation candidates for energy storage and conversion devices. However, the development of LOBs is severely hindered by adverse parasitic reactions and sluggish reaction kinetics. Herein, hierarchical Ni3Se2/NiSe2 heterostructure nanoforests on Ni foam (Ni3Se2/NiSe2@NF) is designed as a high efficient bifunctional electrocatalyst for LOBs. As expected, owing to 3D hierarchically branched nanoforests structure, the Ni3Se2/NiSe2@NF electrode can build up an effective channel for mass transfer and expose sufficient active sites for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In addition, the strong interface interaction between Ni3Se2 and NiSe2 in the heterostructure causes distinct electron redistribution along the interface, which plays a vital role in enhancing electrocatalytic performance of Ni3Se2/NiSe2@NF. Accordingly, LOBs based on Ni3Se2/NiSe2@NF shows a high discharge specific capacity of 23,092 mA h g−1 at 500 mA g−1, a low voltage gap of 0.96 V and an improved cycling life of 500 cycles. It is worth noting that this study has a significant guidance for designing effective bifunctional electrocatalysts via constructing the heterostructure to boost oxygen electrode kinetics and improve Li–O2 battery performance.

Tungsten (W) laminate materials are very promising to improve the fracture toughness of tungsten. In this study, four kinds of tungsten laminated composites with different interlayers, including Ta, Ti, Ti/Ta/Ti, and W layers, are fabricated by spark plasma sintering (SPS). Compared with the W/W, W/Ti and W/Ta multilayer composites, the W/Ti/Ta composites exhibit the highest tensile strength (581 MPa) and elongation (7.9%). It shows that a gradual decrease of strength and a gradual increase of ductility from the W layer to the Ta layer can be obtained in the W/Ti/Ta multilayer composites. The tensile strength of these multilayer composites can be approximately predicted by the modified rule of mix. The toughening mechanism can be attributed to the energy dissipation caused by interfacial debonding, plastic deformation of interlayers, and crack bridging of the intermediate layer. The results show that the mechanical properties of the different tungsten-based multilayers are closely related to the toughening interlayers, which is beneficial to design tungsten laminates with high strength and toughness.

Co-stabilization of multiple precipitates has attracted growing attention as a promising approach to improve the performance of Al-based alloys at elevated temperatures. In this paper, three microalloying strategies, including 0.18 at.% Sc, 0.18 at.% Sc with 0.05 at.% Si, and 0.18 at.% Sc with 0.05 at.% Zr, are adopted to acquire an assembly of θ′-Al2Cu and Al3Sc precipitates in Al-1.08 at.%Cu alloys. The differences in chemical compositions are found to have huge impact on the stability of the precipitates and thus on the softening resistance of the alloys during thermal exposure at 300 °C. The results show that compared with Sc or Sc–Si microalloying, Sc–Zr microalloying in Al–Cu alloy is far more effective to co-stabilize the dual precipitates and thus improve the high-temperature resistance. Using transmission electron microscopy (TEM), the underlying mechanisms responsible for the distinct microalloying effects of the three strategies are revealed by: (i) the limited improvement of high-temperature resistance in Sc–Si microalloyed Al–Cu alloy results from a cumulative effect of the retarded θ′-Al2Cu coarsening and the accelerated Al3Sc growth. (ii). the combined Sc–Zr microalloying simultaneously stabilizes θ′-Al2Cu and Al3Sc precipitates, which dramatically suppresses the softening in Sc–Zr microalloyed alloy. Further experimental evidences of atom probe tomography (APT) suggest that the θ′-Al2Cu stabilization induced by combined Sc–Zr or Sc–Si microalloying is actually related to a modified multiple solute segregation at θ′-Al2Cu/α-Al interface to reduce the interfacial free energy. And the suppression and acceleration of Al3Sc coarsening kinetics induced by Sc–Zr and Sc–Si microalloying are attributed to Si-accelerated Sc diffusion and the formation of core-shell structural precipitates, respectively.

Previous work demonstrates that Fe2O3 is a promising negative electrode material. Its biochemical performance is strongly influenced by the morphology. Hence, Fe2O3 with nanoparticles, nanosheets and nanorods morphologies are synthesized by hydrothermal method respectively. The relationship between morphology and electrochemical property, particularly in terms of specific capacitance and rate capability are investigated. Detail cyclic voltammetry analysis reveals that the relative contributions of surface capacitive and inner intercalation capacitance change with the morphology. Different contribution of surface relative to inner charge storage leads to different specific capacitance and rate capability. Additionally, Fe2O3 nanosheets delivers a remarkable specific capacitance of 279.9 F g−1 (419.8 mF cm−2) at the scan rate of 5 mV s−1 ascribing to the inner intercalation effect. Moreover, electrochemical tests in neutral and alkaline solution show that the capacitive behavior of Fe2O3 is closely related to the potential window and different electrolyte leads to different contribution of surface relative to inner charge storage. These studies should be useful for elucidating the mechanism and morphological effects on charge storage for Fe2O3-based electrode and provide a direction to enhance its capacitance.

A porous carbon electrode incorporating considerations both heteroatom doping and pore structure design with: combination of melamine and PEO–PPO–PEO (polyethylene oxide–polypropylene oxide–polyethylene oxide) micelles for the nitrogen-doping and optimization the micron-duct formation; integration of CO2-etching into the carbonization process for the formation of abundant micropores. The structure of these nitrogen-doped carbon xerogels (NCXs) are indeed comprised of a multi-scaled pores having nano-porous carbon in a network of micron-size percolated hollow-channels. The resulted material has an ultrahigh surface area of 4279 m2 g−1 when used as electrode for supercapacitor, which deliver a high specific capacitance of 271 F g−1 with excellent cycle stability and good rate capability.

Dimensionality and rational design of electrode architectures play a crucial role in determining materials' fundamental properties and the electrochemical performance of supercapacitor. For a proof-of-concept, Ni–Co layered double hydroxides (LDH), NiCo2O4 and NiCo2S4 nanosheets supported on carbon fiber paper (CFP) substrate are prepared by simple hydrothermal methods in this work. When tested as the pseudo-capacitor positive electrode, the self-support nanosheets on CFP demonstrate good performance and rate capability as well as excellent cycling life, which contributes to the unique hierarchical nanosheets structure supported on 3D conductive CFP substrate with open permeable channels, facilitating electrolyte penetration and ensuring more efficient ion diffusion and faster electron transport. The asymmetric supercapacitor based on pseudocapacitance of both electrodes is further first realized by using NiCo2S4 nanosheets and FeOOH nanorods as positive and negative materials, respectively. The obtained device can deliver a maximum power density of 8.6 kW kg−1 and energy density of 45.9 Wh kg−1 and even after 10000 reversible cycles at a cell voltage of 1.6 V in aqueous electrolyte, there still retained 86.4% of its initial capacitance.

In this paper we synthesize well aligned Ni–Co sulfide nanowire arrays (NWAs) with a Ni–Co molar ratio of 1 : 1 on 3D nickel foam by a facile two-step hydrothermal method. Owing to the low electronegativity of sulfur, Ni–Co sulfide NWAs exhibit a more flexible structure and much higher conductivity compared with Ni–Co oxide NWAs when used as active materials in supercapacitors. The electrochemistry tests show that these self-supported electrodes are able to deliver ultrahigh specific capacitance (2415 F g−1 and 1176 F g−1 at a current density of 2.5 mA cm−2 and 30 mA cm−2, respectively), together with a considerable areal capacitance (6.0 F cm−2 and 2.94 F cm−2 at a current density of 2.5 mA cm−2 and 30 mA cm−2, respectively), and good rate capability. More importantly, the asymmetric supercapacitor, composed of Ni–Co sulfide NWAs as the positive electrode and activated carbon as the negative electrode, reaches up to an energy density of 25 W h kg−1 and a power density of 3.57 kW kg−1 under a cell voltage of 1.8 V. Furthermore, the two assembled supercapacitors in series can power a 3 mm diameter red (2.0 V, 20 mA) round light-emitting diode (LED) indicator for more than 30 minutes after charging separately for a total time of 6 min. The superior electrochemistry capacity demonstrates that the self-standing Ni–Co sulfide nanowire arrays are promising for high-performance supercapacitor applications.

A new 3D V2O5@PPy network built from numerous ultrathin, flexible and single-crystalline nanoribbons was successfully fabricated by a combined hydrothermal, freeze-drying and nanocasting process. Such a unique network can not only provide a high surface area for enhancement of electrolyte/electrode interactions, and reduce the diffusion length of ions, but also efficiently maintain the high electrical conductivity. As a result, this network exhibits high capacitance, excellent rate capability and good charge–discharge stability for energy storage. An asymmetric supercapacitor based on a 3D V2O5@PPy network as the cathode material further delivers high energy density and high power density. We expect that our work presents an efficient approach to design and produce various 3D architectures built from nanoribbons or nanosheets for energy storage and other applications.

Various two-dimensional (2D) materials have recently attracted great attention owing to their unique properties and wide application potential in electronics, catalysis, energy storage, and conversion. However, large-scale production of ultrathin sheets and functional nanosheets remains a scientific and engineering challenge. Here we demonstrate an efficient approach for large-scale production of V2O5 nanosheets having a thickness of 4 nm and utilization as building blocks for constructing 3D architectures via a freeze-drying process. The resulting highly flexible V2O5 structures possess a surface area of 133 m(2) g(-1), ultrathin walls, and multilevel pores. Such unique features are favorable for providing easy access of the electrolyte to the structure when they are used as a supercapacitor electrode, and they also provide a large electroactive surface that advantageous in energy storage applications. As a consequence, a high specific capacitance of 451 F g(-1) is achieved in a neutral aqueous Na2SO4 electrolyte as the 3D architectures are utilized for energy storage. Remarkably, the capacitance retention after 4000 cycles is more than 90%, and the energy density is up to 107 W·h·kg(-1) at a high power density of 9.4 kW kg(-1).

Despite various electrochemically active materials, such as metals, metal oxides and sulfides, which have been widely utilized for lithium storage, these materials still encounter unsatisfied electrochemical performances including low reversible capacity, slow charge-discharge capability and poor cycle performance. Here, we demonstrate a simple approach to fabricate one-dimensional CoO nanowires vertically aligned on a 3D graphene network (denoted as a 3D CoO/graphene network) via a wet chemistry process. The resulting CoO/graphene network possesses an interconnected graphene network, hierarchical pores and a carpet-like structure. This unique network can (1) facilitate the easy access of the electrolyte, (2) prevent the aggregation of CoO nanowires, (3) accommodate the volume change of CoO during the cycle processes, (4) maintain a high electrical conductivity for the overall electrode and (5) give rise to a high content of CoO in the composite (∼92 wt%). As a result, the 3D CoO/graphene network can be directly used as an anode material without any binder or conductive additives for lithium storage, and it exhibits a high capacity of 857 mAh g(-1), an excellent rate capability and good cycle performance. We believe that such a simple but efficient protocol will provide a new pathway for the fabrication of various 3D metal or metal oxide-graphene networks for wide applications in such fields as energy storage, sensors and catalysts.