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The traditional low-pressure sintering was optimized for the preparation of Ti(C0.5N0.5)-WC-Mo2C-TaC-Co-Ni cermets. Nitrogen was introduced into sintering system during different stages and with different pressures. The morphology and mechanical properties of cermets were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and measurements of transverse rupture strength (TRS), Vickers-hardness (HV) and fracture toughness (KIC). The degree of denitrification is directly related to the amount of η phase. When nitrogen is introduced into the sintering system, the amount of observed η phase decreases. When nitrogen is introduced during solid-state sintering with appropriate pressure, the core-rim structure is well developed. And TRS and hardness get enhanced while toughness tends to be deteriorated with the nitrogen pressure increasing. When nitrogen is introduced after the sintering temperature reaches 1 350 °C or at higher pressures, the volume fraction of η phase increases. Sintered with a nitrogen pressure of 1.0 kPa during 1 200–1 350 °C, the bulk materials possess enhanced mechanical properties, in which the TRS, HV, and KIC are 1 966 MPa, 1 583 MPa, and 9.08 MPa·m1/2, respectively.

Aberrant regulation of ubiquitination often leads to metabolic reprogramming in tumor cells. However, the underlying mechanisms are not fully understood. Here we demonstrate that OTUB2, an OTU deubiquitinase, is upregulated in colorectal cancer (CRC) and exacerbates the progression of CRC through modulating the aerobic glycolysis. Mechanistically, OTUB2 directly interacts with pyruvate kinase M2 (PKM2) and inhibits its ubiquitination by blocking the interaction between PKM2 and its ubiquitin E3 ligase Parkin, thereby enhancing PKM2 activity and promoting glycolysis. In response to glucose starvation stress, the effect of OTUB2 on PKM2 is enhanced, which confers metabolic advantage to CRC cells. Moreover, OTUB2 depletion reduces glucose consumption, lactate production, and cellular ATP production. OTUB2-knockout CRC cells exhibit attenuated proliferation and migration, as well as an elevated level of apoptosis and increased sensitivity to chemotherapy drugs. Furthermore, in vivo assays show that knockout of OTUB2 inhibits tumor growth in mice. Taken together, these findings reveal the critical role of OTUB2 in the regulation of glycolysis and illustrate the molecular mechanism underlying its role as a negative regulator of PKM2 ubiquitination in CRC, establishing a bridge between OTUB2-regulated PKM2 ubiquitination and altered metabolic patterns in CRC and suggesting that OTUB2 is a promising target for CRC treatment.

Pristine Cu2Te is a highly degenerate metallic-behaving semiconductor that exhibits poor thermoelectric performance due to its ultrahigh hole concentration derived from the intrinsically high concentration of cation vacancies. Here, through doping with Sn, the electronic transport properties of Cu2−xSnxTe are significantly promoted due to the hole concentration reduction stemming from more valence electrons being contributed by Sn; the thermal conductivity is simultaneously decreased for the same reason. Consequently, a record high zT of 1.5 was achieved in p-type Cu1.90Sn0.10Te at 1000 K, which is due to a synergistic optimization in power factor and thermal conductivity. Combined with the density functional theory (DFT) calculations, such an improvement could be mainly attributed to the increase in the density of states (DOS) in the valence band edge of Cu2−xSnxTe, which originated from the hybridization of the lone pair electrons of the Sn 5s orbital with the Cu 3d and Te 5p electrons. Additionally, transmission electron microscopy revealed the existence of a high density of twist boundaries and dislocations that may have enhanced the phonon scattering, therefore, contributing to the reduced thermal conductivity. This study explores a synergistic optimization strategy to simultaneously boost the power factor and suppress thermal conductivity, providing a feasible method to achieve high thermoelectric performance in intrinsically highly degenerate semiconductors with metallic behavior.

Crushing is a critical factor for the anisotropic NdFeB powders with high magnetic properties. However, the traditional crushing methods of disk-milling (DM) or impact crushing (IC), are difficult to obtain high-performance powders. Herein, a new method of preparing anisotropic powders with high performance was reported, which was through crushing the hot-deformed magnets perpendicular to c-axis direction (shear crushing, SC). The microstructure and alignment of the magnets were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The results indicated that the cracks mainly extended along the Nd-rich grain boundary phase and/or the binding interface of ribbons. It not only could protect the magnetic phase from being damaged, but also could keep the grains integrated. Therefore, shear crushing was an effective method for the preparation of high-performance anisotropic powders and then to fabricate the bonded magnets with Br=9.0 kGs, Hci=10.48 kOe and (BH)max=17.7 MGOe.

The single-phase (Cr,V)2(C,N) solid solution powders were fabricated via carbothermal reduction-nitridation (CRN) processing technique. The effects of heat treatment temperature, nitrogen pressure and carbon proportion were experimentally studied in detail by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and thermal analysis. The chemical transformations of vanadium and chromium compounds were as follows: precursors → V2O3, Cr2O3 → Cr3C2, Cr2O3, (Cr,V)2(C,N) → (Cr,V)2(C,N). When the heat-treated temperature was below 1200 °C, chromium oxides didn’t completely react. However, higher temperature ∼1300 °C could not only lead to the segregation of some nitrides and carbon black, but also to the occurrence of fiber-bridged particles. The system nitrogen pressure over 0.03 MPa would cause a subtle transformation of (Cr,V)2(C,N) to VCrN2. When the carbon proportion was below 15 wt%, the oxides could not be completely reduced, while when the carbon proportion was above 15.5 wt%, some undesired carbides, like Cr23C6 and Cr3C2, would form. Ultimately, the homogeneously distributed pure-phase (Cr,V)2(C,N) spherical particles with the average size of ∼1.5 μm were obtained at the optimal conditions of the treatment of precursors at 1200 °C for 1 h with the nitrogen pressure of 0.03 MPa and carbon content of 15.5 wt%. The chemical composition of the solid solution with the optimal process could be drawn as (Cr0.85V0.15)2(C0.57N0.43). Thermal processing precursors method shows the advantages of lower synthesis temperature, shorter period and finer particles when comparing with the conventional preparations.

Anisotropic magnets were obtained by hot deformation with the partial crystallized precursor prepared via spark-plasma sintering (SPS). Amorphous powders with the nominal composition of Nd28.72FebalCo5.66Ga0.59B0.92 (wt%) were used as the starting material. The results show that the amorphous powders would suffer varying degrees of crystallization even below the crystallization point during the SPS process under high pressure. And the pre-crystallized grains in precursors have great impacts on the microstructure and magnetic properties of the hot-deformed magnets. The final obtained anisotropic magnets exhibit homogeneous microstructure consisting of well-aligned and platelet-shaped Nd2Fe14B grains without abnormal growth. It can be found that a reasonable proportion of pre-crystallized gains could promote the preferential orientation in the magnet, leading to the achievement of optimal magnetic properties among the magnets with identical composition and best magnetic performance is achieved in the magnet hot deformed from the 490 °C high-pressure hot-pressed precursor.

Homogeneous solid-solution (Ti, Ta, Nb,W)(C,N) powders were synthesized through carbothermal reduction-nitridation method. The effects of (Ti, Ta, Nb,W)(C,N) powders on the microstructure, mechanical properties and corrosion resistance of WC-10Co cemented carbides were investigated using XRD, SEM, electrochemical test and mechanical properties tests. The results showed that cemented carbides with pre-alloyed powder addition had a similar microstructure appearance: weak core/rim structure consisting of solid-solution phase embedded in the WC-Co system. The black core and gray rim, both of which contained similar elements, were identified as (Ti, Ta, Nb,W)(C,N), but the latter contained higher amount of heavy elements. With the addition of (Ti, Ta, Nb,W)(C,N) powders, the density, transverse rupture strength and fracture toughness of samples decreased monotonously. However, the hardness rose sharply at first, reached a peak at 15 wt% solid-solution addition, then slightly decreased, and finally increased again. Results also revealed that increasing (Ti, Ta, Nb,W)(C,N) made the open circuit potential (OCP) in 1 M sulphuric acid solution more negative than that of WC-Co, and all specimens exhibited pseudo-passivation phenomenon in the test solution. In addition, increasing pre-alloyed powders led to decreasing corrosion current density, which implies that (Ti, Ta, Nb,W)(C,N) could remarkably improve the corrosion resistance of WC-Co cemented carbides.

A novel method to synthesise sub-micron FeWB powders is proposed, by which pure-phase FeWB powders with a particle size of ∼500 nm were successfully obtained. This method consists of three steps: water atomisation, annealing treatment and acid dissolution of the matrix. Systematic characterisation was carried out throughout the preparing process to determine the detail phase evolution, chemistry features as well as the changes in particle size. It was found out that the as-atomised powders consisted of only α-Fe solid solution where W and B atoms are dissolved as solute atoms. And the annealing treatment could facilitate the precipitation of W and B atoms from the matrix to form tiny dispersive continuous net-like precipitates. Analyses showed that Fe6W6C, Fe3W3C and FeWB were precipitated in sequence during the annealing process. And following the chemical treatment, the α-Fe matrix and surface oxide layers could be completely removed and FeWB powders could be successfully recovered.

A highly efficient facile method was used to synthesize Cu2Te via spark plasma sintering (SPS) of high-energy ball-milled elemental powders, followed by annealing, which dramatically reduced the whole process time. The multiple phase transitions of Cu2Te over an extensive temperature range were determined using a combination of high temperature X-ray diffraction (HTXRD) and differential scanning calorimetry (DSC). This merit endows Cu2Te with the ability to trigger multiple critical scatterings from room temperature up to 900 K. Microscopic investigation showed that the Cu2Te prepared by this rapid method possesses tiny dispersive precipitates, with sizes in the range of 50–100 nm, that could serve as obstacles for the transfer of mid-wavelength phonons. As a result, a ZT value of ∼0.52 at 1000 K was obtained for the sample annealed for 10 h after SPS.

Three kinds of (Ti, M)(C1−x , N x ) (M = Ta, Nb, W) quaternary solid-solution powders with various nitrogen contents were synthesized by carbothermal reduction–nitridation (CRN) process. Effect of nitrogen content on the microstructure and mechanical properties of WC–(Ti, M)(C1−x , N x )–Co cemented carbides fabricated by sinter-hot isostatic pressing (HIP) were systematically investigated in this paper. The results show that the nitrogen content in the carbonitride raw powders strongly influences the morphology, the grain size and the compositions of the cemented carbides. All the cemented carbides with different nitrogen contents have a similar microstructural appearance: weak core–rim structure consisting of solid-solution phase embedded in WC–Co system. It is also observed that the carbonitride solid solution could somewhat reduce the WC grain growth, and the effectiveness of refining and the rim thickness are sensitively related to the nitrogen content of (Ti, M)(C1−x , N x ) solid solutions. In addition, with an increase in the nitrogen content, mechanical properties of these hard metals are enhanced, which were discussed in terms of the constituent, the microstructure and the solution behavior of the carbonitride solid solutions.