| 1. |
- Tian, Shiwei, et al.
(författare)
-
Investigation on the microstructure evolution and dynamic recrystallization mechanisms of TiAl alloy at elevated temperature
- 2021
-
Ingår i: Journal of Materials Research and Technology. - : Elsevier BV. - 2238-7854 .- 2214-0697. ; 14, s. 968-984
-
Tidskriftsartikel (refereegranskat)abstract
- The flow stress–strain curves appear to be sensitive to deformation conditions. The ratio of critical strain to peak strain εc/εp follows a linear relationship except when the temperature is 1240 °C and the strain rate is 0.001 s−1. During the deformation, the fragmentation and decomposition of γ/α2 lamellae are related to recrystallization of α2 and γ laths in the lamellae and the γ → α2 phase transformation, the former depends on dislocation slip and twinning, and the latter is related to temperature, local stress concentration and diffusion time. As for the recrystallization mechanisms, the γ phase is discontinuous dynamic recrystallization (DDRX) mode, while the α2 phase relies on continuous dynamic recrystallization (CDRX) mode. The β phase has more low-angle grain boundaries (LAGB) during deformation, indicating the continuous coordinated deformation, and this explains the enlarged hot working window of the TiAl alloy (1165–1240 °C/0.001 ~ 1 s−1 and 1120–1165 °C/0.001–0.4 s−1).
|
|
| 2. |
- Bai, Qiao, et al.
(författare)
-
Effect of proinflammatory S100A9 protein on migration and proliferation of microglial cells
- 2023
-
Ingår i: Journal of Molecular Neuroscience. - : Springer Nature. - 0895-8696 .- 1559-1166. ; 73:11-12, s. 983-995
-
Tidskriftsartikel (refereegranskat)abstract
- Alzheimer’s disease (AD) is a multifactorial disease affecting aging population worldwide. Neuroinflammation became a focus of research as one of the major pathologic processes relating to the disease onset and progression. Proinflammatory S100A9 is the central culprit in the amyloid-neuroinflammatory cascade implicated in AD and other neurodegenerative diseases. We studied the effect of S100A9 on microglial BV-2 cell proliferation and migration. The responses of BV-2 cells to S100A9 stimulation were monitored in real-time using live cell microscopy, transcriptome sequencing, immunofluorescence staining, western blot analysis, and ELISA. We observed that a low dose of S100A9 promotes migration and proliferation of BV-2 cells. However, acute inflammatory condition (i.e., high S100A9 doses) causes diminished cell viability; it is uncovered that S100A9 activates TLR-4 and TLR-7 signaling pathways, leading to TNF-α and IL-6 expression, which affect BV-2 cell migration and proliferation in a concentration-dependent manner. Interestingly, the effects of S100A9 are not only inhibited by TNF-α and IL-6 antibodies. The addition of amyloid-β (Aβ) 1–40 peptide resumes the capacities of BV-2 cells to the level of low S100A9 concentrations. Based on these results, we conclude that in contrast to the beneficial effects of low S100A9 dose, high S100A9 concentration leads to impaired mobility and proliferation of immune cells, reflecting neurotoxicity at acute inflammatory conditions. However, the formation of Aβ plaques may be a natural mechanism that rescues cells from the proinflammatory and cytotoxic effects of S100A9, especially considering that inflammation is one of the primary causes of AD.
|
|
| 3. |
- Huang, Ivy, et al.
(författare)
-
High performance dual-electrolyte magnesium-iodine batteries that can harmlessly resorb in the environment or in the body
- 2022
-
Ingår i: Energy & Environmental Science. - : Royal Society of Chemistry (RSC). - 1754-5692 .- 1754-5706. ; 15:10, s. 4095-4108
-
Tidskriftsartikel (refereegranskat)abstract
- Batteries represent the dominant means for storing electrical energy, but many battery chemistries create waste streams that are difficult to manage, and most possess toxic components that limit their use in biomedical applications. Batteries constructed from materials capable of complete, harmless resorption into the environment or into living organisms after a desired period of operation bypass these disadvantages. However, previously reported eco/bioresorbable batteries offer low operating voltages and modest energy densities. Here, we introduce a magnesium-iodine chemistry and dual (ionic liquid/aqueous) electrolyte to overcome these limitations, enabling significant improvements in voltage, areal capacity, areal energy, areal power, volumetric energy, and volumetric power densities over any alternative. Systematic studies reveal key materials and design considerations. Demonstrations of this technology include power supplies for cardiac pacemakers, wireless environmental monitors, and thermal sensors/actuators. These results suggest strong potential for applications where commercial battery alternatives pose risks to the environment or the human body.
|
|
| 4. |
- Shiwei, Tian, et al.
(författare)
-
Effect of Mo Element on Microstructure and Mechanical Properties of TiAl Alloys
- 2022
-
Ingår i: Xiyou jinshu cailiao yu gongcheng. - : NORTHWEST INST NONFERROUS METAL RESEARCH. - 1002-185X. ; 51:7, s. 2336-2343
-
Tidskriftsartikel (refereegranskat)abstract
- Four TiAl alloys with different Mo contents were designed, and the microstructure and mechanical properties of these MoTiAl alloys were studied by scanning electron microscope, nanoindentation, and hot compression simulation methods. Results show that with increasing the Mo content, the content of. phase is gradually decreased, while that of beta phase is gradually increased. The Mo element mainly exists in the form of beta phase in the TiAl alloy. During the hot isostatic pressing process, the Mo element is diffused from the. and a 2 phases to the beta phase. The nanoindentation hardness of Mo-TiAl alloy reaches the maximum when the Mo content is 1.59at%, and it is negatively correlated with the interlamellar space. As the content of Mo element increases, the flow stress of Mo-TiAl alloys decreases, and the TiAl alloys with 2.11at% and 3.94at% Mo addtion have poor plasticity due to the Al element segregation.
|
|
| 5. |
- Shiwei, Tian, et al.
(författare)
-
Oxidation resistance of TiAl alloy improved by hot-pack rolling and cyclic heat treatment
- 2021
-
Ingår i: Materials Characterization. - : Elsevier BV. - 1044-5803 .- 1873-4189. ; 178
-
Tidskriftsartikel (refereegranskat)abstract
- The isothermal oxidation behavior of two TiAl alloys (as-HIP and as-RHT) were compared to explain the effect of microstructure on the oxidation resistance of TiAl alloy. After hot-pack rolling and cyclic heat treatment, the size of lamellar colonies was refined from 35.4 mu m to 21.5 mu m, and the beta/B2 phase was effectively removed. It is concluded that the as-RHT TiAl alloy has better oxidation resistance than the as-HIP TiAl alloy. The main reason is due to refinement of lamellar colony size, elimination of beta/B2 phase, uniform distribution of Nb and Mo, and the crushing of Y compounds.
|
|
| 6. |
- Tian, S., et al.
(författare)
-
Investigation of the Thermal Shock Behavior of Mo-Containing TiAl Alloys
- 2022
-
Ingår i: Advanced Engineering Materials. - : Wiley. - 1438-1656 .- 1527-2648. ; 24:3
-
Tidskriftsartikel (refereegranskat)abstract
- TiAl alloys undergo cyclic temperature changes during use, the process of which can be simulated by the thermal shock test. A systematic investigation of the thermal shock behavior of four Mo-containing TiAl alloys is conducted. The increase in Mo content from 1.0% to 4.0% causes the gradual decrease in the volume fraction of γ/α2 lamellar colony, while the volume fraction of equiaxed γ and βo phases gradually increases. At the same time, the thermal shock resistance of the TiAl alloys decreases as the Mo content increases. After thermal shock, cracks often occur within the lamellae and extend in a zigzag manner for TiAl−1.0Mo and TiAl−1.5Mo alloys. Their thermal shock resistance is enhanced by crack deflection, bridging, and microcrack shielding. For TiAl−2.0Mo and TiAl−4.0Mo alloys, cracks occur at the grain boundaries or within the γ phase and extend straight, with the result that these two alloys have worse thermal shock resistance than the other two alloys due to the limited effect of microcrack shielding. In addition, the microstructure stability of TiAl alloys after thermal shock is discussed, and there is a critical value of Mo content between 3.13% and 5.67%, which inhibits the βo → ω phase transition.
|
|
| 7. |
- Wang, Shu Min, 1963, et al.
(författare)
-
Novel Dilute Bismides for IR Optoelectronics Applications
- 2013
-
Ingår i: Asia Communications and Photonics Conference, ACP. - Washington, D.C. : OSA. - 2162-108X.
-
Konferensbidrag (refereegranskat)abstract
- III-V-Bi compounds reveal a number of attractive physical properties promising for novel IR optoelectronic applications [1,2] and have received considerable attention as witnessed by the dedicated international workshops on this topic in the consecutive past four years. The isoelectronic nature of Bi atoms in III-Vs induces strong interactions with the energy bands of host materials leading to large band-gap reduction, less temperature sensitive band-gap and large spin-orbit split band. So far the most studied material is Ga(N)AsBi, while other dilute bismides have also been reported recently. In this paper, we shall briefly review several novel bismides: GaSbBi, InSbiBi, InAsBi, InPBi and InGaAsBi, and the Bi surfactant effect from our group, all grown by molecular beam epitaxy (MBE).
|
|
| 8. |
- Yang, Yonggang, et al.
(författare)
-
Effects of the austenitizing temperature on the microstructure and mechanical properties in multiple-phase medium Mn steel
- 2019
-
Ingår i: Materials Research Express. - : IOP PUBLISHING LTD. - 2053-1591. ; 6:12
-
Tidskriftsartikel (refereegranskat)abstract
- Medium Mn steel (MMnS) is the good choice for car manufacturers to meet the requirements of reducing the weight of automobiles. Quenching & Partitioning (Q&P) process is an effective method to stabilize austenite in advanced steel, thus prompting the comprehensive mechanical properties of advanced steel. In this article, the Q&P process is applied to the MMnS to explore potential mechanical properties. The effect of austenitizing temperature, one of the significant parameters of Q&P process, on the microstructure and mechanical properties of MMnS was investigated. According to microstructural analyse results, all of the MMnS specimens processed by Q&P treatment with different austenitizing temperatures could obtain multi-phase microstructure, including alpha '-martensite, e-martensite and austenite. Furthermore, the highest volume fraction of austenite was observed in the MMnS processed by Q&P treatment at the austenitizing temperature of 920 degrees C. Due to the facilitated transformation-induced plasticity effect resulted from the high volume fraction of austenite with the austenitizing temperature of 920 degrees C, the MMnS obtained the high strength, high plasticity and sustaining work-hardening rate.
|
|
| 9. |
- Zhang, Xiaoyin, et al.
(författare)
-
Proinflammatory S100A9 stimulates TLR4/NF-κB signaling pathways causing enhanced phagocytic capacity of microglial cells
- 2023
-
Ingår i: Immunology Letters. - : Elsevier. - 0165-2478 .- 1879-0542. ; 255, s. 54-61
-
Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is the main cause of dementia, affecting the increasingly aging population. Growing evidence indicates that neuro-inflammation plays crucial roles, e.g., the association between AD risk genes with innate immune functions. In this study, we demonstrate that moderate concentrations of pro-inflammatory cytokine S100A9 regulate immune response of BV2 microglial cells, i.e., the phagocytic capacity, reflected by elevated number of 1 μm diameter Dsred-stained latex beads in the cytoplasm. In contrast, at high S100A9 concentrations, both the viability and phagocytic capacity of BV2 cells drop substantially. Furthermore, it is uncovered that S100A9 affects phagocytosis of microglia via NF-κB signaling pathways. Application of related target-specific drugs, i.e., IKK and TLR4 inhibitors, effectively suppresses BV2 cells’ immune responses. These results suggest that pro-inflammatory S100A9 activates microglial phagocytosis, and possibly contributes to the clearance of amyloidogenic species at the early stage of AD.
|
|
| 10. |
|
|
