With the rapid development of information technology on the Internet and the establishment of new online media platforms, it has played a great role in the delivery of information and the reception ...of content. The new media have profoundly influenced people’s lives in terms of the way they communicate, the construction of ideas and the execution of processes. This has not only enriched the ways in which news is disseminated, but has also opened up wider avenues and channels for news reporting. Since 2009, Bilibili has grown into a representative domestic secondary platform which is a high-density group of young internet users. The development and dissemination of social events that cater to the moods and emotions of young people can also serve to moderate cultural tensions to some extent, but, if used poorly, can be counterproductive. It is important to pay attention to the issue of culture, both to prevent pan-entertainment and to achieve cultural identity. In the face of online public opinion, government news media should change their previous negative attitude and adopt new and timely methods of response. The correct way to guide public opinion in hot events is a problem that the news media has to face and urgently needs to solve.
Fatigue resistance is a crucial requirement to the novel high-entropy alloys when they come to engineering applications, as many metal structures used in practice are failed by cyclic loading. Here, ...a thorough analysis of the information on the low-cycle fatigue, high-cycle fatigue, crack-growth rates, and fatigue mechanisms in the high-entropy alloy literature unveils a guideline through which the discovery and design of fatigue-resistant high-entropy alloys can be facilitated. Overall, multi-phase alloys, particularly the metastable ones, are favorable to fatigue resistance over single-phase alloys. Suggestions are proposed in the end to accelerate the discovery and design of candidates for fatigue-resistant applications.
At present, highway transportation is the main mode of transportation in China, but highway transportation has the problem of high cost, energy consumption and pollution. Although China has put ...forward the development policy of public transit railway, it still needs some time to achieve this goal. This paper studies the traffic structure from the middle level; combined with empirical analysis, it is concluded that railway transport has a greater impact on national income than road transport; the existing problems and causes of China's transportation structure are analyzed and the optimization policies are put forward.
Owing to the reduced defects, low cost, and high efficiency, the additive manufacturing (AM) technique has attracted increasingly attention and has been applied in high-entropy alloys (HEAs) in ...recent years. It was found that AM-processed HEAs possess an optimized microstructure and improved mechanical properties. However, no report has been proposed to review the application of the AM method in preparing bulk HEAs. Hence, it is necessary to introduce AM-processed HEAs in terms of applications, microstructures, mechanical properties, and challenges to provide readers with fundamental understanding. Specifically, we reviewed (1) the application of AM methods in the fabrication of HEAs and (2) the post-heat treatment effect on the microstructural evolution and mechanical properties. Compared with the casting counterparts, AM-HEAs were found to have a superior yield strength and ductility as a consequence of the fine microstructure formed during the rapid solidification in the fabrication process. The post-treatment, such as high isostatic pressing (HIP), can further enhance their properties by removing the existing fabrication defects and residual stress in the AM-HEAs. Furthermore, the mechanical properties can be tuned by either reducing the pre-heating temperature to hinder the phase partitioning or modifying the composition of the HEA to stabilize the solid-solution phase or ductile intermetallic phase in AM materials. Moreover, the processing parameters, fabrication orientation, and scanning method can be optimized to further improve the mechanical performance of the as-built-HEAs.
Magnetic materials with excellent performances are desired for functional applications. Based on the high-entropy effect, a system of CoFeMnNiX (X = Al, Cr, Ga, and Sn) magnetic alloys are designed ...and investigated. The dramatic change in phase structures from face-centered-cubic (FCC) to ordered body-centered-cubic (BCC) phases, caused by adding Al, Ga, and Sn in CoFeMnNiX alloys, originates from the potent short-range chemical order in the liquid state predicted by ab initio molecular dynamics (AIMD) simulations. This phase transition leads to the significant enhancement of the saturation magnetization (Ms), e.g., the CoFeMnNiAl alloy has Ms of 147.86 Am2/kg. First-principles density functional theory (DFT) calculations on the electronic and magnetic structures reveal that the anti-ferromagnetism of Mn atoms in CoFeMnNi is suppressed especially in the CoFeMnNiAl HEA because Al changes the Fermi level and itinerant electron-spin coupling that lead to ferromagnetism.
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In this study, solidification microstructure of fine primary silicon being uniformly distributed on single αAl matrix was obtained when adding Cu–9 wt%P alloy to an Al–10 wt%Si alloy melt or an Al–20 ...wt%Si alloy melt, stirring at 200 r/min for 12 min and cooling at the cooling rate of 16.3 K·s−1. The change law of silicon phase size with cooling rate and modified treatment parameters was determined by examining the solidification microstructures. It was found that ultrafine AlP was easily swallowed by primary silicon when the cooling rate was slow. The formation mechanism of superfine AlP particles, the growth process of αAl phase around primary silicon and the disappearance process of eutectic silicon were researched under intense stirring of the melt during the Cu–9 wt%P alloy modification. Moreover, the conditions under which fine primary silicon was uniformly distributed in single αAl matrix in hypereutectic Al-Si alloy were put forwarded. Finally, the formation mechanism of the solidification microstructure without eutectic Si in hypereutectic Al-Si alloy was analyzed.
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•Fine primary silicons uniformly being distributed on single αAl matrix are obtained in Al-20 wt%Si alloy.•Formation mechanism without eutectic silicon in hypereutectic Al–Si alloy was analyzed.•Conditions fine primary silicons are uniformly distributed in single αAl matrix in hypereutectic Al-Si alloy were put forwarded.•Change law of silicon phase size with cooling rate and modified treatment parameters was determined.
Understanding the effect of temperature variation on the microstructural evolution is particularly important to refractory high-entropy alloys (RHEAs), given their potential high-temperature ...applications. Here, we experimentally investigated the grain-growth behavior of the HfNbTaZrTi RHEAs during recrystallization at temperatures from 1,000 to 1,200 °C for varied durations, following cold rolling with a 70% thickness reduction. Following the classical grain-growth kinetics analysis, two activation energies are obtained: 205 kJ/mol between 1,000 and 1,100 °C, and 401 kJ/mol between 1,100 and 1,200 °C, which suggests two mechanisms of grain growth. Moreover, the yield strength – grain size relation was found to be well described by the Hall-Petch relation in the form of σy=942+270D−0.5. It was revealed that the friction stress, 942 MPa, in the HfNbTaZrTi HEA is higher than that of tungsten alloys, which indicates the high intrinsic stress in the BCC-RHEA. The coefficient, 270 MPa/μm −1/2, is much lower than that in the 316 stainless steel and Al0.3CoCrFeNi HEAs, which indicates low grain-boundary strengthening.
•HfNbTaTiZr HEA with a 70% cold-rolled reduction was annealed from 1000 from 1200 °C.•Grain-growth exponent and activation energy were obtained by grain-growth kinetic.•Yield strength – grain size relation was described by the Hall-Petch relation.•A high friction stress is found in the HfNbTaZrTi HEA.
Abstract
The dense stroma of desmoplastic tumor limits nanotherapeutic penetration and hampers the antitumor immune response. Here, we report a denaturation-and-penetration strategy and the use of ...tin monosulfide nanoparticles (SnSNPs) as nano-sonosensitizers that can overcome the stromal barrier for the management of desmoplastic triple-negative breast cancer (TNBC). SnSNPs possess a narrow bandgap (1.18 eV), allowing for efficient electron (e
−
)-hole (h
+
) pair separation to generate reactive oxygen species under US activation. More importantly, SnSNPs display mild photothermal properties that can in situ denature tumor collagen and facilitate deep penetration into the tumor mass upon near-infrared irradiation. This approach significantly enhances sonodynamic therapy (SDT) by SnSNPs and boosts antitumor immunity. In mouse models of malignant TNBC and hepatocellular carcinoma (HCC), the combination of robust SDT and enhanced cytotoxic T lymphocyte infiltration achieves remarkable anti-tumor efficacy. This study presents an innovative approach to enhance SDT and antitumor immunity using the denaturation-and-penetration strategy, offering a potential combined sono-immunotherapy approach for the cancer nanomedicine field.
Nanoindentation tests were performed to investigate the nano-scale plastic deformation in the Al0.5CoCrCuFeNi high entropy alloys at room temperature (RT) and 200 °C, respectively. Serrated plastic ...flow, manifested as discrete bursts of plasticity on the load-displacement curves, was observed for both temperatures during the loading period, and its behavior and dependence on the temperature was analyzed from the experimental perspective. Creep occurred during the nanoindentation holding period and exhibited very large stress exponent, implying that the dislocation glide-climb is the dominant mechanism. The creep simulations with a two-layer viscoplastic model further revealed that the deformation at a higher temperature (e.g., 200 °C) featured a greater and faster-growing plastic zone underneath the indenter, implying more pronounced dislocation activities.
•Nanoindentation tests were performed in the Al0.5CoCrCuFeNi HEA RT and 200 °C.•Serrated plastic flow was found at both temperature.•Serrated flow was analyzed by the mean-field theory.•Creep behavior was dominated by the glide-climb mechanism.•The creep simulation was performed based on viscoplastic model.
What is known and objective
Edaravone is a new antioxidant and hydroxyl radical scavenger. Although there is evidence that it improves clinical outcomes of patients with acute ischaemic stroke (AIS), ...it is not yet widely accepted for treatment of AIS in Western countries. We further investigated the efficacy and safety of edaravone through this meta‐analysis of randomized controlled clinical trials (RCTs).
Method
Pubmed, Embase, Web of Science and Cochrane Library were screened up to December 2020 for original articles from SCI journals that published in English. RCTs that compared edaravone versus placebo or no intervention in adult patients and reported the efficacy or safety of edaravone were regarded as eligible. Mortality was regarded as the primary outcome and the improvement of neurological impairment was regarded as the secondary outcome. Safety evaluation was conducted according to the incidence of adverse events. Review Manager 5.3 was employed to perform the assessment of the risk of bias and data synthesis. The Cochrane risk of bias tool for randomized controlled trials was employed to assess the risk of bias.
Results and discussion
Seven randomized controlled trials with 2069 patients were included. For the incidence of mortality, the pooled RR for studies that evaluated edaravone after three‐month follow‐up was 0.55 (95% Cl, 0.43‐0.7, I2 = 0, P < 0.01). The pooled RR for improvement of neurological impairment at the three months follow‐up was 1.54 (95% CI, 1.27‐1.87, I2 = 0, P < 0.01) in four RCTs. On subgroup analysis of studies that were conducted in Asia, the RR was 1.56 (95% CI, 1.27‐1.90, I2 = 0%; P < 0.01); the pooled RR for studies that conducted in Europe was 1.32 (95% CI, 0.64‐2.72; P = 0.45); the pooled RR for studies that used edaravone for two weeks was 1.42 (95% CI, 1.10 to 1.83, I2 = 0%; P < 0.01); the pooled RR for studies that used edaravone for one week was 1.64 (95% CI, 1.24‐2.16, I2 = 0%; P < 0.01); the pooled RR for studies that conducted in patients with mean age equal to or over 60 years was 1.52 (95% CI, 1.24‐1.87, I2 = 0%; P < 0.01); and the pooled RR for studies that conducted in patients with mean age less than 60 was 1.80 (95% CI, 1.05‐3.08, I2 = 0%; P = 0.03). For the incidence of any treatment‐related adverse events, the pooled RR for studies that evaluated edaravone during treatment was 0.83 (95% CI, 0.51‐1.34, I2 = 0, P = 0.43). The difference of the incidence of any treatment‐related adverse events between two groups was not statistically significant.
What is new and conclusion
The limited studies indicate that edaravone can improve neurological impairment with a survival benefit at three‐month follow‐up, regardless of the mean age and course of treatment. It is worthy of promotion in the clinical treatment of AIS in Asian countries. More well‐designed RCTs with larger sample sizes are needed to determine the benefits of edaravone in patients from Western countries.
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