Formability of peak-aged AA 7075-T6 sheet across a temperature range from room temperature to 250°C as well as post-forming microstructure/property were investigated in this paper. It showed that the ...optimized formability was obtained at 200°C, due to the higher ductility and work hardening capacity at this temperature. The dominant phases in 7075-T6, 200°C warm formed, and 250°C warm formed samples were fine η′ and GP zones, well-developed η′, and coarser η phases, respectively. Post-forming and post-paint-baking mechanical property of 7075 samples was closely associated with those corresponding microstructures. Specifically, 200°C warm forming caused limited coarsening of matrix precipitates (MPts) and generated a certain number of dislocations, due to the combined effect of the decreased precipitation strengthening and increased dislocation strengthening, the inherent high strength of 7075-T6 was perfectly preserved after 200°C forming. However, 250°C forming led to severely decreased hardness due to the sharply coarsened MPts. Furthermore, the paint-baking treatment exerted little influence to MPts, grain boundary precipitates (GBPs) and precipitate free zone (PFZ), thus the hardness loss caused by paint-baking was unobvious. Overall, 200°C was the appropriate temperature under which the peak-aged 7000 alloys exhibited enhanced formability and maintained high post-forming strength, after paint baking, the drawn component possessed microstructure/property similar to those of retrogression and re-aged (RRA) samples.
The majority of breast cancers express the estrogen receptor (ERα) and agents targeting this pathway represent the main treatment modality. Endocrine therapy has proven successful in the treatment of ...hormone-responsive breast cancer since its early adoption in the 1940s as an ablative therapy. Unfortunately, therapeutic resistance arises, leading to disease recurrence and relapse. Recent studies increased our understanding in how changes to the chromatin landscape and deregulation of epigenetic factors orchestrate the resistant phenotype. Here, we will discuss how the epigenome is an integral determinant in hormone therapy response and why epigenetic factors are promising targets for overcoming clinical resistance.
The electric vehicle (EV) industry is growing rapidly at the moment. However, refueling an electric vehicle could be a time-consuming process. This was the case until the emergence of battery ...swapping technology. Using the battery swapping technology developed by EV manufacturer NIO as an example, this paper aims to analyze the history, current state, and future of the technology. In order to conduct the analysis, data provided by the EV industry is closely examined, as data from NIO is compared with data from other aspects of the EV industry. Through the analysis, it is found that the battery swapping technology provides efficiency and convenience, but is of high cost and lacks adequate infrastructure on a larger scale. Battery swapping technology has a promising future, but in order to effectively compete with conventional technologies such as charging stations, it would be beneficial for the technology to cut down on cost and expand its infrastructure.
Significantly enhanced in-vitro corrosion resistance and biocompatibility to nano-grained pure titanium (Ti)
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•Nanocrystalline layer on pure Ti surface was fabricated by ...SFT.•Improvement of corrosion resistance for NG Ti was due to the thickness and homogeneity of passive film.•Enhancement of cellular response for NG Ti was attributed to nano-topography and higher hydrophilicity.•The improvement in anti-corrosion properties and biocompatibility of NG Ti is linked to its unique structure.
In the present study, a nano-grained (NG) surface layer on a commercial pure (Grade-2) titanium sheet was achieved by means of sliding friction treatment. The surface characteristics, in vitro corrosion behavior and biocompatibility of NG Ti were investigated, compared with those of the conventional coarse-grained (CG) substrate. The protective passive film on NG Ti surface is thicker than that on CG Ti, leading to its enhanced biological corrosion resistance in simulated body fluid (SBF) solution. In addition, NG Ti shows a much higher hydrophilicity and nano-roughness, which is related to its significantly improved cell attachment, spreading, proliferation and maturation relative to CG Ti. The enhanced biological anti-corrosion properties and biocompatibility render NG Ti a promising biomaterial for implants.
The seafloor is recognized as one of the major sinks for microplastics (MPs). However, to date there have been no studies reported the MP contamination in benthic organisms from the Arctic and ...sub-Arctic regions. Therefore, this study provided the first data on the abundances and characteristics of MPs in a total of 413 dominant benthic organisms representing 11 different species inhabiting in the shelf of Bering and Chukchi Seas. The mean abundances of MP uptake by the benthos from all sites ranged from 0.02 to 0.46 items g−1 wet weight (ww) or 0.04–1.67 items individual−1, which were lower values than those found in other regions worldwide. The highest value appeared at the northernmost site, implying that the sea ice and the cold current represent possible transport mediums. Interestingly, the predator A. rubens ingested the maximum quantities of MPs, suggesting that the trophic transfer of MPs through benthic food webs may play a critical role. Fibers constituted the major type (87%) in each species, followed by film (13%). The colors of fibers were classified as red (46%) and transparent (41%), and the film was all gray. The predominant composition was polyamide (PA) (46%), followed by polyethylene (PE) (23%), polyester (PET) (18%) and cellophane (CP) (13%). The most common sizes of MPs concentrated in the interval from 0.10 to 1.50 mm, and the mean size was 1.45 ± 0.13 mm. Further studies about the temporal trends and detrimental effects of MPs remain to be carried out in benthic organisms from the Arctic and sub-Arctic regions.
•First investigation of microplastics (MPs) in benthic organisms from the Arctic.•MP levels were lower than those found in other regions worldwide.•The organisms from the northernmost site possessed the highest MP abundances.•The predator starfish Asterias rubens ingested the maximum quantities of MPs.•Fibers constituted the major type of MPs in each detected species.
Carbon nanotube (CNT) can work as excellent saturable absorber (SA) due to its advantages of fast recovery, low saturation intensity, polarization insensitivity, deep modulation depth, broad ...operation bandwidth, outstanding environmental stability, and affordable fabrication. Its successful application as SA has promoted the development of scientific research and practical application of mode-locked fiber lasers. Besides, mode-locked fiber laser constitutes an ideal platform for investigating soliton dynamics which exhibit profound nonlinear optical dynamics and excitation ubiquitous in many fields. Up to now, a variety of soliton dynamics have been observed. Among these researches, CNT-SA is a key component that suppresses the environmental perturbation and optimizes the laser system to reveal the true highly stochastic and non-repetitive unstable phenomena of the initial self-starting lasing process. This review is intended to provide an up-to-date introduction to the development of CNT-SA based ultrafast fiber lasers, with emphasis on recent progress in real-time buildup dynamics of solitons in CNT-SA mode-locked fiber lasers. It is anticipated that study of dynamics of solitons can not only further reveal the physical nature of solitons, but also optimize the performance of ultrafast fiber lasers and eventually expand their applications in different fields.
With the rapid development of new energy vehicles, the users have an increasing demand for charging piles. It is generally believed that the charging pile is a kind of practical product, and it only ...needs to realize the charging function. However, as a product, the shape design of the charging pile will directly affect the user experience, thus affecting product sales. Therefore, in the face of increasingly fierce market competition, when designing the shape of charging piles, it is necessary to adopt the traditional evaluation method and human physiological cognitive characteristics to evaluate the shape of charging piles more objectively. From the user's point of view, using the electroencephalogram (EEG) of the user, with the help of the multifractal detrended fluctuation analysis (MF-DFA) method, this paper comprehensively analyzes the differences in emotional cognitive characteristics between two kinds of charging piles, namely, the charging pile with a curved appearance design and the charging pile with square appearance design. The results show that there are significant differences in human physiological cognitive characteristics between two kinds of charging piles with different shapes. And different shapes of charging piles have different physiological cognitive differences for users. When designing charging pile product shapes, human beings can objectively evaluate the product shape design according to the physiological cognition differences of users, so as to optimize the charging pile product shape design.
The strength and corrosion resistance of 7000 series (Al-Zn-Mg-Cu) alloys seldom co-exist and are often trade-off with each other. In present study, an alternative surface nanocrystallization ...technique called sliding friction treatment (SFT) was adopted to successfully generate a gradient nanostructured layer on coarse-grained (CG) peak-aged AA 7075-T6 alloy sheet. The grain size on the topmost surface of SFTed sample was extremely reduced to nano-scale (average grain size: ∼56.2 nm). Excitingly, the SFTed 7075 possessed simultaneously improved mechanical strength and inter-granular corrosion (IGC) resistance relative to the CG counterpart. Specifically, both ultimate tensile strength (UTS) and yield strength (YS) of SFTed sample are even ∼ 40 MPa higher than those of untreated peak-aged CG sample. Meanwhile, the IGC test results demonstrate that the average maximum corrosion depth is considerably reduced from ∼179 μm to ∼40 μm after SFT treatment. The obviously refined grains account for the enhanced strength, while the improved IGC resistance should benefit from SFT-induced grain refinement, elimination of both grain boundary precipitates (GBPs) and precipitates free zones (PFZs) along the grain boundaries of SFT-induced nanocrystalline. Our results demonstrate that SFT processing offers a design pathway to fabricating 7000 alloys with modified strength-IGC resistance synergy.
•A nano-grained layer on 7075 was fabricated by sliding friction treatment (SFT).•The SFTed 7075 exhibited superior strength-ductility combination.•The SFTed 7075 exhibited enhanced strength and inter-granular corrosion resistance.
Abstract
The rapid development of high-speed rail requires copper contact wire that simultaneously possesses excellent electrical conductivity, thermal stability and mechanical properties. ...Unfortunately, these are generally mutually exclusive properties. Here, we demonstrate directional optimization of microstructure and overcome the strength-conductivity tradeoff in copper wire. We use rotary swaging to prepare copper wire with a fiber texture and long ultrafine grains aligned along the wire axis. The wire exhibits a high electrical conductivity of 97% of the international annealed copper standard (IACS), a yield strength of over 450 MPa, high impact and wear resistances, and thermal stability of up to 573 K for 1 h. Subsequent annealing enhances the conductivity to 103 % of IACS while maintaining a yield strength above 380 MPa. The long grains provide a channel for free electrons, while the low-angle grain boundaries between ultrafine grains block dislocation slip and crack propagation, and lower the ability for boundary migration.
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