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The chiral P,N,N‐ligands represented a new type of tridentate ligand developed in recent years and displayed wide utilities in asymmetric catalysis. In the past decades, numerous chiral P,N,N‐ligands with ferrocene, phenethylamine and spiro backbones were synthesized by addition of an aminopyridine, imidazole or diamines coordinating group. These chiral tridentate P,N,N‐ligands showed excellent performance in the ruthenium, iridium, manganese, or cobalt‐catalyzed asymmetric hydrogenations. A wide range of substrates, including simple ketones, α‐halogenated ketones, α‐hydroxy ketones, α‐ or β‐amino keto‐ ones, α‐, γ‐, or δ‐keto acids, α‐ or β‐keto amides, β‐ or δ‐keto esters, α‐ or β‐enones, olefins, imines, quinolines and indoles, could be hydrogenated to afford the corresponding chiral products with high yields and enantioselectivities. In this review, progress on the asymmetric hydrogenation of C=O, C=N, C=C bonds with chiral tridentate P,N,N‐ligands was summarized. [ABSTRACT FROM AUTHOR]

The finite‐time nonlinear placement problem of networked Euler‐Lagrange systems (NELSs) is discussed in this paper. The problem is reformulated into a finite‐time aggregate game under an undirected graph. Then, several novel practical gradient‐based finite‐time hierarchical (GFTH) algorithms composed of a game layer, a Nash equilibrium (NE) seeking layer, and a control layer are proposed. Specifically, the game layer employs an aggregate function to reach a consensus on the potential aggregate value which is adopted by a gradient‐based finite‐time method to tackle the finite‐time NE seeking problem in the NE seeking layer, and then, the tracking problem is realized in the control layer. The convergence results are established by a nonsmooth Lyapunov function. In addition, the versatility of the GFTH algorithms is shown by extending to address the task‐space control problem of NELSs. The effectiveness of the proposed algorithms is illustrated via simulations. [ABSTRACT FROM AUTHOR]

Purpose: Technostress is becoming one of the main challenges among employees in the increasingly digital work context. Following the job demands-resources (JD-R) theory, this study aims to understand how technostress (e.g. techno-overload, techno-complexity, techno-insecurity and techno-uncertainty) decreases employees' work well-being through exhausting one's emotional and physical resources (i.e. work exhaustion), and to what extent workplace knowledge diversity could buffer this relationship. Design/methodology/approach: The authors collected three-wave data of 235 employees from three manufacturing companies in China. They conducted a moderated mediation model to test their hypotheses. Findings: The results showed that work exhaustion mediated the relationship between technostress and employee work well-being and that perceived workplace knowledge diversity buffered this indirect effect. Originality/value: This study might be one of the first attempts using the JD-R theory together with a three-wave longitudinal survey design to empirically examine the mediating role of work exhaustion and the moderating role of workplace knowledge diversity. The authors contribute to the information and technology management literature by underscoring the importance of being aware of technostress and managing technology-induced work exhaustion. They highlight that a knowledge-diverse work environment is an essential context that can help employees to handle difficult and complex tasks presented by various technologies and alleviate experienced technostress. [ABSTRACT FROM AUTHOR]

Glycol ethers have been widely recognized as an alternative biofuels. 2-Methoxyethanol (ME2, HOCH 2 CH 2 OCH 3) is the simplest and most representative glycol ether. Hence, the combustion chemistry of ME2 has aroused extensive interest. The ME2 pyrolysis has been investigated experimentally in a jet-stirred reactor (JSR) at atmospheric pressure within the temperature range of 650–1075 K for the first time. FTIR, GC–MS, and GC-FID were used to identify and quantify species profiles in ME2 pyrolysis. Sixteen intermediates were newly detected by the present work including acetaldehyde, hydroxyacetaldehyde, and methyl vinyl ether which are essential for mechanism development. The H abstraction reactions of ME2 by H, CH 3 , HO 2 , OH, O 2, and the unimolecular reactions of four fuel-related radicals were first studied via high level ab initio calculations. The geometries optimization, vibrational frequencies, and intrinsic reaction coordinate (IRC) calculations were carried out at the M06–2X/6–311++ G (d,p) level of theory. Conventional transition state theory (TST) and Rice-Ramsperger-Kassel-Marcus/Master Equation (RRKM/ME) were used to calculate the temperature- and pressure-dependent rate constants from 300 to 2000 K and 0.01 to 100 atm for the first time. It is found that the H abstraction reactions at the two middle carbon atoms are the most favored pathways, and b-scissions for fuel-related radicals have the lowest energy barriers. The thermochemical properties of ME2 and its derived radicals have been obtained via the combination of composite methods. A mechanism involving 596 species and 3123 reactions was developed for the first time to predict the ME2 pyrolysis characteristics based on experimental and calculated results obtained by the present work. Good agreements were achieved between the measured and simulated results. Rate of production (ROP), as well as sensitivity analysis, were performed to get a deeper insight into the ME2 pyrolysis. It has been revealed that the major ME2 decomposition channels are the H abstractions by H, CH 3 , and OH radicals, and unimolecular reactions have scarce contributions to fuel decay. The results, in terms of the measured data and of the calculated results, and the newly developed kinetic model as well as findings obtained within this study will assist and contribute to a better understanding of combustion characteristics of ME2 and of glycol ethers as well. [ABSTRACT FROM AUTHOR]

Background: SWI/SNF, a well-known ATP-dependent chromatin-remodeling complex, plays an essential role in several biological processes. SNF5, the core subunit of the SWI/SNF remodeling complex, inactivated in 95% of malignant rhabdoid tumors (MRT), highlighting its significance in tumorigenesis. However, the role of SNF5 in bladder cancer (BC) remains unknown. In this study, we aimed to investigate the function and potential clinical applicability of SNF5 in BC. Methods: Data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and Cancer Cell Line Encyclopedia (CCLE) databases were used to evaluate the clinical significance of SNF5 in BC. We performed Gene Set Enrichment Analysis (GSEA) and functional assays to investigate the role of SNF5 in BC. Genomics of Drug Sensitivity in Cancer (GDSC) and drug-susceptibility tests were performed to identify the potential value of SNF5 in the treatment of BC. Results: Low SNF5 expression conferred a poor prognosis and was significantly associated with the N-stage in BC. ROC curves indicated that SNF5 could distinguish BC from the normal tissues. In vitro and in vivo functional assays demonstrated that attenuated SNF5 expression could promote cell proliferation and enhance migration by STAT3 activation. We imputed that low SNF5 expression could confer greater resistance against conventional first-line drugs, including cisplatin and gemcitabine in BC. GDSC and drug-resistance assays suggested that low SNF5 expression renders T24 and 5637 cells high sensitivity to EGFR inhibitor gefitinib, and combination of EZH2 inhibitor GSK126 and cisplatin. Conclusions: To the best of our knowledge, the present study, for the first time, showed that low SNF5 expression could promote cell proliferation and migration by activating STAT3 and confer poor prognosis in BC. Importantly, SNF5 expression may be a promising candidate for identifying BC patients who could benefit from EGFR-targeted chemotherapy or cisplatin in combination with EZH2 inhibitor treatment regimens. [ABSTRACT FROM AUTHOR]

In this article, the fixed-time Nash equilibrium (FTNE) seeking problem of multiple autonomous surface vehicles (ASVs) is considered. As individuals fight for an allocation of specific shared but restricted resources, two novel FTNE seeking algorithms are designed for this topic through an error decomposition method. First, a model-based control algorithm with only one convergence time function in a single-layer structure is designed to achieve Nash equilibrium within a fixed time. Then, a FTNE algorithm with a three-layer structure is presented for multiple ASVs subject to system uncertainties. In particular, this paper proposes a hybrid fixed-time event-triggered approach for reducing controller update frequencies and communication frequencies of two algorithms simultaneously, which is capable of decreasing resource consumption in a constrained resource environment. Furthermore, rigorous sufficient criteria are established for fixed-time convergence through Lyapunov stability analysis, and the upper bound on settling time without the requirement of initial conditions is derived. Finally, simulation examples are given to demonstrate the viability of two algorithms. • This paper solves noncooperative game problem of multiple ASVs. • Two FTNE seeking algorithms are firstly proposed. • An error decomposition approach is firstly presented. • A hybrid fixed-time event-triggered approach is presented. • A three-layer control framework is established. [ABSTRACT FROM AUTHOR]

Considering imperfect experimental conditions, here we give a practical proposal on the decoy-state quantum random number generator with weak coherent sources. In the proposal, three different intensities of light sources are used to estimate the contribution of single-photon pulses. System randomness is characterized and simulated through the minimum entropy. Numerical simulation results show that our new scheme can extract out randomness close to the asymptotic case where the fraction of single-photon pulses are exactly known. Furthermore, a proof-of-principle experimental demonstration is presented, showing excellent agreement between experiment and theory. [ABSTRACT FROM AUTHOR]

The performance of a power battery is greatly affected by temperature. This paper optimized the power battery liquid-cooled system and put forward the way of adding fins to the liquid-cooled plate to improve the cooling efficiency of the thermal management system. In this paper, a liquid-cooled battery system model was established, and the thermal balance performance of the parallel liquid-cooled system was studied through numerical analysis. The results show that the parallel liquid-cooled system with an optimized shunt could maintain the maximum temperature of the battery system below 44.31 °C, and the temperature difference of the battery system could maintain at 3 °C, which could meet the temperature requirements of the power battery system. [ABSTRACT FROM AUTHOR]

For practical quantum key distribution (QKD) in finite-data case, full optimized parameters can greatly improve its key rate. To gain such optimal parameters, traditional search algorithms are performed quite frequently despite the high time and hardware overhead, which may be a severe challenge for real-time QKD systems and large-scale QKD networks. In this paper, instead of searching optimal parameters, we employ random forest to directly predict those parameters. Firstly, we illustrate the feasibility of this method with 3-intensity measurement-device-independent QKD (MDI-QKD). Later, we rebuild a versatile model applicable to MDI and BB84 protocol simultaneously. Both numerical simulations demonstrate our method enjoys a low time and hardware overhead compared with traditional search method and achieves over 99% of the optimal secure key rate as well, which is very promising in future QKD applications. [ABSTRACT FROM AUTHOR]

The effects of phase constituents on the deformation behavior and the correlated mechanical properties at different solution temperatures were investigated in medium Mn high Al lightweight steels with different Al contents (Fe-12Mn-(6,8)-Al-1C). This study indicates that the mechanical properties of medium Mn high Al lightweight steels can be significantly enhanced though changing the content of Al and solution treatment. 6Al steel shows lower yield strength (YS) and tensile elongation (TEL) values than those of 8Al steel at the same temperature due to the unitary austenite phase. When Al is added to 8 wt%, both the precipitation of intergranular and intragranular κ-carbide are promoted and the constituents of multiple phases (austenite + ferrite +κ-carbide) result in ultra-high strengthening. The apparent strain partitioning causes by the different characteristics between different phases leads to the high initial strain hardening. During the deformation process, the sufficient formation of slip bands in austenite grains keeps the high strain hardening exponent and postponed the plastic stability, which also contribute to a pronounced ductility. The existence of multiple phases owing to the addition of Al is the key feature of excellent properties in the investigated lightweight steel. [ABSTRACT FROM AUTHOR]

• Panaxynol (PNN) attenuates hypoxia injury and myocardial ischemia in ischemia/reperfusion injury (IRI) mouse model. • The protective effect of PNN is associated with anti-inflammatory, anti-pyroptosis, and anti-apoptotic mechanisms. • PNN can decrease the activation of HMGB1/TLR4/NLRP3 pathways in IRI mice. Panaxynol (PNN) is a common natural minor component in Umbelliferae plants. Many clinical studies have shown that PNN exhibits nutritional value and anti-inflammatory and other pharmacological activities. However, whether PNN can mediate cardiac ischemia/reperfusion injury (IRI) remains unclear. Here, we aimed to determine the potential effects of PNN on myocardial IRI. Myocardial IRI was stimulated in a mouse IRI model, and neonatal rat ventricle myocytes (NRVMs) were exposed to hypoxia/reoxygenation to construct in an vitro model. Myocardial infarction size, myocardial tissue injury, myocardial apoptotic index, hemodynamic monitoring, pyroptosis-related proteins, cardiac enzyme activities and inflammatory responses were examined to assess myocardial injury. It was found that PNN administration markedly reduced myocardial infarct size and apoptosis, suppressed myocardial damage and cell pyroptosis, attenuated pro-inflammatory cytokines and neutrophil infiltration via NLRP3 inhibitor. More importantly, PNN treatment remarkably decreased the expression of TLR4/NF-κB pathway-associated proteins and NLRP3-related pyroptosis proteins by HMGB1 inhibitor. PNN also enhanced cell viability, reduced cardiac enzyme activities, suppressed apoptosis and attenuated inflammation in the isolated NRVMs. Furthermore, vitro studies indicated that MCC950 (a NLRP3 inhibitor) increased the anti-inflammatory and anti-apoptotic effects of PNN on NRVMs via HMGB1/TLR4 pathway. To sum up, our results demonstrate that PNN exhibits a cardioprotective effect by modulating heart IRI-induced apoptosis and pyroptosis via HMGB1/TLR4/NF-κB pathway, thereby inhibiting NLRP3 inflammasome stimulation. [ABSTRACT FROM AUTHOR]

The methods of capturing and transferring the customer value in a product service system (PSS) are studied to capture the customers' intrinsic value requirements, grasp the importance level of requirement, and transform it into design elements to more reasonably allocate resources and develop products more in line with the customers' needs and more competitive at a minimum cost. First, a hierarchical model of the customer value based on the means-end chain theory is constructed to analyze the customer value from the perspective of customer expectations. In the process of determining the importance priority of value elements, the cloud model is used to process the expert evaluation information, and the competitive correction factor and the Kano factor are used to modify the basic importance of the value elements. The customer value in the PSS is then transferred to the product and service performance domain by constructing the parallel house of quality embedded cloud model (PHOQ-ECM). In other words, the cloud model is used to process the group decision-making values with fuzziness and randomness to complete the correlation calculation of the parallel HOQ. The important priority of the performance characteristics is then obtained. Finally, the abovementioned methods are applied to capture and transfer the customer value of a shearer, and the results are compared with other studies. The results show that the hierarchical model of the customer value can more deeply capture the customer value. The cloud model solves the problem of group decision-making with fuzziness and randomness. The competition correction factor and the Kano factor improve the accuracy of the importance priority of the value elements. PHOQ-ECM achieves the transfer and distribution of the customer value to two different objects of product and service and improves the accuracy of the performance characteristics importance priority. The method feasibility and validity are verified through the abovementioned analysis. Consequently, the method can effectively guide the PSS design. [ABSTRACT FROM AUTHOR]

Highlights • The austenite-based, duplex and triplex structures were developed. • Different types of intra-granular and grain boundaries κ -carbides were observed. • The microstructure-dependent mechanical responses were analyzed. • This work can be used to tailor phase constituents of medium-Mn lightweight steels. Abstract We elucidate three distinguished microstructural features and their contribution to the overall properties and strengthening in a Fe–11Mn–10Al–1.25C alloy treated at various temperatures. At 1000 °C, the nano-scaled ordered κ -carbides in the austenitic matrix contributed to YS (1041 MPa) without scarifying ductility (∼30%). At 900 °C, the significantly refined triplex microstructure with GB κ -carbides caused similar YS but limited ductility (∼8%). At 800 °C, a jump of YS but almost no ductility resulted from the synergic effects of the hard ferrite and lamellar microstructure. The microstructure-dependent mechanical responses were further clarified by analyses of flow curves and fractographs. [ABSTRACT FROM AUTHOR]

Abstract Laser shock peening changes the microstructure of a metal surface and causes the severe plastic deformation. This paper studied the changes in the crystal dislocation density and grain size of the microstructure after laser shock peening. The finite element method was used to calculate the deformation of the LY2 aluminum after the laser shock peening under the different number of impact times. Through a subroutine programming, the microstructure prediction programming was embedded into the finite element model to analyze the dislocation density and grain size of the metal. Based on the simulation of the metal microstructure deformation under different laser impact times, it was found that with the increase of the impact times, the growth rate of the plastic deformation layer and the severe plastic deformation layer decreased. At the same time, the grain size refinement rate gradually declined. When the impact times exceeds four, the depth of the severe plastic deformation layer and the grain size have almost no change. [ABSTRACT FROM AUTHOR]

Abstract The microstructural evolution and precipitation behavior of the warm-rolled (WRed) medium Mn steels with no microalloying addition, single Nb addition and multiple Nb-Mo addition treated at 650 °C for various durations were investigated. Different from the lamellar microstructure of hot rolled medium Mn steels and the equiaxed microstructure of cold rolled medium Mn steels after intercritical annealing, the WRed samples of medium Mn steels exhibited the equiaxed and lamellar mixed microstructure, and the equiaxed microstructure ratio became larger with increasing duration s. The addition of Nb or Nb-Mo can respectively increase yield strength of ~ 50 MPa or ~ 180 MPa in average and ultimate tensile strength of ~ 70 MPa or ~ 100 MPa in average without sacrificing the tensile ductility. The stability of austenite can be improved for the smaller average austenite grain size due to the addition of Nb or Nb-Mo. The addition of Mo to the Nb-bearing medium Mn steel can increase the density of nano-precipitates by reducing the mismatch degree between the matrix and precipitates and inhibit the coarsening rate of precipitates. [ABSTRACT FROM AUTHOR]

The authors elucidate here the structure‐mechanical property relationship in Fe–26Mn–xAl–1C steels with different concentration of Al in conjunction with the quantitative assessment of different strengthening mechanisms. Nano‐sized κ carbides contribute significantly to the increase in yield strength of the steel, being ≈1.78 times of the effect of solution hardening by Al. [ABSTRACT FROM AUTHOR]

A cold-rolled Ti-6Al-4V alloy was subjected to consecutive heat treatments at 1283 K for 1 h and at 823 K for 3 h in order to produce a fully lamellar microstructure. Thereafter, the material was processed by high-pressure torsion (HPT) through various numbers of turns up to a maximum of 30. It is shown that the HPT processing leads to exceptional grain refinement with average grain sizes of ~ 70 and ~ 50 nm after 20 and 30 turns, respectively. Tensile testing was conducted at 873 and 923 K with different initial strain rates using the material processed through 20 turns of HPT and this gave a maximum superplastic elongation of 820% at the relatively low temperature of 923 K when testing with an initial strain rate of 5.0 × 10 −4 s −1 . The associated strain rate sensitivity for this low temperature superplasticity was estimated as m  ≈ 0.5 which is consistent with flow by grain boundary sliding. [ABSTRACT FROM AUTHOR]

The present work aims to reveal the influence of κ-carbides precipitated in grain interior (GI) and along grain boundaries (GBs) with various characteristics on the strain hardening behavior of Fe–11Mn-(7, 10)Al-(0.6, 0.9, 1.2)C steels. Because of the higher probability for moving dislocations meeting with κ-carbides and shearing them, the increase in the volume fraction of shearable nano κ-carbides is more favorable for the improvement of the yield strength (YS) but thus induces the lower strain hardening rate (SHR), especially at low strains. The SHR maintains almost constant values even gradually increases during straining as the enhanced κ-carbide precipitation is beneficial to the planar glide softening and thus promotes the slip bands refinement. EBSD and TEM analysis reveal that both the unshearable coarse and sub-micron κ-carbides formed along GBs and in GI hinder the dislocation movement, and the former results in the significant strain localization in α/κ interfaces, consequently bringing about high SHR but premature failure. It is hoped that these findings will help achieving better synergy of strength and ductility of lightweight steels by utilization of the unshearable sub-micron κ-carbide in addition to the shearable one and partial-recrystallization. [ABSTRACT FROM AUTHOR]

An ultrafine microstructure consisting of α grains (~ 0.51 µm) and a small amount of β phase was successfully achieved in a friction stir-processed (FSPed) Ti-6Al-4V alloy. The fraction of high angle grain boundaries (HAGBs) with random crystallographic orientations reached 89.3% revealed that dynamic recrystallization was responsible for the ultra-grain refinement mechanism during friction stir processing (FSP). Low-temperature superplasticity (LTSP) of such an ultrafine microstructure was demonstrated in the temperature range of 550–650 °C and strain rates of 1 × 10 −4 –3 × 10 −3 s −1 . Specifically, an extremely superior LTSP of 1130% was achieved at 600 °C and 3 × 10 −4 s −1 , which was explained by means of the ultrafine equiaxed grains, a large proportion of HAGBs with random orientations as well as the presence of β phase. The predominant superplastic deformation mechanism was considered as grain boundary sliding associated with grain boundary diffusion. [ABSTRACT FROM AUTHOR]

Regulator of G-protein signalling 5 (RGS5) is, highly expressed in different cell types of the adult human heart, and it is a negative regulator of G protein-mediated signalling that inactivates Gα(q) and Gα(i) and thereby inhibits many signalling pathways. However, the critical role of RGS5 in the pathology of myocardial infarction (MI) remains unexplored. Here, an in vitro MI model, induced by the permanent ligation of the left anterior descending coronary artery, was used with the isolated hearts of wild type (WT) and RGS5-knockout (KO) mice. Our results showed that the loss of RGS5 decreased the post-MI survival rate and left ventricular (LV) function and increased the infarct size. Additionally, the RGS5 knockout mice exhibited greater inflammation, apoptosis, and ventricular remodelling compared with WT-MI mice. Mechanistically, RGS5 loss activated the pathological response mainly by affecting the NF-κB and MAPK signalling pathways. Therefore, our data strongly indicate that RGS5 is a novel modulator of pathological progression after MI that functions NF-κB and MAPK signalling. [ABSTRACT FROM AUTHOR]

General information of China’s coal production, processing, and standardization of coal quality management over the past 30 years is introduced in this article. Analysis of the present situation and future projections of China’s coal production are also presented. Coal production in China increased year by year from 1980 and reached the maximum of 3.974 Gt in 2013. Provinces including Shanxi, Inner Mongolia, and Shaanxi are the main coal producing regions in China at present and Xinjiang will become another important coal producer in the future. The production of low-rank bituminous coal and lignite increased rapidly in the past 10 years. Coal consumption for electricity generation accounts for about 50% of product coal in China, much lower than that in developed countries. On the contrary, the proportion of coal consumption for coke-making is higher than other main coal producing countries, up to about 15% of total coal production. China became a net importer of coal since 2009 and the imports had reached 3.27 Mt in 2013. Coal washing rate in China has remained at a lower level for many years, much lower than that in developed countries (such as America and Europe). As for coal quality management, China has the world’s most systematic management standards for coal quality evaluation and specifications for feed coal in various utilizations. In recent years, with the strengthening of coal management, China has set a series of commercial coal quality standards in which civil coal standards were also included. China is facing the problem of decline in coal demand in recent years. Traditional coal production has suffered from excess capacity and higher inventory in China since 2012. The development of coal industry in China will change to rely more on quality and efficiency, developing scientific capacity, and achieving clean utilization. [ABSTRACT FROM AUTHOR]

This study aims to investigate and test a new image reconstruction algorithm applying to the low-signal projections to generate high quality images by reducing the artifacts and noise in the cone-beam computed tomography (CBCT). For the low-signal and noisy projections, a multiple sampling method is first utilized in projection domain to suppress environmental noise, which guarantees the accuracy of the data for reconstruction, simultaneously. Next, a fuzzy entropy based method with block matching 3D (BM3D) filtering algorithm is employed to improve the image quality to reduce artifacts and noise in image domain. Then, simulation studies on polychromatic spectrum were performed to evaluate the performance of the proposed new algorithm. Study results demonstrated significant improvement in the signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of the images reconstructed using the new algorithm. SNRs and CNRs of the new images were averagely 40% and 20% higher than those of the previous images reconstructed using the traditional algorithms, respectively. As a result, since the new image reconstruction algorithm effectively reduced the artifacts and noise, and produced images with better contour and grayscale distribution, it has the potential to improve image quality using the original CBCT data with the low and missing signals. [ABSTRACT FROM AUTHOR]

Uropathogenic Escherichia coli (UPEC) adhere to cells in the human urinary tract via type 1 pili that undergo phase variation where a 314-bp fimS DNA element flips between Phase-ON and Phase-OFF orientations through two site-specific recombinases, FimB and FimE. Three fim-lux operon transcriptional fusions were created and moved into the clinical UPEC isolate NU149 to determine their temporal regulation in UPEC growing in the urinary tract. Within murine urinary tracts, the UPEC strains demonstrated elevated transcription of fimA and fimB early in the infection, but lower transcription by the fifth day in murine kidneys. In contrast, fimE transcription was much lower than either fimA or fimB early, increased markedly at 24 h after inoculation, and then dropped five days after inoculation. Positioning of fimS was primarily in the Phase-ON position over the time span in UPEC infected bladders, whereas in UPEC infected murine kidneys the Phase-OFF orientation was favored by the fifth day after inoculation. Hemagglutination titers with guinea pig erythrocytes remained constant in UPEC growing in infected murine bladders but fell substantially in UPEC infected kidneys over time. Our results show temporal in vivo regulation of fim gene expression in different environmental niches when UPEC infects the murine urinary tract. [ABSTRACT FROM AUTHOR]

In this paper, a novel approach named double-sided friction stir processing (DFSP) was proposed to prepare 7050-T7451 aluminum alloy plates, and effects of solution treatment (ST) on microstructures and mechanical properties of DFSP were investigated. The solution treatment at 470 °C for 4.5 h was employed. 7050-T7451 and 7050-ST aluminum alloy plates were used for DFSP, and their experimental results were compared. A significant grain refinement to an average 1.5–2.2 µm was attained by DFSP for both 7050-T7451 and 7050-ST plates. The microstructure exhibits a bimodal character which consists of fine grains with the size of 1–6 µm and ultrafine grains with the size of ~1 µm. The precipitated particles in the SZ of T7451-DFSPed and ST-DFSPed plates are MgZn 2 and MgAlCu/Al 7 Cu 2 Fe. Compared with the T7451-DFSPed plate, the ST-DFSP one shows a higher dissolution degree of Mg and Zn elements, and most dispersoid are retained as η′ phase, additionally, the homogenization of the microhardness distribution of the ST-DFSP plate is improved and a higher tensile strength is obtained while good ductility is maintained. [ABSTRACT FROM AUTHOR]

The turbine blade is one of the most important parts in turbine machinery. Casting deformation is an important index to evaluate the quality of the turbine blade. In order to control the deformation of the turbine blade during investment casting, a novel compensation method based on reverse deformation was proposed in this study. Firstly, the process of deformation compensation was discussed. To overcome the disadvantage of the iteration compensation process, a one-step compensation model was developed based on Taylor expansion. Moreover, a smooth deformation function for the compensation model was regressed based on casting simulation results. Finally, two blades were optimized according to the proposed methodology. The deformations before and after compensation were compared. The results indicated that the casting deformation was reduced significantly. Hence, a more accurate blade can be achieved. [ABSTRACT FROM AUTHOR]

Acoustic absorbers based on resonant cavities or porous materials have been extensively investigated for developing acoustic liners but still suffer from narrow working frequency bands or bulky sizes. Here, we present a meta-liner capable of high-efficiency and broadband sound attenuation via the causality-governed minimal thickness, which utilizes the coherent couplings among the resonant structures and porous materials to enhance the absorption efficiency. The meta-liner consists of a series of parallel-coupled neck-embedded Helmholtz resonators (NEHRs) and a micro-perforated panel (MPP) backed with a metal-foam-filled gap. In constructing the meta-liner, the metal foam plays an essential role in achieving the over-damped condition and the suppression of impedance oscillation, which therefore facilitates the realization of the minimum thickness and the consistently-high absorption avoiding absorption dips. Distinct from the design methods employed in previous studies that take deficient consideration of the effect of high-order acoustic waves, this work introduces the acoustic grating diffraction theory to comprehensively modulate the coupling effects of meta-liners' components from fundamental and high-order waves, which enables more precise modulation of meta-liners and leads to improve absorption performance in practice. As a proof-of-concept demonstration, we theoretically designed and experimentally validated a meta-liner supporting unanimously high-efficiency sound absorption from 800 Hz to 3200 Hz with a thickness of only 40 mm. Our work enriches the design concepts of acoustic liners and provides an efficient pathway to construct broadband meta-liners against absorption dips via the causality-governed thinnest structures, which may benefit the applications in noise-control engineering and impedance engineering. [Display omitted] • The meta-liner achieves high-efficiency sound absorption via a thin structure. • Metal foam optimizes intrinsic losses based on the causality-governed condition. • The theoretical model modulates high-order couplings of meta-liners. • The coupling effects among meta-liner's components of dominants in the absorption. [ABSTRACT FROM AUTHOR]

Adsorption is a widely applied technique in producing high‐purity chemicals with advantages of low energy consumption, high selectivity, and mild operating conditions. However, traditional adsorbents have inflexible properties and suffer from the trade‐off between selective adsorption and efficient desorption. Recently, the emerging photoresponsive adsorbents have provided new avenues for adsorption techniques. Active sites of photoresponsive adsorbents can be regulated through steric hindrance or tunable adsorbent‐adsorbate interactions. Therefore, variation in adsorptive capacity is able to readily achieve through photomodulation, and the corresponding adsorption/desorption cycles are energy‐saving. This concept mainly summarizes recent efforts on the fabrication and application of photoresponsive adsorbents with tunable active sites. Also, the future opportunities and critical challenges of photoregulation on adsorptive sites are presented. [ABSTRACT FROM AUTHOR]

• A new set of mechanism-based unified viscoplastic constitutive equation of Al-Zn-Mg-Cu alloy has been proposed. • The new damage evolution equation considered the critical strain of cavity nucleation. • The set of constitutive equations have been coupled into crystal plasticity finite element method(CPFEM). • CPFEM combined innovatively with the unified viscoplastic constitutive equation. A new set of physically-based unified viscoplastic constitutive equations using internal state variable(ISV) method during the superplastic deformation of Al-Zn-Mg-Cu alloy at temperatures ranging from 480 to 530 ℃ and strain rates ranging from 3×10−4s−1 to 3×10−3s−1 has been proposed. The damage evolution equation in this set of constitutive equations takes into account the critical cavity nucleation strain. This set of constitutive equations can predict microstructure evolution and flow stress during superplastic deformation of the investigated Al-Zn-Mg-Cu alloy. The set of constitutive equations have been coupled into crystal plasticity finite element method for determining the evolution of grain size and cavity volume fraction and the lattice rotation field map. The Material parameters are determined by genetic algorithm. The influences of strain, strain rate and temperature on grain size evolution and cavitation behavior were analyzed. The predicted stress-strain behavior, grain size and damage evolution are in good agreements with the experimental results. [ABSTRACT FROM AUTHOR]

Objective: To examine whether the combination of anesthetic preconditioning and anesthetic postconditioning could elicit additional cardio-protection as compared to either anesthetic preconditioning or anesthetic postconditioning alone and its underlying mechanism. Methods: Isolated rat hearts were randomized into one of four groups: CTRL group (30 min of ischemia followed by 120 min of reperfusion alone); SpreC group (3% sevoflurane preconditioning was administered for 15 min followed by 10 min of washout before ischemia); SpostC group (3% sevoflurane postconditioning was administered during the first 15 min of reperfusion after ischemia); SpreC+SpostC group (the protocols of SpreC and SpostC were combined). Hemodynamics, myocardial infarct size, lactate dehydrogenase and creatine kinase-MB in collected effluent, phosphorylation of PKB/Akt and ERK 1/2 and content of nicotinamide adenine dinucleotide in the left ventricular tissue were compared among the four groups. Results: When compared with unprotected Control hearts, those in the sevoflurane-treated groups (SpreC, SpostC and SpreC+SpostC) showed significantly better functional recovery, reduced myocardial infarct size and decreased lactate dehydrogenase and creatine kinase-MB release. Comparison of the above-mentioned variables among the three sevoflurane-treated groups showed that maximal cardio-protection was obtained in the SpreC+SpostC group. Both SpreC and SpreC+SpostC induced a biphasic response in protein kinase B (PKB/Akt) and extracellular signal-regulated kinase (ERK 1/2) phosphorylation, while SpostC induced only one phase. The effects on phosphorylation of both PKB/Akt and ERK 1/2 induced by SpreC and SpostC were found to be additive during reperfusion. The combination of SpreC and SpostC also had additive effects on inhibiting mitochondrial permeability transition pore (mPTP) opening induced by ischemia-reperfusion. Conclusion: These findings suggested that the cardio-protection induced by SpreC and SpostC could be additive via the involvement of PKB/Akt, ERK 1/2 and mPTP. [ABSTRACT FROM AUTHOR]

Three low density Fe–18Mn–10Al– x C steels containing 0.5, 0.8 and 1.2 C (wt%) were utilized to investigate the differences in microstructures and their influence on mechanical behaviors during plastic deformation. The 0.5C steel had a duplex ferritic–austenitic structure and the fraction of austenite was ~59.2%, while the fraction of austenite was ~84.8% for the 0.8C steel and some ordered phases existed in both ferrite and austenite. In contrast, a fully austenitic microstructure with some κ carbides was achieved in the 1.2C steel. Due to the existence of the ordered phases by the addition of C from 0.5% to 0.8%, the 0.8C steel exhibited a highest tensile strength of ~979 MPa, and a moderate strain hardening capacity. The 1.2C steel revealed a superior combination of strength and ductility (ultimate tensile strength of 946.7 MPa and elongation to failure of 56%), with a much more pronounced strain hardening than the other two steels. The differential Crussard–Jaoul (C–J) analysis demonstrated a two-stage strain hardening behavior in both 0.5C and 0.8C steels, while a three-stage one in the 1.2C steel. This difference in strain hardening behavior was further understood in terms of microstructural analysis at the different stages of plastic deformation. [ABSTRACT FROM AUTHOR]

2 mm thick Al-7B04 alloy sheets under T6, T4 and O tempers were subjected to friction stir processing (FSP). The microstructure, Vickers hardness and tensile properties of the stir zone were characterized. The results show that the initial base metal temper has a significant impact on the microstructure and the mechanical properties of the stir zone. FSP led to the formation of full recrystallized microstructure, the average grain size in the stir zone ranged from 2.1 to 2.2 μm when the base metal tempers were T6 and T4. On account of the relatively strong pin force of the precipitates, the grains in the stir zone became finer when O temper base metal was applied. Besides, the stir zones produced using the base metal under T6 and T4 tempers were softened, while a significant strengthening was observed when the base metal temper was O. The softening in the stir zone for T6 and T4 temper is attributed to the dissolution of fine strengthening precipitates during FSP, and the strengthening for O temper arises from the grain refinement caused by FSP. [ABSTRACT FROM AUTHOR]

Samples with one through three passes with 100% overlap were created using friction stir processing (FSP) in order to locally modify the microstructure and mechanical properties of a cold-rolled Al-5083 alloy. A constant traverse speed and two different rotational speeds were used for processing. The results indicated that single-pass FSP caused dynamic recrystallization in the stir zone, leading to equiaxed grains with high angle grain boundaries. The grain size increased with increasing the rotational speed. The product of ultimate tensile strength and total elongation of the stir zone was significantly enhanced compared with that of the base metal. During the annealing heat treatment, abnormal grain growth (AGG) occurred throughout the stir zone when a low rotational speed was adopted. The stir zone produced with a high rotational speed was found to be more resistant to AGG. The application of multiple process passes did not change the grain size and mechanical properties of the stir zone significantly. The expanding of AGG in the stir zone was inhibited as the number of passes was increased. [ABSTRACT FROM AUTHOR]

Summary Background The influenza A(H7N9) virus causes a serious disease that threatens human health. Fatalities associated with human infections caused by this virus are of great public health concern; however, the possible risk factors are not yet fully known. Methods A stratified sampling method, incorporating household income levels and a random number table method, was used to select laboratory-confirmed A(H7N9) cases for this study. Eighty-five patients were selected randomly from 139 laboratory-confirmed A(H7N9) cases occurring in Zhejiang Province between March 1, 2013 and June 30, 2014. Data were collected using a standard method. To test the statistical significance among discrete variables, univariate analyses were used to compare two groups. The Kaplan–Meier product-limit method was used to analyze the patient survival fraction. The Cox proportional hazards regression model was used to analyze all variables with p ≤ 0.05 in the univariate analysis. Lastly, a stepwise procedure was used to construct a final model with a significance level of p > 0.10 for removal and p < 0.05 for re-entry. Results A total of 85 patients with H7N9 virus infection were identified. Among these, 30 (35.29%) died. In the univariate analysis, the following factors were associated with a high risk of influenza A(H7N9) case fatality: age ≥60 years ( p = 0.008), low education level ( p = 0.030), chronic diseases ( p = 0.029), poor hand hygiene ( p = 0.010), time from illness onset to the first medical visit ( p = 0.029) and to intensive care unit admission ( p = 0.008), an incubation period of ≤5 days ( p = 0.039), a peak C-reactive protein ≥120 mg/l ( p = 0.012), increased initial neutrophil count ( p = 0.020), decreased initial lymphocyte count ( p = 0.021), and initial infection of both lungs ( p = 0.003). Multivariate analysis confirmed that the independent predictors of H7N9 virus infection mortality in Zhejiang, China were hand hygiene (hazard ratio (HR) 5.163, 95% confidence interval (CI) 1.164–22.661), age (HR 1.042, 95% CI 1.007–1.076), and peak CRP (HR 1.009, 95% CI 1.002–1.016). Conclusions Improvements in immunity, early case identification and treatment, and personal protection measures are key to addressing the high human avian influenza A(H7N9) case fatality rate. [ABSTRACT FROM AUTHOR]

The present work aims to investigate the effects of grain size on hydrogen embrittlement of a hot rolled Fe-22Mn-0.6C TWIP steel. The as-delivered material was annealed at different annealing cycles and obtained the grain sizes from 4 μm to 45 μm. The susceptibility to hydrogen embrittlement was investigated by carrying out slow strain rate test with hydrogen pre-charged specimens with hydrogen content between 0 and 10 ppm. The results revealed that the investigated steel grade was susceptible to hydrogen embrittlement. Both fracture stress and strain in the hydrogen pre-charged specimens declined in comparison to the uncharged condition. Besides, the materials obtained higher susceptibility to hydrogen embrittlement as the grain size increased. By raising the grain size from 4 μm to 45 μm, the strain loss was raised by more than four times due to the pre-charged hydrogen in 5 ppm level. The raised susceptibility to hydrogen embrittlement can be explained by the early initiation and high density of deformation twins as well as the raised hydrogen content per unit grain boundary area. [ABSTRACT FROM AUTHOR]

During meiosis, homologous chromosomes pair and recombine via repair of programmed DNA double-strand breaks (DSBs). DSBs are formed in the context of chromatin loops, which are anchored to the proteinaceous axial element (AE). The AE later serves as a framework to assemble the synaptonemal complex (SC) that provides a transient but tight connection between homologous chromosomes. Here, we showed that DESYNAPTIC2 (DSY2), a coiled-coil protein, mediates DSB formation and is directly involved in SC assembly in maize (Zea mays). The dsy2 mutant exhibits homologous pairing defects, leading to sterility. Analyses revealed that DSB formation and the number of RADIATION SENSITIVE51 (RAD51) foci are largely reduced, and synapsis is completely abolished in dsy2 meiocytes. Super-resolution structured illumination microscopy showed that DSY2 is located on the AE and forms a distinct alternating pattern with the HORMA-domain protein ASYNAPTIC1 (ASY1). In the dsy2 mutant, localization of ASY1 is affected, and loading of the central element ZIPPER1 (ZYP1) is disrupted. Yeast two-hybrid and bimolecular fluorescence complementation experiments further demonstrated that ZYP1 interacts with DSY2 but does not interact with ASY1. Therefore, DSY2, an AE protein, not only mediates DSB formation but also bridges the AE and central element of SC during meiosis. [ABSTRACT FROM AUTHOR]

In the present study the determining role of niobium (Nb) on significant enhancement in mechanical properties in a low-carbon quenched and partitioned steel is elucidated. The study indicates that solute drag and precipitation pinning effect of Nb suppressed the recrystallization during hot deformation, leading to grain size refinement of hot-rolled steels. The cold-rolled and final microstructure after Q–P treatment was also refined because of refined hot rolled microstructure. Additionally, the degree of refinement was enhanced with increase in Nb-content. The tensile strength of the experimental steels was increased with increase in Nb-content from 1130 MPa in steel without Nb to 1210 MPa in steel with 0.048 wt% Nb. However, the total elongation first increased to 18% followed by a small decrease to 15%. The decrease in ductility is attributed to the consumption of carbon by precipitating NbC, which decreased the enrichment of austenite by carbon during partitioning, with consequent decrease in the stability of austenite. The decrease in the stability of retained austenite ultimately reduced the volume fraction of retained austenite and led to reduction in elongation. [ABSTRACT FROM AUTHOR]

The grain boundary sliding and its accommodation mechanism during superplastic deformation have been identified by surface observations with focused ion beam in an Al–Zn–Mg–Cu alloy. The high-temperature in-situ tensile test is carried out in the scanning electron microscope under the region Ⅱ superplastic conditions. The experiment results indicate that the grain boundary sliding is the dominant superplastic deformation mechanism accommodated by diffusion creep and a little dislocation activity. The grain rotation also plays an essential role in superplastic deformation. There are no striated zones found in a vacuum environment, just cracks. A grain boundary sliding model is proposed based on the surface features. [ABSTRACT FROM AUTHOR]

[Display omitted] • The coating of multilayer graphene helps mitigate the heat dissipation issues in GaN-based transistors. • The ITC of GaN/graphene interface can be modulated by point-defect or h-BN intercalation. • Loading ~1GPa pressure will result in 6-fold enhancement in the ITC of GaN/graphene interface. Gallium nitride (GaN)-based high-electron-mobility transistors (HEMTs) have attracted significant research attention because of their high-power and high-frequency electronics applications such as 5G wireless networks and light-emitting diodes. Meanwhile, the output power density of these HEMTs is particularly high, and strong Joule self-heating hot spots formed at the near-junction seriously restricts device performance and reliability. Hence, heat removal is in urgent demand for GaN-based HEMTs. Multilayer graphene, featuring high thermal conductivity and being easily prepared, is of interest for integration with GaN to improve the device thermal management. In this work, we have investigated the interfacial thermal conductance (ITC) across GaN/graphene interface using nonequilibrium molecular dynamics simulations. The results show that a 0.6% point-defect concentration results in 2.4-fold enhancement in ITC. Moreover, the ITC value can be increased up to 520.7 MWm−2 K−1 by applying ∼ 1GPa cross-plane pressure, which is close to the measurement result for epitaxially grown GaN/ZnO interface. Detailed analyses of vibrational spectra and spectral phonon transmission are performed to help understand the significant enhancement of ITC. Furthermore, the ITC could be also regulated by the external temperature and h-BN intercalation. Our findings presented here provide important guidelines for solving the thermal management issue in GaN-based electronic devices. [ABSTRACT FROM AUTHOR]

• A novel two-stage warm rolling schedule was developed to process the investigated medium Mn steel (Fe-5.9Mn-0.9Al-0.28C). • The two-stage warm rolling and following intercritical annealing introduced a heterogeneous microstructure mixed with lath-typed and granular ferrite and austenite grains into the studied steel. • The annealed sample exhibited ultra-high yield and ultimate strength of 905 MPa and 1320 MPa, respectively, and the products of strength and elongation could reach 60.2 GPa.%. • Except for the transformation induced plasticity effect, the excellent mechanical properties of the two-stage warm rolling sample also rely on the fine-grained strengthening and hetero-deformation induced hardening. A heterostructured medium Mn steel with duplex phases (ferrite and austenite) and multiple morphologies (lath-typed and granular) is fabricated by a novel two-stage warm rolling process and subsequent intercritical annealing. The obtained sample exhibits excellent mechanical properties with the yield strength and ultimate tensile strength of 905 MPa and 1320 MPa, respectively, and the total elongation of 45.6%, the mechanical properties are higher than those of the hot rolled samples and the one-stage warm rolled samples. The microstructural evolution during the two-stage warm rolling process and annealing are characterized and the strain partitioning behavior of the material is investigated. It is indicated that the outstanding mechanical properties and the strain hardening ability rely on the combination of the transformation induced plasticity (TRIP) effect and the hetero-deformation induced (HDI) hardening. [Display omitted] [ABSTRACT FROM AUTHOR]

The high strength and good formability in low-carbon quenching and partitioning (Q−P) steels has been successfully obtained by full or partial austenization before Q−P process. In this regard, we have studied the effect of annealing conditions on the microstructural variation and the consequent strain hardening behaviors in a low-carbon Q−P steel. The microstructures of Q−P steels subjected to different annealing treatments were studied in details by a host of material characterization techniques including electron microscopy, electron microprobe and x-ray diffraction techniques. The study suggests that intercritical annealing is beneficial in increasing the volume fraction of retained austenite, which is the consequence of distribution of alloying elements during intercritical annealing and it enhances the stability of intercritically annealed austenite. Meanwhile, compared with the full austenitizing Q−P steel, the strain hardening of partial austenitizing Q−P steel is enhanced by the presence of intercritical ferrite and increasing volume fraction of retained austenite. [ABSTRACT FROM AUTHOR]

The double heterogeneities of microstructure and composition are introduced in a medium Mn steel via the partially austenite reversed transformation (PART). The role of these heterogeneities in the mechanical properties is revealed. A heterogeneous microstructure consisting of both the granular and lath-typed ferrite/austenite grains is obtained in the PART sample. During plastic deformation, the lath-typed microstructures bear more deformation than the granular ones due to their unique morphological geometry, leading to strain partitioning. This mechanical incompatibility gives rise to significant hetero-deformation induced (HDI) hardening and thus a remarkable enhancement of the mechanical properties. The compositional heterogeneity, i.e. Mn concentration in the lath-typed austenite is higher than that in the granular austenite, is also obtained in the PART steel. Such heterogeneity gives rise to different austenite stabilities and thus sustainable martensitic transformation at different stages of deformation, which also contributes to the enhancement of the mechanical properties. These results provide new insights into the design of advanced metallic materials with outstanding mechanical properties via the double heterogeneity of microstructure and composition. [ABSTRACT FROM AUTHOR]

This paper aimed to study the effects of annealing temperature on the microstructures and yield strength (YS) in the Fe-11Mn-xAl-yC medium-Mn lightweight steels, and reveal the structure-strength relationships and strengthening mechanisms. As the annealing temperature decreased from 1100 °C to 850 °C, the YS of the IG κ-carbide-free Fe-11Mn-7Al-0.6C steel (0.6C) could be improved from 482 MPa to 630 MPa by grain size refinement strengthening. When the 0.6C steel was annealed below 800 °C, partial recrystallization occurred and brought about a great increase in the YS up to 1.1 GPa by the high dislocation density (8.2–10.9 × 1014 m−2). The increases in the contents of C and Al promoted the precipitation of both grain boundary (GB) and intra-granular (IG) κ-carbides. Thus, the 1000 °C-annealed Fe-11Mn-10Al-1.2C steel possessed an austenite matrix containing nano κ-carbide and a small amount of α-ferrite, and achieved ultrahigh YS of 1242 MPa by relying on the remarkable precipitation strengthening effect (679 MPa). This study provided a new insight into comprehensively understanding the relationships among alloy composition, thermomechanical process (TMP), microstructures and various strengthening mechanisms in the lightweight steels so as to improve the YS. [ABSTRACT FROM AUTHOR]

Correction to: Cancer Cell International (2021) 21:655 https://doi.org/10.1186/s12935-021-023... In this article [[1]], the author would like to update the Funding section as below and the description in Fig. Reference 1 Ding H, Huang Y, Shi J, Wang L, Liu S, Zhao B, Liu Y, Yang J, Chen Z. Attenuated expression of SNF5 facilitates progression of bladder cancer via STAT3 activation. [Extracted from the article]

Direct experimental evidence confirms the partitioning of C to austenite during intercritical annealing is the intrinsic factor that affects the stability of the retained austenite for a newly developed high strength transformation-induced plasticity (TRIP) steel. The volume fraction of retained austenite and C concentration decreases with increasing intercritical annealing time. Few retained austenite grains and a number of M/A islands were observed in the sample at 830°C annealed for 30 min. When the sample annealed at 830°C for 0.5 min and then isothermally treated at 440°C for 3 min, the investigated low alloy TRIP steel achieved the tensile strength higher than 1000 MPa, the total elongation of 21.8% and the n-value of 0.32. [ABSTRACT FROM AUTHOR]

Abstract: A superplasticity mechanism based constitutive equation incorporating deformation-induced grain growth and deformation-accelerated grain boundary diffusion was established. The constitutive equation established was applied to the superplastic two-phase hypereutectic Mg–8.42Li alloy. The contribution of net static grain growth to entire grain growth accounts for 51.65% while the contribution of net strain grain growth to entire grain growth accounts for 48.35%. It is shown by calculation that the grain boundary diffusion in the superplastic deformation of fine grained microduplex Mg–8.42Li alloy at low strain rates is not accelerated obviously and deformation-accelerated grain boundary diffusion takes place at high strain rates. It is indicated by normalizing the data of calculation and experiment that the flow mechanism of this alloy at 573K at an initial strain rate of 5×10−4 s−1 is modified Mukherjee's grain boundary sliding controlled by the motion of the dislocations in the grain boundaries by a climb-glide process and Gifkins's grain boundary sliding occurring by the motion of grain-boundary dislocations that pile up at triple point. [Copyright &y& Elsevier]

Highlights: [•] Hydrogen can be retained in Ti–6Al–4V alloy at temperatures up to 1100°C. [•] Hydrogen induces increased flow stress and work hardening rate of Ti–6Al–4V alloy. [•] Hydrogen has a positive effect on the development of twining in Ti–6Al–4V alloy. [•] Hydrogen-induced twinning plays a key role in the enhancement of work hardening. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the strain hardening behaviors of a low carbon Nb-microalloyed Si–Mn quenching–partitioning (Q–P) steel were investigated. The microstructures were analyzed by the scanning electron microscope (SEM) and transmission electron microscope (TEM). Mechanical tests were used to evaluate the room temperature tensile properties of the steel. The work hardening behaviors of the tested specimens were analyzed using the Hollomon approach. The results showed that a two-stage work hardening behavior was observed during deformation processes. In the first stage, for the quenched samples, martensite deforms plastically and the hardening exponent decreased. For the air-cooled samples, however, the carbide-free ferrite deforms preferentially, and then, the carbide-free ferrite and martensite co-deform. In the second stage, due to the effect of transformation induced plasticity of retained austenite, the hardening exponent decreased slowly and plateaus were observed in the plots of n i –ε t until fracture. Variations of the work hardening behaviors were related to the martensite and the volume fraction of retained austenite in Q–P steels and the microstructural evolution during partitioning and following cooling process. [Copyright &y& Elsevier]