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The influence of electropulsing on the creep behaviour, strength, and microstructure of an Al−Cu−Li alloy during creep ageing was investigated. Electropulsing assisted creep ageing (ECA) and conventional creep ageing (CCA) were carried out under various stress levels and time conditions. Applying electropulsing results in a noteworthy change of creep behaviour, including a variation in creep curves, an increased creep rate in early stage, and an improved creep strain. The ECA specimen experiences a shorter time to the peak strength, and an increase in elongation by ~17.4% without loss of the peak-aged strength compared with CCA specimen. The ultrafine nano-size subgrains are observed to form under electropulsing, which can result in an increased creep strain by increasing grain-boundary sliding. The enhancement of both dislocation interactions and solute diffusion under electropulsing is considered as a primary cause of disappearance of a platform stage during early creep ageing. Some of T1 precipitates around the grain boundary are observed in the peak ECA sample, resulting in an occurrence of transgranular fracture, which is further responsible for an increased elongation of the ECA specimen.

A unified constitutive model is presented to predict the recently observed “multi-stage” creep behavior of Al-Li-S4 alloy. The corresponding microstructural variables related to the yield strength and creep deformation of the alloy during the creep ageing process, including dislocations and multiple precipitates, have been characterized in detail by X-ray diffraction (XRD) and transmission electron microscopy (TEM). For the yield strength, the model considers the multiphase strengthening behavior of the alloy based on strengthening mechanisms, which includes shearable T1 precipitate strengthening, non-shearable T1 precipitate strengthening and θ′ precipitate strengthening. Based on creep deformation mechanism, the “multi-stage” creep behavior of the alloy is predicted by introducing the effects of interacting microstructural variables, including the radius of multiple precipitates, dislocation density and solute concentration, into the creep stress-strain model. It is concluded that the results calculated by the model are in a good agreement with the experimental data, which validates the proposed model.

Due to the integration of information and internet, the power network has facing more and more uncertain risks of malicious attacks. In response to this problem, we studied it from following four aspects. First of all, multiple cyber-attacks (Denial-of-service, information disclosure, replay attack and deception attack) are analyzed from each operating mechanism. Then, the subsystems are concluded to be a generic modeling frame with considering different type cyber-attack. Secondly, secure defense scenarios are proposed according to each kind cyber-attacks based on the mechanism details. Thirdly, security control conditions are derived by utilizing control theory of stability. Finally, IEEE-14 and IEEE-39 system are used as typical cases to illustrate and analyze the impact of dynamic load altering attack on some of these nodes.

The 1,3-dipolar cycloaddition reaction of dimethyl hex-2-en-4-ynedioate with azomethine ylides derived from reaction of l -proline with various isatins in methanol selectively resulted in the formation of functionalized spiro[indoline-3,3′-pyrrolizine]acrylates as main products and spiro[indoline-3,3′-pyrrolizine]propiolates as minor products. This result indicated that the electron-deficient alkyne has higher reactivity than that of electron-deficient alkene in 1,3-dipolar cycloaddition reaction.

Oculopharyngodistal myopathy (OPDM) is an adult-onset inherited neuromuscular disorder characterized by progressive ptosis, external ophthalmoplegia, and weakness of the masseter, facial, pharyngeal, and distal limb muscles. The myopathological features are presence of rimmed vacuoles (RVs) in the muscle fibers and myopathic changes of differing severity. Inheritance is variable, with either putative autosomal-dominant or autosomal-recessive pattern. Here, using a comprehensive strategy combining whole-genome sequencing (WGS), long-read whole-genome sequencing (LRS), linkage analysis, repeat-primed polymerase chain reaction (RP-PCR), and fluorescence amplicon length analysis polymerase chain reaction (AL-PCR), we identified an abnormal GGC repeat expansion in the 5′ UTR of GIPC1 in one out of four families and three sporadic case subjects from a Chinese OPDM cohort. Expanded GGC repeats were further confirmed as the cause of OPDM in an additional 2 out of 4 families and 6 out of 13 sporadic Chinese individuals with OPDM, as well as 7 out of 194 unrelated Japanese individuals with OPDM. Methylation, qRT-PCR, and western blot analysis indicated that GIPC1 mRNA levels were increased while protein levels were unaltered in OPDM-affected individuals. RNA sequencing indicated p53 signaling, vascular smooth muscle contraction, ubiquitin-mediated proteolysis, and ribosome pathways were involved in the pathogenic mechanisms of OPDM-affected individuals with GGC repeat expansion in GIPC1. This study provides further evidence that OPDM is associated with GGC repeat expansions in distinct genes and highly suggests that expanded GGC repeat units are essential in the pathogenesis of OPDM, regardless of the genes in which the expanded repeats are located.

Cell voltage reversal resulting from hydrogen starvation at anode is one of the factors that exacerbate the overall degradation of polymer electrolyte fuel cells (PEFCs). An effective material-based mitigation strategy against cell reversal is to add oxygen evolution reaction (OER) catalysts into the anode to make reversal-tolerant-anodes (RTAs). However, RTAs still suffer from an eventual sudden death, and the failure mechanisms of this sudden death have not been well studied thus far. Here we show a novel in-situ measurement technique with a distinctive partition membrane electrode assembly (MEA) to research the failure mechanism of RTAs. It is observed for the first time that the failure of RTAs is mainly attributed to the destruction of electron conducting paths caused by carbon corrosion from catalyst layers (CLs), gas diffusion layers (GDLs) and bipolar plates (BPs), rather than deactivation of the OER catalyst. As a verification, the application of additional OER catalysts on the GDL is found to effectively prolong the reversal tolerant time. These results add significant new insights into the failure mechanism of the RTA MEA and will be of practical importance in directing to design advanced MEAs and BPs that can withstand cell voltage reversal.

Organoarsenical antibiotics pose a severe threat to the environment and human health. In aquatic environment, dissolved organic matter (DOM)-mediated photochemical transformation is one of the main processes in the fate of organoarsenics. Dicarbonyl is a typical redox-active moiety in DOM. However, the knowledge on the photoconversion of organoarsenics by DOM, especially the contributions of dicarbonyl moieties is still limited. Here, we systematically investigated the photochemical transformation of three organoarsenics with the simplest β-diketone, acetylacetone (AcAc), as a model dicarbonyl moiety of DOM. The presence of AcAc significantly enhanced the photochemical conversion of roxarsone (ROX), whereas only minor effects were observed for 3-amino-4-hydroxyphenylarsonic acid (HAPA) and arsanilic acid (ASA), because the latter two (with an amino (-NH