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Arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) are generally colonized in plant roots in metal-polluted environment. A pot experiment including four treatments (AMF inoculation of Funneliformis mosseae, DSE inoculation of Exophiala pisciphila, co-inoculation of AMF + DSE, and non-inoculation) under a high cadmium (Cd) stress (50 mg/kg) was conducted to discuss the ecological functions and interactions of AMF and DSE. The biomass, photosynthetic physiology, root morphology and traits, Cd content of maize were investigated. According to the two-way analysis of variance, AMF and DSE had no synergetic interactions on the maize performance under the high Cd stress. Both AMF inoculation and AMF + DSE co-inoculation, but not DSE inoculation, significantly increased the chlorophyll contents in maize leaves, resulting in stronger photosynthetic physiology, higher biomass, and increased length, surface area, volume, branches, tips number, and mass density (RTD) of maize roots, but decreased specific root length (SRL), specific root area (SRA), specific root branches (SRB), and specific root tips (SRT). However, there was a strong interaction between AMF and DSE on the Cd content in the maize shoots and roots. Single or co-inoculation of AMF and DSE significantly decreased the Cd content in shoots and Cd transfer coefficient of maize. Correlation analysis indicated that the Cd content in shoots was significantly positively correlated with SRL, SRA, SRB and SRT but negatively correlated with RTD. Thus AMF and DSE altered the root traits that contributed to restricting Cd migration from roots to shoots of maize.

Background Oxidative stress and neuronal apoptosis play important roles in the pathogenesis of early brain injury (EBI) after subarachnoid hemorrhage (SAH). The activation of TGR5, a novel membrane-bound bile acid receptor, possesses anti-oxidative stress and anti-apoptotic effects in hepatobiliary disease and kidney disease. The present study aimed to explore the neuroprotective effect of TGR5 activation against EBI after SAH and the potential underlying mechanisms. Methods The endovascular perforation model of SAH was performed on 199 Sprague Dawley rats to investigate the beneficial effects of TGR5 activation after SAH. INT-777, a specific synthetic TGR5 agonist, was administered intranasally at 1 h after SAH induction. TGR5 CRISPR and ALDH2 CRISPR were administered intracerebroventricularly at 48 h before SAH to illuminate potential mechanisms. The SAH grade, short-term and long-term neurobehavioral tests, TUNEL staining, Fluoro-Jade C staining, Nissl staining, immunofluorescence staining, and western blots were performed at 24 h after SAH. Results The expressions of endogenous TGR5 and ALDH2 gradually increased and peaked at 24 h after SAH. TGR5 was expressed primarily in neurons, as well as in astrocytes and microglia. The activation of TGR5 with INT-777 significantly improved the short-term and long-term neurological deficits, accompanied by reduced the oxidative stress and neuronal apoptosis at 24 h after SAH. Moreover, INT-777 treatment significantly increased the expressions of TGR5, cAMP, phosphorylated PKCe, ALDH2, HO-1, and Bcl-2, while downregulated the expressions of 4-HNE, Bax, and Cleaved Caspase-3. TGR5 CRISPR and ALDH2 CRISPR abolished the neuroprotective effects of TGR5 activation after SAH. Conclusions In summary, the activation of TGR5 with INT-777 attenuated oxidative stress and neuronal apoptosis via the cAMP/PKCe/ALDH2 signaling pathway after SAH in rats. Furthermore, TGR5 may serve as a novel therapeutic target to ameliorate EBI after SAH.

The influence of the inlet and outlet flow parameters on the dynamic performance for the supersonic jet element have been investigated numerically in details. And the precision and errors accumulation of the numerical method has also been estimated. The influence of the main jet pressure and the mass flow rate of the control flow on the output thrust as well as the switching time have been deeply studied. The results have shown that increasing the mass flow rate of the control flow can shorten the switching time and increase the effective thrust slightly, but it also can enhance the unsteadiness of flow in the wall-attached work state but decrease the energy utilization rate of the supersonic jet flow component. The effective thrust generated by the cold air is larger than the gas work medium. And the switching time for the gas working medium is also shorter, which is more conducive to the completion of the switch process. The vortical structures at different switching time together with the force variations inside the jet element have been obtained computationally and analyzed in details.

Based on the unsteady viscous flow simulation, the flow characteristics inside the supersonic jet Element have been investigated numerically. The results have revealed that once the specific structures of the supersonic jet element are finalized, even if the boundary conditions remain unchanged, the corresponding internal flow will also shows strong unsteady in a certain range of primary gas source pressure. The instability of the main vortex center is a main reason to make the output thrust of the supersonic jet components fluctuate all the time in the attached wall condition. At the deflection of the jet stage, once the static pressure for the right side of the wedge exceeds the left side, the transverse expansion for the stripping zone near the right output channel entrance can play a significant role in making the primary jet deflect successfully. When the jet starts to attach the wall layer, due to the “Coanda” effect, the jet also can attach the layer successfully even though the corresponding control flow is totally closed. When the jet enters the adjustment stage, the thrust changes process for the left and right outputs will experience two typical stages: adjusting and adjusted stages. The corresponding vortex structures at different switching time together with the force variations etc. inside the jet Element have been obtained computationally and analyzed in details.

To improve the performance/cost ratio of NdFeB based permanent magnets, Ce or/and La substitutions for Nd have been suggested. To better understand the effects of these substitutions, the fundamental behavior of (Ce,La)-Fe-B alloys has to be clearly understood. Here, we reported a systematic investigation on the phase structure, microstructure, and magnetic properties of melt-spun (Ce,La)2Fe14B alloys. The results confirm that partial substitution of Ce by La can effectively enhance the hard magnetism and thermal stability of (Ce1-xLax)2Fe14B alloys, while over 80% La substitution leads to the decomposition of 2:14:1 phase. The lattice parameters a, c and the Curie temperature Tc of 2:14:1 phase increase linearly with the increasing La content. La substitution can effectively refine the grain, resulting in the enhancement of inter-grain exchange coupling. The (Ce0.7La0.3)2Fe14B alloy with a mean grain size of 25 nm exhibits high remanence, maximum energy product and intrinsic coercivity up to 0.69 T, 6.2 MGOe and 217 kA/m, respectively. The present work provides a good understanding on the melt-spun (Ce,La)-Fe-B system for further developing low cost rare earth permanent magnets.

Hydrogen treatment technology is developed to recycle the waste Nd-Fe-B sintered magnets in the way of short route, low cost, and high efficiency. In present study, effect of hydrogen pressure on hydrogen decrepitation (HD) process of sintered Nd-Fe-B strip casting flakes (SC) and waste sintered magnets (SM) was systematically studied. Both SC and SM show the approximate HD process, which accelerates with increasing pressure. The surface activation process accelerates with increasing pressure, and almost disappears when the initial hydrogen pressure reaches to 6 MPa. The hydrogen content of SM is lower than SC, and increases with increasing pressure. For the SM, blasting power of HD process decreases with the increase of the initial hydrogen pressure. It provides beneficial reference for recycling waste Nd-Fe-B sintered magnets.

Background Subarachnoid hemorrhage (SAH) is a life-threatening subtype of stroke with high mortality and disabilities. Retinoid X receptor (RXR) has been shown to be neuroprotective against ischemia/reperfusion injury. This study aimed to investigate the effects of the selective RXR agonist bexarotene on neuroinflammation in a rat model of SAH. Methods Two hundred male Sprague-Dawley rats were used. The endovascular perforation induced SAH. Bexarotene was administered intraperitoneally at 1 h after SAH induction. To investigate the underlying mechanism, the selective RXR antagonist UVI3003 and RXR siRNA or SIRT6 inhibitor OSS128167 was administered via intracerebroventricular 1 h before SAH induction. Post-SAH assessments including SAH grade, neurological score, brain water content, Western blot, and immunofluorescence were performed. Results The endogenous RXR and sirtuin 6 (SIRT6) protein levels were increased after SAH. Bexarotene treatment significantly reduced brain edema and improved the short-/long-term neurological deficit after SAH. Mechanistically, bexarotene increased the levels of PPARγ and SIRT6; decreased the expression of phosphorylated FoxO3a (p-FoxO3a), IL-6, IL-1β, and TNF-a; and inhibited the microglia activation and neutrophils infiltration at 24 h after SAH. Either UVI3003, OSS128167, or RXR siRNA abolished the neuroprotective effects of bexarotene and its regulation on protein levels of PPARγ/SIRT6/p-FoxO3a after SAH. Conclusions The activation of RXR by bexarotene attenuated neuroinflammation and improved neurological deficits after SAH. The anti-neuroinflammatory effect was at least partially through regulating PPARγ/SIRT6/FoxO3a pathway. Bexarotene may be a promising therapeutic strategy in the management of SAH patients. Electronic supplementary material The online version of this article (10.1186/s12974-019-1432-5) contains supplementary material, which is available to authorized users.

The authors regret that one of the affiliations (affiliation f) was incorrectly omitted in the original manuscript. The corrected list of affiliations is as shown below. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.

A novel Al-based composite reinforced with Ti-based metallic glass (MG) nanoparticles was fabricated by powder metallurgy through mechanical alloying combined with hot extrusion. During the ball-milling process, MG microparticles were refined into nanosized particles through severe plastic deformation. Hot extrusion of the milled powders resulted in a dense and uniform dispersion of the metallic glass nanoparticles in the Al-7075 matrix. This unique homogeneous structure led to a significant enhancement of strength without adversely affecting the plasticity, thus developing super-high specific yield strength. The yield strength increased from 297 MPa for Al-7075 matrix to 530, 610, 880, and 1014 MPa for the composites milled for 10, 15, 30, and 50 h, respectively. A critical analysis of the different factors contributing to the strength of the composites was carried out. Grain refinement, Orowan strengthening, and dislocation–dislocation interactions were demonstrated to be the most important contributors to the enhanced strength of the nanocomposite.

The evolution of argillaceous rock suffering from desaturation/resaturation is a key factor that affects the safety of deep geological repositories of radioactive waste. However, the behavior of this rock when resaturated to nearly 100% relative humidity (RH) has been poorly studied, because water condensation was frequently encountered in the conventional RH-control technique. This issue has been overcome in the present work using an environmental scanning electron microscope (ESEM) that provides improved RH control. The recorded micrographs subsequently were analyzed for full-field strain measurement using digital-image correlation techniques. The results reveal that the swelling (the sample in the size of several millimeters) attained stability in less than an hour during the 30%–80% RH step; however, the swelling strain continued to rise for up to 10h during the 80%–99% RH step. The anomalous time-dependent swelling at nearly 100% RH is not explicable in terms of hydraulic flow or propagation of swelling-induced microcracks. The evolution of strain fields shows that the areas of continuous swelling are located mainly inside the clay matrix. We suggest that the creep-like swelling of clay might be related to an osmotic flow (driven by a solute-concentration gradient) that dissipates more slowly than the hydraulic flow (driven by pressure gradient). The existence of time-dependent swelling in argillaceous rock under resaturated conditions should be considered for the reliability assessment of long-term radioactive waste disposal.

Based on the unsteady viscous flow simulation, the flow characteristics inside the supersonic jet element have been investigated numerically. The corresponding initial switching process has been overall divided into two major stages. The results have shown that the switching process for the supersonic jet flow is an extremely complex process, which can include the complex shock system evolution, the free shear layers together with the boundary layers evolution and multiple vortex region unsteady evolution etc. The presence of the switching oblique shock near the control port is not the necessary condition to make the jet deflect, but its formation is good for the early transverse extension of the stripping vortex zone. A new concept named minimum control mass flow rate has also been proposed and emphasized. The Viscosity and adverse pressure gradient have been found to be the key factors for the occurrence of flow separation to shorten the switching time. The vortex structures at different switching time together with the variations (thrust, static pressure as well as oblique shock waves etc.) inside the supersonic jet element have been obtained computationally and analyzed in details.

The vortex formation and shedding process behind an isolated cylinder under the wake interference of an oscillating airfoil at different oscillating frequencies and amplitudes have been studied numerically. The “2S” and “P+S” mode are found in the drag-producing von Karman vortex wake and thrust-producing inverted von Karman vortex wake, respectively. For the “2P” case, the pairs of vortices with different sizes are laterally parallel to each other. For the “2P+2S” case, the merged single vortices do not appear between the vortex pairs, but they only emerge after every two pairs of vortices. For the two-degree of freedom (2-DOF) VIV in the wake of the steady flow, seven types of the phase portraits of the displacement shapes are observed. In the range of small reduced velocity ( V r 5 ), the body trajectories are mainly characterized by an “8-shape” with some differences in phase. At the peak amplitude, the body trajectories have changed into two shapes: i.e., the half “8-shape” (initial stage) and the crescent-shape (final stage). When V r = 6 , the body trajectories have also shown to have two shapes: i.e., the “8-shape” (initial stage) and the half “8-shape” (final stage). When V r arrives at the low branch ( V r > 7 ), the body trajectories will become irregularly shaped like a cone-net.

The vortex-induced vibration behind an isolated cylinder under the wake interference of an oscillating airfoil at different oscillating frequencies and amplitudes have been studied numerically. Our previous research [11] mainly focused on the two degree of freedom vibration problem, several types of the phase portraits of the displacement have been newly found, including the "half -8″ and "cone-net" types as reduced velocity increases. At present, we have continued the research to the single degree of freedom vibration, the corresponding results had been found that under the wake of the free steady flow, as the reduced velocity increases, the phase portraits displacements of the single degree of freedom vibrating cylinder will begin to rotate counterclockwise from the first and third quadrants to the second and fourth quadrants in a Cartesian coordinate system. Under the wake of the oscillating airfoil, the single bending curve and the single closed orbit (double “8-shape” like) of the displacements are newly found in the drag and thrust producing cases respectively. Except this, the two triplets of vortices have also been newly found in the pair and single plus pair wakes at each cycle. The vorticity dynamics behind the vibrating cylinder together with the corresponding force variations have also been obtained computationally and analyzed in details. Accepted version

The Mn1-xCrxCoGe (x = 0.01, 0.015, 0.02, 0.03) alloy ribbons are prepared. The microstructure, structure, magnetic and magnetocaloric properties were studied in these ribbons. The substitution of Cr for Mn effectively reduces the structural transformation temperature of MnCoGe alloy. In annealed Mn0.98Cr0.02CoGe ribbons, a coupled magnetostructural transformation from the ferromagnetic TiNiSi-type to paramagnetic Ni2In-type state with the increasing temperature is observed. As a result, large magnetocaloric effect near room temperature and simultaneously almost zero magnetic hysteresis losses presented in these ribbons would be favorable to room-temperature magnetic refrigeration. In measuring the isothermal magnetization curves, both the loop and standard methods are adopted to compare and make sure the reliability of our results.

BackgroundCardiac arrest survivors suffer from neurological dysfunction including cognitive impairment. Cerebral mast cells, the key regulators of neuroinflammation contribute to neuroinflammation-associated cognitive dysfunction. Mast cell tryptase was demonstrated to have a proinflammatory effect on microglia via the activation of microglial protease-activated receptor-2 (PAR-2). This study investigated the potential anti-neuroinflammatory effect of mast cell tryptase inhibition and the underlying mechanism of PAR-2/p-p38/NFκB signaling following asphyxia-induced cardiac arrest in rats.MethodsAdult male Sprague-Dawley rats resuscitated from 10 min of asphyxia-induced cardiac arrest were randomized to four separate experiments including time-course, short-term outcomes, long-term outcomes and mechanism studies. The effect of mast cell tryptase inhibition on asphyxial cardiac arrest outcomes was examined after intranasal administration of selective mast cell tryptase inhibitor (APC366; 50 μg/rat or 150 μg/rat). AC55541 (selective PAR-2 activator; 30 μg/rat) and SB203580 (selective p38 inhibitor; 300 μg/rat) were used for intervention. Short-term neurocognitive functions were evaluated using the neurological deficit score, number of seizures, adhesive tape removal test, and T-maze test, while long-term cognitive functions were evaluated using the Morris water maze test. Hippocampal neuronal degeneration was evaluated by Fluoro-Jade C staining.ResultsMast cell tryptase and PAR-2 were dramatically increased in the brain following asphyxia-induced cardiac arrest. The inhibition of mast cell tryptase by APC366 improved both short- and long-term neurological outcomes in resuscitated rats. Such behavioral benefits were associated with reduced expressions of PAR-2, p-p38, NFκB, TNF-α, and IL-6 in the brain as well as less hippocampal neuronal degeneration. The anti-neuroinflammatory effect of APC366 was abolished by AC55541, which when used alone, indeed further exacerbated neuroinflammation, hippocampal neuronal degeneration, and neurologic deficits following cardiac arrest. The deleterious effects aggregated by AC55541 were minimized by p38 inhibitor.ConclusionsThe inhibition of mast cell tryptase attenuated neuroinflammation, led to less hippocampal neuronal death and improved neurological deficits following cardiac arrest. This effect was at least partly mediated via inhibiting the PAR-2/p-p38/NFκB signaling pathway. Thus, mast cell tryptase might be a novel therapeutic target in the management of neurological impairment following cardiac arrest.

Room temperature magnetic properties and coercivity mechanisms for nanocomposites [(La 0.5 Ce 0.5 ) 1− x RE x ] 10 Fe 84 B 6 (RE=Nd or Dy; x =0, 0.3, 0.5, and 0.7) alloys prepared by melt-spinning have been investigated. Nd and Dy substitutions can improve the hard magnetic properties, especially the coercivity of [(La 0.5 Ce 0.5 )] 10 Fe 84 B 6 alloy. The largest values of intrinsic coercivity H c and maximum energy product (BH) max for the Dy substituted alloys are 714 kA/m and 41 kJ/m 3 , respectively, whereas for Nd substituted alloys, H c =365 kA/m and (BH) max =120 kJ/m 3 were obtained for x =0.7. The different elevated temperature behaviors were also found for Nd and Dy added alloys. The composition dependent coercivity mechanisms for Dy and Nd substituted alloys are evident based on the temperature dependence of coercivity described by domain wall pinning and reverse domain nucleation models. It is found that the domain wall pinning mechanism is possibly responsible for [(LaCe)Nd]FeB alloys while reverse domain nucleation is more likely responsible for[(LaCe)Dy]FeB alloys.

The poor hot workability of aluminum matrix composites (AMCs) severely limits their engineering use. Here an abnormal hot deformability phenomenon was observed in a metallic glass-particle-reinforced AMC in which the composite shows higher strength at room temperature and lower strength at higher temperatures than the monolithic Al-7075 alloy, indicating excellent hot workability. It reveals that the metallic glass at high temperature may be as a soft binder to release the local stress concentration during deformation owing to drop in viscosity. This study provides new opportunities for designing and achieving good workability in AMCs for advanced structural applications.

Oxidative stress and neuronal apoptosis have been demonstrated to be key features in early brain injury (EBI) after subarachnoid hemorrhage (SAH). Previous studies have indicated that Mas receptor activation initiates an anti-oxidative and anti-apoptotic role in the brain. However, whether Mas activation can attenuate oxidative stress and neuronal apoptosis after SAH remains unknown. To investigate the beneficial effect of Mas on oxidative stress injury and neuronal apoptosis induced by SAH, a total of 196 rats were subjected to an endovascular perforation model of SAH. AVE 0991 (AVE), a selective agonist of Mas, was administered intranasally 1 h after SAH induction. A779, a selective inhibitor of Mas, and small interfering ribonucleic acid (siRNA) for UCP-2 were administered by intracerebroventricular (i.c.v) injection at 1 h and 48 h before SAH induction respectively. Neurological tests, immunofluorescence, TUNEL, Fluoro-Jade C, DHE staining, and Western blot experiments were performed. We found that Mas activation with AVE significantly improved neurobehavioral scores and reduced oxidative stress and neuronal apoptosis in SAH+AVE group compared with SAH+vehicle group. Moreover, AVE treatment significantly promoted phosphorylation of CREB and the expression UCP-2, as well as upregulated expression of Bcl-2 and downregulation of Romo-1 and Bax. The protective effects of AVE were reversed by i.c.v injection of A779 and UCP-2 siRNA in SAH+AVE+A779 and SAH+AVE+UCP-2 siRNA groups, respectively. In conclusion, our data provides evidence that Mas activation with AVE reduces oxidative stress injury and neuronal apoptosis through Mas/PKA/p-CREB/UCP-2 pathway after SAH. Furthermore, our study indicates that Mas may be a novel therapeutic treatment target in early brain injury of SAH., Graphical abstract fx1, Highlights • Mas axis of brain RAS was suppressed after SAH. • AVE 0991 reduces neuronal apoptosis and degeneration induced by SAH. • AVE 0991 improves neurological impairments after SAH. • The anti-apoptotic effect of AVE 0991 was mediated through Mas/PKA/CREB/UCP-2 pathway.

The effects of Zr and Si co-substitution on the magnetic properties, oxidation and corrosion resistances of TbCu 7 -type Sm–Co alloys have been investigated. Zr addition is very effective in promoting the formation of TbCu 7 -type structure and it contributes to the most of the coercivity enhancement. The largest coercivity of 1389 kA/m was obtained for SmCo 6.3 Zr 0.4 Si 0.3 alloy. Si addition can significantly improve the oxidation resistance. After exposure in air at 500 °C for 90 h, the thickness of the oxidation layer was just 106 μm for as-cast SmCo 6.4 Zr 0.3 Si 0.3 alloy compared to 230 μm for the SmCo 6.7 Zr 0.3 alloy. The room temperature coercivity of SmCo 6.4 Zr 0.3 Si 0.3 ribbon is as high as 884 kA/m after exposure at 300 °C in air for 10 min. The improved corrosion resistance for Si added alloys was also confirmed by polarization curve measurement. Zr and Si co-substitution provides a good approach for enhancing both the coercivity and resistances to oxidation and corrosion of the TbCu 7 -type Sm–Co alloy.

The effects of carbon addition on the structure and magnetic properties of rapidly quenched TbCu 7 -type SmCo 6.4 Si 0.3 Zr 0.3 alloy have been investigated. The alloys with a small amount of C addition ( x ≤0.2) showed single Sm(Co, M ) 7 phase, while ZrC phase appeared in the alloys with x =0.3 and 0.4. With the increase of C content, the grain size decreased from approximately 850 nm for x =0.1 to approximately 300 nm for x =0.4. The coercivity H c and maximum magnetic energy product ( BH ) max increased with the C content from x =0 to 0.2 and then decreased with excessive C addition. The optimal magnetic properties of H c =1577 kA/m, J r =0.53 T and ( BH ) max =52.1 kJ/m 3 were achieved for SmCo 6.4 Si 0.3 Zr 0.3 C 0.2 alloy with a grain size of 600–700 nm, which is close to the single domain size of TbCu 7 -type Sm(Co,Zr) 7 alloy. Furthermore, C addition also improved the thermal stability by reducing the absolute values of temperature coefficients of remanence and coercivity.

The transverse momentum dependent nuclear modification factors (NMF), namely $R_{CP}$, is investigated for protons produced in Au + Au at 1$A$ GeV within the framework of the isospin-dependent quantum molecular dynamics (IQMD) model. It is found that the radial collective motion during the expansion stage affects the NMF at low transverse momentum a lot. By fitting the transverse mass spectra of protons with the distribution function from the Blast-Wave model, the magnitude of radial flow can be extracted. After removing the contribution from radial flow, the $R_{CP}$ can be regarded as a thermal one and is found to keep unitary at transverse momentum lower than 0.6 GeV/c and enhance at higher transverse momentum, which can be attributed to Cronin effect., Comment: 8 pages, 5 figures; aceepted by Physics Letters B

Nanocomposite FePt–Si–N thin films consisting of magnetic L10 FePt nanograins and non-magnetic Si–N matrix for high density recording medium are developed in this work. The (FexPt100-x)100-ySiy–N films (x = 50–65 and y = 0–10) were fabricated on Si (100) substrates by dc reactive magnetron sputtering followed by vacuum annealing. The maximum value of coercivity around 15.3 kOe was obtained in the film with atom ratio Fe:Pt = 55:45. To achieve a high coercivity, the concentrations of Si and N also have to be properly controlled. Doping Si–N improves the coercivity of FePt film through weakening the exchange coupling interaction. Si and N also play an important role in reducing average grain size of the magnetic particles and smoothing the surface of the films. Transmission electron microscopy demonstrated the nanogranular structure consisting of FePt nanoparticles embedded in the amorphous Si–N matrix.

The hot deformation behavior of a nickel based P/M superalloy by spray forming and hot isostaticpressingwas investigated by isothermal compression test at Gleeble 3500 thermal mechanical simulator. The compression test was performed in the temperature ranging from 1025°C to 1150°C and in the strain rate ranging from 10-1/s to 10-3/s. The results show that the flow curves of true stress and true strain exhibit typical dynamic recrystallization and dynamic recovery. Compression temperature and strain rate have a strong effect on the dynamic recrystallization grain refinement.With higher strain rate the refined dynamic recrystallizationmicrostructure can be obtained at deformation temperature lower thanγ′solution temperature. Grain coarsening occurs at the deformation temperature close to γ′solution temperature, and the grain grows up obviously with decreasing strain rate.

A novel wind energy harvester is proposed and studied in this paper. The system contains a vibro-impact (VI) dielectric elastomer generator (DEG) that can convert vibrational energy into electrical one through the impacts of a rigid ball inside. The VI DEG is embedded into a cuboid bluff body connecting to a galloping-based system. Thus, wind energy is converted to the vibrations of the bluff body, which are further harvested by the DEG. The dynamic and electrical behaviors of the proposed system under wind environments are analyzed theoretically, whereas some key parameters of the system are identified experimentally, including a wind tunnel test for the bluff body and material tests for the dielectric elastomer membrane. The dynamic and electrical outputs of the system under different wind speeds are studied through numerical simulations. The influences of the wind speed and some system parameters on the system energy harvesting (EH) performance are further discussed. Thus, the priority of the proposed system in wind EH is presented and some effective solutions to design the system and improve the system EH performance are proposed.

Background Neuron apoptosis plays a vital role in early brain injury (EBI) after subarachnoid hemorrhage (SAH). Previous studies showed that the activation of G protein-coupled receptor 30 (GPR30) with GPR30 agonist G1 was anti-apoptotic after experimental trauma brain injury and global cerebral ischemia in male rats or mice. However, the role of GPR30 activation with G1 has not been clarified in SAH. The aim of this study was to investigate the anti-apoptotic effect of GPR30 activation and the underlying mechanism of src/EGFR/stat3 signaling pathway in a male rat model of SAH. Methods A total of 215 male rats and 18 female rats were used. SAH was induced by intravascular perforation. G1 was administrated intravenously 1 h after SAH. For mechanism study, the GPR30 antagonist G15 or epidermal growth factor receptor (EGFR) antagonist AG1478 was administrated intravenously 1 h before SAH, small interfering ribonucleic acid (siRNA) for GPR30 and EGFR were administered intracerebroventricularly 48 h before SAH. Post-SAH assessments included SAH Grade, neurological deficits, western blot, terminal deoxynucleotidyl transferase dUTP-biotin nick end labeling (TUNEL) staining, Fluoro-Jade C (FJC) staining, Nissl staining and immunofluorescence. Results The expression of endogenous GPR30 in male rats was increased at 3 h and peaked at 24 h after SAH, which mainly co-localized with neurons, but there was no significant increase in intact female rats at 24 h after SAH. The G1 post-treatment significantly reduced the short-term and long-term neurological deficit as well as neuronal apoptosis in male rats, but it did not significantly improve the short-term outcome of intact female rats. Mechanistic studies indicated that G15 or GPR30 siRNA and AG1478 or EGFR siRNA reversed the anti-neuronal apoptosis effects of G1 and its effects on protein expressions of src/EGFR/stat3 signaling pathway. Conclusion G1 reduced EBI through attenuating neuronal apoptosis after SAH in male rats, partly via activating src/EGFR/stat3/signaling pathway. G1 may provide a promising therapeutic strategy for SAH patients.

Objective To discuss the microsurgical anatomy of the carotid bifurcation and the external branch of the superior laryngeal nerve (EBSLN), and to explore the operative techniques in carotid endarterectomy. Methods The carotid bifurcation of 10 cadaveric heads were studied by using microanatomy. We measured the distance. Results The vertical distance from carotid bifurcation to larynx point and mandibular angle was 24.32 (18.8 ~ 35.78)mm and 13.55 (9.26 ~ 19.60 ) mm. The straight distance from carotid bifurcation to mastoid tip was 68.59 (49.48 ~ 76.94)mm respectively. According to the vertical distance of the larynx point to the carotid bifurcation, the height of the bifurcation of the carotid artery was consistent with the results of the Wain measurement (K = 0.90), the difference was statistically significant (P Conclusion The position of the laryngeal prominence is fixed, which can be used as a marker for surgical incision. In patients with normal carotid bifurcation, 1.5 cm of the carotid artery bifurcation can be used as a safety mark limit during the operation. For patients with high carotid artery, the EBSLN is almost parallel to or down the superior thyroid artery and there is no safety margin.

IN738LC is an important high performance Ni-based superalloy. Its additive manufacturing via selective laser melting (SLM), however, is rather challenging due to the cracking-prone nature of the alloy whose chemical composition contains high amount of alloying elements namely Ti and Al. We address this significant problem by this study through systematic investigations on the pre-processing, SLM optimization, and post-processing of the material, as well as using advanced analytical tools such as micro-CT. A comprehensive process map for achieving crack-free, high-density samples (∼99.76%) is provided. Mechanisms influencing densification, cracking and mechanical properties are discussed. Excellent mechanical properties have been achieved at both room temperature (895/1010 MPa as the yield and tensile strengths) and elevated temperature of 850 °C (720 MPa tensile strength and 14.4% elongation). A demonstrative as-printed turbine blade is also presented, highlighting the capability of SLM to simultaneously achieve excellent mechanical property and good geometric integrity.

The effects of wheel speed, Zr content, post-ball milling process and heat treatment on the structure, anisotropy, magnetic properties and phase transition of the melt-spun SmCo7−xZrx alloys were investigated. The crystallographic c-axis is parallel to the ribbon plane for the ribbons prepared at low speeds of 5 and 15 m/s, and this orientation is reduced at higher speeds. The out-of-plane coercivity of SmCo6.8Zr0.2 ribbon increases from 123 kA/m for 5 m/s to 1076 kA/m for 60 m/s. Zr doping improves the hard magnetic properties and the in-plane coercivity of SmCo7−xZrx alloys increases with the Zr content from 592 kA/m for x=0.1 to 1376 kA/m for x=0.4. The Rietveld refinements and theoretical analysis reveal that Zr atoms occupy the 2e site. The coercivity mechanisms are different for the alloys with various Zr contents. The ball milling process could enhance the coercivity and remanence of the ribbons due to the grain refinement and the precipitation of Co phase. Heat treatment can further modify the magnetic properties of the alloys. SmCo6.7Zr0.3 alloy heat treated at 400 °C has the high maximum energy product (BH)max of 64.5 kJ/m3, where the coercivity was enhanced to 1560 kA/m by 650 °C heat treatment. In addition, the SmCo7−xZrx alloys exhibit excellent hard magnetic properties at elevated temperatures.

FePt–Si–N films consisting of FePt nanoparticles embedded in Si–N matrix were fabricated on Si(100) substrates by dc reactive magnetron sputtering followed by vacuum annealing. The effects of film thickness, Fe/Pt atomic ratio, and Si, N additions on the structure and magnetic properties were investigated. Perpendicular orientation can be obtained in the film with small thickness. Fe content also has an important effect on the film orientation. The ordering temperature for FePt–Si–N films is 100 °C higher than that of FePt films. Both FePt and FePt–Si–N films have the highest coercivity at Fe content of 55 at%. Doping Si and N can improve the coercivity of FePt film through weakening the exchange coupling and reducing the grain size. To achieve high coercivity in FePt–Si–N film, the Si/N atomic ratio has to be well controlled.

A compositional dependence on the ferroelastic phase transition in scheelite solid-solution [(Li 0.5 Bi 0.5 ) x Bi 1− x ][Mo x V 1− x ]O 4 ceramics was characterized by the microwave dielectric data over the temperature range 10–420 K. As x values increased from 0.0 to 0.125, a dielectric temperature-dependent anomaly consistent with a phase transition decreased linearly from 528 K for the pure BiVO 4 end member to 264 K for the solid-solution composition at x = 0.125. With further increasing x , the transition temperature decreased sharply to approximately 45 K and became stable for x ⩾ 0.52. The phase transition point for pure tetragonal (Li 0.5 Bi 0.5 )MoO 4 ceramics is approximately 43 K. As the x value increases, the Raman band of the [(Li 0.5 Bi 0.5 ) x Bi 1− x ][Mo x V 1− x ]O 4 ceramics at room temperature broadens and overlaps. Ferroelastic domain structures were observed as a function of composition with diffraction contrast imaging and high-resolution imaging with transmission electron microscopy. Structure–property relations are inferred from the microscopy observations and the Raman spectra.

In this paper we present the experimental results of a silicon photomultiplier (SiPM) with bulk integrated quenching resistors on epitaxial silicon. Compared with existing SiPM with polysilicon quenching resistors on the surface or with MRS structure, it has potential advantages of high photon detection efficiency (PDE) while retaining a large micro-cell density and the fabrication process is also simplified. The SiPM with the micro-cell density up to 10 4 /mm 2 and the PDE up to 25.6% is demonstrated. The characteristics of dark count rate, single photon detection capability, gain, optical crosstalk and PDE have been investigated and discussed.

An avalanche drift detector with photon counting capability is proposed and demonstrated. It combines the drift structure with a “point-like” Geiger mode avalanche diode, which is used as the collecting electrode. The diameters of the front entrance window and the avalanche diode of the fabricated detector are 294 and 10 μm, respectively, and the thickness of the whole depletion region is below 10 μm. Experimental results show that the dark count rate is 19.34 kHz at room temperature and is reduced to 2.78 kHz when the temperature decreases to −40 °C. When the light pulse frequency is below the saturation value of 140 kHz at room temperature, the average increase of the electrical signal frequency is about 3.5 kHz with a 10 kHz increase of the light pulse frequency.

We present a numerical method to describe the transport of ions through polymeric electrolytes under the influence of an applied electrostatic field. The transport of ions results in an ion concentration profile with a large gradient near charged interfaces, the so-called diffuse layer. We show that the Poisson–Nernst–Planck theory, which generally describes the transport of ions, can be simplified significantly if the dimensions of the bulk material are much larger than the thickness of the diffuse layer. In this case, charge transport through the bulk of the material is driven by the electric field only (Ohm's law). At all interfaces an analytical mathematical relation between the surface charge and the voltage difference over the diffuse layer can be used. Several of these relations are used, including relations that account for ion volume effects. We use experimental data from literature [J.A. van der Pol, R.T.H. Rongen, H.J. Bruggers, Microelectron. Reliab. 40 (2000) 1267] of charge accumulation at the surface of an integrated circuit (IC) resulting from the transport of ions through the polymeric material encapsulating the device. The data are very well described by a two-dimensional finite element model based on the simplified Poisson–Nernst–Planck theory. In addition, the theory predicts that the accumulated charge at the circuit interface will slowly drain away after having reached the experimentally observed maximum.

The hot deformation behavior of a nickel-based superalloy processed by spray forming and hot isostastic pressing has been studied by compression tests. It is found that the alloy exhibits an excellent hot-workability compared to its conventionally cast counterpart. Also, the result shows that the higher the strain rate used, the better is the deformability of the material. By using the experimentally available data, the constitutive relationship for describing the hot deformation behavior of the studied alloy is established.

The limited plasticity of bulk metallic glasses (BMGs) is commonly circumvented by introducing micrometer- or nanometer-sized heterogeneities (crystallites and/or phase separation) into the BMGs. In this work, we report the improvement of plasticity in a ternary monolithic BMG caused by a large amount of randomly distributed free volume induced during solidification using a high cooling rate. This indicates that introducing large amounts of free volume into BMGs might be another promising way of improving the plasticity of these materials.

We propose an amorphous/porous molecular connection network generation algorithm for simulating the material stiffness of a low-k material (SiOC:H). Based on a given concentration of the basic building blocks, this algorithm will generate an approximate and large amorphous network. The molecular topology is obtained by distributing these blocks randomly into a predefined framework. Subsequently, a structural relaxation step including local and global perturbations is applied to achieve the most likely stereochemical structure. Thus, the obtained mechanical properties of the low-k materials have been verified with the experimental data.

Substrate transfer technology for SOI and non-SOI single-crystalline silicon wafers was demonstrated allowing for high-performance low-power RF applications. 3D deformable electronics could be realized by vertically thinning and laterally partitioning of the silicon substrate on sub-millimeter scale. By varying the partition dimensions and the geometry of connecting bridges, the level of acceptable deformations can be controlled. The targeted applications of this technology are wireless ID tags and sensor networks. The mechanical properties such as crack, interfacial delamination are critical to reach the flexible substrate. In this contribution, results of our work on mechanical reliability issues of poly- and single crystalline silicon on ultra-thin polyimide substrates are presented. To improve reliability, square and hexagonal segmentation with different size is applied to the silicon layer before it is transferred onto an ultra-thin polyimide substrate using wafer-to-wafer substrate transfer technique based on a temporary glass carrier. Generation of cracks within the silicon and dielectric layers is then studied under controlled bending and tensile loads. The formation of cracks is studied experimentally using specially for this purpose designed bending and tensile tools. Ultra-thin interfacial delamination are also focused in this work by experimental and FE simulation method. A new test setup is designed for mixed mode bending testing which has capacity to observation specimen and recording the crack length and crack opening by microscope. The critical energy release depended on mixed angle can be reach by combination experimental data with FEM simulation.

Pattern shift is one of the main failures of micro-electronics. In this paper, the influence of plastic deformation values of micro-structures of IC packages on the pattern shift of metal lines is studied by maximum plastic strain theory using a certain 2D FEM model with different design parameters, “d”, “w”, “t_epo”, “t_Teos”, “t_glue” “sy_glue” and “sy_al”. For different critical process step, the final process temperature is acted as a representative parameter to analyze its impact. Furthermore, Response Surface Model (RSM) of plastic strains is established using any two design parameters. Results show that “w”, “t_epo”, “t_Teos”, “t_glue” “sy_glue” and “sy_al” will have different influence on pattern shifting while “d” have little impact.

In order to exploit new strategies for fabricating high-temperature superconductors with special morphologies and investigate the effects on their superconductivity, we successfully utilized a facile polyol process for fabricating a large amount of La2CuO4 (LCO) microspheres using La(CH3COO)3·1.5H2O and Cu(CH3COO)2·H2O as raw materials and ethylene glycol as both complex agent and solvent. The well crystallized LCO microspheres can be obtained by annealing the La-Cu-complex precipitation formed after refluxing process at 750 oC for 10 hours. Field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) results indicated that the as-prepared sample had an average diameter of about 800 nm. The powder X-ray diffraction (XRD) patterns showed that the LCO microspheres were of pure phase. The magnetization measurement of the sample annealed at 900 oC in pure oxygen for 20 hours showed that the superconducting transition temperature (Tc) of the LCO microspheres was about 38 K, which in agreement with that of bulk counterparts.

Large scale and highly ordered thermoelectric BixTe1-x (0.4 ≤ x ≤ 0.7) nanowire arrays were successfully fabricated by cathodic electrolysis into porous anodic alumina membrane (AAM) templates in aqueous solution. The structure of the nanowires was characterized by X-ray diffraction and selected-area electron diffraction (SAED). Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) results show that the nanowires are smooth and uniform with the diameters of about 50 nm and lengths up to tens of micrometers. Energy dispersive spectroscopy (EDS) was used to check the exact stoichiometry of as-prepared samples. The results reveal that the atomic ratio between Bi and Te can be modulated effectively by controlling the concentration of the electrolyte solution. The synthesis of high quality BixTe1-x nanowires with controllable x is significant for optimizing the thermoelectric performance.