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International audience; Four novel heptanuclear Ln–Cu complexes with the formula [Ln2Cu(hfac)8(NITPhTzbis)2][LnCu(hfac)5(NITPhTzbis)]2 (LnCu = YCu 1, TbCu 2, DyCu 3 and HoCu 4; hfac = hexafluoroacetylacetonate) were successfully constructed by employing the triazole functionalized nitronyl nitroxide biradical ligand NITPh-Tzbis (NITPh-Tzbis = 5-(1,2,4-triazolyl)-1,3-bis(1′-oxyl-3′-oxido-4′,4′,5′,5′-tetramethyl-4,5-hydro-1H-imidazol-2-yl)benzene). These hetero-tri-spin complexes are composed of two biradical-bridged dinuclear [(LnCu(hfac)5(NITPhTzbis)] units and one trinuclear [Ln2Cu(hfac)8(NITPhTzbis)2] unit which form a heptanuclear supramolecular structure through π–π interactions. Magnetic susceptibility investigations indicate that ferromagnetic exchange interactions dominate at low temperature for this supramolecular system which can be attributed to the Ln–nitroxide exchange and intramolecular NIT⋯NIT coupling mediated by the m-phenylene moiety. The DyCu derivative was found to exhibit a slow magnetic relaxation behavior.

International audience; Employing the new nitronyl nitroxide biradical ligand biNIT-3Py-5-Ph (2-(5-phenyl-3-pyridyl)bis(4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide)), a 16-spin Cu-radical complex, [Cu 8 (biNIT-3Py-5-Ph) 4 (hfac) 16 ] 1, and three 2p-3d-4f chain complexes, {[Ln(hfac) 3 ][Cu(hfac) 2 ] 2 (biNIT-3Py-5-Ph) 2 } n (Ln III = Gd 2, Tb 3, Dy 4; hfac = hexafluoroacetylacetonate), have been prepared and characterized. X-ray crystallographic analysis revealed in all derivatives a common cyclic [Cu-biNIT] 2 secondary building unit in which two bi-NIT-3Py-5-Ph biradical ligands and two Cu II ions are associated via the pyridine N atoms and NO units. For complex 1, two such units assemble with four additional Cu II ions to form a discrete complex involving 16 S = 1/2 spin centers. For complexes 2-4, the [Cu-biNIT] 2 units are linked by Ln III ions via NO groups in a 1D coordination polymer. Magnetic studies show that the coordination of the aminoxyl groups with Cu or Ln ions results in behaviors combining ferromagnetic and antiferromagnetic interactions. No slow magnetic relaxation behavior was observed for Tb and Dy derivatives.

We estimated the lift and thrust of the proto-wings of the dinosaur Caudipteryx, a close relative of birds, using both theoretical and experimental approaches. Our experiments utilized a newly reconstructed flapping wing mechanism in accordance to the fossil specimens of Caudipteryx. To ensure that this reconstructed mechanism could adequately simulate the realistic flapping movements, we investigated the relationships among the flapping angle, twisting angle, and stretching angle of the wing mechanism that was driven by a DC motor. We also used two sensors to measure the lift and thrust forces generated by the flapping movements of the reconstructed wing. Our experiment indicated that both the lift and thrust forces produced by the wings were small but increased at higher flapping frequencies. This study not only contributes to current understanding of the origin of avian flight but also usefully informs the ongoing development of bionic flapping robots.

The ride comfort, driving flexibility and stability, and operation safety all directly or indirectly depend on the suspension mechanism. Therefore a suspension system defines, in a certain degree, the vehicle’s performance. Traditional longitudinal spring suspension system occupies a large space which is not beneficial either to enlarging the steering angle or to the layout of vehicle chassis. This paper therefore proposes a suspension mechanism within which there are four identical single leaf-springs assembled in parallel. Thus the suspension forms a statically indeterminate oblique structure which improves the stiffness, strength, and reliability while reducing its total mass. The oblique arrangement of the leaf-springs allows the suspension to occupy smaller space which therefore provides larger steering angle for a vehicle. Experiments with real vehicles proved that this kind of suspension should also improve the dynamic performance as it reduces the suspension mass due to the redundant leaf-springs. Therefore, the oblique leaf-spring suspension mechanism can enhance the ride comfort, handling flexibility and stability, and driving safety of a vehicle.

Purpose The identification of infection at its early stage in vulnerable patients is challenging. This study aimed to investigate potential biomarkers to distinguish patients progressing to severe sepsis from those with uncomplicated sepsis. Materials and methods Serum samples were collected from sepsis patients admitted to the emergency department. The mRNA and protein levels of angiopoietin-2 (Ang-2), interleukin-10 (IL-10), heparin-binding protein (HBP), procalcitonin (PCT), adrenomedullin (ADM), and interleukin-6 (IL-6) were evaluated. Results Compared to those of healthy individuals (n = 47), mRNA levels of ANG2, IL10, HBP, PCT, and ADM were increased in patients who eventually developed sepsis. ANG2 was the only gene whose expression was significantly increased in patients developing severe sepsis than in those with uncomplicated sepsis. Serum levels of Ang-2, IL-10, HBP, PCT, and IL-6 were also increased in sepsis patients, but only Ang-2, HBP, and PCT were elevated in the serum of patients developing severe septic shock than in those with uncomplicated sepsis. Serum levels of Ang-2, HBP, and PCT were closely associated with the sequential organ failure assessment (SOFA) score of the patients. Conclusions These findings indicated that sustained elevation of Ang-2, HBP, and PCT were associated with severe infection in critically ill patients.

Inspired by green plants, artificial photosynthesis has become one of the most attractive approaches toward carbon dioxide (CO2 ) valorization. Semiconductor quantum dots (QDs) or dot-in-rod (DIR) nano-heterostructures have gained substantial research interest in multielectron photoredox reactions. However, fast electron-hole recombination or sluggish hole transfer and utilization remains unsatisfactory for their potential applications. Here, the first application of a well-designed ZnSe/CdS dot-on-rods (DORs) nano-heterostructure for efficient and selective CO2 photoreduction with H2 O as an electron donor is presented. In-depth spectroscopic studies reveal that surface-anchored ZnSe QDs not only assist ultrafast (≈2 ps) electron and hole separation, but also promote interfacial hole transfer participating in oxidative half-reactions. Surface photovoltage (SPV) spectroscopy provides a direct image of spatially separated electrons in CdS and holes in ZnSe. Therefore, ZnSe/CdS DORs photocatalyze CO2 to CO with a rate of ≈11.3 µmol g-1 h-1 and ≥85% selectivity, much higher than that of ZnSe/CdS DIRs or pristine CdS nanorods under identical conditions. Obviously, favored energy-level alignment and unique morphology balance the utilization of electrons and holes in this nano-heterostructure, thus enhancing the performance of artificial photosynthetic solar-to-chemical conversion.

This study aims to evaluate the role of chymostatin in paraquat-induced acute lung injury. Institute of Cancer Research mice were randomly distributed into the NS, DMSO, chymostatin, paraquat or chymostatin treatment groups. Six mice from each group were intraperitoneally injected with chloral hydrate at 0, 1, 2, 4, 8, 12, 24 and 48 h after treatment administration. Blood samples were collected through cardiac puncture. Lung tissues were stained with haematoxylin and eosin for the observation of lung histology. The degree of pulmonary oedema was determined on the basis of lung wet-to-dry ratio (W/D). The serum activity of cathepsin G was determined through substrate fluorescence assay. The serum levels of endothelial cell-specific molecule-1 (endocan), tumour necrosis factor-a (TNF-a), interleukin-1β (IL-1β), IL-6 and high-mobility group box protein 1 (HMGB1) were determined through enzyme-linked immunosorbent assay. The expression levels of endocan and nuclear NF-κBp65 in the lung were quantified through Western blot. Chymostatin alleviated the pathological changes associated with acute alveolitis in mice; decreased the lung W/D ratio, the activity of cathepsin G and the serum concentrations of TNF-a, IL-1β, IL-6 and HMGB1; and increased the serum concentration of endocan. Western blot results revealed that chymostatin up-regulated endocan expression and down-regulated nuclear NF-κBp65 expression in the lung. Chymostatin reversed the inflammatory effects of paraquat-induced lung injury by inhibiting cathepsin G activity to up-regulate endocan expression and indirectly inhibit NF-κBp65 activity.

Interleukin-17A (IL-17A) is involved in multiple inflammatory diseases. Our study was to investigate the role of IL-17A on acute lung injury (ALI) respectively induced by lipopolysaccharide (LPS) and paraquat (PQ) on mice. We built ALI mouse models respectively by single intraperitoneal (i.p.) injection with LPS or single gavage with PQ liquid. Two hours after the models were established, a dosage of neutralizing antibody was used to blockade IL-17A by i.p. injection. At 8, 24, and 48 h, the lung wet-to-dry ratio (W/D) was calculated and total protein in bronchoalveolar lavage fluid (BALF) was measured; hematoxylin-eosin staining was used to observe lung tissue pathological changes; inflammatory cells in BALF were recorded with a hemocytometer; cytokines were measured with enzyme-linked immunosorbent assay kits; immunohistochemistry examined the expression of IL-17A and activation of nuclear factor-κB p65 (NF-κB p65); and qPCR determined the expression of IL-17A mRNA. After being administered with LPS or PQ, all mice presented ALI pathological change; expression of IL-17A increased significantly. When blocking IL-17A with antibody, lung injury in both LPS- and PQ-administrated mice was attenuated. All the above tests decreased. Compared with those in PQ mice, IL-17A levels in LPS mice were higher. IL-17A involves the ALI induced by LPS or PQ and promotes the pathological process by activating NF-κB P65 and recruiting neutrophils, which enlarges the cascade effect of inflammation and injures lung tissues. And when blockading IL-17A with antibody, the ALI is alleviated. The reaction of IL-17A in the ALI induced by LPS is stronger than that by PQ.

Objective: Methods containing only clinical information fail to meet the needs of prediction of acute lung injury (ALI) because of the relatively low positive predictive value. This study aimed to investigate the feasibility of using biomarkers as predictors of ALI in populations with severe sepsis/septic shock and to explore difference among biomarkers after adjustment for potential confounders. Methods: Serum specimens were collected from patients with severe sepsis/septic shock (n = 172) presented to the emergency department. Patients should be ruled out from the study if they were already suffering from ALI or if they deteriorated into ALI within 6 hours after specimen collection. The development of ALI of the remaining patients was tracked. Results: Of all patients with severe sepsis/septic shock who encountered ALI more than 6 hours succeeding to specimen collection, 19 deteriorated into ALI. Elevation in serum interleukin 8 (IL-8) and Parkinson disease 7 (PARK7) levels had significant connection with higher risk of developing ALI ( P = .006; P = .0001). Sepsis treatment and vasopressor application led to a robust connection between PARK7 and succeeding ALI development. Patients who deteriorated into ALI were distinguished accurately from patients who avoided ALI using PARK7 or Lung Injury Prediction Score (LIPS; area under the receiver operating characteristic curve [AUROC], 0.73 and 0.72 for each). Combination of PARK7 and LIPS ameliorated AUROC to 0.86 (vs 0.73, P = .05). On the contrary, serum soluble receptor for advanced glycation end products and von Willebrand factor made no contribution to the prediction of ALI development. Conclusions: Patients with PARK7 or IL-8 levels above normal are more vulnerable to ALI. Patients vulnerable to ALI can be distinguished with the combination of serum biomarkers and clinical prediction scores. In addition, the early rise in PARK7 emphasizes the importance of endothelial injury in the early pathogenesis of ALI.

This paper studies on the frost resistance of high-content fly ash concrete which content 52 fly ash in seawater. The uniaxial compressive property test was carried out after the fast freeze-thaw test with 0, 100, 200, 300 and 400 cycles. The research analyzed the influence of the uniaxial strength of the concrete mixed with high-content fly ash after freeze-thaw cycles in seawater. Then established a mathematical expression in a simple way. In the real project, the concrete mixed with fly ash can improve the frost resistance. The dosage of fly ash will directly influence the frost resistance and mechanical property. However, there is less study on frost resistance of concrete mixed with fly ash, especially the test under the seawater environment.

With the development of production and technology, the devices of oil refining, chemical, fertilizer and others are progressing to the direction of high parameters (high pressure, high temperature). Pressure vessels must be open, which will made the stress concentration problems more serious, and traditional design methods derived from empirically formula fails to meet the actual demand. In this paper, a theoretical result is calculated with a simplified model of the opening holes in cylindrical shell, verified by a group of solutions got by the ANSYS simulation. And it turns out that the result is rather satisfactory.

In this study, we reported on the construction of p–n junctions based on crystalline Ga-doped CdS–polycrystalline ZnTe nanostructures (NSs) for optoelectronic device application. The coaxial nano-heterojunction was fabricated by a two-step growth method. It is found that the absorption edge of CdS:Ga–ZnTe:Sb core–shell NSs red shifted to about 580 nm, compared with CdS nanowires (520 nm). The as-fabricated core–shell p–n junction exhibited obvious rectification characteristics with a low turn-on voltage of ∼0.25 V. What is more, it showed stable and repeatable photoresponse to 638 nm light illumination, with a responsivity and a detectivity of 1.55 × 103 A W−1 and 8.7 × 1013 cm Hz1/2 W−1, respectively, much higher than other photodetectors with similar device configurations. The generality of this study suggests that the present coaxial CdS:Ga–ZnTe:Sb core–shell nano-heterojunction will have great potential applications in future nano-optoelectronic devices.

Health monitoring of civil engineering has been widely required in construction, operation and service-life prediction. FBG sensors, a kind of the most efficient sensing elements, for the superior advantages of small size, high sensitivity, long-term stability and durability, good geometrical shape-versatility, corrosion resistance and anti-electromagnetic interference, are highly applied in different engineering fields. Measurement precision of this sensor is paid attention and strain transfer analysis is developed to give an explanation on the testing mechanism and provide the quantitative strain transfer error modification functions. Theoretical derivation on strain transfer analysis of sensors with debonding interface is executed and related functions have been offered to eliminate the strain transfer error. Research in this article is meaningful for improving the precision of FBG sensors with debonding interface, which is helpful for much long-term detection of structures.

In order to illustrate the mechanism of supporting, maintain the safety and keep the stable of underground projects, it is of great significance to study the transverse effect of bolted discontinuous rock mass. With a 3D model and corresponding physical simulation, analyzing the testing results of the bolt stress, rock stress and displacement discovers some new findings. Besides its reinforcing effect to the rock mass, the bolt has a negative effect on the discontinuous rock mass by its so-called ‘railway effect’ under shear loading. The finding of this bolt function will help to further understand of bolting mechanism and it is very important to raise the safety of bolt supporting design. Furthermore the effect grade is a positive correlativity with the bolt diameter, and the shear displacement is one of its necessary conditions.

Terzaghi equation is widely used in practice to determine Ultimate Bearing Capacity (UBC). Recent research indicates that exact solution of UBC could be got with the slip line method if the soil is ideal elastic-plastic material. In this paper, dimensionless UBC is gained using ABC software based on the slip line method and is compared with that by Terzagh equation with based on empirical formula. It shows that error of UBC is caused by empirical formula. However, the accuracy of UBC relates to safety and economy of the engineering. Given empirical formulas have a wide application in practice, the scope of application of the four classic empirical formulas is discussed in different range of allowable error. The applicable scope of the four classic empirical formulas within the margin of error is discussed and the results can facilitate the application of classic empirical formulas in practice.

The experiments of concrete in seawater under 0, 25, 50, 75 and 100 freezing-thawing cycles were performed using fast freezing and thawing method. Appling large concrete static and dynamic triaxial test system, the influence of freezing and thawing cycles on compressive strength and strain at peak stress point of concrete in seawater were detected, and then simple mathematical expressions were established.

ZnS0.59Se0.41 alloy nanowires were prepared on gold-coated Si substrates by the thermalevaporation of a mixture of ZnSe and ZnS powders. Field-effect transistors (FETs) constructed fromthe ZnS0.59Se0.41 NWs verified their p-type nature with a hole concentration of 3.1×1018 cm-3.Inaddition,the photoresponse indicates their potential for photoelectric applications.

Mechanical properties experiments of concrete after 0, 25, 50 and 75 freeze-thaw cycles under uniaxial and multiaixial compression were carried out. The uniaxial and multiaxial compressive strengths of ordinary concrete after freeze-thaw cycles were measured. According to the experiment results, the influence of freeze-thaw cycles on the ultimate compressive and tensile strength was analyzed systematically. The influence law of freeze-thaw cycles on compressive strength of concrete under multiaxial compression was obtained. The results indicate that the compressive strength of ordinary concrete after freeze-thaw cycles under multiaxial compression is higher than that under uniaxial compression, and the degree of improvement is depended on its stress ratio. This conclusion can propose theoretical foundation for design of concrete structures in cold environment

Applications of one-dimensional (1D) semiconductor nanostructures in nanoelectronics and nano-optoelectronics rely on the ability to rationally tune their electrical transport properties. Here we report the synthesis of single-crystalline Ag-doped ZnSe nanowires (NWs) by using silver sulfide (Ag2S) as the p-type dopant via a thermal evaporation method. The ZnSe:Ag NWs had the zinc blende structure with [11 ] growth orientation. Significantly, the conductivities of the NWs could be tuned over 9 orders of magnitude by adjusting the Ag doping levels. Field-effect transistors (FETs) constructed from the ZnSe:Ag NWs verified their p-type nature with a hole concentration of up to 2.1 × 1019 cm−3, which is the highest value achieved for p-type ZnSe nanostructures thus far. Schottky barrier diodes (SBDs) based on the ZnSe:Ag NW/ITO junctions exhibited remarkable rectifying behavior, with a rectification ratio of >107 and a small ideality factor of ∼1.29 at 320 K. Moreover, photovoltaic devices were fabricated from the ZnSe NW array/Si p–n heterojunctions by aligning the p-ZnSe NWs in a parallel fashion on a n-Si substrate. The device with a graphene top electrode showed a large fill factor (FF) of 61%, yielding a power conversion efficiency of ∼1.04%. The realization of p-type ZnSe NWs with tunable conductivity opens up opportunities for a host of high-performance nanoelectronic and nano-optoelectronic devices.

The effects of phosphorus and boron addition on the as-cast microstructure and homogenization parameters of Inconel 718 were studied. The results indicate that the addition of phosphorus and boron promotes the formation of blocky Laves phase. Due to the strong segregation behavior of boron in the final residual liquid, a low melting B-bearing phase enriched in Nb, Mo and Cr is observed. According to the differential scanning calorimeter results and electron probe micro-analysis characterization, the solidification sequence of Inconel 718 with phosphorus and boron addition in best combination is determined as L → L +γ → L +γ+ MC → L +γ+MC+Laves → γ+MC+Laves+B-bearing phase. Accordingly, the homogenization temperature is recommended to be adjusted at least 40°C lower than that of standard Inconel 718 due to the existence of low melting B-bearing phase.

The fly ash and ash of different biomass power plants are selected as research objects, of which the combustion characteristics are studied. At the heating rates of 50°C/min, at the final reaction temperature of 900°C, and under the condition of air as carrier gas, weight loss curve and weight loss rate curve are analyzed respectively. TG, DTG curves of fly ash and ash from different power plant are gained, different combustion conditions are studied, and combustion kinetic equations of different biomass fly ash and ash are established, kinetics parameters are obtained by the Coats-Redfern method. Besides, combustion condition and reburning feasibility of different biomass fly ash and ash are analyzed, which provide a theoretical support for biomass power plant operation, such as improving their fuel burn rate.

A new algorithm which is “the minimum zone evaluation for sphericity error based on the dichotomy approximating” has been presented with the geometric characteristics and research situation of sphericity error and through the understanding of the definition and the evaluation problem of the sphericity. The principle of the algorithm is that based on finding the initial point of the ball as the base, around which the side decorates cube by certain length, calculating the distance of the points on the sphere to the cube measuring points of the eight vertex and the initial point, by comparing and judging to find a new beginning starting point, and arrange new cube repeatedly until meets the requirement. The sphericity error value of corresponding evaluation method (Minimum Zone Sphere method (MZS)) was obtained according to that. The mathematical formula、program flowchart and example verification were given. The example verification results show that the sphericity error can be evaluated effectively and exactly with this algorithm.

This research investigates the mechanical property of the concrete which were mixed with chemical admixtures and treated by magnetic field. Two chemical admixtures were used in this research: Concrete superplasiticizer SW-4 and early strength admixtures CF. Magnetic treated admixtures were obtained by passing liquors through a concrete magnetic-field-generating machine. Test variables included admixture dosage and curing age. Results show that liquor’s conductivity and surface tension have some special changes after treated by magnetic field, and using magnetic treated admixtures could improve the compressive strength of the concrete, reduce the setting times and improve its fluidity and magnetization improved cement hydrate degrees.

Quantitative analysis was employed to establish reasonable and practical homogenization model of INCONEL718 superalloy. Metallographic method was applied to determining the incipient melting temperature. The result shows that the incipient melting temperature of d406 mm INCONEL718 ingot is situated between 1 170 °C and 1 180 °C. In order to predict the elimination process of Laves phase in quantity, a time and temperature dependent homogenization model was proposed. Among all the elements in the as-cast microstructure, Nb and Ti are the most positive segregated elements. The diffusion coefficients of alloying elements at 1 140 °C were obtained by fitting the linear relationship between ln d (d: residual segregation index) and time. The calculation results of diffusion coefficients were compared with other two commercial Nb-bearing superalloys.

The impact resistance of steel fiber reinforced lightweight aggregate concrete was presented in a drop weight test. In this test, 5 groups of disc specimens with different steel fiber volumes including 0.0%, 0.5%, 1.0%, 1.5% and 2.0% were tested. The experimental results indicated that the impact resistance of lightweight aggregate concrete is improved with the increase in fiber volume. As the variation in experimental results, a statistical evaluation was performed to study the influence of impact resistance of steel fiber reinforced lightweight aggregate concrete with different steel fiber volumes. Further more, the impact resistance was simulated with probability distribution by Log-normal method. And the goodnees-of-fit tests indicate that the Log-normal method has good fitness to the impact resistance of steel fiber reinforced lightweight aggregate concrete.

Since high strength of lightweight aggregate concrete leads to increased brittleness, fiber reinforcement should be considered for improving strength and ductility. 5 groups of SFLWC specimens with different steel fiber volumes including 0.0%, 0.5%, 1.0%, 1.5% and 2.0% were tested to investigate the effect of steel fiber content on the static mechanical properties and impact resistance of lightweight aggregate concrete. The static mechanical properties include the prismatic compressive strength, splitting tensile strength, first-crack flexural strength, flexural strength, and flexural toughness, etc. The experimental results indicated that addition of steel fiber can greatly improve such mechanical properties as the splitting tensile strength, flexural strength, flexural toughness and impact resistance, but leads to a little effect on compressive strength. Further more, the author suggests the feasible volume ratio of this kind of steel fiber is 1-1.5%.

Based on numerical simulation of computing Software ANSYS, the curve of arching coefficient variation of pressure arch due to actual mining was analyzed aiming to a special mining face, the law of stress transfer and change in surrounding rock was discussed, and the evolving features and characteristics of pressure arch was obtained. The analysis and discussion show the following facts: Arch body will become thicker and stress in the arch body increases with working face’s driving distance increasing; the morphology of pressure arch transits from ellipsoid with long axis in the vertical direction to ellipsoid with long axis in the horizontal direction along the trend of working face; along the tendency of working face, the morphology of pressure arch is a ellipsoid with long axis in the vertical direction.

One of the most popular pre-reinforcement structures in the construction of tunnels through weak grounds would be the pipe roof reinforcement. This composite structure consists on installing, prior to the excavation of a length of tunnel, a series of pipes, either parallel to the tunnel axis or at a certain angle with it. By injecting grout through the pipes, the ground in between the pipes is stiffened and the pipes are connected, creating a kind of ‘umbrella’ above the area to be excavated. In this paper, by modifying the upper bound solution for tunnel face stability, the three-dimensional model for expressing the tunnel face stability with pipe roof reinforcement was established. For a typical example, the solutions computed by the proposed approach were compared with the results given by wedge model, trapezoid wedge model and centrifugal-model test to verify the reasonability of the method. It is shown that the calculation results of limit analysis are in close agreement with test results.

The solidification process of a conventional superalloy, IN718, was investigated by confocal scanning laser microscope (CSLM). The liquid fraction during solidification was obtained as a function of real time and temperature in reference with the in-situ observation. The characteristics of L→γ transformation were analyzed and the γ growing rate of each stage was also calculated. Scheil equation was employed to predict the segregation behavior, and the predict results are in consistence with the experimental results. As a result, the confocal scanning laser microscope shows a great potential for solidification process research.

Stress wave test technique has broad prospects because of the long distance, large scale and relatively low cost. This paper studies the stress wave propagation characteristics in the butt weld joints in the case of external symmetrical impact. The stress wave propagating before and after the joints is measured by dynamic strain gauge. Then model analysis and simulation is applied to research stress wave. The results show the loss of stress wave is small. After spectrum analysis, the change of propagating stress wave can be detected.

Dynamic Bayesian networks can be well dealt with the time-varying multivariable problem. The state model based on Dynamic Bayesian networks can more accurately describe the relationship between the system state and the influencing factors. In this paper, the width of the reasoning is used to simplify the amount of data in the reasoning process. Multi-step state prediction is achieved by extending time-slice. Experiment has shown that the proposed algorithm can achieve better prediction results.

A new method for manufacturing nanomaterials with high ductility on a large scale is reported here. Based on surface nanocrystallization and warm co-rolling technologies, the resulting material amazingly exhibits high strength and exceptional ductility. Stainless steel was selected to demonstrate the extensibility of our approach. The yield strength (878 MPa) is more than double that of the monolithic material. The elongation to failure (48%) triples comparing with the material with the same yield strength obtained by work hardening.

Hot plasticity of a nitrogen alloyed 25Cr-7Ni-4Mo duplex stainless steel was investigated. The results indicate that the main factors affecting the hot plasticity of duplex stainless steel are listed as follows: coalescent force of phase interface, microstructure, and the phase ratio and difference between the mechanical properties of ferrite and austenite. The heat treatment and sulphur contents have a notable effect on the hot plasticity. The reasonable heat treatments and the increased interfacial coalescent force will effectively enhance the hot plasticity of duplex stainless steel.

The mechanical properties of as-cast and hot-forging duplex stainless steel samples with the same compositions were characterized by nanoindentation. The effect of surface treating method and working state of the sample on the nanoindentation results of ferrite and austenite were discussed. The results show that the Young’s modulus and hardness of ferrite and austenite may be affected by the treating method of sample surface. The difference of Young’s modulus average of ferrite or austenite between as-cast and hot-forging duplex stainless steel samples is not great, but the hardness average of ferrite or austenite in hot-forging sample is obviously higher than those of as-cast sample. The difference of hardness between ferrite and austenite in the same sample is not great, but the young’s modulus of ferrite is higher than that of austenite.

In the present work, low carbon low alloy submicro-steel sheet has been developed successfully by severe warm-rolling (SWR) at 500 °C through a single pass. The result shows submicro-structure can be fabricated by severe rolling. The formation of the submicro-structure is attributed to the grain refinement mechanism induced by the severe plastic deformation (SPD). The refinement involves the cutting and subdividing of the original micro-crystals into ultrafine grains by dense dislocation arrays. To a certain extent, dynamic recrystallization in ferrite during SWR also seems to contribute to the formation of the submicro-structure. The thermal stability of the submicro-steel was investigated by annealing the steel at different temperatures. The investigation indicated that the submicro-steel can be subjected to annealing at 550°C without apparent grain growth. The unusually high thermal stability can be attributed to the pining effect of numerous uniformly distributed nano-precipitates in the steel. The sizes of the nano-precipitates belong to two different orders. The average diameter of the large precipitates is about 30 nm and the smaller one less than 10 nm.

Nanostructured layers were fabricated on the surface of 0.4C-1.0Cr and 1.0C-1.5Cr low alloy steels by using an ultrasonic particulate peening (USPP) technique. The microstructures and mechanical properties of the nanocrystallized layers were characterized by means of transmission electron microscopy, and nano-indentation test. Results showed that the average grain size in the surface nanocrystallized layer of 0.4C-1.0Cr and 1.0C-1.5Cr low alloy steel was about 5nm and 10nm, respectively. The nano-indentation hardnesses of the surface nanocrystallized layer were enhanced significantly and reach upwards of 8.0 GPa and 12.5 GPa, respectively.

It has economical and social value to build energy-saving architectures. Foamed concrete is commonly used as non-load bearing structure to save energy of buildings. With reinforcement of fiber foamed concrete can be used as load bearing structure to build architectures. The load bearing structure of fiber reinforced foamed has ability of self thermal insulation to get the aim of energy-saving. In the paper the excellence and disadvantage of foamed concrete is summarized. Methods are given to build the energy-saving architecture with self thermal insulation structure of fiber reinforced foamed concrete in new formwork. The building technology will be applied in new countryside construction in China.

A series of In2O3/Au nanorods (NRs) were fabricated and characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X–ray diffractometer (XRD) and X–ray photoelectron spectroscopy (XPS). The length to diameter ratios of In2O3/Au NRs was periodically modulated in the range of 2.9–4.5 through controlling the initial content of indium salt and reaction time. Their gas sensing properties to volatile organic compounds (VOCs) were carefully studied and then applied in exhaled breath detection. The results demonstrate that In2O3/Au NRs gas sensor can effectively detect acetone at 250 °C and ethanol at 400 °C. The corresponding actual detection limit is as low as 0.1 ppm to acetone and 0.05 ppm to ethanol, respectively. Moreover, by using humidity compensation method, In2O3/Au NRs gas sensor can clearly distinguish the acetone and ethanol biomarkers in human breath. The main reason of the enhanced gas sensing properties was attributed to the “spillover effects” between Au and In2O3 NRs. The excellent sensing performance indicates that In2O3/Au NRs is a promising functional material to actual application in monitoring and detecting diabetes and safe driving area in a noninvasive and more accurate way.

Segregation behavior of a φ406 mm Alloy 718 ingot was investigated and two-stage homogenization treatment was employed to relieve the micro-segregation between dendrite structures. In the first stage homogenization, the Laves phase elimination percentage was expressed dependence of two parameters (time and temperature). In order to characterize the effects of second stage homogenization, a 900 /1 h treatment was conducted after homogenization, which could form δ-phase (Nb-riched) to trace the diffusion of Nb. It was found that average composition of δ-phase area, quantity of δ-phase precipitation and size of δ-phase precipitation would change with the proceeding of homogenization. As a result, homogenous structure can be achieved by means of a two-stage homogenization treatment (1140 /60 h + 1190 /30 h).

Based on analysis of basic photonic Doppler velocimetry (PDV), a formula to measure velocity variation in a single cycle is put forward. PDV has been improved in three aspects, namely, the laser, the detector and the data processing. A measurement system for velocity of the initial stage of a shock motion has been demonstrated. Instantaneous velocity measurements have been performed. The experimental results have a good agreement with the values obtained from the accelerometer. Compared with the traditional fringe method, the proposed method in this paper can identify instantaneous velocity variation. So it is particularly suitable for measuring the velocity in the transient acceleration process of shock waves and detonation waves.

Alloy 718 has a very long history, it is still used extensively, which accounts for more than 50% of commercial superalloy productions in the world. The reason is that Alloy 718 exhibits good strength, excellent weldability and lastly, but most importantly, reasonable cost. Recently, confocal scanning laser microscope (CSLM) offers a convenient way for conducting a real-time and continuous in-situ observation of phase transformations at high temperatures. Several studies using CSLM have been reported for low carbon steel, stainless steel and metallic glass materials. The aim of this paper is to study the solidification behavior of Alloy 718 using confocal scanning laser microscope. In addition to the in-situ observation of solidification at different cooling rates, the analysis of microstructure evolution was conducted by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The results show that the cooling rate has a great impact on the solidification behavior of Alloy 718. Variation of secondary dendrite arm spacing, morphology change in MC carbide, and Laves phase after solidification at different cooling rates are studied in details. Introduction Alloy 718 is an age-hardenable wrought superalloy used for elevated temperature gas-turbine applications, which is famous for its excellent balance of properties and reasonable cost, accounting for more than 50% of commercial superalloy productions in the world [1]. With the development of land-based power generation and aircraft propulsion, scaling-up of components has become the necessity. In response to market demands the size of Alloy 718 ingot produced by VIM-ESR-VAR triple melting has increased markedly over the past 10 years [2-7]. However, the solutes segregation problem, mainly niobium segregation, is a big issue for producing large size Alloy 718 ingots. Particularly, some macrosegregations such as freckles and white spots formed during the solidification process may lead to failure of entire ingot. Therefore the indepth studies of solidification behavior of Alloy 718 are still needed.