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• The synergistic effects of multiple deformation mechanisms and solid solution strengthening on the mechanical properties of Mo-reinforced CoCrNi medium-entropy alloys (MEAs) were revealed via first principles calculations. • The essential criterion was proposed for the composition design of strong and ductile FCC (CoCrNi) 100- x Mo x MEAs based on the synergy of multiple deformation mechanisms and intense solid solution strengthening. • The optimal composition of FCC (CoCrNi) 100- x Mo x MEAs was predicted as (CoCrNi) 93 Mo 7 according to the essential criterion and the results of first principles calculations. • The accuracy of essential criterion was validated by the comparison with previous experimental data. The assistance of alloying elements provides enormous opportunities for the discovery of high-performance face-centered cubic (FCC) medium-entropy alloys (MEAs). In this work, the influence of alloying element Mo on the phase stability, stacking fault energy (SFE), deformation mechanisms, lattice distortion, and mechanical properties of (CoCrNi) 100– x Mo x (0 ≤ x ≤ 10) MEAs was synthetically explored with the first-principles calculations. It indicates that the FCC phase remains metastable at 0 K, and its stability degenerates with increasing Mo content. The monotonous decrease of SFE is revealed with the rise of Mo content, which promotes the activation of stacking faults, deformation twinning, or martensitic transformation. Raising Mo content also causes the aggravation of lattice distortion and thus triggers intense solid solution strengthening. Significantly, the essential criterion for the composition design of FCC (CoCrNi) 100– x Mo MEAs with superior strength-ductility combination was established based on the synergistic effects between multiple deformation mechanisms and solid solution strengthening. According to the criterion, the optimal composition is predetermined as (CoCrNi) 93 Mo 7 MEA. The criterion is proved to be effective, and it can provide valuable inspiration for the development of alloying-element reinforced FCC multi-principal element alloys. [Display omitted] [ABSTRACT FROM AUTHOR]

Laminated templates electro-deposition is an original manufacturing technology that is aimed at micro-scale metallic structures fabrication. Based on the discrete piling-up principal and electrodepositing method, it realizes a manufacturing simplification from the traditional machining to the repetition of template-assisted planar deposition in forming a three-dimensional complicated object. The ability to control the deposit surface nouniformity is a key to successful implementation for each planar depositing. Profile geometry and current configuration are alternated in experiment and thought as the major factors influencing deposit surface roughening. The results show that the surface of the deposits obtained by pulse electroforming has better performance in deposit thickness distribution and properties of the deposits. Optimized parameters have been obtained from the preliminary experiments in which 0.3millimeters-thick epoxy templates and 4~6A/dm2 current density were used at 40+ and a bulk of copper parts, section size 30mm×30mm and 7mm thick were produced and tested for their mechanical performance.

Reconstituted nanostructured partially stabilized zirconia (PSZ) feedstock powders were laser sintered under a range of laser processing parameters. Scanning electron microscopy (SEM) was applied to analyze the microstructure of the powders and sintered bulk. Microhardness of the samples was also tested by Vickers Microhardness tester. These results demonstrated that the microstructure of the samples exhibits a bimodal distribution which comprises molten and non-molten feedstock particles. It was found that feedstock maintained some of its nanostructure during laser sintering with relatively low laser power; whereas feedstock lost most of its initial characters with high laser power. It was also observed that Microhardness values have respect to the proportion of non-molten feedstock in those samples.

Nanostructured ceramic bulk materials were achieved from nano-Al2O3 ceramic powders via direct selective laser sintering (SLS). SLS as a non-traditional machining technology of Rapid Prototyping was introduced and compared with other ceramic forming technologies. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were applied to analyze the microstructure of the ceramic bulk materials. These results demonstrated that the nano-Al2O3 ceramic powders can be sintered into bulk materials maintained nanostructure with some technological parameters. It was found that the nanostructured ceramic bulk exhibited unique microstructure and was free formed rapidly by this sintering technology.

In the field of experimental mechanics, there exist some circumstances when only data at the boundary can be obtained while the internal data are unavailable, or when some data are missed due to shadow, illumination saturation and other reasons. Thus it would be helpful if a reasonable estimation of the unavailable or missed data can be obtained. In this study, an algorithm is developed to reconstruct the missed data from the existing ones by generating a series of equations about the missed data and solving for an optimal solution using least-squares approach. Results based on both simulation data and real incomplete experimental data obtained by shearography and fringe projection show the usefulness and potential of the algorithm for experimental mechanics applications.

A series of all-perovskite oxide p-n heterojunctions (PNHs) as well as perovskite oxide and Si PNHs have been fabricated by a laser molecular-beam epitaxy. The good nonlinear and rectifying I-V characteristics in the PNHs, unusual and high sensitivity of positive magnetoresistance in low magnetic field in SrNbxTi1-xO3/La1-ySryMnO3 and La1-xSrxMnO3/Si PNHs, ps orders ultrafast photoelectric effect in La1-xSrxMnO3/Si PNHs, as well as ferroelectric property due to the interface enhancement in BaNb0.3Ti0.7O3/Si PNHs have been observed. It is expected that the further investigation on the PNHs could not only stimulate theoretical study on the mechanisms but also would open up new possibilities in the development and application of electrical devices.

A series of all-perovskite oxide p-n heterojunctions (PNHs) as well as perovskite oxide and Si PNHs have been fabricated by a laser molecular-beam epitaxy. The good nonlinear and rectifying I-V characteristics in the PNHs, unusual and high sensitivity of positive magnetoresistance in low magnetic field in SrNbxTi1-xO3/La1-ySryMnO3 and La1-xSrxMnO3/Si PNHs, ps orders ultrafast photoelectric effect in La1-xSrxMnO3/Si PNHs, as well as ferroelectric property due to the interface enhancement in BaNb0.3Ti0.7O3/Si PNHs have been observed. It is expected that the further investigation on the PNHs could not only stimulate theoretical study on the mechanisms but also would open up new possibilities in the development and application of electrical devices.

ABSTRACTThe Segmented-Plume Primary Aerosol Model (SPPAM) has been developed over the past several years. The earlier model development goals were simply to generalize the widely used Industrial Source Complex Short-Term (ISCST) model to simulate plume transport and dispersion under light wind conditions and to handle a large number of roadway or line sources. The goals have been expanded to include development of improved algorithm for effective plume transport velocity, more accurate and efficient line and area source dispersion algorithms, and recently, a more realistic and computationally efficient algorithm for plume depletion due to particle dry deposition. A performance evaluation of the SPPAM has been carried out using the 1983 PNL dual tracer experimental data. The results show the model predictions to be in good agreement with observations in both plume advection-dispersion and particulate matter (PM) depletion by dry deposition. For PM2.5impact analysis, the SPPAM has been applied to the Rubidoux area of California. Emission sources included in the modeling analysis are: paved road dust, diesel vehicular exhaust, gasoline vehicular exhaust, and tire wear particles from a large number of roadways in Rubidoux and surrounding areas. For the selected modeling periods, the predicted primary PM2.5to primary PM10 concentration ratios for the Rubidoux sampling station are in the range of 0.39–0.46. The organic fractions of the primary PM2.5impacts are estimated to be at least 34–41%. Detailed modeling results indicate that the relatively high organic fractions are primarily due to the proximity of heavily traveled roadways north of the sampling station. The predictions are influenced by a number of factors; principal among them are the receptor locations relative to major roadways, the volume and composition of traffic on these roadways, and the prevailing meteorological conditions.

This paper makes some systematic studies of the origination, the physical-mathematical characteristics and the disturbing function of the pressure wave in the inter-electrode gap, especially of the influence on the copying accuracy in PECM. Through the observation of high speed photograph to the real process in the gap and the analysis of precise measuring data for the pressure wave, we have recognized perceptually about the three respects.

Purpose: We investigated the pathophysiology of structurally based corporeal veno-occlusive dysfunction. Materials and Methods: We prospectively evaluated 24 impotent patients (mean age plus or minus standard error 46 plus/minus 3 years) who had exposure to vascular risk factors and/or disorders inducing diffuse trabecular structure alterations and who underwent penile prosthesis insertion. Preoperative indexes of veno-occlusive function (flow to maintain, venous outflow resistance and pressure decay measurements using repeat dosing pharmacocavernosometry) were correlated with postoperative erectile tissue computer assisted color histomorphometry (percent trabecular smooth muscle to total erectile tissue area). To develop further study findings and correlate histomorphometric findings with molecular biological properties molecular biological studies (ribonuclease protection analysis, reverse transcription-polymerase chain reaction assay for expression of transforming growth factor-beta 1 messenger [m] ribonucleic acid [RNA] and protein affinity labeling techniques for specific transforming growth factor-beta receptors) were performed in representative patients with high (39 to 43 percent), intermediate (30 to 37 percent) and low (13 to 29 percent) trabecular smooth muscle content (normal 42 to 50 percent). Results: Flow to maintain, venous outflow resistance and pressure decay values significantly correlated with trabecular smooth muscle cell content (r = -0.89, 0.82 and -0.85, respectively). In the high, intermediate and low smooth muscle content subgroups flow to maintain, venous outflow resistance and pressure decay values were 1 to 5, 9 to 30 and 50 to 120 ml. per minute, 17 to 84, 3 to 9 and 1 to 2 mm. Hg/ml. per minute, and 40 to 60, 48 to 80 and 110 to 120 mm. Hg decrease in 30 seconds from 150 mm. Hg, respectively. There were no significant differences in patient age or prevalence of risk factors among the 3 subgroups. Patients representative of all 3 subgroups had transforming growth factor-beta 1 mRNA, auto-induction of transforming growth factor-beta 1 mRNA and induction and/or increased availability of all 3 types of transforming growth factor-beta receptors. Conclusions: The pathophysiology of structurally based corporeal veno-occlusive dysfunction is related to elevated corporeal connective tissue content. Based on our data and those in the literature corporeal fibrosis is hypothesized to develop secondary to abnormalities in the regulation of normal collagen synthesis and degradation, most likely associated with adverse influences of chronic ischemia.