Search

By employing the kernel functions with the form of piecewise polynomials in the Sobolev reproducing kernel Hilbert spaces (RKHSs), a globally superconvergent numerical technique is proposed to solve the second kind linear integral equations of Fredholm type. This method has an order of global convergence O ( h 4 ) and O ( h 6 ) based on the kernel functions in the Sobolev RKHSs H 1 and H 2 , respectively. Three linear Fredholm integral equations, one Volterra-Fredholm integral equation and one nonlinear Fredholm integral equation are numerically solved by the present approach to verify the superconvergence and effectiveness.

High atomic diffusivity in metals enables substantial tuneability of their structure and properties by tailoring the diffusional processes, but this causes their customized properties to be unstable at elevated temperatures. Eliminating diffusive interfaces by fabricating single crystals or heavily alloying helps to address this issue but does not inhibit atomic diffusion at high homologous temperatures. We discovered that the Schwarz crystal structure was effective at suppressing atomic diffusion in a supersaturated aluminum-magnesium alloy with extremely fine grains. By forming these stable structures, diffusion-controlled intermetallic precipitation from the nanosized grains and their coarsening were inhibited up to the equilibrium melting temperature, around which the apparent across-boundary diffusivity was reduced by about seven orders of magnitude. Developing advanced engineering alloys using the Schwarz crystal structure may lead to useful properties for high-temperature applications.

The spectrum effects on toroidal rotation braking, induced by n = 1 resonant magnetic perturbations (RMPs) in the discharges with q 95 = 4.1 and q 95 = 5.1 , are studied in the EAST tokamak. Here n is the toroidal mode number, RMP spectrum is varied by scanning δ ϕ U L , the phase difference between the upper and lower rows of RMP coils. The toroidal rotation changes periodically with the periodic δ ϕ U L scanning and such an effect is stronger in the discharge with lower q 95 = 4.1 . The spectrum dependence of the neoclassical toroidal viscosity (NTV) torque, modeled by NTVTOK based on the magnetic perturbation obtained from MARS-F calculation, agrees well with that of the experimentally observed braking torques in both discharges. The modeled NTV torque is stronger in the discharge with lower q 95, which also agrees with the observations. The comparisons between the spectrum dependence of the NTV and magnetic perturbations show that the resonant mode of magnetic perturbations near the plasma edge mainly contribute the NTV torque. These agreements between modeling and experiments highlight the capability of NTV theory in explaining the experimental observation in the EAST tokamak.

In this paper, the 3.5 vol.%TiB reinforced TC4 (Ti6Al4V) matrix composites were successfully fabricated using a mechanical ball milling and spark plasma sintering. The sintering temperature, sintering pressure and holding time were 700 °C~1100 °C, 40 MPa and 5 min, respectively. The 3.5 vol.% TiB/ TC4 matrix composites. The relative density of 3.5 vol.% TiB/TC4 composites increases with the increase of sintering temperature, and reaches saturation when the sintering temperature is 900 °C. The size of α-Lamellae increases from 1.47 μm to 2.44 μm with the increase of sintering temperature. The aspect ratio of TiB whiskers first increase and then decreases along with the solution time extending.

s Structural stability of nanograined (NG) metals at elevated temperatures or under mechanical loadings is much reduced relative to that of their coarse-grained counterparts, bottlenecking their processing and applications. In this paper, we present recent progress in stabilization of NG metals with grain boundary (GB) relaxation mediated by interactions of GBs and partial dislocations. Two strategies for inducing GB relaxation were identified in NG and submicro-grained pure metals: plastic deformation of nanograins below critical sizes and rapid heating for forming annealing twins. With the GB relaxation, both thermal stability and mechanical stability of nanograins in several pure metals are enhanced significantly.

In this paper, a novel strategy for lowering the coefficients of friction (COFs) of metals during dry sliding is introduced by producing a gradient nano-grained (GNG) surface layer without changing chemical compositions or phase constitution. Surface morphology variation, subsurface structural evolution and stress field analysis unfold that sliding-induced strain localization and microstructural instabilities are significantly mitigated through dislocation activity and grain boundary activities in the GNG surface layers. In addition, design guidelines for GNG materials with unprecedented low COFs are discussed based on interlinking tribological stress, surface deformation mechanisms and friction behavior.

The effect of Al stress on leaf pigment contents, chlorophyll (Chl) a fluorescence transient, and leaf gas exchange of Citrus sinensis and Citrus grandis were investigated in sandy culture with nutrient solution (control) or supplemented by 0.5 mM AlCl3.6H2O (Al toxic) for 54 weeks. We found a significant decline of Chl a, carotenoids (Car), Ch a/b, and Car/Chl (a+b) in C. grandis caused by Al stress. Except the significant increase of Car/Chl (a+b), no remarkable difference was found in C. sinensis. The Al-induced downregulation of CO2 assimilation was related to the imbalance of reduction and oxidation of primary quinone acceptor of PSII in two Citrus species. Compared to C. grandis, increasing ratio of Car/Chl (a+b) for photooxidation protection and decreasing inhibition of electron transfer contributed to electron conversion efficiency maintenance of PSII under Al stress in C. sinensis, a relatively Al-tolerant species.

Purpose Our purpose was to compare toxicity and biochemical control in postprostatectomy patients treated with conventional (66 Gy) or dose-intensified (72 Gy) radiation therapy. Methods and Materials Patients who had stage pT3-4, positive surgical margins, or rising prostate-specific antigen ≥ 0.2 ng/mL after radical prostatectomy were randomly assigned to receive either 66 Gy in 33 fractions or 72 Gy in 36 fractions. A primary endpoint was to assess the difference in biochemical progression-free survival (bPFS) between these 2 cohorts, and secondary endpoints were to assess differences in genitourinary (GU), gastrointestinal (GI), and hematologic toxicities between these 2 cohorts. bPFS was estimated by the Kaplan–Meier method and toxicities were compared using the χ2 test. Results Between September 2011 and November 2016, 144 patients were enrolled: 71 patients to the 66 Gy cohort and 73 patients to the 72 Gy cohort. The median follow-up time was 48.5 months (range, 14-79 months). There was no difference in 4-year bPFS between the 66 Gy and 72 Gy cohorts (75.9% vs 82.6%; P = .299). However, in patients with a higher Gleason score (8-10), the 72 Gy cohort had statistically significant improvement in bPFS compared with the 66 Gy cohort (79.7% vs 55.7%; P = .049). Toxicity analysis showed no difference in ≥2 acute or late GI or GU toxicities between these 2 cohorts. A total of 48 patients were scored as urinary incontinence before radiation therapy, of which 39 (81.3%) reported incontinence recovery or stable at 1-year follow-up, and only 9 (18.8%) patients reported worsening. There was no difference between the 2 cohorts in urinary incontinence either at baseline or at 1-year follow-up. Conclusions Dose escalation (72 Gy) demonstrated no improvement in 4-year bPFS compared with the 66 Gy regimen. However, the dose escalation was not associated with greater acute or late GU or GI toxicities and did not increase urinary incontinence.

Steinernema populi n. sp. was recovered by baiting from beneath poplar trees in China. Morphological and molecular features provided evidence for placing the new species into the Kushidai clade. The new species is characterized by the following morphological features: third-stage infective juveniles (IJ) with a body length of 1095 (973–1172) μm, a distance from the anterior end to excretory pore of 77 (70–86) μm and a tail length of 64 (55–72) μm. The Body length/Tail length (c) ratio and Anterior end to Excretory pore/ Tail length × 100 (E%) of S. populi n. sp. are substantially greater than those of all other ‘Feltiae–Kushidai–Monticolum’ group members. The first-generation males can be recognized by a spicule length of 66 (57–77) μm and a gubernaculum length of 46 (38–60) μm. The new species is further characterized by sequences of the internal transcribed spacer and partial 28S regions of the ribosomal DNA. Phylogenetic analyses show that Steinernema akhursti and Steinernema kushidai are the closest relatives to S. populi n. sp.

We hypothesised that adding a combination of fibrolytic and amylolytic enzymes to the diet of early-lactation dairy cows would improve rumen enzyme activity and bacterial diversity, promote energy metabolism, and benefit milk production in cows. Twenty multiparous early-lactation (90 ± 5 d) Holstein cows with similar body conditions were randomly allocated to control (CON, n = 10) and experimental (EXP, n = 10) groups in a completely randomised single-factor design. The CON was fed only a basal total mixed ration diet, and the diet of the EXP was supplemented with a combination of fibrolytic and amylolytic enzymes at 70 g/cow/d (cellulase 3 500 CU/g, xylanase 2 000 XU/g, β-glucanase 17 500 GU/g, and amylase 37 000 AU/g). The experiment lasted 28 days, with 21 days for adaptation and 7 days for sampling. Enzyme addition increased the activity levels of α-amylase and xylanase, and the ammonia-N concentration (P < 0.05) tended to increase the activity of β-glucanase (P = 0.08) in rumen fluid. However, there was no significant difference in the rumen bacterial richness and diversity, phylum (richness > 0.1%) or genus (richness > 1%) composition between the CON and EXP groups (P > 0.05). A tendency of difference was found between CON and EXP (R = 0.22, P = 0.098) in principal component analysis. Ten genera showed different abundances across the CON and EXP groups (linear discriminant analysis effect size, linear discriminant analysis > 2). EXP increased the ratio of albumin to globulin and the concentrations of total cholesterol and low-density lipoprotein cholesterol (P < 0.05) and tended to increase triglycerides (P = 0.09) in blood. Milk yield, 3.5% fat-corrected milk yield and energy-corrected milk yield increased with enzyme supplementation (P < 0.05). The production levels of milk fat and lactose increased, but the percentage of solids, not fat and protein, decreased in EXP (P < 0.05). Although the DM intake was not affected, the feed efficiency tended to increase (P = 0.07) in EXP. In conclusion, dietary supplementation with a mixture of fibrolytic and amylolytic enzymes on multiparous early-lactation dairy cows increased α-amylase and xylanase activity levels in rumen fluid, enhanced milk performance and tended to improve the feed efficiency in cows.

A four-row APPLE-Knot undulator is under developing in the High Energy Photon Source to get polarization adjustable synchrotron radiation and reduce on-axis heat load, because of the exotic magnetic field design, its construction faces challenges in mechanical design of frame, magnet blocks holder and integral field shimming method. In this paper, a mechanical design for APPLE-Knot undulator has been posed and structural deformation has been analysed, a test piece has been manufactured to test the physical design as well as magnetic holder design, integral field shimming method has also been described and realized, the result presents a good repeatability. It's a practical design of four-row APPLE-Knot undulator for the High Energy Photon Source.

Using molecular dynamics simulations, the melting behavior of disordered aluminum clusters with 30 ∼ 100 atoms has been systematically studied. We find that, all the disordered clusters undergo a glass transition before completely melting. We identify two characteristic temperatures, i.e. T s and T g (the glass transition temperature). When the temperature is higher than T s , the cluster shape starts to change, accordingly the configurational entropy emerges. For temperatures between T s and T g , the disordered clusters show a remarkable cooperative diffusion, more importantly, the activation energy of cooperative diffusions below T g is always lower than that of the liquid state. We have tried to understand such behavior from potential landscape and configurational entropies.

Nickel has a stable face-centered-cube lattice structure with a high stacking fault energy. No phase transition has been identified in Ni at elevated temperatures and under high pressure up to 200 GPa. In this study, we discovered formation of hexagonal-close-packed Ni nano-grains induced by plastic deformation. In cryogenic deformation of Ni nano-grains below a critical size of 17 nm when both dislocation activities and grain boundary processes are suppressed, an FCC-to-HCP transformation is triggered forming a mixture of FCC and HCP nano-grains. The finding offers a novel approach to tailor lattice structures of metals that are stable in coarse-grained form.

Purpose: The aim of the study was to evaluate the feasibility and toxicity of intra-rectal epinephrine during prostatic radiotherapy. Materials and methods: A total of 34 patients with prostate cancer were randomized to receive daily intra-rectal epinephrine (4 mg in 40 mL, n=16) or placebo (40 mL normal saline, n=18) 5 min before daily radiotherapy. Physical examination including systolic blood pressure (SBP) and heart rate (HR) was performed before, 5 min after, and 20 min after intra-rectal use. Toxicities were graded using the Radiation Therapy Oncology Group standard. A two-sided Fisher's exact test was used to compare proportions between groups. A mixed-effects model was used to analyze multiple measurements of SBP and HR. Survival curves were calculated using the Kaplan-Meier method and compared between groups using the log-rank test. Results: All patients completed the protocol treatment and reported no cardiovascular symptoms after intra-rectal administration. There were no differences in SBP and HR between these two groups at any time point (before, 5 min after, and 20 min after epinephrine). At 5 weeks after the start of radiotherapy, the incidence of rectal toxicity≥grade 2 was 27.8% (5/18) for the control group versus 12.5% (2/16) for the epinephrine group, but was not statistically significant (p=0.4). There was no rectal toxicity≥grade 2 in these two groups beyond 2-year follow-up. The 5-year biochemical relapse-free survival was 75.0% and 72.2% for the epinephrine and control group, respectively. Conclusion: Results of this pilot randomized trial have demonstrated that intra-rectal administration of epinephrine is feasible and safe in prostatic radiotherapy. Its radio-protective effect warrants further investigation.

A sensor was fabricated based on optical gas sensing, the sensitivity of tin oxide to methane via surface adsorption and electromagnetic theory. A 62.5/125 μm standard multimode fibre (MMF) and a 9/125 μm standard single-mode fibre (SMF) were spliced to fabricate a core diameter mismatch-based optical fibre methane sensor with an MM-SM-MM structure. The exposed fibre core areas were coated with graphene-doped tin oxide such that a novel graphene-based optical fibre methane sensor was fabricated. The experimental results show that the sensor exhibited a better linear fitting for greater reproducibility in the detection of low concentrations of methane than did the D-type gas sensor reported previously by the same authors.

The electrical performances and relaxation behaviors of the Na0.525Bi0.475TiO2.975 and Bi-deficient Na0.51Bi0.48TiO2.975 sample were investigated. The grain conductivity of the Na0.525Bi0.475TiO2.975 sample is able to reach 1.51 × 10−3 S/cm at 673 K. In the temperature range of measurement, the grain conductivity of the Bi-deficient Na0.51Bi0.48TiO2.975 sample is lower than that of the Na0.525Bi0.475TiO2.975 sample. By the internal friction and dielectric relaxation spectrum, the activation energy and relaxation time at infinite temperature were determined as (0.82 eV, 2.47 × 10−14 s), (0.67 eV, 5.82 × 10−12 s) and (0.85 eV, 5.8 × 10−13 s), (0.52 eV, 2.55 × 10−10 s) for the Na0.525Bi0.475TiO2.975 and Na0.51Bi0.48TiO2.975 samples at the different temperature regions. In the Na0.525Bi0.475TiO2.975 compound, there is larger specific free volume, higher mobile oxygen vacancy content and better oxygen vacancy mobility, which cause the higher grain conductivity in the Na0.525Bi0.475TiO2.975 compound. To some extent, by the Bi-deficient method, oxygen vacancies can be introduced into the Na0.51Bi0.48TiO2.975 compound and the grain conductivity may be improved, but the other side of Bi-deficiency harms the oxygen vacancy diffusion capacities in the Na0.5Bi0.5TiO3 compound.

A multi-degree of freedom mechanistic-chemometrics model for predicting the pitting damage of HP-13Cr stainless steel is developed by combining the mechanistic models and chemometrics method. The mechanistic model is reconstructed by considering the effect of single factors, such as high temperature, high CO2 pressure, flow rates and complex stress distribution. The single mechanistic models are combined together considering the weight coefficients of variable interaction using the chemometrics method. Finally, the predicted results are validated by six-year-served field data, which indicates that the newly developed mechanistic-chemometrics model is accurate and highly reliable.

Summary Amplitude versus offset/angle (AVO/AVA) inversion recovers elastic properties of subsurface media and thus is an essential tool in oil and gas exploration. The exact Zoeppritz equation has high accuracy in reflection coefficient modelling, but the amplitude inversion based on the exact Zoeppritz equation is highly nonlinear. In this abstract, we propose a hybrid quantum genetic algorithm (HQGA) for the nonlinear AVO inversion using the exact Zoeppritz equation. Compared with the conventional genetic algorithm (GA) and quantum genetic algorithm (QGA), HQGA includes a self-adaptive rotating strategy, quantum mutation, and quantum catastrophe. The self-adaptive rotating strategy improves the flexibility and efficiency of a quantum revolving gate, and quantum mutation and quantum catastrophe enhance the local and global search capabilities respectively. Numerical tests show that compared with GA and QGA, HQGA requires fewer searches to converge to a global optimal solution, and the inversion results of HQGA have higher accuracy, higher efficiency and greater robustness than that of GA and QGA. A field data application verifies that there is a good consistency between the inverted parameters and real logs.

Summary The Lower Silurian shale-gas formation in the Sichuan Basin shows a property of transverse isotropy with vertical axis of symmetry (VTI). We present a case study of seismic inversion and quantitative interpretation of the target shale-gas reservoir formation. An AVO inversion method for VTI media is applied to estimate three elastic parameters (the acoustic impedance - A, the shear modulus weighted by an anelliptical anisotropy parameter - B, and the approximated horizontal P-wave velocity - C). Statistical rock-physics and machine learning are applied to the inverted parameters for the characterization of the reservoir formation. Brittleness-related shales can be successfully discriminated from surrounding formations using the attribute pair A-C, and the organic-rich gas-bearing shale can be successfully identified using the attribute pair A-B. Estimated TOC results using statistical rock-physics and support vector regression (SVR) method show highly consistent with the each other. Comparison between the prediction results and well logs demonstrates the feasibility of the inversion and quantitative interpretation approaches.

AIMS The effect of increasing dietary cation-anion difference (DCAD) on rumen fermentation and ruminal microbial community in dairy cows under heat stress (HS) conditions were evaluated. METHODS AND RESULTS This study was performed as a two-period cross-over design during the summer season, with eight lactating dairy cows randomly distributed to either a control DCAD diet (CON: 33·5 mEq/100 g DM) or high DCAD diet (HDCAD: 50·8 mEq/100 g DM). Throughout the present study, the temperature and humidity index (THI; 80·2 ± 4·29) was generally elevated above the threshold (THI = 72) that is reported to cause HS in lactating dairy cows. Rumen liquid samples were collected on 15 and 21 d during each 21 d-period. The absolute concentration of ruminal total volatile fatty acid (TVFA) in HDCAD treatment was significantly (P

The 19F(p, αγ)16O reaction is of crucial importance for Galactic 19F abundances and CNO cycle loss in first generation Population III stars. Due to its extremely small cross sections, the 19F(p, αγ)16O reaction has not been measured in the low energy part of the Gamow window(70-200 keV). As a day-one campaign, the experiment was performed under the extremely low cosmicray-induced background environment of the China JinPing Underground Laboratory(CJPL), one of the deepest underground laboratories in the world. The γ-ray yields were measured over Ec.m. =72.4–344 keV, covering the full Gamow window for the first time. The direct experimental data will help people to expound the fluorine over-abundances, energy generation, as well as heavy-element nuclosynthesis scenario in asymptotic giant branch (AGB) stars, with the astrophysical model on the firm ground.