Search

Nickel‐titanium alloys are produced via laser metal deposition using titanium carbide and titanium diboride as nucleating agents to refine the grain structure. The optimal process parameters are determined by analyzing the quality of the alloy formation. X‐ray diffraction confirms the simultaneous presence of the B19′ martensitic phase and B2 austenitic phase in the nickel‐titanium alloy fabricated by laser metal deposition. Tensile testing is performed on the samples at room temperature. The results show that adding mass fractions 0.9 % titanium carbide and titanium diboride effectively refines the grain size of the nickel‐titanium alloy fabricated by laser metal deposition, leading to improved tensile properties. Specifically, the addition increases the tensile strength by 40 % and 70 %, and the elongation by 50 % and 60 %. [ABSTRACT FROM AUTHOR]

This article explores the relationship between stall types and speed ratios in contra-rotating boost stages, discovering stationary circumferential stall cells and dual stall cell phenomena, and examines the relationship between stall characteristics and inlet distortions. These stall characteristics of counter-rotating boost stages are markedly different from the single stall patterns of traditional compressor rotor-stator structures, highlighting the complexity of the flow field in counter-rotating stages. The study uses the experimental methods to investigate different speed ratios under both uniform and distorted inlet conditions, conducting both accelerating and decelerating stall tests, with each stall condition analyzed using data from 25 s. The main focus is on the stall types, frequencies, and development patterns under different distortion conditions at various speed ratios, filling a research gap in counter-rotating boost stages. It explores the unstable flow characteristics of counter-rotating boost stages under distorted conditions, particularly the stall disturbance characteristics and pressure fluctuation patterns at the blade tip during stall entry and recovery under distortions. Comparing distortions with uniform inlet conditions provides an intuitive understanding of the influence of various types of distortions on wall pressure and stall in the flow field. Researchers can use this knowledge to design casings or blowing devices to suppress stall disturbances, thereby achieving stall prevention and enhancing stability. [ABSTRACT FROM AUTHOR]

A high sensitivity reactor was developed to study slow reactions, such as ammonia synthesis over low surface area model catalysts at 1 bar and up to 550 °C. The reactor is connected to an ultra-high vacuum system with a transferable sample design, which allows for cleaning, preparation, and spectroscopic characterization of samples before and after the reaction without exposure to any contaminated environment, such as air. A quasi-closed small volume (250 µl) quartz glass reaction cell is integrated through a capillary with a quartz glass sniffer tube connected to a mass spectrometer. The capillary reduces the 1 bar pressure in the cell to 10−7 mbar in the sniffer tube and mass spectrometer chamber. A quartz fiber-guided laser is used to heat up the sample, and the temperature can be regulated by the proportional–integral–derivative controlled laser power output for fast reaction kinetics research. Proof of principle ammonia synthesis experiments in this reactor at 1 bar, 350–500 °C on Fe(111) single crystal and mass-selected Ru clusters supported on CeO2 thin film yield kinetic parameters that agree very well to those reported in the literature. [ABSTRACT FROM AUTHOR]

The expressway service area's short-term traffic flow forecast is helpful for adjusting expressway traffic and formulating time-sensitive traffic flow adjustment strategies. To solve the problems of strong stochastic fluctuation of traffic flow, insufficient degree of traffic flow data mining and low prediction accuracy in common deep learning prediction models, a hybrid model combining ensemble empirical mode decomposition and bidirectional gated recurrent unit (EEMD+BI_GRU) is proposed for expressway intelligent service area traffic flow prediction. The model decomposes the traffic time series using the EEMD algorithm, with the aim of reducing the non-stationarity of the initial traffic series and providing a potential feature set for prediction. The BI_GRU structure as a prediction model enables the model to process traffic data more deeply and efficiently to improve prediction accuracy. Based on the real traffic flow data of Taishi service area in Gansu Province, several reference models were developed and analyzed in comparison with the suggested model. The results demonstrate that, as compared to traditional mainstream models, the method of applying signal decomposition technique-provided sequences as input characteristics may significantly enhance prediction accuracy. [ABSTRACT FROM AUTHOR]

The petrophysical properties of 41 volcanic samples from La Soufrière volcanoe (Guadeloupe Island, Eastern Caribbean, France) are investigated. We first measure the complex conductivity spectra of these rock samples at 4 salinities (NaCl) at laboratory conditions (∼20 °C). For each rock sample, we determine the (intrinsic) formation factor, the surface conductivity and the Cole–Cole normalized chargeability. We also measure the compressional wave velocity (dry and saturated), the shear wave velocity in saturated conditions, the (dry and saturated) thermal conductivity, the dry specific heat capacity and the permeability of the rock samples as well as their cation exchange capacity (CEC) and connected porosity. The formation factor versus porosity obeys Archie's law with a cementation exponent of 2.16 ± 0.10. The surface conductivity and the normalized chargeability are proportional to each other and to the CEC divided by the tortuosity of the material (product of the formation factor by the connected porosity) as predicted by the dynamic Stern layer model. Permeability can be predicted from the normalized chargeability and the formation factor inside one order of magnitude. The thermal conductivity and the seismic properties can be evaluated from the connected porosity of the core samples formation factors. A non-linear relationship is established between the shear wave velocity and the compressional wave velocity for the present data set and other data from the literature. Finally, we show on a specific example, how to convert an induced polarization survey on a stratovolcano into a seismic velocity model (P - and S -waves velocity distributions). We perform a specific application to Papandayan Volcano, a stratovolcano located in Java Island (Indonesia). This work paves the way to the joint inversion problem of seismic and induced polarization surveys for volcanic unrest monitoring. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is suggested to be implicated in the development of cardiometabolic diseases. We conducted a Mendelian randomization (MR) study to assess potential causality for associations of RA with the risk of cardiometabolic diseases, including type 2 diabetes (T2D), coronary artery disease (CAD), and ischaemic stroke. Seventy independent single-nucleotide polymorphisms (SNPs) associated with RA were identified as instrumental variables from a genome-wide association study (GWAS) of 58 284 European subjects. Summary-level data for the associations of the 70 genetic variants with T2D, CAD, and ischaemic stroke were taken from three GWASs with a total of 1 529 131 participants. Inverse-variance weighted (IVW) MR was used in the main analyses. The main IVW MR analysis showed that genetically determined RA was associated with higher risks of T2D [odds ratio (OR): 1.04, 95% confidence interval (CI) 1.02–1.05; p < 0.001] and CAD (OR: 1.02, 95% CI 1.00–1.03; p = 0.012), but not ischaemic stroke (OR: 1.00, 95% CI 0.99–1.02; p = 0.961). Sensitivity analyses with multiple MR methods confirmed these associations. MR-Egger regression showed no evidence of pleiotropy in the association between genetically determined RA and the risk of T2D, CAD, and ischaemic stroke. Leave-one-out sensitivity analysis showed that the association between genetically determined RA and the risk of T2D, CAD, and ischaemic stroke was not driven by any individual SNP. Genetically determined RA was associated with increased risks of T2D and CAD, suggesting that RA plays a crucial role in the pathogenesis of T2D and CAD. [ABSTRACT FROM AUTHOR]

1. The extracellular matrix (ECM) constitutes the basal lamina and the area between follicular cells. Remodelling the ECM is believed to be a key event in follicular development, especially during selection, and plays an important role in cell migration, survival, and steroidogenesis. miR-199-3p is differentially expressed in the goose granulosa layer during follicular selection and is reported to play a primary role in inhibiting cell migration and invasion. Nevertheless, the effect of miR-199-3p on ovarian follicles and its role in follicular cellular migration is not understood. 2. In this study, qRT-PCR assays revealed that miR-199-3p was differentially expressed in the granulosa layer from goose ovarian follicles before and after follicular selection. Additionally, miR-199-3p overexpression in cultured granulosa cells (GCs) from goose pre-hierarchical follicles significantly suppressed cell viability and migration. It elevated the concentration of progesterone and the expression of key progesterone production genes. Furthermore, miR-199-3p overexpression in the GCs of goose pre-hierarchical follicles inhibited the expression of ECM-related genes (ITGB8, MMP9 and MMP15) yet promoted the expression of another two ECM-related genes (COL4A1 and LAMA1). Finally, dual-fluorescence reporter experiments on 293T cells established the direct targeting of ECM gene ITGB8 by miR-199-3p. 3. In conclusion, miR-199-3p may participate in granulosa cell migration, viability, and steroidogenesis in goose ovarian follicles before selection by modulating ITGB8 and other ECM-related genes. [ABSTRACT FROM AUTHOR]

This paper provides a method to predict the long-term creep behavior of continuous glass fiber-reinforced polypropylene composites (CGFRPP). The finite element method was used in this study, which was based on short-term experiments. For these calculations, a viscoelastic constitutive equation named the Burgers model was introduced to describe the creep behavior of pure polypropylene (PP) resin. The suitability of the Burgers model for the PP resin was investigated by performing short-term creep experiments under various stress conditions. The stress-dependent Burgers model was, thereafter, proposed by the calibration of elastic stiffness and viscosity parameters in nonlinearity. This nonlinear model was finally incorporated into a representative volume elements (RVE) model to predict the long-term creep behavior of CGFRPP unidirectional (UD) tape. It was found that the simulation results agreed with experiments when using the nonlinear Burgers model. The creep mechanism of the UD tape was also analyzed microscopically with the RVE model, and the redistribution of stress in the fiber and matrix was discussed. [ABSTRACT FROM AUTHOR]

Eco-friendly and low-temperature liquid hydrogen has been used as propellants for the launching of rockets. As the low-temperature two-phase gas-liquid flow differs from room-temperature flows, studying the motion of bubbles in the liquid hydrogen fluid is of great importance. By using the volume of the fluid model on the Fluent software, we perform two-dimensional numerical modeling of single Taylor bubble rising movement and double Taylor bubbles coalescence in stagnant liquid hydrogen fluids in vertical and inclined pipe. The results are as follows: for a single Taylor bubble rising in a vertical and inclined pipe, the main hydrodynamic characteristics in the nose area, the liquid film area and the wake region of bubble are determined with the pipe diameter and the inclination angle. Secondly, for double Taylor bubbles rising in a pipe of different inclination angles, the velocity, length and shape of the leading bubble change little, but the velocity and length of the trailing bubbles reduce initially, then increase and reduce again as the separation distance becomes smaller. The research results are helpful to the study of slug flow patterns in cryogenic two-phase flow, and lay a theoretical foundation for the safe transportation of liquid hydrogen propellant in cryogenic pipelines. [ABSTRACT FROM AUTHOR]

As a classic theranostic radiopharmaceutical, radioiodine (131I) has been utilized in the management of differentiated thyroid cancer (DTC) for more than 8 decades, and the refinement of its clinical practice has been raised recently. This study was conducted to evaluate the efficiency of a diagnostic (Dx) 131I scan in optimizing the indication of initial radioiodine oncolytic treatment (ROT) for metastatic DTC by predicting therapeutic outcomes. A total of 100 patients (Dx positive, n=29; Dx negative, n=71) were eligible for patient-based analysis. The matching rate was 83.0% between the Dx and the post-therapeutic scans (kappa = 0.648, P <0.001). The biochemical remission rate and structural shrinkage rate induced by the initial ROT in the Dx-positive group were, respectively, greater than those in the Dx-negative group (83.3% vs. 17.4%, P <0.001; 37.9% vs. 4.2%, P <0.001). Notably, the predictive values of positive Dx scans for ROT responsiveness and negative Dx scans for ROT nonresponsiveness reached up to 89.7% and 84.5%, respectively. This Dx scan approach seems viable in characterizing the 131I-avidity of metastatic DTC and plays a pivotal role in optimizing the indication of initial ROT for metastatic DTC. • Dx scan using 74 MBq of 131I is feasible without stunning effect. • Dx scan strongly agrees with the Rx scan in assessing the 131I-avidity of metastatic DTC. • Dx scan optimizes the indication of initial ROT by predicting therapeutic outcomes. [ABSTRACT FROM AUTHOR]

Fe–Mn–Si–Cr–Ni shape memory alloys (SMAs) are unique low-cost materials with shape memory properties that grant them the ability to be used in both functional and structural applications. Such SMAs are especially sought in the construction sector for the creation of new components and/or the reinforcement of damaged ones. In this study, a Fe–17Mn–5Si–10Cr–4Ni–1(V, C) wt% SMA was gas tungsten arc welded, with the objective to investigate the microstructure and mechanical performance changes occurring after welding. A comprehensive assessment of processing, microstructure and properties relationships was established combining microscopy (optical and electron), synchrotron X-ray diffraction, microhardness mapping and tensile testing including cycling assessment of the joint's functional performance. It is shown that the present SMA has good weldability, with the joints reaching nearly 883 MPa at fracture strain of 23.6 ± 2.1%. Alongside this, several microstructure differences were encountered between the as-received and as-welded condition, including the formation of ferrite and Fe5Ni3Si2 P213 cubic precipitates amidst the fusion zone in the latter region. [ABSTRACT FROM AUTHOR]

Wood smoke contains large quantities of carbonaceous aerosols known to increase climate forcing and be detrimental to human health. This paper reports the findings from our ambient sampling of fresh residential wood combustion (RWC) plumes in two heating seasons (2015–2016, 2016–2017) in Upstate New York. An Aethalometer (AE33) and a pDR-1500 were employed to monitor residential wood smoke plumes in Ithaca, NY through a hybrid mobile-stationary method. Fresh wood smoke plumes were captured and characterized at 13 different RWC sources in the city, all without significant influence from other combustion sources or atmospheric aging. Wood smoke absorption Ångström exponent (AAE) was estimated using both a one-component model, AAEWB, and a two-component model, AAEBrC (assuming AAEBC = 1.0). Consistent with the recent laboratory studies, our results show that AAEs were highly variable for residential wood smoke for the same source and across different sources, with AAEWB values ranging from 1.3 to 5.0 and AAEBrC values ranging from 2.2 to 7.4. This finding challenges the use of using a single AAE wood smoke value within the range of 1 to 2.5 for source apportionment studies. Furthermore, the PM2.5/BC ratio measured using optical instruments was demonstrated to be potentially useful to characterize burning conditions. Different wood smoke sources can be distinguished by their PM2.5/BC ratio, which range between 15 and 150. This shows promise as an in-situ, cost-effective, ambient sampling-based method to characterize wood burning conditions. Implications: There are two main implications from this paper. First, the large variability in wood smoke absorption Ångström exponent (AAE) values revealed from our real-world, ambient sampling of residential wood combustion plumes indicated that it is not appropriate to use a single AAE wood smoke value for source apportionment studies. Second, the PM2.5/BC ratio has been shown to serve as a promising in-situ, cost-effective, ambient sampling-based indicator to characterize wood burning conditions. This has the potential to greatly reduce the costs of insitu wood smoke surveillance. [ABSTRACT FROM AUTHOR]

We present an inexpensive device for non-thermal irreversible electroporation (IRE) manufactured by upgrading an industrial high-voltage pulse generator. In addition to the generator, the experimental hardware-and-software complex (IRE system) contains a microprocessor and a temperature sensor, which enables automatic control the pulse frequency in accordance with the temperature of the object. The IRE system was tested in in vitro and in vivo experiments: effective and safe non-thermal IRE was demonstrated. The developed system is easily reproducible and can be especially useful for demonstration experiments, pioneering research, as well as for teaching the basics of IRE. [ABSTRACT FROM AUTHOR]

Background: Stereotactic body radiotherapy (SBRT) is an established local treatment method for patients with hepatic oligometastasis or oligoprogression. Liver metastases often occur in close proximity to radiosensitive organs at risk (OARs). This limits the possibility to apply sufficiently high doses needed for optimal local control. Online MR-guided radiotherapy (oMRgRT) is expected to hold potential to improve hepatic SBRT by offering superior soft-tissue contrast for enhanced target identification as well as the benefit of gating and daily real-time adaptive treatment. The MAESTRO trial therefore aims to assess the potential advantages of adaptive, gated MR-guided SBRT compared to conventional SBRT at a standard linac using an ITV (internal target volume) approach.Methods: This trial is conducted as a prospective, randomized, three-armed phase II study in 82 patients with hepatic metastases (solid malignant tumor, 1-3 hepatic metastases confirmed by magnetic resonance imaging (MRI), maximum diameter of each metastasis ≤ 5 cm (in case of 3 metastases: sum of diameters ≤ 12 cm), age ≥ 18 years, Karnofsky Performance Score ≥ 60%). If a biologically effective dose (BED) ≥ 100 Gy (α/β = 10 Gy) is feasible based on ITV-based planning, patients will be randomized to either MRgRT or ITV-based SBRT. If a lesion cannot be treated with a BED ≥ 100 Gy, the patient will be treated with MRgRT at the highest possible dose. Primary endpoint is the non-inferiority of MRgRT at the MRIdian Linac® system compared to ITV-based SBRT regarding hepatobiliary and gastrointestinal toxicity CTCAE III or higher. Secondary outcomes investigated are local, locoregional (intrahepatic) and distant tumor control, progression-free survival, overall survival, possible increase of BED using MRgRT if the BED is limited with ITV-based SBRT, treatment-related toxicity, quality of life, dosimetric parameters of radiotherapy plans as well as morphological and functional changes in MRI. Potential prognostic biomarkers will also be evaluated.Discussion: MRgRT is known to be both highly cost- and labor-intensive. The MAESTRO trial aims to provide randomized, higher-level evidence for the dosimetric and possible consecutive clinical benefit of MR-guided, on-table adaptive and gated SBRT for dose escalation in critically located hepatic metastases adjacent to radiosensitive OARs.Trial Registration: The study has been prospectively registered on August 30th, 2021: Clinicaltrials.gov, "Magnetic Resonance-guided Adaptive Stereotactic Body Radiotherapy for Hepatic Metastases (MAESTRO)", NCT05027711. [ABSTRACT FROM AUTHOR]

• On the basis of Dehbi diffusion model, the UDF program for condensation of vapor containing non-condensable gases is prepared by using CFD program FLUENT. • Reproduced the condensation of vapor with non-condensable gas on the sloping wall in the confined environment of Xi'an Jiaotong University, and the numerical simulation is in good agreement with the experimental results. • The influence of wall inclination angle on the condensation characteristics of vapor with non-condensable gas in large confined space and condensation plane is analysed, and the influence of wall inclination angle on the condensation performance of vapor with non-condensable gas in containment is discussed. In the Westinghouse AP series steel containment vessel, the outer wall is cooled by spray and natural convection, while the internal vapor is allowed to condense on the inner wall. At this point, the containment dome becomes part of the condenser wall, and its curved structure can change the flow mode of the condensate water, thereby affecting the local condensation (heat exchange) capability of the wall. This article is based on the CFD program FLUENT and develops a UDF program suitable for the condensation of vapor with non-condensable gas. The influence of the wall tilt angle on the condensation characteristics of vapor with non-condensable gas is investigated and compared with experimental data from Xi'an Jiaotong University. The results show that the numerical simulation is in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Short-term prediction of liquefied gas concentration is helpful to assisted analysis of storage tank operation status and trend, can discover the potential safety hazards timely inside the storage tank, and then take effective measures to prevent and control the risks, so as to ensure the safety and stability of the oil and gas gathering and transportation industry. Within the limited space, affected by factors such as complexity, high dimension, strong correlation and weak regularity of storage tank operation data, the existing short-term prediction method of liquefied gas concentration is difficult to ensure the real-time performance and accuracy of prediction results. Therefore, we propose a short-term prediction method of liquefied gas concentration based on mixed intelligence. Firstly, we bring in an Extreme Change Function, and calculate the weighted set kurtosis value of the feature curve to realize feature dimension reduction. Secondly, the Convolutional Neural Network is used to mine the correlation between features and extract effective feature vectors. Meanwhile, we use Long Short-Term Memory Network to learn the change law of the data, so as to obtain the predicted value of liquefied gas concentration. Finally, our method is applied to a real scenario to demonstrate that the short-term prediction method of liquefied gas concentration achieves superior results in prediction accuracy, running speed and stability compared with other methods. [ABSTRACT FROM AUTHOR]

Aims: Using high‐protein caragana as an unconventional feed supplement has promising application potential in livestock feeding programmes, and verifying its function is of great importance to guide efficient dietary management of livestock. Methods and Results: This study investigated the resulting changes in the growth, slaughter performance, serum physiological index, physical and chemical characteristics of meat, ruminal and intestine morphology and gastrointestinal tract microbiota in sheep fed with caragana (CAR), corn straw (COR) and alfalfa (ALF) diets. The CAR group showed an increased abundance of Christensenellaceae R‐7 group, Marvinbryantia, Ruminococcaceae NK4A214, Lachnospiraceae UCG‐002 and Desulfuromonas in the rumen compared with ALF, and CAR group mainly enhanced starch and sucrose metabolism, fructose and mannose metabolism, photosynthesis and d‐alanine metabolism in the rumen compared with ALF. Conclusions: CAR diet positively changed the fatty acid profile of longissimus dorsi muscle and significantly altered the composition and function of the microbiota in the rumen, ileum and cecum. Significance and Impact of the Study: This study systematically demonstrated the feasibility of CAR as an alternative to ALF for animal fattening in a complete formula granulated feed and provided a fundamental basis for further research and development of CAR as an unconventional feed source for ruminants. [ABSTRACT FROM AUTHOR]

Background: Children with intellectual disabilities (ID) typically master walking skills much later than typically developing (TD) children and have poor postural control ability. This study aimed to explore the gait ability and characteristics of children with ID and whether there is any difference in walking ability between them and TD children. Method: In this study, integrating kinematic–biomechanic–dynamic measurement methods and corresponding analysis methods (video analysis, three‐dimensional force analysis and electromyography test analysis) were used to characterise and compare the gait patterns between ID children and TD children. Results: ID children's step length/leg length ratio was lower than TD children. The left‐leg single‐leg support time and step length of ID children were shorter than TD children. While walking, ID children touched the ground with the whole foot pad and could not powerfully thrust against the ground with their toes. Their left legs had obvious disadvantages compared with their right legs. ID children's lower limb muscle strength was lower than TD children, and their thigh muscles had an obvious compensation function. Conclusions: Correcting ID children's gait should be an important teaching goal for physical education institutors and teachers. Muscle‐strength and flexibility training can help ID children reinforce core strength and better coordinate lower limbs. [ABSTRACT FROM AUTHOR]

We systematically analyse two GRB samples with radio-loud and radio-quiet afterglows, respectively. It is interestingly found that the radio-selected GRB samples exhibit a clear dichotomy in terms of their distributions of intrinsic durations (T int), isotropic energies in γ-rays (E γ, iso), the circum-burst medium density (n), the spectral radio peak luminosity (L ν, p ) and flux densities (F host) of host galaxies. On average, the values of T int, E γ, iso, n, L ν, p , and F host of radio-quiet GRBs are relatively smaller than those of radio-loud ones. However, the redshifts and host flux densities of both samples are similarly distributed. In addition, a positive power-law correlation of |$L_{\nu ,p}\propto E_{\gamma ,\rm iso}^{0.41\pm 0.04}$| is found for the radio-loud sample, especially in accord with the supernova-associated GRBs, which is marginally consistent with that of the radio-quiet GRB sample. A negative correlation between T int and z is confirmed to similarly hold for both radio-loud and radio-quiet GRBs. The dividing line between short and long GRBs in the rest frame is at T int ≃1 s. Consequently, we propose that the radio-selected GRBs could be originated from distinct progenitors and central engines, together with environments. [ABSTRACT FROM AUTHOR]

Phytochelatins (PCs) constitute an important mechanism for plants to resist heavy metal stress. Widely found in higher plants, they are small heavy metal binding peptides, synthesized through catalysis of phytochelatin synthase (PCS). We speculate that there may be PCS genes in Peacock grass (Tagetes patula L., Asteraceae), which is an important reason for its rich cadmium.In order to obtain the full‐length cDNA sequence of the PCS gene from T. patula L. used rapid amplification of cDNA ends (RACE). Meanwhile, Relative expression of TpPCS1 under different concentrations of cadmium (Cd) stress was analysed using quantitative real‐time polymerase chain reaction (qRT‐PCR).Results found ORF of TpPCS1 genes with a length of 1970 bp, a gene coding area length of 1764 bp, coding for 587 amino acids. Expression of TpPCS1 under Cd stress was tissue specific. TpPCS1 in the root showed higher expression, while expression in the leaf and seed was relatively low.This research demonstrates that expression of TpPCS1 enhanced the enrichment of cadmium in T. patula L. roots and could be used to construct a plant hyperexpression carrier that would provide new avenues for plant restoration technology. [ABSTRACT FROM AUTHOR]

The viability of graphene-based microporous layers (MPLs) for polymer electrolyte membrane fuel cells is critically assessed through detailed characterisation of the morphology, microstructure, transport properties and electrochemical characterisation. Microporous layer composition was optimised by the fabrication of several hybrid MPLs produced from various ratios of graphene to Vulcan carbon black. Single cell tests were performed at various relative humidities between 25% and 100% at 80 °C, in order to provide a detailed understanding of the effect of the graphene-based MPL composition on the fuel cell performance. The inclusion of graphene in the MPL alters the pores size distribution of the layer and results in presence of higher amount of mesopores. Polarisation curves indicate that a small addition of graphene (i.e. 30 wt %) in the microporous layer improves the fuel cell performance under low humidity conditions (e.g. 25% relative humidity). On the other hand, under high humidity conditions (≥50% relative humidity), adding higher amounts of graphene (≥50 wt %) improves the fuel cell performance as it creates a good amount of mesopores required to drive excess water away from the cathode electrode, particularly when operating with high current densities. [Display omitted] • Microporous layers were fabricated with varying weight inclusions of graphene. • Composite MPLs were characterised by their morphology, microstructure and electrochemical properties. • Lower graphene concentrations (30%) improved cell performance in low humidity conditions. • Graphene concentration at 50 wt % or above enhances cell performance in high humidity conditions. [ABSTRACT FROM AUTHOR]

This study was conducted to determine whether protein solubility (PS) of rapeseed meals (RSM) can affect standardized ileal amino acid digestibility (SIDAA) in meat ducks. A total of 1,168, 14-days-old ducks were randomly allotted to 23 treatments (6 cages per diet, 8 ducks per cage) and 1 nitrogen-free diet treatment (8 cages, 8 ducks per cage) based on body weight. The 23 experimental diets consisted of a corn–soybean meal basal diet, and 22 diets containing 15% RSM: 85% basal diet. Titanium dioxide (0.5%) was included in all diets as an indigestible marker. On day 18, all ducks were euthanized by carbon dioxide asphyxiation and digesta samples from the ileum. The contents of PS, ether extract (EE), glucosinolate, isothiocyanate, and oxazolidine were significantly different (P < 0.05) in the 22 RSM, with the CV being 52.62, 49.23, 86.84, 90.19, and 81.98%, respectively. The content of lysine (Lys) and methionine in the 22 RSM samples ranged from 1.03 to 2.71% (CV 24.19%) and from 0.33 to 0.65% (CV 15.17%), respectively. The SIDAA, except for leucine (Leu) and tyrosine, of the 22 RSM samples varied significantly (P < 0.05). A positive correlation was observed (P < 0.05) between PS and standardized ileal digestibility (SID) of Lys, isoleucine, valine, phenylalanine, histidine, serine, cysteine, and tyrosine. The R² value of multiple linear regression equations for predicting the SID of amino acids (AA) was best for Lys (R2 = 0.958 using dry matter, crude protein, EE, crude fiber, acid detergent fiber, and PS) and least significant for Leu (R² = 0.348 using crude fiber and ash) with intermediate values for other AA (R² = 0.359–0.837, P < 0.05). These results suggest that PS varying from 15.06 to 98.08%, also varied considerably in the proximate nutrient content, AA composition, and antinutritional factor content, which was reflected in considerable differences in the duck's SID of AA in RSM. Therefore, PS value can partly reflect the quality of RSM. [ABSTRACT FROM AUTHOR]

Rotor redesign approaches have been widely proposed to solve the thrust mismatch issue caused by scaling effects for basin model tests of horizontal axis floating wind turbines (FWTs). However, limited basin model tests utilized the thrust-matched rotor (TMR) to accurately evaluate the aerodynamic loads applying to the vertical axis FWTs. This paper described the detailed design approach of the TMR of floating straight-bladed vertical axis wind turbines (VAWTs) with a rated power of 5.3 MW. First, the AG455 airfoil was selected to replace the NACA0018 airfoil. AG455 airfoil can show a larger lift coefficient and a smaller drag coefficient at low Reynolds number. On this basis, the load distribution match algorithm was used to assign the blade pitch angle and chord length at each section of the blade. This method takes the spanwise load and load change rate of model-scaled blade and full-scaled blade as the constraint conditions. By adopting this method, the rotor thrust can be tailored to match the prototype values across a wide range of tip speed ratios. This design approach proves advantageous in assessing the aerodynamic performance of VAWTs under varying inflow wind speeds and unsteady wind conditions. The redesigned TMR model under low Reynolds number can meet Froude similarity criterion, which is helpful to improve the accuracy of vertical axis FWT model tests in the wave basin. [ABSTRACT FROM AUTHOR]

The ELAV/Hu family is a conserved multigene family of pan‐neuronal RNA‐binding protein involved in post‐transcriptional regulation in metazoans. In Drosophila, three members of this family, ELAV, RBP9 and FNE, are involved in neuronal differentiation, gene expression regulation and so on. This family is less well characterized in Bombyx mori. Two orthologs BmELAV‐like‐1 (BmEL‐1) and BmELAV‐like‐2 (BmEL‐2) share 55%–71% and 47%–62% identity with that of in Drosophila and humans, respectively. Bmel‐1 is ubiquitously expressed while Bmel‐2 is expressed in the head and ovaries specifically. Proteins encoded by both genes are localized in nuclear and cytoplasm. The weight of body, cocoon, pupae and cocoon shell are differently affected in Bmel‐1−/−2− mutants created using CRISPR/Cas9 technology. Mutations of both genes increase the expression of four silk protein genes, Fib‐L, Fib‐H, P25 and Ser‐1. In addition, the oviposition ability of Bmel‐2− females is decreased. This study not only provides valuable insights into the functional roles of Bmelav‐like genes in the growth, cocoon characters and regulation of silk protein genes expression, but also provides useful information for silkworm variety breeding. [ABSTRACT FROM AUTHOR]

The present study aims to investigate the protective effects of Dendrobine and its underlying mechanisms on liver injury induced by isoniazid (INH) and rifampicin (RIF). A mouse model of liver injury was induced by intragastrically administration of 100 mg/kg INH and 100 mg/kg RIF for 14 days. The mice were intragastrically administrated with Dendrobine (50, 100, and 200 mg/kg) before the administration of INH and RIF. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. Oxidative stress markers including glutathione, superoxide dismutase, and malondialdehyde in the liver were measured and liver histopathological examinations were performed. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot were applied to determine the mRNA and protein expressions, respectively. Luciferase reporter assay was used to evaluate the interactions between miR-295-5p and CYP1A2. Dendrobine significantly decreased serum ALT and AST and inhibited the liver index and ameliorated the liver histological changes induced by INH and RIF. Besides, Dendrobine also regulated oxidative stress status in the liver by the regulation of CYP1A2. Moreover, mmu-miR-295-5p was identified to target CYP1A2 and to regulate the expression of CYP1A2. In summary, Dendrobine ameliorated INH and RIF induced mouse liver injury by miR-295-5p-mediated CYP1A2 expression. [ABSTRACT FROM AUTHOR]

Accretionary orogens contain key evidence for the conversion of oceanic to continental crust. The late tectonic history and closure time of the Palaeo-Asian Ocean are recorded in the Mazongshan subduction–accretion complex in the southern Beishan margin of the Central Asian Orogenic Belt. We present new data on the structure, petrology, geochemistry and zircon U–Pb isotope ages of the Mazongshan subduction–accretion complex, which is a tectonic mélange with a block-in-matrix structure. The blocks are of serpentinized peridotite, basalt, gabbro, basaltic andesite, chert and seamount sediments within a matrix that is mainly composed of fore-arc-trench turbidites. U–Pb zircon ages of two gabbros are 454.6 ± 2.5 Ma and 434.1 ± 3.6 Ma, an andesite has a U–Pb zircon age of 451.3 ± 3.5 Ma and a tuffaceous slate has the youngest U–Pb zircon age of 353.6 ± 5.1 Ma. These new isotopic ages, combined with published data on ophiolitic mélanges from central Beishan, indicate that the subduction–accretion of Beishan in the southernmost Central Asian Orogenic Belt lasted until Late Ordovician – Early Carboniferous time. Structure and age data demonstrate that the younging direction of accretion was southwards and that the subduction zone dipped continuously to the north. Accordingly, these results record the conversion of oceanic to continental crust in the southern Beishan accretionary collage. [ABSTRACT FROM AUTHOR]

1. Egg-laying traits are important economic characteristics in goose production (Anser cygnoides). The gene GnRH, which encodes gonadotropin-releasing hormone, is a strong candidate gene for egg-laying traits in avian species. 2. In this study, a 3520 bp genomic sequence and a 279 bp mRNA sequence for GnRH, which encoded 92 amino acids, were determined. The GnRH DNA sequence contains four exons and three introns, and the DNA and deduced amino acid sequences were highly conserved across mammals (human, macaque, cow, and sheep) and avians (chicken, fulmar and quail). 3. Using a direct sequencing method, 46 single nucleotide polymorphisms (SNPs) were identified in the GnRH genomic sequence that were shared between two Sichuan White goose populations (217 and 208 individuals). Furthermore, 44 haplotypes were constructed using a sliding window approach. Association analysis between the SNPs and haplotypes and egg-laying traits showed that 10 SNPs affected the first egg weight, average egg weight, egg number at 48 weeks and egg number at 64 weeks. 4. These results lay the foundation for further studies of the function of GnRH in geese and provide a theoretical basis for marker-assisted selection of egg-laying traits in the Sichuan white goose population. [ABSTRACT FROM AUTHOR]

A total of 560 one-day-old Pekin ducks were randomly allocated to 7 treatments with 8 replicate cages of 10 ducks per cage. The treatments included a corn-rice bran-soybean meal-based diet with recommended nonphytate phosphorus (NPP) (0.40% for 1-14 D/0.35% for 15-35 D, positive control; PC), NPPdeficient diet (0.22% for 1-14 D/0.18% for 15-35 D, negative control; NC), and NC diets supplemented with different levels of phytase (500, 2,500, 5,000, 7,500, 10,000 FTU/kg). Compared with the PC diet, feeding the NC diet significantly decreased (P, 0.05) the bird growth performance, serum total protein, and albumin concentration as well as tibia bone mineralization and strength and increased (P, 0.05) serum calcium (Ca), urea content, and alkaline phosphatase activity throughout the experimental period. Phytase supplementation to NC diets at 5,000 to 10,000 FTU/kg restored (P, 0.05) growth performance, serum biochemical parameters, and tibia traits when compared with the levels of the PC. Moreover, the addition of phytase linearly increased (P, 0.05) dietary protein, Ca, and phosphorus (P) utilization as well as nitrogen output, and excreta iron, copper, manganese, and zinc concentration quadratically increased (P, 0.05) as well as P output. In conclusion, phytase at 5,000 FTU/kg was effective in ameliorating the negative effects of NC diets and reducing trace mineral supplementation in diet of Pekin ducks. [ABSTRACT FROM AUTHOR]

Summary: Domestication of the Bovini species (taurine cattle, zebu, yak, river buffalo and swamp buffalo) since the early Holocene (ca. 10 000 BCE) has contributed significantly to the development of human civilization. In this study, we review recent literature on the origin and phylogeny, domestication and dispersal of the three major Bos species – taurine cattle, zebu and yak – and their genetic interactions. The global dispersion of taurine and zebu cattle was accompanied by population bottlenecks, which resulted in a marked phylogeographic differentiation of the mitochondrial and Y‐chromosomal DNA. The high diversity of European breeds has been shaped through isolation‐by‐distance, different production objectives, breed formation and the expansion of popular breeds. The overlapping and broad ranges of taurine and zebu cattle led to hybridization with each other and with other bovine species. For instance, Chinese gayal carries zebu mitochondrial DNA; several Indonesian zebu descend from zebu bull × banteng cow crossings; Tibetan cattle and yak have exchanged gene variants; and about 5% of the American bison contain taurine mtDNA. Analysis at the genomic level indicates that introgression may have played a role in environmental adaptation. [ABSTRACT FROM AUTHOR]

Length-weight relationship, growth and mortality rate parameters of Tighertooth croaker (Otolithes ruber) were estimated using length-weight and data length frequency distributions, samples gathered from different fish landing sites of Balochistan coast, Pakistan. A total of 278 pairs of length-weight relationship and 4062 samples of length frequency distribution were measured during current study. Length-weight relationship was at a =0.016, b =2.829 (R²= 0.969). ELEFAN method was used to evaluate the growth rate where L∞= 34.65 cm and K =0.83 yr-1 and t0= -0.185, growth performance index was at 2.608 yr-1. Length converted catch curve was used to estimate total mortality which was Z =3.18 yr-1, whereas, fishing and natural death of fish evaluated at 1.465, 2.171 yr-1 respectively, however, exploitation rate (E) was at 0.682 yr-1. Pursuant to Gulland (1971, 1979) exploitation rate would be less than 0.5 and Patterson (1992) reported exploitation rate may retained at 0.4 level for sustainable fishery resources. Considering above facts, stock of O. ruber from Pakistani waters (Balochistan coast) is in overexploitation state. It may be suggested to government agencies to initiate rules and regulations to sustain the stock of this fishery from Pakistani waters for future. [ABSTRACT FROM AUTHOR]

Graphene deposited on planar surfaces often exhibits sharp and localized folds delimiting seemingly planar regions, as a result of compressive stresses transmitted by the substrate. Such folds alter the electronic and chemical properties of graphene, and therefore, it is important to understand their emergence, to either suppress them or control their morphology. Here, we study the emergence of out-of-plane deformations in supported and laterally strained graphene with high-fidelity simulations and a simpler theoretical model. We characterize the onset of buckling and the nonlinear behavior after the instability in terms of the adhesion and frictional material parameters of the graphene-substrate interface. We find that localized folds evolve from a distributed wrinkling linear instability due to the nonlinearity in the van der Waals graphene-substrate interactions. We identify friction as a selection mechanism for the separation between folds, as the formation of far apart folds is penalized by the work of friction. Our systematic analysis is a first step towards strain engineering of supported graphene, and is applicable to other compressed thin elastic films weakly coupled to a substrate. [ABSTRACT FROM AUTHOR]

1. The study objectives were to determine the direct effects of gonadotropin-releasing hormone (GnRH) on the proliferation of ovarian granulosa cells (GCs) and the development of follicles in geese (Anser cygnoides) by colorimetry and ethynyl-2′-deoxyuridine (EdU) cell proliferation assays, in which primary GCs were treated with different concentrations of GnRH agonist (alarelin acetate) and an antagonist (cetrorelix acetate). Differently expressed genes (DEGs) were identified by RNA-sequencing and validated by quantitative reverse transcription polymerase chain reaction (RT–qPCR) and Western blotting. 2. The EdU assays showed that the proliferation of GCs was affected by the GnRH agonist and antagonist in a dose-dependent manner. The effect of treatment on cell proliferation was statistically significant at the concentrations of 10−5 mol/l alarelin and 1 mg/l cetrorelix acetate. A total of 134 DEGs (76 downregulated and 58 upregulated for alarelin treatment) and 226 DEGs (90 downregulated and 136 upregulated for cetrorelix) were identified by RNA-sequencing analysis, respectively. Enrichment analysis indicated that DEGs were enriched in the GO terms of cell–cell signalling and cell junctions. The pathways that regulate the development of follicles were identified, including the biological progress of cAMP accumulation, ovulation cycle and vasculature that are essential to follicular selection. 3. The results suggested that GnRH might directly regulate GC proliferation via autocrine or paracrine pathways related to cell junctions. In particular, it was confirmed that the mRNA and protein expression levels of the oestrogen receptor 2 (ESR2) gene, a negative transcription factor involved in follicular maturation and ovulation, were affected by GnRH agonist or antagonist in GCs. 4. In conclusion, GnRH might play an important role in follicular development by changing the expression of genes that participate in cAMP accumulation, ovulation cycle and cell junctions in ovarian GCs. [ABSTRACT FROM AUTHOR]

Low temperature (LT) is an important elicitor that triggers anthocyanin biosynthesis. To investigate whether the reactive oxygen species (ROS) produced via RBOH are involved in this process, we analysed the function and mechanism of ROS produced via RBOH during LT-induced anthocyanin biosynthesis in Begonia semperflorens Link & Otto. The results showed that BsRBOHD transcription was upregulated in LT-grown seedlings at the 3rd hour, which was followed by the upregulation of anthocyanin-biosynthesis genes at the 5–9th hour, leading to anthocyanin accumulation on the 2nd day. The LT-induced increases in ROS production, BsRBOHD and anthocyanin-biosynthesis gene transcription, and anthocyanin content were abolished by the pre-treatment of seedlings with DPI [an inhibitor of nicotinamide adenine nucleoside phosphorylase (NADPH) oxidase or DMTU (a H2O2 scavenger)], but were promoted by pre-treatment with NADPH (a substrate of NADPH oxidase). Changes in the chlorophyll fluorescence parameters showed that pre-treatment of DPI or DMTU alleviated the LT-induced decrease in the seedling chlorophyll content and a/b ratio, which subsequently alleviated the LT-induced decreases in the ABS/CSm, TRo/CSm, RC/CSm, ETo/CSm and REo/CSm values. In contrast, NAPDH pre-treatment intensified these changes. Therefore, we suggest that ROS produced via BsRBOHD may be involved in the LT-induced anthocyanin biosynthesis by strengthening the overaccumulation of ROS produced by the overexcitation of PSII reaction centres and overflux from to NADP+ in B. semperflorens. [ABSTRACT FROM AUTHOR]

The tachinid fly Drino inconspicuoides (Diptera: Tachinidae) is an ovolarviparous endoparasitoid whose larvae develop in the host haemocoel and avoids the host immune system. In this study, we investigated the immune evasion mechanisms of this species during infestation in the host Mythimna separata (Lepidoptera: Noctuidae). We discovered a unique 'cloak' that surrounded D. inconspicuoides larvae that penetrated into the host and determined through genomic polymerase chain reaction analysis that this structure originated from the host rather than the tachinid. The 'cloak' contained both haemocytes and fat body cells from the host, with the haemocytes assembling around the larvae first and the fat body cells then covering the haemocyte layer, following which the two mixed. Living D. inconspicuoides larvae that were wrapped in the 'cloak' were not melanized whereas encapsulated dead larvae were melanized, suggesting that this structure contributes to the avoidance of host immune reactions. [ABSTRACT FROM AUTHOR]

The objective of the present study was to investigate the effect of dietary graded raw potato starch (RPS) levels on growth performance, plasma cytokines concentration, ileal barrier function, and cecal short-chain fatty acids (SCFA) concentration in meat ducks from 1 to 35 D of age. This study included 2 experiments. In experiment (Exp.) 1, sixteen 35-day-old meat ducks were used to evaluate the AME of RPS by orogastric administration. Results showed the AME value of RPS on ducks is 2.76 kcal/g. In Exp. 2, a total of 600 one-day-old ducklings were randomly assigned to 5 isonitrogenous and isoenergetic dietary treatments that included 0 (control), 6, 12, 18, and 24% RPS, respectively. Samples were collected at both of 14 and 35 D. Neither growth performance nor ileal parameters (length, weight, and pH) at both of 14 and 35 D was affected by dietary RPS. However, the mucosal thickness (14 D), villus height (except for 18% RPS at 14 D), and the villus height: crypt depth ratio (14 and 35 D) of the ileum were increased in the 12 and 18% RPS diets when compared to 0% RPS diet. Meanwhile, proinflammatory factors such as plasma interleukin (IL)-1β and IL-6 (14 D) reduced in 12% RPS diet and tumor necrosis factor α decreased in 12% (except for 14 D) and 18% RPS groups. When compared with the control group, diets with 18% RPS significantly increased mucin 2 gene expression at 14 D, and 12% RPS elevated the mRNA expression of tight junction proteins including Zonula occludens-1 and Claudin 1 (except for 14 D) in the ileal mucosa of birds. Furthermore, ducks fed 12% RPS diet had higher concentrations of acetate, propionate, and butyrate in cecal digesta than other groups. These findings indicated that diets with 12 and/or 18% RPS increased the cecal SCFA concentration, which subsequently enhanced the barrier function and improved intestinal health in the ileum for 14 and 35-day-old meat ducks. [ABSTRACT FROM AUTHOR]

The structural patterns of periodic cellular materials play an important role in their properties. Here, we investigate how these patterns transform dramatically under external stimuli in simple periodic cellular structures that include a nanotube bundle and a millimeter-size plastic straw bundle. Under gradual hydrostatic straining up to 20%, the cross-section of the single walled carbon nanotube bundle undergoes several pattern transformations, while an amazing new hexagram pattern is triggered from the circular shape when the strain of 20% is applied suddenly in one step. Similar to the nanotube bundle, the circular plastic straw bundle is transformed into a hexagonal pattern on heating by conduction through a baseplate but into a hexagram pattern when heated by convection. Besides the well-known elastic buckling, we find other mechanisms of pattern transformation at different scales; these include the minimization of the surface energy at the macroscale or of the van der Waals energy at the nanoscale and the competition between the elastic energy of deformation and either the surface energy at the macroscale or the van der Waals energy at the nanoscale. The studies of the pattern transformations of periodic porous materials offer new insights into the fabrication of novel materials and devices with tailored properties. [ABSTRACT FROM AUTHOR]

Ripple patterns created by sputter erosion of iron thin films induce a correlated magnetic texture of the surface near region. We investigated the magnetic anisotropy as a function of the residual film thickness and determined the thickness of the magnetically anisotropic layer as well as the magnitude of the magnetic anisotropy using by magneto-optical Kerr effect (MOKE) and Rutherford backscattering spectroscopy measurements. Ripple patterns were created by sputter erosion with 5 keV Xe ions under grazing incidence of 80° with respect to the surface normal. For ion fluences of above 1×1016 cm-2, the formation of ripples, with wavelengths between 30 and 80 nm oriented parallel to the ion beam direction, is observed. MOKE measurements reveal a pronounced uniaxial magnetic anisotropy of the surface region of the films with orientation parallel to the ripple orientation and the ion beam direction. We find a layer thickness of 12±3 nm, in accordance with the average grain size. The magnetic anisotropy within this layer varies from about 25% for thick residual films toward 100% for films with less than 30 nm thickness. The magnitude of the magnetic anisotropy is determined by the shape anisotropy of the rippled surface as well as the interface roughness. We have demonstrated that sputter erosion yields highly anisotropic magnetic thin films and can be used to fabricate nanorods and nanowires with pronounced uniaxial magnetic anisotropy. [ABSTRACT FROM AUTHOR]

Si/Fe/Si trilayers, with 12 nm amorphous Si and 45 nm polycrystalline Fe films deposited on Si(100) wafers, were irradiated with 350 MeV Au26+ ions at fluences of (0.6–11.3)×1014 ions/cm2. The ion-induced modifications of their structural and magnetic properties were characterized by means of Rutherford backscattering, glancing angle x-ray diffractometry, and the magneto-optical Kerr effect. The mixing rate at the upper a-Si/Fe interface was three times as high as that at the lower Fe/c-Si interface. A simple formula is proposed, which on the basis of (nuclear) thermal-spike mixing reproduces the observed (electronic) mixing rates. Ion irradiation at a moderate fluence (6.7×1014/cm2) induced a magnetic anisotropy in the sample, which was magnetically isotropic after deposition. At the highest fluence, full interface mixing occurred and the magnetic anisotropy almost disappeared. The results are compared with those obtained in Fe/Si and Ni/Si bilayers ion irradiated in the regimes of nuclear and electronic stopping. [ABSTRACT FROM AUTHOR]

Iron (Fe) oxyhydroxides are major phases that may control the cerium (Ce) behavior in the Earth's Critical Zone. However, understanding Ce behavior with Fe oxyhydroxides remains uncompleted. Especially, if thermodynamic calculations suggest that Fe(III) is not a sufficiently strong oxidant, several studies reported the presence of Ce(IV) onto Fe oxyhydroxides. In this study, multiple approaches, including modeling and X-ray absorption spectroscopy, deciphered the driving forces of Ce(III) oxidation to Ce(IV) onto goethite. Results showed that oxidized Ce occurred onto goethite with a Ce(III)/Ce(IV) ratio depending on the Ce concentration in the solution ([Ce] tot). The percentage of Ce(IV) onto goethite ranged from 20% to 50%, linearly increasing with [Ce] tot. Comparable observation with a redox-inert Al-hydroxide (gibbsite), allowed to rule out the importance of Fe(III) redox reactivity as the main driver of Ce(III) oxidation. Instead, thermodynamic calculations suggested that surface precipitation of Ce(IV)-hydroxides, whose formation is favored with increasing [Ce] tot , was an important driving force of the redox reaction. Because the goethite surface seemed to stabilize more strongly Ce(IV) than Ce(III) surface species than does gibbsite, differences in binding mechanisms of Ce(III) and Ce(IV) onto different mineral surfaces have been suggested to play a role on Ce redox speciation. [Display omitted] [ABSTRACT FROM AUTHOR]

In-grain microplasticity and intergranular microdamage in polycrystalline hexagonal-structure ceramics subjected to a sequence of dynamic compression and tension are studied computationally using the Voronoi polycrystal model, by which the topological heterogeneity and material anisotropy of the crystals are simulated explicitly. The constitutive modeling considers crystal plasticity by basal slip, intergranular shear damage during compression, and intergranular mode-I cracking during tension. The model parameters are calibrated with the available shock compression and spall strength data on polycrystalline α-6H silicon carbide. The numerical results show that microplasticity is a more plausible micromechanism for the inelastic response of the material under shock compression. On the other hand, the spallation behavior of the shocked material can be well predicted by intergranular mode-I microcracking during load reversal from dynamic compression to tension. The failure process and the resulting spall strength are, however, affected strongly by the intensity of local release heterogeneity induced by heterogeneous microplasticity, and by the grain-boundary shear damage during compression. [ABSTRACT FROM AUTHOR]

Reflection-absorption infrared spectroscopy has been employed to observe Si-H bonds within a model, ultrathin silicon oxide. Upon heating a monolayer of H[sub 8]Si[sub 8]O[sub 12]/Si(100 - 2 × 1 to 700 °C, Si-H bonds as a part of HSiO[sub 3] entities are still detected within the oxide layer after cooling. These fragments appear to be stable to temperatures of at least 850 °C. Reversible hydrogen/deuterium exchange for these entities is also directly observed. [ABSTRACT FROM AUTHOR]

The crystallization kinetics of amorphous Sm[sub 8]Fe[sub 85]Si[sub 2]C[sub 5] alloy has been investigated. As the alloy is heated to 900 °C, the crystalline phases of the alloy are composed of α-Fe phase and Sm[sub 2](Fe, Si)[sub 17]C[sub x]. At the beginning of crystallization the activation energy of the α-Fe phase is about 425 kJ/mol, it remains relatively constant as the crystallized fraction of the α-Fe phase is below 70%, and then it declines with increasing the crystallized fraction. When the crystallized fraction of the Sm[sub 2](Fe, Si)[sub 17]C[sub x] is below 50%, the activation energy of crystallization of the phase remains between 518 and 530 kJ/mol, and then decreases with the crystallized fraction. The crystallization behavior of the α-Fe phase and Sm[sub 2](Fe, Si)[sub 17]C[sub x] essentially results in the formation of an α-Fe/Sm[sub 2](Fe, Si)[sub 17]C[sub x] composite microstructure with a coarse grain size in annealed Sm[sub 8]Fe[sub 85]Si[sub 2]C[sub 5] alloy, which is attributed to a difficult nucleation and an easy growth for both the α-Fe phase and Sm[sub 2](Fe, Si)[sub 17]C[sub x] in the alloy. Cu and Nb can be used to change the crystallization behavior of the α-Fe phase in the amorphous Sm[sub 8]Fe[sub 85]Si[sub 2]C[sub 5] alloy, which is helpful to the formation of the α-Fe/Sm[sub 2](Fe, Si)[sub 17]C[sub x] nanocomposite microstructure with a fine grain size for the α-Fe phase in the alloy. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Focuses on a study conducted on an ultrafine-grained (UFG) Ni sample which was processed by severe plastic deformation, using x-ray diffraction investigations in a temperature ranging from 85 to 295 K. Details on the thermal behavior of atoms in UFG Ni; Information on the temperature dependence of the lattice parameter; Calibration of the geometrical conditions of the instrument.

Inclusion complex nanoparticles of puerarin and ß-cyclodextrin were prepared using solution-enhanced dispersion by supercritical fluids to improve the dissolution rate of puerarin. The factors that influenced particle size and inclusion yield such as, pressure, temperature, flow rate of CO2, and flow rate of the solution, were investigated. Scanning electron microscopy, X-ray diffraction and Fourier-transform infrared spectroscopy were used to characterize the products. Release behaviour of inclusion complex nanoparticles of puerarin was also studied. Elevated temperatures increased the inclusion yield. Elevated pressures reduced the particle size. Scanning electron microscopy, X-ray diffraction and Fourier-transform infrared spectroscopy confirmed the formation of inclusion complex nanoparticles of puerarin. The accumulated release rate of inclusion complex nanoparticles of puerarin reached 98 % within 5 min, markedly higher than that of the puerarin powder and its physical mixture. Inclusion complex nanoparticles of puerarin prepared by solution-enhanced dispersion by supercritical fluids can greatly improve the in vitro release of puerarin. [ABSTRACT FROM AUTHOR]

Highlights • Single bubble motion characteristics in inclined tube bundles were analyzed. • A new hypothesis of velocity decomposition and resistance superposition was proposed. • Theoretical models were developed to predict single bubble deviation angles in inclined tube bundles. Abstract A theoretical investigation on single bubble motion in inclined tube bundles was carried out. Due to the shear flow caused by the nonhomogeneous velocity distribution in an inclined tube bundle, single bubble motion was affected by the lift force in the horizontal direction. As a result, the flow direction of single bubble may deviate from the buoyancy direction. Then, both force analyses and velocity decompositions of two-phase in inclined tube bundles were conducted. Based on several hypotheses, a theoretical single-region model for D b > D ins and a two-region model for D b < D ins were developed to predict deviation angles of single bubble motion in inclined tube bundles. In general, more than 75 percent of Todreas's data could be evaluated well by the new developed models with a devaition of ±50% when D b ≥ D c. However, the developed models can not present excellent predictions for several deviation angle data when D b < D c , especially when S L - d < D b < D c. This unsatisfied agreements may be related to two factors. The one is the unsatisfied repearability of Todreas's data. The other one is that several flow mechanisms of small bubbles in inclined tube bundles are not clear yet. It's suggested that further experimental and theoretical investigations on mechanisms of bubble rotation, bubble entrainment and bubble bouncing at the curve surfaces of tubes could be conducted. [ABSTRACT FROM AUTHOR]