The effect of sheared E × B flow on the blob dynamics in the scrape-off layer (SOL) of HL-2A tokamak has been studied during the plasma current ramp-up in ohmically heated deuterium plasmas by the combination of poloidal and radial Langmuir probe arrays. The experimental results indicate that the SOL sheared E × B flow is substantially enhanced as the plasma current exceeds a certain value and the strong sheared E × B flow has the ability to slow the blob radial motion via stretching its poloidal correlation length. The locally accumulated blobs are suggested to be responsible for the increase of plasma density just outside the Last Closed Flux Surface (LCFS) observed in this experiment. The results presented here reveal the significant role played by the strong sheared E × B flow on the blob dynamics, which provides a potential method to control the SOL width by modifying the sheared E × B flow in future tokamak plasmas.

We investigate the heat transfer and coherent structures in Taylor–Couette (TC) flows that undergo thermal convection driven by an axially applied temperature gradient. Direct numerical simulations are performed in a Rayleigh number range $10^6 \leq Ra \leq 3 \times 10^8$ for Prandtl number $Pr = 4.38$ and with the shear Reynolds number up to $Re = 10^4$. When the rotation number $R_f$ increases, the flows undergo a transition from buoyancy-dominated ($R_f<1$) to shear-dominated convection ($R_f>1$). In the buoyancy-dominated regime with weak rotations, the flow features are similar to those in Rayleigh–Bénard (RB) convection with large-scale plumes emanating from the thermal boundary layers. In this regime, the $Re$-dependence of heat transport $Nu$ is sensitive to $Ra$. We find that for low $Ra$, $Nu$ decreases with increasing $Re$ and becomes independent of $Re$ at high $Ra$. In the shear-dominated regime, the flow structures are characterised by Taylor vortices (TVs), which effectively enhance the heat transport. With sufficiently high Reynolds number for $2000< Re \le 10\,000$, the flow structures are dominated by turbulent TVs, and the transport scaling laws of heat and angular velocity fluxes become independent of buoyancy. We report that in this turbulent regime the axial heat-transport scaling $(Nu\sim Re^{0.578\pm 0.018})$ is consistent with the scaling of radial angular-momentum transport $(Nu_{\omega }\sim Re^{0.581\pm 0.026})$.

To compare sensitivity of specimens for COVID-19 diagnosis, we tested 151 nasopharyngeal/midturbinate swab pairs from 117 COVID-19 inpatients using reverse-transcriptase polymerase chain reaction (RT-PCR). Sensitivity was 94% for nasopharyngeal and 75% for midturbinate swabs (P = .0001). In 88 nasopharyngeal/midturbinate pairs with matched saliva, sensitivity was 86% for nasopharyngeal swabs and 88% for combined midturbinate swabs/saliva.

Rumen-protected betaine (RPB) can enhance betaine absorption in the small intestine of ruminants, while betaine can alter fat distribution and has the potential to affect the meat quality of livestock. Hence, we hypothesized that RPB might also affect the meat quality of lambs. Sixty male Hu sheep of similar weight (30.47 ± 2.04 kg) were selected and randomly subjected to five different treatments. The sheep were fed a control diet (control treatment, CTL); 1.1 g/day unprotected-betaine supplemented diet (UPB); or doses of 1.1 g/day (low RPB treatment; L-PB), 2.2 g/day (middle RPB treatment; M-PB) or 3.3 g/day (high RPB treatment; H-PB) RPB-supplemented diet for 70 days. Slaughter performance, meat quality, fatty acid and amino acid content in the longissimus dorsi (LD) muscle, shoulder muscle (SM) and gluteus muscle (GM) were measured. Compared with CTL, betaine (including UPB and RPB) supplementation increased the average daily weight gain (ADG) (P < 0.05) and average daily feed intake (P < 0.01) of lambs. Rumen-protected betaine increased ADG (P < 0.05) compared with UPB. With increasing RPB doses, the eye muscle area of the lambs linearly increased (P < 0.05). Compared with CTL, betaine supplementation decreased water loss (P < 0.05) in SM and increased pH24 in the SM (P < 0.05) and GM (P < 0.05). Compared with UPB, RPB decreased water loss in the GM (P < 0.01), decreased shear force (P < 0.05) in the LD and SM and increased the pH of the meat 24 h after slaughter (pH24). With increasing RPB doses, the shear force and b* value in the LD linearly decreased (P < 0.05), and the pH24 of the meat quadratically increased (P < 0.05). Compared with CTL, betaine supplementation increased the polyunsaturated fatty acid in the GM (P < 0.05). Compared with UPB, RPB supplementation decreased the saturated fatty acid (SFA) content in the LD (P < 0.05) and increased the unsaturated fatty acids (UFA), mono-unsaturated fatty acids and UFA/SFA ratio in the LD (P < 0.05). Compared with CTL, the content of histidine in the LD increased with betaine supplementation. Compared with UPB, RPB supplementation increased the content of total free amino acids and flavor amino acids in the LD of lambs (P < 0.05). With increasing RPB, the isoleucine and phenylalanine contents in the LD linearly increased (P < 0.05). Overall, the data collected indicated that the meat quality of lambs (especially in the LD) improved as a result of betaine supplementation, and RPB showed better effects than those of UPB.

We report on a novel processing route to prepare La0.8Ce0.2(Fe0.95Co0.05)11.8Si1.2/Cu bulk composites by low-temperature hot pressing. With increasing copper content, the compressive strength of the composites first decrease and then increase owing to the buffering effect of copper, but the magnetocaloric effect reduces to some extent. Copper addition improves the thermal conductivity of the composites, which compensates for the decrease in thermal conductivity due to porosity. A relatively large entropy change of 5.75–7.19 J/(kg K) at 2 T near the Curie temperature (249 K), good thermal conductivity of 7.51–15.55 W/(m·K), and improved compressive strength of 151.1–248.0 MPa make these composites attractive magnetic refrigeration materials.

Surface exfoliation was observed on single-crystal silicon surface under the action of compressed plasma flow (CPF). This phenomenon is mainly attributed to the strong transient thermal stress impact induced by CPF. To gain a better understanding of the mechanism, a micro scale model combined with thermal conduction and linear elastic fracture mechanics was built to analyze the thermal stress distribution after energy deposition. After computation with finite element method, J integral parameter was applied as the criterion for fracture initiation evaluation. It was demonstrated that the formation of surface exfoliation calls for specific material, crack depth, and CPF parameter. The results are potentially valuable for plasma/matter interaction understanding and CPF parameter optimization.

Previously, the concept of Ply Drop Sequence (PDS) is introduced by the authors for the designing of composite laminated structures with multiple regions. Compared to deleting a contiguous innermost/outermost plies in the classical guide-based blending, using PDS is more flexible than dropping plies between adjacent regions. In this article, a new blending model called the Permutation for Panel Sequence (PPS) blending model is proposed to correct the problem of repeated searching of discrete points in the design space for the previous PDS blending model. The proposed method is also applied to an 18-panel horseshoe benchmark problem. The results demonstrate that the useful searching points in the PPS method are less than those in the PDS method when the number of the panels is less than the number of plies in the guide laminate, and the PPS method obtains a faster convergence speed compared with the PDS method.

The origins and phylogeny of different sheep breeds has been widely studied using polymorphisms within the mitochondrial hypervariable region. However, little is known about the mitochondrial DNA (mtDNA) content and phylogeny based on mtDNA protein-coding genes. In this study, we assessed the phylogeny and copy number of the mtDNA in eight indigenous (population size, n=184) and three introduced (n=66) sheep breeds in China based on five mitochondrial coding genes (COX1, COX2, ATP8, ATP6 and COX3). The mean haplotype and nucleotide diversities were 0.944 and 0.00322, respectively. We identified a correlation between the lineages distribution and the genetic distance, whereby Valley-type Tibetan sheep had a closer genetic relationship with introduced breeds (Dorper, Poll Dorset and Suffolk) than with other indigenous breeds. Similarly, the Median-joining profile of haplotypes revealed the distribution of clusters according to genetic differences. Moreover, copy number analysis based on the five mitochondrial coding genes was affected by the genetic distance combining with genetic phylogeny; we also identified obvious non-synonymous mutations in ATP6 between the different levels of copy number expressions. These results imply that differences in mitogenomic compositions resulting from geographical separation lead to differences in mitochondrial function.

The production of winter wheat (Triticum aestivum L.) is affected by crop population structures and field microclimates. This 3-year study assessed the effect of different precision planting patterns and irrigation conditions on relative humidity (RH), air and soil temperature within the canopy, intercepted photosynthetically active radiation (iPAR), evapotranspiration (ET), water productivity (WP) and grain yields. Field experiments were conducted from 2011 to 2014 on a two-factor split-plot design with three replicates. The experiments involved three precision planting patterns (single row, alternating single and twin rows [hereafter ‘single–twin’] and twin row) and three irrigation treatments (0 mm (I0), 90 mm (I90) and 180 mm (I180)). Planting patterns and irrigation treatments exerted a significant effect on RH, air and soil temperature, iPAR, ET, WP and grain yield. The lowest RH and iPAR levels were detected in the single row pattern. When the irrigation treatment was identical, the highest soil and air temperatures were detected in the single row pattern, followed by the single–twin row and twin row patterns. Compared with the single row, the single–twin and twin row patterns increased ET by 0·3 and 1·4, WP by 4·7 and 5·7% and yields by 6·0 and 7·9%, respectively. Compared with I0, the I90 and I180 irrigation treatments increased ET by 0·3 and 1·4%, and WP by 4·7 and 5·7%, respectively. The grain yields of the twin row pattern were 5·8 and 1·7% higher than those of the single row and single–twin row patterns, respectively. Compared with I0, I90 increased yield by 19·3%. The twin row pattern improved crop structure and farmland microclimate by increasing RH and iPAR, and reducing soil and air temperatures, thus increasing grain yield. These results indicated that a twin row pattern effectively improved grain yield at I0. On the basis of iPAR, WP and grain yield, it was concluded that a twin row pattern combined with an I90 irrigation treatment provided optimal cropping conditions for the North China plain.

As the strong thermal effect in the surface, intense pulsed ion beam (IPIB) has been extensively used in material surface modification. The ablation is an important part in the interaction process between IPIB and material. In order to investigate the ablation mechanism, combined with IPIB dynamic energy spectrum and infrared imaging diagnostic results, a two-dimensional axisymmetric heat conduction model considering the effect of ablated material was constructed to describe the ablation process and calculate the lost mass of the targets. The influences of beam parameters and ablated matter on the ablation rate were discussed. The experimental and simulative results of ablation threshold and mass were compared.

As a kind of flash heat source, intense pulsed ion beam (IPIB) can be used for material surface modification. The ablation effect has important influence on interaction between IPIB and material. Therefore, the understanding of ablation mechanism is of great significance to IPIB application. In this work, pure zinc targets were irradiated and ablated by IPIB. In the ablation process under the different ion beam energy densities, the ablation products were collected by a monocrystalline silicon substrate. By analyzing the ablation products with scanning electron microscope and energy-dispersive spectrometer, the surface morphology, and the spatial distribution of ablation products quantity were obtained. The results are useful for clearing the ablation process and the influence of beam parameter on the ablation effect.

As the energy spread of intense pulsed electron beams (IPEB) strongly influences the irradiation effects, it has been of great importance to characterize the IPEB energy spectrum. With the combination of Child–Langmuir law and Monte Carlo simulation, the IPEB energy spectrum has been obtained in this work by transformation from the accelerating voltage applied to the diode. To verify the accuracy of this simple algorithm, a magnetic spectrometer with an imaging plate was designed to test the IPEB energy spectrum. The measurement was completed with IPEB generated by explosive emission electron diode, the pulse duration, maximum electron energy, total beam current being 80 ns, 450 keV, and 1 kA, respectively. The results verified the reliability of the above analysis method for energy spectrum, which can avoid intercepting the beam, and at the same time significantly improved the energy resolution. Some calculation and experimental details are discussed in this paper.

A new approach is proposed to analyze Bremsstrahlung X-rays that are emitted from laser-produced plasmas (LPP) and are measured by a stack type spectrometer. This new method is based on a spectral tomographic reconstruction concept with the variational principle for optimization, without referring to the electron energy distribution of a plasma. This approach is applied to the analysis of some experimental data obtained at a few major laser facilities to demonstrate the applicability of the method. Slope temperatures of X-rays from LPP are determined with a two-temperature model, showing different spectral characteristics of X-rays depending on laser properties used in the experiments.

Twenty Small Tailed Han (STH) and 20 Ujumqin (UJU) ewes naturally infected with gastrointestinal nematodes were randomly assigned to one of four treatments arranged in a 2 × 2 factorial design, receiving anthelmintic treatment (AT) or non-anthelmintic treatment (NonAT) prior to lambing. After lambing, the effects of AT on feed intake, digestion and milk yield in ewes, and the growth rates of lambs fed their mother's milk were assessed for 28 days. Faecal samples were collected to determine faecal egg counts (FECs), milk was collected to measure milk yield and ewes and lambs were weighed to quantify daily body weight change. The results showed that AT significantly increased ewe dry matter intake (2411 g/d for AT and 2209 g/d for NonAT) and decreased FECs (50 eggs/g for AT and 2655 eggs/g for NonAT). All ewes lost weight after lambing, but body weight loss in the AT (43 g/d) was significantly less than in NonAT (84 g/d), and STH ewes (70 g/d) lost more weight than UJU ewes (58 g/d). Anthelmintic-treated ewes produced more milk for their lambs to consume. However, the extent of these positive effects of AT differed between STH and UJU ewes. The average daily body weight gain of lambs in AT was higher than those in NonAT. In conclusion, effective AT in ewes before lambing benefits subsequent lactation in ewes and growth rate in lambs.

In this paper, a new optimisation method incorporating lamination parameters and a guide-based blending model is proposed. Lamination parameters for a guide laminate and ply number of each panel are employed as design variables for optimisation with a parallel real-coded genetic algorithm incorporating structure behaviour and manufacturing constraints. During the optimisation process, with a form of least squares fitting adopted, another genetic algorithm is used to obtain the guide stacking sequence of the guide laminate from the guide lamination parameters, and then the laminate configurations of each panel are obtained from the guide stacking sequence and number of plies for each panel. The proposed framework is demonstrated via design of an 18-panel horseshoe configuration, where each panel is optimised individually with a buckling constraint. Numerical results indicate that the present algorithm is capable of obtaining fully blended designs.