We studied the influence of Pt, Co and MnIr layer on the exchange bias field HE and coercive field HC in perpendicular exchange-biased Pt/Co3/MnIr multilayers by magneto-optical Kerr effect. As the ...thickness of the Pt layer increases, the perpendicular magnetic anisotropy constant Ku first increases and then reaches to saturation, which is resulted from the competition between perpendicular anisotropy and interfacial short-range interaction. The saturation damping constant α0 of the sample increases from about 0.062 to 0.122 when the Pt thickness increases from 0.5 nm to 1.5 nm. However, α0 increases with the decrease of Co thickness. We attributed both of these mainly to spin pumping effect.
Energetic electron and ion (electrons: 30 keV to 500 keV, protons: 30 keV to 1.5 MeV) flux variations associated with ultralow frequency (ULF) waves in the dayside magnetosphere were observed during ...the CLUSTER's perigee pass near 0900 MLT on Oct. 31, 2003. The ULF modulation terminated where higher frequency fluctuations appeared, as the CLUSTER spacecraft entered the plasmasphere boundary layer (PBL) where the plasma ion density was elevated. In the region from L ∼ 5.0 to 10, the periods of the ion flux modulation and the electron flux modulation are same but out‐of‐phase. The observed magnetic ULF pulsations are dominated by the toroidal mode, along with a relatively weaker poloidal wave. A 90° phase shift between the radial electric field and the azimuthal magnetic field indicates that dominating toroidal standing waves observed at the southern hemisphere are a fundamental harmonic. This study shows that the modulation of the electron flux is dominated by the toroidal mode in the region of L > 7.5. The observations made in this analysis suggest the excitation of the energetic electron drift resonance at around 127 keV.
The fatigue damage of a long deepwater riser undergoing in-line and cross-flow vortex-induced vibration (VIV) in deepwater is numerically studied using pseudo-excitation method (PEM) in present ...paper. For evaluating the fluid–structure interaction problem of vortex-induced vibration of deepwater riser at high Reynolds number, the strip theory is employed in this paper, and the discrete vortex method (DVM) is used to calculate the VIV of each strip to obtain the load spectrum as the pseudo-excitation, while the finite volume method (FVM) is employed to evaluate the structure dynamics of a deepwater riser. The VIV is considered as a stationary random process. The response of riser to vortex induced excitation is calculated using pseudo-excitation method. The DVM model and pseudo-excitation method are both validated by comparing their numerical results with experiments. The fatigue damage of one deepwater riser is evaluated based on the Palmgren–Miner Rule.
•The fatigue damage of a deepwater riser from in-line and cross-flow VIV is studied using PEM.•The DVM is used to calculate the vibration of 2D cylindrical strip in uniform flow.•The FVM is employed for evaluating the structure dynamics.•The in-line VIV is suggested to be considered in the design stage of riser.•PEM is proved to be efficient and accurate to estimate the fatigue damage of a deepwater riser.
Many important agronomic traits in crop plants, including stress tolerance, are complex traits controlled by quantitative trait loci (QTLs). Isolation of these QTLs holds great promise to improve ...world agriculture but is a challenging task. We previously mapped a rice QTL, SKC1, that maintained K+ homeostasis in the salt-tolerant variety under salt stress, consistent with the earlier finding that K+ homeostasis is important in salt tolerance. To understand the molecular basis of this QTL, we isolated the SKC1 gene by map-based cloning and found that it encoded a member of HKT-type transporters. SKC1 is preferentially expressed in the parenchyma cells surrounding the xylem vessels. Voltage-clamp analysis showed that SKC1 protein functions as a Na+-selective transporter. Physiological analysis suggested that SKC1 is involved in regulating K+/Na+ homeostasis under salt stress, providing a potential tool for improving salt tolerance in crops.
An improved microchannel heat sink with the sinusoidal wavy sidewall (SIN) is designed and fabricated by MEMS technique. The synchronous optical measurement system is established. The flow and heat ...transfer performance in SIN microchannels is experimentally studied using acetone as the working fluid. At mass fluxes of 251 kg/(m2·s)–423 kg/(m2·s) and heat fluxes of 0 kW/m2–601 kW/m2, the pressure drops, boiling curves, and heat transfer coefficient are investigated and analyzed. The temperatures, pressure drops, and corresponding flow patterns in the stable state are emphatically examined. The experimental results show that, a continuously developing liquid film always exists near the sidewall, which not only timely supplies the liquid for nucleation tending to occur in the corner regions, but effectively prevents the microchannel dry-out. Consequently, the premature onset of nucleate boiling (ONB), the delayed critical heat flux (CHF), and about 100% enhancement of heat transfer coefficient can be achieved with SIN microchannels compared to the traditional rectangular (R) microchannels. In the stable state, all the dominant flow patterns at different positions are almost fixed, which result in stable heat transfer enhancement. The flow pattern transitions between single liquid/bubbly flow, bubbly/slug flow, bubbly/annular flow are observed at the channel midstream in the low/medium/high heat flux, respectively. It is noteworthy that all of the dominant flow patterns at the channel downstream are not vapor flow but annular flow with thin and continuous liquid film. In addition, the flow boiling instabilities characterized by the temperatures and pressure drops with obvious fluctuations are also illustrated.
We previously demonstrated that a 31-bp nucleotide sequence located upstream of the rice Wx gene played an important role in its expression. We further showed that this cis-acting regulator interacts ...with nuclear proteins extracted from developing rice endosperm. We used the 31-bp sequence as bait in a yeast one-hybrid system to isolate several cDNA clones from a rice cDNA expression library. One of these cDNAs encodes a MYC protein, designated OsBP-5, which is 335 amino acids long and contains a putative basic helix-loop-helix-ZIP DNA-binding domain. This domain exhibits 50% amino acid sequence identity with the R/B proteins that regulate the expression of genes involved in anthocyanin biosynthesis in plants. The results of electrophoretic mobility shift assays (EMSAs) and Southwestern gel blots indicate that this protein binds specifically to the CAACGTG motif within the 31-bp sequence. However, by itself, the OsBP-5 protein is unable to trans-activate a lacZ reporter gene controlled by the 31-bp sequence when tested in a yeast expression system. Interestingly, OsBP-5 can trans-activate this reporter gene when another protein, OsEBP-89, a member of the EREBP family of transcription factors, is present. Furthermore, in vitro pull-down experiments show that a protein isolated from developing rice endosperm interacts with the OsBP-5 protein, and Western blots confirm that the interacting protein is OsEBP-89. The formation of a supershift band in EMSAs also indicates that two proteins interact with each other. Interference of OsBP-5 gene expression by double-stranded RNA reduces the amylose content in mature seed of transgenic rice plants but has no visible effect on their phenotype. These results suggest that the OsBP-5 and OsEBP-89 proteins act synergistically, perhaps as a heterodimer, to regulate the transcription of the rice Wx gene.
Mutation analysis of unrelated families with Duchenne/Becker muscular dystrophy (DMD/BMD) was performed to investigate the characteristic of DMD gene mutation, especially the distribution pattern of ...point mutation of DMD gene in Chinese population.
A total of 433 unrelated DMD/BMD families were collected at the Center of Prenatal Diagnosis of the First Affiliated Hospital of Zhengzhou University from March 2010 to December 2014. The deletions or duplications in 79 exons of DMD gene were screened using multiplex ligation-dependent probe amplification (MLPA). Any single-exon deletion detected by MLPA was further validated by PCR amplification. In the 117 unrelated Chinese families in which large-scale deletions and duplications had been excluded by MLPA, the point mutation in 79 exons of DMD gene were tested in the propositus using next-generation sequencing (NGS), and further verified the point mutation using Sanger sequencing.
In the 433 unrelated DMD/BMD families, 316 families with DMD deletions/duplications
Summary
We have previously reported that three distinct patterns of waxy (Wx) gene transcript accumulation were present in 31 rice cultivars. The cultivars with high amylose content (group I) contain ...a 2.3 kb mature Wx mRNA, cultivars with intermediate amylose content (group II) produce both a 3.3 kb Wx pre‐mRNA, which contains intron 1, and the 2.3 kb Wx mature mRNA, and cultivars with no amylose (group III) accumulate only the 3.3 kb Wx pre‐mRNA. Analyses of the cDNAs reveals that four splice donor sites and three splice acceptor sites in intron 1 give rise to six splicing patterns in 2.3 kb Wx mRNA of group II cultivars. In addition, aberrant intron 1 excision causes either deletion of 4 or 5 nucleotides, or addition of 7 and 13 nucleotides at the junction of exon 1 and exon 2 of the 2.3 kb mRNA. In contrast, only one normal splicing pattern (one splice donor site and one splice acceptor site) was found in the 2.3 kb mRNA of group I cultivars. Nucleotide sequences of the Wx intron 1 in group I and group II cultivars differ by 16 individual bases. We suggest that these deletions or additions contribute to inefficient splicing of intron 1 from the 3.3 kb Wx pre‐mRNA, as well as an aberrant splicing of the Wx intron 1 to produce the 2.3 kb mRNA with a heterogeneous 5′ untranslated region (5′‐UTR). As a consequence, the total amount of translatable Wx mRNA, and therefore the Wx protein and amylose content, are reduced in the group II cultivars compared with the group I cultivars.
In this work, the superposition principle is introduced to model the dynamic micro tensile strength of diamond crystal in different directions and on any plane. Subsequently, a novel anti-wear ...strength evaluation factor is proposed to evaluate the wear resistance anisotropy of multifaceted diamond Berkovich indenter, which is directly calculated in terms of the distribution of dynamic micro tensile strength on the pyramid faces. Be consistent with theoretical prediction, the higher is the anti-wear strength evaluation factor on the indenter edge or indenter tip, the better is the wear resistance. Finally, six diamond Berkovich indenters with different crystalline orientations on the pyramid faces are employed to perform the wear tests on the hard sapphire substrates. The results indicate that the experimental observations have a good consistency with the theoretical predictions, which confirms that the newly developed anti-wear strength evaluation factor is effective.
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