111 research outputs found
Magnetic Borophenes from an Evolutionary Search
A computational methodology based on ab initio evolutionary algorithms and spin-polarized density functional theory was developed to predict two-dimensional magnetic materials. Its application to a model system borophene reveals an unexpected rich magnetism and polymorphism. A metastable borophene with nonzero thickness is an antiferromagnetic semiconductor from first-principles calculations, and can be further tuned into a half-metal by finite electron doping. In this borophene, the buckling and coupling among three atomic layers are not only responsible for magnetism, but also result in an out-of-plane negative Poisson\u27s ratio under uniaxial tension, making it the first elemental material possessing auxetic and magnetic properties simultaneously
Early selection of \u3cem\u3ebZIP73\u3c/em\u3e facilitated adaptation of \u3cem\u3ejaponica\u3c/em\u3e rice to cold climates
Cold stress is a major factor limiting production and geographic distribution of rice (Oryza sativa). Although the growth range of japonica subspecies has expanded northward compared to modern wild rice (O. rufipogon), the molecular basis of the adaptation remains unclear. Here we report bZIP73, a bZIP transcription factor-coding gene with only one functional polymorphism (+511 G\u3eA) between the two subspecies japonica and indica, may have facilitated japonica adaptation to cold climates. We show the japonica version of bZIP73 (bZIP73Jap) interacts with bZIP71 and modulates ABA levels and ROS homeostasis. Evolutionary and population genetic analyses suggest bZIP73 has undergone balancing selection; the bZIP73Jap allele has firstly selected from standing variations in wild rice and likely facilitated cold climate adaptation during initial japonica domestication, while the indica allele bZIP73Ind was subsequently selected for reasons that remain unclear. Our findings reveal early selection of bZIP73Jap may have facilitated climate adaptation of primitive rice germplasms
Study of Peeling of Single Crystal Silicon by Intense Pulsed Ion Beam
The surface peeling process induced by intense
pulsed ion beam (IPIB) irradiation was studied.
Single crystal silicon specimens were treated by
IPIB with accelerating voltage of 350 kV current
density of 130 A/cm2. It is observed that
under smaller numbers of IPIB shots, the surface
may undergo obvious melting and evaporation..
The roles of SMYD4 in epigenetic regulation of cardiac development in zebrafish
SMYD4 belongs to a family of lysine methyltransferases. We analyzed the role of smyd4 in zebrafish development by generating a smyd4 mutant zebrafish line (smyd4L544Efs*1) using the CRISPR/Cas9 technology. The maternal and zygotic smyd4L544Efs*1 mutants demonstrated severe cardiac malformations, including defects in left-right patterning and looping and hypoplastic ventricles, suggesting that smyd4 was critical for heart development. Importantly, we identified two rare SMYD4 genetic variants in a 208-patient cohort with congenital heart defects. Both biochemical and functional analyses indicated that SMYD4(G345D) was pathogenic. Our data suggested that smyd4 functions as a histone methyltransferase and, by interacting with HDAC1, also serves as a potential modulator for histone acetylation. Transcriptome and bioinformatics analyses of smyd4L544Efs*1 and wild-type developing hearts suggested that smyd4 is a key epigenetic regulator involved in regulating endoplasmic reticulum-mediated protein processing and several important metabolic pathways in developing zebrafish hearts
Study of Peeling of Single Crystal Silicon by Intense Pulsed Ion Beam
The surface peeling process induced by intense
pulsed ion beam (IPIB) irradiation was studied.
Single crystal silicon specimens were treated by
IPIB with accelerating voltage of 350 kV current
density of 130 A/cm2. It is observed that
under smaller numbers of IPIB shots, the surface
may undergo obvious melting and evaporation..
Study on Ablation Products of Zinc by Intense Pulsed Ion Beam Irradiation
As a kind of flash heat source, intense pulse ion
beam 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..
Study of the intense pulsed electron beam energy spectrum from BIPPAB-450
Intense pulsed particle beams have been
widely used and studied as an effective method
for material surface modification in the past
several decades. Beihang Intense Pulsed PArticle
Beams 450 accelerator (BIPPAB-450) can
produce Intense Pulsed Ion Beams (IPIB) and
Electron Beams (IPEB) in two modes with different
Magnetically Insulated Diodes (MID).
For IPEB, the pulse duration, accelerating voltage,
total beam current are 100ns, up to 450keV
and 3kA, respectively..
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