200 research outputs found
Effect of Different Minority Carrier Lifetime of Multicrystalline Wafer on Solar Cell Performance
In this article, a study of the effect of different minority carrier lifetime (τ) of wafers on solar cell performance in a conventional industrial production line has been carried out. The results clearly showed that the ultimate efficiency of the solar cells made by wafers of 1μs <τ<1.2μs and 1.2μs <τ<1.5μs is much higher than that of solar cells made by wafers of τ<1μs. The gap of both is about 0.38%–0.53%. Differently, there is no significant difference between wafers of 1μs<τ<1.2μs and 1.2μs <τ<1.5μs. The results obtained are useful when the solar cell companies establish original wafers test standard in industry
Finite groups with X-quasipermutable Sylow subgroups
Let H ≤ E and X be subgroups of a finite group G. Then we say that H is X-quasipermutable (XS-quasipermutable, respectively) in E provided that G has a subgroup B such that E = NE(H)B and H X-permutes with B and with all subgroups (with all Sylow subgroups, respectively) V of B such that (|H|, |V |) = 1. We analyze the influence of X-quasipermutable and XS-quasipermutable subgroups on the structure of G. In particular, it is proved that if every Sylow subgroup P of G is F(G)-quasipermutable in its normal closure PG in G, then G is supersoluble.Нехай H ≤ E i X — пiдгрупи скiнченної групи G. Тодi говорять, що H є X-квазiпереставною (XS-квазiпереставною, вiдповiдно) в E, якщо G мiстить таку пiдгрупу B, що E = NE(H)B i H є X-переставною з B i з усiма пiдгрупами (з усiма силовськими пiдгрупами, вiдповiдно) V з B такими, що (|H|, |V |) = 1. У данiй роботi проаналiзовано вплив X-квазiпереставних i XS-квазiпереставних пiдгруп на будову G. Зокрема доведено, що якщо кожна Силовська пiдгрупа P iз G F(G)-квазiпереставна в його нормальному замиканнi PG в G, то G є надрозв’язною
Estabilidad de varios tipos de comunidad en ecosistemas de dunas en el noreste de China
The stability of artificial, sand-binding communities has not yet fully studied. A
similarity index was developed to evaluate the stability of artificial communities in
shifting and semi-fixed sand dunes. This similarity index consisted of 8 indicators (i.e.,
vegetation cover, Shannon-Wiener Index, biomass, organic matter, Total N, available P
and K, and sand particle ratio). The relative weight of these indicators was obtained
using an analytic hierarchy process (AHP) method. Stability was compared on
Artemisia halodendron Turczaninow ex Besser, Bull communities in shifting and semifixed
sand dunes, and of Caragana microphylla Lam. communities with different planting
ages. The similarity indexes of the A. halodendron communities were 0.24 and 0.54 in
shifting and semi-fixed sand dunes, respectively. The peak stability of C. microphylla
communities was 0.55, and it was reached when these communities were 20-year-old.
It is suggested that A. halodendron communities should be planted preferentially in
semi-fixed to moving sand dunes. Furthermore, the planting age of artificial communities
should be included in planting programs. This study improved the understanding
of some mechanisms contributing to maintain community stability, and is critical for
guiding the artificial planting in sand dunes.La estabilidad de comunidades artificiales que contribuyen a la fijación de suelos
arenosos no se ha estudiado completamente. Se desarrolló un índice de similitud para
evaluar la estabilidad de comunidades artificiales en dunas móviles y fijadas medianamente.
Este índice de similitud consistió de 8 indicadores (cobertura vegetal, índice
de Shannon-Wiener, biomasa, materia orgánica, N total, P y K disponibles, y relación
de partículas de arena). La importancia relativa de estos indicadores se obtuvo utilizando
un método de procesamiento jerárquico analítico (AHP). Se comparó la estabilidad
de comunidades de Artemisia halodendron Turczaninow ex Besser, Bull en dunas
móviles y fijadas medianamente, y la de comunidades de Caragana microphylla Lam.
de diferentes edades de plantación. Los índices de similitud de las comunidades de
A. halodendron fueron 0,24 y 0,54 en dunas móviles y fijadas medianamente, respectivamente.
La estabilidad máxima de las comunidades de C. microphylla fue 0,55, la que
se obtuvo cuando dichas comunidades alcanzaron 20 años de edad. Se sugiere que las
comunidades de A. halodendron se deberían plantar preferencialmente en dunas fijadas
medianamente a móviles. Además, la edad de plantación de las comunidades artificiales
se debería incluir en programas de plantación. Este estudio mejoró el entendimiento de
algunos mecanismos que contribuyen a mantener la estabilidad de las comunidades, y
es crítico para guiar la plantación artificial en áreas de dunas.Fil: Tang, Yi.Fil: Li, Xiaolan.Fil: Wu, Jinhua.Fil: Busso, Carlos Alberto
On S-quasinormally embedded subgroups of finite groups
Let G be a finite group. A subgroup A is called:1) S-quasinormal in G if A is permutable with all Sylow subgroups in G 2) S-quasinormally embedded in G if every Sylow subgroup of A is a Sylow subgroup of some S-quasinormal subgroup of G. Let BseG be the subgroup generated by all the subgroups of B which are S-quasinormally embedded in G. A subgroup B is called SE-supplemented in G if there exists a subgroup T such that G = BT and B ∩ T ≤ BseG. The main result of the paper is the following
Gastrodin ameliorates synaptic impairment, mitochondrial dysfunction and oxidative stress in N2a/APP cells
Alzheimer's disease is characterized by abnormal β-amyloid and tau accumulation, mitochondrial dysfunction, oxidative stress, and synaptic dysfunction. Here, we aimed to assess the mechanisms and signalling pathways in the neuroprotective effect of gastrodin, a phenolic glycoside, on murine neuroblastoma N2a cells expressing human Swedish mutant APP (N2a/APP). We found that gastrodin increased the levels of presynaptic-SNAP, synaptophysin, and postsynaptic-PSD95 and reduced phospho-tau Ser396, APP and Aβ1-42 levels in N2a/APP cells. Gastrodin treatment reduced reactive oxygen species generation, lipid peroxidation, mitochondrial fragmentation and DNA oxidation; restored mitochondrial membrane potential and intracellular ATP production. Upregulated phospho-GSK-3β and reduced phospho-ERK and phospho-JNK were involved in the protective effect of gastrodin. In conclusion, we demonstrated the neuroprotective effect of gastrodin in the N2a/APP cell line by ameliorating the impairment on synaptic and mitochondrial function, reducing tau phosphorylation, Aβ1-42 levels as well as reactive oxygen species generation. These results provide new mechanistic insights into the potential effect of gastrodin in the treatment of Alzheimer’s disease
Global Mapping of H3K4me1 and H3K4me3 Reveals the Chromatin State-Based Cell Type-Specific Gene Regulation in Human Treg Cells
Regulatory T cells (Treg) contribute to the crucial immunological processes of self-tolerance and immune homeostasis. Genomic mechanisms that regulate cell fate decisions leading to Treg or conventional T cells (Tconv) lineages and those underlying Treg function remain to be fully elucidated, especially at the histone modification level. We generated high-resolution genome-wide distribution maps of monomethylated histone H3 lysine 4 (H3K4me1) and trimethylated H3K4 (H3K4me3) in human CD4+CD25+FOXP3+ Tregs and CD4+CD25+FOXP3− activated (a)Tconv cells by DNA sequencing-by-synthesis. 2115 H3K4me3 regions corresponded to proximal promoters; in Tregs, the genes associated with these regions included the master regulator FOXP3 and the chemokine (C-C motif) receptor 7 (CCR7). 41024 Treg-specific H3K4me1 regions were identified. The majority of the H3K4me1 regions differing between Treg and aTconv cells were located at promoter-distal sites, and in vitro reporter gene assays were used to evaluate and identify novel enhancer activity. We provide for the first time a comprehensive genome-wide dataset of lineage-specific H3K4me1 and H3K4me3 patterns in Treg and aTconv cells, which may control cell type-specific gene regulation. This basic principle is likely not restricted to the two closely-related T cell populations, but may apply generally to somatic cell lineages in adult organisms
- …