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921.
Dielectric properties, electrical modulus and current transport mechanisms
of Au/ZnO/n-Si structures
Au/Zn O/n-Si(MIS)structures were fabricated by using the RF sputtering method and their complex dielectric constant(ε~*=ε’-jε’’),electric modulus(M~*=M′+j M’’)and electrical conductivity(σ=σ_(dc)+σ_(ac))values were investigated as a function of frequency(0.7 k Hz-1 MHz)and voltage(-6–(+6 V))by capacitance-voltage(C-V)and conductance-voltage(G/ω-V)measurements to get more information on the conduction mechanisms and formation of barrier height between Au and n-Si.The lnσ-Lnf plots have two different regions corresponding to low-intermediate and high frequencies.Such behavior of lnσ-lnf plots shows that the existence of two different conduction mechanisms(CMs)at low-intermediate and high frequencies.Moreover,the reverse bias saturation current(I_o),ideality factor(n),barrier height(Φ_(Bo))were determined from the forward bias I-V data and they were found as a strong function of temperature.The value of n especially at low temperature is considerably higher than unity.The values ofΦ_(B0)and standard deviation(σ_s)were found from the intercept and slope ofΦ_(Bo)-q/2k T plots as 0.551 e V and 0.075 V for the region I(80–220 K)and 1.126 e V and 0.053 V for the region II(220–400 K),respectively.The values ofΦ_(Bo)and effective Richardson constant(A~*)were found from slope and intercept of activation energy plots as 0.564 e V and 101.084 Acm~(-2)K~(-2)for the region I and 1.136 e V and41.87 Acm~(-2)K~(-2)for the region II,respectively.These results confirm that the current-voltage-temperature(I-V-T)characteristics of the fabricated Au/Zn O/n-Si SBDs can satisfactorily be explained on the basis of TE theory with double GD of the BHs. 相似文献
922.
区域环境资源是区域经济发展的物质基础,但区域环境条件是区域经济发展的前提和必要条件。区域环境条件直接影响到区域的开发程度和区域经济的发展水平,直接影响到区域经济的空间结构和空间布局。也就可以说,区域环境条件是创造区域经济发展的潜在能力,实现区域经济飞跃根本。 相似文献
923.
主要对移动式排土机的动态特性进行了测试与分析.结果证明该设备安全系数过大使其结构庞大、机动性差.文中涉及的应力测试与分析及有限元计算结果,为今后移动式排土机结构的优化设计和改进工作提供了科学依据. 相似文献
924.
Hf isotopic compositions of the standard zircons for U-Pb dating 总被引:48,自引:4,他引:48
XU Ping WU Fuyuan XIE Liewen & YANG Yueheng Institute of Geology Geophysics Chinese Academy of Sciences Beijing China Correspondence should be addressed to Wu Fuyuan 《科学通报(英文版)》2004,49(15):1642-1648
Zircon, a common accessory mineral in various kindsof rocks, is an important subject for U-Pb isotopic dating.With requirements for high spatial resolution with highprecision and accuracy, SHRIMP (Sensitive High Resolu-tion Ion Micro Probe) and LA-ICPMS (Laser AblationInductively Coupled Plasma Mass Spectrometry) nowserve as the important tools in zircon U-Pb dating. Sinceboth methods need standard zircon for external age cali-bration, an ideal standard zircon is critical for obtai… 相似文献
925.
Characterization of murine non-adherent bone marrow cells leading to recovery of endogenous hematopoiesis 总被引:1,自引:1,他引:0
Stephan Fricke Christian Fricke Christopher Oelkrug Nadja Hilger Uta Sch?nfelder Manja Kamprad J?rg Lehmann Johannes Boltze Frank Emmrich Ulrich Sack 《Cellular and molecular life sciences : CMLS》2010,67(23):4095-4106
Non-adherent bone marrow-derived cells (NA-BMCs) are a mixed cell population that can give rise to multiple mesenchymal phenotypes
and that facilitates hematopoietic recovery. We characterized NA-BMCs by flow cytometry, fibroblast colony-forming units (CFU-f),
real-time PCR, and in in vivo experiments. In comparison to adherent cells, NA-BMCs expressed high levels of CD11b+ and CD90+ within the CD45+ cell fraction. CFU-f were significantly declining over the cultivation period, but NA-BMCs were still able to form CFU-f
after 5 days. Gene expression analysis of allogeneic NA-BMCs compared to bone marrow (BM) indicates that NA-BMCs contain stromal,
mesenchymal, endothelial cells and monocytes, but less osteoid, lymphoid, and erythroid cells, and hematopoietic stem cells.
Histopathological data and analysis of weight showed an excellent recovery and organ repair of lethally irradiated mice after
NA-BMC transplantation with a normal composition of the BM. 相似文献
926.
Gerardo?Carranza Raquel?Casta?o Mónica?L.?Fanarraga Juan?Carlos?Villegas Jo?o?Gon?alves Jesus?Avila Marco?Marenchino Ramón?Campos-Olivas Guillermo?Montoya Juan?Carlos?ZabalaEmail author 《Cellular and molecular life sciences : CMLS》2013,70(2):357-371
Tubulin cofactors (TBCs) participate in the folding, dimerization, and dissociation pathways of the tubulin dimer. Among them, TBCB and TBCE are two CAP-Gly domain-containing proteins that together efficiently interact with and dissociate the tubulin dimer. In the study reported here we showed that TBCB localizes at spindle and midzone microtubules during mitosis. Furthermore, the motif DEI/M-COO? present in TBCB, which is similar to the EEY/F-COO? element characteristic of EB proteins, CLIP-170, and α-tubulin, is required for TBCE–TBCB heterodimer formation and thus for tubulin dimer dissociation. This motif is responsible for TBCB autoinhibition, and our analysis suggests that TBCB is a monomer in solution. Mutants of TBCB lacking this motif are derepressed and induce microtubule depolymerization through an interaction with EB1 associated with microtubule tips. TBCB is also able to bind to the chaperonin complex CCT containing α-tubulin, suggesting that it could escort tubulin to facilitate its folding and dimerization, recycling or degradation. 相似文献
927.
Todd JA Walker NM Cooper JD Smyth DJ Downes K Plagnol V Bailey R Nejentsev S Field SF Payne F Lowe CE Szeszko JS Hafler JP Zeitels L Yang JH Vella A Nutland S Stevens HE Schuilenburg H Coleman G Maisuria M Meadows W Smink LJ Healy B Burren OS Lam AA Ovington NR Allen J Adlem E Leung HT Wallace C Howson JM Guja C Ionescu-Tîrgovişte C;Genetics of Type Diabetes in Finland Simmonds MJ Heward JM Gough SC;Wellcome Trust Case Control Consortium Dunger DB Wicker LS Clayton DG 《Nature genetics》2007,39(7):857-864
The Wellcome Trust Case Control Consortium (WTCCC) primary genome-wide association (GWA) scan on seven diseases, including the multifactorial autoimmune disease type 1 diabetes (T1D), shows associations at P < 5 x 10(-7) between T1D and six chromosome regions: 12q24, 12q13, 16p13, 18p11, 12p13 and 4q27. Here, we attempted to validate these and six other top findings in 4,000 individuals with T1D, 5,000 controls and 2,997 family trios independent of the WTCCC study. We confirmed unequivocally the associations of 12q24, 12q13, 16p13 and 18p11 (P(follow-up) 相似文献
928.
极化检测是雷达目标检测的一个重要分支.在高斯杂波统计特征已知的情况下,极化白化滤波器(PWF)常被用于杂波中雷达目标的检测.假设目标的极化特性和杂波的统计特征均已知,为了利用目标的先验知识,提出了一种基于目标极化适配的检测算法,据此算法设计了极化适配检测器(PAD).PAD和PWF对低极化度高斯杂波中二面角的模拟检测结果显示,在低信杂比下,PAD算法具有较好的检测性能. 相似文献
929.
Yasmina?Manso Javier?Carrasco Gemma?Comes Gabriele?Meloni Paul?A.?Adlard Ashley?I.?Bush Milan?Va?ák Juan?HidalgoEmail author 《Cellular and molecular life sciences : CMLS》2012,69(21):3683-3700
Among the dementias, Alzheimer’s disease (AD) is the most commonly diagnosed, but there are still no effective drugs available for its treatment. It has been suggested that metallothionein-3 (MT-3) could be somehow involved in the etiology of AD, and in fact very promising results have been found in in vitro studies, but the role of MT-3 in vivo needs further analysis. In this study, we analyzed the role of MT-3 in a mouse model of AD, Tg2576 mice, which overexpress human Amyloid Precursor Protein (hAPP) with the Swedish mutation. MT-3 deficiency partially rescued the APP-induced mortality of females, and mildly affected APP-induced changes in behavior assessed in the hole-board and plus-maze tests in a gender-dependent manner. Amyloid plaque burden and/or hAPP expression were decreased in the cortex and hippocampus of MT-3-deficient females. Interestingly, exogenously administered Zn7MT-3 increased soluble Aβ40 and Aβ42 and amyloid plaques and gliosis, particularly in the cortex, and changed several behavioral traits (increased deambulation and exploration and decreased anxiety). These results highlight that the control of the endogenous production and/or action of MT-3 could represent a powerful therapeutic target in AD. 相似文献
930.
Le Chalony C Hoffschir F Gauthier LR Gross J Biard DS Boussin FD Pennaneach V 《Cellular and molecular life sciences : CMLS》2012,69(17):2933-2949
DNA ligase I (LigI) plays a central role in the joining of strand interruptions during replication and repair. In our current study, we provide evidence that DNA ligase III (LigIII) and XRCC1, which form a complex that functions in single-strand break repair, are required for the proliferation of mammalian LigI-depleted cells. We show from our data that in cells with either dysfunctional LigI activity or depleted of this enzyme, both LigIII and XRCC1 are retained on the chromatin and accumulate at replication foci. We also demonstrate that the LigI and LigIII proteins cooperate to inhibit sister chromatid exchanges but that only LigI prevents telomere sister fusions. Taken together, these results suggest that in cells with dysfunctional LigI, LigIII contributes to the ligation of replication intermediates but not to the prevention of telomeric instability. 相似文献