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751.
通过恒流电沉积的方法在柔性碳布上制备了钴离子掺杂的MnO2,其负载量达到13.8 mg/cm2。利用X射线衍射仪(X-ray diffractometer, XRD)、扫描电子显微镜(scanning electron microscope, SEM)、X射线光电子能谱(X-ray photoelectron spectrometer, XPS)和电化学工作站等对材料的结构和性能进行表征,探究了钴离子掺杂对MnO2电化学性能的影响。结果表明,当该电极与活性炭组装成液态锌离子混合电容器(zinc ion hybrid capacitors, Zn-HCs)时,Zn-HCs在2 mA/cm2的电流密度下,面积比电容高达5 883.0 mF/cm2,面积能量密度为3 154.9 μWh/cm2,与锌离子电池的能量水平相当。当该电极与活性炭组装成准固态柔性Zn-HCs时,Zn-HCs具有较好能量密度(在1 mW/cm2的功率密度下达1 351.1 μWh/cm2 )的同时具有优异的机械柔韧性,使Zn-HCs有望应用于新一代的柔性可穿戴设备。 相似文献
752.
光萼小蜡花精油的超临界CO2萃取及其GC-MS分析 总被引:1,自引:0,他引:1
利用超临界CO2萃取技术从光萼小蜡花中提取精油,通过单因素实验探讨萃取压力和萃取温度对萃取产率的影响,并采用GC-MS技术对萃取物成分进行分析,发现其主要组分为苯乙醇.通过对各组萃取精油中苯乙醇含量进行比较,初步确立利用超临界CO2萃取光萼小蜡花精油的最佳工艺参数为:萃取压力25 MPa,萃取温度55 ℃. 相似文献
753.
带有测量噪声的Ⅱ型T-S模糊建模 总被引:1,自引:0,他引:1
实际工业生产过程中,系统的数据带有测量噪声.Ⅱ型模糊集的二阶隶属度用来表征一阶隶属度的模糊度,这种模糊度的增加意味着处理不确定信息能力增加.因此,提出了一种基于Ⅱ型模糊集的T-S模糊建模方法来减少由噪声带来不确定信息的影响.首先采用改进的最小邻域算法对带有测量噪声的数据进行聚类,继而确定Ⅱ型模糊集的一阶隶属度,接着根据数据的聚类信息采用高斯混和模型得到二阶隶属度值,然后用正交最小二乘算法确定模糊模型的后件参数,最后通过仿真实验来验证该方法的有效性. 相似文献
754.
An extension of 2-D assignment approach is proposed for measurement-to-target association for improving multiple targets vector miss distance measurement accuracy. When the multiple targets move so closely, the measurements can not be fully resolved due to finite resolution. The proposed method adopts an auction algorithm to compute the feasible measurement-to-target assignment with unresolved measurements for solving this 2-D assignment problem. Computer simulation results demonstrate the effectiveness and feasibility of this method. 相似文献
755.
基于二维几何特征的微地形快速识别算法 总被引:1,自引:0,他引:1
为满足水下超声波准确、实时探测海底微地形的需要,研制出一种摆动式单波束探测系统.该系统在探测实验过程中,因出现高程奇异值而造成数字"伪"地形产生,由此提出一种基于二维几何特征的水平、斜坡和凹凸不平三种微地形模式的快速识别算法.该算法建立在现代统计分析与模糊聚类的理论基础上,具有准确性高、实时性好以及抗干扰能力强等优点;并由物理模拟实验证明,利用该算法能有效消除高程奇异值的影响,识别出来的微地形模式准确可靠,为下一步快速重构逼真的数字微地形提供了保障,能够应用于真实的海底微地形探测. 相似文献
756.
757.
Cohausz O Blenn C Malanga M Althaus FR 《Cellular and molecular life sciences : CMLS》2008,65(4):644-655
Poly(ADP-ribose) (PAR) has been identified as a DNA damage-inducible cell death signal upstream of apoptosis-inducing factor
(AIF). PAR causes the translocation of AIF from mitochondria to the nucleus and triggers cell death. In living cells, PAR
molecules are subject to dynamic changes pending on internal and external stress factors. Using RNA interference (RNAi), we
determined the roles of poly(ADP-ribose) polymerases-1 and -2 (PARP-1, PARP-2) and poly(ADP-ribose) glycohydrolase (PARG),
the key enzymes configuring PAR molecules, in cell death induced by an alkylating agent. We found that PARP-1, but not PARP-2
and PARG, contributed to alkylation-induced cell death. Likewise, AIF translocation was only affected by PARP-1. PARP-1 seems
to play a major role configuring PAR as a death signal involving AIF translocation regardless of the death pathway involved.
Received 7 November 2007; received after revision 19 December 2007; accepted 21 December 2007
O. Cohausz, C. Blenn: These two authors contributed equally to this work. 相似文献
758.
Zinc binding to peptide analogs of the structural zinc site in alcohol dehydrogenase: Implications for an entatic state 总被引:1,自引:0,他引:1
Bergman T Zhang K Palmberg C Jörnvall H Auld DS 《Cellular and molecular life sciences : CMLS》2008,65(24):4019-4027
Zinc binding to the peptide replica and analogs to residues 93–115 of horse liver alcohol dehydrogenase (ADH) was examined
by competition of the peptides and the chromophoric chelator 4-(2- pyridylazo)resorcinol for zinc and X-ray absorption fine
structure analysis of the zinc ligands. In the enzyme, zinc is coordinated by four Cys residues. In the peptide replica, zinc
is bound to three Cys and one His residue. A four-Cys zinc coordination is observed only when His is removed, leading to increased
zinc stability. ADH crystal structures reveal that the ε-amino group of the conserved residue Lys323 is within H-bond distance
of the backbone amide oxygens of residues 103, 105 and 108, likely stabilizing the zinc coordination in the enzyme. The peptide
data thus indicate structural strain and increased energy in the zinc-binding site in the protein, characteristic of an entatic
state, implying a functional nature for this zinc site.
Received 3 July 2008; received after revision 11 August 2008; accepted 1 September 2008 相似文献
759.
Muñoz U Bartolomé F Esteras N Bermejo-Pareja F Martín-Requero A 《Cellular and molecular life sciences : CMLS》2008,65(21):3507-3519
It has been proposed that neuroinflammation, among other factors, may trigger an aberrant neuronal cell cycle re-entry leading
to neuronal death. Cell cycle disturbances are also detectable in peripheral cells from Alzheimer’s disease (AD) patients.
We previously reported that the anti-inflammatory 15- deoxy-Δ12,14-prostaglandin J
2 (15d-PGJ
2) increased the cellular content of the cyclin-dependent kinase inhibitor p27, in lymphoblasts from AD patients. This work
aimed at elucidating the mechanisms of 15d-PGJ
2-induced p27 accumulation. Phosphorylation, half-life, and the nucleo-cytoplasmic traffic of p27 protein were altered by 15d-PGJ2
by mechanisms dependent on PI3K/Akt activity. 15d-PGJ
2 prevents the calmodulin-dependent Akt overactivation in AD lymphoblasts by blocking its binding to the 85-kDa regulatory
subunit of PI3K. These effects of 15d-PGJ
2 were not mimicked by 9,10-dihydro-15-deoxy-Δ12,14- prostaglandin J
2, suggesting that 15d-PGJ
2 acts independently of peroxisome proliferator-activated receptor γ activation and that the α,β-unsaturated carbonyl group
in the cyclopentenone ring of 15d-PGJ
2 is a requisite for the observed effects.
Received 14 July 2008; received after revision 2 September 2008; accepted 12 September 2008 相似文献
760.
我国城市人均医生数的统计建模与分析 总被引:5,自引:0,他引:5
侯紫燕 《系统工程理论与实践》1999,19(2):128-134
介绍拟合非对称分布数据的一种方法,然后运用这种方法建立了我国每万人医生数的分布模型,并利用这一模型分析我国城市的就医状况 相似文献