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991.
Seo JH Yoon SW Chae KH Park JK Song JH Jayaram V Lee KB Seong TY Kwon H Ahn JP 《Journal of nanoscience and nanotechnology》2012,12(2):1581-1584
AlxTi1-xN/CrN multilayer coatings were fabricated by magnetron sputtering and those hardness variations were studied by observing the crack propagation and measuring the chemical bonding state of nitrides by Ti addition. While AlN/CrN multilayer shown stair-like crack propagation, AlxTi1-xN/CrN multilayer illustrated straight crack propagation. Most interestingly, Ti addition induced more broken nitrogen bonds in the nitride multilayers, leading to the reduction of hardness. However, the hardness of Al0.25Ti0.75N/CrN multilayer, having high Ti contents, increased by the formation of many Ti-N bond again instead of Al-N bond. From these results, we found that linear crack propagation behavior was dominated by broken nitrogen bonds in the AlxTi1-xN/CrN multilayer coatings. 相似文献
992.
In this paper, a new SPICE macromodel and CMOS emulator for memristors are proposed and verified to fit to the memristor's model equation very well in the entire range of memristor's resistance from the RESET state to the SET state. Compared with the memristor's model equation, average percentage errors in the new SPICE macromodel and in the 4-bit CMOS emulator are less than 0.5% and 0.9%, respectively. In addition, the CMOS emulator for memristors which can be implemented by a CMOS circuit will be very useful to design and verify various peripheral circuits for memristor applications particularly when the memristor fabrication process is not ready. 相似文献
993.
Jung DW Lee KH Kim JH Burk D Overzet LJ Lee GS Kong SH 《Journal of nanoscience and nanotechnology》2012,12(7):5663-5668
One must control the size distribution of catalyst Fe nano-particles (NPs) very carefully if one is to have any chance of growing "super-aligned" carbon nanotube (CNT) forests which can be spun directly into yarns and pulled directly into long sheets. Control of the Fe Nps size is important during all phases, including: the catalyst deposition, annealing and forest growth. As a result, it is important to understand how NPs are affected by various experimental factors as well as how those catalyst NPs then cause the growth of the forests. This paper focuses on two key experimental factors: The as-deposited thickness of the Fe catalyst film and the use of hydrogen gas (H2) during anneal and growth. We found that the sheet resistance (Rs) of as-deposited Fe films is directly related to the average film thickness and can be used to estimate whether the films can catalyze the growth of super-aligned forests. The height of the CNT forests decrease with decreasing Rs, but only slowly. More importantly, CNTs grown on the largest and the smallest Rs films are less aligned. Instead, they are more curled and wavy due to the Fe NP dynamics. The use of Hydrogen (H2) affects the formation of Fe NPs from the as-deposited film as well as their composition during the forest growth. We find that the addition of H2 to a CNT forest growth process at 680 degrees C (C2H2/He [30/600 sccm]) increases the CNT alignment substantially. H2 can also reduce iron-oxides which otherwise would impede the formation of NPs. As a result, H2 has multiple roles: besides its chemical reactivity, H2 is important for catalyst reconstruction into NPs having a proper size distribution as well as surface density. 相似文献
994.
Shin HS Yun HJ Baek KH Ham YH Park KS Kim DP Lee GW Lee HD Lee K Do LM 《Journal of nanoscience and nanotechnology》2012,12(7):5325-5329
We used micro contact printing (micro-CP) to fabricate inverted coplanar pentacene thin film transistors (TFTs) with 1-microm channels. The patterning of micro-scale source/drain electrodes without etch process was successfully achieved using Polydimethylsiloxane (PDMS) elastomer stamp. We used the Ag nano particle ink as an electrode material, and the sheet resistance and surface roughness of the Ag electrodes were effectively reduced with the 2-step thermal annealing on a hotplate, which improved the mobility, the on-off ratio, and the subthreshold slope (SS) of the pentacene TFTs. In addition, the device annealing on a hotplate in a N2 atmosphere for 30 sec can enhance the off-current and the mobility properties of OTFTs without damaging the pentacene thin films and increase the adhesion between pentacene and dielectric layer (SiO2), which was investigated with the pentacene films phase change of the XRD spectrum after device annealing. 相似文献
995.
Jung DW Jeong JH Kim KH Kong BS Oh ES 《Journal of nanoscience and nanotechnology》2012,12(7):5435-5439
SnO2 nanoparticles were supported on ball-milled graphite (BMG) or carbon nanotubes (CNTs) using a chemical reduction method with ethylene glycol, and the electrochemical properties of the nanocomposites were evaluated as anode active materials of lithium-ion batteries. The BMG and CNTs contributed to an increase in both the capacity enhancement and cyclic stability compared to that of commercial graphite. In particular, the mixture electrode of SnO2/BMG:SnO2/CNT = 3:1 (in weight ratio) showed higher performance in the reversible capacity and cyclic stability than did the SnO2/BMG and SnO2/CNT electrodes. This might be resulted from the network formation for excellent electronic path by CNT distributed on SnO2/BMG composites. 相似文献
996.
Lee SJ Koo JR Shin H Han WK Lee KH Yoon SS Kim YK 《Journal of nanoscience and nanotechnology》2012,12(5):4154-4158
We have demonstrated lower driving voltage and efficient blue phosphorescent organic light emitting diodes (PHOLEDs) using iridium(III) bis[(4,6-di-fluoropheny)-pyridinato-N,C2] picolinate (Flrpic) doped in new host material 9-(4-(triphenylsilyl)phenyl)-9H-carbazole (SPC) and 2,2',2"-(1,3,5-benzenetryl)tris(1-phenyl)-1H-benzimidazol (TPBi) as double-emitting layer (D-EML) system. The D-EML was employed to have good electron transportability and exciton confinement. Additionally, we fabricated white organic light-emitting diode (WOLED) using a phosphorescent red emitter; bis(2-phenylquinolinato)-acetylacetonate iridium III (Ir(pq)2acac) doped in SPC and TPBi as D-EML. The properties of white device exhibited a maximum luminous efficiency of 19.03 cd/A, a maximum external quantum efficiency of 9.91%, and a maximum power efficiency of 12.30 lm/W. It also showed white emission with CIE(x,y) coordinates of (x = 0.38, y = 0.37) at 8 V. 相似文献
997.
对桥面裂缝病害进行了分析,从设计、施工、运营等多方面对桥面的裂缝病害原因进行了论述,并对有效的预防措施进行了研究,提出病害处理方法,以期达到良好的效果,解决公路桥面裂缝病害问题。 相似文献
998.
根据对新世纪居住水平的预测,提新世纪城镇住宅建设的10年递推原则”及核心家庭住宅建设标准,分析了核心家庭在其生命周期内对主要居室的需求数量,根据近年来在天津,石家庄,太原等城市的住宅实态调查结果,归纳了新世纪核心住宅的需要特点及设计要点,并在此基础上做了典型平面套型设计。 相似文献
999.
该研究以采集的河南南阳魔芋种植土壤样品为试验材料,通过富集培养、测定产β-甘露聚糖酶酶活力,分离筛选高产β-甘露聚糖酶的菌株,并通过形态观察、内转录间隔区(ITS)基因和β-微管蛋白基因BenA序列分析对其进行菌种鉴定。结果表明,筛选得到一株高产β-甘露聚糖酶真菌菌株HKS016,其β-甘露聚糖酶酶活力为2.67 U/mL,该菌株被鉴定为黑曲霉(Aspergillus niger),保藏于中国普通微生物学菌种保藏中心(CGMCC),保藏编号为CGMCC No.22413。 相似文献
1000.
Lee JS Su KH Lin JC Chuang YT Chueh HS Liu RS Wang SJ Chen JC 《Computer methods and programs in biomedicine》2008,92(3):299-304
The term input function usually refers to the tracer plasma time activity curve (pTAC), which is necessary for quantitative positron emission tomography (PET) studies. The purpose of this study was to acquire the pTAC by independent component analysis (ICA) estimation from the whole blood time activity curve (wTAC) using a novel method, namely the FDG blood-cell-two-compartment model (BCM). This approach was compared to a number of published models, including linear haematocrit (HCT) correction, non-linear HCT correction and two-exponential correction. The results of this study show that the normalized root mean square error (NRMSE) and the error of the area under curve (EAUC) for the BCM estimate of the pTAC were the smallest. Compartmental and graphic analyses were used to estimate the metabolic rate of the FDG (MR(FDG)). The percentage error for the MR(FDG) (PE(MRFDG)) was estimated from the BCM corrected pTAC and this was also the smallest. It is concluded that the BCM is a better choice when transferring wTAC into pTAC for quantification. 相似文献