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81.
Interdiffusion in the Fe2O3-TiO2 system was investigated by the diffusion couple method in the temperature range of 1323 to 1473 K. The diffusion concentration curves of Ti4+ cations were obtained by electron probe microanalysis, according to which the Boltzmann-Matano method optimized by Broeder was used to calculate the interdiffusion coefficients. The interdiffusion coefficients almost increased linearly with the mole fraction of Ti4+ cations increasing, and they were in the range of 10?12–10?11cm2·s?1. The increase of temperature could also lead to the increase of the interdiffusion coefficients at a constant concentration of Ti4+ cations. It was also found that the thickness growth of the diffusion layer obeyed the parabolic rate law. 相似文献
82.
Ben-Chaung Wang Fang-Yi Chou Yung-Jaan Lee 《Systemic Practice and Action Research》2010,23(2):157-172
Chung-Sheng Community in Taoyuan City, Taiwan is a typical urban community. By adopting participatory action research, this study examines resident awareness regarding the feasibility of transforming Chung-Sheng Community into a sustainable community. Action research can help avoid constant “trial and error” in constructing sustainable communities and enhance process efficiency. Meanwhile, an active research approach can help communities better achieve sustainable development. Constructing a sustainable urban community requires energy, effective frameworks, and professional assistance. Achieving these requires a continuous and participatory action research process, and careful exploration of the awareness of community residents, which is the focus of this investigation. 相似文献
83.
针对工件到达时间与加工时间不确定,且存在紧急工件的并行机开放车间调度问题,以TWC(total weighted completion time)与TWT(total weighted tardiness)为优化目标,设计了一种集成FlexSim仿真模型与NSGA-Ⅱ算法的自适应动态调度方法。该方法以FlexSim模型仿真工件的生成和加工为基础,根据车间实时负荷确定动态调度周期,对紧急工件进行右移重调度,利用NSGA-Ⅱ算法生成双目标优化的调度方案。某晶粒拣选车间生产数据的实验结果表明,相较于利用规则的实时动态调度与固定周期重调度,提出的方法能够在最小化调度偏离度的同时获得满意解。 相似文献
84.
Yuk-Man Leung Kar-Lok Wong Chia-Huei Lin Chia-Chia Chao Chun-Hsiao Chou Li-Yun Chang Siao-Wei Chen Tzu-Hurng Cheng Yueh-Hsiung Kuo 《Cellular and molecular life sciences : CMLS》2010,67(1):147-156
Voltage-gated K+ (Kv) channels exhibit slow or C-type inactivation during continuous depolarization. A selective pharmacological agent targeting
C-type inactivation is hitherto lacking. Here, we report that 6β-acetoxy-7α-hydroxyroyleanone (AHR), a diterpenoid compound
isolated from Taiwania cryptomerioides, can selectively modify C-type inactivation of Kv1.2 channels. Extracellular, but not intracellular, AHR (50 μM) dramatically
accelerated the slow decay of Kv currents and left-shifted the steady-state inactivation curve. AHR blocked Kv currents with
an IC50 of 17.7 μM. AHR did not affect the kinetics and voltage-dependence of Kv1.2 channel activation. Channel block by AHR was
independent of intracellular K+ concentration. In addition, effect of AHR was much attenuated in a Kv1.2 V370G mutant defective in C-type inactivation. Therefore,
block of Kv1.2 channels by AHR did not appear to involve direct occlusion of the outer pore but depended on C-type inactivation.
AHR could thus be a probe targeting Kv channel C-type inactivation gate. 相似文献
85.
86.
Zhi-yuan Chen Liu-zhen Bian Li-jun Wang Zi-you Yu Hai-lei Zhao Fu-shen Li Kuo-chih Chou 《矿物冶金与材料学报》2017,24(5)
The carbon deposition behavior on nickel particles was observed within the temperature range from 400 to 800℃ in a pure methane atmosphere.The topography,properties,and molecular structure of the deposited carbon were investigated using field-emission scanning electron microscopy (FESEM),temperature-programmed oxidation (TPO) technology,X-ray diffraction (XRD),and Raman spectroscopy.The deposited carbon is present in the form of a film at 400-450℃,as fibers at 500-600℃,and as particles at 650-800℃.In addition,the structure of the deposited carbon becomes more ordered at higher temperatures because both the TPO peak temperature of deposited carbon and the Raman shift of the G band increase with the increase in experimental temperature,whereas the intensity ratio between the D bands and the G band decreases.An interesting observation is that the carbon deposition rate is suppressed in the medium-temperature range (M-T range) and the corresponding kinetic mechanism changes.Correspondingly,the FWHM of the G and D1 bands in the Raman spectrum reaches a maximum and the intensities of the D2,D3,and D4 bands decrease to low limits in the M-T range.These results indicate that carbon structure parameters exhibit two different tendencies with respect to varying temperature.Both of the two group parameters change dramatically as a peak function with increasing reaction temperature within the M-T range. 相似文献
87.
When a metal makes intimate contact with a semiconductor material, a Schottky barrier may be created. The Schottky contact has many important applications in the integrated circuit (IC) electronics field. The parameters of such contacts can be determined from their current-voltage (I-V) characteristics. The literature contains many proposals for extracting the contact parameters using graphical methods. However, such methods are generally applicable only to contacts with a forward bias, whereas many Schottky contacts actually operate under a reverse bias. Accordingly, the present study proposed a generalized reverse current-voltage (I-V) plot which enables the series resistance, barrier height, and ideality factor of a reverse biased Schottky contact to be extracted from a single set of I-V measurements. A theoretical derivation of the proposed approach was presented and a series of validation tests were then performed. The results show that the proposed method is capable of extracting reliable estimates of the contact parameters even in the presence of experimental noise. 相似文献
88.
基于超声脉冲反射法测量原理,设计了一种多功能超声成像测井仪器,并介绍了该仪器测量的具体实现方
法。该仪器在裸眼井中采用成像测量模式可完成井眼内壁高分辨率成像测量;在套管井采用全波测量模式可同时完
成套损检测及水泥胶结质量评价测量。应用该仪器在实际裸眼井及套管井进行了测试,实测资料表明其在裸眼井中
可对井壁进行裂缝、孔洞、层理等地质构造分析;在套管井中可进行套管厚度成像、套管内外径成像及水泥声阻抗成像
等评价。该仪器可对套管腐蚀及第I 界面水泥胶结质量做定量评价。 相似文献
89.
Lin YY Kiihl S Suhail Y Liu SY Chou YH Kuang Z Lu JY Khor CN Lin CL Bader JS Irizarry R Boeke JD 《Nature》2012,482(7384):251-255
First identified as histone-modifying proteins, lysine acetyltransferases (KATs) and deacetylases (KDACs) antagonize each other through modification of the side chains of lysine residues in histone proteins. Acetylation of many non-histone proteins involved in chromatin, metabolism or cytoskeleton regulation were further identified in eukaryotic organisms, but the corresponding enzymes and substrate-specific functions of the modifications are unclear. Moreover, mechanisms underlying functional specificity of individual KDACs remain enigmatic, and the substrate spectra of each KDAC lack comprehensive definition. Here we dissect the functional specificity of 12 critical human KDACs using a genome-wide synthetic lethality screen in cultured human cells. The genetic interaction profiles revealed enzyme-substrate relationships between individual KDACs and many important substrates governing a wide array of biological processes including metabolism, development and cell cycle progression. We further confirmed that acetylation and deacetylation of the catalytic subunit of the adenosine monophosphate-activated protein kinase (AMPK), a critical cellular energy-sensing protein kinase complex, is controlled by the opposing catalytic activities of HDAC1 and p300. Deacetylation of AMPK enhances physical interaction with the upstream kinase LKB1, leading to AMPK phosphorylation and activation, and resulting in lipid breakdown in human liver cells. These findings provide new insights into previously underappreciated metabolic regulatory roles of HDAC1 in coordinating nutrient availability and cellular responses upstream of AMPK, and demonstrate the importance of high-throughput genetic interaction profiling to elucidate functional specificity and critical substrates of individual human KDACs potentially valuable for therapeutic applications. 相似文献
90.
24阶正交拉丁方的构造方法 总被引:1,自引:0,他引:1
侴万禧 《阜阳师范学院学报(自然科学版)》2002,19(1):8-13,15
提出了一种4t 阶正交拉丁方法的构造方法,阐明了4t 阶正交拉丁方构造的思路,介绍了24阶正交拉丁方构造的基本步骤和构造结果。 相似文献