Erratum to： An advanced segmentation using area and boundary tracing technique in extraction of lungs region

Erratum to：J.Cent.South Univ.（2014）21：3811-3820DOI：10.1007/s11771-014-2366-9The original version of this article unfortunately contained three mistakes.The mistakes are corrected as follows：1）The spelling of third author is incorrect.The correct name is Jae-Young PYUN.2）The information of corresponding author is incorrect.The correct information should be Goo-Rak KWON,Professor,PhD;Tel/Fax：＋98-711-7264102;E-mail：grkwon@chosun.ac.kr     

玻璃制作工具用5%ZrO2纳米铂材的机械合金化制备（英文）

对机械合金化制备的玻璃工业中用作结构零件的Pt-5%ZrO2(体积分数)的进行表征。通过锆丝电爆炸法制备氧化锆(ZrO2)纳米颗粒(粒径<100 nm),并在室温下与铂粉(粒径<44?m)球磨2~72 h。普通球磨至48 h时,铂粒径遵循经典的递减趋势,至72 h时观测到颗粒团聚现象。晶粒尺寸演变规律与颗粒尺寸规律相似,48 h后减至50 nm左右。但是,铂晶粒的均方根应变规律相反,一直在增长,直至48 h时得到最大值,然后出现弛豫。粉末球磨48 h后,采用放电等离子体烧结制成块体。根据测量得到烧结体的质量损失表明:合金虽然相对密度较低,但有较好的热稳定性。     

Surface characteristics of HA coated Ti-Hf binary alloys after nanotube formation

Ti-Hf binary alloys contained 10%, 20%, 30% and 40% (mass fraction)Hf were manufactured in the vacuum furnace system. And then, specimens were homogenized for 24 h at 1 000 °C in argon atmosphere. The formation of oxide nanotubes was conducted by anodic oxidation on the Ti-Hf alloy in 1 mol/L H₃PO₄ electrolytes containing small amounts of NaF at room temperature. The hydroxyapatite (HA) coating made of tooth ash prepared by electron-beam physical vapor deposition (EB-PVD) method. The corrosion behaviors of the specimens were examined through potentiodynamic test in 0.9% NaCl solution by potentiostat. The microstructures of the alloys were examined by field emission scanning electron microscopy (FE-SEM) and x-ray diffractometer (XRD). It was observed that the lamellar structure translated to needle-like structure with Hf contents. Nanotube formed and HA coated Ti-xHf alloys had a good corrosion resistance.     

Cobalt chloride stimulates phosphoinositide 3-kinase/Akt signaling through the epidermal growth factor receptor in oral squamous cell carcinoma

Tumor cells are often found under hypoxic conditions due to the rapid outgrowth of their vascular supply, and, in order to survive hypoxia, these cells induce numerous signaling factors. Akt is an important kinase in cell survival, and its activity is regulated by the upstream phosphoinositide 3-kinase (PI3K) and receptor tyrosine kinases (RTKs). In this study, we examined Akt activation and RTKs/PI3K/Akt signaling using the hypoxia-mimetic cobalt chloride in oral squamous carcinoma cells. Cobalt chloride increases Akt phosphorylation in both a dose- and time-dependent manner. Blocking the activation of the PI3K/Akt pathway using LY294002 abolished Akt activation in response to cobalt chloride, suggesting that Akt phosphorylation by cobalt chloride is dependent on PI3K. In addition, activation of the PI3K/Akt pathway seems to rely on the epidermal growth factor receptor (EGFR), since the inhibition of EGFR attenuated cobalt chloride-induced Akt activation. The results in this study also demonstrate that cobalt chloride increases EGFR protein levels and induces oral squamous cell carcinoma cells to enter S phase.     

An approximation method for performance analysis of assembly/disassembly systems with parallel-machine stations

This note presents an efficient approximation method to evaluate the performance of tree-structured Assembly/Disassembly (AD) systems in which each station consists of multiple identical machines. It is assumed that the times to failure, times to repair, and processing times are exponentially distributed and the capacities of the buffers are finite. The method transforms an AD system with parallel machines in each station to an (approximately) equivalent AD system with a single machine in each station. After the transformation, a decomposition algorithm is used to analyze the performance of the transformed system. The results of computational experiments show that the suggested method gives good estimates in a short time.     

THE UNSTEADY-STATE SOLUTION BY AN OPERATOR THEORY FOR A DISPERSION-TYPE TUBULAR REACTOR WITH AN IMMOBILE ZONE

The analytical solution for an unsteady-state, dispersion-type, tubular reactor model with an immobile zone is obtained by an operator theory in a Hilbert space. The space is defined so as to make the operator positive and self-adjoint with a compact self-adjoint resolvent. A spectral representation is then applied to arrive at the analytical solution.     

PEO/PS/PMMA聚合物电解质膜的制备及性能研究

聚合物电解质是解决锂离子电池安全性问题的有效途径之一。考察了由聚环氧乙烷(PEO)、聚苯乙烯(PS)、聚甲基丙烯酸甲酯(PMMA)、聚乙二醇(PEG)和双三氟甲烷磺酰亚胺锂盐(LiTFSI)组成的固体聚合物电解质膜的性能。采用聚合物共混技术制备了一系列复合聚合物电解质膜,通过扫描电子显微镜(SEM)和X射线衍射(XRD)对膜的形态和晶体结构进行了分析,并详细考察了离子电导率、孔隙率和吸液率等性能。PS和PMMA的加入降低了PEO的结晶度,提高了它的拉伸强度。结果表明,当PEO/PS/PMMA膜中各组成质量比为75:10:15时,聚合物电解质膜具有优良的性能,膜的离子电导率为3.56×10^-4S·cm^-1,拉伸强度为11.56MPa,孔隙率达到57.6%,吸液率高达164.3%。     

PIEZOELECTRIC PROPERTIES OF ((Na0.5K0.5)1−xLix)(Nb0.8Ta0.2)O3 CERAMICS

ABSTRACT

In the ((Na_0.5K_0.5)_1?x)Li_x)(Nb_0.8Ta_0.2)O₃ (NKLNT) system, dense ceramics were developed by conventional sintering process. The electrical properties of NKLNT ceramics were investigated as a function of Li substitution. When the sample sintered at 1100°C for 4 h with the substitution of 2 mol% Li at the morphotropic phase boundary, electro-mechanical coupling factor (k_P) and piezoelectric coefficient (d₃₃) were found to reach the highest values of 0.42 and 210 pC/N, respectively. These excellent piezoelectric and electromechanical properties indicate that this system is potentially good candidate for lead-free material for a wide range of electro-mechanical transducer applications.