A two-tier location management mechanism for IMS

This paper proposed a two-tier location management mechanism(TTLM)by improving the currentregistration mechanism(CR)in IP Multimedia Subsystem(IMS).The TTLM includes the visited networkregistration and the home network registration,in which the visited network registration is responsible forre-registration in IMS.When subscriber roams,the location information of home network will be updatedby the visited network based on the change of user equipment(UE)' s IP address.Therefore the TTLMcan reduce the tim...     

Beta-catenin/TCF4 transactivates miR-30e during intestinal cell differentiation

The Wnt/beta-catenin/TCF4 pathway plays critical roles in the maintenance of small intestinal epithelium; however, downstream targets of the beta-catenin/TCF4 complex are not extensively characterized. We identified miR-30e as an immediate target activated by the beta-catenin/TCF4 complex. miR-30e was detected in the peri-nuclear region of the intestinal crypt IEC-6 cells. Bioinformatics analysis revealed clustered beta-catenin/TCF4 binding sites within the miR-30e promoter region. This promoter region was cloned into pGL3-control luciferase reporter vector, with the enhancer region removed. Transfection of pCMV-SPORT6-beta-catenin expression vector dose-dependently increased luciferase activity, and co-transfection of pCMV-SPORT6-TCF4 expression vector further enhanced the promoter activity. Dexamethasone-induced IEC-6 cells differentiation caused a 2.5-fold increase in miR-30e expression, and upon beta-catenin siRNA transfection, miR-30e increased 1.3-fold. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay confirmed the binding between beta-catenin/TCF4 complexes from IEC-6 nuclear extracts and the putative sequences in the miR-30e promoter. These results demonstrate that beta-catenin/TCF4 transactivates miR-30e during intestinal cell differentiation.     

Synthesis and photo-responsive behaviors of hollow polyazobenzene micro-spheres

By means of distillation precipitation polymerization, the silica-hybrid particles with polyazobenzene shell (PAzo@SiO₂) micro-spheres were prepared with 6-(4-methoxy-4′-oxy-azobenzene) hexyl methacrylate (Azo-M) as monomer, divinylbenzene (DVB) as cross-linker, and ~250 nm vinylated sol-gel silica particles as template. Hollow polyazobenzene microspheres were further developed after selective removal of the silica cores with HF solution. When the content of DVB related to Azo-M is 20 wt%, the acetonitrile is 200 mL, and the polymerization time is 4.5 h, the hollow PAzo microspheres with about 20 nm shell are successfully fabricated. These hollow PAzo microspheres have excellent reversible photoisomerization, and their first-order rate constant of trans-cis isomerization only decreases 11.8% compared with homopolymer of azobenzene (Homo-PAzo).     

Optimal dividend strategies in a double compound poisson risk process

In this paper, we consider a double compound Poisson risk model involving two independent classes ofinsurance risks with a threshold dividend strategy. We derived the integro-differential equations (IDE) with certain boundary conditions for the present value of dividends until ruin. When the claims from both classes are exponentially distributed, we show that the threshold dividend strategy is an optimal dividend strategy.     

浅谈声乐教育中的心理因素

本文认为,心理在声乐教学中的地位非常重要,在声乐教育中应该注意对学生心理情感的培养.     

独立学院电气工程及其自动化实践教学探索

实践教学是培养学生实践能力、创新能力和综合能力的关键环节,对于增强学生的综合能力以及社会适应力都有重要作用。独立学院作为应用型人才的培养基地,发挥实践教学的作用显得尤为重要。该文总结广州大学松田学院现行实践教学中存在的主要问题,逐步分析问题形成的原因,在此基础上结合电气工程及其自动化专业本身特点,在实验教学、毕业论文等多个方面提出新的改革方式,进而开展多层次、多渠道的实践教学改革,对促进独立学院教学工作具有重要意义。     

广西风电场选址重点区域分析

广西北部处于云贵高原东南边缘,南部濒临北部湾,因而形成了广西的特色气候.文章通过分析风速的影响因素,结合广西气候特征,提出在广西能够形成较好风能资源的地形特征,并提出广西风电场选址的三类重点区域,为风电场选址提供依据.     

基于C~#+SQL SERVER的网站通用注册模块的实现方法

登录注册页几乎是各个正规网站的访问起始页,这是出于网站安全考虑,也是各公司企业为方便管理众多客户所必需。本文以C#+SQL Server为基础设计了一个通用的注册模块,此模块可方便实现在页间传递参数或数据,具有较高实用性。     

Theoretical analysis of reactive solid-liquid interfacial energies

The characterization of reactive solid-liquid interfacial energies and solid surface energies is a pressing problem in materials science and surface science. Based on the concept that unbalanced forces doing work, a mathematical formulation between surface energies and interfacial energies for reactive wetting is presented. The resulting formalism has significant generality in which the equilibrium Young’s equation for solid-liquid interfacial energies is just a special case. It is shown that a solid-liquid interfacial energy at non-equilibrium is always higher than that at equilibrium, and that the transformation of reactive interfaces to equilib-rium interfaces is an inevitable, spontaneous process. The numerical range of solid-liquid interfacial energies γsl for a limited, solid-liquid interfacial wetting system was calculated to be 0 ≤γsl ≤γsg. The calculation methods for reactive solid-liquid interfacial energies and solid surface energies are presented. They are significant for composite materials and weld, powder sinter, package of electronic devices, and other surface and interfacial issues in metallurgy.     

钠桥联的一维链状钴(Ⅱ)配合物的合成、结构与光谱性质

以水杨醛肟为原料,经钠汞齐还原得到2-氨甲基-苯酚,再与水杨醛反应合成了配体L(L=bis(2-hydroxybenzyl)-amine).使用L配体和Co(NO3)·6H2O在水-甲醇溶液中制备了钠桥联的1维链状Co(Ⅱ)配合物[Na(methoxide)CoL2]n,解析了其晶体结构,应用元素分析、红外光谱等技术对配合物进行了表征.