论会计教师专业发展的外在支持与内在改变

由厦门大学会计发展研究中心提供的第四届会计与财务问题国际研讨会——会计教育改革与发展论文集中的第一部分：会计教育一般11高等教育改革将不断地从注重行政等外在力量向更加注重教师的内在改变过渡，而教师的内在改变依赖于外在支持，即外在支持决定着改变的彻底性。教师专业发展的外在支持为内在改变指明了方向，教师的内在改变是教师质量的提高过程，外在支持与内在改变相互作用，共同促进高等会计教育事业的蓬勃发展

Instability analysis of non-linear unmanned model helicopter control

针对无人机的飞行安全这一典型的系统工程问题,从目前国际惯用的非线性控制和辨识建模的角度出发,通过建立波动信息能量函数模型并结合模糊评价理论,量化分析了dfT变换对无人机系统建模和控制的不稳定性影响;通过对无人机非线性运动模型的分析,说明了该模型中各参数的不稳定关系和不稳定特征,提出了符合SHIlnIkOV定理的三阶非线性模型;通过构造综合影响函数和进行参数配置,确定了无人机非线性运动模型的若干鞍焦点和异宿轨道,从而找到了该系统的若干混沌运动轨道.最后通过仿真证明了直升机非线性运动模型的混沌运动特征和运用dfT辨识模型进行控制的条件下出现无人机不稳定性现象,说明了无人机非线性运动模型混沌运动的存在性及dfT变换中的高阶能量损失和参数配置方式的共同作用模式可构成无人机系统不稳定性的条件.For a typical system engineering problem of unmanned airplane vehicle flight safety,the paper quantitatively analysised the instability effects between the DFT transform and modeling control of the UAV system through the establishment of fluctuation energy function and the combinations of fuzzy evaluation theory from the current international practices perspective of nonlinear controlling and modeling identification,gave out the instability relationship between the parameters and their instability characteristic of the nonlinear motion model of helicopter through the analysis of the modeling process,raised the three-order nonlinear model in line with Shilnikov theorem,showed the possibility of the existence of chaotic orbits.By constructing the comprehensive effect function and parameter configuration,a number of saddle-focus and heteroclinic orbits were discovered.Finally,the chaotic motion characteristics of the non-linear model were proven by stimulation,and the conditions and causes of the existence of the instability were listed by DFT identification model.Additionally,the existence of chaos in a UAV nonlinear motion model was proven.The common mode action of high-level energy loss in DFT transformation and the configuration of parameters constitute the conditions under which a UAV system is not stable.国家985工程二期信息平台建设(0X0007);国家自然科学基金资助项目(61070151);福建省自然科学基金资助项目(2010J01353

Transition from steady to oscillatory convection with chaotic feature in thermocapillary convection

The transition process from steady to turbulent convection via subharmonic bifurcation in thermocapillary convection of half floating zone was studied by numerical simulation and experimental test. Both approaches gave structure of period doubling bifurcations in the present paper, and the Feigenbaum universal law was checked for the system of thermocapillary convection

115例抗-HEV E2-IgM、IgG阳性感染者HEV RNA检测与基因分型研究

目的对戊型肝炎暴发人群中115例抗-HEV E2-IgM、IgG阳性感染者进行病毒RNA检测和基因分型研究,探讨其临床意义。方法对收集的暴发人群中115例抗-HEV E2-IgM、IgG均阳性人员血清和23例戊型肝炎患者粪便标本,采用通用引物进行逆转录-酶链聚合反应(RT-PCR)扩增戊型肝炎病毒Ⅰ、Ⅳ型基因片段,并进行测序和同源进化分析。结果从被检血清中扩增出8例戊型肝炎病毒阳性RNA基因片段,阳性毒株之间核苷酸同源性在97.3%~100%之间,进化树分析提示阳性毒株与戊型肝炎病毒基因Ⅳ型距离最近,与日本株和中国原型株的同源性分别为93.3%~95.3%和86.7%~87.3%;粪便标本中未能检测到戊型肝炎病毒RNA。结论本次急性戊型肝炎暴发流行由戊型肝炎病毒基因型Ⅳ型导致,暴发毒株与日本株有更近的亲缘关系;高灵敏度引物和取样时机是提高戊型肝炎病毒RNA检出率的前提

Experimental Investigation on Thermocapillary Drop Migration at Large Marangoni Number in Reduced Gravity

Results from a space experiment on thermocapillary drop migration conducted on board the Chinese spacecraft ShenZhou-4 are presented in this paper. In the experiment, isolated drops of Fluorinert liquid moved in a matrix liquid of 5cst silicone oil at values of the Marangoni numbers (Ma) ranging up to 5500 and the interferometry images showed the temperature distribution inside the test cell. The drop migration velocity was measured. The experimental results show that the scaled drop migration velocity V/VYGB obviously decreases with Ma increasing the values up to 5500. The space experimental results are also compared with those from our early experiments, other space experiments, and some theoretical predictions

Experimental investigation of thermocapillary migration of isolated drops

Experimental hardware has been developed to perform experiments on the Marangoni migration of drops in the case of intermediate Reynolds numbers in a microgravity environment. The experiments were conducted using the drop shaft free fall facility with a 4.5 second microgravity period in the Microgravity Laboratory of Japan. In this experiment, the thermocapillary velocity of drop migration was measured for drops of different sizes in a series of temperature gradients

Experimental investigation on Marangoni drop rations using drop shaft facility

Experimental hardware has been developed to perform the experiments of drop Marangoni migration in the case of intermediate Reynolds numbers ina microgravity environment. The experiments were completed using the drop shaft free fall facility with a 4.5 s microgravity period in the Microgravity Laboratory of Japan. A special experimental method was designed for experimenting with a short microgravity period. In this experiment, the thermocapillary velocity of drop migration, driven only by the thermocapillary effect, was obtained. Experimental results show that Marangoni migration velocity depends on the temperature gradient and the drop diameter For fixed experimental mediums; the thermocapillary velocity of this present experiment is obviously smaller than the one suggested by YGB linear theory. This conclusion agrees, in general, with that of the ground-based experiment