非线性Sobolev方程Galerkin解法的后处理与超收敛

研究非线性Sobolev方程Galerkin解法的后处理与超收敛．对半离散及全离散格式,证明了当有限元空间次数,r≥2时,有限元解经过后处理,H1-模和L2-模误差估计可分别提高一阶．     

榨菜中多酚氧化酶特性的研究

为探讨榨菜的保鲜及防褐变技术,对榨菜中多酚氧化酶的研究表明,榨菜中多酚氧化酶以邻苯二酚为底物时,产物最大吸收波长是420 nm,酶的最适pH为7.4,最适反应温度为53℃,Km为0.181 9 mol.L-1.该酶在85℃时仍有较强热稳定性,L-半胱氨酸盐酸盐对该酶活性有很强的抑制作用.     

非矩形区域上非线性抛物型方程组的方向交替GALERKIN方法

利用等参变换、在局部有限单元上近似Ｊａｃｏｂｉ行列式ｐ（ｘ）及系数ｑｉ（ξ，ｕ），１≤ｉ≤ｋ等方法，对非矩形区域上非线性抛物型方程组ｑｉ（ξ，ｕ）ｕｉｔ－∑ｋｊ＝１·（ａ～ｉｊ（ξ，ｕ）ｕｊ）＋∑ｋｊ＝１ｂ～→ｉｊ（ξ，ｕ）·ｕｊ＝ｆｉ（ξ，ｔ，ｕ），１≤ｉ≤ｋ，提出了一类方向交替Ｇａｌｅｒｋｉｎ格式，并得到最优的Ｌ２－和Ｈ１－误差估计．     

An all-optical phase detector by amplitude modulation of the local field in a Rydberg atom-based mixer

Recently, a Rydberg atom-based mixer was developed to measure the phase of a radio frequency (RF) field. The phase of the signal RF (SIG RF) field is down-converted directly to the phase of a beat signal created by the presence of a local RF (LO RF) field. In this study, we propose that the Rydberg atom-based mixer can be converted to an all-optical phase detector by amplitude modulation (AM) of the LO RF field; that is, the phase of the SIG RF field is related to both the amplitude and phase of the beat signal. When the AM frequency of the LO RF field is the same as the frequency of the beat signal, the beat signal will further interfere with the AM of the LO RF field inside the atom, and then the amplitude of the beat signal is related to the phase of the SIG RF field. The amplitude of the beat signal and the phase of the SIG RF field show a linear relationship within the range of 0 to π/2 when the phase of the AM is set with a difference π/4 from the phase of the LO RF field. The minimum phase resolution can be as small as 0.6° by optimizing the experimental conditions according to a simple theoretical model. This study will expand and contribute to the development of RF measurement devices based on Rydberg atoms.     

省域人口抚养比的空间计量实证分析

人口抚养比是衡量人口年龄结构的核心指标之一.文章基于2008年中国省域统计数据,测算Moran'sⅠ空间自相关系数,建立空间计量模型.结果表明,人口抚养比在中国西南、东北地区呈现较强的空间集聚效应;计划生育政策和经济发展的不均衡是造成人口抚养比省际差异的主要原因.     

多孔介质中可压可混溶驱动问题的算子分裂Galerkin方法

且引言本文考虑多孔介质中两相可压可混溶驱动模型．假设区域A为R’中的有界区域．设出表示混合流体第j个分量的浓度,j一1,2．假定密度A一A（户）仅依赖于压力冲。;为对应予第／个分量的压缩系数．足（丢）为岩石的渗透率,P（C）一P（C;,C。）为流体的粘度．吵主）表示岩石的孔限度．设C＝CI。l一CZ则可压可混溶驱动问题的数学模型可描述为“‘：这里我们只考虑分子扩散情形,即D二9（z）dml（d,。为分子扩散常数,I为2X2或3X3单位矩阵）．弥散情形将在文110」中讨论．假定没有流体越过边界：（＊（D＊。c－c…·。二o譬EJ…     

MIXED FINITE ELEMENT METHOD FOR SOBOLEV EQUATIONS AND ITS ALTERNATING-DIRECTION ITERATIVE SCHEME

In this paper, we study the mixed element method for Sobolev equations. A time-discretization procedure is presented and analysed and the optimal order error estimates are derived.For convenience in practical computation, an alternating-direction iterative scheme of the mixed fi-nite element method is formulated and its stability and converbence are proved for the linear prob-lem. A numerical example is provided at the end of this paper.     

流动注射光度法分析地表水中氨氮

采用流动注射光度法分析地表水中氨氮。每小时能测50个样品,氨氮质量浓度在0.010～2.0mg/L与吸光度之间保持良好的线性关系（r=0.9999）,方法的检出限为0.0024mg/L。精密度和准确度较高。对方法的回收率作了试验,所得结果在96.9%～104.7%之间。     

高职“仪表与过程控制”课程教学方法探索与改革

在当前高职院校教育不断改革和发展的形式下,＂仪表与过程控制＂作为电气自动化技术专业的专业核心课,要提高教学质量,教师必须把握课程特点和过程控制发展的趋势,精选教学内容,不断探索教学方法的改进,采用行动导向教学方法,注重理论联系实际,学生通过直观的感性认识逐步上升为理性认识,最后对理论知识进行探究、理解和掌握,进而培养学生对具体问题的分析和解决能力,提高了教学效率和教学效果。     

基于“任务驱动教学法”的高职课堂实践与研究

本文以《仪表与过程控制》的课堂教学实践为例,阐述在高职教学中采用任务驱动教学法的具体实施过程,提出对该课程课堂教学改革的具体思路与实践方法。