响应面法优化固定化荧光假单胞菌磷脂酶B的研究

以脱胶油磷含量为响应值,采用响应面法和Central-Composite设计对制备固定化荧光假单胞菌磷脂酶B(PfPLB)主要工艺参数(海藻酸钠浓度、壳聚糖浓度和加酶量)进行了优化,并且采用回归分析拟合了三个固定化因子与响应值(磷含量)的回归模型.该模型预测最佳的固定化Pf-PLB条件为:海藻酸钠3%,壳聚糖1.14%,加酶量1000 U/kg.研究固定化Pf-PLB的酶学性质,结果表明其最适反应温度为40℃,比游离酶提高15℃;最适反应pH为5.5,比游离酶降低1个pH单位.固定化Pf-PLB具有较好的酶活稳定性,连续反应6次,其相对活性为初始值的51.6%,显示出良好的应用前景.     

Designing for a Response Transformation Parameter

We investigate D -optimum designs for experiments in which a linear model holds after an unknown power transformation of the univariate response variable. This is a departure from standard D -optimal design in which an appropriate scale for the response is assumed known before data collection. The design problem that we formulate is intrinsically non-linear, requiring characterization of likely parameter values. Several applications are presented to illustrate the importance of recognizing the role of response transformations at the design stage.     

Finite sample properties of maximum likelihood and quasi-maximum likelihood estimators of egarch models

In this paper I examine finite sample properties of the maximum likelihood and quasi-maximum likelihood estimators of EGARCH(1,1) processes using Monte Carlo methods. I use response surface methodology to summarize the results of a wide array of experiments which suggest that the maximum likelihood estimator has reasonable finite sample properties. The Gaussian quasi-maximum likelihood estimator has poor finite sample properties when the data generating process has conditional excess kurtosis. Some of these poor properties appear to be asymptotic in nature.     

Vec and vech operators for matrices,with some uses in jacobians and multivariate statistics

The vec of a matrix X stacks columns of X one under another in a single column; the vech of a square matrix X does the same thing but starting each column at its diagonal element. The Jacobian of a one-to-one transformation X → Y is then ∣∣?(vecX)/?(vecY) ∣∣ when X and Y each have functionally independent elements; it is ∣∣ ?(vechX)/?(vechY) ∣∣ when X and Y are symmetric; and there is a general form for when X and Y are other patterned matrices. Kronecker product properties of vec(ABC) permit easy evaluation of this determinant in many cases. The vec and vech operators are also very convenient in developing results in multivariate statistics.     

舆情表达与回应机制视阈下的协商民主建设

推进协商民主制度化发展,需要建立健全能够推动协商民主有效嵌入各个决策制定和实施过程的实现机制和保障机制。加强舆情表达与回应机制建设,体现了协商民主的内在要求,有助于完善社情民意反映制度,构建官民良性沟通互动机制,推动公民有序政治参与,是协商民主制度化发展的重要环节和有效保障,也是推进协商民主制度化的一条重要实现路径。     

论公民网络政治参与与维持稳定——基于政治系统论的视角

公民网络政治参与作为一种新型政治参与方式在我国的兴起,主要是由于目前政治生态条件下公民自发表达的无效,以及渊源于匿名性和平等性的网络参与在规避可能遭遇的实然表达所带来的政治风险方面的优势。但是网络政治参与在推动新型政治输入的情况下,也带来了一些诸如极端自由、网络话语强权等可能冲击社会稳定的新问题。目前,网络方面的技术困境和网民分散化,以及政府自身的网络规范缺失、决策封闭性等,都成为政府应对这些新问题的障碍。所以,政府维稳应着重于完善网络参与规范、推动网民理性化和实现政务公开。     

边疆民族地区突发事件应对中的地方立法研究

边疆地区突发事件表现形态复杂、孕育爆发隐蔽、单一突发事件容易衍生为社会安全事件或政治事件、具有国际性和跨境性.《突发事件应对法》的不足主要在于应对组织体系不健全,应急预案与《突发事件应对法》等法律、法规不协调,缺乏单行法和上位法的衔接,应急预案要求不明确而事前准备工作缺乏保障性措施.边疆民族自治地方应发挥地方立法的主动性、积极性,协调与《突发事件应对法》等相关法律、法规的关系,依法处置突发事件.