An Extremal Limit Theorem for the Argmax Process of Brownian Motion Minus a Parabolic Drift

We study the extremal behavior of the stationary processes and , on increasing intervals [0,T], as , where V(t) is the location of the maximum of standard two-sided Brownian motion minus a parabolic drift. The result can be applied to the asymptotic behavior of the -risk of several nonparametric maximum likelihood estimators.     

The molecular anvil model of an enzyme taking into consideration the flexibility of enzyme molecules

The concept of a molecular anvil model of an enzyme, assuming a rigid enzyme molecule, is introduced. Two distinct features of enzymes, high catalytic power and high specificity, are reasonably and consistently explained. The dynamic nature of molecular anvil action is stressed. The origin of the high catalytic power is the spontaneous creation of a high energy state at the anvil site. The origin of the high specificity is a high sensitivity of the maximum accessible potential energy to the relatively extruded distance of the molecular anvil. The flexible model is developed by assuming a flexible enzyme molecule. It is deduced from this flexible model that enzyme activity shows a maximum with a wide range of monotonous change of the configuration of the enzyme molecule. This is the origin of the general property of enzymes that enzyme activity shows a maximum with monotonous variation of environmental parameters such as pH, temperature, pressure or some times concentration of chemical substances. The induced fit theory of Koshland is reasonably explained. The relation and differences between individual theories of enzymes are discussed. The enzymological basis of the complex regulation of biological organisms is discussed. The inversion of the sign of control of effectors is predicted when environmental parameters are varied. This concept may be useful in designing artificial enzymes or high specificity catalysts.Presented at the Fourth International Symposium on Inclusion Phenomena and the Third International Symposium on Cyclodextrins, Lancaster, U.K., 20–25 July 1986.     

三组分共聚酯数均聚合度和数均分子量的计算方程

为便于生产控制以制得预定分子量的产物，根据直接酯化法合成聚对苯二甲酯乙二酯（ＰＥＴ）共聚酯的特点，综合考虑各种主、副反应，从统计观点出发，对三组分ＰＥＴ共聚酯体系的齐聚物和缩聚物，分别建立了其数均聚合度Ｘｎ和数均分子量Ｍｎ的简化和非简化计算方程．将简化Ｘｎ方程与Ｃａｒｏｔｈｅｒｓ方程进行计算比较，其结果完全相同；将简化Ｘｎ方程应用于二组分聚酯体系，其形式与传统的二组分线型缩聚物Ｘｎ方程形式相同，各Ｘｎ和Ｍｎ方程可推广应用于二组分聚酯体系和三组分以上的多组分共聚酯体系．     

聚合物异核交叉弛豫及二维NOE谱

Kover和Batta首次采用选择性质子π脉冲来测定~(13)C自旋-晶格弛豫速率并与常规反转回复法测定的自旋-晶格弛豫速率相比较求出了交叉弛豫速率,并以此来计算异核间的距离,但他们的计算方法仅适用于满足极端窄化条件的刚性球状分子。二维异核NOE谱(HOESY)是1983年才发展起来的二维NMR技术,它可用来研究异核间的交叉弛豫作用及研究分子间相互作用。Kover和Batta在此方面作了许多     

Time-integrated monitoring of polycyclic aromatic hydrocarbons (Pahs) in groundwater using the ceramic dosimeter passive sampling device

Passive sampling relies on the uptake of contaminants into appropriate sampling devices along a diffusion gradient without using pumps or bailers. Thus, for example, in groundwater sampling, changes to flow due to pumping can be avoided. If the diffusion gradient can be maintained for extended periods, contaminants can be sampled continuously over time without any action, allowing to determine time-weighted average contaminant concentrations. We here show that the Ceramic Dosimeter, a solid receiving phase passive sampler using a ceramic membrane as sorbent container and diffusion barrier, can be used without calibration for the long-term monitoring of polycyclic aromatic hydrocarbons (PAHs) in groundwater.     

Comparison of Hydrogen Bonds in FH—CO and FH—OC Weakly Bound Dimer Complexes

Weakly bound dimer complexes FH—CO and FH—OC were investigated using various ab initio and density function theory (DFT) methods. This study compares the strengths of the H—C H‐bond in FH—CO and the H—O H‐bond in FH—OC. The energy difference between dimers, the H‐bond energy, the inter‐monomer distance, the inter‐monomer vibration frequencies, the red shift of the HF stretching frequency, and the elongation of HF bond, all demonstrate that the H—C H‐bond is stronger than the related H—O H‐bond, according to all methods. The calculated Gibbs energies of the formation of the two dimers show that the weakly bound complexes are unstable at room temperature (T = 298 K) and ordinary pressure (P = 1 atm). However, decreasing T or increasing P monotonically decreases ΔG and increases the related equilibrium constant, K, of their dimer formation.     

3D卷积自动编码网络的高光谱异常检测

高光谱图像包含丰富的地物光谱信息,在遥感图像领域有着巨大的发展前景.高光谱图像异常检测无需任何先验光谱信息,便可检测出图像中的异常目标.因此,在国防军事和民用领域都有广泛的应用,是现阶段高光谱图像处理领域的研究热点.然而,高光谱图像存在数据复杂、冗余性强、未标记以及样本数量少等特点,这给高光谱图像异常检测带来了很大的挑...     

An Improved K-Means Algorithm Based on Evidence Distance

The main influencing factors of the clustering effect of the k-means algorithm are the selection of the initial clustering center and the distance measurement between the sample points. The traditional k-mean algorithm uses Euclidean distance to measure the distance between sample points, thus it suffers from low differentiation of attributes between sample points and is prone to local optimal solutions. For this feature, this paper proposes an improved k-means algorithm based on evidence distance. Firstly, the attribute values of sample points are modelled as the basic probability assignment (BPA) of sample points. Then, the traditional Euclidean distance is replaced by the evidence distance for measuring the distance between sample points, and finally k-means clustering is carried out using UCI data. Experimental comparisons are made with the traditional k-means algorithm, the k-means algorithm based on the aggregation distance parameter, and the Gaussian mixture model. The experimental results show that the improved k-means algorithm based on evidence distance proposed in this paper has a better clustering effect and the convergence of the algorithm is also better.     

含有Berkson与经典测量误差的非线性模型估计

摘要：使用一个两阶段最小距离矩估计方法,给出了含有Berkson测量误差和经典线性测量误差的非线性模型估计.得到了参数的一致估计及其渐近正态性.此外,基于傅里叶分析方法推导出了非线性函数的一个识别方程.