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41.
Summary A set of algorithms designed to enhance the display of protein binding cavities is presented. These algorithms, collectively entitled CAVITY SEARCH, allow the user to isolate and fully define the extent of a particular cavity. Solid modeling techniques are employed to produce a detailed cast of the active site region, which can then be color-coded to show electrostatic and steric interactions between the protein cavity and a bound ligand. 相似文献
42.
Xiaojing Xiang 《Annals of the Institute of Statistical Mathematics》1995,47(1):105-117
A necessary condition for the asymptotic normality of the sample quantile estimator isf(Q(p))=F(Q(p))>0, whereQ(p) is thep-th quantile of the distribution functionF(x). In this paper, we estimate a quantile by a kernel quantile estimator when this condition is violated. We have shown that the kernel quantile estimator is asymptotically normal in some nonstandard cases. The optimal convergence rate of the mean squared error for the kernel estimator is obtained with respect to the asymptotically optimal bandwidth. A law of the iterated logarithm is also established.This research was partially supported by the new faculty award from the University of Oregon. 相似文献
43.
Using the total human/mouse DNA as the probe, screening has been carried out three times with in situ plaque hybridization to obtain the single-copy DNA sequence from the human X chromosome genomic library. The effective rate of screening is 1. 45%. DNAs from clones containing single-copy inserts have been analyzed by a panel of hybrid cells with or without human X chromosome. Three segments, designated by DXFD52,73,75, are mapped to the X chromosome. DXFD52 has been precisely localized on Xq12-q13 with in situ chromosomal hybridization. DXFD52 has been partially sequenced. The results indicate that DXFD52 is a new isolated single-copy segment on the X chromosome. Great progress in the RFLPs study with DXFD52 has been achieved in the population of Chongqing, Sichuan Province. The results show that the DXFD52 can be used to detect the RFLP with Hind Ⅲ, Bgl Ⅱ, and Hinf Ⅰ. DXFD52 will be a potential "landmark" for the construction of the complete linkage map of human genome and the analysis of genomic s 相似文献
44.
We consider the problem of minimum risk point estimation for the parameter =a+b of the exponential distribution with unknown location parameter and scale parameter when the loss function is squared error plus linear cost. In this paper, we propose a sequential estimator of and show that the associated risk is asymptotically one cost less than that given by Ghosh and Mukhopadhyay (1989,South African Statist. J.,23, 251–268). 相似文献
45.
D. Shadman 《Archive of Applied Mechanics (Ingenieur Archiv)》1996,66(7):427-433
Summary A mathematical model for a hydraulic servomechanism is constructed. It is shown that the model, in general, reduces to a nonlinear third-order equation of the formxx+(1+xx+–2
x=p(t). Under certain conditions imposed on the constants involved, it is proved that above equation possesses a periodic solution. 相似文献
46.
Janusz Grabowski 《Annals of Global Analysis and Geometry》1993,11(3):213-220
It is proved that for infinite dimensional Lie groups in the sense of the differential calculus of Frölicher and Kriegl the derivative of the exponential mappings is given by the formula d(exp)(X)Y=dexp(X)(e)
0
1
Adexp(–tX)
Y dt, where stands for the left translation ande is the neutral element.This work was supported by the Alexander von Humboldt-Stiftung. 相似文献
47.
Stephan Weinbruch Michael Wentzel Manfred Kluckner Peter Hoffmann Hugo M. Ortner 《Mikrochimica acta》1997,125(1-4):137-141
In this paper procedures for the characterization of individual aerosol particles by element mapping in the electron microprobe are presented. The number, size and qualitative chemical composition of particles is derived from a combination of secondary or backscattered electron images and element distribution maps. Accuracy of the size distribution and reliability of the qualitative analysis procedure were checked with silicate samples. In order to obtain a semi-quantitative estimate of the chemical composition of individual particles the count rates taken from element distribution maps are corrected for matrix and geometric effects using particle ZAF procedures.Dedicated to Professor Dr. rer. nat. Dr. h.c. Hubertus Nickel on the occasion of his 65th birthday 相似文献
48.
Wolfgang Schattke 《Progress in Surface Science》1997,54(3-4):211-227
Photoemission in the vacuum ultraviolet photon regime has proved to be an effective tool for the investigation of valence band surface electronic structure. The interpretation cannot be exclusively confined to the valence bands but has to consider cross sections with realistic final states consistently designed within the one-step model. Therefore especially in the surface sensitive photoemission, several effects hide the final goal of deducing the energetic and wavefunction structure together with microscopic potential parameters through a convincing agreement of calculated with measured spectra. The final states band structure is much less well understood than the valence band structure under consideration. The optical potential, which controls the surface sensitivity through the underlying damping mechanisms, widely relies on empirical assumptions. Furthermore, the photon field is not only strongly influenced but in the vicinity of the plasma frequency also deteriorated by the electronic response. In view of high resolution spectroscopy the accuracy of the data interpretation is affected, and in fact, band-mapping methods are no longer valid. Examples of recent calculations to account for these effects are reviewed. 相似文献
49.
用计算机多元分析研究冠心病微量元素谱,识别冠心病患者与健康者;非线性映射法判别率男性86.6%,女性96.2%;SIMCA差别法正确回判率男性85.0%,女性88.3%。 相似文献
50.
Summary This paper proposes an optimization model for gas-solid chromatographic separations in a non-linear programming form and an approximate equation of the plate height for the model. A computer-modified mapping procedure is also described for searching the optimum separation conditions. Just five experiments and about 20 minutes of the computer time are needed to establish the optima of column temperature and of the carrier gas linear velocity. The relative deviation between the predicted and the experimental values was found to be within 20% for the plate heights, and within 1.5% for the retention times. 相似文献