Simultaneous representation of interval and interval-containment orders

We characterize the polysemic interval pairs—pairs of posets that admit simultaneous interval and interval-containment representations—and present algorithms to recoginze them and construct polysemic interval representations.This work, supported in part by NSF grant CCR-9300079, also appears in the author's doctoral thesis [9], written at the Johns Hopkins University under the supervision of Professors Edward R. Scheinerman and Michael T. Goodrich.     

Microwave spectrum and substitutional structure of CH2DF

Forty-two transitions of the microwave spectrum of CH₂DF have been observed in the region between 75 and 450 GHz. The measurement of both a-type and b-type transitions makes possible the analysis of the spectrum and the accurate calculation of the rotational constants (in MHz): = 119 675.0535 ± 0.074, = 24 043.4415 ± 0.072, ? = 22959.3732 °0.072, °j = 0.049371 ±0.00011, °_jk = 0.34268 ±0.0006, 2_k = 3,3774 ± 0.0035, δ _j = 0.002329 ± 0.000045, δ_k = 0.0687 ± 0.036. These constants, in combination with the results of earlier work on the symmetric speci r_s structure calculation based entirely on high-accuracy microwave data. The structural parameters are r_CH = 1.100 Å, r_CF = 1.383 Å, and ∠HCH = 110° 37'.     

Some observations on the interdependence of cyanide concentration and atomization efficiency in the nitrous oxide-acetylene flame

A relationship is derived between CN concentration and atomization efficiency in the C₂H₂-N₂O flame. The relationship is examined under various experimental conditions and β values are estimated for a number of elements. The possibility of complex vapour phase oxide formation by U is considered.     

一种统一纠错编码的新方法

本文给出了一种建立在组合理论基础上的新编码方法．它以S（U，V）阵列为特征，不但可以在人们熟知的一些最佳码间建立起普遍的关系，而且在给定的编码约束条件下，还能发现和构造一些有实用价值的新码．     

A New Look at Mourre’s Commutator Theory

Mourre’s commutator theory is a powerful tool to study the continuous spectrum of self-adjoint operators and to develop scattering theory. We propose a new approach of its main result, namely the derivation of the limiting absorption principle (LAP) from a so called Mourre estimate. We provide a new interpretation of this result. Received: September 20, 2006. Revised: February 1, 2007.     

美国──加拿大尼亚加拉大瀑布的发育演化

本文在分析尼亚加拉地区第四纪冰川与河谷成因联系的基础上，论述了现代大瀑布的发育、演化及年代学问题；详细探讨了瀑布区的地质特征、控制瀑布及峡谷后退稳定性的地貌过程；最后讨论了瀑布将来的发展趋势。     

Intrinsic surface binding energy shifts in Yb metal

We report on the four-peak structure observed in the region of 4f photoemission in Yb metal, using synchrotron radiation in the energy range 70–200 eV. We conclude, contrary to previous reports, that the doublet associated with surface emissions results from an intrinsic surface shift on clean regions of the surface. We also demonstrate that the observed structure is consistent with earlier XPS measurements, and we set an upper limit on the width of the bulk peaks.