Modified super-wide-angle Sagnac imaging interferometer based on LCoS for atmospheric wind measurement

The modified super-wide-angle Sagnac imaging interferometer (MSASII) based on liquid crystals on silicon (LCoS) is proposed as a novel device for the detection of the upper atmospheric wind field. This device employs the phase-only modulation (POM) of LCoS coupled with the MSASII, and can measure phase changes in multi-band emissions without moving mirror. It can be used to replace the conventional Michelson’s interferometer with step-moving mirror device. The optical path difference (OPD) equation of MSASII-LCoS is derived, and the four compensation conditions (field, chromatics, thermal and achromaticity of thermal compensations) are discussed within the scope of wind measurement. The real parameters of LCoS and optical glasses are selected for numerical simulation and analysis. Three aurora lines (732.0, 630.0 and 557.7 nm) are considered, and their phase variations are 3.61, 2.02 and 0.15 fringes at the same incident angle of 3°, respectively. The rate of change of OPD with temperature is the magnitude of 10⁻⁶ cm/K, and the corresponding phase variations are within 0.09 fringes. The accuracy of phase modulation can be 0.614×10⁻² rad when LCoS of 10-bits is used. The novel model MSASII-LCoS shows its advantage for atmospheric wind measurement in the aspects of the overall structure, anti-vibration, operational flexibility and detection accuracy.     

A lower bound for the breakpoint phylogeny problem

Breakpoint phylogenies methods have been shown to be an effective tool for extracting phylogenetic information from gene order data. Currently, the only practical breakpoint phylogeny algorithms for the analysis of large genomes with varied gene content are heuristics with no optimality guarantee. Here we begin to address this lack by deriving lower bounds for the breakpoint median problem and for the more complicated breakpoint phylogeny problem. In both cases we employ Lagrange multipliers and sub-gradient optimization to tighten the bounds. The bounds have been implemented and are available as part of the package (http://www.math.mcgill.ca/bryant/gotree).     

一类高阶微分方程第二特征值的上界

本文考虑形如（－１）ｔＤｔ（ｐ（ｘ）Ｄｔｙ）＝λ（－Ｄ２）ｒｙ，ｘ∈（ａ，ｂ），Ｄｋｙ（ａ）＝Ｄｋｙ（ｂ）＝０，ｋ＝０，１，２，…，ｔ－１｛的第二特征值λ２的上界问题，得到了定理１和定理２，其中定理１的估计系数与［ａ，ｂ］无关，定理２的结果在一定条件下比定理１的好．     

Prolonged Ulcerative Laryngitis

Acute and prolonged laryngitis commonly are diagnosed and treated by primary care physicians. These ailments come to the attention of the otolaryngologist when symptoms are prolonged despite treatment. Since the beginning of 1991, the senior authors (RTS, JRS) have recognized a clinical syndrome defined by prolonged hoarseness, prolonged laryngeal inflammation, and vocal fold ulceration. Patients are frequently young, nonsmokers, and nondrinkers who have had an upper respiratory infection prior to, or associated with, the onset of laryngeal symptomatology. Patients may be affected for up to 1 year despite aggressive medical therapy. This review of 14 patients highlights the features of this previously undescribed entity.     

Reaction diffusion equation with spatio-temporal delay

We investigate reaction–diffusion equation with spatio-temporal delays, the global existence, uniqueness and asymptotic behavior of solutions for which in relation to constant steady-state solution, included in the region of attraction of a stable steady solution. It is shown that if the delay reaction function satisfies some conditions and the system possesses a pair of upper and lower solutions then there exists a unique global solution. In terms of the maximal and minimal constant solutions of the corresponding steady-state problem, we get the asymptotic stability of reaction–diffusion equation with spatio-temporal delay. Applying this theory to Lotka–Volterra model with spatio-temporal delay, we get the global solution asymptotically tend to the steady-state problem’s steady-state solution.     

Action des Enamines Sur Les Allenes Phosphores: Synthese de 1-( N -morpholino ou N -pyrrolidino)-phosphomethylenbicycloalcanes

In this work we studied the reaction of enamines 1 with allenylphosphonates and -phosphine oxides 2 which lead to the 1-( N -morpholino or N -pyrrolidino)-phosphomethylen-bicyclolkanes 3 . The structure of compounds 3 was confirmed by NMR-( 1 H, 13 C, and 31 P) and IR spectroscopy.     

Synthesis of Dibutadienyl Piperazines, 1,1-Dithio and 1,4-Dithio Substituted Dienes from Nitrodienes

Nitrodiene 1a , 1b reacted with 1,4-dithiolbutan and gave the heterocyclic compounds 3a , 3b . 1b gave with 1,3-acetonedithiol the compound 5b . The nitrodiene compound 1b reacted with o-dithiolbenzene ( 6 ) and yielded the ketene dithioacetal ( 7b ). Heterocyclic compounds 11a , 11b , 12a , and 12b were prepared from the reactions of 9a with 2,2'-oxydiethanethiol. The compounds 9a , 9b were prepared from 2-nitropentachloro-1,3-butadiene and alkylthiols ( 8a , 8b ). Mono(thio) substituted diene compound 9b gave dibutadienyl piperazine 14b with piperazine in diethylether.     

Experimental and Theoretical Conformational Analysis of Methylene- and Cyanophosphines and Their Oxides

The structure of a great number of methylenephosphine oxides 1-11 and cyanophosphines and their oxides 12-18 was studied by semiempirical PM3 and ab initio RHF/6-31G** calculations. Obtained results are in good agreement with experimental data (dipole moments, Kerr effect, IR spectroscopy). In 12-18 the contribution of interactions of CN group or Ph ring with lone pair of electrons (LPE) of the P atom, d-orbitals of the P atom, or P=O group is absent.     

Theoretical study of fast repair of DNA damage by cistanoside C and analogs: Mechanism and docking

Experiments show that the natural substances phenylpropanoid glycosides (PPGs) extracted from pelicularis spicata are capable of repairing DNA damaged by oxygen radicals. Based on kinetic measurements and experiments on tumor cells, a theoretical study of the interaction between PPG molecules and isolated DNA bases, as well as a DNA fragment has been performed. An interaction mechanism reported early has been refined. The docking calculations performed using junction minimization of nucleic acids (JUMNA) software showed that the PPG molecules can be docked into the minor groove of DNA and form complexes with the geometry suitable for an electron transfer between guanine radical and the ligand. Such complexes can be formed without major distortions of DNA structure and are further stabilized by the interaction with the rhamnosyl side-groups.