Electron-pair radial density functions

We introduce and discuss a generalized electron-pair radial density function G(q; a) that represents the probability density for the electron-pair radius |r ₁+ar ₂| to be q, where a is a real-valued parameter. The density function G(q; a) is a projection of the two-electron radial density D ₂(r ₁, r ₂) along lines r ₁ + ar ₂ ± q = 0 in the r ₁ r ₂ plane onto a point in the qa plane, and connects three densities S(s), D(r), and T(t), defined independently in the literature, as a smooth function of a: For an N-electron (N ≥ 2) system, S(s) = G(s; + 1), D(r) = 2G(r; 0)/(N − 1), and T(t) = G(|t|;−1)/2, where S(s) and T(t) are the electron-pair radial sum and difference densities, respectively, and D(r) is the single-electron radial density. Simple illustrations are given for the helium atom in the ground 1s² and the first excited 1s2s ³S states.     

State-space modeling for seismic signal analysis

The time series utilized for geodetic signal analysis, such as strain and groundwater level data, usually is largely affected by barometric pressure, earth tide and precipitation, and also suffer from missing observations due to instrument maintenance or breakdown. To detect informative geodetic signal from heavily noise-affected data, one must build a time series model for decomposition of the data taking into account the characteristics of effects from these covariates. This paper proposes a new modeling method for detecting geodetic signal from earthquake-related time series data by introducing pole-restricted precipitation model, jump component and pre-processing with AR model for interpolating missing observations. Using the proposed method, a geodetic sample data can be decomposed stably into several components including geodetic trend signal, barometric pressure response, earth tidal response, precipitation response and data level shift due to mechanical maintenance or breakdown. The decomposition of the time series and the interpolation of the missing observations are performed very efficiently by using the state-space representation and the Kalman filter/smoother. Finally, case studies of real geodetic sample data demonstrate the effectiveness of the proposed modeling method that lead to some important findings in seismology.     

Pummerer rearrangement of 1-deoxy-5-thioglucopyranose oxides; novel synthesis of 5-thioglucopyranose derivatives

The Pummerer rearrangement of 3,4-O-isopropylidene-1-deoxy-5-thiopyranose oxide derivatives took place at the C1 position regioselectively to give the corresponding 5-thiopyranoses. The reaction mechanism of this reaction is also discussed.     

Synthesis and evaluation of a new water-soluble fluorescent red dye,xanthene bis-C-glycoside

Condensation of 2 eq. of C-β-D-glucosylphloroacetophenone with glyoxylic acid in an aqueous solution of Na₂CO₃, followed by air oxidation in MeOH in the presence of 11 eq. of pyridine to afford a 36% yield of a bright red dye, xanthene bis-C-glycoside. This dye is 10 times more fluorescent (Φ_{f [EtOH]}^{581 nm} = 3.9 × 10⁻²) and 7.5 times more water-soluble (57 mg/mL H₂O) than the natural red pigment, carthamin. Detailed NMR analysis of its methyl analogs was used to confirm the structure of the dye as methyl 4,5-diacetyl-1,3,8-trihydroxy-3-oxo-3H-2,7-di-C-β-D-glucopyranosylxanthene-9-carboxylate from among three possible ring-closure isomers. Xanthene is safe and shows high light-resistance; therefore, xanthene bis-C-glycoside could be used as a food colorant or an in vivo probe.     

Significance of water quality and radiation wavelength for UV photolysis of PhCs in simulated mixed solutions

Ultraviolet (UV) photolysis of sixteen pharmaceutical compounds (PhCs) in mixed solutions with four types of water and two sets of UV radiation was investigated. UVC (254 nm) photolysis was ineffective at eliminating a large number of PhCs while a big number of them were refractory. However, vacuum UV (VUV: 185 nm + 254 nm) photolysis in the same experimental conditions eliminated the PhCs almost completely. The eliminations in ultrapure water (UPW), tap water (TW) and Neya River water (NRW) and their organic/inorganic contents were inversely correlated, which was more evident in VUV photolysis. Natural organic matter (NOM) in NRW did not have an impact in indirect photolysis, but effluent organic matter (EfOM) in secondary-treated effluent (NWTPE) enhanced indirect photolysis, which was more evident in VUV photolysis underlining the point that radiation wavelength/intensity can be a limiting factor in organic-rich waters. Moreover, VUV photolysis was far superior (90% mineralization) to UVC photolysis (10% mineralization) for PhCs mineralization. The greatly enhanced elimination and mineralization efficiencies observed for VUV photolysis were attributed to accelerated direct photolysis with 185 nm wavelength and indirect photolysis involving ^·OH. The results demonstrated efficacy of VUV photolysis in wastewater treatment and its potential use as a tertiary treatment.      

An Efficient Branch-and-bound Algorithm for Finding a Maximum Clique with Computational Experiments

We present an exact and efficient branch-and-bound algorithm MCR for finding a maximum clique in an arbitrary graph. The algorithm is not specialized for any particular type of graph. It employs approximate coloring to obtain an upper bound on the size of a maximum clique along with an improved appropriate sorting of vertices. We demonstrate by computational experiments on random graphs with up to 15,000 vertices and on DIMACS benchmark graphs that in general, our algorithm decidedly outperforms other existing algorithms. The algorithm has been successfully applied to interesting problems in bioinformatics, image processing, design of quantum circuits, and design of DNA and RNA sequences for biomolecular computation.     

Range of separation of potential tool for bioseparation, microchip electrophoresis system, for DNA polymorphisms on the human Y-chromosome.

For the requirement of a high, fast and sufficient technology to suit the needs of 21st century biotechnology, the separation range of a microchip electrophoresis system was studied. Two DNA fragments on the human Y-chromosome, SY594 (82 bp) and 12f2 (88 bp), were successfully separated with a reproducibility of 1.9% and an accuracy of 2.8%. Then, a mixture of 10 DNA markers ranging from 61 bp to 189 bp was successfully separated with high resolution. All of these results demonstrate the superiority of microchip electrophoresis as a tool for 21st century bioseparation.     

Energy functional of the axial marginal densit in linear molecules

The axial marginal density is defined as a projection of the three-dimensional electron density onto the symmetry axis in a linear molecule, and represents essential features of the bonding characteristics of that system. Based on the local scaling method, a theory is presented for the direct and variational determination of the axial marginal density. Illustrative applications are presented for the ground 1so_g state of the H ₂ ⁺ molecule, and simple yet sufficiently accurate marginal densities are reported.     

Numerical Hartree–Fock results for atoms Cs through Lr

Accurate nonrelativistic numerical Hartree–Fock results are reported for the heavy atoms Cs (Z = 55) through Lr (Z = 103) in their ground states. © 1995 John Wiley & Sons, Inc.