bluuebunny/crossref_metadata_2025 huggingface dataset:
Syntheses of [60]Fullerene and N,N-Bis(4-biphenyl)aniline-Tethered Rotaxane: Photoinduced Electron-Transfer Processes via Singlet and Triplet States of [60]Fullerene
Authors: Sandanayaka Atula S D , Ikeshita Kei-ichiro , Watanabe Nobuhiro , Araki Yasuyuki , Furusho Yoshio , Kihara Nobuhiro , Takata Toshikazu , Ito Osamu
Published: June 2005

A rotaxane containing [60]fullerene (C60) and N,N-bis(4-biphenyl)aniline (BBA) moieties was synthesized. In this structure, C60 acting as an electron acceptor, is attached to the crown-ether ring through which the axle with terminal BBA moieties acting as electron donors on both ends is penetrating. This rotaxane had a neutral amide moiety in the center of the axle in which two BBA moieties act as stoppers. The intra-rotaxane photoinduced electron-transfer processes of the C60 and BBA moieties were investigated by time-resolved transient absorption and fluorescence measurements while changing solvent polarity and temperature. Time-resolved transient absorption measurements of the rotaxanes confirmed that the long-lived charge-separated state (C60•−; BBA•+)rotaxane was formed via both the excited singlet and triplet states of C60 (1C60* and 3C60*, respectively) in polar solvents. The rate constants for charge-separation process were evaluated to be in the range of (3.6–3.7) × 108 s−1 via 1C60* and (5.1–5.6) × 107 s−1 via 3C60* in the ratio of (0.36–0.38):(0.43–0.51). The rate constants of charge recombination were 2.5 × 106 s−1 and 4.4 × 106 s−1, corresponding to the lifetimes of the charge-separated states of 400 ns and 230 ns in THF and benzonitrile, respectively. By the temperature dependences, the activation free-energy changes of charge-separation process via 3C60* were evaluated to be 0.10 eV, while those of the charge-recombination process were estimated to be 0.03 eV in THF and benzonitrile. These low activation energies are one of the characteristics of through-space electron transfer in the rotaxanes.
Characteristics of a Hydrogen Concentration Cell Constituted with a Redox Pair of 2-Propanol Dehydrogenation and Acetone Hydrogenation
Authors: Ando Yuji , Sasaki Tomokazu , Yatabe Yuka , Saito Yasukazu , Tanaka Tadayoshi
Published: June 2005

A hydrogen concentration cell, constituted with a redox pair of 2-propanol dehydrogenation and acetone hydrogenation on electrode catalysts, has been studied, with which low-quality waste heat below 100 °C can be converted into electric power. The magnitudes of the open-circuit voltage (VOC) of this cell were found to be dependent on the anode abilities concerned with C–H bond splitting and hydrogen spillover. The kinetical spillover capabilities of carbon-supported Pd-based composite metal catalysts were obtained separately and compared with the magnitudes of VOC, whereas the catalytic dehydrogenation activities for 2-propanol were more closely related with the magnitudes of a short-circuit current (ISC).
Syntheses, Crystal Structure, and Magnetic Properties of Mn12 Single-Molecule Magnets with Naphthalenecarboxylate Bridges, [Mn12O12(O2CC10H7)16(H2O)4] and Their Tetraphenylphosphonium Salts
Authors: Bian Guo-Qing , Kuroda-Sowa Takayoshi , Nogami Tadahiro , Sugimoto Kunihisa , Maekawa Masahiko , Munakata Megumu , Miyasaka Hitoshi , Yamashita Masahiro
Published: June 2005

The preparation and physical characterization are reported for three Mn12 single-molecule magnets (SMMs) having naphthalenecarboxylate bridges, [Mn12O12(2-nc)16(H2O)4] (1, 2-ncH = 2-naphthalenecarboxylic acid), its Ph4P+ salt (2) and [Mn12O12(1-nc)16(H2O)4] (3, 1-ncH = 1-naphthalenecarboxylic acid). Complex 1·2CH2Cl2·4.5H2O crystallizes in the monoclinic space group C2/c, with cell dimensions at −160 °C of a = 28.524 Å, b = 17.819 Å, c = 36.058 Å, β = 92.399°, and Z = 4. The X-ray structure analysis of 1·2CH2Cl2·4.5H2O reveals that each [Mn12] molecule is connected to the neighboring molecules through eight π···π interactions to form a two-dimensional structure within the bc-plane. This is the first SMM that self-assembles two-dimensionally via π···π interaction. From Arrhenius plots of the frequency dependence of the temperatures of the χ″M peaks, the effective energy barriers Ueff for the reversal of the magnetization spin were estimated to be 61 K, 53 K, and 61 K for high-temperature phases of 1–3, respectively, and 31 K and 33 K for the low-temperature (LT) phases of 1 and 3, respectively. The analysis of the reduced magnetization data suggests that the LT phase of 1 has an S = 9 ground state with g = 1.998 and D = −0.61 K.
Syntheses, Structures, Spectroscopic Properties, and Thermal Behavior of Nickel(II) Mixed-Ligand Complexes with N,N,N′,N′-Tetramethylethylenediamine, Benzoylacetonate, and a Halide Anion
Authors: Miyamoto Keiko , Sakamoto Mariko , Tanaka Chikashi , Horn Ernst , Fukuda Yutaka
Published: June 2005

A series of nickel(II) complexes comprising N,N,N′,N′-tetramethylethylenediamine (tmen), benzoylacetonate (bzac), and a halide anion (X), Ni(tmen)(bzac)X·n(H2O)(n = 1–4, X = Cl, Br, I), have been synthesized. A crystallographic study revealed that the chloride anion coordinates to the central metal, while bromide and iodide anions are located in the outer coordination sphere as the counter anion; the metal has a slightly distorted octahedral geometry, and the two monodentate ligands (aqua and chloro) are in the cis-position. In bromide and iodide complexes, having two water molecules of crystallization, a ladder-like hydrogen bond network is formed among halide anions, aqua ligands, and water of crystallization. In a chloride complex having no water of crystallization, a dimer is formed by strong intermolecular hydrogen bonding between the aqua ligand and the chloro and the benzoylacetonate ligands of the neighboring molecule. The behaviors of the complexes in solution vary, depending on the nature of the solvents, including deaquation and disproportionation, causing contrasting color changes of the solutions. The presence of a proposed intermediate in the disproportionation reaction, namely a 5-coordinated complex, was confirmed. Thermal gravimetric analysis suggests that these complexes lose water of crystallization, undergo deaquation–anation, and then lose the coordinated water before disproportionation into two ternary complexes.
Antidiabetic Activity of Zn(II) Complexes with a Derivative of l-Glutamine
Authors: Matsumoto Kinuyo , Yamamoto Shuhei , Yoshikawa Yutaka , Doe Matsumi , Kojima Yoshitane , Sakurai Hiromu , Hashimoto Hiroko , Kajiwara Naemi M
Published: June 2005

The insulinomimetic activity of zinc(II) complexes Zn(gln-m)2 and Zn(gln-e)2, respectively, with l-γ-glutamyl-methylamide (gln-m) and -ethylamide (theanine: gln-e), components of green tea, were compared to that of Zn(gln)2 with l-glutamine (gln) in an in vitro study using isolated rodent adipocytes treated with epinephrine in the presence of glucose, expressed as the IC50 value (50% inhibition concentration) of free fatty acids (FFA) released from fat cells. The former were found to have higher inslinomimetic activity than that of the latter. The IC50 values of the former were 0.61 and 0.56, respectively. Then, the anti-diabetic activity of a zinc(II) complex, Zn(gln-e)2, was examined in an in vivo experiment on KK-Ay mice, model animals of type-2 DM, by the intraperitoneal (ip) injection of 3–4 mg Zn/kg b.w./day for 13 days. The blood-glucose level of a group treated with a Zn complex, Zn(gln-e)2, decreased significantly after 13 days compared to those of non-treated and gln-e treated groups. The serum concentrations of triglyceride (TG) and HbA1c decreased significantly in Zn(gln-e)2 treated KK-Ay mice compared to those of the gln-e treated group, respectively. Furthermore, the improvement in glucose tolerance was confirmed by an oral glucose tolerance test.
Preparation and Properties of Fluorenylidene(phenyl)phosphines Bearing Bulky Groups with Electron-Donating Substituents in the Ortho Position on the Phenyl Group
Authors: Kawasaki Subaru , Fujita Takuma , Toyota Kozo , Yoshifuji Masaaki
Published: June 2005

Fluorenylidene(phenyl)phosphines having bulky substituents with an electron-donating group in the o-position on the phenyl group were prepared and their properties were compared. The prepared materials included 2,4-di-t-butyl-6-methoxyphenyl, 2,4-di-t-butyl-6-(phenoxymethyl)phenyl, 2,4-di-t-butyl-6-(dimethylamino)phenyl, or 2,4-di-t-butyl-6-(2-phenylethyl)phenyl. The diphosphenes and dithioxophosphoranes bearing the 2,4-di-t-butyl-6-(phenoxymethyl)phenyl group that formed were observed by 31P NMR spectroscopy; the effects of the substituent on these multiply bonded phosphorus species are discussed.
Syntheses of Glucose-Containing Lipid A Analogues and Their LPS-Antagonistic Activities
Authors: Shiozaki Masao , Doi Hiromi , Tanaka Daisuke , Shimozato Takaichi , Kurakata Shin-ichi
Published: June 2005

Three anomeric pairs of lipid A-type disaccharides containing a glucose on their reducing end were synthesized, and their LPS-antagonistic activities were measured. The inhibitory activities (IC50) on the LPS-induced TNFα production of these six compounds (16α, 16β, 28α, 28β, 40α, and 40β) toward human whole blood cells were 0.35, 0.42, 2.37, 1.16, 2.89, and 7.70 nM, respectively.
Creation of Concave-Shaped Conformation in Crystal Structures Using an Iminodicarbonyl Linker. An Application to Solid-State Intramolecular [4 + 4] Photocycloaddition Reactions of 2-Pyridone Derivatives
Authors: Masu Hyuma , Ohmori Ken , Kishikawa Keiki , Yamamoto Makoto , Yamaguchi Kentaro , Kohmoto Shigeo
Published: June 2005

Single-crystal X-ray structures of 6 carboxamides possessing two units of 2-pyridone moieties connected with an iminodicarbonyl linker were examined to show the usefulness of this linker for the creation of concave-shaped conformation in crystal structures. In all cases, the carboxamides showed concave-shaped conformations in which two 2-pyridone moieties faced each other. Their solid-state [4 + 4] photocycloaddition was carried out, and their reactivity was considered based on geometrical parameters (distances, angles, and torsion angles) obtained from the single-crystal X-ray analysis.
An Efficient Synthetic Method of 1-(2,4,6-Tri-t-butylphenyl)-3-phenyl-1-phosphaallenes [Mes*P=C=CR–Ph; R = H, SiMe3] from Dibromophosphaethene [Mes*P=CBr2] (Mes* = 2,4,6-t-Bu3C6H2)
Authors: Ito Shigekazu , Sekiguchi Satoshi , Freytag Matthias , Yoshifuji Masaaki
Published: June 2005

2-Bromo-3-phenyl-1-(2,4,6-tri-t-butylphenyl)-3-trimethylsiloxy-1-phospha-1-propene reacted with t-butyllithium and chlorotrimethylsilane to afford 3-phenyl-1-(2,4,6-tri-t-butylphenyl)-1-phosphaallene and/or 3-phenyl-3-trimethylsilyl-1-(2,4,6-tri-t-butylphenyl)-1-phosphaallene through the elimination of lithium trimethylsiloxide or hexamethyldisiloxane. The molecular structure of the latter phosphaallene was confirmed by X-ray crystallography.
Time-Resolved Chemiluminescence of Luminol Induced by TiO2 Photocatalytic Reactions
Authors: Wu Xing-Zheng , Akiyama Keiko , Min Lingyue
Published: June 2005

The time-resolved chemiluminescence (CL) of luminol in TiO2 photocatalytic reactions is reported. Third-harmonic light of 355 nm from a Q-switched Nd:YAG laser was used as a UV light source, and CL was collected in the perpendicular direction to the excitation light by two lenses. After eliminating the scattering light, the CL was detected by a PMT and recorded on a digital oscilloscope. It was found that the CL of luminol induced by the photocatalytic reaction increased with time after the illumination of a pulse laser, and reached the maximum value at about 40–60 μs, then slowly decreased with time. The time-resolved CL intensity increased greatly in an oxygen-bubbled TiO2 suspension, while it decreased greatly in a He-bubbled one. The total CL intensity increased linearly with the concentration of TiO2. Scavengers of active oxygen species of •OH, •O2− and H2O2 were added into the suspension for studying the involvement of the active oxygen species. The experimental results suggest that more than about 30% of CL might have been caused by H2O2 over the total time period, while the possibility of •OH involvement was small. On the other hand, the addition of a scavenger of •O2− had a small effect on the CL in time period of 0–0.7 ms, and decreased the CL after 0.7 ms.
The Transethylation of Biphenyl with Diethylbenzenes over H-Y Zeolite
Authors: Jun Qiu , Komura Kenichi , Kubota Yoshihiro , Sugi Yoshihiro
Published: June 2005

The liquid-phase transethylation of biphenyl (BP) with diethylbenzenes (DEBZ; o-:m-:p- = 5:66:29) was investigated by the use of zeolites, Y (FAU), Beta (BEA), mordenite (MOR), and ZSM-12 (MTW). Because H-Y (H-FAU(11) with SiO2/Al2O3 = 11) was the most active among them, and we chose H-FAU(11) as a standard catalyst, and studied reaction parameters. Both the catalytic activity and the selectivity for 4,4′-diethylbiphenyl (4,4′-DEBP) were influenced by the reaction conditions. The selective formation of 4,4′-DEBP was observed at low temperatures; however, the selectivity for 4,4′-DEBP decreased with the temperature. The selectivity for 4,4′-DEBP in bulk products were lower than the case of encapsulated products. These results show that the catalysis occurred principally inside pores: 4,4′-DEBP was formed by the transethylation of BP and DEBZ inside the pores of H-Y zeolite. The resultant 4,4′-DEBP was easily isomerized to thermodynamically stable isomers, 3,4′- and 3,3′-DEBPs even at lower temperatures because the most acid sites of H-Y zeolite are inside large pores, and they are strong enough for the isomerization of 4,4′-DEBP. The shape-selective formation of 4,4′-DEBP at lower temperatures is due to the rapid diffusion of the least bulky isomer from the H-Y pores. DEBPs were polyethylated to polyethylbiphenyls (PEBPs), and deethylated to ethylbiphenyls (EBPs) by transethylation with DEBZ inside the pores.
Optical Properties of Novel 2,3-Dicyano-5-methyl-6H-1,4-diazepine Dyes in the Solid State
Authors: Horiguchi Emi , Matsumoto Shinya , Funabiki Kazumasa , Matsui Masaki
Published: June 2005

Novel nonplanar fluorescent dyes, 2,3-dicyano-7-methyl-6H-1,4-diazepines, were synthesized. The fluorescence intensity of 6-substituted 2,3-dicyano-5-[4-(diethylamino)styryl]-7-methyl-6H-1,4-diazepines in vapor-deposited film was on the order of the substituent at the 6-position: n-Bu, Et > t-Bu, H. That of 2,3-dicyano-5-[4-(dialkylamino)styryl]-6-ethyl-7-methyl-6H-1,4-diazepines in the solid state was on the order of the alkyl group: CH2(3,5-(di-t-Bu)C6H3) > Bn > Et. Thus, the fluorescence intensity in the solid state basically increased with the bulkiness of the substituents on the chromophoric system. X-ray structure analysis clearly showed that the substituent at the 6-position and the dialkylamino moiety should inhibit intermolecular interactions between the chromophores so as to enhance the fluorescence intensity in the solid state.
High-Performance of PVK-based Photorefractive Polymers by High-Temperature Casting
Authors: Tanaka Shin-ya , Horikawa Hiroshi , Komori Yasushi , Nagayama Norio , Yokoyama Masaaki
Published: June 2005

To achieve high performance in molecularly dispersed photorefractive polymer films, it is essential to have a large electro-optic coefficient (r33), which is obtained by orientating nonlinear optic (NLO) molecules in an external electric field applied across the film. We investigated high-temperature casting, which is a new material fabrication technique for this purpose. We found that samples prepared by casting at higher temperatures showed a larger value of r33, which was due to an increasing number of unpaired NLO molecules in the polymer matrix that were able to orientate in an external electric field. This was caused by releasing stable anti-parallel pairs that were formed between the NLO molecules due to their large dipole moment. Therefore, our samples showed a large improvement in their photorefractivity in four-wave mixing (FWM) experiments.
The Non-Rigid Group of Tetraamine Platinum(II) as a Wreath Product
Authors: Darafsheh M R , Farjami Y , Ashrafi A R
Published: June 2005

A non-rigid molecule group theory (NRG) in which the dynamical symmetry operations are defined as physical operations is a new field of chemistry. Balasubramanian, Smeyers, and Villa in a series of papers applied this notion to determine the character table of restricted NRG (r-NRG) of some molecules. For example, Balasubramanian computed the NRG of the triple equivalent nitro group rotation in 1,3,5-triamino-2,4,6-trinitrobenzene, and proved that the NRG of this molecule is a group of order 48 (see Chem. Phys. Lett., 398, 15 (2004)). In this work a theoretical method is described for calculating the symmetry group of non-rigid molecules consisting of a number of XYn (n = 2,3,...) groups attached to a rigid framework. The non-rigid group of the molecule is a wreath product of symmetry group of the rigid frame with the permutation group of the XYn group. This algebraic structure of NRG helps us to compute the classes and character tables using the GAP package, even for large groups. We apply this method to find the structure of the non-rigid group of tetraamine platinum(II) with the D2d ordinary point group. It has proved that this is a group of order 5184. The method can be generalized to apply to other non-rigid molecules.
Application of N,N,N′,N′-Tetrasubstituted 1,3-Bis(4-aminophenyl)azulenes to Hole-injecting Materials for Durable Organic EL Devices without Color Fade
Authors: Oda Mitsunori , Thanh Nguyen Chung , Ikai Masamichi , Kajioka Takanori , Fujikawa Hisayoshi , Taga Yasunori , Ogawa Satoru , Shimada Hiroko , Kuroda Shigeyasu
Published: June 2005

The title 1,3-bis(aminophenyl)azulenes were synthesized from 1,3-dihaloazulene in two steps involving the Suzuki cross-coupling with 4-bromophenylboronic acid and subsequent Pd-catalyzed amination. Their HOMO energy levels were estimated to be comparable to that of the widely used hole-injecting (HI) material, copper phthalocyanine. The application of these diamines to HL materials in organic electroluminescent (EL) devices was also studied as non-cyanine and non-polyamine substance.
Sesquiterpene Esters from the Fruits of Celastrus orbiculatus
Authors: Guo Yuanqiang , Li Xian , Xu Jing , Meng Dali , Li Yushan , Ohizumi Yasushi
Published: June 2005

Two new β-dihydroagarofuran sesquiterpene esters, 1β,2β,6α-triacetoxy-9α-cinnamoyloxy-β-dihydroagarofuran (1) and 1β,8β-diacetoxy-9β-cinnamoyloxy-2β-hexanoyloxy-β-dihydroagarofuran (2), and four known compounds (3–6) have been isolated from the fruits of Celastrus orbiculatus Thunb. Their structures were elucidated on the basis of spectroscopic data. In murine macrophage RAW264.7 cells, compounds 2 and 6 inhibited LPS-induced nitric oxide production with the IC50 values of 67.3 μM and 63.5 μM, respectively.
Regioregular Poly(p-alkoxyphenylene)s Prepared from Facile Solid-state Oxidative Coupling Polymerization
Authors: Bai Wei Bin , Zhan Cai Mao
Published: June 2005

By grinding 1,4-dialkoxybenzene with anhydrous FeCl3 powder using a glass pestle in a mortar at ambient and solvent-free condition, poly(p-phenylene)s (PPP) was obtained in high yield up to 90% in 30 min. The products were characterized by 1H NMR, 13C NMR, WAXD, and UV–vis and the regioregular structure was suggested. The solid-state oxidative coupling polymerization is a facile, time saving, “green-chemistry” method.
Simple and Efficient Ratiometric Fluorescent Probes for Near-neutral pH in Aqueous Solutions
Authors: Xiang Yu , Tong Ai-Jun
Published: June 2005

Two ratiometric fluorescent pH probes of 2,6-diaminopyridine (DAPD) and 2-amino-5,7-dimethyl-1,8-naphthyridine (ADMND), though simple-structured, show good sensitivity to near-neutral pH range (6.0–8.0) in aqueous solutions. Further studies indicate that the 2-amino groups on pyridine or naphthyridine ring play an important role in the pH-dependent fluorescence spectral properties of these dyes.
Effects of Anion Species on Deintercalation of Carbonate Ions from Hydrotalcite-like Compounds
Authors: Iyi Nobuo , Okamoto Kentaro , Kaneko Yoshiro , Matsumoto Taki
Published: June 2005

The deintercalation of carbonate ions from a hydrotalcite-like compound (MgAl-LDH) was investigated using salt-HCl mixed solutions with sodium salts containing various monovalent anion species. The deintercalation was influenced by the anion species, and the carbonate ions were deintercalated most easily for the system containing Cl− or Br− anions.
Nearly Isotropic Two-dimensional Sheets in a Partially Oxidized Co(Pc)(CN)2 Salt (Pc = phthalocyaninato)
Authors: Asari Takehiro , Ishikawa Manabu , Naito Toshio , Matsuda Masaki , Tajima Hiroyuki , Inabe Tamotsu
Published: June 2005

Nearly isotropic two-dimensional sheets of partially oxidized Co(Pc)(CN)2 units were observed to form in a salt with PXX (PXX = peri-xanthenoxanthene), [PXX]2[Co(Pc)(CN)2]·CH3CN. The crystal is semiconducting under ambient pressure but displays stable metallic behavior under high pressure.
Molecular Orientation of Self-assembled Monolayer of Octadecanethiol on Platinum Surface Studied by Femtosecond Broad-bandwidth Sum Frequency Generation Spectroscopy
Authors: Noguchi Hidenori , Ito Mikio , Uosaki Kohei
Published: June 2005

The molecular orientation in self-assembled monolayer (SAM) of octadecanethiol (ODT) on platinum surface prepared in ethanol solution was examined by broad-bandwidth sum frequency generation (BB-SFG) spectroscopy. The bands attributed to the CH3 symmetric and asymmetric stretching vibrational modes were observed in the SFG spectra. From the analysis of SFG intensity ratio of these two modes, the alkyl chain on platinum was found to be more perpendicular to the substrate than those on gold surface.
Silica Nanobeads-decorated Multi-walled Carbon Nanotubes by Vapor-phase Method
Authors: Fan Wugang , Gao Lian
Published: June 2005

We report a new concise route to prepare carbon nanotube–silica nanobeads composites. The assembly of silica beads and nanotube by vapor-phase method make these structures an excellent platform for the development of biosensors, or for optical, magnetic and catalytic applications.
Highly Enantioselective (S)-Homoproline-catalyzed Michael Addition Reactions of Ketones to β-Nitrostyrenes
Authors: Terakado Dai , Takano Masako , Oriyama Takeshi
Published: June 2005

Being catalyzed by (S)-homoproline a highly enantioselective organocatalytic Michael addition reaction of ketones to β-nitrostyrenes has been achieved.
Hydrothermal Synthesis of Highly Ordered Micropompon of Lanthanum Molybdate Nanoflakes
Authors: Xu Yun-Peng , Jiang Dan-Yu , Bu Wen-Bo , Shi Jian-Lin
Published: June 2005

A novel micrometer-scale spherical structure composed of nanoflakes, named micropompon, has been achieved in the La2(MoO4)3 system through a simple surfactant-free hydrothermal approach. Possible formation mechanisms for the nanoflakes and micropompons have been preliminarily discussed.
Comments
Authors: Wasow Bernard
Published: June 2005

To be considered for publication in the Comments section, letters should be relatively short—generally fewer than 1,000 words—and should be sent to the journal offices at the address appearing inside the front cover. The editors will choose which letters will be published. All published letters will be subject to editing for style and length.
Estimating population or group sensitivity and its precision from a set of individual d′
Authors: Bi Jian
Published: June 2005

A commonly used method of estimating population sensitivity is the so‐called averaged d ′ method. In this method, the arithmetic mean of a set of individual d ′ is usually taken as a population sensitivity estimator. This practice ignores the fact that the individual d ′ itself is an estimator with an inherent variance. For observations with different levels of precision, the arithmetic mean is not the best estimator of a population parameter. It may lead to an estimate with a large variation. Another fact, which is often ignored, is that the variance of individual d ′ involves both between‐ and within‐subject variations in a random effects model when population sensitivity and its level of precision are estimated. Failing to account for both components of variance leads to an underestimate of variation and an overestimate of precision for the estimator. In this paper a lognormal distribution rather than a normal distribution is assumed for individual sensitivity. An iterative weighting procedure is proposed for estimating population sensitivity on the log scale on the basis of a random effects model. An ordinary weighting procedure is proposed for estimating group sensitivity on the log scale on the basis of a fixed effects model. The levels of precision of population and group sensitivity estimators are also given. Numerical examples illustrate the estimation procedures.
Latent variable models for partially ordered responses and trajectory analysis of anger‐related feelings
Authors: Meulders Michel , Ip Edward H. , De Boeck Paul
Published: June 2005

A general framework is presented for the analysis of partially ordered set (poset) data. The work is motivated by the need to analyse poset data such as multi‐componential responses in psychological measurement and partially accomplished cognitive tasks in educational measurement. It is shown how the generalized loglinear model can be used to represent poset data that form a lattice and how latent‐variable models can be constructed by further specifying the canonical parameters of the loglinear representation. The approach generalizes a class of latent‐variable models for completely ordered data. We apply the methods to analyse data on the frequency and intensity of anger‐related feelings. Furthermore, we propose a trajectory analysis to gain insight into the response function of partially ordered emotional states.
Book Reviews
Authors: Macdonald Ranald R.
Published: June 2005

Preference, belief and similarity: Selected writings

By A. Tversky (edited by E. Shafir)

Cambridge, Mass.: MIT Press, 2004, Paper £38.95, IBSN 0 262 20144 5.
Multidimensional scale types and invariant multivariate statistics
Authors: Chiang Ching‐Yuan
Published: June 2005

This paper proposes an extension of the definition of one‐dimensional ordinal, interval, ratio, difference and absolute scales to the multidimensional case. The connection between measurement structures and statistical structures suggested in a previous paper is also extended to the multivariate case, and examples of invariance properties of multivariate functions and statistics are discussed.
Examining change in maximal reliability for multiple‐component measuring instruments
Authors: Raykov Tenko , Hancock Gregory R.
Published: June 2005

A method for examining change in maximal reliability for pre‐specified sets of congeneric measures when developing a multi‐component instrument is outlined. The approach is applicable for purposes of estimation and testing of gain or loss in the maximal reliability coefficient as a consequence of adding or dropping one or more measures from a homogeneous composite with uncorrelated errors, as well as when one is concerned with optimal component choice for highest increase or correspondingly smallest drop in maximal reliability. The method is compared with a procedure for ascertaining change in unweighted sum score reliability, and implications for instrument construction and revision are discussed. The approach is illustrated with a numerical example.
Ellipsometric Study of Critical-Angle Infrared ATR Spectroscopy with a Metal-Coated Elastomer Film Overlayer
Authors: Watanabe Atsuo
Published: June 2005

Experimentally obtained ellipsometry angles of the phase about reflecting layers, in an arrangement which put a PVAc layer between a gold-coated PET film and the reflecting surface of a Ge prism at an incident angle of 22.5 to 25.5°, were closest to simulated ellipsometry angles of the phase, under the assumption that the apparent density of the PVAc layer decreased to 77% normal density so that the apparent refractive index of the PVAc layer was 1.35, and the reflecting layers were separated by a gap of 20 nm. Infrared absorption spectra which were obtained by using these optical configurations coincided well with spectra derived by a spectroscopic simulation of the reflecting layers that assumed the decreased density of the PVAc layer and the gap layer when the thickness of the PVAc layer was less than 100 nm. Spectral absorbance of the PVAc obtained by this method with the use of p-polarization was enhanced more than 20-fold over one obtained by transmission.
Determination of Iron, Cobalt, Nickel, and Copper in Hafnium Fluoride by GF-AAS
Authors: Jaganathan James , Aggarwal Ishwar
Published: June 2005

This paper describes an analytical method for the quantitation of iron, cobalt, nickel, and copper at trace levels with graphite furnace-atomic absorption spectrometry (GF-AAS) without the use of any matrix modifier or preconcentration techniques. A solution of HfF4 (10%, w/v) in HF (24%) was used for this study. The detection limits for iron, cobalt, nickel, and copper were found to be 3, 1, 3, and 2 ppb, respectively. The average precision of measurements (% RSD) for all the elements was <10%.
X-Ray Photoelectron Spectroscopy Studies of Photochemical Changes in High-Performance Fibers
Authors: Hamilton Lois E. , Sherwood Peter M. A. , Reagan Barbara M.
Published: June 2005

The double bonds and aromaticity that impart high thermal stability in fibers often increase the absorption of LTV radiation, resulting in greater susceptibility to photodegradation. This study compares the resistance of three high-performance fibers (Nomex aramid, Kynol novoloid, and PBI) to accelerated light exposure. X-ray photoelectron spectroscopy (XPS) was used to evaluate the photochemical changes on the surfaces of the fibers. On the basis of the C 1 s core-level spectra and oxygen/carbon atomic ratios, the Nomex aramid fibers were photo-oxidized more rapidly than Kynol novoloid and PBI fibers. Similarly, Nomex aramid fibers exhibited more rapid strength losses than the other fibers. We propose that tautomerization inhibited photodegradation in the Kynol novoloid and PBI fibers. XPS core-level and valence-band spectra interpreted by ab initio calculations are shown to be valuable probes of photo-oxidation in fibers.
Polycyclic Aromatic Nitrogen Heterocycles. Part V: Fluorescence Emission Behavior of Select Tetraaza- and Diazaarenes in Nonelectrolyte Solvents
Authors: Tucker Sheryl A. , Acree William E. , Upton Christopher
Published: June 2005

Fluorescence emission spectra are reported for tricycloquinazoline, dibenzo[c,f][2,7]naphthyridine, dibenzo[a,c]phenazine, dibenz[b,h]-indeno[1,2,3de][1,6]naphthyridine, and dibenz[c,f]indeno[l,2,3ij]-[2,7]naphthyridine dissolved in organic nonelectrolyte solvents of varying polarity and acidity. Results of these experiments were used to screen PANHs for potential probe character. The effect of nitromethane as a selective quenching agent on both the unprotonated and protonated PANHs was also examined. Nitromethane was found to quench fluorescence emission of dibenzo[c,f][2,7]naphthyridine. Emission intensities of the remaining four PANHs, and of the three protonated PANHs for which emission spectra could be obtained, remained essentially constant and were not affected by nitromethane.
Solid-State Infrared Photoacoustic Spectra of Group 6B Metal Mixed Carbonyl-t-Butylisocyanide Complexes, M(CO)6-n(CNtBu)n(M = Cr, Mo, W; n = 1–3)
Authors: Li Hongqi , Butler Ian S.
Published: June 2005

Solid-state mid- and near-IR photoacoustic (PA) spectra have been measured at room temperature for the group 6B metal(0) mixed carbonyl- t-butylisocyanide complexes M(CO)6- n(CN tBu) n ( M = Cr, Mo, W; n = 1-3). Vibrational assignments are proposed for many of the observed bands. The PA spectra in the near-IR region (4600-3600 cm−1), where the binary v(CN) and v(CO) overtones and combinations absorb, are useful spectral fingerprints for these organometallic complexes.
Evaluation of Thermospray and Cross-Flow Pneumatic Nebulization as Means of Interfacing a Flame Infrared Emission (FIRE) Radiometer to a High-Performance Liquid Chromatograph
Authors: Tilotta David C. , Lam Christopher K. Y. , Busch Kenneth W. , Busch Marianna A.
Published: June 2005

A cross-flow pneumatic nebulizer and a thermospray nebulizer were each studied as a means of interfacing a flame infrared emission (FIRE) radiometer to a high-performance liquid chromatograph (HPLC). Both nebulizers introduced significant quantities of liquid mobile phase into the FIRE burner, necessitating modifications to the basic burner design and causing temperature changes in the hydrogen/air flame used as the FIRE source. Tailing in the trailing edge of the peak profiles was also observed with the use of pneumatic nebulization and attributed to dead volume present in the nebulizer spray chamber. Flame background caused by the combustion of carbon-containing mobile phases was also a problem, but could be avoided when the FIRE radiometer was operated in the carbon mode by using water as the mobile phase. Flame background from carbon-containing mobile phases could also be electronically subtracted by using a dual-channel, chlorine-specific FIRE radiometer to selectively determine mixtures of chlorinated hydrocarbons in the presence of a chlorine-free mobile phase. Background subtraction had the added advantage of improving the detection limits for organochlorine compounds by a factor of approximately 3. Detection limits for FIRE/HPLC using pneumatic nebulization and the single-channel FIRE radiometer in the carbon mode were estimated as 3.7 μg s−1 (5.5 × 102 μg) for acetic acid and 0.80 μg s−1 (1.2 × 102 μg) for ethanol with water as the mobile phase. FIRE/HPLC detection limits using thermospray nebulization and a dual-channel FIRE radiometer in the chlorine-specific mode were estimated as 6.2 μg s−1 (3.7 × 102 μg) for methylene chloride and 9.7 μg s−1 (5.8 × 102 μg) for carbon tetrachloride with a combustible mixture of 49% acetonitrile, 20% methanol, 30% water, and 1% acetic acid as the mobile phase.
FT-IR Microspectroscopy: Sample Preparation and Analysis of Biopolymers
Authors: Abbott Thomas P. , Felker Frederick C. , Kleiman Robert
Published: June 2005

Samples of seed, stem, woody, and proteinaceous tissue were examined by FT-IR microspectroscopy. Methods of mounting samples for examination are described. Either they were immersed in D2O, embedded in either paraffin wax, epoxy, or vinylidene chloride-acrylonitrile copolymer, or they were examined without an embedding matrix.
Simple Time-Resolved Fluorometer Based on a Nanosecond Digital Oscilloscope and a Diode-Pumped, Solid-State Laser
Authors: Basile Franco , Cardamone Anita , Grinstead Keith D. , Miller Karen J. , Lytle Fred E. , Caprara Andrea , Clark Chris D. , Héritier Jean-Marc
Published: June 2005

A simple time-resolved fluorometer is constructed with an all-solid-state-based, frequency-tripled, Q-switched, diode-pumped Nd:YLF laser as the excitation source. Signal processing is accomplished with a digital oscilloscope. Simplicity of operation and applicability to trace analysis and in time-resolved spectroscopy are demonstrated with this new instrument. The laser produces 2.5-ns pulses at 349 nm and is capable of kilohertz repetition rates. For every shot of the laser, the oscilloscope collects an entire fluorescence decay at a 1-ns digitizer resolution and can average these data at the maximum laser repetition rate. When one is operating at 1 kHz and signal averaging for one second, detection limits (S/N = 3) in the 10–100 pM region are obtained. Excited-state decays are collected for several enzymatic probes and quinine sulfate, providing lifetimes consistent with those obtained by established instruments.
Characterization of Polyurethane Foams by Mid-Infrared Fiber/FT-IR Spectrometry
Authors: de Haseth James A. , Andrews Jennifer E. , McClusky John V. , Priester Ralph D. , Harthcock Matthew A. , Davis Bradley L.
Published: June 2005

The use of a mid-infrared transmitting fiber to monitor the cure process of a polyurethane foam is described. A chalcogenide fiber was situated between the spectrometer and a remote detector, but passed through the center of a polyurethane foam. This fiber was used as an internal reflectance element to observe changes in the polyurethane curing process. The appearance and disappearance of absorbances in the NH-stretching, carbonyl stretching (free urea and urethane, hydrogen-bonded urethane, and monodentate and bidentate hydrogen-bonded urea), isocyanate, and isocyanurate regions were monitored. These changes provided information about the reaction kinetics and morphological development of the foam.
Sum Frequency Spectra in the C-H Stretch Region of Adsorbates on Iron
Authors: Maechling C. R. , Kliner D. A. V. , Klenerman D.
Published: June 2005

Infrared-visible sum frequency generation (SFG) was used to record vibrational spectra in the C-H stretch region of single monolayer Langmuir-Blodgett films of stearic acid, octadecylamine, and p-octadecylphenyl acetic acid on iron oxide, demonstrating the sensitivity of SFG to about 0.1 monolayer. Within our present signal-to-noise limitations, it was not possible to obtain SFG spectra of the aromatic C-H stretch in p-octadecylphenyl acetic acid or the N-H stretch in octadecylamine. Vibrational spectra in the C-H stretch region have also been obtained for chemically adsorbed monolayers of stearic acid and oleic imidazoline on iron oxide; however an undetermined fraction of these spectra result from hydrocarbon contamination. Finally, an SFG spectrum was obtained at a buried interface, that of p-octadecylphenyl acetic acid on iron oxide under water. The potential of SFG as a surface analytical tool is discussed.
Use of Near-Infrared Spectroscopy to Determine the Composition of High-Density/Low-Density Polyethylene Blend Films
Authors: Miller Charles E.
Published: June 2005

The ability of near-infrared (NIR) spectroscopy, combined with principal component regression (PCR), to nondestructively determine the blend ratio of high-density polyethylene (HDPE) and low-density polyethylene (LDPE) in extruded films is demonstrated. Results indicate that the NIR spectrum in the region 2100 to 2500 nm can be used to determine the HDPE mass percentage of 60–80- μm-thick film samples to within 2.5%, over a range of 0 to 100%. NIR spectral effects from scattering are important for the determination of the HDPE % for HDPE contents above 50%, and spectral effects from changes in the methyl group concentration and perhaps the PE crystallinity are important for the determination of the HDPE % for HDPE contents below 50%. In addition, a large variation between the spectra of replicate samples, probably caused by variations in the degree or direction of molecular orientation in the samples, was observed.
Potential of the Diffuse Reflectance Infrared Fourier Transform (DRIFT) Method in Paleontological Studies of Bones
Authors: Dauphin Y.
Published: June 2005

The possible range of variability in fossil bones is not well understood. The purpose of the present study is to demonstrate the usefulness of infrared spectrometry for quantitative and qualitative measurements of the relative abundance of preserved proteins. These criteria, correlated with the crystallinity of bones, can enable one to understand certain diagenetic processes.
Chemometric Data Analysis Using Artificial Neural Networks
Authors: Liu Ying , Upadhyaya Belle R. , Naghedolfeizi Masoud
Published: June 2005

The on-line measurement of chemical composition under different operating conditions is an important problem in many industries. An approach based on hybrid signal preprocessing and artificial neural network paradigms for estimating composition from chemometric data has been developed. The performance of this methodology was tested with the use of near-infrared (NIR) and Raman spectra from both laboratory and industrial samples. The sensitivity-of-composition estimation as a function of spectral errors, spectral preprocessing, and choice of parameter vector was studied. The optimal architecture of multilayer neural networks and the guidelines for achieving them were also studied. The results of applications to FT-Raman data and NIR data demonstrate that this methodology is highly effective in establishing a generalized mapping between spectral information and sample composition, and that the parameters can be estimated with high accuracy.
Near-IR Fiber-Optic Temperature Sensor
Authors: Lin Jie , Brown Chris W.
Published: June 2005

A fiber-optic temperature sensor based on the perturbations of near-IR water bands has been developed. These fiber-optic sensors are very simple and readily fabricated. Models for expressing temperature can be developed by linear regression (LR) of the absorbance at one selected wavenumber, by multilinear regression (MLR) of the absorbances at several selected wavenumbers, or by principal component regression (PCR) using entire spectra. The standard errors of prediction for temperature are 0.53 to 1.64°C for the LR model, 0.22 to 0.85°C for the MLR model, and 0.16 to 0.32°C for the PCR model over a temperature range of 5 to 85°C. Potentially, these fiber-optic sensors can be used in the remote sensing of temperature and in hostile electrical environments.
Comparison of Solution and Solid-Matrix Luminescence Parameters
Authors: Hurtubise R. J. , Ramasamy S. M.
Published: June 2005

A relatively large number of comparisons have been made between solution luminescence and solid-matrix luminescence parameters for several lumiphors adsorbed on a number of solid matrices. Comparisons have been made for both room-temperature and low-temperature fluorescence and phosphorescence quantum yields, fluorescence and phosphorescence lifetimes, and a variety of photophysical rate constants. The comparisons reveal that solid-matrix luminescence can give greater fluorescence and phosphorescence quantum yields in many cases at room temperature, compared to the corresponding solution quantum yields at low temperature. The comparisons of fluorescence and phosphorescence lifetimes and the photophysical rate constants for the lumiphors adsorbed on solid matrices and in solutions reveal new insights into the differences between solid-matrix luminescence and solution luminescence.
Time-Resolved Laser-Induced Fluorescence Study on Dyes Used in DNA Sequencing
Authors: Chang Kaisyang , Forcé R. Ken
Published: June 2005

Research on the time-resolved fluorescence of fluorescein isothiocyanate, NBD, tetramethylrhodamine isothiocyanate, and Texas Red—the dyes used for fluorescence-based DNA sequencing—is described. Mean fluorescence lifetimes in both aqueous buffer solution and 5.3%T, 4.8%C polyacrylamide gel were determined as a function of excitation wavelengths at 337, 470, and 550 nm and were found to be 3.5, 1.1, 2.5, and 4.3 ns; the detection limits are 10, 200, 200, and 200 amol for FITC, NBD, TEMR, and T. Red, respectively. Comparisons of fluorescence parameters between the conjugated dyes and the free dyes are also reported. Results on the optimization of the excitation source wavelengths to improve sensitivity and reduce background scattering in polyacrylamide gel are also reported. Time-resolved fluorescence was successfully applied to resolve spectral overlapping of emissions in both solution and in polyacrylamide gel.
Use of Fourier Transform Infrared/Attenuated Total Reflectance Spectroscopy for the Study of Surface Adsorption of Proteins
Authors: Fu Fen-Ni , Fuller Michael P. , Singh Bal Ram
Published: June 2005

The adsorption behavior of lysozyme and immunoglobulin G (IgG) onto a ZnSe crystal surface has been detected by the FT-IR/ATR technique. With this technique we are able to detect the protein adsorption process at a very low concentration (0.0005 mg/mL). The equation of Sperline et al. [Langmuir 3, 198 (1987)] was successfully applied to calculate the adsorption density of protein from an aqueous solution on a real-time basis. The monolayer formation of lysozyme was observed at a concentration range of 10−7 M to 10−5 M. A monolayer-to-multilayer adsorption transition of lysozyme was clearly observed from the adsorption isotherm plot at 35 μM. A differential adsorption density was observed for IgG that could be explained on the basis of its differential size and surface charge.
Determination of Hydroxyl Number in Polymers by Infrared Spectroscopy: Comparison of Near-IR and Mid-IR
Authors: Lee K. A. Bunding , Chylla Richard W. , Janota Timothy E.
Published: June 2005

A comparison of near-infrared (NIR) and mid-infrared (mid-IR) techniques for the determination of hydroxyl number in polyesters was made. Both of these analyses are faster and involve less exposure to irritating, highly toxic, and corrosive chemicals than the chemical analysis, although both techniques rely on developing calibration files. The mid-IR procedure consisted of making thin films of polymer on IR crystals by spin coating and taking transmission spectra. The program used for the analysis, Nicolet PLS Quant, compensated for the resulting indeterminate pathlength. The NIR procedure consisted of taking transmission spectra of the clear, viscous polymers in 4-mm cuvettes and using standard regression analysis of the spectra.
Aluminum, Titanium Boride, and Nitride Films Sputter-Deposited from Multicomponent Alloy Targets Studied by XPS
Authors: Onyiriuka Emmanuel C.
Published: June 2005

X-ray photoelectron spectroscopy (XPS or ESCA), combined with argonion sputter depth profiling, has been employed for the characterization of aluminum, titanium boride, and nitride films deposited by dc-magnetron sputtering from multicomponent alloy targets. The XPS results show that metallic Al, TiB2, and TiN films are formed by this method. However, depth profile results indicated substantial oxide contamination as high as 30 atomic % throughout the bulk of the films. Given the gross oxide contamination, multicomponent alloy target materials appear to be unsuitable for producing high-quality metal/metallic films for applications where electrical conductivity is a critical requirement.
Three-Dimensional Digital Confocal Raman Microscopy
Authors: Govil Anurag , Pallister David M. , Morris Michael D.
Published: June 2005

We describe an iterative image restoration technique which functions as digital confocal microscopy for Raman images. We deconvolute the lateral and axial components of the microscope point spread function from a series of optical sections, to generate a stack of well-resolved Raman images which describe the three-dimensional topology of a sample. The technique provides an alternative to confocal microscopy for three-dimensional microscopic Raman imaging.
Microscopic FT-IR Studies of Epoxy Adhesive Films on Chemically Treated Aluminum
Authors: Fondeur Fernando , Koenig J. L.
Published: June 2005

Microscopic reflection-absorption FT-IR spectra were obtained on epoxy adhesive films on treated and untreated aluminum. Compositional differences were observed across the interphase. The epoxy on the untreated Al showed a large amount of the curing agent and its salt form near the surface relative to the bulk. In the case of the anodized Al surfaces, less curing agent was found, along with a relatively large amount of unreacted epoxy. An additional carbonyl band was found in the untreated Al sample, probably due to reaction of the curing agent with surface water. These results indicate that the surfaces are inducing selective adsorption, leading to differences in the composition of the cured adhesive bond.