bluuebunny/crossref_metadata_2025 huggingface dataset:
A phenylenevinylene‐thiophene‐phenyleneethynylene copolymer: synthesis, characterization, and photovoltaic properties
Authors: Zou Yingping , Tan Zhan'ao , Huo Lijun , Li Yongfang
Published: January 2008

A phenylenevinylene‐thiophene‐phenyleneethynylene copolymer, poly{[1′,4′‐bis‐(thienyl‐vinyl)]‐2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylene‐vinylene‐alt‐1,4‐dioctyloxyl‐phenyleneethynylene}(PTPPV‐ PPE), was synthesized by the Sonogashira Pd‐catalyzed cross‐coupling reaction. The copolymer possesses higher thermal decomposition temperature (Td = 382°C) compared with poly{[1′,4′‐bis‐ (thienyl‐vinyl)]‐2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylene‐vinylene} (PTPPV). The absorption and photoluminescence (PL) peaks of PTPPV‐PPE solution and solid film locate in between those of the homopolymers of PTPPV and poly(1,4‐dioctyloxyl‐phenyleneethynylene) (PPE), and closer to that of PTPPV. Photovoltaic cell was fabricated based on the blend of PTPPV‐PPE and PCBM with a weight ratio of 1:1. The primary result shows an open circuit voltage (Voc) of 0.72 V which is higher than that of the PTPPV (0.67 V), and a power conversion efficiency (PCE) of 0.3% under the illumination of AM1.5, 100 mW/cm2 which is much better than that of PPEs. Copyright © 2008 John Wiley & Sons, Ltd.
Lymphadenopathy as the primary manifestation of malignant transformation in two patients with severe congenital neutropenia
Authors: Gamper Christopher J. , Takemoto Clifford M. , Schowinsky Jeffrey , Borowitz Michael J. , Horwitz Marshall S. , Strouse John J.
Published: January 2008

We present the cases of two patients with severe congenital neutropenia (SCN) who both developed generalized adenopathy. Although both had recent histories that placed infection high on the differential of causes for the adenopathy, biopsies demonstrated acute myeloid leukemia (AML) as the etiology. The risk of malignant transformation in SCN is known to be significantly elevated, and these cases illustrate the need for physicians of such patients to keep myelodysplastic syndrome (MDS) and AML high on the differential when patients manifest atypical symptoms. Pediatr Blood Cancer 2008;50:1072–1075. © 2008 Wiley‐Liss, Inc.
Effects of small molecule plasticizer on the coordination crosslinking reaction between acrylonitrile‐butadiene rubber and copper sulfate
Authors: Yuan Xiaofang , Shen Fei , Wu Guozhang , Wu Chifei
Published: January 2008

The effects of small molecule plasticizer of liquid acrylonitrile‐butadiene rubber (LNBR) on coordination crosslinking reaction between acrylonitrile‐butadiene rubber (NBR) and copper sulfate (CuSO4) were investigated. Attenuated total reflectance infrared (ATR‐IR), curing curves analysis, equilibrium swelling method, differential scanning calorimetry (DSC), tensile test, and scanning electron microscope (SEM) were used in this work. The ATR‐IR analysis showed that the peak of restricted CN is more explicit in NBR/CuSO4/LNBR system. The curing curve analysis showed that NBR/CuSO4/LNBR has higher torque. The results of equilibrium swelling method and DSC displayed that NBR/CuSO4/LNBR has higher crosslink density and glass transition temperature, respectively. And NBR/CuSO4/LNBR has stronger tensile strength and longer elongation at break from tensile test. SEM revealed the reasons that the NBR/CuSO4/LNBR has better mechanical properties. All the results showed that addition of an amount of LNBR to NBR/CuSO4 system could accelerate the coordination crosslinking reaction between NBR and CuSO4. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
The effects of curing cycles on properties of the epoxy system 3221/RH glass fabric composites
Authors: Xuhui Hong , Youqing Hua
Published: January 2008

In this work, the epoxy system 3221 and its glass fabric laminates were thermally cured under different curing temperatures. The curing degree of the resin was increased with elevated reaction temperature. Dynamic mechanical analysis was performed on the laminate coupons and glass transition temperature (Tg) and relative stiffness (E′) of composites were measured before and after soaked in distilled water at 70°C. A shift in glass transition temperature to higher values and the splitting of the tan δ curve were observed with extent of cure under dry conditions. Tg values shifted to lower temperatures after immersion. Under wet condition, the change in Tg1 was very small when the curing degree was up to 96%. The relative stiffness experienced a reduction both in initial modulus and the initial sharp drop temperature after immersion. It also suggested that the excessively high curing temperature (>130°C) had a negative effect on the retention of relative stiffness under wet condition. Both the interlaminar shear strength and dielectric properties of laminates were determined before and after immersion. The compared results demonstrated that the elevated curing temperature played a good influence on both of the properties before aged. However, for samples cured above 130°C, lower retention of interlaminar shear strength and poor dielectric properties were observed during immersion due to their higher moisture contents. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Microstructure changes in poly(ethylene terephthalate) in thick specimens under complex biaxial loading
Authors: Marco Yann , Chevalier Luc
Published: January 2008

We present an experimental investigation into the strain‐induced crystalline microstructure, under biaxial elongation in Polyethylene terephthalate (PET). The aim of our study is to achieve both mechanical tests representative from the blow‐moulding process, and micro‐ structural measurements. We therefore examine how the microstructure of a polymer subjected to a complex strain field evolves in terms of its crystalline ratio, its molecular orientation and the size of its crystallites. PET injection‐moulded thick specimens were subjected to bi‐axial elongation tests, both equibiaxial and sequential, using several elongation speeds, draw ratios and temperatures (above and close to Tg). The strain field was determined using a home‐developed image correlation technique that allowed us to identify all the strain components at each point of the specimen, even when the strain field was not homogeneous. After the completion of the strain path, the specimens were either quenched at room temperature or cooled down very quickly using liquid nitrogen, in order to dissociate the contribution of stretching from that of relaxation. Microstructure observations were achieved by means of differential densimetry and WAXD (Wide Angle X‐ray Diffraction) using a synchrotron beam. The results obtained confirm the strong link between the stress tensor and the crystals orientation and the crucial influence of molecular orientation on final microstructure (crystalinity ratio, crystals morphology). POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Palladium‐mediated polymerization of cyclic diazoketones
Authors: Ihara Eiji , Hiraren Toshimitsu , Itoh Tomomichi , Inoue Kenzo
Published: January 2008

Palladium‐mediated polymerization of cyclic diazoketones was investigated. Although cyclic diazoketones 1a,b derived from cyclohexanone and 1‐tetralone did not homopolymerize, they can be used as a comonomer for copolymerization with polymerizable acyclic diazoketones. On the other hand, an α,β‐unsaturated cyclic diazoketone 2a prepared from 2‐cyclohexen‐1‐one polymerized to give a polymer poly2a′ with Mn = 1400 in a 23.8% yield. Addition of some nucleophiles to CC bond in poly2a′ was carried out. Copolymerization of 2a and its dimethyl‐substituted analogues 2b,c with acyclic diazoketones was also investigated. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1638–1648, 2008
Functionalization and molecular dynamics study of carboxy‐terminated poly(1‐vinylpyrrolidin‐2‐one): A potential soluble carrier of biomolecules
Authors: Baldoli Clara , Oldani Claudio , Maiorana Stefano , Ferruti Paolo , Ranucci Elisabetta , Bencini Marco , Contini Alessandro
Published: January 2008

The reactivity of carboxy‐terminated poly(1‐vinylpyrrolidin‐2‐one) (PVP‐COOH) 40‐mers 1 with various small bi‐functionalized molecules has been investigated. A number of new differently functionalized PVP 3–11 have been successfully obtained demonstrating that the presence of the bulky PVP chain did not hamper the reactivity of the carboxy group. This would imply that in solution the carboxyl group is not buried inside the coil, but well exposed to the solvent, as further confirmed by a molecular dynamics conformational study. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1683–1698, 2008
Divergent synthesis and self‐assembly of amphiphilic polymeric dendrons with selective degradable linkages
Authors: Urbani Carl N. , Lonsdale Daria E. , Bell Craig A. , Whittaker Michael R. , Monteiro Michael J.
Published: January 2008

Enhancing the structural complexity and functionality of the building blocks allows the construction of supramolecular assemblies. In this work, we demonstrate a strategy for the design and synthesis of complex macromolecular architectures. We use atom transfer radical polymerization to produce well‐defined polymers with telechelic end‐group functionality, and “click” them together to form functional 3rd generation dendrons, and incorporated degradable linkages and certain functionality at the polymer chain‐ends of each generation. The 3rd generation polymeric dendrons consisted of homopolymer polystyrene (PSTY) with either four solketals or eight alcohols, diblock PSTY and poly(t‐butyl acrylate), and amphiphilic diblock. The peripheral ends consisting of alcohols create functionalization points for further chemical modification or chemical coupling and the cleavable linkages between the 2nd and 3rd generations all provide the first steps toward smart nanostructures. Importantly, we can synthesize these dendrons in pure form. The self‐assembly of the amphiphilic dendrons (the inner and outer generations consisting of PSTY and polyacrylic acid, respectively) in water produced micelles of uniform size with an aggregation number of 43 dendrons per micelle. The size of the micelles was small (DH =20.7 nm) and comparable to the size found by transmission electron microscopy (14–18 nm). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1533–1547, 2008
A couples intervention for patients facing advanced cancer and their spouse caregivers: outcomes of a pilot study
Authors: McLean Linda M. , Jones Jennifer M. , Rydall Anne C. , Walsh Andrew , Esplen Mary Jane , Zimmermann Camilla , Rodin Gary M.
Published: January 2008

Objective: The primary objective of this study was to evaluate the effectiveness of a couples intervention in improving marital functioning in advanced cancer patients and their spouse caregivers. A secondary objective was to determine its impact on other symptoms of psychosocial distress and its feasibility and acceptability as a clinical intervention.

Methods: Using a one‐arm pre‐ and post‐intervention prospective design, 16 couples were provided 8 weekly sessions of Emotionally Focused Couple Therapy, modified and manualized for the cancer population. Subjects' marital functioning (Revised Dyadic Adjustment Scale [RDAS]), symptoms of depression (Beck Depression Inventory‐II [BDI‐II]), and hopelessness (Beck Hopelessness Scale) were assessed through self‐report at T0 (baseline), T1 (after four sessions), T2 (after eight sessions), and T3 (3 months post‐intervention follow‐up).

Results: RDAS scores improved from T0 to T2, with 87.5% of the couples showing some improvement (0.5–5 points) or significant improvement (>5 points) in marital functioning and 68.8% scoring in the non‐distressed range (⩾48 RDAS). At T3, 60% of the couples (n=15) continued to score in the non‐distressed range on the RDAS. BDI‐II scores were significantly higher for patients than for caregivers. There was a significant reduction in the mean BDI‐II score from T0 to T3 in all subjects (n=30). This reduction was more significant for the patients (n=15).

Conclusions: Providing support to couples at this challenging time may result in improved marital functioning and an opportunity for relational growth during end‐stage cancer. This study serves as the first step in the development of an empirically validated intervention for couples. Copyright © 2008 John Wiley & Sons, Ltd.
Chromosome 8q24 risk variants in hereditary and non‐hereditary prostate cancer patients
Authors: Sun Jielin , Lange Ethan M. , Isaacs Sarah D. , Liu Wennuan , Wiley Kathleen E. , Lange Leslie , Gronberg Henrik , Duggan David , Carpten John D. , Walsh Patrick C. , Xu Jianfeng , Chang Bao‐Li , Isaacs William B. , Zheng S. Lilly
Published: January 2008

Background

Multiple variants in three regions at 8q24 are consistently found to be associated with prostate cancer (PCa) risk in population‐based association studies. The role that these variants may play in familial prostate cancer risk has not been extensively investigated.

Methods

We evaluated 12 SNPs at three 8q24 regions using population‐based association and family‐based linkage and association methods in hereditary PCa (HPC) probands and their families, non‐HPC patients, and unaffected screened controls, all recruited at Johns Hopkins Hospital.

Results

For multiple variants in Region 1 (e.g., rs1447295) and Region 2 (e.g., rs16901979), we found statistically significantly higher frequencies of previously identified risk alleles and genotypes in HPC probands than in unaffected controls. Furthermore, in Region 2 the risk alleles were statistically significantly more frequent in HPC probands than in non‐HPC patients. Family‐based transmission tests found risk alleles of SNPs in Region 2, but not in Regions 1 and 3, were significantly over‐transmitted to affected men in these families. We found little evidence supporting PCa linkage at 8q24 in 168 HPC families, in part explained by the observation of multiple, different risk allele‐containing haplotypes segregating in the vast majority of these families.

Conclusions

Our study further supports the presence of PCa susceptibility loci at 8q24, particular at Region 2, and also provides evidence that these SNPs play an important role in familial prostate cancer. Large family‐based studies are needed to confirm our novel findings. Prostate 68: 489–497, 2008. © 2008 Wiley‐Liss, Inc.
A density functional study of CoCn (n = 1–8) clusters: Structures and stabilities
Authors: Redondo Pilar , Barrientos Carmen , Largo Antonio
Published: January 2008

A theoretical study of the different linear, fan and cyclic CoCn (n = 1–8) clusters has been carried out. Predictions for their electronic energies, rotational constants, dipole moments, and harmonic vibrational frequencies have been made using the B3LYP method with the 6‐311+G(d) basis set. Doublet and quartet lowest‐lying states have been found for neutral CoCn clusters. The stability of linear, fan, and cyclic structures as a function of the size of the cluster has been discussed in terms of the incremental binding energies. Only fan structures show a clear even‐odd alternation in stability. The incremental binding energies exhibit small changes along the series in the case of linear isomers, whereas for cyclic ones decrease along the series. It is also found that for the small CoCn clusters in general, the linear‐type structures are more stable than the fan and cyclic ones. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
A formula for the Kirchhoff index
Authors: Bendito Enrique , Carmona Angeles , Encinas Andres M. , Gesto Jose M.
Published: January 2008

We show here that the Kirchhoff index of a network is the average of the Wiener capacities of its vertices. Moreover, we obtain a closed‐form formula for the effective resistance between any pair of vertices when the considered network has some symmetries, which allows us to give the corresponding formulas for the Kirchhoff index. In addition, we find the expression for the Foster's n‐th formula.
Transition probabilities found for M + CH4 reactions (M = zinc, copper)
Authors: Pacheco‐Sánchez Juan Horacio , Novaro Octavio
Published: January 2008

Transition probabilities between the lowest energy levels of M + CH4 (M = Zn, Cu) reactions were obtained through nonadiabatic crossings using a modification of the Landau–Zener (L–Z) theory. Hartree Fock self consistent field (HF‐SCF) ab initio calculations were utilized to obtain the reaction pathways by means of the PSHF program, while pseudopotentials for representing the core–core and core‐valence interaction were applied. The correlation energy is taken into account by means of multireference variational and perturbative configuration interaction calculations to second order using CIPSI code. The variational space generated in iterative manner includes more than 250 determinants, while the perturbative space is about 3 × 107 configurations. The perturbative contribution is about 40% of the total correlation energy recovered. The time dependent L–Z theory was developed through the reaction coordinate r (distance). An extension of the latter theory to the reaction coordinate θ (angle) was used in this case. Then, the nonadiabatic crossings depend on both the angular velocity and the moment of inertia, among other things. The transition probability of the system HMCH3 (M = Zn, Cu) leading from one energy level to another is calculated through an avoided crossing. This method has been previously tested on gallium‐methane and gallium‐silane reactions for which the theoretical probability transitions between potential energy surfaces of gallium‐methane reactions agree with experimental quenching branching fractions with great accuracy. © 2008 Wiley Periodicals, Inc., 2008
Theoretical study of the electronic spectra of bi‐ and tri‐heteronuclear platinum complexes
Authors: Mendizabal Fernando
Published: January 2008

The electronic structure and the spectroscopic properties of [Pt(NH3)4][Au(CN)2]2, [Pt(NH3)4][Ag(CN)2]2, [Pt(CNCH3)4][Pt(CN)4], and [Pt(CNCH3)4][Pd(CN)4] were studied at the HF, MP2, B3LYP, and PBE levels. In all the complexes, it was found that the nature of the intermetal interactions is consistent with the presence of a high‐ionic contribution (90%) and a dispersion‐type interaction (10%). The absorption spectra of these complexes were calculated by the single‐excitation time‐dependent (TD) method at the HF, B3LYP, and PBE levels. The [Pt(NH3)4][M(CN)2]2 (M  Au, Ag) complexes showed a 1(dσ* → pσ) transition associated with a metal–metal charge transfer. On the other hand, the [Pt(CNCH3)4][M(CN)4] (M  Pt, Pd) complexes showed a 1(dσ* → π*) transition associated with a metal‐to‐metal and ligand charge transfer. The values obtained theoretically are in agreement with the experimental range. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Binding of pyruvate dehydrogenase to the core of the human pyruvate dehydrogenase complex
Authors: Korotchkina Lioubov G. , Patel Mulchand S.
Published: January 2008

In human (h) pyruvate dehydrogenase complex (PDC) the pyruvate dehydrogenase (E1) is bound to the E1‐binding domain of dihydrolipoamide acetyltransferase (E2). The C‐terminal surface of the E1β subunit was scanned for the negatively charged residues involved in binding with E2. βD289 of hE1 interacts with K276 of hE2 in a manner similar to the corresponding interaction in Bacillus stearothermophilus PDC. In contrast to bacterial E1β, the C‐terminal residue of the hE1β does not participate in the binding with positively charged residues of hE2. This latter finding shows species specificity in the interaction between hE1β and hE2 in PDC.
Differential epigenetic regulation of Aiolos expression in human tumoral cell lines and primary cells
Authors: Duhamel Marianne , Navarro Pablo , Cario-Andre Muriel , Billot Katy , Arrouss Issam , Rebollo Angelita
Published: January 2008

In order to investigate the epigenetic component of Aiolos regulation, we analyzed the methylation status of its 5′ CpG island in relation to histone modifications. Inhibition of CpG methylation restores Aiolos expression, as well as euchromatin‐associated markers, in U937 and 1106 mel cell lines. DNA methylation and low levels of euchromatin‐associated signatures are observed in U937 and 1106 mel cell lines, while the opposite characterizes Daudi, Jurkat, T and B cells. CpG methylation is not necessary to repress transcription in monocytes and melanocytes where silencing mechanism involves heterochromatin‐associated signature. We show that DNA methylation directs Aiolos silencing and chromatin status in tumor cell lines, while in primary cells is mainly regulated by histone modifications.
GAUSSIAN INFERENCE IN AR(1) TIME SERIES WITH OR WITHOUT A UNIT ROOT
Authors: Phillips Peter C.B. , Han Chirok
Published: January 2008

This paper introduces a simple first-difference-based approach to estimation and inference for the AR(1) model. The estimates have virtually no finite-sample bias and are not sensitive to initial conditions, and the approach has the unusual advantage that a Gaussian central limit theory applies and is continuous as the autoregressive coefficient passes through unity with a uniform
$\sqrt{n}$
rate of convergence. En route, a useful central limit theorem (CLT) for sample covariances of linear processes is given, following Phillips and Solo (1992, Annals of Statistics, 20, 971–1001). The approach also has useful extensions to dynamic panels.
Themenschwerpunkt: Die gerontopsychiatrische Konsiliarpsychiatrie
Authors: Kratz Torsten , Diefenbacher Albert
Published: January 2008

Zusammenfassung. Gerade bei älteren Patienten, die einen erheblichen Anteil der Einweisungen im Allgemeinkrankenhaus ausmachen, werden körperliche Erkrankungen häufig von psychischen Symptomen und Verhaltensauffälligkeiten begleitet. Umgekehrt weisen viele körperliche Beschwerden auch auf das Vorliegen einer larvierten psychischen Erkrankung hin. Aus diesem Grund hat in den letzten Jahren die Bedeutung der gerontopsychiatrischen Konsiliarpsychiatrie und Psychotherapie am Allgemeinkrankenhaus deutlich zugenommen. Der vorliegende Artikel beschäftigt sich neben der Begriffsbestimmung der gerontopsychiatrischen Konsiliarpsychiatrie und Psychotherapie mit deren Besonderheiten am Allgemeinkrankenhaus. Besonderer Wert wird auf die im Alter erhöhte Anzahl an somato-psychiatrischer Komorbidität, Multimorbidität, Polypharmazie, besondere Arzneimittelinteraktionen, psychosoziale Isolierung und das hohe Suizidrisiko gelegt. Es sollen Probleme, Arbeitsfelder und Chancen der Entwicklung der gerontopsychiatrischen Konsiliarpsychiatrie und Psychotherapie am Allgemeinkrankenhaus aufgezeigt werden.
Gerontopsychiatrie
Authors: Förstl Hans
Published: January 2008

Zusammenfassung. Gerontopsychiatrie ist jener Bereich der modernen Psychiatrie, der die engsten Beziehungen zu den somatischen Fächern der Medizin aufweist. Einige zentrale und zukunftsträchtige Themen der gerontopsychiatrischen Diagnostik und Therapie sind in diesem Themenschwerpunkt versammelt: Schlafmittelabhängigkeit, Delir, Parkinson, Demenz mit Lewy-Körperchen, frontotemporale Degeneration, nicht-kognitive Symptome bei der Alzheimer-Demenz, vor allem Apathie, systemische Therapie und Probleme der Konsiliarpsychiatrie.
Systemische Therapie in der Gerontopsychiatrie
Authors: Johannsen Johannes
Published: January 2008

Zusammenfassung. Systemische Therapie/Familientherapie bei älteren Menschen ist immer dann vorrangig indiziert, wenn das auffällige Verhalten bzw. die psychische Störung eines älteren Menschen mit seinen familiären Beziehungen oder seinem sonstigen Bezugssystem im Zusammenhang steht. Ausgehend von einer typischen Beziehungskonstellation mit einer älteren depressiv erkrankten Patientin im Zentrum des Geschehens werden zunächst die Grundzüge der systemischen Therapie und anschließend die Modifikationen des psychotherapeutischen Verfahrens bei Beteiligung älterer Menschen beschrieben. Besonders werden der Überweisungskontext, die Klärung des Behandlungsauftrags und das oft mehrere Generationen umfassende Beziehungsgefüge sowie die Ankopplung an das System dargestellt. Der Nutzen des Genogramms wird erwähnt. Des weiteren wird auf die zu erkennenden Wirklichkeitskonstruktionen, die Vorstellungen und Bilder vom Altern, häufig auftretende Themen des Alters und das ressourcenorientierte Vorgehen eingegangen.
Themenschwerpunkt: Die Delirbehandlung im Alter
Authors: Thomas Christine
Published: January 2008

Zusammenfassung: Das Delir im Alter stellt eine häufige und folgenreiche Komplikation internistischer und chirurgischer Erkrankungen dar und verursacht, obwohl potenziell vermeidbar, erhebliche Folgekosten. Neben den delirbegünstigenden Faktoren Alter, Multimorbidität und sensorischer Einschränkung kommt Delirauslösern wie Infektionen, Exsikkose, Operationen und zentral-anticholinerg wirksamer Medikation eine entscheidende Bedeutung zu. Die Diagnose erfolgt auf DSM-IV oder der strengeren ICD10-Basis, unterstützt durch Screening-Tests und das EEG. Eine evidenzbasierte Behandlung des Delirs stellt zunächst die Therapie und Vermeidung auslösender Faktoren und Komplikationen in den Vordergrund. Eine Symptombehandlung mit Haloperidol ist lediglich bei Hyperaktivität, Selbstgefährdung und Angst indiziert. Cholinesterasehemmer zeigen ebenfalls positive Effekte, insbesondere bei komorbider Demenz. Benzodiazepine gelten als Mittel zweiter Wahl. Die Delirprävention ist als Qualitätsmerkmal der Behandlung älterer Menschen anzusehen.
Regional model simulation of North Atlantic cyclones: Present climate and idealized response to increased sea surface temperature
Authors: Semmler Tido , Varghese Saji , McGrath Ray , Nolan Paul , Wang Shiyu , Lynch Peter , O'Dowd Colin
Published: January 2008

The influence of an increased sea surface temperature (SST) on the frequency and intensity of cyclones over the North Atlantic is investigated using two data sets from simulations with the Rossby Centre regional climate model RCA3. The model domain comprises large parts of the North Atlantic and the adjacent continents. RCA3 is driven by reanalysis data for May to December 1985–2000 at the lateral and lower boundaries, using SST and lateral boundary temperatures. A realistic interannual variation in tropical storm and hurricane counts is simulated. In an idealized sensitivity experiment, SSTs and boundary condition temperatures at all levels are increased by 1 K to ensure that we can distinguish the SST from other factors influencing the development of cyclones. An increase in the count of strong hurricanes is simulated. There is not much change in the location of hurricanes. Generally weaker changes are seen in the extratropical region and for the less extreme events. Increases of 9% in the count of extratropical cyclones and 39% in the count of tropical cyclones with wind speeds of at least 18 m/s are found.
Regional estimation of parameters of a rainfall‐runoff model at ungauged watersheds using the “spatial” structures of the parameters within a canonical physiographic‐climatic space
Authors: Hundecha Yeshewatesfa , Ouarda Taha B. M. J. , Bárdossy András
Published: January 2008

A regionalization scheme by which parameters of a continuous rainfall‐runoff model are estimated from physiographic and climatic watershed descriptors is presented. The approach makes use of the spatial structures displayed by the parameters within a physiographic‐climatic space defined on the basis of a canonical correlation analysis between model parameters and watershed descriptors. Traditionally, regionalization has been performed using a two‐step procedure of first estimating the model parameters in a set of subwatersheds independently and then establishing a relationship between the parameters thus estimated and a set of watershed descriptors. The approach presented in this paper follows a procedure by which the two steps are combined into one. The model is calibrated for the training subwatersheds with a dual objective of maximizing the model performance and achieving well‐defined spatial structures of the parameters within the physiographic‐climatic space. The model parameters in the subwatersheds that are not used for training are estimated from the optimum parameters obtained in the training set of subwatersheds using ordinary kriging within the physiographic‐climatic space. The performance of the model in these subwatersheds is comparable to the performance in the training set obtained using the optimum parameters estimated through model calibration. The results also indicate the possibility of extrapolation of the model parameters under a situation where some of the watershed descriptors lie slightly outside the range within which the training was done.
Effects of intercontinental transport on surface ozone over the United States: Present and future assessment with a global model
Authors: Lin Jin‐Tai , Wuebbles Donald J. , Liang Xin‐Zhong
Published: January 2008

Future changes in intercontinental transport (ICT) of European and Asian (EURA) pollutants can have substantial consequences on U.S. pollution. This is investigated with 27 simulations using a newly improved version of the Model for OZone And Related chemical Tracers to simulate ICT contributions to summertime U.S. surface ozone for 1999, 2049 and 2099, with future climate and emissions perturbations following the Intergovernmental Panel on Climate Change A1fi and B1 scenarios. We find that projected ICT changes are primarily affected by changes in EURA anthropogenic emissions, whose increases under A1fi lead to 3–8 ppb, 2–6 ppb due to Asian emissions increases alone, more ozone from 1999 to both 2049 and 2099 over the western U.S.; whereas EURA emissions changes under B1 lead to 0–0.7 ppb and 1–2 ppb less ozone by 2049 and 2099, respectively. Therefore global, especially Asian, emission control is important for U.S. pollution mitigation.
Iron in the Japan Sea and its implications for the physical processes in deep water
Authors: Takata Hyoe , Kuma Kenshi , Isoda Yutaka , Otosaka Shigeyoshi , Senjyu Tomoharu , Minagawa Masayuki
Published: January 2008

Labile dissolved Fe (DFe, <0.22 μm fraction) and total dissolvable Fe (TDFe, unfiltered) were examined throughout the water column of the northeastern (Japan Basin) and mid‐eastern (Yamato Basin) basin regions in the Japan Sea. We observed extremely high vertically integrated TDFe inventories and low nutrient concentrations at the surface water in both basins, probably resulting from high atmospheric Fe input to nutrient‐depleted surface water. DFe in both basins was characterized by mid‐depth maxima and, below that, a slight decrease with depth in deep water and uniform concentration in bottom water. In the Japan Basin, surprisingly, TDFe concentrations in bottom water were lower than those in deep water, resulting from the injection of new bottom water. On the contrary, TDFe concentrations in bottom water of the Yamato Basin increased gradually with depth and were higher than those in deep water probably due to the supply of iron during the horizontal transport of the bottom water in the Japan Basin towards the Yamato Basin. The TDFe with a high percentage of labile particulate Fe (TDFe minus DFe) may have important implications for understanding the physical processes of bottom water in the Japan Sea.
Thermospheric dark band structures observed in all‐sky OI 630 nm emission images over the Brazilian low‐latitude sector
Authors: Pimenta A. A. , Kelley M. C. , Sahai Y. , Bittencourt J. A. , Fagundes P. R.
Published: January 2008

Using two ground‐based all‐sky imaging systems, measurements of moving dark band structures in the OI 630.0 nm nightglow emission were detected in the low‐latitude region of Brazil. On the nights of 30–31 August 1995, 18–19 July 1998, and 13–14 July 1999, the all‐sky imaging observations of the OI 630 nm emission, carried out at Cachoeira Paulista (22.7°S, 45°W, magnetic declination 20°W), Brazil, showed dark band structures that stretched across the entire image and propagated from southeast to northwest. The observed band structures are thus most likely formed in the midlatitude region and move into the field of view. Digisonde observations, available for two of the events, registered abrupt increases in both the F‐layer peak height (hmF2) and minimum virtual height (h'F) on 19 July 1998 and 13 July 1999, when the low‐intensity band passed over Cachoeira Paulista. It should be pointed out that these thermospheric events are not related to geomagnetic disturbed conditions, as the nights for which data are presented are geomagnetically quiet (Kp < 2). In this paper we present and discuss the first observations of these thermospheric dark band structures in the Brazilian sector and their effects on the nighttime ionosphere. A possible mechanism for generation of these dark band structures is presented.
An Interplanetary Weather Forecast for Mars
Authors: Ladbury Ray
Published: January 2008

Astronomers are used to seeing strange things when they turn their telescopes toward the Red Planet—some of them tantalizingly, and often deceptively, Earthlike. The image above, a stereographic projection centered on Mars's north pole, was returned by the Hubble Space Telescope Wide-Field Planetary Camera 2 on 27 April. It depicts a “spiral storm” 1600 km in diameter (the storm is a diffuse white spiral to the left of the bright ice cap) just south of the planet's northern polar ice cap. Although such Storms were first observed over 20 years ago, April's tempest was three to four times the size of previously observed storms. So far detected only in Mars's northern hemisphere during its summer, the storms bear some resemblance to terrestrial polar cyclones.
Model Sheds Light on a Tragedy and a New Type of Eruption
Authors: Ladbury Ray
Published: January 2008

For severed hours on the night of 21 August 1986, a massive jet of gas and water erupted from Lake Nyos, a remote, deep volcanic lake in the uplands of northwestern Cameroon in West-Central Africa. Reaching a height of over 100 meters, the heavy, lethal gas displaced the air below it and swept down the slope, asphyxiating 1746 people in the villages below the lake.
Galileo's Probe Sends a Weather Report from Jupiter
Authors: Ladbury Ray
Published: January 2008

A nalyzing data from the Galileo spacecraft, which has been orbiting Jupiter since 7 December 1995, is not a job for those who require instant gratification. Delayed for three years after the Challenger disaster, the spacecraft then spent six years in its 3-billion-kilometer journey to the Solar System's largest planet. Moreover, because Galileo's high-gain antenna never fully unfurled, the spacecraft must instead transmit data using its low-gain antenna—at the glacially slow rate of a few tens of bits per second. When one knows as little about a system as we do about Jupiter, however, a trickle of data can unleash a flood of new results. The most recent results, based on in situ measurements of Jupiter's atmosphere and innermost magnetosphere by Galileo's probe, have raised questions about the giant planet's composition, even as they have resolved some fundamental questions about the driving force of the zonal, or east-west, winds that give rise to the planet's banded appearance. Because of Jupiter's large size, and because it is thought to have a near-protosolar composition, these results may have important implications not just for our understanding of Jupiter and similar planets, but also for our ideas on the formation and evolution of the Solar System.
… And Io Yields Still More Surprises
Authors: Ladbury Ray
Published: January 2008

Researchers have come to expect spectacular surprises from Io, the innermost of Jupiter's Galilean satellites. The Voyager missions revealed Io to be the most volcanically active object in the Solar System. Voyager also revealed the importance of Io's interactions with Jupiter's magneto-sphere, which generate a potential of 400 kV across the moon's diameter and currents of over a million amperes between Io and Jupiter's ionosphere. As a result of this past performance, researchers eagerly waited for Galileo to pass within 900 km of Io, a factor of 20 closer than any of Voyager's flyby's. Initial analysis of the data indicates that, once again, Io has not disappointed.
Martians Invaded Earth 13 000 Years Ago—Maybe
Authors: Ladbury Ray
Published: January 2008

Okay, never mind that what may have been humankind's first encounter with extraterrestrial life didn't have the drama of The War of the Worlds, independence Day or even My Favorite Martian. Never mind that toy companies are now trying to figure out how to bid for the rights to and then market toys patterned after submicrometer-long extraterrestrial bacteria. What is important is for us to understand the chain of scientific reasoning that has led to the claim that the Allan Hills (ALH) 84001 meteorite may contain fossil evidence of life from Mars.
Upconversion in Nd3+-doped glasses: Microscopic theory and spectroscopic measurements
Authors: Oliveira S. L. , de Sousa D. F. , Andrade A. A. , Nunes L. A. O. , Catunda T.
Published: January 2008

In this work, we report a systematic investigation of upconversion losses and their effects on fluorescence quantum efficiency and fractional thermal loading in Nd3+-doped fluoride glasses. The energy transfer upconversion (γup) parameter, which describes upconversion losses, was experimentally determined using different methods: thermal lens (TL) technique and steady state luminescence (SSL) measurements. Additionally, the upconversion parameter was also obtained from energy transfer models and excited state absorption measurements. The results reveal that the microscopic treatment provided by the energy transfer models is similar to the macroscopic ones achieved from the TL and SSL measurements because similar γup parameters were obtained. Besides, the achieved results also point out the migration-assisted energy transfer according to diffusion-limited regime rather than hopping regime as responsible for the upconversion losses in Nd-doped glasses.
Applications of the generalized Lüders theorem
Authors: Du Hong-Ke , Wang Yue-Qing , Xu Jun-Lian
Published: January 2008

In this paper, we prove that the main results in a more recent paper [S. Gudder, “Duality quantum computers and quantum operations,” Int. J. Theor. Phys. (in press)] also hold on a separable complex Hilbert space. The proofs in the present paper have been completed by using the block operator technique which are different from that in Gudder’s paper on the unitary freedom theorem of the finite dimensional setting.
Electrical and optical properties of phosphorus-doped p-type ZnO films grown by metalorganic chemical vapor deposition
Authors: Pan X. H. , Jiang J. , Zeng Y. J. , He H. P. , Zhu L. P. , Ye Z. Z. , Zhao B. H. , Pan X. Q.
Published: January 2008

P-doped p-type ZnO thin films have been grown by metalorganic chemical vapor deposition. By modulating the P evaporating temperature, p-type conductivity can be controlled due to the different P content incorporated into the ZnO films. The P-doped p-type ZnO thin films are of high optical quality, as indicated by low-temperature photoluminescence. P-related acceptor state with an energy level of 163 meV is identified from free-to-neutral-acceptor transitions. In addition, x-ray photoelectron spectroscopy confirms that only one chemical bonding state of P exists in the P-doped ZnO thin films.
Nanocrystalline material development for high-power inductors
Authors: Long Jianguo , McHenry Mike , Urciuoli Damian P. , Keylin Vladimir , Huth Joe , Salem Thomas E.
Published: January 2008

A new high-saturation induction, high-temperature nanocomposite alloy for high-power inductors is discussed. This material has FeCo with an A2 or B2 structure embedded in an amorphous matrix. An alloy of composition Fe56Co24Nb4B13Si2Cu1 was cast into a 1.10in. wide, 0.001in. thick ribbon from which a toroidal core of approximately 4.25in. outer diameter, 1.38in. inner diameter, and 1.10in. tall was wound. The core was given a 2T transverse magnetic field anneal, and impregnated for strength. Field annealing resulted in a linear B-H response with a relative permeability of 1400 that remained constant up to field strengths of 1.2T. The core was used to construct a 25μH inductor for a 25kW dc-dc converter. The inductor was rated for operation in discontinuous conduction mode at a peak current of 300A and a switching frequency of up to 20kHz. Compared to commercially available materials, this new alloy can operate at higher flux densities and higher temperatures, thus reducing the overall size of the inductor.
Formation of metallic clusters in oxide insulators by means of ion beam mixing
Authors: Talut G. , Potzger K. , Mücklich A. , Zhou Shengqiang
Published: January 2008

The intermixing and near-interface cluster formation of Pt and FePt thin films deposited on different oxide surfaces by means of Pt+ ion irradiation and subsequent annealing was investigated. Irradiated as well as postannealed samples were investigated using high resolution transmission electron microscopy. In MgO and Y:ZrO2 covered with Pt, crystalline clusters with mean sizes of 2 and 3.5nm were found after the Pt+ irradiations with 8×1015 and 2×1016cm−2 and subsequent annealing, respectively. In MgO samples covered with FePt, clusters with mean sizes of 1 and 2nm were found after the Pt+ irradiations with 8×1015 and 2×1016cm−2 and subsequent annealing, respectively. In Y:ZrO2 samples covered with FePt, clusters up to 5nm in size were found after the Pt+ irradiation with 2×1016cm−2 and subsequent annealing. In LaAlO3 the irradiation was accompanied by a full amorphization of the host matrix and appearance of embedded clusters of different sizes. The determination of the lattice constant and thus the kind of the clusters in samples covered by FePt was hindered due to strong deviation of the electron beam by the ferromagnetic FePt.
Giant magnetoresistance and tunnel magnetoresistance effects in FeCoGd-based spin valves and magnetic tunnel junctions
Authors: Bai X. J. , Du J. , Zhang J. , You B. , Sun L. , Zhang W. , Wu X. S. , Tang S. L. , Hu A. , Hu H. N. , Zhou S. M.
Published: January 2008

Giant magnetoresistance (GMR) and tunnel magnetoresistance (TMR) were studied in spin valves of FeCo∕Cu∕(FeCo)1−xGdx and magnetic tunnel junctions of FeCo∕AlO∕(FeCo)1−xGdx, respectively. When the FeCoGd layer is thick enough, both GMR and TMR ratios change their signs from positive to negative at the compensation composition with 0.293⩽x0⩽0.337 as the Gd content is increased. This scenario is originated from a competition of rare-earth and transition-metal spins in FeCoGd layers with antiferromagnetic coupling. Accordingly, it is deduced that in the FeCoGd layer the spin polarizations PN of electrons at the Fermi level and tunneling spin polarization PTSP are negative and positive for xx0.
Strain effect on the transport properties in low-doped La0.9Hf0.1MnO3 epitaxial films
Authors: Wang L. , Gao J.
Published: January 2008

La 0.9 Hf 0.1 Mn O 3 thin films with different thicknesses are epitaxially grown on SrTiO3 (100) single-crystal substrates by using pulsed laser deposition. X-ray diffraction shows that these thin films are of single phase and highly epitaxial. The influence of film thickness on the resistivity and metal-insulator transition is studied in various magnetic fields. The magnetoresistive properties of these La0.9Hf0.1MnO3 films are similar to those of other doped LaMnO3 manganites. The metal-insulator transition temperature (Tp) is developed by decreasing the film thickness from 400to150nm. The Tp associated with conductivity increases as the thickness is reduced. The effect of lattice deformation and oxygen deficiency is analyzed to explain the observed phenomena.
The Hahn polynomials in the nonrelativistic and relativistic Coulomb problems
Authors: Suslov Sergei K. , Trey Benjamin
Published: January 2008

We derive closed formulas for mean values of all powers of r in nonrelativistic and relativistic Coulomb problems in terms of the Hahn and Chebyshev polynomials of a discrete variable. A short review on special functions and solution of the Coulomb problems in quantum mechanics is given.
Carrier induced magnetic anomalies in Mn-doped AgGaSe2 magnetic semiconductor
Authors: Yoshino Kenji , Kinoshita Aya , Shirahata Yasuhiro , Ikari Tetuo , Taniyama Tomoyasu
Published: January 2008

Magnetic behaviors of the magnetic semiconductor Mn-doped AgGaSe2 with no secondary phases are reported. Magnetization measurements show that Mn-doped AgGaSe2 exhibits a superparamagnetic behavior while undoped AgGaSe2 shows diamagnetism. Significant anomalies are also seen in the temperature dependent ac susceptibility and specific heat at 190 and 275K. These results indicate that the substitution of Mn induces magnetism in AgGaSe2. The origin of the magnetic behaviors is discussed on the basis of the combined results of susceptibility, specific heat, and photoluminescence.
Polarization optimization of spin-echo small angle scattering instruments
Authors: Rekveldt M. Theo , Duif Chris P. , Kraan Wicher H. , Plomp Jeroen , Bouwman Wim G.
Published: January 2008

The polarization optimization in a small angle scattering spin-echo setup is considered, under the depolarization and phase errors that occur in field transition regions by improper adjustment of inclined magnetized foils as π-flippers. Various correction procedures are discussed. In these setups with precession fields perpendicular to the beam directions, corrections can be reduced strongly by the use of π-flippers, and for the remaining errors, correction coils can be constructed.
Modulation of hard x-ray beam profiles by Borrmann pyramid
Authors: Xu G. , Britten J.
Published: January 2008

Spatial modulation of hard x-ray beam profiles is reported, using the “Borrmann pyramid” formed in dual Bragg diffraction of a single crystal, where a small angular change of the incident beam is magnified to span the entire pyramid base. As an attempt, it is demonstrated using hard x rays by (1) the linear shift of a micrometer sized mask; (2) the partial blockade of a two micron beam; and (3) the millimeter shadow of a nanoscale gold strip, which shows the potential application of Borrmann pyramids in the form of an enlarged x-ray image.
Green laser emission from monolithic II-VI-based pillar microcavities near room temperature
Authors: Kruse Carsten , Lohmeyer Henning , Sebald Kathrin , Gutowski Jürgen , Hommel Detlef , Wiersig Jan , Jahnke Frank
Published: January 2008

We report on single-mode stimulated emission at a wavelength of 510nm in monolithic high-Q ZnSe-based vertical-cavity surface-emitting laser (VCSEL) micropillars under optical excitation at 280K. Calculations reveal the influence of polariton coupling and the dynamic detuning of the gain maximum to the cavity modes on the spectral characteristics of the VCSEL emission. In accordance with theory, we find a systematic decrease in threshold excitation energy for decreasing pillar diameter to a minimum value of 0.09pJ for a pillar diameter of 1.2μm as a combined effect of reduced active area and reduced mode volume in the microcavity lasers.