bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vibrational properties of InP under pressure: a molecular‐dynamics study
Authors: Branício Paulo S. , Rino José P. 
Published: November 2006

AbstractDynamical properties of InP in the zincblende (ZB) are investigated using isothermal–isobaric molecular‐dynamics simulations based on a proposed interaction potential for InP consisting of two‐ and three‐body terms. The two‐body term represents steric repulsion, Coulomb interactions due to charge transfer, induced charge–dipole interaction, and van der Waals dipole–dipole interaction. The three‐body term represents covalent bond bending and stretching. The model is fitted to reproduce crystalline lattice constant, cohesive energy, and the structural transition pressure from ZB to rocksalt. The effects of hydro‐ static pressure and temperature on the vibrational density‐of‐states, phonon anharmonicity, dynamic Debye–Waller factor, thermal expansion coefficient are described as well as the pressure induced structural phase transformation. Results are consistent with available experimental data, in particular the calculated equation of state and phonon density‐of‐states have very good agreement. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐pressure Raman study on type‐I germanium clathrate
Authors: Fukushima T. , Kume T. , Sasaki S. , Shimizu H. , Fukuoka H. , Yamanaka S. 
Published: November 2006

AbstractRaman scattering measurements of the type‐I Ge clathrtate, Ba8Ge43, have been performed at 1 bar and room temperature, and under high‐pressures up to 22 GPa. Because of vacancies which exist in Ba8Ge43, the Raman spectrum at 1 bar was found to be different from that of Si clathrate. Low‐frequency vibrational modes associated with Ba atoms were found around 35–75 cm–1 and the Ge‐framework Raman bands were observed around 80–150 cm–1 comparable to the typical clathrate Ba8Si46. For these regions, spectral shapes are very similar to that of Ba8Si46. However, for the region above 150 cm–1, all the peaks were considerably weak in intensity, in contrast to Ba8Si46. In the data obtained at high pressures, the spectral changes were observed around 8.0 GPa and 22 GPa. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman study of semiconductor clathrates under high pressure
Authors: Kume T. , Fukushima T. , Sasaki S. , Shimizu H. , Fukuoka H. , Yamanaka S. 
Published: November 2006

AbstractIn order to gain an insight into the mechanism of the isostructural phase transition observed previously for Ba8Si46 compound, the high pressure Raman experiments have been performed for clathrate compounds of Ba8Au6Si40 and Ba8Ge3Si43 derivative from Ba8Si46 by substituting Si with other atoms. The Ba8Ge3Si43 clathrate indicated the occurrence of the phase transition at the same pressure as Ba8Si46 but, the Ba8Au6Si40 did not show up to 27 GPa. The present results suggest that a particular crystal site (6c site) plays an important role for the phase transition of the clathrate compounds. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitation and pressure effects on photoluminescence from dislocation engineered silicon material
Authors: Ishibashi Y. , Kobayashi T. , Prins A. D. , Nakahara J. , Lourenco M. A. , Gwilliam R. M. , Homewood K. P. 
Published: November 2006

AbstractWe report the influence of excitation wavelength and pressure effects on the photoluminescence (PL) of silicon light‐emitting diode material fabricated by boron ion implantation. The PL spectra show an anomalous increase in total intensity as temperature elevates, and this luminescence is found to be strongest with decreasing laser penetration depth away from the sample surface. The PL peak position shifts towards lower energy at a rate of –14 meV/GPa with increasing pressure. This rate agrees with earlier optical measurements on the band‐edge absorption of silicon, confirming that this luminescence is closely related to phonon‐assisted indirect band gap transitions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low‐temperature electrical conductivity of heavily boron‐doped diamond single crystals
Authors: Blank V. D. , Buga S. G. , Terentiev S. A. , Kuznetsov M. S. , Nosukhin S. A. , Krechetov A. V. , Kul'bachinski V. A. , Kytin V. G. , Kytin G. A. 
Published: November 2006

AbstractSingle crystal diamonds 0.2–0.7 cm large doped with boron concentration 1019–1020 cm–3 were grown by temperature gradient method on the seed under pressure P = 5.5 GPa, temperature T = 1650 K. Temperature dependence of electrical resistance had been measured in the range of 0.5–297 K. Boltzmann activation type of conductivity and Mott's VRH law observed in samples in the temperature ranges ∼200–297 K and ∼70–297 K respectively. The temperature rise of conductivity in the range of ∼0.5–50 K for most heavily doped crystals was proportional to T 1/2. This rule indicates the vicinity of the electronic system to metal–insulator transition. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pressure‐induced insulator–metal transition in a novel layer metalloorganic structure
Authors: Ovsyannikov Sergey V. , Shchennikov Vladimir V. , Titov Alexander N. , Uwatoko Yoshiya 
Published: November 2006

AbstractA novel layer metalloorganic structure (Co(η5‐C5H5)2)0.25TiSe2has been synthesized by intercalation of the cobaltocene, Co(η5‐C5H5)2[bis(eta‐5‐cyclopentadienyl)cobalt] (a representative of the metallocenes M(η5‐C5H5)2where M – is a metal) into van‐der‐Waals gaps of TiSe2matrix. The papers reports a study of the electrical resistanceR, thermoelectric powerS(Seebeck effect), and contraction of a sample's thickness (compressibility) under almost continuous variation of quasihydrostatic pressurePwithin 0–20 GPa at room temperature. We observed a gradual decrease ofR(P) by ∼8 orders to 20 GPa. AboutP∼ 10 GPa we established both an abrupt change of dR/dPand inversion ofSfrom the electronic to the holes type of conductivity. ToP∼ 16 GPa the intercalate became a metal and exhibited a “close to zero”S, which was kept down to 8 GPa on decompression; all pressure‐induced changes were reversible. The synthesized compound (Co(η5‐C5H5)2)0.25TiSe2is a novel functional material for wide application. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural phase transformations in InP under pressure: A molecular‐dynamics study
Authors: Rino José Pedro , Branício Paulo S. 
Published: November 2006

AbstractThe pressure induced structural phase transformations of InP up to 100 GPa are investigated using molecular‐dynamics simulations. The calculated InP equation of state for the zincblende (ZB) phase at room temperature is in excellent agreement with experiments as well as several thermodynamic properties validating the interatomic potential employed in the simulations. Results show a sequence of dynamic structural transformations from ZB → rocksalt (RS) at 10 GPa, from RS → rhombohedral (RH) at 14 GPa, and from RH → CsCl at 70 GPa. The RS → RH transformation is a weakly first order transition while the other two transformations are typical first order transitions which present large volume drop and hysteresis in the reverse transformation. The RH intermediate phase between RS and CsCl was never considered for InP even though it was predicted for other materials. The ZB → RS transition uses a Pmm2 pathway while the RS → RH → CsCl is consistent with the Buerger mechanism which uses the R$ \bar 3 $m pathway. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Anisotropy analysis of the surface stress in Ag stepped surfaces with the modified embedded atom method
Authors: Shu Yu , Zhang Jian‐Min , Xu Ke‐Wei 
Published: November 2006

AbstractThe surface stresses in Ag stepped surfaces (910), (710), (510), (410), (310), (210), (320), (430) and (540) have been calculated by using the modified embedded atom method (MEAM). The surface stresses in the surface plane τxx (along the step edge) and τyy (normal to the step edge) have similar orders of magnitude as the surface energy. For surfaces having the (100) and (110) terraces, the change of τxx and τyy is very small and the variation of the surface energy is smooth. The stress τzz (normal to the surface plane) is always tensile in the unrelaxed state. The linear variation of the change in surface energy per unit change in elastic strain ${\partial \gamma\over \partial \varepsilon_{xx}}$, ${\partial \gamma\over \partial \varepsilon_{yy}}$ and ${\partial \gamma\over \partial \varepsilon_{zz}}$ (i.e. τxx − γ, τyy − γ and τzz) with the angle α between the (hk0) and (100) planes has a turning point corresponding to the (210) surface. The anisotropic ratio in the stepped surface having the (110) terrace is larger than that having the (100) terrace, and the wider the (110) terrace or the narrower the (100) terrace, the larger the ratio τyy/τxx. Copyright © 2006 John Wiley & Sons, Ltd.
Reaction of imidazole in gas phase at very low pressure with Cu foil and Cu oxides studied by X‐ray photoelectron spectroscopy
Authors: Hernández M. P. , Fernández‐Bertrán J. F. , Farías M. H. , Díaz J. A. 
Published: November 2006

AbstractThe gas‐phase reactions of imidazole with Cu foil, CuO and Cu2O powders at a pressure of 10−5 Torr are studied by means of X‐ray photoelectron spectroscopy (XPS) at room temperature for 1 h. The reactivity of gaseous imidazole is very intense with Cu foil, weak with CuO and nil with Cu2O. The reaction product on the Cu foil is cuprous imidazolate of oligomeric nature and with CuO is cupric imidazolate of very low molecular weight. Copyright © 2006 John Wiley & Sons, Ltd.
An approach to joint analysis of longitudinal measurements and competing risks failure time data
Authors: Elashoff Robert M. , Li Gang , Li Ning 
Published: November 2006

AbstractJoint analysis of longitudinal measurements and survival data has received much attention in recent years. However, previous work has primarily focused on a single failure type for the event time. In this paper we consider joint modelling of repeated measurements and competing risks failure time data to allow for more than one distinct failure type in the survival endpoint which occurs frequently in clinical trials. Our model uses latent random variables and common covariates to link together the sub‐models for the longitudinal measurements and competing risks failure time data, respectively. An EM‐based algorithm is derived to obtain the parameter estimates, and a profile likelihood method is proposed to estimate their standard errors. Our method enables one to make joint inference on multiple outcomes which is often necessary in analyses of clinical trials. Furthermore, joint analysis has several advantages compared with separate analysis of either the longitudinal data or competing risks survival data. By modelling the event time, the analysis of longitudinal measurements is adjusted to allow for non‐ignorable missing data due to informative dropout, which cannot be appropriately handled by the standard linear mixed effects models alone. In addition, the joint model utilizes information from both outcomes, and could be substantially more efficient than the separate analysis of the competing risk survival data as shown in our simulation study. The performance of our method is evaluated and compared with separate analyses using both simulated data and a clinical trial for the scleroderma lung disease. Copyright © 2006 John Wiley & Sons, Ltd.
A residuals‐based transition model for longitudinal analysis with estimation in the presence of missing data
Authors: Koru‐Sengul Tulay , Stoffer David S. , Day Nancy L. 
Published: November 2006

AbstractWe propose a transition model for analysing data from complex longitudinal studies. Because missing values are practically unavoidable in large longitudinal studies, we also present a two‐stage imputation method for handling general patterns of missing values on both the outcome and the covariates by combining multiple imputation with stochastic regression imputation. Our model is a time‐varying autoregression on the past innovations (residuals), and it can be used in cases where general dynamics must be taken into account, and where the model selection is important. The entire estimation process was carried out using available procedures in statistical packages such as SAS and S‐PLUS. To illustrate the viability of the proposed model and the two‐stage imputation method, we analyse data collected in an epidemiological study that focused on various factors relating to childhood growth. Finally, we present a simulation study to investigate the behaviour of our two‐stage imputation procedure. Copyright © 2006 John Wiley & Sons, Ltd.
Kernel support for zero‐loss Internet service restart
Authors: Chang Da‐Wei , Tsai Chuan‐Ming , Li Wei‐Kou , Lee Tzu‐Rung 
Published: November 2006

AbstractOwing to long serving time and huge numbers of clients, Internet services can easily suffer from transient faults. Although restarting a service can solve this problem, information of the on‐line requests will be lost owing to the service restart, which is unacceptable for many commercial or transaction‐based services. In this paper, we propose an approach to achieve the goal of zero‐loss restart for Internet services. Under this approach, a kernel subsystem is responsible for detecting the transient faults, retaining the I/O channels of the service, and managing the service restart flow. In addition, some straightforward modifications to the service should be made to take advantage of the kernel support. To demonstrate the feasibility of our approach, we implemented the subsystem in the Linux kernel. Moreover, we modified a Web server and a CGI program to take advantage of the kernel support. According to the experimental results, our approach incurs little runtime overhead (i.e. less than 3.2%). When the service crashes, it can be restarted quickly (i.e. within 210 μs) with no information loss. Furthermore, the performance impact due to the service crash is small. These results show that the approach can efficiently achieve the goal of zero‐loss restart for Internet services. Copyright © 2006 John Wiley & Sons, Ltd.
Profiling with AspectJ
Authors: Pearce David J. , Webster Matthew , Berry Robert , Kelly Paul H. J. 
Published: November 2006

AbstractThis paper investigates whether AspectJ can be used for efficient profiling of Java programs. Profiling differs from other applications of AOP (e.g. tracing), since it necessitates efficient and often complex interactions with the target program. As such, it was uncertain whether AspectJ could achieve this goal. Therefore, we investigate four common profiling problems (heap usage, object lifetime, wasted time and time‐spent) and report on how well AspectJ handles them. For each, we provide an efficient implementation, discuss any trade‐offs or limitations and present the results of an experimental evaluation into the costs of using it. Our conclusions are mixed. On the one hand, we find that AspectJ is sufficiently expressive to describe the four profiling problems and reasonably efficient in most cases. On the other hand, we find several limitations with the current AspectJ implementation that severely hamper its suitability for profiling. Copyright © 2006 John Wiley & Sons, Ltd.
A brokerage system for solar data archives
Authors: Zunino C. , Pompili I. , Sanna A. , Ciminiera L. 
Published: November 2006

AbstractScientific research and practical applications of solar physics require data and computational services to be integrated seamlessly and efficiently. The European Grid for Solar Observations (EGSO) leverages Grid‐oriented concepts and technology to provide a high‐performance infrastructure for solar applications. In this paper, an architecture for a data brokerage service is proposed. Brokers interact with providers and consumers in order to build a profile of both parties. In particular, a broker interacts with providers in order to gather information on the data potentially available to consumers, and with the consumers in order to identify the set of providers that are most likely to satisfy specific data needs. The brokerage technique is based on a multi‐tier management of metadata. Copyright © 2006 John Wiley & Sons, Ltd.
Toward a progress indicator for program compilation
Authors: Luo Gang , Chen Tong , Yu Hao 
Published: November 2006

AbstractFor user‐friendliness purposes, many modern software systems provide progress indicators for long‐running tasks. These progress indicators continuously estimate the percentage of the task that has been completed and when the task will finish. However, none of the existing program compilation tools provide a non‐trivial progress indicator, although it often takes minutes or hours to build a large program. In this paper, we investigate the problem of supporting such progress indicators. We first discuss the goals and challenges inherent in this problem. Then we present a set of techniques that are sufficient for implementing a simple yet useful progress indicator for program compilation. Finally, we report on an initial implementation of these techniques in GNU Make. Copyright © 2006 John Wiley & Sons, Ltd.
A new algorithm for encoding and decoding the Hilbert order
Authors: Chen Ningtao , Wang Nengchao , Shi Baochang 
Published: November 2006

AbstractAn iterative algorithm is described, based on the replication process of the Hilbert matrix, for encoding and decoding the Hilbert order. The time complexity of the proposed algorithm is smaller than those published previously, and the space complexity is bounded by a constant. Moreover, the new algorithm has a wider applicability when compared with existing algorithms for certain machine‐word lengths. A new variant of the Hilbert curve is suggested to overcome a shortcoming of the traditional Hilbert curve for the mapping problem. The proposed coding algorithms for the traditional Hilbert curve are also applicable to the new variant without increasing the time and space complexities. Copyright © 2006 John Wiley & Sons, Ltd.
Three‐dimensional sonographic determination of normal fetal mandibular and maxillary size during the second half of pregnancy
Authors: Roelfsema N. M. , Hop W. C. J. , Wladimiroff J. W. 
Published: November 2006

AbstractObjectiveTo explore the various ways of obtaining fetal maxillary and mandibular size with three‐dimensional (3D) ultrasound, with a view to developing a tool for identifying minor anomalies in the lower facial region.MethodsSerial 3D sonographic measurements of the fetal jaws were made in 126 normal singleton pregnancies at 18–34 weeks of gestation for determination of degree of maxillary and mandibular protrusion, maxillary and mandibular corpus lengths, mid‐ and lower facial depths and maxillary and mandibular curvature. In a sub study the reproducibility of the measurements was evaluated.ResultsThe coefficient of variation in the reproducibility study varied between 7.1 and 10.5%. For all parameters except maxillary and mandibular protrusion, there was a significant gestational age‐related increase. Ratios of maxillary/mandibular protrusion, maxillary/mandibular corpus lengths, mid‐/lower facial depths and maxillary/mandibular curvature all showed a significant gestational age‐related decrease, with the most distinct decrease in the mid‐/lower facial depth ratio.Conclusions3D sonographic measurement of the fetal maxilla and mandible demonstrated an acceptable intraobserver variability for all measurements. The mid‐/lower facial depth ratio appears to be most valuable in determining abnormal mandibular development. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Correlation between prenatal ultrasound and autopsy findings: a study of second‐trimester abortions
Authors: Kaasen A. , Tuveng J. , Heiberg A. , Scott H. , Haugen G. 
Published: November 2006

AbstractObjectiveTo evaluate discrepancies between sonographic and autopsy findings following termination of pregnancy (TOP) in the second trimester.MethodsThis retrospective report is based on 288 consecutive second‐trimester abortions carried out because of fetal malformations diagnosed by ultrasound examination at a tertiary referral center. The correlation between the results from the ultrasound and autopsy examinations was evaluated.ResultsAutopsy was performed in 274 cases. In 160 of the 274 pregnancies (58.4%) there was full agreement between the two examination methods. Findings detected by autopsy (in addition to those leading to termination) were not observed by ultrasonography in 86 (31.4%) of the pregnancies; of the 64 malformations that occurred, 30 (46.9%) were judged as ‘detectable’. In 27 (9.9%) pregnancies, observations made by ultrasound (in addition to those leading to termination) were not confirmed at autopsy. In one pregnancy, postmortem radiology examination—but not autopsy—confirmed the ultrasound observations. No pregnancies were terminated because of false positive ultrasound observations. The correlation between ultrasound and autopsy findings was evaluated by three investigators; the inter‐rater agreement was high (κ = 0.85).ConclusionDiscrepancies between ultrasound and autopsy findings were observed in about 40% of the pregnancies. These discrepancies confirm the need for autopsy following TOP. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Comparison of alternative models for personality disorders
Authors: MOREY LESLIE C. , HOPWOOD CHRISTOPHER J. , GUNDERSON JOHN G. , SKODOL ANDREW E. , SHEA M. TRACIE , YEN SHIRLEY , STOUT ROBERT L. , ZANARINI MARY C. , GRILO CARLOS M. , SANISLOW CHARLES A. , McGLASHAN THOMAS H. 
Published: November 2006

Background. The categorical classification system for personality disorder (PD) has been frequently criticized and several alternative dimensional models have been proposed.Method. Antecedent, concurrent and predictive markers of construct validity were examined for three models of PDs: the Five-Factor Model (FFM), the Schedule for Nonadaptive and Adaptive Personality (SNAP) model and the DSM-IV in the Collaborative Study of Personality Disorders (CLPS) sample.Results. All models showed substantial validity across a variety of marker variables over time. Dimensional models (including dimensionalized DSM-IV) consistently outperformed the conventional categorical diagnosis in predicting external variables, such as subsequent suicidal gestures and hospitalizations. FFM facets failed to improve upon the validity of higher-order factors upon cross-validation. Data demonstrated the importance of both stable trait and dynamic psychopathological influences in predicting external criteria over time.Conclusions. The results support a dimensional representation of PDs that assesses both stable traits and dynamic processes.
Modelling outbreak control for pneumonic plague
Authors: MASSIN L. , LEGRAND J. , VALLERON A. J. , FLAHAULT A. 
Published: November 2006

SUMMARYAlthough pneumonic plague is listed by the Centers of Disease Control in the leading ‘critical biological agents’, very few studies exist on this subject. In this study, a mathematical compartment model was used to describe the geographical and temporal spread of an epidemic of pneumonic plague following its use as a biological weapon. Univariate and multivariate analyses were performed in order to assess the key parameters for the control of an outbreak in France. If interventions were taken 10 days after an attack, a reference scenario of 1000 index cases in Paris would lead to 2500 deaths. The results of the study indicate that the rapidity of onset of interventions has the largest effect on the final size of the epidemic, followed by wearing masks, treating contacts preventively and quarantine. Limiting inter-regional mixing does little to reduce casualties, although it does confine them to a single region.