bluuebunny/crossref_metadata_2025 huggingface dataset:
NOVEL VACUUM SYSTEM FOR IN-SITU CHARACTERIZATION OF FLUORESCENCE PROPERTIES OF THIN FILMS
Authors: ONOZUKA KOHEI , IWATA NOBUYUKI , YAMAMOTO HIROSHI
Published: December 2002

We constructed a novel vacuum system in which the cathode luminescence properties of as-prepared films can be measured in-situ. It has been observed that the Zn-Ga-O films deposited on 500°C ITO by sputtering emits light with wavelength of about 500 nm from an ultra thin Zn-rich layer formed near film surface. The luminescence induced by irradiation of electrons has also been observed for the first time in the organic bilayered TPD/Alq 3 films prepared in thermal evaporation. Its wavelength blue-shifts by about 120 nm in comparison with the electroluminescence of the same materials. The developed vacuum system is useful to characterize various thin films.
IMPLEMENTATION OF NEURAL NETWORK METHOD TO INVESTIGATE DEFECT CENTERS IN SEMI-INSULATING MATERIALS
Authors: JANKOWSKI S. , WIERZBOWSKI M. , KAMINSKI P. , PAWLOWSKI M.
Published: December 2002

A neural network (NN) method has been proposed as a new algorithm for extraction of defect centers parameters in semi-insulating materials from experimental data obtained by photoinduced transient spectroscopy (PITS). The new algorithm is applied to investigate irradiation-induced defect centers in high resistive silicon. The folds on the PITS spectral surface formed due to the presence of defect levels are best fitted with a two-dimensional approximation function with implementation of the NN learning process. As a result, the Arrhenius plots for defect centers are obtained and the parameters of these centers are determined.
CHARACTERIZATION Of Bi-BASED WHISKERS BY THE METHOD OF Al2O3-SEEDED GLASSY QUENCHED PLATELETS
Authors: KISHIDA S. , UEMOTO H.
Published: December 2002

We prepared the Bi 2 Sr 2 Ca n-1 Cu n O y (Bi-based) whiskers by the method of Al 2 O 3-seeded by the method was about 3 times larger than that by the previous method glassy quenched platelets (ASGQP). The maximum growth rate of the whiskers obtained without any Al 2 O 3 seeding. From the resistance-temperature (R-T) characteristics, we found that the temperature transition widths of the Bi-2212 and the Bi-2223 phases were about 2K and 4K, respectively. In addition, the whiskers showed that the FWHM (full-width-half-maximum) value of the (0010) XRD peak was less than 0.06°. The critical current density of the whiskers was more than 104 A/cm 2 at 60K and 0T. The results indicate that the whiskers grown by the ASGQP method have good crystallinity and high quality.
The Minneapolis-Manchester Quality of Life Instrument: Reliability and Validity of the Adolescent Form
Authors: Bhatia Smita , Jenney Meriel E.M. , Bogue Monica K. , Rockwood Todd H. , Feusner James H. , Friedman Debra L. , Robison Leslie L. , Kane Robert L.
Published: December 2002

PURPOSE: With improvement in survival after childhood cancer, increasing emphasis is being placed on the impact of treatment and its sequelae on the health-related quality of life (HRQL) of survivors. The Minneapolis-Manchester Quality of Life Instrument (MMQL) is a standardized patient self-report instrument designed to assess HRQL in survivors of childhood cancer. The MMQL is being developed for three age groups to address the changing developmental need of different ages: MMQL-Youth (8 to 12 years), MMQL-Adolescent (13 to 20 years), and MMQL-Young Adult (21 to 45 years). This report focuses on the development and testing of the MMQL-Adolescent Form.

PATIENTS AND METHODS: To validate the instrument, the MMQL-Adolescent Form was administered to 397 adolescents (129 healthy individuals, 110 patients with cancer undergoing therapy, and 158 subjects off therapy for cancer). Factor analysis was conducted to refine the instrument. Construct validity was conducted by comparing similar constructs in the MMQL-Adolescent Form and the Child Health Questionnaire (CHQ). Discriminate validity was determined by comparing healthy children with children with cancer either on or off therapy. Stability of the MMQL was tested by readministering the MMQL-Adolescent Form 2 weeks later.

RESULTS: Internal consistency reliability was in the acceptable range for this instrument. The MMQL was able to discriminate between the three study populations. There were high correlations between the MMQL scales and similar CHQ domains. Test-retest reliability of the MMQL-Adolescent Form demonstrated that the instrument was extremely stable in all scales tested.

CONCLUSION: Overall, the data provide evidence for the validity and reliability of the MMQL-Adolescent Form as a comprehensive, multidimensional self-report instrument for measuring HRQL among adolescent survivors of childhood cancer.
Cisplatin and Etoposide Regimen Is Superior to Cyclophosphamide, Epirubicin, and Vincristine Regimen in Small-Cell Lung Cancer: Results From a Randomized Phase III Trial With 5 Years’ Follow-Up
Authors: Sundstrøm Stein , Bremnes Roy M. , Kaasa Stein , Aasebø Ulf , Hatlevoll Reidulv , Dahle Ragnar , Boye Nils , Wang Mari , Vigander Tor , Vilsvik Jan , Skovlund Eva , Hannisdal Einar , Aamdal Steinar
Published: December 2002

PURPOSE: To investigate whether chemotherapy with etoposide and cisplatin (EP) is superior to cyclophosphamide, epirubicin, and vincristine (CEV) in small-cell lung cancer (SCLC).

PATIENTS AND METHODS: A total of 436 eligible patients were randomized to chemotherapy with EP (n = 218) or CEV (n = 218). Patients were stratified according to extent of disease (limited disease [LD], n = 214; extensive disease [ED], n = 222). The EP group received five courses of etoposide 100 mg/m2 intravenously (IV) and cisplatin 75 mg/m2 IV on day 1, followed by oral etoposide 200 mg/m2 daily on days 2 to 4. The CEV group received five courses of epirubicin 50 mg/m2, cyclophosphamide 1,000 mg/m2, and vincristine 2 mg, all IV on day 1. In addition, LD patients received thoracic radiotherapy concurrent with chemotherapy cycle 3, and those achieving complete remission during the treatment period received prophylactic cranial irradiation.

RESULTS: The treatment groups were well balanced with regard to age, sex, and prognostic factors such as weight loss, and performance status. The 2- and 5-year survival rates in the EP arm (14% and 5%, P = .0004) were significantly higher compared with those in the CEV arm (6% and 2%). Among LD patients, median survival time was 14.5 months versus 9.7 months in the EP and CEV arms, respectively (P = .001). The 2- and 5-year survival rates of 25% and 10% in the EP arm compared with 8% and 3% in the CEV arm (P = .0001). For ED patients, there was no significant survival difference between the treatment arms. Quality-of-life assessments revealed no major differences between the randomized groups.

CONCLUSION: EP is superior to CEV in LD-SCLC patients. In ED-SCLC patients, the benefits of EP and CEV chemotherapy seem equivalent, with similar survival time and quality of life.
Supported Ni–Pd Catalysts Active for Methane Decomposition into Hydrogen and Carbon Nanofibers
Authors: Takenaka Sakae , Shigeta Yukio , Otsuka Kiyoshi
Published: December 2002

The supported (Ni–Pd) catalysts showed high activity and long life for methane decomposition to form hydrogen and carbon nanofibers of a unique structure.
Teaching and learning gross anatomy using modern electronic media based on the visible human project
Authors: Jastrow Holger , Vollrath Lutz
Published: December 2002

This article reviews online (Internet) anatomy projects and multimedia productions (books and CD‐ROMs) based on the Visible Human Project (VHP) of the United States National Library of Medicine. The focus of these projects and productions is on the teaching of 3D anatomy using the digitized sections of the visible human male and female. The article also provides information about the VHP, its goals and what it has achieved thus far. Clin. Anat. 16:44–54, 2003. © 2002 Wiley‐Liss, Inc.
Anatomy and physiology of the perionychium
Authors: Zook Elvin G.
Published: December 2002

The nail is a unique structure in the human. Its anatomy and physiology are not well understood by many physicians caring for nail problems. The perionychial anatomy is described along with the physiology pertinent to care of the nail and its surroundings. Clin. Anat. 16:1–8, 2003. © 2002 Wiley‐Liss, Inc.
Survey of Greenland instrumental temperature records: 1873–2001
Authors: Box Jason E.
Published: December 2002

Temporal and spatial variability are analysed in Greenland instrumental temperature records from 24 coastal and three ice sheet locations. Trends over the longest period available, 1873–2001, at Ilulissat/Jakobshavn indicate statistically significant warming in all seasons: 5°C in winter. Trends over the 1901–2000 century in southern Greenland indicate statistically significant spring and summer cooling. General periods of warming occurred from 1885 to 1947 and 1984 to 2001, and cooling occurred from 1955 to 1984. The standard period 1961–90 was marked by 1–2°C statistically significant cooling. In contrast to Northern Hemisphere mean temperatures, the 1990s do not contain the warmest years on record in Greenland. The warmest years in Greenland were 1932, 1947, 1960, and 1941. The coldest years were 1918, 1984, 1993, and 1972, several of which coincide with major volcanic eruptions. Over 1991–2000, statistically significant 2–4°C warming was observed in western Greenland, 1.1°C warming at the ice sheet summit (3200 m), although this is statistically insignificant. Annual temperature trends are dominated by winter variability. Much of the observed variability is shown to be linked with the North Atlantic oscillation (NAO), sea ice extent, and volcanism. The correlation of coastal temperature anomalies with the NAO is statistically significant, in autumn and winter at western and southern sites. Warming from 1873 to 1930 and subsequent cooling persists after the removal of the NAO signal. Temperature trends are often opposite between west and east Greenland. This apparent teleconnection is spurious, however, given insignificant east–west correlation values. Frequency peaks correspond with periods of 3.7, 14.3, 9.1, 5.5–6.0, 11.1, and 7.1 years in both temperature and NAO. Copyright © 2002 Royal Meteorological Society.
The contrasting features of Asian summer monsoon during surplus and deficient rainfall over India
Authors: Raju P. V. S. , Mohanty U. C. , Rao P. L. S. , Bhatla R.
Published: December 2002

An endeavour is made to distinguish the mean summer monsoon features during surplus and deficient monsoon seasons. Based on all‐India summer monsoon rainfall, over 42 years (1958–99), seven surplus and ten deficient monsoon seasons are identified. Making use of daily averaged (00 Z and 12 Z) reanalysis data sets from the National Center for Environmental Prediction–National Center for Atmospheric Research for the corresponding surplus and deficient monsoon seasons, the mean circulation characteristics and large‐scale energetics are examined.

The circulation features denote that the cross equatorial flow, low‐level jet and tropical easterly jet are stronger during a surplus monsoon. Further, strong Tibetan anticyclonic flow characterizes a surplus monsoon. The large‐scale balances of kinetic energy, heat and moisture show a significantly large quantity of diabatic heating, adiabatic generation of kinetic energy, and horizontal convergence of heat and moisture during the surplus monsoon season compared with the deficient state. The regions with statistically significant difference between surplus and deficient monsoon seasons are delineated by a Student's t‐test at the 95% confidence level. The remarkable aspect noticed in this study is that the Arabian Sea branch of the monsoon circulation is more vigorous during a surplus monsoon season, whereas the eastern Bay of Bengal branch is stronger during a deficient monsoon. The various large‐scale budget terms of kinetic energy, heat and moisture are found to be consistent and in agreement with the seasonal monsoon activity over India. Copyright © 2002 Royal Meteorological Society.
Backbone dynamics of the CC‐chemokine eotaxin‐2 and comparison among the eotaxin group chemokines
Authors: Mayer Kristen L. , Stone Martin J.
Published: December 2002

The eotaxin group chemokines (eotaxin, eotaxin‐2, and eotaxin‐3) share only 35–41% sequence identity but are all agonists for the receptor CCR3. Here we present a detailed comparison between the backbone dynamics of these three chemokines. The dynamics of eotaxin‐2 were determined from 15N NMR relaxation data and compared to those obtained previously for eotaxin and eotaxin‐3. For all three chemokines, the majority of residues in the first two β‐strands and the α‐helix show highly restricted motions on the subnanosecond time scale but there is dramatically higher flexibility in the N‐ and C‐terminal regions and also substantial mobility for residues in the N‐loop region and the third β‐strand. The latter two regions form a groove on the chemokine surface that is the likely binding site for the N‐terminal region of the receptor. Taken together, the available data suggest a model in which conformational rearrangements of both the chemokine and the receptor are likely to occur during binding and receptor activation. Proteins 2003;50:184–191. © 2002 Wiley‐Liss, Inc.
Structure of deoxyhemoglobin: Ionizable groups and polyethylene glycol
Authors: Saroff Harry A.
Published: December 2002

X‐ray studies on deoxy‐hemoglobin have been reported on crystals grown under conditions of high (about 2.5 M) and low salt (about 0.1 M). The high‐salt crystals were grown in water, whereas the low‐salt crystals were prepared in polyethylene glycol solutions (m.w. 6000–8000 Da, 10–30% w/v). Oxygen‐binding characteristics of hemoglobin in these two environments differ radically. In salt solutions, hemoglobin binds oxygen with a p50 value of about 5 torr of oxygen and in a cooperative manner characterized with an n value of Hill varying from two to three. In polyethylene glycol solutions, hemoglobin crystals are oxygenated with a p50 value of about 270 torr of oxygen, without exhibiting a cooperative effect. I report on a detailed study of the X‐ray data defining the dimer interface (α1β2) of these two forms of hemoglobin. The study reveals that the main difference between the two structures lies in the number and arrangement of the water molecules and in distances between ionizable side chains in the dimer interface. I propose that these differences lead to significant shifts in the pK values of the ionizable groups in the dimer interface. Proteins 2003;50:329–340. © 2002 Wiley‐Liss, Inc.
Dynamic effects of mutations within two loops of cytochrome c551 from Pseudomonas aeruginosa
Authors: Ceruso Marc Antoine , Grottesi Alessandro , Di Nola Alfredo
Published: December 2002

In this work, we investigated the structural and dynamic consequences of two substitutions, P58A and G36P, located in two different solvent‐exposed loops of cytochrome c551. The results show that both mutations affect regions that are distant from the site of mutation. Here, the two loops appear to be dynamically coupled to each other, because the substitution at one site affects the structure and the dynamics of the other site. However, the substitutions at Gly‐36 and Pro‐58 presented substantial differences, which were related to the mechanical (rigidity and deformability) properties of the site surrounding the mutation. Although the P58A mutant conserved a significant dynamic similarity to the wild‐type protein as the immediate surroundings of position 58 became more rigid, the G36P mutant, which had deformed its flexible surroundings, presented a dynamic behavior that was markedly different from that of the wild‐type protein. These results suggest that perturbation of sterically isolated and flexible regions, such as solvent‐exposed loops, can have strong dynamic consequences on the protein as a whole, raising the possibility that these effects could in turn affect the stability or the function of the protein. Proteins 2003;50:222–229. © 2002 Wiley‐Liss, Inc.
Selective exclusion of treatment arms in multi‐arm randomized clinical trials
Authors: Law Matthew G. , Emery Sean
Published: December 2002

In this paper we discuss a design for multi‐arm randomized clinical trials (RCTs) in which clinicians and their patients can selectively exclude one of the randomized treatment arms. This approach has the advantage that it should expedite protocol development, and allow easier and faster recruitment of patients into the trial. However, to preserve the randomized nature of treatment comparisons, not all recruited patients can be included in all treatment comparisons. This dictates that treatment arms are compared in a pairwise fashion, and that the numbers of patients included in different treatment comparisons may not be equal. The total trial size of a multi‐arm RCT that allowed selective exclusion of arms would be greater than the size of an equivalent standard multi‐arm RCT. However, the duration of time taken to recruit the study would be reduced. The implications for the design, monitoring and analysis of such RCTs are discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Case‐control studies of genotypic relative risks using children of cases as controls
Authors: Austin Harland , Dana Flanders W.
Published: December 2002

The use of a child as a case's control in a case‐control study of genetic factors may be advantageous in some situations. We describe three methods of analysing such data. A method based upon the unconditional likelihood using case/child pairings apparently is the most efficient method. However, a conditional likelihood method using case/child pairs is more robust in that it allows for heterogeneity of the genetic trait among subpopulations as long as matings occur only within the same subpopulation. We argue that the child can be considered a genetic surrogate for the missing spouse and hence such designs are as valid as are those using spouses. Copyright © 2003 John Wiley & Sons, Ltd.
Tests for individual and population bioequivalence based on generalized p‐values
Authors: McNally Richard J. , Iyer Hari , Mathew Thomas
Published: December 2002

The U.S. Food and Drug Administration (FDA) has proposed new regulations that address the ‘prescribability’ and ‘switchability’ of new formulations of already‐approved drugs. These new criteria are known, respectively, as population and individual bioequivalence. Two methods have been proposed in the bioequivalence literature for assessing population and individual bioequivalence that calculate an upper 95 per cent confidence bound for the bioequivalence criterion in question, and then test bio‐equivalence by comparing this bound to the limit established by the FDA. In this paper we propose applying the generalized test function (GTF) methodology of Tsui and Weerahandi (Journal of the American Statistical Association 1989; 602–607) to this problem to produce tests based on a generalized p‐value (GPV). This methodology allows us to construct hypothesis tests in the presence of nuisance parameters. Using simulation we show that these tests perform well in comparison to the confidence interval methods and have superior power for assessing population bioequivalence. Copyright © 2003 John Wiley & Sons, Ltd.
P³: a code and design conventions preprocessor for Java
Authors: Depradine Colin , Chaudhuri Pranay
Published: December 2002

One of the techniques employed by programmers during the development process is the use of code and design conventions. These are rules‐of‐thumb or best practices that improve the maintainability of software applications. In general, these conventions are maintained manually by the programmer since automated support is usually restricted to the automatic generation of code. However, the late discovery of convention errors can result in significant costs due to the effort required to correct them. In order to facilitate the early detection of these errors, the Practical Preprocessor for Programming Conventions system, P³ (pronounced P3),is proposed. This tool acts as a preprocessor to the Java compiler by providing facilities for the maintenance of specific object‐oriented code conventions and design principles during the creation of Java programs. This paper presents the design and implementation of the P³ system and also the practical experience of using this facility in a University programming environment. Copyright © 2002 John Wiley & Sons, Ltd.
Role of caspases in murine limb bud cell death induced by 4‐hydroperoxycyclophosphamide, an activated analog of cyclophosphamide
Authors: Huang Chunwei , Hales Barbara F.
Published: December 2002

Background

Caspases play a pivotal role in the regulation and execution of apoptosis, an essential process during limb development. Caspase 8 activation is usually downstream of the Fas/FasL death receptors, whereas caspase 9 mediates the mitochondrial signaling pathway of apoptosis. Caspase 3 is an effector caspase. Previous studies have shown that the exposure of embryonic murine limbs in vitro to 4‐hydroperoxycyclophosphamide (4‐OOHCPA), an activated analog of the anticancer alkylating agent, cyclophosphamide, induced limb malformations and apoptosis. The goal of this study was to determine the role of caspases in mediating apoptosis in this model system.

Methods

Limb buds from gestational day 12 CD‐1 mice were excised and cultured in roller bottles in a chemically defined medium for up to 6 days in the absence or presence of 4‐OOHCPA. Apoptosis was indicated by internucleosomal DNA fragmentation, as detected by TUNEL staining. The profile of caspase activation was characterized by Western blot analysis and immunohistochemistry of control and treated limbs. To determine the consequences to limb morphology of inhibiting caspase activation, DEVD‐CHO, a caspase‐3 inhibitor, was added to the cultures.

Results

Limbs cultured in the presence of 4‐OOHCPA were growth retarded and malformed; apoptosis was increased in the apical ectodermal ridge and interdigital areas. Western blot analysis showed that 4‐OOHCPA exposure did not activate procaspases 8 or 9 in limbs. In contrast, procaspase‐3 cleavage was increased in a concentration and time‐dependent manner after exposure of limbs to 4‐OOHCPA. Immunoreactive activated caspase‐3 was localized in the interdigital areas and the apical ectodermal ridge region in control limbs; staining in these areas and in the interdigital areas was increased dramatically in limbs exposed to 4‐OOHCPA. Inhibition of caspase 3 activation with DEVD‐CHO partially protected limbs from insult with 4‐OOHCPA.

Conclusion

Caspase‐dependent and caspase‐independent pathways of cell death are both important is mediating the abnormal limb development triggered by insult with 4‐OOHCPA. Teratology 66:288–299, 2002. © 2002 Wiley‐Liss, Inc.
Gaze and task performance in shared virtual environments
Authors: Bailenson Jeremy N. , Beall Andrew C. , Blascovich Jim
Published: December 2002

Non‐verbal behaviour, particularly gaze direction, plays a crucial function in regulating conversations and providing critical social information. In the current set of studies, we represented interactants in a shared immersive virtual environment. Interactants sat in physically remote rooms, entered a common virtual room and played games of 20 questions. The interactants were represented by one of three types of avatars: (1) human forms with head movements rendered in real time; (2) human forms without head movements rendered; or (3) human voice only (i.e., a conference call). The data demonstrated that interactants in the rendered head movement condition rated a higher level of co‐presence, liked each other more, looked at each other's heads more, and spoke for a lower percentage of time during the game, compared to the other two conditions. We discuss implications for the design of shared virtual environments, the study of non‐verbal behaviour and the goal of facilitating efficient task performance. Copyright © 2002 John Wiley & Sons, Ltd.
Multiple animated characters motion fusion
Authors: Zhongxiang Luo , Yueting Zhuang , Feng Liu , Yunhe Pan
Published: December 2002

One of the major problems of the motion capture‐based computer animation technique is the relatively high cost of equipment and low reuse rate of data. To overcome this problem, many motion‐editing methods have been developed. However, most of them can only handle one character whose motions are preset, and hence cannot interact with its environment automatically. In this paper, we construct a new architecture of multiple animated character motion fusion, which not only enables the characters to perceive and respond to the virtual environment, but also allows them to interact with each other. We will also discuss in detail the key issues, such as motion planning, coordination of multiple animated characters and generation of vivid continuous motions. Our experimental results will further testify to the effectiveness of the new methodology. Copyright © 2002 John Wiley & Sons, Ltd.
Subtleties of facial expressions in embodied agents
Authors: Pelachaud Catherine , Poggi Isabella
Published: December 2002

Our goal is to develop a believable embodied agent able to dialogue with a user. In particular, we aim at making an agent that can also combine facial expressions in a complex and subtle way, just like a human agent does. We first review a taxonomy of communicative functions that our agent is able to express non‐verbally; but we point out that, due to the complexity of communication, in some cases different information can be provided at once by different parts and actions of an agent's face. In this paper we are interested in assessing and treating what happens, at the meaning and signal levels of behaviour, when different communicative functions have to be displayed at the same time and necessarily have to make use of the same expressive resources. In some of these cases the complexity of the agent's communication can give rise to conflicts between the parts or movements of the face. In this paper, we propose a way to manage the possible conflicts between different modalities of communication through the tool of belief networks, and we show how this tool allows us to combine facial expressions of different communicative functions and to display complex and subtle expressions. Copyright © 2002 John Wiley & Sons, Ltd.
Reanalysis of Lunar Prospector neutron spectrometer observations over the lunar poles
Authors: Hodges R. Richard
Published: December 2002

Components of the neutron energy spectrum measured by instruments on the Lunar Prospector (LP) spacecraft have been optimistically interpreted as indicating massive deposits of water ice or other hydrogenic minerals in the polar regions of the Moon. An independent reanalysis of the theory of leakage neutrons shows that in addition to the observed depressions of the epithermal neutron flux the signature of polar hydrogen in the lunar regolith would have included a distinctive increase in the thermal neutron flux that apparently was not detected. Other simulations of LP neutron data show that the neutron signature of a mineralogical anomaly as simple as a localized excess of silicate would be about the same as that of hydrogen. A deficit of CaO would produce the LP result, that is, a decrease of epithermal neutrons with no noticeable change in the thermal neutron flux. Other more complicated mineral variants could yield similar effects. What is clear is that the existence of polar water ice or hydride deposits has not been proven by analyses of Lunar Prospector data.
Stable carbon isotopic evidence for methane oxidation in plumes above Hydrate Ridge, Cascadia Oregon Margin
Authors: Grant Nicholas J. , Whiticar Michael J.
Published: December 2002

The transport and consumption of methane in the water column in the vicinity of the cold seeps of Hydrate Ridge on the Cascadia Oregon Margin were characterized using measurements of the stable carbon isotope composition of methane. The δ13C‐CH4 values measured in the water column ranged from approximately −65 to −16‰, PDB. The combination of measured methane concentration data and the stable carbon isotope values from the same depths support the hypothesis of biogenically produced methane which enters the water column from dissolving bubbles released from cold seepages, likely as a consequence of destabilized methane hydrate (δ13C‐CH4 = −65‰, PDB). Kinetic fractionation factors, α, associated with aerobic bacterial methane oxidation in the water column were calculated using a Rayleigh distillation equation applied to a subset of the data. Fractionation factors ranged from 1.002 to 1.013 (mean = 1.008) and were in the lower end of the range of those reported in the literature, a result likely due to the influence of temperature and mixing in plume waters. The fraction of methane remaining after oxidation calculated using the same Rayleigh model approach suggests that the aerobic oxidation of methane in the water column over Hydrate Ridge is nearly quantitative.
A cohesive total ozone data set from the SBUV(/2) satellite system
Authors: Miller A. J. , Nagatani R. M. , Flynn L. E. , Kondragunta S. , Beach E. , Stolarski R. , McPeters R. D. , Bhartia P. K. , DeLand M. T. , Jackman C. H. , Wuebbles D. J. , Patten K. O. , Cebula R. P.
Published: December 2002

The long‐term data collection of total ozone estimates from the Solar Backscatter Ultraviolet Ozone Sensors (SBUV and SBUV/2) began with the launch of SBUV on NASA's Nimbus‐7 spacecraft in 1978. Following this successful demonstration, the National Oceanic and Atmospheric Administration (NOAA) adopted the slightly modified SBUV/2 instruments for placement on the afternoon Polar‐Orbiting Operational Environmental Satellites (POES). The SBUV/2 instruments have flown on NOAA‐9, ‐11, ‐14, and ‐16 in the POES series, with NOAA‐16 launched in late 2000. Three more instruments are scheduled for launches in the next 6 years. While the absolute calibrations of individual instruments are good, they give total ozone accuracies of approximately 2%. However, without further adjustment, such interinstrument differences pose significant problems for atmospheric ozone trend analysis. In this paper we use the differences between total ozone estimates from the instruments during periods with overlapping coverage to account for these possible calibration biases. We use the NOAA‐9 SBUV/2 record as the reference standard because of the length of its record and the amount of overlap with other instruments' records. By applying adjustments to the other data sets based on these differences, a complete, unified data set is created for use in analysis of long‐term changes. The monthly‐averaged total ozone time series for 50°S to 50°N and the hemispheric subsets are compared to the results from two 2‐D chemistry models as a demonstration of the usefulness of the unified data sets.
Comparison of GPS slant wet delay measurements with model simulations during the passage of a squall line
Authors: Ha So‐Young , Kuo Ying‐Hwa , Guo Yong‐Run , Rocken Chris , Van Hove Teresa
Published: December 2002

Slant wet delay (SWD) measurements from a ground‐based GPS observation network provide accurate, high‐resolution moisture information for mesoscale analysis. In this study, we compared SWD simulated from a 9‐km MM5 model in a prefrontal squall line event against actual GPS SWD observations by NOAA's GPS network. We found that the model simulation did not capture abrupt moisture changes and small‐scale variations observed in the nonisotropic component of slant wet delays associated with the squall line. This result suggests that SWD measurements can be very useful in improving model moisture analysis.
Diurnal variability of aerosol optical depth observed at AERONET (Aerosol Robotic Network) sites
Authors: Smirnov A. , Holben B. N. , Eck T. F. , Slutsker I. , Chatenet B. , Pinker R. T.
Published: December 2002

Diurnal variability of aerosol optical depth is important for various applications, including satellite aerosol data validation, radiative forcing computations, studies of aerosol interaction with humidity and clouds, and also public health. Aerosol optical depth measurements acquired through the ground‐based Aerosol Robotic Network are analyzed. Analysis of the diurnal cycle over major urban/industrial areas within the network showed a prevailing pattern of the optical depth increase by 10–40% during the day at most sites. Diurnal variability range is <10% over various sites where dust aerosol is a major contributor to optical depth. Sites in southern Africa influenced by distant sources of biomass burning aerosol show no diurnal cycle, while the presence of local sources causes a diurnal trend with a maximum aerosol loading observed in the afternoon hours. Over oceans, because of the very low optical depth, even 20% departure from the daily average is practically within the measurement uncertainty.
TIME DEPENDENCE OF BRANS–DICKE PARAMETER ω FOR AN EXPANDING UNIVERSE
Authors: SAHOO B. K. , SINGH L. P.
Published: December 2002

We have studied the time dependence of ω for an expanding universe in the generalised B-D theory and have obtained its explicit dependence on the nature of matter contained in the universe in different era. Lastly, we discuss how the observed accelerated expansion of the present universe can be accommodated in the formalism.
RENORMALIZATION OF THE NEUTRINO MASS MATRIX
Authors: KUO T. K.
Published: December 2002

The renormalization group equations for the general 2 × 2, complex, neutrino mass matrix are shown to have exact, analytic solutions. Simple formulas are given for the physical mixing angle, mass ratio and intrinsic CP phase. We also establish a (complex) renormalization invariant relating these parameters. It is found that the mixing angle exhibits the resonance behavior. Also, the infrared fixed point corresponds to vanishing mixing angle and infinite mass hierarchy.
LOW ENERGY GAUGE UNIFICATION THEORY
Authors: LI TIANJUN , LIAO WEI
Published: December 2002

Because of the problems arising from the fermion unification in the traditional grand unified theory and the mass hierarchy between the four-dimensional Planck scale and weak scale, we suggest the low energy gauge unification theory with low high-dimensional Planck scale. We discuss the nonsupersymmetric SU(5) model on M4 × S1/Z2 × S1/Z2 and the supersymmetric SU(5) model on M4 × S1/(Z2 × Z2′) × S1/(Z2 × Z2′). The SU(5) gauge symmetry is broken by the orbifold projection for the zero modes, and the gauge unification is accelerated due to the SU(5) asymmetric light KK states. In our models, we forbid the proton decay, still keep the charge quantization, and automatically solve the fermion mass problem. We also comment on the anomaly cancellation and other possible scenarios for low energy gauge unification.
STRAINED SILICON GERMANIUM HETEROSTRUCTURES FOR DEVICE APPLICATIONS
Authors: KASPER E.
Published: December 2002

Silicon Germanium is lattice mismatched to Silicon by up to 4.2% depending on the Ge content. Up to a critical thickness elastic strain accommodates the mismatch. The band ordering of SiGe/Si interfaces is strongly influenced by the strain shifting the band ordering from flat conduction band to a type II ordering when proper strain adjustment is performed. As device examples the heterobipolartransistor, hetero field effect transistor and room temperature Esaki tunneling are treated. As key questions for further material development are identified the growth and processing of ultrametastable layers and the strain adjustment by thin virtual substrates.
H DISTRIBUTION AND STRAIN EVOLUTION IN SiGe/Si HETEROSTRUCTURE IMPLANTED BY H DIMERS
Authors: AN ZHENGHUA , MEN CHUANLING , LIU WEILI , ZHANG MIAO , WU YANJUN , XIE XINYUN , CHU PAUL K. , LIN CHENGLU
Published: December 2002

A 75nm Si 0.84 Ge 0.16 film was grown at 500°C with Si 2 H 6 and GeH 4 precursors. After depositing an oxide layer on the top, the samples were implanted with [Formula: see text] ions at an energy of 38keV, and a dose of 3.5 × 1016 cm -2. These implanted samples were annealed in the temperature range from 400°C to 700°C. H redistribution occurs during this process. Meanwhile, great tensile strain was introduced by implantation into the SiGe/Si heterostructure layers and following annealing relieved the strain. High temperature annealing almost fully relaxed the SiGe layer.
INTENSE ROOM-TEMPERATURE PHOTOLUMINESCENCE FROM NANOCRYSTALLINE Ge/SiO2 MULTILAYER STRUCTURES
Authors: CHENG WENJUAN , JIA HAIJUN , FANG YUJING , HE DEYAN
Published: December 2002

Hydrogenated amorphous Ge / amorphous Si multilayers with different thickness of sublayers were prepared on Si wafer by plasma-enhanced chemical vapor deposition and then oxidized at 800°C for various oxidation durations. Intense photoluminescence with multiple peaks was observed for the samples at room temperature. One peak is centered at the wavelength around 755 nm, which is almost unchanged from sample to sample and could be attributed to the luminescence from the defect states located at the interfaces between the formed nano-crystalline Ge and SiO 2. Another peak around 720 nm shows blue shift with increasing the oxidation duration, which may be deduced from the quantum confinement effect of nc-Ge. The luminescence from the samples with the same thickness of SiO 2 sublayers and different thickness of nc-Ge sublayers supported the suggested luminescence origin.
HIGH GROWTH-RATE DEPOSITION OF μc-Si:H THIN FILM AT LOW TEMPERATURE WITH VHF-PECVD
Authors: YANG HUIDONG , WU CHUNYA , MAI YAOHUA , LI HONGBO , LI YAN , ZHAO YING , XUE JUNMING , CHEN YOUSU , REN HUIZHI , GENG XINHUA , XIONG SHAOZHEN
Published: December 2002

High growth rate deposition of μ c - Si:H film with VHF-PECVD at low temperature has been reported. Investigations showed that growth rates enhanced with higher excitation frequency and working pressure, but increased at first then decreased with the increase of plasma power. Optical emission spectroscopy (OES) was introduced to monitor VHF plasma. The relationship between the growth rates and the OES results has been discussed. Raman spectra were also used to study the a - Si:H /μ c - Si:H phase transition. Finally a high growth rate of 2.0nm/s has been obtained through the initially optimized condition.
SIMULATION AND FABRICATION OF THERMO-OPTIC VARIABLE OPTICAL ATTENUATORS BASED ON MULTIMODE INTERFERENCE COUPLER
Authors: YANG LIN , LIU YULIANG , LI FANG , CHENG YI , QIU HAIJUN , WANG QIMING
Published: December 2002

A type of thermo-optic variable optical attenuator based on multimode interference coupler is proposed. The optical field propagation properties of the devices are simulated using finite difference beam propagation method. The propagation loss of the fabricated device is 2-4.2 dB at the wavelength range 1510-1610 nm. The total power consumption is 370 mW and the maximum attenuation is more than 25 dB, which almost can meet the requirements of optical fiber communication systems.
ABRUPT BORON PROFILES BY SILICON-MBE
Authors: OEHME M. , KASPER E.
Published: December 2002

Surface segregation and diffusion are the dominant mechanisms for profile smearing. However in the low temperature regime below 600°C diffusion is negligible. We investigated the dopant profile during silicon molecular beam epitaxy (MBE) in silicon (100). A method for measurement of the adlayer density of segregating dopant atoms is suggested. We utilize the results of this experiment to generate very sharp boron profiles. For the doping we use the pre-build up method with constant boron flux.
SYSTHESIS AND OPTICAL PROPERTIES OF RARE EARTHS DOPED NANO-SEMICONDUCTORS AND THEIR APPLICATIONS
Authors: ZHAO XINWEI , HARAKO SUSUMU , NOGUCHI SHINRI , KOMURO SHUJI
Published: December 2002

Er and Yb have been doped into nanocrystalline Si and ZnO thin films. Sharp and intense photoluminescence (PL) lines related to intra-4f transitions in the rare earth ions were observed. The optical transition dynamics of the rare earth ions were investigated by time-resolved PL measurements. It was demonstrated that a nano-meter sizing of Si widened the energy bandgap and led to an increase of doping densities of the rare earths. It was also shown that the Er-related PL gave rise to different features under direct and indirect excitations indicating a strong interaction of electron-hole pairs in the host with 4f electrons in the rare earth ions. A co-doping effect of Yb and Er into nanocrystalline Si was presented also. Our results suggested a rare earth-rare earth coupling between the Yb 3+ ions and the Er 3+ ions, which transferred the energy from Yb to Er and enhanced the 1.54 μm PL of Er.
ELECTROPHORETIC ASSEMBLY OF POROUS SILICON
Authors: LI HUAIXIANG , XUE CHENGSHAN , ZHANG HUA , GUO CHENGHUA , LI CHUANBO , CHEN LUSHENG , DIAO ZHAOYU
Published: December 2002

Electrophoretic assembly of porous silicon (PS) has been studied in the present paper. A toluene/porous silicon suspension was prepared by the sonication of anodically etched porous silicon wafers and showed a PL property similar to the as-prepared PS, giving 620nm orange-red photoluminescence emissions. A broad optical absorption band about 286nm arising from scattering and absorption of the light by the PS particles has been observed. The PS particles suspended in toluene drifted towards the positive electrode and have been assembled on the surface of P+Si or indium-tin oxide (ITO) electrodes under a electric field of 100~600V/cm. The assembled PS films showed a quite stable PL property after ageing for 280 days even though there were some oxides revealed by XPS analysis.
COMPARISON OF DONOR AND ACCEPTOR LEVELS IN UNDOPED, HIGH QUALITY β-FeSi2 FILMS GROWN BY MBE AND MULTI-LAYER METHOD
Authors: TAKAKURA K. , SEKI N. , SUEMASU T. , HASEGAWA F.
Published: December 2002

The carrier density of highly [100]-oriented β- FeSi 2 films grown by molecular beam epitaxy (MBE) was smaller than that by the multilayer method. For the MBE grown, undoped n- and p-type β- FeSi 2 films, only one donor (E D1 = 0.21 eV) and one acceptor (E A2 = 0.11 eV) levels were obtained from the temperature dependence of the carrier density, in contrast with the fact that two kinds of donor (E D1 = 0.21 eV and E D2 = 0.08 eV) and acceptor (E A1 = 0.19 eV and E A2 = 0.11 eV) levels were obtained for layers grown by multi-layer method. These results suggest that the decrease of the carrier density in the MBE-grown films is due to disappearance of the E D2 or E A1 level.
ICP ETCHING AND STRUCTURE STUDY OF PECVD SiC FILMS
Authors: SHI J. , CHOI W. K. , CHOR E. F.
Published: December 2002

Results of Induction Coupled Plasma (ICP) etching of as-prepared and annealed PECVD hydrogenated amorphous silicon carbide ( a-Si 1-x C x : H ) films using CF 4/ O 2 chemistry are presented. The etch rate of the annealed films decreased with an increase in annealing temperature. Infrared spectra for the annealed films showed a significant decrease in the Si-H and C-H bonds, and a pronounced increase in the Si-C bonds. The XRD results showed several poly-crystalline Si-C structure in films annealed at 800°C. ESR spectra show the density of the dangling bonds increased as a function of annealing temperature. The drop in etch rate of the annealed films is due to the reduction in porous structures resulted from dehydrogenation and increased crystallinity of the film.
NICKEL SILICIDATION ON POLYCRYSTALLINE SILICON GERMANIUM FILMS
Authors: CHOI W. K. , PEY K. L. , ZHAO H. B. , OSIPOWICZ T. , SHEN Z. X.
Published: December 2002

The interfacial reactions of Ni with polycrystalline Si 0.8 Ge 0.2 films at a temperature range of 300-900°C by rapid thermal annealing for 60s are studied. The sheet resistances of the silicide films were relatively low at ~10 ohm/sq for samples annealed below 600°C. X-Ray diffraction results suggested the existence of low resistivity phase Ni(Si 1-x Ge x ) in the film. The significant increase in sheet resistance for films annealed at 700-900°C is probably due to the reduction in the density of Ni(Si 1-x Ge x ) as a result of fast Ni diffusion at high annealing temperatures. Fast grain boundary diffusion of Ni was suggested to cause the lowering of formation temperature of Ni(Si 1-x Ge x ) on polycrystalline Si 1-x Ge x films. Rutherford backscattering results showed that for films annealed at a temperature range of 300-600°C, Ni has reacted with the polycrystalline films. However, at an annealing temperature higher than 700°C, Ni diffused through the whole film.
SURFACE AND STRUCTURAL CHARACTERIZATION OF CuInS2 THIN FILMS DEPOSITED BY ONE-STAGE RF REACTIVE SPUTTERING
Authors: HE YUNBIN , ÖSTERREICHER I. , KRÄMER T. , POLITY A. , KRIEGSEIS W. , MEYER B. K. , HARDT M.
Published: December 2002

CuInS 2 films were deposited on float glass substrates by a one-stage reactive RF sputter process using a Cu-In alloy target and H 2 S gas. The sputtered films generally have a (112) preferential orientation. X-ray reflectometry was used to measure the thickness, surface density as well as surface roughness of the sputtered films. The surface morphology of the films was studied by scanning electron microscopy. Energy-dispersive X-ray analysis was performed to determine the composition of the films. XPS revealed that the film surfaces remain In-rich with respect to the bulk.
PHOTOREFLECTANCE STUDY OF AIN THIN FILMS GROWN BY REACTIVE GAS-TIMING RF MAGNETRON SPUTTERING
Authors: KIETIPAISALSOPHON N. , BUNJONGPRU W. , NUKEAW J.
Published: December 2002

Band-gap energy of AIN thin films was investigated by room-temperature photoreflectance (PR) spectroscopy. Using rf magnetron sputtering, the reactive gas-timing technique was successfully applied to grow cubic-AIN thin films. The define XRD patterns of all deposited films show orientation of cubic structure in (111) and (200) planes. The PR spectra clearly exhibit a band-gap energy of cubic-AIN depending on the flow rate of N 2 gas. The band-gap transition energies were determined by fitting the PR spectra to theoretical line-shape expression. The band-gap transition energies decreased with increasing flow rate of N 2.
PREPARATION AND STRUCTURE CHARACTERIZATION OF BiFeO3-SrBi2Nb2O9 THIN FILMS ON SILICON BY SOL-GEL PROCESSING
Authors: GU HAOSHUANG , CAO WANQIANG , XUE JUNMIN , WANG JOHN
Published: December 2002

A new system 0.1 BiFeO 3-0.9 SrBi 2 Nb 2 O 9 thin films have been successfully prepared by an ethanolamine-modified sol-gel technique. The precursor solution was synthesized from compounds, Bi(NO 3)3· 5H 2 O , Sr(NO 3)2, Fe(NO 3)3· 9H 2 O and Nb(OC 2 H 5)5 in solution ethylene glycol monomethyl ether. The thin films were deposited on Si single crystal by spinning coating, and heat-treated at temperatures ranging from 400°C to 700°C. Crystallization of thin films occurred at about 500 ~ 600°C and the films exhibit a pure phase of layered perovskite ferroelectric structure. The grain of films is well distributed and the average grain size of the film is about 100nm.
STRUCTURAL AND FERROELECTRIC CHARACTERIZATION OF PZT THIN FILMS
Authors: YANG YING , CHEN ZHIMING , ZHAO GAOYANG , ZHANG WEIHUA
Published: December 2002

Pb(Zr x Ti 1-x ) O 3 (PZT) films were prepared on the ITO coated glass plates in sol-gel dip-coating process and post-annealing at different temperatures. The structural properties of the films were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It is shown that the PZT ferroelectric thin films with (110) preferential orientation and well-crystallized perovskite structure can be obtained after annealing at 680°C for 30 minutes. The P-E hysteresis loops were measured by the Sawyer-Tower test system with a compensation resistor at room temperature. Values of the remanent polarization (Pr) and the coercive electric field (Ec) are 19.36• C/cm 2 and 95 kV/cm, respectively, for the prepared PZT thin films. The relative dielectric constant εr and the dissipation factor tg• of the PZT thin films are equal to 639 and 0.23, respectively, which were measured in a LCR meter.