Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Raman Spectroscopic Observation of a Conformational Change at the Heme-Protein Linkage in Myoglobin at High Pressure (1995)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 117 (1995), S. 10149-10150 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00145a041
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Adult Crohn disease: can ileoscopy replace small bowel radiology? (1998)
    Springer
    Abdominal imaging 23 (1998), S. 117-121 
    Details
    ISSN: 1432-0509
    Keywords: Key words: Small intestine, radiography—Intestine, diagnosis—Crohn disease—Endoscopy.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Background: This study aimed to document the radiological features and distribution of small bowel Crohn disease (CD) in adults by using a barium follow-through (BaFT) technique and to determine whether disease would be missed or its distribution underestimated if only colonoscopy with ileoscopy were performed. Methods: The BaFT examinations of 121 adults with proven CD were reviewed retrospectively with respect to the stage and distribution of disease. Colonoscopy with attempted ileoscopy was performed in 37 of these subjects, and the results were compared with radiological findings. Results: A normal villous pattern was visualized in 89 studies (74%). BaFT showed small bowel CD in 71 (59%) of 121 patients studied. The terminal ileum (TI) was the most common site of disease, affecting 62 (87%) of patients with small bowel CD. Forty-six patients (65%) had more proximal small bowel disease, including nine (13%) with a normal TI. BaFT showed early mucosal changes of CD in 52 subjects (73%), which was the sole manifestation in 15 (21%). Ileoscopy was possible in the majority of patients colonoscoped but was not achieved in 14 (38%), nine of whom had CD on BaFT. Of the 23 patients in whom ileoscopy was performed, findings agreed with BaFT assessment of the TI in 22. Conclusion: BaFT adequately demonstrates the stage and extent of small bowel CD. The majority of patients with small bowel CD have disease proximal to the TI, which cannot be diagnosed by ileoscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002619900301
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Genetic analysis of the resting electroencephalographic power spectrum in human twins (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Psychophysiology 33 (1996), S. 0 
    Details
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: Most twin studies have provided evidence for genetic effects on the electroencephalogram (EEG). In two twin studies, monozygotic (MZ) cotwin covariance for EEG power was greater than expected for additive gene actions, as compared with dizygotic (DZ) cotwin covariance. These findings were attributed to complex gene interactions, termed emergenesis. In the present study of 53 MZ and 38 DZ twin pairs departures from the additive genetic model were tested on resting EEG power. Total spectral power and the quotient of (beta band power)/(total power) both fit gene interaction models significantly better than did additive genetic models. These findings support the previous findings of MZ covariance for EEG power as much greater than DZ covariance; these findings can be explained entirely by the additive effects of genes. This pattern of twin covariances could be due to gene interactions but also to greater MZ than DZ environmental covariance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1469-8986.1996.tb02435.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Cation distribution in NiZn-ferrite films determined using x-ray absorption fine structure : The 40th annual conference on magnetism and magnetic materials (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 4561-4563 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have applied extended x-ray absorption fine structure (EXAFS) spectroscopy to study the cation distribution in a series of spin-sprayed NiZn-ferrite films, Ni0.15ZnyFe2.85−yO4 (y=0.16, 0.23, 0.40, 0.60). The Ni, Zn, and Fe EXAFS were collected from each sample and analyzed to Fourier transforms. Samples of Ni-ferrite, Zn-ferrite, and magnetite were similarly studied as empirical standards. These standards, together with EXAFS data generated from the theoretical EXAFS FEFF codes, allowed the correlation of features in the Fourier transforms with specific lattice sites in the spinel unit cell. We find that the Ni ions reside mostly on the octahedral (B) sites whereas the Zn ions are predominantly on the tetrahedral (A) sites. The Fe ions reside on both A and B sites in a ratio determined by the ratio of Zn/Fe. The addition of Zn displaces a larger fraction of Fe cations onto the B sites serving to increase the net magnetization. The fraction of A site Ni ions is measured to increase peaking at ≈25% for y=0.6. At higher Zn concentrations (y≥0.5) the lattice experiences local distortions around the Zn sites causing a decrease in the superexchange resulting in a decrease in the net magnetization. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.361725
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    TWO-DIMENSIONAL DOPANT PROFILING BY SCANNING CAPACITANCE MICROSCOPY (1999)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Materials Research 29 (1999), S. 471-504 
    Details
    ISSN: 0084-6600
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The scanning capacitance microscope (SCM) provides a direct method for mapping the dopant distribution in a semiconductor device on a 10 nm scale. This capability is critical for the development, optimization, and understanding of future ULSI processes and devices. The basic elements of the SCM and its application to nanometer scale metal oxide semiconductor (MOS) capacitor measurements are described. Experimental SCM methods are reviewed. Basic measurements show that nanometer scale capacitance-voltage relations are understood. High-quality probe tips and surfaces are critical for obtaining accurate measurements of two-dimensional dopant profiles. Quantitative modeling of SCM measurement is described for converting raw SCM data to dopant density. An inverse modeling method is presented. Direct comparison between secondary ion mass spectroscopy (SIMS) and SCM-measured dopant profiles are made. Quantitative junction measurements and models are discussed and images of small transistors are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1146/annurev.matsci.29.1.471
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Two-step dopant diffusion study performed in two dimensions by scanning capacitance microscopy and TSUPREM IV (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 1305-1309 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the results of a two-step two-dimensional (2D) diffusion study by scanning capacitance microscopy (SCM) and 2D SUPREM IV process simulation. A quantitative 2D dopant profile of a gate-like structure is measured with the SCM on a cross-sectioned polished silicon wafer. The gate-like structures consist of heavily implanted n+ regions separated by a lighter doped n-type region underneath 0.56 μm gates. The SCM is operated in the constant-change-in-capacitance mode. The 2D SCM data are converted to dopant density through a physical model of the SCM/silicon interaction. This profile has been directly compared with 2D SUPREM IV process simulation and used to calibrate the simulation parameters. The sample is then further subjected to an additional diffusion in a furnace for 80 min at 1000 °C. The SCM measurement is repeated on the diffused sample. This final 2D dopant profile is compared with a SUPREM IV process simulation tuned to fit the earlier profile with no change in the parameters except the temperature and time for the additional diffusion. Our results indicate that there is still a significant disagreement between the two profiles in the lateral direction. SUPREM IV simulation considerably underestimates the diffusion under the gate region. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.368245
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Magnetization and coercive force of pulsed laser deposited MnZn-ferrite single crystal films (abstract) : The 41st annual conference on magnetism and magnetic materials (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 4800-4800 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The authors have examined magnetic and structural properties for a series of pulsed laser ablated single crystal MnZn-ferrite films. The films were epitaxially grown on (001) MgO with substrate temperatures ranging from 300 to 900 °C in oxygen pressures of 15, 30, 60, and 90 mTorr. Contrary to conventional belief, the stoichiometry of pulsed laser deposited ferrite films does not necessarily reflect that of the target. We found the film compositions vary with substrate temperature as well as with the oxygen pressure during deposition. A comparison of the magnetic, structural, and chemical properties shows (1) the magnetization scales with Fe2+ ion concentration for all oxygen pressures and (2) the coercive force is sensitive to the microstructure. Magnetization values for films deposited at 60 and 90 mTorr were found to exceed those of bulk MnZn ferrites; for some deposition temperatures the magnetization exceeded that of bulk by a factor of 2.5. This increase in magnetization is explained in terms of the excess number of Fe2+ ions on the octahedral site of the MnZn-ferrite spinel structure. Results of extended x-ray absorption fine structure measurements of the films will also be discussed.© 1997 American Institute of Physics. This work was supported by NSF Contract No. DMR9400439.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.364741
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Charge centroid and origin of generated and intrinsic bulk defects at 293 and 100 K in insulated gate field effect transistors (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 1566-1574 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Intrinsic and generated bulk defects in the gate insulator of silicon insulated gate field effect transistors were examined using a continuous forward-bias pulsed injection technique to inject up to 1017 e/cm2 at 293 and 100 K, for insulator thicknesses ranging between 5.4 and 50.5 nm. The amount of trapping observed at 100 K was about 30 times greater than that at 293 K. The additional trapping at the reduced temperature was determined to come from two sources. One is trapping by existing shallow bulk defects, and the other is an increase in the density of generated bulk defects. The defect generation process is thought to be related to the neutral hole trap becoming unstable during injection, acting as an electron trap. This instability appears to be enhanced as the temperature is reduced to 100 K by a "freeze out'' effect, or by higher energy carriers that result from a reduction in the thermal scattering. The defect generation rate follows a power law, much like a chemical rate equation, i.e., the rate of defect generation is dependent on the injection current density, much like a chemical reaction is dependent on pressure of the reactive species. The charge centroid of the generated defects, measured from the substrate/oxide interface, was determined at both temperatures and the centroid of the shallow electron traps was determined at 100 K. These were found to be in the range of 6–8 nm at 100 K and 10–16 nm at 293 K. Also, a defect free, or tunneling, region of 2–4 nm extent was determined to exist at each interface. This implies that when the oxide thickness decreases to about 4–8 nm, no threshold voltage shift should result from carrier injection at room, or low temperature, and in fact this behavior was observed in these devices (at least up to 1017 e/cm2 injected). It was found that the shallow traps can be rapidly depopulated by subjecting the devices to ordinary white light during normal device use, pointing to a possible method to improve device reliability at 100 K. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.364087
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The role of photosynthesis/light relationships in determining lower depth limits of Characeae in South Island, New Zealand lakes (1996)
    Oxford BSL : Blackwell Science Ltd
    Freshwater biology 35 (1996), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: 1. The maximum depth of colonization of aquatic macrophytes (Zc) was investigated in eighteen South Island, New Zealand lakes. The downward attenuation coefficient for photosynthetically active radiation (Kd(PAR)) was calculated and the spectral characteristics of the lakes determined with a spectroradiometer.2. Characean algae dominated the deepest communities in sixteen of the study lakes.3. Zc was significantly related to Kd(PAR) by the relationship Zc = 4.5/Kd– 2.2.4. From measurements of the photosynthetic properties of Chara corallina (Kl. ex Willd., em R.D.W.) and incident radiation over the course of a year we calculated the depth at which daily net photosynthesis would be equal to zero for each day of the year. An annual average of this depth was significantly related to Zc with anr2 of 0.86.5. Correcting Kd(PAR) for spectral quality and taking into account the potential absorption spectrum of a characean meadow did not improve the relationships.6. We suggest that relationships established between Kd(PAR) and Zc of characean algae in South Island, New Zealand lakes can be explained to a great extent by light limitation of photosynthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2427.1996.00481.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Pedogenic-phreatic carbonates on a Middle Devonian (Givetian) terrigenous alluvial-deltaic plain, Gilwood Member (Watt Mountain Formation), northcentral Alberta, Canada (1998)
    Oxford UK : Blackwell Science Ltd
    Sedimentology 45 (1998), S. 0 
    Details
    ISSN: 1365-3091
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: In the Muskeg Trough of northcentral Alberta the Gilwood Member contains widespread carbonate deposits that formed within terrigenous mudstone and sandstone hosts. Stratigraphic, depositional and petrographic relationships indicate that these carbonates represent calcretes and dolocretes. Calcretes, observed best with cathodoluminescence, display microcrystalline alpha fabrics, circumgranular cracks, root networks, displacive growth fabrics, elongate channel voids and rare coloform growths with flower spar. Similarly, dolocretes have microcrystalline alpha fabrics, brecciation, gradational contacts with host mudstones, extensive layered nodular horizons and are associated with anhydrite and pyrite. δ13C values range between −7‰ to +1‰ and –6‰ to +3‰ for calcretes and dolocretes, respectively. Oxygen isotopes are more variable and differ with host lithologies. δ18O of calcretes ranges between −11‰ to −8‰ for sandstones and −8‰ to −3‰ for mudstones, whereas δ18O of dolocretes ranges between −3‰ to 1‰ for marine mudstones and −6‰ to −2‰ for pedogenic mudstones. Regional mapping indicates that calcretes thicken towards the deepest parts of the Muskeg Trough. Widespread dolocretes extend beyond the eastern and western limits of Muskeg Trough and are useful marker intervals for regional correlations. Dolocretes of restricted lateral extent are found within gleyed palaeosol mudstones next to calcretized channel sandstones.Calcrete isotopic values are interpreted as indicative of carbonate precipitation from waters with meteoric water input. However, the higher δ18O values in dolocretes are indicative of a contribution from an isotopically heavier source such as seawater. Stratigraphically, calcretes are most common along the western and northern edges of Muskeg Trough; thus, calcrete accumulation was further controlled by meteoric water in-flow from the highland to the west and sluggish groundwater flow in Muskeg Trough. In contrast, regionally widespread dolocrete horizons appear to have formed from mixing of fresh waters derived from the highland to the west and seawaters introduced from the east. Regionally restricted dolocretes which are found next to channel sandstones formed from groundwater out-flow from the permeable channel sandstones which resulted in calcretization in channel proximal mudstones and dolomitization in channel distal mudstones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-3091.1998.00192.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...