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  • 1
    Electronic Resource
    Electronic Resource
    Brittle-ductile transition of polymer blends (1995)
    Springer
    Journal of polymer research 2 (1995), S. 217-224 
    Details
    ISSN: 1572-8935
    Keywords: Brittle-ductile transition ; Damage competition criterion ; Polymer blend
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Based on the Ludwik-Davidenkov-Orowan theory, a new criterion of BDT for polymer blends is proposed. In this approach fracture stress (σb) and shear yielding stress (σy) governing the brittle-ductile transition (BDT) of polymer blends is combined into a dimensionless group as Da = σb 2/σy 2. The theory dictates that BDT occurs at a critical condition Dac = 1, brittle fracture occurs when Da 〈 1, and ductile fracture occurs when Da 〉 1. It can be shown that Da = Fg · Lym/LD, where Lym measures the length of shear band of the matrix, LD is a parameter determined by the morphology and interfacial adhesion of dispersed phase, and Fg is related to specimen geometry and other extrinsic parameters. It is suggested that the onset of BDT depends on the competition between the Lym and LD. With due consideration to blend morphology, interfacial adhesion and matrix properties, existing experimental evidence supports the applicability of the proposed criterion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01492773
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  • 2
    Electronic Resource
    Electronic Resource
    The resonance of a vertical rotor containing a transverse crack (1992)
    Springer
    Acta mechanica solida Sinica 5 (1992), S. 167-174 
    Details
    ISSN: 0894-9166
    Keywords: resonance ; crack ; rotor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract In this paper, the numerical calculation and the method of multiple scales are used to investigate the vibrational behavior of a vertical rotor containing a transverse crack with unbalanced excitation. It is found that resonance will occur when the spin speed of the rotor is close to 2/3ωc or 2ωc (ω c is the critical speed of the rotor without crack). It is believed that the phenomenon of parametric resonance may be a basis for crack diagnosing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02207880
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  • 3
    Electronic Resource
    Electronic Resource
    A comparison of the acute effects of a tricyclic and a MAOI antidepressant on septal driving of hippocampal rhythmical slow activity (1994)
    Springer
    Psychopharmacology 114 (1994), S. 337-344 
    Details
    ISSN: 1432-2072
    Keywords: Tricyclic antidepressants ; Monoamine oxidase inhibitors ; Hippocampus ; Rhythmic slow activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In free-moving male rats, the function relating frequency to the threshold current required to drive hippocampal rhythmical slow activity (RSA) with septal stimulation has a minimum at 130 ms. Both classical anxiolytics (e.g. benzodiazepines) and the novel anxiolytic buspirone show similar effects on septal driving of RSA. The tricyclic antidepressant imipramine may be as effective as anxiolytic drugs in treatment of generalized anxiety disorder. The antidepressant monoamine oxidase inhibitor phenelzine has also been reported to be effective in treating anxiety, but this may reflect an action on “atypical depression” rather than “anxiety”. The present study therefore compared the effects of acute administration of imipramine and phenelzine on septal driving of RSA to determine whether either would mimic anxiolytics in this test. Rats were chronically implanted with septal stimulating electrodes and subicular recording electrodes. Three groups of rats received IP injection of either imipramine (5.9–13.3 mg/kg or 13.3–30 mg/kg) or phenelzine (0.2–5.4 mg/kg). The effects produced by imipramine were very similar to the effects produced by anxiolytic drugs. In contrast, the effects produced by phenelzine were essentially opposite to those of both anxiolytic drugs and imipramine. The present experiment suggests that imipramine may act as a true anxiolytic, in addition to its conventional antidepressant properties. In contrast, phenelzine may be effective in cases where the etiology is essentially that of depression even when the symptomatology appears to be that of anxiety.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02244857
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  • 4
    Electronic Resource
    Electronic Resource
    Effects of long-term administration of imipramine on reticular-elicited hippocampal rhythmical slow activity (1991)
    Springer
    Psychopharmacology 105 (1991), S. 433-438 
    Details
    ISSN: 1432-2072
    Keywords: Imipramine ; Rat ; Reticular-elicited hippocampal rhythmical slow activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract All anxiolytics so far tested show a common reduction in the frequency of reticular-elicited hippocampal rhythmical slow activity (RSA). The present experiments tested whether imipramine, an antidepressant drug which has also been used to treat generalized anxiety disorders, shares the common characteristics of anxiolytics on hippocampal RSA. Rats implanted with reticular stimulating electrodes and subicular recording electrodes received both acute and chronic injection of different doses of imipramine. Only relatively high doses (20 and 30 mg/kg, IP) of imipramine produced a reduction in RSA frequency after a single administration. Long-term administration of 20 mg/kg (but not 10 mg/kg, IP) imipramine induced anincrease in baseline RSA frequency but there was no change in the acute frequency-reducing effect of the drug. These results suggest that changes in hippocampal RSA reflect different mechanisms of action for chronic versus acute treatment with antidepressant. It is possible that, at high doses, apparently anxiolytic effects of imipramine may be mediated by similar mechanisms to conventional anxiolytic drugs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02244441
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  • 5
    Electronic Resource
    Electronic Resource
    Dirunal variability and its quantification of subsurface sound scatterers in the western equatorial Pacific (1996)
    Springer
    Journal of oceanography 52 (1996), S. 655-674 
    Details
    ISSN: 1573-868X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract A downwardf-looking acoustic Doppler current profiler (ADCP), suspended by a series of surface and subsurface floats and connecte to an anchroed ship, proided a quite stable platform to measure the, vertical profiles of backscatter strenght *BS) and three components of the velocith from 12 to 22 November 1992 at 1°30′S and 156°15′E, in the Intensive Flux Array (IFA) of TOGA/COARE. While the variability of the horizontal velocity was controlled by the semi-diurnal tide, BS and vertifal velocity were dominated by diurnal variability probably caused by the diel migration of zooplakton. The downward migration occurred early in the moring (0500–0700 in local time) and the upward one late in the afternoon (1700–1900). The average values of about 4 cm s−1 for the sinking and rising speed were estimated from Doppler shift and BS isopleth displacement. The subsurface chlorophyll maximum (SCM) coincident with the top of the thermocline at 80–100 m was also detectable in the BS data during daytime when almost no migrating zooplankton remained in the upper 300 m. Backscatter signals from the SCM and thermocline were separated by corrlating the BS data with the chlorophylla and temperature data. The maximum contribution of the migrating zooplanktion, passively drifting phytoplankton and temperature gradient on BS was estimated to be 14.8, 7.0, 5.1 dB, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02238326
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  • 6
    Electronic Resource
    Electronic Resource
    Diurnal Cycle of Sound Scatterers and Measurements of Turbidity Using ADCP in Beppu Bay (2000)
    Springer
    Journal of oceanography 56 (2000), S. 559-565 
    Details
    ISSN: 1573-868X
    Keywords: Diurnal cycle of backscatter strength ; Beppu Bay ; bottom-mounted ADCP ; zooplankton ; turbidity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract From September 20 to 22 in 1994, the vertical profiles of echo intensity and three-component velocities were measured with a bottom-mounted 300 kHz broadband acoustic Doppler current profiler (ADCP) in Beppu Bay in the Seto Inland Sea of Japan. A very strong thermocline was observed from 50 to 60 m. A pronounced diurnal cycle of backscatter strength (BS) was found above the thermocline. However, it was not found under the thermocline where there was a lack of dissolved oxygen. We suggest that the diurnal cycle of BS is caused by the vertical migration of zooplankton. The downward and upward migration occurred in early morning and late afternoon, respectively. The migration speeds estimated from BS isopleth displacements were about 1 cm s−1. Further, the contribution of turbidity (Tur) to BS was examined by separating out the effect of migrating zooplankton. There was a significant correlation between BS and turbidity under the thermocline. The maximum contributions of the Tur, migrating zooplankton and non-migrating plankton on BS were estimated at 3, 12, 25 dB, respectively. These data suggest that when using an ADCP to estimate Tur, it is very important to consider carefully the backscatter signal from zooplankton.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011105228526
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  • 7
    Electronic Resource
    Electronic Resource
    Finline L to Q band upconverter (1995)
    Springer
    International journal of infrared and millimeter waves 16 (1995), S. 1415-1418 
    Details
    ISSN: 1572-9559
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract An L to Q band upconverter using finline configuration is developed. The conversion losses of 9.45±0.35 dB are achieved over 400MHz bandwidth. A more effective 180° hybrid and a planar backshort are used in the finline upconverter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02069553
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  • 8
    Electronic Resource
    Electronic Resource
    The Application of Genetic Algorithm in E-Plane Waveguide Filter Design (2000)
    Springer
    International journal of infrared and millimeter waves 21 (2000), S. 303-308 
    Details
    ISSN: 1572-9559
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Traditional optimization methods, such as Powell's method and the Simplex method, are generally very difficult to design high performance filters with the relative band-width less than 0.15% or more than 10%. In this paper, Genetic Algorithm (GA) is used to design filters that meet these requirements. Two special filters are designed in this paper with the relative band-width as 0.15% and 25%, respectively. The numerical results demonstrate that GA can be used to design filters of superior quality when compared to the filters designed by using Powell's method or Simplex method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006617304824
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  • 9
    Electronic Resource
    Electronic Resource
    Can TMS and DSS be used as NMR references for cyclodextrin species in aqueous solution? (1993)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 15 (1993), S. 37-42 
    Details
    ISSN: 1573-1111
    Keywords: Cyclodextrin ; DSS ; inclusion complex ; NMR ; TMS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Tetramethylsilane (TMS) can be included by β-cyclodextrin (β-CD), and sodium 2,2-dimethylsilapentane-5-sulphonate (DSS) can form inclusion complexes with β- and γ-CD. The NMR chemical shifts are changed considerably as a result of the strong interaction between CD and the guest compound in the inclusion complexes. A downfield shift of as much as 0.63 ppm shift downfield has been observed for the protons of external TMS in CD aqueous solution. In view of this, the question arises of whether TMS and DSS can be used as internal references. DSS in D2O is suggested as an external reference for aqueous cyclodextrin solution in NMR measurements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00706472
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  • 10
    Electronic Resource
    Electronic Resource
    A study of vitamin A as a probe in critical micelle concentration determinations of surfactants (1994)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 17 (1994), S. 37-44 
    Details
    ISSN: 1573-1111
    Keywords: CMC ; inclusion ; micelle ; probe ; vitamin A
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The critical micelle concentrations (CMC) of some sodium alkyl sulfates (SNS, SdS, SDS, STS, and SHS), sodium dodecyl sulfonate (SDSO), CTAB and Triton X-100 were determined by measuring both the absorbance and the absorption wavelength of vitamin A in aqueous solutions of surfactants of various concentrations. The results are in agreement with those obtained by other methods in the literature. The influence of micelles upon the absorption spectra of vitamin A have been investigated. The effects of the temperature and the incubation time on the measurements have been discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00707998
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