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  • 1
    Electronic Resource
    Electronic Resource
    4-(1,4-Dimethoxy-2-naphthyl)-4- hydroxycyclohexanone and its ethylene ketal (1999)
    Springer
    Journal of chemical crystallography 29 (1999), S. 955-959 
    Details
    ISSN: 1572-8854
    Keywords: crystal structure ; intramolecular hydrogen bond ; 4-(1,4-dimethoxy-2-naphthyl)-4-hydroxycyclohexanone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Intramolecular hydrogen bonding in the solid state is reported for the title compound and its ethylene ketal. The title compound crystallizes in the triclinic space group, $$P\bar 1$$ with a = 9.590(3), b = 9.620(3), c = 9.844(2) Å, α = 97.67(2), β = 105.25(2), γ = 115.47(2), and Z = 2. The ethylene ketal crystallizes in the monoclinic space group, P21/c, with a = 7.230(2), b = 22.639(3), c = 10.839(2) Å, β = 101.47(2), and Z = 4. The intramolecular hydrogen bond length of 1.79 Å is the same for the ketone and ketal, but the O—H---O valence angle is 144° for the ketone and 165° for the ketal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009538414801
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  • 2
    Electronic Resource
    Electronic Resource
    Thermodynamic Analysis of Nb-Cr Powders of Mechanical Alloying (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Advanced materials research Vol. 26-28 (Oct. 2007), p. 181-184 
    Details
    ISSN: 1662-8985
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: In this study, Nb-Cr binary mixtures were prepared by mechanical alloying. Andmechanical alloying process of mixed Nb-Cr(1:2) powders was studied, and the phases of millingpowders analyzed by XRD and SEM. It has been found that the powders form solid solution first, thenamorphous phase appeared gradually and crystallization of amorphous takes place with the differentmilling time. A thermodynamic model of MA of Nb-Cr system was developed based on MiedemaSemi-experimental theory to explain the phase transformations of Nb-Cr system during milling.Using Miedema semi-empirical model the free energies of the ordered Laves-phase NbCr2intermetallics, solid solution and amorphous alloy were calculated. From XRD and SEM analysis ofNb/2Cr powders prepared by mechanical alloying in a planetary ball milling, it was found that thecalculated results were in accordance with the experiments
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/39/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.26-28.181.pdf
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  • 3
    Electronic Resource
    Electronic Resource
    A Relation between the Positron Lifetime and Temperature in C〈sub〉60〈/sub〉 (1994)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 175-178 (Nov. 1994), p. 387-390 
    Details
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/00/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.175-178.387.pdf
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  • 4
    Electronic Resource
    Electronic Resource
    Microwave Dielectric Properties of A-Site Modified Pb(Mg〈sub〉1/2〈/sub〉W〈sub〉1/2〈/sub〉)O〈sub〉3〈/sub〉 (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 280-283 (Feb. 2007), p. 1-4 
    Details
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The sintering behavior, microstructure and microwave dielectric properties of A-site modified Pb(Mg1/2W1/2)O3 with Ca2+, Ba2+and La3+ were investigated in this paper. It is discovered that a series of single-phase perovskite type solid solutions with A-site vacancies were formed for Pb1-3/2xLax(Mg1/2W1/2)O3 (0 £ x £ 2/3)). The solid solution took cubic perovskite type structure (Fm3m)with random distribution of A-site vacancies when 0 〈 x 〈 0.5, and tetragonal or orthorhombic structure with the ordering of A-site vacancies when 0.5 £ x £ 2/3. However, the solid solubility of Ba(Mg1/2W1/2)O3 and Ca(Mg1/2W1/2)O3 in Pb(Mg1/2W1/2)O3 is limited to 15 and 5 mol%, respectively, in spite of no structural difference between the end member. It was also found that the A-site substitution with Ca2+, Ba2+and La3+ for Pb2+ has no influences on the degree of B-site ordering between Mg2+ and W6+. However, the antiferroelectric Tc decreases with increase in the content of A-site substitution. The dielectric constants and temperature coefficient of resonant frequency of La3+ modified Pb(Mg1/2W1/2)O3 are much lower than that of. Ca2+and Ba2+ modified Pb(Mg1/2W1/2)O3, and decrease with increasing La content. However, its Q×f values is much higher than that of Ca2+and Ba2+ modified Pb(Mg1/2W1/2)O3,and increase with increase in La content. Relatively good combination microwave dielectric properties were obtained for Pb1-3/2xLax(Mg1/2W1/2)O3 with x=0.56: er=28.7, Q×f=18098, and tf=-5.8ppm/oC
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/48/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.280-283.1.pdf
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  • 5
    Electronic Resource
    Electronic Resource
    Key Issues in Measuring the Velocities of Nanoparticles in Nanofluids (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 364-366 (Dec. 2007), p. 1111-1116 
    Details
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Our recent work [1] theoretically revealed that speckles can be formed when nanofluidscontaining a modest volume fraction of nanoparticles are illuminated by a monochromatic laserbeam. This paper focuses on the key issues, including the experimental setup, the particle volumefraction of the nanofluid, the flow velocity of the nanofluid and the diameter of the pipe, inmeasuring the velocities of nanoparticles in nanofluids with laser speckle velocimetry (LSV). Firstan experimental setup is established according to the optical characteristics of nanoparticle and themeasuring principles of particle image velocimetry (PIV) and LSV. Then a conclusion is made fromthe experimental results that clear speckle patterns can be formed when the particle volume fractionis between 0.0005% and 0.002% is able to form. Finally, in order to make it applicable to utilizeLSV to measure the velocities of nanoparticles in nanofluids that flow in pipe, nanofluids can notflow too fast and the diameter of the pipe should not be too small
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/56/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.364-366.1111.pdf
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  • 6
    Electronic Resource
    Electronic Resource
    Experimental Study on the Detection of Surface-Breaking Defects on Metal with the Scanning Laser Line Source Technique (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 364-366 (Dec. 2007), p. 1117-1122 
    Details
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The scanning laser line source (SLLS) technique is a novel laser-based inspection methodfor the ultrasonic detection of small surface-breaking defects. The SLLS approach is based onmonitoring the change in laser generated ultrasound as a laser line source is scanning over a defect.It has provided enhanced signal-to-noise performance compared to the traditional pitch-catch orpulse-echo ultrasonic methods. In this paper, an experimental method is presented to detect surfaceacoustic waves (SAW) with polyvinylindene fluoride(PVDF) transducer. The ultrasonic signal isconverted into electric signal by piezoelectricity of the PVDF, which is attached to a micro-knifeedge clamped on a metal device. The SAW are excited by employing a pulsed Nd:YAG laser onaluminum plate with artificial surface-breaking defects. The laser line source is accurately shiftedby the motorized translation stage, while the PVDF is located at a fixed position on the specimen.When the laser line source is scanning over the defect, the ultrasonic signals are monitored,meanwhile the characteristic changes in the amplitude and frequency content are observed.Consequently, the position of the defect can be determined by analyzing the obtained signals. Theexperimental system with high sensitivity provides a detection method of small surface-breakingdefects on metal and gives convincing experimental evidence for the interaction mechanismbetween the SAW and the surface-breaking defects
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/56/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.364-366.1117.pdf
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  • 7
    Electronic Resource
    Electronic Resource
    Tat peptide-derivatized magnetic nanoparticles allow in vivo tracking and recovery of progenitor cells (2000)
    [s.l.] : Nature America Inc.
    Nature biotechnology 18 (2000), S. 410-414 
    Details
    ISSN: 1546-1696
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: [Auszug] The ability to track the distribution and differentiation of progenitor and stem cells by high-resolution in vivo imaging techniques would have significant clinical and research implications. We have developed a cell labeling approach using short HIV-Tat peptides to derivatize superparamagnetic ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/74464
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  • 8
    Electronic Resource
    Electronic Resource
    Genetic Diversity in Crucian Carp (Carassius auratus) (1999)
    Springer
    Biochemical genetics 37 (1999), S. 267-279 
    Details
    ISSN: 1573-4927
    Keywords: CARASSIUS AURATUS ; TETRAPLOID ; HEXAPLOID ; MITOCHONDRIAL DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A survey of restriction fragment polymorphism inmitochondrial DNA of three subspecies of Carassiusauratus throughout four provinces in China wasundertaken using 17 restriction enzymes. Two carp,Cyprinus carpio rubbrofuscus and Cyprinuscarpio carpio, were included as the outgroup. Atotal of 16 haplotypes was observed: 5 in tetraploids ofC. auratus auratus; 8 in hexaploids of C.auratus auratus; and 2 in C. auratus gibelio and C.auratus cuvieri, respectively. The tetraploids andhexaploids share three common haplotypes as I, V, andVI. C. a. Cuvieri may have diverged first amongthe three subspecies. Interestingly, C. a. auratus andC. a. cuvieri did not form monophyletic clades,which indicated that the classification of Carassiusauratus required further studies. The currenthypothesis, that hexaploids originated from tetraploids by a polyploidyevent, is less favorable, based on the distribution ofhaplotypes and the lower diversity in tetraploids thanin hexaploids. Our data also indicate that divergence of hexaploids and tetraploids might be recentand mtDNA polymorphism existed before the divergence.Meanwhile, genetic isolation exists between thehexaploids and the tetraploids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018751008848
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