ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
Filter
Collection
Keywords
Publisher
Years
  • 1
    Electronic Resource
    Electronic Resource
    Development of ECR ion sources in China (invited) : The 8th international conference on ion sources (2000)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 71 (2000), S. 646-650 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Recent development of electron cyclotron resonance (ECR) ion sources in China is reviewed. Emphasis is put on high charge state ECR ion sources which have been mainly developed in China by Institute of Modern Physics (IMP). Presently two ECR ion sources built by IMP for highly charged ion beams are put into operation for cyclotrons and atomic physics research. The development of high charge state ECR ion sources at IMP has progressed with a new magnetic field configuration, better condition for extraction of highly charged ions, high mirror magnetic field, large plasma volume, and special techniques to provide extra cold electrons. These techniques greatly enhance the production of highly charged ions from IMP ECR ion sources. So far more than 185 eμA of Ar11+ and 50 eμA of Xe26+ were produced by the IMP ECR ion sources. The metallic ion beam production was tested and the first beam 40Ca11+ was provided to the cyclotrons at IMP. The beam intensity of 40Ca11+ could reach 130 eμA. The next part of this article will report the latest progress of 2.45 GHz ECR ion sources in China. A 2.45 GHz compact permanent magnet proton ion source was designed and constructed by IMP. A new microwave feeding system is applied on this ion source. The ion source is able to deliver 90 mA of mixed ion beam (H1++H2++H3+) after preliminary commissioning. The article also mentions a small 2.45 GHz ECR ion source which was built by Sichuan University and used for industry applications. The dependence of plasma density and electron temperature on radio frequency power, neutral gas pressure, and different microwave windows was measured by a Langmuir probe on this ion source. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1150337
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Surface modification of magnetic recording heads by plasma immersion ion implantation and deposition (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 1656-1664 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Plasma immersion ion implantation and deposition is a novel process for surface modification. By combining plasma deposition and ion implantation and using filtered vacuum arc plasmas, thin film formation, direct and recoil ion implantation, and ion-beam-assisted intermixing of the film and substrate can be accomplished simultaneously. The implications of this technique in tribology of magnetic recording media have been investigated experimentally. Surfaces of Al2O3-TiC heads were modified with silver, carbon, and titanium ions at doses of 3×1016 ions/cm2 and mean implantation energies between 2.0 and 4.2 keV. Simulation results indicated that the modified regions exhibited high concentrations of implanted species in the top 2–3 nm, atomically mixed interfaces, and thicknesses between 10 and 25 nm. Surface imaging with an atomic force microscope and nanoindentation testing revealed that the modified heads possessed smoother topographies and increased hardnesses. Contact start-stop and continuous sliding experiments with modified heads and carbon-coated magnetic rigid disks and microscopy observations demonstrated that significant enhancement of the friction and wear characteristics can be achieved with the present surface modification technique. The possible reasons for the improved tribological behavior and the predominant mechanisms during contact start-stop and continuous sliding are interpreted in light of the obtained experimental results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358516
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Erratum: "Surface modification of magnetic recording heads by plasma immersion ion implantation and deposition'' [J. Appl. Phys. 76, 1656 (1994)] (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 3223-3223 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358541
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Nitrogen-induced modifications in microstructure and wear durability of ultrathin amorphous-carbon films (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 2491-2499 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A systematic experimental investigation was carried out to understand the effects of nitrogenation on the microstructure and wear durability of thin amorphous-carbon films. The films were fabricated with 0%, 10%, 15%, 20%, 30%, 40%, and 50% N2 in the sputter gas. Microstructure properties were characterized using Rutherford backscattering spectroscopy, electrical resistance, Raman spectroscopy, and x-ray photoelectron spectroscopy. Nanohardness and scratch wear resistance of the films were studied with an atomic force microscope equipped with a diamond tip. The head–disk interface tribological properties of the films were tested with industrial standard contact–start–stop wear instrumentation. The results indicate that the introduction of nitrogen into the carbon film increases the film lattice disorder and allows for the formation of carbon–nitrogen single, double, and triple bonds. The nitrogen atomic concentration in the film, electrical resistance, and the ratio of carbon–nitrogen bonds to carbon–carbon bonds increase with increasing N2 in the sputter gas. A significant addition in C(Triple Bond)N bond percentage is observed when the N2 exceeds 30% in the sputter gas. Both the nanohardness and scratch wear resistance of the carbon film can be significantly improved by incorporating an optimized nitrogen concentration in the film. In this study, the film processed with 30% N2 showed the highest nanohardness and wear resistance. The degraded nanowear resistance for the films processed with 40% and 50% N2 is attributed to the significant addition of C(Triple Bond)N bonds. Within a wide process range (15%–30% N2), the films exhibit excellent tribological performances at the head–disk interface. The wear mechanisms from the contact–start–stop wear tests are interpreted based on the understanding of film structures and film mechanical properties. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.367009
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Rapid eutectic growth under containerless condition (2002)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 81 (2002), S. 778-780 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Rapid eutectic growth in a highly undercooled liquid was accomplished by containerlessly processing Co–Mo eutectic alloy in a drop tube. The containerless state during free fall produces substantial undercoolings up to 391 K (0.24TE) in falling droplets before crystallization. The eutectic growth mechanism is found to transform from lamellar eutectic to anomalous eutectic if the droplet undercooling exceeds a critical value of about 56 K, which coincides well with the lower boundary of the calculated eutectic coupled zone. Although the reduced gravity level of 10−2–10−3 g has little influence on this eutectic growth mechanism transition, it frequently results in the formation of spherical anomalous eutectic grains owing to the symmetrical temperature field and concentration field surrounding solid/liquid interface. Both theoretical analyses and experimental observations indicate that the independent nucleation and cooperative branched growth of two eutectic phases are responsible for the eutectic growth mechanism transition. The three-dimensional structural model of anomalous eutectic grain is a two-phase composite dendrite. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1492855
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Substrate-site selective growth of aligned carbon nanotubes (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 3764-3766 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report highly substrate-site selective growth of carbon nanotubes by chemical vapor deposition from precursors of ferrocene and xylene mixtures. The technique allows us to grow well-aligned multiwalled carbon nanotubes preferentially on the SiO2 regions of patterned SiO2/Si substrates prepared by conventional lithography. This eliminates the catalyst predeposition step in the fabrication process. This simple approach may also be applied to build large-scale networks of organized nanotubes on planar substrates. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1330751
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Specific heat and thermodynamic properties of undercooled liquid cobalt (2002)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 80 (2002), S. 28-30 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Co is undercooled to 227 K (0.128 Tm) and its specific heat has been determined as 40.6 Jmol−1 K−1 by electromagnetic levitation drop calorimeter, whose good accuracy is verified by the measured specific heat data of pure nickel. On the basis of measured specific heat data, the thermodynamic properties, such as thermodynamic driving force and relative nucleation rate, are calculated. Moreover, the theoretical models of Turnbull and Dubey–Ramachandrarao are also used to calculate the thermodynamic properties for a comparison. It is found that both the thermodynamic driving force and relative nucleation rate have large deviation compared with the calculated results based on experimental data. This indicates that, since the deviation of specific heat value has a drastic influence on thermodynamic driving force and nucleation rate for the undercooled liquid metals, it is necessary to measure the specific heat quantitatively by experiments. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1428409
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Reliability and current carrying capacity of carbon nanotubes (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 79 (2001), S. 1172-1174 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The current-carrying capacity and reliability studies of multiwalled carbon nanotubes under high current densities (〉109 A/cm2) show that no observable failure in the nanotube structure and no measurable change in the resistance are detected at temperatures up to 250 °C and for time scales up to 2 weeks. Our results suggest that nanotubes are potential candidates as interconnects in future large-scale integrated nanoelectronic devices. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1396632
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Parametric study of single-axis acoustic levitation (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 79 (2001), S. 881-883 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Remarkable enhancement of the single-axis acoustic levitation force is achieved by properly curving the surface and enlarging the section of the reflector so as to levitate high density material like tungsten (ρs=18.92 g/cm3). A two-cylinder model incorporating the boundary element method simulations is presented for systematic study of the relationship between levitation capabilities and geometric parameters. The model proves to be successful in predicting resonant modes and explaining deviation of the levitated samples near the reflector and driver. The dependence of levitation force on resonant mode, reflector section radius Rb and curvature radius R is revealed and summarized, which agrees with the experiment in principle and suggests that a reflector with large Rb and small R (when Rb/λ≥0.982) working under mode 1 assures better levitation capabilities. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1391398
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    EXPRESSION OF I-Aαk AND ALLELIC RESTRICTION ON Aα/Aα PAIRING IN TRANSGENIC MICE (1990)
    Oxford, UK : Blackwell Publishing Ltd
    International journal of immunogenetics 17 (1990), S. 0 
    Details
    ISSN: 1744-313X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Cell surface expression of class II major histocompatibility complex encoded (la) molecules depends on association of the component α and β chain into a stable heterodimer. Studies on cell lines transfected with MHC class II genes have revealed important limitations on the assembly of haplotype-mismatched Aα:Aβ complex. In order to study α: β chain pairing restrictions in vivo a number of lines of transgenic mice carrying the Aαk gene were generated. The transgene was studied in the context of H-2b, H-2s, H-24, H-2u, H-2f and H-2v haplotypes. Initial FACS analysis of spleen and peripheral blood cells showed no Aαk expression. Spleen cells stimulated with LPS and analysed by FACS showed Aαk expression in three different H-2b strains as well as H-2u, but not in others. These data indicate that Aαk can associate with Aβb and Aαk, but not with Aβs,Aβq, Aβf, Aβv.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1744-313X.1990.tb00867.x
    Location Call Number Expected 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...