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
  • 11
    Electronic Resource
    Electronic Resource
    Molecular beam epitaxial growth of CdZnS using elemental sources (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 2935-2937 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report on the first molecular beam epitaxial (MBE) growth of CdZnS on (100) GaAs substrates using elemental Zn, Cd, and S sources. Single crystal cubic CdZnS layers lattice matched to GaAs have been successfully prepared. The competition in incorporation between Cd and Zn under different sulfur flux conditions is investigated. Under appropriate growth conditions, the Cd1−xZnxS composition is directly related only to the ratio of the group II beam equivalent pressures. The background sulfur in the MBE growth chamber is found to etch the freshly thermally cleaned GaAs substrates and generate high density of pits on the surfaces. Methods to prevent the sulfur etching are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.110278
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Heavily doped p-ZnSe:N grown by molecular beam epitaxy (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 59 (1991), S. 2992-2994 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The growth of p-ZnSe:N films by molecular-beam epitaxy, employing a free radical nitrogen source, has been investigated. Using this technique we have obtained p-type ZnSe with net acceptor concentrations up to 1.0×1018 cm−3, as measured by capacitance–voltage(C–V) profiling−this is the highest ever reported for p-type ZnSe. By adjusting the flux of active nitrogen and the substrate temperature, films with net acceptor concentrations from 1.0×1016 to 1.0×1018 cm−3 were grown. Evidence of compensation was found in the low temperature photoluminescence and C–V measurements; the degree of compensation depends on the amount of nitrogen incorporated into the film. The dependencies of nitrogen density, net acceptor concentration, and degree of compensation upon the flux of active nitrogen and the substrate temperature are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.105821
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Wide band gap MgZnSSe grown on (001) GaAs by molecular beam epitaxy (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 66 (1995), S. 3462-3464 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report molecular beam epitaxial study of wide band gap ((approximately-greater-than)2.9 eV at room temperature) MgZnSSe on (001) oriented GaAs using ZnS, Mg, Zn, and Se sources. Although the growth is under group II rich condition, the compositions of S and Mg in the MgyZn1−ySxSe1−x are linear functions of flux ratios, PZnS/PSe and PMg/PZnS, up to 35%, respectively. Mirrorlike surface and low defect density (5×104 cm−2) MgZnSSe with band gap close to 3.1 eV can be achieved. Composition modulation, tweedlike contrasts and strain contrasts in the MgZnSSe are observed from transmission electron microscope analysis. For the first time, a miscibility gap at high S and Mg compositions is reported. Nitrogen-free radicals are used as the p-type dopant for the doping study. For the MgZnSSe with room-temperature band gap energy higher than 2.9 eV, the net acceptor concentration decreases as the band gap energy increases. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.113388
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Photodegradation of CdxZn1−xSe quantum wells (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 66 (1995), S. 358-360 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Photoluminescence imaging was used to study photodegradation in CdZnSe quantum wells, important to II-VI based blue-green light emitter technology. The observed degradation microstructure evolves similarly to features observed during CdZnSe based LED and laser operation. Degradation is shown to emanate from pre-existing defects to form dark line defects along the 〈100〉 directions. We report an observation of a mobile defect in II-VI materials that is the precursor to the 〈100〉 dark line defects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.114212
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Role of stacking faults as misfit dislocation sources and nonradiative recombination centers in II-VI heterostructures and devices (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 3023-3025 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have investigated the role of stacking faults in high quality ZnSxSe1−x heterostructures and a ZnSxSe1−x/CdxZn1−xSe based II-VI blue-green quantum well laser structure grown on GaAs substrates. We find that these stacking faults, which originate at the epilayer/substrate interface during the initial stages of the growth, act as sources for misfit dislocation formation in the quantum well region of ZnSxSe1−x/CdxZn1−xSe based devices. We have analyzed the formation mechanism of these dislocations. We also show through cathodoluminescence microscopy that these stacking faults act as nonradiative recombination centers which therefore reduce the luminescence of these devices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.110246
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Degradation of II-VI based blue-green light emitters (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 3107-3109 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have carried out the first detailed structural studies of degradation in II-VI blue-green light emitters. Electroluminescence and transmission electron microscopy studies carried out on light emitting diodes fabricated from quantum well laser structures and electroluminescence studies on stripe laser structures show that degradation occurs by the formation and propagation of crystal defects. The studies indicate that room temperature cw lasing in such structures is possibly prevented by the rapid formation of such defects at the high current densities required for lasing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.110218
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Molecular mapping of a new gene for resistance to frogeye leaf spot of soya bean in ‘Peking’ (2001)
    Oxford, UK : Blackwell Publishing Ltd
    Plant breeding 120 (2001), S. 0 
    Details
    ISSN: 1439-0523
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Amplified fragment length polymorphism (AFLP) and microsatellite (simple sequence repeat, SSR) techniques were used to map the _RGSpeking gene, which is resistant to most isolates of Cercospora sojina in the soya bean cultivar ‘Peking’. The mapping was conducted using a defined F2 population derived from the cross of ‘Peking’(resistant) בLee’(susceptible). Of 64 EcoRI and MseI primer combinations, 30 produced polymorphisms between the two parents. The F2 population, consisting of 116 individuals, was screened with the 30 AFLP primer pairs and three mapped SSR markers to detect markers possibly linked to RcsPeking. One AFLP marker amplified by primer pair E-AAC/M-CTA and one SSR marker Satt244 were identified to be linked to ResPeking. The gene was located within a 2.1-cM interval between markers AACCTA178 and Satt244, 1.1 cM from Satt244 and 1.0 cM from AACCTA178. Since the SSR markers Satt244 and Satt431 have been mapped to molecular linkage group (LG) J of soya bean, the ResPeking resistance gene was putatively located on the LG J. This will provide soya bean breeders an opportunity to use these markers for marker-assisted selection for frogeye leaf spot resistance in soya bean.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1439-0523.2001.00563.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Optimization of DNA amplification fingerprinting techniques to study genetic relationships of white lupin germplasm (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Plant breeding 114 (1995), S. 0 
    Details
    ISSN: 1439-0523
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: DNA amplification fingerprinting (DAF) techniques were used to evaluate genetic relationships among 24 randomly selected white lupin (Lupinus albus L.) accessions originating from four endemic regions. Parameters affecting DAF were optimized to obtain high resolution and reproducible banding patterns. DNA amplification was tolerant to a wide range of both template and primer concentrations but sensitive to Mg2+ concentration, and annealing temperature and time. Pure template DNA was found to be essential for obtaining reproducible banding patterns. Primer annealing occurred at multiple sites, permitting detection of polymorphism using only a single primer. Of 56 octamer primers tested, 22 yielded highly polymorphic DAF bands that could be used to distinguish closely related accessions. Genetic similarity coefficients were calculated and a dendrogram, using the unweighted pair group method with arithmetic average (UPGMA), was constructed. A high level of genome diversity was found among the accessions, but several from the Middle East and West Africa tended to cluster together. The results support the future use of DAF markers for the characterization and identification of white lupin germplasm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1439-0523.1995.tb00849.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Deep levels in Ga-doped ZnSe grown by molecular-beam epitaxy (1989)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 66 (1989), S. 3656-3660 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Results of a deep-level transient spectroscopy study of Ga-doped ZnSe thin films grown by molecular-beam epitaxy are presented. Two prominent deep levels were observed in all the samples investigated. The concentration of the trap detected at 0.34 eV below the conduction-band edge was essentially independent of the doping concentration and is attributed to native defects arising from Se vacancies in the ZnSe films. The second level with an activation energy of 0.26 eV shows a very strong doping dependence and is tentatively identified as arising from dopant-site (gallium-on-zinc-site) defects complexed with selenium vacancies. Preliminary results also indicate that planar doping of ZnSe significantly reduces the concentration of the Ga-vacancy complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.344077
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Human milk lactoferrin is a serine protease that cleaves Haemophilus surface proteins at arginine-rich sites (2003)
    Oxford, UK : Blackwell Science Ltd
    Molecular microbiology 47 (2003), S. 0 
    Details
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Lactoferrin is a member of the lactotransferrin family of non-haem, iron-binding glycoproteins and is found at high concentrations in all human secretions, where it plays a major role in mucosal defence. In recent work, we observed that lactoferrin has proteolytic activity and attenuates the pathogenic potential of Haemophilus influenzae by cleaving and removing two putative colonization factors, namely the IgA1 protease protein and the Hap adhesin. Experiments with protease inhibitors further suggested that lactoferrin may belong to a serine protease family. In the present study we explored the mechanism of lactoferrin protease activity and discovered that mutation of either Ser259 or Lys73 results in a dramatic decrease in proteolysis. Examination of the crystal structure revealed that these two residues are located in the N-terminal lobe of the protein, adjacent to a 12–15 Å cleft that separates the N-lobe and the C-lobe and that can readily accommodate large polypeptide substrates. In additional work, we found that lactoferrin cleaves IgA1 protease at an arginine-rich region defined by amino acids 1379–1386 (RRSRRSVR) and digests Hap at an arginine-rich sequence between amino acids 1016 and 1023 (VRSRRAAR). Based on our results, we conclude that lactoferrin is a serine protease capable of cleaving arginine-rich sequences. We speculate that Ser259 and Lys73 form a catalytic dyad, reminiscent of a number of bacterial serine proteases. In addition, we speculate that lactoferrin may cleave arginine-rich sequences in a variety of microbial virulence proteins, contributing to its long-recognized antimicrobial properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2958.2003.03327.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...