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  • 1
    Electronic Resource
    Electronic Resource
    Gas source molecular-beam epitaxy of Si and SiGe using Si2H6 and GeH4 (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 1008-1012 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Gas source molecular-beam epitaxy (MBE) has been studied as a low-temperature Si and SiGe epitaxial method. Specular single-crystalline silicon films were successfully grown by the gas source Si MBE technique at a substrate temperature of about 650 °C. N-type doping was carried out using PH3 gas as a dopant and the maximum electron concentration of 2.9x1019cm−3 was obtained. Furthermore, p-type doping using B2H6 gas was carried out for the first time and the maximum hole concentration of 9.5×1017cm−3 was successfully achieved. The SiGe alloy layer was also grown by the gas source MBE technique using GeH4 as a Ge source gas. The Ge concentration of the sample could be precisely controlled by the molar fraction of Ge in supply and it was increased up to 0.30 with increasing the gas ratio of GeH4 to Si2H6.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.347415
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  • 2
    Electronic Resource
    Electronic Resource
    Extremely low non-alloyed specific contact resistance ρc (10−8 Ω cm2) to metalorganic molecular beam epitaxy grown super heavily C-doped (1021 cm−3) p++GaAs (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 8227-8232 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The specific contact resistance ρc of non-alloyed ohmic metals (Mo/Au and WSix) to p-type GaAs is evaluated by transmission line method (TLM) patterns for various doping concentrations from 8×1018 to 1021 cm−3. The obtained specific contact resistance ρc, less than 10−8 Ω cm2, to metalorganic molecular beam epitaxy grown C-doped ( 1021 cm−3) GaAs is the lowest reported value. From the application point of view for the emitter electrodes of PNp type (two-dimensional electron gas base) heterojunction bipolar transistors, the specific contact resistance of a refractory metal, or the sputter-deposited WSix (x=0.45), is also studied. By reducing the growth temperature of molecular beam epitaxy from 600 to 450 °C and enhancing the As4/Ga flux ratio to 15, a nondiffusive heavily Be doped (1020 cm−3) GaAs is obtained. The specific contact resistance of the WSix to this sample is less than 10−6 Ω cm2. The obtained specific contact resistance can be well explained by a simple modeling based on the tunneling transport of light holes. Secondary ion mass spectroscopy analysis of the depth profile under heat acceleration shows a small diffusion of dopants for Be doped (1020 cm−3) GaAs and C-doped (1021 cm−3) GaAs. In addition, the specific contact resistance ρcISO of the isoheterojunction (p+GaAs/p+AlxGa1−xAs) is also evaluated by TLM patterns.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.347427
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Repetitive flash x-ray generator utilizing a simple diode with a new type of energy-selective function (1990)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 61 (1990), S. 2343-2348 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The construction and the fundamental studies of a repetitive flash x-ray generator having a simple diode with an energy-selective function are described. This generator consisted of the following components: a constant high-voltage power supply, a high-voltage pulser, a repetitive high-energy impulse switching system, a turbo molecular pump, and a flash x-ray tube. The circuit of this pulser employed a modified two-stage surge Marx generator with a capacity during main discharge of 425pF. The x-ray tube was of the demountable-diode type which was connected to the turbo molecular pump and consisted of the following major devices: a rod-shaped anode tip made of tungsten, a disk cathode made of graphite, an aluminum filter, and a tube body made of glass. Two condensers inside of the pulser were charged from 40 to 60 kV, and the output voltage was about 1.9 times the charging voltage. The peak tube voltage was primarily determined by the anode-cathode (A-C) space, and the peak tube current was less than 0.6 kA. The peak tube voltage slightly increased when the charging voltage was increased, but the amount of change rate was small. Thus, the maximum photon energy could be easily controlled by varying the A-C space. The pulse width ranged from 40 to 100 ns, and the x-ray intensity was less than 1.0 μC/kg at 0.3 m per pulse. The repetitive frequency was less than 50 Hz, and the effective focal spot size was determined by the diameter of the anode tip and ranged from 0.5 to 3.0 mm in diameter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1141958
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  • 4
    Electronic Resource
    Electronic Resource
    Disktron accelerator (1993)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 64 (1993), S. 2466-2474 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A new type of low-energy ion accelerator has been developed. It includes an eight-storied Disktron generator, newly developed accelerating tubes which hold up to 4 MV/m, both single and tandem acceleration capability, and a compound negative ion source. The Disktron generates 3.2 MV with a dummy load and 2.2 MV with ion beams, and has a voltage stability better than 10−3 at around 1 MV with a corona feedback stabilizer or a generating voltmeter feedback stabilizer only. The highly stabilized voltage of the Disktron has particularly been allowed to form an ion microbeam of about 1-μm diameter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1143905
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  • 5
    Electronic Resource
    Electronic Resource
    Gonadotropin-releasing hormone stimulates phospholipase C but not protein phosphorylation/dephosphorylation in plasma membrane from human epithelial ovarian cancer (1993)
    238 Main Street, Cambridge, Massachusetts 02142, USA : Blackwell Scientific Publications
    International journal of gynecological cancer 3 (1993), S. 0 
    Details
    ISSN: 1525-1438
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: In view of advances in treatment of certain hormone-dependent cancers with analogues of gonadotropin-releasing hormone (Gn-RH), this study was undertaken to establish the signal transduction events interacting with Gn-RH receptor in a cell-free system prepared from human ovarian mucinous cystadenocarcinoma samples. A high affinity specific binding (Kd=8 × 10−9 M) of [3H] Gn-RH was demonstrated in two from two plasma membrane preparations. Gn-RH showed no effects on the rate of protein phosphorylation from [γ-32P] adenosine triphosphate in the plasma membrane preparations. On the other hand, incubation of plasma membrane isolated form [3H]inositol-labeled specimens with Gn-RH in the presence of guanosine thiotriphosphate resulted in the rapid production of inositol phosphates. The Gn-RH effects was concentration-dependent, and half-maximal activation occurred with 1–3 nm Gn-RH. The Gn-RH-stimulated membrane event was observed in all plasma membrane isolations tested, but not in those from uterine endometrial carcinoma of a given case. These results provide the first direct evidence that Gn-RH receptor is coupled to phosphoinositide hydrolysis but not to certain membrane protein phosphorylation/dephosphorylation in ovarian carcinoma plasma membrane. Though the functional role of this event in human ovarian cancer is still obscure, it might be part of a possible point of attack for therapeutic approaches using Gn-RH analogues in this malignancy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1525-1438.1993.03050311.x
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  • 6
    Electronic Resource
    Electronic Resource
    Diffusion of both Ga and Bi into InSb seeds during growth of InGaSbBi (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 858-864 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In1−xGaxSb1−yBiy (0〈x≤0.21, 0〈y≤0.005) quaternary bulk single crystals were grown on InSb seed crystals using a rotary Bridgman method. In order to investigate the quality of these crystals, various kinds of measurements were carried out, such as optical microscope, x-ray topograph, four-crystal x-ray diffractometry, electron-probe microanalysis, energy-dispersive spectroscopy, and secondary-ion-mass spectroscopy. All grown crystals were 10 mm in diameter and more than 10 mm in length. This indicates that the rotary Bridgman method was useful to grow quaternary bulk single crystals. Owing to segregation, the compositional ratio of Bi (y) increased and that of Ga (x) decreased as crystals grew. During growth of InGaSbBi, both Ga and Bi diffused into the InSb seed and there appeared domains of InBi. For comparison, InSb1−yBiy (0〈y≤0.05) and In1−xGaxSb (0〈x≤0.16) were grown on InSb. It turned out that Bi did not diffuse into InSb without Ga, but Ga diffused without Bi. The incorporation of Ga produced the excess In and as a result InBi domains were formed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357761
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  • 7
    Electronic Resource
    Electronic Resource
    Modular neural networks for identification of starches in manufacturing food products (1993)
    s.l. : American Chemical Society
    Biotechnology progress 9 (1993), S. 401-410 
    Details
    ISSN: 1520-6033
    Source: ACS Legacy Archives
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/bp00022a007
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  • 8
    Electronic Resource
    Electronic Resource
    Platelet superoxide dismutase in migraine and tension-type headache (1994)
    USA/Oxford, UK : American Association for the Study of Headache/Blackwell Science Ltd
    Cephalalgia 14 (1994), S. 0 
    Details
    ISSN: 1468-2982
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Superoxide dismutase (SOD) is a radical-scavenging enzyme. We determined Cu, Zn-SOD concentrations and activities in platelets from subjects with migraine and tension-type headaches. Thirty migraine without aura (MWoA) patients, 9 migraine with aura (MWA) patients, and 53 tension-type headache patients were selected for study. Thirty healthy volunteers composed the control group. Concentrations of platelet SOD were determined using enzyme-linked immunosorbent assay techniques. The activity of platelet SOD was determined by measuring reductivity of nitroblue tetrazolium. Low concentrations of platelet SOD were found in patients with MWA and MWoA. Platelet SOD activity decreased in MWA patients but not in patients with MWoA or tension-type headaches. These findings suggest vulnerability to oxidative stress in patients with migraine. It is suggested that low platelet SOD levels may play an important role in the etiology of migraine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1468-2982.1994.014003215.x
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  • 9
    Electronic Resource
    Electronic Resource
    Kilohertz-range flash x-ray generator utilizing a triode in conjunction with an extremely hot cathode (1991)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 62 (1991), S. 2115-2120 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The construction and the fundamental studies of a kilohertz-range flash x-ray generator having a triode in conjunction with an extremely hot cathode are described. This generator consisted of the following components: a constant-high voltage power supply, an energy storage condenser of 100 nF, a constant high-voltage power supply for regulating an initial grid voltage of −1.6 kV, a grid pulser, and an x-ray tube. The x-ray tube was of an enclosed-triode type and consisted of the following major parts: an anode rod made of copper, a plane anode tip (target) made of tungsten, a focusing electrode made of iron, a hot cathode (filament) made of tungsten, a grid made from tungsten wire, and a glass tube body. The energy storage condenser was charged from 50 to 70 kV, and the electric charges in the condenser were discharged repetitively to the x-ray tube by the grid electrode driven by the grid pulser. The temperature of the filament was about 2000 K, and the cathode current was primarily controlled by the grid voltage and its value was less than 1.2 A. The pulse widths were about 1 μs and the maximum repetitive frequency was about 2.0 kHz. The x-ray intensity was 19.7 nC/kg at 0.5 m per pulse with a peak grid voltage of 1.0 kV and a condenser charged voltage of 70 kV.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1142376
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  • 10
    Electronic Resource
    Electronic Resource
    Critical thickness anisotropy in highly carbon-doped p-type (100)GaAs layers grown by metalorganic molecular beam epitaxy (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 59 (1991), S. 60-62 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The formation of misfit dislocations at the (100)GaAs substrate interfaces of thick highly carbon-doped p-type GaAs layers grown by metalorganic molecular beam epitaxy, was investigated using x-ray diffraction and transmission electron microscopy. The misfit dislocation lines were observed to be all aligned along one of the 〈011〉 directions on the substrate and were identified as being ‘β' type. Enhanced migration of β dislocations in p-type GaAs coupled with heterogeneous dislocation loop formation at clusters of partially dissociated (CH3)3Ga molecules is proposed as a probable cause of the anisotropy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.105522
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