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61.
62.
M. Santos L. Díaz J. J. Camacho J. M. L. Poyato J. Pola T. Krenek 《Applied Physics A: Materials Science & Processing》2010,99(4):811-821
Laser-induced breakdown spectroscopy (LIBS) in germane (GeH4), initially at room temperature and pressures ranging from 2 to 10 kPa, was studied using a high-power transverse excitation
atmospheric (TEA) CO2 laser (λ=10.653 μm, τ
FWHM=64 ns and power densities ranging from 0.28 to 5.52 GW cm−2). The strong emission spectrum of the generated plasma is mainly due to electronic relaxation of excited Ge, H and ionic
fragments Ge+, Ge2+ and Ge3+. The weak emission is due to molecular bands of H2. Excitation temperatures of 8100±300 K and 23,500±2500 K were estimated by Ge atomic and Ge+ singly ionized lines, respectively. Electron number densities of the order of (0.7–6.2)×1017 cm−3 were deduced from the Stark broadening of several atomic Ge lines. The characteristics of the spectral emission intensities
from different species have been investigated as functions of the germane pressure and laser irradiance. Optical breakdown
threshold intensities in germane at 10.653 μm have been determined. The mechanism of initiation of the laser-induced plasma
in germane has been analyzed. 相似文献
63.
Vijai Singh Pallavi Somvanshi Gaurav Rathore D. Kapoor B. N. Mishra 《Applied biochemistry and biotechnology》2010,160(7):1985-1991
Aerolysin is a significant virulent toxin protein secreted by Aeromonas hydrophila; it produces deep wound infections and hemorrhagic septicemia. The complete aerolysin gene (1,482 bp) was amplified from
A. hydrophila. Furthermore, it was cloned and expressed into Escherichia coli BL21(DE3) codon plus RP cells using 0.5 mM IPTG for induction. The protein size was 54 kDa as estimated by SDS-PAGE, and
it was purified by Ni–NTA affinity chromatography. Anti-His antibodies were used to characterize the expressed aerolysin by
Western blotting and showed hemolytic activity with fish red blood cells. Aerolysin may be used as immunoassays for earlier
control of A. hydrophila and is also compatible for vaccination. 相似文献
64.
A recoil-proton spectrometer based on a monolithic silicon telescope coupled to a polyethylene converter was recently proposed and discussed in the literature. The device consists of a ΔE and an E-stage detector (about 2 μm and 500 μm in thickness, respectively) made out of a single silicon wafer and separated by a highly-doped layer acting as a common electrode.The detection system allowed continuous neutron spectra to be measured down to about 400 keV by discriminating against the contribution of low-LET radiation generated by photons from the distribution of the energy deposited in the E stage. This discrimination was carried out by selecting detected particles, event-by-event, with a ΔE ? E correlation. At neutron energies lower than 400 keV recoil-protons cannot reach the E stage owing to the thickness of the ΔE stage and therefore the discrimination failed.In order to further reduce the minimum detectable energy, an improved detection system, which also accounts for the energy deposited by recoil-protons in the ΔE stage, was studied and tested. The new set-up permits the total energy deposited in the telescope to be measured directly by collecting the charge carriers, generated in both stages, at the deep common electrode. The capability of reproducing continuous neutron spectra was also verified by irradiating the improved set-up with neutrons generated by protons striking a thick beryllium target at INFN – Laboratori Nazionali di Legnaro (Legnaro, Italy). The agreement of the unfolded spectra with literature data was satisfactory at energies higher than about 200 keV. 相似文献
65.
A. G. Pinkus Jason A. Kautz Pallavi Ahobila-Vajjula 《Journal of chemical crystallography》2003,33(3):181-186
The crystal structures of 2,6-dichlorobenzoic acid (1) and 3,5-dichlorobenzoic acid (2) were obtained by single-crystal X-ray diffraction. Crystallization of 1 occurred in the centrosymmetric triclinic space group P1 (No. 2) with a = 7.2678(9), b = 9.8543(8), and c = 11.8290(11) Å = 95.000(7), = 104.262(10), and = 102.128(8); and Z = 4. Crystallization of 2 occurred in the monoclinic centrosymmetric space group P21/n (No. 14) with a = 3.7812(3), b = 13.996(2), and c = 14.514(2) Å = 95.183(8); and Z = 4. Chlorine substituents of four dimeric molecules of 2 formed square channels, ca. 3.54 Å on a side, which run parallel to the crystallographic a axis. Monomers of 1 and 2 formed centrosymmetric dimers via near-linear hydrogen bonds. Details of the structures and spectroscopic results are presented and discussed. 相似文献
66.
Reactions of 6-(1′-phenylvinyl)-1,2,4-trioxanes 2-5, with FeCl2·4H2O, FeBr2, and a combination of hemin (bovine) and reduced glutathione (GSH) under various conditions have been studied. 相似文献
67.
The design and facile conversion of naturally occurring 4-hydroxyproline to all four diastereomers of thymine pyrrolidine PNA monomer, (2R,4S)-adenine, -guanine and -cytosine monomers and their incorporation into duplex forming PNA oligomers is reported. The interesting results of the hybridization studies with complementary DNA/RNA sequences in either parallel or antiparallel orientation reveal the stereochemistry-dependent DNA vs. RNA discriminations and parallel/antiparallel orientation selectivity. 相似文献
68.
Interaction between carbon disulfide and sulfur hexafluoride is excited by cw CO2 laser radiation and has been investigated for different ratios over a pressure range from 3.1 to 34.6 kPa. The reaction yields sulfur tetrafluoride, sulfur, carbon, thiocarbonyl fluoride, tetrafluoromethane and hexafluoroethane, the ratio of these latter products is dependent on the partial pressure of sulfur hexafluoride in the initial CS2-SF6 mixture. Interaction is considered to include both the SF6-sensitized decomposition of carbon disulfide and reaction between sulfur hexafluoride and carbon disulfide. 相似文献
69.
A systematic and novel quality by design–enabled, rapid, simple, and economic stability–indicating HPLC method for quantifying nirmatrelvir (NMT) was successfully developed and validated. An analytical target profile (ATP) was established, and critical analytical attributes (CAAs) were allocated to meet the ATP requirements. The method used chromatographic separation using a Purosphere column with a 4.6 mm inner diameter × 250 mm (2.5 μm). The analysis occurred at 50°C with a flow rate of 1.2 mL/min and detection at 220 nm. A 10 μL sample was injected, and the mobile phase consisted of two components: mobile phase A, containing 0.1% formic acid in water (20%), and mobile phase B, containing 0.1% formic acid in acetonitrile (80%). The diluent was prepared by mixing acetonitrile and water at a 90:10 v/v ratio. The retention time for the analyte was determined to be 2.78 min. Accuracy exceeded 99%, and the correlation coefficient was greater than 0.999. The validated HPLC method was characterized as precise, accurate, and robust. Significantly, NMT was found to be susceptible to alkaline, acidic, and peroxide conditions during forced degradation testing. The stability-indicating method developed effectively separated the degradation products formed during stress testing, underlining its effectiveness in stability testing and offering accuracy, reliability, and sensitivity in determining NMT. 相似文献
70.
Z. Bastl H. Bürger R. Fajgar D. Pokorn J. Pola M. Senzlober J. ubrt M. Urbanov 《应用有机金属化学》1996,10(2):83-99
CO2 laser-induced infrared multiphoton decomposition (IRMPD) and SF6 photosensitized decomposition (LPD) of silacyclobutane (SCB) and 1,3-disilacyclobutane (DSCB) in the gas phase results in the very efficient deposition of Si/C/H and SiC materials, and it is inferred that the process is dominated by formation of transient silene; silene rearrangement to methylsilylene; silene and methylsilylene dehydrogenation; and polymerization of SiCHn (n < 4) species. The deposits are sensitive to oxygen. Decomposition and SiC formation are favoured with IRMPD experiments conducted with high-energy fluxes. The laser technique is promising for low-temperature chemical vapour deposition of amorphous SiC. 相似文献