共查询到20条相似文献,搜索用时 16 毫秒
1.
L. V. Deputatova V. I. Vladimirov V. S. Filinov V. E. Fortov A. P. Budnik P. P. Dyachenko V. A. Rykov K. V. Rykov 《Plasma Physics Reports》2010,36(13):1167-1172
The results of investigations of dust grain behavior in plasma formed by a proton beam in inert gases (He, Ar, Kr) are demonstrated.
Stable ordered dust structures, namely “a plasma-dust crystal” formed of dust grains 1.0, 3.0, and 4.8 μm in diameter are
obtained in the proton beam range for the first time. The mathematical model which allows for numerical simulation of crystal
formation from dust grains formed by proton beam plasma is developed. 相似文献
2.
The modified Gardner equation (MGE), showing the existence of compressive and rarefactive dust-ion-acoustic (DIA) solitons
in a nonplanar dusty plasma (containing inertial ions, Boltzmann electrons, and negatively charged stationary dust) beyond
the KdV Korteweg-de Vries (KdV) limit, is derived and numerically solved. The basic features of the compressive and rarefactive
cylindrical and spherical DIA solitons, which are found to exist beyond the KdV limit, i.e., exist for μ ∼ 2/3 (where μ =
Z
n
n
d0/n
i0, z
d
is the number of electrons residing onto the dust grain surface, n
d0(n
i0) is the dust (ion) number density at equilibrium, and μ ∼ 2/3 means that μ is not equal to 2/3, but it is around 2/3) are
identified. These solitons (which can be referred to as DIA Gardner solitons (DIA-GSs)) are completely different from the
KdV solitons because μ = 2/3 corresponds to the vanishing of the nonlinear coefficient of the KdV equation, and μ ∼ 2/3 corresponds
to extremely large amplitude KdV solitons for which the validity of the reductive perturbation method breaks down. It is also
shown that the properties of the nonplanar (cylindrical and spherical) DIA-GSs are significantly different from those of the
one dimensional planar ones. 相似文献
3.
Species and material considerations in the formation and development of microalgal biofilms 总被引:2,自引:0,他引:2
The development of microalgal biofilms has received very limited study despite its relevance in the design of photobioreactors
where film growth may be advantageous for biomass separation or disadvantageous in fouling surfaces. Here, the effects of
species selection, species control, and substrate properties on biofilms of Scenedesmus obliquus and Chlorella vulgaris were investigated. Experiments were conducted in batch culture and in continuous culture modes in a flow cell. Cell growth
was monitored using confocal laser scanning microscopy and gravimetrically. Species selection and species control had significant
effects on biofilm development. On non-sterile wastewater, C. vulgaris shifted from primarily planktonic (23.7% attachment) to primarily sessile (79.8% attachment) growth. The biofilms that developed
in non-sterile conditions were thicker (52 ± 19 μm) than those grown in sterile conditions (7 ± 6 μm). By contrast, S. obliquus attained similar thicknesses (54 ± 31 and 53 ± 38 μm) in both sterile and non-sterile conditions. Neither species was able
to dominate a non-sterile biofilm. The effect of substrate surface properties was minimal. Both species grew films of similar
thickness (∼30 μm for S. obliquus, <10 μm for C. vulgaris) on materials ranging from hydrophilic (glass) to hydrophobic (polytetrafluoroethylene). Surface roughness created by micropatterning
the surface with 10 μm grooves did not translate into long-term increases in biofilm thickness. The results indicate that
species selection and control are more important than surface properties in the development of microalgal biofilms. 相似文献
4.
The relationship between the particle size of an inert silica dust, its up-take from different surfaces and the grooming behaviour
of males, gravid females, and fifth and sixth instar nymphs of the German cockroachBlattella germanica (Dictyoptera: Blattellidae) (L.) was investigated. The normal grooming behaviour of gravid females, nymphs and males differed
according to sex and age. The gravid females and nymphs exhibited greater grooming activity than the males, especially of
the antennae and the legs. Gravid females, nymphs, and adult males exhibited increased grooming activity after exposure to
dust in the size range 0.5–63 μm, but there was no significant difference in grooming behaviour from the control when cockroaches
were exposed to dust sizes greater than 70 μm. Antennal grooming by males was greater than leg grooming when exposed to all
dust sizes, except size particles ranging 4.5–7.5 μm. A dust pick-up experiment indicated that the average amount of dust
transferred toB. germanica is affected by particle size, the porosity of the treated surface, and the sex and age of the cockroaches. Gravid females
picked up greater amounts of dust than fifth and sixth instar nymphs, which in turn picked up more dust than males. Silica
dust particles (0.5–7.5 μm) were picked up more effectively than larger particle sizes, by all three categories, males, females
and fifth and sixth instar nymphs of cockroach on all three test surfaces plastic, ceramic and unpainted plywood. Plywood
was the least effective surface for transfer of dust, of all sizes, to males, females and nymphs. 相似文献
5.
Resveratrol (RES), a component of red wine, possesses anti-inflammatory properties. The studies described in the present work
were aimed at evaluating the potential for RES and related stilbene analogs (piceatannol, PIC; pterostilbene, TPS; trans-stilbene, TS; and trans-stilbene oxide, TSO) to exhibit toxicity towards RAW 264.7 mouse macrophages. The effect of TS, TSO, RES and TPS on RAW 264.7
macrophage viability was determined by two standard methods: (a) the MTT assay and (b) the trypan blue dye exclusion test.
Whereas macrophages were more sensitive to PIC (LC50 trypan ∼ 1.3 μM) and to TPS (LC50 trypan ∼ 4.0 μM and LC50 MTT ∼ 8.3 μM) than to RES (LC50 trypan ∼ 8.9 μM and LC50 MTT ∼ 29.0 μM), they were relatively resistant to TSO (LC50 trypan ∼ 61.0 μM and LC50 MTT > 100 μM) and to TS (LC50 trypan ≥ 5.0 μM and LC50 MTT ≥ 5.0 μM). The ability of selected stilbenes (RES, TPS and PIC) to exhibit growth inhibitory effects was also examined. Although
RES and TPS were observed to inhibit cell proliferation in macrophages (IC50 ≤ 25 μM), these cells were resistant to growth inhibition by PIC (IC50 ≥ 50 μM). The data obtained in the present analysis demonstrate that substituted stilbene compounds such as RES have the
capacity to exhibit cytotoxic and anti-proliferative activities in macrophages. 相似文献
6.
H. Schmitz M. Mürtz H. Bleckmann 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2000,186(6):543-549
The pit organs of the beetle Melanophilaacuminata were stimulated with monochromatic infrared radiation using a continuous wave CO overtone infrared laser. Best sensitivity
was in the wavelength range 2.8–3.5 μm. In this range a stimulus intensity of 14.7 mW cm−2 was sufficient to generate single action potentials. At a wavelength of 5 μm receptor performance significantly decreased.
An increase in stimulus intensity caused a decrease in response latency and an increase in the number of action potentials
elicited. At a given wavelength (3.4 μm) the dynamic amplitude range of action potential responses covered 12 dB. At high
stimulus intensities (94.2 mW cm−2) a stimulus duration of 4 ms was sufficient to generate one to two action potentials and a stimulus duration of 60 ms already
caused response saturation (with up to nine action potentials). In a repetitive stimulus regime distinct receptor potentials
were visible up to a frequency of 600 Hz.
Accepted: 18 March 2000 相似文献
7.
Lydie M. Dupont Hermann Behling Susanne Jahns Fabienne Marret Jung-Hyun Kim 《Vegetation History and Archaeobotany》2007,16(2-3):87-100
The distribution of pollen in marine sediments is used to record vegetation changes over the past 30,000 years on the adjacent
continent. A transect of marine pollen sequences from the mouth of the river Congo (∼5°S) to Walvis Bay and Lüderitz (∼25°S)
shows vegetation changes in Congo, Angola and Namibia from the last glacial period into the Holocene. The comparison of pollen
records from different latitudes provides information about the latitudinal shift of open forest and savannahs (Poaceae pollen),
the extension of lowland forest (rain forest pollen) and Afromontane forest (Podocarpus pollen), and the position of the desert fringe (pollen of Caryophyllaceae, Chenopodiaceae and Amaranthaceae). High Cyperaceae
pollen percentages in sediments from the last glacial period off the mouth of the river Congo suggest the presence of open
swamps rather than savannah vegetation in the Congo Basin. Pollen from Restionaceae in combination with Stoebe-type pollen (probably from Elytropappus) indicates a possible northwards extension of winter rain vegetation during the last glacial period. The record of Rhizophora (mangrove) pollen is linked to erosion of the continental shelf and sea-level rise. Pollen influx is highest off river mouths
(10–2000 grains year−1 cm−2), close to the coast (300–6000 grains year−1 cm−2), but is an order of magnitude lower at sites situated far from the continent (<10 grains year−1 cm−2). 相似文献
8.
A comparative analysis of photosynthetic characteristics of hulless barley at two altitudes on the Tibetan Plateau 总被引:1,自引:0,他引:1
To determine the photosynthetic characteristics of C3 plants and their sensitivity to CO2 at different altitudes on the Tibetan Plateau, hulless barley (Hordeum vulgare L. ssp. vulgare) was grown at altitudes of 4,333 m and 3,688 m. Using gas-exchange measurements, photosynthetic parameters were simulated,
including the maximum net photosynthesis (P
max) and the apparent quantum efficiency (α). Plants growing at higher altitude had higher net photosynthetic rates (P
N), photosynthesis parameters (P
max and α) and sensitivities to CO2 enhancement than plants growing at lower altitude on the Tibetan Plateau. The enhancements of P
N, P
max, and α for plants growing at higher altitude, corresponding with 10 μmol(CO2) mol−1 increments, were approximately 0.20∼0.45%, 0.05∼0.20% and 0.12∼0.36% greater, respectively, than for plants growing at lower
altitude, respectively, where CO2 levels rose from 10 to 170 μmol(CO2) mol−1. Therefore, on the Tibetan Plateau, the changes in the photosynthetic capacities and the photosynthetic sensitivities to
CO2 observed in the C3 plants grown above 3,688 m are likely to increase with altitude despite the decreasing CO2 partial pressure. 相似文献
9.
Chiba seed (Psoralea corylifolia L.) oil, which contains bioactive components such as bakuchiol, psoralen, and isosporalen, is recognized for its high medicinal
value and is widely used in Chinese and Indian Ayurvedic medicinal systems. Several earlier studies have proved the antibacterial
and antioxidant properties of the key components in the seed oil. In view of the importance of the bioactive components in
the global market, this study was carried out to separate the key components by supercritical carbon dioxide extraction and
further enrichment by the molecular distillation technique. The effects of the process variables such as pressure (400∼2,000
μm), temperature (140∼200°C), and wiper speed (120∼200 rpm) were studied based on response surface methodology. The predicted
model was maximized for the bakuchiol content in the distillate. And a predicted maximum of 72% bakuchiol content was confirmed
by the experiment under the optimized process conditions. 相似文献
10.
Michail I. Gladyshev Nadezhda N. Sushchik Olga P. Dubovskaya Olesia N. Makhutova Galina S. Kalachova 《Aquatic Ecology》2008,42(4):617-627
Specific growth rates (based on biomass increment in unit time) of Daphnia fed natural reservoir seston from a eutrophic Siberian reservoir were studied during four vegetation seasons in a laboratory
flow-through system. Concentrations of particulate C, N, and P in reservoir seston <115 μm were comparatively high, 1.9, 0.2,
and 0.05 mg l−1, respectively; maximum C:P ratio was 259 mol:mol. According to conventional thresholds, concentrations of elements and their
stoichiometry did not limit the growth rate of Daphnia. Eicosapentaenoic acid (EPA) in seston significantly effected the growth rates at concentrations up to ∼13 μg l−1 (regression ANOVAR F-test value was 7.91), but not above this concentration. Thus, we consider this concentration of EPA in seston <115 μm to
be the limiting concentration of EPA for the growth of Daphnia (longispina group), i.e., below this concentration EPA was the best single predictor of the growth of Daphnia. 相似文献
11.
Abundance and Production of Riparian Trees in the Lowland Floodplain of the Queets River, Washington 总被引:1,自引:1,他引:0
Riparian zones associated with alluvial rivers are spatially dynamic, forming distinct vegetative mosaics that exhibit sharp
contrasts in structure and processes related to the underlying biophysical template. The productivity of riparian plants,
especially trees, influences streamside community characteristics as well as the forms and fluxes of organic matter to adjacent
streams – thereby strongly impacting patterns of channel morphology, water flow, sedimentation, and habitat in rivers. As
part of a comprehensive investigation of riparian dynamics in coastal rain forest rivers of the Pacific Northwest (USA), we
examined riparian tree abundance (density, basal area, and biomass) and rates of production (basal area growth [BAI] and bole
wood biomass increase [P]) of seven common species – red alder (Alnus rubra), Sitka spruce (Picea sitchensis), bigleaf maple (Acer macrophyllum), western hemlock (Tsuga heterophylla), black cottonwood (Populus trichocarpa), vine maple (Acer circinatum) and willow (Salix spp.) – in the lowland floodplain of the Queets River (Olympic National Park), Washington. Measurements were made annually
for three years (1999 – 2001) in 16 permanent plots on three biophysical templates that formed a toposequence – active floodplain,
young terrace and mature terrace. Stem density was highest in the active floodplain (∼27,000 stems/ ha), decreasing in the
young terrace (∼2,700 stems /ha) and the mature terrace (∼500 stems/ha). Basal area and total stem biomass were lowest in
the active floodplain (∼16 m2/ha and ∼18 Mg dry weight/ha, respectively) and higher on the young terrace (∼32 m2/ha and ∼134
Mg dry weight/ha) and on the mature terrace (∼69 m2/ha and ∼540 Mg dry weight /ha). Total plot-scale BAI was not significantly
different among the physical templates with mean values ranging from approximately 1.4 (low terrace) to approximately 2.8
m2/ha/y (active floodplain). In contrast, P was significantly higher on the mature terrace (10.3 Mg/ha) than the active floodplain
(3.2 Mg/ha) but there was no significant difference between young terrace (6.5 Mg/ha) and mature terrace. For the entire Queets
River floodplain (57 km2 over 77 km of river length), the mature terrace contributed 81% of the total annual production (28,764 Mg) whereas the active
floodplain and young terrace accounted only for 5 and 14%, respectively. Overall, we show that riparian trees grow quickly
in this coastal Pacific Northwest system and that the older riparian forests on mature terraces are the main contributors
to stem production at the plot and floodplain scales for at least 350 years after stand initiation. This suggests that, in
combination with the rapid lateral migrations of many alluvial rivers, the older riparian forests on those terraces are important
and sustained sources of organic matter (especially large woody debris, LWD) that, over decades to centuries, shape the character
of coastal rivers in the Pacific Northwest. 相似文献
12.
Five brands of antidiabetic herbal formulations as tablets, Diabetex, Divya Madhu Nashini, Jambrushila, Diabeticin, and Madhumeh Nashini, from different pharmacies were analyzed for six minor (Na, K, Ca, Cl, Mg, and P) and 20 trace (As, Ba, Br, Ce, Co, Cr, Cs,
Cu, Fe, Hg, La, Mn, Rb, Sb, Sc, Se, Sm, Th, V, and Zn) elements by thermal neutron irradiation followed by high-resolution
gamma ray spectrometry. Further Ni, Cd, and Pb were determined by atomic absorption spectrophotometry. Most elements vary
in a narrow range by a factor of 2–4 while a few others vary in a wide range, e.g., Na (0.05–0.67 mg/g), Mn (26.7–250 μg/g),
and V (0.26–2.50 μg/g). All the five brands contain K, Cl, Mg, P, and Ca as minor constituents along with mean trace amounts
of Cr (2.11 ± 0.67 μg/g), Cu (15.7 ± 7.11 μg/g), Fe (459 ± 171 μg/g), Mn (143 ± 23 μg/g), Se (238 ± 112 ng/g), and V (0.99 ± 0.93 μg/g).
Jambrushila is enriched in Na, Ca, Mg, Cl, Fe, Cu, Se, and Zn, essential nutrients responsible for curing diabetes. Dietary intake of
Mn, Fe, and Cu are greater than 10% of the recommended dietary allowance, whereas that for Zn and Se is less than 2%. Mean
contents of toxic elements (As, Cd, Hg, and Pb) were found below permissible limits except in Jambrushila. Cr and Zn were inversely correlated with r = −0.81, whereas Rb and Cs exhibit linear correlation (r = 0.93) in five brands. C, H, N analysis showed C ∼ 55%, H ∼ 12%, and N ∼ 2% with a total of ∼70% organic matter. However,
thermal decomposition studies at 700°C suggest less than 5% nonvolatile metal oxides. Herbal formulations contain minor and
trace elements in bioavailable forms that favorably influence glucose tolerance and possibly increase the body’s ability to
ameliorate development of diabetes. 相似文献
13.
Zhang W Hywood Potter KJ Plantz BA Schlegel VL Smith LA Meagher MM 《Journal of industrial microbiology & biotechnology》2003,30(4):210-215
Fed-batch fermentation of a methanol utilization plus (Mut+) Pichia pastoris strain typically has a growth phase followed by a production phase (induction phase). In the growth phase glycerol is usually
used as carbon for cell growth while in the production phase methanol serves as both inducer and carbon source for recombinant
protein expression. Some researchers employed a mixed glycerol-methanol feeding strategy during the induction phase to improve
production, but growth kinetics on glycerol and methanol and the interaction between them were not reported. The objective
of this paper is to optimize the mixed feeding strategy based on growth kinetic studies using a Mut+
Pichia strain, which expresses the heavy-chain fragment C of botulinum neurotoxin serotype C [BoNT/C(Hc)] intracellularly, as a
model system. Growth models on glycerol and methanol that describe the relationship between specific growth rate (μ) and specific glycerol/methanol consumption rate (ν
gly, ν
MeOH) were established. A mixed feeding strategy with desired μ
gly/μ
MeOH =1, 2, 3, 4 (desired μ
MeOH set at 0.015 h−1) was employed to study growth interactions and their effect on production. The results show that the optimal desired μ
gly/μ
MeOH is around 2 for obtaining the highest BoNT/C(Hc) protein content in cells: about 3 mg/g wet cells.
Electronic Publication 相似文献
14.
Prostaglandin-synthetase activity has been measured in the microsomal fraction of developing toad (Bufo melanostictus) ovary using arachidonic acid as the substrate. Indomethacin (0.74μM) and aspirin (0.35μM) inhibit this activity. The activity is maximum in immature ovary and its level gradually decreases with maturity of the
organ till the breeding season arrives, when it rises again. Time course study shows that the activityin vitro becomes steady after 3 min of incubation in all the cases, except the immature ones in which it sharply declines. Soluble
supernatant was found to contain some inhibitory factor(s), which is partially inactivated by heating at 100°C for 5 min (∼
43%). Intraperitoneal injection of equine luteinizing hormone stimulates this enzyme activity in the mature ovary during non-breeding
season. This suggests that similar to mammalians prostaglandin-synthetase, the toad ovary enzyme is also regulated by luteinizing
hormone 相似文献
15.
The purpose of this research was to create a calibration model based on near-infrared (NIR) spectroscopy data obtained during
a small-scale coating process to predict in-line the coating layer thickness of tablets coated in a side-vented drum coater.
The developed setup for the small-scale coating process consisted of a rotating plate with 20 tablets molds that pass a spraying
unit, a heating unit, and an in-line NIR spectroscopy probe during one rotation. High-density polyethylene (HDPE) was compressed
to flat-faced tablets, and these were coated with a sustained release coating suspension containing Kollicoat IR and Kollicoat
SR 30D. The film thickness of these tablets was determined for each tablet individually with a digital micrometer. A calibration
model of predicted film thickness versus real-film thickness using PLS regression was developed. This model was tested against in-line NIR data obtained from a coating
drum process, in which biconvex HDPE tablets were film-coated with the same film-coating suspension. The model predicted a
final coating thickness of 240 μm, while the measured average thickness (n = 100 tablets) was 210 μm. Taking into account the use of a different setup and differently shaped tablets, it was possible
to predict the coating thickness with accuracy comparable to the one of the digital micrometer. Thus, the small-scale rotating
plate system was found to be an efficient means of preparing calibration model for a tablet-coating drum process. 相似文献
16.
Dr. R. Pamela Reid Dr. Ian G. Macintyre Dr. Kathleen M. Browne Dr. Robert S. Steneck Dr. Timothy Miller 《Facies》1995,33(1):1-17
Summary Modern stromatolites in open marine environments, unknown until recently, are common throughout the Exuma Cays, Bahamas. They
occur in three distinct settings: subtidal tidal passes, subtidal sandy embayments and intertidal beaches. These stromatolites
have a relief of up to 2.5 m and occur in water depths ranging from intertidal to 10 m. Surfaces near the sediment-water interface
are typically colonized by cyanobacterial mats, whereas high relief surfaces are commonly colonized by algal turf and other
macroalgae such asBatophora, Acetabularia, andSargassum. The internal structure of the stromatolites is characterized by millimeter-scale lamination defined by differential lithification
of agglutinated sediment. In thin section, the lithified laminae appear as micritic horizons with distinct microstructures:
they consist of thin micritic crusts (20–40 μm thick) overlying layers of micritized sediment grains (200–1000 μm thick);
the micritized grains are cemented at point-contacts and are trucated along a surface of intense microboring. The Exuma stromatolites
are built by cyanobacterial-dominated communities. These laminated prokaryotic structures grade to unlayered thrombolites
built by eukaryotic algae. The variety of sites, settings and shapes of stromatolites in the Exuma Cays present excellent
opportunities for future studies of stromatolite morphogenesis. 相似文献
17.
Hee-Kyoung Jung Joo-Heon Hong Seung-Chun Park Byung-Kwon Park Doo-Hyun Nam Sang-Dal Kim 《Biotechnology and Bioprocess Engineering》2007,12(6):713-719
This study was conducted to develop a bacterial glucan as an animal feed additive. A novel glucan-producing bacterium.Paenibacillus polymyxa JB115, was isolated from Korean soil. The glucan, JB115-BG, produced byP. polymyxa JB115, was confirmed by TLC to be composed of glucose only. By examining FT-IR,1H NMR, and13C NMR spectra, it was proven that JB115-BG has a β-(1→3)- and β-(1→6)-linked glucan structure. The particle size of JB115-BG
was distributed in the range of 4–800 μm, with a mean value of 149.1 μm, and its molecular distribution ranged from 6.9∼3,103.7
kDa. It was also observed that 80% of the purified JB115-BG had a molecular distribution above 100 kDa. The obtained results
suggest that the glucan JB115-BG can be used as an animal feed additive for the purpose of enhancing immunity. 相似文献
18.
Dong-Hee Lee 《Journal of Plant Biology》1998,41(2):86-92
An anthocyanin-free tomato plant, H957, and its parental wild type, H883, were hydroponically grown to test for tolerance
to a low phosphorus (P) in H957. The tolerance was evaluated by comparing growth and metabolism of H957 vs. H883 at different
P concentrations ranging 25–400 μM. Fresh weights were measured weekly. Dry weight, mineral contents, photosynthetic rate,
and P utilization ratios of the plants were measured after five weeks of growth in the hydroponic culture. Although the growth
of both varieties was severely impaired at 25 μM P, H957 showed a greater fresh weight and dry weight at 50–400 μM P. H957
showed a higher net photosynthetic rate on older leaves while both varieties showed similar photosynthetic rate on young leaves.
H957 tissue contains an overall lower P concentration in its tissue than H883. These observations together indicate that the
anthocyaninless mutant H957 tolerate to lower P concentration. It does so by utilizing internal P with better efficiency rather
than by absorbing external P better. 相似文献
19.
Gurusamy Balakrishnan Mohammed Ibrahim Piotr J. Mak Jessica Hata James R. Kincaid Thomas G. Spiro 《Journal of biological inorganic chemistry》2009,14(5):741-750
Time-resolved resonance Raman (RR) spectra are reported for hemoglobin (Hb) tetramers, in which the α and β chains are selectively
substituted with mesoheme. The Soret absorption band shift in mesoheme relative to protoheme permits chain-selective recording
of heme RR spectra. The evolution of these spectra following HbCO photolysis shows that the geminate recombination rates and
the yields are the same for the two chains, consistent with recent results on 15N-heme isotopomer hybrids. The spectra also reveal systematic shifts in the deoxyheme ν
4 and ν
Fe–His RR bands, which are anticorrelated. These shifts are resolved for the successive intermediates in the protein structure,
which have previously been determined from time-resolved UV RR spectra. Both chains show Fe–His bond compression in the immediate
photoproduct, which relaxes during the formation of the first intermediate, Rdeoxy (0.07 μs), in which the proximal F-helix is proposed to move away from the heme. Subsequently, the Fe–His bond weakens, more
so for the α chains than for the β chains. The weakening is gradual for the β chains, but is abrupt for the α chains, coinciding
with completion of the R–T quaternary transition, at 20 μs. Since the transition from fast- to slow-rebinding Hb also occurs
at 20 μs, the drop in the α chain ν
Fe–His supports the localization of ligation restraint to tension in the Fe–His bond, at least in the α chains. The mechanism is
more complex in the β chains. 相似文献
20.
The epitaxial growth of a diamond single-crystal film in a torch microwave discharge excited by a magnetron of a domestic
microwave oven with the power of ≤1 kW in an argon-hydrogen-methane mixture with a high concentration of methane (up to 25%
with respect to hydrogen) at atmospheric pressure on a sub-strate of a synthetic diamond single crystal (HPHP) with the orientation
(100) and 4 × 4 mm in size is obtained. A discharge with the torch diameter of ∼2 mm and the concentration of the microwave
power absorbed in the torch volume of >103 W/cm3 is shown to be effective for epitaxial enlargement of a single crystal of synthetic diamond. The structure of the deposited
film with the thickness up to 10 μm with high-quality morphology is investigated with an optical microscope as well as using
the methods of the Raman scattering and scanning electron microscopy. 相似文献