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1.
John Henry 《Physics in Perspective (PIP)》2007,9(4):468-501
I provide a tour of Edinburgh focusing on famous contributors to the history of physics and related sciences, using them as
a way to write about particular parts of Edinburgh. I proceed chronologically, from the seventeenth century to the Scottish
Enlightenment of the eighteenth century and on to the nineteenth and twentieth centuries. Among the notable individuals I
discuss are John Napier (1550–1617), James Gregory (1638–1675), George Sinclair (ca. 1625–1696), Colin Maclaurin (1698–1746), Joseph Black (1728–1799), James Hutton (1726–1797), John James Waterston (1811–1883),
William J. Macquorn Rankine (1820–1872), David Brewster (1781–1868), Peter Guthrie Tait (1831–1901), James Clerk Maxwell (1831–1879),
Charles Piazzi Smyth (1819–1900), Charles Glover Barkla (1877–1944), Max Born (1882–1970), Edward Victor Appleton (1892–1965),
Charles T.R. Wilson (1869–1959), and Peter Higgs (b. 1929). 相似文献
2.
Sean F. Johnston 《Physics in Perspective (PIP)》2006,8(4):451-465
I trace the history of the physical and applied sciences, and particularly physics, in Glasgow. Among the notable individuals
I discuss are Joseph Black (1728–1799), James Watt (1736–1819), William John Macquorn Rankine (1820–1872), William Thomson,
Lord Kelvin (1824–1907), John Kerr (1824–1907), Frederick Soddy (1877–1956), John Logie Baird (1888–1946), and Ian Donald
(1910–1987), as well as physics-related businesses.The locations, centering on the city center and University of Glasgow,
include sites both recognizable today and transformed from past usage, as well as museums and archives related to the history
and interpretation of physics. 相似文献
3.
V. A. Zinichev G. P. Komrakov N. A. Mityakov V. O. Rapoport 《Radiophysics and Quantum Electronics》2009,52(1):20-23
We present the results of the vertical ionosphere sounding at a frequency of 9.02 MHz using the “Sura” facility. Intense backscatter
signals from meteor trails were observed at altitudes 100–130 km. Increased background of the scattered signal, which was
about − 100 dB with respect to the mirror-reflected signal, was observed at altitudes of about 190–200 and 270–280 km. According
to the Doppler-shift measurements of the scattered-signal frequency, the wind velocity was more than 30 m/s at altitudes 100–130
and 270–280 km and was significantly smaller in the altitude range 190–200 km.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 52, No. 1, pp. 23–27, January 2009. 相似文献
4.
Dilip C. D. Nath Veena Sahajwalla 《Applied Physics A: Materials Science & Processing》2011,104(2):539-544
We produced carbon nanotubes (CNTs) by pyrolysis of a composite film of poly (vinyl alcohol) (PVA) with fly ash (FA) at 500°C
for 10 min under nitrogen. The composite films were prepared by a suspension of PVA and FA in deionized water and cast onto
glass petri dishes. The morphologies of the CNTs were observed in the images of scanning and transmission electron microscopy,
showing different types of structures, e.g. whiskers, branches, ropes and graphene sheets. The widths of the CNTs measured
varied in the range 18–80 nm. X-ray photoelectron spectroscopy analysis showed five types of carbon binding peaks, C–C/C–H
(∼77%), C–O–H (∼9%), –C–O–C (∼5%), C=O (∼5%) and –O–C=O (∼3%). From an image of a broken CNT, a mechanism was proposed for
the formation of CNTs. The CNTs grown on FA surfaces have potential for the fabrication of high-strength composite materials
with polymer and metal. 相似文献
5.
M. A. Algatti R. P. Mota R. Y. Honda M. E. Kayama K. G. Kostov R. S. Fernandes T. C.A.M. Azevedo N. C. Cruz 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(2):325-328
This paper deals with plasma polymerization processes of diethylene glycol dimethyl ether. Plasmas were produced at 150 mtorr
in the range of 10 W to 40 W of RF power. Films were grown on silicon and quartz substrates. Molecular structure of plasma
polymerized films and their optical properties were analyzed by Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible
spectroscopy. The IR spectra show C–H stretching at 3000–2900 cm-1, C=O stretching at 1730–1650 cm-1, C–H bending at 1440–1380 cm-1, C–O and C–O–C stretching at 1200–1000 cm-1. The concentrations of C–H, C–O and C–O–C were investigated for different values of RF power. It can be seen that the C–H
concentration increases from 0.55 to 1.0 au (arbitrary unit) with the increase of RF power from 10 to 40 W. The concentration
of C–O and C–O–C decreases from 1.0 to 0.5 au in the same range of RF power. The refraction index increased from 1.47 to 1.61
with the increase of RF power. The optical gap calculated from absorption coefficient decreased from 5.15 to 3.35 eV with
the increase of power. Due to its optical and hydrophilic characteristics these films can be applied, for instance, as glass
lens coatings for ophthalmic applications. 相似文献
6.
Zhiyuan Tian Yazhou Zhang Yanli Zhang Aidong Peng Ying Ma Yu Chen Wensheng Yang Yalin Tang Jiannian Yao 《Journal of nanoparticle research》2006,8(1):65-77
Nanostructures with well-defined shape and highly monodisperse size were fabricated from model stilbazolium-like dyes with specific molecular structural and conformational characteristics. With the help of absorption and fluorescence optical spectroscopy, the correlated spectroscopy (COSY) and two- dimensional nuclear Overhauser effect spectroscopy (2D NOESY) techniques, along with X-ray diffraction (XRD) measurement, distinctively different aggregation processes of the model molecules are demonstrated. For model dye molecule with linear donor–π system–acceptor (D–π–A) structure, strong D–A pair, and planar conformation, specific intermolecular interaction was identified and special crystal structures as well as spectral properties were observed. For model dye molecules bearing nonlinear D–π–A–π–D structure, weak D–A pair but actual amphiphilic characteristics, a special aggregation process was confirmed and a focused size distribution of the produced nanostructures was obtained. 相似文献
7.
Thermally excited emission spectrum of MgI, hitherto known only in flame and absorption sources, has been recorded in the
spectral region λλ3668–4220, using a high temperature vacuum graphite tube furnace. The bands were classified into three new
band systems in the wavelength regions λλ3905–4002, λλ3834–4079 and λλ3668–3888 along with a number of additional bands in
the previously known system A, λλ3955–4220. The constants for the various systems are as follows:
相似文献
8.
Summary Particle size distribution in the urban plume of the city of Valladolid was measured with a laser spectrometer during a one-month
sampling campaign carried out over the winter period. Experimental results of the number of particles covering the 0.10–0.12,
0.12–0.15, 0.15–0.20, 0.20–0.25, 0.25–0.35 and 0.35–0.45 μm ranges are presented. Using spectral analysis as a statistical
technique, two 12 h and 24 h significant peaks are obtained for each size range. In order to interpret the meaning of both
peaks, the hourly particle size, traffic and nitrogen oxide patterns are compared. The contribution of domestic heating, traffic
exhaust emissions and the strong influence of the gas-to-particle conversion processes mainly within the 0.10–0.15 μm range,
may be inferred. 相似文献
9.
A validated simple, rapid, and selective spectrofluorimetric method was developed for the determination of some antihistaminic
H1 receptor antagonist drugs namely ebastine (EBS), cetirizine dihydrochloride (CTZ), and fexofenadine hydrochloride (FXD).
The method is based on the reaction of the cited drugs with some Π acceptors namely p-chloranilic acid (CLA), tetracyanoethylene
(TCNE), and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) to give highly fluorescent derivatives. The fluorescence intensity—concentration plots were rectilinear
over the concentration ranges of 0.2–3.0, 0.2–2.5 and 0.15–2.0 μg/ml for EBS with CLA, DDQ, and TCNE respectively; 0.5–7.0,
0.5–6.0, and 0.2–4.0 μg/ml for CTZ with the previously mentioned reagents, and 0.2–3.5, 0.5–6.0, and 0.2–3.5 μg/ml for FXD.
The factors affecting the formation of the reaction products were carefully studied and optimized. The method was applied
for the determination of the studied drugs in their dosage forms. The results obtained were in good agreement with those obtained
by the comparison methods. Reactions Stoichiometries of the complexes formed between the studied drugs and Π acceptors were
defined by the Job’s method of the continuous variation and found in 1:1 in all cases. 相似文献
10.
The structures of zigzag-zigzag, armchair-zigzag, zigzag-chiral, armchair-armchair, armchair-chiral, and chiral-chiral pair
connections produced by single-walled carbon nanotubes 1.5–5.0 diameter with the use of the combined 5–7 and 4–8 topological
defects have been calculated by molecular mechanics methods. It has been established that the use of the combined 5–7 topological
defect makes it possible to produce connections between pairs of single-walled carbon nanotubes with any conductivities, chiralities,
and diameters, whereas the use of the combined 4–8 topological defect provides a means for forming connections between nanotubes
only with the same type of conductivity. The angles between the axes of nanotubes connected by the combined 5–7 and 4–8 topological
defects lie in the ranges 145°–180° and 112°–178°, respectively. It has been revealed that there are correlations between
structural parameters of the connections and the relative arrangement of the simple topological defects in the combined topological
defects. 相似文献
11.
A. Arranz 《Applied Physics A: Materials Science & Processing》2012,107(1):187-196
The 3 keV O2+\mathrm{O}_{2}^{+} reactive ion beam mixing of Cr/X interfaces (X=Al or Si) has been used to synthesize Cr-based mixed oxide thin films. The
kinetics of growth, composition, and electronic structure of those films has been studied using X-ray photoelectron spectroscopy,
Auger electron spectroscopy, ultraviolet photoelectron spectroscopy, and factor analysis. Initially, for low ion doses, Cr2O3 species are formed. Later, with increasing the ion dose, Cr2O3 species are first transformed into Cr3+–O–X species, and subsequently, those Cr3+–O–X species are transformed into Cr6+–O–X species. This sequential transformation, Cr2O3→Cr3+–O–X→Cr6+–O–X, is accompanied by a slight increase of the oxygen concentration and a decrease of the Cr/X ratio in the films formed
leading to the synthesis of custom designed Cr-based mixed oxides. The changes observed in the valence band and Auger parameters
further support the formation of Cr–X mixed oxide species. Angle resolved X-ray photoelectron spectroscopy shows that for
low ion doses, when only Cr2O3 and Cr3+–O–X species coexist, Cr3+–O–X species are located nearer the surface than Cr2O3 species, whereas for higher ion doses, when only Cr3+–O–X and Cr6+–O–X species coexist, the Cr6+–O–X species are those located nearer the surface. 相似文献
12.
F. Kokai K. Uchiyama T. Shimazu A. Koshio 《Applied Physics A: Materials Science & Processing》2010,101(3):497-502
Two types of one-dimensional (1D) nanostructures—amorphous silicon carbide (SiC) nanowires, 5–30 nm thick and 0.5–2 μm long,
and carbon nanotubes (CNTs) filled completely with crystalline SiC nanowires, 10–60 nm thick and 2–20 μm long—were synthesized
by the laser ablation of carbon-silicon targets in the presence of high-pressure Ar gas up to 0.9 MPa. All the CNTs checked
by transmission electron microscopy contained SiC, and no unfilled CNTs were produced. We discuss the growth of the two nanostructures
based on the formation of molten Si–C composite particles and their instabilities leading to the precipitation of Si and C. 相似文献
13.
V. P. Uryadov G. G. Vertogradov V. G. Vertogradov S. V. Kubatko A. A. Ponyatov Yu. N. Cherkashin I. V. Krasheninnikov V. A. Valov G. P. Komrakov A. V. Makarov D. V. Bredikhin 《Radiophysics and Quantum Electronics》2009,52(4):241-251
We describe the operation of an ionosonde/position finder with chirp modulation of the signal. The first results of measuring
the characteristics of short-wave radio signals scattered by artificial small-scale inhomogeneities, which were obtained by
means of an ionosonde/position finder on the IZMIRAN—“SURA”—Rostov-on-Don path are presented. It was found that under certain
ionospheric conditions, the angular and frequency selection of the scattered signals take place, in which case the signals
are observed simultaneously in several frequency intervals (mainly, in three, namely, 6–9.5 MHz, 10–12 MHz, and 15–18 MHz)
with different angles of incidence of radio waves in the vertical plane. In this case, the incidence angles were 20◦–35◦,
18◦–32◦, and 10◦–20◦ from the horizon for the first, second, and third frequency interval, respectively. Ionograms of oblique
sounding were modeled allowing for the scattering of radio waves by artificial small-scale inhomogeneities. It is shown that
at frequencies from 10 to 12 MHz, aspect conditions are fulfilled for the signals ducting along the high-angle beam (Pedersen
mode). At frequencies 15–18 MHz (higher than the maximum observable frequency of the forward signal on the path IZMIRAN—Rostov-on-Don),
aspect scattering conditions are fulfilled for the signals incident on a scattering area in the ascending part of the trajectory.
At low frequencies 6–9.5 MHz (below the maximum observed frequency of the forward signal on the IZMIRAN—Rostov-on-Don path),
the observable additional signals are caused by the scattering of radio waves by artificial inhomogeneities with subsequent
relfection of the scattered signal from the Earth on the “SURA”—Rostov-on-Don path.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 52, No. 4, pp. 267–278, April 2009. 相似文献
14.
The blend-based polymer electrolyte consisting of poly (vinyl chloride) (PVC) and poly (ethylene glycol) (PEG) as host polymers
and lithium perchlorate (LiClO4) as the complexing salt was studied. An attempt was made to investigate the effect of TiO2 concentration in the unplasticized PVC–PEG polymer electrolyte system. The XRD and FTIR studies confirm the formation of
a polymer–salt complex. The conductivity results indicate that the incorporation of ceramic filler up to a certain concentration
(15 wt.%) increases the ionic conductivity and upon further addition the conductivity decreases. The maximum ionic conductivity
0.012 × 10−4 S cm−1 is obtained for PVC–PEG–LiClO4–TiO2 (75–25–5–15) system. Thermal stability of the polymer electrolyte is ascertained from TG/DTA studies. 相似文献
15.
This research aims for an objective identification, tracking, and a statistical analysis of the Moving Magnetic Features (MMFs)
around sunspots using SOHO/MDI high-resolution magnetograms. To this end, we develop a computerized tracking program and study
the motion and magnetism of the outflows of MMFs around 26 sunspots. Our method locates 4–27 MMFs per hour, with higher counts
for large sunspots. We differentiate MMFs into type α that have a polarity opposite to the parent sunspots, and type β that share the sunspot’s polarity. These sunspots’ MMF subsets exhibit a wide range of central tendencies which have distinctive
correlations with the sunspots. In general, α-MMFs emerge farther from the sunspot, carry less flux, and move faster than β-MMFs. The typical α/β-MMFs emerge at 2.2–8.1/0.1–3.2 Mm outside the penumbra limb, with lifetimes of 1.1–3.1/1.3–2.0 h. They are 1.1–6.6/1.4–3.6
Mm2 in area and carry 1.4–12.5/4.8–11.4 ×1018 Mx of flux. They travel a distance of 2.7–5.9/2.8–3.6 Mm with the speed of 0.5–0.9/0.4–0.7 km/s. Compared to the α-MMFs produced by large sunspots, those of small spots are smaller. They emerge closer to sunspot, move farther, live longer,
and carry less flux. β-MMFs show much less correlation with the sunspots. The flux outflow carried by the MMFs ranges from 0.2 to 8.3 × 1019Mx· h−1 and does not show obvious correlation with the sunspots’ evolution. The frequency distributions of the MMFs’ distance traveled,
area, and flux are exponential. This suggests the existence of numerous small, weak, and short-timescale magnetic objects
which might contribute to the sunspot flux outflow. 相似文献
16.
Kuo-Sheng Kao Shang-Hao Chang Po-Tsung Hsieh Chih-Ming Wang Da-Long Cheng 《Applied Physics A: Materials Science & Processing》2009,96(2):529-533
Three-layered ZnO/Ag–Ti/ZnO structures were prepared using both the sol-gel technique and DC magnetron sputtering. This study
focuses on the electrical and optical properties of the ZnO/Ag–Ti/ZnO multilayers with various thicknesses of the Ag–Ti layer.
The ZnO thin film prepared by the sol–gel method was dried at 300°C for 3 minutes, and a fixed thickness of 20 nm was obtained.
The thickness of the Ag–Ti thin film was controlled by varying the sputtering time. The Ag–Ti layer substantially reduced
the electrical resistivity of the sol–gel-sprayed ZnO thin films. The sheet resistance of the Ag–Ti layer decreased dramatically
and then became steady beyond a sputtering time of 60 s. The sputtering time of Ag–Ti thin film deposition was determined
to be 60 s, taking into account the optical transmittance. Consequently, the transmittance of the ZnO/Ag–Ti/ZnO multilayer
films was 71% at 550 nm and 60% at 350 nm. The sheet resistance was 4.2 Ω/sq. 相似文献
17.
J.R. Liu M. Itoh T. Horikawa E. Taguchi H. Mori K. Machida 《Applied Physics A: Materials Science & Processing》2006,82(3):509-513
The electromagnetic wave absorption properties of resin compacts containing 40 vol. % composite powders of α-Fe/C(a), and
Fe3C/C(a) were characterized in a frequency range of 0.05–26.5 GHz, according to a conventional reflection/transmission technique.
The real part (εr
′) and the imaginary part (εr
′′) of relative permittivity were constantly low in the 2–14 GHz (εr
′= ∼12.4 and εr
′′= ∼0.6) for α-Fe/C(a) resin composites, and in the 1–26.5 GHz (εr
′= ∼9.6 and εr
′′= ∼0.8) for Fe3C/C(a) ones. The imaginary part (μr
′′) of relative permeability exhibited wide peaks in the 1–9 GHz range for α-Fe/C(a), and in the 2–26.5 GHz range for Fe3C/C(a) owing to their different magnetocrystalline anisotropy field values. Consequently, the resin compacts with 40 vol. %
α-Fe/C(a), and Fe3C/C(a) powders provided good electromagnetic wave absorption performances (reflection loss <-20 dB) in ranges of 4.3–8.2 GHz,
and 9–26.5 GHz over absorber thicknesses of 1.8–3.3 mm, and 1.0–2.4 mm, respectively.
PACS 76.50.+g; 61.46.+w; 75.50.Bb; 75.30.Gw; 75.20.En 相似文献
18.
Zn–Ni–TiO2 and Zn–TiO2 nanocomposites were prepared by galvanostatic cathodic square wave deposition. X-ray diffraction analysis and scanning electron
microscopy revealed that the occlusion of TiO2 nanoparticles (spherical shaped with diameter between 19.5 and 24.2 nm) promotes the formation of the γ-Ni5Zn21 phase, changes the preferred crystallographic orientation of Zn from (101) and (102) planes to (002), and decreases the particle
size of the metallic matrices. The stability of the nanocomposites immersed in near-neutral 0.05 mold m−3 Na2SO4 solution (pH 6.2) was investigated over 24 h. The initial open circuit potential for the Zn–Ni–TiO2 and Zn–TiO2 coatings were −1.32 and −1.51 V (vs. Hg/Hg2SO4), respectively, and changed to −1.10 and –1.49 V (vs. Hg/Hg2SO4) after 24 h of immersion. Data extracted from the steady state polarization curves demonstrated that the metal–TiO2 nanocomposites have, with respect to the metal coatings, a higher corrosion potential in the case of the Zn–Ni alloy composite;
a lower corrosion potential in the case of Zn-based nanocomposite albeit the predominant (002) crystallographic orientation;
and a lower initial corrosion resistance due to the smaller grain size and higher porosity in the Zn–Ni–TiO2 and Zn–TiO2 nanocomposites. Morphological and chemical analyses showed that a thicker passive layer is formed on the surface of the Zn–Ni–TiO2 and Zn–TiO2 deposits. After 24 h of immersion in the sulphate solution, the Zn–Ni–TiO2 coating has the highest corrosion stability due to the double-protective action created by the deposit’s surface enrichment
in Ni plus the higher amount of corrosion products. 相似文献
19.
V. M. Timokhin 《Russian Physics Journal》2009,52(2):152-156
Temperature and frequency spectra of tanδ, ε′, and ε″ of laser lithium iodate single crystals are investigated at temperatures
in the interval 77–450 K and frequencies in the range 5–108 Hz. An analysis of these spectra and the Cole–Cole diagrams demonstrates tunneling of charge carriers and existence of relaxation
oscillators of several types. The temperature interval for the tunnel effect is determined.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 39–42, February, 2009. 相似文献
20.
J. Kurpeta G. Lhersonneau J.C. Wang P. Dendooven A. Honkanen M. Huhta M. Oinonen H. Penttilä K. Peräjärvi J.R. Persson A. Płochocki J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》1998,2(3):241-243
Very neutron–rich fission products of the mass chain A=113 obtained from the IGISOL on–line mass separator have been investigated
by γγ coincidence techniques and γ-spectra multiscaling. Gamma–rays following β–decay of 113Tc have been observed for the first time and a new 0.5 s isomeric state has been found in 113Ru.
Received: 10 February 1998 相似文献