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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.
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
3.
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
4.
V. I. Dashkevich A. A. Bui V. A. Lisinetskii A. P. Shkadarevich R. V. Chulkov V. A. Orlovich 《Journal of Applied Spectroscopy》2007,74(3):390-395
We present the characteristics of an optical parametric oscillator based on a KTP crystal, pumped with noncritical phase matching
by a pulsed Ti3+:Al2O3 laser, tunable in the range 677–970 nm. Tunable generation of signal and idler waves is obtained in the ranges 1030–1390
nm and 2690–3050 nm respectively. The efficiency of conversion of the pump to the signal wave is ≈23%, which for pulses of
duration ≈8 nsec ensures an energy in the range 1.0–11.5 mJ. The width of the emission spectrum for the signal wave is within
the range 0.8–1.8 nm and is predominantly determined by the linewidth of the Ti3+:Al2O3 pump laser.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 3, pp. 351–356, May–June, 2007. 相似文献
5.
T. V. Panchenko 《Physics of the Solid State》1998,40(6):938-940
The spectral distribution of the uv-induced photoconductivity intensity and relaxation in Bi12SiO20 and Bi12GeO20 crystals both undoped and doped with Al, Ga, Cr, Cu, Mn, and V is investigated in the optical range 0.5–3.5 eV in the temperature
ranges 85–95 K and 285–295 K. It is shown that in the short-wavelength region 2.2–3.5 eV it is controlled by multicenter recombination
in which both “fast” and “slow” recombination participate.
Fiz. Tverd. Tela (St. Petersburg) 40, 1027–1029 (June 1998) 相似文献
6.
In this paper, we have studied the geometry of the five-dimensional black hole solutions in (a) Einstein–Yang–Mills–Gauss–Bonnet
theory and (b) Einstein–Maxwell–Gauss–Bonnet theory with a cosmological constant for spherically symmetric space time. Formulating
the Ruppeiner metric, we have examined the possible phase transition for both the metrics. It is found that depending on some
restrictions phase transition is possible for the black holes. Also for Λ = 0 in Einstein–Gauss–Bonnet black hole, the Ruppeiner
metric becomes flat and hence the black hole becomes a stable one. 相似文献
7.
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
8.
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
9.
Zhang Ye Hao Yuying Meng Weixin Xu Huixia Wang Hua Xu Bingshe 《Applied Physics A: Materials Science & Processing》2012,106(3):709-715
The electroplex between (2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazole) zinc [Zn(4-TfmBTZ)2] as an electron-acceptor and N,N′-diphenyl-N,N′-bis(1-naphthyl)-(1,1′-biphenyl)-4,4′-diamine (NPB) as an electron-donor was
characterized by bilayer, blend, and multilayer quantum-well (MQW) device, respectively. The blend composition and quantum-well
number are effective parameters for tuning electroluminescence color. White light with high color purity and color rendering
index (CRI) was observed from these devices based on Zn(4-TfmBTZ)2/NPB. Moreover, the blend and MQW devices all exhibit high operation stability, hence excellent color stability. For the device
with 5 mol% NPB in blend layer, its Commission International Del’Eclairage (CIE) coordinate region is x=0.28–0.31, y=0.33–0.35 and CRI is 83.3–91.2 at 5–9 V. For MQW structure device with NPB of 60 nm thickness, its CIE coordinate region
is x=0.29–0.32, y=0.31–0.34 and CRI=87.9–92.5 at 10–15 V. Such high color stability and purity and CRI, being close to ideal white light, are
of current important for white OLED. 相似文献
10.
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
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.
N. G. Galkin V. M. Astashynski E. A. Chusovitin K. N. Galkin T. A. Dergacheva A. M. Kuzmitski E. A. Kostyukevich 《Journal of Applied Spectroscopy》2009,76(6):840-846
Consecutive plasma-epitaxial synthesis on silicon wafers is used for the first time to fabricate monolithic nanoheterostructures
with embedded nanocrystals (NC) of chromium disilicide (Si–NC CrSi2–Si). It is found that, initially, nanoislands form on the surface and within a coating layer of silicon, followed by the
formation of small (10–15 nm) nanocrystals of semiconducting chromium disilicide (CrSi2) at a high occupation density ((2–3)⋅1011 cm–2). During formation of silicon-silicide-silicon heterostructures, CrSi2 nanocrystallites “float up” into the near surface area of the covering silicon layer. 相似文献
13.
This paper shows some improvements and new results of calibration of Chinese solar radio spectrometer by analyzing the daily
calibration data recorded in the period of 1997–2007. First, the calibration coefficient is fitted for three bands (1.0–2.0
GHz, 2.6–3.8 GHz, 5.2–7.6 GHz) of the spectrometer by using the moving-average method confined by the property of the daily
calibration data. By this calibration coefficient, the standard deviation of the calibration result was less than 10 sfu for
95% frequencies of 2.6–3.8 GHz band in 2003. This result is better than that calibrated with the constant coefficient. Second,
the calibration coefficient is found in good correlation with local air temperature for most frequencies of 2.6–3.8 GHz band.
Moreover, these results are helpful in the research of the quiet solar radio emission. 相似文献
14.
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
15.
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
16.
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
17.
MG30 is natural rubber grafted with 30% poly(methyl methacrylate). Gel polymer electrolytes containing MG30–LiCF3SO3–X (X = propylene carbonate, ethylene carbonate) are prepared by solution casting technique. The polymer–salt complexes were investigated using Fourier-transformed infrared. The ionic conductivity of the electrolytes are determined by the ac impedance studies over the temperature range of 303–383 K and is observed to obey the Vogel–Tamman–Fulcher (VTF) rule. The Li+ transference number obtained using the Bruce and Vincent method is <0.3. The Li/Li+ interface stability is established and the electrolytes were found to be able to withstand a voltage of more than 4.2 V. 相似文献
18.
The treatment of supersymmetry is known to cause difficulties in the C*–algebraic framework of relativistic quantum field theory; several no–go theorems indicate that super–derivations and super–KMS
functionals must be quite singular objects in a C*–algebraic setting. In order to clarify the situation, a simple supersymmetric chiral field theory of a free Fermi and Bose
field defined on is analyzed. It is shown that a meaningful C*–version of this model can be based on the tensor product of a CAR–algebra and a novel version of a CCR–algebra, the “resolvent
algebra”. The elements of this resolvent algebra serve as mollifiers for the super–derivation. Within this model, unbounded
(yet locally bounded) graded KMS–functionals are constructed and proven to be supersymmetric. From these KMS–functionals,
Chern characters are obtained by generalizing formulae of Kastler and of Jaffe, Lesniewski and Osterwalder. The characters
are used to define cyclic cocycles in the sense of Connes’ noncommutative geometry which are “locally entire”.
Dedicated to Daniel Kastler on the occasion of his 80th birthday 相似文献
19.
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
20.
S. Chotikaprakhan A. Haj-Daoud E. Neubauer J. Pelzl B. K. Bein R. Meckenstock 《The European physical journal. Special topics》2008,153(1):391-394
Copper-carbon interface systems with additional Mo bond
layers in the range of 25 nm to 200 nm have been analyzed with respect to
their effective thermal depth profiles before and after heat treatment using
modulated IR radiometry. Comparing the inverse calibrated modulated IR phase
lags before and after heat treatment, several effects can be identified: –
(1) The effusivity of the interface layer, which – due the contact
resistance between the two elements copper and carbon – is rather low
before heat treatment, increases considerably with heat treatment. – (2)
This effect is accompanied by an increase of the thermal diffusion time of
the interface layer, relying on the diffusion of Mo and Cu particles. – (3)
The sputter-deposited copper films, which before heat treatment can be
characterized as effective multi-layer structures, re-crystallize with heat
treatment and show modulated IR phases, which are characteristic for
thermally homogeneous thin films. – (4) The thermal diffusion times of the
Cu films decrease considerably with heat treatment due to increased thermal
diffusivities, and – (5) the thermal effusivities of the Cu films increase
with heat treatment. 相似文献