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1.
Removal of a wide range of trace organic contaminants from water to concentrations below USEPA Maximum Contaminant Levels (MCL) remains an important goal for the water industry. Design of advanced carbon based adsorption systems represents a unique approach to solving these problems. A number of successful examples are cited in this paper and are briefly summarized in the following section.
- Removal of foulants such as humic acid using nanoparticle carbon blacks and chemically activated nanoporous fibers;
- Removal of trace organic contaminants such as benzene, toluene, ethylbenzene and p-xylene (BTEX) to levels below USEPA MCL using nanoporous carbon fibers;
- Removal of trace chemical warfare simulants such as diisopropylmethyl phosponate and chloroethylethylsulfide using enlarged nanoporous carbon fibers;
- Removal of trace chlorinated solvents such as trichloroethylene (TCE) and chloroform using tailored nanoporous carbon fibers;
- Removal of the trace herbicide, atrazine, to below USEPA MCL level using nanoporous chemically activated fibers.
2.
J. Halbritter 《Applied Physics A: Materials Science & Processing》1986,39(1):49-57
Broad-area electrodes show electron emission already at electric field strengthsF≈107 V/m. This enhanced field emission (EFE) occurs only for contaminated surfaces. EFE is accompanied by photon emission and gas desorption yielding finally discharges. EFE is caused by dust and contaminants initiating the following effects: an electron is stochastically emitted in a trigger zone the electron gains energyΔE?eΔxF * which excites electronic states which relax by the emission of electrons, photons, and atoms where the positive charges left behind enhanceF *=βF (β?1) initiating so an electron avalanche, i.e., a high conductivity channel. Because of charge migration and neutralization, this avalanche has a life time. This pulsating EFE is accompanied by light emission and gas desorption yielding finally a gas cloud and a discharge. The pulsating, self-sustained EFE has the same root as: the enhanced secondary emission found first by Malter the conductivity switching exhibited by thin (≈ 1 μm) layers of semiconductors or insulators the normal cathode fall and the firing-wave instability in neurodynamics. 相似文献
3.
Conclusions
- The temperature profile of an absorbing film for a given microwave power flux distribution has been considered.
- The conditions under which agreement is found between the temperature relief and the flux distribution has been clarified.
- An experimental investigation has been carried out of the temperature profile in a matched film for the TE10 mode.
- The possibility of using a semiconductor thermal probe to investigate the microwave power flux distribution has been demonstrated.
4.
E. Mourre 《Communications in Mathematical Physics》1981,78(3):391-408
We give a sufficient condition for a self-adjoint operator to have the following properties in a neighborhood of a pointE of its spectrum:
- its point spectrum is finite;
- its singular continuous spectrum is empty;
- its resolvent satisfies a class of a priori estimates.
5.
N. Barakat F. F. A. El-Shazly H. T. El-Shair 《Applied Physics A: Materials Science & Processing》1977,14(3):319-323
A new interferometric method is proposed, using white light fringes of equal chromatic order to determine simultaneously the following paramcters:
- The refractive index of a thin dielectric film, and hence its dispersion.
- The film thickness.
- The correct value of the order of interference.
- The phase shift occuring due to reflection at the dielectric/metal interface. In the present work, doubly silvered zinc sulphide (ZnS) thin dielectric film was used as an example in applying the proposed method.
6.
J. Ginibre 《Communications in Mathematical Physics》1969,14(3):205-234
We prove that the following lattice systems:
- anisotropic Heisenberg model,
- Ising model with transverse magnetic field,
- quantum lattice gas with hard cores extending over nearest neighbours,
7.
Noboru Nakanishi 《Letters in Mathematical Physics》1977,1(5):361-366
The following new findings are briefly reported:
- A consistent quantum theory can be formulated for a free massless scalar field in two-dimensional spacetime.
- Satisfactory operator solutions in terms of asymptotic fields can be constructed in the Thirring and Schwinger models.
- Gauge invariance is spontaneously broken in the Thirring model as well as in the Schwinger model.
8.
A. Zumsteg M. Ziegler Prof. Dr. W. Känzig M. Bösch 《Zeitschrift für Physik B Condensed Matter》1974,17(4):267-291
The phase transitions of Alkali-Hyperoxide crystals (NaO2, KO2, RbO2, and CsO2) grown in liquid ammonia have been investigated by means of the following measurements:
- magnetic susceptibility
- differential magnetic susceptibility as magnetic field
- magnetization curve in static and pulsed fields
- specific heat.
9.
Prof. Dr. Fritz Bopp 《Zeitschrift für Physik A Hadrons and Nuclei》1969,224(1-3):209-221
Starting from the four component Dirac equation for free particles without mass W.Heisenberg und W.Pauli have shown that the interaction term is uniquely defined, if one requires that all symmetries of free particles are preserved. Here we obtain similar results if we start from the eight component Dirac equation for free particles without mass:
- The symmetry group of the eight component Dirac equation for free particles without mass has 16 parameters. It is isomorph to the direct product of the SU 4 and a one-parametric group: SU 4× (1).
- The interaction operator is uniquely defined if one requires to preserve as many symmetries as possible of those given in (1).
- But some of the symmetries in (1) are necessarily broken, in particular that of SU 3. The symmetry of the interaction operator is given by SO 4× (1)× (1).
- The Heisenberg theory is uniquely defined, only if one assumes that the free particle part of the equation is well known.
- The theory can be changed without modifying the fundamental idea ofHeisenberg andPauli to deduce an uniquely defined interaction operator if one starts with a modified free particle part.
- A special kind of modification of the free particle part leads essentially to the SU 4-symmetry including that of SU 3, which is necessarily broken by the interaction term.
- The question arises if this break of the SU 3-symmetry has something to do with the real break. This question is not yet touched in this paper.
10.
11.
E. Boos I. Ginzburg K. Melnikov T. Sack S. Shichanin 《Zeitschrift fur Physik C Particles and Fields》1992,56(3):487-491
Three possibilities to observe the Higgs-top interation at future γγ-colliders are discussed:
- associated Higgs production via the \(\gamma \gamma \to t\bar tH\) reaction,
- Higgs obliged radiative correction to the \(\gamma \gamma \to t\bar t\) channel,
- Higgs resonance production via γγ→H→ZZ.
12.
In ferrites a large number of after-effects are found, with time constants between nano-seconds and years. In this review the after-effects due to ion-and electron motion will be treated. One finds:
- single-ion effects in combination with lattice deformations, e.g. Mn3+;
- ion effects caused by mobile vacancies, e.g. Co2+;
- effects due to electron transfer:
- Co2+?Co3+
- Me2+?Fe3+, in combination with Me4+ and vacancies.
- Me4+?Fe2+, with Me=Si, Ti (photomagnetic effect).
13.
A. Jánosi 《Zeitschrift für Physik B Condensed Matter》1990,80(3):393-400
We study the effects of some of the most important and typical structural changes in two-phase systems on selected structural parameters obtained from small-angle x-ray scattering (SAXS) measurements. To limit the present study, it was assumed that the Phase, 1, embedded in the matrix
- is monodispersed and homogeneous,
- possesses one of the three most extreme shapes (spherical, fibrillar or lamellar) and
- changes its behaviour
- through type change (spinodal or nucleotic or coarsening), without changing the shape,
- through a change of the shape only, or
- through a) (type change) and b) (shape change) simultaneously.
- chord lengthl 1 (and/or radius of gyrationR),
- volume partw 1 of the Phase 1, and
- relative inner surfaceS v of the system.
- spinodal change, all three SAXRS parameters are increasing or decreasing simultaneously and proportional to a power of the intensity of the change,
- nucleotic change,l 1 (and/orR) is unchanged, the other two (w 1 andS v ) are increasing or decreasing simultaneously and directly proportional to the intensity,
- coarsening change,w 1 is unchanged and anincreasing ofl 1 is always accompanied by adecreasing ofS v and vice versa.
14.
It is demonstrated that a closed symmetric derivation δ of aC?-algebra \(\mathfrak{A}\) generates a strongly continuous one-parameter group of automorphisms of aC?-algebra \(\mathfrak{A}\) if and only if, it satisfies one of the following three conditions
- (αδ+1)(D(δ))= \(\mathfrak{A}\) , α∈?\{0}.
- δ possesses a dense set of analytic elements.
- δ possesses a dense set of geometric elements.
- ∥(αδ+1)(A)∥≧∥A∥, α∈IR,A∈D(δ).
- If α∈IR andA∈D(δ) then (αδ+1)(A)≧0 impliesA≧0.
15.
The influence of frequency modulation of the rf field and modulation of the static magnetic field on NMR-response is investigated. The mathematical treatment using density operator formalism results in a different dynamical behaviour of the nuclei whether frequency—or field modulation is applied. Therefore a general equivalence of the two kinds of modulation does not exist. Explicite solutions for the nuclear magnetization with simultaneous frequency—and field modulation are evaluated for systems obeying Bloch equations. Resonance experiments have been performed using different detection methods:
- rf spectrum analysis of the nuclear induction emf from a decoupled (zero leakage) crossed coil setup.
- conventional lock-in detection of the signal information from an NMR-detector with single resonant circuit.
16.
J. C. M. Henning J. H. den Boef 《Applied Physics A: Materials Science & Processing》1978,16(4):353-357
A novel method for measuring magnetostriction constants is presented. A strain, periodic in time, applied to the sample, causes a modulation of the ferromagnetic resonance line position. The height of the signal obtained after phase-sensitive detection is proportional to the strain modulation depth. The appropriate magnetostriction constant λ is obtained by comparing the height of the SMFMR signal with that of the FMR line, as recorded by means of magnetic field modulation. Features of the new technique are:
- high sensitivity: λmin? 10?9 forM=100 Oe and linewidth ΔH d=1 Oe;
- λ's belonging to distinct precession modes are separately determined;
- applicable to thin layers for which strain gauge techniques cannot be used;
- wide temperature range: 1.2 K<T<300 K;
- uniform stress.
17.
Poly(methylmetacrylate)/poly(ethylene oxide) (PMMA/PEO) based polymer electrolytes were synthesized using the solution cast technique. Four systems of PMMA/PEO blends based polymer electrolytes films were investigated:
- PMMA/PEO system,
- PMMA/PEO + ethylene carbonate (EC) system,
- PMMA/PEO + lithium hexafluorophosphate (LiPF6) system and
- PMMA/PEO + EC + LiPF6 system.
18.
F. Halzen 《The European Physical Journal C - Particles and Fields》2006,46(3):669-687
Kilometer-scale neutrino detectors such as IceCube are discovery instruments covering nuclear and particle physics, cosmology and astronomy. Examples of their multidisciplinary missions include the search for the particle nature of dark matter and for additional small dimensions of space. In the end, their conceptual design is very much anchored to the observational fact that Nature produces protons and photons with energies in excess of 1020 eV and 1013 eV, respectively. The puzzle of where and how Nature accelerates the highest energy cosmic particles is unresolved almost a century after their discovery. The cosmic ray connection sets the scale of cosmic neutrino fluxes. In this context, we discuss the first results of the completed AMANDA detector and the science reach of its extension, IceCube. Similar experiments are under construction in the Mediterranean. Neutrino astronomy is also expanding in new directions with efforts to detect air showers, acoustic and radio signals initiated by super-EeV neutrinos. The outline of this review is as follows: Introduction Why kilometer-scale detectors? Cosmic neutrinos associated with the highest energy cosmic rays High energy neutrino telescopes: methodologies of neutrino detection High energy neutrino telescopes: status 相似文献
19.
Francesco Pegoraro 《Communications in Mathematical Physics》1975,42(1):41-63
We consider a theorem due to Michel [1] which relates the invariance properties in peculiar directions in a linear space on which we represent a Lie groupG to the extremal points of an arbitrary smoothG-invariant function. The group we are interested in isSO(4) and we apply the mathematical results to the following problems:
- mixed linear Stark Zeeman effect in a hydrogen atom,
- perturbation of a finite Robertson-Walker metric,
- gas evolutions preserving angular momentum and vorticity.
20.
V. Yu. Klepikov 《Radiophysics and Quantum Electronics》1996,39(10):857-861
Analyzing statistically the magnetic and Doppler velocity data for 85 quiescent prominences observed in 1983–1987 by Nikolsky's magnetograph, we came to the following preliminary conclusions: The average longitudinal magnetic field of the prominence determines the dynamic velocity of the latter: the stronger magnetic fields correspond to the higher Doppler velocities. A longitudinal magnetic field less than 25 G allows the material to move with arbitrary velocity within the limits of several kilometers per second. A magnetic field higher than 25 G suppresses such movements. The horizontal length of the flux tube exceeds its vertical part by 1.5 orders of magnitude (the upper limit). There is an angle of 10°between the horizontal component of the velocity vector in quiescent prominences and the long axis of the filament. The maximum velocity in quiescent prominences is about 7 km/s. 相似文献