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1.
From our experiments the following conclusions follow:
i)  The value of a in the l/f a law lies within the intervala (0.6, 1.0).
ii)  The detectors featuring low reverse currentI c havea 1.0.
iii)  The cutoff frequency of the noise characteristicf c is at low frequency compared with the using frequency band of the detector.
iv)  The excess noise is given by generation-recombination process in the volume of the space — charge region of the sample.
  相似文献   

2.
ForG a classical group, an equivalence is exhibited between:
A)  G monopoles over 3, with maximal symmetry breaking at infinity,
B)  families of (rank (G)) algebraic curves inT1, along with divisors on those curves, satisfying certain constraints,
C)  solutions of Nahm's equations over (rank(G)) intervals, satisfying the appropriate boundary conditions.
A) and B) are linked by twistor techniques, B) and C) via the Krichever method for solving non-linear differential equations, and A) and C) via the ADHMN construction, providing a unified picture of techniques for solution. Amongst other things, an asymptotic formula for the Higgs field of the monopole is computed.Communicated by A. Jaffe  相似文献   

3.
A structural similarity between Classical Mechanics (CM) and Quantum Mechanics (QM) was revealed by P.A.M. Dirac in terms of Lie Algebras: while in CM the dynamics is determined by the Lie algebra of Poisson brackets on the manifold of scalar fields for classical position/momentum observables Q/P, QM evolves (in Heisenberg's picture) according to the formally similar Lie algebra of commutator brackets of the corresponding operators:
#xA;\fracddtQ={Q,H}     \fracddtP={P,H}
#xA;   versus
#xA;    \fracddt\mathbb Q=\fraci(h/2p) [\mathbb Q,\mathbb H]     \fracddt\mathbb P=\fraci(h/2p) [\mathbb P,\mathbb H]
\displaylines{ \frac{d}{dt}Q=\{Q,H\} \quad \frac{d}{dt}P=\{P,H\} \quad\hbox{versus}\cr \quad \frac{d}{dt}{\mathbb Q}=\frac{\rm i}{\hbar}[{\mathbb Q},{\mathbb H}] \quad \frac{d}{dt}{\mathbb P}=\frac{\rm i}{\hbar}[{\mathbb P},{\mathbb H}]}  相似文献   

4.
In this talk the discussion of nuclear physics studied by hyperfine methods is limited to a few topics of high actuality:
(a)  Isomer shift data for 2+ rotational states gave r/r values much smaller than predicted by the simple centrifugal stretching model. They provide evidence for a strong Coriolis anti-pairing effect as recent detailed microscopic calculations show.
(b)  The Coriolis force causes also the famous back-bending effect at high rotational angular momenta. This phenomenon is not yet really understood. MeasuredgR values in this region would be very informative. The present situation of this challenging task is discussed.
(c)  Precisely measured magnetic dipole moments of high-spin few-particle states allow in favourable cases the derivation of the meson exchange contribution. The general situation and new results are reported.
(d)  Quite a few electric quadrupole moments of high spin states of several tin isotopes have recently been measured. The discussion in terms of the simple shell model reveals already interesting features. Especially the subshell filling effect is nicely exhibited.
  相似文献   

5.
6.
Recently, folk questions on the smoothability of Cauchy hypersurfaces and time functions of a globally hyperbolic spacetime M, have been solved. Here we give further results, applicable to several problems:
(1) Any compact spacelike acausal submanifold H with boundary can be extended to a spacelike Cauchy hypersurface S. If H were only achronal, counterexamples to the smooth extension exist, but a continuous extension (in fact, valid for any compact achronal subset K) is still possible.
(2) Given any spacelike Cauchy hypersurface S, a Cauchy temporal function (i.e., a smooth function with past-directed timelike gradient everywhere, and Cauchy hypersurfaces as levels) with is constructed – thus, the spacetime splits orthogonally as in a canonical way.
Even more, accurate versions of this last result are obtained if the Cauchy hypersurface S were non-spacelike (including non-smooth, or achronal but non-acausal).  相似文献   

7.
8.
9.
Let
Let N be a positive integer and define Φ(N) as the number of matrices, C, which are products of A and B, where both A and B must occur, such that the trace, Tr(C)=N. It has been conjectured that
see [10]. In this note we consider the summatory function
and show that
Received: 4 January 2001 / Accepted: 10 April 2001  相似文献   

10.
《Physics Reports》1999,310(1):1-96
  相似文献   

11.
This paper continues the analysis of the quantum states introduced in previous works and determined by the universal asymptotic structure of four-dimensional asymptotically flat vacuum spacetimes at null infinity M. It is now focused on the quantum state λ M , of a massless conformally coupled scalar field propagating in M. λ M is “holographically” induced in the bulk by the universal BMS-invariant state λ defined on the future null infinity of M. It is done by means of the correspondence between observables in the bulk and those on the boundary at future null infinity discussed in previous papers. This induction is possible when some requirements are fulfilled, in particular whenever the spacetime M and the associated unphysical one, M͂, are globally hyperbolic and M admits future time infinity i +. λ M coincides with Minkowski vacuum if M is Minkowski spacetime. It is now proved that, in the general case of a curved spacetime M, the state λ M enjoys the following further remarkable properties:
Contents
1. Introduction4
1.1. The basic questions4
1.2. Other approaches8
1.3. Outline of the paper11
2. Adiabatic accessibility and construction of entropy12
2.1. Basic concepts13
2.2. The entropy principle19
2.3. Assumptions about the order relation21
2.4. The construction of entropy for a single system24
2.5. Construction of a universal entropy in the absence of mixing29
2.6. Concavity of entropy32
2.7. Irreversibility and Carathéodory’s principle35
2.8. Some further results on uniqueness36
3. Simple systems38
3.1. Coordinates for simple systems40
3.2. Assumptions about simple systems42
3.3. The geometry of forward sectors45
4. Thermal equilibrium54
4.1. Assumptions about thermal contact54
4.2. The comparison principle in compound systems59
4.3. The role of transversality64
5. Temperature and its properties67
5.1. Differentiability of entropy and the existence of temperature67
5.2. Geometry of isotherms and adiabats73
5.3. Thermal equilibrium and uniqueness of entropy75
6. Mixing and chemical reactions77
6.1. The difficulty in fixing entropy constants77
6.2. Determination of additive entropy constants79
7. Summary and conclusions88
7.1. General axioms88
7.2. Axioms for simple systems88
7.3. Axioms for thermal equilibrium88
7.4. Axiom for mixtures and reactions89
Acknowledgements92
Appendix A92
A.1. List of symbols92
A.2. Index of technical terms93
References94
(i)  λ M is invariant under the (unit component of the Lie) group of isometries of the bulk spacetime M.
(ii)  λ M fulfills a natural energy-positivity condition with respect to every notion of Killing time (if any) in the bulk spacetime M: If M admits a time-like Killing vector, the associated one-parameter group of isometries is represented by a strongly-continuous unitary group in the GNS representation of λ M . The unitary group has positive self-adjoint generator without zero modes in the one-particle space. In this case λ M is a so-called regular ground state.
(iii)  λ M is (globally) Hadamard in M and thus it can be used as the starting point for the perturbative renormalisation procedure of QFT of in M.
  相似文献   

12.
About two hundred Stark resonances of the ν2 and ν5 vibration-rotation bands of CD335Cl, using a 9.4 μm CO2 laser as a source, have been measured. By combining these data with the zero-field microwave spectra the following molecular constants have been determined (with the standard deviations in parentheses):
  相似文献   

13.
A heat engine is a machine which uses the temperature difference between a hot and a cold reservoir to extract work. Here both reservoirs are quantum systems and a heat engine is described by a unitary transformation which decreases the average energy of the bipartite system. On the molecular scale, the ability of implementing a (good) unitary heat engine is closely connected to the ability of performing logical operations and classical computing. This is shown by several examples:
ν2ν5
ν01 028.67275 (15)1 059.96970 (11)(cm?1)
A78 765.20 (89)78 030.21 (109)(MHz)
B110 805.29 (26)10 860.10 (13)(MHz)
5?25 080.77 (99)(MHz)
D8 756.0 (43)(MHz)
μ1.90741 (33)1.90607 (36)(D)
μ(ground state)1.90597 (33)(D)
(1)  The most elementary heat engine is a SWAP-gate acting on 1 hot and 1 cold two-level systems with different energy gaps.
(2)  An optimal unitary heat engine on a pair of 3-level systems can directly implement OR and NOT gates, as well as copy operations. The ability to implement this heat engine on each pair of 3-level systems taken from the hot and the cold ensemble therefore allows universal classical computation.
(3)  Optimal heat engines operating on one hot and one cold oscillator mode with different frequencies are able to calculate polynomials and roots approximately.
(4)  An optimal heat engine acting on 1 hot and n cold 2-level systems with different level spacings can even solve the NP-complete problem KNAPSACK. Whereas it is already known that the determination of ground states of interacting many-particle systems is NP-hard, the optimal heat engine is a thermodynamic problem which is NP-hard even for n non-interacting spin systems. This result suggests that there may be complexity-theoretic limitations on the efficiency of molecular heat engines.
  相似文献   

14.
Using CO2 and N2O lasers, we have measured and assigned nineteen ν4 and nine ν6 rotation-vibration resonances of the type ΔM = 0 and M = J. These transitions were combined with the zero-field pure rotational spectra in order to determine the two fundamental vibrational frequencies, the rotational constants of both excited states, the Coriolis coupling constant, and the dipole moments of each of the three states. The ground-state rotational constants and centrifugal distortion constants were taken from a microwave study and the centrifugal distortion constants of the excited states were assumed equal to those of the ground state. The following results were obtained (standard deviations in parentheses):
  相似文献   

15.
The (0,0) bands of nine prominent electronic transitions, Systems X, XI, and XVI through XXII, in the wavelength region 500–800 nm were studied. High-precision (±0.005 cm?1), Doppler-limited, selectively detected cw-dye laser fluorescence excitation spectra for Systems XVI through XXII were recorded and analyzed. Definitive Ω assignments for the upper and lower states of these transitions were established from identified first lines in the P and R branches. Resolved fluorescence studies revealed 22 additional electronic transitions in the same wavelength region, many of which provide energy linkages between the upper or lower states of previously observed transitions. The comprehensive energy level diagram assembled from 31 electronic transition linkages comprises a total of 22 upper and lower electronic levels. Ω assignments and relative energies for the electronic states of the transitions studied (including Systems XIV and IX identified in fluorescence and the proposed assignment for System VI) are
ν4ν6
ν0938.0345 (6)989.2519 (18)(cm?1)
A139 579 (150)143 323 (150)(MHz)
B31 873.6 (5)32 379.5 (7)(MHz)
C26 242.9 (6)25 994.4 (8)(MHz)
ξ64(a)136 178 (770)(MHz)
μ2.319 (10)2.347 (4)(D)
μ(ground state)2.3464 (8)(D)
  相似文献   

16.
We consider a model of a random copolymer at a selective interface which undergoes a localization/delocalization transition. In spite of the several rigorous results available for this model, the theoretical characterization of the phase transition has remained elusive and there is still no agreement about several important issues, for example the behavior of the polymer near the phase transition line. From a rigorous viewpoint non coinciding upper and lower bounds on the critical line are known. In this paper we combine numerical computations with rigorous arguments to get to a better understanding of the phase diagram. Our main results include:
SystemΩ′T′0 (cm?1)Ω″T″0 (cm?1)
VI5.5111024.52157
IX4.5165973.53887
X5.5132594.5220
XI5.5138654.5220
XIV5.5165954.52157
XVI5.5191694.53720
XVII4.5165973.50
XVIII7.5213216.53965
XIX6.5196875.52111
XX5.5180694.5220
XXI4.5188854.5220
XXII5.5191694.5220
–  Various numerical observations that suggest that the critical line lies strictly in between the two bounds.
–  A rigorous statistical test based on concentration inequalities and super–additivity, for determining whether a given point of the phase diagram is in the localized phase. This is applied in particular to show that, with a very low level of error, the lower bound does not coincide with the critical line.
–  An analysis of the precise asymptotic behavior of the partition function in the delocalized phase, with particular attention to the effect of rare atypical stretches in the disorder sequence and on whether or not in the delocalized regime the polymer path has a Brownian scaling.
–  A new proof of the lower bound on the critical line. This proof relies on a characterization of the localized regime which is more appealing for interpreting the numerical data.
2000 MSC: 60K37, 82B44, 82B80  相似文献   

17.
We consider two-dimensional Bernoulli percolation at densityp>p c and establish the following results:
1.  The probability,P N (p), that the origin is in afinite cluster of sizeN obeys
  相似文献   

18.
Six bands of the A1Π-X1Σ system of CD+ in the region 3800–4800 Å have been recorded in emission using an aluminum hollow-cathode discharge in the HeC2H2 mixture. From the vibrational and rotational analysis of the observed bands, the following constants (cm?1) are obtained:
  相似文献   

19.
Rotational analysis of 13 emission bands of PrO belonging to 10 different systems was carried out. The derived constants are as follows:
T00ωeωexeωeyeBeDe·104αe
A1Π23 747.51367.360.60.756.4285.70.388
X1Σ020357.6504.10.190
(2101.6)(33.3)
  相似文献   

20.
ν0B′D′ × 107B″D″ × 107
18 665.19(1)0.3530(1)1.80(5)0.3622(1)2.85(1)
18 613.22(1)0.3517(1)0.4(3)0.3606(1)2.4(2)
17 842.32(1)0.3560(1)3.0(1)0.3621(1)2.7(1)
17 796.09(4)0.3532(3)2.4(8)0.3604(2)2.7(6)
18 628.22(3)0.3530(6)1.8(8)0.3620(5)2.7(7)
14 426.12(2)0.3519(1)5.5(6)0.3620(1)1.9(6)
13 541.44(2)0.3500(2)3.7(5)0.3605(2)2.3(5)
13 645.78(8)0.3511(3)3.1(5)0.3620(2)2.8(5)
12 961.98(4)0.3445(4)4.5(4)0.3603(3)2.3(7)
9 600.47(1)0.3454(1)2.8(2)0.3620(1)3.0(3)
16 591.29(1)0.3536(1)0.5(2)0.3610(1)2.6(1)
11 912.89(1)0.3480(2)8.5(8)0.3610(1)2.2(6)
10 429.62(2)0.3450(1)3.1(1)0.3610(1)3.0(3)
1)  Physics. In the calculation of g-loop string tachyon amplitudes withn scattering points the distinguished Polyakov measure d g,n on the moduli spaceM g,n of Riemann surfaces of genus g withn punctures arises. We give an interpretation of this measure as the modulus squared of a holomorphic section g,n (the Mumford form) of a certain holomorphic line bundle, i.e., we prove an analog of the Belavin-Knizhnik theorem d g,n =| g,n |2 in the amplitudic case. We give an expression for this measure through the determinants of the Laplace operators over ghosts and over multivalued fields with monodromy prescribed by momenta at the scattering points. We show also that the form g,n (n0) (n0) for the partition function andn-point amplitudes can be obtained from a unified over alln, universal Mumford form.
2)  Mathematics. The following new concepts from the theory of complex algebraic curves are investigated: divisors with complex coefficients, complex powers of holomorphic line bundles, determinants of Laplace operators over multivalued functions, etc. The corresponding generalizations of the determinant line bundles, the Weil-Deligne pairings, the Quillen and the Arakelov-Deligne metrics are constructed. A suggested by string amplitude considerations analog of the Mumford theorem on holomorphic triviality of the bundle 2 1 -13 over the moduli space is given. This analog asserts the existence of a canonical flat metric on a certain line bundle (see the main body of the text). There exist two differences: the latter bundle is not holomorphically trivial but has a canonical flat metric, and, being defined on the Teichmüller spaceT g, n , this bundle can be pulled down only on an infinite-sheeted covering of the moduli spaceM g,n . The universal isometries and the relative curvatures from the second part of the paper may be interesting, too.
Communicated by A. Jaffe  相似文献   

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