Quasi-reciprocal reflective optical voltage sensor based on Pockels effect with digital closed-loop detection technique

A novel Pockels effect based optical voltage sensor (OVS) consisting of quasi-reciprocal reflective optical circuit is proposed and demonstrated in this paper. The quasi-reciprocal reflective optical circuit is realized so that a digital closed-loop detection technique adopted from fiber gyroscopes can be introduced to obtain the voltage-induced Pockels phase. Due to the digital closed-loop detection scheme, the proposed OVS is insensitive to the fluctuation of the light intensity and the dynamic range is independent of the half-wave voltage of the Pockels crystal compared to the conventional crystal bulk-type with the light intensity based detection scheme. A prototype of the proposed OVS is designed and evaluated. The calculated results of the electric field distribution show that the maximal measured voltage of the sensing element is up to 15 kV. The dc voltage from 0 to 3000 V and 50 Hz ac voltage from 0 to 5000 V are measured with good linearity. The proposed OVS achieves accuracy within ± 1% and ± 0.44% with the measured dc voltage above 800 V and ac voltage above 500 V, respectively. The influences of the alignment error in the sensing element on the measurement accuracy are also theoretically analyzed and experimentally verified.     

Atomic partial charges in condensed phase from an exact sum rule for infrared absorption

A general sum rule for infrared intensities provides a definition of effective partial charges which can be experimentally obtained using isotopic substitutions and is valid in both gas and condensed phases. Of particular interest is the case of molecular liquids. We have, therefore, determined the hydrogen partial charges in liquid methanol and liquid water from the available literature. The resulting charges are 0.63 e and 0.14 e for hydrogen atoms bounded to the methanol oxygen and carbon atoms, respectively, and 0.55 e for hydrogen atoms in liquid water. The effective partial charges in liquid water were also computed from density functional based ab initio molecular dynamics simulations and found in good agreement with experiment.     

0.25-μm PMOSFETs中热载流子的退化特性和解释

本文研究了深亚微米PMOSFETs的热载流子效应。研究发现热载流子效应包括界面态的产生和氧化层中固定正电荷的形成。通过实验证明了深亚微米PMOSFETs中这两种机制的重要性。首先，氧化层固定正电荷的产生在深亚微米PMOSFETs中起作用，使得器件的阈值电压退化，最终限制了表面沟道晶体管的使用寿命。对于先进的模拟和混合信号的应用，工艺和器件的可靠性必须按照阈值电压的漂移重新定义，而不仅仅依照跨导的退化或者栅氧化层的寿命来定义。其次，空穴注入产生的界面态也影响器件的特性。推断了热载流子效应的形成过程。     

Topological Dyons

Using a two potential approach, dyon solutions have been found in the temporal and non-temporal gauges for a non-Abelian theory. Both the charges, electric and magnetic, of the temporal dyon solution are topological, while for the non-temporal case both charges are partially topological.     

Highly charged ions in field evaporating 4d-transition metals

An energy-focused time-of-flight atom-probe has been employed in a search for high ionic charges obtained in field-evaporating Zr, Nb, Mo, Rh, Pd and Ag, the 4d-transition metals. Although no new higher charges than the already established ones are found for these metals the maximum abundance of the highest charge is determined in each case. An empirical rule predicting the limits of the charge of field-evaporating ions is proposed.     

An unexpected result in Einstein–Maxwell electrostatics

I examine a known exact static solution of the Einstein–Maxwell equations representing the exterior field of two charged masses. I find a property totally unexpected according to classical electrostatics: the electric field does not vanish between two like charges. The point where it does vanish (electrically neutral point) is found in the general case.     

From screening to confinement in a Higgs-like model

We investigate a recently proposed Higgs-like model [G. Gabadadze, R.A. Rosen, arXiv:0811.4423 [hep-th]], in the framework of a gauge-invariant but path-dependent variables formalism. We compute the static potential between test charges in a condensate of scalars and fermions. In the case of charged massive scalar we recover the screening potential. On the other hand, in the Higgs case, with a “tachyonic” mass term and a quartic potential in the Lagrangian, unexpected features are found. It is observed that the interaction energy is the sum of an effective-Yukawa and a linear potential, leading to the confinement of static charges.     

介质中双缺陷电荷对碳纳米管场效应晶体管量子输运特性的影响

用非平衡格林函数理论和紧束缚模型近似计算长沟道弹道输运p型碳纳米管场效应管中电流强度.研究当场效应管介质（SiO₂）中存在两个带电缺陷时，载流子散射所引起的电流强度减小和栅极阈值电压偏移量与缺陷位置的关系.介质中两个缺陷所带电荷Q₁=Q₂=+e（-e为电子电荷），都靠近源极或者都靠近漏极，或者一个电荷靠近源极另一个电荷靠近漏极.在工作状态下，所引起的电流强度相对减小比介质中只存在单个正电荷Q=+e且靠近源极（或漏极）时所引起的电流强度相对减小大得多.如果两个正电荷都在沟道中央附近，随着两个电荷的轴向距离减小，栅极阈值电压偏移的绝对值明显增加.栅极阈值电压偏移可达到-0.35 V.     

Silicon surface passivation by static charge

A properly passivated silicon surface is chemically stable, and all interface properties are constant. The silicon dioxide layers fulfil the chemical stability requirements; however, their surface and interface charges have effect on the silicon surface potential barrier. Positive charge is usually assumed at the oxide-silicon interface, thus depletion or inversion layer develops in the case of p and accumulation in the case of n-type silicon.The surface of silicon dioxide can be charged macroscopically by corona charger or by conductive rubber stamp, microscopically by a tip of some scanning probe microscope (STM or AFM). The oxide surface usually retains the charges for a long time, however in the case of ultra-thin or other leaky oxide continuous charging it is necessary to keep the constant surface potential.The main purpose of this work is to summarize the possibilities of charging up the surface, the effect of the surface and interface charge on the surface properties of the silicon. The rearrangement of the surface charges will also be discussed.     

On parallel displacement within the light cone and its application in the electrodynamics of charges moving with the velocity of light

It is shown that there exists on the light cone an affine connection which is metric, semisymmetric and locally integrable. There exists a correspondence between this connection and a system of charges moving with the velocity of light. The correspondence reveals in the case of commensurable charges a symmetry which disappears for non-commensurable charges.     

A method to compare quark and gluon jets in $$e^ + e^ - \to q\bar qg$$ hadronisation

The conserved charges of non-abelian gauge theories are systematically investigated in the framework of the manifestly-covariant canonical formalism. An internal-symmetry superalgebra consisting of 4n+5 generators is found in the Landaugauge case of the Yang-Mills theory, wheren denotes the dimension of the gauge group. Likewise, a superalgebra consisting of 4×6+5 generators is found in the internal-Lorentz (local-Lorentz) part of the vierbein formalism of quantum gravity. It is pointed out that there is a complete parallelism between both superalgebras.     

Correspondence between Electrostatics and Contact Mechanics with Further Results in Equilibrium Charge Distributions

It is common in mesoscopic systems to find instances where several charges interact among themselves. These particles are usually confined by an external potential that shapes the symmetry of the equilibrium charge configuration. In the case of classical charges moving on a plane and repelling each other via the Coulomb potential, they possess a ground state à la Thomson or Wigner crystal. As the number of particles N increases, the number of local minima grows exponentially and direct or heuristic optimization methods become prohibitively costly. Therefore the only feasible approximation to the problem is to treat the system in the continuum limit. Since the underlying framework is provided by potential theory, we shall by-pass the corresponding mathematical formalism and list the most common cases found in the literature. Then we prove a (albeit known) mathematical correspondence that will enable us to re-discover analytical results in electrostatics. In doing so, we shall provide different methods for finding the equilibrium surface density of charges, analytical and numerical. Additionally, new systems of confined charges in three-dimensional surfaces will be under scrutiny. Finally, we shall highlight exact results regarding a modified power-law Coulomb potential in the d-dimensional ball, thus generalizing the existing literature.     

Null-plane charges and fourier transforms for explicitly and spontaneously broken symmetries

It is shown that the existence of null-plane charges and null-plane Fourier transforms (which enter into the discussion of current algebra at infinite momentum) depends on the high energy asymptotic behaviour of off mass shell scattering amplitudes; s In s behaviour is the maximum growth allowed. Under the assumption that asymptotic states exist, these results also hold in the case of spontaneously broken chiral symmetry with massless pseudoscalar Goldstone bosons. In this case, the resulting charges are the non-conserved pole-free charges suggested by Carlitz et al.     

The energy of two color charges in the g→∞ limit of QCD in the polar representation

The energy of two color charges is studied in the g→∞ limit of QCD in the polar representation. It is found that there is no confining potential, and confinement depends on whether the Gauss constraint is imposed in classical or in operator form. Only in the latter case quarks cannot be separated.     

Energy distribution extraction of negative charges responsible for positive bias temperature instability

A new method is proposed to extract the energy distribution of negative charges, which results from electron trapping by traps in the gate stack of n MOSFET during positive bias temperature instability(PBTI) stress based on the recovery measurement. In our case, the extracted energy distribution of negative charges shows an obvious dependence on energy,and the energy level of the largest energy density of negative charges is 0.01 e V above the conduction band of silicon. The charge energy distribution below that energy level shows strong dependence on the stress voltage.     

The N = 2 supersymmetric generalization of the complex sine-gordon model

A two-dimensional field theoretical model endowed with a Lax pair and invariant under complex supersymmetry is written in a manifestly invariant formulation. The bosonic limit of the model reproduces the complex sine-Gordon equations [that is the reduced O(4) σ-model introduced by Pohlmeyer, Lund-Regge and Getmanov]. The supersymmetry algebra contains central charges which generalize the one found by Witten and Olive in the super sine-Gordon case.     

A New Localization Method Using an Adiabatic Pulse,BIR-4

A new method is described for accomplishing localized spectroscopy with an adiabatic pulse, BIR-4. The method has advantages similar to previously described combinations of outer-volume suppression (OVS) and ISIS, with the additional advantages that localization is achieved with only three radiofrequency pulses and the localization remains accurate even in the presence of intense signals with short relaxation times. This new localization pulse sequence is referred to as integrated OVS-ISIS. Computer simulations, experimental images of the localized volumes, and in vivo¹H spectroscopy measurements demonstrate the high degree of localization achievable with integrated OVS-ISIS.     

Conserved charges and supersymmetry in principal chiral and WZW models

Conserved and commuting charges are investigated in both bosonic and supersymmetric classical chiral models, with and without Wess–Zumino terms. In the bosonic theories, there are conserved currents based on symmetric invariant tensors of the underlying algebra, and the construction of infinitely many commuting charges, with spins equal to the exponents of the algebra modulo its Coxeter number, can be carried out irrespective of the coefficient of the Wess–Zumino term. In the supersymmetric models, a different pattern of conserved quantities emerges, based on antisymmetric invariant tensors. The current algebra is much more complicated than in the bosonic case, and it is analysed in some detail. Two families of commuting charges can be constructed, each with finitely many members whose spins are exactly the exponents of the algebra (with no repetition modulo the Coxeter number). The conserved quantities in the bosonic and supersymmetric theories are only indirectly related, except for the special case of the WZW model and its supersymmetric extension.     

Disjoining pressure of discrete surface charges on thin aqueous films

The disjoining pressure of charged parallel interfaces confining an electrolyte solution is to a large extent determined by the screening clouds of the surface charges. We evaluate the pressure in terms of the number density sigma of discrete charges and film thickness d and find, at sigmad(2) approximately 1, a crossover from the well-known law P approximately sigma(2) to a linear behavior P approximately sigma. For the latter case, each surface charge results in strongly inhomogeneous pressure profiles at both interfaces.