共查询到20条相似文献,搜索用时 31 毫秒
1.
Bosisio Renato G. Nachman Manfred Spooner Jacques 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1974,2(4):273-276
Measurements on RF power absorption in microwave discharges at 2.45 GHz, at pressures from 1 to 30 Torr in N2 and from 1 to 500 Torr in Ar, are described. A linear slow-wave structure of the strapped-bar type was employed for coupling RF energy to the plasma. From measurements on the plasma volume and on the total power absorbed, the variation with gas pressure of the RF power density in the plasma was obtained. For an incident power of 1 kW, power densities as high as 2-3 W/cm3 over relatively large plasma volumes could be achieved. The experimental data were used to calculate the pressure dependence of the electron density in an argon plasma, for an incident power of 1 kW. 相似文献
2.
3.
当外电路的电阻等于电源内电阻时,电源输出功率最大,应用这个结论,可以省去许多计算步骤.但实际应用时还要注意一些问题,下面从几个方面加以讨论.1 电源实际输出功率与最大输出功率的区别 这是两个不同的概念,一些学生往往会用Pm=(?)/4r计算电源输出最大功率,其实,(?)/4r只是电源输出功率的极限,电源一般不在该状态下工作. 相似文献
4.
L. M. Brown 《哲学杂志》2016,96(26):2696-2713
Starting from the idea that plastic flow produces dislocation structures in a state of self-organised criticality, it is shown that one expects power-law relationships between variables. If slip bands are modelled as avalanches of shear with an ellipsoidal shape, slightly tilted from the crystallographic slip plane, limited in size by interaction with secondary slip, the observed exponents of the power laws can be rationalised. In some cases, the constant of proportionality can also be estimated, and found to agree with experiment, even though the detailed mechanism of avalanche formation is not addressed. To analyse creep data and slip-band statistics, it is further assumed that the role of cross-slip is to eliminate screw dislocation dipoles, removing them entirely at stresses found in Stage III of work-hardening. If physical constants, such as the atomic vibration frequency, play a role, the dimensionless power-law relationships do not apply. One then finds creep rates linear in stress and absolute temperature, proportional to the logarithm of time, obeying an equation of state, as observed. 相似文献
5.
J. L. Friar 《Few-Body Systems》1997,22(4):161-193
Weinberg's dimensional power counting for nuclei is reprised in this primer. The role of QCD and chiral symmetry in constructing
effective Lagrangians is discussed. The two-scale hypothesis of Manohar and Georgi is combined with power counting in amplitudes
to shed light on the scales of nuclear kinetic and potential energies, the size of strong-interaction coupling constants,
the size of meson-exchange currents, and the relative sizes of many-nucleon forces. Numerous examples are worked out and compared
to conventional nuclear models.
Received July 12, 1996; revised November 17, 1996; accepted for publication February 10, 1997 相似文献
6.
Russian Physics Journal - Dynamics and radiation of a charged particle moving in a constant electromagnetic field and possessing a linear dispersion law ε(p)?=?νF|p| are... 相似文献
7.
Richard T. Hammond 《General Relativity and Gravitation》1997,29(6):727-731
The demand for gravitation with torsion spans the realm from classical general relativity, where conservation of total angular momentum plus intrinsic spin requires the need for torsion, to string theory, which calls for the necessity of torsion as an antisymmetric field. Despite both the intense theoretical activity and the experimental efforts to measure torsion, research into the mechanisms of the production and radiation of torsion has been severely neglected. It is shown that torsion waves can be generated by particles with spin, and the radiated power is computed. With these results, new generations of experiments may be developed that could measure torsion waves, the effects on rotating collapsed objects, and the role of torsion waves in the development of the early universe. 相似文献
8.
采用二阶类Kuramoto模型对电网进行合理建模,分别应用临界同步耦合强度和平均同步误差来描述电网的同步能力和鲁棒性.研究发现,发电机的功率分配对线路的传输功率影响较大,而电网中高负荷线路越多,网络越难同步.基于这一发现,首先在发电机功率均匀分配(EG)方式下,计算出每条线路的传输功率,然后基于潮流追踪算法提出一种发电机功率非均匀分配(TG)方式,即在发电总量不变的情况下,增大枢纽发电机节点的功率,减小边缘发电机节点的功率.该发电机功率分配策略可以在一定程度上降低网络的临界同步耦合强度,减小平均同步误差,改善电网的同步性能和鲁棒性. 相似文献
9.
Jean Farago 《Journal of statistical physics》2002,107(3-4):781-803
In this paper, we consider the Langevin equation from an unusual point of view, that is as an archetype for a dissipative system driven out of equilibrium by an external excitation. Using path integral method, we compute exactly the probability density function of the power (averaged over a time interval of length ) injected (and dissipated) by the random force into a Brownian particle driven by a Langevin equation. The resulting distribution, as well as the associated large deviation function, display strong asymmetry, whose origin is explained. Connections with the so-called Fluctuation Theorem are thereafter discussed. Finally, considering Langevin equations with a pinning potential, we show that the large deviation function associated with the injected power is completely insensitive to the presence of a potential. 相似文献
10.
Low-loss glass-based buried multimode waveguides are fabricated by using the field-assisted Ag+-Na+ ionexchange technique, and multimode optical power splitters are investigated. The measured loss of the multimode waveguides is lower than 0.1 dB/cm, and the additional loss of the multimode optical power splitters is lower than 1.3 dB under the uniform splitting condition. 相似文献
11.
高功率全光纤光载微波信号功率放大器 总被引:1,自引:0,他引:1
为获得可应用于光载微波雷达系统的高功率双频激光源,用1 064nm窄线宽Nd∶YAG单块非平面环形腔激光器作为单频种子源,其输出分为两路,一路直接耦合入光纤,另一路经声光移频,与未移频的光束合束后获得中心频差为150 MHz、功率为20mW的双频激光.利用以半导体激光泵浦和掺Yb3+石英光纤为增益介质的3级主振荡功率放大系统对双频固体激光器输出的双频激光进行放大,获得50.3W的双频放大输出,光束质量因子为1.30,第三级主放大斜效率为74%.双频成分的幅度比、频差在放大过程中得到保持,拍频调制深度及信噪比等特性也未有恶化.双频光纤功率放大器在频差稳定和高功率输出等方面均有良好的表现. 相似文献
12.
Lloyd S 《Physical review letters》2003,90(16):167902
A communication channel is a physical system that transfers information from one place to another. Examples of communication channels include wires, optical fibers, and chains of spins that propagate spin waves through a medium. This Letter shows that the power-limited communication capacity of a multimode optical fiber or a set of parallel spin chains can be enhanced by introducing nonlinear couplings between the modes or chains. In particular, M coupled, entangled modes can send M bits in the same time it takes a single mode to send a single bit, and in the same time it takes M uncoupled, unentangled modes to send sqrt[M] bits. 相似文献
13.
M. Mohsenzadeh S. Rouhani M. V. Takook 《International Journal of Theoretical Physics》2009,48(3):755-762
The power spectrum of scalar field and space-time metric perturbations produced in the process of inflation of universe, have
been presented in this paper by an alternative approach to field quantization namely, Krein space quantization (Gazeau et
al. in Class. Quantum Gravity 17:1415, 2000; Takook in Int. J. Mod. Phys. E 11:509, 2002; Rouhani and Takook in ). Auxiliary negative norm states, the modes of which do not interact with the physical world, have been utilized in this
method. Presence of negative norm states play the role of an automatic renormalization device for the theory. 相似文献
14.
HighPowerPulsedLaserPowerSupplyBasedonIGBTWANGXueli;YUYizhong;ZHANGRui;WuFeng;YAOJianquan(PrecisionInstrumentDepartment,Tianj... 相似文献
15.
16.
17.
18.
19.