Phase-dependent properties for absorption and dispersion in a closed equispaced three-level ladder system

It is shown that in a closed equispaced three-level ladder system, by controlling the relative phase of two applied coherent fields, the conversion from absorption with inversion to lasing without inversion (LWI) can be realized; a large index of the refraction with zero absorption can be gotten; considerable increasing of the spectrum region and value of the LWI gain can be achieved. Our study also reveals that the incoherent pumping will produce a remarkable effect oil the phase-dependent properties of the system. Modifying value of the incoherent pumping can change the property of the system from absorption to amplification and enhance significantly LWI gain. If the incoherent pumping is absent, we cannot get any gain for any value of the relative phase. (c) 2007 Elsevier GmbH. All rights reserved.

Phase control of gain and dispersion in an open V-type system

The control role of the relative phase between the probe and driving fields on gain, dispersion and populations in an open V-type three-level system with spontaneously generated coherence is studied. The result shows that by adjusting the value of the relative phase, the transformation between lasing with inversion and lasing without inversion (LWI) can be realized and high dispersion (refractive index) without absorption can be obtained. The shape and value range of the dispersion curve are similar to those of the gain curve, and this similarity is closely related to the relative phase. The effects of the atomic exit and injection rates and the incoherent pump rate on the control role of the relative phase are also analysed. It is found easier to get LWI by adjusting the value of the relative phase using the open system rather than the closed system, and using an incoherent pump rather than without using the incoherent pump. Moreover the open system can give a larger LWI gain than the closed system.

Temperature Dependence of the Tribological Properties of Laser Re-Melted Al-Cu-Fe Quasicrystalline Plasma Sprayed Coatings

The aim of this study was to investigate the effect of temperature on tribological properties of plasma-sprayed Al-Cu-Fe quasicrystal (QC) coating after laser re-melting treatment. The laser treatment resulted in a more uniform, denser and harder microstructure than that of the as-sprayed coatings. Tribological experiments on the coatings were conducted under reciprocating motion at high frequency in the temperature range from 25 to 650 degreesC. Remarkable influence of temperature on the friction behavior of the coating was recorded and analyzed. Microstructural analysis indicated that the wear mechanisms of the re-melted QC coatings changed from abrasive wear at room temperature, to adhesive wear at 400 degreesC and severe adhesive wear at 650 degreesC owing to the material transfer of the counterpart ball. It was also observed that the ratio of the icosahedral (i)-phase to beta-Al-50(Fe,CU)(50) phase in the coating was higher after test at 400 'C than that at 650 'C. The variation of the ratio UP of coating and of the property of the counterpart ball and coating with the temperature are the two main factors influencing the wear mechanisms and value of the friction coefficient.

The tunable negative refractive index in granular composite

The effective refractive index of a kind of granular composite, which consists of granular metallic and magnetic inclusions with different radius embedded in a host medium, is theoretically investigated. Results show that for certain volume fractions of these two inclusions, the negative permittivity peak shifts to low frequency and the peak value increases with increasing radius ratio of the radius of magnetic granulae to that of metallic granulae. Simultaneously, peak value of permeability decreases with the radius ratio, and value peak shifts to high frequency with increasing volume fraction of magnetic inclusion. Therefore, the radius ratio can affect the effective refractive index considerably, and it is found that by adjusting the radius ratio, the refractive index may change between negative and positive values for certain volume fractions of the two inclusions. (c) 2005 Elsevier B.V. All rights reserved.

组织中的规则行为：合法性、个体差异的认同-内化作用

This study employed the compliance, identification, and internalization model of attitude change to explore the mechanism of rule-following behaviors in organizations. The objectives of this study were to examine the effects of individual utilitarianism and formalism on rule compliance, deference and rule-breaking behaviors, and the relationships between legitimacy, organizational identification, and value internalization. I surveyed 262 employees from a high-tech corporation in Beijing. After Confirmative Factor Analysis, Regression Analysis, and Structural Equation Modeling, I summarized main conclusions as follow. First, rule legitimacy and organizational identification have different effects on different rule behaviors. Perceived rule legitimacy and organizational identification have direct positive effect on rule deference. But the effects of legitimacy on rule-compliance and rule-breaking are moderated by organizational identification and value internalization. Only under high identification or value congruence with organization, could legitimacy perception predict rule compliance and breaking. Second, individual formalism (IF) has positive effect on rule compliance. IF’s positive effect on rule deference only appear under high value congruence between individuals and organization. Third, organizational identification works as a “valve” in the relationship between individual viewpoints and rule-breaking. Organizational identification turns off the tendency of utilitarianism to break rules, and turns on the tendency of formalism to inhibit rule-breaking. Forth, attitudinal and behavioral facets of utilitarianism and formalism have different influences on rule-following behaviors. Only individuals who are both attitudinal and behavioral formalists show deference to rules, while formalism as behavioral tendency predicts less rule-breaking. Fifth, innovation behaviors coexist independently with compliance and deference to rules. But the division between innovation and rule-breaking is obscure. Organizational identification facilitate both rule following and innovation. Sixth, women comply with rules more than men do, while men break more rules than women do. More aged people develop deeper identification with their organizations, and higher deference to rules. Individuals with higher education are fewer formalists, and accordingly defer to rules less and break more.