Dynamical Properties of the Field Phase in the Jaynes-Cummings Model

Abstract

Phase properties of a coherent field interacting with a two-level atom in an ideal cavity are studied using the new hermitian phase formalism of Pegg and Barnett. It is shown in particular that phase properties of the field reflect the collapse and revival phenomena. The effects of finite detuning and atomic coherences are treated. The results for the variance of the phase cosine are obtained and compared with those based on earlier approaches.     

A novel inverse modeling control for piezo positioning stage

Journal of Mechanical Science and Technology - This paper focuses on the application of a novel inverse nonlinear autoregressive with exogenous input (NARX) structure and a fuzzy inference system...     

Chromium(III) compounds as catalysts for Hydrocarbon Oxidation and hydroperoxide decomposition

Chromium stearate and chromium acetylacetonate are very active catalysts both for the oxidation of hydrocarbons by molecular oxygen and for the decomposition of organic hydroperoxides. During these reactions they also catalyze the oxidation of secondary alcohols to the corresponding ketones by organic hydroperoxides. From organic hydroperoxides and chromium(III)compounds chromium (VI) compounds are formed which are probably the effective agents oxidizing secondary alcohols to ketones.     

Polyacrylonitrile‐carbon Nanotube‐polyacrylonitrile: A Versatile Robust Platform for Flexible Multifunctional Electronic Devices in Medical Applications

Flexible multifunctional electronic devices are of high interest for a wide range of applications including thermal therapy and respiratory devices in medical treatment, safety equipment, and structural health monitoring systems. This paper reports a scalable and efficient strategy of manufacturing a polyacrylonitrile‐carbon nanotube‐polyacrylonitrile (PAN‐CNT‐PAN) robust flexible platform for multifunctional electronic devices including flexible heaters, temperature sensors, and flexible thermal flow sensors. The key advantages of this platform include low cost, porosity, mechanical robustness, and electrical stability under mechanical bending, enabling the development of fast‐response flexible heaters with a response time of ≈1.5 s and relaxation time of ≈1.7 s. The temperature‐sensing functionality is also investigated with a range of temperature coefficient of resistances from ?650 to ?900 ppm K^?1. A flexible hot‐film sensing concept is successfully demonstrated using PAN‐CNT‐PAN with a high sensitivity of 340 mV (m s^?1)^?1. The sensitivity enhancement of 50% W^?1 is also observed with increasing supply power. The low cost, porosity, versatile, and robust properties of the proposed platform will enable the development of multifunctional electronic devices for numerous applications such as flexible thermal management, temperature stabilization in industrial processing, temperature sensing, and flexible/wearable devices for human healthcare applications.     

Optimization of the dye-sensitized solar cell performance by mechanical compression

In this study, the P25 titanium dioxide (TiO₂) nanoparticle (NP) thin film was coated on the fluorine-doped tin oxide (FTO) glass substrate by a doctor blade method. The film then compressed mechanically to be the photoanode of dye-sensitized solar cells (DSSCs). Various compression pressures on TiO₂ NP film were tested to optimize the performance of DSSCs. The mechanical compression reduces TiO₂ inter-particle distance improving the electron transport efficiency. The UV–vis spectrophotometer and electrochemical impedance spectroscopy (EIS) were employed to quantify the light-harvesting efficiency and the charge transport impedance at various interfaces in DSSC, respectively. The incident photon-to-current conversion efficiency was also monitored. The results show that when the DSSC fabricated by the TiO₂ NP thin film compressed at pressure of 279 kg/cm², the minimum resistance of 9.38 Ω at dye/TiO₂ NP/electrolyte interfaces, the maximum short-circuit photocurrent density of 15.11 mA/cm², and the photoelectric conversion efficiency of 5.94% were observed. Compared to the DSSC fabricated by the non-compression of TiO₂ NP thin film, the overall conversion efficiency is improved over 19.5%. The study proves that under suitable compression pressure the performance of DSSC can be optimized.     

试论石油天然气站场总图设计的矛盾特征

总图设计的任务是综合考虑工厂性质、规模、生产特点,满足运输和动力供应等要求,并结合当地条件,妥善处理厂区与厂外的关系,合理布置建(构)筑物、堆场、运输及动力设施等,全面地解决其间的协调问题,使建筑群体获得相应的艺术效果,以体现工厂建设的计划性、合理性、整体性,同时创造良好舒适的劳动、工作环境.