白肋烟香气物质的积累与调制条件的关系

对在生长及不同晾制条件下调制的白肋烟烟叶中的21种主要香气物质的含量进行了测定、分析,研究了不同调制条件对香气物质含量的变化规律的影响,实验结果表明:香气物质的含量在白肋烟的生长、调制过程中始终处于动态变化;大部分香气物质在生长期间逐步累积,在调制期间急剧增加,在调制末期趋于平稳;上部、中部白肋烟叶在调制过程中,香气物质的积累较为明显,下部烟叶稍差;吡啶类、酮类、醇类等化合物及香气物质总量均在变黄-变褐期达峰值;不同调制条件对香气物质含量的变化规律存在影响,但对香气物质的积累无明显的优势;科研晾房的白肋烟烟叶采用中湿处理有利于白肋烟特征香气物质的积累.

成熟度和调制时间耦合对烤烟内在品质的影响

运用模糊数学方法评价了成熟度和调制时间耦合条件下烤烟的内在品质,分析了成熟度和调制时间对烤后烟叶品质的影响.结果表明,延长变黄期的调制时间12 h或延长定色期的调制时间12 h可以提高下部烤烟内在品质;延长变黄期和定色期的调制时间各12 h有利于中部过熟烟叶内在品质的形成;延长变黄期和定色期的调制时间各12 h有利于提高上部欠熟烟叶的内在品质.成熟度及调制时间对不同部位烟叶内在品质的影响不同,针对不同成熟度不同部位的烟叶实施不同的调制时间,可以进一步改善烤烟的内在品质.

可重构无线智能电表的自动化调制通信系统

在智能电网建设工程中,电能表承担着复杂的数据计量与通信互动任务,因此其对于通信数据的调制与处理能力直接决定了配电网环境的信息传输稳定性,基于此设计面向可重构无线智能电表的自动化调制通信系统。以主控制器电路作为核心电量调配元件,按需连接驱动继电器芯片与通信信号调制模块,完成系统的硬件执行环境搭建。在此基础上,设计可重构型无线通信程序,通过设置智能电表的冗余调制条件的方式,计算通信调制时延量的具体数值,完成系统的软件执行环境搭建,结合相关硬件设备结构体,实现可重构无线智能电表自动化调制通信系统的顺利应用。对比实验结果表明,与ZigBee型通信系统相比,自动化调制通信系统能够按照数据任务的计量与互动需求,为其分配可靠的信息传输通道,满足稳定配网电表信息传输稳定性的实际应用需求。

异核两组分玻色-爱因斯坦凝聚体中暗孤子的形成及其性质

数值模拟准一维异核两组分玻色-爱因斯坦凝聚体在谐振子势阱中的运动,研究调制不稳定性条件(MI条件)下暗孤子的形成及其性质.在调制不稳定性条件下,凝聚体基态形成后,瞬间使组分间的相互排斥力变为相互吸引力,实时演化可以形成暗孤子.对各组分自身相互作用系数分析发现,它们之间满足一定关系时暗孤子在不同的组分内形成,而且形成的暗孤子在谐振子势阱中呈现周期性的往返对穿运动.讨论了形成暗孤子数目与两种粒子的质量比率和粒子数比率存在的关系.

Effect of the computer fuzzy control on coal seam injection

To enhance the technology and efficiency of strata injection is a problem to be solved urgently. Because of effected by the rough and poor production conditions of mining and the changeable bearing condition of strata, the technological process of injection can not be controlled automatically.The fuzzy controlling technology of the coal strata injection is applied. This is the good way to ensure the effectiveness and efficiency of coal strata injection and to solve the current problems of production and safety in mining industry.

Ferroresonance at Open Phase Operating Conditions of Power Transformers

The reliability of electric supply to consumers is one of the most important factors that determine the requirements imposed on modem utility companies. This paper presents the results of investigation by computer software of the overvoltages resulting from a ferroresonance conditions in MV networks at open phase operating condition with and without connection to earth on source and load sides of distribution transformer. This overvoltage may reach 4.2 pu on one of the HV side of transformer unswitched phases. The results of the study show that ferroresonance overvoltage may be controlled by replacing fuses with circuit breakers on HV side to ensure switching-off all phases. Insertion of resistor or reactor in the neutral of source and loadsides of the transformer with 5% active load will help in suppressing overvoltages.

Pressure fluctuation propagation of a pump turbine at pump mode under low head condition

Pressure fluctuation at the vaneless space and vanes passages is one of the most important problems for the stable operation of a pump turbine. The fluctuation appears in any operating condition. Much research has been done on the pressure fluctuation of hydraulic machinery. However, the details of pressure fluctuation propagation of the pump turbine at the pump mode have not been revealed. The modem pump turbine with high water head requires the runner to be ＂flat＂, which would induce pressure fluctuation more easily than the low head pump turbine. In this article, a high head pump turbine model is used as the re- search object. As the pressure fluctuation at off-design point is more serious than at the design point, the low head condition is chosen as the research condition. Pressure fluctuation at the vaneless space and vanes passages is predicted by the computa- tional fluid dynamics method based on k-co shear stress transport model. The experiment conducted on the test rig of the Har- bin Institute of Large Electrical Machinery is used to verify the simulation method. It proves that the numerical method is a feasible way to research the fluctuation under this operating condition. The pressure fluctuation along the passage direction is analyzed at time and frequency domains. It is affected mainly by the interaction between the runner and vanes. In the circumferential direction, the influence of the special stay vane on the pressure fluctuation is got. The amplitude in the high-pressure side passage of that vane is lower than that in the other side. The study provides a basic understanding of the pressure fluctua- tion of a pump turbine and could be used as a reference to improve the operation stability of it.

Specially shaped Bessel-like self-accelerating beams along predesigned trajectories

Over the past several years, spatially shaped self-accelerating beams along different trajectories have been studied extensively. Due to their useful properties such as resistance to diffraction, self-healing, and selfbending even in free space, these beams have attracted great attention with many proposed applications. Interestingly, some of these beams could be designed with controllable spatial profiles and thus propagate along various desired trajectories such as parabolic, snake-like, hyperbolic, hyperbolic secant, three-dimensional spiraling, and even self-propelling trajectories. Experimentally, suchbeams are realized typically by using a spatial light modulator so as to imprint a desired phase distribution on a Gaussian-like input wave front propagating under paraxial or nonparaxial conditions. In this paper, we provide a brief overview of our recent work on specially shaped self-accelerating beams, including Bessel-like, breathing Bessellike, and vortex Bessel-like beams. In addition, we propose and demonstrate a new type of dynamical Bessel-like beams that can exhibit not only self-accelerating but also self-propelling during propagation. Both theoretical and experimental results are presented along with a brief discussion of potential applications.

A New Plan and Coordination Strategy for Robot System Based on State Space

This paper proposes a general plan and coordination strategy for robot system. The state space for robot system is constructed according to the task requirement and system characteristic. Reachable state of the system is figured out by the system’s internal and external constraints. Task plan and coordination are then transformed as trajectory solving problem in the state space, by which the realizable conditions for the given task are discussed. If the task is realizable, the optimal strategy for task execution could be investigated and obtained in state space. Otherwise, it could be transformed to be realizable via adjusting the system configuration and/or task constraint, and the transformation condition could also be determined. This contributes to design, plan, and coordination of the robotic tasks. Experiments of the manipulator path planning and multi-robot formation movement are conducted to show the validity and generalization of the proposed method.

Study of TiO_2 thin films on Si substrate by the photoacoustic elastic bending method

The quantitative photoacoustic investigation of different TiO2 thin films on Si substrates is presented using the elastic bending method. Photoacoustic signal amplitude and phase spectra versus modulation frequency were measured and analyzed using different sample thicknesses. Within the proposed method particular attention is given to the analysis of optical, thermal, elastic and structural sample parameters. Considerable focus is devoted to the fitting procedure of experimental results using the two-layer sample theoretical model. Characteristics of previously developed photoacoustic apparatus are discussed, attempting to search the ideal experimental conditions which can provide a good signal-to-noise ratio and sensitivity.