空动作徒手训练大有裨益

为了解决新训驾驶员开头难的问题,踢好驾驶训练“头三脚”,我们在总结过去空动作徒手练习的基础上,结合基地化、规范化训练的要求,建立一套起步、停车、加减档综合空动作训练动作,经推行后,效果很好。 所谓空动作徒手练习,就是在新训驾驶员上车之前,或登车操作之中进行的离车徒手训练。在进行空动作徒手训练之前,我们把起步、停车、加减档操作编成形象、易记的口诀,让学兵按照正规操作要领反复训练,并采取一边念口诀,一边徒手操作的方法。

防PT回路空开误动作问题分析及可视化报警装置硬件设计

随着电网建设的不断深入,电力设备的运行也随着设备老化或工作人员的不规范操作出现了一系列的问题,电压互感器回路空开误动作是不可忽视的一个问题,空开误动作可能会导致线路和保护装置出现失压运行状况。本文首先分析了空开误动作的原因和空开误动作给电力系统带来的影响,并在此基础上提出了一种防止空开误动作的可视化报警装置的硬件设计,通过加装报警指示灯和蜂鸣器模块,能够在空开误动作工况下保证同时发出声光报警信号,能够有效保证电力设备和电力系统的安全稳定运行。

九月初段潜在回调风险

市场可操作区间判定的大致标准一般结构末端,虽是潜在风险,但结构未完成前,都不应作主动抛空动作。可操作性与不可操作性的判定,通常以指数是否处于8日线之上为大致的参照标准:1、在该上之上时,市场无明显做空动能时,大结构末端处尚可短线以形态较好的补涨股为操作目标,当然目标股的流动性必需要考虑;2、股指处于8日线之下时,通常判定为不可操作区,此时操作上应转为守势,若不是有十足的把握,对于普通操作水平不高的人而言,最好是减仓收手观望。

这辆切诺基冷风风向为何失控

一辆北京切诺基吉普车,怠速运行时,空调系统完全正常。当车处于行驶状态时,也无明显异常情况。但当该车时速达到70km/h时,空调出风口不能正常出风。

体操空翻类动作生物力学分析的研究现状及发展改进

通过查阅大量的国内、外文献资料，针对体操中空翻转体动作的生物力学原理及作用进行研究，对旨在了解空翻转体类动作给竞技体操带来的观赏性、价值性，并对前人的研究结果进行归纳与分析。在此基础上，探讨了该领域研究中存在的不足，并提出了相应的建议。

A stability study of goaf based on mechanical properties degradation of rock caused by rheological and disturbing loads

Based on the classical static theory and static numerical simulation,the static method could not accurately reflect the stability of goaf where the rocks on the pillar and roof are influenced by Theological and blasting disturbance for a long time.According to the test from the site,an experimental study was made in Theological and dynamic disturbance.After that,on the basis of variable rock mechanics parameters from the experimental data,numerical simulation was used to analyze the vertical stress distribution of goaf,vertical displacement and plastic area of roof in the "deterioration" caused by Theological and blasting,which shows that the mechanics properties of the rock were greatly influenced by Theological,and dynamic disturbance.The results of the experimental study and numerical simulation show that the mechanics properties of rock are greatly influenced by Theological and dynamic disturbance.As a result,the stability of goaf is greatly reduced.Finally,by comparing golf monitoring results with the analysis of theoretical calculation,it was found that the results were approximately the same,which testifies the reliability of the method.This method provides a new way of studying the stability of goaf as well as laying a basic foundation for future safety management.

Investigating the flow characteristics of air-lift pumps operating in gas-liquid two-phase flow

Experiments were conducted to investigate the flow characteristics in the riser pipe and the suction pipe of airlift pump at a series of air flow rates and submergence ratios by using a high speed camcorder and a Laser Doppler Velocimetvy system （LDV）. A modified model was developed to predict the performance of airlift pump operating in gas-liquid two-phase flow, The results show that an unstable flow structure composed by a water falling film, a bubbly mixture, a water ascending film appearing alternately in riser pipe dominates the performance of airlift pump at large air flow rates. The bubbly mixture with a strongest capacity for pumping water first increases to its maximum and then slightly decreases. In suction pipe, the average velocity shows a flat profile and increases with increasing submergence ratio. Moreover, the predicted results of modified model are in good agreement with the experimental data in a margin of ± 12%.

Practice of Project Management Methodology for Commercial Aero engines Based on Integrative Project Architectures

To collect and share information of projects or products and make it consistent and correct so that the quality and costs of projects can be effectively controlled,an integrative project architecture integrating different types of breakdown structures is necessary.In this paper,the international research status on work breakdown structure(WBS)was analyzed,and an integrative project architecture for commercial aero-engines was designed,where product breakdown structure(PBS),WBS,organization breakdown structure(OBS)and cost breakdown structure(CBS)were integrated and built.And the architecture was applied in information systems.A transfer from technological views of complex products through their lifecycles to management views has been realized with this standardized architecture,thus development tasks and costs can be controlled.

Development of an ε-type actuator for enhancing high-speed electro-pneumatic ejector valve performance

A novel ε-type solenoid actuator is proposed to improve the dynamic response of electro-pneumatic ejector valves by reducing moving mass weight. A finite element analysis (FEA) model has been developed to describe the static and dynamic operations of the valves. Compared with a conventional E-type actuator, the proposed ε-type actuator reduced the moving mass weight by almost 65% without significant loss of solenoid force, and reduced the response time (RT) typically by 20%. Prototype valves were designed and fabricated based on the proposed ε-type actuator model. An experimental setup was also established to investigate the dynamic characteristics of valves. The experimental results of the dynamics of valves agreed well with simulations, indicating the validity of the FEA model.

Geopoetical Analysis of Livonia During The Great Northern War Based on The Last Novik A Historical Novel by Ivan Lazhechnikov

The term geopoetics has a wide interpretation. It is defined as a project of the cultural activity aimed at creating and changing territorial myths and research path, which considers the interaction between literary creativity and geographical space. Defining this term, it is possible to introduce a geopoetical analysis diagram based on three interconnected positions： the writer＇s personality, the universe of an artwork and its characters. The Last Novik--A historical novel by Lazhechnikov analysis example presented on a diagram reveals the relationship between time and space in the literary work, as well as the author＇s interaction with the described events.

The Creation of Public Nature in Community Public Space Design

The rational design of urban public space has more and more attention of the community; in the end, people need public spaces of an active exploration and attempt. Through human experience of urban public space, the design of public space in the city questioned the rationality, emphasized the human behavior activities on public space design requirements, and emphasized the place of people, human behavior activities, and the activities of the Trinity design ideas. By comparing the two public spaces Analysis of Chongqing, it further emphasized the left of human activity, human stories and spirit; public space has lost its significance.

女子体操中的跳跃预先后摆的教学法

随着我国社会主义事业飞跃的发展,我国的体操运动已經有了飞速度的发展,但是与国际水平相比还有一段距离,在大跃进的形势下,这个距离已日益趋近,我們要大大地进行体育技术革新,改变过去的面貌使在我国拥現出大批等級运动員和运动健将。根据一九五八年三月,八月的健将級規定动作測驗以及一九五八年八月的一級运动員测驗,約有80％的女运动員在做跳跃中不能滿意的完成动作,特別是一些难度較高要求再預先后摆的动作,都往往失敗了,大部分練习者失敗的原因是沒有正确的掌握踏跳和第一騰空以及預先后摆动作的要領,这固然与女子生理特点有关,如女子腿部和臂部力量小,骨盆重,上体長而下肢短,使整个身体的重心显得低。

Derivation of Varying Specific Heat Gasdynamic Functions,Normal Shock Analytical Solution and its Improvements

A set of new gasdynamic functions with varying specific heat are derived for the first time.An original analytical solution of normal shock waves is worked out therewith.This solution is thereafter further improved by not involving total temperature.Illustrative examples of comparison are given,including also some approximate solutions to show the orders of their errors.

Optimization of Root Section for Ultra-long Steam Turbine Rotor Blade

This study presents the comparison of aerodynamic performances of two successive designs of the root profiles for the ultra-long rotor blade equipped with a straight fir-tree dovetail. Since aerodynamic and strength requirements laid upon the root section design are contradictory, it is necessary to aerodynamically optimize the design within the limits given by the foremost strength requirements. The most limiting criterion of the static strength is the size of the blade cross-section, which is determined by the number of blades in a rotor and also by the shape and size of a blade dovetail. The aerodynamic design requires mainly the zero incidence angle at the inlet of a profile and in the ideal case ensures that the load does not exceed a limit load condition. Moreover, the typical root profile cascades are transonic with supersonic exit Math number, therefore, the shape of a suction side and a trailing edge has to respect transonic expansion of a working gas. In this paper, the two variants of root section profile cascades are compared and the aerodynamic qualities of both variants are verified using CFD simulation and two mutually independent experimental methods of measurements （optical and pneumatic）.

Numerical Analysis of Shock Induced Separation Delay by Air Humidity

In this paper numerical calculations of the dry and humid air flows in the nozzle are presented. The dry air flow (adiabatic flow) and the humid air flow (flow with homogeneous condensation, diabatic flow) are modeled with the use of Reynolds Averaged Navier-Stokes (RANS) equations. The comparison of these two types of flow is carried out. The influence of the air humidity on the shock wave location and its interaction with the boundary layer is examined. Obtained numerical results present a first numerical approach of the condensation and evaporation process in transonic flow of humid air. The phenomena considered here are very complex and complicated and need further in-depth numerical analysis.

Bifurcation analysis for vibrations of a turbine blade excited by air flows

A reduced three-degree-of-freedom model simulating the fluid-structure interactions （FSI） of the turbine blades and the on- coming air flows is proposed. The equations of motions consist of the coupling of bending and torsion of a blade as well as a van der Pol oscillation which represents the time-varying of the fluid. The 1：1 internal resonance of the system is analyzed with the multiple scale method, and the modulation equations are derived. The two-parameter bifurcation diagrams are computed. The effects of the system parameters, including the detuning parameter and the reduced frequency, on responses of the struc- ture and fluid are investigated. Bifurcation curves are computed and the stability is determined by examining the eigenvalues of the Jacobian matrix. The results indicate that rich dynamic phenomena of the steady-state solutions including the sad- dle-node and Hopf bifurcations can occur under certain parameter conditions. The parameter region where the unstable solu- tions occur should be avoided to keep the safe operation of the blades. The analytical solutions are verified by the direct nu- merical simulations.

Numerical simulation of aerodynamic interactions among helicopter rotor,fuselage,engine and body of revolution

Numerical simulations of helicopter aerodynamic interactions among the main rotor,fuselage,engine inlets/outlets and slung loads of specific geometries have been conducted by very few researchers.In this work,the steady-state compressible Reynolds-averaged navier-stokes equations are solved to study the aerodynamic interactions among helicopter rotor,fuselage,engine and body of revolution in three cases,namely MI-171V5,ROBIN and UH-60A.In the first case,the downwash flow provided by the rotor of the uniform actuator disc model induces a significant deflection of the airflow velocity.The vortex-shaped distribution and evolution are discussed in detail.The engine can effectively change the overall flow field.The asymmetry of the flow field is observed by using the non-uniform actuator disc model.Qualitative analysis of ROBIN and quantitative computation of UH-60A show a consistent accuracy of the rotating reference frame model for rotor.The blade tip vortex motion of UH-60A is simulated and its radial position prediction is compared to empirical formulas.While performing flow of UH-60A in hover,both the fuselage normal force and rotor lift decrease because of the impact of the body of revolution.

Fermion superfluid with hybridized s-and p-wave pairings

Ever since the pioneering work of Bardeen, Cooper and Schrieffer in the 1950 s, exploring novel pairing mechanisms for fermion superfluids has become one of the central tasks in modern physics. Here, we investigate a new type of fermion superfluid with hybridized s-and p-wave pairings in an ultracold spin-1/2 Fermi gas. Its occurrence is facilitated by the co-existence of comparable s-and p-wave interactions, which is realizable in a two-component 40 K Fermi gas with close-by s-and p-wave Feshbach resonances. The hybridized superfluid state is stable over a considerable parameter region on the phase diagram, and can lead to intriguing patterns of spin densities and pairing fields in momentum space. In particular, it can induce a phase-locked p-wave pairing in the fermion species that has no p-wave interactions. The hybridized nature of this novel superfluid can also be confirmed by measuring the s-and p-wave contacts, which can be extracted from the high-momentum tail of the momentum distribution of each spin component. These results enrich our knowledge of pairing superfluidity in Fermi systems, and open the avenue for achieving novel fermion superfluids with multiple partial-wave scatterings in cold atomic gases.

Equivalent Stiffness of the Saturated Poro-elastic Half Space Interacting with an Infinite Beam to Harmonic Moving Loads

The expression of the equivalent stiffness of the saturated poro-elastic half space interacting with an infinite beam to harmonic moving loads is obtained via the Fourier transformation method in the frequency wave number domain. Based on the obtained equivalent stiffness, the frequency wave number domain solution of the beam-half-space system is obtained by the compatibility condition between the beam and the half space. Critical velocity of harmonic moving loads along an infinite Euler-Bernoulli elastic beam is determined. The time domain solutions for the beam and the saturated poro-elastic half space are derived by means of the inverse Fourier transformation method. Also, the influences of the load speed, frequency and material parameters of the poro-elastic half space on the responses of the beam are investigated. Numerical results show that the frequency corresponding to the maximum deflection and bending moment increases with increasing load speed. Moreover, it can be seen that at higher frequencies, the dynamic response is independent of the load speed. The present results also show that for a beam overlying a saturated poro-elastic half space, there still exist critical velocities even when the load velocity is larger than the shear wave speed of the medium.