降低火运延占费的可行性研究

现阶段钢铁企业微利运行,企业内部对标挖潜已到一定程度,很难有大的突破,开始将关注点转到的第三利润源——现代物流,而火运作为内陆钢铁企业的重要运输方式之一,但其厂内延占费是前期降本未触及的领域。某钢铁企业通过开发实用程序,解决了厂内火运装卸车精细管理盲区的问题,大幅度降低了延占费用,达到了为企业创效的目的。

913例抽动障碍患儿出生时间的干支运气规律探析

目的:探讨抽动障碍患儿出生时对应干支运气分布特点,研究抽动障碍的发生与出生时干支运气的相关性。方法:对913例抽动障碍患儿出生日期的干支运气各因素(包括岁运、司天在泉、主气客气)进行描述性统计,并采用卡方检验研究其分布情况,采用无序多因素的Logistic回归分析研究出生日期对应的干支运气与抽动障碍发生的关系。结果:抽动障碍的发生与出生时间所属的主运、客运、司天、客气有关联,在主运方面,五之运比较,出生于二之运(火运),抽动障碍发生的风险增高;在客运方面,与少火比较,出生于太水之时,抽动障碍发生的风险降低;在司天方面,与太阳寒水比较,出生于太阴湿土之时,抽动障碍发生的风险降低;在客气方面,与太阳寒水比较,出生于少阳相火之时抽动障碍发生的风险增高。结论:患儿出生时干支运气与抽动障碍的发生相关,火运、少阳相火为抽动障碍的危险因素,太阴湿土、太水是抽动障碍发生的保护因素。

Adaptive Super‑Twisting Sliding Mode Fault‑Tolerant Control of Launch Vehicles with Actuator Faults

A fault-tolerant control law based on adaptive super-twisting sliding mode control(SMC)is designed for the attitude command tracking problem of a launch vehicle with actuator faults,considering the uncertainties arising from unknown external disturbances,fuel consumption of the launch vehicle,and the perturbation due to the change in rotational inertia caused by tank sloshing,as well as the potential system model changes due to actuator fault and unmodeled dynamics.This control algorithm integrates the super-twisting SMC,the fuzzy logic control,and the adaptive control.First,a super-twisting sliding surface is selected to mitigate the“chattering”phenomenon inherent in SMC,ensuring that the system tracking error converges to zero within a finite time.Second,building upon this sliding surface,the fuzzy logic control is used to approximate the unknown system function,which includes fault information.Adaptive parameters are used to approach the system parameters and enhance disturbance rejection.The stability and finite-time convergence of the launch vehicle attitude tracking control system are verified by the Lyapunov method.Numerical simulations demonstrate the effectiveness and robustness of the proposed adaptive super-twisting SMC algorithm.

双W型车皮煤炭装载平整装置的研制与应用

铁路是煤炭运输的最主要方式,铁路技术的提高,火车的速度不断提升,其装载不平衡将造成偏载,存在安全隐患,因而结构简单、性能优良、安全实用的平煤设备显得必不可少。文章分析了现有平整装置的结构和弊端,根据需要对现在的平整装置进行了改良,满足了现有火车运输的需要,更能广泛的应用到其他干散物料的车皮内平整中。

Olympic torch relay abroad and its reflection on English teaching at home

What happened to the Olympic torch relay abroad reveals how little and superficially the western countries, in particular, know of china. Meanwhile there also exists a lack or vacancy of English teaching in English teaching at home. The failure of expressing Chinese culture and conditions correctly and fluently among the English learners has already resulted in negative impact on our international image, which is related to our teaching policy of strengthening western culture and neglecting the export of our own culture. Therefore, in the English teaching at all levels, great attention should be paid to the cross-cultural communication between home culture and the culture of target language, the promotion of expressing mother culture in foreign languages, and exporting and broadcasting Chinese culture.

Effects of Spark Ignition Engine Operating Parameters on Its Cyclic Variation ——Modeling and Simulation

An engine cyclic variation model has been built by using the residual gas temperature for the n th cycle as the input of the model, through constant pressure intake process, adiabatic compression process, constant volume combustion process, adiabatic expansion process, adiabatic blow down process and constant pressure exhaust process to approximate the thermodynamic processes in the cylinder, finally the residual gas temperature for the ( n+1) th cycle can be estimated. Because of the adding of engine operating parameters such as engine speed, spark advance, equivalence ratio, intake air pressure, intake air temperature to the model, effects of these parameters on cyclic variation can be estimated quantitatively. Since residual gas temperature fluctuation between cycles reflects the circumstances of engine cyclic variation, parameters to which residual gas temperature is sensitive are most likely used as the means to control cyclic variation. Model simulation shows that for the nearly stiochiometric mixture, cyclic variation is not obvious or even quite stable, but for the lean mixture, under the circumstances of partial load and larger spark advances, engine cyclic variations occur chaotically or with bifurcation.

FOUR-AXIS WIRE-EDM SIMULATION OF COMPLICATED MODELS

In the verification of wire electrical discharge machining （EDM）, the motion and the performance of the wire-EDM system are analyzed. The maximum inclining angle of the wire is calculated. The relevant judgment methods are used for the collision between the wire, the fixture, and the machining table. In the wire-EDM simulation, the generated solid model can he used to investigate programming results and to check the machining accuracy. The generation algorithm for the solid model in the simulation is solved based on Boolean operations. The wire swept volume for each cutting step is united to form the entire wire swept volume. Through Boolean subtraction between the stock model and the entire wire swept volume, the solid model in the wire-EDM simulation is generated. The method is also suitable for the wire path intersection occurred in cutting cone-shaped models. Finally, experiments are given to prove the method.

Sensitivity and effect of key operational parameters on performance of a dual-cylinder free-piston engine generator

The free-piston engine generator(FPEG)is regarded as the next generation of energy conversion system which may replace traditional engines in the future.The effect of key operational parameters like excess air ratio of input mixture and ignition position on the engine performance of a dual-cylinder FPEG was investigated,and their sensitivity was analyzed in this paper.The operating compression ratio of the system is susceptible to changes in excess air ratio and ignition position.At the same time,it decreases from 15.8 to 6.6 when excess air ratio increases from 0.85 to 1.15,but it increases from 6.1 to 13.3 as ignition position increases from 15 mm to 20 mm.The operating frequency and indicated power are more sensitive to changes in excess air ratio than ignition position.But it is the opposite for the indicated thermal efficiency and friction loss.Excess air ratio and ignition position have a quite similar influence on heat transfer.Therefore,from the perspective of system operation and performance,it is preferable to keep excess air coefficient slightly below 1.0.In contrast,when selecting ignition position,it is of great importance to comprehensively consider the risk of structural damage caused by the increase in the compression ratio and in-cylinder gas pressure.

Falcon Heavy

In these pages [1], the successful 2016 recovery of the first stage booster of a Falcon 9 rocket on a drone ship in the Atlantic Ocean was recounted. The goal was to recover the booster for reuse, to reduce cost for subsequent launches, and it was only the second time a Falcon 9 booster was successfully recovered. Video of the booster landing on the ship was striking and demonstrated that recovery was possible at convenient points other than the launch site where the first recovery was achieved.

Adaptive fault-tolerant control of heavy lift launch vehicle via differential algebraic observer

A novel adaptive fault-tolerant control scheme in the differential algebraic framework was proposed for attitude control of a heavy lift launch vehicle （HLLV）. By using purely mathematical transformations, the decoupled input-output representations of HLLV were derived, rendering three decoupled second-order systems, i.e., pitch, yaw and roll channels. Based on a new type of numerical differentiator, a differential algebraic observer （DAO） was proposed for estimating the system states and the generalized disturbances, including various disturbances and additive fault torques. Driven by DAOs, three improved proportional-integral- differential （PID） controllers with disturbance compensation were designed for pitch, yaw and roll control. All signals in the closed-loop system were guaranteed to be ultimately uniformly bounded by utilization of Lyapunov＇s indirect method. The convincing numerical simulations indicate that the proposed control scheme is successful in achieving high performance in the presence of parametric perturbations, external disturbances, noisy corruptions, and actuator faults.

Dynamic model for internally carried air-launched rocket

For rigid-flexible coupling multi-body with variable topology,such as the system of internally carried air-launched or heavy cargo airdrop,in order to construct a dynamic model with unified form,avoid redundancy in the modeling process and make the solution independent,a method based on the equivalent rigidization model was proposed.It divides a system into independent subsystems by cutting off the joints,of which types are changed with the operation process of the system.And models of different subsystems can be constructed via selecting suitable modeling methods.Subsystem models with flexible bodies are on the basis of the equivalent rigidization model which replaces the flexible bodies with the virtual rigid bodies.And the solution for sanction,which is based on the constraints force algorithm(CFA)and vector mechanics,can be independent on the state equations.The internally carried air-launched system was taken as an example for verifying validity and feasibility of the method and theory.The dynamic model of aircraft-rocket-parachute system in the entire phase was constructed.Comparing the modeling method with the others,the modeling process was programmed;and form of the model is unified and simple.The model,method and theory can be used to analyze other similar systems such as heavy cargo airdrop system and capsule parachute recovery system.

The Research on Key Technologies of Chinese Heavy-Lift Launch Vehicle Control System

This paper reviewed the development of control technology in domestic and foreign launch vehicle(LV), and based on which, the key technologies of control system for Chinese heavy-lift launch vehicles were proposed. A dynamic on-line trajectory planning technique was discussed to meet the demand of guidance control under complex constraints, and model based identification and adaptive control technology was suggested to deal with the control problems caused by model uncertainty and disturbance, and an integrated avionics system based on high speed communication was put forward for module integration and distributed control, and FBG based real time flight control was also discussed. Moreover, other key technologies, such as wireless interconnection, wireless power transfer, and temporal and spatial partitioning operating system, are both briefly introduced for the application in control systems. These studies will lead to breakthroughs in autonomous flight control in LV, and provide technical support for more long-term deep space explorations.

Innovation and Outlook of the New Generation of Cryogenic and Quick-Launch Launch Vehicle

This paper introduces a launch vehicle scheme for the new generation of cryogenic and quick-launch launch vehicle(LM-6). The main technical innovations of LM-6 launch vehicle include the capability of twenty satellites launched by one vehicle, high-pressure staged combustion cycle engine and oxygen tank self-pressurization, sandwich bulkhead tank with 200 K temperature difference, and 7-day quick-launch using the "three horizontals" test and launch mode with integral transportation and erection. The future development of the quick-launch launch vehicle is predicted based upon the need for vehicle mission coverage improvement, better response speed, and stronger market competiveness.

TORCH RELAY:Love Is Passing on

May is not an ordinary month for the whole China,as the 8.0-magnitude earthquake hit southwest of China and shocked the whole nation.And now,the torch relay in China is endowed with more responsibility and significance:to pass

Maiden Flight of Long March 7--The New Generation Medium Launch Vehicle in China

On June 25, 2016, the Long March 7(LM-7) launch vehicle completed its maiden flight successfully. LM-7, as a new generation of medium and basic launch vehicle based on the design concepts of non-toxic and nonpolluting, was developed for the purpose of launching a cargo spacecraft to the Chinese space station. Based on the experience on launching cargo spacecraft and satellites, LM-7 can be adapted for mainstream satellite launch missions in the future with its characteristics of serialization and continuous optimization. LM-7 is expected to be used to launch manned spacecraft in the future. This paper presents a general review of LM-7 with regard to the general scheme and provides references for the development prospects of a medium launch vehicle series in China.

Low Cost and Reusability of Launch Vehicle

This paper analyzes the launch price of the launch vehicles, domestic and abroad, studies the status and trend of the low cost launch vehicles, and introduces two measures to reduce the cost by means of evolved and disruptive technologies, utilizing the concept of low cost manufacturing and operating modes as well. This paper also analyzes the launch strategies for small satellites such as piggyback, networking launch, and single launch with a small launch vehicle(SLV). Finally, the development trend of reusable launch vehicles is discussed as well as the development prospects for China's reusable launch vehicle.

A Control Simulation Method of High-Speed Trains on Railway Network with Irregular Influence

Based on the discrete time method, an effective movement control model is designed for a group of high- speed trains on a rail network. The purpose of the model is to investigate the specific traffic characteristics of high-speed trains under the interruption of stochastic irregular events. In the model, the high-speed rail traffic system is supposed to be equipped with the moving-block signalling system to guarantee maximum traversing capacity of the railway. To keep the safety of trains＇ movements, some operational strategies are proposed to control the movements of trains in the model, including traction operation, braking operation, and entering-station operation. The numerical simulations show that the designed model can well describe the movements of high-speed trains on the rail network. The research results can provide the useful information not only for investigating the propagation features of relevant delays under the irregular disturbance but also for rerouting and reseheduling trains on the rail network.

Looking Back and Prospecting to the Project Design of the Spaceflight Launching Site in China

The development history of the project design of spaceflight launching site in China and the main forms used in these designs were introduced in this thesis, and it was pointed out that the spaceflight launch should not use only one fixed model. According to its nation condition, China should design and build the launching project facility and device which correspond to the technology development of spacecraft and carrier rocket.

Technology and Market Prospect Analysis of Low Cost Small-lift Launch Vehicles for Small Satellites

The technological development status of new generation low cost small-lift launch vehicles applied to small satellite launch is investigated in this paper. The development trends are summarized, including low cost and rapid response capability, utilization of mature rocket and missile technology, the development of mobile launch technology adopting air-based platforms and use of innovative technology. Moreover, the external power and internal demand of the small-lift launch vehicle are analyzed and the market prospect is forecasted. Finally, proposals for the development of small-lift launch vehicles are put forward, including exploration of the potential of existing rocket and missile technology, development of multi-platform mobile launch technology and further application of innovative technology and ideas.

Study on conditions of internally carried air-launched launch vehicles based on the virtual prototype technology

A method based on the virtual prototype technology simulating the separation of a launch vehicle from its aircraft in the aircraft wake was proposed based on the internally carried air-launched launch vehicle program.In this method,the full-scale model of the aircraft,the vehicle and the parachute are constructed.Then,they are imported into the ADAMS software,constraint solutions and driving forces are then added for visual dynamic simulation.The unsteady aerodynamic forces of the vehicle in the aircraft wake are calculated by CFD and the moving grid technique.The forces generated by the parachute can be derived from the Kirchhoff motion equation.Through comparing and analyzing the simulation results under different launch conditions,it has been proven that this method simulates the separation of a launch vehicle from the aircraft in the aircraft wake accurately.It provides the foundation for the aggregate project of internally carried air-launch vehicles,and offers a new referenced method for multi-body dynamic simulation.