Elimination of the Potential Hazard of the Long March 4 Launch Vehicle's In-orbit Breakup

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CASC Eyes the Long March Vehicle's Reliability Improvement

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Flight Record of the Long March Series of Launch Vehicles

(Continued)The 71st Launch On October 15,2003,China's first manned spaceship,Shenzhou 5,was launched by a LM-2F launch vehicle.The first Chinese astronaut Yang Liwei stayed in space for 21 hours and landed back on the Earth safely on October 16。

Flight Record of the Long March Series of Launch Vehicles

(Continued) The 75th Launch On December 30, 2003, the LM-2C/SM launch vehicle launched theTance 1 (TC-1) satellite into orbit from the Xichang Satellite Launch Center. The satellite entered a super geosynchronous orbit . Launch Site: Xichang Satellite Launch Center Launch Result: Success At 03:06 Beijing time on December 30, the LM-2C/SM launch vehicle lifted off into space with TC-1 (equatorial satellite) and precisely sent the satellite into

Flight Record of the Long March Series of Launch Vehicles

(Continued)THE 67TH LAUNCHOn May 15, 2002, a LM-4B launch vehicle lifted off with FY-1D meteorological satellite and HY-1A oceanic satellite from Tai-yuan Satellite Launch Center and

Flight Record of the Long March Series of Launch Vehicles

(Continued) THE 59TH LAUNCH On November 20,1999,a LM-2F launch vehicle lifted off with China’s indigenous Shenzhou 1 experimental spaceship from Jiuquan Satellite Launch Center.Shenzhou 1 returned to Earth on November 21 after 21 hours of in-orbit operation and circling the Earth 14 times.

Flight Record of the Long March Series of Launch Vehicles

(Continued)THE 67TH LAUNCHOn May 15, 2002, a LM-4B launch vehicle lifted off with FY-1D meteorological satellite and HY-1A oceanic satellite from Tai-yuan Satellite Launch Center and

Long March Launch Vehicles Promote Quick and Sound Development of Satellite Applications

INTRODUCTION Launch vehicles are a precondition and main carrier for space activities for human beings.Their development have directly promoted the technology of satellite applications,manned spaceflight,deep space exploration,and promoted the development of communication,navigation,environmental monitoring,resource exploitation,scientific research and so on.

Research on Overall Optimization Technology of Long March 6A Launch Vehicle

On March 29,2022,the Long March 6A launch vehicle developed by the Shanghai Academy of Space-flight Technology successfully made its maiden flight at the Taiyuan Satellite Launch Center.The Long March 6A launch vehicle was China’s first solid bundled rocket.It uses non-toxic and non-polluting propellants,and has a 700 km sun-synchronous orbit carrying capacity of no less than 4.5 t,which is more than 50%higher than that of a LM-4C launch vehicle.During the development of the LM-6A launch vehicle,the matching relationship between systems and the overall performance of the entire rocket improved significantly through continuous overall optimization work.This paper introduces the typical overall optimization work during the development of the LM-6A launch vehicle.

Flight Record of the Long March Series of Launch Vehicles

(Continued) The 79th Launch On September 9, 2004, a LM-4B launch vehicle launched two satellites, SJ-6A and SJ-6B, into space both for space environment exploration from the Taiyuan Satellite Launch Center. The two satellites entered their preset sun synchronous orbits. Launch Site: Taiyuan Satellite Launch Center Launch Result: Success At 07:14 Beijing time on September 9, the LM-4B launch vehicle was launched into space with SJ-6A and SJ-6B on board.

Numerical analysis of dynamic response of vehicle–bridge coupled system on long-span continuous girder bridge

To systematically study the vehicle-bridge coupled dynamic response and its change rule with different parameters, a vehicle model with seven degrees of freedom was built and the total potential energy of vehicle space vibration system was deduced. Considering the stimulation of road roughness, the dynamic response equation of vehicle-bridge coupled system was established in accordance with the elastic system principle of total potential energy with stationary value and the ＂set-in-right-position＂ rule. On the basis of the self-compiled Fortran program and bridge engineering, the dynamic response of long- span continuous girder bridge under vehicle load was studied. This study also included the calculation of vehicle impact coefficient, evaluation of vibration comfort, and analysis of dynamic response parameters. Results show the impact coefficient changes with lane number and is larger than the value calculated by the ＂general code for design of highway bridges and culverts （China）＂. The Dieckmann index of bridge vibration is also related to lane number, and the vibration comfort evaluation is good in normal conditions. The relevant conclusions from parametric analyses have practical significance to dynamic design and daily operation of long-span continuous girder bridges in expressways. Safety and comfort are expected to improve significantly with further control of the vibration of vehicle-bridge system.

LSTM-DPPO based deep reinforcement learning controller for path following optimization of unmanned surface vehicle

To solve the path following control problem for unmanned surface vehicles(USVs),a control method based on deep reinforcement learning(DRL)with long short-term memory(LSTM)networks is proposed.A distributed proximal policy opti-mization(DPPO)algorithm,which is a modified actor-critic-based type of reinforcement learning algorithm,is adapted to improve the controller performance in repeated trials.The LSTM network structure is introduced to solve the strong temporal cor-relation USV control problem.In addition,a specially designed path dataset,including straight and curved paths,is established to simulate various sailing scenarios so that the reinforcement learning controller can obtain as much handling experience as possible.Extensive numerical simulation results demonstrate that the proposed method has better control performance under missions involving complex maneuvers than trained with limited scenarios and can potentially be applied in practice.

Improvement of heat-tolerance by training I. Evaluation of effects of long-distance running and march training on heat-tolerance

in order to verify the heat-tolerance effect, two trainings, 90 min marching with load (WBGT 24. 6～35.6℃) and 10 km running (WBGT 25.0～31.1℃) were performed in laboratory and field under hot climate.Ten to twelve times (days) of training were carried out

LSTM-based lane change prediction using Waymo open motion dataset: The role of vehicle operating space

Lane change prediction is critical for crash avoidance but challenging as it requires the understanding of the instantaneous driving environment.With cutting-edge artificial intelligence and sensing technologies,autonomous vehicles(AVs)are expected to have exceptional perception systems to capture instantaneously their driving environments for predicting lane changes.By exploring the Waymo open motion dataset,this study proposes a framework to explore autonomous driving data and investigate lane change behaviors.In the framework,this study develops a Long Short-Term Memory(LSTM)model to predict lane changing behaviors.The concept of Vehicle Operating Space(VOS)is introduced to quantify a vehicle's instantaneous driving environment as an important indicator used to predict vehicle lane changes.To examine the robustness of the model,a series of sensitivity analysis are conducted by varying the feature selection,prediction horizon,and training data balancing ratios.The test results show that including VOS into modeling can speed up the loss decay in the training process and lead to higher accuracy and recall for predicting lane-change behaviors.This study offers an example along with a methodological framework for transportation researchers to use emerging autonomous driving data to investigate driving behaviors and traffic environments.

Research on Optimizing the Construction of the Long March National Cultural Park from the Perspective of Cultural Route Heritage Protection

The idea of cultural route heritage protection expands the protection theory for world cultural heritage.The Long March route carries the prominent characteristic of cultural route heritage.By actively building the Long March National Cultural Park,China has strengthened the overall protection and integrated utilization of the Long March cultural heritage,upgraded the hardware facilities for exhibition,and investigated ways to protect cultural route heritage with Chinese characteristics.During the construction of the Park,it is necessary to draw on the concept and norms of the cultural route heritage protection,optimize the construction approach,and make the construction of the Park more in line with the linear cultural characteristics of Long March heritage.Specifically,it is proposed to improve the Long March cultural route heritage protection system oriented towards“authenticity”protection,to deeply tap and interpret the prominent universal worth of the Long March route,augmenting the international dissemination of the Long March culture in an innovative way,and realizing a more scientific and effective protection and utilization of Long March cultural resources.

An Analysis of the Festivals and Holidays Celebrated by the Red Army During the Long March

The Long March of the Chinese Workers’and Peasants’Red Army is hailed as the“Red Ribbon on the Earth.”The Long March was characterized by revolutionary heroism and,at the same time,was no lack of revolutionary romanticism.This arduous journey also presented two difficult questions:whether to celebrate festivals and holidays or not and whether to celebrate them simply or grandly.By exploring such trade-offs,we can appreciate a strong sense of national identity among the Red Army soldiers as idealists,grasp more historical details of the world-shattering Long March,and feel the resilience and greatness of the Chinese nation.

Long March Rockets Complete 2018 Missions with 37 Record-Setting Launches

A LM-2D/Yuanzheng 3 launch vehicle successfully launched 6 Yunhai 2 satellites and one test microsatellite named'Chongqing'into their preset orbits,concluding China’s final orbital launch of2018.The launch took place at 16:00 Beijing time on December 29,2018 from the Jiuquan Satellite Launch Center.

Long March 6A and Its Technical Characteristics

China’s first solid-liquid bundled launch vehicle,the Long March 6 A(LM-6 A)successfully adopted a number of key new technologies,launching the Pujiang 2 and Tiankun 2 satellites precisely into their predetermined orbits,thus demonstrating that China has mastered solid-liquid bundled launch vehicle technology and has a new member in the new generation launch vehicle family.For the first time in China,a booster adopted a 2 m-diameter solid motor and a 270 V,20 k W high-voltage and high-power electric servo system was used to control the swing of the solid motor nozzles.A health diagnosis system for the core first stage engine and unattended automation technology were also adopted for the first time.

高原铁路某特长隧道独头掘进通风技术分析

文章面向高原铁路特长隧道,开展通风技术研究,提出一种基于避车洞通风技术、人行通道通风技术的蓄风房通风策略。基于高原铁路特长隧道通风案例,研究了蓄风房技术。文中研究成果供我国高原铁路特长隧道建设单位、运营单位加以参考、借鉴,以保证特长隧道通风性能,满足相关制度、规范对高原铁路特长隧道的环境要求,并实现铁路通风的节能效果。

Scenario-based Optimal Real-time Charging Strategy of Electric Vehicles with Bayesian Long Short-term Memory Networks

Joint operation optimization for electric vehicles(EVs)and on-site or adjacent photovoltaic generation(PVG)are pivotal to maintaining the security and economics of the operation of the power system concerned.Conventional offline optimization algorithms lack real-time applicability due to uncertainties involved in the charging service of an EV charging station(EVCS).Firstly,an optimization model for real-time EV charging strategy is proposed to address these challenges,which accounts for environmental uncertainties of an EVCS,encompassing EV arrivals,charging demands,PVG outputs,and the electricity price.Then,a scenario-based two-stage optimization approach is formulated.The scenarios of the underlying uncertain environmental factors are generated by the Bayesian long short-term memory(B-LSTM)network.Finally,numerical results substantiate the efficacy of the proposed optimization approach,and demonstrate superior profitability compared with prevalent approaches.