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1.
For China,at the turn of the century,how to keep the position of the space power,how to stimulate the enthusiasm of the space technicians and how to keep pace with the world space technology,all of these questions lie ahead of the Chinese people.So we may say China's space industry now is in the key stage.If the space industry draws great attention from the central government and the people of the country,it will have a brilliant future in the 21st century.We should put our eyes on the 21st century and prepare to explore space resources.It is difficult for us to keep pace with the times if we do not explore space resources and try to earn "the money in space".  相似文献   

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The exact cause of the accidenton March 22 when a launch ofAussat B-1 was attempted has beenfound out.Minute aluminium par-ticles in a control contact of the fir-ing circuit of the LM-2E have beenblamed for the unsuccessful launch.  相似文献   

3.
Wassersug R 《Space Policy》1994,10(3):199-206
This essay explores the pros and cons of maximizing the number of species that can be maintained on the Space Station. It reviews some of the history of comparative space biology to show that different cultures have different perspectives on the study of non-traditional research organisms (ie non-rodents) in space. Despite these differences, there are simple principles that all international partners in the Space Station endeavour should be able to uphold when deciding what facilities to build and what species to fly. As an argument for maximizing the taxonomic diversity on the Space Station, examples are given to show how very similar organisms may have different reactions to microgravity. At the same time the political pressure in the USA to make the Space Station an institution specifically servicing the 'health, well-being and economic benefits of people on earth', is acknowledged. Ultimately the justification for what species will be on the Space Station should rest with the quality of the scientific questions being asked.  相似文献   

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In this article, Mr. Liu Shen, principal senior engineer, directorate general of Telecommunications, Ministry of Post and Telecommunications, briefly introduces the developments and applications of China's satellite communications , including domestic and international satellite communications.  相似文献   

6.
The Chinese Academy of SpaceTechnology (CAST),officiallyfounded on Feb.20,1968,has ahistory of 25 years.Now it is aworld-famous space organizationwith a considerable size.CAST has14 research institutes and factoriesall over the country with more than11 thousand staff and workers in-cluding over 6000 technicians(about 1700 high and middle ranktechnical experts).Now it is spe-cialized in many areas,such asspacecraft system,structure,thermal control,attitude control,orbit control,electronics telemetry,  相似文献   

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In the early 1960s,with the ad-vent of the space era,it was quick-ly recognized that any object inspace was at risk due to the naturalmeteoroid environment.In the late1960s,it was recognized that the  相似文献   

11.
A novel benzoxazine (BOZ) monomer is synthesized by a pot method with solvent-free to blend with cyanate ester (CE). A soluble intermediate is obtained after being cured for 20 h at 80 ℃. The two model compound and the blends are analyzed with the infrared radiation (IR), nuclear magnetic resonance (NMR) spectroscopy, and differential scanning calorimetry (DSC). The results show that an intermediate of the iminocarbonate and BOZ structures is formed by the ring-open BOZ reacting with the cyanate groups and ring-unopened BOZ. Moreover, rearrangement and ring-opening occur in the postcure of the intermediate to form the alkyl isocyanurate structure with polybenzoxazine.  相似文献   

12.
China's space cause is based on the development of missile technology. In the 1950s, new China, which was just founded, decided to keep pace with the jet technology times, to begin developing missile and rocket science and technology, and to establish China's new space scientific and technological industry.  相似文献   

13.
Materials on experimental studies to determine the effect of thin condensate films of cesium (used as a model working medium for electric propulsion engines and some spacecraft power sources) on integral optical coefficients of spacecraft thermal control coatings are presented. A technique modified by the author and employing the regular thermal regime of a thin metal plate is used. Measurement results demonstrate that films with thicknesses of 100–1000 Å can seriously degrade the integral optical coefficients of thermal control coatings and thus disturb the heat balance of some spacecraft systems.  相似文献   

14.
Broadly speaking,China's spaceindustry includes space technology,space science and space application.The paper mainly covers China'sspace technology. China's space technology indus-try consists of artificial satellites,launch vehicles,launch and recov-  相似文献   

15.
Cosmic Research - Calculations were made of the volume and integral emission intensities of the Lyman–Birge–Hopfield (LBH) bands of molecular nitrogen at 146.4, 138.4, 135.4, and 132.5...  相似文献   

16.
The electromagnetic radio-frequency emission of the inner region of the Earth's plasmasphere discovered recently by the GEOTAIL satellite [4] and referred to as the kilometric continuum was observed by the INTERBALL-1 satellite (1995–2000) in the 100–500 kHz band in the AKR-X experiment. During a period of low solar activity (1995–1997), this continuum was found leaving the inner plasmasphere at geocentric distances of 2–4R E as isolated pencil-like (1°–6°) beams located in the magnetic equator plane. During a time of high solar activity (1999–2000), the occurrence of the emission was extremely rare (it was observed only at a considerable fall of this activity). If detected, at the same geocentric distances (2–4R E) the continuum demonstrated a strongly variable and perturbed character, as well as a considerably larger extension of the beam over the geomagnetic latitude (10°–20° and more). In addition, quasi-periodic (QP) signals, similar to the observed QP emissions of Jupiter, were sometimes detected in this period. The probable nature of the observed features of the kilometric continuum is briefly discussed.  相似文献   

17.
《Acta Astronautica》2001,48(2-3):153-156
Whether welding processes are used on earth or in space, they have the same objective: to obtain defect-free welds. To fully understand the effect of gravity on the weld pool geometry and solidification one should perform experiments within a broad range of gravitational acceleration. High-gravity arc welding experiments were done on Al–Li alloy using the centrifuge called Multi-Gravity Research Welding System (MGRWS). At a high “g” level, buoyancy-driven flow is the dominant force in the weld pool over the Marangoni and the electromagnetic forces. Preliminary results show that the average grain size in the fusion zone at 1g is smaller that at 5g.  相似文献   

18.
The development of China's space technology has been the focus of the world attention. Since the successful launch of DFH-1 artificial earth satellite on April 24, 1970, China has sent 33 indigenous satellites, including scientific experimental satellites, technical experimental satellites and meteorological satellites. All the experimental and operational satellites have played an important role in the construction of national economy and defense, and provided the advanced prapagation instruments for China's science, culture and education, and people both in cities and countries could watch TV andlisten to the radio and take part in telelecture. This has improved the cultural quality of the whole nation and accelerated the development of the four modernizations.  相似文献   

19.
In this paper,the development ofsatellite ground systems and non-satellite equipments and systems de-rived from satellite technology inthe Chinese Academy of SpaceTechnology is reviewed.Satelliteground systems include those fortracking,monitoring and controlfor the launch and operation ofsatellites as well as transmitting andreceiving system for dedicated andindividual users.Derived systemsand equipment include some ofspinoff from satellite technologies,such as computer measurement andcontrol,attitude control,thermalcontrol,radio electronic technique,vacuum technique and new materi-als.They are related to the eco-nomic and social benefits derivedfrom the development of space tech-nology.  相似文献   

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