Sur des conditions d''amorçage par onde de choc de la détonation du nitrométhane

Results concerning the thermodynamic and mechanical properties of nitromethane (N.M.) at pressures up to 11 GPa are presented. The pressure is generated either by an incident shock wave or by a shock wave reflected within a medium prepressurized by a first shock wave. Calculation of the temperature behind these shock waves, based on the Walsh-Christian model, calls, in particular, upon the knowledge of the N.M. shock polar relative to normal temperature and pressure conditions, but also of those corresponding to prepressurized states.

Taking advantage of the phenomena of N.M. electric polarization under shock, we determine, on the one hand, the relation between pressure and particle velocity and, on the other hand, the influence of pressure conditions on induction delays of the explosive.

According to calculation, for a same pressure level the N.M. temperature behind a single shock is higher than that obtained by two successive compressions.

Experimentally, we observe that N.M. compressed at 11 GPa by means of two shock waves does not detonate (during the observation time of about 0,5 μs), while in the case of a single shock wave of the same amplitude the induction delay is lower than 0.1 μs. These results show the important role of temperature, as opposed to that of pressure.     

Le silence éternel de ces espaces infinis?

During the last 40 years — the merest blip in world history — talk about Homo astronauticus has signalled a growing awareness that the passengers on planet Earth can, if they want, take off for other destinations. If the scale of past advances is a satisfactory measure of future possibilities, then the wish will be father of the achievement.     

SJ-9 Satellite Delivered

On August 21,the SJ-9 satellite delivery ceremony was held in Beijing which marks its formal operation.Yuan Jie,Vice President of CASC attended the ceremony.SJ-9 has conducted in-orbit new product verification of 24 categories which are badly needed for China’s satellite development,and evaluation and assessment on over 20 types of domestic core elements and materials of10 categories.It firstly accomplished the satellite formation flight and high-accurate GPS interplanetary measurement     

中国卫通签订中星9号卫星购买合同

4月21日,中国第一代广播电视直播卫星系统———中星9号卫星订购合同签字仪式在人民大会堂举行。我国总理温家宝和法国总理拉法兰出席了签字仪式。中国卫星通信集团公司总经理张海南和法国阿尔卡特空间公司董事长兼首席执行官苏睿思共同签署了《中星9号卫星购买合同》。中星9号     

“遥感九号”发射成功

<正>3月5日12点55分,酒泉卫星发射中心阳光普照,万里无云。长征四号丙运载火箭冒着低温腾空而起,用一个完美的托举成功地将遥感卫星九号送入太空。总装备部副部长牛红光,国     

国际空间站迎来新机组

经过2天的飞行，俄罗斯联盟TMA4载人飞船于莫斯科时间4月21日9点03分成功完成与国际空间站曙光号功能货舱的自动对接，为该站送去了2名第9长期机组成员和1名作短期考察的欧洲航天员。4月21日，新到达的机组成员来不及休息就开始收拾各自所带的科学仪器及私     

GF-9 Satellite Launched into Space

<正>The GF-9 satellite was launch from the Jiuquan Satellite Launch Center at12:42 Beijing time on September 14aboard a LM-2D carrier rocket,only 37hours after the launch of a communications technology test satellite in Xichang.It was the 209th flight of the LM rocket series.GF-9 is an optical remote sensing satellite under the China High Resolution Earth Observation System(CHEOS)Major Special Project.The satellite is capable     

“猎鹰”9火箭首射成功

<正>美国私营公司太空探索技术公司的"猎鹰"9火箭6月4日在卡纳维拉尔角空军站进行了首次发射,将一艘货运飞船的试验样船送入250公里的预定轨道。这     

CASC Guaranteed Success of Shenzhou 9 Mission

<正>China’s first manned space docking mission between Shenzhou 9 spaceship and Tiangong1 target spacecraft achieved a complete success when all the three astronauts aboard climbed out of the Shenzhou 9 recoverable capsule in good physical condition on June 29. Jing Haipeng, commander of the Shenzhou 9, climbed out of the