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  PL-10: Infrared guided sidewinder: In the late 1990s, Beijing kicked off the transformation with the PL-10, a high-off-boresight, infrared-guided short-range missile rivalling the US AIM-9X Sidewinder and Russia’s R-73 Archer. PL-12: Medium range AESA active radar guided missile: The follow-on PL-12 added a medium-range active radar-guided punch akin to the AIM-120 AMRAAM, gradually giving the PLAAF confidence that it could match or exceed Russian and Western benchmarks. PL-15: AESA ramjet In recent years, the PL-15 — reportedly featuring an AESA radar seeker and solid fuel ramjet propulsion — extended Beijing’s aerial reach further, threatening front-line fighters and support aircraft alike at ranges believed to exceed 200 km. PL-17: 400km range PL-15 The PL-17 upped the ante, with a reported operational range of 400 km, explicitly designed to push back the ‘safe zones’ where American tankers and AWACS typically orbit in support of fighter patrols. 空警-3000 空警-3000，据信搭载了划时代的共形天线技...

  Sogdian： 蘇特 / 粟特 Unesco online forum series : Black death:

The Sidereal Period of an object is the time it takes to make a complete circuit of the celestial sphere with  respect to the fixed stars. The Synodic Period is the time required to make a circuit of the celestial sphere  with respect to the Sun - which is also moving eastward among the stars. The synodic period is always  greater than the sidereal period, the difference being due to the apparent motion of the Sun. The sidereal  period of the Moon is the time it takes to go once around the Earth; the sidereal period of a planet is the  time it takes to go once around the Sun. i.e., its orbital period. Worked example on planets: Reference  Nmsu kurt Nmsu nicole Nao jp

 基於  中國國家天文  古代中國土星觀測 唐代僧一行在《大衍历》中进一步提出“五星盈缩历表”，通过数学模型提高计算精度。这里的所谓“盈”就是加速，“缩”就是减速。 “五星盈缩历表”可以理解为在之前“五星入气加减法”的基础上进行再设计的精密数学模型，这也依赖于当时天文观测仪器的进步。其核心是将行星轨道划分为若干区间，标注各区间内行星的平均日行度与盈缩差。然后是修正参数：通过“损益率”（增减速度的比例）和“躔差”（位置偏差）等参数，动态调整行星的实际位置计算。btw, 現今的通勝也繼續沿用此類計算表，但筆者沒提及當中不同時代的演進史。 （隋朝张胄玄造大業曆，始立五星入气加减法，及日应食不食术） 會合周期 Synodic period: 在《五星占》的那个时代，1度是被分为240分，因此，“日行八分”就是“三十分之一度（中国古度，合0.9856º）”，约为0.03285º，而今测值约为0.03346º。二者相差无几。 (照估計，“分”是用來作記錄，計算，而非現今觀測儀器中角度的刻度） Conceptually wrong/misleading here. 古藉 五星占 中 “一終” refers to 會合周期 (synodic period), 但“日行八分”is talking about 恆星周期（sidereal period) These accuracy advances contributed to good record keeping, and good observation skills.  幾千年的完整觀測紀錄 > 歸納整理 > 找出“逆行周期”或 " 兩次“晨始見”的時間 （opposition period)  What type of  instruments( before invention of telescope) used are not mentioned 儀象考成 恆星周期： Present day 1/sidereal period= 1/10755.7=0.0335 degree. But the writer did not elucidate how “日行八分” is derived. And how to find sidereal period...

澳飾嘉Osiza 江門市嘉程商貿有限公司 有CCC 標， QA 及格証 型號 8875/Y1 燈的部份很好 聲控正常 Controller box FH(40-72 W) x2 但 Smartphone app  FanLamp Pro 不能用. Lamp control ok. Fan control not working . Is it copycat clone of Alexa? Remote control ( marking FH-FAN-B) 遙控 DZ款 disassembly pics PCB marking: CC04, 13180 但風扇吵到想死！！！ 6x dB 問題 in here Problem found: the motor has 3 lugs(55,55,75) for positioning to the black vertical mount. Only 2 of lugs can fully, flatly sit on black mount. So the Motor is not sitting properly at right angle to mount!!! Btw， the Motor wirings are fragile. No strain relief at all. Easily tear the wires off the solder joint. I guess the proper connector is missing, to save cost can only say, it's 山寨quality. QC label means nothing. Likely the production line just buy parts from unreliable/ changing sources, who just claim the parts are "standard" and compatible. Which is just talking. Just like the fan lamp controller. Which is actually another version with some feature missing. Caus...

Thunder and rain before the typhoon Wipha approach  Satellite images from FY-4B 18/7 00:00 03:00 05:00 09:00 12:00 15:00 18:00 21:00 19 jul 00:00 Reference  Cma cn Hurricanezone   Digital typhoon japan Detail google map from agora japan in JST(UTC+9)

From Czechia A projector lens, double gauss, aka poorman's biotar fb compare Conversion  to M4/3 Radojuva Allphotolenses Take a spring walk Dpreview MFLenses 70mm f1.4 mflenses   Projector lens design Zemax 

Wiki Battle of Talas K(Q)arluq Turks 葛羅祿 For five days, the mighty armies clashed. When the Qarluq Turks came in on the Arab side several days into the fighting, the Tang army's doom was sealed. Chinese sources imply that the Qarluqs had been fighting for them, but treacherously switched sides midway through the battle. Arab records, on the other hand, indicate that the Qarluqs were already allied with the Abbasids prior to the conflict. The Arab account seems more likely since the Qarluqs suddenly mounted a surprise attack on the Tang formation from the rear. Some modern Chinese writings about the battle still exhibit a sense of outrage at this perceived betrayal by one of the Tang Empire's minority peoples. Whatever the case, the Qarluq attack signaled the beginning of the end for Kao Hsien-chih's army. Point of view from Turkey TDDB : Clash of religions (Buddhist/Confucian Asia and Muslim Asia) and victory of Islam in central asia Gao Xian-zhi made a big political mistak...