迎风紧致格式与热流计算

该文在朱庆勇、马延文(1998)一文的基础上给出了利用迎风紧致格式求解NS方程.它是UCGVC格式在粘性流计算中的推广.对于方程中的无粘部分利用Steger-Warming的通量分裂技术将流通向量分裂成两部分,在此基础上据风向构造逼近于无粘项的三阶迎风紧致格式.对方程中的粘性部分采用通常的二阶中心差分格式.该文利用对Burgers方程的特征分析,研究了为正确模拟边界层内的流动特征对网格雷诺数的限制条件.通过对超声速粘性球头绕流的数值模拟表明:迎风紧致格式能在较大的网格雷诺数的条件下计算热流值,结果是令人满意的

Community of benthic macrofauna on sandy intertidal zone in Chinese Horseshoe Crab Reserve in Pingtan island,China

2015年7月底,在平潭岛中国鲎(Tachypleus; tridentatus)保护区沙质潮间带进行了大型底栖动物调查。结果表明,在山岐澳和坛南湾沙质潮间带未发现鲎的幼体和成体,证实中国鲎在山岐澳和坛; 南湾已经面临濒危的境况。山岐澳潮间带的大型底栖动物物种数、物种多样性指数(H')、均匀度指数(J)和丰度指数(d)均高于坛南湾潮间带的大型底栖动; 物物种数、物种多样性指数、均匀度指数和丰度指数,而山岐澳潮间带的大型底栖动物栖息密度和生物量低于坛南湾潮间带的大型底栖动物栖息密度和生物量。两个; 海湾大型底栖动物群落的差异与肋(虫昌)螺(Umbonium; costatum)分布有关,坛南湾潮间带栖息着高密度的肋虫昌螺,而在山岐澳潮间带肋(虫昌)螺很少。AZTI's海洋生物指数(AMBI)和多变量海; 洋底栖生物指数(M-AMBI)值证实山歧澳和坛南湾沙质潮间带生态环境均属于受轻度扰动状态。山岐澳主要受海水养殖的影响,吊养的生物和浮筒减缓了水动; 力,导致山岐澳潮间带低洼区表层为泥质沉积物。坛南湾是旅游区,潮间带受人为踩踏较多。At the end of July 2015 , the benthic macrofauna were investigated in; sandy intertidal zone in Chinese Horseshoe Crab Reserve in Pingtan; island. The results showed that both the larvae and adult of Chinese; horseshoe crab were not found in sandy intertidal zone in Shanqi bay and; Tannan bay. It was confirmed that Tachypleus tridentatus stayed in an; endangered situation in the two bays. The species number, species; diversity index (H'),evenness index (J) and a-bundance index (d) of; benthic macrofauna in Shanqi bay were all higher than those in Tannan; bay,while the density and biomass of benthic macrofauna in the; intertidal zone of Shanqi bay were lower than those in Tannan bay. The; difference of benthic macrofaunal community between Shanqi bay and; Tannan bay was related to the distribution of Umbonium costatum . The; density of Umbonium costatum was high in Tannan bay,but it was few in; Shanqi bay. The values of AZTI' s Marine Biotic Index ( AMBI) and; Multivariate Marine Benthic Index (M-AMBI) showed that the ecological; and environmental status both in Shanqi bay and Tannan bay were slightly; disturbed. The mariculture was the key factor in Shanqi bay,because the; suspending aquatic organisms and floats retarded hydrodynamic force led; to muddy sediment in lower intertidal zone in Shanqi bay. Tannan bay is; a tourism region, where has more artificial tread than Shanqi bay.海洋公益项目; 国家自然科学基金面上项目; 厦门大学2015年大创资助项

准噶尔盆地南缘沙生植被恢复与重建技术研究

本成果为国家十一五科技支撑计划课题《准噶尔盆地南缘沙生植被恢复与重建技术研究与示范》(2007BAC17B03,2007年～2010年)的主要内容。 古尔班通古特沙漠是世界著名的温带沙漠,是重要的植物抗逆种质资源库。植被分布对防风固沙,保持天山北坡经济带的可持续发展和新疆政治、经济、文化稳定与繁荣至关重要。但由于垦荒、樵采、放牧、油田工程建设,以及河流断流,导致古尔班通古特沙漠南部植被退货,同时由于植被恢复技术树木成活率过低,因此提出本课题,通过三年研究主要取得以下进展： 1.通过连续三年试验,总结出沙丘阴坡、阳坡、丘间平地等3种不同立地条件的梭梭免灌造林技术,沙丘顶部活化..

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^