以2022年9月影响东北地区的台风“梅花”残余系统降水为例,采用SAL(structure amplitude and location)空间检验方法对5种中国气象局数值业务模式(CMA模式)降水最强日(2022年9月16日08时至17日08时,热带低压)累计24 h降水预报进行空间...以2022年9月影响东北地区的台风“梅花”残余系统降水为例,采用SAL(structure amplitude and location)空间检验方法对5种中国气象局数值业务模式(CMA模式)降水最强日(2022年9月16日08时至17日08时,热带低压)累计24 h降水预报进行空间检验、偏差成因及预报调整分析。结果表明:此次过程中各模式在降水位置方面预报均较好,CMA-GFS在降水结构分布、强度方面预报表现最佳,除CMA-BJ外其他模式对于降水极值预测均偏小。CMA-GFS预报效果最佳的原因是其对于台风变性、850 hPa低空急流及暖式切变线位置、强度以及移速预报更准确,CMA-TYM预报较差主要是未能预报出台风变性,对切变线预报速度过快而导致暴雨落区偏大。CMA-GFS随着预报时效的临近,预报效果越来越好,优势主要体现在临近时效内,但在长时效预报中几乎无预报能力,CMA-TYM虽然在临近时段结构与强度预报效果较差,但在长预报时效是最早指示出强降水大致落区与量级的模式。展开更多
In this paper, a set of ultrasonic vibration device connecting with small angle light scattering(SALS) for in-situ observing phase-transition of polymer under ultrasonic vibration was established. The experiments for ...In this paper, a set of ultrasonic vibration device connecting with small angle light scattering(SALS) for in-situ observing phase-transition of polymer under ultrasonic vibration was established. The experiments for verifying polypropylene(PP) indicated that ultrasonic vibration resulted in the decrease of the crystallization rate and made PP crystallizable at low temperature.展开更多
SALS(Single Anchor Leg Storage)系统是单点系泊系统形式之一。以油轮为基础的SALS系统具有适用水深大、投资小、可重复利用、本身具有储油能力、安装方便且无须特殊设备协助等特点。随着海上石油开发向深水、恶劣海况推进,SALS系统的...SALS(Single Anchor Leg Storage)系统是单点系泊系统形式之一。以油轮为基础的SALS系统具有适用水深大、投资小、可重复利用、本身具有储油能力、安装方便且无须特殊设备协助等特点。随着海上石油开发向深水、恶劣海况推进,SALS系统的应用日趋增多。我国南海珠江口盆地的海况恶劣,台风频繁,水深多在100 m以上。因而,进行SALS系统在南海油田开发中的可行性研究有着重要的意义。 SALS系统的基本构成如图1所示,是由单浮筒系泊发展过来的单锚腿存储系统。展开更多
Sally and her friend Beth are walking in the community center.They started taking a craft class there a few weeks ago."Wasn't that a fun class,Sally?"asks Beth."It was!I want to get some supplies to...Sally and her friend Beth are walking in the community center.They started taking a craft class there a few weeks ago."Wasn't that a fun class,Sally?"asks Beth."It was!I want to get some supplies today.I need a few things for class on Friday,Sally says.展开更多
文摘In this paper, a set of ultrasonic vibration device connecting with small angle light scattering(SALS) for in-situ observing phase-transition of polymer under ultrasonic vibration was established. The experiments for verifying polypropylene(PP) indicated that ultrasonic vibration resulted in the decrease of the crystallization rate and made PP crystallizable at low temperature.
文摘利用T-mode斜交旋转主成分分析法,对湖南2021年汛期(4—9月)逐小时850 hPa风场进行环流分型,在此基础上开展同期华南快速循环同化模式(CMA-GD-R3)小时降水预报性能检验。结果表明:影响湖南2021年汛期的主要环流型为西南涡切变型、切变型、副热带高压边缘南风型和台风外围东风型4类;模式小时降水预报的晴雨准确率和分级降水TS评分日变化特征明显,晴雨准确率夜间高于白天,分级降水TS评分峰值出现在早晨,各环流型的临近时效降水预报效果较好,短时强降水发生频次最高的西南涡切变型晴雨准确率较低,副热带高压边缘南风型在较大量级降水表现相对较差;SAL(structure amplitude and location)检验显示,西南涡切变型、切变型过程模式位置预报较接近实况,强度预报表现为前弱后强,副热带高压边缘南风型过程预报落区分散,位置预报不稳定,整体强度较实况明显偏弱,台风外围东风型过程在短时预报时效落区接近实况,强度预报显著偏弱,该方法能较客观地反映模式降水预报空间偏差。
文摘Sally and her friend Beth are walking in the community center.They started taking a craft class there a few weeks ago."Wasn't that a fun class,Sally?"asks Beth."It was!I want to get some supplies today.I need a few things for class on Friday,Sally says.
