摘要：Using an optical vortex coronagraph （OVC） is one of the most promising techniques for di- rectly imaging exoplanets because of its small inner working angle and high throughput. This paper presents the design and laboratory demonstration performance of an OVC based on liquid crystal polymers （LCPs） at 633 nm and 1520 nm. The OVC can deliver good performance in laboratory tests and achieve a contrast of 10-6 at an angular distance of 3A/D, which can be implemented for imaging young giant exoplanets in combination with extreme adaptive optics.

摘要：Polarimetry plays an important role in the measurement of solar magnetic fields. We devel- oped a high-sensitivity and high-accuracy polarimeter （HHP） based on nematic liquid crystal variable retarders （LCVRs）, which has a compact setup and no mechanical moving parts. The system design and calibration methods are discussed in detail. The azimuth error of the transmission axis of the polarizer as well as the fast axes of the two LCVRs and the quarter-wave plate were determined using dedicated procedures. Linearly and circularly polarized light were employed to evaluate the performance of the HHP. The experimental results indicate that a polarimetric sensitivity of better than 5.7 × 10-3 can be achieved by using a single short-exposure image, while an accuracy on the order of 10-5 can be reached by using a large number of short-exposure images. This makes the HHP a high-performance system that can be used with a ground-based solar telescope for high-precision solar magnetic field investigations.

摘要：A high-contrast coronagraph for direct imaging of an Earth-like exoplanet at the visible band needs a contrast of 10^-10 at a small angular separation of 4λ/D or less. Here we report our recent laboratory experiment that approaches these lim- its. Our test of a high-contrast imaging coronagraph is based on our step-transmission apodized filter. To achieve this goal, we use a liquid crystal array as a phase correc- tor to create a dark hole based on our dedicated algorithm. We have suppressed the diffraction and speckle noise near the point image of a star to a level of 1.68 × 10^-9 at 4λ/D, which can be used for direct imaging of Jupiter-like exoplanets. This demon- strates that a telescope incorporating a high-contrast coronagraph in space has the potential to detect and characterize Earth-like planets.

摘要：针对典型的簸箕型进水流道 ,应用紊流模型对流道内部流态及水泵吸水管各断面流速分布进行了数值模拟 ,计算结果符合实际情况。数值计算揭示了簸箕型进水流道内流动规律 ,进水流道吸水管下方存在奇点 ,如相关设计参数不当易产生漩涡。根据计算分析 ,提出大型泵道簸箕型控制参数 。

摘要：　针对各种典型的进水流道,应用紊流模型对流道内部流态及水泵进口处的流动进行三维数值计算,计算结果表明各种流道内部水流流态相似。数值分析显示各种有压的喇叭管进水的流道都是在开敞式进水池形式基础上演变而成的,只要控制流道的基本尺寸,就可将各种喇叭管进水的流道统一起来。研究成果为泵站进水流道优化设计提供新的思路。

摘要：目的 设计重测信度高的小鼠颈肌前庭诱发肌源性电位(cVEMP)实验方法以验证定位胸锁乳突肌的准确性。方法 选用2月龄ICR雄性小鼠3只,1只解剖定位小鼠胸锁乳突肌,其余2只设计实验方案验证定位准确性。结果 记录电极定位到小鼠胸锁乳突肌上可重复引出清晰的cVEMP波形。结论 根据2只实验小鼠均可测得重测信度高的cVEMP波形,提示本研究定位胸锁乳突肌位置准确。

摘要：论述了产品包装设计创意中间接经验的概念、特点和来源。在对间接经验进行分析的基础上,指出了间接经验在产品包装设计创意中的意义和作用。从某种程度上说,间接经验能够作为衡量一个产品包装设计师创意能力的参考,以此来丰富产品包装设计创意的内涵,同时给设计师的创作提供一定的指导。

摘要：出钢时间是影响转炉生产效率和生产成本的重要因素,过长的出钢时间,不仅占用了时间资源,降低生产效率,而且使得转炉内钢水和钢包温度损失加大、出钢口侵蚀加剧、出钢口寿命降低、能源消耗增加。2023年以前,唐山钢铁公司长材事业部受到转炉出钢温度偏高、钢水氧化性强等不利因素影响,转炉出钢口寿命平均180炉,平均更换时间长达40 min左右,限制了转炉作业率的进一步提高。本文详细介绍了唐山钢铁公司100 t转炉出钢口优化的具体措施,实践表明,通过优化出钢口孔设计、缩短出钢口寿命前期的出钢时间、终点高拉碳、出钢口制作工艺等操作,可以降低出钢温度且降低终点氧质量分数至0.035%,出钢口寿命提升至350炉以上,经济效益良好。

摘要：研究视频广告与动漫广告的组合技术,创作出更加新颖、精美、吸引观众眼球的广告片,具有现实意义.运用AE软件的"假配真"、"穿插"、"仿三维"、动态影像跟踪、抠像、广告画面稳定等功能,将视频广告与动漫广告巧妙地组合在一起,构成一种新型的组合型广告.与传统的广告相比,组合型广告具有生动性、时尚性、趣味性等独到的优势,故市场投放与推广前景良好.

摘要：结合典型案例从造型定位、色彩表现、材质选取和信息功能演绎4个方面论述了MP3产品设计中的艺术内涵。提出MP3设计不单是物的设计,而且要从审美的视角综合考虑经济、社会、文化等方面以满足人的需要。这对于数字化产品的创新具有一定的指导意义。