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：文章介绍了API617规范的重要性以及升版情况,详细对比了API 617第8版和第9版的区别,并结合工程实际进行了解读。API617第9版经过近十年的总结和提升,提出了很多新的设计理念和设计要求,使得标准规范更符合工程实际,能够为广大从业者提供更好的选型设计参考。同时,新版本中的一些要求尚未在实际工程中应用,未来还需各方相互协商、详尽研读、逐步适应。

摘要：为达到全超导托卡马克核聚变实验装置(EAST)长脉冲高功率目标,提高离子回旋波与等离子体的耦合效率,并降低离子回旋共振加热(ICRH)天线法拉第屏蔽的热负载,需对ICRH天线中的法拉第屏蔽进行优化设计。通过RAPLICASOL ICRH天线计算模型对法拉第屏蔽结构进行计算分析,综合考虑最大电场强度、耦合阻抗以及离子回旋天线有限的内部空间,最终确定了法拉第屏蔽的结构尺寸。然后对法拉第屏蔽的流热分布进行了优化和分析。经过仿真优化设计,在300s运行条件下,法拉第屏蔽最高温度为300℃,满足法拉第屏蔽热设计要求。该天线于2021年成功应用于EAST实验。实验结果表明,新ICRH天线的耦合及加热效率明显提高,已完成1.5MW/30s和0.5MW/300s的长脉冲实验,并且法拉第屏蔽最高温度为330℃,满足ICRH天线的设计要求。

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：对导电水凝胶的制备方法、设计策略进行了系统综述,对其在传感、储能、医疗等领域的应用研究进行了重点阐述,并对面临的问题与挑战进行了展望。

摘要：长江上游地区的水库建设、河道改道、堤防修建和水文调节等人类活动对鱼类栖息地造成了严重影响,导致栖息环境恶化和大量栖息地的丧失。为了深入了解这种情况,选取长江上游保护区中段典型代表性朱沱站中4个典型河流断面近3 a的生境数据,分析典型断面的水文特征、水文情势、水环境质量、流速、水深以及珍稀特有鱼类空间分布特征,获取全面的鱼类生境特征数据。基于分析结果,提出建设完善的珍稀特有鱼类增殖放流措施。研究发现,99%的珍稀特有鱼类信号采集于低流速区(0.0~1.4 m/s),其中80%左右的鱼类聚集在流速低于0.8 m/s的缓流区;在冬季越冬期间,鱼群位置点的水深平均值为44.28 m,最小值为15 m,最大值为57.47 m。长江上游的绝对水深在23~56 m之间时,不足以提供鱼类栖息。但在蓄水期,水位抬高进而在同时满足流速、水深和干扰少等条件下,能够改善珍稀特有鱼类的生存环境。通过研究长江上游珍稀特有鱼类资源的生境特征,可以更好地了解鱼类的分布和迁徙规律,辅助合理规划和管理渔业资源。同时,研究增殖措施可以指导人工放流等管理行为,有助于恢复和增强鱼类种群,维持渔业可持续发展。

摘要：针对跨海桥梁地质模型与结构体模型融合不足、共享利用难等问题,论文提出了一种基于BIM的地质体和结构体动态建模与集成共享技术,包括以SpringBoot作为主框架的多元数据融合地质数据库搭建,基于Kriging插值的三维地质模型自动构建Revit插件研发,基于Dynamo定制化族库的桥梁结构体参数化建模,以Cesium作为三维引擎的模型数据集成共享可视化平台开发。在黄茅海跨海大桥中的应用结果表明该技术能够有效提高跨海桥梁地质模型与结构模型的建立与共享效率。