基于纳米间隔电极对的DNA分子结电输运的研究进展

脱氧核糖核酸分子是一类重要的生物分子,在生物医学领域之外,该类分子还因为其所具有的独特的双螺旋结构以及长程输运能力,在分子电子学领域也引起了研究者的极大兴趣.本文综述了近年来基于纳米间隔电极对构筑分子结这一研究范式,在构筑脱氧核糖核酸分子结以及研究后者的电输运性质等方面的研究进展.依据研究者所采用的不同纳米间隔电极对构筑技术,主要围绕裂结法和切割法两大类研究方法所展开.前者主要包括扫描隧道显微镜裂结法、导电原子力显微镜法、机械可控裂结法,后者则主要包括碳纳米管切割法、石墨烯切割法、硅纳米线切割法.在梳理不同实验方法的发展脉络、比较不同实验方法的各自特点的基础上,对一些具有代表性的关于脱氧核糖核酸分子结的研究工作进行了重点介绍,探讨了脱氧核糖核酸分子结所具有的与常规小分子体系所不同的特殊电学性质,同时对该领域的未来发展进行了展望.中南大学湘雅三医院“新湘雅人才工程”(No.20150203)国家重点研发计划(No.2017YFA0204902)国家自然科学基金(No.21722305)资助~

Drag reduction using riblets downstream of a high Reynolds number inclined forward step flow

Micro-riblet is an efficient passive method for controlling turbulent boundary layers, with the potential to reduce frictional drag. In various applications within the transportation industry, flow separation is a prevalent flow phenomenon. However, the precise drag reduction performance of riblets in the presence of flow separation remains unclear. To address this, an inclined forward step model is proposed to investigate the interaction between riblet and upstream flow separation. The large eddy simulation (LES) method is applied to simulate the flow over geometries with different step angles and riblet positions. The results show riblets still reduce wall frictional resistance when subjected to the upstream flow separation. Remarkably, as the angle of the step increases from 0 degrees to 30 degrees, the drag reduction experiences an increment from 9.5% to 12.6%. From a turbulence statistics standpoint, riblets act to suppress the Reynold stress in the near-wall region and dampen ejection motions, thus weakening momentum exchange. Quadrant analysis reveals that with the augmentation of flow separation, the Q2 motion within the flow field intensifies, subsequently enhancing the riblet-induced drag reduction. Moreover, the position of the rib lets has a significant impact on the pressure drag. Riblets close to the point of separation enhance flow separation, altering the surface pressure distribution and thus increasing the resistance. The results reveal that when the riblets are positioned approximately 160 riblet heights away from the step, their effect on the upstream flow separation becomes negligible. The precise performance of riblets under complex flow conditions is important for their practical engineering application

关于配网电力工程技术的可靠性的相关思考

随着新时代经济的发展，国民的生活水平也大大改善，而其对于电力的需求也日益提高。如今，各类电器已普遍存在于企业和人们的生产生活中，怎样合理分配电力成为目前电力工程发展亟待解决的问题，这是保障中国综合经济发展的必经之路。论文就配网电力技术的可靠性进行分析，并给出几点发展策略，加以讨论。</jats:p

解析电力工程技术管理的难点和对策

随着电力行业的发展，其操作的规范性和安全性逐渐受到关注，从可持续发展的角度来看，必须制订完整的电力工程管理方案，保障科学合理的施工，避免发生危害。论文就电力工程技术管理进行分析，并提出几点解决对策，加以讨论。</jats:p

on subscription persistence of pub/sub service in cloud

发布/订阅服务让用户提交订阅来表达其所关心的事件,并能在检测到这些事件发生时,及时发送事件通知给感兴趣的用户。依托云平台构建的发布/订阅服务旨在提高其吞吐量和可伸缩性,特别是提高在面对大规模订阅/事件时的事件检测性能。为了保证订阅的可用性,并加快负载均衡的速度,为云上的发布/订阅服务设计、实现了订阅的持久化机制。为了评估订阅持久化机制,进行了一系列对比实验,实验数据表明订阅持久化机制能加快负载转移,从而加快代理达到负载均衡。国家自然科学基金项目(60970027)Publish/subscribe (pub/sub) services permit users to submit subscriptions to declare their interests in specific events and send event notifications to users interested while they detect the occurrences of the corresponding events. A Pub/Sub service which is built over cloud infrastructure aims at improving throughput and scalability, especially the performance of event detection while facing large-scale subscriptions and/or events. In order to ensure the availability of subscriptions and accelerate the speed of load balance, subscription persistence mechanism is designed and implemented in Pub/Sub service in the cloud. Furthermore, a series of comparative experiments are conducted, and the experimental results illustrate that subscription persistence mechanism can speed up the load transfer and further the load balance among brokers

长链非编码RNA GAPLINC对类风湿关节炎成纤维样滑膜细胞增殖表型的影响

目的探讨长链非编码RNA GAPLINC对类风湿关节炎成纤维样滑膜细胞（RA-FLS）增殖表型的影响。方法收集2022年1月至2022年12月于海南医学院附属海南医院行滑膜清理术或膝关节置换术的4例RA患者及3例创伤性关节炎废弃滑膜组织，分离培养并鉴定FLS细胞。通过qPCR法检测RA组和创伤组滑膜细胞内LncRNA GAPLINC表达水平。利用siRNA干扰技术靶向敲低GAPLINC表达，通过EdU法检测各组细胞增殖水平、流式细胞术检测各组细胞的细胞周期分布情况。通过qPCR法与WB法检测细胞周期调控蛋白cyclin D1、PCNA及周期抑制蛋白P21的表达水平。结果本研究通过qRCR验证发现，RA组LncRNA GAPLINC表达水平明显高于创伤组（P&lt;0.05）；特异性siRNA对GAPLINC的干扰效率为（85.96±1.76）%（P &lt;0.05）。敲低GAPLINC后，EdU细胞增殖实验显示，与空白对照组（6.02±0.48）%、溶剂对照组（6.32±1.48）%和阴性对照组（6.12±1.51）%相比，GAPLINC干扰组S期细胞占（2.89±1.53）%，较各对照组明显降低（P &lt;0.05）。利用流式细胞术检测各组细胞周期分布，结果显示GAPLINC干扰组PI值，即S+G2/M期细胞所占的百分比为（14.92±5.34）%，明显低于空白对照组（29.68±8.48）%、溶剂对照组（28.97±6.82）%、阴性对照组（31.13±5.13）%（P&lt;0.05）。敲低GAPLINC后，与增殖表型正相关的基因Cyclin D1和PCNA的mRNA和蛋白水平均下降 （P&lt;0.05），而与增殖表型负相关的基因p21表达上调（P&lt;0.05）。结论LncRNA GAPLINC在RA-FLS细胞中高表达，敲低GAPLINC表达后，能显著降低RA-FLS细胞增殖活性，抑制细胞周期转化，提示LncRNA GAPLINC可能影响RA-FLS细胞增殖表型，导致滑膜异常增生，参与RA疾病的进展

SiC对粉碎烧结法制备P型Bi0.5Sb1.5Te3合金热电性能的影响

向粉碎法制备的Bi0.5Sb1.5Te3+5%Te（质量分数）合金粉体中混入不同体积分数的SiC颗粒，利用放电等离子体烧结法制备SiC复合块体材料，探究块体材料组织和热电性能的变化规律。研究发现：随着SiC体积分数的增加，块体材料的取向性弱化，组织细化，载流子浓度增加，迁移率降低；由于取向性弱化及组织细化，加强了声子散射，降低了晶格热导率。由于SiC复合块体材料的电学性能恶化，块体材料的无量纲热电优值（ZT）并未获得显著的提升；当SiC体积分数为0.40%时，SiC复合块体材料在322 K时具有最优的无量纲热电优值（ZT=～0.81）