Nonlinear local stabilization control of flexible satellite attitude system

本文针对挠性卫星姿态机动和振动抑制问题,给出一种基于多项式平方和(SuM Of SQuArES,SOS)的非线性局部镇定控制方法.根据姿态系统结构特征,在此基础上,采用SOS结合S-PrOCEdurE理论,得出相应的非线性局部可镇定条件.该条件可借助有效凸优化工具进行检验,当优化问题可解时,可构造非线性姿态控制器的解析解.最后,将文中方法应用于某型挠性卫星姿态控制.仿真结果表明,在实现大角度姿态快速机动的同时,有效抑制了挠性附件振动.Based on the polynomial sum of squares(SOS) techniques, a nonlinear local stabilization control approach is proposed for the problem of flexible satellite attitude maneuver and vibration suppression.According to the structural features of attitude system, a nonlinear local stabilization controller is developed and the complexity of attitude control design is reduced effectively by employing a separation principle for the reduced-order observer and state feedback.On this basis, the corresponding conditions of nonlinear local stabilization, which can be checked through convex optimization algorithms, are presented by using the SOS and S-procedure theory, and the analytical solution of nonlinear attitude controller can be constructed if the optimization problem is solvable.Finally, this method is applied to the attitude control of a flexible satellite and the simulation results show that both the fast large angle attitude maneuver and the vibration suppression are well realized.国家自然科学基金资助项目(61374037); 高等学校博士学科点专项科研基金资助项目(20110121110017

Robust stabilization for a class of polynomial systems with polytopic uncertainties

针对一类含多面体不确定性的多项式系统,研究其局部稳定鲁棒镇定问题.基于多项式平方和(SOS)技术,将该类非线性控制问题转换为凸的SOS规划问题,并通过引入S-PrOCEdurE技术,保证了所得结论在局部范围内是有效的.同时,结合参数依赖lyAPunOV函数方法,给出了该类系统鲁棒性分析与鲁棒镇定控制问题的充分条件,并将其描述为可由SOS规划技术直接求解的状态依赖线性矩阵不等式约束集.最后,通过数值仿真验证了该方法的有效性.The sum of squares(SOS) and the S-procedure techniques are used to analyze the local robust stabilization problems for a class of polynomial systems with polytopic uncertainties.By using the SOS technique,the nonlinear control problems are converted into convex SOS programming ones.And the S-procedure technique guarantees that the result holds in a restricted region.Moreover,sufficient conditions are given for the robust stability analysis and robust stabilization control of the systems based on the parameter dependent Lyapunov function.All these solvability conditions are formulated as a constraint set of state dependent linear matrix inequalities,which can be solved by semidefinite programming relaxations based on SOS programming.Finally,a numerical example verifies the effectiveness of the proposed method.国家自然科学基金项目(61074004;61374037); 高等学校博士学科点专项科研基金项目(20110121110017); 教育部留学回国人员科研启动基金项目[2009

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~

芪参益气滴丸对ApoE基因敲除小鼠动脉粥样硬化中调节性T细胞的影响

目的:研究芪参益气滴丸对动脉粥样硬化中调节性T细胞的影响。方法:采用6周龄雄性C57BL/6J小鼠和Apo E基因敲除小鼠,分为正常组、模型组、芪参低剂量组、芪参高剂量组,每组6只。除正常组外,其他3组小鼠均给予高脂饲料喂养,药物组还给予高、低剂量的芪参益气滴丸,8周后评价内脏指数、动脉粥样硬化病变、调节性T细胞情况。结果:与模型组比较,芪参高剂量组可显著降低肝指数(P<0.05),减少动脉粥样硬化斑块面积(P<0.05,P<0.01),并增加脾脏调节性T细胞数量(P<0.01)。结论:芪参益气滴丸可能通过增加脾脏调节性T细胞数量抑制动脉粥样硬化形成。福建省自然科学基金项目(No.2016J01413);;广东省自然科学基金项目(No.2016A030313860);;教育部留学回国人员科研启动基金项目(No.2015-311);;教育部“新世纪优秀人才支持计划”项目(No.NCET-13-0505);;国家重点研发计划“重大慢性非传染性疾病防控研究”重点专项(No.2016YFC1305903)~

Intratumoral Delivery of a PD-1-blocking scFv encoded in Oncolytic HSV-1 Promotes Antitumor Immunity and Synergizes with TIGIT Blockade

恶性肿瘤已严重威胁人类健康和生命，现有的治疗手段远远未能满足临床需求。厦门大学研究团队联合浙江养生堂生物科技有限公司、养生堂有限公司进行协同攻关，研制出新一代肿瘤免疫治疗药物——“注射用重组人PD-1抗体单纯疱疹病毒”。研究发现，重组表达PD-1单链抗体的溶瘤病毒具有“双药合一”抗肿瘤的突出优势，提高肿瘤治愈率。相关成果于2020年3月3日以研究论文形式在线发表于Cancer Immunology Research（《癌症免疫学研究》）期刊，为指导新型溶瘤病毒的升级改造和突破肿瘤免疫耐受提供了新的思路，为重组表达PD-1单链抗体的溶瘤病毒药物运用于肿瘤临床治疗奠定了坚实的理论基础。 厦门大学公共卫生学院夏宁邵教授和黄承浩助理教授为该论文的共同通讯作者，博士生林超龙和任文峰为该论文的共同第一作者。【Abstract】Oncolytic virotherapy can lead to systemic antitumor immunity, but the therapeutic potential of oncolytic viruses (OVs) in humans is limited due to their insufficient ability to overcome the immunosuppressive tumor microenvironment (TME). Here, we showed that locoregional oncolytic virotherapy upregulated the expression of PD-L1 in the TME, which was mediated by virus-induced type I and type II interferons (IFNs). To explore PD-1/PD-L1 signaling as a direct target in tumor tissue, we developed a novel immunotherapeutic herpes simplex virus (HSV), OVH-aMPD-1, that expressed a single-chain variable fragment (scFv) against PD-1 (aMPD-1 scFv). The virus was designed to locally deliver aMPD-1 scFv in the TME to achieve enhanced antitumor effects. This virus effectively modified the TME by releasing damage associated molecular patterns (DAMPs), promoting antigen cross-presentation by dendritic cells, and enhancing the infiltration of activated T cells; these alterations resulted antitumor T cell activity which led to reduced tumor burdens in a liver cancer model. Compared with OVH, OVH-aMPD-1 promoted the infiltration of myeloid-derived suppressor cells (MDSCs),resulting in significantly higher percentages of CD155+ G-MDSCs and M-MDSCs in tumors. In combination with TIGIT blockade, this virus enhanced tumor-specific immune responses in mice with implanted subcutaneous tumors or invasive tumors. These findings highlighted that intratumoral immunomodulation with an OV expressing aMPD-1 scFv could be an effective standalone strategy to treat cancers or drive maximal efficacy of a combination therapy with other immune checkpoint inhibitors.This work was supported by grant 2018ZX10301404-001-002 from the National Science and Technology Major Project and grant 81571990 from the National Natural Science Foundation of China.该研究获得了国家自然科学基金、国家科技重大专项的资助

Damage to mangroves from extreme cold in early 2008 in southern China

通讯作者Author for correspondence (E-mail: [email protected])2008年初,我国南方19个省经历了50年一遇的持续低温雨雪冰冻天气。极端气候对华南沿海各省的红树林区造成不同程度的危害。2008年3月,在我国南方各省红树林区的10个代表性地点,对这次寒害造成的红树植物伤害程度进行了系统的调查。结果表明:冬季低温对红树林的影响极为显著,特别是在低纬度的海南、广西和广东湛江,由于极端低温正值夜间退潮,对红树林的影响更为显著;在纬度较高的福建,本地红树种类秋茄(Kandelia obovata)、桐花树(Aegiceras corniculatum)和白骨壤(Avicennia marina)及引种的木榄(Bruguiera gymnorrhiza)等,由于长期适应于冬季较低的气温或在种植前经过抗寒锻炼,具有较强的抗寒能力。各地主要红树植物中,广布种秋茄、桐花树和白骨壤最为耐寒,其耐寒性均大于红树科的木榄、海莲(Bruguiera sexangula)和红海榄(Rhizophora stylosa)。海桑(Sonneratia caseolaris)对温度的敏感性最强,抗寒能力最低,因此,即使在其原产地海南也受到较为严重的寒害,在纬度更高的引种地出现大面积受害甚至全部死亡,而从孟加拉国引种的无瓣海桑(Sonneratia apetala)却显示出一定的抗寒能力。同一地点的红树植物幼苗的抗寒能力低于大树。此次寒害也造成了苗圃场的种苗大量死亡,成熟的植株提前落花落果,这势必会影响后继一两年内红树林的自然更新和人工造林。因此,在未来红树林造林或人工引种中,一定要考虑到红树植物的抗寒能力。国家自然科学基金(30671646和30700092);厦门大学“闽江学者”启动基

Robustness Analysis and Control for Systems with Parameter Uncertainties Based on SOS

本文针对三类参数不确定系统，对其非线性鲁棒控制问题展开研究，借助多项式平方和(SumofSquares,SOS)理论，将三类系统的鲁棒控制问题转换为SOS规划问题，使得所得到的控制问题可解性条件，可由Matlab下的SOSTools工具箱计算实现，在一定程度上克服了非线性鲁棒控制方法普遍存在的计算难题。本文的研究主要内容概括如下： 1)借助SOS理论，研究一类具有范数有界不确定性多项式系统的稳定性能分析与控制综合问题。首先，给出该类系统的鲁棒稳定性分析条件和非线性状态反馈镇定控制器的设计方法，该方法利用建立SOS规划问题所引入的独立变量，将系统的不确定性处理条件刻画为状态依赖线性矩阵不等式(...The thesis studies the nonlinear robust control problems of three classes of systems with parameter uncertainties. With the aid of sum of squares (SOS) theory, the robust control problems of the uncertain systems were converted into the convex SOS programming ones,which guarantee the corresponding solvability conditions can be solved by the third-party Matlab toolbox SOSTools, which means that the...学位：工学博士院系专业：信息科学与技术学院_控制理论与控制工程学号：2322009015371

挠性卫星姿态非线性局部镇定控制 优先出版版本

本文针对挠性卫星姿态机动和振动抑制问题,给出一种基于多项式平方和(sum of squares,SOS)的非线性局部镇定控制方法.根据姿态系统结构特征,在此基础上,采用SOS结合S-procedure理论,得出相应的非线性局部可镇定条件.该条件可借助有效凸优化工具进行检验,当优化问题可解时,可构造非线性姿态控制器的解析解.最后,将文中方法应用于某型挠性卫星姿态控制.仿真结果表明,在实现大角度姿态快速机动的同时,有效抑制了挠性附件振动.国家自然科学基金资助项目(61374037);高等学校博士学科点专项科研基金资助项目(20110121110017

秦岭辛家山林区锐齿栎外生菌根真菌多样性

以秦岭辛家山林区锐齿栎为研究对象，通过野外调查结合形态学和分子生物学方法，观察和鉴定与其共生的外 生菌根真菌。结果确定了3 种子囊菌和48 种担子菌，分属于10 科14 属，其中毛革菌属Tomentella 是优势类群，丝伞盖 属1 Inocybe 1、Russula persicina、毛革菌属1 Tomentella 1、毛革菌属2 Tomentella 2、块菌属Tuber、绒盖牛肝菌属Xerocomus 是常见种，其余都为稀有种。两样地锐齿栎外生菌根真菌除丰富度指数外，Simpson 指数、Shannon 指数以及Pielou 均匀 度指数差异不显著；Jaccard 相似性指数和Sorenson 相似性指数分别为0.1154 和0.2069。</p