Benchmark-problem investigation for seismic response of a large-span cable-stayed bridge based on nonlinear stochastic optimal control

大跨度斜拉桥Benchmark问题的振动控制研究是当前国际结构控制研讨会的重要议题之一。以美国Bill Emerson Memorial斜拉桥第二阶段Benchmark模型为研究对象,在非线性随机动力学与控制的拟哈密顿理论体系框架下,运用基于随机平均法和随机动态规划原理的非线性随机最优(NSO)控制策略,对地震作用下的Benchmark模型进行MATLAB仿真分析。将最优控制力和性能评价指标与线性二次型Gauss(LQG)控制的计算结果进行对比,得出非线性随机最优控制策略能够更加有效地抑制斜拉桥的地震响应,提高结构的动力稳定性和抗震能力,具有更好的控制效果,对实际桥梁工程的振动控制具有较强的指导意义和适用价值。Investigation of vibration control for benchmark problems on large-span,cable-stayed bridge is one of the most important research topics in the current International Symposium on Structural Control. This paper studied secondstage benchmark problems on the Bill Emerson Memorial cable-stayed bridge. In terms of Hamiltonian theory for nonlinear stochastic dynamics and control, the benchmark model under seismic excitations was investigated using MATLAB simulation analysis,based on the stochastic averaging method and stochastic dynamic-programming principle. Comparison of analysis results for optimal forces and performance-evaluation indices between the nonlinear stochastic optimal( NSO)control strategy and the linear quadratic Gaussian( LQG) control strategy revealed that the former control strategy mitigates the seismic response of the cable-stayed bridge more effectively than the latter,thereby enhancing structural dynamic stability and earthquake resistance. In conclusion,the NSO control strategy demonstrates better control effect and presents instructive references and practical significance for vibration control of bridge-engineering applications.福建省青年人才项目(2008F3100

1930年代中国政治史研究 : 中国共産党の危機と再生

2007年7月第1版 2007年7月第1次印刷原著(勁草書房, 2002)の翻

AERODYNAMIC MOMENTS CONTROL OF WING MODEL USING PLASMA JET

为考察火花放电等离子体射流控制机翼气动力矩的效果,在NACA0021平直机翼模型上安装火花放电等离子体射流发生器,通过改变射流发生器安装位置、射流角度及加载电参数,研究其控制机翼模型气动力矩的性能及机理。在NACA0021机翼模型近前缘处,布置2个火花放电等离子体射流发生器,采用气动力测量技术,在来流风速为20 m/s时测得,攻角-4°~10°时,滚转力矩系数最大减小了0.0024,攻角为12°~16°时,滚转力矩系数最大增加了0.0021;偏航力矩系数最大减小了0.00097。实验研究结果表明:等离子体射流可改变机翼模型横航向气动力矩,并可通过改变射流角度和加载电压频率调节等离子体射流控制横向气动力矩的效果。To investigate the control effect of Spark Discharge Plasma Jets(SPJs) on the aerodynamic moments of a wing, SPJ generators were used for active flow control experimental study on an NACA0021 straight wing model. The location of SPJ generators along the chord of the airfoil, the jet flow direction relative to the chord, and the driving voltage parameters were changed to research the control effect and mechanism of SPJ generators on the aerodynamic moments of a wing model. The aerodynamic moments were measured with a six-component balance at a wind speed of 20 m/s. Two SPJ generators, arranged near the leading edge, reduced the rolling moment coefficient by a maximum of 0.0024 for angles of attack-4°~10°, but increased the rolling moment coefficient by a maximum of 0.0021 for angles of attack 12°~16°. The yaw moment coefficient was reduced by a maximum of 0.00097. The results show that aerodynamic moments control of wings can be realized using SPJs. The control effect of SPJs on the aerodynamic moments is changeable by adjusting the driving voltage frequency and the jet flow direction relative to the chord.航空科学基金项目(20141368007);; 福建省自然科学基金项目(2010J01014

基于等离子体合成射流的飞翼布局模型主动流动控制风洞实验研究

为探究等离子体合成射流对三维模型的流动控制效果和机理,在中等展弦比飞翼布局模型前缘布置等离子体合成射流激励器开展低速风洞实验研究。通过六分量天平测力,考察沿弦向、展向不同分布位置的等离子体合成射流对飞翼模型气动力和气动力矩的作用;采用PIV(Particle Image Velocimetry,粒子图像测速)测量模型表面流场分布,研究等离子体合成射流流动控制机理。结果表明:在飞翼模型单侧布置等离子体合成射流,能够有效改善其气动特性,并能产生附加的滚转力矩,滚转力矩系数变化量最高达到0.009;在飞翼模型左右弦布置等离子体合成射流,能显著增强飞翼模型横向稳定性,滚转力矩系数波动范围减小66.7%。沿弦向,等离子体合成射流位置离前缘越近,控制效果越好,距前缘0mm的激励器控制效果最好;沿展向,布置的等离子体合成射流越多,对模型的升力特性改善作用越明显,布置方式以均布为优。在失速迎角前后,等离子体合成射流的流动控制机理不同:在小迎角下,等离子体合成射流在前缘起到了使转捩提前的作用;在失速迎角附近,则加速了分离区的流动、减小了分离区厚度。国家自然科学基金项目(51707169)中航工业创新基金产学研项目(cxy2013XD28)福建自然科学基金项目(2019J01042)厦门大学校长基金项目(20720170057

Wood Anatomy Characteristics of 6 Mangrove Species of Sonneratia and Their Application

应用光镜及扫描电镜对生长在热带、亚热带海岸潮间带的 6种海桑属红树植物的次生木质部进行了解剖学研究表明 :海桑属 6种红树植物的次生木质部具有导管直径小 ,导管分布频率高 ,复孔率高 ,导管壁厚和纤维壁较厚且具次生加厚 ,木薄壁组织缺乏或稀少等与环境相适应的特点。海桑属 6种红树植物的数量特征还表明 :海桑、无瓣海桑、卵叶海桑的木材可能适合造纸。The study reveals that the secondary xylem of 6 mangrove species of Sonneratia possesses the following characteristics:the diameter of vessel is small,the distribution frequency of vessel is high,the reperforating rate is high,the wall of vessel is thick,the wall of fibre is relatively thick and the wood parenchyma is short or sparse,whish is suitable with the environment.The quantitative feature of 6 mangrove species of Sonneratia also indicates that the wood of S.caseolaria,apetalous sonneratia and ovate-leaf sonneratia is probably suitable for paper-making.国家自然科学基金资助项目! (495 76 2 95

Developing On-site,Quick Screening Platform for Artificial Pigments in Food Using Surface-enhanced Raman Spectroscopy

已有研究表明食品加工过程中添加的人工合成色素不仅不能提供营养物质,而且可能是导致小儿多动症的来源之一,影响儿童智力发育.基于表面增强拉曼光谱(SERS)原理和便携式拉曼光谱仪,提出了一种非定向的现场快速筛查方法.该方法只需对疑似含有人工合成色素的固体或液体状食品样品进行简单前处理,即可进行SERS检测.样品前处理和检测的总时长不超过15 min,检出质量浓度在1 mg/L水平,可有效满足政府职能部门的现场执法需求.除具有快速、方便、灵敏度高等特点之外,该检测方法的最大优势在于实现了未知样品的现场非定向测试:在同一种前处理过程和检测方法下,可对食品中常添加的亮蓝、胭脂红、日落黄、柠檬黄、苋菜红和诱惑红6种人工合成色素进行快速鉴定和半定量分析.As widely used additives in food processing,artificial pigments have no any nutrition but are potential sources of hyper-activity and affect the intellectual development of children.On the basis of surface-enhanced Raman spectroscopy( SERS) and portable Raman instrument,we developed a non-targeting,on-site and quick screening platform for artificial pigments in food matrix. SERS measurement could be carried out after the food matrix( either in solid or liquid states) being simply pretreated for 15 min.The detectable concentration is as low as 1 mg / L,a level meeting the demand of the on-site enforcement by the government.Besides the advantages of quick,easy-on-going,and high sensitivity,the most distinguished point of SERS is the non-targeting qualitative on-site detection for the typical pigment additives,including brilliant blue,carmine,sunset yellow,lemon yellow,amaranth and allura red,et al.,while both the pretreatment procedure and the SERS detection remain the same.国家自然科学基金(21473140);; 福建省高校产学合作项目(2016Y4012);; 中央高校基本科研业务费专项(2072016011

Experimental Study on Accelerating the Gas Flow Induced by Planar Coil Electromagnetic Coupling Surface DBD Gas Discharge

为了提高典型沿面dbd平板激励器诱导气流速度,通过实验研究了典型dbd平板激励器表面的磁场分布,提出了在dbd平板激励器的上、下电极之间夹进平面线圈,运用电磁耦合原理增强等离子体激励器放电效果,从而加速dbd等离子体诱导气流的方法。探究了不同结构参数的电感线圈产生的电磁耦合作用对大气压下平板式dbd等离子体激励器放电加强的效果,以及夹进平面线圈后加载电源的电压和频率对dbd放电的影响,并利用粒子图像测速技术测量了电磁耦合作用下典型dbd等离子体诱导气流流场,考察了其中电磁耦合对加速诱导气流的作用。实验结果表明,运用电磁耦合作用可在一定程度上增强等离子体激励器的放电效果,一些电感线圈产生的电磁耦合作用可显著改善dbd等离子体诱导气流的连续性和加厚流场区域。To accelerate the flow induced by typical surface DBD actuator, we studied the magnetic distribution on the surface of a typical DBD actuator qualitatively through experiments.We proposed a method that inductance coils between the upper electrode and the lower electrode were installed to enhance the discharge and increase the flow speed due to the electromagnetic coupling applied to the plasma actuator.Inductance coils with different structure parameters which could create various electromagnetic coupling impacts were used to improve the DBD plasma discharge.Furthermore, we measured the induced flow charts of DBD plasma actuators with electromagnetic coupling using the particle image velocimetry to study the electromagnetic coupling impact on increasing the flow speed induced by DBD plasma.The results show that, by applying electromagnetic coupling to the typical DBD plasma actuator, its discharge can be improved and the airflow induced by the plasma can be accelerated by some kinds of inductance coils, improving the induced flow in both continuity and thickness.福建省自然科学基金(2010J01014)~

Developing fast laboratory screening platform for sulfate dioxide in food by surface-enhanced Raman spectroscopy

基于表面增强拉曼光谱(SERS)的指纹图谱的高能量分辨率,以位于~630; cm~(-1)亚硫酸根的特征峰为定性和定量依据,本文开展了食品中滥用和非法添加二氧化硫的直接检测研究:一种检测流程实现了不同食品基质中二氧化硫的; 高灵敏检测,最低检出浓度达1 mg; kg~(-1)的水平.针对实际样本的传统蒸馏法前处理流程的一些不足以及SERS检测的指纹图谱优势,本文进行了三方面显著改进:; (1)碳酸钙和沸石取代氮气以提高二氧化硫的挥发提取效率; (2)草酸取代盐酸酸化蒸馏溶液,以有效避免挥发性强酸对操作环境的危害;; (3)氢氧化钠溶液代替乙酸铅溶液作为吸收液,以防止二次污染.环境友好、灵敏度高和不受基质干扰等特点使得本方法有望取代经典蒸馏法和比色法,用于食品; 中非法添加二氧化硫类添加剂的快速高效筛查.The direct detection of sulphur dioxide has been realized in various; food matrixes with high sensitivity and high selectivity, on the basis; of the integration of the high energy resolution of the finger-print; spectrum of surface-enhanced Raman spectroscopy and the universal but; easy-on-going pretreatment procedure. The characteristic peak of sulphur; dioxide at ~630 cm~(-1) was applied as the qualitative and quantitative; standard, which displayed a lowest detectable concentration at the 1 mg; kg~(-1) level for the spiked food samples. The key point of the high; sensitivity and selectivity is the effective pretreatment born out of; the standard distillation one, which has been improved in the three; parts. (1) Using CaCO_3 and Zeolite instead of N_2 gas as the bubbling; reagent. (2) Using oxalic acid as the acidic distillation solution to; eliminate the hazards from acid volatilization, such as hydrochloric; acid. (3) Using diluted sodium hydroxide solution as the absorption; reagent instead of lead acetate solution to avoid the secondary; pollution. With the three distinguished advantages of environment; friendly, high sensitivity and free of matrix interference, the proposed; method has great potential to replace the traditional ones for the fast; screening of the illegal or abused sulphur dioxide in food.国家自然科学基金; 福建省高校产学合作项目; 中央高校基本科研业务费专项资

甲状腺相关眼病患者眼眶脂肪抵抗素的表达

【目的】通过检测抵抗素在甲状腺相关眼病患者及对照组眼眶脂肪组织和脂肪细胞中的表达，为进一步探讨抵抗素与甲状腺相关眼病的相关性打下基础。【方法】通过体外原代培养获得前脂肪细胞，前脂肪细胞在分化液的作用下转化为成熟脂肪细胞。用RT-PCR法检测眶脂肪组织、前脂肪细胞及成熟脂肪细胞中抵抗素mRNA的表达，并进行免疫组化检测抵抗素蛋白的表达。【结果】前脂肪细胞中无抵抗素mRNA及蛋白的表达。成熟脂肪细胞及眶脂肪组织中有抵抗素mRNA及蛋白的表达。免疫组化结果显示抵抗素蛋白位于成熟脂肪细胞胞浆中。【结论】甲状腺相关眼病患者眶脂肪中抵抗素mRNA及蛋白表达丰富，说明甲状腺相关眼病患者眶脂肪增多是因成熟脂肪细胞所占比例增加、脂肪细胞分化增强所致

大鼠脑缺血/再灌注过程中脑型葡萄糖转运体在缺血半影区的表达

【目的】研究大鼠局灶性脑缺血不同缺血时间和不同再灌注时间的脑梗死体积比、皮质半影区脑型 葡萄糖转运体(GLUT1、GLUT3) 转录水平和蛋白水平的表达。【方法】用线栓法复制大鼠局灶性脑缺血模型, 用 Kontron IBAS2.5 全自动图像分析系统检测脑梗死体积比; 剥取缺血半影区皮质组织, 采用逆转录- 聚合酶链反应 (RT-PCR) , 测定GLUT1、GLUT3 mRNA 水平的变化; 用免疫组织化学半定量测定GLUT1、GLUT3 蛋白水平的变 化。【结果】脑缺血1 h 后再灌注(MCAO1h/R) 较缺血3 h 再灌注(MCAO3h/R) 脑梗死体积明显减小。MCAO1h/R 组GLUT1、GLUT3 mRNA 缺血后升高, 24 h 到达高峰, 但GLUT1 比GLUT3 提前升高, 且升高的幅度更大。 MCAO3h/R 组GLUT1 在3 h 开始升高, 24 h 到高峰; GLUT3 在缺血3 h 有一下降点, 然后升高, 24 h 到高峰, 一 周恢复正常, 同样GLUT1 比GLUT3 提前升高, 且升高的幅度更大。MCAO3h/R 组较MCAO1h/R 组的GLUT1、 GLUT3 峰值低。GLUT1、3 蛋白水平的表达与mRNA 相符合。【结论】GLUT1、GLUT3 在缺血半影区的表达上调, 可 能是机体对缺血/再灌注损伤的保护性反应