INS／GPS紧耦合系统中的模糊自应SRUKF算法

为解决惯性导航系统(INS)与全球定位系统(GPS)紧耦合中标准无迹卡尔曼滤波(UKF)由于计算舍入误差使协方差矩阵负定和实际应用中由于量测噪声时变而严重影响滤波精度的问题,提出了基于模糊控制理论的自适应平方根无迹卡尔曼滤波(NASRUKF)算法.该算法在滤波过程中不是直接计算协方差矩阵,而是计算协方差矩阵的平方根,从而可以保证协方差矩阵的非负定性;然后根据实时得到的量测信息的实际方差与理论方差的比值,通过设计的模糊控制系统(FCS)实时调整量测噪声矩阵.实验表明:该算法对时变的噪声具有很好的自适应性,相比于UKF算法具有更高的精度并使得系统具有更高的稳定性和鲁棒性.     

金属Al电子结构与热力学性质的第一性原理计算

针对金属Al的电子结构与热力学性质,采用基于密度泛函理论的第一性原理以及CASTEP软件进行了理论计算,得到了金属Al的平衡晶格常数、相关弹性系数、电子能带、态密度、声子谱、声子态密度以及相关热力学参数,并对计算结果进行了理论分析.结果表明,金属Al具有明显的导电特性与良好的塑性.金属Al具有3条声学支波色散曲线与一个声子态密度峰.随着温度的增加,熵、焓均增加,而自由能减少.热容量随着温度的增加而迅速增加,当温度达到500 K后,热容量几乎不变,所得结论与物理规律相符合.     

Improved visible transparency of SIO<Subscript>2</Subscript>/ZNO:AL /CEO<Subscript>2</Subscript>-TIO<Subscript>2</Subscript>/SIO<Subscript>2</Subscript> multilayer films with high UV absorption and infrared reflection rate

New visible transparent, UV absorption, and high infrared reflection properties have been realized by depositing multilayer SiO₂/ZnO: Al/CeO₂-TiO₂/SiO₂ films onto glass substrates at low temperature by radio frequency magnetron sputtering. Optimum thickness of SiO₂, ZnO: Al (ZAO) and CeO₂-TiO₂ (CTO) films were designed with the aid of thin film design software. The degree of antireflection can be controlled by adjusting the thickness and refractive index. The outer SiO₂ film can diminish the interference coloring and increase the transparency; the inner SiO₂ film improves the adhesion of the coating on the glass substrate and prevents Ca²⁺, Na⁺ in the glass substrate from entering the ZAO film. The average transmittance in the visible light range increases by nearly 18%-20%, as compared to double layer ZAO/CTO films. And the films display high infrared reflection rate of above 75% in the wavelength range of 10-25 μm and good UV absorption (> 98%) properties. These systems are easy to produce on a large scale at low cost and exhibit high mechanical and chemical durability. The triple functional films with high UV absorption, antireflective and high infrared reflection rate will adapt to application in flat panel display and architectural coating glass, automotive glass, with diminishing light pollution as well as decreasing eye fatigue and increasing comfort.     

Electrospinning and rheological behavior of poly (vinyl alcohol)/collagen blended solutions

Poly(vinyl alcohol)/collagen (PVA/COL) micro-nanofibers were successfully prepared by electrospinning process. Water, green, and non-toxic was used as the solvent. The electrospun mats consisted of micro-nanoscale fibers with mean diameter ranging from approximately 363 nm to 179 nm. It was observed that the mean diameters of PVA/COL electrospun fibers decreased with increasing collagen content. The effects of PVA/COL blending ratio on the rheological behavior of PVA/COL blended solutions were investigated by rotate rheometer. It was found that PVA/COL blended solutions behaved as Non-Newtonian fluids. With increasing collagen content, the Non-Newtonian index (n) of PVA/COL blended solutions decreased. Meanwhile, a linear relationship was found between the Non-Newtonian index (n) and the mean diameters of the PVA/COL micronanofibers. The chemical structures of PVA/COL electrospun fibers were also characterized by FTIR.     

An invariant interest point detector under image affine transformation

For vision-based mobile robot navigation, images of the same scene may undergo a general affine transformation in the case of significant viewpoint changes. So, a novel method for detecting affine invariant interest points is proposed to obtain the invariant local features, which is coined polynomial local orientation tensor(PLOT). The new detector is based on image local orientation tensor that is constructed from the polynomial expansion of image signal. Firstly, the properties of local orientation tensor of PLOT are analyzed, and a suitable tuning parameter of local orientation tensor is chosen so as to extract invariant features. The initial interest points are detected by local maxima search for the smaller eigenvalues of the orientation tensor. Then, an iterative procedure is used to allow the initial interest points to converge to affine invariant interest points and regions. The performances of this detector are evaluated on the repeatability criteria and recall versus 1-precision graphs, and then are compared with other existing approaches. Experimental results for PLOT show strong performance under affine transformation in the real-world conditions.     

Comparisons of Fly Ash and Deposition Between Air and Oxy-FuelCombustion in Bench-Scale Fluidized Bed with Limestone Addition

In Oxy-fuel circulating fluidized bed, the residual CaO particles may react with high concentration of CO₂ in flue gas to form bonded deposit on heat transfer surfaces in backpass when limestone is used as a sorbent to capture SO₂.In this paper, experiments were designed on ash deposition in a bench-scale fluidized bed under oxy-fuel and air atmosphere. A novel ash deposit sampling probe was used to simulate the tubes of tail surfaces. The chemical composition of fly ash and ash deposit from both air-firing and oxy-fuel firing cases were analyzed by Inductively Coupled Plasma-Atomic Emission Spectrometry(ICP-AES) and Scanning Electron Microscopy(SEM), respectively. The degrees of carbonation reaction of ash deposits were measured by Thermo Gravimetric Analysis. The results showed that there are distinct differences in fly ash deposition rate between oxy-fuel and air firing cases, and oxy-fuel combustion with limestone addition can affect chemical composition of fly ash and ash deposit, especially for elements of Ca, Na, K, and S. However, the carbonation reaction degree of ash deposits is found weak, which is due to the relatively low CaO content in ash deposit or not long enough of the sampling time.[JP]     

频率响应法研究噻吩在CeY分子筛上的吸附行为

以NaY、液相Ce离子交换改性的Y型分子筛(L-CeY)为研究对象,运用N2吸附、XRD、NH3-TPD和Py-FTIR等实验方法表征两种Y型分子筛的物化性能。采用频率响应技术(FR)和智能重量分析仪(IGA)研究噻吩在两种分子筛上的吸附行为,并考察噻吩在稀土离子改性Y型分子筛上的不同吸附作用模式。结果表明,频率响应技术能够有效识别分子筛孔道内发生的不同传质过程。噻吩在NaY分子筛上的吸附行为较为简单,存在孔道吸附和π电子相互作用两种吸附过程;而在L-CeY分子筛上吸附行为较为复杂,同时存在孔道吸附和"S-M"吸附等多种吸附过程,另外,在高温条件下,还存在复杂的催化反应过程。     

半潜型风电浮式基础运动特性试验研究

针对5 MW海上风机半潜型浮式基础的运动特性进行模型试验研究,考虑系泊线、塔柱及叶片,采用1∶50的比例制作浮式基础在内的风机系统模型,设计加工了人工风场产生风载荷。通过无接触式光学六自由度三维运动测量仪测量模型在风浪联合作用下的运动响应,测试不同海况、不同风速下的风机系统运动响应,得到了风机系统的固有运动特性,幅频响应特性,以及定常风对浮式风机纵荡、垂荡、纵摇的影响规律。通过实验结果,评估了风机浮式基础在不同海况下的发电作业和生存能力。     

建德市河流生态治理的对策

建德市河流治理存在着污染严重,生态环境恶化、硬化过度,生态退化严重、截弯取直,影响行洪安全、管理滞后,破坏生物多样性等问题,对此应更新理念,强化河道综合整治;顺应河势,保持河道的自然通畅;降低硬化,建设河道生态型护岸;强化措施,落实河道长效管理机制等.     

装备维修保障可持续发展基本问题研究

从可持续发展视角,研究了装备维修保障可持续发展基本问题,界定了装备维修保障可持续发展的内涵,描述了装备维修保障可持续发展的主要目标,分析了装备维修保障可持续发展的立足点和动力源,总结了装备维修保障可持续发展对价格机制创新的内在要求。