基于LabVIEW的广义线性拟合在成本预测中的应用

成本预测在科研管理、生产管理等诸多方面有着广泛应用.使用图形化编程软件LabVIEW中“广义线性拟合Ⅵ”建立了成本预测的数学模型,实现了某产品的成本预测.结果分析表明,该方法是一种有效的数据处理方法,LabVIEW中不同方法的拟合函数使成本预测的实现与分析变得简单可靠.     

T-S模糊随机时滞系统的鲁棒控制

基于T-S模糊模型讨论具有参数不确定性和变时滞的随机非线性系统的时滞相关鲁棒控制器设计问题.基于Lyapunov稳定性理论、Schur补引理、Jensen积分不等式和自由权矩阵方法以及It公式,利用并行分布补偿(PDC)法,以线性矩阵不等式(LMI)的形式给出控制器存在的充分条件,以保证对所允许的不确定性,当LMIs可行时即可构造出相应的状态反馈控制律.最后,给出数值算例验证所提出方法的有效性.     

热喷涂技术提高输电线路悬垂金具耐磨性的应用研究

热喷涂技术对输电线路悬垂金具耐磨性的改良,是在基体表面喷涂不同组成成分的涂层.通过摩擦实验,并结合各涂层的成分分析和显微组织分析,最终找到最佳涂层方案,为提高输电线路悬垂金具的耐磨性提供了依据,为材料耐磨性的研究奠定了基础.     

LC40全轻页岩陶粒钢纤维混凝土三轴受压试验研究

利用大连理工大学的大型静、动真三轴试验机,对强度等级为LC40的全轻页岩陶粒混凝土和掺入钢纤维的钢纤维页岩陶粒混凝土进行了等比例三轴受压试验.试验中,观察了试件的破坏形态,测得了试件的三轴受压极限强度、塑性应变、峰值应变、总应变以及应力-应变曲线.结果表明,全轻页岩陶粒混凝土以及掺入钢纤维以后的钢纤维陶粒混凝土在三轴受压状态下,强度和变形较单轴受压有显著增大,并伴随有明显的平台流塑现象.因此,在工程设计中将应力平台流塑段强度及其对应的塑性应变作为轻骨料混凝土的设计强度和设计应变.最后,基于八面体应力空间建立了其相应的破坏准则,拉、压子午线与静水压力轴在高压应力区有交叉点,其破坏曲面是闭口的、子午线光滑、外凸的曲线,且钢纤维页岩陶粒混凝土的破坏包络面被相应的不掺钢纤维的页岩陶粒混凝土所包围.     

Accurate mirror-based camera pose estimation with explicit geometric meanings

An accurate closed form solution is proposed to estimate camera pose by several mirrored reference object images acquired via a planar mirror under different unknown poses. Compared with state-of-the-art methods, our method is more accurate when there are more than three images and has explicit geometric meanings. This method also properly handles cases in which some of the mirror poses are parallel. The central idea is to minimize an error metric based on all reflections of rotation, which enables the camera rotation to be estimated directly by SVD of sum of mirrored camera rotations. After that, the camera translation is computed by solving a large system of linear equations to minimize object space collinearity error. Both synthesized data and real data experiments show the advantages of our approach.     

壁湍流猝发事件检测与提取方法研究

在重力式低速水洞中完成了湍流边界层流场测量,并分别利用自相关方法和小波分析方法,对对数律区中一测点处的速度信号进行了分析。结果表明,自相关方法对于平均猝发周期的检测精度较高;小波分析方法可用于猝发事件的提取,但对平均猝发周期的检测精度较低。为此,进一步提出了一种同时基于自相关方法和小波分析方法的壁湍流猝发事件快速检测与提取方法,并总结了该方法的具体实施步骤。与原方法相比,该方法既能够精确检测湍流平均猝发周期,又能够提高猝发事件的提取精度。     

吸气式脉冲爆震发动机反传数值研究

采用小能量点火方法,对吸气式脉冲爆震发动机的反传现象进行了数值研究。获得了反传现象的形成及传播特性。结果表明,吸气式脉冲爆震发动机的反传可以分为压力反传和燃气反传两部分。两者都是由缓燃和回传爆震引起的,回传爆震占主导作用。反传燃气的影响区域小于反传压力,由于尾部膨胀波的作用,反传燃气在一定位置会停止向上游进气道流动。反传压力会一直向进气道上游传播,并且迫使流道内的流体也向上游流动。等截面流道内反传压力减小的速度较慢,应对进气道进行优化设计。     

自然环境中混凝土内湿度响应规律

基于饱和水汽压方程探讨了湿度采用相对湿度和水汽密度表达形式间的关联,并通过理论推导和现场实测法研究了自然环境中空气湿度变化和混凝土内不同深度处湿度响应规律,从而建立了自然环境湿度作用谱和混凝土内湿度响应谱模型.试验结果表明:所构筑的自然环境湿度作用谱和混凝土内湿度响应谱模型可用于描述环境湿度变化与混凝土内湿度响应规律.自然环境相对湿度曲线随时间发生周期性波动,而混凝土内湿度随距表层深度的增加而增大且一定深度处相对湿度短时间内基本恒定.与采用相对湿度表达形式相比,采用水汽密度表达形式可更好地定量表征不同环境条件下的环境湿度变化规律.     

Synthesis of Cu nano-particle in toluene used for conductive ink with a binder of polyurethane

Copper nanoparticles with a size of about 150 nm were prepared in toluene using oleic acid as protecting agent. The nanoparticles were used to prepare conductive Cu ink with a polyurethane binder. Oleic acid was used to prevent the nanoparticles from oxidization and agglomeration. The prepared Cu nanoparticles were characterized by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. The resistivity of the copper film on glass substrate that was prepared using Cu nanoparticle ink reached about 1.5× 10-4 2. cm-1 after it was annealed to 120 ~C. Both the nanoparticle ink and the films were characterized by XRD, fourier transform infrared （FT-IR）, and the thermogravimetry-differential scanning calorimetry instrument （TG- DSC）.     

Effect of straw mixing amount on mechanical properties of admixture-adding hollow block

The bonding mechanism between straw and concrete was analyzed through testing the compressive strength and flexural strength of hollow block, with different straw amount and different dosage and types of admixtures. The test results show that the mechanical properties of hollow blocks reduced after adding straws, and the more straws was added, the more hollow block density decreased. But adding Al₂(SO₄)₃ and CaCl₂ could improve the dense degree between rice straw and concrete. And when the proportion of straw mixing amount was 10%, the flexural strength of the early strength agent (2% Al₂(SO₄)₃, CaCl₂) added hollow block reached as maximal as 3.1 MPa, while the compressive strength was 9.1 MPa, consisting with the strength grade of common concrete hollow block MU7.5.