植物叶片中花青素的分析与研究

本文提供了一种简单快速测定植物叶片中花青素含量的分光光度方法,对美人梅和黄栌叶片中的花青素的提取和测定进行了研究,为开发和利用天然色素提供了一种有效的实验方法。     

基于Pro/E渐消失曲面的构建

渐消失曲面,是沿主体曲面走势延伸至某处自然消失,它能体现速度感和流畅感,是曲面增强设计感的一种常用手段。渐消失曲面的构建:首先是将规划渐消失曲面范围内的原曲面裁剪掉;然后在渐消失曲面范围内创建出分离面;最后通过原曲面和分离面之间创建出的曲面裁剪分离面。     

关于花青素在小浆果加工过程中的稳定性研究

影响花青素物理化学性质的因素很多,包括PH值、光照强度、金属离子、温度以及其自身的构造等,在综合考虑这些因素的前提下,研究小浆果加工的每个工序流程,分析其对花青素稳定性的利弊,从而在小浆果加工中改进流程增加花青素的稳定性,尽可能的保留其营养成分。     

频率添加奇异值分解算法及其在故障特征提取中的应用

针对奇异值分解(Singular value decomposition,SVD)的频率分离问题,研究了 SVD对单个频率的分离条件,发现SVD分离单个频率的效果取决于各频率的幅值差异.若不同频率的幅值很接近,则SVD就不能分离这些频率,由此提出一种频率添加SVD算法.为了提取原信号中的特征频率,先对原信号添加该频率的理想正弦信号,使原信号中该频率成分和其他频率的幅值产生差异,从而实现对该频率成分的提取,从理论上证明此算法的可行性.仿真信号处理实例表明,即使对于频率值非常接近的两个频率,频率添加SVD算法亦可将它们准确分离,分离结果波形误差小,克服了原来SVD频率分离算法的缺陷.将此算法应用某转子系统的振动特征提取,准确地提取到振动的高阶倍频,发现高阶倍频振幅的周期性波动特征,并分析这种振幅周期性波动的原因.     

岩茶水库岭肉桂中原花青素的高效液相色谱-串联质谱法分析

采用高效液相色谱 串联质谱技术,多重反应监测模式对岩茶水库岭肉桂样品中的原花青素组分进行定性和定量分析。采用Waters SunFire-C₁₈柱（150 mm×2.1 mm×5 μm）,流动相为乙腈和0.1%甲酸水溶液,流速0.25 mL/min,柱温25 ℃,进样量3 μL。结果表明,岩茶水库岭肉桂样品中的原花青素主要有儿茶素、表儿茶素、表儿茶素没食子酸酯和原花青素B₂,其回归方程和相关系数分别为： y₁=642.48x-63.693,r=0.999 5;y₂=550.45x+10.386,r=0.999 6;y₃=2 261.5x-1 320.0,r=0.999 5和 y₄=4 598.5x-4 079.0,r=0.999 5;其线性范围为5.00～150.00 mg/L。方法的加标回收率为93.9％～108.0％,变异系数小于7.53％,最低检出限为0.005 5～0.013 2 μg/g。     

紫甘薯的有益成分及其提取纯化方法研究

紫甘薯富含花青素,具有非常高的利用价值。现对紫甘薯中花青素的提取方法做了分析,对各种纯化提取方法进行了详细比较,并提出了目前花青素纯化方法存在的问题,指明了纯化技术未来的发展方向。     

一种基于SST-MOM的改进形态成分分析算法及其应用

形态成分分析(MCA)是最新提出的一种基于稀疏表示的信号和图像分解(分离)方法,其扩展算法GMCA(Generalized MCA)可用于超定和欠定情形的盲源分离。为了降低GMCA算法中重构信号的均方差,提高分离信号的精度,将半软阈值函数和MOM阈值更新机制相结合,提出了SST-MOM(Semi-soft Thresholding MOM)阈值更新策略,仿真结果表明,新算法较原GMCA算法提高了分离信号的信噪比,将其应用于齿轮箱复合故障诊断中,有效地识别出了两路观测信号中的3种故障,表明了该算法的有效性。     

简介JB/T 11006—2010《空气分离设备 产品型号编制方法》

阐述新制定的机械行业标准JB/T1 1006—2010《空气分离设备产品型号编制方法》与原国家标准GB/T 10607—2001《空气分离设备产品型号编制方法》主要差异。     

基于UHPLC-LTQ-Orbitrap的发酵玫瑰茄化学成分筛查和研究

本研究采用高效液相色谱-线性离子阱-静电场轨道质谱（UHPLC-LTQ-Orbitrap MS）技术,在电喷雾负离子模式下,对玫瑰茄水提液及其发酵液中有机酸类、黄酮类、花青素类和木质素类化学成分进行分析鉴定。选取Agilent Zorbax SB C18色谱柱（250 mm×4.6 mm×5 μm）,以0.1%甲酸水溶液（A）-甲醇（B）为流动相,流速1 mL/min,梯度洗脱分析。根据高分辨质谱提供的精确相对分子质量数据和多级质谱碎片离子,获取目标化合物的相对分子质量和结构信息。结合保留时间、对照品及相关参考文献等信息,共筛选鉴定出41种化合物,包括34种有机酸类、4种黄酮类、2种花青素类以及1种木脂素类。结果表明,玫瑰茄发酵前后,其活性成分的种类及含量均呈现不同程度的变化,该方法阐明了玫瑰茄发酵前后化学成分的变化,可为玫瑰茄的进一步研究提供参考。     

地铁车辆牵引节点与中心销拆卸工装的优化设计与运用

原牵引中心节点与牵引中心销分离工装在使用时存在拉杆变形、挂钩滑脱以及拉杆与底盘连接不稳定等问题,继续使用会给现场工作人员带来安全隐患,同时会严重影响地铁电客车架和大修生产工期。通过对原工装进行优化设计和制作,可提高地铁车辆牵引中心节点与牵引中心销的分离作业质量和作业效率,有效保障工作人员的作业安全。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.