搜索结果: 151-165 共查到“知识库 工学”相关记录331306条 . 查询时间(7.245 秒)
融合MRI信息的PET图像去噪: 基于图小波的方法
正电子发射断层成像 磁共振成像 图小波 去噪
2024/1/16
正电子发射断层成像(Positron emission tomography,PET)是一种强大的核医学功能成像模式,广泛应用于临床诊断,但PET图像的空间分辨率低且含有噪声,有必要对PET图像进行去噪以提升PET图像的质量.随着PET/MR(Magnetic resonance)等一体化成像设备的出现,磁共振成像(Magnetic resonance imaging,MRI)的先验信息可用于PE...
在多无人机(Multi-unmanned aerial vehicles,Multi-UAVs)协同执行高层消防救援任务的场景中,室内复杂火场环境下路径规划是亟待解决难题之一.针对快速搜索随机树算法(Rapidly-exploring random tree,RRT)搜索区域受限、耗时较长、结果可行性差等问题,提出RRT森林算法.通过随机选取根节点、生成随机树、连接合并随机树,使高层消防多无人机在...
针对实际中某种工况滚动轴承带标签振动数据获取困难,健康指标难以构建及寿命预测误差大的问题,提出一种基于无监督深度模型迁移的滚动轴承剩余使用寿命(Remaining useful life,RUL)预测方法.该方法首先对滚动轴承全寿命周期振动数据提取均方根(Root mean square,RMS)特征,并引入新的自下而上(Bottom-up,BUP)时间序列分割算法将特征序列分割为正常期、退化期和...
基于加权矩阵的多维广义特征值并行分解算法
广义特征值分解 加权矩阵 并行分解 多维估计
2024/1/16
针对串行广义特征值分解算法实时性差的缺点,提出基于加权矩阵的多维广义特征值分解算法.与串行算法不同,所提算法能够在一次迭代过程中并行地估计出多维广义特征向量.平稳点分析表明:当且仅当算法中状态矩阵等于所需的广义特征向量时,算法达到收敛状态.通过对比相邻时刻的状态矩阵模值证明了所提算法的自稳定特性.所提算法参数选取简单,实际实施较为容易.数值仿真和实例应用进一步验证了算法的并行性、自稳定性和实用性。
Upgrading catalytic activity of NiO/CaO/MgO from natural limestone as catalysts for transesterification of coconut oil to biodiesel
Biodiesel Limestone Methyl ester PEG Vegetable oil
2023/12/19
Limestone was converted to high surface area CaO/MgO catalysts via calcination-hydration-dehydration (CHD) method for transesterification of coconut oil to biodiesel. Thermal?decomposition?at 900 degr...
Renewable UV-curable?polyester?methacrylate/cellulose nanocrystals composite?resin?for wood waterproof coating
UV-curable cellulose nanocrystals low viscosity composite star-shaped bio-based
2023/12/19
Low-viscosity UV-curable?resins?are widely used in industry as they allow for UV curing materials with reduced amounts of reactive diluents to adjust the viscosity. But their?mechanical properties?and...
Wood-inspired strategy to toughen transparent cellulose nanofibril films
Cellulose nanofibril film Wood-inspired strategy Lignosulfonic acid Toughness Transparency
2023/12/19
The simultaneous attainment of high strength and high toughness of transparent cellulose nanofibril (CNF) film can expedite its uses in advanced applications. In this work, a wood-inspired strategy is...
Hexachlorocyclotriphosphazene Functionalized Graphene Oxide as a Highly Efficient?Flame Retardant
flame-retardant thermal stability epoxy resin combustion
2023/12/19
A?flame-retardant?composite was synthesized through a simple graphene oxide functionalization route with hexachlorocyclotriphosphazene and p-phenylenediamine. Flame experiments conducted on the synthe...
Synthesis of a Novel?Flame Retardant?Containing Phosphorus, Nitrogen, and Silicon and Its Application in?Epoxy?Resin
Flame Retardant Epoxy Resin thermal stability mechanical properties
2023/12/19
A novel?flame retardant?(TDA) containing phosphorus, nitrogen, and silicon was synthesized successfully via a controllable ring-opening addition reaction between 1,3,5-triglycidyl isocyanurate, 9,10-d...
Fast pyrolysis of?pitch pine biomass?in a bubbling fluidized-bed reactor for bio-oil production
Pinus rigida pitch pine Thermogravimetric analysis Fast pyrolysis Bubbling fluidized-bed reactor Bio-oil
2023/12/18
The kinetic parameters for the pyrolysis of biomass of the pitch pine (Rigida pine?P. Mill) were examined by thermogravimetric analysis in the temperature range 25?°C to 700?°C, in which the main deco...
Lignocellulosic biomass based biorefinery: A successful platform towards circular bioeconomy
Lignocellulosic biorefinery Circular bioeconomy Lignin Cellulose Hemicellulose Value added products
2023/12/18
Biorefining of second-generation feedstock gains more attention to improve the living standards and promote circular bioeconomy. The biorefinery concept made an effort to make the environmentally sust...
Addition of Pine Rosin to Pectin bioplastic films for improved water resistance
Pine?Rosin Pectin Bioplastics Water resistance
2023/12/18
Pectin films were prepared by addition of different quantities of Rosin in order to test the effects of this natural hydrophobic polymer in increasing the water resistance of Pectin films. Scanning El...
Fully Bio-Based Polyhydroxyurethanes with a Dynamic Network from a Terpene Derivative and Cyclic Carbonate Functional Soybean Oil
fully bio-based non-isocyanate?polyurethanes dynamic covalent bond exchange self-healing recyclability shape memory
2023/12/18
Polyhydroxyurethanes (PHUs), polyurethanes with excellent properties, are cured without poisonous isocyanate. The carbamate groups in the structure can undergo bond exchange in the presence of amino g...
Recent advances in carbon-based nanomaterials for?flame retardant?polymers and composites
Graphene Polymer Flame retardant Nanocomposite carbon nanomaterials Flammability
2023/12/18
An urgent need is to reduce the?flammability?of polymers and manage their toxic thermal?decomposition?products. Although conventional halogenated, metallic and phosphorus-based?flame retardants?(FRs) ...
