90W-7Ni-3Fe纳米晶粉末的瞬时液相强化烧结特征

采用机械合金化(MA)制备了晶粒尺寸为8～18 nm的90W-7Ni-3Fe纳米晶粉末(MA粉末).将粉末注射成形,在1 480～1 500℃经3～5 min瞬时液相烧结.结果表明,采用瞬时液相强化烧结可以得到W晶粒为3～8 μm近全致密的细晶钨合金,显微组织为细小的球形W晶粒均匀地连续分布在纤维状粘结相中,烧结坯具有好的拉抻性能.长时间的传统液相烧结使球状W晶粒迅速粗化,而且密度和强度下降,但延伸率反而增加.在MA粉末中添加微量Y2O3后采用瞬时液相烧结,可以使合金抗拉强度提高到1 055 MPa,延伸率提高到16.5%.     

基于变论域模糊PI的永磁同步电机无传感控制

受到带通滤波器的影响,永磁同步电机(PMSM)脉振注入法中转子位置估算精度较低。为此,提出了一种基于变论域模糊PI的PMSM无传感控制法。利用变论域模糊的方法对转速环上固定的PI参数进行动态调节,达到减少系统延时、提高转子位置估算精度的目的。仿真的结果表明,变论域模糊PI能够用于转子位置估算,并且比传统PI无传感控制法减少了0.331°平均误差。     

Ovule Development and in Planta Transformation of Paphiopedilum Maudiae by Agrobacterium-Mediated Ovary-Injection

In this paper, the development of the Paphiopedilum Maudiae embryo sac at different developmental stages after pollination was assessed by confocal laser scanning microscopy. The mature seeds of P. Maudiae consisted of an exopleura and a spherical embryo, but without an endosperm, while the inner integument cells were absorbed by the developing embryo. The P. Maudiae embryo sac exhibited an Allium type of development. The time taken for the embryo to develop to a mature sac was 45-50 days after pollination (DAP) and most mature embryo sacs had completed fertilization and formed zygotes by about 50–54 DAP. In planta transformation was achieved by injection of the ovaries by Agrobacterium, resulting in 38 protocorms or seedlings after several rounds of hygromycin selection, corresponding to 2, 7, 5, 1, 3, 4, 9, and 7 plantlets from Agrobacterium-mediated ovary-injection at 30, 35, 42, 43, 45, 48, 50, and 53 DAP, respectively. Transformation efficiency was highest at 50 DAP (2.54%), followed by 2.48% at 53 DAP and 2.45% at 48 DAP. Four randomly selected hygromycin-resistant plants were GUS-positive after PCR analysis. Semi-quantitative PCR and quantitative real-time PCR analysis revealed the expression of the hpt gene in the leaves of eight hygromycin-resistant seedlings following Agrobacterium-mediated ovary-injection at 30, 35, 42, 43, 45, 48, 50, and 53 DAP, while hpt expression was not detected in the control. The best time to inject P. Maudiae ovaries in planta with Agrobacterium is 48-53 DAP, which corresponds to the period of fertilization. This protocol represents the first genetic transformation protocol for any Paphiopedilum species and will allow for expanded molecular breeding programs to introduce useful and interesting genes that can expand its ornamental and horticulturally important characteristics.     

基于卡尔曼滤波的电力虚假数据注入攻击检测方法

能源互联网的主体是基于状态估计下的电力系统。虚假数据注入攻击（FDIA）通过恶意篡改或注入电力数据,进而引发错误的状态估计结果。这种攻击方式存在引发大面积停电事故的风险,严重影响能源互联网的正常运行。在matpower 4.0中的IEEE-14节点系统上,利用以残差方程为基础的标准残差检测法和目标函数极值法,对FDIA进行了检测实验。提出了一种基于卡尔曼滤波的FDIA检测方法,并在MATLAB上进行了验证。实验结果表明,该方法可以在短时间内发现FDIA的发生。     

超超临界锅炉喷氨优化与调整

某厂超超临界燃煤火电机组已完成超低排放改造,实现烟尘、SO₂和NO_x排放浓度远低于10 mg/Nm³、35 mg/Nm³和50 mg/Nm³。但锅炉中脱硝系统氨逃逸过大,导致脱硝系统后面的烟道内空预器及低温省煤器堵塞严重,严重影响了机组运行安全。通过测量该锅炉SCR反应器出口NOx浓度及氨逃逸量等参数,基于实测数据分析对锅炉喷氨量进行优化调整,降低SCR反应器出口氨逃逸量,从而有效缓解空预器及低温省煤器的堵塞状况,保证机组的高效安全运行。     

基于UGII平台的注塑模具三维运动仿真

分析了典型注塑模具的结构及运动特点,介绍了注塑模具的运动仿真原理及其过程,最后基于UGII软件平台,以数码相机结构件模具为例,实现开模、脱模和合模的三维运动仿真,从而为注塑模具的设计提供了一定的可预见性,确保其结构的合理性。     

Role of Scaffolds,Subchondral, Intra-Articular Injections of Fresh Autologous Bone Marrow Concentrate Regenerative Cells in Treating Human Knee Cartilage Lesions: Different Approaches and Different Results

The value of bone marrow aspirate concentrates for treatment of human knee cartilage lesions is unclear. Most of the studies were performed with intra-articular injections. However, subchondral bone plays an important role in the progression of osteoarthritis. We investigated by a literature review whether joint, subchondral bone, or/and scaffolds implantation of fresh autologous bone marrow aspirate concentrated (BMAC) containing mesenchymal stem cells (MSCs) would improve osteoarthritis (OA). There is in vivo evidence that suggests that all these different approaches (intra-articular injections, subchondral implantation, scaffolds loaded with BMAC) can improve the patient. This review analyzes the evidence for each different approach to treat OA. We found that the use of intra-articular injections resulted in a significant relief of pain symptoms in the short term and was maintained in 12 months. However, the clinical trials indicate that the application of autologous bone marrow concentrates in combination with scaffolds or in injection in the subchondral bone was superior to intra-articular injection for long-term results. The tendency of MSCs to differentiate into fibrocartilage affecting the outcome was a common issue faced by all the studies when biopsies were performed, except for scaffolds implantation in which some hyaline cartilage was found. The review suggests also that both implantation of subchondral BMAC and scaffolds loaded with BMAC could reduce the need for further surgery.     

Formation of Proto-Kranz in C3 Rice Induced by Spike-Stalk Injection Method

Introduction of C4 photosynthetic traits into C3 crops is an important strategy for improving photosynthetic capacity and productivity. Here, we report the research results of a variant line of sorghum–rice (SR) plant with big panicle and high spikelet density by introducing sorghum genome DNA into rice by spike-stalk injection. The whole-genome resequencing showed that a few sorghum genes could be integrated into the rice genome. Gene expression was confirmed for two C4 photosynthetic enzymes containing pyruvate, orthophosphate dikinase and phosphoenolpyruvate carboxykinase. Exogenous sorghum DNA integration induced a series of key traits associated with the C4 pathway called “proto-Kranz” anatomy, including leaf thickness, bundle sheath number and size, and chloroplast size in bundle sheath cells. Significantly, transgenic plants exhibited enhanced photosynthetic capacity resulting from both photosynthetic CO₂-concentrating effect and improved energy balance, which led to an increase in carbohydrate levels and productivity. Furthermore, such rice plant exhibited delayed leaf senescence. In summary, this study provides a proof for the feasibility of inducing the transition from C3 leaf anatomy to proto-Kranz by spike-stalk injection to achieve efficient photosynthesis and increase productivity.     

平板类气体辅助注射成型产品的CAE模拟研究

通过建立具有代表性的平板类气体辅助注射成型产品模型,借助注塑成型CAE软件Moldflow对该模型进行了一系列分析模拟。通过对模拟结果数据的综合分析和数学处理,得到了气体注射参数对气道穿透长度的影响规律、气体注射参数设置及气道穿透长度预测公式。     

基于CAE的虚拟注射成型系统的研究和开发

研究了虚拟制造技术在注射成型过程中的应用 ,通过建立模架装配模型和模架的运动描述 ,开发出了基于CAE的虚拟注射成型原型系统 ,并将其与注射成型CAE系统HsCAE3D集成 ,取得了良好的效果。