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In the early design stage, automotive modeling should both meet the requirements of aesthetics and engineering. Therefore, a vehicle CAD (computer aided design) model that can be easily adjusted by feedbacks is necessary. Based on CE-Bézier surface, this paper presents a set of algorithms for parametric segmentation and fairing surface generation in a car model. This model is defined by a simplified automotive template and relevant control points, shape parameters and segmentation parameters, which can be modified to alter the car form efficiently. With this model and the corresponding adjustment method, more than fifty various vehicle models are established in this research according to different parameters. And two methods for calculating similarity index between car models are constructed, which are suitable for brand design trend analysis and modelling design decisionmaking. 相似文献
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目的: 探讨自身免疫性溶血性贫血(AIHA)患者外周血中调节性B细胞(Bregs)的表达及其在该病发病中的意义。方法:选择16例自身免疫性溶血性贫血患者和14例健康志愿者为研究对象,用流式细胞术分析外周血CD19+IL-10+调节性B细胞及CD19+CD24hiCD27+调节性B细胞的表达;ELISA方法检测培养上清液中IL-10的水平。结果:自身免疫性溶血性贫血患者外周血中CD19+IL-10+调节性B细胞、CD19+CD24hiCD27+调节性B细胞的表达分别为(1.27±0.39)%、(9.85±2.18)%,健康志愿者组分别为(2.92±0.71)%、(26.47±4.31)%,两组比较差异有统计学意义(P<0.05);自身免疫性溶血性贫血患者细胞培养上清中IL-10的水平低于健康志愿者组(P<0.05)。结论:自身免疫性溶血性贫血患者外周血中CD19+IL-10+调节性B细胞及CD19+CD24hiCD27+调节性B细胞比例降低,提示调节性B细胞可能参与自身免疫性溶血性贫血的发病过程。 相似文献
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Min-Kyung Kang Soo-Il Kim Su Yeon Oh Woojin Na Young-Hee Kang 《International journal of molecular sciences》2020,21(22)
Podocyte injury inevitably results in leakage of proteins from the glomerular filter and is vital in the pathogenesis of diabetic nephropathy (DN). The underlying mechanisms of podocyte injury facilitate finding of new therapeutic targets for DN treatment and prevention. Tangeretin is an O-polymethoxylated flavone present in citrus peels with anti-inflammatory and antioxidant properties. This study investigated the renoprotective effects of tangeretin on epithelial-to-mesenchymal transition-mediated podocyte injury and fibrosis through oxidative stress and hypoxia caused by hyperglycemia. Mouse podocytes were incubated in media containing 33 mM glucose in the absence and presence of 1–20 μM tangeretin for up to 6 days. The in vivo animal model employed db/db mice orally administrated with 10 mg/kg tangeretin for 8 weeks. Non-toxic tangeretin inhibited glucose-induced expression of the mesenchymal markers of N-cadherin and α-smooth muscle actin in podocytes. However, the reduced induction of the epithelial markers of E-cadherin and P-cadherin was restored by tangeretin in diabetic podocytes. Further, tangeretin enhanced the expression of the podocyte slit diaphragm proteins of nephrin and podocin down-regulated by glucose stimulation. The transmission electron microscopic images revealed that foot process effacement and loss of podocytes occurred in diabetic mouse glomeruli. However, oral administration of 10 mg/kg tangeretin reduced urine albumin excretion and improved foot process effacement of diabetic podocytes through inhibiting loss of slit junction and adherenes junction proteins. Glucose enhanced ROS production and HIF-1α induction in podocytes, leading to induction of oxidative stress and hypoxia. Similarly, in diabetic glomeruli reactive oxygen species (ROS) production and HIF-1α induction were observed. Furthermore, hypoxia-evoking cobalt chloride induced epithelial-to-mesenchymal transition (EMT) process and loss of slit diaphragm proteins and junction proteins in podocytes, which was inhibited by treating submicromolar tangeretin. Collectively, these results demonstrate that tangeretin inhibited podocyte injury and fibrosis through blocking podocyte EMT caused by glucose-induced oxidative stress and hypoxia. 相似文献
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Multimedia Tools and Applications - Understanding human emotions through facial expressions is key enabling technology for interactive robots. Most approaches of facial expression recognition are... 相似文献
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采用X射线衍射仪、金相显微镜、分离式霍普金森杆和扫描电镜等手段研究了Ti-20Zr-20Al钛合金在动态压缩条件下的微观结构、力学性能和断裂机制。结果表明,Ti-20Zr-20Al铸态合金由Zr基体相和TiAl/Ti3Al针状相组成; 随着应变率增加,合金的抗压强度增加,失效应变显著增加; Ti-20Zr-20Al合金的断裂机制为解理断裂; 随着应变率增加,试验压缩断裂后碎片总数增大,平均粒径减小。采用DID模型模拟的材料碎片尺度与实验结果比较吻合,Grady模型与实验结果的偏差较大。 相似文献
70.
Zhimei Zheng Taixiu Liu Qibin Liu Jing Lei Juan Fang 《International Journal of Hydrogen Energy》2021,46(38):19846-19860
Solar thermochemical hydrogen production with energy level upgraded from solar thermal to chemical energy shows great potential. By integrating mid-and-low temperature solar thermochemistry and solid oxide fuel cells, in this paper, a new distributed energy system combining power, cooling, and heating is proposed and analyzed from thermodynamic, energy and exergy viewpoints. Different from the high temperature solar thermochemistry (above 1073.15 K), the mid-and-low temperature solar thermochemistry utilizes concentrated solar thermal (473.15–573.15 K) to drive methanol decomposition reaction, reducing irreversible heat collection loss. The produced hydrogen-rich fuel is converted into power through solid oxide fuel cells and micro gas turbines successively, realizing the cascaded utilization of fuel and solar energy. Numerical simulation is conducted to investigate the system thermodynamic performances under design and off-design conditions. Promising results reveal that solar-to-hydrogen and net solar-to-electricity efficiencies reach 66.26% and 40.93%, respectively. With the solar thermochemical conversion and hydrogen-rich fuel cascade utilization, the system exergy and overall energy efficiencies reach 59.76% and 80.74%, respectively. This research may provide a pathway for efficient hydrogen-rich fuel production and power generation. 相似文献