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51.
52.
以适用于中等水深(50~200 m)的新型潜式浮式风力机为研究对象,该风力机基础综合Spar式、半潜式及张力腿(TLP)3类浮式风力机基础的优点,运行时基础主体淹没在水下,具有较小的水线面(如同Spar平台),受波浪影响较小;平台通过张紧式系泊线与海床相连(如同TLP平台),具有良好的垂荡和摇摆运动特性;拖航状态下,浮式平台处于半潜状态,水线面面积大(如同半潜式平台),具有良好的浮稳性。通过分析不同波况下的潜式浮式风力机耦合动力响应得到潜式浮式基础的横荡、纵荡、垂荡及纵摇运动响应,以及发电功率、叶片根部弯矩、塔筒顶部和底部弯矩、锚链张力时程曲线。研究结果表明:波浪对于结构的纵摇运动的影响最为明显,对发电功率、叶片根部弯矩和塔筒顶部弯矩影响较小,对塔筒底部弯矩和系泊线张力影响较大。 相似文献
53.
Fair bandwidth allocation (FBA) has been studied in optical burst switching (OBS) networks, with the main idea being to map the max-min fairness in traditional IP networks to the fair-loss probability in OBS networks. This approach has proven to be fair in terms of the bandwidth allocation for differential connections, but the use of the ErlangB formula to calculate the theoretical loss probability has made this approach applicable only to Poisson flows. Furthermore, it is necessary to have a reasonable fairness measure to evaluate FBA models. This article proposes an approach involving throughput-based-FBA, called TFBA, and recommends a new fairness measure that is based on the ratio of the actual throughput to the allocated bandwidth. An analytical model for the performance of the output link with TFBA is also proposed. 相似文献
54.
The use of Nannochloropsis sp. as a source of omega‐3 fatty acids in dry pasta: chemical,technological and sensory evaluation 下载免费PDF全文
Estefanía Rodríguez De Marco María Eugenia Steffolani Marcela Martínez Alberto E. León 《International Journal of Food Science & Technology》2018,53(2):499-507
Nannochloropsis is a microalga characterised by having high amounts of eicosapentaenoic acid (EPA), a fatty acid known for its health benefits. The aim of this study was to elaborate dry pasta with a significant contribution of EPA using Nannochloropsis sp., without affecting the quality product and with good consumer acceptance. Technological quality was analysed in terms of cooking properties and texture profile. Cooked pasta was characterised through proximal composition, phenolic compound, fatty acid content and sensorial analysis. It was possible to replace up to 30% of wheat flour with microalgae without affecting the technological quality of pasta and with a significant contribution of EPA to the daily diet (0.237 g per 100 g pasta). The incorporation of 10% and 20% Nannochloropsis in pasta formulation allowed to decrease the n6:n3 ratio from 25:1 to 5:1 and 2:1, respectively. Therefore, the microalgae are an interesting ingredient to increase EPA consumption in products like pasta, while the sensory evaluation confirms the possibility towards a commercial approach. 相似文献
55.
提出了一种改进的浮动板调制器和对正负偏电压的故障检测电路,利用MOSFET寄生电容特性,通过固定脉宽窄脉冲控制调制脉宽,通过增加负偏MOSFET提高输出负偏电压。对故障检测电路进行仿真实验,通过模拟故障,验证故障检测报警信号发生时间均在微秒级别。完成样机的搭建,利用多重方式解决高压绝缘问题,并对其加电进行试验验证,分析实验波形,证明此电路满足设计要求并且具有可行性。 相似文献
56.
Christine Vignon Christelle Debeissat Jrme Bourgeais Nathalie Gallay Farah Kouzi Adrienne Anginot Frdric Picou Philippe Guardiola Elfi Ducrocq Amlie Foucault Nomie Ravalet Louis-Rome Le Nail Jorge Domenech Marie-Christine Bn Marie-Caroline Le Bousse-Kerdils Emmanuel Gyan Olivier Herault 《International journal of molecular sciences》2020,21(22)
The bone marrow (BM) microenvironment plays a crucial role in the development and progression of leukemia (AML). Intracellular reactive oxygen species (ROS) are involved in the regulation of the biology of leukemia-initiating cells, where the antioxidant enzyme GPx-3 could be involved as a determinant of cellular self-renewal. Little is known however about the role of the microenvironment in the control of the oxidative metabolism of AML cells. In the present study, a coculture model of BM mesenchymal stromal cells (MSCs) and AML cells (KG1a cell-line and primary BM blasts) was used to explore this metabolic pathway. MSC-contact, rather than culture with MSC-conditioned medium, decreases ROS levels and inhibits the Nrf-2 pathway through overexpression of GPx3 in AML cells. The decrease of ROS levels also inactivates p38MAPK and reduces the proliferation of AML cells. Conversely, contact with AML cells modifies MSCs in that they display an increased oxidative stress and Nrf-2 activation, together with a concomitant lowered expression of GPx-3. Altogether, these experiments suggest that a reciprocal control of oxidative metabolism is initiated by direct cell–cell contact between MSCs and AML cells. GPx-3 expression appears to play a crucial role in this cross-talk and could be involved in the regulation of leukemogenesis. 相似文献
57.
Gang Zhao Le Shi Jianbo Xu Xiaohui Yan T.S. Zhao 《International Journal of Hydrogen Energy》2018,43(3):1470-1478
In this paper, we have investigated the role of phosphorus (P) in nitrogen (N) and phosphorus dual-doped carbon electrocatalyst for oxygen reduction reaction (ORR) in alkaline media with three samples prepared by varying the doping orders of N and P. Results show that the resultant N-POMC (first doped with P, then N) exhibits an outstanding activity for ORR in alkaline media. The mechanism leading to the improved activity is found to be associated with the orientation effect of the first doped P on the later doped N, by increasing the ratio of graphitic-N significantly. Furthermore, a portion of the first doped P can act as the doping sites and be replaced by the later doped N, called ‘self-sacrifice’ mode, which is confirmed by both experiments and density functional theory (DFT) calculations. However, this orientation effect cannot be observed in the other two dual-doped samples. In addition, experimental and DFT calculation also prove that the amount of graphitic-N is important in improving the activity for ORR. The doping strategy reported in this work is applicable to various co-doping systems in exploring the synergy effect of different dopants and improving activity for ORR. 相似文献
58.
This paper presents a comprehensive cross-layer framework on the performance of transmission control protocol (TCP) over a free-space optical (FSO) link, which employs automatic repeat request (ARQ) and adaptive modulation and coding (AMC) schemes. Not similar to conventional works in the literature of FSO, we conduct a Markov error model to accurately capture effects of burst errors caused by atmospheric turbulence on cross-layer operations. From the framework, we quantify the impacts of different parameters/settings of ARQ, AMC, and the FSO link on TCP throughput performance. We also discuss several optimization aspects for TCP performance. 相似文献
59.
针对变流量制冷(Variable Refrigerant Flow,VRF)系统变吸气状态下带液量的精确控制以及控制元件所引起的滞后或超调现象,以变频滚动转子式制冷系统为研究对象,分别通过恒定频率不同阀开度与恒定阀开度不同频率两个实验,建立其单独控制下的拟合模型,得到其在不同工况下的同步控制方法。结果表明:过热度随阀开度的增大而减小,在过热度为6 K以下,即阀开度为27.8%~30%时,过热度控制难度上升,提高冷冻水温度可改善这一状况;过热度随频率的降低而减小,在过热度为5 K以下,即频率为44.5~46.5 Hz时,控制难度上升;吸气干度随阀开度增大而下降,随频率降低而减小;在某一工况下,以系统质量流量为控制目标,可以拟合得到频率与阀开度的关系式,实现同步控制,在变吸气状态可以精确控制吸气干度,不损坏压缩机,并使系统迅速达到稳定状态。 相似文献
60.
Near infrared fluorescent galactose targeted glycopolymer containing m-carborane has been synthesized through ring open and atom transfer radical polymerization, followed by post-functionalization with a cyanine NIR dye. The copolymer could self-assemble into micelles which work as a potential agent for imaging-guided boron neutron capture therapy. The NIR micelles revealed no cytotoxicity for HepG2 cells. An enhanced and fast endocytosis due to the specific interaction between the HepG2 cells and the glycopolymer could be traced by fluorescence microscopy, and the bioimaging makes it possible to trace the nanoparticles and provides information where and when the neutron irradiation should be triggered. 相似文献