迷迭香的抗氧化活性及对藻油氧化稳定性影响的研究

在对迷迭香的DPPH自由基清除能力和还原力与合成抗氧化剂BHT对比研究的基础上,采用Schaal烘箱法,以POV(过氧化值)、TBA(丙二醛值)和DHA含量为氧化稳定性指标,研究了迷迭香在藻油中的抗氧化作用,并探究了增效剂对迷迭香的协同增效作用。结果表明:DPPH自由基清除能力和还原力依次为迷迭香粉BHT迷迭香精油;迷迭香粉和迷迭香精油对藻油都具有较强的保护作用,抗氧化能力依次为0.02%迷迭香粉0.02%BHT0.02%迷迭香精油0.02%VE;0.02%迷迭香粉与0.01%VC棕榈酸酯在藻油中有很强的增效作用。     

Inhibitory effect of antioxidant peptides derived from Pinctada fucata protein on ultraviolet-induced photoaging in mice

The superposition of ultraviolet radiation induced (photodamage) aging process is photoaging. Antioxidant peptides derived from Pinctada fucata protein as raw materials were smeared the back of light-aging. The effect of antioxidant peptides on wrinkle generating, skin restoration capacity after pulled up and measure the active of the superoxide dismutase (SOD), catalase (CAT), hydroxyproline, and glutathione peroxidase (GSH-Px) and lipid peroxidation by kit and histological examination of UVB-irradiated skin that the mitotic index of basal cells, the thickness ratio of the epidermis and dermis, fibroblast count, density of collagen fibers and volume density of dermal microvasculature were studied. The result showed that antioxidant peptides had slowed down the progress of wrinkles formation and skin elasticity deceasing induced by acute irradiation of UVB. It also significantly controlled the speed of lipid peroxidation and the reduction of the activity of SOD, GSH-Px, hydroxyprodline and CAT. Histopathological studies showed that the derived antioxidant peptides could reduce the thickness ratio of the dermis and epidermis and increase the mitotic index of basal cells, fibroblast count, density of collagen fibers and volume density of dermal microvascular, these outcomes confirmed the protective role of antioxidant peptides in the process of photoaging.     

齿轮磨损故障动态响应特征与诊断指标研究

齿轮磨损属于典型的早期故障,为监测齿轮磨损状态,开展齿轮磨损故障机理与诊断指标研究.采用解析建模的方法,定量研究了齿轮磨损对时变啮合刚度和无负载静态传递误差动力学参数的影响规律:采用Archard磨损模型计算齿轮齿面磨损深度,获得沿齿廓方向的非均匀磨损分布;采用势能法计算齿轮啮合刚度,揭示了齿轮磨损对啮合刚度幅值影响的...     

基于GUI的船舶液压推进系统计算辅助设计

为减少船舶液压推进系统计算工作量,采用MATLAB软件的GUI图形界面系统,开发一套船舶液压推进系统计算程序。通过人机交互界面,该程序可以实现不同推进方案下船舶液压推进系统主要部件的参数计算,有效地减少了计算工作量,提高了计算效率。     

Cooperative exploration based on supervisory control of multi-robot systems

When multiple mobile robots cooperatively explore an unknown environment, the advantages of robustness and redundancy are guaranteed. However, available traditional economy approaches for coordination of multi-robot systems (MRS) exploration lack efficient target selection strategy under a few of situations and rely on a perfect communication. In order to overcome the shortages and endow each robot autonomy, a novel coordinated algorithm based on supervisory control of discrete event systems and a variation of the market approach is proposed in this paper. Two kinds of utility and the corresponding calculation schemes which take into account of cooperation between robots and covering the environment in a minimal time, are defined. Different moving target of each robot is determined by maximizing the corresponding utility at the lower level of the proposed hierarchical coordinated architecture. Selection of a moving target assignment strategy, dealing with communication failure, and collision avoidance are modeled as behaviors of each robot at the upper level. The proposed approach distinctly speeds up exploration process and reduces the communication requirement. The validity of our algorithm is verified by computer simulations.     

紫苏水提物联合蒸煮处理对脆肉鲩鱼片冻藏过程中品质的影响

为了研究蒸煮处理及紫苏水提物对脆肉鲩鱼片冻藏品质的影响,以紫苏水提物浸泡的生鱼片（生鱼片组）、紫苏水提物浸泡再进行蒸煮制备的熟鱼片（熟鱼片组）、蒸馏水浸泡的生鱼片（对照组）为研究对象,研究这3 组鱼片在冻藏过程中质构、持水性、盐溶性蛋白含量、Ca2＋-ATPase活性、硫代巴比妥酸（thiobarbituric acid,TBA）值、挥发性盐基氮（total volatile base-nitrogen,TVB-N）含量和感官评分的变化。结果表明：熟鱼片及生鱼片组通过最大冰晶生成带的时间比对照组长;与对照组和生鱼片相比,熟鱼片在冻藏过程中一直维持较高的硬度、弹性、咀嚼性、TBA值和较低的持水力、盐溶性蛋白含量、TVB-N含量;与对照组相比,生鱼片组的质构特性、持水力、盐溶性蛋白含量和Ca2＋-ATPase活力更高,而TBA值和TVB-N含量更低,冻藏300 d后,生鱼片TBA值是贮藏初始时的3.85 倍,TVB-N含量低于20 mg/100 g;感官评价结果进一步表明,3 组样品感官品质在冻藏过程中不断下降,其质地、口感以及汤汁浑浊度评分从高到低依次是熟鱼片、生鱼片和对照组。研究结果证明了紫苏水提物联合蒸煮处理更有利于冻藏过程中脆肉鲩鱼片品质的维持。     

多聚磷酸盐在罗非鱼片中扩散规律的研究

将罗非鱼片用不同浓度的多聚磷酸盐溶液浸泡处理,研究了多聚磷酸盐在鱼片中的扩散规律。结果表明,磷酸盐在鱼片和磷酸盐溶液体系中呈双向扩散,在2%、4%、6%浓度的溶液中,扩散分2个阶段进行,初始阶段磷酸盐由鱼片向溶液扩散明显,最后阶段由溶液向鱼片扩散明显。表现为,鱼片中磷酸盐含量随浸泡时间的延长,先下降,再上升,最后达到平衡的扩散规律,最低时其含量分别为:2.99、3.31和3.50g/kg;平衡时其含量分别为:4.51、4.99和6.20g/kg;在0%和0.5%浓度的溶液中,由鱼片向溶液中扩散占优势,鱼片中磷酸盐含量不断下降,最后达平衡。平衡时其含量分别为1.79g/kg和2.37g/kg。     

全舰计算环境下服务自适应方法研究

在全舰计算环境中,针对应用需求变更,应用服务高效的进行自适应演化才能够充分的利用好各种有限资源。在服务变量定义的基础上,提出了影响服务质量的相关指标;对服务组合的结构路径进行了说明,给出不同结构路径形式下服务质量的计算方法,并提出了组合服务质量模型;对服务变更实例情况进行了分析,最终提出了服务自适应模型算法。     

Scene graph generation by multi-level semantic tasks

Understanding scene image includes detecting and recognizing objects, estimating the interaction relationships of the detected objects, and describing image regions with sentences. However, since the complexity and variety of scene image, existing methods take object detection or vision relationship estimate as the research targets in scene understanding, and the obtained results are not satisfactory. In this work, we propose a Multi-level Semantic Tasks Generation Network (MSTG) to leverage mutual connections across object detection, visual relationship detection and image captioning, to solve jointly and improve the accuracy of the three vision tasks and achieve the more comprehensive and accurate understanding of scene image. The model uses a message pass graph to mutual connections and iterative updates across the different semantic features to improve the accuracy of scene graph generation, and introduces a fused attention mechanism to improve the accuracy of image captioning while using the mutual connections and refines of different semantic features to improve the accuracy of object detection and scene graph generation. Experiments on Visual Genome and COCO datasets indicate that the proposed method can jointly learn the three vision tasks to improve the accuracy of those visual tasks generation.