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关键词： INDIVIDUAL OPTIMIZATION   REPRODUCTIVE SUCCESS   OFFSPRING SIZE   NUMBER   BIRDS   AGE   QUALITY   WEIGHT   MODEL   ABUNDANCE  

摘要： Egg production is a costly component of reproduction for female birds in terms of energy expenditure and maternal investment. Because resources are typically limited, clutch size and egg mass are expected to be constrained, and this putative trade-off between offspring number and size is at the core of life history theory. Nevertheless, empirical evidence for this trade-off is equivocal at best, as individual heterogeneity in resource acquisition and allocation may hamper the detection of the negative correlation between egg number and mass within populations. Here, we investigated how female body mass and landscape composition influences clutch size, egg mass, and the relationship between these two traits. To do so, we fitted linear mixed models using data from tree swallows Tachycineta bicolor breeding in a network of 400 nestboxes located along a gradient of agricultural intensity between 2004 and 2011. Our dataset comprised 1463 broods for clutch size analyses and 4371 eggs (from 847 broods laid between 2005-2008) for egg mass analyses. Our results showed that agricultural intensity negatively impacted clutch size, but not egg mass nor the relationship between these two traits. Female mass, on the other hand, modulated the trade-off between clutch size and egg mass. For heavier females, both traits increased jointly, without evidence of a trade-off. However, for lighter females, there was a clear negative relationship between clutch size and egg mass. This work shows that accounting for individual heterogeneity in body mass allows the detection of a clutch size/egg mass trade-off that would have remained undetected otherwise. Identifying habitat and individual effects on resource allocation towards reproductive traits may help bridging the gap between predictions from theory and empirical evidence on life history trade-offs.

关键词： NF-KAPPA-B   VIRAL-INFECTION   POSITIVE FEEDBACK   IMMUNE-RESPONSES   IKK-EPSILON   ACTIVATION   INDUCTION   PATHWAY   BINDING   ROLES  

摘要： Viral infection or lipopolysaccharide (LPS) treatment induces expression of a large array of genes, the products of which play a critical role in host antipathogen immunity and inflammation. We have previously reported that the expression of ubiquitin-specific protease 25 (USP25) is significantly up-regulated after viral infection or LPS treatment, and this is essential for innate immune signaling. However, the mechanism behind this phenomenon is unclear. In this study, we found that viral infection-induced up-regulation of Usp25 is diminished in cells lacking interferon regulatory factor 7 (IRF7) or interferon alpha receptor 1 (IFNAR1) but not p65. Sendai virus- or type I interferon-induced up-regulation of Usp25 requires de novo protein synthesis of IRF7. Furthermore, IRF7 directly binds to the two conserved IRF binding sites on the USP25 promoter to drive transcription of Usp25, and mutation of these two sites abolished Sendai virus-induced IRF7-mediated activation of the USP25 promoter. Our study has uncovered a previously unknown mechanism by which viral infection or LPS induces up-regulation of USP25.

关键词： Dual clutch transmission   Shifting process control   Estimation of torque transmitted by clutch   Unscented Kalman filter   Real vehicle test   SIMULATION   DYNAMICS   VEHICLE  

摘要： The key toward realizing no-impact gear shifting for dual clutch transmission (DCT) lies in the coordination control between the engine and dual clutches, as well as the accurate closed-loop control of torque transmitted by each clutch and the output torque of the engine. However, the implementation and control precision of closed-loop control are completely dependent on the effective measurement or estimation of the instant transmission torque of the clutch. This study analyzes the DCT shifting process, and builds a three-dimensional (3D) clutch model and mathematical model of a DCT vehicle powertrain system. The torque transmitted by a twin clutch during the upshifting process is estimated by applying the unscented Kalman filter (UKF) algorithm. Then, the torque estimation algorithm is verified using a DCT prototype vehicle installed with a torque sensor on the drive half-shaft. The experimental results show that the designed UKF torque estimation algorithm can estimate the transmission torques of two clutches in real time; further, it can be directly used for DCT shift control and improving the shifting quality. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： 液粘调速离合器   传递转矩   摩擦片  

摘要： 本文阐述了液体粘性传动调速离合器的基本工作原理。对离合器的主要工作部件—摩擦片进行了数学建模分析,得出两摩擦片间传动转矩的数学表达式,并得出影响传递转矩大小的主要因素。

关键词： 双离合器自动变速箱   温度诊断   V流程   代码生成  

摘要： 文章首先对开发背景和V型开发流程进行了简单介绍,在此基础上,按照离合器温度诊断和处理要求,分析了双离合器自动变速箱离合器温度诊断和处理系统应该具备的功能,并设计了实现这些功能的控制策略,基于此在Matlab/simulink环境中建立了离合器温度诊断和处理系统模型,并利用Targetlink工具进行模型转化、定标、自动代码生成,并将生成的代码与底层接口函数进行集成、编译、刷写到TCU中,并用CANape标定工具对控制程序进行调试和测试,经对测试结果的分析,验证了该离合器诊断和处理程序功能正确,满足要求,可以应用。

关键词： 液粘调速离合器   AMESim   动态接合特性  

摘要： 为了在不增加系统装机功率的前提下提升驱动扭矩,设计了一种'电机+飞轮+液粘调速离合器'驱动系统。创建了驱动系统各能量传递环节的数学模型、油膜承载力模型和驱动系统的AMESim仿真模型,揭示了飞轮转动惯量、油膜厚度控制曲线等因素对液粘调速离合器动态接合特性的影响规律,得到了扭矩、转速及冲击度变化曲线,搭建了相应的实验台架。仿真和实验结果表明,通过合理控制液粘调速离合器的油膜厚度,实现了持续时间长达50 s的两倍额定扭矩的输出,可满足大中型机械设备对于启动扭矩大、冲击度小的工程需求。

关键词： 滚珠   超越离合器   设计  

摘要： 针对滚柱式超越离合器结构存在缺陷,导致传动轴运转过程中受到冲击导致十字轴断裂的故障,通过对超越离合器的结构进行详细的分析,找到了结构所存在的问题,通过对超越离合器进行改进设计,解决了超越离合器弹簧固定不可靠的问题。改进后的结构经过了试验验证,保证了超越离合器安全、可靠工作。

关键词： 高速齿轮   多片离合器   套筒扳手   六角螺母   中心孔   从动盘   离合器摩擦片   传动齿轮   离心式离合器   膜片弹簧  

摘要： （上接2016年第5期）b）拆去高速齿轮使用专用齿卡在离合器大齿轮与高速齿轮之间（如图24所示）,防止其转动,持对边尺寸为22 mm的套筒扳手拆去曲轴右端面上的高速齿轮六角螺母,取出高速齿轮（如图25所示）,同时将离合器右端面凹槽内的＂889101＂平面轴承用一字起伸入其间后取出。