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关键词： 减定径   伺服控制   变速箱   离合器   S120  

摘要： 减定径轧机具有高速轧制和精密轧制的特点,是高速线材生产线上的核心设备。本文提出一种基于S120和PLC的变速箱伺服控制系统,能够较好地实现减定径变速箱离合器的切换和轧机速比的调整。变速箱伺服电机由西门子S120变频器驱动,离合器的位置根据离合器配置及速比的要求确定。离合器的配置及速比在HMI监控画面中设置,根据轧制表,选择离合器配置方案。HMI中的离合器配置方案通过PLC传入S120变频器,变频器驱动伺服电机完成离合器换挡。

关键词： 离合器踏板   舒适性   踏板刚度  

摘要： 随着现代人对汽车舒适性的要求越来越高,离合器踏板作为汽车内操纵频率较高的装置,其操纵舒适性成为关注的重点。应用离合器操纵系统静态性能测试试验台,以不同的速度踩下离合器踏板,得到踏板力与踏板行程特性曲线。通过数据处理并定义踏板刚度,运用Matlab软件绘制踏板刚度随踏板行程的变化曲线。以踏板刚度变化规律作为离合器踏板舒适性的评价指标。结果表明:在一定的踏板速度范围内,踩下踏板速度越大,踏板刚度变化规律波动越小,舒适性越好;踩下速度越小,踏板刚度变化规律波动越大,舒适性越差。

关键词： 控制单元   离合器   变速器   故障码  

摘要： 上期答案1：首先从故障码“005998（P176E-000）——离合器2意外打开，间歇”的含义分析，说明变速器控制单元J743并未主动要求离合器2（K2离合器）打开的意愿，这也仅仅是变速器控制单元对离合器状态的认知。

关键词： 湿式离合器   执行机构   电液控制   仿真  

摘要： 针对湿式离合器执行机构非线性强、时间延时及控制精度较低等问题,以某汽车自动变速器中湿式离合器的执行机构为研究对象,结合湿式离合器工作特点及控制策略要求,建立一种湿式离合器执行机构电液控制模型,并通过Matlab/Simulink软件进行仿真。研究结果表明,在充电阶段,电动液压阀柱塞、离合器位移,离合器流量首先达到正向最大值,随后逐渐减小直至趋于稳定;在放电阶段,电动液压阀柱塞、离合器位移,离合器流量首先达到负向最大值,随后逐渐增大直至趋于稳定,此外其整体变化趋势与输入电流一致;不同时刻,平均延迟时间不同,延迟时间会降低控制系统的控制精度;不同控制器及预测控制策略对应控制精度不同。

关键词： 湿式双离合器式自动变速器   关键部件   设计  

摘要： 为了满足搭载V6 3.0L发动机的目标车辆在动力性和经济性方面的设计要求,制定了CA7CH350D湿式双离合器自动变速器的总体结构方案。对双离合器自动变速器特殊关键零部件如同步器、驻车机构和换挡机构的结构、布置形式和性能参数进行了分析计算,确定了自动变速器系统集成时各部件的连接形式与空间布置关系。对系统集成后的整车进行了道路测试,车辆的动力性和经济性满足设计需求。

关键词： MSM   Sub-Saharan Africa   HIV/AIDS   Stigma   Homophobia   HIV risk   UNPROTECTED ANAL INTERCOURSE   CAPE-TOWN   KEY POPULATIONS   SELF-EFFICACY   HEALTH-CARE   RISK   MSM   WORKERS   EPIDEMIOLOGY   PREVALENCE  

摘要： Men who have sex with men (MSM) in sub-Saharan Africa (SSA) have been repeatedly found to have high risk of HIV infection, and in spite of the differing nature of the HIV epidemic in the general population between East and Southern Africa, and West and Central Africa, MSM are disproportionately affected by HIV across the entire region. Recent research has examined the drivers of HIV risk, and the dynamics of the MSM HIV epidemic in greater detail. However, this growing knowledge has generally not been translated into effective HIV prevention interventions. In part, this is due to the highly stigmatised and frequently criminalised nature of same-sex sexualities in much of the region. Without human-rights-based advocacy targeting governments and interventions aiming to decrease stigma and homophobia, translating research into effective HIV interventions for MSM in SSA at the scale needed to reduce HIV transmission in this population remains highly unlikely.

关键词： CROCODYLUS-POROSUS   CROCODILUS-YACARE   ECOLOGY   REPTILIA   CUVIER   TRIGONATUS   NESTS  

摘要： We studied nesting of Cuvier's Dwarf Caiman, Paleosuchus palpebrosus, in flooded forest around the Amazon River, and streams draining into the Brazilian Pantanal. Nests were located by searching on foot. Eighty nests were located in the Amazonian sites between 2001 and 2010, and 35 nests were found in the Serra das Araras Ecological Station and streams draining Urucum Mountain on the periphery of the Pantanal between 2006 and 2011. Sizes of embryos indicated that nesting occurs in the Amazonian sites during the dry season and coincides with falling water levels. Although nesting coincides with the warmest and wettest months in the streams around the Pantanal, the streams are not subject to long-term floods. Clutch size varied from eight to 21 eggs, was correlated with female size, and the mean clutch size did not differ between the Amazonian sites and those around the Pantanal.

关键词： egg composition   exogenous nutrients   income breeding   Leach's Storm-Petrel   Oceanodroma leucorhoa   Witless Bay   BREEDING BIOLOGY   EGG COMPOSITION   BIRD EGGS   TRADE-OFFS   SEABIRD   SUCCESS   QUALITY   MASS   DEPARTURE   ATLANTIC  

摘要： Animals with low fecundity, such as seabirds, invest heavily into one or a few eggs per breeding attempt. The loss of these eggs can mean that individuals abandon breeding or invest in a replacement clutch. However, the ability of females to replace clutches may be costly and so replacement clutches may be delayed and they may differ in nutrient content. Replacement clutches are rarely documented conclusively in storm-petrels, and most avian replacement clutches are smaller and differ in composition from original eggs. We removed eggs from Leach's Storm-Petrel (Oceanodroma leucorhoa (Vieillot, 1818)) nests on Gull Island, Witless Bay, Newfoundland and Labrador, Canada, and monitored nest sites for replacement clutches. Leach's Storm-Petrels use locally acquired nutrients to lay a single egg that weighs 20% of a female's body mass. Nearly 70% of pairs (17/26) produced a replacement egg after 22 days and two pairs produced a third egg after a further 21 days. Replacement eggs were nearly identical to original clutches, except for small decreases in length (2%) and volume (3%). We found that Leach's Storm-Petrels were able to acquire sufficient nutrients to produce a second (and in two cases, a third) egg, likely from endogenous nutrients, but delays of 3-6 weeks in breeding may have detrimental effects on fledging success and offspring survival.

关键词： Dual Clutch   Gear Change   Commercial Vehicle Transmission   Downspeeding   Axle Ratio  

摘要： The greater the demand for additional savings in fuel consumption and CO₂ for heavy trucks, the more important are new answers for all areas of the driveline — beginning with the engine through to the axle. With the Traxon Dual automatic dual clutch transmission system, ZF has now developed a key element for this and other requirements.