共查询到20条相似文献,搜索用时 862 毫秒
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实现二次平行封焊并达到气密性标准是气密性产品返修的关键。该文介绍了一种应用于二次平行封焊的工艺方法,通过对平行封焊后的气密性元器件进行激光开盖,在控制多余物产生后,利用机加工铣平壳体围框表面进行二次平行封焊。测试并分析了气密性元器件系统集成封装(SIP)模块二次平行封焊后的检漏。结果表明,细检漏率<1.01×10-8 Pa·m3/s,粗检漏无连续气泡产生,气密性满足电子与电器元件试验方法(GJB 360B-2009)要求。根据该文介绍的工艺方法可为多余物可控的气密性元器件实现二次平行封焊提供一种有效的解决方案。 相似文献
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Robert Nicoletti 《国外电子元器件》2005,(9):77-77
由22节NiCd/NiMH电池构成的电池包在实际应用中比较常见,这种电池包要求低价位、小尺寸、简单易用的充电器。本文介绍的充电方案是在一款标准的16节NiCd/NiMH电池充电器的基础上稍作改动的一种低成本充电控制器,如图1所示。 相似文献
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陶瓷二次金属化和封接的可靠性 总被引:1,自引:0,他引:1
研究了陶瓷二次金属化对陶瓷-金属封接可靠性的某些影响,指出用一定时间酸溶液处理或高温(干氢)烧结工艺,会使其可靠性有所增长,推荐一次与二次金属化工序连续进行,将有利于封接质量的提高。 相似文献
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分析了锂离子电池的电芯卷绕工艺流程,提出了一种方形锂电池卷绕机的卷绕机构设计,描述了卷针的结构设计和卷针驱动机构的构成,有效地提高了生产效率,保证了卷芯的卷绕精度和卷芯生产的一致性。 相似文献
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本文主要介绍台达BW系列变频器在电池机片轧辊机收放卷上的应用,利用台达BW系列变频器特有的收放卷功能,达到在金属物料在收放卷的恒张力控制。 相似文献
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本文分析了机器零件的结构设计,并以SolidWorks在联轴器的结构设计中的应用为例,介绍SolidWorks软件系统在机器零件设计过程中的具体运用. 相似文献
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Deepa Das Rajendra Kumar Khadanga Deepak Kumar Rout 《International Journal of Communication Systems》2023,36(2):e5376
This paper investigates the resource allocation in a massively deployed user cognitive radio enabled non-orthogonal multiple access (CR-NOMA) network considering the downlink scenario. The system performance deteriorates with the number of users who are experiencing similar channel characteristics from the base station (BS) in NOMA. To address this challenge, we propose a framework for maximizing the system throughput that is based on one-to-one matching game theory integrated with the machine learning technique. The proposed approach is decomposed to solve users clustering and power allocation subproblems. The selection of optimal cluster heads (CHs) and their associated cluster members is based on Gale-Shapley matching game theoretical model with the application of Hungarian method. The CHs can harvest energy from the BS and transfer their surplus power to the primary user (PU) through wireless power transfer. In return, they are allowed to access the licensed band for secondary transmission. The power allocation to the users intended for power conservation at CHs is formulated as a probabilistic constraint, which is then solved by employing the support vector machine (SVM) algorithm. The simulation results demonstrate the efficacy of our proposed schemes that enable the CHs to transfer the residual power while ensuring maximum system throughput. The effects of different parameters on the performance are also studied. 相似文献
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Junha Kim Jinhwan Jung Kwanghee Nam 《Industrial Electronics, IEEE Transactions on》2004,51(2):312-320
An integrated starter/alternator (ISA) is normally designed to have high pole structure (10-14 poles) for high starting torque. However, its back electromotive force (EMF) at the peak revolutions per minute should be less than its battery voltage for the power flow control. For example, the back-EMF of a 12-pole ISA should be 42 V at 6000 r/min. These types of conflicting requirements lead to a nonclassical motor design that has extremely large field-weakening range (8:1/spl sim/10:1). In this paper, we are considering the use of an induction machine instead of a permanent synchronous machine. As an idea for solving the voltage limit problem, two inverters are utilized with an objective of sharing the required voltage. The secondary inverter only takes care of the reactive voltage component that grows very fast in high-speed operation. Therefore, an extra voltage source is not required for the secondary inverter. Only a capacitor bank suffices for the secondary inverter. 相似文献
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为有效解决自动化机器学习的数据处理时间较长等问题,文中提出了数据驱动的自动化机器学习流程生成方法。该方法的数据集匹配模块通过余弦相似性来计算数据集之间的相关性,获取和当前数据集时间匹配程度最高的数据集,并将其和历史数据搜索结果相结合,先选择最优选择动作,扩展和选择MCTS节点。该方法引入了服务关联关注约束模型,可以依据历史数据对所有的存在关联约束强度的选择动作进行指导,生成自动化的机器学习流程。测试结果显示,该方法对不同数据集的学习流程生成耗时均低于580s,生成的流程对单标签和多标签的数据分类结果均在0.92以上,数据完整度均高于95.5%,应用性良好。 相似文献
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An improved automotive electrical system is proposed in which the generator is a high-efficiency AC machine connected to the battery by an AC-DC converter. The electrical loads are isolated from the battery by a DC-DC converter. This will allow gradual conversion to higher battery voltage, regulation of DC distribution voltage, and multiple distribution voltage levels. In the low-voltage, high-current, high-temperature environment of the automobile, in addition to packaging and thermal management, a major problem is the switching loss caused by leakage, package, and other parasitic inductances. The nonlinear resonant switch can remove this source of loss, achieving zero current switching without sacrificing conduction loss or MOSFET switch utilization. For the nonlinear resonant switch in a 1.5 kW load converter application, the upper limit is approximately 20 nH. Hence, device interconnections have low inductance, and MOSFET package inductances are taken into account. A low-voltage, high-current nonlinear resonant switch converter operating at 700 kHz an producing 600 W is described 相似文献