基于鲸鱼算法优化PNN的变压器故障诊断

为了增强变压器故障诊断中概率神经网络(probabilistic neural network,PNN)的诊断能力,提出了一种鲸鱼优化算法(whale optimization algorithm,WOA)与PNN相结合的算法。采用WOA对PNN神经网络的平滑因子参数进行优化,并将优化得到的参数值代入到PNN诊断模型中,通过网络训练得到变压器故障诊断的最佳网络模型。试验结果表明,WOA-PNN算法对变压器的故障诊断能力较强,准确率达到了93.88%,网络训练能力约为97%,此方法具有快速收敛、避免陷入局部极小的能力。与传统PNN相比具有明显的优势,为变压器稳定运行提供强大的技术支撑。

基于V2G的CLLC无无功环流双向隔离型DC/DC变换器

传统的DC/DC变换器均为非隔离型能量单向流动,通过对无无功环流双向隔离型DC/DC变换器的研究发现电路中含有谐振电流且电压波形不稳定,针对这一问题,在无无功环流的双向隔离型DC/DC变换器的电路拓扑中增加了CLLC来进行改进,提出了一种CLLC无无功环流的双向隔离型DC/DC变换器,通过MATLAB/Simulink仿真环境下搭建相应的电路模型,并对其仿真结果进行分析研究,证明了CLLC无无功环流双向隔离型DC/DC变换器具有纹波小,电压稳定性强的优点。

Ginkgo biloba leaf extract effects on inducible nitric oxide synthase, Bcl-2, and Bax expression in rat models of spinal cord injury

BACKGROUND：Ginkgo biloba leaf extract exhibits neuroprotective effects in spinal cord injury. However, the mechanisms of action remain unclear. OBJECTIVE： To investigate inducible nitric oxide synthase （iNOS） and Bcl-2/Bax expression in the injured spinal cord, and to explore the neuroprotective mechanisms of ginkgo biloba leaf extract in rats with spinal cord injury. DESIGN, TIME AND SETTING： The randomized, controlled, cell molecular biology experiment was performed at Soochow University, China from March 2007 to March 2008. MATERIALS： A total of 120 healthy, adult Sprague Dawley rats were selected for this study. Rat models of moderate acute thoracic （T9） spinal cord injury were established using the modified Allen method. Shuxuening injection was obtained from Zhenbaodao Pharmaceutical Co., Ltd., China. Methylprednisolone was purchased from North China Pharmaceutical Co., Ltd. METHODS： All rats were equally and randomly divided into four groups. Only the spinal cord was exposed in the sham operation group rats. In the trauma group, rats were not treated with drugs following spinal cord injury. Rats in the hormone group were intraperitoneally injected with 30 mg/kg methylprednisolone following spinal cord injury. Rats in the ginkgo biloba leaf extract group were intraperitoneally infused with a 1.0 mL/kg Shuxuening injection per day. MAIN OUTCOME MEASURES： At 1 hour, as well as 1, 3, 5, 7, and 14 days after spinal cord injury, iNOS- and Bcl-2/Bax-positive cells were quantified with immunohistochemistry. Pathological changes were detected using hematoxylineosin staining under an optical microscope. RESULTS： Spinal cord injury in the ginkgo biloba leaf extract and hormone groups was milder compared with the trauma group. Demyelination was significantly ameliorated and the necrotic cavity was obviously reduced in the injured spinal cord of rats in the ginkgo biloba leaf extract and hormone groups at each time point. iNOS expression was increased in the injured spinal cord, and reached a peak at 5 days. The number of iNOS-positive cells was lower in the ginkgo biloba leaf extract and hormone groups compared with the trauma group （P 〈 0.05-0.01）. The number of iNOS-positive cells was lower in the ginkgo biloba leaf extract group compared with the hormone group at 7 and 14 days after spinal cord injury （P 〈 0.05）. Bcl-2 expression reached a peak at 3 days, and Bax expression reached a peak at 5 days following rat spinal cord injury. Bcl-2 expression was increased, but Bax expression was decreased in the ginkgo biloba leaf extract and hormone groups compared with the trauma group （P 〈 0.05-0.01）. Bcl-2 expression was greater, but Bax expression was reduced in the ginkgo biloba leaf extract group compared with the hormone group at 7 and 14 days after spinal cord injury （P 〈 0.05）. CONCLUSION： Ginkgo biloba leaf extract exhibits neuroprotective effects by upregulating Bcl-2 expression, downregulating Bax expression, and significantly inhibiting high expressions of iNOS in the injured spinal cord. The neuroprotective effects of ginkgo biloba leaf extract are greater compared with methylprednisolone at 1 week after spinal cord injury.

提高低产井采油效率的机械采油技术

抽油机在工作的过程中很容易产生超负荷的问题,本文将结合抽油机发展现状,探讨提高低产井采油效率的机械采油技术。

早期家庭护理在阿尔茨海默病患者中的应用效果

目的:观察早期家庭护理在阿尔茨海默病患者中的应用效果。方法:选取76例阿尔茨海默病患者为研究对象,按照随机数字表法分为对照组和观察组各38例。对照组采用常规护理,观察组在对照组基础上采用早期家庭护理,比较两组认知功能[简易智力状态检查量表(MMSE)]评分、生活能力[Barthel指数评定量表(BI)]评分、生命质量[阿尔茨海默病生命质量测评量表(QOL-AD)]评分和护理满意度。结果:护理后,两组MMSE、BI、QOL-AD评分均高于护理前,且观察组高于对照组,差异有统计学意义(P<0.05);观察组护理满意度高于对照组,差异有统计学意义(P<0.05)。结论:在常规护理基础上采用早期家庭护理可提高阿尔茨海默病患者的认知功能评分、日常生活能力评分、生命质量评分和护理满意度,优于单纯常规护理效果。

北东块一区二套注聚泵运行效率影响因素分析

北东块一区二套是喇嘛甸油田第二个二类B油层工业化聚合物驱推广区块,2017年6月注聚,地面采用单泵单井注入工艺,注聚泵排量采用变频闭环恒流控制。随着注聚时间的推移,由于注聚泵配件磨损、损坏等原因,泵效逐渐降低,变频会自动升高使流量达到方案瞬时,柱塞的加速运动会增加对聚合物母液的机械剪切力、同时增加注聚能耗。

注水管道腐蚀因素及防腐措施分析

油田注水过程中需要使用到注水管道,注水管道运行的稳定性对石油开采效率有着一定的影响,受多方面因素影响,注水管道容易出现腐蚀的情况,导致注水的不稳定,影响石油开采效率,为了确保石油能够有序开采,需要全面分析注水管道的腐蚀成因,采取针对性的预防措施。基于此,本文就对注水管道腐蚀因素及防腐措施等相关内容进行了一个较为详细的概述。