期刊文献+
共找到36,918篇文章
< 1 2 250 >
每页显示 20 50 100
The effect of fasting plasma glucose on in-hospital mortality after acute myocardial infarction in patients with and without diabetes:findings from a prospective,nationwide,and multicenter registry
1
作者 Rui FU Ying-Xuan ZHU +14 位作者 Kong-Yong CUI Jin-Gang YANG Hai-Yan XU Dong YIN Wei-Hua SONG Hong-Jian WANG Cheng-Gang ZHU Lei FENG Wei WU Kai-HongCHEN Yan-Yan ZHAO Ye LU Ke-Fei DOU Yue-Jin YANG on behalf of the CAMI Registry Investigators 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2024年第5期523-533,共11页
OBJECTIVES To evaluate the predictive value of fasting plasma glucose(FPG)for in-hospital mortality in patients with acute myocardial infarction(AMI)with different glucose metabolism status.METHODS We selected 5,308 p... OBJECTIVES To evaluate the predictive value of fasting plasma glucose(FPG)for in-hospital mortality in patients with acute myocardial infarction(AMI)with different glucose metabolism status.METHODS We selected 5,308 participants with AMI from the prospective,nationwide,multicenter CAMI registry,of which 2,081 were diabetic and 3,227 were nondiabetic.Patients were divided into high FPG and low FPG groups according to the optim-al cutoff values of FPG to predict in-hospital mortality for diabetic and nondiabetic cohorts,respectively.The primary endpoint was in-hospital mortality.RESULTS Overall,94 diabetic patients(4.5%)and 131 nondiabetic patients(4.1%)died during hospitalization,and the optimal FPG thresholds for predicting in-hospital death of the two cohorts were 13.2 mmol/L and 6.4 mmol/L,respectively.Compared with individuals who had low FPG,those with high FPG were significantly associated with higher in-hospital mortality in diabet-ic cohort(10.1%vs.2.8%;odds ratio[OR]=3.862,95%confidence interval[CI]:2.542-5.869)and nondiabetic cohort(7.4%vs.1.7%;HR=4.542,95%CI:3.041-6.782).After adjusting the potential confounders,this significant association was not changed.Further-more,FPG as a continuous variable was positively associated with in-hospital mortality in single-variable and multivariable models regardless of diabetic status.Adding FPG to the original model showed a significant improvement in C-statistic and net reclassification in diabetic and nondiabetic cohorts.CONCLUSIONS This large-scale registry indicated that there is a strong positive association between FPG and in-hospital mor-tality in AMI patients with and without diabetes.FPG might be useful to stratify patients with AMI. 展开更多
关键词 PATIENTS fasting INFARCTION
下载PDF
A review of salivary composition changes induced by fasting and its impact on health
2
作者 Nurul Fadhilah Kamalul Aripin NIdayu Zahid +4 位作者 Mohd Aizat Abdul Rahim Hashim Yaacob Parvez I.Haris Zubaidah Haji AbdRahim Rauzah Hashim 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期50-64,共15页
Human saliva is an indispensable fluid that maintains a healthy oral cavity which otherwise can lead to oral diseases(dental caries and periodontitis).In addition,salivary metabolites and microbiome profile provide ea... Human saliva is an indispensable fluid that maintains a healthy oral cavity which otherwise can lead to oral diseases(dental caries and periodontitis).In addition,salivary metabolites and microbiome profile provide early detection of systemic diseases such as cancer and obesity.Salivary diagnostic has gained popularity due to its non-invasive sampling technique.Fasting(abstinence from food or drink or both)research for weight loss and improve health is common,but studies using fasting saliva are scarce.Some metabolites in fasting saliva have been reported with interesting results,which can be enhanced by considering different confounding factors.For example,fasting saliva contains higher salivary nitrite,which is related to nitric oxide(NO).NO is a vasodilator supporting the healthy function of endothelial cells and its deficiency is connected to many diseases.The timely supply of NO through exogenous and endogenous means is highlighted and the potential advantage of fasting salivary composition changes in relation to COVID-19 infection is speculated.This review aims to provide a general discussion on the salivary composition,properties,and functions of the whole saliva,including the health benefits of fasting. 展开更多
关键词 SALIVA fasting NITRATE NITRITE Nitric oxide
下载PDF
Fasting and Cancer: Practice and Patients’ Quality of Life during Ramadan
3
作者 Oumaima Talbi Zineb Benbrahim +6 位作者 Khadija Hinaje Imad Chakri Kaoutar Maadin Lamiae Amaadour Karima Oualla Samia Arifi Nawfel Mellas 《Journal of Cancer Therapy》 2024年第3期49-56,共8页
Introduction: Ramadan is the ninth lunar month of the Muslim calendar, and fasting during Ramadan is one of the five pillars of Islam. Muslim cancer patients and health professionals are faced with a dilemma between t... Introduction: Ramadan is the ninth lunar month of the Muslim calendar, and fasting during Ramadan is one of the five pillars of Islam. Muslim cancer patients and health professionals are faced with a dilemma between the necessity of fasting and its possible adverse effects during Ramadan on the health status of cancer patients. We believe that addressing the issue of fasting in cancer patients is of global interest. Objectives: Prevalence of fasting in cancer patients during Ramadan;Predictive factors of Ramadan fasting in cancer patients;The effect of fasting during Ramadan on the quality of life of cancer patients. Materials and Methods: A structured questionnaire was used to interview adult cancer patients who received chemotherapy IV—or oral treatment at the medical oncology department at the Hassan II University Hospital in Fez during the month of Ramadan 1443 Hijri (April to May 2022). The quality of cancer patients’ lives during their fasting practice in Ramadan was evaluated via the QLQ-C30 questionnaires. Results: 48% of patients did not fast during Ramadan, 22% and 30% were partial and complete fasters respectively. Patients, with OMS 0 to 1, who receive outpatient treatment, non-metastatic patients and patients on oral treatment were more frequent in the completely fasted group. All these factors showed statistically significant values (p < 0.05). 44% of patients sought advice from the treating oncologist if they could fast, while only 15% of patients during Ramadan asked an imam if they could be excused from fasting. A comparison of the QLQ-C30 data showed a significant improvement in emotional functioning with fasting, however, patients had clinically more but not significantly fatigue after fasting. Conclusion: Female gender, good WHO, non-metastatic disease, and oral or outpatient treatment were more likely to be fasting. This study argues that fasting did not influence the quality of life, and appears to significantly improve emotional functioning in cancer patients during Ramadan. 展开更多
关键词 RAMADAN fasting Quality of Life PRACTICE
下载PDF
Mechanistic insights into fasting-induced autophagy in the aging heart
4
作者 Hannaneh Parvaresh Katarzyna Paczek +1 位作者 Md Abdul Alim Al-Bari Nabil Eid 《World Journal of Cardiology》 2024年第3期109-117,共9页
Autophagy is a prosurvival mechanism for the clearance of accumulated abnormal proteins,damaged organelles,and excessive lipids within mammalian cells.A growing body of data indicates that autophagy is reduced in agin... Autophagy is a prosurvival mechanism for the clearance of accumulated abnormal proteins,damaged organelles,and excessive lipids within mammalian cells.A growing body of data indicates that autophagy is reduced in aging cells.This reduction leads to various diseases,such as myocardial hypertrophy,infarction,and atherosclerosis.Recent studies in animal models of an aging heart showed that fasting-induced autophagy improved cardiac function and longevity.This improvement is related to autophagic clearance of damaged cellular components via either bulk or selective autophagy(such as mitophagy).In this editorial,we summarize the mechanisms of autophagy in normal and aging hearts.In addition,the protective effect of fasting-induced autophagy in cardiac aging has been highlighted. 展开更多
关键词 AGING AUTOPHAGY HEART fasting MITOPHAGY
下载PDF
Intermittent fasting and the liver: Focus on the Ramadan model
5
作者 Mohamed H Emara Hanan Soliman +6 位作者 Ebada M Said Hassan Elbatae Mostafa Elazab Shady Elhefnawy Tarik I Zaher Ahmed Abdel-Razik Mohamed Elnadry 《World Journal of Hepatology》 2024年第8期1070-1083,共14页
Intermittent fasting(IF)is an intervention that involves not only dietary modific-ations but also behavioral changes with the main core being a period of fasting alternating with a period of controlled feeding.The dur... Intermittent fasting(IF)is an intervention that involves not only dietary modific-ations but also behavioral changes with the main core being a period of fasting alternating with a period of controlled feeding.The duration of fasting differs from one regimen to another.Ramadan fasting(RF)is a religious fasting for Muslims,it lasts for only one month every one lunar year.In this model of fasting,observers abstain from food and water for a period that extends from dawn to sunset.The period of daily fasting is variable(12-18 hours)as Ramadan rotates in all seasons of the year.Consequently,longer duration of daily fasting is observed during the summer.In fact,RF is a peculiar type of IF.It is a dry IF as no water is allowed during the fasting hours,also there are no calorie restrictions during feeding hours,and the mealtime is exclusively nighttime.These three variables of the RF model are believed to have a variable impact on different liver diseases.RF was evaluated by different observational and interventional studies among patients with non-alcoholic fatty liver disease and it was associated with improve-ments in anthropometric measures,metabolic profile,and liver biochemistry regardless of the calorie restriction among lean and obese patients.The situation is rather different for patients with liver cirrhosis.RF was associated with adverse events among patients with liver cirrhosis irrespective of the underlying etiology of cirrhosis.Cirrhotic patients developed new ascites,ascites were increased,had higher serum bilirubin levels after Ramadan,and frequently developed hepatic encephalopathy and acute upper gastrointestinal bleeding.These complications were higher among patients with Child class B and C cirrhosis,and some fatalities occurred due to fasting.Liver transplant recipients as a special group of patients,are vulnerable to dehydration,fluctuation in blood immunosuppressive levels,likelihood of deterioration and hence observing RF without special precautions could represent a real danger for them.Patients with Gilbert syndrome can safely observe RF despite the minor elevations in serum bilirubin reported during the early days of fasting. 展开更多
关键词 Intermittent fasting Ramadan fasting Non-alcoholic fatty liver disease Liver cirrhosis Peptic ulcer Liver transplantation Gilbert syndrome
下载PDF
Intermittent fasting boosts antitumor immunity by restricting CD11b^(+)Ly6C^(low)Ly6G^(low) cell viability through glucose metabolism in murine breast tumor model
6
作者 Chenghao Fu Zhehao Liang +13 位作者 Zemiao Niu Ning Chen Yuemin Li Zhenhua Liang Yanwei Huo Hao Xi Rong Wang Yonghuan Yan Xiaoruo Gan Mengtian Wang Yun Huang Yan Zhang Mingming Gao Pin Lü 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第4期2327-2345,共19页
Intermittent fasting can benefit breast cancer patients undergoing chemotherapy or immunotherapy.However,it is still uncertain how to select immunotherapy drugs to combine with intermittent fasting.Herein we observed ... Intermittent fasting can benefit breast cancer patients undergoing chemotherapy or immunotherapy.However,it is still uncertain how to select immunotherapy drugs to combine with intermittent fasting.Herein we observed that two cycles of fasting treatment significantly inhibited breast tumor growth and lung tissue metastasis,as well as prolonged overall survival in mice bearing 4T1 and 4T07 breast cancer.During this process,both the immunosuppressive monocytic-(M-)and granulocytic-(G-)myeloid-derived suppressor cell(MDSC)decreased,accompanied by an increase in interleukin(IL)7R^(+)and granzyme B^(+)T cells in the tumor microenvironment.Interestingly,we observed that Ly6G^(low)G-MDSC sharply decreased after fasting treatment,and the cell surface markers and protein mass spectrometry data showed potential therapeutic targets.Mechanistic investigation revealed that glucose metabolism restriction suppressed the splenic granulocytemonocyte progenitor and the generation of colony-stimulating factors and IL-6,which both contributed to the accumulation of G-MDSC.On the other hand,glucose metabolism restriction can directly induce the apoptosis of Ly6G^(low)G-MDSC,but not Ly6G^(high)subsets.In summary,these results suggest that glucose metabolism restriction induced by fasting treatment attenuates the immune-suppressive milieu and enhances the activation of CD3^(+)T cells,providing potential solutions for enhancing immune-based cancer interventions. 展开更多
关键词 Intermittent fasting Ly6G^(low)myeloid-derived suppressor cell apoptosis Extramedullary hematopoiesis Colony stimulating factor Glucose metabolism restriction
下载PDF
基于灰度均值的自适应FAST角点检测优化算法
7
作者 刘艳 李一桐 《电光与控制》 CSCD 北大核心 2024年第2期65-71,91,共8页
光照不均、突变引起的灰度变化会影响图像特征检测效果。为此,设计一种基于灰度均值的自适应FAST-9-12角点检测算法。首先,利用特征点的延展性设计一种小面积双重检测模板,减少像素点与中心点的比较次数,提高区域正检率和检测速度;其次... 光照不均、突变引起的灰度变化会影响图像特征检测效果。为此,设计一种基于灰度均值的自适应FAST-9-12角点检测算法。首先,利用特征点的延展性设计一种小面积双重检测模板,减少像素点与中心点的比较次数,提高区域正检率和检测速度;其次,依据图像局部灰度均值,在每个像素点检测模板内自适应调整阈值,避免灰度变化影响检测效果;最后,根据柔性非极大值抑制的思想设计角点半径抑制原则,筛选鲁棒性更强的角点。在Inria遥感影像数据集上的实验结果表明,FAST-9-12角点检测速度比FAST-12-16,FAST-9-16两种模板提高22%左右,因自适应阈值的提取方式不易受光照影响,检测准确率分别提高4.16和3.11个百分点,实现了图像特征快速和精准检测。 展开更多
关键词 fast角点检测 双重模板 自适应阈值 柔性非极大值抑制 角点半径抑制
下载PDF
基于Kano-FAST的瓦楞纸激光印刷设备设计研究
8
作者 苏晨 曾一帆 郑佳勇 《包装工程》 CAS 北大核心 2024年第20期152-159,共8页
目的推动印刷行业朝更高效的方向迈进,提高印刷设备的易操作性和视觉识别性。方法将Kano和FAST(Function Analysis System Technique)模型引入瓦楞纸激光打印设备设计的前期应用需求分析中,通过问卷的方法获取用户的基本要求,并划分为... 目的推动印刷行业朝更高效的方向迈进,提高印刷设备的易操作性和视觉识别性。方法将Kano和FAST(Function Analysis System Technique)模型引入瓦楞纸激光打印设备设计的前期应用需求分析中,通过问卷的方法获取用户的基本要求,并划分为几个子类型,进而建立Kano的二维功能属性模型。采用FAST法建立功能树,辅助使用Kano模型,从而更精准地分析用户需求,并更好地根据其需求进行优化设计。结果综合运用设计原理,针对性地挖掘瓦楞纸激光印刷设备在造型识别性、操作易用性、生产安全性上存在的问题,进而输出更优解。结论该设计方法的引入有助于为同类型的印刷设备设计提供参考,并引起更多相关厂家的重视,推动印刷行业向更积极的方向发展。 展开更多
关键词 工业设计 瓦楞纸激光印刷设备 KANO模型 fast
下载PDF
基于FAST和Sobol指数法的雷达系统效能敏感性分析
9
作者 胡涛 申立群 +2 位作者 朱镜达 孙成会 董伟锋 《系统工程与电子技术》 EI CSCD 北大核心 2024年第2期561-569,共9页
为了以较小的代价快速提升对空探测雷达系统的综合效能,首先搭建了对空探测雷达系统综合效能的评估指标体系,在此基础上完成了综合效能评估模型的建立。选择两种基于方差原理的全局敏感性分析方法,即傅里叶幅度敏感性测试(Fourier ampli... 为了以较小的代价快速提升对空探测雷达系统的综合效能,首先搭建了对空探测雷达系统综合效能的评估指标体系,在此基础上完成了综合效能评估模型的建立。选择两种基于方差原理的全局敏感性分析方法,即傅里叶幅度敏感性测试(Fourier amplitudes sensitivity test,FAST)和Sobol指数法,分别从频域和时域对建立的评估模型进行敏感性分析。在基于FAST进行敏感性分析时,提出了21维输入指标所对应的特征频率集的选取方法;在基于Sobol指数法进行敏感性分析时,考虑了二阶及高阶敏感性指数的影响。对比FAST和Sobol指数法的分析结果,两种方法获得的敏感性分析结果具有较好的一致性。其中,功率和频率为对空探测雷达系统的主要影响指标,为雷达系统的研发和升级提供了可靠性依据。 展开更多
关键词 雷达系统 效能评估 敏感性分析 傅里叶幅度敏感性测试 Sobol指数法
下载PDF
面向FAST的卫星电磁干扰监测技术研究与实现
10
作者 王钰 黄仕杰 +1 位作者 胡浩 张海燕 《电波科学学报》 CSCD 北大核心 2024年第4期665-672,768,共9页
来自人造卫星的信号是射电天文观测面临的主要射频干扰(radio frequency interference,RFI)之一,这些RFI会将天文信号掩埋,为天文信号的搜寻和分析带来困扰。为了缓减卫星对天文观测的影响,我们在之前的工作中为500 m口径球面射电望远镜... 来自人造卫星的信号是射电天文观测面临的主要射频干扰(radio frequency interference,RFI)之一,这些RFI会将天文信号掩埋,为天文信号的搜寻和分析带来困扰。为了缓减卫星对天文观测的影响,我们在之前的工作中为500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)开发了卫星电磁干扰监测软件,主要包括卫星数据库、观测模块和监测模块。近年来随着多个巨型卫星星座的规划发射以及望远镜观测模式的增多,卫星对射电天文观测的影响更为复杂,已有的软件已经不能满足实际的需要。为此,本文在单个卫星干扰分析的基础上提出了卫星星座的干扰评估方法,并对已有监测软件进行了升级,升级后卫星数据库覆盖更多的在轨卫星及星座信息且能够自动化更新,观测模块能够支持更多种观测模式下的卫星过境预测和干扰评估。在实际天文观测中,通过接在FAST接收机上的频谱仪数据对软件的干扰预测结果进行了实验验证,结果证明升级后的软件能够在多种观测模式下预测可能威胁的卫星以及对应的过境时间,为望远镜观测规划的调整、卫星干扰的规避和接收系统的保护提供重要的支撑。 展开更多
关键词 射电天文 fast 射频干扰 卫星 干扰评估
下载PDF
500m口径射电望远镜(FAST)索网结构风致破坏概率评估
11
作者 杨洋阳 李宏男 +2 位作者 李超 李庆伟 付兴 《土木工程学报》 EI CSCD 北大核心 2024年第8期1-8,22,共9页
大跨空间索网结构风敏感性突出,极易遭受风荷载影响。针对目前缺乏此类结构抗风性能评估方法的问题,以大跨空间索网结构FAST为例,提出一种基于实测风场数据的风致破坏概率分析方法。采集1971年~2020年结构所处地区的大量实测风速数据,... 大跨空间索网结构风敏感性突出,极易遭受风荷载影响。针对目前缺乏此类结构抗风性能评估方法的问题,以大跨空间索网结构FAST为例,提出一种基于实测风场数据的风致破坏概率分析方法。采集1971年~2020年结构所处地区的大量实测风速数据,通过概率分布拟合建立场地的风灾危险性模型。建立FAST的精细化有限元分析模型并模拟风荷载时程输入,采用非线性动力时程分析对结构的风振反应进行计算,基于概率性需求模型绘制易损性曲线。最后,结合得出的风灾危险性和结构易损性,计算得出FAST结构在所处场地实际风灾环境中的破坏概率。研究表明:该地极限风速为17m/s,风速在0~10m/s的概率最大;在120°、210°和300°风向角下,下拉索均为易损构件,210°风向角上吸风对索网结构最不利;在最不利风向角下,结构达到轻微破坏、中等破坏和严重破坏的总破坏概率分别为1.8359×10^(-4)、1.1499×10^(-5)和1.3202×10^(-6)。 展开更多
关键词 fast 索网结构 风灾危险性 风致易损性 破坏概率
下载PDF
CEEMD-FastICA-CWT联合瞬态响应阶次的电驱总成噪声源识别
12
作者 张威 景国玺 +2 位作者 武一民 杨征睿 高辉 《中国测试》 CAS 北大核心 2024年第4期144-152,共9页
以某增程式电驱动总成为研究对象,提出基于联合算法的噪声分离识别模型。首先,采用互补集合经验模态分解(complementary ensemble empirical mode decomposition,CEEMD)联合快速独立分量分析(fast independent component analysis,FastI... 以某增程式电驱动总成为研究对象,提出基于联合算法的噪声分离识别模型。首先,采用互补集合经验模态分解(complementary ensemble empirical mode decomposition,CEEMD)联合快速独立分量分析(fast independent component analysis,FastICA)方法提取纯电模式稳态工况下单一通道噪声信号特征,利用复Morlet小波变换及FFT对各分量信号时频特性进行识别。其次,采用阶次分析法和声能叠加法对稳态分量信号对应的各瞬态响应阶次能量进行对比分析,并结合皮尔逊积矩相关系数(Pearson product moment correlation coefficient,PPMCC)相似性识别确定不同噪声激励源贡献度。结果表明:减速齿副啮合噪声对该增程式电驱总成纯电模式运行噪声整体贡献度最大。 展开更多
关键词 电驱动总成 噪声源识别 互补集合经验模态分解 快速独立分量分析 连续小波变换 阶次分析
下载PDF
基于BP神经网络的FAST馈源舱融合测量预测研究
13
作者 卢朝茂 李明辉 +4 位作者 宋本宁 彭帅 冯禹 于东俊 骆亚波 《天文学进展》 CSCD 北大核心 2024年第3期519-528,共10页
500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical Radio Telescope,FAST)的跟踪观测需要馈源的空间运动配合,馈源舱主要用于实现馈源的精调定位,因此馈源舱位置的高精度测量对FAST望远镜的高效运行意义重大。但当全站... 500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical Radio Telescope,FAST)的跟踪观测需要馈源的空间运动配合,馈源舱主要用于实现馈源的精调定位,因此馈源舱位置的高精度测量对FAST望远镜的高效运行意义重大。但当全站仪设备失效时,无法对采用Kalman算法的GPS/IMU融合测量结果进行修正,导致馈源舱测量精度下降。为了解决这个问题,设计了基于BP(back propagation)神经网络的预测模型,包括数据预处理、模型设计和模型训练验证。模型训练数据为FAST真实测量数据,数据量为40 GB左右。为了验证模型的泛化能力,选取三种运动轨迹数据对模型预测精度进行测试,结果显示,三种运动轨迹下精度都满足15 mm要求。 展开更多
关键词 fast 馈源舱融合测量预测 数据预处理 BP神经网络 时间序列
下载PDF
基于Kano-FAST-FBS的智能扫地机改良设计研究
14
作者 郑镇华 严波 +1 位作者 周乐 史佳龙 《包装工程》 CAS 北大核心 2024年第18期162-171,共10页
目的智能扫地机是智能家居生活中不可或缺的产品,但现有扫地机交互性和功能性趋于一致,为了有效识别居家清扫需求,进一步提升交互性和趣味性,并将其科学转化为产品的功能要素及结构参数,提出一种基于Kano-FAST-FBS模型的产品改良设计方... 目的智能扫地机是智能家居生活中不可或缺的产品,但现有扫地机交互性和功能性趋于一致,为了有效识别居家清扫需求,进一步提升交互性和趣味性,并将其科学转化为产品的功能要素及结构参数,提出一种基于Kano-FAST-FBS模型的产品改良设计方法,以提升智能家居产品的满意度。方法首先,基于Kano模型量化评估智能家居产品的用户需求属性,获得用户需求优先级;其次,运用功能分析系统技术(FAST)将用户需求分别转化为对应的产品功能要素;最后,以功能-行为-结构(FBS)设计模型为基础,实现了产品功能到结构参数的合理映射,进而得到改良产品的各个结构模块,输出最终设计方案。结果以扫地机器人为例,验证了基于Kano-FAST-FBS模型的设计流程。结论在该方法指导下的产品设计能系统地解决用户需求和功能结构模块之间的匹配问题,从而得出更符合用户功能预期的设计方案,并可以为其他类似产品设计提供参考思路。 展开更多
关键词 产品设计 智能扫地机 Kano fast FBS
下载PDF
基于FastICA-LDA的光伏并网逆变器故障诊断
15
作者 张磊 余茂全 夏远洋 《新余学院学报》 2024年第5期40-48,共9页
为了实现逆变器开路故障诊断,提出了一种新的诊断方法。该方法采用快速独立成分分析算法判定逆变器是否发生单管开路故障,如果发生单管开路故障,计算旋转电流Id频域下的特征值,将这些特征值作为线性判别分析模型的输入值,最后由LDA模型... 为了实现逆变器开路故障诊断,提出了一种新的诊断方法。该方法采用快速独立成分分析算法判定逆变器是否发生单管开路故障,如果发生单管开路故障,计算旋转电流Id频域下的特征值,将这些特征值作为线性判别分析模型的输入值,最后由LDA模型输出逆变器工作状态编号,从而实现单管开路定位。经过MATLAB仿真验证表明,所提方法对光伏并网逆变器故障的诊断效果较好。 展开更多
关键词 并网逆变器 开路故障 频域特征 快速独立成分分析 线性判别分析
下载PDF
FAST所受PMT基站电磁干扰及用频防护方法综述
16
作者 王健 赵一博 +5 位作者 杨铖 郝玉龙 士亚菲 张海燕 孙建民 骆丁菱 《电波科学学报》 CSCD 北大核心 2024年第4期602-623,共22页
为确定500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)与其周边公众移动通信(Public Mobile Telecommunications,PMT)系统的电磁兼容(electromagnetic compatibility,EMC)特性,本文综合论述了F... 为确定500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)与其周边公众移动通信(Public Mobile Telecommunications,PMT)系统的电磁兼容(electromagnetic compatibility,EMC)特性,本文综合论述了FAST宁静区内中国移动、中国联通和中国电信三大运营商所属PMT基站对其产生的电磁干扰。首先,从射电天文业务的频谱划分谈起,论述了射电天文业务干扰源类型,引出了其运行保护标准,进而针对FAST详细说明了FAST宁静区的用频法规和保护要求;其次,分析了ITU-R建议电波传播预测与干扰分析方法,并通过实地测量验证了该方法的适用性,进一步针对性地分析了PMT基站的电磁辐射传播特性,综合评估了FAST宁静区内PMT基站的干扰情况:FAST宁静区域90.24%的PMT基站在一定程度上均会对FAST产生干扰,而在所选分析条件下,仅有43.14%的数据符合FAST保护要求;最后,针对PMT基站干扰信号的抑制和消除,分析了常用的射电天文射频干扰抑制方法,同时为保障FAST免受PMT基站干扰,从FAST和PMT基站的角度出发论述了可行的用频防护措施,并基于实施难度、经济成本、策略收益和通信质量4类指标建立了防护方法的评估体系,对所提防护方法进行了实例说明。上述研究成果可为保障FAST的安全观测提供技术基础。 展开更多
关键词 fast 公众移动通信(PMT) 电磁兼容(EMC) 传播损耗 电磁防护
下载PDF
Unraveling the Fundamental Mechanism of Interface Conductive Network Influence on the Fast‑Charging Performance of SiO‑Based Anode for Lithium‑Ion Batteries 被引量:1
17
作者 Ruirui Zhang Zhexi Xiao +6 位作者 Zhenkang Lin Xinghao Yan Ziying He Hairong Jiang Zhou Yang Xilai Jia Fei Wei 《Nano-Micro Letters》 SCIE EI CSCD 2024年第3期53-68,共16页
Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effe... Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effectively addresses the aforementioned problems;however,the impact of its quality on lithium-ion transfer and structure durability is yet to be explored.Herein,the influence of an interface conductive network on ionic transport and mechanical stability under fast charging is explored for the first time.2D modeling simulation and Cryo-transmission electron microscopy precisely reveal the mitigation of interface polarization owing to a higher fraction of conductive inorganic species formation in bilayer solid electrolyte interphase is mainly responsible for a linear decrease in ionic diffusion energy barrier.Furthermore,atomic force microscopy and Raman shift exhibit substantial stress dissipation generated by a complete conductive network,which is critical to the linear reduction of electrode residual stress.This study provides insights into the rational design of optimized interface SiO-based anodes with reinforced fast-charging performance. 展开更多
关键词 fast charging SiO anode Interface conductive network Ionic transport Mechanical stability
下载PDF
Lowering fasting blood glucose with non-dialyzable material of cranberry extract is dependent on host genetic background,sex and diet 被引量:2
18
作者 Fatima Amer-Sarsour Rana Tarabeih +1 位作者 Itzhak Ofek Fuad A.Iraqi 《Animal Models and Experimental Medicine》 CAS CSCD 2023年第3期196-210,共15页
Background:Type 2 diabetes(T2D)is a polygenic metabolic disease,character-ized by high fasting blood glucose(FBG).The ability of cranberry(CRN)fruit to regulate glycemia in T2D patients is well known.Here,a cohort of ... Background:Type 2 diabetes(T2D)is a polygenic metabolic disease,character-ized by high fasting blood glucose(FBG).The ability of cranberry(CRN)fruit to regulate glycemia in T2D patients is well known.Here,a cohort of 13 lines of the genetically diverse Collaborative Cross(CC)mouse model was assessed for the effect of non-dialyzable material(NDM)of cranberry extract in lowering fasting blood glucose.Methods:Eight-week-old mice were maintained on either a standard chow diet(con-trol group)or a high-fat diet(HFD)for 12 weeks,followed by injections of intraperi-toneal(IP)NDM(50 mg/kg)per mouse,three times a week for the next 6 weeks.Absolute FBG(mg/dl)was measured bi-weekly and percentage changes in FBG(%FBG)between weeks 0 and 12 were calculated.Results:Statistical analysis showed a significant decrease in FBG between weeks 0 and 12 in male and female mice maintained on CHD.However,a non-significant in-crease in FBG values was observed in male and female mice maintained on HFD dur-ing the same period.Following administration of NDM during the following 6 weeks,the results show a variation in significant levels of FBG lowering between lines,male and female mice and under the different diets.Conclusion:The results suggest that the efficacy of NDM treatment in lowering FGB depends on host genetic background(pharmacogenetics),sex of the mouse(phar-macosex),and diet(pharmacodiet).All these results support the need for follow-up research to better understand and implement a personalized medicine approach/uti-lization of NDM for reducing FBG. 展开更多
关键词 chow diet(CHD) collaborative cross(CC)mouse model fasting blood glucose(FBG) high-fat diet(HFD) non-dialyzable material(NDM)of cranberry extract type 2 diabetes(T2D)
下载PDF
Dual-single-atoms of Pt-Co boost sulfur redox kinetics for ultrafast Li-S batteries 被引量:1
19
作者 Hanyan Wu Xuejie Gao +7 位作者 Xinyang Chen Weihan Li Junjie Li Lei Zhang Yang Zhao Ming Jiang Runcang Sun Xueliang Sun 《Carbon Energy》 SCIE EI CAS CSCD 2024年第3期53-63,共11页
Applications of lithium-sulfur(Li-S)batteries are still limited by the sluggish conversion kinetics from polysulfide to Li_(2)S.Although various single-atom catalysts are available for improving the conversion kinetic... Applications of lithium-sulfur(Li-S)batteries are still limited by the sluggish conversion kinetics from polysulfide to Li_(2)S.Although various single-atom catalysts are available for improving the conversion kinetics,the sulfur redox kinetics for Li-S batteries is still not ultrafast.Herein,in this work,a catalyst with dual-single-atom Pt-Co embedded in N-doped carbon nanotubes(Pt&Co@NCNT)was proposed by the atomic layer deposition method to suppress the shuttle effect and synergistically improve the interconversion kinetics from polysulfides to Li_(2)S.The X-ray absorption near edge curves indicated the reversible conversion of Li_(2)Sx on the S/Pt&Co@NCNT electrode.Meanwhile,density functional theory demonstrated that the Pt&Co@NCNT promoted the free energy of the phase transition of sulfur species and reduced the oxidative decomposition energy of Li_(2)S.As a result,the batteries assembled with S/Pt&Co@NCNT electrodes exhibited a high capacity retention of 80%at 100 cycles at a current density of 1.3 mA cm^(−2)(S loading:2.5 mg cm^(−2)).More importantly,an excellent rate performance was achieved with a high capacity of 822.1 mAh g^(−1) at a high current density of 12.7 mA cm^(−2).This work opens a new direction to boost the sulfur redox kinetics for ultrafast Li-S batteries. 展开更多
关键词 DFT calculation dual-single-atoms of Pt-Co fast Li-sulfur batteries sulfur redox kinetics XANES analysis
下载PDF
Preoperative Fasting of More Than 14 Hours Increases the Risk of Time-to-Death after Cardiothoracic Surgery in Children:A Retrospective Cohort Study
20
作者 Laortip Rattanapittayaporn Maliwan Oofuvong +1 位作者 Jutarat Tanasansuttiporn Thavat Chanchayanon 《Congenital Heart Disease》 SCIE 2023年第1期23-39,共17页
Background:Prolonged preoperative fasting can cause hypoglycemia,hyperglycemia,and intravascular volume depletion in children.We aimed to examine whether prolonged preoperative fasting is associated with in-hospital m... Background:Prolonged preoperative fasting can cause hypoglycemia,hyperglycemia,and intravascular volume depletion in children.We aimed to examine whether prolonged preoperative fasting is associated with in-hospital mortality and other morbidities in pediatric cardiothoracic surgery.Methods:This retrospective cohort study included children aged 0–3 years who underwent cardiac surgery between July 2014 and October 2020.The patient demographic data,surgery-related and anesthesia-related factors,and postoperative outcomes,including hypoglycemia,hyperglycemia,sepsis,length of intensive care unit stay,and in-hospital mortality,were recorded.The main exposure and outcome variables were prolonged fasting and time-to-death after surgery,respectively.The associations between prolonged fasting and perioperative death were analyzed using multivariate Cox regression analysis.Results:In total,402 patients were recruited.The incidence of perioperative mortality was 21%(85/402).The proportion of perioperative deaths was significantly higher in the prolonged fasting group than that in the normal fasting group.The proportion of postoperative bacteremia and hypoglycemia was significantly higher in the very prolonged fasting group than that in the prolonged fasting group.After adjusting for preoperative conditions and anesthesia-and surgery-related factors,preoperative prolonged fasting>14.4 h was significantly associated with time-to-death(HR[95%CI]:2.2[1.2,3.9],p=0.036).The 30-day survival rates of fasting time>14.4 h,9.25–14.4 h,and<9.25 h were 0.67(0.55,0.81),0.79(0.72,0.87),and 0.85(0.79,0.91),respectively.Conclusions:Preoperative fasting of more than 14.4 h was associated with a two-fold increase in the hazard rate of time-to-death in children who underwent cardiac surgery. 展开更多
关键词 Prolonged preoperative fasting time-to-death in-hospital mortality CHILDREN cardiothoracic surgery
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部