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基于改进Hilbert-Huang变换的管路环向裂纹故障诊断研究
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作者 权凌霄 孙世博 +2 位作者 狄梦然 李朋杰 熊国钦 《液压与气动》 北大核心 2024年第4期109-116,共8页
在制造、加工、装配以及服役过程中,航空液压管路可能存在平面型缺陷。在适航载荷作用下,这些缺陷会萌生裂纹并发生扩展,最终导致管路破裂和油液泄漏。为了在管路产生微裂纹时对其进行故障诊断,采用了自行搭建的航空液压管路模态试验平... 在制造、加工、装配以及服役过程中,航空液压管路可能存在平面型缺陷。在适航载荷作用下,这些缺陷会萌生裂纹并发生扩展,最终导致管路破裂和油液泄漏。为了在管路产生微裂纹时对其进行故障诊断,采用了自行搭建的航空液压管路模态试验平台和测控系统,对存在环向裂纹航空液压管路的振动信号进行了采集和预处理。而在对管路振动信号进行分解时,由于经验模态分解(Empirical Mode Decomposition,EMD)算法存在模态混叠问题难以获得准确的本征模态函数(Intrinsic Mode Functions,IMF)。为提高信号处理精度,提出一种基于自适应噪声完备经验模态分解(Complete Ensemble Empirical Mode Decomposition with Adaptive Noise,CEEMDAN)和Hilbert变换理论相结合的改进Hilbert-Huang变换方法对航空液压管路环向裂纹进行故障诊断。研究结果表明,该方法能够更准确地诊断航空液压管路的环向裂纹故障。 展开更多
关键词 航空液压管路 模态分析 改进Hilbert-huang变换 裂纹故障诊断
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腺癌多发转移合并Sister Mary Joseph结节
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作者 师绍敏 毛燕 +4 位作者 胡焕荣 冀雅聪 郭雷洋 张艳丽 刘亚玲 《临床皮肤科杂志》 CAS CSCD 北大核心 2024年第7期422-425,共4页
报告1例腺癌多发转移合并Sister Mary Joseph结节。患者男,49岁。脐部斑块、结节6个月,腰痛2个月。皮肤科检查:脐部一直径3.5 cm的淡红色浸润性斑块,表面可见多个直径1~5 mm淡红色丘疹、结节,簇集呈菜花样外观,质地坚韧,活动度差。CT检... 报告1例腺癌多发转移合并Sister Mary Joseph结节。患者男,49岁。脐部斑块、结节6个月,腰痛2个月。皮肤科检查:脐部一直径3.5 cm的淡红色浸润性斑块,表面可见多个直径1~5 mm淡红色丘疹、结节,簇集呈菜花样外观,质地坚韧,活动度差。CT检查示纵隔内淋巴结增大,腰3~腰5椎体等多处骨质破坏;锝亚甲基二膦酸盐(^(99m)Tc-MDP)全身骨显像示全身骨骼多处异常放射性浓聚灶。皮损组织病理检查:表皮大致正常,真皮全层致密增生的胶原束间肿瘤细胞呈单个或条索状、列兵样排列,部分肿瘤细胞核大、深染,有明显异形性。免疫组化:细胞角蛋白(CK)、CK7、绒毛蛋白(villin)均阳性表达。腰4椎体针吸组织病理检查符合转移性腺癌,免疫组化示CK及低分子质量细胞角蛋白(CAM)5.2均阳性表达。诊断:腺癌多发转移合并Sister Mary Joseph结节。治疗:患者拒绝接受治疗,随访至13个月时死亡。 展开更多
关键词 sister Mary Joseph结节 腺癌 转移性 皮肤转移 骨转移
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Traditional Chinese medicine Pien-Tze-Huang ameliorates LPS-induced sepsis through bile acid-mediated activation of TGR5-STAT3-A20 signalling
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作者 Bei Li Yong Zhang +9 位作者 Xinyuan Liu Ziyang Zhang Shuqing Zhuang Xiaoli Zhong Wenbo Chen Yilin Hong Pingli Mo Shuhai Lin Shicong Wang Chundong Yu 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2024年第4期601-614,共14页
Pien Tze Huang(PZH),a class-1 nationally protected traditional Chinese medicine(TCM),has been used to treat liver diseases such as hepatitis;however,the effect of PZH on the progression of sepsis is unknown.Here,we re... Pien Tze Huang(PZH),a class-1 nationally protected traditional Chinese medicine(TCM),has been used to treat liver diseases such as hepatitis;however,the effect of PZH on the progression of sepsis is unknown.Here,we reported that PZH attenuated lipopolysaccharide(LPS)-induced sepsis in mice and reduced LPS-induced production of proinflammatory cytokines in macrophages by inhibiting the activation of mitogen-activated protein kinase(MAPK)and nuclear factor-kappa B(NF-κB)signalling.Mechanistically,PZH stimulated signal transducer and activator of transcription 3(STAT3)phosphorylation to induce the expression of A20,which could inhibit the activation of NF-κB and MAPK signalling.Knockdown of the bile acid(BA)receptor G protein-coupled bile acid receptor 1(TGR5)in macrophages abolished the effects of PZH on STAT3 phosphorylation and A20 induction,as well as the LPS-induced inflammatory response,suggesting that BAs in PZH may mediate its anti-inflammatory effects by activating TGR5.Consistently,deprivation of BAs in PZH by cholestyramine resin reduced the effects of PZH on the expression of phosphorylated-STAT3 and A20,the activation of NF-κB and MAPK signalling,and the production of proinflammatory cytokines,whereas the addition of BAs to cholestyramine resin-treated PZH partially restored the inhibitory effects on the production of proinflammatory cytokines.Overall,our study identifies BAs as the effective components in PZH that activate TGR5-STAT3-A20 signalling to ameliorate LPS-induced sepsis. 展开更多
关键词 Pien Tze huang Bile acids SEPSIS Inflammation TGR5 STAT3-A20 signalling
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The Quest for Haven in Sister Carrie
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作者 ZHANG Yi-wen 《Journal of Literature and Art Studies》 2024年第5期315-324,共10页
This essay analyses Theodore Dreiser’s Sister Carrie through the lens of cultural studies,examining the portrayal of domesticity and the quest for an ideal home in late-nineteenth-century America.It explores the comp... This essay analyses Theodore Dreiser’s Sister Carrie through the lens of cultural studies,examining the portrayal of domesticity and the quest for an ideal home in late-nineteenth-century America.It explores the complex relationships between the main characters,Carrie and Hurstwood,and their families,as well as their struggles with materialism and alienation.Through close analysis of societal context,the characters’familial backgrounds and emotional yearnings,the essay delves into the characters’longing for stability and belonging and their journey toward understanding the true essence of dwelling amidst the changing urban landscape.It argues that Dreiser’s novel critiques the superficial pursuit of material comforts and highlights the importance of introspection and self-discovery in finding lasting happiness amidst societal turmoil.Ultimately,through the prism of domesticity,the essay delves into broader themes of identity,belonging,and existential fulfillment in a heartless society marked by materialism and alienation. 展开更多
关键词 Theodore Dreiser sister Carrie HOME DOMESTICITY belonging
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Lost,Exile and Return-An Analysis of Sheona’s Identity Reconstruction in“Sisters”from the Perspective of Spatial Theory
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作者 ZHU Ling 《Journal of Literature and Art Studies》 2024年第8期679-683,共5页
“Sisters”is the first novel in Irish-American author Colum McCann’s short story collection-Fishing the Sloe-Black River,which tells the story of Sheona’s search for her identity between Ireland and the United Stat... “Sisters”is the first novel in Irish-American author Colum McCann’s short story collection-Fishing the Sloe-Black River,which tells the story of Sheona’s search for her identity between Ireland and the United States.Colum McCann is skilled in writing about the spiritual dilemmas and identity search of ethnic minorities living in a foreign land.Employing the space theory and Sheona’s perspective,this paper examines her identity loss in Ireland’s patriarchal system,her migration to the US for identity pursuit,and her subsequent transnational journey between the two nations to reconstruct her identity amidst physical and mental trauma. 展开更多
关键词 Colum McCann sisterS identity reconstruction spatial theory
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Reflections on Studying Huang Di Nei Jing in the West
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作者 Edward Neal 《Chinese Medicine and Culture》 2024年第1期72-76,共5页
Huang Di Nei Jing(《黄帝内经》The Yellow Emperor’s Inner Classic) has been the source text of Chinese medicine knowledge and innovation for over two thousand years. Despite this key relevance, many of its ideas and p... Huang Di Nei Jing(《黄帝内经》The Yellow Emperor’s Inner Classic) has been the source text of Chinese medicine knowledge and innovation for over two thousand years. Despite this key relevance, many of its ideas and practices have proven difficult to understand and implement fully into clinical practice. Cultural and language differences can be compounded with these challenges but may also present new opportunities for advancement and insight when studied by researchers outside of the originating culture. This article introduces the method of Classical-Text Archaeology and delves into the author’s two-decade journey of researching this text, with a discussion on cultural differences and issues of medical scholarship. 展开更多
关键词 huang Di Nei Jing Chinese medicine Nei Jing nature-based medicine Classical text research Global health Medical anthropology Classical-Text Archaeology
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My Sister Gina
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作者 王芹芹 《中学生英语》 2024年第13期6-6,共1页
My name is Alice.I have a sister.Her name is Gina.She is tall and looks nice with long hair.My sister is a good student and she's always good for1her classmates and teachers.She does well in math and English.On we... My name is Alice.I have a sister.Her name is Gina.She is tall and looks nice with long hair.My sister is a good student and she's always good for1her classmates and teachers.She does well in math and English.On weekends,she helps me with my study and we play sport2after that.Gina’ room is not very tidy. 展开更多
关键词 sister GINA MY
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Pien Tze Huang alleviates Concanavalin A-induced autoimmune hepatitis by regulating intestinal microbiota and memory regulatory T cells 被引量:1
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作者 Xin Zeng Miao-Hua Liu +6 位作者 Yi Xiong Lin-Xin Zheng Kai-En Guo Hai-Mei Zhao Yu-Ting Yin Duan-Yong Liu Bu-Gao Zhou 《World Journal of Gastroenterology》 SCIE CAS 2023年第45期5988-6016,共29页
BACKGROUND Traditional Chinese medicine has used the drug Pien Tze Huang(PTH),a classic prescription,to treat autoimmune hepatitis(AIH).However,the precise mode of action is still unknown.AIM To investigate the mechan... BACKGROUND Traditional Chinese medicine has used the drug Pien Tze Huang(PTH),a classic prescription,to treat autoimmune hepatitis(AIH).However,the precise mode of action is still unknown.AIM To investigate the mechanism of PTH in an AIH mouse model by determining the changes in gut microbiota structure and memory regulatory T(mTreg)cells functional levels.METHODS Following induction of the AIH mouse model induced by Concanavalin A(Con A),prophylactic administration of PTH was given for 10 d.The levels of mTreg cells were measured by flow cytometry,and intestinal microbiota was analyzed by 16S rRNA analysis,while western blotting was used to identify activation of the toll-like receptor(TLR)2,TLR4/nuclear factor-κB(NF-κB),and CXCL16/CXCR6 signaling pathways.RESULTS In the liver of mice with AIH,PTH relieved the pathological damage and reduced the numbers of T helper type 17 cells and interferon-γ,tumor necrosis factor-alpha,interleukin(IL)-1β,IL-2,IL-6,and IL-21 expression.Simultaneously,PTH stimulated the abundance of helpful bacteria,promoted activation of the TLR2 signal,which may enhance Treg/mTreg cells quantity to produce IL-10,and suppressed activation of the TLR4/NF-κB and CXCL16/CXCR6 signaling pathways.CONCLUSION PTH regulates intestinal microbiota balance and restores mTreg cells to alleviate experimental AIH,which is closely related to the TLR/CXCL16/CXCR6/NF-κB signaling pathway. 展开更多
关键词 Pien Tze huang Autoimmune hepatitis Intestinal microbiota Memory regulatory T cell Toll-like receptor signaling
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Sister Mary Joseph结节一例
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作者 张燕 谢璟 《中国麻风皮肤病杂志》 2023年第4期285-286,共2页
患者,男,54岁。脐部肿块3天。1年前确诊胃癌并行胃大部切除术-空肠吻合术。脐部肿物组织病理示:浸润性或转移性低分化腺癌,部分为印戒细胞癌。结合病史及免疫组化,符合胃来源。诊断为Sister Mary Joseph结节,给予手术切除。
关键词 sister Mary Joseph结节 胃癌
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Building Consensus on Development and Creatinga Better Future Together The 6th Silk Road(Dunhuang)International Cultural Expo
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作者 Su Jiaying Fan Hairui Wu Han 《China & The World Cultural Exchange》 2023年第9期10-12,共3页
From September 6 to 7,the 6th Silk Road(Dunhuang)International Cultural Expo was successful held in Dunhuang.The theme of this year's Dunhuang Expo was"Connecting with the World:Cultural Exchanges and Mutual ... From September 6 to 7,the 6th Silk Road(Dunhuang)International Cultural Expo was successful held in Dunhuang.The theme of this year's Dunhuang Expo was"Connecting with the World:Cultural Exchanges and Mutual Learning".It focused on facilitating cooperation under the Belt and Road Initiative(BRI),carrying forward Dunhuang culture. 展开更多
关键词 TOGETHER huang SILK
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2016-2021年黄淮南部区试大豆品系(种)产量性状的比较分析 被引量:3
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作者 王大刚 杨勇 +1 位作者 胡国玉 黄志平 《中国油料作物学报》 CAS CSCD 北大核心 2024年第1期19-27,共9页
为在黄淮南部合理布局大豆高产品种,对2016-2021年黄淮南部177份参试大豆品系(种)的产量及主要农艺性状在不同年份、不同省份试点、不同来源及主要不同育种单位间的差异进行研究和相关性分析。结果显示,大豆产量相关农艺性状中变异幅度... 为在黄淮南部合理布局大豆高产品种,对2016-2021年黄淮南部177份参试大豆品系(种)的产量及主要农艺性状在不同年份、不同省份试点、不同来源及主要不同育种单位间的差异进行研究和相关性分析。结果显示,大豆产量相关农艺性状中变异幅度最大的是有效分枝,其次是株高和底荚高度,全生育期变异幅度最小。2016-2021年参试大豆品系(种)不同年份平均产量变化范围为2735.00~2918.00 kg·hm^(-2),平均产量最高的年份为2020年;参试大豆品系(种)在四个不同省份试点中,大豆品系(种)产量与单株粒重均呈极显著正相关,山东试点品系(种)株高、主茎节数、有效荚数、单株粒数、单株粒重和百粒重均高于其它试点,平均产量最高,达3156.32 kg·hm^(-2);安徽试点的平均产量最低,仅为2471.15 kg·hm^(-2);主要不同来源参试大豆品系(种)平均产量与单株粒重均呈极显著正相关,平均产量最高的是河南,平均产量为2927.41 kg·hm^(-2),其次是来源于江苏的品系(种);主要不同育种单位中,平均产量最高的选育单位是河南省农业科学院经济作物研究所,所选育的大豆品系(种)平均产量为3063.87 kg·hm^(-2),其在河南和山东试点的平均产量高达3100.42和3491.20 kg·hm^(-2)。研究结果表明黄淮南部不同省份之间大豆产量差异主要与区域有关,不同年份、不同来源及主要不同育种单位间的大豆品系(种)产量也有一定的差异。 展开更多
关键词 大豆 黄淮南部 品系 产量 区试 性状
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Long-term survival of the Sister Mary Joseph nodule originating from breast cancer:A case report
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作者 Koji Kanayama Maki Tanioka +2 位作者 Yoshitsugu Hattori Takuya Iida Mutsumi Okazaki 《World Journal of Clinical Cases》 SCIE 2023年第34期8205-8211,共7页
BACKGROUND A Sister Mary Joseph nodule(SMJN)is an uncommon cutaneous metastasis found in the umbilicus,indicating an advanced malignancy.SMJNs typically originate from intra-abdominal sources,rarely from breast cancer... BACKGROUND A Sister Mary Joseph nodule(SMJN)is an uncommon cutaneous metastasis found in the umbilicus,indicating an advanced malignancy.SMJNs typically originate from intra-abdominal sources,rarely from breast cancer.Diagnosis suggests a poor prognosis with a median survival of approximately 8 mo after detection.Managing patients with SMJNs is challenging,as most receive limited palliative care only.The optimal strategy for long-term survival of these patients remains unclear.CASE SUMMARY A 58-year-old female,previously diagnosed with right breast cancer 17 years ago and underwent breast-conserving surgery,adjuvant radiotherapy,and endocrine therapy,presented with a 2-cm umbilical nodule.Thirteen years previously,metastases were detected in the right supraclavicular,infraclavicular,hilar,and mediastinal lymph nodes.An umbilical nodule emerged four years before the date of presentation,confirmed as a skin metastasis of primary breast cancer upon excisional biopsy.Despite initial removal,the nodule recurred and grew,leading to her referral to our hospital.The patient underwent extensive excision of the umbilical tumor and immediate abdominal wall reconstruction.Endocrine therapy was continued postoperatively.Five years later,no local recurrence was observed,and the patient continued to work full-time,achieving over 9 years of survival following SMJN diagnosis.CONCLUSION This case study aimed to identify the optimal strategy for achieving extended survival outcomes in patients with SMJN through comprehensive treatment.We presented a case of the longest survival in a patient after undergoing a multidisciplinary treatment regimen.Our findings underscore the significance of adopting a multimodal treatment approach comprising timely and wide excision along with adjunctive therapy.This approach can control the disease,prolong survival,and improve the quality of life in patients with SMJN. 展开更多
关键词 sister Mary Joseph nodule Breast cancer Cutaneous metastasis Long-term survival Abdominal wall reconstruction Case report
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Analysis of Narrative Strategies in Colum McCann’s Short Story“Sisters”
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作者 LU Ke 《Journal of Literature and Art Studies》 2023年第1期7-12,共6页
As the opening work of“Fishing the Sloe-Black River Stories,”Irish-American writer Colum McCann’s short story“Sisters”has attracted scholars’interest with its profuse historical background and themes of the time... As the opening work of“Fishing the Sloe-Black River Stories,”Irish-American writer Colum McCann’s short story“Sisters”has attracted scholars’interest with its profuse historical background and themes of the times.From the perspective of narratology,this paper considers that the writer uses narrative techniques such as non-linear narration and embedded structure to express multi-level narrative voices through a first-person narrator,Sheona.These narrative techniques help to fully reflect the theme of the work and endow the work with great aesthetic and ideological value. 展开更多
关键词 Colum McCann sisterS narrative structure narrative voice
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Activities on the Dunhuang Culture Promoting Cultural Exchange Between China and New Zealand
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作者 Qi Zhengjun 《China & The World Cultural Exchange》 2023年第11期17-17,共1页
On October 27,Organized by the Dunhuang Academy and China Cultural Center in Auckland,the"The Story of China-Dunhuang in the World"salon and"Art of Dunhuang Grottoes"lecture was successfully held a... On October 27,Organized by the Dunhuang Academy and China Cultural Center in Auckland,the"The Story of China-Dunhuang in the World"salon and"Art of Dunhuang Grottoes"lecture was successfully held at the Auckland Art Gallery.Zhao Shengliang,Chairman of the Academic Committee of the Dunhuang Academy,was the key speaker. 展开更多
关键词 huang Zealand Chairman
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基于CAMM和CLDAS的黄淮海冬小麦成熟期连阴雨时空特征 被引量:1
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作者 邬定荣 高静 +5 位作者 姬兴杰 张溪荷 王培娟 杨建莹 马玉平 霍治国 《气象与环境科学》 2024年第1期1-9,共9页
利用黄淮海地区2008—2023年的CLDAS数据和同期65个农业气象观测站的冬小麦花期、成熟期观测数据,订正机理性中国农业气象模式(CAMM)中发育模块(RAM)的参数,评估模式对冬小麦成熟期的模拟精度,而后重构格点化的历年成熟期日期,统计成熟... 利用黄淮海地区2008—2023年的CLDAS数据和同期65个农业气象观测站的冬小麦花期、成熟期观测数据,订正机理性中国农业气象模式(CAMM)中发育模块(RAM)的参数,评估模式对冬小麦成熟期的模拟精度,而后重构格点化的历年成熟期日期,统计成熟期前6天后9天共16天的降水量和雨日数,随后基于连阴雨指标,研究连阴雨的时空分布特征。结果表明:(1)RAM模式对冬小麦成熟期具有较好的模拟能力,各站RMSE平均值为2.28±0.46 d,模拟值与实测值的R2为0.915。(2)黄淮海地区冬小麦成熟期降水量和雨日数均呈南北两端高中间低的空间分布格局,区域平均降水量为8.8~84.6 mm,平均值为31.9 mm,雨日数为1.0~9.1天,平均值为5.4天。(3)2008—2023年连阴雨灾害波动较大,其中2009、2013、2018和2023年较为严重,大致呈4~5年发生一次的周期性规律,且灾情呈加重的趋势。(4)连阴雨灾害在黄淮海地区北部很少发生,河北和山东交界处偶发,灾害高发重发区主要集中在河南省,尤其是郑州以南的驻马店和信阳一带最为严重,发生频率约为5年一遇,持续天数多在9天以上。 展开更多
关键词 连阴雨 黄淮海地区 冬小麦 发育模式 格点资料
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Research on the Cultivation of Craftsmanship in Huang Yanpei’s Education Thought
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作者 Shang Wang Fei Peng Jie Qiu 《Journal of Contemporary Educational Research》 2023年第3期14-19,共6页
Skilled talents are the main support for the strategic development of science and technology in China.The quality of talents is an important guarantee for the transformation and upgrading of national industries.By ana... Skilled talents are the main support for the strategic development of science and technology in China.The quality of talents is an important guarantee for the transformation and upgrading of national industries.By analyzing and studying Huang Yanpei’s thought on vocational education,this paper focuses on the cultivation of students’craftsmanship in vocational schools.First,we analyze the results of previous research and then elaborate on the connotations of Huang Yanpei’s education thought and craftsmanship spirit.Lastly,we propose five suggestions for the cultivation of craftsmanship.Our research work carries certain reference value to the study of craftsmanship cultivation in Huang Yanpei’s education thought. 展开更多
关键词 Cultivation of craftsmanship Craftsmanship TEACHING huang Yanpei’s education thought
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Research on the origin of the theory of“heart as monarch”in Huang Di Nei Jing(Yellow Emperor’s Internal Classic)
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作者 Ya-Chen Zhao Ji-Hao Li 《History & Philosophy of Medicine》 2023年第1期24-29,共6页
Scholars have previously attributed the theoretical origin of“the heart is the monarch/ruler”to the monarchical view of politics.However,according to the latest unearthed documents and relevant documents handed down... Scholars have previously attributed the theoretical origin of“the heart is the monarch/ruler”to the monarchical view of politics.However,according to the latest unearthed documents and relevant documents handed down from ancient times,it can be found that the theory of“the heart is the monarch”might derive from the importance of attachment to the“Zhong”ideology in traditional culture,which promoted the concept that the heart as the center of body,should be the ruler and was later evolved as the“monarch”.Similar cognitive views were all mentioned in Confucianism,Taoism,eclectics scholars and other pre-Qin literature,but only in the system of traditional Chinese medicine,they played a significant role in building the heart-centered theory of Zang-Fu.Traditional Chinese medicine is a discipline developed mainly by clinical practice with the fundamental purpose of curing diseases and saving people.Although the philosophy of traditional Chinese medicine(TCM)roots in the pre-Qin Dynasty,the development is unique to the other philosophies.With rich cultural connotations and philosophical thoughts,TCM is certainly the key to the treasures of Chinese civilization and deserves more attention and exploration. 展开更多
关键词 huang Di Nei Jing the heart is the monarch Zhong the pre-Qin thoughts traditional Chinese medicine culture
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基于HHT的绝缘子泄漏电流分析及放电状态分类识别 被引量:1
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作者 方春华 陶玉宁 +3 位作者 吴田 普子恒 丁璨 黎鹏 《高压电器》 CAS CSCD 北大核心 2024年第1期25-32,共8页
泄漏电流是污秽绝缘子在线监测参数,能动态地反映绝缘子表面的放电状态。文中开展了瓷绝缘子人工污秽放电试验,利用Hilbert-Huang变换分析了不同污闪阶段的泄漏电流固有模态函数分量、Hilbert边际谱与时频熵,从时频域及波形细节提取了1... 泄漏电流是污秽绝缘子在线监测参数,能动态地反映绝缘子表面的放电状态。文中开展了瓷绝缘子人工污秽放电试验,利用Hilbert-Huang变换分析了不同污闪阶段的泄漏电流固有模态函数分量、Hilbert边际谱与时频熵,从时频域及波形细节提取了15个特征量,使用主成分分析法与最小二乘支持向量机分类器对污秽放电状态进行识别。结果表明:起始放电阶段与闪络阶段的泄漏电流固有模态函数分量较多;泄漏电流的Hilbert边际谱上频率主要分布在0~150 Hz、200~250 Hz范围内;闪络前泄漏电流的时频熵值总是大于闪络后的;当训练样本数为测试样本数5倍及以上时,分类器的综合评判准确率可达99%,准确实现了污秽放电状态的分类识别。文中研究结果可为建立绝缘子污闪预警系统提供依据。 展开更多
关键词 绝缘子 泄漏电流 HILBERT-huang变换 主成分分析法 最小二乘支持向量机 分类识别
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基于IHHT‑RF的配电网单相接地故障选线方法 被引量:1
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作者 李泽文 黎文娇 +2 位作者 彭维馨 雷柳 梁流涛 《电力科学与技术学报》 CAS CSCD 北大核心 2024年第1期171-182,共12页
小电流系统发生单相接地故障时故障特征易受高接地过渡电阻、小初相角等弱故障条件影响而导致选线准确率低。为此,提出一种基于改进希尔伯特黄变换—随机森林(improved Hilbert⁃Huang transform⁃random forest,IHHT⁃RF)的配电网单相接... 小电流系统发生单相接地故障时故障特征易受高接地过渡电阻、小初相角等弱故障条件影响而导致选线准确率低。为此,提出一种基于改进希尔伯特黄变换—随机森林(improved Hilbert⁃Huang transform⁃random forest,IHHT⁃RF)的配电网单相接地故障选线方法。首先,提取每条线路在故障发生时的电流暂态信号,通过IHHT提取纯净的暂态电气量,构造标准差、能量熵和幅值畸变度3类特征向量;然后,将特征向量输入RF分类器建立故障选线模型,把故障选线问题转化为二分类问题;最后,将测量数据输入RF分类器中得出分类结果,实现故障线路的自动识别。仿真结果表明,该选线方法综合利用暂态信号的幅值、频率和能量等特征信息,不受弱故障条件、馈线结构等因素的影响,能有效提高故障选线的准确率,具有较强的适应性和可靠性。 展开更多
关键词 配电网 改进希尔伯特黄变换 随机森林 故障选线
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黄汲清与中国大地构造研究
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作者 任纪舜 牛宝贵 +4 位作者 赵磊 徐芹芹 刘建辉 朱俊宾 刘仁燕 《地质学报》 EI CAS CSCD 北大核心 2024年第3期637-646,共10页
本文概述了黄汲清的中国大地构造经典著作——《中国主要地质构造单位》的基本内容和写作基础;阐述了黄汲清及其科学集体的治学风格和工作方法,强调野外地质调查的重要性,突出用新的科学理念和事实,与时俱进不断发展大地构造学。指出大... 本文概述了黄汲清的中国大地构造经典著作——《中国主要地质构造单位》的基本内容和写作基础;阐述了黄汲清及其科学集体的治学风格和工作方法,强调野外地质调查的重要性,突出用新的科学理念和事实,与时俱进不断发展大地构造学。指出大地构造学已从研究地球表层地壳构造、岩石圈构造,进入用地球系统观研究地球整体多圈层构造的新阶段。 展开更多
关键词 黄汲清 大地构造 地球系统 多圈层构造 多旋回
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