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基于深度张量投影网络的机械故障诊断方法研究

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振动工程学报 2024年第4期37卷 657-666页

作者：黄文静李志农王发麟陈亮亮龙盛蓉南昌航空大学无损检测技术教育部重点实验室江西南昌330063

针对现有的、基于深度卷积神经网络的故障诊断方法利用池化层对高阶输入张量降维时容易破坏张量数据,造成数据信息丢失,以及网络结构相对复杂的不足,构造了一种深度张量投影网络。该网络利用张量投影层代替传统卷积神经网络中的池化层,... 详细信息

针对现有的、基于深度卷积神经网络的故障诊断方法利用池化层对高阶输入张量降维时容易破坏张量数据,造成数据信息丢失,以及网络结构相对复杂的不足,构造了一种深度张量投影网络。该网络利用张量投影层代替传统卷积神经网络中的池化层,在对输入的高阶张量数据进行降维时,不会对张量数据造成破坏,避免了特征信息的丢失,提高了模型对故障的识别准确率;并且张量投影层是一种维度可变的降维层,可以简化网络结构。在此基础上,结合高阶谱和深度张量投影网络各自的优点,提出了基于深度张量投影网络的机械故障诊断方法。在提出的方法中,利用高阶谱提取故障信号特征,将得到的高阶张量谱图输入到构建的深度张量投影网络模型中进行高阶张量降维和识别。提出的方法成功应用到齿轮箱故障诊断中。实验结果表明,所提方法能够更好地保留原始故障信息,有效识别不同类型的故障,准确率优于传统深度卷积神经网络故障诊断方法。

关键词：故障诊断深度张量投影网络高阶谱

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尼泊尔藏缅语族群年轻移民的调查——以尼泊尔加德满都博达哈社区为例

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青海民族大学学报（社会科学版） 2024年第1期50卷 124-132页

作者：邬迪李志农云南大学云南昆明650091

尼泊尔藏缅语族群的迁移活动呈现出年轻人口以求学、出家为目的大量外流的新趋势与新特征,对原籍社区人口空间结构和可持续发展产生了巨大的影响,不仅关系到中尼边境地区未来人口结构与发展趋势,甚至可能影响着边疆一线区域的安全稳定... 详细信息

尼泊尔藏缅语族群的迁移活动呈现出年轻人口以求学、出家为目的大量外流的新趋势与新特征,对原籍社区人口空间结构和可持续发展产生了巨大的影响,不仅关系到中尼边境地区未来人口结构与发展趋势,甚至可能影响着边疆一线区域的安全稳定。本文通过在尼泊尔加德满都博达哈社区的实地调查,在博达哈移民社区形成的历史背景下,使用“推拉理论”分析在迁出地局限和迁入地保障双重驱动下的藏缅语族群年轻移民现象,并深入探讨在他们完成学业或还俗后,“留在城市”“跨国迁移”和“回到家乡”三种不同人生选择的生活现状与未来出路。

关键词：尼泊尔藏缅语族群年轻移民博达哈社区

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多层气泡帷幕对水下爆炸防护能力的研究

工程爆破 2024年第3期30卷 136-142页

作者：农志祥吴红波王尹军李基锐马成帅叶风明徐君广西新港湾工程有限公司南宁530200 广西壮族自治区水下破岩工程研究中心南宁530200 广西新港湾水下爆炸技术与应用广西院士工作站南宁530200 安徽理工大学化工与爆破学院安徽淮南232000 矿冶科技集团有限公司北京100160

为了探究多层气泡帷幕对水下爆炸的防护能力,设计层数为1、2、3不同层数的气泡帷幕,结合气流量的变化,分析层数的改变对冲击波衰减能力及对周围地表振动速度的影响。实验条件下,总气流量小于40 L/min,单层气泡帷幕相对于其他层数的气幕... 详细信息

为了探究多层气泡帷幕对水下爆炸的防护能力,设计层数为1、2、3不同层数的气泡帷幕,结合气流量的变化,分析层数的改变对冲击波衰减能力及对周围地表振动速度的影响。实验条件下,总气流量小于40 L/min,单层气泡帷幕相对于其他层数的气幕有着更好的削弱冲击波峰值压力效果;总气流量在40~50 L/min之间,3种不同层数的气泡帷幕防护效果近乎相同,消波能力约75%;总气流量大于50 L/min时,多层气泡帷幕的防护效果逐渐优于单层气泡帷幕,且层数越多,气泡帷幕的消波能力越强。同气流量下,气泡帷幕的层数越多,到达目标区域的冲击波比冲量越小,对周围的破坏能力越低。爆破近点地面的垂向主振频率集中在17 Hz附近,垂向振动速度远大于其他方向的振动速度,且都会随着气流量的增大而逐渐降低。在低气流量下,单层气幕有着更好的振速衰减效果,随着气流量的上升,气泡帷幕层数越多,对振动速度衰减能力越强。

关键词：气泡帷幕冲击波气流量消波能力振动速度

一起诺如病毒感染引起的校园突发公共卫生事件的调查

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微生物学免疫学进展 2024年第4期52卷 56-60页

作者：陆献蒿田红艳农智陆夏瑜易斌百色市疾病预防控制中心疾病控制科广西百色533000

目的对百色市某高中一起诺如病毒(norovirus)感染暴发疫情的流行特征及流行因素进行调查,为学校诺如病毒感染疫情提供防控依据。方法根据病例定义开展搜索,采用描述性流行病学方法对病例特征进行三间分布描述,收集病例的临床数据,采集... 详细信息

目的对百色市某高中一起诺如病毒(norovirus)感染暴发疫情的流行特征及流行因素进行调查,为学校诺如病毒感染疫情提供防控依据。方法根据病例定义开展搜索,采用描述性流行病学方法对病例特征进行三间分布描述,收集病例的临床数据,采集可疑环境样本及具有代表性病例的生物标本进行实验室检测,结合现场卫生学调查分析暴发原因。结果2021年1月20—28日,本次疫情共累计报告病例205例,其中疑似病例189例,确诊病例11例,隐性感染者5例。临床症状主要以腹泻(90.50%)、呕吐(35.50%)为主,无重症及死亡病例。男性罹患率5.85%(116/1984)高于女性罹患率3.74%(89/2381)。高中3个年级学生均有病例报告,但高三罹患率最高,为10.39%,发病风险是高一、高二学生的5.90倍(95%CI:4.473~7.778)。对72份肛拭子、外环境涂抹标本进行诺如病毒GI型、GII型实验室检测,检出16份肛拭子呈GⅡ型诺如病毒核酸阳性。流行曲线显示人传人模式,1月29日学生放假全部离校后无病例报告。结论本事件为一起GⅡ型诺如病毒感染导致的学校暴发疫情,学校未及时采取有效控制措施,最终导致学校暴发疫情的暴发。应加强病例排查及管理,规范吐泻物消毒处理,避免类似事件再次发生。

关键词：诺如病毒感染性腹泻疫情暴发现场流行病学学校卫生食源性疾病隐性感染

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气泡帷幕对水下爆炸防护及对水中生物保护能力的研究

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工程爆破 2024年第4期30卷 150-155页

作者：农志祥吴红波王尹军陈永佳李基锐黄菓树马成帅徐君广西新港湾工程有限公司南宁530200 安徽理工大学化工与爆破学院安徽淮南232001 矿冶科技集团有限公司北京100160

为了研究不同条件的气泡帷幕对水中冲击波的影响,选取气流量、防护距离、气体压力作为变量,对冲击波峰值压力的衰减能力进行研究。实验统一采用单发8号雷管进行测试,结果表明:气流量的增加会提高气泡帷幕的防护能力,当气流量为60 L/min... 详细信息

为了研究不同条件的气泡帷幕对水中冲击波的影响,选取气流量、防护距离、气体压力作为变量,对冲击波峰值压力的衰减能力进行研究。实验统一采用单发8号雷管进行测试,结果表明:气流量的增加会提高气泡帷幕的防护能力,当气流量为60 L/min时,气泡帷幕对水下冲击波的衰减效果达到87.37%,且在该气流量下,气泡帷幕的防护效果趋于平稳;不论在何种气流量下,气泡帷幕越远离爆源,到达目标区域的冲击波峰值压力就会越小,且气泡帷幕与爆源相距40 cm后防护能力逐渐稳定;气压的增大也会提高气泡帷幕的防护能力,但效果不明显。将鲫鱼、鲈鱼、乌鳢鱼、黄颡鱼作为保护研究对象进行实验,结果发现随着气流量的提高,4种鱼类的受损情况都随之降低,可见气泡帷幕对水下生物有着良好的防护能力,且黄颡鱼和乌鳢鱼比鲫鱼与鲈鱼具有更好的抗压能力。

关键词：水下爆炸水中冲击波气泡帷幕爆炸防护气流量

Effect of α phase on evolution of oxygen-rich layer on titanium alloys

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Transactions of Nonferrous Metals Society of China 2019年第3期29卷 534-545页

作者： zhi-sheng nong Yu-nong LEI Jing-chuan ZHU School of Materials Science and Engineering Shenyang Aerospace University Shenyang 110136 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

In order to understand the evolution of oxygen-rich layer (ORL) on titanium alloys, the near α titanium alloy TA15 and α+β type titanium alloy TC4 were thermally exposed in air at 850 °C to evaluate the effect of α phase content on formation and evolution of ORL, and the stability and diffusion of oxygen in α- and β-Ti were investigated by first principles calculations to reveal the oxygen diffusion rate. TA15 with more α phases has a higher diffusion coefficient of ORL evolution than TC4, resulting in forming thicker ORL on TA15 under the same thermal exposure condition. The first principles calculations indicate that octahedral interstice of α-Ti is the most stable site for oxygen atom. The nearest neighbor diffusion between octahedral interstices along the [0001] direction in α-Ti presenting the lowest activation energy is the most favorable oxygen diffusion mechanism in α- and β-Ti.

关键词： oxygen-rich layer titanium alloys oxygen diffusion

Is oxygen therapy beneficial for normoxemic patients with acute heart failure?A propensity score matched study

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Military Medical Research 2022年第3期9卷 265-276页

作者： Yue Yu Ren-Qi Yao Yu-Feng Zhang Su-Yu Wang Wang Xi Jun-Nan Wang Xiao-Yi Huang Yong-Ming Yao zhi-nong Wang Department of Cardiothoracic Surgery Changzheng HospitalNaval Medical University415 Fengyang RoadHuangpu DistrictShanghai 200003China Trauma Research Center Fourth Medical Center and Medical Innovation Research Department of the Chinese PLA General Hospital51 Fucheng RoadHaidian DistrictBeijing 100048China Department of Burn Surgery Changhai HospitalNaval Medical UniversityShanghai 200433China Medical Research Center of War Injuries and Trauma Changzheng HospitalNaval Medical UniversityShanghai 200003China Department of Pathology Changhai HospitalNaval Medical UniversityShanghai 200433China

Background:The clinical efficiency of routine oxygen therapy is uncertain in patients with acute heart failure(AHF)who do not have *** aim of this study was to investigate the association between oxygen therapy and clinical outcomes in normoxemic patients hospitalized with AHF using real-world ***:Normoxemic patients diagnosed with AHF on intensive care unit(ICU)admission from the electronic ICU(eICU)Collaborative Research Database were included in the current study,in which the study population was divided into the oxygen therapy group and the ambient air *** score matching(PSM)was applied to create a balanced covariate distribution between patients receiving supplemental oxygen and those exposed to ambient *** regression and logistic regression models were performed to assess the associations between oxygen therapy and length of stay(LOS),and all-cause in-hospital as well as ICU mortality rates,respectively.A series of sensitivity and subgroup analyses were conducted to further validate the robustness of our ***:A total of 2922 normoxemic patients with AHF were finally included in the ***,42.1%(1230/2922)patients were exposed to oxygen therapy,and 57.9%(1692/2922)patients did not receive oxygen therapy(defined as the ambient air group).After PSM analysis,1122 pairs of patients were matched:each patient receiving oxygen therapy was matched with a patient without receiving supplemental *** multivariable logistic model showed that there was no significant interaction between the ambient air and oxygen therapy for all-cause in-hospital mortality[odds ratio(OR)=1.30;95%confidence interval(CI)0.92–1.82;P=0.138]or ICU mortality(OR=1.39;95%CI 0.83–2.32;P=0.206)in the post-PSM *** addition,linear regression analysis revealed that oxygen therapy was associated with prolonged ICU LOS(OR=1.11;95%CI 1.06–1.15;P<0.001)and hospital LOS(OR=1.06;95%CI 1.01–1.10;P=0.009)after ***,the absence

关键词： Acute heart failure Death Hyperoxia Mortality Oxygen therapy

First-principles calculations of structural,elastic and electronic properties of(TaNb)0.67(HfZrTi)0.33 high-entropy alloy under high pressure

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International Journal of Minerals,Metallurgy and Materials 2020年第10期27卷 1405-1414页

作者： zhi-sheng nong Hao-yu Wang Jing-chuan Zhu School of Materials Science and Engineering Shenyang Aerospace UniversityShenyang 110136China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

To clarify the effect of pressure on a(TaNb)0.67(HfZrTi)0.33 alloy composed of a solid solution with a single body-centered-cubic crystal structure,we used first-principles calculations to theoretically investigate the structural,elastic,and electronic properties of this alloy at different *** results show that the calculated equilibrium lattice parameters are consistent with the experimental results,and that the normalized structural parameters of lattice constants and volume decrease whereas the total enthalpy differenceΔE and elastic constants increase with increasing ***(TaNb)0.67(HfZrTi)0.33 alloy exhibits mechanical stability at high pressures lower than 400 *** high pressure,the bulk modulus B shows larger values than the shear modulus G,and the alloy exhibits an obvious anisotropic feature at pressures ranging from 30 to 70 *** analysis of the electronic structures reveals that the atomic orbitals are occupied by the electrons change due to the compression of the crystal lattices under the effect of high pressure,which results in a decrease in the total density of states and a wider electron energy *** factor is favorable for zero resistance.

关键词： first-principles calculations elastic property electronic structure density of states high-entropy alloys high pressure

Introduction of Dalbergia odorifera enhances nitrogen absorption on Eucalyptus through stimulating microbially mediated soil nitrogen-cycling

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Forest Ecosystems 2021年第4期8卷 789-800页

作者： Xianyu Yao Qianchun Zhang Haiju Zhou zhi nong Shaoming Ye Qi Deng Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou 510650China Center for Plant Ecology Core Botanical GardensChinese Academy of SciencesGuangzhou 510650China State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources College of ForestryGuangxi UniversityNanning 530004China Experimental Center of Topical Forestry Chinese Academy of ForestryPingxiang 532600China

Background:There is substantial evidence that Eucalyptus for nitrogen(N)absorption and increasing the growth benefit from the introduction of N-fixing species,but the underlying mechanisms for microbially mediated soil N cycling remains ***:We investigated the changes of soil pH,soil water content(SWC),soil organic carbon(SOC),total N(TN),inorganic N(NH_(4)^(+)-N and NO_(3)^(-)-N),microbial biomass and three N-degrading enzyme activities as well as the biomass and N productivity of Eucalyptus between a pure Eucalyptus urophylla×grandis plantation(PP)and a mixed Dalbergia odorifera and Eucalyptus plantation(MP)in Guangxi Zhuang Autonomous Region,***:Compared with the PP site,soil pH,SWC,SOC and TN in both seasons were significantly higher at the MP site,which in turn enhanced microbial biomass and the activities of soil N-degrading *** stimulated microbial activity at the MP site likely accelerate soil N mineralization,providing more available N(NH_(4)^(+)-N in both seasons and NO_(3)^(-)-N in the wet-hot season)for Eucalyptus ***,the N productivity of Eucalyptus at the MP site was increased by 19.7% and 21.9%,promoting the biomass increases of 15.1% and 19.2% in the drycold season and wet-hot season,***:Our results reveal the importance of microbially mediated soil N cycling in the N absorption on *** of *** enhances Eucalyptus biomass and N productivity,improve soil N availability and increased soil C and N concentration,which hence can be considered to be an effective sustainable management option of Eucalyptus plantations.

关键词： Eucalyptus plantations Soil physical-chemical properties Microbial biomass Soil enzyme activities Nitrogen availability