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An energy harvester combining a piezoelectric cantilever and a single degree of freedom elastic system

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第7期13卷 526-537页

作者： Hong-yan WANG Xiao-biao SHAN tan xie State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150001China College of Computer and Control Engineering Qiqihar UniversityQiqihar 161006China

This paper presents a type of vibration energy harvester combining a piezoelectric cantilever and a single degree of freedom (SDOF) elastic system. The main function of the additional SDOF elastic system is to magnify vibration displacement of the piezoelectric cantilever to improve the power output. A mathematical model of the energy harvester is developed based on Hamilton's principle and Rayleigh-Ritz method. Furthermore, the effects of the structural parameters of the SDOF elastic system on the electromechanical outputs of the energy harvester are analyzed numerically. The accuracy of the output performance in the numerical solution is identified from the finite element method (FEM). A good agreement is found between the numerical results and FEM results. The results show that the power output can be increased and the frequency bandwidth can be improved when the SDOF elastic system has a larger lumped mass and a smaller damping ratio. The numerical results also indicate that a matching load resistance under the short circuit resonance condition can obtain a higher current output, and so is more suitable for application to the piezoelectric energy harvester.

关键词： Piezoelectric cantilever Single degree of freedom elastic (SDOF) system Energy harvesting Finite element analysis(FEA)

肠黏膜组织中微小RNA-141-3p、微小RNA-223-3p水平与新生儿坏死性小肠结肠炎病情的关系及其预测价值

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中华实验外科杂志 2024年第5期41卷 1048-1051页

作者：丁斌谢谭张新康乐驻马店市中心医院小儿普通外科驻马店463000 郑州大学第一附属医院小儿普通外科郑州450052 驻马店市中心医院新生儿科驻马店463000

目的:探讨肠黏膜组织内微小RNA(miR)-141-3p、miR-223-3p水平和新生儿坏死性小肠结肠炎(NEC)病情的关系及其预测价值。方法:选取2021年1月至2023年12月驻马店市中心医院收治的NEC新生儿78例设为观察组,结合病情严重度划分成轻度(22例)... 详细信息

目的:探讨肠黏膜组织内微小RNA(miR)-141-3p、miR-223-3p水平和新生儿坏死性小肠结肠炎(NEC)病情的关系及其预测价值。方法:选取2021年1月至2023年12月驻马店市中心医院收治的NEC新生儿78例设为观察组,结合病情严重度划分成轻度(22例)、中度(30例)和重度(26例)3组。另外选取同时间段驻马店市中心医院体检结果健康的新生儿80例设为对照组,观察两组荧光定量聚合酶链反应(PCR)法测定肠黏膜中的miR-141-3p、miR-223-3p水平,比较观察组不同病情程度患儿的miR-141-3p、miR-223-3p水平,两组之间比较采用t检验,3组之间比较采用方差分析,经Spearman相关分析法分析miR-141-3p、miR-223-3p水平和NEC新生儿病情严重度的关系。绘制受试者工作特征(ROC)曲线并确定曲线下面积(AUC),评估miR-141-3p、miR-223-3p水平对NEC新生儿病情的预测价值。结果:观察组肠黏膜组织中的miR-141-3p表达为1.65±0.38,对照组肠黏膜组织中的miR-141-3p表达为0.94±0.20,观察组高于对照组(t=14.748),差异有统计学意义(P<0.01)。观察组肠黏膜组织中的miR-223-3p表达为0.75±0.14,对照组肠黏膜组织中的miR-223-3p表达为1.40±0.26,观察组低于对照组(t=19.494),差异有统计学意义(P<0.01)。miR-141-3p在轻度组、中度组、重度组患儿肠粘膜组织的表达分别为1.29±0.21、1.60±0.25、1.92±0.34,miR-223-3p在轻度组、中度组、重度组患儿肠粘膜组织的表达分别为0.88±0.18、0.74±0.15、0.62±0.12,伴随NEC新生儿的病情严重度升高,其肠黏膜组织中的miR-141-3p水平呈现升高趋势,miR-223-3p水平呈现降低趋势,组间差异有统计学意义(P<0.01)。肠黏膜组织中miR-141-3p水平和NEC新生儿病情严重度之间为正相关(r=0.761,P<0.01),miR-223-3p水平和NEC新生儿病情严重度之间为负相关(r=-0.655,P<0.01)。miR-141-3p预测NEC新生儿病情是否为重度的AUC为0.947,截断值为1.650,敏感度为0.923,特异度为0.984;miR-223-3p预测NEC新生儿病情是否为重度的AUC为0.889,截断值为0.760,敏感度为0.769,特异度为0.885。结论:肠黏膜组织中miR-141-3p水平和NEC新生儿病情严重度呈正相关,miR-223-3p水平和其病情严重度呈负相关,两项指标检测有助于预测NEC新生儿病情。

关键词：肠黏膜组织微小RNA 新生儿坏死性小肠结肠炎

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激光增材再制造修复技术的现状与发展趋势

科学技术与工程 2024年第4期24卷 1313-1325页

作者：王军华姚成彭建军颉潭成杨芳马喜强徐彦伟河南科技大学机电工程学院洛阳471003 河南省智能制造装备工程技术研究中心洛阳471003 智能数控装备河南省工程实验室洛阳471003 河南省科学院郑州450046

激光增材再制造技术是基于激光熔覆、激光堆焊等激光沉积技术原理实现各种金属零部件损伤部位的几何尺寸或综合性能恢复的绿色制造新技术。针对激光增材再制造技术,具体阐述了增材再制造技术的国内外现状,并详细介绍了激光增材再制造的... 详细信息

激光增材再制造技术是基于激光熔覆、激光堆焊等激光沉积技术原理实现各种金属零部件损伤部位的几何尺寸或综合性能恢复的绿色制造新技术。针对激光增材再制造技术,具体阐述了增材再制造技术的国内外现状,并详细介绍了激光增材再制造的工艺类型以及在各行业的应用,最后展望了激光增材再制造技术的发展趋势。

关键词：激光增材再制造技术技术应用

Metallogenesis of the Baidi Au-Sb deposit, southwest Guizhou Province, China: mineralogical and geochemical evidence from sulfur-bearing minerals

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Acta Geochimica 2024年第2期43卷 199-213页

作者： Jun Yan Yong Xia Qinping tan Zhuojun xie Guosong Ji State KeyLaboratory of Ore Deposit Geochemistry Institute of GeochemistryChineseAcademy of SciencesGuiyang 550081China Guizhou InstituteofTechnology Guiyang550003China No.102 GeologicalTeam Guizhou Bureau of Geologyand Mineral Exploration&DevelopmentZunyi563003China

The Baidi Au-Sb deposit, which contains 8 t of Au and 10,979 Mt of Sb, is a typical and rare paragenetic deposit located in southwestern Guizhou Province, *** studies have focused on individual ores, but have not combined them to identify their paragenetic mechanism or metallogenic regularity. Therefore, we used field investigations, microscopic observations, and in situ analyses to identify the spatial distribution, mineral paragenesis, compositional evolution, and metallogenic material sources of the ore bodies. We also determined the Au and Sb paragenetic characteristics and the metallogenesis of the deposit. The main Au-bearing minerals in the deposit were early(Apy1–2) and late(Apy3) stage arsenopyrites, as well as pre-mineralization(Py1), mineralization(Py2–5), and late mineralization(Py6–7) stage pyrites. The main Sb-bearing minerals were stibnite(Snt), skinnerite, bournonite,and valentinite. The minerals formed in the order of Py1,Py2–3 + Apy1, Py4–5 + Apy2, Snt, and Py6–7 + *** δ34S values of the arsenopyrites and pyrites ranged from-5 to 5‰, while those of stibnite were mostly less than-5‰ in the later mineralization stages. Sulfur was provided by deep magmatic hydrothermal fluids, but sedimentary sulfur was added in the later stages. Moreover,the trace elemental contents fluctuated and eventually became similar to those of the sedimentary strata. By comprehensively considering the ores along with the geological characteristics of the deposit, we determined that deep magma provided the Au during ore formation. Later tectonic changes provided Sb from the sedimentary strata,which precipitated along fault expansion areas and produced Au and Sb paragenesis.

关键词： Au-Sb mineralization Arsenopyrite Pyrite Stibnite Metallogenetic process

Hovering rotor aerodynamics in extreme ground effect

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Chinese Journal of Aeronautics 2024年第7期37卷 204-219页

作者： Zhenlong WU Tianyu ZHANG Huijun tan Haoyu ZHOU Wei CHEN Maixiang xie College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China China Aviation Power Machinery Research Institute Zhuzhou 412002China

This paper presents an experimental and numerical study of the aerodynamics of a moderate-scale rotor hovering in the Extreme Ground Effect(EGE)where rotor height-offground is below half the rotor *** tip vortex field was visualized by using the PIV *** aerodynamic performance,tip vortex trajectory,wall jet characteristics,surface pressure and velocity fields were measured and *** explore more deeply the flow mechanisms of the extreme ground effect,Detached Eddy Simulation(DES)was conducted on completely structured *** results showed significant deviations of the rotor performance in EGE from that in Regular Ground Effect(RGE)with the rotor heights of more than half the rotor ***,the flow structures of the rotor in EGE are considerably complex,such as the wall jet and groundwash flow *** rotor wake flow and tip vortices impact the ground more frequently,resulting in distinctive characteristics of the surface pressure and velocity fields in EGE.

关键词： Rotor Ground effect Tip vortex Detached Eddy Simulation(DES) Groundwash

Compound events of heatwave and dust storm in the Taklamakan Desert

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Science China Earth Sciences 2024年第7期67卷 2073-2083页

作者： Yuzhi LIU Jianping HUANG Ziyuan tan Chenglong ZHOU Dan LI Yongkun xie Key Laboratory for Semi-Arid Climate Change of the Ministry of Education Lanzhou UniversityLanzhou 730000China Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China Taklamakan National Station of Observation and Research for Desert Meteorology in Xinjiang Urumqi 830002China

Taklamakan Desert(TD)has been characterized by numerous heatwaves and dust storms,leading to negative effects on societies and ecosystems at regional and global ***,the association between heatwaves and dust storms is poorly *** this study,we describe the association between heatwaves and dust events and propose a mechanism for such compound events in the *** results show that,from 1993 to 2022,the frequency and intensity of heatwaves in the TD have increased at a rate of 0.21 days year^(-1)and 0.02℃ year^(-1),*** than 40% of heatwaves existed with dust events,which significantly lagged behind ***,the higher the air temperature,the hotter and drier the soil,leading to more dust emissions in the *** high-occurrence heatwave years,a large-scale wave train of“cyclone-anticyclone-cyclone”in the northwest-southeast direction was found,with the anticyclone of which hovered over the TD *** anomalous anticyclones favored the formation and maintenance of heatwaves,and subsequent anomalous cyclones in the wave train triggered strong dust events followed by *** climate warming,the compound events of heatwave and dust storm are becoming bigger hazards threatening the socioeconomic and ecological security in the TD,the profound study of which is critical to understanding regional extreme responses.

关键词： Heatwave Dust storm Compound events Taklamakan Desert

Puerarin mediated miR-30b-5p targeting fibroblast activation protein against oral submucous fibrosis

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BIOCELL 2024年第4期48卷 591-599页

作者： SAIFEI xie HUI xie JINCAI GUO JIN tan YULIN YU MINYI ZHANG SHANG WEN Department of Periodontal Mucosa Hunan University of Chinese MedicineChangshaChina Department of Periodontal Mucosa Changsha Stomatology HospitalChangshaChina Department of Pharmacy Changsha Stomatology HospitalChangshaChina Department of Stomatology The First Hospital of Hunan University of Chinese MedicineChangshaChina

Background:Puerarin(Pue)has been reported to be a natural active ingredient with multiple antiﬁbrotic *** work aimed at exploring the function of Pue in oral submucousﬁbrosis(OSF)***:Human oral mucosaﬁbroblasts(hOMF)were induced with transforming growth factor beta1(TGF-β1)and intervened with *** ofﬁbrosis-related markers were analyzed by Western blot and IF *** viability was characterized by the CCK-8 *** of miR-30 family members were quantiﬁed by *** correlation betweenﬁbroblast activation protein(FAP)and miR-30 family expression was evaluated by the Pearson correlation coefﬁ*** prediction and dual-luciferase reporter assay were employed to verify the regulation between FAP and *** speciﬁc mechanism of Pue on OSF was explored through the promotion or inhibition of ***:After induction by TGF-β1,hOMF showed upregulated Collagen I,Collagen III,and FAP expressions,while miR-30 family expression was downregulated with miR-30b-5p being the most signiﬁ*** intervention inhibited the excessive proliferation of TGF-β1-induced hOMF,downregulated FAP,collagen type 3(COL3A1),collagen type 1(COL1A1),matrix metalloproteinase 1(MMP1),and matrix metalloproteinase 3(MMP3)expressions,and restored miR-30 family *** prediction and dual-luciferase reporter assay revealed that miR-30b-5p selectively inhibited FAP ***,miR-30b-5p mimic suppressed the excessive proliferation of TGF-β1-induced hOMF and declinedﬁbrosis *** intervention signiﬁcantly reversed the promotion of TGF-β1-induced OSF by miR-30b-5p ***:Pue mediated miR-30b-5p targeting FAP against OSF,which provided a theoretical basis for the pathogenesis research and Pue application in OSF.

关键词： Puerarin miR-30b-5p FAP Oral submucous fibrosis

Combining machine and deep transfer learning for mediastinal lymph node evaluation in patients with lung cancer

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虚拟现实与智能硬件（中英文） 2024年第3期6卷 226-238页

作者： Hui xie Jianfang ZHANG Lijuan DING Tao tan Qing LI Department of Radiation Oncology Affiliated Hospital(Clinical College)of Xiangnan UniversityChenzhou 423000China Faulty of Applied Sciences Macao Polytechnic UniversityMacao 999078China Department of Physical examination Beihu Centers for Disease Control and PreventionChenzhou 423000China Department of Radiation Oncology the Third People's Hospital of Chenzhou CityChenzhou 423000China School of Medical Imaging Laboratory Science and RehabilitationXiangnan UniversityChenzhou 423000China

Background The prognosis and survival of patients with lung cancer are likely to deteriorate with *** deep-learning in the detection of lymph node metastasis can facilitate the noninvasive calculation of the likelihood of such metastasis,thereby providing clinicians with crucial information to enhance diagnostic precision and ultimately improve patient survival and *** In total,623 eligible patients were recruited from two medical *** deep learning models,namely Alex,GoogLeNet,Resnet18,Resnet101,Vgg16,Vgg19,and MobileNetv3(small),were utilized to extract deep image histological *** dimensionality of the extracted features was then reduced using the Spearman correlation coefficient(r≥0.9)and Least Absolute Shrinkage and Selection *** machine learning methods,namely Support Vector Machine,K-nearest neighbor,Random Forest,Extra Trees,XGBoost,LightGBM,Naive Bayes,AdaBoost,Gradient Boosting Decision Tree,Linear Regression,and Multilayer Perceptron,were employed to construct classification prediction models for the filtered final *** diagnostic performances of the models were assessed using various metrics,including accuracy,area under the receiver operating characteristic curve,sensitivity,specificity,positive predictive value,and negative predictive *** and decision-curve analyses were also *** The present study demonstrated that using deep radiomic features extracted from Vgg16,in conjunction with a prediction model constructed via a linear regression algorithm,effectively distinguished the status of mediastinal lymph nodes in patients with lung *** performance of the model was evaluated based on various metrics,including accuracy,area under the receiver operating characteristic curve,sensitivity,specificity,positive predictive value,and negative predictive value,which yielded values of 0.808,0.834,0.851,0.745,0.829,and 0.776,*** validation set of the

关键词： Machine learning Deep transfer learning Evaluation Mediastinal lymph node lung cancer patie

Engineering Thermoelectric Performance of α-GeTe by Ferroelectric Distortion

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Energy & Environmental Materials 2024年第2期7卷 171-179页

作者： Yuting Fan Chenghao xie Jun Li Xiangyu Meng Jinchang Sun Jinsong Wu Xinfeng tang Gangjian tan State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China International School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

The rhombohedralα-GeTe can be approximated as a slightly distorted rock-salt structure along its[111]direction and possesses superb thermoelectric ***,the role of such a ferroelectric-like structural distortion on its transport properties remains ***,we performed a systematic study on the crystal structure and electronic band structure evolutions of Ge_(1-x)Sn_(x)Te alloys where the degree of ferroelectric distortion is continuously *** is revealed that the band gap is maximized while multiple valence bands are converged at x=0.6,where the ferroelectric distortion is the least but still *** undistorted,the band gap is considerably reduced,and the valence bands are largely separated ***,near the ferro-to-paraelectric phase transition Curie temperature,the lattice thermal conductivity reaches its minima because of significant lattice softening enabled by ferroelectric *** predict a peak ZT value of 2.6 at 673 K inα-GeTe by use of proper dopants which are powerful in suppressing the excess hole concentrations but meanwhile exert little influence on the ferroelectric distortion.

关键词： electronic band structures ferroelectric distortion lattice softening thermoelectric α-GeTe