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Microstructural evolution of new type Al-Zn-Mg-Cu alloy with Er and Zr additions during homogenization

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Transactions of Nonferrous Metals Society of China 2017年第7期27卷 1476-1482页

作者： Hao WU Sheng-ping WEN Jun-tai LU Zhen-peng MI Xian-long ZENG Hui HUANG zuo-ren nie School of Materials Science and Engineering Beijing University of Technology Beijing 100124 China

A comprehensive study on the microstructural evolution of a new type Al-Zn-Mg-Cu-Er-Zr alloy duringhomogenization was conducted by optical microscope,scanning electron microscope,transmission electron microscopy and X-raydiffraction *** results show that serious segregation exists in as-cast alloy,and the primary phases are T(AlZnMgCu),S(Al2CuMg)and Al8Cu4Er,which preferentially locate in the grain boundary *** soluble T(AlZnMgCu)and S(Al2CuMg)phases dissolve into the matrix gradually during single-stage homogenized at465°C with prolonging holding time,but the residualAl8Cu4Er phase cannot dissolve *** with the single-stage homogenization,both a finer particle size and a highervolume fraction of L12-structured Al3(Er,Zr)dispersoids can be obtained in the two-stage homogenization process.A suitablehomogenization scheme for the present alloy is(400°C,10h)+(465°C,24h),which is consistent with the results of homogenizationkinetic analysis.

关键词： Al-Zn-Mg-Cu-Er-Zr alloy homogenization microstructural evolution primary phases Al3(Er,Zr) particles

Dislocation evolution and induced precipitation on corrosion resistance of a novel Al-Mg-Zn-Er-Zr alloy during hot compression

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Rare Metals 2023年第7期42卷 2371-2380页

作者： Da Xue Wu Wei Wei Shi Xiao-Rong Zhou Sheng-Ping Wen Xiao-Lan Wu Kun-Yuan Gao Li Rong Peng Qi Hui Huang zuo-ren nie Key Laboratory of Advanced Functional Materials Education Ministry of ChinaBeijing University of TechnologyBeijing100124China Institute of Corrosion Science and Technology Guangzhou510530China Department of Materials The University of ManchesterManchesterM139PLUK

Al-Mg-Zn-Er-Zr alloy was compressed in temperature range from 300 to 500℃to investigate the microstructure *** dynamics simulations were used to study the mechanical behavior and dislocation *** results showed that mobile dislocations are widely distributed in alloys and make important contributions to coordinate compressive *** sessile dislocations hinder the deformation,and the content is about 1/20 of that of mobile *** dynamic recrystallization(CDRX)is considered to be the main recrystallization *** accumulation of dislocations can provide element diffusion channels and driving force forτ(Mg_(32)[Al,Zn]_(49))phase precipitation,resulting in the forced precipitation of discontinuousτphase to replace the continuousβphase(Al_(3)Mg_(2)),which reduces the corrosion potential,resulting in increased corrosion resistance.

关键词： Al-Mg-Zn-Er-Zr alloy Dislocation Corrosion Mg_(32)(AlZn)_(49)phase Molecular dynamics

Fault diagnosis of HVAC system with imbalanced data using multi-scale convolution composite neural network

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Building Simulation 2024年第3期17卷 371-386页

作者： Rouhui Wu Yizhu ren Mengying Tan Lei nie School of Mechanical Engineering Hubei University of TechnologyWuhan430068China Industrial Research Institute of Xiangyang Hubei University of Technology Xiangyang441100China

Accurate fault diagnosis of heating,ventilation,and air conditioning(HVAC)systems is of significant importance for maintaining normal operation,reducing energy consumption,and minimizing maintenance ***,in practical applications,it is challenging to obtain sufficient fault data for HVAC systems,leading to imbalanced data,where the number of fault samples is much smaller than that of normal ***,most existing HVAC system fault diagnosis methods heavily rely on balanced training sets to achieve high fault diagnosis ***,to address this issue,a composite neural network fault diagnosis model is proposed,which combines SMOTETomek,multi-scale one-dimensional convolutional neural networks(M1DCNN),and support vector machine(SVM).This method first utilizes SMOTETomek to augment the minority class samples in the imbalanced dataset,achieving a balanced number of faulty and normal ***,it employs the M1DCNN model to extract feature information from the augmented ***,it replaces the original Softmax classifier with an SVM classifier for classification,thus enhancing the fault diagnosis *** the SMOTETomek-M1DCNN-SVM method,we conducted fault diagnosis validation on both the ASHRAE RP-1043 dataset and experimental dataset with an imbalance ratio of 1:*** results demonstrate the superiority of this approach,providing a novel and promising solution for intelligent building management,with accuracy and F1 scores of 98.45%and 100%for the RP-1043 dataset and experimental dataset,respectively.

关键词： fault diagnosis chiller imbalanced data SMOTETomek multi-scale neural networks

Selective immobilization of Pb(Ⅱ)by biogenic whewellite and its mechanism

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Journal of Environmental Sciences 2024年第3期137卷 664-676页

作者： Xingxing Wang Kaiyan ren Kairui Jiao Wenjun nie Xiaochi An Bin Lian College of Life Sciences College of Marine Science and EngineeringNanjing Normal UniversityNanjing 210023China

The development of bio-adsorbents with highly selective immobilization properties for specific heavy metals is a great challenge,but has important application *** whewellite(BW)with high selectivity for Pb(Ⅱ)was synthesized by mineral microbial *** selective immobilization properties and mechanism of BW for Pb(Ⅱ)were analyzed by combining mineral characterization technology and batch adsorption research *** results indicated that BW can efficiently and selectively immobilize Pb(Ⅱ)in single or composite heavy metal adsorption solutions,and the immobilized Pb(Ⅱ)is difficult to *** undergoes monolayer adsorption on Pb(Ⅱ),Qmax≈1073.17 mg/*** immobilization of Pb(Ⅱ)by BW is a physico-chemical adsorption process with spontaneous heat absorption and an accompanying increase in *** addition,the sequestration of Pb(Ⅱ)by BW remains around 756.99 mg/g even at p H=*** excellent selective immobilization properties of BW for Pb(Ⅱ)are closely related to its smaller Ksp,electrostatic repulsion effect,organic-inorganic composite structure,acid resistance and the formation of Pb(Ⅱ)*** study provides beneficial information about the recycling of lead in acidic lead-containing wastewater and composite heavy metal contaminated water bodies.

关键词： Aspergillus niger Biogenic whewellite Pb(Ⅱ) Selective adsorption Immobilization mechanism

Microstructure, mechanical properties and corrosion behavior of commercial 7N01 alloys

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Transactions of Nonferrous Metals Society of China 2022年第3期32卷 778-789页

作者： Pei-hao ZHAO Xiao-lan WU Yang LIU Kun-yuan GAO Sheng-ping WEN Wu WEI Li RONG Hui HUANG Hong WU De-jing ZHOU Qian ZHANG zuo-ren nie Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Jiangsu Key Laboratory for Clad Materials Yin Bang Clad Material Co.Ltd.Wuxi 214145China Metal&Chemistry Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China

The effect of grain morphology and precipitates on mechanical properties and corrosion behavior of two commercial 7 N01 alloys was studied using transmission electron microscopy(TEM) and scanning electron microscopy(SEM) equipped with electron backscatter diffraction(EBSD). Results showed that the recrystallization degree of the outer surface of 7 N01-I alloy was lower than that of 7 N01-II alloy. The main strengthening precipitates of two alloys were mainly η’ phases. The grain boundary precipitates(GBPs) of 7 N01-I alloy distributed discontinuously, while those of 7 N01-II alloy distributed continuously. The strength of two 7 N01 alloys was similar, but the maximum corrosion depth of 7 N01-I alloy was less than that of 7 N01-II alloy, because the discontinuous GBPs and the lower recrystallization degree of outer surface of 7 N01-I alloy were favorable for improving corrosion behavior. Different models of strengthening mechanism were discussed, and the corrosion behavior was correlated with microstructure.

关键词： 7N01 alloys microstructure mechanical properties corrosion behavior

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Photonics Research 2024年第4期12卷 804-812页

作者： XIAOYU nie HAOTIAN SONG WENHAN ren ZHEDONG ZHANG TAO PENG MARLAN O.SCULLY Institute for Quantum Science and Engineering Texas A&M UniversityCollege StationTexas 77843USA School of Physics Xi’an Jiaotong UniversityXi’an 710049China Department of Physics City University of Hong KongHong KongChina Baylor University WacoTexas 76706USA

The generation of speckle patterns via random matrices, statistical definitions, or apertures may not always result in optimal outcomes. Issues such as correlation fluctuations in low ensemble numbers and diffraction in long-distance propagation can arise. Instead of improving results of specific applications, our solution is catching deep correlations of patterns with the framework, Speckle-Net, which is fundamental and universally applicable to various systems. We demonstrate this in computational ghost imaging(CGI) and structured illumination microscopy(SIM). In CGI with extremely low ensemble number, it customizes correlation width and minimizes correlation fluctuations in illuminating patterns to achieve higher-quality images. It also creates non-Rayleigh nondiffracting speckle patterns only through a phase mask modulation, which overcomes the power loss in the traditional ring-aperture method. Our approach provides new insights into the nontrivial speckle patterns and has great potential for a variety of applications including dynamic SIM, X-ray and photo-acoustic imaging, and disorder physics.

关键词： CGI Deep ghost

Cavity-enhanced photoacoustic dual-comb spectroscopy

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Light(Science & Applications) 2024年第4期13卷 610-618页

作者： Zhen Wang Qinxue nie Haojia Sun Qiang Wang Simone Borri Paolo De Natale Wei ren Department of Mechanical and Automation Engineering The Chinese University of Hong KongNew TerritoriesHong Kong SARChina. State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of Sciences130033 ChangchunChina. CNRINO-Istituto Nazionale di Ottica and LENS-European Laboratory for Nonlinear Spectroscopy50019 Sesto FiorentinoItaly

Photoacoustic dual-comb spectroscopy(DCS),converting spectral information in the optical frequency domain to the audio frequency domain via multi-heterodyne beating,enables background-free spectral measurements with high resolution and broad ***,the detection sensitivity remains limited due to the low power of individual comb lines and the lack of broadband acoustic ***,we develop cavity-enhanced photoacoustic DCS,which overcomes these limitations by using a high-finesse optical cavity for the power amplification of dual-frequency combs and a broadband acoustic resonator with a flat-top frequency *** demonstrate high-resolution spectroscopic measurements of trace amounts of C2H2,NH3 and CO in the entire telecommunications *** method shows a minimum detection limit of 0.6 ppb C2H2 at the measurement time of 100 s,corresponding to the noise equivalent absorption coefficient of 7×10−10 cm−*** proposed cavityenhanced photoacoustic DCS may open new avenues for ultrasensitive,high-resolution,and multi-species gas detection with widespread applications.

关键词： individual cavity spectroscopy

Intertwined depressive and cognitive trajectories and the risk of dementia and death in older adults:a competing risk analysis

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General Psychiatry 2024年第2期37卷 207-215页

作者： Ziyang ren Lirong nie Yushan Du Jufen Liu Institute of Reproductive and Child Health/National Health Commission Key Laboratory of Reproductive Health Peking UniversityBeijingChina Department of Epidemiology and Biostatistics School of Public HealthPeking UniversityBeijingChina

Background Depressive symptoms and cognitive impairment often interact,rendering their associations *** date,their joint trajectories and associations with dementia and death remain *** To explore the interactions between depressive symptoms and cognitive function,their developmental trajectories and the associations with all-cause dementia,Alzheimer’s disease(AD)and all-cause death in older *** Data were from the Health and Retirement *** symptoms and cognitive function were measured using the 8-item Centre for Epidemiologic Studies Depression Scale and the Telephone Interview of Cognitive Status,***-cause dementia and AD were defined by self-reported or proxy-reported physician ***-cause death was determined by *** restricted cubic spline,group-based trajectory modelling and subdistribution hazard regression were *** Significant interactions between depressive symptoms and cognitive function in 2010 in their association with new-onset all-cause dementia and AD from 2010 to 2020 were found,especially in women(p for interaction<0.05).Independent trajectory analysis showed that emerging or high(vs no)depressive trajectories and poor or rapidly decreased cognitive trajectories(vs very good)from 1996 to 2010 were at significantly higher risk of subsequent all-cause dementia,AD and all-cause death.15 joint trajectories of depressive symptoms and cognitive function from 1996 to 2010 were determined,where rapidly decreased cognitive function was more common in those with no depressive *** with older adults with the trajectory of no depressive symptoms and very good cognitive function,those with the trajectory of no depressive symptoms but rapidly decreased cognitive function were much more likely to develop new-onset all-cause dementia and death,with subdistribution hazard ratios(95%confidence intervals)of 4.47(2.99 to 6.67)and 1.84(1.43 to 2.36),especially in wome

关键词： death analysis rendering

Utilizing resequencing big data to facilitate Brassica vegetable breeding:tracing introgression pedigree and developing highly specific markers for clubroot resistance

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Horticultural Plant Journal 2024年第3期10卷 771-783页

作者： Zhiyong ren Jinquan Li Xingyu Zhang Xingxu Li Junhong Zhang Zhibiao Ye Yuyang Zhang Qijun nie Key Laboratory of Vegetable Ecological Cultivation on Highland Ministry of Agriculture and Rural AffairsHubei Key Laboratory of Vegetable Germplasm Enhancement and Genetic ImprovementInstitute of Economic CropsHubei Academy of Agricultural SciencesWuhanHubei 430063China National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops Huazhong Agricultural UniversityWuhanHubei 430070China Vegetable Research Institute Wuhan Academy of Agricultural SciencesWuhanHubei 430345China Hubei Hongshan Laboratory WuhanHubei 430070China Shenzhen Institute of Nutrition and Health Huazhong Agricultural UniversityWuhanHubei 430070China Shenzhen Branch Guangdong Laboratory for Lingnan Modern AgricultureGenome Analysis Laboratory of the Ministry of AgricultureAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenGuangdong 518000China

Clubroot caused by Plasmodiophora brassicae is a devastating disease of Cruciferous *** cultivars with clubroot resistance(CR)is the most effective control *** the two major Brassica vegetable species *** and ***,several commercial cultivars with unclear CR pedigrees have been intensively used as CR donors in ***,the continuous occurrence of CR-breaking makes the CR pedigree underlying these cultivars one of the breeders'most urgent *** complex intraspecific diversity of these two major Brassica vegetables has also limited the applicability of CR markers in different breeding *** we first traced the pedigree underlying two kinds of CR that have been widely applied in breeding by linkage and introgression analyses based on public resequencing *** ***,a major locus CRzi8 underlying the CR of the commercial CR donor‘DegaoCR117’was ***8 was further shown to have been introgressed from turnip(*** ***)and that it carried a potential functional allele of *** turnip introgression carried CRb^(c),sharing the same coding sequence with the CRb that was also identified from chromosome C07 of *** CR cultivars with different *** natural populations,variation analysis of linkage intervals of CRzi8,PbBa8.1,CRb,and CRb^(c)yielded easily resolved InDel markers(>20 bp)for these fundamental CR *** specificity of these markers was tested in diverse cultivars panels,and each exhibited high reliability in *** research demonstrates the value of the practice of applying resequencing big data to solve urgent concerns in breeding programs.

关键词： Brassica Clubroot resistance Resequencing Introgression analysis Molecular marker