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Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)-Ce_(0.9)Gd_(0.1)O_(2-δ)中低温固体氧化物燃料电池复相阴极的研究

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无机材料学报 2018年第4期33卷 441-446页

作者：罗凌虹胡佳幸程亮徐序吴也凡林囿辰景德镇陶瓷大学江西省燃料电池材料与器件重点实验室景德镇333403

采用溶胶-凝胶法制备Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3–δ)(BSCF)粉体后,使用Ce_(0.9)Gd_(0.1)O_(2–δ)(GDC)溶胶包裹BSCF粉的方法制备疏松多孔的BSCF-x GDC(x=30wt%,40wt%,50wt%)复相阴极。通过X射线衍射仪、场发射扫描电镜和透射电镜对复相阴极的物相组成、单电池断面形貌及GDC对BSCF颗粒的包裹形貌进行表征。利用阻抗谱测试研究了复相阴极材料的电化学性能,讨论了掺入GDC量对阴极性能的影响。结果表明:通过GDC溶胶包裹BSCF粉体的制备方法改善了阴极的电化学性能,在同一温度下,BSCF-40GDC阴极的极化电阻最小,在650℃时阴极极化阻抗约为0.397?·cm^2;以BSCF-40GDC为阴极制备的单电池,以H_2+3%H_2O为燃料气、空气为氧化气体,650℃下电池的最大功率密度为0.514 W/cm^2,欧姆电阻为0.257?·cm^2,两极极化电阻为0.0588?·cm2。

关键词： SOFC 复相阴极材料 BSCF-GDC 电化学性能

Serial structure multi-task learning method for predicting reservoir parameters

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Applied Geophysics 2022年第4期19卷 513-527,604页

作者： xu Bin-Sen Li Ning Xiao Li-Zhi Wu Hong-liang Feng-Zhou Wang Bing Wang Ke-Wen College of Geophysics China University of PetroleumBeijing 102249China Research Institute of Petroleum Exploration and Development PetroChina Co Ltd.Beijing 100083China School of Artificial Intelligence China University of PetroleumBeijing 102249China PetroChina Logging Academician Workstation Beijing 100083China

Buiding data-driven models using machine learning methods has gradually become a common approach for studying reservoir *** these methods,deep learning methods are highly *** the perspective of multi-task learning,this paper uses six types of logging data—acoustic logging(AC),gamma ray(GR),compensated neutron porosity(CNL),density(DEN),deep and shallow lateral resistivity(LLD)and shallow lateral resistivity(LLS)—that are inputs and three reservoir parameters that are outputs to build a porosity saturation permeability network(PSP-Net)that can predict porosity,saturation,and permeability values *** logging data are obtained from 108 training wells in a medium₋low permeability oilfield block in the western district of ***-Net method adopts a serial structure to realize transfer learning of reservoir-parameter *** with other existing methods at the stage of academic exploration to simulating industrial applications,the proposed method overcomes the disadvantages inherent in single-task learning reservoir-parameter prediction models,including easily overfitting and heavy model-training ***,the proposed method demonstrates good anti-overfitting and generalization capabilities,integrating professional knowledge and *** 37 test wells,compared with the existing method,the proposed method exhibited an average error reduction of 10.44%,27.79%,and 28.83%from porosity,saturation,permeability *** prediction and actual permeabilities are within one order of *** training on PSP-Net are simpler and more convenient than other single-task learning methods discussed in this ***,the findings of this paper can help in the re-examination of old oilfield wells and the completion of logging data.

关键词： Deep learning Multi-task learning Reservoir-parameter prediction

Bio-inspired motion planning for reaching movement of a manipulator based on intrinsic tau jerk guidance

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Advances in Manufacturing 2019年第3期7卷 315-325页

作者： Zhen Zhang xu Yang School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200444People's Republic of China

This study proposed a bio-inspired motion planning approach for the reaching movement of a robot manipulator based on a novel intrinsic tau jerk guidance strategy,which was established by some cognitive science researchers when they studied motion patterns through *** accordance with the rules of human reaching movement,the intrinsic tau jerk guidance strategy ensures continuity of the acceleration;further,it also ensures that its value is zero at the start and end of the *** approach has been implemented on a three-degrees-offreedom 3R planar *** results show that,within a defined time,both the position gap and attitude gap can be reposefully closed,and the curves of joint velocity,acceleration,and driving torque are continuous and *** to the dynamic analysis,the proposed approach tends to consume less *** bioinspired method has the potential to be applied in particular scenarios in the future,such as a mobile robot with a manipulator exploring an unknown environment.

关键词： Bio-inspired Motion planning Manipulator Reaching movement Intrinsic tau jerk guidance

Bayesian sequential state estimation for MIMO-OFDM systems

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Journal of Systems Engineering and Electronics 2010年第1期21卷 148-153页

作者： Maoge xu Yaoliang Song Southwest Electronic Technology Research Institute Chengdu 610036 E R. China School of Electronic Engineering and Optoelectronic Technology Nanjing University of Science and Technology Nanjing 210094 P. R. China

For the estimation of MIMO frequency selective channel, to mitigate the curse of dimensionality, a novel particle filtering scheme combined with time delay domain processing is proposed. In order to extract the time delay domain channel impulse response from the observed signal, the least-squares （LS） and minimum mean squared error （MMSE） criteria are discussed and the comparable performance of LS with MMSE for sample- spaced channel is revealed. Incorporated the dynamical channel model, gradient particle filtering is further introduced to improve the estimation performance. The robustness of the channel estimator for underestimated Doppler frequency and the effectiveness of the new estimation scheme are illustrated through simulation at last.

关键词： channel estimation particle filtering MIMO-OFDM.

Wave Propagation Characteristics in Thick Conventional and Auxetic Cellular Plates

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Acta Mechanica Solida Sinica 2016年第2期29卷 159-166页

作者： Xiaojian xu Zichen Deng Key Laboratory for Special Area Highway Engineering of Ministry of Education School of HighwayChang'an University Department of Engineering Mechanics Northwestern Polytechnical University

Based on Mindlin plate models and Kirchhoff plate models,this study was concerned with the wave propagation characteristics in thick conventional and auxetic cellular structures,with the objective to clarify the effects of negative Poisson＇s ratio,shear factor and orthotropic mechanical properties on the dynamic behaviors of thick *** results revealed that the predictions using variable shear factor in Mindlin plate models resulted in high wave frequencies,which were more significant for plates with negative values of Poisson＇s *** present study can be useful for the design of critical applications by varying the values of Poisson＇s ratio.

关键词： auxetic cellular structure plate frequency shear factor negative Poisson's ratio

Experimental studies on active control of a dynamic system via a time-delayed absorber

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Acta Mechanica Sinica 2015年第2期31卷 229-247页

作者： Jian xu Yixia Sun School of Aerospace Engineering and Applied Mechanics Tongji University

The traditional passive absorber is fully effective within a narrow and certain frequency *** solve this problem,a time-delayed acceleration feedback is introduced to convert a passive absorber into an active *** the inherent and the intentional time delays are *** former mainly comes from signal acquiring and processing,computing,and applying the actuation force,and its value is *** latter is introduced in the controller,and its value is actively ***,the mechanical model is established and the frequency response equations are *** regions of stability are delineated in the plane of control ***,the design scheme of control parameters is performed to help select the values of the feedback gain and time ***,the experimental studies are *** of both negative and positive feedback control are *** results show that the proper choices of control parameters may broaden the effective frequency band of vibration ***,the time-delayed absorber greatly suppresses the resonant response of the primary system when the passive absorber totally *** experimental results are in good agreement with the theoretical predictions and numerical simulations.

关键词： Vibration absorber Time-delayed feedback Vibration control Stability

Prediction of gastric cancer risk by a polygenic risk score of Helicobacter pylori

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World Journal of Gastrointestinal Oncology 2022年第9期14卷 1844-1855页

作者： Xiao-Yu Wang Li-Li Wang Shu-Zhen liang Chao Yang Lin xu Meng-Chao Yu Yi-xuan Wang Quan-Jiang Dong Central Laboratories and Department of Gastroenterology Qingdao Municipal HospitalQingdao UniversityQingdao 266071Shandong ProvinceChina The Center for Microbes Development and HealthCAS Key Laboratory of Molecular Virology and ImmunologyInstitute Pasteur of ShanghaiChinese Academy of SciencesShanghai 200000China

BACKGROUND Genetic variants of Helicobacter pylori(H. pylori) are involved in gastric cancer occurrence. Single nucleotide polymorphisms(SNPs) of H. pylori that are associated with gastric cancer have been reported. The combined effect of H. pylori SNPs on the risk of gastric cancer remains *** To assess the performance of a polygenic risk score(PRS) based on H. pylori SNPs in predicting the risk of gastric *** A total of 15 gastric cancer-associated H. pylori SNPs were selected. The associations between these SNPs and gastric cancer were further validated in 1022 global strains with publicly available genome sequences. The PRS model was established based on the validated SNPs. The performance of the PRS for predicting the risk of gastric cancer was assessed in global strains using quintiles and random forest(RF) methods. The variation in the performance of the PRS among different populations of H. pylori was further *** Analyses of the association between selected SNPs and gastric cancer in the global dataset revealed that the risk allele frequencies of six SNPs were significantly higher in gastric cancer cases than non-gastric cancer cases. The PRS model constructed subsequently with these validated SNPs produced significantly higher scores in gastric cancer. The odds ratio(OR) value for gastric cancer gradually increased from the first to the fifth quintile of PRS, with the fifth quintile having an OR value as high as 9.76(95% confidence interval: 5.84-16.29). The results of RF analyses indicated that the area under the curve(AUC) value for classifying gastric cancer and non-gastric cancer was 0.75, suggesting that the PRS based on H. pylori SNPs was capable of predicting the risk of gastric cancer. Assessing the performance of the PRS among different H. pylori populations demonstrated that it had good predictive power for cancer risk for hp Europe strains, with an AUC value of *** The PRS model based on H. pylori SNPs

关键词： Polygenic risk scores Helicobacter pylori Gastric cancer Single nucleotide polymorphism

High Temperature at Grain-filling Stage Affects Nitrogen Metabolism Enzyme Activities in Grains and Grain Nutritional Quality in Rice

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Rice science 2011年第3期18卷 210-216页

作者： Cheng-gang liang Li-ping CHEN Yan WANG Jia LIU Guang-li xu Tian LI Agronomy College Sichuan Agricultural University Chengdu 611130 China

Rice plants would more frequently suffer from high temperature (HT) stress at the grain-filling stage in future. A japonica rice variety Koshihikari and an indica rice variety IR72 were used to study the effect of high temperature on dynamic changes of glutamine synthetase (GS) activity, glutamate synthase (GOGAT) activity, glutamic oxalo-acetic transminase (GOT) activity, glutamate pyruvate transminase (GPT) activity in grains and grain nutritional quality at the grain-filling stage. Under HT, the activities of GOGAT, GOT, GPT and soluble protein content in grains significantly increased, whereas GS activity significantly decreased at the grain-filling stage. In addition to the increase of protein and amino acids contents, it was suggested that GOGAT, GOT and GPT in grains played important roles in nitrogen metabolism at the grain-filling stage. Since the decrease of GS activity in grains did not influence the accumulations of amino acids and protein, it is implied that GS might not be the key enzyme in regulating glutamine content in grains.

关键词： high temperature nitrogen metabolism enzyme protein amino acid rice

Entanglement and Teleportation of Pair Cat States in Amplitude Decoherence Channel

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Communications in Theoretical Physics 2009年第7期52卷 45-49页

作者： xu Hang-Shi xu Jing-Bo Zhejiang Institute of Modern Physics and Physics Department Zhejiang University Hangzhou 310027 China

The dynamic behavior of the entanglement for the pair cat states in the amplitude decoherence channel isstudied by adopting the entanglement of formation determined by the ***,we consider the teleportationby using joint measurements of the photon-number sum and phase difference with the pair cat states as an entangleresource and discuss the influence of amplitude decoherence on the mean fidelity of the teleportation.

关键词： entanglement teleportation pair cat states