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Transition and fracture shift behavior in LCF test of dissimilar welded joint at elevated temperature

Journal of Materials Science & Technology 2018年第4期34卷 720-731页

作者： Xiongfei Wang ChendongShao Xia Liu fenggui lu Shanghai Key Laboratory of Materials Laser Processing and Modification School of Materials Science and EngineeringShanghaiJiao Tong UniversityShanghai 200240China Shanghai Turbine Plant of Shanghai Electric Power Generation Equipment Co.Ltd. Shanghai 200240China

This work focused on the low-cycle fatigue （LCF） behavior of modified 9Cr/CrMoV dissimilar welded joint at elevated temperature. Narrow gap submerged arc welding （NG-SAW） process via multi-pass and multi-layer techniques was employed to fabricate the welded joint. LCF tests at different strain amplitude range from 0.22% to 0.75% were performed at strain ratio R = -1. The two-slope behavior based on fracture location shift was presented both on the cyclic stress-strain （CSS） curve and Manson-Coffin （M-C） curve, which could be applied to predict the fatigue life more precisely especially at relatively low strain amplitude. The results indicated that the joint failed in CrMoV-base metal （BM） at relatively low strain amplitude below 0.4% while failure shifted to CrMoV-over tempered zone （OTZ） at higher strain amplitude above 0.4%. Fatigue failure occurred in CrMoV-BM at low strain amplitude could be attributed to temperature softening effect in CrMoV-BM combined with cyclic strengthening in CrMoV- OTZ. While CrMoV-OTZ with a comparable number of grain boundaries and much lower hardness than that of CrMoV-BM was deemed to be the weakest zone across the welded joint at higher strain amplitude. EBSD investigations also revealed that CrMoV-BM experienced more fatigue damage at relatively low strain amplitude, while CrMoV-OTZ accumulated more plastic strain at higher strain amplitude.

关键词： Low-cycle fatigue 9Cr/CrMoV dissimilar welded joint Elevated temperature Fracture transition EBSD analysis

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Unsupervised segmentation of medical image based on difference of mutual information

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Science in China(Series F) 2006年第4期49卷 484-493页

作者： lu Qingwen CHEN Wufan School of BME Southern Medical University Guangzhou 510515 China

In the scope of medical image processing, segmentation is important and difficult. There are still two problems which trouble us in this field. One is how to determine the number of clusters in an image and the other is how to segment medical images containing lesions. A new segmentation method called DDC, based on difference of mutual information （dMI） and pixon, is proposed in this paper. Experiments demonstrate that dMI shows one kind of intrinsic relationship between the segmented image and the original one and so it can be used to well determine the number of clusters. Furthermore, multi-modality medical images with lesions can be automatically and successfully segmented by DDC method.

关键词： medical image unsupervised segmentation mutual information pixon.

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Adaptive robust neural control of a two-manipulator system holding a rigid object with inaccurate base frame parameters

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Frontiers of Information Technology & Electronic Engineering 2018年第11期19卷 1316-1327页

作者： Fan XU Jin WANG Guo-dong lu State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang University

The problem of self-tuning control with a two-manipulator system holding a rigid object in the presence of inaccurate translational base frame parameters is addressed. An adaptive robust neural controller is proposed to cope with inaccurate translational base frame parameters, internal force, modeling uncertainties, joint friction, and external disturbances. A radial basis function neural network is adopted for all kinds of dynamical estimation, including undesired internal force. To validate the effectiveness of the proposed approach, together with simulation studies and analysis, the position tracking errors are shown to asymptotically converge to zero, and the internal force can be maintained in a steady range. Using an adaptive engine, this approach permits accurate online calibration of the relative translational base frame parameters of the involved manipulators. Specialized robust compensation is established for global stability. Using a Lyapunov approach, the controller is proved robust in the face of inaccurate base frame parameters and the aforementioned uncertainties.

关键词： Cooperative manipulators Neural networks Inaccurate translational base frame Adaptive control Robust control

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Identification of suitable reference genes in leaves and roots of rapeseed (Brassica napus L.) under different nutrient deficiencies

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Journal of Integrative Agriculture 2017年第4期16卷 809-819页

作者： HAN Pei-pei QIN lu LI Yin-shui LIAO Xiang-sheng XU Zi-xian HU Xiao-jia XIE Li-hua YU Chang-bing WU Yan-feng LIAO Xing Oil Crops Research Institute Chinese Academy of Agricultural Sciences/Key Laboratory of Biology and Genetics Improvement of Oil Crops Ministry of Agriculture Wuhan 430062 P.R. China

Nutrient deficiency stresses often occur simultaneously in soil. Thus, it＇s necessary to investigate the mechanisms underlying plant responses to multiple stresses through identification of some key stress-responsive genes. Quantitative real-time PCR （qRT-PCR） is essential for detecting the expression of the interested genes, of which the selection of suitable reference genes is a crucial step before qRT-PCR. To date, reliable reference genes to normalize qRT-PCR data under different nutrient deficiencies have not been reported in plants. In this study, expression of ten candidate reference genes was detected in leaves and roots of rapeseed （Brassica napus L.） after implementing different nutrient deficiencies for 14 days. These candidate genes, included two traditionally used reference genes and eight genes selected from an RNA- Seq dataset. Two software packages （GeNorm, NormFinder） were employed to evaluate candidate gene stability. Results showed that VHA-E1 was the highest-ranked gene in leaves of nutrient-deficient rapeseed, while VHA-G1 and UBC21 were most stable in nutrient-deficient roots. When rapeseed leaves and roots were combined, UBC21, HTB1, VHA-G1 and A CT7 were most stable among all samples. To evaluate the stabilities of the highest-ranked genes, the relative expression of two target genes, BnTrxl;1 and BnPhtl;3 Were further determined. The results showed that the relative expression of BnTrxl;1 depended on reference gene selection, suggesting that it＇s necessary to evaluate the stability of reference gene prior to qRT-PCR. This study provides suitable reference genes for gene expression analysis of rapeseed responses to different nutrient deficiencies, which is essential for elucidation of mechanisms underlying rapeseed responses to multiple nutrient deficiency stresses

关键词： reference genes rapeseed (Brassica napus L.) nutrient deficiency leaves roots

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Entanglement dynamics of a three-qubit system with different interatomic distances

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Chinese Physics B 2015年第11期24卷 103-109页

作者：封玲娟张英杰张路夏云杰 Shandong Provincial Key Laboratory of Laser Polarization and Information Technology Department of Physics Qufu Normal University Beijing National Laboratory of Condensed Matter Physics Institute of Physics Chinese Academy of Sciences

We investigate the tripartite entanglement dynamics of three two-level atoms in a multi-mode vacuum field. By considering the influences of the interatomic distance and the initial condition on the lower bound of concurrence and the tripartite negativity, we show that an optimal interatomic distance can be found to minimize the collective damping. Interestingly, at the same optimal distance, the tripartite entanglement would be maximized in the open dynamics process. In the case of shorter interatomic distance, the tripartite entanglement can display the oscillatory behavior in the initial short-time limit and be trapped in a stationary value in the long-time limit. In addition, the tripartite entanglement for the general situation with different interatomic distances is also discussed.

关键词： quantum entanglement the lower bound of concurrence W state interatomic distance

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基于多学科优化设计方法的白车身轻量化

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吉林大学学报（工学版） 2015年第1期45卷 29-37页

作者：王登峰卢放吉林大学汽车仿真与控制国家重点实验室长春130022 一汽-大众汽车有限公司技术开发部长春130011

建立某国产轿车的整车有限元模型,依据侧碰法规及NVH性能要求对白车身结构进行了多学科集成优化设计。根据侧碰及NVH仿真结果,选取白车身关键零件的板厚及材料为变量,以白车身质量和刚度为目标,以侧碰加速度及侵入量为约束条件,建立了... 详细信息

建立某国产轿车的整车有限元模型,依据侧碰法规及NVH性能要求对白车身结构进行了多学科集成优化设计。根据侧碰及NVH仿真结果,选取白车身关键零件的板厚及材料为变量,以白车身质量和刚度为目标,以侧碰加速度及侵入量为约束条件,建立了白车身刚度径向基函数(RBF)神经网络近似模型及侧碰二阶逐次替换的响应面模型(Stepwise-RSM),利用模拟退火算法进行了多目标优化,在保证了车辆的安全及NVH性能的前提下使白车身质量下降了15.7 kg。

关键词：车辆工程白车身轻量化多学科优化近似模型

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Density functional theory calculation on the C―H bond insertion reaction of dibromocarbene with acetaldehyde

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Chinese Science Bulletin 2008年第5期53卷 718-726页

作者： LI Zhifeng YANG Sheng lu LingLing lu XiaoQuan KANG JingWan College of Life Science and Chemistry Tianshui Normal University '13anshui 741001 China Gansu Key Laboratory of Polymer Materials College of Chemistry and Chemical Engineering Northwest Normal University Lanzhou 730070 China

The insertion reaction mechanism of CBr_2 with CH_3CH_O has been studied by using the B3LYP/6-31G(d) method. The geometries of reactions, transition state and products were completely optimized. All the energy of the species was obtained at the CCSD(T)/6-31G(d) level. All the transition state is verified by the vibrational analysis and the internal reaction coordinate (IRC) calculations. The results show that the propionaldehyde (~HP1) is the main product of CH_2 insertion with CH_3CH_O. The calculated results indicated that all the major pathways of the reaction were obtained on the singlet potential energy surface. The singlet CBr_2 not only can insert the C_α-H [reaction I(1)]) but also can react with C_β-H [reaction II(1)]. The statistical thermodynamics and Eyring transition state theory with Wigner correc- tion are used to study the thermodynamic and kinetic characters of I(1) and II(1) in temperature range from 100 to 2200 K. The results show that the appropriate reaction temperature rang is 250 to 1750 K and 250 to 1600 K at 1.0 atm for I(1) and II(1) respectively. The rate constant and equilibrium constant are distinct in the range from 250 to 1000 K so that I(1) more easily occurs, while the reactions are not selected in the temperature range of 1000-1600

关键词：密度泛函理论二溴化碳乙醛碳-氢键结合反应

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Automatic removal of false image stars in disk-resolved images of the Cassini Imaging Science Subsystem

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Research in Astronomy and Astrophysics 2020年第7期20卷 93-102页

作者： Qing-feng Zhang Zhi-Cong lu Xiao-Mei Zhou Yang Zheng Zhan Li Qing-Yu Peng Shun Long Wei-Heng Zhu Department of Computer Science Jinan UniversityGuangzhou 510632China Sino-French Joint Laboratory for Astrometry Dynamics and Space ScienceJinan UniversityGuangzhou 510632China

Taking a large number of images,the Cassini Imaging Science Subsystem(ISS)has been routinely used in *** ISS images,disk-resolved objects often lead to false detection of stars that disturb the camera pointing *** aim of this study was to develop an automated processing method to remove the false image stars in disk-resolved objects in ISS *** method included the following steps:extracting edges,segmenting boundary arcs,fitting circles and excluding false image *** proposed method was tested using 200 ISS *** experimental results show that it can remove the false image stars in more than 95%of ISS images with disk-resolved objects in a fully automatic manner,i.e.,outperforming the traditional circle detection based on Circular Hough Transform(CHT)by 17%.In addition,its speed is more than twice as fast as that of the CHT *** is also more robust(no manual parameter tuning is needed)when compared with *** proposed method was also applied to a set of ISS images of Rhea to eliminate the mismatch in pointing correction in automatic *** results showed that the precision of final astrometry results can be improve by roughly 2 times that of automatic procedure without the *** proved that the proposed method is helpful in the astrometry of ISS images in a fully automatic manner.

关键词： methods:data analysis techniques:image processing techniques:telescopes stars:imaging

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Supramolecular Biomaterials for Cancer Immunotherapy

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Research 2024年第2期2023卷 491-509页

作者： Huan Liang Qingqing lu Jie Yang Guocan Yu College of Science Nanjing Forestry UniversityNanjing 210037P.R.China Key Laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology Department of ChemistryTsinghua UniversityBeijing 100084P.R.China

Cancer immunotherapy has achieved tremendous successful clinical results and obtained historic victories in tumor ***,great limitations associated with feeble immune responses and serious adverse effects still cannot be neglected due to the complicated multifactorial etiology and pathologic microenvironment in *** rapid development of nanomedical science and material science has facilitated the advanced progress of engineering biomaterials to tackle critical *** supramolecular biomaterials with flexible and modular structures have exhibited unparalleled advantages of high cargo-loading efficiency,excellent biocompatibility,and diversiform immunomodulatory activity,thereby providing a powerful weapon for cancer *** past decades,supramolecular biomaterials were extensively explored as versatile delivery platforms for immunotherapeutic agents or designed to interact with the key moleculars in immune system in a precise and controllable *** this review,we focused on the crucial role of supramolecular biomaterials in the modulation of pivotal steps during tumor immunotherapy,including antigen delivery and presentation,T lymphocyte activation,tumor-associated macrophage elimination and repolarization,and myeloid-derived suppressor cell *** on extensive research,we explored the current limitations and development prospects of supramolecular biomaterials in cancer immunotherapy.

关键词： biomaterials limitations thereby

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Helicobacter pylori eradication for preventing gastric cancer

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World Journal of Gastroenterology 2014年第19期20卷 5660-5665页

作者： Bin lu Meng Li Department of Gastroenterology the First Affiliated Hospital of Zhejiang Chinese Medical University

Helicobacter pylori(***)infection is a major riskfactor for gastric cancer(GC)development,which isone of the most challenging malignant diseases worldwide with limited *** the multistep pathogenesis of GC,*** infection slowly induces chronicactive gastritis,which progresses through the premalignant stages of atrophic gastritis,intestinal metaplasia,and dysplasia,and then finally to *** eradication of *** is a reasonable approach for the prevention of GC,there have been some contradictory reports,with only some long-term follow-up data showingefficacy of this *** inconsistencies are likely due to the insufficient number of participants,relatively short follow-up periods,poor quality of study designs,and the degree and extent of preneoplastic changes atthe time of *** *** review analyzesrecent high-quality studies to resolve the discrepancies regarding the eradication of *** for GC *** relationship between *** eradication and GC/precancerous lesions/metachronous GC is examined,and the cost-effectiveness of this strategy in the prevention of GC is *** it is assumed that eradication of *** has the potential to prevent GC,the feasibility and appropriate timing of this strategy for cancer prevention remain to be *** a result,additional well-designed trials with longer followup periods are needed to clarify this issue.

关键词： Helicobacter pylori Gastric cancer Cancer prevention

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