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Journal of Magnesium and Alloys 2024年第1期12卷 197-208页

作者： Yingyan Zhao zhibing liu Jiangchuan liu Yunfeng Zhu Jiguang Zhang Yana liu Xiaohui Hu Liquan Li College of Materials Science and Engineering Nanjing Tech University30 South Puzhu RoadNanjing211816PR China Jiangsu Collaborative Innovation Centre for Advanced Inorganic Function Composites Nanjing Tech UniversityNanjing211816PR China

The hydrogen absorption/desorption kinetic properties of MgH_(2)can be effectively enhanced by doping specific catalysts.In this work,MOFs-derived NiCu@C nanoparticles(~15 nm)with regular core-shell structure were successfully prepared and introduced into MgH_(2)(denoted as MgH_(2)-NiCu@C).The onset and peak temperatures of hydrogen desorption of MgH_(2)-11 wt.%NiCu@C are 175.0℃and282.2℃,respectively.The apparent activation energy of dehydrogenated reaction is 77.2±4.5 kJ/mol for MgH_(2)-11 wt.%NiCu@C,which is lower than half of that of the as-milled MgH_(2).Moreover,MgH_(2)-11 wt.%NiCu@C displays great cyclic stability.The strengthening"hydrogen pumping"effect of reversible solid solutions Mg_(2)Ni(Cu)/Mg_(2)Ni(Cu)H_(4)is proposed to explain the remarkable improvement in hydrogen absorption/desorption kinetic properties of MgH_(2).This work offers a novel perspective for the design of bimetallic nanoparticles and beyond for application in hydrogen storage and other energy related fields.

关键词： Magnesium hydride Reversible solid solution Core-shell nanoparticles Hydrogen storage performance

Early chatter identification based on optimized VMD with multi-band information fusion and compression method in robotic milling process

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Chinese Journal of Aeronautics 2024年第6期37卷 464-484页

作者： Sichen CHEN Zhiqiang LIANG Yuchao DU Zirui GAO Haoran ZHENG zhibing liu Tianyang QIU Xibin WANG School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

Undesirable self-excited chatter has always been a typical issue restricting the improvement of robotic milling quality and efficiency.Sensitive chatter identification based on processing signals can prompt operators to adjust the machining process and prevent chatter damage.Compared with the traditional machine tool,the uncertain multiple chatter frequency bands and the band-moving of the chatter frequency in robotic milling process make it more challenging to extract chatter information.This paper proposes a novel method of chatter identification using optimized variational mode decomposition(OVMD)with multi-band information fusion and compression technology(MT).During the robotic milling process,the number of decomposed modes k and the penalty coefficient a are optimized based on the dominant component of frequency scope partition and fitness of the mode center frequency.Moreover,the mayfly optimization algorithm(MA)is employed to obtain the global optimal parameter selection.In order to conquer information collection about the uncertain multiple chatter frequency bands and the band-moving of the chatter frequency in robotic milling process,MT is presented to reduce computation and extract signal characteristics.Finally,the cross entropy of the image(CEI)is proposed as the final chatter indicator to identify the chatter occurrence.The robotic milling experiments are carried out to verify the proposed method,and the results show that it can distinguish the robotic milling condition by extracting the uncertain multiple chatter frequency bands and overcome the band-moving of the chatter frequency in robotic milling process.

关键词： Robotic milling Chatter detection Variational mode decomposition Information fusion and compression Chatter featur

A plastic strain energy method exploration between machined surface integrity evolution and torsion fatigue behaviour of low alloy steel

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Chinese Journal of Aeronautics 2022年第10期35卷 412-429页

作者： Yong WANG Xibin WANG zhibing liu Shuyao liu Sitao WANG Hongtao CHEN Ci SONG Yifan BAI Pai WANG Yang liu School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Fundamental Science for Advanced Machining Beijing Institute of TechnologyBeijing 100081China Beijing North Vehicle Group Corporation Beijing 100072China

To explore the evolution mechanism of multistage machining processes and torsional fatigue behaviour based on strain energy for the first time and provide process optimization of axis parts of low alloy steel for service performance,four multistage machining processes were applied to the 45Cr Ni Mo VA steel,including the Rough Turning process(RT),RT+the Finish Turning process(FRT),FRT+the Grinding process(GFRT)and RT+the Finish Turning process on dry cutting condition(FRT0).The result showed that the FRT process’s average low-cycle torsional fatigue life increased by 50%when it evolved from the RT process.The lower surface roughness of R1.3μm caused the total strain energy to increase by 163.8 Pa mm/mm instead of the unchanged strain energy density,and the crack feature evolved from some specific bulges to flat shear plane characteristics.When the GFRT process evolved from the FRT process,its average fatigue life increased by 1.45 times,compared with the RT process.Plastic strain amplitude decreased by 21%,and the strain energy density decreased by 4%due to more considerable compressive residual stress(-249 MPa).Plastic deformation layer depth had a consistent tendency with surface roughness.In this paper,surface integrity evolutions on cyclic characteristics and fatigue behaviour have also been explained.A fatigue life prediction model based on the energy method for machined surface integrity is proposed.

关键词： Cyclic hysteresis loop Multistage machining processes Strain energy Surface integrity evolution Torsional fatigue

Influence of laser shock peening on surface integrity and tensile property of high strength low alloy steel

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Chinese Journal of Aeronautics 2021年第6期34卷 199-208页

作者： Yong WANG Xiaoyu PAN Xibin WANG zhibing liu Shuyao liu Wenjuan WAN Puyi WANG School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China

Laser Shock Peening(LSP)is a well-established surface treatment commonly used to improve mechanical properties of material’s surfaces.To further understand the relationship between tensile property and fatigue life improvement of high strength low alloy steel in the LSP process,LSP treatment of 32 CrNi high strength low alloy steel was carried out by YAG laser with pulse energy of 15 J,and tensile property was tested by electronic universal material testing machine.Surface morphology,residual stress and tensile fracture of the specimens before and after LSP were observed by white light interferometer(WLI),X-ray measuring apparatus and scanning electron microscope(SEM).Result shows that LSP did not change tensile strength of 32 CrNi steel but cause yield characteristic transform from obvious yield point to no yield phenomenon which is the only factor benefiting fatigue life,indicating that the increment of fatigue life was probably related to the disappearance of yield phenomenon.Formation mechanisms of tensile fractures and yield phenomenon induced by LSP at room temperature were also discussed and completely revealed.Deeper compressive residual stress and flat grains contributed to the transition of yield characteristic and lower elongation rate of 32 CrNi steel subjected to LSP.

关键词： 32CrNi steel Laser shock peening Residual stress Tensile property Yield characteristic

Mesoscale fabrication of a complex surface for integral impeller blades

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Frontiers of Mechanical Engineering 2017年第1期12卷 116-131页

作者： Xibin WANG Tianfeng ZHOU Lijing XIE Li JIAO zhibing liu Zhiqiang LIANG Pei YAN Key Laboratory of Fundamental Science for Advanced Machining Beijing Institute of Technology Beijing 100081 China

Integral impeller is the most important compo- nent of a mini-engine. However, the machining of a mesoscale impeller with a complex integral surface is difficult because of its compact size and high accuracy requirement. A mesoscale component is usually manufac- tured by milling. However, a conventional milling tool cannot meet the machining requirements because of its size and stiffness. For the fabrication of a complex integral impeller, a micro-ball-end mill is designed in accordance with the non-instantaneous-pole envelope principle and manufactured by grinding based on the profile model of the helical groove and the mathematical model of the cutting edge curve. Subsequently, fractal theory is applied to characterize the surface quality of the integral impeller. The fractal theory-based characterization shows that the completed mesoscale integral impeller exhibits a favorable performance in terms of mechanical properties and morphological accuracy.

关键词： mesoscale fabrication micro-milling tool,mesoscale milling impeller blade

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高温合金短电弧辅助铣削表面完整性演化研究

机械工程学报 2024年第9期60卷 434-444页

作者：王湃白翌帆赵文祥张毅博刘志兵北京理工大学机械与车辆学院北京100081 北京计算机技术及应用研究所北京100854 北京动力机械研究所北京100074

短电弧铣削加工技术因低加工应力、低成本、高加工效率而被应用在镍基高温合金加工中。针对短电弧辅助精密铣削加工表面完整性演化规律不明的问题,利用扫描电子显微镜(SEM)、能量色散X射线谱(EDS)等检测手段分析了重铸层的组织特性,开... 详细信息

短电弧铣削加工技术因低加工应力、低成本、高加工效率而被应用在镍基高温合金加工中。针对短电弧辅助精密铣削加工表面完整性演化规律不明的问题,利用扫描电子显微镜(SEM)、能量色散X射线谱(EDS)等检测手段分析了重铸层的组织特性,开展正交铣削试验研究了精密铣削工艺参数对表面完整性的影响规律以及重铸层导致的铣削表面差异,探究了短电弧辅助精密铣削表面强化机制。结果表明,高温合金晶体在高温下破坏重组导致其组织变化形成重铸层,硬度降低34%,脆性增强;相同参数下短电弧辅助铣削表面表现出更高的粗糙度值(Ra=0.76μm)、更高的表面硬化率(47.8%)与更大的残余拉应力值(沿进给方向(X向)为241.5 MPa,垂直进给方向(Y向)为78 MPa)。加工表面硬化的主要机制是位错强化,通过引入核心平均取向差参数建立的显微硬度预测模型进一步拓展了表面完整性与晶体学特征的关系。

关键词：短电弧重铸层表面完整性显微硬度表面强化

Effect of bubble morphology and behavior on power consumption in non-Newtonian fluids’aeration process

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Chinese Journal of Chemical Engineering 2024年第1期65卷 243-254页

作者： Xiemin liu Jing Wan Jinnan Sun Lin Zhang Feng Zhang zhibing Zhang Xinyao Li Zheng Zhou Key Laboratory of Mesoscopic Chemistry of Ministry of Education(MOE) School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Dalian Research Institute of Petroleum and Petrochemicals SINOPECDalian 116045China

Due to a prolonged operation time and low mass transfer efficiency, the primary challenge in the aeration process of non-Newtonian fluids is the high energy consumption, which is closely related to the form and rate of impeller, ventilation, rheological properties and bubble morphology in the reactor. In this perspective, through optimal computational fluid dynamics models and experiments, the relationship between power consumption, volumetric mass transfer rate(kLa) and initial bubble size(d0) was constructed to establish an efficient operation mode for the aeration process of non-Newtonian fluids. It was found that reducing the d0could significantly increase the oxygen mass transfer rate, resulting in an obvious decrease in the ventilation volume and impeller speed. When d0was regulated within 2-5 mm,an optimal kLa could be achieved, and 21% of power consumption could be saved, compared to the case of bubbles with a diameter of 10 mm.

关键词： Non-Newtonian fluids aeration process Power consumption Volumetric mass transfer rate Bubble size

Clinical diagnostic performance of the simultaneous amplification and testing methods for detection of the Mycobacterium tuberculosis complex for smear-negative or sputum-scarce pulmonary tuberculosis in China

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Chinese Medical Journal 2014年第10期127卷 1863-1867页

作者： Fan Lin Zhang Qing Cheng Liping liu zhibing Ji Xiaobing Cui Zhenling Ju Jingliang Xiao Heping Tuberculosis Center for Diagnosis and Treatment Shanghai Pulmonary Hospital Tongji University School of Medicine Shanghai 200433 China Shanghai Key Laboratory of Tuberculosis Shanghai Pulmonary Hospital Tongji University School of Medicine Shanghai 200433 China Shanghai Rendu Biotechnology Co. Ltd. Shanghai 201201 China

Background Early detection of pulmonary tuberculosis （PTB） is a big challenge in smear negative and sputum scarce patients in China.Simultaneous amplification and testing methods for detection of the Mycobactedum tuberculosis （MTB） complex （SAT-TB assay） is a novel molecular technique established in our hospital.This method has a high sensitivity and specificity in the lab.In this study,the clinical diagnostic performance of this method in smear-negative or sputum-scarce PTB suspects was investigated and evaluated.Methods Two hundred smear negative and 80 sputum-scarce patients were recruited in this study.Samples that included sputum or bronchial washing fluid were collected and sent for both bacteria culture and SAT-TB assay.Diagnosis for these patients was based on the comprehensive evaluation of chestX-ray/CT study,histology examination,lab results,and treatment response.Sensitivity,specificity,positive predictive value （PPV） and negative predictive value （NPV） for each diagnostic test were investigated and calculated using confirmed tuberculosis （TB） and non-TB cases.The time required for detection of MTB was also measured for each method.Results Ninety-two patients （33％） were diagnosed as definitive TB,112 patients （40％） were probable PTB,and 76 （27％） were non-TB.The sensitivity,specificity,PPV,and NPV of SAT-TB in smear-negative PTB suspects were 93％（95％ CI,84％-98％）,98％（95％ CI,90％-100％）,98％（95％ Cl,91％-100％）,and 93％（95％ CI,83％-98％）.In sputum scarce PTB suspects,the sensitivity,specificity,PPV,and NPV of the SAT-TB assay on bronchial washing fiuids were 90％（95％Cl,74％-98％）,100％（95％ Cl,85％-100％）,100％（95％ Cl,88％-100％）,and 88％（95％ CI,69％-97％）.The accuracy of the SAT-TB assay is consistent with the bacteria culture assay.The median time required for detecting MTB in the SAT-TB assay was 0.5 day,which was much faster than bacteria culture （28 days）.Conclusions The SAT-TB assay is a fast and accurate method for the detection of MTB.It can be widely applied in the clinic and be an asset in early detection an

关键词： nucleic acid amplification techniques smear-negative sputum scarce diagnosis tuberculosis

High-quality assembled and annotated genomes of Nicotiana tabacum and Nicotiana benthamiana reveal chromosome evolution and changes in defense arsenals

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Molecular Plant 2024年第3期17卷 423-437页

作者： Jubin Wang Qingling Zhang Jeffrey Tung Xi Zhang Dan liu Yingtian Deng Zhendong Tian Huilan Chen Taotao Wang Weixiao Yin Bo Lij zhibing Lai Savithramma P.Dinesh-Kumar Barbara Baker Feng Li National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops College of Horticulture and Forestry SciencesHuazhong Agricultural UniversityWuhanHubei 430070China Plant Gene Expression Center Department of Plant and Microbial BiologyUniversity of CaliforniaBerkeleyBerkeleyCA 94706USA College of Plant Science and Technology Huazhong Agricultural UniversityWuhanHubei 430070China College of Life Science and Technology Huazhong Agricultural UniversityWuhanHubei 430070China Department of Plant Biology and The Genome Center College of Biological SciencesUniversity of CalforniaDavisDavisCA 95616USA The Key Laboratory of Horticultural Plant Genetic and Improvement of Jiangxi Province Institute of Biological ResourcesJiangxi Academy of SciencesNanchang 330299China institute of Vegetables and Flowers Jiangxi Academy of Agricultural SciencesNanchang 330200Chin Hubei Hongshan Laboratory WuhanHubei 430070China

Nicotiana tabacum and Nicotiana benthamiana are widely used models in plant biology research.However,genomic studies of these species have lagged.Here we report the chromosome-level reference genome assemblies for N.benthamiana and N.tabacum with an estimated 99.5%and 99.8%completeness,respec-tively.Sensitive transcription start and termination site sequencing methods were developed and used for accurate gene annotation in N.tabacum.Comparative analyses revealed evidence for the parental origins and chromosome structural changes,leading to hybrid genome formation of each species.Interestingly,theantiviral silencinggenesRDR1,RDR6,DCL2,DCL3,andAGO2were lost from one or both subgenomes in N.benthamiana,while both homeologs were kept in N.tabacum.Furthermore,the N.benthamiana genome encodes fewer immune receptors and signaling components than that of N.tabacum.These find-ings uncover possible reasons underlying the hypersusceptible nature of N.benthamiana.We developed the user-friendly Nicomics(http:/***/Nicomics/)web server to facilitate better use of Nicotiana genomic resources as well as gene structure and expression analyses.

关键词： Nicotiana tabacum Nicotiana benthamiana genomics evolution disease resistance NLR

Ecological and environmental explanation of microbiotic crusts on sand dune scales in the Gurbantonggut Desert, Xinjiang

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Progress in Natural Science:Materials International 2005年第12期15卷 1089-1095页

作者： CHEN Yaning,LI Weihong,ZHOU zhibing and liu Jiazhen Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China

Results obtained from the field investigation and the analysis in laboratory show that many species of microbiotic crusts of lichens,mosses and algae develop extensively in the Gurbantonggut Desert,Xinjiang.The formation,species and distribution are closely related to the environmental conditions at the different positions of sand dunes.The animalcule crusts develop mainly on the mobile or semi-mobile sand surface of dune tops,the alga crusts develop mainly at the upper to middle parts of dune slopes,the lichen crusts develop at middle and lower parts of dune slopes,and the moss crusts are mainly distributed at the lower part of dune slopes and the interdune lowlands.The species,thickness and developing degree of microbiotic crusts increase from the upper part to the middle and lower parts of dune slopes and the interdune lowlands,and an obvious contrast between the microbiotic crusts and the different species of plant communities forms.The development and differentiation of microbiotic crusts at the different positions of dunes are the ecological appearance and the natural selection of synthetic adaptability of the different microbiotic crust species to the local environmental conditions,and are closely related to the ecological conditions,such as the physiochemical properties of soils and stability of topsoil texture.

关键词： microbiotic crust sand done scales environmental explanation the Gurbantonggut Desert