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Effects of chloride on electrochemical and stress corrosion cracking behavior of 9Cr ferritic-martensitic steel

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Journal of Iron and Steel Research International 2020年第6期27卷 719-731页

作者： zhen Zhang zheng-fei Hu Liang He xiao-bo Zhang Xin-xian Fang Bao-sen Zhang Zhi-xin Ba Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing 211167JiangsuChina School of Materials Science and Engineering Nanjing Institute of TechnologyNanjing 211167JiangsuChina School of Materials Science and Engineering Tongji UniversityShanghai 201804China School of Materials Science and Engineering Georgia Institute of TechnologyAtlanta 30332-0620USA

The electrochemical and stress corrosion cracking behavior of 9Cr ferritic-martensitic steel is investigated in the chloride environment by using the traditional electrochemical method, the scanning vibrating electrode technique and the slow strain rate test (SSRT). Results of the static corrosion tests and corrosion morphology show that the prior austenite grain boundaries and martensite lath boundaries are the preferred sites for pit nucleation and growth in chloride environment. Results of SSRT coupled with insitu electrochemical test show that the transition from pitting corrosion to uniform corrosion, as well as the nucleation of stress corrosion crack, is the synergistic effects of the chloride and applied load. Stress corrosion cracking of the steel in the chloride environment can be divided into three different regions as follows: fast and uniform corrosion activ-ity, microcrack nucleation and propagation, and active crack growth regions.

关键词： 9Cr ferritic-martensitic steel Chloride In situ electrochemical test Scanning vibrating electrode technique Stress corrosion cracking

A fast registration algorithm of rock point cloud based on spherical projection and feature extraction

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Frontiers of Computer Science 2019年第1期13卷 170-182页

作者： Yaru xian Jun xiao Ying WANG School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China

Point cloud registration is an essential step in the process of 3D *** this paper,a fast registration algorithm of rock mass point cloud is proposed based on the improved iterative closest point (ICP)*** our proposed algorithm,the point cloud data of single station scanner is transformed into digital images by spherical polar coordinates,then image features are extracted and edge points are removed,the features used in this algorithm is scale-invariant feature transform (SIFT).By analyzing the corresponding relationship between digital images and 3D points,the 3D feature points are extracted,from which we can search for the two-way correspondence as candidates. After the false matches are eliminated by the exhaustive search method based on random sampling,the transformation is computed via the Levenberg-Marquardt-Iterative Closest Point (LM-ICP)*** on real data of rock mass show that the proposed algorithm has the similar accuracy and better registration efficiency compared with the ICP algorithm and other algorithms.

关键词： rock point cloud registration LM-ICP spherical projection feature extraction

基于O'NET半结构化访谈建构大学生职业适应力故事

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高校辅导员学刊 2025年第1期17卷 34-42,97页

作者：林振余权肖龙福建商学院传媒与会展学院福建福州350012

职业适应力是大学生转型为职场人士的关键能力,其中职业兴趣是核心要素。然而,当前对大学生职业兴趣的分析主要局限于定量评估,导致学生对自身职业兴趣的理解较为表面,甚至开始怀疑其价值。研究采用O'NET半结构化访谈,结合主题演绎驱动... 详细信息

职业适应力是大学生转型为职场人士的关键能力,其中职业兴趣是核心要素。然而,当前对大学生职业兴趣的分析主要局限于定量评估,导致学生对自身职业兴趣的理解较为表面,甚至开始怀疑其价值。研究采用O'NET半结构化访谈,结合主题演绎驱动理论,深入分析了大学生在职业适应力故事中的关注、控制、好奇、自信、合作五个维度,旨在探讨半结构化访谈如何定性地将职业兴趣代码与这五个维度的故事关联起来,并揭示其在提升大学生职业适应力方面的作用。研究结果显示,通过半结构化访谈建构的职业适应力故事,成功整合了定量与定性职业兴趣评估,这种方法不仅能帮助大学生更深入地理解自身的霍兰德职业兴趣代码,还能促使他们系统地叙述职业适应力故事,从而有效提升其职业适应力。

关键词：故事建构半结构化访谈职业适应力定性 O'NET

Performance of Forearm FMG and sEMG for Estimating Elbow, Forearm and Wrist Positions

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Journal of Bionic Engineering 2017年第2期14卷 284-295页

作者： zhen Gang xiao Carlo Menon Menrva Research Group Schools of Mechatronic Systems Engineering and Engineering Science Simon Fraser University British Columbia V3T0A3 Canada

The ability to track upper extremity movement during activity of daily living has the potential to facilitate the recovery of individuals with neurological or physical injuries. Hence, the use of Surface Electromyography （sEMG） signals to predict upper extremity movement is an area of interest in the research community. A less established technique, Force Myography （FMG）, which uses force sensors to detect forearm muscle contraction patterns, is also able to detect some movements of the arm. This paper investigates the comparative performance of sEMG and FMG when predicting wrist, forearm and elbow positions using signals extracted from the forearm only. Support Vector Machine （SVM） and Linear Discriminant Analysis （LDA） classifiers were used to evaluate the prediction performance of both FMG and sEMG data. Ten healthy volunteers participated in this study. Under a cross validation across a repetition evaluation scheme, the SVM classifier obtained averaged accuracies of 84.3%, 82.4% and 71.0%, respectively, for predicting elbow, forearm and wrist positions using FMG; while sEMG yielded 75.4%, 83.4% and 92.4% accuracies for predicting the same respective positions. The accuracies obtained using SVM are slightly, but statistical significantly, higher than the ones obtained using LDA. However, the trends on the classification performances between FMG and sEMG are consistent. These results also indicate that the forearm FMG pattern is highly influenced by the change of elbow position, while the forearm sEMG is less subjected to the change. Overall, both forearm FMG and sEMG techniques provide abundant information that can be utilized for tracking the upper extremity movements.

关键词： Surface Electromyography (sEMG) Force Myography (FMG) classification limb movement activity monitoring,upper extremity

A Revised Graduated Cylindrical Shell Model and its Application to a Prominence Eruption

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Research in Astronomy and Astrophysics 2023年第12期23卷 63-72页

作者： Qing-Min Zhang zhen-Yong Hou xian-Yong Bai Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryNanjing 210023China Yunnan Key Laboratory of the Solar Physics and Space Science Kunming 650216China School of Earth and Space Sciences Peking UniversityBeijing 100871China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Solar Activity and Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China

In this paper,the well-known graduated cylindrical shell(GCS)model is slightly revised by introducing longitudinal and latitudinal deflections of prominences originating from active regions(ARs).Subsequently,it is applied to the three-dimensional(3D)reconstruction of an eruptive prominence in AR 13110,which produced an M1.7 class flare and a fast coronal mass ejection(CME)on 2022 September *** is revealed that the prominence undergoes acceleration from~246 to~708 km s^(-1).Meanwhile,the prominence experiences southward deflection by 15°±1°without longitudinal deflection,suggesting that the prominence erupts *** deflections of the prominence and associated CME are consistent,validating the results of fitting using the revised GCS ***,the true speed of the CME is calculated to be 1637±15 km s^(-1),which is~2.3 times higher than that of *** is indicative of continuing acceleration of the prominence during which flare magnetic reconnection reaches maximum beneath the erupting ***,the reconstruction using the revised GCS model could successfully track a prominence in its early phase of evolution,including acceleration and deflection.

关键词： Sun flares-Sun filaments-prominences-Sun coronal mass ejections(CMEs)

Polymer-to-Monomers Chemically Recyclable Poly(imide-imine)Plastics with Extreme-Condition Resistance and Flame Retardancy

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Chinese Journal of Polymer Science 2024年第10期42卷 1525-1535,I0012页

作者： zhen-Yu Wang xiao-Kong Liu State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun130012China

Polyimides are a family of high-tech plastics that have irreplaceable applications in the fields of aerospace,defense,and opto-electronics,but polyimides are difficult to be reprocessed and recycled at the end of their service life,resulting in a significant waste of ***,it is of great significance to develop recyclable polyimides with comparable properties to the commercial ***,we report a novel polymer-to-monomers chemically recyclable poly(imide-imine)(PtM-CR-PII)plastic,synthesized by cross-linking the amine-terminated aromatic bisimide monomer and the hexa-vanillin terminated cyclophosphazene monomer via dynamic imine *** PtM-CR-PII plastic exhibits comparable mechanical and thermal properties as well as chemical stability to the commercial *** PtM-CR-PII plastic possesses a high Young’s modulus of≈3.2 GPa and a tensile strength as high as≈108 MPa,which also exhibits high thermal stability with a glass transition temperature of≈220℃.Moreover,the PtM-CR-PII plastic exhibits outstanding waterproofness,acid/alkali-resistance,and solvent-resistance,its appearance and mechanical properties can be well maintained after long-term soaking in water,highly concentrated acid and base,and various organic ***,the cyclophosphazene moieties endow the PtM-CR-PII plastic with excellent flame *** PtM-CR-PII plastic exhibits the highest UL-94 flame-retarding rating of V-0 and a limiting oxygen index(LOI)value of 45.5%.Importantly,the PtM-CR-PII plastic can be depolymerized in an organic solvents-acid mixture medium at room temperature,allowing easy separation and recovery of both monomers in high *** recovered pure monomers can be used to regenerate new PtM-CR-PII plastics,enabling sustainable polymer-monomers-polymer circulation.

关键词： Chemical recyclability Polyimides Polyimines Dynamic imine bonds Mechanical properties Chemical stability

A Novel Method to Prepare Potassium Sodium Titanate Nanotubes

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Chinese Chemical Letters 2006年第9期17卷 1275-1278页

作者： xiao Dong WANG zhen Sheng JIN xian Ru PEI Jian Jun YANG Zhi Jun ZHANG State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 Lab of Special Functional Material Henan University Kaifeng 475001 Graduated School of Chinese Academy of Sciences Beijing 100049

A novel method, i.e. molten salt method, was adopted to prepare potassium sodium titanate nanotubes. EDX results indicated that the ion-exchange reaction reached an equilibrium state at around 9 h. The 24 h ion-exchanged product maintained nano-tubular and its crystalline structure was consistent with that of Na2Ti2O4（OH）2 nanotubes. The nanotubes have a high specific surface area, possibly making this material a good candidate as controlled release materials, catalyst, electrode materials, etc..

关键词： Nanotube potassium titanate molten salt.

Precise drag prediction of airfoil flows by a new algebraic model

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Acta Mechanica Sinica 2020年第1期36卷 35-43页

作者： Meng-Juan xiao zhen-Su She State Key Laboratory for Turbulence and Complex Systems College of EngineeringPeking UniversityBeijing100871China

We report the results of accurate prediction of lift(C L)and drag(C D)coefficients of two typical airfoil flows(NACA0012 and RAE2822)by a new algebraic turbulence model,in which the eddy viscosity is specified by a stress length(SL)function predicted by structural ensemble dynamics(SED)*** accuracy of the prediction of C D with error of a few counts(one count is 10−4)and of C L with error under 1%-2%are uniformly obtained for varying angles of attack(AoA),indicating an order of magnitude improvement of drag prediction accuracy compared to currently used models(typically around 20 to 30 counts).More interestingly,the SED-SL model is distinguished with fewer parameters of clear physical meaning,which quantify underlying turbulent boundary layer(TBL)with a universal multi-layer structure,and is thus promising to be more easily generalizable to complex *** use of the new model for the calibration of flow condition in experiment and the extraction of flow physics from numerical simulation data of aeronautic flows are discussed.

关键词： Lift and drag coefficients Airfoil Flows Stress Length Structural ensemble dynamics

A possible explanation of the threshold enhancement in the process e^+e^-→∧■

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Chinese Physics C 2019年第11期43卷 49-57页

作者： Li-Ye xiao Xin-zhen Weng xian-Hui Zhong Shi-Lin Zhu School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China Center of High Energy Physics Peking UniversityBeijing 100871China Department of Physics Hunan Normal Universityand Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of EducationChangsha 410081China Synergetic Innovation Center for Quantum Effects and Applications(SICQEA) Hunan Normal UniversityChangsha 410081China Collaborative Innovation Center of Quantum Matter Beijing 100871China

Inspired by the recent measurement of the process e+e-→∧■,we calculate the mass spectrum of the 0 meson with the GI *** the excited vector strangeonium states ?（3 S,4 S,5 S,6 S） and ?（2 D,3 D,4 D,5 D）,we investigate the electronic decay width with the Van Royen-Weisskopf formula,and the partial widths of the ∧■,■,and■ decay modes with the extended quark-pair creation *** find that the electronic decay width of the D-wave vector strangeonium is about 3～8 times larger than of the S-wave vector *** 2232 Me V,the partial decay width of the ∧■ mode can be up to several MeV for ?（33 S1）,while the partial ∧■ decay width of ?（23 D1） is O(10-3) *** the threshold enhancement reported by the BESIII collaboration arises from the strangeonium meson,this state is very likely the ?（33 S1） *** also note that the ∧■ and∑+■partial decay widths of the states ?（33 D1） and ?（43 S1） are several MeV,which is sufficient to be observed in future experiments.

关键词： spectrum GI mode ΛΛ^-decay