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Seam Tracking Technology for Hyperbaric Underwater Welding

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Chinese Journal of Mechanical Engineering 2009年第2期22卷 265-269页

作者： JIAO Xiangdong yang Yongyong ZHOU Canfeng Research Center of Offshore Engineering Joining Technology Beijing Institute of Petrochemical Technology Beijing 102617 China

Automatic weld seam tracking technology to be used in hyperbaric underwater damaged pipeline repair welding is much more important, because of poor bevel preparation and severe working condition. A weld seam tracking system based on digital signal processing（DSP） passive light weld image processing technology has been established. A convenient charge coupled device（CCD） camera system was used in the high pressure environment with the help of an aperture and focus altering mechanism to guarantee overall image visibility in the scope of pressure below 0.7 MPa. The system can be used in the hyperbaric environment to pick up the real welding image of both the welding arc and the welding pool. The newly developed DSP technology was adopted to achieve the goal of system real time characteristics. An effective weld groove edge recognition technique including narrow interesting window opening, middle value wave filtering, Sobel operator weld edge detecting and edge searching in a defined narrow area was proposed to remove the guide error and system accuracy was ensured. The results of tracking simulation and real tracking application with arc striking have proved the validity and the accuracy of the mentioned system and the image processing method.

关键词： hyperbaric underwater welding seam tracking weld edge recognition

CREEP PROPERTIES OF HIGH SILICON ALLOY ZA27 PREPARED BY SPRAY DEPOSITION

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Acta Metallurgica Sinica(English Letters) 1996年第2期9卷 140-146页

作者： yang Liushuan LIU Yongchang yang Gencang ZHOU Yaohe(State Key Laboratory of Solidification Processing,Northwestern Polytechnic University,Xi’an,710072,China) Northeast Polytechnic Univ Xi'an China

The elevated temperature creep properties(90-150℃) of high silicon(～6wt%Si) alloy ZA27 prepared by spray deposition have been investigated by means of ball hardness testing *** results indicate that the creep properties of the material prepared by spray deposition are notably improved,compared to that of the conventional casting alloy *** creep activation energy of the spray deposited alloy ZA27 is 3.9-5.7 kJ/mol higher than that of the conventional casting alloy *** creep formulation in this experiment is also derived as follows:HB-2-HB0-2=K exp(- Q/3RT)(t1/3-t01/3)The reasons for the improvement of creep resistance are also discussed from a microstructural point of view.

关键词： spray deposition zinc-based alloy creep microstructure

First total synthesis of paecilodepsipeptide A

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Chinese Chemical Letters 2009年第5期20卷 527-530页

作者： Ming Jun yang Jing Wu Zhong Duo yang Ying Mei Zhang School of Life Sciences Lanzhou University Lanzhou 730000 China School of Life Science and Engineering Lanzhou University of Technology Lanzhou 730050 China

The first total synthesis of paecilodepsipeptide A is reported. A convergent, flexible strategy employing peptide chemistry and culminating in macrolactamisation is described. The previously reported structure of comp... 详细信息

关键词： Paecilodepsipeptide A Macrolactamisation Total synthesis

A facile synthesis of ω-aminoalkyl ammonium hydrogen phosphates

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Chinese Chemical Letters 2012年第8期23卷 923-926页

作者： Wei Bo Kong Xiao Yong Zhou yang yang Xing Yi Xie Department of Polymeric Biomaterials and Artificial Organs College of Polymer Science and EngineeringSichuan UniversityChengdu 610065China

A series of og-aminoalkyl ammonium hydrogen phosphates were synthesized through a simple and efficient three-step method. The starting materials, co-aminoalkyl alcohols （AC-n, with carbon number n = 3, 4, 5, 6）, were amino-protected with 9- fluorenylmethyl chloroformate （Fmoc-C1）, followed by phosphorylation with POCI3 and deprotection in piperidine/DME The structures of each intermediate and final product were confirmed by 1H NMR, FTIR and mass spectrum. The yield of each step was about 77-92%, with a total yield higher than 56%. This new method was superior in low-cost raw materials, mild reaction temperatures （0-25 ℃） and easy purification methods.

关键词： Amino alcohol Phosphorus oxychloride Synthesis Aminoalkyl ammonium hydrogen phosphate

An in vitro study on the efficacy of removing calcium hydroxide from curved root canal systems in root canal therapy

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International Journal of Oral Science 2017年第2期9卷 110-116页

作者： Ying Wang Li-yang Guo Hong-Zhi Fang Wen-Ling Zou Ying-Ming yang Yuan Gao Hui yang Tao Hu State Key Laboratory of Oral Disease National Clinical Research Center for Oral Diseases West China Hospital of Stomatology Sichuan University Chengdu China Department of Endodontics The Affiliated Stomatology Hospital School of Medicine Zhejiang University Hangzhou China Department of Stomatology The Third People's Hospital of Chengdu Chengdu China State Key Laboratory of Oral Disease National Clinical Research Center for Oral Diseases Department of Preventive Dentistry West China Hospital of Stomatology Siehuan University Chengdu China State Key Laboratory of Oral Disease National Clinical Research Center for Oral Diseases Department of General Dentistry West China Hospital of Stomatology Sichuan University Chengdu China

To compare the efficacy of various irrigants(citric acid, ethylenediaminetetraacetic acid(EDTA) and Na OCl) and techniques in removing Ca(OH)2in two types of curved root canal systems, simulated root canals with specific curvatures were used to investigate the effects of different irrigants and instruments on Ca(OH)2removal. The optimal methods were verified on extracted human teeth. Simulated root canals were assigned to one of two groups based on the irrigation solution: 10% citric acid or2.5% Na OCl. Each group was divided into four subgroups according to the technique used to remove Ca(OH)2. The percentage of Ca(OH)2removal in different sections of root canals was calculated. On the basis of the results obtained for the simulated canals, 10% citric acid and 17% EDTA were applied to remove Ca(OH)2from the extracted human teeth with curved root canal systems. The teeth were scanned by micro computed tomography to calculate the percentage of Ca(OH)2removal in the *** simulated root canals, we found that 10% citric acid removed more Ca(OH)2than 2.5% NaOCl in the 0–1 mm group from the apex level(Po0.05). Ultrasonic and Endo Activator activation significantly removed more Ca(OH)2than a size 30 K file in the apical third(Po0.05). However, there were no significant differences in any sections of the canals for 10% citric acid or 17%EDTA in removing Ca(OH)2in extracted human teeth. We concluded that it was effective to remove residual Ca(OH)2using the decalcifying solution with Endo Activator or Passive Ultrasonic Irrigation in a curved root canal system. A protocol for Ca(OH)2removal was provided based on the conclusions of this study and the methods recommended in previous studies.

关键词： calcium hydroxide curved root canal system irrigation removal

Effective Curvature Matrices and Mixed Moments of General Pulsed Paraxial Beams

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Chinese Physics Letters 1999年第12期16卷 894-895页

作者： yang Jun FAN Dian-yuan National Laboratory on High Power Laser and Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800

On the basis of the space-time Wigner distribution function, we use the least-squares fitting method to derive the relationship between effective wavefront curvature matrices and second-order mixed moments of quasimonochromatic and polychromatic pulsed paraxial beams. The expressions here are valid for both completely coherent and partially coherent light in the three-dimensional space. Finally, the fitting method is extended to the higher-order situation;from this, a novel technique for characterizing the beam phase from the moments and their derivatives is presented.

关键词： space. axial coherent

Using the Fractional Order Method to Generalize Strengthening Buffer Operator and Weakening Buffer Operator

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IEEE/CAA Journal of Automatica Sinica 2018年第6期5卷 1074-1078页

作者： Lifeng Wu Sifeng Liu Yingjie yang College of Economics and Management Hebei University of EngineeringHandan 056038China Centre for Computational Intelligence De Montfort UniversityLeicester LE1 9BHUK Institute for Grey System Studies Nanjing University of Aeronautics and AstronauticsNanjing 210016China

To reveal the relationship between a weakening buffer operator and strengthening buffer operator, the traditional integer order buffer operator is extended to one that is fractional order. Fractional order buffer operator not only can generalize the weakening buffer operator and the strengthening buffer operator, but also results in small adjustments of the buffer *** effectiveness of the grey model(GM(1,1)) with the fractional order buffer operator is validated by six cases.

关键词： Fractional order grey system theory strengthening buffer operator (SBO) weakening buffer operator (WBO)

Thermal Stress Analysis of Welded Joint in 1420 Al-Li Alloy Induced by Thermal Cycling

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Journal of Materials Science & Technology 2003年第z1期19卷 205-208页

作者： Hongbin GENG Song HE Dezhuang yang Space Materials and Environment Engineering Lab. Harbin Institute of Technology Harbin 150001 China Space Materials and Environment Engineering Lab. Harbin Institute of Technology Harbin 150001 China Space Materials and Environment Engineering Lab. Harbin Institute of Technology Harbin 150001 China

A model of double grains under plane stress state has been established. According to the double grain model, thermal stress induced by thermal cycling in welding fusion zone is numerically simulated by finite element method, and the microstructures before and after thermal cycling are observed. The effect of thermal stress on weld microstructure is discussed. Experimental and analysis results show that the difference between the coefficients of thermal expansion and elastic modulus for grains along different crystal directio n can produce alternate thermal misfit stress and strain near boundaries under thermal cycling. At the temperature of upper and lower limit, thermal stress nearby grain boundary reaches maxima. Thermal stress induced changes in microstructure, which expressed by the sending dislocations from boundaries to matrix, piling up against the boundaries and the increasing of dislocation density.

关键词： Thermal cycling, Al-Li alloy, Weld, Microstructure, Finite element method

Novel 18β-glycyrrhetinic acid amide derivatives show dual-acting capabilities for controlling plant bacterial diseases through ROS-mediated antibacterial efficiency and activating plant defense responses

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Journal of Integrative Agriculture 2023年第9期22卷 2759-2771页

作者： SONG Ying-lian LIU Hong-wu yang Yi-hong HE Jing-jing yang Bin-xin yang Lin-li ZHOU Xiang LIU Li-wei WANG Pei-yi yang Song National Key Laboratory of Green Pesticide/Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education/Center for R&D of Fine ChemicalsGuizhou UniversityGuiyang 550025P.R.China

Natural products have long been a crucial source of,or provided inspiration for new agrochemical *** occurring 18β-glycyrrhetinic acid shows broad-spectrum bioactivities and is a potential skeleton for novel drug *** extend the utility of 18β-glycyrrhetinic acid for agricultural uses,a series of novel 18β-glycyrrhetinic acid amide derivatives were prepared and evaluated for their antibacterial ***,compound 5k showed good antibacterial activity in vitro against Xanthomonas oryzae ***(Xoo,EC50=3.64 mg L–1),and excellent protective activity(54.68%)against Xoo in *** 5k induced excessive production and accumulation of reactive oxygen species in the tested pathogens,resulting in damaging the bacterial cell *** interestingly,compound 5k could increase the activities of plant defense enzymes including catalase,superoxide dismutase,peroxidase,and phenylalanine ammonia *** together,these enjoyable results suggested that designed compounds derived from 18β-glycyrrhetinic acid showed potential for controlling intractable plant bacterial diseases by disturbing the balance of the phytopathogen’s redox system and activating the plant defense system.

关键词： 18β-glycyrrhetinic acid antibacterial activities defense enzyme activity reactive oxygen species