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Time Dependant Weld Shape in Ar-O_2 Shielded Stationary GTA Welding

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journal of Materials Science & Technology 2007年第5期23卷 650-654页

作者： Shanping l.u Dianzhong lI Hidetoshi Fujii Kiyoshi Nogi Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 Chian joining and Welding Research Institute Osaka University Osaka567-0047 Japan

The stationary gas tungsten arc welding （GTA） is carried out on SuS304 stainless steel.under Ar-0.1%O2 and Ar-0.3%O2 mixed shielding to observe the evolution of the molten pool and investigate the role of Marangoni convection on the weld shape. After welding, the oxygen content in the weld metal was measured by using an oxygen/nitrogen analyzer. Small addition of oxygen to the argon based shielding gas can effectively adjust the weld pool oxygen content. Oxygen plays an important role as an surface active element in determining the pattern of Marangoni convection in the stainless steel weld pool. When the weld metal oxygen content is over the critical value, 0.01 wt pct, corresponding to the Ar-0.3%O2 mixed shielding gas, the Marangoni convection changes from outward to inward direction and the weld shape dramatically changes from wide shallow shape to narrow deep shape.

关键词： Marangoni convection Oxygen Weld shape

Chaos,Transport and Mesh Convergence for Fluid Mixing

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Acta Mathematicae Applicatae Sinica 2008年第3期24卷 355-368页

作者： H. lim Y. Yu j. Glimm x.l. li D.H. Sharp Department of Applied Mathematics and Statistics Stony Brook University Stony Brook NY 11794-3600 USA Computational Science Center Brookhaven National Laboratory Upton N~ 11793-6000 USA los Alamos National laboratory Los Alamos NM USA

Chaotic mixing of distinct fluids produces a convoluted structure to the interface separating these fluids. For miscible fluids （as considered here）, this interface is defined as a 50% mass concentration isosurface. For shock wave induced （Richtmyer-Meshkov） instabilities, we find the interface to be increasingly complex as the computational mesh is refined. This interfacial chaos is cut off by viscosity, or by the computational mesh if the Kolmogorov scale is small relative to the mesh. In a regime of converged interface statistics, we then examine mixing, i.e. concentration statistics, regularized by mass diffusion. For Schmidt numbers significantly larger than unity, typical of a liquid or dense plasma, additional mesh refinement is normally needed to overcome numerical mass diffusion and to achieve a converged solution of the mixing problem. However, with the benefit of front tracking and with an algorithm that allows limited interface diffusion, we can assure convergence uniformly in the Schmidt number. We show that different solutions result from variation of the Schmidt number. We propose subgrid viscosity and mass diffusion parameterizations which might allow converged solutions at realistic grid levels.

关键词： Schmidt number mass diffusion turbulence multiphase flow

In situ sol-gel synthesis of hyaluronan derivatives bio-nanocomposite hydrogels

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Regenerative Biomaterials 2019年第5期6卷 249-258页

作者： u.D’Amora A.Ronca M.G.Raucci S.M.Dozio H.lin Y.Fan x.Zhang l.Ambrosio Institute of Polymers Composites and BiomaterialsNational Research CouncilNaplesItaly Institute of Science and Technology for Ceramics National Research CouncilFaenzaItaly School of Advanced Study“G.D’Annunzio” University of Chieti-PescaraChieti Italy National Engineering Research Center for Biomaterials Sichuan UniversityChengduChina

The main driving idea of the present study was the comparison between two different chemical modifications of hyaluronic acid(HA)followed by the development of nanocomposite hydrogels directly in situ by biomineralization of photocrosslinkable HA polymers through sol-gel *** this way,it has been possible to overcome some limitations due to classical approaches based on the physical blending of inorganic fillers into polymer *** this aim,methacrylated and maleated HA,synthesized with similar degree of substitution(DS)were compared in terms of mechanical and physico-chemical *** success of in situ biomineralization was highlighted by reflect Fourier transform infrared spectroscopy and thermogravimetric ***,mechanical characterization demonstrated the reinforcing effect of inorganic fillers evidencing a strong correlation with *** swelling behavior resulted to be correlated with filler ***,the cytotoxicity tests revealed the absence of toxic components and an increase of cell proliferation over cul.ure time was observed,highlighting these bio-nanocomposite hyaluronan derivatives as biocompatible hydrogel with tunable properties.

关键词： hyaluronic acid derivatives photocrosslinking sol-gel nanocomposites

Multi-Compartment SCFA Quantification in Human

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American journal of Analytical Chemistry 2024年第6期15卷 177-200页

作者： jérémy Monteiro Antoine lefèvre Diane Dufour-Rainfray Adeline Oury Gabrielle Chicheri l.urent Galineau Hélène Blasco lydie Nadal-Desbarats Patrick Emond Imaging Brain & Neuropsychiatry iBraiN u1253 Universit de Tours INSERM MetaboHub Tours Tours France CHRu de Tours Service de Mdecine Nuclaire in Vitro Tours France Service de Biochimie et Biologie Mol.ulaire CHRU Tours France

Short-chain fatty acids (SCFA) play an important role in human biochemistry. They originate primarily from the digestive system through carbohydrates microbial fermentation. Most SCFA produced in the colon are absorbed by the intestinal wall and enter the bloodstream to be distributed throughout the body for multiple purposes. At the intestinal level, SCFA play a role in controlling fat storage and fatty acid metabolism. The effects of these beneficial compounds therefore concern overall health. They facilitate energy expenditure and are valuable allies in the fight against obesity and diabetes. SCFA are also involved in the regulation of the levels of several neurotransmitters such as GABA (γ-aminobutyric acid), glutamate, serotonin, dopamine, and norepinephrine. Their role is also highlighted in many inflammatory and neurodegenerative diseases such as Alzheimer’s disease (AD) or Parkinson’s disease (PD). To have a realistic picture of the distribution of SCFA in different biological compartments of the human body, we propose to study SCFA simultaneously in five human biological samples: feces, saliva, serum, cerebrospinal fluid (CSF), and urine, as well as in Dried Blood Spot (DBS). To evaluate their concentration and repeatability, we used 10 aliquots from pooled samples, analyzed by 3-nitrophenylhydrazine (3-NPH) derivation and liquid chromatography coupled with high sensitivity mass spectrometry (lC-QqQ-MS). We also evaluated the SCFA assay on Dried Blood Spot (DBS). In this work, we adapted the pre-analytical parts for each sample to be able to use a common calibration curve, thus facilitating multi-assay quantification studies and so being less time-consuming. Moreover, we proposed new daughter ions from the same neutral loss (43 Da) to quantify SCFAs, thus improving the sensitivity. In conclusion, our methodology, based on a unique calibration curve for all samples for each SCFA, is well-suited to quantified them in a clinical context.

关键词： lC-MS 3-Nitrophenylhydrazine Short-Chain Fatty Acids Human Biological Samples Quantification

All-optical image denoising using a diffractive visual processor

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light(Science & Applications) 2024年第3期13卷 429-445页

作者： Çağatay Işıl Tianyi Gan Fazil Onuralp Ardic Koray Mentesoglu jagrit Digani Huseyin Karaca Hanlong Chen jingxi li Deniz Mengu Mona jarrahi Kaan Akşit Aydogan Ozcan Electrical and Computer Engineering Department University of CaliforniaLos AngelesCA 90095USA Bioengineering Department University of CaliforniaLos AngelesCA 90095USA California NanoSystems Institute(CNSI) University of CaliforniaLos AngelesCA 90095USA university College london Department of Computer ScienceLondonUnited Kingdom

Image denoising,one of the essential inverse problems,targets to remove noise/artifacts from input *** general,digital image denoising algorithms,executed on computers,present latency due to several iterations implemented in,e.g.,graphics processing units(GPus).While deep learning-enabled methods can operate non-iteratively,they also introduce latency and impose a significant computational burden,leading to increased power ***,we introduce an analog diffractive image denoiser to all-optically and non-iteratively clean various forms of noise and artifacts from input images–implemented at the speed of light propagation within a thin diffractive visual processor that axially spanslength of *** all-optical image denoiser comprises passive transmissive layers optimized using deep learning to physically scatter the optical modes that represent various noise features,causing them to miss the output image Field-of-View(FoV)while retaining the object features of *** results show that these diffractive denoisers can efficiently remove salt and pepper noise and image rendering-related spatial artifacts from input phase or intensity images while achieving an output power efficiency of~30–40%.We experimentally demonstrated the effectiveness of this analog denoiser architecture using a 3D-printed diffractive visual processor operating at the terahertz *** to their speed,power-efficiency,and minimal computational overhead,all-optical diffractive denoisers can be transformative for various image display and projection systems,including,e.g.,holographic displays.

关键词： remove rendering holographic

A comparison of gene expression in mouse liver and kidney in obstructive cholestasis utilizing high-density oligonucleotide microarray technology

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World journal of Gastroenterology 2006年第16期12卷 2536-2548页

作者： Gerald u Denk Shi-Ying Cai Wen-Sheng Chen Aiping lin Carol j Soroka james l Boyer liver Center Yale University School of Medicine New Haven Connecticut United States W. M. Keck Biotechnology Resource laboratory Yale University School of Medicine New Haven ConnecticutUnited States Department of Medicine II-GroBhadem LudwigMaximilians University Miinchen Germany Department of Gastroenterology Southwest Hospital Third Military Medical University Chongqing 400038China

AIM： To assess the effects of obstructive cholestasis on a wider range of gene expression using microarray technology. METHODS： Male C57BI_/6j mice underwent common bile duct ligation （BDl） and were matched with pairfed sham-operated controls. After 7 d, the animals were sacrificed and total RNA was isolated from livers and kidneys. Equal amounts of RNA from each tissue were pooled for each group and hybridized to Affymetrix GeneChip^MG-u74Av2 containing a total of 12488 probe sets. Data analysis was performed using GeneSpring 6.0 software. Northern analysis and immunofluorescence were used for validation. RESulTS： In sham-operated and BDl mice, 44 and 50% of 12488 genes were expressed in livers, whereas 49 and 51% were expressed in kidneys, respectively. Seven days after BDl, 265 liver and 112 kidney genes with GeneOntology annotation were up-regulated and 113 liver and 36 kidney genes were down-regulated in comparison with sham-operated controls. Many genes were commonly regulated in both tissues and metabolism-related genes represented the largest functional group. CONCluSION： Following BDl, microarray analysis reveals a broad range of gene alterations in both liver and kidney.

关键词： Bile duct ligation Cholestasis Kidney liver Microarray

煤炭地下气化渗透反应墙构建材料的吸附和渗流特性研究

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矿业科学学报 2024年第2期9卷 167-177页

作者：王凡徐冰谌伦建邢宝林苏发强河南省煤炭绿色转化重点实验室河南理工大学化学化工学院河南焦作454003 煤炭安全生产与清洁高效利用省部共建协同创新中心河南焦作454003 河南理工大学能源科学与工程学院河南焦作454003

煤炭地下气化(uCG)带来的地下水污染风险是限制其推广发展的主要问题之一。渗透反应墙(PRB)修复技术是地下水原位修复的主要研究热点,而PRB材料特性是影响其正常运行的关键。本文首先探究了砂、有机膨润土、活性炭对uCG特征有机污染物... 详细信息

煤炭地下气化(uCG)带来的地下水污染风险是限制其推广发展的主要问题之一。渗透反应墙(PRB)修复技术是地下水原位修复的主要研究热点,而PRB材料特性是影响其正常运行的关键。本文首先探究了砂、有机膨润土、活性炭对uCG特征有机污染物苯酚的吸附特性,在此基础上,采用自建的渗流实验系统研究了砂、有机膨润土、活性炭及其混合物的吸附和渗透特性对净化污染水的综合影响效果。结果表明:(1)有机膨润土对溶液中苯酚的吸附速率较快,可在10 min之内达到吸附平衡,但吸附容量较小(1.98 mg/g);活性炭对溶液中苯酚的吸附速率较慢,但吸附容量较大(2.22 mg/g)。(2)有机膨润土对苯酚的等温吸附可用Freundlich模型描述,模型参数k_(F)=0.040,n=1.207;活性炭对苯酚的等温吸附可用langmuir模型描述,模型参数S_(max)=2.44 mg/g,k_(l)=0.125 l/mg。(3)砂和活性炭的渗透系数分别为1.006×10^(-3) m/s和4.761×10^(-2) m/s,砂与活性炭或有机膨润土混合可有效调节混合材料的渗透性,当砂与有机膨润土质量比由1∶1增大到3∶1时,其混合材料的渗透系数由2.624×10^(-6)增大至3.468×10^(-5) m/s;而砂与活性炭质量比由1∶1增大到3∶1时,其混合材料的渗透系数由1.379×10^(-3)减小至1.301×10^(-4) m/s。

关键词：煤炭地下气化污染地下水渗透反应墙渗流等温吸附

AlGORITHM AND IMPlEMENTATION OF AuTO-SEARCHING WElD lINE FOR WElDING MOBIlE ROBOT

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Chinese journal of Mechanical Engineering 2006年第2期19卷 176-180页

作者： ZHANG Ke lü xueqin　 Wu Yixiong l.u Songnian Institute of Welding Engineering Shanghai Jiaotong UniversityShanghai 200030 China

An algorithm of auto-searching weld line for welding mobile robot is presented. Auto-searching weld line is that the robot can automatically recognize a weld groove according to the characteristics of the weld groove before welding, and then adjust itself posture to the desired status preparing for welding, namely, it is a process that the robot autonomously aligns itself to the center of welding seam. Firstly, the configuration of welding mobile robot with the function of auto-searching weld line is introduced, then the algorithm and implementation of auto-searching weld line are presented on the basis of kinematics model of the robot, at last trajectory planning among auto-searching weld line is investigated in detail. The experiment result shows that the developed welding mobile robot can successfully implement the task of auto-searching weld line before welding, tracking error precision can be controlled to approximate ±1.5 mm, and satisfy the requirement of practical welding project.

关键词： Welding mobile robot Auto-searching weld line Trajectory planning

Application of Reactive Ion Etching to the Fabrication of Microstructure on Mo/Si Multilayer

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Chinese Physics letters 1999年第9期16卷 665-666页

作者： lE Zi-chun l.Dreeskornfeld S.Rahn R.Segler u.Kleineberg u.Heinzmann Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012 Fakultät für Physik Universität BielefeldUniversitatsstraβe 25D-33615 BielefeldGermany

Mo/Si muitilayer mirrors(30 periods,doublelayer thickness 7nm)with the AZ-PF514 resist pattern whose smallest lines and spaces structure was 0.5pm were etched by reactive ion etching(RIE)in a fluorinated *** etch rate,selectivity and etch profile were investigated as a function of the gas mixture,pressure,and plasma rf *** groove depth and the etch proHle were investigated by an atomic force microscope before RIE,after RIE and after resist removal.

关键词： Mo/Si smallest selectivity