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Science china chemistry 1990年第4期33卷 435-443页

作者：林仲翔 c.c.chang J.E.TROSKO Beijing Institute for cancer Research Beijing 108034 PRC Michigan State University MI USA

Gap junctional intercellular communication (GJIc) as measured by metabolic cooperation was examined in a rat glioma cell line P_(98)F_(47). x-ray induced mutants of P_(98)F_(47) cells were grown in 6-thioguanine selective medium (6TG medium) to separate 6TG-resistant HGPRT- mutant cells (6TG^r). By co-culturing 200 6TG^r cells with varied high densities of the wild type 6TG-sensitive cells (6TG^s), it was found that the recovery of 6TG^r cells depended on the density of 6TG^s cells. Higher densities of 6TG^s cells reduced the recovery of 6TG^r cells. These results demonstrate the ability of P_(98)F_(47) cells to perform metabolic cooperation which is indicative of GJIc. When metabolic cooperation was inhibited, increased recovery of 6TG^r cells was observed. Presented results also demonstrate metabolic cooperation between P_(98)F_(47) glioma cells and normal rat glial cells. Effect of tumor promoting chemicals on metabolic cooperation of P_(98)F_(47) cells was studied.~3H-uridine nucleot de echnique was used to confirm the above observations. The results suggest that these cells may provide the basis for an in uitro assay specially to study brain tumor promoters and neurotoxins.

关键词： GJIc glioma glial cell metabolic cooperation.

Transmission Electron Microscopy Study of the Infrared Brazed High-strength Titanium Alloy

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Journal of Materials Science & Technology 2010年第4期26卷 311-316页

作者： Z.Y. Wu R.K. Shiue c.S. chang Department of Materials Science and Engineering National Taiwan University Taipei 106 Taiwan China Engineered Materials Solutions 39 Perry Avenue MS 4-1 Attleboro MA 02703-2410 USA

The transmission electron microscopy was employed to investigate the microstructure of infrared brazed highstrength Ti alloy using the Ti-15cu-15Ni filler metal. coarse primary Ti2Ni and transformed β-Ti are observed in the 300 s brazed specimen. Blocky Ti2Ni and eutectoid Ti2cu intermetallics are disappeared from the joint with increasing the brazing time to 1800 s. Both acicular α-Ti and retained β-Ti dominate the entire brazed joint.

关键词： Infrared Brazing Ti Ti-cu-Ni filler Microstructure

South　china　Sea　Warm　Pool　in　Boreal　Spring

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Advances in Atmospheric Sciences 1997年第2期14卷 72-83页

作者： Peter c. chu c. P. chang Naval Postgraduate School Monterey USA

During the boreal spring of 1966, a warm-core eddy is identified in the upper South china Sea (ScS) west of the Philippines through an analysis of the U.S. Navy′s Master Oceanographic Observation Data Set. This eddy occurred before the development of the northern summer monsoon and disappeared afterward. We propose that this eddy is a result of the radiative warming during spring and the downwelling due to the anticyclonic forcing at the surface. Our hypothesis suggests an air-sea feedback scenario that may explain the development and withdrawal of the summer monsoon over the ScS. The development phase of the warm-core eddy in this hypothesis is tested by using the Princeton Ocean model.

关键词： Warm-core eddy Summer monsoon Downwelling South china Sea

An early report: a modified porphyrin-linked metronidazole targeting intracellular Porphyromonas gingivalis in cultured oral epithelial cells

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International Journal of Oral Science 2017年第3期9卷 167-173页

作者： Ping Ye Jiho chang Lin Feng Foo Benjamin c-M Yap Institute of Dental Research Centre for Oral Health Westmead Hospital Affiliation of Faculty of Dentistry the University of Sydney

Porphyromonas gingivalis （P. gingivalis） has a strong association with the pathogenesis of periodontal disease. Recurrence of periodontal disease following therapy is attributed to numerous factors, and of growing interest is the potential problem of intracellular bacteria that are able to persist and multiply within the host cell, thereby facilitating relapse of infection. The effect of antibiotic therapy in controlling P. gingivalis is questionable. Accordingly, while metronidazole is very effective against anaerobic extracellular P. gingivalis by disrupting the DNA of anaerobic microbial cells, this antibiotic does not effectively penetrate into mammalian cells to inhibit intracellular bacteria. Therefore in the present study, a modified porphyrin-linked metronidazole adducts, developed in our laboratory, was used to kill intracellular P. gingivalis. A series of experiments were performed, including cytotoxicity assays and cellular uptake of adducts by flow cytometry coupled with live cell imaging analysis, P. gingivalis invasion and elimination assays, and the analysis of colocalization of P. gingivalis and porphyrin-linked metronidazole by confocal laser scanning microscopy. Findings indicated that P. gingivalis and porphyrin-linked metronidazole were colocalized in the cytoplasm, and this compound was able to kill P. gingivalis intracellular with a sufficient culture time. This is a novel antimicrobial approach in the elimination of P. gingivalis from the oral cavity.

关键词： porphyrin-linked metronidazole Porphyromonas gingivalis periodontitis oral epithelial cells

Effect of Laser Welding on Properties of Dissimilar Joint of Al-Mg-Si and Al-Mn Aluminum Alloys

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Journal of Materials Science & Technology 2010年第3期26卷 276-282页

作者： c.c.chang c.P.chou S.N.Hsu G.Y.Hsiung J.R.chen Department of Mechanical Engineering National Chiao-Tung University National Synchrotron Radiation Research center Department of Biomedical Engineering and Environmental Sciences National Tsing-Hua University

This study discusses the welding properties for the components of an aluminum-alloy ultra-high vacuum chamber and beam position monitor （BPM）.The welding parameters include the modes of laser output （pulsed wave and continuous wave）,welding speed,shield gas flow,welding bead structure,and focusing *** results showed that the welding defect rate of the pulsed wave type was larger than that of the continuous wave *** crack in the welding bead reduced with decreasing welding *** fusion penetration of the welding bead was higher when the focusing distance was long enough to deepen into the welding *** morphology during the experimental process revealed the proper flow of shield *** adaptability design of the welding bead structure in the preceding processes had more effect on overall welding structure and morphology.

关键词： Laser welding Aluminum alloy Ultra-high vacuum Beam position monitor (BPM)

Influence of austenization temperature on the erosion behavior of austempered ductile irons

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Journal of University of Science and Technology Beijing 2008年第1期15卷 29-33页

作者： L.c. chang L c. Hsui L.H. chen S.T. Lui Department of Mechanical Engineering Technology and Science Institute of Northern Taiwan Taipei 112 China Talpei Department of Materials Science and Engineering Cheng-Kung University Talnan 800 China Taipei

The erosion behavior of austempered ductile irons austenized at different temperatures was studied. The results indicate that the erosion rate well correlates with the mechanical properties. At high impact angles, increasing ductility and mechanical energy density results in decreasing erosion rate, whereas increasing hardness reduces the erosion rate at low impact angles. 2008 University of Science and Technology Beijing. All rights reserved.

关键词： austempered ductile iron erosion mechanical properties austenization

Progress in sonochemical fabrication of nanostructured photocatalysts

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Rare Metals 2016年第3期35卷 211-222页

作者： chang-Lin Yu Jimmy c.Yu Hong-Bo He Wan-Qin Zhou School of Metallurgy and chemical Engineering Jiangxi University of Science and Technology Department of chemistry The Chinese University of Hong Kong State Key Laboratory of Photocatalysis on Energy and Environment Fuzhou University

In recent years,nanostructured photocatalysts have become the research focus due to their immense potential application in environmental purification and energy *** photocatalytic performance of photocatalysts is closely related to their synthesis ***-intensity ultrasound irradiation could provide a unique tool for fabrication of photocatalysts with novel *** induces acoustic cavitation which generates unique physicochemical conditions,e.g.,hot spot（5000℃）,high pressure of 100 MPa,fast rate of heat conduction（〉〉1×10^10℃·s^-1）.These unique physicochemical conditions allow for the synthesis of various nanostructured *** review summarized the recent development in fabrication of photocatalysts with special nanostructures and their *** typical sonochemical reactors and parameters in sonochemical synthesis are introduced and *** prepared structures including nano-/microspheres,one-dimensional（1D） nanorods,two-dimensional（2D） nanosheets（nanoflakes,nanosquares）,noble metal nanoparticle（NP）-deposited and element-doped photocatalysts are described and *** is believed that sonication is a green methodology,and it holds greatpotential in the near future for nanostructured photocatalyst fabrication.

关键词： Sonochemical reactor Photocatalysts Nano-/microsphere One/two-dimensional nanostructure Ultrasonic deposition and doping Pollutant degradation

THEORETIcAL PREDIcTION OF THE KINETIcS cURVES OFPEARLITIc TRANSFORMATION IN HYPO-PROEUTEcTOID STRUcTURAL STEELS

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Acta Metallurgica Sinica(English Letters) 1998年第3期11卷 215-224页

作者： Z.G.Li H.B.chang T.Y.Hsu Z.Y.xu x.Y.Ruan Shanghai Jiaotong Univ Shanghai China

Supposing carbon contents of ferrite phases in pearlite precipitating from austenite in multicomponent steel at temperature T and in Fe-c ystem at T' are the same the pearlite formation temperature diference, can be calculated from the Fex phase diagrams and the equilibrium temperature Al. Using Tp and Fe-c binary thermodynamic model, the driving forces for phase transformation from austenite to pearlite in multicomponent steels have been successfully calculated. Through the combination of simplified Zener and Hillert's model for pearlite growth with Johnson-Mehl equation, using data from known TTT diagrams, the interfacial energy parameter and activation energy for pearlite formation can be determined and expressed as functions of chemical composition in steels by regression analysis. The calculated starting curves of pearlitic transformation in some commercial steels agree well with the experimental data.

关键词： pearlite formation temperature difference interfacial energy parameter activation enerpy for pearlite transformation,Johnson-Mehl equation

Testing the potential mechanisms for the maintenance of a genetic color polymorphism in bluefin killifish populations

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current Zoology 2018年第6期64卷 733-743页

作者： Ashley M.JOHNSON chia-Hao chang Rebecca c.FULLER Department of Animal Biology School of Integrative BiologyUniversity of Illinois at Urbana-ChampaignChampaignIL 61820USA

The maintenance of genetic variation in the face of natural selection is a long-standing question in evolutionary *** the bluefin killifish Lucania goodei,male coloration is *** can produce either red or yellow coloration in their anal fins,and both color morphs are present in all *** 2 morphs are heritable and how they are maintained in nature is ***, we tested 2 mechanisms for the maintenance of the red/yellow color *** frequency-dependent mating success predicts that rare males have a mating advantage over common males. Spatial variation in fitness predicts that different color morphs have an advantage in different microhabitat *** a breeding experiment,we tested these hypotheses by creating populations with different ratios of red to yellow males (5 red:1 yellow;1 red:5 yellow)and determining male mating success on shallow and deep spawning *** found no evidence of negative frequency-dependent mating *** morphs tended to have higher mating success, and this was particularly so on shallow spawning ***,on deep substrates,red males enjoyed higher mating success than yellow males,particularly so when red males were rare. However,yellow males did not have an advantage at either depth nor when *** suggest that preference for red males is expressed in deeper water,possibly due to alterations in the lighting ***,male pigment levels were correlated with one another and predicted male mating ***,pigmentation plays an important role in male mating success.

关键词： carotenoid color polymorphism environmental heterogeneity melanin negative frequency dependence pterin

THEORETIcAL PREDIcTION OF PROEUTEcTOID FERRITIcTRANSFORMATION IN HYPO-PROEUTEcTOID STRUcTRAL STEELS

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Acta Metallurgica Sinica(English Letters) 1998年第3期11卷 207-214页

作者： H.B.chang Z.G.Li T.Y.Hsu Z.Y.xu x.Y.Ruan Shanghai Technical coll of Metallurgy Shanghai China

Proeutectoid ferrite with carbon content xo precipitating from austenite in a multicomponent steel at temperature T is supposed to be equivalent to proeutectoid ferrite with the same carbon content precipitating from austenite in Fe-c binary system at temperature T'.is described as the temperature difference of proeutectiod ferrite formation, and can be calculated from the Fe-x diagrams and the equilibrium temperature A3. By introducing Tf and basing on the thermodynamic model for Fe-c binary alloy, the driving force for phase transformation from austenite to proeutectoid ferrite in multicomponent steels has been successfully calculated. Through the Johnson-Mehl equation and using the data hem known TTT diagrams, the relationship between the chemical composition and the intedecial edenly packeter as well as activation energy for proeutectoid ferrite formation can be calculated. The starting curves of proeutectoid ferritic transformation calculated in this way in some hypo-proeutectoid structural steels agree well with the erperimental data.

关键词： proeutectoid ferrite formation temperature difference interfacial enerpy parameters activation energy for diffusion Johnson-Mehl equation