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T6态A356/SiC与Semi-metallic Pad的干滑动摩擦磨损特性

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稀有金属材料与工程 2008年第12期37卷 2147-2151页

作者：金云学 jung-moo Lee Suk-Bong Kang 江苏科技大学先进焊接技术省级重点实验室江苏镇江212003 Korea Institute of machinery and materials Changwon 641-010Korea

选用A356/SiC复合材料与Semi-metallic pad材料进行干滑动摩擦磨损试验,并采用SEm、XRD、EDS等手段分析了复合材料的摩擦磨损特点及磨损机制。铝基复合材料与该pad间表现出非常出色的耐摩擦磨损特性,在1m/s的低滑动速度下,即使载荷增加... 详细信息

选用A356/SiC复合材料与Semi-metallic pad材料进行干滑动摩擦磨损试验,并采用SEm、XRD、EDS等手段分析了复合材料的摩擦磨损特点及磨损机制。铝基复合材料与该pad间表现出非常出色的耐摩擦磨损特性,在1m/s的低滑动速度下,即使载荷增加到700n也几乎不发生磨损;载荷不大于500n时,磨损率与滑动速度无关,保持非常小的范围。只有在高载荷、高滑动速度下才会有较为明显的磨损。摩擦系数则随载荷增大产生无规则变化,而随滑动速度的增加而减少,但变化幅度在0.1之内。复合材料耐磨特性好的主要原因是,磨损过程中磨损面上迅速形成以氧化物和石墨为主的润滑膜,减少磨损。高载荷、高滑动速度下磨损的主要特点为,复合材料表层形成塑性流动层,大的塑性流动变形使得较软的铝合金基体沿磨损方向以片状形式挤出,形成特殊的磨屑。而不易变形的SiC颗粒则留在磨损面上形成SiC聚集区,该区域又能在一定程度上减少进一步的磨损。

关键词： SiC 铝合金滑动磨损机制摩擦磨损

Anoxic gas recirculation system for fouling control in anoxic membrane reactor

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Journal of Environm.ntal Sciences 2014年第6期26卷 1289-1293页

作者： Hansaem Lee Daeju Lee Seongwan Hong Geum Hee Yun Sungpyo Kim jung Ki Hwang Woojae Lee Zuwhan Yun Research Institute for Environm.ntal Technology and Sustainable Developm.nt Korea UniversitySeoul 136-713 Korea Departm.nt of Environm.ntal Engineering Korea UniversitySejong 339-700 Korea Dongbu Corporation Seoul 135-523 Korea

Anoxic gas recirculation system was applied to control the membrane fouling in pilot-scale 4- stage anoxic membrane bioreactor （mBR）. In the anaerobic-anoxic-anoxic-aerobic flow scheme, hydrophilic polytetrafluoroethylene （PTFE） membrane （0.2 μm, 7.2 m2/module） was submerged in the second anoxic zone. During 8 m.nths operation, the average flux of the membrane was 21.3 L/（***）. Chemical cleaning of the membrane was conducted only once with sodium hydroxide and sodium hypochlorite. Dissolved oxygen （DO） concentration in the second anoxic zone was maintained with an average of 0.19 ± 0.05 mg/L. Gas chromatography analysis showed that the headspace gas in the second anoxic reactor was mainly consisted of n2 （93.0% ± 2.5%）, O2 （3.8% ± 0.6%）, and CO2 （3.0% ± 0.5%）, where the saturation DO concentration in liquid phase was 1.57 mg/L. Atmospheric 02 content （20.5% ± 0.8%） was significantly reduced in the anoxic gas. The average pH in the reactor was 7.2 ± 0.4. As a result, the recirculation of the anoxic gas was successfully applied to control the membrane fouling in the anoxic mBR.

关键词： anoxic gas recirculation system anoxic membrane bioreactor fouling

Analyses of oligodontia phenotypes and genetic etiologies

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International Journal of Oral Science 2021年第3期13卷 323-332页

作者： m.ngqi Zhou Hong Zhang Heather Camhi Figen Seym.n m.ne Koruyucu Yelda Kasimoglu jung-wook Kim Hera Kim-Berm.n ninna m.R.Yuson Paul J.Benke Yiqun Wu Feng Wang Yaqin Zhu James P.Simmer Jan C-C.Hu Dental Research Laboratory University of Michigan School of DentistryAnn ArborMIUSA Departm.nt of Second Dental Center Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghaiChina Departm.nt of General Dentistry Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghaiChina Orthodontic and Pediatric Dentistry University of Michigan School of Dentistry1011N.University AveAnn ArborMIUSA mott Children’s Health Center 806 Tuuri Place FlintMIUSA Departm.nt of Pedodontics Faculty of DentistryIstanbul UniversityIstanbulTurkey Departm.nt of molecular Genetics&Dental Research Institute School of Dentistry Seoul National UniversitySeoulKorea Departm.nt of Pediatric Dentistry&Dental Research Institute School of Dentistry Seoul National UniversitySeoulKorea Departm.nt of Paediatric Dentistry Women’s and Children’s HospitalNorth AdelaideSAAustralia Departm.nt of medical Genetics Joe DiMaggio Children’s HospitalHollywoodFLUSA Departm.nt of Oral Implantology Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghaiChina

Oligodontia is the congenital absence of six or more teeth and comprises the more severe forms of tooth *** genes have been implicated in the etiology of tooth agenesis,which is highly variable in its clinical *** purpose of this study was to identify associations between genetic mutations and clinical features of oligodontia *** online systematic search of papers published from January 1992 to June 2021 identified 381 oligodontia cases meeting the eligibility criteria of causative gene mutation,phenotype description,and radiographic ***,ten families with oligodontia were recruited and their genetic etiologies were determ.ned by whole-exome sequence *** identified a novel mutation in WnT10A(c.99_105dup)and eight previously reported mutations in WnT10A(c.433 G>A;c.682 T>A;c.318 C>G;c.511.C>T;c.321 C>A),EDAR(c.581 C>T),and LRP6(c.1003 C>T,c.2747 G>T).Collectively,20 different causative genes were implicated am.ng those 393 cases with *** each causative gene,the mean number of missing teeth per case and the frequency of teeth missing at each position were ***–phenotype correlation analysis indicated that molars agenesis is more likely linked to PAX9 mutations,m.ndibular first premolar agenesis is least associated with PAX9 mutations.

关键词： clinical congenital likely

Soil texture affects the conversion factor of electrical conductivity from 1:5 soil-water to saturated paste extracts

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Pedosphere 2022年第6期32卷 905-915页

作者： Bo-Seong SEO Young-Jae JEOnG nu-Ri BAEK Hyun-Jin PARK Hye In YAnG Se-In PARK Woo-jung CHOI Departm.nt of Rural and Bio-systems Engineering(BK21) Chonnam National UniversityGwangju 61186(Republic of Korea) Departm.nt of Renewable Resources University of AlbertaEdmontonAlberta T6G 2E3(Canada) max Planck Institute for Biogeochemistry Jena 07745(Germany) national Institute of Environm.ntal Research Incheon 22689(Republic of Korea) AgriBio Institute of Climate Change m.nagem.nt Chonnam National UniversityGwangju 61186(Republic of Korea)

Electrical conductivity(EC)of soil-water extracts is comm.nly used to assess soil ***,its conversion to the EC of saturated soil paste extracts(ECe),the standard measure of soil salinity,is currently required for practical *** m.ny regression models can be used to obtain ECe from the EC of soil-water extracts,the application of a site-specific model to different sites is not straightforward due to confounding soil factors such as soil *** study was conducted to develop a universal regression model to estimate a conversion factor(CF)for predicting EC_(e) from EC of soil-water extracts at a 1:5 ratio(EC_(1:5)),by employing a site-specific soil texture(i.e.,sand content).A regression model,CF=8.9105e^(0.0106sand)/1.2984(r^(2)=0.97,Pn the results of coastal saline soil surveys(n=173)and laboratory experim.nts using artificial saline soils with different textures(n=6,sand content=10%-65%)and salinity levels(n=7,salinity=1-24 dS m^(-1)).model perform.nce was validated using an independent dataset and dem.nstrated that EC_(e) prediction using the developed model is more suitable for highly saline soils than for low saline *** feasibility of the regression model should be tested at other *** soil factors affecting EC conversion factor also need to be explored to revise and improve the model through further studies.

关键词： coastal saline soils electrical conductivity prediction reclaimed tideland regression model sand content saturation percentage soil salinity

Comparison of the meibomian gland dysfunction in patients with chronic ocular graft-versus-host disease and Sjogren's syndrome

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International Journal of Ophthalmology(English edition) 2019年第3期12卷 393-400页

作者： Won Choi Jun Young Ha Ying Li jung Han Choi Yong Sok Ji Kyung Chul Yoon Departm.nt of Ophthalmology and Research Institute of medical Sciences Chonnam National University Medical School and Hospital

AIm: To investigate the abnormalities in the meibomian gland in patients with dry eye disease(DED) associated with chronic ocular graft-versus-host disease(coGVHD) in comparison with Sj?gren's syndrome(SS), a major form of aqueous deficient DED and meibomian gland dysfunction(mGD), a comm.n cause of evaporative ***: A total 135 eyes of 135 subjects included in this study: patients with DED associated with coGVHD(n=30), patients with SS(n=35), patients with mGD(n=35), and normal controls(n=35). All participants completed the Ocular Surface Disease Index(OSDI) questionnaire, ocular surface exam.nation [Schirmer test, tear film breakup time(TFBUT), and ocular surface staining], and meibomian gland assessm.nt [meiboscore(gland dropout detected on meibography using infrared camera of the Keratograph 5 m), meibum expressibility score(mES), meibum quality score(mQS), lid margin abnormality]. In addition, correlations of meibomian gland characteristics with ocular surface parameters as well as disease severity score were investigated in coGVHD ***: The coGVHD group showed significantly higher meiboscore, mES, and mQS than the other 3 groups(all Pn the coGVHD group, parameters of meibomian gland showed a significant correlation each other and those of ocular surface. The correlation between meibomian gland parameters and severity score of co GVHD was also established(meiboscore, r=0.62; mES, r=0.47; mQS, r=0.47; lid margin abnormality score, r=0.55; all PnCLUSIOn: Patients with DED associated with co GVHD show poorer gland morphology and worse glandfunction than other types of DED. In addition, meibomian gland damage is not only associated with ocular surface damage but also disease severity of coGVHD.

关键词： chronic ocular graft-versus-host disease Sjogren's syndrome dry eye disease meibomian gland dysfunction meibography

铸态铝基复合材料与半金属衬片摩擦副的干滑动摩擦磨损特性研究

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摩擦学学报 2008年第3期28卷 266-271页

作者：金云学 jung-moo Lee Suk-Bong Kang 江苏科技大学先进焊接技术省级重点实验室江苏镇江212003 Advanced materials Division Korea Institute of Machinery and Materials Changwon 641-010 Korea

采用铸态A356/SiC复合材料与高速列车制动盘偶件半金属衬片材料摩擦副进行干摩擦磨损试验,并用扫描电子显微镜、X射线衍射仪和能谱仪等手段分析了复合材料的磨损机制.结果表明:复合材料表现出良好的磨损特性,在滑动速度3.0m/s以下,载荷... 详细信息

采用铸态A356/SiC复合材料与高速列车制动盘偶件半金属衬片材料摩擦副进行干摩擦磨损试验,并用扫描电子显微镜、X射线衍射仪和能谱仪等手段分析了复合材料的磨损机制.结果表明:复合材料表现出良好的磨损特性,在滑动速度3.0m/s以下,载荷达到600n(12mPa)时的磨损量仍很小;复合材料的磨损率随pv(压力与速度的积)值的增加而增大,摩擦系数则随pv值增加而小幅度减少;磨损过程中磨损表面很快形成以氧化物和以石墨为主的润滑膜,起到了减摩和耐磨作用.在pv值较低时复合材料的磨损机制为轻微的氧化磨损机制,随着pv值增加出现剥层磨损,在复合材料与半金属衬片间的接触表面,由于塑性流动挤出片状磨屑而使磨损量降低.

关键词：复合材料半金属衬片干摩擦摩擦磨损性能

Reliability of fourier transform infrared spectroscopy in the characterization of hum.n skin

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Advances in Biological Chemistry 2011年第2期1卷 24-28页

作者： maria O Longas Kenya Cheairs michelle m Puchalski jung I Park Departm.nt of Chemistry and Physics Purdue University Calumet 2200 169th Street Hammond IN 46323

Fourier transform infrared (FT-IR) spectroscopy, an organic molecule characterizing tool, is used here to differentiate young (36 ? 2.87 years) and aged (78 ? 1.25 years) skins, based on glycosam.noglycan (GAG) and protein functional groups. Female breast mas-tectomy-skin, FT-IR spectroscopy revealed intensity differences that were quantified on GAG and protein standard curves, and assigned to the corresponding functional groups. Band intensity reductions at 78- years include: 34.37% (w/w) ?1259 - 1223 cm–1, sulfate (SO42–)/sulfonate (SO3–) S=O/phosphate (PO42?) P=O stretch?;32.00% (w/w) (1383-1262 cm-1, GAG- methyl C-H/C-C-H);and 35.60% (w/w) ?1738 - 1646 cm–1, C=O stretch: n-acetylated GAG’s, Amide I, and others?. Intensity increm.nts at 78-years are 63.32% (w/w) (1636 - 1523 cm–1, Phe/Trp/Tyr-C=C, Amide II);27.02% (w/w) [1511 - 1457 cm–1, protein ?(CH2)/ ?(CH3) stretch];and 41.90% (w/w) (1218 - 1139 cm–1, Phe/Trp/Tyr C-H/C-n/C-C6H5 vibrations). The data speak to the power of FT-IR spectroscopy as a non-invasive tool to diagnose tissue disorders such as skin, liver, kidney or any other type that would require a noninvasive tool like FT-IR, to prevent further dam-age during the diagnosis. These results also dem.n-strate an age-mediated decrease of skin-GAG content, and GAG-n-acetylation, in addition to protein com-position concentration increm.nts.

关键词： Infrared Spectroscopy Glycosam.noglycans Skin Age

不同pH值培养液对肝细胞一氧化氮合成的影响

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中华消化杂志 2000年第1期20卷 26-29页

作者：舒志军韩伏莅 jung m Beger HG nuessler AK 上海市中西医结合医院普外科 200082 上海市中西医结合医院神经内科 200082 Departm.nt of General Surgery University Clinicat Safranberg Departm.nt of General SurgeryUniversity Clinicat Safranberg

目的　探讨不同 pH值条件对肝细胞培养时一氧化氮 (nO)产生的影响及对肝细胞的损伤程度。方法　本研究首先将成年健康大鼠经静脉注射灭活有毒棒状杆菌 ,感染 4天后处死动物取肝脏作肝细胞分离并培养 ,2 4h后在培养液中加入L 精氨酸 ,同... 详细信息

目的　探讨不同 pH值条件对肝细胞培养时一氧化氮 (nO)产生的影响及对肝细胞的损伤程度。方法　本研究首先将成年健康大鼠经静脉注射灭活有毒棒状杆菌 ,感染 4天后处死动物取肝脏作肝细胞分离并培养 ,2 4h后在培养液中加入L 精氨酸 ,同时将培养液调节成pH7.0、pH7.4及 pH7.8三组 ,又在每一 pH处理组中分出对照组 (CP组 )、大肠杆菌内毒素刺激组 (CP +LPS组 )及单甲基精氨酸抑制组 (CP +LPS +nmA组 ) ,继续培养 2 4h。结果　CP组产生约 10 0 μmol/L的nO ,pH值的改变对其无明显影响。在CP +LPS处理的肝细胞 ,pH7.4及 pH7.8组的值分别为 (2 39.3± 18) μmol/L及(2 2 8.4± 14.7) μmol/L ,显著高于pH7.0组 ((16 3.2± 5 .7) μmol/L ,P nmA后 ,一氧化氮的产生明显减少 ,但三组间差异无显著性。加用LPS后肝细胞的损伤加重 ,pH7.0组LDH及ALT值显著高于 pH7.4及pH7.8组。当应用nmA抑制nO生成时 ,培养液中乳酸脱氢酶 (LDH)和丙氨酸转氨酶 (ALT)值显著升高 ,并以酸性组为明显。在CP组肝细胞 ,inOS的产生量在三种不同 pH处理间无明显差别 ,加用LPS刺激后 ,inOS的合成明显增加 ,而且酸性或碱性情况下inOS的合成较 pH7.4时更高。结论　对处于炎症状态的肝细胞 ,酸性环境会抑制一氧化氮合成。

关键词：一氧化氮合成肝细胞损害 pH值培养液

“One stone,two birds”solvent system to fabricate microcrystalline cellulose–Ti_(3)C_(2)T_(x)nanocomposite film as a flexible dielectric and thermally conductive material

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nano Research 2023年第2期16卷 3240-3253页

作者： Yong-Zhu Yan Shuwei Li Sung Soo Park Wei-Jin Zhang Jun Seok Lee jung Rae Kim Dong Gi Seong Chang-Sik Ha Departm.nt of Polymer Science and Engineering School of Chemical EngineeringPusan National UniversityBusan 46241Republic of Korea School of Chemical and Biomolecular Engineering Pusan National UniversityBusan 46241Republic of Korea Division of Advanced materials Engineering Dong-Eui UniversityBusan 47340Republic of Korea

A strategy for fabricating microcrystalline cellulose–Ti_(3)C_(2)T_(x)(mCC–mXene)nanocomposite films with high relative permittivity,high thermal conductivity,and excellent mechanical properties was *** mCC–mXene nanocomposite film was fabricated by casting a solution containing n,n-dimethylacetamide/lithium chloride(DmAc/LiCl)-soluble mCC and DmAcdispersible mXene nanosheets,followed by humidity control *** mXene nanosheets greatly enhanced the permittivity of the nanocomposite films owing to interfacial ***,the nanocomposite film with 20 wt.%mXene content achieved a desirable permittivity of 71.4 at 102 Hz(a 770%improvem.nt against that of neat cellulose),while the dielectric loss only increased by 1.8 times(from 0.39 to 0.70).The obtained nanocomposite films with 20 wt.%and 30 wt.%mXene exhibited remarkable in-plane thermal conductivities of 8.523 and 9.668 W∙m^(−1)∙K^(−1),respectively,owing to the uniform dispersion and selfalignm.nt of the mXene layered ***,the uniformly dispersed mXene nanosheets in the mCC network with interfacial interaction(hydrogen bonding)and mechanical entanglem.nt endowed the nanocomposite films with excellent mechanical properties and ***,the thermal stability,water resistance,and antibacterial properties of the nanocomposite films were effectively improved with the introduction of ***,using DmAc/LiCl as the solvent system.not only improves the compatibility between mCC and mXene but also avoids the problem of easy oxidation of mXene in aqueous *** the high stability of the mCC–mXene solution and enhanced properties of the mCC–mXene films,the proposed strategy m.nifests great potential for fabricating natural biomass-based dielectric materials.

关键词： Ti_(3)C_(2)T_(x) microcrystalline cellulose flexible dielectric thermally conductive n,n-dimethylacetamide/lithium chloride(DmAc/LiCl) compatibility