In order to obtain a high-performance surface on P110 steel that can meet the requirements in oil/gas field environment, the chromium coatings were fabricated by pack cementation. The chromium coatings differed in wit...In order to obtain a high-performance surface on P110 steel that can meet the requirements in oil/gas field environment, the chromium coatings were fabricated by pack cementation. The chromium coatings differed in with/without the addition of La2O3. Scanning electron microscope （SEM）, energy dispersive X-ray spectrometer （EDS）, X-ray diffractometer （XRD） and microhardness tester were employed to investigate the surface morphologies, surface element distributions, microstructures, phase constitutions and microhardness of the coatings. Friction-wear tests of the P110 steel substrate and the coatings were conducted in air at ambient temperature and humidity. The results show that ＇uniform and continuous coatings are formed on P110 steel regardless of adding La2O3 or not. The chromium coatings consist of Cr23C6, Cr7C3, and （Cr, Fe）7C3. The La2O3-added chromium coating is more beneficial in terms of surface morphology, microstructure, thickness and microharduess as compared with the coating without adding La2O3. Chromizing treatment significantly improves the surface hardness and wear resistance of the P110 steel. The wear resistance of the tested samples can be sorted in the following sequence： La2O3-coating 〉 no RE-coating 〉bare P110 steel.展开更多
The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance ...The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe2O4 when content of CaO is less than 4%(mass fraction), bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 MPa, but that of the samples without CaO is only 60 MPa. Fracture toughness is improved obviously by CaO doping, the samples doped with 2% CaO have the maximum fracture toughness of 2.12 MPa ·m1/2 , which is about two times of that of the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe2O4 composite ceramics.展开更多
The CaO-doped Cu/（NiFe2O4-10NiO） cermet inert anodes were prepared by the cold isostatie pressing-sintering process, and their corrosion resistance to Na3AlF6-K3AlF6-Al203 melt was studied. The results show that the...The CaO-doped Cu/（NiFe2O4-10NiO） cermet inert anodes were prepared by the cold isostatie pressing-sintering process, and their corrosion resistance to Na3AlF6-K3AlF6-Al203 melt was studied. The results show that the relative density of 5Cu/（NiFe2O4-10NiO） cermet sintered at 1 200 ℃ increases from 82.83% to 97.63% when 2% CaO （mass fraction） is added. During the electrolysis, the relative density of cermet inert anode descends owing to the chemical dissolution of additive CaO at ceramic grain boundary, which accelerates the penetration of electrolyte. Thus, the corrosion resistance to melts of Cu/（NiFe2O4-10NiO） cermet inert anode is reduced. To improve the corrosion resistance of the cermet inert anode, the content of CaO doped should be decreased and the technology of cleaning the ceramic grain boundary should be applied.展开更多
目的肿瘤高表达多药耐药相关转运蛋白三磷酸腺苷结合转运蛋白G家族成员2(ATP-binding cassette super family G member 2,ABCG2)是造成耐药及化疗失败的主要原因。文中旨在探讨环磷酰胺体内干预后肾上腺皮质癌细胞中ABCG2表达的意义。方...目的肿瘤高表达多药耐药相关转运蛋白三磷酸腺苷结合转运蛋白G家族成员2(ATP-binding cassette super family G member 2,ABCG2)是造成耐药及化疗失败的主要原因。文中旨在探讨环磷酰胺体内干预后肾上腺皮质癌细胞中ABCG2表达的意义。方法 BALB/C-nu裸鼠共10只,雌雄不拘,随机数表法分为对照组和环磷酰胺组,每组5只。将SW-13细胞注射入裸鼠皮下建立裸鼠皮下移植瘤模型,环磷酰胺组予腹腔注射环磷酰胺,对照组予注射等量等渗盐水,并对获得的2组瘤体组织进行原代培养。用免疫组化法(阳性肿瘤细胞百分比<10%者为阴性,≥10%为阳性)和流式细胞法分别检测瘤体组织及原代细胞株ABCG2的表达。结果流式细胞法检测ABCG2在环磷酰胺组细胞中表达率[(97.89±1.36)%]高于对照组细胞[(81.88±8.31)%],差异有统计学意义(P<0.05),免疫组化结果提示环磷酰胺组瘤体组织中ABCG2表达阳性率[(69.1±1.83)%]高于对照组[(53.4±1.65)%],差异有统计学意义(P<0.05)。结论多药耐药基因ABCG2参与肾上腺皮质癌耐药,可能为肾上腺皮质癌干预靶点。展开更多
肺癌细胞的干性及耐药性是重要的恶性指标。ATP结合盒蛋白G超家族成员2(ATP-binding cassette superfamily G member 2,ABCG2)是细胞表面的ATP结合盒蛋白家族的成员之一,依赖ATP可将药物排到细胞外。ABCG2定位于人多种肿瘤细胞的膜上,...肺癌细胞的干性及耐药性是重要的恶性指标。ATP结合盒蛋白G超家族成员2(ATP-binding cassette superfamily G member 2,ABCG2)是细胞表面的ATP结合盒蛋白家族的成员之一,依赖ATP可将药物排到细胞外。ABCG2定位于人多种肿瘤细胞的膜上,它的表达与肿瘤化学治疗多药耐药性紧密相关,目前被认为是肺癌干细胞鉴定的辅助群体标志物。此外,ABCG2的一些单核苷酸多态性与肺癌多药耐药性存在显著相关性。该文就最新ABCG2相关研究进展进行总结和归纳,重点介绍ABCG2基因的表达调控、ABCG2与肺癌干性的关系以及ABCG2的单核苷酸多态性与肺癌耐药性的相关性研究,以期为肺癌患者的临床治疗提供新的策略。展开更多
NiFe2O4-based cermet inert anodes with metallic phase compositions of Cu, Ni and 85Cu15Ni were prepared by cold pressing-sintering. Their corrosion resistance was also investigated in Na3 AIF6-Al2O3 melts. The resuits...NiFe2O4-based cermet inert anodes with metallic phase compositions of Cu, Ni and 85Cu15Ni were prepared by cold pressing-sintering. Their corrosion resistance was also investigated in Na3 AIF6-Al2O3 melts. The resuits show that the metallic phase species in cermets have no effect on the concentration of impurities in bath during electrolysis, the total steady-state concentration of impurities is almost the same, i.e. between 4.12 × 10^-4- 4.80 × 10^-4. There exists metal preferential corrosion for the cermet inert anode with metal Ni as metallic phase. For NiFe2 O4-based cermets, the cermet with metal Cu as metallic phase exhibits better corrosion resistance than the others.展开更多
基金Project(2007CB607603) supported by the National Basic Research Program of China
文摘In order to obtain a high-performance surface on P110 steel that can meet the requirements in oil/gas field environment, the chromium coatings were fabricated by pack cementation. The chromium coatings differed in with/without the addition of La2O3. Scanning electron microscope （SEM）, energy dispersive X-ray spectrometer （EDS）, X-ray diffractometer （XRD） and microhardness tester were employed to investigate the surface morphologies, surface element distributions, microstructures, phase constitutions and microhardness of the coatings. Friction-wear tests of the P110 steel substrate and the coatings were conducted in air at ambient temperature and humidity. The results show that ＇uniform and continuous coatings are formed on P110 steel regardless of adding La2O3 or not. The chromium coatings consist of Cr23C6, Cr7C3, and （Cr, Fe）7C3. The La2O3-added chromium coating is more beneficial in terms of surface morphology, microstructure, thickness and microharduess as compared with the coating without adding La2O3. Chromizing treatment significantly improves the surface hardness and wear resistance of the P110 steel. The wear resistance of the tested samples can be sorted in the following sequence： La2O3-coating 〉 no RE-coating 〉bare P110 steel.
基金Project(2005CB623703) supported by the National Basic Research Program of China
文摘The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe2O4 when content of CaO is less than 4%(mass fraction), bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 MPa, but that of the samples without CaO is only 60 MPa. Fracture toughness is improved obviously by CaO doping, the samples doped with 2% CaO have the maximum fracture toughness of 2.12 MPa ·m1/2 , which is about two times of that of the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe2O4 composite ceramics.
基金Project(2005CB623703) supported by the Major State Basic Research and Development Program of ChinaProject(2008AA030503) supported by Hi-Tech Research and Development Program of China
文摘The CaO-doped Cu/（NiFe2O4-10NiO） cermet inert anodes were prepared by the cold isostatie pressing-sintering process, and their corrosion resistance to Na3AlF6-K3AlF6-Al203 melt was studied. The results show that the relative density of 5Cu/（NiFe2O4-10NiO） cermet sintered at 1 200 ℃ increases from 82.83% to 97.63% when 2% CaO （mass fraction） is added. During the electrolysis, the relative density of cermet inert anode descends owing to the chemical dissolution of additive CaO at ceramic grain boundary, which accelerates the penetration of electrolyte. Thus, the corrosion resistance to melts of Cu/（NiFe2O4-10NiO） cermet inert anode is reduced. To improve the corrosion resistance of the cermet inert anode, the content of CaO doped should be decreased and the technology of cleaning the ceramic grain boundary should be applied.
文摘目的肿瘤高表达多药耐药相关转运蛋白三磷酸腺苷结合转运蛋白G家族成员2(ATP-binding cassette super family G member 2,ABCG2)是造成耐药及化疗失败的主要原因。文中旨在探讨环磷酰胺体内干预后肾上腺皮质癌细胞中ABCG2表达的意义。方法 BALB/C-nu裸鼠共10只,雌雄不拘,随机数表法分为对照组和环磷酰胺组,每组5只。将SW-13细胞注射入裸鼠皮下建立裸鼠皮下移植瘤模型,环磷酰胺组予腹腔注射环磷酰胺,对照组予注射等量等渗盐水,并对获得的2组瘤体组织进行原代培养。用免疫组化法(阳性肿瘤细胞百分比<10%者为阴性,≥10%为阳性)和流式细胞法分别检测瘤体组织及原代细胞株ABCG2的表达。结果流式细胞法检测ABCG2在环磷酰胺组细胞中表达率[(97.89±1.36)%]高于对照组细胞[(81.88±8.31)%],差异有统计学意义(P<0.05),免疫组化结果提示环磷酰胺组瘤体组织中ABCG2表达阳性率[(69.1±1.83)%]高于对照组[(53.4±1.65)%],差异有统计学意义(P<0.05)。结论多药耐药基因ABCG2参与肾上腺皮质癌耐药,可能为肾上腺皮质癌干预靶点。
文摘肺癌细胞的干性及耐药性是重要的恶性指标。ATP结合盒蛋白G超家族成员2(ATP-binding cassette superfamily G member 2,ABCG2)是细胞表面的ATP结合盒蛋白家族的成员之一,依赖ATP可将药物排到细胞外。ABCG2定位于人多种肿瘤细胞的膜上,它的表达与肿瘤化学治疗多药耐药性紧密相关,目前被认为是肺癌干细胞鉴定的辅助群体标志物。此外,ABCG2的一些单核苷酸多态性与肺癌多药耐药性存在显著相关性。该文就最新ABCG2相关研究进展进行总结和归纳,重点介绍ABCG2基因的表达调控、ABCG2与肺癌干性的关系以及ABCG2的单核苷酸多态性与肺癌耐药性的相关性研究,以期为肺癌患者的临床治疗提供新的策略。
基金Project(2005CB623703) supported by the National Basic Research Programof China project(03JJY3080) supported bythe Hunan Provincial Natural Science Foundation
文摘NiFe2O4-based cermet inert anodes with metallic phase compositions of Cu, Ni and 85Cu15Ni were prepared by cold pressing-sintering. Their corrosion resistance was also investigated in Na3 AIF6-Al2O3 melts. The resuits show that the metallic phase species in cermets have no effect on the concentration of impurities in bath during electrolysis, the total steady-state concentration of impurities is almost the same, i.e. between 4.12 × 10^-4- 4.80 × 10^-4. There exists metal preferential corrosion for the cermet inert anode with metal Ni as metallic phase. For NiFe2 O4-based cermets, the cermet with metal Cu as metallic phase exhibits better corrosion resistance than the others.
