国际癌症研究机构(International Agency for Research on Cancer,IARC)把镍化合物定为Ⅰ类致癌物。国际劳工组织(International Labour Organization,ILO)也把镍化合物列为职业性癌症的致癌因素。目前我国正在修订《职业病分类和目录》...国际癌症研究机构(International Agency for Research on Cancer,IARC)把镍化合物定为Ⅰ类致癌物。国际劳工组织(International Labour Organization,ILO)也把镍化合物列为职业性癌症的致癌因素。目前我国正在修订《职业病分类和目录》,镍化合物所致癌症也可能列入法定职业病。2022年ILO出版的《职业病诊断与接触标准》对镍化合物的致病特征、职业接触情况、主要健康影响、诊断标准及预防关键措施等内容做了详细论述,本文主要对其内容进行介绍,为我国制定相关标准提供依据。展开更多
The Ni-Co-Cr-W-Mo system is critical for the design of nickel-based superalloys.This system stabilizes different topologically close-packed(TCP)phases in many commercially superalloys with high W and Mo contents.Scann...The Ni-Co-Cr-W-Mo system is critical for the design of nickel-based superalloys.This system stabilizes different topologically close-packed(TCP)phases in many commercially superalloys with high W and Mo contents.Scanning electron microscopy(SEM),transmission electron microscopy(TEM)and thermodynamic calculations were applied to investigate the thermodynamics of the precipitates in two different W-contained Ni-Co-Cr-WMo superalloys(Alloy 1 and Alloy 2).Computational thermodynamics verifies the experimental observation of theμphase formation as a function of temperature and alloy chemistry,but the kinetics for the precipitation of the M6 C phase do not agree with the experimental findings.The major precipitates of Alloy 1 at temperatures of700℃and 750℃during long-time exposure are M23 C6,γ′phase and MC;for Alloy 2,they are M23 C6,γ′phase,MC,M6 C andμphase.W addition is found to promote the precipitation of M6 C andμphase during exposure.M6 C has higher W and lower Ni content thanμphase,whereas M6 C is an unstable phase that would transform into M12 C after 5000-h exposure at 750℃.A great quantity of needle-likeμphases precipitated after exposure at 750℃for5000 h,which have no effect on the impact properties of Alloy 2.展开更多
Low-cycle fatigue(LCF) behavior of the directionally solidified(DS) nickel-based DZ125 superalloy was studied at elevated temperature(980 ℃).Specimens were,respectively,exposed for 0,2,25,50,and 100 h in air.The fati...Low-cycle fatigue(LCF) behavior of the directionally solidified(DS) nickel-based DZ125 superalloy was studied at elevated temperature(980 ℃).Specimens were,respectively,exposed for 0,2,25,50,and 100 h in air.The fatigue life of pre-exposed specimens is lower than that of unexposed specimens.The result is closely associated with fatigue crack initiation and propagation due to oxygen embrittlement and cycle loading.Detailed fractographic evaluations indicate the fatigue life is closely related to the surface microstructural modification.The resulting changes in microstructure cause the decrease in the effective area and the increase in actual stress.A methodology based on the continuum damage mechanics is developed to describe the correlation between the residual LCF life and pre-exposed time.展开更多
Objectives: Occupational exposure to nickel is affecting millions of employees around the world. Potential alterations in the genetic material of workers in the mining and processing of nickel, possibly resulting from...Objectives: Occupational exposure to nickel is affecting millions of employees around the world. Potential alterations in the genetic material of workers in the mining and processing of nickel, possibly resulting from exposure to nickel in the production process, were investigated. The study focused on assessing the percentage of induced micronuclei, as well as on changes in the various cell types of oral mucosa epithelium. Methods: The buccal micronucleus assay was employed to assess possible induced genetic alterations to production line workers in comparison to office employees of the same nickel mining and pyrometalurgic processing industry. Subjects were also compared with regard to their smoking habit. Results: Very low soluble nickel levels were measured in certain workplaces and only in one workplace insoluble nickel was above the acceptable level. Statistically significant micronuclei differences among smokers and non-smokers, in both study groups as well as in total, were observed (p less than 0.01). Production line workers appeared with statistically significant induced micronuclei compared to office employees. Non-smoker production line workers compared to non-smoker office employees revealed statistically significant induced micronuclei. Statistically significant cell lesions were detected between non-smokers and smokers among office employees and production line workers documenting Ni engagement in their induction. Conclusions: The observed frequencies of micronuclei and cell lesions in the oral mucosa of workers, in certain positions of the production line, in relation to their smoking habit document the synergistic effect of Ni and cigarette smoking as effectors in their induction.展开更多
A significant number of birds in the port town of Esperance, Western Australia died in the summer of 2006/2007 and elevated lead levels were found in the kidneys, livers and brains of autopsied birds. These elevated l...A significant number of birds in the port town of Esperance, Western Australia died in the summer of 2006/2007 and elevated lead levels were found in the kidneys, livers and brains of autopsied birds. These elevated lead levels alerted Government authorities to investigate the public health impacts of potential lead contamination in the community resulting from transport of lead carbonate from the Esperance Port. Water samples from domestic rainwater collection systems were collected to determine the extent of heavy metal contamination;19% and 24% of tanks had lead and nickel levels above the Australian Drinking Water Guidelines. The aim of this study was to evaluate whether cleaning of rainwater tanks had reduced exposure to lead and nickel contamination in the community. Follow-up sampling of 176 tanks across Esperance indi-cated that that there had been reductions in both lead and nickel concentrations, but that the reduction has been greater for nickel concentrations. The reduction in nickel concentration was significantly associated with cleaning status, whereas this was not the case for lead. Proximity to the Esperance Port was an impor-tant determinant of lead concentration. Tank and roof characteristics did not significantly influence the fol-low-up lead concentrations. The results suggested that there was ongoing contamination of rainwater tanks from the environment.展开更多
A new fluorescence silver nanosensor assisted by surfactant has been recently synthesized and applied to ultra trace nickel determination. The methodology was validated by the standard addition method and satisfactori...A new fluorescence silver nanosensor assisted by surfactant has been recently synthesized and applied to ultra trace nickel determination. The methodology was validated by the standard addition method and satisfactorily applied to nickel determination in urine without previous treatment, coming from subjects with different smoking addiction levels and second hand smokers. Within-day precision was better than 0.011 CV. The reproducibility （between-days precision） was also evaluated over 3 days by performing six determinations each day with a CV of 0.025. The proposed methodology represents a promising approach in the area of biological monitoring due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents. Obtained results of urinary nickel concentration were successfully correlated with the tobacco addiction.展开更多
文摘国际癌症研究机构(International Agency for Research on Cancer,IARC)把镍化合物定为Ⅰ类致癌物。国际劳工组织(International Labour Organization,ILO)也把镍化合物列为职业性癌症的致癌因素。目前我国正在修订《职业病分类和目录》,镍化合物所致癌症也可能列入法定职业病。2022年ILO出版的《职业病诊断与接触标准》对镍化合物的致病特征、职业接触情况、主要健康影响、诊断标准及预防关键措施等内容做了详细论述,本文主要对其内容进行介绍,为我国制定相关标准提供依据。
基金financially supported by the National Key Research and Develop Program,China(No.2017YFB0305203)。
文摘The Ni-Co-Cr-W-Mo system is critical for the design of nickel-based superalloys.This system stabilizes different topologically close-packed(TCP)phases in many commercially superalloys with high W and Mo contents.Scanning electron microscopy(SEM),transmission electron microscopy(TEM)and thermodynamic calculations were applied to investigate the thermodynamics of the precipitates in two different W-contained Ni-Co-Cr-WMo superalloys(Alloy 1 and Alloy 2).Computational thermodynamics verifies the experimental observation of theμphase formation as a function of temperature and alloy chemistry,but the kinetics for the precipitation of the M6 C phase do not agree with the experimental findings.The major precipitates of Alloy 1 at temperatures of700℃and 750℃during long-time exposure are M23 C6,γ′phase and MC;for Alloy 2,they are M23 C6,γ′phase,MC,M6 C andμphase.W addition is found to promote the precipitation of M6 C andμphase during exposure.M6 C has higher W and lower Ni content thanμphase,whereas M6 C is an unstable phase that would transform into M12 C after 5000-h exposure at 750℃.A great quantity of needle-likeμphases precipitated after exposure at 750℃for5000 h,which have no effect on the impact properties of Alloy 2.
基金financially supported by the National Natural Science Foundation of China (No.51571010)the National Basic Research Program of China (No.2015CB057400)。
文摘Low-cycle fatigue(LCF) behavior of the directionally solidified(DS) nickel-based DZ125 superalloy was studied at elevated temperature(980 ℃).Specimens were,respectively,exposed for 0,2,25,50,and 100 h in air.The fatigue life of pre-exposed specimens is lower than that of unexposed specimens.The result is closely associated with fatigue crack initiation and propagation due to oxygen embrittlement and cycle loading.Detailed fractographic evaluations indicate the fatigue life is closely related to the surface microstructural modification.The resulting changes in microstructure cause the decrease in the effective area and the increase in actual stress.A methodology based on the continuum damage mechanics is developed to describe the correlation between the residual LCF life and pre-exposed time.
文摘Objectives: Occupational exposure to nickel is affecting millions of employees around the world. Potential alterations in the genetic material of workers in the mining and processing of nickel, possibly resulting from exposure to nickel in the production process, were investigated. The study focused on assessing the percentage of induced micronuclei, as well as on changes in the various cell types of oral mucosa epithelium. Methods: The buccal micronucleus assay was employed to assess possible induced genetic alterations to production line workers in comparison to office employees of the same nickel mining and pyrometalurgic processing industry. Subjects were also compared with regard to their smoking habit. Results: Very low soluble nickel levels were measured in certain workplaces and only in one workplace insoluble nickel was above the acceptable level. Statistically significant micronuclei differences among smokers and non-smokers, in both study groups as well as in total, were observed (p less than 0.01). Production line workers appeared with statistically significant induced micronuclei compared to office employees. Non-smoker production line workers compared to non-smoker office employees revealed statistically significant induced micronuclei. Statistically significant cell lesions were detected between non-smokers and smokers among office employees and production line workers documenting Ni engagement in their induction. Conclusions: The observed frequencies of micronuclei and cell lesions in the oral mucosa of workers, in certain positions of the production line, in relation to their smoking habit document the synergistic effect of Ni and cigarette smoking as effectors in their induction.
文摘A significant number of birds in the port town of Esperance, Western Australia died in the summer of 2006/2007 and elevated lead levels were found in the kidneys, livers and brains of autopsied birds. These elevated lead levels alerted Government authorities to investigate the public health impacts of potential lead contamination in the community resulting from transport of lead carbonate from the Esperance Port. Water samples from domestic rainwater collection systems were collected to determine the extent of heavy metal contamination;19% and 24% of tanks had lead and nickel levels above the Australian Drinking Water Guidelines. The aim of this study was to evaluate whether cleaning of rainwater tanks had reduced exposure to lead and nickel contamination in the community. Follow-up sampling of 176 tanks across Esperance indi-cated that that there had been reductions in both lead and nickel concentrations, but that the reduction has been greater for nickel concentrations. The reduction in nickel concentration was significantly associated with cleaning status, whereas this was not the case for lead. Proximity to the Esperance Port was an impor-tant determinant of lead concentration. Tank and roof characteristics did not significantly influence the fol-low-up lead concentrations. The results suggested that there was ongoing contamination of rainwater tanks from the environment.
文摘A new fluorescence silver nanosensor assisted by surfactant has been recently synthesized and applied to ultra trace nickel determination. The methodology was validated by the standard addition method and satisfactorily applied to nickel determination in urine without previous treatment, coming from subjects with different smoking addiction levels and second hand smokers. Within-day precision was better than 0.011 CV. The reproducibility （between-days precision） was also evaluated over 3 days by performing six determinations each day with a CV of 0.025. The proposed methodology represents a promising approach in the area of biological monitoring due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents. Obtained results of urinary nickel concentration were successfully correlated with the tobacco addiction.
