Groundwater pollution in north China is serious, which is mostly caused by complex factors. Aiming at the problems such as the unknown reasons for the differences in the migration characteristics of typical characteri...Groundwater pollution in north China is serious, which is mostly caused by complex factors. Aiming at the problems such as the unknown reasons for the differences in the migration characteristics of typical characteristic pollutants in the same medium and the unknown migration rules of complex pollutants in soil and groundwater, this paper selected a single sample and a mixed sample of typical characteristic pollutants in coking enterprises to carry out the static adsorption test. The results showed that the distribution coefficients of benzene series and aromatic hydrocarbon pollutants in soil-water were K_(d)benzene >K_(d)toluene >K_(d)ethylbenzene >K_(d)pyrene >K_(d)anthracene >K_(d)naphthene, and the distribution coefficients of ammonia nitrogen, phenols and cyanogen were K_(d)ammonia nitrogen >K_(d)phenols >K_(d)cyanogen. The overall distribution coefficient of benzene series was higher than that of PAHs, and it was easier to be adsorbed by silty loam. Different carbon and hydrogen mass and even electron distribution of typical characteristic pollutants led to differences in the migration characteristics of benzene and aromatic pollutants. The more carbon and hydrogen there were, the more even the electron distribution was, and the more difficult it was to migrate in the soil. Among the same kind of pollutants, the migration of complex pollutants was weaker than that of single pollutants. The research could provide the parameter basis for establishing the solute transport model of groundwater and the design basis for developing the related risk control and pollution prevention strategies.展开更多
This paper reports some first results obtained from a study conducted on work integration social enterprises （WISEs） in the framework of the social and solidarity economy （SSE） and the integration of international...This paper reports some first results obtained from a study conducted on work integration social enterprises （WISEs） in the framework of the social and solidarity economy （SSE） and the integration of international migrants. WISEs, as hybrid transit companies, go beyond a pure economic rationale, enabling labor and social inclusion for disadvantaged groups, international migrants included, through an insertion process in a real job performance environment. Therefore, WISEs should be understood as valuable mechanisms for achieving optimal levels of personal empowerment and social and labor integration in their active use and enhancement of these employees＇ capacities and competences. All of these aspects of WISEs have an impact on social justice in helping construct a more inclusive growth and society and foster the integration of international migrants.展开更多
Narrowband photodetectors conventionally rely on optical structure design orbandpass filters to achieve the narrowband regime. Recently, a strategy forfilterless narrowband photoresponse based on the charge collection...Narrowband photodetectors conventionally rely on optical structure design orbandpass filters to achieve the narrowband regime. Recently, a strategy forfilterless narrowband photoresponse based on the charge collection narrowing(CCN) mechanism was reported. However, the CCN strategy requires an electrically and optically “thick” photoactive layer, which poses challenges in controlling the narrowband photoresponse. Here we propose a novel strategy forconstructing narrowband photodetectors by leveraging the inherent ion migration in perovskites, which we term “band modulation narrowing” (BMN). Bymanipulating the ion migration with external stimuli such as illumination,temperature, and bias voltage, we can regulate in situ the energy-band structure of perovskite photodetectors (PPDs) and hence their spectral response.Combining the Fermi energy levels obtained by the Kelvin probe force microscopy, the internal potential profiles from solar cell capacitance simulator simulation, and the anion accumulation revealed by the transient ion-drifttechnique, we discover two critical mechanisms behind our BMN strategy: theextension of an optically active but electronically dead region proximal to the top electrode and the down-bending energy bands near the electron transportlayer. Our findings offer a case for harnessing the often-annoying ionmigration for developing advanced narrowband PPDs.展开更多
AIM:To remove the migrated bands using a gastrointestinal endoscopic approach.Little is published on complications that can occur.METHODS:From June 2006 to June 2010,eight patients developed intragastric band migratio...AIM:To remove the migrated bands using a gastrointestinal endoscopic approach.Little is published on complications that can occur.METHODS:From June 2006 to June 2010,eight patients developed intragastric band migration.Two patients had received their AGB in a different hospital,theremaining six were operated by the same surgeon.In all patients gastrointestinal endoscopic removal of the band was attempted by two individual gastroenterologists.Clinical signs of band migration were:persisted nausea,abdominal pain,weight gain,recurrent infection of the port and tubing system and hematemesis.RESULTS:In four patients removal was performed without complications.In two patients extracting the cleaved gastric band into the stomach appeared impossible.The two remaining patients presented with acute hematemesis and melena.One of these patients was readmitted with hematemesis.The other patient started bleeding during the gastroscopy and was converted to a laparoscopy in which one of the branches of the left gastric artery was oversewn.CONCLUSION:Band migration after gastric banding can be life threatening.Gastrointestinal endoscopic removal is a feasible technique that holds the promise of fast reconvalescence.展开更多
基金Supported by Hebei Natural Science Fund (D2021106004)。
文摘Groundwater pollution in north China is serious, which is mostly caused by complex factors. Aiming at the problems such as the unknown reasons for the differences in the migration characteristics of typical characteristic pollutants in the same medium and the unknown migration rules of complex pollutants in soil and groundwater, this paper selected a single sample and a mixed sample of typical characteristic pollutants in coking enterprises to carry out the static adsorption test. The results showed that the distribution coefficients of benzene series and aromatic hydrocarbon pollutants in soil-water were K_(d)benzene >K_(d)toluene >K_(d)ethylbenzene >K_(d)pyrene >K_(d)anthracene >K_(d)naphthene, and the distribution coefficients of ammonia nitrogen, phenols and cyanogen were K_(d)ammonia nitrogen >K_(d)phenols >K_(d)cyanogen. The overall distribution coefficient of benzene series was higher than that of PAHs, and it was easier to be adsorbed by silty loam. Different carbon and hydrogen mass and even electron distribution of typical characteristic pollutants led to differences in the migration characteristics of benzene and aromatic pollutants. The more carbon and hydrogen there were, the more even the electron distribution was, and the more difficult it was to migrate in the soil. Among the same kind of pollutants, the migration of complex pollutants was weaker than that of single pollutants. The research could provide the parameter basis for establishing the solute transport model of groundwater and the design basis for developing the related risk control and pollution prevention strategies.
文摘This paper reports some first results obtained from a study conducted on work integration social enterprises （WISEs） in the framework of the social and solidarity economy （SSE） and the integration of international migrants. WISEs, as hybrid transit companies, go beyond a pure economic rationale, enabling labor and social inclusion for disadvantaged groups, international migrants included, through an insertion process in a real job performance environment. Therefore, WISEs should be understood as valuable mechanisms for achieving optimal levels of personal empowerment and social and labor integration in their active use and enhancement of these employees＇ capacities and competences. All of these aspects of WISEs have an impact on social justice in helping construct a more inclusive growth and society and foster the integration of international migrants.
基金National Natural Science Foundation of China,Grant/Award Numbers:21972006,22275180,U2001217,22261160370,52202182Shenzhen Peacock plan,Grant/Award Number:KQTD2016053015544057+1 种基金Shenzhen Innovation Fund,Grant/Award Number:JCYJ20220818101018038Natural Sciences and Engineering Research Council of Canada,Grant/Award Number:RGPIN-2020-04239。
文摘Narrowband photodetectors conventionally rely on optical structure design orbandpass filters to achieve the narrowband regime. Recently, a strategy forfilterless narrowband photoresponse based on the charge collection narrowing(CCN) mechanism was reported. However, the CCN strategy requires an electrically and optically “thick” photoactive layer, which poses challenges in controlling the narrowband photoresponse. Here we propose a novel strategy forconstructing narrowband photodetectors by leveraging the inherent ion migration in perovskites, which we term “band modulation narrowing” (BMN). Bymanipulating the ion migration with external stimuli such as illumination,temperature, and bias voltage, we can regulate in situ the energy-band structure of perovskite photodetectors (PPDs) and hence their spectral response.Combining the Fermi energy levels obtained by the Kelvin probe force microscopy, the internal potential profiles from solar cell capacitance simulator simulation, and the anion accumulation revealed by the transient ion-drifttechnique, we discover two critical mechanisms behind our BMN strategy: theextension of an optically active but electronically dead region proximal to the top electrode and the down-bending energy bands near the electron transportlayer. Our findings offer a case for harnessing the often-annoying ionmigration for developing advanced narrowband PPDs.
文摘AIM:To remove the migrated bands using a gastrointestinal endoscopic approach.Little is published on complications that can occur.METHODS:From June 2006 to June 2010,eight patients developed intragastric band migration.Two patients had received their AGB in a different hospital,theremaining six were operated by the same surgeon.In all patients gastrointestinal endoscopic removal of the band was attempted by two individual gastroenterologists.Clinical signs of band migration were:persisted nausea,abdominal pain,weight gain,recurrent infection of the port and tubing system and hematemesis.RESULTS:In four patients removal was performed without complications.In two patients extracting the cleaved gastric band into the stomach appeared impossible.The two remaining patients presented with acute hematemesis and melena.One of these patients was readmitted with hematemesis.The other patient started bleeding during the gastroscopy and was converted to a laparoscopy in which one of the branches of the left gastric artery was oversewn.CONCLUSION:Band migration after gastric banding can be life threatening.Gastrointestinal endoscopic removal is a feasible technique that holds the promise of fast reconvalescence.
基金This study was supported by the National Natural Science Foundation of China(31201725)the Applicable Basic research Project of Yunnan Province(2012FB186)the Western Light Talents Programme of Chinese Academy of Sciences.
