Studying the evolution of groundwater pollutants and the causes of formation in Manzhouli is important and necessi- tous as the present water source of the production and living in Manzhouli is just groundwater and th...Studying the evolution of groundwater pollutants and the causes of formation in Manzhouli is important and necessi- tous as the present water source of the production and living in Manzhouli is just groundwater and the water crisis is staring Manzhouli people in the face. The evolution of pollutants in groundwater in Manzhouli was derived based on the continuously monitoring between 1989 and 1999. In total, the quality of groundwater in Manzhouli is good except that the content of F is exceeding the standard. The quality of groundwater varies seasonally. The content of pollutants in high water is higher than in the low water except pH and As. The yearly evolution shows the regime like the damp surge. The evolution of pH is inverse to NO3-N and F after 1999. The courses of formation of the evolution of the content of the pollutants in groundwater in Manzhouli are the supply of runoff, the feature of rock, the time the water being stayed in the layers and the chemical field. Being affected by the supply of ground surface and hydrogeology condition, the contents of pollutant are higher in the May than in September and the yearly evolution is undulance. In total, the pollutants in the deeper layers are less than in the upper layers. Explosion water in the deeper layers, using the techniques of cutting F and minifying the pollutants caused by human being are the sound countermeasures in Manzhouli.展开更多
It is generally acknowledged in heterogeneous catalysis that hydrogenation follows the so-called Horiuti-Polanyi(HP) mechanism. In this work, a thorough investigation of the mechanism of hydrogenation of hydroxyl grou...It is generally acknowledged in heterogeneous catalysis that hydrogenation follows the so-called Horiuti-Polanyi(HP) mechanism. In this work, a thorough investigation of the mechanism of hydrogenation of hydroxyl groups and O catalyzed by a series of transition metals was carried out through density functional theory calculations, as surface hydroxyls and O are very common species in many catalytic systems. It is found that different metal catalysts exhibit different mechanisms. On some metal catalysts, the non-HP mechanism is preferred, whereas the classic HP mechanism is favored on other catalysts. Detailed analyses of the metal-dependent mechanism shows that the activity toward the dissociation of H2 decides which mechanism is preferred. On active catalysts, such as Ni and Pt, H2 prefers to dissociate with strong H adsorption energies, which lead to the classic HP mechanism being favored. On inactive surfaces, on the other hand, the adsorption of H is weak, which results in the non-HP mechanism being preferred. The parameter η, which is a structural descriptor, was defined to understand the different mechanisms.展开更多
基金the auspices of the Key Project of the Chinese Academy of Sciences (KZ952 - JI - 032).
文摘Studying the evolution of groundwater pollutants and the causes of formation in Manzhouli is important and necessi- tous as the present water source of the production and living in Manzhouli is just groundwater and the water crisis is staring Manzhouli people in the face. The evolution of pollutants in groundwater in Manzhouli was derived based on the continuously monitoring between 1989 and 1999. In total, the quality of groundwater in Manzhouli is good except that the content of F is exceeding the standard. The quality of groundwater varies seasonally. The content of pollutants in high water is higher than in the low water except pH and As. The yearly evolution shows the regime like the damp surge. The evolution of pH is inverse to NO3-N and F after 1999. The courses of formation of the evolution of the content of the pollutants in groundwater in Manzhouli are the supply of runoff, the feature of rock, the time the water being stayed in the layers and the chemical field. Being affected by the supply of ground surface and hydrogeology condition, the contents of pollutant are higher in the May than in September and the yearly evolution is undulance. In total, the pollutants in the deeper layers are less than in the upper layers. Explosion water in the deeper layers, using the techniques of cutting F and minifying the pollutants caused by human being are the sound countermeasures in Manzhouli.
基金supported by the National Natural Science Foundation of China(21673072,21333003,and 91845111)~~
文摘It is generally acknowledged in heterogeneous catalysis that hydrogenation follows the so-called Horiuti-Polanyi(HP) mechanism. In this work, a thorough investigation of the mechanism of hydrogenation of hydroxyl groups and O catalyzed by a series of transition metals was carried out through density functional theory calculations, as surface hydroxyls and O are very common species in many catalytic systems. It is found that different metal catalysts exhibit different mechanisms. On some metal catalysts, the non-HP mechanism is preferred, whereas the classic HP mechanism is favored on other catalysts. Detailed analyses of the metal-dependent mechanism shows that the activity toward the dissociation of H2 decides which mechanism is preferred. On active catalysts, such as Ni and Pt, H2 prefers to dissociate with strong H adsorption energies, which lead to the classic HP mechanism being favored. On inactive surfaces, on the other hand, the adsorption of H is weak, which results in the non-HP mechanism being preferred. The parameter η, which is a structural descriptor, was defined to understand the different mechanisms.
