The electrolysis of water powered by renewable energy sources offers a promising method of"green hydrogen"production,which is considered to be at the heart of future carbon-neutral energy systems.In the past...The electrolysis of water powered by renewable energy sources offers a promising method of"green hydrogen"production,which is considered to be at the heart of future carbon-neutral energy systems.In the past decades,researchers have reported a number of hydrogen evolution reaction(HER)electrocatalysts with activity comparable to that of commercial Pt/C,but most of them are tested within a small current density range,typically no more than 500 mA cm^(-2).To realize the industrial application of hydrogen production from water electrolysis,it is essential to develop high-efficiency HER electrocatalysts at high current density(HCD≥500 mA cm^(-2)).Nevertheless,it remains challenging and significant to rational design HCD electrocatalysts for HER.In this paper,the design strategy of HCD electrocatalysts is discussed,and some HCD electrocatalysts for HER are reviewed in seven categories(alloy,metal oxide,metal hydroxide,metal sulfide/selenide,metal nitride,metal phosphide and other derived electrocatalysts).At the end of this article,we also pro-pose some viewpoints and prospects for the future development and research directions of HCD electrocatalysts for HER.展开更多
The present study is focused on a comparative evaluation of landslide disaster using analytical hierarchy process and information value method for hazard assessment in highly tectonic Chamba region in bosom of Himalay...The present study is focused on a comparative evaluation of landslide disaster using analytical hierarchy process and information value method for hazard assessment in highly tectonic Chamba region in bosom of Himalaya. During study, the information about the causative factors was generated and the landslide hazard zonation maps were delineated using Information Value Method(IV) and Analytical Hierarchy Process(AHP) using Arc GIS(ESRI). For this purpose, the study area was selected in a part of Ravi river catchment along one of the landslide prone Chamba to Bharmour road corridor of National Highway(NH^(-1)54 A) in Himachal Pradesh, India. A numeral landslide triggering geoenvironmental factors i.e. slope, aspect, relative relief, soil, curvature, land use and land cover(LULC), lithology, drainage density, and lineament density were selected for landslide hazard mapping based on landslide inventory. Landslide hazard zonation map was categorized namely "very high hazard, high hazard, medium hazard, low hazard, and very low hazard". The results from these two methods were validated using Area Under Curve(AUC) plots. It is found that hazard zonation map prepared using information value method and analytical hierarchy process methods possess the prediction rate of 78.87% and 75.42%, respectively. Hence, landslide hazardzonation map obtained using information value method is proposed to be more useful for the study area. These final hazard zonation maps can be used by various stakeholders like engineers and administrators for proper maintenance and smooth traffic flow between Chamba and Bharmour cities, which is the only route connecting these tourist places.展开更多
Sandu Bay is located in the East China Sea and is characterized by high-density fish farming and kelp culture. Despite this, little is known about the impacts of these different mariculture practices on the local envi...Sandu Bay is located in the East China Sea and is characterized by high-density fish farming and kelp culture. Despite this, little is known about the impacts of these different mariculture practices on the local environment. We investigated the temporal variation in macrobenthos and environmental conditions at three sites in the bay （fish farming site, kelp culture site, and a control site）. We collected water and sediment samples during nine cruises between May 2009 and February 2010. The density of macrobenthos peaked at the fish farming site in July （655 ind./mE） whereas density did not fluctuate as widely at the other two sites. Biomass varied significantly at both the control and kelp culture sites, but had only a single peak at the fish farming site in June （21.90 g/mE）. The dominant species varied throughout the study period at the control and kelp culture sites, whereas a single terebellid species （Lysilla pacifica） dominated the macrobenthos at the fish farming site. The diversity index H＇ increased at the control site beginning in February then decreased after May, whereas H＇ was low at the other sites in December. The mean dissolved oxygen level was highest at the control site （6.59 mg/L） and lowest at the fish farming site （5.54 mg/L）. DO levels were lowest at all sites in summer （July and August）. The sediment acid volatile sulfide content was higher at the fish farming site （1.46 mg/g dry weight） than those at the kelp culture and control sites （1.22 and 0.14 mg/g, respectively）. Our results suggest that mariculture practices have a clear impact on the benthic environment/ community in Sandu Bay.展开更多
The detecting examples using the high density resistivity method, about the evaluation of containing water characteristic from the floor rock and the height of overburden failure, were given. It expresses that the hig...The detecting examples using the high density resistivity method, about the evaluation of containing water characteristic from the floor rock and the height of overburden failure, were given. It expresses that the high density resistivity method has good effect with strong maneuverability and continuous observing section during the prevention and cure for mine water disaster. At the same time, the article pointed out that the study of space data inversion and dynamic watching technology about the high density resistivity method must be enhanced in the future because of special condition of data collecting in mine.展开更多
文摘The electrolysis of water powered by renewable energy sources offers a promising method of"green hydrogen"production,which is considered to be at the heart of future carbon-neutral energy systems.In the past decades,researchers have reported a number of hydrogen evolution reaction(HER)electrocatalysts with activity comparable to that of commercial Pt/C,but most of them are tested within a small current density range,typically no more than 500 mA cm^(-2).To realize the industrial application of hydrogen production from water electrolysis,it is essential to develop high-efficiency HER electrocatalysts at high current density(HCD≥500 mA cm^(-2)).Nevertheless,it remains challenging and significant to rational design HCD electrocatalysts for HER.In this paper,the design strategy of HCD electrocatalysts is discussed,and some HCD electrocatalysts for HER are reviewed in seven categories(alloy,metal oxide,metal hydroxide,metal sulfide/selenide,metal nitride,metal phosphide and other derived electrocatalysts).At the end of this article,we also pro-pose some viewpoints and prospects for the future development and research directions of HCD electrocatalysts for HER.
文摘The present study is focused on a comparative evaluation of landslide disaster using analytical hierarchy process and information value method for hazard assessment in highly tectonic Chamba region in bosom of Himalaya. During study, the information about the causative factors was generated and the landslide hazard zonation maps were delineated using Information Value Method(IV) and Analytical Hierarchy Process(AHP) using Arc GIS(ESRI). For this purpose, the study area was selected in a part of Ravi river catchment along one of the landslide prone Chamba to Bharmour road corridor of National Highway(NH^(-1)54 A) in Himachal Pradesh, India. A numeral landslide triggering geoenvironmental factors i.e. slope, aspect, relative relief, soil, curvature, land use and land cover(LULC), lithology, drainage density, and lineament density were selected for landslide hazard mapping based on landslide inventory. Landslide hazard zonation map was categorized namely "very high hazard, high hazard, medium hazard, low hazard, and very low hazard". The results from these two methods were validated using Area Under Curve(AUC) plots. It is found that hazard zonation map prepared using information value method and analytical hierarchy process methods possess the prediction rate of 78.87% and 75.42%, respectively. Hence, landslide hazardzonation map obtained using information value method is proposed to be more useful for the study area. These final hazard zonation maps can be used by various stakeholders like engineers and administrators for proper maintenance and smooth traffic flow between Chamba and Bharmour cities, which is the only route connecting these tourist places.
基金Supported by the Special Research Fund for the National Non-Profit in East China Sea Fisheries Research Institute (No. 2008M16)
文摘Sandu Bay is located in the East China Sea and is characterized by high-density fish farming and kelp culture. Despite this, little is known about the impacts of these different mariculture practices on the local environment. We investigated the temporal variation in macrobenthos and environmental conditions at three sites in the bay （fish farming site, kelp culture site, and a control site）. We collected water and sediment samples during nine cruises between May 2009 and February 2010. The density of macrobenthos peaked at the fish farming site in July （655 ind./mE） whereas density did not fluctuate as widely at the other two sites. Biomass varied significantly at both the control and kelp culture sites, but had only a single peak at the fish farming site in June （21.90 g/mE）. The dominant species varied throughout the study period at the control and kelp culture sites, whereas a single terebellid species （Lysilla pacifica） dominated the macrobenthos at the fish farming site. The diversity index H＇ increased at the control site beginning in February then decreased after May, whereas H＇ was low at the other sites in December. The mean dissolved oxygen level was highest at the control site （6.59 mg/L） and lowest at the fish farming site （5.54 mg/L）. DO levels were lowest at all sites in summer （July and August）. The sediment acid volatile sulfide content was higher at the fish farming site （1.46 mg/g dry weight） than those at the kelp culture and control sites （1.22 and 0.14 mg/g, respectively）. Our results suggest that mariculture practices have a clear impact on the benthic environment/ community in Sandu Bay.
文摘The detecting examples using the high density resistivity method, about the evaluation of containing water characteristic from the floor rock and the height of overburden failure, were given. It expresses that the high density resistivity method has good effect with strong maneuverability and continuous observing section during the prevention and cure for mine water disaster. At the same time, the article pointed out that the study of space data inversion and dynamic watching technology about the high density resistivity method must be enhanced in the future because of special condition of data collecting in mine.
