Total concentrations of arsenic, lead, cadmium, mercury, nickel, chromium, and copper in the soils from near a coal mine area in southwest Guizhou, China, were measured to evaluate the level of contamination, and the ...Total concentrations of arsenic, lead, cadmium, mercury, nickel, chromium, and copper in the soils from near a coal mine area in southwest Guizhou, China, were measured to evaluate the level of contamination, and the potential ecological risks posed by the heavy metals were quantitatively estimated. Results reveal that all heavy metals/metalloid exceeded the background values for soil environmental quality of heavy metals in Guizhou area. Geo-accumulation index(I_(geo)) showed that arsenic had the highest contamination level(I_(geo)=4) among the seven heavy metals/metalloid, and the contamination levels of mercury and lead were also relatively high(I_(geo)=3). Pearson correlation and cluster analysis identified that mercury, copper and arsenic had a relationship, and their presence might be mainly related to mining activity, coal and oil combustion, and vehicle emissions. Improved Nemerow index indicated that the overall level of heavy metal contamination in the studied area ranged from moderately–heavily contaminated to heavily contaminated level. Potential ecological risk index(R_I) analysis manifested that the whole ecological risk level ranged from high degree to very high degree(325.30≤R_I≤801.02) in the studied soil samples, and the potential ecological risk factors (E_r^i) of heavy metals/metalloid were as follows: Hg > As > Cd > Pb > Cu > Ni > Cr, and the E_r^i of Hg and As reached very high risk grade.展开更多
The Virginian： A Horseman of the Plains （1902） has been considered as one of the masterpieces of American western novels for its successful depiction of cowboys and local customs, which earns Owen Wister the Father...The Virginian： A Horseman of the Plains （1902） has been considered as one of the masterpieces of American western novels for its successful depiction of cowboys and local customs, which earns Owen Wister the Father of Western fiction. The paper aims to reveal the relationship between The Virginian and its historical context by applying the doctrines of New Historicism： historicity of texts and textuality of history. By historicity of texts, it points out that the work is the emblem of disappearance of western frontier, and it symbolizes the union of the Wild West and the civilized east. By textuality of history, it detects the change of social class, the development of livestock industry and railway, and their influence on the work at the later part of 19th century.展开更多
This study has examined the temporal variation in monthly, seasonal & annual precipitation over the Western Himalayan Region(WHR) and the influence of global teleconnections, like the North Atlantic Oscillation(NA...This study has examined the temporal variation in monthly, seasonal & annual precipitation over the Western Himalayan Region(WHR) and the influence of global teleconnections, like the North Atlantic Oscillation(NAO) and Southern Oscillation(SO) Indices on seasonal & annual precipitation. The Mann–Kendall non-parametric test is applied for trend detection and the Pettitt–Mann–Whitney test is used to detect possible shift. Maximum entropy spectral analysis is applied to find the periodicity in annual & seasonal precipitation. The study shows a non-significant decreasing trend in annual precipitation over WHR for the period 1857-2006. However, in seasonal precipitation, a significant decreasing trend is observed in monsoon and a significant increasing trend in post-monsoon season during the same period. The significant decrease in monsoon precipitation may be due to weakening of its teleconnection with NAO as well as SO Indices mainly during last three decades. It is observed that the probable change of year in annual & monsoon precipitation over WHR is 1979. The study also shows significant periodicities of 2.3-2.9 years and of 3.9-4.7 years in annual & seasonal precipitation over WHR.展开更多
This paper studies how different cultural values and rhetorical traditions may influence students＇ perceptions and understanding of effective ethos in persuasive essays. Fifty Chinese EFL （English as a foreign langu...This paper studies how different cultural values and rhetorical traditions may influence students＇ perceptions and understanding of effective ethos in persuasive essays. Fifty Chinese EFL （English as a foreign language） college students and 50 American college students participated in writing English persuasive essays on the selected topics. The essays were then compared for similarities and differences in the use of rhetorical appeals with a focus on ethos, the credibility, and trustworthiness of an author. The study revealed that participants from both groups established ethos as an important rhetorical tool to persuade the audience to accept their viewpoints. However, they displayed different perceptions of what effective ethos entailed. For Chinese participants, effective ethos seemed to come from using detailed explanations that reflected an author＇s intention to advocate an ethical or moral message based on some Chinese cultural values. But, strong ethos for American participants appeared to mean the use of evidence--facts and personal testimony--to establish the writer＇s trustworthiness. The interpretation of the results from the perspective of different cultural value orientations was also discussed.展开更多
E1 Nino events with an eastern Pacific pattern （EP） and central Pacific pattern （CP） were first separated using rotated empirical orthogonal functions （REOF）. Lead/lag regression and rotated singular value decom...E1 Nino events with an eastern Pacific pattern （EP） and central Pacific pattern （CP） were first separated using rotated empirical orthogonal functions （REOF）. Lead/lag regression and rotated singular value decomposition （RSVD） analyses were then carried out to study the relation between the surface zonal wind （SZW） anomalies and sea surface temperature （SST） anomalies in the tropical Pacific. A possible physical process for the CP E1 Nifio was proposed. For the EP E1 Nino, strong westerly anomalies that spread eastward continuously produce an anomalous ocean zonal convergence zone （ZCZ） centered on about 165°W. This SZW anomaly pattern favors poleward and eastward Sverdrup transport at the equator. For the CP E1Nino, westerly anomalies and the ZCZ are mainly confined to the western Pacific, and easterly anomalies blow in the eastern Pacific. This SZW anomaly pattern restrains poleward and eastward Sverdrup transport at the equator; however, there is an eastward Sverdrup transport at about 5°N, which favors the wanning of the north-eastern tropical Pacific. It is found that the slowness of eastward propagation of subsurface warm water （partly from the downwelling caused by Ekman convergence and the ZCZ） is due to the slowdown of the undercurrent in the central basin, and vertical advection in the central Pacific may be important in the formation and disappearance of the CP E1 Nifio.展开更多
基金Project(21467005)supported by the National Natural Science Foundation of China
文摘Total concentrations of arsenic, lead, cadmium, mercury, nickel, chromium, and copper in the soils from near a coal mine area in southwest Guizhou, China, were measured to evaluate the level of contamination, and the potential ecological risks posed by the heavy metals were quantitatively estimated. Results reveal that all heavy metals/metalloid exceeded the background values for soil environmental quality of heavy metals in Guizhou area. Geo-accumulation index(I_(geo)) showed that arsenic had the highest contamination level(I_(geo)=4) among the seven heavy metals/metalloid, and the contamination levels of mercury and lead were also relatively high(I_(geo)=3). Pearson correlation and cluster analysis identified that mercury, copper and arsenic had a relationship, and their presence might be mainly related to mining activity, coal and oil combustion, and vehicle emissions. Improved Nemerow index indicated that the overall level of heavy metal contamination in the studied area ranged from moderately–heavily contaminated to heavily contaminated level. Potential ecological risk index(R_I) analysis manifested that the whole ecological risk level ranged from high degree to very high degree(325.30≤R_I≤801.02) in the studied soil samples, and the potential ecological risk factors (E_r^i) of heavy metals/metalloid were as follows: Hg > As > Cd > Pb > Cu > Ni > Cr, and the E_r^i of Hg and As reached very high risk grade.
文摘The Virginian： A Horseman of the Plains （1902） has been considered as one of the masterpieces of American western novels for its successful depiction of cowboys and local customs, which earns Owen Wister the Father of Western fiction. The paper aims to reveal the relationship between The Virginian and its historical context by applying the doctrines of New Historicism： historicity of texts and textuality of history. By historicity of texts, it points out that the work is the emblem of disappearance of western frontier, and it symbolizes the union of the Wild West and the civilized east. By textuality of history, it detects the change of social class, the development of livestock industry and railway, and their influence on the work at the later part of 19th century.
文摘This study has examined the temporal variation in monthly, seasonal & annual precipitation over the Western Himalayan Region(WHR) and the influence of global teleconnections, like the North Atlantic Oscillation(NAO) and Southern Oscillation(SO) Indices on seasonal & annual precipitation. The Mann–Kendall non-parametric test is applied for trend detection and the Pettitt–Mann–Whitney test is used to detect possible shift. Maximum entropy spectral analysis is applied to find the periodicity in annual & seasonal precipitation. The study shows a non-significant decreasing trend in annual precipitation over WHR for the period 1857-2006. However, in seasonal precipitation, a significant decreasing trend is observed in monsoon and a significant increasing trend in post-monsoon season during the same period. The significant decrease in monsoon precipitation may be due to weakening of its teleconnection with NAO as well as SO Indices mainly during last three decades. It is observed that the probable change of year in annual & monsoon precipitation over WHR is 1979. The study also shows significant periodicities of 2.3-2.9 years and of 3.9-4.7 years in annual & seasonal precipitation over WHR.
文摘This paper studies how different cultural values and rhetorical traditions may influence students＇ perceptions and understanding of effective ethos in persuasive essays. Fifty Chinese EFL （English as a foreign language） college students and 50 American college students participated in writing English persuasive essays on the selected topics. The essays were then compared for similarities and differences in the use of rhetorical appeals with a focus on ethos, the credibility, and trustworthiness of an author. The study revealed that participants from both groups established ethos as an important rhetorical tool to persuade the audience to accept their viewpoints. However, they displayed different perceptions of what effective ethos entailed. For Chinese participants, effective ethos seemed to come from using detailed explanations that reflected an author＇s intention to advocate an ethical or moral message based on some Chinese cultural values. But, strong ethos for American participants appeared to mean the use of evidence--facts and personal testimony--to establish the writer＇s trustworthiness. The interpretation of the results from the perspective of different cultural value orientations was also discussed.
基金Supported by the National Natural Science Foundation of China(Nos.41076010,41206017)the National Basic Research Program of China(973 Program)(No.2012CB417402)
文摘E1 Nino events with an eastern Pacific pattern （EP） and central Pacific pattern （CP） were first separated using rotated empirical orthogonal functions （REOF）. Lead/lag regression and rotated singular value decomposition （RSVD） analyses were then carried out to study the relation between the surface zonal wind （SZW） anomalies and sea surface temperature （SST） anomalies in the tropical Pacific. A possible physical process for the CP E1 Nifio was proposed. For the EP E1 Nino, strong westerly anomalies that spread eastward continuously produce an anomalous ocean zonal convergence zone （ZCZ） centered on about 165°W. This SZW anomaly pattern favors poleward and eastward Sverdrup transport at the equator. For the CP E1Nino, westerly anomalies and the ZCZ are mainly confined to the western Pacific, and easterly anomalies blow in the eastern Pacific. This SZW anomaly pattern restrains poleward and eastward Sverdrup transport at the equator; however, there is an eastward Sverdrup transport at about 5°N, which favors the wanning of the north-eastern tropical Pacific. It is found that the slowness of eastward propagation of subsurface warm water （partly from the downwelling caused by Ekman convergence and the ZCZ） is due to the slowdown of the undercurrent in the central basin, and vertical advection in the central Pacific may be important in the formation and disappearance of the CP E1 Nifio.
