Long-term analyses of vegetation succession after catastrophic events are of high interest for an improved understanding of succession dynamics. However, in many studies such analyses were restricted to plot-based mea...Long-term analyses of vegetation succession after catastrophic events are of high interest for an improved understanding of succession dynamics. However, in many studies such analyses were restricted to plot-based measurements. Contrarily, spatially continuous observations of succession dynamics over extended areas and timeperiods are sparse. Here, we applied a change vector analysis(CVA) to investigate vegetation succession dynamics at Mount St. Helens after the great volcanic eruption in 1980 using Landsat. We additionally applied a supervised random forest classification using Sentinel-2 data to map the currently prevailing vegetation types. Change vector analysis was performed with the normalized difference vegetation index(NDVI) and the urban index(UI) for three subsequent decades after the eruption as well as for the whole observation time between 1984 and 2016. The influence of topography on the current vegetation distribution was examined by comparing altitude, slope angles and aspect values of vegetation classes derived by the random forest classification. WilcoxRank-Sum test was applied to test for significant differences between topographic properties of the vegetation classes inside and outside of the areas affected by the eruption. For the full time period, a total area of 516 km2 was identified as re-vegetated, whereas the area and magnitude of re-growing vegetation decreased during the three decades and migrated closer to the volcanic crater. Vegetation losses were mainly observed in regions unaffected by the eruption and related mostly to timber harvesting. The vegetation type classification reached a high overall accuracy of approximately 90%. 36 years after the eruption, coniferous and deciduous trees have established at formerly devastated areas dominating with a proportion of 66%, whereas shrubs are more abundant in riparian zones. Sparse vegetation dominates at regions very close to the crater. Elevation was found to have a great influence on the reestablishment and distribution of the vegetation classes within the devastated areas showing in almost all cases significant differences in altitude distribution. Slope was less important for the different classes-only representing significantly higher values for meadows, whereas aspect seems to have no notable influence on the reestablishment of vegetation at Mount St. Helens. We conclude that major vegetation succession dynamics after catastrophic events can be assessed and characterized over large areas from freely available remote sensing data and hence contribute to an improved understanding of succession dynamics.展开更多
Benedict is an award-winning novelist and non-fiction writer specializing in social injustice.Her non-fiction book The Lonely Soldier reflects the impact of war on violence against women.Female soldiers are always the...Benedict is an award-winning novelist and non-fiction writer specializing in social injustice.Her non-fiction book The Lonely Soldier reflects the impact of war on violence against women.Female soldiers are always the victims of violence,before,during,and after serving in the Iraq War.This thesis aims to explore their trauma and illuminate the book’s meaning.展开更多
The deterioration of the environment caused by climate change has been entangled with other factors to wane people’s desire for having children.This paper takes two climate short stories,The Smog Society by the Chine...The deterioration of the environment caused by climate change has been entangled with other factors to wane people’s desire for having children.This paper takes two climate short stories,The Smog Society by the Chinese SF author Chen Qiufan and Diary of an Interesting Year by the British writer Helen Simpson as case studies,comparing the writing of the climate change induced fertility anxiety in the two stories from both the individual and community perspectives.By associating the textual analysis with the social reality about fertility rate in China and Britain,the paper explores performance and coping methods of fertility anxiety in the face of climate crisis,aimed at providing possible solutions for the sustainable development of population.展开更多
海伦·朗基诺（Helen E.Longino）,女,国际知名科学哲学家。1973年在约翰·霍普金斯大学获哲学博士学位。现任职于美国斯坦福大学哲学系（2005—至今）,C.I.Lewis教授。她曾经担任斯坦福大学哲学系主任（2008.09—2012.08）,美...海伦·朗基诺（Helen E.Longino）,女,国际知名科学哲学家。1973年在约翰·霍普金斯大学获哲学博士学位。现任职于美国斯坦福大学哲学系（2005—至今）,C.I.Lewis教授。她曾经担任斯坦福大学哲学系主任（2008.09—2012.08）,美国科学哲学学会主席（2013.01—2014.11）。主要研究领域为：科学哲学、社会认识论和女性主义哲学。代表作有：《作为社会知识的科学》（Science as Social Knowledge,展开更多
The 2000 km Columbia River is the longest river in the Pacific Northwest region of North America. It starts in British Columbia, Canada and flows through the states of Oregon and Washington before discharging into Pac...The 2000 km Columbia River is the longest river in the Pacific Northwest region of North America. It starts in British Columbia, Canada and flows through the states of Oregon and Washington before discharging into Pacific Ocean near Cape Disappointment. The mouth of the Columbia River is a deep water harbor and 180 km of the river can be accessed by navigation. Based on flow volume, the river is the 4th largest river in the United States. The headwaters and approximately 800 km of the Columbia River lie in Canada. Columbia Lake and the Columbia Wetlands are located in British Columbia and are the headwaters of the Columbia River. The lake has an elevation of 820 m above sea level and drains to the Pacific Ocean near Astoria, Oregon. The Ocean tides flow up river to Portland, Oregon. This paper highlights how the geological and landscape resources of the Columbia River and tributaries watershed contributed to the economic development of this historically rich region of North America. The Columbia River is one of the most biologically diverse freshwater systems in the United States. The Columbia River system with trails and cruise ships was designed to increase use of the Columbia River, to promote recreational tourism, and to create a generation of people who are willing to protect and provide environmental stewardship of the river basin resources.展开更多
【问】[392]still修饰形容词/副词比较级时,是否放在其前或后均可? 【答】1.如果被修饰的形容词比较级作表语或宾语补足语,still的位置可前可后,如: (1)Tom is tall,but Mary is taller still/still taller.still easier. 2. 如果形容...【问】[392]still修饰形容词/副词比较级时,是否放在其前或后均可? 【答】1.如果被修饰的形容词比较级作表语或宾语补足语,still的位置可前可后,如: (1)Tom is tall,but Mary is taller still/still taller.still easier. 2. 如果形容词比较级作定语,后面跟着名词。展开更多
The Beta-Atla-Themis(BAT)region on Venus is characterized by large volcanic rises,major rift zones(chasmata),radiating,linear,and circumferential grabenfissure systems,and coronae.Its most prominent features
China had made great achievements in sustainable development, and China’s experience can be shared with other developing countries, said Helen Clark,Administrator of the United Nations Development Program (UNDP).
1.to make sure:确信,证实(也可以说 tomakecertain,意思是 to be sure,to ascertain)。如:Please make sure that you tum off the radio beforeyou go out.Could you make certain of the time?I don’t wantto miss that.2.now and t...1.to make sure:确信,证实(也可以说 tomakecertain,意思是 to be sure,to ascertain)。如:Please make sure that you tum off the radio beforeyou go out.Could you make certain of the time?I don’t wantto miss that.2.now and then:偶尔,不时,有时(也可以说 now and again,at times,from time to time,off andon,once in a while)。now and then 和 once in a展开更多
用表示器官的词填空。例:Two heads are better than one.(proverb)1.The patient has one __ in the grave.2.Xiao Wang,please give me a__.3.Tom has fallen in love with Helen.He loves her from__
文摘Long-term analyses of vegetation succession after catastrophic events are of high interest for an improved understanding of succession dynamics. However, in many studies such analyses were restricted to plot-based measurements. Contrarily, spatially continuous observations of succession dynamics over extended areas and timeperiods are sparse. Here, we applied a change vector analysis(CVA) to investigate vegetation succession dynamics at Mount St. Helens after the great volcanic eruption in 1980 using Landsat. We additionally applied a supervised random forest classification using Sentinel-2 data to map the currently prevailing vegetation types. Change vector analysis was performed with the normalized difference vegetation index(NDVI) and the urban index(UI) for three subsequent decades after the eruption as well as for the whole observation time between 1984 and 2016. The influence of topography on the current vegetation distribution was examined by comparing altitude, slope angles and aspect values of vegetation classes derived by the random forest classification. WilcoxRank-Sum test was applied to test for significant differences between topographic properties of the vegetation classes inside and outside of the areas affected by the eruption. For the full time period, a total area of 516 km2 was identified as re-vegetated, whereas the area and magnitude of re-growing vegetation decreased during the three decades and migrated closer to the volcanic crater. Vegetation losses were mainly observed in regions unaffected by the eruption and related mostly to timber harvesting. The vegetation type classification reached a high overall accuracy of approximately 90%. 36 years after the eruption, coniferous and deciduous trees have established at formerly devastated areas dominating with a proportion of 66%, whereas shrubs are more abundant in riparian zones. Sparse vegetation dominates at regions very close to the crater. Elevation was found to have a great influence on the reestablishment and distribution of the vegetation classes within the devastated areas showing in almost all cases significant differences in altitude distribution. Slope was less important for the different classes-only representing significantly higher values for meadows, whereas aspect seems to have no notable influence on the reestablishment of vegetation at Mount St. Helens. We conclude that major vegetation succession dynamics after catastrophic events can be assessed and characterized over large areas from freely available remote sensing data and hence contribute to an improved understanding of succession dynamics.
文摘Benedict is an award-winning novelist and non-fiction writer specializing in social injustice.Her non-fiction book The Lonely Soldier reflects the impact of war on violence against women.Female soldiers are always the victims of violence,before,during,and after serving in the Iraq War.This thesis aims to explore their trauma and illuminate the book’s meaning.
基金This paper is a periodic achievement of the 2021 Shanghai college Students’innovation and entrepreneurship project“Cross-cultural Comparative Study of Short Climate Fictions”(Project No.SH2021148),and is supported by the scientific research project course“Research on American Climate Fictions in the 21st Century”of University of Shanghai for Science and Technology.
文摘The deterioration of the environment caused by climate change has been entangled with other factors to wane people’s desire for having children.This paper takes two climate short stories,The Smog Society by the Chinese SF author Chen Qiufan and Diary of an Interesting Year by the British writer Helen Simpson as case studies,comparing the writing of the climate change induced fertility anxiety in the two stories from both the individual and community perspectives.By associating the textual analysis with the social reality about fertility rate in China and Britain,the paper explores performance and coping methods of fertility anxiety in the face of climate crisis,aimed at providing possible solutions for the sustainable development of population.
文摘海伦·朗基诺（Helen E.Longino）,女,国际知名科学哲学家。1973年在约翰·霍普金斯大学获哲学博士学位。现任职于美国斯坦福大学哲学系（2005—至今）,C.I.Lewis教授。她曾经担任斯坦福大学哲学系主任（2008.09—2012.08）,美国科学哲学学会主席（2013.01—2014.11）。主要研究领域为：科学哲学、社会认识论和女性主义哲学。代表作有：《作为社会知识的科学》（Science as Social Knowledge,
文摘The 2000 km Columbia River is the longest river in the Pacific Northwest region of North America. It starts in British Columbia, Canada and flows through the states of Oregon and Washington before discharging into Pacific Ocean near Cape Disappointment. The mouth of the Columbia River is a deep water harbor and 180 km of the river can be accessed by navigation. Based on flow volume, the river is the 4th largest river in the United States. The headwaters and approximately 800 km of the Columbia River lie in Canada. Columbia Lake and the Columbia Wetlands are located in British Columbia and are the headwaters of the Columbia River. The lake has an elevation of 820 m above sea level and drains to the Pacific Ocean near Astoria, Oregon. The Ocean tides flow up river to Portland, Oregon. This paper highlights how the geological and landscape resources of the Columbia River and tributaries watershed contributed to the economic development of this historically rich region of North America. The Columbia River is one of the most biologically diverse freshwater systems in the United States. The Columbia River system with trails and cruise ships was designed to increase use of the Columbia River, to promote recreational tourism, and to create a generation of people who are willing to protect and provide environmental stewardship of the river basin resources.
文摘【问】[392]still修饰形容词/副词比较级时,是否放在其前或后均可? 【答】1.如果被修饰的形容词比较级作表语或宾语补足语,still的位置可前可后,如: (1)Tom is tall,but Mary is taller still/still taller.still easier. 2. 如果形容词比较级作定语,后面跟着名词。
文摘The Beta-Atla-Themis(BAT)region on Venus is characterized by large volcanic rises,major rift zones(chasmata),radiating,linear,and circumferential grabenfissure systems,and coronae.Its most prominent features
文摘China had made great achievements in sustainable development, and China’s experience can be shared with other developing countries, said Helen Clark,Administrator of the United Nations Development Program (UNDP).
文摘1.to make sure:确信,证实(也可以说 tomakecertain,意思是 to be sure,to ascertain)。如:Please make sure that you tum off the radio beforeyou go out.Could you make certain of the time?I don’t wantto miss that.2.now and then:偶尔,不时,有时(也可以说 now and again,at times,from time to time,off andon,once in a while)。now and then 和 once in a
文摘用表示器官的词填空。例:Two heads are better than one.(proverb)1.The patient has one __ in the grave.2.Xiao Wang,please give me a__.3.Tom has fallen in love with Helen.He loves her from__
