调研了美国Class Central网站发布的“2023年250门全球最受欢迎在线课程榜”19门英语写作类MOOC课程。How to Write an Essay被列为250门全球最受欢迎MOOC课程之一,源于其优质的教学设计:世界顶尖大学及其丰富的在线课程经验、优秀师资...调研了美国Class Central网站发布的“2023年250门全球最受欢迎在线课程榜”19门英语写作类MOOC课程。How to Write an Essay被列为250门全球最受欢迎MOOC课程之一,源于其优质的教学设计:世界顶尖大学及其丰富的在线课程经验、优秀师资,教学目标注重培养学习者技能、终身学习理念以及抛锚式教学模式,这对于在线课程建设和教学具有借鉴意义。展开更多
研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac i...研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac id-3β-ol对重组人DNA拓扑异构酶Ⅰ、肝癌细胞BEL-7402和胃腺癌细胞MCG-803的抑制作用,效果显著,IC50值分别为12.0×10-6、6.5×10-6、8.0×10-6g/mL。由V(石油醚)∶V(乙酸乙酯)=20∶1洗脱得到的低极性成分进行了气相色谱-质谱分析,共鉴定60个化合物,其中长链脂肪族化合物,如烷烃、饱和及不饱和羧酸(酯)含量较丰富,占36.16%,萜类和甾体类化合物分别占6.42%和9.28%。展开更多
As a prolific writer of British literature in 20th century,Doris Lessing creates literary works which challenge in both theme and writing style.In her works,the style is distinctive and various,the thought s are deep,...As a prolific writer of British literature in 20th century,Doris Lessing creates literary works which challenge in both theme and writing style.In her works,the style is distinctive and various,the thought s are deep,ideas are sharp and new.This pa per studies women's subject consciousness and their awakenings,and at the same time,intends to explore her transcendence to western feminist criticism.展开更多
言语行为理论是哲学和语言学,特别是语言哲学和语用学的重要理论之一。与言语行为理论有关的诸多著作中,最重要最经典的是奥斯汀的How to Do Things with Words。然而这不是一本易读的书,为此作者分析了该书的脉络,给准备精读该书的读...言语行为理论是哲学和语言学,特别是语言哲学和语用学的重要理论之一。与言语行为理论有关的诸多著作中,最重要最经典的是奥斯汀的How to Do Things with Words。然而这不是一本易读的书,为此作者分析了该书的脉络,给准备精读该书的读者提供一些参考。展开更多
Before his multi-stop visit to Mexico, Argentina, Peru, Colombia and Jamaica in Latin America and the Caribbean （LAC） early February 2018, then U.S. Secretary of State Rex Tillerson released many signals for Latin A...Before his multi-stop visit to Mexico, Argentina, Peru, Colombia and Jamaica in Latin America and the Caribbean （LAC） early February 2018, then U.S. Secretary of State Rex Tillerson released many signals for Latin America. Especially in his remarks at the University of Texas at Austin, he portrayed the presence of China and Russia in LAC as a ＂new imperial power＂ and called on nations of Latin America and the Caribbean to review and reassess China-LAC relations. By identifying China and Russia as critical reference variables for future U.S.- Latin America relations, he obviously went beyond the bilateral level of U.S.- Latin relations and implied the important changes in U.S. policy toward LAC that pressured by growing influence of extra-regional actors in LAC, the United States might strengthen its diplomatic efforts in LAC to maintain and consolidate its dominance in the region.展开更多
文摘调研了美国Class Central网站发布的“2023年250门全球最受欢迎在线课程榜”19门英语写作类MOOC课程。How to Write an Essay被列为250门全球最受欢迎MOOC课程之一,源于其优质的教学设计:世界顶尖大学及其丰富的在线课程经验、优秀师资,教学目标注重培养学习者技能、终身学习理念以及抛锚式教学模式,这对于在线课程建设和教学具有借鉴意义。
文摘研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac id-3β-ol对重组人DNA拓扑异构酶Ⅰ、肝癌细胞BEL-7402和胃腺癌细胞MCG-803的抑制作用,效果显著,IC50值分别为12.0×10-6、6.5×10-6、8.0×10-6g/mL。由V(石油醚)∶V(乙酸乙酯)=20∶1洗脱得到的低极性成分进行了气相色谱-质谱分析,共鉴定60个化合物,其中长链脂肪族化合物,如烷烃、饱和及不饱和羧酸(酯)含量较丰富,占36.16%,萜类和甾体类化合物分别占6.42%和9.28%。
文摘As a prolific writer of British literature in 20th century,Doris Lessing creates literary works which challenge in both theme and writing style.In her works,the style is distinctive and various,the thought s are deep,ideas are sharp and new.This pa per studies women's subject consciousness and their awakenings,and at the same time,intends to explore her transcendence to western feminist criticism.
文摘Before his multi-stop visit to Mexico, Argentina, Peru, Colombia and Jamaica in Latin America and the Caribbean （LAC） early February 2018, then U.S. Secretary of State Rex Tillerson released many signals for Latin America. Especially in his remarks at the University of Texas at Austin, he portrayed the presence of China and Russia in LAC as a ＂new imperial power＂ and called on nations of Latin America and the Caribbean to review and reassess China-LAC relations. By identifying China and Russia as critical reference variables for future U.S.- Latin America relations, he obviously went beyond the bilateral level of U.S.- Latin relations and implied the important changes in U.S. policy toward LAC that pressured by growing influence of extra-regional actors in LAC, the United States might strengthen its diplomatic efforts in LAC to maintain and consolidate its dominance in the region.
