To calculate the aerodynamics of flapping-wing micro air vehicle（MAV） with the high efficiency and the engineering-oriented accuracy,an improved unsteady vortex lattice method （UVLM） for MAV is proposed. The metho...To calculate the aerodynamics of flapping-wing micro air vehicle（MAV） with the high efficiency and the engineering-oriented accuracy,an improved unsteady vortex lattice method （UVLM） for MAV is proposed. The method considers the influence of instantaneous wing deforming in flapping,as well as the induced drag,additionally models the stretching and the dissipation of vortex rings,and can present the aerodynamics status on the wing surface. An implementation of the method is developed. Moreover,the results and the efficiency of the proposed method are verified by CFD methods. Considering the less time cost of UVLM,for application of UVLM in the MAV optimization,the influence of wake vortex ignoring time saving and precision is studied. Results show that saving in CPU time with wake vortex ignoring the appropriate distance is considerable while the precision is not significantly reduced. It indicates the potential value of UVLM in the optimization of MAV design.展开更多
Traditionally,Brett from Hemingway’s The Sun Also Rises is criticized for her embodiment of various decaying indications.In appearance,that is the very conclusion a plain reader can draw from the text.But taking the ...Traditionally,Brett from Hemingway’s The Sun Also Rises is criticized for her embodiment of various decaying indications.In appearance,that is the very conclusion a plain reader can draw from the text.But taking the specific historic and literal background into the inter-textual reading,a critic reader will surely discern a series of qualities in Brett to argue for her inner innocent self which was so damaged by the reality.The author implies his"iceberg"to the effect that most readers are liable to ignore or neglect.Close reading reveals the deep-rooted sympathy in the author’s inner heart.This sympathy is not only directed to Brett,but all those in tragedies in that historic era and this sympathy later functions to highlight women’s values in the author’s viewpoint.展开更多
at与某些动词搭配时,往往表示各种不同方式和含义的“目视”。现分述如下: 1.wink at 1)(give a glance or sign to sb.)使眼色,眨眼示意 Father winked at Dick as a sign for him to keep still. 父亲向狄克霎眼示意,叫他不要动。 2)(...at与某些动词搭配时,往往表示各种不同方式和含义的“目视”。现分述如下: 1.wink at 1)(give a glance or sign to sb.)使眼色,眨眼示意 Father winked at Dick as a sign for him to keep still. 父亲向狄克霎眼示意,叫他不要动。 2)(deliberetely ignore,pretend not to see) 有意忽视,假装不见。 Can you wink at what they are doing? 你能够对他们的所作所为视而不见吗?展开更多
‘Friends,Romans,countrymen,lendme your ears’,said Mark Anthony in JuliusCaesar when he wanted people to listen.When you are“‘all ears’,you are listeningattentively.If you‘don’t believe yourears’,you’re incred...‘Friends,Romans,countrymen,lendme your ears’,said Mark Anthony in JuliusCaesar when he wanted people to listen.When you are“‘all ears’,you are listeningattentively.If you‘don’t believe yourears’,you’re incredulous at what you hear.When the information embarrasses you,it“‘makes your ears burn’,Better,in thiscase,to ignore the comments and‘turn adeaf ear’,or pretend not to hear,by lettingthe news‘go in one ear and out the oth-er’.展开更多
I’m not sure how he got to my clinic.He didn’t look oldenough to drive,although his child’s body had begun tobroaden and he moved with the heavy grace of young man-hood.His face was direct and open.When I walked in...I’m not sure how he got to my clinic.He didn’t look oldenough to drive,although his child’s body had begun tobroaden and he moved with the heavy grace of young man-hood.His face was direct and open.When I walked into the waiting room,he was展开更多
We have studied the propagation dynamics of ultrafast electron pulses by using an improved mean-field model, in which the propagation of the electron pulses across the boundary of the acceleration region is explicitly...We have studied the propagation dynamics of ultrafast electron pulses by using an improved mean-field model, in which the propagation of the electron pulses across the boundary of the acceleration region is explicitly considered. A large decrease in the speed spread of the electron pulses（we called “boundary kick”） is observed and properly treated leading to a significant improvement in the simulation accuracy, particularly when the density of electrons is very large. We show that our method is consistent with the simulation by the N-particle method, while others can introduce factorial error.展开更多
QUESTION:Isretention2 in thesame grade everadvisable for a childwho is not a*latebloomer3.How aboutthe slow learner?DR.DOBSON:There are some stu—dents who can profitfrom a second year atthe same grade level,and many who
在高二英语课本中相继出现了 affect 和 effect。这两个词虽说都有“影响”之意,但词性不同,而且用法也各异。此外,由于它们发音相似而易于混淆。现辨异如下:一、affect 只用怍动词。使用时常有以下几个意义。1.表示“影响”,“对……有...在高二英语课本中相继出现了 affect 和 effect。这两个词虽说都有“影响”之意,但词性不同,而且用法也各异。此外,由于它们发音相似而易于混淆。现辨异如下:一、affect 只用怍动词。使用时常有以下几个意义。1.表示“影响”,“对……有(产生)影响”。例如;Smoking affects health.吸烟影响健康。The war and the sufferinu that it caused affected him greatly.(SB Ⅱ p.105)这场战争及其所造成的苦难对他影响很大。展开更多
所谓平衡(balance),是就语句中两个以上的同等结构的运用而言的,例如:Now I do what I want——avocado in the salad,garlic in the lamb.现在我想做什么就做什么——沙拉里放鳄梨啰,羊肉里加大蒜啰。这句话中的介宾短语对仗工整,语调...所谓平衡(balance),是就语句中两个以上的同等结构的运用而言的,例如:Now I do what I want——avocado in the salad,garlic in the lamb.现在我想做什么就做什么——沙拉里放鳄梨啰,羊肉里加大蒜啰。这句话中的介宾短语对仗工整,语调流畅,表现出均衡美的特点。然而,展开更多
When referring to job recruitment,the most pops as always belong to the fields with high-technology and difficulties,such as finance,IT, biological technology,environment and so on,so that those people with some myste...When referring to job recruitment,the most pops as always belong to the fields with high-technology and difficulties,such as finance,IT, biological technology,environment and so on,so that those people with some mysterious or complicated jobs,like actuary,investment analyst,ocean scholar,would gain more admirers and respect from the society.Whereas,as for some traditional occupations,the symbol of labor-intensive makes society ignore the creativity and talent of the designers,which is also needed to be recognized and admitted.展开更多
Research on Second Language Classroom Processes The second language classroom has long been a centre of research interest. In recent years, traditional, grammarbased instructions has been widely criticized as being in...Research on Second Language Classroom Processes The second language classroom has long been a centre of research interest. In recent years, traditional, grammarbased instructions has been widely criticized as being ineffective. Methodologists of many persuasions have emphasized the limitations of traditional approaches to language teaching, where repetitive imitations, memorization of展开更多
在当今全球超过50起暴力冲突中,近30万的孩童成为了士兵。我们从来没有审视过在一个孩子眼中,残酷的战争会是什么模样。A Long Way Gone就是一个名叫Ishmael Beah的塞拉利昂男孩的战争回忆录。下面这一段是作者回忆儿时对战争的印象,有...在当今全球超过50起暴力冲突中,近30万的孩童成为了士兵。我们从来没有审视过在一个孩子眼中,残酷的战争会是什么模样。A Long Way Gone就是一个名叫Ishmael Beah的塞拉利昂男孩的战争回忆录。下面这一段是作者回忆儿时对战争的印象,有一种事不关己的感觉,为下文的参加战争到认识战争的描述作铺垫,更加能映衬出战争的残酷和人们的悲痛。展开更多
There are more and more exchanges between countries as we go global.Cross-cultural knowledge is coming to play a vital role in effective communications between people of different nations.As a language facilitator,lea...There are more and more exchanges between countries as we go global.Cross-cultural knowledge is coming to play a vital role in effective communications between people of different nations.As a language facilitator,learning from my own experience offers me a deeper insight into another culture and custom,thus shedding light on proper and well-accepted communications.展开更多
基金Supported by the Aviation Science Foundation of China (2007ZA56001)the National Natural Science Foundation of China(50865009)~~
文摘To calculate the aerodynamics of flapping-wing micro air vehicle（MAV） with the high efficiency and the engineering-oriented accuracy,an improved unsteady vortex lattice method （UVLM） for MAV is proposed. The method considers the influence of instantaneous wing deforming in flapping,as well as the induced drag,additionally models the stretching and the dissipation of vortex rings,and can present the aerodynamics status on the wing surface. An implementation of the method is developed. Moreover,the results and the efficiency of the proposed method are verified by CFD methods. Considering the less time cost of UVLM,for application of UVLM in the MAV optimization,the influence of wake vortex ignoring time saving and precision is studied. Results show that saving in CPU time with wake vortex ignoring the appropriate distance is considerable while the precision is not significantly reduced. It indicates the potential value of UVLM in the optimization of MAV design.
文摘Traditionally,Brett from Hemingway’s The Sun Also Rises is criticized for her embodiment of various decaying indications.In appearance,that is the very conclusion a plain reader can draw from the text.But taking the specific historic and literal background into the inter-textual reading,a critic reader will surely discern a series of qualities in Brett to argue for her inner innocent self which was so damaged by the reality.The author implies his"iceberg"to the effect that most readers are liable to ignore or neglect.Close reading reveals the deep-rooted sympathy in the author’s inner heart.This sympathy is not only directed to Brett,but all those in tragedies in that historic era and this sympathy later functions to highlight women’s values in the author’s viewpoint.
文摘at与某些动词搭配时,往往表示各种不同方式和含义的“目视”。现分述如下: 1.wink at 1)(give a glance or sign to sb.)使眼色,眨眼示意 Father winked at Dick as a sign for him to keep still. 父亲向狄克霎眼示意,叫他不要动。 2)(deliberetely ignore,pretend not to see) 有意忽视,假装不见。 Can you wink at what they are doing? 你能够对他们的所作所为视而不见吗?
文摘‘Friends,Romans,countrymen,lendme your ears’,said Mark Anthony in JuliusCaesar when he wanted people to listen.When you are“‘all ears’,you are listeningattentively.If you‘don’t believe yourears’,you’re incredulous at what you hear.When the information embarrasses you,it“‘makes your ears burn’,Better,in thiscase,to ignore the comments and‘turn adeaf ear’,or pretend not to hear,by lettingthe news‘go in one ear and out the oth-er’.
文摘I’m not sure how he got to my clinic.He didn’t look oldenough to drive,although his child’s body had begun tobroaden and he moved with the heavy grace of young man-hood.His face was direct and open.When I walked into the waiting room,he was
基金Project supported by the National Basic Research Program of China(Grant No.2013CBA01501)the Science Challenge Program and the Strategic Pilot Project of the Chinese Academy of Sciences
文摘We have studied the propagation dynamics of ultrafast electron pulses by using an improved mean-field model, in which the propagation of the electron pulses across the boundary of the acceleration region is explicitly considered. A large decrease in the speed spread of the electron pulses（we called “boundary kick”） is observed and properly treated leading to a significant improvement in the simulation accuracy, particularly when the density of electrons is very large. We show that our method is consistent with the simulation by the N-particle method, while others can introduce factorial error.
文摘QUESTION:Isretention2 in thesame grade everadvisable for a childwho is not a*latebloomer3.How aboutthe slow learner?DR.DOBSON:There are some stu—dents who can profitfrom a second year atthe same grade level,and many who
文摘在高二英语课本中相继出现了 affect 和 effect。这两个词虽说都有“影响”之意,但词性不同,而且用法也各异。此外,由于它们发音相似而易于混淆。现辨异如下:一、affect 只用怍动词。使用时常有以下几个意义。1.表示“影响”,“对……有(产生)影响”。例如;Smoking affects health.吸烟影响健康。The war and the sufferinu that it caused affected him greatly.(SB Ⅱ p.105)这场战争及其所造成的苦难对他影响很大。
文摘所谓平衡(balance),是就语句中两个以上的同等结构的运用而言的,例如:Now I do what I want——avocado in the salad,garlic in the lamb.现在我想做什么就做什么——沙拉里放鳄梨啰,羊肉里加大蒜啰。这句话中的介宾短语对仗工整,语调流畅,表现出均衡美的特点。然而,
文摘When referring to job recruitment,the most pops as always belong to the fields with high-technology and difficulties,such as finance,IT, biological technology,environment and so on,so that those people with some mysterious or complicated jobs,like actuary,investment analyst,ocean scholar,would gain more admirers and respect from the society.Whereas,as for some traditional occupations,the symbol of labor-intensive makes society ignore the creativity and talent of the designers,which is also needed to be recognized and admitted.
文摘Research on Second Language Classroom Processes The second language classroom has long been a centre of research interest. In recent years, traditional, grammarbased instructions has been widely criticized as being ineffective. Methodologists of many persuasions have emphasized the limitations of traditional approaches to language teaching, where repetitive imitations, memorization of
文摘在当今全球超过50起暴力冲突中,近30万的孩童成为了士兵。我们从来没有审视过在一个孩子眼中,残酷的战争会是什么模样。A Long Way Gone就是一个名叫Ishmael Beah的塞拉利昂男孩的战争回忆录。下面这一段是作者回忆儿时对战争的印象,有一种事不关己的感觉,为下文的参加战争到认识战争的描述作铺垫,更加能映衬出战争的残酷和人们的悲痛。
文摘There are more and more exchanges between countries as we go global.Cross-cultural knowledge is coming to play a vital role in effective communications between people of different nations.As a language facilitator,learning from my own experience offers me a deeper insight into another culture and custom,thus shedding light on proper and well-accepted communications.
