In order to improve the transform efficiency of bi-stable energy harvester（BEH）,this paper proposes an advanced bi-stable energy harvester（ABEH）,which is composed of two bi-stable beams coupling through their magn...In order to improve the transform efficiency of bi-stable energy harvester（BEH）,this paper proposes an advanced bi-stable energy harvester（ABEH）,which is composed of two bi-stable beams coupling through their magnets.Theoretical analyzes and simulations for the ABEH are carried out.First,the mathematical model is established and its dynamical equations are derived.The formulas of magnetic force in two directions are given.The potential energy barrier of ABEH is reduced and the snap-through is liable to occur between potential wells.To demonstrate the ABEH＇s advantage in harvesting energy,comparisons between the ABEH and the BEH are carried out for both harmonic and stochastic excitations.Our results reveal that the ABEH＇s inter-well response can be elicited by a low-frequency excitation and the harvester can attain frequent jumping between potential wells at fairly weak random excitations.Thus,it can generate a higher output power.The present findings prove that the ABEH is preferable in harvesting energy and can be optimally designed such that it attains the best harvesting performance.展开更多
The intensity of heat output of coal, the rate of oxygen consumption and the influence function of coal size are tested by the big coal spontaneous combustion experiment unit. The independence of the coefficient of he...The intensity of heat output of coal, the rate of oxygen consumption and the influence function of coal size are tested by the big coal spontaneous combustion experiment unit. The independence of the coefficient of heat convection is studied. And based on the conservation principle of energy and the real conditions, such as coal temperature,air temperature, the geometry size of roadway, air flux, the oxygen concentration in the loose coal around the roadway, the threshold parameters resulting coal spontaneous combustion are put forward, and the index determining the danger zone liable to self ignite are evaluated. Finally, the method determining the danger zone liable to spontaneous ignition around coal roadway at fully mechanized long wall top coal caving face is put forward. Based on the determination method and real conditions in the roadway, the coal around roadway can be divided four zones.展开更多
翻译,继有所感。录之。 一,要自信,但也不要过于自信。 有了相当的外语水平,就要借助资料和工具书,充满信心地翻译。不怕困难,不怕译错。冥思苦想,灵机一动,计上心来,疑团顿释,佳句信笔而成。 在译Carol Singh (C.辛格)的短篇小说Trotsk...翻译,继有所感。录之。 一,要自信,但也不要过于自信。 有了相当的外语水平,就要借助资料和工具书,充满信心地翻译。不怕困难,不怕译错。冥思苦想,灵机一动,计上心来,疑团顿释,佳句信笔而成。 在译Carol Singh (C.辛格)的短篇小说Trotsky’s Other Son(托氏之另子)时,遇到难句: The catch on the door didn’t work,and so it was liable to bang all night ifit was windy—the place was full ofdraughts and if the wind blew outside itblew inside too—keeping the occupantsof the house awake.展开更多
Selenium is an element of great significance in the environment. However, the selenium (Ⅳ) levels in natural water and soil waterextracts are usually lower than the limit of quantitation of available hydride generati...Selenium is an element of great significance in the environment. However, the selenium (Ⅳ) levels in natural water and soil waterextracts are usually lower than the limit of quantitation of available hydride generation atomic absorption methods by 1—2 orders展开更多
Afforestation is helpful to improve soil functions and increase soil organic carbon(SOC)sequestration in semiarid deserts.However,the fine-scale(around a single plant)spatial distribution of SOC and its liable organic...Afforestation is helpful to improve soil functions and increase soil organic carbon(SOC)sequestration in semiarid deserts.However,the fine-scale(around a single plant)spatial distribution of SOC and its liable organic carbon(LOC)fractions after afforestation in semiarid deserts are poorly understood.Pinus sylvestris and Salix psammophila afforested on shifting sandy land(Sland)were selected to quantify fine-scale(at 20,80,150 and 240 cm away from the trees)spatial distribution of SOC and its LOC fractions in the southeast edge of Mu Us Desert,China.The results showed that the afforested S.psammophila and P.sylvestris significantly increased SOC,total nitrogen,dissolved organic carbon,microbial biomass carbon and readily oxidized organic carbon(ROOC).At 20 cm distance,SOC storage of P.sylvestris was 27.21%higher than S.psammophila in 0-100 cm soil layers,and SOC storage of S.psammophila at 80 and 150 cm distances was 5.50%and 5.66%higher than P.sylvestris,respectively.Compared with Sland,SOC storage under S.psammophila and P.sylvestris significantly increased by 94.90%,39.50%,27.10%and 18.50%at 20,80,150 and 240 cm distance,respectively.ROOC accounted for 14.09%and 18.93%of SOC under S.psammophila and P.sylvestris,respectively.Our results suggest that afforestation can promote SOC accumulation at different distances from the plants,and that P.sylvestris allocates more organic matter to the closer soil compared with S.psammophila(<80 cm from the tree).展开更多
英语中有好几个形容词可译成汉语的“易于”、“容易”。这几个形容词在本文中表示的都是一种无意的、不可避免的或习惯上的倾向.它们的意思很相近,大都能互相替换,并且它们的句型也较为一致、即be+adj.+to(do)Sth.现介绍如下: 1.open后...英语中有好几个形容词可译成汉语的“易于”、“容易”。这几个形容词在本文中表示的都是一种无意的、不可避免的或习惯上的倾向.它们的意思很相近,大都能互相替换,并且它们的句型也较为一致、即be+adj.+to(do)Sth.现介绍如下: 1.open后跟to引起的介词短语.例如: His conduct is Open to criticism.他的表现容易遭到别人的批评. His ears are open to rumours.他容易听信谣言. He is so naive that he is open to temptation.他很幼稚。展开更多
as…as 结构是表示比喻的一种最重要的手段,除等比句外,它常常用于主句与从句的主语同一场合,即本体(主语)+谓语+as+喻体(从句)。例如: 1.Work is as necessary for peace of mind as (it isnecessary)for health of body.劳动对于精神...as…as 结构是表示比喻的一种最重要的手段,除等比句外,它常常用于主句与从句的主语同一场合,即本体(主语)+谓语+as+喻体(从句)。例如: 1.Work is as necessary for peace of mind as (it isnecessary)for health of body.劳动对于精神的安宁是必要的,正如劳动对于身体的健康是必要的一样。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
《英语知识》1987年第三期刊出了“英语中表示条件的特殊手段”一文,比较系统地介绍了除条件状语从句以外表示“条件”的“若干形式”。读后很受启示.但又略感不足.在实践中,经常可以遇到一些能够表示“条件”概念的其它从句。其条件意...《英语知识》1987年第三期刊出了“英语中表示条件的特殊手段”一文,比较系统地介绍了除条件状语从句以外表示“条件”的“若干形式”。读后很受启示.但又略感不足.在实践中,经常可以遇到一些能够表示“条件”概念的其它从句。其条件意义有的很明显,有的则比较含蓄.但都比较充分地满足了主句对“条件”的需要。本文拟对某些具有条件意义的非条件从句补充介绍如下: 一、某些定语从句具有条件意义。如: 1.Anyone who begs in a street or public place(=Anyone if he begs in a street or public place)is liable to conviction展开更多
A proposal appealing for harsher punishment legislation for negligent parents and guardians has provoked a long and heated online debate in China. During the 2017 Sessions of the National People＇s Congress and the N...A proposal appealing for harsher punishment legislation for negligent parents and guardians has provoked a long and heated online debate in China. During the 2017 Sessions of the National People＇s Congress and the National Committee of the Chinese People＇s Political Consultative Conference （CPPCC）, Li You and 12 other members of the CPPCC National Committee proposed that parents and guardians who cause bodily harm or death to a child as a result of negligence should be punished by the Criminal Law.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11172234)the Scholarship from China Scholarship Council(Grant No.201506290092)
文摘In order to improve the transform efficiency of bi-stable energy harvester（BEH）,this paper proposes an advanced bi-stable energy harvester（ABEH）,which is composed of two bi-stable beams coupling through their magnets.Theoretical analyzes and simulations for the ABEH are carried out.First,the mathematical model is established and its dynamical equations are derived.The formulas of magnetic force in two directions are given.The potential energy barrier of ABEH is reduced and the snap-through is liable to occur between potential wells.To demonstrate the ABEH＇s advantage in harvesting energy,comparisons between the ABEH and the BEH are carried out for both harmonic and stochastic excitations.Our results reveal that the ABEH＇s inter-well response can be elicited by a low-frequency excitation and the harvester can attain frequent jumping between potential wells at fairly weak random excitations.Thus,it can generate a higher output power.The present findings prove that the ABEH is preferable in harvesting energy and can be optimally designed such that it attains the best harvesting performance.
文摘The intensity of heat output of coal, the rate of oxygen consumption and the influence function of coal size are tested by the big coal spontaneous combustion experiment unit. The independence of the coefficient of heat convection is studied. And based on the conservation principle of energy and the real conditions, such as coal temperature,air temperature, the geometry size of roadway, air flux, the oxygen concentration in the loose coal around the roadway, the threshold parameters resulting coal spontaneous combustion are put forward, and the index determining the danger zone liable to self ignite are evaluated. Finally, the method determining the danger zone liable to spontaneous ignition around coal roadway at fully mechanized long wall top coal caving face is put forward. Based on the determination method and real conditions in the roadway, the coal around roadway can be divided four zones.
文摘翻译,继有所感。录之。 一,要自信,但也不要过于自信。 有了相当的外语水平,就要借助资料和工具书,充满信心地翻译。不怕困难,不怕译错。冥思苦想,灵机一动,计上心来,疑团顿释,佳句信笔而成。 在译Carol Singh (C.辛格)的短篇小说Trotsky’s Other Son(托氏之另子)时,遇到难句: The catch on the door didn’t work,and so it was liable to bang all night ifit was windy—the place was full ofdraughts and if the wind blew outside itblew inside too—keeping the occupantsof the house awake.
文摘Selenium is an element of great significance in the environment. However, the selenium (Ⅳ) levels in natural water and soil waterextracts are usually lower than the limit of quantitation of available hydride generation atomic absorption methods by 1—2 orders
基金supported by the National Natural Science Foundation of China(41877541,41471222).
文摘Afforestation is helpful to improve soil functions and increase soil organic carbon(SOC)sequestration in semiarid deserts.However,the fine-scale(around a single plant)spatial distribution of SOC and its liable organic carbon(LOC)fractions after afforestation in semiarid deserts are poorly understood.Pinus sylvestris and Salix psammophila afforested on shifting sandy land(Sland)were selected to quantify fine-scale(at 20,80,150 and 240 cm away from the trees)spatial distribution of SOC and its LOC fractions in the southeast edge of Mu Us Desert,China.The results showed that the afforested S.psammophila and P.sylvestris significantly increased SOC,total nitrogen,dissolved organic carbon,microbial biomass carbon and readily oxidized organic carbon(ROOC).At 20 cm distance,SOC storage of P.sylvestris was 27.21%higher than S.psammophila in 0-100 cm soil layers,and SOC storage of S.psammophila at 80 and 150 cm distances was 5.50%and 5.66%higher than P.sylvestris,respectively.Compared with Sland,SOC storage under S.psammophila and P.sylvestris significantly increased by 94.90%,39.50%,27.10%and 18.50%at 20,80,150 and 240 cm distance,respectively.ROOC accounted for 14.09%and 18.93%of SOC under S.psammophila and P.sylvestris,respectively.Our results suggest that afforestation can promote SOC accumulation at different distances from the plants,and that P.sylvestris allocates more organic matter to the closer soil compared with S.psammophila(<80 cm from the tree).
文摘英语中有好几个形容词可译成汉语的“易于”、“容易”。这几个形容词在本文中表示的都是一种无意的、不可避免的或习惯上的倾向.它们的意思很相近,大都能互相替换,并且它们的句型也较为一致、即be+adj.+to(do)Sth.现介绍如下: 1.open后跟to引起的介词短语.例如: His conduct is Open to criticism.他的表现容易遭到别人的批评. His ears are open to rumours.他容易听信谣言. He is so naive that he is open to temptation.他很幼稚。
文摘as…as 结构是表示比喻的一种最重要的手段,除等比句外,它常常用于主句与从句的主语同一场合,即本体(主语)+谓语+as+喻体(从句)。例如: 1.Work is as necessary for peace of mind as (it isnecessary)for health of body.劳动对于精神的安宁是必要的,正如劳动对于身体的健康是必要的一样。
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《英语知识》1987年第三期刊出了“英语中表示条件的特殊手段”一文,比较系统地介绍了除条件状语从句以外表示“条件”的“若干形式”。读后很受启示.但又略感不足.在实践中,经常可以遇到一些能够表示“条件”概念的其它从句。其条件意义有的很明显,有的则比较含蓄.但都比较充分地满足了主句对“条件”的需要。本文拟对某些具有条件意义的非条件从句补充介绍如下: 一、某些定语从句具有条件意义。如: 1.Anyone who begs in a street or public place(=Anyone if he begs in a street or public place)is liable to conviction
文摘A proposal appealing for harsher punishment legislation for negligent parents and guardians has provoked a long and heated online debate in China. During the 2017 Sessions of the National People＇s Congress and the National Committee of the Chinese People＇s Political Consultative Conference （CPPCC）, Li You and 12 other members of the CPPCC National Committee proposed that parents and guardians who cause bodily harm or death to a child as a result of negligence should be punished by the Criminal Law.
