Electrochemical CO_(2) reduction reaction(CO_(2) RR)exhibits remarkable potential in producing valuable chemicals with renewable energy.Operating CO_(2) RR in acidic media is beneficial to solve the issue of low carbo...Electrochemical CO_(2) reduction reaction(CO_(2) RR)exhibits remarkable potential in producing valuable chemicals with renewable energy.Operating CO_(2) RR in acidic media is beneficial to solve the issue of low carbon utilization brought by(bi)carbonate formation at the cathode.Suppressing the competing hydrogen evolution reaction and achieving stable CO_(2) RR performance remains challenging.Herein,we constructed a 3-dimensional Cu(3D-Cu)gas diffusion electrode(GDE)to achieve efficient C_(2)H_(4) production with a partial current density(j C_(2)H_(4))of over 470 mA cm^(2) and a Faradaic efficiency(FE C_(2)H_(4)) of 40%.With pause electrolysis,the decay rate of the j C_(2)H_(4) is only half that of the traditional constant electrolysis.The GDE after constant electrolysis was found to suffer from severe salt formation,leading to the decreased activity and poor stability.展开更多
目的探讨轻中度阿尔茨海默病(Alzheimer s disease,AD)患者的自发言语停顿特征。方法选取简易智力状态检查(minimum mental state examination,MMSE)量表得分10~20分、且病程6个月~5年的轻中度AD患者20例作为AD组,年龄相匹配、认知功能...目的探讨轻中度阿尔茨海默病(Alzheimer s disease,AD)患者的自发言语停顿特征。方法选取简易智力状态检查(minimum mental state examination,MMSE)量表得分10~20分、且病程6个月~5年的轻中度AD患者20例作为AD组,年龄相匹配、认知功能正常受试者25例作为对照组。两组受试者分别进行自发言语表达,选取1 min连续音频,记录停顿总数,按停顿时长分为短时停顿(0.25 s≤t<0.50 s)、中时停顿(0.50 s≤t<0.90 s)、长时停顿(0.90 s≤t<2.00 s)和暂停(>2.00 s),计算各停顿类型均值,比较两组结果,对MMSE得分与停顿数量进行相关回归分析。结果AD组的短时停顿数量显著少于对照组(P<0.05),长时停顿、暂停的数量显著多于对照组(P<0.05);两组间中时停顿、总停顿的数量无统计学差异(P>0.05)。AD组内短时停顿的数量少于中时停顿和长时停顿(P<0.05);AD组中,中时停顿数量对MMSE得分有正向预测作用(β=0.515,P<0.05),暂停数量对MMSE有负向预测作用(β=-0.626,P<0.01)。结论轻中度AD患者在自发言语中产生时间较长停顿的频率更高,产生时间较短停顿的频率较低;认知水平较高的AD患者会产生更多时间较短的停顿,认知水平较低的AD患者会产生更多时间较长的停顿。展开更多
In the college English classroom, pauses function to help students construct speech, promote mutual interaction and lay bare the problems to be looked into. They are critical for the Chinese students speaking English ...In the college English classroom, pauses function to help students construct speech, promote mutual interaction and lay bare the problems to be looked into. They are critical for the Chinese students speaking English by facilitating more appropriate and complex speech in a language they are not as skilled as in their mother tongue. They are also crucial for the teachers in reflecting the cognitive activities of the students, enabling the teachers to understand and track down the speaking trouble on the spot while suggesting places for improvement in their teaching in the future.展开更多
Issues related to the pause of global warming in the last decade are reviewed.It is indicated that:(1) The decade of 1999-2008 is still the warmest of the last 30 years,though the global temperature increment is near ...Issues related to the pause of global warming in the last decade are reviewed.It is indicated that:(1) The decade of 1999-2008 is still the warmest of the last 30 years,though the global temperature increment is near zero;(2) Natural factors such as volcanism,solar radiation,ENSO,and thermohaline circulation can have impact on the inter-annual and inter-decadal variability of global mean temperatures.However,it will not mask the global warming trend for a long time;(3) Temperatures of China continue to increase in 1999-2008 with an increment of 0.4-0.5℃per 10 years.展开更多
<正> Like most July days,it was hot. I stepped into a tiny ice-cream shop to cool off with a chocolate sundae. It was an old-time store, just recently restored—~* with white oak wood-work,little round tables an...<正> Like most July days,it was hot. I stepped into a tiny ice-cream shop to cool off with a chocolate sundae. It was an old-time store, just recently restored—~* with white oak wood-work,little round tables and curlicue chairs.As I entered, 1 caught a glimpse of a very old woman bentover a table near the door.~* Her back was so badly twisted展开更多
基金the financial support from the Research Grants Council of the Hong Kong Special Administrative Region(project no.24304920).
文摘Electrochemical CO_(2) reduction reaction(CO_(2) RR)exhibits remarkable potential in producing valuable chemicals with renewable energy.Operating CO_(2) RR in acidic media is beneficial to solve the issue of low carbon utilization brought by(bi)carbonate formation at the cathode.Suppressing the competing hydrogen evolution reaction and achieving stable CO_(2) RR performance remains challenging.Herein,we constructed a 3-dimensional Cu(3D-Cu)gas diffusion electrode(GDE)to achieve efficient C_(2)H_(4) production with a partial current density(j C_(2)H_(4))of over 470 mA cm^(2) and a Faradaic efficiency(FE C_(2)H_(4)) of 40%.With pause electrolysis,the decay rate of the j C_(2)H_(4) is only half that of the traditional constant electrolysis.The GDE after constant electrolysis was found to suffer from severe salt formation,leading to the decreased activity and poor stability.
文摘In the college English classroom, pauses function to help students construct speech, promote mutual interaction and lay bare the problems to be looked into. They are critical for the Chinese students speaking English by facilitating more appropriate and complex speech in a language they are not as skilled as in their mother tongue. They are also crucial for the teachers in reflecting the cognitive activities of the students, enabling the teachers to understand and track down the speaking trouble on the spot while suggesting places for improvement in their teaching in the future.
基金supported by R&D Special Found for Public Welfare Industry (Meteorology) under Grant No. GYHY200706010
文摘Issues related to the pause of global warming in the last decade are reviewed.It is indicated that:(1) The decade of 1999-2008 is still the warmest of the last 30 years,though the global temperature increment is near zero;(2) Natural factors such as volcanism,solar radiation,ENSO,and thermohaline circulation can have impact on the inter-annual and inter-decadal variability of global mean temperatures.However,it will not mask the global warming trend for a long time;(3) Temperatures of China continue to increase in 1999-2008 with an increment of 0.4-0.5℃per 10 years.
文摘<正> Like most July days,it was hot. I stepped into a tiny ice-cream shop to cool off with a chocolate sundae. It was an old-time store, just recently restored—~* with white oak wood-work,little round tables and curlicue chairs.As I entered, 1 caught a glimpse of a very old woman bentover a table near the door.~* Her back was so badly twisted
