Based on vibration analysis, single-layered graphene sheet （SLGS） with multiple attached nanoparticles is developed as nanoscale mass sensor in thermal environments. Graphene sensors are assumed to be in simplysuppo...Based on vibration analysis, single-layered graphene sheet （SLGS） with multiple attached nanoparticles is developed as nanoscale mass sensor in thermal environments. Graphene sensors are assumed to be in simplysupported configuration. Based on the nonlocal plate the- ory which incorporates size effects into the classical theory, closed-form expressions lot the frequencies and relative fre- quency shills of SLGS-based mass sensor are derived using the Galerkin method. The suggested model is justified by a good agreement between the results given by the present model and available data in literature. The effects of tem- perature difference, nonlocal parameter, the location of the nanoparticle and the number of nanoparticles on the relative frequency shift of the mass sensor are also elucidated. The obtained results show that the sensitivity of the SLGS- based mass sensor increases with increasing temperature difference.展开更多
This study attempted to examine the importance of storeenvironment in affecting consumers’store choice deci-sion;the relative importance among the three environ-mental factors;and consumers’expectations on store en-...This study attempted to examine the importance of storeenvironment in affecting consumers’store choice deci-sion;the relative importance among the three environ-mental factors;and consumers’expectations on store en-vironment for the casual-wear chain stores in HongKong.Julie Baker’s Three-category framework onstore environments namely ambient,design and socialfactors was adopted for investigation.The results indi-cated that the store environment was important in affect-ing consumers’selection of store for shopping.It alsorevealed that social factor was perceived relatively im-portant than ambient and design factors.Nine store ex-pectation dimensions were categorised and the resultdemonstrated that most respondents were concerned onthe social aspect in their expectation of having a satisfy-ing store environment.展开更多
The main objective of this paper is to evaluate the seismic response of buildings of typical reinforced concrete frames when concrete starts to deteriorate gradually and to make a comparison between the base shear and...The main objective of this paper is to evaluate the seismic response of buildings of typical reinforced concrete frames when concrete starts to deteriorate gradually and to make a comparison between the base shear and the displacement at different stages of earthquake loading. Typical 5, 15, 20 and 30-storey reinforced concrete frames have been designed for seismicity according to the recently adopted seismic code in Abu Dhabi, ACI 318-08/IBC 2009 code. A pushover analysis has been performed to these four buildings by using SAP 2000. Twenty-four models have been created (6 models for each building) by decreasing the concrete strength gradually from 4000 psi (281 kg/cm<sup>2</sup>) to 1500 psi (105 kg/cm<sup>2</sup>). This is to simulate the effect of harsh environment on the strength of concrete in existing buildings.展开更多
The new nanosolid superacid catalyst SO42-/TiO2 is compounded with nanometer chemical technology. This catalyst SO42-/TiO2 has good catalytic effects on esterificational reactions of ethylic acid and ethyl alcohol. It...The new nanosolid superacid catalyst SO42-/TiO2 is compounded with nanometer chemical technology. This catalyst SO42-/TiO2 has good catalytic effects on esterificational reactions of ethylic acid and ethyl alcohol. It has many other advantages such as strong water proof quality, being able to be used repeatedly, being easy to be reclaimed, non corroding, non polluting. So it is a green industrial catalyst which is helpful to the environment and possesses wide prospect of applications. The crystallo process, specific surface area and sulphur content of the SO42-/TiO2 system have been studied with the method of XRD, XPS and the chemical analysis, the result of which indicates that catalytic activity and acid strength of SO42-/TiO2 is affected by the H2SO4 saturant concentration, baking temperature, precipitating condition, specific surface area and sulphur content. The best preparation conditions of SO42-/TiO2 are: ageing temperature at 0℃, 0.5mol·L-1 of H2SO4 concentration, baking temperature at 500℃and 3 hours of baking time.展开更多
In my ten-yeat experience of tenching English as major in college , I feel that students experience more difficulties in listening lessons than in other lessons. What, then, prevents students from achieving success in...In my ten-yeat experience of tenching English as major in college , I feel that students experience more difficulties in listening lessons than in other lessons. What, then, prevents students from achieving success in the listening class? I suggest that anxiety is one of the major factors, which interferes with students listening comprehension. And I would agree with writers such as Gardner and Horwitz et al. (1991)that anxiety may impede learner’s ability to perform successfully in all aspects of learning a foreign language. I feet it is particularly significant for listening.展开更多
To improve the durability of underwater rotating products,the corrosion characteristics in harsh marine environment were evaluated through various electrochemical experiments on the Al2O3-3TiO2 and CoNiCrAlY coating l...To improve the durability of underwater rotating products,the corrosion characteristics in harsh marine environment were evaluated through various electrochemical experiments on the Al2O3-3TiO2 and CoNiCrAlY coating layers by atmospheric pressure plasma spray coating process.By evaluating the corrosion resistance of these materials,their applicability to environmentally friendly power generation equipment such as blades of tidal current turbines was examined.According to the Tafel analysis for micro-areas including the coating layer,the coating/metal interlayer and the base metal,the Al2O3-3TiO2 coating layer and the CoNiCrAlY coating layer show markedly lower corrosion current density than the base metal.The corrosion current density of the CoNiCrAlY coating layer (9.75316×10-8A/cm2) is about 1.6 times more than that of the Al2O3-3TiO2 coating layer (6.13139×10-8A/cm2).展开更多
作为面向互联网资源共享的虚拟计算环境的实例,iVCE(Internet based virtual computing environment)for Memory致力于解决广域分布的内存资源的共享与综合利用问题.由于内存资源的特殊性,传统的资源管理方法很难适用.以iVCE for Memor...作为面向互联网资源共享的虚拟计算环境的实例,iVCE(Internet based virtual computing environment)for Memory致力于解决广域分布的内存资源的共享与综合利用问题.由于内存资源的特殊性,传统的资源管理方法很难适用.以iVCE for Memory作为背景,提出一种基于聚类的虚拟计算环境资源聚合方法,有效降低了资源聚合的问题规模;借鉴物理学中的力场和势能理论,建立了实现资源聚合的基本模型和力场-势能模型以及相应的分布式算法;通过基于真实网络拓扑的模拟,对两种模型和算法分别进行了评估和验证.展开更多
文摘Based on vibration analysis, single-layered graphene sheet （SLGS） with multiple attached nanoparticles is developed as nanoscale mass sensor in thermal environments. Graphene sensors are assumed to be in simplysupported configuration. Based on the nonlocal plate the- ory which incorporates size effects into the classical theory, closed-form expressions lot the frequencies and relative fre- quency shills of SLGS-based mass sensor are derived using the Galerkin method. The suggested model is justified by a good agreement between the results given by the present model and available data in literature. The effects of tem- perature difference, nonlocal parameter, the location of the nanoparticle and the number of nanoparticles on the relative frequency shift of the mass sensor are also elucidated. The obtained results show that the sensitivity of the SLGS- based mass sensor increases with increasing temperature difference.
文摘This study attempted to examine the importance of storeenvironment in affecting consumers’store choice deci-sion;the relative importance among the three environ-mental factors;and consumers’expectations on store en-vironment for the casual-wear chain stores in HongKong.Julie Baker’s Three-category framework onstore environments namely ambient,design and socialfactors was adopted for investigation.The results indi-cated that the store environment was important in affect-ing consumers’selection of store for shopping.It alsorevealed that social factor was perceived relatively im-portant than ambient and design factors.Nine store ex-pectation dimensions were categorised and the resultdemonstrated that most respondents were concerned onthe social aspect in their expectation of having a satisfy-ing store environment.
文摘The main objective of this paper is to evaluate the seismic response of buildings of typical reinforced concrete frames when concrete starts to deteriorate gradually and to make a comparison between the base shear and the displacement at different stages of earthquake loading. Typical 5, 15, 20 and 30-storey reinforced concrete frames have been designed for seismicity according to the recently adopted seismic code in Abu Dhabi, ACI 318-08/IBC 2009 code. A pushover analysis has been performed to these four buildings by using SAP 2000. Twenty-four models have been created (6 models for each building) by decreasing the concrete strength gradually from 4000 psi (281 kg/cm<sup>2</sup>) to 1500 psi (105 kg/cm<sup>2</sup>). This is to simulate the effect of harsh environment on the strength of concrete in existing buildings.
文摘The new nanosolid superacid catalyst SO42-/TiO2 is compounded with nanometer chemical technology. This catalyst SO42-/TiO2 has good catalytic effects on esterificational reactions of ethylic acid and ethyl alcohol. It has many other advantages such as strong water proof quality, being able to be used repeatedly, being easy to be reclaimed, non corroding, non polluting. So it is a green industrial catalyst which is helpful to the environment and possesses wide prospect of applications. The crystallo process, specific surface area and sulphur content of the SO42-/TiO2 system have been studied with the method of XRD, XPS and the chemical analysis, the result of which indicates that catalytic activity and acid strength of SO42-/TiO2 is affected by the H2SO4 saturant concentration, baking temperature, precipitating condition, specific surface area and sulphur content. The best preparation conditions of SO42-/TiO2 are: ageing temperature at 0℃, 0.5mol·L-1 of H2SO4 concentration, baking temperature at 500℃and 3 hours of baking time.
文摘采用改性技术合成了新型的纳米固体超强酸催化剂S2O82-/ZrO2,该催化剂对醋酸和脂肪醇的酯化反应具有很好的催化作用,并且具有耐水性强、稳定性好、再生容易、可重复使用、不腐蚀设备、不污染环境等优点,是对环境友好的很有应用前景的绿色工业催化剂.用X射线衍射分析、X光电子能谱、TEM、红外光谱和化学分析等手段对S2O82-/ZrO2进行了表征.结果表明,浸渍液(NH4)2S2O8浓度、陈化温度、焙烧温度、沉淀条件、比表面积和含硫量均明显影响S2O82-/ZrO2的酸强度及催化活性.S2O82-/ZrO2最佳制备条件:陈化温度为-15℃,浸渍液(NH4)2S2O8浓度为0.5 mol/L,焙烧温度为600℃,焙烧时间为3 h.
文摘采用改性技术合成了新型的纳米固体超酸催化剂SO42-/Z rO2-S iO2,对醋酸和脂肪醇的酯化反应有很好的催化作用.该催化剂具有耐水性强,稳定性好,再生容易,可重复使用,不腐蚀设备,不污染环境,是对环境友好的很有应用前景的绿色工业催化剂.用XRD、XPS、TEM、IR和化学分析等手段分析了SO42-/Z rO2-S iO2的晶化过程,比表面积含硫量.结果表明浸渍液H2SO4浓度、陈化温度、焙烧温度、沉淀条件,比表面积和含硫量均明显影响SO42-/Z rO2-S iO2的酸强度及催化活性.SO42-/Z rO2-S iO2最佳制备条件:陈化温度-15℃,浸渍液H2SO4浓度为0.5 m o l/L,焙烧温度为650℃,焙烧时间为3 h.
文摘In my ten-yeat experience of tenching English as major in college , I feel that students experience more difficulties in listening lessons than in other lessons. What, then, prevents students from achieving success in the listening class? I suggest that anxiety is one of the major factors, which interferes with students listening comprehension. And I would agree with writers such as Gardner and Horwitz et al. (1991)that anxiety may impede learner’s ability to perform successfully in all aspects of learning a foreign language. I feet it is particularly significant for listening.
基金Project supported by the Ministry of Education,Science Technology(MEST)Korea Industrial Technology Foundation(KOTEF)through the Human Resource Training Project for Regional Innovation
文摘To improve the durability of underwater rotating products,the corrosion characteristics in harsh marine environment were evaluated through various electrochemical experiments on the Al2O3-3TiO2 and CoNiCrAlY coating layers by atmospheric pressure plasma spray coating process.By evaluating the corrosion resistance of these materials,their applicability to environmentally friendly power generation equipment such as blades of tidal current turbines was examined.According to the Tafel analysis for micro-areas including the coating layer,the coating/metal interlayer and the base metal,the Al2O3-3TiO2 coating layer and the CoNiCrAlY coating layer show markedly lower corrosion current density than the base metal.The corrosion current density of the CoNiCrAlY coating layer (9.75316×10-8A/cm2) is about 1.6 times more than that of the Al2O3-3TiO2 coating layer (6.13139×10-8A/cm2).
基金the National Natural Science Foundation of Chinaunder Grant Nos.6067316790412011(国家自然科学基金)the National Basic Research Program of Chinaunder GrantNo.2005CB321801(国家重点基础研究发展计划(973))
文摘作为面向互联网资源共享的虚拟计算环境的实例,iVCE(Internet based virtual computing environment)for Memory致力于解决广域分布的内存资源的共享与综合利用问题.由于内存资源的特殊性,传统的资源管理方法很难适用.以iVCE for Memory作为背景,提出一种基于聚类的虚拟计算环境资源聚合方法,有效降低了资源聚合的问题规模;借鉴物理学中的力场和势能理论,建立了实现资源聚合的基本模型和力场-势能模型以及相应的分布式算法;通过基于真实网络拓扑的模拟,对两种模型和算法分别进行了评估和验证.
