Simulations of photoresist etching,aerial image,exposure,and post-bake processes are integrated to obtain a photolithography process simulation for microelectromechanical system（MEMS） and integrated circuit（IC） fa...Simulations of photoresist etching,aerial image,exposure,and post-bake processes are integrated to obtain a photolithography process simulation for microelectromechanical system（MEMS） and integrated circuit（IC） fabrication based on three-dimensional （3D） cellular automata（CA）. The simulation results agree well with available experimental results. This indicates that the 3D dynamic CA model for the photoresist etching simulation and the 3D CA model for the post-bake simulation could be useful for the monolithic simulation of various lithography processes. This is determined to be useful for the device-sized fabrication process simulation of IC and MEMS.展开更多
Twelve samples with periodic array square pillars microstructure were prepared on the silicon wafer by plasma etching techniques, on which space b of the square pillars increased from 5 to 60 μm. In order to study th...Twelve samples with periodic array square pillars microstructure were prepared on the silicon wafer by plasma etching techniques, on which space b of the square pillars increased from 5 to 60 μm. In order to study the effect ofb on the wettability of the rough surface, the effects of apparent contact angle （CA） and sliding angle （a） of the droplet on the rough surface were measured with the contact angle meter. The results show that the experimental values of CA well agree with the classical wetting theory and a decreases with the increase of b. Two drop shapes exist on the samples＇ surface, corresponding to the Cassie state and the Wenzel state respectively. The contact state in which a drop would settle depends typically on the size of b. On the role of gravitation, the irreversible transition of a drop from Cassie state to Wenzel state should occur at a certain space of the square pillars. Since the transition has implications on the application of super-hydrophobic rough surfaces, theoretically, the prediction of wetting state transition on square pillar array micro-structured surfaces provides an intuitionistic guidance for the design of steady superhydrophobic surfaces.展开更多
The purpose of this work has been to carry out a didactic exhibit at the Botanical Museum of the Department of Life and Environment of the University of Cagliari devoted to vegetal endemic or threatened species presen...The purpose of this work has been to carry out a didactic exhibit at the Botanical Museum of the Department of Life and Environment of the University of Cagliari devoted to vegetal endemic or threatened species present at the Mediterranean Basin. The Ceroplastics （wax sculpting） plays a very important role in this project. Species that have become rare or are somehow threatened in the natural environment and have fortunately been preserved ＂ex situ＂ at the Botanical Garden of Cagliari are reproduced as wax models. Models are made by cutting and shaping wax sheets over the flame of an alcohol lamp. Each model has been created by copying a real specimen cultivated at the Botanical Garden and as a ＂unique piece＂ without using preparatory moulds. The result has been to have at our disposal a collection of very realistic models and magnified particulars as for example the pollen grains. The accuracy of the representation gives visitors the chance to know the considered species by means of the models. In order to preserve the natural heritage it is of the utmost importance that divulgation and information be made available to everyone. The Botanical Museum of the University of Cagliari rediscovers the noble art of wax sculpting, which has been strongly linked to the spreading of scientific knowledge since the XVII century and nowadays it may contribute to raise the citizens＇ awareness of the most common environmental issues.展开更多
Transferring MoS2 films from growth substrates onto target substrates is a critical issue for their practical applications. Moreover, it remains a great challenge to avoid sample degradation and substrate destruction,...Transferring MoS2 films from growth substrates onto target substrates is a critical issue for their practical applications. Moreover, it remains a great challenge to avoid sample degradation and substrate destruction, because the current transfer method inevitably employs a wet chemical etching process. We developed an etching-free transfer method for transferring MoS2 films onto arbitrary substrates by using ultrasonication. Briefly, the collapse of ultrasonication-generated microbubbles at the interface between polymer-coated MoS2 film and substrates induce sufficient force to delaminate the MoS2 films. Using this method, the MoS2 films can be transferred from all substrates （silica, mica, strontium titanate, and sapphire） and retains the original sample morphology and quality. This method guarantees a simple transfer process and allows the reuse of growth substrates, without involving any hazardous etchants. The etching-free transfer method is likely to promote broad applications of MoS2 in photodetectors.展开更多
Using multiple methods including questionnaires, in-depth interviews, participant observation and field experiments, we have identified two social-psychological mechanisms in educational inequality： the self-fulfilli...Using multiple methods including questionnaires, in-depth interviews, participant observation and field experiments, we have identified two social-psychological mechanisms in educational inequality： the self-fulfilling prophecy ofparentaI expectations at home and the threat of stereotyping encountered at school. The physical mechanism of educational inequality is manifested in the poor health of migrant workers＇ children and their devalued behavior. Targeting these physical and psychological mechanisms, we have designed two simple but effective intervention strategies to raise the children＇s academic achievement： passing on the incremental theory of intelligence and establishing a multiple assessment system. These intervention strategies effectively improved the children＇s academic performance, increased their identification with learning, and lowered the stereotype threat. It is hoped that these strategies can be applied to the new generation of migrant workers entering the labor market.展开更多
Patterned ferromagnetic thin film shows promising applications in ultra-high density magnetic storage,magnetoresistive transducer,magnetic random access memory and many other devices.Since the performance of these dev...Patterned ferromagnetic thin film shows promising applications in ultra-high density magnetic storage,magnetoresistive transducer,magnetic random access memory and many other devices.Since the performance of these devices is closely associated with the magnetic properties of the etched patterns,it is necessary to study the effects of freshly etched surface oxidation on the magnetic properties of the patterned microstructures.In the current work,were carried out an X-ray Magnetic Circular Dichroism(XMCD) study on a 50 nm Co 0.9 Fe 0.1 continuous thin film and a related patterned Co 0.9 Fe 0.1 grating structure etched with a 2 μm period.Based on the sum rules,the spin and orbital moments were calculated for these two samples,respectively.The results indicated that the spin and orbital moments of grating structure(1.34μ B and 0.24μ B,respectively) decreased 17.3% compared with the corresponding continuous film(1.62μ B and 0.29μ B,respectively).We proposed that the moment decreasing of the patterned grating structure was mainly caused by the etched surface oxidation during the pattern manufacture process.The oxidation ratio of Co element in the patterned grating structure is 14.4% calculated from X-ray absorption spectroscopy(XAS) measurement.Considering the oxidation ratio,we amend the spin and orbital moment of Co and the amended result is basically in accordance with that of continuous film,demonstrating that the difference of the spin and orbital moments between the sub-micron grating unit and the continuous film is really caused by the oxidation.展开更多
We present measurements of the in situ, microscopic architecture of a self- assembled bilayer at the interface between a regularly nanopatterned surface and an aqueous sub-phase using neutron reflectometry. The substr...We present measurements of the in situ, microscopic architecture of a self- assembled bilayer at the interface between a regularly nanopatterned surface and an aqueous sub-phase using neutron reflectometry. The substrate is patterned with a rectangular array of nanoscale holes. Because of the high quality of the pattern, using neutron reflectometry, we are able to map the surface-normal density distribution of the patterned silicon, the penetration of water into the pattern, and the distribution of a deposited film inside and outside of the etched holes. In this stud; 1,2-dilauroyl-sn-glycero-3-phosphocholine （DLPC） single bilayers were deposited on the hydrophilic patterned surface. For bilayers deposited either by vesicle fusion （VF） or by the Langmuir-Schaefer （L-S） technique, the most consistent model found to fit the data shows that the lipids form bilayer coatings on top of the substrate as well as the bottoms of the holes in an essentially conformal fashion. However, while there is a single bilayer on the unetched silicon surface, the lipids coating the bottoms of the holes form a complex bimodal structure consistent with a rough surface produced by the etching process. This study provides insight into film transfer both outside and inside regular nanopatterned features.展开更多
文摘Simulations of photoresist etching,aerial image,exposure,and post-bake processes are integrated to obtain a photolithography process simulation for microelectromechanical system（MEMS） and integrated circuit（IC） fabrication based on three-dimensional （3D） cellular automata（CA）. The simulation results agree well with available experimental results. This indicates that the 3D dynamic CA model for the photoresist etching simulation and the 3D CA model for the post-bake simulation could be useful for the monolithic simulation of various lithography processes. This is determined to be useful for the device-sized fabrication process simulation of IC and MEMS.
基金Project(50435030) supported by the National Natural Science foundation of ChinaProject supported by the Program for New Century Excellent Talents in Chinese University Project(GZ080010) supported by the Open Research Fund Program of Jiangsu Province Key Laboratory for Photon Manufacturing Science and Technology
文摘Twelve samples with periodic array square pillars microstructure were prepared on the silicon wafer by plasma etching techniques, on which space b of the square pillars increased from 5 to 60 μm. In order to study the effect ofb on the wettability of the rough surface, the effects of apparent contact angle （CA） and sliding angle （a） of the droplet on the rough surface were measured with the contact angle meter. The results show that the experimental values of CA well agree with the classical wetting theory and a decreases with the increase of b. Two drop shapes exist on the samples＇ surface, corresponding to the Cassie state and the Wenzel state respectively. The contact state in which a drop would settle depends typically on the size of b. On the role of gravitation, the irreversible transition of a drop from Cassie state to Wenzel state should occur at a certain space of the square pillars. Since the transition has implications on the application of super-hydrophobic rough surfaces, theoretically, the prediction of wetting state transition on square pillar array micro-structured surfaces provides an intuitionistic guidance for the design of steady superhydrophobic surfaces.
文摘The purpose of this work has been to carry out a didactic exhibit at the Botanical Museum of the Department of Life and Environment of the University of Cagliari devoted to vegetal endemic or threatened species present at the Mediterranean Basin. The Ceroplastics （wax sculpting） plays a very important role in this project. Species that have become rare or are somehow threatened in the natural environment and have fortunately been preserved ＂ex situ＂ at the Botanical Garden of Cagliari are reproduced as wax models. Models are made by cutting and shaping wax sheets over the flame of an alcohol lamp. Each model has been created by copying a real specimen cultivated at the Botanical Garden and as a ＂unique piece＂ without using preparatory moulds. The result has been to have at our disposal a collection of very realistic models and magnified particulars as for example the pollen grains. The accuracy of the representation gives visitors the chance to know the considered species by means of the models. In order to preserve the natural heritage it is of the utmost importance that divulgation and information be made available to everyone. The Botanical Museum of the University of Cagliari rediscovers the noble art of wax sculpting, which has been strongly linked to the spreading of scientific knowledge since the XVII century and nowadays it may contribute to raise the citizens＇ awareness of the most common environmental issues.
基金Acknowledgements This work was financially supported by the National Natural Science Foundation of China （Nos. 51222201, 51290272, 51472008, and 51432002）, the National Basic Research Program of China （Nos. 2012CB921404, 2013CB932603, 2012CB933404, and 2011CB921903）, and the Foundation for Innovative Research Groups of the National Natural Science Foundation of China （No. 51121091）.
文摘Transferring MoS2 films from growth substrates onto target substrates is a critical issue for their practical applications. Moreover, it remains a great challenge to avoid sample degradation and substrate destruction, because the current transfer method inevitably employs a wet chemical etching process. We developed an etching-free transfer method for transferring MoS2 films onto arbitrary substrates by using ultrasonication. Briefly, the collapse of ultrasonication-generated microbubbles at the interface between polymer-coated MoS2 film and substrates induce sufficient force to delaminate the MoS2 films. Using this method, the MoS2 films can be transferred from all substrates （silica, mica, strontium titanate, and sapphire） and retains the original sample morphology and quality. This method guarantees a simple transfer process and allows the reuse of growth substrates, without involving any hazardous etchants. The etching-free transfer method is likely to promote broad applications of MoS2 in photodetectors.
基金the Major Project of the Key Research Institute for Humanities and Social Sciences of the Ministry of Education(Center for Sociological Research and Development Studies of China,Peking University)for 2011(Grant No.11JJD840003)led by Professor Fang Wen,with financial aid from the Doctoral Program Research Fund of Harbin University of Commerce
文摘Using multiple methods including questionnaires, in-depth interviews, participant observation and field experiments, we have identified two social-psychological mechanisms in educational inequality： the self-fulfilling prophecy ofparentaI expectations at home and the threat of stereotyping encountered at school. The physical mechanism of educational inequality is manifested in the poor health of migrant workers＇ children and their devalued behavior. Targeting these physical and psychological mechanisms, we have designed two simple but effective intervention strategies to raise the children＇s academic achievement： passing on the incremental theory of intelligence and establishing a multiple assessment system. These intervention strategies effectively improved the children＇s academic performance, increased their identification with learning, and lowered the stereotype threat. It is hoped that these strategies can be applied to the new generation of migrant workers entering the labor market.
基金supported by the National Natural Science Foundation of China (Grant No. 10274073)the Post-doctoral Research Start-up Funding of Anhui University of Architecture (Grant No. K02553)the Open Project of Building Energy Conservation Institute of Anhui University of Architecture (Grant No. K02592)
文摘Patterned ferromagnetic thin film shows promising applications in ultra-high density magnetic storage,magnetoresistive transducer,magnetic random access memory and many other devices.Since the performance of these devices is closely associated with the magnetic properties of the etched patterns,it is necessary to study the effects of freshly etched surface oxidation on the magnetic properties of the patterned microstructures.In the current work,were carried out an X-ray Magnetic Circular Dichroism(XMCD) study on a 50 nm Co 0.9 Fe 0.1 continuous thin film and a related patterned Co 0.9 Fe 0.1 grating structure etched with a 2 μm period.Based on the sum rules,the spin and orbital moments were calculated for these two samples,respectively.The results indicated that the spin and orbital moments of grating structure(1.34μ B and 0.24μ B,respectively) decreased 17.3% compared with the corresponding continuous film(1.62μ B and 0.29μ B,respectively).We proposed that the moment decreasing of the patterned grating structure was mainly caused by the etched surface oxidation during the pattern manufacture process.The oxidation ratio of Co element in the patterned grating structure is 14.4% calculated from X-ray absorption spectroscopy(XAS) measurement.Considering the oxidation ratio,we amend the spin and orbital moment of Co and the amended result is basically in accordance with that of continuous film,demonstrating that the difference of the spin and orbital moments between the sub-micron grating unit and the continuous film is really caused by the oxidation.
文摘We present measurements of the in situ, microscopic architecture of a self- assembled bilayer at the interface between a regularly nanopatterned surface and an aqueous sub-phase using neutron reflectometry. The substrate is patterned with a rectangular array of nanoscale holes. Because of the high quality of the pattern, using neutron reflectometry, we are able to map the surface-normal density distribution of the patterned silicon, the penetration of water into the pattern, and the distribution of a deposited film inside and outside of the etched holes. In this stud; 1,2-dilauroyl-sn-glycero-3-phosphocholine （DLPC） single bilayers were deposited on the hydrophilic patterned surface. For bilayers deposited either by vesicle fusion （VF） or by the Langmuir-Schaefer （L-S） technique, the most consistent model found to fit the data shows that the lipids form bilayer coatings on top of the substrate as well as the bottoms of the holes in an essentially conformal fashion. However, while there is a single bilayer on the unetched silicon surface, the lipids coating the bottoms of the holes form a complex bimodal structure consistent with a rough surface produced by the etching process. This study provides insight into film transfer both outside and inside regular nanopatterned features.
