A series of microcrystalline silicon thin films were fabricated by very high frequency plasma enhanced chemical vapor deposition （VHF-PECVD） at different silane concentrations in a P chamber. Through analysis of the...A series of microcrystalline silicon thin films were fabricated by very high frequency plasma enhanced chemical vapor deposition （VHF-PECVD） at different silane concentrations in a P chamber. Through analysis of the structural and electrical properties of these materials,we conclude that the photosensitivity slightly decreased then increased as the silane concentration increased,while the crystalline volume fraction indicates the opposite change. Results of XRD indicate that thin films have a （220） preferable orientation under certain conditions. Microcrystalline silicon solar cells with conversion efficiency 4. 7% and micromorph tandem solar cells 8.5% were fabricated by VHF-PECVD （p layer and i layer of microcrystalline silicon solar cells were deposited in P chamber）, respectively.展开更多
K2FeO4 powders were synthesized by the ex-situ and in-situ electrochemical methods, respectively, and characterized by infrared spectrum （IR）, scanning electron microscopy （SEM）, X-ray powder diffraction （XRD） a...K2FeO4 powders were synthesized by the ex-situ and in-situ electrochemical methods, respectively, and characterized by infrared spectrum （IR）, scanning electron microscopy （SEM）, X-ray powder diffraction （XRD） and BET. Their electrochemical performances were investigated by means of galvanostatic discharge and electrochemi-cal impedance spectroscopy （EIS）. The results of physical characterization showed that the two samples have simi-lar structural features, but their surface morphologies and oriented growth of the crystals are different, which results in smaller specific surface area and lower solubility of the ex-situ electrosynthesized K2FeO4 sample. The results of discharge experiments indicated that the ex-situ electrosythesized K2FeO4 electrode has much larger discharge ca-pacity and lower electrode polarization than the in-situ electrosynthesized K2FeO4 electrode. It was found from the results of EIS that lower electrochemical polarization might be responsible for the improvement on the discharge performance of the ex-situ electrosynthesized K2FeO4 electrode.展开更多
Starting with a simple presentation of location determination techniques, physical location and geographic location as two common kinds of location description methods are discussed. The semantic location concept is t...Starting with a simple presentation of location determination techniques, physical location and geographic location as two common kinds of location description methods are discussed. The semantic location concept is then introduced and a correction is given, which especially emphasizes that location property is an important part of semantic location. By analyzing the connotation and extension of every geographic location, what should be contained in a location property is determined. Using a hierarchical model, the relations and associations among locations are clearly described. To realize a formalized description of semantic location, an ontology technique that can adequately describe semantic information of location is used. Organized by ontology web language, a location ontology model allows semantic location to be read and processed by computer. The location ontology model realizes the knowledge description of location information and establishes an important foundation to personalized preference services in location based services.展开更多
In view of a series of challenges since Task-Based Language Teaching(TBLT) was introduced into China, we interviewed 14 front-line teachers in primary and secondary schools about their viewpoints and classroom strateg...In view of a series of challenges since Task-Based Language Teaching(TBLT) was introduced into China, we interviewed 14 front-line teachers in primary and secondary schools about their viewpoints and classroom strategies of TBLT. The results show teachers’ willingness to use TBLT. They adopt flexible teaching procedures, apply TBLT creatively, and explore task-based language assessment. The authors argue for inclusive non-doctrinaire approaches to TBLT, and propose to construct localized TBLT theory and practice with Chinese characteristics.展开更多
Capillary electrophoresis （CE） coupled with mass spectrometry （MS） with a sheath liquid interface is nowadays recognized as a powerful separation technique for drugs and metabolites analysis in human urine and can...Capillary electrophoresis （CE） coupled with mass spectrometry （MS） with a sheath liquid interface is nowadays recognized as a powerful separation technique for drugs and metabolites analysis in human urine and can be applied in numerous fields such as clinical toxicology, drug substitution monitoring, forensic sciences and antidoping. With an acidic background electrolyte containing 15 mM ammonium formate at pH 2.5 and a sheath liquid consisting in a mixture of isopropanol/water （50：50, v/v） with 0.5% formic acid, CE-ESI-MS in positive mode demonstrated excellent performance for simultaneous analysis of basic drugs of abuse and metabolites in urine （e.g. cocaine, amphetamine, morphine and phase II metabolites）. To achieve the desired level of sensitivity, two injection modes and three sample pre-treatments were evaluated. The detection of basic drugs and phase Ⅱ metabolites in diluted urine was achieved at concentrations above 1μg/mL. In order to enhance sensitivity, a sample preparation was required. A liquid-liquid extraction （LLE） was compared with solid-phase extraction. LLE was performed at alkaline pH and samples were electrokinetically injected. A chemometric approach （Doehlert design） was carried out in order to determine optimized injection parameters. Limits of detection （LOD） down to 10 ng/mL were reached with field-amplified sample injection but phase II metabolites were not extracted. Therefore, instead of LLE a SPE was performed on C 18 sorbent, and elution fraction after washing step containing phase Ⅱ metabolites was loaded on mixed-mode anion exchanger cartridges. After electrokinetic injection, this two-step SPE allowed LOD ca. 10 ng/mL for drugs and phase Ⅱ metabolites.展开更多
Charles Percy Snow declared his influential Rede Lecture, ＂The Two Cultures＂, in 1959. In his famous lecture, he told us that the most powerful revolutionary force in the world today is science, science is essential...Charles Percy Snow declared his influential Rede Lecture, ＂The Two Cultures＂, in 1959. In his famous lecture, he told us that the most powerful revolutionary force in the world today is science, science is essentially progressive, and the scientific culture is also a newer one. So Snow, after excluding scientific culture from the whole culture, calls the rest of the whole culture traditional culture. In his opinion, science is more important than humanities. All these ideas are faithfully reflected in his earlier literary work The Masters （1972b）. Snow＇s favor toward men of sciences in the novel is self-evident. ＂The Masters, therefore, may be considered as a political science novel rather than as a political novel＂. It was the Industrial Revolution which created our sensibility展开更多
As a new form of artistic expression, film has gone through a history of more than 100 years in China. Focusing on the aesthetic taste of the underclass, popular literary tradition, which highlights appreciation habit...As a new form of artistic expression, film has gone through a history of more than 100 years in China. Focusing on the aesthetic taste of the underclass, popular literary tradition, which highlights appreciation habits of the citizen stratum, is the quintessence of Chinese traditional culture. Breaking through the mode of Western films, the early Chinese film, referring to artistic elements in story-telling script, fiction, and drama in Song and Yuan Dynasties, has created new film genres of ＂unofficial historical film＂ and martial-art film which are positive results of the localization of early Chinese films. Though the unofficial historical film failed in adapting the theme of popular literature, its groundbreaking significance is still worth approving展开更多
To describe the deformation and strength characteristics of the corroded rock-like specimens containing a single crack under uniaxial compression,a damage constitutive model combining hydro-chemical damage with coupli...To describe the deformation and strength characteristics of the corroded rock-like specimens containing a single crack under uniaxial compression,a damage constitutive model combining hydro-chemical damage with coupling damage of micro-flaws and macro-cracks is proposed.Firstly,based on phenomenological theory,the damage variable of the rock-like specimens subjected to water environment erosion and chemical corrosion is obtained.Secondly,a coupled damage variable for cracked rock-like specimens is derived based on the Lemaitre strain equivalence hypothesis,which combines the Weibull statistical damage model for micro-flaws and the fracture mechanics model for a macro single crack.Then,considering the residual strength characteristics of the rock-like materials,the damage variable is modified by introducing the correction coefficient,and the damage constitutive model of the corroded rock-like specimens with a single crack under uniaxial compression is established.The model is verified by comparing the experimental stress−strain curves,and the results are in good agreement with those provided in the literature.Finally,the correction coefficient of the damage variable proposed in this paper is discussed.The damage constitutive model developed in this paper provides an effective method to describe the stress−strain relationship and residual strength characteristics of the corroded rock-like specimens with a single crack under uniaxial compression.展开更多
In the music education universities in China,the international music education and localization problem is a key problem in current society.It is also the music Chinese universities that must be facing the problem in ...In the music education universities in China,the international music education and localization problem is a key problem in current society.It is also the music Chinese universities that must be facing the problem in education development.In current international society today in our country, the international music education in China has also become the trend of music education,and how the music education internationalization at the same time keeps the Chinese traditional music culture has become a common problem that today＇ s music industry pays attention to.In this paper, it makes the analysis and discussion on the internationalization of foreign music education idea introducing to our country＇ s music education process and localization problem.展开更多
文摘A series of microcrystalline silicon thin films were fabricated by very high frequency plasma enhanced chemical vapor deposition （VHF-PECVD） at different silane concentrations in a P chamber. Through analysis of the structural and electrical properties of these materials,we conclude that the photosensitivity slightly decreased then increased as the silane concentration increased,while the crystalline volume fraction indicates the opposite change. Results of XRD indicate that thin films have a （220） preferable orientation under certain conditions. Microcrystalline silicon solar cells with conversion efficiency 4. 7% and micromorph tandem solar cells 8.5% were fabricated by VHF-PECVD （p layer and i layer of microcrystalline silicon solar cells were deposited in P chamber）, respectively.
基金Supported by the National Natural Science Foundation of China (No.50172041)partly by the Chinese State Key Labora-tory for Corrosion and Protection.
文摘K2FeO4 powders were synthesized by the ex-situ and in-situ electrochemical methods, respectively, and characterized by infrared spectrum （IR）, scanning electron microscopy （SEM）, X-ray powder diffraction （XRD） and BET. Their electrochemical performances were investigated by means of galvanostatic discharge and electrochemi-cal impedance spectroscopy （EIS）. The results of physical characterization showed that the two samples have simi-lar structural features, but their surface morphologies and oriented growth of the crystals are different, which results in smaller specific surface area and lower solubility of the ex-situ electrosynthesized K2FeO4 sample. The results of discharge experiments indicated that the ex-situ electrosythesized K2FeO4 electrode has much larger discharge ca-pacity and lower electrode polarization than the in-situ electrosynthesized K2FeO4 electrode. It was found from the results of EIS that lower electrochemical polarization might be responsible for the improvement on the discharge performance of the ex-situ electrosynthesized K2FeO4 electrode.
基金Supported by the Open Research Fund Program of the Geomatics and Applications Laboratory, Liaoning Technical University (No. 2005001).
文摘Starting with a simple presentation of location determination techniques, physical location and geographic location as two common kinds of location description methods are discussed. The semantic location concept is then introduced and a correction is given, which especially emphasizes that location property is an important part of semantic location. By analyzing the connotation and extension of every geographic location, what should be contained in a location property is determined. Using a hierarchical model, the relations and associations among locations are clearly described. To realize a formalized description of semantic location, an ontology technique that can adequately describe semantic information of location is used. Organized by ontology web language, a location ontology model allows semantic location to be read and processed by computer. The location ontology model realizes the knowledge description of location information and establishes an important foundation to personalized preference services in location based services.
基金supported by the National Social Science Funding Project in China(16BYY080)。
文摘In view of a series of challenges since Task-Based Language Teaching(TBLT) was introduced into China, we interviewed 14 front-line teachers in primary and secondary schools about their viewpoints and classroom strategies of TBLT. The results show teachers’ willingness to use TBLT. They adopt flexible teaching procedures, apply TBLT creatively, and explore task-based language assessment. The authors argue for inclusive non-doctrinaire approaches to TBLT, and propose to construct localized TBLT theory and practice with Chinese characteristics.
文摘Capillary electrophoresis （CE） coupled with mass spectrometry （MS） with a sheath liquid interface is nowadays recognized as a powerful separation technique for drugs and metabolites analysis in human urine and can be applied in numerous fields such as clinical toxicology, drug substitution monitoring, forensic sciences and antidoping. With an acidic background electrolyte containing 15 mM ammonium formate at pH 2.5 and a sheath liquid consisting in a mixture of isopropanol/water （50：50, v/v） with 0.5% formic acid, CE-ESI-MS in positive mode demonstrated excellent performance for simultaneous analysis of basic drugs of abuse and metabolites in urine （e.g. cocaine, amphetamine, morphine and phase II metabolites）. To achieve the desired level of sensitivity, two injection modes and three sample pre-treatments were evaluated. The detection of basic drugs and phase Ⅱ metabolites in diluted urine was achieved at concentrations above 1μg/mL. In order to enhance sensitivity, a sample preparation was required. A liquid-liquid extraction （LLE） was compared with solid-phase extraction. LLE was performed at alkaline pH and samples were electrokinetically injected. A chemometric approach （Doehlert design） was carried out in order to determine optimized injection parameters. Limits of detection （LOD） down to 10 ng/mL were reached with field-amplified sample injection but phase II metabolites were not extracted. Therefore, instead of LLE a SPE was performed on C 18 sorbent, and elution fraction after washing step containing phase Ⅱ metabolites was loaded on mixed-mode anion exchanger cartridges. After electrokinetic injection, this two-step SPE allowed LOD ca. 10 ng/mL for drugs and phase Ⅱ metabolites.
文摘Charles Percy Snow declared his influential Rede Lecture, ＂The Two Cultures＂, in 1959. In his famous lecture, he told us that the most powerful revolutionary force in the world today is science, science is essentially progressive, and the scientific culture is also a newer one. So Snow, after excluding scientific culture from the whole culture, calls the rest of the whole culture traditional culture. In his opinion, science is more important than humanities. All these ideas are faithfully reflected in his earlier literary work The Masters （1972b）. Snow＇s favor toward men of sciences in the novel is self-evident. ＂The Masters, therefore, may be considered as a political science novel rather than as a political novel＂. It was the Industrial Revolution which created our sensibility
文摘As a new form of artistic expression, film has gone through a history of more than 100 years in China. Focusing on the aesthetic taste of the underclass, popular literary tradition, which highlights appreciation habits of the citizen stratum, is the quintessence of Chinese traditional culture. Breaking through the mode of Western films, the early Chinese film, referring to artistic elements in story-telling script, fiction, and drama in Song and Yuan Dynasties, has created new film genres of ＂unofficial historical film＂ and martial-art film which are positive results of the localization of early Chinese films. Though the unofficial historical film failed in adapting the theme of popular literature, its groundbreaking significance is still worth approving
基金Project(FRF-IDRY-20-013)supported by the Fundamental Research Funds for the Central Universities,ChinaProjects(51974014,52074020)supported by the National Natural Science Foundation of China。
文摘To describe the deformation and strength characteristics of the corroded rock-like specimens containing a single crack under uniaxial compression,a damage constitutive model combining hydro-chemical damage with coupling damage of micro-flaws and macro-cracks is proposed.Firstly,based on phenomenological theory,the damage variable of the rock-like specimens subjected to water environment erosion and chemical corrosion is obtained.Secondly,a coupled damage variable for cracked rock-like specimens is derived based on the Lemaitre strain equivalence hypothesis,which combines the Weibull statistical damage model for micro-flaws and the fracture mechanics model for a macro single crack.Then,considering the residual strength characteristics of the rock-like materials,the damage variable is modified by introducing the correction coefficient,and the damage constitutive model of the corroded rock-like specimens with a single crack under uniaxial compression is established.The model is verified by comparing the experimental stress−strain curves,and the results are in good agreement with those provided in the literature.Finally,the correction coefficient of the damage variable proposed in this paper is discussed.The damage constitutive model developed in this paper provides an effective method to describe the stress−strain relationship and residual strength characteristics of the corroded rock-like specimens with a single crack under uniaxial compression.
文摘In the music education universities in China,the international music education and localization problem is a key problem in current society.It is also the music Chinese universities that must be facing the problem in education development.In current international society today in our country, the international music education in China has also become the trend of music education,and how the music education internationalization at the same time keeps the Chinese traditional music culture has become a common problem that today＇ s music industry pays attention to.In this paper, it makes the analysis and discussion on the internationalization of foreign music education idea introducing to our country＇ s music education process and localization problem.
