This essay briefly discusses different reflections of western and Chinese philosophy towards sea in poems.By the comparison of the evaluation of sea in Chinese and English poems,this essay reaches the conclusion that ...This essay briefly discusses different reflections of western and Chinese philosophy towards sea in poems.By the comparison of the evaluation of sea in Chinese and English poems,this essay reaches the conclusion that both cultures have sublime understanding towards sea.展开更多
Moby-Dick, a great masterpiece by Herman Melville, is acclaimed as an epic of the sea such as no man has equaled. This thesis focuses on Ahab and the aesthetic sublime in Moby Dick. Ahab proves himself to be a figure ...Moby-Dick, a great masterpiece by Herman Melville, is acclaimed as an epic of the sea such as no man has equaled. This thesis focuses on Ahab and the aesthetic sublime in Moby Dick. Ahab proves himself to be a figure of the aesthetic sublime in his chasing and fighting against the giant whale.展开更多
Metadiscourse is a significant method in revealing audience awareness,but related studies have been confined to linguistic markers and current writing analyses.This essay aims to enrich metadiscourse engagement in par...Metadiscourse is a significant method in revealing audience awareness,but related studies have been confined to linguistic markers and current writing analyses.This essay aims to enrich metadiscourse engagement in particular with certain rhetorical figures and to investigate audience awareness in a highly acclaimed Roman-era Greek classic:Longinus'On the Sublime.Drawing from a refined framework of engagement,we find explicit evidence of audience aware-ness as manifested in the author's use of engagement markers.We have sorted these markers into four types,including reader mentions(apostrophe and pro-nouns),directives(modal verbs and imperatives),questions(erotema and rogatio),and appeals to shared knowledge(emphasizers and comment clauses).We sug-gest that the frequent use of these engagement markers,in particular reader mentions,could be taken as evidence of the author's strong audience awareness and the cueing effect in facilitating perception.This integration of rhetorical fig-ures into the metadiscourse engagement markers contributes to the audience awareness analysis in a more explicit and comprehensive way.展开更多
Close-space sublimation(CSS)has been demonstrated as an alternative vacuum deposition technique for fabricating organic light-emitting diodes(OLEDs).CSS utilizes a planar donor plate pre-coated with organic thin films...Close-space sublimation(CSS)has been demonstrated as an alternative vacuum deposition technique for fabricating organic light-emitting diodes(OLEDs).CSS utilizes a planar donor plate pre-coated with organic thin films as an area source to rapidly transfer the donor film to a device substrate at temperatures below 200℃.CSS is also conformal and capable of depositing on odd-shaped substrates using flexible donor media.The evaporation behaviors of organic donor films under CSS were fully characterized using model OLED materials and CSS-deposited films exhibited comparable device performances in an OLED stack to films deposited by conventional point sources.The low temperature and conformal nature of CSS,along with its high material utilization and short process time,make it a promising method for fabricating flexible OLED displays.展开更多
A novel carbon-sulfur nano-composite material was synthesized by heating sublimed sulfur and high surface area activated carbon (HSAAC) under certain conditions. The physical and chemical per- formances of the novel...A novel carbon-sulfur nano-composite material was synthesized by heating sublimed sulfur and high surface area activated carbon (HSAAC) under certain conditions. The physical and chemical per- formances of the novel carbon-sulfur nano-composite were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and X-ray diffraction (XRD). The electrochemical performances of nano-composite were characterized by charge-discharge characteristic, cyclic voltammetry and electrochemical impendence spectroscopy (EIS). The experimental results indicate that the electrochemical capability of nano- composite material was superior to that of traditional S-containing composite material. The cathode made by carbon-sulfur nano-composite material shows a good cycle ability and a high specific charge-discharge capacity. The HSAAC shows a vital role in adsorbing sublimed sulfur and the polysulfides within the cathode and is an excellent electric conductor for a sulfur cathode and prevents the shuttle behavior of the lithium-sulfur battery.展开更多
The essay applies Edmund Burke's theory about the "sublime" and the "beautiful" to the reversal of the dominant and subordinate roles of the husband and the wife in The Merchant's Tale. Bur...The essay applies Edmund Burke's theory about the "sublime" and the "beautiful" to the reversal of the dominant and subordinate roles of the husband and the wife in The Merchant's Tale. Burk's concept of "the soft power", expounded as physical and sexual charm and enchantment, enables May successfully manipulates her husband January and the adulterer Damian, beneath her apparent passivity.展开更多
Yeats' lyrics of sublimation is one of his major concerns in his later years. Sublimation for Yeats is essentially the transmutation and elevation of bitterness and tragic facts of being into happiness, into tranq...Yeats' lyrics of sublimation is one of his major concerns in his later years. Sublimation for Yeats is essentially the transmutation and elevation of bitterness and tragic facts of being into happiness, into tranquility of mind, then into the emotionless emotion, as Yeats names it as "innocence". The process of sublimation enriches the creativity of Yeats as artist when he is confronted with severity of aging spiritually and physically.展开更多
Carbon-sulfur nano-composite cathodes for lithium rechargeable batteries were investigated by electrochemical impedance spectroscopy (EIS). The novel carbon-sulfur nano-composite material was synthesized by heating su...Carbon-sulfur nano-composite cathodes for lithium rechargeable batteries were investigated by electrochemical impedance spectroscopy (EIS). The novel carbon-sulfur nano-composite material was synthesized by heating sublimed sulfur and high surface area activated carbon (HSAAC) in certain conditions. Equivalent circuits were used to fit the spectra at different discharge states. The variations of impedance spectra, charge-transfer resistance and double layer capacitance were discussed. The changes of EIS with potential were analyzed based on a plausible electrical equivalent circuit model, and some parameters were measured and analyzed about electrochemical performance and state of charge and discharge of the electrode. The good accuracy in fitting values of the model to the experimental data indicates that the mathematical model gives out a satisfying description upon the mechanism of high rate of capacity fade in lithium-sulfur battery.展开更多
The globalization has a particular relation to the climate change, and conversely, the climate change also has a particular relation to the globalization. They live and exist together and often they are mentioned toge...The globalization has a particular relation to the climate change, and conversely, the climate change also has a particular relation to the globalization. They live and exist together and often they are mentioned together. It is however clear that the globalization can exist problemless without the climate change, while this can also be declared from the climate change. Nature and society have always been in a secret dialogue with each other, forming visible and invisible oppositions, taking over the role of the other and embodying universal values for the other side. Actually, we have an important change in the secret dialog. It is not about the fact, that this change is historical in the history of the nature. Until now, we protected the nature against the society, now we must also protect the society against the nature. The decisive change is the transformation of the idea of the nature protection in a practice of the mutual and double protection of the nature and the society.展开更多
The concept of chaos is present in man from the origins of mankind.Philosophy is alien to this concept and proceeds to speculate about its reality.Both Kant and Borges were not indifferent to this speculation and in t...The concept of chaos is present in man from the origins of mankind.Philosophy is alien to this concept and proceeds to speculate about its reality.Both Kant and Borges were not indifferent to this speculation and in their works,we can find“the effort to explain or to approach”the concept of chaos.Our first aim is to demonstrate in Kant’s The Critique of Judgement,and more precisely in The Analytic of the Sublime,what Kant understands as“chaos.”Our second aim is to establish a relationship between Kant and Borges in some of Borges’tales.Finally,we aim at establishing whether this“language of chaos”can refer to a sort of communication which exceeds logic language,i.e.,a sort of“mute logos.”展开更多
Longinus's On the Sublime holds a uniquely unparalleled position in Western critical theories. By analyzing Li Bai's well-known poem Cataract on Mount Lu from the perspective of sublimity, attempt is made to a...Longinus's On the Sublime holds a uniquely unparalleled position in Western critical theories. By analyzing Li Bai's well-known poem Cataract on Mount Lu from the perspective of sublimity, attempt is made to appreciate the ancient Chinese poems by using Western critical theory and thus derive another kind of aesthetic beauty.展开更多
High-resolution X-ray diffractometry (HRXRD) was used to assess the quality of 6H-SiC crystals grown by sublimation method. The results show the occurrence of low-angle grain boundaries (LB) is close relative to the i...High-resolution X-ray diffractometry (HRXRD) was used to assess the quality of 6H-SiC crystals grown by sublimation method. The results show the occurrence of low-angle grain boundaries (LB) is close relative to the inclination of the crystal interface. At the central faceted region with 0° inclination the crystal is of high structural perfection. However, at the region close to the facet with less than 5° inclination LB occurs slightly and at the region close to the peripheral polytype ring with more than 5° inclination LB defect occurs heavily. The density of LB can be drastically reduced by decreasing radial temperature gradient that determines the shape of the crystal growth interface.展开更多
This paper reports the ignition performance of the iodine-fueled radio frequency(RF)ion thruster(IRIT)at different anode temperaturesT_(a0).The experimental results show that the anode temperature plays important role...This paper reports the ignition performance of the iodine-fueled radio frequency(RF)ion thruster(IRIT)at different anode temperaturesT_(a0).The experimental results show that the anode temperature plays important role on the ignition process of the IRIT.There were two characteristic temperatures related to the anode:the minimum ignition temperatureT_(i0)and the stable ignition temperatureT_(is),which were much lower than the pipeline temperature and the storage tank temperature.AtT_(a0)<T_(i0),it failed to discharge.WhenT_(i0)≤T_(a0)<T_(is),it was ignited with dramatical oscillations.AtT_(a0)≥T_(is),the discharge was stable in a large anode temperature range.The analysis showed that the different discharge phenomena at different anode temperatures were attributed to the change of iodine flow rate during the process of the iodine deposition-clogging and sublimation-clearing inside the thruster.The research helps improve the preheating design of the iodine-fueled electric thruster.展开更多
In order to remediate heavy metal ions from waste water,Al2O3–SiO2 composite aerogels are prepared via a sol–gel and an organic solvent sublimation drying method.Various characterisation techniques have been employe...In order to remediate heavy metal ions from waste water,Al2O3–SiO2 composite aerogels are prepared via a sol–gel and an organic solvent sublimation drying method.Various characterisation techniques have been employed including X-ray diffraction(XRD),Fourier transform infrared spectrometry(FTIR),scanning electron microscope(SEM),Energy-dispersion X-ray spectroscopy(EDX),Brunauer–Emmett–Teller(BET)N2 adsoprtion isotherm,and atomic absorption spectrometer(AAS).XRD and FTIR suggest that the aerogels are composed of mainly Al2O3 and minor SiO2.They have a high specific surface area(827.544 m^2/g)and high porosity(86.0%)with a pore diameter of~20 nm.Their microstructures show that the distribution of Al,Si,and O is homogeneous.The aerogels can remove~99%Cu^2+within~40 min and then reach the equilibrium uptake(~69 mg/g).Preliminary calculations show that the Cu2+uptake by the aerogels follows pseudo second-order kinetics where chemical sorption may take effect owing largely to the high surface area,high porosity,and abundant functional groups,such as Al–OH and Si–OH,in the aerogel network.The prepared aerogels may serve as efficient absorbents for Cu^2+removal.展开更多
Blowing snow is an important part of snow hydrologic processes in mountainous region, however the related researches were rare for the Qilian mountainous region where blowing snow is frequent. Using the observation da...Blowing snow is an important part of snow hydrologic processes in mountainous region, however the related researches were rare for the Qilian mountainous region where blowing snow is frequent. Using the observation dataset in 2008 snow season in Binggou wa- tershed in Qilian mountainous region, we systematically studied the energy and mass processes of blowing snow by field observation and model simulation. The results include the analysis of snow observation, the occurrence probability of blowing snow, blowing snow transport and blowing snow sublimation. It was found that blowing snow was obvious in high altitude region (4,146 m), the snow redislribution phenomena was remarkable. In Yakou station in the study region, blowing snow was easily occurred in midwinter and early spring when no snowmelt, the blowing snow transport was dominated in this period; when snowmelt beginning, the occur- rence probability of blowing snow decreased heavily because of the increasing air temperature, melt, and refrozen phenomena. The blowing snow sublimation accounted for 41.5% of total snow sublimation at Yakou station in 2008 snow season.展开更多
We report the effects of post-thermal treatment on the quality of 2-inch 6H-SiC wafer cut from a crystal boule grown by physical vapour transportation method. The full widths at half maximum of x-ray diffraction rocki...We report the effects of post-thermal treatment on the quality of 2-inch 6H-SiC wafer cut from a crystal boule grown by physical vapour transportation method. The full widths at half maximum of x-ray diffraction rocking curves measured on sites across the 2-inch wafer become narrower, indicating the quality improvement after a three-step post-thermal treatment. It is found that the most common defects such as micropipes and inclusions can be significantly reduced after the treatment. Our results show that the post-thermal treatment is an effective route to improve the quality of SiC single crystals.展开更多
Mercuric chloride supported on activated carbon(HgCl_2/AC) is used as an industrial catalyst for the hydrochlorination of acetylene. Loss of HgCl_2 by sublimating from the surface of activated carbon causes the irreve...Mercuric chloride supported on activated carbon(HgCl_2/AC) is used as an industrial catalyst for the hydrochlorination of acetylene. Loss of HgCl_2 by sublimating from the surface of activated carbon causes the irreversible deactivation of mercury catalyst and environmental pollution. In this work, a ligand coordination approach based on the Principle of Hard and Soft Acids and Bases(HSAB) was employed to design more stable lowmercury catalyst. The low-mercury catalysts(4% HgCl_2 loading) were prepared by using HgCl_2 and potassium halides(KX, X = Cl, I) as precursors. The HgCl_2-4KI/AC catalyst showed best catalytic stability than HgCl_2/AC and HgCl_2-4KCl/AC in the hydrochloriantion of acetylene. HgCl_2 could form more stable complex with KI,K_2HgI_4 as the main active component of the HgCl_2-4KI/AC catalyst. The characterizations of XRD and EDX analysis illustrated that the active component of HgCl_2-4KI/AC was highly dispersed on the surface of activated carbon.The sublimation rates of HgCl_2 from the catalysts verified that the active component with larger stability constant had better thermal stability. Using Hg(Ⅱ) complexes with high stability constant as the active component may be the research direction of developing highly stable low-mercury catalyst for the hydrochlorination of acetylene.展开更多
The structure and characteristics of CdTe thin filrns are closely dependent on the whole deposition process in close-space sublimation (CSS). The physical mechanism of CSS was analyzed aud the temperature distributi...The structure and characteristics of CdTe thin filrns are closely dependent on the whole deposition process in close-space sublimation (CSS). The physical mechanism of CSS was analyzed aud the temperature distribution in CSS system was measured, and the influences of the increasing-temperature process and pressure on the preliminary nucleus creation were studied. The resuits indicate : tire samples deposited at different pressures hare a cubical structure of CdTe and the diffraction peaks of CdS and SnO2 : F. As the atmosphere pressure increases, the crystal size of CdTe decreases, the rate of the transparency of the thin film decreases and the absorption side moves towards the short-wave direction. After a 4-minute depositing process with a substrate teraw.rature of 500℃ and a source temperature of 620 ℃, the polycostallinc thin films can be mmade , so the production of high-quality integrated cell with StrO2: F/ CdS/ CdTe/ Au structure is hopeful.展开更多
文摘This essay briefly discusses different reflections of western and Chinese philosophy towards sea in poems.By the comparison of the evaluation of sea in Chinese and English poems,this essay reaches the conclusion that both cultures have sublime understanding towards sea.
文摘Moby-Dick, a great masterpiece by Herman Melville, is acclaimed as an epic of the sea such as no man has equaled. This thesis focuses on Ahab and the aesthetic sublime in Moby Dick. Ahab proves himself to be a figure of the aesthetic sublime in his chasing and fighting against the giant whale.
文摘Metadiscourse is a significant method in revealing audience awareness,but related studies have been confined to linguistic markers and current writing analyses.This essay aims to enrich metadiscourse engagement in particular with certain rhetorical figures and to investigate audience awareness in a highly acclaimed Roman-era Greek classic:Longinus'On the Sublime.Drawing from a refined framework of engagement,we find explicit evidence of audience aware-ness as manifested in the author's use of engagement markers.We have sorted these markers into four types,including reader mentions(apostrophe and pro-nouns),directives(modal verbs and imperatives),questions(erotema and rogatio),and appeals to shared knowledge(emphasizers and comment clauses).We sug-gest that the frequent use of these engagement markers,in particular reader mentions,could be taken as evidence of the author's strong audience awareness and the cueing effect in facilitating perception.This integration of rhetorical fig-ures into the metadiscourse engagement markers contributes to the audience awareness analysis in a more explicit and comprehensive way.
基金financially supported by the General Research Fund(16309918)from the Research Grant Council,Hong Kongfunding from the Institute for Advanced Study of the Hong Kong University of Science and Technology。
文摘Close-space sublimation(CSS)has been demonstrated as an alternative vacuum deposition technique for fabricating organic light-emitting diodes(OLEDs).CSS utilizes a planar donor plate pre-coated with organic thin films as an area source to rapidly transfer the donor film to a device substrate at temperatures below 200℃.CSS is also conformal and capable of depositing on odd-shaped substrates using flexible donor media.The evaporation behaviors of organic donor films under CSS were fully characterized using model OLED materials and CSS-deposited films exhibited comparable device performances in an OLED stack to films deposited by conventional point sources.The low temperature and conformal nature of CSS,along with its high material utilization and short process time,make it a promising method for fabricating flexible OLED displays.
基金the Science and Technique Key Foundation of Guangdong Province(No.2003A1100101,2003C105006)
文摘A novel carbon-sulfur nano-composite material was synthesized by heating sublimed sulfur and high surface area activated carbon (HSAAC) under certain conditions. The physical and chemical per- formances of the novel carbon-sulfur nano-composite were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and X-ray diffraction (XRD). The electrochemical performances of nano-composite were characterized by charge-discharge characteristic, cyclic voltammetry and electrochemical impendence spectroscopy (EIS). The experimental results indicate that the electrochemical capability of nano- composite material was superior to that of traditional S-containing composite material. The cathode made by carbon-sulfur nano-composite material shows a good cycle ability and a high specific charge-discharge capacity. The HSAAC shows a vital role in adsorbing sublimed sulfur and the polysulfides within the cathode and is an excellent electric conductor for a sulfur cathode and prevents the shuttle behavior of the lithium-sulfur battery.
文摘The essay applies Edmund Burke's theory about the "sublime" and the "beautiful" to the reversal of the dominant and subordinate roles of the husband and the wife in The Merchant's Tale. Burk's concept of "the soft power", expounded as physical and sexual charm and enchantment, enables May successfully manipulates her husband January and the adulterer Damian, beneath her apparent passivity.
文摘Yeats' lyrics of sublimation is one of his major concerns in his later years. Sublimation for Yeats is essentially the transmutation and elevation of bitterness and tragic facts of being into happiness, into tranquility of mind, then into the emotionless emotion, as Yeats names it as "innocence". The process of sublimation enriches the creativity of Yeats as artist when he is confronted with severity of aging spiritually and physically.
文摘Carbon-sulfur nano-composite cathodes for lithium rechargeable batteries were investigated by electrochemical impedance spectroscopy (EIS). The novel carbon-sulfur nano-composite material was synthesized by heating sublimed sulfur and high surface area activated carbon (HSAAC) in certain conditions. Equivalent circuits were used to fit the spectra at different discharge states. The variations of impedance spectra, charge-transfer resistance and double layer capacitance were discussed. The changes of EIS with potential were analyzed based on a plausible electrical equivalent circuit model, and some parameters were measured and analyzed about electrochemical performance and state of charge and discharge of the electrode. The good accuracy in fitting values of the model to the experimental data indicates that the mathematical model gives out a satisfying description upon the mechanism of high rate of capacity fade in lithium-sulfur battery.
文摘The globalization has a particular relation to the climate change, and conversely, the climate change also has a particular relation to the globalization. They live and exist together and often they are mentioned together. It is however clear that the globalization can exist problemless without the climate change, while this can also be declared from the climate change. Nature and society have always been in a secret dialogue with each other, forming visible and invisible oppositions, taking over the role of the other and embodying universal values for the other side. Actually, we have an important change in the secret dialog. It is not about the fact, that this change is historical in the history of the nature. Until now, we protected the nature against the society, now we must also protect the society against the nature. The decisive change is the transformation of the idea of the nature protection in a practice of the mutual and double protection of the nature and the society.
文摘The concept of chaos is present in man from the origins of mankind.Philosophy is alien to this concept and proceeds to speculate about its reality.Both Kant and Borges were not indifferent to this speculation and in their works,we can find“the effort to explain or to approach”the concept of chaos.Our first aim is to demonstrate in Kant’s The Critique of Judgement,and more precisely in The Analytic of the Sublime,what Kant understands as“chaos.”Our second aim is to establish a relationship between Kant and Borges in some of Borges’tales.Finally,we aim at establishing whether this“language of chaos”can refer to a sort of communication which exceeds logic language,i.e.,a sort of“mute logos.”
文摘Longinus's On the Sublime holds a uniquely unparalleled position in Western critical theories. By analyzing Li Bai's well-known poem Cataract on Mount Lu from the perspective of sublimity, attempt is made to appreciate the ancient Chinese poems by using Western critical theory and thus derive another kind of aesthetic beauty.
基金Project supported National Natural Science Foundation of China (60025409 and 50472068)National "863" High Technology Plan (2001AA311080)
文摘High-resolution X-ray diffractometry (HRXRD) was used to assess the quality of 6H-SiC crystals grown by sublimation method. The results show the occurrence of low-angle grain boundaries (LB) is close relative to the inclination of the crystal interface. At the central faceted region with 0° inclination the crystal is of high structural perfection. However, at the region close to the facet with less than 5° inclination LB occurs slightly and at the region close to the peripheral polytype ring with more than 5° inclination LB defect occurs heavily. The density of LB can be drastically reduced by decreasing radial temperature gradient that determines the shape of the crystal growth interface.
基金financial support from National Natural Science Foundation of China(No.11805265)Key Laboratory of Micro-Satellites,Chinese Academy of Sciences(No.KFKT201903)is gratefully acknowledged。
文摘This paper reports the ignition performance of the iodine-fueled radio frequency(RF)ion thruster(IRIT)at different anode temperaturesT_(a0).The experimental results show that the anode temperature plays important role on the ignition process of the IRIT.There were two characteristic temperatures related to the anode:the minimum ignition temperatureT_(i0)and the stable ignition temperatureT_(is),which were much lower than the pipeline temperature and the storage tank temperature.AtT_(a0)<T_(i0),it failed to discharge.WhenT_(i0)≤T_(a0)<T_(is),it was ignited with dramatical oscillations.AtT_(a0)≥T_(is),the discharge was stable in a large anode temperature range.The analysis showed that the different discharge phenomena at different anode temperatures were attributed to the change of iodine flow rate during the process of the iodine deposition-clogging and sublimation-clearing inside the thruster.The research helps improve the preheating design of the iodine-fueled electric thruster.
基金This work was financially supported by the National Natural Science Foundation of China(No.51602018)the Beijing Municipal Natural Science Foundation(No.2154052)+1 种基金the China Postdoctoral Science Foundation(No.2014M560044)the Fundamental Research Funds for the Central Universities,China(No.FRF-GF-17-B7).
文摘In order to remediate heavy metal ions from waste water,Al2O3–SiO2 composite aerogels are prepared via a sol–gel and an organic solvent sublimation drying method.Various characterisation techniques have been employed including X-ray diffraction(XRD),Fourier transform infrared spectrometry(FTIR),scanning electron microscope(SEM),Energy-dispersion X-ray spectroscopy(EDX),Brunauer–Emmett–Teller(BET)N2 adsoprtion isotherm,and atomic absorption spectrometer(AAS).XRD and FTIR suggest that the aerogels are composed of mainly Al2O3 and minor SiO2.They have a high specific surface area(827.544 m^2/g)and high porosity(86.0%)with a pore diameter of~20 nm.Their microstructures show that the distribution of Al,Si,and O is homogeneous.The aerogels can remove~99%Cu^2+within~40 min and then reach the equilibrium uptake(~69 mg/g).Preliminary calculations show that the Cu2+uptake by the aerogels follows pseudo second-order kinetics where chemical sorption may take effect owing largely to the high surface area,high porosity,and abundant functional groups,such as Al–OH and Si–OH,in the aerogel network.The prepared aerogels may serve as efficient absorbents for Cu^2+removal.
基金funded by the National Natural Science Foundation of China(Grant Nos.913252034100124041071227)
文摘Blowing snow is an important part of snow hydrologic processes in mountainous region, however the related researches were rare for the Qilian mountainous region where blowing snow is frequent. Using the observation dataset in 2008 snow season in Binggou wa- tershed in Qilian mountainous region, we systematically studied the energy and mass processes of blowing snow by field observation and model simulation. The results include the analysis of snow observation, the occurrence probability of blowing snow, blowing snow transport and blowing snow sublimation. It was found that blowing snow was obvious in high altitude region (4,146 m), the snow redislribution phenomena was remarkable. In Yakou station in the study region, blowing snow was easily occurred in midwinter and early spring when no snowmelt, the blowing snow transport was dominated in this period; when snowmelt beginning, the occur- rence probability of blowing snow decreased heavily because of the increasing air temperature, melt, and refrozen phenomena. The blowing snow sublimation accounted for 41.5% of total snow sublimation at Yakou station in 2008 snow season.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50132040 and 50302014, the National Basic Research Program of China, and the Knowledge Innovation Project of Chinese Academy of Sciences.
文摘We report the effects of post-thermal treatment on the quality of 2-inch 6H-SiC wafer cut from a crystal boule grown by physical vapour transportation method. The full widths at half maximum of x-ray diffraction rocking curves measured on sites across the 2-inch wafer become narrower, indicating the quality improvement after a three-step post-thermal treatment. It is found that the most common defects such as micropipes and inclusions can be significantly reduced after the treatment. Our results show that the post-thermal treatment is an effective route to improve the quality of SiC single crystals.
基金Supported by the National Natural Science Foundation of China(21476207)the China Postdoctoral Science Foundation(2016M592015)
文摘Mercuric chloride supported on activated carbon(HgCl_2/AC) is used as an industrial catalyst for the hydrochlorination of acetylene. Loss of HgCl_2 by sublimating from the surface of activated carbon causes the irreversible deactivation of mercury catalyst and environmental pollution. In this work, a ligand coordination approach based on the Principle of Hard and Soft Acids and Bases(HSAB) was employed to design more stable lowmercury catalyst. The low-mercury catalysts(4% HgCl_2 loading) were prepared by using HgCl_2 and potassium halides(KX, X = Cl, I) as precursors. The HgCl_2-4KI/AC catalyst showed best catalytic stability than HgCl_2/AC and HgCl_2-4KCl/AC in the hydrochloriantion of acetylene. HgCl_2 could form more stable complex with KI,K_2HgI_4 as the main active component of the HgCl_2-4KI/AC catalyst. The characterizations of XRD and EDX analysis illustrated that the active component of HgCl_2-4KI/AC was highly dispersed on the surface of activated carbon.The sublimation rates of HgCl_2 from the catalysts verified that the active component with larger stability constant had better thermal stability. Using Hg(Ⅱ) complexes with high stability constant as the active component may be the research direction of developing highly stable low-mercury catalyst for the hydrochlorination of acetylene.
文摘The structure and characteristics of CdTe thin filrns are closely dependent on the whole deposition process in close-space sublimation (CSS). The physical mechanism of CSS was analyzed aud the temperature distribution in CSS system was measured, and the influences of the increasing-temperature process and pressure on the preliminary nucleus creation were studied. The resuits indicate : tire samples deposited at different pressures hare a cubical structure of CdTe and the diffraction peaks of CdS and SnO2 : F. As the atmosphere pressure increases, the crystal size of CdTe decreases, the rate of the transparency of the thin film decreases and the absorption side moves towards the short-wave direction. After a 4-minute depositing process with a substrate teraw.rature of 500℃ and a source temperature of 620 ℃, the polycostallinc thin films can be mmade , so the production of high-quality integrated cell with StrO2: F/ CdS/ CdTe/ Au structure is hopeful.