The pyrolysis of direct-coal-liquefaction residue(DCLR)was prepared using microwave and conventional pyrolysis.The composition and structure of solid coke,tar and gas were investigated and the pyrolysis products were ...The pyrolysis of direct-coal-liquefaction residue(DCLR)was prepared using microwave and conventional pyrolysis.The composition and structure of solid coke,tar and gas were investigated and the pyrolysis products were compared after characterization by infrared spectroscopy(FTIR)and gas chromatography-mass spectrometry(GC-MS).Results showed that DCLR was rapidly heated up to 900℃in 20 min with the maximum heating rate of 329℃·min-1 in the microwave field,while the heating rate of conventional heating was constant.Compared with conventional pyrolysis,coke yield decreased by 3%after microwave pyrolysis,whereas the tar and gas yields increased by 0.66%and 2.19%,respectively.After thepyrolysis of DCLR,the extracted compositions consisting of heavy oil(HS),as phaltene(A),and pre-asphaltene(PA)decreased significantly,while the contentof tetrahydrofuran insolubles(THFIS)increased.The Soxhlet compositions of thesolid coke did not evidently change compared with those after conventional pyrolysis,which indicated that the pyrolysis process of DCLR is mainly based on theconversion of HS,A and PA.After microwave pyrolysis,the intensity of the absorption peak at 3437.6,1632 and 1079.99 cm-1 on the infrared spectrumof the solid coke was significantly lower than that of conventional pyrolysis,which indicated that DCLR was more thoroughly pyrolyzed in the microwave field.Both tar and gas yields increased after pyrolysis,and the content of H 2 in gas reached above 60%.The results of GC-MS showed that no obvious change in thecomposition for aliphatics,aromatics,alcohol and the contents of C 1~5,C11~20 and C>20 in tar was observed after extraction with petroleum ether.The asphaltene content of tar decreased by 7.7%after microwave pyrolysis,which indicated that microwave pyrolysis can effectively promote asphaltene decomposition in DCLR,which benefited tar conversion to light fraction.展开更多
该文使用文献计量学方法,分析了中国学术期刊全文数据库(CNKI)和Web of Science(WOS)两个数据库中中国灵长类文献的特征。结果表明,行为、进化和保护是当前中国灵长类研究的主要方向;中英文文献中,猕猴和仰鼻猴都是研究最多的类群,其中...该文使用文献计量学方法,分析了中国学术期刊全文数据库(CNKI)和Web of Science(WOS)两个数据库中中国灵长类文献的特征。结果表明,行为、进化和保护是当前中国灵长类研究的主要方向;中英文文献中,猕猴和仰鼻猴都是研究最多的类群,其中普通猕猴、金仰鼻猴和黑白仰鼻猴的研究成果最多;与类群相对应,秦岭、太行山、神农架和云南是主要的研究地点;从WOS数据库看,灵长类的研究成果体现了很好的国内外机构合作态势,但从CNKI数据库看,国内机构合作还有待加强。未来中国灵长类学发展建议着重以下几个方面:一致化物种中文命名,促进保护和提升研究影响;创新研究方法,开展长期生态监测,覆盖更多物种;加强野外调查,完善中国灵长类多样性和保护信息;加强合作研究。展开更多
The title compound, (C33H42N4O12K)C6H2N3O7·H2O·CH3OH,Mr = 1003. 98,space group P1,a=11. 458(2) ,b= 14. 565(6) ,c=15. 828(3) A ;α=63. 34 (2),β=74. 06(1),γ=81. 03(2)°,V=2268. 1 A3;Z = 2,Dx = l. 47g/cm3...The title compound, (C33H42N4O12K)C6H2N3O7·H2O·CH3OH,Mr = 1003. 98,space group P1,a=11. 458(2) ,b= 14. 565(6) ,c=15. 828(3) A ;α=63. 34 (2),β=74. 06(1),γ=81. 03(2)°,V=2268. 1 A3;Z = 2,Dx = l. 47g/cm3,λ=0. 71069 A (MoKa).The final R = 0. 041 for 1700 observed reflections (I≥3σ(I)). The molecule is sandwich-like, and the cation K+ is sandwiched between the two crown rings.展开更多
Atomic and close-to-atomic scale manufacturing is the key technology for the production of next-generation devices with atomic precision.As an important approach of mechanical processing,cutting has evolved as a poten...Atomic and close-to-atomic scale manufacturing is the key technology for the production of next-generation devices with atomic precision.As an important approach of mechanical processing,cutting has evolved as a potential candidate to generate an atomically smooth surface;thus,exploring its ultimate capability is significant.In this paper,single-crystal graphite,whose lattice structure and chemical bond property are of representation for demonstration,is selected to study the mechanism of atomic layer removal using molecular dynamics.A localized workpiece,which is dynamically updated on the basis of the tool position,is used to improve the computation efficiency.The principle and bullet points of this modeling method are first introduced,followed by a series of simulations under various undeformed chip thicknesses and tool edge radi.In addition,different potentials for the tool-workpiece interaction are tested,and the effect on the material response is presented.Based on the analysis of deformation,the number of carbon layers removed,and cutting forces,the chip formation mechanism and further understanding of the controllability of cutting at atomic and close-to-atomic scale can be achieved.展开更多
The aim of this work is to investigate the dependence of Zn S thin films structural and optical properties with the solution flow rate during the deposition using an ultrasonic spray method. The solution flow rate ran...The aim of this work is to investigate the dependence of Zn S thin films structural and optical properties with the solution flow rate during the deposition using an ultrasonic spray method. The solution flow rate ranged from 10 to 50 m L/h and the substrate temperature was maintained at 450 °C. The effect of the solution flow rate on the properties of Zn S thin films was investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, optical transmittance spectroscopy（UV–V） and the four-point method. The X-ray diffraction analysis showed that the deposited material was pure zinc sulphide, it has a cubic sphalerite structure with preferential orientation along the（111） direction. The grain size values were calculated and found to be between 38 to 82 nm.SEM analysis revealed that the deposited thin films have good adherence to the substrate surfaces, are homogeneous and have high density. The average transmission of all films is up more than 65% in the range wavelength from 200 to 1100 nm and their band gap energy values were found between 3.5–3.92 e V. The obtained film thickness varies from 390 to 1040 nm. Moreover, the electric resistivity of the deposited films increases with the increasing of the solution flow rate between 3.51 × 10^5 and 11 × 10^5 Ω·cm.展开更多
The study of luminescence phenomena in non-conjugated systems,namely clusteroluminescence,has gained significant attention for the development of advanced luminescent materials.While conventional strategies to manipul...The study of luminescence phenomena in non-conjugated systems,namely clusteroluminescence,has gained significant attention for the development of advanced luminescent materials.While conventional strategies to manipulate the luminescent performances are based on complicated chemical reactions.In contrast,nature employs complexation to modulate luminescence,inspiring researchers to adopt an engineering approach for the construction of efficient clusteroluminogens.In this work,we explore the complexationinduced clusteroluminescence of carbonyl-based polymers with nitrogen-containing organic bases,exemplified by polyamide,polyester,polycarbonate,and poly(monothiocarbonate).展开更多
基金the National Natural Science Foundation of China(51504180,51774227)Natural Science Foundation of Shaanxi Province,China(2014JQ7266)
文摘The pyrolysis of direct-coal-liquefaction residue(DCLR)was prepared using microwave and conventional pyrolysis.The composition and structure of solid coke,tar and gas were investigated and the pyrolysis products were compared after characterization by infrared spectroscopy(FTIR)and gas chromatography-mass spectrometry(GC-MS).Results showed that DCLR was rapidly heated up to 900℃in 20 min with the maximum heating rate of 329℃·min-1 in the microwave field,while the heating rate of conventional heating was constant.Compared with conventional pyrolysis,coke yield decreased by 3%after microwave pyrolysis,whereas the tar and gas yields increased by 0.66%and 2.19%,respectively.After thepyrolysis of DCLR,the extracted compositions consisting of heavy oil(HS),as phaltene(A),and pre-asphaltene(PA)decreased significantly,while the contentof tetrahydrofuran insolubles(THFIS)increased.The Soxhlet compositions of thesolid coke did not evidently change compared with those after conventional pyrolysis,which indicated that the pyrolysis process of DCLR is mainly based on theconversion of HS,A and PA.After microwave pyrolysis,the intensity of the absorption peak at 3437.6,1632 and 1079.99 cm-1 on the infrared spectrumof the solid coke was significantly lower than that of conventional pyrolysis,which indicated that DCLR was more thoroughly pyrolyzed in the microwave field.Both tar and gas yields increased after pyrolysis,and the content of H 2 in gas reached above 60%.The results of GC-MS showed that no obvious change in thecomposition for aliphatics,aromatics,alcohol and the contents of C 1~5,C11~20 and C>20 in tar was observed after extraction with petroleum ether.The asphaltene content of tar decreased by 7.7%after microwave pyrolysis,which indicated that microwave pyrolysis can effectively promote asphaltene decomposition in DCLR,which benefited tar conversion to light fraction.
文摘该文使用文献计量学方法,分析了中国学术期刊全文数据库(CNKI)和Web of Science(WOS)两个数据库中中国灵长类文献的特征。结果表明,行为、进化和保护是当前中国灵长类研究的主要方向;中英文文献中,猕猴和仰鼻猴都是研究最多的类群,其中普通猕猴、金仰鼻猴和黑白仰鼻猴的研究成果最多;与类群相对应,秦岭、太行山、神农架和云南是主要的研究地点;从WOS数据库看,灵长类的研究成果体现了很好的国内外机构合作态势,但从CNKI数据库看,国内机构合作还有待加强。未来中国灵长类学发展建议着重以下几个方面:一致化物种中文命名,促进保护和提升研究影响;创新研究方法,开展长期生态监测,覆盖更多物种;加强野外调查,完善中国灵长类多样性和保护信息;加强合作研究。
文摘The title compound, (C33H42N4O12K)C6H2N3O7·H2O·CH3OH,Mr = 1003. 98,space group P1,a=11. 458(2) ,b= 14. 565(6) ,c=15. 828(3) A ;α=63. 34 (2),β=74. 06(1),γ=81. 03(2)°,V=2268. 1 A3;Z = 2,Dx = l. 47g/cm3,λ=0. 71069 A (MoKa).The final R = 0. 041 for 1700 observed reflections (I≥3σ(I)). The molecule is sandwich-like, and the cation K+ is sandwiched between the two crown rings.
基金the Science Challenge Project(No.TZ2018006-0201-01)National Natural Science Foundation of China(Nos.52035009,61635008).
文摘Atomic and close-to-atomic scale manufacturing is the key technology for the production of next-generation devices with atomic precision.As an important approach of mechanical processing,cutting has evolved as a potential candidate to generate an atomically smooth surface;thus,exploring its ultimate capability is significant.In this paper,single-crystal graphite,whose lattice structure and chemical bond property are of representation for demonstration,is selected to study the mechanism of atomic layer removal using molecular dynamics.A localized workpiece,which is dynamically updated on the basis of the tool position,is used to improve the computation efficiency.The principle and bullet points of this modeling method are first introduced,followed by a series of simulations under various undeformed chip thicknesses and tool edge radi.In addition,different potentials for the tool-workpiece interaction are tested,and the effect on the material response is presented.Based on the analysis of deformation,the number of carbon layers removed,and cutting forces,the chip formation mechanism and further understanding of the controllability of cutting at atomic and close-to-atomic scale can be achieved.
文摘The aim of this work is to investigate the dependence of Zn S thin films structural and optical properties with the solution flow rate during the deposition using an ultrasonic spray method. The solution flow rate ranged from 10 to 50 m L/h and the substrate temperature was maintained at 450 °C. The effect of the solution flow rate on the properties of Zn S thin films was investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, optical transmittance spectroscopy（UV–V） and the four-point method. The X-ray diffraction analysis showed that the deposited material was pure zinc sulphide, it has a cubic sphalerite structure with preferential orientation along the（111） direction. The grain size values were calculated and found to be between 38 to 82 nm.SEM analysis revealed that the deposited thin films have good adherence to the substrate surfaces, are homogeneous and have high density. The average transmission of all films is up more than 65% in the range wavelength from 200 to 1100 nm and their band gap energy values were found between 3.5–3.92 e V. The obtained film thickness varies from 390 to 1040 nm. Moreover, the electric resistivity of the deposited films increases with the increasing of the solution flow rate between 3.51 × 10^5 and 11 × 10^5 Ω·cm.
基金support from the National Natural Science Foundation of China(22205197)the Youth Talent Excellence Program of ZJU-Hangzhou Global Scientific and Technological Innovation Center.
文摘The study of luminescence phenomena in non-conjugated systems,namely clusteroluminescence,has gained significant attention for the development of advanced luminescent materials.While conventional strategies to manipulate the luminescent performances are based on complicated chemical reactions.In contrast,nature employs complexation to modulate luminescence,inspiring researchers to adopt an engineering approach for the construction of efficient clusteroluminogens.In this work,we explore the complexationinduced clusteroluminescence of carbonyl-based polymers with nitrogen-containing organic bases,exemplified by polyamide,polyester,polycarbonate,and poly(monothiocarbonate).
