The previous work found that the additive kaolin could scavenge not only sodium(Na)but also calcium(Ca)and magnesium(Mg),which is the important ash fluxing agents in low rank coal combustion.Such scavenging effects of...The previous work found that the additive kaolin could scavenge not only sodium(Na)but also calcium(Ca)and magnesium(Mg),which is the important ash fluxing agents in low rank coal combustion.Such scavenging effects of kaolin on fine ash formation were studied in the present work.A typical Zhundong coal and its blends with kaolin at dosages of 1,2 and 4 wt%were combusted in an electrically heated drop tube furnace(DTF)at 1300℃.The fine ashes generated were collected and size segregated by a low pressure impactor(LPI).The morphology and chemical composition of fine ash were analyzed by scanning electron microscopy equipped with an energydispersive spectrometer(SEM-EDS).In addition,char/ash particles were sampled at various positions of DTF to elucidate how kaolin additive affected the fine ash formation process.The results further showed that apart from the scavenging of volatile Na,kaolin additive could also strongly scavenge the refractory Ca,Mg and Fe in the fine ash during Zhundong coal combustion,which transformed the sintered particles with irregular shape into melted spherical particles,and finally resulted in the considerable decrease of these elements in both PM_(0.4)and PM_(0.4-10)by melting and agglomeration.The close contacts between kaolin particles and coal resulted from physically mixing were a key factor responsible for the reaction of kaolin with the refractory Ca,Mg and Fe.展开更多
This paper deals with a new integrated method of reconstruction and forecasting of climatic changes in future. The method is based on proxy data pollen-spore analysis method, 14C analysis method, nowadays meteorologic...This paper deals with a new integrated method of reconstruction and forecasting of climatic changes in future. The method is based on proxy data pollen-spore analysis method, 14C analysis method, nowadays meteorological data, and data about of solar activity expressed in numbers of W (Wolf). Here we present the results of investigation of sediments of the 2nd Fomich River terrace, Taymyr Peninsula, Russia. The formation of the peat bog started 10500 ± 140 years BP and continued during the entire Holocene. The pollen analysis of the sediment samples of the 2nd Fomich River terrace and the analysis of surface samples from a larch forest, typical of this region, reveals two phytochrones: both climatically preconditioned--tundra phytochrone (I1-4) and forest phytochrone (Ⅱ1-4). The techniques of reconstruction and forecasting of basic elements of climate are presented and discussed in details.展开更多
Seeking for innovative structures with higher mechanical performance is a continuous target in railway vehicle crashworthiness design.In the present study,three types of hexagonal reinforced honeycomb-like structures ...Seeking for innovative structures with higher mechanical performance is a continuous target in railway vehicle crashworthiness design.In the present study,three types of hexagonal reinforced honeycomb-like structures were developed and analyzed subjected to out-of-plane compression,namely triangular honeycomb(TH),double honeycomb(DH)and full inside honeycomb(FH).Theoretical formulas of average force and specific energy absorption(SEA)were constructed based on the energy minimization principle.To validate,corresponding numerical simulations were carried out by explicit finite element method.Good agreement has been observed between them.The results show that all these honeycomb-like structures maintain the same collapsed stages as conventional honeycomb;cell reinforcement can significantly promote the performance,both in the average force and SEA;full inside honeycomb performs better than the general,triangular and double schemes in average force;meanwhile,its SEA is close to that of double scheme;toroidal surface can dissipate higher plastic energy,so more toroidal surfaces should be considered in design of thin-walled structure.These achievements pave a way for designing high-performance cellular energy absorption devices.展开更多
Objective: To investigate the effects of basic transcriptional element binding protein-2 (BTEB2) antisense RNA on vascular smooth muscle cells (VSMCs) proliferation and the neointimal formation after carotid ball...Objective: To investigate the effects of basic transcriptional element binding protein-2 (BTEB2) antisense RNA on vascular smooth muscle cells (VSMCs) proliferation and the neointimal formation after carotid balloon injury in rats. Methods: The cultured VSMCs were transfected with an adenoviral vector containing BTEB2 antisense gene, Ad ASBTEB2. Effects of BTEB2 antisense RNA on the expression of BTEB2 were investigated by Western blot analysis. The cell cycle was analyzed using flow cytometry. Ad ASBTEB2, control adenoviral vector Ad. LacZ or PBS was transduced into the rat carotid artery after balloon injury. The expression of BTEB2 at 7, 14, and 21 d after gene transfer was detected by immunohistochemistry and neointima-to-media (I/M) area ratio at these time points was calculated. Resuits: The cell cycle was arrested in G0/G1 phase and the expression of BETB2 was downregulated after transfection with Ad ASBTEB2. Ad ASBTEB2 treatment reduced I/M area ratios on day 7, 14, and 21 after injury by 45%, 50% and 53% respectively, whereas the Ad LacZ treatment did not significantly alter these ratios compared with control group. Conclusion: BTEB2 antisense RNA mediated by adenoviral vector inhibits proliferation of VSMCs and significantly reduces neointimal hyperplasia in the rat carotid balloon injury model. BTEB2 antisense RNA is a potential therapeutic approach to preventing neointimal formation after balloon injury.展开更多
The idea of mineral exploration,which is called"exploration philosophy"in the Western countries,is the thoughts,the methodology,technology,goals and organization that guide mineral exploration.The three basi...The idea of mineral exploration,which is called"exploration philosophy"in the Western countries,is the thoughts,the methodology,technology,goals and organization that guide mineral exploration.The three basic elements of mineral exploration are"what to find","where to find"and"how to find".The concept of mineral exploration is gradually changing with the development of these three elements that provide a powerful driving force to change mineral exploration concepts,methods and technology.Innovation of mineral exploration concepts is the result of continuing exploration and development keeping pace with the times.The combination of"mathematical geology"and"information technology"can be called"digital geology".Digital geology is the data analysis component of geological science.Geological data science is a science that uses the general methodology of data to study geology based on the characteristics of geological data and the needs of geological field work.Digital mineral exploration is the application of digital geology in mineral exploration to reduce ore-finding uncertainty.展开更多
基金the National Key Research and Development Program of China(No.2016YFB0600601)National Natural Science Foundation of China(Nos.51676075 and 51520105008).
文摘The previous work found that the additive kaolin could scavenge not only sodium(Na)but also calcium(Ca)and magnesium(Mg),which is the important ash fluxing agents in low rank coal combustion.Such scavenging effects of kaolin on fine ash formation were studied in the present work.A typical Zhundong coal and its blends with kaolin at dosages of 1,2 and 4 wt%were combusted in an electrically heated drop tube furnace(DTF)at 1300℃.The fine ashes generated were collected and size segregated by a low pressure impactor(LPI).The morphology and chemical composition of fine ash were analyzed by scanning electron microscopy equipped with an energydispersive spectrometer(SEM-EDS).In addition,char/ash particles were sampled at various positions of DTF to elucidate how kaolin additive affected the fine ash formation process.The results further showed that apart from the scavenging of volatile Na,kaolin additive could also strongly scavenge the refractory Ca,Mg and Fe in the fine ash during Zhundong coal combustion,which transformed the sintered particles with irregular shape into melted spherical particles,and finally resulted in the considerable decrease of these elements in both PM_(0.4)and PM_(0.4-10)by melting and agglomeration.The close contacts between kaolin particles and coal resulted from physically mixing were a key factor responsible for the reaction of kaolin with the refractory Ca,Mg and Fe.
文摘This paper deals with a new integrated method of reconstruction and forecasting of climatic changes in future. The method is based on proxy data pollen-spore analysis method, 14C analysis method, nowadays meteorological data, and data about of solar activity expressed in numbers of W (Wolf). Here we present the results of investigation of sediments of the 2nd Fomich River terrace, Taymyr Peninsula, Russia. The formation of the peat bog started 10500 ± 140 years BP and continued during the entire Holocene. The pollen analysis of the sediment samples of the 2nd Fomich River terrace and the analysis of surface samples from a larch forest, typical of this region, reveals two phytochrones: both climatically preconditioned--tundra phytochrone (I1-4) and forest phytochrone (Ⅱ1-4). The techniques of reconstruction and forecasting of basic elements of climate are presented and discussed in details.
基金Projects(51875581,51505502)supported by the National Natural Science Foundation of ChinaProjects(2017M620358,2018T110707)supported by China Postdoctoral Science FoundationProject(kq1905057)supported by the Training Program for Excellent Young Innovators of Changsha,China
文摘Seeking for innovative structures with higher mechanical performance is a continuous target in railway vehicle crashworthiness design.In the present study,three types of hexagonal reinforced honeycomb-like structures were developed and analyzed subjected to out-of-plane compression,namely triangular honeycomb(TH),double honeycomb(DH)and full inside honeycomb(FH).Theoretical formulas of average force and specific energy absorption(SEA)were constructed based on the energy minimization principle.To validate,corresponding numerical simulations were carried out by explicit finite element method.Good agreement has been observed between them.The results show that all these honeycomb-like structures maintain the same collapsed stages as conventional honeycomb;cell reinforcement can significantly promote the performance,both in the average force and SEA;full inside honeycomb performs better than the general,triangular and double schemes in average force;meanwhile,its SEA is close to that of double scheme;toroidal surface can dissipate higher plastic energy,so more toroidal surfaces should be considered in design of thin-walled structure.These achievements pave a way for designing high-performance cellular energy absorption devices.
文摘Objective: To investigate the effects of basic transcriptional element binding protein-2 (BTEB2) antisense RNA on vascular smooth muscle cells (VSMCs) proliferation and the neointimal formation after carotid balloon injury in rats. Methods: The cultured VSMCs were transfected with an adenoviral vector containing BTEB2 antisense gene, Ad ASBTEB2. Effects of BTEB2 antisense RNA on the expression of BTEB2 were investigated by Western blot analysis. The cell cycle was analyzed using flow cytometry. Ad ASBTEB2, control adenoviral vector Ad. LacZ or PBS was transduced into the rat carotid artery after balloon injury. The expression of BTEB2 at 7, 14, and 21 d after gene transfer was detected by immunohistochemistry and neointima-to-media (I/M) area ratio at these time points was calculated. Resuits: The cell cycle was arrested in G0/G1 phase and the expression of BETB2 was downregulated after transfection with Ad ASBTEB2. Ad ASBTEB2 treatment reduced I/M area ratios on day 7, 14, and 21 after injury by 45%, 50% and 53% respectively, whereas the Ad LacZ treatment did not significantly alter these ratios compared with control group. Conclusion: BTEB2 antisense RNA mediated by adenoviral vector inhibits proliferation of VSMCs and significantly reduces neointimal hyperplasia in the rat carotid balloon injury model. BTEB2 antisense RNA is a potential therapeutic approach to preventing neointimal formation after balloon injury.
基金funded by the National Key Research and Development Project of China(No.2016YFC0600509)the National Natural Science Foundation of China(Nos.41972312,41672329)the Project of China Geological Survey(No.1212011120341)。
文摘The idea of mineral exploration,which is called"exploration philosophy"in the Western countries,is the thoughts,the methodology,technology,goals and organization that guide mineral exploration.The three basic elements of mineral exploration are"what to find","where to find"and"how to find".The concept of mineral exploration is gradually changing with the development of these three elements that provide a powerful driving force to change mineral exploration concepts,methods and technology.Innovation of mineral exploration concepts is the result of continuing exploration and development keeping pace with the times.The combination of"mathematical geology"and"information technology"can be called"digital geology".Digital geology is the data analysis component of geological science.Geological data science is a science that uses the general methodology of data to study geology based on the characteristics of geological data and the needs of geological field work.Digital mineral exploration is the application of digital geology in mineral exploration to reduce ore-finding uncertainty.