Hepatitis B virus (HBV), a typical member of the Hepadnaviridae family, is responsible for infections that cause B-type hepatitis which leads to severe public health problems around the world. The small enveloped DNA-...Hepatitis B virus (HBV), a typical member of the Hepadnaviridae family, is responsible for infections that cause B-type hepatitis which leads to severe public health problems around the world. The small enveloped DNA-containing virus replicates via reverse transcription, and this unique process is accomplished by the virally encoded reverse transcriptase (RT). This multi-functional protein plays a vital role in the viral life cycle. Here, we provide a summary of current knowledge regarding the structural characteristics and molecular mechanisms of HBV RT. Improved understanding of these processes is of both theoretical and practical significance for fundamental studies of HBV and drug discovery.展开更多
Markedness Theory is one of the most important theories in structural linguistics. Its academic significance has long attracted more scholars and linguists. This paper intends to explore markedness from both formal an...Markedness Theory is one of the most important theories in structural linguistics. Its academic significance has long attracted more scholars and linguists. This paper intends to explore markedness from both formal and semantic perspectives： formal markedness, distributional markedness, and semantic markedness. These three types of markedness are accounted for in detail from their definitions to their characteristics. Then the relationship of these three types of markedness is explicated. The ultimate aim of this paper is to give an insight to markedness phenomenon not only from linguistic form or structure, but from its semantic distinctions and pragmatic use. The study also aims to help foster the greater application of Markedness Theory to other linguistic fields＇ study展开更多
In the present study,the thermal,mechanical,and biological properties of xAg/Ti-30Ta(x=0,0.41,0.82 and 2.48 at%)shape memory alloys(SMAs)were investigated.The study was conducted using optical and scanning electron mi...In the present study,the thermal,mechanical,and biological properties of xAg/Ti-30Ta(x=0,0.41,0.82 and 2.48 at%)shape memory alloys(SMAs)were investigated.The study was conducted using optical and scanning electron microscopy(SEM),X-ray diffractometry(XRD),compression test,and shape memory testing.The xAg/Ti-Ta was made using a powder metallurgy technique and microwave-sintering process.The results revealed that the addition of Ag has a significant effect on the pore size and shape,whereas the smallest pore size of 11μm was found with the addition of 0.41 at%along with a relative density of 72%.The fracture stress and strain increased with the addition of Ag,reaching the minimum values around 0.41 at%Ag.Therefore,this composition showed the maximum stress and strain at fracture region.Moreover,0.82 Ag/Ti-Ta shows more excellent corrosion resistance and biocompatibility than other percentages,obtaining almost the same behaviour of the pure Ti and Ti-6Al-4V alloys,which can be recommended for their promising and potential response for biomaterial applications.展开更多
With the point source dislocation model and the velocity structure of a layered medium,focal mechanisms of small earthquakes are calculated using the maximum amplitude of the direct P- and S-waves in the vertical comp...With the point source dislocation model and the velocity structure of a layered medium,focal mechanisms of small earthquakes are calculated using the maximum amplitude of the direct P- and S-waves in the vertical component. By system clustering,and using the vector synthesis method,the average focal mechanism solution is obtained. Using the above method,this paper analyzes the variation characteristics of the source ruptures and the P-axis azimuths of small earthquakes around the seismic zones before four strong earthquakes occurring since 2003 in the western part of north Tianshan and the middle part of Tianshan. The result shows that 2 ~ 3 years before the strong earthquakes,the focal mechanism types of small earthquakes are distributed randomly, and obvious dominant distributions are observed one year before the strong earthquakes. There are obvious changes in the P-axis azimuth.展开更多
The article presents the results of study of composition, structure and properties of three genetic types of serpentinite, developed by chromite-bearing ultrabasic rocks, by metamorphic zones of carbonate rocks and wi...The article presents the results of study of composition, structure and properties of three genetic types of serpentinite, developed by chromite-bearing ultrabasic rocks, by metamorphic zones of carbonate rocks and within the zone of weathering of ultrabasic rocks. The samples were selected from deposits, located along the Main Ural Fault-the Paleozoic subduction zone （named GUR）. Peculiarities of microstructure, chemical composition and properties of serpentinites formed in different geological conditions were investigated and their comparative study was held. They were devided three groups of serpentinites with oriented and non-oriented structure which formed by different protholites： mantle, lithosphere and crust.展开更多
The earthquake characteristics and geological structure of the site to sitting the Qinshan Nuclear Power Station are closely related. According to site investigation drilling, sampling, seismic sound logging wave test...The earthquake characteristics and geological structure of the site to sitting the Qinshan Nuclear Power Station are closely related. According to site investigation drilling, sampling, seismic sound logging wave test in single-hole and cross-hole, laboratory wave velocity test of intact rock, together with analysis of the site geological conditions, the seismic wave test results of the site between strata lithology and the geologic structure were studied. The relationships of seismic waves with the site lithology and the geologic structure were set up. The dynamic parameters of different grades of weathering profile were deduced. The results assist the seismic design of Phase Ⅲ Qinshan Nuclear Power Plant, China.展开更多
基金National Nature Science Foundations of China (30870131)Program of Chinese Academy of Sciences (0802021SA1)
文摘Hepatitis B virus (HBV), a typical member of the Hepadnaviridae family, is responsible for infections that cause B-type hepatitis which leads to severe public health problems around the world. The small enveloped DNA-containing virus replicates via reverse transcription, and this unique process is accomplished by the virally encoded reverse transcriptase (RT). This multi-functional protein plays a vital role in the viral life cycle. Here, we provide a summary of current knowledge regarding the structural characteristics and molecular mechanisms of HBV RT. Improved understanding of these processes is of both theoretical and practical significance for fundamental studies of HBV and drug discovery.
文摘Markedness Theory is one of the most important theories in structural linguistics. Its academic significance has long attracted more scholars and linguists. This paper intends to explore markedness from both formal and semantic perspectives： formal markedness, distributional markedness, and semantic markedness. These three types of markedness are accounted for in detail from their definitions to their characteristics. Then the relationship of these three types of markedness is explicated. The ultimate aim of this paper is to give an insight to markedness phenomenon not only from linguistic form or structure, but from its semantic distinctions and pragmatic use. The study also aims to help foster the greater application of Markedness Theory to other linguistic fields＇ study
基金Project(Q.J130000.2524.12H60)supported by the Ministry of Higher Education of Malaysia and Universiti Teknologi Malaysia。
文摘In the present study,the thermal,mechanical,and biological properties of xAg/Ti-30Ta(x=0,0.41,0.82 and 2.48 at%)shape memory alloys(SMAs)were investigated.The study was conducted using optical and scanning electron microscopy(SEM),X-ray diffractometry(XRD),compression test,and shape memory testing.The xAg/Ti-Ta was made using a powder metallurgy technique and microwave-sintering process.The results revealed that the addition of Ag has a significant effect on the pore size and shape,whereas the smallest pore size of 11μm was found with the addition of 0.41 at%along with a relative density of 72%.The fracture stress and strain increased with the addition of Ag,reaching the minimum values around 0.41 at%Ag.Therefore,this composition showed the maximum stress and strain at fracture region.Moreover,0.82 Ag/Ti-Ta shows more excellent corrosion resistance and biocompatibility than other percentages,obtaining almost the same behaviour of the pure Ti and Ti-6Al-4V alloys,which can be recommended for their promising and potential response for biomaterial applications.
基金funded as a sub-project under the National Science and Technology Pillar Program of China(2006BAC01B03-04-02)
文摘With the point source dislocation model and the velocity structure of a layered medium,focal mechanisms of small earthquakes are calculated using the maximum amplitude of the direct P- and S-waves in the vertical component. By system clustering,and using the vector synthesis method,the average focal mechanism solution is obtained. Using the above method,this paper analyzes the variation characteristics of the source ruptures and the P-axis azimuths of small earthquakes around the seismic zones before four strong earthquakes occurring since 2003 in the western part of north Tianshan and the middle part of Tianshan. The result shows that 2 ~ 3 years before the strong earthquakes,the focal mechanism types of small earthquakes are distributed randomly, and obvious dominant distributions are observed one year before the strong earthquakes. There are obvious changes in the P-axis azimuth.
文摘The article presents the results of study of composition, structure and properties of three genetic types of serpentinite, developed by chromite-bearing ultrabasic rocks, by metamorphic zones of carbonate rocks and within the zone of weathering of ultrabasic rocks. The samples were selected from deposits, located along the Main Ural Fault-the Paleozoic subduction zone （named GUR）. Peculiarities of microstructure, chemical composition and properties of serpentinites formed in different geological conditions were investigated and their comparative study was held. They were devided three groups of serpentinites with oriented and non-oriented structure which formed by different protholites： mantle, lithosphere and crust.
文摘The earthquake characteristics and geological structure of the site to sitting the Qinshan Nuclear Power Station are closely related. According to site investigation drilling, sampling, seismic sound logging wave test in single-hole and cross-hole, laboratory wave velocity test of intact rock, together with analysis of the site geological conditions, the seismic wave test results of the site between strata lithology and the geologic structure were studied. The relationships of seismic waves with the site lithology and the geologic structure were set up. The dynamic parameters of different grades of weathering profile were deduced. The results assist the seismic design of Phase Ⅲ Qinshan Nuclear Power Plant, China.
