Previous investigations have shown that the seismic response of slopes during the Wenchuan earthquake was highly variable. The present study tries to give an answer to the question： Which are the main factors affecti...Previous investigations have shown that the seismic response of slopes during the Wenchuan earthquake was highly variable. The present study tries to give an answer to the question： Which are the main factors affecting the seismic response degree of slopes？ With the support of the China Geological Survey Bureau, we set 3 monitoring sections in Jiulong slope, Mianzhu city, China with the aim to record the site response of the slope during the affershoeks of the Wenehuan earthquake. After the Wenchuan earthquake, which happened on 12 May 2008, 30 aftershocks have been recorded in these monitoring points. We analyzed 11 records, with magnitudes ranging from ML = 4.6 to ML = 3.1. The amplification factors of the horizontal compound PGA and 3D compound PGA have been determined for the 3 points at different elevations on the slope. Results showed that the dynamic response of the slope on the earthquake was controlled by factors such as topography and the thickness of the Quaternary overburden.展开更多
This paper focuses on exporting relational data into extensible markup language (XML). First, the characteristics of both relational schemas represented by E-R diagrams and XML document type definitions (DTDs) are an...This paper focuses on exporting relational data into extensible markup language (XML). First, the characteristics of both relational schemas represented by E-R diagrams and XML document type definitions (DTDs) are analyzed. Secondly, the corresponding mapping rules are proposed. At last an algorithm based on edge tables is presented. There are two key points in the algorithm. One is that the edge table is used to store the information of the relational dictionary, and this brings about the efficiency of the algorithm. The other is that structural information can be obtained from the resulting DTDs and other applications can optimize their query processes using the structural information.展开更多
Fouling diatoms are a main component of biofilm,and play an important role in marine biofouling formation. We investigated seasonal variations in fouling diatom communities that developed on glass slides immersed in s...Fouling diatoms are a main component of biofilm,and play an important role in marine biofouling formation. We investigated seasonal variations in fouling diatom communities that developed on glass slides immersed in seawater,on the Yantai coast,northern Yellow Sea,China,using microscopy and molecular techniques. Studies were conducted during 2012 and 2013 over 3,7,14,and 21 days in each season. The abundance of attached diatoms and extracellular polymeric substances increased with exposure time of the slides to seawater. The lowest diatom density appeared in winter and the highest species richness and diversity were found in summer and autumn. Seasonal variation was observed in the structure of fouling diatom communities. Pennate diatoms Cylindrotheca,Nitzschia,Navicula,Amphora,Gomphonema,and Licmophora were the main fouling groups. Cylindrotheca sp. dominated in the spring. Under laboratory culture conditions,we found that Cylindrotheca grew very fast,which might account for the highest density of this diatom in spring. The lower densities in summer and autumn might result from the emergence of fouling animals and environmental factors. The Cylindrotheca sp. was identified as Cylindrotheca closterium using18 S rDNA sequencing. The colonization process of fouling diatoms and significant seasonal variation in this study depended on environmental and biological factors. Understanding the basis of fouling diatoms is essential and important for developing new antifouling techniques.展开更多
Efficient lookup is essential for peer-to-peer networks and Chord is a representative peer-to-peer lookup scheme based on distributed hash table (DHT). In peer-to-peer networks, each node maintains several unidirectio...Efficient lookup is essential for peer-to-peer networks and Chord is a representative peer-to-peer lookup scheme based on distributed hash table (DHT). In peer-to-peer networks, each node maintains several unidirectional application layer links to other nodes and forwards lookup messages through such links. This paper proposes use of bidirectional links to improve the lookup performance in Chord. Every original unidirectional link is replaced by a bidirectional link, and accordingly every node becomes an anti-finger of all its finger nodes. Both theoretical analyses and experimental results indicate that these anti-fingers can help improve the lookup performance greatly with very low overhead.展开更多
In order to monitor the deformations of modern constructions a local 3D network was usually being established at the surrounding area. The centering error, of both the instrument and targets, causes significant uncert...In order to monitor the deformations of modern constructions a local 3D network was usually being established at the surrounding area. The centering error, of both the instrument and targets, causes significant uncertainties in the determination of the x, y, z coordinates of the network＇s points. In order to assure precise centering for both the instrument and targets, not only for the accessible but also for the inaccessible network＇s points, a prototype way of marking is being implied. A special semi-permanent portable metallic stand （Photo 1） was manufactured for marking the accessible points. The stand provides forced instrument centering of the order of_＋0, lmm. It is light enough to carry, it accelerates and facilitates the centering and leveling of the instrument as well as it eliminates the time needed for the measurements. The applied laboratory checks in order to certify the suitability of its use and the provided accuracy are being described. For the inaccessible points special targets were used. The targets were put in permanent attachments （Photos 7-8）, which were also manufactured. Useful conclusions were drawn when these special accessories were used in to a 3D network, which was established for the monitoring of a new football stadium. Two measurement phases were carried out. The first one is with the stadium empty and the second one is when it was crowded （about 32000 people） during a significant football match.展开更多
Adsorption is one of the most widely applied techniques for environmental remediation. Its kinetics are of great significance to evaluate the performance of a given adsorbent and gain insight into the underlying mecha...Adsorption is one of the most widely applied techniques for environmental remediation. Its kinetics are of great significance to evaluate the performance of a given adsorbent and gain insight into the underlying mechanisms. There are lots of references available concerning adsorption kinetics, and several mathematic models have been developed to describe adsorption reaction and diffusion processes. However, these models were frequently employed to fit the kinetic data in an unsuitable or improper manner. This is mainly because the boundary conditions of the associated models were, to a considerable extent, ignored for data modeling. Here we reviewed several widely-used adsorption kinetic models and paid more attention to their boundary conditions. We believe that the review is of certain significance and improvement for adsorption kinetic modeling.展开更多
Boundary layer separation and reattachment is often an unavoidable feature of low pressure (LP) turbine,one of the main causes of this phenomenon is the high altitude low Reynolds number experienced by the modern LP t...Boundary layer separation and reattachment is often an unavoidable feature of low pressure (LP) turbine,one of the main causes of this phenomenon is the high altitude low Reynolds number experienced by the modern LP turbine stage in aero-engine.Although an excellent turbine airfoil design can avoid flow separation on certain extent,but within flight envelope,LP turbine's characteristic Reynolds number may varied greatly,so it will be still under the risk of the presence of separation bubble.In this two parts paper a new concept of slotted-blade was raised to testify the gain of the blade slotting.A high aerodynamic loading LP turbine blade IET-LPTA was under investigated with different Reynolds number.Computational results reveal that the blade slotting could be a way of choice to suppress separation bubble and reduce profile loss under the condition of low Reynolds number,although its position and geometry need to be further investigated.展开更多
基金supported by National Natural Science Foundation of China (Grant No.41072231)China Geological Survey Bureau (Grant Nos 1212010914010 and 1212011220154)Program for Changjiang Scholars and Innovative Research Team in University" (Grant No. IRT0812)
文摘Previous investigations have shown that the seismic response of slopes during the Wenchuan earthquake was highly variable. The present study tries to give an answer to the question： Which are the main factors affecting the seismic response degree of slopes？ With the support of the China Geological Survey Bureau, we set 3 monitoring sections in Jiulong slope, Mianzhu city, China with the aim to record the site response of the slope during the affershoeks of the Wenehuan earthquake. After the Wenchuan earthquake, which happened on 12 May 2008, 30 aftershocks have been recorded in these monitoring points. We analyzed 11 records, with magnitudes ranging from ML = 4.6 to ML = 3.1. The amplification factors of the horizontal compound PGA and 3D compound PGA have been determined for the 3 points at different elevations on the slope. Results showed that the dynamic response of the slope on the earthquake was controlled by factors such as topography and the thickness of the Quaternary overburden.
文摘This paper focuses on exporting relational data into extensible markup language (XML). First, the characteristics of both relational schemas represented by E-R diagrams and XML document type definitions (DTDs) are analyzed. Secondly, the corresponding mapping rules are proposed. At last an algorithm based on edge tables is presented. There are two key points in the algorithm. One is that the edge table is used to store the information of the relational dictionary, and this brings about the efficiency of the algorithm. The other is that structural information can be obtained from the resulting DTDs and other applications can optimize their query processes using the structural information.
基金Supported by the National Natural Science Foundation of China(No.41206154)the Yantai Science and Technology Development Project(No.2011063)the National Marine Project(No.XDA11020403)
文摘Fouling diatoms are a main component of biofilm,and play an important role in marine biofouling formation. We investigated seasonal variations in fouling diatom communities that developed on glass slides immersed in seawater,on the Yantai coast,northern Yellow Sea,China,using microscopy and molecular techniques. Studies were conducted during 2012 and 2013 over 3,7,14,and 21 days in each season. The abundance of attached diatoms and extracellular polymeric substances increased with exposure time of the slides to seawater. The lowest diatom density appeared in winter and the highest species richness and diversity were found in summer and autumn. Seasonal variation was observed in the structure of fouling diatom communities. Pennate diatoms Cylindrotheca,Nitzschia,Navicula,Amphora,Gomphonema,and Licmophora were the main fouling groups. Cylindrotheca sp. dominated in the spring. Under laboratory culture conditions,we found that Cylindrotheca grew very fast,which might account for the highest density of this diatom in spring. The lower densities in summer and autumn might result from the emergence of fouling animals and environmental factors. The Cylindrotheca sp. was identified as Cylindrotheca closterium using18 S rDNA sequencing. The colonization process of fouling diatoms and significant seasonal variation in this study depended on environmental and biological factors. Understanding the basis of fouling diatoms is essential and important for developing new antifouling techniques.
文摘Efficient lookup is essential for peer-to-peer networks and Chord is a representative peer-to-peer lookup scheme based on distributed hash table (DHT). In peer-to-peer networks, each node maintains several unidirectional application layer links to other nodes and forwards lookup messages through such links. This paper proposes use of bidirectional links to improve the lookup performance in Chord. Every original unidirectional link is replaced by a bidirectional link, and accordingly every node becomes an anti-finger of all its finger nodes. Both theoretical analyses and experimental results indicate that these anti-fingers can help improve the lookup performance greatly with very low overhead.
文摘In order to monitor the deformations of modern constructions a local 3D network was usually being established at the surrounding area. The centering error, of both the instrument and targets, causes significant uncertainties in the determination of the x, y, z coordinates of the network＇s points. In order to assure precise centering for both the instrument and targets, not only for the accessible but also for the inaccessible network＇s points, a prototype way of marking is being implied. A special semi-permanent portable metallic stand （Photo 1） was manufactured for marking the accessible points. The stand provides forced instrument centering of the order of_＋0, lmm. It is light enough to carry, it accelerates and facilitates the centering and leveling of the instrument as well as it eliminates the time needed for the measurements. The applied laboratory checks in order to certify the suitability of its use and the provided accuracy are being described. For the inaccessible points special targets were used. The targets were put in permanent attachments （Photos 7-8）, which were also manufactured. Useful conclusions were drawn when these special accessories were used in to a 3D network, which was established for the monitoring of a new football stadium. Two measurement phases were carried out. The first one is with the stadium empty and the second one is when it was crowded （about 32000 people） during a significant football match.
基金supported by the National Natural Science Foundation of China (No. 20504012)the New Century Excellent Talents in University of China (No. NCET-07-0421)
文摘Adsorption is one of the most widely applied techniques for environmental remediation. Its kinetics are of great significance to evaluate the performance of a given adsorbent and gain insight into the underlying mechanisms. There are lots of references available concerning adsorption kinetics, and several mathematic models have been developed to describe adsorption reaction and diffusion processes. However, these models were frequently employed to fit the kinetic data in an unsuitable or improper manner. This is mainly because the boundary conditions of the associated models were, to a considerable extent, ignored for data modeling. Here we reviewed several widely-used adsorption kinetic models and paid more attention to their boundary conditions. We believe that the review is of certain significance and improvement for adsorption kinetic modeling.
基金provided by the Supercomputing Center of Chinese Academy of Sciences and the National Natural Science Foundation of China’s sponsorship
文摘Boundary layer separation and reattachment is often an unavoidable feature of low pressure (LP) turbine,one of the main causes of this phenomenon is the high altitude low Reynolds number experienced by the modern LP turbine stage in aero-engine.Although an excellent turbine airfoil design can avoid flow separation on certain extent,but within flight envelope,LP turbine's characteristic Reynolds number may varied greatly,so it will be still under the risk of the presence of separation bubble.In this two parts paper a new concept of slotted-blade was raised to testify the gain of the blade slotting.A high aerodynamic loading LP turbine blade IET-LPTA was under investigated with different Reynolds number.Computational results reveal that the blade slotting could be a way of choice to suppress separation bubble and reduce profile loss under the condition of low Reynolds number,although its position and geometry need to be further investigated.
