Iranian traditional architecture can be identified in many of its old famous buildings in the country. The principles and specifications in these buildings show the intelligence of implemented techniques that makes th...Iranian traditional architecture can be identified in many of its old famous buildings in the country. The principles and specifications in these buildings show the intelligence of implemented techniques that makes them to remain stable. Thus, it is important to explore the traditional structures and architectural technologies in order to understand the reasons for this stability toward the new methods in modem architecture. Many of historical buildings in Iran have remained standing after many years and they show the deep wisdom of their architects. The purpose of this article is studying the various aspects of traditional structure and integration between this well-oriented structure and architecture. For reaching this goal, we refer to Tekye-Amir-Chakhmagh in Yazd as our case study, which is one of the most important and noticeable examples of Iranian traditional architecture. By introducing Amir-Chakhmagh Complex, we analyzed the specifications and fundamental elements that played an important role in stability and sustainability of Tekye-Amir-Chakhmagh and thereafter, we assessed the technologies that were used intelligently and intricately in this historical building. In this research, information is collected with field study and library resources. Finally, qualities and characteristics of the structure are studied by drawings and structural analysis and as conclusion, the suggestions and guidelines are presented.展开更多
Language, literature, customs and traditions, music and art are cultural items that were transmitted from generation to generation throughout history. In this context, literature is an important source of music cultur...Language, literature, customs and traditions, music and art are cultural items that were transmitted from generation to generation throughout history. In this context, literature is an important source of music culture that takes inspiration from the customs and traditions of a society. Prosodic meter is echoed in form, usul and general structure in works composed from the divan literature and almost lives in the work. In the same way, when examples of folk literature composed by composers and performed by poets and a^lks are examined, it is observed that there are parallels between literary features and form, structure and rhythmic features. The aim of this paper is to reveal the integral link between Melody-Usul and Meter in Ottoman Turkish Music展开更多
The concept of "real man" is the historical origin and the logical starting point in The Marx's Materialist Conception of History, and is also our basic starting point in the social science research. Although our c...The concept of "real man" is the historical origin and the logical starting point in The Marx's Materialist Conception of History, and is also our basic starting point in the social science research. Although our country's social security system has made great development and progress, but it still does not adapts the level of economy development, especially compared with the requirements of the people. Based on the principle of Marx's "real man" theory and combine the "real man" with the "people oriented", this article discussed the basic framework of the present social security system and its shortcomings in China. Then I try to put forward suggestions from breaking the urban-rural dual structure, gradually establishing urban and rural areas as a whole one of social security system, actively expanding the social security fund financing channels, establishing a nationwide unified social security of personal accounts, strive to establish a "people oriented" social security system.展开更多
Near 50 years history of the development of radioisotope neutron sources in China is briefly reviewed.The structure design,preparing technology and production status of routine neutron sources including 210Po-Be sourc...Near 50 years history of the development of radioisotope neutron sources in China is briefly reviewed.The structure design,preparing technology and production status of routine neutron sources including 210Po-Be sources,210Po mock fission sources,241Am-Be sources,238Pu-Be sources,252Cf spontaneous fission sources and other special-shape neutron sources are summarized.In addition,the prospects of development on radioisotope neutron source in China are predicted from the needs of nuclear power construction,oil well-logging,neutron moisture gauge and neutron brachytherapy.展开更多
With the continuous development of political, economic,social, empty nesters and more problems, it is not a simple personal issues, has become urgent to break the social proposition.This paper intr~,duces the concepts...With the continuous development of political, economic,social, empty nesters and more problems, it is not a simple personal issues, has become urgent to break the social proposition.This paper intr~,duces the concepts at the same time,Further analysis of the current situation empty-nesters of the problem and sort out the history of urban-rural dual structure,Finally, find information put forward some countermeasures and suggestions.展开更多
The objective of this paper is to study the influence of repeated variable action on long-term behavior of concrete structural elements using quasi-permanent combination of actions, for the assessment of long-term eff...The objective of this paper is to study the influence of repeated variable action on long-term behavior of concrete structural elements using quasi-permanent combination of actions, for the assessment of long-term effects (e.g., effects due to creep and shrinkage in concrete structures), as it is proposed in Eurocodes. Extensive experimental program and analytical research using model B3 and AAEM (age adjusted effective modulus) method was performed in order to define quasi-permanent factor ψ2, for two specific loading histories. These loading histories were consist of long-term permanent action "G" and repeated variable action "Q". The variable load was applied in cycles of loading/unloading for 24 h and 48 h in period of 400 days appropriately for one series of concrete elements. 24 reinforced concrete beams, dimensions 150 mm × 280 mm × 3,000 mm, were tested. Twelve beams were made of concrete class C30/37 and 12 of concrete class C60/75.展开更多
It is a very hard job for historians to keep themselves neutrals in from of the events they find during their studies. It is also difficult to notice the correlations among the different times of the history without f...It is a very hard job for historians to keep themselves neutrals in from of the events they find during their studies. It is also difficult to notice the correlations among the different times of the history without falling in anachronistic mistakes. In fact, it is well-known that a historian must be wise and rational when he finds those correlations, because every society has its own characteristics, structures, and mentality. This brief essay focuses on the social structures in a north eastern italic region, which is called Friuli, between the 12th and 16th centuries. In the above mentioned centuries, it is possible to notice an evolution from a feudal ecclesiastical principality, ruled by prince-patriarchs, ecclesiastical institutions and nobility, to a more fluid and dynamic constitution formed by new classes which rose up in times of urban and economic development. But this development struggles to delete the old system, which persisted until the end of 18th century with the arrival of Napoleon. The transition from the Patriarch's power to Venice's dominion seems to have created two main consequences: by one hand a more bureaucratic and modem structure of the State, by the other hand a consolidation of the old connections between patrons and clients, consequence of the "modem" feudal system that consolidated its roots in the Late Middle Ages centuries.展开更多
This paperprovides a historical overview intending to clarify the methods of interpretation of timber-framed buildings by different authors of construction treatises, and structural intentions of the carpentry designe...This paperprovides a historical overview intending to clarify the methods of interpretation of timber-framed buildings by different authors of construction treatises, and structural intentions of the carpentry designers and master builders, throughout the centuries, until the period when it became scientific structural theory. It describes the "box-frame" construction that appeared in Lisbon, after the earthquake of 1755, characterized by its good seismic resistance. This knowledge is important to determine a strategy of an efficient restoration practice in historical constructions which require an intervention subordinated to its raised patrimonial and artistic value, minimum, which respects the authenticity of its structural and construction conception and which is reversible and compatible, in physical, chemical, mechanic and aesthetic terms. Empirical understanding of the most important properties of wood to structure purposes, the defects of structural timbers, the framing and the preliminary survey followed by the structural survey were some of the difficulties which can be overcame in practice.展开更多
It is necessary to clarify the influence of thermal history on the conversion of aluminate species in sodium aluminate solution in order to optimize Bayer alumina production. The interconversion of various solution sp...It is necessary to clarify the influence of thermal history on the conversion of aluminate species in sodium aluminate solution in order to optimize Bayer alumina production. The interconversion of various solution species in the systems was investigated by measuring the infrared spectra of sodium aluminate solution with different compositions after separate heat treatment, dilution and concentration. The results show that increasing temperature or prolonging holding time favors the transformation of Al2O(OH)2- to Al—OH vibration(condensed Al O4 tetrahedral aluminate ion) at about 880 cm-1 and Al(OH)-4. A12O(OH)2-66 and Al—OH tetrahedral dimer ions convert rapidly to Al(OH)-4 during the dilution process; however, the back transformation of Al(OH)-4 to the Al—OH tetrahedral dimer ions can occur in diluted sodium aluminate solution. As for the concentration process, the transformation of Al(OH)-4 to A12O(OH)2-6 and Al—OH tetrahedral dimer ions can take place, while it is relatively difficult to transform to A12O(OH)2-6.展开更多
Treeline ecotone dynamics of Abies spectabilis (D. Don) Mirb. in the Barun valley, Makalu Barun National Park, eastern Nepal Himalaya were studied by establishing seven plots (20 m x variable length) from the fore...Treeline ecotone dynamics of Abies spectabilis (D. Don) Mirb. in the Barun valley, Makalu Barun National Park, eastern Nepal Himalaya were studied by establishing seven plots (20 m x variable length) from the foresfline to the tree species limit: three plots on the south- and north-facing slopes each (S1-S3, N1-N3), and one plot on the east- facing slope (E) in the relatively undisturbed forests. A dendroecological method was used to study treeline advance rate and recruitment pattern. In all the plots, most trees established in the early 20th century, and establishment in the second half of the 20th century was confined to the foresfline area. Treeline position has not advanced substantially in the Barun valley, with 0nly 22 m average elevational shift in the last 13o years, and with average current shifting rate of 14 cm/yr. Moreover, no significant relationship was found between tree age and elevation on the south-, north-, and east-facing slopes. The number of seedlings and saplings in near the treeline area was negligible compared to that near the foresfline area. Therefore, A. spectabilis treeline response to the temperature change was slow, despite the increasing temperature trend in the region. Beside the temperature change, factors such as high inter-annual variability in temperature, dense shrub cover, and local topography also play an important role in treeline advance and controlling recruitment pattern above the treeline.展开更多
Understanding the nature of liquid structures and properties has always been a hot field in condensed matter physics and metallic materials science.The liquid is not homogeneous and the local structures inside change ...Understanding the nature of liquid structures and properties has always been a hot field in condensed matter physics and metallic materials science.The liquid is not homogeneous and the local structures inside change discontinuously with temperature,pressure,etc.The liquid will experience liquid−liquid structure transition under a certain condition.Liquid−liquid structure transition widely exists in many metals and alloys and plays an important role in the final microstructure and the properties of the solid alloys.This work provides a comprehensive review on this unique structure transition in the metallic liquid together with the recent progress of its impact on the following microstructure and properties after solidification.These effects are discussed by integrating them into different experimental results and theoretical considerations.The application of liquid−liquid structure transition as a strategy to tailor the properties of metals and alloys is proven to be practical and efficient.展开更多
This paper investigates the history of upgrade of industrial structure in human society from a combined perspective of economic and philosophical history encompassing primitive society,ancient society and recent and m...This paper investigates the history of upgrade of industrial structure in human society from a combined perspective of economic and philosophical history encompassing primitive society,ancient society and recent and modern society.As far as recent and modern society is concerned,this paper divides the upgrade into two basic aspects:the shifting dominant position of primary,secondary and tertiary industries,and that of laborintensive,capital-intensive and knowledge-intensive industries.Moreover,this paper has examined the history of upgrade of industrial structure in China since 1949 and identified that the upgrade of China's industrial structure demonstrates not only the characteristics of middle and late stages of industrialization but characteristics of modernization as well.According to the general pattern of upgrade of industrial structure in recent and modern society and China's reality,great efforts must be made to improve China's indigenous innovation capacity,expedite agriculture modernization,increase competitiveness and qualitative development of manufacturing sector,and vigorously promote service sector(especially producers services),environmental protection industry,culture industry and maritime industry.展开更多
The research of the Russian issue in academic level has a great importance. The Putin-term Russian economy is inadvance, and it reminds of the great economy of the old Soviet Union. For that reason, Putin was given th...The research of the Russian issue in academic level has a great importance. The Putin-term Russian economy is inadvance, and it reminds of the great economy of the old Soviet Union. For that reason, Putin was given the nicknameof the new Russian Tsar. Putin is well-liked by the Russian citizens; as a person he is liked by a vast majority of theRussian population. Putin is indepted his great personality both to the successes achived from the Chechen War andto the numerous successes he has achieved in the economic stabilization since he undertook the management of Rsia. It is true that today Russia has no enough political and economical power to maintain the bipolar world as Ria has an economy of smaller than the one-tenth of the US economy. Nonetheless, Russia is still the secondsuper power of the world as she has nuclear weapons and more than 20 satellites in the space. Russia, today, is aself-sufficient country in having the technology of launching her own satellites, and the very first inventors of therocket technology are Russians. Today, Turkey has a lot to learn from Russia. Putin has been able to attract foreigncapital. The removal of the bureaucratic obstacles affecting the foreigners can be an example to this. Today, Turkeychooses the way of selling of the lands to attract the foreign capital. I think the selling of the lands is not a sensiblepolicy to attract foreign capital, and if the Russian model is adopted more efficient results can be obtained.展开更多
The paper shows the approach toward the calculation of one of the bigger PFRP (Pultruded Fiber Reinforced Polymer) structure realized in high seismic zone, i.e., a covering structure of an historic church stroked an...The paper shows the approach toward the calculation of one of the bigger PFRP (Pultruded Fiber Reinforced Polymer) structure realized in high seismic zone, i.e., a covering structure of an historic church stroked and partially collapsed by earthquake in L'Aquila (Italy), the 4 April 2009. The goal regards the analysis and evaluation of seismic performance of that structure made by very light and elastic-brittle material, as FRP material, in a moment in which there is a loss of technical recommendation for specific calculation in seismic field, indeed actually some deepening already present in literature allows only static field. The covering structure is an all FRP spatial-reticular with elements made by pultrusion process, connection plates by bag molding process and steel bolts. The PFRP structure covers more than 1000 meters squares surface with 32 meters height and only 100 kN weight. Detail performance of first part of PFRP structure through mode vibrations and involved percentage mass deduced by numerical approach with discussion of employment's perspectives of PFRP material in seismic zones than traditional material are showed.展开更多
Mortars are among the first building materials used in constructions, even from prehistoric times (8th millennium BC). Their study reveals a great source of information regarding the evolution of their technological...Mortars are among the first building materials used in constructions, even from prehistoric times (8th millennium BC). Their study reveals a great source of information regarding the evolution of their technological characteristics and application techniques, the availability and exploitation of raw materials, as well the wider socio-economic aspects of each era. The aim of this paper is to comparatively evaluate the analysis results from approximately 1,000 structural mortar samples taken from various monuments and historic buildings of Greece, dated from the Hellenistic period, until the beginning of the 20th century. The analysis focused in the determination of their physico-mechanical and chemical properties, such as porosity, apparent specific gravity, mechanical strength, aggregates type and granulometry and chemical composition. Through the results' evaluation, significant remarks can be made upon the evolution of the raw materials used (binding system, aggregates, additives), as well as regarding the final properties of historic structural mortars. It is concluded that hydrated lime was the main binding agent used for a long-lasting period of 2.5 millenniums, while mixed type binding systems based on lime and natural pozzolan were systematically used for producing durable mortars, resistant to humidity. In any case, it seems that ancient masons were fully aware of the significant role of mortars in constructions and were capable of exploiting the available raw materials and application techniques to the maximum.展开更多
Societa Nazionale Officine di Savigliano was a company specialized in railway constructions, metallic bridges and mechanical and electrical constructions. Between the end of the 19th century and the beginning of the 2...Societa Nazionale Officine di Savigliano was a company specialized in railway constructions, metallic bridges and mechanical and electrical constructions. Between the end of the 19th century and the beginning of the 20th century, the company became well known in Europe especially for metallic constructions, having built the majority of metal bridges in the north of Italy such as the famous Paderno bridge (1887-1889), one of the biggest arch bridge for the period. In the 1930s, the company built some interesting examples of steel frame buildings, applying the electrical welding technique, acquired in industrial constructions, to civil buildings. The steel frame was quite rare in Italian buildings, especially in the matter of civil constructions and Savigliano made an effort in modernizing the Italian construction system, through research and innovation. The paper will discuss some examples of Savigliano's works dating back to 1930, and in particular, it will present a specific example never studied before: the hangar at the Elmas military airport, in Cagliari (Sardinia). The building is worth mentioning for the innovations experimented, as the new welding technique allowed a series of improvements in the construction process.展开更多
The Mirahor Ilyas Beg Mosque, built in 1496 in Korea, is one of a few Ottoman mosques still existing in Albania and the only Ottoman monument in the city. The mosque was built using cut stone and brick. It has a stron...The Mirahor Ilyas Beg Mosque, built in 1496 in Korea, is one of a few Ottoman mosques still existing in Albania and the only Ottoman monument in the city. The mosque was built using cut stone and brick. It has a strong image a cubic mass rising over a square plan. Inside there are found pictures of the mosque in the past and different famous mosques. During its existence, it was damaged from many earthquakes occurring at this area. Due to amortization, the mosque's structural properties were weakened and architectural values were dimmed. Proper strengthening methods need to be applied, not only to improve structural conditions, but also to preserve architectural features of the mosque. In this paper assessment of existing conditions of the structure is carried out Based on the obtained results, solutions for the structural problems are investigated. As for restoration, the repair methods to be applied were examined taking into consideration at what extent the historical values of the building will be preserved. The proposed strengthening methods are the ones which would affect the least the mosque's historical values.展开更多
The case in analysis is Santa Maria di Collemaggio, the church symbol of the town of L'Aquila and the most important example of Romanesque style in Abruzzi, tragically damaged by the earthquake in 2009. The following...The case in analysis is Santa Maria di Collemaggio, the church symbol of the town of L'Aquila and the most important example of Romanesque style in Abruzzi, tragically damaged by the earthquake in 2009. The following paper starts with an accurate analysis of the Basilica, whose historical, stylistical cultural characteristics make it an unicum in the whole urban environment. The authors tried to identify in which way these values have been compromised or altered after the earthquake through several analysis (surveys, historical researches etc.) aiming at the recognition of collapses, the cracks profile, the structural transformations caused by the provisional measures: the goal is to provide a kind of Basilica "cognitive manual" that will be useful for the future interventions. This first analysis allowed to understand many aspects: on the one hand, the constructive phases and which damages were caused by past careless interventions of restoration, drawing attention to the vulnerability elements of the Basilica; on the other hand, the innovative technologies and materials of the post-seismic provisional measures and their exact location.展开更多
The content of China's economic transformation is not single, and this article argues that it includes three parts. The first is the reform of economic system, the second is the change in the pattern of economic grow...The content of China's economic transformation is not single, and this article argues that it includes three parts. The first is the reform of economic system, the second is the change in the pattern of economic growth, and the third is the adjustment of economic structure. Government is the leading force of China's economic transformation, and repeated reform of government institutions has brought about some changes to government functions. But problems are obvious that lag changes of government functions have become an obstacle in China's economic transformation. This article describes the historical evolution and the reality of China's economic transformation, and analyzes the main reasons of lag changes in government functions, and reveals that the transformation of government functions is the key for successful transformation of China's economy.展开更多
文摘Iranian traditional architecture can be identified in many of its old famous buildings in the country. The principles and specifications in these buildings show the intelligence of implemented techniques that makes them to remain stable. Thus, it is important to explore the traditional structures and architectural technologies in order to understand the reasons for this stability toward the new methods in modem architecture. Many of historical buildings in Iran have remained standing after many years and they show the deep wisdom of their architects. The purpose of this article is studying the various aspects of traditional structure and integration between this well-oriented structure and architecture. For reaching this goal, we refer to Tekye-Amir-Chakhmagh in Yazd as our case study, which is one of the most important and noticeable examples of Iranian traditional architecture. By introducing Amir-Chakhmagh Complex, we analyzed the specifications and fundamental elements that played an important role in stability and sustainability of Tekye-Amir-Chakhmagh and thereafter, we assessed the technologies that were used intelligently and intricately in this historical building. In this research, information is collected with field study and library resources. Finally, qualities and characteristics of the structure are studied by drawings and structural analysis and as conclusion, the suggestions and guidelines are presented.
文摘Language, literature, customs and traditions, music and art are cultural items that were transmitted from generation to generation throughout history. In this context, literature is an important source of music culture that takes inspiration from the customs and traditions of a society. Prosodic meter is echoed in form, usul and general structure in works composed from the divan literature and almost lives in the work. In the same way, when examples of folk literature composed by composers and performed by poets and a^lks are examined, it is observed that there are parallels between literary features and form, structure and rhythmic features. The aim of this paper is to reveal the integral link between Melody-Usul and Meter in Ottoman Turkish Music
文摘The concept of "real man" is the historical origin and the logical starting point in The Marx's Materialist Conception of History, and is also our basic starting point in the social science research. Although our country's social security system has made great development and progress, but it still does not adapts the level of economy development, especially compared with the requirements of the people. Based on the principle of Marx's "real man" theory and combine the "real man" with the "people oriented", this article discussed the basic framework of the present social security system and its shortcomings in China. Then I try to put forward suggestions from breaking the urban-rural dual structure, gradually establishing urban and rural areas as a whole one of social security system, actively expanding the social security fund financing channels, establishing a nationwide unified social security of personal accounts, strive to establish a "people oriented" social security system.
文摘Near 50 years history of the development of radioisotope neutron sources in China is briefly reviewed.The structure design,preparing technology and production status of routine neutron sources including 210Po-Be sources,210Po mock fission sources,241Am-Be sources,238Pu-Be sources,252Cf spontaneous fission sources and other special-shape neutron sources are summarized.In addition,the prospects of development on radioisotope neutron source in China are predicted from the needs of nuclear power construction,oil well-logging,neutron moisture gauge and neutron brachytherapy.
文摘With the continuous development of political, economic,social, empty nesters and more problems, it is not a simple personal issues, has become urgent to break the social proposition.This paper intr~,duces the concepts at the same time,Further analysis of the current situation empty-nesters of the problem and sort out the history of urban-rural dual structure,Finally, find information put forward some countermeasures and suggestions.
文摘The objective of this paper is to study the influence of repeated variable action on long-term behavior of concrete structural elements using quasi-permanent combination of actions, for the assessment of long-term effects (e.g., effects due to creep and shrinkage in concrete structures), as it is proposed in Eurocodes. Extensive experimental program and analytical research using model B3 and AAEM (age adjusted effective modulus) method was performed in order to define quasi-permanent factor ψ2, for two specific loading histories. These loading histories were consist of long-term permanent action "G" and repeated variable action "Q". The variable load was applied in cycles of loading/unloading for 24 h and 48 h in period of 400 days appropriately for one series of concrete elements. 24 reinforced concrete beams, dimensions 150 mm × 280 mm × 3,000 mm, were tested. Twelve beams were made of concrete class C30/37 and 12 of concrete class C60/75.
文摘It is a very hard job for historians to keep themselves neutrals in from of the events they find during their studies. It is also difficult to notice the correlations among the different times of the history without falling in anachronistic mistakes. In fact, it is well-known that a historian must be wise and rational when he finds those correlations, because every society has its own characteristics, structures, and mentality. This brief essay focuses on the social structures in a north eastern italic region, which is called Friuli, between the 12th and 16th centuries. In the above mentioned centuries, it is possible to notice an evolution from a feudal ecclesiastical principality, ruled by prince-patriarchs, ecclesiastical institutions and nobility, to a more fluid and dynamic constitution formed by new classes which rose up in times of urban and economic development. But this development struggles to delete the old system, which persisted until the end of 18th century with the arrival of Napoleon. The transition from the Patriarch's power to Venice's dominion seems to have created two main consequences: by one hand a more bureaucratic and modem structure of the State, by the other hand a consolidation of the old connections between patrons and clients, consequence of the "modem" feudal system that consolidated its roots in the Late Middle Ages centuries.
文摘This paperprovides a historical overview intending to clarify the methods of interpretation of timber-framed buildings by different authors of construction treatises, and structural intentions of the carpentry designers and master builders, throughout the centuries, until the period when it became scientific structural theory. It describes the "box-frame" construction that appeared in Lisbon, after the earthquake of 1755, characterized by its good seismic resistance. This knowledge is important to determine a strategy of an efficient restoration practice in historical constructions which require an intervention subordinated to its raised patrimonial and artistic value, minimum, which respects the authenticity of its structural and construction conception and which is reversible and compatible, in physical, chemical, mechanic and aesthetic terms. Empirical understanding of the most important properties of wood to structure purposes, the defects of structural timbers, the framing and the preliminary survey followed by the structural survey were some of the difficulties which can be overcame in practice.
基金Project(51274243)supported by the National Natural Science Foundation of China
文摘It is necessary to clarify the influence of thermal history on the conversion of aluminate species in sodium aluminate solution in order to optimize Bayer alumina production. The interconversion of various solution species in the systems was investigated by measuring the infrared spectra of sodium aluminate solution with different compositions after separate heat treatment, dilution and concentration. The results show that increasing temperature or prolonging holding time favors the transformation of Al2O(OH)2- to Al—OH vibration(condensed Al O4 tetrahedral aluminate ion) at about 880 cm-1 and Al(OH)-4. A12O(OH)2-66 and Al—OH tetrahedral dimer ions convert rapidly to Al(OH)-4 during the dilution process; however, the back transformation of Al(OH)-4 to the Al—OH tetrahedral dimer ions can occur in diluted sodium aluminate solution. As for the concentration process, the transformation of Al(OH)-4 to A12O(OH)2-6 and Al—OH tetrahedral dimer ions can take place, while it is relatively difficult to transform to A12O(OH)2-6.
文摘Treeline ecotone dynamics of Abies spectabilis (D. Don) Mirb. in the Barun valley, Makalu Barun National Park, eastern Nepal Himalaya were studied by establishing seven plots (20 m x variable length) from the foresfline to the tree species limit: three plots on the south- and north-facing slopes each (S1-S3, N1-N3), and one plot on the east- facing slope (E) in the relatively undisturbed forests. A dendroecological method was used to study treeline advance rate and recruitment pattern. In all the plots, most trees established in the early 20th century, and establishment in the second half of the 20th century was confined to the foresfline area. Treeline position has not advanced substantially in the Barun valley, with 0nly 22 m average elevational shift in the last 13o years, and with average current shifting rate of 14 cm/yr. Moreover, no significant relationship was found between tree age and elevation on the south-, north-, and east-facing slopes. The number of seedlings and saplings in near the treeline area was negligible compared to that near the foresfline area. Therefore, A. spectabilis treeline response to the temperature change was slow, despite the increasing temperature trend in the region. Beside the temperature change, factors such as high inter-annual variability in temperature, dense shrub cover, and local topography also play an important role in treeline advance and controlling recruitment pattern above the treeline.
基金Project(51690164)supported by the National Natural Science Foundation of ChinaProject(2019-TS-04)supported by the State Key Laboratory of Solidification Processing,China。
文摘Understanding the nature of liquid structures and properties has always been a hot field in condensed matter physics and metallic materials science.The liquid is not homogeneous and the local structures inside change discontinuously with temperature,pressure,etc.The liquid will experience liquid−liquid structure transition under a certain condition.Liquid−liquid structure transition widely exists in many metals and alloys and plays an important role in the final microstructure and the properties of the solid alloys.This work provides a comprehensive review on this unique structure transition in the metallic liquid together with the recent progress of its impact on the following microstructure and properties after solidification.These effects are discussed by integrating them into different experimental results and theoretical considerations.The application of liquid−liquid structure transition as a strategy to tailor the properties of metals and alloys is proven to be practical and efficient.
文摘This paper investigates the history of upgrade of industrial structure in human society from a combined perspective of economic and philosophical history encompassing primitive society,ancient society and recent and modern society.As far as recent and modern society is concerned,this paper divides the upgrade into two basic aspects:the shifting dominant position of primary,secondary and tertiary industries,and that of laborintensive,capital-intensive and knowledge-intensive industries.Moreover,this paper has examined the history of upgrade of industrial structure in China since 1949 and identified that the upgrade of China's industrial structure demonstrates not only the characteristics of middle and late stages of industrialization but characteristics of modernization as well.According to the general pattern of upgrade of industrial structure in recent and modern society and China's reality,great efforts must be made to improve China's indigenous innovation capacity,expedite agriculture modernization,increase competitiveness and qualitative development of manufacturing sector,and vigorously promote service sector(especially producers services),environmental protection industry,culture industry and maritime industry.
文摘The research of the Russian issue in academic level has a great importance. The Putin-term Russian economy is inadvance, and it reminds of the great economy of the old Soviet Union. For that reason, Putin was given the nicknameof the new Russian Tsar. Putin is well-liked by the Russian citizens; as a person he is liked by a vast majority of theRussian population. Putin is indepted his great personality both to the successes achived from the Chechen War andto the numerous successes he has achieved in the economic stabilization since he undertook the management of Rsia. It is true that today Russia has no enough political and economical power to maintain the bipolar world as Ria has an economy of smaller than the one-tenth of the US economy. Nonetheless, Russia is still the secondsuper power of the world as she has nuclear weapons and more than 20 satellites in the space. Russia, today, is aself-sufficient country in having the technology of launching her own satellites, and the very first inventors of therocket technology are Russians. Today, Turkey has a lot to learn from Russia. Putin has been able to attract foreigncapital. The removal of the bureaucratic obstacles affecting the foreigners can be an example to this. Today, Turkeychooses the way of selling of the lands to attract the foreign capital. I think the selling of the lands is not a sensiblepolicy to attract foreign capital, and if the Russian model is adopted more efficient results can be obtained.
文摘The paper shows the approach toward the calculation of one of the bigger PFRP (Pultruded Fiber Reinforced Polymer) structure realized in high seismic zone, i.e., a covering structure of an historic church stroked and partially collapsed by earthquake in L'Aquila (Italy), the 4 April 2009. The goal regards the analysis and evaluation of seismic performance of that structure made by very light and elastic-brittle material, as FRP material, in a moment in which there is a loss of technical recommendation for specific calculation in seismic field, indeed actually some deepening already present in literature allows only static field. The covering structure is an all FRP spatial-reticular with elements made by pultrusion process, connection plates by bag molding process and steel bolts. The PFRP structure covers more than 1000 meters squares surface with 32 meters height and only 100 kN weight. Detail performance of first part of PFRP structure through mode vibrations and involved percentage mass deduced by numerical approach with discussion of employment's perspectives of PFRP material in seismic zones than traditional material are showed.
文摘Mortars are among the first building materials used in constructions, even from prehistoric times (8th millennium BC). Their study reveals a great source of information regarding the evolution of their technological characteristics and application techniques, the availability and exploitation of raw materials, as well the wider socio-economic aspects of each era. The aim of this paper is to comparatively evaluate the analysis results from approximately 1,000 structural mortar samples taken from various monuments and historic buildings of Greece, dated from the Hellenistic period, until the beginning of the 20th century. The analysis focused in the determination of their physico-mechanical and chemical properties, such as porosity, apparent specific gravity, mechanical strength, aggregates type and granulometry and chemical composition. Through the results' evaluation, significant remarks can be made upon the evolution of the raw materials used (binding system, aggregates, additives), as well as regarding the final properties of historic structural mortars. It is concluded that hydrated lime was the main binding agent used for a long-lasting period of 2.5 millenniums, while mixed type binding systems based on lime and natural pozzolan were systematically used for producing durable mortars, resistant to humidity. In any case, it seems that ancient masons were fully aware of the significant role of mortars in constructions and were capable of exploiting the available raw materials and application techniques to the maximum.
文摘Societa Nazionale Officine di Savigliano was a company specialized in railway constructions, metallic bridges and mechanical and electrical constructions. Between the end of the 19th century and the beginning of the 20th century, the company became well known in Europe especially for metallic constructions, having built the majority of metal bridges in the north of Italy such as the famous Paderno bridge (1887-1889), one of the biggest arch bridge for the period. In the 1930s, the company built some interesting examples of steel frame buildings, applying the electrical welding technique, acquired in industrial constructions, to civil buildings. The steel frame was quite rare in Italian buildings, especially in the matter of civil constructions and Savigliano made an effort in modernizing the Italian construction system, through research and innovation. The paper will discuss some examples of Savigliano's works dating back to 1930, and in particular, it will present a specific example never studied before: the hangar at the Elmas military airport, in Cagliari (Sardinia). The building is worth mentioning for the innovations experimented, as the new welding technique allowed a series of improvements in the construction process.
文摘The Mirahor Ilyas Beg Mosque, built in 1496 in Korea, is one of a few Ottoman mosques still existing in Albania and the only Ottoman monument in the city. The mosque was built using cut stone and brick. It has a strong image a cubic mass rising over a square plan. Inside there are found pictures of the mosque in the past and different famous mosques. During its existence, it was damaged from many earthquakes occurring at this area. Due to amortization, the mosque's structural properties were weakened and architectural values were dimmed. Proper strengthening methods need to be applied, not only to improve structural conditions, but also to preserve architectural features of the mosque. In this paper assessment of existing conditions of the structure is carried out Based on the obtained results, solutions for the structural problems are investigated. As for restoration, the repair methods to be applied were examined taking into consideration at what extent the historical values of the building will be preserved. The proposed strengthening methods are the ones which would affect the least the mosque's historical values.
文摘The case in analysis is Santa Maria di Collemaggio, the church symbol of the town of L'Aquila and the most important example of Romanesque style in Abruzzi, tragically damaged by the earthquake in 2009. The following paper starts with an accurate analysis of the Basilica, whose historical, stylistical cultural characteristics make it an unicum in the whole urban environment. The authors tried to identify in which way these values have been compromised or altered after the earthquake through several analysis (surveys, historical researches etc.) aiming at the recognition of collapses, the cracks profile, the structural transformations caused by the provisional measures: the goal is to provide a kind of Basilica "cognitive manual" that will be useful for the future interventions. This first analysis allowed to understand many aspects: on the one hand, the constructive phases and which damages were caused by past careless interventions of restoration, drawing attention to the vulnerability elements of the Basilica; on the other hand, the innovative technologies and materials of the post-seismic provisional measures and their exact location.
文摘The content of China's economic transformation is not single, and this article argues that it includes three parts. The first is the reform of economic system, the second is the change in the pattern of economic growth, and the third is the adjustment of economic structure. Government is the leading force of China's economic transformation, and repeated reform of government institutions has brought about some changes to government functions. But problems are obvious that lag changes of government functions have become an obstacle in China's economic transformation. This article describes the historical evolution and the reality of China's economic transformation, and analyzes the main reasons of lag changes in government functions, and reveals that the transformation of government functions is the key for successful transformation of China's economy.