Estimation of creep and shrinkage in concrete bridges is still approximate and uncertain. Over the years, Polish Codes for Concrete Structures partially adapted the CEB （Euro-International Concrete Committee）-FIP （...Estimation of creep and shrinkage in concrete bridges is still approximate and uncertain. Over the years, Polish Codes for Concrete Structures partially adapted the CEB （Euro-International Concrete Committee）-FIP （International Federation for Prestressing） models used to predict creep and shrinkage of concrete. In the currently used Polish concrete bridge code, modified CEB-FIP 1970 recommendations are used. At the time the standard was implemented, it introduced simple methods for the evaluation of final creep coefficients and shrinkage strains. It was sufficient for simple bridge structures and concrete technology used at that times. As modern bridge structures have become increasingly complex with variable construction techniques and developing concrete technology, the implementation of Eurocode 2 is necessary as it gives more practical and accurate methods for the prediction of creep and shrinkage effects. A comparative analysis of the time-dependent deformation of concrete included in Eurocode 2 and in Polish Bridge Codes is pointing out that there is a necessity for more adequate criteria for the rapidly growing concrete bridge stock in Poland.展开更多
At present, all aspects of China have entered the era of a rapid development, while the development speed of digital electronic technology is especially outstanding. This is a new way for China＇ s new personnel train...At present, all aspects of China have entered the era of a rapid development, while the development speed of digital electronic technology is especially outstanding. This is a new way for China＇ s new personnel training, and also proposes higher requirements on this type of personnel training institutions. In view of the demands of society and different majors on personnel, an enhancement to the standardized management of electronic laboratory operations becomes one of the important tasks for personnel training institutions. In this paper, how to practice the standardization management in an all-round way is discussed centered at college and university students＇ electronic laboratory.展开更多
Dutch building regulation is under construction. After the report of the commission ＂Fundamentele Verkenning Bouw＂ in 2008, several studies have been done on the principals that the commission outlined in its report...Dutch building regulation is under construction. After the report of the commission ＂Fundamentele Verkenning Bouw＂ in 2008, several studies have been done on the principals that the commission outlined in its report. Local authorities and parties in construction were invited to start experiments with a more privatized system of building control. But this faced a lack of participation, partly due to the impact of the crisis. The minister responsible for housing and construction invited in 2011 a ＂Bouwteam＂ to develop an agenda for action for construction. In 2012, 17 action teams started to focus, speed up and simplify the planning and development of construction. Recently, the two teams related to building regulation presented their plans. The first was a roadmap towards private building control, the second, a proposal for an independent body to answer questions on constructions plans that do intrinsically but not legally meet the standards of building regulation. There is considerable controversy regarding the way that this implementation team is paving its path towards private building control. While the minister for housing conformed himself to a subsidized private implementing team, the Dutch Parliament has expressed its own priorities for regulation： insured guarantee to protect users and owners, a role for local authorities regarding safety and acceptance of buildings and simplification of building regulation and control for simple construction works. The parliament held a round-table conference to get informed about private building control. Recently, a proposal by the minister for housing was discussed. Further debate will be needed to decide about the next steps in innovation building regulation, which will take place in the upcoming months. ERB/RIGO （Foundation Expert Centre Regulations in Building/Research Institute for Real Estate） have developed own proposals for the public-private relation regarding development and construction of buildings. They expect that their proposals might be of help. The proposals are laid down in several publications and partly realized in experimental development of ＂to be approved＂ technical solutions. This paper reflects on the differences between their proposals and these of the roadmap, on the possible outcome of the ongoing debate and its implications, legal and technical, on building regulation and on legal and contractual liability. This paper tries to give an inside view on the development of regulation and the pros and cons of the proposals, starting from a theoretical outline of building regulation.展开更多
We derive the basic canonical brackets amongst the creation and annihilation operators for a two(1 + 1)-dimensional(2D) gauge field theoretic model of an interacting Hodge theory where a U(1) gauge field(Aμ) is coupl...We derive the basic canonical brackets amongst the creation and annihilation operators for a two(1 + 1)-dimensional(2D) gauge field theoretic model of an interacting Hodge theory where a U(1) gauge field(Aμ) is coupled with the fermionic Dirac fields(ψ andˉψ). In this derivation, we exploit the spin-statistics theorem, normal ordering and the strength of the underlying six infinitesimal continuous symmetries(and the concept of their generators) that are present in the theory. We do not use the definition of the canonical conjugate momenta(corresponding to the basic fields of the theory) anywhere in our whole discussion. Thus, we conjecture that our present approach provides an alternative to the canonical method of quantization for a class of gauge field theories that are physical examples of Hodge theory where the continuous symmetries(and corresponding generators) provide the physical realizations of the de Rham cohomological operators of differential geometry at the algebraic level.展开更多
文摘Estimation of creep and shrinkage in concrete bridges is still approximate and uncertain. Over the years, Polish Codes for Concrete Structures partially adapted the CEB （Euro-International Concrete Committee）-FIP （International Federation for Prestressing） models used to predict creep and shrinkage of concrete. In the currently used Polish concrete bridge code, modified CEB-FIP 1970 recommendations are used. At the time the standard was implemented, it introduced simple methods for the evaluation of final creep coefficients and shrinkage strains. It was sufficient for simple bridge structures and concrete technology used at that times. As modern bridge structures have become increasingly complex with variable construction techniques and developing concrete technology, the implementation of Eurocode 2 is necessary as it gives more practical and accurate methods for the prediction of creep and shrinkage effects. A comparative analysis of the time-dependent deformation of concrete included in Eurocode 2 and in Polish Bridge Codes is pointing out that there is a necessity for more adequate criteria for the rapidly growing concrete bridge stock in Poland.
文摘At present, all aspects of China have entered the era of a rapid development, while the development speed of digital electronic technology is especially outstanding. This is a new way for China＇ s new personnel training, and also proposes higher requirements on this type of personnel training institutions. In view of the demands of society and different majors on personnel, an enhancement to the standardized management of electronic laboratory operations becomes one of the important tasks for personnel training institutions. In this paper, how to practice the standardization management in an all-round way is discussed centered at college and university students＇ electronic laboratory.
文摘Dutch building regulation is under construction. After the report of the commission ＂Fundamentele Verkenning Bouw＂ in 2008, several studies have been done on the principals that the commission outlined in its report. Local authorities and parties in construction were invited to start experiments with a more privatized system of building control. But this faced a lack of participation, partly due to the impact of the crisis. The minister responsible for housing and construction invited in 2011 a ＂Bouwteam＂ to develop an agenda for action for construction. In 2012, 17 action teams started to focus, speed up and simplify the planning and development of construction. Recently, the two teams related to building regulation presented their plans. The first was a roadmap towards private building control, the second, a proposal for an independent body to answer questions on constructions plans that do intrinsically but not legally meet the standards of building regulation. There is considerable controversy regarding the way that this implementation team is paving its path towards private building control. While the minister for housing conformed himself to a subsidized private implementing team, the Dutch Parliament has expressed its own priorities for regulation： insured guarantee to protect users and owners, a role for local authorities regarding safety and acceptance of buildings and simplification of building regulation and control for simple construction works. The parliament held a round-table conference to get informed about private building control. Recently, a proposal by the minister for housing was discussed. Further debate will be needed to decide about the next steps in innovation building regulation, which will take place in the upcoming months. ERB/RIGO （Foundation Expert Centre Regulations in Building/Research Institute for Real Estate） have developed own proposals for the public-private relation regarding development and construction of buildings. They expect that their proposals might be of help. The proposals are laid down in several publications and partly realized in experimental development of ＂to be approved＂ technical solutions. This paper reflects on the differences between their proposals and these of the roadmap, on the possible outcome of the ongoing debate and its implications, legal and technical, on building regulation and on legal and contractual liability. This paper tries to give an inside view on the development of regulation and the pros and cons of the proposals, starting from a theoretical outline of building regulation.
基金the financial support from CSIR and UGC, New Delhi, Government of India, respectively
文摘We derive the basic canonical brackets amongst the creation and annihilation operators for a two(1 + 1)-dimensional(2D) gauge field theoretic model of an interacting Hodge theory where a U(1) gauge field(Aμ) is coupled with the fermionic Dirac fields(ψ andˉψ). In this derivation, we exploit the spin-statistics theorem, normal ordering and the strength of the underlying six infinitesimal continuous symmetries(and the concept of their generators) that are present in the theory. We do not use the definition of the canonical conjugate momenta(corresponding to the basic fields of the theory) anywhere in our whole discussion. Thus, we conjecture that our present approach provides an alternative to the canonical method of quantization for a class of gauge field theories that are physical examples of Hodge theory where the continuous symmetries(and corresponding generators) provide the physical realizations of the de Rham cohomological operators of differential geometry at the algebraic level.
