Urban development should rely on the form of architecture,and incorporating urban planning concepts into architectural design can better assist urban construction.Taking the design of Incheon Geomdan Cultural Complex ...Urban development should rely on the form of architecture,and incorporating urban planning concepts into architectural design can better assist urban construction.Taking the design of Incheon Geomdan Cultural Complex in South Korea as an example,this paper analyzes how to reflect urban planning elements in architectural design,and studies the role and value of cultural complex architecture in urban development from multiple perspectives such as culture,ecological environment,and public space.It hopes to gain more research and design ideas to promote the development of cultural industries in the region,leverage the advantages of regional cultural formats,and create new cultural settlements in cities.展开更多
Railways within the city carry the historical memory of urban development and are important industrial heritage resources.However,with urban development and changes in transportation functions,railways lose their orig...Railways within the city carry the historical memory of urban development and are important industrial heritage resources.However,with urban development and changes in transportation functions,railways lose their original application value and are gradually left unused or even abandoned,affecting the vitality of the region.Taking the space around Xihuangcun Railway Station as the research object,the public activity space on both sides of the railway is reshaped through five strategies:function revitalization,traffic revitalization,heritage revitalization,spatial revitalization,and landscape revitalization,and the grey area of the city is transformed into a vibrant development zone of the city.展开更多
The application of environment-behavior studies plays an important role in studying the renewal of shantytowns.One of the most humane ways of renewal is designing and constructing the necessary urban spatial environme...The application of environment-behavior studies plays an important role in studying the renewal of shantytowns.One of the most humane ways of renewal is designing and constructing the necessary urban spatial environment from the perspective of human daily behavior.Most of the shantytown renovation projects currently carried out in China are mainly focused on demolition and reconstruction,which not only incurs high costs but also damages the original social structure and economic model.During the process of shantytown renewal,it should improve the urban landscape,living environment,and life quality of residents,and ensure the daily life of shantytown residents without increasing their economic burden,and preserve the traces of urban development.In order to achieve this goal,it should explore the renewal strategies of shantytowns from the perspective of environment-behavior studies through behavior maps,on-site research,and literature review.Updating and design from a human perspective often achieve faster and better development;the renewal of shantytowns should be a bottom-up approach and start from a grassroots perspective,completing the renovation design through the composition of the population and behavioral patterns.展开更多
China’s move to promote a new round of large-scale equipment renewal is set to create an enormous green market.CHINA has placed much emphasis on encouraging large-scale equipment renewal and trade-ins of old consumer...China’s move to promote a new round of large-scale equipment renewal is set to create an enormous green market.CHINA has placed much emphasis on encouraging large-scale equipment renewal and trade-ins of old consumer goods over the past year,with the topic being highlighted both at the Central Economic Conference held at the end of 2023 and in the government work report of 2024.展开更多
Against the backdrop of incremental planning moving towards stock planning, strengtheningurban public space design to promote high-quality urban development has become a focus of attentionfor domestic scholars. Street...Against the backdrop of incremental planning moving towards stock planning, strengtheningurban public space design to promote high-quality urban development has become a focus of attentionfor domestic scholars. Street is a linear element of urban public space, and it is of great significance forimproving the quality of urban public space by studying the micro renewal design strategy of street space.Based on the interpretation of two urban renewal cases, Wangjing Street in Beijing and Mengzhuiwan inChengdu, taking Baihuazhou area in Nanchang City as an example, this paper analyzes the main problemsin the current situation of street space in Baihuazhou area from three aspects: space use, traffic organization,and waterfront space creation, and explores the micro renewal design strategy of the street space.展开更多
The residential area of Wuchang Vehicle Factory is taken as a case to explore the protection and renewal strategies of industrial heritage residential areas.By analyzing the current situation of the residential area,i...The residential area of Wuchang Vehicle Factory is taken as a case to explore the protection and renewal strategies of industrial heritage residential areas.By analyzing the current situation of the residential area,issues such as functional decline,memory loss,and weakened community vitality are revealed.Three design concepts are proposed:building renovation,historical space renovation,and the introduction of cultural and creative industries,aiming to improve the living environment,showcase historical value,cultivate cultural and creative industries,promote economic transformation,and community vitality.This paper could provide reference for the protection and renewal of similar industrial heritage residential areas,and new ideas for the research and utilization of industrial heritage.By comprehensively considering heritage protection,cultural inheritance,and community development,systematic suggestions are proposed.展开更多
Concept of urban renewal was elaborated,which for the protection of historic and cultural heritage not only provides a favorable opportunity of integrating neighboring environment and improving protection conditions,b...Concept of urban renewal was elaborated,which for the protection of historic and cultural heritage not only provides a favorable opportunity of integrating neighboring environment and improving protection conditions,but also imposes threats such as destroying its historic images and patterns,degrading of survival environment.To properly protect historic and cultural heritage in the unceasing urban renewal,and make it a significant resource and feature of the city but not a barrier of urban development,empirical analysis and theoretical research were adopted to analyze and study current conditions and problems of the protection of historic and cultural heritage in Xi'an City from the dimension of urban renewal concept and present urban renewal of Xi'an.Moreover,through summarizing successful experience of other regions,specific strategies were given to protect historic and cultural heritage of Xi'an City in its urban renewal more scientifically and reasonably.展开更多
Hollow fiber renewal liquid membrane(HFRLM) method was proposed based on the surface renewal theory for removal of aniline from waste water. The system of aniline + D2 EHPA in kerosene + HCl was used. Aqueous layer di...Hollow fiber renewal liquid membrane(HFRLM) method was proposed based on the surface renewal theory for removal of aniline from waste water. The system of aniline + D2 EHPA in kerosene + HCl was used. Aqueous layer diffusion in the feed phase is the rate-control step, and the influence of lumen side flow rate on the mass transfer is more significant than that on the shell side. The resistance of overall mass transfer is greatly reduced because of the mass transfer intensification in the renewal of liquid membrane on the lumen side. The driving force of mass transfer can be considered as a function of distribution equilibrium, and the overall mass transfer coefficient increases with the increase of p H in the feed solution, HCl concentration and D2 EHPA concentration, and decreases with the increase of initial aniline concentration. A mass transfer model is developed for HFRLM based on the surface renewal theory. The calculated results agree well with experimental results. The HFRLM process is a promising method for aniline wastewater treatment.展开更多
Based on the Danckwerts surface renewal model, a simple explicit expression of the enhancement factor in ozone absorption with a first order ozone self-decomposition and parallel second order ozonation reactions has b...Based on the Danckwerts surface renewal model, a simple explicit expression of the enhancement factor in ozone absorption with a first order ozone self-decomposition and parallel second order ozonation reactions has been derived. The results are compared with our previous work based on the film theory. The 2,4-dichlorophenol destruction rate by ozonation is predicted using the enhancement factor model in this paper.展开更多
We consider a random walk on Z in random environment with possible jumps {-L,…, -1, 1}, in the case that the environment {ωi : i ∈ Z} are i.i.d.. We establish the renewal theorem for the Markov chain of "the envi...We consider a random walk on Z in random environment with possible jumps {-L,…, -1, 1}, in the case that the environment {ωi : i ∈ Z} are i.i.d.. We establish the renewal theorem for the Markov chain of "the environment viewed from the particle" in both annealed probability and quenched probability, which generalize partially the results of Kesten (1977) and Lalley (1986) for the nearest random walk in random environment on Z, respectively. Our method is based on (L, 1)-RWRE formulated in Hong and Wang the intrinsic branching structure within the (2013).展开更多
The analytical renewal function(RF) is not tractable of the exponential Weibull(EW) distribution. In the proposed model, the n-fold convolution of the EW cumulative distribution function(CDF) is approximated by a n-fo...The analytical renewal function(RF) is not tractable of the exponential Weibull(EW) distribution. In the proposed model, the n-fold convolution of the EW cumulative distribution function(CDF) is approximated by a n-fold convolutions of Gamma and normal CDFs. We obtain the EW RF by a series approximation model. The method is very simple in the computation. When the parameters are unknown, we present the asymptotic confidence interval of the RF. The validity of the asymptotic confidence interval is checked via some numerical experiments.展开更多
The novel synergistic mixture of TBP and Cyanex-272 is used as the extractant in the hollow fiber renewal liquid membrane(HFRLM) technique for Zr/Hf separation.The effects of the chemical and operational parameters su...The novel synergistic mixture of TBP and Cyanex-272 is used as the extractant in the hollow fiber renewal liquid membrane(HFRLM) technique for Zr/Hf separation.The effects of the chemical and operational parameters such as HNO3 concentration in the donor phase,NH4 F concentration in the acceptor phase,Cyanex-272 and TBP concentration in the liquid membrane phase,the lumen and shell side flow rates,and aqueous/organic volume ratio on the mass transfer and separation performance of HFRLM method were investigated.The obtained results reveal the intensification potential of proposed HFRLM technique for selective extraction of Zr over Hf with separation factor higher than 100.The HFRLM method provides two times higher mass transfer flux in comparison with hollow fiber supported liquid membrane(HFSLM).Also,the HFRLM method shows satisfactory stability for 700 min of continuous operation.The Zr ion transport through the LM phase follows the coupled co-transport mechanism and the diffusion in the renewal layer is recognized as the rate-controlling step in the HFRLM process.Moreover,the Zr mass transfer coefficient and molar flux in the HFRLM method are calculated in the range of 1×10^-8 to 8.4×10^-7 m·s^-1 and 4.9×10^-6 to 20.1×10^-6 mol·m^-2·s^-1,respectively.展开更多
We previously showed that Wnt3a could stimulate human embryonic stem (hES) cell proliferation and affect cell fate determination. In the absence of feeder cell--derived factors, hES cells cultured under a feeder-fre...We previously showed that Wnt3a could stimulate human embryonic stem (hES) cell proliferation and affect cell fate determination. In the absence of feeder cell--derived factors, hES cells cultured under a feeder-free condition survived and proliferated poorly. Adding recombinant Wnt3a in the absence of feeder cell derived-factors stimulated hES cell proliferation but also differentiation. In the present study, we further extended our analysis to other Wnt ligands such as Wntl and Wnt5a. While Wntl displayed a similar effect on hES cells as Wnt3a, Wnt5a had little effect in this system. Wnt3a and Wntl enhanced proliferation of undifferentiated hES cells when feeder-derived self-renewal factors and bFGF are also present. To explore the possibility to promote the proliferation of undifferentiated hES cells by activating the Wnt signaling, we overexpressed Wnt3a or Wntl gene in immortalized human adult fibroblast (HAFi) cells that are superior in supporting long-term growth of undifferentiated hES cells than primary mouse embryonic fibroblasts. HAFi cells with or without a Wnt tmnsgene can be propagated indefinitely. Over-expression of the Wnt3a gene significantly enhanced the ability of HAFi feeder cells to support the undifferentiated growth of 3 different hES cell lines we tested. Co-expression of three commonly-used drug selection genes in Wnt3a-overpressing HAFi cells further enabled us to select rare hES clones after stable transfection or transduction. These immortalized engineered feeder cells (W3R) that co-express growth-promoting genes such as Wnt3a and three drug selection genes should empower us to efficiently make genetic modified hES cell lines for basic and translational research.展开更多
Let R(t)=u+ct-∑ I=1^N(t) Xi,t≥0 be the renewal risk model, with Fx(x)being the distribution function of the claim amount X. Let ψ(u) be the ruin probability with initial surplus u. Under the condition of F...Let R(t)=u+ct-∑ I=1^N(t) Xi,t≥0 be the renewal risk model, with Fx(x)being the distribution function of the claim amount X. Let ψ(u) be the ruin probability with initial surplus u. Under the condition of Fx(x) ∈ S^*(γ),y ≥ 0, by the geometric sum method, we derive the local asymptotic behavior for ψ(u,u + z] for every 0 ( z ( oo, On one hand, the asymptotic behavior of ψ(u) can be derived from the result obtained. On the other hand, the result of this paper can be applied to the insurance risk management of an insurance company.展开更多
Consider a multidimensional renewal risk model, in which the claim sizes {Xk, k ≥1} form a sequence of independent and identically distributed random vectors with nonnegative components that are allowed to be depende...Consider a multidimensional renewal risk model, in which the claim sizes {Xk, k ≥1} form a sequence of independent and identically distributed random vectors with nonnegative components that are allowed to be dependent on each other. The univariate marginal distributions of these vectors have consistently varying tails and finite means. Suppose that the claim sizes and inter-arrival times correspondingly form a sequence of independent and identically distributed random pairs, with each pair obeying a dependence structure. A precise large deviation for the multidimensional renewal risk model is obtained.展开更多
In this study, three kinds of spaces with different marketplace atmospheres, namely, the tea-drinking space, the commercial space and the courtyard space, are created with the aid of the marketplace culture characteri...In this study, three kinds of spaces with different marketplace atmospheres, namely, the tea-drinking space, the commercial space and the courtyard space, are created with the aid of the marketplace culture characteristics of the local blocks in Pengzhen Town and the catalyst theory, so as to achieve the purpose of activating the traditional blocks in Pengzhen Town. The design takes the marketplace culture as the entry point and the most vigorous points as the catalyst points to create a living space with strong marketplace flavor, thereby activating the economic and social activities of the traditional block and promotes the sustainable renewal of the cultural space.展开更多
The gray renewal GM (1,1) landslide prediction model was established by improving the gray model. Based on the established model, the author has made prediction of landslide deformation to the Xiangjiapo landslide and...The gray renewal GM (1,1) landslide prediction model was established by improving the gray model. Based on the established model, the author has made prediction of landslide deformation to the Xiangjiapo landslide and the Lianziya dangerous rock body. The results show that the gray renewal GM (1,1) model can supplement the new information in time and remove the old information which reduces the meaning of the information because of time lapse. Therefore, the model is closer to reality.展开更多
There are many problems,such as poverty,unemployment,poor infrastructure and how to improve the ecological environment,in the shantytowns of old industrial cities.Shantytowns are the most centralized areas with differ...There are many problems,such as poverty,unemployment,poor infrastructure and how to improve the ecological environment,in the shantytowns of old industrial cities.Shantytowns are the most centralized areas with different contradictions,referred to as the‘problem areas’of urban sustainable development.The shantytown transformation of old industrial cities is a typical process of unit community disintegration,which is reflected not only in the reconstruction of physical space but also in the community renewal of social spatial integration and culture reconstruction.Based on qualitative research,questionnaires and in-depth interviews,taking Tiexi Worker Village in Shenyang as a research case,this paper attempts to analyse the characteristics and driving forces of the community renewal of shantytown transformation in old industrial cities.We found that the physical space of Tiexi Worker Village has changed considerably,which is embodied in its land use structure,living environment and community service facilities,reflecting the development of community function from simple industrial function to comprehensive functions.The residents in this community have experienced a transformation from a period of homogeneity to one of heterogeneity.The social network of the community has been destroyed.Social stratification,social differentiation and higher fluidity have occurred.Community renewal is mainly affected by macro factors such as policy regulation,economic driving,condition constraints,and micro factors such as residents’choice of living space and willingness to renew their communities.The transformation policy of the old industrial zone and the development policy of the new urban area are the fundamental and deep-seated reasons for the renewal of Tiexi Worker Village,which determine the direction of the renewal and development of the community.The paid use of land and the development of the real estate industry are the direct stimulating factors for the renewal of Tiexi Worker Village,which become the direct reasons for the spatial transformation.The changes in the population in urban and rural areas and the promotion of traffic are the driving factors for the renewal of the community,while the choice of residents and their willingness regarding community renewal are the endogenous forces for promoting community renewal.Finally,the author attempts to put forward a model of the interlaced mechanism of the forming of community renewal at the macroscopic and microcosmic levels,which are the urban renewal and reconstruction and social space differentiation of community residents,respectively.展开更多
Partition of unity based numerical manifold method can solve continuous and discontinuous problems in a unified framework with a two-cover system,i.e.,the mathematical cover and physical cover.However,renewal of the t...Partition of unity based numerical manifold method can solve continuous and discontinuous problems in a unified framework with a two-cover system,i.e.,the mathematical cover and physical cover.However,renewal of the topology of the two-cover system poses a challenge for multiple crack propagation problems and there are few references.In this study,a robust and efficient strategy is proposed to update the cover system of the numerical manifold method in simulation of multiple crack propagation problems.The proposed algorithm updates the cover system with a bottom-up process:1)identification of fractured manifold elements according to the previous and latest crack tip position;and 2)local topological update of the manifold elements,physical patches,block boundary loops,and non-persistent joint loops according to the scenario classification of the propagating crack.The proposed crack tracking strategy and classification of the renewal cases promote a robust and efficient cover renewal algorithm for multiple crack propagation analysis.Three crack propagation examples show that the proposed algorithm performs well in updating the cover system.This cover renewal methodology can be extended for numerical manifold method with polygonal mathematical covers.展开更多
With the development and changes of the times,many cities have to face the problem of renewal.However,in the context of globalization,urban renewal also makes urban cultural characteristics and regional characteristic...With the development and changes of the times,many cities have to face the problem of renewal.However,in the context of globalization,urban renewal also makes urban cultural characteristics and regional characteristics inevitably missing.Therefore,we should pay attention to the protection and planning of regional historical and cultural heritages in the process of urban renewal,which plays an important role in the construction of urban characteristics and the shaping of city card.Xigu area of Tianjin also faces the problems of cultural loss and need for reconstruction,its function,layout,industrial structure and land use are adjusted and optimized in this article,with a view to showing the value of historical and cultural heritage and context of regional history.展开更多
基金Sponsored by Beijing Natural Science Foundation General Project(8212009)Organized Research Project of North China University of Technology in 2023(110051360023XN278).
文摘Urban development should rely on the form of architecture,and incorporating urban planning concepts into architectural design can better assist urban construction.Taking the design of Incheon Geomdan Cultural Complex in South Korea as an example,this paper analyzes how to reflect urban planning elements in architectural design,and studies the role and value of cultural complex architecture in urban development from multiple perspectives such as culture,ecological environment,and public space.It hopes to gain more research and design ideas to promote the development of cultural industries in the region,leverage the advantages of regional cultural formats,and create new cultural settlements in cities.
文摘Railways within the city carry the historical memory of urban development and are important industrial heritage resources.However,with urban development and changes in transportation functions,railways lose their original application value and are gradually left unused or even abandoned,affecting the vitality of the region.Taking the space around Xihuangcun Railway Station as the research object,the public activity space on both sides of the railway is reshaped through five strategies:function revitalization,traffic revitalization,heritage revitalization,spatial revitalization,and landscape revitalization,and the grey area of the city is transformed into a vibrant development zone of the city.
文摘The application of environment-behavior studies plays an important role in studying the renewal of shantytowns.One of the most humane ways of renewal is designing and constructing the necessary urban spatial environment from the perspective of human daily behavior.Most of the shantytown renovation projects currently carried out in China are mainly focused on demolition and reconstruction,which not only incurs high costs but also damages the original social structure and economic model.During the process of shantytown renewal,it should improve the urban landscape,living environment,and life quality of residents,and ensure the daily life of shantytown residents without increasing their economic burden,and preserve the traces of urban development.In order to achieve this goal,it should explore the renewal strategies of shantytowns from the perspective of environment-behavior studies through behavior maps,on-site research,and literature review.Updating and design from a human perspective often achieve faster and better development;the renewal of shantytowns should be a bottom-up approach and start from a grassroots perspective,completing the renovation design through the composition of the population and behavioral patterns.
文摘China’s move to promote a new round of large-scale equipment renewal is set to create an enormous green market.CHINA has placed much emphasis on encouraging large-scale equipment renewal and trade-ins of old consumer goods over the past year,with the topic being highlighted both at the Central Economic Conference held at the end of 2023 and in the government work report of 2024.
文摘Against the backdrop of incremental planning moving towards stock planning, strengtheningurban public space design to promote high-quality urban development has become a focus of attentionfor domestic scholars. Street is a linear element of urban public space, and it is of great significance forimproving the quality of urban public space by studying the micro renewal design strategy of street space.Based on the interpretation of two urban renewal cases, Wangjing Street in Beijing and Mengzhuiwan inChengdu, taking Baihuazhou area in Nanchang City as an example, this paper analyzes the main problemsin the current situation of street space in Baihuazhou area from three aspects: space use, traffic organization,and waterfront space creation, and explores the micro renewal design strategy of the street space.
基金Supported by Philosophy and Social Science Research Project of Hubei Provincial Department of Education(22Y066).
文摘The residential area of Wuchang Vehicle Factory is taken as a case to explore the protection and renewal strategies of industrial heritage residential areas.By analyzing the current situation of the residential area,issues such as functional decline,memory loss,and weakened community vitality are revealed.Three design concepts are proposed:building renovation,historical space renovation,and the introduction of cultural and creative industries,aiming to improve the living environment,showcase historical value,cultivate cultural and creative industries,promote economic transformation,and community vitality.This paper could provide reference for the protection and renewal of similar industrial heritage residential areas,and new ideas for the research and utilization of industrial heritage.By comprehensively considering heritage protection,cultural inheritance,and community development,systematic suggestions are proposed.
文摘Concept of urban renewal was elaborated,which for the protection of historic and cultural heritage not only provides a favorable opportunity of integrating neighboring environment and improving protection conditions,but also imposes threats such as destroying its historic images and patterns,degrading of survival environment.To properly protect historic and cultural heritage in the unceasing urban renewal,and make it a significant resource and feature of the city but not a barrier of urban development,empirical analysis and theoretical research were adopted to analyze and study current conditions and problems of the protection of historic and cultural heritage in Xi'an City from the dimension of urban renewal concept and present urban renewal of Xi'an.Moreover,through summarizing successful experience of other regions,specific strategies were given to protect historic and cultural heritage of Xi'an City in its urban renewal more scientifically and reasonably.
基金Supported by the Program for New Century Excellent Talents in University(NCET-100210)the National Natural Science Foundation of China(21076011 and 21276012)
文摘Hollow fiber renewal liquid membrane(HFRLM) method was proposed based on the surface renewal theory for removal of aniline from waste water. The system of aniline + D2 EHPA in kerosene + HCl was used. Aqueous layer diffusion in the feed phase is the rate-control step, and the influence of lumen side flow rate on the mass transfer is more significant than that on the shell side. The resistance of overall mass transfer is greatly reduced because of the mass transfer intensification in the renewal of liquid membrane on the lumen side. The driving force of mass transfer can be considered as a function of distribution equilibrium, and the overall mass transfer coefficient increases with the increase of p H in the feed solution, HCl concentration and D2 EHPA concentration, and decreases with the increase of initial aniline concentration. A mass transfer model is developed for HFRLM based on the surface renewal theory. The calculated results agree well with experimental results. The HFRLM process is a promising method for aniline wastewater treatment.
基金Supported by the China Scholarship Council and Guangdong Provincial Natural Science Foundation of China(No.950215).
文摘Based on the Danckwerts surface renewal model, a simple explicit expression of the enhancement factor in ozone absorption with a first order ozone self-decomposition and parallel second order ozonation reactions has been derived. The results are compared with our previous work based on the film theory. The 2,4-dichlorophenol destruction rate by ozonation is predicted using the enhancement factor model in this paper.
文摘We consider a random walk on Z in random environment with possible jumps {-L,…, -1, 1}, in the case that the environment {ωi : i ∈ Z} are i.i.d.. We establish the renewal theorem for the Markov chain of "the environment viewed from the particle" in both annealed probability and quenched probability, which generalize partially the results of Kesten (1977) and Lalley (1986) for the nearest random walk in random environment on Z, respectively. Our method is based on (L, 1)-RWRE formulated in Hong and Wang the intrinsic branching structure within the (2013).
基金supported by the National Natural Science Foundation of China(71801186)the National Natural Science Foundation of Guangdong(2018A030313829)+2 种基金the Science and Technology Innovation Guidance Project of Zhaoqing,Guangdong Province(201804031503)the higher education colleges and universities innovation strong school project of Guangdong(2016KTSCX153)the teaching reform project of Zhaoqing University(zlgc201745)
文摘The analytical renewal function(RF) is not tractable of the exponential Weibull(EW) distribution. In the proposed model, the n-fold convolution of the EW cumulative distribution function(CDF) is approximated by a n-fold convolutions of Gamma and normal CDFs. We obtain the EW RF by a series approximation model. The method is very simple in the computation. When the parameters are unknown, we present the asymptotic confidence interval of the RF. The validity of the asymptotic confidence interval is checked via some numerical experiments.
文摘The novel synergistic mixture of TBP and Cyanex-272 is used as the extractant in the hollow fiber renewal liquid membrane(HFRLM) technique for Zr/Hf separation.The effects of the chemical and operational parameters such as HNO3 concentration in the donor phase,NH4 F concentration in the acceptor phase,Cyanex-272 and TBP concentration in the liquid membrane phase,the lumen and shell side flow rates,and aqueous/organic volume ratio on the mass transfer and separation performance of HFRLM method were investigated.The obtained results reveal the intensification potential of proposed HFRLM technique for selective extraction of Zr over Hf with separation factor higher than 100.The HFRLM method provides two times higher mass transfer flux in comparison with hollow fiber supported liquid membrane(HFSLM).Also,the HFRLM method shows satisfactory stability for 700 min of continuous operation.The Zr ion transport through the LM phase follows the coupled co-transport mechanism and the diffusion in the renewal layer is recognized as the rate-controlling step in the HFRLM process.Moreover,the Zr mass transfer coefficient and molar flux in the HFRLM method are calculated in the range of 1×10^-8 to 8.4×10^-7 m·s^-1 and 4.9×10^-6 to 20.1×10^-6 mol·m^-2·s^-1,respectively.
文摘We previously showed that Wnt3a could stimulate human embryonic stem (hES) cell proliferation and affect cell fate determination. In the absence of feeder cell--derived factors, hES cells cultured under a feeder-free condition survived and proliferated poorly. Adding recombinant Wnt3a in the absence of feeder cell derived-factors stimulated hES cell proliferation but also differentiation. In the present study, we further extended our analysis to other Wnt ligands such as Wntl and Wnt5a. While Wntl displayed a similar effect on hES cells as Wnt3a, Wnt5a had little effect in this system. Wnt3a and Wntl enhanced proliferation of undifferentiated hES cells when feeder-derived self-renewal factors and bFGF are also present. To explore the possibility to promote the proliferation of undifferentiated hES cells by activating the Wnt signaling, we overexpressed Wnt3a or Wntl gene in immortalized human adult fibroblast (HAFi) cells that are superior in supporting long-term growth of undifferentiated hES cells than primary mouse embryonic fibroblasts. HAFi cells with or without a Wnt tmnsgene can be propagated indefinitely. Over-expression of the Wnt3a gene significantly enhanced the ability of HAFi feeder cells to support the undifferentiated growth of 3 different hES cell lines we tested. Co-expression of three commonly-used drug selection genes in Wnt3a-overpressing HAFi cells further enabled us to select rare hES clones after stable transfection or transduction. These immortalized engineered feeder cells (W3R) that co-express growth-promoting genes such as Wnt3a and three drug selection genes should empower us to efficiently make genetic modified hES cell lines for basic and translational research.
基金Supported by the National Natural Science Foundation of China (70273029)
文摘Let R(t)=u+ct-∑ I=1^N(t) Xi,t≥0 be the renewal risk model, with Fx(x)being the distribution function of the claim amount X. Let ψ(u) be the ruin probability with initial surplus u. Under the condition of Fx(x) ∈ S^*(γ),y ≥ 0, by the geometric sum method, we derive the local asymptotic behavior for ψ(u,u + z] for every 0 ( z ( oo, On one hand, the asymptotic behavior of ψ(u) can be derived from the result obtained. On the other hand, the result of this paper can be applied to the insurance risk management of an insurance company.
基金Supported by the National Natural Science Foundation of China(Nos.11571058&11301481)Humanities and Social Science Foundation of the Ministry of Education of China(No.17YJC910007)+1 种基金Zhejiang Provincial Natural Science Foundation of China(No.LY17A010004)Fundamental Research Funds for the Central Universities(No.DUT17LK31)
文摘Consider a multidimensional renewal risk model, in which the claim sizes {Xk, k ≥1} form a sequence of independent and identically distributed random vectors with nonnegative components that are allowed to be dependent on each other. The univariate marginal distributions of these vectors have consistently varying tails and finite means. Suppose that the claim sizes and inter-arrival times correspondingly form a sequence of independent and identically distributed random pairs, with each pair obeying a dependence structure. A precise large deviation for the multidimensional renewal risk model is obtained.
文摘In this study, three kinds of spaces with different marketplace atmospheres, namely, the tea-drinking space, the commercial space and the courtyard space, are created with the aid of the marketplace culture characteristics of the local blocks in Pengzhen Town and the catalyst theory, so as to achieve the purpose of activating the traditional blocks in Pengzhen Town. The design takes the marketplace culture as the entry point and the most vigorous points as the catalyst points to create a living space with strong marketplace flavor, thereby activating the economic and social activities of the traditional block and promotes the sustainable renewal of the cultural space.
文摘The gray renewal GM (1,1) landslide prediction model was established by improving the gray model. Based on the established model, the author has made prediction of landslide deformation to the Xiangjiapo landslide and the Lianziya dangerous rock body. The results show that the gray renewal GM (1,1) model can supplement the new information in time and remove the old information which reduces the meaning of the information because of time lapse. Therefore, the model is closer to reality.
基金Under the auspices of Liaoning Revitalization Talents Program(No.XLYC1807249)Liaoning Social Science Planning Fund Project(No.L18BGL031)Project of Education Department of Liaoning Province(No.WQN201709)。
文摘There are many problems,such as poverty,unemployment,poor infrastructure and how to improve the ecological environment,in the shantytowns of old industrial cities.Shantytowns are the most centralized areas with different contradictions,referred to as the‘problem areas’of urban sustainable development.The shantytown transformation of old industrial cities is a typical process of unit community disintegration,which is reflected not only in the reconstruction of physical space but also in the community renewal of social spatial integration and culture reconstruction.Based on qualitative research,questionnaires and in-depth interviews,taking Tiexi Worker Village in Shenyang as a research case,this paper attempts to analyse the characteristics and driving forces of the community renewal of shantytown transformation in old industrial cities.We found that the physical space of Tiexi Worker Village has changed considerably,which is embodied in its land use structure,living environment and community service facilities,reflecting the development of community function from simple industrial function to comprehensive functions.The residents in this community have experienced a transformation from a period of homogeneity to one of heterogeneity.The social network of the community has been destroyed.Social stratification,social differentiation and higher fluidity have occurred.Community renewal is mainly affected by macro factors such as policy regulation,economic driving,condition constraints,and micro factors such as residents’choice of living space and willingness to renew their communities.The transformation policy of the old industrial zone and the development policy of the new urban area are the fundamental and deep-seated reasons for the renewal of Tiexi Worker Village,which determine the direction of the renewal and development of the community.The paid use of land and the development of the real estate industry are the direct stimulating factors for the renewal of Tiexi Worker Village,which become the direct reasons for the spatial transformation.The changes in the population in urban and rural areas and the promotion of traffic are the driving factors for the renewal of the community,while the choice of residents and their willingness regarding community renewal are the endogenous forces for promoting community renewal.Finally,the author attempts to put forward a model of the interlaced mechanism of the forming of community renewal at the macroscopic and microcosmic levels,which are the urban renewal and reconstruction and social space differentiation of community residents,respectively.
基金Project(51321065,51479191,11672360)supported by the National Natural Science Foundation of China。
文摘Partition of unity based numerical manifold method can solve continuous and discontinuous problems in a unified framework with a two-cover system,i.e.,the mathematical cover and physical cover.However,renewal of the topology of the two-cover system poses a challenge for multiple crack propagation problems and there are few references.In this study,a robust and efficient strategy is proposed to update the cover system of the numerical manifold method in simulation of multiple crack propagation problems.The proposed algorithm updates the cover system with a bottom-up process:1)identification of fractured manifold elements according to the previous and latest crack tip position;and 2)local topological update of the manifold elements,physical patches,block boundary loops,and non-persistent joint loops according to the scenario classification of the propagating crack.The proposed crack tracking strategy and classification of the renewal cases promote a robust and efficient cover renewal algorithm for multiple crack propagation analysis.Three crack propagation examples show that the proposed algorithm performs well in updating the cover system.This cover renewal methodology can be extended for numerical manifold method with polygonal mathematical covers.
基金National Nature Science Foundation of China(51608009)Support Plan for Construction of Highlevel Teacher Team in Colleges and Universities of Beijing in 2019+1 种基金Support Program for Top-notch Young Talents(CIT&TCD201904010)Fund of Beijing Research Center of Urban Governance(20XN237).
文摘With the development and changes of the times,many cities have to face the problem of renewal.However,in the context of globalization,urban renewal also makes urban cultural characteristics and regional characteristics inevitably missing.Therefore,we should pay attention to the protection and planning of regional historical and cultural heritages in the process of urban renewal,which plays an important role in the construction of urban characteristics and the shaping of city card.Xigu area of Tianjin also faces the problems of cultural loss and need for reconstruction,its function,layout,industrial structure and land use are adjusted and optimized in this article,with a view to showing the value of historical and cultural heritage and context of regional history.