面对人工智能技术驱动的深刻变革,高校图书馆正从传统的资源中心向创新中心转型。为探索开放创新生态的构建路径,文章以美国国会图书馆的Innovator in Residence(IIR)项目为核心范例,综合运用案例分析与比较研究方法,系统剖析了其运作...面对人工智能技术驱动的深刻变革,高校图书馆正从传统的资源中心向创新中心转型。为探索开放创新生态的构建路径,文章以美国国会图书馆的Innovator in Residence(IIR)项目为核心范例,综合运用案例分析与比较研究方法,系统剖析了其运作机制、核心理念以及在不同机构中的多元化实践样态,构建了一个由AI技术与AI素养教育双核驱动,以开放创新平台、创新服务机制、创新能力体系、创新支持环境为四根支柱的生态系统模型,并结合中国国情提出了本土化实施策略,为我国高校图书馆“因校制宜”地构建多层次、动态演进的创新项目体系,提供了理论高度与实践价值兼备的行动蓝图。展开更多
Summer residential tourism is the future trend in China because of tourists’living quality improvement,heat crisis,rising market demand,and optimization of the destinations’residential environment,transport and acce...Summer residential tourism is the future trend in China because of tourists’living quality improvement,heat crisis,rising market demand,and optimization of the destinations’residential environment,transport and accessibility.Compared with summer tourism and vacation tourism,summer residential tourism had got less attention and lacks in prospective and preventive research.Hence,this study focused on potential assessment,pattern recognition and phase segmentation of 32 residential tourism destinations in China selected from 4 lists.An index system of 16 indicators from 5 dimensions was established as Summer Residence Index(SRI),and Range method,Entropy weight method and Composite index method were chosen as the core methods.Three main conclusions were as follows.(1)Only 2 typical districts’SRI value were near to 0.6,and 4 destinations were below 0.1,about 26 destinations were at medium-level,which indicated that China’s summer residential tourism was not so popular and only few destinations have stepped into a higher level.(2)Seven patterns could be recognized based on the contribution of the 5 dimensions to SRI value,including 3 single-factor driven patterns and 4 compound factors driven patterns.(3)Like tourist area life cycle(TALC),Unconscious stage,Initial stage,Developmental stage and Maturity stage could be segmented for summer residential destinations with the value of below 0.1,0.1-0.3,0.3-0.5,and above 0.5.Four destinations were under Unconscious stage.Twenty-two destinations were at initiate stage.Only 4 destinations have stepped into development stage and 2 at maturity stage.China’summer residential tourism has just started and has a better prospect.This study is just an attempt and needs further consideration,for example,a tracking study of SRI calculation for each year will be carried to justify the effectiveness of SRI and to check the rationality of the empirical results.As time goes on,policies in housing,residential estate and other aspects should be included as a factor in the SRI index.Data availability should be optimized because of better data sources and new technologies.Some other districts or cities in 2 batches of national Comprehensive Tourism Demonstration Zones(CTDZs)pilots and provincial CTDZs will be further selections of summer residential tourism destinations.展开更多
Macrophages in the brain barrier system include microglia in the brain parenchyma,border-associated macrophages at the brain’s borders,and recruited macrophages.They are responsible for neural development,maintenance...Macrophages in the brain barrier system include microglia in the brain parenchyma,border-associated macrophages at the brain’s borders,and recruited macrophages.They are responsible for neural development,maintenance of homeostasis,and orchestrating immune responses.With the rapid exploitation and development of new technologies,there is a deeper understanding of macrophages in the brain barrier system.Here we review the origin,development,important molecules,and functions of macrophages,mainly focusing on microglia and border-associated macrophages.We also highlight some advances in single-cell sequencing and significant cell markers.We anticipate that more advanced methods will emerge to study resident and recruited macrophages in the future,opening new horizons for neuroimmunology and related peripheral immune fields.展开更多
With rapid development of economy and emergence of more and more high-grade residences,it had highlighted that high-grade residence was the inevitable tendency of economic development and urban construction.Based on t...With rapid development of economy and emergence of more and more high-grade residences,it had highlighted that high-grade residence was the inevitable tendency of economic development and urban construction.Based on the fact that high-grade residences paid more attention to harmony of human and architecture with nature and required higher for landscaping,the paper emphasized that landscape quality of high-grade residences was the key factor deciding quality of the residence.In view of insufficiencies of plant landscaping planning in high-grade residences at home and abroad,by taking high-grade residences in Hangzhou City for example,analysis had been conducted by selecting typical cases.It pointed out that plants disposition in high-grade residences was unreasonable,architectures and landscapes were isolated,and greening ratio was stressed while design was neglected.And then,corresponding solutions had been proposed.In terms of plants selection,it should reasonably utilize native tree species,and properly select new and high-quality plant species.In terms of harmonious unity between plant landscape and architecture,it should lay stress on unity between sensory design and comfort design.In terms of plant design and disposition,it should stick to the theme of "residential environment",so as to rationalize plant design and disposition,and create more comfortable residential environment.展开更多
In the chemical vapor deposition（CVD） process of C/C composites,the dynamics and mechanism of precursor gas flowing behavior were analyzed mathematically,in which the precursor gas was infiltrated by the pressure di...In the chemical vapor deposition（CVD） process of C/C composites,the dynamics and mechanism of precursor gas flowing behavior were analyzed mathematically,in which the precursor gas was infiltrated by the pressure difference of the gas flowing through felt.Differential equations were educed which characterized the relations among the pressure inside the felt,the pressure outside the felt of the precursor gas and the porosity of the felt as a function of CVD duration.The gas residence time during the infiltration process through the felt was obtained from the differential equations.The numerical verification is in good agreement with the practical process,indicating the good reliability of the current mathematical model.展开更多
Starting from the analysis on aesthetic implication of seaweed residence in Jiaodong,field study was conducted.With existing residence as the case study,the pervasive and simple ecological value,practical significance...Starting from the analysis on aesthetic implication of seaweed residence in Jiaodong,field study was conducted.With existing residence as the case study,the pervasive and simple ecological value,practical significance and sustainability of traditional residences were explored,so as to provide a theoretical basis and practical reference for new residential design of ecological value.展开更多
Considering the construction of rural residence as a significant content of constructing the new socialist countryside,problems of present rural housing in energy conservation and comfort level are analyzed.To develop...Considering the construction of rural residence as a significant content of constructing the new socialist countryside,problems of present rural housing in energy conservation and comfort level are analyzed.To develop eco-residence in new countryside,improve living conditions of local residents,save energy and reduce carbon emission,responsive capability of natural organisms to climate is introduced into architectural design,and concept of responsive design is analyzed.In view of actual regional and climatic characteristics,it is proposed that responsive design is able to solve many problems of present rural housing,then responsive structures in traditional Chinese dwellings are introduced,such as removable window,latticed wooden ventilation door,courtyard with hinged cover,transom and so on.On this basis,a dwelling unit of row house on suburban plains of Zhengzhou City is taken for a living example of responsive design from the perspectives of flexible corridor and courtyard,controllable natural wind channel,application of plant's responsive characteristics,flexible close building and controllable cavity space,to build comfortable living environments.展开更多
The flow behavior of gravity-driven falling film of non-conductive high viscosity polymer fluids on an industrial-scale vertical wavy wall was investigated in terms of film thickness and residence time distribution by...The flow behavior of gravity-driven falling film of non-conductive high viscosity polymer fluids on an industrial-scale vertical wavy wall was investigated in terms of film thickness and residence time distribution by numerical simulation and experiment.Falling film flow of high viscosity fluids was found to be steady on a vertical wavy wall in the presence of the large film thickness.The comparison between numerical simulation and experiment for the film thickness both in crest and trough of wavy wall showed good agreement.The simulation results of average residence time of falling film flow with different viscous fluids were also consistent with the experimental results.This work provides the initial insights of how to evaluate and optimize the falling film flow system of polymer fluid.展开更多
Objective To examine the effect of hydraulic residence time （HRT） on the performance and stability, to treat dilute wastewater at different operational temperatures in a carrier anaerobic baffled reactor （CABR）, a...Objective To examine the effect of hydraulic residence time （HRT） on the performance and stability, to treat dilute wastewater at different operational temperatures in a carrier anaerobic baffled reactor （CABR）, and hence to gain a deeper insight into microbial responses to hydraulic shocks on the base of the relationships among macroscopic performance, catabolic intermediate, and microcosmic alternation. Methods COD, VFAs, and microbial activity were detected with constant feed strength （300 mg/L） at different HRTs （9-18 h） and temperatures （10℃-28℃） in a CABR. Results The removal efficiencies declined with the decreases of HRTs and temperatures. However, the COD removal load was still higher at short HRT than at long HRT. Devastating reactor performance happened at temperature of 10℃ and at HRT of 9 h. HRTs had effect on the VFAs in the reactor slightly both at high and low temperatures, but the reasons differed from each other. Microbial activity was sensitive to indicate changes of environmental and operational parameters in the reactor. Conclusion The CABR offers to certain extent an application to treat dilute wastewater under a hydraulic-shock at temperatures from 10℃to 28℃.展开更多
The paper has analyzed decorative characteristics and architectural style of Leichang Former Residence which have been summarized as precise axial space sequence that can be divided into dragon gate, central room and ...The paper has analyzed decorative characteristics and architectural style of Leichang Former Residence which have been summarized as precise axial space sequence that can be divided into dragon gate, central room and drawing room. It has explained the spatial-temporal view of "the unity between heaven and human" and human's subjective ideological connotation in Leichang Former Residence. From the perspectives of the spiritual connotation of roof decorations, grading system of roofing tiles and manifestation form, it has deeply revealed the important expressive force and representativeness of roofs in architectural group, pointed out its aesthetic feature and spiritual restriction to architectures even human's behavior, and showed that the roof is the architectural factor directly manifesting "rituality" and "the unity between human and heaven" in Chinese traditional culture.展开更多
Groundwater residence time is an important indicator of hydrological cycle and essential for water resources development and utilization. In this paper, groundwater residence time in non-flood season, flood season and...Groundwater residence time is an important indicator of hydrological cycle and essential for water resources development and utilization. In this paper, groundwater residence time in non-flood season, flood season and water year has been determined from daily streamflow hydrograph of ten hydrological stations in Wudinghe River Basin located in the middle reaches of the Yellow River Basin. Results have showed that： baseflow recession constant in Wudinghe River Basin ranges from 0.72 to 0.94 with a larger recession rate in flood season than that in non-flood season. Spatially, the recession rate of baseflow in loess area is the biggest, but is the smallest in the sandy area. The half-residence time of groundwater varies from 1.8 to 45.5 days while overall residence time of groundwater is between 34 and 342 days in different sub-basins of the Wudinghe River Basin. The annual average overall residence time of groundwater decreases from 117 days in the upper reaches to 73 days in the lower reaches.展开更多
Driven by the policy of "balancing urban and rural development", urbanization in China has been accelerated and agricultural population transferred to urban areas, which guarantees the improvement of life qu...Driven by the policy of "balancing urban and rural development", urbanization in China has been accelerated and agricultural population transferred to urban areas, which guarantees the improvement of life quality and living environment of rural and agricultural population. The urbanization has always been accompanied by national economic development and social progress, relocation and development of rural areas have become a social issue for a certain time. Therefore, it is imperative to explore a series of concrete, well-timed and practical measures for settling rural population, figure out proper modes, materials and methods for rural residence planning and construction under the new conditions, and provide relevant operation and theoretical support. Problems in mountainous rural areas of China were proposed as great population but limited land resources, backward construction techniques, and residences not valuing low carbon or environment protection. In view of these problems, construction techniques suitable for actual conditions of rural areas were explored, energy-saving building materials combined, the style of "dragon sucking water" for mountainous rural areas was proposed, design advantages and details of this architectural model were analyzed.展开更多
The cyclonic static micro-bubble column flotation (FCSMC) is an effective separation device for fine particle treatment. The high mineralization rate and short flotation time of this equipment can be attributed to its...The cyclonic static micro-bubble column flotation (FCSMC) is an effective separation device for fine particle treatment. The high mineralization rate and short flotation time of this equipment can be attributed to its unique cyclonic force field. It also has been observed that the presence of a cyclonic force field leads to a lower bottom separation size limit and a reduction of unselective entrainment. The collection zone of the column is considered to consist of two parts,a column separation zone and a cyclonic zone. Total recovery of the collection zone was developed. For our study,we analyzed the particle movement in the cyclonic zone. Particle residence time equations for the cyclonic zone were de-rived by force analysis. Results obtained in this study provide a theoretical foundation for the design and scale-up of the FCSMC.展开更多
The importance of dissolved organic phosphorus(DOP) as a potential nutrient source for primary producers in marine systems has been recognized for up to eight decades, but currently, the understanding of the biogeoche...The importance of dissolved organic phosphorus(DOP) as a potential nutrient source for primary producers in marine systems has been recognized for up to eight decades, but currently, the understanding of the biogeochemistry of DOP is in its infancy. In the present study, monthly data between 2000 and 2014 were used to analyze the temporal and spatial distributions of DOP in the Mir Bay, the northern South China Sea. The DOP residence time(TDOP) was also investigated using a simple regression analysis in combination with chlorophyll a(Chl a) measurements while excess DOP(ΔDOP), produced by the biogeochemical processes of autotrophic production and heterotrophic removal, was determined using a two-component mixing mass-balance model in combination with salinity measurements. The results showed that the DOP concentration was(0.017±0.010) mg/L higher in the surface-water compared with the bottom-water and higher in the inner Tolo Harbour and waters adjacent to Shatoujiao compared with the main zone of the bay. Although seasonal changes and annual variability in the DOP were small, the surface DOP concentration was higher in the wet season(April–September)than in the dry season(October–March) due to the impacts of seaward discharges and atmospheric deposition into the bay. Measurement and regression results showed that the DOP release rate from phytoplankton production was about 1.83(gP)/(gChl a) and the TDOP was about 7 d, which implied that the DOP cycle in the bay was rapid. The ΔDOP was calculated from the model to be about 0.000 mg/L in the main zone of the bay and about 0.002 mg/L in the inner Tolo Harbour and waters adjacent to Shaotoujiao, suggesting that the autotrophic production of DOP was almost balanced by the heterotrophic removal in the main zone of the bay and dominated in the inner Tolo Harbour and waters adjacent to Shaotoujiao. In conclusion, the Mirs Bay is very productive and fairly heterotrophic.展开更多
As an important design factor for constructed wetlands,hydraulic retention time and its distribution will affect the treatment performance.Instantaneously injected sodium chloride tracers were used to obtain residence...As an important design factor for constructed wetlands,hydraulic retention time and its distribution will affect the treatment performance.Instantaneously injected sodium chloride tracers were used to obtain residence time distributions of the lab scale subsurface flow constructed wetland.Considering the presence of trailing and multiple peaks of the tracer breakthrough curve,the multi flow dispersion model(MFDM)was used to fit the experimental tracer breakthrough curves.According to the residual sum of squares and comparison between the experimental values and simulated values of the tracer concentration,MFDM could fit the residence time distribution(RTD)curve satisfactorily,the results of which also reflected the layered structure of wetland cells,thus to give reference for application of MFDM to the same kind of subsurface flow constructed wetlands.展开更多
Exploring long-term residence among the urban floating population is crucial to understanding urban growth in China,particularly since the 2008 financial crisis.By using China Migrants Dynamic Survey data for 2012–20...Exploring long-term residence among the urban floating population is crucial to understanding urban growth in China,particularly since the 2008 financial crisis.By using China Migrants Dynamic Survey data for 2012–2014,China Labor-force Dynamics Survey data for 2014–2016,and macroscale urban matched data,we analyzed the spatial pattern of long-term residential behavior in China’s urban floating population in 2012–2016 and developed an urban spatial utility equilibrium model containing‘macro’urban factors and‘micro’individual and household factors to explain the pattern.The results first revealed that long-term residence is defined as≥6 yr for the urban floating population in China.Second,members of this population are more likely to be long-term residents of the megacities in the three urban agglomerations in eastern China as well as of small and medium-sized cities in western and northeastern China,whereas short-term residence is more likely in cities in central China and near the three urban agglomerations.Third,urban population density and housing prices,both have a significant U-shaped effect,are main factors affecting the spatial pattern of long-term residence.展开更多
On the basis of expounding the status quo of rural residents' residence, the thesis notes that influenced by the weak foundation of rural economy, the characteristic of mountain landscape, smallholder consciousnes...On the basis of expounding the status quo of rural residents' residence, the thesis notes that influenced by the weak foundation of rural economy, the characteristic of mountain landscape, smallholder consciousness, shortage of capital and other factors, the rural residents in Chongqing City mainly live scattered. In addition to opportunities of the expansion and drive of city, rural market development, rural resources development, rural industrial development, and rural ecological migration, the model of urban development promotion, the model of market development drive, the model of land development drive, the model of rural industry construction and the model of resettlement and reconstruction are advocated in order to guide the rural residents to adopt relative centralized residence. The suggestions concerning guiding rural residents' relative centralized residence are put forward as follows: firstly, act according to circumstances and conduct scientific planning and design; secondly, propagate extensively and activate famers' willingness; thirdly, first experiment and exert the exemplary guide; fourthly, perfect policy and guarantee farmers' benefit; fifthly, strengthen leadership and decrease the risk of centralized residence; sixthly, boost gradually and realize moderate centralized residence.展开更多
Geothermal resources are increasingly gaining attention as a competitive,clean energy source to address the energy crisis and mitigate climate change.The Wugongshan area,situated in the southeast coast geothermal belt...Geothermal resources are increasingly gaining attention as a competitive,clean energy source to address the energy crisis and mitigate climate change.The Wugongshan area,situated in the southeast coast geothermal belt of China,is a typical geothermal anomaly and contains abundant medium-and low-temperature geothermal resources.This study employed hydrogeochemical and isotopic techniques to explore the cyclic evolution of geothermal water in the western Wugongshan region,encompassing the recharge origin,water-rock interaction mechanisms,and residence time.The results show that the geothermal water in the western region of Wugongshan is weakly alkaline,with low enthalpy and mineralization levels.The hydrochemistry of geothermal waters is dominated by Na-HCO_(3)and Na-SO_(4),while the hydrochemistry types of cold springs are all Na-HCO_(3).The hydrochemistry types of surface waters and rain waters are NaHCO_(3)or Ca-HCO_(3).The δD and δ^(18)O values reveal that the geothermal waters are recharged by atmospheric precipitation at an altitude between 550.0 and 1218.6 m.Molar ratios of maj or solutes and isotopic compositions of^(87)Sr/^(86)Sr underscore the significant role of silicate weathering,dissolution,and cation exchange in controlling geothermal water chemistry.Additionally,geothermal waters experienced varying degrees of mixing with cold water during their ascent.Theδ^(13)C values suggest that the primary sources of carbon in the geothermal waters were biogenic and organic.Theδ^(34)S value suggests that the sulfates in geothermal water originate from sulfide minerals in the surrounding rock.Age dating using 3H and^(14)C isotopes suggests that geothermal waters have a residence time exceeding 1 kaBP and undergo a long-distance cycling process.展开更多
How to identify the nested structure of a three-dimensional(3D)hierarchical groundwater flow system is always a difficult problem puzzling hydrogeologists due to the multiple scales and complexity of the 3D flow field...How to identify the nested structure of a three-dimensional(3D)hierarchical groundwater flow system is always a difficult problem puzzling hydrogeologists due to the multiple scales and complexity of the 3D flow field.The main objective of this study was to develop a quantitative method to partition the nested groundwater flow system into different hierarchies in three dimensions.A 3D numerical model with topography derived from the real geomatic data in Jinan,China was implemented to simulate groundwater flow and residence time at the regional scale while the recharge rate,anisotropic permeability and hydrothermal effect being set as climatic and hydrogeological variables in the simulations.The simulated groundwater residence time distribution showed a favorable consistency with the spatial distribution of flow fields.The probability density function of residence time with discontinuous segments indicated the discrete nature of time domain between different flow hierarchies,and it was used to partition the hierarchical flow system into shallow/intermediate/deep flow compartments.The changes in the groundwater flow system can be quantitatively depicted by the climatic and hydrogeological variables.This study provides new insights and an efficient way to analyze groundwater circulation and evolution in three dimensions from the perspective of time domain.展开更多
文摘面对人工智能技术驱动的深刻变革,高校图书馆正从传统的资源中心向创新中心转型。为探索开放创新生态的构建路径,文章以美国国会图书馆的Innovator in Residence(IIR)项目为核心范例,综合运用案例分析与比较研究方法,系统剖析了其运作机制、核心理念以及在不同机构中的多元化实践样态,构建了一个由AI技术与AI素养教育双核驱动,以开放创新平台、创新服务机制、创新能力体系、创新支持环境为四根支柱的生态系统模型,并结合中国国情提出了本土化实施策略,为我国高校图书馆“因校制宜”地构建多层次、动态演进的创新项目体系,提供了理论高度与实践价值兼备的行动蓝图。
基金Supported by Ningxia Natural Science Foundation(2024AAC03100).
文摘Summer residential tourism is the future trend in China because of tourists’living quality improvement,heat crisis,rising market demand,and optimization of the destinations’residential environment,transport and accessibility.Compared with summer tourism and vacation tourism,summer residential tourism had got less attention and lacks in prospective and preventive research.Hence,this study focused on potential assessment,pattern recognition and phase segmentation of 32 residential tourism destinations in China selected from 4 lists.An index system of 16 indicators from 5 dimensions was established as Summer Residence Index(SRI),and Range method,Entropy weight method and Composite index method were chosen as the core methods.Three main conclusions were as follows.(1)Only 2 typical districts’SRI value were near to 0.6,and 4 destinations were below 0.1,about 26 destinations were at medium-level,which indicated that China’s summer residential tourism was not so popular and only few destinations have stepped into a higher level.(2)Seven patterns could be recognized based on the contribution of the 5 dimensions to SRI value,including 3 single-factor driven patterns and 4 compound factors driven patterns.(3)Like tourist area life cycle(TALC),Unconscious stage,Initial stage,Developmental stage and Maturity stage could be segmented for summer residential destinations with the value of below 0.1,0.1-0.3,0.3-0.5,and above 0.5.Four destinations were under Unconscious stage.Twenty-two destinations were at initiate stage.Only 4 destinations have stepped into development stage and 2 at maturity stage.China’summer residential tourism has just started and has a better prospect.This study is just an attempt and needs further consideration,for example,a tracking study of SRI calculation for each year will be carried to justify the effectiveness of SRI and to check the rationality of the empirical results.As time goes on,policies in housing,residential estate and other aspects should be included as a factor in the SRI index.Data availability should be optimized because of better data sources and new technologies.Some other districts or cities in 2 batches of national Comprehensive Tourism Demonstration Zones(CTDZs)pilots and provincial CTDZs will be further selections of summer residential tourism destinations.
基金supported by Ministry of Science and Technology China Brain Initiative Grant,No.2022ZD0204702(to ZY)the National Natural Science Foundation of China,No.82371357(to LC)+2 种基金Foundation for Military Medicine,No.16QNP085(to ZY)Navy Medical University Basic Medical College“Yi Zhang”Basic Medical Talent Development and Support Program,Nos.JCYZRC-D-022(to TC)and JCYZRC-D-024(to HD)Science and Technology Innovation Special Fund of Shanghai Baoshan District,No.2023-E-05(to YW).
文摘Macrophages in the brain barrier system include microglia in the brain parenchyma,border-associated macrophages at the brain’s borders,and recruited macrophages.They are responsible for neural development,maintenance of homeostasis,and orchestrating immune responses.With the rapid exploitation and development of new technologies,there is a deeper understanding of macrophages in the brain barrier system.Here we review the origin,development,important molecules,and functions of macrophages,mainly focusing on microglia and border-associated macrophages.We also highlight some advances in single-cell sequencing and significant cell markers.We anticipate that more advanced methods will emerge to study resident and recruited macrophages in the future,opening new horizons for neuroimmunology and related peripheral immune fields.
文摘With rapid development of economy and emergence of more and more high-grade residences,it had highlighted that high-grade residence was the inevitable tendency of economic development and urban construction.Based on the fact that high-grade residences paid more attention to harmony of human and architecture with nature and required higher for landscaping,the paper emphasized that landscape quality of high-grade residences was the key factor deciding quality of the residence.In view of insufficiencies of plant landscaping planning in high-grade residences at home and abroad,by taking high-grade residences in Hangzhou City for example,analysis had been conducted by selecting typical cases.It pointed out that plants disposition in high-grade residences was unreasonable,architectures and landscapes were isolated,and greening ratio was stressed while design was neglected.And then,corresponding solutions had been proposed.In terms of plants selection,it should reasonably utilize native tree species,and properly select new and high-quality plant species.In terms of harmonious unity between plant landscape and architecture,it should lay stress on unity between sensory design and comfort design.In terms of plant design and disposition,it should stick to the theme of "residential environment",so as to rationalize plant design and disposition,and create more comfortable residential environment.
基金Projects (50702078,50874123) supported by the National Natural Science Foundation of ChinaProject (2009AA03Z536) supported by the National High-tech Research and Development Program of China+1 种基金Project (2011CB606306) supported by the National Research Program of ChinaProject supported by the Program for New Century Excellent Talents in University of China
文摘In the chemical vapor deposition（CVD） process of C/C composites,the dynamics and mechanism of precursor gas flowing behavior were analyzed mathematically,in which the precursor gas was infiltrated by the pressure difference of the gas flowing through felt.Differential equations were educed which characterized the relations among the pressure inside the felt,the pressure outside the felt of the precursor gas and the porosity of the felt as a function of CVD duration.The gas residence time during the infiltration process through the felt was obtained from the differential equations.The numerical verification is in good agreement with the practical process,indicating the good reliability of the current mathematical model.
文摘Starting from the analysis on aesthetic implication of seaweed residence in Jiaodong,field study was conducted.With existing residence as the case study,the pervasive and simple ecological value,practical significance and sustainability of traditional residences were explored,so as to provide a theoretical basis and practical reference for new residential design of ecological value.
文摘Considering the construction of rural residence as a significant content of constructing the new socialist countryside,problems of present rural housing in energy conservation and comfort level are analyzed.To develop eco-residence in new countryside,improve living conditions of local residents,save energy and reduce carbon emission,responsive capability of natural organisms to climate is introduced into architectural design,and concept of responsive design is analyzed.In view of actual regional and climatic characteristics,it is proposed that responsive design is able to solve many problems of present rural housing,then responsive structures in traditional Chinese dwellings are introduced,such as removable window,latticed wooden ventilation door,courtyard with hinged cover,transom and so on.On this basis,a dwelling unit of row house on suburban plains of Zhengzhou City is taken for a living example of responsive design from the perspectives of flexible corridor and courtyard,controllable natural wind channel,application of plant's responsive characteristics,flexible close building and controllable cavity space,to build comfortable living environments.
基金Supported by the National Key Research and Development Program of China(2016YFB0303000)the National Natural Science Foundation of China(51803187)Zhejiang Provincial Natural Science Foundation of China(LQ18E030011)
文摘The flow behavior of gravity-driven falling film of non-conductive high viscosity polymer fluids on an industrial-scale vertical wavy wall was investigated in terms of film thickness and residence time distribution by numerical simulation and experiment.Falling film flow of high viscosity fluids was found to be steady on a vertical wavy wall in the presence of the large film thickness.The comparison between numerical simulation and experiment for the film thickness both in crest and trough of wavy wall showed good agreement.The simulation results of average residence time of falling film flow with different viscous fluids were also consistent with the experimental results.This work provides the initial insights of how to evaluate and optimize the falling film flow system of polymer fluid.
基金project supported by the Science and Technology Department of Zhejiang Province (2005C13003).
文摘Objective To examine the effect of hydraulic residence time （HRT） on the performance and stability, to treat dilute wastewater at different operational temperatures in a carrier anaerobic baffled reactor （CABR）, and hence to gain a deeper insight into microbial responses to hydraulic shocks on the base of the relationships among macroscopic performance, catabolic intermediate, and microcosmic alternation. Methods COD, VFAs, and microbial activity were detected with constant feed strength （300 mg/L） at different HRTs （9-18 h） and temperatures （10℃-28℃） in a CABR. Results The removal efficiencies declined with the decreases of HRTs and temperatures. However, the COD removal load was still higher at short HRT than at long HRT. Devastating reactor performance happened at temperature of 10℃ and at HRT of 9 h. HRTs had effect on the VFAs in the reactor slightly both at high and low temperatures, but the reasons differed from each other. Microbial activity was sensitive to indicate changes of environmental and operational parameters in the reactor. Conclusion The CABR offers to certain extent an application to treat dilute wastewater under a hydraulic-shock at temperatures from 10℃to 28℃.
文摘The paper has analyzed decorative characteristics and architectural style of Leichang Former Residence which have been summarized as precise axial space sequence that can be divided into dragon gate, central room and drawing room. It has explained the spatial-temporal view of "the unity between heaven and human" and human's subjective ideological connotation in Leichang Former Residence. From the perspectives of the spiritual connotation of roof decorations, grading system of roofing tiles and manifestation form, it has deeply revealed the important expressive force and representativeness of roofs in architectural group, pointed out its aesthetic feature and spiritual restriction to architectures even human's behavior, and showed that the roof is the architectural factor directly manifesting "rituality" and "the unity between human and heaven" in Chinese traditional culture.
基金National Natural Science Foundation of China, No.40601015 No.40671031 National Key Technology R＆D Program, No.2007BAC03A 11
文摘Groundwater residence time is an important indicator of hydrological cycle and essential for water resources development and utilization. In this paper, groundwater residence time in non-flood season, flood season and water year has been determined from daily streamflow hydrograph of ten hydrological stations in Wudinghe River Basin located in the middle reaches of the Yellow River Basin. Results have showed that： baseflow recession constant in Wudinghe River Basin ranges from 0.72 to 0.94 with a larger recession rate in flood season than that in non-flood season. Spatially, the recession rate of baseflow in loess area is the biggest, but is the smallest in the sandy area. The half-residence time of groundwater varies from 1.8 to 45.5 days while overall residence time of groundwater is between 34 and 342 days in different sub-basins of the Wudinghe River Basin. The annual average overall residence time of groundwater decreases from 117 days in the upper reaches to 73 days in the lower reaches.
文摘Driven by the policy of "balancing urban and rural development", urbanization in China has been accelerated and agricultural population transferred to urban areas, which guarantees the improvement of life quality and living environment of rural and agricultural population. The urbanization has always been accompanied by national economic development and social progress, relocation and development of rural areas have become a social issue for a certain time. Therefore, it is imperative to explore a series of concrete, well-timed and practical measures for settling rural population, figure out proper modes, materials and methods for rural residence planning and construction under the new conditions, and provide relevant operation and theoretical support. Problems in mountainous rural areas of China were proposed as great population but limited land resources, backward construction techniques, and residences not valuing low carbon or environment protection. In view of these problems, construction techniques suitable for actual conditions of rural areas were explored, energy-saving building materials combined, the style of "dragon sucking water" for mountainous rural areas was proposed, design advantages and details of this architectural model were analyzed.
基金Project 50425414 supported by the National Outstanding Youth Science Foundation of China
文摘The cyclonic static micro-bubble column flotation (FCSMC) is an effective separation device for fine particle treatment. The high mineralization rate and short flotation time of this equipment can be attributed to its unique cyclonic force field. It also has been observed that the presence of a cyclonic force field leads to a lower bottom separation size limit and a reduction of unselective entrainment. The collection zone of the column is considered to consist of two parts,a column separation zone and a cyclonic zone. Total recovery of the collection zone was developed. For our study,we analyzed the particle movement in the cyclonic zone. Particle residence time equations for the cyclonic zone were de-rived by force analysis. Results obtained in this study provide a theoretical foundation for the design and scale-up of the FCSMC.
基金The National Key Basic Research Special Foundation of China under contract No.2013CB965101the Marine Science and Technology Foundation of the South China Sea Sub-administration,SOA,China under contract No.1624
文摘The importance of dissolved organic phosphorus(DOP) as a potential nutrient source for primary producers in marine systems has been recognized for up to eight decades, but currently, the understanding of the biogeochemistry of DOP is in its infancy. In the present study, monthly data between 2000 and 2014 were used to analyze the temporal and spatial distributions of DOP in the Mir Bay, the northern South China Sea. The DOP residence time(TDOP) was also investigated using a simple regression analysis in combination with chlorophyll a(Chl a) measurements while excess DOP(ΔDOP), produced by the biogeochemical processes of autotrophic production and heterotrophic removal, was determined using a two-component mixing mass-balance model in combination with salinity measurements. The results showed that the DOP concentration was(0.017±0.010) mg/L higher in the surface-water compared with the bottom-water and higher in the inner Tolo Harbour and waters adjacent to Shatoujiao compared with the main zone of the bay. Although seasonal changes and annual variability in the DOP were small, the surface DOP concentration was higher in the wet season(April–September)than in the dry season(October–March) due to the impacts of seaward discharges and atmospheric deposition into the bay. Measurement and regression results showed that the DOP release rate from phytoplankton production was about 1.83(gP)/(gChl a) and the TDOP was about 7 d, which implied that the DOP cycle in the bay was rapid. The ΔDOP was calculated from the model to be about 0.000 mg/L in the main zone of the bay and about 0.002 mg/L in the inner Tolo Harbour and waters adjacent to Shaotoujiao, suggesting that the autotrophic production of DOP was almost balanced by the heterotrophic removal in the main zone of the bay and dominated in the inner Tolo Harbour and waters adjacent to Shaotoujiao. In conclusion, the Mirs Bay is very productive and fairly heterotrophic.
基金Under the auspices of the Creative Group Foundation of the National Natural Science Foundation of China(50721006)the National Basic Research Program of China(2006CB403402-3)+1 种基金the National Water Resource and Environment Special Item(2008ZX07207-006-04)the Natural Science Foundation of Shanghai(10ZR1400300)
文摘As an important design factor for constructed wetlands,hydraulic retention time and its distribution will affect the treatment performance.Instantaneously injected sodium chloride tracers were used to obtain residence time distributions of the lab scale subsurface flow constructed wetland.Considering the presence of trailing and multiple peaks of the tracer breakthrough curve,the multi flow dispersion model(MFDM)was used to fit the experimental tracer breakthrough curves.According to the residual sum of squares and comparison between the experimental values and simulated values of the tracer concentration,MFDM could fit the residence time distribution(RTD)curve satisfactorily,the results of which also reflected the layered structure of wetland cells,thus to give reference for application of MFDM to the same kind of subsurface flow constructed wetlands.
基金Under the auspices of National Natural Science Foundation of China(No.42001132)MOE(Ministry of Education in China)Project of Humanities and Social Sciences(No.20YJC790009)Natural Science Basic Research Program of Shannxi,China(No.2020JQ-838)。
文摘Exploring long-term residence among the urban floating population is crucial to understanding urban growth in China,particularly since the 2008 financial crisis.By using China Migrants Dynamic Survey data for 2012–2014,China Labor-force Dynamics Survey data for 2014–2016,and macroscale urban matched data,we analyzed the spatial pattern of long-term residential behavior in China’s urban floating population in 2012–2016 and developed an urban spatial utility equilibrium model containing‘macro’urban factors and‘micro’individual and household factors to explain the pattern.The results first revealed that long-term residence is defined as≥6 yr for the urban floating population in China.Second,members of this population are more likely to be long-term residents of the megacities in the three urban agglomerations in eastern China as well as of small and medium-sized cities in western and northeastern China,whereas short-term residence is more likely in cities in central China and near the three urban agglomerations.Third,urban population density and housing prices,both have a significant U-shaped effect,are main factors affecting the spatial pattern of long-term residence.
基金Supported by the Research on the Mechanism and System of Guiding Farmers' Relatively Centralized Residence (0106002442003)Research Program of the Comprehensive Matching Reform Subject of Coordinating City and Village in 2009
文摘On the basis of expounding the status quo of rural residents' residence, the thesis notes that influenced by the weak foundation of rural economy, the characteristic of mountain landscape, smallholder consciousness, shortage of capital and other factors, the rural residents in Chongqing City mainly live scattered. In addition to opportunities of the expansion and drive of city, rural market development, rural resources development, rural industrial development, and rural ecological migration, the model of urban development promotion, the model of market development drive, the model of land development drive, the model of rural industry construction and the model of resettlement and reconstruction are advocated in order to guide the rural residents to adopt relative centralized residence. The suggestions concerning guiding rural residents' relative centralized residence are put forward as follows: firstly, act according to circumstances and conduct scientific planning and design; secondly, propagate extensively and activate famers' willingness; thirdly, first experiment and exert the exemplary guide; fourthly, perfect policy and guarantee farmers' benefit; fifthly, strengthen leadership and decrease the risk of centralized residence; sixthly, boost gradually and realize moderate centralized residence.
基金funded by the project of China Geological Survey(Grant No.DD20221677-2)the Central Public-Interest Scientific Institution Basal Research Fund(Grant No.JKYQN202307)。
文摘Geothermal resources are increasingly gaining attention as a competitive,clean energy source to address the energy crisis and mitigate climate change.The Wugongshan area,situated in the southeast coast geothermal belt of China,is a typical geothermal anomaly and contains abundant medium-and low-temperature geothermal resources.This study employed hydrogeochemical and isotopic techniques to explore the cyclic evolution of geothermal water in the western Wugongshan region,encompassing the recharge origin,water-rock interaction mechanisms,and residence time.The results show that the geothermal water in the western region of Wugongshan is weakly alkaline,with low enthalpy and mineralization levels.The hydrochemistry of geothermal waters is dominated by Na-HCO_(3)and Na-SO_(4),while the hydrochemistry types of cold springs are all Na-HCO_(3).The hydrochemistry types of surface waters and rain waters are NaHCO_(3)or Ca-HCO_(3).The δD and δ^(18)O values reveal that the geothermal waters are recharged by atmospheric precipitation at an altitude between 550.0 and 1218.6 m.Molar ratios of maj or solutes and isotopic compositions of^(87)Sr/^(86)Sr underscore the significant role of silicate weathering,dissolution,and cation exchange in controlling geothermal water chemistry.Additionally,geothermal waters experienced varying degrees of mixing with cold water during their ascent.Theδ^(13)C values suggest that the primary sources of carbon in the geothermal waters were biogenic and organic.Theδ^(34)S value suggests that the sulfates in geothermal water originate from sulfide minerals in the surrounding rock.Age dating using 3H and^(14)C isotopes suggests that geothermal waters have a residence time exceeding 1 kaBP and undergo a long-distance cycling process.
基金supported by the National Natural Science Foundation of China(Nos.41807219,41877192,U1906209,42072331)the National Key R&D Program of China(No.2017YFC0505304)the Fundamental Research Funds for Central Public Welfare Research Institutes(Nos.CKSF 2019170/TB,CKSF 2016029/TB)。
文摘How to identify the nested structure of a three-dimensional(3D)hierarchical groundwater flow system is always a difficult problem puzzling hydrogeologists due to the multiple scales and complexity of the 3D flow field.The main objective of this study was to develop a quantitative method to partition the nested groundwater flow system into different hierarchies in three dimensions.A 3D numerical model with topography derived from the real geomatic data in Jinan,China was implemented to simulate groundwater flow and residence time at the regional scale while the recharge rate,anisotropic permeability and hydrothermal effect being set as climatic and hydrogeological variables in the simulations.The simulated groundwater residence time distribution showed a favorable consistency with the spatial distribution of flow fields.The probability density function of residence time with discontinuous segments indicated the discrete nature of time domain between different flow hierarchies,and it was used to partition the hierarchical flow system into shallow/intermediate/deep flow compartments.The changes in the groundwater flow system can be quantitatively depicted by the climatic and hydrogeological variables.This study provides new insights and an efficient way to analyze groundwater circulation and evolution in three dimensions from the perspective of time domain.
