This paper aims to explore the integration of ideological and political education with specialized knowledge in the course of green building design.Through an analysis of the green building design course,combined with...This paper aims to explore the integration of ideological and political education with specialized knowledge in the course of green building design.Through an analysis of the green building design course,combined with the current social development background and the need for ecological and environmental protection,the study investigates how to effectively integrate ideological and political education elements into course instruction to enhance the comprehensive quality and green design capabilities of architecture students.The paper analyzes the content and characteristics of the green building design course and proposes an integration mechanism for ideological and political education in green building design teaching,aiming to cultivate architecture talents with green design concepts and good ideological and political qualities.展开更多
Owing to the complexity of the pipe-in-pipe (PIP) riser system in structure, load and restraint, many problems arise in the structural analysis of the system. This paper presents a new method for nonlinear static fini...Owing to the complexity of the pipe-in-pipe (PIP) riser system in structure, load and restraint, many problems arise in the structural analysis of the system. This paper presents a new method for nonlinear static finite element stress analysis of the PIP riser system. The finite element (FE) model of the PIP riser system is built via software AutoPIPE 6.1. According to the specialties of a variety of components in the PIP riser system, different elements are used so as to model the system accurately. Allowing for the complication in modeling the effects of seabed restraint, a technique based on the bilinear spring concept is developed to calculate the soil properties. Then, based on a pipeline project, the entire procedure of stress analysis is discussed in detail, including creation of an FE model, processing of input data and analysis of results. A wide range of loading schemes is investigated to ascertain that the stresses remain within the acceptable range of the pipe material strength. Finally, the effects of the location of flanges, the thermal expansion of submarine pipelines and the seabed restraint on stress distribution in the riser and expansion loop are studied, which are valuable for pipeline designers.展开更多
The large cylinder is a new-type structure that has been applied to harbor and offshore engineering. An analytic method of the relationship between loads and the structure displacement is developed based on the failur...The large cylinder is a new-type structure that has been applied to harbor and offshore engineering. An analytic method of the relationship between loads and the structure displacement is developed based on the failure mode of deep embedded large cylinder structures. It can be used to calculate directly the soil resistance and the ultimate bearing capacity of the structure under usage. A new criterion of the large cylinder structure, which discriminates the deep embedded cylinder from the shallow embedded cylinder, is defined. Model tests prove that the proposed method is feasible for the analysis of deep embedded large cylinder structures.展开更多
Thermogravimetric analysis and electrical resistivity were used to determine the hydration process of cement paste with rice husk ash(RHA)(0−15%)and water-cement ratio of 0.4 in this work.X-ray diffraction(XRD)method ...Thermogravimetric analysis and electrical resistivity were used to determine the hydration process of cement paste with rice husk ash(RHA)(0−15%)and water-cement ratio of 0.4 in this work.X-ray diffraction(XRD)method and scanning electron microscopy(SEM)were used to survey crystal composition and microstructures of specimens cured for 3 h,1 d,7 d and 28 d.Finally,electrical parameters(electrical resistance and AC impedance spectroscopy)of steel bars reinforced cement paste were investigated to study the effect of RHA on the corrosion resistance.Results showed that RHA could affect the cement hydration by hydration promotion and pozzolanic effect.The evaluation function for electrical resistivity and curing ages fitted well with linear increasing function.The addition of RHA higher than 5%demonstrated a decreasing role in the electrical resistivity of cement paste at earlier curing ages(3−7 d).Meanwhile,when at later curing ages(7−28 d)the result was the opposite.Moreover,RHA demonstrated positive effects on corrosion resistance of steel bars in cement paste.展开更多
To explore an environmentally friendly improvement measure for red clay,the function and mechanism of xanthan gum biopolymer and polypropylene fibers on the strength properties of red clay were investigated by unconfi...To explore an environmentally friendly improvement measure for red clay,the function and mechanism of xanthan gum biopolymer and polypropylene fibers on the strength properties of red clay were investigated by unconfined compressive strength and scanning electron microscopy tests.The test results demonstrated that the contents and curing ages of xanthan gum had significant influences on the unconfined compressive strength of red clay.Compared with untreated soil,1.5%xanthan gum content was the optimal ratio in which the strength increment was between 41.52 kPa and 64.73 kPa.On the other hand,the strength of xanthan gum-treated red clay increased,whereas the ductility decreased with the increase in curing ages,indicating that the xanthan gum-treated red clay started to gradually consolidate after 3 days of curing and stiffness significantly improved between 7 and 28 days of curing.The results also showed that the synergistic consolidation effects of the xanthan gum–polypropylene fibers could not only effectively enhance the strength of red clay but also reduce the brittle failure phenomenon.The strengths of soil treated with 2.0%xanthan gum-polypropylene fibers were 1.9–2.41 and 1.12–1.47 times than that of red clay and 1.5%xanthan gum-treated clay,respectively.The results of study provide the related methods and experiences for the field of ecological soil treatment.展开更多
To better study the behavior of confined concrete, this paper presents the basic hypothesis of uhimate equilibrium of confined concrete and the unified yield criteria of confining material. Based on the static equilib...To better study the behavior of confined concrete, this paper presents the basic hypothesis of uhimate equilibrium of confined concrete and the unified yield criteria of confining material. Based on the static equilibrium condition and yield criteria of components, a unified bearing capacity model of confined concrete column is proposed, and a simplified calculating equation of the model is also given. The model captures the character of confined concrete column. Effects of the confinement effect ratio, the lateral confinement ratio, unconfined concrete strength and the properties of confining material on the bearing capacity of confined concrete column are carefully considered. The model may be applicable to the calculation of bearing capacity of steel-confined concrete, concrete filled steel tube and FRP-confined concrete. The predictions of the model agree well with test data.展开更多
This study focuses on the workability and compressive strength of ceramsite self-compacting concrete with fine aggregate partially substituted by steel slag sand(CSLSCC)to prevent the pollution of steel slag in the en...This study focuses on the workability and compressive strength of ceramsite self-compacting concrete with fine aggregate partially substituted by steel slag sand(CSLSCC)to prevent the pollution of steel slag in the environment.The SF,J-ring,visual stability index,and sieve analysis tests are primarily employed in this research to investigate the workability of freshly mixed self-compacting concrete containing steel slag at various steel slag sand replacement rates.The experiment results indicate that CSLSCC with the 20%volume percentage of steel slag(VPS)performs better workability,higher strength,and higher specific strength.The 7-day compressive strength of CSLSCC with the 0.4 of the water-binder ratio(W/B),decreases with the increase of steel slag content,while the 28-day compressive strength increases significantly.The ceramsite self-compacting concrete with good comprehensive performance can be obtained when the substitution rate of steel slag sand for fine aggregate is less than 20%(volume percentage).展开更多
As wavelet basis in wavelet analysis is neither arbitrary nor unique,the same signal dealing with different wavelet bases will generate different results.Therefore,how to construct a wavelet basis suitable for the cha...As wavelet basis in wavelet analysis is neither arbitrary nor unique,the same signal dealing with different wavelet bases will generate different results.Therefore,how to construct a wavelet basis suitable for the characteristics of the analyzed signal and solve its algorithm and realization is a fundamental problem which perplexed many researchers.To solve these problems,in accordance with the basic features of the measured millisecond blast vibration signal,a new wavelet basis construction method based on the separation blast vibration signal is proposed,and the feasibility of this method is verified by comparing the practical effect of the newly constructed wavelet with other known wavelets in signal processing.展开更多
External confinement by fiber reinforced polymer (FRP) is an efficient technique to increase the bearing capacity and ductility of concrete. To better study the mechanical behavior of bidirectional FRP confined concre...External confinement by fiber reinforced polymer (FRP) is an efficient technique to increase the bearing capacity and ductility of concrete. To better study the mechanical behavior of bidirectional FRP confined concrete, the yield criterion of bidirectional FRP is presented based on the static equilibrium condition in this paper, and a model for calculating the bearing capacity of bidirectional FRP confined concrete is established. The model can capture the character of bidirectional FRP confined concrete. Effects of the confinement effect coefficient, the unconfined concrete strength and the material properties of FRP on bearing capacity are analyzed. Results show that each parameter has different effects on the bearing capacity of bidirectional FRP confined concrete.展开更多
The navigation software uses the positioning system to determine the traffic conditions of the road sections in advance,so as to predict the travel time of the road sections.However,in the case of traffic congestion,t...The navigation software uses the positioning system to determine the traffic conditions of the road sections in advance,so as to predict the travel time of the road sections.However,in the case of traffic congestion,the accuracy of its prediction time is low.After empirical analysis,this paper establishes a multi-factor synthesis by studying 7 factors:traffic flow,number of stops,traffic light duration,road network density,average speed,road area,and number of intersections the prediction function achieves the purpose of accurately predicting the transit time of congested road sections.The gray correlation coefficients of the seven factors obtained from the gray correlation analysis are:0.9827,0.9679,0.6747,0.8030,0.9445,0.8759,0.4328.The correlation coefficients of traffic volume,number of stops,average speed,and road congestion delay time were all about 95%,which were the main influencing factors of the study.The prediction needs to be based on functions.This paper fits the main influencing factors to the delay time of congested roads.It is found that the delay time varies parabolically with the traffic flow and the number of stops,and linearly with the average speed.Because the three impact factors have different weights on the delay time of congested roads,demand takes the weight of each factor.Therefore,the gray correlation coefficients occupied by the main influencing factors are normalized to obtain the weights of three of 0.340,0.334,and 0.326.The weighted fitting function is subjected to nonlinear summation processing to obtain a multi-factor comprehensive prediction function.By comparing the original data with the fitting data and calculating the accuracy of the fitting function,it is found that the accuracy of each fitting function is close to 0,the residual error,the relative error is small,and the accuracy is high.展开更多
Based on a comprehensive investigation of the employment status of architectural design graduates at a certain university,this paper analyzes the correctness of the talent development direction of architectural design...Based on a comprehensive investigation of the employment status of architectural design graduates at a certain university,this paper analyzes the correctness of the talent development direction of architectural design in hopes of pro-viding a valuable reference for further teaching reform and strengthening school-enterprise collaboration.The research re-sults show that architectural design is the main choice of graduates,accounting for as high as 63%,and traditional architec-tural design skills continue to be in demand in the market.Employment in fields such as interior design,BIM design,and green architecture is also included.The distribution of job positions for graduates is mainly in the areas of scheme design assistants and construction drawing design,requiring software operation,communication,scheme design,and construction drawing skills.This paper also proposes talent development measures such as optimizing the curriculum,strengthening faculty construction,and deepening school-enterprise collaboration,in order to improve the quality of talent development and the competitiveness of graduates.展开更多
Green campus design has become an essential strategy to enhance campus life and learning.However,noise pol-lution remains a troubling aspect that impacts teaching and learning processes,even causing harm to the health...Green campus design has become an essential strategy to enhance campus life and learning.However,noise pol-lution remains a troubling aspect that impacts teaching and learning processes,even causing harm to the health of students and teachers.Therefore,acoustic environment quality design is crucial.This article focuses on the expansion project of a school campus in Shenzhen.We simulated and analyzed the outdoor noise environment separately for the proposed teach-ing building,as well as the existing buildings like the dining hall,teaching building,and laboratory building.The results showed that the proposed teaching building was mainly affected by surrounding noise,with the worst outdoor noise being in classrooms adjacent to the teaching building in the south and the basketball court at the west of the classroom,with maximum noise values reaching 73 dB and 66 dB,respectively.In the future,these rooms should be renovated to achieve an excellent indoor soundproof environment.展开更多
A good sound environment is essential in creating a harmonious and peaceful campus,improving students’learning outcomes,promoting physical and mental health,and creating a green and healthy campus.This study investig...A good sound environment is essential in creating a harmonious and peaceful campus,improving students’learning outcomes,promoting physical and mental health,and creating a green and healthy campus.This study investigated the impact of new buildings on existing ones by optimizing the spacing between new buildings and the sound insulation structure of building enclosures.The results indicated that building 4 was affected by the noise from new building 1 and its surroundings,with a maximum outdoor daytime noise level reaching 69 dB,and the indoor background noise level in the least favorable classroom was 43.73 dB,less than 45 dB,which was within the acceptable range.It is recommended that the sound insulation design be improved in the planning of new teaching buildings.Besides,the surrounding traffic conditions should be improved,and the usage time of sports facilities should be scheduled appropriately to prevent the noise from sporting activities from affecting the classroom activities.The findings of this study provide valuable references for future architectural acoustics design and campus planning,contributing to the creation of peaceful and comfortable campus environments.展开更多
There is little empirical evidence in the literature about the indoor environmental quality performance of residential buildings in general and of social housing in particular. To address this problem, this study used...There is little empirical evidence in the literature about the indoor environmental quality performance of residential buildings in general and of social housing in particular. To address this problem, this study used a mixed-method approach to evaluate the indoor environmental quality performance of 17 green low-income single attached family houses in Brandon, Manitoba, Canada. Questionnaires were administered to occupants to assess their snapshot and long-term satisfaction with the indoor environment. In addition, snapshot measurements were carried out to evaluate the indoor environmental quality factors of thermal comfort, indoor air quality, lighting and acoustics. Occupants’ snapshot satisfaction was categorized into two groups (i.e. satisfied/comfortable or dissatisfied/uncomfortable) and compared with snapshot measurements. The results showed the measured IEQ parameters were well below recommended threshold levels. Further, occupants with higher snapshot satisfaction were generally exposed to relatively lower levels of indoor pollutants. A statistically significant difference was found in PM10 level only between the snapshot satisfied and snapshot dissatisfied groups of occupants. Apparent sound transmission classes were below the standard reference value of 50, suggesting potential problems in noise attenuation within different spaces in each apartment and between apartments. The findings of this study could help governments implement green shadowing for public-housing and also renovate existing houses using the same principles.展开更多
It is common in industrial construction projects for data to be collected and discarded without being analyzed to extract useful knowledge. A proposed integrated methodology based on a five-step Knowledge Discovery in...It is common in industrial construction projects for data to be collected and discarded without being analyzed to extract useful knowledge. A proposed integrated methodology based on a five-step Knowledge Discovery in Data (KDD) model was developed to address this issue. The framework transfers existing multidimensional historical data from completed projects into useful knowledge for future projects. The model starts by understanding the problem domain, industrial construction projects. The second step is analyzing the problem data and its multiple dimensions. The target dataset is the labour resources data generated while managing industrial construction projects. The next step is developing the data collection model and prototype data ware-house. The data warehouse stores collected data in a ready-for-mining format and produces dynamic On Line Analytical Processing (OLAP) reports and graphs. Data was collected from a large western-Canadian structural steel fabricator to prove the applicability of the developed methodology. The proposed framework was applied to three different case studies to validate the applicability of the developed framework to real projects data.展开更多
Accurate simulations of planetary boundary layer(PBL)winds in urban areas require combining meteorological knowledge and fine-grained geometrical information.Computational fluid dynamics(CFD)is widely used to assess p...Accurate simulations of planetary boundary layer(PBL)winds in urban areas require combining meteorological knowledge and fine-grained geometrical information.Computational fluid dynamics(CFD)is widely used to assess pedestrian wind comfort and wind disasters in planning resilient cities.However,the CFD-predicted PBL is highly affected by the inflow boundaries.Wind profiles under extreme weather conditions,such as tropical cyclones,can hardly be determined,and associated uniform logarithmic or power law expressions have not been obtained.In this study,urban wind flow over mountainous terrain was simulated using a one-way nested simulation approach between mesoscale and microscale models.The inflow wind speed,turbulence scalars,and potential temperature in the CFD code are sustained by the numerical weather prediction(NWP)model.Methodologies considering typhoon weather conditions were examined to improve the numerical accuracy in determining mesoscale typhoon structures and pedestrian-level wind conditions.The numerical errors were quantified in mesoscale and microscale formulations.A new tendency assimilation was proposed by incorporating local-scale observations into the CFD domain.This approach entailed empirical mode decomposition to quantify the mean wind speed differences between the observations and NWP results,which were then extrapolated to NWP-CFD nested interfaces via multiplication by the spatial correlation coefficient.The numerical performance was validated against both on-site observations for meteorological purposes and wind profiles retrieved from the experimental LiDAR of the landfalling typhoon Haima.The simulated wind field exhibited an increased accuracy in the local urban area.More specifically,the index of agreement in wind speeds was improved from 0.28 to 0.72,and the mean absolute errors were reduced from 5.46 m/s to 1.89 m/s.展开更多
Photocatalytic water splitting(PWS)provides an optimal approach for the sustainable production of green hydrogen.NH_(2)-modified covalent triazine frameworks(CTFs-NH_(2))hold potential in PWS due to robust light uptak...Photocatalytic water splitting(PWS)provides an optimal approach for the sustainable production of green hydrogen.NH_(2)-modified covalent triazine frameworks(CTFs-NH_(2))hold potential in PWS due to robust light uptake,optimal charge separation,and considerable redox potential.However,the high surface reaction barriers hinder the efficiency of PWS owing to the conversion difficulty of intermediate products.Modulating the Lewis basicity of NH_(2)on CTFs offers a feasible route for addressing this challenge.In this work,electron-donating ethyl(C_(2)F_(5))and electronwithdrawing 5-fluoroethyl groups(C_(2)F_(5))are introduced at the para position of amine groups,producing C_(2)F_(5)-CTF-NH_(2)and C_(2)F_(5)-CTF-NH_(2),to adjust the Lewis basicity of CTF-NH_(2).Through DFT calculations,the optical properties,excited states,electronic structures,dipole moments,and surface reaction processes of the CTF-NH_(2),C_(2)F_(5)-CTF-NH_(2)and C_(2)F_(5)-CTF-NH_(2)are simulated.The results indicate that the electron-withdrawing C_(2)F_(5)group can decrease the electron density and Lewis basicity on NH_(2),thereby lowering the energy barriers for hydrogen and oxygen evolution reactions,effectively ameliorating the PWS efficiency of CTF-NH_(2).This work unveils an innovative approach for donor-acceptor-regulated CTFs for the application of PWS.展开更多
Based on the free vibration test method for extracting flutter derivatives,an experiment on flutter stability of a long-span bridge under simultaneous actions of wind and rain was carried out in a wind tunnel.A separa...Based on the free vibration test method for extracting flutter derivatives,an experiment on flutter stability of a long-span bridge under simultaneous actions of wind and rain was carried out in a wind tunnel.A separated twin-box girder section model was employed as the specimen.The flutter derivatives and critical flutter wind speed of this girder subject to both wind and rain(with various rainfall intensities,wind speeds and attack angles)were obtained,then the flutter stability of the bridge influenced by rainfall was analyzed.Experimental results showed that the flutter derivatives of this bridge depend on the angles of attack of wind flow in the wind and rain fields.Also,rainfall has great effect on three flutter derivatives(H2*,H4* and A4*)and has less effect on other three flutter derivatives(H1*,H3* and A3*).With the increasing rainfall density,the critical flutter velocity first increases and then decreases.Low density of rainfall has the effect of increasing mass,stiffness and damping on bridge decks,and higher density of rainfall has the effect of random inhomogeneous impact on bridge decks.展开更多
基金Guangdong Higher Vocational Education Teaching Reform Research and Practice Project(2023JG338)Shenzhen Polytechnic University 2024 Demonstration Course of Ideological and Political Education in Curriculum and First-Class Courses(Green Building Design)+5 种基金Education and Teaching Reform Project of Guangdong Higher Vocational Civil Engineering and Water Conservancy Education and Teaching Committee(2023TJSL21)Guangdong Provincial Philosophy and Social Sciences Planning Project,“Inheritance and Innovation of Traditional Lingnan Residences Design Features in the Construction of New Countryside”Shenzhen Polytechnic University Project,“Research on the Inheritance and Innovation Path of the Design Aesthetics of Lingnan Traditional Residential Houses in the Construction of New Rural Areas”2023 Guangdong Higher Vocational Education Demonstration Industrial College:Shenzhen Polytechnic University&Tianjian Construction Engineering College ProjectOpen Project of Key Laboratory of Huizhou Architecture in Anhui Province(HPJZ-2023-05)Research Projects of the Department of Education of Guangdong Province(2023WCXTD037)。
文摘This paper aims to explore the integration of ideological and political education with specialized knowledge in the course of green building design.Through an analysis of the green building design course,combined with the current social development background and the need for ecological and environmental protection,the study investigates how to effectively integrate ideological and political education elements into course instruction to enhance the comprehensive quality and green design capabilities of architecture students.The paper analyzes the content and characteristics of the green building design course and proposes an integration mechanism for ideological and political education in green building design teaching,aiming to cultivate architecture talents with green design concepts and good ideological and political qualities.
文摘Owing to the complexity of the pipe-in-pipe (PIP) riser system in structure, load and restraint, many problems arise in the structural analysis of the system. This paper presents a new method for nonlinear static finite element stress analysis of the PIP riser system. The finite element (FE) model of the PIP riser system is built via software AutoPIPE 6.1. According to the specialties of a variety of components in the PIP riser system, different elements are used so as to model the system accurately. Allowing for the complication in modeling the effects of seabed restraint, a technique based on the bilinear spring concept is developed to calculate the soil properties. Then, based on a pipeline project, the entire procedure of stress analysis is discussed in detail, including creation of an FE model, processing of input data and analysis of results. A wide range of loading schemes is investigated to ascertain that the stresses remain within the acceptable range of the pipe material strength. Finally, the effects of the location of flanges, the thermal expansion of submarine pipelines and the seabed restraint on stress distribution in the riser and expansion loop are studied, which are valuable for pipeline designers.
文摘The large cylinder is a new-type structure that has been applied to harbor and offshore engineering. An analytic method of the relationship between loads and the structure displacement is developed based on the failure mode of deep embedded large cylinder structures. It can be used to calculate directly the soil resistance and the ultimate bearing capacity of the structure under usage. A new criterion of the large cylinder structure, which discriminates the deep embedded cylinder from the shallow embedded cylinder, is defined. Model tests prove that the proposed method is feasible for the analysis of deep embedded large cylinder structures.
基金Projects(51808300,51778302)supported by the National Natural Science Foundation of ChinaProject supported by the K.C.Wong Magna Fund in Ningbo University,China。
文摘Thermogravimetric analysis and electrical resistivity were used to determine the hydration process of cement paste with rice husk ash(RHA)(0−15%)and water-cement ratio of 0.4 in this work.X-ray diffraction(XRD)method and scanning electron microscopy(SEM)were used to survey crystal composition and microstructures of specimens cured for 3 h,1 d,7 d and 28 d.Finally,electrical parameters(electrical resistance and AC impedance spectroscopy)of steel bars reinforced cement paste were investigated to study the effect of RHA on the corrosion resistance.Results showed that RHA could affect the cement hydration by hydration promotion and pozzolanic effect.The evaluation function for electrical resistivity and curing ages fitted well with linear increasing function.The addition of RHA higher than 5%demonstrated a decreasing role in the electrical resistivity of cement paste at earlier curing ages(3−7 d).Meanwhile,when at later curing ages(7−28 d)the result was the opposite.Moreover,RHA demonstrated positive effects on corrosion resistance of steel bars in cement paste.
基金This study was supported by the State Key Laboratory Project of China(Grant No.KF2020-12)the Yunnan Education Department Project of China(Grant Nos.2020Y0175 and 2020J0240).
文摘To explore an environmentally friendly improvement measure for red clay,the function and mechanism of xanthan gum biopolymer and polypropylene fibers on the strength properties of red clay were investigated by unconfined compressive strength and scanning electron microscopy tests.The test results demonstrated that the contents and curing ages of xanthan gum had significant influences on the unconfined compressive strength of red clay.Compared with untreated soil,1.5%xanthan gum content was the optimal ratio in which the strength increment was between 41.52 kPa and 64.73 kPa.On the other hand,the strength of xanthan gum-treated red clay increased,whereas the ductility decreased with the increase in curing ages,indicating that the xanthan gum-treated red clay started to gradually consolidate after 3 days of curing and stiffness significantly improved between 7 and 28 days of curing.The results also showed that the synergistic consolidation effects of the xanthan gum–polypropylene fibers could not only effectively enhance the strength of red clay but also reduce the brittle failure phenomenon.The strengths of soil treated with 2.0%xanthan gum-polypropylene fibers were 1.9–2.41 and 1.12–1.47 times than that of red clay and 1.5%xanthan gum-treated clay,respectively.The results of study provide the related methods and experiences for the field of ecological soil treatment.
基金Sponsored by the National Natural Science Foundation of China(Grant No.50538060)the Excellent Young College Teacher Foundation of Anhui Prov-ince(Grant No.2009SQRZ081)
文摘To better study the behavior of confined concrete, this paper presents the basic hypothesis of uhimate equilibrium of confined concrete and the unified yield criteria of confining material. Based on the static equilibrium condition and yield criteria of components, a unified bearing capacity model of confined concrete column is proposed, and a simplified calculating equation of the model is also given. The model captures the character of confined concrete column. Effects of the confinement effect ratio, the lateral confinement ratio, unconfined concrete strength and the properties of confining material on the bearing capacity of confined concrete column are carefully considered. The model may be applicable to the calculation of bearing capacity of steel-confined concrete, concrete filled steel tube and FRP-confined concrete. The predictions of the model agree well with test data.
基金supported by the National Key Research and Development Program of China(No.2021YFB3802005)the National Natural Science Foundation of China(Grant No.51978002)+1 种基金the Natural Science Foundation for the Higher Education Institutions in Anhui Province of China(Grant No.KJ2020A0845)the Housing and Urban-Rural Construction Science and Technology Plan in Anhui Province of China(Grant No.2021-YF69).
文摘This study focuses on the workability and compressive strength of ceramsite self-compacting concrete with fine aggregate partially substituted by steel slag sand(CSLSCC)to prevent the pollution of steel slag in the environment.The SF,J-ring,visual stability index,and sieve analysis tests are primarily employed in this research to investigate the workability of freshly mixed self-compacting concrete containing steel slag at various steel slag sand replacement rates.The experiment results indicate that CSLSCC with the 20%volume percentage of steel slag(VPS)performs better workability,higher strength,and higher specific strength.The 7-day compressive strength of CSLSCC with the 0.4 of the water-binder ratio(W/B),decreases with the increase of steel slag content,while the 28-day compressive strength increases significantly.The ceramsite self-compacting concrete with good comprehensive performance can be obtained when the substitution rate of steel slag sand for fine aggregate is less than 20%(volume percentage).
基金Projects(51078043,51278071,51308072)supported by the National Natural Science Foundation of China
文摘As wavelet basis in wavelet analysis is neither arbitrary nor unique,the same signal dealing with different wavelet bases will generate different results.Therefore,how to construct a wavelet basis suitable for the characteristics of the analyzed signal and solve its algorithm and realization is a fundamental problem which perplexed many researchers.To solve these problems,in accordance with the basic features of the measured millisecond blast vibration signal,a new wavelet basis construction method based on the separation blast vibration signal is proposed,and the feasibility of this method is verified by comparing the practical effect of the newly constructed wavelet with other known wavelets in signal processing.
基金Sponsored by the National Natural Science Foundation of China(Grant No.50538060)the Excellent Young College Teacher Foundation of Anhui Province(Grant No.2009SQRZ081)
文摘External confinement by fiber reinforced polymer (FRP) is an efficient technique to increase the bearing capacity and ductility of concrete. To better study the mechanical behavior of bidirectional FRP confined concrete, the yield criterion of bidirectional FRP is presented based on the static equilibrium condition in this paper, and a model for calculating the bearing capacity of bidirectional FRP confined concrete is established. The model can capture the character of bidirectional FRP confined concrete. Effects of the confinement effect coefficient, the unconfined concrete strength and the material properties of FRP on bearing capacity are analyzed. Results show that each parameter has different effects on the bearing capacity of bidirectional FRP confined concrete.
文摘The navigation software uses the positioning system to determine the traffic conditions of the road sections in advance,so as to predict the travel time of the road sections.However,in the case of traffic congestion,the accuracy of its prediction time is low.After empirical analysis,this paper establishes a multi-factor synthesis by studying 7 factors:traffic flow,number of stops,traffic light duration,road network density,average speed,road area,and number of intersections the prediction function achieves the purpose of accurately predicting the transit time of congested road sections.The gray correlation coefficients of the seven factors obtained from the gray correlation analysis are:0.9827,0.9679,0.6747,0.8030,0.9445,0.8759,0.4328.The correlation coefficients of traffic volume,number of stops,average speed,and road congestion delay time were all about 95%,which were the main influencing factors of the study.The prediction needs to be based on functions.This paper fits the main influencing factors to the delay time of congested roads.It is found that the delay time varies parabolically with the traffic flow and the number of stops,and linearly with the average speed.Because the three impact factors have different weights on the delay time of congested roads,demand takes the weight of each factor.Therefore,the gray correlation coefficients occupied by the main influencing factors are normalized to obtain the weights of three of 0.340,0.334,and 0.326.The weighted fitting function is subjected to nonlinear summation processing to obtain a multi-factor comprehensive prediction function.By comparing the original data with the fitting data and calculating the accuracy of the fitting function,it is found that the accuracy of each fitting function is close to 0,the residual error,the relative error is small,and the accuracy is high.
基金Education Research and Reform Projects of Shenzhen Polytechnic University,China(Project No.7022310092)2022 Green Building Design Golden Course Construction Project of Shenzhen Polytechnic University,China+3 种基金2023 Guangdong Provincial Education and Teaching Reform Research and Practice Project,China2021 College Student Innovation Project of Shenzhen Polytechnic University,China(Project No.P-20210607-39632)2023 Education and Teaching Reform Project of the Higher Vocational Civil Engineering and Water Resources Instruction Committee of Guangdong Province,China(Project No.2023TJSL21)The Class II Brand Specialty Construction of the Guangdong Province,China(Project No.9004-02200202)。
文摘Based on a comprehensive investigation of the employment status of architectural design graduates at a certain university,this paper analyzes the correctness of the talent development direction of architectural design in hopes of pro-viding a valuable reference for further teaching reform and strengthening school-enterprise collaboration.The research re-sults show that architectural design is the main choice of graduates,accounting for as high as 63%,and traditional architec-tural design skills continue to be in demand in the market.Employment in fields such as interior design,BIM design,and green architecture is also included.The distribution of job positions for graduates is mainly in the areas of scheme design assistants and construction drawing design,requiring software operation,communication,scheme design,and construction drawing skills.This paper also proposes talent development measures such as optimizing the curriculum,strengthening faculty construction,and deepening school-enterprise collaboration,in order to improve the quality of talent development and the competitiveness of graduates.
基金Education Research and Reform Projects of Shenzhen Polytechnic University,China(Project No.7022310092)2022 Green Building Design Golden Course Construction Project of Shenzhen Polytechnic University,China+3 种基金2023 Guangdong Provincial Education and Teaching Reform Research and Practice Project,China2021 College Student Innovation Project of Shenzhen Polytechnic University,China(Project No.P-20210607-39632)2023 Education and Teaching Reform Project of the Higher Vocational Civil Engineering and Water Resources Instruction Committee of Guangdong Province,China(Project No.2023TJSL21)University Students’Science and Technology Innovation Cultivation Fund Project of Guangdong Province(Project No.pdjh2021b0896)。
文摘Green campus design has become an essential strategy to enhance campus life and learning.However,noise pol-lution remains a troubling aspect that impacts teaching and learning processes,even causing harm to the health of students and teachers.Therefore,acoustic environment quality design is crucial.This article focuses on the expansion project of a school campus in Shenzhen.We simulated and analyzed the outdoor noise environment separately for the proposed teach-ing building,as well as the existing buildings like the dining hall,teaching building,and laboratory building.The results showed that the proposed teaching building was mainly affected by surrounding noise,with the worst outdoor noise being in classrooms adjacent to the teaching building in the south and the basketball court at the west of the classroom,with maximum noise values reaching 73 dB and 66 dB,respectively.In the future,these rooms should be renovated to achieve an excellent indoor soundproof environment.
基金Education Research and Reform Projects of Shenzhen Polytechnic University,China(Project No.7022310092)2022 Green Building Design Golden Course Construction Project of Shenzhen Polytechnic University,China+3 种基金2023 Guangdong Provincial Education and Teaching Reform Research and Practice Project,China2021 College Student Innovation Project of Shenzhen Polytechnic University,China(Project No.P-20210607-39632)2023 Education and Teaching Reform Project of the Higher Vocational Civil Engineering and Water Resources Instruction Committee of Guangdong Province,China(Project No.2023TJSL21)The Class II Brand Specialty Construction of the Guangdong Province,China(Project No.9004-02200202)。
文摘A good sound environment is essential in creating a harmonious and peaceful campus,improving students’learning outcomes,promoting physical and mental health,and creating a green and healthy campus.This study investigated the impact of new buildings on existing ones by optimizing the spacing between new buildings and the sound insulation structure of building enclosures.The results indicated that building 4 was affected by the noise from new building 1 and its surroundings,with a maximum outdoor daytime noise level reaching 69 dB,and the indoor background noise level in the least favorable classroom was 43.73 dB,less than 45 dB,which was within the acceptable range.It is recommended that the sound insulation design be improved in the planning of new teaching buildings.Besides,the surrounding traffic conditions should be improved,and the usage time of sports facilities should be scheduled appropriately to prevent the noise from sporting activities from affecting the classroom activities.The findings of this study provide valuable references for future architectural acoustics design and campus planning,contributing to the creation of peaceful and comfortable campus environments.
文摘There is little empirical evidence in the literature about the indoor environmental quality performance of residential buildings in general and of social housing in particular. To address this problem, this study used a mixed-method approach to evaluate the indoor environmental quality performance of 17 green low-income single attached family houses in Brandon, Manitoba, Canada. Questionnaires were administered to occupants to assess their snapshot and long-term satisfaction with the indoor environment. In addition, snapshot measurements were carried out to evaluate the indoor environmental quality factors of thermal comfort, indoor air quality, lighting and acoustics. Occupants’ snapshot satisfaction was categorized into two groups (i.e. satisfied/comfortable or dissatisfied/uncomfortable) and compared with snapshot measurements. The results showed the measured IEQ parameters were well below recommended threshold levels. Further, occupants with higher snapshot satisfaction were generally exposed to relatively lower levels of indoor pollutants. A statistically significant difference was found in PM10 level only between the snapshot satisfied and snapshot dissatisfied groups of occupants. Apparent sound transmission classes were below the standard reference value of 50, suggesting potential problems in noise attenuation within different spaces in each apartment and between apartments. The findings of this study could help governments implement green shadowing for public-housing and also renovate existing houses using the same principles.
文摘It is common in industrial construction projects for data to be collected and discarded without being analyzed to extract useful knowledge. A proposed integrated methodology based on a five-step Knowledge Discovery in Data (KDD) model was developed to address this issue. The framework transfers existing multidimensional historical data from completed projects into useful knowledge for future projects. The model starts by understanding the problem domain, industrial construction projects. The second step is analyzing the problem data and its multiple dimensions. The target dataset is the labour resources data generated while managing industrial construction projects. The next step is developing the data collection model and prototype data ware-house. The data warehouse stores collected data in a ready-for-mining format and produces dynamic On Line Analytical Processing (OLAP) reports and graphs. Data was collected from a large western-Canadian structural steel fabricator to prove the applicability of the developed methodology. The proposed framework was applied to three different case studies to validate the applicability of the developed framework to real projects data.
基金This study was supported by the National Natural Science Foundation of China(No:51778200)Shenzhen Basic Research Program(No:JCYJ20190806145216643).
文摘Accurate simulations of planetary boundary layer(PBL)winds in urban areas require combining meteorological knowledge and fine-grained geometrical information.Computational fluid dynamics(CFD)is widely used to assess pedestrian wind comfort and wind disasters in planning resilient cities.However,the CFD-predicted PBL is highly affected by the inflow boundaries.Wind profiles under extreme weather conditions,such as tropical cyclones,can hardly be determined,and associated uniform logarithmic or power law expressions have not been obtained.In this study,urban wind flow over mountainous terrain was simulated using a one-way nested simulation approach between mesoscale and microscale models.The inflow wind speed,turbulence scalars,and potential temperature in the CFD code are sustained by the numerical weather prediction(NWP)model.Methodologies considering typhoon weather conditions were examined to improve the numerical accuracy in determining mesoscale typhoon structures and pedestrian-level wind conditions.The numerical errors were quantified in mesoscale and microscale formulations.A new tendency assimilation was proposed by incorporating local-scale observations into the CFD domain.This approach entailed empirical mode decomposition to quantify the mean wind speed differences between the observations and NWP results,which were then extrapolated to NWP-CFD nested interfaces via multiplication by the spatial correlation coefficient.The numerical performance was validated against both on-site observations for meteorological purposes and wind profiles retrieved from the experimental LiDAR of the landfalling typhoon Haima.The simulated wind field exhibited an increased accuracy in the local urban area.More specifically,the index of agreement in wind speeds was improved from 0.28 to 0.72,and the mean absolute errors were reduced from 5.46 m/s to 1.89 m/s.
文摘Photocatalytic water splitting(PWS)provides an optimal approach for the sustainable production of green hydrogen.NH_(2)-modified covalent triazine frameworks(CTFs-NH_(2))hold potential in PWS due to robust light uptake,optimal charge separation,and considerable redox potential.However,the high surface reaction barriers hinder the efficiency of PWS owing to the conversion difficulty of intermediate products.Modulating the Lewis basicity of NH_(2)on CTFs offers a feasible route for addressing this challenge.In this work,electron-donating ethyl(C_(2)F_(5))and electronwithdrawing 5-fluoroethyl groups(C_(2)F_(5))are introduced at the para position of amine groups,producing C_(2)F_(5)-CTF-NH_(2)and C_(2)F_(5)-CTF-NH_(2),to adjust the Lewis basicity of CTF-NH_(2).Through DFT calculations,the optical properties,excited states,electronic structures,dipole moments,and surface reaction processes of the CTF-NH_(2),C_(2)F_(5)-CTF-NH_(2)and C_(2)F_(5)-CTF-NH_(2)are simulated.The results indicate that the electron-withdrawing C_(2)F_(5)group can decrease the electron density and Lewis basicity on NH_(2),thereby lowering the energy barriers for hydrogen and oxygen evolution reactions,effectively ameliorating the PWS efficiency of CTF-NH_(2).This work unveils an innovative approach for donor-acceptor-regulated CTFs for the application of PWS.
基金supported by the Key Program of the Major Research Plan of the National Natural Science Foundation of China (Grant No.90815022)the National Natural Science Foundation of China (Grant No. 50908069)
文摘Based on the free vibration test method for extracting flutter derivatives,an experiment on flutter stability of a long-span bridge under simultaneous actions of wind and rain was carried out in a wind tunnel.A separated twin-box girder section model was employed as the specimen.The flutter derivatives and critical flutter wind speed of this girder subject to both wind and rain(with various rainfall intensities,wind speeds and attack angles)were obtained,then the flutter stability of the bridge influenced by rainfall was analyzed.Experimental results showed that the flutter derivatives of this bridge depend on the angles of attack of wind flow in the wind and rain fields.Also,rainfall has great effect on three flutter derivatives(H2*,H4* and A4*)and has less effect on other three flutter derivatives(H1*,H3* and A3*).With the increasing rainfall density,the critical flutter velocity first increases and then decreases.Low density of rainfall has the effect of increasing mass,stiffness and damping on bridge decks,and higher density of rainfall has the effect of random inhomogeneous impact on bridge decks.