A novel three-dimensional（3D） supramolecular architecture, {[Nd（OH-BDC）（OH-HBDC）（H2O）2]·2HaO）n（1） （OH-H2BDC=5-hydroxyisophthalic acid）, which was formed through hydrogen bonds and π-π stacking betw...A novel three-dimensional（3D） supramolecular architecture, {[Nd（OH-BDC）（OH-HBDC）（H2O）2]·2HaO）n（1） （OH-H2BDC=5-hydroxyisophthalic acid）, which was formed through hydrogen bonds and π-π stacking between two-dimensional（2D） layers, was hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Windmill building blocks, which consist of two nine-coordinated metal centers and four OH-H2BDC groups are connected through two carboxyl groups, to lead to a one-dimensional infinite inorganic chain（… M--O--C--O--M…） along the [100] direction. An observed intense blue luminescence with an emission band peaked at 390 nm for compound 1 may results from ligand-to-metal charge transfer（LMCT）. Variable-temperature magnetic susceptibility of compound 1 was investigated and the value was deviated from the Curie-Weiss law.展开更多
To improve the performance of an active mass damper control system,the controller should be designed based on a reduced-order model. An improved method based on balanced truncation method was proposed to reduce the di...To improve the performance of an active mass damper control system,the controller should be designed based on a reduced-order model. An improved method based on balanced truncation method was proposed to reduce the dimension of high-rise buildings,and was compared with other widely used reduction methods by using a framework with ten floors. This optimized method has improvement of reduction process and choice of the order. Based on the reduced-order model obtained by the improved method and pole-assignment algorithm,a controller was designed. Finally,a comparative analysis of structural responses,transfer functions,and poles was conducted on an actual high-rise building. The results show the effectiveness of the improved method.展开更多
The publication of ISO 15686-5 is significant for studies related to the life-cycle costs of buildings. Among the many economic evaluation methods, the NPV method is recommended for use by this standard. This stu...The publication of ISO 15686-5 is significant for studies related to the life-cycle costs of buildings. Among the many economic evaluation methods, the NPV method is recommended for use by this standard. This study explains the concept and method of PV, and then provides an explanation of the concept and method of NPV, and points out the limitations in the practical application of the method.展开更多
The characteristics of body build of middle - and old -aged women and its rule of variations as well as the basic sizes of various parts are discussed. All these are based on the body measurements of this age group, a...The characteristics of body build of middle - and old -aged women and its rule of variations as well as the basic sizes of various parts are discussed. All these are based on the body measurements of this age group, and also on the statistical studies of the measurement data. By setting the regression equation, the calculating formulae of various control parts are obtained, thus establishing the prototype of this age group for women.展开更多
The importance of good site progress records in quality assurance; tracking project progress; preparing, analyzing and resolving claims; and placing responsibilities in the event of dispute in building contracts is wi...The importance of good site progress records in quality assurance; tracking project progress; preparing, analyzing and resolving claims; and placing responsibilities in the event of dispute in building contracts is widely recognized. This study engaged Public Building Supervisors in the assessment of site progress record keeping practices in Abuja. A simple structured questionnaire （which mainly assessed the nature and importance of records kept, reasons for keeping them; level of satisfaction with the current approach, challenges and practical ways of improving the practice） was administrated to a hundred of the supervisors, out of which seventy one was properly completed and returned. The results show that all five site progress documents （minutes of progress meetings, day-work sheets, photographs, weekly site records and personal site diaries） found in literature, are in use in Abuja, and have at least a high importance rating （i.e., relative importance index, 0.6 〈 RII 〈 0.8）. Prominent among the reasons for keeping the records are： control of ongoing work （R11 = 0.83） data for estimating future works and terms of contract requirement （each with RII = 0.823）. Though the present record keeping practices were largely assessed satisfactory, 95% of the Supervisors still yearned for improvement. The challenges to the current practice are consistent with those identified in literature and are： continuity consistency, legibility and accountability; in descending order of frequency of occurrence. Computerization, regular inspection of progress documents by assigned supervisors and in-house training of site staff are recommended for improving the record keeping practices.展开更多
The heat transfer performance of the phase change materials used in free cooling and air conditioning applications is low,due to the poor thermal conductivity of the materials.The recent phenomenal advancement in nano...The heat transfer performance of the phase change materials used in free cooling and air conditioning applications is low,due to the poor thermal conductivity of the materials.The recent phenomenal advancement in nano technology provides an opportunity for an appreciable enhancement in the thermal conductivity of the phase change materials.In order to explore the possibilities of using nano technology for various applications,a detailed parametric study is carried out,to analyse the heat transfer enhancement potential with the thermal conductivity of the conventional phase change materials and nano enhanced phase change materials under various flow conditions of the heat transfer fluid.Initially,the theoretical equation,used to determine the time for outward cylindrical solidification of the phase change material,is validated with the experimental results.It is inferred from the parametric studies,that for paraffinic phase change materials with air as the heat transfer fluid,the first step should be to increase the heat transfer coefficient to the maximum extent,before making any attempt to increase the thermal conductivity of the phase change materials,with the addition of nano particles.When water is used as the phase change material,the addition of nano particles is recommended to achieve better heat transfer,when a liquid is used as the heat transfer fluid.展开更多
Tornadoes can destroy or severely damage physical infrastructure including buildings in a community.This can result in direct losses but also indirect losses such as the closure of key social institutions reverberatin...Tornadoes can destroy or severely damage physical infrastructure including buildings in a community.This can result in direct losses but also indirect losses such as the closure of key social institutions reverberating further through the community(e.g.,schools).Despite significant losses in past events,building codes and standards have not previously included tornado hazards because of the relatively low probability of a direct strike.The recent release of the ASCE 7-22 standard considers tornadoes for Risk Category 3 and 4 buildings,i.e.ranging from schools to critical facilities.This study proposes a series of design combinations of a reinforced masonry school building with different performance targets intended to enable schools to reopen sooner.Tornado fragilities were developed for a school building having improved designs using tornado loads determined based on the new tornado chapter in ASCE 7-22,and then integrated into a community level model with school attendance zones to examine the effect.The ultimate goal in this study is to investigate the effect of improving school building designs would have on maintaining school continuity(and more rapid return)for school children.展开更多
A practical synthesis of （R）-4-（benzyloxy）-3-methylbutanenitrile, a potential chiral building block, from the corresponding a-keto ester in high yield and large scale was presented.
基金the National Natural Science Foundation of China(Nos.20371007 and 20476011)
文摘A novel three-dimensional（3D） supramolecular architecture, {[Nd（OH-BDC）（OH-HBDC）（H2O）2]·2HaO）n（1） （OH-H2BDC=5-hydroxyisophthalic acid）, which was formed through hydrogen bonds and π-π stacking between two-dimensional（2D） layers, was hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Windmill building blocks, which consist of two nine-coordinated metal centers and four OH-H2BDC groups are connected through two carboxyl groups, to lead to a one-dimensional infinite inorganic chain（… M--O--C--O--M…） along the [100] direction. An observed intense blue luminescence with an emission band peaked at 390 nm for compound 1 may results from ligand-to-metal charge transfer（LMCT）. Variable-temperature magnetic susceptibility of compound 1 was investigated and the value was deviated from the Curie-Weiss law.
文摘To improve the performance of an active mass damper control system,the controller should be designed based on a reduced-order model. An improved method based on balanced truncation method was proposed to reduce the dimension of high-rise buildings,and was compared with other widely used reduction methods by using a framework with ten floors. This optimized method has improvement of reduction process and choice of the order. Based on the reduced-order model obtained by the improved method and pole-assignment algorithm,a controller was designed. Finally,a comparative analysis of structural responses,transfer functions,and poles was conducted on an actual high-rise building. The results show the effectiveness of the improved method.
文摘The publication of ISO 15686-5 is significant for studies related to the life-cycle costs of buildings. Among the many economic evaluation methods, the NPV method is recommended for use by this standard. This study explains the concept and method of PV, and then provides an explanation of the concept and method of NPV, and points out the limitations in the practical application of the method.
基金This work was supported by Chins Textile University and the corporation foundation
文摘The characteristics of body build of middle - and old -aged women and its rule of variations as well as the basic sizes of various parts are discussed. All these are based on the body measurements of this age group, and also on the statistical studies of the measurement data. By setting the regression equation, the calculating formulae of various control parts are obtained, thus establishing the prototype of this age group for women.
文摘The importance of good site progress records in quality assurance; tracking project progress; preparing, analyzing and resolving claims; and placing responsibilities in the event of dispute in building contracts is widely recognized. This study engaged Public Building Supervisors in the assessment of site progress record keeping practices in Abuja. A simple structured questionnaire （which mainly assessed the nature and importance of records kept, reasons for keeping them; level of satisfaction with the current approach, challenges and practical ways of improving the practice） was administrated to a hundred of the supervisors, out of which seventy one was properly completed and returned. The results show that all five site progress documents （minutes of progress meetings, day-work sheets, photographs, weekly site records and personal site diaries） found in literature, are in use in Abuja, and have at least a high importance rating （i.e., relative importance index, 0.6 〈 RII 〈 0.8）. Prominent among the reasons for keeping the records are： control of ongoing work （R11 = 0.83） data for estimating future works and terms of contract requirement （each with RII = 0.823）. Though the present record keeping practices were largely assessed satisfactory, 95% of the Supervisors still yearned for improvement. The challenges to the current practice are consistent with those identified in literature and are： continuity consistency, legibility and accountability; in descending order of frequency of occurrence. Computerization, regular inspection of progress documents by assigned supervisors and in-house training of site staff are recommended for improving the record keeping practices.
文摘The heat transfer performance of the phase change materials used in free cooling and air conditioning applications is low,due to the poor thermal conductivity of the materials.The recent phenomenal advancement in nano technology provides an opportunity for an appreciable enhancement in the thermal conductivity of the phase change materials.In order to explore the possibilities of using nano technology for various applications,a detailed parametric study is carried out,to analyse the heat transfer enhancement potential with the thermal conductivity of the conventional phase change materials and nano enhanced phase change materials under various flow conditions of the heat transfer fluid.Initially,the theoretical equation,used to determine the time for outward cylindrical solidification of the phase change material,is validated with the experimental results.It is inferred from the parametric studies,that for paraffinic phase change materials with air as the heat transfer fluid,the first step should be to increase the heat transfer coefficient to the maximum extent,before making any attempt to increase the thermal conductivity of the phase change materials,with the addition of nano particles.When water is used as the phase change material,the addition of nano particles is recommended to achieve better heat transfer,when a liquid is used as the heat transfer fluid.
基金The Center for Risk-Based Community Resilience Planning is a NIST-funded Center of Excellencethe Center is funded through a cooper-ative agreement between the U.S.National Institute of Standards and Technology and Colorado State University(NIST Financial Assistance Award Numbers:70NANB15H044 and 70NANB20H008).
文摘Tornadoes can destroy or severely damage physical infrastructure including buildings in a community.This can result in direct losses but also indirect losses such as the closure of key social institutions reverberating further through the community(e.g.,schools).Despite significant losses in past events,building codes and standards have not previously included tornado hazards because of the relatively low probability of a direct strike.The recent release of the ASCE 7-22 standard considers tornadoes for Risk Category 3 and 4 buildings,i.e.ranging from schools to critical facilities.This study proposes a series of design combinations of a reinforced masonry school building with different performance targets intended to enable schools to reopen sooner.Tornado fragilities were developed for a school building having improved designs using tornado loads determined based on the new tornado chapter in ASCE 7-22,and then integrated into a community level model with school attendance zones to examine the effect.The ultimate goal in this study is to investigate the effect of improving school building designs would have on maintaining school continuity(and more rapid return)for school children.
文摘A practical synthesis of （R）-4-（benzyloxy）-3-methylbutanenitrile, a potential chiral building block, from the corresponding a-keto ester in high yield and large scale was presented.
