This research is concentrated on the longitudinal vibration of a tapered pipe pile considering the vertical support of the surrounding soil and construction disturbance.First,the pile-soil system is partitioned into f...This research is concentrated on the longitudinal vibration of a tapered pipe pile considering the vertical support of the surrounding soil and construction disturbance.First,the pile-soil system is partitioned into finite segments in the vertical direction and the Voigt model is applied to simulate the vertical support of the surrounding soil acting on the pile segment.The surrounding soil is divided into finite ring-shaped zones in the radial direction to consider the construction disturbance.Then,the shear complex stiffness at the pile-soil interface is derived by solving the dynamic equilibrium equation for the soil from the outermost to innermost zone.The displacement impedance at the top of an arbitrary pile segment is obtained by solving the dynamic equilibrium equation for the pile and is combined with the vertical support of the surrounding soil to derive the displacement impedance at the bottom of the upper adjacent segment.Further,the displacement impedance at the pile head is obtained based on the impedance function transfer technique.Finally,the reliability of the proposed solution is verified,followed by a sensitivity analysis concerning the coupling effect of the pile parameters,construction disturbance and the vertical support of the surrounding soil on the displacement impedance of the pile.展开更多
As the urban populations grow,the number and size of subway construction projects are increasing while also meeting higher construction standards.So,subway construction projects must have a better understanding of con...As the urban populations grow,the number and size of subway construction projects are increasing while also meeting higher construction standards.So,subway construction projects must have a better understanding of construction technology.This article focuses on the construction technology of the subway tunnel expansion under the bridge foundation.By analyzing the engineering characteristics of the bridge foundation and using a project as an example,this article provides a detailed discussion of the construction process of tunnel expansion under a bridge foundation.This article aims to serve as a reference for subway tunnel construction in China to ensure the key points of construction technology are understood,thus improving construction quality and laying a solid technical foundation for the sustainable development of urban rail engineering.展开更多
Municipal civil engineering is the key content of municipal construction,and the construction scale is usually large.The quality of the project plays an important role in the development of urban economy.Due to the ra...Municipal civil engineering is the key content of municipal construction,and the construction scale is usually large.The quality of the project plays an important role in the development of urban economy.Due to the rapid increase of high-rise buildings,skyscrapers and underground buildings,the construction technology of deep foundation pit support has gradually become an indispensable construction technology.Therefore,the selection of foundation pit support construction technology is crucial in ensuring that whether the foundation is firm and stable,and whether the subsequent construction activities can be carried out smoothly.In view of this,the article discusses the application of deep foundation pit support construction technology in municipal civil engineering,aiming to provide reference for subsequent projects.展开更多
The high and large span cast-in-place reinforced concrete cantilever structure of the office building of some court, which is located I-steel at the cantilever and used steel pipe scaffold as the support, has guarante...The high and large span cast-in-place reinforced concrete cantilever structure of the office building of some court, which is located I-steel at the cantilever and used steel pipe scaffold as the support, has guaranteed the frame body and structure security by the frame body calculating, on-site test and reasonable construction order.展开更多
Accurate cost estimation at the early stage of a construction project is key factor in a project’s success. But it is difficult to quickly and accurately estimate construction costs at the planning stage, when drawin...Accurate cost estimation at the early stage of a construction project is key factor in a project’s success. But it is difficult to quickly and accurately estimate construction costs at the planning stage, when drawings, documentation and the like are still incomplete. As such, various techniques have been applied to accurately estimate construction costs at an early stage, when project information is limited. While the various techniques have their pros and cons, there has been little effort made to determine the best technique in terms of cost estimating performance. The objective of this research is to compare the accuracy of three estimating techniques (regression analysis (RA), neural network (NN), and support vector machine techniques (SVM)) by performing estimations of construction costs. By comparing the accuracy of these techniques using historical cost data, it was found that NN model showed more accurate estimation results than the RA and SVM models. Consequently, it is determined that NN model is most suitable for estimating the cost of school building projects.展开更多
This article analyzes the application strategies of shotcrete anchor support technology using a highway bridge-tunnel construction project as an example.The article covers various strategies,including support plan for...This article analyzes the application strategies of shotcrete anchor support technology using a highway bridge-tunnel construction project as an example.The article covers various strategies,including support plan formulation,mortar shotcrete anchor construction,grid steel frame construction,steel mesh construction,and concrete support construction.This analysis aims to provide a guideline for those interested in applying this technology and improving the quality and safety of highway bridges and tunnels construction.展开更多
The country’s economic development determines the political and cultural status.At the present time,China’s rapid economic development has greatly improved the country’s international prominence.Although China has ...The country’s economic development determines the political and cultural status.At the present time,China’s rapid economic development has greatly improved the country’s international prominence.Although China has high economic and political achievements,China’s cultural soft power is still in a weak position.Cultural soft power is of great significance in improving the country’s overall national strength and international competitiveness.Research organizations are an important part of the country’s soft power and are of great significance to the strengthening of national soft power.Research organizations are the“peripheral brain”in the decision-making process of the government.National government agencies need democratic science in making decisions,and the adopted policy methods must have positive and effective outcomes on the people.Therefore,the national government agencies cannot achieve this without the help of research organizations.This resulted in the development and rising construction of research organizations.With the comprehensive development and construction of research organizations,whilst making progress,has also exposed several shortcomings.The construction of China’s research organizations requires various supports;especially the intelligence agencies and access to library information,which has a unique advantage in promoting the construction of research organizations[1].This paper first introduces the definition,classification and characteristics of a research organization.It will also provide a preliminary understanding of research organizations.The paper will then highlight and analyze the problems encountered by the research organization.Finally,through the grasp of the advantages of the library and intelligence agencies,a solution is proposed.展开更多
The cpc's 13th Five-Year comprehensive plan put forward a major historic task of building a new socialist countryside. This is the comprehensive implementation of urban and rural development to increase industrial ag...The cpc's 13th Five-Year comprehensive plan put forward a major historic task of building a new socialist countryside. This is the comprehensive implementation of urban and rural development to increase industrial agriculture, move the city to support the countryside, accelerate urbanization and narrow the gap between urban and rural areas. To solve the "three rural issues", the comprehensive construction ofa well-offsociety, has a very important strategic role to ease the contradiction of China's rural and urban ecnomic structure. In the process of building a new socialist countryside, the financial policy, as an important means ofmacroeconomic regulation and control, should play a leading role in solving the effective allocation &funds. Due to various factors affected by the current supply of rural financial market constraints, system defects and environmental constraints, there is a large gap between the level of the existing rural financial services and the requirements of the new rural construction which is to be improved urgently.展开更多
With the continuous development of the construction industry,the density of engineering construction and the difficulty of underground construction are also increasing.As an important construction protection measure,f...With the continuous development of the construction industry,the density of engineering construction and the difficulty of underground construction are also increasing.As an important construction protection measure,foundation pit support construction is widely used in underground construction.Starting from the characteristics of foundation pit support construction,this paper analyzes the influence of geotechnical investigation on foundation pit support construction,and analyzes the problems that need to be paid attention to in the survey process.展开更多
The compositions, technical principles and construction equipments of a new piling method used for ground improvement plastic tube cast-in-place concrete pile were introduced. The results from static load tests on sin...The compositions, technical principles and construction equipments of a new piling method used for ground improvement plastic tube cast-in-place concrete pile were introduced. The results from static load tests on single piles with different forms of pile shoes and on their composite foundations were analyzed. The distribution patterns of axial force, shaft friction and toe resistance were studied based on the measurements taken from buried strain gauges. From the point of engineering application, the pile has merits in convenient quality control, high bearing capacity and reliable quality, showing higher reasonability, advancement and suitability than other ground improvement methods. The pile can be adopted properly to take place of ordinary ground improvement method, achieving greater economical and social benefits.展开更多
Discipline construction is development core of a professional research institute. The paper describes function,guiding ideology,and construction of discipline construction,based on giving a national-level professional...Discipline construction is development core of a professional research institute. The paper describes function,guiding ideology,and construction of discipline construction,based on giving a national-level professional research institute directly under the Ministry of Science and Technology,as an example. Furthermore,according to current situation of discipline construction in a professional research institute,the paper discusses development ideas of discipline construction. The final goal of the paper is to provide basis and reference for reinforcing discipline construction of professional research institutes.展开更多
In the construction of a soft rock tunnel,it is critical to accurately estimate the pre-stressed anchor support parameters for surrounding rock reinforcement;otherwise,engineering disasters may occur.This paper presen...In the construction of a soft rock tunnel,it is critical to accurately estimate the pre-stressed anchor support parameters for surrounding rock reinforcement;otherwise,engineering disasters may occur.This paper presents a support parameter selection method that aims to allow deformation as a control objective,which was applied to the tunnel located in Muzailing Highway,Min County,Dingxi City,Gansu Province,China.Through theoretical analysis,we have identified five factors that influence pre-stressing anchorages.The selection of mechanical parameters for the rock mass was carried out using an inverse analysis method.Compared with the measured data,the maximum displacement error of the numerical simulation results was only 0.07 m.The length of anchor cable,circumferential spacing of anchor cable,longitudinal spacing,and pre-stress index are adopted as the input parameters for the support vector machine neural network model based on particle swarm optimization(PSO-LSSVM).Besides,the vault subsidence and the maximum deformation of surrounding rock are considered as output values(performance indices).The goodness of fit between the predicted values and the simulated values exceeds 0.9.Finally,all support parameters within the acceptable deformation range are calculated.The optimal support variables are derived by considering the construction cost and duration.The field application results show that it is feasible to construct the sample database utilizing the numerical simulation approach by taking the displacement as the control target and using the neural network to specify the appropriate support parameters.展开更多
Survey and research of new socialist countryside construction in Hebei Province are favorable for determining approaches and construction mode of new socialist countryside in other areas,and favorable for advancing th...Survey and research of new socialist countryside construction in Hebei Province are favorable for determining approaches and construction mode of new socialist countryside in other areas,and favorable for advancing the urban and rural integration in Hebei Province. With the aid of GIS technology,it is able to create spatial information database,correlate with rural statistical data and spatial information. Then,in the form of thematic map,it can visually indicate current situations of rural economy,and existing problems of development. Finally,it is expected to promote rural information construction and guide new countryside planning,to facilitate inquiry and search of information,and to provide supporting decisions for new socialist countryside construction.展开更多
Urbanization and living comfort have revolutionized the construction industry. Many techniques and strategies have been used to improve the overall efficiency of construction and to reduce waste during and after the c...Urbanization and living comfort have revolutionized the construction industry. Many techniques and strategies have been used to improve the overall efficiency of construction and to reduce waste during and after the construction activity;some are cost effective and some not. Sustainable construction strategies have addressed these issues by proposing relatively more cost effective and environment-saving solutions. One strategy is to select sustainable construction materials at the building design stage. This article involved a questionnaire survey to collect data about local technical stakeholders’ (architects, designers, engineers, estimators, and managers) awareness of environmental sustainability and current practices for selecting construction materials. A sustainability index (SI) was developed using SPSS (Statistical Package for the Social Sciences) for the complex statistical analysis. These data were used to develop a decision support system (DSS) using the multi-criteria decision making (MCDM) technique, the TOPSIS. The support system was validated by applying it to sustainable roof products in a pilot case study—these materials are frequently used in local markets for residential construction in West Australia. So the main objective was to get insight to local market trends and features involved in construction materials selection. Data analysis was carried out to develop a decision support system to help technical stakeholders in construction materials selection process.展开更多
According to practice and exploration of spark program for 26 years in Quanzhou,the main model and their effects of new rural construction in west bank of Taiwan Strait led by spark science and technology were expound...According to practice and exploration of spark program for 26 years in Quanzhou,the main model and their effects of new rural construction in west bank of Taiwan Strait led by spark science and technology were expounded. Six spark program systems were established,consisting of policy support guide,science and technology project lead,experts' intelligence support,spark science and technology training,scitech information service and spark program demonstration. Five spark projects were implemented to promote new rural construction in the west bank of Taiwan Strait,such as constructing the national spark industrial zone,organizing the new rural construction led by science and technology,constituting spark sci-tech innovation center,developing the rural informatization,and establishing science and technology commissioner bases. Finally,enlightenment of spark program and its development ways in the future were put forward.展开更多
Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oli- gomers and constructed a h...Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oli- gomers and constructed a have human Fab phage display library based on blood samples from six healthy people. After three rounds of biopanning in vitro, a human single-domain antibody that spe- cifically recognized amyloid-beta 42 oligomers was identified. Western blot and enzyme-linked im- munosorbent assay demonstrated this antibody bound specifically to human amyloid-beta 42 tetramer and nonamer, but not the monomer or high molecular weight oligomers. This study suc- cessfully constructed a human phage display library and screened a single-domain antibody that specifically recognized amyloid-beta 42 oligomers.展开更多
基金National Natural Science Foundation of China under Grand No.51808190the Central Government Guides Local Science and Technology Development Fund Projects under Grand No.XZ202301YD0019C+2 种基金the Foundation of Key Laboratory of Soft Soils and Geoenvironmental Engineering(Zhejiang University)Ministry of Education under Grand No.2022P04the Central University Basic Research Fund of China under Grand No.B220202017。
文摘This research is concentrated on the longitudinal vibration of a tapered pipe pile considering the vertical support of the surrounding soil and construction disturbance.First,the pile-soil system is partitioned into finite segments in the vertical direction and the Voigt model is applied to simulate the vertical support of the surrounding soil acting on the pile segment.The surrounding soil is divided into finite ring-shaped zones in the radial direction to consider the construction disturbance.Then,the shear complex stiffness at the pile-soil interface is derived by solving the dynamic equilibrium equation for the soil from the outermost to innermost zone.The displacement impedance at the top of an arbitrary pile segment is obtained by solving the dynamic equilibrium equation for the pile and is combined with the vertical support of the surrounding soil to derive the displacement impedance at the bottom of the upper adjacent segment.Further,the displacement impedance at the pile head is obtained based on the impedance function transfer technique.Finally,the reliability of the proposed solution is verified,followed by a sensitivity analysis concerning the coupling effect of the pile parameters,construction disturbance and the vertical support of the surrounding soil on the displacement impedance of the pile.
文摘As the urban populations grow,the number and size of subway construction projects are increasing while also meeting higher construction standards.So,subway construction projects must have a better understanding of construction technology.This article focuses on the construction technology of the subway tunnel expansion under the bridge foundation.By analyzing the engineering characteristics of the bridge foundation and using a project as an example,this article provides a detailed discussion of the construction process of tunnel expansion under a bridge foundation.This article aims to serve as a reference for subway tunnel construction in China to ensure the key points of construction technology are understood,thus improving construction quality and laying a solid technical foundation for the sustainable development of urban rail engineering.
文摘Municipal civil engineering is the key content of municipal construction,and the construction scale is usually large.The quality of the project plays an important role in the development of urban economy.Due to the rapid increase of high-rise buildings,skyscrapers and underground buildings,the construction technology of deep foundation pit support has gradually become an indispensable construction technology.Therefore,the selection of foundation pit support construction technology is crucial in ensuring that whether the foundation is firm and stable,and whether the subsequent construction activities can be carried out smoothly.In view of this,the article discusses the application of deep foundation pit support construction technology in municipal civil engineering,aiming to provide reference for subsequent projects.
文摘The high and large span cast-in-place reinforced concrete cantilever structure of the office building of some court, which is located I-steel at the cantilever and used steel pipe scaffold as the support, has guaranteed the frame body and structure security by the frame body calculating, on-site test and reasonable construction order.
文摘Accurate cost estimation at the early stage of a construction project is key factor in a project’s success. But it is difficult to quickly and accurately estimate construction costs at the planning stage, when drawings, documentation and the like are still incomplete. As such, various techniques have been applied to accurately estimate construction costs at an early stage, when project information is limited. While the various techniques have their pros and cons, there has been little effort made to determine the best technique in terms of cost estimating performance. The objective of this research is to compare the accuracy of three estimating techniques (regression analysis (RA), neural network (NN), and support vector machine techniques (SVM)) by performing estimations of construction costs. By comparing the accuracy of these techniques using historical cost data, it was found that NN model showed more accurate estimation results than the RA and SVM models. Consequently, it is determined that NN model is most suitable for estimating the cost of school building projects.
文摘This article analyzes the application strategies of shotcrete anchor support technology using a highway bridge-tunnel construction project as an example.The article covers various strategies,including support plan formulation,mortar shotcrete anchor construction,grid steel frame construction,steel mesh construction,and concrete support construction.This analysis aims to provide a guideline for those interested in applying this technology and improving the quality and safety of highway bridges and tunnels construction.
文摘The country’s economic development determines the political and cultural status.At the present time,China’s rapid economic development has greatly improved the country’s international prominence.Although China has high economic and political achievements,China’s cultural soft power is still in a weak position.Cultural soft power is of great significance in improving the country’s overall national strength and international competitiveness.Research organizations are an important part of the country’s soft power and are of great significance to the strengthening of national soft power.Research organizations are the“peripheral brain”in the decision-making process of the government.National government agencies need democratic science in making decisions,and the adopted policy methods must have positive and effective outcomes on the people.Therefore,the national government agencies cannot achieve this without the help of research organizations.This resulted in the development and rising construction of research organizations.With the comprehensive development and construction of research organizations,whilst making progress,has also exposed several shortcomings.The construction of China’s research organizations requires various supports;especially the intelligence agencies and access to library information,which has a unique advantage in promoting the construction of research organizations[1].This paper first introduces the definition,classification and characteristics of a research organization.It will also provide a preliminary understanding of research organizations.The paper will then highlight and analyze the problems encountered by the research organization.Finally,through the grasp of the advantages of the library and intelligence agencies,a solution is proposed.
文摘The cpc's 13th Five-Year comprehensive plan put forward a major historic task of building a new socialist countryside. This is the comprehensive implementation of urban and rural development to increase industrial agriculture, move the city to support the countryside, accelerate urbanization and narrow the gap between urban and rural areas. To solve the "three rural issues", the comprehensive construction ofa well-offsociety, has a very important strategic role to ease the contradiction of China's rural and urban ecnomic structure. In the process of building a new socialist countryside, the financial policy, as an important means ofmacroeconomic regulation and control, should play a leading role in solving the effective allocation &funds. Due to various factors affected by the current supply of rural financial market constraints, system defects and environmental constraints, there is a large gap between the level of the existing rural financial services and the requirements of the new rural construction which is to be improved urgently.
文摘With the continuous development of the construction industry,the density of engineering construction and the difficulty of underground construction are also increasing.As an important construction protection measure,foundation pit support construction is widely used in underground construction.Starting from the characteristics of foundation pit support construction,this paper analyzes the influence of geotechnical investigation on foundation pit support construction,and analyzes the problems that need to be paid attention to in the survey process.
基金Project (2007H03) supported by Communications Department of Zhejiang Province
文摘The compositions, technical principles and construction equipments of a new piling method used for ground improvement plastic tube cast-in-place concrete pile were introduced. The results from static load tests on single piles with different forms of pile shoes and on their composite foundations were analyzed. The distribution patterns of axial force, shaft friction and toe resistance were studied based on the measurements taken from buried strain gauges. From the point of engineering application, the pile has merits in convenient quality control, high bearing capacity and reliable quality, showing higher reasonability, advancement and suitability than other ground improvement methods. The pile can be adopted properly to take place of ordinary ground improvement method, achieving greater economical and social benefits.
基金Supported by the Project of “Meteorological Science and Technology Development Strategy Research” of Chinese Meteorological Society
文摘Discipline construction is development core of a professional research institute. The paper describes function,guiding ideology,and construction of discipline construction,based on giving a national-level professional research institute directly under the Ministry of Science and Technology,as an example. Furthermore,according to current situation of discipline construction in a professional research institute,the paper discusses development ideas of discipline construction. The final goal of the paper is to provide basis and reference for reinforcing discipline construction of professional research institutes.
基金supported by the Open Fund of State Key Laboratory of High speed Railway Track Technology(2022YJ127-1)National Natural Science Foundation of China(52104125,41941018)+1 种基金the Natural Science Basic Research Plan in Shaanxi Province of China(2022JQ-304)the Young Elite Scientists Sponsorship Program by CAST(No.2021QNRC001)。
文摘In the construction of a soft rock tunnel,it is critical to accurately estimate the pre-stressed anchor support parameters for surrounding rock reinforcement;otherwise,engineering disasters may occur.This paper presents a support parameter selection method that aims to allow deformation as a control objective,which was applied to the tunnel located in Muzailing Highway,Min County,Dingxi City,Gansu Province,China.Through theoretical analysis,we have identified five factors that influence pre-stressing anchorages.The selection of mechanical parameters for the rock mass was carried out using an inverse analysis method.Compared with the measured data,the maximum displacement error of the numerical simulation results was only 0.07 m.The length of anchor cable,circumferential spacing of anchor cable,longitudinal spacing,and pre-stress index are adopted as the input parameters for the support vector machine neural network model based on particle swarm optimization(PSO-LSSVM).Besides,the vault subsidence and the maximum deformation of surrounding rock are considered as output values(performance indices).The goodness of fit between the predicted values and the simulated values exceeds 0.9.Finally,all support parameters within the acceptable deformation range are calculated.The optimal support variables are derived by considering the construction cost and duration.The field application results show that it is feasible to construct the sample database utilizing the numerical simulation approach by taking the displacement as the control target and using the neural network to specify the appropriate support parameters.
基金Supported by Project of 2011 Hebei Provincial Social Science Development Research(201104060)Project of Hebei Provincial Soft Science Research Plan(10457203D-22)
文摘Survey and research of new socialist countryside construction in Hebei Province are favorable for determining approaches and construction mode of new socialist countryside in other areas,and favorable for advancing the urban and rural integration in Hebei Province. With the aid of GIS technology,it is able to create spatial information database,correlate with rural statistical data and spatial information. Then,in the form of thematic map,it can visually indicate current situations of rural economy,and existing problems of development. Finally,it is expected to promote rural information construction and guide new countryside planning,to facilitate inquiry and search of information,and to provide supporting decisions for new socialist countryside construction.
文摘Urbanization and living comfort have revolutionized the construction industry. Many techniques and strategies have been used to improve the overall efficiency of construction and to reduce waste during and after the construction activity;some are cost effective and some not. Sustainable construction strategies have addressed these issues by proposing relatively more cost effective and environment-saving solutions. One strategy is to select sustainable construction materials at the building design stage. This article involved a questionnaire survey to collect data about local technical stakeholders’ (architects, designers, engineers, estimators, and managers) awareness of environmental sustainability and current practices for selecting construction materials. A sustainability index (SI) was developed using SPSS (Statistical Package for the Social Sciences) for the complex statistical analysis. These data were used to develop a decision support system (DSS) using the multi-criteria decision making (MCDM) technique, the TOPSIS. The support system was validated by applying it to sustainable roof products in a pilot case study—these materials are frequently used in local markets for residential construction in West Australia. So the main objective was to get insight to local market trends and features involved in construction materials selection. Data analysis was carried out to develop a decision support system to help technical stakeholders in construction materials selection process.
基金Supported by the Regional Science and Technology Project of Fujian Province,China(2009N3007)Science and Technology Project of Quanzhou City,Fujian Province,China(2008ZD11-1)12396 Multimedia Information Remote Service Platform Construction of Spark Science and Technology for Quanzhou City,Fujian Province,China(2008ZD15,2011ZD04N01)
文摘According to practice and exploration of spark program for 26 years in Quanzhou,the main model and their effects of new rural construction in west bank of Taiwan Strait led by spark science and technology were expounded. Six spark program systems were established,consisting of policy support guide,science and technology project lead,experts' intelligence support,spark science and technology training,scitech information service and spark program demonstration. Five spark projects were implemented to promote new rural construction in the west bank of Taiwan Strait,such as constructing the national spark industrial zone,organizing the new rural construction led by science and technology,constituting spark sci-tech innovation center,developing the rural informatization,and establishing science and technology commissioner bases. Finally,enlightenment of spark program and its development ways in the future were put forward.
基金supported by the National Natural Science Foundation of China,No.30600099(FD)
文摘Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oli- gomers and constructed a have human Fab phage display library based on blood samples from six healthy people. After three rounds of biopanning in vitro, a human single-domain antibody that spe- cifically recognized amyloid-beta 42 oligomers was identified. Western blot and enzyme-linked im- munosorbent assay demonstrated this antibody bound specifically to human amyloid-beta 42 tetramer and nonamer, but not the monomer or high molecular weight oligomers. This study suc- cessfully constructed a human phage display library and screened a single-domain antibody that specifically recognized amyloid-beta 42 oligomers.