The maize mutant gene Vestigial glume 1(Vg1) has been fine-mapped to a narrow region by map-based cloning and the candidate gene for Vg1 spanned 19.5 kb. Here we report Vg1 genomic fosmid library construction and scre...The maize mutant gene Vestigial glume 1(Vg1) has been fine-mapped to a narrow region by map-based cloning and the candidate gene for Vg1 spanned 19.5 kb. Here we report Vg1 genomic fosmid library construction and screening. The fosmid library of Vg1 consisted of574,000 clones with an average insert size of 36.4 kb, representing 7.9-fold coverage of the maize genome. Fosmid stability assays indicated that clones were stable during propagation in the fosmid system. Using Vg1 candidate gene-specific primers, a positive clone was successfully identified. This discovery will pave the way for identifying the function of Vg1 in maize development.展开更多
Integrative physical mapping is the centerpieceof and essential for advanced genomics research.Upland cotton(Gossypium hirsutum L.)geneticstandard line TM-1 is used as the referencegenotype to develop a whole-genome,B...Integrative physical mapping is the centerpieceof and essential for advanced genomics research.Upland cotton(Gossypium hirsutum L.)geneticstandard line TM-1 is used as the referencegenotype to develop a whole-genome,BAC/BIBAC-based integrated physical/genetic map ofthe cotton genome.From the TM-1 line we haveconstructed two BAC libraries with HindIII展开更多
By making use of the technical advantages of Guangzhou Huibiao Testing Technology Center in the field of testing, the project analyzes the characteristics of undergraduate professional education in aquatic animal medi...By making use of the technical advantages of Guangzhou Huibiao Testing Technology Center in the field of testing, the project analyzes the characteristics of undergraduate professional education in aquatic animal medicine, and intends to build a case library of Inspection and Quarantine of Aquatic Animal suitable for modern undergraduate teaching needs, with training applied talents to meet the requirements of the times as the goal, and strengthening the reform of college education mode and improving the quantity and quality of talent training as the guiding ideology.展开更多
Pepper(Capsicum annuum.L.) is a widely cultivated vegetable crop worldwide and has the second largest planting area and the first largest vegetable output and value in China.Pepper root-knot nematode(Meloidogyne spp.)...Pepper(Capsicum annuum.L.) is a widely cultivated vegetable crop worldwide and has the second largest planting area and the first largest vegetable output and value in China.Pepper root-knot nematode(Meloidogyne spp.) is one of the most serious pests of pepper,which caused huge losses every year.Previous studies showed that the Me3 gene is resistant to a wide range of Meloidogyne species,including M.arenaria,M.javanica,and M.incognita.HDA149,a double haploid pepper genotype,harboring the root-knot nematode resistance gene Me3,was used to construct bacterial artificial chromosome library(BAC) via the vector of CopyControl^(TM) pCC1 in this study.The library consists of 210200 BAC clones and is equivalent to 5.3 pepper genomes.The average insert size is 95 kb,and most of them are 90-120 kb;but the empty clones are less than 3%.In order to screen the BAC library easily,550 super pools with 384 BAC clones of each pool were further developed in this study.Specific primers from Me3 gene locus were used for BAC library screening,and more than 20 positive BAC clones were obtained.Then the selected positive BAC clones were analyzed by restriction enzyme digestion,BAC-end sequencing,marker development,and new positive BAC clones exploration,respectively.Finally,the contig with total length of about 300 kb linked to the Me3 locus was constructed based on chromosome walking strategy,which made a solid foundation for the cloning of the important root-knot nematode resistance gene Me3.展开更多
The human microbiome plays a crucial role in human health.In the past decade,advances in high-throughput sequencing technologies and analytical software have significantly improved our knowledge of the human microbiom...The human microbiome plays a crucial role in human health.In the past decade,advances in high-throughput sequencing technologies and analytical software have significantly improved our knowledge of the human microbiome.However,most studies concerning the human microbiome did not provide repeatable protocols to guide the sample collection,handling,and processing procedures,which impedes obtaining valid and timely microbial taxonomic and functional results.This protocol provides detailed operation methods of human microbial sample collection,DNA extraction,and library construction for both the amplicon sequencing-based measurements of the microbial samples from the human nasal cavity,oral cavity,and skin,as well as the shotgun metagenomic sequencing-based measurements of the human stool samples among adult par-ticipants.This study intends to develop practical procedure standards to improve the reproducibility of microbiota profiling of human samples.展开更多
High-throughput sequencing of amplicons has been widely used to precisely and efficiently identify species compositions and analyze community structures,greatly promoting biological studies involving large amounts of ...High-throughput sequencing of amplicons has been widely used to precisely and efficiently identify species compositions and analyze community structures,greatly promoting biological studies involving large amounts of complex samples,especially those involving environmental and pathogen-monitoring ones.Commercial library preparation kits for amplicon sequencing,which generally require multiple steps,including adapter ligation and indexing,are expensive and time-consuming,especially for applications at a large scale.To overcome these limitations,a“one-step PCR approach”has been previously proposed for constructions of amplicon libraries using long fusion primers.However,efficient amplifications of target genes and accurate demultiplexing of pooled sequencing data remain to be addressed.To tackle these,we present an integrative protocol for one-step PCR amplicon library construction(OSPALC).High-quality reads have been generated by this approach to reliably identify species compositions of mock bacterial communities and environmental samples.With this protocol,the amplicon library is constructed through one regular PCR with long primers,and the total cost per DNA/cDNA sample decreases to just 7%of the typical cost via the multi-step PCR approach.Empirically tested primers and optimized PCR conditions to construct OSPALC libraries for 16S rDNA V4 regions are demonstrated as a case study.Tools to design primers targeting at any genomic regions are also presented.In principle,OSPALC can be readily applied to construct amplicon libraries of any target genes using DNA or RNA samples,and will facilitate research in numerous fields.展开更多
Metaverse is a virtual world,but it is possible and even becomes a trend that metaverse interacts with the real world along with the sci-tech and social development.Smart library is a main direction of modern library ...Metaverse is a virtual world,but it is possible and even becomes a trend that metaverse interacts with the real world along with the sci-tech and social development.Smart library is a main direction of modern library development,from informatization to digitization and then intelligent-based,modernization of library has been improved qualitatively.Emergence of metaverse brings a brand-new horizon to the generation and application of agricultural information,this paper made primary explorations the requirements and action mechanism of agricultural information on the construction of smart library within the external constraint of metaverse.展开更多
Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-st...Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-strand breaks of DNA,causing insertional mutation.The random insertional mutant library constructed using this method has become a method of forward genetics for gene cloning.However,the establishment of a random insertional mutant library requires a high transformation efficiency of exogenous genes.Many microalgal species show a low transformation efficiency,making constructing random insertional mutant libraries difficult.In this study,we established a highly efficient transformation method for constructing a random insertional mutant library of Nannochloropsis oceanica,and tentatively tried to isolate its genes to prove the feasibility of the method.A gene that may control the growth rate and cell size was identified.This method will facilitate the genetic studies of N.oceanica,which should also be a reference for other microalgal species.展开更多
Automatic control technology is the basis of road robot improvement,according to the characteristics of construction equipment and functions,the research will be input type perception from positioning acquisition,real...Automatic control technology is the basis of road robot improvement,according to the characteristics of construction equipment and functions,the research will be input type perception from positioning acquisition,real-world monitoring,the process will use RTK-GNSS positional perception technology,by projecting the left side of the earth from Gauss-Krueger projection method,and then carry out the Cartesian conversion based on the characteristics of drawing;steering control system is the core of the electric drive unmanned module,on the basis of the analysis of the composition of the steering system of unmanned engineering vehicles,the steering system key components such as direction,torque sensor,drive motor and other models are established,the joint simulation model of unmanned engineering vehicles is established,the steering controller is designed using the PID method,the simulation results show that the control method can meet the construction path demand for automatic steering.The path planning will first formulate the construction area with preset values and realize the steering angle correction during driving by PID algorithm,and never realize the construction-based path planning,and the results show that the method can control the straight path within the error of 10 cm and the curve error within 20 cm.With the collaboration of various modules,the automatic construction simulation results of this robot show that the design path and control method is effective.展开更多
This paper studies and explores the construction of a teaching resource library for landscape engineering under the“4321”industry-education integration system,focusing on the construction objectives,construction pat...This paper studies and explores the construction of a teaching resource library for landscape engineering under the“4321”industry-education integration system,focusing on the construction objectives,construction paths,and construction contents,aiming to open-up the channel of school-enterprise cooperation,improve enterprise participation,and promote the reform of teaching mode and teaching methods.Establishing a practical resource library will connect and integrate students,teachers,and enterprises.A complete library of landscape-oriented teaching resources will be constructed according to the talent portraits of the industry to open-up the relationship between upstream and downstream courses,and further improve the precise fit between the cultivation of applied undergraduate talents and enterprises.展开更多
Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capa...Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.展开更多
To achieve accurate classification and recognition of ship target types,it is necessary to establish a sample library of ship targets to be identified.On the basis of exploring the principles of building a ship target...To achieve accurate classification and recognition of ship target types,it is necessary to establish a sample library of ship targets to be identified.On the basis of exploring the principles of building a ship target image library,the paper determines the sample set.Using 3DS MAX software as the platform,combined with the accurate 3D model of the ship in an offline state,the software fully utilizes its own rendering and animation functions to achieve the automatic generation of multi-view and multi-scale views of ship targets.To reduce the storage capacity of the image database,a construction method of the ship target image database based on the AP algorithm is presented.The algorithm can obtain the optimal cluster number,reduce the data storage capacity of the image database,and save the calculation amount for the subsequent matching calculation.展开更多
The paper is based on literature search,introducing and analyzing the book publishing situation of modern Peking University Library from the perspective of the publisher being Peking University Library and its predece...The paper is based on literature search,introducing and analyzing the book publishing situation of modern Peking University Library from the perspective of the publisher being Peking University Library and its predecessor.It is pointed out that the majority of the book printing methods published by the modern Peking University Library are lead printing,and among the types of Chinese library classification,catalogue of library collections is the most common.展开更多
Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between mar...Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between marine clay and structural materials with different roughness was studied in this paper by using 3D optical scanning tests,a modified direct shear device and numerical simulation.Relationships between the surface roughness of structures,water content and interface friction angle were presented by model tests.The increase of water contents decreased the interface friction angles.For interfaces with different roughness,the interface friction angles will be smaller than that of the soil when the water content exceeds a certain value.The roughness of the interface and the water content of the soil are mutually coupled to influence the coefficient of friction(COF).This paper proposed a Finite Element Method(FEM)to simulate the interface direct shear tests of structures with different roughness.The surface models with different roughness are established based on the structure data obtained by 3D scanning.The Coupled Eulerian-Lagrangian(CEL)approach was employed to analyse soils sheared by irregular surfaces.The interface behavior for interfaces with different roughness under cyclic shear stresses was analyzed by FEM.展开更多
Taking the changes of construction land in Wan’an County over the years as the research object,the quantity and spatial characteristics of construction land in Wan’an County were analyzed,and the overall situation a...Taking the changes of construction land in Wan’an County over the years as the research object,the quantity and spatial characteristics of construction land in Wan’an County were analyzed,and the overall situation and regional differences of construction land utilization in Wan’an County were revealed.From the aspects of main influencing factors such as land use structure,land use intensity,land input intensity and output benefit,an evaluation indicator system was established to evaluate the economical and intensive use level of construction land in Wan’an County.The results show that the score of the economical and intensive use level of construction land in Wan’an County was 56.92,which was the lowest among all the districts and counties in Ji’an City.Based on the evaluation results,the corresponding economizing and intensive strategies were put forward,and the safeguard measures for its implementation were explored.The purpose is to provide some support for the preparation of territorial spatial planning,the delineation of urban development boundaries,and the potential exploitation of construction land stock,hoping to improve the utilization efficiency and benefit of construction land in Wan’an County,and promote the economic growth of Wan’an County to the stage of high-quality development.展开更多
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
Cochin Port is an all-weather port situated within a protected natural harbour,just 11 km away from mainland shipping route.Total draft of 15m-16m is available and it is a natural choice for setting up transhipment hu...Cochin Port is an all-weather port situated within a protected natural harbour,just 11 km away from mainland shipping route.Total draft of 15m-16m is available and it is a natural choice for setting up transhipment hub.The International Container Transhipment Terminal(ICTT)at Vallarpadam was developed by DP World and M/s Cochin Port Trust(CPT).As a part of this project,the new Rail connectivity from ICTT at Vallarpadam to Idappalli station is 8.60km,including the construction of 4.62 km elevated bridge was awarded to AFCONS by M/s Rail Vikas Nigam Limited(RVNL),in 2007 with a scheduled completion by 2009.This bridge is constructed for single railway track and piling was done for the provision of a second railway track in future.The 4.62 km long bridge was successfully completed and Trial Loco run was done in March 2010.This paper includes details of sub-surface profile,engineering properties of soils,details of construction of pile foundations and Challenges faced during construction.展开更多
This paper describes and provides a critique of the design and implementation of the“scoops”-a set of bespoke multifunctioning architectural free-form elements that are a highlight of the new Soheil Abedian School o...This paper describes and provides a critique of the design and implementation of the“scoops”-a set of bespoke multifunctioning architectural free-form elements that are a highlight of the new Soheil Abedian School of Architecture at Bond University,Australia,by the office of Sir Peter Cook and Gavin Robotham,CRAB(Cook Robotham Architecture Bureau,London).The development includes the transfer of analogue design processes into digital 3d modeling,which is then analyzed and rationalized via an exchange with consultants and procurement contractors.The complexity of the concrete works necessitated the use of digital fabrication to make their implementation affordable and within time constraints,with said complexity creating a variety of challenges for many aspects of the entire delivery team.The 3d model played a critical role in communicating intent and accuracy at all stages.The use of site-based craftsmanship combined with computer aided design and fabrication overlapped to realize the project.展开更多
基金supported by a Chongqing Postdoctoral Science Foundation funded project (Xm201344)China Postdoctoral Science Foundation funded project (2014M552303)Fundamental Research Funds for the Central Universities (XDJK2013C023, 2362015xk05)
文摘The maize mutant gene Vestigial glume 1(Vg1) has been fine-mapped to a narrow region by map-based cloning and the candidate gene for Vg1 spanned 19.5 kb. Here we report Vg1 genomic fosmid library construction and screening. The fosmid library of Vg1 consisted of574,000 clones with an average insert size of 36.4 kb, representing 7.9-fold coverage of the maize genome. Fosmid stability assays indicated that clones were stable during propagation in the fosmid system. Using Vg1 candidate gene-specific primers, a positive clone was successfully identified. This discovery will pave the way for identifying the function of Vg1 in maize development.
文摘Integrative physical mapping is the centerpieceof and essential for advanced genomics research.Upland cotton(Gossypium hirsutum L.)geneticstandard line TM-1 is used as the referencegenotype to develop a whole-genome,BAC/BIBAC-based integrated physical/genetic map ofthe cotton genome.From the TM-1 line we haveconstructed two BAC libraries with HindIII
基金Supported by Reform Project of Teaching Content and Curriculum System of Industry-University-Research Cooperation of the Ministry of Education(202101134003)Applied Talents Training Course of Guangdong Ocean University (EAGOU [2019]86)+1 种基金Degree and Postgraduate Education Reform Research Project of Guangdong Ocean University (202120)Postgraduate Education Innovation Project of Guangdong Province (YJYH [2022]1)。
文摘By making use of the technical advantages of Guangzhou Huibiao Testing Technology Center in the field of testing, the project analyzes the characteristics of undergraduate professional education in aquatic animal medicine, and intends to build a case library of Inspection and Quarantine of Aquatic Animal suitable for modern undergraduate teaching needs, with training applied talents to meet the requirements of the times as the goal, and strengthening the reform of college education mode and improving the quantity and quality of talent training as the guiding ideology.
基金supported by the National High-Tech R&D Program in China (2013AA102603)the Natural Science Foundation of Shandong Province,China (ZR2014YL014)+3 种基金the Youth Scientific Research Foundation of Shandong Academy of Agricultural Sciences,China (2014QNZ03)the Taishan Scholars Program of Shandong Province,China (2016-2020)the National Natural Science Foundation of China (31101425)Prof. Alain Palloxin,French National Institute for Agricultural Research (INRA),for kindly providing the pepper genotype HDA149
文摘Pepper(Capsicum annuum.L.) is a widely cultivated vegetable crop worldwide and has the second largest planting area and the first largest vegetable output and value in China.Pepper root-knot nematode(Meloidogyne spp.) is one of the most serious pests of pepper,which caused huge losses every year.Previous studies showed that the Me3 gene is resistant to a wide range of Meloidogyne species,including M.arenaria,M.javanica,and M.incognita.HDA149,a double haploid pepper genotype,harboring the root-knot nematode resistance gene Me3,was used to construct bacterial artificial chromosome library(BAC) via the vector of CopyControl^(TM) pCC1 in this study.The library consists of 210200 BAC clones and is equivalent to 5.3 pepper genomes.The average insert size is 95 kb,and most of them are 90-120 kb;but the empty clones are less than 3%.In order to screen the BAC library easily,550 super pools with 384 BAC clones of each pool were further developed in this study.Specific primers from Me3 gene locus were used for BAC library screening,and more than 20 positive BAC clones were obtained.Then the selected positive BAC clones were analyzed by restriction enzyme digestion,BAC-end sequencing,marker development,and new positive BAC clones exploration,respectively.Finally,the contig with total length of about 300 kb linked to the Me3 locus was constructed based on chromosome walking strategy,which made a solid foundation for the cloning of the important root-knot nematode resistance gene Me3.
基金supported by the National Key Research and Development Program of China(2021YFA1301000)the Shanghai Municipal Science and Technology Major Project(2017SHZDZX01).
文摘The human microbiome plays a crucial role in human health.In the past decade,advances in high-throughput sequencing technologies and analytical software have significantly improved our knowledge of the human microbiome.However,most studies concerning the human microbiome did not provide repeatable protocols to guide the sample collection,handling,and processing procedures,which impedes obtaining valid and timely microbial taxonomic and functional results.This protocol provides detailed operation methods of human microbial sample collection,DNA extraction,and library construction for both the amplicon sequencing-based measurements of the microbial samples from the human nasal cavity,oral cavity,and skin,as well as the shotgun metagenomic sequencing-based measurements of the human stool samples among adult par-ticipants.This study intends to develop practical procedure standards to improve the reproducibility of microbiota profiling of human samples.
基金supported by the National Natural Science Foundation of China(31961123002,31872228)the Fundamental Research Funds for the Central Universities of China(202041001)+1 种基金the Young Taishan Scholars Program of Shandong Province(tsqn201812024)the National Science Foundation(DEB-1927159).
文摘High-throughput sequencing of amplicons has been widely used to precisely and efficiently identify species compositions and analyze community structures,greatly promoting biological studies involving large amounts of complex samples,especially those involving environmental and pathogen-monitoring ones.Commercial library preparation kits for amplicon sequencing,which generally require multiple steps,including adapter ligation and indexing,are expensive and time-consuming,especially for applications at a large scale.To overcome these limitations,a“one-step PCR approach”has been previously proposed for constructions of amplicon libraries using long fusion primers.However,efficient amplifications of target genes and accurate demultiplexing of pooled sequencing data remain to be addressed.To tackle these,we present an integrative protocol for one-step PCR amplicon library construction(OSPALC).High-quality reads have been generated by this approach to reliably identify species compositions of mock bacterial communities and environmental samples.With this protocol,the amplicon library is constructed through one regular PCR with long primers,and the total cost per DNA/cDNA sample decreases to just 7%of the typical cost via the multi-step PCR approach.Empirically tested primers and optimized PCR conditions to construct OSPALC libraries for 16S rDNA V4 regions are demonstrated as a case study.Tools to design primers targeting at any genomic regions are also presented.In principle,OSPALC can be readily applied to construct amplicon libraries of any target genes using DNA or RNA samples,and will facilitate research in numerous fields.
基金Sponsored by 2021-2022 Key Education and Teaching Reform Project of Beijing University of Agriculture:Cultivation of College Students Humanity Quality Based on the Smart Library Construction.
文摘Metaverse is a virtual world,but it is possible and even becomes a trend that metaverse interacts with the real world along with the sci-tech and social development.Smart library is a main direction of modern library development,from informatization to digitization and then intelligent-based,modernization of library has been improved qualitatively.Emergence of metaverse brings a brand-new horizon to the generation and application of agricultural information,this paper made primary explorations the requirements and action mechanism of agricultural information on the construction of smart library within the external constraint of metaverse.
基金the National Key R&D Program of China(Nos.2018YFD0901506,2018YFD0900305)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018 SDKJ0406-3)。
文摘Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-strand breaks of DNA,causing insertional mutation.The random insertional mutant library constructed using this method has become a method of forward genetics for gene cloning.However,the establishment of a random insertional mutant library requires a high transformation efficiency of exogenous genes.Many microalgal species show a low transformation efficiency,making constructing random insertional mutant libraries difficult.In this study,we established a highly efficient transformation method for constructing a random insertional mutant library of Nannochloropsis oceanica,and tentatively tried to isolate its genes to prove the feasibility of the method.A gene that may control the growth rate and cell size was identified.This method will facilitate the genetic studies of N.oceanica,which should also be a reference for other microalgal species.
文摘Automatic control technology is the basis of road robot improvement,according to the characteristics of construction equipment and functions,the research will be input type perception from positioning acquisition,real-world monitoring,the process will use RTK-GNSS positional perception technology,by projecting the left side of the earth from Gauss-Krueger projection method,and then carry out the Cartesian conversion based on the characteristics of drawing;steering control system is the core of the electric drive unmanned module,on the basis of the analysis of the composition of the steering system of unmanned engineering vehicles,the steering system key components such as direction,torque sensor,drive motor and other models are established,the joint simulation model of unmanned engineering vehicles is established,the steering controller is designed using the PID method,the simulation results show that the control method can meet the construction path demand for automatic steering.The path planning will first formulate the construction area with preset values and realize the steering angle correction during driving by PID algorithm,and never realize the construction-based path planning,and the results show that the method can control the straight path within the error of 10 cm and the curve error within 20 cm.With the collaboration of various modules,the automatic construction simulation results of this robot show that the design path and control method is effective.
基金“Research on the Construction of Teaching Resource Library under the“4321”Industry-Education Integration System-Taking the Environmental Design Major as an Example”Chongqing Institute of Technology Education and Teaching Reform Research Project(Project number:JY2022308)。
文摘This paper studies and explores the construction of a teaching resource library for landscape engineering under the“4321”industry-education integration system,focusing on the construction objectives,construction paths,and construction contents,aiming to open-up the channel of school-enterprise cooperation,improve enterprise participation,and promote the reform of teaching mode and teaching methods.Establishing a practical resource library will connect and integrate students,teachers,and enterprises.A complete library of landscape-oriented teaching resources will be constructed according to the talent portraits of the industry to open-up the relationship between upstream and downstream courses,and further improve the precise fit between the cultivation of applied undergraduate talents and enterprises.
基金supported by the National Natural Science Foundation of China(41871184)the National Social Science Fund of China(21ZDA056)the Scientific and Technological Innovation Project of the Chinese Academy of Agricultural Sciences(10-IAED-ZT-01-2023and 10-IAED-RC-07-2023)。
文摘Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.
文摘To achieve accurate classification and recognition of ship target types,it is necessary to establish a sample library of ship targets to be identified.On the basis of exploring the principles of building a ship target image library,the paper determines the sample set.Using 3DS MAX software as the platform,combined with the accurate 3D model of the ship in an offline state,the software fully utilizes its own rendering and animation functions to achieve the automatic generation of multi-view and multi-scale views of ship targets.To reduce the storage capacity of the image database,a construction method of the ship target image database based on the AP algorithm is presented.The algorithm can obtain the optimal cluster number,reduce the data storage capacity of the image database,and save the calculation amount for the subsequent matching calculation.
基金Humanities and Social Sciences Planning Fund Project of the Ministry of Education of P.R.China,titled“Research on the Books Publishing of Modern Chinese Libraries from the Perspective of Generalized Technology”(Project No.19YJA870014).
文摘The paper is based on literature search,introducing and analyzing the book publishing situation of modern Peking University Library from the perspective of the publisher being Peking University Library and its predecessor.It is pointed out that the majority of the book printing methods published by the modern Peking University Library are lead printing,and among the types of Chinese library classification,catalogue of library collections is the most common.
基金supported by a grant from the National Natural Science Foundations of China(No.52171282)supported by Taishan Scholars Program of Shandong Province,China(No.tsqn202306098)the Shandong Provincial Key Research and Development Plan,China(No.2021ZLGX04).
文摘Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between marine clay and structural materials with different roughness was studied in this paper by using 3D optical scanning tests,a modified direct shear device and numerical simulation.Relationships between the surface roughness of structures,water content and interface friction angle were presented by model tests.The increase of water contents decreased the interface friction angles.For interfaces with different roughness,the interface friction angles will be smaller than that of the soil when the water content exceeds a certain value.The roughness of the interface and the water content of the soil are mutually coupled to influence the coefficient of friction(COF).This paper proposed a Finite Element Method(FEM)to simulate the interface direct shear tests of structures with different roughness.The surface models with different roughness are established based on the structure data obtained by 3D scanning.The Coupled Eulerian-Lagrangian(CEL)approach was employed to analyse soils sheared by irregular surfaces.The interface behavior for interfaces with different roughness under cyclic shear stresses was analyzed by FEM.
文摘Taking the changes of construction land in Wan’an County over the years as the research object,the quantity and spatial characteristics of construction land in Wan’an County were analyzed,and the overall situation and regional differences of construction land utilization in Wan’an County were revealed.From the aspects of main influencing factors such as land use structure,land use intensity,land input intensity and output benefit,an evaluation indicator system was established to evaluate the economical and intensive use level of construction land in Wan’an County.The results show that the score of the economical and intensive use level of construction land in Wan’an County was 56.92,which was the lowest among all the districts and counties in Ji’an City.Based on the evaluation results,the corresponding economizing and intensive strategies were put forward,and the safeguard measures for its implementation were explored.The purpose is to provide some support for the preparation of territorial spatial planning,the delineation of urban development boundaries,and the potential exploitation of construction land stock,hoping to improve the utilization efficiency and benefit of construction land in Wan’an County,and promote the economic growth of Wan’an County to the stage of high-quality development.
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Cochin Port is an all-weather port situated within a protected natural harbour,just 11 km away from mainland shipping route.Total draft of 15m-16m is available and it is a natural choice for setting up transhipment hub.The International Container Transhipment Terminal(ICTT)at Vallarpadam was developed by DP World and M/s Cochin Port Trust(CPT).As a part of this project,the new Rail connectivity from ICTT at Vallarpadam to Idappalli station is 8.60km,including the construction of 4.62 km elevated bridge was awarded to AFCONS by M/s Rail Vikas Nigam Limited(RVNL),in 2007 with a scheduled completion by 2009.This bridge is constructed for single railway track and piling was done for the provision of a second railway track in future.The 4.62 km long bridge was successfully completed and Trial Loco run was done in March 2010.This paper includes details of sub-surface profile,engineering properties of soils,details of construction of pile foundations and Challenges faced during construction.
文摘This paper describes and provides a critique of the design and implementation of the“scoops”-a set of bespoke multifunctioning architectural free-form elements that are a highlight of the new Soheil Abedian School of Architecture at Bond University,Australia,by the office of Sir Peter Cook and Gavin Robotham,CRAB(Cook Robotham Architecture Bureau,London).The development includes the transfer of analogue design processes into digital 3d modeling,which is then analyzed and rationalized via an exchange with consultants and procurement contractors.The complexity of the concrete works necessitated the use of digital fabrication to make their implementation affordable and within time constraints,with said complexity creating a variety of challenges for many aspects of the entire delivery team.The 3d model played a critical role in communicating intent and accuracy at all stages.The use of site-based craftsmanship combined with computer aided design and fabrication overlapped to realize the project.
