In order to solve the problem of imbalance development in the maintenance of new types of rural roads,based on the technical condition of rural road pavements,the rate of good pavements based on the pavement technical condition index is selected as the evaluation index of the level of technical condition of pavements,and 1,607 counties(cities,districts and banners)in non-policy-supported areas of 2,717 county-level administrative units with rural road management and maintenance tasks nationwide are taken as samples to analyze the technical condition of the pavements in the rural road pavements in the regions which are not supported by the policy.The technical condition of rural road pavements in regions that have not received policy support is analyzed.The results of the study show that the overall technical condition of pavements in non-policy-supporting regions is higher than the average level of the whole country and policy-supporting regions.The 30 non-policy-supported counties(cities and districts)in the Eastern region,109 non-policy-supported counties(cities and districts)in the Central region,and 108 non-policy-supported counties(cities,districts and banners)in the Western region are lower than the average level in the Western region.The problem of backwardness of pavement technical condition occurs in non-policy support areas.It is recommended that the non-policy-supported counties(cities,districts and banners)with low rates of good roads and backward pavement technology should conduct field research on the technical condition of their rural road pavements,and adjust the strength of their policy support.
This paper points out that the traction power supply system of high-speed railway is a special power system composed of traction substations, traction network and electric locomotives. In order to study the traction power supply system of high-speed railway, this paper selects the appropriate modules in the alternative transients program –electromagnetic transient program（ATP-EMTP） to build the simulation models of each component of the traction power supply system, and verifies the accuracy of the model through the simulation experiment, providing a certain reference basis for the design, repair and maintenance of high-speed railway.
In this study,the third generation sequencing is used to sequencing of the full length transcriptome library and obtain the FGF gene sequence.PCR primer is design according the sequence.The PCR product is directly sequenced to verify the gene sequence,and the full length of the FGF gene is 787 bp.The ORF length of the FGF gene is 699 bp,encoding a total of 232 amino acids.The results of nucleic acid sequence homology analysis shows that it shares 99.50%homology with Cyplinus carpio FGF13 gene,and has high homology and close genetic relationships with the corresponding FGF genes of Sinocyclochei-lus grahami,Cyprinus carpio,Cara-ssius auratus,and Danio rerio;further comparison revealed 99.01%homology with the amino acid sequence of the FGF13a-2 gene,indicating that the gene is the FGF13a-2 gene of Schizothorax grahami.The structural domain prediction includes receptor binding sites and heparin binding sites,and the FGF gene encodes proteins in the secondary structure,the proportion of α-spiral is 22.41%,the proportion of β-corners is 8.19%,the proportion of extended chains is 21.55%,and the proportion of random curls is 47.84%,having the characteristics of FGF protein transcription factor superfamily.
The"dual mentor system"project in Shaanxi Province is a new mechanism established by the Shaanxi Provincial Department of Science and Technology in basic research technology projects.This paper reviews the domestic and foreign literature on the performance evaluation of the"dual mentor system"project in Shaanxi Province,especially basic research projects,with a focus on elaborating on the research process and evaluation methods.The analysis found that the specific research on the performance evaluation methods of the"dual mentor system"project in the field of basic research is still relatively weak,and the evaluation methods are not diversified enough;in terms of the design and application of performance evaluation indicators,there is a majority of theoretical exploration,and there is less practice in combining basic research with sci-tech project cases.This will be a direction for future research.
In view of the difficulties in construction,high requirements for stability and durability of super-large bridges and cross-embankment bridges,and based on the hydrogeological characteristics of the Yellow River super-large cross-embankment bridge on Puyang-Yangxin Expressway,two schemes of prestressed concrete continuous beams and prestressed concrete composite beams with corrugated steel webs are designed.The comparative analysis on the maintenance amount in the later period shows that the combination of concrete and steel materials in the prestressed concrete beam bridge with corrugated steel webs can significantly reduce the risk of web cracking and midspan deflection of long-span concrete beam bridges,reduce the dead weight of the bridge by 15%,reduce the seismic force,reduce the cost and shorten the construction period.However,the construction technology is complex,the requirements for construction control and quality are very high,the later maintenance is difficult,the maintenance cost is high,and the construction technology is not mature.The gap between the two design schemes mainly lies in the structural rationality,construction period and project cost,construction difficulty,and later maintenance.After comprehensive consideration of relevant factors,the prestressed concrete continuous beam design scheme should be selected for the Yellow River super-large cross-embankment bridge on Puyang-Yangxin Expressway.However,it is necessary to deal with the midspan downwarping and structural anti-seismic problems.At the beam end and tower end,traction tensioning equipment to eliminate cracks,twist or limit twist should be used to improve the construction quality and safety of stay cables.
A sample of 55.0° to 87.5° hammer marks is made with a self-made sample preparation instrument for hammer marks.After collecting the marks with a three-dimensional surface measuring instrument,the characteristics with strong correlation with the strike angle are measured.Based on the method of regression analysis,the mathematical models for inferring the strike angle from the trace characteristics are obtained.The characteristic angle and the strike angle have a linear relationship of y=0.885 5x+103.42,and the maximum deviation between the calculated result and the actual angle is not more than 2.20%,which is reliable.The characteristics referenced by the depth group and width group models are greatly affected by the change of the strike speed,so the accuracy of the models is relatively low,with the average deviation of about 9.24%and 7.03%respectively.
One of the key requirements for the development of large-scale satellite antenna technology is to prepare support structures with high storage ratio and excellent dynamic performance that can be reliably retracted.this paper proposes an improvement plan for the support structure of the circular antenna reflector,and designs the joint structure of the support truss to make it suitable for various unit cell numbers,providing convenience for ground dynamics experiments of the circular antenna support truss.Firstly,three-dimensional modeling and motion simulation are conducted on the support truss to verify the feasibility of the scheme;then,physical models of the deployable truss are developed;finally,support structure deployment experiments are conducted to verify the feasibility of the design of the deployable support truss structure.
Shuikoushan Pb-Zn Mining Area is rich in mineral resources and has a long mining history.There are series of mine geo-environmental problems caused by the mine exploitation,which are against the policy of the ecological civilization construction,so it is urgent to carry out comprehensive ecological environment restoration work.The paper analyzes and elaborates on the main geological and environmental problems in the Shuikoushan mining area,guided by the concept of"harmonious coexistence between humans and nature"and following the principle of"adapting measures to local conditions and classified governance",ecological restorations are carried out including mining environment protection and governance,comprehensive utilization of resources and pollution prevention and control,land reclamation and geological disaster prevention and control,waste management and recycling utilization.It can provide important reference for ecological restoration work in similar mining concentrated mining areas.
The 330 kV central substation supporting cable tunnel(Hongmiaopo Road-West Section of Second Ring North Road)project relied on in this paper mainly passes through fine and medium sand formations,causing significant wear and tear on the shield machine cutterhead.In addition,the tight construction period and heavy tasks make it difficult to acquire land for the construction of intermediate wells.In order to solve the above difficulties,optimization and transformation are carried out based on the previous cutterhead design form in the same area,greatly enhancing the wear resistance of the cutterhead,Not only does it avoid the idle and waste of old shield tunneling machines,but also improves construction efficiency and saves engineering construction costs.During the shield construction process,measures are taken to reinforce adjacent subways and buildings,and key construction technologies such as measurement of initial attitude of shield tunneling machines,surface grouting reinforcement,cutterhead transformation,shield starting and shield receiving are adopted,effectively reducing safety risks and ensuring the smooth progress of the 330 kV substation supporting shield cable tunnel,which is recognized and praised by the owner.The research content of this paper can provide reference for the construction of similar projects in the future.
With the development of the times,building information modeling(BIM)has become an important component of urban rail transit construction.Its emergence provides strong support for the sustainability,safety,reliability,operability,and other aspects of urban rail transit,making the construction of urban rail transit more efficient and sustainable.This paper takes BIM modeling for urban rail transit as the research object,on the basis of exploring BIM modeling standards,it analyzes the expression of BIM at different stages,and discusses the value of BIM application in urban rail transit engineering construction using a certain engineering example,aiming to bring more ideas and inspirations for improving the level of BIM application in other urban rail transit constructions in China.
As an important gateway for the opening up of Northeast China,the central and southern Liaoning urban agglomeration is of great significance in accelerating the construction of a new development pattern of"dual circulation",deeply integrating into the Belt and Road Initiative,and making new breakthroughs in the comprehensive revitalization of Northeast China.Taking the central and southern Liaoning urban agglomeration as the research object,this paper analyzes the industrial structure and its influencing factors within the region,and puts forward countermeasures and suggestions for the industrial collaborative development path of the central and southern Liaoning urban agglomeration combined with regional characteristics:taking the economic"dual circulation"as an opportunity to deeply integrate into the global value chain;strengthening industrial division of labor and cooperation,and achieving resource integration within the region;coordinating spatial planning and strengthening the construction of regional public resource factor markets;promoting green and low-carbon development,and forming a new pattern of ecological friendly industrial development.
In order to explore whether original keys that have never been used will form traces inside the lock cylinder,investigate the reasons for the formation of such traces,and compare the differences between the characteristics of the copied key traces,this paper takes such experimental research:taking several marble locks,simulating daily shape marks,and then using new original keys and copied keys to open them respectively,disassembling the locks,observing and comparing the characteristics of the marks.The experimental results show that the new original key can form marks on the marble,which have certain differences from the copied key's marks.It is concluded that special marks on round headed bullets should be considered whether they are formed by the new original key.
This paper introduces the concept,principle,mode formulas and categories,and main materials of wireless charging technology,analyzes the main problems,discusses short-term solutions,and looks forward to the future of this technology.Wireless charging is the contactless transmission of power energy to electrical equipment without wires.Wireless charging technology mainly includes electromagnetic induction and magnetic resonance.The electromagnetic induction formula is to make the conductor produce electromotive force in the changing magnetic flux,so as to realize the mutual transformation of electricity and magnetism.Magnetic resonance creates a changing magnetic field through the transmitting coil,and the receiving coil converts it into electrical energy.The main materials used in wireless charging are soft magnetic ferrite,neodymium iron boron permanent magnet,copper and so on.Charging efficiency and electromagnetic radiation safety are the main problems encountered in wireless charging.Some problems have short-term solutions.With the popularity of mobile power consumption equipments,the demand for wireless charging will be increasing,and the technology application prospect will be broad.
In view of the complexity and uncertainty of the influencing factors of coal mine roof disaster accidents,starting from the factors of production safety,supply safety,resource geological safety and ecological safety of the coal mining industry,considering safety quality,operation ability,physiological and psychological factors,personnel into the roof falling area,monitoring and forecasting system,roof crushing degree,supporting strength,geological structure,coal properties,sudden natural disasters,"three violations"behavior,supervision and management system,safety education and training and other coal mine roof disaster accident influencing factors,AHP model for the influencing factors of coal mine roof disaster accidents is building.The safety evaluation of the roof accident of a mine in Guizhou is taking by using AHP,according to the weight ranking of safety evaluation index,the relevant measures of the coal mine roof disaster prevention and control are proposed.The results show that it is feasible to evaluate and analyze the influencing factors of coal mine roof disaster,and it is of great significance to promote the prevention and control of coal mine roof disaster accidents.
During the growth process of trees,root diseases and pests are prone to occur during the seedling stage,causing partial decay of the seedling roots and rhizomes,and even the entire plant to wither and die.In order to solve the above problems,this paper designs a disease and pest control device for forest planting that integrates liquid injection,automatic irrigation and intelligent monitoring of soil information.The device includes a liquid injection system,pipeline system structure and intelligent monitoring system.The device has the characteristics of reducing liquid waste,reducing the daily irrigation intensity of growers,and reducing the threat of root diseases and pests.
Using the Derwent Innovation Index as the data source and the patent intelligence analysis method,this paper analyzes the patent data of the CNC machine tool industry in Shaanxi Province.Reveal the development and changes of the CNC machine tool industry from the perspectives of patent geographical distribution,patent applicant organization distribution and industry core,and hot technology distribution,providing reliable reference for comprehensively grasping the technological innovation trend and innovation development of the CNC machine tool industry.
The core of sci-tech competition is talent competition,and a sound policy for sci-tech talents is an important guarantee for enhancing sci-tech competitiveness.This paper is based on a policy research perspective,firstly,a comparative study is conducted on the sci-tech talent policies of sub-provincial cities in China from three dimensions:policy objectives,talent qualifications,and evaluation models,and the differences and similarities in the content of sci-tech talent policies in different regions are distinguished;secondly,an analysis is conducted on the current situation of sci-tech talent policies in Guangzhou from the perspective of policy background,application qualifications,and evaluation methods.Research has identified the problems in Guangzhou's sci-tech talent policy,and proposed clear policy recommendations to provide decision-making reference for Guangzhou to further formulate and improve sci-tech talent policies.
By analyzing the problems faced by talent cultivation in robot engineering specialty,aiming at the talent cultivation objectives and educational philosophy of application-oriented undergraduate colleges,based on the outcome-based education(OBE)model,this paper explores a new innovative cultivation system for cultivating application-oriented high-quality talents,to boost students'motivation and effect in learning,while also to enhance their comprehensive practical and innovative skills.This innovative approach is anticipated to offer superior educational patterns and techniques to cultivate exceptional application-oriented high-quality talents.
In order to improve the level of forest safety protection and the efficiency of ecological research,a wireless monitoring system based on single-chip microcomputer control is designed and applied,including a fixed ground monitoring platform and a drone cruise platform.According to the functional requirements and design principles of the wireless monitoring system,key hardwares are selected and designed,a wireless communication scheme and software control process are established,and the anti-interference ability of the system is improved through relevant hardware circuits.The cruise monitoring nodes are reasonably arranged and the data control scheme is optimized.The system is stable,reliable,cost-effective,and can achieve good economic and social benefits.
In response to practical problems encountered in the production of remote sensing image interpretation samples,such as the lack of intuitive display of achievement data in the database and low utilization value of data resources,this paper discusses and studies a new method for constructing a remote sensing image interpretation sample database.By collecting and registering remote sensing image interpretation sample data,designing the structure of the remote sensing image interpretation sample database,building the sample data database,and updating the sample database,database construction is achieved,so as to provide assistance in determining the accuracy of the interpretation results and to accumulate on-site reference materials for geographical and national monitoring.
