The county economy serves as the fundamental unit in China’s economic development and construction.There exists a significant correlation between the quality and level of county economic development and the overall e...The county economy serves as the fundamental unit in China’s economic development and construction.There exists a significant correlation between the quality and level of county economic development and the overall economic construction level of the country.In recent years,China’s economy has experienced rapid growth,contributing to an improved living environment and substantial economic income for its citizens.However,this progress has also brought to light certain issues,such as an unbalanced industrial structure and inefficient resource utilization,leading to problems such as low efficiency and severe environmental pollution.Therefore,it becomes imperative to enhance the statistical monitoring and evaluation of high-quality county economic development.This approach aims to gather insights into the development status of the county economy and provide essential data support for decision-making in county economic development.Consequently,this paper proposes development suggestions for the statistical monitoring and evaluation of high-quality county economic development,serving as a crucial starting point for future initiatives.展开更多
Bridge engineering is an important part of basic engineering in today’s transportation field,and its quality and performance have a vital impact on the improvement and development of modern transportation engineering...Bridge engineering is an important part of basic engineering in today’s transportation field,and its quality and performance have a vital impact on the improvement and development of modern transportation engineering.With the continuous development of transportation engineering,the maintenance and reinforcement of existing bridges are also being given more emphasis.In order to scientifically evaluate the effectiveness of bridge maintenance and reinforcement,this paper analyzes its detection and evaluation,including the significance,key points,and main methods of detection and evaluation.Therefore,this analysis aim to provide some reference for the maintenance and reinforcement and the quality improvement of bridge engineering.展开更多
In order to meet the demand of testability analysis and evaluation for complex equipment under a small sample test in the equipment life cycle, the hierarchical hybrid testability model- ing and evaluation method (HH...In order to meet the demand of testability analysis and evaluation for complex equipment under a small sample test in the equipment life cycle, the hierarchical hybrid testability model- ing and evaluation method (HHTME), which combines the testabi- lity structure model (TSM) with the testability Bayesian networks model (TBNM), is presented. Firstly, the testability network topo- logy of complex equipment is built by using the hierarchical hybrid testability modeling method. Secondly, the prior conditional prob- ability distribution between network nodes is determined through expert experience. Then the Bayesian method is used to update the conditional probability distribution, according to history test information, virtual simulation information and similar product in- formation. Finally, the learned hierarchical hybrid testability model (HHTM) is used to estimate the testability of equipment. Compared with the results of other modeling methods, the relative deviation of the HHTM is only 0.52%, and the evaluation result is the most accu rate.展开更多
This paper presents an overview of petrophysical research and exploration achievements of low resistivity pay (LRP) zone by well logs in China. It includes geological characteristics and characteristics of well log ...This paper presents an overview of petrophysical research and exploration achievements of low resistivity pay (LRP) zone by well logs in China. It includes geological characteristics and characteristics of well log response of the low resistivity pay zones discovered and evaluated in recent years, as well as the problems in recognizing and evaluating low resistivity pay zones by well logs. The research areas mainly include the Neogene formations in the Bohai Bay Basin, the Triassic formations in the northern Tarim Basin and the Cretaceous formations in the Junggar Basin, The petrophysical research concerning recognition and evaluation of the low resistivity pays, based on their genetic types, is introduced in this paper.展开更多
Spine-related disorders are caused by several factors including (1) spinal nerve/visceral nerve stimulation by perivertebral aseptic inflammation, (2) spinal nerve/visceral nerve compression by injured periverterb...Spine-related disorders are caused by several factors including (1) spinal nerve/visceral nerve stimulation by perivertebral aseptic inflammation, (2) spinal nerve/visceral nerve compression by injured periverterbal soft tissue, dislocated perivertebral small joint, and proliferative/degenerative tissue and, (3) secondary damage to the spinal cord, peripheral nerve, vessels and autonomic nerve, which further stimulate nerve root sheath and surround- ing pain-carrying nerve fibers. In many cases, the source of pain cannot be detected by standard image modalities. Particularly in anatomically complex regions like the spine, SPECT/CT can be helpful for some aspects by intro- ducing a metabolical dimension to the classical way of morphology-based diagnostic. The aim of the present review was to give an overview of the adoption of SPECT/CT in a clinical spine-focused setting.展开更多
Using actual precipitation in Shaoyang of 2018-2020,precipitation forecast of ECMWF model was tested.The results showed that winter accuracy rate was the highest,followed by autumn,and summer accuracy rate was the low...Using actual precipitation in Shaoyang of 2018-2020,precipitation forecast of ECMWF model was tested.The results showed that winter accuracy rate was the highest,followed by autumn,and summer accuracy rate was the lowest.24-h TS scoring results showed that the shorter the cumulative time,the lower the TS.Forecasters had a strong ability to predict summer rainstorms.展开更多
A smart fully mechanized coal mining working face is comprised of various heterogeneous equipment that work together in unknown coal seam environments.The goal is to form a smart operational system with comprehensive ...A smart fully mechanized coal mining working face is comprised of various heterogeneous equipment that work together in unknown coal seam environments.The goal is to form a smart operational system with comprehensive perception,decisionmaking,and control.This involves many work points and complex coupling relationships,indicating it needs to be performed in stages and coordinated to address key problems in all directions and along multiple points.However,there are no existing unifed test or analysis tools.Therefore,this study proposed a virtual test and evaluation method for a fully mechanized mining production system with diferent smart levels.This is based on the concept of“real data processing–virtual scene construction–setting key information points–virtual operation and evaluation.”The actual operational data for a specifc working face geology and equipment were reasonably transformed into a visual virtual scene through a movement relationship model.The virtual operations and mining conditions of the working face were accurately reproduced.Based on the sensor and execution error analyses for diferent smart levels,the input interface for sensing,decision-making,and control was established for each piece of equipment,and an operation evaluation system was constructed.The system comprehensively simulates and tests the key points of sensing decision-making and control with various smart levels.The experimental results showed that the virtual scene constructed based on actual operational data has a high simulation degree.Users can simulate,analyze,and evaluate the overall operations of the smart mining 2.0–4.0 working face by inputting key information.The future direction for the smart development of fully mechanized mining is highlighted.展开更多
Introduction The use of supercritical fluids such as supercritical CO<sub>2</sub>(scCO<sub>2</sub>) has provided a ’clean’ and effective alternative to traditional methods of protein delive...Introduction The use of supercritical fluids such as supercritical CO<sub>2</sub>(scCO<sub>2</sub>) has provided a ’clean’ and effective alternative to traditional methods of protein delivery systems.Here。展开更多
Meteorological disasters usually exert huge impacts on the development of both human society and the economy. According to statistics from the United Nations International Strategy for Disaster Reduction, the annual m...Meteorological disasters usually exert huge impacts on the development of both human society and the economy. According to statistics from the United Nations International Strategy for Disaster Reduction, the annual mean economic loss caused by meteorological disasters accounts for 3%-6% of the total amount of global GDP. China is a country that has been one of the most severely influenced by natural disasters.展开更多
The 300 msw Simulated Saturation Diving Chamber Complex was designed and built by ourselves. It was completed at the end of 1985. A 300 msw trimixed saturation diving experiment was successfully conducted in the compl...The 300 msw Simulated Saturation Diving Chamber Complex was designed and built by ourselves. It was completed at the end of 1985. A 300 msw trimixed saturation diving experiment was successfully conducted in the complex by Chinese Underwater Technology Institute(CUTI) from May 22 to June 12 of 1987. During the experiment, 4 divers habitated in the complex for 20 days, and they performed 16 person-time excursion dives and 8 other tests. The result of the experiment indicates that the complex is well designed, suitably configurated, wholly integrated and steadily run, as well as of low leakage. The main functions of the complex have approached to those of the same kind in the world. The complex can be used as a basic facility for serving the nation's saturation diving technology, underwater operation, personnel training, etc.展开更多
A differential accelerometer comprising of two rotating masses made of the same material is proposed for drop tower-based free-fall testing of the spin-spin force between the rotating mass and the Earth. The measureme...A differential accelerometer comprising of two rotating masses made of the same material is proposed for drop tower-based free-fall testing of the spin-spin force between the rotating mass and the Earth. The measurement is performed by placing the two concentric masses of very different momenta in a vacuum drop capsule which is falling freely in the Earth's gravitational field. A nonzero output of the differential aeeelerometer is an indication of possible violation of new equivalence principle (NEP). We present the conceptual design of a modified free-fall NEP experiment which can be performed at the Belting drop tower. Design and evaluation of the differential accelerometer with a hybrid electrostatic/magnetic suspension system are presented to accommodate for operation on ground and drop-tower tests. Details specific to the measurement uncertainty are discussed to yield an NEP test accuracy of 7.2×10^-9.展开更多
[Objective] The research aimed to monitor and evaluate indoor radon concentration in one district of Xi'an City. r Method] In order to master the effective dose per year caused by natural radiation to local residents...[Objective] The research aimed to monitor and evaluate indoor radon concentration in one district of Xi'an City. r Method] In order to master the effective dose per year caused by natural radiation to local residents, the investigation about the level of indoor radon in one district of Xi'an was developed. Based on the proper monitoring scheme, some typical living rooms were sampled. Through the measurement result, the effects of different factors on radon concentration were obtained. Finally, the radon concentration was transferred into the effective dose per year of local residents. [ Result] Indoor radon concentration in the district was during 49.680 -128.856 Bq/m3, and average concentration in each building was within 100 Bq/m3, which belonged to normal range. When sunny day became rainy day, radon concentration firstly had a rise trend. If continuous rainy weather appeared, indoor radon concentration gradually declined. When other conditions were same, indoor radon concentration under window closing was significantly higher than that under window opening. Indoor radon concentration had a decline trend from 13:00 to 20:00 and a rise trend from 01:00 to 06:00. Condusion The district belonged to radon safety house. To protect residents' health to the maximum extent, according to transfer change rule of the radon, window should be opened to ventilate in the morning when radon concentration was higher.展开更多
Town Planning Board of Zhaoqing passed the Planning and Design of Xiawan Urban Wetland Park in Zhaoqing City in 2012,and Xiawan Reservoir,located at the junction of Duanzhou District and Dinghu District,would be built...Town Planning Board of Zhaoqing passed the Planning and Design of Xiawan Urban Wetland Park in Zhaoqing City in 2012,and Xiawan Reservoir,located at the junction of Duanzhou District and Dinghu District,would be built into a wetland park at that time.To understand water quality status near the wetland park,according to relevant requirements of the Technical Guidelines for Environmental Impact Assessment:Surface Water Environment(HJ/T 2.3-93),the Environmental Quality Standards for Surface Water(GB 3838-2002),and the Technical Specification for Environmental Monitoring issued by the State Environmental Protection Administration,Xiawan Reservoir,Houlichong and the Xijiang River were investigated,monitored and evaluated.展开更多
The project of returning farmland to forest has been implemented and consolidated in Henan Province for 20 years.At present,it is in a critical transition period when the previous round of project of returning farmlan...The project of returning farmland to forest has been implemented and consolidated in Henan Province for 20 years.At present,it is in a critical transition period when the previous round of project of returning farmland to forests has completed and a new round of project of returning farmland to forests has started.Henan Province took counties(cities)with different representations as sample counties for monitoring the benefits of project of returning farmland to forests(key monitoring areas in Henan Province),and monitored social and ecological benefits every year,and has obtained real and scientific monitoring data.展开更多
Reliable transport of Campylobocter jejuni isolates is critical to microbial epidemiology research, especially in developing countries without a good temperature control mailing system. Various factors, including oxyg...Reliable transport of Campylobocter jejuni isolates is critical to microbial epidemiology research, especially in developing countries without a good temperature control mailing system. Various factors, including oxygen, temperature, transport medium composition, could affect the survival of C jejunL In this study, the protective effects of different ingredients in C. jejuni transport media at 4 ℃ and 25 ℃ and under aerobic condition were quantitatively evaluated respectively. The results showed that enriched medium, supplementation with 5% blood and being kept at 4 ℃ could improve the viability of different C. jejuni strains during transport. In addition, supplementation with 25 mmol/L L-fucose in Wang's transport medium could significantly improve the survival of C.展开更多
The use of terahertz time-domain spectroscopy(THz-TDS)for the nondestructive testing and evaluation(NDT&E)of materials and structural systems has attracted significant attention over the past two decades due to it...The use of terahertz time-domain spectroscopy(THz-TDS)for the nondestructive testing and evaluation(NDT&E)of materials and structural systems has attracted significant attention over the past two decades due to its superior spatial resolution and capabilities of detecting and characterizing defects and structural damage in non-conducting materials.In this study,the THz-TDS system is used to detect,localize and evaluate hidden multi-delamination defects(i.e.,a three-level multi-delamination system)in multilayered GFRP composite laminates.To obtain accurate results,a wavelet shrinkage de-noising algorithm is used to remove the noise from the measured time-of-flight(TOF)signals.The thickness and location of each delamination defect in the z-direction(i.e.,through-the-thickness direction)are calculated from the de-noised TOF signals considering the interaction between the pulsed THz waves and the different interfaces in the GFRP composite laminates.A comparison between the actual and the measured thickness values of the delamination defects before and after the wavelet shrinkage denoising process indicates that the latter provides better results with less than 3.712%relative error,while the relative error of the non-de-noised signals reaches 16.388%.Also,the power and absorbance levels of the THz waves at every interface with different refractive indices in the GFRP composite laminates are evaluated based on analytical and experimental approaches.The present study provides an adequate theoretical analysis that could help NDT&E specialists to estimate the maximum thickness of GFRP composite materials and/or structures with different interfaces that can be evaluated by the THz-TDS.Also,the accuracy of the obtained results highlights the capabilities of the THz-TDS for the NDT&E of multilayered GFRP composite laminates.展开更多
With the development of central-private enterprises integration,selecting suitable key suppliers are able to provide core components for smart complex equipment.We consider selecting suitable key suppliers from matchi...With the development of central-private enterprises integration,selecting suitable key suppliers are able to provide core components for smart complex equipment.We consider selecting suitable key suppliers from matching perspective,for it not only satisfies natural development of smart complex equipment,it is also a good implementation of equipment project in central-private enterprises integration context.In in this paper,we carry out two parts of research,one is evaluation attributes based on comprehensive analysis,and the other is matching process between key suppliers and core components based on the matching attribute.In practical analysis process,we employ comprehensive evaluated analysis methods to acquire relevant attributes for the matching process that follows.In the analysis process,we adopt entropy-maximum deviation method(MDM)-decision-making trial and evaluation laboratory(DEMATEL)-technique for order preference by similarity to an ideal solution(TOPSIS)to obtain a comprehensive analysis.The entropy-MDM is applied to get weight value,DEMATEL is utilized to obtain internal relations,and TOPSIS is adopted to get ideal evaluated solution.We consider aggregating two types of evaluation information according to similarities of smart complex equipment based on the combination between geometric mean and arithmetic mean.Moreover,based on the aforementioned attributes and generalized power Heronian mean operator,we aggregate preference information to acquire relevant satisfaction degree,then combine the constructed matching model to get suitable key supplier.Through comprehensive analysis of selecting suitable suppliers,we know that two-sided matching and information aggregation can provide more research perspectives for smart complex equipment.Through analysis for relevant factors,we find that leading role and service level are also significant for the smart complex equipment development process.展开更多
Comprehensive research methods such as literature research,theoretical analysis,numerical simulations and field monitoring have been used to analyze the disasters and characteristics caused by the linkage failure and ...Comprehensive research methods such as literature research,theoretical analysis,numerical simulations and field monitoring have been used to analyze the disasters and characteristics caused by the linkage failure and instability of the residual coal pillars-rock strata in multi-seam mining.The effective monitoring area and monitoring design method of linkage instability of residual coal pillar-rock strata in multi-seam mining have been identified.The evaluation index and the risk assessment method of disaster risk have been established and the project cases have been applied and validated.The results show that:①The coal pillar will not only cause disaster in singleseam mining,but also more easily cause disaster in multi-seam mining.The instability of coal pillars can cause not only dynamical disasters such as rock falls and mine earthquakes,but also cause surface subsidence and other disasters.②When monitoring the linkage instability of residual coal pillar-rock strata,it is not only necessary to consider the monitoring of the apply load body(key block),the transition body(residual coal pillar)and the carrier body(interlayer rock and working face),but also to strengthen the monitoring of the fracture development height(linkage body).③According to the principles of objectivity,easy access and quantification,combined with investigation,analysis,and production and geological characteristics of this mining area,the main evaluation indexes of the degree of disaster caused by linkage instability of residual coal pillar-rock strata are determined as:microseismic energy,residual coal pillar damage degree,fracture development height.And the evaluation index classification table was also given.④According to the measured value of the evaluation index,the fuzzy comprehensive evaluation method was used to calculate the disaster risk degree in the studied mine belongs to class III,that is,medium risk level.The corresponding pressure relief technology was adopted on site,which achieved a good control effect,and also verified the accuracy and effectiveness of the risk evaluation results.展开更多
Objective: To systematically review the clinical practice guidelines (CPGs) for ischemic stroke in Chinese medicine (CM) with the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument. Meth...Objective: To systematically review the clinical practice guidelines (CPGs) for ischemic stroke in Chinese medicine (CM) with the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument. Methods: CM CPGs for ischemic stroke were searched in 5 online databases and hand-searches in CPG- related handbooks published from January 1990 to December 2012. The CPGs were categorized into evidence based (EB) guideline, consensus based with no explicit consideration of evidence based (CB-EB) guideline and consensus based (CB) guideline according to the development method. Three reviewers independently appraised the CPGs based on AGREE II instrument, and compared the CPGs' recommendations on CM pattern classification and treatment. Results: Five CM CPGs for ischemic stroke were identified and included. Among them, one CPG was EB guideline, two were CB guidelines and two were CB-EB guidelines. The quality score of the EB guideline was higher than those of the CB-EB and CB guidelines. Five CM patterns in the CPGs were recommended in the EB CPG. The comprehensive protocol of integrative Chinese and Western medicine recommended in the EB CPG was mostly recommended for ischemic stroke in the CPGs. The recommendations varied based on the CM patterns. Conclusion: The quality of EB CPG was higher than those of CB and CB-EB CPGs in CM for ischemic stroke and integrative approaches were included in CPGs as major interventions.展开更多
文摘The county economy serves as the fundamental unit in China’s economic development and construction.There exists a significant correlation between the quality and level of county economic development and the overall economic construction level of the country.In recent years,China’s economy has experienced rapid growth,contributing to an improved living environment and substantial economic income for its citizens.However,this progress has also brought to light certain issues,such as an unbalanced industrial structure and inefficient resource utilization,leading to problems such as low efficiency and severe environmental pollution.Therefore,it becomes imperative to enhance the statistical monitoring and evaluation of high-quality county economic development.This approach aims to gather insights into the development status of the county economy and provide essential data support for decision-making in county economic development.Consequently,this paper proposes development suggestions for the statistical monitoring and evaluation of high-quality county economic development,serving as a crucial starting point for future initiatives.
文摘Bridge engineering is an important part of basic engineering in today’s transportation field,and its quality and performance have a vital impact on the improvement and development of modern transportation engineering.With the continuous development of transportation engineering,the maintenance and reinforcement of existing bridges are also being given more emphasis.In order to scientifically evaluate the effectiveness of bridge maintenance and reinforcement,this paper analyzes its detection and evaluation,including the significance,key points,and main methods of detection and evaluation.Therefore,this analysis aim to provide some reference for the maintenance and reinforcement and the quality improvement of bridge engineering.
基金supported by the National Defense Pre-research Foundation of China(51327030104)
文摘In order to meet the demand of testability analysis and evaluation for complex equipment under a small sample test in the equipment life cycle, the hierarchical hybrid testability model- ing and evaluation method (HHTME), which combines the testabi- lity structure model (TSM) with the testability Bayesian networks model (TBNM), is presented. Firstly, the testability network topo- logy of complex equipment is built by using the hierarchical hybrid testability modeling method. Secondly, the prior conditional prob- ability distribution between network nodes is determined through expert experience. Then the Bayesian method is used to update the conditional probability distribution, according to history test information, virtual simulation information and similar product in- formation. Finally, the learned hierarchical hybrid testability model (HHTM) is used to estimate the testability of equipment. Compared with the results of other modeling methods, the relative deviation of the HHTM is only 0.52%, and the evaluation result is the most accu rate.
基金Supported by CNPC Innovation Foundation,Research Projects of PetroChina,Xinjiang and Tarim Oil Companies
文摘This paper presents an overview of petrophysical research and exploration achievements of low resistivity pay (LRP) zone by well logs in China. It includes geological characteristics and characteristics of well log response of the low resistivity pay zones discovered and evaluated in recent years, as well as the problems in recognizing and evaluating low resistivity pay zones by well logs. The research areas mainly include the Neogene formations in the Bohai Bay Basin, the Triassic formations in the northern Tarim Basin and the Cretaceous formations in the Junggar Basin, The petrophysical research concerning recognition and evaluation of the low resistivity pays, based on their genetic types, is introduced in this paper.
文摘Spine-related disorders are caused by several factors including (1) spinal nerve/visceral nerve stimulation by perivertebral aseptic inflammation, (2) spinal nerve/visceral nerve compression by injured periverterbal soft tissue, dislocated perivertebral small joint, and proliferative/degenerative tissue and, (3) secondary damage to the spinal cord, peripheral nerve, vessels and autonomic nerve, which further stimulate nerve root sheath and surround- ing pain-carrying nerve fibers. In many cases, the source of pain cannot be detected by standard image modalities. Particularly in anatomically complex regions like the spine, SPECT/CT can be helpful for some aspects by intro- ducing a metabolical dimension to the classical way of morphology-based diagnostic. The aim of the present review was to give an overview of the adoption of SPECT/CT in a clinical spine-focused setting.
文摘Using actual precipitation in Shaoyang of 2018-2020,precipitation forecast of ECMWF model was tested.The results showed that winter accuracy rate was the highest,followed by autumn,and summer accuracy rate was the lowest.24-h TS scoring results showed that the shorter the cumulative time,the lower the TS.Forecasters had a strong ability to predict summer rainstorms.
基金Funding National Natural Science Foundation of China,52004174Major Science and Technology Projects in Shanxi Province,202101020101021+2 种基金Fund for Shanxi“1331”ProjectKey Project of the Chinese Society of Academic Degrees and Graduate Education,2020ZDA12Natural Science Foundation of Shanxi Province,201901D211022.
文摘A smart fully mechanized coal mining working face is comprised of various heterogeneous equipment that work together in unknown coal seam environments.The goal is to form a smart operational system with comprehensive perception,decisionmaking,and control.This involves many work points and complex coupling relationships,indicating it needs to be performed in stages and coordinated to address key problems in all directions and along multiple points.However,there are no existing unifed test or analysis tools.Therefore,this study proposed a virtual test and evaluation method for a fully mechanized mining production system with diferent smart levels.This is based on the concept of“real data processing–virtual scene construction–setting key information points–virtual operation and evaluation.”The actual operational data for a specifc working face geology and equipment were reasonably transformed into a visual virtual scene through a movement relationship model.The virtual operations and mining conditions of the working face were accurately reproduced.Based on the sensor and execution error analyses for diferent smart levels,the input interface for sensing,decision-making,and control was established for each piece of equipment,and an operation evaluation system was constructed.The system comprehensively simulates and tests the key points of sensing decision-making and control with various smart levels.The experimental results showed that the virtual scene constructed based on actual operational data has a high simulation degree.Users can simulate,analyze,and evaluate the overall operations of the smart mining 2.0–4.0 working face by inputting key information.The future direction for the smart development of fully mechanized mining is highlighted.
文摘Introduction The use of supercritical fluids such as supercritical CO<sub>2</sub>(scCO<sub>2</sub>) has provided a ’clean’ and effective alternative to traditional methods of protein delivery systems.Here。
文摘Meteorological disasters usually exert huge impacts on the development of both human society and the economy. According to statistics from the United Nations International Strategy for Disaster Reduction, the annual mean economic loss caused by meteorological disasters accounts for 3%-6% of the total amount of global GDP. China is a country that has been one of the most severely influenced by natural disasters.
文摘The 300 msw Simulated Saturation Diving Chamber Complex was designed and built by ourselves. It was completed at the end of 1985. A 300 msw trimixed saturation diving experiment was successfully conducted in the complex by Chinese Underwater Technology Institute(CUTI) from May 22 to June 12 of 1987. During the experiment, 4 divers habitated in the complex for 20 days, and they performed 16 person-time excursion dives and 8 other tests. The result of the experiment indicates that the complex is well designed, suitably configurated, wholly integrated and steadily run, as well as of low leakage. The main functions of the complex have approached to those of the same kind in the world. The complex can be used as a basic facility for serving the nation's saturation diving technology, underwater operation, personnel training, etc.
基金Supported by the National Natural Science Foundation of China under Grant Nos 91436107 and 61374207
文摘A differential accelerometer comprising of two rotating masses made of the same material is proposed for drop tower-based free-fall testing of the spin-spin force between the rotating mass and the Earth. The measurement is performed by placing the two concentric masses of very different momenta in a vacuum drop capsule which is falling freely in the Earth's gravitational field. A nonzero output of the differential aeeelerometer is an indication of possible violation of new equivalence principle (NEP). We present the conceptual design of a modified free-fall NEP experiment which can be performed at the Belting drop tower. Design and evaluation of the differential accelerometer with a hybrid electrostatic/magnetic suspension system are presented to accommodate for operation on ground and drop-tower tests. Details specific to the measurement uncertainty are discussed to yield an NEP test accuracy of 7.2×10^-9.
文摘[Objective] The research aimed to monitor and evaluate indoor radon concentration in one district of Xi'an City. r Method] In order to master the effective dose per year caused by natural radiation to local residents, the investigation about the level of indoor radon in one district of Xi'an was developed. Based on the proper monitoring scheme, some typical living rooms were sampled. Through the measurement result, the effects of different factors on radon concentration were obtained. Finally, the radon concentration was transferred into the effective dose per year of local residents. [ Result] Indoor radon concentration in the district was during 49.680 -128.856 Bq/m3, and average concentration in each building was within 100 Bq/m3, which belonged to normal range. When sunny day became rainy day, radon concentration firstly had a rise trend. If continuous rainy weather appeared, indoor radon concentration gradually declined. When other conditions were same, indoor radon concentration under window closing was significantly higher than that under window opening. Indoor radon concentration had a decline trend from 13:00 to 20:00 and a rise trend from 01:00 to 06:00. Condusion The district belonged to radon safety house. To protect residents' health to the maximum extent, according to transfer change rule of the radon, window should be opened to ventilate in the morning when radon concentration was higher.
基金Supported by Characteristic Innovative Projects of Guangdong Department of Education(Natural Science)(2018KTSCX251)Guangdong Key Laboratory of Environmental Health and Resource Utilization(2020B121201014)+1 种基金Innovation and Entrepreneurship Training Program for College Students of Zhaoqing University in 2020(S202010580063)Quality Engineering and Teaching Reform Project of Zhaoqing University(zlgc 201931)。
文摘Town Planning Board of Zhaoqing passed the Planning and Design of Xiawan Urban Wetland Park in Zhaoqing City in 2012,and Xiawan Reservoir,located at the junction of Duanzhou District and Dinghu District,would be built into a wetland park at that time.To understand water quality status near the wetland park,according to relevant requirements of the Technical Guidelines for Environmental Impact Assessment:Surface Water Environment(HJ/T 2.3-93),the Environmental Quality Standards for Surface Water(GB 3838-2002),and the Technical Specification for Environmental Monitoring issued by the State Environmental Protection Administration,Xiawan Reservoir,Houlichong and the Xijiang River were investigated,monitored and evaluated.
基金Supported by China National Fund for Monitoring of Ecological Benefits of Returning Farmland to Forests(2008-2021).
文摘The project of returning farmland to forest has been implemented and consolidated in Henan Province for 20 years.At present,it is in a critical transition period when the previous round of project of returning farmland to forests has completed and a new round of project of returning farmland to forests has started.Henan Province took counties(cities)with different representations as sample counties for monitoring the benefits of project of returning farmland to forests(key monitoring areas in Henan Province),and monitored social and ecological benefits every year,and has obtained real and scientific monitoring data.
基金supported by grant(2012AA101603)from the Ministry of Science Technologygrant(2011X7)from the National Institute of Food and Drug Controlgrant(81102131)from the National Natural Science Foundation of China
文摘Reliable transport of Campylobocter jejuni isolates is critical to microbial epidemiology research, especially in developing countries without a good temperature control mailing system. Various factors, including oxygen, temperature, transport medium composition, could affect the survival of C jejunL In this study, the protective effects of different ingredients in C. jejuni transport media at 4 ℃ and 25 ℃ and under aerobic condition were quantitatively evaluated respectively. The results showed that enriched medium, supplementation with 5% blood and being kept at 4 ℃ could improve the viability of different C. jejuni strains during transport. In addition, supplementation with 25 mmol/L L-fucose in Wang's transport medium could significantly improve the survival of C.
基金National Natural Science Foundation of China(Grant Nos.52275096,52005108,52275523)Fuzhou-Xiamen-Quanzhou National Independent Innovation Demonstration Zone High-end Equipment Vibration and Noise Detection and Fault Diagnosis Collaborative Innovation Platform ProjectFujian Provincial Major Research Project(Grant No.2022HZ024005)。
文摘The use of terahertz time-domain spectroscopy(THz-TDS)for the nondestructive testing and evaluation(NDT&E)of materials and structural systems has attracted significant attention over the past two decades due to its superior spatial resolution and capabilities of detecting and characterizing defects and structural damage in non-conducting materials.In this study,the THz-TDS system is used to detect,localize and evaluate hidden multi-delamination defects(i.e.,a three-level multi-delamination system)in multilayered GFRP composite laminates.To obtain accurate results,a wavelet shrinkage de-noising algorithm is used to remove the noise from the measured time-of-flight(TOF)signals.The thickness and location of each delamination defect in the z-direction(i.e.,through-the-thickness direction)are calculated from the de-noised TOF signals considering the interaction between the pulsed THz waves and the different interfaces in the GFRP composite laminates.A comparison between the actual and the measured thickness values of the delamination defects before and after the wavelet shrinkage denoising process indicates that the latter provides better results with less than 3.712%relative error,while the relative error of the non-de-noised signals reaches 16.388%.Also,the power and absorbance levels of the THz waves at every interface with different refractive indices in the GFRP composite laminates are evaluated based on analytical and experimental approaches.The present study provides an adequate theoretical analysis that could help NDT&E specialists to estimate the maximum thickness of GFRP composite materials and/or structures with different interfaces that can be evaluated by the THz-TDS.Also,the accuracy of the obtained results highlights the capabilities of the THz-TDS for the NDT&E of multilayered GFRP composite laminates.
文摘With the development of central-private enterprises integration,selecting suitable key suppliers are able to provide core components for smart complex equipment.We consider selecting suitable key suppliers from matching perspective,for it not only satisfies natural development of smart complex equipment,it is also a good implementation of equipment project in central-private enterprises integration context.In in this paper,we carry out two parts of research,one is evaluation attributes based on comprehensive analysis,and the other is matching process between key suppliers and core components based on the matching attribute.In practical analysis process,we employ comprehensive evaluated analysis methods to acquire relevant attributes for the matching process that follows.In the analysis process,we adopt entropy-maximum deviation method(MDM)-decision-making trial and evaluation laboratory(DEMATEL)-technique for order preference by similarity to an ideal solution(TOPSIS)to obtain a comprehensive analysis.The entropy-MDM is applied to get weight value,DEMATEL is utilized to obtain internal relations,and TOPSIS is adopted to get ideal evaluated solution.We consider aggregating two types of evaluation information according to similarities of smart complex equipment based on the combination between geometric mean and arithmetic mean.Moreover,based on the aforementioned attributes and generalized power Heronian mean operator,we aggregate preference information to acquire relevant satisfaction degree,then combine the constructed matching model to get suitable key supplier.Through comprehensive analysis of selecting suitable suppliers,we know that two-sided matching and information aggregation can provide more research perspectives for smart complex equipment.Through analysis for relevant factors,we find that leading role and service level are also significant for the smart complex equipment development process.
基金the financial support by the National Natural Science Foundation of China(Nos.52304093,52074168,52079068,41941019)Shandong Province Key Research and Development Program(No.2019SDZY02)+4 种基金Shandong Taishan Scholars Climbing Program(No.tspd20210313)State Key Laboratory of Hydroscience and Engineering foundation(No.2021-KY-04)Natural Science Foundation of Shandong Province Outstanding Youth Fund project(No.ZQ2022YQ49)the Taishan Scholars Project Special Fund(No.tsqn202211150)the Anhui Engineering Research Center of Exploitation and Utilization of Closed/Abandoned Mine Resources(No.EUCMR202205).
文摘Comprehensive research methods such as literature research,theoretical analysis,numerical simulations and field monitoring have been used to analyze the disasters and characteristics caused by the linkage failure and instability of the residual coal pillars-rock strata in multi-seam mining.The effective monitoring area and monitoring design method of linkage instability of residual coal pillar-rock strata in multi-seam mining have been identified.The evaluation index and the risk assessment method of disaster risk have been established and the project cases have been applied and validated.The results show that:①The coal pillar will not only cause disaster in singleseam mining,but also more easily cause disaster in multi-seam mining.The instability of coal pillars can cause not only dynamical disasters such as rock falls and mine earthquakes,but also cause surface subsidence and other disasters.②When monitoring the linkage instability of residual coal pillar-rock strata,it is not only necessary to consider the monitoring of the apply load body(key block),the transition body(residual coal pillar)and the carrier body(interlayer rock and working face),but also to strengthen the monitoring of the fracture development height(linkage body).③According to the principles of objectivity,easy access and quantification,combined with investigation,analysis,and production and geological characteristics of this mining area,the main evaluation indexes of the degree of disaster caused by linkage instability of residual coal pillar-rock strata are determined as:microseismic energy,residual coal pillar damage degree,fracture development height.And the evaluation index classification table was also given.④According to the measured value of the evaluation index,the fuzzy comprehensive evaluation method was used to calculate the disaster risk degree in the studied mine belongs to class III,that is,medium risk level.The corresponding pressure relief technology was adopted on site,which achieved a good control effect,and also verified the accuracy and effectiveness of the risk evaluation results.
基金Supported by the projects from the State Administration of Traditional Chinese Medicine(No.ZYYS-2011[0032]-2)the China Academy of Chinese Medical Sciences(No.Z0135,Z0260,and Z0221)the Hong Kong Hospital Authority
文摘Objective: To systematically review the clinical practice guidelines (CPGs) for ischemic stroke in Chinese medicine (CM) with the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument. Methods: CM CPGs for ischemic stroke were searched in 5 online databases and hand-searches in CPG- related handbooks published from January 1990 to December 2012. The CPGs were categorized into evidence based (EB) guideline, consensus based with no explicit consideration of evidence based (CB-EB) guideline and consensus based (CB) guideline according to the development method. Three reviewers independently appraised the CPGs based on AGREE II instrument, and compared the CPGs' recommendations on CM pattern classification and treatment. Results: Five CM CPGs for ischemic stroke were identified and included. Among them, one CPG was EB guideline, two were CB guidelines and two were CB-EB guidelines. The quality score of the EB guideline was higher than those of the CB-EB and CB guidelines. Five CM patterns in the CPGs were recommended in the EB CPG. The comprehensive protocol of integrative Chinese and Western medicine recommended in the EB CPG was mostly recommended for ischemic stroke in the CPGs. The recommendations varied based on the CM patterns. Conclusion: The quality of EB CPG was higher than those of CB and CB-EB CPGs in CM for ischemic stroke and integrative approaches were included in CPGs as major interventions.