Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSP...Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.展开更多
Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)is an excellent investigation to diagnose pancreatic lesions and has shown high accuracy for its use in pathologic diagnosis.Recently,macroscopic on-site evaluat...Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)is an excellent investigation to diagnose pancreatic lesions and has shown high accuracy for its use in pathologic diagnosis.Recently,macroscopic on-site evaluation(MOSE)performed by an endoscopist was introduced as an alternative to rapid on-site cytologic evaluation to increase the diagnostic yield of EUS-FNB.The MOSE of the biopsy can estimate the adequacy of the sample directly by the macroscopic evaluation of the core tissue obtained from EUS-FNB.Isolated pancreatic tuberculosis is extremely rare and difficult to diagnose because of its non-specific signs and symptoms.Therefore,this challenging diagnosis is based on endoscopy,imaging,and the bacteriological and histological examination of tissue biopsies.This uncommon presentation of tuberculosis can be revealed as pancreatic mass mimicking cancer.EUS-FNB can be very useful in providing a valuable histopathological diagnosis.A calcified lesion with a cheesy core in MOSE must be suggestive of tuberculosis,leading to the request of the GeneXpert,which can detect Mycobacterium tuberculosis deoxyribonucleic acid and resistance to rifampicin.A decent diagnostic strategy is crucial to prevent unnecessary surgical resection and to supply conservative management with antitubercular therapy.展开更多
A“cloud-edge-end”collaborative system architecture is adopted for real-time security management of power system on-site work,and mobile edge computing equipment utilizes lightweight intelligent recognition algorithm...A“cloud-edge-end”collaborative system architecture is adopted for real-time security management of power system on-site work,and mobile edge computing equipment utilizes lightweight intelligent recognition algorithms for on-site risk assessment and alert.Owing to its lightweight and fast speed,YOLOv4-Tiny is often deployed on edge computing equipment for real-time video stream detection;however,its accuracy is relatively low.This study proposes an improved YOLOv4-Tiny algorithm based on attention mechanism and optimized training methods,achieving higher accuracy without compromising the speed.Specifically,a convolution block attention module branch is added to the backbone network to enhance the feature extraction capability and an efficient channel attention mechanism is added in the neck network to improve feature utilization.Moreover,three optimized training methods:transfer learning,mosaic data augmentation,and label smoothing are used to improve the training effect of this improved algorithm.Finally,an edge computing equipment experimental platform equipped with an NVIDIA Jetson Xavier NX chip is established and the newly developed algorithm is tested on it.According to the results,the speed of the improved YOLOv4-Tiny algorithm in detecting on-site dress code compliance datasets is 17.25 FPS,and the mean average precision(mAP)is increased from 70.89%to 85.03%.展开更多
On-site programming big data refers to the massive data generated in the process of software development with the characteristics of real-time,complexity and high-difficulty for processing.Therefore,data cleaning is e...On-site programming big data refers to the massive data generated in the process of software development with the characteristics of real-time,complexity and high-difficulty for processing.Therefore,data cleaning is essential for on-site programming big data.Duplicate data detection is an important step in data cleaning,which can save storage resources and enhance data consistency.Due to the insufficiency in traditional Sorted Neighborhood Method(SNM)and the difficulty of high-dimensional data detection,an optimized algorithm based on random forests with the dynamic and adaptive window size is proposed.The efficiency of the algorithm can be elevated by improving the method of the key-selection,reducing dimension of data set and using an adaptive variable size sliding window.Experimental results show that the improved SNM algorithm exhibits better performance and achieve higher accuracy.展开更多
According to different testing purposes, methods and available environmental conditions, the seismograph testing can be divided into laboratory and on-site testing, respectively. The testing of the seismograph's k...According to different testing purposes, methods and available environmental conditions, the seismograph testing can be divided into laboratory and on-site testing, respectively. The testing of the seismograph's key parameters and other concerning technical specifications are well described in guide documents(China Earthquake Administration, 2017). This includes seismometer sensitivity, linearity and clip levels based on the shake table test, as well as the seismometer natural period, damping constant based on electrical calibration(Wang Guangfu,1986; Ple?inger A.,1993) and instrumental self-noise collocation estimation(Holcomb L.G., 1989; Sleeman R. et al., 2006). However, with the development of seismic observation technology, many new requirements for the performance evaluation of seismographs have been put forward, and new testing items and methods have emerged.展开更多
Approximately 20% of homes nationwide use an on-site treatment system as a form of household wastewater management. However, approximately 10% to 20% of on-site treatment systems malfunction each year, many of which h...Approximately 20% of homes nationwide use an on-site treatment system as a form of household wastewater management. However, approximately 10% to 20% of on-site treatment systems malfunction each year, many of which have either failed or exceeded the soil’s long-term acceptance rate (LTAR), causing environmental and human health risks. The objective of this field study was to evaluate the effects of soil condition (e.g., wet and dry) and product architecture type [i.e., chamber, gravel-less-pipe (GLP), polystyrene-aggregate, and pipe-and-aggregate] on in-product solution storage and biomat thickness in a profile-limited soil in northwest Arkansas under increased loading rates and to estimate the LTAR for each product. During Phase I of this study (March 13 to October 4, 2013), effluent loading rates were approximately doubled, while rates were approximately quadrupled during Phase II (October 8, 2013 to May 29, 2014), from the maximum allowable loading rate for each product. The pipe-and-tire-chip, 46-cm-wide trench pipe-and-gravel, and the 25-cm diameter GLP products had the greatest (p < 0.001), while the 31-cm-width and the 5.4-m-long chambers had the lowest (p < 0.001) in-product solution storage during wet-soil conditions of Phase I monitoring. The 25-cm diameter GLP product had the greatest (p < 0.001), while the 61-cm-width, 5.4-m-long chamber had the lowest (p < 0.001) in-product solution storage during Phase II. Results of this study indicate that some alternative products may be able to effectively handle effluent loading rates in excess of those currently allowed by the State of Arkansas. Further research will be required to confirm these interpretations.展开更多
The real-time monitoring of environmental radiation dose for nuclear fa-cilities is an important part of safety, in order to guarantee the accuracy of the monitoring results regular calibration is necessary. Around nu...The real-time monitoring of environmental radiation dose for nuclear fa-cilities is an important part of safety, in order to guarantee the accuracy of the monitoring results regular calibration is necessary. Around nuclear facilities there are so many environmental dosimeters installed dispers-edly, because of its huge quantity, widely distributed, and in real-time monitoring state;it will cost lots of manpower and finance if it were tak-en to calibrate on standard laboratory;what’s more it will make the en-vironment out of control. To solve the problem of the measurement ac-curacy of the stationary gamma radiation dosimeter, an on-site calibra-tion method is proposed. The radioactive source is X-ray spectrum, and the dose reference instrument which has been calibrated by the national standard laboratory is a high pressure ionization. On-site calibration is divided into two parts;firstly the energy response experiment of dosim-eter for high and low energy is done in the laboratory, and the energy response curve is obtained combining with Monte Carlo simulation;sec-ondly experiment is carried out in the field of the measuring dosimeter, and the substitution method to calibrate the dosimeter is used;finally the calibration coefficient is gotten through energy curve correction. In order to verify the accuracy of on-site calibration method, the calibrated dosimeter is test in the standard laboratory and the error is 3.4%. The re-sult shows that the on-site calibration method using X-ray is feasible, and it can improves the accuracy of the measurement results of the stationary γ-ray instrument;what’s more important is that it has great reference value for the radiation safety management and radiation environment evaluation.展开更多
Because of its large capacity,high efficiency and energy savings,the subway has gradually become the primary mode of transportation for citizens.A high density of passengers exists within a large-passenger-flow subway...Because of its large capacity,high efficiency and energy savings,the subway has gradually become the primary mode of transportation for citizens.A high density of passengers exists within a large-passenger-flow subway station,and the number of casualties and injuries during a fire emergency is substantial.In this paper,Pathfinder software and on-site measured data of Pingzhou station in Shenzhen(China)were utilized to simulate a fire emergency evacuation in a large-passenger-flow subway station.The Required Safe Egress Time(RSET),number of passengers and flow rates of stairs and escalators were analysed for three fire evacuation scenarios:train fire,platform fire and hall fire.The evacuation time of the train fire,which was 1173 s,was the longest,and 3621 occupants needed to evacuate when the train was fully loaded.Occupants could not complete the evacuation within 6 mins in all three fire evacuation scenarios,which does not meet the current standard requirements and codes.By changing the number of passengers and the number of stairs for evacuation,the flow rate capacity and evacuation time were explored,which have reference values for safety management and emergency evacuation plan optimization during peak hours of subway operation.展开更多
Approximately 94 to 220 million people worldwide are at risk of drinking well water containing arsenic > 10 μg/L, the WHO guideline value. To identify non-compliant domestic wells, assess health risks and reduce e...Approximately 94 to 220 million people worldwide are at risk of drinking well water containing arsenic > 10 μg/L, the WHO guideline value. To identify non-compliant domestic wells, assess health risks and reduce exposure, accurate and rapid on-site inorganic arsenic screening methods are desirable because all domestic wells worldwide need to be tested.Here, the principles, advantages and limitations of commonly used colorimetry, electrochemistry, and biosensing methods are critically reviewed, with the performance compared with laboratory-based benchmark methods. Most commercial kits are based on the classic Gutzeit reaction. Despite being semi-quantitative, the more recent and more expensive products display improved and acceptable accuracy and shorter testing time (~10 min). Carried out by trained professionals, electrochemical methods are also feasible for on-site analysis, although miniaturization is desirable yet challenging. Biosensing using whole bacterial cells or bio-engineered materials such as aptamers is promising, if incorporated with function specific nanomaterials and biomaterials. Since arsenic is frequently found as arsenite in reducing groundwater and subject to oxidation during sampling, transportation and storage, on-site separation and sample preservation are feasible but the specific methods should be chosen based on sample matrix and tested before use. To eliminate arsenic exposure among hundreds of millions of mostly rural residents worldwide, we call for concerted efforts in research community and regulatory authority to develop accurate, rapid, and affordable tests for on-site screening and monitoring of arsenic in drinking water. Access to affordable testing will benefit people who are socioeconomically disadvantaged.展开更多
The iron element in electric arc furnace(EAF)slag is extremely difficult to recycle due to the low specific magnetic susceptibility of the RO phase(a solid solution of FeO,MgO,CaO,and MnO).Landfilling EAF slag is stri...The iron element in electric arc furnace(EAF)slag is extremely difficult to recycle due to the low specific magnetic susceptibility of the RO phase(a solid solution of FeO,MgO,CaO,and MnO).Landfilling EAF slag is strictly forbidden for environmental consideration because of poisonous Cr^(6+) leaching.The original RO phase could be transformed to a spinel structure,whose specific magnetic susceptibility is much higher than that of other minerals,through hot modification,resulting in significantly increased iron recovery by magnetic separation.Precipitation of spinel crystals encloses chromium,such that iron and chromium could be recovered simultaneously.The chromium in obtained iron concentrates is considerably useful for stainless steel making rather than polluting the environment.As a result,recovering iron and chromium is truly beneficial for cleaner production.Hot modification of EAF slag should be conducted at 1500-1600ºC for at least 60 min to guarantee homogeneous liquid slag.The liquid slag was poured onto an iron mold to obtain modified slag(MS)through air quenching.MS was characterized by thermodynamic analysis,X-ray diffraction,and scanning electron microscopy combined with energy-dispersive spectroscopy to correlate the relationship between mineral structures and iron recovery.The iron recovery rate of MS first increased and then decreased with increasing modifier.It was less than 10%when the modifier addition amount was below 12 wt.%,but it increased rapidly as the modifier addition amount increased from 16 to 24 wt.%,mainly due to spinel formation.The highest iron recovery rate was 81.9%when the modifier amount reached 20 wt.%.Meanwhile,Cr^(6+) was enriched in the spinel phase but was not observed in other minerals.Industrial tests were performed on-site with the modifier ranging from 12 to 18 wt.%because additional heat was not provided during the tests.Results showed that MS with 18 wt.%modifier addition exhibited an iron recovery rate of 61.0%,much higher than that(34.6%)of the original slag.展开更多
The pollution caused by wet weather overflow in urban drainage systems is a main factor causing blackening an odorization of urban rivers.The conventional overflow treatment based on coagulation/flocculation in termin...The pollution caused by wet weather overflow in urban drainage systems is a main factor causing blackening an odorization of urban rivers.The conventional overflow treatment based on coagulation/flocculation in terminal drainage systems requires relatively large space and long retention time demand that makes it not applicable in crowded urban drainage systems or under heavy rains.On-site coagulation/flocculation in terminal drainage pipes was proposed in this study which was aimed to transfer the coagulation/flocculation process to the inside of pipes at the terminal drainage system to save space and reduce the retention time of the coagulation/flocculation process.The optimized dose of chemicals was studied first which was 80 mg/L of coagulant and 0.8 mg/L of flocculant.Settling for only 5 min can remove most of the pollutants at 406.5 m of transmission distance.In addition,the relation of wet weather overflow rate and concentration of pollution load on the on-site coagulation/flocculation process was investigated,which indicated that high removal of pollutant was gained at a large range of flow velocity and pollutant concentration.Finally,the study confirmed electric neutralization,bridging,and net capture as the major mechanisms in this process,and further optimization was proposed.The proposed process can reduce much turbidity,chemical oxygen demand,and total phosphorous,but hardly remove soluble ammonia and organics.This work provides scientific guidance to address wet weather overflow in terminal drainage pipes.展开更多
Natural gas hydrate is a kind of clean energy with huge reserves,and the saturation(volume percentage of hydrate in pore space of sediments)is the key parameter for determining whether the reservoir is worthy of explo...Natural gas hydrate is a kind of clean energy with huge reserves,and the saturation(volume percentage of hydrate in pore space of sediments)is the key parameter for determining whether the reservoir is worthy of exploitation.In this work,rapid hydrate dissociation by the combination of heat injection and NaCl inhibitor addition was studied,and an on-site evaluation method for hydrate saturation in sediment samples was proposed by using a core sampler to transfer hydrate samples under pressure.The results showed that the average gas production rate per unit volume was increased significantly to reach 7.22 L/Lr$min-1 by the injection of NaCl aqueous solution with 50.9C,which was attributed to the increase of the chemical potential to further accelerate the rate of hydrate dissociation in the presence of NaCl.Furthermore,for the measurement of methane hydrate samples saturation with a volume of 673 cm3(which contained 1.4 mol hydrates with the saturation of 58%),hydrate saturation could be accurately achieved within 30 min with a relative error lower than 11.7%This work may provide new thoughts for on-site saturation evaluation and rapid dissociation of hydrate samples during natural gas hydrate exploitation.展开更多
Automatically identifying the degradability of municipal solid waste(MSW)is one of the key prerequisites for on-site composting to prevent contaminations from undegradable wastes.In this study,a cost-effective method ...Automatically identifying the degradability of municipal solid waste(MSW)is one of the key prerequisites for on-site composting to prevent contaminations from undegradable wastes.In this study,a cost-effective method was proposed for the degradability identification of MSW.Firstly,the trainable images in the datasets were increased by performing four different sizes of cropping operations on the original images captured on-site.Secondly,a lite convolutional neural network(CNN)model was built with only 3.37 million parameters,and then a total of eight models were trained on these datasets with and without the image augmentation operations,respectively.Finally,a degradability identification system was built for on-site composting,where the images were cut to different sizes of small squares for prediction,and the experiments were conducted to find the best combinations of the trained models and the cutting size.The results showed that the validation accuracies of the models trained with the augmentation operations were 0.91-2.07 percentage points higher,and in the evaluation of the degradability identification system the best result was achieved by the combination of W8A dataset and cutting size of 1/14 reached an accuracy of 91.58%,which indicated the capability of this cost-effective method to identify the degradability of MSW.展开更多
Hybrid high voltage direct current transmission(Hybrid HVDC)is a new type of HVDC technology developed in recent years.It combines the characteristics of large-capacity and low cost of the line commutated converters(L...Hybrid high voltage direct current transmission(Hybrid HVDC)is a new type of HVDC technology developed in recent years.It combines the characteristics of large-capacity and low cost of the line commutated converters(LCC)and non-commutation failure and dynamic reactive power support of voltage sourced converters(VSCs)in one HVDC system.It has technical advantages in the fields of unidirectional power transmission and in the application of improving the stability of multi-infeed HVDCs,giving it broad application prospects.The Kunbei-Liuzhou-Longmen(KBL)project is the first hybrid ultra HVDC project.It was put into service on Dec.27th,2020.This paper introduces the KBL project,analyzes the operation characteristics of hybrid HVDC system,and provides on-site verification of KBL project,including operation of LCC-VSC hybrid system,ultra-high voltage VSC technology using the series of two valve groups,the DC fault ride-though of hybrid VSC without using DC breaker,the connection and disconnection of a third station,and etc.展开更多
For the reasonable and effective collection of Ophiocordyceps sinensis,a new method of on-site identification was attempted using a portable multispectral imaging(MSI)technique.Three dimensional(3D)data-cubes of repre...For the reasonable and effective collection of Ophiocordyceps sinensis,a new method of on-site identification was attempted using a portable multispectral imaging(MSI)technique.Three dimensional(3D)data-cubes of representative Ophiocordyceps sinensis and weeds samples were acquired and pre-processed with standard normal variate transformation(SNV).Principal component analysis(PCA)and simulated annealing particle swarm optimisation(SAPSO)algorithms were used to extract characteristic images and develop the support vector classification(SVC)models.Results show that the fused feature model of SAPSO-SVC has the best performance,resulting in a recognition accuracy of the prediction set of 96.30%.Moreover,on-site distribution map of Ophiocordyceps sinensis and weeds was created using the spectral feature model of SAPSO-SVC,and the target could be easily identified from the distribution map.This work demonstrates the potential for on-site identification of Ophiocordyceps sinensis in the Qinghai-Tibet Plateau using a portable MSI technique combined with the SAPSO-SVC algorithm.展开更多
In this paper,a mobile augmented reality(AR)framework for on-site finite element analysis(FEA)is proposed.The proposed framework is achieved using a client–server architecture.The performance of FEA relies on several...In this paper,a mobile augmented reality(AR)framework for on-site finite element analysis(FEA)is proposed.The proposed framework is achieved using a client–server architecture.The performance of FEA relies on several important components,namely,computational power,visualization technique,and numerical analysis.AR renders intuitive computer-generated contents directly on a user’s surroundings.Integrating FEA with AR helps users through enhancing their perception and interaction with the engineering problems.Correct and effective visualization of these data using an AR platform can reduce the misinterpretation in spatial and logical aspects.Over the past decade,AR has undergone a transition from desktop to phablet computing.Mobile platforms enable user exploration of FEA results in situ.The client side uses a hybrid method to visualize FEA results in the mobile AR environment.In addition,a user can collaborate with other users by using the result sharing function.A prototype with basic functions has been built and a case study has been implemented to demonstrate the visualization method and evaluate the overall performance.展开更多
Large-scale land consolidation projects(LCPs)have been carried out on the Loess Plateau to increase the area of agriculture land.The newly created land is prone to soil erosion under the effects of water and gravity.T...Large-scale land consolidation projects(LCPs)have been carried out on the Loess Plateau to increase the area of agriculture land.The newly created land is prone to soil erosion under the effects of water and gravity.Taking a typical high-filling body(HFB)formed by LCPs in Yan’an,China as the subject,this study comprehensively investigated the types and causes of soil erosion with multiple methods of field investigation,on-site monitoring and laboratory tests.Results showed that the HFB presented a composite pattern of soil erosion with multiple types mainly including underground erosion,mixed water-gravity erosion,seepage erosion,and scouring erosion.The type of erosion varied spatially in different parts of the HFB depending on the dominant factors,mainly including the groundwater state,rainfall,runoff,gravity action,topography,and soil erodibility.The underground erosion mainly occurred at the positions with higher groundwater level and larger hydraulic gradient,while scouring erosion mainly occurred at the positions with extensive interactions of surface runoff,channel slope gradient and soil properties.And near the leading edge of the top of the slope,a band of mixed watergravity erosion occurred owing to the effects of water and gravity.In addition,nearly saturated soils at the toe of HFB displayed groundwater exfiltration and slope-face slumping.Based on our findings on the causes and variation of soil erosion for the HFB,we proposed the following erosion prevention and control measures to protect the LCPs on the Loess Plateau:to construct drainage ditches and blind ditches to form a complete drainage system,plant alfalfa on the top platform to increase rainfall interception and reduce surface runoff,set seepage ditches and plant deep-rooted plants at the toe of the slope to improve slope toe stability,monitor groundwater level and slope deformation to learn the erosion dynamics and slope stability,and optimize the geometry of HFB such as the slope gradient and slope steps to reduce soil erosion.展开更多
Tunnels deeply buried have high crustal stress and are prone to large deformation disasters when encountering soft rock.The large deformation phenomenon during the construction process of the Maoxian Tunnel on the Che...Tunnels deeply buried have high crustal stress and are prone to large deformation disasters when encountering soft rock.The large deformation phenomenon during the construction process of the Maoxian Tunnel on the Chengdu-Lanzhou Railway is particularly evident.This article focuses on the large deformation problem of the No.1 inclined shaft of the Maoxian Tunnel,and uses on-site monitoring methods to explore the reasons for tunnel structure failure,and analyzes the mechanical behavior of the tunnel structure.By using numerical simulation methods,the effectiveness of the second-layer support in resisting creep loads in tunnels was studied,and the influence of the construction time of the secondlayer support on the mechanical properties of the tunnel was discussed.The results indicate that the first-layer support in the tunnel is a structural failure caused by asymmetric deformation caused by creep,while the second-layer support has a good effect on resisting creep loads.The research results can provide a technical reference for deformation control of squeezing tunnels.展开更多
基金supported by the Scientific and Innovative Action Plan of Shanghai(21N31900800)Shanghai Rising-Star Program(23QB1403500)+4 种基金the Shanghai Sailing Program(20YF1443000)Shanghai Science and Technology Commission,the Belt and Road Project(20310750500)Talent Project of SAAS(2023-2025)Runup Plan of SAAS(ZP22211)the SAAS Program for Excellent Research Team(2022(B-16))。
文摘Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.
文摘Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)is an excellent investigation to diagnose pancreatic lesions and has shown high accuracy for its use in pathologic diagnosis.Recently,macroscopic on-site evaluation(MOSE)performed by an endoscopist was introduced as an alternative to rapid on-site cytologic evaluation to increase the diagnostic yield of EUS-FNB.The MOSE of the biopsy can estimate the adequacy of the sample directly by the macroscopic evaluation of the core tissue obtained from EUS-FNB.Isolated pancreatic tuberculosis is extremely rare and difficult to diagnose because of its non-specific signs and symptoms.Therefore,this challenging diagnosis is based on endoscopy,imaging,and the bacteriological and histological examination of tissue biopsies.This uncommon presentation of tuberculosis can be revealed as pancreatic mass mimicking cancer.EUS-FNB can be very useful in providing a valuable histopathological diagnosis.A calcified lesion with a cheesy core in MOSE must be suggestive of tuberculosis,leading to the request of the GeneXpert,which can detect Mycobacterium tuberculosis deoxyribonucleic acid and resistance to rifampicin.A decent diagnostic strategy is crucial to prevent unnecessary surgical resection and to supply conservative management with antitubercular therapy.
基金supported by the Science and technology project of State Grid Information&Telecommunication Group Co.,Ltd (SGTYHT/19-JS-218)
文摘A“cloud-edge-end”collaborative system architecture is adopted for real-time security management of power system on-site work,and mobile edge computing equipment utilizes lightweight intelligent recognition algorithms for on-site risk assessment and alert.Owing to its lightweight and fast speed,YOLOv4-Tiny is often deployed on edge computing equipment for real-time video stream detection;however,its accuracy is relatively low.This study proposes an improved YOLOv4-Tiny algorithm based on attention mechanism and optimized training methods,achieving higher accuracy without compromising the speed.Specifically,a convolution block attention module branch is added to the backbone network to enhance the feature extraction capability and an efficient channel attention mechanism is added in the neck network to improve feature utilization.Moreover,three optimized training methods:transfer learning,mosaic data augmentation,and label smoothing are used to improve the training effect of this improved algorithm.Finally,an edge computing equipment experimental platform equipped with an NVIDIA Jetson Xavier NX chip is established and the newly developed algorithm is tested on it.According to the results,the speed of the improved YOLOv4-Tiny algorithm in detecting on-site dress code compliance datasets is 17.25 FPS,and the mean average precision(mAP)is increased from 70.89%to 85.03%.
基金supported by the National Key R&D Program of China(Nos.2018YFB1003905)the National Natural Science Foundation of China under Grant No.61971032,Fundamental Research Funds for the Central Universities(No.FRF-TP-18-008A3).
文摘On-site programming big data refers to the massive data generated in the process of software development with the characteristics of real-time,complexity and high-difficulty for processing.Therefore,data cleaning is essential for on-site programming big data.Duplicate data detection is an important step in data cleaning,which can save storage resources and enhance data consistency.Due to the insufficiency in traditional Sorted Neighborhood Method(SNM)and the difficulty of high-dimensional data detection,an optimized algorithm based on random forests with the dynamic and adaptive window size is proposed.The efficiency of the algorithm can be elevated by improving the method of the key-selection,reducing dimension of data set and using an adaptive variable size sliding window.Experimental results show that the improved SNM algorithm exhibits better performance and achieve higher accuracy.
基金sponsored by the Department of Earthquake Monitoring and Prediction,China Earthquake Administration
文摘According to different testing purposes, methods and available environmental conditions, the seismograph testing can be divided into laboratory and on-site testing, respectively. The testing of the seismograph's key parameters and other concerning technical specifications are well described in guide documents(China Earthquake Administration, 2017). This includes seismometer sensitivity, linearity and clip levels based on the shake table test, as well as the seismometer natural period, damping constant based on electrical calibration(Wang Guangfu,1986; Ple?inger A.,1993) and instrumental self-noise collocation estimation(Holcomb L.G., 1989; Sleeman R. et al., 2006). However, with the development of seismic observation technology, many new requirements for the performance evaluation of seismographs have been put forward, and new testing items and methods have emerged.
文摘Approximately 20% of homes nationwide use an on-site treatment system as a form of household wastewater management. However, approximately 10% to 20% of on-site treatment systems malfunction each year, many of which have either failed or exceeded the soil’s long-term acceptance rate (LTAR), causing environmental and human health risks. The objective of this field study was to evaluate the effects of soil condition (e.g., wet and dry) and product architecture type [i.e., chamber, gravel-less-pipe (GLP), polystyrene-aggregate, and pipe-and-aggregate] on in-product solution storage and biomat thickness in a profile-limited soil in northwest Arkansas under increased loading rates and to estimate the LTAR for each product. During Phase I of this study (March 13 to October 4, 2013), effluent loading rates were approximately doubled, while rates were approximately quadrupled during Phase II (October 8, 2013 to May 29, 2014), from the maximum allowable loading rate for each product. The pipe-and-tire-chip, 46-cm-wide trench pipe-and-gravel, and the 25-cm diameter GLP products had the greatest (p < 0.001), while the 31-cm-width and the 5.4-m-long chambers had the lowest (p < 0.001) in-product solution storage during wet-soil conditions of Phase I monitoring. The 25-cm diameter GLP product had the greatest (p < 0.001), while the 61-cm-width, 5.4-m-long chamber had the lowest (p < 0.001) in-product solution storage during Phase II. Results of this study indicate that some alternative products may be able to effectively handle effluent loading rates in excess of those currently allowed by the State of Arkansas. Further research will be required to confirm these interpretations.
文摘The real-time monitoring of environmental radiation dose for nuclear fa-cilities is an important part of safety, in order to guarantee the accuracy of the monitoring results regular calibration is necessary. Around nuclear facilities there are so many environmental dosimeters installed dispers-edly, because of its huge quantity, widely distributed, and in real-time monitoring state;it will cost lots of manpower and finance if it were tak-en to calibrate on standard laboratory;what’s more it will make the en-vironment out of control. To solve the problem of the measurement ac-curacy of the stationary gamma radiation dosimeter, an on-site calibra-tion method is proposed. The radioactive source is X-ray spectrum, and the dose reference instrument which has been calibrated by the national standard laboratory is a high pressure ionization. On-site calibration is divided into two parts;firstly the energy response experiment of dosim-eter for high and low energy is done in the laboratory, and the energy response curve is obtained combining with Monte Carlo simulation;sec-ondly experiment is carried out in the field of the measuring dosimeter, and the substitution method to calibrate the dosimeter is used;finally the calibration coefficient is gotten through energy curve correction. In order to verify the accuracy of on-site calibration method, the calibrated dosimeter is test in the standard laboratory and the error is 3.4%. The re-sult shows that the on-site calibration method using X-ray is feasible, and it can improves the accuracy of the measurement results of the stationary γ-ray instrument;what’s more important is that it has great reference value for the radiation safety management and radiation environment evaluation.
基金This study has been sponsored by the Fire Bureau of the Ministry of Public Security(Grant No.2016XFGG05)the Sichuan Mineral Resources Research Center(Grant No.SCKCZY2022-YB010)the Key Laboratory of Flight Techniques and Flight Safety,CAAC(Grant No.FZ2021KF05).
文摘Because of its large capacity,high efficiency and energy savings,the subway has gradually become the primary mode of transportation for citizens.A high density of passengers exists within a large-passenger-flow subway station,and the number of casualties and injuries during a fire emergency is substantial.In this paper,Pathfinder software and on-site measured data of Pingzhou station in Shenzhen(China)were utilized to simulate a fire emergency evacuation in a large-passenger-flow subway station.The Required Safe Egress Time(RSET),number of passengers and flow rates of stairs and escalators were analysed for three fire evacuation scenarios:train fire,platform fire and hall fire.The evacuation time of the train fire,which was 1173 s,was the longest,and 3621 occupants needed to evacuate when the train was fully loaded.Occupants could not complete the evacuation within 6 mins in all three fire evacuation scenarios,which does not meet the current standard requirements and codes.By changing the number of passengers and the number of stairs for evacuation,the flow rate capacity and evacuation time were explored,which have reference values for safety management and emergency evacuation plan optimization during peak hours of subway operation.
基金Support was provided by NSFC grants 41831279 and 41772265 to Yan Zhenggrant 2021YFA0715900 from the National Key Research and Development Program of China。
文摘Approximately 94 to 220 million people worldwide are at risk of drinking well water containing arsenic > 10 μg/L, the WHO guideline value. To identify non-compliant domestic wells, assess health risks and reduce exposure, accurate and rapid on-site inorganic arsenic screening methods are desirable because all domestic wells worldwide need to be tested.Here, the principles, advantages and limitations of commonly used colorimetry, electrochemistry, and biosensing methods are critically reviewed, with the performance compared with laboratory-based benchmark methods. Most commercial kits are based on the classic Gutzeit reaction. Despite being semi-quantitative, the more recent and more expensive products display improved and acceptable accuracy and shorter testing time (~10 min). Carried out by trained professionals, electrochemical methods are also feasible for on-site analysis, although miniaturization is desirable yet challenging. Biosensing using whole bacterial cells or bio-engineered materials such as aptamers is promising, if incorporated with function specific nanomaterials and biomaterials. Since arsenic is frequently found as arsenite in reducing groundwater and subject to oxidation during sampling, transportation and storage, on-site separation and sample preservation are feasible but the specific methods should be chosen based on sample matrix and tested before use. To eliminate arsenic exposure among hundreds of millions of mostly rural residents worldwide, we call for concerted efforts in research community and regulatory authority to develop accurate, rapid, and affordable tests for on-site screening and monitoring of arsenic in drinking water. Access to affordable testing will benefit people who are socioeconomically disadvantaged.
基金supported by Sichuan Province Science_and Technology Program(201904a05020008)Anhui Province Science and Technology Program(2019YFSY0029)the Open Project Funding from State Key Laboratory of Solid Waste Reuse for Building Materials(No.SWR-2017-005).
文摘The iron element in electric arc furnace(EAF)slag is extremely difficult to recycle due to the low specific magnetic susceptibility of the RO phase(a solid solution of FeO,MgO,CaO,and MnO).Landfilling EAF slag is strictly forbidden for environmental consideration because of poisonous Cr^(6+) leaching.The original RO phase could be transformed to a spinel structure,whose specific magnetic susceptibility is much higher than that of other minerals,through hot modification,resulting in significantly increased iron recovery by magnetic separation.Precipitation of spinel crystals encloses chromium,such that iron and chromium could be recovered simultaneously.The chromium in obtained iron concentrates is considerably useful for stainless steel making rather than polluting the environment.As a result,recovering iron and chromium is truly beneficial for cleaner production.Hot modification of EAF slag should be conducted at 1500-1600ºC for at least 60 min to guarantee homogeneous liquid slag.The liquid slag was poured onto an iron mold to obtain modified slag(MS)through air quenching.MS was characterized by thermodynamic analysis,X-ray diffraction,and scanning electron microscopy combined with energy-dispersive spectroscopy to correlate the relationship between mineral structures and iron recovery.The iron recovery rate of MS first increased and then decreased with increasing modifier.It was less than 10%when the modifier addition amount was below 12 wt.%,but it increased rapidly as the modifier addition amount increased from 16 to 24 wt.%,mainly due to spinel formation.The highest iron recovery rate was 81.9%when the modifier amount reached 20 wt.%.Meanwhile,Cr^(6+) was enriched in the spinel phase but was not observed in other minerals.Industrial tests were performed on-site with the modifier ranging from 12 to 18 wt.%because additional heat was not provided during the tests.Results showed that MS with 18 wt.%modifier addition exhibited an iron recovery rate of 61.0%,much higher than that(34.6%)of the original slag.
文摘The pollution caused by wet weather overflow in urban drainage systems is a main factor causing blackening an odorization of urban rivers.The conventional overflow treatment based on coagulation/flocculation in terminal drainage systems requires relatively large space and long retention time demand that makes it not applicable in crowded urban drainage systems or under heavy rains.On-site coagulation/flocculation in terminal drainage pipes was proposed in this study which was aimed to transfer the coagulation/flocculation process to the inside of pipes at the terminal drainage system to save space and reduce the retention time of the coagulation/flocculation process.The optimized dose of chemicals was studied first which was 80 mg/L of coagulant and 0.8 mg/L of flocculant.Settling for only 5 min can remove most of the pollutants at 406.5 m of transmission distance.In addition,the relation of wet weather overflow rate and concentration of pollution load on the on-site coagulation/flocculation process was investigated,which indicated that high removal of pollutant was gained at a large range of flow velocity and pollutant concentration.Finally,the study confirmed electric neutralization,bridging,and net capture as the major mechanisms in this process,and further optimization was proposed.The proposed process can reduce much turbidity,chemical oxygen demand,and total phosphorous,but hardly remove soluble ammonia and organics.This work provides scientific guidance to address wet weather overflow in terminal drainage pipes.
基金the National Natural Science Foundation of China(21736005)the National Key R&D Program of China(2016YFC0304006 and 2017YFC0307302).
文摘Natural gas hydrate is a kind of clean energy with huge reserves,and the saturation(volume percentage of hydrate in pore space of sediments)is the key parameter for determining whether the reservoir is worthy of exploitation.In this work,rapid hydrate dissociation by the combination of heat injection and NaCl inhibitor addition was studied,and an on-site evaluation method for hydrate saturation in sediment samples was proposed by using a core sampler to transfer hydrate samples under pressure.The results showed that the average gas production rate per unit volume was increased significantly to reach 7.22 L/Lr$min-1 by the injection of NaCl aqueous solution with 50.9C,which was attributed to the increase of the chemical potential to further accelerate the rate of hydrate dissociation in the presence of NaCl.Furthermore,for the measurement of methane hydrate samples saturation with a volume of 673 cm3(which contained 1.4 mol hydrates with the saturation of 58%),hydrate saturation could be accurately achieved within 30 min with a relative error lower than 11.7%This work may provide new thoughts for on-site saturation evaluation and rapid dissociation of hydrate samples during natural gas hydrate exploitation.
基金The authors acknowledge that this study was financially supported by the National Key R&D Program of China(Grant No.2020YFD1000300No.2018YFD0200801)+1 种基金National ten thousand talents special support program of China[2018]no.29Innovation and Entrepreneurship Training Program of Hunan Agricultural University(Grant No.2019062x).
文摘Automatically identifying the degradability of municipal solid waste(MSW)is one of the key prerequisites for on-site composting to prevent contaminations from undegradable wastes.In this study,a cost-effective method was proposed for the degradability identification of MSW.Firstly,the trainable images in the datasets were increased by performing four different sizes of cropping operations on the original images captured on-site.Secondly,a lite convolutional neural network(CNN)model was built with only 3.37 million parameters,and then a total of eight models were trained on these datasets with and without the image augmentation operations,respectively.Finally,a degradability identification system was built for on-site composting,where the images were cut to different sizes of small squares for prediction,and the experiments were conducted to find the best combinations of the trained models and the cutting size.The results showed that the validation accuracies of the models trained with the augmentation operations were 0.91-2.07 percentage points higher,and in the evaluation of the degradability identification system the best result was achieved by the combination of W8A dataset and cutting size of 1/14 reached an accuracy of 91.58%,which indicated the capability of this cost-effective method to identify the degradability of MSW.
基金This work was supported by CSG project(KYKJXM20210204).
文摘Hybrid high voltage direct current transmission(Hybrid HVDC)is a new type of HVDC technology developed in recent years.It combines the characteristics of large-capacity and low cost of the line commutated converters(LCC)and non-commutation failure and dynamic reactive power support of voltage sourced converters(VSCs)in one HVDC system.It has technical advantages in the fields of unidirectional power transmission and in the application of improving the stability of multi-infeed HVDCs,giving it broad application prospects.The Kunbei-Liuzhou-Longmen(KBL)project is the first hybrid ultra HVDC project.It was put into service on Dec.27th,2020.This paper introduces the KBL project,analyzes the operation characteristics of hybrid HVDC system,and provides on-site verification of KBL project,including operation of LCC-VSC hybrid system,ultra-high voltage VSC technology using the series of two valve groups,the DC fault ride-though of hybrid VSC without using DC breaker,the connection and disconnection of a third station,and etc.
基金This work was funded by the Fundamental Research Funds for the Central Universities(2017TC016)and the National Key Research and Development Program of China(2016YFE0112800).
文摘For the reasonable and effective collection of Ophiocordyceps sinensis,a new method of on-site identification was attempted using a portable multispectral imaging(MSI)technique.Three dimensional(3D)data-cubes of representative Ophiocordyceps sinensis and weeds samples were acquired and pre-processed with standard normal variate transformation(SNV).Principal component analysis(PCA)and simulated annealing particle swarm optimisation(SAPSO)algorithms were used to extract characteristic images and develop the support vector classification(SVC)models.Results show that the fused feature model of SAPSO-SVC has the best performance,resulting in a recognition accuracy of the prediction set of 96.30%.Moreover,on-site distribution map of Ophiocordyceps sinensis and weeds was created using the spectral feature model of SAPSO-SVC,and the target could be easily identified from the distribution map.This work demonstrates the potential for on-site identification of Ophiocordyceps sinensis in the Qinghai-Tibet Plateau using a portable MSI technique combined with the SAPSO-SVC algorithm.
文摘In this paper,a mobile augmented reality(AR)framework for on-site finite element analysis(FEA)is proposed.The proposed framework is achieved using a client–server architecture.The performance of FEA relies on several important components,namely,computational power,visualization technique,and numerical analysis.AR renders intuitive computer-generated contents directly on a user’s surroundings.Integrating FEA with AR helps users through enhancing their perception and interaction with the engineering problems.Correct and effective visualization of these data using an AR platform can reduce the misinterpretation in spatial and logical aspects.Over the past decade,AR has undergone a transition from desktop to phablet computing.Mobile platforms enable user exploration of FEA results in situ.The client side uses a hybrid method to visualize FEA results in the mobile AR environment.In addition,a user can collaborate with other users by using the result sharing function.A prototype with basic functions has been built and a case study has been implemented to demonstrate the visualization method and evaluate the overall performance.
基金the National Natural Science Foundation of China(Grant Nos.41790443,41927806,and 32071586)the Fundamental Research Funds for the Central Universities(Grant Nos.300102212213)Young Talent Fund of Association for Science and Technology in Shaanxi,China(Grant No.20220707)。
文摘Large-scale land consolidation projects(LCPs)have been carried out on the Loess Plateau to increase the area of agriculture land.The newly created land is prone to soil erosion under the effects of water and gravity.Taking a typical high-filling body(HFB)formed by LCPs in Yan’an,China as the subject,this study comprehensively investigated the types and causes of soil erosion with multiple methods of field investigation,on-site monitoring and laboratory tests.Results showed that the HFB presented a composite pattern of soil erosion with multiple types mainly including underground erosion,mixed water-gravity erosion,seepage erosion,and scouring erosion.The type of erosion varied spatially in different parts of the HFB depending on the dominant factors,mainly including the groundwater state,rainfall,runoff,gravity action,topography,and soil erodibility.The underground erosion mainly occurred at the positions with higher groundwater level and larger hydraulic gradient,while scouring erosion mainly occurred at the positions with extensive interactions of surface runoff,channel slope gradient and soil properties.And near the leading edge of the top of the slope,a band of mixed watergravity erosion occurred owing to the effects of water and gravity.In addition,nearly saturated soils at the toe of HFB displayed groundwater exfiltration and slope-face slumping.Based on our findings on the causes and variation of soil erosion for the HFB,we proposed the following erosion prevention and control measures to protect the LCPs on the Loess Plateau:to construct drainage ditches and blind ditches to form a complete drainage system,plant alfalfa on the top platform to increase rainfall interception and reduce surface runoff,set seepage ditches and plant deep-rooted plants at the toe of the slope to improve slope toe stability,monitor groundwater level and slope deformation to learn the erosion dynamics and slope stability,and optimize the geometry of HFB such as the slope gradient and slope steps to reduce soil erosion.
基金the National Natural Science Foundation of China(Grant No.51978041)。
文摘Tunnels deeply buried have high crustal stress and are prone to large deformation disasters when encountering soft rock.The large deformation phenomenon during the construction process of the Maoxian Tunnel on the Chengdu-Lanzhou Railway is particularly evident.This article focuses on the large deformation problem of the No.1 inclined shaft of the Maoxian Tunnel,and uses on-site monitoring methods to explore the reasons for tunnel structure failure,and analyzes the mechanical behavior of the tunnel structure.By using numerical simulation methods,the effectiveness of the second-layer support in resisting creep loads in tunnels was studied,and the influence of the construction time of the secondlayer support on the mechanical properties of the tunnel was discussed.The results indicate that the first-layer support in the tunnel is a structural failure caused by asymmetric deformation caused by creep,while the second-layer support has a good effect on resisting creep loads.The research results can provide a technical reference for deformation control of squeezing tunnels.
