The working group on design and evaluation of intelligent system ergonomics,under SAC/TC 7,Ergonomics,was officially established in Qingdao city,Shandong province on June 18.The launching ceremony was jointly organize...The working group on design and evaluation of intelligent system ergonomics,under SAC/TC 7,Ergonomics,was officially established in Qingdao city,Shandong province on June 18.The launching ceremony was jointly organized by the Sub-institute of Fundamental Standardization of CNIS and China Standard Certification Co.,Ltd.It was attended by more than 60 experts and industry representatives in fields such as smart home technology,intelligent driving,wearable devices,medical health,and nuclear engineering.展开更多
BACKGROUND Working memory serves as a fundamental cognitive function that substantially impacts performance in various cognitive tasks.Extensive neurophysiological research has established that theta oscillations(4-8 ...BACKGROUND Working memory serves as a fundamental cognitive function that substantially impacts performance in various cognitive tasks.Extensive neurophysiological research has established that theta oscillations(4-8 Hz)play an essential role in supporting working memory operations.Theta-band transcranial alternating current stimulation(tACS)offers a potential mechanism for working memory enhancement through direct modulation of these fundamental neural oscillations.Nevertheless,current empirical evidence shows substantial variability in the observed effects of theta-tACS across studies.AIM To conduct a systematic review and meta-analysis evaluating the effects of thetatACS on working memory performance in healthy adults.METHODS A systematic literature search was performed on PubMed,EMBASE,and Web of Science up to March 10,2025.Effect sizes were computed using Hedges’g with 95%confidence intervals(CIs),with separate meta-analyses for all included studies and for distinct working memory paradigms[n-back and delayed matchto-sample(DMTS)tasks]to examine potential task-specific effects.Subgroup analyses and meta-regression were performed to evaluate the influence of key moderating variables.RESULTS The systematic review included 21 studies(67 effect sizes).Initial meta-analysis showed theta-tACS moderately improved working memory(Hedges’g=0.405,95%CI:0.212-0.598).However,this effect became nonsignificant after correcting for publication bias(trim-and-fill adjusted Hedges’g=0.082,95%CI:-0.052 to 0.217).Task-specific analyses revealed significant benefits in n-back tasks(Hedges’g=0.463,95%CI:0.193-0.733)but not in DMTS tasks(Hedges’g=0.257,95%CI:-0.186 to 0.553).Moderator analyses showed that performance in n-back tasks was influenced by stimulation frequency(P=0.001),concurrent status(P=0.014),task modality(P=0.005),and duration(P=0.013),whereas only the region of targeted stimulation(P=0.012)moderated DMTS tasks.CONCLUSION Theta-tACS enhances working memory in healthy adults,with effects modulated by the task type and protocol parameters,offering dual implications for cognitive enhancement and clinical interventions.展开更多
The optimization of working fluids in single-well coaxial geothermal systems presents a critical pathway for advancing the use of enhanced geothermal systems(EGS)in renewable energy applications.This study evaluates t...The optimization of working fluids in single-well coaxial geothermal systems presents a critical pathway for advancing the use of enhanced geothermal systems(EGS)in renewable energy applications.This study evaluates the thermo-hydraulic performance of three working fluids(H_(2)O,CO_(2),and H_(2))in a single-well coaxial geothermal system,focusing on the effects of their injection temperatures.Using a 3D finite element model in COMSOL Multiphysics,simulations were conducted at three injection temperatures(17℃,27℃,40℃)under constant mass flow rates.The results reveal that hydrogen significantly outperforms water and carbon dioxide,achieving a 297.77% and 5453.76% higher thermal output,respectively.Notably,the heat transfer efficiency is significantly improved when the injected working fluids are at 40℃,compared to 27℃;this demonstrates a positive correlation between injection temperature and thermal recovery.Though water systems exhibit better geological compatibility,the superior thermal properties of hydrogen position it as a promising alternative-despite potential subsurface challenges.This study provides critical insights for advancing the application of high-efficiency geothermal systems as well as the development of non-aqueous working fluids,thus contributing to the sustainable utilization of geothermal energy.展开更多
This paper is concerned with a non-intrusive anomaly detection method for carving machine systems with variant working conditions,and a novel unsupervised detection framework that integrates convolutional autoencoder(...This paper is concerned with a non-intrusive anomaly detection method for carving machine systems with variant working conditions,and a novel unsupervised detection framework that integrates convolutional autoencoder(CAE)and Gaussian mixture hidden Markov model(GMHMM)is proposed.Firstly,the built-in sensor information under normal conditions is recorded,and a 1D convolutional autoencoder is employed to compress high-dimensional time series,thereby transforming the anomaly detection problem in high-dimensional space into a density estimation problem in a latent low-dimensional space.Then,two separate estimation networks are utilized to predict the mixture memberships and state transition probabilities for each sample,enabling GMHMM to handle low-dimensional representations and multi-condition information.Furthermore,a cost function comprising CAE reconstruction and GMHMM probability assessment is constructed for the low-dimensional representation generation and subsequent density estimation in an end-to-end fashion,and the joint optimization effectively enhances the anomaly detection performance.Finally,experiments are carried out on a self-developed multi-axis carving machine platform to validate the effectiveness and superiority of the proposed method.展开更多
BACKGROUND There has been an increasing focus in recent years on health-care disparities.Studies investigating return to work(RTW)or sports are often performed in large,urban areas.Relatively few studies have investig...BACKGROUND There has been an increasing focus in recent years on health-care disparities.Studies investigating return to work(RTW)or sports are often performed in large,urban areas.Relatively few studies have investigated rates of return to farming or other heavy labor that is of interest to patients in rural areas.AIM To evaluate the literature regarding RTW in farming or heavy labor after orthopedic hip,knee,or shoulder surgery.METHODS A search was performed in the PubMed and EMBASE databases using Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines.Studies were included if they reported patients employed in farming or heavy labor,RTW rates after orthopedic surgery of the hip,knee,or shoulder,and had a minimum 6-month follow-up.A meta-analysis of proportions using a random-effects model was performed on three single-arm observational studies to estimate the pooled RTW rate following arthroscopic shoulder surgery.RESULTS Ten studies were included,and 101 farmers were identified among 440 total patients.One study involved hip surgery,two studies involved knee surgery,and seven studies involved shoulder surgery.RTW rates across studies varied by type of surgery and follow-up interval,ranging from 24%to 100%.The RTW rate was only 53.6%at 1 year following total hip arthroplasty.No studies investigated RTW in farmers following total knee arthroplasty.Among non-comparative studies,meta-analysis revealed a pooled RTW rate of 89%following arthroscopic shoulder surgery,with low heterogeneity(I^(2)=30.1%).Among comparative studies,one study reported significantly higher RTW odds for patients undergoing anatomic total shoulder arthroplasty compared to reverse shoulder arthroplasty(odds ratio=5.45).Overall,surgical intervention for shoulder pathology was associated with a high likelihood of RTW across multiple techniques,with particularly favorable outcomes for anatomic total shoulder arthroplasty.CONCLUSION This systematic review highlights the high rates of RTW in farmers and heavy laborers after shoulder surgery.However,our findings also underscore the need for more rural-specific research to guide patient counseling,rehabilitation expectations,and shared decision-making in this underserved population,particularly for orthopedic surgery of the hip and knee.展开更多
The submersible pumping unit is a new type of pumping system for lifting formation fluids from onshore oil wells, and the identification of its working condition has an important influence on oil production. In this p...The submersible pumping unit is a new type of pumping system for lifting formation fluids from onshore oil wells, and the identification of its working condition has an important influence on oil production. In this paper we proposed a diagnostic method for identifying the working condition of the submersible pumping system. Based on analyzing the working principle of the pumping unit and the pump structure, different characteristics in loading and unloading processes of the submersible linear motor were obtained at different working conditions. The characteristic quantities were extracted from operation data of the submersible linear motor. A diagnostic model based on the support vector machine （SVM） method was proposed for identifying the working condition of the submersible pumping unit, where the inputs of the SVM classifier were the characteristic quantities. The performance and the misjudgment rate of this method were analyzed and validated by the data acquired from an experimental simulation platform. The model proposed had an excellent performance in failure diagnosis of the submersible pumping system. The SVM classifier had higher diagnostic accuracy than the learning vector quantization （LVQ） classifier.展开更多
Effcient behavioral assays are crucial for understanding the neural mechanisms of cognitive functions.Here, we designed a high-throughput automatic training system for spatial cognition(HASS) for free-moving mice.Mice...Effcient behavioral assays are crucial for understanding the neural mechanisms of cognitive functions.Here, we designed a high-throughput automatic training system for spatial cognition(HASS) for free-moving mice.Mice were trained to return to the home arm and remain there during a delay period. Software was designed to enable automatic training in all its phases, including habituation, shaping, and learning. Using this system, we trained mice to successfully perform a spatially delayed nonmatch to sample task, which tested spatial cognition,working memory, and decision making. Performance depended on the delay duration, which is a hallmark of working memory tasks. The HASS enabled a human operator to train more than six mice simultaneously with minimal intervention, therefore greatly enhancing experimental efficiency and minimizing stress to the mice.Combined with the optogenetic method and neurophysiological techniques, the HASS will be useful in deciphering the neural circuitry underlying spatial cognition.展开更多
The accurate and intelligent identification of the working conditions of a sucker-rod pumping system is necessary. As onshore oil extraction gradually enters its mid-to late-stage, the cost required to train a deep le...The accurate and intelligent identification of the working conditions of a sucker-rod pumping system is necessary. As onshore oil extraction gradually enters its mid-to late-stage, the cost required to train a deep learning working condition recognition model for pumping wells by obtaining enough new working condition samples is expensive. For the few-shot problem and large calculation issues of new working conditions of oil wells, a working condition recognition method for pumping unit wells based on a 4-dimensional time-frequency signature (4D-TFS) and meta-learning convolutional shrinkage neural network (ML-CSNN) is proposed. First, the measured pumping unit well workup data are converted into 4D-TFS data, and the initial feature extraction task is performed while compressing the data. Subsequently, a convolutional shrinkage neural network (CSNN) with a specific structure that can ablate low-frequency features is designed to extract working conditions features. Finally, a meta-learning fine-tuning framework for learning the network parameters that are susceptible to task changes is merged into the CSNN to solve the few-shot issue. The results of the experiments demonstrate that the trained ML-CSNN has good recognition accuracy and generalization ability for few-shot working condition recognition. More specifically, in the case of lower computational complexity, only few-shot samples are needed to fine-tune the network parameters, and the model can be quickly adapted to new classes of well conditions.展开更多
High-precision and real-time diagnosis of sucker rod pumping system(SRPS)is important for quickly mastering oil well operations.Deep learning-based method for classifying the dynamometer card(DC)of oil wells is an eff...High-precision and real-time diagnosis of sucker rod pumping system(SRPS)is important for quickly mastering oil well operations.Deep learning-based method for classifying the dynamometer card(DC)of oil wells is an efficient diagnosis method.However,the input of the DC as a two-dimensional image into the deep learning framework suffers from low feature utilization and high computational effort.Additionally,different SRPSs in an oil field have various system parameters,and the same SRPS generates different DCs at different moments.Thus,there is heterogeneity in field data,which can dramatically impair the diagnostic accuracy.To solve the above problems,a working condition recognition method based on 4-segment time-frequency signature matrix(4S-TFSM)and deep learning is presented in this paper.First,the 4-segment time-frequency signature(4S-TFS)method that can reduce the computing power requirements is proposed for feature extraction of DC data.Subsequently,the 4S-TFSM is constructed by relative normalization and matrix calculation to synthesize the features of multiple data and solve the problem of data heterogeneity.Finally,a convolutional neural network(CNN),one of the deep learning frameworks,is used to determine the functioning conditions based on the 4S-TFSM.Experiments on field data verify that the proposed diagnostic method based on 4S-TFSM and CNN(4S-TFSM-CNN)can significantly improve the accuracy of working condition recognition with lower computational cost.To the best of our knowledge,this is the first work to discuss the effect of data heterogeneity on the working condition recognition performance of SRPS.展开更多
For efficient utilization of a limited geothermal resource in practical projects,the cycle parameters were comprehensively analyzed by combining with the heat transfer performance of the plate heat exchanger,with a va...For efficient utilization of a limited geothermal resource in practical projects,the cycle parameters were comprehensively analyzed by combining with the heat transfer performance of the plate heat exchanger,with a variation of flowrate of R245 fa.The influence of working fluid flowrate on a 500 W ORC system was investigated.Adjusting the working fluid flowrate to an optimal value results in the most efficient heat transfer and hence the optimal heat transfer parameters of the plate heat exchanger can be determined.Therefore,for the ORC systems,optimal working fluid flowrate should be controlled.Using different temperature hot water as the heat source,it is found that the optimal flowrate increases by 6-10 L/h with 5 ℃ increment of hot water inlet temperature.During experiment,lower degree of superheat of the working fluid at the outlet the plate heat exchanger may lead to unstable power generation.It is considered that the plate heat exchanger has a compact construction which makes its bulk so small that liquid mixture causes the unstable power generation.To avoid this phenomenon,the flow area of plate heat exchanger should be larger than the designed one.Alternatively,installing a small shell and tube heat exchanger between the outlet of plate heat exchanger and the inlet of expander can be another solution.展开更多
In order to develop the technology of the controlled recircuIation of airflow in the world, some formulas about the airflow recirculation system in the working face with leaking airflow are deduced,which reduces the e...In order to develop the technology of the controlled recircuIation of airflow in the world, some formulas about the airflow recirculation system in the working face with leaking airflow are deduced,which reduces the error between calculating and real values. on the base of the application of the formulas mentioned above, the problem about lack of airflow in the working face 2712 was solved successfully in Xiandewang Coal Mine.展开更多
The difficult problem of automatically welding nipples onto the header is first analyzed in this paper, and then the overall structure and operating principle of the robot working unit are introduced. The robot and th...The difficult problem of automatically welding nipples onto the header is first analyzed in this paper, and then the overall structure and operating principle of the robot working unit are introduced. The robot and the measuring device are located by employing the traveling lorry, and this unit enables the robot to adjust the tracks according to the errors received from the measuring device, and then the nipples are welded properly. This paper emphases on the development of the master-slave control system, in which the prograrmmable Logic Controller (PLC) is used as the master computer.展开更多
The objective of this paper is to present a simulation study on the two-stage absorption refrigeration systems of 2.5 kW capacity using LiBr-H2O,NH3-H2O and R124-DMAC as working pairs.Under the design condition that t...The objective of this paper is to present a simulation study on the two-stage absorption refrigeration systems of 2.5 kW capacity using LiBr-H2O,NH3-H2O and R124-DMAC as working pairs.Under the design condition that the generating,absorbing,evaporating and condensing temperatures are 75℃,45℃,5℃and 40℃,respectively,the high and low pressure side solution circulation ratios and the coefficient of performance(COP)for the systems are calculated.Then the influences of medium,generating,absorbing,evaporating and condensing temperatures on system performances are analyzed.The results show that under the design condition,the COP of the LiBr-H2Osystem can reach 0.49,superior to those of the NH3-H2O and R124-DMAC systems,which are 0.32 and 0.31,respectively.Furthermore,the medium temperature for higher COP lies in an interval of 64-67℃for the LiBr-H2O.NH3-H2O and R124-DMAC systems.High generating temperature and low absorbing temperature can decrease the high and low pressure side solution circulation ratios,and can also increase the COP.High evaporating temperature can decrease the low pressure side solution circulation ratio and increase the COP.Low condensing temperature can decrease the high pressure side solution circulation ratio and increase the COP.展开更多
Solid adsorption system, one of alternative refrigeration systems, is utilized to provide cold for refrigerator or air-conditioner and can be operated by assistance of solar heat. System performance study through comp...Solid adsorption system, one of alternative refrigeration systems, is utilized to provide cold for refrigerator or air-conditioner and can be operated by assistance of solar heat. System performance study through computer usage to develop simulation program and simulate behaviors of system operation can give designed system which suits for user’s need. Also, the present study aims to develop dynamic simulation program of solid adsorption refrigeration system operated by solar assistance to simulate behaviors of system operation and its performance. Flat plate collectror is utilized to provide thermal energy for system’s adsorber and activated carbon/methanol is used to be a suitable working pair. Simulation procedure starts with various solar radiation intensities as input energy on solar collector and water is used as collector working fluid. Behavior of system operation can be considered to be 4 steps as isosteric heating, isobaric desorption, isosteric cooling and isobaric adsorption, respectively. This research studies the effect of varying solar radiation intensity on temperature, pressure of adsorber, adsorption ratio at each steps of system operated ranging from 6:00 am (the first day) to 6:00 am (the next day) and system performance which is defined as coefficient of performance, COP. In addition, the simulation result shows monthly average COP of 0.43 compared to a result of another previous research work under the same operating condition and the percentage error is 7.5%.展开更多
One of the effective options for energy saving in terms of heat costs for the formation of routine thermal conditions of working areas of large-sized industrial premises is the replacement of traditional convective(wa...One of the effective options for energy saving in terms of heat costs for the formation of routine thermal conditions of working areas of large-sized industrial premises is the replacement of traditional convective(water)heating systems with systems,the main part of which are gas infrared emitters.But the mass introduction of such systems based on emitters was held back until recently by the lack of scientific and technical foundations for ensuring not only the routine thermal conditions of local working areas,but also ensuring acceptable concentrations of carbon dioxide,which is formed during the operation of a gas emitter.Solving the latter problem by the method of experimental selection of heating and air exchange modes is practically impossible due to the multivariate nature of possible solutions to this problem.Therefore,the purpose of the work is to analyze the results of theoretical studies of the possibility of ensuring an acceptable level of carbon dioxide concentrations in local working areas during the operation of gas infrared emitters and an air exchange system.Numerical modeling of heat and mass transfer processes under such conditions was performed in a fairly wide range of the main significant factors:air flow rate in the air exchange system from 0.01 to 0.04 kg/s,the position of the air inlet and outlet channels relative to the radiator and the local workplace(height from 0.3 to 4.1 m).It was found that by varying the numerical values of these factors,it is possible to ensure carbon dioxide concentrations in the local working area within the permissible limits of up to 1400 ppm.展开更多
The design philosophy based on the working process systematization, the feature of practice teaching is analyzed the principles of practice teaching quality evaluation system are summed up. The evaluation system based...The design philosophy based on the working process systematization, the feature of practice teaching is analyzed the principles of practice teaching quality evaluation system are summed up. The evaluation system based on working process systematization of the practice teaching quality is established, the management of quality evaluation system and the project of the monitoring are put forward.展开更多
With the civilization and modernization of human society,occupational health has emerged as a fundamental goal of social justice,as highlighted in the United Nations'Sustainable Development Goals(SDGs)since 2016.S...With the civilization and modernization of human society,occupational health has emerged as a fundamental goal of social justice,as highlighted in the United Nations'Sustainable Development Goals(SDGs)since 2016.Specifically,"SDG Goal 1:No Poverty","SDG 3:Good Health and Well-being",and"SDG 8:Decent Work and Economic Growth",are interconnected with other SDGs to support the pursuit of occupational health.展开更多
Coronavirus is a Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) caused by a novel coronavirus belonging to the family Coronaviridae. The disease was first discovered in December 2019 in Wuhan City, Hubei...Coronavirus is a Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) caused by a novel coronavirus belonging to the family Coronaviridae. The disease was first discovered in December 2019 in Wuhan City, Hubei Province, China. A few months later, the disease spread all over the world and became an epidemic. The infection for most people is mild to moderate but in Vulnerable groups, if they have the infections, they might experience severe COVID-19. Saudi Arabia initiated its response plan early, and all sectors and agencies worked in an integrated way to combat the disease. It has maintained proper communication during the pandemic and ensured community involvement, epidemiologic surveillance, and activation of rapid response teams. The COVID-19 pandemic significantly affected daily lives. Schools and daycares were closed, education was online, traveling stopped, work was suspended, gathering in social activities and practicing religious rituals, like praying or doing Umrah or Hajj, were banded. Changing lifestyles as a response to COVID-19 impacted whole communities with different categories of children, parents, and families. Women usually take the majority of daily responsibilities. The sudden change in lifestyle during COVID-19 put pressure on mothers, especially those who are working to balance work and family obligations. This study aims to identify the impact of Coronavirus disease 2019 on working mothers in Saudi Arabia. Method: Data of the study was collected through survey posted on social media and analyzed through Excel. It focuses on five aspects: health, lifestyle, social relations, work production and financial status. Our target population was working mothers in Saudi Arabia aged at least 25 years. Results: In this study, all factors affected working mothers categorized under two groups: Social Economic Status and Work suspension. For Social Economic Status factors, we find five factors which are monthly income, main breadwinner, number of children at school age, type of housing, and type of work. Almost all mothers include spiritual activities to their routine to cope with stress during this period. About half of our sample have negative impact on their mental health because they are the main breadwinner, and mothers with a smaller number of children at school age have more challenges to cope up. We found that mothers who own a house or work at governmental sector have better outcome of health. After analyzing data related to Work suspension, we found that mothers who have work support have better management for life circumstances, however their health outcomes were negatively affected. In addition, mothers working at education sector have the highest positive impact among other sectors. Our data shows that working mothers’ abilities to follow up with their children decreased. This study recommends that there is need to invest more in working mothers’ research and supportive programs and ensure collaboration globally to address working mothers’ needs and share experiences.展开更多
The performance and efficiency of hydraulic excavators heavily depend on the design and optimization of their working devices.The working device,which consists of the boom,arm,and bucket,plays a crucial role in determ...The performance and efficiency of hydraulic excavators heavily depend on the design and optimization of their working devices.The working device,which consists of the boom,arm,and bucket,plays a crucial role in determining the machine's digging capacity,stability,and overall operational efficiency.This paper presents a comprehensive study on the dynamics simulation and optimization of hydraulic excavator working devices.The paper outlines the fundamental principles of dynamic modeling,incorporating multi-body dynamics and hydraulic system analysis.It further explores various simulation techniques to evaluate the performance of the working device under varying operational conditions,including load and hydraulic system effects.The study also addresses performance optimization,focusing on multi-objective optimization methods that balance multiple factors such as energy efficiency,speed,and load capacity.Additionally,the paper discusses key factors influencing performance,such as mechanical design,material properties,and operational conditions.The results of the dynamic simulations and optimization analyses demonstrate potential improvements in operational efficiency and system stability,providing a valuable framework for the design and enhancement of hydraulic excavator working devices.展开更多
Social working memory(SWM)—the ability to maintain and manipulate social information in the brain—plays a crucial role in social interactions.However,research on SWM is still in its infancy and is often treated as a...Social working memory(SWM)—the ability to maintain and manipulate social information in the brain—plays a crucial role in social interactions.However,research on SWM is still in its infancy and is often treated as a unitary construct.In the present study,we propose that SWM can be conceptualized as having two relatively independent components:"externally oriented SWM"(e-SWM)and"internally oriented SWM"(i-SWM).To test this external–internal hypothesis,participants were tasked with memorizing and ranking either facial expressions(e-SWM)or personality traits(i-SWM)associated with images of faces.We then examined the neural correlates of these two SWM components and their functional roles in empathy.The results showed distinct activations as the e-SWM task activated the postcentral and precentral gyri while the i-SWM task activated the precuneus/posterior cingulate cortex and superior frontal gyrus.Distinct multivariate activation patterns were also found within the dorsal medial prefrontal cortex in the two tasks.Moreover,partial least squares analyses combining brain activation and individual differences in empathy showed that e-SWM and i-SWM brain activities were mainly correlated with affective empathy and cognitive empathy,respectively.These findings implicate distinct brain processes as well as functional roles of the two types of SWM,providing support for the internal–external hypothesis of SWM.展开更多
文摘The working group on design and evaluation of intelligent system ergonomics,under SAC/TC 7,Ergonomics,was officially established in Qingdao city,Shandong province on June 18.The launching ceremony was jointly organized by the Sub-institute of Fundamental Standardization of CNIS and China Standard Certification Co.,Ltd.It was attended by more than 60 experts and industry representatives in fields such as smart home technology,intelligent driving,wearable devices,medical health,and nuclear engineering.
基金Supported by Shanghai Municipal Health Commission’s Special Clinical Research Project for the Hygiene Industry,No.20244Y0041Youth Initiation Fund of Naval Medical University,No.2023QN028 and No.2023QN030。
文摘BACKGROUND Working memory serves as a fundamental cognitive function that substantially impacts performance in various cognitive tasks.Extensive neurophysiological research has established that theta oscillations(4-8 Hz)play an essential role in supporting working memory operations.Theta-band transcranial alternating current stimulation(tACS)offers a potential mechanism for working memory enhancement through direct modulation of these fundamental neural oscillations.Nevertheless,current empirical evidence shows substantial variability in the observed effects of theta-tACS across studies.AIM To conduct a systematic review and meta-analysis evaluating the effects of thetatACS on working memory performance in healthy adults.METHODS A systematic literature search was performed on PubMed,EMBASE,and Web of Science up to March 10,2025.Effect sizes were computed using Hedges’g with 95%confidence intervals(CIs),with separate meta-analyses for all included studies and for distinct working memory paradigms[n-back and delayed matchto-sample(DMTS)tasks]to examine potential task-specific effects.Subgroup analyses and meta-regression were performed to evaluate the influence of key moderating variables.RESULTS The systematic review included 21 studies(67 effect sizes).Initial meta-analysis showed theta-tACS moderately improved working memory(Hedges’g=0.405,95%CI:0.212-0.598).However,this effect became nonsignificant after correcting for publication bias(trim-and-fill adjusted Hedges’g=0.082,95%CI:-0.052 to 0.217).Task-specific analyses revealed significant benefits in n-back tasks(Hedges’g=0.463,95%CI:0.193-0.733)but not in DMTS tasks(Hedges’g=0.257,95%CI:-0.186 to 0.553).Moderator analyses showed that performance in n-back tasks was influenced by stimulation frequency(P=0.001),concurrent status(P=0.014),task modality(P=0.005),and duration(P=0.013),whereas only the region of targeted stimulation(P=0.012)moderated DMTS tasks.CONCLUSION Theta-tACS enhances working memory in healthy adults,with effects modulated by the task type and protocol parameters,offering dual implications for cognitive enhancement and clinical interventions.
基金funded by the China National Administration of Coal Geology Science and Technology Innovation Project"Research on Clean Energy Exploration and Development Technology"(ZMKJ-2021-ZX04)the China National Administration of Coal Geology Special Task Project"Research on Geothermal Resource Exploration and Development Technology"(ZMKJ-2023-JBGS06)。
文摘The optimization of working fluids in single-well coaxial geothermal systems presents a critical pathway for advancing the use of enhanced geothermal systems(EGS)in renewable energy applications.This study evaluates the thermo-hydraulic performance of three working fluids(H_(2)O,CO_(2),and H_(2))in a single-well coaxial geothermal system,focusing on the effects of their injection temperatures.Using a 3D finite element model in COMSOL Multiphysics,simulations were conducted at three injection temperatures(17℃,27℃,40℃)under constant mass flow rates.The results reveal that hydrogen significantly outperforms water and carbon dioxide,achieving a 297.77% and 5453.76% higher thermal output,respectively.Notably,the heat transfer efficiency is significantly improved when the injected working fluids are at 40℃,compared to 27℃;this demonstrates a positive correlation between injection temperature and thermal recovery.Though water systems exhibit better geological compatibility,the superior thermal properties of hydrogen position it as a promising alternative-despite potential subsurface challenges.This study provides critical insights for advancing the application of high-efficiency geothermal systems as well as the development of non-aqueous working fluids,thus contributing to the sustainable utilization of geothermal energy.
基金Supported by the National Natural Science Foundation of China(No.62203390).
文摘This paper is concerned with a non-intrusive anomaly detection method for carving machine systems with variant working conditions,and a novel unsupervised detection framework that integrates convolutional autoencoder(CAE)and Gaussian mixture hidden Markov model(GMHMM)is proposed.Firstly,the built-in sensor information under normal conditions is recorded,and a 1D convolutional autoencoder is employed to compress high-dimensional time series,thereby transforming the anomaly detection problem in high-dimensional space into a density estimation problem in a latent low-dimensional space.Then,two separate estimation networks are utilized to predict the mixture memberships and state transition probabilities for each sample,enabling GMHMM to handle low-dimensional representations and multi-condition information.Furthermore,a cost function comprising CAE reconstruction and GMHMM probability assessment is constructed for the low-dimensional representation generation and subsequent density estimation in an end-to-end fashion,and the joint optimization effectively enhances the anomaly detection performance.Finally,experiments are carried out on a self-developed multi-axis carving machine platform to validate the effectiveness and superiority of the proposed method.
文摘BACKGROUND There has been an increasing focus in recent years on health-care disparities.Studies investigating return to work(RTW)or sports are often performed in large,urban areas.Relatively few studies have investigated rates of return to farming or other heavy labor that is of interest to patients in rural areas.AIM To evaluate the literature regarding RTW in farming or heavy labor after orthopedic hip,knee,or shoulder surgery.METHODS A search was performed in the PubMed and EMBASE databases using Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines.Studies were included if they reported patients employed in farming or heavy labor,RTW rates after orthopedic surgery of the hip,knee,or shoulder,and had a minimum 6-month follow-up.A meta-analysis of proportions using a random-effects model was performed on three single-arm observational studies to estimate the pooled RTW rate following arthroscopic shoulder surgery.RESULTS Ten studies were included,and 101 farmers were identified among 440 total patients.One study involved hip surgery,two studies involved knee surgery,and seven studies involved shoulder surgery.RTW rates across studies varied by type of surgery and follow-up interval,ranging from 24%to 100%.The RTW rate was only 53.6%at 1 year following total hip arthroplasty.No studies investigated RTW in farmers following total knee arthroplasty.Among non-comparative studies,meta-analysis revealed a pooled RTW rate of 89%following arthroscopic shoulder surgery,with low heterogeneity(I^(2)=30.1%).Among comparative studies,one study reported significantly higher RTW odds for patients undergoing anatomic total shoulder arthroplasty compared to reverse shoulder arthroplasty(odds ratio=5.45).Overall,surgical intervention for shoulder pathology was associated with a high likelihood of RTW across multiple techniques,with particularly favorable outcomes for anatomic total shoulder arthroplasty.CONCLUSION This systematic review highlights the high rates of RTW in farmers and heavy laborers after shoulder surgery.However,our findings also underscore the need for more rural-specific research to guide patient counseling,rehabilitation expectations,and shared decision-making in this underserved population,particularly for orthopedic surgery of the hip and knee.
文摘The submersible pumping unit is a new type of pumping system for lifting formation fluids from onshore oil wells, and the identification of its working condition has an important influence on oil production. In this paper we proposed a diagnostic method for identifying the working condition of the submersible pumping system. Based on analyzing the working principle of the pumping unit and the pump structure, different characteristics in loading and unloading processes of the submersible linear motor were obtained at different working conditions. The characteristic quantities were extracted from operation data of the submersible linear motor. A diagnostic model based on the support vector machine （SVM） method was proposed for identifying the working condition of the submersible pumping unit, where the inputs of the SVM classifier were the characteristic quantities. The performance and the misjudgment rate of this method were analyzed and validated by the data acquired from an experimental simulation platform. The model proposed had an excellent performance in failure diagnosis of the submersible pumping system. The SVM classifier had higher diagnostic accuracy than the learning vector quantization （LVQ） classifier.
基金supported by the Instrument Developing Project of the Chinese Academy of Sciences(YZ201540)the National Science Foundation for Distinguished Young Scholars of China(31525010)+4 种基金the General Program of the National Science Foundation of China(31471049)the Key Research Project of Frontier Science of the Chinese Academy of Sciences(QYZDB-SSW-SMC009)China–Netherlands CAS-NWO Programme:Joint Research Projects,The Future of Brain and Cognition(153D31KYSB20160106)the Key Project of Shanghai Science and Technology Commission(15JC1400102,16JC1400101)the State Key Laboratory of Neuroscience,China
文摘Effcient behavioral assays are crucial for understanding the neural mechanisms of cognitive functions.Here, we designed a high-throughput automatic training system for spatial cognition(HASS) for free-moving mice.Mice were trained to return to the home arm and remain there during a delay period. Software was designed to enable automatic training in all its phases, including habituation, shaping, and learning. Using this system, we trained mice to successfully perform a spatially delayed nonmatch to sample task, which tested spatial cognition,working memory, and decision making. Performance depended on the delay duration, which is a hallmark of working memory tasks. The HASS enabled a human operator to train more than six mice simultaneously with minimal intervention, therefore greatly enhancing experimental efficiency and minimizing stress to the mice.Combined with the optogenetic method and neurophysiological techniques, the HASS will be useful in deciphering the neural circuitry underlying spatial cognition.
基金supported in part by the National Natural Science Foundation of China under Grant U1908212,62203432 and 92067205in part by the State Key Laboratory of Robotics of China under Grant 2023-Z03 and 2023-Z15in part by the Natural Science Foundation of Liaoning Province under Grant 2020-KF-11-02.
文摘The accurate and intelligent identification of the working conditions of a sucker-rod pumping system is necessary. As onshore oil extraction gradually enters its mid-to late-stage, the cost required to train a deep learning working condition recognition model for pumping wells by obtaining enough new working condition samples is expensive. For the few-shot problem and large calculation issues of new working conditions of oil wells, a working condition recognition method for pumping unit wells based on a 4-dimensional time-frequency signature (4D-TFS) and meta-learning convolutional shrinkage neural network (ML-CSNN) is proposed. First, the measured pumping unit well workup data are converted into 4D-TFS data, and the initial feature extraction task is performed while compressing the data. Subsequently, a convolutional shrinkage neural network (CSNN) with a specific structure that can ablate low-frequency features is designed to extract working conditions features. Finally, a meta-learning fine-tuning framework for learning the network parameters that are susceptible to task changes is merged into the CSNN to solve the few-shot issue. The results of the experiments demonstrate that the trained ML-CSNN has good recognition accuracy and generalization ability for few-shot working condition recognition. More specifically, in the case of lower computational complexity, only few-shot samples are needed to fine-tune the network parameters, and the model can be quickly adapted to new classes of well conditions.
基金We would like to thank the associate editor and the reviewers for their constructive comments.This work was supported in part by the National Natural Science Foundation of China under Grant 62203234in part by the State Key Laboratory of Robotics of China under Grant 2023-Z03+1 种基金in part by the Natural Science Foundation of Liaoning Province under Grant 2023-BS-025in part by the Research Program of Liaoning Liaohe Laboratory under Grant LLL23ZZ-02-02.
文摘High-precision and real-time diagnosis of sucker rod pumping system(SRPS)is important for quickly mastering oil well operations.Deep learning-based method for classifying the dynamometer card(DC)of oil wells is an efficient diagnosis method.However,the input of the DC as a two-dimensional image into the deep learning framework suffers from low feature utilization and high computational effort.Additionally,different SRPSs in an oil field have various system parameters,and the same SRPS generates different DCs at different moments.Thus,there is heterogeneity in field data,which can dramatically impair the diagnostic accuracy.To solve the above problems,a working condition recognition method based on 4-segment time-frequency signature matrix(4S-TFSM)and deep learning is presented in this paper.First,the 4-segment time-frequency signature(4S-TFS)method that can reduce the computing power requirements is proposed for feature extraction of DC data.Subsequently,the 4S-TFSM is constructed by relative normalization and matrix calculation to synthesize the features of multiple data and solve the problem of data heterogeneity.Finally,a convolutional neural network(CNN),one of the deep learning frameworks,is used to determine the functioning conditions based on the 4S-TFSM.Experiments on field data verify that the proposed diagnostic method based on 4S-TFSM and CNN(4S-TFSM-CNN)can significantly improve the accuracy of working condition recognition with lower computational cost.To the best of our knowledge,this is the first work to discuss the effect of data heterogeneity on the working condition recognition performance of SRPS.
基金Project (2012AA053001) supported by High-tech Research and Development Program of China
文摘For efficient utilization of a limited geothermal resource in practical projects,the cycle parameters were comprehensively analyzed by combining with the heat transfer performance of the plate heat exchanger,with a variation of flowrate of R245 fa.The influence of working fluid flowrate on a 500 W ORC system was investigated.Adjusting the working fluid flowrate to an optimal value results in the most efficient heat transfer and hence the optimal heat transfer parameters of the plate heat exchanger can be determined.Therefore,for the ORC systems,optimal working fluid flowrate should be controlled.Using different temperature hot water as the heat source,it is found that the optimal flowrate increases by 6-10 L/h with 5 ℃ increment of hot water inlet temperature.During experiment,lower degree of superheat of the working fluid at the outlet the plate heat exchanger may lead to unstable power generation.It is considered that the plate heat exchanger has a compact construction which makes its bulk so small that liquid mixture causes the unstable power generation.To avoid this phenomenon,the flow area of plate heat exchanger should be larger than the designed one.Alternatively,installing a small shell and tube heat exchanger between the outlet of plate heat exchanger and the inlet of expander can be another solution.
文摘In order to develop the technology of the controlled recircuIation of airflow in the world, some formulas about the airflow recirculation system in the working face with leaking airflow are deduced,which reduces the error between calculating and real values. on the base of the application of the formulas mentioned above, the problem about lack of airflow in the working face 2712 was solved successfully in Xiandewang Coal Mine.
文摘The difficult problem of automatically welding nipples onto the header is first analyzed in this paper, and then the overall structure and operating principle of the robot working unit are introduced. The robot and the measuring device are located by employing the traveling lorry, and this unit enables the robot to adjust the tracks according to the errors received from the measuring device, and then the nipples are welded properly. This paper emphases on the development of the master-slave control system, in which the prograrmmable Logic Controller (PLC) is used as the master computer.
基金the National Natural Science Foundation of China(No.51776115)the Shandong Province Graduate Student Supervisor Guidance Ability Promotion Program(No.SDYY17037)the Shandong Univeisity uf 3uieuue ad Teuluulugy Giauluale 3uusdent Supervisor Guidance Ability Promotion Program(No.KDYC17009)。
文摘The objective of this paper is to present a simulation study on the two-stage absorption refrigeration systems of 2.5 kW capacity using LiBr-H2O,NH3-H2O and R124-DMAC as working pairs.Under the design condition that the generating,absorbing,evaporating and condensing temperatures are 75℃,45℃,5℃and 40℃,respectively,the high and low pressure side solution circulation ratios and the coefficient of performance(COP)for the systems are calculated.Then the influences of medium,generating,absorbing,evaporating and condensing temperatures on system performances are analyzed.The results show that under the design condition,the COP of the LiBr-H2Osystem can reach 0.49,superior to those of the NH3-H2O and R124-DMAC systems,which are 0.32 and 0.31,respectively.Furthermore,the medium temperature for higher COP lies in an interval of 64-67℃for the LiBr-H2O.NH3-H2O and R124-DMAC systems.High generating temperature and low absorbing temperature can decrease the high and low pressure side solution circulation ratios,and can also increase the COP.High evaporating temperature can decrease the low pressure side solution circulation ratio and increase the COP.Low condensing temperature can decrease the high pressure side solution circulation ratio and increase the COP.
文摘Solid adsorption system, one of alternative refrigeration systems, is utilized to provide cold for refrigerator or air-conditioner and can be operated by assistance of solar heat. System performance study through computer usage to develop simulation program and simulate behaviors of system operation can give designed system which suits for user’s need. Also, the present study aims to develop dynamic simulation program of solid adsorption refrigeration system operated by solar assistance to simulate behaviors of system operation and its performance. Flat plate collectror is utilized to provide thermal energy for system’s adsorber and activated carbon/methanol is used to be a suitable working pair. Simulation procedure starts with various solar radiation intensities as input energy on solar collector and water is used as collector working fluid. Behavior of system operation can be considered to be 4 steps as isosteric heating, isobaric desorption, isosteric cooling and isobaric adsorption, respectively. This research studies the effect of varying solar radiation intensity on temperature, pressure of adsorber, adsorption ratio at each steps of system operated ranging from 6:00 am (the first day) to 6:00 am (the next day) and system performance which is defined as coefficient of performance, COP. In addition, the simulation result shows monthly average COP of 0.43 compared to a result of another previous research work under the same operating condition and the percentage error is 7.5%.
基金supported by the Russian Science Foundation(grant number 20-19-00226).
文摘One of the effective options for energy saving in terms of heat costs for the formation of routine thermal conditions of working areas of large-sized industrial premises is the replacement of traditional convective(water)heating systems with systems,the main part of which are gas infrared emitters.But the mass introduction of such systems based on emitters was held back until recently by the lack of scientific and technical foundations for ensuring not only the routine thermal conditions of local working areas,but also ensuring acceptable concentrations of carbon dioxide,which is formed during the operation of a gas emitter.Solving the latter problem by the method of experimental selection of heating and air exchange modes is practically impossible due to the multivariate nature of possible solutions to this problem.Therefore,the purpose of the work is to analyze the results of theoretical studies of the possibility of ensuring an acceptable level of carbon dioxide concentrations in local working areas during the operation of gas infrared emitters and an air exchange system.Numerical modeling of heat and mass transfer processes under such conditions was performed in a fairly wide range of the main significant factors:air flow rate in the air exchange system from 0.01 to 0.04 kg/s,the position of the air inlet and outlet channels relative to the radiator and the local workplace(height from 0.3 to 4.1 m).It was found that by varying the numerical values of these factors,it is possible to ensure carbon dioxide concentrations in the local working area within the permissible limits of up to 1400 ppm.
文摘The design philosophy based on the working process systematization, the feature of practice teaching is analyzed the principles of practice teaching quality evaluation system are summed up. The evaluation system based on working process systematization of the practice teaching quality is established, the management of quality evaluation system and the project of the monitoring are put forward.
文摘With the civilization and modernization of human society,occupational health has emerged as a fundamental goal of social justice,as highlighted in the United Nations'Sustainable Development Goals(SDGs)since 2016.Specifically,"SDG Goal 1:No Poverty","SDG 3:Good Health and Well-being",and"SDG 8:Decent Work and Economic Growth",are interconnected with other SDGs to support the pursuit of occupational health.
文摘Coronavirus is a Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) caused by a novel coronavirus belonging to the family Coronaviridae. The disease was first discovered in December 2019 in Wuhan City, Hubei Province, China. A few months later, the disease spread all over the world and became an epidemic. The infection for most people is mild to moderate but in Vulnerable groups, if they have the infections, they might experience severe COVID-19. Saudi Arabia initiated its response plan early, and all sectors and agencies worked in an integrated way to combat the disease. It has maintained proper communication during the pandemic and ensured community involvement, epidemiologic surveillance, and activation of rapid response teams. The COVID-19 pandemic significantly affected daily lives. Schools and daycares were closed, education was online, traveling stopped, work was suspended, gathering in social activities and practicing religious rituals, like praying or doing Umrah or Hajj, were banded. Changing lifestyles as a response to COVID-19 impacted whole communities with different categories of children, parents, and families. Women usually take the majority of daily responsibilities. The sudden change in lifestyle during COVID-19 put pressure on mothers, especially those who are working to balance work and family obligations. This study aims to identify the impact of Coronavirus disease 2019 on working mothers in Saudi Arabia. Method: Data of the study was collected through survey posted on social media and analyzed through Excel. It focuses on five aspects: health, lifestyle, social relations, work production and financial status. Our target population was working mothers in Saudi Arabia aged at least 25 years. Results: In this study, all factors affected working mothers categorized under two groups: Social Economic Status and Work suspension. For Social Economic Status factors, we find five factors which are monthly income, main breadwinner, number of children at school age, type of housing, and type of work. Almost all mothers include spiritual activities to their routine to cope with stress during this period. About half of our sample have negative impact on their mental health because they are the main breadwinner, and mothers with a smaller number of children at school age have more challenges to cope up. We found that mothers who own a house or work at governmental sector have better outcome of health. After analyzing data related to Work suspension, we found that mothers who have work support have better management for life circumstances, however their health outcomes were negatively affected. In addition, mothers working at education sector have the highest positive impact among other sectors. Our data shows that working mothers’ abilities to follow up with their children decreased. This study recommends that there is need to invest more in working mothers’ research and supportive programs and ensure collaboration globally to address working mothers’ needs and share experiences.
文摘The performance and efficiency of hydraulic excavators heavily depend on the design and optimization of their working devices.The working device,which consists of the boom,arm,and bucket,plays a crucial role in determining the machine's digging capacity,stability,and overall operational efficiency.This paper presents a comprehensive study on the dynamics simulation and optimization of hydraulic excavator working devices.The paper outlines the fundamental principles of dynamic modeling,incorporating multi-body dynamics and hydraulic system analysis.It further explores various simulation techniques to evaluate the performance of the working device under varying operational conditions,including load and hydraulic system effects.The study also addresses performance optimization,focusing on multi-objective optimization methods that balance multiple factors such as energy efficiency,speed,and load capacity.Additionally,the paper discusses key factors influencing performance,such as mechanical design,material properties,and operational conditions.The results of the dynamic simulations and optimization analyses demonstrate potential improvements in operational efficiency and system stability,providing a valuable framework for the design and enhancement of hydraulic excavator working devices.
基金supported by the Key Program of Natural Science Foundation of Zhejiang Province(LZ20C090001)the National Natural Science Foundation of China(32271090,32171031,and 32071044)the China Brain Project(2021ZD0200409).
文摘Social working memory(SWM)—the ability to maintain and manipulate social information in the brain—plays a crucial role in social interactions.However,research on SWM is still in its infancy and is often treated as a unitary construct.In the present study,we propose that SWM can be conceptualized as having two relatively independent components:"externally oriented SWM"(e-SWM)and"internally oriented SWM"(i-SWM).To test this external–internal hypothesis,participants were tasked with memorizing and ranking either facial expressions(e-SWM)or personality traits(i-SWM)associated with images of faces.We then examined the neural correlates of these two SWM components and their functional roles in empathy.The results showed distinct activations as the e-SWM task activated the postcentral and precentral gyri while the i-SWM task activated the precuneus/posterior cingulate cortex and superior frontal gyrus.Distinct multivariate activation patterns were also found within the dorsal medial prefrontal cortex in the two tasks.Moreover,partial least squares analyses combining brain activation and individual differences in empathy showed that e-SWM and i-SWM brain activities were mainly correlated with affective empathy and cognitive empathy,respectively.These findings implicate distinct brain processes as well as functional roles of the two types of SWM,providing support for the internal–external hypothesis of SWM.
