BACKGROUND Cerebral infarction,previously referred to as cerebral infarction or ischemic stroke,refers to the localized brain tissue experiencing ischemic necrosis or softening due to disorders in brain blood supply,i...BACKGROUND Cerebral infarction,previously referred to as cerebral infarction or ischemic stroke,refers to the localized brain tissue experiencing ischemic necrosis or softening due to disorders in brain blood supply,ischemia,and hypoxia.The precision rehabilitation nursing model for chronic disease management is a continuous,fixed,orderly,and efficient nursing model aimed at standardizing the clinical nursing process,reducing the wastage of medical resources,and improving the quality of medical services.AIM To analyze the value of a precise rehabilitation nursing model for chronic disease management in patients with cerebral infarction.METHODS Patients(n=124)admitted to our hospital with cerebral infarction between November 2019 and November 2021 were enrolled as the study subjects.The random number table method was used to divide them into a conventional nursing intervention group(n=61)and a model nursing intervention group(n=63).Changes in the nursing index for the two groups were compared after conventional nursing intervention and precise rehabilitation intervention nursing for chronic disease management.RESULTS Compared with the conventional intervention group,the model intervention group had a shorter time to clinical symptom relief(P<0.05),lower Hamilton Anxiety Scale and Hamilton Depression Scale scores,a lower incidence of total complications(P<0.05),a higher disease knowledge mastery rate,higher safety and quality,and a higher overall nursing satisfaction rate(P<0.05).CONCLUSION The precision rehabilitation nursing model for chronic disease management improves the clinical symptoms of patients with cerebral infarction,reducing the incidence of total complications and improving the clinical outcome of patients,and is worthy of application in clinical practice.展开更多
The effects of selected land management practices （cross-sloping tillage, ridge culture, organic manure, and straw mulch） on soil water conservation in a southwestern mountainous area, China, were studied during Nov...The effects of selected land management practices （cross-sloping tillage, ridge culture, organic manure, and straw mulch） on soil water conservation in a southwestern mountainous area, China, were studied during November 2002 to November 2004. The experimental field is divided into three parts based on soil layer depths, 0-60 cm （part Ⅰ）, 0-40 cm （part Ⅱ）, and 0- 20 cm （part Ⅲ）, and they all had the same slope azimuth （SE）, slope （10°）, and slope type （linear）. The experimental plots were subjected to the following treatments： cross-sloping tillage （CST）; cross-sloping tillage with organic manure （CST/ OM）; cross-sloping tillage with straw mulch （CST/SM）; contour ridge culture （CRC）; contour ridge culture with organic manure （CRC/OM）; and contour ridge culture with straw mulch （CRC/SM）, to identify the effects of management practices on soil water. Water contents were determined for soil samples collected, using a 2.2 cm diameter manual probe. Soil water was monitored once every five days from Nov. 20, 2002 to Nov. 20, 2004. The results indicated that, in the study stages, an integration of rainfall, evaporative losses, and crop transcription controlled the basic tendencies of profile （mean） soil water, while land management practices, to a certain extent, only modified its amount, distribution, and routing. Moreover, these modifications also mainly focused on the first 20 cm depth of topsoil layer. When each management practice was compared with control treatment, season changes of profile （mean） soil water were pronounced, while interannual changes among them were not significant. More comparisons indicated that, in the study stages, contour ridge culture had better effects than cross-sloping tillage. And under the same tillage, the combination of organic manure could achieve more than straw mulch. These management practices should be recommended considering the effectiveness of soil and water management techniques in the southwestern mountainous area, China.展开更多
There is great heterogeneity among inflammatory bowel disease(IBD)patients in terms of pathogenesis,clinical manifestation,response to treatment,and prognosis,which requires the individualized and precision management...There is great heterogeneity among inflammatory bowel disease(IBD)patients in terms of pathogenesis,clinical manifestation,response to treatment,and prognosis,which requires the individualized and precision management of patients.Many studies have focused on prediction biomarkers and models for assessing IBD disease type,activity,severity,and prognosis.During the era of biologics,how to predict the response and side effects of patients to different treatments and how to quickly recognize the loss of response have also become important topics.Multiomics is a promising area for investigating the complex network of IBD pathogenesis.Integrating numerous amounts of data requires the use of artificial intelligence.展开更多
Hepatobiliary tumor (HBT), one of the leading causes of cancer deaths globally, is more frequent in East Asia including China [1].HBTincludeslivercancer,cholangiocarcinomaandgallbladder cancer.HBTburdenvariesmarkedlyb...Hepatobiliary tumor (HBT), one of the leading causes of cancer deaths globally, is more frequent in East Asia including China [1].HBTincludeslivercancer,cholangiocarcinomaandgallbladder cancer.HBTburdenvariesmarkedlybygenderandgeographic regionduetotheexposureofriskfactors.MajorityofthehepatocellularcarcinomasareassociatedwithhepatitisB-typevirus展开更多
In the Sichuan Basin,the drilling of complex deep and ultradeep wells is restricted by the casing sequence.Multiple pressure systems are usually encountered in the same open hole section,and narrow safety density wind...In the Sichuan Basin,the drilling of complex deep and ultradeep wells is restricted by the casing sequence.Multiple pressure systems are usually encountered in the same open hole section,and narrow safety density window is observed in vertical strata.The application of managed pressure drilling(MPD)technique which is often used in well drilling ensures the safe and efficient drilling,but it also brings about great challenges to the small-gap liner cementing at the lower part.Therefore,it is of great practical significance to research a cementing technology that can not only satisfy the quality requirement of small gap liner cementing,but also ensure the safe cementing in the strata with narrow safety density window.In this paper,a cementing technology based on precise managed pressure balancing method was proposed by referring to the successful application of MPD technique.According to the cementing design,the hydrostatic column pressure of annulusfluid is under-balanced(slightly lower than the formation pore pressure),and then a precise managed pressure drilling device is adopted to produce back pressure through wellhead restriction or apply wellhead compensation pressure,so that the balanced pore pressure can be reached in the process of cementing via the wellhead pressure and theflow friction offluid in the annulus.After the cementing is completed,a certain compensation pressure is applied to the annulus continuously to prevent annulus channeling during waiting on cement caused by insufficient static pressure and slurry weight loss.After this technology was applied to an ultradeep exploration well in the Sichuan Basin,the qualification rate of borehole cementing quality reached 97%,and the well sections with good cementing quality accounted for 76%.In conclusion,this technology needs no additional equipment,and only by virtue of the MPD equipment,it can achieve safe cementing construction and cementing quality improvement under high displacement efficiency.展开更多
Weed control in agricultural systems is of the utmost importance.Weeds reduce crop yields by up to 30%to 40%.Different methods are used to control weeds,such as manual,chemical,mechanical,and precision weed management...Weed control in agricultural systems is of the utmost importance.Weeds reduce crop yields by up to 30%to 40%.Different methods are used to control weeds,such as manual,chemical,mechanical,and precision weed management.Weeds are managed more effectively by using the hand weeding method,which nevertheless falls short due to the unavailability of labor during peak periods and increasing labor wages.Generally,manual weeding tools have higher weeding efficiency(72%to 99%)but lower field capacity(0.001 to 0.033 hm2/h).Use of chemicals to control weeds is the most efficient and cost-effective strategy.Chemical weedicides have been used excessively and inappropriately,which has over time resulted in many issues with food and environmental damage.Mechanical weed control improves soil aeration,increases water retention capacity,slows weed growth,and has no negative effects on plants.Mechanical weed management techniques have been gaining importance recently.Automation in agriculture has significantly enhanced mechanization inputs for weed management.The development of precision weed management techniques offers an efficient way to control weeds,contributing to greater sustainability and improved agricultural productivity.Devices for agricultural automated navigation have been built on the rapid deployment of sensors,microcontrollers,and computing technologies into the field.The automated system saves time and reduces labor requirements and health risks associated with drudgery,all of which contribute to more effective farm operations.The new era of agriculture demands highly efficient and effective autonomous weed control techniques.Methods such as remote sensing,multispectral and hyperspectral imaging,and the use of robots or UAVs(drones)can significantly reduce labor requirements,enhance food production speed,maintain crop quality,address ecological imbalances,and ensure the precise application of agrochemicals.Weed monitoring is made more effective and safer for the environment through integrated weed management and UAVs.In the future,weed control by UAV or robot will be two of the key solutions because they do not pollute the environment or cause plant damage,nor do they compact the soil,because UAV sprays above the ground and robotic machines are lighter than tractor operated machines.This paper aims to review conventional,chemical,mechanical,and precision weed management methods.展开更多
Modern international project management has entered the phase of precise and accurate project management after the global financial crisis broke out at the beginning of the 21 stcentury. However, its development has f...Modern international project management has entered the phase of precise and accurate project management after the global financial crisis broke out at the beginning of the 21 stcentury. However, its development has faced new challenges since there has been lack of explicitly unanimous definition for the capability dimensions of precise and accurate project management, as well as the models and their process control parameters. The required core capabilities based on the precise and accurate project management for various rings are involved in the project life cycle, namely, the required internationally core competences and their components for the phases of project strategic planning and decision making in the early project phase, as well as the value engineering, and the project supervision and controls during the execution phase.Through studying the effects of the internationally core competences based on precise and accurate project management capabilities for the success and excellence of projects and configuring such models, the goal is to help the main contractors continuously obtain project success and excellence, thus improve its internationally core competences with continuous project success and excellence.展开更多
The exploration and development of oil and gas resources in the Sichuan Basin is shifting to the deeper strata.The deep and ultra-deep wells in deep carbonate gas reservoirs are faced with many difficulties,such as mu...The exploration and development of oil and gas resources in the Sichuan Basin is shifting to the deeper strata.The deep and ultra-deep wells in deep carbonate gas reservoirs are faced with many difficulties,such as multiple pressure systems,poor drillability,ultra-high pressure,ultra-high temperature and high sulfur content,which bring great challenges to drilling and completion engineering.In order to ensure the smooth exploration and development of deep carbonate oil and gas resources in the Sichuan Basin,the overall concept of combiningfield practice and technological research is followed.During the 13th Five-Year Plan,a batch of ultra-deep wells(well depth about 8000 m)have been drilled fast and safely(such as Well SYX133 in the Shuangyushi structure),and great progresses have been achieved in the experimental research of the support technologies in drilling and completion of deep and ultra-deep wells.And the achievements are as follows.First,the optimization of non-standard well structure,combined with the application of precisely managed pressure drilling technology and under-pressure plugging technology,lays a foundation for the optimized fast drilling and the safe reaching of geological targets.Second,a high-efficiency customized PDC drill bit is comprehensively optimized,popularized and applied,which effectively improves the average rate of penetration(ROP)in difficult-to-drill formations.Third,the development and application of drillingfluids(e.g.being resistant to high temperature of 200 C and anti-composite brine)and active under-pressure plugging technology effectively reduces downhole complexities while drilling the complex for-mations,such as high temperature and high pressure brine and circulation loss.Fourth,when precisely managed pressure drilling and precisely managed pressure cementing methods are applied in the strata with a narrow density window,multiple pressure systems and pressure sensitivity,the average drilling and completionfluid loss is reduced by more than 90%,and the complexity treatment time is cut down by more than 85%,and the cementing quality pass rate is increased by more than 20%.Fifth,the integrated application of ROP improvement technologies and tools(e.g.air drilling)results in a great reduction of drilling cycle and cost.It is concluded that the experimental research achievements provide basic support for the fast development of natural gas resources in the Anyue Gas Field,Sichuan Basin,and the great discovery of the Permian and Devonian natural gas resources in the northwestern Sichuan Basin.What's more,in order to adapt to the development of the deep natural gas(over 9000 m)in the Sichuan Basin during the 14th Five-Year Plan,it is necessary to speed up researches on drilling and completion tech-nologies in nine aspects,e.g.high-temperature downhole tools and workingfluid.展开更多
Advanced lithography systems serve as the cornerstone of semiconductor manufacturing,facilitating the accurate patterning of nanoscale circuit features onto silicon substrates while defining state-of-the-art process t...Advanced lithography systems serve as the cornerstone of semiconductor manufacturing,facilitating the accurate patterning of nanoscale circuit features onto silicon substrates while defining state-of-the-art process technologies(e.g.,3 nm and 5 nm nodes).The development of these systems presents fundamental fluid dynamic challenges,encompassing multi-physics and multi-scale mechanics in plasma generation and transport,hydrodynamics of contaminant debris behavior and migration,and precise thermal management through fluid dynamics.This special topic features six contributions from leading researchers,offering contemporary perspectives on fluid mechanical phenomena in advanced lithography technologies.展开更多
This review aims to gain insight into the current research and application of operational management in the area of intelligent agriculture based on the Internet of Things(IoT),and consequently,identify existing short...This review aims to gain insight into the current research and application of operational management in the area of intelligent agriculture based on the Internet of Things(IoT),and consequently,identify existing shortcomings and potential issues.First,we use the Java application CiteSpace to analyze co-citation networks in the literature related to the operational management of IoT-based intelligent agriculture.From the literature analysis results,we identify three major fields:(1)the development of agricultural IoT(Agri-IoT)technology,(2)the precision management of agricultural production,and(3)the traceability management of agricultural products.Second,we review research in the three fields separately in detail.Third,on the basis of the research gaps identified in the review and from the perspective of integrating and upgrading the entire agricultural industry chain,additional research directions are recommended from the following aspects:The operational management of agricultural production,product processing,and product sale and after-sale service based on Agri-IoT.The theoretical research and practical application of combining operational management theories and IoT-based intelligent agriculture will provide informed decision support for stakeholders and drive the further development of the entire agriculture industry chain.展开更多
Precision energy management is very important for sustainability development of solar greenhouses,since huge energy demand for agricultural production both in quantity and quality.A proactive energy management,accordi...Precision energy management is very important for sustainability development of solar greenhouses,since huge energy demand for agricultural production both in quantity and quality.A proactive energy management,according to the optimal energy utilization in a look-ahead period with weather prediction,is presented and tested in this research.A multi-input-multi-output linear model of the energy balance of solar greenhouses based on on-line identification system can simulate greenhouse behavior and allow for predictive control.The good time allocation of available solar energy can be achieved by intelligent use of controls,such as store/retrieve fans and ventilation windows,i.e.solar energy to warm up the air or to be stored in the storage elements(wall,soil,etc.)or to be exhausted to outside.The proactive energy management can select an optimal trajectory of air temperature for the forecasted weather period to minimize plants’thermal‘cost’defined by an‘expert’in terms of set-points for the specific crop.The selection of temperature trajectory is formulated as a generalized traveling salesman problem(GTSP)with precedence constraints and is solved by a genetic algorithm(GA)in this research.The simulation study showed good potential for energy saving and timely allocation to prevent excessive crop stress.The active control elements in addition to predefining and applying,within energy constraints,optimal climate in the greenhouse,it also reduces the energy deficit,i.e.the working hours of the‘heater’in the sustained freezing weather,as well as the ventilation hours,that is,more energy harvest in the warm days.This intelligent solar greenhouse management system is being migrated to the web for serving a‘customer base’in the Internet Plus era.The capacity,of the concrete ground CAUA system(CAUA is an abbreviations from both China Agricultural University and Agricultural University of Athens),to implement web‘updates’of criteria,open weather data and models,on which control actions are based,is what makes use of Cloud Data for closing the loop of an effective Internet of Things(IoT)system,based on MACQU(MAnagement and Control for QUality)technological platform.展开更多
The nondestructive and rapid acquisition of rice field phenotyping information is very important for the precision management of the rice growth process.In this research,the phenotyping information LAI(leaf area index...The nondestructive and rapid acquisition of rice field phenotyping information is very important for the precision management of the rice growth process.In this research,the phenotyping information LAI(leaf area index),leaf chlorophyll content(C_(ab)),canopy water content(C_(w)),and dry matter content(C_(dm))of rice was inversed based on the hyperspectral remote sensing technology of an unmanned aerial vehicle(UAV).The improved Sobol global sensitivity analysis(GSA)method was used to analyze the input parameters of the PROSAIL model in the spectral band range of 400-1100 nm,which was obtained by hyperspectral remote sensing by the UAV.The results show that C_(ab) mainly affects the spectrum on 400-780 nm band,C_(dm) on 760-1000 nm band,C_(w) on 900-1100 nm band,and LAI on the entire band.The hyperspectral data of the 400-1100 nm band of the rice canopy were acquired by using the M600 UAV remote sensing platform,and the radiance calibration was converted to the canopy emission rate.In combination with the PROSAIL model,the particle swarm optimization algorithm was used to retrieve rice phenotyping information by constructing the cost function.The results showed the following:(1)an accuracy of R^(2)=0.833 and RMSE=0.0969,where RMSE denotes root-mean-square error,was obtained for C_(ab) retrieval;R^(2)=0.816 and RMSE=0.1012 for LAI inversion;R^(2)=0.793 and RMSE=0.1084 for C_(dm);and R^(2)=0.665 and RMSE=0.1325 for C_(w).The C_(w) inversion accuracy was not particularly high.(2)The same band will be affected by multiple parameters at the same time.(3)This study adopted the rice phenotyping information inversion method to expand the rice hyperspectral information acquisition field of a UAV based on the phenotypic information retrieval accuracy using a high level of field spectral radiometric accuracy.The inversion method featured a good mechanism,high universality,and easy implementation,which can provide a reference for nondestructive and rapid inversion of rice biochemical parameters using UAV hyperspectral remote sensing.展开更多
文摘BACKGROUND Cerebral infarction,previously referred to as cerebral infarction or ischemic stroke,refers to the localized brain tissue experiencing ischemic necrosis or softening due to disorders in brain blood supply,ischemia,and hypoxia.The precision rehabilitation nursing model for chronic disease management is a continuous,fixed,orderly,and efficient nursing model aimed at standardizing the clinical nursing process,reducing the wastage of medical resources,and improving the quality of medical services.AIM To analyze the value of a precise rehabilitation nursing model for chronic disease management in patients with cerebral infarction.METHODS Patients(n=124)admitted to our hospital with cerebral infarction between November 2019 and November 2021 were enrolled as the study subjects.The random number table method was used to divide them into a conventional nursing intervention group(n=61)and a model nursing intervention group(n=63).Changes in the nursing index for the two groups were compared after conventional nursing intervention and precise rehabilitation intervention nursing for chronic disease management.RESULTS Compared with the conventional intervention group,the model intervention group had a shorter time to clinical symptom relief(P<0.05),lower Hamilton Anxiety Scale and Hamilton Depression Scale scores,a lower incidence of total complications(P<0.05),a higher disease knowledge mastery rate,higher safety and quality,and a higher overall nursing satisfaction rate(P<0.05).CONCLUSION The precision rehabilitation nursing model for chronic disease management improves the clinical symptoms of patients with cerebral infarction,reducing the incidence of total complications and improving the clinical outcome of patients,and is worthy of application in clinical practice.
文摘The effects of selected land management practices （cross-sloping tillage, ridge culture, organic manure, and straw mulch） on soil water conservation in a southwestern mountainous area, China, were studied during November 2002 to November 2004. The experimental field is divided into three parts based on soil layer depths, 0-60 cm （part Ⅰ）, 0-40 cm （part Ⅱ）, and 0- 20 cm （part Ⅲ）, and they all had the same slope azimuth （SE）, slope （10°）, and slope type （linear）. The experimental plots were subjected to the following treatments： cross-sloping tillage （CST）; cross-sloping tillage with organic manure （CST/ OM）; cross-sloping tillage with straw mulch （CST/SM）; contour ridge culture （CRC）; contour ridge culture with organic manure （CRC/OM）; and contour ridge culture with straw mulch （CRC/SM）, to identify the effects of management practices on soil water. Water contents were determined for soil samples collected, using a 2.2 cm diameter manual probe. Soil water was monitored once every five days from Nov. 20, 2002 to Nov. 20, 2004. The results indicated that, in the study stages, an integration of rainfall, evaporative losses, and crop transcription controlled the basic tendencies of profile （mean） soil water, while land management practices, to a certain extent, only modified its amount, distribution, and routing. Moreover, these modifications also mainly focused on the first 20 cm depth of topsoil layer. When each management practice was compared with control treatment, season changes of profile （mean） soil water were pronounced, while interannual changes among them were not significant. More comparisons indicated that, in the study stages, contour ridge culture had better effects than cross-sloping tillage. And under the same tillage, the combination of organic manure could achieve more than straw mulch. These management practices should be recommended considering the effectiveness of soil and water management techniques in the southwestern mountainous area, China.
基金the Youth Program of National Natural Science Foundation of China,No.82000526the National High Level Hospital Clinical Research Funding,No.2022-PUMCH-A-072the National College Students’Innovation and Entrepreneurship Training Program,No.2022zglc06083.
文摘There is great heterogeneity among inflammatory bowel disease(IBD)patients in terms of pathogenesis,clinical manifestation,response to treatment,and prognosis,which requires the individualized and precision management of patients.Many studies have focused on prediction biomarkers and models for assessing IBD disease type,activity,severity,and prognosis.During the era of biologics,how to predict the response and side effects of patients to different treatments and how to quickly recognize the loss of response have also become important topics.Multiomics is a promising area for investigating the complex network of IBD pathogenesis.Integrating numerous amounts of data requires the use of artificial intelligence.
基金supported by grants from the “919 Tumor Pre-cision Medicine Public Welfare Foundation”the International Sci-ence and Technology Cooperation Projects(2015DFA30650 and 2016YFE0107100)+2 种基金Chinese Academy of Medical Sciences(CAMS) Innovation Fund for Medical Sciences(CIFMS)(2017-I2M-4-003)the Capital Special Research Project for the Clinical Application(Z151100004015170)Beijing Natural Science Foundation Haid-ian Joint Fund Frontier Project(L172055)
文摘Hepatobiliary tumor (HBT), one of the leading causes of cancer deaths globally, is more frequent in East Asia including China [1].HBTincludeslivercancer,cholangiocarcinomaandgallbladder cancer.HBTburdenvariesmarkedlybygenderandgeographic regionduetotheexposureofriskfactors.MajorityofthehepatocellularcarcinomasareassociatedwithhepatitisB-typevirus
基金supported by the National Major Science and Technology Project"Development demonstration project of large-scale carbonae gas fields in the Sichuan Basin-Research and application of large-scale deep carbonate gas reservoir drilling and production technology"(No:2016ZX05052-003)Pet roChina Major Science and Technology Project"Research and application of key technologies for maintaining 30billion cubic meters of natural gas production in Southwest Oil and Gas Field-Research and application ofdrilling,completion,and oil testing technologies for high temperature and high pressure sulfur-bearing deep wells in the Sichuan Basin"(No:2016E-0608)。
文摘In the Sichuan Basin,the drilling of complex deep and ultradeep wells is restricted by the casing sequence.Multiple pressure systems are usually encountered in the same open hole section,and narrow safety density window is observed in vertical strata.The application of managed pressure drilling(MPD)technique which is often used in well drilling ensures the safe and efficient drilling,but it also brings about great challenges to the small-gap liner cementing at the lower part.Therefore,it is of great practical significance to research a cementing technology that can not only satisfy the quality requirement of small gap liner cementing,but also ensure the safe cementing in the strata with narrow safety density window.In this paper,a cementing technology based on precise managed pressure balancing method was proposed by referring to the successful application of MPD technique.According to the cementing design,the hydrostatic column pressure of annulusfluid is under-balanced(slightly lower than the formation pore pressure),and then a precise managed pressure drilling device is adopted to produce back pressure through wellhead restriction or apply wellhead compensation pressure,so that the balanced pore pressure can be reached in the process of cementing via the wellhead pressure and theflow friction offluid in the annulus.After the cementing is completed,a certain compensation pressure is applied to the annulus continuously to prevent annulus channeling during waiting on cement caused by insufficient static pressure and slurry weight loss.After this technology was applied to an ultradeep exploration well in the Sichuan Basin,the qualification rate of borehole cementing quality reached 97%,and the well sections with good cementing quality accounted for 76%.In conclusion,this technology needs no additional equipment,and only by virtue of the MPD equipment,it can achieve safe cementing construction and cementing quality improvement under high displacement efficiency.
基金financially supported by the Deanship of Scientific Research,Vice Presidency for Graduate Studies and Scientific Research,King Faisal University,Saudi Arabia(Grant No.KFU250115).
文摘Weed control in agricultural systems is of the utmost importance.Weeds reduce crop yields by up to 30%to 40%.Different methods are used to control weeds,such as manual,chemical,mechanical,and precision weed management.Weeds are managed more effectively by using the hand weeding method,which nevertheless falls short due to the unavailability of labor during peak periods and increasing labor wages.Generally,manual weeding tools have higher weeding efficiency(72%to 99%)but lower field capacity(0.001 to 0.033 hm2/h).Use of chemicals to control weeds is the most efficient and cost-effective strategy.Chemical weedicides have been used excessively and inappropriately,which has over time resulted in many issues with food and environmental damage.Mechanical weed control improves soil aeration,increases water retention capacity,slows weed growth,and has no negative effects on plants.Mechanical weed management techniques have been gaining importance recently.Automation in agriculture has significantly enhanced mechanization inputs for weed management.The development of precision weed management techniques offers an efficient way to control weeds,contributing to greater sustainability and improved agricultural productivity.Devices for agricultural automated navigation have been built on the rapid deployment of sensors,microcontrollers,and computing technologies into the field.The automated system saves time and reduces labor requirements and health risks associated with drudgery,all of which contribute to more effective farm operations.The new era of agriculture demands highly efficient and effective autonomous weed control techniques.Methods such as remote sensing,multispectral and hyperspectral imaging,and the use of robots or UAVs(drones)can significantly reduce labor requirements,enhance food production speed,maintain crop quality,address ecological imbalances,and ensure the precise application of agrochemicals.Weed monitoring is made more effective and safer for the environment through integrated weed management and UAVs.In the future,weed control by UAV or robot will be two of the key solutions because they do not pollute the environment or cause plant damage,nor do they compact the soil,because UAV sprays above the ground and robotic machines are lighter than tractor operated machines.This paper aims to review conventional,chemical,mechanical,and precision weed management methods.
文摘Modern international project management has entered the phase of precise and accurate project management after the global financial crisis broke out at the beginning of the 21 stcentury. However, its development has faced new challenges since there has been lack of explicitly unanimous definition for the capability dimensions of precise and accurate project management, as well as the models and their process control parameters. The required core capabilities based on the precise and accurate project management for various rings are involved in the project life cycle, namely, the required internationally core competences and their components for the phases of project strategic planning and decision making in the early project phase, as well as the value engineering, and the project supervision and controls during the execution phase.Through studying the effects of the internationally core competences based on precise and accurate project management capabilities for the success and excellence of projects and configuring such models, the goal is to help the main contractors continuously obtain project success and excellence, thus improve its internationally core competences with continuous project success and excellence.
基金supported by the National Research Council of Science and Technology Major Project“Sichuan Basin Large-scale Carbonate Cas Fiekd Development Demonstration Project”(No.:2016ZX05052).
文摘The exploration and development of oil and gas resources in the Sichuan Basin is shifting to the deeper strata.The deep and ultra-deep wells in deep carbonate gas reservoirs are faced with many difficulties,such as multiple pressure systems,poor drillability,ultra-high pressure,ultra-high temperature and high sulfur content,which bring great challenges to drilling and completion engineering.In order to ensure the smooth exploration and development of deep carbonate oil and gas resources in the Sichuan Basin,the overall concept of combiningfield practice and technological research is followed.During the 13th Five-Year Plan,a batch of ultra-deep wells(well depth about 8000 m)have been drilled fast and safely(such as Well SYX133 in the Shuangyushi structure),and great progresses have been achieved in the experimental research of the support technologies in drilling and completion of deep and ultra-deep wells.And the achievements are as follows.First,the optimization of non-standard well structure,combined with the application of precisely managed pressure drilling technology and under-pressure plugging technology,lays a foundation for the optimized fast drilling and the safe reaching of geological targets.Second,a high-efficiency customized PDC drill bit is comprehensively optimized,popularized and applied,which effectively improves the average rate of penetration(ROP)in difficult-to-drill formations.Third,the development and application of drillingfluids(e.g.being resistant to high temperature of 200 C and anti-composite brine)and active under-pressure plugging technology effectively reduces downhole complexities while drilling the complex for-mations,such as high temperature and high pressure brine and circulation loss.Fourth,when precisely managed pressure drilling and precisely managed pressure cementing methods are applied in the strata with a narrow density window,multiple pressure systems and pressure sensitivity,the average drilling and completionfluid loss is reduced by more than 90%,and the complexity treatment time is cut down by more than 85%,and the cementing quality pass rate is increased by more than 20%.Fifth,the integrated application of ROP improvement technologies and tools(e.g.air drilling)results in a great reduction of drilling cycle and cost.It is concluded that the experimental research achievements provide basic support for the fast development of natural gas resources in the Anyue Gas Field,Sichuan Basin,and the great discovery of the Permian and Devonian natural gas resources in the northwestern Sichuan Basin.What's more,in order to adapt to the development of the deep natural gas(over 9000 m)in the Sichuan Basin during the 14th Five-Year Plan,it is necessary to speed up researches on drilling and completion tech-nologies in nine aspects,e.g.high-temperature downhole tools and workingfluid.
文摘Advanced lithography systems serve as the cornerstone of semiconductor manufacturing,facilitating the accurate patterning of nanoscale circuit features onto silicon substrates while defining state-of-the-art process technologies(e.g.,3 nm and 5 nm nodes).The development of these systems presents fundamental fluid dynamic challenges,encompassing multi-physics and multi-scale mechanics in plasma generation and transport,hydrodynamics of contaminant debris behavior and migration,and precise thermal management through fluid dynamics.This special topic features six contributions from leading researchers,offering contemporary perspectives on fluid mechanical phenomena in advanced lithography technologies.
基金This work was supported by grants from the Natural Science Foundation of China Key Project(Grant No.71531002)Innovative Group Project(Grant No.71421001)General Project(Grant No.71571027).
文摘This review aims to gain insight into the current research and application of operational management in the area of intelligent agriculture based on the Internet of Things(IoT),and consequently,identify existing shortcomings and potential issues.First,we use the Java application CiteSpace to analyze co-citation networks in the literature related to the operational management of IoT-based intelligent agriculture.From the literature analysis results,we identify three major fields:(1)the development of agricultural IoT(Agri-IoT)technology,(2)the precision management of agricultural production,and(3)the traceability management of agricultural products.Second,we review research in the three fields separately in detail.Third,on the basis of the research gaps identified in the review and from the perspective of integrating and upgrading the entire agricultural industry chain,additional research directions are recommended from the following aspects:The operational management of agricultural production,product processing,and product sale and after-sale service based on Agri-IoT.The theoretical research and practical application of combining operational management theories and IoT-based intelligent agriculture will provide informed decision support for stakeholders and drive the further development of the entire agriculture industry chain.
基金This research was supported by the National Key Research and Development Program of China(2016YED0201003)the Yunnan Academician Expert Workstation(Wang Maohua,Grant No.2015IC16)。
文摘Precision energy management is very important for sustainability development of solar greenhouses,since huge energy demand for agricultural production both in quantity and quality.A proactive energy management,according to the optimal energy utilization in a look-ahead period with weather prediction,is presented and tested in this research.A multi-input-multi-output linear model of the energy balance of solar greenhouses based on on-line identification system can simulate greenhouse behavior and allow for predictive control.The good time allocation of available solar energy can be achieved by intelligent use of controls,such as store/retrieve fans and ventilation windows,i.e.solar energy to warm up the air or to be stored in the storage elements(wall,soil,etc.)or to be exhausted to outside.The proactive energy management can select an optimal trajectory of air temperature for the forecasted weather period to minimize plants’thermal‘cost’defined by an‘expert’in terms of set-points for the specific crop.The selection of temperature trajectory is formulated as a generalized traveling salesman problem(GTSP)with precedence constraints and is solved by a genetic algorithm(GA)in this research.The simulation study showed good potential for energy saving and timely allocation to prevent excessive crop stress.The active control elements in addition to predefining and applying,within energy constraints,optimal climate in the greenhouse,it also reduces the energy deficit,i.e.the working hours of the‘heater’in the sustained freezing weather,as well as the ventilation hours,that is,more energy harvest in the warm days.This intelligent solar greenhouse management system is being migrated to the web for serving a‘customer base’in the Internet Plus era.The capacity,of the concrete ground CAUA system(CAUA is an abbreviations from both China Agricultural University and Agricultural University of Athens),to implement web‘updates’of criteria,open weather data and models,on which control actions are based,is what makes use of Cloud Data for closing the loop of an effective Internet of Things(IoT)system,based on MACQU(MAnagement and Control for QUality)technological platform.
基金support of the National Key Research and Development Plan of China(Grant No.2016YFD020060307)Key Project of Education Department of Liaoning province(LSNZD201605).
文摘The nondestructive and rapid acquisition of rice field phenotyping information is very important for the precision management of the rice growth process.In this research,the phenotyping information LAI(leaf area index),leaf chlorophyll content(C_(ab)),canopy water content(C_(w)),and dry matter content(C_(dm))of rice was inversed based on the hyperspectral remote sensing technology of an unmanned aerial vehicle(UAV).The improved Sobol global sensitivity analysis(GSA)method was used to analyze the input parameters of the PROSAIL model in the spectral band range of 400-1100 nm,which was obtained by hyperspectral remote sensing by the UAV.The results show that C_(ab) mainly affects the spectrum on 400-780 nm band,C_(dm) on 760-1000 nm band,C_(w) on 900-1100 nm band,and LAI on the entire band.The hyperspectral data of the 400-1100 nm band of the rice canopy were acquired by using the M600 UAV remote sensing platform,and the radiance calibration was converted to the canopy emission rate.In combination with the PROSAIL model,the particle swarm optimization algorithm was used to retrieve rice phenotyping information by constructing the cost function.The results showed the following:(1)an accuracy of R^(2)=0.833 and RMSE=0.0969,where RMSE denotes root-mean-square error,was obtained for C_(ab) retrieval;R^(2)=0.816 and RMSE=0.1012 for LAI inversion;R^(2)=0.793 and RMSE=0.1084 for C_(dm);and R^(2)=0.665 and RMSE=0.1325 for C_(w).The C_(w) inversion accuracy was not particularly high.(2)The same band will be affected by multiple parameters at the same time.(3)This study adopted the rice phenotyping information inversion method to expand the rice hyperspectral information acquisition field of a UAV based on the phenotypic information retrieval accuracy using a high level of field spectral radiometric accuracy.The inversion method featured a good mechanism,high universality,and easy implementation,which can provide a reference for nondestructive and rapid inversion of rice biochemical parameters using UAV hyperspectral remote sensing.
