If an explicit time scheme is used in a numerical model, the size of the integration time step is typically limited by the spatial resolution. This study develops a regular latitude–longitude grid-based global three-...If an explicit time scheme is used in a numerical model, the size of the integration time step is typically limited by the spatial resolution. This study develops a regular latitude–longitude grid-based global three-dimensional tracer transport model that is computationally stable at large time-step sizes. The tracer model employs a finite-volume flux-form semiLagrangian transport scheme in the horizontal and an adaptively implicit algorithm in the vertical. The horizontal and vertical solvers are coupled via a straightforward operator-splitting technique. Both the finite-volume scheme's onedimensional slope-limiter and the adaptively implicit vertical solver's first-order upwind scheme enforce monotonicity. The tracer model permits a large time-step size and is inherently conservative and monotonic. Idealized advection test cases demonstrate that the three-dimensional transport model performs very well in terms of accuracy, stability, and efficiency. It is possible to use this robust transport model in a global atmospheric dynamical core.展开更多
BACKGROUND Traditional methods cannot clearly visualize esophageal cancer(EC)tumor contours and metastases,which limits the clinical application of da Vinci robotassisted surgery.AIM To investigate the efficacy of the...BACKGROUND Traditional methods cannot clearly visualize esophageal cancer(EC)tumor contours and metastases,which limits the clinical application of da Vinci robotassisted surgery.AIM To investigate the efficacy of the da Vinci robot in combination with nanocarbon lymph node tracers in radical surgery of EC.METHODS In total,104 patients with early-stage EC who were admitted to Liuzhou worker's Hospital from January 2020 to June 2023 were enrolled.The patients were assigned to an observation group(n=52),which underwent da Vinci robot-assisted minimally invasive esophagectomy(RAMIE)with the intraoperative use of nanocarbon tracers,and a control group(n=52),which underwent traditional surgery treatment.The operation time,intraoperative blood loss,postoperative drainage tube indwelling time,hospital stay,number of lymph nodes dissected,incidence of complications,and long-term curative effects were comparatively analyzed.The postoperative stress response C-reactive protein(CRP),cortisol,epinephrine(E)and inflammatory response interleukin(IL)-6,IL-8,IL-10,and tumor necrosis factor-alpha(TNF-α)were evaluated.RESULTS Compared with the control group,the observation group had significantly lower postoperative CRP,cortisol,and E levels(P<0.05)with a milder inflammatory response,as indicated by lower IL-6,IL-10,and TNF-αlevels(P<0.05).Patients who underwent RAMIE had less intraoperative blood loss and shorter operation times and hospital stays than those who underwent traditional surgery.The average number of dissected lymph nodes,time of lymph node dissection,and mean smallest lymph node diameter were all significantly lower in the observation group(P<0.05).The rate of postoperative complications was 5.77%in the observation group,significantly lower than the 15.38%observed in the control group.Furthermore,the lymphatic metastasis rate,reoperation rate,and 12-and 24-month cumulative mortality in the observation group were 1.92%,0%,0%,and 0%,respectively,all of which were significantly lower than those in the control group(P<0.05).CONCLUSION The treatment of EC using the da Vinci robot combined with nanocarbon lymph node tracers can achieve good surgical outcomes and demonstrates promising clinical applications.展开更多
Over 100,000,000 people worldwide are exposed to high arsenic groundwater utilised for drinking or cooking.The consequent global avoidable disease burden is estimated to be of the order of 100,000 avoidable deaths or ...Over 100,000,000 people worldwide are exposed to high arsenic groundwater utilised for drinking or cooking.The consequent global avoidable disease burden is estimated to be of the order of 100,000 avoidable deaths or more per annum from just direct exposures - i.e.excluding indirect exposure (from rice and other foods) and excluding morbidity.Notwithstanding 1000s of papers published on arsenic (hydro)(bio)geochemistry,there remain a number of key outstanding questions to be addressed in relation to arsenic geoscience - these include questions related to:(i) the role of human activities - irrigation,agriculture and other land uses - on arsenic mobilisation in groundwaters;(ii) the specific sources,nature and role of organics,minerals and microbial communities involved in arsenic mobilisation;(iii) the relationship to microscopic to macroscopic scale geological (including tectonic) and evolution processes;(iv) unravelling the over-printing of multiple processes in complex highly heterogeneous aquifer systems and (v) using increasing understanding of the controls of arsenic mobility in groundwaters systems to informing improved locally-relevant remediation and mitigation approaches.This article further summarises how the 9 further papers in this Special Issue address some of these questions through the use of chemical and/or isotopic tracers.展开更多
Design and implementation of Internet of Things (IoT) systems require platforms with smart things and components. Two dominant architectural approaches for developing IoT systems are mashup-based and model-based appro...Design and implementation of Internet of Things (IoT) systems require platforms with smart things and components. Two dominant architectural approaches for developing IoT systems are mashup-based and model-based approaches. Mashup approaches use existing services and are mainly suitable for less critical, personalized applications. Web development tools are widely used in mashup approaches. Model-based techniques describe a system on a higher level of abstraction, resulting in very expressive modelling of systems. The article uses Cisco packet tracer 7.2 version, which consists of four subcategories of smart things—home, smart city, industrial and power grid, to design an IoT based control system for a fertilizer manufacturing plant. The packet tracer also consists of boards—microcontrollers (MCU-PT), and single boarded computers (SBC-PT), as well as actuators and sensors. The model facilitates flexible communication opportunities among things—machines, databases, and Human Machine Interfaces (HMIs). Implementation of the IoT system brings finer process control as the operating conditions are monitored online and are broadcasted to all stakeholders in real-time for quicker action on deviations. The model developed focuses on three process plants;steam raising, nitric acid, and ammonium nitrate plants. Key process parameters are saturated steam temperature, fuel flowrates, CO and SO<sub>x</sub> emissions, converter head temperature, NO<sub>x</sub> emissions, neutralisation temperature, solution temperature, and evaporator steam pressure. The parameters need to be monitored in order to ensure quality, safety, and efficiency. Through the Cisco packet tracer platform, a use case, physical layout, network layout, IoT layout, configuration, and simulation interface were developed.展开更多
HALOGENS are typical mineralizer elements and play a very important role in remobilization and resettlement of the ore-forming mental elements in the hydrothermal deposits. Studies of tracer system on halogens mineral...HALOGENS are typical mineralizer elements and play a very important role in remobilization and resettlement of the ore-forming mental elements in the hydrothermal deposits. Studies of tracer system on halogens mineralizer include the following aspects: (i) halogens’ role as mineralizer in ore-forming action;(ii) halogens importance as tracer elements in formation and evolution of the epithermal ore deposit;(iii) halogens’ significance as guidance in looking for the buried orebodies. Guizhou is a concentrated area of epithermal Hg, Sb and Au deposits, where are distributed famousepithermal deposits such as the Wanshan Hg deposit, the Banpo Sb deposit, the Danzhai Hg-Au depositand the Lannigou Au deposit. Many researches into geological and geochemical characteristics of thesedeposits have been done, but few study on halogen mineralizer.展开更多
Nitrogen fixation is one of the most important sources of new nitrogen in the ocean and thus profoundly affects the nitrogen and carbon biogeochemical processes.The distribution,controlling factors,and flux of N2 fixa...Nitrogen fixation is one of the most important sources of new nitrogen in the ocean and thus profoundly affects the nitrogen and carbon biogeochemical processes.The distribution,controlling factors,and flux of N2 fixation in the global ocean remain uncertain,partly because of the lack of methodological uniformity.The^(15)N_(2)tracer assay(the original bubble method→the^(15)N_(2)-enriched seawater method→the modified bubble method)is the mainstream method for field measurements of N2 fixation rates(NFRs),among which the original bubble method is the most frequently used.However,accumulating evidence has suggested an underestimation of NFRs when using this method.To improve the availability of previous data,we compared NFRs measured by three^(15)N_(2)tracer assays in the South China Sea.Our results indicate that the relationship between NFRs measured by the original bubble method and the^(15)N_(2)-enriched seawater method varies obviously with area and season,which may be influenced by incubation time,diazotrophic composition,and environmental factors.In comparison,the relationship between NFRs measured by the original bubble method and the modified bubble method is more stable,indicating that the N2 fixation rates based on the original bubble methods may be underestimated by approximately 50%.Based on this result,we revised the flux of N2 fixation in the South China Sea to 40 mmol/(m2·a).Our results improve the availability and comparability of literature NFR data in the South China Sea.The comparison of the^(15)N_(2)tracer assay for NFRs measurements on a larger scale is urgently necessary over the global ocean for a more robust understanding of the role of N2 fixation in the marine nitrogen cycle.展开更多
The tracer technique is recommended as an effective tool in surveying abnormal seepage through lakes and dams. By injecting a tracer into a known upstream location and monitoring the appearance of the tracer in the do...The tracer technique is recommended as an effective tool in surveying abnormal seepage through lakes and dams. By injecting a tracer into a known upstream location and monitoring the appearance of the tracer in the downstream leak point, it is possible to determine the direction and the average water velocity of the preferential flow through the dam. The detailed result achieved depends on the number of samples and the sampling locations to analyze tracer concentration over time in the field. This study proposes to use noninvasive self-potential measurements to determine the location and time the salt tracer moves through the seepage zone. The connection between the potential signal according to the propagation of the NaCl salt tracer and the water velocity was demonstrated through an experiment on a sandbox model. Experimental results express a good agreement between the time to reach the maximum value of the potential variation and the salt concentration variation with the time that water comes to monitoring locations. The result indicates an ability to determine the pore water velocity of the seepage zone based on the recording of potential signals produced by a salt tracer movement. The salt tracer test using NaCl combined with self-potential measurements was then applied to survey a leaking earth dam in the Dong Nai river basin (Vietnam).展开更多
study was carried out on the transfer of native and added Ni towards plant both in different soils andat different time by using ￣(63)Ni tracer technique. The transfer of added Ni in soil was greater than native Nian...study was carried out on the transfer of native and added Ni towards plant both in different soils andat different time by using ￣(63)Ni tracer technique. The transfer of added Ni in soil was greater than native Niand declined as time increased. The mobility was greater for soluble plus exchangeable fraction of soil Nibut very smaller for residual and Fe/Mn oxide bound fractions. These indicated that Ni was more mobileand more harmful in soils with a low pH and/or low content of Fe/Mn oxides.展开更多
The mechanism that controls regional mineralization must be governed by a seriesof geochemical reactions in relation to the source system of magmatism. In this respect, the geological bodies must have been overprinted...The mechanism that controls regional mineralization must be governed by a seriesof geochemical reactions in relation to the source system of magmatism. In this respect, the geological bodies must have been overprinted by various kinds of tracers in terms of either chemical elements or isotopes. For this reason, the problem may be better approached by treating thelithosphere as a whole with due considerations given to the various tracer elements and isotopesand the various media of the magmatism (magmatic as well as sedimentary rocks). Presentedin this paper are the results of this attempt based on a great wealth of available data concerningthe source system of Mesozoic magmatism in the Middle and Lower Yangtze Valleys and adjacent areas.展开更多
基金jointly supported by the National Natural Science Foundation of China (Grant No.42075153)the Young Scientists Fund of the Earth System Modeling and Prediction Centre (Grant No. CEMC-QNJJ-2022014)。
文摘If an explicit time scheme is used in a numerical model, the size of the integration time step is typically limited by the spatial resolution. This study develops a regular latitude–longitude grid-based global three-dimensional tracer transport model that is computationally stable at large time-step sizes. The tracer model employs a finite-volume flux-form semiLagrangian transport scheme in the horizontal and an adaptively implicit algorithm in the vertical. The horizontal and vertical solvers are coupled via a straightforward operator-splitting technique. Both the finite-volume scheme's onedimensional slope-limiter and the adaptively implicit vertical solver's first-order upwind scheme enforce monotonicity. The tracer model permits a large time-step size and is inherently conservative and monotonic. Idealized advection test cases demonstrate that the three-dimensional transport model performs very well in terms of accuracy, stability, and efficiency. It is possible to use this robust transport model in a global atmospheric dynamical core.
基金Supported by Guangxi Health Department Scientific Research Program,No.Z20200206Project of Guangxi Liuzhou Science and Technology Bureau,No.2024YB0101B010。
文摘BACKGROUND Traditional methods cannot clearly visualize esophageal cancer(EC)tumor contours and metastases,which limits the clinical application of da Vinci robotassisted surgery.AIM To investigate the efficacy of the da Vinci robot in combination with nanocarbon lymph node tracers in radical surgery of EC.METHODS In total,104 patients with early-stage EC who were admitted to Liuzhou worker's Hospital from January 2020 to June 2023 were enrolled.The patients were assigned to an observation group(n=52),which underwent da Vinci robot-assisted minimally invasive esophagectomy(RAMIE)with the intraoperative use of nanocarbon tracers,and a control group(n=52),which underwent traditional surgery treatment.The operation time,intraoperative blood loss,postoperative drainage tube indwelling time,hospital stay,number of lymph nodes dissected,incidence of complications,and long-term curative effects were comparatively analyzed.The postoperative stress response C-reactive protein(CRP),cortisol,epinephrine(E)and inflammatory response interleukin(IL)-6,IL-8,IL-10,and tumor necrosis factor-alpha(TNF-α)were evaluated.RESULTS Compared with the control group,the observation group had significantly lower postoperative CRP,cortisol,and E levels(P<0.05)with a milder inflammatory response,as indicated by lower IL-6,IL-10,and TNF-αlevels(P<0.05).Patients who underwent RAMIE had less intraoperative blood loss and shorter operation times and hospital stays than those who underwent traditional surgery.The average number of dissected lymph nodes,time of lymph node dissection,and mean smallest lymph node diameter were all significantly lower in the observation group(P<0.05).The rate of postoperative complications was 5.77%in the observation group,significantly lower than the 15.38%observed in the control group.Furthermore,the lymphatic metastasis rate,reoperation rate,and 12-and 24-month cumulative mortality in the observation group were 1.92%,0%,0%,and 0%,respectively,all of which were significantly lower than those in the control group(P<0.05).CONCLUSION The treatment of EC using the da Vinci robot combined with nanocarbon lymph node tracers can achieve good surgical outcomes and demonstrates promising clinical applications.
基金support from EPSRC (GR/S30207/01)NERC(NE/ J023833/1, NE/P01304X/1)+2 种基金DST-NERC-Newton Bhabha(NE/ R003386/1)(FAR-GANGA)the British Council (SA07/09) (UKIERI PRAMA)the European Union(MRTN-CT-2006-035420, KH/ Asia-Link/04 142966)
文摘Over 100,000,000 people worldwide are exposed to high arsenic groundwater utilised for drinking or cooking.The consequent global avoidable disease burden is estimated to be of the order of 100,000 avoidable deaths or more per annum from just direct exposures - i.e.excluding indirect exposure (from rice and other foods) and excluding morbidity.Notwithstanding 1000s of papers published on arsenic (hydro)(bio)geochemistry,there remain a number of key outstanding questions to be addressed in relation to arsenic geoscience - these include questions related to:(i) the role of human activities - irrigation,agriculture and other land uses - on arsenic mobilisation in groundwaters;(ii) the specific sources,nature and role of organics,minerals and microbial communities involved in arsenic mobilisation;(iii) the relationship to microscopic to macroscopic scale geological (including tectonic) and evolution processes;(iv) unravelling the over-printing of multiple processes in complex highly heterogeneous aquifer systems and (v) using increasing understanding of the controls of arsenic mobility in groundwaters systems to informing improved locally-relevant remediation and mitigation approaches.This article further summarises how the 9 further papers in this Special Issue address some of these questions through the use of chemical and/or isotopic tracers.
文摘Design and implementation of Internet of Things (IoT) systems require platforms with smart things and components. Two dominant architectural approaches for developing IoT systems are mashup-based and model-based approaches. Mashup approaches use existing services and are mainly suitable for less critical, personalized applications. Web development tools are widely used in mashup approaches. Model-based techniques describe a system on a higher level of abstraction, resulting in very expressive modelling of systems. The article uses Cisco packet tracer 7.2 version, which consists of four subcategories of smart things—home, smart city, industrial and power grid, to design an IoT based control system for a fertilizer manufacturing plant. The packet tracer also consists of boards—microcontrollers (MCU-PT), and single boarded computers (SBC-PT), as well as actuators and sensors. The model facilitates flexible communication opportunities among things—machines, databases, and Human Machine Interfaces (HMIs). Implementation of the IoT system brings finer process control as the operating conditions are monitored online and are broadcasted to all stakeholders in real-time for quicker action on deviations. The model developed focuses on three process plants;steam raising, nitric acid, and ammonium nitrate plants. Key process parameters are saturated steam temperature, fuel flowrates, CO and SO<sub>x</sub> emissions, converter head temperature, NO<sub>x</sub> emissions, neutralisation temperature, solution temperature, and evaporator steam pressure. The parameters need to be monitored in order to ensure quality, safety, and efficiency. Through the Cisco packet tracer platform, a use case, physical layout, network layout, IoT layout, configuration, and simulation interface were developed.
文摘HALOGENS are typical mineralizer elements and play a very important role in remobilization and resettlement of the ore-forming mental elements in the hydrothermal deposits. Studies of tracer system on halogens mineralizer include the following aspects: (i) halogens’ role as mineralizer in ore-forming action;(ii) halogens importance as tracer elements in formation and evolution of the epithermal ore deposit;(iii) halogens’ significance as guidance in looking for the buried orebodies. Guizhou is a concentrated area of epithermal Hg, Sb and Au deposits, where are distributed famousepithermal deposits such as the Wanshan Hg deposit, the Banpo Sb deposit, the Danzhai Hg-Au depositand the Lannigou Au deposit. Many researches into geological and geochemical characteristics of thesedeposits have been done, but few study on halogen mineralizer.
基金The National Natural Science Foundation of China under contract Nos 42076042 and 41721005the Fund of Ministry of Science and Technology of China under contract No.2017FY201403the Fund of China Ocean Mineral Resources R&D Association under contract No.DY135-13-E2-03.
文摘Nitrogen fixation is one of the most important sources of new nitrogen in the ocean and thus profoundly affects the nitrogen and carbon biogeochemical processes.The distribution,controlling factors,and flux of N2 fixation in the global ocean remain uncertain,partly because of the lack of methodological uniformity.The^(15)N_(2)tracer assay(the original bubble method→the^(15)N_(2)-enriched seawater method→the modified bubble method)is the mainstream method for field measurements of N2 fixation rates(NFRs),among which the original bubble method is the most frequently used.However,accumulating evidence has suggested an underestimation of NFRs when using this method.To improve the availability of previous data,we compared NFRs measured by three^(15)N_(2)tracer assays in the South China Sea.Our results indicate that the relationship between NFRs measured by the original bubble method and the^(15)N_(2)-enriched seawater method varies obviously with area and season,which may be influenced by incubation time,diazotrophic composition,and environmental factors.In comparison,the relationship between NFRs measured by the original bubble method and the modified bubble method is more stable,indicating that the N2 fixation rates based on the original bubble methods may be underestimated by approximately 50%.Based on this result,we revised the flux of N2 fixation in the South China Sea to 40 mmol/(m2·a).Our results improve the availability and comparability of literature NFR data in the South China Sea.The comparison of the^(15)N_(2)tracer assay for NFRs measurements on a larger scale is urgently necessary over the global ocean for a more robust understanding of the role of N2 fixation in the marine nitrogen cycle.
文摘The tracer technique is recommended as an effective tool in surveying abnormal seepage through lakes and dams. By injecting a tracer into a known upstream location and monitoring the appearance of the tracer in the downstream leak point, it is possible to determine the direction and the average water velocity of the preferential flow through the dam. The detailed result achieved depends on the number of samples and the sampling locations to analyze tracer concentration over time in the field. This study proposes to use noninvasive self-potential measurements to determine the location and time the salt tracer moves through the seepage zone. The connection between the potential signal according to the propagation of the NaCl salt tracer and the water velocity was demonstrated through an experiment on a sandbox model. Experimental results express a good agreement between the time to reach the maximum value of the potential variation and the salt concentration variation with the time that water comes to monitoring locations. The result indicates an ability to determine the pore water velocity of the seepage zone based on the recording of potential signals produced by a salt tracer movement. The salt tracer test using NaCl combined with self-potential measurements was then applied to survey a leaking earth dam in the Dong Nai river basin (Vietnam).
文摘study was carried out on the transfer of native and added Ni towards plant both in different soils andat different time by using ￣(63)Ni tracer technique. The transfer of added Ni in soil was greater than native Niand declined as time increased. The mobility was greater for soluble plus exchangeable fraction of soil Nibut very smaller for residual and Fe/Mn oxide bound fractions. These indicated that Ni was more mobileand more harmful in soils with a low pH and/or low content of Fe/Mn oxides.
文摘The mechanism that controls regional mineralization must be governed by a seriesof geochemical reactions in relation to the source system of magmatism. In this respect, the geological bodies must have been overprinted by various kinds of tracers in terms of either chemical elements or isotopes. For this reason, the problem may be better approached by treating thelithosphere as a whole with due considerations given to the various tracer elements and isotopesand the various media of the magmatism (magmatic as well as sedimentary rocks). Presentedin this paper are the results of this attempt based on a great wealth of available data concerningthe source system of Mesozoic magmatism in the Middle and Lower Yangtze Valleys and adjacent areas.
