Numerical study on scanning radiation acoustic field in formations generated by linear phased array transmitters in a fluid-filled borehole is carried out using a real axis integration (RAI) method. The main lobe widt...Numerical study on scanning radiation acoustic field in formations generated by linear phased array transmitters in a fluid-filled borehole is carried out using a real axis integration (RAI) method. The main lobe width of the acoustic beams and the incident angle on the borehole wall can be controlled by means of adjusting parameters, such as the element number and the delay time between the neighboring array elements of linear phased array transmitter. The steered angle of longitudinal waves generated in the formation satisfies the Snell’s law for plane waves when the incident angle on the borehole wall is less than the first critical angle. When the lobe width of the acoustic beams is narrow and the steered angle is less than the first critical angle, the acoustic field in the formation can be approximately calculated given that the linear phased array is put in the formation without borehole. The technique of scanning radiation acoustic field can be applied to enhancing investigation resolution and signal-to-noise ratio in crosswell seismic survey and borehole acoustic reflection imaging.展开更多
Electromagnetic railgun attracts more and more attention due to its advantage in speed,cost,and obscurity.It is found that the rail should withstand huge mechanical and thermal shocks during the launching operation.Th...Electromagnetic railgun attracts more and more attention due to its advantage in speed,cost,and obscurity.It is found that the rail should withstand huge mechanical and thermal shocks during the launching operation.The forms of rail failure are accompanied by gouge,grooving,transition,and arc ablation,etc.The service life of the rail has become a bottleneck restricting the development of electromagnetic railgun technology.A series of researches are carried out to solve rail failure,including analysing the failure mechanism and using various advanced rail materials.This paper provides a comprehensive review of rail materials,including material composition,preparation,microstructure,and properties.We begin from a short background of the requirement of the rail material.Then a detailed investigation of rail materials is described,and the performances of those materials are introduced.Finally,further development prospect of rail material is discussed.展开更多
Climate is subject to fluctuations in the majority of the world, mainly caused by rainfall as well as temperature variations. Climate fluctuations in Kenya have resulted in the spread of desert-like conditions in the ...Climate is subject to fluctuations in the majority of the world, mainly caused by rainfall as well as temperature variations. Climate fluctuations in Kenya have resulted in the spread of desert-like conditions in the ASALs region, such as Marigat in Baringo County. As a county, Baringo experiences great variations in climate annually, as well as uncertainty in expected rains, thereby negatively impacting the production of crops such as sorghum. This study applied the rainfall anomaly index (RAI), standardised precipitation evapotranspiration index (SPEI), standard precipitation index (SPI), and Mann-Kendall (MK) statistical test for trends on historical climatic data in analysing both temperature and precipitation data over the period 1990 to 2022 to determine their trend, patterns and how they affect the production of sorghum crops. The machine learning method (R studio) with inputs was used to calculate the SPI, SPEI, RAI and MK trend test. The rainfall varied from below average to above average during the study period with no clear pattern in the RAI, SPEI and SPI values. The years 2020 and 2000 stood out as they had higher and lower rainfall than usual, respectively. The Marigat area generally experienced more rainfall during the high/long rainfall season (AMJJ). The MK trend test on average monthly rainfall, SOND, AMJJ, and annual precipitation confirmed a positive trend in precipitation. However, the short rainy season (SOND) was found to be the most variable period for rainfall, and there was a slight increase in daily average temperatures during this season.展开更多
Objective: Patients with radioactive iodine-refractory differentiated thyroid cancer(RAIR-DTC) are often diagnosed with delay and constrained to limited treatment options. The correlation between RAI refractoriness an...Objective: Patients with radioactive iodine-refractory differentiated thyroid cancer(RAIR-DTC) are often diagnosed with delay and constrained to limited treatment options. The correlation between RAI refractoriness and the underlying genetic characteristics has not been extensively studied.Methods: Adult patients with distant metastatic DTC were enrolled and assigned to undergo next-generation sequencing of a customized 26-gene panel(Thyro Lead). Patients were classified into RAIR-DTC or non-RAIR groups to determine the differences in clinicopathological and molecular characteristics. Molecular risk stratification(MRS) was constructed based on the association between molecular alterations identified and RAI refractoriness, and the results were classified as high, intermediate or low MRS.Results: A total of 220 patients with distant metastases were included, 63.2% of whom were identified as RAIRDTC. Genetic alterations were identified in 90% of all the patients, with BRAF(59.7% vs. 17.3%), TERT promoter(43.9% vs. 7.4%), and TP53 mutations(11.5% vs. 3.7%) being more prevalent in the RAIR-DTC group than in the non-RAIR group, except for RET fusions(15.8% vs. 39.5%), which had the opposite pattern. BRAF and TERT promoter are independent predictors of RAIR-DTC, accounting for 67.6% of patients with RAIR-DTC. MRS was strongly associated with RAI refractoriness(P<0.001), with an odds ratio(OR) of high to low MRS of 7.52 [95%confidence interval(95% CI), 3.96-14.28;P<0.001] and an OR of intermediate to low MRS of 3.20(95% CI,1.01-10.14;P=0.041).Conclusions: Molecular alterations were associated with RAI refractoriness, with BRAF and TERT promoter mutations being the predominant contributors, followed by TP53 and DICER1 mutations. MRS might serve as a valuable tool for both prognosticating clinical outcomes and directing precision-based therapeutic interventions.展开更多
The Tan Rai Bauxite Project, which exploits a large bauxite mine in Lam Dong province, Vietnam has been in operation since 2012. In addition to the economic efficiency of the project, bauxite mining and processing use...The Tan Rai Bauxite Project, which exploits a large bauxite mine in Lam Dong province, Vietnam has been in operation since 2012. In addition to the economic efficiency of the project, bauxite mining and processing uses a large area arable land and affect the regional environment. Remote sensing technology is increasingly widely used in many purposes in monitoring the changes of environment and resources, including land use change with high accuracy, giving managers more information to monitor the exploitation and use process of land resource. This study used a Change Vector Analysis (CVA) method of analysis on various remote sensing data sources to monitor the process of land exploitation and restoration of the Tan Rai Bauxite project. High-resolution remote sensing images were used as diverse as SPOT-5, VNREDSat-1, Google Earth from 2013 to 2019 to demonstrate the ability of the MCVA method to combine many other types of remote sensing images together. The results of fluctuation analysis were validated by 200 random points in the study area, and the accuracy of result is more than 90%. The results of land use change statistics were also compared with the annual data of Tan Rai Bauxite Factory. From this study, it can be concluded that the MCVA analysis method can quickly detect land use change areas and can combine many different image sources with a high accuracy. In addition, it also provides statistics of mining areas and restored areas, thereby assisting managers in monitoring the operation of the mine.展开更多
A new method for determining the freshness of harvested carp using nuclear imaging technology is presented.This research attempted to determine the freshness of carp by measuring the radioactive area increase (RAI) va...A new method for determining the freshness of harvested carp using nuclear imaging technology is presented.This research attempted to determine the freshness of carp by measuring the radioactive area increase (RAI) value of fish.The carp samples were maintained under refrigerated condition for 12d, and RAI and total volatile base nitrogen (T-VBN)values were determined during the storage. The results showed that the RAI value increased with the T-VBN content duringthe storage. Also, there is a significant correlation between T-VBN content and RAI value of the carp kept in refrigeratedcondition. The results of this study suggest that the RAI value could be utilized to evaluate rapidly the freshness of carp.展开更多
From all-trans retinoic acid (ATRA)-treated human lung adenocarcinoma GLC-82 cells and control, subtractive cDNA library has been constructed using subtractive hybridization technique in our laboratory. The screening ...From all-trans retinoic acid (ATRA)-treated human lung adenocarcinoma GLC-82 cells and control, subtractive cDNA library has been constructed using subtractive hybridization technique in our laboratory. The screening of the cDNA subtractive library resulted in identification of a clone containing cDNA fragment of one ATRA-induced gene (RAI) in GLC-82 cells. The positive clone with full-length cDNA of RAI was identified by screening fetal brain cDNA library using colony hybridization technique, and then sequenced. RT-PCR results showed that RAI was expressed in many different human fetal tissues. These results suggest that RAI may be involved in cell differentiation and play an important role in vital activities of cells.展开更多
Although Brassica juncea (Indian mustard) is reported to be a good accumulator of metals, little is known of the selected varieties of B. juncea (cvs. Rai and BARI-11). This paper investigates the phytoaccumulation of...Although Brassica juncea (Indian mustard) is reported to be a good accumulator of metals, little is known of the selected varieties of B. juncea (cvs. Rai and BARI-11). This paper investigates the phytoaccumulation of arsenic, cadmium and lead by B. juncea (cvs. Rai and BARI-11) parents and F1 hybrids. The experiment was conducted in the hydroponic media in the greenhouse of University of Southampton under a Randomised Block Design. Sodium arsenite, cadmium sulphate and lead nitrate with 0 ppm, 0.5 ppm and 1 ppm were used. The cadmium treated plants were analysed by Varian Atomic absorption spectrophotometer-200. The samples of arsenic and lead were analysed by Inductively Coupled Plasma Atomic Emission Spectrophotometer. The results suggest that arsenic was detected only in the root systems while cadmium and lead were detected both in the root and shoot systems. Significant differences in the uptake were observed for different concentrations. Accumulation of arsenic was detected only in the root systems of B. juncea (cvs. Rai and BARI-11) at lower concentrations. Hence, this can be used as an agriculturally viable and efficient phytoaccumulator in the arsenic affected areas where contamination level is low and the contamination occurs at the rooting level.展开更多
Understanding the environmental factors that influence tree species composition is essential for successful management of biodiversity and sustainable use of community forest resources.This study aims to assess tree s...Understanding the environmental factors that influence tree species composition is essential for successful management of biodiversity and sustainable use of community forest resources.This study aims to assess tree species composition and distribution in the deciduous Ban Mae Chiang Rai Lum Community Forest in Northern Thailand and to analyze the influence of environmental factors on tree biodiversity in the forest.We conducted a stratified systematic sampling of the forest’s total area of 3925 ha,and twenty-five 0.16 ha survey plots were established in three different stands of the deciduous forests to estimate and characterize the difference in biological diversity among the stands.Canonical correspondence analysis(CCA)was used to investigate the environment factors affecting such differences in biodiversity of the stands.The results showed a high diversity of trees in the forest as 197 species,144 genera,and 62 plant families were recorded.The CCA ordination identified the environmental factors—the most important of which were elevation,distance to streams,soil moisture,organic matter,and distance to communities—that signifi-cantly influenced the diversity and distribution of tree species(p<0.05)in the community forest.Our findings indicate that the implementation of drought reduction measures such as building check dams,fire protection,and monitoring community forest-product usage would be recommended to further biodiversity conservation and the sustainable use of community forest resources.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.10134020 and 40374049).
文摘Numerical study on scanning radiation acoustic field in formations generated by linear phased array transmitters in a fluid-filled borehole is carried out using a real axis integration (RAI) method. The main lobe width of the acoustic beams and the incident angle on the borehole wall can be controlled by means of adjusting parameters, such as the element number and the delay time between the neighboring array elements of linear phased array transmitter. The steered angle of longitudinal waves generated in the formation satisfies the Snell’s law for plane waves when the incident angle on the borehole wall is less than the first critical angle. When the lobe width of the acoustic beams is narrow and the steered angle is less than the first critical angle, the acoustic field in the formation can be approximately calculated given that the linear phased array is put in the formation without borehole. The technique of scanning radiation acoustic field can be applied to enhancing investigation resolution and signal-to-noise ratio in crosswell seismic survey and borehole acoustic reflection imaging.
基金This work is supported by the National Key R&D Program of China(No.2017YFB1200800)the National Natural Science Foundation of China(No.11725210,11572281,51827810,51637009)+1 种基金the Fundamental Research Funds for the Central Universities(2018XZZX001-05)the National Student’s Platform for Innovation and Entrepreneurship Training Program(201910335115).
文摘Electromagnetic railgun attracts more and more attention due to its advantage in speed,cost,and obscurity.It is found that the rail should withstand huge mechanical and thermal shocks during the launching operation.The forms of rail failure are accompanied by gouge,grooving,transition,and arc ablation,etc.The service life of the rail has become a bottleneck restricting the development of electromagnetic railgun technology.A series of researches are carried out to solve rail failure,including analysing the failure mechanism and using various advanced rail materials.This paper provides a comprehensive review of rail materials,including material composition,preparation,microstructure,and properties.We begin from a short background of the requirement of the rail material.Then a detailed investigation of rail materials is described,and the performances of those materials are introduced.Finally,further development prospect of rail material is discussed.
文摘Climate is subject to fluctuations in the majority of the world, mainly caused by rainfall as well as temperature variations. Climate fluctuations in Kenya have resulted in the spread of desert-like conditions in the ASALs region, such as Marigat in Baringo County. As a county, Baringo experiences great variations in climate annually, as well as uncertainty in expected rains, thereby negatively impacting the production of crops such as sorghum. This study applied the rainfall anomaly index (RAI), standardised precipitation evapotranspiration index (SPEI), standard precipitation index (SPI), and Mann-Kendall (MK) statistical test for trends on historical climatic data in analysing both temperature and precipitation data over the period 1990 to 2022 to determine their trend, patterns and how they affect the production of sorghum crops. The machine learning method (R studio) with inputs was used to calculate the SPI, SPEI, RAI and MK trend test. The rainfall varied from below average to above average during the study period with no clear pattern in the RAI, SPEI and SPI values. The years 2020 and 2000 stood out as they had higher and lower rainfall than usual, respectively. The Marigat area generally experienced more rainfall during the high/long rainfall season (AMJJ). The MK trend test on average monthly rainfall, SOND, AMJJ, and annual precipitation confirmed a positive trend in precipitation. However, the short rainy season (SOND) was found to be the most variable period for rainfall, and there was a slight increase in daily average temperatures during this season.
基金supported by the Project on InterGovernmental International Scientific and Technological Innovation Cooperation in National Key Projects of Research and Development Plan (No. 2019YFE0106400)the National Natural Science Foundation of China (No. 81771875)。
文摘Objective: Patients with radioactive iodine-refractory differentiated thyroid cancer(RAIR-DTC) are often diagnosed with delay and constrained to limited treatment options. The correlation between RAI refractoriness and the underlying genetic characteristics has not been extensively studied.Methods: Adult patients with distant metastatic DTC were enrolled and assigned to undergo next-generation sequencing of a customized 26-gene panel(Thyro Lead). Patients were classified into RAIR-DTC or non-RAIR groups to determine the differences in clinicopathological and molecular characteristics. Molecular risk stratification(MRS) was constructed based on the association between molecular alterations identified and RAI refractoriness, and the results were classified as high, intermediate or low MRS.Results: A total of 220 patients with distant metastases were included, 63.2% of whom were identified as RAIRDTC. Genetic alterations were identified in 90% of all the patients, with BRAF(59.7% vs. 17.3%), TERT promoter(43.9% vs. 7.4%), and TP53 mutations(11.5% vs. 3.7%) being more prevalent in the RAIR-DTC group than in the non-RAIR group, except for RET fusions(15.8% vs. 39.5%), which had the opposite pattern. BRAF and TERT promoter are independent predictors of RAIR-DTC, accounting for 67.6% of patients with RAIR-DTC. MRS was strongly associated with RAI refractoriness(P<0.001), with an odds ratio(OR) of high to low MRS of 7.52 [95%confidence interval(95% CI), 3.96-14.28;P<0.001] and an OR of intermediate to low MRS of 3.20(95% CI,1.01-10.14;P=0.041).Conclusions: Molecular alterations were associated with RAI refractoriness, with BRAF and TERT promoter mutations being the predominant contributors, followed by TP53 and DICER1 mutations. MRS might serve as a valuable tool for both prognosticating clinical outcomes and directing precision-based therapeutic interventions.
文摘The Tan Rai Bauxite Project, which exploits a large bauxite mine in Lam Dong province, Vietnam has been in operation since 2012. In addition to the economic efficiency of the project, bauxite mining and processing uses a large area arable land and affect the regional environment. Remote sensing technology is increasingly widely used in many purposes in monitoring the changes of environment and resources, including land use change with high accuracy, giving managers more information to monitor the exploitation and use process of land resource. This study used a Change Vector Analysis (CVA) method of analysis on various remote sensing data sources to monitor the process of land exploitation and restoration of the Tan Rai Bauxite project. High-resolution remote sensing images were used as diverse as SPOT-5, VNREDSat-1, Google Earth from 2013 to 2019 to demonstrate the ability of the MCVA method to combine many other types of remote sensing images together. The results of fluctuation analysis were validated by 200 random points in the study area, and the accuracy of result is more than 90%. The results of land use change statistics were also compared with the annual data of Tan Rai Bauxite Factory. From this study, it can be concluded that the MCVA analysis method can quickly detect land use change areas and can combine many different image sources with a high accuracy. In addition, it also provides statistics of mining areas and restored areas, thereby assisting managers in monitoring the operation of the mine.
文摘A new method for determining the freshness of harvested carp using nuclear imaging technology is presented.This research attempted to determine the freshness of carp by measuring the radioactive area increase (RAI) value of fish.The carp samples were maintained under refrigerated condition for 12d, and RAI and total volatile base nitrogen (T-VBN)values were determined during the storage. The results showed that the RAI value increased with the T-VBN content duringthe storage. Also, there is a significant correlation between T-VBN content and RAI value of the carp kept in refrigeratedcondition. The results of this study suggest that the RAI value could be utilized to evaluate rapidly the freshness of carp.
文摘From all-trans retinoic acid (ATRA)-treated human lung adenocarcinoma GLC-82 cells and control, subtractive cDNA library has been constructed using subtractive hybridization technique in our laboratory. The screening of the cDNA subtractive library resulted in identification of a clone containing cDNA fragment of one ATRA-induced gene (RAI) in GLC-82 cells. The positive clone with full-length cDNA of RAI was identified by screening fetal brain cDNA library using colony hybridization technique, and then sequenced. RT-PCR results showed that RAI was expressed in many different human fetal tissues. These results suggest that RAI may be involved in cell differentiation and play an important role in vital activities of cells.
文摘Although Brassica juncea (Indian mustard) is reported to be a good accumulator of metals, little is known of the selected varieties of B. juncea (cvs. Rai and BARI-11). This paper investigates the phytoaccumulation of arsenic, cadmium and lead by B. juncea (cvs. Rai and BARI-11) parents and F1 hybrids. The experiment was conducted in the hydroponic media in the greenhouse of University of Southampton under a Randomised Block Design. Sodium arsenite, cadmium sulphate and lead nitrate with 0 ppm, 0.5 ppm and 1 ppm were used. The cadmium treated plants were analysed by Varian Atomic absorption spectrophotometer-200. The samples of arsenic and lead were analysed by Inductively Coupled Plasma Atomic Emission Spectrophotometer. The results suggest that arsenic was detected only in the root systems while cadmium and lead were detected both in the root and shoot systems. Significant differences in the uptake were observed for different concentrations. Accumulation of arsenic was detected only in the root systems of B. juncea (cvs. Rai and BARI-11) at lower concentrations. Hence, this can be used as an agriculturally viable and efficient phytoaccumulator in the arsenic affected areas where contamination level is low and the contamination occurs at the rooting level.
基金supported by the Southeast Asian Regional Center for Graduate Study and Research in Agriculture(SEARCA)-ASEAN Working Group on Social Forestry Strategic Response Fund(ASRF)under the ASEANSwiss Partnership on Social Forestry and Climate Change and by the R&D Program for Forest Science Technology(Project No.2018113C10-2020-BB01)provided by Korea Forest Service(Korea Forestry Promotion Institute).
文摘Understanding the environmental factors that influence tree species composition is essential for successful management of biodiversity and sustainable use of community forest resources.This study aims to assess tree species composition and distribution in the deciduous Ban Mae Chiang Rai Lum Community Forest in Northern Thailand and to analyze the influence of environmental factors on tree biodiversity in the forest.We conducted a stratified systematic sampling of the forest’s total area of 3925 ha,and twenty-five 0.16 ha survey plots were established in three different stands of the deciduous forests to estimate and characterize the difference in biological diversity among the stands.Canonical correspondence analysis(CCA)was used to investigate the environment factors affecting such differences in biodiversity of the stands.The results showed a high diversity of trees in the forest as 197 species,144 genera,and 62 plant families were recorded.The CCA ordination identified the environmental factors—the most important of which were elevation,distance to streams,soil moisture,organic matter,and distance to communities—that signifi-cantly influenced the diversity and distribution of tree species(p<0.05)in the community forest.Our findings indicate that the implementation of drought reduction measures such as building check dams,fire protection,and monitoring community forest-product usage would be recommended to further biodiversity conservation and the sustainable use of community forest resources.
