基于web of science和知网数据源,利用Derwent Data Analyzer,VOSvievwer和Incites对1960—2022年盐湖相关文献进行计量分析,以深入了解国际和国内盐湖研究进展和发展趋势。分析得出近60多年盐湖研究发文量整体上呈先稳定后增加的趋势;...基于web of science和知网数据源,利用Derwent Data Analyzer,VOSvievwer和Incites对1960—2022年盐湖相关文献进行计量分析,以深入了解国际和国内盐湖研究进展和发展趋势。分析得出近60多年盐湖研究发文量整体上呈先稳定后增加的趋势;盐湖相关研究国际发文数量最高的期刊是International Journal of Systematic and Evolutionary Microbiology,国内发文量最高的期刊是《盐湖研究》。美国和中国是盐湖研究的核心力量,两者的总发文量、总引频次和高被引论文数均居前2位。盐湖研究领域发文量最高的机构是中国科学院,其隶属单位青海盐湖研究所发文量占比最高。国际文献作者前15位中8位来自中国。国际和国内研究热点演进分析得出今后盐湖资源的分离和提取将得到持续关注,高被引文章分析说明近年来盐湖研究关注最多的为盐湖资源的分离提取,尤其是锂资源。整体而言,有关盐湖研究还在不断拓展和延伸,未来我国应在文章质量、研究方向布局和影响力上继续提升,发挥国内盐湖研究的对外影响力。展开更多
The depositional environment of the sands of the cover formation is discussed. This study aims to determine the paleoenvironments of deposition of the sands of the cover formation in the Batéké Plateaus by s...The depositional environment of the sands of the cover formation is discussed. This study aims to determine the paleoenvironments of deposition of the sands of the cover formation in the Batéké Plateaus by studying sedimentary dynamics based on the description of lithological facies in the field and granulometric analyses in the laboratory. In the field, six (6) lithostratigraphic logs were surveyed and 42 sand samples were taken for laboratory analysis. In the laboratory, the samples underwent granulometric, sieving and sedimentometry analyses, after washing with running water using a 63 µm sieve. These analyses made it possible to determine the granulometric classes of the samples. The sieving results allowed to determine the granulometric parameters (mean, standard deviation, mode, median, skewness, flattening or kurtosis) using the method of moments with the software “Gradistat V.8”, granulometric parameters with which the granulometric facies, the mode of transport and the deposition environment were determined using the diagrams. Morphoscopy made it possible to determine the form and aspect of the surface of the quartz grains constituting these sands. Granulometric analyses show that these silty-clay or clayey-silty sands are fine sands and rarely medium sands, moderately to well sorted and rarely well sorted. The dominant granulometric facies is hyperbolic (sigmoid), with parabolic facies being rare. The primary mode of transport of these sands is saltation, which dominates rolling. The dispersion of points in the diagrams shows that these sands originate from two depositional environments: aeolian and fluvial. Morphoscopic analysis reveals the presence of clean rounded matt grains (RM), dirty rounded matt grains (RS), shiny blunt grains (EL) and shiny rounded grains (RL). The rounded matt grains exhibit several impact marks. The presence of dirty rounded grains with a ferruginous cement on their surface indicates that these sands have been reworked. These sands have undergone two types of transport, first by wind (aeolian environment) and then by water (fluvial environment).展开更多
An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of ...An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of fast ions in the HL-2A/3 tokamak.The E//B NPA contains three main units,i.e.the stripping unit,the analyzing unit and the detection unit.A gas stripping chamber was adopted as the stripping unit.The results of the simulations and beam tests for the stripping chamber are presented.Parallel electric and magnetic fields provided by a NdFeB permanent magnet and two parallel electric plates were designed and constructed for the analyzing unit.The calibration of the magnetic and electric fields was performed using a 50 kV electron cyclotron resonance ion source(ECRIS)platform.The detection unit consists of 32lutetium-yttrium oxyorthosilicate(LYSO)detector modules arranged in two rows.The response functions ofα,hydrogen ions(H^(+),H_(2)^(+)and H_(3)^(+))andγfor a detector module were measured with^(241)Am,^(137)Cs and^(152)Eu sources together with the 50 kV ECRIS platform.The overall results indicate that the designed E//B NPA device is capable of measuring the intensity of neutral hydrogen and deuteron atoms with energy higher than 20 keV.展开更多
本文采用夹点技术对某炼油厂常减压装置现有生产工况下的换热网络进行分析优化并提出改进方案。应用Aspen plus建立了常减压塔模型及相应的换热网络,计算各侧线流股流量和物性数据。利用Aspen Energy Analyzer计算得到该换热网络的夹点...本文采用夹点技术对某炼油厂常减压装置现有生产工况下的换热网络进行分析优化并提出改进方案。应用Aspen plus建立了常减压塔模型及相应的换热网络,计算各侧线流股流量和物性数据。利用Aspen Energy Analyzer计算得到该换热网络的夹点温度。通过夹点温度来分析诊断换热网络中跨越夹点物流,确定换热网络中瓶颈的位置。通过调整不合理配置的冷热流股换热器来优化换热网络,使脱盐原油进入常压塔的换热终温从288.0℃提高到310.4℃,优化后的冷、热公用工程用量各减少2808.0kW,显著降低了装置的操作费用。展开更多
AIM:To invastigate intra-and interobserver reliability of interferometry,tear meniscus height(TMH)measurement and meibography(MBG)of an ocular surface analyzer,LacryDiag(Quantel Medical,France).METHODS:Five consecutiv...AIM:To invastigate intra-and interobserver reliability of interferometry,tear meniscus height(TMH)measurement and meibography(MBG)of an ocular surface analyzer,LacryDiag(Quantel Medical,France).METHODS:Five consecutive measurements and subsequent analysis of interferometry,TMH,and MBG were recorded by two examiners using the LacryDiag.To assess intra-and interobserver reliability,we used Cohen’s kappa for categorical variables(interferometry),or intraclass correlation coefficient for continuous variables(TMH,MBG).RESULTS:Thirty eyes of 30 examinees were included.For both observers,there was excellent intraobserver reliability for MBG(0.955 and 0.970 for observer 1 and 2,respectively).Intraobserver reliability for observer 1 was substantial for interferometry(0.799),and excellent for TMH(0.863).Reliability for observer 2 was moderate for interferometry(0.535)and fair to good for TMH(0.431).Interobserver reliability was poor for interferometry(0.074)and fair to good for TMH(0.680)and MBG(0.414).CONCLUSION:LacryDiag ocular surface analyzer in our study proves to be a reliable noninvasive tool for the evaluation of TMH and MBG.As for interferometry,poor interobserver reliability,fair to good intraobserver reliability for observer 1,and moderate for observer 2,leave room for improvement.展开更多
The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission is a joint space science mission between the Chinese Academy of Sciences(CAS)and the European Space Agency(ESA),aiming to understand the interaction ...The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission is a joint space science mission between the Chinese Academy of Sciences(CAS)and the European Space Agency(ESA),aiming to understand the interaction of the solar wind with the Earth’s magnetosphere in a global manner.As of May 2024,the SMILE mission is in phase-D with an expected launch date of September 2025.This report summarizes developments in the mission during the past two years.展开更多
Fast neutron flux measurements with high count rates and high time resolution have important applications in equipment such as tokamaks.In this study,real-time neutron and gamma discrimination was implemented on a sel...Fast neutron flux measurements with high count rates and high time resolution have important applications in equipment such as tokamaks.In this study,real-time neutron and gamma discrimination was implemented on a self-developed 500-Msps,12-bit digitizer,and the neutron and gamma spectra were calculated directly on an FPGA.A fast neutron flux measurement system with BC-501A and EJ-309 liquid scintillator detectors was developed and a fast neutron measurement experiment was successfully performed on the HL-2 M tokamak at the Southwestern Institute of Physics,China.The experimental results demonstrated that the system obtained the neutron and gamma spectra with a time accuracy of 1 ms.At count rates of up to 1 Mcps,the figure of merit was greater than 1.05 for energies between 50 keV and 2.8 MeV.展开更多
Accurate measurement of the average plasma parameters in the edge region,including the temperature and density of electrons and ions,is critical for understanding the characteristics of the scrape-off layer(SOL) and d...Accurate measurement of the average plasma parameters in the edge region,including the temperature and density of electrons and ions,is critical for understanding the characteristics of the scrape-off layer(SOL) and divertor plasma transport in magnetically confined fusion research.On the J-TEXT tokamak,a multi-channel retarding field analyzer(RFA) probe has been developed to study average plasma parameters in the edge region under various poloidal divertor and island divertor configurations.The edge radial profile of the ion-to-electron temperature ratio,τ_(i/e),has been determined,which gradually decreases as the SOL ion self-collisionality,v_(SOL)*,increases.This is broadly consistent with what has been observed previously from various tokamak experiments.However,the comparison of experimental results under different configurations shows that in the poloidal divertor configuration,even under the same v_(SOL)*,τ_(i/e) in the SOL region becomes smaller as the distance from the X-point to the target plate increases.In the island divertor configuration,τ_(i/e) near the O-point is higher than that near the X-point at the same v_(SOL)*,and both are higher than those in the limiter configuration.These results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.展开更多
This research was conducted in the Qassim region, Kingdom of Saudi Arabia. The goal of this research is to determine the percentage of silicon in the Rub al-Khali desert. Samples were collected from four cities locate...This research was conducted in the Qassim region, Kingdom of Saudi Arabia. The goal of this research is to determine the percentage of silicon in the Rub al-Khali desert. Samples were collected from four cities located in the Al-Qassim Region of Saudi Arabia (Uyun Al-Jawa, Al-Fuwailiq, Al-Sulaibiya, and Al-Qawara), from three distinct depths (the earth’s surface, 50 cm, and 100 cm). The percentages of silicon in these places vary between the highest value for silicon dioxide, which is 74.47 m/m%, and 34.8 m/m% for silicon in Al-Qawara city at a depth of 100 cm. We used an x-ray fluorescence (XRF) instrument to evaluate the samples. There are high percentage of both silica and silicon in the Nafud desert. Studies have shown that these ratios can help investors benefit from an element of Silicon and silicon dioxide, so the sands of the Nafud desert is sufficient for extracting Silicon and silica in huge quantities. This may transform the Kingdom into a leading country in the global computer technology industry that depends on silicon extracted from the desert sands, the most important of which are microcomputer data processing devices.展开更多
To verify the effectiveness of digital optical 3D image analyzer EvaSKIN in the objective and quantitative evaluation of wrinkles.A total of 115 subjects were recruited,the facial images of the subjects were collected...To verify the effectiveness of digital optical 3D image analyzer EvaSKIN in the objective and quantitative evaluation of wrinkles.A total of 115 subjects were recruited,the facial images of the subjects were collected by digital optical 3D image analyzer and manual camera,the changes of crow’s feet with age were analyzed.Pictures obtained by manual photography can be directly used for observation and preliminary grading of wrinkles.However,the requirements for evaluators are high,and the results are prone to errors,which will affect the accuracy of the evaluation.Therefore,skilled raters are needed.Compared with the manual photography method,the digital optical 3D image analyzer EvaSKIN can realize three-dimensional extraction of wrinkles,and obtain the change trend of crow’s feet with age.20~30 years old,wrinkles begin to appear slowly;wrinkles will increase rapidly at the age of 30~50;The length of 50~60 year old wrinkles is basically fixed,the wrinkles develop longitudewise,gradually widen and deepen,and the area,depth and volume increase is obvious,and the skin aging condition is intensified.the digital optical 3D image analyzer EvaSKIN realizes the 3D extraction of wrinkles,quantifies the circumference,area,average depth,maximum depth and volume of wrinkles,realizes the objective and quantitative evaluation of wrinkle state,is more accurate in the measurement of wrinkles,and provides a new instrument and method for the evaluation of wrinkles.it is a perfect and supplement to the traditional evaluation methods,and to a certain extent,it helps the research and development and evaluation institutions of cosmetics to obtain more abundant and three-dimensional data support.展开更多
Objective:To analyze the technical indexes of students’online learning behavior analysis based on Kirkman’s evaluation model,sort out the basic indexes of online learning behavior,and extract scientific and efficien...Objective:To analyze the technical indexes of students’online learning behavior analysis based on Kirkman’s evaluation model,sort out the basic indexes of online learning behavior,and extract scientific and efficient evaluation indexes of online learning effect through statistical analysis.Methods:The online learning behavior data of Physiology of nursing students from 2021-2023 and the first semester of 22 nursing classes(3 and 4)were collected and analyzed.The preset learning behavior indexes were analyzed by multi-dimensional analysis and a correlation analysis was conducted between the indexes and the final examination scores to screen for the dominant important indexes for online learning effect evaluation.Results:The study found that the demand for online learning of nursing students from 2021-2023 increased and the effect was statistically significant.Compared with the stage assessment results,the online learning effect was statistically significant.Conclusion:The main indicators for evaluating and classifying online learning behaviors were summarized.These two indicators can help teachers predict which part of students need learning intervention,optimize the teaching process,and help students improve their learning behavior and academic performance.展开更多
Objective:To investigate the hook effect in the detection of beta2-microglobulin(β2-MG)with different reagents as well as on two fully automated biochemical analyzers and their solutions.Methods:Using immunoturbidime...Objective:To investigate the hook effect in the detection of beta2-microglobulin(β2-MG)with different reagents as well as on two fully automated biochemical analyzers and their solutions.Methods:Using immunoturbidimetric assay forβ2-MG as the research object,β2-MG levels were detected by different concentration gradients ofβ2-microglobulin samples in Liedemann,Mack,and Myriad reagents of three manufacturers on two automatic biochemical analyzers,and the difference of the hook effect was comparatively analyzed.Results:Leadman reagent showed the hook effect on the Beckman AU5800 automated biochemistry analyzer,while both Maccura and Mindray reagents did not show the hook effect.After the experiments,we found the limit value of the pre-zone check of Leadman reagent,and changed the parameters of the instrument,when the limit value of the pre-zone check was reached,the instrument automatically diluted the specimen five times and then detected it again.After changing the parameters of the instrument,the correlation between the three methods of detecting samples of different concentrations was r>0.99.Conclusion:Before selecting the application of immunoturbidimetric reagents,we have to carry out the risk assessment of the hook effect and selectively set the parameters of the pre-zone check based on the highest concentration that may occur in the clinic;for the items that may have the hook effect,we have to selectively set the parameters of the pre-zone check when the ratio of average reaction rate and the immediate reaction rate is at the limit value,and the phenomenon of antigen excess may occur,the instrument will carry out automatic dilution before detection,so as to avoid the issuance of erroneous results of high-value samples due to the hook effect.展开更多
The pitch angle distributions of ions and electrons can be affected by various processes;thus,they can serve as an important indicator of the physical mechanisms driving the dynamics of space plasmas.From observations...The pitch angle distributions of ions and electrons can be affected by various processes;thus,they can serve as an important indicator of the physical mechanisms driving the dynamics of space plasmas.From observations from the Mars Ion and Neutral Particle Analyzer onboard the Tianwen-1 orbiter,we calculated the pitch angle distributions of protons in the Martian induced magnetosphere by using information from the magnetohydrodynamically simulated magnetic field,and we statistically analyzed the spatial occurrence pattern of different types of pitch angle distributions.Even though no symmetrical features were seen in the dataset,we found the dominance of the field-aligned distribution type over the energy range from 188 to 6232 eV.Maps of the occurrence rate showed the preferential presence of a trapped-like distribution at the lower altitudes of the surveyed nightside region.Although our results are more or less restricted by the adopted magnetic field,they indicate the complexity of the near-Mars proton pitch angle distributions and infer the possibility of wave–particle interactions in the Martian induced magnetosphere.展开更多
文摘基于web of science和知网数据源,利用Derwent Data Analyzer,VOSvievwer和Incites对1960—2022年盐湖相关文献进行计量分析,以深入了解国际和国内盐湖研究进展和发展趋势。分析得出近60多年盐湖研究发文量整体上呈先稳定后增加的趋势;盐湖相关研究国际发文数量最高的期刊是International Journal of Systematic and Evolutionary Microbiology,国内发文量最高的期刊是《盐湖研究》。美国和中国是盐湖研究的核心力量,两者的总发文量、总引频次和高被引论文数均居前2位。盐湖研究领域发文量最高的机构是中国科学院,其隶属单位青海盐湖研究所发文量占比最高。国际文献作者前15位中8位来自中国。国际和国内研究热点演进分析得出今后盐湖资源的分离和提取将得到持续关注,高被引文章分析说明近年来盐湖研究关注最多的为盐湖资源的分离提取,尤其是锂资源。整体而言,有关盐湖研究还在不断拓展和延伸,未来我国应在文章质量、研究方向布局和影响力上继续提升,发挥国内盐湖研究的对外影响力。
文摘The depositional environment of the sands of the cover formation is discussed. This study aims to determine the paleoenvironments of deposition of the sands of the cover formation in the Batéké Plateaus by studying sedimentary dynamics based on the description of lithological facies in the field and granulometric analyses in the laboratory. In the field, six (6) lithostratigraphic logs were surveyed and 42 sand samples were taken for laboratory analysis. In the laboratory, the samples underwent granulometric, sieving and sedimentometry analyses, after washing with running water using a 63 µm sieve. These analyses made it possible to determine the granulometric classes of the samples. The sieving results allowed to determine the granulometric parameters (mean, standard deviation, mode, median, skewness, flattening or kurtosis) using the method of moments with the software “Gradistat V.8”, granulometric parameters with which the granulometric facies, the mode of transport and the deposition environment were determined using the diagrams. Morphoscopy made it possible to determine the form and aspect of the surface of the quartz grains constituting these sands. Granulometric analyses show that these silty-clay or clayey-silty sands are fine sands and rarely medium sands, moderately to well sorted and rarely well sorted. The dominant granulometric facies is hyperbolic (sigmoid), with parabolic facies being rare. The primary mode of transport of these sands is saltation, which dominates rolling. The dispersion of points in the diagrams shows that these sands originate from two depositional environments: aeolian and fluvial. Morphoscopic analysis reveals the presence of clean rounded matt grains (RM), dirty rounded matt grains (RS), shiny blunt grains (EL) and shiny rounded grains (RL). The rounded matt grains exhibit several impact marks. The presence of dirty rounded grains with a ferruginous cement on their surface indicates that these sands have been reworked. These sands have undergone two types of transport, first by wind (aeolian environment) and then by water (fluvial environment).
基金supported by the National Magnetic Confinement Fusion Energy R&D Program of China(No.2018YFE0310200)National Natural Science Foundation of China(Nos.11705242,11805138 and 12175156)the Fundamental Research Funds for the Central Universities in China(Nos.YJ201820 and YJ201954)。
文摘An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of fast ions in the HL-2A/3 tokamak.The E//B NPA contains three main units,i.e.the stripping unit,the analyzing unit and the detection unit.A gas stripping chamber was adopted as the stripping unit.The results of the simulations and beam tests for the stripping chamber are presented.Parallel electric and magnetic fields provided by a NdFeB permanent magnet and two parallel electric plates were designed and constructed for the analyzing unit.The calibration of the magnetic and electric fields was performed using a 50 kV electron cyclotron resonance ion source(ECRIS)platform.The detection unit consists of 32lutetium-yttrium oxyorthosilicate(LYSO)detector modules arranged in two rows.The response functions ofα,hydrogen ions(H^(+),H_(2)^(+)and H_(3)^(+))andγfor a detector module were measured with^(241)Am,^(137)Cs and^(152)Eu sources together with the 50 kV ECRIS platform.The overall results indicate that the designed E//B NPA device is capable of measuring the intensity of neutral hydrogen and deuteron atoms with energy higher than 20 keV.
文摘本文采用夹点技术对某炼油厂常减压装置现有生产工况下的换热网络进行分析优化并提出改进方案。应用Aspen plus建立了常减压塔模型及相应的换热网络,计算各侧线流股流量和物性数据。利用Aspen Energy Analyzer计算得到该换热网络的夹点温度。通过夹点温度来分析诊断换热网络中跨越夹点物流,确定换热网络中瓶颈的位置。通过调整不合理配置的冷热流股换热器来优化换热网络,使脱盐原油进入常压塔的换热终温从288.0℃提高到310.4℃,优化后的冷、热公用工程用量各减少2808.0kW,显著降低了装置的操作费用。
文摘AIM:To invastigate intra-and interobserver reliability of interferometry,tear meniscus height(TMH)measurement and meibography(MBG)of an ocular surface analyzer,LacryDiag(Quantel Medical,France).METHODS:Five consecutive measurements and subsequent analysis of interferometry,TMH,and MBG were recorded by two examiners using the LacryDiag.To assess intra-and interobserver reliability,we used Cohen’s kappa for categorical variables(interferometry),or intraclass correlation coefficient for continuous variables(TMH,MBG).RESULTS:Thirty eyes of 30 examinees were included.For both observers,there was excellent intraobserver reliability for MBG(0.955 and 0.970 for observer 1 and 2,respectively).Intraobserver reliability for observer 1 was substantial for interferometry(0.799),and excellent for TMH(0.863).Reliability for observer 2 was moderate for interferometry(0.535)and fair to good for TMH(0.431).Interobserver reliability was poor for interferometry(0.074)and fair to good for TMH(0.680)and MBG(0.414).CONCLUSION:LacryDiag ocular surface analyzer in our study proves to be a reliable noninvasive tool for the evaluation of TMH and MBG.As for interferometry,poor interobserver reliability,fair to good intraobserver reliability for observer 1,and moderate for observer 2,leave room for improvement.
基金Founded by the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences(XDA15350000)。
文摘The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission is a joint space science mission between the Chinese Academy of Sciences(CAS)and the European Space Agency(ESA),aiming to understand the interaction of the solar wind with the Earth’s magnetosphere in a global manner.As of May 2024,the SMILE mission is in phase-D with an expected launch date of September 2025.This report summarizes developments in the mission during the past two years.
基金supported by the National Magnetic Confinement Fusion Program of China(No.2019YFE03020002)the National Natural Science Foundation of China(Nos.12205085 and12125502)。
文摘Fast neutron flux measurements with high count rates and high time resolution have important applications in equipment such as tokamaks.In this study,real-time neutron and gamma discrimination was implemented on a self-developed 500-Msps,12-bit digitizer,and the neutron and gamma spectra were calculated directly on an FPGA.A fast neutron flux measurement system with BC-501A and EJ-309 liquid scintillator detectors was developed and a fast neutron measurement experiment was successfully performed on the HL-2 M tokamak at the Southwestern Institute of Physics,China.The experimental results demonstrated that the system obtained the neutron and gamma spectra with a time accuracy of 1 ms.At count rates of up to 1 Mcps,the figure of merit was greater than 1.05 for energies between 50 keV and 2.8 MeV.
基金supported by the National Magnetic Confinement Fusion Energy R&D Program of China (No.2018YFE0309100)National Natural Science Foundation of China (No.51821005)。
文摘Accurate measurement of the average plasma parameters in the edge region,including the temperature and density of electrons and ions,is critical for understanding the characteristics of the scrape-off layer(SOL) and divertor plasma transport in magnetically confined fusion research.On the J-TEXT tokamak,a multi-channel retarding field analyzer(RFA) probe has been developed to study average plasma parameters in the edge region under various poloidal divertor and island divertor configurations.The edge radial profile of the ion-to-electron temperature ratio,τ_(i/e),has been determined,which gradually decreases as the SOL ion self-collisionality,v_(SOL)*,increases.This is broadly consistent with what has been observed previously from various tokamak experiments.However,the comparison of experimental results under different configurations shows that in the poloidal divertor configuration,even under the same v_(SOL)*,τ_(i/e) in the SOL region becomes smaller as the distance from the X-point to the target plate increases.In the island divertor configuration,τ_(i/e) near the O-point is higher than that near the X-point at the same v_(SOL)*,and both are higher than those in the limiter configuration.These results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.
文摘This research was conducted in the Qassim region, Kingdom of Saudi Arabia. The goal of this research is to determine the percentage of silicon in the Rub al-Khali desert. Samples were collected from four cities located in the Al-Qassim Region of Saudi Arabia (Uyun Al-Jawa, Al-Fuwailiq, Al-Sulaibiya, and Al-Qawara), from three distinct depths (the earth’s surface, 50 cm, and 100 cm). The percentages of silicon in these places vary between the highest value for silicon dioxide, which is 74.47 m/m%, and 34.8 m/m% for silicon in Al-Qawara city at a depth of 100 cm. We used an x-ray fluorescence (XRF) instrument to evaluate the samples. There are high percentage of both silica and silicon in the Nafud desert. Studies have shown that these ratios can help investors benefit from an element of Silicon and silicon dioxide, so the sands of the Nafud desert is sufficient for extracting Silicon and silica in huge quantities. This may transform the Kingdom into a leading country in the global computer technology industry that depends on silicon extracted from the desert sands, the most important of which are microcomputer data processing devices.
文摘To verify the effectiveness of digital optical 3D image analyzer EvaSKIN in the objective and quantitative evaluation of wrinkles.A total of 115 subjects were recruited,the facial images of the subjects were collected by digital optical 3D image analyzer and manual camera,the changes of crow’s feet with age were analyzed.Pictures obtained by manual photography can be directly used for observation and preliminary grading of wrinkles.However,the requirements for evaluators are high,and the results are prone to errors,which will affect the accuracy of the evaluation.Therefore,skilled raters are needed.Compared with the manual photography method,the digital optical 3D image analyzer EvaSKIN can realize three-dimensional extraction of wrinkles,and obtain the change trend of crow’s feet with age.20~30 years old,wrinkles begin to appear slowly;wrinkles will increase rapidly at the age of 30~50;The length of 50~60 year old wrinkles is basically fixed,the wrinkles develop longitudewise,gradually widen and deepen,and the area,depth and volume increase is obvious,and the skin aging condition is intensified.the digital optical 3D image analyzer EvaSKIN realizes the 3D extraction of wrinkles,quantifies the circumference,area,average depth,maximum depth and volume of wrinkles,realizes the objective and quantitative evaluation of wrinkle state,is more accurate in the measurement of wrinkles,and provides a new instrument and method for the evaluation of wrinkles.it is a perfect and supplement to the traditional evaluation methods,and to a certain extent,it helps the research and development and evaluation institutions of cosmetics to obtain more abundant and three-dimensional data support.
基金Analysis and Research on Online Learning in Higher Vocational Colleges Based on Kirkpatrick Model-Taking the Course of Physiology as an Example(Project No.:D/2021/03/91)The excellent teaching team of Physiology of Suzhou Vocational College of Health Science and Technology in 2019(Project number:JXTD201912).
文摘Objective:To analyze the technical indexes of students’online learning behavior analysis based on Kirkman’s evaluation model,sort out the basic indexes of online learning behavior,and extract scientific and efficient evaluation indexes of online learning effect through statistical analysis.Methods:The online learning behavior data of Physiology of nursing students from 2021-2023 and the first semester of 22 nursing classes(3 and 4)were collected and analyzed.The preset learning behavior indexes were analyzed by multi-dimensional analysis and a correlation analysis was conducted between the indexes and the final examination scores to screen for the dominant important indexes for online learning effect evaluation.Results:The study found that the demand for online learning of nursing students from 2021-2023 increased and the effect was statistically significant.Compared with the stage assessment results,the online learning effect was statistically significant.Conclusion:The main indicators for evaluating and classifying online learning behaviors were summarized.These two indicators can help teachers predict which part of students need learning intervention,optimize the teaching process,and help students improve their learning behavior and academic performance.
基金Baoding Science and Technology Bureau(2141ZF313)。
文摘Objective:To investigate the hook effect in the detection of beta2-microglobulin(β2-MG)with different reagents as well as on two fully automated biochemical analyzers and their solutions.Methods:Using immunoturbidimetric assay forβ2-MG as the research object,β2-MG levels were detected by different concentration gradients ofβ2-microglobulin samples in Liedemann,Mack,and Myriad reagents of three manufacturers on two automatic biochemical analyzers,and the difference of the hook effect was comparatively analyzed.Results:Leadman reagent showed the hook effect on the Beckman AU5800 automated biochemistry analyzer,while both Maccura and Mindray reagents did not show the hook effect.After the experiments,we found the limit value of the pre-zone check of Leadman reagent,and changed the parameters of the instrument,when the limit value of the pre-zone check was reached,the instrument automatically diluted the specimen five times and then detected it again.After changing the parameters of the instrument,the correlation between the three methods of detecting samples of different concentrations was r>0.99.Conclusion:Before selecting the application of immunoturbidimetric reagents,we have to carry out the risk assessment of the hook effect and selectively set the parameters of the pre-zone check based on the highest concentration that may occur in the clinic;for the items that may have the hook effect,we have to selectively set the parameters of the pre-zone check when the ratio of average reaction rate and the immediate reaction rate is at the limit value,and the phenomenon of antigen excess may occur,the instrument will carry out automatic dilution before detection,so as to avoid the issuance of erroneous results of high-value samples due to the hook effect.
基金supported by the National Natural Science Foundation of China(Grant No.42241143)the pre-research projects on Civil Aerospace Technologies(No.D020104)funded by the China National Space Administration.
文摘The pitch angle distributions of ions and electrons can be affected by various processes;thus,they can serve as an important indicator of the physical mechanisms driving the dynamics of space plasmas.From observations from the Mars Ion and Neutral Particle Analyzer onboard the Tianwen-1 orbiter,we calculated the pitch angle distributions of protons in the Martian induced magnetosphere by using information from the magnetohydrodynamically simulated magnetic field,and we statistically analyzed the spatial occurrence pattern of different types of pitch angle distributions.Even though no symmetrical features were seen in the dataset,we found the dominance of the field-aligned distribution type over the energy range from 188 to 6232 eV.Maps of the occurrence rate showed the preferential presence of a trapped-like distribution at the lower altitudes of the surveyed nightside region.Although our results are more or less restricted by the adopted magnetic field,they indicate the complexity of the near-Mars proton pitch angle distributions and infer the possibility of wave–particle interactions in the Martian induced magnetosphere.