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Optimal Scheduling of an Independent Electro-Hydrogen System with Hybrid Energy Storage Using a Multi-Objective Standardization Fusion Method
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作者 Suliang Ma Zeqing Meng +1 位作者 Mingxuan Chen Yuan Jiang 《Energy Engineering》 EI 2025年第1期63-84,共22页
In the independent electro-hydrogen system(IEHS)with hybrid energy storage(HESS),achieving optimal scheduling is crucial.Still,it presents a challenge due to the significant deviations in values ofmultiple optimizatio... In the independent electro-hydrogen system(IEHS)with hybrid energy storage(HESS),achieving optimal scheduling is crucial.Still,it presents a challenge due to the significant deviations in values ofmultiple optimization objective functions caused by their physical dimensions.These deviations seriously affect the scheduling process.A novel standardization fusion method has been established to address this issue by analyzing the variation process of each objective function’s values.The optimal scheduling results of IEHS with HESS indicate that the economy and overall energy loss can be improved 2–3 times under different optimization methods.The proposed method better balances all optimization objective functions and reduces the impact of their dimensionality.When the cost of BESS decreases by approximately 30%,its participation deepens by about 1 time.Moreover,if the price of the electrolyzer is less than 15¥/kWh or if the cost of the fuel cell drops below 4¥/kWh,their participation will increase substantially.This study aims to provide a more reasonable approach to solving multi-objective optimization problems. 展开更多
关键词 Electro-hydrogen system multi-objective optimization standardization method hybrid energy storage system
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Effects of King’s Theory of Goal Attainment Combined with Teach-Back Method on Improving Patients’ Standardization Rate of Eye Drop Use
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作者 Qiuying Huang Guilian Jie Xiaohong Liu 《Journal of Clinical and Nursing Research》 2024年第12期22-27,共6页
Objective:To explore the effect of King’s Theory of Goal Attainment combined with teach-back method on improving the standardization rate of eye drop use in patients.Methods:A total of 200 patients who used more than... Objective:To explore the effect of King’s Theory of Goal Attainment combined with teach-back method on improving the standardization rate of eye drop use in patients.Methods:A total of 200 patients who used more than two types of eye drops in the Department of Ophthalmology of our hospital were selected as the research subjects,and were randomly divided into an observation group and a control group.The control group was given routine health education,while the observation group was given King’s Theory of Goal Attainment combined with teach-back method on the basis of the control group.The standardization rate of eye drop use,knowledge awareness rate,and nursing satisfaction were compared between the two groups before and after the intervention.Results:After the intervention,the standardization rate of eye drop use,the awareness rate of eye drop knowledge,and the nursing satisfaction of the observation group were significantly higher than those of the control group(P<0.05).Conclusion:King’s Theory of Goal Attainment combined with teach-back method can effectively improve the standardization rate of eye drop use in patients,increase their awareness of eye drop knowledge,and improve nursing satisfaction,which is worthy of clinical application. 展开更多
关键词 King’s Theory of Goal Attainment Teach-back method Eye drops standardization rate
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A Comprehensive Study on Application and Prospect of Hydrogel Detection Methods
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作者 Caixia Chen Pengyu Liu +3 位作者 Changhua Wang Yanyan Xie Wei Wang Xiaomin Kang 《Journal of Polymer Materials》 2025年第3期621-660,共40页
Due to their high water content,stimulus responsiveness,and biocompatibility,hydrogels,which are functional materials with a three-dimensional network structure,are widely applied in fields such as biomedicine,environ... Due to their high water content,stimulus responsiveness,and biocompatibility,hydrogels,which are functional materials with a three-dimensional network structure,are widely applied in fields such as biomedicine,environmental monitoring,and flexible electronics.This paper provides a systematic review of hydrogel charac-terization methods and their applications,focusing on primary evaluation techniques for physical properties(e.g.,mechanical strength,swelling behavior,and pore structure),chemical properties(e.g.,composition,crosslink density,and degradation behavior),biocompatibility,and functional properties(e.g.,drug release,environmental stimulus response,and conductivity).It analyzes the challenges currently faced by characterization methods,such as a lack of standardization,difficulties in dynamic monitoring,an insufficient micro-macro correlation,and poor adaptability to complex environments.It proposes solutions,such as a hierarchical standardization system,in situ imaging technology,cross-scale characterization,and biomimetic testing platforms.Looking ahead,hydrogel characterization techniques will evolve toward intelligent,real-time,multimodal coupling and standardized approaches.These techniques will provide superior technical support for precision medicine,environmental restoration,and flexible electronics.They will also offer systematic methodological guidance for the performance optimization and practical application of hydrogel materials. 展开更多
关键词 HYDROGEL characterization methods PROPERTIES standardIZATION APPLICATION
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Comment on“Development of an accelerometer age-and sex-specific approach based on population-standardized values for physical activity surveillance:A proof of concept”
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作者 Alex V.Rowlands Richard P.Troiano 《Journal of Sport and Health Science》 2025年第2期79-81,共3页
Device-based measurements are recommended to improve population-based physical activity(PA)surveillance.1,2However,implementation remains challenging due to lack of consensus on analytical methods,and the most widely ... Device-based measurements are recommended to improve population-based physical activity(PA)surveillance.1,2However,implementation remains challenging due to lack of consensus on analytical methods,and the most widely used“generic”(absolute intensity)cut-point approach has limited generalisability to population-level free-living data.Further,current methods generally fail to account for differences in people's physical capacity. 展开更多
关键词 ACCELEROMETER cut point approach physical activity age specific population standardized analytical methodsand analytical methods sex specific
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The Impact of the Internationalization of ESG Standards on the Trade Competitiveness of Multinational Enterprises:A Difference-in-Differences Test Based on Global Manufacturing Listed Companies
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作者 Yihan Wang 《Proceedings of Business and Economic Studies》 2025年第4期239-244,共6页
This paper takes global manufacturing listed companies from 2010 to 2022 as samples and uses the difference-in-differences(DID)method to empirically examine the impact of the internationalization of ESG standards on t... This paper takes global manufacturing listed companies from 2010 to 2022 as samples and uses the difference-in-differences(DID)method to empirically examine the impact of the internationalization of ESG standards on the trade competitiveness of multinational enterprises and their mechanisms.The research finds that the internationalization of ESG standards significantly enhances the trade competitiveness of multinational manufacturing enterprises,and this effect is dynamic and sustainable.The mechanism analysis indicates that the internationalization of ESG standards exerts its influence through three pathways:reducing enterprise financing costs,promoting technological innovation,and enhancing brand reputation.The heterogeneity analysis shows that this effect is more significant in enterprises from developed countries,high-pollution industries,and larger enterprises.This paper provides micro-level evidence for understanding the economic consequences of the internationalization of ESG standards and offers policy implications for multinational enterprises to cope with the global ESG rule changes and enhance their trade competitiveness. 展开更多
关键词 Internationalization of ESG standards Trade competitiveness Multinational enterprises Difference-in-differences method Manufacturing industry Online publication:September 10 20251.Introduction
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Using Different Standardized Methods for Species Identification:A Case Study Using Beaks from Three Ommastrephid Species 被引量:4
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作者 HU Guanyu FANG Zhou +3 位作者 LIU Bilin CHEN Xinjun STAPLES Kevin CHEN Yong 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第2期355-362,共8页
The cephalopod beak is a vital hard structure with a stable configuration and has been widely used for the identification of cephalopod species. This study was conducted to determine the best standardization method fo... The cephalopod beak is a vital hard structure with a stable configuration and has been widely used for the identification of cephalopod species. This study was conducted to determine the best standardization method for identifying different species by measuring 12 morphological variables of the beaks of Illex argentinus, Ommastrephes bartramii, and Dosidicus gigas that were collected by Chinese jigging vessels. To remove the effects of size, these morphometric variables were standardized using three methods. The average ratios of the upper beak morphological variables and upper crest length of O. bartramii and D. gigas were found to be greater than those of I. argentinus. However, for lower beaks, only the average of LRL(lower rostrum length)/LCL(lower crest length), LRW(lower rostrum width)/LCL, and LLWL(lower lateral wall length)/LCL of O. bartramii and D. gigas were greater than those of I. argentinus. The ratios of beak morphological variables and crest length were found to be all significantly different among the three species(P < 0.001). Among the three standardization methods, the correct classification rate of stepwise discriminant analysis(SDA) was the highest using the ratios of beak morphological variables and crest length. Compared with hood length, the correct classification rate was slightly higher when using beak variables standardized by crest length using an allometric model. The correct classification rate of the lower beak was also found to be greater than that of the upper beak. This study indicates that the ratios of beak morphological variables to crest length could be used for interspecies and intraspecies identification. Meanwhile, the lower beak variables were found to be more effective than upper beak variables in classifying beaks found in the stomachs of predators. 展开更多
关键词 BEAK standardized methodS DISCRIMINANT analysis Illex argentinus Ommastrephes bartramii Dosidicus GIGAS
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Improved EEMD-based standardization method for developing long tree-ring chronologies 被引量:6
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作者 Xianliang Zhang Junxia Li +1 位作者 Xiaobo Liu Zhenju Chen 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第6期2217-2224,共8页
Long tree-ring chronologies can be developed by overlapping data from living trees with data from fossil trees through cross-dating.However,low-frequency climate signals are lost when standardizing tree-ring series du... Long tree-ring chronologies can be developed by overlapping data from living trees with data from fossil trees through cross-dating.However,low-frequency climate signals are lost when standardizing tree-ring series due to the"segment length curse".To alleviate the segment length curse and thus improve the standardization method for developing long tree-ring chronologies,here we first calculated a mean value for all the tree ring series by overlapping all of the tree ring series.The growth trend of the mean tree ring width(i.e.,cumulated average growth trend of all the series)was determined using ensemble empirical mode decomposition.Then the chronology was developed by dividing the mean value by the growth trend of the mean value.Our improved method alleviated the problem of trend distortion.Long-term signals were better preserved using the improved method than in previous detrending methods.The chronologies developed using the improved method were better correlated with climate than those developed using conservative methods.The improved standardization method alleviates trend distortion and retains more of the low-frequency climate signals. 展开更多
关键词 standardization methods Tree rings Segment length curse DETRENDING
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Calculating the Number of Pregnant Women Receiving Standardized Services for PMTCT of HIV in Liangshan Prefecture,Based on the Equivalent Method 被引量:1
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作者 QU Shui Ling WANG Ai Ling +3 位作者 PAN Xiao Ping WANG Xiao Yan LUO Hui Ming ZHANG Tong 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2020年第10期745-749,共5页
Objective To calculate the number of pregnant women who receive standardized prevention of mother-to-child transmission(PMTCT)services for HIV annually.Methods HIV-positive pregnant women in six counties of Liangshan ... Objective To calculate the number of pregnant women who receive standardized prevention of mother-to-child transmission(PMTCT)services for HIV annually.Methods HIV-positive pregnant women in six counties of Liangshan Prefecture in 2017 were selected as study subjects.The entire process,from when the subjects first received the PMTCT of HIV services to the end,was divided into four stages,which were further divided into 25 phases.The equivalent coefficient was used to indicate the weight of workload in each phase.Seven experts were invited to score the equivalent coefficient;the number of pregnant women who received standardized services to prevent the transmission of HIV was calculated.Results A total of 663 HIV-positive pregnant women were registered in six Liangshan Prefecture counties in 2017.This figure was converted into 7,780 person-months devoted to HIV-positive pregnant women,with 260 person-months(3.34%)spent on the first antenatal care,1,510 person-months(19.41%)during pregnancy,378 person-months(4.86%)on delivery,and 5,632 person-months(72.39%)on post-partum period.The equivalent coefficient calculation showed that 314 HIV-positive pregnant women received standardized PMTCT services.Conclusion The number of pregnant women receiving standardized services for the PMTCT of HIV can be calculated accurately using the equivalent method to identify the gap between the level of PMTCT of HIV intervention services needed and the actual workload. 展开更多
关键词 Equivalent method standardized services PMTCT Pregnant women HIV
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Exploring the Application Effect of Flipped Classroom Combined with Problem-Based Learning Teaching Method in Clinical Skills Teaching of Standardized Training for Resident Doctors of Traditional Chinese Medicine 被引量:2
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作者 Jingjing Tang 《Journal of Biosciences and Medicines》 CAS 2023年第2期169-176,共8页
Objective: To explore the application effect of flipped classroom combined with problem-based learning teaching method in clinical skills teaching of standardized training for resident doctors of traditional Chinese M... Objective: To explore the application effect of flipped classroom combined with problem-based learning teaching method in clinical skills teaching of standardized training for resident doctors of traditional Chinese Medicine. Methods: The study used the experimental control method. The study lasted from September to November 2022. The subjects of this study were 49 students of standardized training for resident doctors of traditional Chinese Medicine from grades 2020, 2021 and 2022 of Dazhou integrated TCM & Western Medicine Hospital. They were randomly divided into experiment group (25) and control group (24). The experiment group adopted flipped classroom combined with problem-based learning teaching method, and the control group adopted traditional teaching method. The teaching content was 4 basic clinical skill projects, including four diagnoses of traditional Chinese Medicine, cardiopulmonary resuscitation, dressing change procedure, acupuncture and massage. The evaluation method was carried out by comparing the students’ performance and a self-designed questionnaire was used to investigate the students’ evaluation of the teaching method. Results: The test scores of total scores in the experimental group (90.12 ± 5.89) were all higher than those in the control group (81.47 ± 7.96) (t = 4.53, P P Conclusions: The teaching process of the flipped classroom combined with problem-based learning teaching method is conducive to improving the efficiency of classroom teaching, cultivating students’ self-learning ability, and enhancing students’ willingness to learn. 展开更多
关键词 standardized Training for Resident Doctors of Traditional Chinese Medicine Clinical Skills Teaching Flipped Classroom Problem-Based Learning Teaching method
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Current dependence coefficient determination for different DC standard resistors measurements based on Ⅴ-Ⅰ method 被引量:1
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作者 Rasha S M Ali M Helmy A Raouf 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第4期332-335,共4页
Current dependence and stability of the measured resistance value are very important for the accurate measurement of DC standard resistor. In this paper, the volt-ampere (V-I) measurement method has been applied ... Current dependence and stability of the measured resistance value are very important for the accurate measurement of DC standard resistor. In this paper, the volt-ampere (V-I) measurement method has been applied to study the current depend-ence of four different types of standard resistors. Diverse values are obtained through the investigation of their stability at dif-ferent currents. Therefore, the current dependence coefficient (CDC) can be determined for each one of the studied resistors. Research shows CDC depends on the applied current value, the measurement time and the resistor type, as clearly demonstra-ted in this research. 展开更多
关键词 current dependence coefficient standard resistors volt-ampere method resistor stability
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Smart Society and Artificial Intelligence:Big Data Scheduling and the Global Standard Method Applied to Smart Maintenance 被引量:1
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作者 Ruben Foresti Stefano Rossi +2 位作者 Matteo Magnani Corrado Guarino Lo Bianco Nicola Delmonte 《Engineering》 SCIE EI 2020年第7期835-846,共12页
The implementation of artificial intelligence(AI)in a smart society,in which the analysis of human habits is mandatory,requires automated data scheduling and analysis using smart applications,a smart infrastructure,sm... The implementation of artificial intelligence(AI)in a smart society,in which the analysis of human habits is mandatory,requires automated data scheduling and analysis using smart applications,a smart infrastructure,smart systems,and a smart network.In this context,which is characterized by a large gap between training and operative processes,a dedicated method is required to manage and extract the massive amount of data and the related information mining.The method presented in this work aims to reduce this gap with near-zero-failure advanced diagnostics(AD)for smart management,which is exploitable in any context of Society 5.0,thus reducing the risk factors at all management levels and ensuring quality and sustainability.We have also developed innovative applications for a humancentered management system to support scheduling in the maintenance of operative processes,for reducing training costs,for improving production yield,and for creating a human–machine cyberspace for smart infrastructure design.The results obtained in 12 international companies demonstrate a possible global standardization of operative processes,leading to the design of a near-zero-failure intelligent system that is able to learn and upgrade itself.Our new method provides guidance for selecting the new generation of intelligent manufacturing and smart systems in order to optimize human–machine interactions,with the related smart maintenance and education. 展开更多
关键词 Smart maintenance Smart society Artificial intelligence Human-centered management system Big data scheduling Global standard method Society 5.0 Industry 4.0
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Construction of nursing standard of integrated traditional Chinese and Western medicine for patients with COVID‑19 (mild and common) in Beijing based on Delphi method 被引量:2
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作者 Jing ZHANG Xue‑Ling MA +3 位作者 Jian‑Hua DENG Jing LI Zhi‑Yun ZHANG Ling TANG 《Journal of Integrative Nursing》 2020年第4期172-178,共7页
Objective:The objective of this study is to establish a nursing standard of integrated traditional Chinese and Western medicine for patients with COVID‑19(mild and common)in Beijing,to provide reference for clinical n... Objective:The objective of this study is to establish a nursing standard of integrated traditional Chinese and Western medicine for patients with COVID‑19(mild and common)in Beijing,to provide reference for clinical nursing of patients with COVID‑19(mild and common).Methods:Through online communication meeting with nurses who are in the frontline of anti‑epidemic,clinical investigation,literature research,and expert demonstration meeting are carried out to prepare the draft of the standard,and the Delphi method is applied to determine the standard of integrated traditional Chinese and Western medicine care for patients with COVID‑19(mild and common)in Beijing.Results:The nursing standard of integrated traditional Chinese and Western medicine for patients with COVID‑19(mild and common)was established,which included 5 first‑level indicators,14 second-level indicators and 60 third‑level indicators.After two rounds of Delphi method,the positive coefficients of experts were 96%and 83%,the authoritative coefficients of experts were 0.89 and 0.91,and the Kendall’s coefficient of concordance(W)of experts were 0.12,0.09,0.10,0.13(P<0.05)and 0.44,0.43,0.37,0.39(P<0.05).Conclusion:The standard of integrated traditional Chinese and Western medicine nursing for patients with COVID‑19(mild and common)in Beijing constructed by the Delphi method is scientific and practical,which provides a reference for clinical application of integrated traditional Chinese and Western medicine nursing to fight against COVID‑19 infection. 展开更多
关键词 COMMON COVID‑19 Delphi method integrated traditional Chinese and Western medicine nursing MILD nursing standard
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Analytical and Traveling Wave Solutions to the Fifth Order Standard Sawada-Kotera Equation via the Generalized exp(-Φ(ξ))-Expansion Method 被引量:1
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作者 M. Y. Ali M. G. Hafez +1 位作者 M. K. H. Chowdury M. T. Akter 《Journal of Applied Mathematics and Physics》 2016年第2期262-271,共10页
In this article, we propose a generalized exp(-Φ(ξ))-expansion method and successfully implement it to find exact traveling wave solutions to the fifth order standard Sawada-Kotera (SK) equation. The exact traveling... In this article, we propose a generalized exp(-Φ(ξ))-expansion method and successfully implement it to find exact traveling wave solutions to the fifth order standard Sawada-Kotera (SK) equation. The exact traveling wave solutions are established in the form of trigonometric, hyperbolic, exponential and rational functions with some free parameters. It is shown that this method is standard, effective and easily applicable mathematical tool for solving nonlinear partial differential equations arises in the field of mathematical physics and engineering. 展开更多
关键词 Generalized exp(-Φ(ξ))-Expansion method Fifth Order standard Sawada-Kotera Equation SOLITONS Periodic Wave Solutions
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Design Method of Equipment Optimization Development Based on Standardization Theory 被引量:2
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作者 Lv-bo MAI 《Defence Technology(防务技术)》 SCIE EI CAS 2013年第3期140-145,共6页
The matters of equipment optimization development are usually discrete,fuzzy and non-quantitative.It is difficult directly to optimize the equipment development with a mathematical model.A set of methods for designing... The matters of equipment optimization development are usually discrete,fuzzy and non-quantitative.It is difficult directly to optimize the equipment development with a mathematical model.A set of methods for designing the equipment optimization development with six dimensions and eight main elements is established based on the theory and method of standardization.The top-tier design space of systematic development of equipment is built up by the relations of basic models,series and model spectrums.The relations of time and space for equipment optimization development are established.The design processes of a six dimension systematic space are expounded.The connotation of each plan in the main system space is analyzed.A design method for an entire equipment is established with standardization theory.The coordinating design methods of equipment technical system and the optimization design methods of equipment integration are discussed.The design methods for universalization and serialization of components and parts are established.The design methods of equipment optimization development highlight the relations of the basic model of platform,the serialization of platform basic models,the modularization of equipment functions,the model spectrum of variant equipment,and the universalization and serialization of components and parts. 展开更多
关键词 优化设计方法 优化开发 化设备 标准化 优化发展 数学模型 设计空间 设备系统
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The Research on Methodology for Material Code Standardization in the Implementation of MRP-Ⅱ
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作者 孙虞 《Journal of Southeast University(English Edition)》 EI CAS 1996年第2期13-18,共6页
This paper analyses the current common problems of material code standardization in the implementation of MRP Ⅱ, and puts forward the basic ideas and methods for solving the problems, which has some reference value ... This paper analyses the current common problems of material code standardization in the implementation of MRP Ⅱ, and puts forward the basic ideas and methods for solving the problems, which has some reference value for the popularization of application o 展开更多
关键词 CODING standard methods
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Compilation Principles and Methods of China’s First Mongolian Standard in Meteorological Industry
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作者 Ying Chun Yu Gang Han Yanli 《Meteorological and Environmental Research》 CAS 2019年第4期118-121,共4页
Mongolian Terms Commonly Used in Meteorological Services that was issued by the China Meteorological Administration is China s first traditional Mongolian standard in meteorological industry. In the process of formula... Mongolian Terms Commonly Used in Meteorological Services that was issued by the China Meteorological Administration is China s first traditional Mongolian standard in meteorological industry. In the process of formulation, the compilation unit fully complied with the principles of scientificity, practicability, universality and versatility, and used literal translation, free translation, and the combination of literal translation and free translation to translate and compile 71 mongolian terms commonly used in meteorological services. The standard fills the blank of standardization construction of basic traditional Mongolian language in the meteorological industry of China. 展开更多
关键词 METEOROLOGY MONGOLIAN language standard COMPILATION PRINCIPLES and methodS
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LA-ICP-MS Calibrations for Intact Rock Samples with Internal Standard and Modified Constant-Sum Methods
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作者 Sheng Peng Qinhong Hu 《American Journal of Analytical Chemistry》 2012年第2期168-174,共7页
Laser ablation coupled with inductively coupled plasma-mass spectrometry (LA-ICP-MS) calibration was conducted with multiple spot analyses on eleven intact rock samples using both an internal standard (IS) method and ... Laser ablation coupled with inductively coupled plasma-mass spectrometry (LA-ICP-MS) calibration was conducted with multiple spot analyses on eleven intact rock samples using both an internal standard (IS) method and a modified constant-sum (MCS) method. Methods were then compared for reported bulk elemental composition of the rocks. The MCS method was based on the sum of eight major elements, which is spatially more stable than one single major ele-ment as used in the IS method, and is quite constant among different rock samples. Calibrations were performed with standard reference materials NIST SRM 610, 612, 614, and 616. Little difference was found between using a single standard and a set of standards, because of the good linearity shown by the reference materials. Comparison of the two calibration methods shows that the MCS method produced better and more stable results than the IS method for heterogeneous samples. With the MCS method, approximately 94% to 95% of the total measurements are within the range of ±100% relative deviation, compared with 82% to 86% with the IS method. The IS method resulted insubstantial overestimations for some rock samples (e.g., 648% for Basalt BCR-2 using NIST SRM 610 as the calibration standard), while the largest deviation with the MCS method was 216% for U in Eagle Ford shale #80 sample. For Quartz latite QLO-1, a relative homogeneous sample, the IS method generated slightly better results than the MCS method. Regardless of method, spatially heterogeneous distribution of elements in the intact rock at the scale of the laser spot is considered to be the main reason for the large relative deviations seen in our work compared to published results. 展开更多
关键词 LA-ICP-MS Quantitative Calibration Internal standard method MODIFIED Constant-Sum method
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Synthesis of an IS and Steviol Glycoside Analysis by a Validated Internal Standard Method
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作者 Jan M. C. Geuns Tom Struyf +2 位作者 Stijn Ceunen Gert Steurs Wim De Borggraeve 《American Journal of Analytical Chemistry》 2018年第11期547-559,共13页
The internal standard (IS) method is the best method for the analysis of samples, as it is independent of errors in injection volume, changes in sample volumes, and changes in sensitivity of the detector, etc. Use of ... The internal standard (IS) method is the best method for the analysis of samples, as it is independent of errors in injection volume, changes in sample volumes, and changes in sensitivity of the detector, etc. Use of an internal standard allows for the correction of losses due to sample clean-up of complex samples. An ideal IS is a compound that has properties very similar to, and that behaves as the compounds to be analysed. Ideally, only in the last step of analysis (HPLC), the IS should be well separated from the compounds of the mixture to be analysed. After testing several existing compounds with negative results, we decided to synthesise the 19-O-β-D-galactopyranosyl-13-O-β-D-glucopyranosyl-steviol as IS. This is the 19-galactosyl ester of steviolmonoside (13-O-β-D-glucopyranosyl-steviol). The IS was made according to published methods. Steviolmonoside (SM) was made from purified commercial rubusoside (Rub) by refluxing it in 10% KOH for 2 h. SM was precipitated and crystallized from MeOH. The hydroxyls of the glucose unit of SM were protected by acetylation. The acetylated SM was crystallized from acetone and dissolved in 1,2-dichloroethane. Then Ag2CO3 on Celite and tetra-acetylated galactopyranosyl bromide were added and the mixture was refluxed for 2 h. After cooling, BaO in MeOH was added to remove the acetyl groups. The 1,2-dichloroethane fraction was then extracted three times with equal volumes of water and the water fraction containing the IS was further purified on a C18 flash chromatography column. Traces of unreacted SM were removed by preparative HPLC on an Alltima C18 column (250 mm × 22 mm, particle size 10 μm) with AcCN:water (35:65, 20 ml/min). Detection was at 210 nm (KNAUER, “Smartline” UV detector 2500). The collected IS fraction from the HPLC was completely dried. Mixtures of steviol glycosides (SVglys) containing IS could be purified over SPE cartridges without change of the SVgly over IS ratio. The calibration curves for rebaudioside A (RebA) and stevioside (ST) were linear between 0.012 and 0.95 and between 0.013 and 1.13 mM for RebA and ST, respectively. The accuracy was checked by the standard addition method. It was concluded that the IS method gives an excellent precision and accuracy. 展开更多
关键词 STEVIOL GLYCOSIDES INTERNAL standard method VALIDATION Quantification PURIFICATION
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The Measurement and Uncertainty Analysis of Antenna Factor of Microwave Antennas Based on Standard Site Method
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作者 Chaochan Chen Hong Shi +1 位作者 Yi Miao Yu Sang 《International Journal of Communications, Network and System Sciences》 2017年第5期138-145,共8页
A method of Standard Site Method (SSM) in the American National Standards Institute’s ANSI C63.5 is described in the frequency ranges from 30 MHz to 1000 MHz. And a measurement system is set up for determining antenn... A method of Standard Site Method (SSM) in the American National Standards Institute’s ANSI C63.5 is described in the frequency ranges from 30 MHz to 1000 MHz. And a measurement system is set up for determining antenna factors (AF) of antennas on an Open Area Test Sites (OATS). AF of antennas including log-periodic antenna and biconical antenna is measured with SSM method by Shanghai Institute of Measurement and Testing Technology (SIMT), which shows good agreement to data measured by National Institute of Metrology (NIM). In the end, it analyzes the measurement uncertainty of SIMT in the 30 MHz to 1000 MHz frequency band and does comparison to that of NIM. 展开更多
关键词 ANTENNA FACTORS standard SITE method (SSM) MEASUREMENT UNCERTAINTY
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