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A Review on Sources,Extractions and Analysis Methods of a Sustainable Biomaterial:Tannins 被引量:2
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作者 Antonio Pizzi Marie-Pierre Laborie Zeki Candan 《Journal of Renewable Materials》 EI CAS 2024年第3期397-425,共29页
Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly ... Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly to substitute petroleum-based products.They are a definite class of sustainable materials of the forestry industry.They have been in operation for hundreds of years to manufacture leather and now for a growing number of applications in a variety of other industries,such as wood adhesives,metal coating,pharmaceutical/medical applications and several others.This review presents the main sources,either already or potentially commercial of this forestry by-materials,their industrial and laboratory extraction systems,their systems of analysis with their advantages and drawbacks,be these methods so simple to even appear primitive but nonetheless of proven effectiveness,or very modern and instrumental.It constitutes a basic but essential summary of what is necessary to know of these sustainable materials.In doing so,the review highlights some of the main challenges that remain to be addressed to deliver the quality and economics of tannin supply necessary to fulfill the industrial production requirements for some materials-based uses. 展开更多
关键词 TANNINS FLAVONOIDS SOURCES extraction methods analysis methods
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Determination of Fe and Zn contents and distributions in natural sphalerite/marmatite by various analysis methods 被引量:7
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作者 Hao LAI Jiu-shuai DENG +2 位作者 Zi-long LIU Shu-ming WEN Ling-yun HUANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第5期1364-1374,共11页
The contents of Fe and Zn in natural sphalerite samples were determined by chemical titration and spectroscopic techniques(portable X-ray fluorescence(P-XRF) spectrometry, electron probe microanalysis with energy disp... The contents of Fe and Zn in natural sphalerite samples were determined by chemical titration and spectroscopic techniques(portable X-ray fluorescence(P-XRF) spectrometry, electron probe microanalysis with energy dispersive spectroscopy(EPMA-EDS), electron probe microanalysis with wavelength dispersive spectroscopy(EPMA-WDS), and time-of-flight secondary ion mass spectrometry(To F-SIMS)). Besides, the distribution of Fe and Zn in sphalerite samples was analyzed by imaging EPMA-WDS and imaging To F-SIMS. The results show that Fe and Zn contents determined by each spectroscopic technique have good linearity with those determined by chemical titration(R^2>0.77), and the R^2 values of Fe are generally greater than those of Zn. The imaging analysis results revealed that Fe and Zn are not uniformly distributed in the sphalerite. 展开更多
关键词 SPHALERITE MARMATITE FE Zn analysis methods imaging
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Overview of Precious Metal Content Analysis Methods in Automotive Catalytic Converter 被引量:1
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作者 Xianpeng Yang Chengbao Xie +4 位作者 Ning Liu Xin Du Suqing Wang Huasheng Jiang Zhengang Zhang 《Journal of Materials Science and Chemical Engineering》 2023年第11期7-14,共8页
With the increasing awareness of environmental protection, people’s concern of pollution issues arising. Vehicles, as the most important means of transportation, its exhaust emission has received considerable attenti... With the increasing awareness of environmental protection, people’s concern of pollution issues arising. Vehicles, as the most important means of transportation, its exhaust emission has received considerable attention. The catalytic converter is able to purify harmful substances in exhaust gas. The absolute content of precious metals in the catalytic converter dominates the exhaust gas purification effect. Accurate detection of precious metal content is of great significance for controlling the cost of catalysts, ensuring catalytic performance and recovering precious metals from spent catalysts. We herein summarized several instruments for precious metals content exploration, such as X-ray fluorescence spectrometer (XRF), atomic absorption spectrometer (AAS), inductively coupled plasma emission spectrometer (ICP) and spectrophotometer. In this thesis, the feasibility of using various devices for characterizing precious metal content in catalytic converters is analyzed and their strengths or weaknesses are elaborated. 展开更多
关键词 Catalytic Converter Precious Metal Content analysis methods
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Utilizing comprehensive decision analysis methods to determine an optimal planting pattern and nitrogen application for winter oilseed rape 被引量:3
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作者 DU Ya-dan CUI Bing-jing +3 位作者 ZHANG Qian SUN Jun WANG Zhen NIU Wen-quan 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第9期2229-2238,共10页
Oilseed rape is one of the most important oil crops globally.Attaining the appropriate cultivation method(planting pattern and nitrogen level)is necessary to achieve high yield,quality and resource utilization efficie... Oilseed rape is one of the most important oil crops globally.Attaining the appropriate cultivation method(planting pattern and nitrogen level)is necessary to achieve high yield,quality and resource utilization efficiency.However,the optimal method for oilseed rape varies across countries and regions.The objective of the present study was to determine an appropriate cultivation method,including planting pattern and nitrogen application,for winter oilseed rape in northwestern China.Two planting patterns:ridge film mulching and furrow planting(RFMF)and flat planting(FP),and six nitrogen(N)amounts:0(N0),60(N60),120(N120),180(N180),240(N240),and 300(N300)kg N ha–1 were applied across three growing seasons(2014–2017).Three comprehensive decision analysis methods:principal component analysis,grey correlation degree analysis and the combined entropy weight and dynamic technique for order preference by similarity to ideal solution method were used to evaluate the growth and physiological indicators,nutrient uptake,yield,quality,evapotranspiration,and water use efficiency of winter oilseed rape.Planting pattern,nitrogen amount and their interaction significantly affected the indicators aforementioned.The RFMF pattern significantly increased all indicators over the FP pattern.Application of N also markedly increased all the indicators except for seed oil content,but the yield,oil production and water use efficiency were decreased when N fertilizer exceeded 180 kg N ha–1 under FP and 240 kg N ha–1 under RFFM.The evaluation results of the three comprehensive decision analysis methods indicated that RFMF planting pattern with 240 kg N ha–1 is an appropriate cultivation method for winter oilseed rape in northwestern China.These findings are of vital significance to maximize yield,optimize quality and improve resource use efficiencies of winter oilseed rape. 展开更多
关键词 appropriate cultivation method comprehensive decision analysis method northwestern China winter oilseed rape
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Sensitivity and inverse analysis methods for parameter intervals
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作者 Guojian Shao Jingbo Su 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2010年第3期274-280,共7页
This paper proposes a sensitivity analysis method for engineering parameters using interval analyses.This method substantially extends the application of interval analysis method.In this scheme,parameter intervals and... This paper proposes a sensitivity analysis method for engineering parameters using interval analyses.This method substantially extends the application of interval analysis method.In this scheme,parameter intervals and decision-making target intervals are determined using the interval analysis method.As an example,an inverse analysis method for uncertainty is presented.The intervals of unknown parameters can be obtained by sampling measured data.Even for limited measured data,robust results can also be obtained with the inverse analysis method,which can be intuitively evaluated by the uncertainty expressed in terms of an interval.For complex nonlinear problems,an iteratively optimized inverse analysis model is proposed.In a given set of loose parameter intervals,all the unknown parameter intervals that satisfy the measured information can be obtained by an iteratively optimized inverse analysis model.The influences of measured precisions and the number of parameters on the results of the inverse analysis are evaluated.Finally,the uniqueness of the interval inverse analysis method is discussed. 展开更多
关键词 interval analysis method sensitivity analysis reversible inverse analysis method iteratively optimized inverse analysis method
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Introducing Adaptive Analysis Methods: The Present Analysis &Future Analysis
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作者 Kunto Wibowo Agung Prodjonoto 《Journal of Analytical Sciences, Methods and Instrumentation》 2020年第2期43-57,共15页
Mastery of theory, analysis, approach models and decision making, is increasingly important, so finding analytical methods to achieve something better is a logical consequence. For this reason, adaptive analysis metho... Mastery of theory, analysis, approach models and decision making, is increasingly important, so finding analytical methods to achieve something better is a logical consequence. For this reason, adaptive analysis method is introduced, which is a method of dynamizing SWOT analysis using commutative properties with the operation of the cross-axis coordinate (X;Y), based on the theory of lines and rules of a sword, phenomenal, natural and relevant, to obtain a grand strategy chosen as a unified strategy like two sides of a coin. The method used is the theoretical and empirical study of adaptive analysis on one of the global issues, namely phenomenal terrorism until now. It is hoped that this method can be used in a variety of problems and is highly determined how a talent plays a role and is not intended to criticize existing analytical methods that have been used. 展开更多
关键词 Decision Making Adaptive analysis Method
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Research Progress on the Pharmacological Effects and Quality Analysis Methods of Bupleurum
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作者 Kai Zhang Xianling Zheng +4 位作者 Hongfeng Zhang Xueqiang Zhang Yanmin Xu Shiying Jin Shuang Huo 《Journal of Clinical and Nursing Research》 2022年第3期7-13,共7页
Bupleurum has been used as traditional medicine in China,Japan,South Korea,and other Asian countries for more than 2,000 years.The crude extracts and pure compounds isolated from Bupleurum have a variety of biological... Bupleurum has been used as traditional medicine in China,Japan,South Korea,and other Asian countries for more than 2,000 years.The crude extracts and pure compounds isolated from Bupleurum have a variety of biological activities,such as anti-inflammatory,anti-cancer,antipyretic,antibacterial,anti-viral,liver protection,neuroprotection,and immune regxilation.The pharmacological effects of Bupleurum have been classified and summarized in this paper by consulting literatures at home and abroad.At the same time,the quality analysis methods of bupleurum,including high-performance liquid chromatography,thin layer chromatography,ultra-high-performance liquid chromatography mass spectrometry,UPLC-QTOF-MS,and so on,are discussed.This paper provides a reference for further research,development,and application of Bupleurum. 展开更多
关键词 BUPLEURUM Pharmacological action Quality analysis method Research progress
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Risk analysis methods of the water resources system under uncertainty 被引量:1
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作者 Zeying GUI Chenglong ZHANG +1 位作者 Mo LI Ping GUO 《Frontiers of Agricultural Science and Engineering》 2015年第3期205-215,共11页
The main characteristic of the water resources system(WRS)is its great complexity and uncertainty,which makes it highly desirable to carry out a risk analysis of the WRS.The natural environmental,social economic condi... The main characteristic of the water resources system(WRS)is its great complexity and uncertainty,which makes it highly desirable to carry out a risk analysis of the WRS.The natural environmental,social economic conditions as well as limitations of human cognitive ability are possible sources of the uncertainties that need to be taken into account in the risk analysis process.In this paper the inherent stochastic uncertainty and cognitive subjective uncertainty of the WRS are discussed first,from both objective and subjective perspectives.Then the quantitative characterization methods of risk analysis are introduced,including three criteria(reliability,resiliency and vulnerability)and five basic optimization models(the expected risk value model,conditional value at risk model,chance-constrained risk model,minimizing probability of risk events model,and the multi-objective optimization model).Finally,this paper focuses on the various methods of risk analysis under uncertainty,which are summarized as random,fuzzy and mixed methods.A more comprehensive risk analysis methodology for the WRS is proposed based on the comparison of the advantages,disadvantages and applicable conditions of these three methods.This paper provides a decision support of risk analysis for researchers,policy makers and stakeholders of the WRS. 展开更多
关键词 water resources system evaluation criterion optimization model risk analysis method UNCERTAINTY
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Mechanical Analysis Methods of Cantilever Gearbox Housing
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作者 王珏 李朋 宋诗瑶 《Journal of Shanghai Jiaotong university(Science)》 EI 2023年第2期233-242,共10页
The mechanical state of cantilever gearbox housing is different from ordinary ones due to the long arm of force caused by cantilever structure.Conventional mechanical analysis methods either took cantilever gearbox ho... The mechanical state of cantilever gearbox housing is different from ordinary ones due to the long arm of force caused by cantilever structure.Conventional mechanical analysis methods either took cantilever gearbox housing as ordinary ones or cantilever beam.Few published papers have specially focused on mechanical analysis method for cantilever gearbox housing.This paper takes a longwall shearer cutting unit gearbox(SCUG)as an example and the mechanical analysis method is investigated according to the causes of fatigue for SCUG.Force analysis model is established for finding out regions of static fatigue caused by low-frequency loads,and local resonance analysis is used for finding out regions of vibration fatigue caused by high-frequency loads.Not only bending moment but also torque caused by gear meshing forces is taken into account in the force analysis model.Vibration response is obtained from cutting experiment,and dominant frequencies of local resonance are obtained by frequency domain analysis.Finite element model of SCUG is established,and natural frequencies and strain modes are analyzed for obtaining the main vibration modes corresponding to dominant frequencies.Hence,large stress regions caused by low and high frequency loads are obtained.Results show that the worst working condition is oblique cutting,and the stress of B-B in 600 mm cutting depth can reach 166 MPa.Obviously,950 Hz,1250 Hz,and 1400 Hz are dominant frequencies of SCUG(23rd,25th and 27th natural frequencies).Generally,this paper proposes some principles for mechanical analysis method of cantilever gearbox housing. 展开更多
关键词 cantilever gearbox housing mechanical analysis method static fatigue vibration fatigue dynamic characteristics cutting experiment
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Comprehensive Analysis Method of Slope Stability Based on the Limit Equilibrium and Finite Element Methods and Its Application
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作者 Yajun Wang Yifeng Li Jinzhou Chen 《Open Journal of Civil Engineering》 2023年第4期555-571,共17页
To study the safety and stability of large slopes, taking the right side slope of the Yuxi’an tunnel of the Yuchu Expressway Bridge in Yunnan Province as an example, limit equilibrium and finite element analysis were... To study the safety and stability of large slopes, taking the right side slope of the Yuxi’an tunnel of the Yuchu Expressway Bridge in Yunnan Province as an example, limit equilibrium and finite element analysis were applied to engineering examples to calculate the stability coefficient of the slope before and after excavation in the natural state. After comparative analysis, it was concluded that the former had a clear mechanical model and concept, which could quickly provide stability results;the latter could accurately determine the sliding surface of the slope and simulate the stress state changes of the rock and soil mass. The stability coefficients calculated by the two methods were within the stable range, but their values were different. On this basis, combined with the calculation principles, advantages and disadvantages of the two methods, a comprehensive analysis method of slope stability based on the limit equilibrium and finite element methods was proposed, and the rationality of the stability coefficient calculated by this method was judged for a slope case. 展开更多
关键词 Slope Body Excavation Mechanical Model Sliding Surface Coefficient of Stability Calculation Principle Comprehensive analysis Method
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Comparison of methods for vibration analysis of electrostatic precipitators
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作者 Iwona Adamiec-Wójcik Andrzej Nowak Stanisaw Wojciech 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第1期72-79,共8页
The paper presents two methods for the formulation of free vibration analysis of collecting electrodes of precipitators.The first,called the hybrid finite element method, combines the finit element method used for cal... The paper presents two methods for the formulation of free vibration analysis of collecting electrodes of precipitators.The first,called the hybrid finite element method, combines the finit element method used for calculations of spring deformations with the rigid finite element method used to reflect mass and geometrical features,which is called the hybrid finite element method.As a result,a model with a diagonal mass matrix is obtained.Due to a specific geometry of the electrodes,which are long plates of complicated shapes,the second method proposed is the strip method which is a semi-analytical method.The strip method allows us to formulate the equations of motion with a considerably smaller number of generalized coordinates.Results of numerical calculations obtained by both methods are compared with those obtained using commercial software like ANSYS and ABAQUS.Good compatibility of results is achieved. 展开更多
关键词 Finite element method · Rigid finite element method · Strip method · Free vibration analysis · Electrostatic precipitators
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Quantitative Analysis of Seeing with Height and Time at Muztagh-Ata Site Based on ERA5 Database
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作者 Xiao-Qi Wu Cun-Ying Xiao +3 位作者 Ali Esamdin Jing Xu Ze-Wei Wang Luo Xiao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第1期87-95,共9页
Seeing is an important index to evaluate the quality of an astronomical site.To estimate seeing at the Muztagh-Ata site with height and time quantitatively,the European Centre for Medium-Range Weather Forecasts reanal... Seeing is an important index to evaluate the quality of an astronomical site.To estimate seeing at the Muztagh-Ata site with height and time quantitatively,the European Centre for Medium-Range Weather Forecasts reanalysis database(ERA5)is used.Seeing calculated from ERA5 is compared consistently with the Differential Image Motion Monitor seeing at the height of 12 m.Results show that seeing decays exponentially with height at the Muztagh-Ata site.Seeing decays the fastest in fall in 2021 and most slowly with height in summer.The seeing condition is better in fall than in summer.The median value of seeing at 12 m is 0.89 arcsec,the maximum value is1.21 arcsec in August and the minimum is 0.66 arcsec in October.The median value of seeing at 12 m is 0.72arcsec in the nighttime and 1.08 arcsec in the daytime.Seeing is a combination of annual and about biannual variations with the same phase as temperature and wind speed indicating that seeing variation with time is influenced by temperature and wind speed.The Richardson number Ri is used to analyze the atmospheric stability and the variations of seeing are consistent with Ri between layers.These quantitative results can provide an important reference for a telescopic observation strategy. 展开更多
关键词 site testing atmospheric effects methods:data analysis telescopes EARTH
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Observation and Analysis of VLF Nocturnal Multimode Interference Phenomenon based on Waveguide Mode Theory
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作者 Sai Yang You-Tian Niu +5 位作者 Zhe Wang Xiu-Kun Zhao Bei Li Yu-Ling Ding Ge-Ge Zhao An-Qi Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第1期78-86,共9页
Very low frequency(VLF)signals are propagated between the ground-ionosphere.Multimode interference will cause the phase to show oscillatory changes with distance while propagating at night,leading to abnormalities in ... Very low frequency(VLF)signals are propagated between the ground-ionosphere.Multimode interference will cause the phase to show oscillatory changes with distance while propagating at night,leading to abnormalities in the received VLF signal.This study uses the VLF signal received in Qingdao City,Shandong Province,from the Russian Alpha navigation system to explore the multimode interference problem of VLF signal propagation.The characteristics of the effect of multimode interference phenomena on the phase are analyzed according to the variation of the phase of the VLF signal.However,the phase of VLF signals will also be affected by the X-ray and energetic particles that are released during the eruption of solar flares,therefore the two phenomena are studied in this work.It is concluded that the X-ray will not affect the phase of VLF signals at night,but the energetic particles will affect the phase change,and the influence of energetic particles should be excluded in the study of multimode interference phenomena.Using VLF signals for navigation positioning in degraded or unavailable GPS conditions is of great practical significance for VLF navigation systems as it can avoid the influence of multimode interference and improve positioning accuracy. 展开更多
关键词 WAVES methods:data analysis Sun:flares Sun:X-rays GAMMA-RAYS
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Analysis of the Conditional Correlations from Different Genetic Systems Between the Protein Content and the Appearance Quality Traits of Indica Rice 被引量:4
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作者 葛国科 郑希 +2 位作者 吴建国 叶子弘 石春海 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第2期129-137,共9页
A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines (A) and 5 restorer lines (R) along with their F1 (A × R) and F2 populations. The unconditional and conditio... A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines (A) and 5 restorer lines (R) along with their F1 (A × R) and F2 populations. The unconditional and conditional analyses of genetic models and the corresponding statistic methods, including endospermic, cytoplasmic, and maternal plant genetic systems, were used to analyze the genetic relationships between protein content (PC) and the appearance quality traits of indica rice (Oryza sativa L.). The results from unconditional analysis indicated that PC was significantly correlated with the appearance quality traits of rice, except for the brown rice thickness (BRT). Only the genetic covariance between PC and the brown rice width (BRW) was positively correlative, whereas all the other pairwise traits were negatively correlative. The results from conditional analysis revealed that the weight of brown rice (WBR) or the amylose content (AC) could significantly affect the relationships between PC and the appearance quality traits of indica rice. The conditional analysis showed that WBR might negatively affect the relationships between PC and the brown rice length (BRL), BRW, or BRT through the geuotype x environmental (GE) interaction effects, but positively affected the relationships between PC and the ratio of brown rice length to width (RLW) or the ratio of brown rice length to thickness (RLT). The amylase content could positively affect the relationships between PC and BRL, RLW, RLT through the cytoplasmic effects and maternal additive effects, but negatively affected the relationships between PC and BRW. 展开更多
关键词 indica rice (Oryza sativa L.) COVARIANCE unconditional and conditional analysis methods protein content amylose content appearance quality
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Dynamic Analysis of Customer Demand Based on Intuitionistic Fuzzy Number in Product Planning
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作者 Yongguang Yi Zengqiang Wang 《Proceedings of Business and Economic Studies》 2024年第5期127-131,共5页
To address the fuzziness and variability in determining customer demand importance,a dynamic analysis method based on intuitionistic fuzzy numbers is proposed.First,selected customers use intuitionistic fuzzy numbers ... To address the fuzziness and variability in determining customer demand importance,a dynamic analysis method based on intuitionistic fuzzy numbers is proposed.First,selected customers use intuitionistic fuzzy numbers to represent the importance of each demand.Then,the preference information is aggregated using customer weights and time period weights through the intuitionistic fuzzy ordered weighted average operator,yielding a dynamic vector of the subjective importance of the demand index.Finally,the feasibility of the proposed method is demonstrated through an application example of a vibrating sorting screen. 展开更多
关键词 Quality function deployment Customer demand Intuitionistic fuzzy number Dynamic analysis method
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Conceptual Analysis of Self-Management in Patients with Hypertension
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作者 Li Yang Yutian Hao +4 位作者 Liling Zhong Shilin Xu Saiqiong Zhong Yanying Lu Hui Liu 《Journal of Clinical and Nursing Research》 2024年第5期356-368,共13页
Objective:To clarify the concept of self-management in hypertensive patients by analyzing the definition,attributes,and measurement tools through a literature review.Methods:An Internet-based search of the databases w... Objective:To clarify the concept of self-management in hypertensive patients by analyzing the definition,attributes,and measurement tools through a literature review.Methods:An Internet-based search of the databases was conducted using Academic Search Complete,Medical Line,CINAHL,Health Source:Nursing/Scholarly Edition,and Google Scholar.In the search process,keywords or free text were combined by using Boolean operators,with the search terms“self of management”or“self-management,”“concept*analysis”or“concept*definition,”and Walker and Avant’s concept analysis method was used.Results:Analysis of relevant literature summarized the conceptual attributes of self-management in hypertensive patients as the active participation of patients in the treatment process;the presence of interaction provided by patients and health care providers;the use of certain health management tools;and the aim of maintaining and improving the health status and living capacity of hypertensive patients.Conclusion:The concept of self-management for hypertensive patients was clarified,which helps to promote the application of hypertensive self-management in clinical work and improve outcomes and quality of life for patients with hypertension. 展开更多
关键词 HYPERTENSION SELF-MANAGEMENT Concept analysis Walker and Avant’s concept analysis method
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Mathematical Tools of Cluster Analysis 被引量:9
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作者 Peter Trebuna Jana Halcinova 《Applied Mathematics》 2013年第5期814-816,共3页
The paper deals with cluster analysis and comparison of clustering methods. Cluster analysis belongs to multivariate statistical methods. Cluster analysis is defined as general logical technique, procedure, which allo... The paper deals with cluster analysis and comparison of clustering methods. Cluster analysis belongs to multivariate statistical methods. Cluster analysis is defined as general logical technique, procedure, which allows clustering variable objects into groups-clusters on the basis of similarity or dissimilarity. Cluster analysis involves computational procedures, of which purpose is to reduce a set of data on several relatively homogenous groups-clusters, while the condition of reduction is maximal and simultaneously minimal similarity of clusters. Similarity of objects is studied by the degree of similarity (correlation coefficient and association coefficient) or the degree of dissimilarity-degree of distance (distance coefficient). Methods of cluster analysis are on the basis of clustering classified as hierarchical or non-hierarchical methods. 展开更多
关键词 Cluster analysis Hierarchical Cluster analysis methods Non-Hierarchical Cluster analysis methods
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Dynamic analysis and experimental study of vibro-acoustic system with uncertainties at middle frequencies 被引量:2
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作者 焦仁强 张建润 薛飞 《Journal of Southeast University(English Edition)》 EI CAS 2017年第2期166-170,共5页
To take into account the influence of uncetainties on the dynamic response of the vibro-acousitc structure, a hybrid modeling technique combining the finite element method(FE)and the statistic energy analysis(SEA)... To take into account the influence of uncetainties on the dynamic response of the vibro-acousitc structure, a hybrid modeling technique combining the finite element method(FE)and the statistic energy analysis(SEA) is proposed to analyze vibro-acoustics responses with uncertainties at middle frequencies. The mid-frequency dynamic response of the framework-plate structure with uncertainties is studied based on the hybrid FE-SEA method and the Monte Carlo(MC)simulation is performed so as to provide a benchmark comparison with the hybrid method. The energy response of the framework-plate structure matches well with the MC simulation results, which validates the effectiveness of the hybrid FE-SEA method considering both the complexity of the vibro-acoustic structure and the uncertainties in mid-frequency vibro-acousitc analysis. Based on the hybrid method, a vibroacoustic model of a construction machinery cab with random properties is established, and the excitations of the model are measured by experiments. The responses of the sound pressure level of the cab and the vibration power spectrum density of the front windscreen are calculated and compared with those of the experiment. At middle frequencies, the results have a good consistency with the tests and the prediction error is less than 3. 5dB. 展开更多
关键词 hybrid finite element method and statistic energy analysis(FE-SEA) method dynamic analysis vibroacoustic system UNCERTAINTIES mid-frequency range
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Simulation of a torrential rainstorm in Xinjiang and gravity wave analysis 被引量:4
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作者 Rui Yang Yi Liu +1 位作者 Ling-Kun Ran Yu-Li Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第5期573-580,共8页
We used a weather research and forecasting model to simulate a torrential rainstorm that occurred in Xinjiang,China during June 16–17,2016.The model successfully simulated the rainfall area,precipitation intensity,an... We used a weather research and forecasting model to simulate a torrential rainstorm that occurred in Xinjiang,China during June 16–17,2016.The model successfully simulated the rainfall area,precipitation intensity,and changes in precipitation.We identified a clear wave signal using the two-dimensional fast Fourier transform method;the waves propagated westwards,with wavelengths of 45–20 km,periods of 50–120 min,and phase velocities mainly concentrated in the-25 m/s to-10 m/s range.The results of wavelet cross-spectral analysis further confirmed that the waves were gravity waves,peaking at 11:00 UTC,June 17,2016.The gravity wave signal was identified along 79.17–79.93°E,81.35–81.45°E and 81.5–81.83°E.The gravity waves detected along 81.5–81.83°E corresponded well with precipitation that accumulated in 1 h,indicating that gravity waves could be considered a rainstorm precursor in future precipitation forecasts. 展开更多
关键词 gravity wave RAINSTORM spectral analysis methods weather research and forecasting model
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VIBRATION MODE ANALYSIS OF MULTILAYERED COMPOSITE PLATES AND SHELLS USING NATURAL APPROACH
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作者 朱金福 王永亮 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1995年第2期114-121,共8页
Argyris'natural approach is employed to analyze vibranon mode of multilayered composite plates and shells.The shells can be either symmetric or unsymmetric.The spectral transformation Lanczos method with selective... Argyris'natural approach is employed to analyze vibranon mode of multilayered composite plates and shells.The shells can be either symmetric or unsymmetric.The spectral transformation Lanczos method with selective or fully orthogonalization is used to solve the eigenvalue problem of pencil(K,M).Some problems on shift,which is essential for the success of this method, are discussed.A few numerical examples, including composite square plates and conical shells,are presented. The results show that the method in this paper is efficient and reliable for vibration mode analysis. 展开更多
关键词 vibration analysis method composite materials PLATES Lanczos method natural approach
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