期刊文献+
共找到7,113篇文章
< 1 2 250 >
每页显示 20 50 100
Comparative Analysis on Physical Quantity Diagnosis and Wind Profile Radar Data of Two Heavy Rainfalls
1
作者 Yunfeng Zhu Mengxi Yang +2 位作者 Jie Liu Beiyuan Wang Haiwei Duo 《Meteorological and Environmental Research》 CAS 2013年第5期9-13,16,共6页
[ Objective] The research aimed to contrast physical quantity diagnosis and wind profile radar data of two heavy rainfalls. [ Method ] From circulation background, physical quantity field and wind profile radar data, ... [ Objective] The research aimed to contrast physical quantity diagnosis and wind profile radar data of two heavy rainfalls. [ Method ] From circulation background, physical quantity field and wind profile radar data, we analyzed two big rainstorm weather processes (8 -9 July and August 10) in Lianyungang City in 2012. [ Result] Rainstorm generation was related to favorable large-scale circulation situation. The first-stage precipitation during 8 -9 July was warm-zone precipitation, and the precipitation at the second stage was triggered by shear line. Precipitation on August 10 was generated by typhoon low-pressure inverted trough and cold air. Sufficient water vapor content and strong water vapor transportation were favorable for generation of the heavy precipitation. Suction effect by divergence at high layer and convergence at middle and low layers was favorable for maintenance of the strong ascending motion. Occurrence of the heavy precipitation must have ascending motion condition. But it was not that the stronger the ascending motion, the stronger the rainfall intensity. Kindex and θse500 -θse 850 were closely related to rainstorm occurrence. Horizontal wind data of the wind profile radar provided fine structure of the atmospheric horizontal motion at vertical direction, could clearly display vertical structure of the wind field in rainstorm process, and directly reflected change characteristics of the wind field in precipitation process. [ Conclusion] The research could provide reference for future forecast work. 展开更多
关键词 Heavy rainfall Circulation background physical quantity field Wind profile radar China
下载PDF
The Impact of Big Five Personality Traits on Older Europeans’ Physical Health
2
作者 Eleni Serafetinidou Christina Parpoula 《Journal of Biomedical Science and Engineering》 2024年第2期41-56,共16页
Investigating the role of Big Five personality traits in relation to various health outcomes has been extensively studied. The impact of “Big Five” on physical health is here explored for older Europeans with a focu... Investigating the role of Big Five personality traits in relation to various health outcomes has been extensively studied. The impact of “Big Five” on physical health is here explored for older Europeans with a focus on examining age groups differences. The study sample included 378,500 respondents derived from the seventh data wave of Survey of Health, Aging and Retirement in Europe (SHARE). The physical health status of older Europeans was estimated by constructing an index considering the combined effect of well-established health indicators such as the number of chronic diseases, mobility limitations, limitations with basic and instrumental activities of daily living, and self-perceived health. This index was used for an overall physical health assessment, for which the higher the score for an individual, the worst health level. Then, through a dichotomization process applied to the retrieved Principal Component Analysis scores, a two-group discrimination (good or bad health status) of SHARE participants was obtained as regards their physical health condition, allowing for further con-structing logistic regression models to assess the predictive significance of “Big Five” and their protective role for physical health. Results showed that neuroti-cism was the most significant predictor of physical health for all age groups un-der consideration, while extraversion, agreeableness and openness were not found to significantly affect the self-reported physical health levels of midlife adults aged 50 up to 64. Older adults aged 65 up to 79 were more prone to open-ness, whereas the oldest old individuals aged 80 up to 105 were mainly affected by openness and conscientiousness. . 展开更多
关键词 Big Five Personality Traits physical Health Older Europeans SHARE Principal Component analysis
下载PDF
Analysis of a New Toothbrushing Technique through Plaque Removal Success
3
作者 Elhadi A. A. Shkorfu Serkan Kurt +2 位作者 Fatih Atalar Ali Olamat Aysel Ersoy 《Open Journal of Stomatology》 2024年第3期133-152,共20页
Background/Aims: Determining the levels of oral health and the quality of dental care are fundamental to building concepts of oral health. This study aims to assess toothbrushing techniques using a technical and physi... Background/Aims: Determining the levels of oral health and the quality of dental care are fundamental to building concepts of oral health. This study aims to assess toothbrushing techniques using a technical and physical model, clarifying how children and pre-adults learn to brush their teeth. Materials and Methods: Data were recorded from 23 participants, both male and female of various ages, using a proposed electronic toothbrush equipped with X-Y-Z axes pathways. The data, collected before and after training experiments, were processed with MATLAB to generate plots for the three axes. Results: The study revealed that most parameter values, such as Mean Difference Between Amplitudes (MAV, 6.00), Wilson Amplitude (WAMP, 179.419), and Average Amplitude Coupling (AAC, 1.270), decreased from before to after the experiments. Furthermore, the average overall epoch lengths (AVG) showed a 75% reduction in movement amplitude between the two experiments. Conclusion: Dentist observations indicated which brushing methods were acceptable or not. Analytical values suggest that individuals learn the toothbrushing technique effectively, and medical observations clearly demonstrate the success of the proposed method. 展开更多
关键词 Techno-physical Toothbrushing Oral Hygiene Education Dental Technology Plaque analysis
下载PDF
The analysis of frequency-dependent characteristics for fluid detection: a physical model experiment 被引量:2
4
作者 陈双全 李向阳 王尚旭 《Applied Geophysics》 SCIE CSCD 2012年第2期195-206,235,236,共14页
According to the Chapman multi-scale rock physical model, the seismic response characteristics vary for different fluid-saturated reservoirs. For class I AVO reservoirs and gas-saturation, the seismic response is a hi... According to the Chapman multi-scale rock physical model, the seismic response characteristics vary for different fluid-saturated reservoirs. For class I AVO reservoirs and gas-saturation, the seismic response is a high-frequency bright spot as the amplitude energy shifts. However, it is a low-frequency shadow for the Class III AVO reservoirs saturated with hydrocarbons. In this paper, we verified the high-frequency bright spot results of Chapman for the Class I AVO response using the frequency-dependent analysis of a physical model dataset. The physical model is designed as inter-bedded thin sand and shale based on real field geology parameters. We observed two datasets using fixed offset and 2D geometry with different fluid- saturated conditions. Spectral and time-frequency analyses methods are applied to the seismic datasets to describe the response characteristics for gas-, water-, and oil-saturation. The results of physical model dataset processing and analysis indicate that reflection wave tuning and fluid-related dispersion are the main seismic response characteristic mechanisms. Additionally, the gas saturation model can be distinguished from water and oil saturation for Class I AVO utilizing the frequency-dependent abnormal characteristic. The frequency-dependent characteristic analysis of the physical model dataset verified the different spectral response characteristics corresponding to the different fluid-saturated models. Therefore, by careful analysis of real field seismic data, we can obtain the abnormal spectral characteristics induced by the fluid variation and implement fluid detection using seismic data directly. 展开更多
关键词 Frequency-dependent characteristic fluid detection time-frequency analysis attenuation and dispersion physical model
下载PDF
The Immuno-fluorescence Quantity Analysis of α-Tubulin and γ-Tubulin Protein in Precancerous Lesion and Carcinoma of the Breast and Its Significance 被引量:1
5
作者 牛昀 张彤文 +3 位作者 王颖 韦丽 魏锡胤 牛瑞芳 《Chinese Journal of Clinical Oncology》 CSCD 2008年第1期16-21,共6页
OBJECTIVE To investigate the changes and values of the expression of α-tubulin and γ-tubulin in atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) of the bre... OBJECTIVE To investigate the changes and values of the expression of α-tubulin and γ-tubulin in atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) of the breast. The relationship between centrosome abnormalities and breast tumor development was further discussed. METHODS There were three groups including ADH, DCIS and IDC with 30 cases in each group. They were analyzed by immuno-fiuorescence quantity analysis. The expression levels of α-tubulin and γ-tubulin protein in these tissues were detected by flow cytometry immuno-fiuorescence analysis and compared with the results from normal tissues. Immunohistochemistry was also performed in this research. RESULTS The results showed significant differences of the average of the positive (FITC labeled) cells (P=0.000) among the four groups. The level of the IDC group was the highest, while normal breast tissue showed the lowest level. The results suggested that the expression levels of α-tubulin and γ-tubulin both increased as the grade of cellular proliferation and differentiation increased. The expressions showed significant differences among all the groups, except between the ADH and DCIS. There were no significant differences between α-tubulin and γ-tubulin expression in each group (P〈0.05), as there was agreement in the immuno-fluorescence and immunohistochemical analysis for protein expression. CONCLUSION There is abnormal expression of centrosome tubulin as an early event in the development of breast tumor. Furthermore these aberrations may play a key role during oncogenesis and promote cellular transformation to malignancy. The immuno-fiuorescence quantitive analysis and immunohistochemistry can complement each other. 展开更多
关键词 centrosome α-tubulin protein centrosome γ-tubulin protein precancerous lesion breast carcinoma immuno-fluorescence quantity analysis.
下载PDF
Cyber Resilience through Real-Time Threat Analysis in Information Security
6
作者 Aparna Gadhi Ragha Madhavi Gondu +1 位作者 Hitendra Chaudhary Olatunde Abiona 《International Journal of Communications, Network and System Sciences》 2024年第4期51-67,共17页
This paper examines how cybersecurity is developing and how it relates to more conventional information security. Although information security and cyber security are sometimes used synonymously, this study contends t... This paper examines how cybersecurity is developing and how it relates to more conventional information security. Although information security and cyber security are sometimes used synonymously, this study contends that they are not the same. The concept of cyber security is explored, which goes beyond protecting information resources to include a wider variety of assets, including people [1]. Protecting information assets is the main goal of traditional information security, with consideration to the human element and how people fit into the security process. On the other hand, cyber security adds a new level of complexity, as people might unintentionally contribute to or become targets of cyberattacks. This aspect presents moral questions since it is becoming more widely accepted that society has a duty to protect weaker members of society, including children [1]. The study emphasizes how important cyber security is on a larger scale, with many countries creating plans and laws to counteract cyberattacks. Nevertheless, a lot of these sources frequently neglect to define the differences or the relationship between information security and cyber security [1]. The paper focus on differentiating between cybersecurity and information security on a larger scale. The study also highlights other areas of cybersecurity which includes defending people, social norms, and vital infrastructure from threats that arise from online in addition to information and technology protection. It contends that ethical issues and the human factor are becoming more and more important in protecting assets in the digital age, and that cyber security is a paradigm shift in this regard [1]. 展开更多
关键词 Cybersecurity Information Security Network Security Cyber Resilience Real-Time Threat analysis Cyber Threats Cyberattacks Threat Intelligence Machine Learning Artificial Intelligence Threat Detection Threat Mitigation Risk Assessment Vulnerability Management Incident Response Security Orchestration Automation Threat Landscape Cyber-physical Systems Critical Infrastructure Data Protection Privacy Compliance Regulations Policy Ethics CYBERCRIME Threat Actors Threat Modeling Security Architecture
下载PDF
Physical analysis on improving the recovery accuracy of the Earth's gravity field by a combination of satellite observations in along-track and cross-track directions 被引量:4
7
作者 郑伟 许厚泽 +1 位作者 钟敏 员美娟 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第10期633-640,共8页
The physical investigations on the accuracy improvement to the measurement of the Earth's gravity field recovery are carried out based on the next-generation Pendulum-A/B out-of-plane twin-satellite formation in this... The physical investigations on the accuracy improvement to the measurement of the Earth's gravity field recovery are carried out based on the next-generation Pendulum-A/B out-of-plane twin-satellite formation in this paper. Firstly, the Earth's gravity field complete up to degree and order 100 is, respectively, recovered by the collinear and pendulum satellite formations using the orbital parameters of the satellite and the matching accuracies of key payloads from the twin GRACE satellites. The research results show that the accuracy of the Earth's gravity field model from the Pendulum-A/B satellite formation is about two times higher than from the collinear satellite formation, and the further improvement of the determination accuracy of the Earth's gravity field model is feasible by the next-generation Pendulum-A/B out-of-plane twin-satellite formation. Secondly, the Earth's gravity field from Pendulum-A/B complete up to degree and order 100 is accurately recovered based on the orbital parameters of the satellite (e.g., an orbital altitude of 400 km, an intersatellite range of 100 km, an orbital inclination of 89° and an orbital eccentricity of 0.001), the matching accuracies of space- borne instruments (e.g. 10-6 m in the intersatellite range, 10-3 m in the orbital position, 10-6 m/s in orbital velocity, and 10-11 m/s2 in non-conservative force), an observation time of 30 days and a sampling interval of 10 s. The measurement accuracy of the Earth's gravity field from the next-generation Pendulum-A/B out-of-plane twin-satellite formation is full of promise for being improved by about l0 times compared with that from the current GRACE satellite formation. Finally, the physical requirements for the next-generation Pendulum-A/B out-of-plane twin-satellite formation are analyzed, and it is proposed that the satellite orbital altitude be preferably designed to be close to 400±50 km and the matching precision of key sensors from the Pendulum-A/B mission be about one order of magnitude higher than from the GRACE program. 展开更多
关键词 twin pendulum-MB satellites collinear and pendulum satellite formations along-cross-track ob-servations physical analysis satellite gravity recovery
下载PDF
Intelligent direct analysis of physical and mechanical parameters of tunnel surrounding rock based on adaptive immunity algorithm and BP neural network 被引量:3
8
作者 Xiao-rui Wang1,2, Yuan-han Wang1, Xiao-feng Jia31.School of Civil Engineering and Mechanics,Huazhong University of Science and Technology, Wuhan 430074,China 2.Department of Civil Engineering,Nanyang Institute of Technology,Nanyang 473004,China 3.Department of Chemistry and Bioengineering,Nanyang Institute of Technology,Nanyang 473004,China. 《Journal of Pharmaceutical Analysis》 SCIE CAS 2009年第1期22-30,共9页
Because of complexity and non-predictability of the tunnel surrounding rock, the problem with the determination of the physical and mechanical parameters of the surrounding rock has become a main obstacle to theoretic... Because of complexity and non-predictability of the tunnel surrounding rock, the problem with the determination of the physical and mechanical parameters of the surrounding rock has become a main obstacle to theoretical research and numerical analysis in tunnel engineering. During design, it is a frequent practice, therefore, to give recommended values by analog based on experience. It is a key point in current research to make use of the displacement back analytic method to comparatively accurately determine the parameters of the surrounding rock whereas artificial intelligence possesses an exceptionally strong capability of identifying, expressing and coping with such complex non-linear relationships. The parameters can be verified by searching the optimal network structure, using back analysis on measured data to search optimal parameters and performing direct computation of the obtained results. In the current paper, the direct analysis is performed with the biological emulation system and the software of Fast Lagrangian Analysis of Continua (FLAC3D. The high non-linearity, network reasoning and coupling ability of the neural network are employed. The output vector required of the training of the neural network is obtained with the numerical analysis software. And the overall space search is conducted by employing the Adaptive Immunity Algorithm. As a result, we are able to avoid the shortcoming that multiple parameters and optimized parameters are easy to fall into a local extremum. At the same time, the computing speed and efficiency are increased as well. Further, in the paper satisfactory conclusions are arrived at through the intelligent direct-back analysis on the monitored and measured data at the Erdaoya tunneling project. The results show that the physical and mechanical parameters obtained by the intelligent direct-back analysis proposed in the current paper have effectively improved the recommended values in the original prospecting data. This is of practical significance to the appraisal of stability and informationization design of the surrounding rock. 展开更多
关键词 adaptive immunity algorithm BP neural network physical and mechanical parameters surrounding rock direct-back analysis
下载PDF
Physical restraint in mental health nursing: A concept analysis 被引量:8
9
作者 Junrong Ye Chen Wang +6 位作者 Aixiang Xiao Zhichun Xia Lin Yu Jiankui Lin Yao Liao Yu Xu Yunlei Zhang 《International Journal of Nursing Sciences》 CSCD 2019年第3期343-348,共6页
Objective: Physical restraint is frequently used in medical services,such as in mental health settings,intensive care units and nursing homes,but its nature varies in different institutions.By reviewing related litera... Objective: Physical restraint is frequently used in medical services,such as in mental health settings,intensive care units and nursing homes,but its nature varies in different institutions.By reviewing related literature,this study aims to clarify the concept of physical restraint in mental health nursing.Method: Three databases (PubMed,PsyclNFO and CINAHL) were retrieved,and Walker and Avant's concept analysis method was used to analyze the concept of physical restraint in mental health nursing.Results: Physical restraint is a coercive approach that enables the administration of necessary treatment by safely reducing the patient's physical movement.It should be the last option used by qualified personnel.Antecedents of physical restraint are improper behavior (violence and disturbance) of patients,medical assessment prior to implementation and legislation governing clinical usage.Consequences of physical restraint are alleviation of conflict,physical injury,mental trauma and invisible impact on the institution.Discussion: This study defined the characteristics of physical restraint in mental health nursing.The proposed concept analysis provided theoretical foundation for future studies. 展开更多
关键词 Concept analysis Mental health services physical restraint Qualitative study Walker and Avant's model
下载PDF
A quantitative analysis model of grid cyber physical systems 被引量:6
10
作者 Li Huang Yun Liang +1 位作者 Feng Huang Dayang Wang 《Global Energy Interconnection》 2018年第5期618-626,共9页
Conventional power systems are being developed into grid cyber physical systems(GCPS) with widespread application of communication, computer, and control technologies. In this article, we propose a quantitative analys... Conventional power systems are being developed into grid cyber physical systems(GCPS) with widespread application of communication, computer, and control technologies. In this article, we propose a quantitative analysis method for a GCPS. Based on this, we discuss the relationship between cyberspace and physical space, especially the computational similarity within the GCPS both in undirected and directed bipartite networks. We then propose a model for evaluating the fusion of the three most important factors: information, communication, and security. We then present the concept of the fusion evaluation cubic for the GCPS quantitative analysis model. Through these models, we can determine whether a more realistic state of the GCPS can be found by enhancing the fusion between cyberspace and physical space. Finally, we conclude that the degree of fusion between the two spaces is very important, not only considering the performance of the whole business process, but also considering security. 展开更多
关键词 CYBER physical systems QUANTITATIVE analysis algorithm BIPARTITE network SMART GRID
下载PDF
Application of the Physical Quantity Field Evolution under Numerical Model in Precipitation Forecast of Yantai 被引量:1
11
作者 SUN Dian-guang,HUANG Ben-feng Yantai Meteorological Bureau in Shandong Province,Yantai 264003,China 《Meteorological and Environmental Research》 CAS 2011年第11期1-4,7,共5页
[Objective] The research aimed to understand role of the forecast data about physical quantity field in precipitation forecast.[Method] By contrasting forecast and actual situation of the precipitation in Yantai durin... [Objective] The research aimed to understand role of the forecast data about physical quantity field in precipitation forecast.[Method] By contrasting forecast and actual situation of the precipitation in Yantai during 2-3 July and 12-15 September,2011,advantages and disadvantages of the different numerical forecast models (Japan fax chart,European center,MM5,Grapes and T639) were analyzed.[Result] MICAPS system could provide live situation of the physical quantity field,but couldn't provide the future evolution situation.Japan fax chart,European center,MM5,Grapes and T639 could provide future evolution situation of the physical quantity field.[Conclusion] The contrasts and analyses on forecast situations of the physical quantity fields in many precipitation processes showed that evolutions of the vertical velocity,temperature dew point difference,relative humidity and wind field at the different heights could improve forecast accuracy of the precipitation in Yantai. 展开更多
关键词 Numerical model Evolution of the physical quantity field Application of precipitation forecast China
下载PDF
Engagement in outdoor physical activity under ambient fine particulate matter pollution: A risk-benefit analysis 被引量:1
12
作者 Ruopeng An Hyojung Kang +1 位作者 Lianzhong Cao Xiaoling Xiang 《Journal of Sport and Health Science》 SCIE 2022年第4期537-544,共8页
Background:Outdoor physical activity(PA)brings important health benefits,but exposure to polluted air increases health risks.This study aimed to quantify the tradeoff of PA under fine particulate matter(PM_(2.5))air p... Background:Outdoor physical activity(PA)brings important health benefits,but exposure to polluted air increases health risks.This study aimed to quantify the tradeoff of PA under fine particulate matter(PM_(2.5))air pollution by estimating the optimal PA duration under various pollution levels.Methods:A risk-benefit analysis was performed to estimate the optimal outdoor moderate-intensity PA(MPA)duration under varying PM_(2.5) concentrations.Results:An inverse nonlinear relationship was identified between optimal MPA duration and background PM_(2.5) concentration levels.When background PM_(2.5) concentration increased to 186 μg/m^(3),the optimal outdoor MPA duration decreased to 2.5 h/week,the minimum level recommended by current PA guidelines.When background PM_(2.5) concentration further increased to 235 μg/m^(3),the optimal outdoor MPA duration decreased to 1 h/week.The relationship between optimal MPA duration and background PM_(2.5) concentration levels was stronger when exercising at a location closer to a source of air pollution.Compared to the general adult population,adults aged 60 years and older had substantially steeper curves—the optimal outdoor MPA duration decreased to 2.5 h/week when background PM_(2.5) concentration reached 45 μg/m^(3).Conclusion:The health benefit of outdoor MPA by far outweighs the health risk of PM_(2.5) pollution for the global average urban background concentration(22 μg/m^(3),).This modeling study examined a single type of air pollutant and suffered from measurement errors and estimation uncertainties.Future research should examine other air pollutants and indoor PA,incorporate short-and mid-term health effects of MPA and air pollution into the risk-benefit analysis,and provide estimates specific for high-risk subgroups. 展开更多
关键词 Air pollution EXERCISE physical activity PM_(2.5) Risk-benefit analysis
下载PDF
Recent progress of physical failure analysis of GaN HEMTs 被引量:1
13
作者 Xiaolong Cai Chenglin Du +5 位作者 Zixuan Sun Ran Ye Haijun Liu Yu Zhang Xiangyang Duan and Hai Lu 《Journal of Semiconductors》 EI CAS CSCD 2021年第5期48-59,共12页
Gallium nitride(GaN)-based high-electron mobility transistors(HEMTs) are widely used in high power and high frequency application fields, due to the outstanding physical and chemical properties of the GaN material. Ho... Gallium nitride(GaN)-based high-electron mobility transistors(HEMTs) are widely used in high power and high frequency application fields, due to the outstanding physical and chemical properties of the GaN material. However, GaN HEMTs suffer from degradations and even failures during practical applications, making physical analyses of post-failure devices extremely significant for reliability improvements and further device optimizations. In this paper, common physical characterization techniques for post failure analyses are introduced, several failure mechanisms and corresponding failure phenomena are reviewed and summarized, and finally device optimization methods are discussed. 展开更多
关键词 GAN high electron mobility transistors physical analysis failure mechanism
下载PDF
PHYSICAL VALUE MAPPING ALGORITHM OF MESH IN FINE CAE ANALYSIS OF AUTOMOBILE BODY STRUCTURE 被引量:2
14
作者 Hu Ping Gong Kejia Bao Yidong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2005年第3期338-341,共4页
A physical value mapping (PVM) algorithm based on finite element mesh from the stamped part in stamping process to the product is presented, In order to improve the efficiency of the PVM algorithm, a search way from... A physical value mapping (PVM) algorithm based on finite element mesh from the stamped part in stamping process to the product is presented, In order to improve the efficiency of the PVM algorithm, a search way from the mesh of the product to the mesh of the stamped part will be adopted. At the same time, the search process is divided into two steps: entire search (ES) and local search (LS), which improve the searching efficiency. The searching area is enlarged to avoid missing projection elements in ES process. An arc-length method is introduced in LS process. The validity is confirmed by the results of the complex industry-forming product. 展开更多
关键词 Fine CAE analysis of auto body structure Finite element mesh Arc method physical value mapping
下载PDF
Factor Analysis on Quantity of Discharged Pollutants in Wastewater in Major Cities 被引量:1
15
作者 赵双蕊 《Agricultural Science & Technology》 CAS 2016年第4期964-967,共4页
The research performed statistical analysis on 186 data concerning the amount of discharged industrial wastewater, the amount of oxygen demand of industrial wastewater, the amount of ammonia and nitrogen discharged fr... The research performed statistical analysis on 186 data concerning the amount of discharged industrial wastewater, the amount of oxygen demand of industrial wastewater, the amount of ammonia and nitrogen discharged from industries, the amount of urban discharged domestic sewage, the amount of daily life chemical oxygen demand, and the amount of domestic ammonia and nitrogen to explore source of pollutants from wastewater and guarantee urban water quality.Factor analysis was then performed with SPSS according to discharge quantity of pollutants. The results should that the major pollutants are from domestic sewage it is expected scientific suggestions be proposed on water quality in our country. 展开更多
关键词 quantity of discharged pollutants in wastewater Factor analysis SPSS
下载PDF
Effects of restoration modes on the spatial distribution of soil physical properties after land consolidation: a multifractal analysis
16
作者 KE Zengming LIU Xiaoli +4 位作者 MA Lihui TU Wen FENG Zhe JIAO Feng WANG Zhanli 《Journal of Arid Land》 SCIE CSCD 2021年第12期1201-1214,共14页
Soil physical properties(SPP)are considered to be important indices that reflect soil structure,hydrological conditions and soil quality.It is of substantial interest to study the spatial distribution of SPP owing to ... Soil physical properties(SPP)are considered to be important indices that reflect soil structure,hydrological conditions and soil quality.It is of substantial interest to study the spatial distribution of SPP owing to the high spatial variability caused by land consolidation under various land restoration modes in excavated farmland in the loess hilly area of China.In our study,three land restoration modes were selected including natural restoration land(NR),alfalfa land(AL)and maize land(ML).Soil texture composition,including the contents of clay,silt and sand,field capacity(FC),saturated conductivity(Ks)and bulk density(BD)were determined using a multifractal analysis.SPP were found to possess variable characteristics,although land consolidation destroyed the soil structure and decreased the spatial autocorrelation.Furthermore,SPP varied with land restoration and could be illustrated by the multifractal parameters of D1,ΔD,ΔαandΔf in different modes of land restoration.Owing to multiple compaction from large machinery in the surface soil,soil particles were fine-grained and increased the spatial variability in soil texture composition under all the land restoration modes.Plough numbers and vegetative root characteristics had the most significant impacts on the improvement in SPP,which resulted in the best spatial distribution characteristics of SPP found in ML compared with those in AL and NR.In addition,compared with ML,Δαvalues of NR and AL were 4.9-and 3.0-fold that of FC,respectively,andΔαvalues of NR and AL were 2.3-and 1.5-fold higher than those of Ks,respectively.These results indicate that SPP can be rapidly improved by increasing plough numbers and planting vegetation types after land consolidation.Thus,we conclude that ML is an optimal land restoration mode that results in favorable conditions to rapidly improve SPP. 展开更多
关键词 land consolidation land restoration multifractal analysis spatial distribution soil physical properties
下载PDF
Unleashing the Power of Information Theory: Enhancing Accuracy in Modeling Physical Phenomena 被引量:1
17
作者 Boris Menin 《Journal of Applied Mathematics and Physics》 2023年第3期760-779,共20页
When building a model of a physical phenomenon or process, scientists face an inevitable compromise between the simplicity of the model (qualitative-quantitative set of variables) and its accuracy. For hundreds of yea... When building a model of a physical phenomenon or process, scientists face an inevitable compromise between the simplicity of the model (qualitative-quantitative set of variables) and its accuracy. For hundreds of years, the visual simplicity of a law testified to the genius and depth of the physical thinking of the scientist who proposed it. Currently, the desire for a deeper physical understanding of the surrounding world and newly discovered physical phenomena motivates researchers to increase the number of variables considered in a model. This direction leads to an increased probability of choosing an inaccurate or even erroneous model. This study describes a method for estimating the limit of measurement accuracy, taking into account the stage of model building in terms of storage, transmission, processing and use of information by the observer. This limit, due to the finite amount of information stored in the model, allows you to select the optimal number of variables for the best reproduction of the observed object and calculate the exact values of the threshold discrepancy between the model and the phenomenon under study in measurement theory. We consider two examples: measurement of the speed of sound and measurement of physical constants. 展开更多
关键词 Finite Information quantity International System of Units MODELLING physical Constant Speed of Sound
下载PDF
Threshold Analysis of Sounding Physical Quantities of Rainstorm in Southwest China
18
作者 Tianhong GU Yang GOU Wenyu ZHOU 《Meteorological and Environmental Research》 CAS 2021年第4期28-31,共4页
Using physical quantities calculated by 16 radiosonde stations of Southwest China during 2010-2015,nine kinds of physical quantities with certain representational significance in water vapor,thermal and dynamic condit... Using physical quantities calculated by 16 radiosonde stations of Southwest China during 2010-2015,nine kinds of physical quantities with certain representational significance in water vapor,thermal and dynamic conditions were selected.Via box-plot,statistical analysis was conducted,and thresholds of sounding physical quantities of rainstorm in Southwest China were obtained,which could provide certain reference for further improving the rainstorm forecast in Southwest China. 展开更多
关键词 Sounding physical quantity THRESHOLD Box-plot RAINSTORM
下载PDF
医学科技期刊物理量(physical quantity)与缩写
19
《中国医药指南》 2009年第1期146-146,共1页
用于定量地扫描物理现象的量.即科学技术领域里使用的表示长度、质量、时间、电流、热力学温度、物质的量和发光强度的量。使用的单位应是法定计量单位。两分钟→2min,一秒钟→1 s,三小时→3h,4天→4d,1国际单位用IU。国际代号不用于无... 用于定量地扫描物理现象的量.即科学技术领域里使用的表示长度、质量、时间、电流、热力学温度、物质的量和发光强度的量。使用的单位应是法定计量单位。两分钟→2min,一秒钟→1 s,三小时→3h,4天→4d,1国际单位用IU。国际代号不用于无数字的文句中,如每天不能用每d,但每天10mg应写为10mg/d,次/秒→次/s。 展开更多
关键词 科技期刊 缩写 构词法 physical quantity 物理量 医学 现代医药学
下载PDF
Geospatial Analysis of Flood Vulnerability Levels Based on Physical Characteristics and Resilience Capacity of Peri-Urban Settlements in Nigeria
20
作者 Omobolaji Oluwamuyiwa Afolabi Victoria Ojone Emelu +5 位作者 Elekwachi Wali Maureen Chidinma Orji Lilian Chidinma Bosco-Abiahu Olushola Idowu Tonye Yemi-Jonathan Odinaka Amadi Wali Sunny Oghenefegor Asomaku 《Journal of Geoscience and Environment Protection》 2022年第8期267-288,共22页
Flooding is becoming a yearly reoccurring event in many communities and cities in Nigeria, leading to the destruction of properties and deaths;hence, we must take measures to either prepare for the impact or curb the ... Flooding is becoming a yearly reoccurring event in many communities and cities in Nigeria, leading to the destruction of properties and deaths;hence, we must take measures to either prepare for the impact or curb the occurrence. The study identified flood vulnerability levels of communities in Isoko North LGA based on physical environmental domains such as land use, elevation, and proximity to river channel (drainage) using geospatial techniques. Also, attributes that could contribute to the resilience capacity building of the communities were assessed. From the study, 73.93% of the entire area is moderately and highly vulnerable to flood, while among the communities, seventeen (17) are categorized as moderately vulnerable, and four (4) are lowly vulnerable. The overall resilience capacity of the communities indicated can build a substantial capacity towards community resilience (3.02, 0.06). However, there is a need to encourage collaboration with stakeholders to improve mitigation action and enhance various shortcomings toward resilience capacity building. 展开更多
关键词 Community Resilience Flood Vulnerability Geospatial analysis physical Environment Resilience Capacity
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部