期刊文献+
共找到1,818篇文章
< 1 2 91 >
每页显示 20 50 100
Research surveys and their evolution:Past,current and future uses in healthcare
1
作者 Michael Colwill Richard Pollok Andrew Poullis 《World Journal of Methodology》 2024年第4期91-95,共5页
Research surveys are believed to have originated in antiquity with evidence of them being performed in ancient Egypt and Greece.In the past century,their use has grown significantly and they are now one of the most fr... Research surveys are believed to have originated in antiquity with evidence of them being performed in ancient Egypt and Greece.In the past century,their use has grown significantly and they are now one of the most frequently employed research methods including in the field of healthcare.Modern validation techniques and processes have allowed researchers to broaden the scope of qualitative data they can gather through these surveys such as an individual’s views on service quality to nationwide surveys that are undertaken regularly to follow healthcare trends.This article focuses on the evolution and current utility of research surveys,different methodologies employed in their creation,the advantages and disadvantages of different forms and their future use in healthcare research.We also review the role artificial intelligence and the importance of increased patient participation in the development of these surveys in order to obtain more accurate and clinically relevant data. 展开更多
关键词 Research surveys METHODOLOGY Sampling Artificial intelligence
下载PDF
Dietary Surveys Carried out among Diabetic Patients Hospitalized in the Metabolic and Endocrine Diseases Department of the C.H.U-B
2
作者 Lewis Raud Miamb Bertin Mikolo +2 位作者 Melyna Aïcha Ntsan Bonaventure Max Lazare Peneme Arnaud Wilfrid Etou Ossibi 《Journal of Biosciences and Medicines》 2024年第10期361-372,共12页
A varied and balanced diet has always been essential in the optimal management of diabetes. The objective of this work was to evaluate dietary surveys among 50 diabetic patients hospitalized in the metabolic and endoc... A varied and balanced diet has always been essential in the optimal management of diabetes. The objective of this work was to evaluate dietary surveys among 50 diabetic patients hospitalized in the metabolic and endocrine diseases department of the Brazzaville Hospital and University Center. This survey was carried out using two methods: dietary history and 24-hour recall. The results relating to the dietary history revealed in the patients a dietary imbalance characterized by snacking at meals, non-compliance with a balanced diet and a high frequency of consumption of foods rich in simple sugar. and saturated fats. Regarding the 24-hour recall, the survey showed that the average blood sugar levels of hospitalized patients increased depending on the number of meals. This meant that these hyperglycemias (2 to 5 g/L) observed in these patients exceeded three meals per day and required, among other things, an increase in insulin intake or doses. The age groups of diabetic patients were also divided. These age groups had partly defined the types of diabetes encountered. Regarding body mass index, women had a body mass index greater than 30 kg/m2 compared to men. This increase in body mass index was explained by being overweight or even obese due to excess body fat. 展开更多
关键词 Diabetes Dietary Survey Dietary History 24-Hour Recall
下载PDF
Are the altitudinal patterns of plant diversity derived from field surveys consistent with those from empirical integrated methods?
3
作者 ZHAN Qing-hua FU Zhi-hao +2 位作者 ZHOU Ya-dong YAN Xue WANG Qing-feng 《Journal of Mountain Science》 SCIE CSCD 2023年第5期1307-1315,共9页
Field surveys and empirical integrated methods are commonly used in the ecological research to understand the altitudinal pattern of plant diversity of mountains.However,few studies have compared the differences betwe... Field surveys and empirical integrated methods are commonly used in the ecological research to understand the altitudinal pattern of plant diversity of mountains.However,few studies have compared the differences between the two methods on the same scale.Here,we addressed and compared the altitudinal patterns of species richness(SR),phylogenetic diversity(PD),the standardized effect size of phylogenetic diversity(PDses)and mean phylogenetic distance(MPDses)of about 580 angiosperms growing on Mount Kenya from two independent datasets:one is based on our several times field surveys in this mountain and another one is based on empirical data integrated from literatures.We found that the altitudinal diversity patterns of field surveys dataset were consistent with the empirical integrated dataset.Both SR and PD showed hump-shaped patterns along the altitude,and both PDses and MPDses showed monotonically decreasing patterns along the altitude.The ratio of diversity between field surveys dataset and empirical integrated dataset were gradually increase along the altitude.Our research provides new insight for understanding the altitudinal diversity patterns of plants of a tropical mountain. 展开更多
关键词 Mount Kenya AFRICA surveys Interpolation method TAXONOMIC PHYLOGENETIC
下载PDF
Insync Surveys图书馆用户满意度调查分析 被引量:8
4
作者 张为杰 杨广锋 周婕 《图书情报知识》 CSSCI 北大核心 2009年第6期34-38,86,共6页
Insync Surveys,原名Ambit Insights/Rodski Survey Research,是澳大利亚一家调查服务公司。其用户满意度调查自1998年在墨尔本大学图书馆实施以来,影响不断扩大,并与CAUL建立了稳定的合作关系。Insync Surveys以关注度-满意度为方法基... Insync Surveys,原名Ambit Insights/Rodski Survey Research,是澳大利亚一家调查服务公司。其用户满意度调查自1998年在墨尔本大学图书馆实施以来,影响不断扩大,并与CAUL建立了稳定的合作关系。Insync Surveys以关注度-满意度为方法基础,指标体系灵活调整,并提供基本调查和全面调查两种服务模式,取得了良好的实践效果。 展开更多
关键词 Insync surveys Rodski 满意度调查 服务质量评估
下载PDF
Analysis of the Results of Two Nationwide Surveys on Clonorchis sinensis Infection in China 被引量:24
5
作者 CHEN Ying Dan ZHOU Chang Hai XU Long Qi 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2012年第2期163-166,共4页
Objective To examine Clonorchis sinensis infection in China and evaluate the effectiveness of efforts to prevent and control it,two nationwide surveys were undertaken in 31 provinces,autonomous regions,and municipalit... Objective To examine Clonorchis sinensis infection in China and evaluate the effectiveness of efforts to prevent and control it,two nationwide surveys were undertaken in 31 provinces,autonomous regions,and municipalities(PAMs) during 1988-92(the 1990 survey) and during 2001-04(the 2003 survey).Methods During the period 2001-04,two sampling methods were applied.The first method repeated the stratified cluster random sampling used in the 1990 survey;the second method applied two-characteristic stratified cluster random sampling in 27 PAMs—the 2003 endemic area(EA) survey.The Kato-Katz thick smear method was used for the nationwide survey.Results The infection rates of Clonorchis sinensis in the 1990 and 2003 surveys were 0.311% and 0.579%,respectively.The infection rate was 2.40% in the 2003 EA survey,and it was estimated that 12.49 million people in China were infected with Clonorchis sinensis.Conclusion The 2003 survey showed that the standardized infection rate of Clonorchis sinensis increased by 74.85% compared with the 1990 survey.The infection rate in males was higher than in females;the infection rate among people eating raw fish or eating out frequently was higher than among those who did not. 展开更多
关键词 Clonorchis sinensis Two nationwide surveys The status of infection in China
下载PDF
Taxonomy is the cornerstone of biodiversity conservation SEABRI reports on biological surveys in Southeast Asia 被引量:3
6
作者 Shu-Qiang Li Rui-Chang Quan 《Zoological Research》 CAS CSCD 2017年第5期213-213,共1页
The Southeast Asia Biodiversity Research Institute (SEABRI) is an international scientific research and education organization affiliated directly to the Chinese Academy of Sciences (CAS) and managed by the Xishua... The Southeast Asia Biodiversity Research Institute (SEABRI) is an international scientific research and education organization affiliated directly to the Chinese Academy of Sciences (CAS) and managed by the Xishuangbanna Tropical Botanical Garden (XTBG). By harnessing its connections with all CAS institutes, local institutes and international agencies and leveraging on their resources, it seeks to make a significant contribution to biodiversity conservation in Southeast Asia. 展开更多
关键词 In SEABRI reports on biological surveys in Southeast Asia Taxonomy is the cornerstone of biodiversity conservation
下载PDF
Research Surveys of Electrochemical Sensors for in-situ Determining Hydrogen in Steels 被引量:1
7
作者 Gang YU, Xueyuan ZHANG and Yuanlong DU (State Key Laboratory for Corrosion and Protection, Institute of Corrosion and Protection of Metals, Chinese Academy of Sciences, Shenyang 110015, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第3期305-310,共6页
The principle, construction and application of two types of electrochemical sensors-amperometric and potentiometric are surveyed. Both types of sensors are very sensitive to changes in temperature. The accuracy of hyd... The principle, construction and application of two types of electrochemical sensors-amperometric and potentiometric are surveyed. Both types of sensors are very sensitive to changes in temperature. The accuracy of hydrogen measurement depends on both the precision of sensors developed and the reliable technique of installation and security of sensors. The two types of sensors have been used for in-situ determining hydrogen permeated in steels owing to a corrosive reaction, a hydrogen gas circumstance at elevated temperatures and high pressure or also a pretreatment process such as pickling and plating process, etc. 展开更多
关键词 Research surveys of Electrochemical Sensors for in-situ Determining Hydrogen in Steels NIO
下载PDF
Integrated geophysical surveys on railroads in permafrost areas
8
作者 A.Ivanov S.Klepikova +2 位作者 M.Shirobokov A.Urusova A.Savin 《Research in Cold and Arid Regions》 CSCD 2013年第5期582-586,共5页
The zones of thawed ground in the permafrost area are most dangerous from engineer-geologist effect point of view. Detection of such zones, as making forecast of their movement is the main task of engineer-geologist s... The zones of thawed ground in the permafrost area are most dangerous from engineer-geologist effect point of view. Detection of such zones, as making forecast of their movement is the main task of engineer-geologist survey been held in railway industry. This paper presents general issues concerning railway construction and operation in permafrost areas. Comprehensive geophysical methods to monitor the development of thawed soils axe considered in detail. The main physical parameters which help define permafrost and thawed soil patches are described. Author of current paper pointed out main factors, allowing predicting potential areas of development of thawed grounds. They offered set non-destructive methods: GPR investigations, seismic survey and elec- tric exploration. Whole sets of geophysical data: electric resistivity, velocity of S-wave and P-wave (and their correlation), allow us with high confidence specify characteristics and state of soil either under the line of road, or near it. At the same time the meth- od allows to predict direction of further development of thawed ground area. 展开更多
关键词 geophysical surveys on railroads ground-penetrating radar geoelectric sounding seismic refraction survey perma- frost thawed soils
下载PDF
Toward Estimating the Variance in Acoustic Surveys Based on Sampling Design
9
作者 Magnar Aksland 《Open Journal of Marine Science》 2011年第1期1-17,共17页
This paper develops a sampling method to estimate the integral of a function of the area with a strategy to cover the area with parallel lines of observation. This sampling strategy is special in that lines very close... This paper develops a sampling method to estimate the integral of a function of the area with a strategy to cover the area with parallel lines of observation. This sampling strategy is special in that lines very close to each other are selected much more seldom than under a uniformly random design for the positions of the parallel lines. It is also special in that the positions of some of the lines are deterministic. Two different variance estimators are derived and investigated by sampling different man made signal functions. They show different properties in that the estimator that estimate the biggest variance gives an error interval that, in some situations, may be more than ten times the error interval computed from the other estimator. It is also obvious that the second estimator underestimates the variance. The author has not succeeded to derive an expression for the expectation of this estimator. This work is motivated towards finding the variance of acoustic abundance estimates. 展开更多
关键词 ACOUSTIC ABUNDANCE ESTIMATION LINE surveys Sampling Design Sampling in the Area Variance ESTIMATION
下载PDF
Color-Redshift Relations and Photometric Redshift Estimations of Quasars in Large Sky Surveys
10
作者 Xue-BingWu WeiZhang XuZhou 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2004年第1期17-27,共11页
With a recently constructed composite quasar spectrum and the χ<SUP>2</SUP> minimization technique, we describe a general method for estimating the photometric redshifts of a large sample of quasars by de... With a recently constructed composite quasar spectrum and the χ<SUP>2</SUP> minimization technique, we describe a general method for estimating the photometric redshifts of a large sample of quasars by deriving theoretical color-redshift relations and comparing the theoretical colors with the observed ones. We estimated the photometric redshifts from the 5-band SDSS photometric data of 18678 quasars in the first major data release of SDSS and compared them with their spectroscopic redshifts. The difference is less than 0.1 for 47 % of the quasars and less than 0.2 for 68 %. Based on the calculation of the theoretical color-color diagrams of stars, galaxies and quasars both on the SDSS system and on the BATC system, we expect that we would be able to select candidates of high redshift quasars more efficaciously with the latter than with the former, provided the BATC survey can detect objects with magnitudes fainter than 21. 展开更多
关键词 galaxies: photometry quasars: general quasars: emission lines surveys
下载PDF
Vocal behavior of Crested Guineafowl(Guttera edouardi) based on visual and sound playback surveys in the Umhlanga Lagoon Nature Reserve,Kwa Zulu-Natal province,South Africa
11
作者 Johann H.van Niekerk 《Chinese Birds》 CSCD 2015年第3期132-139,共8页
Background:Generally speaking,playbacks were often ineffective to determine the group sizes of birds since mainly males from leks responded.This limitation has not been tested properly for flocking birds such as Crest... Background:Generally speaking,playbacks were often ineffective to determine the group sizes of birds since mainly males from leks responded.This limitation has not been tested properly for flocking birds such as Crested Guineafowl(Guttera edouardi) with the view to use it as a counting method.The aims of the study reported in this paper were(1) to describe the cal s of Crested Guineafowl in a social context;(2) to interpret cal s in an evolutionary context;and(3) to demonstrate that playbacks can be used to locate and count Crested Guineafowl in smal isolated forests.Methods:The vocal behavior of Crested Guineafowl was observed during a survey conducted in the Umhlanga Lagoon Nature Reserve(Kwa Zulu-Natal,South Africa) from November 2010 to June 2012.Transect line observations and sound playback methods were used.Results:The behavioral context and structure of cal s were described.The eight cal s described for Crested Guineafowl were produced mainly to unite flock members in the dense understory,where visibility was poor,and to repel intruders.When not disturbed,Crested Guineafowl were quiet and only made soft contact calls.Conclusions:The high rate of call back and the fact that flocks invariably approach the source of the call en masse,shows that field researchers are able to assess the population size of Crested Guineafowl with sound playbacks along a transect.The value of playbacks as a conservation tool is assessed. 展开更多
关键词 Guttera edouardi PLAYBACK CALLS Social behavior FLOCKING TRANSECT surveys
下载PDF
Discussions about Magic Weapon of CPC's Work Based on Study of Mao Zedong's Rural Surveys
12
作者 Xiaoting MENG Peng YANG 《Asian Agricultural Research》 2018年第4期103-106,共4页
Former chairman Mao Zedong conducted extensive rural surveys during the exploration of the Chinese revolutionary road. In 1941,in order to change the state of the party's theory separating from reality,Mao Zedong ... Former chairman Mao Zedong conducted extensive rural surveys during the exploration of the Chinese revolutionary road. In 1941,in order to change the state of the party's theory separating from reality,Mao Zedong organized and published the book Rural Surveys,which provided the direction for survey and research of the party members. The survey and research are excellent tradition and style of work of the party,and also a major weapon for outstanding achievements in China's revolution and construction. Socialism with Chinese characteristics has entered a new era. Studying the Rural Surveys has important practical value for beating off the new challenges in the issues concerning agriculture,farmers,and rural areas. 展开更多
关键词 SURVEY Mao Zedong Rural surveys Magic weapon
下载PDF
Shallow Reflection Surveys of the East Ongul Island, the Lützow-Holm Complex, East Antarctica
13
作者 Masaki Kanao Tetsuya Takemoto +2 位作者 Akira Fujiwara Kiyoshi Ito Takeshi Ikawa 《International Journal of Geosciences》 2014年第9期1037-1047,共11页
The shallow reflection surveys were carried out in 2007 and 2010 austral summers in East Ongul Island, the Lützow-Holm Complex (LHC), East Antarctica. LHC is identified by geologically as one of the Pan-African t... The shallow reflection surveys were carried out in 2007 and 2010 austral summers in East Ongul Island, the Lützow-Holm Complex (LHC), East Antarctica. LHC is identified by geologically as one of the Pan-African terrains of Eastern Dronning Maud Land. The multi-channel reflection surveys targeted to achieve the image of laminated layering of metamorphic rocks near the surface (the depths down to a few hundreds of meters) of the crystalline crust. Two surveys were conducted in total length of the profiles about 500 m along a main traffic load across the East Ongul Island. The multi-channel acquisition systems were utilized with combining the dense geophones along the profiles. Seismic sources were adopted by combining the boom of a power shovel, a weight drop and hammer shots with their intervals in a few tens of meters. The obtained data include clear first P-arrivals in far offset distance. The energy of P-S converted waves was enhanced because of the characteristics of the seismic sources. Pre-stacked images could be expected to the information on metamorphic layering for several lithological structure composed by hornblende gneiss, garnet gneiss and pyroxene gneiss appearing as the surface bedrocks. The conducted shallow reflection surveys would give rise to one step for understanding tectonic formation of LHC, as one of the Pan-African mobile belts in Gondwana super-continent. 展开更多
关键词 SHALLOW REFLECTION surveys METAMORPHIC LAYERING CRUSTAL Structure Continental Evolution East ANTARCTICA
下载PDF
The Use of Spatial Sampling Designs in Business Surveys
14
作者 Maria Michela Dickson Roberto Benedetti +1 位作者 Diego Giuliani Giuseppe Espa 《Open Journal of Statistics》 2014年第5期345-354,共10页
An innovative use of spatial sampling designs is here presented. Sampling methods which consider spatial locations of statistical units are already used in agricultural and environmental contexts, while they have neve... An innovative use of spatial sampling designs is here presented. Sampling methods which consider spatial locations of statistical units are already used in agricultural and environmental contexts, while they have never been exploited for establishment surveys. However, the rapidly increasing availability of geo- referenced information about business units makes that possible. In business studies, it may indeed be important to take into account the presence of spatial autocorrelation or spatial trends in the variables of interest, in order to have more precise and efficient estimates. The opportunity of using the most innovative spatial sampling designs in business surveys, in order to produce samples that are well spread in space, is here tested by means of Monte Carlo experiments. For all designs, the Horvitz-Thompson estimator of the population total is used both with equal and unequal inclusion probabilities. The efficiency of sampling designs is evaluated in terms of relative RMSE and efficiency gain compared with designs ignoring the spatial information. Furthermore, an evaluation of spatially balancing samples is also conducted. 展开更多
关键词 SPATIAL Sampling DESIGN BUSINESS surveys Horvitz-Thompson ESTIMATOR SPATIAL BALANCE
下载PDF
From Applied to Pure Science: Midwestern Geological Surveys in the 19th Century
15
作者 Michael D. Severs 《History Research》 2012年第2期146-163,共18页
Between 1850 and 1900, state geological surveys in the Midwest underwent an ideological shift by transforming from institutions based on applied science to those based on pure science. Three factors influenced this pr... Between 1850 and 1900, state geological surveys in the Midwest underwent an ideological shift by transforming from institutions based on applied science to those based on pure science. Three factors influenced this process: the acquisition of permanent status from state governments, the establishment of the USGS (United States Geological Survey), and the increase in regional professional scientific societies and publications in the Midwest. These factors aided in the transformation of research projects by state geologists. These projects grew more focused, of higher quality, and increased in number during this time-period. State governments still expected Midwestern geological surveys to meet the practical needs of their respective states as this transformation continued, but surveys complemented these goals with projects more closely related to pure science. This shift encouraged the research goals of surveys to investigate projects more closely related to pure scientific pursuits, and significantly aided in the growth of the earth sciences in the nineteenth Century and early twentieth Century. 展开更多
关键词 Midwestern Geological surveys Pure and Applied Science Nineteenth Century Scientific Institutions History of American Science
下载PDF
Chen Yun's Rural Surveys in China
16
作者 Yurong QUAN Peng YANG 《Asian Agricultural Research》 2022年第2期17-22,共6页
In order to explore a way to completely transform China,the Chinese Communists have vigorously promoted the style of investigations and research in rural areas.Chen Yun is a model of this rural investigation movement.... In order to explore a way to completely transform China,the Chinese Communists have vigorously promoted the style of investigations and research in rural areas.Chen Yun is a model of this rural investigation movement.He focused on understanding the life of the peasant class and the reality of China's rural areas through field investigations.The survey content was meticulous and extensive,and the survey process sought truth from facts.He creatively used a variety of survey methods based on objective conditions,and strove to earnestly benefit the people.Chen Yun provided Marxist guiding ideology for rural investigations in China,guided rural investigations to proceed on the right track,and at the same time infused rural investigations with the value concept of putting the people first,which still has important reference significance for solving the problems of agriculture,rural areas and farmers in the new situation. 展开更多
关键词 Chen Yun Rural surveys Seeking truth from facts
下载PDF
Fuzzy Geometric Programming in Multivariate Stratified Sample Surveys in Presence of Non-Response with Quadratic Cost Function
17
作者 Shafiullah   Mohammad Faisal Khan Irfan Ali 《American Journal of Operations Research》 2014年第3期173-188,共16页
In this paper, the problem of non-response with significant travel costs in multivariate stratified sample surveys has been formulated of as a Multi-Objective Geometric Programming Problem (MOGPP). The fuzzy programmi... In this paper, the problem of non-response with significant travel costs in multivariate stratified sample surveys has been formulated of as a Multi-Objective Geometric Programming Problem (MOGPP). The fuzzy programming approach has been described for solving the formulated MOGPP. The formulated MOGPP has been solved with the help of LINGO Software and the dual solution is obtained. The optimum allocations of sample sizes of respondents and non respondents are obtained with the help of dual solutions and primal-dual relationship theorem. A numerical example is given to illustrate the procedure. 展开更多
关键词 Geometric PROGRAMMING FUZZY PROGRAMMING NON-RESPONSE with Travel Cost Optimum ALLOCATIONS MULTIVARIATE STRATIFIED Sample surveys
下载PDF
Wide-bandwidth drift-scan pulsar surveys of globular clusters:application to early science observations with FAST
18
作者 Lei Zhang George Hobbs +7 位作者 Di Li Duncan Lorimer Jie Zhang Meng Yu You-Ling Yue Pei Wang Zhi-Chen Pan Shi Dai 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第10期11-20,共10页
The Five-hundred-meter Aperture Spherical Telescope (FAST) will begin its early-science oper- ations during 2016. Drift-scan pulsar surveys will be carried out during this period using an ultra-wide-band receiver sy... The Five-hundred-meter Aperture Spherical Telescope (FAST) will begin its early-science oper- ations during 2016. Drift-scan pulsar surveys will be carried out during this period using an ultra-wide-band receiver system (covering - 270 to 1620 MHz). We describe a method for accounting for the changes in the telescope beam shape and the pulsar parameters when searching for pulsars over such a wide bandwidth. We applied this method to simulated data sets of pulsars in globular clusters that are visible to FAST and found that a representative observation would have a sensitivity of -40 ply. Our results showed that a sin- gle drift-scan (lasting less than a minute) is likely to find at least one pulsar for observations of four globular clusters. Repeated observations will increase the likely number of detections. We found that pulsars in - 16 clusters are likely to be found if the data from 100 drift-scan observations of each cluster are incoherently combined. 展开更多
关键词 pulsars -- drift-scan pulsar surveys -- globular clusters
下载PDF
Sanitary Surveys and Hydrochemistry of Groundwater in Two Urban Towns (Ado-Ekiti and Ijero-Ekiti), Southwestern Nigeria
19
作者 Abel Ojo Talabi Lekan Olatayo Afolagboye +1 位作者 Christopher Ayodele Ajayi Olufunke Kolawole 《Journal of Geoscience and Environment Protection》 2022年第7期159-185,共27页
Groundwater contamination in urban cities is imminent in the phase of increased anthropogenic activities apart from the contribution of geogenic contaminants. This study examined the sanitary surveys and hydrochemistr... Groundwater contamination in urban cities is imminent in the phase of increased anthropogenic activities apart from the contribution of geogenic contaminants. This study examined the sanitary surveys and hydrochemistry of groundwater in Ado-Ekiti and Ijero-Ekiti to establish the contaminants’ sources, decipher the effects of urbanization on population and explain any relationship between the surveys and the groundwater chemistry. Sanitary surveys of 30 randomly selected wells each from Ado-Ekiti and Ijero-Ekiti were executed by administering and processing appropriately designed questionnaires that addressed salient problems of hygiene and sanitation. The results of the surveys were grouped into very high risk, high risk, intermediate risk, and low risk classes. Subsequently, at each location, in situ parameters (temperature (°C), pH and EC (μS/cm)) were measured using a portable Multi-parameter TestrTM 35 Series S/N: 1382654. At each well, water samples were collected into clean polyethylene bottles in triplicates for cation, anions and e-coli evaluations, respectively. Water samples for cations were acidified by adding two drops of concentrated nitric acid. All samples were kept in a refrigerator at a low temperature of about 4°C before being taken to the Federal University of Technology, Akure, for analyses. Ion chromatography was employed for the anions analysis while the cations were determined using an Atomic Absorption Spectrophotometer Buck 210 model. Membrane filter technique was employed for the e-coli estimation. From the results of the hydrochemistry, the Nitrate Pollution Index (NPI) and Modified Nitrate Pollution Index (MNPI) were estimated and classified into;clean unpolluted, light pollution, moderate pollution, significant pollution, very significant pollution waters. Sanitary surveys in the two cities showed that in the very low risk, intermediate and high-risk categories, Ado-Ekiti had 33.33%, 56.67% and 10% representations, while Ijero-Ekiti had 50%, 23.33% and 26.67% representations, respectively. This observation showed that Ado-Ekiti with higher population and humans’ activities compared to Ijero-Ekiti was less susceptible to pollution. Urbanization has no direct effects on sanitary surveys. The pH of wells’ water in Ado-Ekiti ranged from 4.8 - 8.2, EC (μS/cm) from 101 - 1008, while at Ijero-Ekiti, the pH and EC (μS/cm) varied from 2.1 - 13.8 and 80 - 1008 respectively. Ado-Ekiti wells’ water was more acidic than that of Ijero-Ekiti. Chemical concentrations (mg/L) of Ca<sup>2+</sup>, Mg<sup>2+</sup>, Na<sup>+</sup>, K<sup>+</sup>, , and Cl<sup>ˉ</sup> of the wells’ water in both cities were within WHO-approved standards for drinking water. However, with average concentrations of 142.17 (mg/L) and 252.71 (mg/L) at Ado-Ekiti and Ijero-Ekiti, respectively, exceeded the standard in many locations. Susceptibility to pollution classification employing TDS, NPI and MNPI showed that Ijero-Ekiti was more susceptible to pollution compared to Ado-Ekiti. This assertion was supported by statistical analysis employing correlation, cluster analysis, and principal component analysis. This study showed that urbanization had no direct effects on sanitary surveys and groundwater quality. Pollution of wells’ water in the two cities was, mainly from anthropogenic activities. However, Ijero-Ekiti, with significant anthropogenic activities, had its wells’ water more susceptible to pollution. Sanitary surveys are a complementary method to water quality monitoring. 展开更多
关键词 URBANIZATION Groundwater Quality Geogenic Contaminants Sanitary surveys HYDROCHEMISTRY Nitrate Pollution Index
下载PDF
“Tasks”versus“Disciplines”:The Comprehensive Surveys of Natural Resources by the Chinese Academy of Sciences,and the Politics of Science Policy in the People’s Republic of China
20
作者 Zhang Jiuchen 《Chinese Annals of History of Science and Technology》 2018年第1期123-139,共17页
As soon as the Chinese Academy of Sciences(CAS)was founded by the new government of the People’s Republic of China in 1949,the principles of“linking theory with practice”and“conducting research to serve the people... As soon as the Chinese Academy of Sciences(CAS)was founded by the new government of the People’s Republic of China in 1949,the principles of“linking theory with practice”and“conducting research to serve the people”set the framework for its scientific studies.How to balance their obligations to facilitate national economic construction with their desires to advance disciplinary scientific developments posed a knotty problem that frustrated those who organized and engaged in scientific research across the country,and in the CAS in particular.Against this background,the slogan“let tasks lead disciplines”was proposed as an effective solution.However,how exactly to put this into practice became a pressing issue,as CAS scientists and scholars debated the relationship between tasks and advances within scientific disciplines.This paper examines these debates as they were carried out in the case of the comprehensive surveys of natural resources organized by the CAS,focusing especially on different understandings of the relationship between“tasks”and“disciplines”within the CAS in the early 1960s,and examining the impact and legacy of“letting tasks lead disciplinary developments,”with possible lessons for the formulation of scientific plans today. 展开更多
关键词 “linking theory with practice ”tasks DISCIPLINES the Comprehensive surveys of Natural Resources Chinese Academy of Sciences
下载PDF
上一页 1 2 91 下一页 到第
使用帮助 返回顶部