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The Background Features and Formation of Chemical Elements of Groundwater in the Region of the Middle and Lower Reaches of the Yangtze River 被引量:17
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作者 Zeng Zhaohua Institute of Environmental Geology,Jiangxi Bureau of Geology and Mineral Resources, Nanchang, Jiangxi Shang Ruoyun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1997年第1期80-89,共10页
The paper deals with the background features, formation and distribution of the chemical el-ements K, Na, Ca, Mg, Si, Fe, Mn, Cr, Ni,V, Co, Ti, Mo, Cu, Pb, Zn, As, Hg, Cd, Be, Li, Sr, B,F, Cl, Br and I in the groundwa... The paper deals with the background features, formation and distribution of the chemical el-ements K, Na, Ca, Mg, Si, Fe, Mn, Cr, Ni,V, Co, Ti, Mo, Cu, Pb, Zn, As, Hg, Cd, Be, Li, Sr, B,F, Cl, Br and I in the groundwater in the region of the middle and lower reaches of the YangtzeRiver and their relations to the composition of the water-bearing media, properties of the overly-ing rocks and soils, redox environment, and groundwater flow condition, mineralization and pHof groundwater. 展开更多
关键词 lower-middle reaches of the Yangtze River GROUNDWATER chemical element background feature
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Phases of Environmental Evolution Indicated by Primary Chemical Elements and Paleontological Records in the Upper Pleistocene-Holocene Series for the Salawusu River Valley,China 被引量:17
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作者 LI Baosheng WEN Xiaohao +5 位作者 QIU Shifan David Dian ZHANG DU Shuhuan CHEN Deniu OU Xianjiao NIU Dongfeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2007年第4期555-565,共11页
Studies of lithology, sedimentary facies and the distribution regularity of SiO2 and Al2O3 contents and Al2O3/SiO2 ratio allow us to divide the Upper Pleistocene-Holocene Series represented by the MUanggouwan section ... Studies of lithology, sedimentary facies and the distribution regularity of SiO2 and Al2O3 contents and Al2O3/SiO2 ratio allow us to divide the Upper Pleistocene-Holocene Series represented by the MUanggouwan section in China's Salawnsu River valley into six segments: MGS1, MGS2, MGS3, MGS4, MGS5 and MGS6. The boundary ages for MGS1 (the Dishaogouwan and Dagouwan Formations), MGS2 (the upper Chengchuan Formation), MGS3 (the middle Chengchuan Formation), MGS4 (the lower Chengchuan Formation), MGS5 (most strata of the Salawusu Formation) and MGS6 (the bottom of the Salawusu Formation and the top of the Lishi Formation) correspond to those of MIS1, MIS2, MIS3, MIS4, MISS and MIS6, respectively, from deep sea sediments or continental glaciers. MGS5 can be subdivided into five subsegments (MGS5a, MGS5b, MGS5c, MGS5d and MGS5e) and the boundary ages of these subsegments correspond to those of MISSa, MISSb, MIS5c, MIS5d and MIS5e, respectively. Based on the paleoenvironment and paleoecology indicated by the primary chemical elements, fossil vertebrates, mollusks and pollen grains, we hypothesize that MGS1, MGS2, MGS3, MGS4, MGS5 and MGS6 and the subsegments of MGS5 match the corresponding stages for oxygen isotopes in the deep sea sediments and continental glaciers, and the substages of MIS5 in terms of climatic characters, further explaining the phenomena that determined the formation of the late Quaternary strata and the paleontology of the Salawusu River valley. These phenomena relate to fluctuations in the global climate (and particularly in the East Asian monsoon) during the glacial and interglacial periods. 展开更多
关键词 Salawusu River valley Upper Pleistocene-Holocene Series primary chemical elements phases of evolution paleontological records
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Concentration Characteristics and Sources of Chemical Elements in Atmospheric Fine Particles (PM_(2.5)) in Autumn in Xi'an City 被引量:1
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作者 GAN Xiao-feng1,2, CAO Jun-ji2,3, WANG Qi-yuan4, SHEN Zhen-xing4, XU Hong-mei2 1. Department of Environmental Science and Technology, Xi’an Jiaotong University, Xi’an 710049, China 2. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, China +1 位作者 3. Institute of Global Environmental Change, Xi’an Jiaotong University, Xi’an 710049, China 4. Department of Environmental Engineering, Xi’an Jiaotong University, Xi’an 710049, China 《Meteorological and Environmental Research》 CAS 2011年第4期5-8,共4页
[Objective] The aim was to study the concentration characteristics and sources of chemical elements in atmospheric fine particles (PM2.5) in autumn in Xi’an City. [Method] By means of mini-volume sampler, PM2.5 sampl... [Objective] The aim was to study the concentration characteristics and sources of chemical elements in atmospheric fine particles (PM2.5) in autumn in Xi’an City. [Method] By means of mini-volume sampler, PM2.5 samples in atmosphere in Xi’an were collected in October 2009, and the concentration characteristics and sources of elements in PM2.5 were analyzed. [Result] The average mass concentration of PM2.5 in atmosphere in autumn in Xi’an City was 168.44 μg/m3 which was higher than that of Beijing and Pearl River Delta area, and the minimum and maximum value were 53.29 and 358.16 μg/m3, respectively. The mass concentration of S, Zn, K, Cl, Ca and Fe in PM2.5 was above 1.0 μg/m3, being at high pollution level. In addition, K had obvious correlation with organic carbon (OC) and element carbon (EC), with the correlation coefficients of 0.76 and 0.75 (P<0.000 1), respectively, and it showed that OC and EC had the same source as K, namely biomass burning had certain contribution to OC and EC. Enrichment factors analysis revealed that K, Ca, Fe, Ti, Mn and Cr mainly came from earth crust, rock weathering and other natural sources, while anthropogenic pollution sources had great effects on S, Zn, Cl, Pb, Br, Mo, Cd and As which were affected by soil dust and other natural sources slightly, and Cd had the highest enrichment factor and mainly came from metal smelting. In a word, coal combustion, biomass burning, vehicle emissions, metallurgical, chemical industry and dust were the main sources of PM2.5 in autumn in Xi’an. [Conclusion] The study could provide theoretical foundation for the control of urban environmental pollution. 展开更多
关键词 Atmospheric fine particles chemical element Enrichment factor Factor analysis China
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Chemical element transfer of weathering granite regolith in the Three Gorges Dam region of Yangtze River
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作者 Zhang Li-ping Zhu Da-kui Yang Da-yuan 《Journal of Geographical Sciences》 SCIE CSCD 2002年第2期113-119,共7页
Clearing up sediment and regolith on the foundation of the dam in the Three Gorges of the Yangtze River in 1999, riverbed were exposed. On the basis of weathering granite regolith sampled from different portions of th... Clearing up sediment and regolith on the foundation of the dam in the Three Gorges of the Yangtze River in 1999, riverbed were exposed. On the basis of weathering granite regolith sampled from different portions of the valley landforms, by analysing total chemical contents with X rays fluorescent slice and calculating proper value of chemical element transferring ratio and intensity, the transferring law of chemical elements in different portions of the landforms were concluded: 1) In various landforms of the river valley, the process of desilication is not distinct; 2) in weathering granite regolith of riverbed, easy soluble CaO and MgO are relatively enriched whereas Al2O3 tends to decrease. The enriching rate of Fe2O3 is the greatest in various landforms of the river valley; 3) in weathering granite regolith of flood-plain, K2O and MgO contents are relatively enriched; 4) the weathering granite regolith of valley slope is a typical north subtropical weathering regolith, and its chemical weathering degree is in the transition phase from early to middle period; and 5) there is an opposite layer where K2O is relatively leaching and Na2O relatively enriching in 6.5 m depth of all weathering granite regolith. 展开更多
关键词 Three Gorges Dam weathering regolith chemical element transferring
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Comparison of 66 chemical element contents in normal and benign hyperplastic prostate
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作者 Vladimir Zaichick Sofia Zaichick 《Asian Journal of Urology》 CSCD 2019年第3期275-289,共15页
Objective:The aim of this study was to clarify the differences between the prostatic levels of chemical elements in patients with benign prostatic hyperplasia(BPH)and healthy male.Methods:We evaluated the prostatic le... Objective:The aim of this study was to clarify the differences between the prostatic levels of chemical elements in patients with benign prostatic hyperplasia(BPH)and healthy male.Methods:We evaluated the prostatic level of 66 chemical elements in 43 patients with BPH and 37 healthy males.Measurements were performed using five instrumental analytical methods.Results:In the hyperplastic prostates,we have observed a significant increase in the mean level of Bi,Cr,Hg,K,Sb,and Se accompanied a significant decrease in the mean level of Al,Ce,Cs,Dy,Er,Gd,Ho,La,Mo,Nd,Pb,Pr,Sm,Sn,Tb,Tm,U,and Y.No differences were found in the mean prostatic level of other chemical elements including Ag,Al,Au,B,Ba,Be,Br,Ca,Cd,Co,Cu,Fe,Li,Mg,Mn,Na,Nb,Ni,P,Rb,S,Sc,Si,Th,Ti,Tl,Yb,Zn,and Zr between BPH patients and healthy males.Conclusions:The finding of chemical element contents and correlation between pairs of chemical element mass fractions indicates that there is a great disturbance of prostatic chemical element metabolism in BPH gland.Trace elements Bi,Cr,Hg,K,Sb,and Se may be regarded as the possible tissue biomarkers of hyperplastic transformation of prostate gland.Obtained data did not confirm a critical role of Cd and Pb accumulation in the pathogenesis of BPH.A potential age-related Zn,Fe,and Se deficiency in the prostate tissue has not been found as being involved in the etiology of BPH. 展开更多
关键词 Benign prostate hyperplasia Prostatic chemical element contents Trace element supplementations Energy dispersive Xray fluorescence analysis Neutron activation analysis Inductively coupled plasma atomic emission and mass spectrometry
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The Astrophysical Processes of Cosmological Hydrogen that Generate the Chemical Elements that Make up the Universe
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作者 M. Javier Cruz Gómez Salvador Galindo Uribarri Olga B. Benítez López 《Natural Science》 2021年第3期103-116,共14页
The objective of the present article is to explain how all the chemical elements were formed from the big bang generated element: hydrogen. The methodology used was to analyze the main cosmological and astrophysical p... The objective of the present article is to explain how all the chemical elements were formed from the big bang generated element: hydrogen. The methodology used was to analyze the main cosmological and astrophysical processes in order to explain the origin of all the known chemical elements. The main results are: Hydrogen cannot be formed in any part of the actual universe;it must come from the Big Bang. Helium and a little bit of lithium can have a cosmological origin associated to the Big Bang nucleosynthesis and the recombination process. The elements with an atomic number between 3 and 26 were, and continue to be, synthetized by </span><span style="font-family:Verdana;font-size:12px;">nuclear fusion reactions inside the core of massive stars and liberated by explosion when the stars go supernovae, at the end of their lives. In the process of going supernova, elements with a medium atomic number, between 27 and 40, are created. All the elements with an atomic number larger than 40 were generated by neutron star collisions. When Mendeleev and Lothar Meyer designed an ordered arrangement of chemical elements, their tables included the 63 chemical elements known in 1869. A century and a half later, the known elements are 118. By studying different topics related to the elements, it was possible to uncover fundamental particles, such as quarks and leptons, and the strong and weak nuclear forces that form the baryonic part of the universe. The Sun was formed 6000 million years ago and its planets, including earth, were formed 4600 million years ago when and where there were debris of different stars that went supernova, in particular 1A type, and also debris, of at least one of a binary neutron star collision, so to attain, all the elements that have been identified in the solar system, and especially in earth. In addition, the current “periodic table” includes 26 synthetic elements that were produced in neutron star collisions but, because of their short lifetimes, they are not found, on earth. The vast quantities of the elements, produced during the aforementioned astrophysical processes, clustered into planets, stars and galaxies;and at least in one planet, our earth, some chemical elements organized themselves into living creatures. 展开更多
关键词 Origin of chemical elements Fundamental Particles Nuclear Reactions Inside the Stars Binary Stars Neutron Star Collision
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Estimating heat capacities of liquid organic compounds based on elements and chemical bonds contribution
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作者 Li Xia Yule Pan +4 位作者 Tingting Zhao Xiaoyan Sun Shaohui Tao Yushi Chen Shuguang Xiang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第5期30-38,共9页
Molecular property depends on the property, the number of the elements, and the interaction between elements(such as chemical bonds). Based on the above-mentioned idea, two methods to estimate the isobaric heat capaci... Molecular property depends on the property, the number of the elements, and the interaction between elements(such as chemical bonds). Based on the above-mentioned idea, two methods to estimate the isobaric heat capacity of liquids organic compounds were developed. Ten elements groups and 32 chemical bond groups were defined by considering the structure of organic compounds. The group contribution values and correlation parameters were regressed by the ridge regression method with the experiment data of 1137 compounds. The heat capacity can be calculated by summating the contributions of the elements and chemical bond groups. The two methods were compared with existing group contribution methods, such as Chickos, Zabransky-Ruzicka, and Zdenka Kolska. The results show that those new estimation methods' overall average relative deviations were 5.81% and 5.71%, which were lower than the other three methods. Those methods were more straightforward in compound splitting.Those new methods can be used to estimate the liquid heat capacity of silicon-containing compounds,which the other three methods cannot estimate. The new methods are more accessible, broader, and more accurate. Therefore, this research has important scientific significance and vast application prospects. 展开更多
关键词 Thermodynamic Properties MODEL PREDICTION elements and chemical Bonds
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Size distribution of chemical elements and their source apportionment in ambient coarse, fine, and ultrafine particles in Shanghai urban summer atmosphere 被引量:22
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作者 Senlin Lu Rui Zhang +5 位作者 Zhenkun Yao Fei Yi Jingjing Ren Minghong Wu Man Feng Qingyue Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第5期882-890,共9页
Ambient coarse particles (diameter 1.8-10 μm), fine particles (diameter 0.1-1.8 μm), and ultrafine particles (diameter 〈 0.1 μm) in the atmosphere of the city of Shanghai were sampled during the summer of 20... Ambient coarse particles (diameter 1.8-10 μm), fine particles (diameter 0.1-1.8 μm), and ultrafine particles (diameter 〈 0.1 μm) in the atmosphere of the city of Shanghai were sampled during the summer of 2008 (from Aug 27 to Sep 08). Microscopic characterization of the particles was investigated by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX). Mass concentrations of Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, and Pb in the size-resolved particles were quantified by using synchrotron radiation X-ray fluorescence (SRXRF). Source apportionment of the chemical elements was analyzed by means of an enrichment factor method. Our results showed that the average mass concentrations of coarse particles, fine particles and ultrafine particles in the summer air were 9.38 ± 2.18, 8.82 ± 3.52, and 2.02 ± 0.41 μg/m3, respectively. The mass percentage of the fine particles accounted for 51.47% in the total mass of PM10, indicating that fine particles are the major component in the Shanghai ambient particles. SEM/EDX results showed that the coarse particles were dominated by minerals, fine particles by soot aggregates and fly ashes, and ultrafine particles by soot particles and unidentified particles. SRXRF results demonstrated that crustal elements were mainly distributed in the coarse particles, while heavy metals were in higher proportions in the fine particles. Source apportionment revealed that Si, K, Ca, Fe, Mn, Rb, and Sr were from crustal sources, and S, Cl, Cu, Zn, As, Se, Br, and Pb from anthropogenic sources. Levels of P, V, Cr, and Ni in particles might be contributed from multi-sources, and need further investigation. 展开更多
关键词 airborne size-resolved particles chemical elements distribution source apportionment
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Levels of chemical element contents in thyroid as potential biomarkers for cancer diagnosis (a preliminary study)
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作者 Vladimir Zaichick Sofia Zaichick 《Journal of Cancer Metastasis and Treatment》 CAS 2018年第1期702-716,共15页
Aim:Thyroid cancer is an internationally important health problem.The aim of this exploratory study was to evaluate whether significantchanges in the thyroid tissue levels of Al,B,Ba,Br,Ca,Cl,Cu,Fe,I,K,Li,Mg,Mn,Na,P,S... Aim:Thyroid cancer is an internationally important health problem.The aim of this exploratory study was to evaluate whether significantchanges in the thyroid tissue levels of Al,B,Ba,Br,Ca,Cl,Cu,Fe,I,K,Li,Mg,Mn,Na,P,S,Si,Sr,V,and Zn exist in the malignantly transformed thyroid.Methods:Thyroid tissue levels of twenty chemical elements were prospectively evaluated in 41 patients with thyroid malignant tumors and 105 healthy inhabitants.Measurements were performed using a combination of non-destructive and destructive methods:instrumental neutron activation analysis and inductively coupled plasma atomic emission spectrometry,respectively.Tissue samples were divided into two portions.One was used for morphological study while the other was intended for trace element analysis.Results:It was found that contents of Al,B,Br,Ca,Cl,Cu,K,Mg,Mn,Na,P,S,and Si were significantly higher(approximately 3.2,4.6,9.3,1.8,2.3,3.6,1.6,1.6,1.6,1.2,2.5,1.1,and 2.8 times,respectively)while content of I lower(nearly 26 times)in cancerous tissues than in normal tissues.Conclusion:There are considerable changes in chemical element contents in the malignantly transformed tissue of thyroid. 展开更多
关键词 Thyroid malignant tumors intact thyroid chemical elements biomarkers for cancer diagnosis instrumentalneutron activation analysis inductively coupled plasma atomic emission spectrometry
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Digital Element Earth 被引量:11
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作者 XIE Xuejing WANG Xueqiu CHENG Hangxin CHENG Zhizhong YAO Wensheng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2011年第1期1-16,共16页
The resources and environmental problems are the two most fundamental issues facing all nations in the world. Everything in and on the Earth - minerals, animals and plants -is made from one, or generally some combinat... The resources and environmental problems are the two most fundamental issues facing all nations in the world. Everything in and on the Earth - minerals, animals and plants -is made from one, or generally some combination of, chemical elements, which are scientifically listed in the periodic table. Thus it is important to understand the present abundance and spatial distribution of all the elements across the Earth's surface. Such kinds of data can only be obtained at present and for the foreseeable future by on-earth geochemical mapping at all scales. The 30-year efforts made by Chinese geochemists in carrying out multi-element, multi-media, multi-scale geochemical mapping projects to delineate 39-76 element distribution at home and abroad culminated in a successful case of high- quality geochemical data acquirement. The new idea for a four-level plan for global geochemical mapping was advanced to obtain global data in the foreseeable future and the collection of updated geochemical information. Such information needs to be easily accessible not only by the science community, but also by industry, agriculture, governments, and even individuals, by all who would make an effort to promote sustainable riving on our planet. The concept of a Digital Element Earth (DEE) fulfills the aims. 展开更多
关键词 Digital element Earth chemical elements geochemical mapping sustainable development
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Assessment of soil degradation and chemical compositions in Rwandan tea-growing areas 被引量:2
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作者 Jean de la Paix Mupenzi Lanhai Li +4 位作者 Jiwen Ge Achal Varenyam Gabriel Habiyaremye Nzayisenga Theoneste Kamanzi Emmanuel 《Geoscience Frontiers》 SCIE CAS 2011年第4期599-607,共9页
This study has focused on the processes of soil degradation and chemical element concentration in tea-growing regions of Rwanda,Africa.Soil degradation accelerated by erosion is caused not only by topography but also ... This study has focused on the processes of soil degradation and chemical element concentration in tea-growing regions of Rwanda,Africa.Soil degradation accelerated by erosion is caused not only by topography but also by human activities.This soil degradation involves both the physical loss and reduction in the amount of topsoil associated with nutrient decline.Soil samples were collected from eleven tropical zones in Rwanda and from variable depth within each collecting site.Of these,Samples from three locations in each zone were analyzed in the laboratory,with the result that the pH of all soil samples is shown to be less than 5(pH〈5) with a general average of 4.4.The elements such as iron(Fe), copper(Cu),manganese(Mn),and zinc(Zn) are present in high concentration levels.In contrast calcium (Ca) and sodium(Na) are present at low-level concentrations and carbon(C) was found in minimal concentrations.In addition,elements derived from fertilizers,such as nitrogen(N),phosphorous(P),and potassium(K) which is also from minerals such as feldspar,are also present in low-level concentrations. The results indicate that the soil in certain Rwandan tea plantations is acidic and that this level of pH may help explain,in addition to natural factors,the deficiency of some elements such as Ca,Mg,P and N.The use of chemical fertilizers,land use system and the location of fields relative to household plots are also considered to help explain why tea plantation soils are typically degraded. 展开更多
关键词 chemical elements Fertilizer use PH Soil degradation Tea plantations
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Principles of Technology for Bottling Medicinal Mineral Waters of Sairme Using the Example of Source №3a
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作者 Irina Nikolaishvili Giorgi Kvartskava 《American Journal of Analytical Chemistry》 CAS 2024年第4期135-138,共4页
Sairme mineral water, one of the famous mineral waters in Georgia, is renowned for its exceptional healing properties. The distinctiveness and therapeutic benefits of the naturally sourced mineral water, known as “Sa... Sairme mineral water, one of the famous mineral waters in Georgia, is renowned for its exceptional healing properties. The distinctiveness and therapeutic benefits of the naturally sourced mineral water, known as “Sairme”, stem from its rich array of microelements, notably including iron and manganese. Since 1948, the bottling of Sairme mineral water has been a prominent activity. Named after the Sairme deposit, this mineral water is packaged in various formats to cater to diverse consumer preferences. The bottling process involves transporting the mineral water from wells to the bottling plant through pipelines. Prior to bottling, the mineral water undergoes meticulous processing stages in adherence to current Georgian and international regulations. This process ensures that the concentration of trace elements in the bottled water is minimized, maintaining its purity and quality. Given the importance of preserving the microelements present in bottled mineral water, our research is dedicated to optimizing the technological process. Our objective is to safeguard the valuable microelements while ensuring the highest standards of quality and safety in the final product. 展开更多
关键词 Sairme Mineral Water Deposit Oxidation-Reduction Potential Trace elements chemical Composition SEASONALITY
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The Theory of Four Elements Through History and Its Influence on the Development of Chemistry
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作者 Roberto Barbosa de Castilho 《Journal of Philosophy Study》 2021年第12期914-922,共9页
The theory of four elements(or roots)was the first plural attempt to explain life and change and was based on the combination of four different roots that give rise to life and matter.The four elements(fire,air,water ... The theory of four elements(or roots)was the first plural attempt to explain life and change and was based on the combination of four different roots that give rise to life and matter.The four elements(fire,air,water and earth)were thought to be the building blocks of all substances.This theory was derived from observation and reason and it might be viewed as a material or substancialist theory.Its development brought important concepts such as equilibrium,proportion and combination to chemistry and medicine.The aim of the present paper is to describe the theory of four elements,its origin and development from Empedocles and Aristotle to Roulle and Beeckman.Although the conception of the chemical elementsin modern chemistry is different from the theory of four elements,that theory was valuable as an intellectual effort to understand nature and transmutation and to conciliate reason and senses,besides being the first theory postulating the pluralism of matter’s composition,in opposition to monism.I argue that chemistry has a past and it is important to know the theory of the four elements for its historical value because it can be considered an introductory chapter of chemistry,introducing the concepts of indestructible elements and the proportional combination of them in Western thought. 展开更多
关键词 four elements chemical element pre-Socratic philosophers transmutations BACHELARD
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Design method of extractant for liquideliquid extraction based on elements and chemical bonds
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作者 Yuwen Wei Chunling Zhang +4 位作者 Yue Zhang Lili Wang Li Xia Xiaoyan Sun Shuguang Xiang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS 2024年第4期193-202,共10页
In the petrochemical industry process,the relative volatility between the components to be separated is close to one or the azeotrope that systems are difficult to separate.Liquideliquid extraction is a common and eff... In the petrochemical industry process,the relative volatility between the components to be separated is close to one or the azeotrope that systems are difficult to separate.Liquideliquid extraction is a common and effective separation method,and selecting an extraction agent is the key to extraction technology research.In this paper,a design method of extractants based on elements and chemical bonds was proposed.A knowledge-based molecular design method was adopted to pre-select elements and chemical bond groups.The molecules were automatically synthesized according to specific combination rules to avoid the problem of“combination explosion”of molecules.The target properties of the extractant were set,and the extractant meeting the requirements was selected by predicting the correlation physical properties of the generated molecules.Based on the separation performance of the extractant in liquideliquid extraction and the relative importance of each index,the fuzzy comprehensive evaluation membership function was established,the analytic hierarchy process determined the mass ratio of each index,and the consistency test results were passed.The results of case study based on quantum chemical analysis demonstrated that effective determination of extractants for the analysis of benzeneecyclohexane systems.The results unanimously prove that the method has important theoretical significance and application value. 展开更多
关键词 Molecular design element and chemical bonds Molecular simulation Thermodynamics Solvent extraction
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Deposition of sandstorms in a vegetation-covered sand dune in Ejin Oasis and its characteristics 被引量:3
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作者 WENXiaohao LI Baosheng +3 位作者 WANG Wei LI Sen OU Xianjiao ZHENG Yanming 《Journal of Geographical Sciences》 SCIE CSCD 2006年第4期502-508,共7页
"Ejin Section" found in a typical vegetation-covered sand dune in Ejin Oasis was investigated. In this study, 263 samples were taken from the section for grain-size analysis, 25 for chemical analysis, 11 for ^14C da... "Ejin Section" found in a typical vegetation-covered sand dune in Ejin Oasis was investigated. In this study, 263 samples were taken from the section for grain-size analysis, 25 for chemical analysis, 11 for ^14C dating and 6 for scanning electron microscope (SEM). The results of the study indicate that 3 types of the sediments in the section can be identified, YS, LS and ST. YS, homogeneous yellow-brown dune sands, is equal to those of inland deserts, LS, loess-like sandy soils, is the same as the sandy loess in the middle Yellow River and modem falling dusts, and ST, sandy sediments interbeded with the deadwood and defoliation of Tamarix spp, represents the depositional process of the section interrupted by abrupt changes in climate. The Ejin Section has recorded the repeated dust-storms or sandstorms since 2500 yr BP and the peak periods of the dust-storms or sandstorms revealed by the section are consistent with the records of "dust rains" in historical literatures, indicating that the change of climate is a key factor to increase sandstorms or dust-storms, whereas, "artificial" factor may only be an accelerating one for desertification. 展开更多
关键词 Ejin Oasis vegetation-covered sand dune dust storm SANDSTORM grain size major chemical element
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沙地草场植物根系化学元素含量的特征 被引量:2
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作者 黄德华 陈佐忠 《植物生态学与地植物学学报》 CSCD 北大核心 1989年第4期372-378,共7页
本文报道了内蒙古沙地草场不同植物根系的化学元素含量特征。结果表明:51种植物根系的N、P、K、Si、Na、Fe和灰分的平均含量分别为1.08%、0.104%、0.686%、0.811%、0.049%、0.030%和6.416%。其中相同植物根系的N、P、K、Na和灰分的含量... 本文报道了内蒙古沙地草场不同植物根系的化学元素含量特征。结果表明:51种植物根系的N、P、K、Si、Na、Fe和灰分的平均含量分别为1.08%、0.104%、0.686%、0.811%、0.049%、0.030%和6.416%。其中相同植物根系的N、P、K、Na和灰分的含量低于其地上部分的平均含量,而Si和Fe相反,根系的平均含量高于其地上部分。 展开更多
关键词 沙地草场 根系 化学元素含量
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The use of the white poplar(Populus alba L.)biomass as fuel 被引量:1
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作者 TatianaGriu AurelLunguleasa 《Journal of Forestry Research》 SCIE CAS CSCD 2016年第3期719-725,共7页
We determined the calorific value of white poplar(Populus alba L.) woody biomass to use it as firewood. The value of 19.133 MJ kg-1obtained experimentally shows that the white poplar can be quite successfully used a... We determined the calorific value of white poplar(Populus alba L.) woody biomass to use it as firewood. The value of 19.133 MJ kg-1obtained experimentally shows that the white poplar can be quite successfully used as firewood. Being of a lower quality in comparison with usual beech firewood, the white poplar has similar calorific value. The white poplar has a calorific density of 30.7 % lower than that of current firewood. That is why the price of this firewood from white poplar is lower accordingly. Also, the prognosis of calorific value on the basis of the main chemical elements, being very close to the experimental value(+2.6 %), indicates an appropriate value can be achieved to be used for investigation with the chemical element analysis. 展开更多
关键词 Calorific value chemical elements PROGNOSIS White poplar
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The Negative Effect of Heavy Metal Salts on the Body of Mammal Animals
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作者 Munisa Bakhrillaeva Zaynitdin Razamuradov 《Open Journal of Animal Sciences》 CAS 2022年第4期704-711,共8页
The main purpose of this presented article was to explain the need to study the amount of heavy metal salts in the environment where animals live, in the water, in air, and in the food and fodder consumed. This articl... The main purpose of this presented article was to explain the need to study the amount of heavy metal salts in the environment where animals live, in the water, in air, and in the food and fodder consumed. This article presents materials from the literature on the effects of heavy metal salts on the body of animals and the environment in which they live. The cited analytical data showed that the general information on the negative effects of heavy metal salts on the body is sufficient, but their effects on the digestive tract and morpho-functional properties of rabbits should be studied in depth. Therefore, we planned to focus our scientific work on this topic. The article mainly refers to salts of heavy metals cadmium, lead, and mercury (Cd, Pb, Hg). It is noted in the literature that heavy metal salts have a negative effect on the body of animals. We focused mainly on data on the effects of heavy metals on farm animals, including rabbits. But it is clear that the authors referred to were referring to experimental animals. These negative effects are manifested in the form of disorders of digestive functions, disorders of neurovegetative processes, increasing incidence of cardiovascular disease, rapid heart failure, deterioration of calcium metabolism, as well as impaired haemoglobin metabolism. Disorders of protein metabolism manifest themselves in the form of cases of hyperproteinaemia and dysproteinaemia. The results of the evaluation of the organism of healthy animals in chemically and radioactively contaminated areas showed the accumulation of significant levels of chemical elements in their organism. We mainly looked at the effects of heavy metal salts on farm animals. The cited analytical data showed that the general information on the negative effects of heavy metal salts on the body is sufficient, but the effects on the activity of organ systems in the body (respiration, blood and blood circulation, digestion, reproduction, productivity and immunological systems) have not been comprehensively studied. 展开更多
关键词 chemical elements ANIMALS ORGANISMS NUTRIENTS Food Products Environment Diseases Heavy Metal Salts Cadmium Lead POISONING
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The Comparison of Three Environmental Metrics for Cr, Pb, and Zn in the Agricultural Region of the Mid-Continent of USA
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作者 Almesleh A. A. Najwah Goodell Philip 《Journal of Geoscience and Environment Protection》 2021年第4期147-165,共19页
The chemical and physical properties of soil are critical factors that affect human health. The current geochemical study is designed to evaluate the concentrations of heavy metals (Cr, Pb, and Zn) in the soil in Iowa... The chemical and physical properties of soil are critical factors that affect human health. The current geochemical study is designed to evaluate the concentrations of heavy metals (Cr, Pb, and Zn) in the soil in Iowa (IA), Kansas (KS), and Nebraska (NE). The basic descriptive statistical results suggest that there are some limited levels of the heavy metals in the soils that come from anthropogenic inputs. The results of three environmental metrics, the enrichment factor (EF), geoaccumulation (Igeo), and potential ecological risk (PERI), have been calculated, evaluated, and compared. EF values show that soils contain minimal enrichment of Cr, Pb, and Zn in the study area. In addition, PERI values presented low risk with Cr, Pb, and Zn. However, Igeo </span><span style="font-family:Verdana;">values showed no contamination of Cr, Pb, and Zn in the study area. These results suggest that the elevated levels of these heavy metals are dominated by the historic agricultural inputs derived from long-term anthropogenic applications, especially in the regions with extensive human activities, which means that soil is the sink for heavy metals released into the environment. 展开更多
关键词 chemical elements Enrichment Factor Geo Accumulation Potential Ecological Risk Geochemical Maps
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Radiological Effectual and Mineral Salts Measurements of Sandstone Used in the Construction from Al Wajh, Al Ula and North Al Ula, Az Zabirah-Saudi Arabia
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作者 Safia H. Q. Hamidalddin 《Journal of Geoscience and Environment Protection》 2022年第9期84-95,共12页
The activity concentrations of natural radionuclides <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K, were measured in (16) sandstone samples collected from two regions of Sau... The activity concentrations of natural radionuclides <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K, were measured in (16) sandstone samples collected from two regions of Saudi Arabia, Region 1 (Al Wajh on Red Sea coast and Al Ula north-East of Medina), Region 2 (North of Al Ula and Az Zabirah, North-West of Hail) by (HPGe gamma spectrometer). The activity concentration average values of the radionuclides <sup>226</sup>Ra, <sup>232</sup>Th, and <sup>40</sup>K in the sandstone samples (Region 1) ranged from 10.97 ± 0.43, 27.68 ± 0.37 and 64.56 ± 0.74 Bq/kg respectively. These values are less than the international values reported by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 2000), in (Region 2), average values ranged from 2465.49 ± 0.00, 2042.00 ± 0.00 and 2259.65 ± 0.64 Bq/kg respectively. These values are higher than the values reported by (UNSCEAR, 2000). Average values of radium equivalent activity Ra<sub>eq</sub> (Bq/Kg), absorbed dose rate D (nGy/h), annual effective radiation dose D<sub>eff</sub> (mSv/y), External index (H<sub>ex</sub>) and Internal index (H<sub>in</sub>) were in (region 1) 21.13, 27.22, 11.75, 0.07 and 0.10 respectively, in (region 2) 5775.19, 1787.78, 846.58, 11.57 and 15.64 respectively. These results are lower (except annual effective radiation dose) in (region 1) and higher in (region 2) than the world recommended values by (UNSCEAR, 2000). Also, samples were analyzed by Atomic Absorption spectrometer (AAS) for Al, Ca, Fe, K, Mg and Bi in % elements concentrations. Average value in (region 1) (Al Wajh and Al Ula) are 4.42, 0.41, 1.37, 0.04 and 0.03, (in region 2) (N. Al Ula and Az Zabirah) are 12.50, 10.05, 1.01, 1.19, 0.04 respectively. Classifications of sandstone depend on the content of these elements. These results are important for the safety of dwellers and user of sandstone in constructions. 展开更多
关键词 Gamma Spectrometer AA Spectrometer Natural Radioactivity chemical elements
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