期刊文献+
共找到2,042篇文章
< 1 2 103 >
每页显示 20 50 100
CONTENT AND DISTRIBUTION OF TRACE ELEMENTS IN SOILS OF THE DAM RIVER AND TUOTUO RIVER BASINS
1
作者 邵庆春 邓伟 孙广友 《Chinese Geographical Science》 SCIE CSCD 1995年第2期157-169,共13页
Natural contents and distribution of trace elements in soils of the Dam River and Tuotuo River basins are demonstrated in this paper. By using contrasting methods. it is found that the content of trace elements of soi... Natural contents and distribution of trace elements in soils of the Dam River and Tuotuo River basins are demonstrated in this paper. By using contrasting methods. it is found that the content of trace elements of soil in the region is at the lower limit of the world's soil content level, that the tendency of the average trace element content in the four main types of soil is shown as: alpine mountain meadow soil>marsh soil>alpine mountain steppe soil> alpine mountain cryogenic soil. the average content of trace elements such as Cr. Co, Zn, Cu, Hg, Pb, Mo, Mn and Ni in the Dam River basin is higher than that of the Tuotuo River basin except that of the elements Ba and Sr. In addition. through correlation analysis. the relationship of intergrowth and association among soil elements are revealed. 展开更多
关键词 content of TRACE elements. distribution of TRACE elements TRACE element of SOILS DAM RIVER basin. Tuotuo RIVER BASIN
在线阅读 下载PDF
Contents of Trace Metal Elements in Cow Milk Impacted by Different Feedstuffs
2
作者 Song Ren-ju Tong Hui-li +1 位作者 Huang Jian-guo Gao Xue-jun 《Journal of Northeast Agricultural University(English Edition)》 CAS 2015年第3期54-61,共8页
Feedstuff intake plays key role in impacting the yield and quality of milk. In this study, we discussed the contents of trace metal elements in cow milk impacted by different feedstuffs. We detected the contents of Pb... Feedstuff intake plays key role in impacting the yield and quality of milk. In this study, we discussed the contents of trace metal elements in cow milk impacted by different feedstuffs. We detected the contents of Pb, Cd, As, Cu, Mg, Ca, Fe and Zn in different feedstuffs and milk by atomic absorption spectrophotometry. The determinations of Pb, Cd and As contents were by graphite furnace A_AS and Cu, Mg, Ca, Fe and Zn was by flame atomic absorption spectrometry. The results showed that Pb, Cd, As and Cu presented in feedstuffs, but Pb, Cd and As were lowly detected in milk samples, and Cu was not detected in milk samples. The content of Mg in concentrates was lower than that in forages. However, the content of Mg in milk from concentrate feed was higher than that in forage feed. This suggested that the utilization of Mg in concentrate feed was higher than that in forage feed. The contents of Ca and Zn were opposite to Mg, and the utilization of Ca and Zn in forage feed was higher than that in concentrate feed. There was no obviously change law of Fe in different feedstuffs and milk samples. The relationship between the contents of trace metal elements in milk to feedstuffs would provide a theoretical basis for dairy farming. It would be useful for improving the milk yield and milk quality of dairy production. 展开更多
关键词 feedstuff cow milk trace metal element content
在线阅读 下载PDF
Effect of phase content on deformation compatibility in ferrite and bainite dual-phase steel: experimental and crystal plasticity finite element analysis
3
作者 Xian-bo Shi Xing-yang Tu +3 位作者 Bing-chuan Yan Yi Ren Wei Yan Yi-yin Shan 《Journal of Iron and Steel Research International》 2025年第3期743-755,共13页
The phase volume fraction has an important role in the match of the strength and plasticity of dual phase steel.The different bainite contents(18–53 vol.%)in polygonal ferrite and bainite(PF+B)dual phase steel were o... The phase volume fraction has an important role in the match of the strength and plasticity of dual phase steel.The different bainite contents(18–53 vol.%)in polygonal ferrite and bainite(PF+B)dual phase steel were obtained by controlling the relaxation finish temperature during the rolling process.The effect of bainite volume fraction on the tensile deformability was systematically investigated via experiments and crystal plasticity finite element model(CPFEM)simulation.The experimental results showed that the steel showed optimal strain hardenability and strength–plasticity matching when the bainite reached 35%.The 3D-CPFEM models with the same grain size and texture characters were established to clarify the influence of stress/strain distribution on PF+B dual phase steel with different bainite contents.The simulation results indicated that an appropriate increase in the bainite content(18%–35%)did not affect the interphase strain difference,but increased the stress distribution in both phases,as a result of enhancing the coordinated deformability of two phases and improving the strength–plasticity matching.When the bainite content increased to 53%,the stress/strain difference between the two phases was greatly increased,and plastic damage between the two phases was caused by the reduction of the coordinated deformability. 展开更多
关键词 Polygonal ferrite and bainite dual phase steel Phase content Deformation compatibility Crystal plasticity finite element simulation Stress/strain difference
原文传递
Available Contents of Trace Nutrient Element and Factors Affecting Their Availability in Western Jilin 被引量:5
4
作者 施宪 王冬艳 +2 位作者 李月芬 靳克 郭珍 《Agricultural Science & Technology》 CAS 2010年第5期73-76,共4页
Based on the assay of the total content and available content of the trace nutrient elements and the soil pH and organic matter of the soil samples,the characteristic of the available content of the trace nutrient ele... Based on the assay of the total content and available content of the trace nutrient elements and the soil pH and organic matter of the soil samples,the characteristic of the available content of the trace nutrient elements and their affecting factors are studied. The results show that the available B in western Jilin is in a middle level,the content in Nong'an is higher than that in the others; the available Mn is extremely abundant; the available Cu in Nong'an is obviously higher than other areas,and the content in Da'an differs greatly; the available Zn is in a middle level; the severe shortage of available Mo differs between different areas; and the available Fe is extremely abundant. The available Mn,Cu and Fe have significantly positive correlation with their total content; the available B has significantly positive correlation with pH,and Zn has obviously negative correlation with pH; the available Mn and Fe had significantly positive correlation with soil organic matter. 展开更多
关键词 Trace nutrient element Available content The affecting factors Western Jilin
在线阅读 下载PDF
Study on the Major and Trace Elements in Soil of Yunnan Farmland
5
作者 徐娟 刘刚 +3 位作者 赵兴祥 赵帅群 任静 胡建飞 《Agricultural Science & Technology》 CAS 2014年第12期2141-2144,共4页
In order to investigate the distribution of soil available micronutrients, and provide a theoretical basis for management of fertilizing reasonably on crops, the contents of major and trace elements (P, K, Ca, Mg, Cu... In order to investigate the distribution of soil available micronutrients, and provide a theoretical basis for management of fertilizing reasonably on crops, the contents of major and trace elements (P, K, Ca, Mg, Cu, Fe, Zn, and Mn) in farm- land soil collected from Yunnan Province were determined by inductively coupled plasma-mass spectrometry (ICP-MS), the contents and distribution of major and trace elements were also studied. The results showed that the contents of available P, K were balance, available Ca, Mg were deficient, and available Cu, Fe, Zn, Mn were very plentiful. Major and trace elements distribution of different landform areas were obviously different. The contents of trace elements (Fe, Zn and Mn) of central Yunnan Red Plateau were significantly higher than those of Hengduan Mountains in western Yunnan and those of karst plateau in eastern Yunnan. The contents of available P, K, and Ca gradually declined from west to east, while the content of available Cu rose gradually from west to east. The results are reference value to elements determination and agricultural production in farmland soils. 展开更多
关键词 ICP-MS Soil of Yunnan farmland Major elements Trace elements content
在线阅读 下载PDF
Correlation Between Chemical Element Contents in Tree Rings and Soils 被引量:7
6
作者 QIANJUN-LONG KESHAN-ZHE 《Pedosphere》 SCIE CAS CSCD 1993年第4期309-319,共11页
The annual growth rings of ten trees and the soils near the tree roots were sampled from the mining area of lead-and zinc-dominant metals in the Xixia Mountain, Nanjing, for the determination of chemical element conte... The annual growth rings of ten trees and the soils near the tree roots were sampled from the mining area of lead-and zinc-dominant metals in the Xixia Mountain, Nanjing, for the determination of chemical element contents. The study results showed that the elemental contents in the tree rings were correlated with those in the soils, i. e., the elemental contents in the tree rings increased with those in the soils, even in the cases of different environments and different tree species. Therefore, a time-concentration sequence could be set up on the basis of determining the elemental contents in the successive annual growth rings of trees to qualitatively reflect the annual variations of relevant elements in the soils, and a time-concentration sequence of elemental contents in soils could also be established in terms of related model to reproduce the dynamic changes of the surroundings. 展开更多
关键词 CORRELATION elemental contents SOILS tree rings
在线阅读 下载PDF
Chrono-Sequences of Elemental Contents in Tree Ringsand Soils 被引量:3
7
作者 QIANJUN-LONG KESHAN-ZHE 《Pedosphere》 SCIE CAS CSCD 1994年第1期27-33,共7页
There exists a logarithmic linear correlation, i. e., In C'(Z, t) = a(Z) + b(Z) ln(Z, t) where Z is the atomicnumber of element and t the year when tree ring grows between the chemical element contents in tree rin... There exists a logarithmic linear correlation, i. e., In C'(Z, t) = a(Z) + b(Z) ln(Z, t) where Z is the atomicnumber of element and t the year when tree ring grows between the chemical element contents in tree ringsC(Z, t) and those in the soils near the tree roots C'(Z, t).By determining the elemental contents of the annual growth rings of trees, we could establish the chrono-sequences of elemental contents in the tree rings, thus calculating that of the soil, that is, reproducing thedynamic changes of contents of elements in the soil C'(Z, t). The background values of elements in the soilunder site conditions of the tree could be estimated from the minimum C(Z, t_0) in the chrono-sequences ofelemental contents in the tree rings. 展开更多
关键词 background value chroncasequences elemental contents SOILS tree rings
在线阅读 下载PDF
Characteristics of mineral element content of alpine vegetation in permafrost region on Qinghai-Tibetan Plateau 被引量:2
8
作者 ZhaoPing Yang JiXi Gao +1 位作者 Hua OuYang Hui Tan 《Research in Cold and Arid Regions》 2012年第1期34-39,共6页
The content characteristics of 16 elements (Al, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Sr, and Zn) in 23 plant species collected from the Qinghai-Tibetan Plateau permafrost region were investigated using ... The content characteristics of 16 elements (Al, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Sr, and Zn) in 23 plant species collected from the Qinghai-Tibetan Plateau permafrost region were investigated using ICP-OES. Results show that the average contents of Ca, K, Mg, Fe and P were higher than 1,000 mg/kg, those of Al, Na, Zn and Cr ranged between 10-1,000 mg/kg and those of Cu, Li, Pb and Mo were less than 10 mg/kg. The levels of Al, Ca, K, Mg and Na were within the scope of the reported terrestrial plant element content, those of Sr, Fe and Cr were higher than the average of the terrestrial plants and the maximum content of Max was higher than the upper limit of the reported Mn content. The main character of the element content was of the Ca〉K type, however, in terms of Cyperaeeae species the element content character was K〉Ca type. The contents of Ca, Li, Mg and Sr in Gramineae and Cyperaeeae species were higher than those in other species and the contents of Ca, K, Mg, Fe, E A1 and Na in all collected plants were higher than those of other elements. Zn had weak variability with the lowest coefficient (i.e., 7.81%), while other elements had strong variability. The ratio of maximum content to minimum content indicated Ca and K had less change than other elements in the Qinghai-Tibetan Plateau permafrost region. Element content of alpine vegetation in the Qinghai-Tibetan Plateau permafrost region mainly shows a positive correlation, among which the correlation coefficient between Al and Pb, Al and Fe, Mo and Cr, Pb and Fe, Sr and Li were higher than 0.9, and negative correlation had no statistical signifi- cance. The correlation between Al and Fe, Mg, Mn in the Qinghai-Tibetan Plateau permafrost region were consistent with that reported in Kunlun Mountains. 展开更多
关键词 element content PERMAFROST Qinghai-Tibetan Plateau ICP-OES
在线阅读 下载PDF
Angular Distribution of Element Contents in Tree Rings and the Environmental Information 被引量:2
9
作者 KE SHANZHE LIU ZHENGRONG +1 位作者 QIAN JUNLONG CHEN RUSONGI and KE XIAOKANG (Physics Department, Nanjing University, Nanjing 210095,China)(Nanjing Institute of Geogmphy and Limnology, the Chinese Academy of Sciences, Nanjing 210008, China)(Garded and Greenbelt 《Pedosphere》 SCIE CAS CSCD 1999年第1期69-76,共8页
Element contents of tree rings and soils near tree roots collected from Deodar cedar (Cedrus deodara (Roxb.) G. Don) and Masson pine (Picks massoniana lamb.) were determined to study the relationship between the angul... Element contents of tree rings and soils near tree roots collected from Deodar cedar (Cedrus deodara (Roxb.) G. Don) and Masson pine (Picks massoniana lamb.) were determined to study the relationship between the angular distribution of element contents in tree rings and the environmental information. The chemical composition and properties of soils are very much complicated, which leads to the non-uniform distribution of the element contents in tree rings. The statistical multi-variable regression method was used to got the information of the tree-centered distribution of element contents in the environment (soil) (C’), C’(z, θj ), from the distribution of element contents in tree rings (C), C(Z, θi), which depends on the plane azimuth angle (θi), i. e., C=C(Z,θi), where Z is the atomic number of the element, with a satisfactory result,though this study is only a primary one. 展开更多
关键词 angular distribution element contents environmental information tree rings
在线阅读 下载PDF
Morphologic characters and element content during development of Pinus tabuliformis seeds 被引量:1
10
作者 Hui Li Jian Zhao +2 位作者 Chen Zhou Scott A.Merkle Jin-Feng Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2016年第1期67-74,共8页
An embryo classification system for Pinus tabuliformis Carr. was established by time-tracing sam- pling and observation of zygotic embryos. The zygotic embryos were divided into nine stages. Key elements of the zygoti... An embryo classification system for Pinus tabuliformis Carr. was established by time-tracing sam- pling and observation of zygotic embryos. The zygotic embryos were divided into nine stages. Key elements of the zygotic embryo and female gametophyte (FG) tissue of P. tabuliformis were analyzed, using inductively coupled plasma-emission spectroscopy. Several elements--includ- ing aluminum, iron, sodium, and copper--are found in both embryo and FG tissue. Boron, phosphorus, magnesium,zinc, and calcium are also required for zygotic embryo development and therefore accumulated. Manganese is selectively excluded from the embryo. The zygotic embryo development needs a low-sodium and high-potassium nutrition proportion. The results of elemental analysis from zygotic embryos and FGs can provide the mineral targets for optimizing the formulation of culture medium for somatic embryogenesis. 展开更多
关键词 Embryo classification system Zygoticembryo Female gametophyte element content analysis
在线阅读 下载PDF
ELEMENTAL CONTENTS IN ORGANS AND TISSUES OF CHINESE ADULT MEN 被引量:1
11
作者 Hong-da Zhu Jing-yu Wang +8 位作者 Quan Wu Nei-fen Wang Ti-jiang Fan Hu-sheng Liu Qing-fen Liu Xiao-yan Wang Li Ou-yang Ya-qiong Liu Qing Xie 《Chinese Medical Sciences Journal》 CAS CSCD 2007年第2期71-82,共12页
Objective To provide basis of reference values for relevant parameters of Chinese Reference Man. Methods Eighteen kinds of major organ or tissue samples, including muscle, rib, liver, and so on, were obtained from 4 a... Objective To provide basis of reference values for relevant parameters of Chinese Reference Man. Methods Eighteen kinds of major organ or tissue samples, including muscle, rib, liver, and so on, were obtained from 4 areas (Hebei, Shanxi, Jiangsu, and Sichuan provinces) with different dietary patterns in China in autopsy of 16 healthy adult men, who had just encountered sudden deaths. At the same time, whole blood samples were collected from 10 volunteers living in each of these areas. The concentrations of 56 elements in these samples were detected by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), and Graphite Furnace Atomic Absorption Spectrometry (GF-AAS) techniques. Based on obtained concentrations and reference values of these organ or tissue weights for Chinese Reference Man, the relative elemental burdens in these organs or tissues as well whole body were also estimated. Results The concentrations of 56 elements in 18 main organs or tissues were determined all together and their elemental organ or tissue and whole body burdens were estimated. Furthermore, the distributions of important elements for radiation protection in these organs or tissues were emphatically discussed. Conclusion By summing with past related results, the total results obtained from the series of research may provide more reliable and better representative basis of these reference values for Chinese Reference Man than before. 展开更多
关键词 Chinese adult man elemental content ORGAN tissue whole body BURDEN
在线阅读 下载PDF
Macro-and Microelement Contents of Fruiting Bodies of Wild-Edible Mushrooms Growing in the East Black Sea Region of Turkey 被引量:4
12
作者 Faik A.Ayaz Hülya Torun +3 位作者 Ahmet Colak Ertugrul Sesli Mark Millson Robert H.Glew 《Food and Nutrition Sciences》 2011年第2期53-59,共7页
Eleven different wild-edible mushroom species growing in the Black Sea region of Turkey were analysed for their metal content. Specimens of mushrooms were gathered in Trabzon, Giresun and Ordu and analyzed for 31 mine... Eleven different wild-edible mushroom species growing in the Black Sea region of Turkey were analysed for their metal content. Specimens of mushrooms were gathered in Trabzon, Giresun and Ordu and analyzed for 31 minerals, four of which (Be, Sb, Te and Ti) were not detected. Whereas some minerals including Ag, As, Cd, La, Mo, Pb, Se, Y and Zr were detected in just a few mushroom species, another 18 minerals were found in all 11 species. All metal concentrations were expressed on a dry weight basis (d.w.). With regard to nutritionally important amounts of essential and trace minerals, the metal content (μg/g d.w.) of mushroom samples ranged from 21,800-39,800 for K, 2590-14,000 for P, 268-1600 for Ca, 561-1210 for Mg, 74-829 for Fe, 11.2-321 for Cu, 36.2-241 for Zn, 14.1-76.5 for Mn and 0.13-2.85 for Co. Small amounts of toxic metals such as As, Cd and Pb were found in all 11 mushroom species. L. laccata contained a large amount of As (145 μg/g d.w.). These results show that the investigated mushrooms can be a useful component for human diets because of their high content of many essential minerals and trace elements and low content of toxic metals. 展开更多
关键词 Wild-edible Mushrooms Mineral content Toxic Metals Trace elements TURKEY
暂未订购
Prediction of ash content of unloaded coal based on a discrete element simulation
13
作者 Deng Jianjun Zhuo Jinwu Shi Hongxia 《International Journal of Mining Science and Technology》 SCIE EI 2013年第5期647-651,共5页
Based on analysis of regularity of stacking coal,discrete element simultaneous simulation is adopted to predict the process of unloading coal,which is proved to be effcient in the prediction of ash content.The results... Based on analysis of regularity of stacking coal,discrete element simultaneous simulation is adopted to predict the process of unloading coal,which is proved to be effcient in the prediction of ash content.The results show that the altitude of new irregular coal is equal to the income coal volume divided by area of cabin.The distribution of infnitesimal flow velocity helps to induce the motion equation of infnitesimal element,which provides the mathematical model for computer simulation.Swarm,a computer programming language,is utilized in this study.Adaptive infnitesimal stacking algorithm helps settle the diffculties in attainment of infnitesimal elements.The result of simulation is similar to the actual situation,which can accurately predict the ash contents of current time and cumulative time.Coal movement in the cabin is a new project,the result of which can also be applied to other solid particles and the widespread of the result will be highly valued. 展开更多
关键词 Discrete element SIMULATION Ash content forecast Coal blending Motion equation Mathematical model
在线阅读 下载PDF
Prediction of Chemical Element Contents in Soils
14
作者 KESHAN-ZHE QIANJUN-LONG 《Pedosphere》 SCIE CAS CSCD 1994年第2期105-117,共13页
Assuming that the regularity for the dynamic changes of the chrono-sequences of chemical element contents intree rings follows a k-order constant coefficient differential equation and substituting the differential wit... Assuming that the regularity for the dynamic changes of the chrono-sequences of chemical element contents intree rings follows a k-order constant coefficient differential equation and substituting the differential with the differ-ence, we could obtain the inferred value y_(m+k+1) by the formula: Each coefficient c_i in the formula may be ascertained by use of the measured data in the chrono-sequences. Ex-tending the chrono-sequences on the assumption that the regularity of dynamic changes wouldn't change in the nearfuture, the contents of chemical elements in the soils may be predicted in termis of a logarithmic linear correlationmodel. Also, this extension method could be used for the reproduction of the contents of chemical elements in soilsduring different periods of time in the past. 展开更多
关键词 Chrono-sequences of elemental contents EXTENSION PREDICTION SOILS tree rings
在线阅读 下载PDF
Using Prostatic Fluid Levels of Some Trace Elements and Their Combinations in Non-Invasive and Highly Accurate Screening for Prostate Cancer
15
作者 Vladimir Zaichick 《Journal of Cancer Therapy》 2020年第1期1-17,共17页
Objective: Prostate specific antigen (PSA) does not provide the high reliability and precision that is required for an accurate screening for prostate cancer?(PCa). The aim of our study was to search for a simple, rap... Objective: Prostate specific antigen (PSA) does not provide the high reliability and precision that is required for an accurate screening for prostate cancer?(PCa). The aim of our study was to search for a simple, rapid, direct, preferably non-invasive, and highly accurate biomarker and procedure for the screening for PCa. Method: The levels of trace elements (TE) Br, Fe, Rb, Sr,?and Zn were prospectively evaluated in expressed prostatic fluid (EPF). Also?Zn/Br, Zn/Fe, Zn/Rb, Zn/Sr concentration ratios as well as ZnRb and (ZnRb)/Fe concentration combinations were calculated for EPF samples, obtained from 38 apparently healthy males and from 33, 51, and 24 patients with chronic prostatitis, benign prostatic hyperplasia, and PCa, respectively. Measurements were performed using an energy dispersive X-ray fluorescent (EDXRF) microanalysis. Results: It was found that in the EPF of cancerous prostates the levels of Rb, Zn, Zn/Br, Zn/Fe, Zn/Sr, ZnRb, and (ZnRb)/Fe were significantly lower in comparison with those in the EPF of normal, inflamed, and hyperplastic prostates. For example, in comparison hyperplastic?with cancerous prostates p values obtained using Student’s t-test and?Wilcoxon-Mann-Whitney U-test were Conclusions: The levels of TE and their combinations in EPF, obtained by EDXRF, is a fast, reliable, andnon-invasive diagnostic tool that can be successfully used by local, non- urologist physicians at the point-of-care to provide a highly effective PCa screening and as an additional confirmatory test before a prostate gland biopsy. 展开更多
关键词 UROLOGY Screening Prostate Cancer EXPRESSED PROSTATIC Fluid Trace element content Energy-Dispersive X-Ray Fluorescent Analysis
暂未订购
Comparison of 66 chemical element contents in normal and benign hyperplastic prostate
16
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
暂未订购
Variations of nutrient element contents of plants and soils in the process of karst rocky desertification 被引量:1
17
作者 Liping XIE Shijie WANG 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期176-176,共1页
关键词 喀斯特 土壤 植物 生态系统 营养元素
在线阅读 下载PDF
Effect of iron content on microstructures and mechanical properties of new ultra-high strength Al−Zn−Mg−Cu alloys
18
作者 Xin-yuan XU Lei JIANG +2 位作者 Xin-biao ZHANG Ming-hong MAO Jian-xin XIE 《Transactions of Nonferrous Metals Society of China》 2025年第10期3179-3190,共12页
The impact of Fe content on the microstructures and mechanical properties of an ultra-high strength aluminum alloy,namely,Al−10.50Zn−2.35Mg−1.25Cu−0.12Cr−0.1Mn−0.1Zr−0.1Ti,was investigated.It is found that the increas... The impact of Fe content on the microstructures and mechanical properties of an ultra-high strength aluminum alloy,namely,Al−10.50Zn−2.35Mg−1.25Cu−0.12Cr−0.1Mn−0.1Zr−0.1Ti,was investigated.It is found that the increase of Fe content leads to a notable rise in the volume fraction of microscale secondary phases,including(Cu,Fe,Mn,Cr)Al_(7),σphase(composed of Al,Zn,Mg,and Cu elements),and Al_(3)(Zr,Ti).The formation of these secondary phases results in the depletion of certain phase-forming elements,thereby significantly reducing the quantity of strengthening phases.Fe imposes minimal impact on tensile strength,but it can significantly alter the elongation(δ).For instance,the average elongation of the alloy with 0.18 wt.%Fe(δ=4.5%)is less than half that of the alloy with Fe less than 0.1 wt.%(δ=9.9%−10.9%).The reduction in elongation is attributed to the combined effects of the formation of coarse secondary phases and the diminished quantity of strengthening phases around these coarse phases. 展开更多
关键词 Al−Zn−Mg−Cu alloy tensile property element distribution secondary phase Fe content
在线阅读 下载PDF
8种石斛属植物营养价值比较分析与评价
19
作者 杨哲 陈妮 +7 位作者 彭丽辉 江海都 隆丽梅 蒋强 韦宇静 熊忠臣 韦霄 柴胜丰 《食品工业科技》 北大核心 2026年第2期308-318,共11页
大部分石斛属植物为传统药食两用植物,具有很高的营养价值,了解不同石斛种类营养价值的差异,可为其开发利用提供理论依据。本研究对梳唇石斛(D.strongylanthum)、束花石斛(D.chrysanthum)、鼓槌石斛(D.chrysotoxum)、喇叭唇石斛(D.litui... 大部分石斛属植物为传统药食两用植物,具有很高的营养价值,了解不同石斛种类营养价值的差异,可为其开发利用提供理论依据。本研究对梳唇石斛(D.strongylanthum)、束花石斛(D.chrysanthum)、鼓槌石斛(D.chrysotoxum)、喇叭唇石斛(D.lituiflorum)、滇桂石斛(D.scoriarum)、钩状石斛(D.aduncum)、重唇石斛(D.hercoglossum)和罗河石斛(D.lohohense)8种石斛属植物的一般营养成分、矿物质元素、药效成分及氨基酸组成与含量进行了测定和分析,并对其营养价值进行综合评价。结果显示:8种石斛均表现出低脂肪(含量范围0.98%~1.74%)的营养特点,且富含Mg(1.03×10^(3)~6.06×10^(3) mg/kg)、K(0.39×10^(4)~1.66×10^(4)mg/kg)、Ca(0.3×10^(4)~2.33×10^(4)mg/kg)等多种矿物质元素。梳唇石斛与喇叭唇石斛的多糖含量较高(分别为51.11%和38.91%);除钩状石斛外,其余石斛种类的醇溶性浸出物含量均高于6.5%。8种石斛氨基酸种类齐全,氨基酸总量介于1.395%~3.883%,必需氨基酸总含量质量分数介于36.00%~41.12%,表明它们是优质的氨基酸来源。氨基酸总量与必需氨基酸(r=0.92,P<0.01)、药用氨基酸呈极显著正相关(r=0.89,P<0.01);与氨基酸评分显著相关(r=0.68,P<0.05),但与药效成分无显著相关性(P>0.05)。聚类分析显示,同组内不同石斛营养成分亦存在较大差异性。8种石斛分为Ⅲ大类,其中梳唇石斛与喇叭唇石斛具有较高的品质被归为Ⅰ类,其不仅在多糖含量上表现优异,氨基酸总量(3.041%和3.530%)亦较高,可作为优先选育和利用的优质石斛资源。 展开更多
关键词 石斛属 营养成分 矿物质元素 氨基酸含量 营养评价
在线阅读 下载PDF
ABC转运蛋白OsARG1调控水稻抽穗期的功能
20
作者 王忠妮 雷月 +2 位作者 李佳丽 宫彦龙 朱速松 《中国农业科学》 北大核心 2026年第1期1-16,共16页
【目的】抽穗期是影响水稻产量和品质的重要农艺性状。水稻抽穗期受组蛋白修饰酶、转录因子、蛋白激酶、成花素及光敏色素等的调控。ABC转运蛋白在底物运输过程中发挥重要作用,但其在抽穗期调控中的功能尚不清楚。研究水稻ABC转运蛋白Os... 【目的】抽穗期是影响水稻产量和品质的重要农艺性状。水稻抽穗期受组蛋白修饰酶、转录因子、蛋白激酶、成花素及光敏色素等的调控。ABC转运蛋白在底物运输过程中发挥重要作用,但其在抽穗期调控中的功能尚不清楚。研究水稻ABC转运蛋白OsARG1在抽穗期调控中的功能,可为丰富抽穗期调控网络提供依据。【方法】以日本晴(野生型)和osarg1突变体为试验材料,对抽穗期、株高、分蘖数、穗长等农艺性状进行调查统计。测定日本晴叶片(WT),以及osarg1突变体的白化叶(WL)、黄绿叶(YL)和绿色叶(GL)中的叶绿素含量;通过ICP-MS测定上述材料中钴、镍、钙、镁、铁等金属元素的含量。对日本晴及osarg1的WL和GL进行激素含量测定和转录组测序分析;通过激素-转录组联合分析进一步研究OsARG1调控水稻抽穗期的作用机理。【结果】osarg1在贵阳和长春的抽穗期均提前,株高、分蘖数和穗长等农艺性状指标均低于野生型。叶绿素含量测定结果表明,YL和WL中的叶绿素含量显著低于野生型;金属元素含量测定发现osarg1的WL、YL和GL中的金属元素平衡均受到破坏。激素含量测定结果显示,YL和WL中的赤霉素、部分生长素类激素和细胞分裂素类激素的含量上调,且在WL中的上调幅度更大。转录组测序数据显示,GL_vs_WT和WL_vs_WT 2个组别分别鉴定出2001和6555个差异表达基因(DEGs)。经转录组数据分析,GL中20多个抽穗期相关基因的表达发生变化,包括甲基转移酶基因、成花素Hd3a和成花转变相关基因OsMADS14等。对GL_vs_WT的DEGs进行GO和KEGG富集分析,结果显示,DEGs在代谢过程、生长发育及对环境的响应等通路中富集。激素含量和转录组联合分析结果表明,OsARG1可能通过影响二萜合成途径、玉米素合成途径和激素信号传导调控赤霉素和细胞分裂素的含量。qRT-PCR结果显示,所选基因的表达变化趋势与转录组数据一致,证实转录组数据的准确性。【结论】osarg1的抽穗期提前,OsARG1可能通过影响抽穗期相关基因的表达,调控水稻抽穗期。同时,OsARG1还参与调控叶片中的叶绿素含量及镍、铁、镁等多种元素的含量。 展开更多
关键词 水稻 抽穗期 OsARG1 金属元素含量 植物激素 转录组测序
在线阅读 下载PDF
上一页 1 2 103 下一页 到第
使用帮助 返回顶部