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1.
采用电感耦合等离子体原子发射光谱仪分析测定了茵陈,蒲公英等8种野菜中FeMn,Cu、Zn、Ba、Sr、Cr、Mo,Co,Ni,Cd等11种微量元素的含量,并用国家计量局的杨树叶作为标准物对测定方法进行了考核,测定值与标准值吻合。方法的回收率在90.1-107.3%。  相似文献   

2.
研究了淬火和回火温度对6Cr18Mo(440A)和9Cr18Mo(440C)钢组织和性能的影响,最后确定了性能可满足泵阀服役条件要求的热处理工艺.上述工作为用9Cr18Mo和6Cr18Mo代替GCr15和20CrMo制造抽油泵泵阀提供了科学的依据  相似文献   

3.
应用石墨炉原子吸收法测定了西安市214名健康人头发中Zn,Cu,Fe,Mn,Ph,Cd,Cr,Mo,Ni,Co,Se等11种微量元素的含量.测定结果用计算机进行统计检验,并对不同年龄、不同性别进行对比分析,对人体微量元素与环境的关系作了对比研究.提出西安市健康人头发中11种微量元素含量的参考值范围.  相似文献   

4.
对9Cr18Mo和GCr15两种钢的腐蚀、磨蚀和腐蚀疲劳行为进行了实验研究.结果表明,在质量分数为2%~5%硫酸,1%盐酸,40%硝酸,3.5%NaCl水溶液和蒸馏水中,9Cr18Mo的抗腐蚀性能优于GCr15;在含0.02%与5%沙量的沙浆中,9Cr18Mo的年磨蚀率低于GCr15的数值;在空气、蒸馏水和3.5%NaCl水溶液中,9Cr18Mo的疲劳裂纹扩展速率也低于GCr15.9Cr18Mo和GCr15在中性水溶液中疲劳裂纹扩展均表现为氢脆机制.  相似文献   

5.
云南17种菊科植物微量元素含量特征研究   总被引:6,自引:0,他引:6  
本文论述了云南17种菊科植物9个元素含量的特征.元素含量顺序有10种植物遵守Fe,Al>Zn>Mn>Cu>Pb>Cr>Ni>Mo的规律,有5种植物遵守Fe,Al>Mn>Zn>Cr>Ni>Mo的规律.元素含量的相对离散度为:Al>Fe>Mo>Ni>Mn>Pb>Cu>Zn>Cr.反映元素含量顺序与相对离散度顺序不完全匹配.元素Cu,Mn,Pb,Cr,Mo,Zn含量的频数分布总体为正态.Fe,Ni,Al含量的频数分布为正偏态型,并呈现高狭峰.元素Al,Fe,Mn,Ni含量间呈明显正相关;Fe与Cu,Zn,Mo,Cr间呈负相关.根据统计分级聚类分析,17种植物分5组,1,2组共11种植物,显示了植物对Cu,Fe,Pb,Ni,Cr吸收积累的聚类特征.第5组的小一支箭和臭灵丹,显示出对Fe,Al或Ni,Cu,Pb吸收积累的特殊性  相似文献   

6.
研究了淬火和回火温度对6Cr18Mo和9Cr18Mo钢组织和性能的影响,最后确定了性能可满足泵阀服役条件要求的热处理工艺。上述工作为用9Cr18Mo和6Cr18Mo代替GCr15和20CrMo制造抽油泵泵阀提供了科学的依据。  相似文献   

7.
1673K下,采用-MoCr+Cr2O3ZrO2(MgO){Cu+Cr}aloy+(Cr2O3)slagMo+固体电解质电池测定了BaOBaF2Cr2O3渣系中Cr2O3的活度.研究结果表明,Cr2O3的活度随其浓度升高而升高,随XBaO/XBaF2升高而降低.根据实验及X射线衍射结果推测了该渣系的等温相图,并作出了该渣系中Cr2O3的等活度图.  相似文献   

8.
对126例脑血栓形成患者用精制蝮蛇抗栓酶(Svate-3)治疗,检测用药前后头发中Cr、Mn、Se、Mo、Co元素含量。发现脑血检患者用Svate-3治疗后发Cr、Mn、Se含量明显高于用药前,它们之间都有显著性差异,P<0.01;Mo、Co元素的含量在用药前后无显著性差异P>0.05,提示发Cr、Mn、Se与脑血栓有关。  相似文献   

9.
TiN涂层可显著提高零件寿命.研究TiN涂层的滑动磨损行为有重要意义.研究结果表明,表面进行TiN涂层后,Cr12MoV和LM1两种材料的磨损抗力大幅度提高;与TiN涂层试样相配对的40Cr试样的失重明显高于与没有涂层试样相配对的40Cr试样的失重;Cr12MoV和LM1两种材料及其经过TiN涂层后的磨损抗力相差不大.讨论了TiN涂层对基体材料的要求.  相似文献   

10.
蝉花的化学成分分析   总被引:4,自引:0,他引:4  
本文对麦角菌科真菌大蝉草CordycepscicadeShing测定了蛋白质、氨基酸、多糖、微量元素、脂肪等的含量,结果显示蝉花含蛋白质总量为39.35%,含有16种氨基酸,多糖含量为4.44%,脂肪含量为6.97%,并含有Cu、Mn、Zn、Cd、Pb、Ca、Fe、Mg、Cr、Co等元素.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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