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1.
本文制备了以苯胺和乙二醇为原料合成吲哚的一系列铜基催化剂,筛选出了高效催化剂Cu—Zn—Mn/SiO2,并对它们进行了ICP—AES和XRD表征。实验表明,由浸渍法制备的Cu—Zn—Mn/SiO2催化剂,稳定性、活性高于由共沉淀法制备的Cu—Zn—Mn/SiO。催化剂,吲哚收率76.0%。锰对铜和锌有明显的分散作用;铜晶拉越小,活性越高。  相似文献   

2.
铜或锌胁迫对小麦根中抗氧化系统的影响   总被引:1,自引:0,他引:1  
为探讨小麦根中抗氧化酶对重金属胁迫的反应.利用水培法研究了铜(Cu)或锌(Zn)胁迫对小麦幼苗根中活性氧(ROS)产生及抗氧化酶活性的影响.结果显示,Cu或Zn胁迫下小麦根中OH~·、H_2O_2和MDA含量均有不同程度的增加,Cu胁迫下O_2~(·-)含量呈先升高后下降的趋势,而O_2~(·-)在Zn胁迫下呈升高的趋势.Cu胁迫下超氧化物歧化酶(SOD)活性呈升高的趋势,而过氧化物酶(POD)活性呈先升高后下降的趋势.Zn胁迫下SOD活性呈先降低后升高的趋势,POD活性受到明显的抑制,过氧化氢酶CAT活性在Cu或Zn胁迫下均有不同程度的下降.表明Cu或Zn胁迫下小麦根中抗氧化酶活性发生了不同的变化,以此来清除根中积累的ROS,降低重金属对小麦的损伤.  相似文献   

3.
探讨有氧运动对2型糖尿病大鼠肾脏微量元素、SOD、MDA的影响及其相关性.40只雄性Wistar大鼠,以高脂高糖饲料喂养28 d,从中随机选取10只为对照组(NC,n=10),其余大鼠腹腔注射STZ诱导2型糖尿病,后随机分为2组:糖尿病对照组(DM,n=8)、糖尿病运动组(DS,n=8).DS组大鼠以25 m·min~(-1),30 min·d~(-1)和6 d·(7 d)~(-1)下持续运动56 d.实验末,测试肾脏组织SOD活性及MDA和微量元素Fe,Zn,Cu,Mn,Cr的含量.结果表明,与NC组比较,DM组大鼠Fe,Zn,Mn,Cr含量及SOD活性极显著降低(P0.01),Cu及MDA含量极显著升高(P0.01);与DM组相比,DS组Fe,Zn,Mn,Cr及MDA含量显著下降(P0.05),SOD活性显著升高(P0.05),Cu含量极显著降低(P0.01).SOD活性与Zn,Cr呈正相关(P0.05),与Mn呈显著性正相关(P0.01);MDA含量与Zn呈负相关(P0.05),与Cu呈正相关(P0.05).结果暗示,有氧运动通过纠正微量元素Zn,Cu,Mn,Cr代谢紊乱,显著提高2型糖尿病大鼠肾脏抗氧化水平,从而减低血糖,改善机体糖代谢.  相似文献   

4.
日光温室甜樱桃叶片中矿质营养元素含量的动态变化   总被引:5,自引:0,他引:5  
以红灯(Prunus L.)品种为试材,研究了温室栽培樱桃叶片中7种矿质营养元素(Cu,Zn,Fe,Mn,Ca,Mg,K)含量的动态变化及其相关性.结果表明:开花期至果实成熟期,樱桃叶片中Cu,Zn含量显著下降;Fe,Mn,Ca,Mg,K含量显著增加.果实采后生长发育阶段,Fe元素含量极显著下降且略有回升,其他6种元素变化平缓(或增加或下降).Cu与Mn,Zn元素分别呈极显著负相关和正相关;Ca与Mn和Cu,Zn元素分别呈极显著正相关和负相关;K,Mg元素与Cu元素呈显著和极显著负相关,与Mn,Fe,Ca,Mg元素呈显著或极显著正相关.  相似文献   

5.
在杂交水稻威优 35、威优 49的抽穗期 ,从始穗起每隔 4天对其叶片SOD活性测定 1次 ,并测定其用氯仿 -乙醇抑制后的活性 ;用Cu2 +、Zn2 +混合液对大田进行喷施 ,从始穗第 16天开始 ,分析其Cu2 +、Zn2 +离子在大田栽培条件下对水稻叶片SOD活性的影响。试验结果表明 :氯仿 -乙醇能够抑制杂交水稻抽穗期SOD的部分活性 ,有可能在杂交水稻叶片中存在MnSOD ;抽穗期叶片喷施Cu2 +、Zn2 +混合液可提高SOD活性  相似文献   

6.
13种豆类种子超氧物歧化酶(SOD)活性,同工酶及热稳定性研究的结果表明,豆类种子含有较高的SOD活性,每克鲜重含500-1200酶单位,其中绿豆,赤豆,大豆种子SOD活性都在1000U/g以上,豆类种子一般含有Cu.Zn-SOD和Mn-SOD两种类型的同工酶,以前者为主,其中Mn-SOD活性一般占总活性的10%,粉青豆Mn-SOD活性最高,为198U/g,聚丙烯酰凝胶电泳(PAGE)同工酶谱显示多数受试种类含1条Mn-SOD区带和3-6条Cu.Zn-SOD区带。  相似文献   

7.
对广西南丹山口林场3种林龄(8、14和28年生)秃杉人工林的Fe、Mn、Cu、Zn和B等5种微量元素含量、积累量、年净积累量及其分配进行了研究。结果表明:秃杉各部分微量元素含量从大到小依次为树叶、干皮、树枝、树根、干材; 林木各组分微量元素含量以Mn或Fe最高,其次是Zn和B,Cu最低;8、14和28年生秃杉林分微量元素积累量为12755~46393kg/hm2,其中各乔木层微量元素积累量占总积累量分别为8784%、7896%和7681%,林下植被层的分别占239%、401%和547%,凋落物层的分别占977%、1703%和1772%;秃杉人工林不同组分微量元素积累量的分配随林分年龄的增长发生变化,由8年生和14年生以在树叶和树枝中为主,逐渐转移到28年生在以干材和树皮中为主,各微量元素积累量以Fe或Mn最高,其次是Zn和B,Cu最低;3种年龄林分微量元素年净积累量分别为1398、1420 和1.273kg/(hm2·a),同一组分各微量元素年净积累量与各组分微量元素积累量变化顺序一致,即为Mn或Fe较高,Zn次之,B和Cu较低。  相似文献   

8.
<正> 本文提出用空气-乙炔火焰原子吸收光谱法测定铝合金中的Mn、Mg、Cu和Zn,可使用不含基体铝的标准样品。测定时把样品溶于盐酸中並使盐酸浓度等于或低于1%。在含有2mg/ml La的情况下测定Mg和Mn。用La消除Al、Si、Ti和Cr对Mn和Mg的干扰。分析结果与标准值相一致。Cu、Zn、Mg和Mn的相对标准偏差为0.49—2%。本方法简单、快速、准确。  相似文献   

9.
花生大豆种子中SOD同工酶的研究   总被引:1,自引:0,他引:1  
花生、大豆种子中的SOD粗提液经聚丙烯酰胺凝胶电泳及NBT活性染色,结果表明,花生种子有6条SOD同工酶谱带,其中1条为Mn-SOD,其余为Cu,Zn-SOD.大豆种子有8条SOD同工酶谱带,其中3条为Mn-SOD,其余为Cu,Zn-SOD.不同pH值对SOD活性有一定的影响,pH=1.0时,Mn-SOD同工酶谱带消失;pH=12.0时,全部SOD同工酶谱带消失.变性剂DTT、SDS和β-巯基乙醇对SOD同工酶有较大影响,SDS使Mn-SOD谱带丢失,DTT、β-巯基乙醇使全部SOD同工酶谱带消失.  相似文献   

10.
铜、铅污染对翦股颖和高羊茅生理的影响   总被引:8,自引:1,他引:8  
研究了土壤中不同浓度Cu、Pb及其联合作用对翦股颖和高羊茅生理指标的影响.结果表明,土壤中的Cu、Pb污染使2种草的叶绿素浓度、光合作用均呈下降趋势.在一定浓度的Cu、Pb胁迫下,翦股颖中的SOD活性升高,但浓度过大时,SOD活性则下降.高羊茅在不同程度的Cu污染胁迫下,SOD活性呈先上升后下降的趋势,而在Pb、Pb和Cu复合污染作用条件下,SOD活性均呈下降趋势.  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.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
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   

19.
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   

20.
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   

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