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1.
采用离子色谱法 ,Shim -PackIC—A1阴离子柱 ,以 2 .5mmol/L邻苯二甲酸 + 2 .4mmol/L三 (羟甲基 )氨基甲烷为流动相 ,同时测定饮用水中氯化物、硝酸盐氮和硫酸盐的含量 ,回收率为 99%~ 10 2 % ,相对标准偏差均 <3 % ,最低检测限分别为 0 .0 10mg/L、0 .0 0 5mg/L、0 .0 2 0mg/L。实验证明 ,此方法快速、简便、准确、灵敏度高  相似文献   

2.
从安徽芜湖冶炼厂污染土壤中分离出数百菌株,对其中一株菌J101进行了耐盐耐碱性能、重金属、抗生素抗性研究.J101菌株为一球菌,经初步生理生化鉴定为葡萄球菌属(Staphylococcus sp.),能够在液体细菌培养基中耐NaCl高达20%、耐碱高达pH10;在含6mmol/L Cd2 ,30mmol/L Pb2 、4mmol/L Zn2 、2mmol/L Cu2 、6mmol/L Ni2 、16mmol/L Mn2 和4mmol/L Cr6 细菌琼脂培养基上能够生长.J101菌株能够抗多种抗生素,可生长在Amp 400mg/L, Kan 30mg/L, Str 80mg/L, Rif 100mg/L琼脂培养基上.阳离子Zn2 存在时进入菌体中的Cd2 明显减少,活菌体J101能够吸附83.73% Cd2 .  相似文献   

3.
采用胶束电动色谱-质谱联用法同时测定心脑康胶囊中的芍药苷、葛根素、大黄素含量。该方法以未涂层石英毛细管(80cm×50μm)为分离通道,以30 mmol/L月桂酸-90 mmol/L氨水(pH值9.0)为缓冲溶液,50%异丙醇(含1 mmol/L乙酸)为鞘液,工作电压为25kV。测定结果:各组分在18 min内达到完全分离,芍药苷、葛根素、大黄素的线性范围分别为0.20~200mg/L、0.50~500mg/L、0.020~300 mg/L,检出限分别为0.020mg/L、0.050mg/L、0.0060 mg/L。样品的加标回收率在96.5%~102%之间,相对标准偏差均小于3.1%。该方法简便、快速、准确可靠,已成功应用于心脑康胶囊中芍药苷、葛根素、大黄素的含量测定。  相似文献   

4.
目的 :研制一种基于钴卟啉和Nafion的葡萄糖电极 .方法 :用序贯淘汰水平法对该电极膜组成进行优化 .结果 :其优化后电极的最佳膜组成为 :1.0mmol/L钴卟啉 [5 ,10 ,15 ,2 0 -tetrakis (4-methoxy -phenyl) - 2 1H ,2 3H -porphinecobalt](TMPPCo)溶液为 15 μL、10mg·mL- 1葡萄糖氧化酶(GOD)为 15 μL ,Nafion溶液为 6 0 μL .该电极用于测量葡萄糖时的线性范围为 :0~ 4mmol/L ,检测下限为 0 .4 μmol/L .结论 :该电极具有响应快速、灵敏、重现性好、寿命较长的特点 .  相似文献   

5.
γ-亚麻酸菌株少根根霉原生质体形成与再生   总被引:5,自引:1,他引:5  
用 6mg/m L纤维素酶 + 3mg/m L蜗牛酶 + 1 mg/m L溶菌酶作为混合酶酶解 2 8℃培养 2 6h的菌丝。以含 0 .6mol/L NH4Cl磷酸缓冲液 ( p H6.0 ) ,+ 0 .0 2 mol/L Mg SO4· 7H2 O+ 0 .4mmol/L Ca Cl2 作为渗透压稳定剂 ,酶解前以 0 .3% β-巯基乙醇处理 35 min,从少根根霉的菌丝中获得了大量的原生质体。同时对菌丝的培养时间、渗透压稳定剂、酶解系统和酶解温度等因素进行了观察 ,获得了制备原生质体的最适条件。并对该原生质体在高渗培养基上进行了再生实验  相似文献   

6.
建立了离子色谱-紫外检测器测定食品中亚硝酸盐和硝酸盐的分析方法。样品经超声提取后,以3.6 mmol/L Na_2CO_3溶液为流动相,经Metrosep A supp7-250阴离子交换分析柱,于210 nm处进行紫外检测。结果表明该方法在0.025~0.20 mg/L(亚硝酸盐)、0.10~2.0 mg/L(硝酸盐)范围内具有良好的线性关系,相关系数r均在0.999以上。亚硝酸盐和硝酸盐的检出限分别为0.004 5 mg/L和0.017 2 mg/L,检测下限分别为0.018 mg/L和0.068 mg/L,实际样品加标回收率分别为81.3%~87.3%和98.3%~103.1%,相对标准偏差小于5%。实验表明,该方法简便、灵敏,可用于测定食品中的亚硝酸盐和硝酸盐。  相似文献   

7.
通过研究,采用瑞士万通IC-882型离子色谱仪,Metrosep A Supp 5 250型阴离子分析柱,选用3.2mmol/L碳酸钠和1.0mmol/L碳酸氢钠为淋洗液,100mmol/L硫酸为抑制液,建立了用离子色谱法测定工业盐酸、试剂盐酸、工业草酸、精制盐水、结晶亚硫酸钠、原盐等样品中SO42-含量的分析方法。该方法具有良好的线性关系(0~75mg.L-1范围内相关系数为0.9999),样品加标回收率在88.1%~106.8%之间,相对标准偏差在1.80%~9.67%之间。实验表明:该方法操作快速、方便,满足化工产品中SO42-离子的快速检测要求,所测结果令人满意,值得推广应用。  相似文献   

8.
一体化Fenton反应器处理腈纶聚合单元生产废水   总被引:2,自引:0,他引:2  
采用自主设计一体化Fenton反应器,进行了处理腈纶聚合单元生产废水的效能及影响因素研究.结果表明,一体化Fenton反应器能实现对CODcr、丙烯腈及CN-的有效去除,同时提高了废水可生化性.获得的最佳工艺参数:H2O2和Fe2+投加量分别为0.2 mol/L和28.8 mmol/L,pH值3.0,停留时间150 min.出水回流可改善处理效果,在最佳工艺条件下,出水回流比为100%时,废水CODcr质量浓度可从1 247.9 mg/L降至124.1 mg/L,去除率为90%,废水中难生物降解的低聚物被彻底去除,特征污染物丙烯腈的质量浓度从75.5 mg/L降为0,CN-的质量浓度从5.40 mg/L降至0.12 mg/L,去除率为97.8%,出水可生化性指标从0.08提高到0.36.  相似文献   

9.
选取 2 3个品种 (系 )及 8个杂交组合F1的幼胚作为供试材料 ,取 12~ 16日龄的幼胚接种在附加 2 ,4 -D2 0mg/L和 6 -BA 1 0mg/L的MS培养基上 ,诱导 3~ 5d后所有供试材料都具有愈伤组织。筛选出适宜的继代培养基为 :MS +2 ,4 -D 4 0mg/L +NAA 0 5mg/L +LH 5 0 0mg/L +0 5 %蔗糖 +0 85 %琼脂 ;大穗 2、昌乐 2号、抗锈 2 0 4、品系 38等材料愈伤组织生长较好。植株再生适宜的培养基为 1/2MS +NAA 0 5mg/L +6 -BA0 5mg/L +0 3%蔗糖 +0 85 %琼脂。抗锈 2 0 4、昌乐 2号、优 2 6 5 /昌乐 2号、优 2 6 5 /京选 6号、优 2 6 5 /有芒白 4号等 5个供试材料分化率较高 ;杂交胚与常规品种比较 ,幼苗分化率表现出较强的杂种优势  相似文献   

10.
以杜仲(EncommiaulmoidesOliver)当年生枝条的叶片、带芽茎段为外植体,基本培养基为MS,附加不同浓度的BA、KT和NAA.最佳芽诱导培养基为:MS KT1 0mg/L NAA0 1~0 5mg/L;MS BA2 0mg/L NAA0 1~0 5mg/L,最佳芽丛增殖培养基为:MS KT2 0mg/L NAA0 1~0 2mg/L;MS BA1 0~2 0mg/L NAA0 1~0 2mg/L;MS KT2 0mg/L IBA0 1~0 2mg/L;MS BA1 0~2 0mg/L IBA0 1~0 2mg/L,单芽增殖培养基:MS KT1 0mg/L NAA0 1mg/L,生根培养基:13MS KT0 1mg/L NAA0 5mg/L.  相似文献   

11.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

12.
13.
Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications (up to 574.8 km/ h test speeds or 380 km/h commercial speeds) in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.  相似文献   

14.
Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to  相似文献   

15.
Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.  相似文献   

16.
为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。  相似文献   

17.
Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.  相似文献   

18.
The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.  相似文献   

19.
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   

20.
正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme  相似文献   

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