首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
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.
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   

6.
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   

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.
离子色谱法测定水产品中多聚磷酸盐的含量   总被引:3,自引:0,他引:3       下载免费PDF全文
采用离子色谱法测定保鲜水产品中焦磷酸钠、三聚磷酸钠和三偏磷酸钠的含量。该方法通过温度控制和快速萃取法阻止多聚磷酸盐降解,用三氯甲烷和乙酸铅溶液沉淀蛋白,用25mmol/L KOH溶液进行梯度淋洗。研究结果显示,3种被测物的检出限分别为3mg/kg、2mg/kg、3mg/kg,线性相关系数r为0.9995~0.9997,回收率为92.7%~101.2%,相对标准偏差小于2%。该检测方法简便、快速、重复性好。  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.
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   

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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号