共查询到20条相似文献，搜索用时 296 毫秒
1.
黄西朝 《渭南师范学院学报》2012,(6):61-63
报道了一种以乙基紫为定域体试剂、溶胶一凝胶法制备的碘离子电极,该电极的线性范围为9．0×10^-7moL／L-1．0×10^-7mol／L,平均斜率为58．4mV／decade,检测下限为7．6×10^-7mol／L,适宜pH范围为3．1-11．5． 相似文献
2.
报道一种以平痛新与碘汞酸盐形成的分子缔合物为电活性物的新型PVC膜平痛新离子选择电极。电极的Nernst响应范围为1.0×10-4mol/L~1.0×10-1mol/L;斜率为58mV/pC;检测限为9.0×10-5mol/L。电极响应迅速,重现性好,而且具有制作简单、使用方便的特点。已将该电极应用于盐酸平痛新药片中测定平痛新的含量,结果与紫外分光光度法相符。 相似文献
3.
鲁米诺—碘化学发光反应的研究 总被引：1，自引：0，他引：1
李先文 《渭南师范学院学报》1993,(Z1)
碘和鲁米诺在碱性水溶液中相互作用产生化学发光。本研究发现,化学发光强度与碘溶液浓度和溶液的PH值有关。在PH值为11.50的H_3B_3O_3-KOH介质中,在3.0×10-7mol/dm~3～3.0×10~(-5)mol/dm~3碘浓度范围内,化学发光强度与碘溶液的浓度成线性关系。 相似文献
4.
在乙酸-乙酸钠缓冲溶液及NaCl的介质中,碘能催化高碘酸钾氧化龙胆紫的褪色反应.据此建立了催化动力学测定微量碘的新方法.此方法的检出限为CL=6.7×10-2μg/mL,碘的线性范围为:0.2728mg/L～54.56mg/L,可直接用于加碘食盐、海带中碘的测定,结果满意. 相似文献
5.
本文合成了双硫腙-Hg(Ⅱ)金属载体化合物,考察了该载体对阴离子的电位响应情况,其选择性次序为:I~->ClO_4~->SCN~->Br~->Sal~->NO_3~->NO_2~->IO_3~->HCO_3~->Cl~->HPO_4~(2-),具有明显的反Hofmeister行为。以双硫腙-Hg(Ⅱ)为载体,膜组成:双硫腙-Hg(Ⅱ):PVC:邻硝基苯基辛醚为 0.15:30:70。在30℃,0.05mol·dm~(-3)Na_2HPO_4 -0.05mol·dm~(-3)NaH_2PO_4 介质中,电极在 5×10~(-4)-10~(-6)mol·dm~(-3)碘离子浓度范围呈线性响应,斜率为 53±2mV/dec。检测下限为 6×10~(-7)mol·dm~(-3)。在 10~(-6)mol·dm~(-3)以上,响应时间 3至 5分钟,10~(-6)mol·dm~(-3)以下,响应时间在 8分钟左右,在碘离子浓度为 5×10~(-5)至5×10~(-6)mol·dm~(-3)溶液中交替测定 10次,电位标准差少于1mV,电极用于食盐中碘的测定,结果令人满意。 相似文献
6.
本文采用化学还原氧化石墨烯的方法制备了纳米银-石墨烯(Ag-GR)复合材料,用此材料制备了纳米银-石墨烯电化学传感器(Ag-GR/GCE),并利用循环伏安法研究了咖啡因的电化学行为。以0.01 mol/L的H2SO4为底液在0.51.7 V电压范围,于1.579 V左右有一氧化峰,线性范围为2×10-61.7 V电压范围,于1.579 V左右有一氧化峰,线性范围为2×10-66×10-5 mol/L和6×10-56×10-5 mol/L和6×10-52×10-3 mol/L,检出限(S/N=3)为6×10-7 mol/L。将传感器已用于咖啡因的检测,效果较好。 相似文献
7.
基于在甲醛存在下,3,4-二羟基苯甲酸与高锰酸钾在酸性介质中发生化学发光反应,建立了测定痕量的3,4-二羟基苯甲酸化学发光分析法,该法测定3,4-二羟基苯甲酸的线性范围为5.0×10.～1.0×10-5mol/L,检出限为3.0×10-7mol/L,相对标准偏差为3.O%(1.0×10-6mol/L3,4-二羟基苯甲酸n=11).该法应用于测定淠河水中加入的3,4-二羟基苯甲酸,结果令人满意. 相似文献
8.
基于在碱性介质中阿莫西林对鲁米诺-K3Fe(CN)6化学发光反应有强烈的增敏作用,建立了测定阿莫西林的流动注射化学发光分析法.在最佳的实验条件下,该方法的线性范围为1.0×10-7~1.0×10-5mol/L,检出限为3×10-8mol/L,对1.0×10-6mol/L的阿莫西林连续测定9次的相对标准偏差RSD为3.6%. 相似文献
9.
在盐酸介质中,碘酸钾与钙红反应褪色程度与碘酸根浓度在一定范围内呈线性关系,以此建立了碘的光度测定新方法。方法的最大吸收波长在510nm处,碘定量测定的线性范围为0．3mVL,摩尔吸光系数ε=1．3×10^4L／mol·cm。本法所得结果和国家标准（GB5009．24．85）中规定食盐中碘含量的测定方法相当。 相似文献
10.
以镍（Ⅱ）-四氮杂轮烯大环配合物为载体,制备了一种新型PVC膜碘离子化学传感器．研究结果表明,该传感器对碘离子的线性响应范围为3．0×10－6～1．0×10－1mol·L－1,响应斜率为57.3±0．3mV·dec－1．该传感器具有良好的重视性和选择性． 相似文献
11.
罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
12.
Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
13.
邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
14.
Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
15.
16.
17.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
18.
陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
19.
Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
20.
YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献