甲基绿探针吸收光谱法测定安乃近

甲基绿与安乃近在pH 9.60的碱性介质中相互反应生成具有3个负吸收峰的离子缔合物,产生明显的褪色现象。最大褪色波长位于670nm,表观摩尔吸光系数为1.82×104 L/(mol·cm);次大褪色波长为424nm,表观摩尔吸光系数为1.50×104 L/(mol·cm),安乃近浓度为4.0×10-6~1.8×10-5 mol/L对670nm和4.0×10-6~1.4×10-5 mol/L对424nm光的吸光度与浓度关系遵从比尔定律,据此建立了以甲基绿为探针测定安乃近的吸收光谱法。该法用于实际样品中安乃近的测定,结果满意。     

基于Nafion固定天青Ⅰ和纳米CdS共修饰玻碳电极的H2O2生物传感器

利用滴涂于玻碳电极(GCE)表面的以Nafion膜中负电性的磺酸基与天青I(AI)阳离子之间的静电作用,实现天青I在电极上的固定化,再通过静电吸附和自组装技术将纳米CdS吸附的辣根过氧化物酶(HRP)修饰到电极表面,制备出性能良好的H2O2生物传感器.采用循环伏安法(CV)和计时电流法考察了该传感器的电化学性质.实验表明,该传感器具有良好的生物催化活性,较高的灵敏度,良好的选择性和稳定性,且易于制作等特点.响应电流与H2O2浓度在8.0×10-6~1.6×10-3mol/L范围呈现良好的线性关系,检出限为2.72×10-6mol/L.     

碱性条件下氯化血红素模拟过氧化物酶的研究

文章研究了氯化血红素（Hemin）作为模拟过氧化物酶在[NaOH]=3.81×10-2mol/L的水溶液及胶束溶液（Brij35/SDS）中催化过氧化氢氧化苯酚红的反应。结果表明：在过氧化氢和苯酚红的溶液中加入氯化血红素（Hemin）能够大大促进此氧化反应的速度,胶束溶液所提供的微环境对此氧化反应有较大的影响,在[Hem]=1.67×10-5mol/L,[H2O2]=0.03213mol/L,[苯酚红]=2.0×10-5mol/L时,氧化反应的表观一级速率常数分别为1.68（H2O）,1.55（SDS）,1.14（Brij35）（×10-3s-1）。     

九钼锰酸铵的合成和动力学测定

以(NH4)6Mo7O24·4H2O,MnSO4·H2O和(NH4)2S2O8为原料合成(NH4)6[MnMo9O32]·8H2O(八水合九钼锰酸铵),用紫外可见电子光谱分析法对该化合物进行表征;以490 nm为测定波长,测定浓度为8×10-4mol/L的(NH4)6[MnMo9O32]溶液与浓度分别为4×10-3、6×10-3、8×10-3、12×10-3 mol·L-1的酒石酸溶液进行氧化还原反应时的吸光度.以不同浓度的In(A-A∞)对T作图呈线型关系,确定氧化剂反应级数为一级反应.以不同浓度的Kobs对还原剂浓度作图,其图形也呈直线,确定还原剂反应级数也为一.     

聚天青A和纳米CdS修饰的H2O2生物传感器

制备以电子媒介体天青A和纳米CdS来固定辣根过氧化物酶(HRP)修饰的H2O2生物传感器.采用循环伏安法(CV)、计时电流法对该传感器的性能进行了研究.试验表明,该传感器对H2O2浓度在4.0x10-6～1.2x10-3mol/L内呈线性关系,检出限为1.4x10-6mol/L.     

对草酸与高锰酸钾反应的探究

一、引言 为验证浓度对反应速率的影响,普通高中课程标准实验教科书化学(选修4)第22页设计实验如下:取两支试管,各加入4 mL 0.01mol/L的KMnO4溶液,然后向一支试管中加入0.1 mol/L H2C2O4(草酸)溶液2 mL,记录溶液褪色所需的时间;向另一支试管中加入0.2 mol/L H2C2O4溶液2 mL,记录溶液褪色所需的时间.     

极谱法分析苯巴比妥

报道了吡啶铜与苯巴比妥络合物的极谱波.在0.1 mol/L的H2SO4溶液中,吡啶铜-苯巴比妥体系在-1780 mV处产生一个灵敏的极谱波.该吸附还原波的二阶导数峰电流与苯巴比妥浓度在6.0×10-7~2.0×10-3mol/L范围内呈线性关系,相关系数R=0.997;检出限为3.0×10-8mol/L.据此建立了测定苯巴比妥的新方法.此法已成功的用于巴比妥类药物的测定.     

纳米银-石墨烯修饰玻碳电极检测咖啡因

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。     

5-溴水杨醛甘氨酸修饰碳糊电极测定微量Cu2+的研究

在pH=9.0 H3BO3-Na2B4O7缓冲体系中,以5-溴水杨醛甘氨酸修饰碳糊电极为工作电极,Cu2 于 120mV(vs.SCE)处产生一灵敏的吸附波,其二阶导数峰电流与Cu2 浓度在4.0×10-9~8.0×10-7mol.dm-3范围内呈良好的线性关系,相关系数为0.9964,检出限为6.0×10-10mol.dm-3(3倍信噪比)。应用该法测定发样中Cu2 的含量,结果令人满意。     

以PVC膜碘离子电极测定大米中碘的含量

本文报导在 0 .0 5mol/L硼砂缓冲溶液中 ,以PVC膜碘离子电极直接电位法测定大米中碘的含量 ,方法灵敏度为 3× 10 - 7mol/L ,线性范围为 5× 10 - 7～ 10 - 3mol/L ,以该方法对蒸水沿岸地方的大米中的碘测定 ,分析表明 ,该地区中碘含量处在 0 .2～ 0 .6mg/kg范围 .     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

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?     

Western and Eastern culture differences in commercial field

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.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

风的曲线

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.     

团图为数的图中的闭团贯数

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.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.