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1.
在烧结镍基体表面,预先电沉积一层氧化铈,通过电化浸渍得到镍电极,研究了预先电沉积氧化铈对烧结镍电极性能的影响。结果表明:与空白烧结镍电极相比,预先电沉积氧化铈(+4),改善了烧结镍电极的大电流充放电性能和循环性能,增加了电极的可逆性,提高了电极的充电接受能力和活性物质利用率,减少了电极膨胀率,且当氧化铈的预先电沉积量为5%时,烧结镍电极的电极性能处于最佳。  相似文献   

2.
聚吡咯修饰乳酸氧化酶电极的研制   总被引:2,自引:0,他引:2  
根据聚吡咯修饰电极掺杂和去掺杂原理,将乳酸氧化酶固定在玻碳电极表面形成一种新型的乳酸酶电极,该电极灵敏度高,稳定性好,易于制作。本文报道了该电极的研制过程,探讨了影响电极响应的各种因素,找出了最佳实验条件。将此电极用于实际样品中乳酸含量的测定,结果令人满意。  相似文献   

3.
在电化学工程中,常用一些具有三线结构的材料作为电极,如金属泡沫、碳纤维毡等.这种电极的优点是具有比平面(二维)电极大得多的电化学界面,常称三维电极·所谓双极三维电极是指在一种特殊状态下工作的三维电极:同一三维电极体的两侧分别发生阴极和阳极电极反应[‘,2]  相似文献   

4.
一种适于高速充电的新型化学电源电极的研究   总被引:2,自引:0,他引:2  
尤金跨 《电化学》1999,5(4):418-423
本文提出一种适于高速充电的新型化学电源电极,该电极体系在充电时,反应界面能迅速推移,使活性物质能迅速沉积在三维载体电极上,特别适用于强电流高速充电。充电时活性物质以固态沉积在电极表面,而放电时活性物质又溶解为液态。电极体系在充放电循环过程中活性物质是以固(态)-液(态)循环形式进行循环,因而可以保持新鲜的电极表面,防止固体电极表现活性物质的相变、脱落、变形等弊端,有利于延长电极的寿命,该电极体系可  相似文献   

5.
全固态锂离子选择性电极研究   总被引:1,自引:0,他引:1  
研究了新型载体HPMBP-TOPO体系几种全固态锂离子选择性电极(涂丝电极、单层全固态电极、聚吡咯修饰层内接触电极)的性能。与传统型电极相比,固态电极响应斜率有所降低,而选择性稍有提高。其中聚吡咯修饰层内接触电极性能为最佳,该电极响应斜率为56.7mV/decade,并具有良好再现性和长期稳定性。  相似文献   

6.
纳米超微电极的研究(Ⅳ)──超微金柱电极的制作与表征张学记,万其进,张悟铭,周性尧(武汉大学化学系,武汉,430072)关键词微电极,纳米超微电极,伏安法,离子束,金纤维最近,纳米超微电极[1~5]的研制成功,使超微电极的研究进入一个新阶段,给电化学...  相似文献   

7.
8—羟基喹啉合镁碳糊修饰电极的研究   总被引:2,自引:0,他引:2  
孙玉堂  吴建人 《分析化学》1995,23(5):582-585
本文研制了8-羟基喹啉合镁碳糊修饰电极,并研究了电极性能,实验发现,该修饰电极具有类化学传感器的特性,电极在一定条件下对Mg^2+离子有类能斯特响应,电极用于试样分析取得成功。  相似文献   

8.
运用电化学循环伏安和石英晶体微天平研究了HClO4溶液仲丁醇在Pt电极及以Sb和S吸附原子修饰的Pt(Pt/Sbad和Pt/Sad)电极上的电催化氧化过程,从电极表面质量变化可以看出,仲丁醇的氧化与电极表面的氧物种表面的氧物种有着极其密切的关系,Pt电极表面Sb吸附原子可在较低的电位下吸附氧,明显提高仲丁醇的氧化活性,与Pt电极相比,Sb吸附原子修饰的Pt电极使仲丁醇氧化的峰电位负移约100mV,相反,Pt电极表面S吸附原子的氧化会消耗表面氧物种,抑制仲丁醇的氧化,从电极表面质量变化提供了吸附原子电催化作用的数据。  相似文献   

9.
对插型阵列微带电极的制作及其电化学特性研究   总被引:1,自引:0,他引:1  
用微电子光刻方法制作了对插型阵微带电极(IDA),并通过SEM对IDA电极进行了表征,将微Ag/AgCl参比电极和微铂丝对电极固定在IDA电极附近,构成了微电解池,考察了该电极的循环伏安及计时电流特性,并用微带电极的扩散理论和Cottrell 公式对IDA电极的准稳太电流进行了处理,指出了它们之间产生偏差的原因,研究了IDA电极的“发生-收集”效应,测定了该电极的屏蔽因子、反馈因子和收集效率。  相似文献   

10.
赵凯元 《分析化学》1998,26(7):914-914
1引言我们曾用2B型铅笔芯制成电极并经实验证明它具有与玻碳电极类似的良好伏安特性。也曾用它作为基体电极,修饰8-羟基喹啉,研究了铜和锌的阳极溶出特性。本文研究了l-(2-吡啶偶氮)-2-萘酚(PAN)修饰的铅笔芯电极上铜的阳极溶出伏安特性,并用以测定了人发中的微量铜。探讨了铜在此电极上的预富集与溶出机理。2实验部分2.1仪器与试剂MEC-12A型电化学分析仪,以PAN修饰电极为工作电极,饱和甘汞电极为参比电极,铂电极为辅助电极,组成三电极体系。所有试剂均为分析纯试剂。水为二次去离子水。2.2电极…  相似文献   

11.
The accelerated growth of aquaculture has resulted in a series of harmful effects to human health. The widespread and unrestricted use of antibiotics in this industry, to prevent bacterial infections, leads to remaining amounts in the aquatic environment. This has resulted in the emergence of antibiotic-resistant bacteria in aquaculture environments, in the increase in antibiotic resistance in fish pathogens as well as in the transfer of these resistance determinants to human pathogens. Moreover, the use of large amounts of antibiotics may lead to the presence of residual antibiotics in fish tissue and fish products. Fluoroquinolones, tetracyclines, penicillins, sulphonamides and other antibiotics, exhibiting activity against both Gram-positive and Gram-negative bacteria, are widely used for the treatment and prevention of diseases in fish. An extended and comprehensive review on the recent analytical methodologies concerning antibiotic residues in fish reported in the literature is provided in the present article. Emphasis is given on sample preparation regarding isolation and purification, chromatographic conditions and method validation according to legislation. Results of published assays are comparatively presented and criticised.  相似文献   

12.
用原子吸收光谱法测定了陕西汉中地区266例健康男女青少年头发中5种金属元素的含量。并进行了直线相关回分析。结果表明,青春期女性头发中的铜,锌、铁、钙,镁5种元素的含量皆明显高于同年龄段男性;Ca与Mg、Zn、Fe元素含量之间有不同程度的相关。  相似文献   

13.
采集了贵族个煤烘玉米为主要介质和河北2个饮水为介质氟病区内骨畸形病人的全血、尿、检测了其中8种元素含量,结果表明,贵州各氟病区少儿骨软化与成年骨硬化畸形病人的全血铝、钙、磷、铁和尿氟、铝均显著高于同龄对照组,尿磷均低于同龄对照组。少儿骨软化病人全血锌均下降,尿锌多下降。某水型氟病区骨软化经产妇尿氟、全血铜升高;骨软化少年全血铝显著升高,锌、铁下降,尿氟升高,尿锌,磷下降。海边的典型氟骨症病人全血、  相似文献   

14.
综述了壳聚糖、甲壳素在污水处理、电化学、原子吸收光谱、高效液相色谱、吸光光度法中的应用。引用文献28篇。  相似文献   

15.
Asymmetric catalysis, in its infancy in the 1960s, has dramatically changed the procedures of chemical synthesis, and resulted in an impressive progression to a level that technically approximates or sometimes even exceeds that of natural biological processes. The recent exceptional advances in this area attest to a range of conceptual breakthroughs in chemical sciences in general, and to the practical benefits of organic synthesis, not only in laboratories but also in industry. The growth of this core technology has given rise to enormous economic potential in the manufacture of pharmaceuticals, animal health products, agrochemicals, fungicides, pheromones, flavors, and fragrances. Practical asymmetric catalysis is of growing importance to a sustainable modern society, in which environmental protection is of increasing concern. This subject is an essential component of molecular science and technology in the 21st century. Most importantly, recent progress has spurred various interdisciplinary research efforts directed toward the creation of molecularly engineered novel functions. The origin and progress of my research in this field are discussed.  相似文献   

16.
李艳梅  王秀红 《化学教育》2006,27(4):8-10,13
逻辑推理过程与事物的认识过程同时存在,科学探究离不开逻辑推理过程。归纳和演绎是认识过程中的两种逻辑推理形式,在学生的科学探究活动中,尤其是在提出问题、猜想与假设、设计实验方案与解释结论阶段,归纳和演绎发挥着重要的作用。本文重点论述了寻求现象原因的求异归纳推理、探寻化学物质通性及变化规律的不完全归纳推理、探求个别物质性质的演绎三段论、解释个别现象的演绎解释推理过程在科学探究中的重要作用。  相似文献   

17.
Despite many advances in therapy, glioblastoma (GB) is still characterized by its poor prognosis. The main reason for this is unsuccessful treatment, which slightly extends the duration of remission; thus, new regimens are needed. One of many types of chemotherapeutics that are being investigated in this field is topoisomerase inhibitors, mainly in combination therapy with other drugs. On the other hand, the search for new anti-cancer substances continues. Neobavaisoflavone (NBIF) is a natural compound isolated from Psoralea corylifolia L., which possesses anti-oxidant, anti-inflammatory, and anti-cancer properties. The aim of this study was to evaluate the effect of NBIF in human U-87 MG glioblastoma cells in comparison to normal human NHA astrocytes, and to examine if it influences the activity of irinotecan, etoposide, and doxorubicin in this in vitro model. We demonstrated that NBIF decreases U-87 MG cells viability in a dose-dependent manner. Furthermore, we found that it inhibits cell growth and causes glutathione (GSH) depletion more intensely in U-87 MG cells than in astrocytes. This study also provides, for the first time, evidence of the potentialization of the doxorubicin effect by NBIF, which was shown by the reduction in the viability in U-87 MG cells.  相似文献   

18.
Concentrations of butyltin compounds (mono-, di-, and tri-butyltin) were determined in dolphin ( Platanista gangetica ), fish, invertebrates and sediment collected from the River Ganges, India, in order to understand the contamination levels, sources, and potential for biomagnification in freshwater food chains. Total butyltin concentration in dolphin tissues was up to 2000 ng g−1 wet wt, which was about 5–10 times higher than in their diet. The concentrations in fish and benthic invertebrates, including polychaetes, were 3–10 times greater than in sediment. The biomagnification factor for butyltins in river dolphin from its food was in the range 0.2–7.5. Butyltin concentrations in Ganges river organisms were higher than those reported for several persistent organochlorine compounds. Discharge of untreated domestic sewage was one of the major sources of butyltin residues in Ganges river biota. High concentrations of butyltin compounds in freshwater food chains suggest the need to assess their toxic effects in aquatic organisms and to regulate their use. © 1997 by John Wiley & Sons, Ltd.  相似文献   

19.
《Analytical letters》2012,45(13):2122-2131
China has one of the fastest-growing economies in the world, but this economic development has important implications for environmental changes in this country. Our research was to quantify the presence of heavy metals in soil and water environments in the Tianshan Mountains region of China, associated with the economic development of this region. We used anomaly analysis, correlation analysis, and principal component analysis to assess the occurrence characteristics of heavy metals in this area. Results showed that Co, Cr, As, and Ni are more prevalent in water environments than in soil environments; in contrast, Cd, Zn, Pb, Hg, and Mn are more prevalent in soil samples than in water samples. This analysis grouped 10 heavy metals in soil and water environments into three principal components. In soil environments, the prevalence order was Co, Ni, Cr, As > Mn, Zn, Pb > Hg, Cd, Cu. In water environments, the order was Cu, Co, Ni, Cr, As > Hg, Mn, Zn > Cd, Pb. It is possible to distinguish between the natural and the anthropogenic sources of heavy metals in the Tianshan Mountains. With the current rapid economic development in the Tianshan Mountains, anthropogenic sources are playing principal roles in serious heavy metal accumulations in this region. This problem warrants immediate and widespread attention to prevent further deterioration of the soil and water environments.  相似文献   

20.
电化学发光分析的新进展   总被引:13,自引:0,他引:13  
王鹏  袁艺  朱果逸  张密林 《分析化学》1999,27(10):1219-1225
电化学发光技术作为一种新的痕量生化分析手段越来越引人注目。介绍了电化学发光基础研究的最新进展,并评述了电化学发光技术的环境分析,免疫分析,核酸杂交分析及其它生化物质测定中的一些最新应用。  相似文献   

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