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111.
Complexes of osmium tetroxide with nitrogen ligands were developed and used in our laboratory as probes of the DNA structure. Here, we show that the complex of osmium tetroxide with 2,2'-bipyridine (Os,bipy) can be used for modification and electrochemical detection of proteins at neutral pH. Salmon luteinizing hormone (SLH) containing two tryptophan (Trp) residues and human luteinizing hormone (HLH) containing one Trp were modified by Os,bipy and measured by differential pulse adsorptive stripping voltammetry (DPAdSV) at a hanging mercury drop electrode (HMDE). The intensity of the DPAdSV catalytic signals corresponded to the number of Trp residues in the peptide molecule. Decreasing pH of the background electrolyte from 6.6 to 3.8 led to the increase of DPAdSV signals, suggesting that at pH 3.8, the DPAdSV detection limit might be well below 1 ng/ml. Our results suggest that Os,bipy is potentially useful for chemical modification of proteins. 相似文献
112.
Ren Yanliang Cheng Lin Wan Jian Li Yongjian Liu Junjun Yang Guangfu Zhang Lihua Yang Song 《中国科学B辑(英文版)》2006,49(1):88-96
The electronic singlet vertical excited states of photosynthetic reaction center (PSRC) in Rhodopseudomonas (Rps.) viridis were investigated by ZINDO and INDO/S methods. The effects of the interactions of pigment-pigment and pigment-protein on
the electronic excitations were examined. The calculation results showed that the interactions of pigment-pigment and pigment-protein
play an important role in reasonably assigning the experimental absorption and circular dichroism (CD) spectra of PSRC in
Rps. virids. By comparing the theoretically computed excited states with the experimental absorption and CD spectra, satisfactory assignments
of the experimental spectroscopic peaks were achieved. 相似文献
113.
触头用银合金粉末的氧化性能和氧化后的组织结构 总被引:1,自引:0,他引:1
通过热重实验和扫描电子显微等方法,研究了4种触头用银合金粉末的氧化性能及氧化后的组织结构。发现Ag-Sn-RE合金粉末氧化以后,在粉末表层形成一层纯银层,其组织结构理想;它的氧化性能最好,适于制备触头材料。Ag-Sn-RE合金粉末的优良氧化性能与其氧化后理想的组织结构有关。稀土元素可以降低合金粉末的氧化温度,其它影响作用有待于进一步研究。 相似文献
114.
Microwave discharges of HBr/H2/Ar and H/H2/Ar with additional do biasing of the sample were used to etch InP, GaAs, and AlGaAs at temperatures between 50–250°C. The etch rates increase by factors of 3–50 and 5–9, respectively, for HBr-and HI-based discharges over this temperature range, but display non-Arrhenius behavior. The etched surfaces became very rough above 100°C for InP with either discharge chemistry due to preferential loss of P, while GaAs and AlGaAs are more tolerant of the elevated temperature etching. The near-surface electrical properties of InP are severely degraded by etch temperatures above 100°C, while extensive hydrogen in-diffusion occurs in GaAs and AlGaAs under these conditions, leading to dopant passivation which can be reversed by annealing at 400°C. 相似文献
115.
Xianmei Xie Xiurong Ren Jinping Li Xiaojun Hu Zhizhong Wang 《天然气化学杂志》2006,15(2):100-104
Ultrasonic technology has been intensively studied recently due to its special features. In this paper, an ultrasonic crystallization method was introduced for the preparation of ZnAl-Hydrotalcite-Like compounds (ZnAl-HTLcs). Samples with high crystallinity, small particle size and narrow particle size distribution were obtained and fully characterized using conventional techniques of XRD, FT-IR and TGDTA. The results prove that both ultrasonic frequency and ultrasonic power have effects on the sizes of the product particles. By varying the ultrasonic power from 250 W to 88 W, with the ultrasonic frequency fixed at 59 kHz, the median particle size of the samples increased from 0.37 μm to 0.82 μm. By altering the hydrothermal treatment time from 1 h to 5 h at 110℃, the median particle size of ZnAl-HTLcs synthesized via ultrasonic crystallization increased from 0.88 μm to 1.11 μm. 相似文献
116.
117.
苯胺类化合物的电化学氧化及随后化学反应 总被引:4,自引:0,他引:4
利用循环伏安法研究了二取代对苯二胺(1),四取代对苯二胺(2)和二取代氨基酚(3)三类化合物以及它们的衍生物的电化学行为及其氧化产物的随后不可逆脱氨反应。 1类化合物在任何pH下的电化学氧化均为一步双电子转移反应,2类化合物为二步单电子转移反应;3类化合物在酸性和中性范围为一步双电子氧化在碱性溶液中为二步单电子转移反应。文中定量求算了不可逆随后化学反应的表观水解速率常数k_f,并进行了讨论。 相似文献
118.
采用穆斯堡尔谱及X光衍射法研究了共沉淀法制备的不同Fe/Mn比催化剂在焙烧、合成气还原及FT反应后体系相结构的变化。结果表明:锰助剂的加入使催化本相由铁磁性逐渐转化为超顺磁性,相应使催化剂还原逐渐难,Mn助剂促进了FT合成反应进行。反应性能与Fe/Mn尖晶石(Fe1-yMny)3O4组成含量及式中y大小密切相关,与MnCo3及MnO的存在也有一定关系。富铁催化剂中Mn主要起电子助剂作用,而富锰催化 相似文献
119.
Growth of porous single-crystal Cr2O3 in a 3-D mesopore system 总被引:1,自引:0,他引:1
Jiao K Zhang B Yue B Ren Y Liu S Yan S Dickinson C Zhou W He H 《Chemical communications (Cambridge, England)》2005,(45):5618-5620
Single-crystal Cr2O3 with regular mesopores has been synthesized using mesoporous silica KIT-6 as a template and characterized by using XRD, HRTEM and nitrogen adsorption/desorption. 相似文献
120.