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排序方式: 共有329条查询结果,搜索用时 31 毫秒
91.
The interaction of cetyl trimethylammonium bromide (CTAB) with alpha-amylase from Bacillus subtilis was investigated at 25 degrees C and various experimental conditions, such as pH, ionic strength and urea concentration. The binding data were measured using CTAB-membrane selective electrodes as a simple, fast, cheap and accurate method. The obtained binding isotherms were analyzed using Wyman binding potential concept. The results represent the highest binding affinity at 10(-3) M of NaBr respect to other salt concentrations. The less binding affinity at pH 9.7 with respect to pH 6.5 is related to increasing of protein self aggregation with pH. The binding data analysis at various urea concentrations also shows that the predominate unfolding of alpha-amylase occurred in the urea concentration range of 3-5 M. 相似文献
92.
Tahereh Sharafi Majid M. Heravi Mitra Ghassemzadeh Bernhard Neumüller 《无机化学与普通化学杂志》2005,631(12):2297-2299
The reaction of 4‐amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione (AMTT, 1 ) with AgNO3 and triphenylphosphane in a molar ratio 1:1:2 in ethanol led to the dimeric complex {[Ag(AMTT)(PPh3)2]NO3}2·4EtOH ( 2 ). 2 was characterized by elemental analyses, IR, 31P NMR spectroscopy as well as single crystal X‐ray diffraction. Crystal data for 2 at ?80 °C: space group with a = 1265.5(2), b = 1300.9(2), c = 1509.5(2) pm, α = 83.77(2)°, β = 79.22(2)°, γ = 62.89(2)°, Z = 2, R1 = 0.0330. 相似文献
93.
Junes Ipaktschi Rahman Hosseinzadeh Peter Schlaf 《Angewandte Chemie (International ed. in English)》1999,38(11):1658-1660
A multiplication of functional units was accomplished in a simple fashion by the tetramerization of a quinodimethane. This principle is demonstrated by the convergent construction of a macrocyclic molecule with 16 ferrocenes and a macrocyclic molecule with 16 dendritic units at the periphery of the molecule (see scheme). FG=functional group 相似文献
94.
Tahereh Mousavand Jing Zhang Satoshi Ohara Mitsuo Umetsu Takashi Naka Tadafumi Adschiri 《Journal of nanoparticle research》2007,9(6):1067-1071
Titanium oxide (TiO2) nanocyrstals which are perfectly dispersed in organic solvents are synthesized by organic-ligand-assisted supercritical
hydrothermal synthesis. The addition of hexaldehyde to the supercritical hydrothermal synthesis of TiO2 leads to the in-situ surface modification, which enables the synthsized TiO2 nanocrystals to be perfectly dispersed in iso-octane because of its hydrophobic nature. Further, the one-pot synthesis of
hybrid materials results in the significant reduction of the particles size, probably due to the capping effect of hexaldehyde
to suppress the particles growth. 相似文献
95.
Ali Jebali Seyedhossein Hekmatimoghaddam Aliasghar Behzadi Iraj Rezapor Bahador Haji Mohammadi Tahereh Jasemizad Seyed Ali Yasini Morteza Javadzadeh Asiye Amiri Mansoure Soltani Zeynab Rezaei Najme Sedighi Mina Seyfi Mohammad Rezaei Mehran Sayadi 《Cellulose (London, England)》2013,20(6):2897-2907
In this study, cellulose nanoparticles were prepared by acid hydrolysis, separately conjugated with allicin and lysozyme by a carbodiimide cross-linker, and characterized by scanning electron microscopy, dynamic light scattering, and Fourier transform infrared spectroscopy. Then, their antimicrobial properties were evaluated by the microdilution method and compared with allicin, lysozyme, and nanocellulose alone. The results showed that nanocellulose had few antimicrobial activities, but allicin-conjugated nanocellulose (ACNC) and lysozyme-conjugated nanocellulose (LCNC) had good antifungal and antibacterial effects against standard strains of Candida albicans, Aspergillus niger, Staphylococcus aureus, and Escherichia coli. Noticeably, although allicin and lysozyme had different minimum inhibitory concentrations (MICs) against all strains, the same quantity of MIC50 and MIC90 was observed for both ACNC and LCNC. The authors suggest that both ACNC and LCNC can be used in industries as an antimicrobial agent in food packaging, inside foodstuffs, and in textile materials. 相似文献
96.
97.
F. Rezai Balf H. Zhiani RezaiG.R. Jahanshahloo F. Hosseinzadeh Lotfi 《Applied Mathematical Modelling》2012,36(1):46-56
One problem that has been discussed frequently in data envelopment analysis (DEA) literature has been lack of discrimination in DEA applications, in particular when there are insufficient DMUs or the number of inputs and outputs is too high relative to the number of units. This is an additional reason for the growing interest in complete ranking techniques. In this paper a method for ranking extreme efficient decision making units (DMUs) is proposed. The method uses L∞(or Tchebycheff) Norm, and it seems to have some superiority over other existing methods, because this method is able to remove the existing difficulties in some methods, such as Andersen and Petersen [2] (AP) that it is sometimes infeasible. The suggested model is always feasible. 相似文献
98.
99.
100.
The electrochemical behaviour of hydrazine at a 1‐benzyl‐4‐ferrocenyl‐1H‐[1,2,3]‐triazole‐triazole/carbon nanotube modified glassy carbon electrode has been studied. The modified electrode shows an excellent electrocatalytic activity for the oxidation of hydrazine and accelerates electron transfer rate. The electrocatalytic current increases linearly with hydrazine concentration in the range 0.5–700.0 μm and the detection limit for hydrazine was 33.0 ± 2.0 nm . The diffusion coefficient (D = 2.5 ± 0.1 × 10?5 cm2 s?1) and kinetic parameters such as the electron transfer coefficient, (α = 0.52) and the heterogeneous rate constant (k′ = 5.5 ± 0.1 × 10?3 cm s?1) for hydrazine were determined using electrochemical approaches. Finally, the method was employed for the determination of hydrazine in water samples. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献