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51.
X.-J. Chen W. Miao Y. Liu Y.-F. Shen W.-S. Feng T. Yu Y.-H. Yu 《Journal of Thermal Analysis and Calorimetry》2006,84(2):429-433
Using isothermal microcalorimetry, the growth power-time
curves of three strains of Tetrahymena
were determined at 28°C. Their Euclidean distances and cluster analysis
diagram were obtained by using two thermokinetic parameters (r
and Qlog), which
showed that T. thermophila BF1
and T. thermophila BF5
had a closer relationship. Compared with the single molecular biomarker (ITS1)
method, microcalorimetry wasmaybe a simpler, more sensitive andmore economic
technique in the phylogenetic studies of Tetrahymena
species. 相似文献
52.
Yang M Wang W Yuan F Zhang X Li J Liang F He B Minch B Wegner G 《Journal of the American Chemical Society》2005,127(43):15107-15111
The synthesis of a block codendrimer (g3-PBE-b-g3-PMDC), composed of a third-generation poly(benzyl ether) (PBE) monodendron and an aliphatic polyether (PMDC) monodendron is reported. In THF/diiospropyl ether (1:1) the PMDC block functions as a "hydrophilic" block, while the PBE acts as a "hydrophobic" block. The codendrimer can form interdigitated layers leading to vesicle formation. Tapping mode atomic force microscopy (AFM), dynamic light scattering (DLS), and transmission electron microscopy (TEM) were used to characterize the vesicles. The effect of molecular architecture on the formation of the interdigitated layers and vesicles was studied. 相似文献
53.
L. Zhao L. Robinson R. L. Paul R. R. Greenberg S. L. Miao 《Journal of Radioanalytical and Nuclear Chemistry》2007,271(3):777-782
This paper describes the use of cold-neutron prompt-gamma activation analysis (CNPGAA) to determine carbon, nitrogen, and
phosphorus in the aquatic plant Typha domingensis, commonly known as cattail, during spring and fall seasons. According to studies of the Florida Everglades, cattail replaces
sawgrass as a result of nutrient enrichment from farm water runoff. Nutrient enrichment, especially phosphorus, in sediment
and the water column can lead to undesirable expansion. Early signs of this expansion are apparent in the Apalachicola River
floodplain near Apalachicola, Florida, USA. This research project is designed to use cattails as biomonitors of nutrient enrichment
in the lower Apalachicola River floodplain. Determination of carbon, nitrogen, and phosphorus in cattail using cold neutron
prompt-gamma activation has been developed in our previous studies at the CNPGAA facility at the National Institute of Standards
and Technology (NIST), USA. The results of numerous field samples, collected from the study area during spring and fall seasons
in 2002, will be presented in this paper. 相似文献
54.
Jin‐Yu Sun Zhen Zhao Yong‐Chao Ma Miao‐Li Zhu Xiang‐Dong Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(1):m4-m6
The crystal structure of the title compound, μ‐2‐hydroxybutanedioato‐1κ2O4,O4′:2κ3O1,O2,O4‐nitrato‐2κO‐tris(1,10‐phenanthroline)‐1κ4N,N′;2κ2N,N′‐dicopper(II) nitrate tetrahydrate, [Cu2(C4H3O5)(NO3)(C12H8N2)3](NO3)·4H2O, contains an unsymmetrical dinuclear copper complex with Cu(phen)2 and Cu(phen)(NO3) moieties (phen is 1,10‐phenanthroline) bridged by a malate (2‐hydroxybutanedioate) ligand, which acts as a double‐bridging and tetradentate ligand. As a result of this double‐bridging action, especially the direct coordination of the O atom of one carboxylate group of malate to the two Cu atoms, the Cu⋯Cu distance is only 4.199 (1) Å and the two phen planes are roughly parallel [the shortest interplanar distance is 3.28 (1) Å], exhibiting an obvious intramolecular π–π stacking interaction. 相似文献
55.
Shi‐Dong Qin Miao‐Li Zhu Li‐Ping Lu Si‐Si Feng Hong‐Mei Zhang Pin Yang 《无机化学与普通化学杂志》2005,631(10):1761-1762
The novel dinuclear Ni2+ complex [Ni2(μ‐Cl)(μ‐OAc) (EGTB)]·Cl·ClO4·2CH3OH, where EGTB is N, N, N′, N′‐tetrakis (2‐benzimidazolyl methyl‐1, 4‐di‐ethylene amino)glycol ether, crystallizes in the orthorhombic space group Pnma with a = 15.272(2), b = 14.768(2), c = 22.486(3) Å, V = 5071.4(12) Å3, Z = 4, Dcalc = 1.414 g cm?3, and is bridged by triply bridging agents of a chloride ion, an acetate and an intra‐ligand (‐OCH2CH2O‐) group. The nickel coordination geometry is that of a slightly distorted octahedron with a NiN3O2Cl arrangement of the ligand donor atoms. The Ni–Cl distance is 2.361(2) Å, and two Ni–O distances are 1.996(5) and 2.279(6) Å. The three Ni–N distances are 2.033(7), 2.060(6), and 2.166(6) Å with the Ni–N bond trans to an ether oxygen the shortest, the Ni–N bond trans to an acetate oxygen the middle and the Ni–N bond trans to Cl the longest. 相似文献
56.
A capillary electrophoresis (CE) with UV absorption detection method is described for the simultaneous determination of glufosinate, glyphosate, and aminomethylphosphoric acid. The 9‐fluorenylmethyl chloroformate (FMOC‐Cl) was used for precolumn derivatization of the non‐absorbing herbicides. The three analytes were separated by CE in 9 min with 25 mM borate buffer at pH 9, followed by detection with a UV detector at 260 nm. We demonstrate how the detection limit can be enhanced by using acetonitrile‐salt mixtures. With acetonitrile‐salt mixtures, the limit of detection (LOD) was in the 10?7 M range. Linearity of more than two orders of magnitude was generally obtained. Precisions of migration times and peak areas were less than 0.9% and 7.5%, respectively. The applicabilities of the method for the analysis of ground water and lake water were examined. 相似文献
57.
采用盆栽试验研究了Nd3 在不同诱导时间对番茄叶抗性指标(过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨酸解氨酶(PAL)活性、细胞膜透性、氧自由基(O2-·)产生速率和木质素含量)的影响.结果表明:从第3 d开始,Nd3 诱导提高番茄叶内PAL活性,第3d增幅也最大,达32.30%,维持时间为诱导后第3~5 d;Nd3 诱导后第1~2 d POD活性升高,第1 d增幅最大,维持时间是诱导后第1~2 d;Nd3 诱导后1~3 d,PPO活性升高,第1 d增幅最大,维持时间是诱导后第1~3 d;从诱导后第2 d开始,Nd3 降低细胞膜透性,第3 d时降幅最大,为54.33%,持续时间为诱导后第2~5 d;从第3 d开始,Nd3 诱导降低氧自由基产生速率,第4 d降幅最大,第3 d氧自由基产生速率最低,持续时间为诱导后第3~5 d;从第4 d开始,Nd3 诱导提高木质素含量,5 d时有继续升高的趋势.从不同诱导时间番茄叶PAL活性、细胞膜透性、氧自由基产生速率的变化来看,在Nd3 诱导的第3 d,番茄产生的抗性最强. 相似文献
58.
The use of capillary electrophoresis (CE) with laser-induced fluorescence excited by ultraviolet (UV) lasers in the range 200–300 nm has been restricted by the available wavelengths and expense of UV lasers. The integration of a NeCu deep UV laser operating at 248.6 nm with a single channel CE system with post-column sheath flow detection allows detection limits for serotonin and tryptophan of 3.9×10-8 M and 4.5×10-8 M respectively. Single cell analysis of serotonergic metacerebral cells from the sea slug Aplysia californica yields a value of 800±85 fmol of serotonin in each cell soma. For the first time, serotonin is directly detected in electrically stimulated release from single metacerebral cell soma, with approximately 4% of the serotonin contained in the soma released from a semi-intact preparation with a 2 min electrical stimulation. 相似文献
59.
YanXiaCAO MiaoDU QiangZHENG 《中国化学快报》2004,15(5):567-570
The study on rheological properties of a series of mica-filled polypropylene (PP) composites was carried out. The influence of surface-treatment of mica particles on dynamic rheological behavior of the composites were dealt with. The viscosity (η) and dynamic modulus ( G‘ ) of the composite melts were higher than those of PP matrix, especially those for systems treated with silane, which was attributed to the interfacial adhesion enhancement. However, surface-treatment of mica by titanate resulted in lower η and G‘, as compared with the treatment by silane. The reason for this is believed to be the formation of the mono-molecular layer on the mica surface. 相似文献
60.
The effect of pH on the adsorption of anionic dye Titan yellow on the activated carbon from aqueous solution has been studied. It has been found that the Zeta potential of the activated carbon has a great effect on adsorption capacity of Titan yellow. The kinetic and the thermodynamic parameters of adsorption as a function of pH has been evaluated. The mechanism for adsorption of anionic dye Titan yellow on the activated carbon has also been discussed. 相似文献