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101.
The polymerization kinetics of acrylamide (AAM) in water initiated by a ternary enzymatic system of horseradish peroxidase (HRP)/H2O2/acetylacetone (ACAC) was investigated. Conversion–time plots were obtained by dilatometry under different conditions of reaction temperatures and initial concentrations of HRP, ACAC, H2O2, and AAM. The results showed that the effect of the initial concentration of ACAC on the inhibition period was significant. The inhibition period decreases with increasing the initial concentration of ACAC. The inhibition period can be even eliminated by the use of a comparatively large amount of ACAC. From the conversion–time plots, the polymerization rate equation was obtained. Some kinetic features were explained on the basis of analysis of the reaction mechanism. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 475–481, 2012 相似文献
102.
We prove that the moduli space of regular stable maps in a complex manifold admits a natural complex orbifold structure. Our
proof is based on Hardy decompositions and Fredholm intersection theory.
The authors would like to thank the referee for his/her diligent work. We are grateful for the careful attention to detail
in the report. 相似文献
103.
104.
Isolation of Phosphate-Solubilizing Fungi from Phosphate Mines and Their Effect on Wheat Seedling Growth 总被引:1,自引:0,他引:1
Chunqiao Xiao Ruan Chi Huan He Guanzhou Qiu Dianzuo Wang Wenxue Zhang 《Applied biochemistry and biotechnology》2009,159(2):330-342
Three phosphate-solubilizing fungi, identified as Penicillium expansum, Mucor ramosissimus, and Candida krissii, were isolated from phosphate mines (Hubei, People’s Republic of China) and characterized. All the isolates demonstrated
diverse levels of phosphate-solubilizing capability in National Botanical Research Institute’s phosphate growth medium containing
rock phosphate as sole phosphate source. Acidification of culture medium seemed to be the main mechanism for rock phosphate
solubilization. Indeed, citric acid, oxalic acid, and gluconic acid were shown to be present in the culture medium inoculated
with these isolates. Moreover, the isolates produced acid and alkaline phosphatases in culture medium, which may also be helpful
for RP solubilization. A strong negative correlation between content of soluble phosphorus and pH (r = – 0.89; p < 0.01) in culture medium was observed in this study. All the isolates promoted growth, soil available phosphorus, phosphorus,
and nitrogen uptake of wheat seedling in field soil containing rock phosphate under pot culture conditions, thus demonstrating
the capability of these isolates to convert insoluble form of phosphorus into plant available form from rock phosphate, and
therefore hold great potential for development as biofertilizers to enhance soil fertility and promote plant growth. 相似文献
105.
106.
Ding-Shan Ruan Ya-Li Li Lei Wang Dong Su Feng Hou 《Journal of Sol-Gel Science and Technology》2010,56(2):184-190
Spinnable solutions are obtained in the sol–gel system of tetraethoxide (TEOS, Si(OC2H5)4) and vinyltrimethoxysilane (VTMS, CH2=CHSi(OCH3)3) under aqueous condition (water) with acid catalysts (HNO3 and HCl). Polysiloxane (PSO) fibers are drawn from the solution and characterized by spectroscopic and structural analyses.
29Si-nuclear magnetic resonance NMR) spectral analysis of the PSO fiber indicates the incorporation of atomic carbon in the
silica network. 13C-NMR analysis shows the existence of considerable amount of hydroxyl groups in the PSO fiber. The spinnablity of the solution
is studied by varying the mole ratios of the alkoxides, solvents and catalysts as well as precursor chemistries. The amount
of water and catalysts are found to be important for the attaining of a spinnable state in the solution. SiOC fibers are obtained
after pyrolysis of the PSO fibers with a high ceramic yield (88 wt%). The high ceramic yield attributes to the incorporation
of vinyl-groups in the gel fiber that enhances crosslinking during pyrolysis. The SiOC fiber has a tensile strength of 776 MPa
and electrical conductivity of 3.6 × 10−4 S/m. 相似文献
107.
108.
We use a Monte Carlo method to study the phase and interfacial behaviors of A-b-B diblocks in a blend of homopolymers, A and B, which are confined between two asymmetric hard and impenetrable walls. Our results show that, when the interaction strength is weak, the block copolymersare uniformly distributed in the ternary mixtures under considered concentrations. Under strong interaction strength, distribution region of the block copolymers changes from a single smooth interface to a curved interface or multi-layer interface in the ternary mixtures. Furthermore, our findings show that with increasing volume fraction of A-b-B diblock copolymer(фC), copolymer profiles broaden while фC≥ 0.4, a lamellar phase is formed and by further increasing фC, more thinner layers are observed. Moreover, the results show that, with the increase of фC, the phase interface first gradually transforms from plane to a curved surface rather than micelle or lamellar phase while with the increase of the interaction between A and B segments(ε_(AB)), the copolymer chains not only get stretched in the direction perpendicular to the interface, but also are oriented. The simulations also revealthat the difference between symmetric and asymmetric copolymers is negligible in statistics if the lengths of two blocksare comparable. 相似文献
109.
Two novel asymmetric salen ligands H2L1 [N‐phenyl‐N‐(2‐hydroxy‐5‐methylphenyl)‐N′‐(2‐hydroxy‐3‐meth‐ oxylphenyl)‐o‐phenyldiamine] and H2L2 [N‐phenyl‐N‐(2‐hydroxy‐5‐chlorophenyl)‐N′‐(2‐hydroxy‐3‐methoxyl‐ phenyl)‐o‐phenyldiamine] and their metal complexes MLn (M=Zn, Co, Ni, Cu; n=1, 2) have been prepared and characterized by elemental analyses, 1H NMR, ESI‐MS, FT‐IR and UV‐Vis spectra. In particular, the complex ZnL1, the binuclear monosalphen complex, was synthesized and studied in detail using 1H NMR and ESI‐MS techniques. For other metal complexes under the same reaction conditions, only mononuclear complexes were obtained. The results are relevant to both the metal ions and the structure of ligands. 相似文献
110.