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111.
Meraz Mónica González-Barrera Alfonso Alvarez-Ramirez José Monroy Oscar 《Applied biochemistry and biotechnology》1996,57(1):525-534
Applied Biochemistry and Biotechnology - In this article, a study of the dynamics of the immobilization of mesophilic anaerobic bacteria was conducted. Low-density polyethylene (LDPE) ground to... 相似文献
112.
113.
The title compounds 1b and 1c were synthesized from manool. On treatment with either trifluoroacetic acid or formic acid 1b provided in nearly 100% yield 4a with a rearranged labdane skeleton. With sulfuric acid, however, 1b gave solely Δ8,9-isomer 5. Reduction of 4a with lithium diisobutylaluminum hydride afforded 4b. On treatment with sulfuric acid 4a reverted to 5. Rearrangement of the epoxide 6 with boron trifluoride- etherate led to a complex product mixture from which no pure substance was obtained. 相似文献
114.
Ohne Zusammenfassung 相似文献
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116.
Sebastian Munoz-Guerra Jose Maria Fernandez-Santin Alfonso Rodriguez-Galan Juan A. Subirana 《Journal of Polymer Science.Polymer Physics》1985,23(4):733-742
The structure and morphology of crystalline nylon 3 [poly(β-alanine)] have been studied by electron microscopy and x-ray diffraction. Two clearly defined forms are detected. Form I appears as spherulites made up of ribbonlike lamellae upon crystallization at high temperature from a solution in phenol–butanediol-1,4. They have monoclinic unit cell with a = 9.60 Å, c = 8.96 Å, and β = 122.5°. The hydrogen-bonded planes run parallel to the long dimension of the crystals. Form II is observed when the samples are prepared from formic acid solution at room temperature. A second type of spherulite with a microfibrillar structure is formed in this case. The isolated crystalline structures obtained from Form II appear to grow along the intersheet direction rather than along the hydrogen bond direction, which constitutes anomalous behaviour. Our results for this second form are consistent with an orthorhombic lattice with a = 9.56 Å and c = 7.56 Å. No clear information is obtained on the b dimension of the unit cell (chain axis) in either case. We assume a value of 4.78 Å, which corresponds to fully extended chains. The two forms coexist in films prepared from a formic acid–water solution as well as in samples recovered immediately after polymerization. 相似文献
117.
Bubbling in unbounded coflowing liquids 总被引:1,自引:0,他引:1
An investigation of the stability of low density and viscosity fluid jets and spouts in unbounded coflowing liquids is presented. A full parametrical analysis from low to high Weber and Reynolds numbers shows that the presence of any fluid of finite density and viscosity inside the hollow jet elicits a transition from an absolute to a convective instability at a finite value of the Weber number, for any value of the Reynolds number. Below that critical value of the Weber number, the absolute character of the instability leads to local breakup, and consequently to local bubbling. Experimental data support our model. 相似文献
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González-Alvarez A Alfonso I Díaz P García-España E Gotor V 《Chemical communications (Cambridge, England)》2006,(11):1227-1229
The highly enantioselective molecular recognition of the malate dianion by a synthetic receptor in aqueous solution has been studied by potentiometric titrations, mass spectrometry (ESI-MS), diffusion measurements (PGSE NMR) and molecular modeling. 相似文献
120.
González-Alvarez A Alfonso I Gotor V 《Chemical communications (Cambridge, England)》2006,(21):2224-2226
Cadmium promoted diastereoselective amplification of a single member from a dynamic combinatorial library of stereoisomeric oligoimines of different sizes allows the efficient preparation of a new macrocyclic polyamine. 相似文献