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131.
Yuanan Diao 《Journal of statistical physics》1994,74(5-6):1247-1254
It has been shown that the smallest knots on the cubic lattice are all trefoils of length 24. In this paper, we show that the number of such unrooted knots on the cubic lattice is 3496. 相似文献
132.
Reactor design and energy concepts for a plasma process of acetylene black production 总被引:1,自引:0,他引:1
Acetylene black can be produced from methane decomposition in a plasma reactor. Different types of plasma reactor are designed for this purpose and a parametric analysis of the system is made. Carbon yield in the reactor seems to be dependent on methane flow rate and plasma power. The results obtained from various types of material analysis of the product obtained show that in some conditions carbon produced under plasma has qualities similar to acetylene black obtained by classical processes. 相似文献
133.
Taranjeet Kaur Ravinder Kumar Wanchoo 《International journal of environmental analytical chemistry》2015,95(6):494-507
Photocatalytic degradation of propiconazole, a triazole pesticide, in the presence of titanium dioxide (TiO2) under ultraviolet (UV) illumination was performed in a batch type photocatalytic reactor. A full factorial experimental design technique was used to study the main effects and the interaction effects between operational parameters in the photocatalytic degradation of propiconazole in a batch photo-reactor using the TiO2 aqueous suspension. The effects of catalyst concentration (0.15–0.4 gL?1), initial pH (3–9), initial concentration (5–35 mg L?1) and light conditions were optimised at a reaction time duration of 90 min by keeping area/volume ratio constant at 0.919 cm2 mL?1. Photocatalytic oxidation of propiconazole showed 85% degradation and 76.57% mineralisation under UV light (365 nm/30 Wm?2) at pH 6.5, initial concentration 25 mg L?1 and constant temperature (25 ± 1 °C). The Langmuir–Hinshelwood kinetic model has successfully elucidated the effects of the initial concentration on the degradation of propiconazole and the data obtained are consistent with the available kinetic parameters. The photocatalytic transformation products of propiconazole were identified by using gas chromatography–mass spectrometry (GC/MS). The pathway of degradation obtained from mass spectral analysis shows the breakdown of transformation products into smaller hydrocarbons (m/z 28 and 39). 相似文献
134.
CB[n](n=6-8) is a family of synthetic macrocyclic host molecules composed of n glycoluril units, which can be employed as molecular reactor. N-phenyloxypropyl-N'-ethyl-4,4'-bipyridium (1) was designed to form a host-guest inclusion complex with CB[n](n=6-8), subsequently, the bromination reaction of 1 and its corresponding inclusion complexes was investigated in this work. In the case of 1/CB[8], the folded including mode is quite helpful to acquire 1-bormination product completely through intramolecular charge transfer (ICT), and CB[8] can provide a safe bromination environment for 1. 相似文献
135.
The low Reynolds number turbulent flow and mixing in a confined impinging jet reactor 总被引:1,自引:0,他引:1
Florian Schwertfirm Johannes Gradl Hans C. Schwarzer Wolfgang Peukert Michael Manhart 《International Journal of Heat and Fluid Flow》2007,28(6):1429-1442
Turbulent mixing takes an important role in chemical engineering, especially when the chemical reaction is fast compared to the mixing time. In this context a detailed knowledge of the flow field, the distribution of turbulent kinetic energy (TKE) and its dissipation rate is important, as these quantities are used for many mixing models. For this reason we conduct a direct numerical simulation (DNS) of a confined impinging jet reactor (CIJR) at Re = 500 and Sc = 1. The data is compared with particle image velocimetry (PIV) measurements and the basic flow features match between simulation and experiment. The DNS data is analysed and it is shown that the flow is dominated by a stable vortex in the main mixing duct. High intensities of turbulent kinetic energy and dissipation are found in the impingement zone which decrease rapidly towards the exit of the CIJR. In the whole CIJR the turbulence is not in equilibrium. The strong mixing in the impingement zone leads to a rapid development of a monomodal PDF. Due to the special properties of the flow field, a bimodal PDF is generated in cross-sections downstream the impingement zone, that slowly relaxes under relaminarising conditions. The time required for meso-mixing is dominating the overall mixing performance. 相似文献
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A poly (acrylamide-co-methylenebisacrylamide) (poly (AAm-co-MBA)) monolith was prepared by thermal polymerization in the 100 or 250 μm i.d. capillary. The monolithic support was activated by ethylenediamine followed by glutaraldehyde. Trypsin was then introduced to form an immobilized enzyme reactor (IMER). The prepared IMER showed a reliable mechanical stability and permeability (permeability constant K = 2.65 × 10−13 m2). With BSA as the model protein, efficient digestion was completed within 20 s, yielding the sequence coverage of 57%, better than that obtained from the traditional in-solution digestion (42%), which took about 12 h. Moreover, BSA down to femtomole was efficiently digested by the IMER and positively identified by matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). To test the applicability of IMER for complex sample profiling, proteins extracted from Escherichia coli were digested by the IMER and further analyzed by nanoreversed phase liquid chromatography-electrospray ionization-mass spectrometry (nanoRPLC-ESI-MS/MS). In comparison to in-solution digestion, despite slightly fewer proteins were positively identified at a false discovery rate (FDR) of ∼1% (333 vs 411), the digestion time used was largely shortened (20 s vs 24 h), implying superior digestion performance for the high throughput analysis of complex samples. 相似文献
140.
Sequential injection analysis systems have been extensively exploited in the last decades for the implementation of enzyme based assays aiming the evaluation of enzyme activity or the determination of specific analytes. The most prominent aspects of the automation of enzymatic assays in these systems are discussed in this review. Special attention is devoted to the mode of enzyme manipulation in homogeneous or heterogeneous media and to the comparison with batch and flow injection enzyme methodologies. The possibility of implementing strategies for the enhancement of selectivity in specific determinations is also addressed. The more recent trends in this field are discussed focusing mainly on the miniaturization resorting to the lab-on valve platform as well as on the bead injection concept. 相似文献