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101.
The use of compressive crushing equipment such as gyratory crushers within minerals processing plants can potentially generate large quantities of dust. Remedies to this problem include the retrofitting of shrouds, enclosures, local exhaust ventilation (LEV) systems and water suppression systems. The single or combined application of these systems must be optimised to ensure they operate efficiently. It is desirable that the future design planning of such facilities include integrated dust suppression and/or removal systems to ensure material delivery rates are maintained and the welfare of the workforce is protected. 相似文献
102.
《Tetrahedron: Asymmetry》2006,17(19):2726-2729
Several thioaryl- and phosphino-phosphoramidite ligands have been synthesized from commercially available β-aminoalcohols. This new family of bidentate ligands are highly active in the enantioselective copper-catalyzed conjugate addition of diethylzinc to both cyclic and acyclic enones showing moderate to good enantiomeric excesses of up to 81%. 相似文献
103.
《Solid State Ionics》2006,177(19-25):1635-1637
This work shows how the combination of quasi-equilibrium (chronopotentiometry) and kinetical measurements (electrochemical impedance) is able to extract ionic mobility values like the jump diffusion coefficient DJ. Results are presented on the jump diffusion coefficient variation with composition of several cations (Li+, Na+, and K+) intercalated into electron beam evaporation-prepared a-WO3 thin films. DJ exhibits higher values for the smallest ion (Li+), and decreases as the ion size enlarges. In all cases DJ shows lower values for high intercalation levels. It is noted that the type of cation rather influences transport mechanisms than equilibrium properties (insertion thermodynamics). The energy barrier of ion hopping is analyzed in light of available microscopic diffusion models and theoretical simulations. 相似文献
104.
《The Journal of chemical thermodynamics》2006,38(8):1017-1024
Densities at T = (293.15, 298.15, 303.15, 308.15, and 313.15) K in the binary liquid mixtures of polyethylene glycol 300 with 2-ethoxyethanol, 2-(2-ethoxyethoxy)ethanol, or 2-{2-(2-ethoxyethoxy)ethoxy}ethanol have been measured over the entire range of mixture compositions. These data have been used to compute the excess molar volumes. The excess molar volumes are negative over the entire range of composition for all studied mixtures. The results are discussed in terms of intermolecular interactions in the bulk binary mixtures. 相似文献
105.
《Radiation Physics and Chemistry》2006,75(2):336-349
This paper describes the development of a calorimetry-based technique for monitoring of the curing of electron beam (EB) curable resins, including design of the calorimeter hardware and the development of an analytical model for calculating resin cure rates and radiation dose. Factors affecting the performance of the calorimeter were investigated. Experimental trials monitoring the curing of epoxy resin were conducted under single pass and multiple passes of EB irradiation. Results show that the developed calorimeter is a simple, inexpensive and reasonably accurate technique for monitoring the EB curing of cationic epoxies. 相似文献
106.
《Superlattices and Microstructures》2006,40(1):19-28
We study the variation of the gain and the differential gain for a quantum well laser based on the CdZnTe alloys. We calculate theoretically the optical gain of CdZnTe based quantum well laser, as function of the alloys composition for various values of carrier’s densities. Our study is based on the parabolic model with the intraband relaxation taken into account. Finally, we investigate how the composition alloys affects the differential gain of quantum well lasers. 相似文献
107.
《Discrete Applied Mathematics》2007,155(6-7):676-685
Position-specific score matrices (PSSMs) have been applied to various problems in computational molecular biology. In this paper, we study the following problem: given positive examples (sequences) and negative examples (sequences), find a PSSM which correctly discriminates between positive and negative examples. We prove that this problem is solved in polynomial time if the size of a PSSM is bounded by a constant. On the other hand, we prove that this problem is NP-hard if the size is not bounded. We also prove hardness results for deriving multiple PSSMs and related problems. 相似文献
108.
109.
Yang Yan-Zhao Liu Wen-Tao Han Jian Zeng Shan Sun Si-Xiu 《Journal of Radioanalytical and Nuclear Chemistry》2004,260(3):647-651
The kinetics and mechanism of uranium(VI) extraction from nitric acid solution by bis(octylsulfinyl)methane (BOSM) are studied
with the method of stationary interface cell. The effects of temperature, extractant and nitric acid concentrations are discussed.
The results showed that the extraction process is controlled by the following reaction: UO2(NO3)2 + BOSM(i)⇄k1
k-1UO2(NO3)2BOSM(i). The variation of enthalpy associated with the extraction is -22.1±2.1 kJ/mol.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
110.
Song Hyung Keun Lee Hwaung Choi Jae-Wook Na Byung-ki 《Plasma Chemistry and Plasma Processing》2004,24(1):57-72
Methane conversion using an electric discharge has been studied for many years. Recently, many research groups have developed high-frequency pulsed plasma reaction for methane conversion to higher hydrocarbons and synthesis gas. CO2 reforming of methane to synthesis gas has also attracted considerable interest as a method of utilization of the greenhouse gases, CO2 and CH4, which occupy most of man-made greenhouse gases. In this study, the influence of pulse form of applied voltage on methane and carbon dioxide conversions and product selectivity has been investigated using a cylindrical type DBD reactor. For this purpose, two kinds of power supply were compared, that is, AC power supply which has a high-frequency sinusoidal wave form, and AC pulse power supply which has modified AC pulse wave form. The conversions of methane and carbon dioxide were enhanced using pulsed plasma. The lower pulse width was more profitable economically. 相似文献