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排序方式: 共有415条查询结果,搜索用时 15 毫秒
41.
Jiri A. Mares Martin Nikl Alena Beitlerova Karel Blazek Petr Horodysky Karel Nejezchleb Carmelo D’Ambrosio 《Optical Materials》2011,34(2):424-427
Scintillation properties of Pr3+-doped LuAG and YAG crystals were investigated and compared with those of Ce3+-doped ones. The highest L.Y.’s were observed with the longest shaping time 10 μs. They can reach up to ~16,000 ph/MeV or ~23,500 ph/MeV for LuAG:Pr and LuAG:Ce, respectively. Energy resolutions (FWHM) are a bit better with LuAG:Pr than those of LuAG:Ce, e.g. at 662 keV FWHM are around 6% and between 8–12%, respectively. There were observed no large changes in proportionality of Pr3+- or Ce3+-doped LuAG or YAG crystals but the best proportionality has YAP:Ce crystal. Pr3+- or Ce3+-doped LuAG crystals exhibit slow decay components in the time range 1.5–3.5 μs while those of YAG ones have shorter decay components between 0.3–1.7 μs. 相似文献
42.
A cold physical model to a scale of 1:33 of a solid waste incinerator was designed and constructed of transparent material. Experimentation aimed at optimizing gas flow patterns in the furnace for low-pollutant combustion. Flames were simulated by acid-base neutralization. Secondary air flow distribution and direction were identified as the controlling parameters of the flow pattern. The best possible air distribution for a desired flame shape and gas mixing was determined. Streamline plots for verification of the mathematical models were obtained. 相似文献
43.
A short review of the works concerning parameter estimation in kinetic experiments was performed. An adaptive random search algorithm was applied to evaluate the parameters and parameter confidence intervals of Langmuir-Hinshelwood models. The kinetic parameters were determined using the Box - Draper criterion. The parameter confidence regions were found by using the likelihood ratio. Three heterogeneously catalyzed hydrogenations were studied. 相似文献
44.
45.
Martina Stekrova Hana Minarikova Eliska Vyskocilova Jiri Kolena Libor Cerveny 《Journal of Porous Materials》2014,21(5):757-767
The presented report focuses on the testing of heterogenized methyltrioxorhenium (MTO) in indene epoxidation. A range of mesoporous materials with different SiO2/Al2O3 ratios, namely aluminosilicates type Siral and MCM-41 silica and fumed silica, were used as supports for immobilization of MTO. The tested support materials and prepared catalytic systems exhibited high surface area, well-defined regular structure and narrow pore size distribution of mesopores and therefore represent good quality catalysts for various reactions. The immobilized MTO on various supports was tested for the preparation of 1,2-epoxyindane using two forms of hydrogen peroxide as oxidation agents, namely aqueous solution of hydrogen peroxide and its anhydrous form, urea-hydrogen peroxide. The prepared catalysts were successfully used for the preparation of 1,2-epoxyindane with achieved 100 % selectivities to the desired product at high conversions of indene. 相似文献
46.
Alexander Pyattaev Jiri Hosek Kerstin Johnsson Radko Krkos Mikhail Gerasimenko Pavel Masek Aleksandr Ometov Sergey Andreev Jakub Sedy Vit Novotny Yevgeni Koucheryavy 《ETRI Journal》2015,37(5):877-887
This paper is a first‐hand summary on our comprehensive live trial of cellular‐assisted device‐to‐device (D2D) communications currently being ratified by the standards community for next‐generation mobile broadband networks. In our test implementation, we employ a full‐featured 3GPP LTE network deployment and augment it with all necessary support to provide real‐time D2D connectivity over emerging Wi‐Fi‐Direct (WFD) technology. As a result, our LTE‐assisted WFD D2D system enjoys the required flexibility while meeting the existing standards in every feasible detail. Further, this paper provides an account on the extensive measurement campaign conducted with our implementation. The resulting real‐world measurements from this campaign quantify the numerical effects of D2D functionality on the resultant system performance. Consequently, they shed light on the general applicability of LTE‐assisted WFD solutions and associated operational ranges. 相似文献
47.
Die Bestimmung des Grenzumformgrades eines Stahles, der während der plastischen Verformung nicht überschritten werden kann, ist von großer Bedeutung. Die vorliegende Arbeit berichtet über Ergebnisse von Warmtorsionsversuchen, aus denen der Grenzumformgrad als Funktion von Temperatur und Umformgeschwindigkeit ermittelt wurde. Die Versuche wurden an den Stählen X 10 CrNiTi 18 9, 10 CrMo 9 10, X 10 CrNiMoTi 18 12, X 20 CrMoV 12 1 und X 2 NiCrNb 25 18 durchgeführt. 相似文献
48.
Cheng He Jiri Marsalek Quintin Rochfort Bommanna G. Krishnappan 《Canadian Metallurgical Quarterly》2006,132(2):131-139
The performance of a combined sewer overflow (CSO) storage/treatment facility in North Toronto, Ont., Canada, was investigated by conjunctive numerical and physical (hydraulic) modeling. The main objectives of the study were to (1) assess the feasibility of increasing the hydraulic loading of the CSO facility without bypassing; and (2) establish a verified numerical model of the facility for future work. The numerical model [a commercial computational fluid dynamics (CFD), PHOENICS] was validated and verified using results from a hydraulic scale model (1:11.6). The results obtained show that the CFD model can simulate hydraulic conditions in the facility well, as demonstrated by accurate reproduction of the filling rate, water levels at various locations, flow velocities in feed pipes, and overflows from the inflow channel. Numerical simulations identified excessive local head losses and helped select structural changes to reduce such losses. The analysis of the facility showed that with respect to hydraulic operation, the facility is a complex, highly nonlinear hydraulic system. Within the existing constraints, a few structural changes examined by numerical simulation could increase the maximum treatment flow rate in the CSO storage/treatment facility by up to 31%. 相似文献
49.
S Roman-Unfer JD Bitran L Garrison C Proeschel S Hanauer L Schroeder L Johnson L Klein J Martinec 《Canadian Metallurgical Quarterly》1996,24(7):823-828
Fourteen patients with stage II-IV breast cancer were enrolled in a phase II study of cyclophosphamide followed by PIXY321 as a means of mobilizing peripheral blood progenitor cells (PBPC). All 14 women tolerated PIXY321 well, with the predominant toxicities being erythema at the injection site, fever, and arthralgias. A median of two aphereses yielded a mean of 1.3 x 10(8) mononuclear cells/kg, 8.9 x 10(4) colony-forming units-granulocyte/macrophage (CFU-GM)/kg, and 4.5 x 10(6) CD34+ cells/kg. All 14 patients underwent high-dose chemotherapy with PBPC support, the median day to ANC >500 cells/microliter was 10.6, and the median day to platelets >20,000 cells/microliter was 13. The day of 90th percentile platelet recovery was 15. When compared to PBPCs mobilized by cyclophosphamide followed by GM-CSF, the use of PIXY321 may confer an advantage of enhanced platelet recovery. 相似文献
50.
Jiri Kriz 《Performance Evaluation》1984,4(1):1-10
Analytical lower and upper bounds for the throughput of closed queueing networks with single and delay (infinite) servers are studied in this paper. The numerical evaluation of these bounds requires a small number of significant operations which is independent of the population N. This is in contrast to the exact computation of the throughput which requires at least O(N) operations as N tends to infinity. The bounds are given by simple closed-form analytical expressions and may be more suitable for various performance studies than the algorithmical form of the exact solution.In this paper, the previously known balanced-job bounds are generalized to networks containing delay servers (terminals) and a hierarchy of bounds is obtained for single and multiple class networks. For the single class network, further new bounds are derived: lower and upper bounds that require the evaluation of one square root and an upper bound that requires a constant number of exponentiations. This upper bound does not employ the balancing of server loadings and is especially useful for asymptotic analysis in the case of a large number of customers N. 相似文献