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21.
对5种国产复杂三维槽型刀片的断屑性能进行了试验研究,并对三维槽型结构要素的断屑机理及断屑特点进行了分析。 相似文献
22.
按照ISO3685-1977(E)对几种新型刀具材料进行了寿命对比试验,分析和探讨了刀具的磨损机理,并用回归分析方法得出了不同材料刀具的寿命方程,计算了刀具在不同切削速度下的寿命 相似文献
23.
VG Mel'nikov EA Andreeva LV Vlasova LG Besedina GP Stepanova IaB Be?kin OM Lesniak IE Koshelev 《Canadian Metallurgical Quarterly》1998,(7):21-23
The authors propose a comprehensive approach to laboratory diagnosis of seasonal transmissible infections, based on modern methods permitting etiological deciphering of disease. A universal diagnostic algorithm notably accelerated the laboratory diagnosis due to cutting the period between collection of material from a patient and consecutive screening for antibodies to agents of tick-borne encephalitis, Lyme disease, and California encephalitis. 相似文献
24.
Multicomponent complexes of piroxicam with cyclodextrins and hydroxypropyl methylcellulose 总被引:1,自引:0,他引:1
The purpose of the study was to investigate the effect of hydroxypropyl methylcellulose (HPMC) on the complexation of piroxicam (PX) with β-cyclodextrin (β-CD) and dimethyl-β-cyclodextrin (DM-β-CD) in solution and in the solid state. Phase solubility study revealed a positive effect of the polymer on the drug complexation. Improvement in stability constants values, Ks, of ternary complexes clearly proves the benefit of the HPMC addition for promoting higher complexation efficiency. Solid binary and ternary complexes were prepared by spray drying. Drug-CD and drug-CD-polymer interactions were studied in the solid state by differential scanning calorimetry (DSC), zeta-potential measurements, and particle size distribution. A marked increase in the PX dissolution rate was observed even in binary and ternary complexes. The presence of HPMC in ternary complexes slightly retarded the release of PX. Cyclodextrin complexation increased the PX concentration gradient over the semipermeable membrane, resulting in an increased PX flux. The retarded diffusion of PX to the membrane interface decreased the PX flux values of the ternary complexes. 相似文献
25.
In this article, a sufficient condition on the minimum dwell time that guarantees the stability of switched linear systems is given. The proposed method interprets the stability of switched linear systems through the distance between the eigenvector sets of subsystem matrices. Thus, an explicit relation in view of stability is obtained between the family of the involved subsytems and the set of admissible switching signals. 相似文献
26.
Unai De La Torre Beñat Pereda-Ayo Manuel Romero-Sáez Asier Aranzabal M. Pilar González-Marcos José A. González-Marcos Juan R. González-Velasco 《Topics in Catalysis》2013,56(1-8):215-221
The NOx NH3-SCR performance of several Cu and Fe catalysts supported on BETA and ZSM-5 zeolites has been studied in single SCR and double NSR–SCR configuration, and the activity related to the nature and reducibility of metal species on the catalyst surface. Intermediate ammonia formed in NSR improved greatly NOx conversion at the exit of the double NSR–SCR configuration, which was practically totally converted to N2. 相似文献
27.
M. Pilar González-Marcos Beñat Pereda Unai De La Torre Juan R. González-Velasco 《Topics in Catalysis》2013,56(1-8):352-357
The three-way activity under complex feed-streams of a series of Pt/Ce0.68Zr0.32O2 catalysts, either fresh or submitted to different ageing treatments, both before and after reduction, has been studied and related to the species present on the catalysts in view of their characteristics and TPR behaviour. 相似文献
28.
当今因为经济原因,为相应的织物选择正确的纱至关重要,连续的进料检验才能保证产品达到稳定满意的质量,清纱和纱疵分级系统在这方面扮演着重要的角色.清纱曲线的设置在电清刚开始问世时是很困难的,需要专家来解决. 相似文献
29.
Serap Pulatsü Akasya Topçu Mine Krkaaç Gülten Köksal 《Lakes & Reservoirs: Research and Management》2008,13(3):197-205
This study examined the vertical distributions of total phosphorus (TP) and phosphorus fractions, and the iron and organic matter, in the littoral sediment in a macrophyte‐dominated, clearwater state in Lake Mogan between September 2005 and August 2006. Benthic macroinvertebrates and total bacteria in the sediment also were determined. No clear seasonal or depth‐related (0–20 cm) patterns were found in sediment concentrations for the measured parameters. The phosphorus release was quantitatively very low, and a negative phosphorus release (–0.132 µg m?2 day?1) was measured during the summer months. The TP concentrations of the sediment samples ranged between 675.00 and 1463.80 µg g?1 dry weight (DW), and the trophic level of the lake was eutrophic. On average, inorganic phosphorus fractions comprised the largest fraction (63%), while organic‐bound phosphorus (Org ≈ P) constituted 37% of the TP in Lake Mogan. The most important phosphorus‐immobilizing factors are high iron content (14 200–47 750 µg g?1 DW), the sediment's clay content (47.80–51.80%), and an abundance of macrophytes at the sampling station. The low abundance of benthic macroinvertebrates (510–850 individuals m?2), which depend on sediments with high iron and low organic matter (5.42–13.30%), played a role in the sediment phosphorus retention. Although bacterial abundance in the surficial sediment appeared to be positively correlated to temperature, the overlying water did not experience anoxic conditions, supporting a state in which bacteria were able to retain phosphorus in their cell structures. Long‐term changes in the sediments of Lake Mogan must be monitored lake. In order to optimize the management of the lake, and to determine the longevity of a clearwater state following management measures and continued external phosphorus loading, long‐term changes in the sediments of Lake Morgan must be monitored. 相似文献
30.
Functional copolymer/organo‐silicate [N,N′‐dimethyldodecyl ammonium cation surface modified montmorillonite (MMT)] layered nanocomposites have been synthesized by interlamellar complex‐radical copolymerization of preintercalated maleic anhydride (MA)/ organo‐MMT complex as a ‘nano‐reactor’ with n‐butyl methacrylate (BMA) as an internal plasticization comonomer in the presence of radical initiator. Synthesized copolymers and their nanocomposites were investigated by dynamic mechanic analysis, X‐ray diffraction, SEM, and TEM methods. It was found that nanocomposite dynamic mechanical properties strongly depend on the force of interfacial MA … organo‐MMT complex formation and the amount of flexible n‐butyl ester linkages. An increase in both of these parameters leads to enhanced intercalation and exfoliation in situ processes of copolymer chains and the formation of hybrid nanocomposites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献