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991.
JF McCarthy DJ Cook MG Massad Y Sano KJ O''Malley NR Ratliff RW Stewart NG Smedira RC Starling JB Young PM McCarthy 《Canadian Metallurgical Quarterly》1998,14(2):197-200
28 isolates of canine parvovirus type-2 (CPV-2) were obtained from dogs with hemorrhagic gastroenteritis in Italy. The antigenic structure of CPV-2 isolates was characterized, using four discriminating monoclonal antibodies. In addition, four vaccinal strains were examined. Similar to reports from Australia and the United Kingdom, a much higher prevalence of CPV-2a (25/28 isolates) was observed than the other variant type, CPV-2b (3/28 isolates). DNA fragments (2.2 kbp) of representative strains of CPV-2, CPV-2a and CPV-2b were amplified by the polymerase chain reaction (PCR) and the products were digested by the restriction enzymes (RE) RsaI, HpaII, HindIII and PvuII. The RvaI enzyme allows the differentiation of CPV-2 from CPV-2a and CPV-2b. 相似文献
992.
Microstructure and fracture toughness of nickel particle toughened alumina matrix composites 总被引:4,自引:0,他引:4
Al2O3-Ni composite materials have been made by a hot pressing technique. Two composite microstructures, i.e. a dispersive distribution of nickel particles and a network distribution of nickel particles in an alumina matrix, have been produced. The fracture toughness of the composite materials has been measured by a double cantilever beam method. Both composites are tougher than the virgin alumina matrix. The fracture toughness of the composite with a network microstructure is much higher and has a more desirable R-curve behaviour than the composite with a microstructure of dispersed particles. For the particulate dispersion microstructure, the main limitation to toughening is the lack of plastic deformation of the ductile nickel due to the pull out of nickel particles, indicating weak bonding at the Al2O3/Ni interface. For the network microstructure composite, the gauge length of the ductile phase is much larger, allowing the ductile nickel to stretch to failure between the crack faces. A large extent of nickel plastic deformation has been observed, and the weak bonding at the Al2O3/Ni interface can promote partial debonding and contribute further to toughening. 相似文献
993.
We used the fluorescent labelled dopamine D1-receptor antagonist Bodipy-SCH 23390 for the cellular localization of D1-ligand binding sites in the retinae of different vertebrates (teleosts, Xenopus, turtle, rat and rabbit). Competition experiments with unfixed cryosections of fish retina were performed to characterize the binding conditions of Bodipy-labelled SCH 23390. Tissue bound [3H]SCH 23390 was displaceable with increased amounts of bodipy-SCH 23390. The pharmacological specificity of the D1 fluorescent antagonist was determined by competition experiments with an excess of unlabelled SCH 23390. This treatment significantly reduced the level of fluorescence of the retina confirming the specificity of the binding. We observed a homogeneously distributed fluorescence signal in both plexiform layers in unfixed cryosections of fish, frog, turtle, rat and rabbit. Similar staining intensities of both plexiform layers were found in frog, turtle, rat and rabbit retina. In teleosts, the label of the outer plexiform layer was markedly more intense. Non-specific label was associated with photoreceptor outer and inner segments. The specific labelling of both plexiform layers indicates a mismatch of dopamine releasing and D1-binding sites, and suggests a possible extrasynaptic localization of the D1-receptor. The physiological significance of the observed distribution of D1-ligand binding sites is discussed with respect to the role of dopamine in controlling adaptational processes in the retina. 相似文献
994.
A.MT.3000断面测量系统及其在二滩水电工程中的应用证明,该系统简比了断面测量方法,能有效地提高工作效率,在水电等工程建设中具有明显的经济效益。 相似文献
995.
996.
影响DT岩石粉状铵梯炸药爆速的因素探索 总被引:1,自引:1,他引:0
文章从DT岩石粉状铵梯炸药的原材料细度,复合油相,混药时间,投料顺序,混药药温,装药密度等方面,探讨了该炸药爆速的影响因素。 相似文献
997.
Yoo‐Seong Kim Woong‐Sik Kim Hak‐Nyun Choi Tae‐Geum Koh Yong‐Seog Kim 《Journal of the Society for Information Display》2007,15(3):199-204
Abstract— Among various barrier‐rib manufacturing processes, the mold‐pattern‐transfer method has potential to reduce processing cost as well as the manufacture of high‐resolution pixels. In this study, the effects of major processing variables of the mold‐pattern‐transfer process on the formation of air‐trapped pores within barrier ribs were examined. The results indicated that with an optimum combination of the processing variables, barrier ribs without trapped defects can be produced, demonstrating the possibility of reducing the number of processing steps and costs of barrier ribs. 相似文献
998.
Using the CALPHAD (Calculation of Phase Diagram) technique, the DyCl3-MCl (M = Na, K, Rb, Cs) systems were optimized and calculated. The modified quasi-chemical model in the pair approximation for short-range ordering was used to describe the Gibbs energies of the liquid phase in these systems. From the measured phase diagram data and experimental thermodynamic properties, a series of thermodynamic functions were optimized base on an interactive computer-assisted analysis. The optimized parameters and the experimental data were thermodynamically self-consistent. The optimized results were discussed. 相似文献
999.
A new physics analysis procedure has been developed for a prismatic very high temperature gas-cooled reactor based on a conventional two-step procedure for the PWR physics analysis. The HELIOS and MASTER codes were employed to generate the coarse group cross sections through a transport lattice calculation, and to perform the 3-dimensional core physics analysis by a nodal diffusion calculation, respectively. Physics analysis of the prismatic VHTRs involves particular modeling issues such as a double heterogeneity of the coated fuel particles, a neutron streaming in the coolant channels, a strong core-reflector interaction, and large spectrum shifts due to changes of the surrounding environment and state parameters. Double heterogeneity effect was considered by using a recently developed reactivity-equivalent physical transformation method. Neutron streaming effect was quantified through 3-dimensional Monte Carlo transport calculations by using the MCNP code. Strong core-reflector interaction could be handled by applying an equivalence theory to the generation of the reflector cross sections. The effects of a spectrum shift could be covered by optimizing the coarse energy group structure. A two-step analysis procedure was established for the prismatic VHTR physics analysis by combining all the methodologies described above. The applicability of our code system was tested against core benchmark problems. The results of these benchmark tests show that our code system is very accurate and practical for a prismatic VHTR physics analysis. 相似文献
1000.
Tianxi Sun 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2007,262(1):153-156
An energy dispersive micro X-ray diffractometer based on a combined system of two polycapillary X-ray lenses is designed. The polycapillary X-ray lens in the excitation channel is either a polycapillary parallel X-ray lens (PPXRL) or a slightly focusing polycapillary X-ray lens (SFPXRL). The polycapillary X-ray lens in the detection channel is a PPXRL. At 6.4 keV and 2θ = 141.5°, the total resolution of the diffractometer based on a SFPXRL in the excitation channel and a PPXRL in the detection channel in Δd/d is 4.8%. 相似文献