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排序方式: 共有109条查询结果,搜索用时 31 毫秒
31.
The design, fabrication, and testing of photoelastic models of double-lap, multiple-pin connectors are discussed. Interest
is in the stresses in the inner laps. These stresses are determined by constructing models with photoelastic inner laps and
transparent-acrylic outer laps. The connectors have two pins, in tandem, parallel to the load direction. A photoelastic-isotropic
point is shown to permit the evaluation of load sharing between the two pins. A numerical scheme, utilizing the isochromatic-
and isoclinic-photoelastic data and a finite-difference representation of the planestress equilibrium equations, is used to
compute the stresses around the two pins. Representative stress distributions and stress-concentration factors are shown. 相似文献
32.
P.V. Chliapnikov P.A. Gorbunov S.A. Gumenyuk V.V. Kniazev B.A. Manyukov V.M. Perevoztchikov V.N. Riadovikov V.A. Uvarov M.L. Faccini-Turluer M. Loret L. Mosca H. Blumenfeld J. Laberrigue C. Dujardin F. Grard J. Skura R. Windmolders M. Csejthey-Barth M. Gysen 《Nuclear Physics B》1977,131(1):93-106
A study of the inclusive and semi-inclusive Λ and production in K+p interactions at 32 GeV/c is presented. The inclusive cross sections for Λ and amount to 0.78 ± 0.05 and 0.42 ± 0.04 mb thus showing a remarkable growth between 16 and 32 GeV/c with a factor of 1.7 for Λ and 2.8 for . Target and beam fragmentation processes are found to be dominant for Λ and production respectively with the following lower limits for the corresponding cross sections: and . Although the early scaling conditions are fulfilled for the Λ production in the target fragmentation region, and production in the beam fragmentation region, scaling is not observed between 16 and 32 GeV/c in the x and pT2 Feynman variables. The Λ production is found to be very similar in the K+p inclusive reaction at 32 GeV/c and in the semi-inclusive reaction at the same energy. The pair production cross section increases significantly in K+p interactions from 16 to 32 GeV/c where it reaches the value . The cross sections for Λ or produced in association with an identified proton are also given and discussed. 相似文献
33.
I. V. Ajinenko Y. A. Belokopitov P. V. Chliapnikov V. P. Falaleev A. B. Fenyuk L. N. Gerdyukov A. I. Kurnosenko A. M. Rybin E. A. De Wolf J. J. Dumont M. Gysen M. Van Immerseel F. Grard J. Hanton J. Laberrigue H. K. Nguyen C. Cochet M. L. Faccini-Turluer L. Mosca France-Soviet Union Collaboration CERN-Soviet Union Collaboration 《Zeitschrift fur Physik C Particles and Fields》1980,4(3):181-199
Final data on topological cross sections are presented. Inclusive single particle distributions for the reactionsK + p→ π± X at 32 GeV/c are discussed and compared with data at lower energies. Early scaling in the fragmentation regions is confirmed, while cross sections in th central region continue to rise with energy even faster than inpp interactions. Thex-andp T -dependence of the π+/π? ratio inK + p interactions is discussed and a comparison of reactionsK + p→ π± X andK ? p→ π± X at 32 GeV/c is made in the context of constituent models. We also present transverse momentum distributions, show prominent seagull effects and study how they are influenced by resonance production. 相似文献
34.
C. Lewin D. Denegri A. Givernaud M. Loret L. Mosca J. Saudraix H. Grässler J. Klugow U. Kriegel M. Walter E. De Wolf F. Verbeure D. R. O. Morrison F. A. Triantis C. Dujardin F. Grard Yu. Arestov M. Boglyubsky V. Bumazhnov P. V. Chliapnikov V. M. Perevoztchikov A. P. Vorobjev H. Dibon France-Soviet Union Collaboration CERN-Soviet Union Collaboration 《Zeitschrift fur Physik C Particles and Fields》1980,3(4):275-284
Results are presented onK + p andK ? p elastic scattering at 32.1 GeV/c in the |t| interval 0.06–1.4 GeV2. The samples contain approximately 15,000 events each and are obtained in the MIRABELLE bubble chamber at the Serpukhov accelerator. The |t| distributions are parametrized by quadratic exponential formsdσ/dt=A exp (bt+ct 2). The total elastic cross sections, obtained by integrating the fitted distributions, are (2.39±0.07) mb and (2.57±0.10) mb inK + p andK ? p interactions, respectively. A cross-over between theK + p andK ? p differential cross sections is found at |t c |=0.17±0.02 GeV2. The hypothesis of geometric scaling becomes valid somewhere between 32 and 70 GeV/c forK + p interactions, and is trivially verified forK ? p scattering. Finally, an impact parameter analysis of the difference betweenK ? p andK + p elastic amplitudes is presented. 相似文献
35.
P. Caruso G. Graziani A. Martilli S. Mosca M. T. Pareschi M. Valenza 《Il Nuovo Cimento C》1996,19(2):195-214
Summary A set of measurements from various sources was collected for the Island of Vulcano (Aeolian Archipelago, South Tyrrhenian
Sea) during summer 1994 with the scope of characterising the circulation pattern and the CO2 natural volcanic emission of the island. Ground meteorological stations were activated, wind profiles from pilot balloons
were obtained, ground temperature measurements were produced. Furthermore, temperature and humidity data from satellite (Landsat
TM) were also derived. A critical analysis of the data on the gathered information was performed to quantify the volcanic
risk related to the toxic-volcanic-gas release in foreseeable paroxysmal events. 相似文献
36.
37.
Zs. J. Horvth P. Frigeri S. Franchi Vo. Van Tuyen E. Gombia R. Mosca L. Dzsa 《Applied Surface Science》2002,190(1-4):222-225
Excess current was obtained in GaAs/InAs quantum dot structures at low temperatures and low current levels. This excess current exhibited instabilities with changing the bias, and over the time. It has been concluded that the excess current is a minority injection current connected with recombination through defects originated from the formation of QDs. The instabilities are connected with unstable occupation of energy levels induced by the above defects, which depend on temperature and on the current level. 相似文献
38.
Structured adsorbents in the form of supported thin zeolite films may represent a competitive alternative to traditional zeolite adsorbents in form of beads or pellets used in PSA processes, due to the reduction of mass- and heat-transfer limitations typical of packed beds. Thin NaX films were grown by hydrothermal treatment using a clear solution on cordierite monoliths. Films grown by a multiple synthesis procedure were dense and uniform with a very small amount of sediments adjacent to the film, which may be an advantage in PSA applications. The CO2 adsorption capacity and the pressure drop for the supported films were compared to those of a packed NaX bed. Although the adsorption capacity of the column filled with the structured adsorbents was 67 times lower than when the column was filled with zeolite beads, the pressure drop was 100 times lower for the structured adsorbent. The adsorption capacity can be increased by increasing the film thickness or the cell density of the monoliths without increasing the pressure drop significantly, indicating the potential advantage of structured adsorbents in PSA processes. Further investigations are needed in order to prove this hypothesis. 相似文献
39.
Catherine Paradis-Bleau Adrian Lloyd François Sanschagrin Tom Clarke Ann Blewett Timothy DH Bugg Roger C Levesque 《BMC biochemistry》2008,9(1):33
Background
To develop antibacterial agents having novel modes of action against bacterial cell wall biosynthesis, we targeted the essential MurF enzyme of the antibiotic resistant pathogen Pseudomonas aeruginosa. MurF catalyzes the formation of a peptide bond between D-Alanyl-D-Alanine (D-Ala-D-Ala) and the cell wall precursor uridine 5'-diphosphoryl N-acetylmuramoyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid (UDP-MurNAc-Ala-Glu-meso-A2pm) with the concomitant hydrolysis of ATP to ADP and inorganic phosphate, yielding UDP-N-acetylmuramyl-pentapeptide. As MurF acts on a dipeptide, we exploited a phage display approach to identify peptide ligands having high binding affinities for the enzyme. 相似文献40.
Mosca A Paleari R Galanello R Sollaino C Perseu L Demartis FR Passarello C Giambona A Maggio A;IFCC Working Group on Standardization of HbA 《Bioelectrochemistry (Amsterdam, Netherlands)》2008,73(2):137-140
The increase of HbA(2) is the most important feature in the identification of beta-thalassemia carriers. However, some carriers are difficult to identify, because the level of HbA(2) is not in the typical range. Few data are available concerning the prevalence of such unusual phenotypes, and knowing their expected prevalence could be helpful in detecting systematic drifts in the analytical systems for HbA(2) quantification. In this study we report a retrospective investigation in two centres with high prevalence of beta-thalassemia. The prevalence of borderline subjects was found to be 2.2 and 3.0%, respectively. The genotypes of a subgroup of these subjects were then analyzed and in about 25% of cases a mutation in the globin genes was identified. We conclude that the occurrence of HbA(2) borderline phenotypes is not a rare event. In order to obtain more accurate HbA(2) measurements the development of an international reference measurement system for HbA(2), based on quantitative peptide mapping, has been recently started. We believe that the innovative approach of our method could also be used as a model to develop accurate quantitative methods for other red cell proteins relevant to the biodynamic properties and the surface electrochemistry of erythrocytes. 相似文献