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Nuclear Modification to Parton Distribution Functions and Parton Saturation
Kang, Zhong-Bo;Qiu, Jian-Wei
High Energy Physics - Phenomenology , 2007, DOI: 10.1088/0954-3899/34/8/S54
Abstract: We introduce a generalized definition of parton distribution functions (PDFs) for a more consistent all-order treatment of power corrections. We present a new set of modified DGLAP evolution equations for nuclear PDFs, and show that the resummed $\alpha_s A^{1/3}/Q^2$-type of leading nuclear size enhanced power corrections significantly slow down the growth of gluon density at small-$x$. We discuss the relation between the calculated power corrections and the saturation phenomena.
Jing Shen,Zhanqian Song,Xueren Qian,Wenxia Liu
BioResources , 2009,
Abstract: In order to improve the acid-resistant property of papermaking grade precipitated calcium carbonate filler and to obtain modified filler in powder form, sodium silicate/zinc chloride based modifiers were used in filler modification, and the use of modified filler in papermaking of deinked pulp derived from recycled newspaper was also preliminarily investigated. Under the preliminarily optimized experimental conditions, when sodium silicate, zinc chloride, sodium hexametaphosphate, and phosphoric acid with dosages of 10 wt%, 3 wt%, 1 wt% and 0.2 wt%, respectively, were used as modifiers, and when the temperature, aging time, and PCC concentration during the filler modification process was 70 oC, 7 h and 9.1 wt%, respectively, the acid-resistant property of filler was significantly improved after modification, as evaluated using alum consumption and pH methods. The use of modified precipitated calcium carbonate filler prepared under the optimized conditions provided considerably more brightness and light scattering improvement in comparison to unmodified filler, and filler modification was found to have only negligible influence on tensile and burst strength of the paper, air permeability of the paper, and retention performance of the filler. Surface analysis of the modified filler using XPS and SEM confirmed the occurring of surface encapsulation and modification of precipitated calcium carbonate filler when the relevant modifiers were used in filler modification. The encapsulating effect of modifiers on filler was thought to be favorable to improvement in acid-resistant property, and optical properties of the filled paper.
Nuclear modification factor in p+pb collisions at LHC and saturation  [PDF]
Amir H. Rezaeian
Physics , 2009,
Abstract: We provide predictions for the nuclear modification factor R_{pA} for pions and direct photon production in p+A collisions at LHC energy at midrapidity within different saturation models fitted to HERA data. In our approach we have no free parameters to adjust and all model parameters are fitted to other reactions. Our approach gives a rather good description of PHENIX data for R_{pA} for pions. We show that, in various saturation models, the pion Cronin enhancement is replaced by a moderate suppression at LHC energy at midrapidity due to gluon shadowing effects. However, Cronin enhancement of direct photons can survive at LHC energy in models with a larger saturation scale. We show that both shadowing and saturation effects are important at LHC in p+A collisions and give rise to a rather sizable effect in the nuclear modification factor R_{pA}. Therefore, a precise measurement of p+A collisions at LHC is crucial in order to understand the underlying dynamics of heavy ion collisions.
Saturation and hysteresis effects in ionospheric modification experiments observed by the CUTLASS and EISCAT radars
D. M. Wright, J. A. Davies, T. K. Yeoman, T. R. Robinson,H. Shergill
Annales Geophysicae (ANGEO) , 2006,
Abstract: The results of high latitude ionospheric modification experiments utilising the EISCAT heating facility at Troms are presented. As a result of the interaction between the high power pump waves and upper hybrid waves in the ionosphere, field-aligned electron density irregularities are artificially excited. Observations of these structures with the CUTLASS coherent HF radars and the EISCAT incoherent UHF radar exhibit hysteresis effects as the heater output power is varied. These are explained in terms of the two-stage mechanism which leads to the growth of the irregularities. Experiments which involve preconditioning of the ionosphere also indicate that hysteresis could be exploited to maximise the intensity of the field-aligned irregularities, especially where the available heater power is limited. In addition, the saturation of the irregularity amplitude is considered. Although, the rate of irregularity growth becomes less rapid at high heater powers it does not seem to fully saturate, indicating that the amplification would continue beyond the capabilities of the Troms heater - currently the most powerful of its kind. It is shown that the CUTLASS radars are sensitive to irregularities produced by very low heater powers (effective radiated powers <4 MW). This fact is discussed from the perspective of a new heating facility, SPEAR, located on Spitzbergen and capable of transmitting high frequency radio waves with an effective radiated power ~10% of that of the Troms heater (28MW). Full Article (PDF, 907 KB) Citation: Wright, D. M., Davies, J. A., Yeoman, T. K., Robinson, T. R., and Shergill, H.: Saturation and hysteresis effects in ionospheric modification experiments observed by the CUTLASS and EISCAT radars, Ann. Geophys., 24, 543-553, doi:10.5194/angeo-24-543-2006, 2006. Bibtex EndNote Reference Manager XML
Development of Fabrication Methods of Filler/Polymer Nanocomposites: With Focus on Simple Melt-Compounding-Based Approach without Surface Modification of Nanofillers  [PDF]
Mitsuru Tanahashi
Materials , 2010, DOI: 10.3390/ma3031593
Abstract: Many attempts have been made to fabricate various types of inorganic nanoparticle-filled polymers (filler/polymer nanocomposites) by a mechanical or chemical approach. However, these approaches require modification of the nanofiller surfaces and/or complicated polymerization reactions, making them unsuitable for industrial-scale production of the nanocomposites. The author and coworkers have proposed a simple melt-compounding method for the fabrication of silica/polymer nanocomposites, wherein silica nanoparticles without surface modification were dispersed through the breakdown of loose agglomerates of colloidal nano-silica spheres in a kneaded polymer melt. This review aims to discuss experimental techniques of the proposed method and its advantages over other developed methods.
X-ray Emission From Nearby M-dwarfs: the Super-saturation Phenomenon  [PDF]
David J James,Moira M Jardine,Robin D Jeffries,Sofia Randich,Andrew Collier Cameron,Miguel Ferreira
Physics , 2000, DOI: 10.1046/j.1365-8711.2000.03838.x
Abstract: A rotation rate and X-ray luminosity analysis is presented for rapidly rotating single and binary M-dwarf systems. X-ray luminosities for the majority of both single & binary M-dwarf systems with periods below $\simeq 5-6$ days (equatorial velocities, V$_{eq}>$ 6 km~s$^{-1}$) are consistent with the current rotation-activity paradigm, and appear to saturate at about $10^{-3}$ of the stellar bolometric luminosity. The single M-dwarf data show tentative evidence for the super-saturation phenomenon observed in some ultra-fast rotating ($>$ 100 km~s$^{-1}$) G & K-dwarfs in the IC 2391, IC 2602 and Alpha Persei clusters. The IC 2391 M star VXR60b is the least X-ray active and most rapidly rotating of the short period (P$_{rot}<$ 2 days) stars considered herein, with a period of 0.212 days and an X-ray activity level about 1.5 sigma below the mean X-ray emission level for most of the single M-dwarf sample. For this star, and possibly one other, we cautiously believe that we have identified the first evidence of super-saturation in M-dwarfs. If we are wrong, we demonstrate that only M-dwarfs rotating close to their break up velocities are likely to exhibit the super-saturation effect at X-ray wavelengths.
Modification of Ce(SO4)2 on Phosphosilicate Gels used as Proton Conductors
HU Lin-Na,HE Jun-Hua,PENG Hui-Fen,ZHANG Yue-Xing
无机材料学报 , 2009, DOI: 10.3724/sp.j.1077.2009.01197
Abstract: Preparation of proton conductors with good chemical durability and high proton conductivity is prerequisite for increasing efficiency of medium temperature fuel cells. In this research, new type of proton conductors were synthesized by adding Ce(SO4)2 to the phosphosilicate gels through sol-gel process. The results prove that adding Ce(SO4)2 can apparently increase proton conductivity of the gels, which reaches the maximum conductivity with the Ce(SO4)2 content of 0.81%, i.e. |мSUB>100=1.25S/m, |мSUB>130=2.11S/m. These values are 70% higher than those without adding Ce(SO4)2. The proton conductivity of the gels will decrease by 20% in dry argon atmosphere, that is, |мSUB>100=1.06S/m, |мSUB>130=1.68S/m. Thermal analysis reveals that introduction of Ce(SO4)2 results in an increase in water-retention ability of the gels. Furthermore, NMR spectra indicate that there forms more PO43- isolated phosphate structure units containing no bridgea2oxygen (Q0) and Q1 structure units containing one bridgea2oxygen like Si aO aP and P aO aP in the Ce(SO4)2-containing gels. These structure units are favorable to proton transportation, which increase the proton conductivity of the gels.
Filler influence on properties of polymer structures Влияние наполнителя на процесс формирования полимерных структур ВПЛИВ НАПОВНЮВАЧА НА ПРОЦЕС ФОРМУВАННЯ ПОЛ МЕРНИХ СТРУКТУР  [cached]
С.В. ?ванов,В.В. Трачевский,О.С. Т?това,Н.В. Столярова
Proceedings of National Aviation University , 2004,
Abstract: Influence of filler on properties of polymer structures has been studied. Influence of filler surface change on the process of polymer structures formation has been shown. Рассмотрено влияние наполнителя на процесс формирования полимерных структур. Показана возможность целенаправленного влияния наполнителя на процесс формирования полимерных структур изменением поверхности наполнителя. Розглянуто вплив наповнювача на процес формування пол мерних структур. Показано можлив сть ц леспрямованого впливу наповнювача на процес формування пол мерних структур зм ною поверхн наповнювача.
Rodica Zavoianu,Adriana Urda,Anca Cruceanu,E. Angelescu
Analele Universitatii Bucuresti : Chimie , 2003,
Abstract: The physico-chemical and catalytic activities of Zr-, Sn- and Ce- modified HZSM-5zeolite catalysts utilised in n-butene conversion were analysed and correlated with the nature ofthe modifying agent. In modified catalysts prepared by impregnation technique, the modifyingelement is found mainly as an oxide on the external surface of the zeolite. Its presence generatesmodifications of the acidity and of the specific surface area of the zeolite. The highest selectivityfor n-butene aromatisation was obtained with the catalyst modified by Sn, which was the elementwith the lowest ionic radius and the highest electronegativity. The modification with Sngenerates the catalyst with the highest surface area and the highest proportion of strong acidsites.
Effects of Al2O3-Particulate-Contained Composite Filler Materials on the Shear Strength of Alumina Joints
Effects of Al2O3—Particulate—Contained Composite Filler Materials on the Shear Strength of Slumina Joints

Jianguo YANG,Hongyuan FANG,Xin WAN,

材料科学技术学报 , 2002,
Abstract: Al2O3/Al3O3 joints were brazed with a new kind of filler materials, which were formed by adding Al2O3 particulates into Ag-Cu-Ti active filler metal. The results showed that the material parameters (the Ti content, Al2O3 particulate volume fraction) of the composite filler materials affected the shear strength of brazed joints. When the Ti content was 2 wt pct in the filler metal, the shear strength of brazing joints decreased with the increasing the volume ratio of Al2O3 particulate. When the Ti content was 3 wt pct in the filler metal, the shear strength of joints increased from 93.75 MPa(Al2O3p 0 vol. pct) to 135.32 MPa(Al2O3p 15 vol. pct).
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