39 research outputs found
On the S-wave piD-scattering length in the relativistic field theory model of the deuteron
The S-wave scattering length of the strong pion-deuteron (pi D) scattering is
calculated in the relativistic field theory model of the deuteron suggested in
[1,2].The theoretical result agrees well with the experimental data. The
important role of the Delta-resonance contribution to the elastic pi
D-scattering is confirmed.Comment: 7 pages, no figures, accepted for publication in Z. Phys.
The deuteron: structure and form factors
A brief review of the history of the discovery of the deuteron in provided.
The current status of both experiment and theory for the elastic electron
scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic
The role of the pion cloud in the interpretation of the valence light-cone wavefunction of the nucleon
The pion cloud renormalises the light-cone wavefunction of the nucleon which
is measured in hard, exclusive photon-nucleon reactions. We discuss the leading
twist contributions to high-energy exclusive reactions taking into account both
the pion cloud and perturbative QCD physics. The nucleon's electromagnetic
form-factor at high is proportional to the bare nucleon probability
and the cross-sections for hard (real at large angle or deeply virtual) Compton
scattering are proportional to . Our present knowledge of the pion-nucleon
system is consistent with . If we apply just perturbative QCD
to extract a light-cone wavefunction directly from these hard exclusive
cross-sections, then the light-cone wavefunction that we extract measures the
three valence quarks partially screened by the pion cloud of the nucleon. We
discuss how this pion cloud renormalisation effect might be understood at the
quark level in terms of the (in-)stability of the perturbative Dirac vacuum in
low energy QCD.Comment: Expanded Discussion of Phenomenology and Spin Physic
Analysis and Suggestions for Business Model of eBayEachnet
EBAY易趣网和淘宝网是目前中国电子商务中经常被提及的两个对手。2002年时,EBAY易趣曾经一枝独秀,但在淘宝网和拍拍网的竞争下,迅速丧失市场领先地位,市场份额逐步缩小,并终于与TOM集团有限公司下属的TOM在线成立了合营公司。 本文主要运用翁君奕教授的《商业模式创新》理论,以合营公司的成立为研究截止时间,尝试揭示、分析、解释EBAY易趣商务模式针对中国大陆市场而言存在的不足之处,并提出实现转机的若干建议。全文共分五章,分别如下: 第一章主要介绍论文写作的背景和研究意义所在,以及研究理论和框架。 第二章针对EBAY易趣商务模式,按照商业模式创新理论的层次,从商务模式环境、商务模式要素、...eBayEachnet and Taobao are main competitors in China’s E-commerce. eBayEachnet just took the lead in as earlier as year 2002, however, it was overwhelmed by Taobao and Paipai gradually, the leading was lost and the share market diminished very soon, as a result, it incorporated with Tom Online, a filial of Tom group limited company.Bearing in mind the theory of <Business Models Innovatio...学位:工商管理硕士院系专业:管理学院工商管理教育中心(MBA中心)_工商管理硕士(MBA)学号:20041523
Association of Birth Weight With Type 2 Diabetes and Glycemic Traits: A Mendelian Randomization Study
IMPORTANCE Observational studies have shown associations of birth weight with type 2 diabetes (T2D) and glycemic traits, but it remains unclear whether these associations represent causal associations.OBJECTIVE To test the association of birth weight with T2D and glycemic traits using a mendelian randomization analysis.DESIGN, SETTING, AND PARTICIPANTS This mendelian randomization study used a genetic risk score for birth weight that was constructed with 7 genome-wide significant single-nucleotide polymorphisms. The associations of this score with birth weight and T2D were tested in a mendelian randomization analysis using study-level data. The association of birth weight with T2D was tested using both study-level data (7 single-nucleotide polymorphisms were used as an instrumental variable) and summary-level data from the consortia (43 single-nucleotide polymorphismswere used as an instrumental variable). Data from 180 056 participants from 49 studies were included.MAIN OUTCOMES AND MEASURES Type 2 diabetes and glycemic traits.RESULTS This mendelian randomization analysis included 49 studies with 41 155 patients with T2D and 80 008 control participants from study-level data and 34 840 patients with T2D and 114 981 control participants from summary-level data. Study-level data showed that a 1-SD decrease in birth weight due to the genetic risk score was associated with higher risk of T2D among all participants (odds ratio [OR], 2.10; 95% CI, 1.69-2.61; P=4.03 x 10-5), among European participants (OR, 1.96; 95% CI, 1.42-2.71; P=.04), and among East Asian participants (OR, 1.39; 95% CI, 1.18-1.62; P=.04). Similar results were observed from summary-level analyses. In addition, each 1-SD lower birth weight was associated with 0.189 SD higher fasting glucose concentration (beta=0.189; SE=0.060; P=.002), but not with fasting insulin, 2-hour glucose, or hemoglobin A1c concentration.CONCLUSIONS AND RELEVANCE In this study, a genetic predisposition to lower birth weight was associated with increased risk of T2D and higher fasting glucose concentration, suggesting genetic effects on retarded fetal growth and increased diabetes risk that either are independent of each other or operate through alterations of integrated biological mechanisms
Systematic corrections in the extraction of the pi NN coupling from (p)over-bar-p->(n)over-bar-n differential cross sections
We show that the pi NN coupling constant determined model-independently from Tip charge exchange is subject to a systematic shift, and, more significantly that the strong absorption in the critical region prevents a determination of the coupling constant</p
