Fine Structure of Heliumlike Ions and Determination of the Fine Structure Constant

the underlying structure of language proficiency and the proficiency level

هدف از انجام این تخقیق بررسی رابطه احتمالی بین سطح مهارت زبان خارجی (foreign language proficiency) و ساختار مهارت زبان خارجی بود. تعداد 314 زبان آموز مونث و مذکر که عمدتا دانشجویان رشته های زبان انگلیسی در سطوح کارشناسی و کارشناسی ارشد بودند در این تحقیق شرکت کردند. از لحاظ سطح مهارت زبان خارجی شرکت کنندگان بسیار با هم متفاوت بودند، (75 نفر سطح پیشرفته، 113 نفر سطح متوسط، 126 سطح مقدماتی). کلا ...

g Factor of Light Ions for an Improved Determination of the Fine-Structure Constant.

A weighted difference of the g factors of the H- and Li-like ions of the same element is theoretically studied and optimized in order to maximize the cancellation of nuclear effects between the two charge states. We show that this weighted difference and its combination for two different elements can be used to extract a value for the fine-structure constant from near-future bound-electron g fa...

The Meaning of the Fine Structure Constant

Time Evolution of the Fine Structure Constant

We present a short review of the current quasar (QSO) absorption line constraints on possible variation of the fine structure constant, α ≡ e 2 /¯ hc. Particular attention is paid to recent optical Keck/HIRES spectra of 49 absorption systems which indicate a smaller α in the past [1, 2]. Here we present new preliminary results from 128 absorption systems: ∆α/α = (−0.57 ± 0.10) × 10 −5 over the ...

Uniqueness of the Fine-structure Constant.