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Date: 13-1-2020
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Date: 6-5-2020
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Date: 28-4-2020
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Below we reproduce the FCC structure that was shown above.
You will notice that the B-layer atoms form a hexagon, but this is a cubic structure. How can this be? The answer is that the FCC stack is inclined with respect to the faces of the cube, and is in fact coincident with one of the three-fold axes that passes through opposite corners. It requires a bit of study to see the relationship, and we have provided two views to help you. The one on the left shows the cube in the normal isometric projection; the one on the right looks down upon the top of the cube at a slightly inclined angle.
Both the CCP and HCP structures fill 74 percent of the available space when the atoms have the same size. You should see that the two shaded planes cutting along diagonals within the interior of the cube contain atoms of different colors, meaning that they belong to different layers of the CCP stack. Each plane contains three atoms from the B layer and three from the C layer, thus reducing the symmetry to C3, which a cubic lattice must have.
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الصحة العالمية: شركات التبغ تستهدف جيلا جديدا بهذه الحيل
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بكل عزيمة ونشاط.. كيف يمكن للطلبة مواجهة الامتحانات؟
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قسم شؤون المعارف يعلن عن قرب إطلاق ثلاثة مؤلفات تراثية
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شعبة مدارس الكفيل النسوية تقيم فعاليات مخيم (بنات العقيدة) الواحد والعشرين
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قسم الشؤون الفكرية ومكتبة العتبة العلوية يبحثان سبل تطوير أنظمة المكتبات
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بالصور: وعد فأوفى.. بعد ان افتتحه ممثل المرجعية العليا مستشفى الثقلين لعلاج الاورام في البصرة يستقبل ويعالج مراجعيه مجانا
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