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【简答题】
波长0.097nm的X射线射向某种晶体，观察到该射线在与光滑表面成
的掠射角时出现第3级反射极大，则该晶体这一方向上的晶格常数d为_______nm.（小数点后保留三位）
参考答案：
参考解析：
刷刷题刷刷变学霸
举一反三
【单选题】In the wake of 11 September, Visionics, a leading manufacturer, issued a fact sheet explaining how its technology could enhance airport security. They called it "protecting civilization from the faces...
A.
any way, the face-recognition technology is good enough to frighten the terrorists
B.
the industry will have to recognize the real situation and work hard to improve the technology
C.
all the claims are premature
D.
we must not expect too much
【单选题】Passage 4 In the wake of 11 September, Visionics, a leading manufacturer, issued a fact sheet explaining how its technology could enhance airport security. They called it "protecting civ...
A.
Too many false alarms were raised.
B.
Everyone should look straight at the camera.
C.
Only 90% of suspects at an airport were found.
D.
Everyone should not disguise himself.
【单选题】用X射线照射食盐晶体的表面，发现反射加强时，测得射线与晶面所成的最小掠射角为17.5°，已知食盐的晶格常数为2.814×10-8cm，则x射线的波长为 nm。
A.
1.7×10-8
B.
1.7×10-4
C.
1.7
D.
0.17