[多选题]国家鼓励开发网络数据安全保护和利用技术，促进公共数据资源开放-我要搜题网

[单选题]旅客须按票面载明的日期、车次、席别乘车，并在（）有效期内到达到站。
A.票面规定
B.指定的
C.规定的
D.约定的

[单项选择]心脏病孕妇容易发生心力衰竭的时期是（）
A. 妊娠32～34周
B. 妊娠24~26周
C. 妊娠28~30周
D. 妊娠20~22周
E. 妊娠36～37周

[多选题]接触焊的常见缺陷有( )。
A.灰斑
B.裂纹
C.烧伤
D.未焊合

[不定项选择题]共用题干 Solar Power Without Solar Cells

A dramatic and surprising magnetic effect of light discovered by University of Michigan researchers
could lead to solar power without traditional semiconductor-based solar cells.
The researchers found a way to make an"optical________(51)",said Stephen Rand,a professor in
the departments of Electrical Engineering and Computer Science,Physics and Applied Physics.
Light has electric and magnetic_______(52).Until now,scientists thought the effects of the mag-
netic field were so weak that they could be________(53).What Rand and his colleagues found is that at
the right intensity,when light is traveling through a material that does not_________(54)electricity,the
light field can generate magnetic effects that are 100 million times stronger than previously expected.Under
these circumstances,the magnetic effects develop strength_________(55)to a strong electric effect.
"This could lead to a new kind of solar cell without semiconductors and without absorption to produce
charge separation,"Rand said."In solar cells,the_________(56)goes into a matenal,gets absorbed and
creates heat.Here,we expect to have a very low heat load.Instead of the light being absorbed,energy is
stored in the magnetic moment.Intense magnetization can be induced by intense light and then it is ultimately
capable of providing a capacitive power________(57)."What makes this possible is a previously unde-
tected brand of"optical rectification",says William Fisher,a doctoral student in applied physics.In tradi-
tional optical rectification,light's electric field causes a charge separation,or a pulling_________(58)of
the positive and negative charges in a material.This sets up a voltage,similar to______(59)in a
battery.
Rand and Fisher found that under the right circumstances and in right types of materials,the light's
magnetic field can also create optical rectification.The light must be shone through a________(60)that
does not conduct electricity,such as glass.And it must be focused to an intensity of 10 million watts per
square centimeter. Sunlight isn't this_______(61)on its own,but new materials are being sought that
would work at lower intensities,Fisher said.
"In our most recent paper,we show that incoherent light like sunlight is theoretically almost
_________(62)effective in producing charge separation as laser light is,"Fisher said.
This new_________(63)could make solar power cheaper,the researchers say.They predict that with
improved materials they could achieve 10 percent efficiency in converting solar power to usable energy.That's
equivalent to today's commercial-grade solar cells.
"To manufacture modern solar cells,you have to do. _______(64)semiconductor processing,"
Fisher said."All we would need are lenses to focus the light and a fiber to guide it.Glassworks for
_________ (65).It's already made in bulk,and it doesn't require as much processing.Transparent
ceramics might be even better." _________(61)
A.bright
B.faint
C.visible
D.intense

[多选题]国家鼓励开发网络数据安全保护和利用技术，促进公共数据资源开放，推动()。A.技术创新 B.网络革命 C.经济社会发展 D.改革开放

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[多选题]国家鼓励开发网络数据安全保护和利用技术，促进公共数据资源开放，推动()。
A.技术创新
B.网络革命
C.经济社会发展
D.改革开放