95 學年度入學碩士班甄試-複試試題 考試時間:2 小時 Test Problems of Entrance Examination for Graduate Study

95 學年度入學碩士班甄試-複試試題
考試時間:2 小時
Test Problems of Entrance Examination for Graduate Study
Department of Materials Science and Engineering
National Tsing-Hua University
Part One: 30% (Selecting the most appropriate choice, for each question, 2%
for correct answer, 0% for no answer, 2/3% deduction from total score of this
part for wrong answer)
Water is essential for sustaining life and warn liquid is thought to be responsible for life
generation. Earth, fortunately, has plenty of it: if plate tectonics stopped forming mountains,
and erosion then flattened our planet, the whole surface would be submerged by 2.8
kilometers of water. There are two obvious sources of terrestrial water. The rocks that formed
Mercury, Venus, Earth, the Moon, Mars, and asteroid belt initially contained considerable
amount of water retained during their formation. If the temperature rose above 800 degree
Celsius, through, for example, radioactive heating, the rocks would have “cracked’ and water
would have been released. More than half of the mass of comets is in the form of ice, so
cometary impacts bring water to planetary surfaces too. Venus and Mars were therefore wet
on the surface in the past. In the case Venus, the high temperatures and ultraviolet radiation
flux have split the water into hydroxyl radicals (OH) and hydrogen (H), and these have slowly
escaped from the clutches of the planetary gravitational field. Mars has also lost a lot of water
and considerable amounts are probably under the surface in the form of a permafrost. In early
1998 the US spacecraft Lunar Prospector was placed in a 100-kilometre-high orbit around the
Moon. An on-board neutron spectrometer detected slow neutrons every time the spacecraft
passed over the lunar north and south poles. There were produced by cosmic rays bouncing
off hydrogen atoms. And the most likely ‘home’ of the hydrogen was thought to be water
molecules. Some of the deep craters near the lunar poles are in perpetual darkness. Their
temperatures are so low that any water released nearby is immediately frozen solid. Lunar
Prospector found somewhere between 11 million and 330 million tones of ice at the poles.
This might be extremely useful if ever the Moon is colonized.
1. This article addresses a scientific fact of (1) life on Mars, (2) water on Moon, (3) bacteria
on ancient rocks, (4) chemical reaction between oxygen and hydrogen
2. H2O was found by (1) X-ray emission, (2) infrared, (3) neutron detection, (4) electron
3. Where is most likely place to find water on Mars, (1) surface, (2) pole regions, (3) ice in
rocks, (4) ice layer beneath surface
4. Where water or ice was found on Moon (1) pole regions, (2) Moon atmosphere, (3) Moon
rocks, (4) Moon equator
5. The most likely answer to no sign of water in Venus is (1) water vaporization, (2) cosmic
ray damage, (3) asteroid impacts, (4) escape of OH and H from Venus
Graphite Found to Exhibit Surprising Quantum Effects
Pencil lead is actually graphite-a carbon mineral that, when dragged across paper,
leaves writing behind because its atomic layers separate easily. This also means that it is an
excellent conductor of electricity. Last year, Andre Geim of the University of Manchester in
the U.K. used adhesive tape to strip graphite down to a layer just one atom thick; they called
this superthin layer of graphite "graphene." Experiments on graphene have revealed some
strange phenomena. The two-dimensional material remains capable of conducting electricity
thanks to the free-floating electron in the honeycomb structure of carbon atoms.
Geim's team found that these electrons do not slow down, even at very low temperatures.
In essence, the electrons act as if they have no mass, or no "rest mass," to use the more precise
phrase from special relativity. It also means that graphite--at least the two-dimensional variety
- never stops conducting. Dubbing these pseudo-relativistic particles "massless Dirac
fermions," the researchers also proved that they travel far faster than electrons in other
semiconductors. As such, they conform to that famous equation E=mc2 (with their actual
speed, some 400 times slower than the speed of light, standing in for c).
Physicists at Columbia University, led by Philip Kim, independently confirmed these
findings and also found that the massless electrons fulfilled the predictions of the Hall effect.
This effect is also applicable at the quantum level, with one caveat: instead of the voltage
smoothly increasing as the magnetic field intensifies, the voltage jumps up in steps. And that
is exactly how the massless electrons in the graphene behaved, according to both groups.
Ultimately, Kim writes, the findings may "lead to new applications in carbon-based
electronic and magneto-electronic devices," though further research is needed. It also means
that the graphite left behind by a pencil--stripped down to a layer one atom thick--can be used
to prove the theories scrawled in pencil by physicists of old.
6. Which of the followings is wrong? (1) graphite is a semiconductor (2) graphite has
conducting electrons (3) graphite can be stripped layer by layer (4) graphite is used in
7. Which of the following statement regarding “graphene” is wrong? (1) a single atomic
layer of graphite (2) graphene has anisotropic electrical conductivity (3) the mass of the
conducting electron in graphene is slightly smaller than that of free electron (4) the
conducting electrons in graphene fulfill Pauli Exclusion Principle
8. Which of the following is right? (1) Electrons in graphene behave like zero spin particles
(2) Free-floating electrons in graphene travel in light speed (3) graphene is an insulator (4)
none of the above
9. When applying a magnetic field through grapheme, the Hall voltage measured (1)
increases smoothly with increasing magnetic field due to quantum effect (2) increases
discontinuously with intensifying magnetic field (3) does not change with varying
magnetic field (4) none of the above
10. Which of the following statement is incorrect? (1) the resistance of graphene may change
with magnetic field (2) Free-floating electrons in graphene fulfill the relationship E=mc2
(3) graphene is a good conductor at low temperature (4) none of the above are true
Scanning Probe Evolution in Biology
Twenty years ago the first scanning probe instrument, the scanning tunneling microscope, opened
up new realms for our perception of the world. Atoms that had been abstract entities are now real
objects, clearly seen as distinguishable individuals at particular positions in space. A whole family of
scanning probe instruments has been developed, extending our sense of touching to the scale of atoms
and molecules. The importance of the development of scanning probe microscopy (SPM) is
comparable to that of electron microscopy and even optical microscopy. SPM measures the near-field
physical interactions between the scanning probe tip and the atoms that lie beneath it as it moves.
Atomic force microscopy (AFM), a member of the SPM family, has become particularly important for
the study of biological systems. AFM produces three-dimensional (3D) images of a surface at atomic
resolution; even subatomic resolution has been reported for atomic orbitals on a silicon surface. Its
major advantage is that it can produce high-resolution topographic images in aqueous and
physiologically relevant environments without the need to stain the specimen; the AFM contrast
mechanism does not depend on atomic number, but simply senses the specimen surface through the
force between it and a sharp probe that scans the surface.
Local probes, the central feature of all scanning probe instruments, are small-sized objects such
as the ends of sharp tips; the interaction of the tip with the surface of a sample can be sensed at
selected positions. Proximity to or contact with the sample is required for high spatial resolution. The
principal idea is quite old and had appeared in literature from time to time, in the context of bringing a
source of electromagnetic radiation in close contact with a sample, but was not pursued until recently.
Nanoscale local probes require atomically stable tips and high-precision manipulation devices. The
latter are based on mechanical deformations of spring-like structures by given forces— piezoelectric,
mechanical, electrostatic, or magnetic— to ensure continuous and reproducible displacements with
precision down to the picometer level. They also require effective acoustic, thermal, and vibration
isolation. The resolution that can be achieved with local probes is primarily a function of the effective
probe size, its distance from the sample, and the distance dependence of the interaction between probe
and sample measured. The last can be considered to create an effective aperture by selecting a small
feature of the overall geometry of the probe tip, which then corresponds to the effective probe.
11. The operation of scanning probe microscopy relies on (1) a scanning biological specimen, (2) a
scanning electron beam, (3) a scanning photon beam, (4) a scanning sharp tip.
12. The advantages of atomic force microscopy do not include (1) no need to stain a specimen, (2)
high resolution down to the atomic level, (3) capability of chemical composition analysis, (4)
ability to image in liquid.
13. Local probe methods require (1) effective acoustic, thermal, and vibration isolation, (2) a source of
electromagnetic radiation, (3) a three-dimensional image of a surface, (4) an aqueous and
physiologically relevant environment.
14. For a local probe method, (1) surface properties can be sensed at different positions, (2) the
principal idea was developed in the last decade, (3) close proximity to the sample is forbidden to
avoid sample damage, (4) a manipulation device with micrometer scale resolution is adequate.
15. Which of the following statement is correct? (1) Atomic force microscopy was developed more
than 20 years ago. (2) Scanning tunneling microscopy is a member of the scanning probe
microscopy family. (3) The resolution of a local probe method is related to the local
electromagnetic field. (4) Individual atoms can not be imaged clearly by scanning probe
Answer sheet for Part One:
Part Two: 30% (Please give a concise answer with English on the following
1. Briefly describe why nanoparticles are more chemically reactive than bulk materials. (15%)
2. Explain briefly the basic principles of a laser and describe the differences between the light
beams from a laser and a tungsten filament light bulb. (15%)
Part Three: 40% (Please answer the following questions with English in
detail, no less than 150 words for each problem)
1. The amount of CO2 in the atmosphere is 0.03 %, and the total volume of CO2 presently in
our atmosphere is 1.5 x 1018 L. The world uses an equivalent of approximately 7 x 1012 kg
of gasoline (assuming that this gasoline is in the form of octane and has a density of 0.79
g/mL) per year to meet its energy need. Determine how long it would take to double the
amount of CO2 in the atmosphere due to the combustion of gasoline. The gasoline is
combusted according to the following balance reaction:
2C8H18 (l) + 25 O2 (g)
16 CO2 (g) + 18 H2O (g)
Some people have criticized the idea that fossil-fuel combustion causes global warming.
They say that carbon dioxide is a very small and natural component of the earth’s
atmosphere and therefore dose not pose a problem. Respond to this faulty argument.(10%)
2. In summer, you may buy a can of cold drink and bring it in hand to the dormitory. On the
way to your dormitory, you have to pass a long path paved with asphalt. It is shinning and
windy outdoors. The drink gets warm when you arrive at the dormitory. Please analyze the
heat transfer of the drink during walking across the path. (15%)
3. Is an electron a particle?
Is it a wave?
Explain. (15%)