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Sreekar Wunnava Christina F. Dirscherl Jakub Výravský Dr. Aleš Kovařík Dr. Roman Matyášek Prof. Jiří Šponer Prof. Dieter Braun Dr. Judit E. Šponer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(70):17581-17585
The assembly of ancient informational polymers from nucleotide precursors is the central challenge of life's origin on our planet. Among the possible solutions, dry polymerization of 3’,5’-cyclic guanosine monophosphate (3’,5’-cGMP) has been proposed as a candidate to create oligonucleotides of 15–20 units in length. However, the reported sensitivity of the reaction to the presence of cations raised questions of whether this chemistry could be relevant in a geological context. The experiments in this study show that the presence of cations is not restrictive as long as the reaction is conducted in an acidic environment, in contrast to previous reports that suggested optimal conditions at pH 9. 相似文献
3.
V. Matyáš 《Czechoslovak Journal of Physics》1972,22(7):553-559
A model of structure periodically modulated in three dimensions is calculated in the presented paper and applied to the alloy Cu80Au20. The existence and intensity of the side-bands of the Bragg lines appearing with hyperstructural lines on films of this alloy after heating to temperature on the border of the order-disorder transformation are explained by means of the given model and the value of the period of sinusoidal variation of the lattice parameter and scattering power is calculated.ikova 22, Brno, Czechoslovakia.The author thanks Mrs. V. Gregor and Mr. M. Jelínek who prepared the necessary pictures. 相似文献
4.
The paper gives the results of measuring the temperature dependence of the electrical conductivity(T), the Hall coefficientR
H
(T) and the magnetic susceptibility(T) forn-type CdSnAs2. The effective mass of the electrons was determined by analysis of the measured dependences on the basis of the simple theory for an isotropic non-degenerate semi-conductor. It was found to bem
n
/m
0=2×10–2 in the intrinsic region and does not depend on the temperature; the energy gap ise
g
0=0·26 eV and the molar susceptibility of the CdSnAs2 lattice
G
mol=–112× ×10–6. The mobility of the electrons in the intrinsic region reaches a value of
n
=25 000 cm2V–1sec–1 at 500°K and decreases exponentially
n
T
–1.67 with rising temperature. The density of CdSnAs2 was determined pyknometrically,g9=5·35 g cm–3. The measurements were made on ann-type polycrystalline sample consisting of crystals a few millimetres in diameter, which at a temperature of 100°K had a free electron concentration ofn
s
=6×1016 cm–3.
The authors would like to thank Mr. P. Jansa for help in measuring the temperature dependence of the magnetic susceptibility. 相似文献
CdSnAs2
(T), R H (T) (T) CdSnAs2 . m n /m 0= =2.10–2, ; E G 0=0,26 eV, CdSnAs2 G mol= =–112.10–6. 500°K n =25 000 cm2V–1sec–1 , n T –1,67. CdSnAs2 =5,35 g cm–3. , , 100°K n s =6.1016cm–3.
The authors would like to thank Mr. P. Jansa for help in measuring the temperature dependence of the magnetic susceptibility. 相似文献
5.
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7.
Miloš Matyáš 《Czechoslovak Journal of Physics》1958,8(3):301-307
The results are given of measuring the temperature dependence of the susceptibility of samples of n- and p-type PbTe, containing either an excess of one or other of the components or ions Cl–, or Ag+, as impurities. The conception of cation or anion vacancies, which can be occupied by a hole or electron, Ag+ or Cl– ions, was employed, in addition to the constants taken from other measurements, to explain the dependences measured. 相似文献
8.
9.
Miloš Matyáš 《Czechoslovak Journal of Physics》1958,8(5):544-546
The effective masses of electrons m
n
/m
o
in the intrinsic region are calculated on the basis of measurements of the temperature dependence of the total magnetic susceptibility and the Hall coefficient of single-crystal and polycrystalline specimens of n- and p-type InSb. It is shown that the effective masses m
n
/m
o
are constant in the range considered and their values for the various specimens are 3·43×10–2 to 3·53×10–2. 相似文献
10.