The crystal structures of Pt(NH3)2CPrDCA.H2O (I), Pt(CH3NH2)2CPrDCA (II), and Pt(dmbn) CPrDCA.2.5H2O (III) (where CPrDCA is 1,1-cyclopropanedicarboxylate; dmbn is 2,3-dimethyl-2,3-butyldiamine) are ...determined. Compound I crystallizes in the orthorhombic space group Pnma with the cell dimensions: a = 6.517(2), b = 9.709(3), c = 14.205(5) A, Z = 4, R = 0.058. Compound II is monoclinic with space group P2(1)/n, a = 9.648(3), b = 8.720(2), c = 12.770(4) A, beta = 107.12(2), Z = 4, R = 0.059. Compound III belongs to the monoclinic system space group P2(1)/m with the cell dimensions: a = 6.494(1), b = 19.638(3), c = 6.606(1)A, beta = 94.44(1), Z = 2, R = 0.038. Electronic structures of the complexes are studied and the correlation between structure of the amine ligands and biological activity of the complexes is explored.
Chromatin prepared both from the yolk granules beneath the blastoderm and from the nuclei of the blastoderm cells of fertilized and unincubated chicken eggs was examined under electron microscope and ...its structure was compared. The results indicate that the above two kinds of chromatin fibers seem to have no apparent difference in structural relation and diameter. The electron microscopic appearances of the basic structures of both kinds of chromatin are all "beads-on-a-string"-shaped filaments. After the digestion of chromatin from both raw materials with DNase I, the connecting strings of chromatin fibers were cut off, only the scattered beads could be observed under electron microscope. The diameter of the scattered beads is equal to that of the beads on the chromatin fibers, and most of them are 150 A in diameter.
The new developed area stability control system in the eastern part of Heilongjiang Power System has been introduced in this paper. The control system was designed to improve the power transmission ...capacity from the eastern part of the Heilongjiang Power System to the western part by generation shedding in case of severe faults. It consists of five control stations, two of them installed in power plants and the others in transformer substations. The GPS-based accurate time signal has been introduced in every station and the voltage phasors are measured based on it. Digital microwave channels are utilized to transmit phasor data, control commands and other information among control stations. The control response time is about 100 ms. As a result, the control system can increase the transmission limits by about 45%. The paper has also introduced some new techniques used in the control system, such as an integrated fault identification approach and the integral of the unbalanced power of generators as a stability control criterion.
The DNA molecules isolated from the blastoderm nuclei and yolk granules beneath the blastoderm of fertilized and unincubated chicken eggs were observed under electron microscope, using the DNA sample ...of calf thymus as control. The results showed that both nuclear and yolk DNAs are linear, and their molecules are very similar to those of thymus DNA in shape. Since chromatin was first prepared from blastoderm nuclei and yolk granules respectively and then DNA was isolated from both of chromatin samples, it could be concluded that yolk granules possess both DNA chromatin as nuclei do.
Electron microscopic study shows that the chromatin structure of yolk granules beneath the "blastoderm region" of the unfertilized chicken egg is identical to that of yolk granules beneath the ...blastoderm of the fertilized and unincubated chicken egg, and both chromatin structures are very similar to those of blastoderm nuclei. Furthermore the molecular shapes of DNA of both yolk granules are also very similar to those of the blastoderm nuclei, being all linear. Based on these observations, we have come to the conclusion that chromatin and DNA widely exist in the yolk when yolk granules have reached their development-specified competence. The results indicate further that the yolk granules are capable of synthesizing DNA, and provide the condition for the interaction of DNA with histones to form chromatin through self-organization.
Two novel ent-kaurane diterpenoids, lungshengenin D(1) and F(2), were isolated from Isodon lungshengensis. Their structures were elucidated on the basis of spectral evidence as ...1α-hydroxy-3β-acetoxy-11β,16β-epoxy-ent-kauran-6-one and 1α-hydroxy-2β,3β,11β-triacetoxy-ent-kaur-16-ene-15-one, respectively.
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