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251.
Under 2 100 bar of hydrostatic pressure, KNA N-glycosidase can still cleave the N-C bond of adenosine at position 4324 in R/S domain of 28S RNA in rat ribosome, demonstrating that high pressure has no effect on the tertiary structure of S/R domain.  相似文献   
252.
The evolution of methane carbon isotope with depth has been discussed based on diagenetic reaction kinetics and isotopic Rayleigh fractionational theory. A mathematical model to describe data of methane carbon isotope for the Liaohe oil field has been established.  相似文献   
253.
Discovery and character of the Kunlun-Yellow River Movement   总被引:2,自引:0,他引:2  
Based on geomorphological, tectonic and sedimentary data, a Kunlun Yellow River Tectonic Movement has been recognized in 1 10-0 60 Ma B.P. This tectonic movement, which leads to uplift of the Qinghai_Xizang (Tibet) Plateau from 1 500 to 3 000-3 500 m, is periodic, abrupt and changeable in the movement rate of uplifting and slide slipping.  相似文献   
254.
An oxygen isotope temperature record from 381 to 166 kaB. P. (230Th/234U dating and tuned ages) has been obtained by combining data on the isotopic composition of calcites with that of fluid inclusions trapped in a stalagmite from a limestone cave in which a fossil cranium deposited. Several laminae in microsequence of the stalagmite represent climatic events or shifts. The Nanjing man fossil was older than 381 kaB. P.  相似文献   
255.
256.
The Matuyama/Brunhes polarity boundary (MBPB) is recorded in Chinese loess L8, which is associated with the glacial period. It is proved that loess L8 is capable of recording earth’s secular variation, and the lock-in depth in Chinese loess is no more than that of marine sediments. Comparison with the location of MBPB in Chinese loess and marine sediments, it is put forward that there is a recording phase lag between ocean and continent climate changes.  相似文献   
257.
The development of stamen is an important stage during the sexual reproduction in higher plants. Studying the genes that predominantly or even specifically expressed in stamens will aid in undestanding the molecular mechanism of stamen development. The structure of a rice CHS-like gene (D5) which predominantly expressed in anthers has been analysised, showing high structural similarity with two other anther-specific genes (A1 and BA42) fromBrassica napus. Northern analysis also reveals that the three genes share a similar expression pattern and that the expression of D5 may relate to the early development of pollens. It is concluded that D5, A1 and BA42 represent a group of diverged CHS-like genes which are related to stamen development.  相似文献   
258.
The smectite to illite transformation in active geothermal systems of New Zealand can be simulated by a first-order reaction kinetic model, which provides direct estimates about the minumum ages of active geothermal systems themselves. The derived kinetic values show that the smectite to illite transformation is sensitive to both temperature and time.  相似文献   
259.
The problems about the almost periodic solution to singular systems are studied. The criterion that the singular systems have almost periodic solutions is obtained. At the same time, the applied example is given.  相似文献   
260.
Study of forming mechanism of "chimney-effect" (CE) has important significance for basic theory and applications of non-seismic geophysical and geochemical methods locating oil/gas reservoirs. The theoretical basis of comprehensive evaluation of mechanism of CE using principles of magnetism, geochemistry and mineralogy has been reviewed, with the problems to be solved: (ⅰ) study for the relationship between process of oil/gas migration and geochemical field; (ⅱ) analysis of genesis of magnetic, geochemical and mineralogical anomaly; (ⅲ) interpretation of surface soil magnetism and geochemical anomaly combined with seismic data.  相似文献   
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