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991.
Milyukov  V. K.  Yeh  Hsien-Chi 《Astronomy Reports》2018,62(12):1003-1012
Astronomy Reports - A review of the achievements of space geodesy in the 21st century, represented by the successful realization of the CHAMP, GOCE, and GRACE missions, is presented. The main...  相似文献   
992.
There is lack of information regarding ammonia nitrogen (AN), (i.e. NH3-N) decay rate of river water in tropical regions like Malaysia. AN decay rate is a very important kinetic parameter to estimate NH3-N, nitrate nitrogen (NO3-N) and dissolved oxygen concentrations of river water by using computer models. This study presents determination of ammonia nitrogen decay rate of river water in the tropical environment of Malaysia. A laboratory flume was used to conduct twelve experiments. The flume was used to represent the turbulent condition of a typical river. Ammonia nitrogen decay rate for the tropical environment of Malaysia was observed to be between 0.194 and 0.554 per day. Median value of AN decay rate was 0.26 per day, which is slightly lower than the global median value of 0.295 per day. To check the accuracy of flume experiments, the AN decay rate of Pusu River obtained from the flume experiment was used to calibrate and validate ammonia nitrogen concentration of the river by using water quality analysis and simulation program (WASP). Very good calibration and validation results were achieved, which substantiated the accuracy of the flume experiments.  相似文献   
993.
994.
Lithology and Mineral Resources - Nummulite facies are known to be a good indicator of Eocene shallow-water paleoenvironments. Nummulitic limestones are widespread in the Lower Eocene of...  相似文献   
995.
Lithology and Mineral Resources - Upper Paleozoic sections in Taimyr comprise genetic rock complexes of different zones: deep-water shelf; offshore transition zone; shoals, deltas, and beaches of...  相似文献   
996.
Doklady Earth Sciences - This paper discusses sources of significant errors that occur in the course of determination of the primary environmental standard for natural waters: the maximum...  相似文献   
997.
Doklady Earth Sciences - The first results of studies of vertical particle fluxes in a hydrothermal sedimentary system of a subpolar area of the Mid-Atlantic Ridge under the influence of...  相似文献   
998.
Mathematical Geosciences - Manually interpreting multivariate drill hole data is very time-consuming, and different geologists will produce different results due to the subjective nature of...  相似文献   
999.
Tension-Only Concentrically Braced Frames (TOCBF) exhibit deteriorating pinched hysteretic behaviour during strong earthquakes. Slender braces transit between an elastic buckling state, a restraightening state, in which they carry almost no load, an elastic tensile loading state as they are suddenly taut and, finally, a tensile yielding state. It has long been suspected that the sudden increase in tensile forces in the braces of TOCBSF creates detrimental impact loading on the connections and other structural elements. No experimental evidence, however, has been provided so far to confirm, or to quantify, this impact phenomenon. This paper addresses this issue through shake table tests of half scale, two-storey, TOCBF models. By normalizing the hysteresis loops of braces obtained from shake table tests to the yield strength of steel obtained from quasi-static tests, the increase in tensile forces in the braces was obtained. Results of dynamic tensile tests on steel coupons under similar strain rates as observed during the shake table tests showed that this increase in tensile forces is not the result of impact, but is rather caused by a yield strength increase of the steel under high strain rate. A procedure is proposed to estimate and account for this increase in tensile forces in the braces at the design stage.  相似文献   
1000.
Solar System Research - Ionizing radiation is one of the main factors that destroy biomolecules in extraterrestrial conditions. The effects of radiation depend on the conditions of the exposure...  相似文献   
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