The size effect rule of roller compacted concrete (RCC) fracture toughness was reached on the analysis of fracture toughness of RCC specimens, which have been done by project team. And then the rule was applied to the...The size effect rule of roller compacted concrete (RCC) fracture toughness was reached on the analysis of fracture toughness of RCC specimens, which have been done by project team. And then the rule was applied to the calculation formula of equivalent strength of crack director in the RCC arch dam, thus a simple and useful formula was reached. The study shows that the equivalent strength of crack directors increases with the increasing intensity of concrete, but the surplus rate of strength of crack directors section decreases with the increasing intensity of concrete and the distance between centers of adjacent crack directors, and that bilateral interval crack directors are more efficient in weakening the strength of section than unidirectional interval crack directors in the case of the same distance between adjacent crack director centers. A good design for crack directors of RCC arch dam is proposed via the rule.展开更多
The optimum models for cultivationg the seedlings of Dahurian Larch (Larix gmelim Rupr. ) were studied in the central nursery of Tahe Forestery Bureau from 1989 to 1993. The resultswerc as follows The optimum...The optimum models for cultivationg the seedlings of Dahurian Larch (Larix gmelim Rupr. ) were studied in the central nursery of Tahe Forestery Bureau from 1989 to 1993. The resultswerc as follows The optimum models of the main morphological standards of the seedlings were30000 kg /hm2 of' decomposed' ash for improviong soil, 70,000 kg/hm2 of excrement and 1,500 kg/hm2of' calcium superphosphate as basal fertilizer , and 500 kg/hm2 of (NH4)2HPO4 and 220 kg/hm2 of'urea as top dressing. During growth perlod of the seedlings, the growth was greatly checked when thesoil water suction (SWS) was uithin 50 ~ 73. 3 kPa or below 10 kPa but greatest when SWS waswithin 30 ~ 40 kPa in initial growth stage and within 10-20kPa in last growth stage. The method for determining the optimum sowing time is to measure the depth of soil thawing, accumulated temperature abovc 5℃ both at 5 cm of the depth of of soil and in atmosphere. In Tahe region, the optimumsowing trme for Dahurian larch for Dahuria larch is about on May 10 when the depth of soil thawing, the accumulatedtemperature above 5℃ at 5 cm of the depth and the accumulated temperature above 5℃ in atmosphere reaches 40 cm. abovc 46℃ and abovae 56℃ respectively. The optimum seedlings density forthis region is 600-800 individuals/m2.展开更多
Promulgated last year, the latest set of Chinese regulations on merger and acquisition (M&A) are now starting to be applied, and we revisit these regulations below:
基金Sponsored by the National Natural Science Foundation of China(Grant No.50179002,50709013)Liaoning Province Dr. Fund(Grant No.20071025)
文摘The size effect rule of roller compacted concrete (RCC) fracture toughness was reached on the analysis of fracture toughness of RCC specimens, which have been done by project team. And then the rule was applied to the calculation formula of equivalent strength of crack director in the RCC arch dam, thus a simple and useful formula was reached. The study shows that the equivalent strength of crack directors increases with the increasing intensity of concrete, but the surplus rate of strength of crack directors section decreases with the increasing intensity of concrete and the distance between centers of adjacent crack directors, and that bilateral interval crack directors are more efficient in weakening the strength of section than unidirectional interval crack directors in the case of the same distance between adjacent crack director centers. A good design for crack directors of RCC arch dam is proposed via the rule.
文摘The optimum models for cultivationg the seedlings of Dahurian Larch (Larix gmelim Rupr. ) were studied in the central nursery of Tahe Forestery Bureau from 1989 to 1993. The resultswerc as follows The optimum models of the main morphological standards of the seedlings were30000 kg /hm2 of' decomposed' ash for improviong soil, 70,000 kg/hm2 of excrement and 1,500 kg/hm2of' calcium superphosphate as basal fertilizer , and 500 kg/hm2 of (NH4)2HPO4 and 220 kg/hm2 of'urea as top dressing. During growth perlod of the seedlings, the growth was greatly checked when thesoil water suction (SWS) was uithin 50 ~ 73. 3 kPa or below 10 kPa but greatest when SWS waswithin 30 ~ 40 kPa in initial growth stage and within 10-20kPa in last growth stage. The method for determining the optimum sowing time is to measure the depth of soil thawing, accumulated temperature abovc 5℃ both at 5 cm of the depth of of soil and in atmosphere. In Tahe region, the optimumsowing trme for Dahurian larch for Dahuria larch is about on May 10 when the depth of soil thawing, the accumulatedtemperature above 5℃ at 5 cm of the depth and the accumulated temperature above 5℃ in atmosphere reaches 40 cm. abovc 46℃ and abovae 56℃ respectively. The optimum seedlings density forthis region is 600-800 individuals/m2.
文摘Promulgated last year, the latest set of Chinese regulations on merger and acquisition (M&A) are now starting to be applied, and we revisit these regulations below:
