Abstract:In order to recycle iron tailings and fibers and analyze the performance of pavement cement concrete mixed with it, tests and numerical simulations are carried out. The compressive strength of concrete is significantly influenced by the content of Anshan iron tailings, and the highest 28-day compressive strength is 49.60 MPa with 25% iron tailings in sand. The flexural strength of concrete with iron tailings meets the specifications for pavement with 25-30% iron tailings in sand. Iron tailings with a particle diameter in the range of 0.15-0.3 mm are more advantageous. In general, basalt fiber play a greater role than polypropylene fiber in the flexural strength of concrete in this paper.Numerical simulations accurately reflect the performance trends of the tests.
This text was mainly studied the extraction flavonoids technology from Momordia cochinchinensis seeds. The optimum extraction condition was as follows: when the ratio of liquid to solid was 20:1, the ethanol concentration was 90% and the extraction time was 2h. Under this condition, the actual average yield of flavonoids could reach 0.363%.
Textured soybean protein (TSP) is a product made from cooking and extrusion of soybean protein, which has been widely used in food, feed and other industries. This text made soybean protein isolated (SPI) and soybean protein concentrate (SPC) as the raw materials to produce filamentous protein production. By experiment, the influence of puffing temperature, screw speed and feed rate on the quality of the protein products was studied. Finally it was concluded that when the temperature of the barrel was 152 °C, the screw rotation speed was 119 rpm, the feed rate was 0.426 kg/min, the TSP product had the biggest expansion degree.
In order to study the road performance of asphalt mixture with different kinds of iron waste ore , stripping waste rock rich in iron trioxide and stripping waste rock rich in iron oxide are used as aggregate to make the mixture.Through the test comparison, it is confirmed that the dynamic stability performance of asphalt concrete mixture mixed with iron trioxide mining and stripping waste rock is the best, namely its high temperature stability is best; followed by the one mixed with waste rock rich in iron trioxide. The residue stability of asphalt concrete mixed with mining and stripping waste rock increases obviously. It can found from the experiments that the residual stability can be up to 94.96% which kinds of asphalt mixture with waste rock rich in iron trioxide. Asphalt mixture mixed with stripping waste rock has a better anti-sliding performance than the common one, among which the one mixed with aggregates rich in iron trioxide is the best. Through tectonic depth, it is reflected that it also has a better performance on drainage noise reduction. In conclusion, using mining and stripping waste rock instead of mining gravel has a good economic efficiency,but also solved the problem of mining and stripping waste rock accumulation.
This text was mainly studied the response surface optimization of ultrasonic assisted extraction of flavonoids from Brucea javanica. The optimum extraction process conditions were obtained by color reaction to prove the presence of flavonoids and by response surface simulation and quantification, the optimum condition was: ethanol concentration was 90%, the ratio of liquid to solid was 10:1, and the extraction time was 2h, the total extraction rate was the largest, up to about 1.43%.
In this paper, the influence of the combination of last sense codon and stop codon on expression efficiency was studied. By our study, for the last sense codon CCG, the RFI of GFP(CCG) was 2.1 fold when the stop codon was UAA, but in comparison, the RFI was 1.1 fold when the stop codon was changed from UAA to UAG. For last sense codon TAG, the RFI of GFP(TAG) with the stop codon UAG was stronger than that with the stop codons UAA and UGA.
In order to find out the shrinkage law of cement stabilized macadam material under specific conditions, this paper studied the expansion and shrinkage properties of cement stabilized macadam material under two environmental conditions, five kinds of cement dosage conditions, suspended compacted type and skeleton compaced type based on the multi-dimensional expansion and shrinkage tester. Through the test comparison, it is confirmed that the water loss rate of cement stabilized macadam material increases with the increase of cement dosage, showing a general change rule of rising first and then stabilizing. The average increase of the total water loss rate of suspended compacted cement stabilized macadam at room temperature was greater than that of the skeleton compacted cement stabilized macadam. The dry shrinkage strain also follows the above trend. Either at room temperature or under the conditions of dry shrinkage box, the water loss rate of suspended compacted cemeny stabilized macadam is higher than that of skeleton compacted cement stabilized macadam , which can be up to 3.23% higher. By comparing the temperature shrinkage coefficient under the high and low temperature environment, the temperature coefficient of the skeleton compacted cement stabilized macadam is smaller than that of the suspended compacted cement stabilized macadam. The temperature shrinkage coefficient of the suspended compacted cement stabilized macadam increases by 5.56% on average for each 0.5% increase of the cement dosage, and the temperature shrinkage coefficient of the skeleton compacted cement stabilized macadam increases by 6.33% on average. Through the comparative analysis of tests, it can be found that the anti-reflection crack ability of the skeleton compacted cement stabilized macadam material is better, and the fine aggregate content should be strictly controlled in the construction.
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