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It is very important of high-speed railway construction surveying and mapping. Especially the establishment of construction survey control network and searching aiming at layout, measurement, data processing of adjustment calculation of the horizontal control network and the elevation control network. The most important part is the establishment of CP II and CPIII control network. The elevation control mainly adopts second order leveling. Horizontal and elevation accuracy must to meet the requirements of high speed railway construction survey.

The purpose of this study was to determine the nutrient composition and AME n content of corn distillers dried grains with solubles (DDGS) to develop prediction equations for AME n in laying hens. Ten samples of DDGS ranging in ether extract (EE) from 21.8 to 177.8 g/kg (DM basis) were selected and were subsequently fed to laying hens to determine AME n content. A total of 176 62-week-old laying hens (Lohmann-Pink) were placed in metabolic cages (2 hens/cage) and were allotted into 11 dietary treatments (8 cages per treatment) according to hen-day egg production. Dietary treatments included a corn-soybean meal reference diet and 10 test diets. Each test diet was created by mixing the reference diet with 200 g/kg one of 10 DDGS samples at the expense of the energy-yielding ingredients (139.6 g/kg corn, 59.0 g/kg soybean meal, and 1.4 g/kg rapeseed oil). Experimental diets were fed in the 7-day adaptation period, followed by the 4-day total excreta collection period. Gross energy (GE) and crude protein (CP) of the experimental diets and excreta were determined to calculate AME n for each DDGS sample. On the DM basis, AME n of the 10 corn DDGS samples ranged from 729 to 2535 kcal/kg. Analyses were conducted to determine the GE, CP, EE, DM, crude fiber, neutral detergent fiber (NDF), acid detergent fiber (ADF), and ash content of the DDGS samples. Stepwise regression resulted in the following best-fit equation for AME n (DM basis) based on the coefficient of determination, SE, and the Mallows’ statistic (Cp): AME n , kcal/kg = 0.777 × GE (kcal/kg) − 5.39 × NDF (g/kg) (R 2  = 0.99; SE = 172; C p  = −3.37). These results suggested that the composition of corn DDGS may be used to predict AME n in laying hens. [ABSTRACT FROM AUTHOR]

The study aimed to determine the ileal phosphorus (P) digestibility (iPD) and the excreta P retention (ePR) of 5 monodicalcium phosphate (MCP) samples and 3 dicalcium phosphate (DCP) samples in broiler chickens and in Pekin ducks using the substitution method. A total of 720, 21-d-old Arbor Acres broiler chickens in experiment 1 and 720, 15-d-old Pekin ducks in experiment 2 were randomly allocated to 9 dietary treatments with 8 replicate cages (10 birds/cage) based on the similar mean body weight, respectively. The collection of excreta (for 72 h after a 3-d acclimation) and ileal digesta (after 6 d of feeding experimental diets) was done. The results showed the average iPD/ePR of MCP and DCP for broilers were 83.11%/74.52% and 75.34%/69.46% and for ducks were 79.37%/80.02% and 75.74%/76.44%, respectively. The iPD/ePR of MCP in broilers and the ePR of MCP in ducks were markedly higher (P < 0.05) than those of DCP. Our data suggest that using the substitution method to evaluate the bioavailability of feed phosphates has its own advantages; MCP has higher biological availability than DCP for broilers and ducks. [ABSTRACT FROM AUTHOR]

In this study, AlGaN/GaN high electron mobility transistors (HEMTs) with AlGaN back barriers (B.B.) were comprehensively investigated based on the different Al mole fractions and thicknesses in the design of the experiments. It was shown that the off-state leakage current can be suppressed following an increase of the Al mole fraction due to the enhancement of the back barrier height. Increasing the AlGaN thickness deteriorated device performance because of the generation of lattice mismatch induced surface defects. The dynamic on-resistance (RON) measurements indicated that the Al mole fraction and thickness of the B.B. both affected the buffer trapping phenomenon. In addition, the thickness of B.B. also influenced the substrate heat dissipation ability which is also a key index for high power RF device applications. [ABSTRACT FROM AUTHOR]