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The ionization chamber tritium monitor is the most important online monitoring equipment for monitoring the concentration of tritium in the air. In order to solve the problem of quantity value transmission, the calibration technology of ionization chamber tritium monitor was studied. The laboratory calibration device of tritium monitor is established according to the mass flow method. The reference tritium gas for calibration is diluted and prepared by controlling the volume of standard tritium gas filled into the calibration device. The prepared reference tritium gas is used to calibrate the ionization chamber tritium monitor. At the same time, the influence factors of the calibration process on the calibration results are studied on the developed laboratory calibration device; the expanded uncertainty of reference tritium gas concentration prepared by laboratory calibration device is 3.2%-3.6%(k=2); when tritium activity concentration is 3.10×103-1.98×105 Bq/L, the response linearity of SP1400 tritium monitor to tritium gas activity is good(r2=0.999 3), the calibration factor is 0.97, and the standard synthetic uncertainty is 4.3%-5.0%. The laboratory calibration device of tritium monitor can prepare tritium gas with different activity concentrations. The calibration method is simple to operate and easy to popularize, which can meet the needs of tritium monitor calibration.

The study was to explore the optimal row space configuration for high-quality and efficient production of 'Fuyan 70' in Hulun Buir area. A single factor randomized block design was used to study the effect of row spacing of 15, 20, 25, 30 and 35 cm on yield and silage quality. The grey relational degree was used for comprehensive evaluation. The results showed that row spacing configuration had significant effect on dry matter yield and silage quality ( P<0.05). The maximum dry matter yield of 'Fuyan 70' was 10 629 kg/hm2 when the row spacing was 20 cm. DM content was the highest (36.79%) at row spacing was 25 cm, CP content was the highest (13.40%) at row spacing of 30 cm, EE content was the highest (2.75%) at row spacing of 30 cm, ADF and NDF content increased significantly with the increase of planting row spacing, and ADF content was the lowest (25.11%) at row spacing of 20 cm. Grey correlation analysis showed that the comprehensive evaluation of row spacing of 20 cm was the highest, the correlation degree was 0.948. The experiment indicates that when planting row spacing is 20 cm, 'Fuyan 70' has high dry matter yield and excellent silage quality, which is suitable for planting in Hulun Buir area. [ABSTRACT FROM AUTHOR]

The study was to study the effect of natural garlic essential oil added to drinking water on immune indexes of chicks infected with Eimeria tenella. Four hundred Nongda No. 3 grain egg chicks were randomly divided into five groups, with four replicates in each group and 20 chicks in each replicate, namely healthy control group, infected group and low, medium and high dose of natural garlic essential oil groups (natural garlic essential oil was added to drinking water at 0.04, 0.06, 0.08 mL/L, respectively). At 16 d of age, except the healthy control group, the other groups were given Eimeria tenella 5 x 104 oocysts per chick. The challenge period lasted for 7 d and the experiment lasted for 23 d. The results showed that the final weight and average weight gain of laying chicks in HC group were significantly higher than those in IN group, L group and H group ( P<0.05). The oocyst value in IN group and L group was the highest, both being 40. The lowest oocyst value was 0 in HC group. At 20 d of age, the thymus index, IgM and IgG of laying chicks in M group was significantly higher than those in other groups (P<0.05). At 23 d of age, the serum IgA content of laying chicks in M group was significantly higher than that in other groups ( P<0.05). The study indicates that adding 0.06 mL/L natural garlic essential oil to drinking water has a function to improve the immune function of egg chicks. [ABSTRACT FROM AUTHOR]

The Hulunbuir Leymus chinensis Meadow Grassland is a grassland formation at the eastern end of the Central Asian Grassland Subregion in the Eurasian Grassland Region. It is one of the representative types of meadow grasslands, and its grassland ecosystem is undergoing dual pressures from human interference such as grazing and climate change, resulting in varying degrees of degradation. Based on the correlation between grazing disturbance intensity and grassland biomass, this paper selected the natural Leymus chinensis meadow inside and outside the fence in Hulunbeier area to carry out long-term observation on the composition of plant community in the field (enclosed in 2005), obtained the composition data of plant community in the meadow grassland (2009-2015), and studied the response of community coverage, community abundance, and community height to grazing intensity on this basis. Research has shown that enclosure significantly increases the aboveground biomass of grasslands, and the degree of improvement is positively correlated with the duration of enclosure; Meanwhile, moderate grazing interference will not cause a decrease in the abundance of grassland communities. Among them, the latter conclusion has enlightening significance for the grassland ecological compensation mechanism currently aimed at balancing grassland ecological protection and productivity improvement. Proper enclosure and grazing prohibition in severely degraded areas can help protect and build grasslands, partially reflecting the necessity of ecological compensation. At the same time, further analysis also indicates that there is still room for exploration in optimizing relevant policies. This study helps to deepen the understanding of grazing response and feedback mechanisms in grassland ecosystems, and can provide scientific basis for the protection and sustainable utilization of grassland ecosystems. [ABSTRACT FROM AUTHOR]