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1.
In this study, the environmental indicators(including temperature, light, air relative humidity and CO_2 concentration) of facility watermelon in Beijing area were monitored with US350 environmental sensor during the whole growth period. The results showed that in the solar greenhouses in Beijing area, the average air temperature was in the range of 10.67-29.95 ℃ during the whole growth period of watermelon, the average soil temperature ranged from 16.92 to 35.10 ℃, the average light intensity changed from 268.37 to 13 842.60 lx, the average air relative humidity ranged from 52.40% to 94.26%, and the average CO_2 concentration was in the range of 455-631 ml/m~3; and in the spring greenhouses in Beijing area, the variation range of average air temperature was 14.05-29.84 ℃ during the whole growth period of watermelon, the average soil temperature ranged from17.47 to 28.12 ℃, the average light intensity was in the range of 55.80-12 858.64 lx, the average soil moisture content ranged from 18.19%-34.56%, the variation range of average air relative humidity was 20.72%-96.26%, and the average CO_2 concentration was in the range of 351-544 ml/m~3.  相似文献   

2.
Laboratory aerobic incubation was conducted for 161 d to study N mineralization and the changes of organic N fractions of nine different manures(3 chicken manures, 3 pig manures and 3 cattle manures) from different farms/locations. Results indicated that significant(P〈0.01 or P〈0.001) difference existed in N mineralization between manures. The rapid N mineralization in manures occurred during 56 to 84 d of incubation. First order exponential model can be used to describe N mineralization from chicken manures and pig manures, while quadratic equation can predict mineralization of organic N from cattle manures. An average of 21, 19 and 13% added organic N from chicken manure, pig manure and cattle manure was mineralized during 161 d of incubation. Amino acid-N was the main source of N mineralization. The changes of amino acid-N together with ammonium N could explain significantly 97 and 96% of the variation in mineralized N from manured soils and manures. Amino acid-N and ammonium N are two main N fractions in determining N mineralization potential from manures. Amino acid-N contributed more to the mineralized N than ammonium N.  相似文献   

3.
In this study, the effects of two types of premixed materials with different combinations of trace elements on the production performance and antioxidant capacity of simmental beef cattle were examined.Fifteen healthy simmental beef cattle of similar weight(approximately 330 kg), the same age(12 months), without castration, and a good physique were divided into three groups, with five beef cattle in each group.Food of GroupⅠ beef cattle was supplemented with a commercially marketed 5% compound trace element premixture for fine beef cattle.Food of GroupⅡbeef cattle was supplemented with a 5% compound microelement premixture for beef cattle that was designed to address local nutrient deficiencies and surpluses.In the blank control group, the beef cattle were not fed a premixture.The pretest period was 15 days, and the test period was divided into prefattening(45 days) and postfattening(45 days) stages.Body weight and body size indices were recorded at 1, 2 and 3 months, and blood samples were collected regularly.In GroupⅠ, the daily weight gain increased significantly by 15.7% compared with that of the control group.The largest daily weight gain was in Group Ⅱ, which increased by 31.6% compared with that in the control.During the test period of 90 days, the body size indices of the three different groups increased in different months, with significant increases in the indices for both test groups compared with those of the control.In GroupⅠ, the activity of CP, the total activity of SOD and Cu-Zn-SOD increased significantly(p0.05) compared with those in the control group, with a highly significant increase observed in GSH-PX activity(p0.01).In GroupⅡ, the increases in the activity of CP and the total activity of SOD and Cu-Zn-SOD were highly significant compared with those in the control group(p0.01).In addition, a significant increase was observed in GSH-PX activity(p0.05).Based on pretest results, the concentrations of Cu, Zn, Mo, Mn, Se and Co in the blood of experimental beef cattle were lower than those of the normal range.After feeding for 90 days, the concentrations of Cu, Zn, Mo, Mn, Se and Co in the blood of GroupsⅠ andⅡ were significantly higher than those in the control group(p0.05).The concentrations of elements in the blood of Group II were close to the appropriate levels.Thus, the effects of the specifically designed compound microelement premixture on the prevention of nutrient imbalances and control of beef cattle nutrition metabolism and the production of fattened beef cattle were significant.  相似文献   

4.
Employing the pot experiment of the complete random block design with 6 replications,four varieties of japonica rice (Fujisaka 5,Honenwase,Akitakomachi and Taichung 65) were used to study the varietal differences in leaf nitrogen content (LNC) and leaf area during mature period,their relation and effects to the ripening rate.The results showed that (1) thee were varietal differences in LNC at the heading stage and the LNC decrease rate during the matur period,the high LNC at the heading stage was related to the rapid LNC decrease.(2) There were two phases of the leaf area changing process during the mature period,first was the stable,and second was the decreased phase.There was varietal difference in the critical time of phase 1 and phase 2.The hign leaf area in the phase 1 was in relation to the rapid leaf area decrease in the phase 2.It was not found that there was relation between the leaf quality and quantity.(2)It wa unfavorable to the ripening rate for the high leaf area at the heading stage and the rapid decrease of the leaf area during the mature period.(4)It was put forward that the super high yield rice variety should possess the not very high leaf area and high LNC at the heading stage,slow senescence in the leaf area during the mature period.  相似文献   

5.
In this study, the insecticidal active substance of the fruiting body of Paecilomyces cicadae (Miquel) Samson that can kill the larvae of Plutella xylostella (Lepidoptera: Plutellidae) was isolated and purified by combined separation with biology experiments for the first time. By means of bioactive guided isolation of 40% ethanol-H2O, dichloromethane, ethyl acetate, n-butyl ethanol, macroporous adsorption resin column, high performance liquid chromatography, and sephadex A-20 column, the insecticidal active compound was purified,and a white powder compound was obtained. The compound was active against the third instar larvae ofP. xylostella in 24, 48, and 72 h at the concentration of 10.0 mg mL-1 with a corrective mortality of (95.1 ± 1.8), (97.7 ± 1.6), and (99.1 ± 1.7)%, respectively. The compound was strongly sensitive to the larvae. It was stable at acid environment, and was not sensitive to pepsin, and other chracteristics were studied.  相似文献   

6.
A study carried out for assessment of acaricide for control and how to show resistance of hard tick (Ixodidae) with some types of acaricide which available in Sulaimani marked froro February to April 2012, isolated 80 cattle (local breed) naturally infested with hard tick. Six hundred and fifteen ticks min7 tick/cattle including three genera species were collected and identified, the highest Boophilus spp. followed by Hyalomma spp., and Rhipicephalus spp. were less frequent species collected. Experimental cattle divided into four groups each group content 20 cattle, treatment with four types acaricide and their average of infestation in cattle with Boophilus spp. 33 (41.25%) as the commonest, followed by Hyalomma spp. 31 (75.38%), Rhipicephalus spp. 11 (13.75%) and 5 (6.25%) found mixed infested with Boophilus spp. and Hyalomma spp. 65 (81.3%) of cattle samples had emaciation and skin lesions. According to site of infestation, it showed that inguinal region was the most common predilection site for the ticks. Observed the genera Boophilus spp., there were highly significant differences (12.52%) between different tick species when calculated by general test (LSD). The objective of this study was to estimate and compare these acaricide to control hard tick, and there was highly significant relation between different species of hard ticks when treated by these acaricide, according to the chi-square tests. The activities of the acaricide through the time of application were different on the tick genera species. Diazinon (60%) and carbamate (saven 85%) has been a greater degree than other acaricide resistance, while shows the activity of both acaricide injectable ivermactin and cypromethrein through the early time on all species. The results of the study otherwise provide encouraging possibilities for the potential use recommended dose with both acaricide ivermactin-l% and cypromethrine-10%.  相似文献   

7.
Based on climate data from 254 meteorological stations, this study estimated the effects of climate change on rice planting boundaries and potential yields in the southern China during 1951-2010. The results indicated a signiifcant northward shift and westward expansion of northern boundaries for rice planting in the southern China. Compared with the period of 1951-1980, the average temperature during rice growing season in the period of 1981-2010 increased by 0.4°C, and the northern planting boundaries for single rice cropping system (SRCS), early triple cropping rice system (ETCRS), medium triple cropping rice system (MTCRS), and late triple cropping rice system (LTCRS) moved northward by 10, 30, 52 and 66 km, respectively. In addition, compared with the period of 1951-1980, the suitable planting area for SRCS was reduced by 11%during the period of 1981-2010. However, the suitable planting areas for other rice cropping systems increased, with the increasing amplitude of 3, 8, and 10%for ETCRS, MTCRS and LTCRS, respectively. In general, the light and temperature potential productivity of rice decreased by 2.5%. Without considering the change of rice cultivars, the northern planting boundaries for different rice cropping systems showed a northward shift tendency. Climate change resulted in decrease of per unit area yield for SRCS and the annual average yields of ETCRS and LTCRS. Nevertheless, the overall rice production in the entire research area showed a decreasing trend even with the increasing trend of annual average yield for MTCRS.  相似文献   

8.
Aiming at less and un-uniform distribution rainfall problems, the serious draught in spring, low crop production and water efficiency in sandy soil area of Heilongjiang Province, the experiment of alternative furrow irrigation was conducted in Dumeng County in 2009. The purpose of the experiment was to find the water consumption law and its influence on maize yield. The results showed that the highest water consumption was during the heading stage and the highest daily consumption of water was during the filling stage. The stimulation effect of alternative furrow irrigation on yield was obvious in the appropriate irrigation level. The best irrigation pattern for the highest yield was as follows: the seedling stage was 325 m3. hm^-2; the jointing stage was 400 m3-hm^-2; and the filling stage was 288 m3- hm-2. The water consumption during each growing period was that the seedling was 38.85 mm; the jointing was 108.11 mm; the heading was 124.39 ram; the filling was 88.96 ram; the milk was 60.21 ram; and the harvesting was 47.89 mm.  相似文献   

9.
[Objective] The aim was to analyze the correlation between tree-ring width of Picea crassifolia in the east of Qilian Mountains and the precipitation, temperature and the normalized difference vegetation index (NDVI). [Method] The correlation analysis and the regression analysis were used in this study. [Result] The tree-ring width was significantly correlated with the autumn precipitation and the spring average NDVI. The conversion equation between tree-ring width and spring NDVI (R2 = 48.5% , R2adj =46.2% , F =21.627, P <0.001) was developed and NDVI sequence was reconstructed during the period 1915 -2007. The drought in the 1920s was pronounced. Vegetation cover in the Qilian Mountains increased during the period 1922-1934, 1940-1957, 1965-1969, 1984-1988 and 1995-1997, but decreased during 1935 -1939, 1958 -1964, 1970 -1983, 1989 -1994 and 1998 -2005. [Conclusion] The reconstructed NDVI showed the drought evolution in the study area.  相似文献   

10.
Knowledge of the changes in cattle pelvic symphysis during gestation and obstetrics gives valuable information about the age of optimal primary calving of cows. The aim of the study was to investigate the histological changes of pelvic symphysis in Estonian Holstein-Frisian's (EHF) of different ages. Eight EHF cows up to five years of their age were divided into three age groups: calved, in-calved and after calved bovines. Material for histological and histochemical investigation was taken from four places: (1) cranial part ofpubic bone; (2) pubo-ischiadic junction; (3) symphyseal eminence; (4) body of the interischiadic bone. In all study-groups, the cranial part of pubic bone consisted of cartilage. In pubo-ischiadic junction of calves connective tissue proper, fibrous and hyaline cartilage were noted. In in-calved cattle with gestation of 4-5 months and in after calved cattle group hyaline cartilage and bone tissue were noted, however in in-calved cattle with gestation of 7.5 months fibrous cartilage and connective tissue proper prevalated. In sympyseal eminence of calves connective cartilage osseous tissue was present. The region of interischiadic tissue proper and cartilage were noted; in other groups besides bone of calves consisted of connective tissue proper and fibrous cartilage, meanwhile in in-calved and after calved EHF's in the region hyaline cartilage and osseous tissue prevalated. These preliminary results demonstrate that the main changes in the pelvic symphysis histology, retardation of ossification, of EHF kines occur during the second-half of gestation in the pubo-ischiadic junction.  相似文献   

11.
In this study, various factors of ELISA for detection of sulfamethazine residues were explored, the coating antigen was diluted to 1:400, the best coating condition was at 4℃ overnight, the working concentration of HRP-IgG enzyme conjugate was 1 : 7 000. The pre-incubation time and incubation time was 30 min and 120 min, respectively, the substrate solution working time was 20 min. Two moL · L^-1 H2SO4 was used to stop the reaction and checked. A standard curve of direct competitive ELISA had been established to detect the sulfamethazine residues in milk. The detection limit of this method was 1.97 ng · mL^-1. The mean concentration of sulfamethazine required to inhibit 30% antibody was 7.1 ng · mL^-1. The linear range of the detection was 5-200 ng · mL^-1. The recovery ratio was between 73.20% and 91.16%. The CV% of within array and between arrays was less than 10%.  相似文献   

12.
The laws of water consumption in corn,peanuts and millet on the semi-drought area of western Liaoning Province were studied through the FAO-Penman Monteith method and the water balance method.Among three corps,the amount of the day water demand,the whole growth period water demand and the soil water deficit of corn were all the largest.At the same time,its degree of agreement between the water demand and the level of precipitation was the worst,and its average in crop coefficient was larger.The amount of th...  相似文献   

13.
Probiotics which can provide potential health benefits for consumers and prevent disease, is the most important research field for functional food in the future. It is the key point that how much the count of bacteria and how long it can preserve. Freeze-drying skill is one of the best preservation methods, but it's defect that damage to biological systems can be attributed to changes in the physical state of membrane lipids or/and changes in the structure of sensitive proteins and the decreased survival rate. This work used pretreatment methods-cold shock and hot shock to reduce the damage to bacteria during freeze-drying. Using unpretreated samples as control, aspects of cold shock or heat shock. The response of Enterococcous faecalis A31 was investigated during lag phase, the middle of exponential growth phase and the terminal of exponential growth phase. The results suggested that when cold shock, the shock protein concentration produced by treated sample within 2 h during the middle of exponential growth phase was higher than 4, 8, 24 h, The concentration of shock protein produced by treated sample at 10 ℃ was higher than 20℃, The concentration of sample protein at the middle of exponential growth phase was higher than that at the terminal of exponential growth phase. After one-month storage, the survival rate at 10℃ was better than 20 ℃ and 4 ℃ comparatively. The survival rate at (6 h) 4 ℃/24 h (lag period) was higher than (10 h) 4 ℃/24 h (the middle of exponential growth phase), and the effect of 10 ℃ /8 h shock treatments was best during the middle of exponential growth phase, when hot shock, The concentration of heat shock proteins produced was not obvious, and survival rate was higher at 45℃, 30 min than at 45 ℃, 60 min.  相似文献   

14.
[Objective] The research aimed to provide basic files and theoretical guidance for constructing sluicing-siltation dam using soil with high clay content soil.[Method] The soils of Dagou basin near Xiwu Village of Baishui County,Shaanxi Province were taken as experimental materials.pvc pipes with same height and diameter were used to construct testing model for dynamically determining settlement,shear strength,wet density of grouting bulk under 2 different grouting speeds(15 cm/d and 25 cm/d).[Result] Under different grouting speeds,general change trend was similar during grouting course.The subsidence,deformation,shear strength and wet density increased with the increase of grouting speed.Five or six days after grouting,daily displacement under 25 cm/d grouting speed was fewer than that under 15 cm/d grouting speed.[Conclusion] The increase of grouting speed could shorten the time for reaching the same subsidence,deformation,shear strength and wet density and increased displacement at the initial stage of grouting,however,with the increase of grouting time,lower grouting bulk was bad for displacement at later grouting period because it was near impermeable layer.  相似文献   

15.
泥浆土壤特性动态检测(英文)   总被引:3,自引:0,他引:3  
[Objective] The research aimed to provide basic files and theoretical guidance for constructing sluicing-siltation dam using soil with high clay content soil.[Method] The soils of Dagou basin near Xiwu Village of Baishui County,Shaanxi Province were taken as experimental materials.pvc pipes with same height and diameter were used to construct testing model for dynamically determining settlement,shear strength,wet density of grouting bulk under 2 different grouting speeds(15 cm/d and 25 cm/d).[Result] Under different grouting speeds,general change trend was similar during grouting course.The subsidence,deformation,shear strength and wet density increased with the increase of grouting speed.Five or six days after grouting,daily displacement under 25 cm/d grouting speed was fewer than that under 15 cm/d grouting speed.[Conclusion] The increase of grouting speed could shorten the time for reaching the same subsidence,deformation,shear strength and wet density and increased displacement at the initial stage of grouting,however,with the increase of grouting time,lower grouting bulk was bad for displacement at later grouting period because it was near impermeable layer.  相似文献   

16.
Dynamic Monitoring of the Mud   总被引:2,自引:0,他引:2  
[Objective] The research aimed to provide basic files and theoretical guidance for constructing sluicing-siltation dam using soil with high clay content soil.[Method] The soils of Dagou basin near Xiwu Village of Baishui County,Shaanxi Province were taken as experimental materials.pvc pipes with same height and diameter were used to construct testing model for dynamically determining settlement,shear strength,wet density of grouting bulk under 2 different grouting speeds(15 cm/d and 25 cm/d).[Result] Under different grouting speeds,general change trend was similar during grouting course.The subsidence,deformation,shear strength and wet density increased with the increase of grouting speed.Five or six days after grouting,daily displacement under 25 cm/d grouting speed was fewer than that under 15 cm/d grouting speed.[Conclusion] The increase of grouting speed could shorten the time for reaching the same subsidence,deformation,shear strength and wet density and increased displacement at the initial stage of grouting,however,with the increase of grouting time,lower grouting bulk was bad for displacement at later grouting period because it was near impermeable layer.  相似文献   

17.
A real-time RT-PCR assay using Taq Man-MGB probes was developed to detect and type the bovine viral diarrhea virus(BVDV) in cattle.Universal primers and Taq Man-MGB probes were designed from the 5′-untranslated region of known pestiviral sequences.Prior to optimizing the assay, c RNAs were transcribed in vitro from the BVDV 1 and BVDV 2 RTPCR products to make standard curves.The detection limit of the assay was 1.72×102 copies for BVDV 1 and 2.14×102copies for BVDV 2.The specificity of the assay evaluated on several BVDV strains including bovine herpesvirus 1(BHV 1), foot and mouth disease virus(FMDV) and several classical swine fever virus(CSFV) strains showed specific detection of the positive virus over 40 cycles.The assay was highly reproducible with the coefficient of variance ranging from 1.04 to 1.33% for BVDV 1 and from 0.83 to 1.48% for BVDV 2, respectively.Using this method, we tested a total of 2 327 cattle from three dairy farms for the presence of BVDV persistently infected(PI) animals.In this assay, each RT-PCR template contained a mixture of ten samples from different animals.The occurrence rate of PI cattle in three farms ranging from 0.9 to 2.54% could represent partly the PI rates in cattle farm in China.In conclusion, using our real-time PCR assay, we could effectively detect and type BVDV and identify PI cattle in a rapid and cost-effective manner.  相似文献   

18.
To assess the risks of forchlorfenuron after application, a residue analysis method for ferchlorfenuron in cucumbers and the red soil of Southern China was established, and the dissipation behavior and residue characteristics of forchlorfenuron were studied under field conditions. The field trials, including dissipation and residue experiments, were conducted in Hunan, Yunnan and Hainan Provinces. Forchlorfenuron was applied at 32 a.i.g ha-1 rate for the dissipation study and both 21 and 32 a.i.g ha-1 for the residue study. Representative cucumbers and soil samples were collected at predetermined intervals for HPLC for UV-detector analysis. The average recoveries of the method were 80.8%-92.0% with coefficients variation (CV) between 0.4% and 11.8%. The detection limit of forchlorfenuron in cucumbers and soil samples was 0.003 mg · kg-1 and the minimum detectable amount was 3.0×10-10 g. The half life of forchlorfenuron in cucumbers in the three provinces changed as: Yunnan (5.50 days), Hunan (5.88 days), and Hainan (6.53 days) and in the soil was observed: Hainan (6.54 days), Hunan (7.64 days), and Yunnan (8.39 days). The maximum terminal residue in cucumbers at 32 a.i.g ha-1 rate after 5 days was 0.009 mg · kg-1 (Yunnan) followed by 0.0085 mg · kg-1 (Hainan) and 0.0082 mg · kg-1 (Hunan) which was below MRL value of 0.01 mg · kg-1 established by the USA, EPA. So a waiting period of 5 days should be established after spaying on cucumbers to avoid hazard to human beings.  相似文献   

19.
The test analyzed the regularity of biosynthesis and degradation of the main functional components, such as zeaxanthin, β-carotene, and esterified carotenoids in the fruit of Lycium barbarum L. in order to provide theoretical basis for improvement of processing condition, appearance quality, and preservation of carotenoids. RP-HPLC was adapted to assay the changes of the main carotenoids of the different harvested stage fruit during the drying processing. Quantification was realized using external standard with gradient elution. The results showed that zeaxanthin and β-carotene contents in fruits increased dramatically, 2-22 times that of fresh fruits at the beginning of the drying period. In the middle of drying period, degradation occurred to a some extent, and the fall fruit degraded to a large extent. At the end of drying period, zeaxanthin and β-carotene contents increased to a little extent until a balanced state is obtained. Zeaxanthin dipalmitate content had a total degradation to more than 40% at the beginning of the drying period, and increased a little at the middle period, then reached a balanced state finally. The total carotenoid content analysis showed that the summer fruit had higher carotenoid content than the fall fruit. The experiments demonstrated zeaxanthin and β-carotene contents in fruits increased and zeaxanthin dipalmitate decreased during the drying process, which had an effect on the production appearance.  相似文献   

20.
Using the split plot and multi-quadric regressive orthogonal cross-course rotary combination design, corn variety Denghai 6‘s yield and yield components, important colony quality and physiological index, microclimate index in field and technical planting for high yield were studied. Cultivation for high yield showed that Denghai 6 had the great potential of increase yield. The average yield of two years was 12510kg/ha for 13.85ha, the highest grain yield (754.7m2) was 15477kg/ha. The climatic conditions can meet the needs for high yield during the whole growth stage of corn in the mountain area of Northwest Guizhou.  相似文献   

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