排序方式： 共有17条查询结果，搜索用时 15 毫秒
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漳河水库由观音寺水库和鸡公尖水库通过半天然明槽相互连通组成，因受库水位观测、明槽输水计算、动库容计算误差等的复杂影响，以往多次建立的洪水预报方案均未达到可供应用的水平。在分析漳河水库入库洪水误差产生特点的基础上，通过建立抗误差产汇流预报模型和自适应实时校正技术，使漳河水库洪水预报方案平均确定性系数达91.09%，洪峰合格率达100%，峰现时间合格率达90.91%；观音寺水库洪水预报方案的平均确定性系数达90.63%，洪峰合格率达100%，峰现时间合格率达100%，终于建立了达到甲等水平的漳河水库洪水预报应用方案。 相似文献
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The effect of footrot on body weight and wool growth of sheep 总被引：1，自引：0，他引：1
Body weight and traits associated with production of wool were measured over a 2-year period between 1985 and 1987 in south-western New South Wales in a flock of Merino wethers experimentally infected with footrot. The disease was allowed to spread freely amongst 150 of the flock but kept at very low prevalence in the remaining 50 by preventive footbathing during transmission periods. Severe, underrunning footrot had a significant adverse effect on body weight, for each year of the trial. Body weight was most severely reduced at times of the year when footrot was spreading among animals and lesions were severe. The mean body weight of the infected group at the end of the 2 years of observation was 7.3 kg (11.6%) below that of the control group. Footrot also depressed wool growth, with the mean clean fleece weight of the infected group being 0.4 kg (8%) lighter than that of the controls at each of the 2 annual shearings. There were no consistent differences between the groups for the other wool characteristics measured. 相似文献
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Oil emulsion inactivated vaccine was prepared by susceptible embryos, with different strains of AEV. Four groups of normal chickens of 2 - 7 days of age were given injections for immunization, respectively. Another group was used as control. This study was expected to evaluate the immunological effect and discuss the immunological mechanism by means of five different experiments, i.e. the agar-gel precipitin test,the isolation of lymphokine, the isolation, purification and analysis of blood serum IgG, embryo-susceptibility test, and clinical and pathological examination. The results of these experiments indicated that oil emulsion inactivated vaccine is safe and effective. The chickens were normal when inoculated with AE strong virus after immunity at 4 and 37 weeks. Immunological mechanism is that the humoral immunity played an important role and celluar immunity exists, but it is not important in the process of the resistance to AEV. 相似文献
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在香梨 4年生幼林园内 ,进行了常规沟植、渠道内外两行树木的新梢生长量、叶片生长状况和蒸腾速率、气孔阻抗、叶温、叶温与气温差日变化的测定。结果表明 ,渠外行的各项生理指标均好于沟植和渠内行。揭示了影响树木生长的水分生理状况和过程。提出了生产中要提倡渠外行栽种香梨 ,保持沟植香梨 ,放弃渠内行栽植香梨的生产模式理论依据。 相似文献
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Abdullah Y. Abdullah Marwan M. Muwalla Rasha I. Qudsieh Hosam H. Titi 《Tropical animal health and production》2010,42(2):293-300
The objective of this study was to evaluate the effects of replacing the protein source of soybean meal (SBM) with different levels of bitter vetch seeds (BVS) in the diets of finishing Awassi ram lambs on performance, and carcass characteristics. Diets were designed based on replacing SBM with BVS as a percentage of the diet. Diets were: control (0% BVS), substituting 5% of SBM (5% BVS), 10% of SBM (10% BVS) and the entire SBM in the ration with BVS (15% BVS). Forty eight lambs (18.74?±?3.95 kg initial body weight and 70 days of age) were randomly assigned to 4 treatment diets (12 lambs/treatment). Lambs were given an adaptation period of 10 days and the experiment lasted for 84 days. At the end of the trial, a digestibility experiment was performed and 6 lambs from each treatment were slaughtered to evaluate carcass characteristics. Average daily gain tended (P?=?0.07) to be higher for lambs fed 10% BVS when compared to the other diets. Neutral detergent fiber digestibility was higher (P?<?0.01) in control diet compared to the other diets. Fat depth (C) and leg fat depth (L3) tended (0.05?<?P?<?0.1) to be affected by BVS levels in the diet. Leg total lean % was the highest (P?<?0.05) in 5% BVS and 10% BVS diets. These results suggest that substituting SBM with BVS in the diets did not influence performance or carcass characteristics of lambs. However, the cost of ration formulation decreases since SBM is a very expensive component of the ration. 相似文献
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本试验以安装有永久性瘤胃瘘管的3头荷斯坦奶牛为动物模型,利用体外批次培养法,比较研究了玉米青贮、苜蓿干草、羊草和玉米秸秆等四种单一粗饲料体外发酵效果。本试验以GI为指标对粗饲料品质进行测定,GI指数分别为9.05MJ、48.71MJ、9.41MJ和1.81MJ。结果表明:粗饲料品质对培养液pH值有显著影响(P<0.05),平均值分别为(6.436、.476、.506、.41),随着培养时间的延长,各组pH值均呈下降趋势,其中秸秆组下降幅度最大,24h培养液pH值为6.27,羊草组pH值下降幅度最小;粗饲料品质对培养液NH3-N、产气量、VFAs和BCP产量有显著影响(P<0.05),其中苜蓿最高,秸秆最低,青贮NH3-N和VFA产量高于羊草,羊草产气量和BCP产量高于青贮;各组培养液乙/丙比例平均值大小顺序为羊草>秸秆>苜蓿>青贮,平均值分别为(2.132、.042、.001、.73)。 相似文献
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Qudsieh HY Yusof S Osman A Rahman RA 《Journal of agricultural and food chemistry》2002,50(6):1615-1618
A study was conducted to determine the effect of sugarcane maturation on the contents of chlorophyll, tannin, and polyphenol oxidase (PPO) activity and on color change of sugarcane juice. The maturation period of the cane studied was between 3 and 10 months after planting. Different parts of the cane, namely, the top, middle, and bottom portions, were analyzed. Results obtained indicated that there were significant (P < 0.01) decreases in total chlorophyll a and b and tannin contents during maturity followed by slower rates of decrease of both parameters at the end of maturity stages. There were no significant differences (P > 0.05) in chlorophyll and tannin contents between the middle and bottom portions. On the other hand, the top portion of the stem had a significantly (P < 0.01) lower concentration of chlorophyll and a significantly (P < 0.01) higher content of tannin. PPO activity of sugarcane juice was determined using chlorogenic acid as a substrate. There was a highly significant difference (P < 0.01) in PPO activity of cane juice during maturity. PPO activity was high at the early development stage, decreased during maturation, and then remained relatively constant at the end of maturity. PPO activity was higher when chlorogenic acid was used as substrate. There were also significant differences (P < 0.01) in juice color (L*, a*, b* values) from different portions at different maturity stages. At the early stages, the color of extracted juice was dark, and then the juice turned to yellowish green during maturity. The decrease in green color or the increase in the yellow color could be associated with the decline in chlorophyll. The overall color change (DeltaE) at maturity indicated that the color of the middle and bottom portions was lower than that of the top portion. 相似文献