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排序方式: 共有58条查询结果,搜索用时 31 毫秒
1.
从高校扩大招生规模后,高职高专学校遇到招生难、办学难和择业难问题,结合实际,提出分析和解决问题的办法。 相似文献
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吴治礼 《江西农业大学学报》1997,19(3):78-81
综述了当前我国饲料工业国有饲料企业面临的因难和原因,提出了走出困境巩固发展有效途径的构想。 相似文献
4.
湘西自治州农业信息化的现状、困难与对策 总被引:5,自引:0,他引:5
龙世谱 《农业图书情报学刊》2007,19(8):187-190,192
通过对湖南湘西州农业信息化现状的调查,找出了存在的困难和问题,初步分析与探讨了解决问题的对策。 相似文献
5.
依据计算机化考试试题库中不同类型的试题,确定相应的信度、效度、难度、区分度的计算方法。通过对《数据库系统原理》课程的计算机化考试成绩计算,得到各类型题及考试的信度、效度、难度、区分度,并析得出《数据库系统原理》课程的计算机化考试质量较高,考试有效。 相似文献
6.
在社会主义新农村建设背景下,积极推进农村信息化建设具有重大的战略意义。自税费改革以来,安徽村干部在职能上发生了很大的变化,探究他们在农村信息化建设中面临的困境,有利于发挥村干部在农村信息化建设过程中的推动作用,提高我省农业信息化水平,加快我省社会主义新农村建设步伐。 相似文献
7.
考试制度的改革是高等学校教学改革的主要内容之一。华北地区高等农林院校近几年举行了统一命题考试,对考试本身质量的科学评价是改革考试的依据,考试命题的研究及考卷的分析探讨是教学改革的重要课题。本文针对这个问题对河北林学院91级的《高等数学》试卷进行了分析,用考试的效度、信度、区分度和难易度等4个质量指标来评估考试的质量。同时认为通过统考与兄弟院校交流了信息和经验,从而激励和促进了该课程的教学工作,使4年统考成绩呈上升趋势,实际上反映了该课程的教学质量在逐步提高。 相似文献
8.
Effect of dystocia on subsequent reproductive performance and functional longevity in Holstein cows 下载免费PDF全文
N. Ghavi Hossein‐Zadeh 《Journal of animal physiology and animal nutrition》2016,100(5):860-867
The objective of this study was to evaluate the effect of dystocia on the reproductive performance and functional longevity in Iranian Holsteins. Data consisted of 1 467 064 lactation records of 581 421 Holstein cows from 3083 herds which were collected by the Animal Breeding Center of Iran from April 1987 to February 2014. Reproduction traits in this study included interval from first to second calving, days open and days from first calving to first service. The generalized linear model was used for the statistical analysis of reproductive traits. Survival analysis was performed using the Weibull proportional hazards models to analyse the impact of dystocia on functional longevity. The incidence of dystocia had an adverse effect on the reproductive performance of dairy cows. Therefore, reproductive traits deteriorated along with increase in dystocia score (p < 0.05). The culling risk was increased along with increase in the score of dystocia (p < 0.0001). The greatest culling risk was observed in primiparous cows, small herds and low‐yielding cows (p < 0.0001). Also, the lowest culling risk was found for cows calving at the youngest age (<27 months), and cows with age at first calving >33 months had the greatest risk (p < 0.0001). The results of current study indicated that dystocia had important negative effects on the reproductive performance and functional longevity in dairy cows, and it should be avoided as much as possible to provide a good perspective in the scope of economic and animal welfare issues in dairy herds. 相似文献
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在学时压缩的情况下,让学生更好的掌握信号与系统课程成为教学的难度。针对这种情况,结合教学经验,从教学内容及教学方法、课程重点难点及实验教学方式3个方面,有针对性的提出了改革措施,以期达到教学与实际工程的衔接,提高电气信息类学生的工程应用能力。 相似文献
10.
Estimation of some productive and reproductive effects on longevity of beef cows using survival analysis 总被引:1,自引:0,他引:1
Longevity of beef cows defined as the length of productive life from first calving to culling was estimated in this study. Data from 1800 cows belonging to Hereford, Angus, Simmental, Charolais, Limousin and Blonde d' Aquitaine breeds were analysed using survival method. The results indicate effects of breed, calving season, and calving difficulty on longevity (P < 0.05); however, herd, age of the cow at first calving, sex and weaning weight of their calves did not affect (P > 0.05) the length of productive life. Hereford had significantly greater (10.3 years) estimated length of productive life than Angus (8.1 years), Simmental (7.9 years), and Charolais (7.1 years), which had similar estimated longevity. Limousin (5.9 years) and Blonde d' Aquitaine (5.2 years) were similar in estimated longevity, but less than the other breeds studied. Cows that calved first in spring or summer were estimated to have longer productive life (7.2 years and 9.9 years) and less risk of early culling than those calving in autumn (5.7 years) and in winter (5.1 years). Longer productive life (6.2 years) was estimated across breeds for cows calving without assistance or with a little assistance (6.9 years) compared to those needing veterinary assistance (2.8 years) or having stillbirth (4.6 years). The results highlight that breed, calving season and calving difficulty of beef cows may have important effects on length of productive life. Special attention should be devoted to these effects. 相似文献