为了探究了鲤(Cyprinus carpio)仔稚鱼的生长过程中主要消化酶活性变化规律,实验测定了鲤从孵化出膜到40日龄(日龄,Day after hatching)仔稚鱼期间的生长、可溶性蛋白含量和几种消化酶活性变化。结果显示:仔稚鱼全长以及体重在15日龄后...为了探究了鲤(Cyprinus carpio)仔稚鱼的生长过程中主要消化酶活性变化规律,实验测定了鲤从孵化出膜到40日龄(日龄,Day after hatching)仔稚鱼期间的生长、可溶性蛋白含量和几种消化酶活性变化。结果显示:仔稚鱼全长以及体重在15日龄后增速加快,特定生长率为14.81%。淀粉酶、脂肪酶、胰蛋白酶,糜乳蛋白酶、碱性磷酸酶以及氨基肽酶在1日龄仔鱼体内均能检测到活性。在仔稚鱼发育过程中,其可溶性蛋白含量先下降后上升。仔鱼摄食前消化酶的活性出现一定的上升,随着仔稚鱼消化系统发育以及营养方式的转变,其消化酶活性从3到25日龄处于不断的变化状态,而25日龄到实验结束鲤仔稚鱼的消化酶处于一种相对稳定的状态,标志着其消化功能趋于完善。根据不同发育时期鲤消化酶活性的变化,设计有机可腐化的材料制备人工鱼巢以提高人工鱼巢的生态修复功能,降低饥饿对仔稚鱼成活率的影响。展开更多
China is implementing the strategy of Rural Revitalization.Revitalizing idle and inefficient utilization courtyards is an important measure for rural revitalization.The evaluation of courtyard utilization efficiency i...China is implementing the strategy of Rural Revitalization.Revitalizing idle and inefficient utilization courtyards is an important measure for rural revitalization.The evaluation of courtyard utilization efficiency is the basis of determining the idle and inefficient utilization courtyards in order to revitalizing it.This study provided a reference for the optimal use of rural courtyard utilization and revitalization through the quantitative comprehensive evaluation of courtyard utilization efficiency and the classification of courtyard utilization types.Taking Shandong Province in Eastern China as study area,we selected eight surveyed villages by stratified sampling method.According to the scale of the villages,full survey and sample survey were used,while middleaged men who familiar with the courtyards were selected as the respondents.Through a household questionnaire survey and face-to-face interviews from2017 to 2018,578 questionnaires of rural courtyardsin eight villages were obtained.Then based on the functions of rural courtyard and land resource conditions,16 comprehensive factors were formulated,involving land conditions,construction conditions and economic benefits,to build the comprehensive evaluation index system of rural courtyard utilization efficiency.Next the index weight was determined by analytic hierarchy process,and the linear weighted regression model was used to evaluate the utilization efficiency of rural courtyard.Finally,the K-means clustering analysis was used to classify the utilization efficiency of courtyards.The results showed that among the eight villages,the average utilization efficiency of courtyards was moderate(one village was low,five were moderate,and two were high).The proportions of both idle and inefficiently utilized courtyards were high.There were three vital factors leading to the idle and low efficiency of rural courtyards.They were declining rural industries,limited arable land per capita,and more farmer workers.In this case,the utilization efficiency of courtyards should be improved by transferring rural land,developing secondary and tertiary industries,evaluating the development potential of villages,classifying and optimizing courtyard utilization,so as to make full use of idle and inefficient courtyards,increase the income of farmers and collectives and promote the revitalization of rural areas.展开更多
文摘为了探究了鲤(Cyprinus carpio)仔稚鱼的生长过程中主要消化酶活性变化规律,实验测定了鲤从孵化出膜到40日龄(日龄,Day after hatching)仔稚鱼期间的生长、可溶性蛋白含量和几种消化酶活性变化。结果显示:仔稚鱼全长以及体重在15日龄后增速加快,特定生长率为14.81%。淀粉酶、脂肪酶、胰蛋白酶,糜乳蛋白酶、碱性磷酸酶以及氨基肽酶在1日龄仔鱼体内均能检测到活性。在仔稚鱼发育过程中,其可溶性蛋白含量先下降后上升。仔鱼摄食前消化酶的活性出现一定的上升,随着仔稚鱼消化系统发育以及营养方式的转变,其消化酶活性从3到25日龄处于不断的变化状态,而25日龄到实验结束鲤仔稚鱼的消化酶处于一种相对稳定的状态,标志着其消化功能趋于完善。根据不同发育时期鲤消化酶活性的变化,设计有机可腐化的材料制备人工鱼巢以提高人工鱼巢的生态修复功能,降低饥饿对仔稚鱼成活率的影响。
文摘China is implementing the strategy of Rural Revitalization.Revitalizing idle and inefficient utilization courtyards is an important measure for rural revitalization.The evaluation of courtyard utilization efficiency is the basis of determining the idle and inefficient utilization courtyards in order to revitalizing it.This study provided a reference for the optimal use of rural courtyard utilization and revitalization through the quantitative comprehensive evaluation of courtyard utilization efficiency and the classification of courtyard utilization types.Taking Shandong Province in Eastern China as study area,we selected eight surveyed villages by stratified sampling method.According to the scale of the villages,full survey and sample survey were used,while middleaged men who familiar with the courtyards were selected as the respondents.Through a household questionnaire survey and face-to-face interviews from2017 to 2018,578 questionnaires of rural courtyardsin eight villages were obtained.Then based on the functions of rural courtyard and land resource conditions,16 comprehensive factors were formulated,involving land conditions,construction conditions and economic benefits,to build the comprehensive evaluation index system of rural courtyard utilization efficiency.Next the index weight was determined by analytic hierarchy process,and the linear weighted regression model was used to evaluate the utilization efficiency of rural courtyard.Finally,the K-means clustering analysis was used to classify the utilization efficiency of courtyards.The results showed that among the eight villages,the average utilization efficiency of courtyards was moderate(one village was low,five were moderate,and two were high).The proportions of both idle and inefficiently utilized courtyards were high.There were three vital factors leading to the idle and low efficiency of rural courtyards.They were declining rural industries,limited arable land per capita,and more farmer workers.In this case,the utilization efficiency of courtyards should be improved by transferring rural land,developing secondary and tertiary industries,evaluating the development potential of villages,classifying and optimizing courtyard utilization,so as to make full use of idle and inefficient courtyards,increase the income of farmers and collectives and promote the revitalization of rural areas.
