水是限制和维系生物活动的主要因子,水文连通性与诸多生态过程联系紧密。作为表征水循环过程中物质、能量和生物体在景观单元之间传输的过程,水文连通性建立了地表水循环过程中景观单元物质与能量流之间的相互联系。运用文献计量方法,以...水是限制和维系生物活动的主要因子,水文连通性与诸多生态过程联系紧密。作为表征水循环过程中物质、能量和生物体在景观单元之间传输的过程,水文连通性建立了地表水循环过程中景观单元物质与能量流之间的相互联系。运用文献计量方法,以Web of Science数据库及CNKI数据库为数据源,检索国内外水文连通性相关研究文献,运用Bibexcel、Ucient和Citespace等软件分别得到高频词、关键词共现网络可视图,在此基础上梳理国内外水文连通性研究进展。研究结果表明:围绕水文连通性,国内外发文量均呈现上升趋势,自1990年以来,国外水文连通度方面的研究与国内相比起步较早,且增长幅度较大;从关键词频上看,国外多偏重于不同类型生态系统结构功能变化对水文连通性的研究,国内则多偏重于河湖生态系统水系连通演变的研究;爆发词词频分析显示水文连通性与气候变化、生物多样性以及生态系统服务一度成为该领域研究热点;根据共现网络可视图,梳理国内外研究方向,水文连通性与生态过程、不同类型生态系统水文连通性对物质传输的影响,生态系统结构和功能的变化对水文连通性的影响等方面是当前的研究热点。开展不同尺度水文连通性制图,地下水依赖型生态系统水文连通性表征,基于地理信息技术与长期野外监测资料开展多尺度水文连通性定量评估和模型模拟是未来水文连通性研究的趋势。展开更多
[Objective]The paper was to investigate the mechanism of Bacillus coagulans preparation in improving production performance of laying hens in late period of laying.[Method]A total of 648 individuals of"Jingfen 1&...[Objective]The paper was to investigate the mechanism of Bacillus coagulans preparation in improving production performance of laying hens in late period of laying.[Method]A total of 648 individuals of"Jingfen 1"laying hens(66 weeks of age)in late period of laying were randomly divided into four groups,six replicates each group,and each group had 27 individuals of laying hens.The laying hens in control group were fed with basal diet,and those in experimental groupsⅠ,Ⅱ and Ⅲ were fed with the basal diets added with 3.33×10^6,1×10^7,3.33×10^7 CFU/g B.coagulans,respectively.The pretrial lasted one week,and the formal test lasted eight weeks.[Result]Compared with the control group,the laying rate in group Ⅰ increased significantly,and the feed-gain ratio in experimental group Ⅱ decreased noticeably while the spleen index increased remarkably;the alkaline phosphatase activities and blood calcium content in experimental groups Ⅰ,Ⅱ and Ⅲ increased significantly(P<0.05),while the triglyceride content decreased remarkably(P<0.05);the urea content in experimental groups Ⅰ and Ⅱ decreased obviously(P<0.05).Adding B.coagulans significantly increased the specific activity of amylase,lipase and protease in various intestinal mucosa of small intestine(P<0.05);adding B.coagulans significantly increased the content of follicle-stimulating hormone(FSH)and estradiol(E2),and significantly increased the mRNA expression of follicle stimulating hormone receptor gene(FSHR).[Conclusion]B.coagulans preparation could significantly improve the production performance of laying hens in late period of laying;appropriately enhance the immune capacity of laying hens;improve the serum biochemical indicators;increase the activity of digestive enzymes in the small intestine;and promote the release of gonadal hormone and the mRNA expression of FSHR gene in the ovary.展开更多
文摘水是限制和维系生物活动的主要因子,水文连通性与诸多生态过程联系紧密。作为表征水循环过程中物质、能量和生物体在景观单元之间传输的过程,水文连通性建立了地表水循环过程中景观单元物质与能量流之间的相互联系。运用文献计量方法,以Web of Science数据库及CNKI数据库为数据源,检索国内外水文连通性相关研究文献,运用Bibexcel、Ucient和Citespace等软件分别得到高频词、关键词共现网络可视图,在此基础上梳理国内外水文连通性研究进展。研究结果表明:围绕水文连通性,国内外发文量均呈现上升趋势,自1990年以来,国外水文连通度方面的研究与国内相比起步较早,且增长幅度较大;从关键词频上看,国外多偏重于不同类型生态系统结构功能变化对水文连通性的研究,国内则多偏重于河湖生态系统水系连通演变的研究;爆发词词频分析显示水文连通性与气候变化、生物多样性以及生态系统服务一度成为该领域研究热点;根据共现网络可视图,梳理国内外研究方向,水文连通性与生态过程、不同类型生态系统水文连通性对物质传输的影响,生态系统结构和功能的变化对水文连通性的影响等方面是当前的研究热点。开展不同尺度水文连通性制图,地下水依赖型生态系统水文连通性表征,基于地理信息技术与长期野外监测资料开展多尺度水文连通性定量评估和模型模拟是未来水文连通性研究的趋势。
文摘[Objective]The paper was to investigate the mechanism of Bacillus coagulans preparation in improving production performance of laying hens in late period of laying.[Method]A total of 648 individuals of"Jingfen 1"laying hens(66 weeks of age)in late period of laying were randomly divided into four groups,six replicates each group,and each group had 27 individuals of laying hens.The laying hens in control group were fed with basal diet,and those in experimental groupsⅠ,Ⅱ and Ⅲ were fed with the basal diets added with 3.33×10^6,1×10^7,3.33×10^7 CFU/g B.coagulans,respectively.The pretrial lasted one week,and the formal test lasted eight weeks.[Result]Compared with the control group,the laying rate in group Ⅰ increased significantly,and the feed-gain ratio in experimental group Ⅱ decreased noticeably while the spleen index increased remarkably;the alkaline phosphatase activities and blood calcium content in experimental groups Ⅰ,Ⅱ and Ⅲ increased significantly(P<0.05),while the triglyceride content decreased remarkably(P<0.05);the urea content in experimental groups Ⅰ and Ⅱ decreased obviously(P<0.05).Adding B.coagulans significantly increased the specific activity of amylase,lipase and protease in various intestinal mucosa of small intestine(P<0.05);adding B.coagulans significantly increased the content of follicle-stimulating hormone(FSH)and estradiol(E2),and significantly increased the mRNA expression of follicle stimulating hormone receptor gene(FSHR).[Conclusion]B.coagulans preparation could significantly improve the production performance of laying hens in late period of laying;appropriately enhance the immune capacity of laying hens;improve the serum biochemical indicators;increase the activity of digestive enzymes in the small intestine;and promote the release of gonadal hormone and the mRNA expression of FSHR gene in the ovary.