共查询到20条相似文献，搜索用时 203 毫秒
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2001年9月3～24日，当黄河龙门站流量仅为368～1130m^3/s，多为800m^3/s以下时，黄河主流在合阳榆林护村工程与榆林下延工程之间形成斜河，不断坐湾冲刷，使其间长500m(回淤口)的滩岸接连溃退270多m，榆林下延工程上坝路坍塌长达160余m，宽1～3m，出险原因一是流量较小， 相似文献
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以松花江一级支流蚂蚁河延寿水文站至莲花(二)站水文站60 km长的河段为研究区域,以国家Ⅱ级保护水生野生动物细鳞鱼为目标物种,绘制细鳞鱼产卵期水深、流速适宜性曲线,采用物理栖息地模型中的PHABSIM模型进行水力模拟,并绘制WUA-流量关系曲线.研究得出细鳞鱼4—5月产卵期所需最小生态流量为25 m3·s-1,最适宜生态流量为60 m3·s-1.建议需要优化配置蚂蚁河灌区取水口的取用水量和取水时间,在保障细鳞鱼正常生存产卵的前提下发展农业经济. 相似文献
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《赤峰学院学报(自然科学版)》2016,(16)
锚喷支护是软岩巷道掘支过程中常用的支护措施,但受围岩条件、施工环境等因素的影响,锚喷支护过程中混凝土会出现一定的回弹现象.本文以小官庄铁矿为工程背景,采用现场试验的方法,从干喷及湿喷工艺的对比、速凝剂流量、混合料流量、混凝土泵泵压及风压五个方面对锚喷支护中混凝土回弹影响因素进行了分析,最后结果表明,湿喷工艺相比干喷工艺可以降低混凝土的回弹率,且当速凝剂流量为0.1~0.13m3/h,混合料流量为5~5.8m3/h,泵压为3.8~4.5MPa,风压为0.4MPa时,回弹率较低,对软岩巷道锚喷支护混凝土回弹研究具有一定的借鉴意义. 相似文献
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蔡治华 《安徽科技学院学报》2007,21(4):8-9
1日龄AA肉鸡300只,随机分成Ⅰ、Ⅱ、Ⅲ三组,每组100只,Ⅰ组为对照组,Ⅱ、Ⅲ组为试验组,在7周的饲养期内,Ⅰ组的氨浓度为0mg/m3,Ⅱ、Ⅲ组的氨浓度分别为19.3mg/m3、38.6mg/m3.结果表明鸡舍中氨浓度为19.3mg/m3对肉鸡体重、屠体重和日增重无显著影响,氨浓度为38.6mg/m3时对肉鸡体重、屠体重和日增重有显著影响. 相似文献
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所谓质点系牛顿第二定律就是,如果这个质点系在任意方向上受的合外力为Fx,质点系中的n个物体(质量分别为m1,m2,m3……mn)在x方向上的加速度分别为a1x、a2x……anx,则有: Fx=m1a1x+m2a2x……+mnanx. 高中阶段很多题目,用隔离单个物体的方法解决问题相当繁琐。而质点系牛顿第二定律的应用,由于对系统的综合分析,避免了质点系间内力出现的复杂性,可简捷地解答 相似文献
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采用2000～2010年鹿角站～城陵矶(七里山)站水位落差与城陵矶(七里山)站实测含沙量资料分析,得出:洞庭湖出口水道含沙量与鹿角站～城陵矶站(七里山)水位落差有比较稳定的对应关系,当落差大于1m时一般会出现大于0.3kg/m3含沙量,含沙量大于0.3kg/m3时水位级在23～27m之间。该方案应用为捕捉沙峰过程,使城陵矶(七里山)站沙峰出现的预见期提前,减少了测次布置的盲目性,节约了生产成本,防止漏测年最大或次大含沙量过程。 相似文献
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安康防洪大堤修建运用已经18年,因江北河堤的建成以及其它各种人类活动的影响,原城堤是否还满足百年一遇设计洪水.经论证,江北河堤的修建,减小了河道过水断面面积5%,致使同级流量下的相应水位抬高0.1～0.22m,但对256.8m的堤顶高程来讲,仍能保证30500m3/s流量的泄洪能力.其它人类活动对河道有一定影响,须加强观测,进行分析、论证以便采取相应措施,确保大堤安全. 相似文献
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转型中国既保留着传统的深刻痕迹同时又感受着现代经济的强烈冲击,乡土社会也自不例外,探索转型中的中国乡土社会法律纠纷解决机制成为此次＂武汉大学法学院赴红安暑期实践＂的社会调查主题。我们选定了湖北红安县对天河村和黄家岗村作为实践考察的目的地,通过发放调查问卷、访谈等形式获取相关信息,并通过实证分析发现了调解作为传统与时代结合的救济方式在农村法律生活中起到核心作用。本文对农村法律纠纷解决机制中的调解制度为切入点进行探讨,通过纵向思考、横向比较,讨论农村救济机制的选择与未来。 相似文献
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Christina Wikström 《Assessment in Education: Principles, Policy & Practice》2006,13(1):113-128
Education and assessment in Swedish schools have been affected by several reforms during the last two decades. The educational system has moved from centralization to decentralization and a goal‐oriented approach has been introduced on all educational levels. This paper provides an historical overview of the Swedish educational system, educational and assessment policies and principles, to explain why and how the reforms have been carried out. This is followed by a discussion on the effects and consequences of recent reforms, based on findings in recent education and assessment research. 相似文献
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公元前十四世纪,商朝国王盘庚把都城从奄迁到了殷,此后历时二百七十三年,商朝再也没有迁都.对于盘庚迁都的原因,历来说法不一.其实,社会动乱和河患引起的生态环境的恶化,才是盘庚迁殷的主要原因.盘庚迁殷以后,注重治理和保护环境,为后来商王朝的可持续发展奠定了基础,也为今天处理经济发展和保护生态环境之间的关系提供了宝贵的经验. 相似文献
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刘静 《杨凌职业技术学院学报》2011,10(4):61-63
2010年7月23日千阳水文站发生建站以来2 130m3/s的最大洪水,造成经济损失4.95亿元。本文就非常时期抢测洪峰流量时借用水道断面面积的问题,通过对＂7.23＂洪水流量测验断面面积借用问题的分析,并结合本次洪水过程流量测验断面面积与历年观测资料进行了对比,提出了对于抢测洪峰时如何处理测流断面面积借用问题的新思路、新方法,不能再以传统的＂峰前借峰前,峰后借峰后＂作为借用依据,对以后水文测验流量断面面积借用具有一定的借鉴作用。 相似文献
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国立东北中山中学作为中国第一所国立中学,成立于1934年,开创抗战时期国立中学的先河。它广泛收容流亡关内的东北学生和教师,几易校址,由北平而南京,继而转汉口至湘乡,最后辗转经桂林到达四川自流井,完成长途迁徙,直到抗战胜利后复员沈阳,复至在北平停办。文章旨在考察国立东北中山中学的创立和在战火中的发展历程,并对其功绩做出客观评价。 相似文献
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《师资教育杂志》2012,38(5):447-460
New Zealand teacher education has been profoundly affected by major social and economic changes since 1974. From a separate sector controlled by the Department of Education, it has moved through deregulation to largely university provision with research imperatives for staff. Programme scope has broadened to embrace early childhood and the continuing education of teachers. Current concerns are the impact of performativity, funding challenges and external compliance. New directions have often been a response to issues of supply or political ideology rather than considered policy. The way forward is uncertain. 相似文献
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剡自勉 《伊犁师范学院学报》2014,(1):47-51
翻检花儿学术成果中涉及“新疆花儿”的内容,可知“新疆花儿”古已有之,其起源理当不比内地花儿晚。“新疆花儿”一度影响内地花儿,其“花儿”因子潜藏在新疆各族人民群众的音乐文化之中,这就是明清以来回族同胞迁入新疆一唱花儿而众和之的原因。新疆不是花儿飞区．新疆是花儿的故乡。 相似文献
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Patricia Melgar Rosa Larena Laura Ruiz Stephanie Rammel 《European Journal of Education》2011,46(2):219-227
In its growth strategy for the coming decade, the EU recognises the Roma as one of several groups especially affected by poverty and social vulnerability. So far, many efforts to reverse this social exclusion have failed; imposed solutions based on power relations have ignored Roma voices and suggestions from the community. As a result, the EU now emphasises the urgency of identifying measures that can effectively help their situation. This article draws on data from a qualitative longitudinal case study of predominantly Roma schools in Spain. It shows how the move from power-based relations with Roma families to more dialogic ones has helped overcome both social and educational exclusion. Two dimensions are identified that facilitate this transition: demonopolisation of the expert knowledge and recognition of the Roma culture. By introducing dialogic relations, these schools have encouraged more Roma women to participate in different domains; they have also increased their academic expectations, moved beyond society's prejudice towards the Roma, and helped new role models to emerge. 相似文献
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1 Ｉｎｔｒｏｄｕｃｔｉｏｎ ＡＢ5 ｔｙｐｅｈｙｄｒｏｇｅｎｓｔｏｒａｇｅａｌｌｏｙｓｈａｖｅｂｅｅｎｉｎｔｅｎ ｓｉｖｅｌｙｉｎｖｅｓｔｉｇａｔｅｄｓｉｎｃｅｔｈｅｆｉｒｓｔｕｓｅａｓａｎｅｌｅｃｔｒｏｄｅｒｅｐｏｒｔｅｄｂｙＪｕｓｔｉｉｎ 1973[1] .ＴｈｅｃｏｍｍｅｒｃｉａｌＡＢ5ｅｌｅｃｔｒｏｄｅｓｕｓｅｍｉｓｃｈｍｅｔａｌ,ａｌｏｗｃｏｓｔｍｉｘｔｕｒｅｏｆｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓ ,ａｓａｓｕｂｓｔｉｔｕｔｅｆｏｒＬａ ,ｗｈｉｌｅｔｈｅＢ5ｃｏｍｐｏｎｅｎｔｒｅｍａｉｎｓｐｒｉｍａｒ… 相似文献
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David Reynolds 《International journal of qualitative studies in education》2013,26(2):143-154
Abstract This article recounts the development of a relationship between a university researcher and a public school practitioner, and describes how changes in this relationship affected the research process itself. The article addresses three issues central to qualitative studies in education: the attempt to have research benefit practice; the formation of reciprocal relationships between researchers and those researched; and the writing of ethnographic accounts. The story is told in separate voices, alternating between the person researched and the researcher. Each voice describes how the relationship moved through six distinct, yet related, phases. Beginning with caution and skepticism, moving toward trust and self‐disclosure, each of these phases affected the conduct of the research study and its findings. 相似文献