土壤是怎么生成的

<正>土壤并非生来就具有肥力特征、能够生长绿色植物。跟生物发育一样,土壤发育也有一系列的过程。其中,母质、气候、生物、地形、时间是土壤形成的五大关键因素。土壤的发生起始于母岩的风化过程,坚硬的裸露母岩在日积月累的风化作用下形成成土母质。接下来,这些成土母质在微生物和低等植物的作用下逐渐演变为原始的土壤,然后再经过草本植物和木本植物的熟化,最终产生肥力,形成成熟土壤,     

地质工作要为农业发展服好务

(一) 地质工作为农业服务的内容很广,笔者认为可概括为五个方面。 1.进行土壤和农业地质背景研究。土壤是农作物生长的“基地”,是各种成土因素(如母岩、生物、气候、地形、时间和人类活动等)综合作用的产物。它的基本特性是其肥力。地质作用对土壤的形成和变化有着决定性影响。地表岩石是形成土壤的物质基础(即所谓成土“母质”),它在很大     

北京地区表层土壤磁化率分布特征

选定北京市昌平区十三陵水库库区和石景山区永定河两岸作为重点研究区，测量其表层土壤剖面的磁化率曲线．结果表明，不同地区的土壤剖面磁化率曲线存在着很大的差异，这与土壤的成土母质、成土作用和周围环境状况有着密切的关系．     

安徽省水稻土有效硅含量分布及影响因素

成土母质是影响土壤有效硅水平的主要因素,不同母质发育的水稻土有效硅平均含量顺序为：黄土性古河湖相沉积物＞近代黄泛＞淮河冲积＞石灰岩＞湖积物＞下蜀黄土＞长江冲积＞紫色砂页岩和第四纪红土＞板页岩和酸性结晶岩。土壤pH值和土壤有机质含量与土壤有效硅呈极显著正相关。安徽省水稻土有效硅含量不同地区差异很大,淮北平原＞江淮丘陵岗地＞沿江平原＞皖西山地＞皖南丘陵山地．     

北京地区表层土壤磁化率分布特征

选定北京市昌平区十三陵水库库区和石景山区永定河两岸作为重点研究区,测量其表层土壤剖面的磁化率曲线.结果表明,不同地区的土壤剖面磁化率曲线存在着很大的差异,这与土壤的成土母质、成土作用和周围环境状况有着密切的关系.     

安徽省土壤磷素形态及其影响因素研究

对安徽省不同性质土壤中的无机磷和有机磷进行了分析 ,结果表明 :土壤磷的含量与形态与成土母质、成土条件和耕作方式有很大关系。土壤无机磷以O P和Ca10 P为主 ,有机磷则以中活性及中稳态有机磷为主     

土壤地理学野外实习中土壤剖面的选择研究

土壤地理学野外实习是地理科学专业本科教学的实践验证过程,属于实践教学中不可缺少的重要组成部分.针对吉林师范大学旅游与地理科学学院地理科学专业本科生的实际情况,分析了土壤地理学野外实习中土壤剖面的选择,并且根据四平地区的主要土壤类型,研究了代表性土壤黑土、白浆土、黑钙土和灰棕壤的土壤剖面构型,以及生物、气候、母质等因素在土壤形成中的作用.     

池州地区石灰岩分布茶园土壤的形成

本文对池州地区石灰岩分布区茶园土壤的形成进行了探讨。指出本区茶园土壤受石灰岩母质影响小,土壤受气候因素,生物因素影响较明显,属地带性土壤。     

专题四 陆地和海洋 第三讲 生物、土壤和自然带

【常考考点】生物在陆地环境形成过程中的作用,土壤的形成及其在陆地环境中的作用,地理环境的整体性和地域分异规律【知识梳理】环境影响生物分布原因——生物与环境进行物质和能量交换影响因素:气候——光照、热量、水分对农业生产影响:因地制宜,立体农业、种植制度生物与环境     

基本成土过程划分的原则和具体准则

本文针对目前在基本成土这程的划分上,尚不统一的情况,为探求统一途经,提出了基本成土过程划分的原则和具体准则:原则是在划分基本成土过程的时候,必须考虑其与发生条件、所发生的土壤物质及其变化特征的相关性。并称之为发生-诊断学原则。具体准则是土壤性,基本性,诊断性状与诊断层。并以“富铝化过程”这一基本成土过程为例,对它们进行了具体讨论。     

Preschool and primary school influences on the development of children's early numeracy skills between the ages of 3 and 7 years in Germany

Few studies have investigated how preschool and primary school interact to influence children's cognitive development. The present investigation explores German children's numeracy skills between age 3 (1st year of preschool) and age 7 (1st year of primary school). We first identified the influence of preschool experience on development while controlling for child factors, family background, and the quality of the home learning environment (HLE). We then considered how the instructional quality of primary schools influences numeracy. We finally analysed how preschool and primary school interact. We sampled 547 children who attended 97 German preschools. Latent growth curve analyses identified child and family factors related to age 3 numeracy and development to age 7: gender, migration background, socioeconomic status (SES), mother education, HLE. The effects of preschool on numeracy development persist until age 7 with notable effects from process quality. Strengthened efforts are needed to ensure high quality preschool education in Germany.     

青藏高原城市化的制约因素与发展趋势分析

本文从自然环境、经济发展水平、社会发育程度、城镇基础设施、城市结构和人口规模等方面,对青藏高原城市化进程中所面临的制约因素进行系统分析,并从产业素质、城镇结构、基础设施、户籍制度等方面,剖析了青藏高原城市化发展的总体趋势。     

浅析高职院校韩语教学的创新

随着经济全球化的发展,学习韩语的人群也越来越多,这就促使很多高职院校成立了与韩语教学有关的专业。但是,除母语之外的任何一种语种的学习都会遇到很多的问题,这也是当前学生在学习韩语过程中感觉难度大的原因之一。为了能够进一步了解高职院校韩语教学情况,本文从当前高职院校韩语教学现状出发,找到影响高职院校韩语教学质量的因素,并提出几点关于高职院校韩语教学的创新策略,为改革高职院校韩语教学过程提供理论指导。     

黄土高原水土流失的现状与思考

黄土高原的水土流失是脆弱的生态系统与不合理的人类活动共同作用的结果,水土保持是该地区生态恢复和重建的基础。文章分析了黄土高原地区水土流失的基本现状,探讨水土流失的影响因素,提出黄土高原地区水土保持的建议:提倡节水型水土保持模式,鼓励发展“混林农业”,防范基础设施建设过程中的水土流失。     

大学生诚信品质的形成规律及路径探索

大学生诚信品质的形成包括内在转化过程和外在影响过程,经过诚信情感、诚信信念和诚信意志三个心理过程,最终在外在因素的影响下,以具体的诚信行为表现出来。诚信品质形成规律主要有渐进律、矛盾律和内化外化律。诚信教育应该遵循渐进律,把诚信教育的内容与学生的思想行为需求结合起来;遵循矛盾律,引导学生通过实践把诚信认知和诚信行为统一起来;遵循内化外化律,引导学生把加强自律与遵守他律结合起来。     

注塑件熔接痕的形成及控制

介绍了注塑件熔接痕的形成机理,分析了熔接痕的影响因素及其控制措施,并借助Moldflow软件模拟注塑件熔接痕的形成,通过浇口及工艺参数的优化,避免或减少熔接痕对制品质量的影响。     

关于改善带状组团城市交通问题的研究——以福清市中心城区为例

随着经济的发展,城市生活品质的提高,人们对交通出行方式及出行质量的要求越来越高。带状组团城市的发展受自然地形与城市土地利用的影响较大,其在发展过程中易出现道路拥堵、机非人混行等问题,尤其在老城区易形成交通瓶颈。以福清市中心城区为例,研究其土地利用、空间布局及交通系统的特点,提出加强规划引导、优化规划路网结构、选择相适应的交通模式等思路,以改善带状组团城市存在的交通问题。     

Home and preschool learning environments and their relations to the development of early numeracy skills

This study examined the influence of the quality of home and preschool learning environments on the development of early numeracy skills in Germany, drawing on a sample of 532 children in 97 preschools. Latent growth curve models were used to investigate early numeracy skills and their development from the first (average age: 3 years) to the third year (average age: 5 years) of preschool. Several child and family background factors (e.g., gender, maternal education, socioeconomic status), measures of the home learning environment (e.g., literacy- and numeracy-related activities), and measures of preschool structural and process quality (e.g., ECERS-E, ECERS-R) were tested as predictors of numeracy skills and their development. The analyses identified child and family background factors that predicted numeracy skills in the first year of preschool and their development over the three points of measurement—particularly gender, parental native language status (German/other), socioeconomic status, and mother's educational level. The quality of the home learning environment was strongly associated with numeracy skills in the first year of preschool, and this advantage was maintained at later ages. In contrast, the process quality of the preschool was not related to numeracy skills at the first measurement, but was significantly related to development over the period observed. The results underline the differential impact of the two learning environments on the development of numeracy skills. Interaction effects are explored and discussed.     

Child care in the preschool years: Attachment,behaviour problems and cognitive development

The possible implications of the experience of non parental care on cognitive development and on behaviour problems are considered in interaction with individual and contextual variables. A sample of 47 Swiss children who experienced varying kinds of care arrangements were studied longitudinally between 1 and 5 years of age. The effects of the experience of care were related to mothers’ reports of behavioral problems (CBCL, with subscales of internalizing and of externalizing problems) at age 5, and to cognitive developmental quotients (at 1, 2 and 5 years). Several variables were considered for their potential interaction with the experience of care, such as the pattern of attachment to the mother (observed at 21 months of age in the “Strange Situation”), characteristics of the experience of care (duration and type of care), its quality (relationship with non parental caregivers), the socio-economic status of the family, etc. The effect of non parental care on behaviour problems (5 years) happened to be mediated by the the pattern of attachment to the mother: insecurely attached children had some risk to be reported as having externalizing problems, but this didn’t occur when they had an extended experience of non parental care, and when non parental care was mainly family-based. The effect of non parental care on cognitive development was mediated by the quality of care: children with a positive contact with the caregivers had greater cognitive gains between 2 and 5 years; the relationship with the care-givers itself was influenced by the quality of the relationship with the mother. The limited size and origin of the sample restricts generalization, however these data might contribute to the notion that non parental care can have varying effects depending of the type of care, the quality of the relation with the caregivers, the age and personal traits of the child.     

基于logistic模型的新疆高职学生思想政治态度研究

对新疆五所高职院校学生思想政治状况调查表中涉及国家观、民族观、宗教观的有关问题,建立民族、态度与家庭背景的logistic模型,根据优势比率给出了不同问题的态度和影响态度的因素。