“土壤水库”知多少

来源 :科技信息 | 被引量 : 0次 | 上传用户:loupee
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
人们概念中的水库,应是储存水、供农田灌溉和人民生活使用。“土壤水库”近年来在报纸和一些科技书籍上经常看到和提到。土壤中的水常常不能满足作物的需要而呈现干旱,使作物减产,土壤水库在哪里呢? 首先,从地表面向下的土层,1米和2米深植物根分布的土层中,
其他文献
The developments of medicine always follow innovations in science and technology.In the past decade,such innovations have made cancer-related targeted therapies
The growing demand for new therapeutic strategies in the medical and pharmaceutic fields has resulted in a pressing need for novel druggable targets.Paradoxical
Metastasis is a multistep process involving modification of morphology to suit migration, reduction of tumor cell adhesion to the extracellular matrix, increase
Gemcitabine has high activity against nasopharyngeal carcinoma(NPC).The level of ribonucleotide reductase subunit M1(RRM1) expression is closely related to the
世界许多国家都很重视氢能源的研究,欧洲、日本、加拿大都把这项技术开发列为国家项目并且不断取得新成果。 石油和煤等矿物燃料是当前世界的主要能源,然而这些燃料总有枯竭
The practice of outpatient breast cancer surgery has been controversial in the United States. This study aimed to update time trends and geographic variation in
通过应用光合细菌,可将麦秆、玉米秆、花生壳、稻草等农作物秸秆制成高效鱼类生物饲料。该饲料综
Spatial analytical techniques and models are often used in epidemiology to identify spatial anomalies (hotspots) in disease regions. These analytical approaches
背景与目的:结肠癌是最常见的恶性肿瘤之一,其发病机制仍未完全明了。目前认为DNA甲基化导致转录抑制是恶性肿瘤发生的重要机制之一。E-cadherin能抑制肿瘤的浸润和转移,被公