全文获取类型
收费全文 | 125篇 |
免费 | 18篇 |
国内免费 | 4篇 |
专业分类
测绘学 | 1篇 |
大气科学 | 11篇 |
地球物理 | 70篇 |
地质学 | 48篇 |
海洋学 | 8篇 |
天文学 | 1篇 |
综合类 | 5篇 |
自然地理 | 3篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 7篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 2篇 |
2011年 | 16篇 |
2010年 | 13篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 4篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 2篇 |
2003年 | 6篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有147条查询结果,搜索用时 296 毫秒
101.
Three juvenile Brazilian sharpnose sharks (Rhizoprionodon lalandii) caught in gillnets in southeast Brazil, southwest Atlantic, were found with plastic debris rings around their gill or mouth region. The rings caused severe abrasion on the sharks' tissues as the animal grew, the collars probably hampering normal feeding and/or ventilation since two of the collared individuals were emaciated. The rings were identified as detachable lid parts from plastic bottles, likely thrown overboard by fishery and/or recreation boats. As several carcharhinid shark species dwells and reproduce in shallow waters, the impact of discarded plastic debris likely is greater on this shark type. 相似文献
102.
对成都市蔬菜生产春淡的气候原因及塑料大棚内小气候特征进行分析,选取六种补淡蔬菜,利用平行比较法和模糊聚类法,讨论了棚内栽培季节,为缓解成都蔬菜生产春淡的可行性作科学论证提供了依据。 相似文献
103.
根据地震的涡旋状分布图象和大型盆地的分布特征,指出中东亚地区存在着巨型的涡旋构造。该涡旋构造由主环(直径约2000km)及内、外分支构成,主环和内环绕四川盆地逆时针旋转,外分支环绕塔里木等大型盆地顺时针旋转。根据层析成像资料推测,上述涡旋构造是上升型地幔涡旋对岩石圈板块底界驱动作用的结果。综合地幔涡旋和岩石圈下层塑性流动网络的见解,提出了“涡旋/网络”大陆动力学模型。该模型认为来自地幔涡旋的板块底界驱动力和由岩石圈塑性流动网络传递的板块边缘驱动力,作为两种基本的驱动力源,控制着中东亚大陆的构造变形及地震活动 相似文献
104.
105.
Clay mineral composition and geotechnical index properties of marine clays collected from Singapore, Korea, and Japan were investigated, and the correlation of clay mineral composition with the consistency limits and activity of the clays was examined. Predominant clay minerals were kaolinite for Singapore clay, kaolinite, vermiculite, and illite for Pusan clay, and smectite for Hachirogata and Ariake clay from Japan. The activity of clay indicates that Singapore clay is classified as normal or inactive, Pusan clay as normal, and Hachirogata and Ariake clays mostly as active. Significant positive correlations were found between smectite percentage in bulk soil and the liquid and plastic limits of the clays. 相似文献
106.
塑料大棚商品苗的出棚时间为4月28日,较以前的露天虾池保苗提早1.5月;出棚商品苗壳高为4.1±2.0mm,是同期海区苗壳高的2倍,保苗率为29.7%,与同期海区保苗相比提高1倍以上。 相似文献
107.
一种被众多学者承认的论点是:孕震结构是彼此间即相互牵连又有共同成因的断裂构成的。我们知道,前震的地震活动征兆明显增加表明破裂的速率应遵从一种幂律关系。幂律关系的物理内涵是──大破裂是众多小破裂(看作众多子系统)之间的一种相互作用的结果(又称多体互作用)。深入讨论这种互作用是本文的核心。 相似文献
108.
Per capita consumption of plastic continues to increase and remains at high levels in high-income countries, despite obvious contributions to the global problem of plastics pollution. This paper attempts to provide an explanation for this phenomenon based on construal level theory, positing that plastic waste is a problem that is perceived as “out of sight and out of mind” for consumers in high plastic consumption (typically high income) countries and that this is influenced by the export of plastic waste to other (typically lower income and lower consumption) countries for disposal – shifting the burden of mismanaged plastic waste and perceptions of plastics pollution in the countries creating the majority of plastic waste. The apparent lack of plastics pollution in a local environment becomes a mediator, influenced by the export of plastic waste, which may then contribute to further plastics consumption. The theory is tested using structural equation modelling using rare, available matched data for mismanaged plastic waste, plastic waste exports, and plastics consumption at an aggregate country level. All study hypotheses are supported. The paper concludes with recommendations for future research and practice, including potential changes to government policy aimed at reducing future plastics consumption and pollution. 相似文献
109.
在高温高压及慢应变率下使磁铁矿岩样品发生了流变。对此过程前后的磁性测试表明,产生了与流变过程相关的磁化率各向异性。进一步研究说明,这种“流变磁效应”,主要是由于岩样内磁性矿物颗粒在流变过程中,由大致等粒形且方向性不明显而转变为扁椭球形且具有了一定优选方位而造成的。地震孕育是在高温、高压及缓慢的时间过程中进行的,因此研究流变带来的物性变化对于地震前兆的认识至关重要。本实验结果从一个新的角度探索地震磁效应,具有理论和实际意义。 相似文献
110.