全文获取类型
收费全文 | 60篇 |
免费 | 10篇 |
国内免费 | 7篇 |
专业分类
大气科学 | 12篇 |
地球物理 | 6篇 |
地质学 | 54篇 |
海洋学 | 3篇 |
自然地理 | 2篇 |
出版年
2014年 | 2篇 |
2013年 | 1篇 |
2010年 | 2篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 11篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有77条查询结果,搜索用时 15 毫秒
71.
大型开挖对环境的影响研究 总被引:4,自引:0,他引:4
徐嘉谟 《地质灾害与环境保护》1997,8(1):35-49
岩土体开挖对环境的影响问题,实质上是开挖引起岩土体移动,变形,破坏和失稳的问题,主要从对环境影响的意义上,阐述了有代表性的两种大型开挖-露天开挖和地下开挖引起岩土体移动,变形和破坏后一些规律性问题,并从机理上对某些现象的规律性作了解释。 相似文献
72.
73.
Characteristics of organic and elemental carbon in PM2.5 samples in Shanghai, China 总被引:11,自引:0,他引:11
Yanli Feng Yingjun Chen Hui Guo Guorui Zhi Shengchun Xiong Jun Li Guoying Sheng Jiamo Fu 《Atmospheric Research》2009,92(4):434-442
Shanghai is the largest industrial and commercial city in China, and its air quality has been deteriorating for several decades. However, there are scarce researches on the level and seasonal variation of fine particle (PM2.5) as well as the carbonaceous fractions when compared with other cities in China and around the world. In the present paper, abundance and seasonal characteristics of PM2.5, organic carbon (OC) and elemental carbon (EC) were studied at urban and suburban sites in Shanghai during four season-representative months in 2005–2006 year. PM2.5 samples were collected with high-vol samplers and analyzed for OC and EC using thermal-optical transmittance (TOT) protocol. Results showed that the annual average PM2.5 concentrations were 90.3–95.5 μg/m3 at both sites, while OC and EC were 14.7–17.4 μg/m3 and 2.8–3.0 μg/m3, respectively, with the OC/EC ratios of 5.0–5.6. The carbonaceous levels ranked by the order of Beijing > Guangzhou > Shanghai > Hong Kong. The carbonaceous aerosol accounted for 30% of the PM2.5 mass. On seasonal average, the highest OC and EC levels occurred during fall, and they were higher than the values in summer by a factor of 2. Strong correlations (r = 0.79–0.93) between OC and EC were found in the four seasons. Average level of secondary organic carbon (SOC) was 5.7–7.2 μg/m3, accounting for 30% of the total OC. Strong seasonal variation was observed for SOC with the highest value during fall, which was about two times the annual average. 相似文献
74.
内蒙古湖洞察汗淖(碱)湖沉积物中的生物标志物特征及其古环境意义 总被引:7,自引:1,他引:7
湖洞察汗淖湖是一个高盐度碱性湖泊其沉积物中存在一个特殊的生物标志物组合,以长链不饱和脂肪酮和乙基甾醚同时存在为特征。该湖沉积物的有机质具有来源于陆生高等植物和水生生物的双源性,且以陆生高等植物为来源为主。 相似文献
75.
Lincang superlarge germanium deposit in Yunnan Province,China: Sedimentation,diagenesis,hydrothermal process and mineralization 总被引:2,自引:0,他引:2
Zhuang Hanping Lu Jialan Fu Jiamo Liu Jinzhong Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 《中国地质大学学报(英文版)》1998,9(2)
Gemineralizationincoalsassociatescloselywithcoalifi-cation.Manykindsofmineralizinginformationcanberecord-edbythestructure,tex... 相似文献
76.
热泉热液金矿化中嗜热微生物——有机质的地球化学作用 总被引:3,自引:0,他引:3
本文主要通过对热泉热液金成矿过程中的热泉水化学成分和组分的分析,得出泉水中金与氮磷硫、氟硅碳两组组分有很好的相关性。嗜热硫酸盐还原菌能使[Au(HS)2]-和[Au(S2O3)2]3-都氧化还原成硫化物,从而使金由热水溶液中沉淀。热泉沉积软泥的有机质中的含硫氨基酸、含硫芳烃也起到了一定的聚金作用。 相似文献
77.
Yonglin Liu Xinhui Bi L. Y. Chan Sheng Wen Xinming Wang Guoying Sheng Jiamo Fu 《Journal of Atmospheric Chemistry》2013,70(1):53-67
Formaldehyde (HCHO), acetaldehyde (CH3CHO) and acetone (CH3COCH3) were measured at Wanqingsha (WQS) in south China during November-December 2008–2010. Carbonyl compound pollution characteristics under the influence of the financial crisis (FC) were studied. Atmospheric carbonyl compound concentrations in the 2008 and 2009 sampling periods were affected by the 2008 FC. The industrial downturn plus the high closing down number of the small enterprises with limited emission treatment during the FC played an important role in the reduction of the industry-related CH3CHO and CH3COCH3. In 2010, the recovery of industrial activities occurred, but affected by traffic restriction enforcement in Guangzhou over the Asian Games period, HCHO concentration (daytime 7.59?±?2.59 μg m?3) was lower than expectation. Carbonyl compounds in WQS site were highly influenced by regional pollution transport from different upwind urban cities and industrial districts in the north-northwest to northeast wind sector in winter. Also, the interaction of the winter monsoon with the warm ocean along the coastline as well as day and night boundary layer mixing height variation affected carbonyl compound concentrations in WQS. The daytime mean dry deposition losses of HCHO and CH3CHO were first time model-estimated for 2009 and 2010. For loss of HCHO in the early afternoon, photolysis was the dominant sink, followed by dry deposition and removal by OH radical (?OH), while for CH3CHO, dry deposition was dominant. For the gain of HCHO and CH3CHO, the production rates during early afternoon in 2009 and 2010 were estimated by an indirect approach. 相似文献