全文获取类型
收费全文 | 62篇 |
免费 | 5篇 |
专业分类
大气科学 | 3篇 |
地球物理 | 11篇 |
地质学 | 37篇 |
海洋学 | 2篇 |
天文学 | 8篇 |
综合类 | 1篇 |
自然地理 | 5篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 5篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 5篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2003年 | 5篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有67条查询结果,搜索用时 203 毫秒
31.
The positron acoustic shock and solitary wave are explored in nonextensive electron-positron-ion plasma. The plasma system under-consideration, consists of a classical positron beam, q distributed electrons and positively charged bulky ions constitute a neutralizing background. The nonlinear Korteweg-de Vries and Burger equations are derived by employing the standard reductive perturbation method. The positron acoustic wave in linear limit is also discussed for dissipative as well as nondissipative cases of nonextensive plasmas. The plasma parameters such as, the concentration of neutralizing ions background, beam velocity, temperature and q parameter of the nonextensive electrons are noticed to significantly affect the positron acoustic shock and solitary waves. Our findings may be helpful in the understanding of laboratory beam plasma interaction experiments as well as the astrophysical nonextensive plasmas interacting with positron beam. 相似文献
32.
Development of a sustainable livelihood security model for storm-surge hazard in the coastal areas of Bangladesh 总被引:2,自引:1,他引:1
Mahmuda Mutahara Anisul Haque M. Shah Alam Khan Jeroen F. Warner Philippus Wester 《Stochastic Environmental Research and Risk Assessment (SERRA)》2016,30(5):1301-1315
Coastal communities in Bangladesh are at great risk due to frequent cyclones and cyclone induced storm-surges, which damages inland and marine resource systems. In the present research, seven marginal livelihood groups including Farmers, Fisherman, Fry (shrimp) collectors, Salt farmers, Dry fishers, Forest resource extractors, and Daily wage labourers are identified to be extremely affected by storm- surges in the coastal area of Bangladesh. A livelihood security model was developed to investigate the security status of the coastal livelihood system in a participatory approach. In the model, livelihood security consists of five components: (1) Food, (2) Income, (3) Life & health, (4) House & properties, and (5) Water security. Analytical hierarchy process was followed to assess the livelihood security indicators based on respondents’ security options. The model was verified through direct field observation and expert judgment. The Livelihood Security Model yields a Livelihood Security Index which can be used for assessing and comparing the household security level (in %) of different livelihood groups in the storm-surge prone coastal areas. The model was applied with data from two major coastal areas (Cox’s Bazar and Satkhira) of Bangladesh and is applicable to other coastal areas having similar settings. 相似文献
33.
M. Nozibul Haque Shamsuddin Shahid Mumnunul Keramat Morteza Mohsenipour 《Water Resources》2016,43(2):283-291
Geographical Information System (GIS) has been used in this paper to delineate groundwater resources potential in the western part of greater Kushtia district of Bangladesh, where urgent attention for augmentation of irrigation water supply is required. Thematic maps of transmissivity, hydraulic conductivity, specific yield, net recharge, aquifer thickness, surface water bodies, aquifer resistivity, overburden aquitard thickness and its resistivity have been prepared and assigned weight according to their relative importance using Analytical Hierarchical Process for the preparation of groundwater potential model. Since the values within each thematic map vary significantly, they are classified into various ranges or types and assigned ratings. Finally, the thematic maps are integrated using GIS to prepare the groundwater potential map for the study area in terms of Ground Water Potential Index (GWPI). The evolved map indicates that 22.51% of the study area have GWPI more than 0.70 and therefore, have excellent prospective for exploitation. About 69.12% of the area with GWPI ranging from 0.50 to 0.70 is also quite promising for groundwater abstraction, while the rest 8.37% area having GWPI below 0.50 indicates moderate potential. The obtained map of groundwater potential is found in good agreement with the yields of available pumping test data. 相似文献
34.
Natural Hazards - The Canadian Province of Manitoba has experienced many severe floods and other natural disasters, and in response municipal, provincial, and federal governments have developed... 相似文献
35.
The purpose of this research was to identify social, culturaland psychological aspects of riverbank erosion-induced displacement in the flood plainsof Bangladesh. Although considerable research has examined the social and economicimpacts of riverine hazards in Bangladesh, there has been a general neglect of associatedpsychosocial implications. The specific objectives of the study were to: (1) assess hazardawareness in relation to riverbank erosion, (2) determine the magnitude of psychologicaldistress associated with displacement, and (3) identify patterns of psychosocial copingand adaptation common to displaced persons in Bangladesh. Although displacees were foundto have a significantly higher level of distress than non-displacees, this was relatedprimarily to socioeconomic deprivation rather than to displacement per se. The findingsof this study showed that the constant threat of riverbank erosion has contributed to asubstantial disaster subculture in the riverine zones of Bangladesh. The commonly hypothesized factorssuch as loss of land and frequency and duration of displacement were notsignificantly associated with distress levels.The need to integrate into hazard analysis and mitigation studiesa social, cultural and psychological context is recommended. In Bangladesh, the poor copewith hardship and problems by relying on religion, which in turn significantlyinfluences how they perceive and interpret natural calamities. It is argued that the capacityof people to respond to environmental threats is a function of not only the physicalforces which affect them, but of indigenous social and cultural belief systems which influencehow people interpret and organize their activities. Hazard analysis and mitigation wouldbe most effective when it takes into account psychological and socio-cultural aspects ofdisasters, due to the fact that psychological distress impacts the capacity of people toachieve livelihoods, but also important social and psychological processes determine the waypeople perceive and adapt to natural hazards. 相似文献
36.
Study of surface runoff using physical models 总被引:1,自引:0,他引:1
M. Amin Haque 《Environmental Geology》2002,41(7):797-805
37.
Climatic changes,desertification and the Republic of Sudan 总被引:1,自引:0,他引:1
Shamsul Haque Alvi 《GeoJournal》1994,33(4):393-399
Meteorological data for a period of 30 to 50 years was analysed to ascertain the climatic changes in the Republic of Sudan. The study confirms that the temperatures are rising and rainfall declining. Rigorous analysis of relative humidity, clouds, rediation and evaporation also confirms the changing pattern, a trend which may accelerate environmental degradation and desertification in Sudan.The author acknowledges the assistance of Nadir Ahmad El-Agib in completing this study. He is also thankful to Dr. Ahmad El-Agib for his help in getting the Meteorological data from Sudan. 相似文献
38.
39.
Xu Jiang Dai Guoliang Gong Weiming Zhang Qi Haque Asadul Gamage Ranjith Pathegama 《Acta Geotechnica》2021,16(3):653-677
Acta Geotechnica - Shaft resistance generally dominates at the service loads of rock-socketed piles and therefore is always a topic of large research interest. This paper reviews the research... 相似文献
40.
Sanzidur Rahman Mohammad Mizanul Haque Kazal 《Singapore journal of tropical geography》2015,36(1):83-97
The paper measures the level of crop diversity and identifies factors influencing diversification using a panel data of 17 regions of Bangladesh covering a 19 year period (1990–2008). Results revealed the trends that agricultural areas allocated to high‐yielding variety rice, spices and vegetables has increased, while areas cultivating traditional rice, minor cereals, oilseeds, pulses, jute and sugarcane has declined at variable rates across regions with significant differences. The level of crop diversity is also significantly different across regions and has decreased in 2008 from its 1990 level in most regions except Faridpur, Khulna and Sylhet. Among the determinants, an increase in the relative prices of vegetables and urea fertilizer, extension expenditure, labour stock per farm, average farm size, irrigation and a reduction in livestock per farm significantly increase crop diversity. Price policies to improve vegetable prices and investment in irrigation infrastructure and extension services are suggested to promote crop diversity in Bangladesh. 相似文献