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111.
WenJun Zhang 《Environment, Development and Sustainability》2008,10(6):717-730
The continuous growth of world population and the intensification of urbanization process create a challenge to environment
quality and sustainable development around the world. In this paper I tried to conduct a forecast analysis of near-future
urbanization related population growth worldwide, based on recent demographic trends. Such an analysis can provide important
insights into the prospects for changes in the size and composition of world population and in urbanization process. Optimal
polynomial functions were used to fit historical trajectories of population dynamics, and the detailed forecasts of the population
mainly over the period 2010–2030 were conducted and analyzed.
If the past pattern continues, world total population would increase to 7.94–8.33 billion in 2030 and the annual growth is
expected to continually decline in the forecast period. Global total population would stop increasing during the period 2050–2060
and would not exceed 9.5 billion in the future. The total population of Africa, Asia, Oceania, South America, North & Central
America would separately increase to 1.35–1.41, 4.86–5.65, 0.04–0.05, 0.44–0.45, and 0.71–0.72 billion in 2030. Europe’s total
population is forecast to decline to 0.64–0.67 billion in 2030.
World’s rural population is expected to grow to the maximum during the period 2015–2020 and would greatly decline after that
period. Global rural population would reach 3.12–3.41 billion in 2030. Rural population in Asia and Africa is estimated to
increase and achieve the maximum around 2025 and decline thereafter. For other regions, the rural population would continually
decline in the forecast period.
Urban population in the world would continually grow and reach 4.72–5.00 billion in 2030, an increase of 48.6–57.8%. However
the annual growth of urban population is expected to increase to the maximum (6.86 million/year) during the period 2020–2025
and then decline in the following years. Urban population is projected to continually grow in all regions excepting Europe.
Europe’s urban population is expected to decline in the period 2010–2030. Urbanization process worldwide, represented by the
ratio urban population versus total population (RUT) and the ratio rural population versus urban population, is expected to
continue during the period 2010–2030. The RUT of the world is projected to reach 0.5 before 2010 and would continue to increase
in the forecast period. Global RUT is estimated to reach 0.56 in 2030. However, the regional patterns of urbanization process
would be diverse. Europe’s RUT is estimated to continually decline in the forecast period and reach 0.68 in 2030. The RUT
for Africa and Caribbean would continually increase before 2030, while the RUTs for Asia and South America are estimated to
achieve their maximums around 2025 and decline in the following years. Oceania and North & Central America would thoroughly
realize urbanization (≈1) during the periods 2020–2025 and 2025–2030. The expansion of world population and urbanization will
continually exert a stronger stress to environment quality and sustainable development in a near future. However we may expect
this situation would start to change from mid-21st century after total population has achieved its maximum.
Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
112.
本文介绍了二滩水电站环境影响评价,以及世界银行评估过程中专家提出的一系列环境问题,并结合我院10多年来的环境影响评价工作简述几点启示,供参考。 相似文献
113.
1991/1992年是厄尔尼诺年,也是全球自然灾害频发、重灾事件突出的异常年份。本文对发生在1991/1992年厄尔尼诺事件期间的全球主要气象灾害进行简介和评述。 相似文献
114.
庐山野生观赏植物资源的保护与开发利用 总被引:1,自引:0,他引:1
按园林用途对庐山的野生观赏植物资源进行了分类介绍,分析了在保护、开发和利用方面存在的问题,同时对野生观赏植物资源在我国园林生态建设方面的独特作用提出了一些建议. 相似文献
115.
In this paper we examine the reconstitution of the Emergency Operations Centre (EOC) after its destruction in the World Trade Center attack, using that event to highlight several features of resilience. The paper summarises basic EOC functions, and then presents conceptions of resilience as understood from several disciplinary perspectives, noting that work in these fields has sought to understand how a natural or social system that experiences disturbance sustains its functional processes. We observe that, although the physical EOC facility was destroyed, the organisation that had been established to manage crises in New York City continued, enabling a response that drew on the resources of New York City and neighbouring communities, states and the federal government. Availability of resources--which substituted for redundancy of personnel, equipment and space--pre-existing relationships that eased communication challenges as the emergency developed and the continuation of organisational patterns of response integration and role assignments were among the factors that contributed to resilience following the attack. 相似文献
116.
赣中南柑橘果实生长发育规律与栽培技术关系 总被引:1,自引:0,他引:1
通过果实体积的累积生长量,日均生长速度和相对生长速率三个指标的测定。可得到各类果实生长的“S”形曲线。生长呈三个时期,第一期为细胞分裂期,这个时期,生长速度较慢,而相对生长速率最高,是是实生长能力最高阶段;第二期为细胞膨大期,生长速度最快时期,而相对生长速率则呈下降趋势;第三期为成熟期,日均生长速度和相对生长速率都是低速和稳定时期。主要内部生理变化,柑橘各类果 个指标各异,此外,果实生长过程中,有 相似文献
117.
Jason Bradbury Phillip Cullen Grant Dixon Michael Pemberton 《Environmental management》1995,19(2):259-272
The wash from high-speed tourist cruise launches causes erosion of the formerly stable banks of the lower Gordon River within
the Tasmanian Wilderness World Heritage Area. Speed and access restrictions on the operation of commercial cruise vessels
have considerably slowed, but not halted erosion, which continues on the now destabilized banks. To assess the effectiveness
of restrictions, bank erosion and natural revegetation are monitored at 48 sites using erosion pins, survey transects, and
vegetation quadrats. The subjectively chosen sites are grouped on the basis of geomorphology and bank materials. The mean
measured rate of erosion of estuarine banks slowed from 210 to 19 mm/year with the introduction of a 9 knot speed limit. In
areas where cruise vessels continue to operate, alluvial banks were eroded at a mean rate of 11 mm/yr during the three-year
period of the current management regime. Very similar alluvial banks no longer subject to commercial cruise boat traffic eroded
at the slower mean rate of 3 mm/yr. Sandy levee banks have retreated an estimated maximum 10 m during the last 10–15 years.
The mean rate of bank retreat slowed from 112 to 13 mm/yr with the exclusion of cruise vessels from the leveed section of
the river. Revegetation of the eroded banks is proceeding slowly; however, since the major bank colonizers are very slow growing
tree species, it is likely to be decades until revegetation can contribute substantially to bank stability. 相似文献
118.
David Higdon 《Journal of Environmental Planning and Management》1986,29(2):91-95
The author contributed to a short ‘in service’ course for staff engaged on a World Bank upgrading project for Ethiopian housing. The project includes both the building of new houses by self‐build co‐operatives on the periphery of Addis Ababa, and the upgrading of a dense inner city area in conditions of acute deprivation. The paper is a highly personal account of the author's impressions of the value of such initiatives. 相似文献
119.
120.
走特色旅游之路,兴江西旅游经济——兼谈大力发展江西省地学旅游 总被引:2,自引:0,他引:2
2001年8月,江西省提出了发展全省经济的战略思想-“三个基地,一个后花园”。其中“后花园”就是指把江西省建设成为沿海发达地区游客旅游观光的好去处。但我国幅员辽阔,新奇奥妙的风光比比皆是,已有26个省份先后提出将旅游业作为优先发展的支柱产业,如果拿不出自己的特色旅游产品,就很难在日趋激烈的竞争旅游市场上将旅游资源优势转变为经济优势,作者以江西省地学旅游为例,对发展江西省特色旅游的可持续性,实施战略,意义等方面进行了较少深入的探讨,以期对江西省实现旅游大省的目标起到抛砖引玉的作用。 相似文献