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211.
212.
涂料行业废气污染物属于复杂未知体系,常规方法难以进行全面准确的定性定量分析。采用GC/MS法测定涂料行业废气化学成分,利用化学计量学解析法(CRM)对谱图中的色谱峰进行逐一解析,得到各组分的纯色谱曲线和质谱,通过质谱库匹配进行定性,用解析色谱曲线积分法进行定量。从20个色谱峰中解析出了47个组分,鉴定了其中39个化合物,占总含量的90.86%。涂料废气污染物的主要化学成分为苯系物,占总含量的47.88%。该法能对重叠峰进行解析,降低对色谱注的要求,为快速、准确解析复杂未知样本提供了崭新途径。 相似文献
213.
以位于喀斯特高原区的王家寨小流域为例,运用SPOT5影像(空间分辨率2.5米)、ASTER影像(空间分辨率15米)、TM影像(空间分辨率30米)为基本数据源,深入分析空间分辨率的变化对土地覆盖分类结果的影响。随着影像空间分辨率的增加,三种不同空间分辨率影像的土地覆盖分类信息的变化归纳为三种类型:增加型(灌木丛、农村居民点、裸岩裸土),减少型(旱地、稀疏林地),波动型(水田、有林地)。尤以能反映生态质量的裸岩裸土和低被草地斑块的变化较大,高分辨率影像显然能更多的识别出对流域生态质量有影响的生态系统类型。 相似文献
214.
江苏省作为我国的经济大省,对其进行环境持久性药物污染物(EPPPs)的污染特征与生态风险评估研究很有必要.本研究以江苏省1~4级河流和面积≥50 km2的湖泊为研究目标,对EPPPs的污染现状进行检测和分析.结果表明,江苏省地表水中共检出35种EPPPs,浓度范围为66.74~2189.83 ng·L-1;该研究主要对检出率大于25%的17种EPPPs进行了探讨,其浓度水平为72.48~1142.79 ng·L-1,浓度均值为345.20 ng·L-1.EPPPs总浓度水平苏北和苏南浓度水平高于苏中地区.其中扬州市EPPPs浓度全省最高,可能主要污染来源为生活污水、航运污水排放及渔业养殖中的药物使用.EPPPs总浓度整体以京杭运河、废黄河为中线向两侧递减.对17种EPPPs的生态风险评估表明,单一目标药物对江苏省水生态风险较小;采用简单叠加模型计算出的联合毒性风险商范围为0.03~0.52,联合毒性对水生生物表现为低至中等风险. 相似文献
215.
Abstract: Over the last decade, 2 major U.S. commissions on ocean policy and a wide range of independent sources have argued that ocean ecosystems are in a period of crisis and that current policies are inadequate to prevent further ecological damage. These sources have advocated ecosystem-based management as an approach to address conservation issues in the oceans, but managers remain uncertain as to how to implement ecosystem-based approaches in the real world. We argue that the philosophies of Edward F. Ricketts, a mid-20th-century marine ecologist, offer a framework and clear guidance for taking an ecosystem approach to marine conservation. Ricketts' philosophies, which were grounded in basic observations of natural history, espoused building a holistic picture of the natural world, including the influence of humans, through repeated observation. This approach, when applied to conservation, grounds management in what is observable in nature, encourages early action in the face of uncertainty, and supports an adaptive approach to management as new information becomes available. Ricketts' philosophy of "breaking through," which focuses on getting beyond crisis and conflict through honest debate of different parties' needs (rather than forcing compromise of differing positions), emphasizes the social dimension of natural resource management. New observational technologies, long-term ecological data sets, and especially advances in the social sciences made available since Ricketts' time greatly enhance the utility of Ricketts' philosophy of marine conservation. 相似文献
216.
Masashi Kiyota Stephen J. Insley Stacey L. Lance 《Behavioral ecology and sociobiology》2008,62(5):739-746
We conducted a 6-year longitudinal behavioral and genetic investigation of a highly polygynous pinniped, the northern fur
seal (Callorhinus ursinus), to determine the contribution of terrestrial polygyny to male fertilization success and to assess the occurrence of alternative
mating strategies. Genetic samples from 37 adult males, 50 adult females, and 85 pups were collected and genotyped using five
polymorphic microsatellite loci. Pup paternity was assigned using Cervus 2.0 at 99% confidence level. Paternity of 83 pups
(98%) was assigned to terrestrial males who held territories or stayed temporarily in the study area during the breeding season
when fertilization occurred. For 56 pups of which attendance records of their mothers were available, paternity of 45 pups
(80%) was assigned to the associate males in whose territory their mothers stayed during the perioestrus period. In addition
to defending breeding territories, territorial males have often been observed attempting to forcibly abduct adult females
from adjacent territories (female stealing): We observed a total of 95 such cases, in which the stealers had significantly
fewer females than the territorial males from whose territories they stole females. Our results indicate that terrestrial
resource-defense polygyny is the major mating system in this species and that nonassociated paternity occurs mostly as a result
of alternative mating strategies of less successful males. Male northern fur seals thus appear to adopt conditional alternative
strategies that depend on their current social status to maximize their life-time reproductive success. 相似文献
217.
Ivo H. Machatschke Barbara E. Bauer Cornelia Schrauf John Dittami Bernard Wallner 《Behavioral ecology and sociobiology》2008,62(8):1341-1350
Polygynous mating systems can inflict considerable costs on males, often causing the emergence of alternative mating strategies
to ensure reproductive success. These strategies can lead to different morphs of color, size, or behavior. The present work
was done on guinea pigs, a polygynous rodent species. Some males can show a reduced readiness for conflict, perhaps employing
an alternative mating strategy. To test this hypothesis, a two-stage experiment was set up, with males (N = 16) and females (N = 16) initially living in isosexual groups. Visual and olfactory contact was possible through a wire mesh. Male agonistic
behavior was observed for 15 days, confirming the existence of less-conflict-involved (LCI, N = 7) and more-conflict-involved males (MCI, N = 9). Significant differences were found for a conditional parameter, body mass, and a morphometric one, testis width: LCI
consistently surpassed MCI. Hormonally, cortisol was comparable, while testosterone was distinctly higher in MCI. Next, males
and females were joined and observed for further 24 days. Males initially lost weight but reached original mass towards the
end of the experiment. Testis width patterns were similar. Again, LCI had higher body mass. Cortisol was comparable, but testosterone
release 3 days after merging was significantly higher in LCI. Behaviorally, LCI exhibited significantly less male–male aggression
and more socio-sexual behavior than MCI. The former were more successful, with 57% capable of accessing females, in contrast
to 11% of MCI. The existence of two distinct behavioral phenotypes in guinea pig males suggests that different reproductive
strategies may exist in this species. 相似文献
218.
219.
Li Chen Rina Schumer Anna Knust William Forsee 《Journal of the American Water Resources Association》2012,48(1):145-155
Chen, Li, Rina Schumer, Anna Knust, and William Forsee, 2011. Impact of Temporal Resolution of Flow‐Duration Curve on Sediment Load Estimation. Journal of the American Water Resources Association (JAWRA) 48(1): 145‐155. DOI: 10.1111/j.1752‐1688.2011.00602.x Abstract: Estimates of a channel’s annual sediment transport capacity typically incorporate annualized flow‐duration curves. Average daily flow data, commonly used to develop flow‐duration curves, may not adequately describe sediment‐transporting flows in arid and semiarid ephemeral streams. In this study, we examined impacts of varied temporal resolution flow data on annual sediment load estimation. We derived flow‐duration curves for eight sites in the Southwestern United States based on both 15‐min and daily‐averaged flow data. We then estimated sediment loads for both flow‐duration curves using the Sediment Impact Analysis Method, implemented in HEC‐RAS. When average daily flow is used to generate flow‐duration curves, sediment load estimation is lower by up to an order of magnitude. This trend is generally unaffected by uncertainty associated with sediment particle size or hydraulic roughness. The ratio of sediment loads estimated by 15‐min versus daily‐averaged flow‐duration curves is strongly correlated with channel slope, being greater on steep‐slope channels. Sediment loads estimated by the two types of flow‐duration curves are closely correlated, suggesting possible relationships for improving predictions when high‐temporal resolution data are unavailable. Results also suggest that the largest flow contributes significantly to total sediment load, and thus will greatly impact ephemeral stream geomorphology in arid and semiarid regions. 相似文献
220.