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461.
A geochemical study of a red soil derived from plioquaternary materials was carried out. The soil was located in a region of complex geomorphology and pedologic evolution, with particular characteristics of a Mediterranean climate associated with processes of alteration, rubification, gleying (hydromorphism) and argillization. The depth distribution of 27 trace elements was studied in order to determine the amounts of these elements in the soil and its tendency. The mineralogy of the clay fraction was also studied along with other physico-chemical properties to elucidate in terms of attributes meaningful for viticulture. The geochemical composition of the horizons was studied. The effect of human activities on the soil was investigated as well as the geographical origin of Mancha wines. It was found that these activities did not give rise to significant variations of trace elements, although a discontinuity related to the accumulation of new materials was detected. Ultimately, using established productivity standards, suitability for the cultivation of vines on these soils was determined.  相似文献   
462.
ABSTRACT

Ozone prediction has become an important activity in many U.S. ozone nonattainment areas. In this study, we describe the ozone prediction program in the Atlanta metropolitan area and analyze the performance of this program during the 1999 ozone-forecasting season. From May to September, a team of 10 air quality regulators, meteorologists, and atmospheric scientists made a daily prediction of the next-day maximum 8-hr average ozone concentration. The daily forecast was made aided by two linear regression models, a 3-dimensional air quality model, and the no-skill ozone persistence model. The team's performance is compared with the numerical models using several numerical indicators. Our analysis indicated that (1) the team correctly predicted next-day peak ozone concentrations 84% of the time, (2) the two linear regression models had a better performance than a 3-dimensional air quality model, (3) persistence was a strong predictor of ozone concentrations with a performance of 78%, and (4) about half of the team's wrong predictions could be prevented with improved meteorological predictions.  相似文献   
463.
Anammox enrichments were readily developed from seven municipal wastewater treatment plants (WWTPs) sludge, but not with methanogenic granular sludge from two agro-industrial WWTPs. Only 50 d was required for the first evidence of anammox activity from a return activated sludge obtained from a WWTP operated for nutrient removal. The molar ratios of nitrite and ammonium consumption of approximately 1.32 as well as nitrate and dinitrogen gas product ratios of approximately 0.095 provided evidence of the anammox reaction. The presence of anammox was confirmed by polymerase chain reaction (PCR) using primer sets (PLA46F and AMX820R) specific for anammox bacteria. The 16S rRNA gene fragment of anammox bacteria was detected in seven enrichment cultures (ECs) with demonstrated anammox activity but not in the original inocula from which the ECs were derived and also not in the two methanogenic sludge samples, which indicates the PCR predicted the anammox activity. Two genera, Brocadia and Kuenenia, were successfully identified as the Planctomycetes occurring in the clone libraries of successful anammox enrichments. Brocadia dominated in cultures that were respiked extensively; whereas Kuenenia predominated in cultures that were less aggressively respiked. These findings indicate that respiking management may play an important role on selecting the genus of anammox bacteria. The batch enrichment results clearly illustrate that anammox can be readily enriched from municipal sludge from a wide variety of process operations at WWTPs.  相似文献   
464.
PAHs were analyzed in the liver of 5 species of pelagic seabirds (Procellariiformes) from the northeast Atlantic and the Mediterranean. The main objective was to assess the trophic and geographic trends of PAHs in seabirds to evaluate their suitability as bioindicators of chronic marine pollution by these compounds. Although higher levels of PAHs have been described in the Mediterranean compared to other oceanic regions, we did not find significant spatial patterns and observed only minor effects of the geographic origin on seabird PAHs. However, we found significant higher PAH levels in petrel compared to shearwater species, which could be related to differences in their exploitation of mesopelagic and epipelagic resources, respectively, and the vertical dynamic of PAHs in the water column. Overall, although this study enhances the need of multi-species approaches to show a more comprehensive evaluation of marine pollution, seabirds emerged as poor indicators of pelagic chronic PAH levels.  相似文献   
465.
Fragile X syndrome is the most common form of inherited mental retardation, due to an expansion of the (CGG)n trinucleotide repeat in the FMR-1 gene and hypermethylation of its 5′ upstream CpG island. Two major problems remain to be resolved for fragile X prenatal diagnosis: the abnormal methylation patterns of chorionic villus samples (CVS) and the inability to predict the mental status of females with the full mutation. We present here the results of ten prenatal diagnoses of fragile X syndrome using Southern blotting and polymerase chain reaction (PCR) amplification, and the analysis of 50 further CVS to test the methylation status of the CpG island of the FMR-1 gene. In the ten ‘at-risk’ CVS, eight normal (five males and three females) and two affected male fetuses were detected. Absence of methylation in the CVS was observed in two cases, which was not found upon subsequent examination of the newborn or of fetal tissues. In the 50 CVS not ‘at risk’ for fragile X syndrome, abnormal fragment patterns for probe StB12.3 were detected in 32 per cent for female and 24 per cent for male fetuses. This abnormal pattern could be due to absent or partial methylation of the CpG island of the FMR-1 gene in chorionic villus tissues.  相似文献   
466.
尿液中多环芳烃羟基代谢产物分析方法研究   总被引:9,自引:0,他引:9  
通过实验建立了"酶水解-固相萃取-HPLC 荧光检测"尿液中多环芳烃羟基代谢产物1-羟基芘,9-羟基苯并[a]芘和3-羟基苯并[a]芘的分析方法,研究了3种代谢产物在不同保存温度下的稳定性,并通过对200个实际尿液的测定初步验证了该方法的可行性。该方法回收率为70%~85%,最低检出限为0 02~0 05μg L。-20℃保存的尿液样品及尿液提取液中3种化合物在1个月内降解了10%~36%,提取液比尿液的稳定性稍好,保存温度越高稳定性越差。   相似文献   
467.
Most models of the incidence of occupational accidents in the construction industry are composed of multiple factors. Although statistical techniques can be used to infer cause-and-effect relationships among these factors, the large number of factors involved and the complexity of the relationships among them make it difficult for managers to identify potential hazards in construction projects and thus develop effective safety procedures. This study addresses this problem by using the association-rule method of data mining in performing an analysis of 1347 accidents in the Taiwan construction industry during the period 2000–2007. The association-rule method enables potential cause-and-effect relationships to be identified among the many factors that play a role in occupational accidents in the construction industry. The study finds that such accidents tend to occur when certain combinations of hazards are present – especially working in high places without protective measures, loss of balance when in motion, failure to use protective equipment, insufficient experience, and injurious contact with unstable structures. These hazards are especially evident in small enterprises with less than 10 persons. The results can help management to formulate effective safety policies with regard to management shortcomings and staff training.  相似文献   
468.
Driven by considerations of sustainability, it has become increasingly difficult over the past 15?C20 years ?? at least intellectually ?? to separate out the water infrastructure and water metabolism of cities from their intimately inter-related nutrient and energy metabolisms. Much of the focus of this difficulty settles on the wastewater component of the city??s water infrastructure and its associated fluxes of nutrients (N, P, C, and so on). Indeed, notwithstanding the massive volumes of these materials flowing into and out of the city, the notion of an urban nutrient infrastructure is conspicuous by its absence. Likewise, we do not tend to discuss, or conduct research into, ??soilshed?? agencies, or soilshed management, or Integrated Nutrient Resources Management (as opposed to its most familiar companion, Integrated Water Resources Management, or IWRM). The paper summarizes some of the benefits (and challenges) deriving from adopting this broader, multi-sectoral ??systems?? perspective on addressing water-nutrient-energy systems in city-watershed settings. Such a perspective resonates with the growing interest in broader policy circles in what is called the ??water-food-energy security nexus??. The benefits and challenges of our Multi-sectoral Systems Analysis (MSA) are illustrated through computational results from two primary case studies: Atlanta, Georgia, USA; and London, UK. Since our work is part of the International Network on Cities as Forces for Good in the Environment (CFG; see www.cfgnet.org), in which other case studies are currently being initiated ?? for example, on Kathmandu, Nepal ?? we close by reflecting upon these issues of water-nutrient-energy systems in three urban settings with quite different styles and speeds of development.  相似文献   
469.
用尿中1-羟基芘评价人体暴露PAHs的肺癌风险   总被引:3,自引:1,他引:3       下载免费PDF全文
 采集并分析了100名不吸烟成人24h呼吸的空气样品和尿液样品,建立了人尿中1-羟基芘(1-OH-Py)浓度与苯并(a)芘(BaP)、芘(Py)等14种多环芳烃(PAHs)呼吸暴露浓度的定量关系.参考现有关于BaP空气污染浓度与肺癌死亡率的剂量-反应关系模型,推导出用尿中1-OH-Py预测人体呼吸暴露PAHs的肺癌风险模型.用建立的模型对100名受试者进行了肺癌风险评价,结果表明,一般人群BaP暴露的肺癌风险约为11/10万,焦炉工人约为160/10万;若同时考虑14种PAHs的BaP当量毒性,则其相应肺癌风险要高出约0.5倍.一般人群的尿中1-OH-Py的生物暴露限值为0.11μmol/mol肌酐,焦炉工人为1.90μmol/mol肌酐.  相似文献   
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