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81.
准确求出地下水污染物迁移的水动力参数,是成功预防并控制地下水污染的重要基础。该文将复形调优法运用于弥散实验中地下水溶质水动力参数的确定,并与其他方法进行比较。结果表明,复形调优法仅需一个观测井的监测资料即可,且计算简便、结果可信,这对提高野外弥散实验的成功率及经济性具一定的积极意义。 相似文献
82.
聊古一井地下流体场源兆异常特征及震情预测检验 总被引:1,自引:0,他引:1
聊古一井由于其所处的特殊构造部位、良好的水文地质条件、井孔条件和连续可靠的观测,获得了一批有价值的实际地震观测资料,该井水化学组分的异常变化对其周围500 km范围内的5级以上地震具有良好的映震能力。在对聊古一井自1981-01投测以来观测到的水化学地震前兆异常进行综合分析的基础上,探讨了聊古一井水化学异常变化的场源兆特征及异常形成的物理力学机制和地震预报意义。利用上述研究结果,对聊古一井气体总量2003-05~2003-10出现的低值异常变化进行了分析和震情预测,取得较好的效果。 相似文献
83.
桩基础质量的检测是保证基础工程安全的重要措施。针对传统的检测方法静荷载试验法和钻孔取芯法存在的设备笨重、成本高、工期长和检测数量少的缺点 ,提出了用反射波法进行桩基无损检测 ,该法较传统的检测法具有成本低、效率高和可靠性高的特点。最后 ,将反射波法用于天津市红桥区工商行大厦砼钻孔灌注桩桩基的无损检测 ,结合实测的桩基速度波分析了检测到的桩基缺陷类型及判断原则。 相似文献
84.
85.
张文香 《中国环境管理干部学院学报》2009,19(3):93-95
在抚宁县城城市空间形态研究中,通过对功能分区的划分、公共开敞空间的确定、道路景观轴线及视线通廊的控制、城市整体高度的组织,打造和谐共生的城市组团、营造充满魅力的公园、活力的社区邻里和文化内涵丰富的街区,旨在激发城市的活力,创造一个以自然生态环境为特色,以休闲度假、商务会议和生活居住为主体、充满活力的和谐城市。 相似文献
86.
LIANG Xin-qiang CHEN Ying-xu LI Hu TIAN Guang-ming ZHANG Zhi-jian NI Wu-zhong HE Miao-miao 《环境科学学报(英文版)》2007,19(12):1474-1481
A field experiment located in Taihu Lake Basin of China was conducted,by application of urea or a mixture of urea with manure, to elucidate the interception of nitrogen(N)export in a typical rice field through"zero-drainage water management"combined with sound irrigation,rainfall forecasting and field drying,N concentrations in floodwater rapidly declined before the first event of field drying after three split fertilizations,and subsequently tended to retum to the background level.Before the first field drying,total particulate nitrogen(TPN)was the predominant N form in floodwater of plots with no N input,dissolved inorganic nitrogen(DIN)on plots that received urea only,and dissolved organic nitrogen(DON)on plots treated with the mixture of urea and manure.Thereafter TPN became the major form.No N export was found from the rice field,but total nitrogen(TN)of 15.8 kg/hm~2 was remained,mainly due to soil N sorption.The results recommended the zero-drainage water management for full-scale areas for minimizing N export. 相似文献
87.
Seth Payton Greg Lindsey Jeff Wilson John R. Ottensmann Joyce Man 《Journal of Environmental Planning and Management》2008,51(6):717-736
This paper measures the benefits of the urban forest by examining its effect on housing prices. A Geographic Information System is used to develop a measure of the urban forest, the Normalised Difference Vegetation Index, from satellite imagery and to construct other variables from a variety of sources. Spatial hedonic housing price models for the Indianapolis/Marion County area are estimated. The models indicate that greener vegetation around a property has a positive, significant effect on housing price, holding everything else constant. This effect is dominated by measures at the neighborhood level. These findings indicate that property owners value the urban forest, at least in part, by the premium they pay to live in neighborhoods with greener, denser vegetation. These findings also indicate that public action to maintain and enhance the urban forest may be warranted. Planners and urban foresters can use these findings to inform public and policy debates over urban forestry programs and proposals. 相似文献
88.
Brigitte Simon-Bouy Agnès Taillandier Delphine Fauvert Isabelle Brun-Heath Jean-Louis Serre Carmen G. Armengod Martin G. Bialer Michèle Mathieu Jacques Cousin David Chitayat Jan Liebelt Barbara Feldman Marion Gérard-Blanluet Stefani Körtge-Jung Cath King Hannele Laivuori Martine Le Merrer Sarju Mehta Christina Jern Saba Sharif Fabienne Prieur Gabriele Gillessen-Kaesbach Andreas Zankl Etienne Mornet 《黑龙江环境通报》2008,28(11):993-998
89.
攀枝花市攀钢工业区土壤重金属污染特征及评价 总被引:2,自引:0,他引:2
本文对攀枝花市攀钢工业区土壤中五种重金属元素(Cu、Pb、Zn、Cr、Cd)的空间的分布特征、形态分布特征进行了研究,并应用污染负荷指数法对各重金属的污染程度进行了评价。研究发现,Cu、Pb、Zn、Cr的最大值与最小值分别相差2.98、3.4、5.2、2.7倍,cd的最大值与最小值甚至相差15.7倍。重金属元素相关性特征可分为Cd—Pb—Zn和Cu—Cr两组。形态分布特征表现在Cu、Zn、Pb、Cr主要以稳定的残渣态存在,Cd主要以可利用性最强的可交换态和碳酸盐结合态存在。污染较严重的是攀钢机关、攀钢原料场。 相似文献
90.
TARCISO C. C. LEÃO CARLOS R. FONSECA CARLOS A. PERES MARCELO TABARELLI 《Conservation biology》2014,28(5):1349-1359
Understanding how plant life history affects species vulnerability to anthropogenic disturbances and environmental change is a major ecological challenge. We examined how vegetation type, growth form, and geographic range size relate to extinction risk throughout the Brazilian Atlantic Forest domain. We used a database containing species‐level information of 6,929 angiosperms within 112 families and a molecular‐based working phylogeny. We used decision trees, standard regression, and phylogenetic regression to explore the relationships between species attributes and extinction risk. We found a significant phylogenetic signal in extinction risk. Vegetation type, growth form, and geographic range size were related to species extinction risk, but the effect of growth form was not evident after phylogeny was controlled for. Species restricted to either rocky outcrops or scrub vegetation on sandy coastal plains exhibited the highest extinction risk among vegetation types, a finding that supports the hypothesis that species adapted to resource‐limited environments are more vulnerable to extinction. Among growth forms, epiphytes were associated with the highest extinction risk in non‐phylogenetic regression models, followed by trees, whereas shrubs and climbers were associated with lower extinction risk. However, the higher extinction risk of epiphytes was not significant after correcting for phylogenetic relatedness. Our findings provide new indicators of extinction risk and insights into the mechanisms governing plant vulnerability to extinction in a highly diverse flora where human disturbances are both frequent and widespread. Predicción del Riesgo de Extinción de Angiospermas del Bosque Atlántico Brasileño 相似文献