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131.
132.
X射线荧光光谱分析法在土壤样品多元素分析中的应用 总被引:3,自引:0,他引:3
用Epsilon5偏振能量色散X射线荧光光谱仪测定土壤样品中27种元素。方法的准确度用GBW07323和GSS-32标准样品验证,结果均在标准值范围内。方法的精密度用GBW07401标准样品检验,除Ni、Mo、Se和Pr四种元素的RSD〉10%外,其余被测元素的RSD均〈6.3%。实验表明用X射线荧光光谱分析法测定土壤样品中多种元素,具有方法简便、灵敏、准确,检出限低等特点。 相似文献
133.
Abboud IA 《Environmental geochemistry and health》2008,30(1):11-20
Due to the increase in the number of urinary calculi disease cases in Jordan, stone samples were collected from patients from
various Jordanian hospitals (Princes Basma (PBH), King Abdullah University (KAUH), Al-Basheer (ABH) and Al-Mafraq (AMH)).
This study concentrates on the effect of trace metals in patients of urinary calculi. Trace metals were detected in 110 urinary
calculi samples using X-ray fluorescence (XRF) and atomic absorption spectroscopy (AAS) techniques. Of the calculi examined,
21 were pure calcium oxalate (CaOax), 29 were mixed calcium oxalate/uric acid, 23 were mixed calcium oxalate/phosphate (apatite),
25 were phosphate calculi (apatite/struvite), five were mixed calcium oxalate monohydrate/struvite, four were urate calculi
(mixed ammonium acid urate/sodium acid urate) and three were pure cystine calculi. The concentration measurement of Ca and
other trace metals levels has been found useful in understanding the mechanism of stone formation and in evaluating pathological
factors. It has been found that Ca is the main constituent of the urinary calculi, especially those stones composed of calcium
oxalate and calcium phosphate. The concentration of most of the trace metals that were analyzed was (Ca = 48.18, Na = 1.56,
K = 0.9, Mg = 3.08, Fe = 1.17, Al = 0.49, Zn = 0.7, Cu = 0.19, Mn = 0.029, P = 10.35, S = 1.88, Sr = 0.306, Mo = 0.2, Cr = 0.146,
Co = 0.05, Ni = 0.014)%. In conclusion, metals concentration in Jordanian patient’s urinary calculi samples was higher than
its equivalents of other patients’. It has been noted that there is no concentration of toxic trace elements (like Li, V,
Pb, Cd, and As). Some heavy metals, however, were detected Mo, Cr, Co and Ni as traces. P and S ions are present in few calculi
stones as traces. 相似文献
134.
The role of radial oxygen loss and root anatomy on zinc uptake and tolerance in mangrove seedlings 总被引:1,自引:0,他引:1
H. Cheng N.F.Y. Tam S.Y. Li Z.H. Ye 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1189-1196
Root anatomy, radial oxygen loss (ROL) and zinc (Zn) uptake and tolerance in mangrove plants were investigated using seedlings of Aegiceras corniculatum, Bruguiera gymnorrhiza and Rhizophora stylosa. The results revealed that B. gymnorrhiza, which possessed the ‘tightest barrier’ in ROL spatial patterns among the three species studied, took up the least Zn and showed the highest Zn tolerance. Furthermore, zinc significantly decreased the ROL of all three plants by inhibition of root permeability, which included an obvious thickening of outer cortex and significant increases of lignification in cell walls. The results of SEM X-ray microanalysis further confirmed that such an inducible, low permeability of roots was likely an adaptive strategy to metal stress by direct prevention of excessive Zn entering into the root. The present study proposes new evidence of structural adaptive strategy on metal tolerance by mangrove seedlings. 相似文献
135.
Riddell N Becker R Chittim B Emmerling F Köppen R Lough A McAlees A McCrindle R 《Chemosphere》2011,84(7):900-907
Technical 1,2,5,6,9,10-hexabromocyclododecane (HBCD) consists largely of three diastereomers (α-, β-, and γ-HBCD) produced by the trans addition of bromine to cis,trans,trans-cyclododeca-1,5,9-triene (CDT). However, another seven diastereomers are theoretically possible and may be produced by trans addition of bromine across the double bonds of the other three isomers of 1,5,9-CDT. There are indications that small amounts of the minor HBCD isomers may be present in commercial HBCD mixtures or in products containing this brominated flame retardant (BFR). Such minor components may indeed derive from traces of other 1,5,9-CDTs in the cis, trans, trans starting material, however their formation may also be possible through isomerizations during the processing of this BFR or by bioisomerization subsequent to its release into the environment. Two of the seven additional diastereomers (δ- and ε-HBCD) were synthesized previously from trans,trans,trans-CDT. We now report the preparation of the remaining five diastereomers, ζ-, η-, and θ-HBCD from cis,cis,trans-CDT and ι- and κ-HBCD from cis,cis,cis-CDT, and their characterization by 1H NMR spectroscopy and X-ray crystallography. The availability of these further diastereomers of HBCD should aid in determining if the minor isomers are present in commercial samples of this BFR, in products containing HBCDs, or in environmental samples. We have also carried out an X-ray crystal structure determination on ε-HBCD, so that crystal structures are now available for all 10 HBCD diastereomers. 相似文献
136.
Tian SK Lu LL Yang XE Huang HG Brown P Labavitch J Liao HB He ZL 《Environmental pollution (Barking, Essex : 1987)》2011,159(3):782-788
The in vivo localization and speciation of lead (Pb) in tissues of the accumulator Sedum alfredii grown in EDTA-Pb and Pb(NO3)2 was studied by synchrotron X-ray investigation. The presence of EDTA-Pb in solution resulted in a significant reduction of Pb accumulation in S. alfredii. Lead was preferentially localized in the vascular bundles regardless of treatments but the intensities of Pb were lower in the plants treated with EDTA. Lead was predominantly presented as a Pb-cell wall complex in the plants regardless of its supply form. However, a relatively high proportion of Pb was observed as Pb-EDTA complex when the plant was treated with EDTA-Pb, but as a mixture of Pb3(PO4)2, Pb-malic, and Pb-GSH when cultured with ionic Pb. These results suggest that EDTA does not increase the internal mobility of Pb, although the soluble Pb-EDTA complex could be transported and accumulated within the plants of S. alfredii. 相似文献
137.
Saffarzadeh A Shimaoka T Wei Y Gardner KH Musselman CN 《Waste management (New York, N.Y.)》2011,31(12):2440-2454
Natural weathering processes are significant mechanisms that noticeably affect the fundamental nature of incineration ash residues. To provide a greater understanding of these processes, a MSWI (mono)landfill site in the north east of the US was selected as the target for systematic investigation of the natural weathering of bottom ash residues. Samples of various ages were collected from locations A (1 yr), B (10 yrs), C (13-14 yrs) and D (20 yrs) of the landfill in 2009. We investigated the phase transformation of the collected bottom ash particles, neoformation processes as well as the behavior and distribution of certain heavy metals (Cu, Pb, Zn, Ni, and Cr) in the neoformed phases using optical microscopy, SEM-EDX, and bulk examinations. Key findings: at the preliminary stage, the waste metallic particles (Al, Fe, and Cu) and unstable minerals such as lime, portlandite, ettringite and hydrocalumite convert to oxide and hydroxide (hydrate) phases, calcite, alumina gel and gypsum. At the intermediate stage, the decomposition of melt products including magnetite spinels and metallic inclusions is triggered due to the partial dissolution of the melt glass. At the longer time horizon it is possible to track the breakdown of the glass phase, the extensive formation of calcite and anhydrite, Al-hydrates and more stable Fe-hydrates all through the older ash deposits. Among the dominant secondary phases, we propose the following order based on their direct metal uptake capacity: Fe-hydrates>Al-hydrates>calcite. Calcite was found to be the least effective phase for the direct sorption of heavy metals. Based on overall findings, a model is proposed that demonstrates the general trend of ash weathering in the landfill. 相似文献
138.
Lu Y Sun X Ji SY Wang JF Huang YJ Zhao YF Xu PX 《Environmental monitoring and assessment》2007,130(1-3):281-287
HPLC and HPLC-MS are the fastest and most accurate techniques for analysis of organic phosphorus pesticide (OPP) at the present
time. Using these techniques, 14 strains of methamidopho (MAP) degrading-bacteria from the area contaminated with MAP have
been identified. The results from HPLC and HPLC-MS analyses showed that the highest degradation rate was 73% after 7 days.
In order to determine what metabolites will be formed after degradation, a key issue that has been neglected for a long time,
we used (31P) NMR to track the degradation process. The results showed that different strains produced different metabolites. Ten strains
were divided into three groups (groups A, B and C) by their metabolic profiling. Strains in group A degraded MAP into phosphor
acid by breaking down all P–N, P–O and P–S bonds in 7 days. Strains in groups B and C had only broken down partially P–N and
P–S bonds at the same time. Therefore, the bacterial strains in group A had a greater application potential than the other
two groups. In addition, most metal phosphates are unsolvable in water. The analysis of X-ray showed, that the phosphate radicals
generated by bacterial degradation induce crystallogenesis of heavy metal salts in water phase and also cause the chemical
sedimentation of their crystals. Furthermore, these crystals are hydrogen phosphates. The results suggested that the MAP-degrading
bacteria could be used for cleaning up not only the organic phosphorous pesticide contamination but also the phosphorous and
heavy metal contamination in water environment simultaneously. 相似文献
139.
表面活性剂与Pb、Zn协同作用对蚕豆叶细胞的损伤 总被引:2,自引:0,他引:2
采用透射电子显微镜及能量发散X-射线微量分析技术,研究了非离子型表面活性剂烷基酚聚氧乙烯醚(AE)与矿山尾砂中高浓度Pb、Zn协同作用对蚕豆叶细胞的损伤.结果表明,高浓度Pb、Zn使蚕豆叶绿体中类囊体解体,嗜锇颗粒的数量和体积显著增加.细胞外间隙和液泡中出现大量的不溶性毛发状晶体.AE与Pb、Zn复合污染时,细胞内膜结构的透性增加,细胞内毛发状晶体扩散到叶绿体、细胞核中.因此,AE可加重Pb、Zn对蚕豆叶细胞的损伤作用,毛发状晶体的形成可能与细胞脱毒有关. 相似文献
140.