全文获取类型
收费全文 | 454篇 |
免费 | 1篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 14篇 |
废物处理 | 10篇 |
环保管理 | 56篇 |
综合类 | 35篇 |
基础理论 | 74篇 |
污染及防治 | 191篇 |
评价与监测 | 57篇 |
社会与环境 | 19篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2014年 | 2篇 |
2013年 | 1篇 |
2012年 | 39篇 |
2011年 | 54篇 |
2010年 | 8篇 |
2009年 | 7篇 |
2008年 | 57篇 |
2007年 | 52篇 |
2006年 | 37篇 |
2005年 | 38篇 |
2004年 | 29篇 |
2003年 | 37篇 |
2002年 | 20篇 |
2001年 | 14篇 |
2000年 | 11篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1988年 | 1篇 |
1987年 | 6篇 |
1986年 | 1篇 |
1985年 | 2篇 |
排序方式: 共有458条查询结果,搜索用时 15 毫秒
451.
Qafoku NP Ainsworth CC Szecsody JE Bish DL Young JS McCready DE Qafoku OS 《Journal of environmental quality》2003,32(6):2364-2372
The high-level radioactive, Al-rich, concentrated alkaline and saline waste fluids stored in underground tanks have accidentally leaked into the vadose zone at the Hanford Site in Washington State. In addition to dissolution, precipitation is likely to occur when these waste fluids contact the sediments. The objective of this study was to investigate the solid phase transformations caused by dissolution and precipitation in the sediments treated with solutions similar to the waste fluids. Batch experiments at 323 K were conducted in metal- and glass-free systems under CO2 and O2 free conditions. Results from X-ray diffraction (XRD), quantitative X-ray diffraction (QXRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and energy dispersive X-ray fluorescence spectroscopy (EDXRF) indicated that significant solid phase transformations occurred in the sediments contacted with Al-rich, hyperalkaline, and saline solutions. The XRD and QXRD analyses confirmed that smectite and most likely biotite underwent dissolution. The SEM and the qualitative EDS analyses confirmed the formation of alumino-silicates in the groups of cancrinite and probably sodalite. The morphology of the alumino-silicates secondary phases changed in response to changes in the Si/Al aqueous molar ratio. The transformations in the sediments triggered by dissolution (weathering of soil minerals) and precipitation (formation of secondary phases with high specific surface area and probably high sorption capacities) may play a significant role in the immobilization and ultimate fate of radionuclides and contaminants such as Cs, Sr, and U in the Hanford vadose zone. 相似文献
452.
Baxter CA Joern BC Ragland D Sands JS Adeola O 《Journal of environmental quality》2003,32(4):1481-1489
Phosphorus-based land application limits for manure have increased the importance of optimizing diet P management and accurately characterizing the bioavailability of manure P. We examined the effects of pig (Sus scrofa) diets formulated with high-available-P corn and phytase on P levels in excreta and slurry stored for 30, 60, 90, 120, and 150 d. Twenty-four pigs (approximately 14 kg each) were fed one of four low-P diets: (i) normal corn, no phytase (control); (ii) normal corn with 600 phytase units kg(-1) (PHY); (iii) high-available-P corn, no phytase (HAP); and (iv) high-available-P corn with 600 phytase units kg(-1) (HAP + PHY). Fresh fecal and stored slurry dry matter (DM) was analyzed for total phosphorus (TP), dissolved molybdate-reactive phosphorus (DRP), dissolved organic phosphorus (DOP), acid-soluble reactive phosphorus (ASRP), acid-soluble organic phosphorus (ASOP), and phytate phosphorus (PAP). The PHY, HAP, and HAP + PHY diets significantly (alpha = 0.05) decreased fecal TP 19, 17, and 40%, respectively, compared with the control. Dissolved reactive P was 36% lower in the HAP + PHY diet compared with the other diets. Relative fractions (percent of TP) of DRP, DOP, ASOP, and PAP in slurry generally decreased with storage time up to 150 d, with the largest decreases occurring within 60 to 90 d. Diet-induced differences in relative fractions of DRP, DOP, ASRP, and PAP were significant when averaged across storage times, simulating a mixed-age slurry. Relative fractions of DRP in simulated mixed-age slurries were higher in HAP and HAP + PHY diets, indicating that diet may affect P losses under certain P-based application scenarios. 相似文献
453.
Cabreira SF Schultz CL Bittencourt JS Soares MB Fortier DC Silva LR Langer MC 《Die Naturwissenschaften》2011,98(12):1035-1040
Post-Triassic theropod, sauropodomorph, and ornithischian dinosaurs are readily recognized based on the set of traits that
typically characterize each of these groups. On the contrary, most of the early members of those lineages lack such specializations,
but share a range of generalized traits also seen in more basal dinosauromorphs. Here, we report on a new Late Triassic dinosaur
from the Santa Maria Formation of Rio Grande do Sul, southern Brazil. The specimen comprises the disarticulated partial skeleton
of a single individual, including most of the skull bones. Based on four phylogenetic analyses, the new dinosaur fits consistently
on the sauropodomorph stem, but lacks several typical features of sauropodomorphs, showing dinosaur plesiomorphies together
with some neotheropod traits. This is not an exception among basal dinosaurs, the early radiation of which is characterized
by a mosaic pattern of character acquisition, resulting in the uncertain phylogenetic placement of various early members of
the group. 相似文献
454.
455.
Investigation and risk assessment modeling of As and other heavy metals contamination around five abandoned metal mines in Korea 总被引:3,自引:0,他引:3
Tailings, agricultural soils, vegetables and groundwater samples were collected from abandoned metal mines (Duckum, Dongil,
Dongjung, Myoungbong and Songchun mines) in Korea. Total concentrations of arsenic (As) and heavy metals (Cd, Cu, Pb and Zn)
were analyzed to investigate the contamination level. Several digestion methods (Toxicity characteristics leaching procedure
(TCLP), synthetic precipitation leaching procedure (SPLP), 0.1 N/1 N HCl) and sequential extraction analysis for mine tailings
were conducted to examine the potential leachability of As and heavy metals from the tailings. The order of urgent remediation
for the studied mines based on the risk assessment and remedial goals was suggested.
The Songchun mine tailings were most severely contaminated by As and heavy metals. Total concentrations of As and Pb in the
tailings were 38,600–58,700 mg/kg (av. 47,400 mg/kg) and 11,800–16,800 mg/kg (av. 14,600 mg/kg), respectively. Agricultural
soils having high As concentrations were found at the all mines. Average concentrations of Cd in the vegetables exceeded the
normal value at all mines areas, while As only at the Dongjung, Myoungbong, and Songchun mine area. One groundwater sample
each from the Dongil and Myoungbong mines, and 4 groundwater samples from the Songchun mine had values above 10 μg/L of As
concentration.
The TCLP method revealed that only Pb in the Songchun tailings, 6.49 mg/L, exceeded the regulatory level (5 mg/L). Employing
the 1-N HCl digestion method, the concentration of As in the Songchun mine tailings, 4,250 mg/kg, was up to 3,000 times higher
than its Korean countermeasure standard. Results from the sequential extraction of As in the tailings showed that the easily
releasable fraction in the Myoungbong and Songchun mine tailings was more than 30% and the residual fraction was less than
40%.
Based on results showing the exposure health risk employing the hazard quotient and cancer risk of As, Cd and Zn, the Dongil
mine needs the most urgent remedial action. The concentration reduction factor (CRF) of As in both soil and groundwater follows
the order: Songchun>Dongjung>Dongil>Myoungbong>Duckum mine. 相似文献
456.
Exposure to polybrominated diphenyl ethers associated with consumption of marine and freshwater fish in Hong Kong 总被引:2,自引:1,他引:2
Concentrations of polybrominated diphenyl ethers (PBDEs) in market fish have not previously been reported in Hong Kong. Axial and ventral muscles from 10 each common species of freshwater and marine fish purchased from markets in Hong Kong were analyzed for 22 PBDEs. Among the 10 freshwater fish species, spotted snakehead (Channa maculate) contained the highest level of PBDEs in ventral muscle (130 ng g(-1) wet wt.). For marine fish, bigeye (Priacanthus macracanthus) showed significantly higher levels of PBDEs (60.7 ng g(-1)wet wt. in ventral tissue) than all other marine species. The levels of PBDEs in fish samples ranged from 0.53 to 130 ng g(-1)wetwt. The tetrabrominated congener BDE-47 and pentabrominated BDE-99 were the predominant congeners, which accounted for 27% and 30%, respectively, of the total PBDEs. Daily PBDE intake was calculated according to the different fish consumption rate for Hong Kong consumers, and the results ranged from 222 to 1198 ng day(-1) for marine fish and 403-2170 ng day(-1) for freshwater fish. The daily PBDE intake from fish reported here were higher than those reported from the United States (8.94-15.7 ng day(-1)) and Europe (14-23.1 ng day(-1)). 相似文献
457.
Bioremediation of diesel-contaminated soil with composting 总被引:22,自引:0,他引:22
Namkoong W Hwang EY Park JS Choi JY 《Environmental pollution (Barking, Essex : 1987)》2002,119(1):23-31
The major objective of this research was to find the appropriate mix ratio of organic amendments for enhancing diesel oil degradation during contaminated soil composting. Sewage sludge or compost was added as an amendment for supplementing organic matter for composting of contaminated soil. The ratios of contaminated soil to organic amendments were 1:0.1, 1:0.3, 1:0.5, and 1:1 as wet weight basis. Target contaminant of this research was diesel oil, which was spiked at 10,000 mg/kg sample on a dry weight basis. The degradation of diesel oil was significantly enhanced by the addition of these organic amendments relative to straight soil. Degradation rates of total petroleum hydrocarbons (TPH) and n-alkanes were the greatest at the ratio of 1:0.5 of contaminated soil to organic amendments on wet weight basis. Preferential degradation of n-alkanes over TPH was observed regardless of the kind and the amount of organic amendments. The first order degradation constant of n-alkanes was about twice TPH degradation constant. Normal alkanes could be divided in two groups (C10-C15 versus C16-C20) based on the first order kinetic constant. Volatilization loss of TPH was only about 2% of initial TPH. Normal alkanes lost by volatilization were mainly by the compounds of C10 to C16. High correlations (r=0.80-0.86) were found among TPH degradation rate, amount of CO2 evolved, and dehydrogenase activity. 相似文献
458.
Sequential washing techniques using single or dual agents [sodium hydroxide (NaOH) and hydrochloric acid (HCl) solutions] were applied to arsenic-contaminated soils in an abandoned iron-ore mine area. We investigated the best remediation strategies to maximize arsenic removal efficiency for both soils and arsenic-containing washing solution through conducting a series of batch experiments. Based on the results of a sequential extraction procedure, most arsenic prevails in Fe-As precipitates or coprecipitates, and iron exists mostly in the crystalline forms of iron oxide. Soil washing by use of a single agent was not effective in remediating arsenic-contaminated soils because arsenic extractions determined by the Korean standard test (KST) methods for washed soils were not lower than 6mg kg(-1) in all experimental conditions. The results of X-ray diffraction (XRD) indicated that iron-ore fines produced mobile colloids through coagulation and flocculation in water contacting the soils, containing dissolved arsenic and fine particles of ferric arsenate-coprecipitated silicate. The first washing step using 0.2M HCl was mostly effective in increasing the cationic hydrolysis of amorphous ferrihydrite, inducing high removal of arsenic. Thus, the removal step of arsenic-containing flocs can lower arsenic extractions (KST methods) of washed soils. Among several washing trials, alternative sequential washing using 0.2M HCl followed by 1M HCl (second step) and 1M NaOH solution (third step) showed reliable and lower values of arsenic extractions (KST methods) of washed soils. This washing method can satisfy the arsenic regulation of washed soil for reuse or safe disposal application. The kinetic data of washing tests revealed that dissolved arsenic was easily readsorbed into remaining soils at a low pH. This result might have occurred due to dominant species of positively charged crystalline iron oxides characterized through the sequential extraction procedure. However, alkaline extraction using NaOH was effective in removing arsenic readsorbed onto the surface of crystalline minerals. This is because of the ligand displacement reaction of hydroxyl ions with arsenic species and high pH conditions that can prevent readsorption of arsenic. 相似文献