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Managing household wastewater is an issue that affects hundreds of thousands of people in rural communities nationwide, many of whom rely on septic systems as their primary means of household wastewater disposal. Septic system absorption field products with architectures quite different from traditional pipe-and-gravel systems are being installed in many states with variances from initial design specifications. The objective of this study was to evaluate the performance, as measured by the in-product height of stored solution, of four differing absorption-field product architecture types in a profile-limited soil that was loaded at the maximum allowable rate based on soil morphology. Five chamber, two gravel-less pipe, two polystyrene aggregate, and four pipe-and-gravel systems were installed in a profile-limited, Captina silt loam soil (fine-silty, siliceous, active, mesic Typic Fragiudult) and dosed with raw effluent at rates determined by current State of Arkansas regulations via individual peristaltic pumps. Free-solution monitoring ports were installed within each product, where the depth to free solution was measured periodically and used to evaluate product performance. Data collected from January through August 2009 indicated that preliminary system performance was unaffected by product architecture type. All products performed similarly under dry soil conditions. However, differences among individual products were observed during periods of hydrologic stress (i.e., wet soil conditions). Surfacing of effluent was not observed atop any product, indicating that the current loading rate design method is functioning properly. Preliminary results indicate that some alternative absorption-field products perform similarly to the traditional pipe-and-gravel system, thus providing flexibility and options for homeowners. 相似文献
124.
Spectroscopic approaches for phosphorus speciation in soils and other environmental systems 总被引:1,自引:0,他引:1
In the past decades, environmental scientists have become increasingly involved in developing novel approaches for applying emerging spectroscopic techniques to complex environmental matrices. The objective of this review is to convey the most common chemical species of phosphorus reported for soils, sediments, model systems, and waste materials based on analyses by four spectroscopic techniques: X-ray absorption near-edge structure, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and Raman spectroscopy. Unique information is provided by each technique at a level of specificity that depends in part on matrix complexity. The X-ray absorption near-edge structure and nuclear magnetic resonance techniques reveal inorganic and organic P species in intact environmental matrices or in chemical extracts, whereas the Fourier transform infrared and Raman techniques can provide more specific bonding information about mineral or adsorbed P species in model analogs of matrix components. The most common P species in soils and sediments as indicated by spectroscopy are hydroxyapatite and octacalcium phosphate minerals, phosphate adsorbed on Fe- and Al-oxides, pyrophosphates and polyphosphates, phosphate mono- and di-esters, and phosphonates. Continued advancements in spectroscopic methods should improve speciation-based models of P mobilization and transformations in the environment. 相似文献
125.
New highly fluorinated monodentate and bidentate phosphine oxide compounds of the type {CF(3)(CF(2))(n)CH(2)CH(2)}(3)PO (n = 5, 9) and [{CF(3)(CF(2))(5)CH(2)CH(2)}(2)P(O)CH(2)CH(2)P(O){CH(2)CH(2)(CF(2))(5)CF(3)}] have been prepared. Their ability to extract a number of metals and radionuclides from aqueous solutions into perfluorinated solvents has been established and the extractable species investigated. All extractants extract the metals As(V), Cd(II), Co(II), Cr(VI), Hg(II), Pb(II), and Sn(II) with >75% removal. In addition, the radioisotopes (90)Sr(II), (133)Ba(II), and U(VI) have been investigated, whilst (59)Fe(III) has been used to model the extraction of plutonium. (133)Ba(II) shows a high distribution ratio for monodentate phosphine oxides, whilst for UO(2)(2+) and (59)Fe(III) bidentate phosphine oxides are superior. 相似文献
126.
Kathryn L. Van Alstyne Katie J. Anderson Amanda K. Winans Sue-Ann Gifford 《Marine Biology》2011,158(9):2087-2094
Ulvaria obscura, a prominent component of green tide blooms in Washington, is unique among macroalgae because it contains dopamine. To examine
dopamine release by U. obscura following simulated low tides, we conducted 6 field experiments in which algae were emersed for 75 min and then immersed
in filtered seawater (FSW). Dopamine was measured in algal tissues prior to emersion and 3 h after immersion and in seawater
for 3 h following immersion. In our experiments, algae released 7–100% of their tissue dopamine, resulting in average seawater
concentrations of 3–563 μM. In 5 of 6 experiments, seawater dopamine concentrations were highest immediately after immersion,
and then decreased over time. The percentages of dopamine released were not correlated with tissue dopamine concentrations,
but were positively correlated with solar radiation during emersion. The release of dopamine, which is both cytotoxic and
genotoxic, may explain the negative effects of U. obscura exudates on marine organisms. 相似文献
127.
Animals adjust their antipredator behavior according to environmental variation in risk, and to account for their ability
to respond to threats. Intrinsic factors that influence an animal’s ability to respond to predators (e.g., age, body condition)
should explain variation in antipredator behavior. For example, a juvenile might allocate more time to vigilance than an adult
because mortality as a result of predation is often high for this age class; however, the relationship between age/vulnerability
and antipredator behavior is not always clear or as predicted. We explored the influence of intrinsic factors on yellow-bellied
marmot (Marmota flaviventris) antipredator behavior using data pooled from 4 years of experiments. We hypothesized that inherently vulnerable animals
(e.g., young, males, and individuals in poor condition) would exhibit more antipredator behavior prior to and immediately
following conspecific alarm calls. As expected, males and yearlings suppressed foraging more than females and adults following
alarm call playbacks. In contrast to predictions, animals in better condition respond more than animals in below average condition.
Interestingly, these intrinsic properties did not influence baseline time budgets; animals of all ages, sexes, and condition
levels devoted comparable amounts of time to foraging prior to alarm calls. Our results support the hypothesis that inherent
differences in vulnerability influence antipredator behavior; furthermore, it appears that a crucial, but poorly acknowledged,
interaction exists between risk and state-dependence. Elevated risk may be required to reveal the workings of state-dependent
behavior, and studies of antipredator behavior in a single context may draw incomplete conclusions about age- or sex-specific
strategies. 相似文献
128.
Elizabeth A. Tibbetts Amanda Izzo Zachary Y. Huang 《Behavioral ecology and sociobiology》2011,65(5):1123-1131
Although there is increasing interest in the evolution of endocrine systems, relatively little is known about the factors
associated with natural endocrine variation in invertebrates. Here, we assess juvenile hormone (JH) titers among nest-founding
queens of the wasp Polistes dominulus over 2 years. We allowed unfamiliar wasps to battle for dominance and examined the relationships between dominance rank,
JH, ovarian development, and facial patterns. The relationship between JH-titer and dominance varied across years; there was
a stronger relationship between JH-titer and dominance in 2006 than in 2008. Across years, wasps that won dominance contests
had facial patterns with more broken black spots than wasps that lost dominance contests. There was no relationship between
dominance rank and ovarian development. The individual characteristics associated with JH-titer were also tested; JH-titers
were correlated with facial pattern brokenness and ovarian development. This study adds to previous work indicating that P. dominulus facial patterns function as a signal of fighting ability. Furthermore, the correlation between JH-titers and facial patterns
parallels previous work on testosterone and vertebrate signals and suggests that links between signals of fighting ability
and hormones that mediate fighting ability may be common across taxa. Overall, individual JH-titers vary, though they are
typically associated with factors related to individual reproductive success, including dominance, fertility, and facial pattern
brokenness. Future studies in additional contexts and taxa will be important to test how and why JH-titers vary. 相似文献
129.
de Araújo Neto Cláudio Luis Gurjão Renan Ítalo Leite Farias Amanda Paiva de Melo Márcio Camargo Monteiro Veruschka Escarião Dessoles 《Environmental science and pollution research international》2021,28(47):66819-66829
Environmental Science and Pollution Research - The properties of municipal solid waste (MSW) in landfills vary considerably, depending on the waste’s composition, time, and density. This... 相似文献
130.
Turner syndrome (TS), a common chromosomal abnormality affecting females, is associated with partial or complete loss of the second sex chromosome. Although the classic karyotype is 45, X, the detection of mosaic TS is increasing. TS is a multi-system disorder with significant endocrine, cardiovascular and reproductive impacts. Accelerated ovarian follicular loss leads to primary amenorrhoea or premature ovarian insufficiency and infertility. Early diagnosis and counselling regarding hormone replacement therapy and future reproductive capacity, including fertility preservation, are essential to improve reproductive outcomes. Pubertal induction or estrogen replacement is usually required to optimise long-term health outcomes; however, initiation may be delayed due to delayed diagnosis. Spontaneous pregnancy occurs in a small number of women; however, many require donor oocytes and assisted reproductive technology to achieve a pregnancy. Pregnancy is a high risk especially when associated with congenital heart disease. Prepregnancy counselling by the multidisciplinary team (MDT) to identify contraindications and optimise pre-existing health issues is essential. Pregnancy management should be led by a maternal-fetal medicine unit with input from the MDT. This review examines reproductive health outcomes in women with TS and how best to manage them to reduce health risks and improve maternal and neonatal outcomes. 相似文献