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81.
Jeffrey H. Gove Stephen E. Fairweather Dale S. Solomon 《Environmental and Ecological Statistics》1994,1(2):109-120
Two mathematical programming formulations are presented which allow the determination of diameter distributions that maximize
the diameter class diversity in uneven-aged northern hardwood stands. Distributions generated from these models were found
to be comparable from a management standpoint and could be incorporated into existing linear programming models as alternative
management scenarios. The models presented here provide an initial framework for quantitatively addressing the requirements
of the US National Forest Management Act in matters of diversity in the planning process. 相似文献
82.
The hawksbill marine turtle (Eretmochelys imbricata) is listed on the IUCN Red List as critically endangered but little is known about its demography to support robust diagnosis
of population trends. Moreover, adult female hawksbills do not nest each year due to environmentally mediated physiological
constraints and this skipped breeding behaviour presents a major challenge in data collection and for estimating demographic
parameters from such data sets. We estimated demographic parameters such as survival and breeding probabilities for a major
Indo-Pacific nesting hawksbill population using a capture-mark-recapture (CMR) study and a multistate open robust design statistical
modelling approach, which accounts for breeding omission and the staggered arrival and departure of nesters during each season.
Our study used CMR histories for 413 nesting hawksbills tagged on Varanus Island (Western Australia) over a 4-month sampling
period each year for 20 austral summer nesting seasons between 1987 and 2007. The estimated annual survival probability for
these nesting hawksbills was constant over the 20 years at ca. 0.947 (95% CI: 0.91–0.97), which is encouragingly high for
a population associated with industry. The estimated annual conditional nesting (breeding) probability for female hawksbills
that had skipped the previous nesting season was time-specific ranging from 0.07 to 0.29 (mean = 0.18, CV = 41.3%), which
presumably reflects the interaction between turtle physiology and in-water habitat quality. The mean conditional probability
of breeding again having skipped 2 prior consecutive nesting seasons was ca. 0.83 (95% CI: 0.73–0.89), indicating a high frequency
of breeding season omission. The annual nesting probability for females that had nested the previous season was 0, reflecting
known obligate skipped breeding (reproductive omission) that is characteristic of hawksbill populations in response to high
energy demands of vitellogenesis and breeding migration. These are the first estimates of annual survival and state-dependent
breeding probabilities for any Indo-Pacific hawksbill stock that provide a basis for developing a better understanding of
regional population dynamics for this critically endangered species. 相似文献
83.
Akam Darlington Owolabi Oluwasegun Nathaniel Solomon Prince 《Environmental science and pollution research international》2021,28(46):65300-65312
Environmental Science and Pollution Research - There are numerous studies on the linkage between renewable energy and environmental sustainability. These studies have tried to show how renewable... 相似文献
84.
Wai-Chuen Ng F. C. C. Leung Solomon T. C. Chak G. Slingsby Gray A. Williams 《Marine Biology》2010,157(2):325-337
Variations in the relative contributions of gene flow and spatial and temporal variation in recruitment are considered the
major determinants of population genetic structure in marine organisms. Such variation can be assessed through repeated measures
of the genetic structure of a species over time. To test the relative importance of these two phenomena, temporal variation
in genetic composition was measured in the limpet Cellana grata, among four annual cohorts over 10 years at four rocky shores in Hong Kong. A total of 408 limpets, comprising individuals
from 1998, 1999, 2006 and 2007 cohorts were screened for genetic variation using five microsatellite loci. Minor but significant
genetic differentiation was detected among samples from the 1998/1999 collection (F
ST = 0.0023), but there was no significant differentiation among the 2006/2007 collection (F
ST = 0.0008). Partitioning of genetic variation among shores was also significant in 1998/1999 but not in the 2006/2007 collection,
although there was no correlation between genetic and geographic distances. There was no significant difference between collections
made in 1998/1999 and 2006/2007. This lack of clear structure implies a high level of gene flow, but differentiation with
time may be the result of stochastic recruitment variation among shores. Estimates of effective population size were not high
(599, 95% C.L. 352–11397), suggesting the potential susceptibility of the populations to genetic drift, although a significant
bottleneck effect was not detected. These findings indicate that genetic structuring between populations of C. grata in space and time may result from spatio-temporal variation in recruitment, but the potential development of biologically
significant differentiation is suppressed by a lack of consistency in recruitment variability and high connectivity among
shores. 相似文献
85.
Olugbenga Solomon Bello Mohd Azmier Ahmad Norhidayah Ahmad 《Chemistry and Ecology》2013,29(2):153-167
Chemically prepared activated carbon derived from banana stalk (BSAC) was used as an adsorbent to remove malachite green (MG) dye from aqueous solution. BSAC was characterised using thermogravimetric analyser, Brunauer Emmett Teller, Fourier transform infrared spectrometry, scanning electron microscopy, pHpzc, elemental analysis and Boehm titration. The effectiveness of BSAC in adsorbing MG dye was studied as a function of pH, contact time, temperature, initial dye concentration and repeated desorption–adsorption processes. pHpzc of BSAC was 4.5 and maximum dye adsorption occurred at pH 8.0. The rate of dye adsorption by BSAC was very fast initially, attaining equilibrium within 120 min following a pseudo-second-order kinetic model. Experimental data were analysed by Langmuir, Freundlich and Dubinin–Raduschevich isotherms. Equilibrium data fitted best into the Langmuir model, with a maximum adsorption capacity of 141.76 mg·g?1. Δ G 0 values were negative, indicating that the process of MG dye adsorption onto BSAC was spontaneous. The positive values of Δ H 0 and Δ S 0 suggests that the process of dye adsorption was endothermic. The regeneration efficiency of spent BSAC was studied using 0.5 M HCl, and was found to be in the range of 90.22–95.16% after four cycles. This adsorbent was found to be both effective and viable for the removal of MG dye from aqueous solution. 相似文献
86.
Research has shown that one of the best predictors of a driver's future crash risk is the number of prior moving traffic violations (e.g., speeding). Public driver records are used by government and nongovernment users to assess drivers' future crash risks. However, the adequacy of such records may be compromised by deficient recordkeeping systems and by court-based diversion programs (e.g., probation before judgment, traffic school election) that allow drivers presumed guilty to avoid convictions in court and posting of the violations to their driver records. Using a case study approach in four jurisdictions in three states, citations issued for traffic violations were tracked through court adjudication to placement on driver records. Individual court case records and driver history records were reviewed. The percentages of citations issued that appeared on driver records were 58-87% for moving violations, 30-94% for driving while impaired (DWI), and 67-95% for occupant restraint violations. Diversion programs were a significant factor in two states, where 21% and 35% of moving violation citations resulted in diversions. Almost all court convictions in each jurisdiction were recorded on driver records, but few citations resulting in diversions were recorded. Thus, diversion programs in some jurisdictions substantially reduce the utility of public driver records as reliable indicators of prior traffic violations and future crash risks. Recordkeeping inefficiencies and errors were less important factors in this study. 相似文献
87.
Problem: Nearly 700,000 police-reported motor vehicle crashes occur annually at stop signs, and approximately one-third of these crashes involve injuries. The purpose of this study was to develop a better understanding of the crashes that occur at stop signs and to identify potential countermeasures. Method: Police reports of crashes at stop sign-controlled intersections during 1996–2000 in four U.S. cities were examined in detail. At total of 1,788 crash reports for intersections with two-way stop signs were included in the study. Results: Stop sign violations accounted for about 70% of all crashes. Typically these crashes were angular collisions. Among crashes not involving stop violations, rear-end crashes were most common, accounting for about 12% of all crashes. Stop sign violation crashes were classified into several subtypes — driver stopped, driver did not stop, snow/wet/ice, and other/unknown. In about two-thirds of stop sign violation crashes, drivers said they had first come to a stop. In these cases, inability or failure to see approaching traffic often was cited as the cause of the crash. Drivers younger than 18 as well as drivers 65 and older were disproportionately found to be at fault in crashes at stop signs. Impact on industry: Potential countermeasures include changing traffic control and intersection design, improving intersection sight distance, and increasing conspicuity of stop signs through supplemental pavement markings and other devices. 相似文献
88.
The Roles of Photooxidation and Biodegradation in Long-term Weathering of Crude and Heavy Fuel Oils 总被引:1,自引:0,他引:1
Roger C Prince Robert M GarrettRichard E Bare Matthew J GrossmanTodd Townsend Joseph M SuflitaKenneth Lee Edward H OwensGary A Sergy Joan F BraddockJon E Lindstrom Richard R Lessard 《Spill Science & Technology Bulletin》2003,8(2):145-156
Although spilled oil is subject to a range of natural processes, only combustion, photooxidation and biodegradation destroy hydrocarbons and remove them from the biosphere. We present laboratory data that demonstrate the molecular preferences of these processes, and then examine some oil residues collected from previously documented releases to confirm the important roles that these processes play in removing spilled oil from both marine and terrestrial environments. 相似文献
89.
Kenneth Lee Gary WohlgeschaffenGilles H Tremblay B Thomas Johnson Roger C Prince Chantal C Guénette Edward H Owens 《Spill Science & Technology Bulletin》2003,8(3):273-284
Changes in the toxicity levels of beach sediment, nearshore water, and bottom sediment samples were monitored with the Microtox® Test to evaluate the two in situ oil spill treatment options of natural attenuation (natural recovery--no treatment) and sediment relocation (surf washing). During a series of field trials, IF-30 fuel oil was intentionally sprayed onto the surface of three mixed sediment (pebble and sand) beaches on the island of Spitsbergen, Svalbard, Norway (78°56′ N, 16°45′ E). At a low wave-energy site (Site 1 with a 3-km wind fetch), where oil was stranded within the zone of normal wave action, residual oil concentrations and beach sediment toxicity levels were significantly reduced by both options in less than five days. At Site 3, a higher wave-energy site with a 40-km wind fetch, oil was intentionally stranded on the beach face in the upper intertidal/supratidal zones, above the level of normal wave activity. At this site under these experimental conditions, sediment relocation was effective in accelerating the removal of the oil from the sediments and reducing the Microtox® Test toxicity response to background levels. In the untreated (natural attenuation) plot at this site, the fraction of residual oil remaining within the beach sediments after one year (70%) continued to generate a toxic response. Chemical and toxicological analyses of nearshore sediment and sediment-trap samples at both sites confirmed that oil and suspended mineral fines were effectively dispersed into the surrounding environment by the in situ treatments. In terms of secondary potential detrimental effects from the release of stranded oil from the beaches, the toxicity level (Microtox® Test) of adjacent nearshore sediment samples did not exceed the Canadian regulatory limit for dredged spoils destined for ocean disposal. 相似文献
90.
S. I. Solomon E. Basso C. Osorio H. Melo de Moraes A. Serrano 《Journal of the American Water Resources Association》1986,22(2):209-217
ABSTRACT: The construction of the Tucurui Hydroelectric Plant on the Tocantins River basin in Brazil requires flood forecasting for ensuring the safety of the cofferdam. The latter has been initially designed for a flood with a return frequency of one in 25 years. Lack of adequate forecasting facilities during the earlier stages of construction has resulted in significant damages and construction delays. Statistical forecasting models were developed by Projeto de Hidrologiay Climatologie da Amazonia (PHCA) for the purpose of preventing further damages at the site. These models are currently in use and are the subject of this paper. The application of these models during the 1980 flood season, when the highest flood on record occurred at the Tucurui site, proved of great assistance in preventing the flooding of the cofferdam. In conjunction with the development of these models a number of data collection platforms using data transmission through the GOES system were installed to provide automatically the data required for forecasting. 相似文献