首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   13篇
  免费   0篇
环保管理   1篇
综合类   1篇
基础理论   4篇
污染及防治   4篇
评价与监测   3篇
  2011年   1篇
  2009年   1篇
  2008年   1篇
  2007年   1篇
  2006年   2篇
  2003年   1篇
  2001年   1篇
  2000年   1篇
  1998年   1篇
  1988年   1篇
  1978年   1篇
  1976年   1篇
排序方式: 共有13条查询结果,搜索用时 390 毫秒
1.
Wild rodents were collected using live snap traps in pistachio gardens of Kerman Province, Southeast Iran from 2007 to 2009, then some physiological parameters of them were measured. The samples were identified as follow: Nesokia indica, Meriones persicus, Meriones lybicus and Tatera indica. Blood samples were obtained from the heart, then the blood parameters (glucose, cholesterol, triglyceride, total protein, HDL, red and white blood cell number) in wild species of rodents and laboratory rat were compared. The results showed that there were no significant differences in serum glucose, triglyceride, HDL and total protein levels among different experimental groups. The concentration of cholesterol in T. indica was more than that in N. indica (P < 0.01). The total numbers of red blood cells also showed significant difference between wild garden rodent species and laboratory rat (P < 0.01), while the numbers of white blood cells showed no significant difference.  相似文献   
2.
3.
Acanthonus armatus Günther (family Ophidiidae) is a slightly negatively buoyant (mean weight in surface seawater =0.58% of air weight) benthopelagic fish without a swimbladder that has reduced tissues and components (muscle, bone, brain, gills, lipids) and a massive head. This species has an enlarged cranial cavity (10% of head volume) filled, except for the very small brain, with a low-density (specific gravity 1.008) fluid. The fluid provided static lift of about 0.30 g each for 4 specimens whose weights in water ranged from 1.0 to 2.6 g. Osmotic concentrations of the cranial fluid averaged 294 mOsm 1-1 in 4 specimens and , in 2 specimens for which comparisons were possible, were 43 to 45% lower than the concentrations of the plasma and perivisceral fluid. Similarly, Na+ and K+ concentrations of the cranial fluid were lower than those of the plasma or perivisceral fluid. A. armatus has highly reduced heavy tissues and an increased content of dilute fluid, with a localization of even more highly dilute fluid in the enlarged cranium which partially offsets the relatively dense tissues of the head. Information on the morphology, behavior and ecology of the fish supports the interpretation of the buoyancy and chemical data. The conclusion is consistent with the hypothesis that obtaining and conserving energy and reducing predation are the important selective factors affecting the evolution of deep-sea fishes and that these factors have greatly influenced the chemical composition of the fishes.  相似文献   
4.
Janbey A  Clark W  Noordally E  Grimes S  Tahir S 《Chemosphere》2003,52(6):1041-1046
Using a bench-scale rig, the activities of Pt, Pd and Pt+Pd catalysts supported on gamma-Al(2)O(3) and on TiO(2) (anatase) for the complete oxidation of methane (300 ppmv) in air have been measured as a function of temperature; values of T(10), T(50) and T(90) together with the Arrhenius parameters (activation energy and pre-exponential factor) are reported. Pt is less active than Pd when deposited on the surface of the TiO(2), but more active when deposited on gamma-Al(2)O(3), however when combined, the Pt+Pd mixture is more active than either metal individually. The T(10) for Pt+Pd/gamma-Al(2)O(3) was being as low as 228 degrees C. The significance of the Arrhenius parameters, for metal containing catalysts is that they exhibit compensation with increasing activation energy, while securing a more rapid increase in conversion from 0% to 100% when the temperature is increased.  相似文献   
5.
The regeneration of chromium (VI) and the recovery of etched copper from chromium etching solutions by electrodialysis is improved by the addition of a concentrator cell in the catholyte chamber. The concentrator media used are ion-exchange resins or activated carbon cloth. The maximum percentages for the regeneration of chromium and recovery of copper in these systems is however less than 80% and 90% respectively because of the competition between the processes of oxidation of Cr(III) and electrodeposition of copper. A novel combination of electrolysis with electrodialysis and concentrator cell technology is developed that achieves 92% chromium regeneration and 90% copper recovery.  相似文献   
6.
This paper describes the application of magnetoelastic sensors for quantifying the size and deposition rate of sediment samples in costal areas, lakes, and rivers. The magnetoelastic sensor, which is made of inexpensive amorphous ferromagnetic alloy, measures parameters of interest by tracking the changes in its resonant frequency and/or amplitude. Since an increase in mass loading on the sensor surface changes its resonant frequency and amplitude, the deposition rate of sediment particles can be determined in real time by tracking these two quantities. Based on a theoretical model, the size distribution of the sediment particles was also estimated from the deposition rate.  相似文献   
7.
Stabilizing phosphorus (P) in poultry waste to reduce P losses from manured soils is important to protect surface waters, while pathogens in manures are an emerging issue. This study was conducted to evaluate CaO and Ca(OH)2 for killing manure bacterial populations (pathogens) and stabilizing P in poultry wastes and to investigate the influence on soils following amendment with the treated wastes. Layer manure and broiler litter varying in moisture content were treated with CaO and Ca(OH)2 at rates of 2.5, 5, 10, and 15% by weight. All treated wastes were analyzed for microbial plate counts, pH, and water-soluble phosphorus (WSP), while a few selected layer manures were analyzed by phosphorus X-ray absorption near edge structure (XANES). A loamy sand and a silt loam were amended with broiler litter and layer manure treated with CaO at rates of 0, 2.5, 5, 10, and 15% and soil WSP and pH were measured at times 1, 8, and 29 d. Liming reduced bacterial populations, with greater rates of lime leading to greater reductions; for example 10% CaO applied to 20% solids broiler litter reduced the plate counts from 793,000 to 6500 mL-1. Liming also reduced the WSP in the manures by over 90% in all cases where at least 10% CaO was added. Liming the manures also reduced WSP in soils immediately following application and raised soil pH. The liming process used successfully reduced plate counts and concerns about P losses in runoff following land application of these limed products due to decreased WSP.  相似文献   
8.
Bones contain the majority of body lipid in some marine fish. In the sheepshead wrasse Pimelometopon pulchrum and the sablefish Anoplopoma fimbria, the bone lipid comprised 79 to 93% and 52 to 82% of the total body lipid, respectively. The senorita Oxyjulus california, another species of wrasse, has only 14% of its body lipid in bone. To determine whether dietary lipid is deposited quickly in the bone lipid, three species of fish were fed 1-14C-palmitic acid. Radioactivity appeared in the bone lipid as soon as 12 h after feeding, with the species rich in bone lipid incorporating the highest activity relative to the flesh. Roughly 80% of the radioactivity recovered in A. fimbria bone lipid was found in triglyceride. Radioactivity was equally distributed between phospholipid and triglyceride in P. pulchrum bone lipids. The results suggest that in some marine fish the bones contain the majority of the organism's reserve energy.  相似文献   
9.
This paper presents a wireless, passive, remote query CO2 sensor comprising a ribbon-like magnetoelastic thick-film coated with a mass-changing CO2 responsive polymer synthesized from acrylamide and isooctylacrylate. In response to a magnetic field impulse, the magnetostrictive magnetoelastic sensor vibrates at a characteristic resonant frequency that is inversely dependent upon the mass of the attached CO2 responsive polymer. The mechanical vibrations of the magnetostrictive sensor launch magnetic flux, which can be detected remotely using a pickup coil. By monitoring the resonant frequency of the passive sensor, the atmospheric CO2 concentration can be determined without the need for physical connections to the sensor or specific alignment requirements. The effect of humidity and the CO2 responsive copolymer composition on the measurement sensitivity are reported. Greatest sensitivity is achieved with a polymer comprising a 1:1 mole ratio of acrylamide to isooctyl acrylate. A 0.7% change in atmospheric CO2 concentration can be detected for a 20 microns thick polymer coated sensor.  相似文献   
10.
In the Mid-Atlantic Bight, conger eels (Conger oceanicus) occur from the coastal portions of estuaries to the edge of the continental shelf. In deeper waters they occupy burrows of the tilefish (Lopholatilus chamaeleonticeps). Between 1972 and 1974 we examined the stomachs and intestines of conger eels from inshore New Jersey (USA) waters (n=35, with a total length: TL of 21 to 49 cm) and between 1980 and 1983 offshore (n=295, 50 to 125 cm TL)_collections. Eels from both areas fed primarily on decapod crustaceans and fish. The specific identity of prey items within these groups generally differed from inshore to offshore areas, probably reflecting the differences in prey availability. Foods of specimens collected offshore varied with size: smaller eels (<80 cm TL) fed most heavily on decapod crustaceans, whereas larger eels (>80 cm) consumed more fishes. The presence of some nocturnally active prey items in the gut, primarily the eel Lepophidium cervinum, suggests that conger eels are nocturnal feeders. This is supported by in situ observations that conger eels are present in some tilefish burrows during the day and are presumably out of burrows and foraging at night.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号