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971.
采用BAF+过滤处理炼油污水,CODcr石油类、氨氮、SS去除率可以达到51.8%、62.8%、75%、100%,在BAF进水指标符合GB8978—1996污水综合排放标准一级标准,处理后出水指标可以达到CODcr≯55mg/L,Oil≯2m/L,NH3-N≯5mg/L,SS≯1mg/L,达到中石化循环水补充水标准。  相似文献   
972.
The Uralide orogen, in Central Russia, is the focus of intense geoscientific investigations during recent years. The international research is motivated by some unusual lithospheric features compared with other collisional belts including the preservation of (a) a collisional architecture with an orogenic root and a crustal thickness of 55–58 km, and (b) large volumes of very low-grade and non-metamorphic oceanic crust and island arc rocks in the upper crust of a low–relief mountain belt. The latter cause anomalous gravity highs along the thickened crust and the isostatic equilibrium inside the Uralides lithosphere as well as the overthrust high-metamorphic rocks. The integrated URSEIS '95 seismic experiment provides fundamentally new data revealing the lithospheric architecture of an intact Paleozoic collisional orogen that allows the construction of density models. In the Urals' lithosphere different velocity structures resolved by wide-angle seismic experiments along both the URSEIS '95- and the Troitsk profile. They can be used to constrain lithospheric density models: a first model consists of a deep subducted continental lower crust which has been highly eclogitized at depths of 60–90 km to a density of 3550 kg/m3. The second model shows a slightly eclogitized lower crust underlying the Uralide orogen with a crustal thickness of 60 km. The eclogitized lower crust causes a too-small impedance contrast to the lithospheric mantle resulting in a lack of reflectors in the area of the largest crustal thickness. Both models fit the measured gravity field. Analyzing the isostatic state of the southern Urals' lithosphere, both density models are in isostatic equilibrium.  相似文献   
973.
We studied the effect of the abundance of predatory fishes and structural complexity of algal assemblages on the survival of juveniles of the sea urchin Paracentrotus lividus on Mediterranean infralittoral rocky bottoms. Post-settlement juveniles (2–10 mm) were placed on four distinct natural substrates with increasing structural complexity (coralline barren, algal turf, erect fleshy algal assemblages and small crevices) inside and outside the Medes Islands Marine Reserve. Predation on these sea urchins increased at greater abundance of predatory fishes, and decreased with greater structural complexity. The refuge provided by structural complexity, however, decreased with increasing size of sea urchin recruits. Predation on the smallest post-settlers was carried out almost exclusively by small fishes (<20 cm), mainly the labrid Coris julis, while the dominant predator of larger juveniles was the sparid Diplodus sargus. Our results demonstrate the cascading effects caused by the prohibition of fishing in marine reserves, and highlight the potential role of small predatory fishes in the control of sea urchin populations.Communicated by O. Kinne, Oldendorf/Luhe  相似文献   
974.
Typhloscolecid polychaetes, assigned to the genera Typhloscolex (Typhloscolex muelleri) and Travisiopsis (Travisiopsis dubia), feeding on chaetognaths are reported for the first time from the Indian Ocean. These parasitic/predatory polychaetes cause decapitation in the chaetognath Flacisagitta enflata, either by eating the head or by causing injuries to the neck or body. Data from eastern Africa to western India showed a peak of polychaete infestation and decapitation of F. enflata in the Seychelles. A 5% peak occurrence (turnover rate is unknown) of decapitated individuals indicates that this parasitism/predation may have an important impact on local F. enflata populations. The harpacticoid copepod Microsetella norwegica was found feeding on the head and the reproductive organs of F. enflata. Therefore, this copepod may cause both decapitation and castration. Flatworm parasites are reported from the body cavity of F. enflata. Digeneans probably belonging to the genera Aphanurus, Parahemiurus, Accacladocoelium and Opechona, along with the accacoeliid Cercaria owreae and didymozoid metacercariae, were found. Cestode larvae were also recovered. No nematodes were found inside chaetognaths in this study.Communicated by O. Kinne, Oldendorf/Luhe  相似文献   
975.
An unusual pollination strategy is pollination by sexual deception in which orchids sexually attract male insects as pollinators. One gap in knowledge concerns the pattern and extent of pollinator movement among these sexually deceptive flowers and how this translates to pollen and gene flow. Our aim was to use mark and recapture techniques to investigate the behavior and movement of male Colletes cunicularius, an important bee pollinator of Ophrys. Our study site was located in northern Switzerland where a large population of the bees was nesting. Within two plots, (10×40 m), we marked bees with different colors and numbered tags. Seventeen percent of the 577 marked bees were recaptured over a period of 1 to a maximum of 11 days. However, the number of recaptures dropped dramatically after 3–5 days, suggesting an average lifetime of less than 10 days. Mark-recapture distances varied from 0 to 50 m, with a mean of 5 m. Our findings show that individual male bees patrol a specific and restricted region of the nesting area in search of mates. This mark-recapture study provides the first clues about the potential movement of pollen within populations of Ophrys orchids. We predict that orchid-pollen movements mediated by bees will be similar to the mark-recapture distances in this study. Parallel studies within orchid populations, including direct studies of pollen movement, are now required to better understand how pollinator mate-searching behavior translates to pollination success and pollen movement within sexually deceptive orchid populations.Communicated by R.F.A. Moritz  相似文献   
976.
A psychrotrophic bacterial strain, Pseudoaltermonas sp. SM9913, was isolated from deep-sea sediment collected at 1,855 m depth. Two proteases produced by Pseudoaltermonas sp. SM9913 were purified, MPC-01 and MCP-02. MCP-01 is a serine protease with a molecular weight of 60.7 kDa. It is cold-adapted with an optimum temperature of 30–35°C. Its Km and Ea for the hydrolysis of casein were 0.18% and 39.1 kJ mol–1, respectively. It had low thermostability, and its activity was reduced by 73% after incubation at 40°C for 10 min. MCP-02 is a mesophilic metalloprotease with a molecular weight of 36 kDa. Its optimum temperature for the hydrolysis of casein was 50–55°C. The Km and Ea of MCP-02 for the hydrolysis of casein were 0.36% and 59.3 kJ mol–1, respectively. MCP-02 had high thermostability, and its activity was reduced by only 30.5% after incubation at 60°C for 10 min. At low temperatures, Pseudoaltermonas sp. SM9913 mainly produced the psychrophilic protease MCP-01.Communicated by O. Kinne, Oldendorf/Luhe  相似文献   
977.
The three juvenile phases of the spiny lobster Panulirus argus (algal phase: 5-15 mm carapace length, CL; postalgal phase: 15-45 mm CL, and subadults: 45-80 mm CL) occur in the reef lagoon at Puerto Morelos, Mexico. The algal phase abounds in this lagoon, which is covered by extensive seagrass-algal meadows, but the density of postalgal and subadult juveniles is low, owing to the scarcity of crevice-type shelters suitable for these phases. The feeding ecology of the three juvenile phases was investigated to examine whether spatial or temporal differences in food intake, diet composition, or nutritional condition occurred among phases and could partially account for the low abundance of the larger juveniles. Juveniles were collected by divers at night, from January to November 1995, throughout the mid-lagoon and back-reef zones. Percent stomach fullness, relative weight of the digestive gland (RWDG, an index of nutritional condition), percent frequency of occurrence and percent volume of food categories in the diet were compared between sexes, juvenile phases, molt stages (postmolt, intermolt, premolt), seasons, and sampling zones (mid-lagoon and back-reef zones). Significant differences in stomach fullness occurred only among molt stages, mainly because postmolt individuals had emptier stomachs. The main food categories in all juvenile phases were crustaceans (mostly hermit crabs and brachyurans) and gastropods, but the food spectrum was wide, including many other animal taxa as well as plant matter. In June 1995, the epibenthic macrofauna was sampled in five sites in the lagoon that differed in their amount of vegetation. The most abundant taxa in all sites were decapods and gastropods, but density and diversity measures showed that the distribution of these potential prey taxa for juvenile P. argus was rather patchy. Diet overlap in juvenile lobsters was high between sexes, juvenile phases, sampling zones, seasons, and molting stages, indicating that all juveniles fed on the same general food categories throughout time. The only factor that affected the RWDG was the juvenile phase. RWDG was significantly lower in subadults than in algal and postalgal phases, suggesting a poorer nutritional condition in the largest juveniles. This may be related to the scarcity of suitable shelters for large juveniles throughout the lagoon, which may preclude subadults from exploiting food resources in areas of the lagoon where shelter is limited.  相似文献   
978.
Communal rearing of offspring may help mothers maximize their investment in offspring at a reduced cost to their own bodily condition, thus maximizing their potential for reproductive success. The objective of this study was to quantify the costs and benefits of communal rearing to prairie vole (Microtus ochrogaster) pups and mothers. Mothers were assigned to one of three social units: solitary mothers, singularly breeding groups (i.e. one mother and one non-reproductive sister) and plurally breeding groups (i.e. two lactating sisters). For each type of social unit, some replicates were provided with food ad libitum, while others were provided with limited food. The body mass of focal mothers (i.e. the first mother to produce a litter) was a significant predictor of pup growth. Regardless of food availability, litters of focal mothers in plurally breeding groups gained more weight than litters reared by solitary mothers. Pups reared in singularly breeding groups were intermediate in weight gain, but did not gain significantly more weight than solitary offspring. There was no difference in the body mass of focal mothers from each type of social unit, regardless of food availability. Within plurally breeding groups, the weight gain of the two litters and body mass of focal and second mothers did not differ. However, focal mothers from plurally breeding groups nursed fewer pups than solitary mothers and also fewer pups than their nestmates when food was limited. Our results suggest that plural breeding results in greater fitness to mothers than solitary and singular breeding.Communicated by E. Korpimäki  相似文献   
979.
980.
胡椒大、中量元素的含量在不同树龄中有所不同,幼龄期以氮最高,其N:P2O3:K2O:Ca:Mg为1:0.15:0.53-0.9:0.22-0.38:0.15-0.30;成年龄则以K2O最高,N:P2O3:K2O:Ca:Mg为1:0.13:1.32:0.44:0.16.在不施微肥的情况下,胡椒叶片缺B、Mo、Zn.成年龄胡椒各养分含量都是从萌芽期(收获后)开始,随生育期的进展而增加,到果实成熟期下降.一株中产胡椒N、P2O5、K2O总吸收量为282.4g,其比例为1:0.19:0.9.  相似文献   
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