998 resultados para ddc: 658.3124
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Populations of kilka in the Caspian Sea have important role in the food chain. This study was conducted to determine population parameters of three species of kilka in the south of the Caspian Sea, during 2006-2007. Mean length was 102.4±9.7 mm for common kilka, 117.8±6.9 mm for anchovy and 119.5±10.9 mm for bigeye. The relationship between length and weight indicated the negative allometric growth in the all three species. Mean age for common kilka, anchovy and bigeye were 3.6, 4.6 and 4.6 years, respectively. Sex ratio (M:F) were 0.52:1 for anchovy, 0.60:1 for common kilka and 1.60:1 for bigeye. The value of growth coefficient (K) was the highest (0.321) for the common kilka, (0.267) for the bigeye, and the lowest for the anchovy kilka (0.245). Total mortality estimated from the descending of the catch curve using the age structure, Z=1.280 yr-1 for common kilka, Z=1.067 yr-1 for anchovy, and Z=1.015 yr-1 for bigeye. Natural mortality (M) were estimated using Pauly formula as M=0.622, M=0.537 and M=0.503 per year for common kilka, bigeye and anchovy, respectively. Value of fishing mortality (F) were estimated from Z and M, as F=0.658 for common kilka, F=0.564 for anchovy and F=0.478 for bigeye. The exploitation rate (E) were estimated E=0.514 for common kilka, E=0.528 for anchovy and E= 0.471 for bigeye. The estimate of MCY (Maximum Constant Yield) was calculated using the more reliable time series of commercial catch data from 2001-2007, which resulted in an estimate of MCY for the kilka fishery of 14100 tonnes.
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Bream (Abramis brava orientalis) is one of Cyprindae the Caspian Sea and its basin which has a special ecological, biological and economical role. Stock of this fish in the Caspian Sea has reduced during several years for different reason the over fishing, different industrial, agriculture, urban pollution and destroy of the spawning habitat. So that fishery company decided to recover the stock of this fish by the way of artificial reproduction of a Bream couple hunted from south coast of the Caspian Sea (Iran) and setting the fingerling to the rivers and inflow wetlands of the Caspian Sea.This activity has due to 20 tons Bream annual fishing in the Iranian South coast of the Caspian Sea (Gilan province coast and Anzali wetland), The artificial reproduction has decreased Bream population diversity of Caspian sea and Anzali wetland.So it has been declined to improve Braem population diversity by the entrance of Azerbijan republic Bream and encounter to the Caspian sea Bream. Meanwhile there is Bream in the Aras Dam Lake which had been forgotten by the Fishery Company of Iran .For this reason specifications morphometric, meristic and inter species Molecular Genetic have been surveyed in Anzali wetland,Southern coast of Caspian Sea ,Aras Darn Lake and Azerbijan republic during 2003-2005. According to the research on specifications of Morphometric and Meristic of Anzali wetland(120 species),Southern coast of Caspian Sea(90 species), Aras Dam Lake(110 species) and Azerbijan Republic(125 species)has Morphometric and Meristic differences. So that average weight and total length of Anzali wetland Bream respectively was 167 g and 23/76 cm, 102 g and 27/62 cm in Caspian Sea , 461 g and 3 5/38 cm in Aras Darn Lake and 3 4189 g and 15/21 cm in Azerbijan republic (We forced to use 1 year Bream of artificial reproduction in Iran). Also variation coefficient average Morphometric, Morphometric specification Ration and meristic in Anzali wetland Bream was 17/45, 21/56 and 4/63, in Caspian Sea bream 22/58, 15/27 and 3124, in Aras Dam lake Lake 17145. 1.5/27 and 3/57 and Azerbaijan republic Bream 22/29, 19/66 and 4/22. Also Bream of these four regions in general status had Morphometric significant differences based on One Way ANOVA Analysis. Meanwhile Anzali wetland Bream with Caspian Sea Bream from 41 Morphometric surveyed factors in 33 factors, with Aras Darn Lake Bream in 41 factors, with Azerbkjan republic Bream in 41 factors,Caspian Sea Bream with Aras Darn Lake Bream in 36 factors,with Azerbijan republic B ream in 40 factors and A ras Dam L ake Bream with Azerbijan republic Bream in 38 factors had significant statistical differences. These four regions Bream had differences according to the Morphomertric specification ration based on One Way ANOVA Analysis. Also Anzali wetland Bream was surveyed with Caspian Sea Bream from 37 factors i n 27 factors, Anzali wetland Bream with Aras Dam 1ake in 37 factors Anzali wetland Bream with Azerbijan republic Bream in 32 factors,Caspian sea bream with Arsa Dam Lake Bream in 26 factors, Caspian Sea Bream with Azerbijan republic Bream in 29 factors and Aras Dam Lake Bream with Azerbijan republic Bream in 34 factor had significant statistical differences. Based on Meristic factor of four regions bream in 16 surveyed factors in 10 factors had meaningful differences according to the One Way ANOVA Analysis. While Anzali wetland Bream was surveyed with Caspian Sea Bream from in 3 factors,Anzali wetland Bream with Aras Dam lake in 8 factors,Anzali wetland Bream with Azerbijan republic B ream in 6 factors,Caspian Sea bream with Arsa Dam Lake Bream in 6 factors,Caspian sea Bream with Azerbijan republic Bream in 3 factors and Aras Dam Lake Bream with Azerijan republic Bream in 8 factor had significant statistical differences.Meanwihle based on Factor Analysis and Discriminant Breams had differences. Also according to the resrarchs Anzali wetland Bream in 0+ age group till 5+ (6 age groups),Caspian Sea bream in 1+ - 5+(5 age groups),Aras Darn Lake Bream in 1+ - 7+ (7 age groups) and Azerbijan republic Bream for Morphometric and Meristic studies in 1+age group and for molecular Genetic reaserch were in 8+and 9+ age groups. According to the research 4 ecosystems Bream in status of same age, Aras lake Bream were bigger according to weight and length.Also in this research genetic diversity between four population was researched by PCR-RFLP technic on a piece of mitochondrion genome with the length of 3500bp contain of tRNA-leu,tRNA-glu,ND5/6,Cytb. Between 17 used enzyme. 4 enzyme, Dral, Bc11, Haefll and Banff showed diversity in totally 6 composite haplotype was detected. Maximum nucleotide diversity by the value% 0/58 in Azerbijan republic Bream by all haplotype. Aras darn Lake Bream had 2 haplotype and nucleotide diversity of %0/35.Anzali wetland and Caspian Sea Bream had no diversity. Statistical analysis by the usage of Monte Carlo with 1000 repeat showed significant differences between Azerbaijan Bream and other Bream(P<0/0001) but there was no significant difference between 3 regions Bream(P>0/5).
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This study examines the kinetics of carbonation by CO2 at temperatures of ca. 750 °C of a synthetic sorbent composed of 15 wt% mayenite (Ca12Al14O33) and CaO, designated HA-85-850, and draws comparisons with the carbonation of a calcined limestone. In-situ XRD has verified the inertness of mayenite, which neither interacts with the active CaO nor does it significantly alter the CaO carbonation–calcination equilibrium. An overlapping grain model was developed to predict the rate and extent of carbonation of HA-85-850 and limestone. In the model, the initial microstructure of the sorbent was defined by a discretised grain size distribution, assuming spherical grains. The initial input to the model – the size distribution of grains – was a fitted parameter, which was in good agreement with measurements made with mercury porosimetry and by the analysis of SEM images of sectioned particles. It was found that the randomly overlapping spherical grain assumption offered great simplicity to the model, despite its approximation to the actual porous structure within a particle. The model was able to predict the performance of the materials well and, particularly, was able to account for changes in rate and extent of reaction as the structure evolved after various numbers of cycles of calcination and carbonation.
Resumo:
This study examines the kinetics of carbonation by CO 2 at temperatures of ca. 750°C of a synthetic sorbent composed of 15wt% mayenite (Ca 12Al 14O 33) and CaO, designated HA-85-850, and draws comparisons with the carbonation of a calcined limestone. In-situ XRD has verified the inertness of mayenite, which neither interacts with the active CaO nor does it significantly alter the CaO carbonation-calcination equilibrium. An overlapping grain model was developed to predict the rate and extent of carbonation of HA-85-850 and limestone. In the model, the initial microstructure of the sorbent was defined by a discretised grain size distribution, assuming spherical grains. The initial input to the model - the size distribution of grains - was a fitted parameter, which was in good agreement with measurements made with mercury porosimetry and by the analysis of SEM images of sectioned particles. It was found that the randomly overlapping spherical grain assumption offered great simplicity to the model, despite its approximation to the actual porous structure within a particle. The model was able to predict the performance of the materials well and, particularly, was able to account for changes in rate and extent of reaction as the structure evolved after various numbers of cycles of calcination and carbonation. © 2011 Elsevier Ltd.
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于2005年10月对香溪河干流5个小水电站对河流底栖动物的影响进行调查研究,按影响情况,各电站设5个采样点。应用底栖动物物种组成、现存量、优势类群、功能摄食类群等参数,衡量小水电站对河流底栖动物群落结构的影响。在研究区域共采集到底栖动物4656条,平均密度为658 ind./m2,蜉蝣目的四节蜉属(Baetisspp.)是该区域的优势类群。研究结果表明:电站的修建对河流水化学指标没有显著影响,但河流生境的物理因子(如流速和水深)都发生了较大的改变;对河流底栖动物的各方面均有一定的影响,特别是密度在5个样点
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根据噶氏斑纹和雄性个体的副性征,对我国的鳅属鱼类进行了分类整理。一直被作为中华鳅Cobitissinensis Sauvageet Dabry,1874同物异名的长吻鳅C.dolichor hynchus Nichols,1918和稀有鳅C.rarusChen,1981不仅在噶氏斑纹上存在差异,而且它们雄性个体的副性征也明显有别,为有效种;而1925年Nichols命名的花斑鳅C.melanoleuca Nichols,1925与北方鳅C.granoeiRendahl,1935或中华鳅不同,也为有效种。因
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国家自然科学基金 3 9670 1 0 1、4 983 2 0 1 0资助
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国家杰出青年科学基金(3992 50 0 7); 欧盟国际合作项目(ERBIC 1 8CT 960 0 59)
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在人工诱导的复合三倍体鲤鱼成熟个体中有极个别个体产出的卵既保留了原有的3套染色体,又能与一套外来精核融合产生四倍体。1997年人工产生的8000多尾鲤鲫四倍体鱼经细胞遗传学研究分析鉴定,结果所有的个体都有4套染色体组,染色体数目在185~210之间,众数为200,四倍体比率为100%。这表明人工复合三倍体鲤鱼的生殖方式十分独特,绝大部分个体的成熟卵可借助于外来精子的激动进行自然雌核发育;而有极个别个体的成熟卵能与外来精子融合产生四倍体个体。四倍体鲤鲫的形态特征像鲫鱼。