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1.
The contents of nearly forty-elements in surface sediments in Jiaozhou Bay were determined using a Neutron Activation Analysis Technique(Grancini,et al.,1976;Li Peiquan et al.,1985,1986;Li Xiuxia etal.,1986).This paper's detailed discussion on only nine elements(Fe,Mn,Co,Cr,Sc,As,Sb,Zn andV)includes their distributions,concentrations,correlationships,material sources,background,etc.Based on Zavaristski's classification method,Fe,Mn,Co Cr and V belong to the second group;As and Sb to theeighth groups:Sc and Zn to the third and sixth groups.It was found that their notably good correla-tionship is mainly due to the similarity of their ionic structures and that their variation is controlled by theFe content(except Mn).The source of sediments is mainly terristrial material,and the composition ofsediment is similar to that of shale and shale+clay.The contents for a large number of ele-ments are within the scope of the background level,but there still is pollution of Zn and Cr,at least in a few stations. 相似文献
2.
Cloning, expressing, and hemolysis of tdh, trh and tlh genes of Vibrio parahaemolyticus 总被引：1，自引：0，他引：1
Vibrio parahaemolyticus (VP) is one of the pathogenic vibrios endangering net-cage cultured Pseudosciaena crocea,Fennerpenaeus chinensis, and shellfish in coastal areas of China. Several types of hemolysins produced by Vp have been characterized as major virulence factors.They are thermostable direct hemolysin (TDH),TDH-related hemolysin (TRH) and thermolabile hemolysin (TLH). In this study, we cloned tdh, trh, and tlh genes from the genome DNA of VP by polymerase chain reaction (PCR).We ligated the three genes into prokaryotic expression vector pET-28a (+),and transformed the recombinant plasmids into Es-cherichia coli BL21 (DE3). The expression of recombinant proteins was induced by isopropyl-β-D-thiogalacto-pyranoside (IPTG). The recombinant proteins were expressed in a form of inclusion bodies and thus purified with Ni-NTA affinity chromatography. Western blotting results showed that recombinant proteins,TDH, TRH and TLH, could be recognized by rabbit anti-VP serum. The three purified proteins were renatured by gradient dialysis.The renatured proteins exhibited hemolytic activity except for TLH in the presence of phosphatidylcholine. These results not only are helpful for better understanding these genes’ functions under a single factor level, but also provide evidence for VP vaccine engineering. 相似文献
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4.
Monthly investigations were mae on the population of Chinese freshwater crab,Sinopotamon yangtsekiense Bott, 1967 from April, 1984 to March, 1985. The data on 4413 specimens show that the growth was affected mainly by temperature.
During the April to November growth period, the crabs' major development occurred from June through October. One year was
required for a fine white oocyte to develop into a mature egg. The reproduction period was June–October. Females bearing eggs
were taken from June–August, and crabs with young were found from July–October. The females reproduced once a year but could
for more than one year. The number of eggs carried by a female varied greatly according to the size of the crab, ranging from
30 to 100 eggs. New-born crabs become mature after 1–2 years. The sex ratio was approximately 1∶1 in the overall population.
However, the larger crabs are predominantly male. The age distribution ofS. yangtsekinese was estimated from size frequency histograms. There were more adult crabs (over 70%) from June to October and more immature
crabs (over 50%) from November to May. 相似文献
5.
《中国海洋湖沼学报》2017,(1)
Aquaculture production efficiency may increase by using feed additives. This study investigated the effects of different dietary additives [w/w: 2% small peptides, 0.01% probiotics( Bacillus licheniformis) and 0.2% prebiotics(inulin)] on growth performance, digestive enzyme activities, and oxidative stress in juvenile Epinephelus coioides reared in artificial seawater of two salt concentrations(13.5 vs. 28.5). Weight gain rate was significantly higher in fish fed the diet supplemented with small peptides, B. licheniformis, inulin, or synbiotics than that in fish fed the basal diet; the greatest weight gain rate was found in fish fed the small peptide treatment [56.0% higher than basal diet]. Higher feed efficiency was detected in fish fed the diet supplemented with small peptides than that of fish in the other dietary treatments. Total protease activity in the stomach and intestines was highest in fish fed the small peptide-treated diet, whereas lipase activity was highest in those fed synbiotics(combination of Bacillus licheniformis and inulin) than that in fish fed the other treatments. Antioxidant enzyme(total superoxide dismutase and catalase) activities and hepatic malondialdehyde content were higher in fish receiving the dietary supplements and maintained in artificial seawater containing 13.5 salinity compared with those in the control(28.5). Hepatic catalase activity in grouper fed the diets with small peptides or synbiotics decreased significantly compared with that in control fish. Overall, the three types of additives improved growth rate of juvenile grouper and digestive enzymes activities to varying degrees but did not effectively improve antioxidant capacity under low-salinity stress conditions. 相似文献
6.
《中国海洋大学学报(英文版)》2017,(3)
The age, growth and maturation of Sthenoteuthis oualaniensis were determined with statolith data collected with a light purse seine from the Bashi Channel of central Pacific Ocean. The estimated longevity of the squid was no more than 6 months for females, and no more than 5 months for males. Growth in mantle length(ML) was best described by logistic models for both females and males, while growth in body weight(BW) was best fitted by power curves. The maximum absolute growth rate(AGR) and instantaneous growth rate(IGR) in ML or BW both occurred at 91–105 days for females and 76–90 days for males. Back calculated hatching dates were from October to January, with a peak in December, although the short duration of sampling date might have had an influence on the result. The lower percentage of mature females(37.2%) suggested that the study area during the sampling date was not a spawning ground for the species. Size and age at first maturity were 183 mm ML and 136 days for females, whereas they were 156 mm ML and 85 days for males. 相似文献
7.
贺兰山小松山岩体的岩石地球化学研究表明，基性岩的Mg^#为0．71～0．76，接近原生岩浆的值，超基性岩的Mg^#为0．80～0．89，具有岩浆早期堆晶的特征，稀土总量∑REE为（13．03～82．66）×10^-6；δ（Eu）为1．08～1．61，具弱正异常；（La／Yb）N为2．49～5．24，（Ce／Yb）N为3．01～4．97，配分曲线表现为轻稀土相对富集的右倾型。微量元素配分曲线图表现为大离子亲石元素富集。岩石地球化学数据综合分析证明，该岩体产于板内拉张环境，岩体形成过程中经历了岩浆分离结晶作用，后期发生了同化混染，岩体具有寻找铬-铜-镍型岩浆矿床的潜力。 相似文献
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PostlarvalPenaeus orientalis kishinouye were simultaneously sampled at three fixed stations near the mouth of the Dagu River estuary in northwestern Jiaozhou
Bay, China, at hourly intervals over a 49-h period in mid-June, 1984. The purpose of this sampling was to investigate the
prawn’s recruitment into estuaries from coastal areas.
The abundance of the postlarvae varied considerably between stations and time, but they tended to concentrate at the surface.
Maximum entropy spectral analysis was first applied in the study of prawn recruitment and it revealed that variations in abundance
involved a pronounced 12.4 hr cycle. It was concluded that natural tidal cycles had a strong influence on the changes of postlarval
abundance, in contrast with the minor effects of diet and other environmental cycles. A tidally varying cross-river gradient
of postlarval density was found. During flood tides the postlarvae were more abundant in the axis of the channel than over
the banks. The opposite held true during ebb tides. Mechanisms of the postlarval recruitment are discussed in terms of alternating
movements of the postlarvae between the banks and the channels in response to tidal cycles.
Contribution No. 1485 from the Institute of Oceanology, Academia Sinica 相似文献
10.
RELATIONSHIPS BETWEEN FRACTIONATIONS OF Pb, Cd, Cu, Zn AND Ni AND SOIL PROPERTIES IN URBAN SOILS OF CHANGCHUN, CHINA 总被引：4，自引：1，他引：3
GUOPing XIEZhong-lei LIJun KANGChun-li LIUJian-hua 《中国地理科学(英文版)》2005,15(2):179-185
1IN T R O D U C T IO N With therapiddevelopment of urbanizatio,nurban land was exploitedand utilizetdoform differendtomains be- ing subjectto many potentialpollutionsourcessuch as vehicleemission, industrialactivitieasnd household garbage.Particularl, yur… 相似文献
11.
Potassium, sodium, magnesium and iodine requirements of shrimp,Penaeus chinensis were studied. Orthogonal design was employed in this experiment. The composition of the basal diet consisted of fish meal,
peanut cake, corn meal, soybean cake, wheat bran, vitamin mix and mineral mix, and supplementations of potassium, sodium,
magnesium and iodine in the basal diet were made according to the L9(34) orthogonal table. The results indicated that iodine supplementation improved growth of the shrimp significantly and raised
survival very significantly, iodine requirement of the shrimp was 0.003%; sodium requirement was 0.87% or less; and that 1.1–1.3%
potassium and 0.18–0.38% magnesium in the diet were proper nutrition supplements for the shrimp.
Contribution No. 2342 from the Institute of Oceanology, Chinese Academy of Sciences. 相似文献
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VitalyA.Stepanov 《东北亚地学研究》2004,7(2):173-180
The Bamsk gold-ore deposit is located in the Amur region, the Far East of Russia. It is confined to the Early Cretaceous volcanicoplutonic uplift of central type, located in the Stanov folded-clumpy Pre-Cambrian system. The deposit is presented by a series of gold-bearing quartz and carbonate-quartz vein-stringer zones. They are confined to the super-intrusive zone of the Nevachansk subvolcanic intrusion of sienite-porphyric composition. The mineralization is being controlled by zone of fractures developed in the autochthone of the Bamsk fault. Quartz, carbonates and sericite prevail in the composition of ores. The quantity of ore minerals doesn‘t exceed 1% ～ 5%. Pyrite, chalcopyrite, galena and native gold are widely spread, Sheelite, gold and silver tellurides, sulphobismuthites, acanthite, sphalerite and cinnabar are less developed. Four stages of mineralization have been distinguished. Gold-sulphide-sulphosalt ore with tellurides of gold and silver is productive for gold. The following set of elements is typomorphic for the ores of the deposit: Au, Ag, Cu, Bi, Mo, Pb and Sb (W1, Pb1, Mo) -Cu- (Ag, Bi, Sb, Mn, W2,, Pb2) form the vertical series of zoning. Rocks, enclosing the mineralization are exposed to the processes of listvenitization-beresitization. The processes of gumbeization and argillization are less manifested. The age of the gold mineralization, determined by Rb-Sr method on ore-accompanying minerals, is 130.6 Ma. 相似文献
14.
Vitaly A.Stepanov 《世界地质(英文版)》2004,7(2)
The Bamsk gold-ore deposit is located in the Amur region, the Far East of Russia. It is confined to the Early Cretaceous volcanic-plutonic uplift of central type, located in the Stanov folded-clumpy Pre-Cambrian system. The deposit is presented by a series of gold-bearing quartz and carbonate-quartz vein-stringer zones. They are confined to the super-intrusive zone of the Nevachansk subvolcanic intrusion of sienite-porphyric composition. The mineralization is being controlled by zone of fractures developed in the autochthone ofthe Bamsk fault. Quartz, carbonates and sericite prevail in the composition of ores. The quantity of ore minerals doesn't exceed 1%～5%. Pyrite, chalcopyrite, galena and native gold are widely spread. Sheelite, gold and silver tellurides, sulphobismuthites, acanthite, sphalerite and cinnabar are less developed. Four stages of mineralization have been distinguished. Gold-sulphide-sulphosalt ore with tellurides of gold and silver is productive for gold. The following set of elements is typomorphic for the ores of the deposit: Au, Ag, Cu, Bi,Mo, Pb and Sb (W1, Pb1, Mo) -Cu- (Ag, Bi, Sb, Mn, W1, Pb2) form the vertical series of zoning. Rocks, enclosing the mineralization are exposed to the processes of listvenitization-beresitization. The processes of gumbeization and argillization are less manifested. The age of the gold mineralization, determined by Rb-Sr method on ore-accompanying minerals, is 130.6 Ma. 相似文献
15.
通过对传统GM(1,1)缺陷分析和改进的基于权的PGM(1,1)建模机理描述,顾及PGM(1,1)中背景值构造时取相同的参数不能充分降低模型的预测误差,对不同的时刻引入不同的参数来改进GM(1,1)背景值序列的计算公式,将这种背景值构造方法和灰元N引入GM(1,1)建立了新的白化方程。在建立的新的白化方程基础上,用龙格-库塔法以修正的初始值计算累加值的模拟序列。针对引入的参数较多问题,采用粒子群算法寻找满足相对误差均值最优的参数,从而建立了基于粒子群优化算法和加权灰色组合的PSO-GM模型。工程实例应用表明,新模型的拟合精度高,预测效果好,相对其他两种原有模型预测精度有明显提高。 相似文献
16.
Spatio-seasonal patterns of fish diversity,Haizhou Bay,China 总被引：3，自引：0，他引：3
Spatial-seasonal patterns in fish diversity in Haizhou Bay were studied based on stratified random surveys conducted in 2011.Principal component analysis was conducted to distinguish different diversity components,and the relationships among 11 diversity indices were explored.Generalized additive models were constructed to examine the environmental effects on diversity indices.Eleven diversity indices were grouped into four components:(1) species numbers and richness,(2) heterogeneous indices,(3) evenness,and(4) taxonomic relatedness.The results show that diversity indices among different components are complementary.Spatial patterns show that fish diversity was higher in coastal areas,which was affected by complex bottom topography and spatial variations of water mass and currents.Seasonal trends could be best explained by the seasonal migration of dominant fish species.Fish diversity generally declined with increasing depth except for taxonomic distinctness,which increased with latitude.In addition,bottom temperature had a significant effect on diversity index of richness.These results indicate that substrate complexity and environmental gradients had important influences on fish diversity patterns,and these factors should be considered in fishery resource management and conservation.Furthermore,diversity in two functional groups(demersal/pelagic fishes) was influenced by different environmental factors.Therefore,the distribution of individual species or new indicators in diversity should be applied to examine spatio-seasonal variations in fish diversity. 相似文献
17.
Han Jinfen Nan Fangru Feng Jia Lü Junping Liu Qi Liu Xudong Xie Shulian 《中国海洋湖沼学报》2022,40(2):729-744
Journal of Oceanology and Limnology - The genus Sheathia consists of over 20 species primarily distributed in Asia, Europe, Oceania, North America, and Africa. However, the origin and evolution of... 相似文献
18.
Euphausia pacific is an important source of natural astaxanthin.Studies were carried out to assess the extractability of astaxanthin from E.pacific using subcritical 1,1,1,2-tetrafluoroethane(R134a).To examine the effects of multiple process variables on the extraction yield,astaxanthin was extracted under various conditions of pressure(30-150 bar),temperature(303-343 K),time(10-50 min),flow rate(2-10 g min-1),moisture content(5.5%-63.61%),and particle size(0.25-0.109 mm).The results showed that the extraction yield increased with temperature,pressure,time and flow rate,but decreased with moisture content and particle size.A maximum yield of 87.74% was obtained under conditions of 100 bar,333 K,and 30 min with a flow rate of 6 g min-1 and a moisture content of 5.5%.The substantial astaxanthin yield obtained under low-pressure conditions demonstrates that subcritical R134a is a good alternative to CO 2 for extraction of astaxanthin from E.pacific. 相似文献
19.
黄海军 《中国海洋湖沼学报》1999,17(1):41-48
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20.
A combination of traditional fish sampling methods(hand-line and gill net) and modern hydroacoustic techniques were used to study fish community structure,distribution,and diel movements of fish on Zhubi Reef to enhance understanding of the ecosystem.We collected 126 individuals from 29 species,20 genera,17 families,three orders,and two classes using traditional gear.Perciforms were the dominant group in terms of species richness and biomass.The acoustic data indicated that very small(target strength[TS],dB) -60 dB) and small(-60 dB≤TS-45 dB) fish contributed the most to abundance and species richness on the coral reef,and that the proportion of medium-sized(-45 dB≤TS-35 dB) and largesized(-35 dB≤TS) fish increased gradually as depth increased.The single-target detection method revealed two distinct size classes during the day in the 12-16 and 16-20-m layers.One group consisted of very smallsized fish(TS-60 dB) and the other consisted of medium and large-sized fish(TS-55 dB).The number of single-target detections was significantly higher during the night than during the day(P0.05).The singletarget TS frequency distribution during the day was significantly different than during the night at depths of4-8,8-12,12-16,and 16-20 m.Significant differences were observed among the 4-8,8-12,12-16,and16-20-m-depth layers during day and night.Diel vertical movement was evidenced as fish began to spread and move upward just before sunset and began to assemble and descend shortly(15 min) after sunrise. 相似文献