Seasonal dynamics of the hepatotoxic microcystins in various organs of four freshwater bivalves from the large eutrophic Lake Taihu of subtropical China and the risk to human consumption

So far, little is known on the distribution of hepatotoxic microcystin (MC) in various organs of bivalves, and there is no study on MC accumulation in bivalves from Chinese waters. Distribution pattern and seasonal dynamics of MC-LR, -YR and -RR in various organs (hepatopancreas, intestine, visceral mass, gill, foot, and rest) of four edible freshwater mussels (Anodonta woodiana, Hyriopsis cumingii, Cristaria plicata, and Lamprotula leai) were studied monthly during Oct. 2003-Sep. 2004 in Lake Taihu with toxic cyanobacterial blooms in the summer. Qualitative and quantitative determinations of MCs in the organs were done by LC-MS and HPLC. The major toxins were present in the hepatopancreas (45.5-55.4%), followed by visceral mass with substantial amount of gonad (27.6-35.5%), whereas gill and foot were the least (1.8-5.1%). The maximum MC contents in the hepatopancreas, intestine, visceral mass, gill, foot, and rest were 38.48, 20.65, 1.70, 0.64, 0.58, and 0.61 mu g/g DW, respectively. There were rather good positive correlation in MC contents between intestines and hepatopancreas of the four bivalves (r = 0.75-0.97, p < 0.05). There appeared to be positive correlations between the maximum MC content in the hepatopancreas and the delta(13)C (r = 0.919) or delta(15)N (r = 0.878) of the foot, indicating that the different MC content in the hepatopancreas might be due to different food ingestion. A glutathione (GSH) conjugate of MC-LR was also detected in the foot sample of C. plicata. Among the foot samples analyzed, 54% were above the provisional WHO tolerable daily intake (TDI) level, and the mean daily intakes from the four bivalves were 8-23.5 times the TDI value when the bivalves are eaten as a whole, suggesting the high risk of consuming bivalves in Lake Taihu. (C) 2005 Wiley Periodicals, Inc.

Photocatalytic degradation of AZO dyes by supported TiO2+UVin aqueous solution

The photocatalytic degradation performance of photocatalysts TiO2 supported on 13-X, Na-Y, 4A zeolites with different loading content was evaluated using the photocatalytic oxidation of dyes direct fast scarlet 4BS and acid red 3B in aqueous medium. The results showed that the best reaction dosage of TiO2-zeolite catalysts is about 2 g/l and the photocatalytic kinetics follows first order for all supported catalysts. The photocatalytic activity order of the three series catalysts is 13X type >Y type >4A type. The physical state of titanium dioxide on the supports is evaluated by X-ray photoelectron spectra (XPS), powder X-ray diffraction (XRD), BET, and FTIR. (C) 2000 Elsevier Science Ltd. All rights reserved.

Metal dependent control of cis-/trans-1,4 regioselectivity in 1,3-butadiene polymerization catalyzed by transition metal complexes supported by 2,6-bis[1-(iminophenyl)ethyl]pyridine

Fe(III), Cr(III), Fe(II), Co(II) and Ni(II) chloride complexes supported by 2,6-bis[1-(iminophenyl)ethyl]pyridine have been synthesized and characterized along with single crystal X-ray diffraction. These complexes, in combination with MAO, have been examined in butadiene polymerization. The catalytic activity and regioselectivity are strongly controlled by metal center and cocatalyst (MAO/Co ratio dependent in the case of Co(II) complex). The activity decreases in the order of Fe(III) > Co(II) > Cr(III) approximate to Ni (II) complexes, in consistent with the space around the metal center. Polybutadiene with different microstructure content, from high trans-1,4 units (88-95% for iron(III) and Cr(III)), medium trans-1,4 and cis-1,4 units (55% and 35%, respectively, for iron(II)) to high cis-1,4 units 79% for Co(II) and 97% for Ni(II) call be easily achieved by varying of the metal center.

The magnetic and structural properties of hydrothermal-synthesized single-crystal Sn1-xFexO2 nanograins

The crystal structure and magnetic properties of Sn1-xFexO2 nanograins synthesized by simple hydrothermal method using SnCl4 center dot 5H(2)O and FeCl3 center dot 6H(2)O as raw materials are studied. No secondary phase was found in the XRD spectrum. The linear change of lattice volume for different Fe content strongly supports that the Fe3+ substitutes Sn4+ in SnO2 lattice. A Raman and IR spectra study indicated that the Fe incorporates into the SnO2 lattice. Both ferromagnetic and paramagnetic signals are detected in the Mossbauer spectra. The Sn1-xFexO2 (x <= 0.10) samples show room-temperature ferromagnetism (RTFM) and the saturation magnetization increased with increasing Fe percent. Fe ions present three kinds of magnetic behaviors including paramagnetic, ferromagnetic, and antiferromagnetic in the samples observed by investigation of the M-H and M-T curves. The weak RTFM was due to only a fraction of Fe ions contributing to magnetic-order coupling mediated by oxygen vacancy.

Rapid synthesis of Mn0.65Zn0.35Fe2O4/SiO2 homogeneous nanocomposites by modified sol-gel auto-combustion method

MnZn-ferrite/SiO2 nanocomposites with different silica content were successfully fabricated by a novel modified sol-gel auto-combustion method using citric acid as a chelating agent and tetraethyl orthosilicate (TEOS) as the source of silica matrix. The auto-combustion nature of the dried gel was studied by X-ray diffraction (XRD), Infrared spectra (IR), thermogravimetry (TG) and differential thermal analysis (DTA). Transmission electron microscope (TEM) observation shows that the MnZn-ferrite particles are homogeneously dispersed in silica matrix after auto-combustion of the dried gels. The magnetic properties vary with the silica content. The transition from the ferromagnetic to paramagnetic state is observed by Mossbauer spectra measurement with the increasing silica content. Vibrating sample magnetometer (VSM) shows that the magnetic properties of Mn0.65Zn0.35Fe2O4/SiO2 nanocomposites strongly depend on the silica content.

SYNTHESIS AND CHARACTERIZATION OF CHLORINATED POLYANILINE

Chlorinated polyaniline (Cl-PAn)with different CI content was synthesized. Typical Cl-PAn 100% soluble in THF both in doped and undoped state was characterized, and the chloroaddition mechanism was discussed.

Antioxidant activities of sulfated polysaccharide fractions from Porphyra haitanesis

Three sulfated polysaccharide fractions (F1, F2, and F3) were isolated from Porphyra haitanesis, an important economic alga in China, through anion-exchange column chromatography and their in vitro antioxidant activities were investigated in this study. Galactose was the main sugar unit of the three fractions. The analytical results indicated that polysaccharide fractions from P. haitanesis had similar chemical components to porphyran from other species, but differed in their high sulfate content. The sulfate content of F1, F2 and F3 was 17.4%, 20.5% and 33.5% respectively. All three polysaccharide fractions showed antioxidant activities. They had strong scavenging effect on superoxide radical, and much weaker effect on hydroxyl free radical. Lipid peroxide in rat liver microsome was significantly inhibited, and H2O2 induced hemolysis of rat erythrocyte was partly inhibited by F1, F2 and F3. Among them, F3 showed strongest scavenging effect on superoxide radical; F2 had strongest effect on hydroxyl radical and lipid peroxide.

Study on extraction of agaropectin from Gelidium amansii and its anticoagulant activity

Gelidium amansii agar was fractionated on DEAE-cellulose and four fractions were obtained sequentially. The yields of 1.0 mol/L NaCl fraction and 2.5 mol/L NaCl fraction were 2.80% and 2.03%. They are highly sulfated agar, and named as agaropectin with sulfate content being 22.8% and 32.5%, respectively. The anticoagulant experiment results show that agaropectin could effectively prolong the coagulation time in a dose-dependent manner in vitro. Agaropection could be absorbed and effectively prolong the plasma coagulation time in vivo. After intragastric administration at the doses of 100, 200, and 400 mg/kg.d in rats for 15 days, TT (thrombin time), CT (coagulation time), PT (prothrombin time), and APTT (activated partial thromboplastin time) could be effectively prolonged and the plasma Fib level could be significantly lowered.

Antioxidant activity of sulfated polysaccharide fractions extracted from Laminaria japonica

Fucoidan, a group of sulfated heteropolysaccharide, was extracted from Laminaria japonica, an important economic alga species in China. Three sulfated polysaccharide fractions (F1, F2, and F3) were successfully isolated through anion-exchange column chromatography and had their antioxidant activities investigated employing various established in vitro systems, including superoxide and hydroxyl radical scavenging activity, chelating ability, and reducing power. Chemical analysis suggested that F1 and F3 were heteropolysaccharide in which galactose was the major component, while F2 was a typical fucoidan. All fractions possessed considerable antioxidant activity, and F1, F2 and F3 had stronger antioxidant ability than fucoidan in certain tests. The correlation between the sulfate content and scavenging superoxide radical ability was positive. Available data obtained with in vitro models suggested that the ratio of sulfate content/fucose was an effective indicator to antioxidant activity of the samples. (C) 2007 Elsevier B.V. All rights reserved.

东天山红山高硫型浅成低温铜-金矿床氧化带的形成机理和硫酸盐矿物的系列发现及意义

Located in the Paleozoic uplift along the southern margin of Tu-Ha basin in eastern Xinjiang, the newly discovered Hongshan Cu-Au deposit occurs in the superimposed Mesozoic volcanic basin upon the north section of later Paleozoic Dananhu-Tousuquan accretionary arc. Kalatage Cu-Au orebelt is controlled by NWW-trend faults, and includes Hongshan and Meiling Cu-Au deposits. The host rocks of Hongshan ore district are mainly rhyolitic-dacitic ignimbrites, whereas Cu-Au mineralization is closely related to quartz porphyry, rhyolitic porphyry and granitic porphyry. Mineralization styles are dominantly veinlet-disseminated and veinlet, occasionally stockwork. The mineral association is chalcopyrite, pyrite, bornite, chalcocite and sphalerite. The hydrothermal alteration consists of silicfication, sericitization, alunitization, pyrophylitization, illitization, hydromuscovitization, and chloritization. Hongshan Cu-Au deposit, on the edge of the desert, is one of the driest areas in eastrn Tianshan. Moreover， the highest temperature has been up to 60℃, and the average rainfall receives only 34.1mm/y. The light rainfall and rapid evaporation in the vicinity of this deposit have allowed the formation of a great variety of water-soluble sulfates. Oxidization zone of this deposit lies on the upper part of primary sulfide orebodies appearing with a depth of 50-60m, which is dominant in sulfate minerals. 1. Based on the field observation, the volcanic and sub-volcanic rock composition, hydrothermal alteration, ore structure and mineralization characteristics, this paper proposed that the Hongshan Cu-Au deposit belongs to a transitional type from high-sulfide epithermal to porphyry Cu-Au deposit, which corresponds with the typical HS-epithermal deposit such as Zijinshan Au-Cu deposit in Fujian Province, SE-China. 2. The Hongshan copper-gold deposit was controlled by the tectonic, stratum, magma activity and volcanic apparatus, whereas Au mineralization is closely related to quartz porphyry, rhyolitic porphyry and fine grained pyritization in hydrothermal activity, and Cu mineralization is closely related to quartz porphyry and hydrothermal explosive breccia. 3. Oxidation zone of Hongshan Cu-Au deposit lies on the upper part of primary sulfide orebodies deposit. 23 sulfate minerals were identified in this work. The results of samples XRD and chemical analysis were furthermore confirmed through thermal, infrared spectrum and mössbauer spectrum analysis. Among those, nine minerals as Ferricopiapite, Cuprocopiapite, Rhomboclase, Parabutlerite, Krausite, Yavapaiite, Metasideronatrite Kroehnkite and Paracoquimbite were founded in China for the first time. And Paracoquimbite was secondly reported in the world (first case reported at 1938 in Chile). 4. EPMA analysis shows that Al impurity in crystal lattice is important to polytype formation of paracoquimbite and coquimbite besides stack fault. 5. Compared with Meiling Cu-Au deposit in the same Kalatage ore belt from the characteristics of δ34S of barite, lithofacies, hydrothermal alteration and homogeneous temperature, Hongshan Cu-Au deposit belongs to the same metallogenic system of HS-epithermal type as Meiling Cu-Au deposit. But Hongshan Cu-Au deposit has less extensive alteration and shallower denudation. 6. Sulfur isotope analyses show that δ34S values of pyrites vary in the range of +1.86‰~+5.69‰, with an average of 3.70‰, mostly in the range of +1.86‰~+3.20‰, and δ34Scp<δ34Spy. Therefore ore-forming fluid of porphyry comes from mantle and was contaminated by the earth’s crust. Sulfur isotope has reached balance in ore-forming process. 7. Sulfur isotope analyses show that δ34S values of sulfates vary in the range of +2.15‰~+6.73‰, with an average of +3.74‰, mostly equals as δ34S values of primary sulfides in Hongshan Cu-Au deposit. So supergene sulfates inherit sulfur of primary sulfide. δ34S values are mostly same in different sulfates. As well as pyrite and chalcopyrite, volcanic hot spring and associated native sulfur underground also provide water medium and sulfur during the formation process of sulfate. 8. According to the EPMA of sample chalcopyrite and pyrite in Hongshan Cu-Au, the value of Cu/Ni is 0.98-34.72, mostly close to the value of 5, which shows that Hongshan deposit is a typical volcanogenic magmaic hypothermal deposit. Au and Ag, Zn, Te and Bi are positive correlation, Cu and Hg, Se, Sb are positive correlation, indicates Au and Cu don’t locate in the factor of mineralization of same mineralization groups. The reasons of gold concentration in the oxidation zone are: 1). Change of redox potential (Eh) makes gold to deposit from the liquid of mineralization zone; 2). PH is one of the most factors of gold’s deposition; 3). Soluble complex and colloid of gold can be adsorbed easily. 9. The biotite and hornblende K-Ar isotopic ages from the wall rock－quartz diorite, biotite granite and monzonite granite are 231.99±3.45Ma, 237.97±2.36Ma and 296.53±6.69Ma respectively. The ore-bearing rhyolitic breccia lava contains breccia of the biotite granite which indicates the volcanism and related Cu-Au mineralization occurred later than the granite, possibly in Mesozoic. K-Ar ages of granitoids in Sanya, Baishiquan and Hongliugou area and Molybdenite Re-Os age of Baishan Mo deposit all are in Triassic. Besides late Paleozoic magmatism, igneous magmatic event of Mesozoic was widespread in eastern Tianshan. 10. The K-Ar age dating indicates that the K-Ar age of Voltaite occurred below surface 1m is 56.02±3.98Ma, K-Ar age of Ferricopiapite occurred below surface 1.5m is 8.62±1.12Ma, K-Ar age of Yavapaiite occurred below surface 14 m is 4.07±0.39Ma, and K-Ar age of Voltaite occurred below surface 10 m is 14.73±1.73Ma. So the age interval of oxidation zone of Hongshan copper-golden bed is between 60 -3.38Ma. Oxidization occurred at Caenozoic era (from 65Ma), which can be identified through comparing with different deposits oxidation zone in other countries. The coupling between global tectonic event and climatic change event which occur from Caenozoic era has some effect on epigeosphere system, which can act on the surface of bed oxidation zone similarly. It induces that the age mentioned above coincide with collision of India-Asia and multistage uplifting of Qinhai-Tibet Plateau happened subsequently. Bed oxidation zone is the effect and record of collision and uplifting of Tibet Plateau. The strong chemical weathering of surface accumulation to which was leaded by PETM event occurred Paleocene and Eocene is the reason of Voltaite sharply rises. On the contrary, Ferricopiapite formed due to the global cold weather. The predecessor did much research through biota, isotopes, susceptibility, but this paper try to use different sulfate mineral instead of climatic change. So the research of sulfate minerals not only indicates a great deal of oxidized zone feature, but also the intergrowth of sulfate minerals may be used to trace paleoenviroment and paleoclimate of oxidation zone. 11. Analysis of the information of alteration and mineralization features of four bore cores, induced activity polarization well logging and Eh-4 geophysical section, deep mineralization anomaly objects of Hongshan ore districts shows low resistance, middle and high polarization, measurements of Eh-4 consecutive conductance section show the existing of concealed porphyry ore body deeper than 450m, on the top of and around rock body there are low resistance body ranged from 100-300Ω•m, this area may be the ore-bearing part. In a word, Hongshan Cu-Au deposit deposit is a combine of upper HS-style epithermal Au deposit and deeper porphyry mineralization system. It has great potential to find large HS-style epithermal-porphyry Au-Cu deposits. This paper consists of seven chapters and twenty seven sections. The geological character of deposit is basic condition in this work. Constitute of oxidation zone, research of sulfate mineral, relation between oxidation and primary zone, K-Ar ages of potassic sulfate are key parts of thesis. Genesis of ore deposit is the further expansion of this research. Analysis of ore-controlling factors is the penetration above basic. Analysis of potential is application of exploration.

地震资料叠前储层预测综合研究--以辽中凹陷东二下段浊积扇气藏为例

Reservoir prediction techniques from prestack seismic are among the most important ones for exploration of lithologic hydrocarbon reservoir. In this paper, we set the turbidite fan sandstone reservoir in Liao-Zhong depress as our researching target, and aims to solve the apllication difficulties on pre-stack inversion in the area, where the drilling data is scarce and the reservoir is lateral varied. Meanwhile, AVO analysis and pre-stack inversion for gas-bearing detection is systematically researched. The seismic reflection characters of gas-bearing sandstone in turbidite fan with different fluid content are defined, after analyzing results from AVO seismic simulation and porous fluid replacement of real log data, and under the guides of the seismic characters from classical gas-bearing sandstone reservoir and numerical simulation for complicate gas-bearing sandstone. It is confirmed that detecting gas-bearing sandstone in turbidite fan via AVO technologies is feasible. In terms of AVO analysis, two AVO characters, fluid detection factor and product of intercept and gradient, can effectively identify top and bottom boundaries and lateral range of tuibidite gas sand by comparing real drilling data. Cross-plotting of near and far angle stack data could avoid the correlation existing in P-G analysis. After comparing the acoustic impedance inversions with routine stacked data and AVO intercept, impedance derived from AVO intercept attribute could reduce the acoustic impedance estimating error which is caused by AVO. On the aspect of elastic impedance inversion, the AVO information in the pre-stack gathers is properly reserved by creating partial angle stack data. By the far angle elastic impedance alone, the gas sand, with abnormally low range of values, can be identified from the background rocks. The boundary of gas sand can also be clearly determined by cross-plotting of near and far angle elastic impedances. The accuracy of far angle elastic impedance is very sensitive to the parameter K, and by taking the statistical average of Vp/Vs on the targeted section in key wells, the accuracy of low frequency trends is gurranteed; the intensive absorsion within the area of the gas sand, which tends to push the spectral of seismic data to the lower end, will cause errors on the inversion result of elastic impedance. The solution is to confine the inversion on the interested area by improving the wavelet. On the aspect of prestack AVA simultaneous inversion, the constraint of local rock-physical trends between velocities of P-wave、S-wave and density successfully removes the instability of inversion, thus improves the precision of the resulting elastic parameters. Plenty of data on rock properties are derived via AVO analysis and prestack seismic data inversion. Based on them, the fluid anomaly is analysized and lithological interpretation are conducted. The distribution of gas sand can be consistently determined via various of ways, such as cross-plotting of P and G attributes, near and far partial angle stack data, near and far angle elastic impedances, λρ and Vp/Vs, etc. The shear modulo and density are also reliable enough to be used for lithological interpretation. We successfully applied the AVO analysis and pre-stack inversion techniques to gas detecting for turbidite fan sand reservoir in Liao-Zhong depression.

三峡库区堆积层斜坡稳定性分级与应用研究

Considering the lacking of standard for the classification of Accumulative slopes so far, research working was conducted based on the results of geological investigation, data analysis and experiment carried out in Wanzhou. By mean of statistical method and grey system, the author studied in detail inflationary factors to Accumulative slopes. In order to study the mechanism of Rock-Soil Aggregate (RSA), numerical testing method was used. Coordinates in the two and three dimensional space and its corresponding rock fragments in the sample were generated randomly by VB and Particle flow code. After being built the models of RSA with different rock content, uniaxial and triaxial numerical simulation tests were carried out respectively. In order to study the effect of rainfall in Accumulative slopes, in situ infiltration testing had been conducted on site in Wanzhou, Three Gorges Area. Relationship between the infiltration rate and amount of precipitation has been obtained. Eleven factors are considered in the classification of Accumulative slopes in this paper.(1)On the basis of four basic factors and four inducing factors, sum-and-difference method for the classification system has been built. (2)After weight of factors being determined by analytic hierarchy process and membership function of Accumulative slopes stability being built in virtue of fuzzy mathematics, AHP-FM model of Accumulative slopes stability has been completed. In the end of this paper, having been applied on stability of Accumulative slopes in Three Gorge area and compared with result by limit equilibrium, classification system has good effect.

Effect of glass substrate and deposition technique on the properties of sol gel TiO2 thin films

Na+ ions have a detrimental effect on the photocatalytic activity of thin sot gel films deposited on soda lime glass due to their diffusion into the film during the calcination process. Given that the content of sodium in glass substrate might be the crucial parameter in determining the activity of a photocatalyst, the aim of the present work was the comparison of the photoinduced properties of a thin TiO2 film prepared on three different glass substrates namely on quartz (Q) glass, borosilicate (BS) glass and soda lime (SL) glass which have different sodium content. The prepared layers were characterised by X-ray diffraction and UV-vis spectroscopy. The diffusion of Na+ from the substrate into the layers was determined by Glow Discharge Atomic Emission Spectroscopy. The photocatalytic activities of the films were assessed using two model pollutant test systems (resazurin/resorufin ink and stearic acid film), which appeared to correlate reasonably well. It was observed that TiO2 layer on SL glass has a brookite crystalline structure while the TiO2 layer on BS and Q glass has an anatase crystalline structure. On the other hand, the photodegradation of the model dye on TiO2 films deposited on Q and BS glass is about an order higher than on SL glass. The low sodium content of BS glass makes it the most suitable substrate for the deposition of photoactive sol gel TiO2 films. (C) 2011 Elsevier B.V. All rights reserved.

Agar extraction from integrated multitrophic aquacultured Gracilaria vermiculophylla: Evaluation of a microwave-assisted process using response surface methodology

Microwave-assisted extraction (MAE) of agar from Gracilaria vermiculophylla, produced in an integrated multitrophic aquaculture (IMTA) system, from Ria de Aveiro (northwestern Portugal), was tested and optimized using response surface methodology. The influence of the MAE operational parameters (extraction time, temperature, solvent volume and stirring speed) on the physical and chemical properties of agar (yield, gel strength, gelling and melting temperatures, as well as, sulphate and 3,6-anhydro-Lgalactose contents) was evaluated in a 2^4 orthogonal composite design. The quality of the extracted agar compared favorably with the attained using traditional extraction (2 h at 85ºC) while reducing drastically extraction time, solvent consumption and waste disposal requirements. Agar MAE optimum results were: an yield of 14.4 ± 0.4%, a gel strength of 1331 ± 51 g/cm2, 40.7 ± 0.2 _C gelling temperature, 93.1 ± 0.5ºC melting temperature, 1.73 ± 0.13% sulfate content and 39.4 ± 0.3% 3,6-anhydro-L-galactose content. Furthermore, this study suggests the feasibility of the exploitation of G. vermiculophylla grew in IMTA systems for agar production.

A expressão dramática no desenvolvimento da formação pessoal e social da criança em idade pré-escolar

Relatório da Prática Profissional Supervisionada Mestrado em Educação Pré-Escolar