Abstract:Climatic proxy of stable carbon isotope, together with total organic carbon content, in organic matter in lake sediment is one of the most effective methods to reconstruct past climatic evolutionary sequences. By coupling the indexes of TOC and δ¹³C_org in Xingcuo lake sediments and instrumental meteorological data in Zoige Basin, Eastern Tibetan Plateau and by building relative function relations among them, we probed quantitatively modern climatic signals recorded in those indexes. The results showed that there were remarkable relations between contents of TOC and precipitation, δ¹³C_org and air temperature, of which coefficence reaches to-0.67 and -0,75, respectively. Besides, we also demonstrated that average variation between contents of TOC and precipitation (dTC/dP) is -0.046%·mm^-1 and -0.84‰·℃^-1 for δ¹³C_org and air temperature (dδC/dT). According to the above, relative function relations among them were built.

Abstract:Based on the results of multi-environmental proxies (chronology,pigment s diatom concentration,stable isotope of organic carbon magnetic susceptibility chemicalelement) of lake sediment from Erhai Lake Yunnan Province, the series of climatic variations in the catchmentof Erhai Lake during the past 1800 year's has been established. The climatic changes with warm-dry and cold-wet alternations in Erhai Lake are different to the loess records in East Asia monsoon with warm-wet and cold-dry features. The characteristic periods such as the medieval warm period and Little Ice Age are both recorded in the lake sediments from Erhai Lake. The climatic characteristics with warm-dry and cold-wet alternation from the lacustrine records in Erhai Lake have the regional feature in Yunnan Plateau affected by southwest monsoon on the century scale. The lake sediment from Erhai Lake is rich with information of human activities.The proxies such as magnetic susceptibility chemical element-Fe,pigments have close relationship with the human activities during the historical period. The method of multi-environmental proxies analysis is useful to determine the response of climatic changes and human activities? which has important significance for the research as well as rational explanation on the high-iesolution records of lacustrine sediment in the past 1800 years.

Abstract:A lotof algae fossilswere found in Cenozoic lake sediments especiallyPediastrum fossil sed-imentar'y deposits in some places of China and also in some nearby seacoasts. For imitating Pedi-astrum mine ralization in lake sediments several species ofPediastrum are cultured using BBM medium and sea water with 18% salt. By optical and electronic microscope observation and photo-syntheic pigment analysis we found thatPediastrum boryanum,P. duplex var'clathratum andP.tetras etc. cannot grow well in sea water. If cultured in saline medium the specimen will die in a short period of time. We consider that probably thePediastrum fossil that appeared in marine sediments were transported to the sea by river. In order to prove the mineralization condition of in living organism and fossils ofPediastrum, the following analy sis is made. The fat-soluble substances are high and they contain a small amountof alkane alkene fatty acid and a great deal of plant pigments.Pediastrum has high H/C and low 0/C (atom number ratio) value. Therefore,it is agood resource of oilformation. The products of oxidative degradation of the insoluble cell-wall ofPediastrum are similar to the production obtained by kerogen, which is known to be of algalorigin. So the insolable materials of cell-wall are probably a source of kerogen during the deposition.

Abstract:This paper presents a computer simulation to invest ig ate the speciation of aluminum in acidic natural waters equilibria with mineral kaolinite based on the chemical equilibrium calculation. Various factors affect ing the dist ribution and concent rations of aluminum complexes are discussed. Compared with the case of equilibria with gibbsite, some unique characterist ics are discovered. This simulation has been verified by analyzing practical water samples and found in near-perfect ag reement with the experimental result s.The uncertainties in thermodynamic constant s are evaluated by the Monte Carlo simulation.

Abstract:Experimental studies were carried outon the purification of eut rophic lake water by simulative dy namic experiment using immobilized nit rogen cy cle bacteria.The results showed that the eut rophic water of Taihu Lake can be purified ef fectively as it pass through dif ferent immobilized nit rogen cy cle bacteria zones.The removal eff iciencies for Total N (TN), NH₄⁺-N with immobilized nit rogen cycle bacteria were 72.4% and 85.6%, respectively.It was found that the immobilized nit rogen cycle bacteria also have purificatory effecton eut rophic water of Taihu lake in winter (7℃), the removal ef ficiencies for Total N (TN), NH₄⁺-N were 55.6%, and 58.9%, respectively.The removal ef ficiencies for TN and NH₄⁺-N depended on the retention time of the water in eximperimental zone.

Abstract:Taihu Lake is a large shallow lake, located in the Delta of the Yang tze River.The hydrodynamic processes exert a profound influence on the lake environmental evolution.Based on the f ield investigation in Meiliang Bay, Taihu, in the summer of 1998, this paper at tempts to summarize the water current pat tern during the summer prevailing wind forcing.With the prevailing of southeast wind, the water current shows a clockwise circle, i.e.the water flows northward in the western coast and southward along the eastern coast.But in the northeast, close to the mouth of Liangxi River, a small inconsistent water current pat tern is presented.In the presence of above water current pat tern, the dist ribution of Chl-a concent ration, as well as the total nit rogen (TN) and to tal phospho rus (TP), shows a pattern associated with directions of water flowin the Meiliang Bay, i.e.Chl-a, TN and TP most ly concentrated in the northeastof Meiliang Bay.But the total dissolved nitrogen (TDN)and total dissolved phospho rus (TDP)concentrated in the northwestof bay because these components are less af fected by the transportation of water flow.The solid suspension (SS)concentration changed with the intensity of wind forcing and with water depth.The investig ation found that the concent ration of SS at the mouth of bay is g reater than that in the bay.Moreover, SS increased dramatically when the wind speed greater than 5m·s^-1, but slig ht difference with the water depth if wind speed less than 4-5m·s^-1, which indicated a high concent ration of organic mat ter in the upper layer of water.These findings will be very helpful for the protection of drinking water source, and understanding the relation between hydrodynamic processes and water transparency, primary productionn, etc.It is also of importance for the const ruction of Taihu Lake environmental management model.

Abstract:Terrain is an important factor influencing the velocity and the distribution of water current in lake.It decides the substance transpo rtation and dif fusion in lake water.This induces the study on the influence of the reclaiming of Mashan Dist ricton wind-driven current to be impo rtant to know the change of water quality in Meiliang hu Bay.The influences of the reclaiming of Mashan districton the wind-driven current were discussed on the base of the part 1 and part 2 of thre three-dimensional numerical experimenton hydrody namics in Lake Taihu, China.The results showed that the reclaiming in Mashan district had fewinfluences on the layer water current except the conversion layer water current.As to the conversion layer, it has great influences on velocities and directions of the conversion layer water current and the vertical averaged water current.It decides the structure of the circulation formed by the vertical averaged water current near the Mashan District.In particular, in case there blows SW wind these kinds of influences are very strong, e.g.the reclaiment changed the flow direction and the location of the g reat-scale circulation in the west partof the lake, and rest rained the water in the decreased the net water exchange rate between Meilianghu Bay and the open area of the lake by the reclaiment.Especially, in the case of SW, notonly about 98% of the net water exchanges were cut down, but also the water exchanges on the layer blow surface layer, middle layer and the layer above the bottom layer were cutdown in a relative high percentage.

Abstract:The stimulate experiments show the water flow plays an important role in the succession of plankton community.The species number and biomass of algae under weak water flow (0.124m ·s^-1)were highest in the experiments.This was coincided with the low ratio of NO₃/TDN.The algae abundance was increased from the stationary state to the strong water flow (0.319m·s^-1) state, the corresponding TDN/TN, TDP/TP were decreased at the same time.The photosynthetic rates from the stationary state to the strong water flow state were also decreased.The change of zooplanktonic species composition and abundance were larger than thatof phytoplankton.The change of cladoceran composition and abundance were ext remely strong.The change of species composition and abundance of phy to-zooplankton were influenced by water flow through the change of substance solids, transparency, light condition under water and the release of nutrients caused by physico-chemico-biololgical processing.

Abstract:The composition and activity of alkaline phosphatase in waters with dif ferent PO₄^3--P concentrations were studied ex perimentally.The results show:①The total alkaline phosphatase activity (TAPA)was decreased with the increase of PO₄^3--P concentration (r=-0.586,n=55). Based on the statistic analyses, when PO₄^3--P concentrations were between 0 to 0.010mg·L^-1, no significant dif ference was found in the TAPA.When PO₄^3--P concentrations exceeded 0.010mg·L^-1, the TAPA was significant difference (P<0.01).②The contents of APA in phy toplankton (PAPA), bacteria (BAPA)and dissolved (DAPA)were different.The ratio of DAPA to TAPA was the highest and BAPA was the smallest.③With the increasing of PO₄^3--P concent ration, the PAPA decreased.When PO₄^3--P concent rations were between 0 to 0.020mg· L^-1, over 0.020mg·L^-1 and over 0.200mg·L^-1, the PAPA were no significant, significant (P<0.05)and highly significant, respectively (P<0.01).④The BAPA showed no signif icant relationship with the PO₄^3--P concent ration.

Abstract:The contents of nit rogen and phosphorus and ferrous in the column sediments and their interst itial water were analy zed and compared in the main regions of Taihu Lake in 1998.The results show that the upper layer(0-10cm) contained higher contents in TN and TP and than the lower.And NH₄-N and PO₄-P in the interstitial water are a bit higher in the seriously-polluted waters than those in the gent ly-polluted waters.However, those of the lower layers are slightly higher in the gently-polluted waters than those in the seriously-polluted.It was indicated that there was no distinct corresponding relationships between NH₄-N/PO₄-P contents in the interstitial water and TN/TP contents in the sediments.The ferrous concentration in the interstitial water is distinctly in positive correlation with NH₄-N content (R=0.9234).

Abstract:In this paper, the pathology of "Appendage Shaking Disease" is studied by comparing normal and affected crabs via ultratructural investigation.A microoganism, whose size is between virus and bacterium, measured 0.22-0.35μm, is granular or clavate, bounded by a cell wall and a membrane, but it has nonucleus.In early stage of infection, the microorganisms are mainly located in blood cells, and in the last stage, most ROLs are distributed in the connective tissue of nervous organization, gill cavity, heart, periopod muscle, and digestive system.According to their size;shape, inner structure, locating places, and propagation mode, it can be inferred that they are Rickett sia-like organisms (RLOs)which should be the pathogens of "Appendage Shaking Disease".The pathogeny of RLOs is analyzed and discussed in this paper as well.

Abstract:Phosphorous is one of the key elements that lead to eut rophication.Pseudomonas sp.(X strain)was isolated from Microcystis aeruginosu in Taihu Lake.A group of test was designed to study the growth and phosphates [K₂HPO₄+KH₂PO₄(1:1)], organic phosphates (ATP), phosphorus fraction and growth factor.The results showed that the growth of X strain was not affected by inorganic phosphates and rest rained by ATP.The strain prefered inorganic phosphorus too rganic one when both available.X strain made use of particular phosphorus and extracted of algae that substituted for yeast extracts as growth factor.

Abstract:We examined the microo rganisms in reservoir water and obtained some corrupted the steel in reservoir, with multi-tube fermentation method.Incubating these microbes in different media in which there are different germicides with different concentrations, we screened more effective germicides to produce antiseptic paints.Discs made of the antiseptic paints were used to do bacteriostatic experiments.Long-time experiments were also done.The result showed that the No.22 germicide and its antiseptic paint are more effective materials, which can prevent the steel in reservoir from being corrupted.