Bacillus solisalsi sp nov., a halotolerant, alkaliphilic bacterium isolated from soil around a salt lake

A novel Gram-positive, motile, rod-shaped bacterium isolated from a saline soil in China was characterized by a polyphasic taxonomic approach. The strain, designated YC1(T), was halotolerant [tolerating up to 15 % (w/v) NaCl] and alkaliphilic (growing at

准噶尔盆地西缘车排子地区隐蔽油气藏识别与勘探目标研究

After the half century exploration, previous scholar evaluating thought that there were poor Petro-Geological conditions in Chepaizi area of Zhungar basin. Recently, with the great discovery in the Well Pai2,the study on the subtle reservoir in Chepaizi area are gained great attentions by the scholars all over the world day by day. Chepaizi uplift is a inherited palaeohigh, and its structural traps are undeveloped. The sedimentary faces of Shawan Formation of Neogene have apron type of alluvial fan, alluvial plain, alluvial fan delta, salt lake, shore and shallow lake and so on. The sedimentary faces of Shawan Formation of Well Pai2 is alluvial fan delta and shore and shallow lake, the first part of Shawan Formation(N1s1) is the main target for exploration. Using the seismic forward, property analysis, spectral factorization, logging restrain inversion and so on, The spatial distribution of the sand reservoir and its hydrocarbon, predicted and 20 lithology traps in 5 substratums were carried out. The traps have a total areal of 107.13 Km2, and the geological reserves in it can reach 8703.7×104t. After comprehensive research on the trap,reservoir, cap and the condition of the hydrocarbon accumulation, it is considered that the elements of hydrocarbon in Chepaizi area are various. Because it can’t generate hydrocarbon, the oil and gas conducting and accumulation are the most important factors in this area, and the validity of the lithology traps in monoclinal is another important factor. Research indicates that the master control factor of the subtle reservoir in Chepaizi area is fault and sand. The sand of beach and sandbar provide the space for the hydrocarbon accumulation, the fault provides the migration channel for the hydrocarbon. Most faults have a characteristics of up seal and the down open, which not only can conduct hydrocarbon, but also can prevent hydrocarbon overtopping, therefore the effect trap is results of good match of fault and sand.

珠穆朗玛峰东绒布冰川表层雪中的气候和环境记录

Snow chemistry research helps to found the basis of studying ice cores. Samples of fresh snow and snow pits were collected from East Rongbuk Glacier on the north slope of Mt. Qomolangma during October, 2002. Major soluble ions (Na~+, NH_4~+, K~+, Mg~(2+), Ca~(2+), Cl~-, NO_3~- and SO_4~(2-)) andδ~(18)O were detected for analysis. Source analysis showed that major sources contributing to the snow chemistry in Mt. Qomolangma region are remote Asian dust and salt lake dust, sea-salt aerosols from Indian monsoon, local rock-mineral dust, human activities and natural atmospheric procedures. Principal factor analysis indicated that high-concentration group was dominated by continental dust with little oceanic source, indicating continental or local precipitation, while the low group dominated by oceanic aerosols indicated oceanic precipitation. Local mineral dust was a minor a source characterized mainly by Ca~(2+), Mg~(2+) contribution. Ammonia related mainly with continental dusts and nitrogen-circulation processes in the atmosphere, it also had a peculiar source should be seasonal agriculture activities in the south Asia. Nitrate showed bad correlations with other ions for its special chemical characteristics. δ~(18)O and major soluble ions displayed obvious seasonal variations. The summer precipitation had very low ion loadings and relatively lower heavy oxygen isotope from the Indian Ocean with occasionally ion peaks formed by local evaporation. While the winter and spring precipitation had high ion loadings and δ~(18)O value for the great amount of continental dust and evaporated vapors. Frequent fluctuations of δ~(18)O and ion concentration occur during the transitional period, indicating alternated precipitations by various air mass types. Ion concentration in snow from the Qomolangma region is comparable with from the Antactica, representing relatively pure background of atmospheric environment on earth. While the high concentration is close to the glaciers' located near the major sources of Asian dust. Compared with the snow chemistry of South Slope of Mt. Qomolangma, the North Slope has lower sea-salt ion concentration during summer monsoon and higher concentration of all major ions during pre- and post-monsoon period due to it's special geophysical location.

Impact of Brunswick river mouth training walls on adjacent beaches, Brunswick heads, New South Wales, Australia

River training walls have been built at scores of locations along the NSW coast and their impacts on shoreline change are still not fully understood. In this study, the Brunswick River entrance and adjacent beaches are selected for examination of the impact of the construction of major training walls. Thirteen sets of aerial photographs taken between 1947 and 1994 are used in a CIS approach to accurately determine tire shoreline Position, beach contours and sand volumes, and their changes in both time and space, and then to assess the contribution of both tire structures and natural hydrodynamic conditions to large scale (years-decades and kilometres) beach changes. The impact of the training walls can be divided into four stages: natural conditions prior to their construction (pre 1959), major downdrift erosion and updrift accretion during and. following the construction of the walls in 1959 similar to 1962 and 1966. diminishing impact of the walls between 1966 and 1987, and finally no apparent impact between 1987 similar to 1994. The impact extends horizontally about 8 km updrift and 17 km downdrift, and temporally up to 25 years..

利用MC-ICP-MS测定硼同位素及其在西藏地热和盐湖中的初步应用

Based on previous studies, boron can be separated from aqueous samples with Amberlite IRA-743 resin. Experiments on the elute temperature, elute volume and the dynamic resin exchange capacity have been performed in this study. Results show that the dynamic exchange capacity of the resin is 4.2mg B/g and at room temperature, boron fixed on the resin within this capacity level can be extracted quantitatively by using 5ml 2%HNO3. A new procedure has been developed for the measurement of boron isotope ratios in water samples using a Neptune MC-ICP-MS, after resolving the memory effect, which is a key problem, and investigating the impacts of mass bias and Si matrix effect. Using this method, it usually takes 20 min to perform one measurement on 0.1ppm boron solution with a precision of 0.23‰ (SD). If the relative deviation between a sample and the standard is large, the washout time needs to be doubled to achieve a higher precision. δ11B values of water samples from Yangbajing geothermal field vary from -10.53 to -9.13‰. Owing to the large difference B concentration and the small B isotope difference between deep geothermal water and surface water, B isotope ratios of the shallow geothermal fluids are dominated by the deep end member rather than the shallower one in the mixing process. As a consequence, δ11B-B relation is indicative basically of a dilution process. Vapor-liquid separation and calcite scaling also greatly influence B isotope fractionation. δ11B values of water samples from Dagejia geothermal field are from -15.98‰ to -11.67‰. Boron in Changma River near the field has two sources, freshwater lakes (Dajiamang Lake and Canke Lake) and geothermal waters. Finally, a preliminary discussion is included on boron geochemical characteristics of the salt lakes in Shuanghu area and other geothermal fields, to provide information for future studies on boron isotope geochemistry of geothermal systems and salt lakes in Tibet.

Habitat use by wintering Ruddy Shelduck at Lashihai Lake, Lijiang, China

Habitat use by wintering Ruddy Shelduck (Tadorna ferruginea) in Lijiang Lashihai Lake of southwest China was studied from 1 November 1999 to 29 April 2000. We divided habitats into five types-deep water, shallow water, mudflat, grassland and farmland. Shallow water and grassland, with rich food and easily accessible water, were preferred by wintering Ruddy Shelducks, Farmland was preferred in mid-winter but avoided in early winter and late winter. Even in mid-winter, the feeding Ruddy Shelduck on farmland were not equally distributed in fields and preferred wet fields (just irrigated) and avoided dry fields. In dry fields, the distances to water sources had great impact on the feeding distribution. Mudflats were only selected in later winter, coinciding with the growth of water-weeds. Deep-water areas were always avoided. Prohibition of human disturbance and retaining shallow water areas and grassland are important measures to mitigate conflict between Ruddy Sheldruck and local people.

Accumulation of hepatotoxic microcystins in freshwater mussels, aquatic insect larvae and oligochaetes in a large, shallow eutrophic lake (Lake Chaohu) of subtropical China

This paper studied the seasonal changes of two common microcystins (MCs), MC-RR and -LR, in the commercially important mussel Corbicula fluminea in Lake Chaohu, where there occurred dense cyanobacteria. Occasional measurements were also made for MC in the mussel Arconaia lanceolat, the oligochaete Limnodilus hoffineisteri and the insect larva Chironomus sp. Mean MC of C. fluminea was much higher in hepatopancreas than in intestine and foot. Our study is the first to report accumulation of MCs in oligochaetes and aquatic insect larvae. The hi-h contents of MCs in the insect larvae suggest a great possibility for the transfer of MCs to benthos-feeding omnivores like common carp. According to the provisional standard by the WHO, 28.6% of the collected C. fluminea were harmful for human consumption, assuming a daily consumption of 300 by a person. It is recommended that edible mussels should not be collected for human consumption during toxic cyanobacterial blooms in Lake Chaohu.

Carbon source/sink function of a subtropical, eutrophic lake determined from an overall mass balance and a gas exchange and carbon burial balance

Although studies on carbon burial in lake sediments have shown that lakes are disproportionately important carbon sinks, many studies on gaseous carbon exchange across the water-air interface have demonstrated that lakes are supersaturated with CO2 and CH4 causing a net release of CO2 and CH4 to the atmosphere. In order to more accurately estimate the net carbon source/sink function of lake ecosystems, a more comprehensive carbon budget is needed, especially for gaseous carbon exchange across the water-air interface. Using two methods, overall mass balance and gas exchange and carbon burial balance, we assessed the carbon source/sink function of Lake Donghu, a subtropical, eutrophic take, from April 2003 to March 2004. With the overall mass balance calculations, total carbon input was 14 905 t, total carbon output was 4950 1, and net carbon budget was +9955 t, suggesting that Lake Donghu was a great carbon sink. For the gas exchange and carbon burial balance, gaseous carbon (CO2 and CH4) emission across the water-air interface totaled 752 t while carbon burial in the lake sediment was 9477 t. The ratio of carbon emission into the atmosphere to carbon burial into the sediment was only 0.08. This low ratio indicates that Lake Donghu is a great carbon sink. Results showed good agreement between the two methods with both showing Lake Donghu to be a great carbon sink. This results from the high primary production of Lake Donghu, substantive allochthonous carbon inputs and intensive anthropogenic activity. Gaseous carbon emission accounted for about 15% of the total carbon output, indicating that the total output would be underestimated without including gaseous carbon exchange. (C) 2007 Elsevier Ltd. All rights reserved.

Estimation of the natural purification rate of a eutrophic lake after pollutant removal

Pollution resulting from increased human activities is threatening Lake Donghu, its effects being characterized by serious eutrophication. A steady increase of phosphorus loading is the most important factor of the lake eutrophication. Pollution external control projects are being implemented and will be accomplished before the year 2010. In order to predict the restoration rate by the lake's self-purification after the projects of external control, a model of predicting the removal rate of total phosphorus (TP) from lake water is developed, and a brief method of estimating the release and export rate of sediment phosphorus is suggested. Results show that, on the premise of external loading fully controlled. The restoration needs about 55 years or more. Obviously, the great P pool in the sediment will be a limiting factor of preventing the improvement of water quality after the external loading is under control. Based on the estimation we conclude that after the external control projects before 2010, in order to restore the lake in a few years, although highly cost, the first step must be the sediment dredging to remove internal loading. The second step is diverting water of River Changjiang into the lake to accelerate the improvement of lake water. Otherwise, removal of pollutant sources will become meaningless. (c) 2006 Elsevier B.V. All rights reserved.

Sedimentary records of water environment in lake Chaohu in the Yangtze delta region, China

Three lacustrine core samples were collected from Chaohu lake in December 2002 in the Yangtze delta region. The grain sizes were analyzed using a Laser Analyzer to obtain grain-size parameters. Sediment geochronology was determined in radioisotopes Cs-137 and the average sedimentary rates are 0.29cm.a(-1), 0.35 cm.a(-1) and 0.24cm-a(-1) in Cores C 1, C2 and C3, respectively. The grain-size parameters of the deposits vary regularly with the fluctuation of hydrodynamics. From 1950s to the beginning of 20th century, coarse-grained sediment was deposited, suggesting strong hydraulic conditions and high water-level periods with much precipitation; from the start of 20(th) century to latter half of 18(th) century, fine-grained sediment was deposited, indicating that weak hydraulic conditions and low water-level periods with less precipitation; before the first half of 18(th) century, coarse-grained sediment was deposited, suggesting great velocity of flow and high water-level periods of more precipitation.

Budgets and dynamics of nitrogen and phosphorus in a shallow, hypereutrophic lake in China

Budgets and dynamics of nitrogen and phosphorus in Lake Donghu were investigated from Oct. 1997 to Sept. 1999. The water residence time was estimated to be 89 days in 1997-1998 and 124 days in 1998-1999. The total external loadings were 53 g N m(-2) yr(-1) and 3.2 g P m(-2) yr(-1) in 1997-1998, and 42 g N m(-2) yr(-1) and 3.1 g P m(-2) yr(-1) in 1998-1999. On average, about 80% of nitrogen and phosphorus input was from sewage outlets, while the rest was from land runoff and precipitation. Ammonium ion was the most abundant form of inorganic nitrogen in the sewage. The nutrient output was mainly through water outflow and fish catch. The percentages of nutrients in fish were estimated to be 7.8%-11.2% for nitrogen and 47.6%- 49.6% for phosphorus. Lake Donghu has a very high nutrient retention (63% for nitrogen and 79% for phosphorus) mainly due to its closure and long water residence time. Sedimentation is an important nutrient retention mechanism in this lake. Using mass balance method, we estimated that denitrification of Lake Donghu involves about 50% of the retained nitrogen. Lake Donghu is rich in inorganic nitrogen and phosphorus and showed great seasonal variation.

Numerical Study on the Distribution Characteristics of TP in Taihu Lake, China

A depth-averaged two-dimensional hydrodynamics model and a two-dimensional water quality model, bases on the alternating direction implicit (ADI) method, is developed to study the distribution characteristics of total phosphorus (TP) in Taihu Lake. Wind stress, the pollution source from the inflow rivers, releasing rate of TP from the bottom sediment and water diversion from Yangtze River are the effecting factors of TP distribution. By using the model proposed in this paper, the concentration field of the total phosphorus was simulated, which leads to the conclusion that the flow field has a great influence on the spatial and temporal distribution of TP in the Taihu Lake.

Numerical Study on the Spatial and Temporal Characteristics of Water Quality in the Taihu Lake of China

Taihu Lake is the third largest fresh water lake in China. With the fast economic development, abundant industrial and agricultural waste water has been discharged into Taihu Lake, causing the eutrophication of the water quality, which greatly affected the water utility. In the past decades, the treatment of Taihu Lake has witnessed limited success. Therefore, it is practically and theoretically significant to study the eutrophication of Taihu Lake. This research has focused on the issue of water quality including the characteristics of spatial and temporal distributions, and the rules of nutrient diffusion in the Taihu lake area. Based on the monitoring data, the basis distribution characteristics of water quality in Taihu Lake are analyzed. Comparing Taihu Lake with other Lakes shows that one important reason for Taihu eutrophication is the long period of water retention. A transporting and diffusing model of Taihu nutrient is developed by combining with the hydrodynamics model. Using the model, the concentration field of the total phosphorus (TP) and the influence of wind-driven current are numerically investigated, which leads to the conclusion that the flow field has a great influence on the spatial and temporal distributions of TP in Taihu Lake. Furthermore, the effect for improving the water quality by the project of water diversion from the Yangtze River to Taihu Lake was analyzed by simulation. The results demonstrate that short-term water diversion cannot improve the water quality of the heavily-polluted Meiliang Bay and the western bank areas of Taihu Lake.

Spatial variability in water quality and surface sediment diatom assemblages in a complex lake basin,lake of the woods,ontario,canada

Lake of the Woods (LOW) is an international waterbody spanning the Canadian provinces of Ontario and Manitoba, and the U.S. state of Minnesota. In recent years, there has been a perception that water quality has deteriorated in northern regions of the lake, with all increase in the frequency and intensity of toxin-producing cyanobacterial blooms. However, given the lack of long-term data these trends are difficult to verify. As a first step, we examine spatial and seasonal patterns in water quality in this highly complex lake on the Canadian Shield. Further, we examine surface sediment diatom assemblages across multiple sites to determine if they track within-take differences in environmental conditions. Our results show that there are significant spatial patterns in water quality in LOW. Principal Component Analysis divides the lake into three geographic zones based primarily on algal nutrients (i.e., total phosphorus, TP), with the highest concentrations at sites proximal to Rainy River. This variation is closely tracked by sedimentary diatom assemblages, with [TP] explaining 43% of the variation in diatom assemblages across sites. The close correlation between water quality and the surface sediment diatom record indicate that paleoecological models could be used to provide data on the relative importance of natural and anthropogenic sources of nutrients to the lake.

Electrolytic Deposition and Diffusion of Lithium onto Magnesium-9 Wt Pct Yttrium Bulk Alloy in Low-Temperature Molten Salt of Lithium Chloride and Potassium Chloride

The electrolytic deposition and diffusion of lithium onto bulk magnesium-9 wt pct yttrium alloy cathode in molten salt of 47 wt pct lithium chloride and 53 wt pct potassium chloride at 693 K were investigated. Results show that magnesium-yttrium-lithium ternary alloys are formed on the surface of the cathodes, and a penetration depth of 642 mu m is acquired after 2 hours of electrolysis at the cathodic current density of 0.06 A center dot cm(-2). The diffusion of lithium results in a great amount of precipitates in the lithium containing layer. These precipitates are the compound of Mg41Y5, which arrange along the grain boundaries and hinder the diffusion of lithium, and solid solution of yttrium in magnesium. The grain boundaries and the twins of the magnesium-9 wt pct yttrium substrate also have negative effects on the diffusion of lithium.