Characteristics and Effects of Inorganic Nitrogen in East Water-source and Inflow Rivers of Chaohu Lake

[Objective] To study the characteristics and effects of inorganic nitrogen in east water-source and inflow rivers of Chaohu Lake. [Method] The speciation and distribution characteristics of dissolvable inorganic nitrogen （DIN） in east water-source and inflow rivers of Chaohu Lake were investigated, and their effects on water qual- ity were examined. [Result] The concentrations of NH3-N and NO2--N were the high in flood season, and low in non-flood season, while the concentration of NO3--N pre- sented the opposite trend; the concentration of NO3--N was the highest in Shuangqiao estuary, where the pollution was the worst. DIN in Zhegao estuary and Xiaozhegao estuary was mainly caused by domestic sewage and industrial wastewaters; surface runoff and pollution from ships contribute the most to the DIN content in Shuangqiao estuary. [Conclusion] This study provided basic data and theoretical basis for the control and management of eutrophication in Chaohu Lake.

Assessment of the Recent Hydromorphological Features of Nokoue Lake and Its Channels (South-East Benin)

Based on 2022 and 2023 hydrometric data and satellite images (Sentinel 2022, SPOT 2010), this study aims to present the Nokoué Lake and its channels’ re-cent hydromorphological characteristics. Integrating flow, tributary morphology, and topography data determined specific power values along the axes studied. The values obtained range from 2.69 to 12.92 W/m2 for Ouémé River and 2.46 to 10.99 W/m2 for Sô River. The resulting water erosion on banks and bottoms is of linear, areolar, or gully and claw types. Lake bathymetry varies from -0.5 to -2.6 m (low flow period) and -1 to -4 m;in the Ouémé, Sô, and Totchè rivers, it varies from -5 m to -7 m, reaching -10 m at the Cotonou channel entrance (flood period). Bathymetric profiles reveal varied “U”, “V” and “Intermediate” bottom morphologies, influenced by erosion/sedimentation processes and human activities. The flow facies identified are lentic in the northern tributaries and lotic in the Cotonou and Totchè canals. Spatial analysis identified nine (09) thematic classes. In 2022, the surface area of the water body has increased from 274 km2 at low water to 280 km2 at high water, whereas in 2010 (a recent year of exceptional flooding), the surface area was 270 km2 at low water and 277 km2 at high water. Significant changes in land use are observed between 2010 and 2022. The floodplain area decreased slightly, from 421 km2 in 2010 (year of exceptional flooding) to 419 km2 in 2022. The evolution of land use shows a progressive expansion of the urban environment to the detriment of the natural environment. In the medium to long term, this trend could threaten the hydromorphological balance and even the existence of this important lagoon ecosystem.

高速S-CO_(2)向心透平几何参数优化及变工况特性分析

透平是热力循环中实现热功转换的核心设备,优化透平几何参数以改善气动性能,是提升系统热效率的关键。该文以面向某船舶主机烟气余热利用的超临界二氧化碳布雷顿循环透平设计参数为基础,给出向心透平主要几何参数,采用耦合CO_(2)真实物性参数的CFX仿真方法,分析几何参数动、静叶包角以及叶轮出口几何角对透平性能的影响规律并进行参数优化,进一步研究非设计工况下的透平运行特性。结果表明:增大静叶包角会使动叶前缘出现扰动涡流并减少余速损失,增大叶轮出口几何角,动叶包角对透平效率的影响规律不变,但效率峰值点会沿动叶包角减小的方向移动;动、静叶包角和叶轮出口几何角分别为49°、21.5°、25°时透平设计点总-静等熵效率高达87.99%,相比优化前,提高0.54个百分点;透平偏离设计点±20%工况下等熵效率大于80%。结果可为超临界二氧化碳高速向心透平设计提供一定参考。

Competitive Consumption of the Lake Kinneret (Israel) Plankton by <i>Hypophthalmichthys molitrix</i>and <i>Sarotherodon galilaeus</i>

An outdoor tank experiment was carried out for the assessing of the impacts of Sarotherodon galilaeus (Galilee Saint Peter’s Fish;Cichlidae) (SG) and Hypophthalmichthys molitriox (Silver Carp;Cyprinidae) (SC) on Lake Kinneret (Israel) plankton. In order to evaluate the interaction effect, the experiments were of replicated 2 × 2 factorial design: TG × SC. A lot of interaction effects were indicated showing that the effects of the two fishes were not independent and potentially competitors. SG suppressed most crustaceans and rotifers while increasing gross and net primary production and chlorophyll concentration. SC had less intense effects on zooplankton than SG. Although SC suppressed most crustaceans and rotifers, it had less interaction effects than SG. SC had no statistically significant effects on phytoplankton production or chlorophyll concentration. It is suggested that these experiments indicate that although the plankton community impacts of SG and SC do differ, both fishes utilize similar food resources in Lake Kinneret. Fingerlings of SG and SC are planted in Lake Kinneret annually aimed at the improvement of fishermen’s income and prevention of water quality deterioration. SC is known as efficient consumer of Microcystis. It is therefore recommended to limit SC introduction to periods when Microcystis is abundant.

R/S Analysis and its Application in the Forecast of Mine Inflows

In this paper, the status quo and modeling principles of R/S analysis of non-linear theory are introduced and reviewed. Given the hydro-geological conditions of the Wutongzhuang coal mine, Hurst exponents of mine inflow for the main shaft, venti- lating shaft and auxiliary shaft were obtained using R/S analysis, which are 0.772 0, 0.824 7 and 0.905 1 respectively. Since all of the three Hurst exponents are larger than 0.5, it can be concluded that the trend of mine inflow are a long-term as well as persistent problem. Based on the level of duration, the shafts can be listed in decreasing order as the auxiliary shaft, the ventilation shaft and the main shaft, which appears identical with the actual situation of the mine inflow. With R/S analysis, a new method for long-term forecasting of mine inflows is provided.

Distribution and diversity of microbial communities in meromictic soda Lake Doroninskoe(Transbaikalia,Russia) during winter

Meromictic soda and saline lakes are unique ecosystems characterized by the stability of physical,chemical and biological parameters,and they are distributed all over the world.Lakes located in regions with average annual negative air temperature are of particular interest because of the presence of two periods with intensive and dynamic processes:the so-called biological summer and the long ice season with the biological spring.Soda Lake Doroninskoe is located in Eastern Transbaikalia(51°14′N,112°14′E) in the permafrost zone in an extreme continental climate,and is covered by ice for seven months per year.The structure and diversity of the microbial communities throughout the water column of the lake was studied by 16 S r RNA gene amplicon metasequencing.Different species with specific functions were found to dominate at different depths.Metabolically flexible bacteria with a capacity to switch between anoxygenic photosynthesis and aerobic chemotrophic metabolism dominate in soda Lake Doroninskoe.

Tectonic geomorphological characteristics for evolution of the Manas Lake

Owing to global climatic changes and human activities,the lakes have changed dramatically in the Junggar Basin of Xinjiang in recent 50 years. Based on the remote sensing images from Beijing Satellite No.1 in 2006 together with the measured topographical data in 1999 and other data since the 1950s,this paper analyzes mainly the features of landforms around the Manas Lake and the changes of feeding sources of the lake. The results are as follows:(1) Tectonic movement brought about the fundamental geomorphological basis for lacustrine evolution,and the Manas Lake is one of small lakes broken up from the Old Manas Lake due to tectonic movement and drought climate; the Manas Lake had existed before the Manas River flowed into it in 1915. The geomorphologic evidences for evolution of the Manas Lake include:(a) Diluvial fans and old channels at the north of the lake indicate that the rivers originating from the north mountains of the Junggar Basin had fed the Old Manas Lake and now still feed the lake as seasonal rivers; (b) The Old Manas Lake was fed by many rivers originating from the mountains,except for the Manas River,from the evidence of small lakes around the Manas Lake,old channels,alluvial fans,etc.; (c) The elevations of the alluvial and diluvial fans are near to the 280 m a.s.l. and all of the small lakes and lacustrine plains are within the range of the 280 m a.s.l.,which may prove that the elevation of the Old Manas Lake was about 280 m a.s.l.; (d) Core analysis of the Manas Lake area also indicates that the Manas Lake has existed since Late Pleistocene epoch. (2) Analysis on the feeding relations between the lakes and the lacustrine evolution shows that human activities are one of main driving forces of the lacustrine evolution in recent 50 years,and it is the precondition of restoring and maintaining the lacutrine wetlands in the study area to satisfy the feeding of the Baiyang and Manas rivers to the Manas Lake.

Characterization of depth-related microbial communities in lake sediment by denaturing gradient gel electrophoresis of amplified 16S rRNA fragments

The characterization of microbial communities of different depth sediment samples was examined by a culture-independent method and compared with physicochemical parameters, those are organic matter （OM）, total nitrogen （TN）, total phosphorus （TP）, pH and redox potential （Eh）. Total genomic DNA was extracted from samples derived from different depths. After they were amplified with the GC-341 f/907r primer sets of partial bacterial 16S rRNA genes, the products were separated by denaturing gradient gel electrophoresis （DGGE）. The profile of DGGE fingerprints of different depth sediment samples revealed that the community structure remained relatively stable along the entire 45 cm sediment core, however, principal-component analysis of DGGE patterns revealed that at greater sediment depths, successional shifts in community structure were evident. The principle coordinates analysis suggested that the bacterial communities along the sediment core could be separated into two groups, which were located 0-20 cm and 21-45 cm, respectively. The sequencing dominant bands demonstrated that the major phylogenetic groups identified by DGGE belonged to Bacillus, Bacterium, Brevibacillus, Exiguobacterium, γ-Proteobacterium, Acinetobacter sp. and some uncultured or unidentified bacteria. The results indicated the existence of highly diverse bacterial community in the lake sediment core.

Phylogenetic Diversity of Microorganisms from Chemocline of the Meromictic Soda Lake Doroninskoe(Zabaikalie,Russia)

1 Introduction Many soda and salt lakes are characterized by the formation of the meromictic conditions under which a part of the water column is not involved in the annual process of mixing(Mac Intyre,Melack,1982).This creates an

The World's Salt Lakes:Today and Tomorrow

The 12th International Conference on Salt Lake Research,which is organized jointly by International Society of Salt Lake and The Institute of Mineral Resources,Chinese Academy of Geological Sciences,will be held on July 14–18,2014 in Langfang,Hebei Province,China.The conference themes focus on future and global salt lake sustainable research and development and will bring together international specialists in limnology,sedimentology,geology,geochemistry,biology,

Assessment of Water Losses from Badovc Lake, Kosovo： Hydrochemical Implications

This paper aims to quantitatively assess water losses of Badovc Lake-Kosovo based on both water balance of the lake and water hydrochemistry. This attempt was strongly prompt by both the importance of this lake for water supply of Prishtina city and the lack of water. According to lake water balance, a water loss of 3,738,905 m^3 and 1,722,552 m^3 for the hydrologic year 2014 and the period January-May （2015） was evaluated. These consistent data favour the opinion that a continuous groundwater outflow from the lake is present and it is conditioned by the intensively developed fracture system in the lake basement formations. This was also supported by the chemical data （chloride, sulphate, hardness and electric conductivity etc.） of the water. Water from the leakages on the right side of the dam shows the same chemical signature as the water from the lake. Whereas, water from the piezometer, monitoring well and the gallery of Hajvalia mine show similar values with those of the water from the lake. The calculations of the chloride mass balance showed that the fractions of lake and rainfall waters in the water mixture of Hajvalia mine were 67% and 33% respectively.

Vertical Distribution of Bacteria in Doroninskoe Lake(Zabaikalie,Russia):Paradigm of Dominance

1 Introduction Prokaryotes are key organisms in aquatic ecosystems as they play animportant role in the biogeochemical cycling of elements.Investigations on the relationships betweenthe diversity of microbial community and environmentalfactors offer useful information that bothleads to understanding of the process of element

R/S Analyses of Some Geochemical Indexes for Tianshuihai Lake Core in West Kunlun Mountain and Their Environmental Implications

With the decrease of global temperature, glacial epoch came over the earth and global climate fluctuated over a great range since the beginning of Quaternary. Paleoclimotologists of various countries have focussed attention to the periodic characteristics and dynamics of climatic fluctuation in the past many years (Berger, 1977; Imbrie and Hays, 1984; Ding Zhongli et al., 1990; Yu Zhiwei et al., 1992; Liu Youmei et al., 1996). Although some of the workers have paid their attention to the nonlinear characteristics of the global Quaternary environmental evolution (Nicolis and Nicolis, 1984; Lu Houyuan et al., 1993), it is worth while to do this kind of work in some special areas in the world, for example the Qinghai\|Tibet Plateau.\; Using R/S analysis, the authors calculated the Hurst indexes H of some geochemical proxies, including organic carbon, FeO, Fe\-2O\-3 and FeO/ Fe\-2O\-3, from the Tianshuihai Lake core in West Kunlun Mountain of the Qinghai\|Tibet Plateau. The proxies satisfy the Hurst law with H\-\{org.carbon\}=0.735, H\-\{Fe\-2O\-3\}=0.757, H\-\{FeO\}=0.848 and H\-\{FeO/Fe\-2O\-3\}=0.646. All the indexes are greater than 0.5, meaning that from 240 to 15 ka B.P., there were some long\|run dependencies\|persistence in the climatic and environmental evolution around the Tianshuihai Lake area. This is in accordance with the climate there from 240 to 15 ka B.P. (Yu Suhua et al., 1996). The paleo\|climate and paleo\|environment evolution around the Tianshuihai Lake area is of persistence as well as of fluctuation and is a combination of these two components. There are some differences between the four Hurst indexes, which probably resulted from the different intensities of persistence of the four proxies, organic carbon, FeO, Fe\-2O\-3 and FeO/ Fe\-2O\-3, or from the change of drainage system around the Tianshuihai Lake area from openness to closeness(Li Bingyuan et al., 1991; Sun Honglie, 1996; Shi Yafeng et al., 1998).\; The Qinghai\|Tibet plateau was the starter and sensor of the climatic and environmental variation of the surrounding areas (Yao Tandong et al., 1991; Feng Song et al., 1998) and some other scientists even regarded it as the driver and amplifier of global climatic variations (Pan Baotian and Li Jijun, 1996). The persistence in which the climate and environment around the Tianshuihai Lake area evolved from 240 to 15 ka B.P. is probably a function of the continuous uplift of the plateau in the same period of time.

Hengshui Lake China’s Key Wetland Nature Reserve

WETLAND, an important eco-logical sys-tem, is of inestimable scientific, ecological, social and economic value. Bestowed liberally with nature’s bounty, China boasts various types of wetland, and during the past years has built over 130 wetland nature reserves, of which ten percent are

Impact of Water Deterioration on Growth Indices and Meat Quality of Tilapia zillii and Solea aegyptiaca Fish Inhabiting Lake Qaroun, Egypt

The present work studies water deterioration, fish survival and production as a result of effluents discharged directly without prior treatments into lake Qaroun at Fayoum governorate, Egypt. Lake Qaroun represents heavily polluted wild habitat for both studied fish species, Tilapia zillii and Solea aegyptiaca, the most abundant species. Results revealed deterioration in water quality (low dissolved oxygen but high ammonia, nitrite, copper, lead and cadmium) of Northeastern sector where El-Bats drain discharge its effluents without prior treatment followed by that of eastern sector at four km from the point of El-Bats discharge. Water salinity and dissolved oxygen values were in the following order: Western lake Qaroun sector > Eastern lake Qaroun sector > Northeastern lake Qaroun sector. However, Ammonia and nitrite readings were in the following order: Northeastern sector of Lake Qaroun is followed by the Eastern sector, then the Western sector. Moreover, results of the present field study revealed a decrease in fish production with the lowest condition factor and a deterioration in meat quality (an increase in muscle water content and ash but a decrease total protein and total lipids) in case of fish collected from the polluted sites along the lake (Northeastern and eastern sectors). However, fish collected from the unpolluted western sector of the lake showed condition factor and chemical muscle composition more or less similar to normal healthy fish.

EXPLOITATION & DEVELOPMENT OF CHINA'S SALT LAKE RESOURCES

This article recounts the current state of the research, developmemt and exploitation of the salt-lake resources in China’s hinterland with emphasis placed on those in Qinghai Province. It suggests that R&D input in and exploitation of the resources be stepped up, as this is of vital significance in boosting the regional economy of northwest China.

Restless Hot Money Inflows May Worsen China's Inflation Risk

A Chinese political advisor on Saturday warned a continued over- expectation for the appreciation of the Chinese currency Yuan would bring in more inflows of hot money and worsen the already excessive liquidity.

LITHIUM RESOURCES IN CHINA'S SALT LAKES & ITS SUSTAINABLE DEVELOPMENT

This article gives an introductory exposition of the growing demands of lithium on the market against the background of current rapid S&Tprogress and booming economic development, the worldwide trend in the production of lithium salts and the rich lithium reserves in China’s salt lakes as well as the brilliant prospects for its exploitation in the future. The article proposes that a sustainable exploitation of the lithium trove from these salt lakes should be rooted in comprehensive utilization of the trove and take a long-term approach, emphasizing high value proliferation in developing quality lithium-based products. Also, it expresses some tentative ideas on building demonstration bases for all-round exploitation and utilization of the salt lake resources and the development of lithium cells.