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1.
This article deals with the interaction of zinc with δ-MnO2,γ-MnOOH and manganite existing in natural water systems. The mechanism of the reaction has been studied in detail. From the fact that the "ratio of ion exchange (%)-pH" graph is an "S shaped" curve, it is possible to deduce that the chemical reaction is of the nature of cation exchange. And since the pH range of ion exchange = 4, it is possible to further deduce that the reaction can be explained by the mechanism of monovalence cation exchange.The main result of this article is the discovery of a new type of isotherm which has not been mentioned in previous literature here and abroad. This isotherm cannot be represented by any presently available adsorption isotherm equations in marine chemistry. The characteristics of this new type of isotherm are as follows: the isotherm has two "knees" and three "plateaus", the heights of these three "plateaus" are in the ratio 1:2:3. In order to explain theoretically our new isotherm, this article suggest  相似文献   

2.
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3.
This article introduces one of South Asia＇s most important border regions into academic discourse, namely, the Central Himalayan mountain rim separating India and the Tibetan Autonomous Region （People＇s Republic of China）. What makes this border region so interesting is a tangled interplay of changing environmental, cultural, and political forms to which the local populations constantly have to adapt in order to make a living there. We focused on the so-called ＇Bhotiyas＇ of Uttarakhand, former trans- Himalayan traders whose ethnicity and livelihood was traditionally associated with the Indo-Chinese border that was sealed as a result of the India-China war in 1962. Drawing on the work of borderland scholarship, we identified the key processes and developments that changed the perspective of this area. Competing political aspirations as well as the ＇Bhotiyas＇ countervailing strategies were considered equally important for understanding local livelihoods and identities within the dynamics of a ＇high mountain border region＇. Through an exemplary analysis of historical differences of power in one ＇Bhotiya＇ valley, we further explored the ways in which shifting socio-spatial constellations are creatively re-interpreted by the borderlanders.  相似文献   

4.
The important effects of snow cover to ground thermal regime has received much attention of scholars during the past few decades. In the most of previous research, the effects were usually evaluated through the numerical models and many important results are found. However, less examples and insufficient data based on field measurements are available to show natural cases. In the present work, a typical case study in Mohe and Beijicun meteorological stations, which both are located in the most northern tip of China, is given to show the effects of snow cover on the ground thermal regime. The spatial(the ground profile) and time series analysis in the extremely snowy winter of 2012–2013 in Heilongjiang Province are also performed by contrast with those in the winter of 2011–2012 based on the measured data collected by 63 meteorological stations. Our results illustrate the positive(warmer) effect of snow cover on the ground temperature(GT) on the daily basis, the highest difference between GT and daily mean air temperature(DGAT) is as high as 32.35℃. Moreover, by the lag time analysis method it is found that the response time of GT from 0 cm to 20 cm ground depth to the alternate change of snow depth has 10 days lag, while at 40 cm depth the response of DGAT is not significant. This result is different from the previous research by modeling, in which the response depth of ground to the alteration of snow depth is far more than 40 cm.  相似文献   

5.
The effect of tourism on water environments has received a high degree of interest in the study of eco-tourism.Based on the analysis of the relationship between tourist activities and the water environment in the Liupan Mountain eco-tourism zone,the case study area,a Water Environment of Tourism Area Model（WETAM） is built to simulate the temporal and spatial changes in water quality and the response saturation thresholds under four sewage treatment scenarios.The results imply the following：（1） WETAM performs well in modeling a water environment to represent the dynamic process of water quality change in response to tourist activities.（2） Under four sewage treatment scenarios（fundamental,low,medium,and high）,the threshold shows an obvious uptrend.（3） The response threshold of water quality with respect to the interference of tourist activities fluctuates seasonally due to changes in tourist density.（4） The thresholds differ significantly among five tourism functional areas.According to the response saturation threshold of the water environment,effective control based on the scale and intensity of tourist activities is important for a successful transformation of this tourism destination＇s development strategies.Therefore,the integrated management of water pollution in tourism areas plays a crucial role in sustainable tourism development.  相似文献   

6.
Russian researchers reach subglacial Lake Vostok in Antarctica   总被引：2，自引：0，他引：2  
Opening a new scientific frontier lying under the Antarctic ice, Russian researchers have drilled down and finally reached the surface of the gigantic freshwater lake, Lake Vostok. The mission chief likened the achievement to placing a man on the moon. Drilling in the area of the lake began 22 years ago in 1990, but progressed slowly as a result of funding shortages, equipment breakdowns, difficulties of drilling in the ＂warm＂ ice, and environmental concerns. In 1996, six years after drilling was started, a group of Russian and British scientists discovered the lake believed to be one of the largest fresh water reservoirs on the planet. This lake is among the last unexplored places on Earth. Sealed from the Earth＇s atmosphere for millions of years, it may provide vital information about microbial evolution, the past climate of the Earth, and the formation of the Antarctic ice sheet. Russian experts waited several years for international approval of their drilling technology before proceeding. As anticipated, lake water under pressure rushed up the borehole, pushing the drilling fluid up and away, then froze, forming a protective plug that prevented contamination of the lake. In December of the next Antarctic season, 2012--2013, researchers plan to re-drill the frozen sample of subglacial water for analysis.  相似文献   

7.
In this paper a new method is developed to make a dynamic layout adjustemnt and navigation for enter-prise Geographic Information System(GIS) based on object mark recognition.The extraction of object mark images is based on some morphological structural patterns,which are described by morphological structural points,contour prolpety,and other geometrical data in a binary image of enterprise geographic information map.Some pre-processing methods,contour smooth following,linearization and extraction patterns of structural points,are introduced If any special object is selected to make a decision is a GIS map ,the all information around it will be obtained.That is ,we need to investigate similar object enterprises around selected region to analyse whether it is necessary for establishing the object enterprise at that place.To further navigate GIS map,we need to move from one region to another,Each time a region is formed and displayed based on the user‘s focus,If a focus point of a map is selected,in terms of extracted object mark image,a dynamic layout and navigation diagram is constructed.When the user changes the focus (I.e.click a node in the navigation mode),a new sub-diagram is formed by dropping old nodes and adding new nodes,The prototype system provides effective interfaces that support GIS image navigation,detailed local image/map viewing,and enterprise information browsing.  相似文献   

8.
Uttarakhand state in India is well known for its mountainous ecosystems,traditional communities and a variety of ecotourism destinations.Among various tourism activities,River Rafting along the banks of the Ganges River has increased tremendously for two decades,and has had unprecedented impacts on the traditional communities and the bio-diversity.Therefore,it is meaningful to do a comprehensive study on the various impacts associated with river rafting so as to suggest the pathways to achieve the environmental sustainability in this region.In this study,we collected primary data from randomly selected population units across all stake holders such as local people(n = 100),and camp personnel(n = 22),through a pre-tested questionnaire survey between August 2009 and May 2010.The questionnaire contains issues on culture,social,economic,institutional and associated perceived impacts on pollution and biodiversity including views for sustainability.Secondary information was also collected from various sources and government records to supplement and strengthen the analysis.The impacts were analyzed qualitatively through a ranking mechanism to facilitate the decision making process.The perception of the interviewee about the various possible impacts of rafting was discussed with mitigating mechanism.The ranking analysis as percollected data reveals that economy and education of local community was improved significantly;however aquatic and terrestrial fauna,social cohesion and pollution(water,air,land) were significantly deteriorated.The results show that the existing practices are not sufficient to address the adverse impacts.Improvement in practices is necessary,mainly in the policy regime.Based on the analysis,some measures are recommended on how to protect community interest and environment with the development of river rafting as an ecotourism opportunity.  相似文献   

9.
Based on Hagget's theory of spatial structure,researches on the nodes and field of tourist origins to Huang-cheng Village in Shanxi Province of China have been explored.Nodal hierarchy structure of tourist origins is analyzed with cluster analysis and the gravity model.And field of tourist origins is analyzed with attraction radius index(R)and geography concentration index(G).In the field analysis,R and G of Huangcheng Village are compared with Xidi Village that is a world heritage located in Huangshan City of Anhui Province in China.According to comparison of loca-tions of two areas,influential factors for field area of Huangcheng Village are identified.It is concluded that:1)cluster analysis and gravity model can be complementary methods to each other for nodal hierarchy structure analysis of tour-ist origins;and 2)as far as location is concerned,the weak intensity effect of tourism resources in the tourist region is a major cause for explaining why tourist origins to Huangcheng Village are mainly its neighboring areas.Moreover,it is suggested that the regional effect of tourist resources should be regarded as a component of destination attractiveness when applying gravity model.  相似文献   

10.
This study emphasizes the advantage of tectonic phase separation in determination of a tectonic evolution of complicated fault zones. The research focused on the Sudetic Marginal Fault Zone(SMFZ) –a 250 km long active fault zone with documented intraplate seismicity situated on the NE margin of the Bohemian Massif(the Czech Republic). The tectonic history of the SMFZ as well as its kinematic development has been rather complicated and not quite understood. A field structural investigation was carried out in extensive surroundings of the fault zone. The fault-slip data were collected in a number of natural outcrops and quarries with the aim at establishing a robust and field-constrained model for local brittle structural evolution of the studied area. A paleostress analysis was calculated using the collected fault-slip data inversion. The T-Tecto software was utilized for semiautomatic separation of the paleostress phases. Simultaneously three methods of data separation were employed:(1) the Gauss inverse method,(2) the Visualization of Gauss object Function, and(3) the frequency analysis. Within the fault zone multiphase movements were observed on various types of faults as well as wide range of the kinematic indicators orientations. The frequency analysis confirmed the multiphase history of the SMFZ. The calculated tectonic phases were divided according to their relative age as constrained by cross cutting relationships and, where observed, multiple striations on a single fault plane and classified from the oldest to the younger. Data separation and inversion usingT-Tecto software with the Gauss inverse method revealed four different stress phases which are 3 strike-slip stress regimes and one compressional regime. The strike-slip regimes are characterized by σ1 trending NW-SE(43), NNE-SSW(18), ENE-WSW(76) and the compressional one by σ1 trending W-E(26). First, compression occurred parallel to the SMFZ supposedly during the Variscan period. Second, compression at an angle of 60° to general direction of the SMFZ yielded right-lateral movement along the fault zone. This is considered to have occurred during the late-Variscan and post-Variscan period. Third, compression in the W-E direction with almost vertical extension led to reverse movement along the fault zone. This is considered to have occurred during Cenozoic. Fourth, compression almost perpendicular to the SMFZ led to left-lateral transpression along the SMFZ. This is considered to have occurred during Quaternary.  相似文献   

11.
Formulation of different ecological zone plans according to the corresponding protection targets and the necessity of proper conservation policy is one of the measures to achieve the goal of ecological conservation in China.In order to clarify the interrelation among key ecological zone plans,this paper carried out the research on spatial relation of priority areas of biodiversity conservation and three key ecological areas（key ecological function areas,key regions of ecological service function,national nature reserves） and the research on ecological conditions,based on multi-scale ecological spatial theme information,which incorporates elements like ecologi-cal quality and type,and by the aid of spatial information analysis and GIS modeling.The results showed a contrastively fine spatial consistency with 68.8% of priority areas of biodiversity conservation overlapping with three key ecological areas.Although the envi-ronment in priority areas of biodiversity conservation were in good conditions,protection pressure is also increasing,powerful supervi-sion and protection should not be ignored.The environmental conditions in the overlapping areas,as a whole,were superior to those in the non-overlapping areas.Since two areas have different characteristics,targeted protection measures should be formulated based on this difference,which will be very important for biodiversity conservation in priority areas of biodiversity conservation.  相似文献   

12.
Only simplified two-dimensional model and a single failure mode are adopted to calculate the ultimate pullout capacity(UPC) of anchor cables in most previous research. This study focuses on a more comprehensive combination failure mode that consists of bond failure of an anchorage body and failure of an anchored rock mass. The three-dimensional ultimate pullout capacity of the anchor cables is calculated based on the Hoek-Brown failure criterion and variation analysis method. The numerical solut...  相似文献   

13.
Dynamic response analysis of a floating mooring system   总被引：1，自引：0，他引：1  
An innovative floating mooring system with two or more independent floating mooring platforms in the middle and one rigid platform on each side is proposed for improving efficiency and safety in shallow water. For this new system, most of collision energy is absorbed through the displacement of floating platforms. In order to illustrate the validity of the system, a series of model tests were conducted at a scale of 1:40. The coupled motion characteristics of the floating mooring platforms were discussed under regular and irregular waves, and the influences of wave direction and other characteristics on dynamic response of the system were analyzed. The results show that the mooring system is safest at 0° of wave incident angle, whereas the most dangerous mooring state occurs at 90° of wave incident angle. Motion responses increase with the increase of wave height, but are not linearly related to changes in wave height.  相似文献   

14.
Using political ecology as its conceptual framework, this paper focuses on the changes in forest utilisation and management of South Kyrgyzstan＇s walnut-fruit forests over the last century The aim of this study on human-environment interactions is to investigate the relationship between actors on the one side, their interests and demands, and the forests and forested lands on the other. Forest resource utilisation and management - and even the recognition of different forest products as resources - are connected with political and socioeconomic conditions that change with time. The walnut-fruit forests of South Kyrgyzstan are unique, characterised by high biodiversity and a multiplicity of usable products; and they have been utilised for a long time. Centralised and formal management of the forests started with the Russian occupation and was strengthened under Soviet rule, when the region became a part of the USSR. During this era, a state forest administration that was structured from Moscow all the way down to the local level drew up detailed plans and developed procedures for utilising the different forest products. Since the collapse of the Soviet Union, the socio-political and economic frame conditions have changed significantly, which has brought not only the sweeping changes in the managing institutions, but also the access rights and interests in the forest resources. At present, the region is suffering from a high unemployment rate, which has resulted in the forests＇ gaining considerable importance in the livelihood strategies of the local population. Political and economic liberalization, increased communication and transregional exchange relations have opened the door for international companies and agents interested in the valuable forest products. Today, walnut wood and burls, walnuts, wild apples and mushrooms are all exported to various countries in the world. Scientists and members of various international organisations stress the ecological value of the forests and are trying to establish nature conservation areas. Nevertheless, it is to fear that a multiplicity of interrelated factors - the present transformation and globalization processes, the appearance of new actors, the local population＇s insecure economic situation and the erosion of managing institutions - are all leading to an intensified and unregulated exploitation of the forests, resulting in their degradation.  相似文献   

15.
Based on the characteristic of ＇one river one oasis＇ in the arid areas, the Yerqiang River Basin, which is the largest irrigated area of Xinjiang, is taken as an example in this paper, and the regional water circulation pattern is investigated through the analysis of 60 groups of isotope data in the basin. From the phreatic evaporation data analysis of different soils, we study the law of phreatic evaporation, complete the research of the main consumption path of the groundwater, and improve the assessment precision of water resources. The transformation mount of regional water resources are predicted by calculation, which provides a scientific basis for water resources assessment and allocation in arid regions, and offers a new method for the study of regional water circulation patterns.  相似文献   

16.
The thermodynamic properties of snow cover on sea ice play a key role in the ice-ocean-atmosphere system and have been a focus of recent scientific research. In this study, we investigated the thermodynamic properties of snow cover on sea ice in the Nella Fjord, Prydz Bay, East Antarctica(69°20′S, 76°07′E), near the Chinese Antarctic Zhongshan Station. Our observations were carried out during the 29th Chinese National Antarctic Research Expedition. We found that the vertical temperature profile of snow cover changed considerably in response to changes in air temperature and solar radiation during the summer. Associated with the changes in the temperature profile were fluctuations in the temperature gradient within the upper 10 cm of the snow cover. Results of previous research have shown that the thermal conductivity of snow is strongly correlated with snow density. To calculate the thermal conductivity in this study, we measured densities in three snow pits. The calculated thermal conductivity ranged from 0.258–0.569 W?m-1?K-1. We present these datasets to show how involved parameters changed, and to contribute to a better understanding of melting processes in the snow cover on sea ice.  相似文献   

17.
Landslide susceptibility mapping is the first step in regional hazard management as it helps to understand the spatial distribution of the probability of slope failure in an area.An attempt is made to map the landslide susceptibility in Tevankarai Ar subwatershed,Kodaikkanal,India using binary logistic regression analysis.Geographic Information System is used to prepare the database of the predictor variables and landslide inventory map,which is used to build the spatial model of landslide susceptibility.The model describes the relationship between the dependent variable(presence and absence of landslide) and the independent variables selected for study(predictor variables) by the best fitting function.A forward stepwise logistic regression model using maximum likelihood estimation is used in the regression analysis.An inventory of 84 landslides and cells within a buffer distance of 10m around the landslide is used as the dependent variable.Relief,slope,aspect,plan curvature,profile curvature,land use,soil,topographic wetness index,proximity to roads and proximity to lineaments are taken as independent variables.The constant and the coefficient of the predictor variable retained by the regression model are used to calculate the probability of slope failure and analyze the effect of each predictor variable on landslide occurrence in thestudy area.The model shows that the most significant parameter contributing to landslides is slope.The other significant parameters are profile curvature,soil,road,wetness index and relief.The predictive logistic regression model is validated using temporal validation data-set of known landslide locations and shows an accuracy of 85.29 %.  相似文献   

18.
With trends indicating increase in temperature and decrease in winter precipitation, a significant negative trend in snow-covered areas has been identified in the last decade in the Himalayas. This requires a quantitative analysis of the snow cover in the higher Himalayas. In this study, a nonlinear autoregressive exogenous model, an artificial neural network （ANN）, was deployed to predict the snow cover in the Kaligandaki river basin for the next 30 years. Observed climatic data, and snow covered area was used to train and test the model that captures the gross features of snow under the current climate scenario. The range of the likely effects of climate change on seasonal snow was assessed in the Himalayas using downscaled temperature and precipitation change projection from - HadCM3, a global circulation model to project future climate scenario, under the AIB emission scenario, which describes a future world of very rapid economic growth with balance use between fossil and non-fossil energy sources. The results show that there is a reduction of 9% to 46% of snow cover in different elevation zones during the considered time period, i.e., 2Oll to 2040. The 4700 m to 52oo m elevation zone is the most affected area and the area higher than 5200 m is the least affected. Overall, however, it is clear from the analysis that seasonal snow in the Kaligandaki basin is likely to be subject to substantialchanges due to the impact of climate change.  相似文献   

19.
Studying the relationship between wave steepness and wave age is important for describing wind wave growth with energy balance equation of significant waves. After invoking the dispersion rela- tion of surface gravity wave in deep water, a new relationship between wave steepness and wave age is revealed based on the “3/2-power law” (Toba, 1972), in which wave steepness is a function of wave age with a drag coefficient as a parameter. With a given wave age, a larger drag coefficient would lead to larger wave steepness. This could be interpreted as the result of interaction between wind and waves. Comparing with previous relationships, the newly proposed one is more consistent with observational data in field and laboratory.  相似文献   

20.
Extreme waves have a profound impact on coastal infrastructure; thus, understanding the variation law of risky analysis and disaster prevention in coastal zones is necessary. This paper analyzed the spatiotemporal characteristics of extreme wave heights adjacent to China from 1979 to 2018 based on the ERA5 datasets. Nonstationary extreme value analysis is undertaken in eight representative points to investigate the trends in the values of 50-and 100-year wave heights. Results show that the mean ...  相似文献   

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