The Tibetan Plateau has a large number of hot springs with varying temperatures and hydrochemistry,high elevation,and limited nitrogenous nutrition.Nitrogen-fixing bacteria(NFB)can fix N_(2)to form ammonia and thus pr...The Tibetan Plateau has a large number of hot springs with varying temperatures and hydrochemistry,high elevation,and limited nitrogenous nutrition.Nitrogen-fixing bacteria(NFB)can fix N_(2)to form ammonia and thus provide bioavailable nitrogen.However,there is limited knowledge about the distribution of NFB and its influencing factors in Tibetan hot springs.Here,we measured hydrochemical variables of the hot springs with a wide temperature range(32–77°C)in the Qucai and Daggyai geothermal zones on the Tibetan Plateau and investigated the composition of NFB using high-throughput sequencing of 16SrRNA and nif H genes.The Cl^(-)/SO_(4)^(2-)ratio in Qucai hot springs was higher than that in Daggyai,indicating that Qucai and Daggyai hot springs were more affected by the supply of liquid and gaseous phases,respectively.The NFB communities consisted predominantly of Nirtospirae,Chloroflexi,Deltaproteobacteria and an unidentified clade,with the last three acting as the main NFB with over 42%of the communities(the proportions are significantly larger than those found in hot springs of other geothermal regions).This demonstrates the uniqueness of NFB communities in Tibetan hot springs.NFB richness was limited by temperature in the studied Tibetan hot springs and was significantly lower than in low-elevation geothermal regions.The NFB community was predominantly affected by hydrochemistry,in contrast to the entire prokaryotic community,which was primarily influenced by temperature.This study expands our current understanding of NFB distribution and diversity as well as biogeochemical process in geothermal spring environments.展开更多
Based on tourist resources' evaluation and tourism market development of Huangshan Hot Spring Scenic Area,by combining with relevant theories of "SWOT",the paper has identif ied the leading functional or...Based on tourist resources' evaluation and tourism market development of Huangshan Hot Spring Scenic Area,by combining with relevant theories of "SWOT",the paper has identif ied the leading functional orientation and tourism development idea of the hot spring scenic area.Meanwhile,by following the principle of "sustainable use" of Huangshan natural resources,planning strategies and implementing suggestions have been put forward based on "addition,subtraction,multiplication and division".The ultimate purpose is to create diversified tourism experiences for tourists and improve tour quality of hot spring scenic area,and f inally build Huangshan tourism brand of "Snowy Hot Spring".展开更多
The basic situation and formation mechanism of hot spring in Liaocheng were introduced,and its utilization value as well as exploitation and utilization status were also analyzed in this study,which provided strategie...The basic situation and formation mechanism of hot spring in Liaocheng were introduced,and its utilization value as well as exploitation and utilization status were also analyzed in this study,which provided strategies for exploitation and utilization of hot spring in Liaocheng.展开更多
Tourist's satisfaction degree is one of the important indexes to evaluate the service quality of scenic spot.Taking Xi'an Dongda Hot Spring Resort Area for an example,with the expectation difference theory and...Tourist's satisfaction degree is one of the important indexes to evaluate the service quality of scenic spot.Taking Xi'an Dongda Hot Spring Resort Area for an example,with the expectation difference theory and customers' satisfaction evaluation model as the theoretical basis of the research,the overall satisfaction degree of tourists to hot spring resort area,and the actual sensation accomplishments and the expectation difference of each service index were analyzed by using regression analysis and paired sample t test method.The results showed:① The overall satisfaction degree of tourists to the resort area was higher.There were remarkable correlation among three variables:the sensation value,the overall satisfaction degree,and the tourist's loyalty degree;② Generally,the sensation actual accomplishments of 15 service appraisal factors were higher than the expectation value.According to the characteristics,these 15 service appraisal factors were divided into 5 groups.Some unsatisfactory aspects were found out,and the corrective measures were put forward.展开更多
The paper had introduced geographic causes and types of hot springs, illustrated its disease-treating function and displayed its great vitality and widespread development prospect as tourist resources. By taking Shawa...The paper had introduced geographic causes and types of hot springs, illustrated its disease-treating function and displayed its great vitality and widespread development prospect as tourist resources. By taking Shawan Hot Spring in Xinjiang for example, the paper had analyzed its natural condition, hot springs and tourist economic development. And then, quantitative and qualitative analysis had been conducted on the quality of water environment resources in the research area. It had analyzed reasons for degeneration of water environment and studied exploitation and sustainable development of hot springs. It was considered that environment especially water environment quality had decreased since hot spring tourism development. In order to achieve sustainable development of hot springs and promotion of local tourism, it must be guided by environment treatment, and some strategies for sustainable development of hot springs had been proposed.展开更多
Taking Xingzi hot spring in Jiangxi for an example and tourist behaviors of hot-spring tourism as the research object,tourist behaviors and psychological feelings were analyzed in this study to discuss the sustainable...Taking Xingzi hot spring in Jiangxi for an example and tourist behaviors of hot-spring tourism as the research object,tourist behaviors and psychological feelings were analyzed in this study to discuss the sustainable Development Countermeasures of hot-spring tourism.展开更多
The Tengchong geothermal area,an active tectonic region with frequent earthquakes,is located in Yunnan Province of southwestern China.This area contains abundant active hot springs, which often display high metal conc...The Tengchong geothermal area,an active tectonic region with frequent earthquakes,is located in Yunnan Province of southwestern China.This area contains abundant active hot springs, which often display high metal concentrations and obvious mineralization phenomena.At 19：19 on 9 July 2009,an earthquake occurred in Yao＇an,Chuxiong,Yunnan Province,which is 300 km to the northeast of the Tengchong geothermal area.We sampled water in the hot springs in the Tengchong area from 4 July to 9 July 2009 and from 10 July to 15 July 2009 to study the changes of elemental concentrations before and after the earthquake and discuss the influence of the earthquake on the mineralization of the hot springs.The concentrations of most trace elements increased slightly,but the concentration of REE（rare earth elements） decreased by 50%after the earthquake in the hot springs around a NS-trending fault.The elemental concentrations remained unchanged in Longtan and Suanshuigou,which are related to an inactive crater.The elemental concentrations in other springs controlled by superficial and small-scale faults decreased after the earthquake.The earthquake can stimulate the activity of deep faults and magma chambers,as is responsible for the increase of metal concentrations in the hot springs along the NS-trending deep fault;whereas it can decrease the porosity of permeable rocks,resulting in the decline of the flux of ore-bearing fluids and the corresponding mineralization in the hot springs related to superficial faults.展开更多
A slightly acidic hot spring named ＂Female Tower＂（t=73.5°C, pH=6.64） is located in the Jifei Geothermal Field, Yunnan Province, southwestern China. The precipitates in the hot spring are composed of large amo...A slightly acidic hot spring named ＂Female Tower＂（t=73.5°C, pH=6.64） is located in the Jifei Geothermal Field, Yunnan Province, southwestern China. The precipitates in the hot spring are composed of large amounts of calcite, aragonite and sulfur. Scanning electron microscopy（SEM） analyses reveal that the microbial mats were formed from various coccoid or rod-shaped filamentous microbes. Transmission electron microscopy（TEM） shows that the intracellular sulfur granules are commonly associated with these microbes. A culture-independent molecular phylogenetic analysis demonstrates that the majority of the bacteria in the spring are sulfur-oxidizing bacteria. In the spring water, H2S concentration is up to 60 ppm, while SO4-（2-） concentration is only about 10 ppm. We speculate that H2S might derive from sulfur-oxidizing bacteria in this hot spring water, leading to the intracellular formation of sulfur granules. Meanwhile, this reaction increased the p H in the micronscale microdomains, which fosters the precipitation of calcium carbonate in the microbial mats. The results of this study indicate that the sulfur-oxidizing bacteria might play an important role in calcium carbonate precipitation in slightly acidic hot spring environments.展开更多
Microbial mats, mainly dominated by filamentous algae Calothrix and Oscillatoria, are well developed in Tibetan hot springs. A great number of fossil microorganisms, which existed as algae lamination in thermal deposi...Microbial mats, mainly dominated by filamentous algae Calothrix and Oscillatoria, are well developed in Tibetan hot springs. A great number of fossil microorganisms, which existed as algae lamination in thermal depositional cesium-bearing geyserite in this area, are identified as Calothrix and Oscillatoria through microexamination and culture experiments. These microbial mats show the ability to accumulate cesium from spring water to the extent of cesium concentration of 0.46-1.03% cell dry weight, 900 times higher than that in water, and capture large numbers of cesium-bearing opal grain. Silicon dioxide colloid in spring water replaces and fills with the organism and deposits on it to form algae laminated geyserite after dehydration and congelation. Cesium in the microbial mats and opal grain is then reserved in the geyserite. Eventually, cesium-bearing algae laminated geyserite is formed. Study on cesium distribution in geyserite also shows that cesium content in algae lamination, especially in heavily compacted algae lamination, is higher than in the opal layer. For geyserite with no algae lamination or other organism structure, which is generally formed in spring water with low silicon content, cesium accumulation and cesium-bearing opal grain assembled by the microbial mats are also indispensable. After the microbial mats accumulating cesium from spring water, silicon dioxide colloid poorly replaces and fills with the organism to form opal grain-bearing tremellose microbial mats. The shape and structure of the organisms are then destroyed, resulting in cesium-bearing geyserite with no algae lamination structure after dehydration and congelation. It is then concluded that microbial mats in the spring area contribute to the enrichment of cesium in the formation of cesium-bearing geyserite, and a biological genesis of the geyserite, besides of the physical and chemical genesis, is likely.展开更多
Isoprenoidal glycerol dialkyl glycerol tetraethers （iGDGTs） from the Gulu hot springs （23--83.6 ℃, pH 〉 7） and Yangbajing hot springs （80-128 ℃, pH 〉 7） were analyzed in order to investigate the distribution...Isoprenoidal glycerol dialkyl glycerol tetraethers （iGDGTs） from the Gulu hot springs （23--83.6 ℃, pH 〉 7） and Yangbajing hot springs （80-128 ℃, pH 〉 7） were analyzed in order to investigate the distribution of archaeal lipids among different hot springs in Tibet. A soil sample from Gulu was incubated at different temperatures and analyzed for changes in iGDGTs to help evaluate whether surrounding soil may contribute to the iGDGTs in hot springs. The sources of bacterial GDGTs （bGDGTs） in these hot springs were also investigated. The results revealed different profiles ofiGDGTs between Gulu and Yangbajing hot springs. Core iGDGTs and polar iGDGTs also presented different patterns in each hot spring. The PCA analysis showed that the structure of polar iGDGTs can be explained by three factors and suggested multiple sources of these compounds. Bivariate correlation analysis showed significant positive correlations between polar and core bGDGTs, suggesting the in situ production of bGDGTs in the hot springs. Furthermore, in the soil incubation experiment, temperature had the most significant influence on concentration of bGDGTs rather than iGDGTs, and polar bGDGTs had greater variability than core bGDGTs with changing temperature. Our results indicated that soil input had little influence on the composition of GDGTs in Tibetan hot springs.展开更多
Hot springs are natural exposed points of the hydrothermal system. The hydrogeochemistry of hot springs can be used to interpret the formation of the hydrothermal system; and the ^(14)C dating can be used to evaluate ...Hot springs are natural exposed points of the hydrothermal system. The hydrogeochemistry of hot springs can be used to interpret the formation of the hydrothermal system; and the ^(14)C dating can be used to evaluate the renewability of the hydrothermal system. The hot springs exposed from fault zones in western Guangdong are classified as granite fissure water and clastic rock fissure water, which are sampled and tested. The results of water chemistry analysis show that hot spring water is mainly HCO_3-Na type in the beginning, while the mixing of seawater leads to the increase of Cl^-. Hydrogen and oxygen isotopes indicate that these hot springs mainly come from atmospheric precipitation, and water-rock interactions produce oxygen isotope exchange reactions, where a significant "oxygen drift" phenomenon can be observed. The relationship between δ^(13)C and HCO_3^- indicates that there is a deep source of CO_2 "dead carbon" in hot spring water. This systematic error is not considered in the existing ^(14)C dating correction models. The ^(14)C age of the deep source "dead carbon" correction proposed in this paper is close to the ^(14)C age of the reverse chemical simulation correction, the Gonfiantinie model, and the Mook model. The deep source "dead carbon" correction method can improve the systematic error. Therefore, the ^(14)C age corrected by the deep source "dead carbon" may be more representative in terms of the actual age of geothermal water.展开更多
A total of 69 strains of thermophilic bacteria were isolated from water, soil and sediment samples from three Indonesia's hot spring areas (Pantai cermin, Kalianda and Banyu wedang) by using Minimal Synthetic Medi...A total of 69 strains of thermophilic bacteria were isolated from water, soil and sediment samples from three Indonesia's hot spring areas (Pantai cermin, Kalianda and Banyu wedang) by using Minimal Synthetic Medium (MSM). The extreme thermophile Brevibacillus sp. PLI-1 was found to produce extracellular thermophilic alkaline protease with optimal activity at 70℃ and pH 8.0-9.0. The molecular weight of the protease was estimated to be around 56 kD by SDS-PAGE. The maximum activity of the protease was 26.54 U mL-1. The protease activity did not decrease after 30 min and still retained more than 70% of relative activity after 60 min at 70℃ and pH 8.0. The ion Mg2+ was found to promote protease activity at both low and high concentrations, whereas Cu2+ and Zn2+ could almost completely inhibit the activity. Divalent cation chelator EDTA inhibited the enzyme activity by 55.06% ± 0.27%, while the inhibition caused by PMSF, Leupeptin, Pepstain A and Benzamidine were 66.78% ± 3.25%, 52.37% ± 0.25%, 62.47% ± 2.96% and 50.99% ± 0.24%, respectively. Based on these observations, the enzyme activity was conspicuously sensitive to the serine and cysteine protease inhibitors. All these results indicated that the protease isolated from the strain PLI-1 was a thermophilic protease and had a high-temperature stability and a pH stability.展开更多
Electrocardiogram(ECG)electrodes are conductive pads applied to the skin to measure cardiac activity.Ag/AgCl electrodes are the commercial product which widely used to obtain ECGs.When monitoring the ECG in a hot spri...Electrocardiogram(ECG)electrodes are conductive pads applied to the skin to measure cardiac activity.Ag/AgCl electrodes are the commercial product which widely used to obtain ECGs.When monitoring the ECG in a hot spring,Ag/AgCl electrodes must be waterproofed;however,this is time-consuming,and the adhesive may tear the skin on removal.For solving the problem,we developed the carbon pencil lead(CPL)electrodes for use in hot springs.Both CPL and Ag/AgCl electrodes were connected to ECG100C’s cables.The Performance was evaluated in three conditions as following:hot spring water with and without bubble,and in cold water.In each environment,the procedure was followed by three different protocols that are recording from the dry condition,hot spring water immersion with and without movement,post hot spring water condition.Under dry and wet conditions,both electrodes can obtain the waveform of the ECG signal in which all PQRST waves were identifiable.Nevertheless,the signal quality of both types of electrodes was different in water immersion with and without movement.The overall morphology obtained by Ag/AgCl electrodes was unstable higher than that of CPL electrodes in immersion without movement condition.The CPL electrodes provided better ECG waveform quality compared to Ag/AgCl electrodes in which the ECG signal had high waveforms distortion in water immersion with movement condition.展开更多
Heredity in the microstructure and mechanical properties of hot-rolled spring steel wire 60Si2MnA during heat treatment process was investigated comprehensively. The steel was isothermally transformed to obtain variou...Heredity in the microstructure and mechanical properties of hot-rolled spring steel wire 60Si2MnA during heat treatment process was investigated comprehensively. The steel was isothermally transformed to obtain various hot-rolled microstructure （pearlite fineness within the range of 140-510 nm） and mechanical properties, and followed by some quenching-tempering treatment. Afterwards, microstructure was characterized by optical microscopy, scanning electron microscopy and quantitative metallography, and mechanical properties were determined by tensile test. The results indicated that the hot-rolled microstructure with a coarsen pearlite structure had been changed after reheating, to a austenite microstructure with bigger and more uneven grain size, and finally to a coarsen tempered microstructure. And the average austenite grain size and standard deviation of its distribution in quenched microstructure were observed to depend linearly on the interlamellar spacing in hot-rolled microstructure. Besides, to obtain a good combination of the final strength and plasticity, an optimum value range （190-280 nm） of the interlamellar spacing had been determined for the interlamellar spacing in hot-rolled microstructure.展开更多
The Gulf of Suez region is one of the most interesting geothermal areas in Egypt because of the high temperatures of its springs.The eastern and western shores of the Gulf of Suez are characterized by superficial ther...The Gulf of Suez region is one of the most interesting geothermal areas in Egypt because of the high temperatures of its springs.The eastern and western shores of the Gulf of Suez are characterized by superficial thermal manifestations including a cluster of hot springs with varied temperatures.Variations of deuterium and oxygen-18 concentrations in thermal waters have been used to aid in describing the source of recharge in the Gulf of Suez hot springs.Isotope and geochemical data for the Gulf of Suez thermal waters suggest that recharge to the hot springs may not be entirely from the Gulf of Suez water,but possibly from the meteoric water that comes from areas of higher altitude surrounding the hot springs.展开更多
Gas concentrations and isotopic compositions of He and CO2 were determined on free gas samples from ten hot springs of the Rehai geothermal field, Tengchong, China. The results showed that hot-spring CO2 gas, together...Gas concentrations and isotopic compositions of He and CO2 were determined on free gas samples from ten hot springs of the Rehai geothermal field, Tengchong, China. The results showed that hot-spring CO2 gas, together with He, was derived mainly from the mantle, indicating the accumulation of mantle-derived volatiles beneath the survey area. The δ 13C values of CO2, higher than those of the typical mantle-derived carbon and the isotopic composition of hot-spring-free CO2 in unequilibrium with dissolved CO2, are recognized only in the Rehai geothermal field, suggesting that there seems to be a still-degassing magmatic intrusion at depths, which provides mantle-derived volatiles to the hydrothermal system above. The accumulation of those volatiles has probably played an important role in triggering earthquakes in this region. In addition, the isotopic characteristics of He and C also indicate that the magmatic intrusion seems to have been derived from the MORB source, and could be contaminated by crustal materials during its upwelling through the continental crust.展开更多
Drinking water-type fluorosis is the most harmful endemic disease in China with the largest number of sufferers. Although the implementation of the policy to alter water sources to lower fluoride level has effectively...Drinking water-type fluorosis is the most harmful endemic disease in China with the largest number of sufferers. Although the implementation of the policy to alter water sources to lower fluoride level has effectively controlled the spread of this kind of endemic disease,its prevalence could not thoroughly be stopped because the high-fluoride environmental background in these endemically diseased areas could still do harm to human health through food chain. Therefore,it is necessary to conduct a more deep-going study on the drinking water-type fluoro-sis. To investigate the effect of high fluorine environmental background on crops and human health in the hot spring-type fluorosis-diseased areas,local water,paddy soil,rice,whole vegetables and soils around their roots were sampled for analysis. The results were compared with those of the control groups in fluorosis-free areas which are similar to the fluorosis-diseased areas both in natural background and in social background. It is indicated that rice and vegetables can accumulate water-soluble fluorine either in soils or in irrigating water,and different crops have different abilities of fixing fluorine. The contents of fluorine in different parts of vegetables in the fluorosis-diseased and fluorosis-free areas were statistically categorized. The results showed that the fluorine contents of roots,tubers,leaves and flowers of vegetables in the fluorosis-diseased areas are 3.56,1.17,3.07 and 3.23 mg/kg,respectively. However,comparisons showed that in the fluorosis-free areas,the fluorine contents are 2.17,0.70,1.91 and 2.52 mg/kg,respectively. Moreover,different parts of a crop also show significantly different fluorine fixation abilities. It is demonstrated that the fluorine contents of the strongly metabolic parts are relatively high. For example,the fluo-rine contents of roots,leaves and flowers of vegetables are much higher than those of stems. The fluorine fixation ability of seeds is very weak. In order to reduce the risk of human body’s exposure to fluoride,the impact of hot spring water on the capability of crops to fix fluorine should be reduced as much as possible. It is of great importance to prevent crops from being irrigated with hot spring water and it is advisable to grow crops with relatively low ca-pabilities to enrich fluorine,such as those with seeds or tubers as the main edible parts in the areas which are se-verely affected by hot spring water.展开更多
A type of high molecular weight bioactive polymers called exopolysaccharides(EPS)are produced by thermophiles,the extremophilic microbes that thrive in acidic environmental conditions of hot springs with excessively w...A type of high molecular weight bioactive polymers called exopolysaccharides(EPS)are produced by thermophiles,the extremophilic microbes that thrive in acidic environmental conditions of hot springs with excessively warm temperatures.Over time,EPS became important as natural biotechnological additives because of their noncytotoxic,emulsifying,antioxidant,or immunostimulant activities.In this article,we unravelled a new EPS produced by Staphy-lococcus sp.BSP3 from an acidic(pH 6.03)San Pedro hot spring(38.1℃)located in the central Andean mountains in Chile.Several physicochemical techniques were performed to characterize the EPS structure including Scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDS),Atomic Force Microscopy(AFM),High-Performance Liquid Chromatography(HPLC),Gel permeation chromatography(GPC),Fourier Transform Infrared Spectroscopy(FTIR),1D Nuclear Magnetic Resonance(NMR),and Thermogravimetric analysis(TGA).It was confirmed that the amorphous surface of the BSP3 EPS,composed of rough pillar-like nanostructures,is evenly distributed.The main EPS monosaccharide constituents were mannose(72%),glucose(24%)and galactose(4%).Also,it is a medium molecular weight(43.7 kDa)heteropolysaccharide.NMR spectroscopy demonstrated the presence of a[→6)-α-d-Manp-(1→6)-α-d-Manp-(1→]backbone 2-O substituted with 1-α-d-Manp.A high thermal stability of EPS(287°C)was confirmed by TGA analysis.Emulsification,antioxidant,flocculation,water-holding(WHC),and oil-holding(OHC)capacities are also studied for biotechnological industry applications.The results demonstrated that BSP3 EPS could be used as a biodegradable material for different purposes,like flocculation and natural additives in product formulation.展开更多
Background: Use of novel microorganisms for beneficial purposes is still remaining a challenging job. This study was designed to isolate, characterize and use of a novel hot spring bacterial strain from a virgin hot s...Background: Use of novel microorganisms for beneficial purposes is still remaining a challenging job. This study was designed to isolate, characterize and use of a novel hot spring bacterial strain from a virgin hot spring of Metaldanga, Birbhum, West Bengal, India. Methods: A pure bacterial strain (MDH1) was identified by growing the enrichment culture isolated from Metaldanga hot spring through serial dilution process in a semi-synthetic medium at pH 8.0 and 42°C temperature. The novelty of the strain was characterized by 16S-rRNA gene sequence analysis. The bacterium acted as template to synthesize spherical gold nanoparticles (GNPs). GNPs were characterized by using UV-Vis spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS) and Fourier transform infra-red spectroscopy (FTIR). Results: The phylogenetic analysis suggested that MDH1 strain (GenBank accession number: KT600031) was affiliated to the family “Pseudomonadaceae” with 99% homologous to Pseudomonas putida H8234. The coccoid shaped bacterium was gram-negative and facultative-anaerobic which acted as a template to synthesize spherical GNPs with an average size of 12 ± 3 nm when examined under transmission electron microscopy (TEM). FT-IR studies revealed the presence of bioactive functional groups which acted as capping and stabilizing agents of the GNPs. XRD pattern confirmed the amorphous nature of GNPs. The Zeta potential (ζ) concluded the adequate stability of GNPs in an aqueous environment. Conclusions: The present investigation explores the microbial diversity of a virgin hot spring of Metaldanga for its beneficial applications in industry, particularly in the synthesis of the gold nanoparticles.展开更多
Chongqing Beiwenquan hot springs were continuously monitored from May 1 to July 4,2008,during the May 12,2008 Ms 8.0 earthquake.On the spot in these hot springs were measured during this time. Chongqing Beiwenquan hot...Chongqing Beiwenquan hot springs were continuously monitored from May 1 to July 4,2008,during the May 12,2008 Ms 8.0 earthquake.On the spot in these hot springs were measured during this time. Chongqing Beiwenquan hot spring about 400 km away from Wenchuan Sichuan,had a huge response to the earthquake.After the earthquake,three higher elevation springs are cutoff,and the other four springs’ discharge has been increased nearly 50%. Temperature of these springs all reduced 1℃. Concentration of K<sup>+</sup>,Na<sup>+</sup>,Ca<sup>2+</sup> in these hot springs has been reduced,and has an excellent linear correlation.Concentration of Mg<sup>2+</sup> has been increased,Concentration of SO<sub>4</sub><sup>2-</sup>,F<sup>-</sup> has展开更多
基金supported by the National Natural Science Foundation of China(Nos.31300430,42172339,91951205)Key Scientific Research Project Plan of Colleges and Universities in Henan Province(No.18A180002)Science and Technology Research Project of Henan Province(No.152102310352)。
文摘The Tibetan Plateau has a large number of hot springs with varying temperatures and hydrochemistry,high elevation,and limited nitrogenous nutrition.Nitrogen-fixing bacteria(NFB)can fix N_(2)to form ammonia and thus provide bioavailable nitrogen.However,there is limited knowledge about the distribution of NFB and its influencing factors in Tibetan hot springs.Here,we measured hydrochemical variables of the hot springs with a wide temperature range(32–77°C)in the Qucai and Daggyai geothermal zones on the Tibetan Plateau and investigated the composition of NFB using high-throughput sequencing of 16SrRNA and nif H genes.The Cl^(-)/SO_(4)^(2-)ratio in Qucai hot springs was higher than that in Daggyai,indicating that Qucai and Daggyai hot springs were more affected by the supply of liquid and gaseous phases,respectively.The NFB communities consisted predominantly of Nirtospirae,Chloroflexi,Deltaproteobacteria and an unidentified clade,with the last three acting as the main NFB with over 42%of the communities(the proportions are significantly larger than those found in hot springs of other geothermal regions).This demonstrates the uniqueness of NFB communities in Tibetan hot springs.NFB richness was limited by temperature in the studied Tibetan hot springs and was significantly lower than in low-elevation geothermal regions.The NFB community was predominantly affected by hydrochemistry,in contrast to the entire prokaryotic community,which was primarily influenced by temperature.This study expands our current understanding of NFB distribution and diversity as well as biogeochemical process in geothermal spring environments.
文摘Based on tourist resources' evaluation and tourism market development of Huangshan Hot Spring Scenic Area,by combining with relevant theories of "SWOT",the paper has identif ied the leading functional orientation and tourism development idea of the hot spring scenic area.Meanwhile,by following the principle of "sustainable use" of Huangshan natural resources,planning strategies and implementing suggestions have been put forward based on "addition,subtraction,multiplication and division".The ultimate purpose is to create diversified tourism experiences for tourists and improve tour quality of hot spring scenic area,and f inally build Huangshan tourism brand of "Snowy Hot Spring".
文摘The basic situation and formation mechanism of hot spring in Liaocheng were introduced,and its utilization value as well as exploitation and utilization status were also analyzed in this study,which provided strategies for exploitation and utilization of hot spring in Liaocheng.
文摘Tourist's satisfaction degree is one of the important indexes to evaluate the service quality of scenic spot.Taking Xi'an Dongda Hot Spring Resort Area for an example,with the expectation difference theory and customers' satisfaction evaluation model as the theoretical basis of the research,the overall satisfaction degree of tourists to hot spring resort area,and the actual sensation accomplishments and the expectation difference of each service index were analyzed by using regression analysis and paired sample t test method.The results showed:① The overall satisfaction degree of tourists to the resort area was higher.There were remarkable correlation among three variables:the sensation value,the overall satisfaction degree,and the tourist's loyalty degree;② Generally,the sensation actual accomplishments of 15 service appraisal factors were higher than the expectation value.According to the characteristics,these 15 service appraisal factors were divided into 5 groups.Some unsatisfactory aspects were found out,and the corrective measures were put forward.
基金Supported by Natural Science Foundation of China (40961008)~~
文摘The paper had introduced geographic causes and types of hot springs, illustrated its disease-treating function and displayed its great vitality and widespread development prospect as tourist resources. By taking Shawan Hot Spring in Xinjiang for example, the paper had analyzed its natural condition, hot springs and tourist economic development. And then, quantitative and qualitative analysis had been conducted on the quality of water environment resources in the research area. It had analyzed reasons for degeneration of water environment and studied exploitation and sustainable development of hot springs. It was considered that environment especially water environment quality had decreased since hot spring tourism development. In order to achieve sustainable development of hot springs and promotion of local tourism, it must be guided by environment treatment, and some strategies for sustainable development of hot springs had been proposed.
文摘Taking Xingzi hot spring in Jiangxi for an example and tourist behaviors of hot-spring tourism as the research object,tourist behaviors and psychological feelings were analyzed in this study to discuss the sustainable Development Countermeasures of hot-spring tourism.
基金supported by the Major State Basic Research Development Program of the People's Republic of China(973 project)(No.2009CB421008)the 111 Project(No.B07011)+2 种基金the National Natural Science Foundation of China(No.40234051)the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT0755)the Special Plans of Science and Technology of Land Resource Department(No. 20010103)
文摘The Tengchong geothermal area,an active tectonic region with frequent earthquakes,is located in Yunnan Province of southwestern China.This area contains abundant active hot springs, which often display high metal concentrations and obvious mineralization phenomena.At 19：19 on 9 July 2009,an earthquake occurred in Yao＇an,Chuxiong,Yunnan Province,which is 300 km to the northeast of the Tengchong geothermal area.We sampled water in the hot springs in the Tengchong area from 4 July to 9 July 2009 and from 10 July to 15 July 2009 to study the changes of elemental concentrations before and after the earthquake and discuss the influence of the earthquake on the mineralization of the hot springs.The concentrations of most trace elements increased slightly,but the concentration of REE（rare earth elements） decreased by 50%after the earthquake in the hot springs around a NS-trending fault.The elemental concentrations remained unchanged in Longtan and Suanshuigou,which are related to an inactive crater.The elemental concentrations in other springs controlled by superficial and small-scale faults decreased after the earthquake.The earthquake can stimulate the activity of deep faults and magma chambers,as is responsible for the increase of metal concentrations in the hot springs along the NS-trending deep fault;whereas it can decrease the porosity of permeable rocks,resulting in the decline of the flux of ore-bearing fluids and the corresponding mineralization in the hot springs related to superficial faults.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB06060200)the National Natural Science Foundation of China (grants 41403050)
文摘A slightly acidic hot spring named ＂Female Tower＂（t=73.5°C, pH=6.64） is located in the Jifei Geothermal Field, Yunnan Province, southwestern China. The precipitates in the hot spring are composed of large amounts of calcite, aragonite and sulfur. Scanning electron microscopy（SEM） analyses reveal that the microbial mats were formed from various coccoid or rod-shaped filamentous microbes. Transmission electron microscopy（TEM） shows that the intracellular sulfur granules are commonly associated with these microbes. A culture-independent molecular phylogenetic analysis demonstrates that the majority of the bacteria in the spring are sulfur-oxidizing bacteria. In the spring water, H2S concentration is up to 60 ppm, while SO4-（2-） concentration is only about 10 ppm. We speculate that H2S might derive from sulfur-oxidizing bacteria in this hot spring water, leading to the intracellular formation of sulfur granules. Meanwhile, this reaction increased the p H in the micronscale microdomains, which fosters the precipitation of calcium carbonate in the microbial mats. The results of this study indicate that the sulfur-oxidizing bacteria might play an important role in calcium carbonate precipitation in slightly acidic hot spring environments.
基金co-supported by the National Key Project on Basic Research(2011CB403006)the Special Fund for Scientific Research of Central-leveled Academy(K2007-3-2)National Geological Survey(1212010818057,1212011120046)
文摘Microbial mats, mainly dominated by filamentous algae Calothrix and Oscillatoria, are well developed in Tibetan hot springs. A great number of fossil microorganisms, which existed as algae lamination in thermal depositional cesium-bearing geyserite in this area, are identified as Calothrix and Oscillatoria through microexamination and culture experiments. These microbial mats show the ability to accumulate cesium from spring water to the extent of cesium concentration of 0.46-1.03% cell dry weight, 900 times higher than that in water, and capture large numbers of cesium-bearing opal grain. Silicon dioxide colloid in spring water replaces and fills with the organism and deposits on it to form algae laminated geyserite after dehydration and congelation. Cesium in the microbial mats and opal grain is then reserved in the geyserite. Eventually, cesium-bearing algae laminated geyserite is formed. Study on cesium distribution in geyserite also shows that cesium content in algae lamination, especially in heavily compacted algae lamination, is higher than in the opal layer. For geyserite with no algae lamination or other organism structure, which is generally formed in spring water with low silicon content, cesium accumulation and cesium-bearing opal grain assembled by the microbial mats are also indispensable. After the microbial mats accumulating cesium from spring water, silicon dioxide colloid poorly replaces and fills with the organism to form opal grain-bearing tremellose microbial mats. The shape and structure of the organisms are then destroyed, resulting in cesium-bearing geyserite with no algae lamination structure after dehydration and congelation. It is then concluded that microbial mats in the spring area contribute to the enrichment of cesium in the formation of cesium-bearing geyserite, and a biological genesis of the geyserite, besides of the physical and chemical genesis, is likely.
基金supported by the National Natural Science Foundation of China(Grant No.40972211)the US National Science Foundation(Grant Nos.ETBC-1024614 and OISE- 0968421 )
文摘Isoprenoidal glycerol dialkyl glycerol tetraethers （iGDGTs） from the Gulu hot springs （23--83.6 ℃, pH 〉 7） and Yangbajing hot springs （80-128 ℃, pH 〉 7） were analyzed in order to investigate the distribution of archaeal lipids among different hot springs in Tibet. A soil sample from Gulu was incubated at different temperatures and analyzed for changes in iGDGTs to help evaluate whether surrounding soil may contribute to the iGDGTs in hot springs. The sources of bacterial GDGTs （bGDGTs） in these hot springs were also investigated. The results revealed different profiles ofiGDGTs between Gulu and Yangbajing hot springs. Core iGDGTs and polar iGDGTs also presented different patterns in each hot spring. The PCA analysis showed that the structure of polar iGDGTs can be explained by three factors and suggested multiple sources of these compounds. Bivariate correlation analysis showed significant positive correlations between polar and core bGDGTs, suggesting the in situ production of bGDGTs in the hot springs. Furthermore, in the soil incubation experiment, temperature had the most significant influence on concentration of bGDGTs rather than iGDGTs, and polar bGDGTs had greater variability than core bGDGTs with changing temperature. Our results indicated that soil input had little influence on the composition of GDGTs in Tibetan hot springs.
基金financially supported jointly by the National Natural Science foundation of China (Grant Nos.40602031,41440027)the China Geological Survey project (Grant No.1212011220014)
文摘Hot springs are natural exposed points of the hydrothermal system. The hydrogeochemistry of hot springs can be used to interpret the formation of the hydrothermal system; and the ^(14)C dating can be used to evaluate the renewability of the hydrothermal system. The hot springs exposed from fault zones in western Guangdong are classified as granite fissure water and clastic rock fissure water, which are sampled and tested. The results of water chemistry analysis show that hot spring water is mainly HCO_3-Na type in the beginning, while the mixing of seawater leads to the increase of Cl^-. Hydrogen and oxygen isotopes indicate that these hot springs mainly come from atmospheric precipitation, and water-rock interactions produce oxygen isotope exchange reactions, where a significant "oxygen drift" phenomenon can be observed. The relationship between δ^(13)C and HCO_3^- indicates that there is a deep source of CO_2 "dead carbon" in hot spring water. This systematic error is not considered in the existing ^(14)C dating correction models. The ^(14)C age of the deep source "dead carbon" correction proposed in this paper is close to the ^(14)C age of the reverse chemical simulation correction, the Gonfiantinie model, and the Mook model. The deep source "dead carbon" correction method can improve the systematic error. Therefore, the ^(14)C age corrected by the deep source "dead carbon" may be more representative in terms of the actual age of geothermal water.
基金supported by the Basic Scientific Research Foundation of FIO, SOA (2010G13)the National Natural Science Foundation of China (41076108)+1 种基金the Science Foundation for Youth Scholars of State Oceanic Administration (2012131)the Public Welfare Project of Marine Science Research (200805039)
文摘A total of 69 strains of thermophilic bacteria were isolated from water, soil and sediment samples from three Indonesia's hot spring areas (Pantai cermin, Kalianda and Banyu wedang) by using Minimal Synthetic Medium (MSM). The extreme thermophile Brevibacillus sp. PLI-1 was found to produce extracellular thermophilic alkaline protease with optimal activity at 70℃ and pH 8.0-9.0. The molecular weight of the protease was estimated to be around 56 kD by SDS-PAGE. The maximum activity of the protease was 26.54 U mL-1. The protease activity did not decrease after 30 min and still retained more than 70% of relative activity after 60 min at 70℃ and pH 8.0. The ion Mg2+ was found to promote protease activity at both low and high concentrations, whereas Cu2+ and Zn2+ could almost completely inhibit the activity. Divalent cation chelator EDTA inhibited the enzyme activity by 55.06% ± 0.27%, while the inhibition caused by PMSF, Leupeptin, Pepstain A and Benzamidine were 66.78% ± 3.25%, 52.37% ± 0.25%, 62.47% ± 2.96% and 50.99% ± 0.24%, respectively. Based on these observations, the enzyme activity was conspicuously sensitive to the serine and cysteine protease inhibitors. All these results indicated that the protease isolated from the strain PLI-1 was a thermophilic protease and had a high-temperature stability and a pH stability.
基金Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(P0012724,The Competency Development Program for Industry Specialist)and the Soonchunhyang University Research Fund.
文摘Electrocardiogram(ECG)electrodes are conductive pads applied to the skin to measure cardiac activity.Ag/AgCl electrodes are the commercial product which widely used to obtain ECGs.When monitoring the ECG in a hot spring,Ag/AgCl electrodes must be waterproofed;however,this is time-consuming,and the adhesive may tear the skin on removal.For solving the problem,we developed the carbon pencil lead(CPL)electrodes for use in hot springs.Both CPL and Ag/AgCl electrodes were connected to ECG100C’s cables.The Performance was evaluated in three conditions as following:hot spring water with and without bubble,and in cold water.In each environment,the procedure was followed by three different protocols that are recording from the dry condition,hot spring water immersion with and without movement,post hot spring water condition.Under dry and wet conditions,both electrodes can obtain the waveform of the ECG signal in which all PQRST waves were identifiable.Nevertheless,the signal quality of both types of electrodes was different in water immersion with and without movement.The overall morphology obtained by Ag/AgCl electrodes was unstable higher than that of CPL electrodes in immersion without movement condition.The CPL electrodes provided better ECG waveform quality compared to Ag/AgCl electrodes in which the ECG signal had high waveforms distortion in water immersion with movement condition.
文摘Heredity in the microstructure and mechanical properties of hot-rolled spring steel wire 60Si2MnA during heat treatment process was investigated comprehensively. The steel was isothermally transformed to obtain various hot-rolled microstructure （pearlite fineness within the range of 140-510 nm） and mechanical properties, and followed by some quenching-tempering treatment. Afterwards, microstructure was characterized by optical microscopy, scanning electron microscopy and quantitative metallography, and mechanical properties were determined by tensile test. The results indicated that the hot-rolled microstructure with a coarsen pearlite structure had been changed after reheating, to a austenite microstructure with bigger and more uneven grain size, and finally to a coarsen tempered microstructure. And the average austenite grain size and standard deviation of its distribution in quenched microstructure were observed to depend linearly on the interlamellar spacing in hot-rolled microstructure. Besides, to obtain a good combination of the final strength and plasticity, an optimum value range （190-280 nm） of the interlamellar spacing had been determined for the interlamellar spacing in hot-rolled microstructure.
基金the stuff of National Research of Astronomy and Geophysics,Egypt for their continuous support and help
文摘The Gulf of Suez region is one of the most interesting geothermal areas in Egypt because of the high temperatures of its springs.The eastern and western shores of the Gulf of Suez are characterized by superficial thermal manifestations including a cluster of hot springs with varied temperatures.Variations of deuterium and oxygen-18 concentrations in thermal waters have been used to aid in describing the source of recharge in the Gulf of Suez hot springs.Isotope and geochemical data for the Gulf of Suez thermal waters suggest that recharge to the hot springs may not be entirely from the Gulf of Suez water,but possibly from the meteoric water that comes from areas of higher altitude surrounding the hot springs.
基金jointly by the National Natural Science Foundation of China(Grant Nos.40173006 and 49133009)the Key Project of the Ministry of Education(No.03106)
文摘Gas concentrations and isotopic compositions of He and CO2 were determined on free gas samples from ten hot springs of the Rehai geothermal field, Tengchong, China. The results showed that hot-spring CO2 gas, together with He, was derived mainly from the mantle, indicating the accumulation of mantle-derived volatiles beneath the survey area. The δ 13C values of CO2, higher than those of the typical mantle-derived carbon and the isotopic composition of hot-spring-free CO2 in unequilibrium with dissolved CO2, are recognized only in the Rehai geothermal field, suggesting that there seems to be a still-degassing magmatic intrusion at depths, which provides mantle-derived volatiles to the hydrothermal system above. The accumulation of those volatiles has probably played an important role in triggering earthquakes in this region. In addition, the isotopic characteristics of He and C also indicate that the magmatic intrusion seems to have been derived from the MORB source, and could be contaminated by crustal materials during its upwelling through the continental crust.
基金financially supported jointly by the National Natural Science Foundation of China (Grant No.40601004)the Scientific and Technological Project of the Educa-tion Department of Jiangxi Province (No. GJJ08032)+1 种基金the K.C. Wong Education FoundationHong Kong and China’s Post-doctoral Science Funds
文摘Drinking water-type fluorosis is the most harmful endemic disease in China with the largest number of sufferers. Although the implementation of the policy to alter water sources to lower fluoride level has effectively controlled the spread of this kind of endemic disease,its prevalence could not thoroughly be stopped because the high-fluoride environmental background in these endemically diseased areas could still do harm to human health through food chain. Therefore,it is necessary to conduct a more deep-going study on the drinking water-type fluoro-sis. To investigate the effect of high fluorine environmental background on crops and human health in the hot spring-type fluorosis-diseased areas,local water,paddy soil,rice,whole vegetables and soils around their roots were sampled for analysis. The results were compared with those of the control groups in fluorosis-free areas which are similar to the fluorosis-diseased areas both in natural background and in social background. It is indicated that rice and vegetables can accumulate water-soluble fluorine either in soils or in irrigating water,and different crops have different abilities of fixing fluorine. The contents of fluorine in different parts of vegetables in the fluorosis-diseased and fluorosis-free areas were statistically categorized. The results showed that the fluorine contents of roots,tubers,leaves and flowers of vegetables in the fluorosis-diseased areas are 3.56,1.17,3.07 and 3.23 mg/kg,respectively. However,comparisons showed that in the fluorosis-free areas,the fluorine contents are 2.17,0.70,1.91 and 2.52 mg/kg,respectively. Moreover,different parts of a crop also show significantly different fluorine fixation abilities. It is demonstrated that the fluorine contents of the strongly metabolic parts are relatively high. For example,the fluo-rine contents of roots,leaves and flowers of vegetables are much higher than those of stems. The fluorine fixation ability of seeds is very weak. In order to reduce the risk of human body’s exposure to fluoride,the impact of hot spring water on the capability of crops to fix fluorine should be reduced as much as possible. It is of great importance to prevent crops from being irrigated with hot spring water and it is advisable to grow crops with relatively low ca-pabilities to enrich fluorine,such as those with seeds or tubers as the main edible parts in the areas which are se-verely affected by hot spring water.
基金funded by FONDECYT Regular,Grant Number 1231917 by ANID,Govt.of Chile.
文摘A type of high molecular weight bioactive polymers called exopolysaccharides(EPS)are produced by thermophiles,the extremophilic microbes that thrive in acidic environmental conditions of hot springs with excessively warm temperatures.Over time,EPS became important as natural biotechnological additives because of their noncytotoxic,emulsifying,antioxidant,or immunostimulant activities.In this article,we unravelled a new EPS produced by Staphy-lococcus sp.BSP3 from an acidic(pH 6.03)San Pedro hot spring(38.1℃)located in the central Andean mountains in Chile.Several physicochemical techniques were performed to characterize the EPS structure including Scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDS),Atomic Force Microscopy(AFM),High-Performance Liquid Chromatography(HPLC),Gel permeation chromatography(GPC),Fourier Transform Infrared Spectroscopy(FTIR),1D Nuclear Magnetic Resonance(NMR),and Thermogravimetric analysis(TGA).It was confirmed that the amorphous surface of the BSP3 EPS,composed of rough pillar-like nanostructures,is evenly distributed.The main EPS monosaccharide constituents were mannose(72%),glucose(24%)and galactose(4%).Also,it is a medium molecular weight(43.7 kDa)heteropolysaccharide.NMR spectroscopy demonstrated the presence of a[→6)-α-d-Manp-(1→6)-α-d-Manp-(1→]backbone 2-O substituted with 1-α-d-Manp.A high thermal stability of EPS(287°C)was confirmed by TGA analysis.Emulsification,antioxidant,flocculation,water-holding(WHC),and oil-holding(OHC)capacities are also studied for biotechnological industry applications.The results demonstrated that BSP3 EPS could be used as a biodegradable material for different purposes,like flocculation and natural additives in product formulation.
文摘Background: Use of novel microorganisms for beneficial purposes is still remaining a challenging job. This study was designed to isolate, characterize and use of a novel hot spring bacterial strain from a virgin hot spring of Metaldanga, Birbhum, West Bengal, India. Methods: A pure bacterial strain (MDH1) was identified by growing the enrichment culture isolated from Metaldanga hot spring through serial dilution process in a semi-synthetic medium at pH 8.0 and 42°C temperature. The novelty of the strain was characterized by 16S-rRNA gene sequence analysis. The bacterium acted as template to synthesize spherical gold nanoparticles (GNPs). GNPs were characterized by using UV-Vis spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS) and Fourier transform infra-red spectroscopy (FTIR). Results: The phylogenetic analysis suggested that MDH1 strain (GenBank accession number: KT600031) was affiliated to the family “Pseudomonadaceae” with 99% homologous to Pseudomonas putida H8234. The coccoid shaped bacterium was gram-negative and facultative-anaerobic which acted as a template to synthesize spherical GNPs with an average size of 12 ± 3 nm when examined under transmission electron microscopy (TEM). FT-IR studies revealed the presence of bioactive functional groups which acted as capping and stabilizing agents of the GNPs. XRD pattern confirmed the amorphous nature of GNPs. The Zeta potential (ζ) concluded the adequate stability of GNPs in an aqueous environment. Conclusions: The present investigation explores the microbial diversity of a virgin hot spring of Metaldanga for its beneficial applications in industry, particularly in the synthesis of the gold nanoparticles.
文摘Chongqing Beiwenquan hot springs were continuously monitored from May 1 to July 4,2008,during the May 12,2008 Ms 8.0 earthquake.On the spot in these hot springs were measured during this time. Chongqing Beiwenquan hot spring about 400 km away from Wenchuan Sichuan,had a huge response to the earthquake.After the earthquake,three higher elevation springs are cutoff,and the other four springs’ discharge has been increased nearly 50%. Temperature of these springs all reduced 1℃. Concentration of K<sup>+</sup>,Na<sup>+</sup>,Ca<sup>2+</sup> in these hot springs has been reduced,and has an excellent linear correlation.Concentration of Mg<sup>2+</sup> has been increased,Concentration of SO<sub>4</sub><sup>2-</sup>,F<sup>-</sup> has
