Using research approaches such as questionnaire investigation, interview, and Participatory Rural Appraisal (PAR), the relationship between Haba Snow Mountain Nature Reserve and peripheral communities was studied. The...Using research approaches such as questionnaire investigation, interview, and Participatory Rural Appraisal (PAR), the relationship between Haba Snow Mountain Nature Reserve and peripheral communities was studied. The results showed that there are lots of conflicts between Haba Snow Mountain Nature Reserve and peripheral communities. On the one hand, conservation of natural environment brings inconvenience to the development of peripheral communities, such as limiting the use of resources, constraining space of development, resulting in economic losses, reducing tourist income, and low compensation. On the other hand, peripheral communities' development threats conservation of the natural environment, for instance, illegal deforestation, illegal mining, over-harvesting, over-grazing and non-ecotourism. Therefore, effective suggestions were given as "scientific planning of functional areas, enhancing economic compensation, devoting more in ecotourism development, and realizing the cooperation of communities".展开更多
With Maolan National Natural Reserve as the example,the present development of ecotourism and its great significance to community economic development were expounded,the main problems existing in the ecotourist develo...With Maolan National Natural Reserve as the example,the present development of ecotourism and its great significance to community economic development were expounded,the main problems existing in the ecotourist development of Maolan Reserve were exposed,and some suggestions were proposed for speeding up the construction pace of ecotourism,improving the service level and reception capacity,expanding the coverage of people receiving benefits from tourist economy,strengthening the development of tourist products,elongating the industrial chain of tourist economy and establishing feedback mechanism so as to promote the community economic development.展开更多
Deyeuxia angustifolia wetlands were widely distributed in the Sanjiang Plain in Northeast China. Due to strong demand for food production, large-area wetlands were reclaimed to farmlands, which threatened regional eco...Deyeuxia angustifolia wetlands were widely distributed in the Sanjiang Plain in Northeast China. Due to strong demand for food production, large-area wetlands were reclaimed to farmlands, which threatened regional ecological security greatly. Since the 21 th century, returning farmlands to wetlands was widely adopted for natural restoration in the Sangjiang Plain. As the first reflection of wetland restoration, vegetation succession of restored D. angustifolia wetlands should be fully assessed. In this study, vegetation investigation was carried out in three restored D. angustifolia wetlands with 5, 8 and 12 yr restoration, respectively. Meanwhile, a natural D. angustifolia wetland was selected as reference wetland. Results showed that community composition changed greatly and there was visible community succession. Community dominant species changed from composite to gramineae as restoration time increasing.At first, weeds community appeared in the restored wetlands, especially the xerophytes developed to the pioneer species rapidly. And then, mesophytes and wetland species became the dominant species in the restored wetlands. Finally, wetland species, especially D. angustifolia, occupied the dominant position of restored community. Shannon-wiener index(H) and Simpson index(D) both decreased to close to natural D. angustifolia wetlands. Compared with natural D. angustifolia wetland, species composition and diversity in restored wetlands were more complex and higher. As restoration time increasing, there were not significant differences between community characteristics of restored wetlands and natural wetland. All these suggested that vegetation in reclaimed D. angustifolia wetland could be restored naturally, but its restored period is 10 yr at least. From another angle, it is important to protect current natural wetlands.展开更多
The forms of phosphorus and silicon in the natural grain sizes surface sediments of the southern Bohai Sea were studied. In sediments, the organic matter bound form of phosphorus was the main form of transferable phos...The forms of phosphorus and silicon in the natural grain sizes surface sediments of the southern Bohai Sea were studied. In sediments, the organic matter bound form of phosphorus was the main form of transferable phosphorus and ranged from 0.37 μmol/g to 1.57 μmol/g, accounting for 10.7% of the total phosphorus, others were the carbonate bound form, iron manganese oxide bound form and ion exchange able form; the transferable form of phosphorus accounted for 19.2% of the total phosphorus. Silicon’s carbonate bound form was predominant over others among its transferable forms, and content ranged from 1.55 μmol/g to 8.94 μmol/g, accounting for 0.05% of the total silicon; the total amount of transferable silicon forms accounted for only 0.12% of the total silicon. Therefore, 19.2% of the total phosphorus and 0.12% of the total silicon contained in the surface sediments of the southern Bohai Sea could participate in the biogeochemical cycling.展开更多
This paper introduces a new concept of community-based ecotourism (CBET) that originated in foreign countries. Then it analyzes the significance of CBET development in nature reserve (NR). The authors think that commu...This paper introduces a new concept of community-based ecotourism (CBET) that originated in foreign countries. Then it analyzes the significance of CBET development in nature reserve (NR). The authors think that community participation is the evitable choice of nature reserve′s conservation and development. CBET, as the self-improved model of ecotourism, can promote tourism community sustainable development. Based on the stakeholder analysis of CBET in NRs, this paper addresses the reality, especially the problem of CBET development in NRs of China. In order to develop CBET in NRs of China, this paper takes some suggestions to promote the community participation: 1)gradual political empowerment, 2) deep level economic incentive, 3) widespread educational support, 4) impartial distribution of community benefits, and 5) stakeholders cooperation.展开更多
To identify impact factors on the distribution and characters of natural plants community in reclamation area, with survey data from 67 plant quadrats in July 2009, soil properties data from 216 sampling points in Apr...To identify impact factors on the distribution and characters of natural plants community in reclamation area, with survey data from 67 plant quadrats in July 2009, soil properties data from 216 sampling points in April 2009, and TM (30 m) data in 2006, the composition and characteristics of natural plants community in different time of the Fengxian area in the Changjiang (Yangtze) River estuary were analyzed with two-way indicator species analysis (TWINSPAN), multivariate analysis of variance (MANOVA), detrended canonical correspondence analysis (DCCA) and canonical correspondence analysis (CCA). The results show that: 1) The plant communities in the reclaimed area are mainly mesophytes and helophytic-mesophytic transitional communities, showing a gradient distribution trend with the change in reclamation years. Species richness (MA), species diversity (H) and above-ground biomass also increase with the increase of reclamation years. Nevertheless, they appear to decline slightly in the middle and late reclamation period (> 30 years). 2) With the rise in land use levels, the changes in species richness and species diversity tend to increase at first and then decrease; species dominance (D), however, tends to decline; and above-ground biomass increases slightly. 3) The distribution of the plant community is mainly influenced by the following factors: land use levels (R = 0.55, p < 0.05), soil moisture (R = 0.53, p < 0.05), soil salinity (R = 0.43, p < 0.05) and reclamation time (R = 0.40, p < 0.05).展开更多
Bird communities were surveyed in natural deciduous forest of both slope area and valley area at Mt. Gyebangsan (3740 30 N, 12830 1 E), Gangwon Province, South Korea in winter, spring, summer and autumn from September...Bird communities were surveyed in natural deciduous forest of both slope area and valley area at Mt. Gyebangsan (3740 30 N, 12830 1 E), Gangwon Province, South Korea in winter, spring, summer and autumn from September 2000 to November 2001. The investigating results showed that there existed differences in the bird species composition, richness, bird species diversity, guild structure between slope area and valley area, and the vertical forest structure, especially coverage of understory, and diameter at breast height (DBH) distribution also had significant difference between the two study areas. The differences in habitat structure between the areas are very likely to have influences on how birds used the available habitat.展开更多
Species diversity and stability of natural secondary communities in different layers with different cutting intensities 10 years later were investigated by calculating Marglef Richness index(R),Shannon-Wiener divers...Species diversity and stability of natural secondary communities in different layers with different cutting intensities 10 years later were investigated by calculating Marglef Richness index(R),Shannon-Wiener diversity index(H),Simpson diversity index(P),and Pielou Evenness index(J).Results show that the values of R,H and P among different layers are listed in a decreasing order:the shrub layer the arbor layer the herb layer,all the three indices values reach the maximum under medium selective cutting intensity after 10 years.The J value of the shrub layer shows a concave parabolic change with the increase in cutting intensity;it shows a linear increase for the arbor layer,whereas the J value of the herb layer shows an opposite change pattern.The values of R at different cutting intensities had high significant difference,but other indices had not significant difference.The stability of communities at different cutting intensities after 10 years is non-cutting low selective cutting intensity medium selective cutting intensity high selective cutting intensity extra-high intensity clear cutting.The stability of communities at different cutting intensities after 10 years shows that the greater cutting intensities,the worse the stability is.展开更多
The Crested Ibis(Nipponia Nippon) is endemic to Qinling Mountains of China and was once abundant over vast areas of north-east of Asia habitat.During the 20th century,however,the population declined greatly in numbers...The Crested Ibis(Nipponia Nippon) is endemic to Qinling Mountains of China and was once abundant over vast areas of north-east of Asia habitat.During the 20th century,however,the population declined greatly in numbers.Habitat quality used to be the main threat to this species but recent actions by the government and wildlife protection organizations have brought this under control.With the establishment of Crested Ibis Nature Reserve in China,conflicts between socio-economic development and Crested Ibis conservation have become more acute.How do we deal with the relation between Crested Ibis conservation and community development? In this study,the Crested Ibis Nature Reserve co-management model namely "companies + farmers + Nature Reserve" model is proposed and evaluated with demonstration investigation methods,including continuous six-year fixed-site socio-economic development data of surrounding community,company sales revenue data and monitored data of Crested Ibis Nature Reserve.The results show that farmers' income and conservation awareness increased greatly from 2003 to 2008;company sales revenue has increased by about 20% annually in the recent years;management level has noticeably improved in Nature Reserve,the scope of Crested Ibis habitat has expanded 50 hm2;chemical composition of habitat reduced year after year;and the number of Crested Ibis had been growing annually.At the end,the success of the model is evaluated,and problems in implementation of the model are discussed from the following aspects:management system,co-management concept,economic base of partners,marketing mechanism,technical capacity and so on.展开更多
As a typical inland wetland, Yangguan nature reserve wetland in Dunhuang is one of the important stops of migratory route for birds, which is vulnerable and particular. Study on the community characteristics and speci...As a typical inland wetland, Yangguan nature reserve wetland in Dunhuang is one of the important stops of migratory route for birds, which is vulnerable and particular. Study on the community characteristics and species diversity of wetland has great signifi cance for biodiversity protection. Based on the fi eld investigation, the fl oristic composition, geographical elements and species diversity of wetland plants were studied in Yangguan reserve of Dunhuang. The results showed that 26 families, 56 genera and 74 species were recorded in the study area. The largest families were the Gramineae and Chenopodiaceae, accounting for 29.73% of the total. Herbs were the most abundant life-form, accounting for 77.03% of the total. The fl oral geographical elements of the plants were mainly composed of temperate zone distribution type. By using two way indicator species analysis(TWINSPAN), the vegetation in 36 sampling plots could be classifi ed into 8 communities. The species diversity indexes of communities were relatively low, but had large differences among each other. According to the importance value, the Margalef richness index(Rm) ranged from 0 to 4.200. Simpson diversity index(D) was between 0 and 0.512; Shannon diversity index(H) ranged from 0 to 1.400, and Pielou evenness index(J) was within the range of 0.538 to 1.000. The results indicated that the plant species were relatively rare and simple in general, the species diversity of communities was low, and the ecological environment was fragile in Yangguan nature reserve of Dunhuang.展开更多
Coal-formed gas generated from the Permo-Carboniferous coal measures has become one of the most important targets for deep hydrocarbon exploration in the Bohai Bay Basin,offshore eastern China.However,the proven gas r...Coal-formed gas generated from the Permo-Carboniferous coal measures has become one of the most important targets for deep hydrocarbon exploration in the Bohai Bay Basin,offshore eastern China.However,the proven gas reserves from this source rock remain low to date,and the distribution characteristics and accumulation model for the coal-formed gas are not clear.Here we review the coal-formed gas deposits formed from the Permo-Carboniferous coal measures in the Bohai Bay Basin.The accumulations are scattered,and dominated by middle-small sized gas fields,of which the proven reserves ranging from 0.002 to 149.4×108 m3 with an average of 44.30×108 m3 and a mid-point of 8.16×108 m3.The commercially valuable gas fields are mainly found in the central and southern parts of the basin.Vertically,the coal-formed gas is accumulated at multiple stratigraphic levels from Paleogene to Archaeozoic,among which the Paleogene and PermoCarboniferous are the main reservoir strata.According to the transporting pathway,filling mechanism and the relationship between source rocks and reservoir,the coal-formed gas accumulation model can be defined into three types:"Upward migrated,fault transported gas"accumulation model,"Laterally migrated,sandbody transported gas"accumulation model,and"Downward migrated,sub-source,fracture transported gas"accumulation model.Source rock distribution,thermal evolution and hydrocarbon generation capacity are the fundamental controlling factors for the macro distribution and enrichment of the coal-formed gas.The fault activity and the configuration of fault and caprock control the vertical enrichment pattern.展开更多
We investigated preparation of film dosage form (FD) from natural polysaccharides using the casting method without organic solvents, heating or pH control. Ferulic acid (FA) and catechin were employed as model compoun...We investigated preparation of film dosage form (FD) from natural polysaccharides using the casting method without organic solvents, heating or pH control. Ferulic acid (FA) and catechin were employed as model compounds incorporated in the FD, and the release profile of each compound from the form was investigated in the limited medium. Film formation was affected by the addition of the model compound to the polysaccharide solution. Rigid FD was obtained with 2% low-molecular-weight alginate (L-ALG;thickness, 65 μm), and it hardened after the addition of 0.5% polygalacturonic acid, although the thickness of the film did not change. The FDs immediately released the model compound, and the forms dissolved in phosphate-buffered saline. FD modification did not affect the FA release rate except in the early stage. FD would be a useful dosage form, especially for preventing or treating localized problems in the oral cavity.展开更多
Because Elsevier takes care of JNGC's international institutional print subscriptions beginning from 2006,please visit the following website of Elsevier for the international Institutional orders.
Because Elsevier takes care of JNGC’s international institutional print subscriptions beginning from 2006,please visit the following website of Elsevier for the international Institutional orders.http://www.elsevier....Because Elsevier takes care of JNGC’s international institutional print subscriptions beginning from 2006,please visit the following website of Elsevier for the international Institutional orders.http://www.elsevier.com/locate/jngc展开更多
基金Supported by the Program of China Huaneng Group: Comprehensive Scientific Research on the Haba Snow Mountain in Yunnan Province~~
文摘Using research approaches such as questionnaire investigation, interview, and Participatory Rural Appraisal (PAR), the relationship between Haba Snow Mountain Nature Reserve and peripheral communities was studied. The results showed that there are lots of conflicts between Haba Snow Mountain Nature Reserve and peripheral communities. On the one hand, conservation of natural environment brings inconvenience to the development of peripheral communities, such as limiting the use of resources, constraining space of development, resulting in economic losses, reducing tourist income, and low compensation. On the other hand, peripheral communities' development threats conservation of the natural environment, for instance, illegal deforestation, illegal mining, over-harvesting, over-grazing and non-ecotourism. Therefore, effective suggestions were given as "scientific planning of functional areas, enhancing economic compensation, devoting more in ecotourism development, and realizing the cooperation of communities".
基金Supported by Soft Science Programs of Guizhou Province (2009) 2011~~
文摘With Maolan National Natural Reserve as the example,the present development of ecotourism and its great significance to community economic development were expounded,the main problems existing in the ecotourist development of Maolan Reserve were exposed,and some suggestions were proposed for speeding up the construction pace of ecotourism,improving the service level and reception capacity,expanding the coverage of people receiving benefits from tourist economy,strengthening the development of tourist products,elongating the industrial chain of tourist economy and establishing feedback mechanism so as to promote the community economic development.
基金Under the auspices of National Key Research and Development Program of China(No.2016YFC0500403 2017YFC0505901)National Natural Science Foundation of China(No.41871101)
文摘Deyeuxia angustifolia wetlands were widely distributed in the Sanjiang Plain in Northeast China. Due to strong demand for food production, large-area wetlands were reclaimed to farmlands, which threatened regional ecological security greatly. Since the 21 th century, returning farmlands to wetlands was widely adopted for natural restoration in the Sangjiang Plain. As the first reflection of wetland restoration, vegetation succession of restored D. angustifolia wetlands should be fully assessed. In this study, vegetation investigation was carried out in three restored D. angustifolia wetlands with 5, 8 and 12 yr restoration, respectively. Meanwhile, a natural D. angustifolia wetland was selected as reference wetland. Results showed that community composition changed greatly and there was visible community succession. Community dominant species changed from composite to gramineae as restoration time increasing.At first, weeds community appeared in the restored wetlands, especially the xerophytes developed to the pioneer species rapidly. And then, mesophytes and wetland species became the dominant species in the restored wetlands. Finally, wetland species, especially D. angustifolia, occupied the dominant position of restored community. Shannon-wiener index(H) and Simpson index(D) both decreased to close to natural D. angustifolia wetlands. Compared with natural D. angustifolia wetland, species composition and diversity in restored wetlands were more complex and higher. As restoration time increasing, there were not significant differences between community characteristics of restored wetlands and natural wetland. All these suggested that vegetation in reclaimed D. angustifolia wetland could be restored naturally, but its restored period is 10 yr at least. From another angle, it is important to protect current natural wetlands.
文摘The forms of phosphorus and silicon in the natural grain sizes surface sediments of the southern Bohai Sea were studied. In sediments, the organic matter bound form of phosphorus was the main form of transferable phosphorus and ranged from 0.37 μmol/g to 1.57 μmol/g, accounting for 10.7% of the total phosphorus, others were the carbonate bound form, iron manganese oxide bound form and ion exchange able form; the transferable form of phosphorus accounted for 19.2% of the total phosphorus. Silicon’s carbonate bound form was predominant over others among its transferable forms, and content ranged from 1.55 μmol/g to 8.94 μmol/g, accounting for 0.05% of the total silicon; the total amount of transferable silicon forms accounted for only 0.12% of the total silicon. Therefore, 19.2% of the total phosphorus and 0.12% of the total silicon contained in the surface sediments of the southern Bohai Sea could participate in the biogeochemical cycling.
基金Under the auspices of the National Natural Science Foundation of China (No. 40371039)
文摘This paper introduces a new concept of community-based ecotourism (CBET) that originated in foreign countries. Then it analyzes the significance of CBET development in nature reserve (NR). The authors think that community participation is the evitable choice of nature reserve′s conservation and development. CBET, as the self-improved model of ecotourism, can promote tourism community sustainable development. Based on the stakeholder analysis of CBET in NRs, this paper addresses the reality, especially the problem of CBET development in NRs of China. In order to develop CBET in NRs of China, this paper takes some suggestions to promote the community participation: 1)gradual political empowerment, 2) deep level economic incentive, 3) widespread educational support, 4) impartial distribution of community benefits, and 5) stakeholders cooperation.
基金Under the auspices of Ministry of Education, China (No. 108148)State Key Laboratory of Urban and Regional Ecology (No. SKLURE2010-2-2)+1 种基金National Basic Research Program of China (No. 2010CB951203)Key Research Program of Shanghai Science & Technology (No. 08231200700, 08231200702)
文摘To identify impact factors on the distribution and characters of natural plants community in reclamation area, with survey data from 67 plant quadrats in July 2009, soil properties data from 216 sampling points in April 2009, and TM (30 m) data in 2006, the composition and characteristics of natural plants community in different time of the Fengxian area in the Changjiang (Yangtze) River estuary were analyzed with two-way indicator species analysis (TWINSPAN), multivariate analysis of variance (MANOVA), detrended canonical correspondence analysis (DCCA) and canonical correspondence analysis (CCA). The results show that: 1) The plant communities in the reclaimed area are mainly mesophytes and helophytic-mesophytic transitional communities, showing a gradient distribution trend with the change in reclamation years. Species richness (MA), species diversity (H) and above-ground biomass also increase with the increase of reclamation years. Nevertheless, they appear to decline slightly in the middle and late reclamation period (> 30 years). 2) With the rise in land use levels, the changes in species richness and species diversity tend to increase at first and then decrease; species dominance (D), however, tends to decline; and above-ground biomass increases slightly. 3) The distribution of the plant community is mainly influenced by the following factors: land use levels (R = 0.55, p < 0.05), soil moisture (R = 0.53, p < 0.05), soil salinity (R = 0.43, p < 0.05) and reclamation time (R = 0.40, p < 0.05).
文摘Bird communities were surveyed in natural deciduous forest of both slope area and valley area at Mt. Gyebangsan (3740 30 N, 12830 1 E), Gangwon Province, South Korea in winter, spring, summer and autumn from September 2000 to November 2001. The investigating results showed that there existed differences in the bird species composition, richness, bird species diversity, guild structure between slope area and valley area, and the vertical forest structure, especially coverage of understory, and diameter at breast height (DBH) distribution also had significant difference between the two study areas. The differences in habitat structure between the areas are very likely to have influences on how birds used the available habitat.
基金supported by National Natural Science Foundation of China (30972359, 31070567)the Natural Science Foundation of Fujian Province (No.2006J0301, No.2008J0327,No.2009J0101)+1 种基金the Science Foundation of Science Technology of Fu-jian Province (No.2007N0002, No.2006F5006, No.2007F5010)the Science Foundation of Forestry Committee of Fujian Province (Forestry Science of Fujian[2006] No.7,No.14)
文摘Species diversity and stability of natural secondary communities in different layers with different cutting intensities 10 years later were investigated by calculating Marglef Richness index(R),Shannon-Wiener diversity index(H),Simpson diversity index(P),and Pielou Evenness index(J).Results show that the values of R,H and P among different layers are listed in a decreasing order:the shrub layer the arbor layer the herb layer,all the three indices values reach the maximum under medium selective cutting intensity after 10 years.The J value of the shrub layer shows a concave parabolic change with the increase in cutting intensity;it shows a linear increase for the arbor layer,whereas the J value of the herb layer shows an opposite change pattern.The values of R at different cutting intensities had high significant difference,but other indices had not significant difference.The stability of communities at different cutting intensities after 10 years is non-cutting low selective cutting intensity medium selective cutting intensity high selective cutting intensity extra-high intensity clear cutting.The stability of communities at different cutting intensities after 10 years shows that the greater cutting intensities,the worse the stability is.
基金supported by State Forestry Administration (China) Research and Development Plan(Grant NoSD0639)the Community Comanagement Project of WWF-China
文摘The Crested Ibis(Nipponia Nippon) is endemic to Qinling Mountains of China and was once abundant over vast areas of north-east of Asia habitat.During the 20th century,however,the population declined greatly in numbers.Habitat quality used to be the main threat to this species but recent actions by the government and wildlife protection organizations have brought this under control.With the establishment of Crested Ibis Nature Reserve in China,conflicts between socio-economic development and Crested Ibis conservation have become more acute.How do we deal with the relation between Crested Ibis conservation and community development? In this study,the Crested Ibis Nature Reserve co-management model namely "companies + farmers + Nature Reserve" model is proposed and evaluated with demonstration investigation methods,including continuous six-year fixed-site socio-economic development data of surrounding community,company sales revenue data and monitored data of Crested Ibis Nature Reserve.The results show that farmers' income and conservation awareness increased greatly from 2003 to 2008;company sales revenue has increased by about 20% annually in the recent years;management level has noticeably improved in Nature Reserve,the scope of Crested Ibis habitat has expanded 50 hm2;chemical composition of habitat reduced year after year;and the number of Crested Ibis had been growing annually.At the end,the success of the model is evaluated,and problems in implementation of the model are discussed from the following aspects:management system,co-management concept,economic base of partners,marketing mechanism,technical capacity and so on.
基金Sponsored by Global Change Special Funded Project of National Key Scientifi c Research Program(2013CB956000)
文摘As a typical inland wetland, Yangguan nature reserve wetland in Dunhuang is one of the important stops of migratory route for birds, which is vulnerable and particular. Study on the community characteristics and species diversity of wetland has great signifi cance for biodiversity protection. Based on the fi eld investigation, the fl oristic composition, geographical elements and species diversity of wetland plants were studied in Yangguan reserve of Dunhuang. The results showed that 26 families, 56 genera and 74 species were recorded in the study area. The largest families were the Gramineae and Chenopodiaceae, accounting for 29.73% of the total. Herbs were the most abundant life-form, accounting for 77.03% of the total. The fl oral geographical elements of the plants were mainly composed of temperate zone distribution type. By using two way indicator species analysis(TWINSPAN), the vegetation in 36 sampling plots could be classifi ed into 8 communities. The species diversity indexes of communities were relatively low, but had large differences among each other. According to the importance value, the Margalef richness index(Rm) ranged from 0 to 4.200. Simpson diversity index(D) was between 0 and 0.512; Shannon diversity index(H) ranged from 0 to 1.400, and Pielou evenness index(J) was within the range of 0.538 to 1.000. The results indicated that the plant species were relatively rare and simple in general, the species diversity of communities was low, and the ecological environment was fragile in Yangguan nature reserve of Dunhuang.
基金financial support from the National major projects (Item No.2016ZX05006-003)
文摘Coal-formed gas generated from the Permo-Carboniferous coal measures has become one of the most important targets for deep hydrocarbon exploration in the Bohai Bay Basin,offshore eastern China.However,the proven gas reserves from this source rock remain low to date,and the distribution characteristics and accumulation model for the coal-formed gas are not clear.Here we review the coal-formed gas deposits formed from the Permo-Carboniferous coal measures in the Bohai Bay Basin.The accumulations are scattered,and dominated by middle-small sized gas fields,of which the proven reserves ranging from 0.002 to 149.4×108 m3 with an average of 44.30×108 m3 and a mid-point of 8.16×108 m3.The commercially valuable gas fields are mainly found in the central and southern parts of the basin.Vertically,the coal-formed gas is accumulated at multiple stratigraphic levels from Paleogene to Archaeozoic,among which the Paleogene and PermoCarboniferous are the main reservoir strata.According to the transporting pathway,filling mechanism and the relationship between source rocks and reservoir,the coal-formed gas accumulation model can be defined into three types:"Upward migrated,fault transported gas"accumulation model,"Laterally migrated,sandbody transported gas"accumulation model,and"Downward migrated,sub-source,fracture transported gas"accumulation model.Source rock distribution,thermal evolution and hydrocarbon generation capacity are the fundamental controlling factors for the macro distribution and enrichment of the coal-formed gas.The fault activity and the configuration of fault and caprock control the vertical enrichment pattern.
文摘We investigated preparation of film dosage form (FD) from natural polysaccharides using the casting method without organic solvents, heating or pH control. Ferulic acid (FA) and catechin were employed as model compounds incorporated in the FD, and the release profile of each compound from the form was investigated in the limited medium. Film formation was affected by the addition of the model compound to the polysaccharide solution. Rigid FD was obtained with 2% low-molecular-weight alginate (L-ALG;thickness, 65 μm), and it hardened after the addition of 0.5% polygalacturonic acid, although the thickness of the film did not change. The FDs immediately released the model compound, and the forms dissolved in phosphate-buffered saline. FD modification did not affect the FA release rate except in the early stage. FD would be a useful dosage form, especially for preventing or treating localized problems in the oral cavity.
文摘Because Elsevier takes care of JNGC's international institutional print subscriptions beginning from 2006,please visit the following website of Elsevier for the international Institutional orders.
文摘Because Elsevier takes care of JNGC’s international institutional print subscriptions beginning from 2006,please visit the following website of Elsevier for the international Institutional orders.http://www.elsevier.com/locate/jngc