To reduce the environmental pollution and meet the needs for wearable electronic devices, new requirements for electromagnetic interference(EMI) shielding materials include flexibility, biodegradability, and biocompat...To reduce the environmental pollution and meet the needs for wearable electronic devices, new requirements for electromagnetic interference(EMI) shielding materials include flexibility, biodegradability, and biocompatibility. Herein, we reported a polypyrrole-coated zein/epoxy(PPy/ZE) ultrafine fiber mat which was inherently biodegradable and skin-friendly. In addition, it could maintain its ultrafine fibrous structure after coating, which could provide the mat with mechanical compliance, high porosity, and a large specific area for high EMI shielding. With the assistance of the epoxide cross-linking, the breaking stresses of the PPy/ZE fiber mats could achieve 3.3 MPa and 1.4 MPa and the strains were 40.1% and 83.0% in dry and wet states, respectively, which met the needs of various wearable electronic devices. Along with the extension in the PPy treatment duration, more PPy was loaded on the fiber surfaces, which formed more integrated and conductive paths to generate increasing conductivities up to 401.76 S·m^(-1). Moreover, the EMI shielding performance was raised to 26.84 dB. The biobased mats provide a green and efficient choice for EMI shielding materials, which may be a promising strategy to address EMI problems in multiple fields.展开更多
Filamentous green algae play an important functional role in element cycling and productivity in the diff erent water bodies. In hypersaline lakes and lagoons of the Crimea, filamentous green algae are present and for...Filamentous green algae play an important functional role in element cycling and productivity in the diff erent water bodies. In hypersaline lakes and lagoons of the Crimea, filamentous green algae are present and form bottom and floating mats that occupy large areas with high biomass, up to 4–5 kg(wet biomass)/m2. Cladophora spp. dominated in those mats. Five species of filamentous green algae(Chlorophyta) in Lake Chersonesskoye: C ladophora vadorum(Aresch.) Kütz., C. siwaschensis C. Meyer, C. echinus(Biasol.) Kütz., Ulothrix implexa(Kütz.) Kütz., Rhizoclonium tortuosum(Dillw.) Kütz., and seagrass(Angiospermae) R uppia cirrhosa(Petagna) Grande were found. Cladophora spp. and R. cirrhosa were found in the lake throughout the year, other types of algae were encountered episodically. In most cases the biomass of bottom mat exceeded that of the floating mat. In general, the total biomass of the bottom and floating mats in the lake areas at depths up to 30 cm was in a stable range of values from 100 to 290 mg(dry weight)/cm2. Animal and infusorian average abundance in mats reach high values: infusorians—up to 15 000 000 ind./m2, Cletocamptus retrogressus(Copepoda, Harpacticoida)—up to 730 000 ind./m2, Eucypris mareotica(Ostracoda)—up to 91 000 ind./m2 and Chironomidae larvae(Insecta, Diptera)—up to 140 ind./m2. Those values were much higher than in the plankton.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
Poly(vinyl alcohol) (PVA) fiber mats containing 20 and 80 wt% H3PW12O40 were prepared by using electrospinning technique. The fiber mats were characterized by IR, XRD spectra and scanning electron microscope (SEM). ...Poly(vinyl alcohol) (PVA) fiber mats containing 20 and 80 wt% H3PW12O40 were prepared by using electrospinning technique. The fiber mats were characterized by IR, XRD spectra and scanning electron microscope (SEM). The diameter of the fiber mats is ca. 400 nm.展开更多
The well-preserved Mesoproterozoic succession in the North China platform consists mainly of three iithological associations including peritidal quartz sandstone, shallow marine and lagoonal dark to black shales, and ...The well-preserved Mesoproterozoic succession in the North China platform consists mainly of three iithological associations including peritidal quartz sandstone, shallow marine and lagoonal dark to black shales, and shallow epeiric carbonates, with a total thickness of up to 8 000 m. In addition to well-documented microplants, macroalgae, and microbial buildups, abundant microbially induced sedimentary structures （MISS） and mat-related sediments have been recognized in these rocks. Intensive microbial mat layers and MISS are especially well preserved in the carbonates of the upper Gaoyuzhuang （高于庄） （ca. 1.5 Ga） and lower Wumishan （雾迷山） （ca. 1.45 Ga） formations, indicating diversified microbial activities and a high organic production. In these petrified biomats, putative microbial fossils （both coccoidal and filamentous） and framboidal pyrites have been identified. The abundance of authigenic carbonate minerals in the host rocks, such as, acicular aragonites, rosette barites, radial siderites, ankerites, and botryoidal carbonate cements, suggests authigenic carbonate precipitation from anaerobic oxidation of methane （AOM） under anoxic/euxinic conditions. Warm climate and anoxic/euxinic conditions in the Mesoproterozoic oceans may have facilitated high microbial productivity and organic burial in sediments. Although authigenic carbonate cements may record carbonate precipitation from anaerobic methane oxidation, gas blister （or dome） structures may indicate gas release from active methanogenesis during shallow burial. Bituminous fragments in mat-related carbonates also provide evidence for hydrocarbon generation. Under proper conditions, the Mesoproterozoic mat-rich carbonates will have the potential for hydrocarbon generation and serve as source rocks. On the basis of petrified biomats, a rough estimation suggests that the Mesoproterozoic carbonates of the North China platform might have a hydrocarbon production potential in the order of 10 ×10^8 t.展开更多
Tar mats were firstly discovered and determined accurately in terrestrial oil and gas reservoirs associated with Lower Tertiary sandstone reservoirs in the Yaha field of the Tarim Basin, China, by thin layer chromatog...Tar mats were firstly discovered and determined accurately in terrestrial oil and gas reservoirs associated with Lower Tertiary sandstone reservoirs in the Yaha field of the Tarim Basin, China, by thin layer chromatography flame ionization detector (TLC FID) and Rock Eval analysis. The relative content of asphaltene in gross composition of tar mat extracts accounts for more than 30%, that in the corresponding oil leg less than 20%. In the geochemical description profile of oil and gas reservoirs, drastic changes in asphaltene contents between tar mats and oil legs could be discovered. This is an important marker to determine tar mats. Distribution characteristics of saturated and aromatic hydrocarbons from reservoir core extracts and crude oils in the Yaha oil and gas reservoirs in the Tarim Basin are described systematically in this paper, and the results show there are similarities among n alkane distribution characteristics, biomarker distribution characteristics and their combined characteristics of saturated hydrocarbons, and the geochemical characteristics of aromatic hydrocarbons for tar mats, oil leg, asphaltic sand and crude oil. These characteristics suggest the hydrocarbons in these samples were originated from the common source rocks. However, the geochemical characteristics of tar mats revealed that the mechanism of formation of tar mats is the precipitation of asphaltene from crude oils in petroleum reservoirs caused by increased dissolved gas in oil legs (gas injection).展开更多
Composite nanofibrous mats consisting of poly( L-lactideco-ε-caprolactone)( PLCL) and collagen type I( COL) were fabricated by electrospinning,and ten times simulated body fluid(10SBF) were employed to mineralize nan...Composite nanofibrous mats consisting of poly( L-lactideco-ε-caprolactone)( PLCL) and collagen type I( COL) were fabricated by electrospinning,and ten times simulated body fluid(10SBF) were employed to mineralize nanofibrous mats. Ballshaped hydroxyapatite( HA) was deposited on the surface of nanofibrous mats in 1. 5 h at room temperature. Human fetal osteoblasts( hFob) were seeded to investigate their proliferation and differentiation on mineralized composite nanofibrous mats. The results showed that hFob grew well on mineralized composite nanofibrous mats and alkaline phosphatase( ALP) activity of hFob on mineralized composite nanofibrous mats at 14 d was much higher than that on untreated nanofibrous mats. Moreover,the expression of osteocalcin of cells on mineralized composite nanofibrous mats was also much higher than those on untreated nanofibrous mats at 7 d and 14 d. This mineralized composite nanofibrous mats may have a great potential for bone tissue engineering.展开更多
Microbial mats are organo-sedimentary ecosystems formed by autotrophic and heterotrophic bacterias. Cyanobacteria contribute to the formation of these structures from the entrapment and engulfment of sediments contrib...Microbial mats are organo-sedimentary ecosystems formed by autotrophic and heterotrophic bacterias. Cyanobacteria contribute to the formation of these structures from the entrapment and engulfment of sediments contributing to the formation of carbonate rocks found in the geological record from the Precambrian to the Recent. In this research we identified the living cyanobacteria mats type 1 (gelatinous) and type 2 (cohesives) present in Brejo do Espinho and Araruama saline, east Fluminense, Rio de Janeirostate. The microbial mats type 1, were found in compartiment A and B of Brejo do Espinho and the Araruama saline in the tank with a depth of10 cm. The mats type 2 were only found in compartiment A and in tank with15 cmdepth. In the microbial mats of compartiments A and B predominated the spherical forms of genres Chroococcus Nageli 1948 and Aphanothece Nageli1948. Inthe tanks predominated filamentous forms of the Leptolyngbya Anagnostidis and Komárek 1988 genre. In mats type 1, the diversity indices (H') were 1.95 and 2.24 and in type 2 of 2.16 and 2.14 for the Brejo do Espinho and Araruama saline, respectively. The highest values of diversity indices found in saline tanks occurred by stable salinity conditions.展开更多
From July 22 to 25,"2022 Discover China CulturalTour"participatedbyforeign diplomats in China hosted by the Ministry of Culture and Tourism entered into the Colorful Yunnan.18ambassadors andotherdiplomats fr...From July 22 to 25,"2022 Discover China CulturalTour"participatedbyforeign diplomats in China hosted by the Ministry of Culture and Tourism entered into the Colorful Yunnan.18ambassadors andotherdiplomats from11countries jointly initiated the1st station event of the themed route of"2022 Discover China Cultural Tour".展开更多
基金Fundamental Research Funds for the Central Universities,China(No. 2232022D-13)Fundamental Research Funds of Shanghai Collaborative Innovation Center of High Performance Fibers and Composites (Province-M inistry Joint),China(No. X12812101/015)。
文摘To reduce the environmental pollution and meet the needs for wearable electronic devices, new requirements for electromagnetic interference(EMI) shielding materials include flexibility, biodegradability, and biocompatibility. Herein, we reported a polypyrrole-coated zein/epoxy(PPy/ZE) ultrafine fiber mat which was inherently biodegradable and skin-friendly. In addition, it could maintain its ultrafine fibrous structure after coating, which could provide the mat with mechanical compliance, high porosity, and a large specific area for high EMI shielding. With the assistance of the epoxide cross-linking, the breaking stresses of the PPy/ZE fiber mats could achieve 3.3 MPa and 1.4 MPa and the strains were 40.1% and 83.0% in dry and wet states, respectively, which met the needs of various wearable electronic devices. Along with the extension in the PPy treatment duration, more PPy was loaded on the fiber surfaces, which formed more integrated and conductive paths to generate increasing conductivities up to 401.76 S·m^(-1). Moreover, the EMI shielding performance was raised to 26.84 dB. The biobased mats provide a green and efficient choice for EMI shielding materials, which may be a promising strategy to address EMI problems in multiple fields.
基金support of the Russian Academy of Sciences for the A.O.Kovalevsky Institute of Marine Biological Research of RAS
文摘Filamentous green algae play an important functional role in element cycling and productivity in the diff erent water bodies. In hypersaline lakes and lagoons of the Crimea, filamentous green algae are present and form bottom and floating mats that occupy large areas with high biomass, up to 4–5 kg(wet biomass)/m2. Cladophora spp. dominated in those mats. Five species of filamentous green algae(Chlorophyta) in Lake Chersonesskoye: C ladophora vadorum(Aresch.) Kütz., C. siwaschensis C. Meyer, C. echinus(Biasol.) Kütz., Ulothrix implexa(Kütz.) Kütz., Rhizoclonium tortuosum(Dillw.) Kütz., and seagrass(Angiospermae) R uppia cirrhosa(Petagna) Grande were found. Cladophora spp. and R. cirrhosa were found in the lake throughout the year, other types of algae were encountered episodically. In most cases the biomass of bottom mat exceeded that of the floating mat. In general, the total biomass of the bottom and floating mats in the lake areas at depths up to 30 cm was in a stable range of values from 100 to 290 mg(dry weight)/cm2. Animal and infusorian average abundance in mats reach high values: infusorians—up to 15 000 000 ind./m2, Cletocamptus retrogressus(Copepoda, Harpacticoida)—up to 730 000 ind./m2, Eucypris mareotica(Ostracoda)—up to 91 000 ind./m2 and Chironomidae larvae(Insecta, Diptera)—up to 140 ind./m2. Those values were much higher than in the plankton.
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.
文摘Poly(vinyl alcohol) (PVA) fiber mats containing 20 and 80 wt% H3PW12O40 were prepared by using electrospinning technique. The fiber mats were characterized by IR, XRD spectra and scanning electron microscope (SEM). The diameter of the fiber mats is ca. 400 nm.
基金supported by the SINOPEC project (G0800-06-ZS-319)the National Natural Science Foundation of China (No. 40621002)the Ministry of Education of China (IRT00546, B0711)
文摘The well-preserved Mesoproterozoic succession in the North China platform consists mainly of three iithological associations including peritidal quartz sandstone, shallow marine and lagoonal dark to black shales, and shallow epeiric carbonates, with a total thickness of up to 8 000 m. In addition to well-documented microplants, macroalgae, and microbial buildups, abundant microbially induced sedimentary structures （MISS） and mat-related sediments have been recognized in these rocks. Intensive microbial mat layers and MISS are especially well preserved in the carbonates of the upper Gaoyuzhuang （高于庄） （ca. 1.5 Ga） and lower Wumishan （雾迷山） （ca. 1.45 Ga） formations, indicating diversified microbial activities and a high organic production. In these petrified biomats, putative microbial fossils （both coccoidal and filamentous） and framboidal pyrites have been identified. The abundance of authigenic carbonate minerals in the host rocks, such as, acicular aragonites, rosette barites, radial siderites, ankerites, and botryoidal carbonate cements, suggests authigenic carbonate precipitation from anaerobic oxidation of methane （AOM） under anoxic/euxinic conditions. Warm climate and anoxic/euxinic conditions in the Mesoproterozoic oceans may have facilitated high microbial productivity and organic burial in sediments. Although authigenic carbonate cements may record carbonate precipitation from anaerobic methane oxidation, gas blister （or dome） structures may indicate gas release from active methanogenesis during shallow burial. Bituminous fragments in mat-related carbonates also provide evidence for hydrocarbon generation. Under proper conditions, the Mesoproterozoic mat-rich carbonates will have the potential for hydrocarbon generation and serve as source rocks. On the basis of petrified biomats, a rough estimation suggests that the Mesoproterozoic carbonates of the North China platform might have a hydrocarbon production potential in the order of 10 ×10^8 t.
文摘Tar mats were firstly discovered and determined accurately in terrestrial oil and gas reservoirs associated with Lower Tertiary sandstone reservoirs in the Yaha field of the Tarim Basin, China, by thin layer chromatography flame ionization detector (TLC FID) and Rock Eval analysis. The relative content of asphaltene in gross composition of tar mat extracts accounts for more than 30%, that in the corresponding oil leg less than 20%. In the geochemical description profile of oil and gas reservoirs, drastic changes in asphaltene contents between tar mats and oil legs could be discovered. This is an important marker to determine tar mats. Distribution characteristics of saturated and aromatic hydrocarbons from reservoir core extracts and crude oils in the Yaha oil and gas reservoirs in the Tarim Basin are described systematically in this paper, and the results show there are similarities among n alkane distribution characteristics, biomarker distribution characteristics and their combined characteristics of saturated hydrocarbons, and the geochemical characteristics of aromatic hydrocarbons for tar mats, oil leg, asphaltic sand and crude oil. These characteristics suggest the hydrocarbons in these samples were originated from the common source rocks. However, the geochemical characteristics of tar mats revealed that the mechanism of formation of tar mats is the precipitation of asphaltene from crude oils in petroleum reservoirs caused by increased dissolved gas in oil legs (gas injection).
基金"111 Project"Biomedical Textile Materials Science and Technology,China(No.B07024)National Natural Science Foundations of China(No.31070871,No.31271035)+2 种基金National Medical Research Council,China(No.NMRC/1151/2008)Technologies Bureau of Jiaxing City,China(No.MTC2012-006,No.2011A Y1026)Science and Technology Agency of Zhejiang Province,China(No.2012R10012-09)
文摘Composite nanofibrous mats consisting of poly( L-lactideco-ε-caprolactone)( PLCL) and collagen type I( COL) were fabricated by electrospinning,and ten times simulated body fluid(10SBF) were employed to mineralize nanofibrous mats. Ballshaped hydroxyapatite( HA) was deposited on the surface of nanofibrous mats in 1. 5 h at room temperature. Human fetal osteoblasts( hFob) were seeded to investigate their proliferation and differentiation on mineralized composite nanofibrous mats. The results showed that hFob grew well on mineralized composite nanofibrous mats and alkaline phosphatase( ALP) activity of hFob on mineralized composite nanofibrous mats at 14 d was much higher than that on untreated nanofibrous mats. Moreover,the expression of osteocalcin of cells on mineralized composite nanofibrous mats was also much higher than those on untreated nanofibrous mats at 7 d and 14 d. This mineralized composite nanofibrous mats may have a great potential for bone tissue engineering.
文摘Microbial mats are organo-sedimentary ecosystems formed by autotrophic and heterotrophic bacterias. Cyanobacteria contribute to the formation of these structures from the entrapment and engulfment of sediments contributing to the formation of carbonate rocks found in the geological record from the Precambrian to the Recent. In this research we identified the living cyanobacteria mats type 1 (gelatinous) and type 2 (cohesives) present in Brejo do Espinho and Araruama saline, east Fluminense, Rio de Janeirostate. The microbial mats type 1, were found in compartiment A and B of Brejo do Espinho and the Araruama saline in the tank with a depth of10 cm. The mats type 2 were only found in compartiment A and in tank with15 cmdepth. In the microbial mats of compartiments A and B predominated the spherical forms of genres Chroococcus Nageli 1948 and Aphanothece Nageli1948. Inthe tanks predominated filamentous forms of the Leptolyngbya Anagnostidis and Komárek 1988 genre. In mats type 1, the diversity indices (H') were 1.95 and 2.24 and in type 2 of 2.16 and 2.14 for the Brejo do Espinho and Araruama saline, respectively. The highest values of diversity indices found in saline tanks occurred by stable salinity conditions.
文摘From July 22 to 25,"2022 Discover China CulturalTour"participatedbyforeign diplomats in China hosted by the Ministry of Culture and Tourism entered into the Colorful Yunnan.18ambassadors andotherdiplomats from11countries jointly initiated the1st station event of the themed route of"2022 Discover China Cultural Tour".
