This paper reports on two years of measurement of soil respiration and canopy-root biomass in a Leymus chinensis community in the Xilin River basin of Inner Mongolia. Correlations between components of plant biomass a...This paper reports on two years of measurement of soil respiration and canopy-root biomass in a Leymus chinensis community in the Xilin River basin of Inner Mongolia. Correlations between components of plant biomass and soil respiration rates were examined. From respiration data based on CO2 uptake by NaOH and corresponding root biomass values for each run of 10 plots, a linear regression of CO2 evolution rates on root dry weights has been achieved for every ten days. By applying the approach of extrapolating the regressive line to zero root biomass, the proportion of the total soil respiration flux that is attributable to live root respiration was estimated to be about 27% on average, ranging from 14% to 39% in the growing season in 1998. There were no evident relations between the total canopy biomass or root biomass and CO2 evolution rates, but a significant exponential relation did exist between tire live-canopy biomass and CO2 evolution rates.展开更多
Fossil woods were collected from the Upper Cretaceous to Paleocene beds distributed around Heilong- jang （Amur） River area of China and Russia. A total of 43 specimens were collected from Baishantou, Long- gushan, a...Fossil woods were collected from the Upper Cretaceous to Paleocene beds distributed around Heilong- jang （Amur） River area of China and Russia. A total of 43 specimens were collected from Baishantou, Long- gushan, and Yong＇ancun in Jiayin, China, and 85 specimens from Zeya-Bureya Basin lying southeast of Blagoveshchensk in Russia. Selected specimens were sectioned and studied anatomically. The source deposits of almost all identifiable specimens belong to the Upper Cretaceous （Campanian） Taipinglinchang Formation and the Paleocene Wuyun Formation in China, and the Paleocene Upper Tsagayan Formation in Russia. Al- though the results obtained are still far from complete, the taxonomic composition of the fossil woods show marked stratigraphic differences between the two horizons beyond the K/T boundary in China. There is also a strong similarity in wood flora between the Wuyun Formation of China and the Upper Tsagayan Formation of Russia. All identified specimens from the Taipinglinchang Formation are Xenoxylon latiporosum, This is one of the stratigraphically younger records of Xenoxylon, which is a conifer morphogenus of uncertain affinity most common in the Triassic to Early Cretaceous. Only one specimen with possible derivation from either the Wuyun or the Maastriehtian Furao Formation in China was identified as Taxodioxylon sp. The Wuyun Formation yielded both conifers and dicotyledonous woods. The conifers include Taxodioxylon sequoianum of the Taxodiaceae, and Protopiceoxylon amurense, which is attributable to the extant genera Keteleeria or Nothotsuga of the Pinaeeac, both are at present endemic to China. At least two morphotypes of dicotyledonous woods were recognized, with one identified as el. Hamamelidoxylon , and the other diffuse porous wood is characterized by numerous heterogeneous rays. From the Zeya-Buleya Basin of Russia, Taxodioxylon sequoianum and cf. Hamamelidoxylon sp. were identified from the Upper Tsagayan Formation. The similarity of wood composition in both Wuyun and Upper Tsagayan Formations support lithological as well as biostratigraphic correlations proposed for the two formations.展开更多
Although the quantification and valuation of ecosystem services have been studied for a long time, few studies have specifi- cally focused on the quantification of tradeoffs between ecosystem services and tradeoff hot...Although the quantification and valuation of ecosystem services have been studied for a long time, few studies have specifi- cally focused on the quantification of tradeoffs between ecosystem services and tradeoff hotspots, Based on previous studies of ecosys- tem service assessment, we proposed a feasible method to analyze the tradeoffs between ecosystem services, including determination of their relationship, quantification of tradeoffs, and identification of tradeoff hotspots. Potential influencing factors were then further ana- lyzed. The Yanhe Basin in the Loess Plateau was selected as an example to demonstrate the application process. Firstly, the amounts of net primary production （NPP） and water yield （WY） in 2000 and 2008 were estimated by using biophysical models, Secondly, correla- tion analysis was used to indicate the tradeoffs between NPP and WY. Thirdly, tradeoff index （TINpp/wy） was established to quantify the extent of tradeoffs between NPP and WY, and the average value of TINpp/wy is 24.4 g/（mm·m2） for the Yanhe Basin between 2000 and 2008. Finally, the tradeoff hotspots were identified. The results indicated that the area of lowest tradeoff index concentrated in the mid- dle part of the Yanhe Basin and marginal areas of the southern basin. Map overlapping was used for preliminary analysis to seek poten- tial influencing factors, and the results showed that shrub was the best suited for growing in the Yanhe Basin, but also was a potential irtfluencing factor for formulatiort of the tradeoff hotspots. The concept of tradeoff index could also be used to quantify the degree of synergy between different ecosystem services. The method to identify the tradeoff hotspots could help us to narrow the scope of study area for further research on the relationship among ecosystem services and concentrate on the potential factors for formation of tradeoff between ecosystem services, enhance the capacity to maintain the sustainability of ecosystem.展开更多
Ammonia is one of the basin indices which are nation-controlled in the waterenvironmental management. In order to assess the differences of ammonia criteria indifferent basins, 7 major basins are used for the study ob...Ammonia is one of the basin indices which are nation-controlled in the waterenvironmental management. In order to assess the differences of ammonia criteria indifferent basins, 7 major basins are used for the study object, including Songhua River,Liaohe River, Haihe River, Yellow River, Huaihe River, Yangtze River and ZhujiangRiver, referring the water environmental criteria technology of the United StatesEnvironmental Protection Agency, based on the effects of water characteristics on theecotoxicity of ammonia, and in summer and non-summer situation, aquatic life criteriais derived for ammonia. The results showed that: (a) The differences between thecriteria values in different basins and different seasons were significant. The differencesbetween the criteria values in different basins were greater than 6 times, while those indifferent seasons in the same basin were greater than 2 times. (b) The summer acuteand chronic criteria for Huaihe River were 0.37 mg/L and 0.06 mg/L while thenon-summer values were 0.81 mg/L and 0.15 mg/L. Both the summer and thenon-summer values were lowest in all of the seven basins. (c) The preliminaryassessment of Ammonia exposure ecological risk indicated that was the lowest inZhujiang River, and it was much lower in Songhua River, Liaohe River and YangtzeRiver, and was higher in Yellow River, and the highest in both Haihe River and HuaiheRiver. Haihe River has 7 sections while 2 in high risk, and Huaihe River has 27 sectionswhile sixteen in high risk. According to the differences of the criteria values for ammoniain seven basins in different seasons and difference of ammonia ecological riskassessment, it is suggested that it should be managed by different policies.展开更多
This study analyzes the vegetative and soil degradation,measured as biomass and soil loss,for Arnigad micro-watershed located in Indian Himalayan state of Uttarakhand,in systems framework by using dynamic linear progr...This study analyzes the vegetative and soil degradation,measured as biomass and soil loss,for Arnigad micro-watershed located in Indian Himalayan state of Uttarakhand,in systems framework by using dynamic linear programming bio-economic model.The focus is at investigating the effects of alternate policy regimes,i.e.,introduction of improved energy sources for cooking along with substitution of existing local livestock breeds with improved breed,reduction in human population growth and introduction of high yielding varieties of main crops including paddy,maize and wheat.The model horizon extended over a period of 25 years,i.e.,from 2006 to 2030.It was found that the model scenario incorporating increased use of improved energy sources along with substitution of local cows by improved cows could be the most effective policy option in reducing vegetative and soil degradation.The vegetative biomass density declined to 19.76% compared to 35.24% in the BASE scenario and soil erosion loss was also lowered by 29.13%.Also,the reduction of population growth rate to half of the BASE scenario led to minor improvements in degradation.Introduction of high yielding varieties of main crops slightly increased vegetative degradation but reduced soil loss(8.35%) with respect to the BASE scenario.Such a phenomenon could be explained in terms of changed crop mix resulting in reduced amount of crop by-products requiring increased lopping of tree branches for animal fodder.The policy option of the increased use of improved energy sources along with substitution of improved breed of cows resulted in 9.58% higher income.Introduction of high yielding varieties of crops led to 1.92% increase in income,but the income decreased by 1.25 % when population growth was reduced to half.The usefulness of the model lies in analyzing the systems behavior in its entirety where the results can predict the possible direction of change as a result of manipulation in alternate economic regimes.展开更多
This study aims to determine the relationships between local meteorological conditions,proglacial river discharge and biogeochemical processes operating in a periglacial basin located in the Polar Ural mountain range,...This study aims to determine the relationships between local meteorological conditions,proglacial river discharge and biogeochemical processes operating in a periglacial basin located in the Polar Ural mountain range, Russia. Fieldwork was conducted in the catchment of Obruchev Glacier(13 km2) during the summer peak flow period in 2008. River discharge was dominated by snowmelt and changed from 3300 l s-1 to less than 1000 l s-1. The mean daily air temperatures of stations situated in the mountain tundra and near Obruchev Glacier from July 11 th to August 1st 2008 were 14.4°C and 10.3°C, respectively. The glacial river had low total dissolved solids varying from 4.5 to 9 mg l-1 and coefficients of correlation between Na+ and Cl-, K+ and Cl-, as well as NH4+ and Cl- were 0.94, 0.90 and 0.84, respectively. Rainfall events affected the snowmelt initiation and provided an essential part of the discharge during the intense snowmelt period, which occurred from July 11 th to July 18 th 2008. Data showed that Na+ and K+ in the surface water derived from snowmelt rather than chemical weathering of silicates. Also, it was obtained that NO3- derived from the melting snowpack, whereas ammonification occurring under the snowpacks was the primary source for NH4+.展开更多
The authors assessed if wetlands can contribute to flood damage reduction in the Red River Basin, Minnesota, by providing reliable flood water storage. Hydrology and biodiversity in 28 natural and restored wetlands su...The authors assessed if wetlands can contribute to flood damage reduction in the Red River Basin, Minnesota, by providing reliable flood water storage. Hydrology and biodiversity in 28 natural and restored wetlands suggested uncontrolled natural wetlands provided the highest mean annual flood storage at 15 cm of runoff while single and 2-stage outlet controlled wetlands provided 3.0 and 8.1 cm of runoff control. Natural controlled wetlands, followed by 2-stage and single stage outlet controlled restorations provided 10.2, 6.6, and 2.2 cm of storage for early summer storm events. Two years of recorded water levels and a 20-year continuous meteorological record were used to model ＂temporary water level increases＂ in each wetland. Species diversity, hydrology, and watershed land use variables are inversely related where high quality and diverse wetlands had the lowest amplitude and frequency of water level increases, while low quality wetlands had the highest. Uncontrolled natural wetlands had the highest biological diversity and the lowest frequency and magnitude of temporary water levels increased. A significant biodiversity declines were measured where water level increases were greater than 2.7 meters. Strong multi-linear relationships between watershed land uses and watershed/wetland ratio explained wetland hydraulic performance and biodiversity relations （r2 ranging from 0.6-0.8）. Non-native wetland plant diversity increased with greater water level dynamics.展开更多
Biological ion channels show that ultrafast ions and molecules transmission are in a quantum way of single molecular or ionic chain with a certain number of molecules or ions, and we define it as ＂quantum-confined su...Biological ion channels show that ultrafast ions and molecules transmission are in a quantum way of single molecular or ionic chain with a certain number of molecules or ions, and we define it as ＂quantum-confined superfluid＂ （QSF）. This ordered ultrafast flow in the confined channel can be considered as ＂quantum tunneling fluid effect＂ with a ＂tunneling distance＂, which is corresponding to the period of QSF. Recent research demonstrated that artificial biomimetic nanochannels also showed the phenomenon of QSF, such as ion and water channels. The introduction of QSF concept in the fields of chemistry and biology may create significant impact. As for chemistry, the QSF effect provides new ideas for accurate synthesis in organic, inorganic, polymer, etc. We believe the implementation of the idea of QSF will promote the development of QSF biochemistry, biophysics, bioinformatics and biomedical science.展开更多
Concentrations of suspended particle material(SPM), dissolved silicate(DSi), biogenic silica(BSi), phytoliths(plant produced siliceous microscopic structures), and other parameters were analyzed to examine the influen...Concentrations of suspended particle material(SPM), dissolved silicate(DSi), biogenic silica(BSi), phytoliths(plant produced siliceous microscopic structures), and other parameters were analyzed to examine the influence of both natural processes and human activities on silica delivery to the estuary of the Huanghe River(Yellow River). Our results indicate that the concentrations of DSi in the river decreased significantly since 1986. Approximately 34% of dissolved silica was trapped in the basin between 1986 and 2010 due to a reduction of soil erosion. Phytoliths comprised 67.2%–96.3% of BSi, with the smoothing bar type being the dominant form. Concentrations of BSi are significantly higher in the Huanghe River compared to other major rivers throughout the world due to its high sediment yield. We also found that the ratios of BSi/(BSi+DSi) and BSi/SPM were approximately 0.5 and 0.003 at Lijin near the river mouth, indicating that BSi carried in suspension by the Huanghe River was an important component of the rivers silica load. Significant amounts of BSi were also composed of phytoliths in Bohai Sea sediments near the Huanghe River estuary with the smoothing bar form again being the most abundant. The relatively high specific fluxes of BSi in the Huanghe River reflect its high turbidity and high erosion rates in the basin. The high sediment load originating on the Loess Plateau is likely responsible for the higher BSi flux, in agreement with a general trend of increasing BSi flux with increasing sediment flux in global river systems. This study demonstrates that BSi transported by rivers can be composed largely of phytoliths originating from the erosion of topsoils. The flux of phytoliths in river's suspended sediment load may therefore represent a significant contribution to the biogeochemical cycle of silica in coastal waters.展开更多
Microfluidic technology provides opportunities to create in vitro models with physiological microenvironment for cell study.Introducing the identified key aspects,including tissue-tissue interfaces,spatiotemporal chem...Microfluidic technology provides opportunities to create in vitro models with physiological microenvironment for cell study.Introducing the identified key aspects,including tissue-tissue interfaces,spatiotemporal chemical gradients,and dynamic mechanical forces,of living organs into the microfluidic system,"organs-on-chips"display an unprecedented application potential in a lot of biological fields such as fundamental physiological and pathophysiological research,drug efficacy and toxicity testing,and clinical diagnosis.Here,we review the recent development of organs-on-chips and briefly discuss their future challenges.展开更多
文摘This paper reports on two years of measurement of soil respiration and canopy-root biomass in a Leymus chinensis community in the Xilin River basin of Inner Mongolia. Correlations between components of plant biomass and soil respiration rates were examined. From respiration data based on CO2 uptake by NaOH and corresponding root biomass values for each run of 10 plots, a linear regression of CO2 evolution rates on root dry weights has been achieved for every ten days. By applying the approach of extrapolating the regressive line to zero root biomass, the proportion of the total soil respiration flux that is attributable to live root respiration was estimated to be about 27% on average, ranging from 14% to 39% in the growing season in 1998. There were no evident relations between the total canopy biomass or root biomass and CO2 evolution rates, but a significant exponential relation did exist between tire live-canopy biomass and CO2 evolution rates.
基金NSFC Project 30220130698 to G. S.the Grant-in-Aid for Scientific Research no.1425507 from the Ministry of Education,Culture,Sports,Science and Technology of Japan to H.N.
文摘Fossil woods were collected from the Upper Cretaceous to Paleocene beds distributed around Heilong- jang （Amur） River area of China and Russia. A total of 43 specimens were collected from Baishantou, Long- gushan, and Yong＇ancun in Jiayin, China, and 85 specimens from Zeya-Bureya Basin lying southeast of Blagoveshchensk in Russia. Selected specimens were sectioned and studied anatomically. The source deposits of almost all identifiable specimens belong to the Upper Cretaceous （Campanian） Taipinglinchang Formation and the Paleocene Wuyun Formation in China, and the Paleocene Upper Tsagayan Formation in Russia. Al- though the results obtained are still far from complete, the taxonomic composition of the fossil woods show marked stratigraphic differences between the two horizons beyond the K/T boundary in China. There is also a strong similarity in wood flora between the Wuyun Formation of China and the Upper Tsagayan Formation of Russia. All identified specimens from the Taipinglinchang Formation are Xenoxylon latiporosum, This is one of the stratigraphically younger records of Xenoxylon, which is a conifer morphogenus of uncertain affinity most common in the Triassic to Early Cretaceous. Only one specimen with possible derivation from either the Wuyun or the Maastriehtian Furao Formation in China was identified as Taxodioxylon sp. The Wuyun Formation yielded both conifers and dicotyledonous woods. The conifers include Taxodioxylon sequoianum of the Taxodiaceae, and Protopiceoxylon amurense, which is attributable to the extant genera Keteleeria or Nothotsuga of the Pinaeeac, both are at present endemic to China. At least two morphotypes of dicotyledonous woods were recognized, with one identified as el. Hamamelidoxylon , and the other diffuse porous wood is characterized by numerous heterogeneous rays. From the Zeya-Buleya Basin of Russia, Taxodioxylon sequoianum and cf. Hamamelidoxylon sp. were identified from the Upper Tsagayan Formation. The similarity of wood composition in both Wuyun and Upper Tsagayan Formations support lithological as well as biostratigraphic correlations proposed for the two formations.
基金Under the auspices of National Natural Sciences Foundation of China(No.41230745)Major Program of High Resolution Earth Observation System(No.30-Y30B13-9003-14/16-02)
文摘Although the quantification and valuation of ecosystem services have been studied for a long time, few studies have specifi- cally focused on the quantification of tradeoffs between ecosystem services and tradeoff hotspots, Based on previous studies of ecosys- tem service assessment, we proposed a feasible method to analyze the tradeoffs between ecosystem services, including determination of their relationship, quantification of tradeoffs, and identification of tradeoff hotspots. Potential influencing factors were then further ana- lyzed. The Yanhe Basin in the Loess Plateau was selected as an example to demonstrate the application process. Firstly, the amounts of net primary production （NPP） and water yield （WY） in 2000 and 2008 were estimated by using biophysical models, Secondly, correla- tion analysis was used to indicate the tradeoffs between NPP and WY. Thirdly, tradeoff index （TINpp/wy） was established to quantify the extent of tradeoffs between NPP and WY, and the average value of TINpp/wy is 24.4 g/（mm·m2） for the Yanhe Basin between 2000 and 2008. Finally, the tradeoff hotspots were identified. The results indicated that the area of lowest tradeoff index concentrated in the mid- dle part of the Yanhe Basin and marginal areas of the southern basin. Map overlapping was used for preliminary analysis to seek poten- tial influencing factors, and the results showed that shrub was the best suited for growing in the Yanhe Basin, but also was a potential irtfluencing factor for formulatiort of the tradeoff hotspots. The concept of tradeoff index could also be used to quantify the degree of synergy between different ecosystem services. The method to identify the tradeoff hotspots could help us to narrow the scope of study area for further research on the relationship among ecosystem services and concentrate on the potential factors for formation of tradeoff between ecosystem services, enhance the capacity to maintain the sustainability of ecosystem.
基金supported by the National Water Pollution Control and Treatment Science and Technology Major Project(Grant No.2012ZX07501-003)Science and technology basic work(Grant No.2014FY120606)
文摘Ammonia is one of the basin indices which are nation-controlled in the waterenvironmental management. In order to assess the differences of ammonia criteria indifferent basins, 7 major basins are used for the study object, including Songhua River,Liaohe River, Haihe River, Yellow River, Huaihe River, Yangtze River and ZhujiangRiver, referring the water environmental criteria technology of the United StatesEnvironmental Protection Agency, based on the effects of water characteristics on theecotoxicity of ammonia, and in summer and non-summer situation, aquatic life criteriais derived for ammonia. The results showed that: (a) The differences between thecriteria values in different basins and different seasons were significant. The differencesbetween the criteria values in different basins were greater than 6 times, while those indifferent seasons in the same basin were greater than 2 times. (b) The summer acuteand chronic criteria for Huaihe River were 0.37 mg/L and 0.06 mg/L while thenon-summer values were 0.81 mg/L and 0.15 mg/L. Both the summer and thenon-summer values were lowest in all of the seven basins. (c) The preliminaryassessment of Ammonia exposure ecological risk indicated that was the lowest inZhujiang River, and it was much lower in Songhua River, Liaohe River and YangtzeRiver, and was higher in Yellow River, and the highest in both Haihe River and HuaiheRiver. Haihe River has 7 sections while 2 in high risk, and Huaihe River has 27 sectionswhile sixteen in high risk. According to the differences of the criteria values for ammoniain seven basins in different seasons and difference of ammonia ecological riskassessment, it is suggested that it should be managed by different policies.
基金a part of research project:An Interdisciplinary Approach to Analyze the Dynamics of Forest and Soil Degradation and to Develop Sustainable Agro-ecological Strategies for Fragile Himalayan Watersheds,funded by the European Union
文摘This study analyzes the vegetative and soil degradation,measured as biomass and soil loss,for Arnigad micro-watershed located in Indian Himalayan state of Uttarakhand,in systems framework by using dynamic linear programming bio-economic model.The focus is at investigating the effects of alternate policy regimes,i.e.,introduction of improved energy sources for cooking along with substitution of existing local livestock breeds with improved breed,reduction in human population growth and introduction of high yielding varieties of main crops including paddy,maize and wheat.The model horizon extended over a period of 25 years,i.e.,from 2006 to 2030.It was found that the model scenario incorporating increased use of improved energy sources along with substitution of local cows by improved cows could be the most effective policy option in reducing vegetative and soil degradation.The vegetative biomass density declined to 19.76% compared to 35.24% in the BASE scenario and soil erosion loss was also lowered by 29.13%.Also,the reduction of population growth rate to half of the BASE scenario led to minor improvements in degradation.Introduction of high yielding varieties of main crops slightly increased vegetative degradation but reduced soil loss(8.35%) with respect to the BASE scenario.Such a phenomenon could be explained in terms of changed crop mix resulting in reduced amount of crop by-products requiring increased lopping of tree branches for animal fodder.The policy option of the increased use of improved energy sources along with substitution of improved breed of cows resulted in 9.58% higher income.Introduction of high yielding varieties of crops led to 1.92% increase in income,but the income decreased by 1.25 % when population growth was reduced to half.The usefulness of the model lies in analyzing the systems behavior in its entirety where the results can predict the possible direction of change as a result of manipulation in alternate economic regimes.
基金supported by the Institute of Geography and Spatial Management at Jagiellonian University
文摘This study aims to determine the relationships between local meteorological conditions,proglacial river discharge and biogeochemical processes operating in a periglacial basin located in the Polar Ural mountain range, Russia. Fieldwork was conducted in the catchment of Obruchev Glacier(13 km2) during the summer peak flow period in 2008. River discharge was dominated by snowmelt and changed from 3300 l s-1 to less than 1000 l s-1. The mean daily air temperatures of stations situated in the mountain tundra and near Obruchev Glacier from July 11 th to August 1st 2008 were 14.4°C and 10.3°C, respectively. The glacial river had low total dissolved solids varying from 4.5 to 9 mg l-1 and coefficients of correlation between Na+ and Cl-, K+ and Cl-, as well as NH4+ and Cl- were 0.94, 0.90 and 0.84, respectively. Rainfall events affected the snowmelt initiation and provided an essential part of the discharge during the intense snowmelt period, which occurred from July 11 th to July 18 th 2008. Data showed that Na+ and K+ in the surface water derived from snowmelt rather than chemical weathering of silicates. Also, it was obtained that NO3- derived from the melting snowpack, whereas ammonification occurring under the snowpacks was the primary source for NH4+.
文摘The authors assessed if wetlands can contribute to flood damage reduction in the Red River Basin, Minnesota, by providing reliable flood water storage. Hydrology and biodiversity in 28 natural and restored wetlands suggested uncontrolled natural wetlands provided the highest mean annual flood storage at 15 cm of runoff while single and 2-stage outlet controlled wetlands provided 3.0 and 8.1 cm of runoff control. Natural controlled wetlands, followed by 2-stage and single stage outlet controlled restorations provided 10.2, 6.6, and 2.2 cm of storage for early summer storm events. Two years of recorded water levels and a 20-year continuous meteorological record were used to model ＂temporary water level increases＂ in each wetland. Species diversity, hydrology, and watershed land use variables are inversely related where high quality and diverse wetlands had the lowest amplitude and frequency of water level increases, while low quality wetlands had the highest. Uncontrolled natural wetlands had the highest biological diversity and the lowest frequency and magnitude of temporary water levels increased. A significant biodiversity declines were measured where water level increases were greater than 2.7 meters. Strong multi-linear relationships between watershed land uses and watershed/wetland ratio explained wetland hydraulic performance and biodiversity relations （r2 ranging from 0.6-0.8）. Non-native wetland plant diversity increased with greater water level dynamics.
基金supported by the National Key R&D Program of China(2017YFA0206900)the National Natural Science Foundation of China(21625303)
文摘Biological ion channels show that ultrafast ions and molecules transmission are in a quantum way of single molecular or ionic chain with a certain number of molecules or ions, and we define it as ＂quantum-confined superfluid＂ （QSF）. This ordered ultrafast flow in the confined channel can be considered as ＂quantum tunneling fluid effect＂ with a ＂tunneling distance＂, which is corresponding to the period of QSF. Recent research demonstrated that artificial biomimetic nanochannels also showed the phenomenon of QSF, such as ion and water channels. The introduction of QSF concept in the fields of chemistry and biology may create significant impact. As for chemistry, the QSF effect provides new ideas for accurate synthesis in organic, inorganic, polymer, etc. We believe the implementation of the idea of QSF will promote the development of QSF biochemistry, biophysics, bioinformatics and biomedical science.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.41106072,41376093,41206064)Natural Science Foundation of Shandong(Grant No.ZR2010DM006)
文摘Concentrations of suspended particle material(SPM), dissolved silicate(DSi), biogenic silica(BSi), phytoliths(plant produced siliceous microscopic structures), and other parameters were analyzed to examine the influence of both natural processes and human activities on silica delivery to the estuary of the Huanghe River(Yellow River). Our results indicate that the concentrations of DSi in the river decreased significantly since 1986. Approximately 34% of dissolved silica was trapped in the basin between 1986 and 2010 due to a reduction of soil erosion. Phytoliths comprised 67.2%–96.3% of BSi, with the smoothing bar type being the dominant form. Concentrations of BSi are significantly higher in the Huanghe River compared to other major rivers throughout the world due to its high sediment yield. We also found that the ratios of BSi/(BSi+DSi) and BSi/SPM were approximately 0.5 and 0.003 at Lijin near the river mouth, indicating that BSi carried in suspension by the Huanghe River was an important component of the rivers silica load. Significant amounts of BSi were also composed of phytoliths in Bohai Sea sediments near the Huanghe River estuary with the smoothing bar form again being the most abundant. The relatively high specific fluxes of BSi in the Huanghe River reflect its high turbidity and high erosion rates in the basin. The high sediment load originating on the Loess Plateau is likely responsible for the higher BSi flux, in agreement with a general trend of increasing BSi flux with increasing sediment flux in global river systems. This study demonstrates that BSi transported by rivers can be composed largely of phytoliths originating from the erosion of topsoils. The flux of phytoliths in river's suspended sediment load may therefore represent a significant contribution to the biogeochemical cycle of silica in coastal waters.
基金supported by the Ministry of Science and Technology(2012AA022703,2012AA030608,2011CB933201 and 2009CB930001)the National Natural Science Foundation of China(31170905,21025520,51073045,31170905,GZ 614 and 91213305)+1 种基金the Chinese Academy of Sciences(KJCX2-YW-M15)the State Major Scientific and Technological Project of China(2013ZX09507005)
文摘Microfluidic technology provides opportunities to create in vitro models with physiological microenvironment for cell study.Introducing the identified key aspects,including tissue-tissue interfaces,spatiotemporal chemical gradients,and dynamic mechanical forces,of living organs into the microfluidic system,"organs-on-chips"display an unprecedented application potential in a lot of biological fields such as fundamental physiological and pathophysiological research,drug efficacy and toxicity testing,and clinical diagnosis.Here,we review the recent development of organs-on-chips and briefly discuss their future challenges.
