Materials with low thermal conductivity are applied extensively in energy management,and breaking the amorphous limits of thermal conductivity to solids has attracted widespread attention from scientists.Doping is a c...Materials with low thermal conductivity are applied extensively in energy management,and breaking the amorphous limits of thermal conductivity to solids has attracted widespread attention from scientists.Doping is a common strategy for achieving low thermal conductivity that can offer abundant scattering centers in which heavier dopants always result in lower phonon group velocities and lower thermal conductivities.However,the amount of equivalent heavyatom single dopant available is limited.Unfortunately,nonequivalent heavy dopants have finite solubility because of charge imbalance.Here,we propose a charge balance strategy for SnS by substituting Sn2+with Ag^(+)and heavy Bi^(3+),improving the doping limit of Ag from 2%to 3%.Ag and Bi codoping increases the point defect concentration and introduces abundant boundaries simultaneously,scattering the phonons at both the atomic scale and nanoscale.The thermal conductivity of Ag0.03Bi0.03Sn0.94S decreased to 0.535 W·m^(−1)·K^(−1)at room temperature and 0.388 W·m^(−1)·K^(−1)at 275°C,which is below the amorphous limit of 0.450 W·m^(−1)·K^(−1)for SnS.This strategy offers a simple way to enhance the doping limit and achieve ultralow thermal conductivity in solids below the amorphous limit without precise structural modification.展开更多
The dynamic changes of land system in Huang - Huai - Hai Plain between 1988 and 2000 were researched in this paper. Spatial dominance econometric model was estabilished on 1 km cell to quantificafionally analyze the d...The dynamic changes of land system in Huang - Huai - Hai Plain between 1988 and 2000 were researched in this paper. Spatial dominance econometric model was estabilished on 1 km cell to quantificafionally analyze the driving-force for the dynamic change mechanism of land system, such as natural, social and economic factors. The future dynamic changes of land system in Huang - Huai - Hai Plain on each 1 km cell during 2000 to 2020 were stimulated by combining the dynamic changes of land system on each 1 km cell with different situations. The research indicated that the dynamic changes of land system structure changed mainly from the cultivated areas to building areas and industrial areas, and forest areas increased during this period. Although the revolutions of land system structure were different during 2000 to 2020 with the different referrence standard, ecological protection and economic development, the primary dynamic changes of land system structure were that the increase of building land areas with the decline cuhivaled land areas and the increase of woodlands.展开更多
[Objective] The paper aimed to evaluate the plain forestry' service function in Northwest China.[Method] Based on general and representative investigations with county used as the minimum unit,evaluation on service f...[Objective] The paper aimed to evaluate the plain forestry' service function in Northwest China.[Method] Based on general and representative investigations with county used as the minimum unit,evaluation on service function of plain forestry ecosystem in Northwest China was carried out by measuring the quality and quantity.[Result] In 2005,the plain forestry in Northwest China plays a profound role in water and soil conversation,carbon sequestration by vegetation and soil,oxygen release by plants,sulfur dioxide absorption and and so on.[Conclusion] This paper laid foundation for research on service function of plain forest ecosystem in Northwest China.展开更多
Metallothionein gene (MT) has been transferred into mushroom protoplasts by electroporation. It is a low molecular weight, cysteine-rich and metal-binding protein. MT can bind metals. Its synthesis is induced by Zn io...Metallothionein gene (MT) has been transferred into mushroom protoplasts by electroporation. It is a low molecular weight, cysteine-rich and metal-binding protein. MT can bind metals. Its synthesis is induced by Zn ion. Thus the expression of MT gene in mushroom can improve the accumulation of Zn in this fungus. This transgenic mushroom, consumed as a kind of vegetable, can supply the necessary Zn to people who are short of the element. When protoplasts were prepared, the concentration (C) of protoplasts is 6.745 x 10(6) /mL. After protoplast electroporation, the transformation rate of protoplasts is 0.01 %. Polymerase chain reaction (PCR) analysis showed that the gene had been integrated into the mushroom chromosome, SDS-PAGE, Western blot analysis indicated that the MT gene had been expressed in the transgenic mushroom. The expressing level, detected by ELISA, is 0.6 % - 0.8 %. Tested for metal resistance, the wild-type mushroom growth was inhibited on die medium containing 1.0 - 1.2 mmoL/L ZnSO4. While the transgenic mushroom was inhibited on the medium containing 1. 5 - 2.0 mmol/L ZnSO4. The mycelium can develop into hymenophore in the medium of rice bran: sawdust = 1: 3, and not in the medium of rice bran: sawdust = 1: 4.展开更多
[Objective] This study aimed to investigate the driving mechanism of eco- logical security in vulnerable areas in mountain and plain. [Method] The ecological security evaluation index system of Lincheng County was est...[Objective] This study aimed to investigate the driving mechanism of eco- logical security in vulnerable areas in mountain and plain. [Method] The ecological security evaluation index system of Lincheng County was established using PSR model. Driving mechanism was analyzed in total system and subsystems respectively by the principal components. The ecological safety driving factor was calculated through the total system and subsystem respectively. And the intersection was adopt- ed as dominant driving factor. [Result] A total of 10 indices including density index of rivers, land degradation index, farmland drought and flood insurance yield, human in- terference index, population density, the natural population growth rate, per capita GDP, the R&D funds spending accounts for the proportion of GDP, laborer by edu- cation degree and three industry accounted for the proportion of GDP, are the domi- nant driving factors of the regional ecological security. [Conclusion] This study will pro- vide reasonable and feasible advice for the benign development of the area.展开更多
[Objective] The aim was to explore the optimal density and nitrogen rate of no-tilling and direct sowing rapeseeds in Chengdu plain. [Methods] Effects of in- teraction between density and nitrogen rate on the growth a...[Objective] The aim was to explore the optimal density and nitrogen rate of no-tilling and direct sowing rapeseeds in Chengdu plain. [Methods] Effects of in- teraction between density and nitrogen rate on the growth and yield of direct sowing rapeseed under no-tillage condition were investigated with Chuanyou 58 as materials and a split-plot experiment adopted. [Results] In Chengdu Plain, the yields of rape- seed changed from increasing to decreasing with increase of density and nitrogen rate. Both of density and nitrogen rate had significant effects on growth and yield of rapeseed and the latter overweighed in the effect. In addition, interaction of the two had negative effects on rapeseed yield. The yield of rapeseeds achieved the highest at 3 395.25 kg/hm^2 with interaction of density at 30.00×10^4 plant/hm^2 and nitrogen rate at 180.00 kg/hm^2; the theoretical maximal yield was 3 403.41 kg/hm^2 with interaction of density at 40.80×10^4 plants/hm^2 and nitrogen rate at 198.90 kg/hm^2. [Conclusion] In Chengdu Plain, the optimal density and nitrogen rate are 30.00×10^4-45.00×10^4 plant/hm^2 and 180.00-198.90 kg/hm^2, respectively.展开更多
[Objective] The aim was to provide theoretical basis for the study of underground water dynamic changes in Songnen Plain in Jilin Province.[Method] The dynamic changes and driving factors for the underground water in ...[Objective] The aim was to provide theoretical basis for the study of underground water dynamic changes in Songnen Plain in Jilin Province.[Method] The dynamic changes and driving factors for the underground water in Songnen Plain in Jilin Province was expounded.[Result] Since 1960s,the temperature in the Songnen Plain in Jilin Province increased gradually.The average temperature increased 2℃;precipitation reduced gradually.Especially,the trend of precipitation reduction in west area was more distinct;in the meantime,the development of underground water augmented gradually and reached 2 800 million m3 in 2008.Driven by many factors,regional underground water level had distinct changes.Potential water position reduced greatly in northwest fan-shaped area.The one in other places were stable and even increased in certain parts;confined water position decreased quickly in general and it increased in certain parts.[Conclusion] The general deterioration trend of underground water environment was inevitable.But,the deterioration process can be eased through scientific planning and regional underground water resources so as to realize sustainable utilization of regional underground water resources.展开更多
With the support of the UNEP/GEF Siberian Crane Wetland Project,a five-year field survey of breeding waterbirds was conducted in four nature reserves - Zhalong,Keerqin,Xianghai and Momoge National Nature Reserves in t...With the support of the UNEP/GEF Siberian Crane Wetland Project,a five-year field survey of breeding waterbirds was conducted in four nature reserves - Zhalong,Keerqin,Xianghai and Momoge National Nature Reserves in the Songnen Plain for the period from May 2004 to August 2008.The purpose of the survey was to improve our understanding of the distribution and populations of breeding waterbirds in this area.The Red-crowned Crane (Grus japonensis) was the most important target species.Our survey results confirm that the Zhalong wetland is the largest breeding ground for the Red-crowned cranes in the Songnen Plain.Over 90% of the breeding birds were found in Zhalong,with numbers fluctuating from 112 to 275 over the years.Reed (Phragmites australis) is the most important plant species associated with breeding locations of this bird species.Water supply to the wetland can relieve pressure from deterioration of wetland habitats for the breeding of Red-crowned cranes.However,a sound scientific basis for the water supply mechanism is the key to better management of their habitat and a prerequisite for ensuring the breeding success of the Red-crowned Crane.展开更多
By utilizing phase field method combined with analysis on free energy and interatomic potentials, pre-precipitation phase formation and transformation process of Ni0.75Al0.05Fe0.2 alloy in early precipitation stage du...By utilizing phase field method combined with analysis on free energy and interatomic potentials, pre-precipitation phase formation and transformation process of Ni0.75Al0.05Fe0.2 alloy in early precipitation stage during the ageing process under 1 000 K were studied. And free energy, microstructures, compositions and volume fractions of pre-precipitation phase and equilibrium phase were analyzed. The simulation results indicate that nonstoichiometric Llo pre-precipitation phase formed first, and then would gradually transform into L12 equilibrium phase. It is discovered that the phase transformation process was closely related to free energy and interatomic potentials. Additionally, it is revealed that free energy of Llo pre-precipitation phase was higher and interatomic potential was smaller than that of L12 equilibrium phase. Therefore, it is concluded that Llo phase was unstable, and phase transformation would occur to L12 which was more stable.展开更多
Based on spatial climatic data of agriculture and the experiment data, the models of agro-ecological assessment of climate for agricultural suitability in this study were developed using the fuzzy mathematical method....Based on spatial climatic data of agriculture and the experiment data, the models of agro-ecological assessment of climate for agricultural suitability in this study were developed using the fuzzy mathematical method. Three coefficients, in- cluding the resource coefficient (Cr), the efficiency coefficient (Ce), and the utility co- efficient (K), were used in the models, which were calculated based on temperature, moisture, and sunshine duration data of Guanzhong region, Shaanxi Province. The results indicated that resource coefficient was higher in west of the region than that in east, and higher in south (especially in the Central Shaanxi Plain) than that in the Weibei plateau. The value of Cr changed from 6.5 to 9.2 from north to plain area. Spatial change of efficiency coefficient was obvious, lower in the northeast than in the central plain, and the value of Ce changed from 2.3 to 6.5 from the northeast to the central plain. As for utility coefficient, it was lower in northeastern part of the Weibei plateau and in southern mountain areas than that in the central plain, showing significant latitudinal zonality. Furthermore, the value of K increased from 0.35 to 0.78 from northeast to the central plain, and decreased from 0.78 to 0.53 from the central plain to southern mountain areas. These indicated that climate resource in the central plain region was more abundant and potential, compared with other regions. GuanZhong region was classified into three larger agricultural zones and three small independent zones, according to agro-ecological assessment. Light, heat and water resources should be made use of in an efficient way in spatial allo- cation of agricultural production. For example, water facilities should also be im- proved in Weibei plateau region where highly-qualified fruit should be enhanced and fruit processing industrial chain should be shaped. Large-scale production area of wheat should be increased in central irrigation region and more vegetable bases should be developed around large and medium-scale cities. Thanks for outstanding water conservation function, the three-dimensional agriculture including medicine and other sideline production should be developed in Qinling Mountains and the special- ized commercial agriculture should be accelerated in independent small zones, ac- cording to local conditions. In the research, different crop varieties were developed in corresponding regions as per current eco-climatic conditions.展开更多
s: The farmland shelterbelts in Northeastern Plain of China have formed relatively complete net system. The func-tions of shelterbelt net in omnibearing wind check and prevention of frostbite as well as the field of ...s: The farmland shelterbelts in Northeastern Plain of China have formed relatively complete net system. The func-tions of shelterbelt net in omnibearing wind check and prevention of frostbite as well as the field of integrated climate effect within shelterbelt net were analyzed, through located observation of meteorological factors. Within the shelterbelt net, the area with more than 10% efficiency of omnibearing wind check was determined as benefited area. The analysis of yield and quality of crops indicated that the sheltering range of shelterbelt net was 25 times tree height. The mature heights of the various varieties of poplar composed the shelterbelts were determined according to their height growth. Based on the comprehensive analysis above, the suitable size of farmland shelterbelt net in Northeastern Plain of China was decided to be 400 m×400 m.展开更多
Based on the geochemical data obtained from the national project about the prevention and control of soil contamination, this paper explored the properties of soil chemical elements in Huanghuaihai Plain, Shandong Pro...Based on the geochemical data obtained from the national project about the prevention and control of soil contamination, this paper explored the properties of soil chemical elements in Huanghuaihai Plain, Shandong Province. The results showed that among the grade-one nutritive elements in soil, organic matter, nitrogen and phosphorus were relatively deficient while potassium was rich. Meanwhile, as the grade-two nutritive elements, calcium oxide and magnesium oxide were relatively short and sulfur’s content was abundant. About the other beneficial and trace nutri-tive elements, iron oxide, manganese, molybdenum and boron were deficient, but the content of chlorine was high, hardly lack. The main barriers to improving land productivity were soil salinization and soil heavy metal contamination. The values of soil integrated fertility index that most of the soil in the study area is middle-lower fertilized. Specifical y, the low fertility area and lower fertility area are 6 1604 and 1 244 km2 respectively, occupying about 97.43% and 1.97% of the total area. The moderate fertility soil has an area of 172 km2, occupying about 0.27% of the total area. The higher fertility soil covers an area of 128 km2, while the high fertility area of only 76 km2. This article proposed scientific fertilization, elimination of soil obsta-cle, remediation of heavy-metal-contaminated soil and other effective measures to improve land productivity according to the basic investigation results, which provides a good technological support for the planning and development of good-quality and high-benefit agriculture.展开更多
In order to measure the impact of changes in the marsh on breeding Red-crowned Cranes (Grus japonensis) and White-naped Cranes (G.vipio) in the Sanjiang Plain,we conducted a complete crane súrvey in each of the s...In order to measure the impact of changes in the marsh on breeding Red-crowned Cranes (Grus japonensis) and White-naped Cranes (G.vipio) in the Sanjiang Plain,we conducted a complete crane súrvey in each of the summers of 2007 and 2008,and obtained information on the changes in its marsh through interpretation of satellite images in 1986,1995,2000 and 2005.A comparison between the 1984 and 2008 census shows that:1) the number of Red-crowned Cranes remained stable at about 300 birds,while the number of White-naped Cranes increased markedly; 2) the estimates of nests of Red-crowned cranes are close to the numbers of 1984,while approximately 90% of the nests of these two crane species were distributed over five national nature reserves (NNRs); 3) the two crane species became more concentrated in three regions,i.e.,the Fuyuan Delta,the middle reaches of the Naoli and Qixing rivers,and the Xingkai Lake wetlands,rather as formerly in six regions.The area of the marsh decreased by 45% within the 20-year period from 1986 to 2005.The major loss of the marsh area was in the form of a conversion to paddy fields and dry land,which can be primarily attributed to direct human activity under various economic and policy drivers.The disappearance of cranes in the Dulu and Abuqin rivers was induced by large-scale agricultural development.The fragmentation into and isolation of small areas of the marsh became increasingly more serious,which resulted in unsuitable condtions for crane breeding in small patches of the marsh.The number of cranes declined from 1984-1995 but had recovered remarkably by 2008,which may be due to theestablishment of a system of nature reserves,in place since 2000.The land ownership of the reserve plays a key role in maintaining the integrity of the wetland ecosystem,especially in Sanjiang,Honghe,Naolihe and Qixinghe NNRs,which together accommodated approximately 80% of the population of cranes.However,we did not discover any nests at all in the provincial and municipal reserves,which may be attributed to high human disturbances in these areas.In the end,we propose some recommendations on reserve management.展开更多
基金supported by the CAS Project for Young Scientists in Basic Research(YSBR-070)the National Natural Science Foundation of China(21925110,21890750,U2032161,12147105)+8 种基金the USTC Research Funds of the Double First-Class Initiative(YD2060002004)the National Key Research and Development Program of China(2022YFA1203600,2022YFA1203601,2022YFA1203602)the Natural Science Foundation of China-Anhui Joint Fund(U23A20121)the Outstanding Youth Foundation of Anhui Province(2208085J14)the Anhui Provincial Key Research and Development Project(202004a050200760)the Key R&D Program of Shandong Province(2021CXGC010302)the Users with Excellence Project of Hefei Science Center CAS(2021HSC-UE004)the Fellowship of the China Postdoctoral Science Foundation(2022M710141)the open foundation of the Key Laboratory of the Engineering Research Center of Building Energy Efficiency Control and Evaluation,Ministry of Education(AHJZNX-2023-04).
文摘Materials with low thermal conductivity are applied extensively in energy management,and breaking the amorphous limits of thermal conductivity to solids has attracted widespread attention from scientists.Doping is a common strategy for achieving low thermal conductivity that can offer abundant scattering centers in which heavier dopants always result in lower phonon group velocities and lower thermal conductivities.However,the amount of equivalent heavyatom single dopant available is limited.Unfortunately,nonequivalent heavy dopants have finite solubility because of charge imbalance.Here,we propose a charge balance strategy for SnS by substituting Sn2+with Ag^(+)and heavy Bi^(3+),improving the doping limit of Ag from 2%to 3%.Ag and Bi codoping increases the point defect concentration and introduces abundant boundaries simultaneously,scattering the phonons at both the atomic scale and nanoscale.The thermal conductivity of Ag0.03Bi0.03Sn0.94S decreased to 0.535 W·m^(−1)·K^(−1)at room temperature and 0.388 W·m^(−1)·K^(−1)at 275°C,which is below the amorphous limit of 0.450 W·m^(−1)·K^(−1)for SnS.This strategy offers a simple way to enhance the doping limit and achieve ultralow thermal conductivity in solids below the amorphous limit without precise structural modification.
基金Supported by the National Natural Science Foundation of China(70503025)the Knowledge Innovation Project of Chinese Academy of Sci-ences(KZCX2-YW-305-2+3 种基金KSCX2-YW-N-039)the National Project of Scientific and Technical Supporting Programs(2006BAC08B032006BAC08B06)international cooperation program of science and technolo-gy ministry(2006DFB919201).~~
文摘The dynamic changes of land system in Huang - Huai - Hai Plain between 1988 and 2000 were researched in this paper. Spatial dominance econometric model was estabilished on 1 km cell to quantificafionally analyze the driving-force for the dynamic change mechanism of land system, such as natural, social and economic factors. The future dynamic changes of land system in Huang - Huai - Hai Plain on each 1 km cell during 2000 to 2020 were stimulated by combining the dynamic changes of land system on each 1 km cell with different situations. The research indicated that the dynamic changes of land system structure changed mainly from the cultivated areas to building areas and industrial areas, and forest areas increased during this period. Although the revolutions of land system structure were different during 2000 to 2020 with the different referrence standard, ecological protection and economic development, the primary dynamic changes of land system structure were that the increase of building land areas with the decline cuhivaled land areas and the increase of woodlands.
文摘[Objective] The paper aimed to evaluate the plain forestry' service function in Northwest China.[Method] Based on general and representative investigations with county used as the minimum unit,evaluation on service function of plain forestry ecosystem in Northwest China was carried out by measuring the quality and quantity.[Result] In 2005,the plain forestry in Northwest China plays a profound role in water and soil conversation,carbon sequestration by vegetation and soil,oxygen release by plants,sulfur dioxide absorption and and so on.[Conclusion] This paper laid foundation for research on service function of plain forest ecosystem in Northwest China.
文摘Metallothionein gene (MT) has been transferred into mushroom protoplasts by electroporation. It is a low molecular weight, cysteine-rich and metal-binding protein. MT can bind metals. Its synthesis is induced by Zn ion. Thus the expression of MT gene in mushroom can improve the accumulation of Zn in this fungus. This transgenic mushroom, consumed as a kind of vegetable, can supply the necessary Zn to people who are short of the element. When protoplasts were prepared, the concentration (C) of protoplasts is 6.745 x 10(6) /mL. After protoplast electroporation, the transformation rate of protoplasts is 0.01 %. Polymerase chain reaction (PCR) analysis showed that the gene had been integrated into the mushroom chromosome, SDS-PAGE, Western blot analysis indicated that the MT gene had been expressed in the transgenic mushroom. The expressing level, detected by ELISA, is 0.6 % - 0.8 %. Tested for metal resistance, the wild-type mushroom growth was inhibited on die medium containing 1.0 - 1.2 mmoL/L ZnSO4. While the transgenic mushroom was inhibited on the medium containing 1. 5 - 2.0 mmol/L ZnSO4. The mycelium can develop into hymenophore in the medium of rice bran: sawdust = 1: 3, and not in the medium of rice bran: sawdust = 1: 4.
基金Supported by Hebei Provincial Natural Science Fund for Youth (D2010001566)Projects of Hebei Academy of Science and Technology (12116, 13140)Hebei Key Technology Research and Development Program (11237126D)~~
文摘[Objective] This study aimed to investigate the driving mechanism of eco- logical security in vulnerable areas in mountain and plain. [Method] The ecological security evaluation index system of Lincheng County was established using PSR model. Driving mechanism was analyzed in total system and subsystems respectively by the principal components. The ecological safety driving factor was calculated through the total system and subsystem respectively. And the intersection was adopt- ed as dominant driving factor. [Result] A total of 10 indices including density index of rivers, land degradation index, farmland drought and flood insurance yield, human in- terference index, population density, the natural population growth rate, per capita GDP, the R&D funds spending accounts for the proportion of GDP, laborer by edu- cation degree and three industry accounted for the proportion of GDP, are the domi- nant driving factors of the regional ecological security. [Conclusion] This study will pro- vide reasonable and feasible advice for the benign development of the area.
基金Supported by National Science and Technology Support Program(2010BAD01B08)Sichuan Finance Gene Engineering Program(2011JYGC04-013)12th Five Year Breeding Project of Crops of Sichuan Province~~
文摘[Objective] The aim was to explore the optimal density and nitrogen rate of no-tilling and direct sowing rapeseeds in Chengdu plain. [Methods] Effects of in- teraction between density and nitrogen rate on the growth and yield of direct sowing rapeseed under no-tillage condition were investigated with Chuanyou 58 as materials and a split-plot experiment adopted. [Results] In Chengdu Plain, the yields of rape- seed changed from increasing to decreasing with increase of density and nitrogen rate. Both of density and nitrogen rate had significant effects on growth and yield of rapeseed and the latter overweighed in the effect. In addition, interaction of the two had negative effects on rapeseed yield. The yield of rapeseeds achieved the highest at 3 395.25 kg/hm^2 with interaction of density at 30.00×10^4 plant/hm^2 and nitrogen rate at 180.00 kg/hm^2; the theoretical maximal yield was 3 403.41 kg/hm^2 with interaction of density at 40.80×10^4 plants/hm^2 and nitrogen rate at 198.90 kg/hm^2. [Conclusion] In Chengdu Plain, the optimal density and nitrogen rate are 30.00×10^4-45.00×10^4 plant/hm^2 and 180.00-198.90 kg/hm^2, respectively.
基金Supported by Chinese Geographic Investigation Bureau Financial Support Project(1212010813093)~~
文摘[Objective] The aim was to provide theoretical basis for the study of underground water dynamic changes in Songnen Plain in Jilin Province.[Method] The dynamic changes and driving factors for the underground water in Songnen Plain in Jilin Province was expounded.[Result] Since 1960s,the temperature in the Songnen Plain in Jilin Province increased gradually.The average temperature increased 2℃;precipitation reduced gradually.Especially,the trend of precipitation reduction in west area was more distinct;in the meantime,the development of underground water augmented gradually and reached 2 800 million m3 in 2008.Driven by many factors,regional underground water level had distinct changes.Potential water position reduced greatly in northwest fan-shaped area.The one in other places were stable and even increased in certain parts;confined water position decreased quickly in general and it increased in certain parts.[Conclusion] The general deterioration trend of underground water environment was inevitable.But,the deterioration process can be eased through scientific planning and regional underground water resources so as to realize sustainable utilization of regional underground water resources.
基金supported by the GEF Siberian Crane Wetland Project(UNEP DGEF C/F2712-03 GF-6030-03)the International Crane Foundation(ICF)
文摘With the support of the UNEP/GEF Siberian Crane Wetland Project,a five-year field survey of breeding waterbirds was conducted in four nature reserves - Zhalong,Keerqin,Xianghai and Momoge National Nature Reserves in the Songnen Plain for the period from May 2004 to August 2008.The purpose of the survey was to improve our understanding of the distribution and populations of breeding waterbirds in this area.The Red-crowned Crane (Grus japonensis) was the most important target species.Our survey results confirm that the Zhalong wetland is the largest breeding ground for the Red-crowned cranes in the Songnen Plain.Over 90% of the breeding birds were found in Zhalong,with numbers fluctuating from 112 to 275 over the years.Reed (Phragmites australis) is the most important plant species associated with breeding locations of this bird species.Water supply to the wetland can relieve pressure from deterioration of wetland habitats for the breeding of Red-crowned cranes.However,a sound scientific basis for the water supply mechanism is the key to better management of their habitat and a prerequisite for ensuring the breeding success of the Red-crowned Crane.
基金Projects(10902086, 50941020, 50875217) supported by the National Natural Science Foundation of China Projects(JC201005) supported by Basic Research Fund of Northwestern Polytechnical University, China Project supported by Graduate Starting Seed Fund and Doctoral Foundation of Northwestern Polytechnical University, China
文摘By utilizing phase field method combined with analysis on free energy and interatomic potentials, pre-precipitation phase formation and transformation process of Ni0.75Al0.05Fe0.2 alloy in early precipitation stage during the ageing process under 1 000 K were studied. And free energy, microstructures, compositions and volume fractions of pre-precipitation phase and equilibrium phase were analyzed. The simulation results indicate that nonstoichiometric Llo pre-precipitation phase formed first, and then would gradually transform into L12 equilibrium phase. It is discovered that the phase transformation process was closely related to free energy and interatomic potentials. Additionally, it is revealed that free energy of Llo pre-precipitation phase was higher and interatomic potential was smaller than that of L12 equilibrium phase. Therefore, it is concluded that Llo phase was unstable, and phase transformation would occur to L12 which was more stable.
基金National Natural Science Foundation of China(4113074841101162+2 种基金4100137441101165)Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-YW-QN304)~~
文摘Based on spatial climatic data of agriculture and the experiment data, the models of agro-ecological assessment of climate for agricultural suitability in this study were developed using the fuzzy mathematical method. Three coefficients, in- cluding the resource coefficient (Cr), the efficiency coefficient (Ce), and the utility co- efficient (K), were used in the models, which were calculated based on temperature, moisture, and sunshine duration data of Guanzhong region, Shaanxi Province. The results indicated that resource coefficient was higher in west of the region than that in east, and higher in south (especially in the Central Shaanxi Plain) than that in the Weibei plateau. The value of Cr changed from 6.5 to 9.2 from north to plain area. Spatial change of efficiency coefficient was obvious, lower in the northeast than in the central plain, and the value of Ce changed from 2.3 to 6.5 from the northeast to the central plain. As for utility coefficient, it was lower in northeastern part of the Weibei plateau and in southern mountain areas than that in the central plain, showing significant latitudinal zonality. Furthermore, the value of K increased from 0.35 to 0.78 from northeast to the central plain, and decreased from 0.78 to 0.53 from the central plain to southern mountain areas. These indicated that climate resource in the central plain region was more abundant and potential, compared with other regions. GuanZhong region was classified into three larger agricultural zones and three small independent zones, according to agro-ecological assessment. Light, heat and water resources should be made use of in an efficient way in spatial allo- cation of agricultural production. For example, water facilities should also be im- proved in Weibei plateau region where highly-qualified fruit should be enhanced and fruit processing industrial chain should be shaped. Large-scale production area of wheat should be increased in central irrigation region and more vegetable bases should be developed around large and medium-scale cities. Thanks for outstanding water conservation function, the three-dimensional agriculture including medicine and other sideline production should be developed in Qinling Mountains and the special- ized commercial agriculture should be accelerated in independent small zones, ac- cording to local conditions. In the research, different crop varieties were developed in corresponding regions as per current eco-climatic conditions.
文摘s: The farmland shelterbelts in Northeastern Plain of China have formed relatively complete net system. The func-tions of shelterbelt net in omnibearing wind check and prevention of frostbite as well as the field of integrated climate effect within shelterbelt net were analyzed, through located observation of meteorological factors. Within the shelterbelt net, the area with more than 10% efficiency of omnibearing wind check was determined as benefited area. The analysis of yield and quality of crops indicated that the sheltering range of shelterbelt net was 25 times tree height. The mature heights of the various varieties of poplar composed the shelterbelts were determined according to their height growth. Based on the comprehensive analysis above, the suitable size of farmland shelterbelt net in Northeastern Plain of China was decided to be 400 m×400 m.
基金Supported by Multi-goal Geochemical Survey in Laoling-Hekou Regions,Shandong Province of National Soil Survey and Pollution Prevention(GZTR20060104)~~
文摘Based on the geochemical data obtained from the national project about the prevention and control of soil contamination, this paper explored the properties of soil chemical elements in Huanghuaihai Plain, Shandong Province. The results showed that among the grade-one nutritive elements in soil, organic matter, nitrogen and phosphorus were relatively deficient while potassium was rich. Meanwhile, as the grade-two nutritive elements, calcium oxide and magnesium oxide were relatively short and sulfur’s content was abundant. About the other beneficial and trace nutri-tive elements, iron oxide, manganese, molybdenum and boron were deficient, but the content of chlorine was high, hardly lack. The main barriers to improving land productivity were soil salinization and soil heavy metal contamination. The values of soil integrated fertility index that most of the soil in the study area is middle-lower fertilized. Specifical y, the low fertility area and lower fertility area are 6 1604 and 1 244 km2 respectively, occupying about 97.43% and 1.97% of the total area. The moderate fertility soil has an area of 172 km2, occupying about 0.27% of the total area. The higher fertility soil covers an area of 128 km2, while the high fertility area of only 76 km2. This article proposed scientific fertilization, elimination of soil obsta-cle, remediation of heavy-metal-contaminated soil and other effective measures to improve land productivity according to the basic investigation results, which provides a good technological support for the planning and development of good-quality and high-benefit agriculture.
基金supported by the Conservation Fund of the State Forestry Administration of China and the Siberian Crane Wetland GEF/UNEP Project(GF/2712-03-4627)
文摘In order to measure the impact of changes in the marsh on breeding Red-crowned Cranes (Grus japonensis) and White-naped Cranes (G.vipio) in the Sanjiang Plain,we conducted a complete crane súrvey in each of the summers of 2007 and 2008,and obtained information on the changes in its marsh through interpretation of satellite images in 1986,1995,2000 and 2005.A comparison between the 1984 and 2008 census shows that:1) the number of Red-crowned Cranes remained stable at about 300 birds,while the number of White-naped Cranes increased markedly; 2) the estimates of nests of Red-crowned cranes are close to the numbers of 1984,while approximately 90% of the nests of these two crane species were distributed over five national nature reserves (NNRs); 3) the two crane species became more concentrated in three regions,i.e.,the Fuyuan Delta,the middle reaches of the Naoli and Qixing rivers,and the Xingkai Lake wetlands,rather as formerly in six regions.The area of the marsh decreased by 45% within the 20-year period from 1986 to 2005.The major loss of the marsh area was in the form of a conversion to paddy fields and dry land,which can be primarily attributed to direct human activity under various economic and policy drivers.The disappearance of cranes in the Dulu and Abuqin rivers was induced by large-scale agricultural development.The fragmentation into and isolation of small areas of the marsh became increasingly more serious,which resulted in unsuitable condtions for crane breeding in small patches of the marsh.The number of cranes declined from 1984-1995 but had recovered remarkably by 2008,which may be due to theestablishment of a system of nature reserves,in place since 2000.The land ownership of the reserve plays a key role in maintaining the integrity of the wetland ecosystem,especially in Sanjiang,Honghe,Naolihe and Qixinghe NNRs,which together accommodated approximately 80% of the population of cranes.However,we did not discover any nests at all in the provincial and municipal reserves,which may be attributed to high human disturbances in these areas.In the end,we propose some recommendations on reserve management.