Two sets of dehydration-melting with a natural solid amphibolite, collected from North Himalayan structure zone, Tibet, have been carried out in multi-anvil apparatus at 2.0 GPa and 800―1000℃, for 12―200 h. One is ...Two sets of dehydration-melting with a natural solid amphibolite, collected from North Himalayan structure zone, Tibet, have been carried out in multi-anvil apparatus at 2.0 GPa and 800―1000℃, for 12―200 h. One is keeping the pressure at 2.0 GPa and the annealing time of 12 h, changing the temperature (800―1000℃). The other is keeping the pressure at 2.0 GPa and temperature at 850℃, varying the annealing time (12―200 h). The products are inspected with microscope and electron probe. The results indicate that at 2.0 GPa, annealing time of 12 h, garnets, melts and clinopyroxenes occur in amphibolite gradually with increasing temperature and the chemical compositions of melt vary from tonalite to granodiorite, and then to tonalite. However, at 2.0 GPa and 850℃, with the annealing time increasing, the garnets, melts and cli-nopyroxenes also occur in amphibolite gradually and the chemical compositions of melt vary from tonalite to granodiorite. In both cases, melts interconnect with each other when the contents of melt are over the 5 vol.%. the viscosities of the melt produced in amphibolite at temperature higher than 850℃ are on a level with 104 Pa·s. The interconnected melt with such a viscosity may segregate from the source rock and form the magma over reasonable geological time. Therefore, it is believed that at the lower part of the overthickened crust, the tonlitic and grano-dioritic magma may be generated through the dehydration melting of amphibolite.展开更多
Recently we are witnessing the boom of high-pressure science and technology from a small niche field to becoming a major dimension in physical sciences.One of the most important technological advances is the integrati...Recently we are witnessing the boom of high-pressure science and technology from a small niche field to becoming a major dimension in physical sciences.One of the most important technological advances is the integration of synchrotron nanotechnology with the minute samples at ultrahigh pressures.Applications of high pressure have greatly enhanced our understanding of the electronic,phonon,and doping effects on the newly emerged graphene and related 2D layered materials.High pressure has created exotic stoichiometry even in common Group 17,15,and 14 compounds and drastically altered the basic σ and π bonding of organic compounds.Differential pressure measurements enable us to study the rheology and flow of mantle minerals in solid state,thus quantitatively constraining the geodynamics.They also introduce a new approach to understand defect and plastic deformations of nano particles.These examples open new frontiers of high-pressure research.展开更多
Zirconium-based metal-organic frameworks(Zr-MOFs)have attracted widespread attention due to their high specific surface area,high porosity,abundant metal active sites and excellent hydrothermal stability.However,Zr-MO...Zirconium-based metal-organic frameworks(Zr-MOFs)have attracted widespread attention due to their high specific surface area,high porosity,abundant metal active sites and excellent hydrothermal stability.However,Zr-MOFs materials are mostly powdery in nature and thus difficult to separate from aqueous media,which limits their application in wastewater treatment.In this study,PDA/Zr-MOFs/PU foam was constructed by growing Zr-MOFs nanoparticles on a dopamine-modified polyurethane foam substrate by in-situ hydrothermal synthesis as an adsorbent for removing dyes from wastewater.The results demonstrated that the polydopamine coating improves the dispersion of the Zr-MOFs nanoparticles on the substrate and enhances the interaction between the Zr-MOFs nanoparticles and the PU foam substrate.As a result,compared with Zr-MOFs/PU foam,the prepared PDA/ZrMOFs/PU foam exhibits higher adsorption capacity for crystal violet(CV)(63.38 mg/g)and rhodamine B(RB)(67.73 mg/g),with maximum adsorption efficiencies of CV and RB of 98.4%(pH=11)and 93.5%(pH=7),respectively,at a concentration of 10 mg/L.The PDA/Zr-MOFs/PU foam can simultaneously remove CV and RB from the mixed solution.Moreover,the PDA/ZrMOFs/PU foam still exhibits high stability and reusability after five cycles.展开更多
Porous carbon skeletons(PCSs)derived from isocyanate-based aromatic polyimide foams(PIFs)by high-temperature pyrolysis are very promising in the fabrication of high-performance polymer composite foams for electromagne...Porous carbon skeletons(PCSs)derived from isocyanate-based aromatic polyimide foams(PIFs)by high-temperature pyrolysis are very promising in the fabrication of high-performance polymer composite foams for electromagnetic interference(EMI)shielding due to their efficient conductive networks and facile preparation process.However,severe volumetric shrinkage and low graphitization degree is not conducive to enhancing the shielding efficiency of the PCSs.Herein,ferric acetylacetonate and carbon-nanotube coating have been introduced in isocyanate-based PIFs to greatly suppress the serious shrinkage during pyrolysis and improve the graphitization degree of the final carbon foams through the Fe-catalytic graphitization process,thereby endowing them with better EMI-shielding performance even at lower pyrolysis temperature compared to the control samples.Moreover,compressible polydimethylsiloxane(PDMS)composite foams with the as-prepared carbon foams as prefabricated PCSs have also been fabricated,which could provide not only stable shielding effectiveness(SE)performance even after a thousand compressions,but also multiple functions of Joule heating,thermal insulation and infrared stealth.This study offers a feasible route to prepare high-performance PCSs in a more energy-efficient manner via PIF pyrolysis,which is very promising in the manufacture of multifunctional conductive polymer composite foams.展开更多
Nowadays,carbon frameworks derived from natural biomaterials have attracted extensive attention for electromagnetic interference(EMI)shielding due to their renewability and affordability.However,it is critical and cha...Nowadays,carbon frameworks derived from natural biomaterials have attracted extensive attention for electromagnetic interference(EMI)shielding due to their renewability and affordability.However,it is critical and challenging to achieve effective regulation of shielding effectiveness(SE)as well as weaken the strong EM reflection of highly conductive biomass-based carbon materials.Herein,commercial cotton pads with oriented structure were selected as carbonaceous precursor to fabricate aligned carbon networks by pyrolysis,and the EMI SE of the samples with increased temperature of 800-1000℃ can be accurately controlled in the effective range of~21.7-29.1,~27.7-37.1 and~32.7-43.3 d B with high reflection coefficient of>0.8 by changing the cross-angle between the electric-field direction of incident EM waves and the fiber-orientation direction due to the occurrence of opposite internal electric field.Moreover,the further construction of Salisbury absorber-liked double-layer structure could result in an ultralow reflection coefficient of only~0.06 but enhanced SE variation range up to~38.7-49.3 d B during the adjustment of cross-angle,possibly due to the destructive interference of EM waves in the double-layer carbon networks.This work would provide a simple and effective way for constructing high-performance biomass carbon materials with adjustable EMI shielding and ultra-low reflectivity.展开更多
Since President U Thein Sein took office in March, 2011, Naypyidaw has put forward bold reforms, including democratization, ethnic reconciliation and economic liberalisation. These measures resulted in a stable societ...Since President U Thein Sein took office in March, 2011, Naypyidaw has put forward bold reforms, including democratization, ethnic reconciliation and economic liberalisation. These measures resulted in a stable society as well as steady and fast economic growth in the country. Meanwhile, the improving investment environment in Myanmar has boosted Foreign Direct Investment （FDI）. To implement its ＂Go Out＂ policy, China is now encouraging domestic enterprises to participate in overseas infrastructure construction, energy industries and industrial cooperation. Therefore, an analysis of the investment conditions in Myanmar will be very helpful in facilitating investment cooperation between China and Myanmar.展开更多
Under artificially simulated conditions, the water purification effects of Lythrum salicaria, Typha minima, Scirpus validus, Iris wilsonii and their configurations were studied. The results showed that various aquatic...Under artificially simulated conditions, the water purification effects of Lythrum salicaria, Typha minima, Scirpus validus, Iris wilsonii and their configurations were studied. The results showed that various aquatic plants and their configurations showed purification effects for total nitrogen(TN), nitrate nitrogen(NO_3^-), total phosphorus(TP), orthophosphate(PO_4^(3-)) and chemical oxygen demand(COD) in water body, and the purification effects of aquatic plant configurations were better than those of single ones. Regression analysis was conducted for dynamics of various water quality indicators. The removal rates of TN and COD within 50 d by the combination of L. salicaria and I. wilsonii were 73.83% and 77.4%, respectively, with the best purification effect; the removal rate of NO_3^- within 20 d by the combination of S. validus and I. wilsonii was 89.41%; and the combination of S. validus and I. wilsonii showed the best removal effect for TP and PO43-, of which the 50-d removal rates were 88.98% and 92.39%, respectively. Reasonable choice of local aquatic plants and their optimal combinations can be applied in the improvement of water quality of rivers.展开更多
The China’s Conversion Cropland to Forest Program(CCFP)is one of the largest national ecological construction programs,which has effectively improved ecological environment and produced large ecological benefi t.To p...The China’s Conversion Cropland to Forest Program(CCFP)is one of the largest national ecological construction programs,which has effectively improved ecological environment and produced large ecological benefi t.To provide references for further improving ecological benefi t of CCFP,we analyzed the features,differences and relationships of the categorized forest ecological“benefi t value”(B-V)s in 3 kinds of forest restoration ways in different regions in CCFP,using the data of Chinese Forest Ecosystem Research Network(CFERN)from 1999 to 2013 and the methods of the national standards of(LY/T1606-2003),(LY/T1721-2008)and(LY/T1952-2011).The result showed that annual B-Vs of unit area varied in the range of 3.5-10.0 e4 RMBs/hm2·a.Water conservation B-Vs and species conservation B-Vs are the 2 largest constituents,nutrient accumulation B-V was the least in total B-Vs.The B-Vs performed inconsistently among the forest restoration ways and different regions.The rank of average annual total B-Vs of unit area from high to low was“hillside forest conservation”,“returning cropland to forest”,“afforestation on suitable barren hills and wasteland”.Species conservation B-Vs and water conservation B-Vs in southern regions were higher than that of northern and northwestern regions in China.The hot and rainy regions could produce higher species conservation B-Vs.The regression analysis indicated that water conservation B-Vs had signifi cantly positive correlation with the relevant total B-Vs and positive correlation with the relevant atmosphere purification B-Vs whether in regional or in unit area scale.Unit area species conservation B-V was negatively correlated with the relevant nutrient accumulation B-Vs except the way of“afforestation on suitable barren hills and wasteland”.Regional total species conservation B-Vs had signifi cantly negative correlation with its relevant nutrient accumulation B-Vs except“hillside forest conservation”way.We suggest that suitable forest restoration ways must be selec展开更多
The paper introduces the basic environmental pollution situation of China and points out that environmental pollution is bottleneck of China＇s economy development. Then it puts forward the main environmental pollutio...The paper introduces the basic environmental pollution situation of China and points out that environmental pollution is bottleneck of China＇s economy development. Then it puts forward the main environmental pollution problems of China. At last, it brings forward the countermeasures to environmental pollution.展开更多
Based on the extensive analysis of natural and social conditions,regional development,and characteristics of tree species in the Beijing-Tianjin corridor,a comprehensive evaluation index system that consists of A,B,C,...Based on the extensive analysis of natural and social conditions,regional development,and characteristics of tree species in the Beijing-Tianjin corridor,a comprehensive evaluation index system that consists of A,B,C,D layers was established for introduced tree species.Nine local representative introduced tree species were evaluated using the analytic hierarchy process(AHP).The results showed that Platanus orientalis,Quercus mongolicus,and Zizyphusjujube performed better comprehensively and were recommended as the dominant introduced tree species in the Beijing-Tianjin corridor.Other representative introduced tree species should be appropriately developed in the region.Main factors that should be taken into account for introduced tree species including drought tolerance,wintering habit,growth rate,leanness tolerance,pollution tolerance,saline tolerance,and disease resistance.展开更多
基金the National Natural Science Foumndation of China(Grant Nos.10299040 , 40103 003) the Knowleige Innovation Program of the Chinese Acacemy of Sciences(Gant No.RJCX2-SW-No.3).
文摘Two sets of dehydration-melting with a natural solid amphibolite, collected from North Himalayan structure zone, Tibet, have been carried out in multi-anvil apparatus at 2.0 GPa and 800―1000℃, for 12―200 h. One is keeping the pressure at 2.0 GPa and the annealing time of 12 h, changing the temperature (800―1000℃). The other is keeping the pressure at 2.0 GPa and temperature at 850℃, varying the annealing time (12―200 h). The products are inspected with microscope and electron probe. The results indicate that at 2.0 GPa, annealing time of 12 h, garnets, melts and clinopyroxenes occur in amphibolite gradually with increasing temperature and the chemical compositions of melt vary from tonalite to granodiorite, and then to tonalite. However, at 2.0 GPa and 850℃, with the annealing time increasing, the garnets, melts and cli-nopyroxenes also occur in amphibolite gradually and the chemical compositions of melt vary from tonalite to granodiorite. In both cases, melts interconnect with each other when the contents of melt are over the 5 vol.%. the viscosities of the melt produced in amphibolite at temperature higher than 850℃ are on a level with 104 Pa·s. The interconnected melt with such a viscosity may segregate from the source rock and form the magma over reasonable geological time. Therefore, it is believed that at the lower part of the overthickened crust, the tonlitic and grano-dioritic magma may be generated through the dehydration melting of amphibolite.
文摘Recently we are witnessing the boom of high-pressure science and technology from a small niche field to becoming a major dimension in physical sciences.One of the most important technological advances is the integration of synchrotron nanotechnology with the minute samples at ultrahigh pressures.Applications of high pressure have greatly enhanced our understanding of the electronic,phonon,and doping effects on the newly emerged graphene and related 2D layered materials.High pressure has created exotic stoichiometry even in common Group 17,15,and 14 compounds and drastically altered the basic σ and π bonding of organic compounds.Differential pressure measurements enable us to study the rheology and flow of mantle minerals in solid state,thus quantitatively constraining the geodynamics.They also introduce a new approach to understand defect and plastic deformations of nano particles.These examples open new frontiers of high-pressure research.
基金supported by the National Natural Science Foundation of China(No.51703234)the China Postdoctoral Science Foundation(No.2018M632438)+3 种基金the Zhejiang Provincial Natural Science Foundation of China(No.LY17E030010)the Natural Science Foundation of Ningbo City of China(Nos.2018A610036,2018A610219,2018A610029,2019A610159,and 2019A610005)the Scientific Research Fund of Zhejiang Provincial Education Department(No.Y201839180)the K.C.Wong Magna Fund in Ningbo University。
文摘Zirconium-based metal-organic frameworks(Zr-MOFs)have attracted widespread attention due to their high specific surface area,high porosity,abundant metal active sites and excellent hydrothermal stability.However,Zr-MOFs materials are mostly powdery in nature and thus difficult to separate from aqueous media,which limits their application in wastewater treatment.In this study,PDA/Zr-MOFs/PU foam was constructed by growing Zr-MOFs nanoparticles on a dopamine-modified polyurethane foam substrate by in-situ hydrothermal synthesis as an adsorbent for removing dyes from wastewater.The results demonstrated that the polydopamine coating improves the dispersion of the Zr-MOFs nanoparticles on the substrate and enhances the interaction between the Zr-MOFs nanoparticles and the PU foam substrate.As a result,compared with Zr-MOFs/PU foam,the prepared PDA/ZrMOFs/PU foam exhibits higher adsorption capacity for crystal violet(CV)(63.38 mg/g)and rhodamine B(RB)(67.73 mg/g),with maximum adsorption efficiencies of CV and RB of 98.4%(pH=11)and 93.5%(pH=7),respectively,at a concentration of 10 mg/L.The PDA/Zr-MOFs/PU foam can simultaneously remove CV and RB from the mixed solution.Moreover,the PDA/ZrMOFs/PU foam still exhibits high stability and reusability after five cycles.
基金Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2022300)Natural Science Foundation of Ningbo(No.202003N4026)China Postdoctoral Science Foundation(No.2020M682375)’Key Scientific Research Projects of Colleges and Universities in Henan Province(No.21A430025).
文摘Porous carbon skeletons(PCSs)derived from isocyanate-based aromatic polyimide foams(PIFs)by high-temperature pyrolysis are very promising in the fabrication of high-performance polymer composite foams for electromagnetic interference(EMI)shielding due to their efficient conductive networks and facile preparation process.However,severe volumetric shrinkage and low graphitization degree is not conducive to enhancing the shielding efficiency of the PCSs.Herein,ferric acetylacetonate and carbon-nanotube coating have been introduced in isocyanate-based PIFs to greatly suppress the serious shrinkage during pyrolysis and improve the graphitization degree of the final carbon foams through the Fe-catalytic graphitization process,thereby endowing them with better EMI-shielding performance even at lower pyrolysis temperature compared to the control samples.Moreover,compressible polydimethylsiloxane(PDMS)composite foams with the as-prepared carbon foams as prefabricated PCSs have also been fabricated,which could provide not only stable shielding effectiveness(SE)performance even after a thousand compressions,but also multiple functions of Joule heating,thermal insulation and infrared stealth.This study offers a feasible route to prepare high-performance PCSs in a more energy-efficient manner via PIF pyrolysis,which is very promising in the manufacture of multifunctional conductive polymer composite foams.
基金financial supports from Natural Science Foundation of Ningbo(202003N4026)S&T Innovation 2025 Major Special Programme of Ningbo(2018B10054)National Natural Science Foundation of China(62001065 and 51603218)。
文摘Nowadays,carbon frameworks derived from natural biomaterials have attracted extensive attention for electromagnetic interference(EMI)shielding due to their renewability and affordability.However,it is critical and challenging to achieve effective regulation of shielding effectiveness(SE)as well as weaken the strong EM reflection of highly conductive biomass-based carbon materials.Herein,commercial cotton pads with oriented structure were selected as carbonaceous precursor to fabricate aligned carbon networks by pyrolysis,and the EMI SE of the samples with increased temperature of 800-1000℃ can be accurately controlled in the effective range of~21.7-29.1,~27.7-37.1 and~32.7-43.3 d B with high reflection coefficient of>0.8 by changing the cross-angle between the electric-field direction of incident EM waves and the fiber-orientation direction due to the occurrence of opposite internal electric field.Moreover,the further construction of Salisbury absorber-liked double-layer structure could result in an ultralow reflection coefficient of only~0.06 but enhanced SE variation range up to~38.7-49.3 d B during the adjustment of cross-angle,possibly due to the destructive interference of EM waves in the double-layer carbon networks.This work would provide a simple and effective way for constructing high-performance biomass carbon materials with adjustable EMI shielding and ultra-low reflectivity.
文摘Since President U Thein Sein took office in March, 2011, Naypyidaw has put forward bold reforms, including democratization, ethnic reconciliation and economic liberalisation. These measures resulted in a stable society as well as steady and fast economic growth in the country. Meanwhile, the improving investment environment in Myanmar has boosted Foreign Direct Investment （FDI）. To implement its ＂Go Out＂ policy, China is now encouraging domestic enterprises to participate in overseas infrastructure construction, energy industries and industrial cooperation. Therefore, an analysis of the investment conditions in Myanmar will be very helpful in facilitating investment cooperation between China and Myanmar.
基金Sponsored by Key Technology Research and Development Program of Hebei Province(15227652D)Dynamic Control Technology of Sandy Land Protection Forest System Structure in Northern North China(2016YFC0500802-06)
文摘Under artificially simulated conditions, the water purification effects of Lythrum salicaria, Typha minima, Scirpus validus, Iris wilsonii and their configurations were studied. The results showed that various aquatic plants and their configurations showed purification effects for total nitrogen(TN), nitrate nitrogen(NO_3^-), total phosphorus(TP), orthophosphate(PO_4^(3-)) and chemical oxygen demand(COD) in water body, and the purification effects of aquatic plant configurations were better than those of single ones. Regression analysis was conducted for dynamics of various water quality indicators. The removal rates of TN and COD within 50 d by the combination of L. salicaria and I. wilsonii were 73.83% and 77.4%, respectively, with the best purification effect; the removal rate of NO_3^- within 20 d by the combination of S. validus and I. wilsonii was 89.41%; and the combination of S. validus and I. wilsonii showed the best removal effect for TP and PO43-, of which the 50-d removal rates were 88.98% and 92.39%, respectively. Reasonable choice of local aquatic plants and their optimal combinations can be applied in the improvement of water quality of rivers.
基金Hebei Provincial Science&Technology Supporting Program(No.15227652D)Guided by Observation Methodology for Long-term Forest Ecosystem Research of National Standards of the People’s Republic of China(GB/T 33027-2016).
文摘The China’s Conversion Cropland to Forest Program(CCFP)is one of the largest national ecological construction programs,which has effectively improved ecological environment and produced large ecological benefi t.To provide references for further improving ecological benefi t of CCFP,we analyzed the features,differences and relationships of the categorized forest ecological“benefi t value”(B-V)s in 3 kinds of forest restoration ways in different regions in CCFP,using the data of Chinese Forest Ecosystem Research Network(CFERN)from 1999 to 2013 and the methods of the national standards of(LY/T1606-2003),(LY/T1721-2008)and(LY/T1952-2011).The result showed that annual B-Vs of unit area varied in the range of 3.5-10.0 e4 RMBs/hm2·a.Water conservation B-Vs and species conservation B-Vs are the 2 largest constituents,nutrient accumulation B-V was the least in total B-Vs.The B-Vs performed inconsistently among the forest restoration ways and different regions.The rank of average annual total B-Vs of unit area from high to low was“hillside forest conservation”,“returning cropland to forest”,“afforestation on suitable barren hills and wasteland”.Species conservation B-Vs and water conservation B-Vs in southern regions were higher than that of northern and northwestern regions in China.The hot and rainy regions could produce higher species conservation B-Vs.The regression analysis indicated that water conservation B-Vs had signifi cantly positive correlation with the relevant total B-Vs and positive correlation with the relevant atmosphere purification B-Vs whether in regional or in unit area scale.Unit area species conservation B-V was negatively correlated with the relevant nutrient accumulation B-Vs except the way of“afforestation on suitable barren hills and wasteland”.Regional total species conservation B-Vs had signifi cantly negative correlation with its relevant nutrient accumulation B-Vs except“hillside forest conservation”way.We suggest that suitable forest restoration ways must be selec
文摘The paper introduces the basic environmental pollution situation of China and points out that environmental pollution is bottleneck of China＇s economy development. Then it puts forward the main environmental pollution problems of China. At last, it brings forward the countermeasures to environmental pollution.
文摘Based on the extensive analysis of natural and social conditions,regional development,and characteristics of tree species in the Beijing-Tianjin corridor,a comprehensive evaluation index system that consists of A,B,C,D layers was established for introduced tree species.Nine local representative introduced tree species were evaluated using the analytic hierarchy process(AHP).The results showed that Platanus orientalis,Quercus mongolicus,and Zizyphusjujube performed better comprehensively and were recommended as the dominant introduced tree species in the Beijing-Tianjin corridor.Other representative introduced tree species should be appropriately developed in the region.Main factors that should be taken into account for introduced tree species including drought tolerance,wintering habit,growth rate,leanness tolerance,pollution tolerance,saline tolerance,and disease resistance.
