NiO_(x)as a hole transport material for inverted perovskite solar cells has received great attention owing to its high transparency,low fabrication temperature,and superior stability.However,the mismatched energy leve...NiO_(x)as a hole transport material for inverted perovskite solar cells has received great attention owing to its high transparency,low fabrication temperature,and superior stability.However,the mismatched energy levels and possible redox reactions at the NiO_(x)/perovskite interface severely limit the performance of NiO_(x) based inverted perovskite solar cells.Herein,we introduce a p-type self-assembled monolayer between NiO_(x)and perovskite layers to modify the interface and block the undesirable redox reaction between perovskite and NiO_(x)The selfassembled monolayer molecules all contain phosphoric acid function groups,which can be anchored onto the NiOr surface and passivate the surface defect.Moreover,the introduction of self-assembled monolayers can regulate the energy level structure of NiO_(x),reduce the interfacial band energy offset,and hence promote the hole transport from perovskite to NiO_(x)layer.Consequently,the device performance is significantly enhanced in terms of both power conversion efficiency and stability.展开更多
As by-products of petroleum refining,heavy oils are characterized by a high carbon content,low cost and great variability,making them competitive precursors for the anodes of potassium ion batteries(PIBs).However,the ...As by-products of petroleum refining,heavy oils are characterized by a high carbon content,low cost and great variability,making them competitive precursors for the anodes of potassium ion batteries(PIBs).However,the relationship between heavy oil composition and potassium storage performance remains unclear.Using heavy oils containing distinct chemical groups as the carbon source,namely fluid catalytic cracking slurry(FCCS),petroleum asphalt(PA)and deoiled asphalt(DOA),three carbon nanosheets(CNS)were prepared through a molten salt method,and used as the anodes for PIBs.The composition of the heavy oil determines the lamellar thicknesses,sp3-C/sp2-C ratio and defect concentration,thereby affecting the potassium storage performance.The high content of aromatic hydrocarbons and moderate amount of heavy component moieties in FCCS produce carbon nanosheets(CNS-FCCS)that have a smaller layer thickness,larger interlayer spacing(0.372 nm),and increased number of folds than in CNS derived from the other three precursors.These features give it faster charge/ion transfer,more potassium storage sites and better reaction kinetics.CNS-FCCS has a remarkable K^(+)storage capacity(248.7 mAh g^(-1) after 100 cycles at 0.1 A g^(-1)),long cycle lifespan(190.8 mAh g^(-1) after 800 cycles at 1.0 A g^(-1))and excellent rate capability,ranking it among the best materials for this application.This work sheds light on the influence of heavy oil composition on carbon structure and electrochemical performance,and provides guidance for the design and development of advanced heavy oil-derived carbon electrodes for PIBs.展开更多
The microstructure, phase composition and cold shut defect of thick titanium alloy electron beam welded joint were studied. The results showed that the microstructure of weld zone was composed of α′ phase; the heat ...The microstructure, phase composition and cold shut defect of thick titanium alloy electron beam welded joint were studied. The results showed that the microstructure of weld zone was composed of α′ phase; the heat affected zone was divided into fine-grained zone and coarse-grained zone, the microstructure of fine-grained zone was primary α phase + β phase + equiaxed α phase, and the microstructure of coarse-grained zone was primary α phase + acicular α′ phase; the microstructure of base metal zone basically consisted of primary α phase, and a small amount of residual β phase sprinkled. The forming. reason of cold shut was analyzed, and the precaution of cold shut was proposed.展开更多
Two kinds of cycloalkoxy silane compounds were synthesized and used as the internal electron donors (IEDs) of supported Ziegler-Natta catalyst for ethylene polymerization to produce polyethylene with broader molecul...Two kinds of cycloalkoxy silane compounds were synthesized and used as the internal electron donors (IEDs) of supported Ziegler-Natta catalyst for ethylene polymerization to produce polyethylene with broader molecular weight distribution (MWD), The effect of the structure and the amount of these IEDs on the polymerization performance was in- vestigated. The results implied that the molecular weight distribution of the obtained polyethylene could be adjusted by the incorporation of IEDs. SEM result showed that the morphology of catalyst particle was spherical and uniform in size distribution. The titanium content of these catalysts was higher, the active TiCl4 species were easily anchored on the support than that without adding IED, which was determined by ICE The GPC result confirmed that the polyethylene with broader molecular weight distribution in the range of from 23.4 to 25.6 was obtained using triethoxy-(-cyclopentyloxy)-silane (ED1) and triethoxy-(-cyclohexyloxyl)- silane (ED2) as the internal electron donors.展开更多
Coal and shale are both unconventional gas reservoirs. Comparison of pore characteristics in shale and coal would help understand organic pore structure in shale and investigate co-exploration of shale gas and coalbed...Coal and shale are both unconventional gas reservoirs. Comparison of pore characteristics in shale and coal would help understand organic pore structure in shale and investigate co-exploration of shale gas and coalbed methane in coal bearing strata. In this study, five shale samples and three coal samples of Taiyuan Formation were collected from Qinshui Basin, China. High pressure mercury injection, scanning electronic microscopy, and fractal theory have been used to compare pore characteristics in shale and coal. The results show that pore volumes in coal are much larger than that in shale, especially pores 3-100 nm. In coal, there are many semi-closed pores in micro pores (〈10 nm) and transition pores (10-100 nm). On the contrary, micro pores and transition pores are mainly with open pores in shale. The fractal curves show that pores larger than 65 nm in coal and shale reservoir both have obvious self-similarity and the fractal dimension values in shale and coal are similar. But the fractal characteristics of pores smaller than 65 nm in shale reservoir are quite different from that in coal.展开更多
We propose a two-component form to describe massive relativistic fermions in gauge theories. Relations between the Green's functions in this form and those in the conventional four-component form are derived. It is s...We propose a two-component form to describe massive relativistic fermions in gauge theories. Relations between the Green's functions in this form and those in the conventional four-component form are derived. It is shown that the S-matrix elements in both forms are exactly the same. The description of the fermion in the new form simplifies significantly the γ-matrix algebra in the four-component form. In particular, in perturbative calculations the propagator of the fermion is a scalar function. As examples, we use this form to reproduce the relativistic spectrum of hydrodron atom, the S-matrix of e+e-→μ+μ- and QED one-loop vacuum polarization of photon.展开更多
Indomethacin has been encapsulated with polyelectrolyte multilayers for controlled release. Gelatin and alginate were alternatively deposited on indomethacin microcrystals. The released amount of indomethacin from coa...Indomethacin has been encapsulated with polyelectrolyte multilayers for controlled release. Gelatin and alginate were alternatively deposited on indomethacin microcrystals. The released amount of indomethacin from coated microcrystals in pH6. 8 phosphate buffer solution (PBS) was measured with a UV spectrophometer. The polyelectrolyte multilayer capsule thickness was proved to control the release rate. The effects of osmotic pressure existed during the release process of indomethacin from microcapsules coated by (gelatin/alginate) 4.展开更多
Catalytic water splitting potentially reduce the consumption of fossil fuels and has received intense research attention.Synergy effects in multi‐element transition metal‐based water splitting catalysts have evoked ...Catalytic water splitting potentially reduce the consumption of fossil fuels and has received intense research attention.Synergy effects in multi‐element transition metal‐based water splitting catalysts have evoked special interests.Studies on catalysts in interfacial structures are especially meaningful due to their pertinence in applications.In this study,we report the synergy effects in promoting catalytic power in the ternary transition metal Zn,Co,Ni alloy nanoparticles that embeds in the carbonized Ppy/CNT multilayered matrix.By comparison with a series of binary or single metal counterparts,the mechanism under the synergy effects are elucidated.Experimental and DFT calculation results indicate that the ternary transition metal catalysts in the N‐doped carbon matrix present special electronic structure,which benefits the reversible transition‐state adsorption in HER and OER and render the catalysts high conductivity in room temperature.We expect our findings inspire further development of efficient transition metal HER and OER catalysts.展开更多
The book "micropedolog" by Kubieana and a large number of publications has induced many people to practice soil micromorphology. Quantification of the soil fabric and its components was a major challenge. The use of...The book "micropedolog" by Kubieana and a large number of publications has induced many people to practice soil micromorphology. Quantification of the soil fabric and its components was a major challenge. The use of the image analyses in soil science was a breakthrough. Attempts to make soil thin sections go back to the beginning of the 2oth century. Microscopic techniques and recently high resolution electron microscope and use of computer assisted imaging techniques enabled the in vitro study of soils in three dimensional levels. It is now possible to store and process massive amounts of data. Micro- morphological concepts and techniques are applied in paleopedological, ecological, and archaeological studies. The aim of this work was to examine soil micromorphological imaging in historical perspective.展开更多
Luvisols, Stagnogleys and Cambisols, although less fertile, are used intensively for mixed farming, grazing and as forestland. Therefore we aimed our study at determination of total organic carbon (TOC) content, hum...Luvisols, Stagnogleys and Cambisols, although less fertile, are used intensively for mixed farming, grazing and as forestland. Therefore we aimed our study at determination of total organic carbon (TOC) content, humic substances (HS) content, humic acids (HA) content, fulvic acids (FA), hot water extractable carbon (Chw) content and content total and labile trace elements content. Humic substances quality was assessed by HA/FA ratio and by coloured indexes measured in ultraviolet and visible UV-VIS spectral range. The total and labile contents of Zn, Cd, Cu, Co, Pb, Mo and Se were determined by flame or electro-thermal atomic absorption spectrometry after extraction of the soil samples in the aqua regia (total content) and in the solution of 0.01 M CaCI2. Total and labile trace elements content was correlated with determined carbon fractions and soil reaction. Results showed that studied soils content low amount of TOC and had low quality of humic substances. HA/FA ratio was less than 1 and colour indexes were higher than 4. All determined carbon fractions correlated with labile form of Zn and Cd. Correlation between soil reaction and total zinc content was found. Significant effect of humic substances content on to water-soluble forms of heavy metals was detected.展开更多
The strengths and weaknesses of different online technologies and learning methods have been examined by combining the blended learning program with practical work on institutional e-learning projects. There are diffe...The strengths and weaknesses of different online technologies and learning methods have been examined by combining the blended learning program with practical work on institutional e-learning projects. There are differences between the traditional e-learning system and the new E-Learning 2.0 training. At present time, the new technologies provided by Web 2.0 better correspond to the needs of both students and teaching staff. The new Web 2.0 allows the "promoting of individual creativity", together with the "use of collective intelligence". A comparison of the two development stages of the e-learning tools has been completed and the advantages of E-Learning 2.0 are shown. The main components of Web 2.0 are provided and the use ofwiki as an up-to-date collaboration tool for on-line teamwork is shown.展开更多
In order to increase the gross generation of wind turbines, the size of a tower and a rotor-nacelle becomes larger. In other words, the substructure for offshore wind turbines is strongly influenced by the effect of w...In order to increase the gross generation of wind turbines, the size of a tower and a rotor-nacelle becomes larger. In other words, the substructure for offshore wind turbines is strongly influenced by the effect of wave forces as the size of substructure increases. In addition, since a large offshore wind turbine has a heavy dead load, the reaction forces on the substructure become severe, thus very firm foundations should be required. Therefore, the dynamic soil-structure interaction has to be fully considered and the wave forces acting on substructure accurately calculated. In the present study, ANSYS AQWA is used to evaluate the wave forces. Moreover, the substructure method is applied to evaluate the effect of soil-structure interaction. Using the wave forces and the stiffness and damping matrices obtained from this study, the structural analysis of the gravity substructure is carried out through ANSYS mechanical. The structural behaviors of the strength and deformation are evaluated to investigate an ultimate structural safety and serviceability of gravity substructure for various soil conditions. Also, the modal analysis is carried out to investigate the resonance between the wind turbine and the gravity substructure.展开更多
The past five years have witnessed the discovery of the endoplasmic reticulum calcium(Ca2+) sensor STIM1 and the plasma membrane Ca2+channel Orai1 as the bona fide molecular components of the store-operated Ca2+ entry...The past five years have witnessed the discovery of the endoplasmic reticulum calcium(Ca2+) sensor STIM1 and the plasma membrane Ca2+channel Orai1 as the bona fide molecular components of the store-operated Ca2+ entry(SOCE) and the Ca2+ release-activated Ca2+current(I CRAC) .It has been known for two decades that SOCE and ICRAC are required for lymphocyte activation as evidenced by severe immunodeficient phenotypes in patients lacking ICRAC.In recent years however,studies have uncovered expression of STIM1 and Orai1 proteins in various tissues and described additional roles for these proteins in physiological functions and pathophysiological conditions.Here,we will summarize novel findings pertaining to the role of STIM1 and Orai1 in the vascular system and discuss their potential use as targets in the therapy of vascular disease.展开更多
Most biological photoredox reactions occur in sophisticated molecular assemblies consisting of highly organized light-harvesting moieties and catalytic centers.Mimicking these prototypes by creating supramolecular ass...Most biological photoredox reactions occur in sophisticated molecular assemblies consisting of highly organized light-harvesting moieties and catalytic centers.Mimicking these prototypes by creating supramolecular assemblies could be a potentially viable approach toward artificial photosynthesis.Although self-assembled organic materials are known to carry out water splitting reactions,developing self-assembled organic materials for photocatalytic overall water splitting still remains a critical challenge.Herein,we first demonstrate that crystalline organic nanosheets assembled from linear oligo(phenylene butadiynylene)(OPB)are able to catalyze overall water splitting under visible light irradiation.Further investigations reveal that the photocatalytic activity of self-assembled organic structures is closely related to the crystalline structure along with the corresponding electronic structure.Structural disorders in OPB nanosheets and extrinsic factors such as adsorbed water molecules will induce the formation of electron traps which can make the OPB nanosheets thermodynamically unfavorable for photocatalytic overall water splitting.The deactivation mechanism unveiled in this study provides crucial insights into the assembling of artificial organic materials for future solar-to-chemical energy conversion.展开更多
As the necessary components for various modern electronic and optoelectronic devices, novel transparent electrodes(TEs) with the low cost, abundance features, and comparable performance of indium tin oxide(ITO) are in...As the necessary components for various modern electronic and optoelectronic devices, novel transparent electrodes(TEs) with the low cost, abundance features, and comparable performance of indium tin oxide(ITO) are inquired materials. Metal nanowires(NWs) with the excellent photoelectric properties as next-generation TE candidates have widely applications in smart optoelectronic devices such as electronic skins, wearable electronics, robotic skins, flexible and stretchable displays. This review describes the synthetic strategies for the preparation of metal NWs, the assemble process for metal NW films,and the practical aspects of metal NW films with the desired properties in various low-cost, flexible,and solution-based photoelectric devices.展开更多
Novel dual-responsive superhydrophobic hybrid materials, ZnO/SAMs (self-assembled monolayers) of ionic liquids (ILs) with different counter-anions (I^-, BF4^-, PF6^- and Tf2N^-), were synthesized and characteriz...Novel dual-responsive superhydrophobic hybrid materials, ZnO/SAMs (self-assembled monolayers) of ionic liquids (ILs) with different counter-anions (I^-, BF4^-, PF6^- and Tf2N^-), were synthesized and characterized. ZnO nanoparticles were first deposited on glass surfaces to produce roughness. Next, SAMs of fluorinated-alkyl-3-(3-triethoxysilylpropyl)-4,5-dihydro-imidazoliumiodide (abb. [C8Ftespim]I) were grafted onto these surfaces via -Si-O- covalent bonds using self-assembly technique. The I- ion could be subsequently exchanged with BF4, PF6-or Tf2N- through a simple aqueous anion-exchange reaction. The ZnO/ILs hybrid layers were characterized by atomic-force microscopy (AFM), scanning-electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Their wettability was estimated through the measurements of static and dynamic contact angles (CAs). Compared to corresponding films of ZnO/[CsFtespim]I with CAs 140.7° ±2.0°, films of ZnO/[CsFtespim]PF6 and ZnO/[CsFtespim]Tf2N showed CAs with 154.0° ± 2.0° and 152.0° ± 2.0°, respectively that remained for a long time. This result suggests that anion-exchange can afford superhydrophobic materials. In addition, the wettability of ZnO/[CsFtespim]X hybrid layers can be reversibly switched by altering ultraviolet (UV) irradiation and dark storage, which shows a photo-induced reversible switch of wettability. The synergistic action of ZnO nanoparticles and SAMs of ILs produced light-anion dual-responsive superhydrophobic materials with ideal stability.展开更多
文摘NiO_(x)as a hole transport material for inverted perovskite solar cells has received great attention owing to its high transparency,low fabrication temperature,and superior stability.However,the mismatched energy levels and possible redox reactions at the NiO_(x)/perovskite interface severely limit the performance of NiO_(x) based inverted perovskite solar cells.Herein,we introduce a p-type self-assembled monolayer between NiO_(x)and perovskite layers to modify the interface and block the undesirable redox reaction between perovskite and NiO_(x)The selfassembled monolayer molecules all contain phosphoric acid function groups,which can be anchored onto the NiOr surface and passivate the surface defect.Moreover,the introduction of self-assembled monolayers can regulate the energy level structure of NiO_(x),reduce the interfacial band energy offset,and hence promote the hole transport from perovskite to NiO_(x)layer.Consequently,the device performance is significantly enhanced in terms of both power conversion efficiency and stability.
文摘As by-products of petroleum refining,heavy oils are characterized by a high carbon content,low cost and great variability,making them competitive precursors for the anodes of potassium ion batteries(PIBs).However,the relationship between heavy oil composition and potassium storage performance remains unclear.Using heavy oils containing distinct chemical groups as the carbon source,namely fluid catalytic cracking slurry(FCCS),petroleum asphalt(PA)and deoiled asphalt(DOA),three carbon nanosheets(CNS)were prepared through a molten salt method,and used as the anodes for PIBs.The composition of the heavy oil determines the lamellar thicknesses,sp3-C/sp2-C ratio and defect concentration,thereby affecting the potassium storage performance.The high content of aromatic hydrocarbons and moderate amount of heavy component moieties in FCCS produce carbon nanosheets(CNS-FCCS)that have a smaller layer thickness,larger interlayer spacing(0.372 nm),and increased number of folds than in CNS derived from the other three precursors.These features give it faster charge/ion transfer,more potassium storage sites and better reaction kinetics.CNS-FCCS has a remarkable K^(+)storage capacity(248.7 mAh g^(-1) after 100 cycles at 0.1 A g^(-1)),long cycle lifespan(190.8 mAh g^(-1) after 800 cycles at 1.0 A g^(-1))and excellent rate capability,ranking it among the best materials for this application.This work sheds light on the influence of heavy oil composition on carbon structure and electrochemical performance,and provides guidance for the design and development of advanced heavy oil-derived carbon electrodes for PIBs.
基金Project (2010CB731704) supported by the National Basic Research Program of China
文摘The microstructure, phase composition and cold shut defect of thick titanium alloy electron beam welded joint were studied. The results showed that the microstructure of weld zone was composed of α′ phase; the heat affected zone was divided into fine-grained zone and coarse-grained zone, the microstructure of fine-grained zone was primary α phase + β phase + equiaxed α phase, and the microstructure of coarse-grained zone was primary α phase + acicular α′ phase; the microstructure of base metal zone basically consisted of primary α phase, and a small amount of residual β phase sprinkled. The forming. reason of cold shut was analyzed, and the precaution of cold shut was proposed.
基金the National Natural Science Foundation of China(No.21174011)the Natural Science Foundation of Beijing,(No.2102036)the PetroChina Innovation Fund(Grant No.2011D-5006-0502)
文摘Two kinds of cycloalkoxy silane compounds were synthesized and used as the internal electron donors (IEDs) of supported Ziegler-Natta catalyst for ethylene polymerization to produce polyethylene with broader molecular weight distribution (MWD), The effect of the structure and the amount of these IEDs on the polymerization performance was in- vestigated. The results implied that the molecular weight distribution of the obtained polyethylene could be adjusted by the incorporation of IEDs. SEM result showed that the morphology of catalyst particle was spherical and uniform in size distribution. The titanium content of these catalysts was higher, the active TiCl4 species were easily anchored on the support than that without adding IED, which was determined by ICE The GPC result confirmed that the polyethylene with broader molecular weight distribution in the range of from 23.4 to 25.6 was obtained using triethoxy-(-cyclopentyloxy)-silane (ED1) and triethoxy-(-cyclohexyloxyl)- silane (ED2) as the internal electron donors.
基金The authors thank the National Science Foundation of China (41472135), the Research and Innovation Project for College Graduates of Jiangsu Province (KYLX15-1396), the Scientific Research Foundation of the Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process, Ministry of Education (China University of Mining and Technology) (No. 2015-04) for the support of the research.
文摘Coal and shale are both unconventional gas reservoirs. Comparison of pore characteristics in shale and coal would help understand organic pore structure in shale and investigate co-exploration of shale gas and coalbed methane in coal bearing strata. In this study, five shale samples and three coal samples of Taiyuan Formation were collected from Qinshui Basin, China. High pressure mercury injection, scanning electronic microscopy, and fractal theory have been used to compare pore characteristics in shale and coal. The results show that pore volumes in coal are much larger than that in shale, especially pores 3-100 nm. In coal, there are many semi-closed pores in micro pores (〈10 nm) and transition pores (10-100 nm). On the contrary, micro pores and transition pores are mainly with open pores in shale. The fractal curves show that pores larger than 65 nm in coal and shale reservoir both have obvious self-similarity and the fractal dimension values in shale and coal are similar. But the fractal characteristics of pores smaller than 65 nm in shale reservoir are quite different from that in coal.
基金Supported by National Natural Science Foundation of China under Grant No. 10475103
文摘We propose a two-component form to describe massive relativistic fermions in gauge theories. Relations between the Green's functions in this form and those in the conventional four-component form are derived. It is shown that the S-matrix elements in both forms are exactly the same. The description of the fermion in the new form simplifies significantly the γ-matrix algebra in the four-component form. In particular, in perturbative calculations the propagator of the fermion is a scalar function. As examples, we use this form to reproduce the relativistic spectrum of hydrodron atom, the S-matrix of e+e-→μ+μ- and QED one-loop vacuum polarization of photon.
基金The National Key Fundamental Research FundGrant number:9732003C8615700+1 种基金The National Natural Science Fund of ChinaGrant number:20376068
文摘Indomethacin has been encapsulated with polyelectrolyte multilayers for controlled release. Gelatin and alginate were alternatively deposited on indomethacin microcrystals. The released amount of indomethacin from coated microcrystals in pH6. 8 phosphate buffer solution (PBS) was measured with a UV spectrophometer. The polyelectrolyte multilayer capsule thickness was proved to control the release rate. The effects of osmotic pressure existed during the release process of indomethacin from microcapsules coated by (gelatin/alginate) 4.
文摘Catalytic water splitting potentially reduce the consumption of fossil fuels and has received intense research attention.Synergy effects in multi‐element transition metal‐based water splitting catalysts have evoked special interests.Studies on catalysts in interfacial structures are especially meaningful due to their pertinence in applications.In this study,we report the synergy effects in promoting catalytic power in the ternary transition metal Zn,Co,Ni alloy nanoparticles that embeds in the carbonized Ppy/CNT multilayered matrix.By comparison with a series of binary or single metal counterparts,the mechanism under the synergy effects are elucidated.Experimental and DFT calculation results indicate that the ternary transition metal catalysts in the N‐doped carbon matrix present special electronic structure,which benefits the reversible transition‐state adsorption in HER and OER and render the catalysts high conductivity in room temperature.We expect our findings inspire further development of efficient transition metal HER and OER catalysts.
文摘The book "micropedolog" by Kubieana and a large number of publications has induced many people to practice soil micromorphology. Quantification of the soil fabric and its components was a major challenge. The use of the image analyses in soil science was a breakthrough. Attempts to make soil thin sections go back to the beginning of the 2oth century. Microscopic techniques and recently high resolution electron microscope and use of computer assisted imaging techniques enabled the in vitro study of soils in three dimensional levels. It is now possible to store and process massive amounts of data. Micro- morphological concepts and techniques are applied in paleopedological, ecological, and archaeological studies. The aim of this work was to examine soil micromorphological imaging in historical perspective.
文摘Luvisols, Stagnogleys and Cambisols, although less fertile, are used intensively for mixed farming, grazing and as forestland. Therefore we aimed our study at determination of total organic carbon (TOC) content, humic substances (HS) content, humic acids (HA) content, fulvic acids (FA), hot water extractable carbon (Chw) content and content total and labile trace elements content. Humic substances quality was assessed by HA/FA ratio and by coloured indexes measured in ultraviolet and visible UV-VIS spectral range. The total and labile contents of Zn, Cd, Cu, Co, Pb, Mo and Se were determined by flame or electro-thermal atomic absorption spectrometry after extraction of the soil samples in the aqua regia (total content) and in the solution of 0.01 M CaCI2. Total and labile trace elements content was correlated with determined carbon fractions and soil reaction. Results showed that studied soils content low amount of TOC and had low quality of humic substances. HA/FA ratio was less than 1 and colour indexes were higher than 4. All determined carbon fractions correlated with labile form of Zn and Cd. Correlation between soil reaction and total zinc content was found. Significant effect of humic substances content on to water-soluble forms of heavy metals was detected.
文摘The strengths and weaknesses of different online technologies and learning methods have been examined by combining the blended learning program with practical work on institutional e-learning projects. There are differences between the traditional e-learning system and the new E-Learning 2.0 training. At present time, the new technologies provided by Web 2.0 better correspond to the needs of both students and teaching staff. The new Web 2.0 allows the "promoting of individual creativity", together with the "use of collective intelligence". A comparison of the two development stages of the e-learning tools has been completed and the advantages of E-Learning 2.0 are shown. The main components of Web 2.0 are provided and the use ofwiki as an up-to-date collaboration tool for on-line teamwork is shown.
文摘In order to increase the gross generation of wind turbines, the size of a tower and a rotor-nacelle becomes larger. In other words, the substructure for offshore wind turbines is strongly influenced by the effect of wave forces as the size of substructure increases. In addition, since a large offshore wind turbine has a heavy dead load, the reaction forces on the substructure become severe, thus very firm foundations should be required. Therefore, the dynamic soil-structure interaction has to be fully considered and the wave forces acting on substructure accurately calculated. In the present study, ANSYS AQWA is used to evaluate the wave forces. Moreover, the substructure method is applied to evaluate the effect of soil-structure interaction. Using the wave forces and the stiffness and damping matrices obtained from this study, the structural analysis of the gravity substructure is carried out through ANSYS mechanical. The structural behaviors of the strength and deformation are evaluated to investigate an ultimate structural safety and serviceability of gravity substructure for various soil conditions. Also, the modal analysis is carried out to investigate the resonance between the wind turbine and the gravity substructure.
基金supported by the National Institutes of Health(Grant No. 5R01HL097111)to Mohamed Trebak
文摘The past five years have witnessed the discovery of the endoplasmic reticulum calcium(Ca2+) sensor STIM1 and the plasma membrane Ca2+channel Orai1 as the bona fide molecular components of the store-operated Ca2+ entry(SOCE) and the Ca2+ release-activated Ca2+current(I CRAC) .It has been known for two decades that SOCE and ICRAC are required for lymphocyte activation as evidenced by severe immunodeficient phenotypes in patients lacking ICRAC.In recent years however,studies have uncovered expression of STIM1 and Orai1 proteins in various tissues and described additional roles for these proteins in physiological functions and pathophysiological conditions.Here,we will summarize novel findings pertaining to the role of STIM1 and Orai1 in the vascular system and discuss their potential use as targets in the therapy of vascular disease.
基金the National Key R&D Program of China(2017YFA0207301,2016YFA0200602,and 2018YFA0208702)the National Natural Science Foundation of China(21875235,21573211,and 21633007)+2 种基金the Anhui Initiative in Quantum Information Technologies(AHY090200)the China Postdoctoral Science Foundation(BX20200317)the Fundamental Research Funds for the Central Universities。
文摘Most biological photoredox reactions occur in sophisticated molecular assemblies consisting of highly organized light-harvesting moieties and catalytic centers.Mimicking these prototypes by creating supramolecular assemblies could be a potentially viable approach toward artificial photosynthesis.Although self-assembled organic materials are known to carry out water splitting reactions,developing self-assembled organic materials for photocatalytic overall water splitting still remains a critical challenge.Herein,we first demonstrate that crystalline organic nanosheets assembled from linear oligo(phenylene butadiynylene)(OPB)are able to catalyze overall water splitting under visible light irradiation.Further investigations reveal that the photocatalytic activity of self-assembled organic structures is closely related to the crystalline structure along with the corresponding electronic structure.Structural disorders in OPB nanosheets and extrinsic factors such as adsorbed water molecules will induce the formation of electron traps which can make the OPB nanosheets thermodynamically unfavorable for photocatalytic overall water splitting.The deactivation mechanism unveiled in this study provides crucial insights into the assembling of artificial organic materials for future solar-to-chemical energy conversion.
基金supported by the National Basic Research Program of China(2014CB931700)the Fundamental Research Funds for the Central Universities(30920130111017 and NE2012004)+1 种基金the Opened Fund of the State Key Laboratory on Integrated Optoelectronics(IOSKL2012KF06)the Program for Eastern Scholar at Shanghai Institutions of Higher Learning(2012-53)
文摘As the necessary components for various modern electronic and optoelectronic devices, novel transparent electrodes(TEs) with the low cost, abundance features, and comparable performance of indium tin oxide(ITO) are inquired materials. Metal nanowires(NWs) with the excellent photoelectric properties as next-generation TE candidates have widely applications in smart optoelectronic devices such as electronic skins, wearable electronics, robotic skins, flexible and stretchable displays. This review describes the synthetic strategies for the preparation of metal NWs, the assemble process for metal NW films,and the practical aspects of metal NW films with the desired properties in various low-cost, flexible,and solution-based photoelectric devices.
基金financially supported by the National Natural Science Foundation of China(21033005,21273134)the National Basic Research Program of China(2009CB930103)+2 种基金the Natural Science Foundation of Shandong Province(Combination Research Projects,ZR2013EML003&ZR2013BL001)National Undergraduate Training Programs for Innovation and Entrepreneurship(201310448008)Research Projects of Solar Energy of Dezhou University(311416&SYJS-B13003)
文摘Novel dual-responsive superhydrophobic hybrid materials, ZnO/SAMs (self-assembled monolayers) of ionic liquids (ILs) with different counter-anions (I^-, BF4^-, PF6^- and Tf2N^-), were synthesized and characterized. ZnO nanoparticles were first deposited on glass surfaces to produce roughness. Next, SAMs of fluorinated-alkyl-3-(3-triethoxysilylpropyl)-4,5-dihydro-imidazoliumiodide (abb. [C8Ftespim]I) were grafted onto these surfaces via -Si-O- covalent bonds using self-assembly technique. The I- ion could be subsequently exchanged with BF4, PF6-or Tf2N- through a simple aqueous anion-exchange reaction. The ZnO/ILs hybrid layers were characterized by atomic-force microscopy (AFM), scanning-electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Their wettability was estimated through the measurements of static and dynamic contact angles (CAs). Compared to corresponding films of ZnO/[CsFtespim]I with CAs 140.7° ±2.0°, films of ZnO/[CsFtespim]PF6 and ZnO/[CsFtespim]Tf2N showed CAs with 154.0° ± 2.0° and 152.0° ± 2.0°, respectively that remained for a long time. This result suggests that anion-exchange can afford superhydrophobic materials. In addition, the wettability of ZnO/[CsFtespim]X hybrid layers can be reversibly switched by altering ultraviolet (UV) irradiation and dark storage, which shows a photo-induced reversible switch of wettability. The synergistic action of ZnO nanoparticles and SAMs of ILs produced light-anion dual-responsive superhydrophobic materials with ideal stability.