Permanent ferrite magnet materials are extensively employed due to their exceptional magnetic properties and cost-effectiveness.The fast development in electromobile and household appliance industries contributes to a...Permanent ferrite magnet materials are extensively employed due to their exceptional magnetic properties and cost-effectiveness.The fast development in electromobile and household appliance industries contributes to a new progress in permanent ferrite materials.This paper reviews the deveolpement and progress of permanent ferrite magnet industry in recent years.The emergence of new raw material,the advancement of perparation methods and manufacturing techniques,and the potential applications of permanent ferrite materials are introduced and discussed.Specifically,nanocrystallization plays a crucial role in achieving high performance at a low cost and reducing reliance on rare earth resources,and therefore it could be a promising development trendency.展开更多
Herein,we employ the threshold energy neutron analysis(TENA)technique to introduce the world's first active interrogation system to detect special nuclear materials(SNMs),including U-235 and Pu-239.The system util...Herein,we employ the threshold energy neutron analysis(TENA)technique to introduce the world's first active interrogation system to detect special nuclear materials(SNMs),including U-235 and Pu-239.The system utilizes a DD neutron generator based on inertial electrostatic confinement(IEC)to interrogate suspicious objects.To detect secondary neutrons produced during fission reactions induced in SNMs,a tensioned metastable fluid detector(TMFD)is employed.The current status of the system's development is reported in this paper,accompanied by the results from experiments conducted to detect 10 g of highly enriched uranium(HEU).Notably,the experimental findings demonstrate a distinct difference in the count rates of measurements with and without HEU.This difference in count rates surpasses two times the standard deviation,indicating a confidence level of more than 96% for identifying the presence of HEU.The paper presents and extensively discusses the proof-of-principle experimental results,along with the system's planned trajectory.展开更多
The smuggling of special nuclear materials(SNMs)across national borders is becoming a serious threat to nuclear nonproliferation.This paper presents a feasibility study on the rapid interrogation of concealed SNMs by ...The smuggling of special nuclear materials(SNMs)across national borders is becoming a serious threat to nuclear nonproliferation.This paper presents a feasibility study on the rapid interrogation of concealed SNMs by combining scattering and transmission nuclear resonance fluorescence(s NRF and t NRF)spectroscopy.In s NRF spectroscopy,SNMs such as^(235,238)U are excited by a wide-band photon beam of appropriate energy and exhibit unique NRF signatures.Monte Carlo simulations show that one-dimensional scans can realize isotopic identification of concealed^(235,238)U when the detector array used for interrogation has sufficiently high energy resolution.The simulated isotopic ratio^(235U/238)U is in good agreement with the theoretical value when the SNMs are enclosed in relatively thin iron.This interrogation is followed by t NRF spectroscopy using a narrow-band photon beam with the goal of obtaining tomographic images of the concealed SNMs.The reconstructed image clearly reveals the position of the isotope^(235)U inside an iron rod.It is shown that the interrogation time of s NRF and t NRF spectroscopy is one order of magnitude lower than that when only t NRF spectroscopy is used and results in a missed-detection rate of 10^(-3).The proposed method can also be applied for isotopic imaging of other SNMs such as^(239,240)Pu and^(237)Np.展开更多
Various novel carbonaceous materials including carbon nanotubes,nano-onions,carbon microspheres,graphene nanosheets,and carbon microfibers with unique properties,such as tunable surface area and pore size,high chemica...Various novel carbonaceous materials including carbon nanotubes,nano-onions,carbon microspheres,graphene nanosheets,and carbon microfibers with unique properties,such as tunable surface area and pore size,high chemical stability,cost-effective and facile preparation,have attracted enormous interest for many applications.Also essential,the activation processes play a critical role to achieve these valuable properties.In this review,we provide a thorough analysis of the emerging nano-and microscopic carbon species with special morphology/textures and currently available types of chemical activation agents,and novel activation strategy to enhance electrochemical performance of activated carbon material in electrical energy storage devices including supercapacitor and alkaline ions batteries.A particular emphasis is set on recent advance in activated carbon materials with special morphology/textures for supercapacitors and sodium ion batteries.展开更多
Since the Third Plenary Session of the 11 thCentral Committee of the Communist Party of China( CPC),with the promotion and development of traditional Chinese medicine(TCM),the pace of TCM nursing work has been acceler...Since the Third Plenary Session of the 11 thCentral Committee of the Communist Party of China( CPC),with the promotion and development of traditional Chinese medicine(TCM),the pace of TCM nursing work has been accelerated in nationwide,and a group of integrated Chinese and western medicine nurses have been cultivated preliminarily. However,professional nurses of integrated Chinese and western medicine are still deficient extremely. The target of talent cultivation,based on the theory of "focusing on humanism,expanding diathesis,and enhancing practice to highlight the accommodation and integration of nurses of integrated traditional Chinese and western medicine",is to cultivate competent,practical and interdisciplinary senior nursing talents with strong professional basis,skilled operations,rich humanistic literacy,and sharp innovative spirit who not only master modern nursing knowledge and skills,but also can perform comprehensive nursing under the guidance of TCM theory of holistic concept and syndrome differentiation and nursing. This study,through investigating and analyzing the settings of3-year nursing professional courses in about 20 senior medical colleges,including senior nursing education of TCM,reformed the development of professional nursing courses of integrated Chinese and western medicine and the establishment of educational materials according to the course settings and educational work modes,so as to analyze the current status of nursing education of integrated Chinese and western medicine,determine course targets,and establish course system and educational work modes.展开更多
The thermal protection materials and structures are widely used in hypersonic vehicles for the purpose of thermal insulation, and their mechanical behavior is one of the key issues in design and manufacture of hyperso...The thermal protection materials and structures are widely used in hypersonic vehicles for the purpose of thermal insulation, and their mechanical behavior is one of the key issues in design and manufacture of hypersonic vehicles. It is our great pleasure to present the seven papers in this special subject of Theoretical & Applied Mechanics Letters (TAML) and introduce the recent progresses on the mechanical behavior of thermal protection materials and structures by the authors.展开更多
Halide perovskite,a novel semiconductor material,was initially used in solar cells since 2009,and tremendous progresses have been witnessed in the last decade.The power conversion efficiency of the single perovskite s...Halide perovskite,a novel semiconductor material,was initially used in solar cells since 2009,and tremendous progresses have been witnessed in the last decade.The power conversion efficiency of the single perovskite solar cells has been incredibly increased up to 25.2%,and close to 30%efficiency was realized in perovskite/silicon tandem solar cells.Recently,the application of perovskite has been extended to the light-emitting diodes and photo-detectors.展开更多
In recent years,the Ministry of Agriculture has increased input in agricultural scientific research projects.As a result,the procurement amount and quantity of special materials are increasing gradually,and the manage...In recent years,the Ministry of Agriculture has increased input in agricultural scientific research projects.As a result,the procurement amount and quantity of special materials are increasing gradually,and the management of special materials becomes more standardized.In order to do well in management of special materials,the authors made exploration and thinking about further strengthening management of special materials in combination with actual conditions,including establishing regulations and systems,enhancing procurement process,strengthening requisition and safekeeping,and reinforcing general ledger management of special materials.展开更多
Chinese top planner-State Development and Reform Commission,has decided to organize and coordinate an implementation of a special project for high tech industrialization of fiber-reinforced compound materials in 2008 ...Chinese top planner-State Development and Reform Commission,has decided to organize and coordinate an implementation of a special project for high tech industrialization of fiber-reinforced compound materials in 2008 up to 2009.The decision has recently been issued in its national circular(doc. 3177,Yr.2007)to call for local enterprises to apply for this special project support.展开更多
Lying between radio frequency and infrared radiation, terahertz (THz) wave encounters lots of difficulties to produce, detect, transmit, and modulate. Great efforts have been made to construct THz devices, including...Lying between radio frequency and infrared radiation, terahertz (THz) wave encounters lots of difficulties to produce, detect, transmit, and modulate. Great efforts have been made to construct THz devices, including sources, detectors, switches, modulators, lenses, and filters. However, only moderate progresses have been made in THz generation and detection. Furthermore, the devices and techniques to control and manipulate THz waves are still in its infancy. Therefore, it is still a challenge to date to develop sophisticated THz application systems such as communication, sensing, safety inspection, imaging and medical diagnose systems. This difficult position of THz wave is essential due to the deficiency of THz materials having a suitable THz electromagnetic response, as compared to its neighboring microwave and infrared regime. Practicable material will largely push the THz technology to real-world applications. The GaAs/AlxGa~_xAs material system, for example, is the heart of THz quantum cascade lasers. High quality NbN films, again, set the basis of THz hot electron bolometer.展开更多
Graphene, a single layer of graphite, has been one of the first real two dimensional (2D) materials isolated in 2004. Thus, graphene is becoming a cutting edge material that opens up new horizons to a whole family o...Graphene, a single layer of graphite, has been one of the first real two dimensional (2D) materials isolated in 2004. Thus, graphene is becoming a cutting edge material that opens up new horizons to a whole family of 2D materials beyond the limited current applicability of graphene. The unique advantages of graphene and analogue 2D materials, such as atomic-scale thickness, high specific surface area, mechanically flexible robustness, superior storage capacity, endow them as high-performance electrodes lbr electrochemical energy storage devices. Although it is hard to say whether or not graphene and 2D materials will be implemented in future energy technologies, the recent achievements in this field demonstrate that their roles will be noticeable in the near future.展开更多
A new way for the synthesis of human interferon—α_A monoclonal antibody (IFN-α_A-McAb) bound to silica gel packing material in high-performance affinity chromatography (HPAFC) has been developed. The high coupling ...A new way for the synthesis of human interferon—α_A monoclonal antibody (IFN-α_A-McAb) bound to silica gel packing material in high-performance affinity chromatography (HPAFC) has been developed. The high coupling efficiency and specific activity of IFN—α_A-McAb can be obtained by activated diol-silica gel with activating agent. After purification using this packing material in HPAFC, the specific activity of recombinant human interferon-α_A (rIFN-α_A) rose up to 1.03×10~7IU/mg protein and the purification efficiency is appoximately 100 times.展开更多
The rising cost and limited availability of fossil fuels, and the increasing concerns related to their role on global pollution and greenhouse effect have pushed considerably the need to accelerate the transition to a...The rising cost and limited availability of fossil fuels, and the increasing concerns related to their role on global pollution and greenhouse effect have pushed considerably the need to accelerate the transition to a more sustainable use of energy based largely on renewable energy sources. Nanocarbon materials play a critical role in this transition, as they are the key materials for components of different devices necessary in enabling this transition (batteries, fuel cells, solar cells, etc.). This issue collects 22 contributions, including one perspective and six review papers on the topic of carbon materials for energy applications, written by well-known experts in this field. It is really an exciting special issue that gives a very updated view of this topic, as well as trends and outlooks in this breakthrough research area. The initial perspective paper introduces the different possibilities offered from the growing level of knowledge in this area, testified from the exponentially rising number of publications. It also discusses the basie concepts for a rational design of these nanomaterials. The lk)llowing six reviews address different specific aspects of synthesis, characterization and use of carbon nanomaterials, from fuel cells to composite electrodes, supercapacitors and photoelectrochemical devices for CO2 conversion. These reviews represent an unique opportunity for the readers to be updated on the latest developments of new carbon families such as fullerene, grapbene, and carbon nanotube, and their derived nanocarbon materials (from carbon quantum dots to nanohorn, nanofiber, nano ribbon, etc.). Second generation nanocarbons, including modification of these nanocarbons by surface functionalization or doping with heteroatoms to create specific tailored properties, and nanoarchitectured supramolecular hybrids, are also discussed. Finally, 1 communication and 14 full articles discuss several aspects of the use of these nanocarbon materials to develop new catalysts for a range of applications (from biomass conversion to Fisher-Tropsch reaction and electrochemical devices) and new materials for energy storage and conversion (adsorption pumps, Li-ion and Li-S batteries, electrodes for electrochemical uses). We thus believe that this special issue dedicated to the use and development of carbon materials for energy applications represents a unique occasion for young and experienced researchers as well as for managers in the field of sustainable energy to have an updated view on this enabling topic for the future of our society. We thus invite all to have this special issue as a privileged component of your bookshelf.展开更多
The use of solar energy to drive the chemical and energy processes,and the chemical storage of solar energy are the key elements to move to a low-carbon economy,sustainable society and to foster energy transition.For ...The use of solar energy to drive the chemical and energy processes,and the chemical storage of solar energy are the key elements to move to a low-carbon economy,sustainable society and to foster energy transition.For this reason,there is a fast-growing scientific interest on this subject,which is part of the general effort for a solar-driven chemistry and energy,the chemistry of the future.To realize this展开更多
Layered transition metal(TM) oxides are one of the most widely used cathode materials in lithium-ion batteries. The atomic configuration in TM layer of these materials is often known to be random when multiple TM elem...Layered transition metal(TM) oxides are one of the most widely used cathode materials in lithium-ion batteries. The atomic configuration in TM layer of these materials is often known to be random when multiple TM elements co-exist in the layer(e.g. Ni, Co and Mn). By contrast, the configuration tends to be ordered if the elements are Li and Mn. Here, by using special quasi-random structures(SQS) algorithm, the essential reasons of the ordering in a promising Li-rich Mn-based cathode material Li2MnO3 are investigated. The difference of internal energy and entropy between ordered and disordered materials is calculated. As a result, based on the Gibbs free energy, it is found that Li2MnO3 should have an ordered structure in TM layer. In comparison, structures with Ni-Mn ratio of 2:1 are predicted to have a disordered TM layer, because the entropy terms have larger impact on the structural ordering than internal energy terms.展开更多
The aim of this work is optimizing the techniques to prepare pure cellulose microspheres, which are used as packing adsorbents for high-performance liquid chromatography. Thereupon, cellulose was dissolved in a pre-co...The aim of this work is optimizing the techniques to prepare pure cellulose microspheres, which are used as packing adsorbents for high-performance liquid chromatography. Thereupon, cellulose was dissolved in a pre-cooled NaOH/urea solution, from which various-size microspheres were prepared. The volume-average diameters were controlled approximately at 30 p,m, 8 ~tm and 4 pm grades when cyclohexane, liquid paraffin and pump oil were used as dispersants, respectively. The present investigations reveal that higher viscosity dispersant is suitable for the preparation of smaller-size microspheres, while larger size microspheres are prepared preferably using lower-viscosity dispersant. The chiral stationary phase derived from 8 μm grade microspheres can separate the enantiomers of efavirenz.展开更多
基金Project(1053320222852)supported by the Graduate Student Innovation Program of Central South University,China。
文摘Permanent ferrite magnet materials are extensively employed due to their exceptional magnetic properties and cost-effectiveness.The fast development in electromobile and household appliance industries contributes to a new progress in permanent ferrite materials.This paper reviews the deveolpement and progress of permanent ferrite magnet industry in recent years.The emergence of new raw material,the advancement of perparation methods and manufacturing techniques,and the potential applications of permanent ferrite materials are introduced and discussed.Specifically,nanocrystallization plays a crucial role in achieving high performance at a low cost and reducing reliance on rare earth resources,and therefore it could be a promising development trendency.
基金supported by Special Coordination Funds for Promoting Science and Technology,sponsored by Japan’s Ministry of Education,Culture,Sports,Science and Technology(MEXT).
文摘Herein,we employ the threshold energy neutron analysis(TENA)technique to introduce the world's first active interrogation system to detect special nuclear materials(SNMs),including U-235 and Pu-239.The system utilizes a DD neutron generator based on inertial electrostatic confinement(IEC)to interrogate suspicious objects.To detect secondary neutrons produced during fission reactions induced in SNMs,a tensioned metastable fluid detector(TMFD)is employed.The current status of the system's development is reported in this paper,accompanied by the results from experiments conducted to detect 10 g of highly enriched uranium(HEU).Notably,the experimental findings demonstrate a distinct difference in the count rates of measurements with and without HEU.This difference in count rates surpasses two times the standard deviation,indicating a confidence level of more than 96% for identifying the presence of HEU.The paper presents and extensively discusses the proof-of-principle experimental results,along with the system's planned trajectory.
基金supported by the National Natural Science Foundation of China(No.11675075)Youth Talent Project of Hunan Province,China(No.2018RS3096)+1 种基金Independent Research Project of Key Laboratory of Plasma Physics,CAEP(No.JCKYS2020212006)Innovation and Entrepreneurship Training Program for College Students of University of South China(No.X2019083)。
文摘The smuggling of special nuclear materials(SNMs)across national borders is becoming a serious threat to nuclear nonproliferation.This paper presents a feasibility study on the rapid interrogation of concealed SNMs by combining scattering and transmission nuclear resonance fluorescence(s NRF and t NRF)spectroscopy.In s NRF spectroscopy,SNMs such as^(235,238)U are excited by a wide-band photon beam of appropriate energy and exhibit unique NRF signatures.Monte Carlo simulations show that one-dimensional scans can realize isotopic identification of concealed^(235,238)U when the detector array used for interrogation has sufficiently high energy resolution.The simulated isotopic ratio^(235U/238)U is in good agreement with the theoretical value when the SNMs are enclosed in relatively thin iron.This interrogation is followed by t NRF spectroscopy using a narrow-band photon beam with the goal of obtaining tomographic images of the concealed SNMs.The reconstructed image clearly reveals the position of the isotope^(235)U inside an iron rod.It is shown that the interrogation time of s NRF and t NRF spectroscopy is one order of magnitude lower than that when only t NRF spectroscopy is used and results in a missed-detection rate of 10^(-3).The proposed method can also be applied for isotopic imaging of other SNMs such as^(239,240)Pu and^(237)Np.
基金financially supported by the Natural National Science Foundation of China(51972281)the foundation of State Key Laboratory of Metastable Materials Science and Technology in Yanshan University。
文摘Various novel carbonaceous materials including carbon nanotubes,nano-onions,carbon microspheres,graphene nanosheets,and carbon microfibers with unique properties,such as tunable surface area and pore size,high chemical stability,cost-effective and facile preparation,have attracted enormous interest for many applications.Also essential,the activation processes play a critical role to achieve these valuable properties.In this review,we provide a thorough analysis of the emerging nano-and microscopic carbon species with special morphology/textures and currently available types of chemical activation agents,and novel activation strategy to enhance electrochemical performance of activated carbon material in electrical energy storage devices including supercapacitor and alkaline ions batteries.A particular emphasis is set on recent advance in activated carbon materials with special morphology/textures for supercapacitors and sodium ion batteries.
文摘Since the Third Plenary Session of the 11 thCentral Committee of the Communist Party of China( CPC),with the promotion and development of traditional Chinese medicine(TCM),the pace of TCM nursing work has been accelerated in nationwide,and a group of integrated Chinese and western medicine nurses have been cultivated preliminarily. However,professional nurses of integrated Chinese and western medicine are still deficient extremely. The target of talent cultivation,based on the theory of "focusing on humanism,expanding diathesis,and enhancing practice to highlight the accommodation and integration of nurses of integrated traditional Chinese and western medicine",is to cultivate competent,practical and interdisciplinary senior nursing talents with strong professional basis,skilled operations,rich humanistic literacy,and sharp innovative spirit who not only master modern nursing knowledge and skills,but also can perform comprehensive nursing under the guidance of TCM theory of holistic concept and syndrome differentiation and nursing. This study,through investigating and analyzing the settings of3-year nursing professional courses in about 20 senior medical colleges,including senior nursing education of TCM,reformed the development of professional nursing courses of integrated Chinese and western medicine and the establishment of educational materials according to the course settings and educational work modes,so as to analyze the current status of nursing education of integrated Chinese and western medicine,determine course targets,and establish course system and educational work modes.
基金support from the Natural Science Foundation of China(91016029,91216302,and 91216301)
文摘The thermal protection materials and structures are widely used in hypersonic vehicles for the purpose of thermal insulation, and their mechanical behavior is one of the key issues in design and manufacture of hypersonic vehicles. It is our great pleasure to present the seven papers in this special subject of Theoretical & Applied Mechanics Letters (TAML) and introduce the recent progresses on the mechanical behavior of thermal protection materials and structures by the authors.
文摘Halide perovskite,a novel semiconductor material,was initially used in solar cells since 2009,and tremendous progresses have been witnessed in the last decade.The power conversion efficiency of the single perovskite solar cells has been incredibly increased up to 25.2%,and close to 30%efficiency was realized in perovskite/silicon tandem solar cells.Recently,the application of perovskite has been extended to the light-emitting diodes and photo-detectors.
文摘In recent years,the Ministry of Agriculture has increased input in agricultural scientific research projects.As a result,the procurement amount and quantity of special materials are increasing gradually,and the management of special materials becomes more standardized.In order to do well in management of special materials,the authors made exploration and thinking about further strengthening management of special materials in combination with actual conditions,including establishing regulations and systems,enhancing procurement process,strengthening requisition and safekeeping,and reinforcing general ledger management of special materials.
文摘Chinese top planner-State Development and Reform Commission,has decided to organize and coordinate an implementation of a special project for high tech industrialization of fiber-reinforced compound materials in 2008 up to 2009.The decision has recently been issued in its national circular(doc. 3177,Yr.2007)to call for local enterprises to apply for this special project support.
文摘Lying between radio frequency and infrared radiation, terahertz (THz) wave encounters lots of difficulties to produce, detect, transmit, and modulate. Great efforts have been made to construct THz devices, including sources, detectors, switches, modulators, lenses, and filters. However, only moderate progresses have been made in THz generation and detection. Furthermore, the devices and techniques to control and manipulate THz waves are still in its infancy. Therefore, it is still a challenge to date to develop sophisticated THz application systems such as communication, sensing, safety inspection, imaging and medical diagnose systems. This difficult position of THz wave is essential due to the deficiency of THz materials having a suitable THz electromagnetic response, as compared to its neighboring microwave and infrared regime. Practicable material will largely push the THz technology to real-world applications. The GaAs/AlxGa~_xAs material system, for example, is the heart of THz quantum cascade lasers. High quality NbN films, again, set the basis of THz hot electron bolometer.
文摘Graphene, a single layer of graphite, has been one of the first real two dimensional (2D) materials isolated in 2004. Thus, graphene is becoming a cutting edge material that opens up new horizons to a whole family of 2D materials beyond the limited current applicability of graphene. The unique advantages of graphene and analogue 2D materials, such as atomic-scale thickness, high specific surface area, mechanically flexible robustness, superior storage capacity, endow them as high-performance electrodes lbr electrochemical energy storage devices. Although it is hard to say whether or not graphene and 2D materials will be implemented in future energy technologies, the recent achievements in this field demonstrate that their roles will be noticeable in the near future.
文摘A new way for the synthesis of human interferon—α_A monoclonal antibody (IFN-α_A-McAb) bound to silica gel packing material in high-performance affinity chromatography (HPAFC) has been developed. The high coupling efficiency and specific activity of IFN—α_A-McAb can be obtained by activated diol-silica gel with activating agent. After purification using this packing material in HPAFC, the specific activity of recombinant human interferon-α_A (rIFN-α_A) rose up to 1.03×10~7IU/mg protein and the purification efficiency is appoximately 100 times.
文摘The rising cost and limited availability of fossil fuels, and the increasing concerns related to their role on global pollution and greenhouse effect have pushed considerably the need to accelerate the transition to a more sustainable use of energy based largely on renewable energy sources. Nanocarbon materials play a critical role in this transition, as they are the key materials for components of different devices necessary in enabling this transition (batteries, fuel cells, solar cells, etc.). This issue collects 22 contributions, including one perspective and six review papers on the topic of carbon materials for energy applications, written by well-known experts in this field. It is really an exciting special issue that gives a very updated view of this topic, as well as trends and outlooks in this breakthrough research area. The initial perspective paper introduces the different possibilities offered from the growing level of knowledge in this area, testified from the exponentially rising number of publications. It also discusses the basie concepts for a rational design of these nanomaterials. The lk)llowing six reviews address different specific aspects of synthesis, characterization and use of carbon nanomaterials, from fuel cells to composite electrodes, supercapacitors and photoelectrochemical devices for CO2 conversion. These reviews represent an unique opportunity for the readers to be updated on the latest developments of new carbon families such as fullerene, grapbene, and carbon nanotube, and their derived nanocarbon materials (from carbon quantum dots to nanohorn, nanofiber, nano ribbon, etc.). Second generation nanocarbons, including modification of these nanocarbons by surface functionalization or doping with heteroatoms to create specific tailored properties, and nanoarchitectured supramolecular hybrids, are also discussed. Finally, 1 communication and 14 full articles discuss several aspects of the use of these nanocarbon materials to develop new catalysts for a range of applications (from biomass conversion to Fisher-Tropsch reaction and electrochemical devices) and new materials for energy storage and conversion (adsorption pumps, Li-ion and Li-S batteries, electrodes for electrochemical uses). We thus believe that this special issue dedicated to the use and development of carbon materials for energy applications represents a unique occasion for young and experienced researchers as well as for managers in the field of sustainable energy to have an updated view on this enabling topic for the future of our society. We thus invite all to have this special issue as a privileged component of your bookshelf.
文摘The use of solar energy to drive the chemical and energy processes,and the chemical storage of solar energy are the key elements to move to a low-carbon economy,sustainable society and to foster energy transition.For this reason,there is a fast-growing scientific interest on this subject,which is part of the general effort for a solar-driven chemistry and energy,the chemistry of the future.To realize this
基金Supported by National Key R&D Program of China(2016YFB0700600)Soft Science Research Project of Guangdong Province(No.2017B030301013)
文摘Layered transition metal(TM) oxides are one of the most widely used cathode materials in lithium-ion batteries. The atomic configuration in TM layer of these materials is often known to be random when multiple TM elements co-exist in the layer(e.g. Ni, Co and Mn). By contrast, the configuration tends to be ordered if the elements are Li and Mn. Here, by using special quasi-random structures(SQS) algorithm, the essential reasons of the ordering in a promising Li-rich Mn-based cathode material Li2MnO3 are investigated. The difference of internal energy and entropy between ordered and disordered materials is calculated. As a result, based on the Gibbs free energy, it is found that Li2MnO3 should have an ordered structure in TM layer. In comparison, structures with Ni-Mn ratio of 2:1 are predicted to have a disordered TM layer, because the entropy terms have larger impact on the structural ordering than internal energy terms.
基金Funded by National Natural Science Foundation of China(Nos.50973086 and 51273073)Hubei Provincial Department of Education of China(No.Z20081501)
文摘The aim of this work is optimizing the techniques to prepare pure cellulose microspheres, which are used as packing adsorbents for high-performance liquid chromatography. Thereupon, cellulose was dissolved in a pre-cooled NaOH/urea solution, from which various-size microspheres were prepared. The volume-average diameters were controlled approximately at 30 p,m, 8 ~tm and 4 pm grades when cyclohexane, liquid paraffin and pump oil were used as dispersants, respectively. The present investigations reveal that higher viscosity dispersant is suitable for the preparation of smaller-size microspheres, while larger size microspheres are prepared preferably using lower-viscosity dispersant. The chiral stationary phase derived from 8 μm grade microspheres can separate the enantiomers of efavirenz.