Inter-growth bismuth layer-structured ferroelectrics(BLSFs), Bi_4Ti_3O_(12)-Na_(0.5)Bi_(4.5)Ti_4O_(15)(BIT-NBT), were successfully synthesized using the traditional solid-state reaction method. X-ray diffraction(XRD) ...Inter-growth bismuth layer-structured ferroelectrics(BLSFs), Bi_4Ti_3O_(12)-Na_(0.5)Bi_(4.5)Ti_4O_(15)(BIT-NBT), were successfully synthesized using the traditional solid-state reaction method. X-ray diffraction(XRD) Rietveld refinements were conducted using GSAS software. Good agreement and low residual are obtained. The XRD diffraction peaks can be well indexed into I2 cm space group. The inter-growth structure was further observed in the high-resolution TEM image. Dielectric and impedance properties were measured and systematically analyzed. At the temperature range 763-923 K(below T_c), doubly ionized oxygen vacancies(OVs) are localized and the short-range hopping leads to the relaxation processes with an activation energy of 0.79-1.01 eV. Above T_c, the doubly charged OVs are delocalized and become free ones, which contribute to the long-range dc conduction. The reduction in relaxation species gives rise to a higher relaxation activation energy ~ 1.6 eV.展开更多
Greenhouse gas emissions from waste plastics have caused global warming all over the world,which has been a central threat to the ecological environment for humans,flora and fauna.Among waste plastics,waste polyethyle...Greenhouse gas emissions from waste plastics have caused global warming all over the world,which has been a central threat to the ecological environment for humans,flora and fauna.Among waste plastics,waste polyethylene terephthalate(PET)is attractive due to its excellent stability and degradation-resistant.Therefore,merging China’s carbon peak and carbon neutrality goals would be beneficial.In this review,we summarize the current state-of-the-art of carbon emission decrease from a multi-scale perspective technologically.We suggest that the carbon peak for waste PET can be achieved by employing the closed-loop supply chain,including recycling,biomass utilization,carbon capture and utilization.Waste PET can be a valuable and renewable resource in the whole life cycle.Undoubtedly,all kinds of PET plastics can be ultimately converted into CO_(2),which can also be feedstock for various kinds of chemical products,including ethyl alcohol,formic acid,soda ash,PU,starch and so on.As a result,the closed-loop supply chain can help the PET plastics industry drastically reduce its carbon footprint.展开更多
In recent years, due to their high photo-to-electric power conversion efficiency(PCE)(up to 23%(certified)) and low cost, perovskite solar cells(PSCs) have attracted a great deal of attention in photovoltaics field. T...In recent years, due to their high photo-to-electric power conversion efficiency(PCE)(up to 23%(certified)) and low cost, perovskite solar cells(PSCs) have attracted a great deal of attention in photovoltaics field. The high PCE can be attributed to the excellent physical properties of organic–inorganic hybrid perovskite materials, such as a long charge diffusion length and a high absorption coefficient in the visible range. There are different diffusion lengths of holes in electrons in a PSC device, and thus the electron transporting layer(ETL) plays a critical role in the performance of PSCs. An alternative for TiO2, to the most common ETL material is SnO2, which has similar physical properties to TiO2 but with much higher electron mobility, which is beneficial for electron extraction. In addition, there are many facile methods to fabricate SnO2 nanomaterials with low cost and low energy consumption. In this review paper, we focus on recent developments in SnO2 as the ETL of PSCs. The fabrication methods of SnO2 materials are briefly introduced. The influence of multiple Sn O2 types in the ETL on the performance of PSCs is then reviewed. Different methods for improving the PCE and long-term stability of PSCs based on SnO2 ETL are also summarized. The review provides a systematic and comprehensive understanding of the influence of different Sn O2 ETL types on PSC performance and potentially motivates further development of PSCs with an extension to SnO2-based PSCs.展开更多
CeO2 nanorods were synthesized by a hydrothermal method at 160℃ from CeC16-6H20 and NH3.H20 in the presence of an ionic liquid 1-butyl-3-methyl-imidazolium chloride （[Bmim]C1）. The phase and morphology of the resul...CeO2 nanorods were synthesized by a hydrothermal method at 160℃ from CeC16-6H20 and NH3.H20 in the presence of an ionic liquid 1-butyl-3-methyl-imidazolium chloride （[Bmim]C1）. The phase and morphology of the result- ing products were characterized by X-ray diffraction （XRD） and high-resolution transmission electron microscopy （HRTEM）, respectively. The results reveal that morphology of CeO2 prepared in the presence of the ionic liquid is nano- rod while it changes to irregular nanoparticle without ionic liquid. The resulting nanorods are about 13-25 nm in diameter and 200-500 nm in length. With the increase of ionic concentration, nanorods were disappeared gradually and nanoparticles were obtained. Moreover, increasing the hydrothermal temperature to 180℃, nanospheres at size of 19-24 nm could be synthesized by aggregation of-2 nm nanocrystals.展开更多
In this paper, we study the existence of least energy sign-changing solutions for a Kirchhoff-type problem involving the fractional Laplacian operator. By using the constraint variation method and quantitative deforma...In this paper, we study the existence of least energy sign-changing solutions for a Kirchhoff-type problem involving the fractional Laplacian operator. By using the constraint variation method and quantitative deformation lemma, we obtain a least energy nodal solution ubfor the given problem. Moreover, we show that the energy of ubis strictly larger than twice the ground state energy. We also give a convergence property of ubas b↘0, where b is regarded as a positive parameter.展开更多
A shard of Chinese underglaze copper-red porcelain from the Yuan dynasty (AD 1271–1368) made in the Jingdezhen kiln was measured by synchrotron radiation- induced X-ray fluorescence mapping and X-ray absorption near-...A shard of Chinese underglaze copper-red porcelain from the Yuan dynasty (AD 1271–1368) made in the Jingdezhen kiln was measured by synchrotron radiation- induced X-ray fluorescence mapping and X-ray absorption near-edge spectroscopy to investigate the influence of copper element distribution and speciation on the color of porcelain. In black-colored region, copper accumulates at the interface between the body and glaze layers with metallic copper particles as the main speciation. In contrast, Cu is irregularly distributed in the red-colored region with multi-valence speciation. The differences in Cu distribution and speciation in black- and red-colored regions indicate that they are the main factors influencing the different colors of copper-red underglaze porcelain.展开更多
We propose an ultrathin wide-band metamaterial absorber(MA) based on a Minkowski(MIK) fractal frequency selective surface and resistive film.This absorber consists of a periodic arrangement of dielectric substrates sa...We propose an ultrathin wide-band metamaterial absorber(MA) based on a Minkowski(MIK) fractal frequency selective surface and resistive film.This absorber consists of a periodic arrangement of dielectric substrates sandwiched with an MIK fractal loop structure electric resonator and a resistive film.The finite element method is used to simulate and analyze the absorption of the MA.Compared with the MA-backed copper film,the designed MA-backed resistive film exhibits an absorption of 90% at a frequency region of 2 GHz-20 GHz.The power loss density distribution of the MA is further illustrated to explain the mechanism of the proposed MA.Simulated absorptions at different incidence cases indicate that this absorber is polarization-insensitive and wide-angled.Finally,further simulated results indicate that the surface resistance of the resistive film and the dielectric constant of the substrate can affect the absorbing property of the MA.This absorber may be used in many military fields.展开更多
Mobile edge caching technology is gaining more and more attention because it can effectively improve the Quality of Experience (QoE) of users and reduce backhaul burden. This paper aims to improve the utility of mobil...Mobile edge caching technology is gaining more and more attention because it can effectively improve the Quality of Experience (QoE) of users and reduce backhaul burden. This paper aims to improve the utility of mobile edge caching technology from the perspectie of caching resource management by examining a network composed of one operator, multiple users and Content Providers (CPs). The caching resource management model is constructed on the premise of fully considering the QoE of users and the servicing capability of the Base Station (BS). In order to create the best caching resource allocation scheme, the original problem is transformed into a multi-leader multi-follower Stackelberg game model through the analysis of the system model. The strategy combinations and the utility functions of players are analyzed. The existence and uniqueness of the Nash Equilibrium (NE) solution are also analyzed and proved. The optimal strategy combinations and the best responses are deduced in detail. Simulation results and analysis show that the proposed model and algorithm can achieve the optimal allocation of caching resource and improve the QoE of users.展开更多
Template-free nanosized ZSM-5 seeds with an average size of 15 nm were prepared from a synthesis solution with the composition 12Na2O∶100SiO2∶2Al2O3∶2500H2O. By the use of these seeds, thin ZSM-5 zeolite membranes ...Template-free nanosized ZSM-5 seeds with an average size of 15 nm were prepared from a synthesis solution with the composition 12Na2O∶100SiO2∶2Al2O3∶2500H2O. By the use of these seeds, thin ZSM-5 zeolite membranes were prepared on the outer surface of a porous α-alumina tube with a pore size of 2 μm in a gel system by varying-concentration synthesis with organic-free template. The first composition synthesis sol-gel was the same as seeds of molar composition and the second one was 12Na2O∶100SiO2∶2Al2O3∶5000H2O at 180 ℃ for 10 h, respectively. XRD shows that the film consists of well-crystallized ZSM-5 zeolite. SEM investigation indicats that the zeolite films on the supports are defect free and the film thickness is approximately 8 μm. The permeances for H2, N2, CH4 and CO2 are 8.94×10-7, 3.27×10-7, 3.9×10-7, 3.14×10-7 and 0.874×10-7 mol·m2·s-1·Pa-1, respectively. The ideal selectivity of membrane at room temperature for H2/CO2, H2/N2, H2/CH4 are 2.84, 2.73 and 2.29, respectively.展开更多
<span style="font-family:Verdana;"> <p class="MsoNormal"> <span lang="EN-US" style="" color:black;"="">Recently, the life of worldwide human bei...<span style="font-family:Verdana;"> <p class="MsoNormal"> <span lang="EN-US" style="" color:black;"="">Recently, the life of worldwide human beings has been endangering by the spreading of </span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">pneu</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">- </span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">monia</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">-</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">causing virus, such as Coronavirus, COVID-19, and H1N1. To develop effective </span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">drugs against Coronavirus, knowledge of protein subcellular localization is prerequisite. In 2019, a predictor called “pLoc_bal-mEuk” was developed for identifying the subcellular localization of eukaryotic proteins. Its predicted results are significantly better than its counterparts, particularly for those proteins that may simultaneously occur or move between two or more subcellular location sites. However, more efforts are definitely needed to further improve its power since pLoc_bal-mEuk was still not trained by a “deep learning”, a very powerful technique developed recently. The present study was devoted to incorporating the “deep</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">- </span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">learning” technique and develop</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">ed</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;"> a new predictor called “pLoc_Deep-mEuk”. The global absolute true rate achieved by the new predictor is over 81% and its local accuracy is over 90%. Both are overwhelmingly superior to its counterparts. Moreover, a user-friendly web-</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;"> </span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">server for the new predictor has been well established at <a href="http://www.jci-bioinfo.cn/pLoc_Deep-mEuk/">http://www.jci-bioinfo.cn/pLoc_Deep-mEuk/</a>, by which the majority of experimental scientists can easily get their desired data.</span> </p> </span>展开更多
<p class="MsoNormal"> <span lang="EN-US" style="" color:black;"="">The recent worldwide spreading of pneumonia-causing virus, such as Coronavirus, </span>...<p class="MsoNormal"> <span lang="EN-US" style="" color:black;"="">The recent worldwide spreading of pneumonia-causing virus, such as Coronavirus, </span><span "="" style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">COVID-19, and H1N1, has been endangering the life of human beings all around the world. In order to really understand the biological process within a cell level and provide useful clues to develop antiviral drugs, information of virus protein subcellular localization is vitally important. In view of this, a CNN based virus protein subcellular localization predictor called “pLoc_Deep-mVirus” was developed. The predictor is particularly useful in dealing with the multi-sites systems in which some proteins may simultaneously occur in two or more different organelles that are the current focus of pharmaceutical industry. The global absolute true rate achieved by the new predictor is over 97% and its local accuracy is over 98%. Both are transcending other existing state-of-the-art predictors significantly. It has not escaped our notice that the deep-learning treatment can be used to deal with many other biological systems as well. To maximize the convenience for most experimental scientists, a user-friendly web-server for the new predictor has been established at <a href="http://www.jci-bioinfo.cn/pLoc_Deep-mVirus/">http://www.jci-bioinfo.cn/pLoc_Deep-mVirus/</a>.</span> </p>展开更多
Recently, the life of human beings around the entire world has been endangering by the spreading of pneumonia-causing virus, such as Coronavirus, COVID-19, and H1N1. To develop effective drugs against Coronavirus, kno...Recently, the life of human beings around the entire world has been endangering by the spreading of pneumonia-causing virus, such as Coronavirus, COVID-19, and H1N1. To develop effective drugs against Coronavirus, knowledge of protein subcellular localization is indispensable. In 2019, a predictor called “pLoc_bal-mHum” was developed for identifying the subcellular localization of human proteins. Its predicted results are significantly better than its counterparts, particularly for those proteins that may simultaneously occur or move between two or more subcellular location sites. However, more efforts are definitely needed to further improve its power since pLoc_bal-mHum was still not trained by a “deep learning”, a very powerful technique developed recently. The present study was devoted to incorporate the “deep-learning” technique and develop a new predictor called “pLoc_Deep-mHum”. The global absolute true rate achieved by the new predictor is over 81% and its local accuracy is over 90%. Both are overwhelmingly superior to its counterparts. Moreover, a user-friendly web-server for the new predictor has been well established at http://www.jci-bioinfo.cn/pLoc_Deep-mHum/, which will become a very useful tool for fighting pandemic coronavirus and save the mankind of this planet.展开更多
The basic unit in life is cell.?It contains many protein molecules located at its different organelles. The growth and reproduction of a cell as well as most of its other biological functions are performed via these p...The basic unit in life is cell.?It contains many protein molecules located at its different organelles. The growth and reproduction of a cell as well as most of its other biological functions are performed via these proteins. But proteins in different organelles or subcellular locations have different functions. Facing?the avalanche of protein sequences generated in the postgenomic age, we are challenged to develop high throughput tools for identifying the subcellular localization of proteins based on their sequence information alone. Although considerable efforts have been made in this regard, the problem is far apart from being solved yet. Most existing methods can be used to deal with single-location proteins only. Actually, proteins with multi-locations may have some special biological functions that are particularly important for drug targets. Using the ML-GKR (Multi-Label Gaussian Kernel Regression) method,?we developed a new predictor called “pLoc-mGpos” by in-depth extracting the key information from GO (Gene Ontology) into the Chou’s general PseAAC (Pseudo Amino Acid Composition)?for predicting the subcellular localization of Gram-positive bacterial proteins with both single and multiple location sites. Rigorous cross-validation on a same stringent benchmark dataset indicated that the proposed pLoc-mGpos predictor is remarkably superior to “iLoc-Gpos”, the state-of-the-art predictor for the same purpose.?To maximize the convenience of most experimental scientists, a user-friendly web-server for the new powerful predictor has been established at http://www.jci-bioinfo.cn/pLoc-mGpos/, by which users can easily get their desired results without the need to go through the complicated mathematics involved.展开更多
Lithium metal anode is regarded as the ultimate choice for next-generation energy storage systems,due to the lowest negative electrochemical potential and super high theoretical specific capacity.However,the growth of...Lithium metal anode is regarded as the ultimate choice for next-generation energy storage systems,due to the lowest negative electrochemical potential and super high theoretical specific capacity.However,the growth of lithium dendrite during the cycling process is still one of the most critical bottlenecks for its application.In this work,a slurry-like hybrid electrolyte is proposed towards the application for lithium metal anode,which is composed of a liquid electrolyte part and a nanometric silane-Al2O3 particle part.The hybrid electrolyte shows high ionic conductivity(3.89×10-3 S cm-1 at 25℃)and lithium-ion transference number(0.88).Especially,the resistance of hybrid electrolyte decreases compared to that of liquid electrolyte,while the viscosity of hybrid electrolyte increases.It is demonstrated that the hybrid electrolyte can effectively suppress the growth of lithium dendrite.Stable cycling of Li/Li cells at a current density up to 1 mA cm-2 is possible.The hybrid electrolyte helps to uniform the lithium ion flux inside the battery and partly comes from the formation of a rigid and highly conductive hybrid interfacial layer on the surface of lithium metal.This work not only provides a fresh way to stabilize lithium metal anode but also sheds light on further research for electrolyte optimization and design of lithium metal battery system.展开更多
In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is investigated.In...In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is investigated.In particular,an Euler-Euler two-phase flow model is used to analyze the dynamics of both SiC particles and air.The numerical results show that by setting a certain reverse rotating speed of the rotating chamber,the accumulation of SiC particles on the wall can be improved,i.e.,their direction of motion in proximity to the wall can be changed and particles can be forced to re-join the granulation process.Experimental tests conducted to verify the reliability of the numerical findings,demonstrate that when the reverse rotating speed of the rotating chamber is 4 r/min,the sphericity of SiC particles in the rotating chamber is the highest and the fluidity is the best possible one.展开更多
基金Supported by the National Natural Science Foundation of China under No 50562002, the New Century Excellent Talents in University （NCET-06-0576）, the Key Industrial Project of Jiangxi Provincial Department of Science and Technology [2005]52, Jiangxi Provincial Department of Education [2005]217, the Natural Science Foundation of Jiangxi Province （No 0650074）, and the Center for Smart Materials of The Hong Kong Polytechnic University.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51562014,51262009,and 51602135)
文摘Inter-growth bismuth layer-structured ferroelectrics(BLSFs), Bi_4Ti_3O_(12)-Na_(0.5)Bi_(4.5)Ti_4O_(15)(BIT-NBT), were successfully synthesized using the traditional solid-state reaction method. X-ray diffraction(XRD) Rietveld refinements were conducted using GSAS software. Good agreement and low residual are obtained. The XRD diffraction peaks can be well indexed into I2 cm space group. The inter-growth structure was further observed in the high-resolution TEM image. Dielectric and impedance properties were measured and systematically analyzed. At the temperature range 763-923 K(below T_c), doubly ionized oxygen vacancies(OVs) are localized and the short-range hopping leads to the relaxation processes with an activation energy of 0.79-1.01 eV. Above T_c, the doubly charged OVs are delocalized and become free ones, which contribute to the long-range dc conduction. The reduction in relaxation species gives rise to a higher relaxation activation energy ~ 1.6 eV.
基金The authors acknowledge the financial support provided by the Key R&D Program of Shaanxi Province(No.2022SF-168)Xi’an Programs for Science and Technology Plan(Nos.2020KJRC0090 and 21XJZZ0045)+5 种基金Xi’an Beilin District Programs for Science and Technology Plan(No.GX2247)the Outstanding Chinese and Foreign Youth Exchange Program of China Association for Science and Technology(CAST)in 2019the Opening Project of Shanxi Key Laboratory of Advanced Manufacturing Technology(No.XJZZ202001)the Scientific Research Project of Shaanxi Education Department(No.20JS108)Open Foundation of Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry,Ministry of Education,Shaanxi University of Science and Technology(No.KFKT2021-01)Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry and Technology,Shaanxi University of Science and Technology(No.KFKT2021-01).
文摘Greenhouse gas emissions from waste plastics have caused global warming all over the world,which has been a central threat to the ecological environment for humans,flora and fauna.Among waste plastics,waste polyethylene terephthalate(PET)is attractive due to its excellent stability and degradation-resistant.Therefore,merging China’s carbon peak and carbon neutrality goals would be beneficial.In this review,we summarize the current state-of-the-art of carbon emission decrease from a multi-scale perspective technologically.We suggest that the carbon peak for waste PET can be achieved by employing the closed-loop supply chain,including recycling,biomass utilization,carbon capture and utilization.Waste PET can be a valuable and renewable resource in the whole life cycle.Undoubtedly,all kinds of PET plastics can be ultimately converted into CO_(2),which can also be feedstock for various kinds of chemical products,including ethyl alcohol,formic acid,soda ash,PU,starch and so on.As a result,the closed-loop supply chain can help the PET plastics industry drastically reduce its carbon footprint.
基金supported by the National Natural Science Foundation of China(NSFC 61574009 and 11574014)
文摘In recent years, due to their high photo-to-electric power conversion efficiency(PCE)(up to 23%(certified)) and low cost, perovskite solar cells(PSCs) have attracted a great deal of attention in photovoltaics field. The high PCE can be attributed to the excellent physical properties of organic–inorganic hybrid perovskite materials, such as a long charge diffusion length and a high absorption coefficient in the visible range. There are different diffusion lengths of holes in electrons in a PSC device, and thus the electron transporting layer(ETL) plays a critical role in the performance of PSCs. An alternative for TiO2, to the most common ETL material is SnO2, which has similar physical properties to TiO2 but with much higher electron mobility, which is beneficial for electron extraction. In addition, there are many facile methods to fabricate SnO2 nanomaterials with low cost and low energy consumption. In this review paper, we focus on recent developments in SnO2 as the ETL of PSCs. The fabrication methods of SnO2 materials are briefly introduced. The influence of multiple Sn O2 types in the ETL on the performance of PSCs is then reviewed. Different methods for improving the PCE and long-term stability of PSCs based on SnO2 ETL are also summarized. The review provides a systematic and comprehensive understanding of the influence of different Sn O2 ETL types on PSC performance and potentially motivates further development of PSCs with an extension to SnO2-based PSCs.
文摘CeO2 nanorods were synthesized by a hydrothermal method at 160℃ from CeC16-6H20 and NH3.H20 in the presence of an ionic liquid 1-butyl-3-methyl-imidazolium chloride （[Bmim]C1）. The phase and morphology of the result- ing products were characterized by X-ray diffraction （XRD） and high-resolution transmission electron microscopy （HRTEM）, respectively. The results reveal that morphology of CeO2 prepared in the presence of the ionic liquid is nano- rod while it changes to irregular nanoparticle without ionic liquid. The resulting nanorods are about 13-25 nm in diameter and 200-500 nm in length. With the increase of ionic concentration, nanorods were disappeared gradually and nanoparticles were obtained. Moreover, increasing the hydrothermal temperature to 180℃, nanospheres at size of 19-24 nm could be synthesized by aggregation of-2 nm nanocrystals.
基金supported by the NSFC(11501231)the "Fundamental Research Funds for the Central Universities"(WUT2017IVA077,2018IB014)
文摘In this paper, we study the existence of least energy sign-changing solutions for a Kirchhoff-type problem involving the fractional Laplacian operator. By using the constraint variation method and quantitative deformation lemma, we obtain a least energy nodal solution ubfor the given problem. Moreover, we show that the energy of ubis strictly larger than twice the ground state energy. We also give a convergence property of ubas b↘0, where b is regarded as a positive parameter.
基金supported by Natural Science Foundation of China(Nos.51762027 and 11875312)Jiangxi Collaborative Innovation Center of Ceramic Relics Conservation and Imperial Kiln Research
文摘A shard of Chinese underglaze copper-red porcelain from the Yuan dynasty (AD 1271–1368) made in the Jingdezhen kiln was measured by synchrotron radiation- induced X-ray fluorescence mapping and X-ray absorption near-edge spectroscopy to investigate the influence of copper element distribution and speciation on the color of porcelain. In black-colored region, copper accumulates at the interface between the body and glaze layers with metallic copper particles as the main speciation. In contrast, Cu is irregularly distributed in the red-colored region with multi-valence speciation. The differences in Cu distribution and speciation in black- and red-colored regions indicate that they are the main factors influencing the different colors of copper-red underglaze porcelain.
基金supported by the National Natural Science Foundation of China (Grant No. 51207060)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20090142110004)
文摘We propose an ultrathin wide-band metamaterial absorber(MA) based on a Minkowski(MIK) fractal frequency selective surface and resistive film.This absorber consists of a periodic arrangement of dielectric substrates sandwiched with an MIK fractal loop structure electric resonator and a resistive film.The finite element method is used to simulate and analyze the absorption of the MA.Compared with the MA-backed copper film,the designed MA-backed resistive film exhibits an absorption of 90% at a frequency region of 2 GHz-20 GHz.The power loss density distribution of the MA is further illustrated to explain the mechanism of the proposed MA.Simulated absorptions at different incidence cases indicate that this absorber is polarization-insensitive and wide-angled.Finally,further simulated results indicate that the surface resistance of the resistive film and the dielectric constant of the substrate can affect the absorbing property of the MA.This absorber may be used in many military fields.
文摘Mobile edge caching technology is gaining more and more attention because it can effectively improve the Quality of Experience (QoE) of users and reduce backhaul burden. This paper aims to improve the utility of mobile edge caching technology from the perspectie of caching resource management by examining a network composed of one operator, multiple users and Content Providers (CPs). The caching resource management model is constructed on the premise of fully considering the QoE of users and the servicing capability of the Base Station (BS). In order to create the best caching resource allocation scheme, the original problem is transformed into a multi-leader multi-follower Stackelberg game model through the analysis of the system model. The strategy combinations and the utility functions of players are analyzed. The existence and uniqueness of the Nash Equilibrium (NE) solution are also analyzed and proved. The optimal strategy combinations and the best responses are deduced in detail. Simulation results and analysis show that the proposed model and algorithm can achieve the optimal allocation of caching resource and improve the QoE of users.
基金This work was financially supported by the Specialized Research Fund for the Doctoral Program of High Education (SRFDP)(No.B20020288015).
文摘Template-free nanosized ZSM-5 seeds with an average size of 15 nm were prepared from a synthesis solution with the composition 12Na2O∶100SiO2∶2Al2O3∶2500H2O. By the use of these seeds, thin ZSM-5 zeolite membranes were prepared on the outer surface of a porous α-alumina tube with a pore size of 2 μm in a gel system by varying-concentration synthesis with organic-free template. The first composition synthesis sol-gel was the same as seeds of molar composition and the second one was 12Na2O∶100SiO2∶2Al2O3∶5000H2O at 180 ℃ for 10 h, respectively. XRD shows that the film consists of well-crystallized ZSM-5 zeolite. SEM investigation indicats that the zeolite films on the supports are defect free and the film thickness is approximately 8 μm. The permeances for H2, N2, CH4 and CO2 are 8.94×10-7, 3.27×10-7, 3.9×10-7, 3.14×10-7 and 0.874×10-7 mol·m2·s-1·Pa-1, respectively. The ideal selectivity of membrane at room temperature for H2/CO2, H2/N2, H2/CH4 are 2.84, 2.73 and 2.29, respectively.
文摘<span style="font-family:Verdana;"> <p class="MsoNormal"> <span lang="EN-US" style="" color:black;"="">Recently, the life of worldwide human beings has been endangering by the spreading of </span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">pneu</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">- </span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">monia</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">-</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">causing virus, such as Coronavirus, COVID-19, and H1N1. To develop effective </span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">drugs against Coronavirus, knowledge of protein subcellular localization is prerequisite. In 2019, a predictor called “pLoc_bal-mEuk” was developed for identifying the subcellular localization of eukaryotic proteins. Its predicted results are significantly better than its counterparts, particularly for those proteins that may simultaneously occur or move between two or more subcellular location sites. However, more efforts are definitely needed to further improve its power since pLoc_bal-mEuk was still not trained by a “deep learning”, a very powerful technique developed recently. The present study was devoted to incorporating the “deep</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">- </span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">learning” technique and develop</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">ed</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;"> a new predictor called “pLoc_Deep-mEuk”. The global absolute true rate achieved by the new predictor is over 81% and its local accuracy is over 90%. Both are overwhelmingly superior to its counterparts. Moreover, a user-friendly web-</span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;"> </span><span style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">server for the new predictor has been well established at <a href="http://www.jci-bioinfo.cn/pLoc_Deep-mEuk/">http://www.jci-bioinfo.cn/pLoc_Deep-mEuk/</a>, by which the majority of experimental scientists can easily get their desired data.</span> </p> </span>
文摘<p class="MsoNormal"> <span lang="EN-US" style="" color:black;"="">The recent worldwide spreading of pneumonia-causing virus, such as Coronavirus, </span><span "="" style="font-variant-ligatures:normal;font-variant-caps:normal;orphans:2;text-align:start;widows:2;-webkit-text-stroke-width:0px;text-decoration-style:initial;text-decoration-color:initial;word-spacing:0px;">COVID-19, and H1N1, has been endangering the life of human beings all around the world. In order to really understand the biological process within a cell level and provide useful clues to develop antiviral drugs, information of virus protein subcellular localization is vitally important. In view of this, a CNN based virus protein subcellular localization predictor called “pLoc_Deep-mVirus” was developed. The predictor is particularly useful in dealing with the multi-sites systems in which some proteins may simultaneously occur in two or more different organelles that are the current focus of pharmaceutical industry. The global absolute true rate achieved by the new predictor is over 97% and its local accuracy is over 98%. Both are transcending other existing state-of-the-art predictors significantly. It has not escaped our notice that the deep-learning treatment can be used to deal with many other biological systems as well. To maximize the convenience for most experimental scientists, a user-friendly web-server for the new predictor has been established at <a href="http://www.jci-bioinfo.cn/pLoc_Deep-mVirus/">http://www.jci-bioinfo.cn/pLoc_Deep-mVirus/</a>.</span> </p>
文摘Recently, the life of human beings around the entire world has been endangering by the spreading of pneumonia-causing virus, such as Coronavirus, COVID-19, and H1N1. To develop effective drugs against Coronavirus, knowledge of protein subcellular localization is indispensable. In 2019, a predictor called “pLoc_bal-mHum” was developed for identifying the subcellular localization of human proteins. Its predicted results are significantly better than its counterparts, particularly for those proteins that may simultaneously occur or move between two or more subcellular location sites. However, more efforts are definitely needed to further improve its power since pLoc_bal-mHum was still not trained by a “deep learning”, a very powerful technique developed recently. The present study was devoted to incorporate the “deep-learning” technique and develop a new predictor called “pLoc_Deep-mHum”. The global absolute true rate achieved by the new predictor is over 81% and its local accuracy is over 90%. Both are overwhelmingly superior to its counterparts. Moreover, a user-friendly web-server for the new predictor has been well established at http://www.jci-bioinfo.cn/pLoc_Deep-mHum/, which will become a very useful tool for fighting pandemic coronavirus and save the mankind of this planet.
文摘The basic unit in life is cell.?It contains many protein molecules located at its different organelles. The growth and reproduction of a cell as well as most of its other biological functions are performed via these proteins. But proteins in different organelles or subcellular locations have different functions. Facing?the avalanche of protein sequences generated in the postgenomic age, we are challenged to develop high throughput tools for identifying the subcellular localization of proteins based on their sequence information alone. Although considerable efforts have been made in this regard, the problem is far apart from being solved yet. Most existing methods can be used to deal with single-location proteins only. Actually, proteins with multi-locations may have some special biological functions that are particularly important for drug targets. Using the ML-GKR (Multi-Label Gaussian Kernel Regression) method,?we developed a new predictor called “pLoc-mGpos” by in-depth extracting the key information from GO (Gene Ontology) into the Chou’s general PseAAC (Pseudo Amino Acid Composition)?for predicting the subcellular localization of Gram-positive bacterial proteins with both single and multiple location sites. Rigorous cross-validation on a same stringent benchmark dataset indicated that the proposed pLoc-mGpos predictor is remarkably superior to “iLoc-Gpos”, the state-of-the-art predictor for the same purpose.?To maximize the convenience of most experimental scientists, a user-friendly web-server for the new powerful predictor has been established at http://www.jci-bioinfo.cn/pLoc-mGpos/, by which users can easily get their desired results without the need to go through the complicated mathematics involved.
基金supported by the National Key R&D Program of China(Grant No.2016YFB0100100)supports from the National Natural Science Foundation of China(Grant No.51872305)。
文摘Lithium metal anode is regarded as the ultimate choice for next-generation energy storage systems,due to the lowest negative electrochemical potential and super high theoretical specific capacity.However,the growth of lithium dendrite during the cycling process is still one of the most critical bottlenecks for its application.In this work,a slurry-like hybrid electrolyte is proposed towards the application for lithium metal anode,which is composed of a liquid electrolyte part and a nanometric silane-Al2O3 particle part.The hybrid electrolyte shows high ionic conductivity(3.89×10-3 S cm-1 at 25℃)and lithium-ion transference number(0.88).Especially,the resistance of hybrid electrolyte decreases compared to that of liquid electrolyte,while the viscosity of hybrid electrolyte increases.It is demonstrated that the hybrid electrolyte can effectively suppress the growth of lithium dendrite.Stable cycling of Li/Li cells at a current density up to 1 mA cm-2 is possible.The hybrid electrolyte helps to uniform the lithium ion flux inside the battery and partly comes from the formation of a rigid and highly conductive hybrid interfacial layer on the surface of lithium metal.This work not only provides a fresh way to stabilize lithium metal anode but also sheds light on further research for electrolyte optimization and design of lithium metal battery system.
基金the National Natural Science Foundation of China(Grant No.51964022).
文摘In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is investigated.In particular,an Euler-Euler two-phase flow model is used to analyze the dynamics of both SiC particles and air.The numerical results show that by setting a certain reverse rotating speed of the rotating chamber,the accumulation of SiC particles on the wall can be improved,i.e.,their direction of motion in proximity to the wall can be changed and particles can be forced to re-join the granulation process.Experimental tests conducted to verify the reliability of the numerical findings,demonstrate that when the reverse rotating speed of the rotating chamber is 4 r/min,the sphericity of SiC particles in the rotating chamber is the highest and the fluidity is the best possible one.
