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| 1 | Effects of Nd^(3+)on the microstructure and magnetic properties of Ni-Zn ferrites显示文摘Ni0.4Zn0.6Fe2 ? 铁酸盐与 Nd2O3 的不同数量做了的 xNdxO4 (x = 0-0.07 ) 用标准陶器的技术被准备。样品单轴地被压并且在 1250D 的 | FAN Xiufeng REN Huiping ZHANG Yanghuan GUO Shihai WANG Xinlin | 2008 | Rare Metals2008,27,3: | 7 |
| 2 | Phase transformation,thermodynamics and kinetics property of Mg90Ce5RE5(RE=La,Ce,Nd)hydrogen storage alloys显示文摘The Mg90Ce5 RE5(RE=La,Ce,Nd)alloys were prepared by a vacuum induction furnace and their micro structure,phase transformation,thermodynamics and kinetics property were systematically studied by XRD,SEM,TEM,and PCT characterization methods.The result shows that the activated alloys are composed of Mg/MgH2 and corresponding REH2+x with nanoscale.The REH2+x grain with Ce and La or Nd functional group have lower nucleation potential barriers than CeH2+x grains as the nucleation location,thus improve the hydrogen absorption kinetics of these alloys among which the Mg90Ce5Nd5 alloy can absorb 90%of the hydrogen within 2 min at 320℃.In addition,the Mg90Ce10 alloy has the lowest activation energy with 103.2 kJ mol-1 and the fastest desorption kinetics,which can release 5 wt%of the hydrogen within 20 min at 320℃.This is a correlation with grain size and the in-suit formed CeH2.73/CeO2 interface.Moreover,the co-doping Ce and La or Nd can effectively disorganize the thermodynamic stability of Mg-based hydrogen storage alloys to a certain degree,but the dehydrogenation kinetics of that still is restricted by the recombination energy of hydrogen ions on the surface. | Hui Yong Shihai Guo Zeming Yuan Yan Qi Dongliang Zhao Yanghuan Zhang | 2020 | Journal of Materials Science & Technology2020,47,16: | 5 |
| 3 | Martensitic Transformation and Magnetic-Field-Induced Strain in Magnetic Shape Memory Alloy NiMnGa Melt-Spun Ribbon显示文摘A magnetic shape memory alloy with nonstoichiometric Ni5oMn27Ga23 was prepared by using melt-spinning technology. The martensitic transformation and the magnetic-field-induced strain (MFIS) of the polycrystalline melt-spun ribbon were investigated. The experimental results showed that the melt-spun ribbons underwent thermal-elastic martensitic transformation and reverse transformation in cooling and heating process and exhibited typical thermoelastic shape memory effect. However the start temperature for martensitic transformation decreased from 286 K for as-cast alloy to 254 K for as-quenched ribbon and Curie temperature remains approximately constant. A particular internal stress induced by melt-spinning resulted in the formation of a texture structure in the ribbons, which made the ribbons obtain larger martensitic transformation strain and MFIS. The internal stress was released substantially after annealing, which resulted in a decrease of MFIS of the ribbons. | Shihai GUO, Yanghuan ZHANG, Jianliang LI, Baiyun QUAN, Yan QI and Xinlin WANG Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081, China | 2005 | Journal of Materials Science & Technology2005,21,2: | 3 |
| 4 | Growth–climate response and drought reconstruction from tree-ring of Mongolian pine in Hulunbuir,Northeast China显示文摘Aims Drought affected by atmosphere–ocean cycle is a dominant factor influencing tree radial growth of sandy Mongolian pine(Pinus sylvestris var.mongolica)and regional vegetation dynamics in Hulunbuir,China.However,historical droughts and its correlations with tree radial growth and atmosphere–ocean cycle in this area have been little tested.Methods We developed tree-ring chronologies of Mongolian pine from Hulunbuir,Inner Mongolia,China and analyzed the correlations between tree-ring width index,the normalized difference vegetation index and Palmer drought severity index(PDSI),then developed a linear model to reconstruct the drought variability from 1829 to 2009.Long-term trends and its linkages with atmosphere–ocean cycle were performed by the power spectral,wavelet and teleconnection analysis.Important Findings The local moisture variations affected largely the regional vegetation dynamics and tree-ring growth of Mongolia pine in the forest–grassland transition.Using tree-ring width chronology of Mongolian pine,the reconstruction explains 49.2%of PDSI variance during their common data period(1951–2005).The reconstruction gives a broad-scale regional representation of PDSI in the Hulunbuir area,with drought occurrences in the 1850s,1900s,1920s,mid-1930s and at the turn of the 21st century.Comparisons with other treering drought reconstructions and historical records reveal some common drought periods and drying trends in recent decades at the northern margin zones of the East Asian summer monsoon(EASM).The drying trends in these zones occurred earlier than weakening of the EASM.A REDFIT spectral analysis shows significant peaks at 7.2,3.9,2.7–2.8,2.4 and 2.2 years with a 0.05 significance level,and 36.9,18.1 and 5.0 years with 0.1 significance level.Wavelet analysis also shows similar cycles.Drought variations in the study area significantly correlated with sea surface temperatures in the western tropical Pacific Ocean and middle and northern Indian Ocean,and the Pacific Decadal Oscillation and North Atlantic Oscillation.This suggests a possible linkage with the El Niño-Southern Oscillation,the EASM and the Westerlies. | Zhongjie Shi Lihong Xu Linshui Dong Jixi Gao Xiaohui Yang Shihai Lü Chaoyang Feng Aiyun Song Hao Guo Xiao Zhang | 2016 | Journal of Plant Ecology2016,9,1: | 3 |
| 5 | Phase evolution,hydrogen storage thermodynamics and kinetics of ternary Mg90Ce5Sm5 alloy显示文摘Greatly stable thermodynamics and sluggish kinetics impede the practical application of Mg-based hydrogen storage alloys.The modifications of composition and structure are important strategies in turning these hydrogen storage properties.In this study,Mg-based Mg90Ce5 Sm5 ternary alloy fabricated by vacuum induction melting was investigated to explore the performance and the reaction mechanism as hydrogen storage material by X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscopy(TEM) and pressure-composition isotherms(PCI) measurements.The results indicate that the Mg-based Mg90Ce5 Sm5 ternary alloy consists of two solid solution phases,including the major phases(Ce,Sm)5 Mg41 and the minor phases(Ce,Sm)Mg12.After hydrogen absorption,these phases transform into the MgH2 and(Ce,Sm)H2.73 phase,while after hydrogen desorption,the MgH2 transforms into the Mg phase,but the(Ce,Sm)H2.73 phases are not changed.The alloy has a reversible hydrogen capacity of about 5.5 wt% H2 and exhibits well isothermal hydrogen absorption kinetics.Activation energy of 106 kJ/mol was obtained from the hydrogen desorption data between 573 and 633 K,which also exhibits the enhanced kinetics compared with the pure MgH2 sample,as a result of bimetallic synergy catalysis function of(Ce,Sm)H2.73 phases.The rate of hydrogen desorption is controlled by the release and recombination of H2 from the Mg surface.Furthermore,the changes of enthalpy and entropy of hydrogen absorption/desorption were calculated to be-80.0 kJ/mol H2,-137.5 J/K/mol H2 and 81.2 kJ/mol H2,139.2 J/K/mol H2,respectively. | Hui Yong Shihai Guo Zeming Yuan Wei Zhang Yan Qi Dongliang Zhao Yanghuan Zhang | 2020 | Journal of Rare Earths2020,38,6: | 3 |
| 6 | Effects of substituting Ni with M (M=Cu, Al and Mn) on microstructures and electrochemical characteristics of La-Mg-Ni system (PuNi_3-type) electrode alloys显示文摘In order to improve the electrochemical cycle stability of La-Mg-Ni system (PuNi3-type) hydrogen storage alloy, Ni in the alloys was partially substituted by M (M=Cu, Al, Mn). A new La-Mg-Ni system electrode alloys La0.7Mg0.3Ni2.55-xCo0.45Mx (M=Cu, Al, Mn; x=0, 0.1) were prepared by casting and rapid quenching. The effects of element substitution and rapid quenching on the microstructures and electrochemical performances of the alloys were investigated. The results by XRD, SEM and TEM show that the alloys have a multiphase structure, including the (La, Mg)Ni3 phase, the LaNi5 phase and the LaNi2 phase. The rapid quenching and element substitution have an imperceptible influence on the phase compositions of the alloys, but both change the phase abundance of the alloys. The rapid quenching significantly improves the composition homogeneity of the alloys and markedly decreases the grain size of the alloys. The Cu substitution promotes the formation of an amorphous phase in the as-quenched alloy, and a reversal result by the Al substitution. The electrochemical measurement indicates that the element substitution decreases the discharge capacity of the alloys, whereas it obviously improves the cycle stability of the alloys. The positive influence of element substitution on the cycle life of the alloys is in sequence Al>Cu>Mn, and negative influence on the discharge capacity is in sequence Al>Mn>Cu. The rapid quenching significantly enhances the cycle stability of the alloys, but it leads to a different extent decrease of the discharge capacity of the alloys. | ZHANG Yanghuan ZHAO Dongliang DONG Xiaoping REN Huiping GUO Shihai WANG Xinlin | 2006 | Rare Metals2006,25,z1: | 2 |
| 7 | 3D bioprinting of integral ADSCs-NO hydrogel scaffolds to promote severe burn wound healing显示文摘Severe burns are challenging to heal and result in significant death throughout the world.Adiposederived mesenchymal stem cells(ADSCs)have emerged as a promising treatment for fullthickness burn healing but are impeded by their low viability and efficiency after grafting in vivo.Nitric oxide(NO)is beneficial in promoting stem cell bioactivity,but whether it can function effectively in vivo is still largely unknown.In this study,we bioprinted an efficient biological scaffold loaded with ADSCs and NO(3D-ADSCs/NO)to evaluate its biological efficacy in promoting severe burn wound healing.The integral 3D-ADSCs/NO hydrogel scaffolds were constructed via 3D bioprinting.Our results shown that 3D-ADSCs/NO can enhance the migration and angiogenesis of Human Umbilical Vein Endothelial Cells(HUVECs).Burn wound healing experiments in mice revealed that 3D-ADSCs/NO accelerated the wound healing by promoting faster epithelialization and collagen deposition.Notably,immunohistochemistry of CD31 suggested an increase in neovascularization,supported by the upregulation of vascular endothelial growth factor(VEGF)mRNA in ADSCs in the 3D biosystem.These findings indicated that 3D-ADSC/NO hydrogel scaffold can promote severe burn wound healing through increased neovascularization via the VEGF signalling pathway.This scaffold may be considered a promising strategy for healing severe burns. | Yu Wu Tangzhao Liang Ying Hu Shihai Jiang Yuansen Luo Chang Liu Guo Wang Jing Zhang Tao Xu Lei Zhu | 2021 | Regenerative Biomaterials2021,8,3: | 2 |
| 8 | Gaseous hydrogen storage properties of Mg-Y-Ni-Cu alloys prepared by melt spinning显示文摘For purpose of promoting the hydrogen absorption and desorption thermodynamics and kinetics properties of Mg-Ni-based alloys, partially substituting Y and Cu for Mg and Ni respectively and melt spinning technique were applied for getting Mg25-xYxNi9 Cu(χ = 0-7) alloys. Their microstructures and phases were characterized with the help of X-ray diffraction and transmission electron microscopy. Their hydrogen absorbing and desorbing properties were tested by a Sievert apparatus, DSC, and TGA, which were connected with a H2 detector. In order to estimate the dehydrogenation activation energy of alloy hydride, both Arrhenius and Kissinger methods were applied for calculation. It is found that their hydriding kinetics notably declines, however, their hydrogen desorption kinetics conspicuously improves, with spinning rate and Y content increasing. Their hydrogen desorption activation energy markedly decreases under the same constraint, and it is found that melt spinning and Y substituting Mg improve the real driving force for dehydrogenation. As for the tendency of hydrogen absorption capacity,it presents an elevation firstly and soon after a decline with the rising of spinning rate, however, it always lowers with Y content growing. With Y content and spinning rate increasing, their thermodynamic parameters(△H and △S absolute values) visibly decrease, and the starting hydrogen desorption temperatures of alloy hydrides obviously lower. | Yanghuan Zhang Yaqin Li Wei Zhang Zeming Yuan Zhonghui Hou Yan Qi Shihai Guo | 2019 | Journal of Rare Earths2019,37,7: | 2 |
| 9 | Hydrogen Storage Kinetics of Nanocrystalline and Amorphous LaMg_(12)-Type Alloy–Ni Composites Synthesized by Mechanical Milling显示文摘The nanocrystalline and amorphous LaMg_(11)Ni + x wt% Ni(x = 100, 200) composites were synthesized by the mechanical milling, and their gaseous and electrochemical hydrogen storage kinetics performance were systematically investigated. The results indicate that the as-milled composites exhibit excellent hydrogen storage kinetic performances, and increasing Ni content significantly facilitates the improvement of the hydrogen storage kinetics properties of the composites. The gaseous and electrochemical hydrogen storage kinetics of the composites reaches a maximum value with the variation of milling time.Increasing Ni content and milling time both make the hydrogen desorption activation energy lower, which are responsible for the enhancement in the hydrogen storage kinetics properties of the composites. The diffusion coefficient of hydrogen atom and activation enthalpy of charge transfer on the surface of the as-milled composites were also calculated, which are considered to be the dominated factors for the electrochemical high rate discharge ability. | Yanghuan Zhang Baowei Li Huiping Ren Tai Yang Shihai Guo Yan Qi Dongliang Zhao | 2016 | Journal of Materials Science & Technology2016,32,3: | 1 |
| 10 | Structure and hydrogen storage characteristics of as-spun Mg-Y-Ni-Cu alloys显示文摘Experimental alloys with compositions of Mg(25-x)YxNi9Cu(x=0,1,3,5,7)have been successfully prepared through melt spinning method.The phase compositions and microstructures were measured by X-Ray diffraction(XRD)and high-resolution transmission electron microscopy(HRTEM).The de-/hydrogenation properties were measured by utilizing Sievert apparatus,differential scanning calorimetry(DSC)and thermal gravimetric analyzer(TGA)connected with a H2 detector.The Arrhenius and Kissinger methods were adopted to calculate their dehydrogenation activation energies.The results show that hydrogen absorption kinetics of the alloys notably decline while their hydrogen desorption kinetics conspicuously improve with spinning rate increasing.The dehydrogenation activation energy markedly decreases with spinning rate increasing,which makes the hydrogen desorption kinetics improve.The thermodynamic parameters(H and S absolute values)clearly decrease with spinning rate increasing.The hydrogen absorption capacity exhibits different trends with spinning rate rising.Specifically,hydrogen absorption capacity increases at the beginning and declines later for Y1 alloy,but that of Y7 alloy always decreases with spinning rate growing. | Yanghuan Zhang Pengpeng Wang Zhonghui Hou Zeming Yuan Yan Qi Shihai Guo | 2019 | Journal of Materials Science & Technology2019,35,8: | 1 |
| 11 | Structure and Electrochemical Hydrogen Storage Properties of as-Milled Mg-Ce-Ni-Al-Based Alloys显示文摘At room temperature,crystalline Mg-based alloys,including Mg2 Ni,MgNi,REMg12 and La2 Mg17,have been proved with weak electrochemical hydrogen storage performances.For improving their electrochemical property,the Mg is partially substituted by Ce in Mg-Ni-based alloys and the surface modification treatment is performed by mechanical coating Ni.Mechanical milling is utilized to synthesize the amorphous and nanocrystalline Mg1-xCexNi0.9Al0.1(x=0,0.02,0.04,0.06,0.08)+50 wt%Ni hydrogen storage alloys.The effects made by Ce substitution and mechanical milling on the electrochemical hydrogen storage property and structure have been analyzed.It shows that the as-milled alloys electrochemically absorb and desorb hydrogen well at room temperature.The as-milled alloys,without any activation,can reach their maximal discharge capacities during first cycling.The maximal value of the 30-h-milled alloy depending on Ce content is 578.4 mAh/g,while that of the x=0.08 alloy always grows when prolonging milling duration.The maximal discharge capacity augments from337.4 to 521.2 mAh/g when milling duration grows from 5 to 30 h.The cycle stability grows with increasing Ce content and milling duration.Concretely,the S100 value augments from 55 to 82%for the alloy milled for 30 h with Ce content rising from 0 to 0.08 and from 66 to 82%when milling the x=0.08 alloy mechanically from 5 to 30 h.The alloys’electrochemical dynamics parameters were measured as well which have maximum values depending on Ce content and keep growing up with milling duration extending. | Yanghuan Zhang Zhenyang Li Wei Zhang Wengang Bu Yan Qi Shihai Guo | 2020 | Acta Metallurgica Sinica(English Letters)2020,33,5: | 1 |
| 12 | Structure and electrochemical hydrogen storage behaviors of Mg-Ce-Ni-Al-based alloys prepared by mechanical milling显示文摘The influences of milling time and Ce content on the electrochemical property and micro structure of asmilled Mg1-xCexNi0.9Al0.1(x=0,0.02,0.04,0.06,0.08)+50 wt%Ni alloys were investigated systematically.The as-milled alloys have an outstanding activation property.The cycle stability conspicuously grows up with milling time and Ce proportion increasing.The capacity retention rate at 100 th cycle of x=0.02 alloy augments from 47% to 63% when prolonging milling time from 5 to 30 h and it grows from55% to 82% for the 30 h milled alloy with Ce content growing from 0 to 0.08.The discharge capacity of x=0.02 alloy grows up invariably with milling time prolonging,while that of the 30 h milled alloys has the maximal value of 578.4 mAh/g with Ce content increasing.Moreover,the electrochemical kinetic properties of alloys significantly improve with milling duration extending,while they have the maximal values with Ce proportion varying. | Yanghuan Zhang Pengpeng Wang Wei Zhang Wengang Bu Yan Qi Shihai Guo | 2020 | Journal of Rare Earths2020,38,10: | 1 |
| 13 | Self-interference cancellation for cooperative jamming communications with nonideal alignment and channel equalization显示文摘For the security of wireless communications, cooperative jamming can be used to intentionally degrade the signal-to-noise ratios received by eavesdroppers. Unfortunately, this jamming may also propagate to the legal receiver and then become a harmful self-interference(SI), which should be cancelled for reliable detection of the desired signal. In this paper, by comprehensively considering nonideal time-frequency alignment and channel equalization, SI-cancellation capability is investigated for the additive white Gaussian noise channel. Theoretical and simulation results demonstrated that the impact of the frequency alignment error is more serious than that of the time alignment and channel equalization errors. Moreover, it is illustrated that weaker SI power can tolerate a larger range of those nonidealities. | Wenbo GUO Yimin HE Hongzhi ZHAO Shihai SHAO Youxi TANG | 2021 | Science China(Information Sciences)2021,64,11: | 1 |
| 14 | The hy- drogenation and dehydrogenation hehaviours of Mg20-xLaxNi10 (x = 0 - 6 )alloys prepared by casting and rapid quenching显示文摘 | Zhang Yanghuan Zhao Dongliang Guo Shihai | 2009 | J Alloys Compd2009,476,: | 1 |
| 15 | Improving the intrinsic electronic conductivity of NiMo0_(4) anodes by phosphorous doping for high lithium storage显示文摘Heteroatom doping is one of the most promising strategies toward regulating intrinsically sluggish electronic conductivity and kinetic reaction of transition metal oxides for enhancing their lithium storage.Herein,we designed phosphorus-doped NiMo0_(4) nanorods(P-NiMo0_(4))by using a facile hydrothermal method and subsequent low-temperature phosphorization treatment.Phosphorus doping played an indispensable role in significantly improving electronic conductivity and the Li+diffusion kinetics of NiMo0_(4) materials.Experimental investigation and density functional theory calculation demonstrated that phosphorus doping can expand the interplanar spacing and alter electronic structures of NiMo0_(4) nanorods.Meanwhile,the introduced phosphorus dopant can generate some oxygen vacancies on the surface of NiMo0_(4),which can accelerate Li+diffusion kinetics and provide more active site for lithium storage.As excepted,P-NiMo0_(4) electrode delivered a high specific capacity(1,130 mA·g^(-1) at 100 mA·g^(-1) after 100 cycles),outstanding cycling durability(945 mA·g^(-1) at 500 mA·g^(-1) over 200 cycles),and impressive rate performance(640 mA·g^(-1)at 2,000mA·g^(-1))for lithium ion batteries(LIBs).This work could provide a potential strategy for improving intrinsic conductivity of transition metal oxides as high-performance anodes for LIBs. | Luchao Yue Chaoqun Ma Shihai Yan Zhenguo Wu Wenxi Zhao Qian Liu(ISl) Yonglan Luo Benhe Zhong Fang Zhang Yang Liu Abdulmohsen AN Alshehri Khalid Ahmed Alzahrani Xiaodong Guo Xuping Sun | 2022 | Nano Research2022,15,1: | 1 |
| 16 | The Three-Stage Model Based on Strain Strength Distribution for the Tensile Failure Process of Rock and Concrete Materials显示文摘A three-stage model is introduced to describe the tensile failure process of rock and concrete materials.Failure of the material is defined to contain three stages in the model,which include elastic deformation stage,body damage stage and localization damage stage.The failure mode change from uniform body damage to localization damage is expressed.The heterogeneity of material is described with strain strength distribution.The fracture factor and intact factor,defined as the distribution function of strain strength,are used to express the fracture state in the failure process.And the distributive parameters can be determined through the experimental stress-strain curve. | Rukun Guo Shihai Li Dong Zhou | 2016 | Acta Mechanica Solida Sinica2016,29,5: | 0 |
| 17 | Highly Improved Electrochemical Performances of the Nanocrystalline and Amorphous Mg_2Ni-type Alloys by Substituting Ni with M (M=Cu,Co,Mn)显示文摘The element Ni in the Mg_2Ni alloy is partially substituted by M(M = Cu, Co, Mn) in order to ameliorate the electrochemical hydrogen storage performances of Mg_2Ni-type electrode alloys. The nanocrystalline and amorphous Mg_(20)Ni_(10-x)M_x(M = None, Cu, Co, Mn; x = 0-4) alloys were prepared by melt spinning. The effects of the M(M = Cu, Co, Mn) content on the structures and electrochemical hydrogen storage characteristics of the as-cast and spun alloys were comparatively studied. The analyses by XRD, SEM and HRTEM reveal that all the as-cast alloys have a major phase of Mg_2Ni but the M(M = Co, Mn) substitution brings on the formation of some secondary phases, MgCo_2 and Mg for the(M = Co) alloy, and Mn Ni and Mg for the(M = Mn) alloy. Besides, the as-spun(M = None, Cu) alloys display an entirely nanocrystalline structure, whereas the as-spun(M = Co, Mn) alloys hold a nanocrystalline/amorphous structure, suggesting that the substitution of M(M = Co, Mn) for Ni facilitates the glass formation in the Mg_2Ni-type alloys. The electrochemical measurements indicate that the variation of M(M = Cu, Co, Mn) content engenders an obvious effect on the electrochemical performances of the as-cast and spun alloys. To be specific, the cyclic stabilities of the alloys augment monotonously with increasing M(M = Cu, Co, Mn) content, and the capacity retaining rate(S20) is in an order of(M = Cu) >(M = Co) >(M = Mn) >(M = None) for x≤1 but changes to(M = Co) >(M = Mn) >(M = Cu) >(M = None) for x≥2. The discharge capacities of the as-cast and spun alloys always grow with the rising of M(M = Co, Mn) content but first mount up and then go down with increasing M(M = Cu) content. Whatever the M content is, the discharge capacities are in sequence:(M = Co) >(M = Mn) >(M = Cu) >(M = None). The high rate discharge abilities(HRDs) of all the alloys grow clearly with rising M(M = Cu, Co) content except for(M = Mn) alloy, whose HRD has a maximum value with varying M(M = Mn) content. Furthermore, for the as-cast alloys, the HRD is in order of(M = Co) >(M = Mn) >(M = Cu) >(M = None), while for the as-spun(20 m·s^(-1)) alloys, it changes from(M = Co) >(M = Mn) >(M = Cu) >(M = None) for x = 1 to(M = Cu) >(M = Co) >(M = None) >(M = Mn) for x = 4. | 张羊换 YUAN Zeming YANG Tai ZHAI Tinging LIU Zhuocheng GUO Shihai | 2017 | Journal of Wuhan University of Technology(Materials Science)2017,32,3: | 0 |
| 18 | A comparison study of hydrogen storage properties of as-milled Sm_5Mg_(41) alloy catalyzed by CoS_2 and MoS_2 nano-particles显示文摘The influences of the catalysts of CoS_2 and MoS_2 nano-particles on microstructure and hydrogen storage behaviors of as-milled Sm_5Mg_(41) alloy have been compared in this work. The Sm_5Mg_(41)+ 5 wt.% M(M = CoS_2, MoS_2) alloys were prepared by milling the mechanical ground as-cast Sm_5Mg_(41) alloy powders(particle size ≤ 75 μm) with 5 wt.% CoS_2 or MoS_2 nano-particles(particle size ≤ 30 nm), respectively. The results demonstrate that the CoS_2 and MoS_2 nanoparticles are embedded into the alloy surface, which is nanostructure containing some crystal defects, such as dislocation, grain boundary and twin etc. Those microstructures play a beneficial role in reducing the total potential barrier that the hydrogen absorption or desorption reactions must overcome, hence improving the hydrogen storage kinetics of the alloys.The as-milled alloys are composed of Sm_5Mg_(41) and SmMg_3 phases, and ball milling refines their crystal grains. The MgH_2 and Sm_3 H_7 phases appear after hydrogenation, while Mg and Sm_3 H_7 phases exist after dehydrogenation. The dehydriding activation energy of M = CoS_2 and MoS_2 alloys are 101.67 and 68.25 kJ/mol H_2 respectively. The initial hydrogen desorption of M = CoS_2 and MoS_2 alloys are 252.9?C and 247.8?C. The hydrogenation and dehydrogenation enthalpy changes of M = MoS_2 alloy are a little smaller than that of M = CoS_2 alloy. Therefore, the catalyst MoS_2 can improve the as-milled Sm_5Mg_(41) alloy in hydrogen storage property more effectively than CoS_2. | Zeming Yuan Bangwen Zhang Yanghuan Zhang Shihai Guo Xiaoping Dong Dongliang Zhao | 2018 | Journal of Materials Science & Technology2018,34,10: | 0 |
| 19 | Multifunctional peptide conjugated amphiphilic cationic copolymer for enhancing ECs targeting, penetrating and nuclear accumulation显示文摘Gene therapy has drawn great attention in the treatments of many diseases,especially for cardiovascular diseases.However,the development of gene carriers with low cytotoxicity and multitargeting function is still a challenge.Herein,the multitargeting REDV-G-TATG-NLS peptide was conjugated to amphiphilic cationic copolymer poly(e-caprolactone-co-3(S)-methyl-morpho-line-2,5-dione)-g-polyethyleneimine(PCLMD-g-PEI)via a heterobifunctional orthopyridyl disulfde-poly(ethylene glycol)-N-hydroxysuccinimide(OPSS-PEG-NHS)linker to prepare PCLMD-g-PEI-PEG-REDV-G-TAT-G-NLS copolymers with the aim to develop the gene carriers with low cytotoxicity and high transfection efficiency.The multitargeting micelles were prepared from PCLMD-g-PEI-PEG-REDV-G-TAT-G-NLS copolymers by self-assembly method and used to load pEGFP-ZNF580 plasmids(pDNA)to form gene complexes for enhancing the proliferation and migration of endothelial cells(ECs).The loading pDNA capacity was proved by agarose gel electrophoresis assay.These multitargeting gene com-plexes exhibited low cytotoxicity by 3-(4,-dimethylthia-zol-2-yl)-2,5-diphenyltetrazolium bromide assay.The high internalization efficiency of these gene complexes was confirmed by flow cytometry.The results of in vitro transfection demonstrated that these multitargeting gene complexes possessed relatively high transfection effi-ciency.The rapid migration of ECs transfected by these gene complexes was verified by wound healing assay.Owing to ECs-targeting ability,cell-penetrating ability and nuclear targeting capacity of REDV-G-TAT-G-NLS pep-tide,the multitargeting polycationic gene carrier with low cytotoxicity and high transfection efficiency has great potential in gene therapy. | Xinghong Duo Lingchuang Bai Jun Wang Jintang Guo Xiangkui Ren Shihai Xia Wencheng Zhang Abraham Domb Yakai Feng | 2020 | Frontiers of Chemical Science and Engineering2020,14,5: | 0 |
| 20 | A comparison study of hydrogen storage performances of SmMg_(11)Ni alloys prepared by melt spinning and ball milling显示文摘The melt spinning(MS) and ball milling(BM) technologies are thought to be efficient to prepare nanostructured Mg and Mg-based alloys for improving their hydrogen storage performances. In this paper, two technologies, viz. melt spinning and ball milling, were employed to fabricate the SmMg_(11)Ni alloy. The structure and hydrogen storage performance of these two kinds of alloys were researched in detail. The results reveal that the as-spun and milled alloys both contain nanocrystalline and amorphous structures. By means of the measurement of PCT curves, the thermodynamic parameters of the alloys prepared by MS and BM are ΔN_(Ms)(des) = 82.51 kJ/mol and ΔH_(BM)(des) = 81.68 kJ/mol, respectively, viz.ΔH_(MS)(des) > ΔH_(BM)(des). The as-milled alloy shows a larger hydrogen absorption capacity as compared with the as-spun one. The as-milled alloy exhibits lower onset hydrogen desorption temperature than the as-spun one. As to the as-milled and spun alloys, the onset hydrogen desorption temperatures are557.6 and 565.3 K, respectively. Additionally, the as-milled alloy shows a superior hydrogen desorption property than the as-spun one. On the basis of time that required by desorbing hydrogen of 3 wt% H_2, the as-milled alloy needs 1488.574,390 and 192 s corresponding to hydrogen desorption temperatures 593,613,633 and 653 K, while the as-spun alloy needs 3600,1020,778 and 306 s corresponding to the same temperatures. The dehydrogenation activation energies of the as-milled and spun alloys are 100.31 and105.56 kJ/mol, respectively, the difference of which is responsible for the much faster dehydriding rate of the as-milled alloy. | Yanghuan Zhang Meng Ji Zeming Yuan Jingliang Gao Yan Qi Xiaoping Dong Shihai Guo | 2018 | Journal of Rare Earths2018,36,4: | 0 |