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Simultaneous growth of carbon nanotubes on inner/outer surfaces of porous polyhedra:Advanced sulfur hosts for lithium-sulfur batteries

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Nano Research 2018年第12期11卷 6155-6166页

作者： Hengyi Lu Chao Zhang Youfang Zhang Yunpeng Huang Mingkai Liu Tianxi Liu State Key Laboratory for Modification of Chemical Iqbers and Polymer Materials College of Materials Science and EngineeringInnovation Center for.Textile Science and TechnologyDonghua University2999North Renmin RoadShanghai201620China State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan University220Handan RoadShanghai 200433China School of Chemistry and Chemical Engineering Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional MaterialsJiangsu Normal UniversityXuzhou 221116China

Metal-organic framework (MOF)-derived functional carbon matrices have recently attracted considerable attention as energy-storage materials. However, the development of MOF-derived carbon materials with hierarchical structures, capable of thoroughly preventing the “shuttling᾿of polysulfides, is still a major challenge. Herein, we synthesized cobalt nanoparticle-containing porous carbon polyhedra with in situ grown N-doped carbon nanotube (CNT) backbone (NCCNT-Co), using zeolitic imidazolate framework-67 (ZIF-67) as starting material. The obtained NCCNT-Co, with interconnected N-doped CNTs on both inner and outer surfaces, possesses an integrated conductive network, which can further accelerate the transport of electrons/ions inside the whole sulfur cathode. The mesoporous structure derived from the ZIF-67 matrix and the densely immobilized CNTs, coupled with the homogeneously doped N atoms and Co nanoparticles, can efficiently trap lithium polysulfides (LiPSs) by physical confinement and chemical interactions. Furthermore, the hierarchical structure of the porous carbon polyhedra enables a high sulfur loading of up to 76 wt.% and can also buffer the volume changes of active sulfur during the lithiation process. As a result, the NCCNT-Co-S cathode delivers a high initial specific capacity of 1,300 mAh·g−1 at 0.1 C, along with a high capacity of 860 mAh·g−1 after 500 cycles at 1 C, with an extremely low capacity decay of 0.024% per cycle.

关键词： zeolitic imidazolate framework-67 (ZIF-67) carbon nanotubes in situ growth Li-S batteries

Prediction model for austenite grains growth during reheating process in Ti micro-alloyed cast steel by coupling precipitates dissolution and coarsening behavior

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Journal of Iron and Steel Research International 2019年第2期26卷 162-172页

作者： Tao Liu Mu-jun Long Wen-jie He Deng-fu Chen Zhi-hua Dong Xian-guang Zhang Hua-mei Duan State Key Laboratory of Coal Mine Disaster Dynamics and Control College of Materials Science and EngineeringChongqing UniversityChongqing 400030China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400030China Applied Materials Physics.Department of Materials Science and Engineering KTH-Royal Institute of TechnologyStockholm 10044Sweden Institute for Materials Research Tohoku UniversitySendai 980-8577Japan

A combined model to predict austenite grains growth of titanium micro-alloyed as-cast steel during reheating process was *** model invoIves the behaviors of austenite grains growth in continuous heating process and isothermal soaking process,and the variation of boundary pinning efficiency caused by the dissolution and coarsening kinetics of sec on d-phase particles was also con sidered into the ***,the experimental verificatio ns were performed to examine the prediction power of the *** results revealed that the mean austenite grains size increased with the increase in reheating temperature and soaking time,and the coarsening temperature of austenite grains growth was 1423 K under the current titanium *** addition,the reliability of the predicted results in continuous heating process was validated by continuous heating ***,an optimal regression expression of austenite grains growth in isothermal soaking process was obtained based on the experimental *** compared results indicated that the combined model in conjunction with precipitates dissolution and coarsening kinetics had good reliability and accuracy to predict the austenite grains growth of titanium micro-alloyed casting steel during reheating process.

关键词： Austenite grains growth Reheating process Precipitate dissolution Precipitate coarsening Prediction model

Effect of growth temperature of GaAsxSb1-x metamorphic buffer layer on electron mobility of InAs/AlSb heterostructures grown on Si substrate

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Chinese Physics B 2019年第11期28卷 364-369页

作者： Jing Zhang Hong-Liang Lv Hai-Qiao Ni Shi-Zheng Yang Xiao-Ran Cui Zhi-Chuan Niu Yi-Men Zhang Yu-Ming Zhang School of Microelectronics Xidian University and the State Key Discipline Laboratory of Wide Band Gap Semiconductor TechnologyXi’an 710071China State Key Laboratory for Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

The InAs/AlSb heterostructures with step-graded GaAsxSb1-x metamorphic buffer layers grown on Si substrates by molecular beam epitaxy are studied. The step-graded GaAsxSb1-x metamorphic buffer layers are used to relax the strain and block defects at each interface of the layers. Meanwhile, adding Sb to GaAs is also beneficial to suppressing the formation of dislocations in the subsequent materials. The influences of the growth temperature of the step-graded GaAsxSb1-x metamorphic buffer layer on the electron mobility and surface topography are investigated for a series of samples. Based on the atomic force microscopy（AFM）, high resolution x-ray diffraction（HRXRD）, reciprocal space map（RSM）, and Hall measurements, the crystal quality and composition of GaAsxSb1-x layer are seen to strongly depend on growth temperature while keeping the Ga growth rate and V/III ratio constant. The results show that the highest electron mobility is 10270 cm2/V·s and the roughness is 4.3 nm for the step-graded GaAsxSb1-x metamorphic buffer layer grown at a temperature of 410℃.

关键词： Si sticking coefficients growth temperature GaAsxSb1-x metamorphic buffer

van der Waals epitaxial growth of ultrathin metallic NiSe nanosheets on WSe2 as high performance contacts for WSe2 transistors

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Nano Research 2019年第7期12卷 1683-1689页

作者： Bei Zhao Weiqi Dang Xiangdong Yang Jia Li Haihong Bao Kai Wang Jun Luo Zhengwei Zhang Bo Li Haipeng Xie Yuan Liu Xidong Duan Hunan Key Laboratory of Two-Dimensional Materials State Key Laboratory for Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China School of Physics and Electronics Hunan UniversityChangsha 410082China Center for Electron Microscopy Institute for New Energy Materials and Low-Carbon Technologies School of Materials Tianjin University of TechnologyTianjin 300384China Hunan Key Laboratory of Super-microstructure and Ultrafast Process College of Physics and ElectronicsCentral South UniversityChangsha 410083China

A prerequisite for widespread applications of atomically thin transition metal dichalcogenides in future electronics is to achieve reliable electrical contacts,which is of considerable challenge due to the difficulties in selectively doping and inevitable physical damages of these atomically thin materials during typical metal integration ***,we report the in situ growth of ultrathin metallic NiSe single crystals on WSe2 in which the metallic NiSe nanosheets function as the contact electrodes to WSe2,creating an interface that is essentially free from chemical *** NiSe/WSe2 heterostructures also exhibit well-aligned lattice orientation between the two layers,forming a periodic Moire *** transport studies demonstrate that the NiSe nanosheets exhibit an excellent metallic feature,as evidenced by the extra-high electrical conductivity of up to 1.6×10^6 *** WSe2 transistors with the NiSe contact show field-effect mobilities (/vFe) more than double that with Cr/Au *** study demonstrates an effective pathway to achieve reliable electrical contacts to the atomically thin 2D materials,and maybe readily extended for fabricating 2D/2D low-resistance contacts for a variety of transition metal dichalcogenides.

关键词： in situ growth nonlayered NiSe nanosheets Schottky barrier metal-semiconductor junctions chemical vapor deposition

Comparative Investigation on Step-cycle Tensile Behaviors of Two Bimodal Pipe-grade Polyethylene with Different Slow Crack growth Resistance

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Chinese Journal of Polymer Science 2020年第6期38卷 611-619页

作者： Yan-Qin Huang Qing-Long Zhang Xiao-Ying Lu Yi-Bin Gong Hao Zhou Jia-Chun Feng StoteKey Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai200433China Laboratory for Synthetic Resin Research PetroChina Petrochemical Research InstituteBeijing W0083China Institute ofDushanzi Petrochemical Corporation PetroChina Company LimitedDushanzi 833699China

In this work,step-cycle tensile behavior of two bimodal polyethylene(PE)materials,a PEI 00 grade pipe material,XS10,and a PEI 00-RC(Resistant Crack)grade pipe material,XSC50,was comparatively *** decomposing the strain into a recoverable part and an unrecoverable part,it was found that the deformation recovery capability of XSC50 during stretching was larger than that of *** evolution characterized by in situ synchrotron small angle X-ray scattering indicated that the fragmentation of initial crystals in XSC50 occurred at lower strain than in *** that XSC50 had relatively small lamellar thickness and similar crystallinity to XS10,we speculated that the larger deformation recovery capability of XSC50 during stretching probably derived from stronger entangled amorphous region caused by larger density of tie molecules and entanglements,which were usually regarded to have a significant influence on the slow crack growth(SCG)resistance of PE *** expected,the experimental result of strain hardening modulus test suggested that the deformation recovery capability during stretching was positively correlated with the SCG resistance for XS10 and XSC50 used in this *** step-cycle tensile test had the potential to be developed into a supplement for comparison of SCG resistance of PE materials.

关键词： Polyethylene Step-cycle tensile test Deformation recovery Slow crack growth resistance

Primary dendrite growth kinetics and rapid solidification mechanism of highly undercooled Ti-Al alloys

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Journal of Materials Science & Technology 2020年第5期40卷 47-53页

作者： Z.C.Luo H.P.Wang Department of Applied Physics Northwestern Polytechnical UniversityXi’an 710072China

The rapid solidification processes of undercooled Ti-(47,50,54)at.%Al alloys were investigated by electromagnetic levitation(EML)method combined with a high-speed photoelectric *** maximum undercoolings of the three liquid alloys were 376 K,352 K and 316 K,*** processes corresponding to the primary dendrite growth and subsequent phase transition were recorded at various *** primary dendrite growth velocity V meets a double exponential relationship with the undercooling ***,a novel formula with physical meaning is proposed to explain that the more ordered liquid metal atoms accelerate the primary dendrite *** recalescences are found at all undercoolings for Ti-47 at.%Al alloy and at high undercoolings for Ti-50 at.%Al *** microstructures of solidified Ti-47 at.%Al alloys successively appear as coarse lamellar dendrites and finally evolve to refined parallel lamellar dendrites with the increasing *** T rises,the microstructures of solidified Ti-50 at.%Al alloys appear from coarse primary dendrites and interdendritic dendrites to refined lamellar *** the process from low undercooling to high undercooling,the primary phase of undercooled Ti-54 at.%Al alloys changes from r-Ti(r)to r-TiAl(r)and the microstructures of solidified alloys evolve from spherical primary dendrites and matrix phases to cellular dendrite ***,for the Ti-(47,50)at.%Al,the transformation temperature of metastable intermediateγphase decreases with the increase of ***,the microhardness of the three solidified alloys reaches the maximum when the undercoolings are 185 K,270 K and 316 K,respectively.

关键词： Electromagnetic levitation Rapid solidification Dendrite growth Microstructure Microhardness

Experimental study of effect of post processing on fracture toughness and fatigue crack growth performance of selective laser melting Ti-6Al-4V

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Chinese Journal of Aeronautics 2019年第10期32卷 2383-2393页

作者： Haiying ZHANG Dengke DONG Shaopu SU An CHEN Aircraft Strength Research Institute

For Ti-6Al-4V,a titanium alloy increasingly used in aerospace structure,selective laser melting(SLM)is an attractive additive manufacturing technology,which is attributed to its complex construction capability with high accuracy and good surface *** order to obtain qualified mechanical properties,SLM parameters and post processing should be tailored for diverse service *** toughness and fatigue crack growth(FCG)behavior are critical characteristics for damage tolerance evaluation of such metallic structures,and they are affected by post processing technologies *** objective of this study is to obtain the fracture toughness and fatigue crack growth behavior of Ti-6Al-4V manufactured by SLM,and to evaluate the influence of post-SLM thermomechanical treatment and surface *** toughness and FCG tests were performed for SLM Ti-6Al-4V in three types of post processing status:as-built,heat treated and hot isostatically pressed(HIPed),*** with as-built and machined surface were *** microstructure and fractography were analyzed as well in order to investigate the relevance among manufacture process,microstructure and mechanical *** results demonstrate that as-built SLM Ti-6Al-4V presents poor ductility and FCG behavior due to martensitic microstructure and residual *** heat treatment and hot isostatic pressing improve the plane-stress fracture toughness and FCG performance considerably,while surface machining shows slight effect.

关键词： Fracture toughness Fatigue crack growth Heat treatment Selective laser melting Surface roughness

The LRXs-RALFs-FER module controls plant growth and salt stress responses by modulating multiple plant hormones

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National Science Review 2021年第1期8卷 40-55页

作者： Chunzhao Zhao Wei Jiang Omar Zayed Xin Liu Kai Tang Wenfeng Nie Yali Li Shaojun Xie Yuan Li Tiandan Long Linlin Liu Yingfang Zhu Yang Zhao Jian-Kang Zhu Shanghai Center for Plant Stress Biology and Center of Excellence in Molecular Plant Sciences Chinese Academy of Sciences Department of Horticulture and Landscape Architecture Purdue University Key laboratory of Plant Stress Biology School of Life SciencesHenan University National Center for Soybean Improvement Key Laboratory of Biology and Genetics and Breeding for Soybean Ministry of Agriculture State Key Laboratory of Crop Genetics and Germplasm Enhancement Nanjing Agricultural University Genetics Department Faculty of AgricultureMenofia University University of the Chinese Academy of Sciences State Key Laboratory of Plant Physiology and Biochemistry College of Biological SciencesChina Agricultural University State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China Sichuan Agricultural University

Salt stress is a major environmental factor limiting plant growth and productivity. We recently discovered an important new salt tolerance pathway, where the cell wall leucine-rich repeat extensins LRX3/4/5, the RAPID ALKALINIZATION FACTOR (RALF) peptides RALF22/23 and receptor-like kinase FERONIA(FER) function as a module to simultaneously regulate plant growth and salt stress tolerance. However, the intracellular signaling pathways that are regulated by the extracellular LRX3/4/5-RALF22/23-FER module to coordinate growth, cell wall integrity and salt stress responses are still unknown. Here, we report that the LRX3/4/5-RALF22/23-FER module negatively regulates the levels of jasmonic acid (JA), salicylic acid(SA) and abscisic acid (ABA). Blocking JA pathway rescues the dwarf phenotype of the lrx345 and fer-4mutants, while disruption of ABA biosynthesis suppresses the salt-hypersensitivity of these mutants. Many salt stress-responsive genes display abnormal expression patterns in the lrx345 and fer-4 mutants, as well as in the wild type plants treated with epigallocatechin gallate (EGCG), an inhibitor of pectin methylesterases,suggesting cell wall integrity as a critical factor that determines the expression pattern of stress-responsive genes. Production of reactive oxygen species (ROS) is constitutively increased in the lrx345 and fer-4mutants, and inhibition of ROS accumulation suppresses the salt-hypersensitivity of these ***, our work provides strong evidence that the LRX3/4/5-RALF22/23-FER module controls plant growth and salt stress responses by regulating hormonal homeostasis and ROS accumulation.

关键词： salt stress cell wall integrity growth LRX RALF FER hormone

Effects of elevated ozone on growth and yield of field-grown rice in Yangtze River Delta,China

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Journal of Environmental Sciences 2008年第3期20卷 320-325页

作者： CHEN Zhan WANG Xiaoke FENG Zhaozhong ZHENG Feixiang DUAN Xiaonan YANG Wenrui Research Center for Eco-Environmental Sciences Chinese Academy of Scienees Beijing 100085 China

With rapid industrialization and urbanization in the Yangtze Delta, China, the tropospheric ozone concentration has increased to levels that induce crop yield loss. Rice, a widely grown crop in China, was investigated in field-established, open-top chambers. Four treatments were used： charcoal-filtered air （CF）, non-charcoal-filtered air （NF）, and charcoal-filtered air with two levels of additional ozone （O3-1 and O3-2）. The AOT40s （accumulated hourly mean ozone concentration above 40 ppbv） were 0, 0.91, 23.24, and 39.28 ppmv.h for treatment of CE NF, O3-1, and O3-2, respectively. The rice height and biomass were reduced in the elevated ozone concentration. Less organic matter partitioning to roots under the elevated ozone significantly decreased rice root activity. The yield loss was 14.3% and 20.2% under O3-1 and O3-2 exposure, respectively. This was largely caused by a reduction in grain weight per panicle.

关键词： ozone rice growth yield Yangtze Delta