维普中文期刊产品整合服务
48篇 您的检索式:作者名="LIU Liwu"
    题名 作者 年代 出处 被引量
1Surface Modification of Fly Ashes with Carbide Slag and Its Effect on Compressive Strength and Autogenous Shrinkage of Blended Cement Pastes显示文摘Surfaces of grade III fly ashes were modified through mixing with carbide slag and calcining at 850 ℃ for 1 h. Mineralogical compositions and surface morphology of fly ashes before and after modification were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Effect of surface-modified fly ashes on compressive strength and autogenous shrinkage of blended cement pastes was investigated. Microstructures of cement pastes were examined by backscattered electron (BSE) imaging and mercury intrusion porosimetry (MIP). The experimental results showed that β-C2S was formed on the surfaces of fly ashes after modification. Hydration of β-C2S on the surface-modified fly ashes densified interface zone and enhanced bond strength between particles of fly ashes and hydrated clinkers. In addition, surface modification of fly ashes tended to decrease total porosity and 10-50 nm pores of cement pastes. Surface modification of fly ashes increased compressive strength and reduced autogenous shrinkage of cement pastes.郝成伟 邓敏 MO Liwu LIU Kaiwei 2012Journal of Wuhan University of Technology(Materials Science)2012,27,6:15
2Stability analysis of dielectric elastomer film actuator显示文摘Dielectric elastomer (DE) is the most promising electroactive polymer material for smart actuators. When a piece of DE film is sandwiched between two compliant electrodes with a high electric field,due to the electrostatic force between the two electrodes,the film expands in-plane and contracts out-of-plane so that its thickness becomes thinner. The thinner thickness results in a higher electric field which inversely squeezes the film again. When the electric field exceeds the critical value,the dielectric field breaks down and the actuator becomes invalid. An elastic strain energy function with two material constants is used to analyze the stability of the dielectric elastomer actuator based on the nonlinear electromechanical field theory. The result shows that the actuator improves its stability as the ratio k of the material constants increases,which can be applied to design of actuators. Finally,this method is extended to study the stability of dielectric elastomers with elastic strain energy functions containing three and more material constants.LIU YanJu LIU LiWu SUN ShouHua ZHANG Zhen LENG JinSong 2009Science China(Technological Sciences)2009,52,9:7
3World’s first spaceflight on-orbit demonstration of a flexible solar array system based on shape memory polymer composites显示文摘With a 10%reversible compressive strain in more than 10 deformation cycles,the shape memory polymer composites(SMPCs)could be used for deployable structure and releasing mechanism.In this paper,without traditional electro-explosive devices or motors/controllers,the deployable SMPC flexible solar array system(SMPC-FSAS)is studied,developed,ground-based tested,and finally on-orbit validated.The epoxy-based SMPC is used for the rolling-out variable-stiffness beams as a structural frame as well as an actuator for the flexible blanket solar array.The releasing mechanism is primarily made of the cyanate-based SMPC,which has a high locking stiffness to withstand 50 g gravitational acceleration and a large unlocking displacement of 10 mm.The systematical mechanical and thermal qualification tests of the SMPC-FSAS flight hardware were performed,including sinusoidal sweeping vibration,shocking,acceleration,thermal equilibrium,thermal vacuum cycling,and thermal cycling test.The locking function of the SMPC releasing mechanisms was in normal when launching aboard the SJ20 Geostationary Satellite on 27 Dec.,2019.The SMPC-FSAS flight hardware successfully unlocked and deployed on 5 Jan.,2020 on geostationary orbit.The triggering signal of limit switches returned to ground at the 139 s upon heating,which indicated the successful unlocking function of SMPC releasing mechanisms.A pair of epoxy-based SMPC rolled variable-stiffness tubes,which clapped the flexible blanket solar array,slowly deployed and finally approached an approximate 100%shape recovery ratio within 60 s upon heating.The study and on-orbit successful validation of the SMPC-FSAS flight hardware could accelerate the related study and associated productions to be used for the next-generation releasing mechanisms as well as space deployable structures,such as new releasing mechanisms with low-shocking,testability and reusability,and ultra-large space deployable solar arrays.LAN Xin LIU LiWu ZHANG FengHua LIU ZhengXian WANG LinLin LI QiFeng PENG Fan HAO SiDa DAI WenXu WAN Xue TANG Yong WANG Mian HAO YanYan YANG Yang YANG Cheng LIU YanJu LENG JinSong 2020Science China(Technological Sciences)2020,63,8:7
4Recent Advances in Space-Deployable Structures in China显示文摘Deployable space structure technology is an approach used in building spacecraft,especially when realizing deployment and folding functions.Once in orbit,the structures are released from the fairing,deployed,and positioned.With the development of communication,remote-sensing,and navigation satellites,space-deployable structures have become cutting-edge research topics in space science and technology.This paper summarizes the current research status and development trend of spacedeployable structures in China,including large space mesh antennas,space solar arrays,and deployable structures and mechanisms for deep-space exploration.Critical technologies of space-deployable structures are addressed from the perspectives of deployable mechanisms,cable-membrane form-finding,dynamic analysis,reliable environmental adaptability analysis,and validation.Finally,future technology developments and trends are elucidated in the fields of mesh antennas,solar arrays,deployable mechanisms,and on-orbit adjustment,assembly,and construction.Xiaofei Ma Tuanjie Li Jingya Ma Zhiyi Wang Chuang Shi Shikun Zheng Qifeng Cui Xiao Li Fan Liu Hongwei Guo Liwu Liu Zuowei Wang Yang Li 2022Engineering2022,,10:6
5Abiogenic hydrocarbons in commercial gases from the Songliao Basin,China显示文摘This paper discusses the kinetic fractionation, composition and distribution characteristics of carbon and hydrogen isotopes for various alkane gases formed in different environments, by different mecha- nisms and from different sources in nature. It is demonstrated that the biodegradation or thermode- gradation of complex high-molecule sedimentary organic material can form microbial gas or thermogenic gas. The δ 13C1 value ranges from -110‰ to -50‰ for microbial gases but from -50‰ to -35‰ (even heavier) for thermogenic gases. Controlled by the kinetic isotope fractionation, both microbial and thermogenic gases have δ 13C and δ D values characterized by normal distribution, i.e. δ 13C1< δ 13C2< δ 13C3< δ 13C4 and δ DCH4< δ DC2H6< δ DC3H8<δ DC4H10, and by a positive correlation between the δ 13C and δ D values. Simple carbonbearing molecules (CH4, CO and CO2) can form abiogenic alkane gases via polymerization in the abiological chemical process in nature, with δ 13C1 heavier than -30‰. Moreover, controlled by the kinetic isotope fractionation, abiogenic alkane gases are characterized by a reverse distribution of δ 13C values and a normal trend of δ D values, namely δ 13C1> δ 13C2> δ 13C3> δ 13C4 and δ DCH4<δ DC2H6< δ DC3H8< δ DC4H10. The δ 13C values and δ D values are negatively correlated. Natural gases from 26 commercial gas wells distributed in the Xujiaweizi and Yingshan-Miaotaizi faulted depressions in the Songliao Basin, China, show δ13C1 values ranging from -30.5‰ to -16.7‰ with a very narrow δ D range between -203‰―-196‰. These gases are characterized by a reverse distribution of δ 13C values but a normal distribution of δ D values, and a negative correlation between their δ 13C and δ D values, indicating an abiological origin. The present study has revealed that abiogenic hydrocarbons not only exist in nature but also can make significant contribution to commercial gas reserviors. It is estimated that the reserve volume of alkane gases with abiogenic characteristics in these 26 gas wells in the Songliao Basin is over 500×108 m3. The prospecting practice in the Songliao Basin has demonstrated that abiogenic alkane gases are of a promising resource, and it provides an example for the investigation of and search for abiogenic commercial natural gases worldwide.WANG XianBin GUO ZhanQian TUO JinCai GUO HongYan LI ZhenXi ZHUO ShengGuang JIANG HongLiang ZENG LongWei ZHANG MingJie WANG LianSheng LIU ChunXue YAN Hong LI LiWu ZHOU XiaoFeng WANG YongLi YANG Hui WANG Guang 2009Science China Earth Sciences2009,52,2:6
6In Situ Regeneration of Mo/MCM-22 with 1%O_2 at Reaction Temperature显示文摘BAI Jie, XIE Sujuan, LIU Shenglin, XU Longya, LIN Liwu (State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian 116023, Liaoning, China) 2003催化学报2003,24,11:4
7Enhanced Moth-flame Optimization Based on Cultural Learning and Gaussian Mutation显示文摘Liwu Xu Yuanzheng Li Kaicheng Li Gooi Hoay Beng Zhiqiang Jiang Chao Wang Nian Liu 2018Journal of Bionic Engineering2018,15,4:4
84D printing of personalized shape memory polymer vascular stents with negative Poisson’s ratio structure:A preliminary study显示文摘Four-dimensional(4D)printing,integrates transformation information into three-dimensional(3D)-printed structures,which means that 3D-printed structures are able to change their shapes,properties,or functionalities over time.Here,two types of shape memory personalized vascular stents with negative Poisson’s ratio structure are developed via 4D printing.The genetic algorithm is used to optimize the structure.Axial compression tests,radial compression tests and three-point bending tests are carried out to study the mechanical properties of the stents.In addition,fluid-structure interaction and stress distribution during the shape recovery process are investigated based on finite element method.The shape memory behaviors of the stents are excellent and in vitro feasibility tests demonstrate that the stents can expand the simulated narrow blood vessel rapidly.Therefore,4D printed shape memory stents with negative Poisson’s ratio structure are highly promising for the treatment of vascular stenosis.LIN Cheng ZHANG LiJin LIU YanJu LIU LiWu LENG JinSong 2020Science China(Technological Sciences)2020,63,4:3
9An isotope study of the accumulation mechanisms of high-sulfur gas from the Sichuan Basin, southwestern China显示文摘The mechanism of hydrogen sulfide(H_2S) generation plays a key role in the exploration and development of marine high-sulfur natural gas, of which the major targets are the composition and isotope characteristics of sulfur-containing compounds.Hydrocarbon source rocks, reservoir rocks, natural gases and water-soluble gases from Sichuan Basin have been analyzed with an online method for the content of H_2S and isotopic composition of different sulfur-containing compounds. The results of comparative analysis show that the sulfur-containing compounds in the source rocks are mainly formed by bacterial sulfate reduction(BSR), and the sulfur compounds in natural gas, water and reservoir are mainly formed by thermal sulfate reduction(TSR). Moreover, it has been shown that the isotopically reversion for methane and ethane in high sulfur content gas is caused by TSR. The sulfur isotopic composition of H_2S in natural gas is inherited from the gypsum or brine of the same or adjacent layer,indicating that the generation and accumulation of H_2S have the characteristics of either a self-generated source or a near-source.LIU WenHui Tenger ZHANG ZhongNing LUO HouYong ZHANG DianWei WANG Jie LI LiWu GAO Bo LU LongFei ZHAO Heng 2016Science China Earth Sciences2016,59,11:2
10Extension limit,polarization saturation,and snap-through instability of dielectric elastomers显示文摘A dielectric elastomer is capable of large voltage-induced deformation,particularly when the voltage is applied on the verge of snap-through instability.A model is described which shows that the snap-through instability is markedly affected by both the extension limit of polymer chains and the polarization saturation of dipoles.The model may guide the search for high-performance dielectric elastomer transducers.Bo Li Liwu Liu Zhigang Suo 2011International Journal of Smart and Nano Materials2011,2,2:2
11Micro and nanolattice fabrication using projection micro litho stereo exposure additive manufacturing techniques and synchrotron X-ray 3D imaging-based defect characterization显示文摘Synchrotron radiation X-ray micro-computed tomography(SR-μCT)is a 3D imaging technique that is widely employed for the characterization of defects in advanced materials and structures.In this study,we characterize several typical defects in octettruss and re-entrant 3D lattice structures by using SR-μCT.The 3D micro-lattice structures are manufactured using projection micro litho stereo exposure(PμLSE)additive manufacturing technology.The as-fabricated 3D lattice samples are characterized using optical microscopy,and subsequently,by SR-μCT.Further more,a statistical analysis is performed to characterize the surface roughness and internal defects qualitatively,whereby the statistical geometrical parameters of struts along different directions and strut joints are analyzed and classified.Consequently,several typical defects are identified:(1)holes at the joints of the strut and irregular diameter deviations of the strut in the octet-truss lattice structure;(2)irregular diameter variations,bulges,dislocations,grooves,accumulations,and torsion in the re-entrant lattice structure.All of these defects are related to the building direction,the weight of the structure,bubbles,dust,and impurities during the PμLSE additive manufacturing process.HU WenXia LIU LiWu WU WenWang XI Li LENG JinSong FANG DaiNing 2020Science China(Technological Sciences)2020,63,4:2
12Low power 3.1–10.6 GHz IR-UWB transmitter for Gbps wireless communications显示文摘This paper reviews and discusses the design of a low-power single-full-band (3.1-10.6 GHz) non- carrier impulse-radio ultra wideband (UWB) transmitter featuring 5th-order Gaussian derivative pulse shaping, integrated BPSK modulation, and 2.5 kV whole-chip ESD (electrostatic discharge) protection. The UWB transmitter design has been implemented in a commercial 0.18 μm CMOS technology with a very small die size of 0.25 mm2. The fabricated chips have demonstrated full functionality, extremely low power consumption of 0.14 pJ/p-mV, and an ultra short pulse width of 394 ps. This ESD-protected UWB transmitter has the potential to support wireless streaming to gigabit per second (Gbps).WANG Xin LIN Lin TANG He ZHAO Hui FANG Qiang LIU Jian FAN SiQiang WANG Albert ZHAO Bin YANG LiWu ZHANG Gary 2011Science China(Information Sciences)2011,54,5:2
13Mechanical Models,Structures,and Applications of Shape-Memory Polymers and Their Composites显示文摘Shape-memory polymers(SMPs)and their composite materials are stimuliresponsive materials that have the unique characteristics of lightweight,large deformation,variable stiffness,and biocompatibility.This paper reviews the research status of the mechanical models for SMPs,shape-memory nanocomposites and shape-memory polymer composites(SMPCs);it also introduces some spatially deployable structures,such as hinges,beams,and antennae based on SMPCs.In addition,the deformation types of 4D printing structures and the potential applications of this technology in robots and medical devices are also summarized.Xiaozhou Xin Liwu Liu Yanju Liu Jinsong Leng 2019Acta Mechanica Solida Sinica2019,32,5:2
14Fast formation of NaA zeolite membrane in the microwave field显示文摘NaA zeolite membrane was successfully synthesized on the porous α-Al2O3 support by microwave heating. The synthesis of NaA zeolite membrane in the microwave field only needs 15 min and the synthesis time is 10 times shorter than that by conventional heating. SEM characterization indicates that the zeolite crystals in the NaA zeolite membrane synthesized by microwave heating are uniform in size; the membrane thickness is about 4 μm and is thinner than that of the NaA zeolite membrane synthesized by conventional heating. Gas permeation studies indicate that the permeances of the NaA zeolite membrane synthesized by microwave heating are 3-4 times higher than those of the NaA zeolite membrane synthesized by conventional heating, while their permselectivities are comparable.Xiaochun Xu Weishen Yang Jie Liu Liwu Lin 2000Chinese Science Bulletin2000,45,13:2
15Preliminary design and analysis of a cubic deployable support structure based on shape memory polymer composite显示文摘The deployable structures based on shape memory polymer com-posites(SMPCs)have been developed for its unique properties,such as high reliability,low-cost,lightweight,and self-deployment without complex mechanical devices compared with traditional deployable structures.In order to increase the inflatable structure system’s robustness and light the weight of it,a cubic deployable support structure based on SMPC is designed and analyzed pre-liminarily.The cubic deployable support structure based on SMPC consists of four dependent spatial cages,each spatial cage is composed of 12 three-longeron SMPC truss booms and end con-nections.The shape recovery of arc-shaped deployable laminates drive the three-longeron SMPC truss booms to unfold,thus realize the expansion of the deployable support structure.The concept and operation of the cubic deployable support structure are described in detail.A series of experiments are performed on the three-longeron deployable laminates unit and the simplified cubic deployable support structure to investigate the shape recovery behavior in the deployment process.Results indicate that the cubic deployable support structure has a high deployment-tgo-stowage volume ratio and can achieve self-deployment,package,and deploy without complex mechanical devices.Fengfeng Li Liwu Liu Xin Lan Xiaojun Zhou Wenfeng Bian Yanju Liu Jinsong Leng 2016International Journal of Smart and Nano Materials2016,7,2:1
16The compatibility of polylactic acid and polybutylene succinate blends by molecular and mesoscopic dynamics显示文摘The compatibility of polylactic acid(PLA)/polybutylene succinate(PBS)blends was studied by molecular dynamics and mesoscopic dynamics,which is a controversial issue in experiments.Six simulation models of PLA/PBS with different composition ratios(100/0,90/10,80/20,70/30,60/40,0/100)were constructed.The radial distribution function,hydrogen bond,free energy density,order parameter and iso-density surface morphology of the PLA/PBS systems were simulated and analyzed.Due to the formation of hydrogen bonds and van der Waals bonds between different elements of PLA chains and PBS chains,the PLA/PBS blends exhibit good compatibility at all composition ratios.Cheng Lin Liwu Liu Yanju Liu Jinsong Leng 2020International Journal of Smart and Nano Materials2020,11,1:1
17Shape Selectivity in Methane Dehydroaromatization Over Mo/MCM-22 Catalysts During a Lifetime Experiment显示文摘J. Bai Shenglin Liu Sujuan Xie Longya Xu Liwu Lin 2003Catalysis Letters (-)2003,,3:1
18Study of activated carbon supported iron catalysts for the Fischer-Tropsch synthesis显示文摘Wenping Ma Yunjie Ding Jing Yang Xing Liu Liwu Lin 2005Reaction Kinetics and Catalysis Letters2005,,1:1
19Regeneration behaviors of Fe/Si‐2 and Fe–Mn/Si‐2 catalysts for C2H6 dehydrogenation with CO2 to C2H4显示文摘Longya Xu Jinxiang Liu Hong Yang Yide Xu Qingxia Wang Liwu Lin 1999Catalysis Letters (-)1999,,2:1
20Hydrogen isotopic compositions of n-alkanes from terrestrial plants correlate with their ecological life forms显示文摘Weiguo Liu Hong Yang Liwu Li 2006Oecologia2006,,2:1
返回顶部 每页显示:
共3页 首页 上一页 第1页 下一页 末页 /3 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费