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| 1 | Pulse phase and doppler frequency estimation of X-ray pulsars under conditions of spacecraft and binary motion and its application in navigation显示文摘The pulse phase and doppler frequency estimation of X-ray pulsars in dynamic situations and its application in navigation is a problem that has not been fully investigated. In this paper, solutions are proposed to solve this problem under conditions of spacecraft and binary motion. A high-precision doppler frequency (velocity) measurement model as well as a phase (range) measurement model is established. The averaged maximum-likelihood estimator is developed for the dynamic pulse phase estimation. The pulse phase tracking technique is used in the doppler frequency determination. The tracking filter is redesigned and compared with the existing algorithms. The comparison verifies the advantage of the filter algorithm presented in this pa- per. Unlike traditional views, it is found that in dynamic situations, shorter observation interval lengths will result in higher-accuracy phase and frequency estimates as the tracking filter outputs. A photon-level integrated numerical simulation is performed. Simulation results testify to the validity of the proposed phase and doppler frequency estimation scheme, and show that incorporation of velocity measurements as well as the range ones into the navigation estimator will improve the navigation steady-state performance. | HUANG LiangWei LIANG Bin ZHANG Tao | 2013 | Science China(Physics,Mechanics & Astronomy)2013,56,4: | 11 |
| 2 | Root Zone Microbial Populations, Urease Activities, and Purification Efficiency for a Constructed Wetland显示文摘In order to investigate the effects of microorganisms and their urease activities in macrophytic root zones on pollutant removal, four small-scale plots (SSPs) of vertical/reverse-vertical flow wetlands were set up to determine: a) the relationship between the abundance of microorganisms in the root zones and water purification efficiency; and b) the relationship between urease activities in the root zones and pollutant removal in a constructed wetland system. Total numbers of the microbial population (bacteria, fungi, and actinomyces) along with urease activities in the macrophytic root zones were determined. In addition, the relationships between microbial populations and urease activities as well as the wastewater purification efficiencies of total phosphorus (TP), total Kjeldahl nitrogen (TKN), biochemical oxygen demand in 5 days (BOD5), and chemical oxygen demand (COD) were also analyzed. The results showed that there was a highly significant positive correlation (r = 0.9772, P < 0.01) between the number of bacteria in the root zones and BOD5 removal efficiency and a significant negative correlation (r = -0.9092, P < 0.05) between the number of fungi and the removal efficiency of TKN. Meanwhile, there was a significant positive correlation (r -- 0.8830, P < 0.05) between urease activities in the root zones and the removal efficiency of TKN. Thus, during wastewater treatment in a constructed wetland system,microorganism and urease activities in the root zones were very important factors. | LIANGWei WUZhen-Bin ZHANFa-Cui DENGJia-Qi | 2004 | Pedosphere2004,14,3: | 7 |
| 3 | Leaf choice in black-and-white snub-nosed monkeys Rhinopithecus bieti is related to the physical and chemical properties of leaves显示文摘To understand the effects of the chemical and physical properties of plant leaves on food choice in Rhinopithecus bieti,we collected mature leaves of nine food and five non-food plant species at the southernmost part of the species's range.Chemical properties such as fat, ash, crude protein (CP), total phenolics (TP), and fiber content including neutral detergent fiber(NDF), acid detergent fiber (ADF), lignin, celluloses and hemicelluloses, and physical toughness were measured. R. bieti tendedto choose leaves with lower fiber content, higher ash, a higher ratio of CP/ADF, and lower toughness. No difference was foundfor fat, crude protein, total phenolics, hemicelluloses and lignin between food and non-food leaves. Even though the ratio ofCP/ADF is generally regarded as a good indicator for colobine food choice, the difference in the ratio of CP/ADF between foodand non-food leaves was only the result of differences in ADF. Since positive correlations were found between ADF and toughnessfrom all leaves (both food and non-food species), and toughness of leaves was likely easier for R. bieti to sense than fibercontent via mastication, the toughness of leaves may function as a predictor of food choice in this species. | Zhipang HUANG Sheng HUO Shuguo YANG Liangwei CUI Wen XIAO | 2010 | Current Zoology2010,56,6: | 6 |
| 4 | Systematic Analysis Method of Shear-Wave Splitting:SAM Software System显示文摘In order to make a more effective use of the data from regional digital seismograph networks and to promote the study on shear wave splitting and its application to earthquake stress-forecasting, SAM software system, i.e., the software on systematic analysis method of shear wave splitting has been developed. This paper introduces the design aims, system structure, function and characteristics about the SAM software system and shows some graphical interfaces of data input and result output. Lastly, it discusses preliminarily the study of shear wave splitting and its application to earthquake forecasting. | GaoYuan LiuXiqiang LiangWei HaoPing | 2004 | Earthquake Research in China2004,18,4: | 5 |
| 5 | Broadband transmission-type 1-bit coding metasurface for electromagnetic beam forming and scanning显示文摘Coding metasurfaces make it possible to manipulate electromagnetic(EM)waves digitally by means of several discrete particles.Hence,there have been rapid advances in this field recently.Here we propose a novel design of a broadband transmission-type coding metasurface,which is valid to both x-and y-polarized EM incidences from 8.1-12.5 GHz while satisfies the requirements of 1-bit coding without changing the polarization.Two types of multi-layer coding particles with different geometrical parameters are adopted to represent the digital states'0'and'1',which are easily promoted to terahertz and optics through modifying the size scale.To verify the ability to manipulate the EM waves,we first adopt the coding metasurface to achieve broadband beam forming by converting spherical waves to plane waves and realize high-directivity pencil beam in far field with low side lobes.We further arrange the particles according to the coding sequence 010101…to steer two symmetrical beams in different directions controlled by frequencies with the maximum range of the scanning angle of 30°-50.5°.The good agreements between the simulated and measured results validate the proposed broadband coding metasurface,indicating its huge potential in communication and radar imaging systems. | RuiYuan Wu Lei Bao LiangWei Wu TieJun Cui | 2020 | Science China(Physics,Mechanics & Astronomy)2020,63,8: | 5 |
| 6 | Rethinking about the Formulae of the Relationship between Euler Angles and Texture显示文摘The formulae of the relationships between Euler angles and texture are important for the orientation distribution functions of research materials.At present,it is found that the formulae for the orthogonal and hexagonal crystal structure proposed by Roe and Bunge are not in accord with the normal direction(ND)being perpendicular to the rolling direction(RD).In this paper,these formulae are deduced independently according to the notations proposed by Roe and Bunge.The results show that in addition to the coincidence with the formulae for the cubic crystal structure given by the Roe and Bunge,the other formulae are different from Roe’s and Bunge’s.The new formulae are in accord with ND,RD,and transverse direction(TD)at right angles. | Liangwei Chen Yuyu Hui Lan Yu Jin Hu Jianhong Yi | 2021 | Journal of Harbin Institute of Technology(New Series)2021,28,5: | 4 |
| 7 | LEO Enhanced Global Navigation Satellite System(LeGNSS):progress,opportunities,and challenges显示文摘With the completion of Chinese BeiDou Navigation Satellite System(BDS),the world has begun to enjoy the Positioning,Navigation,and Timing(PNT)services of four Global Navigation Satellite Systems(GNSS).In order to improve the GNSS performance and expand its applications,Low Earth Orbit(LEO)Enhanced Global Navigation Satellite System(LeGNSS)is being vigorously advocated.Combined with high-,medium-,and low-earth orbit satellites,it can improve GNSS performance in terms of orbit determination,Precise Point Positioning(PPP)convergence time,etc.This paper comprehensively reviews the current status of LeGNSS,focusing on analyzing its advantages and challenges for precise orbit and clock determination,PPP convergence,earth rotation parameter estimation,and global ionosphere modeling.Thanks to the fast geometric change brought by LEO satellites,LeGNSS is expected to fundamentally solve the problem of the long convergence time of PPP without any augmentation.The convergence time can be shortened within 1 minute if appropriate LEO constellations are deployed.However,there are still some issues to overcome,such as the optimization of LEO constellation as well as the real time LEO precise orbit and clock determination. | Haibo Ge Bofeng Li Song Jia Liangwei Nie Tianhao Wu Zhe Yang Jingzhe Shang Yanning Zheng Maorong Ge | 2022 | Geo-Spatial Information Science2022,25,1: | 4 |
| 8 | Numerical investigation on flow and heat transfer characteristics of supercritical RP-3 in inclined pipe显示文摘Numerical simulations of flow and heat transfer to supercritical RP-3 through the inclined tubes have been performed using LS k–e model embedded in Fluent. The physical properties of RP-3 were obtained using the generalized corresponding state laws based on the fourcomponent surrogate model. Mass flow rate is 0.3 g/s, system pressure is 3 MPa, inlet temperature is 373 K. Inclination of the inclined pipe varied from -90° to 90°, with heat flux varied from 300 k W/m^2 to 400 kW/m^2. Comparison between the calculated result and the experimental data indicates the range of error reasonable. The results of ±45° show that temperature inhomogeneity in inclined pipe produce the secondary flow in its cross section due to the buoyancy force. Depending on the strength of the temperature inhomogeneity, there will be two different forms of secondary flow and both contribute to the convective heat transfer in the pipe. The secondary flow intensity decreases when the inhomogeneity alleviates and thermal acceleration will play a leading role. It will have a greater impact on the turbulent flow to affect the convective heat transfer in the pipe. When changing the inclination, it affects the magnitude of the buoyant component in flow direction. The angle increases, the buoyancy component decreases. And the peak temperature of wall dominated by the secondary flow will move forward and increase in height. | Zhi TAO Liangwei LI Jianqin ZHU Xizhuo HU Longyun WANG Lu QIU | 2019 | Chinese Journal of Aeronautics2019,32,8: | 3 |
| 9 | Navigation using binary pulsars显示文摘The issue of navigation using binary pulsars is investigated in this paper.We show how the effect of the binary motion is incorporated in the navigation measurement equation.Necessary reference systems and time scales are introduced and the transformation between different time scales is derived.Based mainly on Damour and Deruelle's binary model and the TEMPO2 software,the timing model resolving the time delay from emission to arrival is established with the solar system,interstellar and binary system delays included,which retains all the terms exceeding 1 ns.The navigation measurement equation is thus built and the parameters needed are listed.A comparison is made between Sheikh's measurement equation and that in this paper.It is found that it is not necessary to introduce a fictitious SSB arrival time as Sheikh does.Near-Earth navigation for the Keplerian orbit in the case of observing one pulsar is investigated.The uncertainties of the orbit parameters are derived using the least square fitting method,which reveals that observing one pulsar enables one to navigate near-Earth spacecraft. | HUANG LiangWei LIANG Bin ZHANG Tao ZHANG CaiHong | 2012 | Science China(Physics,Mechanics & Astronomy)2012,55,3: | 3 |
| 10 | Long-term variations of X-ray pulse profiles for the Crab pulsar:data analysis and modeling显示文摘The pulse profiles of the Crab pulsar(as well as some other pulsars)vary with time.They can lead to a major source of intrinsic timing noise,which lacks a detailed physical model.The phase separation?between the first left peak(P1)and the second right peak(P2)is a key parameter that shows the variations of pulse profiles for the Crab pulsar.It was found that the evolution of?has a tendency with increasing rates of 0.82?±0.25?,0.80?±0.54?,and 0.77?±0.28?per century for the 2-6,6-15,and15-60 ke V bands,respectively.Furthermore,the flux ratios(P2/P1)of X-ray pulse profiles in the three bands were calculated,and the derived flux ratios were consistent with the radio and X-ray measurements of the Insight-HXMT.In addition to discovering the physical origin of the pulse changes,the high-SNR X-ray pulse profiles were simulated in the annular gap model,and two model parameters(e.g.,the maximum emission heights of the two peaks)were observed to slightly affect the variations of peak separation.We fitted the long-term variations of emission heights of the two peaks and discovered that the emission heights showed increasing tendencies with time.Variations of these emission heights induced a characteristic period derivative,and a complete formula for both the magnetic dipole radiation and wind-particle-induced variations of the moment of inertia was used for the pulsar’s spin-down to obtain the variation rate˙αof the magnetic inclination angle,which was-1.60?per century.Intrinsic timing noise is observed to be mainly induced by the variations of pulse profiles,which might correlate with a characteristic spin period derivative arising from the fluctuations of the emission regions.This work will lay a foundation for understanding the origin of intrinsic timing noise and making high-precision timing models in the future. | LunHua Shang YuanJie Du XiangQun Cui ShiJun Dang JiGuang Lu JunTao Bai QiJun Zhi YouLi Tuo LinLi Yan LiangWei Huang XinYuan Zhang XiaoMin Bei QingQing Lin GuoJun Qiao Hua Shen RiHong Zhu | 2020 | Science China(Physics,Mechanics & Astronomy)2020,63,10: | 2 |
| 11 | Rapid detection of Listeria monocytogenes by nanoparticle-based immunomagnetic separation and real-time PCR显示文摘 | Hua Yang Liangwei Qu Adrienne N. Wimbrow Xiuping Jiang Yaping Sun | 2007 | International Journal of Food Microbiology2007,,2: | 2 |
| 12 | Mechanism of inversion metallogeny of quartz vein type gold deposits in the Xiaoqinling region显示文摘There are a lot of important gold_bearing quartz veins in the Xiaoqinling metamorphic core complex. The quartz veins are strictly controlled by shear zones. Stress analysis indicates that the metallizing process of the Xiaoqinling gold deposits of quartz vein type can be divided into two stages. At the first stage, the shear zones were formed in an extensional environment, and the temperature was higher and the buried depth was greater; at the second stage, the brittle thrusts were superimposed in ductile shear zones after the tectonic stress field turned from the extension to compression. The ore_bearing fluids were concentrated in these weak positions, and the gold deposits of quartz vein type were developed. | Liangwei Xue Quanzeng Shi Xiangdong Yu Yadong Zheng Jinjiang Zhang | 1998 | Chinese Science Bulletin1998,43,10: | 2 |
| 13 | Recent advances in room-temperature phosphorescent materials by manipulating intermolecular interactions显示文摘Metal-free room-temperature phosphorescence(RTP)materials have the characteristics of large Stokes shift,long lifetime,and triplet state transition.They exhibit application potential in various fields,such as bioimaging,computer display,sensor,and anticounterfeiting and have drawn much research interest.Recent work showed that manipulating intermolecular interactions(e.g.,crystallization,polymerization,and rigid matrix)and host-guest assembly to restrain nonradiative transitions and isolate phosphor from oxygen as much as possible is a feasible way to obtain various types of efficient RTP materials.In some cases,intermolecular interactions also facilitated RTP emission by regulating the triplet state.On the other hand,heavy atoms(Br,I,etc.),heteroatoms(N,O,S,etc.),or carbonyls were introduced to the molecular skeleton through molecular engineering to enhance intersystem crossing,which is important for populating the triplet exciton.By comprehensively using the aforesaid strategies,great progress has been made for RTP materials.In this mini-review,we summarized recent advances in organic RTP materials based on manipulating intermolecular interactions.Typical host-guest assembly,hydrogen-bond assembly,energy transfer process,and exciplex emission system-based RTP materials were well illustrated.In summary,the current challenges and prospects for development in this field were presented. | Liangwei Ma Xiang Ma | 2023 | Science China Chemistry2023,66,2: | 2 |
| 14 | A dynamically evolving war between autophagy and pathogenic microorganisms显示文摘Autophagy is an intracellular degradation process that maintains cellular homeostasis.It is essential for protecting organisms from environmental stress.Autophagy can help the host to eliminate invading pathogens,including bacteria,viruses,fungi,and parasites.However,pathogens have evolved multiple strategies to interfere with autophagic signaling pathways or inhibit the fusion of autophagosomes with lysosomes to form autolysosomes.Moreover,host cell matrix degradation by different types of autophagy can be used for the proliferation and reproduction of pathogens.Thus,determining the roles and mechanisms of autophagy during pathogen infections will promote understanding of the mechanisms of pathogen-host interactions and provide new strategies for the treatment of infectious diseases. | Qianqian ZHENG Liangwei DUAN Yang ZHANG Jiaoyang LI Shiyu ZHANG Hui WANG | 2022 | Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2022,23,1: | 2 |
| 15 | Influence of the alkyl side chain length on the room-temperature phosphorescence of organic copolymers显示文摘Pure organic room-temperature phosphorescence(RTP)materials have attracted wide attention owing to their excellent luminescent properties and great potential in various applications.In this work,iminostilbene and its analogues are applied to realize RTP emission by copolymerizing with acrylamide.It can be concluded that the growth of alkane chain in monomers can enhance the lifetime and photoluminescence quantum yield of RTP emission,and polymers with the larger conjugated structure of the monomer show a longer RTP emission wavelength.This work provides a series of new pure organic RTP materials and might provide new thoughts for designing more advanced and superior RTP materials. | Qingyang Xu Liangwei Ma Xiaohan Lin Qiaochun Wang Xiang Ma | 2022 | Chinese Chemical Letters2022,33,6: | 2 |
| 16 | Application of Probiotics in Pig Industry as a Substitute of Antibiotics显示文摘Antibiotics plays a positive role in the development of livestock breeding and feed industry,but has also disadvantages impossible to overcome,so it is an inevitable trend of prohibiting application of antibiotics in feed.This paper reviewed concept and action mechanism of the antibiotics substitute—probiotics,and its application in piglets,growing and fattening pigs and sows. | Sha Wenfeng Zhu Juan Gu Yongjian Dai Hui Qiu Liangwei | 2015 | Animal Husbandry and Feed Science2015,7,1: | 2 |
| 17 | Regulating surface wrinkles using light显示文摘Regulating existing micro and nano wrinkle structures into desired configurations is urgently necessary yet remains challenging,especially modulating wrinkle direction and location on demand.In this work,we propose a novel light-controlled strategy for surface wrinkles,which can dynamically and precisely regulate all basic characteristics of wrinkles,including wavelength,amplitude,direction and location(λ,A,θand Lc),and arbitrarily tune wrinkle topographies in two dimensions(2 D).By considering the bidirectional Poisson’s effect and soft boundary conditions,a modified theoretical model depicting the relation between stress distributions and the basic characteristics was developed to reveal the mechanical mechanism of the regulation strategy.Furthermore,the resulting 2 D ordered wrinkles can be used as a dynamic optical grating and a smart template to reversibly regulate the morphology of various functional materials.This study will pave the way for wrinkle regulation and guide fabrication technology for functional wrinkled surfaces. | Liangwei Zhou Kaiming Hu Wenming Zhang Guang Meng Jie Yin Xuesong Jiang | 2020 | National Science Review2020,7,7: | 2 |
| 18 | Gap-type dark localized modes in a Bose-Einstein condensate with optical lattices显示文摘Bose-Einstein condensate(BEC)exhibits a variety of fascinating and unexpected macroscopic phenomena,and has attracted sustained attention in recent years-particularly in the field of solitons and associated nonlinear phenomena.Meanwhile,optical lattices have emerged as a versatile toolbox for understanding the properties and controlling the dynamics of BEC,among which the realization of bright gap solitons is an iconic result.However,the dark gap solitons are still experimentally unproven,and their properties in more than one dimension remain unknown.In light of this,we describe,numerically and theoretically,the formation and stability properties of gap-type dark localized modes in the context of ultracold atoms trapped in optical lattices.Two kinds of stable dark localized modes-gap solitons and soliton clusters-are predicted in both the one-and two-dimensional geometries.The vortical counterparts of both modes are also constructed in two dimensions.A unique feature is the existence of a nonlinear Bloch-wave background on which all above gap modes are situated.By employing linear-stability analysis and direct simulations,stability regions of the predicted modes are obtained.Our results offer the possibility of observing dark gap localized structures with cutting-edge techniques in ultracold atoms experiments and beyond,including in optics with photonic crystals and lattices. | Liangwei Zeng Jianhua Zeng | 2019 | Advanced Photonics2019,1,4: | 2 |
| 19 | Process of simultaneous hydrogen sulfide removal from biogas and nitrogen removal from swine wastewater 显示文摘 | Deng Liangwei Chen Huijuan Chen Ziai | 2009 | Bioresour Teehnol2009,100,: | 1 |
| 20 | Study on the Formation Mechanism of the Solid Siliconized Layer on Ti-48Al Alloy显示文摘The microstructures of the siliconized specimens of Ti-48Al alloy were analyzed by SEM equipped with XEDS. The specimens were pack siliconized with the two different cementations, 15%Si+85% A12O3 and 15%Si+85%ZrO2. The results show that a composite siliconized layer is formed on the surface of the TiAl alloy. The outer layer is the continuous A12O3 where a lot of Si particles adhered; the inner layer is most of Ti5Si3 with amount of ALjOs particles dispersed in. It was deduced that the A12O3 in the cementation layer is formed by the Al atoms in the TiAl substrate react with the residual O in the furnace and in the TiAl substrate. | MAXiao-xia LIANGWei ZHAOXing-guo SHIJu-yan BIANLi-ping | 2004 | 材料热处理学报2004,25,05B: | 1 |