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Innovative Group-Decoupling Design of a Segment Erector Based on G_F Set Theory

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Chinese Journal of Mechanical Engineering 2013年第2期26卷 264-274页

作者： guo Wentao guo weizhong gao feng MO Pinxi State Key Laboratory of Mechanical Systems and Vibration Shanghai Jiao Tong University

The segment erector is a key part of the shield machines for tunnel engineering. The available segment erectors are all of serial configuration which is suffering from the problems of low rigidity and accumulative motion errors. The current research mainly focuses on improving assembly accuracy and control performance of serial segment erectors. An innovative design method is proposed featuring motion group-decoupling, based on which a new type of segment erector is developed and investigated. Firstly, the segment installation manipulation is analyzed and decomposed into three motion groups that are decoupled. Then the type synthesis for the 4-DOF motion group is performed based on the general function（GF） set theory and a new configuration of （1T？1R？1PS3UPS） is attained according to the segment manipulation requirements. Consequently, the kinematic models are built and the reducibility and accuracy are analyzed. The dexterity is verified though numerical simulation and no singular points appear in the workspace. Finally, a positioning experiment is carried out by using the prototype developed in the lab that demonstrates a 13.1% improvement of positioning accuracy and the feasibility of the new segment erector. The presented group-decoupling design method is able to invent new type of hybrid segment erectors that avoid the accumulative motion error of erecting.

关键词： segment erector group-decoupling design type synthesis parallel mechanism GF Set

Type Synthesis for 4-DOF Parallel Press Mechanism Using G_F Set Theory

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Chinese Journal of Mechanical Engineering 2015年第4期28卷 851-859页

作者： HE Jun gao feng MENG Xiangdun guo weizhong State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University

Parallel mechanisms is used in the large capacity servo press to avoid the over-constraint of the traditional redundant actuation. Currently, the researches mainly focus on the performance analysis for some specific parallel press mechanisms. However, the type synthesis and evaluation of parallel press mechanisms is seldom studied, especially for the four degrees of freedom（DOF） press mechanisms. The type synthesis of 4-DOF parallel press mechanisms is carried out based on the generalized function（GF） set theory. Five design criteria of 4-DOF parallel press mechanisms are firstly proposed. The general procedure of type synthesis of parallel press mechanisms is obtained, which includes number synthesis, symmetrical synthesis of constraint GF sets, decomposition of motion GF sets and design of limbs. Nine combinations of constraint GF sets of 4-DOF parallel press mechanisms, ten combinations of GF sets of active limbs, and eleven combinations of GF sets of passive limbs are synthesized. Thirty-eight kinds of press mechanisms are presented and then different structures of kinematic limbs are designed. Finally, the geometrical constraint complexity（GCC）, kinematic pair complexity（KPC）, and type complexity（TC） are proposed to evaluate the press types and the optimal press type is achieved. The general methodologies of type synthesis and evaluation for parallel press mechanism are suggested.

关键词： parallel mechanism type synthesis GF Set type evaluation press mechanism

Optimized multiuser detection algorithm for uplink SCMA system

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The Journal of China Universities of Posts and Telecommunications 2017年第1期24卷 11-17页

作者： Tan Yuxi gao Zehua guo Siyan gao feng School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Sparse code multiple access （SCMA） is a competitive nonorthogonal access scheme for the next mobile communication. As a multiuser sharing system, SCMA adopts message passing algorithm （MPA） for decoding scheme in receiver, but its iterative method leads to high computational complexity. Therefore, a serial message passing algorithm based on variable node （VMPA） is proposed in this paper. Making some subtle alterations to message update in original MPA, VMPA can greatly reduce overall computing complexity of decoding scheme. Furthermore, considering that serial structure may increase decoding delay, a novel grouping scheme based sparse matrix is applied to VMPA. Simulation results verify that the new algorithm, termed as grouping VMPA （G-VMPA）, can achieve a better tradeoff between bit error rate （BER） and computing complexity than MPA.

关键词： SCMA MPA computational complexity

Solidification of solvent additive for stable binary polymer solar cells with~19%efficiency

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Science China Materials 2023年第6期66卷 2523-2524页

作者： Hongru Chen Zhi-guo Zhang feng gao State Key Laboratory of Chemical Resource Engineering Beijing Engineering Research Center for the Synthesis and Applications of Waterborne PolymersBeijing University of Chemical TechnologyBeijing 100029China Department of Physics Biomolecular and organic electronicsChemistry and Biology(IFM)Linköping UniversityLinköping SE-58183Sweden

Polymer solar cells(PSCs)have garnered considerable attention due to their numerous benefits,such as solution-processability,and potential applications in flexible and semitransparent *** the development of photovoltaic materials and device structures,power conversion efficiencies(PCEs)of PSCs have exceeded 19%to date[1,2].Moreover,an ideal morphology for efficient and stable PSCs is extremely essential[3,4].

关键词： additive polymer benefits

Improved preparation and identification of aristolochic acid-DNA adducts by solid-phase extraction with liquid chromatography-tandem mass spectrometry

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Journal of Environmental Sciences 2009年第12期21卷 1769-1776页

作者： gao Haiyan guo Fangqiu feng feng YIN Junfa SONG Maoyong WANG Hailin State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Research Center of Modernization of Chinese Medicines Central South University Changsha 410083 China

Aristolochic acid （AA） is a known nephrotoxin and potential carcinogen, which can form covalent DNA adducts after metabolic activation in vivo and in vitro. A simple method for preparation and characterization of aristolochic acid-DNA adducts was developed. Four AA-adducts were synthesized by a direct reaction of AAI/AAII with 2′-deoxynucleosides. The reaction mixture was first cleaned-up and pre-concentrated using solid phase extraction （SPE）, and further purified by a reversed-phase high performance liquid chromatography （HPLC）. By the application of developed SPE procedure, matrices and byproducts in reaction mixture could be greatly reduced and adducts of high purity （more than 94% as indicated by HPLC） were obtained. The purified AA-DNA adducts were identified and characterized with liquid-electrospray ionization-quadrupole-time of flight-mass spectrometry （LC-ESI-Q-TOF-MS/MS） and LC-Diode array detector-fluorescence （LC-DAD-FL） analysis. This work provides a robust tool for possible large-scale preparation of AA-DNA adduct standards, which can promote the further studies on carcinogenic and mutagenic mechanism of aristolochic acids.

关键词： aristolochic acid DNA adducts solid phase extraction quadrupole time-of-flight tandem mass spectrometry

Ar-Ar geochronology of Late Mesozoic volcanic rocks from the Yanji area, NE China and tectonic implications

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Science China Earth Sciences 2007年第4期50卷 505-518页

作者： LI ChaoWen guo feng FAN WeiMing gao Xiaofeng Key Laboratory of Marginal Sea Geology Guangzhou institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Graduate University of the Chinese Academy of Sciences Beijing 100039China

Ar-Ar dating results of late Mesozoic-Cenozoic volcanic rocks from the Yanji area, NE China provide a new volcano-sedimentary stratigraphic framework. The previously defined “Triassic-Jurassic” volcanic rocks (including those from Sanxianling, Tuntianying, Tianqiaoling and Jingouling Fms.) were erupted during 118―106 Ma, corresponding to Early Cretaceous. The new eruption age span is slightly younger than the main stage (130―120 Ma) of the extensive magmatism in the eastern Central Asian Orogenic Belt and its adjacent regions. Subduction-related adakites occurring in the previously defined Quanshuicun Fm. were extruded at ca. 55 Ma. Based on these new Ar-Ar ages, the late Mesozoic to Palaeocene volcano-sedimentary sequences is rebuilt as: Tuopangou Fm., Sanxianling/Tuntianying Fm. (118―115 Ma), Malugou/Tianqiaoling Fm. (K1), Huoshanyan/Jingouling Fm. (108―106 Ma), Changcai Fm. (K2), Quanshuicun Fm. (~55 Ma) and Dalazi Fm. Our results suggest that subduction of the Pa- laeo-Pacific Ocean beneath the East Asian continental margin occurred during 106 to 55 Ma, consistent with the paleomagnetic observations and magmatic records which indicated that the Izanagi-Farallon ridge subduction beneath the southwestern Japan took place during 95―65 Ma.

关键词： Ar-Ar geochronology Late Mesozoic volcanic rocks tectonic implications Yanji area

The organization,regulation,and biological functions of the synaptonemal complex

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Asian Journal of Andrology 2021年第6期23卷 580-589页

作者： feng-guo Zhang Rui-Rui Zhang Jin-Min gao Institute of Biomedical Sciences College of Life SciencesKey Laboratory of Animal Resistance Biology of Shandong ProvinceShandong Normal UniversityJinan 250014China

The synaptonemal complex(SC)is a meiosis-specific proteinaceous macromolecular structure that assembles between paired homologous chromosomes during meiosis in various *** SC has a highly conserved ultrastructure and plays critical roles in controlling multiple steps in meiotic recombination and crossover formation,ensuring accurate meiotic chromosome *** studies in different organisms,facilitated by advances in super-resolution microscopy,have provided insights into the macromolecular structure of the SC,including the internal organization of the meiotic chromosome axis and SC central region,the regulatory pathways that control SC assembly and dynamics,and the biological functions exerted by the SC and its *** review summarizes recent discoveries about how the SC is organized and regulated that help to explain the biological functions associated with this meiosis-specific structure.

关键词： chromosome axis chromosome segregation crossover meiosis meiotic recombination reproduction synapsis synaptonemal complex

Accurate design of spatially separated double active site in Bi_(4)NbO_(8)Cl single crystal to promote Z-Scheme photocatalytic overall water splitting

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Journal of Energy Chemistry 2023年第12期87卷 568-582,I0014页

作者： Kailong gao Hongxia guo Yanan Hu Hongbin He Mowen Li Xiaoming gao feng Fu Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China Yanneng-Yanda Comprehensive Energy Industry Technology Research Institute Shaanxi Modern Industrial College of Green and Efficient Utilization of Energy ResourcesShaanxi Collaborative Innovation Center of Clean Utilization of Low Rank CoalShaanxi Key Laboratory of Chemical Reaction EngineeringDepartment of Chemistry and Chemical EngineeringYan’an UniversityYan’an 716000ShaanxiChina

The efficiency of photocatalytic overall water splitting was mainly limited by the slow reaction kinetics of water *** to design effective surface active site to overcome the slow water oxidation reaction was a major ***,we propose a strategy to accelerate surface water oxidation through the fabrication spatially separated double active ***/Bi_(4)NbO_(8)Cl-OVs photocatalyst with spatially separated double active site was prepared by hydrogen reduction photoanode deposition *** to the high matching of the spatial loading positions of FeCoPi and OVs with the photogenerated charge distribution of Bi_(4)NbO_(8)Cl and corresponding reaction mechanisms of substrate,the FeCoPi and OVs on the(001)and(010)crystal planes of Bi_(4)NbO_(8)Cl photocatalyst provided surface active site for water oxidation reaction and electron shuttle reaction(Fe^(3+)/Fe^(2+)),*** visible light irradiation,the evolution O_(2)rate of FeCoPi/Bi_(4)NbO_(8)Cl OVs was 16.8μmol h^(-1),as 32.9 times as Bi_(4)NbO_(8)***,a hydrogen evolution co-catalyst PtRu@Cr_(2)O_(3)was prepared by sequential photodeposition *** to the introduction of Ru,the Schottky barrier between PbTiO_(3)and Pt was effectively reduced,which promoted the transfer of photogenerated electrons to PtRu@Cr_(2)O_(3)thermodynamically,the evolution H_(2)rate on PtRu@Cr_(2)O_(3)/PbTiO_(3)increased to 664.8 *** based of the synchronous enhancement of the water oxidation performance on FeCoPi/Bi_(4)NbO_(8)Cl-OVs and water reduction performance on PtRu@Cr_(2)O_(3)/PbTiO_(3),a novel Z-Scheme photocatalytic overall water splitting system(FeCoPi/Bi_(4)NbO_(8)Cl-OVs)mediated by Fe^(3+)/Fe^(2+)had successfully *** visible light irradiation,the evolution rates of H_(2)and O_(2)were 2.5 and 1.3μmol h^(-1),*** work can provide some reference for the design of active site and the controllable synthesis of OVs spatial *** the other hand,the hydr

关键词： Spatially separated double active sites FeCoPi/Bi_(4)NbO_(8)Cl-OVs Photocatalytic water oxidation Photocatalytic hydrogen evolution Hydrogen evolution co-catalyst PtRu@Cr_(2)O_(3) Z-Scheme photocatalytic overall water splitting system

New process for treating boron-bearing iron ore by flash reduction coupled with magnetic separation

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 473-484页

作者： Qipeng Bao Lei guo Hong Yong Sohn Haibin Zuo feng Liu Yongliang gao Zhancheng guo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Department of Materials Science&Engineering University of UtahUtah 84112USA China ENFI Engineering Corporation Beijing 100038China

Boron is an important industrial raw material often sourced from minerals containing different compounds that cocrystallize,which makes it difficult to separate the mineral phases through conventional *** study proposed a new treatment called flash reduction-melting separation(FRMS)for boron-bearing iron *** this method,the concentrates were first flash-reduced at the temperature under which the particles melt,and the slag and the reduced iron phases disengaged at the particle *** reduc-tion and melting effects were achieved above 1550℃.The B_(2)O_(3) content in the separated slag was over 18wt%,and the B content in the iron was less than 0.03wt%.The proposed FRMS method was tested to investigate the effects of factors such as ore particle size and tem-perature on the reduction and melting steps with and without pre-reducing the raw *** mineral phase transformation and morphology evolution in the ore particles during FRMS were also comprehensively analyzed.

关键词： ludwigite boron-bearing iron concentrate flash reduction melting separation boron