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China Foundry 2024年第5期21卷 546-554页

作者： Xiang-feng Ma Xin Ding en-lai liu Rui-run Chen Xin-xiu Wang Yong Zhang and Jing-jie Guo National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China School of Materials Science and engineering Shandong University of Science and TechnologyQingdao 266500ShandongChina AECC Harbin Dongan Engine Co.Ltd.Harbin 150001China

Ti-V-based alloys are proved of huge potential in storing hydrogen,but the incomplete reversible hydrogen storage capacity caused by overstability of V hydride has limited the large-scale *** this study,Ti_(32)V_(40+x)Fe_(23-x)Mn_(5)(x=0,4,8,12,at.%)alloys were designed,and the effects of V/Fe ratio on phase constitution and hydrogen storage properties were *** main phase of the alloys is body-centered cubic(BCC)phase,and the lattice constants of the BCC phase decrease with the decrease of V/Fe ***,C14 Laves phase exists in alloys with a Fe content of 19at.%to 23at.%.For hydrogenation,the C14 Laves phase can accelerate the hydrogen absorption rate,but the hydrogen absorption capacity is *** the decrease of V/Fe ratio,the hydride gradually *** to its large lattice constant and high hydrogen absorption phase content,the Ti_(32)V_(52)Fe_(11)Mn_(5)alloy shows the most enhanced hydrogen storage properties with hydrogenation and dehydrogenation capacities of 3.588wt.%at 298 K and 1.688wt.%at 343 K,*** hydrogen absorption capacity of this alloy can be reserved to 3.574wt.%after 20 cycles of hydrogen absorption and desorption.

关键词： hydrogen storage Ti-based alloy lattice constant BCC phase

Study of electromagnetic characteristics of stress distribution and sudden changes in the mining of gob-surrounded coal face

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Journal of China University of Mining and Technology 2008年第1期18卷 1-5页

作者： WANG en-yuan liu Xiao-fei ZHAO en-lai liu Zhen-tang School of Mining and Safety engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

The incidence of dynamic coal or rock disasters is closely related to the distribution of stress in the surrounding rock. Our experiments show that electromagnetic radiation （EMR） signals are related to the state of stress of a coal body. The higher the stress, the more intense the deformation and fractures of a coal body and the stronger the EMR signals. EMR signals reflect the degrees of concentrated stress of a coal body and danger of a rock burst. We selected EMR intensity as the test index of the No.237 gob-surrounded coal face in the Nanshan coal mine. We tested the EMR characteristics of the stress distribution on the strike, on the incline and in the interior of the coal body. The EMR rule of rock bursts, caused by sudden changes in stress, is analyzed. Our research shows that EMR technology can be not only used to test qualitatively the stress distribution of the surrounding rock, but also to predict a possible occurrence of rock burst. Based on this, effective distress measures are used to eliminate or at least weaken the incidence of rock bursts. We hooe that safetv in coalmines will be enhanced.

关键词： gob-surrounded coal face stress distribution sudden stress change rock burst electromagnetic radiation (EMR)

Experimental and numerical simulation study on the erosion behavior of the elbow of gathering pipeline in shale gas field

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Petroleum Science 2024年第2期21卷 1257-1274页

作者： en-Bin liu Shen Huang Ding-Chao Tian lai-Min Shi Shan-Bi Peng He Zheng Petroleum engineering School Southwest Petroleum UniversityChengdu 610500SichuanChina Chongqing Natural Gas Sales Center Natural Gas BranchSinopecChongqing400023China Zhejiang Zheneng Natural Gas Operation Co. Ltd.Hangzhou 310000ZhejiangChina School of Civil engineering and Architecture Southwest Petroleum UniversityChengdu 610500SichuanChina Louisiana Tech Univ Trenchless Technol Ctr599 Dan Reneau DrRustonLA71270USA Southwest Oil and Gas Field Branch Natural Gas Research Institute Chengdu 610213SichuanChina

During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow of the gathering pipeline in the Changning Shale Gas Field as an example to test the erosion rate and material removal mechanism of the test piece at different angles of the elbow through experiments and compares the four erosion models with the experimental results. Through analysis, it is found that the best prediction model for quartz sand-carbon steel erosion is the Oka model. Based on the Oka model, FLUenT software was used to simulate and analyze the law of erosion of the elbow of the gas gathering pipeline under different gas flow velocities, gas gathering pressure, particle size, length of L1,and bending directions of the elbow. And a spiral pipeline structure is proposed to reduce the erosion rate of the elbow under the same working conditions. The results show that this structure can reduce erosion by 34%.

关键词： Shale gas Gas gathering pipeline Elbow Erosion CFD

Power Flow Analytical Solutions and Multi-dimensional Voltage Stability Boundaries Based on Multivariate Quotient-difference Method

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CSEE Journal of Power and energy Systems 2024年第3期10卷 1168-1178页

作者： Chengxi liu Qiupin lai School of Electrical engineering and Automation Wuhan UniversityWuhan 430072China Hubei engineering and Technology Research Center for AC/DC Intelligent Distribution Network Wuhan 430072China IEEE

This paper proposes a novel Multivariate Quotient-Difference(MQD)method to obtain the approximate analytical solution for AC power flow ***,in the online environment,the power flow solutions covering different operating conditions can be directly obtained by plugging values into multiple symbolic variables,such that the power injections and consumptions of selected buses or areas can be independently *** method first derives a power flow solution through a Multivariate Power Series(MPS).Next,the MQD method is applied to transform the obtained MPS to a Multivariate Pad´e Approximants(MPA)to expand the Radius of Convergence(ROC),so that the accuracy of the derived analytical solution can be significantly *** addition,the hypersurface of the voltage stability boundary can be identified by an analytical formula obtained from the coefficients of *** direct method for power flow solutions and voltage stability boundaries is fast for many online applications,since such analytical solutions can be derived offline and evaluated online by only plugging values into the symbolic variables according to the actual operating *** proposed method is validated in detail on New england 39-bus and IEEE 118-bus systems with independent load variations in multi-regions.

关键词： Analytical power flow solution multivariate power series multivariate Padéapproximants multivariate quotient-difference multi-dimensional voltage stability boundary

Remote sensing image encryption algorithm utilizing 2D Logistic memristive hyperchaotic map and SHA-512

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Science China(Technological Sciences) 2024年第5期67卷 1553-1566页

作者： lai Qiang liu Yuan YANG Liang School of Electrical and Automation engineering East China Jiaotong UniversityNanchang330013China

The two-dimensional Logistic memristive hyperchaotic map(2D-LMHM)and the secure hash SHA-512 are the foundations of the unique remote sensing image encryption algorithm(RS-IEA)suggested in this *** proposed map is formed from the improved Logistic map and the memristor,which has wide phase space and hyperchaotic range and is exceptionally excellent to be utilized in specific *** proposed image algorithm uses the permutation-assignment-diffusion *** generates two position matrices in a progressive manner to achieve an efficient random exchange of pixel positions,assignment is carried through on the image pixels of the permutated image to entirely remove the original image information,strengthening the relationship between permutation and diffusion,and loop diffusion in two different directions can use subtle changes of pixels to affect the whole *** random key and plain-image SHA-512 hash values are used to produce an additional key,which is then utilized to figure out the permutation parameters and the initial value of a chaotic *** experimental results with the average NPCR=99.6094%(NPCR:number of pixels change rate),average UACI=33.4638%(UACI:unified average changing intensity),100%pass rate of the targets in the test set,the average correlation coefficient is 0.00075,and the local information entropy is 7.9025,which shows that the algorithm is able to defend against a variety of illegal attacks and provide more trustworthy protection than some of the existing state-of-the-art algorithms.

关键词： chaos memristive hyperchaotic map remote sensing SHA-512 image encryption RS-IEA

Improved Segmented Belief Propagation List Decoding for Polar Codes with Bit-Flipping

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China Communications 2024年第3期21卷 19-36页

作者： Mao Yinyou Yang Dong liu Xingcheng Zou en School of Electronics and Information Technology(SEIT) Sun Yat-sen University(SYSU)Guangzhou 510006China School of Information Science Guangzhou Xinhua UniversityGuangzhou 510520China Southern Marine Science and engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China

Belief propagation list(BPL) decoding for polar codes has attracted more attention due to its inherent parallel nature. However, a large gap still exists with CRC-aided SCL(CA-SCL) *** this work, an improved segmented belief propagation list decoding based on bit flipping(SBPL-BF) is proposed. On the one hand, the proposed algorithm makes use of the cooperative characteristic in BPL decoding such that the codeword is decoded in different BP decoders. Based on this characteristic, the unreliable bits for flipping could be split into multiple subblocks and could be flipped in different decoders simultaneously. On the other hand, a more flexible and effective processing strategy for the priori information of the unfrozen bits that do not need to be flipped is designed to improve the decoding convergence. In addition, this is the first proposal in BPL decoding which jointly optimizes the bit flipping of the information bits and the code bits. In particular, for bit flipping of the code bits, a H-matrix aided bit-flipping algorithm is designed to enhance the accuracy in identifying erroneous code bits. The simulation results show that the proposed algorithm significantly improves the errorcorrection performance of BPL decoding for medium and long codes. It is more than 0.25 d B better than the state-of-the-art BPL decoding at a block error rate(BLER) of 10^(-5), and outperforms CA-SCL decoding in the low signal-to-noise(SNR) region for(1024, 0.5)polar codes.

关键词： belief propagation list(BPL)decoding bit-flipping polar codes segmented CRC

Comprehensive DNA barcode reference library and optimization of genetic divergence threshold facilitate the exploration of species diversity of green lacewings (Neuroptera: Chrysopidae)

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Insect Science 2024年第2期31卷 613-632页

作者： Yan lai Kaiyu Li Xingyue liu Deparment of entomology Cllege of Plant ProtectionChina Agricultural UniversityBejingChina College of Bioogical Sciencs China Agricultural UniversityBeijingChina

Chrysopidae are a family of Neuroptera of significant importance in biocontrol against agricultural pests because of their predatory ***,the taxonomy of Chrysopidae lacks a comprehensive revision,which impedes the exploration of species diversity as well as the selection and the conservation of green lacewings as biocontrol *** have established a DNA barcode reference library of the Chinese green lacewings based on an approximately complete sampling(95.63%)in 25 of the 34 provincial regions in China,comprising 1119 barcodes of 25 genera and 197 species(representing 85%genera and 43.62%species from China).Combining other 1049 high quality green lacewing DNA barcodes,we first inferred the optimal threshold of interspecific genetic divergence(1.87%)for successful species identification in multiple simulated scenarios based on present *** further inferred the threshold of genetic divergence(7.77%)among genera with biocontrol *** inference and performance of the threshold appears to be mainly associated with the completeness of sampling,the proportion of closely related species,and the analytical *** new combinations,Apertochrysa platypa(Yang&Yang,1991)***.,Apertochrysa shennongana(Yang&Wang,1990)***.,Apertochrysa pictifacialis(Yang,1988)***.,Apertochrysa helana(Yang,1993)***.,Plesiochrysa rosulata(Yang&Yang,2002)***.,and Signochrysa hainana(Yang&Yang,1991),are proposed according to integrative species *** library and optimal threshold will effectively facilitate the exploration of species diversity of green *** study also provides a methodological reference in molecular delimitation of other insects.

关键词： Chrysopidae DNA barcode genetic distance optimal threshold species delimitation

enhanced Fenton-like process over Cu/L(+)-ascorbic acid co-doping mesoporous silica for toxicity reduction of emerging contaminants

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Frontiers of environmental Science & engineering 2024年第4期18卷 49-60页

作者： Yuhang liu Wenxuan Deng Xiaojun Wu Chun Hu lai Lyu Key Laboratory for Water Quality and Conservation of the Pearl River Delta(Ministry of Education) Institute of Environmental Research at Greater BayGuangzhou UniversityGuangzhou 510006China

Effective removal of emerging contaminants(ECs)to minimize their impacts on human health and the natural environment is a global *** the removal of ECs in water,we fabricated a seaweed spherical microsphere catalyst with Cu cation-πstructures by in situ doping of Cu species and ascorbic acid in mesoporous silica(Cu-C-MSNs)via a hydrothermal *** results indicate that bisphenol A(BPA)is substantially degraded within 5 min under natural conditions,with its biological toxicity considerably ***,industrial wastewater could also be effectively purified by Cu-C-MSNs/H_(2)O_(2) *** presence of metal sites and the complexation of ECs via cation-πinteraction andπ-πstacking on the catalyst surface were directly responsible for the polarization distribution of electrons,thus activating H_(2)O_(2) and dissolved oxygen(DO).The removal of contaminants could be attributed primarily to 1)the activation of H_(2)O_(2) into ^(·)OH to attack the contaminants and 2)self-cleavage because of the transfer of electrons from the contaminants to the *** study provides an innovative solution for the effective treatment of ECs and has positive implications for easing global environmental crises.

关键词： Cation-πstructures Polarization electric field Fenton-like process Contaminants cleavage

Comparison of antimony and arsenic behaviour at the river-lake junction in the middle of the Yangtze River Basin

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Journal of environmental Sciences 2024年第2期136卷 189-200页

作者： Huiji liu Wei Zeng Ziyang lai Mengchang He Chunye Lin Wei Ouyang Xitao liu State Key Laboratory of Water environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China Advanced Interdisciplinary Institute of environment and Ecology Beijing Normal UniversityZhuhai 519087China

As typical metalloid toxic elements widely distributed in environmental media,the geochemical behaviour of antimony(Sb)and arsenic(As)affects environmental *** selected the surface waters and sediments at the river-lake junction of Dongting Lake as the research objects,analysed the concentration and chemical partitioning of Sb and As,assessed its contamination and ecological risk levels,and discussed its sources and potential influencing *** concentrations of dissolved Sb and As in surface waters were low(entrations of Sb and As in surface sediments were 2.49-22.65mg/kg and 11.10-136.34 mg/kg,*** and As in sediments were mainly enriched in the fraction of residues,but the proportion of As in bioavailability was significantly higher than that of *** the contamination level of Sb was higher than that of As,the risk assessment code(RAC)showed that the ecological risk level of As was higher than that of *** erosion and mining activities(in the midstream of Zijiang River)were the main contaminated sources of Sb,while As was affect mainly by rainwater *** contamination and ecological risk of Sb in the inlet of the Zijiang River should receive considerable attention,while those of As in the inlet of the Xiangjiang River should also be seriously *** study highlights the need for multi-index-based assessments of contamination and ecological risk and the importance of further studies on the environmental behaviour of metalloids in specific hydrological conditions,such as river-lake junctions.

关键词： Contamination Ecological risks Antimony(Sb) Arsenic(As) River-lake junction Dongting Lake

Immediate implantation of ultrafine fiber slow-release system based on cell electrospinning to induce osteogenesis of mesenchymal stem cells

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Regenerative Biomaterials 2024年第2期3卷 76-87页

作者： Tao Lu Long Yang Zhuoyang Li Yin liu Shun'en Xu Chuan Ye Department of Orthopaedics The Affliated Hospital of Guizhou Medical UniversityGuiyang 550004China Department of Orthopaedics The First People's Hospital of GuiyangGuiyang 550004China Center for Tissue engineering and Stem Cell Research Guizhou Medical UniversityGuiyang 550004China Department of Otolaryngology Head and Neck Surgery Xinqiao HospitalArmy Medical University(Third Military Medical University)Chongqing 400037China Department of Dental implant Stomatological Hospital of GuiyangGuiyang 550000China

This study presents the development and evaluation of a poly(3-hydroxybutyrate-co-4-hydroxybutyrate)(P34HB)ultrafine fiber slow-release system for in vivo osteogenic induction of human umbilical cord mesenchymal stem cells(HUCMSCs).Utilizing dual-nozzle and cell electrospinning techniques,the system encapsulates L-ascorbic acid-2-phosphate magnesium(AsP),βB-glycerophosphate sodium and dexamethasone(DEX)within the'fbers,ensuring sustained osteogenic *** scaffold's morphology,characterization,hydrophilicity,mechanical properties and cellular behavior were *** subcutaneous implantation in rabbits was con-ducted to observe its ectopic osteogenic induction *** fabricated P34HB ultrafine fiber slow-release *** ization *** distribution of HUCMSCs and inducing components within the scaffold,with no chemical reactions affecting the active *** vitro tests showcased a prolonged release of DEX and ASP,while biocompatibility assays highlighted the scaffold's suitability for cellular *** Red,type I collagen,and osteopontin(OPN)staining verifed the scaffold's potent osteogenic induction effect on ***,immediate implantation into New Zealand White rabbits led to significant new bone formation within 8 *** findings underscore the system's potential for immediate in vivo implantation without prior in vitro induction,marking a promising advancement in bone tissue engineering.

关键词： bone tissue engineering cell electrospinning in vivo induction immediate implantation biomaterials