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Securing offshore resources development: A mathematical investigation into gas leakage in long-distance flexible pipes

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Petroleum Science 2024年第4期21卷 2734-2744页

作者： xiang-An lu Liang-Liang Jiang Jian-Sheng Zhang Min-Gui Wang Guangling College of Yangzhou University Department of Chemical and Petroleum Engineering University of Calgary Department of Energy and Power Engineering Tsinghua University

Gas flexible pipes are critical multi-layered equipment for offshore oil and gas development. Under high pressure conditions, small molecular components of natural gas dissolve into the polymer inner liner of the flexible pipes and further diffuse into the annular space, incurring annular pressure build-up and/or production of acidic environment, which poses serious challenges to the structure and integrity of the flexible pipes. Gas permeation in pipes is a complex phenomenon governed by various factors such as internal pressure and temperature, annular structure, external temperature. In a long-distance gas flexible pipe, moreover, gas permeation exhibits non-uniform features, and the gas permeated into the annular space flows along the metal gap. To assess the complex gas transport behavior in long-distance gas flexible pipes, a mathematical model is established in this paper considering the multiphase flow phenomena inside the flexible pipes, the diffusion of gas in the inner liner, and the gas seepage in the annular space under varying permeable properties of the annulus. In addition, the effect of a variable temperature is accounted. A numerical calculation method is accordingly constructed to solve the coupling mathematical equations. The annular permeability was shown to significantly influence the distribution of annular pressure. As permeability increases, the annular pressure tends to become more uniform, and the annular pressure at the wellhead rises more rapidly. After annular pressure relief followed by shut-in, the pressure increase follows a convex function. By simulating the pressure recovery pattern after pressure relief and comparing it with test results, we deduce that the annular permeability lies between 123 and 512 m D. The results help shed light upon assessing the annular pressure in long distance gas flexible pipes and thus ensure the security of gas transport in the emerging development of offshore resources.

关键词： Offshore resources development Transport security Long-distance flexible pipes Gas leakage Heat and mass transfer model Finite difference calculation

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Vanadium(V) Complexes Containing Unsymmetrical N-Heterocyclic Carbene Ligands: Highly Efficient Synthesis and Catalytic Behavior towards Ethylene/Propylene Copolymerization

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Chinese Journal of Polymer Science 2024年第1期42卷 32-41,I0006页

作者： Yi-Cong Wang Hui Zhat pei-Yi Cheng Shu Zhang xiang-Wei Liu Yi-Xian Wu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBejing 100029China

The highly efficient method has been developed for the synthesis of NHC·VOCl_(3) containing symmetrical or unsymmetrical Nheterocyclic carbene(NHC) ligands by the transmetallation reaction of NHC·AgCl with VOCl_(3).The total isolated yield of VOCl_(3)[1,3-(2,4,6-Me_(3)C_(6)H_(2))_(2)(NCH=)_(2)C:](V4') reached 86% by transmetallation reaction,which is much higher than that(48%) by direct coordination *** methodology has also been used to synthesize the novel vanadium complexes containing unsymmetrical NHC ligands of VOCl_(3)[PhCH_(2)NCH=CHNR)C:](V5',R=2,4,6-Me_(3)C_(6)H_(2);V6',R=2,4-Me_(2)-6-Ph-C_(6)H_(2);V7',R=2,6-^(i)Pr_(2)-C_(6)H_(3)) with high yield,which could not be obtained by direct coordination *** catalytic activity and copolymerization ability would be improved by introducing unsymmetrical NHC ligands due to their less steric bulky *** vanadium complex V5' containing unsymmetrical NHC ligand exhibits higher catalytic activity(3.7×10^(5)g_(copolymer)·mol^(-1) of V·h^(-1)) than that of V4' containing symmetrical NHC ***,the higher propylene incorporation ratio(45.6 mol%) in the copolymers of ethylene with propylene could be obtained by using V5' than that(39.9%) by using V4'.The results would provide a highly efficient strategy for the synthesis of early transition metal complexes containing versitile NHC ligands,affording the catalyst with both high catalytic activity and copolymerization ability for the synthesis of high performance polyolefin elastomers.

关键词： Vanadium complex N-heterocyclic carbene ligand Transmetallation reaction Copolymerization of ethylene with propylene

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Six million Q factor micro fused silica shell resonator with teeth-like tines released by femtosecond laser-assisted chemical etching

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Science China(Technological Sciences) 2024年第6期67卷 1923-1932页

作者： ZHAO Tao SHI Yan lu Kun XI xiang WU XueZhong XIAO DingBang College of Intelligence Science and Engineering National University of Defense TechnologyChangsha410073China

The quality factor(Q factor)is a crucial performance parameter for *** this paper,a novel release method for highquality micro fused silica shell resonators with teeth-like tines with good surface morphology is *** method is based on femtosecond laser-assisted chemical ***,the optimal energy range of femtosecond laser modification is obtained through mechanism ***,the optimal parameters for a straight line and arc pattern are determined by optimizing the average output power,processing speed,and processing *** results demonstrate why edge breakage in rounded corners is easy under different ***,according to these conclusions,the processing is performed on a micro fused silica shell resonator with a Q factor exceeding 6 *** addition,subsurface damage is rare throughout the fabrication process,and the surface roughness of the released cross section reaches the nanometer *** improved Q factor helps suppress mechanical thermal noise and reduce zero bias and zero bias drift,constituting the primary method for enhancing the performance of the resonant gyroscope.

关键词： micro hemispherical resonator fused silica laser-assisted chemical etching quality factor

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Simplified Cluster Voltage Balancing Control Based on Zero-sequence Voltage Injection for Star-connected Cascaded H-bridge STATCOM

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CSEE Journal of Power and Energy Systems 2024年第5期10卷 2255-2264页

作者： Kai Hu Guoliang Zhao Daorong lu Zhengang lu Nianwen xiang Shulai Wang Jintian Lin School of Electrical Engineering and Automation Hefei University of TechnologyHefei 230009China School of Electrical and Automation Engineering Nanjing Normal UniversityNanjing 210023China State Grid Smart Grid Research Institute(SGRI) Beijing 102209China Power grid Technology Center of State Grid Zhejiang Electric Power Research Institute Hangzhou 310004China

The cluster DC voltage balancing control adopting zero-sequence voltage injection is appropriate for the starconnected cascaded H-bridge STATCOM because no zerosequence currents are generated in the three-phase three-wire ***,as the zero-sequence voltage is expressed in trigonometric form,traditional control methods involve many complicated operations,such as the square-root,trigonometric operations,and inverse tangent *** simplify cluster voltage balancing control,this paper converts the zero-sequence voltage to the dq frame in a DC representation by introducing a virtually orthogonal variable,and the DC components of the zero-sequence voltage in the dq frame are regulated linearly by proportional integral regulators,rather than being calculated from uneven active powers in traditional *** removes all complicated ***,this paper presents simulation and experimental results for a 400 V±7.5 kvar star-connected STATCOM,in balanced and unbalanced scenarios,thereby verifying the effectiveness of the proposed control.

关键词： Cluster DC voltage balancing control DC representation of zero-sequence voltage star-connected cascaded H-bridge STATCOM zero-sequence voltage injection

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Isoindigo nanoparticles for photoacoustic imaging-guided tumor photothermal therapy

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Chinese Journal of Chemical Engineering 2024年第8期72卷 19-25页

作者： Yao pei Ran Wang xiang Rong xiang Xia Hexiang Wang Zongwei Zhang Tian Qiu Saran Long Jianjun Du Jiangli Fan Wen Sun Xiaojun Peng State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical EngineeringDalian University of TechnologyDalian 116024China Ningbo Institute of Dalian University of Technology Ningbo 315016China

The key factor in photothermal therapy lies in the selection of photothermal *** photothermal agents generally have problems such as poor photothermal stability and low photothermal conversion ***,we have designed and synthesized an isoindigo(IID)*** used isoindigo as the molecular center and introduced common triphenylamine and methoxy groups as *** order to improve the photothermal stability and tumor targeting ability,we encapsulated IID into *** a result,the nanoparticles exhibited high photothermal stability and photothermal conversion efficiency(67%)upon 635 nm laser ***,the nanoparticles demonstrated a significant inhibitory effect on live tumors in photothermal therapy guided by photoacoustic imaging and provided a viable strategy to overcome the treatment challenges.

关键词： Photothermal therapy Isoindigo Nanoparticles Photoacoustic imaging

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Performance-control-orientated hybrid metal additive manufacturing technologies:state of the art,challenges,and future trends

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International Journal of Extreme Manufacturing 2024年第3期6卷 274-328页

作者： Jiming Lv Yuchen Liang xiang Xu Gang Xu Hongmei Zhang Haifei lu Kaiyu luo Jie Cai Jinzhong lu School of Mechanical Engineering Jiangsu UniversityZhenjiang 212013People’s Republic of China School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003People’s Republic of China

Metal additive manufacturing(AM)technologies have made significant progress in the basic theoretical field since their invention in the ***,performance instability during continuous processing,such as thermal history,residual stress accumulation,and columnar grain epitaxial growth,consistently hinders their broad application in standardized industrial *** overcome these challenges,performance-control-oriented hybrid AM(HAM)technologies have been *** technologies,by leveraging external auxiliary processes,aim to regulate microstructural evolution and mechanical properties during metal *** paper provides a systematic and detailed review of performance-control-oriented HAM technology,which is categorized into two main groups:energy field-assisted AM(EFed AM,***,electromagnetic,and heat)technologies and interlayer plastic deformation-assisted AM(IPDed AM,*** shock peening,rolling,ultrasonic peening,and friction stir process)*** review covers the influence of external energy fields on the melting,flow,and solidification behavior of materials,and the regulatory effects of interlayer plastic deformation on grain refinement,nucleation,and ***,the role of performance-control-oriented HAM technologies in managing residual stress conversion,metallurgical defect closure,mechanical property improvement,and anisotropy regulation is thoroughly reviewed and *** review concludes with an analysis of future development trends in EFed AM and IPDed AM technologies.

关键词： hybrid additive manufacturing in-situ/interlayer plastic deformation auxiliary energy fields microstructure customization mechanical properties enhancement

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Wideband chaos generation using a VCSEL with intensity modulation optical injection for random number generation

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Science China(Information Sciences) 2024年第6期67卷 457-458页

作者： Yu HUANG Shuangquan GU Yuhang FENG Yigong YANG Shuiying xiang pei ZHOU Nianqiang LI School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University State Key Laboratory of Integrated Service Networks Xidian University Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China Soochow University

Physical random numbers have been widely used in modern network society,such as the generation of cryptographic keys for classical and quantum cryptography systems[1].Among the many sources of physical entropy,chaotic semiconductor lasers have attracted wide attention due to their desired characteristics including larger bandwidth,low cost,and monolithic integration[2].

关键词： Optical signal processing

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Quantum weak force sensing with squeezed magnomechanics

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 23-32页

作者： Qian Zhang Jie Wang Tian-xiang lu Ran Huang Franco Nori Hui Jing Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China Theoretical Quantum Physics Laboratory Cluster for Pioneering ResearchRIKENWako-shi 351-0198Japan Center for Quantum Computing RIKENWako-shi 351-0198Japan Department of Physics University of MichiganAnn Arbor 48109-1040USA College of Physics and Electronic Information Gannan Normal UniversityGanzhou 341000China Academy for Quantum Science and Technology Zhengzhou University of Light IndustryZhengzhou 450002China

Cavity magnomechanics,exhibiting remarkable experimental tunability,rich magnonic nonlinearities,and compatibility with various quantum systems,has witnessed considerable advances in recent ***,the potential benefits of using cavity magnomechanical(CMM)systems in further improving the performance of quantum-enhanced sensing for weak forces remain largely *** we show that,by squeezing the magnons,the performance of a quantum CMM sensor can be significantly enhanced beyond the standard quantum limit(SQL).We find that,for comparable parameters,two orders of magnitude enhancement in the force sensitivity can be achieved in comparison with the case without magnon ***,we obtain the optimal parameter regimes of homodyne angle for minimizing the added quantum *** findings provide a promising approach for highly tunable and compatible quantum force sensing using hybrid CMM devices,with potential applications ranging from quantum precision measurements to quantum information processing.

关键词： quantum force sensing cavity magnomechanics magnon Kerr effect

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3D core-shell nanofibers framework and functional ceramic nanoparticles synergistically reinforced composite polymer electrolytes for high-performance all-solid-state lithium metal battery

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Chinese Chemical Letters 2024年第8期35卷 425-432页

作者： Hengying xiang Nanping Deng lu Gao Wen Yu Bowen Cheng Weimin Kang State Key Laboratory of Separation Membranes and Membrane Processes Tiangong UniversityTianjin 300387China School of Textile Science and Engineering Tiangong UniversityTianjin 300387China

Satisfactory ionic conductivity,excellent mechanical stability,and high-temperature resistance are the prerequisites for the safe application of solid polymer electrolytes(SPEs)in all-solid-state lithium metal batteries(ASSLMBs).In this study,a novel poly(m-phenylene isophthalamide)(PMIA)-core/poly(ethylene oxide)(PEO)-shell nanofiber membrane and the functional Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)ceramic nanopar-ticle are simultaneously introduced into the PEO-based SPEs to prepare composite polymer electrolytes(CPEs).The core PMIA layer of composite nanofibers can greatly improve the mechanical strength and thermal stability of the CPEs,while the shell PEO layer can provide the 3D continuous transport channels for lithium *** addition,the introduction of functional LLZTO nanoparticle not only reduces the crys-tallinity of PEO,but also promotes the dissociation of lithium salts and releases more Li^(+)ions through its interaction with the Lewis acid-base of anions,thereby overall improving the transport of lithium ***,the optimized CPEs present high ionic conductivity of 1.38×10^(−4)S/cm at 30℃,signifi-cantly improved mechanical strength(8.5 MPa),remarkable thermal stability(without obvious shrinkage at 150℃),and conspicuous Li dendrites blocking ability(>1800 h).The CPEs also both have good com-patibility and cyclic stability with LiFePO_(4)(>2000 cycles)and high-voltage LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811)(>500 cycles)*** addition,even at low temperature(40℃),the assembled LiFePO4/CPEs/Li bat-tery still can cycle *** novel design can provide an effective way to exploit high-performance solid-state electrolytes.

关键词： Composite polymer electrolytes Core-shell structured nanofiber Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)ceramic nanoparticle All-solid-state lithium metal batteries Outstanding thermal stability and electrochemical performance

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Solid-state NMR studies of proteins in condensed phases

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Magnetic Resonance Letters 2024年第3期4卷 1-10页

作者： Jiani xiang Xialian Wu Angelo L.Chu Junxia lu Key Laboratory of Industrial Fermentation(Ministry of Education) School of Life and Health SciencesHubei University of TechnologyWuhan430068China Interdisciplinary Institute of NMR and Molecular Sciences School of Chemistry and Chemical EngineeringThe State Key Laboratory of Refractories and MetallurgyWuhan University of Science and TechnologyWuhan430081China Thomas Jefferson High School for Science and Technology 6560 Braddock RdAlexandriaVA22312USA

Some proteins perform their biological functions by changing their material states through liquid-liquid phase *** phase separation,the protein condenses into a concentrated liquid phase and sometimes into a gel phase,changing its dynamic properties and intermolecular interactions,thereby regulating cellular *** the biological significance of this phenomenon has been widely recognized by researchers,there is still a lack of a comprehensive understanding of the structural and dynamic properties of the protein in the condensed *** this phase,molecules usually contain domains with varied dynamic properties and undergo intermediate *** angle spinning(MAS)solid-state NMR(SSNMR)experiments are very powerful in studying rigid protein polymers such as *** incorporation of solution-like experiments into SSNMR and the development of J-coupling based MAS SSNMR techniques extend its ability to study partially mobile segments of proteins in a condensed liquid or gel phase which are not visible by solution NMR or dipolar-coupling based ***,it has been applied in studying protein condensation and has provided very important information that is hard to obtain by other techniques.

关键词： Magic angle spinning(MAS)solid-state NMR(SSNMR) Protein condenses J-coupling based MAS SSNMR Liquid-liquid phase separation

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