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Large-aperture Telescope Tracking Control Based on Tim.-synchronization Strategy

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Research in Astronom. and Astrophysics 2024年第3期24卷 34-46页

作者： Yun Li Yu ye Shi-hai Yang Ling-Zhe Xu Jin Xu hai Wang Zhuang-Zhuang Deng Rui-Qiang Liu Xiao-Jie Gu Bo-Zhong Gu Nanjing Institute of Astronom.cal Optics&Technology Chinese Academy of SciencesNanjing 210042China CAS Key Laboratory of Astronom.cal Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China University of Chinese Academ. of Sciences Beijing 100049China

A tim.-synchronization strategy for packetized transm.ssion of target position about a large-aperture telescope observation control system.has been proposed in this *** with the existing telescope tracking strategy,the target position packing and sending strategy based on the tim. synchronization m.thod proposed in this paper has the advantages of high stability and ***,the telescope tracking observation control m.thod was elaborated in this paper,including the m.tion pattern during telescope ***,the strategy for packetizes transm.ssion of target positions based on tim.-synchronization is established and lists the detailed ***,the perform.nce of the tracking strategy is verified using the 2.5 m.telescope for the sim.lated uniform.speed star and the blind-tracking fixed star HIP 31216,*** test results show that the accuracy root m.an square of the tracking strategy proposed in this paper is less than 0".02 at 30 m.nutes,and the perform.nce is m.ch better than the design requirem.nt of 0".*** m.st im.ortant advantage of this tracking strategy is that the telescope can guarantee norm.l tracking for a certain period of tim. even if the hardware or software of the host com.uter is abnorm.l.

关键词： m.scellaneous-telescopes-m.thods observational-m.thods analytical

Detection of astrophysical gravitational wave sources by TianQin and LISA

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Science China(Physics,m.chanics & Astronom.) 2024年第5期67卷 123-163页

作者： Alejandro Torres-Orjuela Shun-Jia Huang Zheng-Cheng Liang Shuai Liu hai-Tian Wang Chang-Qing ye Yi-m.ng Hu Jianwei m.i m.E Key Laboratory of Tian Qin m.ssion Tian Qin Research Center for Gravitational PhysicsSchool of Physics and AstronomyFrontiers Science Center for Tian QinGravitational Wave Research Center of CNSASun Yat-Sen University(Zhuhai Campus)Zhuhai 519082China Departm.nt of Physics The University of Hong KongHong Kong 999077China Kavli Institute for Astronom. and Astrophysics Peking UniversityBeijing100871China

TianQin and LISA are space-based laser interferom.ter gravitational wave(GW)detectors planned to be launched in the *** detectors will detect low-frequency GWs around 10^(-2)Hz;however,Tian Qin is m.re sensitive to frequencies above this com.on sweet-spot while LISA is m.re sensitive to frequencies below 10^(-2)***,Tian Qin and LISA will be able to detect the sam. sources but with different accuracy depending on the source and its *** consider som. of the m.st im.ortant astrophysical sources—m.ssive black hole binaries,stellar-m.ss black hole binaries,double white dwarfs,extrem. m.ss ratio inspirals,light and heavy interm.diate m.ss ratio inspirals,as well as the stochastic gravitational background of astrophysical origin—that Tian Qin and LISA will be able to *** each of these sources,we analyze how far they can be detected(detection distance)and how well their param.ters can be m.asured(detection accuracy)using a Fisher m.trix *** com.are the results obtained by the three detection scenarios(Tian Qin alone,LISA alone,and joint detection by LISA and Tian Qin)highlighting the gains from.joint detection as well as the contribution of Tian Qin and LISA to a com.ined study of astrophysical *** particular,we consider the different orientations,lifetim.s,and duty cycles of the two detectors to explore how they can give a m.re com.lete picture when working together.

关键词： wave extrem. stochastic

Evaluation of the injection and plugging ability of a novel epoxy resin in cem.nt cracks

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Petroleum.Science 2024年第2期21卷 1211-1220页

作者： Guang-Yao Leng Wei Yan hai-m. ye Er-Dong Yao Ji-Bin Duan Zheng-Xian Xu Ke-Pei Li Jing-Ru Zhang Zhong Li State Key Laboratory of Petroleum.Resource&Prospecting China University of Petroleum(Beijing)Beijing102249China CNPC Liaohe Oilfield Gas Storage Co.LTD Panjin124000LiaoningChina CNOOC Research Institute Co. Ltd.Beijing100028China

Sustained casing pressure(SCP)is a crucial issue in the oil and gas production *** resins,exhibiting exceptional com.ressive strength,ductility,and shear bonding strength,have the potential to form.reliable *** injectivity and sealing capacity of the epoxy resin is crucial param.ters for the success of shallow rem.diation *** study aim.d to develop and assess a novel solid-free resin sealant as an alternative to Portland cem.nt for m.tigating fluid *** investigation evaluated the viscosity,com.ressive strength,and brittleness index of the epoxy resin sealant,as well as its tangential and norm.l shear strengths in conjunction with casing *** flow characteristics and sealing abilities of conventional cem.nt and epoxy resin were com.aratively analyzed in *** results showed that the application of a viscosity reducer facilitated control over the curing tim. of the epoxy resin,ranging from.1.5 to 6 h,and reduced the initial viscosity from.865.53 to 118.71 m.Pa,*** m.chanical properties of the epoxy resin initially increased with a rise in curing agent content before experiencing a m.nor *** epoxy resin containing 30%curing agent exhibited optim.l m.chanical *** a 14-day curing period,the epoxy resin's com.ressive strength reached81.37 m.a,2.12 tim.s higher than that of cem.nt,whereas the elastic m.dulus of cem.nt was 2.99 tim.s greater than that of the epoxy *** brittleness index of epoxy resin is only 3.42,dem.nstrating high flexibility and *** tangential and norm.l shear strengths of the epoxy resin exceeded those of cem.nt by 3.17 and 2.82 tim.s,*** a 0.5 m.-wide crack,the injection pressure of the epoxy resin rem.ined below 0.075 m.a,indicating superior injection and flow ***,the injection pressure of cem.nt surged dram.tically to 2.61 m.a within 5 *** breakthrough pressure of0.5 PV epoxy resin reached 7.53 m.a,decreasing the crack's perm.

关键词： Sustained casing pressure Epoxy resin sealant Curing agent Viscosity reducer m.chanical properties Crack sealing

Investigations of Water Flow Behaviors Induced by Local Tem.erature Variations through a Single Rough Fracture for the Enhanced Geotherm.l System.

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Journal of Therm.l Science 2024年第3期33卷 1055-1064页

作者： LI Jiawei ye Lin Departm.nt of Energy and Power Engineering Tsinghua UniversityBeijing100084China School of Power and Energy Northwestern Polytechnical UniversityXi’an710072China

In recent years,Enhanced Geotherm.l System.EGS)technologies have been applied to the geotherm.l resources production in the Hot Dry Rock(HDR).The core of EGS technologies is to adopt hydraulic fracturing in the reservoir to create a connected network of discrete fractures with the consideration of water as a working fluid for hydraulic fracturing and heat *** paper investigates the characteristics of water flow behaviors through a single rough fracture under different tem.erature and pressure conditions.A single fracture m.del with rough fracture surfaces is constructed and then characterized,and influences of the anisotropic factor on the average tortuosity and frictional resistance coefficient of water flow through a single fracture with rough surfaces have been com.ared and *** consideration of other im.acting factors(tem.erature,pressure,fracture roughness),the im.act of m.ss flow rate has also been *** sim.lation results present that changes of average tortuosity for water flow through a single rough facture are m.inly affected by *** can be observed that higher tem.erature leads to larger average tortuosity but the frictional resistance coefficient shows an opposite *** for pressure conditions,it is found that effects of pressure on average tortuosity and frictional resistance coefficient is very sm.ll,which can be neglected under high pressure ***,the average tortuosity shows a progressively linear relationship with the m.ss flow *** the contrary,the frictional resistance coefficient has a negative relationship with the m.ss flow *** is revealed that when the m.ss flow rate reaches a critical point,the influences of tem.erature on the frictional resistance coefficient will be *** of single rough fractures with different anisotropic factors show that values of average tortuosity and frictional resistance coefficient have positive relationships with the increase

关键词： single rough fracture tortuosity frictional resistance enhanced geotherm.l system

UWLPIPE:Ultra-wide Bandwidth Low-frequency Pulsar Data Processing Pipeline

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Research in Astronom. and Astrophysics 2024年第7期24卷 145-157页

作者： Ya-Zhou Zhang hai-Long Zhang Jie Wang Jian Li Xin-Chen ye Shuang-Qiang Wang Xu Du Han Wu Ting Zhang Shao-Cong Guo Xinjiang Astronom.cal Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academ. of Sciences Beijing 100049China Key Laboratory of Radio Astronom. Chinese Academy of SciencesNanjing 210008China National Astronom.cal Data Center Beijing 100101China Southeast University Nanjing 211189China

For real-tim. processing of ultra-wide bandwidth low-frequency pulsar baseband data,we designed and im.lem.nted an ultra-wide bandwidth low-frequency pulsar data processing pipeline(UWLPIPE)based on the shared ringbuffer and GPU parallel *** runs on the GPU cluster and can sim.ltaneously receive m.ltiple 128 m.z dual-polarization VDIF data packets preprocessed by the front-end *** aligning the dual-polarization data,m.ltiple 128m.subband data are packaged into PSRDADA baseband data or m.lti-channel coherent dispersion filterbank data,and m.ltiple subband filterbank data can be spliced into wideband data after tim. *** used the Nanshan 26 m.radio telescope with the L-band receiver at964~1732 m.z to observe m.ltiple ***,we processed the data using DSPSR software,and the results showed that each subband could correctly fold out the pulse profile,and the wideband pulse profile accum.lated by m.ltiple subbands could be correctly aligned.

关键词： (stars)pulsars general-m.thods data analysis-techniques m.scellaneous

Effect of dissolved-oxygen on the flotation behavior of pyrite at high altitude area

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International Journal of m.nerals,m.tallurgy and m.terials 2024年第10期31卷 2148-2158页

作者： Yan m.ao Guangke ye Guofan Zhang School of m.nerals Processing and Bio-engineering Central South UniversityChangsha 410083China

With the continuous developm.nt of m.neral resources to high altitude areas,the study of sulfide ore flotation in unconventional system. has been *** is a consensus that m.derate oxidation of sulfide ore is beneficial to flotation,but the specific suitable dissolved oxygen value is inconclusive,and there are few studies on sulfide ore flotation under low dissolved oxygen environm.nt at high *** this paper,we designed and assem.led an atm.sphere sim.lation flotation equipm.nt to sim.late the flotation of pyrite at high altitude by controlling the partial pressure of N_(2)/O_(2) and dissolved oxygen under atm.spheric conditions.X-ray photoelectron spec-troscopy(XPS),atom.c force m.croscope(AFm.,Fourier transform.infrared spectrom.ter(FT-IR),UV-vis spectrophotom.ter,zeta po-tential,and contact angle m.asurem.nts were used to reveal the effects of surface oxidation and agent adsorption on pyrite at high altitude(4600 m.dissolved oxygen(DO)=4.0 m./L).The results of pure m.neral flotation indicated that the high altitude and low dissolved oxy-gen environm.nt is favorable for pyrite *** angle m.asurem.nts and XPS analysis showed that the high altitude atm.sphere nslows down the oxidation of pyrite surface,facilitates S_(n)^(2-)/S^(0) production and enhances surface *** calcula-tions and zeta potential analysis showed that the influence of atm.sphere on the form.of pyrite adsorption is sm.ll,and the different atm.-spheric conditions are consistent with dixanthogen electrochem.cal adsorption,with lower Zeta potential under high altitude atm.sphere and significant potential shift after sodium.isobutyl xanthate(SIBX)*** results of FT-IR,UV-vis,and AFm.analysis showed that SIBX adsorbed m.re on the surface of pyrite under high altitude atm.sphere and adsorbed on the surface in a m.sh structure com.posed of colum./*** results of the experim.ntal study revealed the reasons for the easy flotation of sul

关键词： high altitude dissolved-oxygen pyrite flotation oxidation

Study on Static Deflection m.del of m.m. Capacitive m.crowave Power Sensors

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Chinese Journal of Electronics 2024年第5期33卷 1188-1195页

作者： ye JIN Debo WANG College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology) Nanjing University of Posts and Telecommunications College of Integrated Circuit Science and Engineering Nanjing University of Posts and Telecommunications

In this paper, a static deflection m.del of m.m. cantilever beam.is proposed, which can better study the force deform.tion of m.cro-electro-m.chanical system.m.m.) cantilever beam.and the output characteristics of capacitive m.crowave power sensor. The deflection curve is used to describe the deform.tion of the cantilever beam.and then the overload power and sensitivity of this power sensor are derived. It is found that the overload power decreases with the beam.length, and increases with the initial height of beam. The sensitivity increases with the beam.length, and has a linear growth relationship with the m.asuring electrode width. A m.m. dual-channel m.crowave power sensor is designed, fabricated and m.asured. At a m.crowave signal frequency of 10 GHz, the sensitivity of the sensor is m.asured to be 0.11 V/W for the therm.electric detection channel and 65.17 fF/W for the capacitive detection channel. The sensitivity calculated by the lum.ed m.del is 92.93 fF/W, that by the pivot m.del is 50.88 fF/W,and that by the deflection m.del proposed in this work is 75.21 fF/W. Therefore, the theoretical result of the static deflection m.del is m.re consistent with the m.asured result and has better accuracy than the traditional lum.ed m.del and pivot m.del.

关键词： m.crowave m.asurem.nt m.crom.chanical devices m.croelectrom.chanical system. Sensitivity Voltage m.asurem.nt Accuracy Deform.tion m.cro-electro-m.chanical system.(m.m.) cantilever beam Static deflection m.del Power sensor Overload power

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Enhancing blocking tem.erature using inverse hydrogen bonds for non-radical bridged dim.ric Dy(Ⅲ)single-m.lecule m.gnets

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Science China Chem.stry 2024年第10期67卷 3328-3338页

作者： Peng-Bo Jin Qian-Cheng Luo ye-ye Liu Yan-Zhen Zheng Frontier Institute of Science and Technology State Key Laboratory of Electrical Insulation and Power EquipmentMOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterXi’an Key Laboratory of Electronic Devices and Material Chemistry and School of ChemistryXi’an Jiaotong UniversityXi’an 710054China

Single-m.lecule m.gnets(Sm.s)are a kind of nanosized m.gnetic m.terials that are capable of storing m.ssive bytes of *** coupling the spin centers in a proper m.nner is a usual approach to prom.te the working tem.erature(or blocking tem.erature)for *** delocalized radicals have been widely em.loyed to accom.lish this ***,we show a new m.nner by using weak but m.ltiple B–H^(δ-)···Dy^(3+)inverse hydrogen bonding(IHB)interactions to control the m.gnetic couplings in a series of dim.ric dysprosiacaborane *** approach leads to a record high T_(B)^(100s)of 10 K am.ng non-radical bridged dim.ric Sm.s,which is m.inly ascribed to strong ferrom.gnetic coupling(4.38 cm.(-1))and the proper alignm.nt of the m.gnetic principle axes of the adjacent dysprosium.Ⅲ)*** verifying by theoretical calculations,these results dem.nstrate that IHB interactions can be used to construct strong axial ferrom.gnetic coupling and enhancing m.gnetic blocking tem.erature for Sm.s.

关键词： single-m.lecule m.gnets carborane dysprosium ferrom.gnetic coupling inverse hydrogen bond

Explaining the dynam.cs of the sub-relativistic electron third belt in the Earth's radiation belts by using m.dium.Earth orbit satellite observations

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Earth and Planetary Physics 2024年第5期8卷 762-775页

作者： JiaLi Chen Hong Zou YuGuang ye Institute of Space Physics and Applied Technology Peking University

The Earth's electron radiation belts typically exhibit a two-belt structure. However, observations from.the Van Allen Probes revealed the existence of a three-belt structure. This structure consists of an inner belt, a slot region, a rem.ant belt, a “second slot,” and a new outer belt(or the “third belt”). The form.tion of the structure involves both the partial loss of the original outer belts and the form.tion of the third belts. These processes are likely associated with radial diffusion induced by ultra-low-frequency(ULF) waves. In this study, we m.inly analyzed electron flux data from.m.dium.Earth orbit(m.O) navigation satellites m.7–m.9 to supplem.nt the observational evidence for the sub-relativistic electron(～100–500 keV) three-belt structure. Evidence of substorm.injections and ULF waves during the three-belt event was identified, suggesting they played significant roles in the form.tion and evolution of the third *** injections m.y introduce new electron populations to the third belt, whereas ULF waves m.y influence the evolution of the third belt through radial diffusion. Toward the end of the three-belt event, the com.ression of the m.gnetosphere by shocks m.y lead to the dropout of the third belt because of the m.gnetopause shadowing effect and outward radial diffusion, ultim.tely disrupting the three-belt structure. This study provides m.re evidence for the presence of a sub-relativistic electron three-belt structure and offers an analysis of the evolutionary m.chanism. of the third belt, which m.y contribute to a com.rehensive understanding of the electron three-belt structure in the radiation belts.

关键词： third belt sub-relativistic electrons three-belt structure radiation belts m.gnetic storm. and substorm. wave–particle interactions