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Transverse mode-coupling instability with longitudinal impedance

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Nuclear Science and Techniques 2024年第6期35卷 40-53页

作者： Hai-sheng Xu chun-Tao Lin Na Wang Jing-Ye Xu Yuan Zhang Key Laboratory of Particle Acceleration Physics and Technology Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China Institute of Advanced Science Facilities Shenzhen 518107GuangdongChina

Transverse mode-coupling instability(TMCI)is a dangerous transverse single-bunch instability that can lead to severe par-ticle *** mechanism of TMCI can be explained by the coupling of transverse coherent oscillation modes owing to the transverse short-range wakefield(i.e.,the transverse broadband impedance).Recent studies on future circular colliders,e.g.,FCC-ee,showed that the threshold of TMCI decreased significantly when both longitudinal and transverse impedances were *** performed computations for the circular electron-positron collider(CEPC)and observed a similar *** studies on the influence of longitudinal impedance on the TMCI threshold were *** concluded that the imaginary part of the longitudinal impedance,which caused a reduction in the incoherent synchrotron tune,was the primary reason for the reduction in the TMCI ***,the real part of the longitudinal impedance assists in increasing the TMCI threshold.

关键词： Transverse mode-coupling instability Longitudinal impedance

Hydrodynamic characteristics and particle tracking of 90° lateral intakes at an inclined river slope

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Water Science and Engineering 2024年第2期17卷 197-208页

作者： Wei He Si-yuan Feng Jian Zhang Hong-wu Tang Yang Xiao sheng Chen chun-sheng Liu College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China State Key Laboratory of Hydrology Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China Collaborative Innovation Center on Water Safety and Water Science Hohai UniversityNanjing 210098China

Lateral intakes are common in *** pump effciency and sediment deposition are determined by the local hydrodynamic characteristics and mainstream division *** hydraulic characteristics of lateral withdrawal from inclined river slopes at different intake elevations should be ***,the division width exhibits significant vertical non-uniformity at an inclined river slope,which should be ***,a three-dimensional(3-D)hydrodynamic and particle-tracking model was developed with the Open Source Field Operation and Manipulation(Open FOAM),and the model was validated with physical model tests for 90°lateral withdrawal from an inclined side *** flow fields,withdrawal sources,and division widths were investigated with different intake bottom elevations,withdrawal discharges,and main channel *** study showed that under inclined side bank conditions,water entered the intake at an oblique angle,causing significant 3-D spiral flows in the intake rather than two-dimensional closed recirculation.A lower withdrawal discharge,a lower bottom elevation of the intake,or a higher main channel velocity could further strengthen this *** average division width and turbulent kinetic energy were smaller under inclined side bank conditions than under vertical bank *** a low intake bottom elevation,a low withdrawal discharge,or a high main channel velocity,the sources of lateral withdrawal were in similar ranges near the local inclined bank in the vertical *** inclined slope conditions,sediment deposition near the intake entrance could be reduced,compared to that under vertical slope *** results provide hydrodynamic and sediment references for engineering designs for natural rivers with inclined terrains.

关键词： Lateral withdrawal Hydrodynamic characteristics Particle tracking Inclined river slope Bottom elevation of intake OpenFOAM

Molecular mechanism for the unusual enhancement of the second-step chemiluminescence production from the carcinogenic tetrabromohydroquinone and H2O_(2)

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Journal of Environmental Sciences 2024年第7期141卷 330-342页

作者： Zi-Han Wang chun-Hua Huang Zhi-sheng Liu Li Mao Ben-Zhan Zhu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Environment and Resources University of Chinese Academy of SciencesBeijing 100049China

We have found recently that two-step intrinsic hydroxyl radical(·OH)-dependent chemiluminescence(CL)could be produced by carcinogenic tetrahaloquinone and H_(2)O_(2).However,the first-step CL was too fast to clearly detect the stepwise generation of·OH and CL,and to distinguish the exact dividing point between the first-step and second-step *** we found that,extremely clear two-step intrinsic CL could be produced by the relative slow reaction of tetrabromohydroquinone(TBHQ)with H_(2)O_(2),which was directly dependent on the two-step·OH ***,the second-step,but not the first-step CL production of TBHQ/H_(2)O_(2)(CRET donor)was markedly enhanced by fluorescein(a typical xanthene dye,CRET acceptor)through a unique chemiluminescence resonance energy transfer(CRET)*** novel CRET system of TBHQ/H_(2)O_(2)/fluorescein was successfully applied for the sensitive detection of TBHQ with the detection limit as low as 2.5μmol/*** findings will help to develop more sensitive and highly efficient CL or CRET systems and specific CL sensor to detect the carcinogenic haloquinones,which may have broad environmental applications.

关键词： Two-step chemiluminescence Bromohydroquinone Hydrogen peroxide Hydroxyl radical CRET

The influence of yttrium and manganese additions on the degradation and biocompatibility of magnesium-zinc-based alloys:In vitro and in vivo studies

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Journal of Magnesium and Alloys 2024年第2期12卷 608-624页

作者： Lei Shi Yang Yan chun-sheng Shao Kun Yu Bo Zhang Liang-jian Chen Third Xiangya Hospital Central South UniversityChangsha 410013China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China School of Materials Science and Engineering Central South UniversityChangsha 410083China Department of Mechanical Engineering City University of Hong KongHong KongChina

The repair and regeneration of bone defects are highly challenging orthopedic ***,Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human *** aim of our study is to develop a magnesium alloy with a controllable degradation that can closely match bone tissue to help injuries heal in vivo and avoid cytotoxicity caused by a sudden increase in ion *** this study,we prepared and modified Mg-3Zn,Mg-3Zn-1Y,and Mg-2Zn-1Mn by hot extrusion,and used Mg-2.5Y-2.5Nd was as a *** then investigated the effect of additions of Y and Mn on alloys'*** results show that Mn and Y can improve not only compression strength but also corrosion *** alloy Mg-2Zn-1Mn demonstrated good cytocompatibility in vitro,and for this reason we selected it for implantation in *** degraded Mg-2Zn-1Mn implanted a bone defect area did not cause obvious rejection and inflammatory reaction,and the degradation products left no signs of damage to the heart,liver,kidney,or ***,we find that Mg-2Zn-1Mn can promote an osteoinductive response in vivo and the formation of bone regeneration.

关键词： Magnesium alloy Biodegradation Biocompatibility Bone regeneration Bone defect repair

Numerical Study on the Effect of Gap Diffraction on the Hydrodynamic Performance of A Floating Breakwater

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China Ocean Engineering 2024年第4期38卷 663-675页

作者： BIAN Xiang-qian JI chun-yan XU sheng GUO Jian-ting HUO Fa-li School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

Two-dimensional(2D)flume experiments are useful in investigating the performances of floating breakwaters(FBs),including hydrodynamic performances,motion responses,and mooring *** a reasonable gap between the flume wall and the FBs is a critical step in 2D flume ***,research on the effect of the gap on the accuracy of 2D FB experimental results is *** address this issue,a numerical wave tank is developed using CFD to estimate the wave-FB interaction of a moored dual-cylindrical FB,and the results are compared to experimental data from a previously published *** is good agreement between them,indicating that the numerical model is sufficiently *** numerical model is then applied to explore the effect of gap diffraction on the performance of FBs in2D *** was discovered that the nondimensional gap length L_(Gap)/W_(Pool)should be smaller than 7.5%to ensure that the relative error of the transmission coefficient is smaller than 3%.The influence of the gap is also related to the entering wave properties,such as the wave height and period.

关键词： floating breakwater diffraction effect gap hydrodynamic performance model experiments CFD numerical simulation

Radical involved reactive wetting and retarding mechanism of alumina refractory ceramic by molten slags under weak static magnetic field

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Journal of Iron and Steel Research(International) 2024年第6期31卷 1355-1366页

作者： sheng-hao Li Ao Huang Fan-bo Zeng Hui Peng Hao-ran Wei Xue-chun Huang sheng-qiang Song Hua-zhi Gu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

High alumina slag will cause severe corrosion at the interface of alumina refractory,and the wetting behavior of slag is a key factor influencing the corrosion resistance of refractory *** static magnetic field is a promising solution for improvement in the slag resistance of *** wetting of alumina refractory ceramics with different basicities of high alumina slags under a weak static magnetic field was analyzed,given that a weak static magnetic field can affect the corrosion behavior of refractory *** slag S_(3) as an example,when there was an external static magnetic field of 1.0 mT at 1600 ℃,the thickness of calcium aluminate reaction layer at the interface decreased by 36.7%,the denting depth of interface decreased by 35.6%,and the apparent wetting angle increased by 20%.The living radicals and their formation path in oxide melts were verified by first-principles calculation combined with electron paramagnetic resonance spectroscopy *** influence of the flux density of a weak static magnetic field on the wetting behavior of slags was also *** contact angle of the slags increased owing to the inhibitory effect of magnetic field on the radicalinvolved reaction at the interface of the slag and the alumina refractory *** relationships between the magnetic flux density,diffusion coefficient,slag microstructure(hyperfine coupling constant),and contact angle were *** provides a theoretical basis for the field control of radical involved reactive wetting between inorganic oxide slags and solid oxide ceramics.

关键词： Alumina refractory ceramic Molten slag Weak magnetic field effect Reactive wetting Free radical

Ovular development and perisperm formation in Phytolacca americana (Phytolaccaceae) and their systematic significance in Caryophyllales

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Journal of Systematics and Evolution 2010年第5期48卷 318-325页

作者： Hong-chun zheng sheng-Wen MA Tuan-Yao CHAI(College of Life Science,Graduate University of Chinese Academy of Sciences,Beijing 100049,China) (College of Life Science Graduate University of Chinese Academy of Sciences Beijing 100049 China)

Phytolacca is the biggest and most original genus in Phytolaccaceae and an important genus in plant systematic *** microscopy results show that the Phytolacca americana *** arises from the caulis(floral receptacle).The perisperm and hypostase are simultaneously initiated from the top several layers of cells of chalaza after fertilization,and the perisperm is located between the nucellus and *** the early stages of development,the hypostase cells are thin-walled with dense cytoplasm,clear nuclei,and some reserve ***,at the heart-shaped embryo stage,the hypostase cells are dead and *** main functions of the hypostase may be to maintain cellular division and perisperm growth without delivering nutrient materials to the *** evolutionary picture of placentation in Caryophyllales is also presented.

关键词： hypostase nucellus ovule perisperm Phytolacca placentation.

Formation of mesophase microbeads from bulk mesophase pitch induced by fullerene

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新型炭材料（中英文） 2024年第4期39卷 645-654页

作者： CHEN Wen-sheng LIU Lan-tao WANG zheng DUAN chun-feng ZHANG Xing-wei MA Zhao-kun CHEN Xiao-hong SONG Huai-he State Key Laboratory of Chemical Resource Engineering Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing Uni-versity of Chemical TechnologyBeijing 100029China

A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liquid-phase carbonization of isotropic pitch to the emergence of carbon microbeads in the matrix and finally their growth to form a 100%anisotropic bulk meso-phase,but rather a reverse *** effects of C_(60) loading and reaction temperature on the morphological transformation of mesophase were investigated by polarizing optical and scanning electron *** physical changes in the NMP induced by C_(60) were characterized by thermogravimetric analysis,Fourier transform infrared spectroscopy,X-ray diffractometry and Raman *** results show that the coalesced NMP can be converted to a spherical type at 300-320℃ with the addition of 5%C_(60),and the size of the mesophase microbeads increases with increasing ***,a model is established to ex-plain the unique induction effect of C_(60) in the transformation *** work makes the morphological transformation of MP con-trollable,and provides a new idea for the understanding and research of mesophase pitch.

关键词： Reversible transformation Fullerene induction mechanism Mesophase texture π-electron-induced effect Mesophase microbeads

Energy saving analysis for CO_(2)–O_(2)mixed injection technology in converter steelmaking

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Journal of Iron and Steel Research(International) 2024年第5期31卷 1095-1103页

作者： Bao-chen Han chun-liang Gao Ya-qiang Li Dan Liu Guang-sheng Wei Rong Zhu Hebei Key Laboratory of Material Near-Net Forming Technology School of Material Science and EngineeringHebei University of Science and TechnologyShijiazhuang050018HebeiChina Department of Automotive Engineering Hebei Vocational University of Technology and EngineeringXingtai054000HebeiChina School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China

Energy-saving in China's iron and steel industry still relies on the development and improvement of short-term energy saving ***,a special converter smelting technology incorporating energy saving was *** evaluate the energy-saving potential of the CO_(2)–O_(2)mixed injection(COMI)technology,collected production data were used to develop an improved techno-economic *** reveal that the technology can save energy through auxiliary material consumption,sensible heat of solid by-product,iron loss reduction,and energy *** application of COMI technology in an enterprise is cost effective,involving the energy saving potential of 0.206 GJ/t,the cost of conserved energy of−48.83 yuan/GJ,and a simple payback period of 0.35 year for a 60-million-yuan *** analysis shows that the investment cost and discount rate primarily influence the cost of conserved energy of the *** the discount rate increased,the cost of conserved energy also gradually ***,the COMI technology is an energy-saving technology with good development prospects.

关键词： Converter steelmaking COMI technology Energy saving Techno-economic model Investment cost