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Controlling secondary flow in high-lift low-pressure turbine using boundary-layer slot suction

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Chinese Journal of Aeronautics 2024年第3期37卷 21-33页

作者： Xiao qu Liunan LI Yingjie zhang Xingen lu Junqiang ZHU Yanfeng zhang School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Light-Duty Gas-Turbine Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing 100190China

The design of high-lift Low-Pressure Turbines(LPTs)causes the separation of the boundary layer on the suction side of the blade and leads to a strong secondary flow.This present study aims to minimize secondary losses through endwall slot suction and incoming wakes in a front-loaded high-lift LPT cascade with Zweifel of 1.58 under low Reynolds number of 25000.Two slotted schemes for the boundary layer of the endwall were designed(Plan A and Plan B),and the effects of suction mass flow on secondary flow were studied.The underlying physics of the endwall boundary layer of the suction and secondary flow under unsteady wakes was discussed.The results show that slot suction at the endwall boundary layer can significantly suppress the secondary flow by removing low-momentum fluids.Plans A and B significantly reduced the secondary kinetic energy by 44.2%and 36.9%,respectively,compared with the baseline cascade at the suction mass flow ratios of 1%.With an increase in the mass flow ratio of suction,the secondary flow was gradually reduced in both Plans A and B.It is more beneficial to control the secondary flow to destroy the intersection of the pressure side and suction side of the horseshoe vortex before it develops into a passage vortex.Under unsteady wakes,the combined effects of incoming wakes and endwall boundary layer suction can further suppress the secondary flow at the suction mass flow ratios of 2%for Plan A,because the positive and negative vorticity inside upstream wakes accelerated the mixing of the main flow and secondary flow and thus increased the energy of secondary vortices.

关键词： Low-pressure turbine Secondary flow Flow control Boundary-layer suction Incoming wake

A genetic variant study of bortezomib-induced peripheral neuropathy in Chinese multiple myeloma patients

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Oncology Research 2024年第5期32卷 955-963页

作者： YAN zhang HEYANG zhang JING WANG XIN wei YI qu FENG XU LIJUN zhang Department of Hematology The First Affiliated Hospital of China Medical UniversityShenyang110001China

Background:Bortezomib results in peripheral neuropathy(PN)in approximately 50%of patients,during multiple myeloma(MM)treatment,a complication known as Bortezomib-induced peripheral neuropathy(BIPN).The drug response varies among individuals.Genetic factor may play an important role in BIPN.Methods:A nextgeneration sequencing(NGS)panel containing 1659 targets from 233 genes was used to identify risk variants for developing BIPN in 204 MM patients who received bortezomib therapy.mRNA expression of MTHFR and ALDH1A1 in 62 peripheral blood samples was detected by real-time quantitative PCR(RT-qPCR).Serum homocysteine(Hcy)levels were detected in 40 samples by chemiluminescent microparticle immunoassay(CMIA).Results:Compared with the non-BIPN group(n=89),a total of 8 significantly associated single nucleotide polymorphisms(SNPs)were identified in the BIPN group(n=115):MTHFR(rs1801131,rs1801133,rs17421511),EPHX1(rs1051740),MME(rs2016848),ALDH1A1(rs6151031),HTR7(rs1935349)and CYP2A6(rs8192720).The mRNA expression level of MTHFR in newly diagnosed patients with peripheral neuritis after treatment(NP group)was lower than that of newly diagnosed patients without peripheral neuritis after treatment(NnP group)(1.70±0.77 vs.2.81±0.97,p=0.009).Serum Hcy levels were significantly higher in BIPN group than in non-BIPN group(11.66±1.79μmol/L vs.8.52±3.29μmol/L,p=0.016)and healthy controls(11.66±1.79μmol/L vs.8.55±2.13μmol/L,p≤0.001).Conclusion:CYP2A6,EPHX1,MTHFR,ALDH1A1,HTR7,MME and BIPN are linked in Chinese MM patients.BIPN is more likely to occur in patients with lower MTHFR mRNA expression,which might result in higher serum Hcy levels.

关键词： Multiple Myeloma Peripheral neuropathy Bortezomib Bortezomib-induced peripheral neuropathy Next-generation sequencing MTHFR Serum Hcy

Modulated-ISRJ rejection using online dictionary learning for synthetic aperture radar imagery

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Journal of Systems Engineering and Electronics 2024年第2期35卷 316-329页

作者： wei Shaopeng zhang Lei lu Jingyue LIU Hongwei College of Oceanography and Space Informatics China University of Petroleum(East China)Qingdao 266580China School of Electronics Engineering Xidian UniversityXi’an 710071China School of Electronics and Communication Engineering Shenzhen Campus of Sun Yat-sen UniversityGuangzhou 518107China School of Computer Science and Technology Xidian UniversityXi’an 710071China

In electromagnetic countermeasures circumstances,synthetic aperture radar(SAR)imagery usually suffers from severe quality degradation from modulated interrupt sampling repeater jamming(MISRJ),which usually owes considerable coherence with the SAR transmission waveform together with periodical modulation patterns.This paper develops an MISRJ suppression algorithm for SAR imagery with online dictionary learning.In the algorithm,the jamming modulation temporal properties are exploited with extracting and sorting MISRJ slices using fast-time autocorrelation.Online dictionary learning is followed to separate real signals from jamming slices.Under the learned representation,time-varying MISRJs are suppressed effectively.Both simulated and real-measured SAR data are also used to confirm advantages in suppressing time-varying MISRJs over traditional methods.

关键词： synthetic aperture radar(SAR) modulated interrupt sampling jamming(MISRJ) online dictionary learning

Optimal Planning of Hybrid AC/DC Low-voltage Distribution Networks Considering DC Conversion of Three-phase Four-wire Low-voltage AC Systems

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 141-153页

作者： Bo zhang lu zhang wei Tang Gen Li Chen Wang the College of Information and Electrical Engineering China Agricultural UniversityBeijing 100083China the Electric Energy Group Department of Engineering TechnologyTechnical University of Denmark(DTU)2750 BallerupDenmark the Power Distribution Technology Center State Grid Beijing Electric Power Research InstituteBeijing 100075China

The increasing integration of distributed household photovoltaics(PVs)and electric vehicles(EVs)may further ag gravate voltage violations and unbalance of low-voltage distribu tion networks(LVDNs).DC distribution networks can increase the accommodation of PVs and EVs and mitigate mutilple pow er quality problems by the flexible power regulation capability of voltage source converters.This paper proposes schemes to es tablish hybrid AC/DC LVDNs considering the conversion of the existing three-phase four-wire low-voltage AC systems to DC op eration.The characteristics and DC conversion constraints of typical LVDNs are analyzed.In addition,converter configura tions for typical LVDNs are proposed based on the three-phase four-wire characteristics and quantitative analysis of various DC configurations.Moreover,an optimal planning method of hybrid AC/DC LVDNs is proposed,which is modeled as a bi-level programming model considering the annual investments and three-phase unbalance.Simulations are conducted to verify the effectiveness of the proposed optimal planning method.Sim ulation results show that the proposed optimal planning method can increase the integration of PVs while simultaneously reduc ing issues related to voltage violation and unbalance.

关键词： Optimal planning low-voltage distribution net work three-phase unbalance DC conversion

Characteristics and geological significance of the stress state of the lithosphere in the Qinghai-Tibetan Plateau and its neighboring areas

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Science China Earth Sciences 2024年第6期67卷 1836-1855页

作者： Qianwen zhang Ya XU wei CHU Shupeng lu Key Lab of Petroleum Resource Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The present-day lithospheric stress state of the Qinghai-Tibetan Plateau and neighboring areas is controlled by both the lithosphere itself and the underlying mantle.In other words,the stress is affected by the gravitational potential energy(GPE)difference caused by the change in the density distribution within the lithosphere and the drag force on the base of the lithosphere caused by mantle convection.The study of the lithospheric stress state plays an important role in further understanding the dynamic background and mechanism for the evolution of the Qinghai-Tibetan Plateau.In this study,the Crust1.0 crustal density model combined with the S40RTS mantle shear wave velocity variation model was used to calculate the GPE.The EGM2008gravity field model was used to calculate the drag force from mantle convection at the base of the lithosphere.The lithospheric and joint stress fields of the two sources were obtained by solving the force balance under the thin sheet approximation.This way,we could comprehensively analyze the characteristics of the stress state within the Plateau.Six regions were classified according to the GPE stress field,mantle drag force stress field,the relative magnitude of the two stress fields,and correlation between the two stress fields and surface deformation.The lithospheric stress fields of the Tarim Basin and other stable blocks are mainly controlled by the GPE difference.The lithospheric stress field in the collision zone between the Indian Plate and the QinghaiTibetan Plateau is predominantly controlled by the deep mantle drag force.The lithospheric stress field in the interior of the Plateau is controlled by both GPE and mantle drag.The correlation between the lithospheric stress field and surface deformation at the southeast margin of the Qinghai-Tibetan Plateau is poor.It is hypothesized that the presence of lower crustal flow with lower effective viscosity leads to crust-mantle decoupling,and the mantle drag force has a weaker influence on the shallow crust,resulting in the incons

关键词： Qinghai-Tibetan Plateau Gravitational potential energy Mantle convection Lithospheric deviatoric stress field GPS strain rate field

An in-situ polymerized interphase engineering for high-voltage allsolid- state lithium-metal batteries

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Nano Research 2024年第4期17卷 2687-2692页

作者： lu Nie Shaojie Chen Mengtian zhang Tianyi Gao Yuyao zhang Ran wei Yining zhang wei Liu School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Tsinghua-Berkeley Shenzhen Institute&Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055China

All-solid-state lithium batteries(ASSLBs)have attracted great interest due to their promising energy density and strong safety.However,the interface issues,including large interfacial resistance between electrode and electrolyte and low electrochemical stability of solid-state electrolytes against high-voltage cathodes,have restricted the development of high-voltage ASSLBs.Herein,we report an ASSLB with stable cycling by adopting a conformal polymer interlayer in-situ formed at the Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)–cathode interfaces.The polymer can perfectlyﬁll the voids and create a stable interface contact between LLZTO and cathodes.In addition,the electric field across the polymer interlayer is reduced compared with pure solid polymer electrolyte(SPE),which facilitates the electrochemical stability with high-voltage cathode.The all-solid-state Li|LLZTO-SPE|LiFe_(0.4)Mn_(0.6)PO_(4)(LMFP)cells achieve a low interface impedance,high specific capacity,and excellent cycling performance.This work presents an effective and practical strategy to rationally design the electrode–electrolyte interface for the application of high-voltage ASSLBs.

关键词： all-solid-state lithium batteries interface contact electric field electrochemical stability

Numerical simulation of transient characteristics in a bulb turbine during the load rejection process

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Journal of Hydrodynamics 2024年第1期36卷 170-183页

作者： Yue lu Yu-quan zhang Zhong-wei He Yuan Zheng College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China College of Energy and Electrical Engineering Hohai UniversityNanjing210098China Huadong Engineering Corporation Ltd. Hangzhou311122China

To evaluate the safety of the bulb tubular turbine,the dynamic hydraulic characteristics of a hydropower station system during the load rejection process are studied through numerical simulations and a prototype test.In the developed model,a dynamic grid technology(DGT)controls the closure of the guide vane and the blade,whilst the moment balance equation and the user-defined function(UDF)provide the runner’s rotation speed.The 3-D transient simulation method can well predict the rotation speed and mass flow curves in the state of load rejection.The simulation outcomes of the system performance are basically consistent with the measurement data of the prototype.As observed,the runner is subjected to the reversely increased torque and axial force,the system is in a braking phase,and the maximum speed peaks at 144.6%of the rated speed.Moreover,the internal flow of the runner is greatly affected by the closure of the guide vane,and the draft tube forms an eccentric spiral vortex rope.It breaks downstream,aggravating the instability of the draft tube.Overall,the transient characteristics span for the first five seconds,demonstrating the importance of establishing an efficient governing controller.The obtained results are useful for designing the turbine’s flow channel with a double regulating function and comprehending the turbine’s transient characteristics.

关键词： Bulb tubular turbine load rejection numerical simulation dynamic grid prototype test

Phosphine-catalyzed acyl-transfer of heteroaryl ketones for the construction of N-fused heterocycles

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Chinese Chemical Letters 2024年第3期35卷 252-256页

作者： Yu zhang De-Rui Han Dan Ye Hong lu Hao wei Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemistry&Materials ScienceNorthwest UniversityXi'an 710069China

An inexpensive phosphine catalyst was used effectively for a transition-metal-free acyl-transfer of N-containing heteroaryl ketones for the rapid synthesis of N-fused heterocycles.The key pre-aromatic spirocyclic intermediate initialized by the single electron transfer(SET)process of Togni's reagentⅡpromoted by the tertiary phosphine resulted in an intriguing and alternative tactic for the cleavage of C–C bonds.By using inexpensive tertiary phosphine as the catalyst,this skeleton-reorganizing approach of N-containing heteroaryl ketones allows a streamlined assembly of complex N-fused heterocycles with broad functional group tolerance.

关键词： Phosphine catalysis Acyl-transfer N-Fused heterocycles C–C bond activation Aromatization

Spatial-temporal shifting patterns and in situ conservation of spotted seal(Phoca largha)populations in the Yellow Sea ecoregion

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Integrative Zoology 2024年第2期19卷 307-318页

作者： Hongfei ZHUANG Fei SHAO Chao zhang Wancai XIA Shouqiang WANG Fangyuan qu Zongling WANG Zhichuang lu Linlin ZHAO Zhaohui zhang First Institute of Oceanography Ministry of Natural ResourcesQingdaoChina Department of Natural Resources of Shandong Province Shandong Forestry Protection and Development Service CenterJinanChina National Park(Protected Areas)Development Center National Forestry and Grassland AdministrationBeijingChina College of Life Science China West Normal UniversityNanchongChina Liaoning Ocean and Fisheries Science Research Institute DalianChina

Understanding the habitat shifting pattern is a prerequisite for implementing in situ conservation of migratory species.Spotted seals(Phoca largha)inhabiting the Yellow Sea ecoregion(YSE)comprise a small population with independent genes and represent a charismatic flagship species in this region.However,this population has declined by 80%since the 1940s,and increased support from the countries around the YSE is urgently needed to address the potential local extinction risk.A time-series niche model and life-history weighted systematic conservation planning were designed on the basis of a satellite beacon tracking survey(2010–2020)of the YSE population.The results showed clustering and spreading shifting patterns during the breeding and migratory seasons,respectively.The closed-loop migration route formed in the YSE indicated that this population might be geographically isolated from populations in other breeding areas around the world.The conservation priority area(CPA),with an area of 19632 km^(2)(3.58%of the total YSE area),was the most effective response to the potential in situ risk.However,nearly 80%of the CPA was exposed outside the existing marine protected areas(MPAs).Future establishment of MPAs in China should strategically consider the conservation gap identified herein,and it is recommended for Korea’s closed fishing season to be spatially set in the western Korean Peninsula from May to August.This study also exemplified that the lack of temporal information would lead to the dislocation of niche modeling for migratory species represented by spotted seals.Attention should be paid to protecting small and migratory populations in marine biodiversity conservation planning.

关键词： conservation priority area marine protected area migration seasonal management spotted seal