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Hawking-Page phase transitions of charged AdS black holes surrounded by quintessence 认领
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作者 闫大伟 黄泽榕 李楠 《中国物理C:英文版》 SCIE CAS 2021年第1期355-365,共11页
Hawking-Page phase transitions between the thermal anti-de Sitter vacuum and charged black holes sur・rounded by quintessence are studied in the extended phase space.The quintessence field,with the state parameter-1<... Hawking-Page phase transitions between the thermal anti-de Sitter vacuum and charged black holes sur・rounded by quintessence are studied in the extended phase space.The quintessence field,with the state parameter-1<w<-1/3,modifies the temperature and the Gibbs free energy of a black hole.The phase transition temperature Thp and the Gibbs free energy G are first analytically investigated for the special case of w=-2/3,and then,the results of numerical simulations are shown for general w.The phase transition temperature Thp increases with pressure and decreases with electric potential.In addition,Thp significantly decreases owing to the quintessence field,which generates negative pressure around the black hole. 展开更多
关键词 Hawking-Page phase transition QUINTESSENCE extended phase space
Identification of potential oxidative stress biomarkers for spinal cord injury in erythrocytes using mass spectrometry 认领
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作者 Li-Jian Zhang Yao Chen +2 位作者 Lu-Xuan Wang Xiao-Qing Zhuang He-Chun Xia 《中国神经再生研究:英文版》 SCIE CAS 2021年第7期1294-1301,共8页
Oxidative stress is a hallmark of secondary injury associated with spinal cord injury.Identifying stable and specific oxidative biomarkers is of important significance for studying spinal cord injury-associated second... Oxidative stress is a hallmark of secondary injury associated with spinal cord injury.Identifying stable and specific oxidative biomarkers is of important significance for studying spinal cord injury-associated secondary injury.Mature erythrocytes do not contain nuclei and mitochondria and cannot be transcribed and translated.Therefore, mature erythrocytes are highly sensitive to oxidative stress and may become a valuable biomarker.In the present study, we revealed the proteome dynamics of protein expression in erythrocytes of beagle dogs in the acute and subacute phases of spinal cord injury using mass spectrometry-based approaches.We found 26 proteins that were differentially expressed in the acute(0–3 days) and subacute(7–21 days) phases of spinal cord injury.Bioinformatics analysis revealed that these differentially expressed proteins were involved in glutathione metabolism, lipid metabolism, and pentose phosphate and other oxidative stress pathways.Western blot assays validated the differential expression of glutathione synthetase, transaldolase, and myeloperoxidase.This result was consistent with mass spectrometry results, suggesting that erythrocytes can be used as a novel sample source of biological markers of oxidative stress in spinal cord injury.Glutathione synthetase, transaldolase, and myeloperoxidase sourced from erythrocytes are potential biomarkers of oxidative stress after spinal cord injury.This study was approved by the Experimental Animal Centre of Ningxia Medical University, China(approval No.2017-073) on February 13, 2017. 展开更多
关键词 acute phase bioinformatic analysis biomarkers central nervous system DOG erythrocytes mass spectrometry oxidative stress peripheral blood spinal cord injury subacute phase
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文章速递Preparation and Insecticidal Activity of Sea Anemone Peptide AP-GI from Aiptasia pallida 认领
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作者 Jinxing FU Yanling LIAO +1 位作者 Xuefeidan LIU Bingmiao GAO 《农业生物技术:英文版》 CAS 2021年第1期49-52,共4页
[Objectives] This study was conducted to synthesize sea anemone peptide Ap-GI and investigate its insecticidal activity. [Methods] The linear peptide Ap-GI was synthesized by solid phase peptide synthesis(SPPS), and t... [Objectives] This study was conducted to synthesize sea anemone peptide Ap-GI and investigate its insecticidal activity. [Methods] The linear peptide Ap-GI was synthesized by solid phase peptide synthesis(SPPS), and the linear peptide was subjected to the two-step oxidative folding, mass spectrometry identification and high performance liquid chromatography(HPLC) purification. Then, the MTT method and insect injection method were used to study its insecticidal activity. [Results] The synthesized sea anemone peptide had a purity of 95%. The test results of the MTT method showed that the peptide Ap-GI had the activity of inhibiting the growth of insect cells sf9 with the median effective dose of 0.7 nM;and the test results of the injection method on yellow mealworms showed that the peptide Ap-GI had high insecticidal activity, and the median lethal dose was 16.9 nM. [Conclusions] The sea anemone peptide Ap-GI from Aiptasia pallida has a good inhibitory effect on the growth of insect cells and high-efficiency insecticidal activity, which can lay a foundation for the development of new, safe and efficient peptide biological insecticides. 展开更多
关键词 Aiptasia pallida Sea anemone peptide Solid phase peptide synthesis Oxidative folding Insecticidal activity
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文章速递双偏心套式圆盘剪偏心套加工定位新工艺 认领
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作者 冀俊杰 张镭 +2 位作者 贾海亮 冯沙 吕阳阳 《重型机械》 2021年第1期42-46,共5页
广泛应用于板带材剪切生产线的双偏心套式圆盘剪具有上、下两个对称的偏心套,由于上、下偏心套通常采用划线定位法进行加工装配,导致其偏心量不一致,相位安装不对称。本文分析了偏心套相位不准确引起的重叠量精度误差及传统加工、装配工... 广泛应用于板带材剪切生产线的双偏心套式圆盘剪具有上、下两个对称的偏心套,由于上、下偏心套通常采用划线定位法进行加工装配,导致其偏心量不一致,相位安装不对称。本文分析了偏心套相位不准确引起的重叠量精度误差及传统加工、装配工艺,开发了一种新的偏心套定位工艺,新工艺采用坐标镗床加工机架内孔,通过定位定向销孔保证机架上、下偏心套偏心量与相位完全一致,重叠量精度可达到±0.03 mm,解决了传统圆盘剪偏心套相位定位引起的重叠量精度误差问题。 展开更多
关键词 圆盘剪 偏心套 加工工艺 相位
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文章速递Hybrid Method to Identify Second-trip Echoes Using Phase Modulation and Polarimetric Technology 认领
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作者 Shuai ZHANG Jinzhong MIN +3 位作者 Chian ZHANG Xingyou HUANG Jun LIU Kaihua WEI 《大气科学进展:英文版》 SCIE CAS CSCD 2021年第3期480-492,共13页
For pulse Doppler radars,the widely used method for identifying second-trip echoes(STs)in the signal processing level yields significant misidentification in regions of high turbulence and severe wind shear.In the dat... For pulse Doppler radars,the widely used method for identifying second-trip echoes(STs)in the signal processing level yields significant misidentification in regions of high turbulence and severe wind shear.In the data processing level,although the novel algorithm for ST identification does not yield significant misidentification in specific regions,its overall identification performance is not ideal.Therefore,this paper proposes a hybrid method for the identification of STs using phase modulation(signal processing)and polarimetric technology(data processing).Through this approach,most of the STs are removed,whereas most of the first-trip echoes(FTs)remain untouched.Compared with the existing method using a signal quality index filter with an optimized threshold,the hybrid method exhibits superior performance(Heidke skill scores of 0.98 versus 0.88)on independent test datasets,especially in high-turbulence and severe-wind-shear regions,for which misidentification is significantly reduced. 展开更多
关键词 second-trip echo phase modulation polarimetric radar wind shear
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文章速递Effective improvement of beam lifetime based on radiofrequency phase modulation at the HLS-II storage ring 认领
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作者 Yun-Kun Zhao Bao-Gen Sun +4 位作者 Ji-Gang Wang Fang-Fang Wu Ping Lu Tian-Yu Zhou San-Shuang Jin 《核技术:英文版》 SCIE EI CAS CSCD 2021年第1期1-9,共9页
A radiofrequency(RF)phase modulation method is applied to the Hefei Light Source II storage ring to deeply investigate its longitudinal beam characteristics and improve the beam lifetime.A theoretical analytical model... A radiofrequency(RF)phase modulation method is applied to the Hefei Light Source II storage ring to deeply investigate its longitudinal beam characteristics and improve the beam lifetime.A theoretical analytical model and corresponding experimental measurements of single bunch length and island phenomena are examined.From a series of online machine experiments,we demonstrate that the suitable phase modulation amplitude is 0.02 rad,corresponding to an optimum modulation frequency ranging from 19.6 to 20.7 kHz of the RF system.Furthermore,the overall beam lifetime can be increased by a factor of 2.38 as a result of the beam dilution effect. 展开更多
关键词 Phase modulation Amplitude Beam lifetime Longitudinal beam characteristics Beam dilution Island
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Case study on stratospheric and mesospheric concentric gravity waves generated by deep convection 认领
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作者 GuoChun Shi Xiong Hu +3 位作者 ZhiGang Yao WenJie Guo MingChen Sun XiaoYan Gong 《地球与行星物理:英文版》 2021年第1期79-89,共11页
Concentric gravity waves(CGWs)in the middle and upper atmosphere show wave-coupling processes between the lower atmosphere and the middle and upper atmosphere.In this research,we analyzed a case of CGWs detected simul... Concentric gravity waves(CGWs)in the middle and upper atmosphere show wave-coupling processes between the lower atmosphere and the middle and upper atmosphere.In this research,we analyzed a case of CGWs detected simultaneously by the AIRS(Atmospheric Infrared Sounder)and the VIIRS/DNB(Day/Night Band of the Visible Infrared Imager Radiometer Suite)in the stratosphere and mesosphere.Results showed that gravity waves(GWs)were generated by the collocated Hurricane Bejisa on the island of Mauritius.The AIRS data showed arc-like phase fronts of GWs with horizontal wavelengths of 190 and 150 km at 21:08 coordinated universal time(UTC)on 1 January 2014 and at 10:00 UTC on 2 January 2014,whereas the DNB observed arced GWs with horizontal wavelengths of 60 and 150 km in the same geographic regions at 22:24 UTC.The characteristics of CGW parameters in the stratosphere(~40 km)and the mesosphere(~87 km),such as the vertical wavelength,intrinsic frequency,and intrinsic horizontal phase speed,were first derived together with the background winds from ERA5 reanalysis data and Horizontal Wind Model data through the dispersion relationship of GWs and the wind-filtering theory. 展开更多
关键词 concentric gravity waves WAVELENGTH intrinsic frequency phase speed
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Molecular dispersion enhances photovoltaic efficiency and thermal stability in quasi-bilayer organic solar cells 认领
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作者 Xuning Zhang Yanxun Li +9 位作者 Dongyang Zhang Guangbao Wu Hong Zhang Jiyu Zhou Xing Li Saud-uz-Zafar Jianqi Zhang Zhixiang Wei Huiqiong Zhou Yuan Zhang 《中国科学:化学英文版》 SCIE EI CAS 2021年第1期116-126,共11页
In comparison to widely adopted bulk heterojunction(BHJ)structures for organic solar cells(OSC),exploiting the sequential deposition to form planar heterojunction(PHJ)structures enables to realize the favorable vertic... In comparison to widely adopted bulk heterojunction(BHJ)structures for organic solar cells(OSC),exploiting the sequential deposition to form planar heterojunction(PHJ)structures enables to realize the favorable vertical phase separation to facilitate charge extraction and reduce charge recombination in OSCs.However,effective tunings on the power conversion efficiency(PCE)in PHJ-OSCs are still restrained by the currently available methods.Based on a polymeric donor PBDBT-2 F(PBDBT=Poly[[4,8-bis[5-(2-ethylhexyl)-4-fluoro-2-thienyl]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl]-2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxo-4 H,8 H-benzo[1,2-c:4,5-c′]dithiophene-1,3-diyl]-2,5-thiophenediyl])and a non-fullerene(NF)acceptor Y6,we proposed a strategy to improve the properties of photovoltaic performances in PHJ-based OSCs through dilute dispersions of the PBDBT-2 F donor into the acceptor-dominant phase with the sequential film deposition.With the control of donor dispersions,the charge transport balance in the PHJ-OSCs is improved,leading to the expedited photocarrier sweep-out with reduced bimolecular charge recombination.As a result,a PCE of 15.4%is achieved in the PHJ-OSCs.Importantly,the PHJ solar cells with donor dispersions exhibit better thermal stability than corresponding BHJ devices,which is related to the better film morphology robustness and less affected charge sweep-out during the thermal aging. 展开更多
关键词 diluted donor dispersion sequential film deposition vertical phase separation thermal stability
Flat limit of the de Sitter QFT in the rest frame vacuum 认领
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作者 Ion I.Cotaescu 《中国物理C:英文版》 SCIE CAS 2021年第1期97-108,共12页
The problem of the flat limits of the scalar and spinor fields on the de Sitter expanding universe is considered in the traditional adiabatic vacuum and in the new rest frame vacuum we proposed recently,in which the f... The problem of the flat limits of the scalar and spinor fields on the de Sitter expanding universe is considered in the traditional adiabatic vacuum and in the new rest frame vacuum we proposed recently,in which the frequencies are separated in the rest frames as in special relativity.It is shown that only in the rest frame vacuum can the Minkowskian flat limit be reached naturally fbr any momentum,whereas in the adiabatic vacuum,this limit remains undefined in rest frames in which the momentum vanishes.An important role is played by the phases of the fundamental solutions in the rest frame vacuum,which must be regularized to obtain the desired Minkowskian flat limits.This procedure fixes the phases of the scalar mode functions and Dirac spinors,resulting in their definitive expressions derived here.The physical consequenee is that,in the rest frame vacuum,the flat limits of the oneparticle operators are simply the corresponding operators of special relativity. 展开更多
关键词 de Sitter space-time Klein-Gordon field Dirac field flat limit approximation method phase regularization
Phase equilibrium modelling of the amphibolite facies metamorphism in the Yelapa-Chimo Metamorphic Complex, Mexico 认领
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作者 Fabian Gutierrez-Aguilar Peter Schaaf +3 位作者 Gabriela Solís-Pichardo Gerardo F.Arrieta-García Teodoro Hernandez-Trevino Carlos Linares-Lopez 《地学前缘:英文版》 SCIE CAS 2021年第1期293-312,共20页
The Yelapa-Chimo Metamorphic Complex forms part of the Jalisco Block in western Mexico and exposes a wide range of Early Cretaceous metamorphic rocks;such as paragneiss,orthogneiss,amphibolites,and migmatites.However,... The Yelapa-Chimo Metamorphic Complex forms part of the Jalisco Block in western Mexico and exposes a wide range of Early Cretaceous metamorphic rocks;such as paragneiss,orthogneiss,amphibolites,and migmatites.However,the pressure-temperature(P-T)conditions of metamorphism and partial melting remain poorly studied in the region.To elucidate metamorphic P-T conditions,phase equilibrium modelling was applied to two sillimanite-garnet paragneisses,one amphibole-orthogneiss,and one amphibolite.Sillimanite-garnet paragneisses exhibit a lepidoblastic texture with a biotite+sillimanite+kyanite+garnet+quartz+plagioclase+K-feldspar mineral assemblage.Amphibole-orthogneiss and amphibolite display a nematoblastic texture with an amphibole+(1)plagioclase+quartz+(1)titanite assemblage and an amphibole+(2)plagioclase+(2)titanite+ilmenite retrograde mineral assemblage.Pseudosections calculated for the two sillimanite-garnet paragneiss samples show P-T peak conditions at~6-7.5 kbar and~725-740℃.The results for amphibole-orthogneiss and the amphibolite yield P-T peak conditions at~8.5-10 kbar and~690-710℃.The mode models imply that metasedimentary and metaigneous units can produce up to~20 vol%and~10 vol%of melt,respectively.Modelling within a closed system during isobaric heating suggests that melt compositions of metasedimentary and metaigneous units are likely to have direct implications for the petrogenesis of the Puerto Vallarta Batholith.Our new data indicate that the Yelapa-Chimo Metamorphic Complex evolved through a metamorphic gradient between~23-33℃km^-1and the metamorphic rocks formed at depths between~22 km and~30 km with a burial rate of~2.0 km Ma^-1.Finally,the P-T data for both metasedimentary and metaigneous rocks provide new constraints on an accretionary framework,which is responsible for generating metamorphism and partial melting in the YelapaChimo Metamorphic Complex during the Early Cretaceous. 展开更多
关键词 Phase equilibrium modelling Yelapa-Chimo Metamorphic Complex Amphibolite facies Partial melting
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Fragment emission and critical behavior in light and heavy charged systems 认领
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作者 Samiksha Sood Rohit Kumar +2 位作者 Arun Sharma Sakshi Gautam Rajeev K.Puri 《中国物理C:英文版》 SCIE CAS 2021年第1期215-225,共11页
We study the emission of fragments in central collisions of light and heavily charged systems of^4+Ar+^45 Sc and^s4Kr+^197 Au,respectively,using the Quantum Molecular Dynamics(QMD)model as the primary model.The fragme... We study the emission of fragments in central collisions of light and heavily charged systems of^4+Ar+^45 Sc and^s4Kr+^197 Au,respectively,using the Quantum Molecular Dynamics(QMD)model as the primary model.The fragments are identified using an energy based clusterization algorithm,i.e.,the Simulated Annealing Clusterization Algorithm(SACA).The charge distributions of intermediate mass fragments[3≤Zf≤12]are fitted with power-law(∝Zf^-τ)and exp on ential(∝e^-λZf)fits in order to extract the parametersτandλ,whose minimum values are also sometimes linked with the onset of fragmentation or the critical point for a liquid-gas phase transition.Other parameters such as the normalized second moment<S2>,<γ2>,average size of the second largest cluster<Zmax2>,phase separation parameter(Sp),bimodal parameter(P),information entropy(H),and Zipfs law are also analyzed to find the exact energy of the onset of fragmentation.Our detailed analysis predicts that an energy point exists between 20-23.1 MeV/nucleon,which is very close to the experimentally observed value of 23.9 MeV/nucleon for the^40Ar+^45Sc reaction.We also find that the critical energy deduced using Zipfs law is higher than those predicted from other critical exponents.Moreover,no minimum is found for t values of the highly charged system of^84Kr+^197Au,in agreement with experimental findings and various theoretical calculations.We observe that the QMD+SACA model calculations are in agreement with the experimental observations.This agreement supports our results regarding the energy point of the liquid-gas phase transition and the onset of fragmentation. 展开更多
关键词 heavy-ion collisions transport model clusterization algorithm Monte-Carlo technique li・quid-gas phase transition
Behavior of phosphorus enrichment in dephosphorization slag at low temperature and low basicity 认领
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作者 Ge-fan Ye Jian Yang +2 位作者 Run-hao Zhang Wen-kui Yang Han Sun 《矿物冶金与材料学报:英文版》 SCIE EI CAS 2021年第1期66-75,共10页
At low basicity and low temperature, the dephosphorization behavior and phosphorus distribution ratio(LP) between slag and molten steel in the double slag and remaining slag process were studied with a 180 t basic oxy... At low basicity and low temperature, the dephosphorization behavior and phosphorus distribution ratio(LP) between slag and molten steel in the double slag and remaining slag process were studied with a 180 t basic oxygen furnace industrial experiment.The dephosphorization slags with different basicities were quantitatively analyzed.At the lower basicity range of 0.9–2.59, both LP and dephosphorization ratio were increased as the basicity of dephosphorization slag increased.Dephosphorization slag consisted of dark gray P-rich, light gray liquid slag,and white Fe-rich phases.With increasing basicity, not only did the morphologies of different phases in the dephosphorization slag change greatly, but the area fractions and P2O5 content of the P-rich phase also increased.The transfer route of P during dephosphorization can be deduced as hot metal → liquid slag phase + Fe-rich phase → P-rich phase. 展开更多
关键词 DEPHOSPHORIZATION BASICITY phosphorus-rich phase SLAG converter steelmaking
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Visible frequency broadband dielectric metahologram by random Fourier phase-only encoding 认领
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作者 XuYue Guo Peng Li +6 位作者 BingJie Li Sheng Liu BingYan Wei Wei Zhu JinZhan Zhong ShuXia Qi JianLin Zhao 《中国科学:物理学、力学、天文学英文版》 SCIE EI CAS 2021年第1期64-71,共8页
In recent years,metasurfaces that enable the flexible wavefront modulation at sub-wavelength scale have been widely used into holographic display,due to its prominent advantages in polarization degrees of freedom,view... In recent years,metasurfaces that enable the flexible wavefront modulation at sub-wavelength scale have been widely used into holographic display,due to its prominent advantages in polarization degrees of freedom,viewing angle,and achromaticity in comparison with traditional holographic devices.In holography,the computational complexity of hologram,imaging sharpness,energy utilization,reproduction rate,and system indirection are all determined by the encoding method.Here,we propose a visible frequency broadband dielectric metahologram based on the random Fourier phase-only encoding method.Using this simple and convenient method,we design and fabricate a transmission-type geometric phase all-dielectric metahologram,which can realize holographic display with high quality in the visible frequency range.This method encodes the amplitude information into the phase function only once,eliminating the cumbersome iterations,which greatly simplifies the calculation process,and may facilitate the preparation of large area nanoprint-holograms. 展开更多
关键词 metahologram phase random encoding imaging
铁碳合金相图分类分析 认领
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作者 彭德春 杨赵宇 +3 位作者 陈年升 周章庆 王朝 汪湘粤 《科技创新与应用》 2021年第2期55-58,共4页
铁碳合金相图是研究铁碳合金成分、温度、组织和性能之间理论关系的重要依据。文章对照铁碳相图的相区、组织、特殊点、线,详细阐述了铁碳相图的组成,分类、加热和冷却过程组织转变,为理解和记忆相图提供一定的参考。
关键词 铁碳合金 组织 相区 转变 特殊点 特殊线
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Adaptive phase field modelling of crack propagation in orthotropic functionally graded materials 认领
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作者 Hirshikesh Emilio Martínez-Paneda Sundararajan Natarajan 《Defence Technology(防务技术)》 SCIE EI CAS 2021年第1期185-195,共11页
In this work,we extend the recently proposed adaptive phase field method to model fracture in orthotropic functionally graded materials(FGMs).A recovery type error indicator combined with quadtree decomposition is emp... In this work,we extend the recently proposed adaptive phase field method to model fracture in orthotropic functionally graded materials(FGMs).A recovery type error indicator combined with quadtree decomposition is employed for adaptive mesh refinement.The proposed approach is capable of capturing the fracture process with a localized mesh refinement that provides notable gains in computational efficiency.The implementation is validated against experimental data and other numerical experiments on orthotropic materials with different material orientations.The results reveal an increase in the stiffness and the maximum force with increasing material orientation angle.The study is then extended to the analysis of orthotropic FGMs.It is observed that,if the gradation in fracture properties is neglected,the material gradient plays a secondary role,with the fracture behaviour being dominated by the orthotropy of the material.However,when the toughness increases along the crack propagation path,a substantial gain in fracture resistance is observed. 展开更多
关键词 Functionally graded materials Phase field fracture Polygonal finite element method Orthotropic materials Recovery based error indicator
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Ultrawideband chromatic aberration-free meta-mirrors 认领
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作者 Tong Cai Shiwei Tang +6 位作者 Bin Zheng Guangming Wang Wenye Ji Chao Qian Zuojia Wang Erping Li Hongsheng Chena 《Advanced Photonics》 2021年第1期47-56,共10页
Chromatic aberration-free meta-devices(e.g.,achromatic meta-devices and abnormal chromatic meta-devices)play an essential role in modern science and technology.However,current efforts suffer the issues of low efficien... Chromatic aberration-free meta-devices(e.g.,achromatic meta-devices and abnormal chromatic meta-devices)play an essential role in modern science and technology.However,current efforts suffer the issues of low efficiency,narrow operating band,and limited wavefront manipulation capability.We propose a general strategy to design chromatic aberration-free meta-devices with high-efficiency and ultrabroadband properties,which is realized by satisfying the key criteria of desirable phase dispersion and high reflection amplitudes at the target frequency interval.The phase dispersion is tuned successfully based on a multiresonant Lorentz model,and high reflection is guaranteed by the presence of the metallic ground.As proof of the concept,two microwave meta-devices are designed,fabricated,and experimentally characterized.An achromatic meta-mirror is proposed within 8 to 12 GHz,and another abnormal chromatic meta-mirror can tune the reflection angle as a linear function.Both meta-mirrors exhibit very high efficiencies(85%to 94%in the frequency band).Our findings open a door to realize chromatic aberration-free meta-devices with high efficiency and wideband properties and stimulate the realizations of chromatic aberration-free metadevices with other functionalities or working at higher frequency. 展开更多
关键词 chromatic aberration-free meta-devices ultrabroadband metasurface phase and dispersion control multiresonant Lorentz model
基于SPE与SPATT的水体中麻痹性贝类毒素检测方法构建与应用 认领
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作者 张亚亚 闫国旺 +4 位作者 吴海燕 谭志军 张志华 江涛 李玉 《海洋与湖沼》 CAS CSCD 北大核心 2020年第2期298-306,共9页
为实现麻痹性贝类毒素(paralytic shellfish poisoning,PSP)的实时监控与提前预警,本研究构建了基于固相萃取技术(solid phase extraction,SPE)与固相吸附毒素跟踪技术(solid phase adsorption toxin tracking,SPATT)的水体中PSP检测方... 为实现麻痹性贝类毒素(paralytic shellfish poisoning,PSP)的实时监控与提前预警,本研究构建了基于固相萃取技术(solid phase extraction,SPE)与固相吸附毒素跟踪技术(solid phase adsorption toxin tracking,SPATT)的水体中PSP检测方法,重点优化了吸附材料及前处理方法,评价了回收率、检出限等指标,并将方法应用于2019年春季秦皇岛山海关海域PSP消长过程的监测中,比较评估了两种方法的监控预警效果。结果表明:SPE方法选用ENVI-Carb 500mg/6mL固相萃取柱,过样体积为50mL,13种PSP组分的平均回收率为82.2%±10.0%、检出限为4.0-20.0ng/L;SPATT方法选用SP207大孔吸附树脂,洗脱时间为静置Id最佳,整体回收率约为9.2%;在实际应用中,结合产毒藻密度及贻贝富集毒素含量的变化,发现SPE方法的检测结果可实时表征海域PSP风险状况,对于贻贝中PSP的预警效果也显著优于SAPTT方法,后者不仅因监控方式相对滞后一个监测周期,且灵敏度及准确性均较差。对于秦皇岛海域,当SPE方法检测结果达到100ng STX eq/L时,该海域贻贝中PSP残留将具有潜在的食用安全风险,跟踪过程表明这一阈值可提前两周预警贻贝富集毒素含量超出我国限量标准(800μg STX eq/kg),这对于强化风险警示并制定防范措施具有积极作用。 展开更多
关键词 麻痹性贝类毒素(paralytic SHELLFISH poisoning PSP) 固相萃取技术(solid PHASE extraction SPE) 固相吸附毒素跟踪技术(solid PHASE adsorption toxin tracking SPATT) SP207大孔吸附树脂 监控预警
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The Formula of Dependence of Mechanical Characteristics of Materials on Crystalline Phase Composition in the Matrix 认领
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作者 Z. Kovziridze 《材料物理与化学进展(英文)》 2020年第8期178-188,共11页
<strong>Objective:</strong> For materials science and generally, for long-term operation of work-pieces in industry the significant role is attributed to dependence of macro-mechanical properties of consol... <strong>Objective:</strong> For materials science and generally, for long-term operation of work-pieces in industry the significant role is attributed to dependence of macro-mechanical properties of consolidated body on crystalline phase composition, its dimensions, form, distribution in matrix and the form factor. While working in responsible fields of technology of ceramics and ceramic composites the above referred properties are attributed extremely great role with the view of durability and endurance at the terms of heavy mechanical loads. For description of the resistance of any concrete type work-piece, the crystalline phase plays the greatest role in mechanical strength or deformation of any material. It plays the important role in correlative explanation of materials mechanics and matrix properties. In our case, in the process of destruction of ceramic materials and composites, which will give us exhaustive response to the role of macro- and micro-mechanical properties of materials, the role of a macro- and micro-structural component, that is, of crystalline phase in the process of transition of stable state of materials into meta-stable state is extremely big. Our study aims to develop a formula of dependence of macro-mechanical properties of ceramic and ceramic composites on crystalline phase, the most powerful component of their structure, which will enable theorists and practitioners to select and develop technologies and technological processes correctly. <strong>Method:</strong> On the basis of the study of micro- and macro-mechanical properties of ceramics and ceramic composites and the morphology of crystalline phase and the analysis of the study we determined and created parameters of the formula. <strong>Results:</strong> The formula covers macro-mechanical properties, that is when the work-piece is thoroughly destructed: mechanic at bending at three and four-point load, mechanic at contraction;among morphological characteristics: composition of crystalline phase and their spreading in matrix, t 展开更多
关键词 Crystalline Phase Macro-Mechanical Properties Mechanic at Bending Mechanic at Compaction Factor of Spreading of Crystalline Phase in Matrix
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How Do Electric and Magnetic Fields Move? 认领
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作者 Vladimir Alexander Leus 《现代物理(英文)》 2020年第2期281-284,共4页
In nature, there are two fundamentally different types of motion of the electric and magnetic fields: dynamic and kinematic. A typical manifestation of the first type of motion takes place in a plane harmonic EM-wave.... In nature, there are two fundamentally different types of motion of the electric and magnetic fields: dynamic and kinematic. A typical manifestation of the first type of motion takes place in a plane harmonic EM-wave. For already more than a century the question about the ratio of the phases of the electric and magnetic fields, oscillating in such a wave, remains open. From time to time in this regard, fierce disputes arise. The point is that far from any phase difference turns out to be compatible with the full system of Maxwellian equations. Maxwell’s classical theory as applied to such a wave leads to the conclusion that the electric and magnetic vectors in it oscillate harmoniously with zero phase shift. In the framework of this theory, a rigorous mathematical proof is given. 展开更多
关键词 Electromagnetic Wave Transverse OSCILLATIONS in Phase Longitudinal IMMOBILITY of Field VECTORS Electro-Kinematics Magneto-Kinematics
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Circular Polarization Hologram Realized by Pancharatnam-Berry Phase in Microwave Frequency 认领
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作者 Tao Yan Qian Ma Tiejun Cui 《电脑和通信(英文)》 2020年第12期134-141,共8页
<div style="text-align:justify;"> Metasurfaces have shown great potential in controlling the propagation of electromagnetic waves, making them suitable for holographic beam-shaping elements. Using the ... <div style="text-align:justify;"> Metasurfaces have shown great potential in controlling the propagation of electromagnetic waves, making them suitable for holographic beam-shaping elements. Using the principle of array synthesis, holograms have been realized in microwave frequency to manipulate electromagnetic waves to generate specific field patterns. However, current research is almost based on linear polarization and has little analysis on the circular polarization microwave hologram. Herein, we propose a circular polarization hologram realized by sub-wavelength units with self-adaptively phase profiles of electromagnetic waves. The full, continuous control of the phase is achieved by using a single structure unit based on the Pancharatnam-Berry phase. The inhomogeneity of wave-front is considered through amplitude and phase compensation which are essential to improve the quality of microwave hologram. The model achieves circular polarization hologram in microwave frequency and the clear field pattern is generated. The circular polarization hologram enriched the research field of microwave imaging, thus providing more inspirations for the development of various related techniques. </div> 展开更多
关键词 Metasurfaces Circular Polarization Hologram Pancharatnam-Berry Phase Mi-crowave Hologram
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