Utilizing Gamma-Beta function, we can build one series involving reciprocal of non-central binomial coefficients, then We can structure several new series of reciprocals of non-central binomial coefficients by item sp...Utilizing Gamma-Beta function, we can build one series involving reciprocal of non-central binomial coefficients, then We can structure several new series of reciprocals of non-central binomial coefficients by item splitting, these new created denominator of series contain 1 to 4 odd factors of binomial coefficients. As the result of splitting items, some identities of series of numbers values of reciprocals of binomial coefficients are given. The method of splitting terms offered in this paper is a new combinatorial analysis way and elementary method to create new series.展开更多
By applying the theory of formal power series,the author obtains the closed forms for two kinds of infinite series involving the reciprocals of binomial coefficients,and the author gets another closed form for the inf...By applying the theory of formal power series,the author obtains the closed forms for two kinds of infinite series involving the reciprocals of binomial coefficients,and the author gets another closed form for the infinite series Σr≥m tn＋r/（n＋rr）.展开更多
The sum of reciprocals of Mersenne primes converges to 0.51645417894078856533···, which is an example of a probably infinite subset of primes whose sum of reciprocals is finite and can be computed accur...The sum of reciprocals of Mersenne primes converges to 0.51645417894078856533···, which is an example of a probably infinite subset of primes whose sum of reciprocals is finite and can be computed accurately. This value is larger than , where ?is the set of perfect powers of prime numbers.展开更多
This paper discusses the approximation by reciprocals of polynomials with positive coefficients in Orlicz spaces and proved that if f（x） ∈ L^＊M[0, 1], changes its sign at most once in （0, 1）, then there exists ...This paper discusses the approximation by reciprocals of polynomials with positive coefficients in Orlicz spaces and proved that if f（x） ∈ L^＊M[0, 1], changes its sign at most once in （0, 1）, then there exists x0 ∈ （0, 1） and a polynomial Pn∈ Fin（＋） such that ｜｜f（x）-x-x0/Pn（x）｜｜M≤Cω（f,n-1/2）M, where Пn（＋） indicates the set of all polynomials of degree n with positive coefficients展开更多
By applying the method of on summation by parts,the purpose of this paper is to give several reciprocal summations related to squares of products of the Fibonacci numbers.
Let S^1-1,q≥2,be the surface of the unit sphere in the Euclidean space R^1,f（x）∈L^p（S^q-1）,f（x）≥0,f absohutely unegual to 0,1≤p≤＋∞,Then,it is proved in the present paper that there is a spherical harmonic...Let S^1-1,q≥2,be the surface of the unit sphere in the Euclidean space R^1,f（x）∈L^p（S^q-1）,f（x）≥0,f absohutely unegual to 0,1≤p≤＋∞,Then,it is proved in the present paper that there is a spherical harmonics PN（x） of order≤N and a constant C〉0 such that where ω（f,δ）L^p=sup 0〈t≤δ‖St（f）-f‖L^p is a kind of moduli of continuity and ^‖f-1/PN‖L^p≤Cω（f,N^-1）L^p,St（f,μ）=1/｜S^q-2｜Sin^2λt ∫-μμ’=t f（μ＇）dμ＇ is a translation operator.展开更多
Nonreciprocal isolators enable unidirectional light propagation without back-reflection.Typical terahertz isolators require magnetic fields to break the time-reversal symmetry.Herein,we propose a nonmagnetic isolator ...Nonreciprocal isolators enable unidirectional light propagation without back-reflection.Typical terahertz isolators require magnetic fields to break the time-reversal symmetry.Herein,we propose a nonmagnetic isolator in the terahertz range based on nonreciprocal graphene plasmons operated in a reflection configuration.The bias voltage generates a drift current in graphene,which breaks the time-reversal symmetry and induces nonreciprocal reflection.The isolator device exhibited a high isolation exceeding 20 d B with an insertion loss of less than 3 d B.Moreover,the bandwidth wit isolation exceeding 20 d B can be broadened five times to 1.7 THz by tuning the carrier density.The indexes,including the isolation,insertion loss and bandwidth of the isolator,show a strong dependence on the drift velocity and mobility of graphene,as well as the air-gap thickness.Our study shows great potential in the burgeoning terahertz technology,where nonmagnetic and electrically tunable isolators are still lacking.展开更多
The interaction between the gut microbiota and cyclic adenosine monophosphate(cAMP)-protein kinase A(PKA)signaling pathway in the host's central nervous system plays a crucial role in neurological diseases and enh...The interaction between the gut microbiota and cyclic adenosine monophosphate(cAMP)-protein kinase A(PKA)signaling pathway in the host's central nervous system plays a crucial role in neurological diseases and enhances communication along the gut–brain axis.The gut microbiota influences the cAMP-PKA signaling pathway through its metabolites,which activates the vagus nerve and modulates the immune and neuroendocrine systems.Conversely,alterations in the cAMP-PKA signaling pathway can affect the composition of the gut microbiota,creating a dynamic network of microbial-host interactions.This reciprocal regulation affects neurodevelopment,neurotransmitter control,and behavioral traits,thus playing a role in the modulation of neurological diseases.The coordinated activity of the gut microbiota and the cAMP-PKA signaling pathway regulates processes such as amyloid-β protein aggregation,mitochondrial dysfunction,abnormal energy metabolism,microglial activation,oxidative stress,and neurotransmitter release,which collectively influence the onset and progression of neurological diseases.This study explores the complex interplay between the gut microbiota and cAMP-PKA signaling pathway,along with its implications for potential therapeutic interventions in neurological diseases.Recent pharmacological research has shown that restoring the balance between gut flora and cAMP-PKA signaling pathway may improve outcomes in neurodegenerative diseases and emotional disorders.This can be achieved through various methods such as dietary modifications,probiotic supplements,Chinese herbal extracts,combinations of Chinese herbs,and innovative dosage forms.These findings suggest that regulating the gut microbiota and cAMP-PKA signaling pathway may provide valuable evidence for developing novel therapeutic approaches for neurodegenerative diseases.展开更多
A new stirring method,reciprocating stirring,is developed by incorporating a periodic axial reciprocating motion into conventional stirring.This study employs computational fluid dynamics methods,utilizing volume of f...A new stirring method,reciprocating stirring,is developed by incorporating a periodic axial reciprocating motion into conventional stirring.This study employs computational fluid dynamics methods,utilizing volume of fluid and user-defined functions to control and analyze the flow field characteristics in a reciprocating stirred tank.Compared to conventional stirring,reciprocating stirring increases the overall fluid velocity by approximately 7.9%,turbulent kinetic energy(TKE)by 35.9%to 45.6%,and the turbulent dissipation rate by 10.6%to 15.7%.The primary reason is the dynamic integration of multiple flow regions,which enhances fluid interface interactions.Additionally,the study investigates the dynamic evolution of the vortex structure,uncovering the correlation between the impeller's start-stop behavior and the vortex area.The optimal impeller plate designs,forward sine-4/12D and reverse sine-5/12D,were determined based on the effective area of TKE.Reciprocating stirring,in comparison to conventional stirring,enhances secondary flow intensity by 67.3%to 93.7%and shortens mixing time by 56.6%to 173.0%.展开更多
The U.S.imposition of high tariffs on Chinese goods has triggered short-term strains on China’s exports.At the same time,it has also accelerated its strategic pivot toward technological self-reliance,regional integra...The U.S.imposition of high tariffs on Chinese goods has triggered short-term strains on China’s exports.At the same time,it has also accelerated its strategic pivot toward technological self-reliance,regional integration,and domestic demand expansion.展开更多
The vectorial evolution of light polarization can reveal the microstructure and anisotropy of a medium beyond what can be obtained from measuring light intensity alone.However,polarization imaging in reflection geomet...The vectorial evolution of light polarization can reveal the microstructure and anisotropy of a medium beyond what can be obtained from measuring light intensity alone.However,polarization imaging in reflection geometry,which is ubiquitous and often preferred in diverse applications,has often suffered from poor and even incorrect characterization of anisotropic media.We present reciprocal polarization imaging of complex media in reflection geometry with the reciprocal polar decomposition of backscattering Mueller matrices enforcing reciprocity.We demonstrate that reciprocal polarization imaging of complex chiral and anisotropic media ac-curately quantifies their anisotropic properties in reflection geometry,whereas traditional approaches encounter difficulties and produce inferior and often erroneous results from the violation of reciprocity.In particular,reciprocal polarization imaging provides a consistent characterization of complex media of different thicknesses,accurately measures the optical activity and glucose concentration of turbid media in reflection,and discriminates between cancerous and normal tissue with even stronger contrast than forward measurement.Reciprocal polarization imaging promises broad applications of polarization optics ranging from remote sensing to bio-medicine in reflection geometries,especially in in vivo biomedical imaging,where reflection is the only feasible geometry.展开更多
Root resorption is a significant complication in orthodontic treatment,with thin roots and reciprocal movement being recognized as high-risk factors.This paper reports a case of a 19-year-old female patient who underw...Root resorption is a significant complication in orthodontic treatment,with thin roots and reciprocal movement being recognized as high-risk factors.This paper reports a case of a 19-year-old female patient who underwent orthodontic treatment for dental irregularity.The patient had thin roots in the maxillary lateral incisors 12 and 22.During treatment,tooth 22 experienced reciprocal movement of labial expansion followed by retraction,while tooth 12 adopted passive ligation to reduce reciprocal movement.After 23 months of straight-wire extraction treatment,good occlusal relationships were achieved,but significant root resorption occurred in teeth 12 and 22,with tooth 22 showing more severe resorption.This case confirms the synergistic effect between thin roots and reciprocal movement,demonstrating that thin roots are more sensitive to reciprocal movement stimulation,producing a synergistic amplification effect.Additionally,standardized nursing guidance and patient compliance management play important roles in reducing resorption risk.This case emphasizes the importance of pretreatment risk assessment,individualized treatment strategy formulation,and comprehensive nursing intervention throughout treatment,providing reference for clinical prevention of root resorption.展开更多
The evolution mechanism of the second-order mechanical behaviors under the complex pre-torsion path has not been clarified,which limits its potential application for optimizing precision forming processes of Mg alloy ...The evolution mechanism of the second-order mechanical behaviors under the complex pre-torsion path has not been clarified,which limits its potential application for optimizing precision forming processes of Mg alloy structural components.In this work,the combined loading of reciprocating free-end torsion(FET)and free-rotational tension(FRT)was performed on the extruded AZ31 solid rod with basal fiber texture.The corresponding mechanical response,microstructure evolution,and twinning behaviors were investigated,and the physical mechanism of the second-order behaviors(both the Swift and inverse Swift effects)was discussed.The results indicate that the two-stage deformation of reciprocating torsion is capable of activating tensile twins,effectively refining the surface grains,and thus improving the yield asymmetry.Due to the reverse load,detwinning dominates the deformation of reverse FET(RFET),while detwinning in FRT deformation is caused by the spontaneous rotation of the inverse Swift effect.The twin variants with c-axis tending to extrusion direction(ED)are predisposed to detwinning,and the bimodal texture introduced by FET is degraded.The plastic deformation of RFET is primarily coordinated by basal and prismatic slips.The large strain FRT is dominated by basal slip due to its low SF/CRSS.The interaction between twinning and detwinning dominates the multi-directionality of the Swift effect during reciprocating torsion,and the cumulative effect of strain hardening further enhances the dependence of RFET axial strain on basal slip.The dγ/dεindex successfully captures the evolution of the inverse Swift effect during FRT.The forward rotation of the solid rod is caused by the inversion of the radial residual shear stress field,and the internal stress introduced by the torsional inhomogeneity is compensated.The subsequent reverse rotation is the result of balancing the orientation inhomogeneity and local strain heterogeneity introduced by the shear deformation.The increase in the reverse rotation rate is caused by detwinning.展开更多
Animal adaptation to environmental challenges is a complex process involving intricate interactions between the host genotype and gut microbiome composition.The gut microbiome,highly responsive to external environment...Animal adaptation to environmental challenges is a complex process involving intricate interactions between the host genotype and gut microbiome composition.The gut microbiome,highly responsive to external environmental factors,plays a crucial role in host adaptability and may facilitate local adaptation within species.Concurrently,the genetic background of host populations influences gut microbiome composition,highlighting the bidirectional relationship between host and microbiome.Despite this,our understanding of gut microbiome plasticity and its role in host adaptability remains limited,particularly in reptiles.To clarify this issue,we conducted a reciprocal translocation experiment with gravid females of the Qinghai toad-headed lizards(Phrynocephalus vlangalii)between high-altitude(2?600 m a.s.l.)and superhigh-altitude(3?600 m a.s.l.)environments on Dangjin Mountain of the Qinghai-Xizang Plateau,China.One year later,we assessed the phenotypes and gut microbiomes of their offspring.Results revealed significant plasticity in gut microbiome diversity and structure in response to contrasting elevations.Highaltitude conditions increased diversity,and maternal effects appeared to enable high-altitude lizards to maintain elevated diversity when exposed to superhigh-altitude environments.Additionally,superhigh-altitude lizards displayed distinct gut microbiome structures with notable host specificity,potentially linked to their lower growth rates.Overall,these findings underscore the importance of the gut microbiome in facilitating reptilian adaptation to rapid environmental changes across altitudinal gradients.Furthermore,this study provides critical insights into microbial mechanisms underpinning local adaptation and adaptative plasticity,offering a foundation for future research on host-microbiome interactions in evolutionary and ecological contexts.展开更多
From April 14 to 18,Chinese President Xi Jinping made state visits to Vietnam,Malaysia,and Cambodia.This tour coincided with global upheaval caused by“reciprocal tariffs”imposed by U.S.President Donald Trump,which t...From April 14 to 18,Chinese President Xi Jinping made state visits to Vietnam,Malaysia,and Cambodia.This tour coincided with global upheaval caused by“reciprocal tariffs”imposed by U.S.President Donald Trump,which turned global eyes towards China and Southeast Asian nations to see how they would strengthen cooperation and respond to the“Trump effect.”展开更多
On April 2,the United States announced the implementation of the so-called“reciprocal tariffs”plan.Combined with factors such as the OPEC+plan to increase production starting in May,this led to a continuous plunge i...On April 2,the United States announced the implementation of the so-called“reciprocal tariffs”plan.Combined with factors such as the OPEC+plan to increase production starting in May,this led to a continuous plunge in the benchmark oil prices of WTI and Brent over the subsequent three trading days.Despite the significant impact of the United States’“reciprocal tariffs”plan on the global political and economic landscape,the fundamental dynamics of supply and demand remain the decisive factors in the fluctuations of international oil prices.The current trend of international oil price fluctuations is still primarily driven by the supply side,with both supply and demand factors playing a role.Investment,costs,and resource constraints on the supply side do not allow for a significant increase in crude oil production,while“consumption rigidity”on the demand side does not permit a significant decrease in crude oil demand.As a result,International oil prices are expected to fluctuate in the short term,but a significant decline is unlikely to be sustained in the near to medium term.In this context,Chinese oil companies should focus on four key areas to ensure the security of national oil and gas supplies:first,promoting high-quality increases in domestic oil and gas reserves and production;second,steadily strengthening the acquisition of overseas oil and gas resources;third,continuously driving innovation in oil and gas exploration and development technologies;fourth,enhancing the capacity for domestic oil and gas reserves in an orderly manner.展开更多
This paper introduces a new method based on deep belief networks(DBNs)to integrate intrinsic vibration information and assess the similarity of subspaces established on the Grassmann manifold for intelligent fault dia...This paper introduces a new method based on deep belief networks(DBNs)to integrate intrinsic vibration information and assess the similarity of subspaces established on the Grassmann manifold for intelligent fault diagnosis of a reciprocating compressor(RC).Initially,raw vibration signals undergo empirical mode decomposition to break them down into multiple intrinsic mode functions(IMFs).This operation can reveal inherent vibration patterns of fault and other components hidden in the original signals.Subsequently,features are refined from all the IMFs and concatenated into a high-dimensional representative vector,offering localized and comprehensive insights into RC operation.Through DBN,the fault-sensitive information is further refined from the features to enhance their performance in fault identification.Finally,similarities among subspaces on the Grassmann manifold are computed to match fault types.The efficacy of the method is validated usingfield data.Comparative analysis with traditional approaches for feature dimension reduction,feature extraction,and Euclidean distance-based fault identification underscores the effectiveness and superiority of the proposed method in RC fault diagnosis.展开更多
Satellite communication plays an important role in 6G systems.However,satellite communication systems are more susceptible to intentional or unintentional interference signals than other communication systems because ...Satellite communication plays an important role in 6G systems.However,satellite communication systems are more susceptible to intentional or unintentional interference signals than other communication systems because of their working mechanism of transparent forwarding.For the purpose of eliminating the influence of interference,this paper develops an angle reciprocal interference suppression scheme based on the reconstruction of interferenceplus-noise covariance matrix(ARIS-RIN).Firstly,we utilize the reciprocity between the known beam central angle and the unknown signal arrival angle to estimate the angle of arrival(AOA)of desired signal due to the multi-beam coverage.Then,according to the priori known spatial spectrum distribution,the interferenceplus-noise covariance matrix(INCM)is reconstructed by integrating within the range except the direction of desired signal.In order to correct the estimation bias of the first two steps,the worst-case performance optimization technology is adopted in the process of solving the beamforming vector.Numerical simulation results show that the developed scheme:1)has a higher output signal-to-interference-plus-noise ratio(SINR)under arbitrary signal-to-noise ratio(SNR);2)still has good performance under small snapshots;3)is robuster and easier to be realized when comparing with minimum variance distortionless response(MVDR)and the traditional diagonal loading algorithms.展开更多
文摘Utilizing Gamma-Beta function, we can build one series involving reciprocal of non-central binomial coefficients, then We can structure several new series of reciprocals of non-central binomial coefficients by item splitting, these new created denominator of series contain 1 to 4 odd factors of binomial coefficients. As the result of splitting items, some identities of series of numbers values of reciprocals of binomial coefficients are given. The method of splitting terms offered in this paper is a new combinatorial analysis way and elementary method to create new series.
基金Supported by the NNSF of China(10771093)Supported by the NSF of Henan Province(0511010300)
文摘By applying the theory of formal power series,the author obtains the closed forms for two kinds of infinite series involving the reciprocals of binomial coefficients,and the author gets another closed form for the infinite series Σr≥m tn＋r/（n＋rr）.
文摘The sum of reciprocals of Mersenne primes converges to 0.51645417894078856533···, which is an example of a probably infinite subset of primes whose sum of reciprocals is finite and can be computed accurately. This value is larger than , where ?is the set of perfect powers of prime numbers.
基金Supported by Inner Mongolia Natural Science Foundations of China (200408020108).
文摘This paper discusses the approximation by reciprocals of polynomials with positive coefficients in Orlicz spaces and proved that if f（x） ∈ L^＊M[0, 1], changes its sign at most once in （0, 1）, then there exists x0 ∈ （0, 1） and a polynomial Pn∈ Fin（＋） such that ｜｜f（x）-x-x0/Pn（x）｜｜M≤Cω（f,n-1/2）M, where Пn（＋） indicates the set of all polynomials of degree n with positive coefficients
基金Supported by the Natural Science Foundation of Henan Province(0511010300)Supported by the Natural Science Foundation of Education Department of Henan Province(2008B110011)
文摘By applying the method of on summation by parts,the purpose of this paper is to give several reciprocal summations related to squares of products of the Fibonacci numbers.
基金Supported by the National Natural Science Foundation of China （No.10371024）, the Natural Science of Zhejiang Province （No. Y604003） and the Doctor Foundation of Ningbo City （No.2004A620017）.
文摘Let S^1-1,q≥2,be the surface of the unit sphere in the Euclidean space R^1,f（x）∈L^p（S^q-1）,f（x）≥0,f absohutely unegual to 0,1≤p≤＋∞,Then,it is proved in the present paper that there is a spherical harmonics PN（x） of order≤N and a constant C〉0 such that where ω（f,δ）L^p=sup 0〈t≤δ‖St（f）-f‖L^p is a kind of moduli of continuity and ^‖f-1/PN‖L^p≤Cω（f,N^-1）L^p,St（f,μ）=1/｜S^q-2｜Sin^2λt ∫-μμ’=t f（μ＇）dμ＇ is a translation operator.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11934011 and 12274365)National Key R&D Program of China(Grant Nos.2022YFA1402400 and 2022YFA1400043)+1 种基金Zhejiang Provincial Natural Science Foundation of China(Grant No.LR24A040001)Open project of Key Laboratory of Artificial Structures and Quantum Control(Ministry of Education)of Shanghai Jiao Tong University。
文摘Nonreciprocal isolators enable unidirectional light propagation without back-reflection.Typical terahertz isolators require magnetic fields to break the time-reversal symmetry.Herein,we propose a nonmagnetic isolator in the terahertz range based on nonreciprocal graphene plasmons operated in a reflection configuration.The bias voltage generates a drift current in graphene,which breaks the time-reversal symmetry and induces nonreciprocal reflection.The isolator device exhibited a high isolation exceeding 20 d B with an insertion loss of less than 3 d B.Moreover,the bandwidth wit isolation exceeding 20 d B can be broadened five times to 1.7 THz by tuning the carrier density.The indexes,including the isolation,insertion loss and bandwidth of the isolator,show a strong dependence on the drift velocity and mobility of graphene,as well as the air-gap thickness.Our study shows great potential in the burgeoning terahertz technology,where nonmagnetic and electrically tunable isolators are still lacking.
基金supported by the National Natural Science Foundation of China,No.82003965the Science and Technology Research Project of Sichuan Provincial Administration of Traditional Chinese Medicine,No.2024MS167(to LH)+2 种基金the Xinglin Scholar Program of Chengdu University of Traditional Chinese Medicine,No.QJRC2022033(to LH)the Improvement Plan for the'Xinglin Scholar'Scientific Research Talent Program at Chengdu University of Traditional Chinese Medicine,No.XKTD2023002(to LH)the 2023 National Project of the College Students'Innovation and Entrepreneurship Training Program at Chengdu University of Traditional Chinese Medicine,No.202310633028(to FD)。
文摘The interaction between the gut microbiota and cyclic adenosine monophosphate(cAMP)-protein kinase A(PKA)signaling pathway in the host's central nervous system plays a crucial role in neurological diseases and enhances communication along the gut–brain axis.The gut microbiota influences the cAMP-PKA signaling pathway through its metabolites,which activates the vagus nerve and modulates the immune and neuroendocrine systems.Conversely,alterations in the cAMP-PKA signaling pathway can affect the composition of the gut microbiota,creating a dynamic network of microbial-host interactions.This reciprocal regulation affects neurodevelopment,neurotransmitter control,and behavioral traits,thus playing a role in the modulation of neurological diseases.The coordinated activity of the gut microbiota and the cAMP-PKA signaling pathway regulates processes such as amyloid-β protein aggregation,mitochondrial dysfunction,abnormal energy metabolism,microglial activation,oxidative stress,and neurotransmitter release,which collectively influence the onset and progression of neurological diseases.This study explores the complex interplay between the gut microbiota and cAMP-PKA signaling pathway,along with its implications for potential therapeutic interventions in neurological diseases.Recent pharmacological research has shown that restoring the balance between gut flora and cAMP-PKA signaling pathway may improve outcomes in neurodegenerative diseases and emotional disorders.This can be achieved through various methods such as dietary modifications,probiotic supplements,Chinese herbal extracts,combinations of Chinese herbs,and innovative dosage forms.These findings suggest that regulating the gut microbiota and cAMP-PKA signaling pathway may provide valuable evidence for developing novel therapeutic approaches for neurodegenerative diseases.
基金National Key Research and Development Program of China(2022YFC3902000)Yunnan Major Scientific and Technological Projects(202202AG050002,202202AG050007)National Natural Science Foundation of China(52166004).
文摘A new stirring method,reciprocating stirring,is developed by incorporating a periodic axial reciprocating motion into conventional stirring.This study employs computational fluid dynamics methods,utilizing volume of fluid and user-defined functions to control and analyze the flow field characteristics in a reciprocating stirred tank.Compared to conventional stirring,reciprocating stirring increases the overall fluid velocity by approximately 7.9%,turbulent kinetic energy(TKE)by 35.9%to 45.6%,and the turbulent dissipation rate by 10.6%to 15.7%.The primary reason is the dynamic integration of multiple flow regions,which enhances fluid interface interactions.Additionally,the study investigates the dynamic evolution of the vortex structure,uncovering the correlation between the impeller's start-stop behavior and the vortex area.The optimal impeller plate designs,forward sine-4/12D and reverse sine-5/12D,were determined based on the effective area of TKE.Reciprocating stirring,in comparison to conventional stirring,enhances secondary flow intensity by 67.3%to 93.7%and shortens mixing time by 56.6%to 173.0%.
文摘The U.S.imposition of high tariffs on Chinese goods has triggered short-term strains on China’s exports.At the same time,it has also accelerated its strategic pivot toward technological self-reliance,regional integration,and domestic demand expansion.
基金upported by the Natural Science Foundation of Zhejiang Province(Grant No.LZ16H180002)the National Natural Science Foundation of China(Grant No.61905181)+1 种基金the Wenzhou Municipal Science and Technology Bureau(Grant No.ZS2017022)the National Science Foundation of the U.S.(Grant No.1607664).
文摘The vectorial evolution of light polarization can reveal the microstructure and anisotropy of a medium beyond what can be obtained from measuring light intensity alone.However,polarization imaging in reflection geometry,which is ubiquitous and often preferred in diverse applications,has often suffered from poor and even incorrect characterization of anisotropic media.We present reciprocal polarization imaging of complex media in reflection geometry with the reciprocal polar decomposition of backscattering Mueller matrices enforcing reciprocity.We demonstrate that reciprocal polarization imaging of complex chiral and anisotropic media ac-curately quantifies their anisotropic properties in reflection geometry,whereas traditional approaches encounter difficulties and produce inferior and often erroneous results from the violation of reciprocity.In particular,reciprocal polarization imaging provides a consistent characterization of complex media of different thicknesses,accurately measures the optical activity and glucose concentration of turbid media in reflection,and discriminates between cancerous and normal tissue with even stronger contrast than forward measurement.Reciprocal polarization imaging promises broad applications of polarization optics ranging from remote sensing to bio-medicine in reflection geometries,especially in in vivo biomedical imaging,where reflection is the only feasible geometry.
文摘Root resorption is a significant complication in orthodontic treatment,with thin roots and reciprocal movement being recognized as high-risk factors.This paper reports a case of a 19-year-old female patient who underwent orthodontic treatment for dental irregularity.The patient had thin roots in the maxillary lateral incisors 12 and 22.During treatment,tooth 22 experienced reciprocal movement of labial expansion followed by retraction,while tooth 12 adopted passive ligation to reduce reciprocal movement.After 23 months of straight-wire extraction treatment,good occlusal relationships were achieved,but significant root resorption occurred in teeth 12 and 22,with tooth 22 showing more severe resorption.This case confirms the synergistic effect between thin roots and reciprocal movement,demonstrating that thin roots are more sensitive to reciprocal movement stimulation,producing a synergistic amplification effect.Additionally,standardized nursing guidance and patient compliance management play important roles in reducing resorption risk.This case emphasizes the importance of pretreatment risk assessment,individualized treatment strategy formulation,and comprehensive nursing intervention throughout treatment,providing reference for clinical prevention of root resorption.
基金supported by the National Natural Science Foundation of China(Nos.51771166,52225101)Fundamental Research Funds for the Central Universities(No.2023CDJYXTD-002)+1 种基金Cultivation Project for Basic Research and In-novation of Yanshan University(No.2021LGZD002)Project of State Key Laboratory of Materials Processing and Die&Mould Technology(No.P2023-004).
文摘The evolution mechanism of the second-order mechanical behaviors under the complex pre-torsion path has not been clarified,which limits its potential application for optimizing precision forming processes of Mg alloy structural components.In this work,the combined loading of reciprocating free-end torsion(FET)and free-rotational tension(FRT)was performed on the extruded AZ31 solid rod with basal fiber texture.The corresponding mechanical response,microstructure evolution,and twinning behaviors were investigated,and the physical mechanism of the second-order behaviors(both the Swift and inverse Swift effects)was discussed.The results indicate that the two-stage deformation of reciprocating torsion is capable of activating tensile twins,effectively refining the surface grains,and thus improving the yield asymmetry.Due to the reverse load,detwinning dominates the deformation of reverse FET(RFET),while detwinning in FRT deformation is caused by the spontaneous rotation of the inverse Swift effect.The twin variants with c-axis tending to extrusion direction(ED)are predisposed to detwinning,and the bimodal texture introduced by FET is degraded.The plastic deformation of RFET is primarily coordinated by basal and prismatic slips.The large strain FRT is dominated by basal slip due to its low SF/CRSS.The interaction between twinning and detwinning dominates the multi-directionality of the Swift effect during reciprocating torsion,and the cumulative effect of strain hardening further enhances the dependence of RFET axial strain on basal slip.The dγ/dεindex successfully captures the evolution of the inverse Swift effect during FRT.The forward rotation of the solid rod is caused by the inversion of the radial residual shear stress field,and the internal stress introduced by the torsional inhomogeneity is compensated.The subsequent reverse rotation is the result of balancing the orientation inhomogeneity and local strain heterogeneity introduced by the shear deformation.The increase in the reverse rotation rate is caused by detwinning.
基金supported by the National Natural Science Foundation of China (31861143023,31872252)Strategic Priority Research Program of the Chinese Academy of Sciences (XDA20050201)。
文摘Animal adaptation to environmental challenges is a complex process involving intricate interactions between the host genotype and gut microbiome composition.The gut microbiome,highly responsive to external environmental factors,plays a crucial role in host adaptability and may facilitate local adaptation within species.Concurrently,the genetic background of host populations influences gut microbiome composition,highlighting the bidirectional relationship between host and microbiome.Despite this,our understanding of gut microbiome plasticity and its role in host adaptability remains limited,particularly in reptiles.To clarify this issue,we conducted a reciprocal translocation experiment with gravid females of the Qinghai toad-headed lizards(Phrynocephalus vlangalii)between high-altitude(2?600 m a.s.l.)and superhigh-altitude(3?600 m a.s.l.)environments on Dangjin Mountain of the Qinghai-Xizang Plateau,China.One year later,we assessed the phenotypes and gut microbiomes of their offspring.Results revealed significant plasticity in gut microbiome diversity and structure in response to contrasting elevations.Highaltitude conditions increased diversity,and maternal effects appeared to enable high-altitude lizards to maintain elevated diversity when exposed to superhigh-altitude environments.Additionally,superhigh-altitude lizards displayed distinct gut microbiome structures with notable host specificity,potentially linked to their lower growth rates.Overall,these findings underscore the importance of the gut microbiome in facilitating reptilian adaptation to rapid environmental changes across altitudinal gradients.Furthermore,this study provides critical insights into microbial mechanisms underpinning local adaptation and adaptative plasticity,offering a foundation for future research on host-microbiome interactions in evolutionary and ecological contexts.
文摘From April 14 to 18,Chinese President Xi Jinping made state visits to Vietnam,Malaysia,and Cambodia.This tour coincided with global upheaval caused by“reciprocal tariffs”imposed by U.S.President Donald Trump,which turned global eyes towards China and Southeast Asian nations to see how they would strengthen cooperation and respond to the“Trump effect.”
文摘On April 2,the United States announced the implementation of the so-called“reciprocal tariffs”plan.Combined with factors such as the OPEC+plan to increase production starting in May,this led to a continuous plunge in the benchmark oil prices of WTI and Brent over the subsequent three trading days.Despite the significant impact of the United States’“reciprocal tariffs”plan on the global political and economic landscape,the fundamental dynamics of supply and demand remain the decisive factors in the fluctuations of international oil prices.The current trend of international oil price fluctuations is still primarily driven by the supply side,with both supply and demand factors playing a role.Investment,costs,and resource constraints on the supply side do not allow for a significant increase in crude oil production,while“consumption rigidity”on the demand side does not permit a significant decrease in crude oil demand.As a result,International oil prices are expected to fluctuate in the short term,but a significant decline is unlikely to be sustained in the near to medium term.In this context,Chinese oil companies should focus on four key areas to ensure the security of national oil and gas supplies:first,promoting high-quality increases in domestic oil and gas reserves and production;second,steadily strengthening the acquisition of overseas oil and gas resources;third,continuously driving innovation in oil and gas exploration and development technologies;fourth,enhancing the capacity for domestic oil and gas reserves in an orderly manner.
文摘This paper introduces a new method based on deep belief networks(DBNs)to integrate intrinsic vibration information and assess the similarity of subspaces established on the Grassmann manifold for intelligent fault diagnosis of a reciprocating compressor(RC).Initially,raw vibration signals undergo empirical mode decomposition to break them down into multiple intrinsic mode functions(IMFs).This operation can reveal inherent vibration patterns of fault and other components hidden in the original signals.Subsequently,features are refined from all the IMFs and concatenated into a high-dimensional representative vector,offering localized and comprehensive insights into RC operation.Through DBN,the fault-sensitive information is further refined from the features to enhance their performance in fault identification.Finally,similarities among subspaces on the Grassmann manifold are computed to match fault types.The efficacy of the method is validated usingfield data.Comparative analysis with traditional approaches for feature dimension reduction,feature extraction,and Euclidean distance-based fault identification underscores the effectiveness and superiority of the proposed method in RC fault diagnosis.
基金supported by the National Natural Science Foundation of China under Grants No.61671367 and 62471381the Research Foundation of Science and Technology on Communication Networks Laboratory,and the National Key Laboratory of Wireless Communications Foundation under Grant No.IFN202401.
文摘Satellite communication plays an important role in 6G systems.However,satellite communication systems are more susceptible to intentional or unintentional interference signals than other communication systems because of their working mechanism of transparent forwarding.For the purpose of eliminating the influence of interference,this paper develops an angle reciprocal interference suppression scheme based on the reconstruction of interferenceplus-noise covariance matrix(ARIS-RIN).Firstly,we utilize the reciprocity between the known beam central angle and the unknown signal arrival angle to estimate the angle of arrival(AOA)of desired signal due to the multi-beam coverage.Then,according to the priori known spatial spectrum distribution,the interferenceplus-noise covariance matrix(INCM)is reconstructed by integrating within the range except the direction of desired signal.In order to correct the estimation bias of the first two steps,the worst-case performance optimization technology is adopted in the process of solving the beamforming vector.Numerical simulation results show that the developed scheme:1)has a higher output signal-to-interference-plus-noise ratio(SINR)under arbitrary signal-to-noise ratio(SNR);2)still has good performance under small snapshots;3)is robuster and easier to be realized when comparing with minimum variance distortionless response(MVDR)and the traditional diagonal loading algorithms.
