Compressing all the energy of a laser pulse into a spatiotemporal focal cube edged by the laser center wavelength will realize the highest intensity of an ultra-intense ultrashort laser,which is called theλ^(3) regim...Compressing all the energy of a laser pulse into a spatiotemporal focal cube edged by the laser center wavelength will realize the highest intensity of an ultra-intense ultrashort laser,which is called theλ^(3) regime or theλ^(3) laser.Herein,we introduced a rotational hyperbolic mirror—an important rotational conic section mirror with two foci—that is used as a secondary focusing mirror after a rotational parabolic mirror to reduce the focal spot size from several wavelengths to a single wavelength by significantly increasing the focusing angular aperture.Compared with the rotational ellipsoidal mirror,the first focal spot with a high intensity,as well as some unwanted strong-field effects,is avoided.The optimal focusing condition of this method is presented and the enhanced tight focusing for a femtosecond petawatt laser and theλ3 laser is numerically simulated,which can enhance the focused intensities of ultra-intense ultrashort lasers for laser physics.展开更多
Research on adaptive deformable mirror technology for voice coil actuators(VCAs)is an important trend in the development of large ground-based telescopes.A voice coil adaptive deformable mirror contains a large number...Research on adaptive deformable mirror technology for voice coil actuators(VCAs)is an important trend in the development of large ground-based telescopes.A voice coil adaptive deformable mirror contains a large number of actuators,and there are problems with structural coupling and large temperature increases in their internal coils.Additionally,parameters of the traditional proportional integral derivative(PID)control cannot be adjusted in real-time to adapt to system changes.These problems can be addressed by introducing fuzzy control methods.A table lookup method is adopted to replace real-time calculations of the regular fuzzy controller during the control process,and a prototype platform has been established to verify the effectiveness and robustness of this process.Experimental tests compare the control performance of traditional and fuzzy proportional integral derivative(Fuzzy-PID)controllers,showing that,in system step response tests,the fuzzy control system reduces rise time by 20.25%,decreases overshoot by 78.24%,and shortens settling time by 67.59%.In disturbance rejection experiments,fuzzy control achieves a 46.09%reduction in the maximum deviation,indicating stronger robustness.The Fuzzy-PID controller,based on table lookup,outperforms the standard controller significantly,showing excellent potential for enhancing the dynamic performance and disturbance rejection capability of the voice coil motor actuator system.展开更多
First mirror(FM)cleaning,using radio frequency(RF)plasma,has been proposed to recover FM reflectivity in nuclear fusion reactors such as the International Thermonuclear Experimental Reactor(ITER).To investigate the in...First mirror(FM)cleaning,using radio frequency(RF)plasma,has been proposed to recover FM reflectivity in nuclear fusion reactors such as the International Thermonuclear Experimental Reactor(ITER).To investigate the influence of simultaneous cleaning of two mirrors on mirror cleaning efficiency and uniformity,experiments involving single-mirror cleaning and dual-mirror cleaning were conducted using RF capacitively coupled plasma in the laboratory.For the test and simultaneous cleaning of two mirrors,the FM and second mirror(SM),both measuring 110 mm×80 mm,were placed inside the first mirror unit(FMU).They were composed of 16 mirror samples,each with a dimension of 27.5 mm×20 mm.These mirror samples consist of a titanium-zirconium-molybdenum alloy substrate,a 500 nm Mo intermediate layer and a 30 nm Al_(2)O_(3) surface coating as a proxy for Be impurities.The cleaning of a single first mirror(SFM)and the simultaneous cleaning of the FM and SM(DFM and DSM)lasted for 9 h using Ar plasma at a pressure of 1 Pa.The total reflectivity of mirror samples on the DSM did not fully recover and varied with location,with a self-bias of−140 V.With a self-bias of−300 V,the total reflectivity of mirror samples on the SFM and DFM was fully recovered.The energy dispersive spectrometer results demonstrated that the Al_(2)O_(3) coating had been completely removed from these mirror samples.However,the mass loss of each mirror sample on the SFM and DFM before and after cleaning varied depending on its location,with higher mass loss observed for mirror samples located in the corners and lower loss for those in the center.Compared with SM cleaning,the simultaneous cleaning of two mirrors reduced the difference between the highest and lowest mass loss.Furthermore,this mass loss for the mirror samples of the DFM facing the DSM was increased.This indicated that mirror samples cleaned face to face in the FMU simultaneously could influence each other,highlighting the need for special attention in future studies.展开更多
A novel method to characterize CMOS process fluctuations in subthreshold current mirrors （SCM） is reported. The proposed model is succinct in methodology and calculation complexity compared with previous statistical...A novel method to characterize CMOS process fluctuations in subthreshold current mirrors （SCM） is reported. The proposed model is succinct in methodology and calculation complexity compared with previous statistical models. However,it provides favorable estimations of CMOS process fluctuations on the SCM circuit, which makes it promising for engineering applications. The model statistically abstracts physical parameters, which depend on the IC process, into random variables with certain mean values and standard deviations, while aggregating all the random impacts into a discrete martingale. The correctness of the proposed method is experimentally verified on an SCM circuit implemented in an SMIC 0.18μm CMOS 1P6M mixed signal process with a conversion factor of 100 in an input range from 100pA to lμA. The pro- posed theory successfully predicts - 10% of die-to-die fluctuation measured in the experiment, and also suggests the -lmV of threshold voltage standard deviation over a single die,which meets the process parameters suggested by the design kit from the foundry. The deviations between calculated probabilities and measured data are less than 8%. Meanwhile, pertinent suggestions concerning high fluctuation tolerance subthreshold analog circuit design are also made and discussed.展开更多
X-ray diffaction analysis(XRDA)data of the black or brown patina on the surfaces of eight kinds of bronze mirror samples show 4 or 5 broad diffuse peaks which corresponding to almost the same 20 angle, while their mat...X-ray diffaction analysis(XRDA)data of the black or brown patina on the surfaces of eight kinds of bronze mirror samples show 4 or 5 broad diffuse peaks which corresponding to almost the same 20 angle, while their matixes does not.These results indicate that those diffuse peaks were produced by the SnO2, microcrystals of 3 ￣5 nm size contained in the black or brown patina.The matrix of unearthed black patina bronze mirror numbered 223, gives strong XRDA diffraction peaks, indicating that there are a large amounts of non-oxidized bronze alloy particles surrounded by SnO2,which shows that the black patinas are not wholly metallic oxides (mainly SnO2),there are also a lot of original alloys of different sizes in grain in the patina.The bright-field image of the black patina sample gives the same result.展开更多
I used to be such a shy boy that I even couldn’t give a speech in public or talk to strangers.But things have changed because of my Chinese teacher.Two years ago,my Chinese teacher asked me to share what I had learne...I used to be such a shy boy that I even couldn’t give a speech in public or talk to strangers.But things have changed because of my Chinese teacher.Two years ago,my Chinese teacher asked me to share what I had learned from the books.At first,I felt so nervous because it was my first time to speak in front of the class.When the teacher found it,she gave me lots of useful suggestions.For example,she encouraged me to keep clam and practice over and over again by talking to myself in the mirror.I followed her advice.To my surprise,the speech was a total success.展开更多
Empathy is one of the most important abilities for social animals.In a world that is largely socially constructed,when encountering altered affective states of others,particularly negative states,individuals often exh...Empathy is one of the most important abilities for social animals.In a world that is largely socially constructed,when encountering altered affective states of others,particularly negative states,individuals often exhibit evolutionarily conserved empathic behaviors,such as mirroring,consolation,and helping[l,2].Appropriate empathic behaviors can foster the consolidation of social relationships.Previous studies have suggested that both male and female rodents show some empathic behaviors when facing affective conspecifics[1].However,the role of sex in different empathic behaviors remains largely unexplored.Therefore,there is a need to probe whether animals show sex-dependent empathic behavior and which neural circuits modulate these distinct behaviors.展开更多
Animated block-buster Ne Zha2 is the first non-Hollywood movie to be part of the.top 10 list and is already the highest-grossing animated movie of all time.If Ne Zha 2 has a bigger international rollout,it will be int...Animated block-buster Ne Zha2 is the first non-Hollywood movie to be part of the.top 10 list and is already the highest-grossing animated movie of all time.If Ne Zha 2 has a bigger international rollout,it will be interesting to see how far its initial momentum can take it.展开更多
In the coldest time every year,when Puma Yumco Lake freezes into a giant blue mirror,villagers nearby at Dowa Village in Nakartse County would herd thousands of sheep across the iced lake surface to find better forage...In the coldest time every year,when Puma Yumco Lake freezes into a giant blue mirror,villagers nearby at Dowa Village in Nakartse County would herd thousands of sheep across the iced lake surface to find better forage on the mid-lake islands.Such herding practices have lasted for a thousand years.Sapphire blue,pure white of both sheep fur and snow on the mountaintops,all colors blend together in a perfect harmony.展开更多
In unconventional high-temperature(high-T_(c))superconductors,the pair density wave state,an exotic superconducting order showing spatially periodic order parameter modulations with the period of several unit cells an...In unconventional high-temperature(high-T_(c))superconductors,the pair density wave state,an exotic superconducting order showing spatially periodic order parameter modulations with the period of several unit cells and translational symmetry breaking,has attracted broad attention.However,the superconducting pair density modulation(PDM)within a single unit cell has never been carefully investigated before.Here,using scanning tunneling microscopy/spectroscopy,we report the observation of PDM in monolayer high-T_(c) iron chalcogenide films epitaxially grown on SrTiO_(3)(001).The superconductivity modulations are characterized by the superconducting gap size and the coherence peak sharpness.Further analysis shows that the local maxima and minima in the superconducting gap modulation are centered at the crystallographic locations of the chalcogen atoms,revealing the breaking of the glide-mirror symmetry of the chalcogen atoms in monolayer high-T_(c) iron chalcogenide films grown on SrTiO_(3)(001).Our findings provide precise microscopic information on superconductivity within the lattice unit cell and may promote the understanding of unconventional high-T_(c) superconductivity.展开更多
The isospin asymmetry and quadrupole deformation value of drip-line nuclei are investigated using the Weizsäcker-Skyrme nuclear mass formula.We observe that for heavy nuclei at the neutron drip line,the Coulomb e...The isospin asymmetry and quadrupole deformation value of drip-line nuclei are investigated using the Weizsäcker-Skyrme nuclear mass formula.We observe that for heavy nuclei at the neutron drip line,the Coulomb energy heightened by an aug-mented charge could not be mitigated completely by symmetry energy because of isospin asymmetry saturation but is resisted complementally by strong nuclear deformation.The positions of saltation for the difference in proton numbers between two neighboring nuclei at the neutron drip line,and the isospin asymmetry of the neutron drip-line nucleus as a function of the neutron number distinctly correspond to the known magic numbers,which can serve as a reference to verify the undeter-mined neutron magic number.Through fitting of the binding energy difference between mirror nuclei(BEDbMN),a set of Coulomb energy coefficients with greater accuracy is obtained.A high-precision description of the BEDbMN is useful for accurately determining the experimentally unknown mass of the nucleus close to the proton drip line if the mass of its mirror nucleus is measured experimentally.展开更多
Polarization control and modulation of optical signals play a crucial role in optical information transmission,with widespread applications in optical communication,sensing,and signal processing.Here,we propose an int...Polarization control and modulation of optical signals play a crucial role in optical information transmission,with widespread applications in optical communication,sensing,and signal processing.Here,we propose an intrinsically chiral nano-kirigami metasurface featuring out-of-plane twisting,which enables switchable spinselective light transmission.At the operating wavelength,it nearly completely blocks the transmission of one type of circularly polarized light while maintaining a transmission exceeding 70%for the other type.Crucially,by merely adjusting the rotation angles or deformation heights of the four arms of the nano-kirigami structures,the metasurface can switch from selective transmission of left-handed circularly polarized light to right-handed circularly polarized light,and vice versa,without the need for dramatic structural geometric chirality changes through mirror operations.Simultaneously,a remarkable circular dichroism of up to 0.74 is achieved,and its sign reverses with the transition of transmission.Electromagnetic multipolar analysis reveals that this switching of chiral response is governed by handedness-dependent excitations of toroidal dipole modes.Additionally,the spin-encoded near-field imaging results demonstrate the potential applications of this switchable spin-selective transmission based on nano-kirigami metasurfaces in digital imaging and chiroptical encryption.展开更多
We present a proof of the Strominger-Yau-Zaslow (SYZ) conjecture by demonstrating that mirror symmetry fundamentally represents an equivalence of computational structures between Calabi-Yau manifolds. Through developm...We present a proof of the Strominger-Yau-Zaslow (SYZ) conjecture by demonstrating that mirror symmetry fundamentally represents an equivalence of computational structures between Calabi-Yau manifolds. Through development of a rigorous quantum complexity operator formalism, we show that mirror pairs must have equivalent complexity spectra and that the SYZ fibration naturally preserves these computational invariants while implementing the required geometric transformations. Our proof proceeds by first establishing a precise mathematical framework connecting quantum complexity with geometric structures, then demonstrating that the special Lagrangian torus fibration preserves computational complexity at both local and global levels, and finally proving that this preservation necessarily implies the geometric correspondences required by the SYZ conjecture. This approach not only resolves the conjecture but reveals deeper insights about the relationship between computation and geometry in string theory. We introduce new complexity-based invariants for studying mirror symmetry and demonstrate how our framework extends naturally to related geometric structures.展开更多
Computer-aided diagnosis(CAD)can detect tuberculosis(TB)cases,providing radiologists with more accurate and efficient diagnostic solutions.Various noise information in TB chest X-ray(CXR)images is a major challenge in...Computer-aided diagnosis(CAD)can detect tuberculosis(TB)cases,providing radiologists with more accurate and efficient diagnostic solutions.Various noise information in TB chest X-ray(CXR)images is a major challenge in this classification task.This study aims to propose a model with high performance in TB CXR image detection named multi-scale input mirror network(MIM-Net)based on CXR image symmetry,which consists of a multi-scale input feature extraction network and mirror loss.The multi-scale image input can enhance feature extraction,while the mirror loss can improve the network performance through self-supervision.We used a publicly available TB CXR image classification dataset to evaluate our proposed method via 5-fold cross-validation,with accuracy,sensitivity,specificity,positive predictive value,negative predictive value,and area under curve(AUC)of 99.67%,100%,99.60%,99.80%,100%,and 0.9999,respectively.Compared to other models,MIM-Net performed best in all metrics.Therefore,the proposed MIM-Net can effectively help the network learn more features and can be used to detect TB in CXR images,thus assisting doctors in diagnosing.展开更多
High-power laser systems have opened new frontiers in scientifi research and have revolutionized various scientifi fields offering unprecedented capabilities for understanding fundamental physics and allowing unique a...High-power laser systems have opened new frontiers in scientifi research and have revolutionized various scientifi fields offering unprecedented capabilities for understanding fundamental physics and allowing unique applications.This paper details the successful commissioning of the 1 PW experimental area at the Extreme Light Infrastructure–Nuclear Physics(ELI-NP)facility in Romania,using both of the available laser arms.The experimental setup featured a short focal parabolic mirror to accelerate protons through the target normal sheath acceleration mechanism.Detailed experiments were conducted using various metallic and diamond-like carbon targets to investigate the dependence of the proton acceleration on different laser parameters.Furthermore,the paper discusses the critical role of the laser temporal profil in optimizing proton acceleration,supported by hydrodynamic simulations that are correlated with experimental outcomes.The finding underscore the potential of the ELI-NP facility to advance research in laser–plasma physics and contribute significantl to high-energy physics applications.The results of this commissioning establish a strong foundation for experiments by future users.展开更多
In deep drilling applications,such as those for geothermal energy,there are many challenges,such as those related to efficient operation of the drilling fluid(mud)pumping system.Legacy drilling rigs often use paired,p...In deep drilling applications,such as those for geothermal energy,there are many challenges,such as those related to efficient operation of the drilling fluid(mud)pumping system.Legacy drilling rigs often use paired,parallel-connected independent-excitation direct-current(DC)motors for mud pumps,that are supplied by a single power converter.This configuration results in electrical power imbalance,thus reducing its efficiency.This paper investigates this power imbalance issue in such legacy DC mud pump drive systems and offers an innovative solution in the form of a closed-loop control system for electrical load balancing.The paper first analyzes the drilling fluid circulation and electrical drive layout to develop an analytical model that can be used for electrical load balancing and related energy efficiency improvements.Based on this analysis,a feedback control system(so-called“current mirror”control system)is designed to balance the electrical load(i.e.,armature currents)of parallel-connected DC machines by adjusting the excitation current of one of the DC machines,thus mitigating the power imbalance of the electrical drive.Theproposed control systemeffectiveness has been validated,first through simulations,followed by experimental testing on a deep drilling rig during commissioning and field tests.The results demonstrate the practical viability of the proposed“current mirror”control system that can effectively and rather quickly equalize the armature currents of both DC machines in a parallel-connected electrical drive,and thus balance both the electrical and mechanical load of individual DC machines under realistic operating conditions of the mud pump electrical drive.展开更多
Adaptive optics(AO)has significantly advanced high-resolution solar observations by mitigating atmospheric turbulence.However,traditional post-focal AO systems suffer from external configurations that introduce excess...Adaptive optics(AO)has significantly advanced high-resolution solar observations by mitigating atmospheric turbulence.However,traditional post-focal AO systems suffer from external configurations that introduce excessive optical surfaces,reduced light throughput,and instrumental polarization.To address these limitations,we propose an embedded solar adaptive optics telescope(ESAOT)that intrinsically incorporates the solar AO(SAO)subsystem within the telescope's optical train,featuring a co-designed correction chain with a single Hartmann-Shack full-wavefront sensor(HS f-WFS)and a deformable secondary mirror(DSM).The HS f-WFS uses temporal-spatial hybrid sampling technique to simultane-ously resolve tip-tilt and high-order aberrations,while the DSM performs real-time compensation through adaptive modal optimization.This unified architecture achieves symmetrical polarization suppression and high system throughput by min-imizing optical surfaces.A 600 mm ESAOT prototype incorporating a 12×12 micro-lens array HS f-WFS and 61-actuator piezoelectric DSM has been developed and successfully conducted on-sky photospheric observations.Validations in-cluding turbulence simulations,optical bench testing,and practical observations at the Lijiang observatory collectively confirm the system's capability to maintain aboutλ/10 wavefront error during active region tracking.This architectural breakthrough of the ESAOT addresses long-standing SAO integration challenges in solar astronomy and provides scala-bility analyses confirming direct applicability to the existing and future large solar observation facilities.展开更多
A new method for directly injecting plasma into the central cell of the Keda Mirror with AXisymmetricity(KMAX)device by using a compact toroid(CT)has been developed.This radial injection approach overcomes the limitat...A new method for directly injecting plasma into the central cell of the Keda Mirror with AXisymmetricity(KMAX)device by using a compact toroid(CT)has been developed.This radial injection approach overcomes the limitations of conventional plasma initiation methods,which typically rely on injecting plasma from one or both ends in a magnetic mirror configuration.The radial injection method aims to produce high-density plasma and facilitate studies of mirror-confined plasma.This paper presents its latest results and provides a detailed description of the injection system design.Our findings confirm the theoretical prediction that the injected plasma must achieve sufficient speed to penetrate the magnetic field and reach the chamber's center.Experimental observations show that,at medium voltage,the plasmoid may linger near the chamber edge,marking the first experimental identification of the conditions required for plasma penetration.展开更多
Two important motifs of The Magic Toyshop,mirrors and puppets,are highly symbolic.They,especially mirrors,play an important role in revealing the theme of Melanie’s growing pains at the cusp of adulthood.From narciss...Two important motifs of The Magic Toyshop,mirrors and puppets,are highly symbolic.They,especially mirrors,play an important role in revealing the theme of Melanie’s growing pains at the cusp of adulthood.From narcissistic proclivities to first“sexual”transgression,from falling victim to Uncle Philip’s manipulation to rebellion against him with her“hero”Finn,the hero⁃ine went through one hardship after another,gradually grew out of her reflection in the mirror and entered the adult world.展开更多
We propose a slope-based decoupling algorithm to simultaneously control the dual deformable mirrors （DMs） in a woofer-tweeter adaptive optics system. This algorithm can directly use the woofer＇s response matrix mea...We propose a slope-based decoupling algorithm to simultaneously control the dual deformable mirrors （DMs） in a woofer-tweeter adaptive optics system. This algorithm can directly use the woofer＇s response matrix measured from a Shack-Hartmann wave-front sensor to construct a slope-based orthogonal basis, and then selectively distribute the large- amplitude low-order aberration to woofer DM and the remaining aberration to tweeter DM through the slope-based orthogonal basis. At the same moment, in order to avoid the two DMs generating opposite compensation, a constraint matrix used to reset tweeter control vector is convenient to be calculated with the slope-based orthogonal basis. Numeral simulation demonstrates that this algorithm has a good performance to control the adaptive optics system with dual DMs simultaneously. Compared with the typical decoupling algorithm, this algorithm can take full use of the compensation ability of woofer DM and release the stroke of tweeter DM to compensate high-order aberration. More importantly, it does not need to measure the accurate shape of tweeter＇s influence function and keeps better performance of restraining the coupling error with the continuous-dynamic aberration.展开更多
基金supported by the National Key R&D Program of China(Grant No.2022YFA1604401)the Shanghai Science and Technology Committee Program(Grant Nos.22560780100 and 23560750200)the National Natural Science Foundation of China(Grant No.61925507)。
文摘Compressing all the energy of a laser pulse into a spatiotemporal focal cube edged by the laser center wavelength will realize the highest intensity of an ultra-intense ultrashort laser,which is called theλ^(3) regime or theλ^(3) laser.Herein,we introduced a rotational hyperbolic mirror—an important rotational conic section mirror with two foci—that is used as a secondary focusing mirror after a rotational parabolic mirror to reduce the focal spot size from several wavelengths to a single wavelength by significantly increasing the focusing angular aperture.Compared with the rotational ellipsoidal mirror,the first focal spot with a high intensity,as well as some unwanted strong-field effects,is avoided.The optimal focusing condition of this method is presented and the enhanced tight focusing for a femtosecond petawatt laser and theλ3 laser is numerically simulated,which can enhance the focused intensities of ultra-intense ultrashort lasers for laser physics.
基金supported by the National Key R&D Program of China (2022YFA1603001,2021YFC2801402)the National Nature Science Foundation of China (12073053)the Science and Technology Plan of Inner Mongolia (2021GG0245).
文摘Research on adaptive deformable mirror technology for voice coil actuators(VCAs)is an important trend in the development of large ground-based telescopes.A voice coil adaptive deformable mirror contains a large number of actuators,and there are problems with structural coupling and large temperature increases in their internal coils.Additionally,parameters of the traditional proportional integral derivative(PID)control cannot be adjusted in real-time to adapt to system changes.These problems can be addressed by introducing fuzzy control methods.A table lookup method is adopted to replace real-time calculations of the regular fuzzy controller during the control process,and a prototype platform has been established to verify the effectiveness and robustness of this process.Experimental tests compare the control performance of traditional and fuzzy proportional integral derivative(Fuzzy-PID)controllers,showing that,in system step response tests,the fuzzy control system reduces rise time by 20.25%,decreases overshoot by 78.24%,and shortens settling time by 67.59%.In disturbance rejection experiments,fuzzy control achieves a 46.09%reduction in the maximum deviation,indicating stronger robustness.The Fuzzy-PID controller,based on table lookup,outperforms the standard controller significantly,showing excellent potential for enhancing the dynamic performance and disturbance rejection capability of the voice coil motor actuator system.
基金supported by the National Key R&D Project of China(No.2022YFE03030000)National Natural Science Foundation of China(Nos.11975269,12275306 and 12075279)+3 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2022452)the Anhui Provincial Natural Science Foundation(No.2208085J40)the CASHIPS Director’s Fund(Nos.YZJJQY202302 and BJPY2023B03)the Comprehensive Research Facility for Fusion Technology Program of China(No.2018-000052-73-01-001228).
文摘First mirror(FM)cleaning,using radio frequency(RF)plasma,has been proposed to recover FM reflectivity in nuclear fusion reactors such as the International Thermonuclear Experimental Reactor(ITER).To investigate the influence of simultaneous cleaning of two mirrors on mirror cleaning efficiency and uniformity,experiments involving single-mirror cleaning and dual-mirror cleaning were conducted using RF capacitively coupled plasma in the laboratory.For the test and simultaneous cleaning of two mirrors,the FM and second mirror(SM),both measuring 110 mm×80 mm,were placed inside the first mirror unit(FMU).They were composed of 16 mirror samples,each with a dimension of 27.5 mm×20 mm.These mirror samples consist of a titanium-zirconium-molybdenum alloy substrate,a 500 nm Mo intermediate layer and a 30 nm Al_(2)O_(3) surface coating as a proxy for Be impurities.The cleaning of a single first mirror(SFM)and the simultaneous cleaning of the FM and SM(DFM and DSM)lasted for 9 h using Ar plasma at a pressure of 1 Pa.The total reflectivity of mirror samples on the DSM did not fully recover and varied with location,with a self-bias of−140 V.With a self-bias of−300 V,the total reflectivity of mirror samples on the SFM and DFM was fully recovered.The energy dispersive spectrometer results demonstrated that the Al_(2)O_(3) coating had been completely removed from these mirror samples.However,the mass loss of each mirror sample on the SFM and DFM before and after cleaning varied depending on its location,with higher mass loss observed for mirror samples located in the corners and lower loss for those in the center.Compared with SM cleaning,the simultaneous cleaning of two mirrors reduced the difference between the highest and lowest mass loss.Furthermore,this mass loss for the mirror samples of the DFM facing the DSM was increased.This indicated that mirror samples cleaned face to face in the FMU simultaneously could influence each other,highlighting the need for special attention in future studies.
文摘A novel method to characterize CMOS process fluctuations in subthreshold current mirrors （SCM） is reported. The proposed model is succinct in methodology and calculation complexity compared with previous statistical models. However,it provides favorable estimations of CMOS process fluctuations on the SCM circuit, which makes it promising for engineering applications. The model statistically abstracts physical parameters, which depend on the IC process, into random variables with certain mean values and standard deviations, while aggregating all the random impacts into a discrete martingale. The correctness of the proposed method is experimentally verified on an SCM circuit implemented in an SMIC 0.18μm CMOS 1P6M mixed signal process with a conversion factor of 100 in an input range from 100pA to lμA. The pro- posed theory successfully predicts - 10% of die-to-die fluctuation measured in the experiment, and also suggests the -lmV of threshold voltage standard deviation over a single die,which meets the process parameters suggested by the design kit from the foundry. The deviations between calculated probabilities and measured data are less than 8%. Meanwhile, pertinent suggestions concerning high fluctuation tolerance subthreshold analog circuit design are also made and discussed.
文摘X-ray diffaction analysis(XRDA)data of the black or brown patina on the surfaces of eight kinds of bronze mirror samples show 4 or 5 broad diffuse peaks which corresponding to almost the same 20 angle, while their matixes does not.These results indicate that those diffuse peaks were produced by the SnO2, microcrystals of 3 ￣5 nm size contained in the black or brown patina.The matrix of unearthed black patina bronze mirror numbered 223, gives strong XRDA diffraction peaks, indicating that there are a large amounts of non-oxidized bronze alloy particles surrounded by SnO2,which shows that the black patinas are not wholly metallic oxides (mainly SnO2),there are also a lot of original alloys of different sizes in grain in the patina.The bright-field image of the black patina sample gives the same result.
文摘I used to be such a shy boy that I even couldn’t give a speech in public or talk to strangers.But things have changed because of my Chinese teacher.Two years ago,my Chinese teacher asked me to share what I had learned from the books.At first,I felt so nervous because it was my first time to speak in front of the class.When the teacher found it,she gave me lots of useful suggestions.For example,she encouraged me to keep clam and practice over and over again by talking to myself in the mirror.I followed her advice.To my surprise,the speech was a total success.
基金supported by grants from the National Natural Science Foundation of China(32125018 and 32071005)the National Key Research and Development Program of China(2021YFA1101701)+5 种基金Zhejiang Provincial Natural Science Foundation of China(LD24H090002)the Nanhu Brain-computer Interface Institute(010904008)the Fundamental Research Funds for the Central Universities(226-2024-00133)the Key R&D Program of Zhejiang(2024SSYS0016)the Non-profit Central Research Institute Fund of the Chinese Academy of Medical Sciences(2023-PT310-01)the MOE Frontiers Science Center for Brain Science&Brain-Machine Integration of Zhejiang University.
文摘Empathy is one of the most important abilities for social animals.In a world that is largely socially constructed,when encountering altered affective states of others,particularly negative states,individuals often exhibit evolutionarily conserved empathic behaviors,such as mirroring,consolation,and helping[l,2].Appropriate empathic behaviors can foster the consolidation of social relationships.Previous studies have suggested that both male and female rodents show some empathic behaviors when facing affective conspecifics[1].However,the role of sex in different empathic behaviors remains largely unexplored.Therefore,there is a need to probe whether animals show sex-dependent empathic behavior and which neural circuits modulate these distinct behaviors.
文摘Animated block-buster Ne Zha2 is the first non-Hollywood movie to be part of the.top 10 list and is already the highest-grossing animated movie of all time.If Ne Zha 2 has a bigger international rollout,it will be interesting to see how far its initial momentum can take it.
文摘In the coldest time every year,when Puma Yumco Lake freezes into a giant blue mirror,villagers nearby at Dowa Village in Nakartse County would herd thousands of sheep across the iced lake surface to find better forage on the mid-lake islands.Such herding practices have lasted for a thousand years.Sapphire blue,pure white of both sheep fur and snow on the mountaintops,all colors blend together in a perfect harmony.
基金supported by the National Natural Science Foundation of China(Grant Nos.12488201 and 12404215)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302403)+1 种基金Guangdong Provincial Quantum Science Strategic Initiative(Grant Nos.GDZX2401001 and GDZX2401009)supported by the U.S.Department of Energy,Basic Energy Sciences(Grant No.DE-FG02-99ER45747)。
文摘In unconventional high-temperature(high-T_(c))superconductors,the pair density wave state,an exotic superconducting order showing spatially periodic order parameter modulations with the period of several unit cells and translational symmetry breaking,has attracted broad attention.However,the superconducting pair density modulation(PDM)within a single unit cell has never been carefully investigated before.Here,using scanning tunneling microscopy/spectroscopy,we report the observation of PDM in monolayer high-T_(c) iron chalcogenide films epitaxially grown on SrTiO_(3)(001).The superconductivity modulations are characterized by the superconducting gap size and the coherence peak sharpness.Further analysis shows that the local maxima and minima in the superconducting gap modulation are centered at the crystallographic locations of the chalcogen atoms,revealing the breaking of the glide-mirror symmetry of the chalcogen atoms in monolayer high-T_(c) iron chalcogenide films grown on SrTiO_(3)(001).Our findings provide precise microscopic information on superconductivity within the lattice unit cell and may promote the understanding of unconventional high-T_(c) superconductivity.
基金supported by the Ministry of Science and Technology of China(No.2022YFE0103400)Natural Science Foundation of Guangxi Province(No.2021GXNSFAA196052)National Natural Science Foundation of China(No.11965004).
文摘The isospin asymmetry and quadrupole deformation value of drip-line nuclei are investigated using the Weizsäcker-Skyrme nuclear mass formula.We observe that for heavy nuclei at the neutron drip line,the Coulomb energy heightened by an aug-mented charge could not be mitigated completely by symmetry energy because of isospin asymmetry saturation but is resisted complementally by strong nuclear deformation.The positions of saltation for the difference in proton numbers between two neighboring nuclei at the neutron drip line,and the isospin asymmetry of the neutron drip-line nucleus as a function of the neutron number distinctly correspond to the known magic numbers,which can serve as a reference to verify the undeter-mined neutron magic number.Through fitting of the binding energy difference between mirror nuclei(BEDbMN),a set of Coulomb energy coefficients with greater accuracy is obtained.A high-precision description of the BEDbMN is useful for accurately determining the experimentally unknown mass of the nucleus close to the proton drip line if the mass of its mirror nucleus is measured experimentally.
基金supported by the National Natural Science Foundation of China(Grant Nos.62205282 and 12074331)the Hebei Natural Science Foundation(Grant No.A2022203035)the Science and Technology Project of Hebei Education Department(Grant No.BJK2023009)。
文摘Polarization control and modulation of optical signals play a crucial role in optical information transmission,with widespread applications in optical communication,sensing,and signal processing.Here,we propose an intrinsically chiral nano-kirigami metasurface featuring out-of-plane twisting,which enables switchable spinselective light transmission.At the operating wavelength,it nearly completely blocks the transmission of one type of circularly polarized light while maintaining a transmission exceeding 70%for the other type.Crucially,by merely adjusting the rotation angles or deformation heights of the four arms of the nano-kirigami structures,the metasurface can switch from selective transmission of left-handed circularly polarized light to right-handed circularly polarized light,and vice versa,without the need for dramatic structural geometric chirality changes through mirror operations.Simultaneously,a remarkable circular dichroism of up to 0.74 is achieved,and its sign reverses with the transition of transmission.Electromagnetic multipolar analysis reveals that this switching of chiral response is governed by handedness-dependent excitations of toroidal dipole modes.Additionally,the spin-encoded near-field imaging results demonstrate the potential applications of this switchable spin-selective transmission based on nano-kirigami metasurfaces in digital imaging and chiroptical encryption.
文摘We present a proof of the Strominger-Yau-Zaslow (SYZ) conjecture by demonstrating that mirror symmetry fundamentally represents an equivalence of computational structures between Calabi-Yau manifolds. Through development of a rigorous quantum complexity operator formalism, we show that mirror pairs must have equivalent complexity spectra and that the SYZ fibration naturally preserves these computational invariants while implementing the required geometric transformations. Our proof proceeds by first establishing a precise mathematical framework connecting quantum complexity with geometric structures, then demonstrating that the special Lagrangian torus fibration preserves computational complexity at both local and global levels, and finally proving that this preservation necessarily implies the geometric correspondences required by the SYZ conjecture. This approach not only resolves the conjecture but reveals deeper insights about the relationship between computation and geometry in string theory. We introduce new complexity-based invariants for studying mirror symmetry and demonstrate how our framework extends naturally to related geometric structures.
基金supported by the Joint Fund of the Ministry of Education for Equipment Pre-research(No.8091B0203)National Key Research and Development Program of China(No.2020YFC2008700)。
文摘Computer-aided diagnosis(CAD)can detect tuberculosis(TB)cases,providing radiologists with more accurate and efficient diagnostic solutions.Various noise information in TB chest X-ray(CXR)images is a major challenge in this classification task.This study aims to propose a model with high performance in TB CXR image detection named multi-scale input mirror network(MIM-Net)based on CXR image symmetry,which consists of a multi-scale input feature extraction network and mirror loss.The multi-scale image input can enhance feature extraction,while the mirror loss can improve the network performance through self-supervision.We used a publicly available TB CXR image classification dataset to evaluate our proposed method via 5-fold cross-validation,with accuracy,sensitivity,specificity,positive predictive value,negative predictive value,and area under curve(AUC)of 99.67%,100%,99.60%,99.80%,100%,and 0.9999,respectively.Compared to other models,MIM-Net performed best in all metrics.Therefore,the proposed MIM-Net can effectively help the network learn more features and can be used to detect TB in CXR images,thus assisting doctors in diagnosing.
基金supported by the Extreme Light Infrastructure–Nuclear Physics(ELI-NP)PhaseⅡa project co-finance by the Romanian Government and the European Union through the European Regional Development Fund,by the Romanian Ministry of Education and Research CNCS-UEFISCDI(Project No.PN-ⅡIP4-IDPCCF-2016-0164)+1 种基金Nucleu Projects(Grant No.PN 23210105 and 19060105)supports ELI-NP through IOSIN funds as a Facility of National Interest。
文摘High-power laser systems have opened new frontiers in scientifi research and have revolutionized various scientifi fields offering unprecedented capabilities for understanding fundamental physics and allowing unique applications.This paper details the successful commissioning of the 1 PW experimental area at the Extreme Light Infrastructure–Nuclear Physics(ELI-NP)facility in Romania,using both of the available laser arms.The experimental setup featured a short focal parabolic mirror to accelerate protons through the target normal sheath acceleration mechanism.Detailed experiments were conducted using various metallic and diamond-like carbon targets to investigate the dependence of the proton acceleration on different laser parameters.Furthermore,the paper discusses the critical role of the laser temporal profil in optimizing proton acceleration,supported by hydrodynamic simulations that are correlated with experimental outcomes.The finding underscore the potential of the ELI-NP facility to advance research in laser–plasma physics and contribute significantl to high-energy physics applications.The results of this commissioning establish a strong foundation for experiments by future users.
文摘In deep drilling applications,such as those for geothermal energy,there are many challenges,such as those related to efficient operation of the drilling fluid(mud)pumping system.Legacy drilling rigs often use paired,parallel-connected independent-excitation direct-current(DC)motors for mud pumps,that are supplied by a single power converter.This configuration results in electrical power imbalance,thus reducing its efficiency.This paper investigates this power imbalance issue in such legacy DC mud pump drive systems and offers an innovative solution in the form of a closed-loop control system for electrical load balancing.The paper first analyzes the drilling fluid circulation and electrical drive layout to develop an analytical model that can be used for electrical load balancing and related energy efficiency improvements.Based on this analysis,a feedback control system(so-called“current mirror”control system)is designed to balance the electrical load(i.e.,armature currents)of parallel-connected DC machines by adjusting the excitation current of one of the DC machines,thus mitigating the power imbalance of the electrical drive.Theproposed control systemeffectiveness has been validated,first through simulations,followed by experimental testing on a deep drilling rig during commissioning and field tests.The results demonstrate the practical viability of the proposed“current mirror”control system that can effectively and rather quickly equalize the armature currents of both DC machines in a parallel-connected electrical drive,and thus balance both the electrical and mechanical load of individual DC machines under realistic operating conditions of the mud pump electrical drive.
基金support from the National Science Foundation of China(NSFC)(Grants No.12293031 and No.61905252)the National Science Foundation for Distinguished Young Scholars(Grant No.12022308)the National Key R&D Program of China(Grants No.2021YFC2202200 and No.2021YFC2202204).
文摘Adaptive optics(AO)has significantly advanced high-resolution solar observations by mitigating atmospheric turbulence.However,traditional post-focal AO systems suffer from external configurations that introduce excessive optical surfaces,reduced light throughput,and instrumental polarization.To address these limitations,we propose an embedded solar adaptive optics telescope(ESAOT)that intrinsically incorporates the solar AO(SAO)subsystem within the telescope's optical train,featuring a co-designed correction chain with a single Hartmann-Shack full-wavefront sensor(HS f-WFS)and a deformable secondary mirror(DSM).The HS f-WFS uses temporal-spatial hybrid sampling technique to simultane-ously resolve tip-tilt and high-order aberrations,while the DSM performs real-time compensation through adaptive modal optimization.This unified architecture achieves symmetrical polarization suppression and high system throughput by min-imizing optical surfaces.A 600 mm ESAOT prototype incorporating a 12×12 micro-lens array HS f-WFS and 61-actuator piezoelectric DSM has been developed and successfully conducted on-sky photospheric observations.Validations in-cluding turbulence simulations,optical bench testing,and practical observations at the Lijiang observatory collectively confirm the system's capability to maintain aboutλ/10 wavefront error during active region tracking.This architectural breakthrough of the ESAOT addresses long-standing SAO integration challenges in solar astronomy and provides scala-bility analyses confirming direct applicability to the existing and future large solar observation facilities.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0790303)National Natural Science Foundation of China(No.12175226)。
文摘A new method for directly injecting plasma into the central cell of the Keda Mirror with AXisymmetricity(KMAX)device by using a compact toroid(CT)has been developed.This radial injection approach overcomes the limitations of conventional plasma initiation methods,which typically rely on injecting plasma from one or both ends in a magnetic mirror configuration.The radial injection method aims to produce high-density plasma and facilitate studies of mirror-confined plasma.This paper presents its latest results and provides a detailed description of the injection system design.Our findings confirm the theoretical prediction that the injected plasma must achieve sufficient speed to penetrate the magnetic field and reach the chamber's center.Experimental observations show that,at medium voltage,the plasmoid may linger near the chamber edge,marking the first experimental identification of the conditions required for plasma penetration.
文摘Two important motifs of The Magic Toyshop,mirrors and puppets,are highly symbolic.They,especially mirrors,play an important role in revealing the theme of Melanie’s growing pains at the cusp of adulthood.From narcissistic proclivities to first“sexual”transgression,from falling victim to Uncle Philip’s manipulation to rebellion against him with her“hero”Finn,the hero⁃ine went through one hardship after another,gradually grew out of her reflection in the mirror and entered the adult world.
基金Project supported by the Key Scientific Equipment Development Project of China(Grant No.ZDYZ2013-2)the National High-Tech R&D Program of China(Grant Nos.G128201-G158201 and G128603-G158603)+2 种基金the Innovation Fund of Chinese Academy of Science(Grant No.CXJJ-16M208)the Youth Innovation Promotion Association of the Chinese Academy of Sciencesthe Outstanding Young Scientists,Chinese Academy of Sciences
文摘We propose a slope-based decoupling algorithm to simultaneously control the dual deformable mirrors （DMs） in a woofer-tweeter adaptive optics system. This algorithm can directly use the woofer＇s response matrix measured from a Shack-Hartmann wave-front sensor to construct a slope-based orthogonal basis, and then selectively distribute the large- amplitude low-order aberration to woofer DM and the remaining aberration to tweeter DM through the slope-based orthogonal basis. At the same moment, in order to avoid the two DMs generating opposite compensation, a constraint matrix used to reset tweeter control vector is convenient to be calculated with the slope-based orthogonal basis. Numeral simulation demonstrates that this algorithm has a good performance to control the adaptive optics system with dual DMs simultaneously. Compared with the typical decoupling algorithm, this algorithm can take full use of the compensation ability of woofer DM and release the stroke of tweeter DM to compensate high-order aberration. More importantly, it does not need to measure the accurate shape of tweeter＇s influence function and keeps better performance of restraining the coupling error with the continuous-dynamic aberration.
