Digital watermarking technology plays an essential role in the work of anti-counterfeiting and traceability.However,image watermarking algorithms are weak against hybrid attacks,especially geometric attacks,such as cr...Digital watermarking technology plays an essential role in the work of anti-counterfeiting and traceability.However,image watermarking algorithms are weak against hybrid attacks,especially geometric attacks,such as cropping attacks,rotation attacks,etc.We propose a robust blind image watermarking algorithm that combines stable interest points and deep learning networks to improve the robustness of the watermarking algorithm further.First,to extract more sparse and stable interest points,we use the Superpoint algorithm for generation and design two steps to perform the screening procedure.We first keep the points with the highest possibility in a given region to ensure the sparsity of the points and then filter the robust interest points by hybrid attacks to ensure high stability.The message is embedded in sub-blocks centered on stable interest points using a deep learning-based framework.Different kinds of attacks and simulated noise are added to the adversarial training to guarantee the robustness of embedded blocks.We use the ConvNext network for watermark extraction and determine the division threshold based on the decoded values of the unembedded sub-blocks.Through extensive experimental results,we demonstrate that our proposed algorithm can improve the accuracy of the network in extracting information while ensuring high invisibility between the embedded image and the original cover image.Comparison with previous SOTA work reveals that our algorithm can achieve better visual and numerical results on hybrid and geometric attacks.展开更多
Photonic signal processing offers a versatile and promising toolkit for contemporary scenarios ranging from digital optical communication to analog microwave operation.Compared to its electronic counterpart,it elimina...Photonic signal processing offers a versatile and promising toolkit for contemporary scenarios ranging from digital optical communication to analog microwave operation.Compared to its electronic counterpart,it eliminates inherent bandwidth limitations and meanwhile exhibits the potential to provide unparalleled scalability and flexibility,particularly through integrated photonics.However,by far the on-chip solutions for optical signal processing are often tailored to specific tasks,which lacks versatility across diverse applications.Here,we propose a streamlined chip-level signal processing architecture that integrates different active and passive building blocks in silicon-on-insulator(SOI)platform with a compact and efficient manner.Comprehensive and in-depth analyses for the architecture are conducted at levels of device,system,and application.Accompanied by appropriate configuring schemes,the photonic circuitry supports loading and processing both analog and digital signals simultaneously.Three distinct tasks are facilitated with one single chip across several mainstream fields,spanning optical computing,microwave photonics,and optical communications.Notably,it has demonstrated competitive performance in functions like image processing,spectrum filtering,and electro-optical bandwidth equalization.Boasting high universality and a compact form factor,the proposed architecture is poised to be instrumental for next-generation functional fusion systems.展开更多
Background: Alzheimer’s disease (AD) is an increasingly prevalent neurodegenerative disease characterized by protein aggregation in the form of amyloid plaques containing beta-amyloid peptides and neurofibrillary tan...Background: Alzheimer’s disease (AD) is an increasingly prevalent neurodegenerative disease characterized by protein aggregation in the form of amyloid plaques containing beta-amyloid peptides and neurofibrillary tangles containing hyperphosphorylated tau protein. The central molecular events underlying AD pathogenesis remain controversial and poorly defined. Drosophila melanogaster has emerged as an important genetic resource for studying the pathology of AD. Many AD models have been created using Drosophila, taking advantage of its short generation times, sophisticated genetic tools, and abundance of homologs to human genes. Purpose: This review summarizes different models for studying AD in Drosophila melanogaster, including the full-length APP, C99, Aβ42 and Tau models, explaining how the models were built and what we have learned from them. Conclusion: Four main AD Drosophila models are introduced in this review, which can serve as a future method to investigate genes and drugs that can modify symptoms.展开更多
Alzheimer’s disease (AD) is one of the most significant neurodegenerative disorders in terms of both severity and cost. Despite being defined over a century ago, there is currently no cure to this disease that affect...Alzheimer’s disease (AD) is one of the most significant neurodegenerative disorders in terms of both severity and cost. Despite being defined over a century ago, there is currently no cure to this disease that affects an increasing elderly population. The amyloid precursor protein (APP) has been shown to play an important role in AD progression. The amyloid β peptide (Aβ), which accumulates in senile plaques, a central etiological AD factor, is a proteolytic product from APP by the enzymatic action of β- and γ-secretases. In this review, we summarize the current knowledge of the processing and physiological functions of APP, and the involvement of APP and Aβ in AD.展开更多
In this study,the effect of ash removal on Shenfu bituminous coal was investigated.The coal was pretreated by hydrofluoric acid(HF)pickling,and the raw/pretreated coal chars were prepared at 900°C in a fixed bed ...In this study,the effect of ash removal on Shenfu bituminous coal was investigated.The coal was pretreated by hydrofluoric acid(HF)pickling,and the raw/pretreated coal chars were prepared at 900°C in a fixed bed reactor.The structure of coal and char were detected by Fourier transform infrared(FTIR)and Raman spectroscopy.The reactivity was tested in a thermogravimetric analyzer,including coal pyrolysis and char gasification.The reaction kinetics was analyzed through the Coats–Redfern method,master plots,the model-free and model-fitting method.The results show that the HF pickling can remove silicon from coal efficiently,and the macromolecular framework of coal is quite stable according to FTIR.The Raman parameters imply some carbonaceous structure on coal surface changed.For slow pyrolysis of coal,the effect of heating rate is considered.The changes of pyrolysis characteristics and kinetics are insignificant.For char gasification,the reactivity under isothermal and non-isothermal condition are discussed with an emphasis in different residence time of devolatilization process.In kinetic control region(low temperature),the activation energy(Ea)is very close(about 240 kJ/mol)for all chars.With the temperature increases,the reactivity of raw coal char is more easily suffered by diffusion.The random pore model is more suitable for the ash-free coal char,and the char with long residence time has a larger value of structural parameterψand smaller value of pre-exponential factor A.The Ea calculated by model-fitting and model-free method were in good agreement.展开更多
In this study,the Powder River Basin(PRB)coal fast pyrolysis was conducted at 700°C in the atmosphere of syngas produced by CH4-CO2 reforming in two different patterns,including the double reactors pattern(the fi...In this study,the Powder River Basin(PRB)coal fast pyrolysis was conducted at 700°C in the atmosphere of syngas produced by CH4-CO2 reforming in two different patterns,including the double reactors pattern(the first reactor is for syngas production and the second is for coal pyrolysis)and double layers pattern(catalyst was at upper layer and coal was at lower layer).Besides,pure gases atmosphere including N2,H2,CO,H2-CO were also tested to investigate the mechanism of the coal pyrolysis under different atmospheres.The pyrolysis products including gas,liquid and char were characterized,the result showed that,compared with the inert atmosphere,the tar yield is improved with the reducing atmospheres,as well as the tar quality.The hydrogen partial pressure is the key point for that improvement.In the atmosphere of H2,the tar yield was increased by 31.3%and the contained BTX(benzene,toluene and xylene)and naphthalene were increased by 27.1%and 133.4%.The double reactors pattern also performed outstandingly,with 25.4%increment of tar yield and 25.0%and 79.4%for the BTX and naphthalene.The double layers pattern is not effective enough due to the low temperature(700°C)in which the Ni-based catalyst was not fully activated.展开更多
Sharing the hardware platform between diverse information systems to establish full cooperation among different functionalities has attracted substantial attention.However,broadband multifunctional integrated systems ...Sharing the hardware platform between diverse information systems to establish full cooperation among different functionalities has attracted substantial attention.However,broadband multifunctional integrated systems with large operating frequency ranges are challenging due to the bandwidth and computing speed restrictions of electronic circuitry.Here,we report an analog parallel processor(APP)based on the silicon photonic platform that directly discretizes and parallelizes the broadband signal in the analog domain.The APP first discretizes the signal with the optical frequency comb and then adopts optical dynamic phase interference to reassign the analog signal into 2N parallel sequences.Via photonic analog parallelism,data rate and data volume in each sequence are simultaneously compressed,which mitigates the requirement on each parallel computing core.Moreover,the fusion of the outputs from each computing core is equivalent to directly processing broadband signals.In the proof-of-concept experiment,two-channel analog parallel processing of broadband radar signals and high-speed communication signals is implemented on the single photonic integrated circuit.The bandwidth of broadband radar signal is 6 GHz and the range resolution of 2.69 cm is achieved.The wireless communication rate of 8 Gbit/s is also validated.Breaking the bandwidth and speed limitations of the single-computing core along with further exploring the multichannel potential of this architecture,we anticipate that the proposed APP will accelerate the development of powerful optoelectronic processors as critical support for applications such as satellite networks and intelligent driving.展开更多
The catalytic coal gasification technology has been widely researched and developed under the background of“Carbon peaking and carbon neutrality goals”.Currently,most of catalytic gasification experiments on coal ch...The catalytic coal gasification technology has been widely researched and developed under the background of“Carbon peaking and carbon neutrality goals”.Currently,most of catalytic gasification experiments on coal char particles are analyzed by thermogravimetric analyzer(TGA).However,the gasification agent will be subject to diffusion resistance during the reaction because of the sample stacking,making the inherent reaction kinetics unclear.In this study,we investigated the catalytic gasification behavior of single-particle coal char using high temperature stage microscope(HTSM).With the diffusion resistance ruled out,the reaction conditions when using a HTSM are more similar to those inside a real industrial gasifier.Numerical models of the gasification reaction of single-particle coal char were further developed using the kinetic parameters obtained under HTSM.Three models were investigated,including regular spherical structured,irregular spherical structured and porous spherical structured models,representing different morphologies of coal char particles in the gasifier.The gasification characteristics of coal char particles under different K_(2)CO_(3)catalyst loadings and gasification temperatures were also studied.Compared with the activation energies data of coal char particles without catalyst,the activation energies of coal char particles loaded with 2.2%,4.4%,6.6%,and 10.0%catalysts were reduced by 110 kJ/mol,116 kJ/mol,121 kJ/mol,and 126 kJ/mol,respectively.The reaction surface area affects the temperature distribution.The temperature near the irregular spherical particle is about 20 K higher than the temperature near the regular spherical particle.展开更多
Harnessing optical supermode interaction to construct artificial photonic molecules has uncovered a series of fundamental optical phenomena analogous to atomic physics.Previously,the distinct energy levels and interac...Harnessing optical supermode interaction to construct artificial photonic molecules has uncovered a series of fundamental optical phenomena analogous to atomic physics.Previously,the distinct energy levels and interactions in such two-level systems were provided by coupled microresonators.The reconfigurability is limited,as they often require delicate external field stimuli or mechanically altering the geometric factors.These highly specific approaches also limit potential applications.Here,we propose a versatile on-chip photonic molecule in a multimode microring,utilizing a flexible regulation methodology to dynamically control the existence and interaction strength of spatial modes.The transition between single/multi-mode states enables the“switched-off/on”functionality of the photonic molecule,supporting wider generalized applications scenarios.In particular,“switched-on”state shows flexible and multidimensional mode splitting control in aspects of both coupling strength and phase difference,equivalent to the a.c.and d.c.Stark effect.“Switched-off”state allows for perfect low-loss single-mode transition(Qi~10 million)under an ultra-compact bend size(FSR~115 GHz)in a foundry-based silicon microring.It breaks the stereotyped image of the FSR-Q factor trade-off,enabling ultra-wideband and high-resolution millimeter-wave photonic operations.Our demonstration provides a flexible and portable solution for the integrated photonic molecule system,extending its research scope from fundamental physics to real-world applications such as nonlinear optical signal processing and sixth-generation wireless communication.展开更多
Self-injection locking has emerged as a crucial technique for coherent optical sources,spanning from narrow linewidth lasers to the generation of localized microcombs.This technique involves key components,namely a la...Self-injection locking has emerged as a crucial technique for coherent optical sources,spanning from narrow linewidth lasers to the generation of localized microcombs.This technique involves key components,namely a laser diode and a high-quality cavity that induces narrow-band reflection back into the laser diode.However,in prior studies,the reflection mainly relied on the random intracavity Rayleigh backscattering,rendering it unpredictable and unsuitable for large-scale production and wide-band operation.In this work,we present a simple approach to achieve reliable intracavity reflection for self-injection locking to address this challenge by introducing a Sagnac loop into the cavity.This method guarantees robust reflection for every resonance within a wide operational band without compromising the quality factor or adding complexity to the fabrication process.As a proof of concept,we showcase the robust generation of narrow linewidth lasers and localized microcombs locked to different resonances within a normal-dispersion microcavity.Furthermore,the existence and generation of localized patterns in a normal-dispersion cavity with broadband forward–backward field coupling is first proved,as far as we know,both in simulation and in experiment.Our research offers a transformative approach to self-injection locking and holds great potential for large-scale production.展开更多
Self-injection locking has emerged as a crucial technique for coherent optical sources,spanning from narrow linewidth lasers to the generation of localized microcombs.This technique involves key components,namely a la...Self-injection locking has emerged as a crucial technique for coherent optical sources,spanning from narrow linewidth lasers to the generation of localized microcombs.This technique involves key components,namely a laser diode and a high-quality cavity that induces narrow-band reflection back into the laser diode.However,in prior studies,the reflection mainly relied on the random intracavity Rayleigh backscattering,rendering it unpredictable and unsuitable for large-scale production and wide-band operation.In this work,we present a simple approach to achieve reliable intracavity reflection for self-injection locking to address this challenge by introducing a Sagnac loop into the cavity.This method guarantees robust reflection for every resonance within a wide operational band without compromising the quality factor or adding complexity to the fabrication process.As a proof of concept,we showcase the robust generation of narrow linewidth lasers and localized microcombs locked to different resonances within a normal-dispersion microcavity.Furthermore,the existence and generation of localized patterns in a normal-dispersion cavity with broadband forward–backward field coupling is first proved,as far as we know,both in simulation and in experiment.Our research offers a transformative approach to self-injection locking and holds great potential for large-scale production.展开更多
Optical implementations of neural networks(ONNs)herald the next-generation high-speed and energy-efficient deep learning computing by harnessing the technical advantages of large bandwidth and high parallelism of opti...Optical implementations of neural networks(ONNs)herald the next-generation high-speed and energy-efficient deep learning computing by harnessing the technical advantages of large bandwidth and high parallelism of optics.However,due to the problems of the incomplete numerical domain,limited hardware scale,or inadequate numerical accuracy,the majority of existing ONNs were studied for basic classification tasks.Given that regression is a fundamental form of deep learning and accounts for a large part of current artificial intelligence applications,it is necessary to master deep learning regression for further development and deployment of ONNs.Here,we demonstrate a silicon-based optical coherent dot-product chip(OCDC)capable of completing deep learning regression tasks.The OCDC adopts optical fields to carry out operations in the complete real-value domain instead of in only the positive domain.Via reusing,a single chip conducts matrix multiplications and convolutions in neural networks of any complexity.Also,hardware deviations are compensated via in-situ backpropagation control provided the simplicity of chip architecture.Therefore,the OCDC meets the requirements for sophisticated regression tasks and we successfully demonstrate a representative neural network,the AUTOMAP(a cutting-edge neural network model for image reconstruction).The quality of reconstructed images by the OCDC and a 32-bit digital computer is comparable.To the best of our knowledge,there is no precedent of performing such state-of-the-art regression tasks on ONN chips.It is anticipated that the OCDC can promote the novel accomplishment of ONNs in modern AI applications including autonomous driving,natural language processing,and scientific study.展开更多
Integrated microwave photonic filters(IMPFs)are capable of offering unparalleled performances in terms of superb spectral fineness,broadband,and more importantly,the reconfigurability,which encounter the trend of the ...Integrated microwave photonic filters(IMPFs)are capable of offering unparalleled performances in terms of superb spectral fineness,broadband,and more importantly,the reconfigurability,which encounter the trend of the next-generation wireless communication.However,to achieve high reconfigurability,previous works should adopt complicated system structures and modulation formats,which put great pressure on power consumption and controlment,and,therefore,impede the massive deployment of IMPF.Here,we propose a streamlined architecture for a wideband and highly reconfigurable IMPF on the silicon photonics platform.For various practical filter responses,to avoid complex auxiliary devices and bias drift problems,a phase-modulated flexible sideband cancellation method is employed based on the intensity-consistent single-stage-adjustable cascadedmicroring(ICSSA-CM).The IMPF exhibits an operation band extending to millimeter-wave(≥30 GHz),and other extraordinary performances including high spectral resolution of 220 MHz and large rejection ratio of 60 d B are obtained.Moreover,Gb/s-level RF wireless communications are demonstrated for the first time towards real-world scenarios.The proposed IMPF provides broadband flexible spectrum control capabilities,showing great potential in the next-generation wireless communication.展开更多
The integrated microwave photonic filter(MPF),as a compelling candidate for next-generation radio-frequency(RF)applications,has been widely investigated for decades.However,most integrated MPFs reported thus far have ...The integrated microwave photonic filter(MPF),as a compelling candidate for next-generation radio-frequency(RF)applications,has been widely investigated for decades.However,most integrated MPFs reported thus far have merely incorporated passive photonic components onto a chip-scale platform,while all necessary active devices are still bulk and discrete.Though few attempts to higher photonic integration of MPFs have been executed,the achieved filtering performances are fairly limited,which impedes the pathway to practical deployments.Here,we demonstrate,for the first time to our knowledge,an all-integrated MPF combined with high filtering performances,through hybrid integration of an In P chip-based laser and a monolithic silicon photonic circuit consisting of a dual-drive Mach–Zehnder modulator,a high-Q ring resonator,and a photodetector.This integrated MPF exhibits a high spectral resolution as narrow as 360 MHz,a wide-frequency tunable range covering the S-band to K-band(3 to 25 GHz),and a large rejection ratio of>40 d B.Moreover,the filtering response can be agilely switched between the bandpass and band-stop function with a transient respond time(48μs).Compared with previous MPFs in a similar integration level,the obtained spectral resolution in this work is dramatically improved by nearly one order of magnitude,while the valid frequency tunable range is broadened more than twice,which can satisfy the essential filtering requirements in actual RF systems.As a paradigm demonstration oriented to real-world scenarios,high-resolution RF filtering of realistic microwave signals aiming for interference rejection and channel selection is performed.Our work points out a feasible route to a miniaturized,high-performance,and cost-effective MPF leveraging hybrid integration approach,thus enabling a range of RF applications from wireless communication to radar toward the higher-frequency region,more compact size,and lower power consumption.展开更多
Microwave photonic receivers are a promising candidate in breaking the bandwidth limitation of traditional radio-frequency(RF)receivers.To further balance the performance superiority with the requirements regarding si...Microwave photonic receivers are a promising candidate in breaking the bandwidth limitation of traditional radio-frequency(RF)receivers.To further balance the performance superiority with the requirements regarding size,weight,and power consumption(SWa P),the implementation of integrated microwave photonic microsystems has been considered an upgrade path.However,up to now,to the best of our knowledge,chip-scale fully integrated microwave photonic receivers have not been reported due to the limitation of material platforms.In this paper,we report a fully integrated hybrid microwave photonic receiver(FIH-MWPR)obtained by comprising the indium phosphide(In P)laser chip and the monolithic silicon-on-insulator(SOI)photonic circuit into the same substrate based on the low-coupling-loss micro-optics method.Benefiting from the integration of all optoelectronic components,the packaged FIH-MWPR exhibits a compact volume of 6 cmand low power consumption of 1.2 W.The FIH-MWPR supports a wide operation bandwidth from 2 to 18 GHz.Furthermore,its RF-link performance to down-convert the RF signals to the intermediate frequency is experimentally characterized by measuring the link gain,the noise figure,and the spurious-free dynamic range metrics across the whole operation frequency band.Moreover,we have utilized it as a de-chirp receiver to process the broadband linear frequencymodulated(LFM)radar echo signals at different frequency bands(S-,C-,X-,and Ku-bands)and successfully demonstrated its high-resolution-ranging capability.To the best of our knowledge,this is the first realization of a chip-scale broadband fully integrated microwave photonic receiver,which is expected to be an important step in demonstrating the feasibility of all-integrated microwave photonic microsystems oriented to miniaturized application scenarios.展开更多
Microcombs are revolutionizing optoelectronics by providing parallel, mutually coherent wavelengthchannels for time-frequency metrology and information processing. To implement this essential function inintegrated pho...Microcombs are revolutionizing optoelectronics by providing parallel, mutually coherent wavelengthchannels for time-frequency metrology and information processing. To implement this essential function inintegrated photonic systems, it is desirable to drive microcombs directly with an on-chip laser in a simpleand flexible way. However, two major difficulties have prevented this goal: (1) generating mode-lockedcomb states usually requires a significant amount of pump power and (2) the requirement to align laser andresonator frequency significantly complicates operation and limits the tunability of the comb lines. Here, weaddress these problems by using microresonators on an AlGaAs on-insulator platform to generate dark-pulsemicrocombs. This highly nonlinear platform dramatically relaxes fabrication requirements and leads to arecord-low pump power of <1 mW for coherent comb generation. Dark-pulse microcombs facilitated bythermally controlled avoided mode crossings are accessed by direct distributed feedback laser pumping.Without any feedback or control circuitries, the comb shows good coherence and stability. With around150 mW on-chip power, this approach also leads to an unprecedentedly wide tuning range of over one freespectral range (97.5 GHz). Our work provides a route to realize power-efficient, simple, and reconfigurablemicrocombs that can be seamlessly integrated with a wide range of photonic systems.展开更多
A hybrid integrated 16-channel silicon transmitter based on co-designed photonic integrated circuits(PICs) and electrical chiplets is demonstrated. The driver in the 65 nm CMOS process employs the combination of a dis...A hybrid integrated 16-channel silicon transmitter based on co-designed photonic integrated circuits(PICs) and electrical chiplets is demonstrated. The driver in the 65 nm CMOS process employs the combination of a distributed architecture, two-tap feedforward equalization(FFE), and a push–pull output stage, exhibiting an estimated differential output swing of 4.0V_(pp). The rms jitter of 2.0 ps is achieved at 50 Gb/s under nonreturnto-zero on–off keying(NRZ-OOK) modulation. The PICs are fabricated on a standard silicon-on-insulator platform and consist of 16 parallel silicon dual-drive Mach–Zehnder modulators on a single chip. The chip-on-board co-packaged Si transmitter is constituted by the multichannel chiplets without any off-chip bias control, which significantly simplifies the system complexity. Experimentally, the open and clear optical eye diagrams of selected channels up to 50 Gb/s OOK with extinction ratios exceeding 3 dB are obtained without any digital signal processing. The power consumption of the Si transmitter with a high integration density featuring a throughput up to 800 Gb/s is only 5.35 p J/bit, indicating a great potential for massively parallel terabit-scale optical interconnects for future hyperscale data centers and high-performance computing systems.展开更多
Integrated waveguides with slot structures have attracted increasing attention due to their advantages of tight mode confinement and strong light-matter interaction.Although extensively studied,the issue of mode misma...Integrated waveguides with slot structures have attracted increasing attention due to their advantages of tight mode confinement and strong light-matter interaction.Although extensively studied,the issue of mode mismatch with other strip waveguide-based optical devices is a huge challenge that prevents integrated waveguides from being widely utilized in large-scale photonic-based circuits.In this paper,we demonstrate an ultra-compact low-loss slot-strip converter with polarization insensitivity based on the multimode interference(MMI)effect.Sleek sinusoidal profiles are adopted to allow for smooth connection between the slot and strip waveguide,resulting reflection reduction.By manipulating the MMI effect with structure optimization,the self-imaging positions of the TE0 and TM0 modes are aligned with minimized footprint,leading to low-loss transmission for both polarizations.The measurement results show that high coupling efficiencies of−0.40 and−0.64 dB are achieved for TE_(0) and TM_(0) polarizations,respectively.The device has dimensions as small as 1.1μm×1.2μm and composed of factory-available structures.The above characteristics of our proposed compact slot-strip converter makes it a promising device for future deployment in multi-functional integrated photonics systems.展开更多
文摘Digital watermarking technology plays an essential role in the work of anti-counterfeiting and traceability.However,image watermarking algorithms are weak against hybrid attacks,especially geometric attacks,such as cropping attacks,rotation attacks,etc.We propose a robust blind image watermarking algorithm that combines stable interest points and deep learning networks to improve the robustness of the watermarking algorithm further.First,to extract more sparse and stable interest points,we use the Superpoint algorithm for generation and design two steps to perform the screening procedure.We first keep the points with the highest possibility in a given region to ensure the sparsity of the points and then filter the robust interest points by hybrid attacks to ensure high stability.The message is embedded in sub-blocks centered on stable interest points using a deep learning-based framework.Different kinds of attacks and simulated noise are added to the adversarial training to guarantee the robustness of embedded blocks.We use the ConvNext network for watermark extraction and determine the division threshold based on the decoded values of the unembedded sub-blocks.Through extensive experimental results,we demonstrate that our proposed algorithm can improve the accuracy of the network in extracting information while ensuring high invisibility between the embedded image and the original cover image.Comparison with previous SOTA work reveals that our algorithm can achieve better visual and numerical results on hybrid and geometric attacks.
基金supported by the National Key Research and Development Program of China(2022YFB2803700)the National Natural Science Foundation of China(62235002,62322501,12204021,62105008,62235003,and 62105260)+5 种基金Beijing Municipal Science and Technology Commission(Z221100006722003)Beijing Municipal Natural Science Foundation(Z210004)China Postdoctoral Science Foundation(2021T140004)Major Key Project of PCL,the Natural Science Basic Research Program of Shaanxi Province(2022 JQ-638)Young Talent fund of University Association for Science and Technology in Shaanxi,China(20220135)Young Talent fund of Xi'an Association for science and technology(095920221308).
文摘Photonic signal processing offers a versatile and promising toolkit for contemporary scenarios ranging from digital optical communication to analog microwave operation.Compared to its electronic counterpart,it eliminates inherent bandwidth limitations and meanwhile exhibits the potential to provide unparalleled scalability and flexibility,particularly through integrated photonics.However,by far the on-chip solutions for optical signal processing are often tailored to specific tasks,which lacks versatility across diverse applications.Here,we propose a streamlined chip-level signal processing architecture that integrates different active and passive building blocks in silicon-on-insulator(SOI)platform with a compact and efficient manner.Comprehensive and in-depth analyses for the architecture are conducted at levels of device,system,and application.Accompanied by appropriate configuring schemes,the photonic circuitry supports loading and processing both analog and digital signals simultaneously.Three distinct tasks are facilitated with one single chip across several mainstream fields,spanning optical computing,microwave photonics,and optical communications.Notably,it has demonstrated competitive performance in functions like image processing,spectrum filtering,and electro-optical bandwidth equalization.Boasting high universality and a compact form factor,the proposed architecture is poised to be instrumental for next-generation functional fusion systems.
文摘Background: Alzheimer’s disease (AD) is an increasingly prevalent neurodegenerative disease characterized by protein aggregation in the form of amyloid plaques containing beta-amyloid peptides and neurofibrillary tangles containing hyperphosphorylated tau protein. The central molecular events underlying AD pathogenesis remain controversial and poorly defined. Drosophila melanogaster has emerged as an important genetic resource for studying the pathology of AD. Many AD models have been created using Drosophila, taking advantage of its short generation times, sophisticated genetic tools, and abundance of homologs to human genes. Purpose: This review summarizes different models for studying AD in Drosophila melanogaster, including the full-length APP, C99, Aβ42 and Tau models, explaining how the models were built and what we have learned from them. Conclusion: Four main AD Drosophila models are introduced in this review, which can serve as a future method to investigate genes and drugs that can modify symptoms.
文摘Alzheimer’s disease (AD) is one of the most significant neurodegenerative disorders in terms of both severity and cost. Despite being defined over a century ago, there is currently no cure to this disease that affects an increasing elderly population. The amyloid precursor protein (APP) has been shown to play an important role in AD progression. The amyloid β peptide (Aβ), which accumulates in senile plaques, a central etiological AD factor, is a proteolytic product from APP by the enzymatic action of β- and γ-secretases. In this review, we summarize the current knowledge of the processing and physiological functions of APP, and the involvement of APP and Aβ in AD.
基金This work was supported by National Key R&D Program of China(2017YFB0602601)National Natural Science Foundation of China(21878093).
文摘In this study,the effect of ash removal on Shenfu bituminous coal was investigated.The coal was pretreated by hydrofluoric acid(HF)pickling,and the raw/pretreated coal chars were prepared at 900°C in a fixed bed reactor.The structure of coal and char were detected by Fourier transform infrared(FTIR)and Raman spectroscopy.The reactivity was tested in a thermogravimetric analyzer,including coal pyrolysis and char gasification.The reaction kinetics was analyzed through the Coats–Redfern method,master plots,the model-free and model-fitting method.The results show that the HF pickling can remove silicon from coal efficiently,and the macromolecular framework of coal is quite stable according to FTIR.The Raman parameters imply some carbonaceous structure on coal surface changed.For slow pyrolysis of coal,the effect of heating rate is considered.The changes of pyrolysis characteristics and kinetics are insignificant.For char gasification,the reactivity under isothermal and non-isothermal condition are discussed with an emphasis in different residence time of devolatilization process.In kinetic control region(low temperature),the activation energy(Ea)is very close(about 240 kJ/mol)for all chars.With the temperature increases,the reactivity of raw coal char is more easily suffered by diffusion.The random pore model is more suitable for the ash-free coal char,and the char with long residence time has a larger value of structural parameterψand smaller value of pre-exponential factor A.The Ea calculated by model-fitting and model-free method were in good agreement.
基金The author would like to appreciate the funding supports of the State of Wyoming and China Scholarship Council.Without their supports,the international collaboration on clean energy technology development would have been impossible.
文摘In this study,the Powder River Basin(PRB)coal fast pyrolysis was conducted at 700°C in the atmosphere of syngas produced by CH4-CO2 reforming in two different patterns,including the double reactors pattern(the first reactor is for syngas production and the second is for coal pyrolysis)and double layers pattern(catalyst was at upper layer and coal was at lower layer).Besides,pure gases atmosphere including N2,H2,CO,H2-CO were also tested to investigate the mechanism of the coal pyrolysis under different atmospheres.The pyrolysis products including gas,liquid and char were characterized,the result showed that,compared with the inert atmosphere,the tar yield is improved with the reducing atmospheres,as well as the tar quality.The hydrogen partial pressure is the key point for that improvement.In the atmosphere of H2,the tar yield was increased by 31.3%and the contained BTX(benzene,toluene and xylene)and naphthalene were increased by 27.1%and 133.4%.The double reactors pattern also performed outstandingly,with 25.4%increment of tar yield and 25.0%and 79.4%for the BTX and naphthalene.The double layers pattern is not effective enough due to the low temperature(700°C)in which the Ni-based catalyst was not fully activated.
基金supported in part by the National Natural Science Foundation of China(T2225023,62205202)the Shanghai Sailing Program(No.22YF1420200)。
文摘Sharing the hardware platform between diverse information systems to establish full cooperation among different functionalities has attracted substantial attention.However,broadband multifunctional integrated systems with large operating frequency ranges are challenging due to the bandwidth and computing speed restrictions of electronic circuitry.Here,we report an analog parallel processor(APP)based on the silicon photonic platform that directly discretizes and parallelizes the broadband signal in the analog domain.The APP first discretizes the signal with the optical frequency comb and then adopts optical dynamic phase interference to reassign the analog signal into 2N parallel sequences.Via photonic analog parallelism,data rate and data volume in each sequence are simultaneously compressed,which mitigates the requirement on each parallel computing core.Moreover,the fusion of the outputs from each computing core is equivalent to directly processing broadband signals.In the proof-of-concept experiment,two-channel analog parallel processing of broadband radar signals and high-speed communication signals is implemented on the single photonic integrated circuit.The bandwidth of broadband radar signal is 6 GHz and the range resolution of 2.69 cm is achieved.The wireless communication rate of 8 Gbit/s is also validated.Breaking the bandwidth and speed limitations of the single-computing core along with further exploring the multichannel potential of this architecture,we anticipate that the proposed APP will accelerate the development of powerful optoelectronic processors as critical support for applications such as satellite networks and intelligent driving.
基金the National Natural Science Foundation of China(U21A2059).
文摘The catalytic coal gasification technology has been widely researched and developed under the background of“Carbon peaking and carbon neutrality goals”.Currently,most of catalytic gasification experiments on coal char particles are analyzed by thermogravimetric analyzer(TGA).However,the gasification agent will be subject to diffusion resistance during the reaction because of the sample stacking,making the inherent reaction kinetics unclear.In this study,we investigated the catalytic gasification behavior of single-particle coal char using high temperature stage microscope(HTSM).With the diffusion resistance ruled out,the reaction conditions when using a HTSM are more similar to those inside a real industrial gasifier.Numerical models of the gasification reaction of single-particle coal char were further developed using the kinetic parameters obtained under HTSM.Three models were investigated,including regular spherical structured,irregular spherical structured and porous spherical structured models,representing different morphologies of coal char particles in the gasifier.The gasification characteristics of coal char particles under different K_(2)CO_(3)catalyst loadings and gasification temperatures were also studied.Compared with the activation energies data of coal char particles without catalyst,the activation energies of coal char particles loaded with 2.2%,4.4%,6.6%,and 10.0%catalysts were reduced by 110 kJ/mol,116 kJ/mol,121 kJ/mol,and 126 kJ/mol,respectively.The reaction surface area affects the temperature distribution.The temperature near the irregular spherical particle is about 20 K higher than the temperature near the regular spherical particle.
基金supported by the National Key Research and Development Program of China(2022YFB2803700)National Natural Science Foundation of China(62235002,62322501,12204021)+3 种基金Beijing Municipal Science and Technology Commission(Z221100006722003)Beijing Municipal Natural Science Foundation(Z210004)Nantong Science and Technology Bureau(JB2022008,JC22022050)High-performance Computing Platform of Peking University。
文摘Harnessing optical supermode interaction to construct artificial photonic molecules has uncovered a series of fundamental optical phenomena analogous to atomic physics.Previously,the distinct energy levels and interactions in such two-level systems were provided by coupled microresonators.The reconfigurability is limited,as they often require delicate external field stimuli or mechanically altering the geometric factors.These highly specific approaches also limit potential applications.Here,we propose a versatile on-chip photonic molecule in a multimode microring,utilizing a flexible regulation methodology to dynamically control the existence and interaction strength of spatial modes.The transition between single/multi-mode states enables the“switched-off/on”functionality of the photonic molecule,supporting wider generalized applications scenarios.In particular,“switched-on”state shows flexible and multidimensional mode splitting control in aspects of both coupling strength and phase difference,equivalent to the a.c.and d.c.Stark effect.“Switched-off”state allows for perfect low-loss single-mode transition(Qi~10 million)under an ultra-compact bend size(FSR~115 GHz)in a foundry-based silicon microring.It breaks the stereotyped image of the FSR-Q factor trade-off,enabling ultra-wideband and high-resolution millimeter-wave photonic operations.Our demonstration provides a flexible and portable solution for the integrated photonic molecule system,extending its research scope from fundamental physics to real-world applications such as nonlinear optical signal processing and sixth-generation wireless communication.
基金National Key Research and Development Program of China(2021YFB2800400)National Natural Science Foundation of China(12204021,62105008,62235002,62235003,62322501,8200908114)+3 种基金Beijing Municipal Science and Technology Commission(Z221100006722003)Natural Science Foundation of Beijing Municipality(Z210004)Nantong Municipal Science and Technology Bureau(JB2022008,JC22022050)China Postdoctoral Science Foundation(2021T140004)。
文摘Self-injection locking has emerged as a crucial technique for coherent optical sources,spanning from narrow linewidth lasers to the generation of localized microcombs.This technique involves key components,namely a laser diode and a high-quality cavity that induces narrow-band reflection back into the laser diode.However,in prior studies,the reflection mainly relied on the random intracavity Rayleigh backscattering,rendering it unpredictable and unsuitable for large-scale production and wide-band operation.In this work,we present a simple approach to achieve reliable intracavity reflection for self-injection locking to address this challenge by introducing a Sagnac loop into the cavity.This method guarantees robust reflection for every resonance within a wide operational band without compromising the quality factor or adding complexity to the fabrication process.As a proof of concept,we showcase the robust generation of narrow linewidth lasers and localized microcombs locked to different resonances within a normal-dispersion microcavity.Furthermore,the existence and generation of localized patterns in a normal-dispersion cavity with broadband forward–backward field coupling is first proved,as far as we know,both in simulation and in experiment.Our research offers a transformative approach to self-injection locking and holds great potential for large-scale production.
基金National Key Research and Development Program of China(2021YFB2800400)National Natural Science Foundation of China(12204021,62105008,62235002,62235003,62322501,8200908114)+3 种基金Beijing Municipal Science and Technology Commission(Z221100006722003)Natural Science Foundation of Beijing Municipality(Z210004)Nantong Municipal Science and Technology Bureau(JB2022008,JC22022050)China Postdoctoral Science Foundation(2021T140004).
文摘Self-injection locking has emerged as a crucial technique for coherent optical sources,spanning from narrow linewidth lasers to the generation of localized microcombs.This technique involves key components,namely a laser diode and a high-quality cavity that induces narrow-band reflection back into the laser diode.However,in prior studies,the reflection mainly relied on the random intracavity Rayleigh backscattering,rendering it unpredictable and unsuitable for large-scale production and wide-band operation.In this work,we present a simple approach to achieve reliable intracavity reflection for self-injection locking to address this challenge by introducing a Sagnac loop into the cavity.This method guarantees robust reflection for every resonance within a wide operational band without compromising the quality factor or adding complexity to the fabrication process.As a proof of concept,we showcase the robust generation of narrow linewidth lasers and localized microcombs locked to different resonances within a normal-dispersion microcavity.Furthermore,the existence and generation of localized patterns in a normal-dispersion cavity with broadband forward–backward field coupling is first proved,as far as we know,both in simulation and in experiment.Our research offers a transformative approach to self-injection locking and holds great potential for large-scale production.
基金This work is supported in part by the National Key Research and Development Program of China(Program no.2019YFB2203700)the National Natural Science Foundation of China(Grant no.61822508).
文摘Optical implementations of neural networks(ONNs)herald the next-generation high-speed and energy-efficient deep learning computing by harnessing the technical advantages of large bandwidth and high parallelism of optics.However,due to the problems of the incomplete numerical domain,limited hardware scale,or inadequate numerical accuracy,the majority of existing ONNs were studied for basic classification tasks.Given that regression is a fundamental form of deep learning and accounts for a large part of current artificial intelligence applications,it is necessary to master deep learning regression for further development and deployment of ONNs.Here,we demonstrate a silicon-based optical coherent dot-product chip(OCDC)capable of completing deep learning regression tasks.The OCDC adopts optical fields to carry out operations in the complete real-value domain instead of in only the positive domain.Via reusing,a single chip conducts matrix multiplications and convolutions in neural networks of any complexity.Also,hardware deviations are compensated via in-situ backpropagation control provided the simplicity of chip architecture.Therefore,the OCDC meets the requirements for sophisticated regression tasks and we successfully demonstrate a representative neural network,the AUTOMAP(a cutting-edge neural network model for image reconstruction).The quality of reconstructed images by the OCDC and a 32-bit digital computer is comparable.To the best of our knowledge,there is no precedent of performing such state-of-the-art regression tasks on ONN chips.It is anticipated that the OCDC can promote the novel accomplishment of ONNs in modern AI applications including autonomous driving,natural language processing,and scientific study.
基金National Key Research and Development Program of China(2021YFB2800400,2022YFB2803700)National Natural Science Foundation of China(62235002,12204021,62001010)+2 种基金Beijing Municipal Science and Technology Commission(Z221100006722003)Beijing Municipal Natural Science Foundation(Z210004)Nantong Science and Technology Bureau(JC2021002)。
文摘Integrated microwave photonic filters(IMPFs)are capable of offering unparalleled performances in terms of superb spectral fineness,broadband,and more importantly,the reconfigurability,which encounter the trend of the next-generation wireless communication.However,to achieve high reconfigurability,previous works should adopt complicated system structures and modulation formats,which put great pressure on power consumption and controlment,and,therefore,impede the massive deployment of IMPF.Here,we propose a streamlined architecture for a wideband and highly reconfigurable IMPF on the silicon photonics platform.For various practical filter responses,to avoid complex auxiliary devices and bias drift problems,a phase-modulated flexible sideband cancellation method is employed based on the intensity-consistent single-stage-adjustable cascadedmicroring(ICSSA-CM).The IMPF exhibits an operation band extending to millimeter-wave(≥30 GHz),and other extraordinary performances including high spectral resolution of 220 MHz and large rejection ratio of 60 d B are obtained.Moreover,Gb/s-level RF wireless communications are demonstrated for the first time towards real-world scenarios.The proposed IMPF provides broadband flexible spectrum control capabilities,showing great potential in the next-generation wireless communication.
基金National Natural Science Foundation of China(61635001,62001010)National Key Research and Development Program of China(2020YFB2206100)+1 种基金Beijing Key Research and Development Project(Z19110004819006)China National Postdoctoral Program for Innovative Talents(BX20200017)。
文摘The integrated microwave photonic filter(MPF),as a compelling candidate for next-generation radio-frequency(RF)applications,has been widely investigated for decades.However,most integrated MPFs reported thus far have merely incorporated passive photonic components onto a chip-scale platform,while all necessary active devices are still bulk and discrete.Though few attempts to higher photonic integration of MPFs have been executed,the achieved filtering performances are fairly limited,which impedes the pathway to practical deployments.Here,we demonstrate,for the first time to our knowledge,an all-integrated MPF combined with high filtering performances,through hybrid integration of an In P chip-based laser and a monolithic silicon photonic circuit consisting of a dual-drive Mach–Zehnder modulator,a high-Q ring resonator,and a photodetector.This integrated MPF exhibits a high spectral resolution as narrow as 360 MHz,a wide-frequency tunable range covering the S-band to K-band(3 to 25 GHz),and a large rejection ratio of>40 d B.Moreover,the filtering response can be agilely switched between the bandpass and band-stop function with a transient respond time(48μs).Compared with previous MPFs in a similar integration level,the obtained spectral resolution in this work is dramatically improved by nearly one order of magnitude,while the valid frequency tunable range is broadened more than twice,which can satisfy the essential filtering requirements in actual RF systems.As a paradigm demonstration oriented to real-world scenarios,high-resolution RF filtering of realistic microwave signals aiming for interference rejection and channel selection is performed.Our work points out a feasible route to a miniaturized,high-performance,and cost-effective MPF leveraging hybrid integration approach,thus enabling a range of RF applications from wireless communication to radar toward the higher-frequency region,more compact size,and lower power consumption.
基金National Key Research and Development Program of China(2021YFB2800802)National Natural Science Foundation of China(61771285)。
文摘Microwave photonic receivers are a promising candidate in breaking the bandwidth limitation of traditional radio-frequency(RF)receivers.To further balance the performance superiority with the requirements regarding size,weight,and power consumption(SWa P),the implementation of integrated microwave photonic microsystems has been considered an upgrade path.However,up to now,to the best of our knowledge,chip-scale fully integrated microwave photonic receivers have not been reported due to the limitation of material platforms.In this paper,we report a fully integrated hybrid microwave photonic receiver(FIH-MWPR)obtained by comprising the indium phosphide(In P)laser chip and the monolithic silicon-on-insulator(SOI)photonic circuit into the same substrate based on the low-coupling-loss micro-optics method.Benefiting from the integration of all optoelectronic components,the packaged FIH-MWPR exhibits a compact volume of 6 cmand low power consumption of 1.2 W.The FIH-MWPR supports a wide operation bandwidth from 2 to 18 GHz.Furthermore,its RF-link performance to down-convert the RF signals to the intermediate frequency is experimentally characterized by measuring the link gain,the noise figure,and the spurious-free dynamic range metrics across the whole operation frequency band.Moreover,we have utilized it as a de-chirp receiver to process the broadband linear frequencymodulated(LFM)radar echo signals at different frequency bands(S-,C-,X-,and Ku-bands)and successfully demonstrated its high-resolution-ranging capability.To the best of our knowledge,this is the first realization of a chip-scale broadband fully integrated microwave photonic receiver,which is expected to be an important step in demonstrating the feasibility of all-integrated microwave photonic microsystems oriented to miniaturized application scenarios.
文摘Microcombs are revolutionizing optoelectronics by providing parallel, mutually coherent wavelengthchannels for time-frequency metrology and information processing. To implement this essential function inintegrated photonic systems, it is desirable to drive microcombs directly with an on-chip laser in a simpleand flexible way. However, two major difficulties have prevented this goal: (1) generating mode-lockedcomb states usually requires a significant amount of pump power and (2) the requirement to align laser andresonator frequency significantly complicates operation and limits the tunability of the comb lines. Here, weaddress these problems by using microresonators on an AlGaAs on-insulator platform to generate dark-pulsemicrocombs. This highly nonlinear platform dramatically relaxes fabrication requirements and leads to arecord-low pump power of <1 mW for coherent comb generation. Dark-pulse microcombs facilitated bythermally controlled avoided mode crossings are accessed by direct distributed feedback laser pumping.Without any feedback or control circuitries, the comb shows good coherence and stability. With around150 mW on-chip power, this approach also leads to an unprecedentedly wide tuning range of over one freespectral range (97.5 GHz). Our work provides a route to realize power-efficient, simple, and reconfigurablemicrocombs that can be seamlessly integrated with a wide range of photonic systems.
基金National Key Research and Development Program of China(2021YFB0301000,2020YFB2206100,2022YFB2803700)
文摘A hybrid integrated 16-channel silicon transmitter based on co-designed photonic integrated circuits(PICs) and electrical chiplets is demonstrated. The driver in the 65 nm CMOS process employs the combination of a distributed architecture, two-tap feedforward equalization(FFE), and a push–pull output stage, exhibiting an estimated differential output swing of 4.0V_(pp). The rms jitter of 2.0 ps is achieved at 50 Gb/s under nonreturnto-zero on–off keying(NRZ-OOK) modulation. The PICs are fabricated on a standard silicon-on-insulator platform and consist of 16 parallel silicon dual-drive Mach–Zehnder modulators on a single chip. The chip-on-board co-packaged Si transmitter is constituted by the multichannel chiplets without any off-chip bias control, which significantly simplifies the system complexity. Experimentally, the open and clear optical eye diagrams of selected channels up to 50 Gb/s OOK with extinction ratios exceeding 3 dB are obtained without any digital signal processing. The power consumption of the Si transmitter with a high integration density featuring a throughput up to 800 Gb/s is only 5.35 p J/bit, indicating a great potential for massively parallel terabit-scale optical interconnects for future hyperscale data centers and high-performance computing systems.
基金This work was funded by the National Key Research and Development Program of China(No.2018YFB2201704)the National Natural Science Foundation of China(Grant Nos.61635001 and 62105008)+2 种基金China National Postdoctoral Program for Innovative Talents(No.BX20200017)China Postdoctoral Science Foundation(No.2021T140004)the Major Key Project of PCL(No.PCL2021A14)。
文摘Integrated waveguides with slot structures have attracted increasing attention due to their advantages of tight mode confinement and strong light-matter interaction.Although extensively studied,the issue of mode mismatch with other strip waveguide-based optical devices is a huge challenge that prevents integrated waveguides from being widely utilized in large-scale photonic-based circuits.In this paper,we demonstrate an ultra-compact low-loss slot-strip converter with polarization insensitivity based on the multimode interference(MMI)effect.Sleek sinusoidal profiles are adopted to allow for smooth connection between the slot and strip waveguide,resulting reflection reduction.By manipulating the MMI effect with structure optimization,the self-imaging positions of the TE0 and TM0 modes are aligned with minimized footprint,leading to low-loss transmission for both polarizations.The measurement results show that high coupling efficiencies of−0.40 and−0.64 dB are achieved for TE_(0) and TM_(0) polarizations,respectively.The device has dimensions as small as 1.1μm×1.2μm and composed of factory-available structures.The above characteristics of our proposed compact slot-strip converter makes it a promising device for future deployment in multi-functional integrated photonics systems.
