Valley, the intrinsic feature of silicon, is an inescapable subject in silicon-based quantum computing. At the spin–valley hotspot, both Rabi frequency and state relaxation rate are significantly enhanced. With prote...Valley, the intrinsic feature of silicon, is an inescapable subject in silicon-based quantum computing. At the spin–valley hotspot, both Rabi frequency and state relaxation rate are significantly enhanced. With protection against charge noise, the valley degree of freedom is also conceived to encode a qubit to realize noise-resistant quantum computing.Here, based on the spin qubit composed of one or three electrons, we characterize the intrinsic properties of valley in an isotopically enriched silicon quantum dot(QD) device. For one-electron qubit, we measure two electric-dipole spin resonance(EDSR) signals which are attributed to partial occupation of two valley states. The resonance frequencies of two EDSR signals have opposite electric field dependences. Moreover, we characterize the electric field dependence of the upper valley state based on three-electron qubit experiments. The difference of electric field dependences of the two valleys is 52.02 MHz/V, which is beneficial for tuning qubit frequency to meet different experimental requirements. As an extension of electrical control spin qubits, the opposite electric field dependence is crucial for qubit addressability,individual single-qubit control and two-qubit gate approaches in scalable quantum computing.展开更多
The single-shot readout data process is essential for the realization of high-fidelity qubits and fault-tolerant quantum algorithms in semiconductor quantum dots. However, the fidelity and visibility of the readout pr...The single-shot readout data process is essential for the realization of high-fidelity qubits and fault-tolerant quantum algorithms in semiconductor quantum dots. However, the fidelity and visibility of the readout process are sensitive to the choice of the thresholds and limited by the experimental hardware. By demonstrating the linear dependence between the measured spin state probabilities and readout visibilities along with dark counts, we describe an alternative threshold-independent method for the single-shot readout of spin qubits in semiconductor quantum dots. We can obtain the extrapolated spin state probabilities of the prepared probabilities of the excited spin state through the threshold-independent method. We then analyze the corresponding errors of the method, finding that errors of the extrapolated probabilities cannot be neglected with no constraints on the readout time and threshold voltage. Therefore, by limiting the readout time and threshold voltage, we ensure the accuracy of the extrapolated probability. We then prove that the efficiency and robustness of this method are 60 times larger than those of the most commonly used method. Moreover, we discuss the influence of the electron temperature on the effective area with a fixed external magnetic field and provide a preliminary demonstration for a single-shot readout of up to 0.7K/1.5T in the future.展开更多
In this theoretical work,we describe a mechanism for the coupling between a plane structure consisting of four quantum dots and a resonator.We systematically study the dependence of the quadruple coupling strength and...In this theoretical work,we describe a mechanism for the coupling between a plane structure consisting of four quantum dots and a resonator.We systematically study the dependence of the quadruple coupling strength and the qubit decoherence rate and point out the optimized operating position of the hybrid system.According to the transmission given by the input-output theory,the signatures in the resonator spectrum are predicted.Furthermore,based on the parameters already achieved in previous works,we prove that the device described in this paper can achieve the strong coupling limit,i.e.,this approach can be used for system extension under the existing technical conditions.Our results show an effective and promotable approach to couple quantum dot structures in plane with the resonator and propose a meaningful extension method.展开更多
Hybrid qubits enable the hybridization of charge and spin degrees of freedom,which provides a way to realize both a relatively long coherence time and rapid qubit manipulation.Here,we use microwave driving to demonstr...Hybrid qubits enable the hybridization of charge and spin degrees of freedom,which provides a way to realize both a relatively long coherence time and rapid qubit manipulation.Here,we use microwave driving to demonstrate the coherent operation of a tunable hybrid qubit,including X-rotation,Z-rotation,and rotation around an arbitrary axis in the X-Y panel of the Bloch sphere.Moreover,the coherence properties of the qubit and its tunability are studied.The measured coherence time of the X-rotation reaches~14.3 ns.While for the Z-rotation,the maximum decoherence time is~5.8 ns due to the larger sensitivity to noise.By employing the Hahn echo sequence to mitigate the influence of the low-frequency noise,we have improved the qubit coherence time from~5.8 ns to~15.0 ns.Our results contribute to a further understanding of the hybrid qubit and a step towards achieving high-fidelity qubit gates in the hybrid qubit.展开更多
Single-cell and spatial-omic technologies are providing unprecedented detail into the molecular principles underlying a wide range of developmental and disease contexts.These observations are substantially deepening m...Single-cell and spatial-omic technologies are providing unprecedented detail into the molecular principles underlying a wide range of developmental and disease contexts.These observations are substantially deepening many areas of biological research.However,despite the increasing application of these techniques to biological problems we are only revealing the tip of the iceberg,and there exist large gaps in our understanding of the behavior of single cells in vitro and in vivo that need to be filled.Additionally,the development of robust analytical tools and meta-analysis of existing data lag behind the rapid generation of new data.展开更多
The presence of anticrossings induced by coupling between two states causes curvature in energy levels, yielding a nonlinearity in the quantum system. When the system is driven back and forth along the bending energy ...The presence of anticrossings induced by coupling between two states causes curvature in energy levels, yielding a nonlinearity in the quantum system. When the system is driven back and forth along the bending energy levels, subharmonic transitions and energy shifts can be observed, which would cause a significant influence as the system is applied to quantum computing. In this paper, we study a longitudinally driven singlet-triplet(ST) system in a double quantum dot(DQD)system, and illustrate the consequences of nonlinearity by driving the system close to the anticrossings. We provide a straightforward theory to quantitatively describe the energy shift and subharmonics caused by nonlinearity, and find good agreement between our theoretical result and the numerical simulation. Our results reveal the existence of nonlinearity in the vicinity of anticrossings and provide a direct way of analytically assessing its impact, which can be applied to other quantum systems without excessive labor.展开更多
Mycobacterium tuberculosis(M.tuberculosis)can replicate in the macrophage by interfering with many host protein functions.While it is far from known these host proteins for controlling M.tuberculosis infection.Herein,...Mycobacterium tuberculosis(M.tuberculosis)can replicate in the macrophage by interfering with many host protein functions.While it is far from known these host proteins for controlling M.tuberculosis infection.Herein,we infected macrophages including THP-1 and Raw264.7 cells with M.tuberculosis and identified the differentially expressed genes(DEGs)in the interferon signaling pathway.Among them,2'-5'oligoadenylate synthetase-like(OASL)underwent the greatest upregulation in M.tuberculosis-infected macrophages.Knockdown of the expression of OASL attenuated M.tuberculosis survival in macrophages.Further,bioinformatics analysis revealed the potential interaction axis of OASL-TAB3-RvO127,which was further validated by the yeast-two-hybrid(Y2H)assay and Co-IP.This interaction axis might regulate the M.tuberculosis survival and proliferation in macrophages.The study reveals a possible role of OASL during M.tuberculosis infection as a target to control its propagation.展开更多
In head mounted display(HMD),in order to cancel pincushion distortion,the images displayed on the mobile should be prewarped with barrel distortion.The copyright of the mobile video should be verified on both the orig...In head mounted display(HMD),in order to cancel pincushion distortion,the images displayed on the mobile should be prewarped with barrel distortion.The copyright of the mobile video should be verified on both the original view and the pre-warped virtual view.A robust watermarking resistant against barrel distortion for HMDs is proposed in this paper.Watermark mask is embedded into image in consideration of imperceptibility and robustness of watermarking.In order to detect watermark from the pre-warped image with barrel distortion,an estimation method of the barrel distortion is proposed for HMDs.Then,the same warp is enforced on the embedded watermark mask with the estimated parameters of barrel distortion.The correlation between the warped watermark and the pre-warped image is computed to predicate the existence of watermark.As shown in experimental results,watermark of mobile video can be detected not only from the original views,but also from the pre-warped virtual view.It also shows that the proposed scheme is resistant against combined barrel distortion and common post-processing,such as JPEG compression.展开更多
New neuromorphic architectures and memory technologies with low power consumption,scalability and high-speed are in the spotlight due to the von Neumann bottleneck and limitations of Moore’s law.The memristor,a two-t...New neuromorphic architectures and memory technologies with low power consumption,scalability and high-speed are in the spotlight due to the von Neumann bottleneck and limitations of Moore’s law.The memristor,a two-terminal synaptic device,shows powerful capabilities in neuromorphic computing and information storage applications.Active materials with high defect migration speed and low defect migration barrier are highly promising for high-performance memristors.Halide perovskite(HP)materials with point defects(such as gaps,vacancies,and inversions)have strong application potential in memristors.In this article,we review recent advances on HP memristors with exceptional performances.First,the working mechanisms of memristors are described.Then,the structures and properties of HPs are explained.Both electrical and photonic HP-based memristors are overviewed and discussed.Different fabrication methods of HP memristor devices and arrays are described and compared.Finally,the challenges in integrating HP memristors with complementary metal oxide semiconductors(CMOS)are briefly discussed.This review can assist in developing HP memristors for the next-generation information technology.展开更多
Mixed strains Delftia sp.YH01 and Acidovorax sp.YH02,with capability of heterotrophic nitrification-aerobic denitrification,were introduced into a two-stage aerobic sequencing batch reactor to enhance NO3^--N removal....Mixed strains Delftia sp.YH01 and Acidovorax sp.YH02,with capability of heterotrophic nitrification-aerobic denitrification,were introduced into a two-stage aerobic sequencing batch reactor to enhance NO3^--N removal.With optimal C/N of 8,efficient NO3^--N removal was achieved at initial NO3^--N concentration of 2000 mg·L−1.Meanwhile,the massive accumulation of NO2^--N was avoided during the long operation.Compared to the one-stage aerobic sequencing batch reactor,the removal efficiency of NO3^--N and TN in the two-stage aerobic sequencing batch reactor was increased by 36.5% and 42.7%,which respectively was 93.8% and 88.4%.Microbial community study showed that the mixed strains have the stronger viability and can synergistically denitrify with the indigenous microorganisms in system,such as Azoarcus,Uncultured Saprospiraceae,Thauera,Paracocccus,which could be major contributors for aerobic denitrification.The proposed technology was shown to achieve high-efficiency treatment of high NO3^--N wastewater through aerobic denitrification.展开更多
In vito fber photometry is a powerful technique to analyze the dy namics of population neurons during fiunctional study of neuroscience.Here,we introduced a detailed protocol for fiber photometry-based calciun reordin...In vito fber photometry is a powerful technique to analyze the dy namics of population neurons during fiunctional study of neuroscience.Here,we introduced a detailed protocol for fiber photometry-based calciun reording in freely moving mice,covering from virus injection,fiber stub insertion,optogenetical stimulation to data procurement and analysis.Furthemnore,we applied this protocol to explore neuronal activity of mice latenal-posterior(LP)thalaric nucleus in response to optogenetical stimulation of primary visual cortex(V1)neurons,and explore axon clusters activity of optogenetically evoked V1 neurons.Final confirmation of virus-based protein expression in V1 and precise fber insertion indicated that the surgery procedure of this protocol is reliable for functional calcium recording.The scripts for data analysis and some tips in our protocol are provided in details.Together,this protocol is simple,low-cost,and effective for neuronal activity detection by fiber photometry,which will hep neuroscience researchers to carry out fiunctional and behavioral study in vivo.展开更多
Traditionally,optical microscopy is used to visualize the morphological features of pathogenic bacteria,of which the features are further used for the detection and ident ification of the bacteria.However,due to the r...Traditionally,optical microscopy is used to visualize the morphological features of pathogenic bacteria,of which the features are further used for the detection and ident ification of the bacteria.However,due to the resolution limitation of conventional optical microscopy as well as the lack of standard pattern library for bacteria identification,the ffectiveness of this optical microscopy-based method is limited.Here,we reported a pilot study on a combined use of Structured Illumination Microscopy(SIM)with machine learning for rapid bacteria identification.After applying machine learning to the SIM image datasets from three model bacteria(including Escherichia coli,Mycobacterium smegmatis,and Pseudomonas aeruginosa),we obtained a classifcation accuracy of up to 98%.This study points out a promising possibility for rapid bacterial identification by morphological features.展开更多
Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed ...Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed to investigate the transport properties and electric field distribution inside the MAPbI_(3) single crystal detector.Owing to the almost homogeneous electric field built inside the detector during pulsed bias ToF measurement,the free hole mobility can be directly calculated to be about 22 cm^(2)·V^(-1)·s^(-1),and the hole lifetime is around 6.5μs–17.5μs.Hence,the mobility-lifetime product can be derived to be 1.4×10^(-4)cm^(2)·V^(-1)–3.9×10^(-4)cm^(2)·V^(-1).The transit time measured under the DC bias deviates with increasing voltage compared with that under the pulsed bias,which arises mainly from the inhomogeneous electric field distribution inside the perovskite.The positive space charge density can then be deduced to increase from 3.1×10^(10)cm^(-3)to 6.89×10^(10)cm^(-3)in a bias range of 50 V–150 V.The ToF measurement can provide us with a facile way to accurately measure the transport properties of the perovskite single crystals,and is also helpful in obtaining a rough picture of the internal electric field distribution.展开更多
Conerent photon source is an important element that has been widely used in spectroscopy,imaging,detection,and teleportation in quantum optics.However,it is still a challenge to realize micro-scale coherent emitters i...Conerent photon source is an important element that has been widely used in spectroscopy,imaging,detection,and teleportation in quantum optics.However,it is still a challenge to realize micro-scale coherent emitters in semiconductor systems.We report the observation of gain in a cavity-coupled GaAs double quantum dot system with a voltage bias across the device.By characterizing and analyzing the cavity responses to different quantum dot behaviors,we distinguish the microwave photon emission from the signal gain.This study provides a possibility to realize micro-scale amplifiers or coherent microwave photon sources in circuit quantum electrodynamics(cQED) hybrid systems.展开更多
Thirty years of effort in semiconductor quantum dots has resulted in significant developments in the control of spin quantum bits(qubits). The natural two-energy level of spin states provides a path toward quantum i...Thirty years of effort in semiconductor quantum dots has resulted in significant developments in the control of spin quantum bits(qubits). The natural two-energy level of spin states provides a path toward quantum information processing. In particular, the experimental implementation of spin control with high fidelity provides the possibility of realizing quantum computing. In this review, we will discuss the basic elements of spin qubits in semiconductor quantum dots and summarize some important experiments that have demonstrated the direct manipulation of spin states with an applied electric field and/or magnetic field. The results of recent experiments on spin qubits reveal a bright future for quantum information processing.展开更多
We investigate the dephasing mechanisms induced by the charge noise and microwave heating effect acting on a graphene double quantum dot (DQD) capacitively coupled to a microwave resonator. The charge noise is obtai...We investigate the dephasing mechanisms induced by the charge noise and microwave heating effect acting on a graphene double quantum dot (DQD) capacitively coupled to a microwave resonator. The charge noise is obtained from DC transport current, and its contribution to dephasing is simultaneously determined by the amplitude response of the microwave resonator. A lowfrequency 1/f-type noise is demonstrated to be the dominant factor of the dephasing of graphene DQD. Furthermore, when the applied microwave power is larger than -90 dBm, the dephasing rate of graphene DQD increases rapidly with the increase of microwave power, and fluctuates slightly with the applied microwave power smaller than -90 dBm. Our results can be applied to suppress the impeditive influence on the dephasing of graphene-based devices associated with microwave input in the perspective investigations.展开更多
Genome-wide association studies(GWASs) are the most widely used method to identify genetic risk loci associated with orofacial clefts(OFC). However, despite the increasing size of cohort, GWASs are still insufficient ...Genome-wide association studies(GWASs) are the most widely used method to identify genetic risk loci associated with orofacial clefts(OFC). However, despite the increasing size of cohort, GWASs are still insufficient to detect all the heritability,suggesting there are more associations under the current stringent statistical threshold. In this study, we obtained an integrated epigenomic dataset based on the chromatin conformation of a human oral epithelial cell line(HIOEC) using RNA-seq, ATAC-seq,H3K27ac Ch IP-seq, and DLO Hi-C. Presumably, this epigenomic dataset could reveal the missing functional variants located in the oral epithelial cell active enhancers/promoters along with their risk target genes, despite relatively less-stringent statistical association with OFC. Taken a non-syndromic cleft palate only(NSCPO) GWAS data of the Chinese Han population as an example, 3664 SNPs that cannot reach the strict significance threshold were subjected to this functional identification pipeline.In total, 254 potential risk SNPs residing in active cis-regulatory elements interacting with 1 718 promoters of oral epitheliumexpressed genes were screened. Gapped k-mer machine learning based on enhancers interacting with epithelium-expressed genes along with in vivo and in vitro reporter assays were employed as functional validation. Among all the potential SNPs, we chose and confirmed that the risk alleles of rs560789 and rs174570 reduced the epithelial-specific enhancer activity by preventing the binding of transcription factors related to epithelial development. In summary, we established chromatin conformation datasets of human oral epithelial cells and provided a framework for testing and understanding how regulatory variants impart risk for clefts.展开更多
This paper reviews the studies of using FTIR to investigate the components of aerosols produced in smog chamber experiments and collected in atmosphere. The fact that aerosols are mixture of small amount of countless ...This paper reviews the studies of using FTIR to investigate the components of aerosols produced in smog chamber experiments and collected in atmosphere. The fact that aerosols are mixture of small amount of countless individual compounds makes the analysis of aerosol constituents very challenging. Although a number of advanced instruments have been applied to the chemical characterization of aerosol components, the majority of aerosol components, particularly the organics, remain unknown. Being supplemental to the traditional quantitative instruments, FTIR has been recently used either individually or combining with other analytical instruments to characterize the components of aerosol particles. This paper aims to show how FTIR is applied to analysis of organic aerosols in current literature and to summarize the FTIR characteristic peak frequencies that are widely seen in the FTIR measurement of organic aerosols. It will be greatly helpful to researchers whose studies are focused on the analysis of aerosol components.展开更多
Mesenchymal stem cells?(MSCs) have been shown to differentiate into liver cells in serum of part-resection liver, but it was hardly feasible in clinical use. Our studies revealed that MSCs could differentiate into hep...Mesenchymal stem cells?(MSCs) have been shown to differentiate into liver cells in serum of part-resection liver, but it was hardly feasible in clinical use. Our studies revealed that MSCs could differentiate into hepatocyte-like cells in autologous serum after radiofrequency ablation (RFA) therapy of the liver tumor. Rabbits with liver tumor subsequently treated with RFA therapy. Serum was collected from those rabbits before RFA therapy and 72 hours after RFA therapy. MSCs were isolated from each rabbit’s bone marrow and cultured in DMEM medium containing the following different supplements: 30% fetal calf serum (FCS group), 30% rabbit autologous serum (AS group) or 30% autologous serum after RFA treatment of the liver tumor (ASRF group), observed by electron microscopy, flow cytometry, immunofluorescence. Seven days later, most of the spindle-shaped MSCs in the ASRF group transformed into polygon or round-shaped cells resembling hepatocytes, and the percentage in S/G2/M phase was higher than in the FCS or AS groups. Fourteen days later, slender microvilli, cell-cell junction structures and cholangiole emerged in the cells belonging to the ASRF group, the expression of albumin and CK18 was observed only in the differentiated cells from the ASRF group. These changes were not observed in the FCS group or the AS group. This study may provide a potential cell source and culture process for clinical application in liver injury treatment.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12074368, 92165207, 12034018, and 92265113)the Innovation Program for Quantum Science and Technology (Grant No. 2021ZD0302300)+1 种基金the Anhui Province Natural Science Foundation (Grant No. 2108085J03)the USTC Tang Scholarship。
文摘Valley, the intrinsic feature of silicon, is an inescapable subject in silicon-based quantum computing. At the spin–valley hotspot, both Rabi frequency and state relaxation rate are significantly enhanced. With protection against charge noise, the valley degree of freedom is also conceived to encode a qubit to realize noise-resistant quantum computing.Here, based on the spin qubit composed of one or three electrons, we characterize the intrinsic properties of valley in an isotopically enriched silicon quantum dot(QD) device. For one-electron qubit, we measure two electric-dipole spin resonance(EDSR) signals which are attributed to partial occupation of two valley states. The resonance frequencies of two EDSR signals have opposite electric field dependences. Moreover, we characterize the electric field dependence of the upper valley state based on three-electron qubit experiments. The difference of electric field dependences of the two valleys is 52.02 MHz/V, which is beneficial for tuning qubit frequency to meet different experimental requirements. As an extension of electrical control spin qubits, the opposite electric field dependence is crucial for qubit addressability,individual single-qubit control and two-qubit gate approaches in scalable quantum computing.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12074368,92165207,12034018,and 62004185)the Anhui Province Natural Science Foundation (Grant No.2108085J03)the USTC Tang Scholarship。
文摘The single-shot readout data process is essential for the realization of high-fidelity qubits and fault-tolerant quantum algorithms in semiconductor quantum dots. However, the fidelity and visibility of the readout process are sensitive to the choice of the thresholds and limited by the experimental hardware. By demonstrating the linear dependence between the measured spin state probabilities and readout visibilities along with dark counts, we describe an alternative threshold-independent method for the single-shot readout of spin qubits in semiconductor quantum dots. We can obtain the extrapolated spin state probabilities of the prepared probabilities of the excited spin state through the threshold-independent method. We then analyze the corresponding errors of the method, finding that errors of the extrapolated probabilities cannot be neglected with no constraints on the readout time and threshold voltage. Therefore, by limiting the readout time and threshold voltage, we ensure the accuracy of the extrapolated probability. We then prove that the efficiency and robustness of this method are 60 times larger than those of the most commonly used method. Moreover, we discuss the influence of the electron temperature on the effective area with a fixed external magnetic field and provide a preliminary demonstration for a single-shot readout of up to 0.7K/1.5T in the future.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.92265113,12074368,and 12034018).
文摘In this theoretical work,we describe a mechanism for the coupling between a plane structure consisting of four quantum dots and a resonator.We systematically study the dependence of the quadruple coupling strength and the qubit decoherence rate and point out the optimized operating position of the hybrid system.According to the transmission given by the input-output theory,the signatures in the resonator spectrum are predicted.Furthermore,based on the parameters already achieved in previous works,we prove that the device described in this paper can achieve the strong coupling limit,i.e.,this approach can be used for system extension under the existing technical conditions.Our results show an effective and promotable approach to couple quantum dot structures in plane with the resonator and propose a meaningful extension method.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.92265113,12074368,and 12034018)the USTC Tang Scholarship。
文摘Hybrid qubits enable the hybridization of charge and spin degrees of freedom,which provides a way to realize both a relatively long coherence time and rapid qubit manipulation.Here,we use microwave driving to demonstrate the coherent operation of a tunable hybrid qubit,including X-rotation,Z-rotation,and rotation around an arbitrary axis in the X-Y panel of the Bloch sphere.Moreover,the coherence properties of the qubit and its tunability are studied.The measured coherence time of the X-rotation reaches~14.3 ns.While for the Z-rotation,the maximum decoherence time is~5.8 ns due to the larger sensitivity to noise.By employing the Hahn echo sequence to mitigate the influence of the low-frequency noise,we have improved the qubit coherence time from~5.8 ns to~15.0 ns.Our results contribute to a further understanding of the hybrid qubit and a step towards achieving high-fidelity qubit gates in the hybrid qubit.
文摘Single-cell and spatial-omic technologies are providing unprecedented detail into the molecular principles underlying a wide range of developmental and disease contexts.These observations are substantially deepening many areas of biological research.However,despite the increasing application of these techniques to biological problems we are only revealing the tip of the iceberg,and there exist large gaps in our understanding of the behavior of single cells in vitro and in vivo that need to be filled.Additionally,the development of robust analytical tools and meta-analysis of existing data lag behind the rapid generation of new data.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12074368, 92165207, 12034018 and 92265113)the Anhui Province Natural Science Foundation (Grant No. 2108085J03)。
文摘The presence of anticrossings induced by coupling between two states causes curvature in energy levels, yielding a nonlinearity in the quantum system. When the system is driven back and forth along the bending energy levels, subharmonic transitions and energy shifts can be observed, which would cause a significant influence as the system is applied to quantum computing. In this paper, we study a longitudinally driven singlet-triplet(ST) system in a double quantum dot(DQD)system, and illustrate the consequences of nonlinearity by driving the system close to the anticrossings. We provide a straightforward theory to quantitatively describe the energy shift and subharmonics caused by nonlinearity, and find good agreement between our theoretical result and the numerical simulation. Our results reveal the existence of nonlinearity in the vicinity of anticrossings and provide a direct way of analytically assessing its impact, which can be applied to other quantum systems without excessive labor.
基金funded by the National Natural Science Foundation of China(Grant No.31602061,U21A20259,31872470)the National Key Research and Development Program of China(Grant No.2021YFD1800401).
文摘Mycobacterium tuberculosis(M.tuberculosis)can replicate in the macrophage by interfering with many host protein functions.While it is far from known these host proteins for controlling M.tuberculosis infection.Herein,we infected macrophages including THP-1 and Raw264.7 cells with M.tuberculosis and identified the differentially expressed genes(DEGs)in the interferon signaling pathway.Among them,2'-5'oligoadenylate synthetase-like(OASL)underwent the greatest upregulation in M.tuberculosis-infected macrophages.Knockdown of the expression of OASL attenuated M.tuberculosis survival in macrophages.Further,bioinformatics analysis revealed the potential interaction axis of OASL-TAB3-RvO127,which was further validated by the yeast-two-hybrid(Y2H)assay and Co-IP.This interaction axis might regulate the M.tuberculosis survival and proliferation in macrophages.The study reveals a possible role of OASL during M.tuberculosis infection as a target to control its propagation.
基金partially supported by Fundamental Research Funds for the Central Universities of China(2016JKF01203)National Natural Science Foundation of China(61401408,61402484,and 61502160)
文摘In head mounted display(HMD),in order to cancel pincushion distortion,the images displayed on the mobile should be prewarped with barrel distortion.The copyright of the mobile video should be verified on both the original view and the pre-warped virtual view.A robust watermarking resistant against barrel distortion for HMDs is proposed in this paper.Watermark mask is embedded into image in consideration of imperceptibility and robustness of watermarking.In order to detect watermark from the pre-warped image with barrel distortion,an estimation method of the barrel distortion is proposed for HMDs.Then,the same warp is enforced on the embedded watermark mask with the estimated parameters of barrel distortion.The correlation between the warped watermark and the pre-warped image is computed to predicate the existence of watermark.As shown in experimental results,watermark of mobile video can be detected not only from the original views,but also from the pre-warped virtual view.It also shows that the proposed scheme is resistant against combined barrel distortion and common post-processing,such as JPEG compression.
基金the financial support from the National Key Research and Development Program of China(Grant Nos.2018YFA0209000,2017YFB0403603)the National Natural Science Foundation of China(Grant Nos.61904173,61634006,61675191,61674050,61874158)+1 种基金the Hundred Persons Plan of Hebei Province(Grant No.E2018050004,E2018050003)the Supporting Plan for 100 Excellent Innovative Talents in Colleges and Universities of Hebei Province(SLRC2019018).
文摘New neuromorphic architectures and memory technologies with low power consumption,scalability and high-speed are in the spotlight due to the von Neumann bottleneck and limitations of Moore’s law.The memristor,a two-terminal synaptic device,shows powerful capabilities in neuromorphic computing and information storage applications.Active materials with high defect migration speed and low defect migration barrier are highly promising for high-performance memristors.Halide perovskite(HP)materials with point defects(such as gaps,vacancies,and inversions)have strong application potential in memristors.In this article,we review recent advances on HP memristors with exceptional performances.First,the working mechanisms of memristors are described.Then,the structures and properties of HPs are explained.Both electrical and photonic HP-based memristors are overviewed and discussed.Different fabrication methods of HP memristor devices and arrays are described and compared.Finally,the challenges in integrating HP memristors with complementary metal oxide semiconductors(CMOS)are briefly discussed.This review can assist in developing HP memristors for the next-generation information technology.
基金supported by grants fromthe Science and Technology Planning Project of Guangzhou City,China(201903010031)the Natural Science Foundation Research Team Project of Guangdong Province,China(2016A030312009).
文摘Mixed strains Delftia sp.YH01 and Acidovorax sp.YH02,with capability of heterotrophic nitrification-aerobic denitrification,were introduced into a two-stage aerobic sequencing batch reactor to enhance NO3^--N removal.With optimal C/N of 8,efficient NO3^--N removal was achieved at initial NO3^--N concentration of 2000 mg·L−1.Meanwhile,the massive accumulation of NO2^--N was avoided during the long operation.Compared to the one-stage aerobic sequencing batch reactor,the removal efficiency of NO3^--N and TN in the two-stage aerobic sequencing batch reactor was increased by 36.5% and 42.7%,which respectively was 93.8% and 88.4%.Microbial community study showed that the mixed strains have the stronger viability and can synergistically denitrify with the indigenous microorganisms in system,such as Azoarcus,Uncultured Saprospiraceae,Thauera,Paracocccus,which could be major contributors for aerobic denitrification.The proposed technology was shown to achieve high-efficiency treatment of high NO3^--N wastewater through aerobic denitrification.
基金supported by the National Natural Science Foundation of China (Grant Nos.31371106 and 91632110)HZAU Independent Innovation Fund (2014BQ019).
文摘In vito fber photometry is a powerful technique to analyze the dy namics of population neurons during fiunctional study of neuroscience.Here,we introduced a detailed protocol for fiber photometry-based calciun reording in freely moving mice,covering from virus injection,fiber stub insertion,optogenetical stimulation to data procurement and analysis.Furthemnore,we applied this protocol to explore neuronal activity of mice latenal-posterior(LP)thalaric nucleus in response to optogenetical stimulation of primary visual cortex(V1)neurons,and explore axon clusters activity of optogenetically evoked V1 neurons.Final confirmation of virus-based protein expression in V1 and precise fber insertion indicated that the surgery procedure of this protocol is reliable for functional calcium recording.The scripts for data analysis and some tips in our protocol are provided in details.Together,this protocol is simple,low-cost,and effective for neuronal activity detection by fiber photometry,which will hep neuroscience researchers to carry out fiunctional and behavioral study in vivo.
基金supported by the National Key Research and Development Program of China(Grant No.2017-YFD0500303)the National Natural Science Foundation of China(Grant Nos.31371106,91640105)+1 种基金the China Agriculture Research System(No.CARS-36)the Huazhong Agricultural University Scienti¯c and Technological Self-innovation Foundation(Program No.52204-13002).
文摘Traditionally,optical microscopy is used to visualize the morphological features of pathogenic bacteria,of which the features are further used for the detection and ident ification of the bacteria.However,due to the resolution limitation of conventional optical microscopy as well as the lack of standard pattern library for bacteria identification,the ffectiveness of this optical microscopy-based method is limited.Here,we reported a pilot study on a combined use of Structured Illumination Microscopy(SIM)with machine learning for rapid bacteria identification.After applying machine learning to the SIM image datasets from three model bacteria(including Escherichia coli,Mycobacterium smegmatis,and Pseudomonas aeruginosa),we obtained a classifcation accuracy of up to 98%.This study points out a promising possibility for rapid bacterial identification by morphological features.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12175131 and 11905133)the China Postdoctoral Science Foundation(Grant No.2021M692021)。
文摘Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed to investigate the transport properties and electric field distribution inside the MAPbI_(3) single crystal detector.Owing to the almost homogeneous electric field built inside the detector during pulsed bias ToF measurement,the free hole mobility can be directly calculated to be about 22 cm^(2)·V^(-1)·s^(-1),and the hole lifetime is around 6.5μs–17.5μs.Hence,the mobility-lifetime product can be derived to be 1.4×10^(-4)cm^(2)·V^(-1)–3.9×10^(-4)cm^(2)·V^(-1).The transit time measured under the DC bias deviates with increasing voltage compared with that under the pulsed bias,which arises mainly from the inhomogeneous electric field distribution inside the perovskite.The positive space charge density can then be deduced to increase from 3.1×10^(10)cm^(-3)to 6.89×10^(10)cm^(-3)in a bias range of 50 V–150 V.The ToF measurement can provide us with a facile way to accurately measure the transport properties of the perovskite single crystals,and is also helpful in obtaining a rough picture of the internal electric field distribution.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0301700)the National Natural Science Foundation of China(Grant Nos.61922074,11674300,61674132,11625419,and 11804327)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB24030601)the Anhui Initiative in Quantum Information Technologies,China(Grant No.AHY080000)。
文摘Conerent photon source is an important element that has been widely used in spectroscopy,imaging,detection,and teleportation in quantum optics.However,it is still a challenge to realize micro-scale coherent emitters in semiconductor systems.We report the observation of gain in a cavity-coupled GaAs double quantum dot system with a voltage bias across the device.By characterizing and analyzing the cavity responses to different quantum dot behaviors,we distinguish the microwave photon emission from the signal gain.This study provides a possibility to realize micro-scale amplifiers or coherent microwave photon sources in circuit quantum electrodynamics(cQED) hybrid systems.
基金Project supported by the National Key R&D Program of China(Grant No.2016YFA0301700)the National Natural Science Foundation of China(Grant Nos.11674300,61674132,11575172,and 11625419)the Fundamental Research Fund for the Central Universities,China
文摘Thirty years of effort in semiconductor quantum dots has resulted in significant developments in the control of spin quantum bits(qubits). The natural two-energy level of spin states provides a path toward quantum information processing. In particular, the experimental implementation of spin control with high fidelity provides the possibility of realizing quantum computing. In this review, we will discuss the basic elements of spin qubits in semiconductor quantum dots and summarize some important experiments that have demonstrated the direct manipulation of spin states with an applied electric field and/or magnetic field. The results of recent experiments on spin qubits reveal a bright future for quantum information processing.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0301700)the National Natural Science Foundation of China(Grant Nos.61674132,11674300,11575172,and 11625419)the Anhui Initiative in Quantum information Technologies,China(Grant No.AHY080000)
文摘We investigate the dephasing mechanisms induced by the charge noise and microwave heating effect acting on a graphene double quantum dot (DQD) capacitively coupled to a microwave resonator. The charge noise is obtained from DC transport current, and its contribution to dephasing is simultaneously determined by the amplitude response of the microwave resonator. A lowfrequency 1/f-type noise is demonstrated to be the dominant factor of the dephasing of graphene DQD. Furthermore, when the applied microwave power is larger than -90 dBm, the dephasing rate of graphene DQD increases rapidly with the increase of microwave power, and fluctuates slightly with the applied microwave power smaller than -90 dBm. Our results can be applied to suppress the impeditive influence on the dephasing of graphene-based devices associated with microwave input in the perspective investigations.
基金supported by the National Natural Science Foundation of China(grant numbers:82071077,81771057,and 81400477 to H.L.82181340279,82071110,and 81771066 to Z.C.)+1 种基金“the Fundamental Research Funds for the Central Universities”(no.2042021kf0197)“The Young Top-notch Talent Cultivation Program of Hubei Province”to H.L.
文摘Genome-wide association studies(GWASs) are the most widely used method to identify genetic risk loci associated with orofacial clefts(OFC). However, despite the increasing size of cohort, GWASs are still insufficient to detect all the heritability,suggesting there are more associations under the current stringent statistical threshold. In this study, we obtained an integrated epigenomic dataset based on the chromatin conformation of a human oral epithelial cell line(HIOEC) using RNA-seq, ATAC-seq,H3K27ac Ch IP-seq, and DLO Hi-C. Presumably, this epigenomic dataset could reveal the missing functional variants located in the oral epithelial cell active enhancers/promoters along with their risk target genes, despite relatively less-stringent statistical association with OFC. Taken a non-syndromic cleft palate only(NSCPO) GWAS data of the Chinese Han population as an example, 3664 SNPs that cannot reach the strict significance threshold were subjected to this functional identification pipeline.In total, 254 potential risk SNPs residing in active cis-regulatory elements interacting with 1 718 promoters of oral epitheliumexpressed genes were screened. Gapped k-mer machine learning based on enhancers interacting with epithelium-expressed genes along with in vivo and in vitro reporter assays were employed as functional validation. Among all the potential SNPs, we chose and confirmed that the risk alleles of rs560789 and rs174570 reduced the epithelial-specific enhancer activity by preventing the binding of transcription factors related to epithelial development. In summary, we established chromatin conformation datasets of human oral epithelial cells and provided a framework for testing and understanding how regulatory variants impart risk for clefts.
文摘This paper reviews the studies of using FTIR to investigate the components of aerosols produced in smog chamber experiments and collected in atmosphere. The fact that aerosols are mixture of small amount of countless individual compounds makes the analysis of aerosol constituents very challenging. Although a number of advanced instruments have been applied to the chemical characterization of aerosol components, the majority of aerosol components, particularly the organics, remain unknown. Being supplemental to the traditional quantitative instruments, FTIR has been recently used either individually or combining with other analytical instruments to characterize the components of aerosol particles. This paper aims to show how FTIR is applied to analysis of organic aerosols in current literature and to summarize the FTIR characteristic peak frequencies that are widely seen in the FTIR measurement of organic aerosols. It will be greatly helpful to researchers whose studies are focused on the analysis of aerosol components.
文摘Mesenchymal stem cells?(MSCs) have been shown to differentiate into liver cells in serum of part-resection liver, but it was hardly feasible in clinical use. Our studies revealed that MSCs could differentiate into hepatocyte-like cells in autologous serum after radiofrequency ablation (RFA) therapy of the liver tumor. Rabbits with liver tumor subsequently treated with RFA therapy. Serum was collected from those rabbits before RFA therapy and 72 hours after RFA therapy. MSCs were isolated from each rabbit’s bone marrow and cultured in DMEM medium containing the following different supplements: 30% fetal calf serum (FCS group), 30% rabbit autologous serum (AS group) or 30% autologous serum after RFA treatment of the liver tumor (ASRF group), observed by electron microscopy, flow cytometry, immunofluorescence. Seven days later, most of the spindle-shaped MSCs in the ASRF group transformed into polygon or round-shaped cells resembling hepatocytes, and the percentage in S/G2/M phase was higher than in the FCS or AS groups. Fourteen days later, slender microvilli, cell-cell junction structures and cholangiole emerged in the cells belonging to the ASRF group, the expression of albumin and CK18 was observed only in the differentiated cells from the ASRF group. These changes were not observed in the FCS group or the AS group. This study may provide a potential cell source and culture process for clinical application in liver injury treatment.