本研究采用不同的3种方法对绵羊基因组进行注释,筛选出适合绵羊转座元件注释的方法,并进行转座元件的演化历史分析。结果表明,采用从头预测(de novo prediction)和同源预测(homology?based prediction)相结合的策略对绵羊基因组进行注...本研究采用不同的3种方法对绵羊基因组进行注释,筛选出适合绵羊转座元件注释的方法,并进行转座元件的演化历史分析。结果表明,采用从头预测(de novo prediction)和同源预测(homology?based prediction)相结合的策略对绵羊基因组进行注释效果最佳,鉴定出绵羊基因组中转座元件占比为47.34%,其中长散布核元件(LINE)占比最高(35.34%),其余依次为长末端重复序列(LTR,5.43%)、短散布核元件(SINE,3.66%)、DNA转座元件(2.44%)和未知家族(0.56%)。LINE中的牛B型逆转录转座元件(RTE?BovB)占比达16.47%。转座元件在绵羊基因组中广泛分布,但在X染色体上富集显著,占比高达57.22%。研究通过Kimura双参数模型分析转座元件的演化历史,发现绵羊基因组经历了两次转座“爆发”事件:第1次以LINE转座元件为主,第2次则同时涉及LINE和SINE转座元件的扩增,且具有时序性。综上,LINE转座元件的持续活跃是绵羊基因组扩增的主要驱动力,且其演化历史与反刍动物的基因组进化密切相关。展开更多
To maintain the reliability of power systems,routine inspections using drones equipped with advanced object detection algorithms are essential for preempting power-related issues.The increasing resolution of drone-cap...To maintain the reliability of power systems,routine inspections using drones equipped with advanced object detection algorithms are essential for preempting power-related issues.The increasing resolution of drone-captured images has posed a challenge for traditional target detection methods,especially in identifying small objects in high-resolution images.This study presents an enhanced object detection algorithm based on the Faster Regionbased Convolutional Neural Network(Faster R-CNN)framework,specifically tailored for detecting small-scale electrical components like insulators,shock hammers,and screws in transmission line.The algorithm features an improved backbone network for Faster R-CNN,which significantly boosts the feature extraction network’s ability to detect fine details.The Region Proposal Network is optimized using a method of guided feature refinement(GFR),which achieves a balance between accuracy and speed.The incorporation of Generalized Intersection over Union(GIOU)and Region of Interest(ROI)Align further refines themodel’s accuracy.Experimental results demonstrate a notable improvement in mean Average Precision,reaching 89.3%,an 11.1%increase compared to the standard Faster R-CNN.This highlights the effectiveness of the proposed algorithm in identifying electrical components in high-resolution aerial images.展开更多
Microstrip transmission lines connecting to the millimeter wave radar chip and antenna significantly affect the radiation efficiency and bandwidth of the antenna.Here,a wideband non-uniform wavy microstrip line for co...Microstrip transmission lines connecting to the millimeter wave radar chip and antenna significantly affect the radiation efficiency and bandwidth of the antenna.Here,a wideband non-uniform wavy microstrip line for complex impedance in automotive radar frequency range is proposed.Unlike the gradient transmission line,the wavy structure is composed of periodically semi-circular segments.By adjusting the radius of the semi-circular,the surface current is varied and concentrated on the semi-circular segments,allowing a wider tunability range of the resonant frequency.The results reveal that the bandwidth of the loaded wavy transmission line antenna improves to 9.37 GHz,which is 5.81 GHz wider than that of the loaded gradient line.The gain and the half power beam width of the loaded antenna are about 14.69 dB and 9.58°,respectively.The proposed non-uniform microstrip line scheme may open up a route for realizing wideband millimeter-wave automotive radar applications.展开更多
This paper introduces a high-precision bandgap reference(BGR)designed for battery management systems(BMS),fea-turing an ultra-low temperature coefficient(TC)and line sensitivity(LS).The BGR employs a current-mode sche...This paper introduces a high-precision bandgap reference(BGR)designed for battery management systems(BMS),fea-turing an ultra-low temperature coefficient(TC)and line sensitivity(LS).The BGR employs a current-mode scheme with chopped op-amps and internal clock generators to eliminate op-amp offset.A low dropout regulator(LDO)and a pre-regula-tor enhance output driving and LS,respectively.Curvature compensation enhances the TC by addressing higher-order nonlinear-ity.These approaches,effective near room temperature,employs trimming at both 20 and 60°C.When combined with fixed cur-vature correction currents,it achieves an ultra-low TC for each chip.Implemented in a CMOS 180 nm process,the BGR occu-pies 0.548 mm²and operates at 2.5 V with 84μA current draw from a 5 V supply.An average TC of 2.69 ppm/℃ with two-point trimming and 0.81 ppm/℃ with multi-point trimming are achieved over the temperature range of-40 to 125℃.It accommo-dates a load current of 1 mA and an LS of 42 ppm/V,making it suitable for precise BMS applications.展开更多
This study investigates the mechanical response of an underground cavern subjected to cyclic high gas pressure,aiming to establish a theoretical foundation for the design of lined rock caverns(LRCs)for energy storage ...This study investigates the mechanical response of an underground cavern subjected to cyclic high gas pressure,aiming to establish a theoretical foundation for the design of lined rock caverns(LRCs)for energy storage with high internal pressure,e.g.compressed air energy storage(CAES)underground caverns or hydrogen storage caverns.Initially,the stress paths of the surrounding rock during the excavation,pressurization,and depressurization processes are delineated.Analytical expressions for the stress and deformation of the surrounding rock are derived based on the MohreCoulomb criterion.These expressions are then employed to evaluate the displacement of cavern walls under varying qualities of surrounding rock,the contact pressure between the steel lining and the surrounding rock subject to different gas storage pressures,the load-bearing ratio of the surrounding rock,and the impact of lining thickness on the critical gas pressure.Furthermore,the deformation paths of the surrounding rock are evaluated,along with the effects of tunnel depth and diameter on residual deformation of the surrounding rock,and the critical minimum gas pressure at which the surrounding rock and the lining do not detach.The results indicate that residual deformation of the surrounding rock occurs after depressurization under higher internal pressure for higher-quality rock masses,leading to detachment between the surrounding rock and the steel lining.The findings indicate that thicker linings correspond to higher critical minimum gas pressures.However,for lower-quality surrounding rock,thicker linings correspond to lower critical minimum gas pressures.These findings will provide invaluable insights for the design of LRCs for underground energy storage caverns.展开更多
In this paper,we prove that L(K_(x,y))(λ),theλ-fold line graph of the complete bipartite graph Ka,y,has a C_(6)-decomposition if and only if ry≥6,λxy(c+y-2)=0(mod 12)and(x+y)=0(mod 2),where x,y are nonnegative int...In this paper,we prove that L(K_(x,y))(λ),theλ-fold line graph of the complete bipartite graph Ka,y,has a C_(6)-decomposition if and only if ry≥6,λxy(c+y-2)=0(mod 12)and(x+y)=0(mod 2),where x,y are nonnegative integers and(x,y)≠(2,4)or(2,5).展开更多
In recent years,train-tail swaying of 160 km/h electric multiple units(EMUs)inside single-line tunnels has been heavily researched,because the issue needs to be solved urgently.In this paper,a co-simulation model of v...In recent years,train-tail swaying of 160 km/h electric multiple units(EMUs)inside single-line tunnels has been heavily researched,because the issue needs to be solved urgently.In this paper,a co-simulation model of vortex-induced vibration(VIV)of the tail car body is established,and the aerodynamics of train-tail swaying is studied.The simulation results were confirmed through a field test of operating EMUs.Furthermore,the influence mechanism of train-tail swaying on the wake flow field is studied in detail through a wind-tunnel experiment and a simulation of a reduced-scaled train model.The results demonstrate that the aerodynamic force frequency(i.e.,vortex-induced frequency)of the train tail increases linearly with train speed.When the train runs at 130 km/h,with a small amplitude of train-tail swaying(within 10 mm),the vortex-induced frequency is 1.7 Hz,which primarily depends on the nose shape of the train tail.After the tail car body nose is extended,the vortex-induced frequency is decreased.As the swaying amplitude of the train tail increases(exceeding 25 mm),the separation point of the high-intensity vortex in the train wake shifts downstream to the nose tip,and the vortex-induced frequency shifts from 1.7 Hz to the nearby car body hunting(i.e.,the primary hunting)frequency of 1.3 Hz,which leads to the frequency-locking phenomenon of VIV,and the resonance intensifies train-tail swaying.For the motor vehicle of the train tail,optimization of the yaw damper to improve its primary hunting stability can effectively alleviate train-tail swaying inside single-line tunnels.Optimization of the tail car body nose shape reduces the amplitude of the vortex-induced force,thereby weakening the aerodynamic effect and solving the problem of train-tail swaying inside the single-line tunnels.展开更多
In order to increase the stability of the Mongolia power system, a single-phase automatic reclosing device (SPAR) was introduced on double-circuit power lines built with a size of 330 kV, operating on a voltage of 220...In order to increase the stability of the Mongolia power system, a single-phase automatic reclosing device (SPAR) was introduced on double-circuit power lines built with a size of 330 kV, operating on a voltage of 220 kV and a length of 250 km. These overhead power lines (L-213, L-214) connect the 220/110/35 kV “Songino” substation with the “Mandal” substation and form system networks. This paper presents the challenges encountered when implementing single-phase automatic reclosing (SPAR) devices and compares the changes in power system parameters before and after SPAR deployment for a long 220 kV line. Simulations and analyses were carried out using DIgSILENT PowerFactory software, focusing on rotor angle stability, and the overall impact on the power system during short-circuit faults. The evaluation also utilized measurement data from the Wide Area Monitoring System (WAMS) to compare system behavior pre- and post-implementation of SPAR. The findings reveal that SPAR significantly enhances system reliability and stability, effectively mitigating the risk of oscillations and stability loss triggered by short circuits. This improvement contributes to a more resilient power system, reducing the potential for disturbances caused by faults.展开更多
Sea lines of communication(SLOCs)security has long been a strategic concern for major powers.Following the establishment of the People’s Republic of China,the country’s focus was on the traditional security aspects ...Sea lines of communication(SLOCs)security has long been a strategic concern for major powers.Following the establishment of the People’s Republic of China,the country’s focus was on the traditional security aspects of its SLOCs.Since the reform and opening-up era-and especially after the end of the Cold War-China has shifted its emphasis toward economic security.China’s SLOCs security bears on multiple dimensions of a holistic approach to national security,encompassing economic security,the safety of its citizens.展开更多
We report the fabrication of an 8-meter-long thin-flm lithium niobate optical true delay line using the photolithography-assisted chemomechanical etching technique,showing a low transmission loss of 0.036 dB/cm in the...We report the fabrication of an 8-meter-long thin-flm lithium niobate optical true delay line using the photolithography-assisted chemomechanical etching technique,showing a low transmission loss of 0.036 dB/cm in the conventional telecom band.展开更多
Background Transgenic research in crops involves using genetic engineering techniques to introduce specific genes of interest from other organisms,or even entirely new genes into plant genomes to create crops with des...Background Transgenic research in crops involves using genetic engineering techniques to introduce specific genes of interest from other organisms,or even entirely new genes into plant genomes to create crops with desirable traits that wouldn’t be possible through conventional breeding methods.Transgenic crops have been developed for various traits globally.Whitefly,Bemisia tabaci(Gennadius)is one of the major sucking pests of cotton that cause significant damage to the cotton production.To combat whitefly infestations,researchers have developed four transgenic cotton lines expressing the fern protein.And those transgenic lines need to be evaluated for their performance against the target pest—whitefly.The evaluation was designed as controlled trials in polyhouse or muslin cloth cages under open-choice and no-choice conditions by comparing four transgenic cotton lines(A,B,C,and D)with three control groups,including untransformed cotton plants with a same genetic background of the transgenic line,conventionally bred whitefly-resistant cotton,and whitefly-susceptible cotton.In order to study the generational effect,the evaluation also involved studies on whitefly development in laboratory,muslin cloth cage,and polyhouse conditions.Results Both open-choice and no-choice experiments had shown that all the four transgenic cotton lines(A,B,C,and D)expressing the fern protein reduced adult whitefly numbers significantly compared with the control lines,except for the no-choice conditions in 2021,where the transgenic line C was non-significant different from the resistant control line.Notably,the nymphal population on the resistant control line was relatively low and nonsignificant different from the transgenic line C in 2021;and the transgenic lines A and C in 2022 under open-choice conditions.Under no-choice condition,the nymphal counts in the resistant control line was non-significant different from transgenic lines C and D in 2021;and transgenic line D in 2022.All transgenic lines showed significant decrease in egg hatching in 2021 and nymphal development in 2022,except for the transgenic line C which had no significant different in the nymphal development comparing with non-transgenic control lines in 2022.Adult emergence rates in both years of evaluation showed significant decrease in transgenic lines A and B comparing with the control lines.Additionally,the results showed a significant reduction in cotton leaf curl disease and sooty mold development in all the four transgenic lines compared with susceptible control under open-choice conditions,indicating potential benefits of transgenic lines beyond direct effect on whitefly control.Furthermore,the research explored the generational effects of the fern protein on whitefly which revealed the lowest fecundity in the transgenic line C across F0,F1 and F3 generations,lower egg hatching in F1 and F2 generations in transgenic lines A and B,shorter nymphal duration in F1 and F2 generations in transgenic line B,and the least total adult emergence in the transgenic line C in F0 and F3 generations.Conclusions These findings suggest that the transgenic cotton lines expressing fern protein disrupts whitefly populations and the life cycle to a certain extent.However,results are not consistent over generations and years of study,indicating these transgenic lines were not superior over control lines and need to be improved in future breeding.展开更多
The study of multiple molecular spectral lines in gas infalling sources can provide the physical and chemica properties of these sources and help us estimate their evolutionary stages.We report line detections within ...The study of multiple molecular spectral lines in gas infalling sources can provide the physical and chemica properties of these sources and help us estimate their evolutionary stages.We report line detections within the 3 mm band using the FTS wide-sideband mode of the IRAM 30 m telescope toward 20 gas-infalling sources.Using XCLASS,we identify the emission lines of up to 22 molecular species(including a few isotopologues)and on hydrogen radio recombination line in these sources.H^(13)CO^(+),HCO^(+),HCN,HNC,c-C_(3)H_(2),and CCH lines are detected in 15 sources.We estimate the rotation temperatures and column densities of these molecular species using the LTE radiative transfer model,and compare the molecular abundances of these sources with those from nine high mass star-forming regions reported in previous studies and with those from the chemical model.Our results sugges that G012.79-0.20,G012.87-0.22 clump A and B,and G012.96-0.23 clump A may be in the high-mass protostella object stage,while sources with fewer detected species may be in the earlier evolutionary stage.Additionally,th CCH and c-C_(3)H_(2)column densities in our sources reveal a linear correlation,with a ratio of N(CCH)/N(c-C_(3)H_(2)=89.2±5.6),which is higher than the ratios reported in the literature.When considering only sources with lowe column densities,this ratio decreases to 29.0±6.1,consistent with those of diffuse clouds.Furthermore,comparison between the N(CCH)/N(c-C_(3)H_(2))ratio and the sources’physical parameters reveals a correlation,with sources exhibiting higher ratios tending to have higher kinetic temperatures and H2column densities.展开更多
The standing waves existing in radio telescope data are primarily due to reflections among the instruments,which significantly impact the spectral quality of the Five-hundred-meter Aperture Spherical radio Telescope(F...The standing waves existing in radio telescope data are primarily due to reflections among the instruments,which significantly impact the spectral quality of the Five-hundred-meter Aperture Spherical radio Telescope(FAST).Eliminating these standing waves for FAST is challenging given the constant changes in their phases and amplitudes.Over a ten-second period,the phases shift by 18°while the amplitudes fluctuate by 6 mK.Thus,we developed the fast Fourier transform(FFT)filter method to eliminate these standing waves for every individual spectrum.The FFT filter can decrease the rms from 3.2 to 1.15 times the theoretical estimate.Compared to other methods such as sine fitting and running median,the FFT filter achieves a median rms of approximately 1.2 times the theoretical expectation and the smallest scatter at 12%.Additionally,the FFT filter method avoids the flux loss issue encountered with some other methods.The FFT is also efficient in detecting harmonic radio frequency interference(RFI).In the FAST data,we identified three distinct types of harmonic RFI,each with amplitudes exceeding 100 mK and intrinsic frequency periods of 8.1,0.5,and 0.37 MHz,respectively.The FFT filter,proven as the most effective method,is integrated into the H I data calibration and imaging pipeline for FAST(HiFAST,https://hifast.readthedocs.io).展开更多
We consider large-time behaviors of weak solutions to the evolutionary p-Laplacian with logarithmic source of time-dependent coefficient.We find that the weak solutions may neither decay nor blow up,provided that the ...We consider large-time behaviors of weak solutions to the evolutionary p-Laplacian with logarithmic source of time-dependent coefficient.We find that the weak solutions may neither decay nor blow up,provided that the initial data u(·,t_(0))is on the Nehari manifold N:={v∈W_(0)^(1,p)(Ω):I(v,to)=0,||▽v||P^(P)≠0}.This is quite different from the known results that the weak solutions may blow up as,u(·,to)∈N^(+):={v∈W_(0)^(1,p)(Ω):I(v,t_(0))<0}and weak solutions may decay as u(·,t_(0))∈N^(+):={v∈W_(0)^(1,p)(Ω):I(v,t_(0))>0}.展开更多
In response to the deficiencies of commonly used optimization methods for assembly lines,a production demand-oriented optimization method for assembly lines is proposed.Taking a certain compressor assembly line as an ...In response to the deficiencies of commonly used optimization methods for assembly lines,a production demand-oriented optimization method for assembly lines is proposed.Taking a certain compressor assembly line as an example,the production rhythm and the number of workstations are calculated based on production requirements and working systems.With assembly rhythm and smoothing index as optimization goals,an improved particle swarm optimization algorithm is employed for process allocation.Subsequently,Flexsim simulation is used to analyze the assembly line.The final results show that after optimization using the improved particle swarm algorithm,the assembly line balance rate increased from 71.1%to 85.9%,and the assembly line smoothing index decreased from 47.4 to 29.8,significantly enhancing assembly efficiency.This demonstrates the effectiveness of the proposed optimization method for the assembly line and provides a reference for other products in the same industry.展开更多
Efficient three-dimensional(3D)building reconstruction from drone imagery often faces data acquisition,storage,and computational challenges because of its reliance on dense point clouds.In this study,we introduced a n...Efficient three-dimensional(3D)building reconstruction from drone imagery often faces data acquisition,storage,and computational challenges because of its reliance on dense point clouds.In this study,we introduced a novel method for efficient and lightweight 3D building reconstruction from drone imagery using line clouds and sparse point clouds.Our approach eliminates the need to generate dense point clouds,and thus significantly reduces the computational burden by reconstructing 3D models directly from sparse data.We addressed the limitations of line clouds for plane detection and reconstruction by using a new algorithm.This algorithm projects 3D line clouds onto a 2D plane,clusters the projections to identify potential planes,and refines them using sparse point clouds to ensure an accurate and efficient model reconstruction.Extensive qualitative and quantitative experiments demonstrated the effectiveness of our method,demonstrating its superiority over existing techniques in terms of simplicity and efficiency.展开更多
Manuscript Text and figures combined into a single file with page and line numbers up to3 MB in size in txt,doc,docx or tex files.Prepares your manuscript in the following order:Title page,Abstract,Introduction,Materi...Manuscript Text and figures combined into a single file with page and line numbers up to3 MB in size in txt,doc,docx or tex files.Prepares your manuscript in the following order:Title page,Abstract,Introduction,Materials and Methods,Results,Discussion,Acknowledgments,References,Tables,Figure Legends and Figures.Provide Cover letter and Supplementary Material(if necessary)at the same time.展开更多
The published article titled“Puerarin inhibits proliferation and induces apoptosis by upregulation of miR-16 in bladder cancer cell line T24”has been retracted from Oncology Research,Vol.26,No.8,2018,pp.1227–1234.
The lined rock cavern(LRC)compressed air energy storage(CAES)system is currently regarded as one of the most promising methods for large-scale energy storage.However,the safety of LRC under high internal pressure has ...The lined rock cavern(LRC)compressed air energy storage(CAES)system is currently regarded as one of the most promising methods for large-scale energy storage.However,the safety of LRC under high internal pressure has emerged as a critical issue that restricts their development.While scholars have focused on the safety of LRC under multiphysics field coupling,few have noticed the inevitable damage sustained by the primary load-bearing components—the surrounding rock and concrete lining—under high internal pressure,compromising their strength and permeation resistance.This study investigates the impact of damage to the surrounding rock and lining concrete on the stability and airtightness of the CAES cavern.First,a damagepermeability evolution model was established by analyzing cyclic loading and unloading test data on concrete samples.Then,a thermo-hydro-mechanical damage(THM-D)coupling model for the CAES cavern was developed and validated against operational data from the Huntorf plant.The coupling responses of both the surrounding rock and lining were compared and analyzed under three different schemes of the first charging and discharging operation.The results revealed the correlation between the air temperature in the cavern and the injection rate and the uneven damage evolution of the surrounding rock and lining caused by the geostress distribution coupled with the heat transfer process.Through the analysis,a higher air injection rate causes more lining damage and air leakage,posing greater risks to engineering safety and airtightness.However,the reduction of inflation time will weaken this effect to some extent.These findings offer valuable insights into the design,construction,and safe operation of LRC compressed air energy storage systems.展开更多
文摘本研究采用不同的3种方法对绵羊基因组进行注释,筛选出适合绵羊转座元件注释的方法,并进行转座元件的演化历史分析。结果表明,采用从头预测(de novo prediction)和同源预测(homology?based prediction)相结合的策略对绵羊基因组进行注释效果最佳,鉴定出绵羊基因组中转座元件占比为47.34%,其中长散布核元件(LINE)占比最高(35.34%),其余依次为长末端重复序列(LTR,5.43%)、短散布核元件(SINE,3.66%)、DNA转座元件(2.44%)和未知家族(0.56%)。LINE中的牛B型逆转录转座元件(RTE?BovB)占比达16.47%。转座元件在绵羊基因组中广泛分布,但在X染色体上富集显著,占比高达57.22%。研究通过Kimura双参数模型分析转座元件的演化历史,发现绵羊基因组经历了两次转座“爆发”事件:第1次以LINE转座元件为主,第2次则同时涉及LINE和SINE转座元件的扩增,且具有时序性。综上,LINE转座元件的持续活跃是绵羊基因组扩增的主要驱动力,且其演化历史与反刍动物的基因组进化密切相关。
基金supported by the Shanghai Science and Technology Innovation Action Plan High-Tech Field Project(Grant No.22511100601)for the year 2022 and Technology Development Fund for People’s Livelihood Research(Research on Transmission Line Deep Foundation Pit Environmental Situation Awareness System Based on Multi-Source Data).
文摘To maintain the reliability of power systems,routine inspections using drones equipped with advanced object detection algorithms are essential for preempting power-related issues.The increasing resolution of drone-captured images has posed a challenge for traditional target detection methods,especially in identifying small objects in high-resolution images.This study presents an enhanced object detection algorithm based on the Faster Regionbased Convolutional Neural Network(Faster R-CNN)framework,specifically tailored for detecting small-scale electrical components like insulators,shock hammers,and screws in transmission line.The algorithm features an improved backbone network for Faster R-CNN,which significantly boosts the feature extraction network’s ability to detect fine details.The Region Proposal Network is optimized using a method of guided feature refinement(GFR),which achieves a balance between accuracy and speed.The incorporation of Generalized Intersection over Union(GIOU)and Region of Interest(ROI)Align further refines themodel’s accuracy.Experimental results demonstrate a notable improvement in mean Average Precision,reaching 89.3%,an 11.1%increase compared to the standard Faster R-CNN.This highlights the effectiveness of the proposed algorithm in identifying electrical components in high-resolution aerial images.
基金Supported by the National Natural Science Foundation of China( 61974104)。
文摘Microstrip transmission lines connecting to the millimeter wave radar chip and antenna significantly affect the radiation efficiency and bandwidth of the antenna.Here,a wideband non-uniform wavy microstrip line for complex impedance in automotive radar frequency range is proposed.Unlike the gradient transmission line,the wavy structure is composed of periodically semi-circular segments.By adjusting the radius of the semi-circular,the surface current is varied and concentrated on the semi-circular segments,allowing a wider tunability range of the resonant frequency.The results reveal that the bandwidth of the loaded wavy transmission line antenna improves to 9.37 GHz,which is 5.81 GHz wider than that of the loaded gradient line.The gain and the half power beam width of the loaded antenna are about 14.69 dB and 9.58°,respectively.The proposed non-uniform microstrip line scheme may open up a route for realizing wideband millimeter-wave automotive radar applications.
基金supported by the National Natural Science Foundation of China(NSFC)under grant No.62204235。
文摘This paper introduces a high-precision bandgap reference(BGR)designed for battery management systems(BMS),fea-turing an ultra-low temperature coefficient(TC)and line sensitivity(LS).The BGR employs a current-mode scheme with chopped op-amps and internal clock generators to eliminate op-amp offset.A low dropout regulator(LDO)and a pre-regula-tor enhance output driving and LS,respectively.Curvature compensation enhances the TC by addressing higher-order nonlinear-ity.These approaches,effective near room temperature,employs trimming at both 20 and 60°C.When combined with fixed cur-vature correction currents,it achieves an ultra-low TC for each chip.Implemented in a CMOS 180 nm process,the BGR occu-pies 0.548 mm²and operates at 2.5 V with 84μA current draw from a 5 V supply.An average TC of 2.69 ppm/℃ with two-point trimming and 0.81 ppm/℃ with multi-point trimming are achieved over the temperature range of-40 to 125℃.It accommo-dates a load current of 1 mA and an LS of 42 ppm/V,making it suitable for precise BMS applications.
基金supported by the State Key Laboratory of Disaster Reduction in Civil Engineering(Grant No.SLDRCE23-02)Ningbo PublicWelfare Fund Project(Grant No.2023S100)the National Key Research and Development Program of China(Grant No.2024YFE0105800).
文摘This study investigates the mechanical response of an underground cavern subjected to cyclic high gas pressure,aiming to establish a theoretical foundation for the design of lined rock caverns(LRCs)for energy storage with high internal pressure,e.g.compressed air energy storage(CAES)underground caverns or hydrogen storage caverns.Initially,the stress paths of the surrounding rock during the excavation,pressurization,and depressurization processes are delineated.Analytical expressions for the stress and deformation of the surrounding rock are derived based on the MohreCoulomb criterion.These expressions are then employed to evaluate the displacement of cavern walls under varying qualities of surrounding rock,the contact pressure between the steel lining and the surrounding rock subject to different gas storage pressures,the load-bearing ratio of the surrounding rock,and the impact of lining thickness on the critical gas pressure.Furthermore,the deformation paths of the surrounding rock are evaluated,along with the effects of tunnel depth and diameter on residual deformation of the surrounding rock,and the critical minimum gas pressure at which the surrounding rock and the lining do not detach.The results indicate that residual deformation of the surrounding rock occurs after depressurization under higher internal pressure for higher-quality rock masses,leading to detachment between the surrounding rock and the steel lining.The findings indicate that thicker linings correspond to higher critical minimum gas pressures.However,for lower-quality surrounding rock,thicker linings correspond to lower critical minimum gas pressures.These findings will provide invaluable insights for the design of LRCs for underground energy storage caverns.
文摘In this paper,we prove that L(K_(x,y))(λ),theλ-fold line graph of the complete bipartite graph Ka,y,has a C_(6)-decomposition if and only if ry≥6,λxy(c+y-2)=0(mod 12)and(x+y)=0(mod 2),where x,y are nonnegative integers and(x,y)≠(2,4)or(2,5).
基金supported by the National Natural Science Foundation of China(Nos.52372403 and U2268211)the Natural Science Foundation of Sichuan Province(No.2022NSFSC0034),China+1 种基金the National Railway Group Science and Technology Program(No.2023J071)the Traction Power State Key Laboratory of the Independent Research and Development Projects(No.2022TPL-T02),China.
文摘In recent years,train-tail swaying of 160 km/h electric multiple units(EMUs)inside single-line tunnels has been heavily researched,because the issue needs to be solved urgently.In this paper,a co-simulation model of vortex-induced vibration(VIV)of the tail car body is established,and the aerodynamics of train-tail swaying is studied.The simulation results were confirmed through a field test of operating EMUs.Furthermore,the influence mechanism of train-tail swaying on the wake flow field is studied in detail through a wind-tunnel experiment and a simulation of a reduced-scaled train model.The results demonstrate that the aerodynamic force frequency(i.e.,vortex-induced frequency)of the train tail increases linearly with train speed.When the train runs at 130 km/h,with a small amplitude of train-tail swaying(within 10 mm),the vortex-induced frequency is 1.7 Hz,which primarily depends on the nose shape of the train tail.After the tail car body nose is extended,the vortex-induced frequency is decreased.As the swaying amplitude of the train tail increases(exceeding 25 mm),the separation point of the high-intensity vortex in the train wake shifts downstream to the nose tip,and the vortex-induced frequency shifts from 1.7 Hz to the nearby car body hunting(i.e.,the primary hunting)frequency of 1.3 Hz,which leads to the frequency-locking phenomenon of VIV,and the resonance intensifies train-tail swaying.For the motor vehicle of the train tail,optimization of the yaw damper to improve its primary hunting stability can effectively alleviate train-tail swaying inside single-line tunnels.Optimization of the tail car body nose shape reduces the amplitude of the vortex-induced force,thereby weakening the aerodynamic effect and solving the problem of train-tail swaying inside the single-line tunnels.
文摘In order to increase the stability of the Mongolia power system, a single-phase automatic reclosing device (SPAR) was introduced on double-circuit power lines built with a size of 330 kV, operating on a voltage of 220 kV and a length of 250 km. These overhead power lines (L-213, L-214) connect the 220/110/35 kV “Songino” substation with the “Mandal” substation and form system networks. This paper presents the challenges encountered when implementing single-phase automatic reclosing (SPAR) devices and compares the changes in power system parameters before and after SPAR deployment for a long 220 kV line. Simulations and analyses were carried out using DIgSILENT PowerFactory software, focusing on rotor angle stability, and the overall impact on the power system during short-circuit faults. The evaluation also utilized measurement data from the Wide Area Monitoring System (WAMS) to compare system behavior pre- and post-implementation of SPAR. The findings reveal that SPAR significantly enhances system reliability and stability, effectively mitigating the risk of oscillations and stability loss triggered by short circuits. This improvement contributes to a more resilient power system, reducing the potential for disturbances caused by faults.
文摘Sea lines of communication(SLOCs)security has long been a strategic concern for major powers.Following the establishment of the People’s Republic of China,the country’s focus was on the traditional security aspects of its SLOCs.Since the reform and opening-up era-and especially after the end of the Cold War-China has shifted its emphasis toward economic security.China’s SLOCs security bears on multiple dimensions of a holistic approach to national security,encompassing economic security,the safety of its citizens.
基金supported by the National Natural Science Foundation of China(Grant Nos.12192251,12334014,92480001,12134001,12304418,12274130,12274133,12474378,and 12404378)the National Key R&D Program of China(Grant Nos.2022YFA1404600 and 2022YFA1205100)+2 种基金Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301403)the Engineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(Grant No.2023nmc005)。
文摘We report the fabrication of an 8-meter-long thin-flm lithium niobate optical true delay line using the photolithography-assisted chemomechanical etching technique,showing a low transmission loss of 0.036 dB/cm in the conventional telecom band.
文摘Background Transgenic research in crops involves using genetic engineering techniques to introduce specific genes of interest from other organisms,or even entirely new genes into plant genomes to create crops with desirable traits that wouldn’t be possible through conventional breeding methods.Transgenic crops have been developed for various traits globally.Whitefly,Bemisia tabaci(Gennadius)is one of the major sucking pests of cotton that cause significant damage to the cotton production.To combat whitefly infestations,researchers have developed four transgenic cotton lines expressing the fern protein.And those transgenic lines need to be evaluated for their performance against the target pest—whitefly.The evaluation was designed as controlled trials in polyhouse or muslin cloth cages under open-choice and no-choice conditions by comparing four transgenic cotton lines(A,B,C,and D)with three control groups,including untransformed cotton plants with a same genetic background of the transgenic line,conventionally bred whitefly-resistant cotton,and whitefly-susceptible cotton.In order to study the generational effect,the evaluation also involved studies on whitefly development in laboratory,muslin cloth cage,and polyhouse conditions.Results Both open-choice and no-choice experiments had shown that all the four transgenic cotton lines(A,B,C,and D)expressing the fern protein reduced adult whitefly numbers significantly compared with the control lines,except for the no-choice conditions in 2021,where the transgenic line C was non-significant different from the resistant control line.Notably,the nymphal population on the resistant control line was relatively low and nonsignificant different from the transgenic line C in 2021;and the transgenic lines A and C in 2022 under open-choice conditions.Under no-choice condition,the nymphal counts in the resistant control line was non-significant different from transgenic lines C and D in 2021;and transgenic line D in 2022.All transgenic lines showed significant decrease in egg hatching in 2021 and nymphal development in 2022,except for the transgenic line C which had no significant different in the nymphal development comparing with non-transgenic control lines in 2022.Adult emergence rates in both years of evaluation showed significant decrease in transgenic lines A and B comparing with the control lines.Additionally,the results showed a significant reduction in cotton leaf curl disease and sooty mold development in all the four transgenic lines compared with susceptible control under open-choice conditions,indicating potential benefits of transgenic lines beyond direct effect on whitefly control.Furthermore,the research explored the generational effects of the fern protein on whitefly which revealed the lowest fecundity in the transgenic line C across F0,F1 and F3 generations,lower egg hatching in F1 and F2 generations in transgenic lines A and B,shorter nymphal duration in F1 and F2 generations in transgenic line B,and the least total adult emergence in the transgenic line C in F0 and F3 generations.Conclusions These findings suggest that the transgenic cotton lines expressing fern protein disrupts whitefly populations and the life cycle to a certain extent.However,results are not consistent over generations and years of study,indicating these transgenic lines were not superior over control lines and need to be improved in future breeding.
基金supported by the National Key R&D Program of China(No.2022YFA1603102)the National Natural Science Foundation of China(NSFC,Grant Nos.U2031202,12373030,and 11873093)。
文摘The study of multiple molecular spectral lines in gas infalling sources can provide the physical and chemica properties of these sources and help us estimate their evolutionary stages.We report line detections within the 3 mm band using the FTS wide-sideband mode of the IRAM 30 m telescope toward 20 gas-infalling sources.Using XCLASS,we identify the emission lines of up to 22 molecular species(including a few isotopologues)and on hydrogen radio recombination line in these sources.H^(13)CO^(+),HCO^(+),HCN,HNC,c-C_(3)H_(2),and CCH lines are detected in 15 sources.We estimate the rotation temperatures and column densities of these molecular species using the LTE radiative transfer model,and compare the molecular abundances of these sources with those from nine high mass star-forming regions reported in previous studies and with those from the chemical model.Our results sugges that G012.79-0.20,G012.87-0.22 clump A and B,and G012.96-0.23 clump A may be in the high-mass protostella object stage,while sources with fewer detected species may be in the earlier evolutionary stage.Additionally,th CCH and c-C_(3)H_(2)column densities in our sources reveal a linear correlation,with a ratio of N(CCH)/N(c-C_(3)H_(2)=89.2±5.6),which is higher than the ratios reported in the literature.When considering only sources with lowe column densities,this ratio decreases to 29.0±6.1,consistent with those of diffuse clouds.Furthermore,comparison between the N(CCH)/N(c-C_(3)H_(2))ratio and the sources’physical parameters reveals a correlation,with sources exhibiting higher ratios tending to have higher kinetic temperatures and H2column densities.
基金supported by the China National Key Program for Science and Technology Research and Development of China (2022YFA1602901,2023YFA1608204)the National SKA Program of China (No.2022SKA0110201)+5 种基金the National Natural Science Foundation of China (NSFC,grant Nos.11873051,11988101,12033008,12041305,12125302,12173016,and 12203065)the CAS Project for Young Scientists in Basic Research grant (No.YSBR-062)the K.C.Wong Education Foundationthe science research grants from the China Manned Space Projectsupport from the Cultivation Project for FAST Scientific Payoff and Research Achievement of CAMS-CASsupported by the China Postdoctoral Science Foundation grant No.2024M763213
文摘The standing waves existing in radio telescope data are primarily due to reflections among the instruments,which significantly impact the spectral quality of the Five-hundred-meter Aperture Spherical radio Telescope(FAST).Eliminating these standing waves for FAST is challenging given the constant changes in their phases and amplitudes.Over a ten-second period,the phases shift by 18°while the amplitudes fluctuate by 6 mK.Thus,we developed the fast Fourier transform(FFT)filter method to eliminate these standing waves for every individual spectrum.The FFT filter can decrease the rms from 3.2 to 1.15 times the theoretical estimate.Compared to other methods such as sine fitting and running median,the FFT filter achieves a median rms of approximately 1.2 times the theoretical expectation and the smallest scatter at 12%.Additionally,the FFT filter method avoids the flux loss issue encountered with some other methods.The FFT is also efficient in detecting harmonic radio frequency interference(RFI).In the FAST data,we identified three distinct types of harmonic RFI,each with amplitudes exceeding 100 mK and intrinsic frequency periods of 8.1,0.5,and 0.37 MHz,respectively.The FFT filter,proven as the most effective method,is integrated into the H I data calibration and imaging pipeline for FAST(HiFAST,https://hifast.readthedocs.io).
文摘We consider large-time behaviors of weak solutions to the evolutionary p-Laplacian with logarithmic source of time-dependent coefficient.We find that the weak solutions may neither decay nor blow up,provided that the initial data u(·,t_(0))is on the Nehari manifold N:={v∈W_(0)^(1,p)(Ω):I(v,to)=0,||▽v||P^(P)≠0}.This is quite different from the known results that the weak solutions may blow up as,u(·,to)∈N^(+):={v∈W_(0)^(1,p)(Ω):I(v,t_(0))<0}and weak solutions may decay as u(·,t_(0))∈N^(+):={v∈W_(0)^(1,p)(Ω):I(v,t_(0))>0}.
文摘In response to the deficiencies of commonly used optimization methods for assembly lines,a production demand-oriented optimization method for assembly lines is proposed.Taking a certain compressor assembly line as an example,the production rhythm and the number of workstations are calculated based on production requirements and working systems.With assembly rhythm and smoothing index as optimization goals,an improved particle swarm optimization algorithm is employed for process allocation.Subsequently,Flexsim simulation is used to analyze the assembly line.The final results show that after optimization using the improved particle swarm algorithm,the assembly line balance rate increased from 71.1%to 85.9%,and the assembly line smoothing index decreased from 47.4 to 29.8,significantly enhancing assembly efficiency.This demonstrates the effectiveness of the proposed optimization method for the assembly line and provides a reference for other products in the same industry.
基金Supported by the Guangdong Major Project of Basic and Applied Basic Research (2023B0303000016)the National Natural Science Foundation of China (U21A20515)。
文摘Efficient three-dimensional(3D)building reconstruction from drone imagery often faces data acquisition,storage,and computational challenges because of its reliance on dense point clouds.In this study,we introduced a novel method for efficient and lightweight 3D building reconstruction from drone imagery using line clouds and sparse point clouds.Our approach eliminates the need to generate dense point clouds,and thus significantly reduces the computational burden by reconstructing 3D models directly from sparse data.We addressed the limitations of line clouds for plane detection and reconstruction by using a new algorithm.This algorithm projects 3D line clouds onto a 2D plane,clusters the projections to identify potential planes,and refines them using sparse point clouds to ensure an accurate and efficient model reconstruction.Extensive qualitative and quantitative experiments demonstrated the effectiveness of our method,demonstrating its superiority over existing techniques in terms of simplicity and efficiency.
文摘Manuscript Text and figures combined into a single file with page and line numbers up to3 MB in size in txt,doc,docx or tex files.Prepares your manuscript in the following order:Title page,Abstract,Introduction,Materials and Methods,Results,Discussion,Acknowledgments,References,Tables,Figure Legends and Figures.Provide Cover letter and Supplementary Material(if necessary)at the same time.
文摘The published article titled“Puerarin inhibits proliferation and induces apoptosis by upregulation of miR-16 in bladder cancer cell line T24”has been retracted from Oncology Research,Vol.26,No.8,2018,pp.1227–1234.
基金National Natural Science Foundation of China,Grant/Award Number:U23B20147Key Research Program of Frontier Sciences,Chinese Academy of Sciences(CAS),Grant/Award Number:ZDBS-LY-DQC022+1 种基金Hubei Provincial Natural Science Foundation of China,Grant/Award Number:2023AFB346Knowledge Innovation Program of Wuhan-Shuguang Project,Grant/Award Number:2023010201020278。
文摘The lined rock cavern(LRC)compressed air energy storage(CAES)system is currently regarded as one of the most promising methods for large-scale energy storage.However,the safety of LRC under high internal pressure has emerged as a critical issue that restricts their development.While scholars have focused on the safety of LRC under multiphysics field coupling,few have noticed the inevitable damage sustained by the primary load-bearing components—the surrounding rock and concrete lining—under high internal pressure,compromising their strength and permeation resistance.This study investigates the impact of damage to the surrounding rock and lining concrete on the stability and airtightness of the CAES cavern.First,a damagepermeability evolution model was established by analyzing cyclic loading and unloading test data on concrete samples.Then,a thermo-hydro-mechanical damage(THM-D)coupling model for the CAES cavern was developed and validated against operational data from the Huntorf plant.The coupling responses of both the surrounding rock and lining were compared and analyzed under three different schemes of the first charging and discharging operation.The results revealed the correlation between the air temperature in the cavern and the injection rate and the uneven damage evolution of the surrounding rock and lining caused by the geostress distribution coupled with the heat transfer process.Through the analysis,a higher air injection rate causes more lining damage and air leakage,posing greater risks to engineering safety and airtightness.However,the reduction of inflation time will weaken this effect to some extent.These findings offer valuable insights into the design,construction,and safe operation of LRC compressed air energy storage systems.
