A Novel On-Site-Real-Time Method for Identifying Characteristic Parameters Using Ultrasonic Echo Groups and Neural Network

On-site and real-time non-destructive measurement of elastic constants for materials of a component in a in-service structure is a challenge due to structural complexities,such as ambiguous boundary,variable thickness,nonuniform material properties.This work develops for the first time a method that uses ultrasound echo groups and artificial neural network(ANN)for reliable on-site real-time identification of material parameters.The use of echo groups allows the use of lower frequencies,and hence more accommodative to structural complexity.To train the ANNs,a numerical model is established that is capable of computing the waveform of ultrasonic echo groups for any given set of material properties of a given structure.The waveform of an ultrasonic echo groups at an interest location on the surface the structure with material parameters varying in a predefined range are then computed using the numerical model.This results in a set of dataset for training the ANN model.Once the ANN is trained,the material parameters can be identified simultaneously using the actual measured echo waveform as input to the ANN.Intensive tests have been conducted both numerically and experimentally to evaluate the effectiveness and accuracy of the currently proposed method.The results show that the maximum identification error of numerical example is less than 2%,and the maximum identification error of experimental test is less than 7%.Compared with currently prevailing methods and equipment,the proposefy the density and thickness,in addition to the elastic constants.Moreover,the reliability and accuracy of inverse prediction is significantly improved.Thus,it has broad applications and enables real-time field measurements,which has not been fulfilled by any other available methods or equipment.

Pyrotinib is effective in both trastuzumab-sensitive and primary resistant HER2-positive breast tumors

Objective: Primary resistance to trastuzumab frequently occurs in human epidermal growth factor receptor 2(HER2)-positive(+) breast cancer patients and remains a clinical challenge. Pyrotinib is a novel tyrosine kinase inhibitor that has shown efficacy in the treatment of HER2+ breast cancer. However, the efficacy of pyrotinib in HER2+ breast cancer with primary trastuzumab resistance is unknown.Methods: HER2+ breast cancer cells sensitive or primarily resistant to trastuzumab were treated with trastuzumab, pyrotinib, or the combination. Cell proliferation, migration, invasion, and HER2 downstream signal pathways were analyzed. The effects of pyrotinib plus trastuzumab and pertuzumab plus trastuzumab were compared in breast cancer cells in vitro and a xenograft mouse model with primary resistance to trastuzumab.Results: Pyrotinib had a therapeutic effect on trastuzumab-sensitive HER2+ breast cancer cells by inhibiting phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT) and rat sarcoma virus(RAS)/rapidly accelerated fibrosarcoma(RAF)/mitogen-activated protein kinase(MAPK)/extracellular-signal regulated kinase(ERK)pathways. In primary trastuzumab-resistant cells, pyrotinib inhibited cell growth, migration, invasion, and HER2 downstream pathways, whereas trastuzumab had no effects. The combination with trastuzumab did not show increased effects compared with pyrotinib alone. Compared with pertuzumab plus trastuzumab, pyrotinib plus trastuzumab was more effective in inhibiting cell proliferation and HER2 downstream pathways in breast cancer cells and tumor growth in a trastuzumab-resistant HER2+ breast cancer xenograft model.Conclusions: Pyrotinib-containing treatments exhibited anti-cancer effects in HER2+ breast cancer cells sensitive and with primary resistance to trastuzumab. Notably, pyrotinib plus trastuzumab was more effective than trastuzumab plus pertuzumab in inhibiting tumor growth and HER2 downstream pathways in HER2+ breast cancer with primary resistance to trastuzumab. These findings support clinical testing of the therapeutic efficacy of dual anti-HER2 treatment combining an intracellular small molecule with an extracellular antibody.

Artificial intelligence efficiently predicts gastric lesions,Helicobacter pylori infection and lymph node metastasis upon endoscopic images

Objective:Medical images have been increased rapidly in digital medicine era,presenting an opportunity for the intervention of artificial intelligence(AI).In order to explore the value of convolutional neural network(CNN)algorithms in endoscopic images,we developed an AI-assisted comprehensive analysis system for endoscopic images and explored its performance in clinical real scenarios.Methods:A total of 6,270 white light endoscopic images from 516 cases were used to train 14 different CNN models.The images were divided into training set,validation set and test set according to 7:1:2 for exploring the possibility of discrimination of gastric cancer(GC)and benign lesions(nGC),gastric ulcer(GU)and ulcerated cancer(UCa),early gastric cancer(EGC)and nGC,infection of Helicobacter pylori(Hp)and no infection of Hp(noHp),as well as metastasis and no-metastasis at perigastric lymph nodes.Results:Among the 14 CNN models,EfficientNetB7 revealed the best performance on two-category of GC and nGC[accuracy:96.40%and area under the curve(AUC)=0.9959],GU and UCa(accuracy:90.84%and AUC=0.8155),EGC and nGC(accuracy:97.88%and AUC=0.9943),and Hp and noHp(accuracy:83.33%and AUC=0.9096).Whereas,InceptionV3 model showed better performance on predicting metastasis and nometastasis of perigastric lymph nodes for EGC(accuracy:79.44%and AUC=0.7181).In addition,the integrated analysis of endoscopic images and gross images of gastrectomy specimens was performed on 95 cases by EfficientNetB7 and RFB-SSD object detection model,resulting in 100%of predictive accuracy in EGC.Conclusions:Taken together,this study integrated image sources from endoscopic examination and gastrectomy of gastric tumors and incorporated the advantages of different CNN models.The AI-assisted diagnostic system will play an important role in the therapeutic decision-making of EGC.

Association between the frontoparietal network,clinical symptoms and treatment response in individuals with untreated anorexia nervosa

Background Anorexia nervosa(AN)has been characterised as a psychiatric disorder associated with increased control.Currently,it remains difficult to predict treatment response in patients with AN.Their cognitive abilities are known to be resistant to treatment.It has been established that the frontoparietal control network(FPCN)is the direct counterpart of the executive control network.Therefore,the resting-state brain activity of the FPCN may serve as a biomarker to predict treatment response in AN.Aims The study aimed to investigate the association between resting-state functional connectivity(RSFC)of the FPCN,clinical symptoms and treatment response in patients with AN.Methods In this case-control study,79 female patients with AN and no prior treatment from the Shanghai Mental Health Center and 40 matched healthy controls(HCs)were recruited from January 2015 to March 2022.All participants completed the Questionnaire Versionof the Eating Disorder Examination(version 6.0)to assess the severity of their eating disorder symptoms.Additionally,RSFC data were obtained from all participants at baseline by functional magnetic resonance imaging.Patients with AN underwent routine outpatient treatment at the 4th and 12th week,during which time their clinical symptoms were evaluated using the same measures as at baseline.Results Among the 79 patients,40 completed the 4-week follow-up and 35 completed the 12-week follow-up.The RSFC from the right posterior parietal cortex(PPC)and dorsolateral prefrontal cortex(diPFC)increased in 79 patients with AN vs 40 HCs after controlling for depression and anxiety symptoms.By multiple linear regression,the RSFC of the PPC to the inferior frontal gyrus was found to be a significant factor for self-reported eating disorder symptoms at baseline and the treatment response to cognitive preoccupations about eating and body image,after controlling for age,age of onset and body mass index.The RSFC in the dIPFC to the middle temporal gyrus and the superior frontal gyrus may be significant factors in the treatment response to binge eating and loss of control/overeating in patients with AN.Conclusions Alterations in RSFC in the FPCN appear to affect self-reported eating disorder symptoms and treatment response in patients with AN.Our findings offer new insight into the pathogenesis of AN and could promote early prevention and treatment.

A general synthesis of inorganic nanotubes as high-rate anode materials of sodium ion batteries

Ino rganic tubular materials have an exceptionally wide range of applications,yet developing a simple and universal method to controllably synthesize them remains challenging.In this work,we report a vaporphase-etching hard-template method that can directly fabricate tubes on various thermally stable oxide and sulfide materials.This synthesis method features the introduction of a vapor-phase-etching process to greatly simplify the steps involved in preparing tubular materials and avoids complicated postprocessing procedures.Furthermore,the in-situ heating transmission electron microscopy(TEM)technique is used to observe the dynamic formation process of TiO_(2-x) tubes,indicating that the removal process of the Sb2S3 templates first experienced the Rayleigh instability,then vapor-phase-etching process.When used as an anode for sodium ion batteries,the TiO_(2-x) tube exhibits excellent rate performance of134.6 mA h g^(-1) at the high current density of 10 A g^(-1) and long-term cycling over 7000 cycles.Moreover,the full cell demonstrates excellent cycling performance with capacity retention of 98%after 1000 cycles,indicating that it is a promising anode material for batteries.This method can be expanded to the design and synthesis of other thermally-stable tubular materials such as ZnS,MoS_(2),and SiO_(2).

High-entropy L1_(2)-Pt(FeCoNiCuZn)_(3) intermetallics for ultrastable oxygen reduction reaction

Enhancing the stability of Pt-based electrocatalysts for the sluggish cathodic oxygen reduction reaction(ORR)is critical for proton exchange membrane fuel cells(PEMFCs).Herein,high-entropy intermetallic(HEI)L1_(2)-Pt(FeCoNiCuZn)3is designed for durable ORR catalysis.Benefiting from the unique HEI structure and the enhanced intermetallic phase stability,Pt(FeCoNiCuZn)3/C nanoparticles demonstrate significantly improved stability over Pt/C and PtCu_(3)/C catalysts.The Pt(FeCoNiCuZn)3/C exhibits a negligible decay of the half-wave potential during 30,000 potential cycles from 0.6 to 1.0 V,whereas Pt/C and PtCu_(3)/C are negatively shifted by 46 and 36 m V,respectively.Even after 10,000 cycles at potential up to 1.5 V,the mass activity of Pt(FeCoNiCuZn)3/C still shows~70%retention.As evidenced by the structural characterizations,the HEI structure of Pt(FeCoNiCuZn)3/C is well maintained,while PtCu_(3)/C nanoparticles undergo severe Cu leaching and particle growth.In addition,when assembled Pt(FeCoNiCuZn)3/C as the cathode in high-temperature PEMFC of 160℃,the H_(2)-O_(2)fuel cell delivers almost no degradation even after operating for 150 h,demonstrating the potential for fuel cell applications.This work provides a facile design strategy for the development of high-performance ultrastable electrocatalysts.

Associations between parental support for physical activity and moderate-to-vigorous physical activity among Chinese school children： A cross-sectional study

Purpose: The objective of this study was to examine the associations between parental support for physical activity(PA) and levels of moderate-to-vigorous physical activity(MVPA) among Chinese school children.Methods: Study participants were 81,857 school-aged children(aged 9–17 years; mean age = 13 years; 49.0% boys) and their parents or guardians who took part in the 2016 Physical Activity and Fitness in China—The Youth Study project. The independent variables included various forms of parental support for PA ascertained through a survey completed by parents or guardians. The dependent variable was the children's average MVPA in minutes per day by self-report. Structure equation modeling was used to examine the associations between parental support for PA and children's MVPA minutes.Results: The overall mean for MVPA participation time for the child participants was 48.82 ± 28.71 min/day. Significant associations between various forms of parental support and MVPA among children were found. Parental encouragement, accompanying, financial support, involvement,and role modeling for PA were positively associated with a high level of student MVPA participation. Parental PA knowledge-sharing was not associated with MVPA. The patterns of the associations were similar across sex, residence locale(i.e., urban and rural), and school grades(primary,junior middle, and junior high schools).Conclusion: Findings from this study suggest that, among Chinese school children, parental support for PA is important in promoting and facilitating children's participation in MVPA.

Polyoxometalate-based electrolyte materials in redox flow batteries:Current trends and emerging opportunities

Redox flow batteries have received wide attention for electrochemical energy conversion and storage devices due to their specific advantage of uncoupled power and energy devices,and therefore potentially to reduce the capital costs of energy storage.Terrific structural features of polyoxometalates exhibit unique advantages in redox flow batteries,such as,stable chemical properties,multi-electron reaction,good redox reversibility,low permeability,etc,which furnishes a novel perspective for settling various problems of redox flow batteries.This was a comprehensive and critical review of this type of batteries,focusing mainly on the chemistry of polyoxometalate electrolyte materials and introducing a systematic classification.Finally,challenges and perspectives of polyoxometalate electrolyte materials and polyoxometalate redox flow batteries are discussed.

Towards wafer-scale growth of two-dimensional cerium dioxide single crystal with high dielectric performance

Owing to the atomically thin nature,two-dimensional(2D)oxide materials have been widely reported to exhibit exciting transport and dielectric properties,such as fine gate controllability and ultrahigh carrier mobility,that outperform their bulk counterpart.However,unlike the successful synthesis of bulk oxide single crystals,reliable methods for synthesizing large-area single crystal of 2D oxide,that would suppress the negative influence from defective grain boundaries,remain unavailable,especially for nonlayered oxide.Herein,we report that the lattice symmetry between the substrate and cerium dioxide(CeO_(2))would allow for the aligned nucleation and epitaxial growth of CeO_(2)on sapphire substrates,enabling the wafer-sized growth of CeO_(2)single crystal.The careful tuning of the growth temperature and oxygen flow rate contributed to the harvesting of CeO_(2)wafer with reduced thickness and enhanced growth rates.The removal of grain boundaries improved the dielectric performance in terms of high dielectric strength(E_(bd)≈8.8 MV·cm^(-1)),suppressed leakage current,along with high dielectric constants(ε_(r)≈24).Our work demonstrates that with fine dielectric performance and ease of synthesizing wafer-sized single crystals,CeO_(2)can function as potential candidate as gate insulator for 2D-materials based nanoelectronics,and we believe the reported protocol of aligned nucleation can be extended to other 2D oxides.

Hot-carrier engineering for two-dimensional integrated infrared optoelectronics

Plasmonic hot carrier engineering holds great promise for advanced infrared optoelectronic devices.The process of hot carrier transfer has the potential to surpass the spectral limitations of semiconductors,enabling detection of subbandgap infrared photons.By harvesting hot carriers prior to thermalization,energy dissipation is minimized,leading to highly efficient photoelectric conversion.Distinguished from conventional band-edge carriers,the ultrafast interfacial transfer and ballistic transport of hot carriers present unprecedented opportunities for high-speed photoelectric conversion.However,a complete description on the underlying mechanism of hot-carrier infrared optoelectronic device is still lacking,and the utilization of this strategy for tailoring infrared response is in its early stages.This review aims to provide a comprehensive overview of the generation,transfer and transport dynamics of hot carriers.Basic principles of hot-carrier conversion in heterostructures are discussed in detail.In addition,progresses of two-dimensional(2D)infrared hot-carrier optoelectronic devices are summarized,with a specific emphasis on photodetectors,solar cells,light-emitting devices and novel functionalities through hot-carrier engineering.Furthermore,challenges and prospects of hot-carrier device towards infrared applications are highlighted.

深圳文化馆新馆结构设计探讨

深圳文化馆新馆建筑造型复杂、内部空间变化较多,存在超过21 m的大悬挑空间。为确保整个结构具有合理的抗侧和抗扭刚度,在建筑楼梯、电梯间设置了8个钢筋混凝土筒体,这些筒体与周边框架柱形成框架剪力墙结构。但由于建筑内外空间上的变化和功能上的特殊要求,该结构存在较多的不规则项和复杂子结构。如文化馆典型楼层开洞率达32%以上,馆内各区域功能差异较大,区域之间仅通过室内连廊连接在一起,实际楼板情况与刚性楼板假定不符,此时如何评判结构的变形指标以及楼板协调变形的能力成为设计的一个重、难点;将文化馆划分为三个区域,分别为左侧、右侧核心筒群区域以及东侧大跨度钢结构区域,选取三个区域中的典型观测点,考察地震作用下观测点的变形,进一步判断楼板是否具有协调三个区域变形差异的能力。对大悬挑区域进行了方案对比阐述,同时对与悬挑桁架上弦相连的楼盖构件进行受力分析,讨论其在结构遭受罕遇地震作用、薄弱连接位置的楼板出现损坏引起楼板刚度退化甚至是完全退出工作时,能否保证桁架与核心筒之间的传力。东侧区域建筑功能要求大柱跨及楼层通高,典型柱距8.4 m×16.8 m,且仅可在L4~L8层布置钢柱,B1~L4层之间则须要设置Y型斜柱承托上部钢柱;分析Y型斜柱传递重力时其独立承担倾覆荷载的能力,同时Y型斜柱为3~4层的跃层柱,其能否满足稳定承载力和抗连续倒塌要求均为讨论的重、难点。在考察结构刚度指标(如层间位移角)时,可根据结构受力情况采取分区统计方式,捕捉关键监测点的变形值,综合评判楼盖协调变形的能力。对于室内连桥以及楼板薄弱连接位置,通过建立分离体模型进行包络设计,同时加强楼板配筋。通过在支承大悬挑桁架的剪力墙内设置型钢梁柱和斜杆的方式形成立体筒体,并充分考虑楼板刚度退化对大悬挑桁架与筒体之间构件的受力和变形影响,分析结果表明,大悬挑整体结构可满足各项验算。Y型斜柱独立承担倾覆荷载的能力较弱,设计时加强斜柱与核心筒群之间的楼盖连系,严格控制斜柱与核心筒之间拉梁的应力比。Y型斜柱设计时,应考虑构件的初始缺陷进行非线性稳定承载力分析,明确斜柱的稳定承载力储备。采用线性静力拆除构件法,可判断斜柱结构满足抗连续倒塌要求。选取典型的大悬挑桁架与剪力墙连接节点和型钢混凝土桁架转换节点作为研究对象,提出相应的节点加强构造,通过节点有限元分析,确保节点的安全可靠。

General strategy for evaluating the d-band center shift and ethanol oxidation reaction pathway towards Pt-based electrocatalysts

The catalytic performance of Pt-based catalysts depends sensitively on their d-band centers.Nevertheless,there are still huge challenges to evaluate their d-band centers from experimental technologies,and modulate them to analyze their selectivity in ethanol oxidation reaction(EOR).Here,Pt1Au1alloy supported on the commercial carbon material(Pt_(1)Au_(1)/C)is employed as a typical example to investigate its d-band center shift of surface Pt,and as electrocatalysts to study its selectivity towards EOR.Significantly,a highly reliable in situ Fourier-transform infrared spectroscopy CO-probe strategy is developed to characterize the d-band center shift of surface Pt.The modified electronic effect and site effect of Pt_(1)Au_(1)/C dictated the adsorption configuration of intermediate species and the OH species coverage,thereby influencing its selectivity.More importantly,we developed a universal cyclic voltammetry peak differentiation fitting method as an electrochemical analysis technique to investigate CO_(2)selectivity,which is potentially extendable to other Pt-based electrocatalysts.

Chromatin accessibility landscapes revealed the subgenome-divergent regulation networks during wheat grain development

Development of wheat(Triticum aestivum L.)grain mainly depends on the processes of starch synthesis and storage protein accumulation,which are critical for grain yield and quality.However,the regulatory network underlying the transcriptional and physiological changes of grain development is still not clear.Here,we combined ATAC-seq and RNA-seq to discover the chromatin accessibility and gene expression dynamics during these processes.We found that the chromatin accessibility changes are tightly associated with differential transcriptomic expressions,and the proportion of distal ACRs was increased gradually during grain development.Specific transcription factor(TF)binding sites were enriched at different stages and were diversified among the 3 subgenomes.We further predicted the potential interactions between key TFs and genes related with starch and storage protein biosynthesis and found different copies of some key TFs played diversified roles.Overall,our findings have provided numerous resources and illustrated the regulatory network during wheat grain development,which would shed light on the improvement of wheat yields and qualities.

Research on Teaching Reform of Basic Medical Courses in Comprehensive Universities Oriented Towards“Clinical Competency”

Through this study,we aim to construct a teaching model for basic medical courses that enhances“clinical competency.”We explore the optimal methods and pathways for the organic integration of exam-oriented teaching and professional teaching,optimize teaching efficiency,improve teaching quality and educational effectiveness,and provide theoretical support for the cultivation of clinical medical talents in China.The goal is to establish a talent cultivation objective oriented towards“clinical competency,”promote the teaching reform of basic medical courses in comprehensive universities,facilitate the transition of basic medical course teaching from“teacher knowledge presentation”to“student knowledge construction,”and cultivate high-quality medical talents with clinical competency.

叶面积指数田间测量中有限长度平均法的改进

叶面积指数(LAI)的田间测量是生态和农业等领域的常规工作之一,测量方法分为直接测量和间接测量,间接测量中有一类方法基于数字相机照片提取冠层孔隙率,再用有限长度平均法同时估算LAI和聚集指数。然而,有限长度平均法自提出以来缺少进一步的发展,在有限长度的样线/样方上应用比尔定律的方式具有理论缺陷,可能造成无效值或高估LAI。从模拟的训练数据中提取经验公式以取代比尔定律进行样线/样方的LAI估算,提高了有限长度平均法的精度和鲁棒性。进一步分析在一定精度需求下对样线/样方大小和数量的要求,对于非均匀样地,提出样线长度为8倍等效叶片边长、样方边长为3倍等效叶片边长的推荐设置。在基于数字相机照片提取非均匀样地LAI的应用中,使用样方采样比样线采样更为适宜。

Chinese expert consensus on conversion therapy for hepatocellular carcinoma(2021 edition)

Recent advances in systemic and locoregional treatments for patients with unresectable or advanced hepatocellular carcinoma(HCC)have resulted in improved response rates.This has provided an opportunity for selected patients with initially unresectable HCC to achieve adequate tumor downstaging to undergo surgical resection,a‘conversion therapy’strategy.However,conversion therapy is a new approach to the treatment of HCC and its practice and treatment protocols are still being developed.Review the evidence for conversion therapy in HCC and develop consensus statements to guide clinical practice.Evidence review:Many research centers in China have accumulated significant experience implementing HCC conversion therapy.Preliminary findings and data have shown that conversion therapy represents an important strategy to maximize the survival of selected patients with intermediate stage to advanced HCC;however,there are still many urgent clinical and scientific challenges for this therapeutic strategy and its related fields.In order to summarize and learn from past experience and review current challenges,the Chinese Expert Consensus on Conversion Therapy for Hepatocellular Carcinoma(2021 Edition)was developed based on a review of preliminary experience and clinical data from Chinese and non-Chinese studies in this field and combined with recommendations for clinical practice.Sixteen consensus statements on the implementation of conversion therapy for HCC were developed.The statements generated in this review are based on a review of clinical evidence and real clinical experience and will help guide future progress in conversion therapy for patients with HCC.

无权重物品的几乎无忌妒分配

公平分配研究如何把m个不可分的物品公平地分配给n个玩家.每个玩家关于物品有一个可加的估值函数.物品是无权重的,如果他们的取值范围为{1,0,-1}.非负估值的物品称为奖品,非正估值的物品称为苦差.本文考虑寻找无权重物品的分配,并满足“相差任意物品下是无忌妒的”(envy-free up to any item,EFX0).EFX;是本领域内最受关注的公平性度量.一般可加估值函数下的EFX;分配的存在性仍然是开放的.本文提出寻找无权重物品的EFX;分配的多项式时间算法.为了达到这个目的,本文分别提出了寻找无权重奖品和无权重苦差的EFX;分配的算法.然后,通过将二者小心地结合起来,本文得到了最终的算法.本文的结果完整刻画了无权重情况下寻找EFX;分配的解决方案.

Controlling phase transition in WSe_(2) towards ideal n-type transistor

Two-dimensional(2D)transition metal dichalcogenides(TMDs)have been rapidly established as promising building blocks for versatile atomic scale circuits and multifunctional devices.However,the high contact resistance in TMDs based transistors seriously hinders their applications in complementary electronics.In this work,we show that an Ohmic homojunction n-type tungsten diselenide(WSe_(2))transistor is realized through spatially controlling cesium(Cs)doping region near the contacts.We find that the remarkable electron doping effect of Cs stimulates a semiconductor to metal(2H to 1T')phase transition in WSe_(2),and hence the formation of 2H-1T’hetero-phase contact.Our method significantly optimizes the WSe_(2) transport behavior with a perfect low subthreshold swing of-61 mV/dec and ultrahigh current on/off ratio exceeding-10^(9).Meanwhile,the electron mobility is enhanced by nearly 50 times.We elucidate that the ideal n-type behavior originates from the negligible Schottky barrier height of~19 meV and low contact resistance of-0.9Ωk·μm in the 2H-1T’homojunction device.Moreover,based on the Ohmic hetero-phase configuration,a WSe_(2) inverter is achieved with a high gain of~270 and low power consumption of-28 pW.Our findings envision Cs functionalization as an effective method to realize ideal Ohmic contact in 2D WSe_(2) transistors towards high performance complementary electronic devices.

Speedup in classical simulation of Gaussian boson sampling

Gaussian boson sampling is an alternative model for demonstrating quantum computational supremacy,where squeezed states are injected into every input mode, instead of applying single photons as in the case of standard boson sampling. Here by analyzing numerically the computational costs, we establish a lower bound for achieving quantum computational supremacy for a class of Gaussian bosonsampling problems. Specifically, we propose a more efficient method for calculating the transition probabilities, leading to a significant reduction of the simulation costs. Particularly, our numerical results indicate that one can simulate up to 18 photons for Gaussian boson sampling at the output subspace on a normal laptop, 20 photons on a commercial workstation with 256 cores, and about 30 photons for supercomputers. These numbers are significantly smaller than those in standard boson sampling, suggesting that Gaussian boson sampling could be experimentally-friendly for demonstrating quantum computational supremacy.

Research on the autonomous system of the quadruped robot with a manipulator to realize leader-following,object recognition,navigation and operation

A systematic solution is developed to improve the autonomous capability of the quadruped robot with a manipulator,such as navigation,recognition and operation.The developed system adopts novel software,hardware system and system architecture,including a specially designed environment awareness system(EAS).Based on the camera and LiDAR on the EAS,the recognition of multiple common targets,such as the leader,door,window and bag,is achieved.In terms of navigation,a location method is built,that combines the laser odometer and global positioning system.A mapping and path planning module is designed by the Robot-centric Elevation Mapping algorithm and the rapidly exploring rand tree algorithm.For operation,a real-time target grasp detection system is proposed based on the You Only Look Once v5 algorithm to improve the success rate of tasks.The whole system is integrated based on the task relevance scheduling strategy to reduce the computational complexity.The tightly integrated system and the subsystems are evaluated by conducting simulations and physical experiments in robot recognition,navigation and operation.Extensive experiments show that the proposed framework can better achieve the autonomous navigation and operation of the quadruped robot with a manipulator.Notably,the proposed framework is still effective when facing dynamic objects.In addition,the system can be easily extended to other forms of mobile robot.