Event-triggered H_(∞) PI state estimation for delayed switched neural networks

On state estimation problems of switched neural networks,most existing results with an event-triggered scheme(ETS)not only ignore the estimator information,but also just employ a fixed triggering threshold,and the estimation error cannot be guaranteed to converge to zero.In addition,the state estimator of non-switched neural networks with integral and exponentially convergent terms cannot be used to improve the estimation performance of switched neural networks due to the difficulties caused by the nonsmoothness of the considered Lyapunov function at the switching instants.In this paper,we aim at overcoming such difficulties and filling in the gaps,by proposing a novel adaptive ETS(AETS)to design an event-based H_(∞)switched proportional-integral(PI)state estimator.A triggering-dependent exponential convergence term and an integral term are introduced into the switched PI state estimator.The relationship among the average dwell time,the AETS and the PI state estimator are established by the triggering-dependent exponential convergence term such that estimation error asymptotically converges to zero with H_(∞)performance level.It is shown that the convergence rate of the resultant error system can be adaptively adjusted according to triggering signals.Finally,the validity of the proposed theoretical results is verified through two illustrative examples.

Consensus of second-order nonlinear multi-agent systems via sliding mode observer and controller

This paper investigates the consensus problem of second-order nonlinear multi-agent systems (MASs) via the sliding mode control (SMC) approach. The velocity of each agent is assumed to be unmeasurable. A second-order sliding mode observer is designed to estimate the velocity. Then a distributed discontinuous control law based on first-order SMC is presented to solve the consensus problem. Moreover, to overcome the chatting problem, two controllers based on the boundary layer method and the super-twisting algorithm respectively are presented. It is shown that the MASs will achieve consensus under some given conditions. Some examples are provided to demonstrate the effectiveness of the proposed control laws.

基于“课程思政”的基础力学教学实践思考

发挥课堂教学在大学生思想政治教育中的主渠道作用,注重挖掘和运用各学科所蕴含的思想政治教育资源,引导大学生树立正确的世界观、人生观和价值观,是我们党在新时代关于“培养什么样的人、如何培养人以及为谁培养人”这个根本问题上对高校加强和改进思想政治教育和人才培养的新定位、新要求、新任务。本文以基础力学教学为依托,阐述了可以通过哪些渠道融入课程思政元素并基于此应着力培养哪些能力以及提升哪些素质。本文的观点同样适合于除了基础力学之外的其他课程的“课程思政”;不仅适合本科生教学的“课程思政”也适合于研究生教学的“课程思政”。

Lyapunov-based fixed-time stabilization control of quantum systems

In this paper,we consider the fixed-time stabilization control problem of quantum systems modeled by Schrodinger equations.Firstly,the Lyapunov-based fixed-time stability criterion is extended to finitedimensional closed quantum systems in the form of coherence vectors.Then for a two-level quantum system with single control input,a non-smooth fractional-order control law is designed using the relative state distance.By integrating the fixed-time Lyapunov control technique and the bi-limit homogeneity theory,the quantum system is proved to be stabilized to an eigenstate of the inherent Hamiltonian in a fixed time.Comparing with existing methods in quantum system control,the proposed approach can guarantee stabilization in a fixed time without depending on the initial states.

2-D distributed pose estimation of multi-agent systems using bearing measurements

This article studies distributed pose(orientation and position)estimation of leader–follower multi-agent systems over𝜅-layer graphs in 2-D plane.Only the leaders have access to their orientations and positions,while the followers can measure the relative bearings or(angular and linear)velocities in their unknown local coordinate frames.For the orientation estimation,the local relative bearings are used to obtain the relative orientations among the agents,based on which a distributed orientation estimation algorithm is proposed for each follower to estimate its orientation.For the position estimation,the local relative bearings are used to obtain the position constraints among the agents,and a distributed position estimation algorithm is proposed for each follower to estimate its position by solving its position constraints.Both the orientation and position estimation errors converge to zero asymptotically.A simulation example is given to verify the theoretical results.

含不对称茚满结构聚酰亚胺的合成与表征

以双酚A为原料,通过有机合成制备含不对称茚满结构的二胺单体6-(4-氨基-2-三氟甲基)苯氧基-1-[4-(4-氨基-2-三氟甲基)苯氧基]苯基-1,3,3,-三甲基茚满,并与5种二酐通过化学亚胺化法制备含茚满结构聚酰亚胺。通过红外光谱、核磁共振、溶解性能测试、紫外可见光谱、差示扫描量热分析、热重分析等对聚合物进行测试。结果表明,该系列聚酰亚胺室温下在低沸点溶剂如CHCl3,CH2Cl2,THF,丙酮等中也表现出非常优异的溶解性能;在450~760 nm范围内具有优异的光学性能,550 nm处透光率高达88.1%;玻璃化转变温度在228~265℃,5%热失重温度(N2氛围)在484~520℃,具有良好的热性能;拉伸强度为75.8~92.5 MPa,弹性模量为1.3~2.0 GPa,断裂伸长率为3.2%~10.8%,表现出良好的力学性能。

Detection of composition of functional component theabrownins in Pu-erh tea by degradation method

Habitual tea consumption can reduce the risk of ASCVD morbidity and mortality and all-cause mortality in China,and long-term adherence to this habit can provide greater protection.Pu-erh tea is one of the representatives of post-fermented teas,and the polymers in Pu-erh tea have anti-cancer and anti-hyperlipidemic activities,but their chemical composition is still unknown.In this study,the chemical composition of Pu-erh tea was investigated in detail and eight(1–8)known compounds were isolated.The polymers in Pu-erh tea were also degraded by thiol degradation,and the fragments of quercetin and(–)-epicatechin-3-O-gallate were found in the thiol degradation products of Pu-erh tea polymers by UPLC observation and separation and purification.This is the first time that this fragment was obtained in Pu-erh tea polymer.

Bearing Fault Diagnosis Method of Wind Turbine Based on Improved Anti-Noise Residual Shrinkage Network

Aiming at the difficulty of rolling bearing fault diagnosis of wind turbine under noise environment,a new bearing fault identification method based on the Improved Anti-noise Residual Shrinkage Network(IADRSN)is proposed.Firstly,the vibration signals of wind turbine rolling bearings were preprocessed to obtain data samples divided into training and test sets.Then,a bearing fault diagnosis model based on the improved anti-noise residual shrinkage network was established.To improve the ability of fault feature extraction of the model,the convolution layer in the deep residual shrinkage network was replaced with a Dense-Net layer.To further improve the anti-noise ability of the model,the first layer of the model was set as the Drop-block layer.Finally,the labeled data samples were used for training model and the trained model was applied to the test set to output the fault diagnosis results.The results showed that the proposed method could achieve the fault diagnosis of wind turbine bearing more accurately in the high noise environment through comparison and verification.

Break-Even Analysis on the Charging and Battery-Swapped Station of Electric Vehicles

The construction of electric vehicle charging station plays an important role in the development of electric vehicles and the promotion of the renewable resource. In the paper, a model to analyze the economic benefit of the charging station is presented, which is based on the break-even theory. Then the threshold price is calculated based on the model according to the construction plans of charging facilities in one district. Finally, the strategy for the development of charging faculties is proposed to improve the health growth of electric automotive industry.

Convergence Rate of Solutions to a Hyperbolic Equation with p(x)-Laplacian Operator and Non-Autonomous Damping

This paper concerns the convergence rate of solutions to a hyperbolic equation with p(x)-Laplacian operator and non-autonomous damping.We apply the Faedo-Galerkin method to establish the existence of global solutions,and then use some ideas from the study of second order dynamical system to get the strong convergence relationship between the global solutions and the steady solution.Some differential inequality arguments and a new Lyapunov functional are proved to show the explicit convergence rate of the trajectories.

Optimal model establishment of whole-process management data for CAR-T therapy in China—how should this be done?

Chimeric antigen receptor(CAR)T-cell therapy utilizes patients’own T lymphocytes that are engineered to attack cancer cells[1,2,3].With the US Food and Drug Administration(FDA)approval of four CD19-and one BCMA-targeted CAR therapy for B cell malignancies[4,5],CAR T-cell therapy has finally reached the status of a medicinal product.

DNA methylation-mediated repression of miR-181a/135a/302c expression promotes the microsatellite-unstable colorectal cancer development and 5-FU resistance via targeting PLAG1

Micro sate Hite instability（MSI） defines a subtype of colorectal cancer（CRC） with typical clinicopathologic characteristics. CRCs with MSI（MSI CRCs） frequently acquire accelerated carcinogenesis and 5-FU resistance, and the exact underlying mechanism remains incompletely understood. Our previous study has identified the microRNA（miRNA） expression profile in MSI CRCs. In this study, three miRNAs（miR-181 a, miR-135 a and miR-302 c） were validated by qRT-PCR to be dramatically decreased in 67 CRC samples. Proliferation and apoptosis assays demonstrated that miR-181 a/135 a/302 c function as tumor suppressors via repressing PLAG1/IGF2 signaling. Moreover, we presented compelling evidence that restoration of miR-181 a/135 a/302 c expression promoted sensitivity of MSI CRC cells to 5-FU treatment. miR-181 a/135 a/302 c exerted their effect on chemoresistance through attenuating PLAG1 expression. Notably, the hypermethylation status of MSI CRC accounts for the decrements of miR-181 a/135 a/302 c. Our results contribute to a better understanding of the mechanism of chemo？resistance in MSI CRCs, and provide a clue for digging the bio markers and therapeutic targets for CRC patients.

Structure,retrogradation and digestibility of waxy corn starch modified by a GtfC enzyme from Geobacillus sp.12AMOR1

To lower the retrogradation and digestibility of waxy corn starch for different food applications,a novel thermostable GtfC type 4,6-α-glucanotransferase without N-and C-terminals(GsGtfC)from Geobacillus sp.12AMOR1 was used.Waxy corn starch of 50 g/L was incubated with GsGtfC of 40-100 U/g substrate at 65℃and pH 5.5 for 1 h.Its molecular weight,iodine affinity,XRD crystallinity,and FTIR ratio of heights of bands at 1047 and 1022 cm^(-1) decreased,but ratio of DP<6 to DP≥25 branches and degree of branching increased.GsGtfC cleavedα-1,4-glycosidic bonds and inducedα-1,6-branching points to produce reuteran-likes polymers,which is different from Exiguobacterium sibiricum GtfC enzyme cleavingα-1,4-glycosidic bonds and synthesizing consecutiveα-1,6-glycosidic bonds to produce isomalto/malto-oligosaccharides.GsGtfC modified waxy corn starch had significantly lower DSC retrogradation enthalpies during the storage at 4℃for 3-14 days and significantly lower released glucose during the incubation with mammalian mucosalα-glucosidase at 37℃for 10-360 min.GsGtfC at 100 U/g substrate increased slowly digestible portion from 11.07%to 24.11%.

Type I vaccine-derived polioviruses in China from 1995 to 2019

A nation-wide case surveillance was conducted in China since 1995 for the objective of identifying acute flaccid paralysis(AFP)in children so that potential wild polioviruses and vaccine-derived poliovirus(VDPV)could be identified on time.Two outbreaks associated with type I circulating VDPVs,eight native independent type I ambiguous VDPVs(aVDPV),and one imported aVDPV were identified during the AFP case surveillance in China from 1995 to 2019.The VP1 coding region of the Chinese type I VDPVs differed from the polio vaccine strain by 1.00%–3.75%(9–34 substitutions in 906 nucleotides).Most of the Chinese type I VDPV strains shared 4 amino acid substitutions in the neutralizing antigenic(NAg)sites:3 located at the BC loop,which formed the NAg site 1,and another at NAg site 3a.All of the Chinese type I VDPVs identified during the AFP case surveillance were young VDPVs,which indicated a limited viral replication resulted from the administration of the initiating oral polio vaccine(OPV)dose.VDPVs can emerge and spread in isolated communities with immunity gaps and the circulation ceases following a mass immunization with OPV.As such,high-quality surveillance permitted very early detection and response and it played a key role in stalling the widespread circulation of the emergent cVDPV strains in China.

Hydrothermal conversion of lignin and black liquor for phenolics with the aids of alkali and hydrogen donor

The potentials of phenolic productions from lignin and black liquor(BL)via hydrothermal technology with the aids of alkalis and hydrogen donors were investigated,by conducting batch experiments in micro-tube reactors with 300℃ sub-critical water as the solvent.The results showed that all the employed alkalis improved lignin degradation and thus phenolics production,and the strong alkalis additionally manifested deoxygenation to produce more phenolics free of methoxyl group(s).Relatively,hydrogen donors more visibly facilitated phenolics formation.Combination of strong alkali and hydrogen donors exhibited synergistically positive effects on producing phenolics(their total yield reaching 22 wt%)with high selectivities to phenolics,among which the yields of catechol and cresols respectively peaked 16 and 3.5 wt%.BL could be hydrothermally converted into phenolics at high yields(approaching 10 wt%with the yields of catechol and cresols of about 4 and 2 wt%,respectively)with the aids of its inherent alkali and hydrogen donors,justifying its cascade utilization.

Epidemiological survey and genetic characterization of type 3 vaccine-derived poliovirus isolated from a patient with four doses of inactivated polio vaccine in Henan Province,China

Background:Vaccine-derived poliovirus(VDPV)is a potential threat to polio eradication because they can reintroduce into the general population and cause paralytic polio outbreaks,a phenomenon that has recently emerged as a prominent public health concern at the end of global polio eradication.This study aimed to describe the epidemiology and genetic characteristics of the frst VDPV identifed from a patient with acute faccid paralysis(AFP),with four doses of inactivated polio vaccine immunization in Henan Province,China in 2017.Methods:The patient was diagnosed with type 3 VDPV.Subsequently,a series of epidemiological approaches was implemented,including a retrospective search of AFP cases,rate of vaccination assessment,study of contacts,and supplementary immunization activities.Fecal samples were collected,viral isolation was performed,and the viral isolates were characterized using full-length genomic sequencing and bioinformatic analysis.Results:Phylogenetic analysis showed that the viral isolates from the patient were diferent from other reported genetic clusters of type 3 VDPV worldwide.They were identifed as a Sabin 3/Sabin 1 recombinant VDPV with a crossover site in the P2 region.Nucleotide substitutions,including U→C(472)and C→U(2493),have been identifed,both of which are frequently observed as reversion mutations in neurovirulent type 3 poliovirus.A unique aspect of this case is that the patient had been vaccinated with four doses of inactive polio vaccine,and the serum neutralizing antibody for Sabin types 1 and 3 were 1∶16 and 1∶512,respectively.Thus,the patient was speculated to have been infected with type 3 VDPV,and the virus continued to replicate and be excreted for at least 41 d.Conclusions:The existence of this kind of virus in human population is a serious risk and poses a severe challenge in maintaining a polio-free status in China.To the best of our knowledge,this is the frst report of VDPV identifed in the Henan province of China.Our results highlight the importance of maintaining a high-level vaccination rate and highly sensitive AFP case surveillance system in intercepting VDPV transmission.

Multiple measurements of quasars acting as standard probes: Model independent calibration and exploring the dark energy equation of states

Recently, two classes of quasar samples were identified, which are promising as new cosmological probes extending to higher redshifts. The first sample uses the nonlinear relation between the ultraviolet and X-ray luminosities of quasars to derive luminosity distances, whereas the linear sizes of compact radio quasars in the second sample can serve as standardized rulers, providing angular-diameter distances. In this study, under the assumption of a flat universe, we refreshed the calibration of multiple measurements of high-redshift quasars(in the framework of a cosmological-model-independent method with the newest Hubble parameters data). Furthermore, we placed constraints on four models that characterize the cosmic equation of state(w). The obtained results show that:(1) the two quasar samples could provide promising complementary probes at much higher redshifts,whereas compact radio quasars perform better than ultraviolet and X-ray quasars at the current observational level;(2) strong degeneracy between the cosmic equation of state(w) and Hubble constant(H0) is revealed, which highlights the importance of independent determination of H0 from time-delay measurements of strongly lensed quasars;(3) together with other standard ruler probes, such as baryon acoustic oscillation distance measurements, the combined QSO+BAO measurements are consistent with the standard ΛCDM model at a constant equation of state w =-1;(4) ranking the cosmological models, the polynomial parametrization gives a rather good fit among the four cosmic-equation-of-state models, whereas the Jassal-Bagla-Padmanabhan(JBP) parametrization is substantially penalized by the Akaike Information Criterion and Bayesian Information Criterion.

A comparative study on environmental surveillance of enterovirus:Using a two-phase separation method and a filtration method with a mixed cellulose ester(MCE)membrane

This study aimed to compare the sensitivity of two-phase separation and the filtration method using a mixed cellulose ester(MCE)membrane to detect enteroviruses in sewage samples.From December 2015 to July 2016,four domestic sewage samples(1 L/sample)were collected monthly from the Guangzhou Liede Sewage Treatment Plant,and each sewage sample was divided into two aliquots(500 mL).The sewage sample was concentrated using the two-phase separation and the filtration method using an MCE membrane,and the treated solutions were inoculated into cells for enterovirus isolation.Polymerase chain reaction amplification,VP1 sequencing,and enterovirus molecular typing were performed on the positive isolates.The detection rates of poliovirus(PV)and non-polio enterovirus(NPEV)obtained using the filtration method using an MCE membrane were higher than those using the two-phase separation method.McNemar's test showed that the detection rates of PV,NPEV,type 1 Sabin-like(SL1),type 2 Sabin-like(SL2),and type 3 Sabin-like(SL3)strain were not statistically significant(P>0.05).In Guangdong Province,China,the detection rates for PV and NPEV were 53.13%and 62.50%(20/32),respectively.Twenty-seven PVs were isolated,three highly variable strains of the type 1 vaccine,with seven nucleotide substitutions in the VP1 region,compared with the type 1 Sabin strains.Eighty-seven strains of NPEV were isolated and nine serotypes were identified,among which coxsackievirus B3(CVB3),echovirus 6(E6),and echovirus 11(E11)were the dominant strains.The filtration method using an MCE membrane is more sensitive than two-phase separation and can be used as a robust,sensitive,and cost-effective method to isolate enteroviruses from sewage.

Two-dimensional g-C_(3)N_(4)nanosheets-based photo-catalysts for typical sustainable processes

Graphitic carbon nitride(g-C_(3)N_(4))has been widely studied as a visible light responsive photocatalyst in recent years,due to its facile synthesis,low cost,high stability,and appropriate bandgap/band positions.In this review,we firstly introduce and compare various exfoliation approaches of bulk g-C_(3)N_(4)into ultrathin g-C_(3)N_(4)nanosheets.Then,many modification strategies of g-C_(3)N_(4)nanosheets are also reviewed,including heterojunction construction,doping,defect control,and structure design.Thereafter,the charge transfer mechanism in g-C_(3)N_(4)nanosheets based heterojunctions is present,e.g.,Z-scheme,S-scheme and other forms.Besides,the photocatalytic applications of g-C_(3)N_(4)nanosheets based photocatalysts are summarized including environmental remediation,energy generation and storage,organic synthesis,and disinfection.This review ends with a summary and some perspectives on the challenges and new directions in exploring g-C_(3)N_(4)nanosheets-based photocatalysts.

托珠单抗成功治疗儿童发热感染相关癫痫综合征1例及文献复习

目的报道托珠单抗在1例儿童发热感染相关癫痫综合征(FIRES)患者中的成功应用,为FIRES患儿的治疗提供新思路。方法总结郑州大学附属儿童医院于2021年2月15日收治的1例FIRES患儿诊疗经过及其对托珠单抗的治疗反应,并对患者进行随访和预后评估,同时对托珠单抗治疗儿童FIRES的文献进行复习。结果该患儿5岁起病,经多种抗癫痫药物、麻醉药物、激素、静脉注射免疫球蛋白等免疫治疗及生酮饮食治疗均无效,呈超级难治性癫痫持续状态,因此于病史36 d及43 d各应用1次托珠单抗(每次4 mg/kg)。第2剂托珠单抗治疗10 d后患儿癫痫发作得以控制。随访10个月,患儿癫痫发作控制良好,认知行为及言语功能明显恢复。目前仅检索到了2篇共3例儿童FIRES患者应用托珠单抗治疗的报道,均显示有效,未见明显不良反应。结论FIRES是一种罕见的难治性癫痫综合征,对多种抗癫痫药物甚至麻醉剂耐药,治疗困难,预后差。初步的尝试显示托珠单抗对儿童FIRES患者有效,耐受性好,是一种具备潜力的治疗手段之一。