A Study on the Transmission Dynamics of the Omicron Variant of COVID-19 Using Nonlinear Mathematical Models

This research examines the transmission dynamics of the Omicron variant of COVID-19 using SEIQIcRVW and SQIRV models,considering the delay in converting susceptible individuals into infected ones.The significant delays eventually resulted in the pandemic’s containment.To ensure the safety of the host population,this concept integrates quarantine and the COVID-19 vaccine.We investigate the stability of the proposed models.The fundamental reproduction number influences stability conditions.According to our findings,asymptomatic cases considerably impact the prevalence of Omicron infection in the community.The real data of the Omicron variant from Chennai,Tamil Nadu,India,is used to validate the outputs.

Stabilization Controller of An Extended Chained Nonholonomic System With Disturbance:An FAS Approach

This study examines the stabilization issue of extended chained nonholonomic systems(ECNSs)with external disturbance.Unlike the existing approaches,we transform the considered system into a fully actuated system(FAS)model,simplifying the stabilizing controller design.We implement a separate controller design and propose exponential stabilization controller and finite-time stabilization controller under finite-time disturbance observer(FTDO)for the two system inputs.In addition,we discuss the specifics of global stabilization control design.Our approach demonstrates that two system states exponentially or asymptotically converge to zero under the provided switching stabilization control strategy,while all other system states converge to zero within a finite time.

A NOTE ON THE GENERAL STABILIZATION OF DISCRETE FEEDBACK CONTROL FOR NON-AUTONOMOUS HYBRID NEUTRAL STOCHASTIC SYSTEMS WITH A DELAY

Discrete feedback control was designed to stabilize an unstable hybrid neutral stochastic differential delay system(HNSDDS) under a highly nonlinear constraint in the H_∞ and exponential forms.Nevertheless,the existing work just adapted to autonomous cases,and the obtained results were mainly on exponential stabilization.In comparison with autonomous cases,non-autonomous systems are of great interest and represent an important challenge.Accordingly,discrete feedback control has here been adjusted with a time factor to stabilize an unstable non-autonomous HNSDDS,in which new Lyapunov-Krasovskii functionals and some novel technologies are adopted.It should be noted,in particular,that the stabilization can be achieved not only in the routine H_∞ and exponential forms,but also the polynomial form and even a general form.

Set Stabilization of Large-Scale Stochastic Boolean Networks:A Distributed Control Strategy

Dear Editor,This letter deals with the set stabilization of stochastic Boolean control networks(SBCNs)by the pinning control strategy,which is to realize the full control for systems by imposing control inputs on a fraction of agents.

Passivity-Based Stabilization for Switched Stochastic Nonlinear Systems

Dear Editor,This letter addresses the passivity-based mean square exponential stabilization problem for switched stochastic nonlinear systems.A concept of generalized small-time norm-observability is presented and an appropriate test condition is also provided.For pre-given passivity rate and average dwell time,a set of feedback controllers is designed by use of the passivity property.

Output Feedback Stabilization of High-Order Nonlinear Time-Delay Systems With Low-Order and High-Order Nonlinearities

Dear Editor,to This letter deals with the output feedback stabilization of a class of high-order nonlinear time-delay systems with more general low-order and high-order nonlinearities.By constructing reduced-order observer,based on homogeneous domination theory together with the adding a power integrator method,an output feedback controller is developed guarantee the equilibrium of the closed system globally uniformly asymptotically stable.

Structural and electrochemical stabilization enabling high-energy P3-type Cr-based layered oxide cathode for K-ion batteries

Layered-type transition metal(TM)oxides are considered as one of the most promising cathodes for K-ion batteries because of the large theoretical gravimetric capacity by low molar mass.However,they suffer from severe structural change by de/intercalation and diffusion of K^(+)ions with large ionic size,which results in not only much lower reversible capacity than the theoretical capacity but also poor power capability.Thus,it is important to enhance the structural stability of the layered-type TM oxides for outstanding electrochemical behaviors under the K-ion battery system.Herein,it is investigated that the substitution of the appropriate Ti^(4+)contents enables a highly enlarged reversible capacity of P3-type KxCrO_(2) using combined studies of first-principles calculation and various experiments.Whereas the pristine P3-type KxCrO_(2) just exhibits the reversible capacity of∼120 mAh g^(−1) in the voltage range of 1.5-4.0 V(vs.K^(+)/K),the∼0.61 mol K^(+)corresponding to∼150 mAh g^(−1) can be reversible de/intercalated at the structure of P3-type K0.71[Cr_(0.75)Ti_(0.25)]O_(2) under the same conditions.Furthermore,even at the high current density of 788 mA g^(−1),the specific capacity of P3-type K0.71[Cr_(0.75)Ti_(0.25)]O_(2) is∼120 mAh g^(−1),which is∼81 times larger than that of the pristine P3-type KxCrO_(2).It is believed that this research can provide an effective strategy to improve the electrochemical performances of the cathode materials suffered by severe structural change that occurred during charge/discharge under not only K-ion battery system but also other rechargeable battery systems.

Nonlinear robust adaptive control for bidirectional stabilization system of all-electric tank with unknown actuator backlash compensation and disturbance estimation

Since backlash nonlinearity is inevitably existing in actuators for bidirectional stabilization system of allelectric tank,it behaves more drastically in high maneuvering environments.In this work,the accurate tracking control for bidirectional stabilization system of moving all-electric tank with actuator backlash and unmodeled disturbance is solved.By utilizing the smooth adaptive backlash inverse model,a nonlinear robust adaptive feedback control scheme is presented.The unknown parameters and unmodelled disturbance are addressed separately through the derived parametric adaptive function and the continuous nonlinear robust term.Because the unknown backlash parameters are updated via adaptive function and the backlash effect can be suppressed successfully by inverse operation,which ensures the system stability.Meanwhile,the system disturbance in the high maneuverable environment can be estimated with the constructed adaptive law online improving the engineering practicality.Finally,Lyapunov-based analysis proves that the developed controller can ensure the tracking error asymptotically converges to zero even with unmodeled disturbance and unknown actuator backlash.Contrast co-simulations and experiments illustrate the advantages of the proposed approach.

A frequency servo SoC with output power stabilization loop technology for miniaturized atomic clocks

A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.

Adaptive Robust Servo Control for Vertical Electric Stabilization System of Tank and Experimental Validation

A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabilization system:model parameter uncertainty and uncertain nonlinearity.First,the vertical electric stabilization system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the system.Second,the dynamical equation in the form of state space is established by designing the angular tracking error.Third,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of uncertainty.Finally,an adaptive robust servo control which can effectively handle the combined effects of complex nonlinearity and uncertainty is proposed.The feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the experimental platform.This paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabilization system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through experiment for the first time.

Identifying the stability of housekeeping genes to be used for the quantitative real-time PCR normalization in retinal tissue of streptozotocin-induced diabetic rats

AIM:To investigate the stability of the seven housekeeping genes:beta-actin(ActB),glyceraldehyde-3-phosphate dehydrogenase(GAPDH),18s ribosomal unit 5(18s),cyclophilin A(CycA),hypoxanthine-guanine phosphoribosyl transferase(HPRT),ribosomal protein large P0(36B4)and terminal uridylyl transferase 1(U6)in the diabetic retinal tissue of rat model.METHODS:The expression of these seven genes in rat retinal tissues was determined using real-time quantitative reverse transcription polymerase chain reaction(RT-qPCR)in two groups;normal control rats and streptozotocininduced diabetic rats.The stability analysis of gene expression was investigated using geNorm,NormFinder,BestKeeper,and comparative delta-Ct(ΔCt)algorithms.RESULTS:The 36B4 gene was stably expressed in the retinal tissues of normal control animals;however,it was less stable in diabetic retinas.The 18s gene was expressed consistently in both normal control and diabetic rats’retinal tissue.That this gene was the best reference for data normalisation in RT-qPCR studies that used the retinal tissue of streptozotocin-induced diabetic rats.Furthermore,there was no ideal gene stably expressed for use in all experimental settings.CONCLUSION:Identifying relevant genes is a need for achieving RT-qPCR validity and reliability and must be appropriately achieved based on a specific experimental setting.

多发性骨髓瘤患者FISH检测结果与Durie-Salmon分期和R-ISS分期的相关性

目的 探讨多发性骨髓瘤(MM)患者荧光原位杂交(FISH)检测结果与Durie-Salmon分期(DS)和国际分期系统(R-ISS)的关系。方法 选取惠州市中心人民医院2020年1月至2021年1月收治的MM患者80例为研究对象,利用FISH技术检测患者CKS1B(1q21)、p53、RB1、IGH基因表达情况,分析FISH检测结果与DS分期和R-ISS分期的关系。单因素及Cox回归分析MM患者预后的独立危险因素。结果 DS分期和R-ISS分期越高,FISH检测结果阳性发生率越高,不同DS分期、R-ISS分期分别与FISH检测结果比较,差异均有统计学意义(P<0.05)。单因素显示,治疗方案、1q21扩增、p53缺失、RB1缺失、IGH重排与患者预后转归比较,差异均有统计学意义(P<0.05)。Cox回归分析显示,1q21扩增、p53缺失、RB1缺失、IGH重排为MM患者预后结局的独立影响因素(P<0.05),其中,1q21扩增、p53缺失、RB1缺失、IGH重排阳性者1年生存率均低于阴性者。结论 FISH检测结果阳性发生率越高,DS分期和R-ISS分期则越高,且1q21扩增、p53缺失、RB1缺失、IGH重排为MM患者预后结局的独立影响因素。

ISS分期与FISH对多发性骨髓瘤临床治疗的效果及预后意义

目的:探讨ISS分期与FISH对多发性骨髓瘤临床治疗的效果及预后意义。方法:采集湖北省荆州中心医院血液内科2018年7月至2022年7月诊治的200例多发性骨髓瘤患者,ISS I期41例,ISS II期73例,ISS III期86例。采取硼替佐米诱导治疗,利用FISH荧光原位杂交检测对其进行检验,统计分析不同ISS分期多发性骨髓瘤患者的FISH检测和临床疗效。结果:41例ISS I期患者中有18例患者检测为FISH阳性,14例患者检测为FISH多阳性,23例患者检测为FISH阴性。73例ISS II期患者中有51例患者检测为FISH阳性,42例患者检测为FISH多阳性,22例患者检测为FISH阴性。86例ISS III期患者中有86例患者检测为FISH阳性,70例患者检测为FISH多阳性。不同ISS分期多发性骨髓瘤患者的FISH阳性检出率及FISH多阳性检出率,组间差异具有统计学意义(P<0.05)。41例ISS I期患者中有31例患者为完全缓解,6例患者为部分缓解,4例患者检测为病情稳定。73例ISS II期患者中有43例患者为完全缓解,18例患者为部分缓解,12例患者检测为病情稳定。86例ISS III期患者中有33例患者为完全缓解,33例患者为部分缓解,20例患者检测为病情稳定。不同ISS分期多发性骨髓瘤患者完全缓解、部分缓解以及病情稳定等临床疗效对比,组间差异具有统计学意义(P<0.05)。结论:多发性骨髓瘤患者的ISS分期及FISH结果与患者临床完全缓解呈负相关关系,医护人员可通过ISS分期与FISH检测对其进行分组,进行临床疗效评估以及预后质量评估。

基于ISS-LCG组合特征点的油菜分枝点云配准方法

[目的]针对传统点云配准方法准确率低、速度慢等问题,以油菜Brassica napus L.分枝点云为研究对象,提出基于ISS-LCG组合特征点的配准方法。[方法]以成熟期油菜角果分枝点云为对象,去除背景噪声后,得到清晰完整的油菜分枝点云;然后通过内部形状描述子(Intrinsic shape signature,ISS)提取油菜分枝点云的特征点,再使用线性同余法(Linear congruential generator,LCG)伪随机选取油菜点云的部分点构成关键点,将特征点和关键点进行融合,构成ISS-LCG组合特征点;通过三维形状上下文特征(3D shape context,3DSC)对组合特征点进行特征描述,最后采用RANSAC+ICP两步点云配准法进行点云配准。[结果]基于ISS-LCG组合特征点的点云配准算法以30°为间隔对点云进行两两配准时,配准效果最佳,配准误差约0.066 mm,配准精度比未采用组合特征点的配准方法提升了50%~70%;配准时间均小于48 s,平均配准时间为8.706 s。[结论]该方法在可控环境内可以实现成熟期油菜植株高精度、高效率的自动配准。

To the issue of stabilization of permafrost soil subgrade

This paper summarizes an analysis of consequences of railway subgrade construction and maintenance solutions in northern areas of the Russian Far East. An idea of the natural long-term stabilization of the subgrade-base geotechnical system is presented. Proposals to improve the decision-making of construction and engineering solutions are formulated.

Molecular simulation study of the stabilization process of NEPE propellant

In this reported study, the density functional theory(DFT) was used at the(U)B3LYP/6-311G(d,p) level to investigate the stabilization process of the nitrate ester plasticized polyether propellant(NEPE). Molecular simulations were conducted of the reaction that generates NO_(2), the autocatalytic and aging reaction triggered by the NO_(2), and the nitrogen dioxide absorption reaction of the stabilizers during the propellent stabilization process. These simulations were derived using the transition-state theory(TST)and variational transition-state theory(VTST). The simulation results suggested that the stabilization of the NEPE propellant consisted of three stages. First, heat and NO_(2) were generated during the denitrification reaction of nitroglycerine(NG) and 1,2,4-butanetriol trinitrate(BTTN) in the NEPE propellant.Second, nitroso products were generated by the reactions of N-Methyl-4-nitroaniline(MNA) and 2-nitrodiphenylamine(2NDPA) with NO_(2). Third, the stabilizers were exhausted and the autocatalytic reaction of NG and BTTN and the aging reaction of polyethylene glycol(PEG) were triggered by the heat and NO_(2)generated in the first stage. By comparing the energy barriers of the various reactions, it was found that the NO_(2)generated from the denitrification reaction significantly reduced the reaction energy barrier to 105.56-126.32 kJ/mol, also increased the reaction rate constant, and decreased the thermal stability and energetic properties of the NEPE propellant. In addition, the NO_(2)also weakened the mechanical properties of the NEPE propellant by attacking the-CH2groups and the O atoms in the PEG molecular chain. The energy barriers of the reactions of MNA and 2NDPA with NO_(2)(94.61-133.61 k J/mol) were lower than those of the autocatalytic and decomposition reactions of NG, BTTN, and the aging reactions of PEG(160.30-279.46 kJ/mol). This indicated that, by eliminating NO_(2), the stabilizer in the NEPE propellant can effectively prevent NO_(2)from reacting with the NG, BTTN, and PEG in the NEPE propellant. Consequently, this would help maintain the energy and mechanical properties of the NEPE propellant, thereby improving its thermal stability.

Prescribed-Time Stabilization of Singularly Perturbed Systems

Dear Editor, This letter investigates the prescribed-time stabilization of linear singularly perturbed systems. Due to the numerical issues caused by the small perturbation parameter, the off-the-shelf control design techniques for the prescribed-time stabilization of regular linear systems are typically not suitable here. To solve the problem, the decoupling transformation techniques for time-varying singularly perturbed systems are combined with linear time-varying high gain feedback design techniques.

多发性骨髓瘤患者FISH检测结果与Durie-Salmon分期和R-ISS分期的相关性分析

目的探究多发性骨髓瘤(MM)患者原位荧光杂交技术(FISH)检测结果与Durie-Salmon分期(DS)和R-ISS分期的相关性。方法回顾性选取2020年1月至2022年2月河北北方学院附属第一医院90例MM患者作为研究对象,所有患者均行FISH检测,主要包括lq21扩增、l3q14缺失、IGH重排与P53缺失,并予以DS分期与R-ISS分期,记录患者的临床特征,分析FISH检测结果与DS分期和R-ISS分期的相关性。结果FISH检测结果显示,90例MM患者中lq21扩增阳性35例,l3q14缺失阳性27例,IGH重排阳性24例,P53缺失4例;lq21扩增阳性与阴性患者在DS分期、R-ISS分期方面差异有统计学意义(P<0.05);l3q14缺失阳性与阴性患者在DS分期、R-ISS分期方面差异有统计学意义(P<0.05);IGH重排阳性与阴性患者在DS分期、R-ISS分期方面差异有统计学意义(P<0.05);P53缺失阳性与阴性患者在DS分期、R-ISS分期方面差异无统计学意义(P>0.05)。经过Spearson相关性分析,结果显示lq21扩增、l3q14缺失、IGH重排与DS分期和R-ISS分期均呈明显正相关(P<0.05);P53缺失与DS分期和R-ISS分期无相关性(P>0.05)。结论MM患者多伴随FISH检测结果异常,表现为lq21扩增、l3q14缺失、IGH重排与P53缺失,其中lq21扩增、l3q14缺失、IGH重排与患者DS分期、R-ISS分期呈正相关,可将FISH检测与Durie-Salmon分期、R-ISS分期联合应用于MM预后评估。

rhGH联合赖氨酸在青春期大骨龄ISS患儿中的临床应用与研究

目的:分析rhGH联合赖氨酸在青春期大骨龄ISS患儿中的应用效果。方法:选取90例ISS患儿作为研究对象,分为男童组和女童组,45例/组,进一步分为对照组、rhGH治疗组、rhGH联合赖氨酸治疗组,15例/组。对照组进行常规的生活指导和心理支持,rhGH治疗组联合rhGH治疗,rhGH联合赖氨酸治疗组再联合赖氨酸治疗。对比治疗前、1年后的生长发育指标、骨龄、预测终身高,并统计不良反应情况。结果:治疗前各小组之间的各项指标对比差异无统计学意义(P>0.05),1年后,男童组和女童组中的rhGH联合赖氨酸治疗组的身高、体质量、身高生长速率、预测终身高均高于其他两组,且rhGH治疗组高于对照组,骨龄低于其他两组,且rhGH治疗组低于对照组(P<0.05)。各组均未出现明显的不良反应。结论:rhGH联合赖氨酸治疗青春期大骨龄ISS能有效调节生长发育情况,安全性高。

Effects of biochar-amended alkali-activated slag on the stabilization of coral sand in coastal areas

Coral sand is widely encountered in coastal areas of tropical and subtropical regions.Compared with silica sand,it usually exhibits weaker performance from the perspective of engineering geology.To improve the geomechanical performance of coral sand and meet the requirement of foundation construction in coastal areas,a novel alkali activation-based sustainable binder was developed.The alkaliactivated slag(AAS)binder material was composed of ground granulated blast-furnace slag(GGBS)and hydrated lime with the amendment of biochar,an agricultural waste-derived material.The biocharamended AAS stabilized coral sand was subjected to a series of laboratory tests to determine its mechanical,physicochemical,and microstructural characteristics.Results show that adding a moderate amount of biochar in AAS could improve soil strength,elastic modulus,and water holding capacity by up to 20%,70%,and 30%,respectively.Moreover,the addition of biochar in AAS had a marginal effect on the sulfate resistance of the stabilized sand,especially at high biochar content.However,the resistance of the AAS stabilized sand to wet-dry cycles slightly deteriorated with the addition of biochar.Based on these observations,a conceptual model showing biochar-AAS-sand interactions was proposed,in which biochar served as an internal curing agent,micro-reinforcer,and mechanically weak point.