物业小区治理结构的转换:“线性”结构到“复合式”结构——以北京上地西里社区为例

随着我国住房制度的改革、房屋产权的变化,逐渐形成了以私有房产为基础的物业小区自治。在实践中,以北京上地西里为代表的社区逐步探索出了一个不同于法定的“线性”治理结构的“复合式”的治理结构,这种结构的转换体现了分工和分权制衡的思想,体现了代议制的思想。无论是“复合式”结构中的业主代表大会还是业主监事会都是治理实践的迫切需要,对其进行探索意义重大。

探究格鲁贝洛娃花腔演唱艺术中的“线性”审美

花腔女高音歌唱家埃迪塔.格鲁贝洛娃(Edita Gruberova 1946—)被英国皇家歌剧院的艺术总监皮托.卡托纳(Petor Katona)认为是少数能将声音之美发挥到极致的女歌唱家之一。她的声音晶莹明亮,但又不乏宽宏柔韧,能根据不同情感和旋律的需要来刻画艺术形象,善于运用连贯流畅而富于变化的声音线条表现出花腔女高音演唱中少有的戏剧张力,形成声音上独有的线条特征。本文通过对格鲁贝洛娃花腔演唱艺术中所展现出的"线性"审美进行探究,揭示美丽之声的根源,这对进行花腔女高音演唱的人来说具有指导意义。

城市“线性”空间景观设计探究

"线性"空间是城市构成的重要部分,主要是指道路、河流等空间。它对组织城市系统,连接区域空间,有着重要作用,是支撑整个城市布局的"骨架"与"血脉"。因此,"线性"空间景观的设计对美化城市环境,提高城市形象和城市居民生活质量有着积极的作用。但现有的"线性"景观大多是先建设后绿化,缺乏整体的规划和对城市可持续发展战略,以及生态理念的考虑。

小学说理性文体的“线性”教学策略

文章以小学语文教材中三篇说理文为例对小学说理性文体的“线性”教学策略进行了阐述,具体包括关注文本结构,初识说理文体;挖掘典型事例,感悟说理智慧;聚焦逻辑魅力,破解说理密码三个方面。

基于BOPPPS模式的“线性代数”教学设计与实践

“线性代数”是本科院校理工类专业必修的一门公共基础课,具有理论抽象、逻辑严密及计算复杂的特点。为了落实新工科背景下以学生为中心的教学理念,针对“线性代数”教学中课时少任务重、重推导轻应用的问题,文章探索了基于BOPPPS模式的“线性代数”课程教学设计与实践,以实现知识教育与思政教育的有机结合,进一步提高学生的数学专业能力,还能有效培养学生的思想政治素质和社会责任感。

新工科背景下人工智能赋能“线性代数”课程的路径与策略

文章以提升大学生解决复杂工程问题能力为指引,基于新工科专业人才培养目标及人工智能技术在课堂教学中的功能定位,探索人工智能技术赋能“线性代数”课程教学的3条作用路径。同时,通过具体的教学案例展示人工智能技术作为“资源”“工具”“环境”与“线性代数”课程教学的3种整合方式,并基于新工科专业人才培养要求提出了“线性代数”课程教学中人工智能技术创新应用策略。

应用型本科院校“线性代数”教学改革探讨

"线性代数"是应用型本科院校工科专业的一门基础课程。在教学过程中,教师由于对课程任务认识不清晰,对专业需求认识不到位,对学生认识不全面,无法满足应用型本科院校人才培养的需求。在"线性代数"教学过程中,教师应整合教学内容,重新编排课程体系;将多媒体应用于教学中,强化学生的感性认识;增加实践环节,促进理论与应用的结合;创新教学模式,使用"项目教学+小组合作教学"的模式,提高学生的自主学习能力,并用Maple T.A.系统对学生进行评价,反馈学生的学习成果。

关于工科院校“线性代数”课程教改的若干思考

针对"线性代数"课程学生难学、教师难教的现实情况,试图从教材的建设、数学建模思想与"线性代数"课程的融合以及多媒体在课堂教学中的应用三个方面,讨论工科院校中"线性代数"课程的教学改革问题,同时提出了一些具体的改进建议。

Double-Pole Solution and SolitonAntisoliton Pair Solution of MNLSE/DNLSE Based upon Hirota Method

Hirota method is applied to solve the modified nonlinear Schrodinger equation/the derivative nonlinear Schrodinger equation(MNLSE/DNLSE) under nonvanishing boundary conditions(NVBC) and lead to a single and double-pole soliton solution in an explicit form. The general procedures of Hirota method are presented, as well as the limit approach of constructing a soliton-antisoliton pair of equal amplitude with a particular chirp. The evolution figures of these soliton solutions are displayed and analyzed. The influence of the perturbation term and background oscillation strength upon the DPS is also discussed.

Nonlinear Absorption and Low-threshold Two-photon Pumped Amplified Stimulated Emission from FAPbBr_(3) Nanocrystals

Formamidinium lead bromide(FAPbBr_(3))nanocrystals(NCs)have been considered to be a good optoelectronic material due to their pure green emission,excellent stability and superior carrier transport characteristics.However,two-photon pumped amplified spontaneous emission(ASE)and the corresponding nonlinear optical properties of FAPbBr_(3) NCs are scarcely revealed.Herein,we synthesized colloidal FAPbBr_(3) NCs with different sizes by changing the molar ratio of FABr/PbBr_(2) in the precursor solution,using ligand assisted precipitation(LARP)technology at room temperature.Photoluminescence(PL)and time resolved photoluminescence(TRPL)spectroscopy were measured to characterize their ASE properties.And their nonlinear optical properties were studied through the Zscan technique and the two-photon excited fluorescence method.The stimulated emission properties including oneand two-photon pumped ASE have been realized from FAPbBr_(3) NCs.With large two-photon absorption coefficient(0.27 cm/GW)and high non-linear absorption cross-section(7.52×10^(5) GM),ASE with threshold as low as 9.8μJ/cm^(2) and 487μJ/cm^(2) have been obtained from colloidal FAPbBr_(3) NCs using one-and two-photon excitations.These results indicate that as a new possible green-emitting frequency-upconversion material with low thresholds,FAPbBr_(3) NCs hold great potential in the development of high-performance two-photon pump lasers.

Strong Feller Property for SDEs with Super-linear Drift and Hölder Diffusion Coefficients

In this paper,we investigate the strong Feller property of stochastic differential equations(SDEs)with super-linear drift and Hölder diffusion coefficients.By utilizing the Girsanov theorem,coupling method,truncation method and the Yamada-Watanabe approximation technique,we derived the strong Feller property of the solution.

Influence of confined water on the limit support pressure of tunnel face in weakly water-rich strata

In the process of shield tunneling through soft soil layers,the presence of confined water ahead poses a significant threat to the stability of the tunnel face.Therefore,it is crucial to consider the impact of confined water on the limit support pressure of the tunnel face.This study employed the finite element method(FEM)to analyze the limit support pressure of shield tunnel face instability within a pressurized water-containing layer.Subsequently,a multiple linear regression approach was applied to derive a concise solution formula for the limit support pressure,incorporating various influencing factors.The analysis yields the following conclusions:1)The influence of confined water on the instability mode of the tunnel face in soft soil layers makes the displacement response of the strata not significant when the face is unstable;2)The limit support pressure increases approximately linearly with the pressure head,shield tunnel diameter,and tunnel burial depth.And inversely proportional to the thickness of the impermeable layer,soil cohesion and internal friction angle;3)Through an engineering case study analysis,the results align well with those obtained from traditional theoretical methods,thereby validating the rationality of the equations proposed in this paper.Furthermore,the proposed equations overcome the limitation of traditional theoretical approaches considering the influence of changes in impermeable layer thickness.It can accurately depict the dynamic variation in the required limit support pressure to maintain the stability of the tunnel face during shield tunneling,thus better reflecting engineering reality.

Model Order Reduction Methods for Discrete Systems via Discrete Pulse Orthogonal Functions

This paper explores model order reduction(MOR)methods for discrete linear and discrete bilinear systems via discrete pulse orthogonal functions(DPOFs).Firstly,the discrete linear systems and the discrete bilinear systems are expanded in the space spanned by DPOFs,and two recurrence formulas for the expansion coefficients of the system’s state variables are obtained.Then,a modified Arnoldi process is applied to both recurrence formulas to construct the orthogonal projection matrices,by which the reduced-order systems are obtained.Theoretical analysis shows that the output variables of the reducedorder systems can match a certain number of the expansion coefficients of the original system’s output variables.Finally,two numerical examples illustrate the feasibility and effectiveness of the proposed methods.

Linear and Nonlinear Ultrasonic Detections of Impact Damage in Composite Laminate

The appearance and accumulation of internal impact damage seriously influence overall performance of carbon fiber reinforced plastic(CFRP).Thus,this study evaluates the change in impact damage number by using linear and nonlinear ultrasonic Lamb wave detection methods,and compares these two detection results.An ultrasonic wave simulation model for composite structure with impact damage is established using the finite element method,and the interaction between impact damage and the ultrasonic wave is simulated.Simulation results demonstrate that the ultrasonic amplitude linearly decreases,and the relative nonlinear parameter linearly increases in proportion to the impact number,respectively.The linear-fitting slope of nonlinear parameter is 0.38 per impact number at an input frequency of 1.0 MHz.It is far higher than that of the linear ultrasonic amplitude,which is only-0.12.However,with the increase of impact damage,the linear growth of nonlinear parameters mainly depends on the decrease in ultrasonic amplitude rather than the accumulation of second harmonic amplitude.In the linear ultrasonic amplitude detection,the linear fitting slope at 1.1 MHz is-0.14,which is lower than those at 0.9 MHz and 1.0 MHz.Meanwhile,in the nonlinear ultrasonic parameter detection,the linear fitting slope at 1.1 MHz is 0.92,which is higher than those at 0.9 MHz and 1.0 MHz.The results show that higher frequencies lead to greater attenuation of ultrasonic amplitude and a larger increase in nonlinear parameters,which can enhance the sensitivity of both linear and nonlinear ultrasonic detections.The accuracy of simulation results is demonstrated through the low-velocity impact and ultrasonic experiments.The results show that compared with nonlinear ultrasonic technology,the linear ultrasonic technology is more suitable for impact damage assessment of carbon fiber reinforced plastic because of its simpler detection process and higher sensitivity.

Electrical and nonlinear optical properties of TGZO transparent conducting films deposited by magnetron sputtering

Thin transparent oxide conducting films(TCOFs)of titanium and gallium substituted zinc oxide(TGZO)were fabricated via radio frequency(RF)magnetron sputtering technique.The effects of RF power on electrical,linear and nonlinear optical characteristics were investigated by Hall tester,Ultraviolet(UV)-visible spectrophotometer and optical characterization method.The results indicate that RF power significantly influences the electrical and optical properties of the deposited films.As RF power raises,the resistivity and Urbach energy fall initially and then rise,while the figure of merit,mean visible transmittance and optical bandgap show the reverse variation trend.At RF power of 190 W,the TGZO sample exhibits the highest electro-optical properties,with the maximum figure of merit(1.14×10^(4)Ω^(-1)∙cm^(-1)),mean visible transmittance(86.9%)and optical bandgap(3.50 eV),the minimum resistivity(6.26×10^(-4)Ω∙cm)and Urbach energy(174.23 meV).In addition,the optical constants of the deposited films were determined by the optical spectrum fitting method,and the RF power dependence of nonlinear optical properties was studied.It is observed that all the thin films exhibit normal dispersion characteristics in the visible region,and the nonlinear optical parameters are greatly affected by the RF power in the ultraviolet region.

Impact of correlated private signals on continuous-time insider trading

A model of continuous-time insider trading in which a risk-neutral in-sider possesses two imperfect correlated signals of a risky asset is studied.By conditional expectation theory and filtering theory,we first establish three lemmas:normal corre-lation,equivalent pricing and equivalent profit,which can guarantee to turn our model into a model with insider knowing full information.Then we investigate the impact of the two correlated signals on the market equilibrium consisting of optimal insider trading strategy and semi-strong pricing rule.It shows that in the equilibrium,(1)the market depth is constant over time;(2)if the two noisy signals are not linerly correlated,then all private information of the insider is incorporated into prices in the end while the whole information on the asset value can not incorporated into prices in the end;(3)if the two noisy signals are linear correlated such that the insider can infer the whole information of the asset value,then our model turns into a model with insider knowing full information;(4)if the two noisy signals are the same then the total ex ant profit of the insider is increasing with the noise decreasing,while down to O as the noise going up to infinity;(5)if the two noisy signals are not linear correlated then with one noisy signal fixed,the total ex ante profit of the insider is single-peaked with a unique minimum with respect to the other noisy signal value,and furthermore as the noisy value going to O it gets its maximum,the profit in the case that the real value is observed.

Dynamics of Nonlinear Waves in(2+1)-Dimensional Extended Boiti-Leon-Manna-Pempinelli Equation

Based on the Hirota bilinear method,this study derived N-soliton solutions,breather solutions,lump solutions and interaction solutions for the(2+1)-dimensional extended Boiti-Leon-Manna-Pempinelli equation.The dynamical characteristics of these solutions were displayed through graphical,particularly revealing fusion and ssion phenomena in the interaction of lump and the one-stripe soliton.

Several Classes of Two-weight or Three-weight Linear Codes and Their Applications

Recently,linear codes with a few weights have been extensively studied due to their applications in secret sharing schemes,constant composition codes,strongly regular graphs and so on.In this paper,based on the Weil sums,several classes of two-weight or three-weight linear codes are presented by choosing a proper defining set,and their weight enumerators and complete weight enumerators are determined.Furthermore,these codes are proven to be minimal.By puncturing these linear codes,two classes of two-weight projective codes are obtained,and the parameters of the corresponding strongly regular graph are given.This paper generalizes the results of[7].

On the Local Convergence and Dynamics of New Iterative Method with Sixth Order Convergence

In this paper,we construct a new sixth order iterative method for solving nonlinear equations.The local convergence and order of convergence of the new iterative method is demonstrated.In order to check the validity of the new iterative method,we employ several chemical engineering applications and academic test problems.Numerical results show the good numerical performance of the new iterative method.Moreover,the dynamical study of the new method also supports the theoretical results.