微带传输线束流信号展宽处理设计

对束流信号进行展宽处理是储存环逐束团位置测量RF前端设计的重要工作之一。针对上海光源储存环束流信号的特点，对束流信号展宽进行分析，采用低通滤波器和包络检波联合的方法对信号进行展宽。考虑到实现过程需要对信号进行ps量级的延时，使用微带传输线对该方法进行了具体设计。对微带传输线等效为集总参数LC元件进行推导以进行低通滤波器设计，给出了阻抗匹配方案以实现宽带功率分配器与合成器。仿真和实测结果表明，所设计的电路能够对束流信号进行有效展宽处理。     

次声波的物理性质及其应用

我们对次声波在不同介质中传播的物理性质进行整理, 结合近年来相关研究成果进行分析, 此外对产 生次声波的声源进行整理, 对其在次声监测等领域的应用进行综述, 对产生次声波的多种方法进行整理. 较全面地 刻画出次声波物理性质的真实图景, 对引导人们以客观理性的态度认识次声波很有意义     

基于MATLAB的RC串联电路暂态过程仿真

对RC串联电路暂态过程进行了研究,并对其进行了理论分析,最后利用MATLAB的绘图功能,对实验现象进行了仿真,仿真结果与实验相符.     

大学物理实验数据的计算机估算与管理

本较详尽地介绍了大学物理实验数据的计算机估算与管理系统。它不仅能够对大学物理实验所测数据进行快速估算和对不确定度的估计处理,而且能够对实验数据进行保存、修改、调用等管理性操作。同时对学员的实验结果进行及时有效地评估。对计算机应用于实验教学进行了探讨。     

向列相液晶中空间光孤子的研究进展

对向列相液晶中空间光孤子产生机制进行了详细的阐述，并对其目前的研究进展进行了概括介绍。最后，对它们的应用前景进行了展望。     

热物理激光测量中的三维温度场重构方法

针对热物理激光测量中的三维温度场重构问题，进行了几种算法的讨论．对双高斯函数形式的温度分布进行了重构计算，对重构算法进行了检验，对实验过程中可能出现的误差进行了模拟，讨论了它们对重构结果的影响．     

超声清洗槽内空化强度的测量

对洗涤槽内超声空化的相对强度及其分布进行了研究。采用铝箔腐蚀法,应用图像、数据处理软件对试验结果进行处理,最后对实验结果进行了讨论。     

基于Kinect深度数据的移动机器人障碍检测方法研究

（北方工业大学,机械与材料工程学院,北京,100144） 摘要： 未知室内环境中的障碍检测是室内移动机器人领域的热点问题。在低成本条件下为更加准确的对环境中的障碍进行检测,提出一种基于低成本Kinect传感器点云数据进行环境障碍检测的有效方法。首先通过Kinect三维点云数据,对点云数据进行去燥处理,并进行三维数据到二维平面的投影的转换并通过DBSCAN聚类算法对投影的二维点云数据进行聚类分析。通过设置相邻顶点间最大距离阈值对convex-hull凸包算法进行改进,试验结果表明改进的凸包算法能够对障碍进行有效识别。该方法在Matlab中进行了方法验证,并在P3-DX移动机器人平台上进行了试验验证,结果表明该方法能够有效对环境中的障碍进行有效识别。     

学生物理思想在高中物理教学中的培养

在高中物理教学过程中,物理思想的培养是其主要教学目标,掌握一定的物理思想不但有助于对物理学习成绩进行提高,同时还可以帮助学生对一些物理方法进行掌握,从而对学生物理意识进行一定的培养。下面本文就对学生物理思想在高中物理教学中的培养进行探讨。     

互动教学在初中物理课堂教学中的应用

互动教学可以进一步提高学生的学习兴趣,对其课堂参与积极性进行提升,从而对其课堂教学质量进行有效的提高.下面本文就对互动教学在初中物理课堂教学中的有效应用进行分析.     

Correlation dimension analysis and capillary wave turbulence in Dragon-Wash phenomena

This paper describes the evolution of surface capillary waves of deep water excited by gradually increasing the lateral external force at a single frequency. The vertical velocities of the water surface are measured by using a Polytec Laser Vibrometer with a thin layer of aluminium powder scattering on the surface to reflect the laser beam. Nonlinear interaction processes result in a stationary Fourier spectrum of the vertical surface velocities （the same as the surface elevation）, i.e. Iω -ω^-3-5. The observed spectrum can be interpreted as a wave-turbulent Kolmogorov spectrum for the case of ‘narrowband pumping＇ for a direct cascade of energy. Correlation dimension analysis of the whole development process reveals four distinct stages during the wave structure development and identifies the wave turbulence stage.     

铁磁-p波超导结中的自旋极化隧道谱与散粒噪声

考虑到界面的势垒散射和铁磁层中的磁交换作用，依照Sr2RuO4超导体具有自旋三重配对态的p波对称结构，研究铁磁-p波超导结中的自旋极化隧道谱与散粒噪声，研究表明：1.对于幺正配对态，随着铁磁层中磁交换劈裂增强，隧道谱与散粒噪声都减少；2.对于非幺正配对态，隧道谱与散粒噪声都依赖于铁磁层的磁化轴方向，当磁化轴平行于非幺正配对态的自旋轴时，在低偏压下磁交换作用能使隧谱与散粒噪声增强，而当磁化轴反平行于自旋转轴时，其结果相反。     

Uncertainty study of Bd(Bs)→ γν \bar{ν} Decays

B⁰(B_s) → γν\bar{ν} decays are useful to determining the decay constants f_B(f_{B_{s}}) and B(B_s) meson wave function. Using the B meson wave function determined in hadronic B(B_s) decays, we study the uncertainties due to the types of B meson wave functions. We find that the branching ratios are sensitive to the type of wave functions and input parameters, but the energy spectrum is independent. The predicted branching ratios are (0.45-1.04)× 10^-9 and (2.14-3.27)×10^-8 for B⁰ and B_s decay, respectively.     

Solving Schrodinger equations using a physically constrained neural network

Deep neural networks (DNNs) and auto differentiation have been widely used in computational physics to solve variational problems. When a DNN is used to represent the wave function and solve quantum many-body problems using variational optimization, various physical constraints have to be injected into the neural network by construction to increase the data and learning efficiency. We build the unitary constraint to the variational wave function using a monotonic neural network to represent the cumulative distribution function (CDF) \begin{document}$F(x) = \int_{-\infty}^{x} \psi^*\psi {\rm d}x'$\end{document}. Using this constrained neural network to represent the variational wave function, we solve Schrodinger equations using auto-differentiation and stochastic gradient descent (SGD) by minimizing the violation of the trial wave function \begin{document}$ \psi(x) $\end{document} to the Schrodinger equation. For several classical problems in quantum mechanics, we obtain their ground state wave function and energy with very low errors. The method developed in the present paper may pave a new way for solving nuclear many-body problems in the future.     

Study on wave packet dynamics of E~1Σ_g~+ state of Li_2 with femtosecond-resolved photoelectron spectra

Wave packet dynamics of the Li₂ molecule are investigated by using the time-dependent quantum wave packet method, and the time-resolved photoelectron spectra of the Li₂ molecule are calculated. The time-resolved wave packet theory is used to reasonably interpret the phenomena of the photoelectron spectra for different parameters. Our calculation shows that the loss of the wave packets in the shelf state area of E{ }^1\Sigma_g^ + plays a prominent role in the process of photoionization with the increase of the delay time. Moreover, the oscillation of the wave packet on the E{ }^1\Sigma_g^ + curve symbolizes a decreasing process of energy.     

Antiproton-proton annihilation at rest intoπ + π − η ′ andπ + π − η from atomicS andP states

We have measured the branching ratios for \(\bar pp\) annihilation at rest intoπ ⁺ π ^? η andπ ⁺ π ^? η′ in hydrogen gas in two data samples that have different fractions ofS-wave andP-wave initial states. The branching ratios are derived from a comparison with the topological branching ratio for \(\bar pp\) annihilations into four charged pions of (49±4)% and the branching ratio intoπ ⁺ π ^? π ⁺ π ^? π ⁰ of (18.7±1.6)%. We find a significant reduction of the branching ratios fromP-states for \(\bar pp \to \pi ^ + \pi ^ - \eta \) andπ ⁺ π ^? η′ in comparison toS-state annihilation. $$\begin{gathered} BR(S - wave \to \pi ^ + \pi ^ - \eta ) = (13.7 \pm 1.46) \cdot 10^{ - 3} \hfill \\ BR(P - wave \to \pi ^ + \pi ^ - \eta ) = (3.35 \pm 0.84) \cdot 10^{ - 3} \hfill \\ BR(S - wave \to \pi ^ + \pi ^ - \eta ') = (3.46 \pm 0.67) \cdot 10^{ - 3} \hfill \\ BR(P - wave \to \pi ^ + \pi ^ - \eta ') = (0.61 \pm 0.33) \cdot 10^{ - 3} . \hfill \\ \end{gathered} $$ In a partial wave analysis of theπ ⁺ π ^? η Dalitz plot we find the following contributions: Phase space, \(a_2^ + (1320)\pi ^ \mp \) ,ηρ⁰ andf ₂(1270)η: $$\begin{gathered} BR(S - wave \to \pi ^ + \pi ^ - \eta PS) = (6.31 \pm 1.22) \cdot 10^{ - 3} \hfill \\ BR(P - wave \to \pi ^ + \pi ^ - \eta PS) = (0.47 \pm 0.26) \cdot 10^{ - 3} \hfill \\ BR(^1 S_0 \to a_2^ \pm (1320)\pi ^ \mp ) = (2.59 \pm 0.73) \cdot 10^{ - 3} \hfill \\ BR(^3 S_1 \to a_2^ \pm (1320)\pi ^ \mp ) = (1.31 \pm 0.48) \cdot 10^{ - 3} \hfill \\ BR(P - wave \to a_2^ \pm (1320)\pi ^ \mp ) = (1.31 \pm 0.69) \cdot 10^{ - 3} \hfill \\ BR(^3 S_1 \to \rho \eta ) = (3.29 \pm 0.90) \cdot 10^{ - 3} \hfill \\ BR(^1 P_1 \to \rho \eta ) = (0.94 \pm 0.53) \cdot 10^{ - 3} \hfill \\ BR(^1 S_0 \to f_2 (1270)\eta ) = (0.083 \pm 0.086) \cdot 10^{ - 3} \hfill \\ BR(P - wave \to f_2 (1270)\eta ) = (0.64 \pm 0.26) \cdot 10^{ - 3} . \hfill \\ \end{gathered} $$ We find a 2 σ effect for the reaction \(\bar pp \to a_0^ \pm (980)\pi ^ \mp \) , \(a_0^ \pm \to \eta \pi ^ \pm \) , with a branching ratio of (0.13±0.07)·10^?3. For η' production we give a branching ratio of \(\bar pp \to \rho \eta '\) of (1.81±0.44)·10^?3 from³ S ₁. We estmate a contribution of about 0.3·10^?3 for ρη' fromP-states. The ratio of ρη and ρη' rpoduction is used to test the validity of the quark line rule. In theπ ⁺ π ^? π ⁺ π ^? γ final state we do not observe the reaction \(\bar pp \to \pi ^ + \pi ^ - \omega \) , ω→π ⁺ π ^? λ and derive an upper limit of 3·10^?3 for decay modeω→π ⁺ π ^? λ.     

New exact periodic solutions to （2＋1）-dimensional dispersive long wave equations

In this paper, we make use of the auxiliary equation and the expanded mapping methods to find the new exact periodic solutions for （2＋1）-dimensional dispersive long wave equations in mathematical physics, which are expressed by Jacobi elliptic functions, and obtain some new solitary wave solutions （m → 1）. This method can also be used to explore new periodic wave solutions for other nonlinear evolution equations.     

Theoretical study of the influence of intense femtosecond laser field on the evolution of the wave packet and the population of NaRb molecule

Employing the two-state model and the time-dependent wave packet method, we have investigated the influences of the parameters of the intense femtosecond laser field on the evolution of the wave packet, as well as the population of ground and double-minimum electronic states of the NaRb molecule. For the different laser wavelengths, the evolution of the wave packet of 6{ }^1\Sigma ^ + state with time and internuclear distance is different, and the different laser intensity brings different influences on the population of the electronic states of the NaRb molecule. One can control the evolutions of wave packet and the population in each state by varying the laser parameters appropriately, which will be a benefit for the light manipulation of atomic and molecular processes.     

Existence and Completeness of the Wave Operators for Higher Order Differential Operators

The aim of the present paper is to study the existence and the completeness of the wave operators for elliptic operators of higher order (Schr?dinger operator) with short-range potential of the form: and other related results by using the trace class method. MSC: 2000 46N50, 47Dxx, 47F05.