高校科技期刊的业务流程再造实践——以《中国有色金属学报》为例

【目的】 在媒体融合的背景下,探索高校科技期刊获得良性、可持续发展的业务流程再造方案。【方法】 通过问卷调查法和深度访谈法,对《中国有色金属学报》学术用户的实际需求进行诊断分析,并依据《中国有色金属学报》一年内的业务流程再造实践,总结和设计普适性较强的高校科技期刊业务流程再造方案。【结果】 《中国有色金属学报》在学术用户群体服务与管理、学术资源挖掘和利用、缩短出版周期和媒体融合等方面进行业务流程再造并取得了显著成效。【结论】 高校科技期刊要想谋求新的发展和突破,必须基于用户日益增长的学术需求进行业务拓展,同时基于技术和机制,与时俱进地进行业务流程再造。     

Numerical Integrators for Dispersion-Managed KdV Equation

In this paper, we consider the numerics of the dispersion-managed Korteweg-de Vries (DM-KdV) equation for describing wave propagations in inhomogeneous media. The DM-KdV equation contains a variable dispersion map with discontinuity, which makes the solution non-smooth in time. We formally analyze the convergence order reduction problems of some popular numerical methods including finite difference and time-splitting for solving the DM-KdV equation, where a necessary constraint on the time step has been identified. Then, two exponential-type dispersion-map integrators up to second order accuracy are derived, which are efficiently incorporated with the Fourier pseudospectral discretization in space, and they can converge regardless of the discontinuity and the step size. Numerical comparisons show the advantage of the proposed methods with the application to solitary wave dynamics and extension to the fast & strong dispersion-management regime.     

Convergence and attractivity of memristor-based cellular neural networks with time delays

This paper presents theoretical results on the convergence and attractivity of memristor-based cellular neural networks (MCNNs) with time delays. Based on a realistic memristor model, an MCNN is modeled using a differential inclusion. The essential boundedness of its global solutions is proven. The state of MCNNs is further proven to be convergent to a critical-point set located in saturated region of the activation function, when the initial state locates in a saturated region. It is shown that the state convergence time period is finite and can be quantitatively estimated using given parameters. Furthermore, the positive invariance and attractivity of state in non-saturated regions are also proven. The simulation results of several numerical examples are provided to substantiate the results.     

A Hodge Decomposition Method for Dynamic Ginzburg–Landau Equations in Nonsmooth Domains — A Second Approach

In a general polygonal domain, possibly nonconvex and multi-connected (with holes), the time-dependent Ginzburg–Landau equation is reformulated into a new system of equations. The magnetic field $B$:=∇×A is introduced as an unknown solution in the new system, while the magnetic potential A is solved implicitly through its Hodge decomposition into divergence-free part, curl-free and harmonic parts, separately. Global well-posedness of the new system and its equivalence to the original problem are proved. A linearized and decoupled Galerkin finite element method is proposed for solving the new system. The convergence of numerical solutions is proved based on a compactness argument by utilizing the maximal $L^p$-regularity of the discretized equations. Compared with the Hodge decomposition method proposed in [27]_,the new method has the advantage of approximating the magnetic field B directly and converging for initial conditions that are incompatible with the external magnetic field. Several numerical examples are provided to illustrate the efficiency of the proposed numerical method in both simply connected and multi-connected nonsmooth domains. We observe that even in simply connected domains, the new method is superior to the method in [27] for approximating the magnetic field.     

Transforming vaccine development

The urgency to develop vaccines against Covid-19 is putting pressure on the long and expensive development timelines that are normally required for development of lifesaving vaccines. There is a unique opportunity to take advantage of new technologies, the smart and flexible design of clinical trials, and evolving regulatory science to speed up vaccine development against Covid-19 and transform vaccine development altogether.     

王国华主任医师治疗凌晨早醒型失眠

在中西医结合理论的指导下,论证运用病证结合方法防治肺心脑共病的独特优势。肺心脑共病是老年患病人群的常见特点。这一疾病有着共同的致病机制,严重影响老年人的生活质量,而临床常见的导致老年人肺心脑共病的原因有很多,症状也不相类似。通过分析肺朝百脉、心主血脉与脑供血的关系,论述了肺、心、脑同治以治疗失眠的可行性,并结合临床多年经验,总结其治疗的经验方法,经过肺心脑同治的中药治疗之后,患者临床症状得到改善。     

彩色多普勒血流会聚法定量评估二尖瓣返流严重程度的研究

彩色多普勒血流会聚区（ＦＣＲ）法是近几年发展起来的一定量二尖瓣返流的新方法。本文应用该方法，对５５例显示血流会聚区的二尖瓣返流患者行ＦＣＲ法与返流束面积法（ＳＲ）、返流束面积与左房面积之比法（ＳＲ／ＳＬＡ）相比较，相关系数分别为０．８２２及０．７３２（Ｐ值均小于０．０１），并应用ＦＣＲ法定量测定二尖瓣返流率。按不同的返流率将二尖瓣返流分为轻、中、重三度。本文认为血流会聚法为定量评估二尖瓣返流（特别是中至重度返流）一较为理想的无创性方法，具有广泛的理论研究及临床应用前景。     

不同的向会聚度对Finesse全瓷冠的适合性影响的研究

目的:评估不同的向会聚度对Finesse全瓷冠适合性的影响,为临床应用提供理论依据。方法:在向会聚度分别为5°、10°、15°的超硬人造石代型上分别制作全瓷冠各10个,粘结(玻璃离子3.5kg静止固位力)、包埋、片切。以体式显微镜测量边缘适合性AMO,边缘浮升量PMO,轴壁适合性AWA,面适合性OA,通过单因素方差和q检验,进行统计分析。结果:各组的边缘适合性均在临床要求范围内。5°组、10°组、15°组的AMO分别为109!m、66"m、69#m;5°组与10°组、15°组的AMO,PMO,OA相比较时存在显著性差异(P<0.05),10°组与15°组无显著性差异(P>0.05)。结论:Finesse热压铸型陶瓷冠具有良好的适合性,能满足临床应用要求。为保证较高的适合性,临床应采用10°到15°的牙体预备。     

Convergence Rate Analysis for Deep Ritz Method

Using deep neural networks to solve PDEs has attracted a lot of attentions recently. However, why the deep learning method works is falling far behind its empirical success. In this paper, we provide a rigorous numerical analysis on deep Ritz method (DRM) [47] for second order elliptic equations with Neumann boundary conditions. We establish the first nonasymptotic convergence rate in $H^1$ norm for DRM using deep networks with ${\rm ReLU}^2$ activation functions. In addition to providing a theoretical justification of DRM, our study also shed light on how to set the hyperparameter of depth and width to achieve the desired convergence rate in terms of number of training samples. Technically, we derive bound on the approximation error of deep ${\rm ReLU}^2$ network in $C^1$ norm and bound on the Rademacher complexity of the non-Lipschitz composition of gradient norm and ${\rm ReLU}^2$ network, both of which are of independent interest.