SARS疫情分析及对北京疫情走势的预测

在考虑每个SARS病人每日平均传染概率和他的直接传染的平均期限的基础上，建立了一个统计分析模型．分析表明，每个病人可以造成直接感染他人的期限平均在20天左右，这个值在不同地区和不同疫情阶段似乎变化不大．病人的平均每天感染率与社会状况有关，在疫情爆发期较大，在疫情控制期要小很多．北京后期如果控制在香港后期的感染率水平上，则有望在6月上中旬下降到日增几例．然后再经过约一个月，即7月上中旬达到日增0病例，而累积总病例数将达到3100多．但如果北京的新病例下降速度与广东类似的话，则要再多花至少一个月，才能达到上述的效果，且累积总病例数会达到3800左右．     

新型冠状病毒肺炎疫情确诊病例的统计分析及自回归建模

基于安徽省卫生健康委员会截至2020年2月19日公布的800余例新型冠状病毒肺炎病例信息,根据病例中公布的接触史构建确诊患者间的有向传播关系,发现源传染患者中男性居多,被传染患者中女性居多.从病例信息中可知,安徽省新型冠状病毒肺炎疫情的发展从初期的具有武汉居住或接触史的输入病例转入后期本地传播为主的小范围社区传播,且严格的防控隔离措施有效切断了社区内的进一步传播.源传染患者与被传染患者的确诊时间间隔可用G分布拟合,确诊时间间隔的中位数为2 d,平均值为2.67 d.基于有向传播关系的统计特点,构建安徽省疫情发展后期的自回归传播模型,模型仿真结果与疫情发展数据符合.对除湖北省的全国确诊病例数据同样采取自回归建模与仿真,结果仍与疫情发展数据符合.这一发现为控制疫情在湖北省以外区域的防控提供了参考:通过严格的防控措施和隔离措施,疫情在湖北省之外的传播具有很大的黏滞性,多为家庭程度的密切接触传播,且能有效控制新型冠状病毒肺炎在当地的传播深度,有效控制了疫情的蔓延.     

一、粒子物理实验

2003年1月1日至5月17日，北京谱仪进行ψ”实验取数，主要完成了：ψ”峰位上取数，束流能量Eb=1．8857GeV，累计积累33．7pb。1物理数据；ψ’，峰位精细扫描；共振峰外取数，束流能量Eb=1．8246GeV(数据用于e e^-湮灭为连续态强子过程的研究和ψ”、ψ’物理中的本底研究)。     

关于亨德里克·舒恩及其论文共同署名作者在科学工作中不端行为可能性的调查委员会报告的前言部分

2002年5月下旬,贝尔实验室的管理部门组成了一个专门委员会,为了调查“在Schn Hendrik(以下称舒恩)等人发表的论文中科学不端行为的可能性,其数据的真实性以及在形成论文的过程中是否使用了适当的科学方法”.委员会的成员是Beasley M R(委员会主席),Datta S, Kogelnik H, Kroemer H和Monroe D.委员会的第一项任务是确定来自各方面的指控.由于某些指控已被公开,并且在调查的过程中委员会发现又有新的指控,该任务变得错综复杂.起始阶段的工作于2002年6月20日结束.列出的指控指向以舒恩为第一作者的25篇文章,涉及到20位共同署名作者.在…     

考虑出行行为调整的疫情传播模型与新冠疫情预测

由于新冠病毒不断变异,在很长的时期内疫情会多次爆发,每次有不同的特点.对局部地区爆发的每一波疫情进行预测,成为人们制定应对策略的关键.在宏观层面对疫情防控措施优化,意味着疫情演化数据的缺乏,这给基于实证数据的疫情预测带来了特殊的困难.考虑疫情与出行行为的相互影响,本文提出了一个改进的虫口模型,用以描述新冠疫情传播动力学过程,试图利用少量疫情相关数据对局部地区爆发的某一特定疫情进行预测.实证分析表明,该模型可以很好地复现上海市2022年3月1日到6月28日发布的新冠病毒阳性感染者数据.采用这一模型对上海市2022年12月以来的疫情趋势和关键节点进行了预测.建议决策部门按照统计学抽样原则,建立和完善疫情监测系统,为疫情预测提供可靠的数据.     

PS-InSAR技术在北京平原区地面沉降监测中的应用研究

北京市近60年长期超量开采地下水已经引起了严重的地下水水位下降和大范围地面沉降,截止到2009年最大累计沉降量达到1 096 mm,并以30~60 mm·y-1速率扩展,严重威胁城市规划建设和人民交通安全。相对于传统的水准测量、分层标等地面沉降监测手段,永久散射体干涉测量技术(PS-InSAR)可以快速获取高分辨率的地表形变细节信息。利用PS-InSAR技术和2003年12月—2009年3月Envisat卫星29景ASAR影像监测北京平原区地面沉降发展情况,发现北京平原区沉降漏斗已连成一片,沉降梯度变化较大地区主要分布在北京第四系凹陷区,覆盖面涉及朝阳、昌平、顺义、通州等区县,并有东移外扩趋势,平谷县境内出现新的沉降中心。沉降分布受前门—良乡—顺义、黄庄—高丽营、南口—孙河等主要断层控制,地面沉降与地下水水位变化具有明显相关性,呈现季节性下降(3月—6月)与回弹(11月—3月)趋势,并受弱透水层应力应变本构关系(弹性-塑性-黏弹性)影响。     

评估新型冠状病毒地区防控效果的一种近似方法

我们观察到地区累计确诊的病例数目和武汉封城前流入的人口总数高度相关,且本地第三代感染者占比很小.基于此,提出了一种考虑输入病例和地区人口效应的定量化评估新型冠状病毒地区防控效果的近似方法,并将其用于评估武汉流出人口前50的城市防控的成效.防控效果最显著的10个城市依次是石家庄、洛阳、恩施、周口、厦门、贵阳、咸宁、安庆、信阳、南宁.     

激光雷达探测北京城区夏季大气边界层

为了研究北京城区夏季大气边界层结构变化特征及大气边界层内气溶胶消光特性,2004年8月利用便携式米散射激光雷达对北京城区夏季大气边界层进行了系统观测。反演了观测站上空大气气溶胶的消光特性垂直分布以及大气边界层的高度。分析了气象条件和人类活动对大气边界层结构的影响。观测数据表明： 北京城区夏季大气边界层有明显的日变化特征,早晚比较低,日间有一个从低变高再变低的过程,中午前后达到最高。结合气象参数对测量数据进行的统计分析表明：北京城区夏季大气边界层高度相对稳定,多分布在1.8km以下,平均值为0.68km;大气边界层内存在浓度较高的气溶胶粒子,平均光学厚度（3km以内）在0.30左右。     

密集波分复用薄膜滤光片的群延迟补偿设计

设计了一种基于薄膜干涉理论的反射式相位补偿器件，用以补偿密集型波分复用窄带滤光片所产生的群延迟，使50GHz薄膜滤光片的群延迟特性适应于40Gb／s系统的要求，在0．2nm带宽下群延迟波动从10ps左右下降到0．76ps以下。     

封底照片说明

今年6月北京时间21日23时15分，由62岁的南非人迈克尔·梅尔韦尔驾驶的“太空船一号”飞行器，平安降落在位于加利福尼亚州莫哈韦沙漠的机场，从而成功完成了私人投资建造太空器的首次太空飞行。在机场上，迈克尔·梅尔韦尔受到飞船设计者伯特·鲁坦等数千人的热烈欢迎。在这次飞行中，     

Discovery of a missing disease spreader

This study presents a method to discover an outbreak of an infectious disease in a region for which data are missing, but which is at work as a disease spreader. Node discovery for the spread of an infectious disease is defined as discriminating between the nodes which are neighboring to a missing disease spreader node, and the rest, given a dataset on the number of cases. The spread is described by stochastic differential equations. A perturbation theory quantifies the impact of the missing spreader on the moments of the number of cases. Statistical discriminators examine the mid-body or tail-ends of the probability density function, and search for the disturbance from the missing spreader. They are tested with computationally synthesized datasets, and applied to the SARS outbreak and flu pandemic.     

Modelling the spreading rate of controlled communicable epidemics through an entropy-based thermodynamic model

A model based on a thermodynamic approach is proposed for predicting the dynamics of communicable epidemics assumed to be governed by controlling eforts of multiple scales so that an entropy is associated with the system.All the epidemic details are factored into a single and time-dependent coefcient,the functional form of this coefcient is found through four constraints,including notably the existence of an inflexion point and a maximum.The model is solved to give a log-normal distribution for the spread rate,for which a Shannon entropy can be defined.The only parameter,that characterizes the width of the distribution function,is uniquely determined through maximizing the rate of entropy production.This entropy-based thermodynamic(EBT)model predicts the number of hospitalized cases with a reasonable accuracy for SARS in the year 2003.This EBT model can be of use for potential epidemics such as avian influenza and H7N9 in China.     

BESIII 实验对奇特态 X(3872) 的研究

量子色动力学允许超出夸克模型中重子和介子的奇特态的存在。对奇特态的研究是当前高能物理实验的热门话题之一。X(3872)是第一个被实验上观测到的奇特态候选者。实验和理论上对X(3872)的研究从未间断,这使得X(3872)成为了解最好的奇特态。运行在北京正负电子对撞机(BEPCII)上的北京谱仪(BESIII)实验积累了大量的质心能量从3.87 到 4.70 GeV的正负电子对撞数据样本。利用这些数据样本,得到了很多关于X(3872)的实验结果。本文将回顾BESIII上关于X(3872)所取得一系列成果及最新实验进展。对X(3872)等奇特态的研究,将有利于我们对自然界的基本相互作用的理解,也将促进标准模型理论的完善。     

Application of Raman dispersion spectroscopy in 3‐way multivariate data analysis

In this paper a new application of Raman dispersion spectroscopy (RADIS) is proposed, namely as a source of 3‐way data in multivariate analysis of classification problems, i.e. problems where different molecular species are identified in a number of samples. Owing to the coherent nature of the absorption–emission sequence in the Raman process, the unpolarized data generated by RADIS are born as 3‐way multivariate data. To demonstrate the potential of RADIS, a series of classification problems have been constructed and analyzed. By using computer‐simulated Raman and RADIS data it is shown that the 3‐way RADIS data obtained from very few samples, using only a few laser frequencies and a few Raman bands, can in general provide highly reliable results in classification problems without any a priori knowledge about the number of different molecular species in the samples. Quantitative comparisons have been made between a principal component analysis (PCA) of the 2‐way Raman data and a Tucker 3 analysis of the corresponding 3‐way RADIS data. It is found that the 3‐way RADIS data will give rise to a recognition ratio equal to 100% even in the worst case where no conclusions about the number of different molecular species in the samples can be drawn from the PCA of the 2‐way Raman data. It is shown that only the raw RADIS data are needed for the multivariate analysis, so that the use of internal standards, corrections for self‐absorption and other corrections necessary in molecular dynamics problems can be avoided. The results do not depend very much on the particular excitation wavenumbers used. Furthermore in most cases the fluorescence background does not influence the results. These facts together with the increased availability of solid state lasers with a variety of wavenumbers makes it easy to implement the proposed application of RADIS in practice. Copyright © 2007 John Wiley & Sons, Ltd.     

基于安卓平台的糖尿病监护系统的研究及实现

基于目前针对糖尿病的研究主要集中在健康管理及血糖浓度监测方面,在糖尿病病情控制方面并不乐观的现状,设计开发了一套能够实时监护老年患者注射药物情况的远程家庭医疗系统。该系统由智能检测硬件系统,手机客户端和WEB信息管理端组成,不仅可以解决独孤老人时常忘记注射胰岛素的问题,也有利于解决我国老年患者糖尿病监护难的问题,同时也能提醒青壮年实时携带注射针剂盒,缓解糖尿病并发症的发生。通过实时实验测试,该糖尿病监护系统可靠、稳定,且具有良好的实际应用价值。     

Approximations of inverse boundary element methods with partial measurements of the pressure field

Boundary element methods (BEMs) based near-field acoustic holography (NAH) requires the measurement of the pressure field over a closed surface in order to recover the normal velocity on a nearby conformal surface. There are practical cases when measurements are available over a patch from the measurement surface in which conventional inverse BEM based NAH (IBEM) cannot be applied directly, but instead as an approximation. In this work two main approximations based on the indirect-implicit methods are considered: Patch IBEM and IBEM with Cauchy data. Patch IBEM can be applied with a continuation procedure, which as its predecessor patch NAH (a well known technique that can be used on separable geometries of the wave equation) continues the pressure field using an iterative procedure, or it can be applied by a direct procedure. On the other hand, IBEM with Cauchy data requires measurements over two conformal patches and it will be shown that this technique will be reliable regardless of the position of the source. The theory behind each method will be justified and validated using a cylindrical surface with numerical data generated by point sources, and using experimental data from a cylindrical fuselage excited by a point force.     

Molecular modelling in structural biology

Molecular modelling is a powerful methodology for analysing the three dimensional structure of biological macromolecules. There are many ways in which molecular modelling methods have been used to address problems in structural biology. It is not widely appreciated that modelling methods are often an integral component of structure determination by NMR spectroscopy and X-ray crystallography. In this review we consider some of the numerous ways in which modelling can be used to interpret and rationalise experimental data and in constructing hypotheses that can be tested by experiment. Genome sequencing projects are producing a vast wealth of data describing the protein coding regions of the genome under study. However, only a minority of the protein sequences thus identified will have a clear sequence homology to a known protein. In such cases valuable three-dimensional models of the protein coding sequence can be constructed by homology modelling methods. Threading methods, which used specialised schemes to relate protein sequences to a library of known structures, have been shown to be able to identify the likely protein fold even in cases where there is no clear sequence homology. The number of protein sequences that cannot be assigned to a structural class by homology or threading methods, simply because they belong to a previously unidentified protein folding class, will decrease in the future as collaborative efforts in systematic structure determination begin to develop. For this reason, modelling methods are likely to become increasingly useful in the near future. The role of the blind prediction contests, such as the Critical Assessment of techniques for protein Structure Prediction (CASP), will be briefly discussed. Methods for modelling protein-ligand and protein-protein complexes are also described and examples of their applications given.     

同时采用三种方法测定热痛灵注射液中二组分的含量

本文经选择适当的测定波长，同时采用多波长直线回归，Ｐ－矩阵法和联立方程组新解法测定热痛灵注射液的含量。三咱方法简便、快速、准确，样品测定结果均和北京市药品标准法测定结果一致。     

Orthogonal contributor number for the measurement of sound power

Orthogonal contributors to a global error represent a very efficient design method in terms of both sensing and control of noise radiation. In practice the price of a sensing system will be determined by the number of errors it must resolve. Therefore predicting the most efficient way of measuring radiation power is an important problem. Recently work has compared sensing the number of vibration modes to the number of orthogonal contributors to radiated power. The required number of vibration modes was based on the proximity of the structural mode resonance frequency and the excitation frequency. While ultimately this technique will result in a valid estimate of radiated power, it is shown here that the number of structural modes can be minimized by first considering orthogonal radiators based on structural mode amplitudes. Two disturbance cases are considered: a point force and an even disturbance coupling to each structural mode. Also, under these conditions the practicality of estimating the number of orthogonal radiators when it is assumed that each contributor is equal in amplitude is examined. Finally in an attempt to optimism the number of signals to be sensed, a variable error margin for the estimate of power, based on the ratio of the sound power at each frequency to the maximum peak in the considered frequency range is proposed and analyzed.