关于溶液中乙醇C—C—O伸缩振动的频率移动效应的研究

本文报道作者发现乙醇分子的 C—C—O 对称伸缩振动谱带的中心波数,在水溶液中随乙醇含量的增减而发生移动的实验规律;应用介电理论对乙醇分子 C—C—O 对称伸缩振动的频率移动效应作唯象说明的研究。

移动假日效应调整对春节影响月份的出院病例数预测效果研究

目的对比用原始出院人数序列预测的直接预测值与调整移动春节效应后序列的调整预测值对春节影响月份的预测效果。方法采用时间序列ARIMA模型进行预测研究。用移动假日效应调整方法进行出院人数移动春节效应的调整,并根据均值预测值和预测年份的调整差值计算得出调整预测值。结果两次预测的预测模型相同,均为ARIMA(1,(1,12),1)模型。2013年2月调整预测的相对预测误差为0.4%,其绝对值显著小于实际预测的相对预测误差(-13.58%)的绝对值。结论移动春节效应严重影响了春节效应月份的预测效果。调整移动春节效应后的调整预测值与实际值更为接近。

考虑移动假日效应的中国月度数据的季节调整

文章基于X-13-ARIMA-SEATS模型,针对中国经济数据存在移动假日效应的问题,采用AICC准则对移动假日效应的影响期进行客观选取,以CPI为例阐述了最新的季节调整模型在中国经济数据方面的运用。同时,应用该模型对样本内和样本外的中国CPI数据进行预测,结果表明,样本内预测的精度很高;而样本外预测则显示中国在近期内不会发生大的通货膨胀。

时间序列中移动假日效应调整方法的比较

目的本文旨在利用模拟数据对观测值比例因子模型和天数比例因子模型的移动假日效应调整效果进行比较。方法利用SAS产生含移动假日效应的序列,分别采用两种比例因子模型进行移动假日效应调整,采用AICC和绝对预测误差进行两模型拟合效果和预测效果的比较。结果当移动假日效应强度小时,两比例因子模型的移动假日效应调整效果相当;当移动假日效应强度大时,观测值比例因子模型的拟合效果和预测效果均优于天数比例因子模型。结论序列随机波动水平高、移动假日效应强度大时,观测值比例因子模型的移动假日效应调整效果较优。

地震破裂的方向性效应相关概念综述

地震断层破裂的方向性会造成在地震动记录和地震动分布场中出现一些典型的特征,分析方向性效应的特点以及方向性效应产生的原因对于揭示近场地震动的特征有重要的意义。文中以诸多研究文献为基础,从方向性效应的研究回顾开始,分析了方向性效应的概念,并重点论述了方向性效应对地震动影响的特点、方向性效应的产生原因及其影响因素。为了阐明与方向性相关的几个概念,文中还分析了破裂传播效应,有限移动源效应和多普勒效应等概念,以及方向性对震源时间函数的影响。通过这些概念的探讨和分析,使得这些相关概念的意义更加清晰,最后给出了地震动方向性效应研究中存在的问题和建议。

广州某院门诊量的ARIMA模型预测

目的对门诊量序列进行预测，分析预测效果。方法采用时间序列ARIMA模型，对原始门诊量序列和调整1—2月门诊量后的序列进行预测，并在调整预测值基础上计算2月份的校正预测值。结果调整后序列的相对预测误差绝对值均值为3．84，明显小于原始序列的相对预测误差绝对值均值7．10。结论调整1—2月门诊量序列的预测效果明显优于原始门诊量序列的预测效果。

下击暴流移动增大效应及带协同流壁面射流模拟方法

目前对移动型下击暴流的研究主要基于冲击射流模型,但研究中通常考虑的平移速度较低且缩尺比较小。为此,通过风洞试验与数值模拟方法,研究移动冲击射流风场中平移速度对出流段平均风场的影响,得到了平移速度对下击暴流出流段最大风速增大效应的经验表达式。同时考虑到采用壁面射流方法能够得到较大尺度的下击暴流出流段风场,但并未考虑下击暴流移动增大效应。因此,改进了壁面射流模型,通过协同流模拟下击暴流雷暴云平动。采用数值模拟方法研究了协同流对壁面射流平均风剖面特征长度以及特征速度的影响,得到了协同流速度对壁面射流最大风速增大效应的经验表达式。结果表明:随着平移速度的增大,冲击射流出流段的最大平均速度的增幅可达13.3%以上,并且最大风速产生的位置更靠近壁面;在壁面射流方法中引入协同流,能够有效地模拟移动增大效应,通过建立协同增大效应与平移增大效应的对应关系,可较为准确地采用壁面射流方法得到下击暴流任意水平移动速度下的最大平均风剖面。

期待DRAM产业的春天

回首整年开高走低的 DRAM 产业回顾2002年 DRAM 产业发展动向,在整体经济环境不见明显复苏的情况下,个人计算机及手机等相关产品之出货量,都无令人振奋的讯息出现,也就是说需求方面仍处于一片混沌不明的景象。而相较于需求的不确定性,从供给方面看。

基于PMI分解的新冠肺炎疫情对制造业的冲击评估

新冠肺炎疫情对我国制造业造成了严重的冲击,就疫情的影响进行定量评估对建立科学的疫情防控机制具有重要意义。本文运用X13-A-S季节调整模型对我国制造业PMI指数进行分解,研究各成分在新冠肺炎疫情期间的波动,分析疫情的动态演化并构建本底趋势线,分别从需求与供给角度评估疫情对我国制造业的冲击。研究结果表明:X13-A-S模型对PMI指数季节调整效果较好,趋势-循环因素分为快速增长和稳定增长两个时期,季节成分呈现“三波峰,三波谷”的波动态势,不规则成分异常值波动与新冠肺炎疫情冲击相对应;疫情期间制造业PMI指数、需求侧和供给侧分别损失14.68%、21.83%、23.􀆰14%,对内需的冲击小于供给;新冠肺炎疫情对需求的冲击滞后于供给,均呈现出“先报复式反弹-后短暂回落”的复苏态势。

SUBSPACE METHOD FOR BLIND IDENTIFICATION OF CDMA TIME-VARYING CHANNELS

A new blind method is proposed for identification of CDMA Time-Varying (TV)channels in this paper. By representing the TV channel's impulse responses in the delay-Doppler spread domain, the discrete-time canonical model of CDMA-TV systems is developed and a subspace method to identify blindly the Time-Invariant (TI) coordinates is proposed. Unlike existing basis expansion methods, this new algorithm does not require .estimation of the base frequencies, neither need the assumption of linearly varying delays across symbols. The algorithm offers definite explanation of the expansion coordinates. Simulation demonstrates the effectiveness of the algorithm.

Mode Selection and Resource Allocation for Deviceto-Device Communications in 5G Cellular Networks

To meet the increasing demand of wireless broadband applications in future 5G cellular networks, Device-to-Device(D2D) communications serve as a candidate paradigm to improve spectrum efficiency. Considering the challenges after D2 D transmission is introduced for future cellular networks, this paper deals with mode selection and resource allocation issues related with D2 D communications. First, we propose a mode selection scheme which aims at guaranteeing the transmission of cellular users and also considering the potential interference. We analyze the condition under which D2 D underlay mode should be used. Second, we answer the question of "how to effectively reuse cellular resource once underlaying mode is adopted". We further present a resource allocation scheme that focuses on minimizing overall interference as well as a power control method to improve the performance of D2 D systems. Simulation results demonstrate that system parameters greatly affect the switching condition of mode selection and probability of choosing underlay mode. Furthermore, for D2 D underlaying scenario, the proposed resource allocation algorithm guarantees the transmission of cellular users with consideration of transmission requirements of D2 D users. Hence, the proposed scheme can achieve better user experience.

Study on intercarrier interference in mobile MIMO-OFDM based on the geometrical one-ring model

This paper investigates the distribution of intercarrier interference （ICI） in multiple-input multiple-output orthogonal frequency division multiplexing （MIMO-OFDM） systems based on the geometrical one-ring model. Using the spatial and temporal correlation of a geometrical one-ring model, a close-formed expression of intercarrier interference due to the Doppler effect caused by the movement of receiver is derived under the isotropic scattering conditions and non-isotropic scattering conditions. The analytical results are verified by Monte Carlo simulations. We use the generated channels to investigate MIMO-OFDM intercarrier interference under various channel parameters. It can be shown that more than 95% oflCI power comes from five neighboring subcarriers.

mobile electronic commerce in China

This paper, combined with the main feature, function, market effect, development and current situation of ME-commerce in china. analyses the problems of ME-commerce and presents the feasible countermeasure as well as the development plan.

Finite element analysis of couple effect of soil displacement and axial load on single inclined pile

The couple effect of soil displacement and axial load on the single inclined pile in cases of surcharge load and uniform soil movement is discussed in detail with the methods of full-scale field tests and finite element method. Parametric analyses including the degree of inclination and the distance between soil and pile are carried out herein. When the displacement of soil on the left side and right side of a pile is identical, deformation of a vertical pile and an inclined pile is highly close in both cases of surcharge load and uniform soil movement. When the couple effect of soil displacement and axial load occurs, settlement of an inclined pile is greater than that of a vertical pile under the same axial load, and bearing capacity of an inclined pile is smaller than that of a vertical pile. This is quite different from the case when the inclined pile is not affected by soil displacement. For inclined piles, P-Δ effect of axial load would lead to a large increase in bending moment, however, for the vertical pile, P-Δ effect of axial load can be neglected. Although the direction of inclination of piles is reverse, deformation of piles caused by uniform soil movement is totally the same. For the inclined piles discussed herein, bending moment(-8 m to-17 m under the ground) relies heavily on uniform soil movement and does not change during the process of applying axial load. When the thickness of soil is less than the pile length, the greater the thickness of soil, the larger the bending moment at lower part of the inclined pile. When the thickness of soil is larger than the pile length, bending moment at lower part of the inclined pile is zero.

People with Disabilities： Some Analyzes of the Results of the 2010 Population Census and New Challenges

In his work, was applied crossings between pairs of variables, homogeneity test and technical exhaustive AID （Automatic Interaction Detection） for formation of groups second sample each of the following deficiencies： see, listen, move and intellectual from database obtained from the 2010 Population Census data sample （respondents Complete Questionnaire） formed by 20,635,472 people interviewed all over the country with the objective of studying relationship between different variables such as disability, level of education, gender, income in minimum wages among others.

Effective Removal of Air Pollutions by the Electrical Discharge

The objectives of this study were to understand the effects of different electrical and reactor＇s parameters on the removal efficiency of air pollution and to optimize the parameters to achieve the highest removal efficiency. The surface discharge was applied to dielectric barrier discharge reactors and the voltage, current, frequency and the electrode shape were employed to the reactor as main variables. In general, it has been known that the removal efficiency is decided by the applied power, which is calculated by multiplication of the applied voltage and current. However, the removal efficiency was significantly changed by the composition ratio of the applied voltage and current even though the experimental conditions were not changed with the same applied power. It means that the removal effectiveness should be affected not by the discharge power but by the applied voltage and current separately. From the experimental and statistical analysis, the discharge current was the most important factor to control the removal efficiency regardless of different types of the reactors and the frequency is not the direct function to control the removal rate.

Coupled pile soil interaction analysis in undrained condition

The effective stress method is developed to predict the axial capacity of piles in clay. The effective stress state changes due to the resulting pore pressure change and therefore, the strength and stiffness of the soil will change. In this work, the finite element method is utilized as a tool for the analysis of pile-soil systems in undrained condition. The computer program CRISP was developed to suit the problem requirements. CRISP uses the finite element technique and allows predictions to be made of ground deformation using critical state theories. Eight-node isoparametric element was added to the program in addition to the slip element. A pile loading problem was solved in which the pile-soil system is analyzed in undrained condition. The pile is modelled as elastic-plastic material, while the soil is assumed to follow the modified Cam clay model. During undrained loading condition, the settlement values increase by 22% when slip elements are used. The surface settlement increases by about three times when the load is doubled and the surface settlement at all points increases when using slip elements due to the mode of motion which allows smooth movement of the adjacent soil with respect to the pile. The vertical displacement increases as the distance decreases from the pile and negligible values are obtained beyond 10D (where D is the pile diameter) from the center of the pile and these values are slightly increased when slip elements are used. The vertical effective stress along a section at a distance D from the pile center is approximately the same for all load increments and lower values of effective vertical stress can be obtained when slip elements are used.

差动力的理念及临床应用

差动力是Begg矫治体系的精髓,但是对差动力的认识和使用存在诸多争议.本文系统阐述了差动力的概念和精要,提出差动力是Begg矫治系统的力学体系,这一体系包含两个要素：①利用牙根表面的差异性受压来控制牙齿的移动;②通过数个交互支抗的巧妙设计实现互为转化的差异移动.

制造业结构与雾霾治理

雾霾现象引起人们高度关注,以北京雾霾为例进行的研究表明:从表现上看,累积效应、移动效应是造成北京雾霾的重要原因;从深层原因分析,制造业结构低级化(结构效应)是形成雾霾的关键。因此,治理北京雾霾,必须从优化产业结构、促进产业升级入手。

Analysis of two models for metal hot-electron power generation

Hot electron emission means that electrons move over potential barriers to come out of the metal when the metal is being heated.Obviously,voltage will generate between electrons and the metal.Based on this,the model of metal hot-electron power generation is built.Free electron model of Sommerfeld is used to describe the movement of electrons in metal.According to the different width of potential barriers,two models are built.One assumes that electrons move from one metal to another mainly by moving over the potential barrier as the barrier is wide enough.The other assumes that the potential barrier is so narrow that electrons mainly move through the potential barrier by tunnel effect.The first model is analyzed and proved strictly,including the building of model,the calculation of open-circuit voltage and the drawing of volt-ampere characteristic curve.The second model is analysed simply.This paper shows that power generation by metal hot-electron is possible based on the theory and can provide reference for researching in power generation of metal hot-electron.