NONLINEAR STABILITY OF PLANAR SHOCK PROFILES FOR THE GENERALIZED KdV-BURGERS EQUATION IN SEVERAL DIMENSIONS

This paper is concerned with the nonlinear stability of planar shock profiles to the Cauchy problem of the generalized KdV-Burgers equation in two dimensions. Our analysis is based on the energy method developed by Goodman [5] for the nonlinear stability of scalar viscous shock profiles to scalar viscous conservation laws and some new decay estimates on the planar shock profiles of the generalized KdV-Burgers equation.

Dielectric responses of graded composites having generalized gradation profiles

Under an external uniform electric field, the dielectric response of graded cylindrical composites having generalized dielectric profile inclusions is investigated. The generalized dielectric profile of graded cylindrical inclusion is expressed in the form, εi（r） = c（b ＋ r）^keβr where r is the radial variable of the cylindrical inclusions and c, b, k and β are parameters. The local potential solution of generalized dielectric profile graded composites is derived by means of the power series method and the effective dielectric response is predicted in the dilute limit. Moreover, from the result of generalized profile, the analytical solutions of local potentials and the effective responses of graded composites having three cases of dielectric profiles, i.e., the exponential profile εi（r） = ce^βr, the general power law profile εi（r） = c（b ＋ r）^k and the profile εi（r） = cr^keβr, are sorted out, respectively. In the dilute limit, our exact results are used to test the validity of differential effective dipole approximation （DEDA） for estimating the effective response of graded cylindrical composites, and it is shown that the DEDA is in excellent agreement with the exact result.

混合地理加权空间自回归模型的Profile GMM估计

为了更好地同时考虑空间自相关性和空间异质性,本文研究一类空间自回归混合地理加权回归模型.基于Profile方法和广义矩(GMM)方法,构造了模型中未知空间自回归参数,常数回归系数和系数函数的两类Profile GMM估计.数值模拟结果表明所提出的估计在有限样本中表现良好.

CNC FLEXIBLE GENERATING SPECIFIC GEAR TOOTH PROFILE BASED ON STANDARD INVOLUTE GEAR HOB

A new method named orthogonal two-way link-shift here has been proposed.Based on the method and a standard involute gear hob, a specific gear tooth profile (including anarbitrary gear tooth profile and a modified involute gear tooth profile) can be generated on aCNC(computer numerical control) bobbing machine. Computer simulation has been carried out, and theresults prove that the method is right and practicable. So, the fabrication costs can be greatlydecreased than before. The new method has momentous significance to realize gear's optimizedmodification under different work conditions.

Accuracy analysis of predicted velocity profiles of laminar duct flow with entropy generation method

The objective of this work is to estimate the accuracy of a predicted velocity profile which can be gained from experimental results, in comparison with the exact ones by the methodology of entropy generation. The analysis is concerned with the entropy generation rate in hydrodynamic, steady, laminar, and incompressible flow for Newtonian fluids in the insulated channels of arbitrary cross section. The entropy generation can be calculated from two local and overall techniques. Adaptation of the results of these techniques depends on the used velocity profile. Results express that in experimental works, whatever the values of local and overall entropy generation rates are close to each other, the results are more accuracy. In order to extent the subject, different geometries have been investigated. Also, the influence studied, and the distribution of volumetric geometries is drawn. of geometry on the entropy generation rate is local entropy generation rate for the selected geometries is drawn.

Profile Generation Methods for Reinforcing Robustness of Keystroke Authentication in Free Text Typing

We have investigated several characteristics of the keystroke authentication in Japanese free text typing, and our methods have provided high recognition accuracy for high typing skill users who can type 700 or more letters per 5 minutes. There are, however, some situations decreasing the accuracy such as long period passage after registering each user’s profile documents and existence of lower typing skill users who can type only about 500 - 600 letters per 5 minutes. In this paper, we propose new profile generation methods, profile-updating and profile-combining methods, to reinforce the robustness of keystroke authentication and show the effectiveness of them through three examinations with experimental data.

Estimating the Retrievability of Temperature Profiles from Satellite Infrared Measurements

A method is developed to assess retrievability, namely the retrieval potential for atmospheric temperature profiles, from satellite infrared measurements in clear-sky conditions. This technique is based upon generalized linear inverse theory and empirical orthogonal function analysis. Utilizing the NCEP global temperature reanalysis data in January and July from 1999 to 2003, the retrievabilities obtained with the Atmospheric Infrared Sounder （AIRS） and the High Resolution Infrared Radiation Sounder/3 （HIRS/3） sounding channel data are derived respectively for each standard pressure level on a global scale. As an incidental result of this study, the optimum truncation number in the method of generalized linear inverse is deduced too. The results show that the retrievabilities of temperature obtained with the two datasets are similar in spatial distribution and seasonal change characteristics. As for the vertical distribution, the retrievabilities are low in the upper and lower atmosphere, and high between 400 hPa and 850 hPa. For the geographical distribution, the retrievabilities are low in the low-latitude oceanic regions and in some regions in Antarctica, and relatively high in mid-high latitudes and continental regions. Compared with the HIRS/3 data, the retrievability obtained with the AIRS data can be improved by an amount between 0.15 and 0.40.

系统发育谱(Phylogenetic Profile)生成软件

系统发育谱生成软件(Phylogenetic Profile Generator,PPG)采用Microsoft Visual Basic和Perl两种语言编写,将构建系统发育谱所涉及的全部过程进行集成,用户只需提供原始的蛋白或核酸序列,软件即可生成所需的系统发育谱,并提供文本和XML两种形式的输出结果。软件具有Windows和Linux两个版本,可提供免费下载。软件下载地址:http://life.cnu.edu.cn/kexu-eyjshow.php?

An Analysis of Average Pulsar Profiles and A Study of the ρ-P relation of Pulsars

Using the method of Gaussian Fit Separation of Average Profile (GF-SAP), we re-examine the average profiles of nine pulsars at several frequencies, ranging from 408-1642 MHz. This method enables us to obtain the number of components for each pulsar, and the parameters for each component, the width, position and amplitude. The ρ-P relation for the inner cone and outer cone are studied separately, and the results are, respectively, ρ = p-0.51±0.05 and ρ= p-0.42±0.06 The results can be interpreted as a confirmation of the double-cone structure of pulsar emission beams. The altitudes of emission region, and the radius-to-frequency-map (RFM) are also examined; for the outer cone, we obtained γ(v) ∝v-0.19±0.09.

The geochemical characteristics and oil-source rock correlation of oilshow from the Majiashan profile, Chaoxian County, South of Anhui Province

In the future time the exploration of marine oil and gas will be one of the significant domains in China. In this paper the biomarker assemblage characteristics of oilshow in the Nanlinghu Formation of the Majiashan pro- file, which is located in Chaoxian County, south of Anhui Province, are described in the light of gas chromatogra- phy/mass spectrometric (GCMS) analysis on the qualitative and quantitative basis. Based on the investigation of the biomarker assemblage characteristics of possible source rocks developed in the area studied, a conclusion is drawn that the oilshow was generated from the Nanlinghu Formation source rocks (abbreviated as T1n), instead of the Qixia Formation source rocks (abbreviated as P1q). It is pointed out that the T1n is of strong potential for future oil explora- tion, and therefore much attention should be paid to it.

Genre Analysis of Online Company Profiles from Sporting Goods Brands

With the development of globalization and information technology,online company profile has been an effective commu-nication channel between companies and their target customers or clients.Online company profile,as a specific genre,has the dis-tinct features and functions in commercial activities.This study aims to do linguistic study of the constitution and the role of thesecompany profiles about sporting goods for communication on the Internet.To realize it,six company profiles have been selectedfrom the official websites of each sports company.The genre analysis of these samples is conducted from the perspective ofHasan’s Contextual Configuration(CC)and Generic Structure Potential(GSP).This thesis attempts to give the suggestions on howto compose a company profile for readers and sporting companies and the reference for the related researches in the future.

基于广义Curvelet变换和相空间特征聚类的VSP波场分离方法

垂直地震剖面(Vertical Seismic Profiling,VSP)蕴含大量的地层地质信息,是连接地震反射数据与测井资料之间的桥梁.VSP数据分辨率高,资料丰富,包括上行波、下行波、转换波等多种类型的波场,常被用于地层反射界面标定、介质衰减参数反演等.其中,如何有效地分离波场是将VSP资料应用于油气勘探的关键之一.广义Curvelet变换是一种具有多尺度、多角度的相空间变换,能够进行相空间域波场特性的提取.本文聚焦于VSP波场的上下行波分离问题,提出一种基于广义Curvelet变换和相空间特征聚类方法.首先,采用广义Curvelet变换对VSP波场进行特征提取,构造融入相空间角度信息的特征数据集;然后,利用K-means聚类算法在相空间对波场特征进行分类;最后,对分类结果进行反变换,完成VSP上下行波波场的自适应分离.为了验证方法的有效性,本文将所提出的方法用于合成数据和实际VSP数据的波场分离,并与常用的基于F-K变换的波场分离方法进行对比.处理结果表明,本文方法角度分辨率高、抗噪能力强,波场分离结果的保真保幅性好,这为后续的成像与地层的特征分析提供了重要基础资料.

低视力患者一般自我效能感LPA及其与生存质量的关系研究

目的探究低视力患者一般自我效能感潜在类别,探讨不同潜在类别与生存质量的关系及生存质量的影响因素。方法采用横断面临床研究设计,纳入2021年5月—2022年4月在首都医科大学附属北京同仁医院就诊的低视力患者234例(289只眼),采用一般自我效能感量表(GSES)和中文版低视力生存质量量表(CLVQOL)进行调查,使用Mplus8.0和SPSS 26.0统计学软件分析一般自我效能感潜在类别及与生存质量的关系,采用多重线性回归法分析生存质量的影响因素。结果(1)剖面分析结果:当一般自我效能感潜在剖面数为3时,艾凯克信息准则(AIC)、贝叶斯信息准则(BIC)、调整贝叶斯信息准则(aBIC)值最大,entropy更接近1,剖面3为最佳模型。(2)类别特点及命名:本研究中的低视力患者分为3个潜在类别,类别1(23.9%)一般自我效能感水平最高,命名为高效能感型;类别2(54.7%)位于整体得分的中间水平,命名为中效能感型;类别3(21.4%)一般自我效能感得分最低,命名为低效能感型。(3)类别的基本特征:一般自我效能感不同潜在类别的低视力患者基本特征比较显示,年龄(χ^(2)=16.727,P=0.033)、文化程度(χ^(2)=11.389,P=0.023)、医疗费用来源(χ^(2)=27.914,P=0.000)、户籍类型(χ^(2)=16.503,P=0.002)、视力损伤时长(χ^(2)=36.607,P=0.000)、职业类型(χ^(2)=11.207,P=0.004)、视力(χ^(2)=19.433,P=0.001)和既往眼部手术史(χ^(2)=8.293,P=0.016)在3个不同潜在类别间的差异均有统计学意义,其他社会人口学特征差异均无统计学意义(P>0.05)。(4)类别与生存质量的关系:不同自我效能感潜在类别的低视力患者生存质量总分比较,差异有统计学意义(F=8.187,P=0.000),生存质量各维度比较显示,远视力、移动、光感(F=6.057,P=0.003)、阅读和精细工作(F=9.648,P=0.000)、调节能力(F=5.214,P=0.007)、日常生活能力(F=8.164,P=0.000),差异均有统计学意义。(5)生存质量影响因素的多因素分析:视力(t=-6.582,P=0.000)、一般自我效能感不同潜在类别(t=-2.092,P=0.039)为生存质量的独立影响因素,差异均有统计学意义。结论低视力患者的一般自我效能感存在异质性,应重点关注低效能感型和视力受损严重的低视力患者,探索一般自我效能感干预策略,提高其生存质量水平。

基于生成式预训练语言模型的学者画像构建研究

大数据时代,互联网中以多源异构、非结构化形式存在的学者信息在实体抽取时伴有属性混淆、长实体等问题,严重影响学者画像构建的精准度。与此同时,学者属性实体抽取模型作为学者画像构建过程中的关键模型,在实际应用方面还存在较高的技术门槛,这对学者画像的应用推广造成一定阻碍。为此,在开放资源的基础上,通过引导句建模、自回归生成方式、训练语料微调等构建一种基于生成式预训练语言模型的属性实体抽取框架,并从模型整体效果、实体类别抽取效果、主要影响因素实例分析、样例微调影响分析4个方面对该方法进行验证分析。与对比模型相比,所提出的方法在12类学者属性实体上均达到最优效果,其综合F1值为99.34%,不仅能够较好地识别区分相互混淆的属性实体,对“研究方向”这一典型长属性实体的抽取准确率还提升了6.11%,为学者画像的工程化应用提供了更快捷、有效的方法支撑。

面向天河新一代超算系统通用处理器的性能分析工具集

天河新一代超算系统是继天河2号后天河系列的新一代超算系统.该系统拟采用通用处理器配合加速器的混合异构架构,其中通用处理器采用ARM架构.目前,面向ARM架构处理器的性能分析工具仍不够完善,而面向新一代超算的性能分析工具更是较为匮乏,实用性和效率还难以满足编程人员的需求.本文针对天河新一代超算系统的通用处理器,设计开发了一套性能分析工具集,包含缓存冲突检测、伪共享检测和内存缺陷检测三个子工具.工具集可以在天河新一代超算系统的普通用户权限下分析系统单节点内以及数据并行性较高的多节点程序的性能问题,并可以解决程序的内存问题.本文使用min-write、缓存行对齐填充、线程访问隔离等多种性能优化策略来提高工具性能,采用以上策略的工具的运行时间可至多减少至原先的1/20,同时使用新颖的红区检测法和红区隐藏与恢复机制来降低工具报告的假错误率.本文还开发了配套的可视化界面,使用户可以对程序的性能分析数据进行可视化的分析和处理,提高了工具的实用性和易用性.工具对程序执行带来的额外时间开销是40~100倍,额外内存开销是100~200倍,正确性和实用性得以保证,可以提高天河新一代超算系统的编程效率和程序性能.

2岁龄滩湖杂G_(0)代与滩羊产肉性能、肉品质及风味物质的比较研究

旨在比较研究2岁龄滩湖杂G_(0)代与滩羊产肉性能、肉品质及风味物质方面的差异。选取2岁龄健康、体重相近的滩湖杂G_(0)代公羊和同期滩羊公羊各3只,屠宰后测定产肉性能、肉品质,电子鼻测定肉质气味轮廓。结果:2岁龄滩湖杂G_(0)代与同期滩羊各项屠宰性状差异均不显著(P>0.05),但G_(0)代胴体重、屠宰率、净肉率、GR值及背膘厚等指标高于滩羊,尾重较滩羊降低4.88%,头重显著低于滩羊(P<0.05),皮张面积大于滩羊(P<0.05)。与滩羊肉质相比,滩湖杂G_(0)代肉中氨基酸与脂肪酸含量差异不显著(P>0.05),但剪切力降低7.95%,失水率降低10.55%。对肉质起挥发性作用的物质是氮氧化合物、烷烃及芳香成分,利用电子鼻不能完全区分滩湖杂G_(0)代与滩羊肉质。综上,2岁龄滩湖杂G_(0)代的屠宰性能有优于同期滩羊的趋势,肉质食用品质有所提升,肉品风味无显著差异。

组织支持感对新生代幼儿教师工作绩效的影响——基于潜在剖面分析

基于个体中心对526位新生代幼儿教师的组织支持感进行潜在剖面分析。结果显示:新生代幼儿教师组织支持感可分为不均衡支持型、中等支持型和高支持型3种;3种类型的新生代幼儿教师在工作绩效的总分,以及任务绩效、人际促进、工作奉献的得分上差异显著。为进一步提升新生代幼儿教师的工作绩效,建议合理提高他们的薪资待遇,增强教师情感支持;营造支持性的组织氛围,提高教师工作自主性;实施差异化策略,全面提升新生代幼儿教师的组织支持感。

沙库巴曲缬沙坦钠片体外溶出方法的建立及评价

目的 建立沙库巴曲缬沙坦钠片体外溶出测定方法,并对仿制制剂与参比制剂进行溶出曲线相似性的评价。方法 溶出度试验采用桨法,转速50 r·min^(-1);以0.1 mol·L^(-1)盐酸溶液、pH4.5醋酸盐缓冲液、pH6.8磷酸盐缓冲液、水各900mL为溶出介质;采用高效液相色谱法测定溶出量。结果 建立的体外溶出测定方法专属性、线性、准确度、重复性及精密度良好,供试品溶液室温放置48 h稳定;所有制剂样品在pH4.5醋酸盐缓冲液、pH6.8磷酸盐缓冲液及水中均能完全溶出,30min溶出量均>85%;3批仿制制剂与参比制剂溶出曲线的相似因子(f2)在0.1mol·L^(-1)盐酸溶液、pH4.5醋酸盐缓冲液、pH6.8磷酸盐缓冲液及水中分别为66~92、65~72、58~63及72~79。结论 体外不同生理pH溶出介质中,仿制制剂与参比制剂的溶出曲线相似因子(f2)均大于50,溶出曲线均相似,体外溶出行为一致,可为后续体内生物等效评价提供参考。

醋酸阿比特龙仿制制剂与参比制剂溶出曲线相似度研究

目的建立醋酸阿比特龙片溶出度的测定方法,评价醋酸阿比特龙仿制制剂与参比制剂溶出曲线的相似性。方法采用桨法(转速50 r/min),测定醋酸阿比特龙片仿制制剂(B厂家、C厂家、D厂家,共9批)和参比制剂(A厂家,1批)样品在0.25%十二烷基硫酸钠(SDS)的水、0.25%SDS的pH 2.0盐酸溶液、0.25%SDS的pH 4.5磷酸盐缓冲液、0.25%SDS的pH 6.8磷酸盐缓冲液4种溶出介质中的溶出度。采用高效液相色谱法测定9批仿制制剂样品的溶出量,色谱柱为Agilent Eclipse Plus C_(18)柱(100 mm×4.6 mm,3.5μm),流动相为乙腈-水(80∶20,V/V),流速为1.0 mL/min,柱温为50℃,检测波长为254 nm,进样量为10μL;计算累积溶出量,绘制溶出曲线,并采用相似因子(f_(2))法评价溶出曲线的相似性。结果与参比制剂比较,9批仿制制剂样品的体外溶出曲线均具有相似性,f_(2)均大于50。结论所建立的方法适用于醋酸阿比特龙片的溶出度测定,可为其质量标准提高和质量一致性评价提供参考。

高效液相色谱法测定乙醇对格列吡嗪控释片体外释放行为的影响

目的采用国家药品监督管理局发布的指导原则对不同企业格列吡嗪控释片仿制制剂及其参比制剂的乙醇剂量倾泻情况进行对比研究。方法采用高效液相色谱法测定格列吡嗪控释片仿制制剂及其参比制剂在不同乙醇浓度中的体外释放行为,绘制溶出曲线,采用溶出相对变化率来评价乙醇对药物释放的增速作用,并通过计算相似因子(f2)评价不同制剂体外释放的相似性。结果随着乙醇浓度的升高,在5%、20%乙醇溶液中仿制制剂与参比制剂的体外释放量几乎无变化,在40%乙醇中释放量均出现了一定的升高,但其相似因子f2均未低于50,与无乙醇的盐酸介质释放特性相似,同时仿制制剂体外释放行为与参比制剂相似。结论仿制制剂符合一致性评价质量标准。0%~40%浓度的乙醇对格列吡嗪控释片的体外释放行为无显著性影响,推测制剂中的亲水性辅料及独特的双层渗透泵结构是消除乙醇剂量倾泻影响的关键因素,对格列吡嗪与酒精饮料同服的合理用药与安全风险预测具有一定的参考价值。