出土算术文献复原的新方法:穷举法、特性分析法

数字残缺是出土算术类文献整理中的常见问题。《算数书》“大广”算题有两种在特定情况下简单有效的解决此问题的方法,即穷举法、特性分析法。穷举法,即将取值范围内所有的可选项逐一验证,直到验证完毕。其要求是:可选项必须是有限的。它在分母完整、分子缺失的情况下,简单有效,通常可以极大地缩小范围,甚至是直接得出正确答案。特性分析法是根据算题的特性,灵活地采取相应的解法。

基于经验模态分解的管道预警系统信号多尺度混沌特性分析方法

提出了一种用于油气管道安全预警系统的检测信号多尺度混沌特性分析的新方法。该预警系统基于Mach-Zehnder光纤干涉仪原理,沿管道同沟敷设一条光缆,利用其中的三条单膜光纤构成分布式微振动测试传感器,实时检测管道沿途发生的泄漏及其他异常事件。多尺度混沌特性分析方法是利用经验模态分解(EMD)方法对典型的异常事件振动信号进行分解,再分别对分解得到的固有模态(IMF)分量进行混沌特性分析,计算出不同尺度下的关联维数。该方法可更清晰地描述检测信号在不同尺度下的混沌特性。利用现场试验得到的信号对该方法进行验证的结果表明,利用多尺度混沌特性分析方法更容易有效地区分几种典型异常事件。

变压器比率差动保护若干问题的分析

针对变压器比率差动保护与整定过程中的问题作了分析。指出在电流差动保护动作特性分析法中,动作区域判定有误,并提出了正确的分析与判断方法。通过分析比较变压器比率差动常用判据,对制动量阈值设定与内部故障时允许流出的电流数值,提出了改进意见。

导叶关闭规律对水电站流道压力分布特性影响

水电站过渡过程中,不同导叶关闭规律对流道压力值及分布特性有较大影响,特别对引水道短、断面尺寸大的坝后式水电站,可能造成同一断面的压力不均问题,危及水电站的安全。为探求不同导叶关闭规律对坝后式水电站流道压力空间分布特性的影响,以典型坝后式水电站三峡右岸水电站为研究对象,通过水电站过渡过程全流道压力特性三维数值模拟及自定义的压力特性差异分析法,对比不同导叶关闭规律下的水电站流道典型断面压力空间分布差异。结果表明:采用三段导叶关闭规律更能限制转轮最大转速,而采用两段导叶关闭规律使得流道同一断面的压力分布更为均匀,从而对流道有利,能保证水电站的安全稳定运行。

电磁阀试验台的流体脉动及其消减措施的研究

对电磁阀试验台流体系统产生脉动的原因作了分析与探讨,并应用频率特性分析法对主测试管路的频率特性进行了计算和仿真;在此研究基础上选取最佳的结构和元件参数以及采取相应的消振和滤波措施,可有效地减少和消除流体系统可能出现的压力脉动并避开谐振现象发生。该研究对相关流体控制和测试系统研发中如何避免测试管路谐振现象的发生及消减流体压力脉动和冲击具有一定的工程应用价值。

创造性思维与创造性设计

思维科学即不是自然科学,也非同于社会科学,它应该成为一门独立的科学。当今世界进入90年代,电子技术时代,信息时代,对于创造出这一发达历史时代的人的思维,应该做为一门科学来研究。人们为什么能创造如此先进的电子技术、电脑,开辟如此新的世界:登上月球和其它星球……现代科学。

凝胶／聚乙烯醇混合生物降解膜的热机械性能

用差示扫描量热法（DSC）和动力-机械特性分析法（DMA）讨论了聚乙烯醇（PVA）浓度对凝胶／PVA混合薄膜热、粘弹性能的影响。先扫描混合薄膜，后在116℃-134℃的温度下熔解结晶部分，在所得DSC曲线上可观察到43℃和49℃间有一个玻璃化点，但是用DMA分析结果表明，含10％PVA的薄膜在tanδ光谱上仅有一个峰，随着PVA浓度的增加，动力tanδ光谱上会出现两个峰，表明有两个玻璃化温度Tg。并成功地应用Gordon和Taylor模块将Tg做成混合膜组成的关联函数，测出k=7．47，在DMA频率实验中，该光谱表明储能模量随温度的升高而降低，用TTS（Tr=100℃）原理可得到PVA／凝胶薄膜叠加曲线，用WLF模块测量常数C1和C2,这些常数随混合物中PVA浓度的增加而增大：C1=49—66，C2=463—460，它们可用来计算在玻璃化温度Tg下混合膜的自由体积份数和高于Tg时的热膨胀系数。

Oblique Wave Motion over Multiple Submerged Porous Bars near a Vertical Wall

This study examines oblique wave motion over multiple submerged porous bars in front of a vertical wall. Based on linear potential theory, an analytical solution for the present problem is developed using matched eigenfunction expansions. A complex dispersion relation is adopted to describe the wave elevation and energy dissipation over submerged porous bars. In the analytical solution, no limitations on the bar number, bar size, and spacing between adjacent bars are set. The convergence of the analytical solution is satisfactory, and the correctness of the analytical solution is confirmed by an independently developed multi-domain BEM （boundary element method） solution. Numerical examples are presented to examine the reflection and transmission coefficients of porous bars, CR and Cv, respectively, for engineering applications. The calculation results show that when the sum of widths for all the porous bars is fixed, increasing the bar number can significantly improve the sheltering function of the bars. Increasing the bar height can cause more wave energy dissipation and lower CR and Cr. The spacing between adjacent bars and the spacing between the last bar and the vertical wall are the key parameters affecting CR and Ct. The proposed analytical method may be used to analyze the hydrodynamic performance of submerged porous bars in preliminary engineering designs.

Analysis of the nonlinear dynamic characteristics of two-phase flow based on an improved matrix pencil method

Gas–liquid two-phase flow is complex and has uncertainty in phase interfaces, which make the two-phase flow look very complicated. Even though the flow behavior(e.g. coalescence, crushing and separation) of single bubble or bubble groups in the liquid phase looks random, combining some established characteristics and methodologies can find regularities among the randomness. In order to excavate the nonlinear dynamic characteristics of gas–liquid two-phase flow, the authors developed an improved matrix pencil(IMP) method to analyze the pressure difference signals of the two-phase flow. This paper elucidates the influence of signal length on MP calculation results and the anti-noise-interference ability of the MP method. An IMP algorithm was applied to the fluctuation signals of gas–liquid two-phase flow to extract the mode frequency and damping ratio, which were combined with the component energy index(CEI) entropy to identify the different flow patterns. It is also found that frequency, damping ratio, CEI entropy and stability diagram together not only identify flow patterns, but also provide a new way to examine and understand the evolution mechanism of physical dynamics embedded in flow patterns. Combining these characteristics and methods, the evolution of the nonlinear dynamic physical behavior of gas bubbles is revealed.

Study on slope reliability method Response Surface Method based on Morgenstern-Price Method

The combination of Morgenstern-Price Method （MPM） with Response Surface Method （RSM） improves the eonventional RSM by replacing Finite-Element Method （FEM） with MPM, which is a type of reliability analysis method-RSM based on MPM, and makes the computing process simpler. The stability of the slope was re-evaluated by use of Monte Carlo method （MCM） and the result contrasted with the fore is the conclusion. The reliability analysis of the artificial slope in Donggang Power Station was carried on, and obtained the reliable charaeteristics, which provided basis for the project.

Time-Ordered Collaborative Filtering for News Recommendation

Faced with hundreds of thousands of news articles in the news websites,it is difficult for users to find the news articles they are interested in.Therefore,various news recommender systems were built.In the news recommendation,these news articles read by a user is typically in the form of a time sequence.However,traditional news recommendation algorithms rarely consider the time sequence characteristic of user browsing behaviors.Therefore,the performance of traditional news recommendation algorithms is not good enough in predicting the next news article which a user will read.To solve this problem,this paper proposes a time-ordered collaborative filtering recommendation algorithm(TOCF),which takes the time sequence characteristic of user behaviors into account.Besides,a new method to compute the similarity among different users,named time-dependent similarity,is proposed.To demonstrate the efficiency of our solution,extensive experiments are conducted along with detailed performance analysis.

Numerical Simulation of Surface Acoustic Wave and Detection of Surface Crack in Steel

The surface acoustic wave （SAW） propagating in a sample of steel is simulated by using finite element method （FEM）. The waves are excited by a load function with propagation properties such as phase velocity disper- sion and wide bandwidth. A two-dimensional model consisting of surface defects loaded with a wideband 50--200 M Hz and short time 0.1 gs displacement function is investigated in the time and frequency domains. By transient dy- namic analysis, Fourier transform and dispersion calculation, snapshots of propagating wave and responses from sens- ing points are presented. It is indicated that this supervision approach is sensitive to the surface cracks and reflections.

Research on the road landscape evaluation system with the emphasis on the landscape ecology

As the idea of the sustainable development wins support among the people, people have already realized that not only should the road have the transportation function, but we also should consider the rationality of the road construction fi＇om the multiple angles of the landscape ecology, and the visual art and so on. From the point of view of the landscape ecology, combined with the characteristics of the landscape ecology and the overall targets and requirements of the evaluation, this article constructs a three-tier system of indicators, uses the fuzzy comprehensive evaluation model based on the analytic hierarchy process to evaluate the road landscape, and makes an empirical analysis with the evaluation of the road landscape fi＇om the Luoshi Road to the East Lake Road in the Second Loop of Wuhan City as an example.

Manufacture of Flax Reinforced PP Laminates and Research on the Tensile Properties

Flax fiber was used to reinforce Polypropylene （PP） owing to its lower impact on environment and suitable mechanical behaviors. To overcome the difficulty of penetrating fibers due to the high viscosity of thermo-plastic resin, PP filaments wrapping around the linen yam produced commingled yams, which were woven into fabrics as preforms to make laminates by optimum hot-pressing technology. The effects of fiber volume fraction, fabric density and structure on tensile properties of composites were researched through analyzing the tensile test results and the scanning electronic microscope （SEM） micrographs of fracture surface. Conclusions are drawn that the properties of laminates with fiber volume fraction of 0.50 are better than those with the other two fractions. For plain structure, the tensile properties in warp direction decrease according to the increase of weft density while in weft direction increase. For different fabric structures, properties of laminates with structures of plain 3, twill 2/2 and twill 3/1 increase gradually. And properties in weft direction are prior to those in warp direction for each laminate.

Elastic-plastic analysis for pile-anchor supporting system of deep foundation pit

By using numerical analysis methods to simulate the deep excavation,a lot of analyses are established on the basis of two-dimensional plane strain,ignoring the fact that foundation pit possesses three dimensions. For soil constitutive relation,people always take linear and nonlinear model,without considering the plastic behavior of soil. Using plastic-elastic hardening model to simulate constitutive relation of soil characteristics,the authors carried out mechanical analysis for pit excavation and support. The results show that the analysis for the stress state of pile anchor system is an effective way which provides theoretical basis for calculation of soil displacement.

Dynamic characteristic analysis of whole machine tools based on Kriging model

In order to study the variation of machine tools’dynamic characteristics in the manufacturing space,a Kriging approximate model is proposed.Finite element method(FEM)is employed on the platform of ANSYS to establish finite element(FE)model with the dynamic characteristic of combined interface for a milling machine,which is newly designed for producing aero engine blades by a certain enterprise group in China.The stiffness and damping of combined interfaces are adjusted by using adaptive simulated annealing algorithm with the optimizing software of iSIGHT in the process of FE model update according to experimental modal analysis(EMA)results.The Kriging approximate model is established according to the finite element analysis results utilizing orthogonal design samples by taking into account of the range of configuration parameters.On the basis of the Kriging approximate model,the response surfaces between key response parameter and configuration parameters are obtained.The results indicate that configuration parameters have great effects on dynamic characteristics of machine tools,and the Kriging approximate model is an effective and rapid method for estimating dynamic characteristics of machine tools in the manufacturing space.

Visualization of Understanding of Media Characteristics Using Analytic Hierarchy Process

The purpose of this study is to design a tool, adapted to students＇ individual contexts and to enable students to reflect on their understanding of media characteristics. AHP （analytic hierarchy process） is a structured technique for organizing and analyzing complex decisions. Using AHP, students have to define appropriate criteria and priorities for using media. It is expected that students＂ understanding of the characteristics of different types of media will emerge through reflection. Seventy two university students took part in this research. They were asked to prioritize their ways.of obtaining information about current affairs using sets of media such as TV, books, newspapers and web pages, Twitter and Facebook. AHP enables us to visualize a ＂real＂ understanding of media characteristics and students can reflect on that basis. As far as ＂information sources and media＂ is concerned, a few students indicated that it was the information source itself that was important rather than the type of media. Our tool fulfils the role of encouraging this type of reflection.

Optimal energy-efficient power control for cognitive radio based on static and dynamic features of primary users

In this paper, the energy-efficient power control problem in cognitive radio （CR） networks is studied not only to provide energy-efficient transmission, but also to guarantee the normal operation of primary users （PUs）. Moreover, the static energy-efficient power control （SEPC） algorithm is proposed in static scenario to maximize the capacity of secondary users （SUs） and to reduce the power consumption according to the interference from PU to SU. Furthermore, based on the analysis of PU＇s dynamic feature with Markov chain and SEPC algorithm,the dynamic energy-efficient power control （DEPC） algorithm is proposed taking into account the probability of detection and false alarm caused by sensing errors. Extensive simulation results show that the performance of the proposed algorithms is significantly improved compared with the existing algorithm.

Recent advances of TCM treatment of childhood atopic dermatitis

Atopic dermatitis （AD） is a common and frequently encountered disease, which frequently appears in children. According to statistics, the percentage of AD patients between ages of 6 to 20 in dermatology clinics is 30%^1, and the incidence in school-age children is 2%-3%^2. AD has no corresponding nomenclature in traditional Chinese medicine （TCM）. According to the initial time of attack in early childhood, it cma be classified as NaiXuan and TaiXuan; according to the location of the disease （elbow fossa and popliteal fossa）, it can be classified as SiWanFeng; according to the specific cases of different characteristics of lesions, it can be classified as ShiChuang, JinYinchuang, XueFengChuang. In TCM, the etiology of AD is complicated. It is generally considered that the pathogenesis of AD is spleen deficiency and damp-heat^3. When children suffer from pathogenic wind, pathogenic dampness, pathogenic heat, or insufficient natural endowment, damp-heat is produced and it injures patients＇ skin. Also latent damp-heat can deplete the blood and succus in the body, dry the skin and lead to AD. In short, AD can be divided into 3 syndrome types in TCM： syndrome of spleen deficiency, syndrome of damp-heat, syndrome of blood deficiency. At present, the clinical study of AD treated by TCM is increasing, but the study of children＇s treatment is still rare. This article aims to make a summary of clinical studies of children＇s AD treated with TCM in recent years.

Analysis of the Adjacent Terrain Effect on the Properties of Ground Motion

The explicit finite element analysis method combined with the artificial transmitting boundary theory is performed to evaluate the adjacent terrain effects on ground motion,and the influence of the distance between adjacent terrains on the topographical amplification effects on ground motion is studied. The results show that:( 1) Compared to the case of a single hill,the presence of adjacent hills has little effect on the shape of the spectral ratio curve,but has a significant effect on the value of spectral ratio,which is dependent on the locations of observation points.( 2) The presence of adjacent hills has a greater effect on high-frequency ground motion,and with the increase of the distance between adjacent hills,such an effect weakens gradually,and the effect of the composite topography combined with multiple hills on ground motion gradually approaches that of a single hill.