中西裤装发展与比较

裤子是我们现代人穿用的一种服装类型,不管是西方还是东方,裤装的发展与演变都有着悠久的历史,又因各自文化的不同,呈现出较大的差别。文章概述中西裤装发展的不同历程与特点,由此分析中西裤装的特色及文化差异。     

VB与Matlab混合编程在梯度胶片制作中的应用

在梯度胶片制作系统的设计中,为了完成制胶系统上位机数据计算、图形显示、系统管理软件的设计,采用Matlab函数根据采样数据合出步进电机进给控制曲线,结合VB将曲线和数据显示在人机交互界面上,将所计算的参数提供给下位控制系统,系统通过曲线插补计算对步进电机进行控制来完成胶片制作.经实践检验,这种方法所设计的监控程序功能完善、界面良好、操作方便.     

基于EPS格式条形码的图形识别

由于EPS格式为矢量类文件,无分辨率可言,很难利用数字图像处理技术来识别。针对EPS格式条形码识别过程中存在诸如受黑墨扩展因素造成了条码的条和空的比例不符,无法准确识别出正确的条码等问题,提出了一种基于二进制法解析EPS格式条形码,并对其进行识别,判断条码的准确度,这样可以提前检测出EPS格式条码的错误。对不同放大系数的条形码进行分析,从而避免生成胶片和印刷时的误差和浪费。实验结果证明效果显著。     

校报个性化与舆论导向关系的正确处理

校报是高校的“机关报”,起着宣传学校办学思想,弘扬主弦律的重要作用。随着数字化媒体的高速发展和有力冲击,校报怎样办出特色,让大家喜闻乐见,值得我们深思。本文就如何更好地发挥校报的舆论导向功能,如何使校报突出个性化作探讨。     

涉税案件移送司法处理中存在的问题及建议

我国加入世贸组织之后,国民经济发展面临着新的机遇和挑战,同时,与经济发展密切相连的金融财税领域也迎来了新的挑战.文中总结了涉税案件移送司法机关处理中存在的问题,并就今后的研究重点和发展方向提出了一些建议,为税务行政执法与司法处理的衔接奠定坚实基础.     

几种5,5-二甲基海因高分子键合剂的合成及其性能研究

为解决推进剂的脱湿问题合成出了3-烯丙基-5,5-二甲基海因(ADMH),并将其与甲基丙烯酸β-羟乙酯和丙烯腈两种单体进行反应物配比不同的共聚,得到3个共聚物键合剂.将其应用到NEPE推进剂的某个配方中,进行了力学性能测试.试验结果表明,ADMH可有效提高推进剂在常温、高温和低温时的最大抗拉强度、最大延伸率和断裂延伸率;3个聚合物键合剂可大幅度提高最大抗拉强度,但对延伸率的提高还有待研究.     

Self-adaptive PID controller of microwave drying rotary device tuning on-line by genetic algorithms

The control design, based on self-adaptive PID with genetic algorithms(GA) tuning on-line was investigated, for the temperature control of industrial microwave drying rotary device with the multi-layer(IMDRDWM) and with multivariable nonlinear interaction of microwave and materials. The conventional PID control strategy incorporated with optimization GA was put forward to maintain the optimum drying temperature in order to keep the moisture content below 1%, whose adaptation ability included the cost function of optimization GA according to the output change. Simulations on five different industrial process models and practical temperature process control system for selenium-enriched slag drying intensively by using IMDRDWM were carried out systematically, indicating the reliability and effectiveness of control design. The parameters of proposed control design are all on-line implemented without iterative predictive calculations, and the closed-loop system stability is guaranteed, which makes the developed scheme simpler in its synthesis and application, providing the practical guidelines for the control implementation and the parameter design.     

Reliability analysis of retaining walls with multiple failure modes

In order to reduce the errors of the reliability of the retaining wall structure in the establishment of function, in the estimation of parameter and algorithm, firstly, two new reliability and stability models of anti-slipping and anti-overturning based on the upper-bound theory of limit analysis were established, and two kinds of failure modes were regarded as a series of systems with multiple correlated failure modes. Then, statistical characteristics of parameters of the retaining wall structure were inferred by maximal entropy principle. At last, the structural reliabilities of single failure mode and multiple failure modes were calculated by Monte Carlo method in MATLAB and the results were compared and analyzed on the sensitivity. It indicates that this method, with a high precision, is not only easy to program and quick in calculation, but also without the limit of nonlinear functions and non-normal random variables. And the results calculated by this method which applies both the limit analysis theory, maximal entropy principle and Monte Carlo method into analyzing the reliability of the retaining wall structures is more scientific, accurate and reliable, in comparison with those calculated by traditional method.     

基于期望造价的黄土路堑高边坡优化设计模型

考虑黄土高边坡的工后失效费用问题,使设计方法更加合理完善.基于期望造价,应用数学和力学原理,并结合黄土特征,假定最危险滑动面为抛物线型,对高边坡进行可靠度分析,建立了黄土路堑高边坡的优化设计模型.以铜黄公路高边坡为例对模型进行验证,计算结果表明,总坡比1:1.26时,总期望造价最小,模型与实际情况相符.该模型前瞻性强、意义明确,对设计人员和决策者有重要参考价值.     

蓝牙与802.11b的干扰与共存分析

无线局域网和蓝牙都工作在2.4GHz的ISM频段,它们如果在一起工作,在无干扰防范措施时数据碰撞明显,传输效率低下.为了提高传输效率,该文分析了碰撞的原因、理论模型与概率,结合无线局域网和蓝牙间的距离、吞吐量、丢包率影响的实际测试结果,从发射功率调整、距离控制和帧长控制方面提出了小范围、低密度应用环境下的无线局域网和蓝牙共存技术和方法.     

Strength of copolymer grouting material based on orthogonal experiment

Using the orthogonal experimental design method involving three factors and three levels, the flexural strength and the compressive strength of copolymer grouting material were studied with different compositions of water-cement ratio (mass fraction of water to cement), epoxy resin content, and waterborne epoxy curing agent content. By orthogonal range and variance analysis, the orders of three factors to influence the strength, the significance levels of different factors, and the optimized compound ratio scheme of copolymer grouting material mixture at different curing ages were determined. An empirical relationship among the strength of copolymer grouting material, the water-cement ratio, the epoxy resin content, and the waterborne epoxy curing agent content was established by multivariate regression analysis. The results indicate that water-cement ratio is the most principal and significant influencing factor on the strength. Epoxy resin content and waterborne epoxy curing agent content also have a significant influence on the strength. But epoxy resin content has a greater influence on the 7-day and 28-day flexural strength, and waterborne epoxy curing agent content has a greater influence on the 3-day flexural strength and the compressive strength. The copolymer grouting material with water-cement ratio of 0.4, epoxy resin content of 8% (mass fraction) and waterborne epoxy curing agent content of 2% (mass fraction) is the best one for repairing of cement concrete pavement. The flexural strength and the compressive strength have good correlation, and the ratio of compressive strength to flexural strength is between 1.0 and 3.3. Foundation item: Projects(40728003, 40772180, 40802064) supported by the National Natural Science Foundation of China; Project (07JJ4012) supported by the Hunan Provincial Natural Science Foundation of China; Project(20080430680) supported by China Postdoctoral Science Foundation; Project(B308) supported by Shanghai Leading Academic Discipline Project     

Strain rate effects on sand and its quantitative analysis

Strain rate effects on the stress—strain behavior of sand were investigated by performing special plane strain and triaxial compression tests on saturated and air-dried sand specimens. In these tests, the loading strain rate was changed many times by a factor of up to 1 000 during otherwise monotonous loading at a constant axial strain rate. Test results show that the stress jump upon a stepwise change in the strain rate decays with an increase in the irreversible strain when monotonous loading continues at the changed strain rate and the amount of stress jump is essentially proportional to the instantaneous stress. Based on the amount of these stress jumps, a parameter β called the rate-sensitivity coefficient is introduced to represent the quantity of the observed viscous properties of sand, which equals 0.021 3 and 0.024 2 respectively for Hostun and Toyoura sands. Further analyses on the results indicate that the effect of the presence of pore water is deemed to be negligible with sand and the β value is rather independent of loading method, wet condition and confining pressure. Foundation item: Project(50679056) supported by the National Natural Science Foundation of China; Project(06-0378) supported by Program for New Century Excellent Talents in University; Project(05SG25) supported by the “Dawn” Program of Shanghai Education Commission, China; Project(B308) supported by the Shanghai Leading Academic Discipline, China     

Strength and elastic properties of sandstone under different testing conditions

A laboratory experimental program performed on Wuhan sandstones was presented under monotonic loading, partial cyclic loading during loading path and sine wave cyclic loading with different strain rates to compare uniaxial compression strength and elastic properties （elastic modulus and Poisson ratio） under different conditions and influence of pore fluid on them. When the loading strain rates are 10^-5, 10^-4 and 10^-3/s, uniaxial compression strengths of dry sandstones are 82.3, 126.6 and 141.6 MPa, respectively, and that of water saturated sandstones are 70.5, 108.3 and 124.1 MPa, respectively. The above results show that the uniaxial compression strength increases with the increase of strain rate, however, variation of softening coefficient is insignificant. Under monotonic loading condition, tangent modulus increases with an increment of stress （strain） to a maximum value at a certain stress level, beyond which it starts to decline. Under the partial cyclic loading during loading path condition, unloading or reloading modulus is larger than loading modulus, and unloading and reloading moduli are almost constants with respect to stress level, especially unloading modulus. Under the sine wave cyclic loading condition, tangent modulus and Poisson ratio display asymmetric ‘X＇ shape with various strain, and the average unloading modulus is larger than the average loading modulus.     

Directly searching method for slip plane and its influential factors based on critical state of slope

In order to determine the slip plane of slope directly by the calculation results of strength reduction method, and analyze the influential factors of slope stability, a numerical model was established in plane strain mode by FLAC3D for homogeneous soil slope, whose parameters were reduced until the slope reached the critical state. Then FISH program was used to get the location data of slip plane from displacement contour lines. Furthermore, the method to determine multiple slip planes was also proposed by setting different heights of elastic areas. The influential factors for the stability were analyzed, including cohesion, internal friction angle, and tensile strength. The calculation results show that with the increase of cohesion, failure mode of slope changes from shallow slipping to the deep slipping, while inclination of slip plane becomes slower and slipping volume becomes larger; with the increase of friction angle, failure mode of slope changes from deep slipping to shallow slipping, while slip plane becomes steeper and upper border of slip plane comes closer to the vertex of slope; the safety factor increases little and slip plane goes far away from vertex of slope with the increase of tensile strength. Foundation item: Project(20060533071) supported by the Doctoral Program Foundation of Higher Education of China; Project (20060400264) supported by China Postdoctoral Science Foundation; Project (50774093) supported by the National Natural Science Foundation of China; Project (1343-74236000014) supported by Graduate Student Innovation Foundation of Hunan Province, China     

One-pot synthesis and structural characterization of urea-isobutyraldehyde-formaldehyde resin

Urea-isobutyraldehyde-formaldehyde (UIF) resin was synthesized from urea, isobutyraldehyde, and formaldehyde using sulfuric acid as a catalyst by one pot method. The effects of molar ratios of isobutyraldehyde to formaldehyde (n(I)/n(F)) and aldehyde to urea (n(A)/n(U)) on the yield, hydroxyl value (vs KOH) and softening point of the resin were investigated. The structure of the resin was characterized by FT-IR, ¹H-NMR and ¹³C-NMR. The results show that when the molar ratio of urea to isobutyraldehyde to formaldehyde (n(U)/n(I)/n(F)) is 1.0/3.0/3.0, the yield UIF resin is 67.1%, and the softening point and hydroxyl value are 88 °C and 37 mg/g, respectively. The FT-IR, ¹H-NMR and ¹³C-NMR results show that the lactam is formed by aminomethylation from urea, isobutyraldehyde, and formaldehyde. Foundation item: Project(2006A10902001) supported by the Science and Technology Plan of Guangdong Province, China; Project(2007Z3-D0351) supported by the Science and Technology Plan of Guangzhou City, China     

Finite element analysis on nut post structure of Three Gorges Project ship lift

A nonlinear finite element model of the nut post reinforced concrete (RC) structure of the safety mechanism in the Three Gorges Project (TGP) ship lift was built by ANSYS software. Some irregular structures such as the nut post and the rotary rod were divided by curved surface into a series of regular parts, and the structures were all meshed to hexahedron. Constraint equations were defined between two interfaces with different element sizes and mesh patterns. PRETS179 elements were used to simulate the preload in the tendons and the pre-stressed screws, and the loss of pre-stressing force was calculated. Five extreme load cases were analyzed. The stress of each part in the structure was obtained. The results indicate that the maximum compressive stress of concrete C35 is 24.13 MPa, so the concrete may be partially crushed; the maximum tensile stress of the grouting motar is 6.73 MPa, so the grouting motar may partially fracture; the maximum von Mises stress of the rotary rod is 648.70 MPa, therefore the rotary rod may partially yield. Foundation item: Project (SPKJ 016-06) supported by the Key Research Project of State Power Corporation; Project (2004AC101D31) supported the Key Scientific Research Project of Hubei Province, China     

Constitutive equations and finite element implementation of strain localization in sand deformation

A recently proposed model coupling with the solid-fluid of the saturated sand was utilized to study the deformation band. Based on the critical state plasticity model by Borja and Andrade, the hydraulic conductivity tensor was naturally treated as a function of the spatial discretization matrix about the displacement and the stress field, allowing a more realistic representation of the physical phenomenon. The fully Lagrangian form of the Darcy law was resolved by Piola algorithm, and then the flow law was gained, leading to the implementation of a modified model of the saturated sand. Then the criterion for the onset of localization was derived and utilized to detect instability. The constitutive model was implemented in a finite element program coded by FORTRAN, which was used to predict the formation and development of shear bands in plane strain compression of saturated sand. At last, the formation mechanism of the shear band was discussed. It is shown that the model works well, and the simulation sample bifurcates at 1.18% axial strain, which is in a good qualitative agreement with the experiment. The pore pressure greatly affects the onset and development of the deformation band, and it obviously increases around the localization-prone regions with the direction toward the outer side of the normal of the shear band, while the pore stress flows nearly horizontally and is distributed equally far away the shear band region. Foundation item: Project(2006G007-C) supported by the Foundation of the Science and Technology Section of Ministry of Railway of China; Project(77206) supported by the Excellent PhD Thesis Innovation Foundation of Central South University, China     

Dynamic services selection algorithm in Web services composition supporting cross-enterprises collaboration

Based on the deficiency of time convergence and variability of Web services selection for services composition supporting cross-enterprises collaboration, an algorithm QCDSS (QoS constraints of dynamic Web services selection) to resolve dynamic Web services selection with QoS global optimal path, was proposed. The essence of the algorithm was that the problem of dynamic Web services selection with QoS global optimal path was transformed into a multi-objective services composition optimization problem with QoS constraints. The operations of the cross and mutation in genetic algorithm were brought into PSOA (particle swarm optimization algorithm), forming an improved algorithm (IPSOA) to solve the QoS global optimal problem. Theoretical analysis and experimental results indicate that the algorithm can better satisfy the time convergence requirement for Web services composition supporting cross-enterprises collaboration than the traditional algorithms. Foundation item: Project(70631004) supported by the Key Project of the National Natural Science Foundation of China; Project(20080440988) supported by the Postdoctoral Science Foundation of China; Project(09JJ4030) supported by the Natural Science Foundation of Hunan Province, China; Project supported by the Postdoctoral Science Foundation of Central South University, China     

Application of empirical mode decomposition based energy ratio to vortex flowmeter state diagnosis

To improve the measurement performance, a method for diagnosing the state of vortex flowmeter under various flow conditions was presented. The raw sensor signal of the vortex flowmeter was adaptively decomposed into intrinsic mode functions using the empirical mode decomposition approach. Based on the empirical mode decomposition results, the energy of each intrinsic mode function was extracted, and the vortex energy ratio was proposed to analyze how the perturbation in the flow affected the measurement performance of the vortex flowmeter. The relationship between the vortex energy ratio of the signal and the flow condition was established. The results show that the vortex energy ratio is sensitive to the flow condition and ideal for the characterization of the vortex flowmeter signal. Moreover, the vortex energy ratio under normal flow condition is greater than 80%, which can be adopted as an indicator to diagnose the state of a vortex flowmeter. Foundation item: Project(200801346) supported by the China Postdoctoral Science Foundation; Project(2008RS4022) supported by the Hunan Postdoctoral Scientific Program; Project(2008) supported by the Postdoctoral Science Foundation of Central South University     

Speciation of chromium in soil inoculated with Cr（Ⅵ）-reducing strain, Bacillus sp. XW-4

Cr(VI)-amended soil was inoculated with Cr(VI)-reducing strain, Bacillus sp. XW-4 and incubated at 28 °C in an incubator. Cr(VI) reduction, available Cr and Cr fraction in soils were studied. The results show that addition of Bacillus sp. XW-4 can promote Cr(VI) reduction, but inoculation of this strain has a negative effect on the decrease of available Cr content in soil. In controls (without this strain) amended with 100 and 200 mg/kg of Cr(VI), Cr(VI) contents decrease to about 41 and 92 mg/kg respectively after incubation of 4 d, while in soil inoculated with XW-4, Cr(VI) contents decrease to about 18 and 60 mg/kg, respectively. The content of available Cr in soils with inoculation of XW-4 is higher than that in controls. Chromium is partitioned into water soluble Cr, exchangeable Cr, precipitated Cr, Cr bound to organics and residual Cr. The highest content of Cr is observed in residual form and water soluble Cr is not detected for all treatments after 42 d, but the soils inoculated with Bacillus sp. XW-4 contain higher content of exchangeable Cr and lower content of precipitated Cr than the soil without the inoculum. Inoculation of Bacillus sp. XW-4 can increase chromium activity in soils. Foundation item: Project(20050532009) supported by the Doctoral Foundation of Ministry of Education of China; Project supported by Program for Changjiang Scholars and Innovative Research Team in University