基于振动压实模量的路基压实质量变异性控制优化研究

受波传播速度、信号混叠、局部应力分布、仪器限制等因素影响,当前智能压实测量值在下层强度相对较高时无法准确测量填充层的状态。为了解决该不足,本研究在填挖路基中进行实验性现场试验,评估智能压实测量值的变化特性。基于理论分析和数值模拟方法,提出1种新的智能压实测量值--振动压实模量,该模量能消除下层的干扰,揭示填充层的实际压实状态。并进一步提取该模量以研究填充层压实状态的变异性。研究结果表明,下层刚度对整体压实质量的影响显著,基于振动压实模量评估智能压实测量值更有可能实现填充层压实状态的变异控制。所呈现的测量数据、改进方法和相关结论为考虑使用智能压制技术的研究人员和从业人员提供宝贵的信息。

升压式开关直流调压器的不变性控制法

本文提出并分析了升压式开关直流调压器的一种不变性控制方法，它允许电源电压和负载电流在一定范围内变化而不影响输出电压值，而且该调压器的工作频率恒定。

基于尿素和STP控制修饰的大豆分离蛋白胶黏特性的研究

采用尿素和磷酸化试剂共同修饰大豆分离蛋白(SPI),主要研究不同浓度的多聚磷酸钠(STP)对经尿素控制变性后SPI胶黏强度、耐水性和二级结构的影响。先将SPI添加到3 mol/L尿素溶液中,SPI发生部分变性,然后再加入浓度为0、2%、5%、8%、10%的STP,对SPI进行磷酸化控制修饰。结果表明,STP浓度越大,其黏度越高。将经控制修饰的SPI应用在樱桃木、水曲柳和松木上的黏接后发现,STP能够提高胶黏强度和耐水性,当STP的浓度为5%时,其胶黏强度和耐水性达到最大值。SPI的圆二色性光谱图分析表明,磷酸化修饰后,SPI二级结构中的无规卷曲含量显著增加。对尿素和STP控制修饰SPI分子并提高其胶黏特性的机理也进行了探索。

含硫齿轮钢20CrMnTiH1钙处理热力学和控制技术的研究

通过钢液与夹杂物之间的热力学平衡计算,研究了20CrMnTiH1精炼钢水中Al_2O_3夹杂物钙处理后可能变性的程度和CaS夹杂生成条件。计算结果表明,[S]0.020%～0.035%、[Al]0.02%～0.04%的钢水进行钙处理时易生成稳定的CaS,并且铝脱氧的产物Al_2O_3难以完全变性成低熔点钙铝酸盐12(CaO)·7(Al_2O_3)。为使Al_2O_3完全变性成低熔点(CaO)·(Al_2O_3)和12(CaO)·7(Al_2O_3)钙铝酸盐,在精炼过程应在低[S]和温度≥1600℃情况下对钢水进行钙处理,软吹氩搅拌后进行喂硫线操作,同时可以显著减少水口堵塞的发生。

Z区块致密油水平井钻井液技术优化与应用

致密油是大庆油田的重要非常规油气资源,主要分布在青山口组和泉头组的扶杨油层,开发难度大。为了提高致密油水平井的钻井效率和安全性,介绍了大庆油田目前应用的几种钻井液技术,包括低固相氯化钾盐水钻井液体系、ULTRADRIL水基钻井液体系、油基钻井液体系等,分析了它们的理化性能和现场应用效果。针对以往施工存在的问题,对低固相氯化钾体系进行优化,现场应用表明该体系能够有效地解决致密油水平井的井壁稳定、泥饼质量、防塌防窜等技术难题,降低了钻井成本和环境污染,提高了致密油开发效益。

高密度饱和盐水钻井液在DN2-29H井的应用

库车山前深部巨厚盐膏层地质特征复杂,地层压力变化大,预测难度高。盐膏层钻井过程中,钻井液性能恶化,喷、漏、卡等复杂事故频发,严重影响安全快速钻井。针对以上难点,DN2-29H井以高密度饱和盐水钻井液体系为基础,引入新型材料稀释稳定剂,并优化了钻井液维护措施。实践证明,引入新型稀释稳定剂后,体系在盐膏层钻进过程中性能稳定,复杂工况明显降低,工期缩短,起下钻顺畅,电测、下套管均一次成功。本井经验对钻遇巨厚盐膏层具有重要的参考意义。

基于Petri网的离散事件系统控制理论

建立在Ｐｅｔｒｉ网逻辑模型上的离散事件系统控制理论是近年来发展起来的离散事件系统控制理论的重要组成部分，具有适应面广和易于实用化的特点．本文首先介绍该理论的Ｐｅｔｒｉ网模型，然后概述该理论的主要成果．

大豆分离蛋白性能优化关键技术

大豆分离蛋白的性能包括相容性和功能性 ,相容性决定了大豆蛋白的应用范围 ,功能性则最终反映大豆蛋白用户的收益大小。通过醇洗法脱除异味 ,选择性分离分级 ,控制蛋白质变性 ,蛋白质改性 ,以及干燥后处理可以改善大豆分离蛋白的相容性和功能性 ,并对它们的原理和方法进行了探讨。

Uniform asymptotics for finite-time ruin probability in some dependent compound risk models with constant interest rate

Consider two dependent renewal risk models with constant interest rate. By using some methods in the risk theory, uniform asymptotics for finite-time ruin probability is derived in a non-compound risk model, where claim sizes are upper tail asymptotically independent random variables with dominatedly varying tails, claim inter-arrival times follow the widely lower orthant dependent structure, and the total amount of premiums is a nonnegative stochastic process. Based on the obtained result, using the method of analysis for the tail probability of random sums, a similar result in a more complex and reasonable compound risk model is also obtained, where individual claim sizes are specialized to be extended negatively dependent and accident inter-arrival times are still widely lower orthant dependent, and both the claim sizes and the claim number have dominatedly varying tails.

ROBUST STABILIZATING FOR A OLASS OF UNOERTAIN NONLINEAR INTEROONNECTED SYSTEMS USING VARIABLE STRUCTURE CONTROL

The robust stabilizating control problem for a class of uncertain nonlinear large-scale systems is discussed. Based on the theory of both input/output (I/O) linearization and decentralized variable structure control (VSC),two-level and decentralized variable structure control laws for this kind of systems are presented respectively,which achieve asymptotically stabilization despite the uncertainties and disturbances. At last,sirnulation of the disturbed two-pendulum system is given to illustrate the feasibility of proposed technique.

Novel forward mode AC/AC converters with high frequency link

A circuit configuration and a circuit topologic family of the novel forward mode AC/AC converters with high frequency link are presented. The circuit configuration is constituted of input cycloconverter, high frequency transformer, output cycloconverter, input and output filters. The circuit topologic family includes eight circuit topologies, such as full-bridge-full-wave mode, etc. The bi-polarity phase-shifted control strategy and steady principles are thoroughly investigated. The output characteristics are obtained. By using the bi-polarity phase-shifted control strategy with phase-shifted control between the output cycloconveter and the input cycloconverter, commutation overlap period of the output cycloconverter, and polarity selection of the output filtering inductance current and the input voltage, the leakage inductance energy and the output filtering inductance current are naturally commutated, and surge voltage and surge current of the cycloconverters are overcome. The converters have such advantages as simple topology, two-stage power conversions(LFAC/HFAC/LFAC), bi-directional power flow, high frequency electrical isolation, good output waveforms, and strong ability to stabilize voltage. The converters lay key technical foundation on a new-type of regulated sinusoidal AC power supplies and electronic transformers. The correction and advancement of the converters are well verified by a principle test.

中秋区块ZQ2井盐膏层水基钻井液技术

中秋区块为塔里木油田3000万吨产能建设重点区块。塔里木油田山前井盐膏地层因地质条件复杂,普遍使用油基钻井液钻井。ZQ1井盐膏地层亦使用油基钻井液,因新近系苏维依组存在低压层,在钻进过程中发生井漏,使用油基钻井液堵漏成功率低,耗时达60多天。为有效解决油基钻井液盐膏层阻卡、堵漏成功率低、钻井液成本高等问题,决定在ZQ2井吉迪克组高压盐膏层和苏维依组低压易漏层采用水基钻井液套打技术。ZQ2井盐膏层水基钻井液技术有效解决了吉迪克组"盐、膏、泥"污染导致的钻井液流变性和失水造壁性控制难的问题,采取主动防漏技术顺利钻穿苏维依组低压易漏层,未出现盐间"软泥岩"堵地面管汇的问题,钻井液性能稳定,井眼畅通。该技术为加快塔里木油田3000万吨产能建设提供了新的可行的钻井液技术思路。

昆明枢纽扩能改造下穿通道基坑支护工程设计研究

昆明枢纽沿线软土发育范围广、深度大、成分复杂,工程地质条件、水文地质条件极为复杂。枢纽扩能改造工程下穿通道基坑多毗邻既有铁路、军事管制区、市政道路及高层建筑物等,变形控制要求高、难度大。复杂敏感环境下软土深基坑的支护设计及变形控制成为扩能改造工程的设计难点。本文在搜集、分析昆明地区既有基坑工程案例经验教训的基础上,归纳总结了影响昆明枢纽基坑工程安全的关键性因素,研究了软土基坑中围护结构、内支撑的受力变形特征,揭示了基坑施工对临近设施影响的作用机理,提出了"防渗水、保安全、控变形、重监测"的基坑设计原则,形成了复杂敏感环境下软土基坑加固及变形控制成套技术,可为未来昆明地区基坑工程的安全设计提供理论支撑。

新型H型钢支撑工程应用分析

本文以南京某基坑工程为例,探讨了一种新型H型钢支撑在基坑工程中的应用,并与传统钢管支撑的应用效果进行对比。工程实例的成功应用表明:新型H型钢支撑技术比传统钢管支撑技术控制基坑变形的效果好;新型H型钢支撑主要为螺栓连接,与传统钢管支撑的焊接连接相比操作简单,工期更短,钢材寿命更长;新型H型钢支撑在基坑工程中的应用具有可行性,可为相似工程提供参考。

Microcomputer Controlled High Precision Image Scanning Systems for Railway Tunnel Width Measurement

There should be high resolution demand that is better than 1000 DPI(dot per inch) for high precision image scanning system. This paper introduced the two-level computer controlled system that consisted of LS-3500 film scanner, AST386/33 monitoring control level and Intel 8031 single chip computer that is used as DDC level. The formula for scanning image data processing and methods of statistic parameters calculating are described.

Compliant landing of a trotting quadruped robot based on hybrid motion/force robust control

A compliant landing strategy for a trotting quadruped robot on unknown rough terrains based on contact force control is presented. Firstly, in order to lower the disturbance caused by the landing impact force, a landing phase is added between the swing phase and the stance phase, where the desired contact force is set as a small positive constant. Secondly, the joint torque optimization of the stance legs is formulated as a quadratic programming(QP) problem subject to equality and inequality/bound constraints. And a primal-dual dynamical system solver based on linear variational inequalities(LVI) is applied to solve this QP problem. Furthermore, based on the optimization results, a hybrid motion/force robust controller is designed to realize the tracking of the contact force, while the constraints of the stance feet landing angles are fulfilled simultaneously. Finally, the experiments are performed to validate the proposed methods.

Mechanical model of control of key strata in deep mining

Based on the characteristic of deep rock layers and the theory of key strata,we analysed elastic mechanical characteristics of key strata by using elastic plate theory.The results show that the deformation and distribution of internal forces of key strata vary with different mine boundary conditions.The boundary values of key strata with three point boundaries and one fixed boundary is greater than that with four fixed boundaries.Considering the rheology of key strata under low stress conditions,we selected a generalized Kelvin model to analyse the rheology characteristics of the key strata and discovered their instantaneous elastic phases.The rate of deformation decreased over time to the point where the key strata reached stability.But over this time,the effect on deformation became very clear. For high stress conditions,we chose a Burgers model and found deformation of key strata in the form of attenuation and steady-state creep and although the rate of deformation remained constant,secondary creep was obvious,causing instability in the system.As well,we analysed the effect of creep buckling and derived a relation between buckling force and time.

Performance Monitoring and Diagnosis of Multivariable Model Predictive Control Using Statistical Analysis

A statistic-based benchmark was proposed for performance assessment and monitoring of model predic- tive control; the benchmark was straightforward and achievable by recording a set of output data only when the control performance was good according to the user’s selection. Principal component model was built and an auto- regressive moving average filter was identified to monitor the performance; an improved T2 statistic was selected as the performance monitor index. When performance changes were detected, diagnosis was done by model validation using recursive analysis and generalized likelihood ratio (GLR) method. This distinguished the fact that the per- formance change was due to plant model mismatch or due to disturbance term. Simulation was done about a heavy oil fractionator system and good results were obtained. The diagnosis result was helpful for the operator to improve the system performance.

Comparative analysis of online monitoring methods for transformer insulation performance of 330-750kV substation

The online-monitoring methods for insulation performance of current transformers of 330-750 kV substation are analyzed and compared.The effectiveness and availability of each method are discussed.Main features,advantages and disadvantages of each method and its corresponding standard are also described.