乳化液废水处理浅议

介绍了乳化油在水中的存在形态，结合化学法处理乳化废液中乳化油的处理机理，对乳化液的具体处理工程进行了探讨，提出了使设备投资和工程造价显著降低的措施。     

GPS在城市控制测量应用中的几点体会

文章以阜阳市G PS控制网改造为例,从G PS网的构成、观测、数据处理、精度评定等方面加以论述,对G PS在城市控制测量中的优越性与实用性等问题作了相关探讨。     

附不等式约束的病态问题求解研究

病态问题产生的原因是设计矩阵存在复共线关系,为了消除法方程奇异,我们必须附加先验信息。不等式约束是客观实际中普遍存在的一种约束,是先验信息的主要表达方式之一,因此本文提出了附不等式约束的病态问题和其求解方法。本文在Rao提出的椭球约束法的基础上导出了不等式约束条件和广义岭参数之间的转换关系,然后用传统的广义岭估计来求解附不等式约束的病态问题。该种求解思想真正实现了由附加先验信息来决定岭参数。最后用一个模拟的算例检验了本文方法的可行性。同时,算例表明:不等式约束条件越正确、越苛刻得到的结果越接近真值,精度也越高。     

钢网在墙体抹灰砂浆塑性阶段抗裂性能试验研究

针对墙体抹灰砂浆上墙后易出现裂缝的工程现状,选择了几种典型的镀锌钢网,通过加速试验手段进行抹灰砂浆抗裂性能试验,比较和分析了不同规格钢网抵抗砂浆塑性阶段裂缝效果的差异,为合理选用墙体防裂钢网提供了有益的数据和资料。     

雅可比矩阵引导的无翻转体映射生成

目的 体映射建立了两个3维体网格之间的对应关系,是计算机图形学中的重要研究方向。很多应用要求体映射是无翻转的,即其雅可比矩阵的行列式处处大于0。然而,现有的无翻转体映射生成算法经常无法完全消除翻转。挑战主要在于很难在保证满足位置约束的前提下消除映射的翻转。为此,提出一种新的无翻转体映射计算方法,核心是一种新的变形方法。方法 首先放松位置约束,然后在变形过程中通过线搜索的方式保证不产生翻转,最后将网格无翻转地变形到满足位置约束。为实现这个变形过程,提出一种雅可比矩阵引导的变形算法。虽然现有的无翻转体映射方法不能完全消除翻转,但其雅可比矩阵可以作为本文变形算法的指导。此外,优化了位置能量,使得变形网格最终能够满足位置约束要求。为了满足体映射低扭曲的要求,算法最后在固定位置约束的前提下进一步优化了体映射的扭曲能量。结果 对大量复杂网格进行实验,本文算法能够保证生成无翻转的体映射,并且通过多步优化最终结果均能满足给定的位置约束要求。结论 通过与现有其他算法的优点和局限性对比,结果表明本文算法具有较好的鲁棒性。本文算法从一个全新的角度促进了无翻转体映射生成技术的进步与发展。     

Optimum stiffened panel design with fundamental frequency constraint

A generic analysis/design method for prismatic plate assemblies, using exact plate stiffnesses which are transcendental functions of loading and/or vibration frequency, has long been validated by the established program . Hitherto vibrations were permitted only in analysis because design uses the Wittrick–Williams algorithm to modify the design predicted by a linear optimiser to be ‘just stable’ by scaling all layer thicknesses by F. This works because buckling loads, unlike the fundamental frequency f₁, vary monotonically with F. The paper considers additionally scaling all plate breadths by F^α such that the buckling loads and f₁ all vary monotonically with F. Theoretical consideration of simple limiting cases establishes bounds on the permitted values of α as 0.1≤α≤0.4. Then results for typical stiffened panels demonstrate the method to be correct and are used to investigate the value of α which is most effective in returning stabilised designs of least mass and with least computation.     

Prediction of brittle fracture initiating at ends of CJP groove welded joints with defects: study into applicability of failure assessment diagram approach

A series of tests, which reproduced brittle fracture starting from the region around the terminations of complete joint penetration groove welded joints, was conducted. The joint models under study represented a portion of welded beam flange-to-through diaphragm joints in beam-to-column connections. Various artificial weld defects were installed in the welded joints prior to testing. Test results were evaluated based on the failure assessment diagram approach specified in BS 7910. The conventional failure assessment diagrams predicted occurrences of brittle fracture erring on the very conservative side as expected, especially when applied to surface defects. The failure assessment diagram approach was modified by considering the effect of enhanced apparent toughness of material due to the loss of crack tip constraint. The modified failure assessment approach was found to predict the test results well.     

恒模信号波达方向和阵列天线互耦系数的联合估计算法

提出了1种针对恒模信号的波达方向和阵列天线互耦系数的联合估计算法。新算法不需要方位已知的辅助校正源,可以在线完成实际信源的方位估计。仿真结果证明了新算法的估计精度取决于信源的信噪比、方位组合和快拍数等因素。     

考虑污染物排放约束的传统电厂与虚拟电厂间环境经济调度模型

为有效实现分布式能源(distributed energy resource,DER)单元参与电力系统能源市场,深度挖掘负荷侧灵活供能潜力,首先建立虚拟电厂(virtual power plant,VPP)作为管理运行分布式能源的代理模型,并基于组件特性分析对虚拟电厂的外特性进行了量化;然后基于当前电力行业面临的经济环境热点问题,建立了考虑污染物排放约束的传统电厂(conventional power plant,CPP)和虚拟电厂间的环境经济调度(environmental economic dispatch,EED)二阶约束二阶规划(quadratically constraint quadratic programming,QCQP)模型;接着介绍了CPLEX优化引擎和YALMIP软件包的功能,并采用建模与求解解耦的方式来求解模型;最后对改进10机系统进行仿真计算,验证了所提模型的有效性和正确性。