定量包装商品净含量计量检验方法的探讨

为保证定量包装商品净含量计量检验结果的统一性、有效性和准确性,依据JJF 1070-2005《定量包装商品净含量计量检验规则》,对影响定量包装商品净含量检验结果的不确定度的主要来源和检验的关键点进行分析,找出每种检验方法中影响净含量检验结果的测量不确定度,为今后科学地计量检验定量包装商品净含量奠定基础。     

浅述工程造价计价法

从定额计价模式与工程量清单计价模式的区别、联系以及由此引发的思考三方面进行了分析,简要阐述了两种计价模式的发展趋势,旨在通过合理选用计价模式,有效控制工程造价。     

港口液体化学品废水处理工程实例

液体化学品废水有毒有害物质多,水质波动大.采用隔油气浮/曝气生物滤池蠕动床/臭氧氧化/曝气生物滤池固定床组合工艺进行处理,COD由进水的1 200 mg/L左右降到100 mg/L以下,SS由进水的600 mg/L左右降到30 mg/L以下,出水水质达到<污水综合排放标准>(GB 8978-1996)的一级标准,可回用作生活杂用水.实际运行结果表明,该组合工艺有效、稳定,污泥产量少,可操作性强,有很好的环境效益和经济效益.     

Fast Training of Structured SVM Using Fixed‐Threshold Sequential Minimal Optimization

In this paper, we describe a fixed‐threshold sequential minimal optimization (FSMO) for structured SVM problems. FSMO is conceptually simple, easy to implement, and faster than the standard support vector machine (SVM) training algorithms for structured SVM problems. Because FSMO uses the fact that the formulation of structured SVM has no bias (that is, the threshold b is fixed at zero), FSMO breaks down the quadratic programming (QP) problems of structured SVM into a series of smallest QP problems, each involving only one variable. By involving only one variable, FSMO is advantageous in that each QP sub‐problem does not need subset selection. For the various test sets, FSMO is as accurate as an existing structured SVM implementation (SVM‐Struct) but is much faster on large data sets. The training time of FSMO empirically scales between O ( n ) and O(n^1.2), while SVM‐Struct scales between O(n^1.5) and O(n^1.8).     

一种配置有固定波长变换器的OPS节点性能分析

提出一种新型的光分组交换（OPS）节点结构,即OFBFWC（Optical packet switch with Feedback Buffer and Fixed Wavelength Converter）交换结构,它使用固定波长变换器和反馈式的光缓存来解决光分组的冲突。为了提高OFBFWC的性能,还提出一种有效的控制算法。最后,使用仿真实验的方法对OFBFWC的性能进行评估。     

XGL-2×3型三通道固定流化床催化裂化实验装置的构造与运行

介绍了XGL-2×3型三通道固定流化床催化裂化实验装置的组成、工艺流程及运行情况。在调试和试运行过程中曾出现裂化气产率的平行性较差、水泵出口压力偏高、再生烟气红外分析仪出现偏差等问题，采取适当措施后装置可稳定运行。催化剂评价及工艺条件考察效率比单套固定流化床装置高2倍。试用结果表明：干气、液化气、汽油、柴油、重油、焦炭收率最大相对误差分别为1．47％，0．78％，0．37％，0．25％，1．55％，1．25％；产物总收率最大相对误差为0．16％。     

固定式喷灌系统经济管径的计算方法

在分析了固定式喷灌系统的管网投资、年运行费用与管径函数关系的基础上，利用工程经济分析中费用最小化准则和非线性规划理论，建立了求解喷灌系统管网经济管径的数学模型，并给出了无约束条件直接求解经济管径的计算式．     

一种新型三维微位移工作台的设计和分析

为了解决微位移工作台的三维耦合问题,设计了一种驱动器固定的三维无耦合微位移工作台.本文介绍了它的结构和工作原理,通过有限元分析计算和样机实测验证,分别在X方向,X、Y方向和X、Y、Z方向施加载荷时,三维微位移工作台在X方向的位移不变,解决了三维空间运动耦合问题;分别在X、Y、Z方向施加不同载荷时,得到了工作台X、Y、Z方向的刚度,验证了工作台的位移、最大等效应力与载荷成正比.样机实测结果与有限元计算结果相吻合,工作台符合设计要求.     

Power Electronic Interface with Maximum Power Point Tracking Using Line-commutated Inverter for Grid-connected Permanent Magnet Synchronous Generator

Abstract—This article presents a simple grid interactive system that extracts maximum power from a wind-driven permanent magnet synchronous generator using an integrated cascade boost converter and a three-phase line-commutated inverter. The firing angle of the line-commutated inverter is held constant at an appropriate value that provides a constant DC-link voltage, and only DC-link current is sensed for maximum power point tracking. For wide wind variation, maximum power from the permanent magnet synchronous generator is achieved using a simple load current (DC-link current) perturb and observe maximum power point tracking technique. This is obtained by varying the duty ratio of the integrated cascade boost converter with an adaptive incremental step that varies the load on the permanent magnet synchronous generator in accordance with changing wind. Experiments have been conducted on a 3-phase, 750-W, 500-rpm laboratory size permanent magnet synchronous generator. The operation and analysis of the proposed topology with a fixed firing angle for a line-commutated inverter is presented. The results obtained from MATLAB (The MathWorks, Natick, Massachusetts, USA) simulation are verified with experimental results, and a close correlation has been found, proving the efficacy of the system.     

关于一种新型映射及拟非扩展映射的Mann—Ishikawa迭代格式的收敛性

在Ｈｉｌｂｅｒｔ空间上，证明了拟非扩展映射的不动点可用Ｉｓｈｉｋａｗａ迭代格式来逼近。引进一种新型映射，并且的Ｈｉｌｂｅｒｔ空间中首次对这类映射讨论其Ｉｓｈｉｋａｗａ迭代格式的收敛性。