燃油油品对电喷柴油机的影响及应对措施

随着电喷柴油机在国内工程机械上使用量的增多,因燃油油品问题而造成的柴油机故障越来越多.从电喷柴油机原理、国内外油品标准以及施工环境等角度分析其产生原因,并从工程机械使用和设计等角度提出一些应对差油品燃油的实用性措施.     

Virtual Network Mapping Through Locality-aware Topological Potential and Influence Node Ranking

Efficiently mapping multiple independent Virtual networks （VNs） over a common infrastructure sub- strate is a challenging problem on cloud computing plat- forms and large-scale future Internet testbeds. Inspired by the idea of data fields, we apply a topological poten- tial function to node ranking and propose an algorithm called Locality-aware node topological potential ranking （LNTPR）, which can precisely and efficiently reflect the relative importance of nodes. Using LNTPR and the con- cept of locality awareness, we develop the Locality-aware influence choosing node （LICN） algorithm based on a node influence model that considers the mutual influence be- tween a mapped node and its candidate mapping nodes. LNTPR and LICN improve the integration of node and link mapping. Simulation results demonstrate that the proposed algorithms exhibit good performance in deter- mining revenue, acceptance ratio, and revenue/cost ratio.     

压水堆SBLOCA事故环路水封清除现象机理与模型影响研究

环路水封清除（LSC）是压水堆冷管段小破口失水事故（SBLOCA）的典型事故特征之一。为确定LSC现象的物理模型影响,探究准确复现LSC现象的物理模型设置,从LSC现象物理机理的角度,对影响LSC的主要物理模型进行梳理和分析。结合LOBI台架SBLCOA系列实验,对LSC现象物理机理、物理模型影响进行模拟和验证。结果表明,在对影响LSC现象的物理模型进行合理设置后,RELAP5程序模型能较好地复现LOBI台架实验工况中的LSC现象,验证了LSC现象物理模型影响及模型设置的合理性。      

Estimating the uncertainty in the estimated mean area under the ROC curve of a classifier

This article considers the problem of binary classification and its assessment in a distribution-free approach. We estimate the area under the ROC curve (a more general performance metric than the error rate) of a classifier using a bootstrap-based estimator. We then use the method of the influence function to estimate the uncertainty of that estimate from the very same bootstrap samples. Monte Carlo trials show that small-sample estimates can be obtained with little bias.     

An accuracy improvement for balancing crankshafts

Due to measurement errors, the final accuracy of rotor balancing may not be satisfied. This study is based on a modified influence coefficient method associated with multi-plane technique for the improvement of accuracy in balancing crankshafts. This method extends the conventional influence coefficient method, in which two trial masses in one balancing plane are employed, to one utilizing three trial masses in one plane. On the basis of three trial runs, the balancing accuracy can then be improved by the optimization of influence coefficient matrices resulting from the minimization of measurement errors. The feasibility of this modified approach is carried out by the verification of accuracy improvement in experiments, balancing two crankshafts.     

转子动平衡的几个优化算法

介绍了影响系数法，影响系数余量法，定相位角最佳算法，单平面加重的优化搜索法及优化影响系数法等转子动平衡的计算方法及其各算法的MATLAB应用程序。实际的算例验证了各程序的正确性与有效性，证明了通过计算得到的多种配重方案可给平衡工作提供更多的选择空间，有利于提高平衡工作的质量、效率和降低成本。     

钻井液润滑剂对录井资料的影响因素分析

现场钻井过程中,钻井液中加入润滑剂后,使现场综合录井受到一定的影响。本文通过现有的分析方法,对其进行分析、判别、解释,从而为综合解释排除了影响因素,提供了真实可信的数据。     

车刀安装高度对加工误差的影响

在数控车床外圆车削中，当车刀刀尖安装高度不在工件中心水平面上时，将会引起径向进刀误差，从而产生车削直径误差。文章给出了刀尖安装高度ｈ对车削台阶工件直径影响值δ的计算公式。     

煤层气区评价参数及勘探方向

煤层气勘探选区评价的关键参数是煤层的含气量和渗透率。沉积作用、成岩作用、构造作用和封闭作用地这两个参数有影响。基于对各地持因素的综合分析，认为目前煤敢探重点区域应是华北，其次是华南；重点选区为鄂我斯贫地国中部低煤阶区、鄂尔多斯盆地东部中煤阶区、沁水盆地环斜坡带中一高煤阶区、豫西向斜带高煤阶区、钱西－濮阳斜皮带中煤阶区，冀中－冀东斜坡带中煤阶区、淮南－－淮北复向斜断块区中煤阶区和六盘水梳状褶皱复向斜     

九龙江北溪水电站建设对下游干流枯水径流影响

九龙江是福建省第二大河流,北溪是龙岩、漳州和厦门三市的重要水源地,北溪下游干流的枯水流量大小不仅影响干流河道的生态用水和纳污能力,而且直接影响到漳州市和厦门市的饮用水安全。本文通过北溪主要水电站工程对干流的枯水期平均流量、最小月平均流量及最小日平均流量的影响原因和影响程度分析,为北溪枯水期水量调度提供参考。