柴油机气缸组件与燃烧系统故障的诊断方法

文中探讨一种船用二冲程主柴油机气缸活塞组件与燃烧系统故障诊断的方法,即基于径向基函数神经网络模型的诊断方法,对该系统的征兆、故障样本集进行设计;采用ＭＡＴＬＡＢ语言编制仿真程序,然后以ＨＵＤＯＮＧ－Ｂ＆Ｗ ６Ｌ６０ＭＣＥ型大功率船用低速柴油机气缸级件与燃烧系统故障的模拟计算为例来说明这种诊断方法的可行性。     

Fault Detection Observer Design for LSFDJ： A Factorization Approach

Based on a new special co-inner-outer factorization, a factorization approach for design fault detection observer for LSFDJ was proposed. It is a simple state-space method and can deal with time varying LSFDJ with sensor noise and sensor faults. The performance of the fault detection observer is optimized in an H∞ setting,where the ratio between the gains from disturbance and fault to residual respectively is minimized. The design parameters of the detection observer were given in terms of the solution to the Riccati differential equation with jumps.     

球面瞬态声辐射的全息重构研究

由于声源体受到冲击而振动的持续时间很短,这种情况下声源体向空间中辐射声波的过程不能看做稳态的过程,不再适用稳态声全息理论.本文采用球面瞬态声全息的模型,对自由空间中受到冲击的球产生声辐射的过程进行数值仿真,仿真中分别采用Tikhonov正则化方法和共轭梯度法处理运算中遇到的矩阵病态和解不稳定的问题,并对仿真结果进行对比分析.结果表明,在一定的容许误差范围内,2种方法都适用.     

采用相关分析法计算清远站最低通航水位

在水位～流量关系不断变化的过程中,采用规范的方法进行统计分析是不合适的.北江清远站水位在2003年以后,急剧下降,缺乏流量资料.上游飞来峡站距离清远站较近,且中间没有支流汇入,两站的水文条件较为相似.所以考虑在飞来峡站的流量系列基础上,根据流量与上下游水位之间的相关对应关系寻找切合实际的计算方法.     

沪通长江大桥水下自密实混凝土工作性能试验研究

通过流动性试验、间隙通过性试验、流变性能试验和灰色关联度分析,研究了胶凝材料用量、水胶比、砂率、粉煤灰掺量等因素对水下自密实混凝土工作性能的影响。试验结果表明:当水胶比在0. 36～0. 38,胶凝材料用量在440～480 kg/m3,砂率为50%,粉煤灰掺量在35%～45%时,混凝土的屈服应力和塑性黏度较小,流动性及间隙通过性较为优异,综合分析确定了最优的混凝土配合比;胶凝材料用量和水胶比是影响混凝土工作性能的主要因素,而砂率和粉煤灰掺量对混凝土工作性能的影响相对较小;混凝土流动性对V形漏斗流出时间最为敏感,对坍落扩展时间和倒置坍落度筒排空时间的敏感性差别不大;提出了低胶凝材料用量、高体积稳定性的水下自密实混凝土制备方法,为沪通长江大桥及同类超大深水基础复杂结构工程水下自密实混凝土的制备提供了试验和理论依据。     

造船质量数据库管理技术研究

目前大部分造船企业在船舶建造过程中质量数据管理不规范,不利于质量改进和创立质量品牌。本文通过质量技术研究,提出质量数据分析采用的质量管理工具,促进有效开展质量改进,按属性规范质量数据管理,理清企业内管理责任,为打造船舶品牌创造条件。     

船舶二冲程主柴油机增压器喘振故障诊断方法探讨

提出一种船用二冲程增压柴油机喘振故障的诊断方法。根据监测热工参数采用微机诊断软件可迅速查出喘振的主要原因。     

Convective Boiling of Near-Azeotropic Refrigerant R410A in the Horizontal Micro-fin Tube

Using near-azeotropic refrigerant R410A as the working fluid, the experimental studies on the horizontal micro-fin tubes were conducted. Several factors affecting heat transfer coefficients were analyzed, and the characteristics of flow boiling of the refrigerant in the horizontal micro-fin tubes were discussed. The local heat transfer coefficients increase with mass flux, heat flux and quality. And the heat transfer enhancement factor of those testing tubes is about 1.6 to 2.2.     

Multimodal Evolution Approach to Multidimensional Intrusion Detection

An artificial immunity based multimodal evolution algorithm is developed to generate detectors with variable coverage for multidimensional intrusion detection. In this algorithm, a proper fitness function is used to drive the detectors to fill in those detection holes close to self set or among self spheres, and genetic algorithm is adopted to reduce the negative effects that different distribution of self imposes on the detector generating process. The validity of the algorithm is tested with spherical and rectangular detectors, respectively, and experiments performed on two real data sets （machine learning database and DAPRA99） indicate that the proposed algorithm can obtain good results on spherical detectors, and that its performances in detection rate, false alarm rate, stabih＇ty, time cost, and adaptability to incomplete training set on spherical detectors are all better than on rectangular ones.     

大学系主任角色行为研究

由于受多种角色期待的制约，大学系主任与其他学术人员和管理人员 相比存在更多的角色紧张和角色冲突。系主任本人及相关管理部门应根据系主任角色行为的特点，正确评价系主任的工作。