稀土在激光熔覆镍基自熔合金中的作用

采用CO2激光器在低碳钢表面进行激光熔覆处理,研究了稀土氧化物在激光熔覆Ni45自熔合金层中的作用.结果表明,加入适量稀土的熔覆合金层组织得到细化,其在还原酸中的耐蚀性和抗高温氧化能力较不加稀土镍基合金熔覆层都有较大提高,更远高于低碳钢.可见,稀土变质的激光熔覆处理对提高低碳钢性能具有重要指导意义.     

炼油厂全流程优化建模方法研究

为了克服使用线性规划和单处理单元非线性规划进行生产优化的内在缺点，在建立原油单元、催化裂化、催化重整和汽油调合等4个重要处理单元详细模型的基础上，将单处理单元非线性过程模型集成到一个全流程优化非线性模型中。优化的目标函数是使炼油厂全厂利润最大。决策变量是那些显著影响全厂效益的变量，约束条件是单个处理单元约束条件的集合。对某炼油厂进行实例研究，结果表明该全流程模型能有效处理全厂优化问题，所得利润在线性规划的基础上提高4．5％。     

营尔凹陷下白垩统油气勘探应避开高压水层

营尔凹陷下白垩统(K₁₎存在下沟组和赤金堡组2套源岩，目前它们已到成熟阶段。凹陷东侧长沙岭构造在下白垩统下沟组和赤金堡组储层中也发现油藏，但主要分布在高压水层的顶部及下部，而高压水层段存在良好的储层，并未发现油气。文章根据高压水层段的储层荧光特征，通过储层烃与源岩的对比，分析了下白垩统高压水层对油气运移的影响。研究结果表明：高压水层段，储层荧光弱，储层抽提物特征既不同于赤赤金堡组源岩，也不同于下构组源岩，为就近捕获的产物；高压水层未发生大规模的油气运移，其形成时间早于油气运移的时间。建议该区油气勘探目标的选择应避开高压水层，选择凹陷附近的圈闭、高压水层以下的层位。     

相关条件下基于N-P准则的分布式检测理论研究

本文针对并行网络、二元局部判决的情况,研究了在相关条件下基于N-P准则的分布式检测融合算法,给出了在联合概率密度已知和未知两种情况下的最优融合规则的理论推导及相应的解决方案,并在实验仿真的基础上,得到了部分有益的结论。     

炼油厂碱性污水生物催化氧化预处理工艺研究

在对炼油厂碱性污水水质分析的基础上,提出采用生物催化氧化工艺对碱性污水进行预处理。试验结果表明,在水力停留时间为4 h,曝气量(标准状态)为8 m3／h的条件下,碱性污水的硫化物去除率可达90％以上,出水中的硫化物平均值为15．2 mg/L,CODCR、酚和油的去除率分别为47．5％,44．1％,50．8％,其中CODCR体积负荷为3．85 kg／(m3·d),是传统生化处理的10倍, 达到了污水预处理的目的。     

人工智能的原理及应用

介绍了人工智能的发展，并对改进的神经网络专家系统的优越性做了介绍，指出了神经网络专家系统广阔的应用前景及实现。     

Supply-side hurdles in Internet B2C e-commerce: an empirical investigation

Given Hong Kong's special circumstances of small physical size, advanced infrastructure, and low shopping cost, a survey is designed under which supply-side problems in Internet business-to-consumer (B2C) e-commerce are indirectly revealed by responses on the demand side. Difficulties arising from the reluctance to answer questionnaires on the part of e-firms wary about trade and innovation secrets and their small number at the outset are thereby overcome. Survey data on demand-side obstacle factors in the form of perceived low e-shopping comparability, e-shopping inconvenience, e-transaction insecurity, and poor Internet privacy, together with orientation toward social interaction and low awareness on the part of consumers, translate into information on notionally matching supply-side hurdles. Regression analysis and hypothesis testing indicate statistical significance for the above hurdle factors in terms of impact on individual unwillingness to shop online. These results add to the inductive basis for future research into a general demand-supply theory of Internet B2C e-commerce and offer an empirically-grounded position against which the effects of later supply-side changes can be evaluated. Useful information also follows for engineer-managers seeking to compare marginal improvements in supply-side problems, particularly in the form of estimated substitution ratios.     

Modeling node mobility for reliable packet delivery in mobile ip networks

In this paper, we analyze node mobility for reliable packet delivery in mobile IP networks. In mobile IP, packets destined to roaming nodes are intercepted by their home agents and delivered via tunneling to their care of addresses (CoA). A mobile node may roam across multiple subnets. At each boundary crossing, a handoff is initiated such that the CoA is updated and a new tunnel is established. We consider both basic mobile IP handoff and smooth handoff. We find that reliable packet delivery in mobile IP networks can be modeled as a renewal process, because the retransmission over a new tunnel after each boundary crossing is independent of the previous history. We then derive the probability distribution of boundary crossings for each successful packet, based on which the packet reliable delivery time can be obtained. Our analytical model is derived based on a general distribution of residence time in a subnet and a general distribution of successful retransmission attempts in each subnet. The results can be readily applied to any distributions for both items. We also provide numerical examples to calculate the probability distribution of boundary crossings, and conduct simulations to validate our analytical results     

基于ERP系统的电子商务平台的分析

提出了利用DNA和XML技术构建基于ERP系统的电子商务平台的解决方案，并且给出了数据接口的几种实现方式。     

Ripple: a wireless token-passing protocol for multi-hop wireless mesh networks

This work presents a wireless token-passing protocol, named Ripple, for wireless mesh networks (WMNs). In contrast to existing random-access approaches, Ripple uses a decentralized controlled-access approach to protect nodes from unintentional packet collisions and maximize the spatial reuse. The performance of Ripple under an error-free wireless channel was investigated and the accuracy of the analysis was verified by simulation. Simulation results also indicated that Ripple achieved throughput, stability, and QoS enhancement than that of 802.11 DCF under a highly loaded situation.