复杂信道环境下的多维策略智能抗干扰技术

针对当前智能抗干扰技术策略维度低、复杂环境应对性差的问题,提出了适应复杂环境的多维策略智能抗干扰技术。将单音信号作为探测信号,通过扫频方式减少探测阶段复杂度以实现快速实时的环境状态特征提取,之后设计了基于深度神经网络的实时智能决策引擎模型以提高决策速度和准确率。仿真结果表明所提方案能够准确地预测通信质量,最后根据目标函数在所有可通信策略中决策出最优策略,当探测信号扫频间隔选取合适时,该方案能够达到接近96%的决策准确率及较好的资源利用率,能有效进行抗干扰并取得较好的通信质量。     

一种十字形缝隙耦合的Ku波段宽频带双极化微带天线

采用十字缝隙耦合,层叠贴片和微带线馈电的结构形式,设计了一种适用于Ku波段的宽频带双极化微带天线。利用电磁仿真软件CST 5.0微波工作室对天线的电特性进行仿真优化,并制作了实物模型,实测结果和仿真结果吻合良好。两馈电端口回波损耗小于-10 dB的阻抗带宽分别达到34.2%和28.7%,端口隔离度高于21.4 dB。     

Computer Aided Tolerance assignment

Tolerances are basic to the production of every part. This is because perfect parts cannot be produced with existing processes and machines. The determination of tolerances for the individual parts of a functional assembly is critical, but not trivial. Numerous approaches are suggested in past literature for (analytical) tolerance allocation. With the advent of total automation, more attempts are being made to computerize manual design tasks. Tolerance design, assignment and allocation can also be fully automated if the assembly function can be estimated by the computer.

In the present paper, an attempt is made to computerize tolerance assignment. A simple example of a two piece assembly, viz., a fit, is used to demonstrate the developed methodology. A feature extraction is first performed from both detail and assembly drawings. Then, probable assembly interfaces are determined using a rule based procedure. Consequently, tolerances are assigned to the basic dimensions of each feature and to the assembly interfaces using a tolerance database and user interaction. More complex analysis for tolerance allocation is also under study.     

浅议中国城市化的多元化

城市化是近现代引人注目的社会经济现象,也是世界各国经济发展的必然过程。目前在全球经济一体化,信息技术飞速发展的宏观背景下,城市的经济力量和作用正逐渐得到进一步的加强,城市在国民经济以至世界经济中的地位和影响愈来愈重要,并且城市化也给城乡居民的生活方式打上了明显的烙印。因此,对中国城市化发展的研究,具有十分重大的现实意义和广阔的研究背景。     

Cut-tree construction for facility layout

The Gomory-Hu cut tree corresponding to a material flow graph provides important structural relationships to layout designers. The cut tree generation is not trivial to the programmer. In this paper, we present a simple technique which generates and constructs a cut tree of a given flow graph. The method differs from previous cut tree generation methods in the sense that its output also facilitates computer construction of the graph of the cut tree with only a few lines of additional coding, which makes its implementation attractive for computerized graph theoretic layout design approaches. The algorithm actually draws the cut tree automatically. Example graphs and the corresponding computer generated cut trees are illustrated. Also, an example is given where the cut tree information provides the optimal layout configuration.     

高效液相色谱-串联质谱法测定乳制品中的莫奈太尔及其代谢物

建立测定乳制品中莫奈太尔及其代谢物的高效液相色谱-串联质谱法。试样加水-饱和氯化钠-乙腈溶液提取,正己烷净化,经Inertsil C8（2.1 mm×100 mm,3 μm）色谱柱分离,以甲醇-0.5 mmol/L乙酸铵溶液为流动相进行梯度洗脱,采用电喷雾离子源串联质谱,在负离子扫描方式下以多反应监测模式检测,外标法定量。结果表明：莫奈太尔及其代谢物在0.1～5.0 μg/L范围内线性关系良好,定量限为2.0 μg/kg。在3 个加标水平下的平均回收率为79.5%～102.9%,相对标准偏差为2.0%～5.3%。该方法操作简便、快速、准确、灵敏度高、抗干扰能力强、回收率和重复性良好,适合于乳制品中莫奈太尔及其代谢物的测定。     

分光光度法同时测定油脂中氢过氧化物和醛含量

采用分光光度法同时测定油脂中氢过氧化物和醛含量,对有关参数进行了研究和优化。结果表明:N,N-二甲基对苯二胺为显色剂,乙酸为催化剂,40℃下反应40 min,用Kaiser法得出的最佳分析波长350、408 nm处可同时准确测定油脂中的氢过氧化物和丙二醛的含量;在120℃进行氧化,并对不同氧化程度的大豆油和鳄梨油中的氢过氧化物和丙二醛含量进行测定,测定结果与标准方法对比无显著性差异。