基于面心组合的排气歧管响应曲面优化设计

为解决发动机排气歧管结构优化通常采用单因素控制变量法或正交试验法带来的参数交互作用不显著等局限问题,采用中心复合试验设计(Central Composite Design)方法中的面心组合法构建响应曲面优化.以某重型载货汽车的发动机排气歧管为研究对象,实现了排气歧管38组结构参数的快速匹配,建立了多项式数学模型,得出了响应目标回归方程,拟合出了排气歧管最佳的结构参数及对应的流动均匀指数,并运用数值模拟方法对响应曲面优化的结果进行了验证.结果表明:当四支管组合排气时,基于面心组合试验设计下的排气歧管经过响应曲面方法优化出最优结构的流体流动均匀指数由原来的0.76提升到0.82,比初始结构升高了6个百分点.     

特种磷化液用于电厂蒸汽导气管室温磷化

研究了HH951特种磷化液用于大型电厂蒸汽导气管的室温磷化工艺，并用多种方法对磷化膜质量进行了评价，同时报道了该工艺在多家电厂300MW机组蒸汽导气管的应用。间歇式磷化工艺，能提高磷化膜的耐蚀能力，并大大减少了药品用量，HH951磷化效果优良，实际使用最低磷化温度4℃，完全能满足我国大多数地区的电厂蒸汽导气管清洗磷化的需要。     

Costate estimation for dynamic systems of the second order

The dynamics of a mechanical system in the Lagrange space yields a set of differential equations of the second order and involves much less variables and constraints than that described in the state space. This paper presents a so-called Legendre pseudo-spectral (PS) approach for directly estimating the costates of the Bolza problem of optimal control of a set of dynamic equations of the second order. Under a set of closure conditions, it is proved that the Karush-Kuhn-Tucker (KKT) multipliers satisfy the same conditions as those determined by collocating the costate equations of the second order. Hence, the KKT multipliers can be used to estimate the costates of the Bolza problem via a simple linear mapping. The proposed approach can be used to check the optimality of the direct solution for a trajectory optimization problem involving the dynamic equations of the second order and to remove any conversion of the dynamic system from the second order to the first order. The new approach is demonstrated via two classical benchmark problems. Supported by the National Natural Science Foundation of China (Grant Nos. 10372039, 10672073), and the Innovation Fund for Graduate Students of NUAA (Grant No. 4003-019016)     

无线电监测网络建设的新思考

近几十年来,乘着改革开放的春风,我国的经济持续高速发展,令世人瞩目.无线电业务和各类无线电台站随之快速增加,这使无线电频率需求增长,资源短缺,无线电干扰增多,电磁环境日趋恶化.就广东省而言,据不完全统计,至2005年底,全省除移动通信用户外的无线电台站总数近16万,公众移动电话基站和小灵通基站近10万座,电话用户超过1亿户,有2/3是移动用户,无线电业务已经渗入到人们日常生活的各个方面.这给无线电管理和无线电监测工作带来了机遇和挑战.     

基于角度不变的线阵推扫式CCD相机几何畸变在轨检校方法

对航天遥感相机进行在轨检校,是提高卫星产品质量,扩大产品应用效果的重要技术内容.文中研究了一种基于角度不变的线阵推扫式CCD相机几何畸变在轨检校方法.该方法利用相机外方元素对于相机视向量夹角角度影响比较小的原理,根据地面控制点和一级产品图像,求解相机视向量夹角,从中提取相机光学部件的畸变模型参数,从而实现相机内外方元素解耦.相机畸变模型采用一维3阶多项式,对焦距和主点等引起的低阶误差能够很好地吸收.该方法用在HJ-1A/B卫星的宽幅盖CCD相机几何畸变校正上,检校误差残留在2—6个像元,和参考数据精度相似,表明取得了很好的校正效果.     

Characterization of single-event multiple cell upsets in a custom SRAM in a 65 nm triple-well CMOS technology

In this paper, the characterization of single event multiple cell upsets(MCUs) in a custom SRAM is performed in a 65 nm triple-well CMOS technology, and O(linear energy transfer(LET) = 3.1 Me V cm2/mg), Ti(LET = 22.2 Me V cm2/mg) and Ge(LET = 37.4 Me V cm2/mg) particles are employed. The experimental results show that the percentage of MCU events in total upset events is 71.11%, 83.47% and 85.53% at O, Ti and Ge exposures. Moreover, due to the vertical well isolation layout, 100%(O), 100%(Ti) and 98.11%(Ge) MCU cluster just present at one or two adjacent columns, but there are still 4 cell upsets in one MCU cluster appearing on the same word wire. The characterization indicates that MCUs have become the main source of soft errors in SRAM, and even though combining the storage array interleaving distance(ID) scheme with the error detection and correction(EDAC) technique, the MCUs cannot be completely eliminated, new radiation hardened by design techniques still need to be further studied.     

水质蒸馏法检测氨氮方法的调整

针对实验室使用HJ535-2009中纳氏试剂分光光度法(蒸馏法)检测水质回收率不达标情况进行研究分析,实验人员发现由于PH值受硼酸缓冲体系的影响,导致反应不能正常进行,通过对PH值的调整,使回收率达到方法要求,从而提高了方法的准确性.     

杂粕型日粮中添加杂粕溢多酶对肥育猪生长、饲料转化率的影响

日粮中杂粕含量相同而杂粕溢多酶添加量不同时,肥育猪日增重和饲料转化率随着杂粕溢多酶添加量的增加而提高。在不同杂粕含量的日粮中添加相同量的杂粕溢多酶,杂粕含量少的日增重高,饲料转化率也高。在杂粕型日粮中添加杂粕溢多酶,能提高肥育猪的生长速度和饲料转化率。     

支承弹簧对输液曲管固有频率和极限流速的影响

基于Hamilton变分原理,导出具有弹性支撑的1/4圆形输液曲管的变分—积分方程。采用多个函数组合的方法,选取满足边界条件的试函数,利用Galerkin直接法求出系统的固有频率和极限流速的近似解析公式。数值结果表明,弹簧对固有频率和极限流速都有显著影响。根据数值结果,用最小二乘法给出固有频率和极限流速与弹簧刚度的关系公式。