十二烷基－二甲基（2－羟基）乙基氯化铵系列季铵盐的缓蚀性能

通过失重法和极化曲线、线性极化两种电化学方法，研究了十二烷基二甲基（２－羟基）乙基氯化铵（１２２）、十四烷基二甲基（２－羟基）乙基氯化铵（１４２）和十六烷基二甲基（２－羟基）乙基氯化铵（１６２）对２０＃碳钢在５％盐酸中的缓蚀作用。并与新洁尔灭（十二烷基二甲基苄基溴化铵）进行了比较。结果表明，它们在酸性介质中具有很好的缓蚀作用。     

水/二甲基乙酰胺/聚砜体系双结点线的神经网络预测

基于实验数据,采用人工神经网络对水/二甲基乙酰胺/聚砜体系的双结点线进行了预测. 设计并验证了具有两个输入神经元(体系温度和聚砜的质量分数)和两个输出神经元(水和二甲基乙酰胺的质量分数)的BP(Back Propagation)网络, 选取50组训练样本和39组检验样本分别对网络进行了训练与检验. 结果表明,对水与二甲基乙酰胺质量分数的预测平均相对误差分别为1.86%和0.10%. 采用该网络能较好地预测常压下、20~60℃温度范围内水/二甲基乙酰胺/聚砜体系的双结点线.     

纳米-Al2O3颗粒对镍电结晶初期阶段的影响

利用循环伏安(CV)、计时安培(CA)和电化学阻抗(EIS)研究了纳米Al2O3颗粒在不同电位(vs.SCE)下对Ni自硫酸盐镀液在铜基体上电沉积的影响。结果表明,Ni-Al2O3体系共沉积的起始电位为:–740mV左右;在不同的电位下,纳米-Al2O3颗粒对镍沉积过程的影响有所差别;在电位–740～–830mV范围,与纯Ni沉积相比较,Ni-Al2O3体系沉积的峰电流所对应的孕育期tm明显缩短,反映Al2O3颗粒在阴极表面有利于镍沉积成核,且促进了电结晶成核。Al2O3颗粒吸附在阴极表面可能会阻碍部分离子电荷放电和物质传输过程,尤其在电位–250～–650mV范围,致使Ni-Al2O3体系沉积阻抗增加。在较高的过电位下,Al2O3颗粒的促进作用有所减弱,许多颗粒堆积在电极表面上还可能减小Ni-Al2O3沉积的还原反应电流。在电位–890mV,Ni-Al2O3体系电沉积初期阶段的成核过程基本遵循三维的Scharifker-Hill瞬时成核模式。     

基于函数控制的高精度可调压DC-DC电源

介绍了基于函数控制的高精度可调压DC-DC电源的设计原理,说明了用数值逼近方法导出控制函数的具体步骤:对通过单片机电路现场调试得到的测量数据进行曲线分段拟合,然后在Matlab仿真结果指导下对PWM脉冲的占空比动态范围进行调整,最终得到DC-DC电源的最优控制函数。实验表明,DC-DC电源使用该控制函数提高了对输出电压的控制精度。     

椭圆曲线离散对数的攻击现状

椭圆曲线密码的数学基础是基于椭圆曲线上的有理点构成的Abelian加法群构造的离散对数问题，讨论了椭圆曲线离散对数问题及其常用的理论攻击方法，分析了一些特殊曲线的攻击方法及最近的提出的一个新攻击方法-Weil Descent攻击（或GHS攻击），给出了椭圆曲线离散对数的实际攻击-软件攻击和硬件攻击现状。     

DIELECTRIC DRYING OF PARTICULATE MATERIALS IN A FLUIDIZED STATE

The experimental results of dielectric drying of capillary-porous material with negligible internal resistance to mass flow (alumina) and capillary-colloidal-porous material with significant internal resistance to mass flow (wheat) in a fluidized bed have been presented. The modified adiabatic saturati on equation for radiofrequency and microwave fluidized bed drying has been verified.     

Traffic violation detection based on the implicit curves family

We propose an effective algorithm for the detection of the traffic violation vehicle by employing a set of implicit function curves which can be used to describe the different regions on the roads. When the vehicles are detected to run across different road regions, we can determine in which region that vehicle lies easily and immediately by using the set of implicit functions. According to the vehicle trajectory and the relationship among different regions described by the implicit functions, we can quickly and accurately determine whether the vehicle violates the traffic rules. In order to improve the detection efficiency and accuracy greatly, we use the piecewise linear functions to approximate the set of implicit functions in actual detection. Experimental results show that our algorithm can detect the traffic violation and display the specific violated traffic rules in real time.     

考虑地震环境的设计常遇地震和罕遇地震的确定

本文在地震危险性特征分区图的基础上,通过对全国不同地震危险性特征区内的1905个城镇的危险性特征的分析,探讨了考虑地震环境的设计常遇地震和罕遇地震烈度、地震影响系数和地面最大加速度的合理取值,指出在抗震设计中考虑不同地区地震危险性差异的必要性,为更好地贯彻“小震不坏,中震可修,大震不倒”的抗震设计目标提供了新的依据。     

大型龙门机床的直线度误差建模及误差补偿

为减小大型龙门数控机床空间直线度误差,提高国产数控机床加工精度,提出基于B样条曲线的空间直线度误差模型及其补偿方法。使用激光干涉仪分别检测三轴龙门数控机床6个方向的直线度误差,应用B样条方法建立空间直线度误差数学模型.利用数控系统外部机械原点偏移功能,应用自主研发的误差实时补偿系统并依据基于B样条曲线的空间直线度误差数学模型,实现对大型龙门数控机床的空间直线度误差补偿.采用两轴联动补偿切削导轨面的方法进行试验,并与多项式模型和斜线插补模型进行对比,结果表明:B样条模型补偿后的导轨直线度最优,检测的导轨各方向直线度误差均减小90%以上,显著提高了大型龙门数控机床加工精度.     

Oil and the political economy of energy

The key issues concerning oil exploitation are still open for discussion: there is no agreement about where we presently stand in the world oil extraction curve, what is its exact shape, and how far can oil price grow before it changes irreversibly the world economy and consumer behavior. The paper proposes an alternative scenario to the Hubbert's bell-shaped model of oil exploitation, based on more realistic assumptions regarding political agendas in oil-exporting countries and consumer behavior dynamics in oil-importing countries. Under this scenario, the joint impact of markets and public policy in oil importing countries together with “resource pragmatism” policy in oil-exporting countries allows for a less steep oil supply curve with a much fatter tail compared to the Hubbert's model.