桥台支座布置方式对连续梁桥地震反应的影响

为了避免桥台的地震破坏,提出一种新型桥台支座布置方式,通过双向滑动支座、弹塑性挡块和拉压连接装置的联合作用来工作.以2座连续梁桥为例,通过新型桥台支座布置方式和传统桥台支座布置方式的对比研究,分析了挡块屈服力、桥台约束刚度对桥梁横向地震反应的影响.结果表明:对于传统桥台支座布置方式,桥台承受的地震力随着地震强度的增大而增加,存在地震破坏风险;对于新型桥台支座布置方式,可以通过调节挡块横向屈服力来控制桥台地震力,既可使桥台分担一部分结构地震惯性力,又可避免桥台破坏.进行抗震设计时,可以根据具体的桥梁和对应的地震动输入,选择合适的桥台挡块横向屈服力,以使整座桥梁的地震反应达到最优状态.     

一种验证软件演化过程行为的代数推导方法

针对现有软件过程验证主要以结构验证和性质验证为主,缺乏行为验证的不足,提出了一种验证软件演化过程行为的代数方法.该方法使用通信进程代数ACP对软件演化过程元模型EPMM进行扩展,提出软件演化过程元模型代数EPMM-A.针对EPMM建模产生的软件演化过程模型,一方面使用EPMM-A形式定义软件演化过程模型的行为规约,另一方面在其公理系统的支持下,基于等式推导验证软件演化过程模型的行为与行为规约是否一致,使行为验证方式从模型推导(非形式化)变为代数推导(形式化).为了说明代数推导的正确性,证明了软件演化过程元模型代数的公理系统具有可靠性.     

生物光子与神经信号传递和处理

指出了针对神经信号传递和处理的主流理论的争论,即神经信号以电信号和化学信号的形式进行传递处理的理论虽然可以很好地解释感觉、运动、反射等神经系统的低级功能,但很难构建出解释大脑高级功能和精神活动的一般概念或原则.提出了神经回路中存在有生物光子(又称生物超弱发光)传递,并可能介导神经信号的传递和处理、参与人脑的高级功能和精神活动.综述了生物光子在神经回路中传递及介导神经信号传递处理的相关理论假说和实验研究.     

Surface wetting processing on BNNT films by selective plasma modes

The wettability of boron nitride nanotube (BNNT) films was modified using a combination of pulsed and continuous wave (CW) mode plasma. The combined mode effectively modified the wettability of BNNT films and kept the nanostructures intact. The BNNT films changed from superhydrophobic to superhydrophilic after combined mode treatment at 600 W min. In contrast, the contact angle controllable decreased linearly in a controllable way with increasing energy input before eventually becoming superhydrophilic after 1000 W min of CW mode treatment. A high concentration of graft functional groups formed, along with point defects. More point defects formed when using combined modes and higher energy input. Mainly amine functional groups were grafted by combined mode plasma, while the CW mode plasma led to more formation of amide and imine on the BNNTs. Research into controllable wettability and selection of grafted functional groups should enable promising applications of BNNTs in composites and biology in the future.     

Analysis of variation trends and causes of aerosol optical depth in Shaanxi Province using MODIS data

The temporal and spatial variations and causes of aerosol optical depth （AOD） in Shaanxi Province were investigated based on the Moderate Resolution Imaging Spectroradiometer （MODIS） derived aerosol data for the period of March 2000-February 2012. The results showed that the distribution of aerosol was largely affected by topography and local economic activities. Heavy aero- sol loading and increasing tendency in AOD was observed in Guanzhong, Hanzhong and Ankang basin, while a reverse tendency was revealed in most other regions. The spatial distribution of aerosol Angstrom wavelength exponent was predominantly related to vegetation coverage in Shaanxi. Airborne dust from ground is an important source of coarse mode aerosols. Vegetation im- provement indicated by an increase in normalized difference vegetation index （NDVI） and a reduction in dust weather led to a gradual decrease in coarse mode AOD to the north of Qinling Mountains in Shaanxi, while anthropogenic activities led to an in- crease in fine mode AOD in other areas except those covered by forests. The main aerosol type gradually shifted to the urban industrial type in Shaanxi.     

Combining sum-difference and auxiliary beams for adaptive monopulse in jamming

Only in the presence of sidelobe jamming(SLJ),can the conventional adaptive monopulse technique null the jamming effectively and maintain the monopulse angle estimation accuracy simultaneously.While mainlobe jamming(MLJ) exists,the mainlobe of adaptive pattern will subject to serious distortion,which results in a failure of detecting and tracking targets by monopulse technique.Therefore,a monopulse angle estimation algorithm based on combining sum-difference beam and auxiliary beam is presented.This algorithm utilizes both high gain difference beams and high gain auxiliary beams for cancelling the mainlobe jammer and multiple sidelobe jammers(SLJs) while keeping an adaptive monopulse ratio.Theoretical analysis and simulation results indicate that the serious invalidation of monopulse technique in MLJ and SLJs scenarios is resolved well,which improves the monopulse angle accuracy greatly.Furthermore,the proposed algorithm is of simple implementation and low computational complexity.     

制冷设备冷凝压力及冷凝温度的节能控制研究

随着制冷空调技术应用的日益广泛,制冷空调装置的能耗也在迅速增长,因此,研究制冷空调的节能具有重大的现实意义。通过介绍制冷设备的原理,对冷凝器的节能技术进行了分析,提出几种控制冷凝压力来实现节能的调节方法。     

Positronium annihilation in oxygen and nitrogen mixture

Formed in silica aerogels, positronium annihilation in oxygen and nitrogen mixture is studied by a simple and convenient method. The results show that ortho-positronium (o-Ps) lifetime is significantly shortened when some oxygen is introduced into nitrogen gas and that the o-Ps collisional quenching rate for an oxygen molecule is (28.0±0.4) μs^?1·amagat^?1 (1 amagat = 2.69×10²⁵ m^?3). It is found that the o-Ps annihilation rate in oxygen of 1atm at room temperature is (25.5±0.5) μs^?1 and that the effective number of electrons per oxygen molecule available for 2γ annihilation of positron in the o-Ps is (34.6±0.4).     

抗滑桩加固边坡中桩要素设计的三维有限元分析

抗滑桩加固边坡是工程中常用的方法,其中桩位、桩间距、桩径、桩长等桩要素是抗滑桩设计的重要问题,它直接关系到边坡工程的造价与安全．通过典型的边坡实例,利用考虑桩一土相互作用的有限元折减程序,探讨计算模型尺寸、桩要素对边坡安全系数的影响．分析可知,计算模型尺寸对边坡安全系数影响很小,模型尺寸为O．5s时计算效率最高;边坡安全系数随桩位近似呈二次抛物线分布,抗滑桩布置于边坡中部既能获得最大的安全系数又能充分发挥材料的抗滑作用,为最佳桩位布置点．边坡的安全系数随桩间距的增大而减小,随桩径、桩长增大近似呈线性增加,桩间距增大桩间土拱作用逐渐减弱,最后趋近于无桩状态．桩长设计中,桩的锚固深度宜为桩长的1／3—1,2．     

高效液相色谱法分析聚甘油乳酸酯的组成

建立了HPLC-ELSD法测定聚甘油乳酸酯组成的方法.采用Agilent DZORBAX NH2色谱柱（4．6 mm×250 mm）,确定了最佳色谱条件：流动相为乙腈和水（体积比为90∶10）,蒸发光散射检测器（ELSD）,流速为1．2 mL/min,柱温40℃,进样量4μL .结果表明,在0．1～0．5 mg/mL范围内线性关系良好,相关系数为0．9986,在信噪比（S/N）为3时,检出限为0．020 mg/mL .回收率为98％～102％,相对标准偏差（RSD）为1．2％～1．4％.