PZT／Terfenol-D／PVDF层状复合磁电材料谐振特性

采用热压法制备出二层锆钛酸铅(PZT)／聚偏氟乙烯(PVDF)与1层Tb0.28Dy0.72Fe2(Terfenol-D)／PVDF叠层结构的三元复合磁电材料，研究了不同PVDF含量，以及不同层厚比tp／L对样品的介电常数、介电损耗、电阻率、谐振频率以及磁电转换系数αE33，αE31的影响规律，结果显示PVDF的含量和层厚比都存在最佳值(最佳值出现在产0．5，tp／L=2／7)，并且在这个最佳值处，磁电转换系数达到最大。     

双包络TI-环面蜗杆传动的二次包络分析

在一次包络分析的基础上,着重进行了二次包络齿面接触分析,推导出了蜗杆和蜗轮齿面方程。齿面接触分析表明：齿面呈双线接触,润滑条件好,承载能力大,在重型机械传动装置中具有实用价值。     

Si及变质处理对Mg2Si/Mg复合材料的影响

分析了Mg-Si二元合金直接原位形成Mg2Si/Mg复合材料的过程,研究了Si含量以及变质处理对复合材料组织和性能的影响。试验结果表明,随着合金中Si含量的增加,合金的流动性降低,复合材料中原位Mg2Si的数量增多,树枝晶形态更为发达;对优化的Mg-8Si合金,进行混合稀土(MM)和Sb变质处理,可明显改善Mg2Si的形态和分布,但Sb变质的效果要好于MM。合金经质量分数为1.2%的Sb变质处理后,Mg2Si以颗粒状均匀分布在Mg基体中,从而使复合材料具有较好的耐磨性。     

大液相负荷下斜孔塔板的流体力学性能

针对大液相负荷气液传质操作 ,通过冷模实验 ,重新确定了普通斜孔塔板的液体力学性能 ,并给出了新的关联式。同时基于普通正排斜孔塔板在大液量操作条件下压降大 ,泄漏和雾沫夹带严重等缺点 ,沿用梯形导向浮阀的思想 ,提出了变正排为斜排的改进方案 ,并在相同条件下对两者的液体力学性能进行初步比较。证明了斜排斜孔塔板是一种适合大液体处理量且操作弹性较宽的塔板     

Simulation of Nonstationary Spring Discharge Using Time Series Models

We present a detailed analysis and comparison of two time series models, i.e., ARIMA and ARIMA-GARCH, to simulate the discharge of a karst spring (Niangziguan Springs (NS) complex) in the northern China. Statistical tests for the residuals are applied to examine the reasonability of the models. Statistically, both models are reasonably good to simulate the mean value of the discharge of the NS complex. The statistical test shows that the residual discharge data have conditional time-varying variance and volatility clustering, known as heteroscedasticity of the data. Calibration test shows that the ARIMA-GARCH model gives a varying confidence interval, which can more effectively capture the heteroscedasticity of the data, comparing with a constant confidence interval in the ARIMA model. In the validation and application process, we applied two approaches to simulate the discharge data: (1) fixed models, and (2) evolving models. The confidence interval width monotonically increases in both fixed models, and the fixed ARIMA-GARCH model has faster increasing confidence interval width than the fixed ARIMA model. This suggests that the fixed time series models are only suitable for short-term prediction. However, we found that this drawback can be compensated by updating the model once new data become available. Our evolving models show more reasonable confidence interval width for both models. In addition, the application shows that the ARIMA-GARCH model is very sensitive to the data fluctuation. We also found the evolving ARIMA-GARCH model was able to return to the narrow confidence interval width once the fluctuation diminished. Hence, we conclude that the ARIMA-GARCH model is more suitable for the sequences with strong heteroscedasticity.     

PEN/PTT共混聚酯的熔融行为

利用差示扫描量热仪对不同配比的聚萘二甲酸乙二醇酯/聚对苯二甲酸丙二醇酯(PEN/PTT)共混体系的熔融行为进行了分析,发现在共混体系中两组分形成各自的晶体,PEN和PTT的熔点均随另一组分含量的增加而下降。根据Nishi-Wang方程,按300℃计算,由PEN/PTT共混体系中PEN熔点下降计算所得到的相互作用能密度为-0．214 2 J/cm~3,相互作用参数为-0．006 8,表明PEN/PTY共混体系在熔融态是热力学性质稳定的相容体系。     

Racking focus and tracking focus on live video streams: a stereo solution

The ability to produce dynamic Depth of Field effects in live video streams was until recently a quality unique to movie cameras. In this paper, we present a computational camera solution coupled with real-time GPU processing to produce runtime dynamic Depth of Field effects. We first construct a hybrid-resolution stereo camera with a high-res/low-res camera pair. We recover a low-res disparity map of the scene using GPU-based Belief Propagation, and subsequently upsample it via fast Cross/Joint Bilateral Upsampling. With the recovered high-resolution disparity map, we warp the high-resolution video stream to nearby viewpoints to synthesize a light field toward the scene. We exploit parallel processing and atomic operations on the GPU to resolve visibility when multiple pixels warp to the same image location. Finally, we generate racking focus and tracking focus effects from the synthesized light field rendering. All processing stages are mapped onto NVIDIA’s CUDA architecture. Our system can produce racking and tracking focus effects for the resolution of 640×480 at 15 fps.     

分子生物技术在石油降解微生物研究中的应用

总结了生物法治理石油污染的局限性,介绍了几种在石油降解微生物研究中广泛应用的分子生物技术,并对该研究领域未来的发展趋势进行了预测。     

双电层电容器用沥青焦基活性炭的制备工艺条件对其孔结构及电化学性能的影响

以沥青焦为原料，KOH为活化剂在不同的工艺条件下制备了双层电容器用活性炭电极材料。分别考察了活化剂用量、活化时间、以及加入Cu、Ni催化活化等工艺条件对活性炭孔结构及作为双电层电容器电极的电化学性能的影响。结果表明：在实验范围内增加KOH用量及活化时间，活性炭的比表面积和比电容增加，比电容最高达到247F／g。添加Cu、Ni催化活化后活性炭的比表面积及比电容增加，高功率放电性能明显改善。     

元明青花红绿彩的研究与考证

青花红绿彩作为加彩器的一种,比传统的观点早一个朝代,根据明中青花红绿彩盖罐结合最新的窑址考古成果,得出元代的窑炉设计和釉面配方的缺陷,使元代青花红绿彩的生产和存世极少,明官窑中由于斗彩的出现,青花红绿彩在民间一直沿烧。与元代风格相近,只是到了后期风格才大变。