Liquid Marble Patchwork on Super-Repellent Surface

Liquid marble (LM) is a droplet that is wrapped by hydrophobic solid particles, which behave as a non-wetting soft solid. Based on these properties, LM can be applied in fluidics and soft device applications. A wide variety of functional particles have been synthesized to form functional LMs. However, the formation of multifunctional LMs by integrating several types of functional particles is challenging. Here, a general strategy for the flexible patterning of functional particles on droplet surfaces in a patchwork-like design is reported. It is shown that LMs can switch their macroscopic behavior between a stable and active state on super-repellent surfaces in situ by jamming/unjamming the surface particles. Active LMs hydrostatically coalesce to form a self-sorted particle pattern on the droplet surface. With the support of LM handling robotics, on-demand cyclic activation–manipulation–coalescence–stabilization protocols by LMs with different sizes and particle types result in the reliable design of multi-faced LMs. Based on this concept, a single bi-functional LM is designed from two mono-functional LMs as an advanced droplet carrier.     

Using electroencephalogram to continuously discriminate feelings of personal thermal comfort between uncomfortably hot and comfortable environments

Thermal comfort is an important factor for the design of buildings. Although it has been well recognized that many physiological parameters are linked to the state of thermal comfort or discomfort of humans, how to use physiological signal to judge the state of thermal comfort has not been well studied. In this paper, the feasibility of continuously determining feelings of personal thermal comfort was discussed by using electroencephalogram (EEG) signals in private space. In the study, 22 subjects were exposed to thermally comfortable and uncomfortably hot environments, and their EEG signals were recorded. Spectral power features of the EEG signals were extracted, and an ensemble learning method using linear discriminant analysis or support vector machine as a sub-classifier was used to build the discriminant model. The results show that an average discriminate accuracy of 87.9% can be obtained within a detection window of 60 seconds. This study indicates that it is feasible to distinguish whether a person feels comfortable or too hot in their private space by multi-channel EEG signals without interruption and suggests possibility for further applications in neuroergonomics.     

低觉醒脑电识别与唤醒的可穿戴系统研究

为智能化地识别警戒作业人员出现的低觉醒、注意力下降的生理状态，本文介绍了一种基于FPGA和脑电信号处理的低觉醒状态检测与唤醒系统，系统通过传感器从大脑头皮采集脑电信号，转换为数字信号，经傅里叶变换获取了脑电信号的θ相对能量、α相对能量、重心频率、谱熵等4个特征量，由4个特征量表征低觉醒状态并运用支持向量机对低警戒状态进行识别，当识别出低觉醒状态时采用声音报警模块发出声音，唤醒警戒作业人员。设计系统能够较好地识别出低觉醒状态，识别率达90.8%，可为提高警戒作业工作绩效提供一种可穿戴的智能装备。     

掘进巷道快速过断层施工技术应用

基于四候煤矿3108回风顺槽过F3断层期间,顶板出现严重破碎、下沉现象,提出了俯斜台阶法施工工艺,并对断层破碎带顶板采取MF-2型化学材料注浆加固以及"钢筋锚索网+U29梯形棚"联合支护措施。支护效果检验结果表明,联合支护有效控制了断层破碎区顶板下沉、破碎现象,保证了巷道顶板稳定性。     

面源红外诱饵对抗红外制导导弹干扰策略研究

面源红外诱饵使用的过程中,合理有效的干扰策略是干扰红外制导导弹的关键,针对这一问题,通过理论分析与仿真模拟相结合得到面源红外诱饵对抗红外制导导弹的干扰策略。首先以红外成像制导导弹为例,介绍红外制导导弹的仿真模型,然后将攻击过程分为锁定前与锁定后,以命中率为评价指标,得到两个阶段下的最佳干扰策略,包括诱饵的最佳释放时机、释放间隔以及载机应采取的机动动作等。     

聚烯烃催化剂硅胶载体的制备和表征

采用并流共沉淀法制备了适用于聚烯烃催化剂的硅胶载体,为减少颗粒的聚集,在制备过程中添加一种表面活性剂。利用透射电子显微镜(TEM)、比表面积测定(BET)和X射线粉末衍射(XRD)法对制备的硅胶载体进行了表征;考察了在制备硅胶载体过程中原料硅酸钠溶液的浓度、溶液pH以及焙烧温度对产物硅胶载体的物理性能的影响。实验结果表明,硅酸钠溶液的浓度影响硅胶的初始粒子的大小,溶液pH直接影响硅酸钠的水解速率,焙烧温度影响硅胶的孔结构和比表面积。当硅酸钠溶液的浓度为0．2mol／L、溶液pH为8-9、反应温度为70℃、焙烧温度为700℃时,硅胶载体的BET比表面积为242．22m2／g、最可几孔径为16．45 nm、堆密度为0．492 1g/mL,与进口硅胶(Silica Gel 955)的物理性能相近。     

Understanding silica-supported metal catalysts: Pd/silica as a case study

Supported metal catalysts, particularly noble metals supported on SiO₂, have attracted considerable attention due to the importance of the silica–metal interface in heterogeneous catalysis and in electronic device fabrication. Several important issues, e.g., the stability of the metal–oxide interface at working temperatures and pressures, are not well-understood. In this review, the present status of our understanding of the metal–silica interface is reviewed. Recent results of model studies in our laboratories on Pd/SiO₂/Mo(1 1 2) using LEED, AES and STM are reported. In this work, epitaxial, ultrathin, well-ordered SiO₂ films were grown on a Mo(1 1 2) substrate to circumvent complications that frequently arise from the silica–silicon interface present in silica thin films grown on silicon.     

负载型复合载体及其镍基催化剂的性能

采用溶胶-凝胶法制备了负载型ZrO_2/Al_2O_3和ZrO_2/Al_2O_3-SiO_2复合载体,研究了不同复合载体对Ni基催化剂CO_2重整甲烷反应和性能的影响,并用XRD、IR、TPR、TPD和BET等方法对复合载体及催化剂进行了表征。结果表明,ZrO_2负载在基载体后比表面积、碱性、活性组分Ni的分散度和Ni与ZrO_2的相互作用增大。NiO在复合载体表面的分散容量与ZrO_2的负载量有关,ZrO_2的负载量为37．5%时NiO的分散容量达最高值(24．0%)。与Ni/ZrO_2相比,Ni/ZrO_2/Al_2O_3-SiO_2和Ni/ZrO_2/Al_2O_3催化剂对CO_2的吸附能力增大,CO_2吸附量增加,酸强度降低,CO_2重整CH_4反应活性提高,其中以Ni/ZrO_2/Al_2O_3催化剂的活性最好。     

有线电视系统干扰信号的产生及排除

通过对有线电视系统干扰信号产生原因的理论分析，提出在实际操作中的解决方案，以期达到使有线电视系统信号的输出更稳定、电视画面更清晰的目的。     

基于支持向量机的多类分类研究

现今流行的分类方法的重要基础是传统的统计学，前提是要有足够的样本，当样本数目有限时容易出现过学习的问题，导致分类效果不理想。引入支持向量机方法，它基于统计学习理论，采用了结构风险最小化原则代替经验风险最小化原则，较好的解决了小样本学习的问题；又由于采用了核函数思想，把非线性空间的问题转换到线性空间，降低了算法的复杂度。对其相关内容包括优化算法及多类分类问题的解决进行了研究，最后用一个实例说明了该方法的可行性和有效性。