Transmission of dynamic biochemical signals in the shallow microfluidic channel: nonlinear modulation of the pulsatile flow

A controlled quantitative loading of dynamic biochemical signals on cells in vitro is essential for cell dynamic analysis. Microfluidics provides the potential for reproducing and controlling spatio-temporal biochemical signals through the various microfluidic channels. Herein we investigate the transmission characteristics of dynamic biochemical signals in pulsatile flows by analytically solving the convection–diffusion equation for the time-dependent Taylor–Aris dispersion with perturbation method. We prove that the transmission of dynamic biochemical signals in pulsatile flows is subject to the two correlate effects: low-pass filtering and nonlinear amplitude–frequency modulation. These two effects are systematically characterized and the influence factors are studied, including the biochemical signal frequency, the pulsatile flow frequency, the transmission distance and the average pulsatile flow rate. We concluded that the balance of multiple factors should be taken into account for better loading biochemical signals on cells cultured in the microfluidic channel.     

高盐分餐厨垃圾湿式单级厌氧消化的试验研究

对高盐分餐厨垃圾湿式厌氧发酵进行了研究,试验结果表明:发酵液盐分浓度不断累积,由最初的0.084%增长至0.69%,并且还在继续增加;进料有机负荷控制在3 kgVS/(m3·d)时,反应器运行良好,发酵液COD稳定在2 620 mg/L左右,VFA浓度保持在880 mg/L以下,产气量81 L/d,甲烷含量60%左右.     

一种低频外露机载天线隐身设计

针对低成本准隐身飞机,探讨了一种低频外露机载天线的隐身设计,提出了一系列的隐身设计措施(例如优化天线外形、改变安装方式、在天线罩表面涂敷吸波材料等);经过隐身仿真、隐身测试等手段,获取了天线在不同频点、不同极化下的RCS均值,并通过仿真、测试数据对比,验证了隐身改进设计的有效性,并为其他外露物隐身设计提供了设计依据和手段.     

结构在水平与竖向地震同时作用的非平稳响应

本文对单自由度结构在水平与竖向地震同时作用下的随机地震响应问题进行了系统研究。首先用简明的推导方法,建立了结构参激随机振动方程;其次利用Stratonovich随机微分方程、It随机微分方程、FokkerPlanck方程和矩微分方程的相互转换关系,用统一的公式法,建立了结构响应矩方程;然后根据Hurwitz随机稳定准则,获得了结构一阶和二阶响应矩渐近稳定条件的解析判断式;最后针对非平稳水平地震激励的最典型四种强度包络函数,综合应用复模态法,获得了结构非平稳响应二阶矩的解析解,给出了算例,并综合分析了各种参数对结构响应和稳定性的影响。     

受弯构件纵向受力钢筋最小配筋百分率质疑与改进建议

分析了现行混凝土结构设计规范中对纵向受力钢筋所作最小配筋百分率ρｍｉｎ规定和相应设计计算方法的不足，建议用截面最小纵向受力钢筋面积Ａｓｍｉｎ取而代之，并提出相就的设计计算方法供参考。     

Estimating Displacement of Periodic Motion With Inertial Sensors

Inertial sensors, like accelerometers and gyroscopes, are rarely used by themselves to measure displacement. Accuracy of inertial sensors is greatly handicapped by the notorious integration drift, which arises due to numerical integration of the sensors zero bias error. A solution is proposed in this paper to provide drift free estimation of displacement from inertial sensors.     

Study of incident angle dependence for dual-band double negative-index material using elliptical nanohole arrays

This work demonstrates the angular dependence of dual-band negative-index materials implemented by elliptical nanohole arrays (ENAs) consisting of an Al2O3 dielectric layer between two Au films. This article, it is believed for the first time, analyzes the scattering coefficients and displacement current of the ENA at different angles of plane-wave incidence to show that the ENA is double negative (showing both a negative effective permeability μ(eff) and a negative effective permittivity ε(eff) at multiple wavelengths (1095 and 1680 nm) for p polarization over a broad range of incident angles.     

The role of functionalized carbon nanotubes in a PA6/LCP blend

Multi-walled carbon nanotubes (MWCNTs) were carboxyl-functionalized in order to improve their dispersion in a polymer matrix. The carboxyl-functionalized MWCNTs (i.e., MWCNT-COOH) were added into a blend matrix consisting of polyamide 6 (PA6) and liquid crystalline polymer (LCP) (PA6:LCP = 80:20 in weight) to make ternary composites. The effects of MWCNT-COOH on the rheological, physical, morphological, thermal, mechanical, and electrical properties of the ternary composites have been examined systematically. The dispersion of MWCNTs in the polymer matrix and their interactions with the polymers (i.e., PA6 and LCP) were found to be the most important factors affecting all properties. The functionalization of MWCNTs resulted in the significant improvement in their dispersion in the polymer matrix and largely enhanced the interactions of MWCNTs with the polymer matrix. The functionalized MWCNTs acted not only as reinforcement fillers but also as a compatibilizer that could enhance the interfacial adhesion between PA6 and LCP. Interestingly, the packing density of the polymer matrix was greatly increased by adding MWCNT-COOH.     

地毯的抗静电性能与工艺设计

利用导电纤维等抗静电材料,以不同质量分数和不同方法加入地毯,探讨地毯的电阻与静电压的关系。     

FROM DATABASE TO OPERATION DESIGN USING A MULTIPLE MODEL APPROACH

We address the problem of estimating the input conditions (mixture compositions, operating temperature, pressure, etc.) that will result in manufacturing a product with the required properties using a data-based approach. A single-model type paradigm is shown to be unsuitable for all data sets or even for all output variables in a particular data set. A multiple-model type paradigm is therefore advocated. The input-output map is first obtained using one or more of the several modeling approaches. These models are then inverted to suggest operational strategies that will meet production goals. Several examples are presented to demonstrate the efficacy of the proposed methodology.