孔径

Alon g with testing press increased step by step, more small pore size were opened, t hats to say, the pore number which liquid could permeate were increasing, accor dingly permeable liquid flux was increasing.

随着所施加的测试压力逐步增加，更小孔径的膜孔道被打开，即液体可透过的膜孔道数目逐步增多，透过膜的液体流量也相应增加。

The light filtrating properties were studied through the filling of 3D continuous pores with divinyl benzene as a highly refractive liquid.

研究了三维连续孔道在充满二乙烯基苯高折射液体后的滤光特性，通过引入金属离子改变固体材料折射率的方法，验证了光在高折射液相中的全反射效应，并从定性角度建立三维骨架材料的孔径及分布与透射光波长范围之间的关系，对新光学现象给出了初步解释。

Relation and Application of Density and Compression Strengh of Effervescible Polystyrence Foam Material;2. On the basis of discussing principle of foam material cell shape,this research studied two methods to measure cell diameter and its distribution,which are picture process and fractal dimension.

探讨了泡沫材料泡孔结构形成原理及泡沫材料孔径与分布测量途径，并实际运用图像处理和分维二种创新的测量方法对泡孔进行测量分析，其二结果相当一致，从而证实了图像法与分维法的可行性，同时说明了分维的科学性。

By time-varying filtering, we realize the signal selectivity and interference suppression, especially for the signals with time-varying power spectrum. It is shown herein that conventional eigenstructure based methods are lower dimensional special case of the time-frequency subspace fitting method. The closed-form array response estimation algorithms for blind source separation in wireless communication is also developed in the dissertation by exploiting the data structure of second-order statistics of the array output in the presence of multipath. The proposed method achieves array response estimation with little constraint on signal property and propagation environment such as scatters or angular spread. Moreover, the array utilized here can be of arbitrary geometry and even uncalibrated. Since the closed-form solution is obtained, no misconvergency may occur and large amount of computation can be saved. The equivalent feed model and corresponding optimization designation are proposed to realize the downlink multi-user selective transmission. By coherent and non-coherent superposition of the electromagnetical field, multiple beams can be formed using a single array, so that each co-channel user signal is transmitted in each beam and will not interfered with each other. The proposed system scheme implements the digital beamforming and the channel allocation in the base band, therefore is suitable for the utilization of the radio software technology. The feasibility and effectiveness of the proposed model are proved by the RF experiment.

在窄带条件下，GSC－SSF方法还可以提高阵列的虚拟孔径，从而提高估计的性能；可以证明，Cyclic DOA 和SC-SSF方法可看作该方法的特例或近似； 3、提出了二维GSC－SSF方法和宽带谱相关DOA矩阵方法，利用信号的循环平稳特性解决了宽带条件下二维 DOA 估计问题，并具有阵元数少、计算量较小的特点； 4、提出了时频子空间拟合和宽带时频DOA估计算法，将联合时频分析的理论和方法引入到阵列信号的空间谱估计研究中，利用时变滤波实现信号选择性测向和干扰抑制，特别适合于谱时变信号；可以证明传统特征结构法可看作是时频子空间拟合方法的特例； 5、提出了多用户环境下阵列响应的估计方法——CARE方法，该方法对信号结构和传播参数（主要是散射源分布与角度散布）的约束较少，适用于各种几何结构的阵列甚至未校准的阵列，能够直接得到阵列响应的闭式解，因此计算量小、稳健性好，不存在收敛问题； 6、提出了针对多用户下行选择性发送的阵列等效激励模型、优化设计方法及其系统实现方案，通过空间场的相干叠加与非相干叠加使得单一阵列能够形成多个波束，并保证各波束内的用户信号各不相同且相互干扰最小；其系统方案具有在基带实现数字波束成形、信道分配并便于软件无线电实现的特点，其有效性已得到外场实测数据的证实。

The factors include the material, the structure, the refractive index distributing, the length, the diameter, the num erical aperture,thermal effect and the coupling of optical fiber.

这些因素主要包括光纤材料、构造、光纤的折射率分布、光纤的长度和芯径、光纤的数值孔径和热效应以及耦合等。

In view of the facts that traditional graphical construction has less pertinence to stray light and tracing different incidence angle rays is fatiguesome and more likely to omit some rays, we proposed a reverse ray-trace method based on the ray reversibility. According to the method, a dot-matrix source was set at the image plane. Each dot emitted rays to fully cover the system aperture. A detector surface, large enough to receive all possible rays from the source, was set at object plane.

针对传统作图法设计遮光罩的针对性不强，且追迹不同入射角的光线繁琐、容易遗漏的问题，本文提出一种逆向追迹法，依据光的可逆性，在像面处设置点阵面光源，每一点都发出充满系统孔径的光束，在物面设置足够大的探测面，使之有充足的余量记录所有到达物方的光线，利用该方法可以在探测面上直观地区分出非成像杂散光。

This method is featured with high estimating performance and little computation burden by n o aperture losing and temporal smoothing. The reˉ quirements on hardware for RSDOA matrix method is predigested consu medly only need one fiducially sensor array with arbitrary structure and a single scattered sensor cell, so it is more effective and practical than other existing similar algoˉ rithms.

与现有算法相比较，RSDOA方法对于系统的硬件需求大为下降，计算负担小；由于无阵列孔径损失问题且空时协方差矢量具有时域平滑效果，因此参数估计性能优越，具有广泛的适用性与实际的应用价值。

The porosity,max pore size and mechanical performance of the membrane were also characterized and it was foun...

并且对膜的孔隙率、最大孔径、力学性能和截留率进行了表征。

MPPs are typically made of a thin metal or plastic panel. However, thin limp panels are generall not suitable as an interiornish of room walls because they do not have sucient strength, which prevent spractica lapplication of MPPs as an interiornish of roomwalls.

典型的微穿孔板为孔径与板厚均小于1mm的金属或塑料板，这些极薄的板材因其强度低，通常不适用于民用，也因此使微穿孔板这一良好的吸声共振结构的应用范围受到局限。

An image formation scheme for airborne synthetic aperture radar based on field programmable gode arrays is designed.

提出一种基于现场可编程门阵列实现机载合成孔径雷达实时运动补偿和成像的设计方案。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。