浅谈疫苗生产洁净室高效过滤器的良好运维及确认

高效过滤器对于维护疫苗生产车间的生产环境具有重要意义，结合法规与实际应用，对洁净室高效过滤器的运行与维护，及高效过滤器泄漏率测试进行讨论与思考。     

用大气尘计径计数效率测试通风过滤器的研究

通过对国内外计径计数法的比较，根据国外一般通风用过滤器的测试方法结合我国的实际情况对中国现行过滤器测试规范国标GBl2218—89提出一些新的建议。我国采用大气尘计径计数法测试过滤器的初始效率，该效率并不能真实反映过滤器的真实状况。为了更好的把握评价过滤器的真实使用情况，应该采用发尘量的加权平均效率进行评价。     

高效过滤器安装及洁净室面积对洁净度的影响

通过总结工程经验，讨论高效过滤器在安装时应着重注意的问题；通过对洁净室测试数据的分析，探讨了洁净室面积以及其他因素对洁净度的影响。     

洁净室施工安装中要注意的几个问题

分析了洁净室施工的特点,对目前洁净室的规范、材料、施工顺序等进行了介绍,强调洁净风管的制作、搬运、安装及高效过滤器安装是确保洁净度的关键,提出了洁净室施工安装中需要注意的几个问题。     

为控制粒子污染所需风量的计算

本文介绍了ISO6-9组（0.5μm）洁净室为控制粒子污染所需风量的计算。计算的同时，须注意合适的过滤器总效率值。为计算方便起见，还编制了一些计算用表。     

高效过滤器过滤效果数值模拟

主要介绍过滤器的过滤机理,并通过数值模拟分析这些过滤机理对微小粒子在过滤器上沉积速率的影响以及在工作台上沉积速率的影响,认为目前的过滤器过滤效率基本可以满足工业洁净室的需求。     

关于过滤器使用的一些技术探讨

对中国计量科学研究院（NIM）某实验基地在洁净室建设和运行过程中过滤器的使用方面进行了一些技术探讨，根据实际经验和看法对过滤器的性能和效率、使用寿命及其评判标准进行了技术总结，并提出选择滤料面积大的过滤器和一次性初效过滤器是性价比较高的技术方案。     

洁净室性能测试及认证的基础

<正> 由于当今芯片的线宽日趋细小,其设计和加工的工艺要求日益复杂,因此设计和建造相应的超净洁净室的价格也就变的非常昂贵,所以洁净室性能的测试就变的日益重要。在下面这篇文章中,新加坡CESSTECH公司突出了洁净室性能测试的重要性,并着眼于动态测试、测试标准和一些被推荐的惯例。     

最易穿透粒径在高效超高效过滤器测试中的应用

本文介绍了什么是最易穿透粒径及其产生原因，并且介绍了高效过滤器和超高效过滤器的滤纸效率的测试，过滤器的渗漏测试，过滤器的全效率测试的测试过程及最易穿透粒径在各项测试中的应用。     

预浓缩气相色谱质谱在半导体洁净室VOC管控中的应用

对预浓缩气相色谱质谱在半导体洁净室VOC（Volatile Organic compound,挥发性有机化合物）管控中的应用进行了系统的归纳和总结。主要从三个方面的应用进行了讨论：一是洁净室VOC来源确认,二是确认厂务系统处理效率的应用,三是厂务系统处理最终效果的确认。也是实验室分析仪器在半导体行业应用方面的成功范例。     

最佳小波调制

小波分析的理论正在逐步走向通信领域,小波调制因其频谱利用率的优势而受到重视。以往研究较多的是Daubechies和Battle-Lemarie小波系列,本文从频谱利用率的角度出发,讨论如何设计用FIR滤波器实现的最佳正交小波和尺度函数,给出了设计方法和结果。通过比较我们得出这样的结论:经过最优化设计,在同样的实现复杂性条件下,小波调制的频谱利用率有了明显的提高,因而可以用较简单的FIR滤波器获得较好的频谱性能。     

新型高准确度分光光度计的设计与测试

目前,干涉滤光片已广泛运用到辐射度学测量、光度学测量等领域,为保证其光谱透过率测量的高准确度,提出了采用基于DK242单色仪,入射、出射光路独立设计的全自动,单光路分光光度计,其测量部分采用了硅探测器与积分球组合的探测单元,提高了测量的准确度。装置的不确定度源包括波长定标、探测器均匀性、系统稳定性、光束移位等,装置整体不确定度达到8.78×10^-3,满足设计要求。     

Use of phase diversity and modified phase congruence for edge enhancement in ultrasonic imaging

Enhancement of boundaries is essential for the classification of suspicious regions in ultrasonic medical B scan images of internal organs so that malignancies can be identified and detected. Phase congruence has been suggested as a means to delineate the boundaries in images. Estimation of phase congruence requires the use of log-Gabor filters. In this work, spatial phase-only filters are used to generate the phase and magnitude information necessary for the estimation of phase congruence. Taking into account the multiplicative non-Rayleigh nature of speckle in these images, a modified version of phase congruence is used alongside pre-filtering with median filters to reduce speckle. Processing was undertaken on two computer-synthesized images and two B scan images of tissue-mimicking phantoms acquired using a commercial ultrasonic imaging unit. The results show that the modified phase congruence estimated after the filtering with four spatial phase-only filters enhances the boundaries of target-like regions in these images. Since these phase-only filters require fewer parameters than log-Gabor filters, the technique demonstrated in this work can provide a simple means to use phase congruence to highlight boundaries in ultrasonic images corrupted by speckle.     

文本分类检索技术在工程中的应用

根据工程项目中文本特点与用户业务需求,基于向量空间模型,结合示例检索与分类检索技术,设计与实现了文本分类检索系统,以面向对象中类图模型形式描述了系统的实现方法。为解决工程应用中出现的性能等问题,提出了各种改进优化方法,如采用特征提取将向量降维,减少存储空间,提高计算速度;采用分类检索缩小搜索范围,缩小检索时间;定时增量更新向量空间提高处理速度,最终使系统成功应用到了工程项目中。     

一种低复杂度的卷积编码CPM的非相干序列检测算法

连续相位调制(CPM)与卷积编码相结合可以进一步提高系统的功率利用率,这使得它在无线通信领域中得到广泛应用.给出了卷积编码CPM的一种低复杂度的非相干序列检测算法,通过正交化处理有效地减少了匹配滤波器个数;在序列检测阶段通过状态融合减少维特比译码的状态数,然后结合判决反馈进行检测.     

偏振度作为反馈信号的偏振模色散补偿系统的性能研究

在以信号偏振度(DOP)作为反馈信号的偏振模色散补偿系统中．提出了分别利用带通和带阻滤波器来改进反馈信号的灵敏度和监测窗口的方法。比较了40Gbit／s归零(RZ)码传输系统和10Gbit／s非归零(NRZ)码传输系统中滤波器在改进反馈信号监测性能方面的作用．对滤波带宽的选择作了定性的数值分析。结果表明，通过滤波器的引入，可在很大范围内避免补偿算法在搜索中出现局部极值的可能，减少了迂回搜索．改进了补偿效果，同时有利于补偿系统的稳定。     

A VLSI-oriented algorithm and its implementation for AVS chroma interpolation

AVS (audio video coding standard) is the latest multimedia coding standard of China. Similar to H.264/AVC, AVS adopted the technology of fractional-pel-accurate motion compensation, which enhanced the compression efficiency. To obtain fractional pels, 4-tap FIR filters and bilinear filters are used for luma and chroma interpolation respectively. Unlike the VLSI-optimized FIR filters which could be implemented by adders and shifters, the bilinear filter for chroma is not so convenient for direct VLSI implementation due to its multiplications. In this paper, we propose a VLSI-oriented algorithm named SHAM (x–y-separated halved-approaching method) to accomplish the bilinear filtering. The proposed SHAM algorithm adopts a halved-approaching method which is an addition-and-shift-only method and with simpler data path. VLSI structures are also provide to implement the SHAM algorithm in this paper. Experiments based on UMC $0.18\mathrm{\mu }\mathrm{m}$ process show that the SHAM algorithm could be implemented with about 48% less silicon area or at doubled frequency compared with the direct implementation of the bilinear filter.     

高效/超高效过滤器自动扫描检漏系统的研制

基于欧洲标准EN 1822构建了一套高效/超高效过滤器自动扫描检漏系统.首先描述了扫描检漏测试台的整体管路系统,然后介绍了控制系统的硬件部署,接下来详述了扫描检漏的具体过程,最后对两台H14的高效过滤器进行了在线检测验证.该系统可检测多种尺寸规格和等级的高效/超高效过滤器,能够给出过滤器的局部和全局效率,以及漏点的坐标范围.     

Two-dimensional filter bank design for optimal reconstruction usinglimited subband information

In this correspondence, we propose design techniques for analysis and synthesis filters of 2-D perfect reconstruction filter banks (PRFB's) that perform optimal reconstruction when a reduced number of subband signals is used. Based on the minimization of the squared error between the original signal and some low-resolution representation of it, the 2-D filters are optimally adjusted to the statistics of the input images so that most of the signal's energy is concentrated in the first few subband components. This property makes the optimal PRFB's efficient for image compression and pattern representations at lower resolutions for classification purposes. By extending recently introduced ideas from frequency domain principal component analysis to two dimensions, we present results for general 2-D discrete nonstationary and stationary second-order processes, showing that the optimal filters are nonseparable. Particular attention is paid to separable random fields, proving that only the first and last filters of the optimal PRFB are separable in this case. Simulation results that illustrate the theoretical achievements are presented.     

Bandwidth Occupancy in PSK Systems

For phase-shift keying (PSK) systems a method has been presented to determine the filter parameters so that the degradation produced by the bandlimiting filters is tolerable and as many channels as possible can be accommodated in a given RF band. Thermal noise present in the system and intersymbol and interchannel interference are considered the major sources of impairment in the system, and these are the only sources of impairment considered in this paper. The method is here applied to a binary coherent PSK (CPSK) system when unequalized Butterworth and Chebyshev filters of different complexities are used as receiving filters, and suitable filter parameters have been determined.