超声在陶瓷膜微滤中药口服液过程中的应用研究

研究了在线超声技术在无机陶瓷膜微滤中药口服液中的应用.以膜渗透通量、膜污染阻力分布等为指标,考察了在线连续超声与正常微滤在口服液微滤中的差异,进而对操作条件进行优化.结果表明,超声能显著增强膜的渗透通量,增液口服液、黄芪精口服液的通量提高率分别为26.6%和44.6%.超声波还能有效控制膜表面污染.采用超声强化陶瓷膜微滤中药口服液能有效的减少膜污染、提高膜的利用效率.     

预处理技术优化黄芩水提液“溶液环境”及其对膜蒸馏浓缩过程的影响

为综合探讨膜蒸馏技术浓缩中药水提液的可行工艺,以黄芩水提液为研究对象,通过不同的预处理组合技术调节黄芩水提液"溶液环境",比较不同预处理组合对共性高分子物质去除率、物理化学参数、指标性成分保留率、特征指纹图谱相似度以及膜通量变化等的差异,并基于最佳预处理进行了膜蒸馏工艺优化.研究表明,采用离心加(6~8)万膜超滤的预处理技术,黄芩水提液的4种高分子成分的截留率较高;浊度、黏度下降,澄明度提高;指标性成分黄芩苷保留率为92.85%,特征性指纹图谱的相似度高.同时膜蒸馏过程操作参数的影响程度为温度真空度流量,在(61±1)℃、(0.094±0.01)MPa、1.0LPM条件下,可避免膜润湿现象,保证蒸馏浓缩过程的稳定.     

混凝-陶瓷膜微滤处理阴极电泳漆废水研究

提出用混凝与陶瓷膜微滤组合工艺处理阴极电泳漆废水的方法,研究了pH值对CODCr去除率的影响,操作压差、膜面流速对膜通量的影响,得到了适宜的操作条件和有效的膜清洗方法.结果表明:料液pH值为6.7时,混凝过程对CODCr去除率的贡献约63%,之后的微滤使废水中CODCr的去除率增加到85%.采用平均孔径为0.2μm的氧化锆膜,在膜面流速4.2 m/s,压差0.10 MPa,温度30℃,膜稳定通量约250 L/(m2.h),渗透液可作为涂装车间循环冲洗水用.混凝作为前处理过程有助于提高膜的渗透通量,降低膜污染,改善出水水质.     

终端陶瓷膜法海水淡化预处理

采用低能耗的终端过滤方式进行陶瓷膜法海水淡化预处理,比较了"絮凝沉降 陶瓷膜"和"砂滤 陶瓷膜"两种预处理工艺.前者延长了膜再生周期,其陶瓷膜的平均渗透通量是后者的1.6倍,达到220 L/(m2·h),产水回收率大于90%.经陶瓷膜预处理后的产水水质稳定,达到反渗透膜的进水水质要求.结果表明,"絮凝沉降 陶瓷膜"预处理工艺明显优于"砂滤 陶瓷膜"预处理工艺.     

垃圾渗滤液膜滤浓缩液的减量技术研究

垃圾渗滤液膜滤浓缩液的高效处理已成为市政与环境污染治理领域的迫切需求.本研究以北京市某垃圾填埋场的渗滤液膜滤浓缩液为研究对象,采用“预处理-气隙膜蒸馏”组合工艺对其进行减量化处理.我们研究了不同组合工艺对浓缩液处理效果的影响,发现从实用性角度考虑,混凝沉淀预处理对于浓缩液的减量化过程具有最佳的运维保障效果,可将膜滤浓缩液的体积减少80%以上.合适的预处理可以显著降低膜污染的程度,提高膜蒸馏膜通量的稳定性和浓缩倍数.     

微滤和反渗透膜组合工艺浓缩罗汉果汁的研究

采用微滤(MF)和反渗透(RO)膜组合工艺浓缩罗汉果汁.研究了反渗透膜浓缩罗汉果汁的最佳操作运行条件:压力1.4～1.6 MPa,温度36±1℃,浓缩比达到4.6时对膜进行化学清洗以恢复膜通量.由于反渗透法对预处理技术要求较高,采用微滤陶瓷复合膜作为预处理系统,能够很好地保持反渗透膜的通量.这种膜组合处理效果较佳,得到的果汁澄清透明.反渗透法预浓缩罗汉汁比蒸发法大大节省了能耗.     

预处理方式对透明质酸发酵液的超滤膜污染影响的研究

叙述了透明质酸（HA）发酵液经5种不同预处理方法处理后,所获得清液在超滤过程中通量J的变化规律,通过比较预处理前后发酵液中透明中质酸浓度和分子量的变化;超滤前后膜通量的变化及酶液处理后膜通量的变化,探讨了膜超滤过程中污染规律及预防方式。     

反渗透膜处理PVC离心母液

采用反渗透膜分离技术对PVC离心母液进行试验,研究了不同进膜压力对膜通量、渗透液电导的影响.在确定了压力参数后.分析了运行时间对膜通量、渗透液电导、COD的影响.试验结果表明.第一次通过RO膜的渗透液电导为42.3 μs;在进膜压力为1.0 MPa,膜设备运行30 min情况下.第二次通过RO膜的渗透液电导为7.37 μs,COD接近于0.出水达到排放标准.经进一步处理可回用于生产.     

陶瓷膜澄清食醋的工艺研究

采用陶瓷膜技术澄清食醋时加了预处理工序,对有无预处理工序的两种工艺进行了膜通量变化和膜再生的对比研究.结果表明:预处理后的食醋经陶瓷膜澄清时,通量衰减缓慢,膜再生效果好.在此工艺路线下研究了各影响因素对膜通量的影响,确定了适宜的工艺参数:膜孔径80 nm、跨膜压差0.14 MPa、雷诺数6 000、料液温度25~30℃、浓缩倍数不大于10;采用分步反冲技术使平均膜通量维持在43 L/(m2.h)以上;化学清洗方法可使膜通量恢复至96%以上;澄清后的食醋的质量指标均符合国家标准,避光放置18月以上无返混现象.此工艺比单独膜澄清时的膜使用寿命增加0.5年左右,运行成本减少了3.71元/t(现在生产成本为30.01元/t).系统运行近两年,运行稳定.     

海水预处理一体化混凝-微滤工艺

针对渤海近岸海水浊度高、有机物和悬浮固体含量大等特点,开发了一体化混凝-微滤工艺对海水进行预处理.系统较长时间运行表明,出水水质好,能满足海水反渗透进水的要求.对污染的膜进行系统清洗后,膜通量基本可恢复至新膜水平;膜表面沉积物中Ca2 、Mg2 等的化合物含量较高;NaOCl溶液可有效洗脱膜表面UV254所代表的腐殖质类天然有机物.     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

卧式金属罐容量的测量结果不确定度

本文根据多年的实践检定经验 ,参照JJF1 0 59- 1 999《测量不确定度评定与表示》以及《测量不确定度表达 1 0讲》 ,对卧式金属罐容量的测量结果不确定度进行了评定。     

盐酸浓度不确定度的评估

通过对盐酸浓度标定的过程分析，找出影响结果的各个分量，进行不确定度的评定，按照计量技术规范给出标准的表示法。     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle.