不同开孔率的多孔孔板水力空化装置的图像分析

设计了一套实用有效的水力空化实验装置,利用高速摄影的方法研究多孔孔板结构参数对水力空化效果的影响,总结得出评价水力空化效果的有效方法。研究得出：利用孔板后的平均灰度值可以很好的反映管路中的空化效应;多孔孔板的开孔率是影响水力空化效果的主导因素。每个管路都存在一个最佳开孔率,使管路水力空化效果最优;管路阻力系数随着开孔率的增加明显减小。图11表1参10     

孔板为发生器的水力空化装置的实验研究

孔板是以多洞孔板为水力空化发生器的水力空化装置的关键,孔板的参数如:开孔孔径、开孔个数、孔排布方式、孔板厚度对空化效果有着重要的影响.文章分析了孔板的开孔率及孔的排布方式(分为均布和辐射状分布)2个因素对孔板前压力、孔板前后压差的影响,结果表明:在开孔率相同的情况下,通过改变孔的排布方式可以显著改变管路的最大流量,在开孔率为0.035时,均布排布较辐射状排布时的管路最大流量增大至0.8 m3/h;在开孔率为0.042时,在特定的流量范围11.5～12.5 m3/h之间时,随孔的3种排布方式(均布、辐射状分布12×4、辐射状分布16×3)的不同,孔板前压力、孔板前后压差有明显的变化.     

开孔率对多孔板水力空化装置影响的实验研究

水力空化装置是利用水力空化技术的关键,而多孔板则是以多孔板为发生器的水力空化装置的最重要部分。多孔板的参数,如：开孔孔径、开孔个数、孔的排布方式、孔板厚度等,对空化效果有着重要的影响。文章分析了孔板的开孔率对管路最大流量、孔板前压力、孔板后压力和孔板前后压差等的影响。根据实验结果,可以得到以下结论：管路的最大流量受到开孔率的限制。而板前后压力差与孔口断面时均流速的关系却与开孔率无关。     

纺织厂空调喷水室挡水板性能研究

探讨纺织厂空调喷水室挡水板的性能。介绍了挡水板过水量和阻力的概念,分析了影响挡水板过水量和阻力的因素。对某厂细纱9号空调室挡水板的性能进行了的实际测试,计算了高风速和低风速两种情况下挡水板的阻力、阻力系数和过水量。结果表明:在低风速(3.3 m/s)时,挡水板平均阻力为65.6 Pa,阻力系数为10.693,过水量为0.746 g/kg干;在高风速(4.3 m/s)时,挡水板平均阻力为162.0 Pa,阻力系数为15.064,过水量为2.135 g/kg干。认为:与低风速相比,高风速时的阻力、阻力系数和过水量均有明显增大;实际过水量的值比理论取值偏大;实际补水量取值比理论取值偏小。     

非织造布过滤板的阻力特性研究

本文使用介质阻力系数和介质阻力压缩因子两个可比性较强的介质阻力特性参数，对新型过滤介质非织造布过滤板的阻力特性同两种纸质滤板进行了对比研究，其结果表明，非织造布过滤板的介质阻力系数，介质阻力压缩因子及介质阻力系数的周期变化幅度均较小，其阻力特性明显优于纸质滤板。     

2003年度国家烟草专卖局科学技术进步奖获奖项目简介(Ⅰ)

1　内涵式纺丝技术创新　　该项目是在原引进的美国直径为5 4mm、孔数为2 5 0孔喷丝帽纺丝技术相配套的工艺及设备基础上,通过技术创新,将喷丝帽的孔数增加到35 0孔的纺丝新技术及其配套新工艺,使生产能力在原基础上提高了2 0 7% ,生产多规格品种低旦丝束的能力提高了3 92倍。该项目取得的10项技术创新成果是:①突破了美国塞拉尼斯公司采用的浆液过滤理论和模式,优化了压滤机及其管路的配置,提高了浆液的过滤质量和过滤能力;②探索出丝束粘连的形成机理,成功研发出高温快干纺丝工艺,解决和掌握了多孔超细喷丝帽的清洗工艺和技术;③改进了丝…     

蒸汽计量仪表的选用,安装和维护

蒸汽计量仪表的选用、安装和维护葛国庆（安徽省和县造纸厂２３８２６７）关键词孔板，变送器，二次仪表我厂目前拥有蒸汽测量系统数十套，分别安装在动力、制浆和造纸的进出汽管路上，根据我们对其中几套的安装以及日常维护，总结以下几点经验。孔板由于孔板结构简单、加...     

微孔膜气调包装内外气体交换数学模型的建立

依据气体传质基础理论,基于Fick 定理建立微孔膜气调包装内外气体交换的数学模型。以无产品的微孔膜气调包装实验分析孔参数对包装内气体体积分数的影响,并验证数学模型。结果表明,孔径和孔数对包装内气体体积分数变化的影响显著,膜厚影响不显著,且模型预测值与实验数据吻合度较高。     

单孔孔板水力空化器结构参数的数值分析

为了预测单孔孔板水力空化器结构参数对水力空化效果的影响,基于流体计算软件Fluent,采用λ-ε双方程湍流模型,针对单孔孔板水力空化器孔直径、孔板厚度及进口压力对孔板水力空化效果的影响进行了数值模拟计算,获得了压力分布、湍动能以及流线速度矢量分布图等数据.结果表明,在孔的出口段靠近孔的区域存在空化发生区和空泡破灭区.这一区域的大小随孔直径的增加而增大,随孔板厚度的增加而增大.湍动能和速度矢量之间有着密切的联系,湍流漩涡的作用范围随孔直径和孔板厚度的增加而变大.进口压力对孔板式水力空化发生器空化效果的影响随压力的增大成线性变化,对于空化效果没有决定性的影响.通过比较分析,得出内径为32 mm的单孔孔板式水力空化发生器的最佳孔直径约为1.6 mm,孔板厚度约为14 mm.     

湿纺喷丝头的材质、孔形与可纺性的关系

在化纤生产中,喷丝头的质量是保证成品纤维的物理机械性质和良好的纺丝工艺的重要条件。湿纺纤维所用的湿纺喷丝头无论在材质、孔数、孔经、孔形及孔的排列等方面都比干纺或熔纺纤维喷丝头要求严格。目前,湿纺纤维大多采用大面径多孔喷丝头,孔数在2～10万孔,甚至高达20～30万孔。因此,研究湿纺喷丝头的结构特性与纤维成形工艺间的关系,对提高纤维质量和     

外流板式降膜蒸发器的传热性能：人工神经网络方法研究

根据外流板式降膜蒸发器实验装置的传热实验数据，建立了传热元件板片温度分布的人工神经网络模型。在模拟结果的基础上，定义了一个蒸发侧液膜热阻在总热阻中的比率值Ｌｃ，此称为液膜热阻系数Ｌｃ值的分布，清楚地展示了传热元件板片上的热阻分布，并由此得出改善传热的若干启示。     

Protective effect of a marine oligopeptide preparation from Chum Salmon (Oncorhynchus keta) on radiation‐induced immune suppression in mice

BACKGROUND: A marine oligopeptide preparation (MOP) obtained from Chum Salmon (Oncorhynchus keta) by the method of enzymatic hydrolysis, has been found to enhance the innate and adaptive immunities through stimulation of the secretion of cytokines in mice. The current study aimed to further investigate the protective effect of MOP on radiation‐induced immune suppression in mice. RESULTS: Female ICR mice (6–8 weeks old) were randomly divided into three groups, i.e. blank control, irradiation control and MOP (1.350 g kg^?1 body weight) plus irradiation‐treated group. MOP significantly increased the survival rate and prolonged the survival times for 30 days after irradiation, and lessened the radiation‐induced suppression of T‐ or B‐lymphocyte proliferation, resulting in the recovery of cell‐mediated and humoral immune functions. This effect may be produced by augmentation of the relative numbers of radioresistant CD₄⁺ T cells, enhancement of the level of immunostimulatory cytokine, IL‐12, reduction of the level of total cellular NF‐κB through the induction of IκB in spleen and inhibition of the apoptosis of splenocytes. CONCLUSION: We propose that MOP be used as an ideal adjuvant therapy to alleviate radiation‐induced injuries in cancer patients. Copyright © 2010 Society of Chemical Industry     

Effect of Fouling on Flux and on Energy Requirements in Reverse Osmosis of Skim Milk

The effects of fouling on the permeate flux and on the power and energy required in the process of concentrating skim milk by a plate and frame type reverse osmosis unit with 990 type cellulose-acetate membranes were investigated. The permeate flow characteristics indicate that the fouling layer is rapidly formed and that its resistance is nearly constant over reasonable processing intervals. These fouling properties permit the correlation of permeate flow, overall mass transfer coefficient, and osmotic pressure difference in terms of the energy required per permeate volume versus time. This correlation shows a decrease in energy required per permeate volume with increasing mass transfer coefficient and time. These flow characteristics permit the estimation with confidence of the permeate flow energy requirements and the capacity of a full scale plant. Mass transfer coefficients were estimated for the membrane, the polarized layer, and the fouling layer. The overall mass transfer coefficient was then calculated. The polarized and fouling layers are films of components from the skim milk. Fouling was the controlling resistance.     

巴戟天多糖亲和柱层析纯化的研究

通过静态吸附的方法探讨了巴戟天粗多糖在Con A Sephorose4B亲和填料上静态吸附和脱附情况。结果表明,吸附过程中的pH值和离子强度对平衡吸附量有明显影响,得到的最佳吸附条件是pH7.5,NaCl浓度0.1mol/L;确定的最佳脱附条件为是pH6.5,α-D-甲基葡萄糖苷浓度0.02mol/L。由Langmuir方程对实验数据进行拟合,得到填料的最大吸附量qm为9.58mg/g,表观解离常数Kd为3.43mg/g,巴戟天粗多糖在填料上的吸附速率K为0.144mg/h。在最佳的吸附和洗脱条件下,巴戟天粗多糖被分为MOP-A1和MOP-A2两个组分。     

不同种类钾肥对香料烟产质量的影响

本文通过田间试验探讨了施用不同种类钾肥对香料烟产量的影响。试验结果表明:施用氯化钾和硫酸钾均能显著提高香料烟烟叶的产量;同时还能改善烟叶的外观质量和内在品质,主要表现在一级和二级烟叶比例的增大,烟叶含钾量、总糖量、施木克值及K/Cl比值的提高。值得注意的是,完全施用氯化钾处理的烟叶含氟量(0.93%)接近1.0%的临界值,这有可能降低烟叶的燃烧性。试验还表明:香料烟烟叶的含氟量与主要生育期土壤的含氯量呈极显著正相关,这对生产上确定氯化钾的适宜用量具有指导意义,有利于缓解香料烟产区硫酸钾供应紧缺的现状。      

Study on thermal resistance of multilayered fabrics under different compressional loads

In this work, the thermal resistance of multilayered fabric ensembles meant for cold weather conditions were studied under different compressional loads. An instrument has been developed to study the thermal resistance of fabrics under different compressional loads. The instrument consists of a test plate, guard plates and a bottom plate. The test plate and guard plates were assembled together as a single entity, which can be moved up and down with a screw shaft. A load cell was connected to the plate assembly to apply the required compressional load on the fabric specimen. Thermal resistance of multilayered fabrics was studied in the developed instrument under different loading conditions. Single-jersey knitted fabric, needle punched fabric and polytetraflouroethylene (PTFE) coated fabrics were used in the inner, middle and outer layer, respectively. Twenty different multilayered fabric ensembles with the same inner and outer layers were studied. The middle layers, i.e. needle punched nonwoven fabrics, were produced from polyester hollow fibres, with varying linear density of fibre, mass per unit area and punch density. The thermal resistance of multilayered fabrics obtained from the developed instrument was compared with the thermal resistance of instruments, namely sweating guarded hot plate (SGHP) and Alambeta. Regression equations were developed and the contour plots were drawn to analyse the effect of the fibre, fabric and process parameters. ANOVAs were conducted to find the significance of the compressional load, linear density of fibre, mass per unit area and punch density on the thermal resistance of fabrics. It was found that the thermal resistance obtained from the instrument follows the same trend as that of thermal resistance obtained from SGHP and Alambeta. Mass per unit area was found to have significant effect on the thermal resistance of multilayered fabrics under different compressional loads. The effect of punch density decreases with the increase in compressional load on the thermal resistance of multilayered fabrics. The thermal conductivity of multilayered fabrics was observed to increase with the increase in the compressional load.     

Immunomodulatory effects of marine oligopeptide preparation from Chum Salmon (Oncorhynchus keta) in mice

To observe the immunomodulatory effects of marine oligopeptide preparation (MOP) from Chum Salmon (Oncorhynchus keta) by the method of enzymatic hydrolysis, female ICR mice (6–8 weeks old) were administered the MOP for four weeks with the dose of 0, 0.22, 0.45 and 1.35 g/kg/body weight. In comparison with the control group, the MOP could significantly enhance the capacity of lymphocyte proliferation induced by the mitogen concanavalin A, the number of plaque-forming cells, natural killer cell activity, the percentage of CD4⁺ T helper (Th) cells in spleen and the secretion of Th1 (IL-2, IFN-γ) and Th2 (IL-5, IL-6) type cell cytokines. Nevertheless, no significant differences in weight gain, lymphoid organ indices and phagocytosis capacity were observed in our study. These results suggest that MOP is a possible immune stimulant and may strengthen the immune response of its host.     

异形竖板降膜蒸发器浓缩耐温淀粉酶溶液的传热性能

研究了异形竖板降膜蒸发器浓缩耐温淀粉酶溶液时的传热性能,得出了传热系数与蒸发温度、单位周边流量,传热温差和酶液浓度之间的实验关联式,分析了一些主要因素对传热性能的影响,并与管式降膜蒸发器的传热性能进行了比较,研究结果表明,异形竖板降膜蒸发器具有良好的传热性能,优于管式降膜蒸发器,适宜浓缩耐温淀粉酶。     

Evaluation of the petrifilm plate method for the enumeration of aerobic microorganisms and coliforms in retailed meat samples.

This study was designed to compare the effectiveness and applicability of the Petrifilm plate method with the Association of Official Analytical Chemists' (AOAC) standard aerobic count method and violet red bile agar method for meat products. The comparison was carried out using 303 meat samples collected from various retailers: 110 pork samples, 87 chicken samples, and 107 beef samples. In the comparison of the correlation coefficient (R) between the conventional method and the Petrifilm plate method by a linear regression analysis, the correlation coefficient in total microorganisms was 0.99, 0.95, and 0.94 in pork, beef, and chicken samples, respectively. The correlation coefficient in coliform count was 0.83, 0.96, and 0.81 in pork, beef, and chicken samples, respectively. Based on the high correlation in the total microorganism count, it might be possible to replace the conventional methods with the Petrifilm plate method. For coliform counts, the Petrifilm plate method also showed a generally high correlation coefficient, except for pork samples, which are more subject to contamination. The Petrifilm plate method was simpler and less time-consuming in sample preparation and, in procedures, faster than the conventional method. These results suggested that the 3M Petrifilm plate method could replace the conventional methods in the analysis of microorganism contamination measurement in meat products.     

高电阻电热合金扁丝面积修正系数的验证

高电阻电热合金扁丝的每米电阻值和电阻率是生产、检验和使用过程中的重要技术参数，其相互换算与材料的横截面积有关。高电阻电热合金扁丝是由圆丝轧制而成，属不切边型，宽度乘厚度的矩形面积和实际面积间的关系由面积修正系数来决定。我国一直沿用瑞典康太尔公司的０９２系数计算电阻率和每米电阻值，其误差太大。通过实验测算法对系数进行了验证，验证结果表明，系数取０９６更接近于实际，精确度达万分之几。