微型压电泵中引流道对气泡控制的影响

提出了在泵腔内加工引流道,以促使气泡迅速而有效地排除。从腔内压力方面分析气泡的滞留与输出性能的关系,同时从气泡压力降和流体阻尼方面分析引流道对气泡滞留的影响,最后通过实验验证引流道的引入对压电泵输出性能的影响以及对气泡滞留的优化效果。实验结果表明,引流道的引入能在一定程度上增强压电泵的输出压力和输出流量,引流道宽度为2.0 mm时,输出压力和输出流量分别达到17.4 k Pa和20.8 m L/min;当引流道宽度为1.1 mm和1.5 mm时,压电泵具有很强的气泡排除能力,并根除了断流现象的发生,120个0.02 m L气泡进入后,压电泵仍具有稳定的输出压力(5.8 k Pa和5.6 k Pa)和输出流量(16 m L/min和5.6 m L/min)。在泵腔内加工引流道可以使气泡得到迅速而有效的排除,并减少气泡在泵腔内滞留。     

大型贯流式泵站快速门加速启动过渡过程

为研究大型贯流式泵站机组闸门加速启动过程中的外特性参数变化及流态变化,对灯泡贯流泵机组进行三维建模,采用Fluent软件中的UDF来控制闸门的启动过程,使用铺层法动网格技术来控制闸门处网格生成与消灭,并设定S-A模型作为湍流模型,对灯泡贯流泵机组启动过程进行瞬态数值模拟.计算结果表明:当贯流泵机组快速门以10倍设计速度启动时,机组的转速与流量将以更快的速度达到额定转速与额定流量,同时瞬间最大倒灌流量相比未加速启动时增加了30%.当贯流泵机组处于倒流状态时,靠近轮毂处叶轮叶道压力面的压强呈现出从叶轮进水边向出水边逐渐递增的分布规律.当机组处于零流量的临界状态时,混乱的流态导致压力集中及脱流现象加重,叶轮进水边负压区范围扩大且程度加深.     

银狐垂体细胞系构建研究

分别采用组织块法和消化法2种接种方法进行银狐垂体细胞系构建研究。在消化法中使用不同浓度的胰蛋白酶来检验效果,同时在原代培养期使用反复差速贴壁法纯化,传代培养期结合使用反复差速贴壁以及两步消化法进行处理。结果表明：组织块法接种后成纤维细胞生长明显,原代培养后期成纤维细胞已为主要细胞;降低胰蛋白酶浓度能降低对细胞损伤,但消化时间会增长;采用消化法接种在抑制成纤维细胞生长方面效果好于组织块法。纯化效果上,结合反复差速贴壁法与两步消化法处理后获得了较好的效果,在原代培养时期能较好去除成纤维细胞并通过持续使用该方法可在传二代后获得较高纯度的细胞,纯度能达到80%以上,能够建立细胞系。     

Mutagenesis of the v-mht/mil oncogene in avian carcinoma virus MH2.

Avian carcinoma retrovirus MH2 induces leukemia and solid tumors in chickens and transforms fibroblasts and macrophages in vitro. The genome of MH2 consists of two oncogenes, v-mht/mil and v-myc. Most of the transforming activity of MH2 is attributed to the v-myc oncogene. In contrast, the v-mht/mil oncogene alone does not induce a fully transformed phenotype of avian primary fibroblasts in vitro. It was shown previously that v-mht/mil is the avian homology of the v-raf oncogene in murine sarcoma retrovirus 3611. Because the v-raf oncogene transforms murine fibroblasts very efficiently, the present study tested the hypothesis that an extra segment in the 5' end of v-mht/mil relative to v-raf suppressed the fibroblast-transforming activity of v-mht/mil. By introducing an in-frame deletion of 195 nucleotides into the 5' end of v-mht/mil, the results demonstrate that in the presence of an inactive v-myc oncogene, the 5'-deleted v-mht/mil oncogene fails to transform chicken embryo fibroblasts. Therefore, it is likely that avian primary fibroblasts lack a cellular component that serves as a critical substrate/target for v-mht/mil-induced cellular transformation.     

基于数学形态学的立木树枝信息提取方法

立木树枝信息的提取,是进行立木枝桠遮挡识别的基础。本文提出一种基于数学形态学方法的立木树枝信息提取方法。该方法先利用数学形态学基本运算——腐蚀和膨胀来实现树干信息的提取,然后将枝干的二值图像与提取得到的树干图像做差运算,从而得到树枝信息。实验结果表明,此方法能有效的提取立木图像中树枝的信息。     

Linkage mapping of the mouse nephrosis (nep) gene to chromosome 15.

ICGN is a partially inbred strain of mice with nephrotic syndrome caused by spontaneous glomerular lesion. It has been reported that the albuminuria in ICGN mouse was controlled by at least a single autosomal recessive gene (nep). In this study, we mapped the nep locus by linkage analysis of backcross progeny between ICGN and MSM mice using DNA pooling method. The linkage analysis revealed that the nep locus was localized on the distal part of chromosome 15.     

Relationship between mitogen receptors in peripheral blood lymphocytes and blastogenic responses to mitogen

The relationship between the optimum concentration of mitogen which induces lymphocyte blastogenic response and the receptor occupancy by mitogen was investigated. The receptor occupancies which induced maximal blastogenic activity in equine, bovine and canine peripheral blood lymphocytes (PBL) were 31.1 per cent, 26.5 per cent and 38.4 per cent with phytohaemagglutinin-P, and 48.2 per cent, 17.9 per cent and 24.5 per cent with concanavalin A, respectively. The data clearly show that each animal species had its own optimum concentration of mitogen for stimulation of PBL. Optimum concentration for blastogenesis and number of binding sites of each mitogen had a good correlation with each other for all three species.     

超微粉碎对桑叶粉理化性质的影响

为拓展超微粉碎技术在食品添加剂和药品开发中应用,以桑叶为原料,分别对桑叶粗粉进行干法超微粉碎2 、4、6、8 h,得到4种不同粒径大小的桑叶超微粉,并对桑叶粗粉与4种超微粉的理化性质进行比较。研究结果表明,超微粉碎能明显减小桑叶粗粉的颗粒粒径（P＜0.05）,随着超微粉碎时间的增加,超微粉的粒径减小,粉体的粒径分布范围变窄,比表面积和体积密度显著增加（P＜0.05）,休止角、滑角和膨胀性显著降低（P＜0.05）,水溶性/持水力、持油力、蛋白质的水溶性和多糖的水溶解性均有不同程度的增加,但多酚含量变化不显著（P＞0.05）。扫描电镜结果显示,粗粉经超微粉碎后,其颗粒呈零散的分布形态。说明超微粉碎可改善桑叶粉的部分理化性质,可将这些性质应用于食品添加剂和常规食品开发与加工中。所得研究结果将为超微粉碎技术在桑叶食品中工业化应用提供数据支持和理论依据。     

果奶稳定性和芒果豆奶生产技术研究

对提高果奶稳定性的方法研究表明，果奶必须含有０．４％－１．２％的油酯，ＰＨ值为３．７－４．０，温度为５０－８０℃，单宁含量低于０．３％，均质压力为１８－２５ＭＰａ，在加酸成果汁前后各均质一次，对果奶的稳定效果好。乳化剂和络合剂须与奶粉同时溶解，并经胶体磨充分乳化后再加入稳定剂。当均质后的料液温度低于４０℃时，剧烈搅拌并缓缓加入稀释的果汁或酸，在６５－７０℃杀菌３０ｍｉｎ。按上述工艺生产的果奶和芒果