Prediction and measurement of residual stresses in injection molded parts     

Young Il Kwon  Tae Jin Kang  Kwansoo Chung  Jae Ryoun Youn 《Fibers and Polymers》2001,2(4):203-211

Residual stresses were predicted by a flow analysis in the mold cavity and residual stress distribution in the injection molded product was measured. Flow field was analyzed by the hybrid FEM/FDM method, using the Hele Shaw approximation. The Modified Cross model was used to determine the dependence of the viscosity on the temperature and the shear rate. The specific volume of the polymer melt which varies with the pressure and temperature fields was calculated by the Tait’s state equation. Flow analysis results such as pressure, temperature, and the location of the liquid-solid interface were used as the input of the stress analysis. In order to calculate more accurate gap-wise temperature field, a coordinate transformation technique was used. The residual stress distribution in the gap-wise direction was predicted in two cases, the free quenching and the constrained quenching, under the assumption that the shrinkage of the injection molded product occurs within the mold cavity and that the solid polymer is elastic. Effects of the initial flow rate, packing pressure, and mold temperature on the residual stress distribution was discussed. Experimental results were also obtained by the layer removal method for molded polypropylene.  相似文献   

Confocal microscopy measurement of the fiber orientation in short fiber reinforced plastics     

Kwang Seok Lee  Seok Won Lee  Jae Ryoun Youn  Tae Jin Kang  Kwansoo Chung 《Fibers and Polymers》2001,2(1):41-50

To determine three-dimensional fiber orientation states in injection-molded short fiber composites a CLSM (Confocal Laser Scanning Microscope) is used. Since the CLSM optically sections the composites, more than two cross-sections either on or below the surface of the composite can be obtained. Three dimensional fiber orientation states can be determined with geometric parameters of fibers on two parallel cross-sections. For experiment, carbon fiber reinforced polystyrene is examined by the CLSM. Geometric parameters of fibers are measured by image analysis. In order to compactly describe fiber orientation states, orientation tensors are used. Orientation tensors are determined at different positions of the prepared specimen. Three dimensional orientation states are obtained without the difficulty in determining the out-of-plane angles by utilizing images on two parallel planes acquired by the CLSM. Orientation states are different at different positions and show the shell-core structure along the thickness of the specimen.  相似文献   

Injection stauntoniae inhibits chronic inflammatory pain responses by changing COX-2 expression in carrageenan-inflamed mice     

YANG Yan-jing  LI Xiao-jun  LIU Li-wei  GUO Qiang  LI Yu-sang  Feng Li-jing  TANG He-bin 《园艺学报》2014,30(7):1214-1217

AIM：To investigate the effect of injection stauntoniae (IS) on inflammatory pain responses in mice. METHODS：The carrageenan test was used to determine the anti-inflammatory and analgesic effects of IS. Except for control group, the mice in other groups received an injection of λ-carrageenan solution (1%, 50 μL) into the plantar region of the left hind paws, followed by a subcutaneous injection of IS at doses of 12.5%, 50% and 100% or equal volume of 0.9% NaCl. Both paw edema and hyperalgesia to thermal stimulation were measured 4 h, 12 h, 24 h and 48 h after the injection of λ-carrageenan solution. The lumbar-5 (L5) dorsal root ganglions (DRGs) of the mice were taken to investigate the cyclooxygenase 2 (COX-2) expression by immunohistochemical staining. RESULTS：Subcutaneous injection of IS potently inhibited paw edema and hyperalgesia induced by λ-carrageenan in the mice accompanied with the inhibition of COX-2 protein expression in L5 DRGs. CONCLUSION：IS exerts the anti-inflammatory and analgesic effects on the inflammatory responses by inhibiting the protein expression of COX-2 in DRGs.  相似文献   

三类中药制剂对急性肾衰影响的比较   总被引：1，自引：1，他引：0  

王华 周孝琼李焰  陈小红 《中国农学通报》2013,29(32):54-57

为了研究瘟清注射液、香丹注射液和术苓注射液对内毒素所致急性肾衰家兔的防治作用。将40只健康哈尔滨白兔随机分为阴性对照组、模型组、瘟清组、香丹组和术苓组,每组8只。模型组和各防治组家兔一次性静脉注射大肠杆菌O111B4内毒素生理盐水溶液;三防治组家兔在注射内毒素后立即静脉注射相应的中药注射液;阴性对照组静注生理盐水。各组家兔静注液体的总量相等。注射内毒素（或生理盐水）1 h后开始通过膀胱瘘管收集尿液,每小时收集1次,共收集6 h。末次收集尿液后心脏采血。对各组家兔的肾功能指标进行动态测定。结果显示：模型组家兔发生了急性肾功能衰竭。和模型组比较,瘟清组家兔的肌酐、尿素氮排出量显著或极显著增加（P〈0.05,P〈0.01）,肾衰指数和钠排泄分数显著或极显著降低（P〈0.05,P〈0.01）,内生性肌酐清除率显著或极显著升高（P〈0.05,P〈0.01）。除肾衰指数和钠排泄分数之外,香丹组家兔绝大多数肾功能指标的变化趋势与瘟清组相似。试验结果表明：瘟清注射液对急性肾衰具有确实的防治作用;香丹注射液亦有良好的防治急性肾衰作用;术苓组家兔肾功能衰竭状况并未得到根本好转。  相似文献   

高效凝胶渗透色谱法测定人参糖肽注射液的重均分子量     

陈英红  罗浩铭  王颖  姜瑞芝 《特产研究》2013,(4):55-57

建立人参糖肽注射液分子量分布测定方法。色谱柱为多糖专用凝胶柱OHpak SB-802HQ（8mm×300mm）,以0．9％氯化钠为流动相,流速0.5mL／min,示差折光检测器。人参糖肽注射液重均分子量为900—1100u。本实验建立的多糖分子量测定方法具有简便、快速和重现性好的特点,为提高和完善该制剂的质量标准提供了依据,同时可作为指纹图谱从多糖肽分子量角度来控制该产品的内在质量。  相似文献   

顶隙柱塞在非道路国Ⅱ排放柴油机中的研究及应用     

闫亮  张继卫  祖江陵 《拖拉机与农用运输车》2012,39(4):8-10

对顶隙柱塞的工作原理进行分析,对我公司现生产的顶隙柱塞和普通柱塞的喷油提前特性进行了对比分析,并在某一非道路国Ⅱ排放发动机上进行性能及排放试验。试验结果表明,顶隙柱塞能够满足非道路国Ⅱ排放柴油机的性能和排放要求,具有推广价值。  相似文献   

澳洲茄胺盐酸盐注射剂对小鼠Lewis肺癌抑瘤作用研究     

李富仁  丑莉莉  刘良 《吉林林学院学报》2011,(1):50-52

目的通过3次抑瘤实验观察研究澳洲茄胺盐酸盐注射剂对小鼠Lewis肺癌的抑瘤作用.方法通过肿瘤细胞悬液接种法,制备小鼠Lewis肺癌动物模型,采用腹腔注射给药法,连续7 d,2次/d.给药结束后解剖小鼠,取瘤称重,观察药物作用.结果从给药剂量上来看,与对照组比较,11 mg/kg剂量组开始出现抑瘤作用,抑瘤率为43.82%,P〉0.05,虽有抑瘤作用,但无统计学意义;22 mg/kg组抑瘤率为65.32%,P〈0.001;33 mg/kg组抑瘤率为66.92%,P〈0.001;44 mg/kg组抑瘤率为78.53%,P〈0.001;55 mg/kg组抑瘤率为79.73%,P〈0.001.结论受试药物澳洲茄胺盐酸盐注射剂对小鼠Lewis肺癌有明显的抑瘤作用,受试药物从22 mg/kg剂量组开始到55 mg/kg剂量组为有效剂量组,4个剂量组之间呈现明显的量效关系.  相似文献   

长效土霉素注射液的配方筛选及其质量浓度测定     

刘伟  欧阳五庆  赵蓓  商育锦 《西北农业学报》2011,20(8):35-38

筛选长效土霉素注射液的最优配方,制备长效土霉素注射液,并对土霉素质量浓度进行测定。通过预试验,确定长效土霉素注射液的各组分及其大致范围,以质量浓度变化量为检测指标,利用正交试验确定长效土霉素注射液的最优配方。制备长效土霉素注射液,并利用紫外分光光度法对土霉素有效质量浓度进行考察,计算其回收率。长效土霉素注射液的最优配方为,每100 mL长效土霉素注射液中含有30 g盐酸土霉素、6 g MgCl2、0.6 g甲醛合次硫酸氢钠、60 mL复合有机溶媒(由甘油甲缩醛和聚乙二醇200按照适当比例配制)、7.5 g聚乙烯吡咯烷酮K175、.4 mL单乙醇胺、其余为注射用水。所制备的长效土霉素注射液在5~30mg/L时呈现良好线性关系,平均回收率为97.86%,RSD为1.15%。该长效土霉素注射液的配方合理,土霉素效价稳定,产品回收率高。  相似文献   

地龙注射液免疫活性的体外研究   总被引：3，自引：0，他引：3  

刘英姿  周铁忠 《安徽农业科学》2009,37(35):17514-17515

[目的]探讨地龙注射液的免疫调节活性及其作用机理。[方法]通过地龙注射液体外培养刺激小鼠脾淋巴细胞,采用MTT法和双抗夹心ELISA法测定地龙注射液对小鼠脾淋巴细胞增殖及分泌细胞因子IL-2的影响。[结果]地龙注射液能显著地直接或协同ConA或LPS刺激脾淋巴细胞增殖,也能极显著地增加IL-2的分泌量。[结论]该研究表明地龙注射液具有较明显的免疫调节活性。  相似文献   

参麦注射液对高血压心衰大鼠血浆代谢组学的影响          下载免费PDF全文

钟森杰  李欣春  李琳  胡志希  简维雄  周瑶  姚涛  杨梦 《勤云标准版测试》2019,39(9):1068-1072

目的 研究参麦注射液对高血压心衰大鼠血浆代谢组学的影响。方法 通过8% NaCl高盐饲料喂养Dahl盐敏感性大鼠制造高血压心衰模型,成模大鼠分为模型组、参麦注射液组,并同时设置正常组,干预15 d后,采集正常组、模型组和参麦注射液组大鼠的血浆样本,运用气相色谱-质谱（GC-MS）联用技术及多元统计分析进行研究。结果 3组的代谢图谱存在显著差异。与正常组相比,模型组19种代谢物水平紊乱;经参麦注射液干预后,亮氨酸、鸟氨酸、丙氨酸、4-羟基-脯氨酸、苏氨酸、天冬酰胺、苏糖醇、丙酮酸、尿素浓度向正常方向显著回调,苏糖酸、半胱氨酸、色氨酸、甲基半胱氨酸、花生四烯酸、胆固醇、木糖醇、核糖醇、焦谷氨酸、丙二酸浓度无显著改变,此外还发现异亮氨酸浓度上升。结论 高血压心衰大鼠血浆代谢组学出现变化,参麦注射液能有效改善部分紊乱的代谢物水平,其作用机制与改善糖代谢、氨基酸代谢紊乱,调节支链氨基酸水平相关,未发现有改善脂代谢紊乱的作用。  相似文献