环模制粒机中环模结构型孔的有限元分析

苜蓿草粉对环模系统的磨损是造成饲料制粒机关键部件环模失效的主要原因.本研究应用Pro/E及ANSYS软件完成三种类型环模型孔的建模及有限元静力分析.得到了三种类型环模型孔沿轴向路径的应力与变形分布,找到了环模孔倒角与环模孔轴向路径的应力与变形的影响关系,60°倒角环模孔结构好,为环模进行结构优化提供了依据.     

不同种植年限蔬菜地土壤导水性能及影响因素

对天津市蔬菜基地种植15年以上、10年以上、5年以上和未种植过蔬菜的土壤进行分析,结果表明,土壤容重和孔隙度的演变在各项理化性质中占主导地位。蔬菜地土壤容重、有机质含量随着种植年限的延长而增加;土壤孔隙度和微团聚体含量随着种植年限的增加逐渐降低。原状土壤饱和导水率变化范围为58.72×10-4~86.65×10-4cm/s,随着种植年限的延长田间土壤导水性能降低;扰动土壤饱和导水率变化范围为0.57×10-4~2.07×10-4cm/s,随着种植年限的延长而相对降低。该结果可为天津地区种植年限较长的蔬菜地土壤,特别是耕作层土壤结构改善及水分的有效利用提供参考。     

Intravenous lipid emulsion for treating permethrin toxicosis in a cat

A 2-year-old cat was presented with acute onset seizures, tremors, and hypersalivation. Permethrin toxicity was diagnosed based on a history of recent flea treatment. Measures were taken to minimize further absorption of permethrin, and methocarbamol and intravenous lipid emulsion were used to control tremors. The cat recovered and was discharged within 42 h.     

Seroprevalence of feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) in shelter cats on the island of Newfoundland,Canada

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses found within domestic and wild cat populations. These viruses cause severe illnesses that eventually lead to death. Housing cats communally for long periods of time makes shelters at high risk for virus transmission among cats. We tested 548 cats from 5 different sites across the island of Newfoundland for FIV and FeLV. The overall seroprevalence was 2.2% and 6.2% for FIV and FeLV, respectively. Two sites had significantly higher seroprevalence of FeLV infection than the other 3 sites. Analysis of sequences from the FeLV env gene (envelope gene) from 6 positive cats showed that 4 fell within the FeLV subtype-A, while 2 sequences were most closely related to FeLV subtype-B and endogenous feline leukemia virus (en FeLV). Varying seroprevalence and the variation in sequences at different sites demonstrate that some shelters are at greater risk of FeLV infections and recombination can occur at sites of high seroprevalence.     

基于Pro/E的高度可调式人机学座椅设计

日常生活中随处可见的座椅给人们带来了很大的舒适性,但也出现了因长时间保持坐姿而产生的腰酸背痛情况。原因在于传统座椅的设计较少引入人体因素,因此,只有运用人机学原理设计的新型座椅才能解决这一问题。此外,诸如Pro/E之类的CAD软件也应该在现代设计中得到广泛应用,故本文尝试使用Pro/E建立模型。     

Heinz body hemolytic anemia associated with high plasma zinc concentration in a dog

Acute zinc toxicosis from the ingestion of pennies was diagnosed in a dog with Heinz body hemolytic anemia (PCV = 14%), leukocytosis (51,000 cells/ml) with a left shift (3,060 band neutrophils; 37,740 segmented neutrophils) and monocytosis (4,080 cells/ml), azotemia (BUN = 60 mg/dl), bilirubinemia (total bilirubin = 5.3 mg/dl), hypokalemia (3.0 mEq/L), high serum alkaline phosphatase activity (691 U/L), high total plasma solids (8.1 g/dl), hemoglobinuria, and proteinuria. Despite aggressive medical treatment, renal failure ensued, and the dog died of cardiac arrest. The clinical signs, clinical course, and laboratory findings in this dog were similar to what has been reported in other cases of acute zinc toxicosis in dogs, with the exception of a history of generalized seizures and the findings of Heinz bodies. Although a causative relationship between plasma zinc values and Heinz body formation cannot be proven, their association suggests that oxidative damage to erythrocyte hemoglobin and cell membrane proteins may be involved in the pathogenesis of zinc-induced hemolysis.