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综述:锥体压入阻力的分析
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作者 姜新新 李雪薇 《四川水泥》 2015年第12期30-30,共1页
锥体贯入度试验被广泛的应用于测量锥头阻力的大小。有的学者依据可行性理论写了一份概述用于分析锥体压入阻力,该理论以较直观的形式论述并通过分析和运用大量的理论来简化被着重强调的假定。根据试验依据和基本原理,每一个理论的约束... 锥体贯入度试验被广泛的应用于测量锥头阻力的大小。有的学者依据可行性理论写了一份概述用于分析锥体压入阻力,该理论以较直观的形式论述并通过分析和运用大量的理论来简化被着重强调的假定。根据试验依据和基本原理,每一个理论的约束条件和有利因素都需要进行评定。在有限的试验数据情况下,根据已测和预测的贯入试验中,小孔扩张理论是与所有观点最为接近。 展开更多
关键词 贯入度试验 压入阻力 小孔扩张理论
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加速试验研究HDPE管材耐慢速裂纹增长性能 被引量:9
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作者 熊志敏 武志军 +2 位作者 华晔 魏若奇 者东梅 《合成树脂及塑料》 CAS 北大核心 2016年第4期60-63,共4页
研究了不同浓度的壬基酚聚氧乙烯醚表面活性剂溶液对高密度聚乙烯(HDPE)管材锥体试验的影响;同时开发了一种复合表面活性剂溶液,并研究其在锥体试验和HDPE全缺口拉伸蠕变试验中的加速效果。结果表明:一般的表面活性剂溶液对HDPE管材慢... 研究了不同浓度的壬基酚聚氧乙烯醚表面活性剂溶液对高密度聚乙烯(HDPE)管材锥体试验的影响;同时开发了一种复合表面活性剂溶液,并研究其在锥体试验和HDPE全缺口拉伸蠕变试验中的加速效果。结果表明:一般的表面活性剂溶液对HDPE管材慢速裂纹增长性能影响不大,而新开发的表面活性剂溶液相对于壬基酚聚氧乙烯醚表面活性剂溶液具有至少1倍的加速效果,极大地加速了HDPE管材的耐慢速裂纹增长性能评价试验,加快了HDPE管材专用树脂的开发工作。 展开更多
关键词 高密度聚乙烯管材 慢速裂纹增长 加速试验 全缺口拉伸蠕变试验 锥体试验
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聚乙烯管材应变硬化模量与裂纹扩展速率相关性研究 被引量:2
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作者 李茂东 陈国华 +2 位作者 杨波 黄晓之 王志刚 《中国塑料》 CAS CSCD 北大核心 2018年第9期96-101,共6页
采用应变硬化试验和锥体试验分别得到不同聚乙烯100(PE100)管材试样的应变硬化模量和裂纹扩展速率,并对它们之间的相关性进行研究,以期验证应变硬化试验法评价PE管材耐慢速裂纹扩展性能的正确性。结果表明,锥体试验中PE管材试样的裂纹... 采用应变硬化试验和锥体试验分别得到不同聚乙烯100(PE100)管材试样的应变硬化模量和裂纹扩展速率,并对它们之间的相关性进行研究,以期验证应变硬化试验法评价PE管材耐慢速裂纹扩展性能的正确性。结果表明,锥体试验中PE管材试样的裂纹扩展程度随着试验时间的增加而增大;应变硬化试验和锥体试验对不同PE管材试样的耐慢速裂纹扩展性能评价结果完全相同,应变硬化试验法评价PE管材耐慢速裂纹扩展性能的正确性得到验证;应变硬化试验不仅误差较小,而且可以区分不同牌号PE100管材耐慢速裂纹扩展性能的细微差异,评价结果相对于锥体试验要更加可靠。 展开更多
关键词 聚乙烯管材 慢速裂纹扩展 应变硬化试验 锥体试验 相关性研究
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In-vitro and In-vivo Anti-trypanosomal Activity of Terminalia chebula Retz Dried Fruits 被引量:1
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作者 Shaba Peter Sahab Dey +1 位作者 Singh Raj Kumar Chaudary Paulad 《Journal of Pharmacy and Pharmacology》 2016年第9期492-500,共9页
African trypanosomosis had caused lots of havocs to both humans and animals over a century with successes and failure in curtailing it. This study was aimed at screening medicinal plant, Terminalia chebula dried fruit... African trypanosomosis had caused lots of havocs to both humans and animals over a century with successes and failure in curtailing it. This study was aimed at screening medicinal plant, Terminalia chebula dried fruits against Trypanosoma evansi for trypanocidal activity. Twenty grams of powdered Terminalia chebula dried fruits was cold extracted with methanol. Obtained MPE (methanolic plant extract) was in vitro tested against Trypanosoma brucei (1 × 10^6 trypanosomes/mL of the medium in each ELISA plate wells) at concentrations (250~1,000 μg/mL) on Vero cells grown in DMEM (Debecco's Modified Eagle Medium) in appropriate conditions for trypanocidal activity. In-vitro cytotoxicity test of MPE of Terminalia chebula was conducted on Vero cells grown in DMEM. In-vivo assay for trypanocidal activity, each mouse was inoculated with 1 × 10^4/mL of trypanosomes and treated (48 h post inoculation) with MPE of Terminalia chebula at concentrations (12.5, 25, 50, 100 and 200 mg/kg body weight) were administered at dose rate of 100 BL per mouse via intraperitoneal route to different groups of mice, 6 mice per concentration. In-vitro cytotoxicity test was done on Veto cells at concentrations (1.58~100 μg/mL) of MPE of Terminalia chebula. Results of in-vitro trypanocidal activity varied from immobilization, reduction and to the killing of the trypanosomes. At 250 μg/mL ofMPE ofTerminalia chebula dried fruits, there was significant trypanocidal activity at 4 h of incubation and trypanosomes were not detected in corresponding ELISA plate wells at 5 h of incubation, which was statistically equivalent to reference drug, diminazine aceturate (50 μL/mL) at 4 h of incubation. Results of in-vivo trypanocidal activity revealed that at concentrations (l 2.5~25 mg/kg body weight) of MPE of Terrninalia chebula, mice in these groups survived for 6 days. While at 50 and 100 to 200 mg/kg body weight, mice in these groups survived up to 7 and 8 days, respectively. In-vitro cytotoxicity test showed that all concentrations of MPE of Terminalia chenula and diminazine aceturate were cytotoxic to cells except at 1.56 μL/mL and 6.25 μL/mL. In conclusion, MPE of Terminalia chebula dried fruits possessed trypanocidal compounds. Further study (bioassay-guided purification) is required to know the full potential of Terrninalia chebula as future trypanocide candidate. 展开更多
关键词 Terminalia chebula dried fruits in-vitro and in-vivo trypanocidal activity in-vitro cytotoxicity.
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Cardiac Lesions in Naturally Infected Dogs with Trypanosoma cruzi
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作者 K. Y. Acosta-Viana E. Guzman-Marin +3 位作者 M. Jimenez-Coello M. A. Torres-Leon R. F. Colin-Flores A.Ortega-Pacheco 《Journal of Agricultural Science and Technology(A)》 2011年第6期932-938,共7页
With the purpose to determine the frequency and type of cardiac lesions in naturally exposed dogs to Trypanosoma cruzi, ninety one stray dogs, capture by the Canine and Feline Control Center (dog pound) from the mun... With the purpose to determine the frequency and type of cardiac lesions in naturally exposed dogs to Trypanosoma cruzi, ninety one stray dogs, capture by the Canine and Feline Control Center (dog pound) from the municipality of Merida, were studied. Before euthanasia, blood samples were taken to detect 72 cruzi antigens by indirect immunofluorescence antibody test and Western Blot and to detect the genome of parasite by Polymerase Chain Reaction. Immediately after euthanasia, hearts were macroscopically evaluated and a sample of the middle right atrial wall of each dog was taken for histopathological analyses. DNA was also obtained from paraffin blocks of seropositives animals with microscopic lesions to detect 72 cruzi genome. Of ninety one dogs, thirteen were seropositive. All seropositive dogs showed an association (P 〈 0.05) with lymphocytoplasmatic myocarditis. The presence of the 72 cruzi genome was also detected by PCR in cardiac septum tissue of seropositive dogs and in all the cases with microscopic lesions indicating the high pathogenicity of the local circulating strain. No association with macroscopic lesions was observed in seropositive dogs. Also, the presence of Dirofilaria immitis (D. immitis) was found in 6% of dogs evaluated. This study demonstrates a high tropism to cardiac tissue and virulence of the strains of 72 cruzi circulating in the studied dog population. 展开更多
关键词 DOGS Trypanosoma cruzi IFAT PCR myocarditis.
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