Zr_(55)Al_(10)Ni_5Cu_(30)非晶态合金的制备与性能研究

采用石墨坩埚浇铸法在真空中频感应熔炼炉中制备Zr55Al10Ni5Cu30合金,并对合金进行了金相、X射线衍射和显微硬度的测试,考察原料纯度、过热度及冷却速率对非晶态合金性能的影响。结果表明,采用工业级原料就可以制备出性能良好的非晶态合金,在低的冷却速率下形成的非晶态合金具有相对较高的硬度,适当提高过热度可以减少微晶的形成。     

TiC(30vol%)/Cu-Al_2O_3复合材料热变形及动态再结晶

采用真空热压-内氧化烧结法制备了TiC(30vol%)/Cu-Al2O3复合材料,测试其基本性能,对其微观组织进行了观察分析。利用Gleeble-1500D热力模拟试验机,在变形温度450~850℃、应变速率0.001~1s-1、变形量50%的条件下,对TiC(30vol%)/Cu-Al2O3进行了热压缩变形试验。通过对流变应力进行分析和计算,构建了该复合材料的本构方程及动态再结晶临界应变模型。利用加工硬化率-应变曲线的拐点和对应偏导曲线最小值的判据,建立了动态再结晶临界应变与Zener-Hollomon参数之间的函数关系。结果表明:TiC(30vol%)/Cu-Al2O3复合材料的真应力-真应变曲线以动态再结晶软化机制为特征,峰值应力随变形温度的降低或应变速率的升高而增加;计算得出该复合材料的热变形激活能为211.384kJ/mol。     

miR-22-3p and miR-30e-5p Are Associated with Prognosis in Cervical Squamous Cell Carcinoma

Alteration in expression of miRNAs can cause various malignant changes and the metastatic process. Our aim was to identify the miRNAs involved in cervical squamous cell carcinoma (SqCC) and metastasis, and to test their utility as indicators of metastasis and survival. Using microarray technology, we performed miRNA expression profiling on primary cervical SqCC tissue (n = 6) compared with normal control (NC) tissue and compared SqCC that had (SqC-M; n = 3) and had not (SqC-NM; n = 3) metastasized. Four miRNAs were selected for validation by qRT-PCR on 29 SqC-NM and 27 SqC-M samples, and nine metastatic lesions (ML-SqC), from a total of 56 patients. Correlation of miRNA expression and clinicopathological parameters was analyzed to evaluate the clinical impact of candidate miRNAs. We found 40 miRNAs differentially altered in cervical SqCC tissue: 21 miRNAs were upregulated and 19 were downregulated (≥2-fold, p < 0.05). Eight were differentially altered in SqC-M compared with SqC-NM samples: four were upregulated (miR-494, miR-92a-3p, miR-205-5p, and miR-221-3p), and four were downregulated (miR-574-3p, miR-4769-3p, miR-1281, and miR-1825) (≥1.5-fold, p < 0.05). MiR-22-3p might be a metastamiR, which was gradually further downregulated in SqC-NM > SqC-M > ML-SqC. Downregulation of miR-30e-5p significantly correlated with high stage, lymph node metastasis, and low survival rate, suggesting an independent poor prognostic factor.     

新型高能叠氮硝胺发射药高压燃烧稳定性研究

为了研究高能发射药膛内燃烧规律,通过半溶剂法制备了一种火药力高达1240J/g的新型高能叠氮硝胺发射药(ADR),采用高压密闭爆发器和30mm高压模拟试验装置,分别研究了不同温度下ADR发射药定容高压燃烧性能和装填密度、温度以及石墨光泽处理对ADR发射药膛内高压燃烧稳定性的影响。结果表明,不同温度条件下(-40、20和50℃)ADR发射药静态及动态燃烧性能稳定性良好,燃烧过程无异常;随着温度的增加,ADR发射药点火性能提高,增加了膛内燃烧稳定性;装填密度0.48~0.64g/cm³范围内,随着装填密度的增加,ADR发射药膛内压力波强度逐渐增加,但增长幅度减小;对发射药进行石墨光泽处理,增加了ADR发射药起始缓燃效果,使不同温度下膛内压力波强度明显降低;与RGD7发射药相比,ADR发射药火药力较高,爆温较低,发射装药膛内高压燃烧稳定性相当,在高膛压环境中应用前景较好。     

30%液碱生产中盐泥处理工艺的改进

介绍了30％液碱生产过程中盐泥处理工艺的改造过程。     

30CrMnSiNi2A钢的动态屈服强度研究

采用分离式Hopkinson压杆技术,对经过不同热处理的低合金超高强度钢—30CrMnSiNi2A钢的动态力学行为进行研究。试样经过正火热处理、860℃淬火+600℃回火、860℃淬火+200℃回火热处理3种热处理制度后,经过动态力学实验得出:30CrMnSiNi2A钢在不同应变率下的屈服强度值随应变率增加而增大,呈现一定的应变率敏感性;在860℃淬火+200℃回火状态下,表现为一定的回火脆性;在860℃淬火+600℃回火状态时表现为优良的综合力学性能。     

弓形虫P30蛋白抗原表位的克隆表达及纯化鉴定

目的构建表达P30蛋白抗原表位的重组质粒及工程菌,获得纯化的P30蛋白抗原表位,用于检测弓形虫特异性抗体。方法采用PCR技术,设计一对引物(P30P3、P30P4),从弓形虫基因组DNA中扩增出编码P30蛋白抗原表位的基因片段,与载体pET28a(+)连接,重组质粒转化大肠杆菌BL21(DE3),经IPTG诱导后进行SDSPAGE分析。用离子交换纯化表达的P30抗原表位,用ELISA鉴定其抗原性。结果表达的P30蛋白抗原表位以包涵体形式存在,纯化的P30蛋白抗原表位片段有较好的抗原性,可用于检测弓形虫抗体。结论已成功构建了高表达P30蛋白的工程菌,为研制弓形虫抗体检测试剂或疫苗奠定了基础。     

EFFECT OF MICROSTRUCTURE AND ELEMENT DISTRIBUTION ON EROSION－CORROSION BEHAVIOUR OF AN IRON BASE CAST ALLOY

用扫描电镜、Ｘ射线衍射、电子探针等手段测定及分析了Ｆｅ基铸造合金Ｃｒ３０Ｎｉ１７Ｍｏ２Ｃｕ以不同速度凝固后的显微组织和主要合金元素分布，在含固相颗粒的强酸性双相流介质中测定了冲刷腐蚀性能。结果表明，快凝铸态组织耐冲刷腐蚀性能最佳，慢凝铸态次之；时效热处理虽能提高硬度，但抗冲刷腐蚀性能反而下降。