Study on the Removal of Nitrogen Oxide from Diesel Engine Exhaust by Non-thermal Plasma Facilitated with Conventional Denitrification Process

氮氧化物（NOx）是重要的大气污染物之一，有N2O、NO、N2O3、NO2、N2O5等多种形态，柴油器尾气中的NOx主要以NO和NO2的形态存在。大气中的NOx主要来源于燃煤电厂、水泥行业和内燃机的废气排放，会造成光化学烟雾、酸雨等大气污染现象，刺激人的眼、鼻、喉、肺，危害人类健康。作为内燃机中的主要机型，柴油发动机广泛应用于发电机组、工农业机械和交通运输等领域，产生的废气是大气中NOx的重要来源之一。目前用于降低柴油机尾气中NOx含量的技术主要是燃油高压喷射、增压中冷、废气再循环等机内控制技术，对NOx的脱除效果有限。机外控制技术主要包括选择性催化还原、NOx存储还原技术等，但也各有其应用局...Nitrogen oxides (NOx) is one of the most important air pollutants, including N2O, NO, N2O3, NO2, N2O5 and so on, almost 98% of the NOx exist in the form of NO and NO2. NOx mainly resource from coal-fired power plants, cement industry and internal combustion engine emissions, which may cause photochemical smoke, acid rain and other air pollution phenomenon, to stimulate people's eyes, nose, throat,...学位：工学硕士院系专业：环境与生态学院_环境工程学号：3312014115171

Y型聚乙二醇干扰素琢-2b注射液治疗HCV基因2/3型慢性丙型肝炎患者疗效和安全性的多中心随机对照试验研究

目的以标准剂量的聚乙二醇干扰素(Peg IFN)α-2a联合利巴韦林作为阳性对照,评价新型试验药物Y型Peg IFNα-2b注射液联合利巴韦林治疗2型/3型慢性丙型肝炎(CHC)患者的疗效和安全性。方法采用多中心、随机开放、阳性药对照的Ⅲ期临床试验,筛选符合要求的2型/3型CHC患者,按照2:1的比例随机分配到Y型Peg IFNα-2b组和Peg IFNα-2a组,同时口服利巴韦林,疗程24 w,停药随访24 w。采用Abbott Real Time HCV Genotype II检测HCV基因型,采用Cobas Taq Man实时定量PCR法检测血清HCV RNA水平。详细记录不良事件。主要疗效指标为持续病毒学应答(SVR),并进行非劣效检验。结果本试验实际入组2型/3型CHC患者255例,实际治疗241例。全分析集(FAS)数据显示,158例试验组和83例对照组患者SVR分别为85.4%(95%CI 79.94%~90.94%)和79.5%(95%CI 70.84%~88.20%,P=0.2402);对符合方案分析集(PPS)人群分析显示,试验组和对照组患者SVR分别为87.9%(95%CI 82.45%~93.27%)和85.9%(95%CI 77.82%~94.01%,P=0.7060),率差的95%可置信区间均符合非劣效标准;对PPS人群分析显示,85.8%受试者获得了早期病毒学应答(RVR),RVR的阳性预测值为90.1%;试验组和对照组不良事件发生率相似,分别为95.6%和95.2%,严重不良事件发生率分别为3.8%和3.6%。结论应用Peg IFNα联合利巴韦林治疗2型/3型CHC患者,新型试验药物Y型Peg IFNα-2b具有与对照药物Peg IFNα-2a相似的疗效和安全性。国家科技部“十二五”重大专项(编号:2012ZX10002-003)；“重大新药创制”十二五科技重大专项(编号:2012ZX09303019)

超高周疲劳裂纹萌生和初始扩展的机理与模型

提出了高强材料超高周疲劳值得关注的若干关键问题,探讨了高强钢超高周疲劳裂纹起源和初始扩展的特征与机理。文中通过大量实验结果,显示了"鱼眼"和"细晶区"尺寸随疲劳寿命的变化趋势,表明"鱼眼"和"细晶区"的应力强度因子值不随疲劳寿命变化而是基本

应力比对疲劳裂纹扩展速率和疲劳强度的影响

研究了不同应力比R下近门槛区裂纹扩展速率之间的关系,表明应力比R对近门槛区裂纹扩展速率和裂纹稳定扩展区裂纹扩展速率的影响可以表示成统一的形式,即da/dN=C(△K_(eff)-△K_(c th,o)~m,其中△K_(eff)=△K(1-R)~(-α)或△K_(eff)=(K_(max)~α(△K~+)~(1-α),△K_(c th,0)为裂纹萌生门槛值,C,m,α为与材料有关常数。进而,推导了应力比(平均应力)对疲劳强度的影响关系,并与文献中的实验结果(包含

Multiaxial fatigue life prediction by equivalent energy-based critical plane damage parameter under variable amplitude loading

A new path-independent multiaxial fatigue damage parameter sigma n*$${\sigma}_n{\ast }$$, which is defined as the largest normal stress range between adjacent turning points of the maximum shear stress on the critical plane, is proposed to describe multiaxial fatigue damage. By combining the maximum normal stress sigma n,max$${\sigma}_{n,\max }$$ or the largest normal stress range sigma n*$${\sigma}_n{\ast }$$ with the maximum shear stress range on the critical plane, two axial equivalent stress modification factors, keq sigma$${k}_{\mathrm{eq}}{\sigma }$$ and keq sigma*$${k}_{\mathrm{eq}}{\sigma \ast }$$, are proposed, which can account for the influence of non-proportional additional hardening. The sensitivity of the proposed axial equivalent stress modification factors to multiaxial variable amplitude loading sequences is analyzed. Furthermore, two new multiaxial fatigue damage models based on the axial equivalent stress modification factors are proposed to estimate fatigue life. The applicability of the presented methodology was verified by the experimental data of En15R steel and 7050-T7451 aluminum alloy, and the results showed that the predicted fatigue lifetimes agree well with the experimental data under variable amplitude multiaxial loading

Very high cycle fatigue for GCr15 steel with smooth and hole-defect specimens

Very high cycle fatigue (VHCF) properties of a low temperature tempering bearing steel GCr15 with smooth and hole-defect specimens are studied by employing a rotary bending test machine with frequency of 52.5 Hz. Both smooth and hole-defect specimens break in VHCF regime with some difference in fatigue crack initiation. For smooth specimens, a fine granular area (FGA) is observed near the grain boundary in the fracture surface of the specimens broken after 10^7 cycles. But no FGA is observed in the hole-defect specimens broken in VHCF regime, and the VHCF crack does not initiate from the small hole at the surface as it does at low or high cycle fatigue regime. Internal stress is employed to explain the VHCF behavior of these two types of specimens. At last, an advanced dislocation model based on Tanaka and Mura model is proposed to illustrate the internal stress process and to predict fatigue crack initiation life with FGA observed in the fracture region.Very high cycle fatigue (VHCF) properties of a low temperature tempering bearing steel GCr15 with smooth and hole-defect specimens are studied by employing a rotary bending test machine with frequency of 52.5 Hz. Both smooth and hole-defect specimens break in VHCF regime with some difference in fatigue crack initiation. For smooth specimens, a fine granular area (FGA) is observed near the grain boundary in the fracture surface of the specimens broken after 10^7 cycles. But no FGA is observed in the hole-defect specimens broken in VHCF regime, and the VHCF crack does not initiate from the small hole at the surface as it does at low or high cycle fatigue regime. Internal stress is employed to explain the VHCF behavior of these two types of specimens. At last, an advanced dislocation model based on Tanaka and Mura model is proposed to illustrate the internal stress process and to predict fatigue crack initiation life with FGA observed in the fracture region

Reliability analysis of very-high-cycle fatigue crack initiation for a high strength steel

A high carbon chromium steel was tempered at 150℃,180℃,and 300℃to form three groups of specimens,and veryhigh -cycle fatigue(VHCF) tests were performed via rotating bending to investigate scatter properties of S-N curves. Experimental results show an increasing tendency of life scatter with the i..