Multi-objective optimization design method of the high-speed train head

With the continuous improvement of the train speed, the dynamic environment of trains turns out to be aerodynamic domination. Solving the aerodynamic problems has become one of the key factors of the high-speed train head design. Given that the aerodynamic drag is a significant factor that restrains train speed and energy conservation, reducing the aerodynamic drag is thus an important consideration of the high-speed train head design. However, the reduction of the aerodynamic drag may increase other aerodynamic forces （moments）, possibly deteriorating the operational safety of the train. The multi-objective optimization design method of the high-speed train head was proposed in this paper, and the aerodynamic drag and load reduction factor were set to be optimization objectives. The automatic multi-objective optimization design of the high-speed train head can be achieved by integrating a series of procedures into the multi-objective optimization algorithm, such as the establishment of 3D parametric model, the aerodynamic mesh generation, the calculation of the flow field around the train, and the vehicle system dynamics. The correlation between the optimization objectives and optimization variables was analyzed to obtain the most important optimization variables, and a further analysis of the nonlinear relationship between the key optimization variables and the optimization objec- tives was obtained. After optimization, the aerodynamic drag of optimized train was reduced by up to 4.15%, and the load re- duction factor was reduced by up to 1.72%.     

火电燃煤锅炉NOx生成机理与燃烧优化技术的研究

煤燃烧的污染排放是我国主要大气污染源之一。分析了燃煤锅炉中NOx生成的机理,介绍了减少NOx生成和排放的工业技术,在对国内外燃煤锅炉燃烧优化技术研究现状综述的基础上,对前沿现代技术应用于燃烧优化控制的发展趋势进行了展望。     

强化科研素质,培养创新人才 --体育院系加强科研教育是培养创新人才的重要途径

创新是我国体育事业兴旺发达的不竭动力．创新需要创新人才，体育院系进行科研教育是造就高层次创新人才的根本途径．调查发现，我国当代体育大学生几乎没有受到科研的训练，无科研意识，也无科研能力．培养体育大学生科研素质的具体对策是：更新体育教育思想，强化基础理论学习，设置相关课程，撰写论文的次数要增如，给大学生参如科研实践的机会，学报开设学生论文专栏，营造科研文化氖围．     

旋流燃烧室内流场PIV测量误差修正方法的研究

对微型燃气轮机旋流燃烧室内湍流流动PIV测量中产生的非轴对称性误差的原因进行了分析,提出了基于CFD技术的旋流燃烧室内湍流流动PIV测量误差的修正方法,将修正后的实验数据与数值计算结果进行了比较,结果表明,该修正方法可以有效地减小旋流燃烧室内湍流流动PIV测量中产生的非轴对称性的误差。     

On the Pronunciation of ELT Teachers in China as a Source for Language Contact and Language Input

在外语教学中,教师发挥着越来越重要的作用.因此,对外语教师的要求也随之提高.这一点已经得到了证实.作为语言沟通和语言输入的来源,外语教师的标准发音给教学带来了很大作用.因此,应当对外语教师进行培训,然后挑选合格者任职.这样,才能教会学生标准的语音语调,促进语言的正确运用.     

连续挤出微孔发泡过程中温度对泡孔结构的影响

微孔物理发泡因其本身和制品的诸多优点,已越来越多地受到人们的重视,研究重点也逐渐由对发泡成核机理等的研究转向对加工过程中各种影响因素的研究,以求实现对物质发泡结构（泡孔尺寸、泡孔密度、泡孔形态）的更好控制。熔体温度、熔体压力（压力降或压力降速率）、熔体流速以及气体在体系中的浓度是连续挤出发泡过程中的几个关键参数,该文主要探讨了温度对微孔物理发泡塑料泡孔结构的影响,从理论上分析了聚合物熔体温度对气泡成核及长大的影响,结果与前人实验一致;同时,重点分析探讨了连续挤出发泡过程中发泡温度对气泡成核、泡孔尺寸和泡孔密度、泡孔形态等的影响。     

师专体育专业《人体解剖学》教学模式的实验分析

根据解剖学教学特点 ,采用系列教学模式 ,既注重学生对基础知识的掌握 ,又注重对学生能力的培养 ,有助于教学质量的提高     

The Poor Get Richer: Heterogeneity in the Efficacy of a School-Level Intervention for Academic Language

We investigate the impact of a relatively brief cross-curricular intervention, Word Generation, on middle school students' development of taught academic vocabulary. Students (n = 8382) in forty-four middle schools in three urban districts were randomly assigned to treatment or control conditions. Treatment teachers implemented the program with minimal support and varying levels of commitment. Students in treatment schools scored almost a point higher on the curriculum-based vocabulary posttests than those in control schools (Hedges's g = 0.094, p < 0.05). Though there was no main treatment effect on the standardized measures of students' general vocabulary knowledge or reading comprehension, baseline-by-treatment interactions at the school and student level acted to attenuate the Matthew Effect in reading and vocabulary growth.     

Adaptive capacity in the Pacific region: a study of continuous professional development for in-service teachers in Kiribati

This study of I-Kiribati secondary school teachers used a project-based approach to investigate the notions of school-based and collaborative learning as a suitable model for in-service teacher continuous professional development (CPD). The design and methodology adopted by the study framed the argument that since collaborative behavior is integral in Kiribati and Pacific community daily life it could be a suitably applied in the workplace to promote effective learning. At the same time the study was designed to investigate a system of learning for teachers in Kiribati that would address their needs, in particular being school-based. The study revealed that cultural influences in Kiribati such as: the role of leaders, respect for elders and secret knowledge have a strong influence on teacher behavior both inside and outside the classroom. The recommendations concur with research literature that suggests developing effective policy and practices in the Pacific region must be driven by and strongly reflect cultural practices, values and beliefs. Importantly, the notion that some cultural practices may conflict when applied in different settings provides an added dimension to the body of literature.     

Expression of a bee venom phospholipase A2 from Apis cerana cerana in the baculovirus-insect cell

Bee venom phospholipase A2(BvPLA2) is a lipolytic enzyme that catalyzes the hydrolysis of the sn-2 acyl bond of glycerophospholipids to liberate free fatty acids and lysophospholipids.In this work,a new BvPLA2(AccPLA2) gene from the Chinese honeybee(Apis cerana cerana) venom glands was inserted into bacmid to construct a recombinant transfer vector.Tn-5B-4(Tn) cells were transfected with the recombinant bacmid DNA for expression.Sodium dodecylsulfate-polyacrylamide gel electrophoresis(SDS-PAGE) analysis revealed a double band with molecular weights of 16 and 18 kDa.Products of hexahistidine AccPLA2 fusion protein accumulated up to 5.32% of the total cellular proteins.The AccPLA2 fusion protein was cross reactive with the anti-AmPLA2(BvPLA2 of the European honeybee,Apis mellifera) polyclonal serum.The reaction resulted in a double glycosylation band,which agrees with the band generated by the native AmPLA2 in Western blot analysis.The PLA2 activity of the total extracted cellular protein in the hydrolyzing egg yolk is about 3.16 μmol/(min·mg).In summary,the recombinant AccPLA2 protein,a native BvPLA2-like structure with corresponding biological activities,can be glycosylated in Tn cells.These findings provided fundamental knowledge for potential genetic engineering to produce AccPLA2 in the pharmaceutical industry.     

水土保持是山丘区防治洪水灾害的根本措施——以黄冈麻城调查研究为例

麻城山丘区面积大,水土流失严重,洪水灾害频发。一段时间内,人们不合理地经济活动,破坏了自然植被,导致境内植被覆盖率降低,土地失去植被的庇护,水土流失加剧,造成洪水径流量和洪峰流量加大,加重了洪水灾害。二十多年的水土保持工作实践表明：以小流域为单元的水土保持综合治理工作,通过在流域内实施工程措施、生物措施和农耕措施相结合,坚持山、水、林、田、路统一规划,拦、截、灌、蓄、排优化配置,集中连片,规模治理,防范减灾效益显著。事实证明,水土保持工作是山丘区防治洪水灾害的根本措施。     

XRCC1 Arg399Gln and clinical outcome of platinum-based treatment for advanced non-small cell lung cancer: a meta-analysis in 17 studies

Objective: XRCC1 polymorphism is a research hotpot in individual treatment for non-small cell lung cancer (NSCLC). To obtain the association between XRCC1 polymorphism and clinical outcome of platinum-based treatment for NSCLC, a meta-analysis was conducted. Methods: Databases including PubMed, Embase, Cochrane, and Chinese National Knowledge Infrastructure (CNKI) were searched for publications that met the inclusion criteria. A fixed effect model was used to estimate pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) for the association between XRCC1 Arg399Gln and response or survival of platinum-based treatment for advanced NSCLC. A chi-squared-based Q-test was used to test the heterogeneity hypothesis. Egger’s test was used to check publication bias. Results: Seventeen published case-control studies that focus on the association between XRCC1 Arg399Gln and response or survival of platinum-based treatment for advanced NSCLC in 2 256 subjects were included in this meta-analysis, of whom 522 were AA genotypes (23.2% frequency), 916 AG genotypes (40.6% frequency), and 818 GG genotypes (36.2% frequency). The overall response rate (ORR) was 45.2% (110/243) for AA genotype patients, 29.9% for AG genotype (73/244), and 30.7% for GG genotype (124/403). The heterogeneity test did not show any heterogeneity and the Egger’s test did not reveal an obvious publication bias among the included studies. The meta-analysis indicated that AA genotype patients presented higher response rates toward platinum drug treatment compared with G model (GG+GA) patients (GG vs. AA model: OR=0.489, 95% CI 0.266–0.900, P=0.021; AG vs. AA model: OR=0.608, 95% CI 0.392–0.941, P=0.026; GA+AA vs. GG model: OR=1.259, 95% CI 0.931–1.701, P=0.135; GG+GA vs. AA model: OR=0.455, 95% CI 0.313–0.663, P=0.0001). However, no evidence validates XRCC1 associates with the survival following platinum drug therapy. Conclusions: Our meta-analysis suggested that XRCC1 Arg399Gln is related with the sensitivity of NSCLC patients to platinum-based treatment. AA genotype patients present more desirable curative effectiveness compared with other patients.