基于信息检索课的大学生信息检索行为调查研究

信息检索课程的系统化讲授,对于大学生优化信息检索行为,提高信息检索使用效率具有不容忽视的教学辅助作用.立足问卷调查形成的一系列相关数据,探讨大学生信息检索行为存在问题,最终在课程教学中提出优化大学生信息检索的对策:明确信息检索目的,提升实施效果;有效提升检索行为实施频率,增强综合质量;使得信息获取多元发展,优化成效凸显...     

天然气加热炉的腐蚀原因及防护对策

天然气加热炉的腐蚀是一个普遍现象.本文从引起腐蚀的因素人手,详细剖析腐蚀发生的原因,提出监测和治理相结合的方法,系统地介绍了几种常用的防腐技术,包括添加缓蚀剂、使用耐腐蚀材料、界面涂层、电化学防腐及其它相关防腐技术.     

Production of granola breakfast cereal by fluidised bed granulation

In the fluidised bed granulation process the effect of nozzle air pressure and binder spray rate on key aggregate quality attributes were studied. The experimental results show that a decrease in nozzle air pressure leads to larger mean granule size. The combination of lowest nozzle air pressure and lowest binder spray rate results in granules with the highest levels of hardness and crispness. The combination of low nozzle air pressure and low binder spray rate results in the least distribution span. Granola hardness was affected by nozzle air pressure. Nozzle air pressure and binder spray rate did not have significant effect on crispness.     

Deoxycholate‐Based Glycosides (DCGs) for Membrane Protein Stabilisation

Detergents are an absolute requirement for studying the structure of membrane proteins. However, many conventional detergents fail to stabilise denaturation‐sensitive membrane proteins, such as eukaryotic proteins and membrane protein complexes. New amphipathic agents with enhanced efficacy in stabilising membrane proteins will be helpful in overcoming the barriers to studying membrane protein structures. We have prepared a number of deoxycholate‐based amphiphiles with carbohydrate head groups, designated deoxycholate‐based glycosides (DCGs). These DCGs are the hydrophilic variants of previously reported deoxycholate‐based N‐oxides (DCAOs). Membrane proteins in these agents, particularly the branched diglucoside‐bearing amphiphiles DCG‐1 and DCG‐2, displayed favourable behaviour compared to previously reported parent compounds (DCAOs) and conventional detergents (LDAO and DDM). Given their excellent properties, these agents should have significant potential for membrane protein studies.     

布洛芬热分解及其动力学研究

通过布洛芬(ibuprofen)的热分解及其动力学研究,运用简单的热分解动力学方法进行计算分析,求出相关的活化能,指前因子和动力学参数。将布洛芬每个温度范围下的热分解过程分为3个阶段分别进行分析计算,发现每个阶段都满足一级反应方程。从而算出布洛芬热分解过程的活化能,指前因子和相关系数。通过对布洛芬热分解过程的研究,及对布洛芬TG和DTG曲线的研究,得出布洛芬在热分解过程中分为3个阶段,分别进行脱水,C-C键断裂和分子键断裂。并且随着升温速率的提高,布洛芬失重速率会逐渐趋向于温度升高的方向发展,即温度升高,布洛芬最大失重速率越大。     

基于丙二酰胺结构不对称双子表面活性剂的合成及性能

在丙酮溶剂中,氯乙酸十六醇酯（I）与过量的二（3-二甲氨基丙基）丙二酰胺反应,用乙醚洗涤后,再与溴代十六烷季铵盐化,经丙酮-乙腈混合溶剂重结晶,得到了一种新型基于丙二酰胺结构的不对称Gemini表面活性剂（命名为16．18）,收率为51．2％（以I计）,纯度为99．6％。采用IR、1HNMR表征了结构,电导率法测定其CMC值为7．91×10^-5mol／L,滴体积法测定其YCMC为37．87mN／m,其Krafft点小于0℃,研究了其乳化、泡沫性能。     

Clinical and Genetic Re-Evaluation of Inherited Retinal Degeneration Pedigrees following Initial Negative Findings on Panel-Based Next Generation Sequencing

Although rare, inherited retinal degenerations (IRDs) are the most common reason for blind registration in the working age population. They are highly genetically heterogeneous (>300 known genetic loci), and confirmation of a molecular diagnosis is a prerequisite for many therapeutic clinical trials and approved treatments. First-tier genetic testing of IRDs with panel-based next-generation sequencing (pNGS) has a diagnostic yield of ≈70–80%, leaving the remaining more challenging cases to be resolved by second-tier testing methods. This study describes the phenotypic reassessment of patients with a negative result from first-tier pNGS and the rationale, outcomes, and cost of second-tier genetic testing approaches. Removing non-IRD cases from consideration and utilizing case-appropriate second-tier genetic testing techniques, we genetically resolved 56% of previously unresolved pedigrees, bringing the overall resolve rate to 92% (388/423). At present, pNGS remains the most cost-effective first-tier approach for the molecular assessment of diverse IRD populations Second-tier genetic testing should be guided by clinical (i.e., reassessment, multimodal imaging, electrophysiology), and genetic (i.e., single alleles in autosomal recessive disease) indications to achieve a genetic diagnosis in the most cost-effective manner.     

Making programme learning outcomes explicit for students of process and chemical engineering

There is a global shift in education from solely content-driven teaching to teaching that takes learning outcomes into account. This movement underpins much of the educational reform in the area of engineering education. Programme learning outcomes for degrees in engineering education are more commonplace as more and more professional accrediting bodies require fulfillment or compliance with prescribed learning outcomes. However, the students may not be presented with these learning outcomes as they are often “hidden” in documentation submitted by institutions for accreditation purposes and hence may not be divulged to students. Undergraduate students (2006–2008) taking the BE degree programme in Process & Chemical Engineering at UCC were first surveyed to assess their level of knowledge of the learning outcomes concept and of the degree programme learning outcomes. The contents of two documents used in applications for accreditation by professional accreditation bodies as well as professional Institution guidelines were reviewed to formulate the degree programme learning outcomes which were presented to the students. These students were then surveyed after the presentation. The results of the questionnaire completed by students demonstrated a major improvement in their knowledge of both the concept of learning outcomes and also of the degree programme learning outcomes. It also showed that the students found the session to be of overall beneficial value.     

化学合成制药综合废水的处理

本文介绍了化学合成制药废水的处理工艺、原理和运行效果,该工艺处理后的污水完全达到国家规定的污水排放标准。     

Chip Formation, Acoustic Emission and Surface White Layers in Hard Machining

In hard machining, sawtooth chip formation is due to initiation of adiabatic shear within the lower region of the primary shear zone. Catastrophic failure within the upper region of the shear zone occurs through either of two different mechanisms and results in the rapid release of elastic strain energy. This periodic release of strain energy is the dominant source of acoustic emission during sawtooth chip formation. In addition to adiabatic shearing in the primary and secondary shear zones, there is evidence to suggest that it occurs in the tertiary shear zone also; namely the surface white layer.