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901.
综述了离子液体萃取脱硫、萃取氧化脱硫以及催化氧化脱硫技术的国内外研究进展;阐述了离子液体在不同脱硫体系中的作用及再生问题;论述了离子液体催化氧化脱硫技术的优点,如:反应条件温和,脱硫效率高,操作简单,最有发展前景,可以作为加氢脱硫的补充,实现燃油的深度脱硫;并分析了离子液体脱硫技术存在的问题及其工业化应用前景.  相似文献   
902.
李春密 《物理实验》2002,22(10):25-29
对高中生物理实验操作能力及其品质的发展进行了探讨,得出高中生物理实验操作能力的发展呈上升趋势,年级间差异性不显著。深刻性品质、批判性品质、独创性品质的发展趋势也均呈上升趋势,灵活性品质和敏捷性品质的发展则具有波动性。  相似文献   
903.
The classical Graetz methodology is applied to investigate the thermal development of forced convection in a parallel plate channel filled by a saturated porous medium whose permeability and thermal conductivity vary in the transverse direction. It was found that there is a significant interaction between heterogeneity and thermal development.  相似文献   
904.
Shorter product life cycles in many industries impel firms to accelerate the product development process. Overlapping development stages, combined with frequent information exchange, is commonly regarded as a core technique for faster product development. However, overlapping and communication require additional resources and can be costly. We investigate the time-cost tradeoffs involved in concurrent product development to determine the optimal overlapping and communication strategies. The methodology was applied to a refrigerator development process in order to illustrate its utility.  相似文献   
905.
In recent years, liquid chromatography with tandem mass spectrometry (LC–MS/MS) has become a fundamental technology in clinical practice. In Japan, the LC–MS/MS system is used in many large hospitals. It has become popular among pharmacists and laboratory technicians. LC–MS/MS has some advantages in terms of accuracy, speed, and comprehensiveness compared to conventional automated chemical testing equipment. However, LC–MS/MS is by no means a universal method, and it is necessary to understand its characteristics before using it. In the field of therapeutic drug monitoring (TDM), there is an issue with linearity in comprehensive measurement; however, ion-abundance adjustment methods, such as in-source collision-induced dissociation, have been proposed as a solution to this problem. The development of a biomarker analysis includes search, identification, and quantification, and it is necessary to select an appropriate mass spectrometric method for each step. In this paper, we review cutting-edge technologies that can expand the performance of LC–MS/MS in the clinical field and consider current issues and future prospects.  相似文献   
906.
BackgroundPolyethylene glycol (PEG) is a polyether compound which is an excellent candidate to study possible specific interactions of protein-polymer systems at the atomic level. Such studies would be beneficial in obtaining a more thorough understanding of PEG-protein interactions and might help to explain PEG's effects on protein behavior when used as a crowder.Scope of reviewPEGs has been called double edged sword showing assorted effects on the protein due its hydrophilic, hydrophobic and amphiphatic nature. It has been observed that the stabilization of the protein due to PEGs is because of exclusion volume effect (hard core interactions) shown by the higher molecular sizes of the crowder, however there are soft (chemical) interactions also which leads to destabilization of proteins. Most of low molecular size PEGs are noticed to destabilize proteins due to soft interactions.General significanceHere, the core characteristics of the polyethylene glycols that are responsible for the various interactions with proteins and trying to delineate the behaviour of PEGs being ambiguous, are discussed. To conclude its paradox nature being a factual inert molecule or not, many different reports of PEG interactions with various proteins are clubbed together. In addition, owing to low toxicity, high polarity, high water solubility, typically unhydrolysing or undeteriorating characteristics, it has a practical significance in pharmaceutical and cosmetic industries, and in the research field on which this review shall enlighten from earlier to now.  相似文献   
907.
The Teacher Academy in the Natural Sciences (TANS) provided middle school (U.S. Grades 6–8) teachers (N = 81) with intensive professional development (PD) in chemistry, geosciences, and physics, with teachers enrolled in one scientific discipline per year. Because some teachers were retained and rotated into different disciplines, the TANS program investigated retention of science content 1–2 years beyond an instructional year. All teacher participants exhibited significant gains (p < .001), in chemistry, geosciences, or physics content, between their incoming knowledge and the 10‐day summer academy's conclusion. Chemistry and geosciences content were retained until the end of the PD year. Physics participants reported a significant loss (p < .001), although gains from teachers' incoming knowledge were still significant. When retention was measured beyond the instructional year, only the geosciences content was retained. Chemistry and physics gains were not retained, with no significant differences between incoming teachers' knowledge and content 1–2 years post instruction. Our research indicates that science content support is needed after PD programs, and importantly, that the support differs between scientific disciplines.  相似文献   
908.
Simon and colleagues propose a line of pure basic research in what is fundamentally an applied domain, mathematics education. Learning Through Activity (LTA) has all the advantages and many of the disadvantages that a pure theory in an applied domain is likely to have. The seven papers in this special issue aptly demonstrate many of the advantages. An additional advantage is that explicating the theory, as they do, raises many important questions and issues. In this commentary, I discuss some of these questions and issues concerning both, the pure research and its potential applicability to real classrooms.  相似文献   
909.
根据我国1-6次人口普查的主要统计数据,应用GSM(1,2)线性模型进行模拟,其拟合精度令人满意;同时以每十年为一普查期,应用GSM(1,1)线性模型对我国未来人口发展进行了预测,并分析了模型产生误差的原因,提出了提高模型预测精度的方法.  相似文献   
910.
针对三类本科高等数学教学质量难以提高的困难,结合作者长期从事三本高数教学的经验,分析了三本高等数学教学的几个制约因素,探索了三本高等数学教学实践中可行的新方法,给出了相关实施建议.  相似文献   
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