关键词： 古代汉语教学   假借字   本有其字   通假字   古汉语教学   本字   笼统   定义  

摘要： 通假字是古汉语教学和研究的一个难点,近年来学者们对通假字的研究也逐渐深入,但仍有一些学者认为本有其字的假借就是通假,一部分学者认为通假字与其本字的意义毫无联系,这些认识都不利于对古代汉语教学和研究的开展。因此明确通假字的定义,掌握通假字的性质特点是尤为重要的。一、通假的定义学术界对通假的认识存在着不同的见解,主要有以下几类:(一)认为"通假"是"本有其字"的假借笼统认为"本有其字"的假借是通假,不明确假借字的范围。

关键词： 青霉素类抗生素   成本效益原则   假阴性反应   青霉素过敏   假阳性反应   半合成青霉素   抗原决定簇   皮肤试验  

摘要： 皮肤试验是诊断青霉素类抗生素过敏的重要方法之一,但青霉素过敏诊断中,皮试试剂需包含青霉素主要抗原决定簇、次要抗原决定簇、青霉素G、以及半合成青霉素,才能尽可能提高敏感度;而仅使用某一种试剂,检测敏感度非常有限。皮试试剂中还需要包括阴性对照(生理盐水)以排除假阳性反应,阳性对照(组胺)以排除假阴性反应。因此青霉素给药前,对无可疑青霉素过敏史的患者进行常规皮试不符合成本效益原则,且未经变态反应专业培训的人员无法胜任皮试操作及结果解读。

关键词： 语言接触   历史语言学   语言变异   语言史   国外研究现状   多语制   :英语  

摘要： Multilingual Practices in Language History:English and Beyond为德古意特出版社“语言接触与双语实践”(Language Contact and Bilingualism)系列专著的第十五册。第一作者为芬兰坦佩雷大学的P ivi Pahta,多年来一直从事语言变异、语言接触、历史语言学以及多语制研究。该书以历史上的多语实践为研究对象,多为迄今尚未得到学界足够重视的文本,涉及不同文体、不同时期和不同地区。本文将简述并评介该书的主要内容,让读者了解国外研究现状并根据我国国情开展中国特色的多语研究。

关键词： natural gas   acoustic velocity   heat capacity ratio   avo   seismic analysis   deep-water petroleum   heat energy generation   storage   transfer   hydrates   coal bed methane   heavy oil   oil sands   tight gas   natural gas technology   oil   gas reservoirs   petroleum engineering   wells-injection   oil   gas   geothermal  

摘要： We investigate three formulations for computing acoustic velocity of natural gas and derive an equation for the heat capacity ratio, which plays a central role in these formulations. The first formulation is a compilation of fundamental equations available in the engineering literature, referred to as the DASH formulation. The second formulation is a development from the first, in which we use the derived equation for the heat capacity ratio (modified DASH). The third formulation is a mainstream method implemented in Geoscience (BW formulation). All three formulations stem from virial Equations of State that take preponderance in the exploration stage, when the detailed fluid composition is unknown and compositional methods are frequently inapplicable. We test the formulations on an extensive experimental data set of acoustic velocity of natural gases and compare the resulting accuracies. Both DASH and modified DASH formulations provide significantly higher accuracy when compared to the BW formulation. Additionally, the modified DASH, as we derive in this work, has the highest accuracy at pressures above 7000 psi, a condition typically encountered in the Brazilian pre-salt reservoirs. In a final step, we investigate how these different formulations and corresponding accuracies in velocity computation may affect seismic modeling, using a single interface model between a dense gas reservoir and a sealing rock. A direct comparison of amplitude versus offset modeling using our modified DASH formulation and the BW formulation shows up to 50% difference in amplitude calculation in a sensitivity exercise, especially at the longer offsets and higher pressures.

关键词： Fischer-tropsch   Droplet diameter   Velocity   Concentration distribution  

摘要： Aviation alternative fuels are becoming the inevitable choice of aviation industry under the background of global environmental protection. Fuel droplets with small size and high velocity can lead to an efficient combustion and reduce pollutant emission. A numerical investigation of Fischer-tropsch (FT) alternative jet fuel injected from a pressure swirl atomizer is conducted by using Ansys Fluent where a 3-D geometry of the atomizer nozzle and the external spray domain are prepared in Solidwork. Phase Dopler Anemometry (PDA) measurements on Chinese jet fuel (RP-3) and FT fuel are conveyed to validate the spray characteristics collected numerically. Small droplets are generally located inside the spray core region and in the spray periphery but can also be found in the central region at high pressure. The droplets with the highest SMD are being formed in the outer spray region and both FT and RP-3 show a higher droplets velocity in the nozzle exit region. It has been observed that the SMD decreases with increase in injection pressure and that using the SSD model provide results in agreement with the experimental ones. It is also proved that computational simulation performed on alternative fuel by using an unsteady RANS in the Euler-Lagrangian frame can precisely predict the spray atomization process. (c) 2021 Published by Elsevier Ltd.

关键词： 西夏文   世俗文献   通假字  

摘要： 学者研究已经证实西夏文佛典文献中存在通假现象。通过调查可知,西夏文世俗文献中也有通假字,分布于民间文书、夏译汉籍、国家法典等,使用较为频繁。辨析西夏文通假字,对于重新审视、考证世俗文献释读过程中存疑的词义具有重要意义。

关键词： Spray characteristics   Near field   Bio-jet fuel C-3   Flow blurring injector   Shadowgraph   PIV  

摘要： Efficient and clean combustion of jet fuels highly relies on their spray characteristics. Prior studies have shown that the flow blurring (FB) injector developed in the recent decade could generate fine sprays at the injector's immediate exit rather than a jet core of conventional fuel nozzles. The current study experimentally investigates spray characteristics of a viscous renewable jet fuel, C-3, using FB atomization. The effect of Air-to-Liquid Mass Ratio (ALR) across the injector is investigated. Results show the stable and fine FB sprays are obtained at ALRs of 1.0-2.5 for the high viscosity fuel. Cumulative droplet size distribution and Sauter Mean Diameter (SMD) obtained using high-spatial-resolution Shadowgraph imaging technique (SIT) reveal the fine atomization is rapidly accomplished at approximate 1.67-2.67 D downstream the injector exit with the diameter D of 1.5 mm for all the ALRs. The spray velocity measurements using Particle Image Velocimetry (PIV), the SMD by SIT, and Weber number estimate consistently show rigorous secondary droplet disintegration at spray periphery. Estimation of Weber and Ohnesorge numbers suggests that oscillatory deformation is dominant at the spray center across the effective ALRs, and droplets at higher ALR and spray periphery experience more vibrant breakup modes such as bag, bag-stamen or multi-mode. The results quantitatively demonstrate that the FB injector can generate ultrafine and stable sprays for the viscous bio-jet fuel C-3, suggesting the potential use of this fuel injector for renewable jet fuels regardless of high viscosity to achieve stable, complete, and premixed combustion with ultralow emissions.

关键词： 异体字   类似偏旁   互用   字图  

摘要： 异体字中很多都是通过把正字的偏旁改换为另一个偏旁产生的,其中很多与原来的偏旁相比,字音或字义完全没有关联,只是字形类似。这些换旁异体字的正字,有时并不容易确定。整理字形相似、相互使用的替换关系,对考察异体字的正字有很大的帮助。本文为此汇集了这种类型的异体字,并分析和整理了它们之间的关系。

关键词： Root-knot nematode   Chemical pest control   Organic nematicide   Fluensulfone   Oxamyl   Abamectin  

摘要： Root-knot nematodes (Meloidogyne spp.) are considered as the most serious nematode pest in the world and have been reported to cause up to 57-67 % crop yield losses in untreated conditions in Australia. Chemical control has been the most popular method to manage root-knot nematodes due to its high efficacy. However, 'fenamiphos' the most widely used active ingredient in nematicides, has recently been reviewed by the Australian Pesticides and Veterinary Medicines Authority and subsequently has been recommended for removal from the commercial market in Australia due to concerns about its potential to contribute to adverse environmental and human health impacts. Due to this pressure of nematicide restrictions, alternative chemical and organic formulations were assessed against root-knot nematodes in a sweetpotato field trial comparing with untreated control and chemical control 'oxamyl' (currently registered chemical for sweetpotato). Fluensulfone significantly reduced soil root-knot nematode numbers compared to other treatments, giving the highest marketable yield in this trial. Abamectin did not give significant root-knot nematode control or damage reduction. Organic nematicide treatments (garlic formulation and nutrient and microbial formulation) did not show a significant reduction of soil root-knot nematode numbers and root damage. No significant effect of nematicides was found on non-target organisms (soil bacteria and nematodes) at 24 weeks after planting.

摘要： In pancreatic β cells, intracellular Ca2+ is essential for insulin biosynthesis. Ryanodine receptors (Ryrs) mediate Ca2+ mobilization from the endoplasmic reticulum. Previously we found that type 2 Ryr (Ryr2; originally called cardiac-type) of three isoforms from separate genes was expressed in pancreatic β cells and that Ryr2 mRNA expressed in the pancreatic β cells was deficient in the region of exon 75, unlike that expressed in the heart. This alternative splicing occurred tissue-specifically, which is presumably due to a unique splice donor site "gg" in intron 75 of Ryr2 gene. In order to clarify the role of the tissue-specific splice variant of Ryr2 on insulin biosynthesis, we constructed the homozygous genome-modified pancreatic β cells which express cardiac RYR2 by changing the splice donor "gg" of RYR2 gene to "gt" in human 1.1B4 pancreatic β cells using the CRISPR/Cas9 system. Insulin content in the culture medium and insulin mRNA level were measured by ELISA and real-time RT-PCR, respectively. The results showed that both insulin and insulin mRNA levels were significantly lower in the genome-modified cells than those in parental 1.1B4 cells. We examined the effect of complementation of Ryr2 by introducing the rat cardiac-type or islet-type Ryr2 expression vector into each cell. Real-time RT-PCR analysis showed that the expression of insulin mRNA was significantly increased in the cells transfected with the islet-type Ryr2 expression vector, whereas that in the cells transfected with the cardiac-type Ryr2 expression vector was not increased. Furthermore, the result of luciferase assay showed that the promoter activity of insulin gene was not decreased in the genome-modified cells as compared with the parental 1.1B4 cells. In conclusion, those results indicate that exon 75-deficient Ryr2 could be important in the post-transcriptional step of insulin biosynthesis via Ca2+ signaling in pancreatic β cells.