初中生在英语描述性写作方面的特点——以主位及主位推进模式为理论支撑

主位述位理论及主位推进模式是英语语篇分析的重要手段,因为英语是形态型语言,而主位推进模式又恰恰是从语篇的结构入手。本文分析比较了初一学生和初二学生在人物描写方面主位的异同及使用的主要主位推进模式。本文运用主述位理论比较说明了初一、初二和初三学生在人物描写方面的异同,并研究发现其主要主位推进模式类型,有助于教师们根据现有理论方法将人物描写的基本结构思想灌输给学生。     

英汉科技翻译中主位推进模式的重构

主位推进模式在篇章的生产和理解过程中起着极其重要的作用。通过比较英汉科技语篇在主位推进模式上的共性与个性，探讨于建平提出的科技语篇中五种常见的主位推进模式在英汉科技翻译过程中的重构。     

主位推进模式在大学英语写作中的应用——以大学英语四级范文为例

系统功能语言学的主位推进模式理论是通过对语句的主位和述位的划分和分析,来揭示语篇的构成规律,强调语篇的整体信息和结构。本文结合主述位理论和主位推进模式,对英语四级范文进行分析,为教师的写作教学提供了一些写作方法方面的启示。     

主位推进在旅游景点介绍英译中的作用——以马鞍山旅游景点为例

随着全球化的进一步深入,跨国旅游也随之发展起来。因此,各地的景点介绍便以多国语言对照的形式表现出来,从而使游客更加深刻地体会其中的文化底蕴。然而,景点外文介绍中存在的问题也层出不穷,影响了文化的交流和体会。本文将以马鞍山旅游景点为例,从主位推进的角度出发,以主位推进模式为分析工具,以期探究该地区景点介绍语的英译现状。     

《静夜思》汉英语篇功能对比分析

运用系统功能分析的方法，从衔接系统，主位——述位系统和信息系统以及逻辑——语义关系的角度，来探讨英汉诗歌语篇的一些功能差异，所用的例子来自于大家都熟悉的李白的诗《静夜思》及徐忠杰和Tr．W．J．B．Flether的译文。     

浅论主位结构与英语阅读教学

主位和述位系统是功能语法中语篇功能的重要组成部分。主位结构理论有助于了解和掌握有关中心内容的信息在语篇中的分布情况。主位结构的研究成果为英语阅读教学提供了有益的启示。因此,在英语阅读教学中,教师向学生传授一些这方面的知识是有必要的,它可以帮助学生在阅读时克服盲目性和困惑性,也有益于学生把握语篇发展的结构线索、脉络主题,从而提高阅读理解水平。     

从图式理论解析大学英语写作教学

语篇杂乱无章是高校学生英语写作中常见的问题之一。图式理论是互动性的理解模式,可从一个崭新的角度来解释语篇连贯。文章力图从语篇连贯角度分析并提出相应的改进策略,研究图式理论对高校英语写作教学的指导作用,提高高校学生的英语写作教学水平。     

评价理论对大学英语语篇教学的启示

评价理论在外语教学中的应用是一个新的课题，在大学英语语篇教学中具有一定的应用价值。评价理论是在功能语言学的基础上发展起来的一套研究人际意义的理论框架，关注语篇中有关协商的各种态度。以评价理论为指导，结合大学英语语篇中的部分语料，分析评价理论对语篇意识形态意义的揭示作用，并探讨对英语语篇教学的启示。分析结果表明：评价理论为大学英语语篇教学提供了新视角，用评价理论来指导大学英语语篇教学是行之有效的。     

英语语篇教学与实践效果分析

语篇中的情景图式直接影响着阅读的效果和理解的深度,并制约着学生的语言运用能力。语篇策略以获取最大限度有利于语篇接受者的语篇组织形式为目的,作出选择的主位或主题一致性语篇建构的策略。因此,在实践中围绕语篇的图示结构分析教学模式,重新建构语篇的言语和意义,进而提出相应的情景模式就显得至关重要。     

语篇与语篇类型

英语精读课文承载大量的知识,在日常英语教学中,词汇和语法不应是教学的重点,而应该是语篇。了解语篇和语篇类型,学生才能从课文中学到更多,真正掌握英语语言的本质。本文旨在讨论英语语篇的定义和语篇类型的划分,从而使英语学习者更好地掌握篇章语言学的相关基础知识,理解所学的语篇。     

电子商务环境下农村地区饲料直播营销探讨

互联网技术的快速发展及交通物流运输效率的提升为电子商务发展提供了重要的基础和平台。电子商务为产品销售提供了全新的模式，有效节约了营销成本，提升了产品销量。在电子商务环境下衍生出了多种多样的营销渠道，其中电子商务与短视频直播的创新结合创造出电子商务直播这一新兴营销模式。目前，直播营销已成为广受消费者欢迎的营销形式，也是企业营销的重点领域之一。饲料行业开始尝试使用直播营销开展饲料产品的销售和推广，并取得一定的成果。但不少饲料生产企业和采购企业所在地是农村，相比于城镇地区，农村地区在互联网和交通物流基础设施建设上存在明显不足，制约直播营销的发展。因此，本文基于电子商务环境下直播营销的发展趋势和特点，进一步分析农村地区饲料直播营销的发展现状和困境，并提出有效的改进建议和措施，为农村地区饲料电商商务直播营销提供参考。 [关键词]电子商务|农村地区|饲料|直播营销     

抗菌肽Tachyplesin Ⅰ的分子设计、结构与活性分析

本研究旨在抗菌肽Tachyplesin Ⅰ(TP Ⅰ)的结构活性基础上，重新设计一种全新的抗菌肽TP Ⅰ-Y4。保持母肽链长与电荷数不变，将序列中形成TP Ⅰ两个二硫键的4个半胱氨酸用酪氨酸进行替换后得到TP Ⅰ-Y4。经生物信息学软件分析，与TP Ⅰ相比，TP Ⅰ-Y4的热稳定性更好，亲水性更强，同时具有与母肽相似的结构与抗菌活性。化学合成后经圆二色谱检测发现，TP Ⅰ-Y4在水相及在模拟细胞膜疏水环境的50%三氟乙醇中都表现出β-折叠结构，疏水环境中TP Ⅰ-Y4的β-折叠含量高于水相，也高于不同环境中的TP Ⅰ。抑菌试验表明，TP Ⅰ-Y4对细菌和真菌都有较强抑菌活性，且对细菌的抑菌活性强于TP Ⅰ。TP Ⅰ-Y4对小鼠红细胞溶血性降低，并保留了很强的内毒素中和能力，浓度为40 μg·mL^-1时中和率可达50%以上。TP Ⅰ-Y4抗菌活性的提高以及溶血活性的降低，可能与β-折叠强形成者酪氨酸的替代有关，进而导致抗菌肽分子中β-折叠结构增强。     

茶多酚和L-茶氨酸对热应激下蛋用仔公鸡生长性能及抗氧化能力的影响

本试验采用单因子试验设计研究茶多酚与L-茶氨酸在热应激下对蛋用仔公鸡生长性能及抗氧化能力的影响。选用1日龄蛋用仔公鸡180只,随机分为6组,每组3个重复,每个重复10只鸡。试验1组为对照组,饲喂基础日粮;试验2~6组分别在基础日粮中添加400 mg/kg茶多酚、200 mg/kg L-茶氨酸、200 mg/kg茶多酚+200 mg/kg L-茶氨酸、400 mg/kg茶多酚+200 mg/kg L-茶氨酸、600 mg/kg茶多酚+200 mg/kg L-茶氨酸,试验期28 d。结果表明,茶多酚可有效降低热应激下蛋用仔公鸡的料重比（P<0.05）,L-茶氨酸单独添加或与茶多酚同时添加对生长性能影响均不显著（P>0.05）;茶多酚可显著降低各组织器官的丙二醛（MDA）含量 （P<0.05）,显著提高各组织器官的谷胱甘肽过氧化物酶（GSH-Px）与过氧化氢酶（CAT）活性（P<0.05）;L-茶氨酸能显著提高各组织器官的CAT活性（P<0.05）,不同程度降低各组织器官的MDA含量;茶多酚与L-茶氨酸同时添加时,抗氧化能力与茶多酚的添加量不呈正比;400 mg/kg茶多酚+200 mg/kg L-茶氨酸组肝脏样总超氧化物歧化酶（T-SOD）与GSH-Px活性均显著降低（P<0.05）,MDA含量显著提高（P<0.05）。在热应激条件下,200 mg/kg茶多酚+200 mg/kg L-茶氨酸同时添加时,抗氧化效果较理想。     

茶多酚和有效微生物对育成期水貂粪便污染物排放量的影响

为研究饲粮中添加茶多酚(TP)和有效微生物(EM)对育成期水貂粪便污染物排放量的影响,试验选取400只育成前期水貂共160笼,随机分成8组,每组20个重复。采用两因素试验设计,共8个处理组,基础饲粮中分别添加0 EM+0 TP、0 EM+0.05%TP、0 EM+0.1%TP、0 EM+0.2%TP、200 mg/kg EM+0 TP、200 mg/kg EM+0.05%TP、200 mg/kg EM+0.1%TP、200 mg/kg EM+0.2%TP。预试期1周,正试期8周(前4周为试验I期,后4周为试验Ⅱ期)。结果表明:饲粮添加TP不能减少水貂粪便NH3、H2S和CO2生成量;饲粮添加200 mg/kg EM对水貂粪便NH3(48 h)、H2S(72 h和96 h)生成量有显著影响(P0.05);饲粮添加0.1%及0.2%TP可显著降低试验Ⅱ期粪便中氨氮含量(P0.05),饲粮添加200 mg/kg EM可降低粪便中总氮(试验I期)、总磷(试验I和Ⅱ期)、氨氮和亚硝酸盐氮(试验Ⅱ期)含量(P0.05)。由此可见,饲粮添加EM可以减少水貂粪便恶臭气体生成以及粪便污染物的含量,建议水貂饲粮中添加200 mg/kg EM。     

Influence of prenatal testosterone treatment on foetal and prepubertal LHbeta-subunit mRNA and plasma LH concentrations in the female pig

The aim of this study was to investigate the potential role of foetal androgens in determining the sexual dimorphism in LH gene expression. Starting on day 30 p.c. pregnant sows were treated i.m. with testosterone propionate (TP) three times at 2-day intervals (TP30 treatment) or received additional TP treatment starting on day 40 p.c. (TP30/40). Sows were allowed to farrow and after frequent blood samples for LH determination were collected prepubertally (6 months) from the female offspring anterior pituitary LHbeta subunit mRNA levels were determined. In Experiment 2 pregnant sows were treated as TP30 before or received similar treatment starting on day 40 p.c. (TP40), but anterior pituitary LHbeta mRNA and plasma LH concentrations were determined at day 80 p.c. TP30 or TP30/40 treatment did not affect mean plasma LH concentrations nor LHbeta mRNA levels at 6 months of age but caused marked masculinization of external genitalia. At day 80 p.c. LHbeta mRNA and plasma LH levels were higher in female than in male foetuses. TP40 treatment suppressed LHbeta mRNA and plasma LH levels while TP30 treatment had no effect on LHbeta mRNA levels but caused masculinization of external genitalia in contrast to TP40. Our findings support the notion that the peak in plasma testosterone observed by others in the male pig foetus 5 weeks p.c. not only determines sexual differentiation of the LH surge mechanism but also LH gene expression in the foetus. The critical period for this process seems to succeed phenotypic differentiation (which appears to be largely completed before day 40 p.c.). The tonic mode of prepubertal LH gene expression and LH secretion in female pigs is not affected greatly by testosterone treatment at the stages of development that were investigated.     

模拟白洋淀芦苇湿地系统对鸭粪废水中磷的净化研究

通过原状芦苇土柱灌溉鸭粪废水的室内模拟试验,探讨了芦苇湿地系统对废水中总磷的净化规律,并估算了芦苇湿地系统的磷环境容量,结果表明,在低、中、高浓度的鸭粪废水处理下,芦苇生物量分别比对照增加36.1%,24.4%,24.3%。不同时期的芦苇湿地系统对鸭粪废水中总磷的去除效果均十分明显,去除率达到98%左右;水力停留时间达到3 d后,芦苇湿地系统对废水中总磷的净化过程趋于缓慢。不同时期的芦苇湿地系统对废水总磷的净化均遵从乘幂函数方程,当温度T=23℃时,芦苇湿地系统对废水中总磷的净化效果最佳,在高浓度处理条件下所需水力停留时间最短,参与净化苇地面积最小,方案最佳,以此为依据核算出芦苇湿地系统的磷环境容量约为171.71 t/a。     

Comparative feeding value of tapioca pellets for feedlot cattle.

A feedlot growth-performance trial and a metabolism trial were conducted to evaluate the comparative feeding value of tapioca pellets (TP). In the growth-performance trial treatments consisted of a steam-flaked corn (SFC)-based finishing diet in which a blend of 86% TP and 14% peanut meal replaced SFC at the rate of 0, 15, or 30% of diet DM. Daily weight gain (P less than .10) and DM intake (P less than .01) were greatest when 15% of the diet DM consisted of TP. Feed/gain increased linearly (P less than .01) with TP substitution into the diet. Treatment effects on carcass merit were small (P greater than .10), except that marbling score was greater with 15% TP than with either 0 or 30% TP. In the metabolism trial involving four Holstein steers, treatments consisted of an 88% concentrate diet containing 67% of either SFC or TP. Ruminal and total tract digestibility of starch was similar (P greater than .10) for SFC and TP, averaging 91 and 99%, respectively. Postruminal (P less than .05) and total tract (P less than .01) digestibility of N was lower for the TP than for the SFC diet. Total tract digestibility of N in TP was 3%. Little, if any, ADF in TP was fermented in the rumen. Total tract digestibility of ADF in TP was 16%. Total tract digestibility of DM (P less than .01) and OM (P less than .05) decreased 7 and 5%, respectively, with TP substitution for SFC. Virtually all the difference in OM digestibility could be attributed to differences in ADF excretion. The DE value of the diet decreased 11.5% (P less than .01) with the substitution of TP for SFC. It was concluded that TP can replace up to 30% of the DM in growing-finishing diets without adversely affecting ADG or DM intake of feedlot cattle. Tapioca pellets have approximately 86% the NE value of SFC.     

The influence of anticoagulants on the measurement of total protein concentration in equine peritoneal fluid

The aim of this study was to evaluate the influence of two commonly used anticoagulants (K3EDTA and lithium heparin) on refractometric and spectrophotometric measurement of total protein (TP) concentration in equine peritoneal fluid samples. The influence of a commercial solution of K3EDTA, a solution of K3EDTA in distilled water and lithium heparin on the refractometric and spectrophotometric (biuret) quantification of TP content in peritoneal fluid samples was assessed. Total protein concentration measured by refractometry was consistently overestimated in samples with commercial K3EDTA. The solution of K3EDTA in distilled water only caused TP overestimation at high K3EDTA concentrations (>5 micromol/ml). By contrast, lithium heparin did not influence the refractometric values of TP. Neither anticoagulant modified TP values when measured by the biuret method. In conclusion, the use of K3EDTA as anticoagulant may result in a significant overestimation of TP values of peritoneal fluid samples measured by refractometry.     

In vitro and in vivo comparison of applanation tonometry and rebound tonometry in dogs

Intraocular pressure (IOP) evaluated by applanation tonometry via TONO-PEN XL (TP), and rebound tonometry via TonoVet (TV) were compared in enucleated canine eyes with varied pressure of the anterior chamber (AC) and in clinical cases. TV measured IOP values were lower than IOP measurements of TP in the enucleated eyes with 5-10 mmHg of AC (P<0.0001), though there was no significant difference in IOP values obtained with TP and TV on the pressure ranges of 15-20 mmHg. However, TP detected IOP values were lower than IOP measurements of TV in the eyes with over 25 mmHg of AC (P<0.0001). The results of clinical cases were similar to the enucleated eye model. There was no significant difference in IOP values obtained from TP and TV in dogs with normotensive eyes. IOP measurements of TP were lower than those of TV in glaucomatous eyes (P<0.0001). TV was a reliable tonometer for measurement of IOP in hypertensive eyes, whereas it was less accurate than TP in hypotensive eyes. The characteristics of TP and TV should be considered in the evaluation of IOP in practice.     

封闭性和开放性沼泽湿地土壤全磷的季节变化特征

以吉林省通榆县付老文泡和二百方子湿地为对象,对比研究了封闭性和开放性湿地土壤全磷含量的季节变化特征及其与土壤理化性状的关系。结果表明:付老文泡湿地0～100cm深度的土壤全磷含量范围为48.77～377.19mg/kg,二百方子为45.65～574.17mg/kg,随季节变化呈现先减后增的变化趋势,即12月-次年5月土壤全磷含量较高,5-7月逐渐下降,在7和8月出现最低值,9和10月含量较低且变化不大,10-12月含量又逐渐回升。土壤全磷主要分布在0～40cm土层,深层含量较低且差异不大;2类湿地土壤全磷含量均未达到生态毒性效应水平。植物地上部分全磷量与土壤全磷之间存在显著的正相关关系,付老文泡湿地植被生长受氮磷协同限制,而二百方子湿地植被主要受氮含量限制。2类湿地土壤全磷与土壤全氮、有机质及粘粒显著正相关,与土壤C/N无显著相关关系;但pH值仅与二百方子湿地土壤全磷显著负相关,与付老文泡湿地土壤全磷无显著相关关系。