Comparative studies on the biochemical characteristics of natural actomyosin isolated from PSE and normal pork

Biochemical changes of natural actomyosin from fresh pale, soft, exudative (PSE) and normal pork were studied, and the effects of different storage temperatures and different incubation temperature and times on sample superprecipitation, total sulfhydryl (-SH) content, and ATP (adenosine triphosphate) sensitivity were investigated. The results demonstrated that ATPase activity and thermal stability of PSE actomyosin were lower than those of normal pork; and that PSE actomyosin had higher -SH content than that of normal pork at all incubation temperatures and times tested.     

论《论衡》的训诂特色

《论衡》训诂有着自己鲜明的特色，主要体现为：《论衡》正文训诂资料的训诂目的与随文作注式训诂不同；《论衡》正文训诂是为阐明作者的观点或批驳他人的观点服务的，词语训释系列集中体现了这一目的；《论衡》中的训诂不包括校勘文字、指明用字现象等内容，对俗语词及一般词语的解释所占比例最高，这不同于一般随文注释的训诂书；训诂方法以又训为主，很少用声训，不用形训，是由其训诂目的决定的；训诂术语数量多，一般名异实异，也存在名异实同的现象，训诂体式不拘一格，这是其训诂术语、训诂体式上的特点；《论衡》经行将意义相近、相关、相反、相对的词语对举，构成训释系列，体现了王充的系统观。     

重庆自然洞穴的特色与开发利用

自然洞穴是十分宝贵的地下空间资源,是地质遗迹中的重要组成部分,人类进化和发展,与其休戚相关。重庆洞穴资源丰富多彩、类型全、品位高、奇观多,利用历史悠久。特别是近年十余次中外联合科考探险,又发现了一批新的资源,积累了丰富的经验。但综合利用、科学开发和洞穴资源的保护尚待加强。     

A meta-analysis on the relationship between school characteristics and student outcomes in science and maths – evidence from large-scale studies

ABSTRACT

In the present meta-analysis, we examine how secondary school characteristics – such as schools’ academic press, school climate, material resources, personnel resources, classroom climate, instructional practices, out-of-school activities, and socioeconomic status (SES) composition – provide opportunities for students to engage in science and maths, and how these matter with regard to students’ cognitive and motivational-affective outcomes. The meta-analysis includes 71 (international) articles from large-scale studies with a total of 3,960,281 students, 260,390 schools, and 285 effect sizes that were transformed to correlation coefficients. Multilevel meta-analyses were performed. Results identified a number of school variables that can be regarded as relevant for making a difference in student outcomes and at the same time be influenced by education. These refer to school variables such schools’ academic press, classroom climate, instructional practices, and out-of-school activities. Moreover, SES composition was significantly related to student outcomes. Material and personnel resources as well as school climate yielded a close to zero effect. No differences were found between cognitive and motivational-affective outcome variables or between science and maths. The results point to the most promising school characteristics for promoting students’ outcomes and emphasise schools’ potential for students’ engagement in science and maths.     

论教育自信视角下中国特色师范教育体系的建构——基于120余年师范教育发展历程的反思

自信的缺失与自我关照的不足是我国师范教育发展中的痼疾,也是阻碍中国特色师范教育体系建设的重要因素。建设中国特色师范教育体系必须基于对"中国特色"的科学理解、对师范教育和基础教育互动逻辑的系统把握、对师范教育发展历史及现实的深入分析、对师范教育发展国内外态势的全面了解,全面贯彻教育自信的要求,凸显对自我的关照,从发展心理、理论体系和实践范式等多个方面系统推进。     

Purification and studies on characteristics of cholinesterases from Daphnia magna

Due to their significant value in both economy and ecology, Daphnia had long been employed to investigate in vivo response of cholinesterase (ChE) in anticholinesterase exposures, whereas the type constitution and property of the enzyme remained unclear. A type of ChE was purified from Daphnia magna using a three-step procedure, i.e., Triton X-100 extraction, ammonium sulfate precipitation, and diethylaminoethyl (DEAE)-Sepharose?-Fast-Flow chromatography. According to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), molecular mass of the purified ChE was estimated to be 84 kDa. Based on substrate studies, the purified enzyme preferred butyrylthiocholine iodide (BTCh) [with maximum velocity (V _max)/Michaelis constant (K _m)=8.428 L/(min·mg protein)] to acetylthiocholine iodide (ATCh) [with V _max/K _m=5.346 L/(min·mg protein)] as its substrate. Activity of the purified enzyme was suppressed by high concentrations of either ATCh or BTCh. Inhibitor studies showed that the purified enzyme was more sensitive towards inhibition by tetraisopropylpyrophosphoramide (iso-OMPA) than by 1,5-bis(4-allyldimethylammoniumphenyl) pentan-3-one dibromide (BW284C51). Result of the study suggested that the purified ChE was more like a type of pseudocholinesterase, and it also suggested that Daphnia magna contained multiple types of ChE in their bodies.     

流化床中PVC粉末干燥特性研究

为了获得流态化干燥状态下的粉体干燥曲线,设计了一种小型流化床干燥装置用于粉体材料的干燥特性测定.应用该装置,实验研究了悬浮法PVC粉体的干燥特性.测定的PVC粉体在该流化床中流化参数为操作气速介于0.41～0.55 m/s之间,即流化数ua/umf为1.24～1.67.实验测定了PVC粉体干燥动力学曲线,回归得到描述PVC干燥特性曲线的解析函数为f=-0.622 6 1.254 6exp(2.561 5Φ-0.707 2)/1 exp(2.561 5Φ-0.707 2).确定了实验条件下PVC干燥的临界湿含量xc及传质系数K分别为0.02 kg/kg和6.0×10-4kg/(m2·s).由于实验方法比较接近工业流态化干燥过程,获得的结果对于工程应用较为可靠,该方法可用于如PVC一样的粉体材料的干燥特性测定.     

由植物油提取的合成润滑剂的流变特性和摩擦特性

The double bonds in the vegetable oils can be conjungated and Diels-Alder react when they are heated in the existence of the catalyst. The percent of the double bond will decrease and the oxidative stability of the vegetable oils can be ameliorated. Dimmer acid can react with different carbon chain length of alcohols to form dimmer acid esters. A series of dimmer acid esters were synthesized and their rheological characteristics （viscosity, viscosity index, pour point） and tribological characteristics （the coefficient of friction at different load, the characteristic of extreine pressure （ PB ）, the wear scare diameter （ D30min^196N ） were evaluated and analyzed. The results showed that the characteristics of Di-iso-octanol dimmer acid ester were the best among the synthesized dimmer esters. It＇ s a lubricant with good properties（the viscosity is 94.5 mm^2/s, the viscosity index is high up to 141 and the pour point is - 49℃ ）. It is a kind of newly interesthing ester type lubricant. Its rheological and tribological characteristics are even better than those of the slap-up synthesized lubricant--pentaerythritol esters （C7-9 acidate）. The FT-IR spectrophotometer was used to analyze the structure of the synthetic esters. Their IR spectra are the same as the typical IR spectrum of ester. The test indicated that Di-iso-octanol dimmer acid ester could be used as a kind of base lubricant with excellent quantity.     

论当代中国政党制度的特色与功能

共产党领导的多党合作制度是具有中国特色的社会主义政党制度。其特色在于 ,一党领导、多党合作 ;一党执政、多党参政。这一政党制度充分适应我国经济基础 ,促进生产力发展 ,能够有效拓展社会参与渠道 ,最大限度地整合政治资源 ,实现和维护广大人民群众的利益。     

论比较教育思想的演进及特征

对比较教育思想进行研究是一个十分迫切而重要的课题。比较教育思想的演进大致经历了史前溯源、初步产生、体系形成、多元发展和理性建构五个阶段。在演进过程中呈现出了社会性、独特性、本质性、实践性、指导性、多元性、局限性的总体特征;比较教育思想的内容体系也表现出学科理论的体系性、方法论的核心性、目的论的统一性、研究单位的拓展性和研究内容的丰富性特征。     

菊芋秆两相发酵产气特性研究

采用两相技术和排水集气法,研究了菊芋秆的产气特性.结果显示,菊芋是潜在的能源植物,厌氧发酵48 d,菊芋产气量为40518 mL,利用率为60.5%,具有潜在的利用价值.     

师范院校的特色发展战略与改革趋向研究

“十五”期间,我国教师教育改革取得显著成绩,尤其是以北京师范大学为代表的一些学科综合、实力雄厚的师范院校,通过调整和战略转型,成为以教师教育为主要特色的综合性大学。目前,许多师范院校都认同了战略转型的理念,将自己的学校明确地定位为综合性、研究型,或科研与教学并重的大学。实践证明,这些师范院校通过战略转型,不仅学科实力和综合办学实力明显提升,为社会主义现代化建设提供了多样化、高素质人才支持和智力支持,而且进行了我国学士后教师教育的探索,为建立一流的教师教育和教育科研基地奠定了坚实基础。但是,由于国家没有把师范…     

普通高校足球训练特征的研究

足球运动是一项有益身心的健康运动,在各大高校都设有足球专业,有专门的足球高水平运动员。我国普通高校在开展足球训练的过程中,有一些较为明显的特征,训练状态并不尽如人意。本文将对普通高校的足球训练特征进行分析,并为如何改进训练中存在的问题提供建议。     

云南木蠹象生物学特性观察与防治研究

2002—2007年,在贵州威宁县海拉、岔河、观风海、秀水等乡镇,实地调查云南木蠹象生活史及危害情况,并在秀水乡新民村15年生云南松飞播林内,观察成虫野外羽化、取食、飞翔、交尾、产卵等习性,基本掌握了云南木蠹象的危害情况、生活史及其生物学特性。通过野外放飞试验和林间观测,发现成虫可以飞行,最远飞行距离为97.4m,飞行高度6.0m,成虫在林内活动范围较大。对云南木蠹象的飞翔能力(高度和距离)、性成熟时间、寻偶交尾方式和过程的观察结果,为探索利用云南木蠹象性信息素提供了依据。同时,采用化学防治和人工清理虫源木对虫害进行防治。     

“韩欧”文价值认识比较论

唐代韩愈、宋代欧阳修是中国古代散文代表唐宋八大家中的领袖人物,“韩欧”是唐宋散文、正统散文、文以明道、古代成熟散文的标志。历史上对“韩欧”文价值的比较认识存在差异,有韩高欧低、欧高韩低、“韩欧”各具特色、“韩欧”否定论等各类看法,本文就此进行归纳探讨。     

足球战术教学的特点研究

现代社会,足球不但被作为一种体育竞技项目,同时也是一种有效的健身项目。随着人们对足球喜爱程度的增加,足球战术教学被人们所广泛关注。在足球教学中,教师积极研究各种战术,以期可以通过提高足球队员之间的团结协作能力,来取得足球比赛的胜利。可见,在足球比赛中,足球战术占有重要的作用。本文主要针对足球战术教学的特点进行探讨。     

儒家人文精神探源及其特性

儒家的人文精神肇端于孔子诞生前的唐尧、虞舜、夏禹时形成的丰厚的人文传统,其特性是以道统治世、内圣外王并行不悖,科技、人文与宗教三领域心物平行,历史悠久、文化绵长,是一种实践理性,渗透在世代中国人的不断延续中,具有内在与超越、自然与人文、道德与宗教结合以及"我不入地狱谁入地狱"的极世献身的热忱。     

浅谈网络交际的基本特征及其规制

网络交际是现实人际关系在网络中的延伸，其基本特征为主体参与匿名化，关系建立简易化，交往手段数字化，发展方向“熟人”化。实现对网络交际的有效规制，应主要运用舆论、道德和技术三种手段。     

浅析广告英语的词汇特征

广告语言受文学、美学、心理学、市场营销学和消费行为学等多学科的影响,具有其独特的语言特征。本文从词汇层面,分析广告英语的选词、用词、构词特征,并对广告文本进行分析。     

Perpetrator status and the personality characteristics of molested children

The personality and intellectual characteristics of three groups of children, one molested by a teacher (n = 16), a second group (n = 16) where the offender was a member of the child's family, and a non-molested control group (n = 16) were contrasted. The children were evaluated using the Personality Inventory for Children (PIC), the Children's Personality Questionnaire (CPQ), and the Wechsler Intelligence Scale for Children (WISC-R). There were few differences between the two molested groups or between boys and girls. However, comparisons of molested and non-molested children showed significant differences on 23 of 34 scales on the PIC and CPQ combined. WISC-R verbal IQs were also lower for the molested groups. While the lack of differences between the two molested groups may have been due to the parent-like relationship between the teacher and the children he molested, the results suggest that a relatively noncoercive style of abuse can still produce significant psychological impairment.