共查询到20条相似文献，搜索用时 125 毫秒
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从快速生长、性别分化、提高产卵率、提高孵化率、病害防治五个方面介绍中华鳖养殖技术研究的进展,着重介绍弱光对稚鳖摄食和生长的影响、对雌鳖产卵的促进. 相似文献
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郑紫微 《少年作文辅导(中学版)》2005,(10)
看了题目,你可千万别以为“鳖王”是鳖中之王。我这“鳖王”指的是养鳖大王——我叔叔。记得那年冬天,我到叔叔的家里去拜年。第一眼就看到两个显眼的水池,走近一看,啊!这么多鳖,我真想数一数有多少只。叔叔好像看穿了我的心思,对我说:“这里一共有600多只鳖。”我惊讶得差点跳 相似文献
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近年 ,我地有些养殖户用笼格式方法养鳖获得成功。用这种方法饲养幼鳖、成鳖均可 ,密度大、产量高 ,每平方米可养１０ -２０只 ,而且饲喂方便。起捕容易 ,鳖不易受到敌害生物侵扰 ,发病率较低。既可在庭院中用自来水小规模养殖 ,也可以在大中河流湖泊中置笼养殖。一、笼格的制作安置。材料选用木板或塑料板 ,也可用水泥预制成型 ,板厚０．５ -１厘米 ,长１．５ -２米。根据所饲养鳖的大小设计出笼格的大小。一般来说 ,２５０克以上的成鳖所用笼格大于３０×２０平方厘米 ,２５０克以下的幼鳖所用笼格大于２５×１５平方厘米 ,１平方米应有１… 相似文献
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史京景 《新语文学习(小学作文)》2002,(18)
鳖虽然小，却很灵活，我把它四脚朝天放在地上，它伸长脖子，把头往地上一顶，就翻了过来。它很喜欢游泳，将它放入水中，便会高兴地游来游去。四只小爪子就像两对小桨，不停地划动着。还不时地把头露出水面，微微张开月牙形的嘴，换换气。小鳖爱吃猪肉和虾米，它吃食时有时细嚼慢咽，有时狼吞虎咽。先用鼻子碰碰，再用前爪按住食物，用嘴使劲地撕扯，吞进肚里。看着它这副馋相，我开心极了。养鳖小记@史京景$江苏省六合县雄州镇紫霞街中心小学五(1)班 相似文献
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鳖致病性细菌与病毒的研究 总被引：2，自引：0，他引：2
对鳖致病性细菌与病毒的研究进行评述：包括病原及其所诱发的疾病；当前颇具争议的焦点问题──细菌与病毒哪个是病鳖中主要的致病病原．并在建立致病性细菌与病毒的早期快速诊断方法方面提出一些浅见． 相似文献
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Lei SJ 《Journal of Zhejiang University. Science. B》2006,7(7):580-585
The effects of ration level and feeding frequency on digestibility in juvenile soft-shelled turtle, Pelodiscus sinensis, were investigated. Four ration levels 1.5%, 2.5%, 4.0% and satiation （6.0% BW/d） were used. Apparent digestibility （AD） of dry matter （DMAD）, protein （PAD） and protein real digestibility （PRD） were significantly affected by ration level, but not by feeding frequency when the ration level was similar. However, the feeding frequency affected the AD, DMAD, PAD and PRD significantly when the turtles were fed to satiation. The relationship between fecal protein content （Y） and protein intake （At） can be expressed as a quadric equation： Y=-0.1742＋0.1476X-0.0003X^2 （r^2=0.876, n=27, F=93.92, P〈0.01）. 相似文献
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J. Rachel Smith Blair Witherington Joe E. Heimlich Rebekah J. Lindborg Emily Neidhardt Anne Savage 《Environmental Education Research》2019,25(2):292-308
To understand both immediate and longer-term effects of a short duration, interpretive wildlife tourism program, we studied responses from participants in a sea turtle watch program. This program comprised an interpretive presentation followed by an opportunity to view a nesting loggerhead sea turtle (Caretta caretta). We conducted 37 programs in 2013 and 2014, for 843 participants, of whom 70.5% were able to see a nesting turtle. We measured participant attitudes, knowledge, intention to act, and long-term behavior change. Initial participant responses indicated prior interest in nature and environmental topics, and a knowledge base focused on biological sea turtle information. After the interpretive presentation, participants chose to provide conservation-related information as opposed to natural history-related information. Intention to engage in conservation behaviors was high following the turtle watch experience, regardless of whether a turtle was seen. The conservation value of our turtle watch program is expressed through conservation-focused knowledge acquisition by participants and their high post-program intention to engage in behaviors benefiting sea turtles, both of which precede long-term behavior change in an interdisciplinary model of behavior change. 相似文献
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汪宇 《重庆职业技术学院学报》2006,15(6):127-129
《熵》是美国后现代主义代表作家托马斯.品钦最成熟的一部短篇小说。在这部小说中,品钦首次运用热力学第二定律即熵定律来隐喻日益混乱的后现代社会。本文着眼于作品和《圣经》典故的相似点,将小说主人公之一卡里斯托修建的温室视为“伊甸园,”通过分析这个貌似和谐完美的乐园的毁灭,揭示出交流和沟通是抵御熵化的唯一办法,人们惟有增进相互间的交流和理解,才能抵御日益恶化的混乱状态,建立真正美好和谐的“伊甸园”。 相似文献
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何谓大学？有容乃“大”,大学为“学”。蔡元培执长北大后,围绕着“容”和“学”对北京大学进行改革,为之注入了现代大学的灵魂,使之由一个封建官僚的养成所变成名副其实的高等学府。蔡元培不仅是北京大学的缔造者,也是中国现代大学的开创者。 相似文献
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张掖地区华北落叶松苗期生长规律的研究 总被引：1，自引：0，他引：1
在物候观测、播种育苗及样地观测的基础上，研究了华北黎叶松苗木生长规律以及不同环境因子下幼苗的生长馈况，结果表明，塑料大物、塑料薄膜、土温室育苗都是行之有效的科技措施，华北露叶松属阳性材种，除当年播种苗需遮荫外，以后各个生育期需要在全日照条件下生长发育。此研究为加速苗木培育提供了理论依据和可行措施。 相似文献
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Lawrence B. Flick 《科学教学研究杂志》1990,27(3):219-231
How do children solve force and motion problems in computer simulations without explicit knowledge of the underlying physics? This question was addressed by saving the keystroke input of 19 sixth-grade children in computer memory as each interacted with a simulated, frictionless object using Logo turtle-graphics. The keystroke sequences were first used to determine subject performance on the gamelike features of the simulation. A second analysis used the Newtonian structure of the program to investigate alternative methods for controlling turtle velocity. Five boys and five girls were interviewed during the simulation concerning the perceived relationship between keyboard input and turtle behavior. Subjects who could clearly state some keyboard effects did not score high on either computer analysis, yet achieved the most general solutions of the computer problem. They did so by exploring turtle behavior under a greater variety of conditions than the subjects who achieved partial solutions. For the successful subjects, the turtle was related by analogy to useful information from existing conceptions of motion. 相似文献
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This note compares turtle geometry and Euclidean geometry with respect to their treatment of similarity and difference of plane figures. It is observed that while the Euclidean notion of congruence faithfully captures a common perception of sameness, the turtle expression of this idea is too weak. To deal with this insufficiency we add a new turtle operation, FLIP, which turns the turtle upside down. This brings the turtle's power to express invariance of shape up to Euclid's.The problem and its solution are viewed briefly from the perspectives of mathematics, computer science and education. The mathematical discussion compares the turtle group and the Euclidean group. The computational discussion focuses on the issue of expressive power of a language and how it may be enhanced. The educational discussion suggests a classroom implementation of the above ideas. 相似文献