教学产品是怎样形成的

1在木桶里寻求答案当然．对教师来说．“产品”一词还不能象“教学结果”概念那样被普通使用。在使用这个词的时候．往往是每次不得不作准确说明．即在每一具体场合，所指的是怎样一种结果。不知是指可以用肉眼看得到的知识、技能、能力．还是指深刻的潜在的新生物——个人的思维水平和类型．世界观和视野、兴趣和认识的需要、工作厅式、积极性．热爱劳动及为教学所形成的其它各种品质。要想对不确定的结果作系统分析是件困难的事·然而对4一切创造过程来说“产品”和“产品率”的一般概念可以使思想、体系和结构更加清晰。它们开辟了由教学…     

Theoretical design for a class of chaotic stream cipher based on nonlinear coupled feedback

1.INTRODUCTION Inordertoimprovethesecurityofchaosencryption system,wecaniteratethechaossystem.Themore chaossystemiterates,themorecomplexitbecomes, andthemoresecurethecorrespondingchaosencryp tionsystembecomes.Zhouetal[1]proposedaclassof chaoticsequencegeneratorinwhichthelinearseg mentnumberincreasedwiththeiterationnumberex ponentially.Withtheincreaseoftheiterationnum ber,thesecurityofthesystemincreaseswhilethe rateofencoding/decodingdecreases.Inaddition,the phase spacegraphhassomedefe…     

Canada baboon cruelty trial

A physiologist and the chief veterinarian at the University of Western Ontario are facing possible prosecution for cruelty to animals because of an experiment in which a baboon was kept for several months in a restraining chair. The case is believed to be the first in Canada brought against researchers following complaints by an animal welfare group. The experiment was supported by the Canadian Medical Research Council and the Ontario Heart and Stroke Fund, and the protocol and laboratory were approved by the Canadian Council on Animal Care.     

Biotechnology regulation: White House holds the ring

The dispute among federal agencies over regulation of commercial biotechnology has been addressed in the Federal Register by the Office of Science and Technology Policy (OSTP), which says the Recombinant DNA Advisory Committee of the National Institutes of Health should continue to oversee biomedical research in this area, while the Environmental Protection Agency should formulate regulatory policies for industry and resolve such issues as when a microorganism constitutes a new chemical substance. OSTP also proposes four new independent expert committees to advise the EPA, the Food and Drug Administration, the Department of Agriculture, and the National Science Foundation, and a Biotechnology Science Board to coordinate the work of the committees.     

用爆炸波起爆癸烷云雾的两种模式

用垂直激波管研究了400μm癸烷液滴与空气混合物的爆炸波起爆。每种混合物有两个极限起爆能值,即高值Ecu,和低值Ecl。当起爆能的值高于Ecu时,观察到100%发生爆轰;而当其低于Ecl时,就不会发生爆轰。有趣的是,当起爆能水平在Ecu和Ecl之间时观察到对应于不同的起爆能水平有不同的起爆行为。如实验结果所表明的,爆轰的激发不仅是由于直接起爆,而且也由于“爆燃”到爆轰的转变。     

适用的哲学与认识的工具

一、适用的哲学最近几十年来,科学信息空前爆炸,以致就具体而积极地研究认识方法来说,"自然哲学"变得太广泛了.对此,物理学家、生物学家、心理学家以及其他在本学科领域进行创造性工作的专家,都应该加以研究;或者自己研究,或者和相应的科学史专家合作研究.严肃的科学著作不能没有哲学,但哲学应该是"具     

美东地区罗德河流域地下水中铝形态分布的化学平衡模式计算

美东地区的罗德河流域遭受着严重的酸沉降侵蚀．在酸性条件下,铝从土壤中大量溶解并迁移到水环境中．地表水中升高的铝浓度对鱼类产生毒害,监测地表水和土壤水中的铝形态及浓度变化已成为问题的关键．本文报导了用化学平衡模式计算法分析美东地区罗德河流域地下水中的铝形态分布,获得了有价值的结论