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1.
归纳给出了普通物理教学中模型等效代替、过程等效代替、作用等效代替、本质等效代替等4种常用的等效代替方法  相似文献   

2.
怎样在小学数学课堂教学中明确学生的主体地位,优化学习过程,促进学生自主学习,是值得不断探索和完善的议题.该文提出,数学课堂教学要坚持做到四个“不代替”:不代替教材去重述学生自己能学会的内容,不代替学生去说出他们自己经过努力能总结出的结论,不代替学生去思考,教学中不代替学生去动手操作.  相似文献   

3.
简论普通物理教学中的等效代替   总被引:1,自引:0,他引:1  
归纳给出了普通物理教学中模型等效代替,过程等效代替,作用等效代替,本质等效代替等4种常用的等效代替方法。  相似文献   

4.
对所拥有的资源进行有效的计划、组织、领导和控制,以便达到即定目标。管理意味着用智慧代替鲁莽,用知识代替习惯与传统,用合同代替强制。  相似文献   

5.
彭金芬 《科技信息》2008,(21):119-119
对所拥有的资源进行有效的计划、组织、领导和控制,以便达到即定目标。管理意味着用智慧代替鲁莽,用知识代替习惯与传统,用合同代替强制。  相似文献   

6.
教师设计"课堂教材"代替"预编教材"在国际外语教学界已经盛行。由于教学观念偏差,考核制度落后,师资力量薄弱等因素,我国大学外语教学仍然以统一使用"预编教材"为主,造成以教科书代替教学目标和教学内容,以教学参考书代替教案的局面,严重影响综合运用语言能力的培养。教师设计"课堂教材"时应以语义为纲代替语言形式为纲,以环式安排代替线性安排,以教学资源库代替教科书。  相似文献   

7.
包含代替置换网络的分组密码是一种广泛使用的分组密码系统。论文介绍了一种基于全非奇异矩阵的代替置换网络 ,它可有效的提高分组密码抗线性密码分析的能力。论文给出了基于全非奇异矩阵的代替置换网络的线性壳概率上界。证明了当使用大规模的基于全奇异矩阵的代替置换网络时 ,i圈基于全奇异矩阵的代替置换网络的线性壳概率上界迅速减小。指出了使用大规模的基于全奇异矩阵的代替置换网络可有效地提高分组密码抗线性密码分析的安全性  相似文献   

8.
在分组密码的设计中 ,提高分组密码的抗差分攻击性能是一个重要的课题。论文提出了一种基于矩阵的代替置换网络模型。基于这一模型 ,设计了一个称为基于全非奇异矩阵的代替置换网络的密码结构。给出了基于全非奇异矩阵的代替置换网络的差分概率上界。证明了当使用大规模的基于全奇异矩阵的代替置换网络时 ,i圈基于全奇异矩阵的代替置换网络的差分概率上界迅速减小。指出了使用大规模的基于全奇异矩阵的代替置换网络可有效地提高分组密码抗差分密码分析的安全性。  相似文献   

9.
考察在基础培养基和补糖中用液化液代替液化糖对 Streptomyces lincolnensis 13生长及林可霉素发酵效价的影响.结果表明:在基础培养基中用液化液代替液化糖,发酵效价提高了8.6;,而在基础培养基和补糖中都用液化液代替液化糖,发酵效价提高了12.4;.液化液在基础培养基和补糖中代替液化糖生产林可霉素是可行的.  相似文献   

10.
通过对枸杞组织培养的培养基部分成分的改换,发现用普通白砂糖代替蔗糖、自来水代替重蒸水、回收琼脂代替实验用试剂级琼脂,并去掉肌醇,对枸杞分化苗的增殖、生根无明显影响,可大幅度降低枸杞组培苗的成本.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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