从IBDP试卷看国际课程如何测评学生的物理语言表达能力

高中生物理语言表达能力的测评一直是我国物理教育中的弱项.以2019年至2021年的IBDP物理试卷为研究对象,从试题类型、设问方式及评价标准三方面对其进行统计分析和研究发现,试卷中语言的表达试题类型包括文字表达试题、符号表达试题和图表表达试题,设问方式多样,以解释说明类和定量评判类等深层分析为主,在评价过程中给予了学生更为广阔的思维和表达空间,对我国高中物理考试改革具有借鉴意义.

程序:物理对象上的操作表达式(英文)

把赋值语句看作物理对象上的操作时,程序就呈现为物理对象上的操作构成的表达式(简称O表达式)。给出了定义O表达式语法的BNF公式,并用公理规定O表达式的语义。主动式的O表达式以计算最终结果为目的,因而相关公理给出的是施行表达式中操作以后的变量与施行之前变量之间的准确依赖关系。反应式O表达式要对外来需求作反应。描述反应的公理规定如何反应。有关通讯的公理要求正确的信息被正确的接受者收到。共享变量公理则给出有关共享变量的性质判断。例子用于说明异步顺序O表达式的性质是如何分析的。

在物理教学中如何提高学生语言表达能力

要使学生物理语言表达更科学，准确，那就需要物理教师要重视物理语言表达的专业化，为学生做模范作用；在对学生垡行语专表达训练中，教师要努力地营造和谐的课堂，让学生善于表达。

如何培养学生的物理语言表达能力

分析了培养学生物理语言表达能力的方法及解题规范性的具体方法.

巧用“互联网+教育”培养八年级学生物理语言表达能力

巧用“互联网+教育”培养八年级学生物理语言表达能力,是当下核心素养的新局势,也适应了初中物理新课程标准的教学要求。 物理语言表达能力就是:能用简明准确的物理语言来表达有关物理概念、物理规律、物理现象、物理过程等一系列物理问题的能力。[1]初 中物理语言是培养学生学会科学用语,用科学语言来解释身边的物理现象,这就要求语言要准确精炼。教师巧用“互联网+教育”教学, 可以有效培养学生的物理语言表达能力。

培养初中学生物理语言能力的教学策略

语言是科学思维的重要表现形式。物理语言具有抽象性、严谨性和逻辑性,是初中生必备的基础能力之一。良好的物理语言能力有助于帮助学生建立完整的物理逻辑概念,理清基本的物理解题思路,使物理学习变得更加简单。本文结合相关文献和优秀课堂案例,归纳了培养初中学生物理语言表达能力、书写能力和图像能力的教学策略,并通过实践教学进行完善,力争为一线教师实现高效教学提供借鉴和参考。

提高学生运用常微分方程解决物理问题能力的教学实践

本文介绍在物理教学中引导学生更好地运用常微分方程解决物理问题的教学实践

对利用两个线圈产生圆形旋转磁场的探究

物理课是中学阶段非常有趣的一门课程,其中讲述的很多现象都与我们的现实生活联系紧密,很多现象不仅可以通过实验展示,而且还能通过数学公式的推导揭示其奥秘。物理中关于"磁场"的讲述,引起了笔者很多的联想,并由此产生了很多的疑问,通过利用磁场的物理表达和数学中的向量合成等知识,对空间两个相同线圈产生"圆形旋转磁场"的条件进行了探究,得出了相应的结论,并利用磁场的模拟演示和电磁场仿真软件的计算对圆形旋转磁场的产生进行了验证。

Analysis of radial basis function interpolation approach

The radial basis function （RBF） interpolation approach proposed by Freedman is used to solve inverse problems encountered in well-logging and other petrophysical issues. The approach is to predict petrophysical properties in the laboratory on the basis of physical rock datasets, which include the formation factor, viscosity, permeability, and molecular composition. However, this approach does not consider the effect of spatial distribution of the calibration data on the interpolation result. This study proposes a new RBF interpolation approach based on the Freedman＇s RBF interpolation approach, by which the unit basis functions are uniformly populated in the space domain. The inverse results of the two approaches are comparatively analyzed by using our datasets. We determine that although the interpolation effects of the two approaches are equivalent, the new approach is more flexible and beneficial for reducing the number of basis functions when the database is large, resulting in simplification of the interpolation function expression. However, the predicted results of the central data are not sufficiently satisfied when the data clusters are far apart.

Cancer stem cell markers CD133 and CD24 correlate with invasiveness and differentiation in colorectal adenocarcinoma

AIM:To verify that CD markers are available for detecting cancer stem cell populations and to evaluate their clinical significance in colon cancer.METHODS:Immunohistochemistry for CD133,CD24 and CD44 was performed on the tissue microarray of 523 colorectal adenocarcinomas.Medical records were reviewed and clinicopathological analysis was performed.RESULTS:In colorectal adenocarcinoma,128 of 523 cases(24.5%) were positive and 395 cases(75.5%) were negative for CD133 expression.Two hundred and sixty-four of 523 cases(50.5%) were positive and 259 cases(49.5%) were negative for CD24 expression.Five hundred and two of 523 cases(96%) were negative and 21 cases(4%) were positive for CD44 expression.Upon clinicopathological analysis,CD133 expression was present more in male patients(P = 0.002) and in advanced T stage cancer(P = 0.024).Correlation between CD24 expression and clinicopathological factors was seen in the degree of differentiation(P = 0.006).Correlation between CD44 expression and clinicopathological factors was seen in the tumor size(P = 0.001).Survival was not significantly related to CD133,CD24 and CD44 expression.CONCLUSION:CD markers were related to invasiveness and differentiation of colorectal adenocarcinoma.However,CD expression was not closely related to survival.

Adapting Property Path for Polynomial-Time Evaluation and Reasoning on Semantic Web

Property path is the latest navigational extension of the standard query language SPARQL 1.1 for the Semantic Web.However,in the existing SPARQL query systems which support property path,the query efficiency is very low and does not support reasoning.This paper proposes a new existential semantics which has polynomial-time evaluation complexity and an equivalent relationship with the current semantics,and transforms the property path expressions to the extended nested regular expressions based on the existential semantics and proves the semantic equivalence after the transformation considering the RDFS semantics.The property path query engine is achieved by implementing the nested regular expressions algorithm and the transformation rules from the property path expressions to the nested regular expressions,which maintains the syntax simplicity of property path and the goal-oriented polynomial-time reasoning to avoid computing the RDF graph closure.The experiment results not only show the characteristics of query engine based on the existential semantics in efficiency and reasoning,but also further validate the equivalence between the results based on current semantics and those based on the existential semantics for property path after the removal of duplicate values.

Performance Analysis of Physical Layer Security over α-η-κ-μ Fading Channels

In this paper, we consider the secure data transmission over α-η-κ-μ fading channels, which are recently proposed to encompass nearly all the well-known statistical models adopted in the literature. In particular, we address the secrecy performance in terms of the average secrecy capacity(ASC) and the secrecy outage probability(SOP), for which novel analytical expressions are derived. Simulation results verify the analysis and demonstrate the impact of the physical parameters on the secrecy performance of this new channel fading model.

Influence of expressed TRAIL on biophysical properties of the human leukemic cell line Jurkat

The cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) was cloned into RevTet-On, a Tetregulated and high-level gene expression system. The gene expression system was constructed in a human leukemic cell line: Jurkat. By using RevTet-On TRAIL gene expression system in Jurkat as a cell model, we studied the influence of TRAIL gene on the changes of cellular apoptosis before and after the TRAIL gene expression, which was induced by adding tetracycline derivative doxycycline (Dox). The results indicated that the cellular apoptosis ratio was largely dependent on the TRAIL gene expression level. Moreover, it was found that the apoptosis-inducing TRAIL could cause significant changes in the biophysical properties of Jurkat cells. The cell surface charge density decreased, the membrane fluidity declined, the elastic coefficients K_I increased, and the proportion of α-helix in membrane protein secondary structure decreased. Thus, the apoptosis-inducing TRAIL gene caused significant changes on the biomechanic properties of Jurkat cells.

Research on Partial Coefficients for Design of Quarter-circular Caisson Breakwater

The quarter-circular caisson breakwater （QCB） is a new type of breakwater, and it can be applied in deepwater. The stability of QCB under wave force action can be enhanced, and the rubble mound engineering can be less than that of semi-circular breakwaters in deepwater. In order to study the wave force distribution acting on the QCB, to find wave force formula for this type of breakwater, firstly in this paper, the distribution characteristics of the horizontal force, the downward vertical force and the uplift force on the breakwater were gotten based on physical model wave flume experiments and on the analysis of the wave pressure experimental data. Based on a series of physical model tests acted by irregular waves, a kind of calculation method, which was modified by Goda formula, was proposed to carry out the wave force on the QCB. Secondly, the reliability method with correlated variables was adopted to analyze the QCB, considering the high correlation between wave forces or moments. Utilizing the observed wave data in engineering field, the reliability index and failure probability of QCB were obtained. Finally, a factor Q=0.9 is given to modify the zero pressure height above SWL of QCB, and wave force partial coefficient 1.34 to the design expressions of QCB for anti-sliding, as well as 1.67 for anti-overturning, were presented.

Gravitational Field Excitation from the First Term of Quantum Wilson Loop

In 4-dimensional R-gravity, using the linear and square terms of the expanding expression of the space-time connection, we calculate the possible curvature excitation （order k^4） of gravitational field, which is given by the first term of quantum Wilson loop （w） through two-point Green＇s function of the connection. At the same time using the tree diagram propagators of gravitons, the lowest order （k^4） correction to （w） is also calculated through the graviton self-energy in the term. Under the accuracy condition up to order k^4, we have obtained a complete expression of the excitation contributed from the leading term （w^（2））of （w）.

Identification of key genes responsible for cytokine-induced erythroid and myeloid differentiation and switching of hematopoietic stem cells by RAGE

We utilized a unique culture system to analyze the expression patterns of gene, protein, and cell surface antigen, and the biological process of the related genes in erythroid and myeloid differentiation and switching of hematopoietic stem cells （HSCs） in response to cytokine alterations. Gene-specific fragments （266） identified from five populations of cytokine-stimulated HSCs were categorized into three groups： （1） expressed specifically in a single cell population; （2） expressed in two cell populations, and （3） expressed in three or more populations. Of 145 defined cDNAs, three （2%） were novel genes. Protein two-dimensional gel electrophoresis and flow cytometry analyses showed overlapped and distinguished protein expression profiles in the cell populations studied. Biological process mapping of mRNAs expressed in erythroid and myeloid lineages indicated that mRNAs shared by both lineages attended ＇core processes,＇ whereas genes specifically expressed in either lineage alone were related to specific processes or cellular maturation. Data from this study support the hypothesis that committed HSCs （El4 or G14） cells can still be redirected to develop into myeloid or erythroid cells when erythropoietin （EPO） is replaced with granulocyte-colony stimulating factor （G-CSF） under erythroid-cultured condition or G-CSF with EPO in myeloid-cultured environment, respectively. Our results suggest that genes or proteins co-expressed in erythroid and myeloid lineages may be essential for the lineage maintenance and switching in hematopoiesis.

培养学生物理语言表达能力的策略初探

语言是学习物理的重要工具与载体．物理语言的表达可以分为：概念语言表达、探究语言表达、图表语言表达等．本文以复习课为例，从五个方面谈谈物理语言表达能力的培养策略．

Computational identification and systematic classification of novel GRAS genes in Isatis indigotica

Isatis indigotica Fort., belonging to Cruciferae, is one of the most commonly used plants in traditional Chinese medicine. The accumulation of the effective components of I. indigotica is related with its growth conditions. The GRAS genes are members of a multigene family of transcriptional regulators that play a crucial role in plant growth. Although the activities of many GRAS genes have long been recognized, only in recent years were some of them identified and functionally characterized in detail. In the present study, 41 GRAS genes were identified from 1. indigotica through bioinformatics methods for the first time. They were classified into ten groups according to the classification of Arabidopsis and rice. The characterization, gene structure, conserved motifs, disordered N-terminal domains, and phylogenetic reconstruction of these GRASs were analyzed. Forty-three orthologous gene pairs were shared by I. indigotica and Arabidopsis, and interaction networks of these orthologous genes were constructed. Furthermore, gene expression patterns were investigated by analysis in methyl jasmonate （MeJA）-treated I. indigotica hairy roots based on RNA-seq data. In conclusion, this comprehensive analysis would provide rich resources for further studies of GRAS protein functions in this plant.

Network of tRNA Gene Sequences

A network of 3719 tRNA gene sequences was constructed using simplest alignment. Its topology, degree distribution and clustering coefficient were studied. The behaviors of the network shift from fluctuated distribution to scale-free distribution when the similarity degree of the tRNA gene sequences increases. The tRNA gene sequences with the same anticodon identity are more self-organized than those with different anticodon identities and form local clusters in the network. Some vertices of the local cluster have a high connection with other local clusters, and the probable reason was given. Moreover, a network constructed by the same number of random tRNA sequences was used to make comparisons. The relationships between the properties of the tRNA similarity network and the characters of tRNA evolutionary history were discussed.

Physical conditions for sources radiating a cosh-Gaussian model beam

Based on the coherence theory of diffracted optical field and the model for partially coherent beams,analytical expressions for the cross-spectral density and the irradiance spectral density in the far zone are derived,respectively.Utilizing the theoretical model of radiation from secondary planar sources,the physical conditions for sources generating a cosh-Gaussian(CHG) beam are investigated.Analytical results demonstrate that the parametric conditions strongly depend on the coherence property of sources.When almost coherence property is satisfied in the source plane,the conditions are the same as those for fundamental Gaussian beams;when partial coherence or almost incoherence property is satisfied in the spatial source plane,the conditions are the same as those for Gaussian-Schell model beams.The results also indicate that the variance of cosine parameters has no influence on the conditions.Our results may provide potential applications for some investigations such as the modulations of cosh-Gaussian beams and the designs of source beam parameters.