儿童的记忆与认知——1.4—6岁儿童对长度序列图形和数序列图形记忆特点的初步探讨

本研究结果显示幼儿对序列图形的记忆随着认知的发展而发展。他们的记忆策略的发展可分为无策略阶段,中间阶段和有策略阶段。长度序列图形的记忆优于数序列图形的记忆。经过储存过程,有些儿童画图再现成绩的总趋势不是下降而是有不同程度的提高,但个别差异相当大。

摇摆式凸轮磨床靠模的形数特征

介绍了圆族包络法加工摇摆式凸轮磨靠模的计算原理和加工要点,证明了靠模的"不对称"和"最大升程不相等"的形数特征,并对由凸轮磨砂轮半径变化引起的工件升程误差的量值和分布给出了计算方法。

数数与计数中的发现(下)

(四)在上述的数数与计数教学活动中,我们把形和数自然地结合起来了。下面我们将看到,这种形数结合还能引导出很多结果。下面的两图表示不同的数数与计数方法(图9、图10)

指导学生找赛题思路六法

随着奥林匹克活动的普及和数学活动课的开展,小学数学竞赛熔知识性、趣味性、技巧性于一炉的题目大量问世。一些同学面对赛题苦思无路,迂回在常规思维中,只凭脑海中储存的题目模式。如何指导学生寻觅赛题思路,我们采用了以下六种辅助方法。 1、画涂试试。

Influence of Shenqing Recipe on Morphology and Quantity of Colonic Interstitial Cells of Cajal in Trinitrobenzene Sulfonic Acid Induced Rat Colitis

Objective To observe the influence of Shenqing Recipe (SQR), a kind of Traditional Chinese Medicine, on the morphology and quantity of colonic interstitial ceils of Cajal (ICC) in trinitrobenzene sulfonic acid (TNBS)-induced rat colitis, and to investigate the possible mechanism of SQR in regulating intestinal dynamics. Methods Sixty rats were randomly divided into normal control, model Ⅰ , model Ⅱ, mesalazine, and high-dose, and low-dose SQR groups with 10 rats in each group. TNBS (10 mg) dissolved in 50% ethanol was instilled into the lumen of the rat colon of the latter five groups to induce colitis. On the 4th day after administration of TNBS, each treatment group was administered one of the following formulations by enteroclysis gavage once a day for 7 days: 600 mg·kg^-1·d^-1 mesalazine, 2.4g^-1·d^-1 SQR, and 1.2g^-1·d^-1 SQR. Model Ⅱ rats received normal saline solution. After 7 days colonic samples were collected. While the colonic samples of model I group were collected on the 3rd day after TNBS administered. Ultrastructure of ICC in the damaged colonic tissues was observed with transmission electron microscope. Expression of c-kit protein in colonic tissue was determined by immunohistochemical staining and Western blot. Results The ultrastructure of colonic ICC in the rat model of TNBS-induced colitis showed a severe injury, and administration of SQR or mesalazine reduced the severity of injury. Similarly, the expression of c-kit protein of TNBS-induced colitis rat model was significantly decreased compared with the normal control group (P〈0.05). Treatment with SQR or mesalazine significantly increased the expression of c-kit protein compared with the administration of control formulations (P〈0.05), especially the high-dose SQR group. Conclusion SQR could alleviate and repair the injured ICC, and improve its quantity, which might be involved in regulating intestinal motility.

Spherical parametrization of genus-zero meshes by minimizing discrete harmonic energy

The problem of spherical parametrization is that of mapping a genus-zero mesh onto a spherical surface. For a given mesh, different parametrizations can be obtained by different methods. And for a certain application, some parametrization results might behave better than others. In this paper, we will propose a method to parametrize a genus-zero mesh so that a surface fitting algorithm with PHT-splines can generate good result. Here the parametrization results are obtained by minimizing discrete har- monic energy subject to spherical constraints. Then some applications are given to illustrate the advantages of our results. Based on PHT-splines, parametric surfaces can be constructed efficiently and adaptively to fit genus-zero meshes after their spherical parametrization has been obtained.

Influence of Rotor Structure and Number of Phases on Torque and Flux Weakening Characteristics of V-Shape Interior PM Electrical Machine

This paper investigates the influence of the rotor structure on torque and flux weakening region of V-shape IPM （interior permanent magnet） machine from TOYOTA PRIUS type. More specifically, always keeping the same magnet volume, the effect of the open angle between the two magnet segments of each V-shape pole on the machine performance is studied. Moreover, in order to examine the impact of phase number on the machine characteristics, PRIUS structure is transformed into 5-phase machine of the same type and dimensions. As well, an optimization procedure is carried out to determine the optimal open angle according to main characteristics. The previous investigation is done by using a free FEM （finite elements methods） program coupled with another optimization program. Using this obtained methodology, the study analyzes for 3-phase and 5-phase machine the average and pulsation of torque, cogging torque, phase EMF （electro-motive force）, constant power operating capability.

Analytical solutions for a uniformly loaded circular plate with clamped edges

A bi-harmonic potential function was constructed in this study. Love solution was employed to obtain analytical solutions of uniformly loaded plates with two different types of clamped edges. The treatment of clamped boundary conditions was the same as that adopted by Timoshenko and Goodier (1970). The analytical solution for the first type of clamped boundary condition is identical with that obtained by Luo et al.(2004), and the solutions for both types were compared with the FEM results and the calculations of thin plate theory.

The shape character and development stage of nebkha

Based on statistical analysis on morphological data of nebkhas surveyed in the Hotan River Basin,Xinjiang, the changing regularity and characters of nebkhas’ morphology in different development stageshave been discussed. Results indicate that there exist better correlation among length, width and altitudeof all kinds of nebkhas, but there are certain various shape characters in different nebkhas and the sametype of nebkhas in differential development stages. On account of analysis on mathematical imitation ofnebkhas’ shape characters, regional ecological environmental and aeolian characters, the development ofthe nebkha can be divided into a growing stage, a stabilizing stage and a declining stage.

Estimation of the van Genuchten Soil Water Retention Properties from Soil Textural Data

The van Genuchten (vG) function is often used to describe the soil water retention curve (SWRC) of unsaturated soils and fractured rock. The objective of this study was to develop a method to determine the vG model parameter m from the fractal dimension. We compared two approaches previously proposed by van Genuchten and Lenhard et al. for estimating m from the pore size distribution index of the Brooks and Corey (BC) model. In both approaches we used a relationship between the pore size distribution index of the BC model and the fractal dimension of the SWRC. A dataset containing 75 samples from the UNSODA unsaturated soil hydraulic database was used to evaluate the two approaches. The statistical parameters showed that the approach by Lenhard et al. provided better estimates of the parameter m. Another dataset containing 72 samples from the literature was used to validate Lenhard's approach in which the SWRC fractal dimension was estimated from the clay content. The estimated SWRC of the second dataset was compared with those obtained with the Rosetta model using sand, silt, and clay contents. Root mean square error values of the proposed fractal approach and Rosetta were 0.081 and 0.136, respectively, indicating that the proposed fractal approach performed better than the Rosetta model.

Hybrid Strategy of Particle Swarm Optimization and Simulated Annealing for Optimizing Orthomorphisms

Orthomorphism on F2^n is a kind of elementary pemmtation with good cryptographic properties. This paper proposes a hybrid strategy of Particle Swarm Optimization （PSO） and Sirrmlated Annealing （SA） for finding orthomorphisrm with good cryptographic properties. By experiment based on this strategy, we get some orthorrorphisrm on F2^n = 5, 6, 7, 9, 10） with good cryptographic properties in the open document for the first time, and the optirml orthorrrphism on F found in this paper also does better than the one proposed by Feng Dengguo et al. in stream cipher Loiss in difference uniformity, algebraic degree, algebraic irrarnity and corresponding pernmtation polynomial degree. The PSOSA hybrid strategy for optimizing orthomerphism in this paper makes design of orthorrorphisrm with good cryptographic properties automated, efficient and convenient, which proposes a new approach to design orthornorphisrm.

A Brief Report of Graphic Explanations for Generalized Potential Temperature in the Non-Uniformly Saturated Atmosphere

Compared to potential temperature （θ） in the dry atmosphere and equivalent potential temperature （θc） in the saturated atmosphere, generalized potential tem- perature （θ＂） has already proven a better thermodynamic parameter in describing the non-uniformly saturated real atmosphere. To add otherwise absent graphic explanations, this paper first presents the physical definition of θ through a tephigram. Then, the utility of the measurement in identifying and forecasting the locations of precipita- tion maxima and heat wave areas with diagnostic com- parison studies and traditionally used thermodynamic parameters is shown.

Qualitative Algebra and Graph Theory Methods for Dynamic Trend Analysis of Continuous System

Qualitative algebraic equations are the basis of qualitative simulation,which are used to express the dynamic behavior of steady-state continuous processes.When the values and operation of qualitative variables are redefined,qualitative algebraic equations can be transformed into signed direct graphs,which are frequently used to predict the trend of dynamic changes.However,it is difficult to use traditional qualitative algebra methods based on artificial trial and error to solve a complex problem for dynamic trends.An important aspect of modern qualitative algebra is to model and characterize complex systems with the corresponding computer-aided automatic reasoning.In this study,a qualitative affection equation based on multiple conditions is proposed,which enables the signed di-rect graphs to describe complex systems better and improves the fault diagnosis resolution.The application to an industrial case shows that the method performs well.

Development of Heat Transfer Coefficient and Friction Factor Correlations for Serrated Fins in Water Medium using CFD

Abstract： The most popularly used fin types in compact heat exchangers are the serrated fins, wavy fins, louvered fins and plain fins. Amongst these fin types the serrated fins assume lot of importance due to its enhanced thermo-hydraulic performance. Thermo-hydraulic design of CHEs （Compact heat exchangers） is strongly dependent upon the predicted/measured dimensionless performance （Colburnj factor and Fanning friction vs. Reynolds number） of heat transfer surfaces. This paper describes the numerical analysis to study the heat transfer coefficient and friction factor of Serrated fins in water medium. CFD （Computational fluid dynamics） methodology has been used to develop the single phase water heat transfer coefficient and friction factor correlations for serrated fins using ANSYS Fluent 14.5. The results are compared with previous air-cooled models and experimental results of water. The water cooled CFD analysis results shows that the Prandtl number has a large effect on the Nusselt number of the serrated fin geometry. Finally, the generalized correlations are developed for serrated fins taking all geometrical parameters into account. This numerical estimation can reduce the number of tests/experiments to a minimum for similar applications.

Study on the Precise Location of the Xinjiang Yutian M_S7.3 Earthquake

The seismic waveform of the Yutian Ms7. 3 earthquake, Xinjiang on February 12, 2014 was recorded clearly and completely by the Digital Seismic Networks of Xinjiang, Qinghai, Tibet, and Xinjiang Hotan array, so the method of joint location by regional seismic network and seismic array can be used to accurately determine the earthquake source location. The following technologies were used in the process of location： （ 1 ） We selected seismic stations equally located around the epicenter of the Ms 7. 3 earthquake with an average interval of about 15 degrees in the initial location. （2） The recording waveforms of Yutian seismic station were rotated to the radial and tangential directions to precisely obtain the arrival time of S-waves to determine the epicentral distance. （ 3） The velocity model was used in the determination of location of the epicenter, based on the historical records of earthquakes in the area within a radius of 1.0 ° from the source as the center, and the velocity model is obtained after re-fitting and calibration. （4） Based on the waveform records of the Hotan seismic array, the method of waveform beaming was used to determine the azimuths and perform the correction of the epicenter location with these azimuths. （5） The deterministic method was used to measure the source depth. Finally, it is concluded that the Yutian Ms 7. 3 main shock hypocenter location is 36. 197°N, 82. 467°E, focal depth 12km and original time 17：19：48. 2 μm. February 12, 2014.

隐藏的数字

正方形被曲线分割成了若干块,每块上都有一个数字,请你认真观察每个图形和数字,找出规律,在黑色图形中填上适当的数,该填几呢?

智能型行车预警装置

智能型行车预警装置能将交通事故消灭在“萌芽”状态。它可以在危险出现时提前4—5秒钟发出声、光、图形和数字警报等信息,提醒驾驶员迅速采取措施。

Generic twisted T -adic exponential sums of binomials

The twisted T -adic exponential sum associated with xd + λx is studied. If λ = 0, then an explicitarithmetic polygon is proved to be the Newton polygon of the C-function of the twisted T-adic exponential sum.It gives the Newton polygons of the L-functions of twisted p-power order exponential sums.

Deformation quantization and noncommutative black holes

This short paper is based on the talk on the conference Operator Algebras and Related Topics held on July 23-27, 2010, Beijing. The author surveys recent developments of the noncommutative gravity in joint works with Chaichian, Tureanu, Sun, Wang, Xie and Zhang.

f-Harmonic Morphisms Between Riemannian Manifolds

f-Harmonic maps were first introduced and studied by Lichnerowicz in 1970.In this paper,the author studies a subclass of f-harmonic maps called f-harmonic morphisms which pull back local harmonic functions to local f-harmonic functions.The author proves that a map between Riemannian manifolds is an f-harmonic morphism if and only if it is a horizontally weakly conformal f-harmonic map.This generalizes the well-known characterization for harmonic morphisms.Some properties and many examples as well as some non-existence of f-harmonic morphisms are given.The author also studies the f-harmonicity of conformal immersions.