基于质化理论的高职学生有效学习分析与思考

有效学习是推进以学生为主体的现代化教学的关键,也是体现我国教育改革成效的重要方面。运用质化研究方法,以高职学生为研究对象,通过调查研究,分析影响学生有效学习的关键因素,提出实现学生有效学习的路径和方法。

均质化法在分析非连续碳纳米管增强复合材料微观应力分布规律中的应用

利用具有精确周期性边界条件的均质化理论,用宏微观有限元法分析了非连续碳纳米管呈规则和交错2种排列情况下,纳米管沿管长方向的应力分布规律。为保证传统的连续力学理论的适用性,本文中的碳纳米管采用了用分子动力学方法简化的等效纤维模型。规则排列所得结果与应用Cox剪滞理论及Lauke、Fu等经典理论得出的结果比较发现:除了经典理论中指出的碳纳米管长径比及纳米管体积含量2个因素外,纳米管形状及在基体中的排列方式对材料的力学性质也有较大影响。交错排列的纳米管在复合材料中有较高效率的应力转化和传递能力,碳纳米管的端部间距(2Tf)对应力的分布有较大的影响。结果显示出碳纳米管作为材料增强相的特殊性,证明了均质化理论分析碳纳米管增强复合材料应力分布规律的可行性。

安倍经济学再论——以量化宽松货币政策为中心

安倍经济学的第一支箭宽松货币政策实施几年来,实际经济数据为我们提供了实证分析的条件,但是分析结果表明政策并没有取得明显的效果,与笔者当初进行的理论预测没有太大的出入。黑田央行货币政策(异维度的量化、质化宽松政策)提出了明确的物价提高目标和实现目标的时间,尽管日本银行大量购买风险资产并大量增加基础货币的供给量,但是其通货膨胀目标基本上是无法实现的。货币政策导致了日元大幅度贬值,但是其所导致的企业绩效改善是不均衡的,大型出口企业受益而中小企业受损,没有明显的增加雇用的效果,反而导致了实际工资的下降。股市行情高涨也有助于企业绩效改善,但是这并不是可持续的,已经受到内外因素的影响出现了重大的波动。总之,就货币政策而言,安倍经济学没有取得成功甚至可以说陷于失败的境地。

纱线间距对复合材料拉伸性能的影响

为研究纱线间距对编织复合材料拉伸性能的影响,课题组建立了4组纱线间距的芳纶纤维橡胶基复合材料单胞模型;并通过有限元软件对沿经(纬)纱和纤维束交织2种拉伸方向的单胞模型进行拉伸性能仿真分析。结果表明:随着纱线间距的增加基体和增强相的等效应力逐渐增大,且沿经(纬)纱方向拉伸的等效应力小于纤维束交织方向;通过均质化理论计算出复合材料等效弹性常数,弹性模量随着纱线间距的增加逐渐减小,经(纬)纱方向计算的弹性模量平均高出纤维束交织方向21%。

多重双尺度法在含界面层纳米碳管增强复合材料力学性能分析中的应用

运用多重双尺度法分析了含界面层纳米碳管增强复合材料的力学性质。首先利用分子结构力学导出纳米框架结构的有效力学性质,取纳米分子结构中的框架结构为特征单元体,用一次均质化理论得到纳米碳管的有效弹性模量,将该纳米碳管等效为连续空心圆筒,与损伤界面组成新的特征单元体再进行第二次均匀化得到新的增强体,计算过程中在界面与基体交界处引入过渡的粘接单元描述可能出现的界面脱粘过程,最后将新增强体和基体组成的特征体积单元进行第三次均匀化得到纳米碳管增强复合材料的有效力学性质,分析了界面特性对宏观有效力学性能的影响。数值结果表明,界面层长厚比及界面层杨氏模量的变化对碳纳米管增强复合材料的弹性模量影响较大,界面相的存在不容忽视。所得结果与经典的Mori-Tanaka法和Halpin-Tsai法进行比较,取得了较好的一致性,验证了多重双尺度法的有效性。

多尺度随机性有限元在线性椭圆问题中的应用

非均质材料的力学性能在宏观和微观的尺度上都具有一定的不确定性,通过构建数学模型来研究、预测非均质材料的力学性能具有较高的理论价值和实际工程意义,多尺度随机有限元法正是在这一宏观背景下提出.以均值化理论及两尺度模型为基础,结合随机有限元谱方法,旨在完整地模拟随机性周期分布的线性椭圆问题.模型藉由对微观尺度下对代表体元的微小摄动数值分析,求出随机参数的宏观等效值;并结合KL分解、混沌多项式展开考虑求解过程中的随机性问题,得到的数值结果和已有的蒙特卡洛方法有较高的吻合.分析结果显示出随着分析维度和阶数的提高,结果不断逼近真实解.并进一步指出,在兼顾效率和精度的情况下,一维分析时所取的维度数和阶数的极限.

Chemical bonding and elastic properties of quaternary arsenide oxides YZnAsO and LaZnAsO investigated by first principles

The structural parameters, chemical bonding and elastic properties of the tetragonal phase quaternary arsenide oxides YZnAsO and LaZnAsO were investigated by using density-functional theory （DFT） within generalized gradient approximation （GGA）. The GGA calculated structural parameters are in agreement with the experimental results. Population analysis suggests that the chemical bonding in YZnAsO and LaZnAsO can be classified as a mixture of ionic and covalent characteristic. Single-crystal elastic constants were calculated and the polycrystalline elastic modules were estimated according to Voigt, Reuss and Hill＇s approximations （VRH）. The result shows that both YZnAsO and LaZnAsO are relatively soft materials exhibiting ductile behavior. The calculated polycrystalline elastic anisotropy result shows that LaZnAsO is more anisotropy in compressibility and YZnAsO is more anisotropy in shear.

Reactions of Group V Metal Atoms with Hydrogen Sulfide： Argon Matrix Infrared Spectra and Theoretical Calculations

The reaction of laser-ablated vanadium, niobium and tantalum atoms with hydrogen sulfide has been investigated using matrix isolation FTIR and theoretical calculations. The metal atoms inserted into the H-S bond of H2S to form the HMSH molecules （M=V, Nb, Ta）, which rearranged to H2MS molecules on annealing for Nb and Ta. The HMSH molecule can also further react with another H2S to form the H2M（SH）2 molecules. These new molecules were identified on the basis of the D2S and H234S isotopic substitutions. DFT （B3LYP and BPW91） theoretical calculations are used to predict energies, geometries, and vibrational frequencies for these novel metal dihydrido complexes and molecules. Reaction mechanism for formation of group V dihydrido complex was investigated by DFT internal reaction coordinate calculations. The dissociation of HVSH gave VS＋H2 on broad band irradiation and reverse reaction happened on annealing. Based on B3LYP calculation releasing hydrogen from HVSH is endothermic only by 13.5 kcal/mol with lower energy barrier of 16.9 kcal/mol.

Photocatalytic performance of TiO_2 nanocrystals with/without oxygen defects

To investigate the role of oxygen defects on the photocatalytic activity of TiO2,the TiO2 nanocrystals with/without oxygen defects are successfully synthesized by the hydrothermal and sol‐gel methods,respectively.The as‐prepared TiO2 nanocrystals with defects are light blue and the absorption edge of light is towards the visible light region(~420 nm).Raman and X‐ray photoelectron spectroscopy(XPS)measurements all confirm that the concentration of oxygen vacancies in the TiO2 synthesized by the sol‐gel method is less than that synthesized through the hydrothermal route.The introduction of oxygen defects contributes to a new state in the band gap that narrows the band gap,which is the reason for the extension of light absorption into the visible light region.The photocurrent results confirm that this band‐gap narrowing enhances the photocurrent response under simulated solar light irradiation.The TiO2 with oxygen defects shows a higher photocatalytic activity for decomposition of a methylene blue solution compared with that of the perfect TiO2 sample.The photocatalytic mechanism is discussed based on the density functional theory calculations and photoluminescence spectroscopy measurements.

Prediction of Transverse Permeability for Unidirectional Fiber Tows Based on the Homogenization Theory

The transverse permeability of unidirectional fiber tows is calculated using homogenization method.Each fiber tow consisting of 21 filaments is arranged in uniform square packing.Stokes governing equation is analogized with Lame equation used in the linear elasticity problem and is solved by the finite element code ANSYS.The prediction for transverse permeability of unidirectional fiber obtained by the homogenization approach is compared with other analytical methods.The result shows a good agreement with Kozeny-Carman equation and Gebart square packing model.A model for nonuniform fiber distribution and measurement technology are proposed.It can be found that the experimental result is in excellent agreement with predicted permeability in the nonuniform distribution model.

Neutron （Magnetic Isotope） Catalysis for Example Isotopes 24,25,26Mg in Cells E. Coli

We offered the new theory of neutron （magnetic isotope） catalysis. For the first time it was shown that the number of neutrons in the atom, which have anomalous magnetic effect, have a great influence on the chemical properties. Our proposed theory of neutron （magnetic isotope） catalysis takes into account the influence of the magnetic field on the catalytic processes.

Application of the third theory of quantification in coal and gas outburst forecast

The essential principles of the third theory of quantification are discussed, the concept and calculated method of reaction degree are put forward which extend the ap- plying range and scientificalness of the primary reaction. Taking the Zhongmacun Mine as example, on the base of analyzing the rules of gas geology synthetically and travers- ing the geological factors infecting coal and gas outburst, the paper adopts the method of combining carving up statistical units with the third theory of quantification, screens out 8 sensitive geological factors from 11 geological indexes and carries through the work of gas geology regionalism to the exploited area of Zhongmacun according to the researching result. The practice shows that it is feasible to apply the third theory of quantification to gas geology, which offers a new thought to screen the sensitive geo- logical factors of gas outburst forecast.

Effect of vacancy defects on electronic properties and activation of sphalerite(110) surface by first-principles

The electronic properties of sphalerite(110) surface with Zn-vacancy and S-vacancy were calculated by using density-functional theory,and the effects of vacancy defect on the copper activation of sphalerite were investigated.The calculated results indicate that surface state occurs in the band gap of Zn-vacancy sphalerite,which is from the contribution of S 3p orbital at the first layer of the surface.The presence of S-vacancy results in surface state appearing near the Fermi level and the bottom of conductor band,which are composed of S 3p and Zn 4s orbital,respectively.The surface structure of Zn-vacancy sphalerite is more stable than S-vacancy surface due to the occupation of Zn-vacancy by Cu atoms;hence,the substitution reaction of Cu for Zn vacancy is easier than the substitution of Cu for Zn atoms with S-vacancy surface.

Does landscape structure contribute to the long-term maintenance of generalized parasitism in cowbirds?

Unlike most brood parasites, several species of cowbird (Molothrus) are generalists that parasitize multiple host species across their range and within the same communities; likewise, there is little evidence that individuals within a population specialize on host species. This situation has variously been attributed to the recency of cowbird evolution (the 'evolutionary lag' hypothesis) or to hidden costs of rejection by hosts (the 'equilibrium' hypothesis). Both hypotheses have some support as cowbirds are indeed a relatively young clade compared with more specialized cuckoos and cowbirds are capable of sophisticated behaviors such as retaliation against rejection ('mafia' behaviors) that would select for acceptance of cowbird eggs. Nevertheless, many species in the Americas have evolved specialized defenses against cowbird parasitism, almost all of which live in more open habitats (e. g., grasslands, shrublands, riparian strips), which indicates that coevolutionary processes can operate in ways that select for host defenses in spite of cowbird counterdefenses. We propose that the structure of landscapes in North America may explain why forest-nesting birds lack defenses against parasitism and reinforce the long-term maintenance of generalized brood parasitism in cowbirds. Because cowbirds require open habitats in which to feed, they are rare or absent in large forest tracts, which dominate much of the forest cover of the Americas. These tracts act as 'source habitats' that produce surplus young that recolonize populations in smaller, fragmented forest patches in which rates of both cowbird parasitism and nest predation are very high ('sink' habitats). Evolution of antiparasite adaptations would be very slow in this situation because most hosts are produced in areas where there is little or no cowbird parasitism. In addition, the interplay of host breeding dispersal, source-sink metapopulation dynamics, and fragmented forest habitat could further deter the evolution of host defenses against parasitism. Therefore, as long as large forest tracts remain widespread in North America, most forest birds will likely continue to lack defenses against cowbird parasitism, guaranteeing a steady supply of na ve hosts in forest habitats, even in fragmented landscapes. This situation will, in turn, favor host generalist cowbirds that actively avoid more open habitats in favor of parasitizing forest bird communities. These forest communities may also act as source populations for cowbirds, which might pump surplus generalist cowbirds into more open habitats further slowing the coevolutionary process. As long as large forest tracts are a common part of the landscape, generalist parasitism may persist indefinitely.

How to Determine the Upgrading Opportunities for Industries： Theory, Method and Policy

Industrial upgrading and transformation is important for China to transform its way of development. To accomplish this task effectively, we need to identify industries with potential comparative advantage. Using the latest data on international trade of products, this paper verifies the premise of heterogeneity of product space of the evolutionary theory of comparative advantage, and analyses the evolution of product space of China and most countries in the world. The paper makes predictions on China ＂s industries with potential comparative advantage in near terms using the product space theory, and carries out thorough discussion on the evolutionary track of industries under different proximity thresholds. The basic conclusion is that even as China＇s number of industries with comparative advantage is larger than the global average, its industrial upgrading capacity is limited, as it has fewer industries with potential comparative advantage and lower sustainability in the current sectors than the world average. China faces a dilemma in the process of industrial upgrading, as a rapid upgrading would cause a shock to current economic growth, and a slow one would not maintain sustainable growth. With limited industrial upgrading capacity, the best structure adjustment and upgrading strategy is to give full play to the advantage of China＇s industrial diversification and combination to achieve an inclusive upgrading.

Fully Quantized Theory of Six-Wave Mixing with Matter Waves

We show that Wu-Yang theory of fully quantized four-wave mixing can be generalized to the six-wave mixing and derive the analytical solution of the coupled equations describing the quantum dynamics of six-wave mixing.

Quasiparticle Spectrum of Quantum Degenerate Fermi Gas in the Presence of Self—Consistent Magnetization Field

In this paper, we develop a systematic and simple method to derive quasiparticle spectrum of the quantum degenerate Fermi gases within the framework of Hartree–Fock–Bogoliubov theory which turns a general nonlinear two-body interaction Hamiltonian into a bilinear Hamiltonian by introducing certain self-consistent mean fields. Applying the approach, we obtain the quasi-particle spectrum of the model describing the superfluid phase transition that arises when a Feshbach resonance pairing occurs in a dilute Fermi gas in the presence of the magnetization fields and . When the gap parameter Δ is smaller than one or both of the magnetization fields, the spectrum manifests roton-type structure dramatically different from the spectrum in the absence of the magnetization fields.

Timelessness and Time Dependence of Human Consciousness From a Scientific Western Viewpoint

Eastern philosophy and western science have convergent and divergent viewpoints for their explanation of consciousness. Convergence is found for the practice of meditation allowing besides a time dependent consciousness, the experience of a timeless consciousness and its beneficial effect on psychological wellbeing and medical improvements, which are confirmed by multiple scientific publications. Theories of quantum mechanics with non-locality and timelessness also show astonishing correlation to eastern philosophy, such as the theory of Penrose-Hameroff （ORC-OR）, which explains consciousness by reduction of quantum superposition in the brain. Divergence appears in the interpretation of the subjective experience of timeless consciousness. In eastern philosophy, meditation at a higher level of awareness allows the personal experience of timeless and non-dual consciousness, considered as an empirical proof for the existence of pure consciousness or spirituality existing before the material world and creating it by design. Western science acknowledges the subjective, non-dual experience, and its multiple beneficial effects, however, the interpretation of spirituality designing the material universe is in disagreement with the Darwinian Theory of mutation and selection. A design should create an ideal universe without the injustice of 3% congenital birth defects and later genetic health problems. The western viewpoint of selection is more adapted to explain congenital errors. The gap between subjectivity and objectivity, the mind-body problem, is in eastern philosophy reduced to the dominance of subjectivity over objectivity, whereas western science attributes equal values to both. Nevertheless, there remains an astonishing complementarity between eastern and western practices.

A method of shadow puppet figure modeling and animation

To promote the development of the intangible cultural heritage of the world, shadow play, many studies have focused on shadow puppet modeling and interaction. Most of the shadow puppet figures are still imaginary,spread by ancients, or carved and painted by shadow puppet artists, without consideration of real dimensions or the appearance of human bodies. This study proposes an algorithm to transform 3D human models to 2D puppet figures for shadow puppets, including automatic location of feature points, automatic segmentation of 3D models, automatic extraction of 2D contours, automatic clothes matching, and animation. Experiment proves that more realistic and attractive figures and animations of the shadow puppet can be generated in real time with this algorithm.

Influence of Cl substitution on the electronic structure and catalytic activity of ceria

Cl-containing cerium dioxide(Ce O2) catalysts have been found to exhibit unique catalytic activities. In the present work, using density functional theory calculations with the inclusion of on-site Coulomb correction, we systematically studied the effect of Cl on the physicochemical properties of Ce O2 surfaces by substituting one subsurface O with Cl. The calculated results show that substituting an O atom with a Cl atom results in structural distortion and the reduction of one surface Ce4+ cation to Ce3+. The protruding Ce3+ cation greatly improves the adsorption energy of O2 to produce an active O2- species, and maintains the catalytic oxidation cycle of CO on Ce O2(110). These results may help us obtain a better understanding of Cl-ceria interacting systems and provide some guidance for the design of effective Ce O2-based catalysts.