Mechanical effects of the self-organization of dislocations and related critical characteristics

The effects of the dislocation pattern formed due to the self-organization of the dislocations in crystals on the macroscopic hardening and dynamic internal friction (DIF) during deformation are studied. The classic dislocation models for the hardening and DIF corresponding to the homogeneous dislocation configuration are extended to the case for the non-homogeneous one. In addition, using the result of dislocation patterning deduced from the non-linear dlislocation dynamics model for single slip, the correlation between the dislocation pattern and hardening as well as DIF is obtained. It is shown that in the case of the tension with a constant strain rate, the bifurcation point of dislocation patterning corresponds to the turning point in the stress versus strain and DIF versus strain curves. This result along with the critical characteristics of the macroscopic behavior near the bifurcation point is microscopically and macroscopically in agreement with the experimental findings on mono-crystalline pure aluminum at temperatures around 0.5T(m). The present study suggests that measuring the DIF would be a sensitive and useful mechanical means in order to study the critical phenomenon of materials during deformation.

Kinetic model of continuous-wave flow chemical lasers

In this paper an analysis of the kinetic theory of the continuous-wave flow chemical lasers(CWFCL) is presented with emphasis being laid on the effects of inhomogeneous broadeningon CWFCL's performance. The results obtained are applicable to the case where laser fre-quency is either coincident or incoincident with that of the eenter of the line shape. This rela-tion has been,compared with that of the rate model in common use. These two models are almostidentical as the broadening parameter η is larger than 1. The smaller the value of η, thegreater the difference between the results of these two models will be. For fixed η, the dif-ferences between fhe results of the two models increase with the increase of the frequencyshift parameter ξ. When η is about less than 0.2. the kinetic model can predict exactly the in-homogeneous broadening effects,while the rate model cannot.

Microscopic Model Of Nano-Scale Particles Removal In High Pressure Co2-Based Solvents

A physical model is presented to describe the kinds of static forces responsible for adhesion of nano-scale copper metal particles to silicon surface with a fluid layer. To demonstrate the extent of particle cleaning, Received in revised form equilibrium separation distance (ESD) and net adhesion force (NAF) of a regulated metal particle with different radii (10-300 nm) on the silicon surface in CO2-based cleaning systems under different pressures were simulated. Generally, increasing the pressure of the cleaning system decreased the net adhesion force between spherical copper particle and silicon surface entrapped with medium. For CO2 + isopropanol cleaning system, the equilibrium separation distance exhibited a maximum at temperature 313.15 K in the Equilibrium separation distance regions of pressure space (1.84-8.02 MPa). When the dimension of copper particle was given, for example, High pressure 50 nm radius particles, the net adhesion force decreased and equilibrium separation distance increased with increased pressure in the CO2 + H2O cleaning system at temperature 348.15 K under 2.50-12.67 MPa pressure range. However, the net adhesion force and equilibrium separation distance both decreased with an increase in surfactant concentration at given pressure (27.6 or 27.5 MPa) and temperature (318 or 298 K) for CO2 + H2O with surfactant PFPE COO-NH4+ or DiF(8)-PO4-Na+. (C) 2008 Elsevier B.V. All rights reserved.

输电线巡检机器人行走动力特性与位姿分析

根据跨越超高压输电线路障碍物的类型,提出一种新的双臂自主越障巡检机器人机构。该机器人采用复合轮爪机构在架空地线上连续行走并跨越障碍。由于架空地线呈悬链线状,机器人在连续行走过程中会出现上坡和下坡,对行走动力特性的影响非常明显。在上坡时行走电动机提供驱动力矩,在下坡时行走电动机提供制动力矩,以保持匀速巡线。详细分析了机器人在架空地线上行走时所处的加速、匀速、减速和停止的各个状态,驱动机器人所需的驱动力矩以及它们与机构参数之间的关系,并应用优化方法给出各个状态电动机驱动力矩最小时,机器人机构参数对应的最优解,为巡检机器人的设计和控制系统方案的确定提供了理论依据。

富磷过铝质岩浆体系的实验研究

富磷过铝质岩浆是过铝质岩浆体系中的一个重要类型，它通常以富P，高ASI[铝饱和指数，Al2O3/(Na2O+K2O+CaO)摩尔比值]，贫Fe、Mg、Ca，强烈亏损REE、Th、Y，与稀有金属(W、Sn、Be、Nb、Ta)矿化具有成因联系为特征。富磷过铝质岩浆体系的性状及其演化的地球化学特征、岩浆液态分离、磷酸盐-硅酸盐矿物对平衡对熔体相中磷的制约以及富磷过铝质岩浆－热液体系中微量元素(包括REE)地球化学行为等科学问题尚未得到系统解决，目前更缺乏实验地球化学的直接证据。对上述科学问题的研究、探索，将有助于了解富磷过铝质岩浆体系形成和演化的地球化学特征，有助于揭示磷对微量元素(包括稀有、稀土元素)地球化学行为的影响，这对于理解过铝质岩浆体系成岩、成矿作用过程具有重要的理论和实际意义。 本文以天然钠长花岗岩为初始物，针对上述内容，开展了不同PTX条件下高温高压下实验研究，获得了如下重要认识： 1) 确定了100 MPa条件下磷对过铝质岩浆液相线温度的影响。随着体系中P2O5的含量增大，液相线温度由1.91 wt%P2O5的780 C降至4.83 wt%P2O5的760C、7.71 wt%P2O5的740 C，即体系中每增加1 wt%P2O5，液相线温度降低约7~10 C； 2) 不同PTX条件下的实验产物中均未见不混溶球粒结构、乳滴结构或流动构造，初步推断富磷过铝质岩浆体系中可能不存在单纯由磷引起的岩浆液态分离现象； 3) 锰铝榴石-磷灰石矿物平衡反应制约着形成过铝质初始岩浆中P2O5含量，熔体相中P2O5含量在750 C的0.47~0.80 wt%、830 C的0.35~2.26 wt%范围内。熔体相中的P2O5含量与ASI之间存在二次函数关系(P2O5 wt%=3.5×ASI2-11.3×ASI+9.5 )。锰铝榴石溶解，促使体系中Al2O3活度增大，含锰氟磷灰石的溶解及其端元磷灰石结晶之间的化学平衡，导致熔体相中P2O5的降低，很可能是熔体中P2O5随体系ASI增大而降低的机制。 4) 不同PTX条件下稀有金属元素(W、Sn、Be、Nb、Ta)在流体/熔体相间的分配系数(Dif/m)<<0.1，预示着W、Sn、Be、Nb、Ta强烈富集在富磷过铝质熔体相中。由此，可推测富P过铝质岩浆体系的演化晚期，不太可能分异出富含上述成矿元素的成矿流体。随着岩浆分异演化的进行，残余熔体相中最终导致绿柱石、锆石、锡石、铌钽矿物等矿物饱和结晶，形成有经济意义的花岗岩型或伟晶岩型稀有金属矿床。 5) 不同PTX条件下REE在流体/熔体间的分配系数(DREE)随REE的原子序数增大而逐渐降低，构成右倾的平滑曲线，不存在在Nd-Pm、Gd、Ho-Er处的拐点；Y与Ho在流体/熔体相间分配系数的比值(DY/DHo)约为1，不受体系温度、压力和P2O5含量变化的影响。上述实验结果揭示，富磷过铝质量岩浆演化至岩浆-热液过渡阶段，熔体-流体作用不会导致Y-Ho间的分异，不会引起REE间的分异，因此，富磷过铝质岩浆演化晚期的熔体-流体作用过程不可能是产生稀土“四分组”效应的根本机理。

不同类型量表的线上调查和传统纸笔调查的比较研究

During the past 11 years, with the rapid development of the Internet, more and more psychologists began to realize and take advantage of it, which led to a growing number of psychological test administrated on the internet for data collection. But there were some controversy about the reliability and representatively of this new method. To examine the applicability of the Online Survey and how different types of scales used on the internet, we first reversed the measurement instrument, then from three different levels to investigate the equivalence of online survey and paper-and-pencil assessment, namely, sample level, scale level and item level. Both Classical Test Theory and Item Response Theory were used to analyze the invariance of different types of scale applicability on the internet. The main conclusions of this study could be drawn as follows: 1. In the sample-based study, self-select sample of the online survey was compared to the random sampled sample of paper-and-pencil assessment. The results showed there were no gender difference between them (p>0.05), but the online survey sample was characterized with high qualifications, high-income and younger features (88% of the sample with post-secondary education or above, and 71% aged 20 -29 years). There were significant differences on the scores of all scales between online survey and paper-and-pencil assessment (p<0.01). With demographic controlled, there was no significant difference on the variable of Neurotic between different surveys (p>0.05). 2. With in-group design, it was proved equivalence of the scale of BI (Attitude toward Brand Importance), BT (Attitude toword Brand Switcher), Extraversion, and Conscientiousbess in the compared study in the reliability, construct validity and average scores. 3. On the item level, the results based on the Item Response Theory analysis showed that 2PLM is appropriate for personality and attitude scales. With regard to personality scale, there emerged some items with DIF in the dimensions of Openness to the experience subscale and Agreeable subscale. However, there were no significant differences about the test function. 4. Exploring the psychometrics properties of answer formats of five-, six-, seven-, ten-points, it was showed that different measurement validity between online survey and paper-and-pencil test. It was also described the lower reliability and validity of six-point scale. In conclusion, the results support the application of personality scale online, but for attitude scale, we need to choose prudently.

社会发展与中国人人格变迁——控制测验理论与工具的变异后不同时期的中国人人格差异研究

In non-western society，researches on social development and personality change focused on economic development and social modernization. The present study is aimed at exploring the relationship between the social transformation and personality changes of Chinese people by using so-called indigenous personality measurement of CPAI (Chinese Personality Assessment Inventory). Meanwhile, the influence of CPAI measurement itself and measurement theory were also taken into consideration. In study 1, two sets of CPAI data collected in a 10 year interval were analyzed. At the same time, the CPAI-2 data was analyzed in terms of modernization level of various cities from which the data were collected. However, this study didn’t consider the importance of “equivalence” of the measurement, CPAI. In study 2, we detected DIF (Differential item functioning) across the different period groups to confirm if CPAI was equal to people in different period. In this process, both CTT and IRT method were used. The outcome reminded us that there were some DIF items. In study 3, to make sure that the personality measurement is fair to people in different period, we only saved those items whose DIF effect size lower than 0.01, and used IRT method to estimate test-taker’s personality. Then, cohort analysis was used to explore the pattern of personality change of Chinese people. In study 4, we factor-analyzed the DIF items to find the relation between social transformation and the latent personality variable which were composed of DIF items. From these 4 studies, we could got the following conclusions: (1) The CPAI 22 traits could be divided into two categories, with the changing of age, period and cohort, type I traits didn’t change, they were Logical vs Affective Orientation, Enterprise, Responsibility, Inferiority vs Self-Acceptance, Optimism vs Pessimism, Face, Family, Defensive, Graciousness vs Meanness; While with the changing of age, period and cohort, type II traits changed, they were Leadership, Self vs. Social Orientation, Veraciousness vs Slickness, Traditionalism vs Modernity, Harmony, Renqing, Meticulousness, Extraversion vs Introversion, Emotionality, Practical Mindedness, Internal vs External Locus of Control, Thrift vs Extravagance, Discipline. Meanwhile DIF items measured 5 psychologycial characteristics which changed greatly with the changing of age, period and cohort, they were Life attitude of Cynicism-realism, Psychological maladjustment, Coping style of Waiyuanneifang, Self-efficacy, the value of Individualism. (2) In sum, Chinese people in 1992 were more traditional than those in 2001, and with the 10-year of rapid development, according to the market economy’s needs, Chinese people became more individualism. (3) The DIF method of CTT and IRT were comparable. But, in generally, IRT method was more accurate and valid in detecting DIF as were as estimating personality. (4) The DIF outcomes showed that CPAI had good item validity. Meanwhile, it’s possible to develop a subscale by using CPAI items to assess some psychological characteristics. In this current study, according to their stability and variability, we could divided personality traits and psychological characteristics into 3 categories, and the outcome supported the hypothesis of “Six Factor Model”, these foundings were of some theoretic meanings. Meanwhile, as the relation between social development and personality change being explored, it certain help Chinese people cope with the rapid changing society. In this study, we also found that it’s possible to develop a subscale by using CPAI items to assess obverse personality traits and it had some practical use. Furthermore, the use of different measurement theory and cohort analysis embodied some innovation in methodology.