ADAPT<Superscript>IT</Superscript>: Tools for training design and evaluation

This article describes a set of computerized tools that support the design and evaluation of competency-based training programs. The training of complex skills such as air traffic control and process control requires a competency-based approach that focuses on the integration and coordination of constituent skills and transfer of learning. At the heart of the training are authentic whole-task practice situations. The instructional design tools are based on van Merriënboer's 4C/ID^* methodology (1997). The article describes a training design tool (Core) that supports the analysis and design for competency-based training programs and an evaluation tool (Eval) that supports the subsequent revision of this training design.     

Effects of astaxanthin on oxidative stress induced by Cu<Superscript>2+</Superscript> in prostate cells

Astaxanthin (AST), a carotenoid molecule extensively found in marine organisms and increasingly used as a dietary supplement, has been reported to have beneficial effects against oxidative stress. In the current paper, the effects of AST on viability of prostate cells were investigated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay; cell apoptosis and intracellular reactive oxygen species (ROS) levels were determined by flow cytometry; the mitochondrial membrane potential (MMP) was measured by fluorospectrophotometer; and activities of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were evaluated by a detection kit. The results show that copper ion (Cu²⁺) induced apoptosis, along with the accumulation of intracellular ROS and MDA, in both prostate cell lines (RWPE-1 and PC-3). AST treatments could decrease the MDA levels, increase MMP, and keep ROS stable in RWPE-1 cell line. An addition of AST decreased the SOD, GSH-Px, and CAT activities in PC-3 cell line treated with Cu²⁺, but had a contrary reaction in RWPE-1 cell lines. In conclusion, AST could contribute to protecting RWPE-1 cells against Cu²⁺-induced injuries but could cause damage to the antioxidant enzyme system in PC-3 cells.     

Preparation and characterization of high purity enriched <Superscript>10</Superscript>B boric acid via anti-solvent recrystallization

Self-made enriched ¹⁰B boric acid as raw material was purified by recrystallization. The effects of final crystallization temperature, crystallization time, stirring speed, crystallization frequency and other factors on the purity were investigated. The appropriate operating condition was that the final crystallization temperature and time were 5°C and 10 h respectively under a low-speed stirring for crystallizing twice, which would make the purity and yield of boric acid reach 99.94% and 95.36%, respectively. Taking this as foundation, recrystallization process was optimized with acetone as anti-solvent, whose amount was the most important index. The boric acid solution was added into acetone and recrystallized under the same condition, and the purity and yield of boric acid would reach 99.98% and 99.61%, respectively. The product detected by XRD was confirmed as boric acid crystal. Main ion concentration in the product was detected by ICP, which basically met the national standard of high purity. Crystal morphology of boric acid was observed by SEM.     

Three AMIGO<Superscript>3</Superscript>s: Using “Anchored modular inquiry” to help prepare future teachers

We discuss three case studies associated with Vanderbilt’s PT3 (Preparing Tomorrow’s Teachers to Use Technology) grant. The studies explore some initial effects of attempts to enhance the education of preservice teachers in three areas: (a) How People Learn, (b) Mathematics, and (c) Adolescent Psychology. The case studies to be described each build on Vanderbilt’s AMIGO³ project, which involves technology architecture for flexible modular design that was developed to be consistent with principles of How People Learn. Three different research teams used the AMIGO³ architecture and rationale to design, implement, and study their own courses. All teams agreed on some basic guidelines, but then proceeded independently of one another. The purpose of this report is to compare similarities and differences in the experiences of the teams. The PT3 group: Primary Investigator—John Bransford; Project Director—Bob Plants; How People Learn Course—John Bransford, Nancy Vye, Kay Burgess, and Sean Brophy; Adolescent Psychology—Helen Bateman, and Christopher J. Bateman; Mathematics—Paul Cobb, Chrystal Dean, and Lori Tyler; Development Team—Tim Altman, Jason Adair, Hank Clark, Bill Corbin, John Harwood, Elliott Mitchell, and Carolyn Stalcup. Vanderbilt PT3 Partners: AACTE, Apple Computers, Bankstreet College, Concord Consortium, Little Planet Software, Middle Tennessee University, University of Illinois-Chicago, University of Minnesota, and University of Vermont. Research presented in this article was supported by grants: The Department of Education Preparing tomorrow’s teachers to use technology (PT3) Catalyst grant, #P342A990348, The National Science Foundation VaNTH Bioengineering grant, #EEC 9876363, and the Atlantic Philanthropic Association K-12 Learning Consortium (no assigned grant number).     

Kinetics of the reaction between boron trifluoride methanol complex and sodium methoxide to produce enriched <Superscript>10</Superscript>B methylborate

The relation of boron trifluoride concentration with conductivity in boron trifluoride methanol solution (BF₃-CH₃OH)was power exponent fitted in low concentration range. The kinetics of the reaction between boron trifluoride methanol complex and sodium methoxide to produce enriched ¹⁰B methylborate was proposed based on a detailed mechanism study, and was verified by acid-base titration method and conductivity method. It was found that this reaction is first order reaction and the rate constant is 0.022 min^?1 at 338 K(65 °C), the activity energy is 65 kJ/mol. In addition, it was found that the conductivity method is more feasible to measure the kinetic curve than acid-base titration method.     

A new approach to simulate the supporting arch in a tunnel based on improvement of the beam element in FLAC<Superscript>3D</Superscript>

The beam element in FLAC^3D can be used to simulate the supporting arch in a tunnel. However, this approach has the shortcoming of its constitutive model, and the bearing capacity and surrounding rock supporting effect of the arch model will be significantly exaggerated. To simulate the supporting arch in tunnel engineering well, a new approach is proposed by improving the beam element. The yield criterion of the beam element subjected to compression-bending loads is established based on the now-available bearing capacity formulas of some typical compression-bending sections. In addition, the yield criterion is embedded in the FLAC^3D main program by using the FISH language, and the modification of the beam model and the yielding failure simulation of the supporting arch are finally implemented. Compression-bending tests and roadway tunnel arch support example analysis were performed. The results are as follows: (1) the modified model showed the dependence of the bending moment and axial force on the yielding action of the beam element under compression-bending loads; (2) the implementation program is effective and sensitive; (3) the computing deviation caused by the shortcomings of the original beam element model was effectively suppressed, the mechanical behavior and surrounding rock supporting laws exhibited by the arch model were much closer to reality, and the calculation accuracy and design reliability were improved by the new simulation approach.     

A quadratic programming method for optimal degree reduction of Bezier curves with G^1-continuity

This paper presents a quadratic programming method for optimal multi-degree reduction of Bézier curves with G1-continuity. The L2 and l2 measures of distances between the two curves are used as the objective functions. The two additional parameters, available from the coincidence of the oriented tangents, are constrained to be positive so as to satisfy the solvability condition. Finally, degree reduction is changed to solve a quadratic problem of two parameters with linear constraints. Applica     

Study on the effect of doxorubicin on expressions of genes encoding myocardial sarcoplasmic reticulum Ca<Superscript>2+</Superscript> transport proteins and the effect of taurine on myocardial protection in rabbits

To investigate the effect of doxorubicin(DOX) on gene expression of the myocardial sarcoplasmic reticulum (SR) Ca²⁺ transport proteins and the mechanism of taurine(Tau) protecting cardiac muscle cells, 9 rabbits were injected with DOX, 8 rabbits with DOX and Tau, and 9 rabbits with normal saline. Cardiac function, concentration of calcium in cardiomycocytes (Myo [Ca²⁺] _i ), activity of SR Ca²⁺-ATPase (SERCA2a), level of SERCA2a mRNA and Ca²⁺ released channels (RYR2) mRNA were detected. The left ventricle tissues were observed by electron microscopy. The results showed that cardiac index, left ventricular systolic pressure, activity of SR Ca²⁺-ATPase and level of SERCA2a mRNA decreased, while Myo[Ca²⁺] _i increased in DOX-treated rabbits. DOX could not affect the level of RYR2 mRNA. Tau intervention could alleviate the increase of left ventricular diastolic pressure, Myo[Ca²⁺] _i and the decrease of SERCA2a mRNA induced by doxorubicin. The results suggested that downregulation of SERCA2a gene expression was an important mechanism of DOX-induced cardiomyopathy and that Tau could partially improve the heart function by reducing calcium overload and alleviating downregulation of SERCA2a mRNA.     

A note on the Marcinkiewicz integral operators on Fp^a,q

In this paper, we shall prove that the Marcinkiewicz integral operator #n, when its kernel Ω satisfies the L^1-Dini condition, is bounded on the Triehel-Lizorkin spaces. It is well known that the Triehel-Lizorkin spaces are generalizations of many familiar spaces such as the Lehesgue spaces and the Soholev spaces. Therefore, our result extends many known theorems on the Marcinkiewicz integral operator. Our method is to regard the Marcinkiewicz integral operator as a vector valued singular integral. We also use another characterization of the Triehel-Lizorkin space which makes our approach more clear.     

Dissertation; Betreuung; FH-Professor; Lernfreiheit

§ 27 Abs. 4 der Satzung der Universit?t X- Satzungsteil Studienrecht (Satzung) r?umt zwar das Recht ein, eine Betreuerin/einen Betreuer ihrer Dissertation auszuw?hlen; dieses Recht ist jedoch auf die Auswahl auf die "zur Verfügung stehenden" Betreuerinnen/Betreuer eingeschr?nkt und besteht auch in Ansehung dieses Personenkreises nur "nach Ma?gabe der M?glichkeiten".     

概率论在积分中的应用

用概率论的思想方法,能够解决一些积分中的问题,并能体现思想方法的简捷性和独特性,本文在积分不等式的证明和积分计算中引进了概率方法,取得了较好的效果。     

Catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 in NO＋CO reaction

Using SnxTi1-xO2 as carriers, CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 were examined using a microreactor-gas chromatography (GC) NO CO reaction system and the methods of BET (Brun- auer-Emmett-Teller), TG-DTA (themogravimetric and differential thermal analysis), X-ray diffraction (XRD) and H2-temperature programmed reduction (TPR). The results showed that NO conversions of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 were 47.2% and 43.6% respectively, which increased to 95.3% and 90.9% at 6 wt% CuO loading. However, further increase in CuO loading caused a decrease in the catalytic activity. The nitrogen adsorption-desorption isotherm and pore-size distribution curve of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 represented type IV of the BDDT (Brunauer, Deming, Deming and Teller) system and a typical mesoporous sample. There were two CuO diffraction peaks (2θ 35.5° and 38.7°), and the diffraction peak areas increased with increasing CuO loading. TPR analysis also detected three peaks (α, β and γ) from the CuO-loaded catalysts, suggesting that the α peak was the reduction of the highly dispersed copper oxide, the β peak was the reduction of the isolated copper oxide, and the γ peak was the reduction of crystal phase copper oxide. In addition, a fourth peak (δ) of the catalysts meant that the SnxTi1-xO2 mixed oxides could be reductive.     

The Electrochemical Performance of Ml0.7Mm0.3Ni3.7Co0.7Mn0.4Al0.2 Nanocrystalline Hydrogen Storage Alloy as Metal Hydride Electrode

Ml0.7Mm0.3Ni3.7Co0.7Mn0.4Al0.2 nanocrystalline hydrogen storage materials are prepared by melt-spinning(MS).X-ray diffraction is used for the measurement of the nanocrystalline size.Compared to the electrode of polycrystalline alloys,the property of activation MH9metal hydride)electrode of the alloys with nanometer scale became worse and the inital discharge capacity decreased.It may be ascribed to the decrease of the total amount of rare earth metals and the increase of oxygen on the surface from the analysis of components of the alloys.After heat-treatment,the electrochemical performance of MH electrode of as-spun alloys could be improved,which could be attributed to the alleviation of the lattice strain.