1．5阶微分阳极溶出伏安法测定补锌口服液中微量元素锌

章研究了1．5阶微分阳极溶出伏安法测定维微康口服液中微量锌。以kCl—en(pH=11．6)为支持电解质,玻炭电极为工作电极,在-1．80V(Vs,SCE)电位下富集,可得一灵敏的微分阳极溶出峰。峰电位功Ep=-1．30V,峰电流Ip与Zn(Ⅱ)的浓度在0．005～0．050μg/ml范围内呈线性关系,最低检出限为0．001μg/ml。该法应用于补锌口服液中锌含量的测定,简便、快速、准确。     

温度对微分电位溶出法测定铜锌铅镉影响的研究

研究了温度对微分电位溶出法测定铜、锌、铅、镉的影响,15℃-50℃之间Pb、Cd、Zn溶出峰高稳定,铜的溶出峰高随温度升高而增高。解决了Cu在较弱酸性条件下被基线饱和区掩盖不易测定的问题。     

温度对微分电位溶出法测定铜锌铅镉影响的研究

研究了温度对微分电位溶出法测定铜、锌、铅、镉的影响,15℃-50℃之间Pb、Cd、Zn溶出峰高稳定,铜的溶出峰高随温度升高而增高。解决了Cu在较弱酸性条件下被基线饱和区掩盖不易测定的问题。     

8-羟基喹啉修饰玻碳电极微分脉冲溶出伏安法测定痕量铅

本文报道了一种用化学修饰电极测定水中铅离子的新方法.实验过程中,各种实验参数如电解质种类及酸度、修饰剂用量、富集电位和时间、扫描速度得到一定的优化.在pH=4.0的HAc-NaAc缓冲溶液中,铅离子与8-羟基喹啉生成螯合物富集在电极表面,然后在-1.0V被还原成零价的铅,在向阳极电位扫描的过程中,还原的铅被氧化而从电极表面溶出,出现阳极溶出峰,根据溶出峰电流可测定痕量铅离子.实验测得铅的线性范围为1×10-8mol/L至5×10-5mol/L,检测限为1×10-11mol/L.在5×10-7mol/LPb(Ⅱ)试液中,连续测定3次的标准偏差为6.3%.     

混凝土中氯离子含量的测定

用电位滴定法测定混凝土中氯离子含量,研究了其影响因素,并将电位滴定法与铬酸钾法进行了比较.结果表明:溶出液振荡时间越长及水固比越大,越有利于氯离子的溶出;淀粉可有效分散氯化银胶体溶液,增强溶液的稳定性;pH值、电极等均对测定有影响;电位滴定法不受色度、浊度影响,其准确度、精密度均高于铬酸钾法.     

丁二酮肟修饰玻碳电极差分脉冲溶出伏安法测定痕量铅

提出了一种用丁二酮肟修饰玻碳电极,以差分脉冲溶出伏安法测定水中痕量铅离子的方法.在实验过程中,对各种实验参数如电解质种类及酸度、丁二酮肟用量、富集电位和时间、扫描速度等进行一定的优化.在pH=5.6的HAc-NaAc缓冲溶液中,铅离子与丁二酮肟生成螯合物富集在电极表面,然后在-0.8V被还原成零价的铅,在向阳极电位扫描的过程中,还原的铅被氧化而从电极表面溶出,于-0.60V形成阳极溶出峰,且峰电流与待测物浓度成正比,据此溶出峰电流可定量测定痕量铅离子.实验测得铅的线性范围为1×10-7 mol/L至5×10-5 mol/L,检测限为1×10-9 mol/L.在同一含量的体系中平行测定6次1×10-7 mol/L Pb2+的溶液,其标准偏差为2.9%.用丁二酮肟修饰玻碳电极测定水样中的铅离子,取得满意结果.     

几种血铅测定方法的比较

血铅浓度测定方法较多,但在方法学上对其比较的较少,本文通过对目前常用的三种测定方法进行方法学比较,得出微分电位溶出(DPSA)法是目前血铅测定最好的方法,它具有标本用量少、操作简便、使用安全、精密度高、准确度好等优点。     

单扫描示波极谱法测定皮蛋中微量的铅

研究了在盐酸-碘化钾-酒石酸钠-抗坏血酸-十二烷基磺酸钠底液中,用单扫描示波极谱法获得铅与碘化钾络合物吸附波,用于微量铅的测量.在此底液中峰电位在-544mV(vs.SCE),峰电流与铅离子的浓度在0.01-2.9 ug.ml-1范围内呈良好的线性关系,检出限为0.01ug.ml-1,线性回归方程为:Iy=44.49Cx 4.53(其中Cx为铅离子的浓度),r=0.9998,用标准加入法测得样品回收率在98.4%-103.9%之间,样品的相对标准偏差小于5%.用此方法测定皮蛋中微量铅,操作简便,快速,准确度高,结果令人满意.     

极大量氯化物中微量碘的测定

微量碘的分析方法主要有:比色法,溶出法,中子活化法等。比色法虽然灵敏度较高,但对稍微有色或混浊溶液中测定碘产生困难;普通极谱法由于分辨力较差,极大量氯化物中微量碘不适于溶出法测定,而且重金属元素如Cu、Cd、Pb严重干扰,甚至有时不得不控制电位电解分离,这是一个费时很长的过程。使用脉冲极谱仪阴极溶出伏安法测定微量碘,简便快速,但由于要使用较贵重的仪器而不便推广。以碘离子选择性电极法测定微量碘,具有方法简便快速,仪器也较简单的优点,但当极大量氯化物存在时给测定微量碘带来了困难。本文研究了极大量氯化物存在下微量碘的测定方法,提出以阴离子交换柱富集I~-而排除Cl~-,然后再以KNO_3或NaNO_3作为洗脱剂,和离子强度调节剂,冲洗交换到柱子上的I~-,最后以碘离子选择性电极法进行测定。     

单扫描示波极谱法测定皮蛋中微量铅的方法研究

在0.01g/mL碘化钾,0.016g/mL酒石酸钾钠,0.001g/mL抗坏血酸,0.24mol/L盐酸底液中,采用单扫描示波极谱法获得铅和碘络合物吸附波,用于皮蛋中微量铅的测量。文中讨论了碘化钾、酒石酸钾钠、抗坏血酸、盐酸的加入量及静止时间对反应的影响从而确定了适宜的实验条件。实验表明,铅在此底液中峰电位在-520mV,峰电流与铅离子的浓度在0.2～1.0μg/mL范围内呈良好的线性关系,线性回归方程为:Iy=2 492.2Cx+332.1,相关系数r2=0.999 4。回收率为98.4%～103.9%。此方法测定皮蛋中微量铅,仪器简单,操作快速、简便,准确度高,测定结果令人满意。     

Dynamische Probleml?sekompetenz

This article is about the importance and validity of dynamic problem solving (DPS) in predicting technical problem solving performances. In addition to DPS, fluid intelligence and technical knowledge were included in the study. Assessing DPS and fluid intelligence simultaneously also allowed for testing the empirical distinction between both constructs. Results are based on data of a sample of car mechatronics (n?=?129) and electronics technicians (n?=?88) and showed that DPS and fluid intelligence were empirically separable. In the first sample (electronics technicians) DPS explained technical problem solving performance best, although fluid intelligence showed incremental validity too. In the second sample (car mechatronics) fluid intelligence was weakly related to the criterion whereas DPS was not at all. When technical knowledge was added to the prediction, both DPS and fluid intelligence did not predict technical problem solving performance. However, in the sample of the electronics technicians fluid intelligence indirectly affected the criterion through technical knowledge. A discussion of the somewhat contradictory results, the different results patterns in the two samples and a theoretical explanation of the results are provided.     

城市居民消费结构变动的因子分析

在居民消费结构研究中,应用最广泛的是恩格尔系数和线性支出系统,但在进行消费结构变动分析时,因指标较多且各指标的变化趋势不尽相同,很难看出居民消费在某一方面的变动趋势.多元统计分析中的因子分析法正是解决这一问题的有力工具,文中利用因子分析法和DPS数据处理系统,对泰安城市居民消费结构的变动情况进行了分析.     

串(并)联谐振DC-DC开关变流器分析和设计

本文通过对各种串并联谐振DC-DC开并变流器和输出整流器的比较,阐述了在分布式电源系统中,在DC-DC原边变流器中采用串并联谐振LLC谐振变流器和输出端采用全波整流器电路,在高输入电压的情况下,循环能量减小,输入电压范围可以拓宽,并且效率可以提高,损耗可明显减小。本文对串并联谐振谐振变换器的工作原理和控制方法进行了细致的分析,建立了谐振变换器的各个工作模式的条件,并给出了计算机仿真实验分析数据。     

Higher education access and participation: political dependency and student choice

The two-fold purpose of this article is: (a) to review Australian trends concerning retention rates to the final year of high school, transition rates to higher education, and the phenomena underlying these rates including the impact of political intervention; and (b) to outline a pilot study conducted to identify and describe the dynamics of the decision process stages (DPS) through which high school students proceed in choosing to undertake university study and conjoint levels of (un)certainty. Factors underlying a current perception of crisis within Australian higher education are identified. Complex patterns of predictive associations among six general categories of predictors and the DPS, which operate differently during the various years of high school, are also examined. The relationship between the two is established with some suggestions for policy.     

四轮移动机器人运动控制系统设计

介绍了一种可在未知环境下自主工作的移动机器人运动控制系统设计。该控制系统采用TI公司TMS320LF2407DSP作为处理器,利用步进电机作为驱动装置。文章讨论了系统硬件设计、软件控制策略、速度控制器设计及其DSP实现。     

Higher education choice in Australia: Processes and impediments

This article outlines and interprets the results of a pilot study designed to evaluate the impact of various social and personal factors on the decision process stages (DPS) through which years 7–12 high school students proceed in choosing to undertake study in the university sector of higher education in Australia. The article also examines the associated effects of background factors influencing participation in higher education generally. Complex patterns of predictive associations between the factors and seven DPS which appear to operate differently during the various years of high school are outlined. The differences are described in terms of six general categories of predictors. Comparative studies evaluating the effects of background factors on participation in higher education are examined to broaden the contextual base of the research findings and to identify the contribution of theories of social change, with particular emphasis on the meritocratic thesis. The interpretation of the research findings is assisted by relating them to Erik Erikson's developmental framework concerned with the growth of the conscious self or personal identity.     

串/并联级联混合型有源电力滤波器APF控制技术和电路拓扑结构研究

并联有源电力滤波器是一种用于动态抑制谐波和补偿无功的新型电力电子装置,近年来,有源电力滤波器的理论研究和应用均取得了较大的成功。对其主电路（VSI）参数的设计也进行了许多探讨,APF的作用是用电压型或电流型逆变器产生一个“注入”电网的谐波电流,以抵消其它装置有网侧产生和谐波电流,进而净化电网侧的电压和电流波形。通过分析有源电力滤波器的交流侧滤波电路对电流补偿性能的影响,在满足一定效率的条件下,对有源电力滤波器电路进行了仿真分析研究。     

Continuous frequency and phase spectrograms： a study of their 2D and 3D capabilities and application to musical signal analysis

A new lighting and enlargement on phase spectrogram （PS） and frequency spectrogram （FS） is presented in this paper. These representations result from the coupling of power spectrogram and short time Fourier transform （STFT）. The main contribution is the construction of the 3D phase spectrogram （3DPS） and the 3D frequency spectrogram （3DFS）. These new tools allow such specific test signals as small slope linear chirp, phase jump case of musical signal analysis is reported. The main objective is to and small frequency jump to be analyzed. An application detect small frequency and phase variations in order to characterize each type of sound attack without losing the amplitude information given by power spectrogram     

Intercultural education in Detroit, 1943–1954

In the World War II era, many United States educators recognised that the claims of racial superiority underlying German anti-Semitism and Japanese imperialism challenged the fundamental democratic idea of human equality that is the bedrock of US political ideals. At the same time, these educators realised the importance of national social cohesion for political unity and strength. Their response to this challenge was to develop school programmes that emphasised the principles of equality of opportunity and inalienable human rights, that promoted respect for diverse races and cultures, that warned against the dangers of race-based totalitarianism and that taught all students to fulfil their responsibilities as US citizens. These programmes, generally referred to as ‘intercultural education’, enjoyed their greatest success from the late 1930s to the early 1950s.

In practice, most intercultural education programmes, as implemented in schools, did not live up to the ideals established by intercultural education’s founders. Instead, most programmes focused on the cultural contributions of diverse groups and on values such as tolerance and appreciation for differences. Yet one large and influential public school district, the Detroit Public Schools (DPS) district, did fulfil many of the expectations for the programmes. DPS administrators and teachers pushed intercultural education in more daring directions, directly tackling deeper structural issues such as power, privilege, discrimination, equality and race to help students from different racial and cultural backgrounds respect one another and to help groups that were traditionally discriminated against achieve their full rights as citizens. Intercultural education in Detroit simultaneously taught students to value racial and cultural diversity and to cherish and follow civic values – not an easy task. Although intercultural education was a short-lived movement, ending in the 1950s in Detroit and around the country, we demonstrate that many initiatives of intercultural education formed the basis for accomplishments several decades later, during what is known as the multicultural education movement. Intercultural education also had a legacy through Norman Drachler, a leader of the intercultural programmes in the 1940s: years later, as General Superintendent of the DPS in the late 1960s, Drachler would lead the effort to dramatically change US history textbooks to be inclusive of diverse people and groups.     

2009年全国高考理综（全国卷Ⅰ）化学试题能力考核因素的研究及启示

运用DPS因素分析原理,侧重对2009年全国高考理综（全国卷Ⅰ）化学试题能力结构的分析和研究,为化学教师的日常教学以及高考复习培养学生的能力提供理论研究依据。