低温等离子体降解偏二甲肼废水研究

该文研究了悬浮电极介质阻挡放电装置(FE-DBD)产生的低温等离子体对偏二甲肼废水的降 解效果,并对处理条件进行优化。首先,对比了低温等离子体装置、氙灯和紫外灯降解偏二甲肼废水的效果;然后,考察了低温等离子体装置的放电间隙、初始溶液 pH、工作时间和氢氧化钠加投量对偏 二甲肼降解的影响;最后,探究了低温等离子体对偏二甲肼废水 pH 值的影响。实验结果表明,不加入其他试剂的情况下,低温等离子体装置降解偏二甲肼效果好于氙灯及紫外灯;装置放电间隙从 4 mm缩短至 2 mm,偏二甲肼降解率增加 47.2%。随着等离子体处理时间的增加,偏二甲肼的含量降低,处理 20 min 即可降解 82.1% 偏二甲肼。同时,低温等离子体处理会引起偏二甲肼废水 pH 值下降,处理10 min 后废水 pH 从 10 下降至 6.9。废水初始 pH 在 2～10 时,偏二甲肼降解率随废水 pH 值的升高而增大 ：与 pH＝2 相比,初始 pH＝10 时偏二甲肼降解率增加 65.9%。低温等离子体处理 10 min 后,往废水中加入氢氧化钠溶液至终浓度为 1 mg/mL,再继续处理 10 min,可将偏二甲肼降解率提高至 95%。     

pH电极和传感器的进展

水溶液化学中用于非水溶液工作最有用的一个概念是溶液的pH。Sorensen首先作pH定量为水溶液中氢离子浓度的负对数;后来热力学活度概念的发展,又改浓度为活度。理论上只要有H~+离子或OH~-离子参与任何半反应都能用来测量pH,为了实验的实用性和方便,乃使用与氢离子活度非常接近的标准不同溶液中测量电极的电势差为根据,这种电极除氢电极以外有不少种类pH传感器。玻璃电极是后来应用最普通的传感器。     

好多元分辨-交替最小二乘法研究姜黄素的性质及降解过程

采用多元分辨-交替最小二乘法(MCR-ALS)和紫外可见分光光度法研究了姜黄素在不同pH条件下的吸收光谱变化,及其在酸性、中性、碱性条件下的降解过程。光谱数据分辨结果显示了姜黄素在不同pH条件下以及降解过程的所有纯组分光谱和浓度分布曲线,并推测了姜黄素随pH值改变的结构,解析了姜黄素降解过程的动力学曲线。     

pH-ISFET滞后特性及其补偿技术的研究

<正> 本文通过大量实验,对在不同pH值的水溶液中和当水溶液的氢离子活度发生变化时,Si_3N_4膜pH-ISFET的敏感膜与溶液界面电势差的响应过程进行了深入的研究。实验结果表明,Si_3N_4膜pH-ISFET存在着严重的滞后效应,所谓滞后效应是指当溶液的pH值发生变     

用C语言解决溶液体系pH值的计算

确定溶液pH值是化学反应中比较重要的环节，而手工计算溶液的pH值是一个非常烦琐的过程，且极易出错。本文详细介绍如何利用计算机编写C语言程序来解决此类问题，求算时只需要按揭示输入溶液的分析浓度及各级电离常数，程序将自动算出溶液的氢离子浓度和pH值，速度快且精确度高。     

（洛阳市质量技术监督检验测试中心，河南 洛阳 471003）

在pH值中和过程中,由于溶液的酸碱度对产品的质量以及环境有着很大的影响,pH值控制最为重要,因为pH 值对溶液的物理,化学性质都有影响,对其进行控制有很大的意义,因此必须对pH值进行控制。在pH值中和过程的离散化模型的基础上,分析了pH值中和过程的非线性特点,结合迭代学习控制理论,给出P型的具有学习能力的迭代学习智能控制方法,可实现在时间区间上的完全跟踪任务。仿真结果表明,当迭代次数趋于无穷时,P型迭代学习控制方法可以实现对期望值的完全跟踪,验证了该方法的有效性。     

测定甲醇与异丙醇的汽液平衡数据及精馏的研究

甲醇和异丙醇是重要的化工原料和溶剂,作为溶剂使用会产生大量甲醇和异丙醇混合液,本文研究甲醇-异丙醇的分离问题;测定甲醇-异丙醇的汽液平衡数据,采用最小方差法关联汽液平衡数据,并确定相对挥发度方程式;以甲醇-水为标准体系,由精馏结果标定精馏塔的等板高度;在相同条件下,研究不同塔高对甲醇-异丙醇精馏分离的影响,确定塔效率.本文为进一步放大实验提供依据.     

四氨基钴酞菁(CoTAPc)在金电极上成膜过程的研究

采用循环伏安法和石英晶体微天平(QCM)技术对四氨基钴酞菁(CoTAPc)在金电极上的聚合成膜过程进行了研究,考察了扫描速度、溶剂、支持电解质及单体浓度对其成膜过程的影响,同时初步探讨了聚合膜分别在非水溶液和水溶液中的氧化还原行为及稳定性,其中借助EQCM重点讨论了在这些过程中溶液中离子在膜中传输的机理.     

基于支持向量回归的钴铝层状双金属氢氧化物的氟离子吸附容量的预测（英文）

水中氟离子浓度超标带来的水污染是令人关注的热点问题。本工作运用遗传算法-支持向量回归筛选影响钴铝层状双金属氢氧化物(Co-Al LDHs)氟离子吸附容量的主要特征变量,结果表明复合材料的钴元素的摩尔比(Co%)、吸附剂的剂量(M)、溶液的pH值(pH)、溶液的氟离子浓度(C)是主要特征变量。利用上述特征变量构建支持向量回归模型,留一法交叉验证的均方根误差和平均相对误差分别为0.501和19.5%,实验值和预报值的相关系数为0.943。设计样本基于支持向量回归模型(SVR)预报的氟离子吸附容量与验证实验结果相一致。因此,本工作所建立的支持向量回归模型有望在氟离子吸附容量预报工作中得到进一步的应用。     

无创血糖检测中不同葡萄糖浓度的介电- 频率响应特性研究

无创血糖检测技术具有无痛感、不易感染和可连续监测等优点,是血糖检测技术发展的重要 方向。为了研究在不同频率下、不同葡萄糖浓度对介电特性的影响,该文首先以不同葡萄糖浓度的 水溶液为研究对象,探索了 500 kHz～5 MHz 频率范围内不同葡萄糖浓度水溶液的介电-频率特性。 研究表明,葡萄糖水溶液在 500 kHz～5 MHz 的响应特性与高频下的响应特性不同。在该频段下,当 葡萄糖浓度不变时,水溶液的复介电常数的实部和虚部随着频率的增大而减小;当频率不变时,水 溶液的复介电常数的实部和虚部随着葡萄糖浓度的增大而减小。其次,该文还通过对复介电常数测量 值进行二阶 Debye 模型拟合,并对 Debye 模型中的参数进行了二次多项式拟合。拟合的决定系数均 高于 0.93,最终得出了葡萄糖浓度为 0～16% 水溶液的复介电常数在不同葡萄糖浓度和频率下的相关 函数,量化了葡萄糖水溶液的复介电常数与葡萄糖浓度及频率的关系。最后,通过建立包含皮肤、血 液、肌肉的无创血糖检测模型,并采用基于时域有限差分法对模型进行仿真分析。结果表明,接收电 极 2 与 3 之间的电压差值随着葡萄糖浓度的增加而线性增大,为基于 500 kHz～5 MHz 频率范围内的 无创血糖检测提供了一定的理论基础。     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).