纸基质固体表面化学发光法测定微量铜的研究

建立了Luminol—H_2O_2—Cu(Ⅱ)纸基质固体表面化学发光体系.该体系用于测定Cu(Ⅱ)的线性范围为10～1000ng,检测限为0.50ng绝对量。对10ngCu(Ⅱ)进行11次平行测定,其RSD=7.9％.考察了30多种共存离子的干扰情况,拟定了单矿物样中铜的测定方案.     

我国有色金属出口额的组合预测模型

有色金属产品是我国出口商品结构中的一个重要组成部分,在竞争激烈的国际市场上,中国有色金属产品的出口前景如何,需要我们用科学的方法加以预测。本文以一个典型产品(锑品)和一个典型市场(美国市场)为例,分别用二元线性回归模型和时间序列分析,对今后八年我国有色金属产品出口额进行了预测,并在这两种预测方法的基础上,推出了一种预测误差更小的组合预测模型。本文还对组合预测模型中权重的确定和预测误差的无偏性进行了证明。     

Assessment on alien herbicide-resistant gene flow among crucifers by sexual compatibility

Cross-pollination and high cross-compatibility are frequently found in many cruciferous plants, which implies that there might be potential risk of alien gene flow among crucifers. In this work, the alien glyphosate-resistant gene flow between GM （Genetically modified） rapeseed variety Q3 （Brassica napus） and 6 varieties from 5 cruciferous species was assessed by sexual compatibility through aniline blue fluorescence observation, manual cross, mentor pollination with the mixture pollen and DNA identification. The results indicated that the compatibility indices of two B. napus varieties, B. juncea vat. multiceps Tsen et Lee and Chinese cabbage （B. chinensis） （as female） with Q3 （as male） were 16.15, 12.77, 2.345 and 0.85, respectively. FI plants were examined by PCR and all of these samples were confirmed as positive. Crossing between Orychophragmus violaceus, Descurainia sophia （as female） and Q3 （as male） expressed high cross-incompatibility. Fluorescence microscope observation indicated that growing of pollen tube terminated at the upper 1/3 part of the style of O. violaceus and on the stigma surface of D. sophia. The mentor plants were further analyzed by PCR and all were shown to be negative. Under the neighboring growth and natural pollination conditions, the rates of gene flow to two B. napus varieties were 2.3278% and 2.1487%, respectively, B. juncea var. multiceps Tsen et Lee and Chinese cabbage were 1.0157% and 0.9236%, respectively. No gene flow was observed in O. violaceus and D. sophia. Frequency of gene flow was highly correlated with sexual compatibility. Due to possible alien gene flow among crucifers, special consideration and care should be taken to grow GM rapeseed.     

基于置乱和混沌加密的数字图像水印技术研究

为了进一步增加水印系统的安全性,对经过置乱变换的二值数字图像水印用时空混沌技术进行加密,使攻击者无法解读嵌入的水印.     

Determination of cell volume during equilibrium freezing process

A new type electronic particle counter (EPC, Multisizer^TM 3, Beckman Coulter Inc., USA) was used to determine the volumes of human red blood cells (RBCs) in NaCl solutions of different osmolalities. The thermodynamics model describing cell response during freezing process was used to simulate the volume change of RBC in 0.9% NaCl solution during equilibrium freezing process. It was assumed that the effect of temperature on cell volume can be neglected compared to that of osmolality, then by using the phase diagram for the binary system sodium chloride/water, the osmolalities of the NaCl solution under different sub-zero temperatures can be obtained (converted from mass concentration), then the calculated values of RBC volumes can be validated by the experiments.     

A novel theoretical model for mass transfer of hollow fiber hemodialyzers

A novel theoretical model for mass transfer of hollow fiber bundles in hemodialyzers is presented. In the model, a hemodialyzer is considered as a porous zone which is composed of two non-interpenetrating porous flow zones.Firstly, the dialysate side (shell side) is thought as a porous medium zone. Then by solidifying the dialysate flow zone and the occupied zone by hollow fiber membrane, the rest zone of bemodialyzer (i.e. blood side or lumen side) is considered as a porous medium zone too. Finally, the interface of the two flow zones is the fiber membrane through which mass transfer is performed. The dialysate and blood flows are all described by Navier-Stokes equations with Darcy momentum source terms. Kedem-Katchaisky equations as other source terms are added into Navier-Stokes equations to simulate the permeating flux through the membrane. All equations must be coupled together in the process of computing. The model is validated by the experimental data in literature. The simulative results show that the predicted clearances agree well with the experimental data, and the model in this paper is better than other models for the forecast of clearance.     

基于PCL818HG高速数据采集系统的设计

前端数据采集的速度关系到检测和控制系统的性能．数据采集卡一旦选定,要从硬件上提高系统对数据采集的速度较困难．文中基于ＰＣＬ８１８ＨＧ数据采集卡建立的数据检控系统,提出了运用软件技术提高数据采集速度,进而实现系统对数据的高速采集．结果显示,对机械运动部件动态特性的快速检测具有较高的实用价值,对传感器及其系统的设计也有着较高的参考价值．     

自适应神经网络判决树及其在人脸识别领域的应用

提出了一种神经网络与判决树结合而成的新结构———自适应神经网络判决树（ＡｄａｐｔｉｖｅＮｅｕｒａｌＮｅｔｗｏｒｋｓＤｅｃｉｓｉｏｎＴｒｅｅ,简称ＡＮＮＤＴ）。实验表明,基于ＡＮＮＤＴ的人脸识别方法,能够综合利用多种神经网络模型和特征提取算法,不仅具有较高的识别速度、准确率、容错性和健壮性,而且基本满足开发实用化人脸识别系统的要求。     

选择性高分子离子交换树脂处理含砷废水

合成制备了一种对Ａｓ（Ⅲ）离子高效选择性吸附的螯合离子交换树脂,研究了该螯合树脂从含砷溶液中脱除砷的最佳条件。用该离子交换柱吸附脱砷;柱体１０ｍｍ（φ）×２５５ｍｍ、常温、ｐＨ５．０、流速６００ｍＬ／ｈ,含Ａｓ（Ⅲ）５ｇ／Ｌ的溶液脱砷率高于９９．９９％,脱砷溶液中砷含量完全达标,含Ａｓ（Ⅲ）溶液中共有的其它离子绝大部分不干扰螯合树脂树Ａｓ（Ⅲ）离子的交换吸附,仅Ｈｇ（Ⅱ）离子在该螯合树脂上也表现出     

CaCl2*6H2O-MgCl2*6H2O多温截面的研究

用步冷曲线法研究并绘制了ＣａＣｌ２·６Ｈ２Ｏ－ＭｇＣｌ２·６Ｈ２Ｏ多温截面图,实验显示该截面有两个四相转熔反应,其转熔温度分别为２５．０℃和２２．０℃．结果表明,ＣａＣｌ２·６Ｈ２Ｏ－ＭｇＣｌ２·６Ｈ２Ｏ混合盐可用于低温相变储热．