苯并[α]芘致突变研究的声波／微生物传感技术

提出了一种采用串联式声波/鼠伤寒沙门氏菌(S.typhimurium TA98)传感器对苯并[α]芘(Benzo[α]pyrene)致突变过程进行实时监测的新方法.确定了测试研究的相关实验条件,对苯并[α]芘的微生物学致突变过程进行了研究.频移与1.2～9.6 mg/L浓度范围内的苯并[α]芘有线性关系.     

人工神经网络在预测供体位点的运用研究

阐述人工神经网络(ANN)的基本原理,针对基因供体位点预测的问题,对样本数据进行整理,建立和优化人工神经网络模型.结果表明,采用人工神经网络对供体位点进行预测是切实可行的,并且有比较高的精确度.     

运用人工神经网络预测一代粘虫发生程度的研究

根据历年的积累资料,采用人工神经网络方法,对黑龙江东南农田一代粘虫发生程度进行了预测预报研究。结果表明：该方法性能良好,预测准确,可望成为植物病虫害预测预报一种新的有效辅助手段     

参考作物蒸发蒸腾量的人工神经网络模型研究

根据河套灌区多年气象资料和Penman-Monteith法计算得到的参考作物蒸发蒸腾量(ET0),回归分析了影响ET0的主成分.在此基础上比较了以4因子(平均气温、净辐射、相对湿度、2m处风速)和3因子(平均气温、净辐射、相对湿度)为输入向量,由Penman-Monteith法计算所得ET0为输出向量的BP网络ET0预报模型(BP-ET0).研究表明,BP网络可以用于ET0的预报计算,4因子法和3因子法均简便可行,能满足生产的需要.相比之下,4因子法的精度更高.此研究是对传统ET0计算的补充.     

基于人工神经网络的发电机故障暂态稳定性预测方法研究

提出了一种利用径向基函数神经网络(RBFNN)预测大扰动后发电机转子转角值的方法,来实时判断系统暂态稳定状态,并对相干发电机组的辨识进行了研究。在故障后将相量测量单元(PMU)同步采样的前六个周期的发电机的转子角度和电压等数据作为神经网络的输入,以预测系统未来的状态。该方法还可以实时判断发电机的同步状态。在测试系统上对该方法以不同运行条件进行了评估,实验结果证明所提出的径向基函数神经网络对扰动后的转子转角值具有良好的预测性能,适合于实时应用。     

基于人工神经网络的含硫原油VGO饱和份含量预测研究

利用多种含硫原油的实验分析数据,采用动最自适应学习率的BP人工神经网络理论,建立了含硫原油VGO的平均沸点、密度、分子量、折光率等4个基础物性与其饱和分含量关系的预测模型,通过该人工神经网络模型的训练,获得了较高的训练精度,模型计算值与实验值相比,VGO饱和份含量的平均相对误差为1.59%;用该模型检验未参加训练的6种油样,预测结果的平均相对误差为5.79%,表明此方法拟合精度较高、预测能力较强,可用于含硫原油基础物性的初步预测.     

基于遗传神经网络的旋转机械故障预测方法研究

许多大型旋转机械运行工况恶劣,非平稳、非线性特征明显,以及各种突发性、偶然性因素的影响,给基于振动信号处理的状态预测和状态维护分析带来困难;神经网络以其强大的处理非线性系统的能力在故障预测中得到广泛的应用,但由于其在追求高精度训练目标时易陷入局部极值,且收敛速度慢甚至发散;针对这个问题,提出了采用遗传算法对神经网络连接权值和阈值进行优化,这样不仅发挥了神经网络广泛的映射特性也使遗传算法的全局搜索优势尽显无疑;通过组合这两种算法,在提升网络学习的准确度方面,优点尤其突出,最终提高对旋转机械故障预测和寿命估计的性能,这在某环境模拟试验系统动力风机的轴承磨损故障预测中得到了验证。     

基于贝叶斯正则化BP人工神经网络的煤与瓦斯突出预测的研究

文章介绍了BP人工神经网络和贝叶斯正则化算法的原理,探讨了贝叶斯正则化BP人工神经网络模型的建立,通过改变隐含层神经元个数的实验建立了只含1个隐含层且隐含层仅需1个神经元的煤与瓦斯突出预测模型的最佳网络结构。对该网络采用煤与瓦斯突出的预测指标进行训练、检测的结果表明,该网络预测的煤与瓦斯突出的危险程度与实际情况完全吻合;对该网络输入层输入的煤与瓦斯突出的预测指标、对输出层输出的预测结果的权值进行分析的结果表明,煤层地质构造类型对煤与瓦斯突出的影响为最大。上述研究结果对煤与瓦斯突出的预测预防研究、提高煤与瓦斯突出预测的准确性具有一定的参考价值。     

3-取代4-氧-3H-咪唑并[5,1-d][1,2,3,5]四嗪-8-羧酸衍生物抗肿瘤活性的定量构效关系研究

目的:研究3-取代4-氧-3H-咪唑并[5,1-d][1,2,3,5]四嗪-8-羧酸衍生物分子结构与抗肿瘤活性的关系.方法:采用量子化学和分子力学方法计算分子结构参数,利用Cram-Schmidt正交化法筛选参数,利用偏最小二乘法建立QsAR模型.结果:建立合理的3-取代-4.氧-3H-咪唑并[5,1-d][1,2,3,5]四嗪-8-羧酸衍生物抗肿瘤活性模型.结论:3-取代-4-氧-3H-咪唑并[5,1-d][1,2,3,5]四嗪-8-羧酸衍生物抗肿瘤活性与分子油水分配系数LogP和8位取代基R1上的非氢原子净电荷Q1相关,研究结果可为同类抗肿瘤药物的分子设计提供参考.     

利用混料设计和香农信息熵优化香烟主流烟气萃取溶液的配比

采用混料设计原理进行试验设计,结合香农信息熵作为色谱指纹图谱信息含量的评价指标,对寻找香烟烟气中主要成分萃取溶液的最佳配比进行了系统研究。以甲醇、乙醇和二氯甲烷为主要萃取溶液,通过自动进样将提取液进行气相色谱正交加速飞行时间质谱(GC/oa-TOF-MS)分析,结果表明:(1)二氯甲烷与乙醇的混合溶液提取效率最好,其色谱图信息明显高于以二氯甲烷与甲醇为混合溶液的所得色谱;(2)在二氯甲烷和乙醇的混合溶剂中,随着乙醇浓度增加,各物质出峰顺序基本一致,但其谱峰个数、峰宽及峰高变化明显;(3)当二氯甲烷和乙醇比率为0.8:0.2时,多个谱峰明显高于其他组之相同谱峰,并出现多个其他组没有的特征峰,得到谱峰分离度最好。     

卷烟主流烟气粒相物硅烷衍生化GC-MS数据的解析

应用化学计量学方法对卷烟的主流烟气粒相物中极性非挥发物硅烷衍生化的CC-MS数据进行了解析。首先应用主成分分析法判断各色谱峰中的化学成分数。对于其中含有多种成分的重叠峰,应用多变量曲线分辨-变换最小二乘法(MCR- ALS)进行解析。用最大不相关法选取MCR-ALS的一组初始迭代矢量。最后根据总离子流图对解析得到的色谱峰曲线进行标度化。对选定样品的GC-MS数据进行判别,发现17％的色谱峰是2种或3种成分的重叠峰,经过解析可得到较好的色谱图和质谱图。结果表明了此方法在复杂样品的GC-MS数据解析中的有效性。     

Potentiometric detection of chromium (III) on the carbon fiber electrode modified by n-hexyl calix[4]resorcinarene

This study was carried out to develop the application of modified carbon fiber electrode in environmental detection, by which chromium (III) ion in water could be electrochemically detected. The modified carbon fiber electrode manifested a linear response within the range of 1.9 × 10⁻⁶–4.6 × 10⁻⁴ mol L⁻¹ (R = 0.9939) and the detection limit was 7.9 × 10⁻⁷ mol L⁻¹. The effect factors were studied to reveal the optimal conditions in the detection of chromium (III) in water, such as pH of total ionic strength adjustment buffer, the concentration of calix[4]resorcinarene, sweep cycles, and so on. The modified carbon fiber electrode, the diameter of which was about 7 μm, was characterized by field emission scanning electron microscopy and electrochemical impedance spectroscopy. Also, the proper mechanism was discussed. The identification of chromium (III) was mainly attributed to the cavity of the calix[4]resorcinarene that the chromium (III) ion could enter into the inner of calix[4]resorcinarene because of the particular structure of calix[4]resorcinarene.     

BendyLights: Artistic Control of Direct Illumination by Curving Light Rays

In computer cinematography, artists routinely use non‐physical lighting models to achieve desired appearances. This paper presents BendyLights, a non‐physical lighting model where light travels nonlinearly along splines, allowing artists to control light direction and shadow position at different points in the scene independently. Since the light deformation is smoothly defined at all world‐space positions, the resulting non‐physical lighting effects remain spatially consistent, avoiding the frequent incongruences of many non‐physical models. BendyLights are controlled simply by reshaping splines, using familiar interfaces, and require very few parameters. BendyLight control points can be keyframed to support animated lighting effects. We demonstrate BendyLights both in a realtime rendering system for editing and a production renderer for final rendering, where we show that BendyLights can also be used with global illumination.     

Inverse Procedural Modeling by Automatic Generation of L‐systems

We present an important step towards the solution of the problem of inverse procedural modeling by generating parametric context‐free L‐systems that represent an input 2D model. The L‐system rules efficiently code the regular structures and the parameters represent the properties of the structure transformations. The algorithm takes as input a 2D vector image that is composed of atomic elements, such as curves and poly‐lines. Similar elements are recognized and assigned terminal symbols of an L‐system alphabet. The terminal symbols' position and orientation are pair‐wise compared and the transformations are stored as points in multiple 4D transformation spaces. By careful analysis of the clusters in the transformation spaces, we detect sequences of elements and code them as L‐system rules. The coded elements are then removed from the clusters, the clusters are updated, and then the analysis attempts to code groups of elements in (hierarchies) the same way. The analysis ends with a single group of elements that is coded as an L‐system axiom. We recognize and code branching sequences of linearly translated, scaled, and rotated elements and their hierarchies. The L‐system not only represents the input image, but it can also be used for various editing operations. By changing the L‐system parameters, the image can be randomized, symmetrized, and groups of elements and regular structures can be edited. By changing the terminal and non‐terminal symbols, elements or groups of elements can be replaced.     

Fast Updating of Delaunay Triangulation of Moving Points by Bi‐cell Filtering

Updating a Delaunay triangulation when data points are slightly moved is the bottleneck of computation time in variational methods for mesh generation and remeshing. Utilizing the connectivity coherence between two consecutive Delaunay triangulations for computation speedup is the key to solving this problem. Our contribution is an effective filtering technique that confirms most bi‐cells whose Delaunay connectivities remain unchanged after the points are perturbed. Based on bi‐cell flipping, we present an efficient algorithm for updating two‐dimensional and three‐dimensional Delaunay triangulations of dynamic point sets. Experimental results show that our algorithm outperforms previous methods.     

Optimized Generation of Stereoscopic CGI Films by 3D Image Warping

The generation of a stereoscopic animation film requires doubling the rendering times and hence the cost. In this paper, we address this problem and propose an automatic system for generating a stereo pair from a given image and its depth map. Although several solutions exist in the literature, the high standards of image quality required in the context of a professional animation studio forced us to develop specially crafted algorithms that avoid artefacts caused by occlusions, anti‐aliasing filters, etc. This paper describes all the algorithms involved in our system and provides their GPU implementation. The proposed system has been tested with real‐life working scenarios. Our experiments show that the second view of the stereoscopic pair can be computed with as little as 15% of the effort of the original image while guaranteeing a similar quality.     

Efficient encoding of texture coordinates guided by mesh geometry

In this paper, we investigate the possibilities of efficient encoding of UV coordinates associated with vertices of a triangle mesh. Since most parametrization schemes attempt to achieve at least some level of conformality, we exploit the similarity of the shapes of triangles in the mesh and in the parametrization. We propose two approaches building on this idea: first, applying a recently proposed generalization of the parallelogram predictor, using the inner angles of mesh triangles corresponding to the UV‐space triangles. Second, we propose an encoding method based on discrete Laplace operator, which also allows exploiting the information contained in the mesh geometry to efficiently encode the parametrization. Our experiments show that the proposed approach leads to savings of up to 3 bits per UV vertex, without loss of precision.