利用Mathematica求解正轴圆锥投影的标准纬度

针对不同投影条件下的正轴圆锥投影标准纬度求解过程中遇到的数值迭代问题，借助 Mathematica 中的 FindRoot 函数，对涉及超越方程的标准纬度进行计算，得到了相应的数值解。 结果表明，利用 Mathematica 对不同正圆锥投影的标准纬度进行计算，求解过程简单、计算效率高且精度满足要求。     

Characterisation and in vitro cytotoxicity of toxic and degradation compounds in bamboo shoots (Dendrocalamus Sinicus) during traditional fermentation

Fermentation has been historically applied to reduce bamboo shoot (BS) toxicity. However, the underlying degradation pathway of the toxic compounds remains unknown. In this work, the cytotoxicity of BS against the BRL-3A cells was evaluated, and the changes in chemical constituents were determined to reveal the influence of fermentation on BS. The in vitro toxic evaluation revealed fermentation time was crucial in decreasing the toxicity. The main compounds in fresh and fermented were qualitatively and quantitatively determined and were further targeted isolated and identified. A mathematical model to describe the change rate as a function of fermentation time was formulated. Dynamic profiling revealed that taxiphyllin 1 , p-hydroxybenzaldehyde 2 and methyl-p-hydroxybenzoate 3 decreased and transformed into intermediate compounds (p-hydroxybenzoic acid 4 and p-hydroxybenzyl alcohol 5 ), finally converting into p-hydroxytoluene 6 during fermentation. The results provided basis on the chemical components for practical fermentation and the quality control of BS products.     

Region-based image segmentation evaluation via perceptual pooling strategies

Image segmentation is an essential step for many computer vision tasks. Evaluating the quality of image segmentations becomes indispensable for choosing an appropriate output of the image segmentation algorithms. To quantitatively evaluate the segmentation quality, various evaluation measures have been proposed to produce a quality map, and a spatial pooling algorithm is followed to combine the quality map into a single quality score. In this paper, we propose two pooling strategies instead of using the conventional spatial average operation. By assigning perceptual meaningful weights to the quality maps, we obtain evaluation measures that are correlated with the human perception of segmentation quality. Specifically, a quality-based and a visual importance-based pooling strategies are designed and tested on some popular evaluation measures, respectively. To the best of our knowledge, this is the first work that applies perceptual pooling strategies for segmentation evaluation. Extensive experiments are conducted on a subjective evaluation benchmark and the Berkeley Segmentation Dataset (BSDS500). The results indicate that the proposed strategies can improve the performance of existing evaluation measures and produce a more perceptually meaningful judgment on the segmentation quality.     

豆腐果甙对小鼠脑谷氨酸脱羧酶和γ-氨基丁酸转氨酶活性的影响

豆腐果甙(Helicid,简称Hel)系中国科学院昆明植物研究所从山龙眼科萝卜树(Heliciaerratica Hook)的果实中提取的一种成分。其化学名为4’-甲酰基苯基-β-D-吡喃阿洛糖甙(4’-formyl-pheny-β-allopyranoside)。Hel有镇静、催眠和一定的抗惊厥作用,亦可使氨基硫脲(TSC)降低的小鼠脑中γ-氨基丁酸(GABA)水平恢复正常。为此,我们用放射性酶测     

淀粉对硫化矿物和脉石矿物的选择性抑制作用及机理研究进展

随着我国对矿山环保力度的不断加强,绿色选矿药剂的研发显得尤为重要。淀粉以来源广、价格便宜、绿色、可再生和易降解等优势,常被用作黄铁矿、方铅矿、辉钼矿等硫化矿与角闪石、滑石、蛇纹石等硅酸盐矿物的抑制剂。本文介绍了淀粉的结构与性质,阐述了淀粉对不同硫化矿物及易浮脉石矿物的抑制作用及机理,以期学者们对淀粉展开深入研究,实现淀粉在选矿领域的广泛应用。      

基于人工神经网络冷轧带肋钢筋轧制工艺的优化设计

用人工神经网络的计算机辅助技术模拟冷轧带肋钢筋生产工艺的产品性能与工艺参数之间的非线性非显式多目标多变量的映射关系,从而找出其最佳的工艺方案和产品性能,获得满意的产品质量。     

电网企业建筑节电方法及其潜力分析

对电网企业建筑电耗现状进行调研。详细分析电网企业建筑的主要类型及能耗分项计量情况,对在建筑电耗中占比最大的照明设备、空调系统建立节电潜力评估模型,从节能设备和管理手段2个方面有针对性地提出节电改造建议,并以某大型供电局办公大楼、某通信大楼和某220kV变电站等3个建筑为例进行深入分析,展示节电改造效果,最后对南方电网整体建筑节电潜力进行了概算。     

北洺河铁矿生产勘探网度的探讨

通过对生产勘探目的、任务及重要性的分析，介绍了确定生产勘探网度常用的类比、验证、统计3种方法，并选择合适北Ming河铁矿的类比法，结合具体情况及其它原则，初步确定了该矿的生产勘探网度，并对以后应用中应注意的问题提出看法。     

基于时间序列数据的交互式主题河流可视化

主题河流是一种常用的展示时间序列数据的可视化形式,能够有效展示多个主题的整体趋势,但由于下层河流的波动会干扰上层河流,因此用户在观察单个河流时容易产生歧义。而现有的可视化技术无法有效解决这个问题。针对上述传统主题河流存在的问题,提出如下改进方法:采用离散系数评价河流波动程度,将波动小的河流布局在下层,减少对上层河流的影响;提出歧义点概念,为用户提供波动强度和贡献度作为筛选参数,用户根据需求在交互接口中设置筛选参数,系统筛选出可能造成歧义的点在图中动态地进行标识;设计歧义点标识,标识内容包括:使用正三角或倒三角表示该点的峰谷信息;三角的颜色表示贡献度最高的主题信息;交互式主题河流重排序(用户根据歧义点信息,可通过拖拽对河流进行重新排序)。试验数据采用知乎网站的20个主题在2015年全年的活跃度信息,试验结果表明交互式主题河流能有效消除传统主题河流在展示河流趋势时产生的歧义,为用户提供更灵活、个性化的可视化展示。     

STL模型切片轮廓数据的生成算法研究

对基于STL模型的切片处理技术进行了深入分析,并在吸收现有算法优点的基础上,提出了分组排序、对边求交的分层算法。该算法先根据三角面片中顶点在分层方向的最大坐标值和最小坐标值对各面片进行排序并形成分层关系矩阵,然后对每层的三角面片采用对边依次追踪求交的方法生成切片轮廓数据。实际应用表明,该算法具有高效、稳定和可靠等优点。