Three dimensional fluorescence excitation-emission on matrix spectrum of dissolved organic substance in marine microalgaes growth process

The three-dimensional fluorescence spectrum was used to detect the changes in dissolved organic substances from the cultured Skeletonema costatum, Alexandrium tamarense, Alexandrium mimutum, Scrippsiella trochodea, Prorocentrum donghaiense and Prorocentrum micans. The result indicates that all of the microalgaes can produce FDOM in the growth courses. Diatom such as Skeletonema costatum can produce humic-like FDOM. However dinoflagellate can produce protein-like FDOM at exponential growth phase. When the algae grows into decadency phase, the intensity of humic-like and protein-like fluorescence augments rapidly, which may be due to a mass of FDOM realeased by the old or dead cell fragmentation and the degradation of bacteria by using non-FDOM. The fluorescent intensity of Alexandrium tamarense, Alexandrium mimutum, Prorocentrum donghaiense and Prorocentrum micans can reduce at anaphase of decadency phase because of the degradation of bacteria and light. The same genus of algae can produce similar FDOM, for example: Alexandrium tamarense, and Alexandrium mimutum, Prorocentrum donghaiense and Prorocentrum micans, but the positions of the fluorescence peaks are different.

A three-dimensional coupled physical-biological model study in the spring of 1993 in the Bohai Sea of China

A three-dimensional (3-D) coupled physical and biological model was used to investigate the physical processes and their influence on the ecosystem dynamics of the Bohai Sea of China. The physical processes include M-2 tide, time - varying wind forcing and river discharge. Wind records from I to 31 May in 1993 were selected to force the model. The biological model is based on a simple, nitrate and phosphate limited, lower trophic food web system. The simulated results showed that variation of residual currents forced by M, tide, river discharge and time-varying wind had great impact on the distribution of phytoplankton biomass in the Laizhou Bay. High phytoplankton biomass appeared in the upwelling region. Numerical experiments based on the barotropic model and baroclinic model with no wind and water discharge were also conducted. Differences in the results by the baroclinic model and the barotropic model were significant: more patches appeared in the baroclinic model comparing with the barotropic model. And in the baroclinic model, the subsurface maximum phytoplankton biomass patches formed in the stratified water.

Synthesis and. crystal structure of N '-(4-fluorobenzylidene)-2-(1H-1,2,4-triazole-1-yl) acetohydrazide

N'-(4-fluorobenzylidene)-2-(1H-1 2,4-triazole-1-yl) acetohydrazide was synthesized by the reaction of 4-fluorobenzaldehyde with 2-(1H-1 2,4-triazole-1-yl) acetohydrazide. The structure was confirmed via elemental analysis, MS, H-1 NMR, IR, and X-ray diffraction. It crystallized in a monoclinic system with space group P2 (1) a = 0.4905 (1) nm, b = 0.8160 (2) nm, c = 1.4105 (3) nm, beta = 93.33 (3)degrees, Z = 2, V = 0.5636 (2) nm(3), D-c = 1.457 Mg/m(3), mu = 0.112 mm(-1), F(000) = 256, and final R-1 = 0.0685. Several intermolecular hydrogen-bond interactions existed in the crystal structure, facilitating the stabilization of the compound.

捕食风险对不同饥饿状态下艾虎取食行为的影响

在室内条件下,将大鵟作为艾虎的天敌动物,通过双通道选择实验确定6只成体艾虎在3个捕食风险水平和4种饥饿状态条件下的取食行为,探讨艾虎在取食过程中对饥饿风险与捕食风险的权衡策略.研究结果表明:在无捕食风险存在时,艾虎被剥夺食物0 d和1 d后对食物量不同的两个斑块中的取食量和利用频次均无明显不同(P＞0.05),但对高食物量斑块的利用时间均明显高于低食物量斑块的(P＜0.05),而艾虎被剥夺食物2 d和3 d后对高食物量斑块中的取食量和利用时间均明显高于低食物量斑块中的(P＜0.05),但在利用频次上均无明显差异(P＞0.05).在面临低风险时,艾虎在4种饥饿状态下均只利用无天敌动物存在的低食物量斑块,而基本不利用有天敌动物存在的高食物量斑块.在面临高风险时,艾虎不得不利用有天敌动物存在的食物斑块,被剥夺食物0 d时艾虎对无风险、无食物量斑块的利用时间基本相同于对高风险、有食物量斑块的利用时间(P＞0.05),而被剥夺食物1 d、2 d和3 d后艾虎对高风险、有食物量斑块的利用时间明显高于无风险、无食物量斑块的(P＜0.05).在相同风险条件下,随着饥饿程度增加,艾虎在斑块中的取食量均明显增加(P＜0.05),而对斑块的利用时间和利用频次明显降低(P＜0.05).在相同的饥饿状态下,不同风险水平时,艾虎在斑块中的取食量无明显的差异(P＞0.05),但在低风险和高风险时对斑块的利用时间和频次均明显低于无风险时的(P＜0.05).以上结果说明艾虎能够根据食物摄取率和自身的能量需求在捕食风险和饥饿风险之间做出权衡,当饥饿风险小于捕食风险时,艾虎趋于躲避捕食风险,当饥饿风险大于捕食风险时,艾虎趋于面对捕食风险,所采用的取食策略是减少活动时间和能量消耗,最大程度地提高单位时间内获得的能量.

高效液相色谱-质谱分离鉴定荧光试剂标记的脂肪酸

以2-(2-(10-蒽基)-萘[2,3-d]咪唑)-乙基-对甲苯磺酸酯(ANITS)作为柱前衍生化试剂,在Eclipse XDB-C8色谱柱上,梯度洗脱实现了20种游离脂肪酸(FFA)衍生物的完全基线分离.90℃下在DMF溶剂中以K2CO3作催化剂,选取衍生试剂摩尔数为脂肪酸的7倍,衍生反应40 min可获得稳定的荧光产物.激发和发射波长分别为250 nm和512 nm.采用大气压化学电离源(APCI)正离子模式,实现了油菜蜂花粉中游离脂肪酸的质谱鉴定.所有脂肪酸的线性相关系数均大于0.9999, 检出限为24.76～98.79 fmol.

模拟高原低氧对新生大鼠肾上腺皮质功能发育的影响

本文探讨新生大鼠肾上腺皮质对高原低氧的应答及模拟高原低氧对其功能发育的影响。结果表明, 当不同日龄大鼠暴露于5 km 及7 km 海拔24 h, 7 d、14 d 龄大鼠肾上腺皮质无明显应答反应。21 d 及28 d 龄大鼠肾上腺皮质酮水平随海拔增高而增加, 血浆皮质酮表现为抑制作用。当1 d 龄新生大鼠在5 km 海拔高度发育3 d 和7 d,其肾上腺皮质功能无异于正常发育大鼠; 但发育14 d、21 d 及28 d, 其血液及肾上腺中皮质酮含量均明显低于对照组, 肾上腺皮质功能发育严重受抑。

Analysis of saturated free fatty acids from pollen by HPLC with fluorescence detection

A sensitive method for the determination of free fatty acids using 2-(2-(anthracen-10-yl)-1H-naphtho[2,3-dimidazol-1-yl) ethyl-p-toluenesuIfonate (ANITS) as tagging reagent with fluorescence detection has been developed. ANITS could easily and quickly label fatty acids in the presence of the K2CO3 catalyst at 90 degrees C for 40 min in N,N-dimethylformamide solvent. From the extracts of rape bee pollen samples, 20 free fatty acids were sensitively determined. Fatty acid derivatives were separated on a reversed-phase Eclipse XDB-C8 column by HPLC in conjunction with gradient elution. The corresponding derivatives were identified by post-column APCI/MS in positive-ion detection mode. ANITS-fatty acid derivatives gave an intense molecular ion peak at mlz [M+H](+); with MS/MS analysis, the collision-induced dissociation spectra of m/z [M+H](+) produced the specific fragment ions at mlz [M-345](+) and mlz 345.0 (here, m/z 345 is the core structural moiety of the ANITS molecule). The fluorescence excitation and emission wavelengths of the derivatives were lambda(ex) = 250 nm and lambda(em) = 512 nm, respectively. Linear correlation coefficients for all fatty acid derivatives are > 0.9999. Detection limits, at a signal-to-noise ratio of 3 : 1, are 24.76-98.79 fmol for the labeled fatty acids.

一种移动机器人在三维动态环境下的路径规划方法

提出一种基于遗传算法的三维动态环境下的路径规划方法,通过对机器人的运动行为进行编码,将各种约束条件融入到遗传算法当中,规划出可实际应用的避障路径,仿真研究表明该方法是简单有效的。

基于立体视觉的移动机器人楼梯识别

本文提出了一种结构化环境下,基于立体视觉的机器人楼梯识别算法,并将算法该应到自主移动机器人上。该算法首先利用二维图像分析的方法搜索楼梯的疑似区域;进而利用立体视觉对各个疑似区域进行精确三维重建,结合三维信息重构楼梯平面,排除虚假疑似楼梯区域;最后判定机器人和楼梯的相对位姿关系,引导机器人爬楼梯。最终我们将该算法应用到了自主移动机器人上,通过在各种光照条件下的实验,进一步验证了该算法的准确性和快速性。

轮式移动机器人与地形交互运动仿真研究

分析了轮式移动机器人(WMR)在不平坦的三维地形上运动的运动学模型.利用速度投影法,得到了WMR运动模型的一种新形式.基于虚拟现实技术,利用VC++OpenGL实现了WMR虚拟漫游系统.该系统具有较强的交互性和实时性,为星球探测机器人的虚拟导航、遥操作等提供了验证平台.

链式可重构机器人单模块结构设计与运动实验

提出了一种新型模块化链式移动机器人机构,它具有可重构、自动变形的特点。单个标准模块主要由中间通孔式连接手臂、履带驱动链传动装置、模块偏转锥齿轮传动装置、模块俯仰链传动装置、连接柄等组成。模块间由偏转关节、连接柄、连接臂和仰俯关节进行连接组合。为提高单个模块的机动性和实现运动自主功能,对标准模块进行了适当改进,单模块机器人采用了履带、轮、臂、腿组合的移动机构,具有三维空间的运动能力。最后对单模块机器人样机在垂直壁障碍、平地支腿、平地转弯、斜坡、楼梯等情况下的运动能力进行了实验,为进一步实现多模块机器人的自重构和环境应用打下了基础。

基于神经网络的三维物体姿态测定

利用单幅图象中物体的三条边与模型中的三条对应边,可求出三维物体姿态,但解不唯一,通过将这些可能姿态所产生的图象与实际图象匹配,可求出唯一正确姿态.二维图象特征对应问题是个NP完全问题,存在组合爆炸的困难,为此,我们把特征对应问题看作一个组合优化问题,利用Hopfield网络成功解决这一组合优化问题.该算法通用性强,而且适合于并行实现。文中给出了在Ⅵ-COM图象处理系统上对人造图象和实际图象进行的实验结果。

三维物体识别及姿态测定的推理系统

本文介绍了三维物体识别及姿态测定的一种新技术，从物体空间域模型出发，通过约束推理及几何推理，在物体三维信息部分给定的条件下，推断预测图象模型，并通过实测的图象数据反馈，推断出隐含在图象中未给定的三维信息，最终实现三维物体识别及姿态测定。整个系统在ＶＩＣＯＭ机上用Ｃ语言完成。

利用BP神经网络实现三维物体姿态的测定

本文利用BP(Back-Propagation)人工神经网络对三维物体的姿态测定进行了研究。姿态测定一直缺少通用而实际的方法,人工神经网络由于具有强大的自组织、自适应学习能力,迅速的并行信息处理能力,可望解决这个问题。但现有BP算法存在训练慢和易陷入局部最小两个问题.本文提出的级联形式网络结构,使BP网络的训练速度大为提高,陷入局部最小的可能性大为降低。利用这种级联结构对飞机模型姿态测定,取得了较好的实验结果。

景物的三维信息获取及其运动分析

采用模糊熵函数对图象象素分类作出整体最优分类评价,实现了区域分割.利用矩及其函数做为各区域的特征表达,构成以区域为基元的符号特征集并描述图象内容。根据立体图象对间的几何关系,解出各区域(基元)的相对三维坐标。与象索匹配相比较,它可以获得较高精度的三维信息和可描述的景物信息.通过获取不同时空的各区域(基元)三维信息,确定了它们的空间运动状态。联系这些状态,构造出景物中物体间的空间关系和近似模型,实现了对景物的3-D识别和描述。