基于模糊神经网络的池塘溶解氧预测模型

在分析了池塘溶解氧影响因素的基础上,利用模糊神经网络良好的非线性逼近能力建立了池塘溶解氧的模糊神经网络预测模型。神经网络模型如采用常规的BP或其它梯度算法,常导致训练时间较长且易陷入局部极小点,本实验采用快速的粒子群优化算法对模糊神经网络进行训练,收敛速度明显加快。实验结果表明采用该方法预报溶解氧的预测精度较常规BP递推算法的预测精度明显提高,所采用的模型能对溶解氧进行可靠的预测,该方法为研制开发智能水质检测仪以及工厂化养殖工作奠定了基础,对实际生产具有一定的指导意义。     

A model of the spring migration into the North Sea by Calanus finmarchicus overwintering off the Scottish continental shelf

A particle tracking model was used to investigate the annual spring invasion of the North Sea by Calanus finmarchicus copepodites which overwinter in deep water off the Scottish continental shelf. Flow fields generated by a hydrodynamic model (HDM) were used to simulate the advection of zero drag particles representing the copepods. Particles were released simultaneously from a regular lattice of start positions at a given depth ( D ₁), and ascended at a fixed rate ( dD/dt ) until they reached a final depth ( D ₂) in the surface layers. The proportion of particles reaching target areas in the northern North Sea was relatively insensitive to a moderate degree of variation (±20%) around chosen default values of the vertical migration parameters ( D ₁, D ₂ and dD/dt ), derived from field data. The inclusion of horizontal diffusion velocities and diel vertical migration in surface layers did not significantly affect the results. Sensitivity to wind direction was investigated by applying flow fields from HDM runs with different wind forcing scenarios. For the default vertical migration parameters, only north-westerly winds resulted in particles entering the North Sea from release locations north of the Iceland–Scotland Ridge, where dense aggregations of overwintering copepods were encountered during field surveys. The particle tracking model predicted that the major routes for the spring Calanus invasion into the North Sea were the East of Shetland Atlantic Inflow and the Norwegian Trench Atlantic Inflow, which agreed with seasonal trends observed in Continuous Plankton Recorder data. Overall, despite its relative simplicity, particle tracking was confirmed as a robust tool to explore the causal mechanisms behind the annual invasion of the North Sea by C. finmarchicus emerging from diapause in the deep waters off the Scottish continental shelf.     

沙地柏土壤特性与生物量的关系

对毛乌素沙地固定沙地不同地形（沙丘的顶部、迎风面、底部）中的沙地柏生物量进行比较,分析了土壤养分状况、土壤粒径与生物量关系。结果表明：迎风面的氮、有机质含量比较高,能够促进生物量的提高;天然沙地柏（土层深度〈50 cm）土壤颗粒组成均是以50-100μm的颗粒为主,生物量与土壤颗粒之间可相互影响。     

混合汁中蔗糠含量对沉降和过滤影响的探讨

该文用实验和动态生产试验的方法探讨了蔗糠含量对沉降速度、过滤速度和干滤泥转光度的影响；指出，过量或过少蔗糠含量对这三者会产生急剧干扰；认为，亚法澄清的过滤尚需适量蔗糠作助滤剂等。     

北方长寿命霓虹灯制作工艺的探讨

经过多年实践跟踪,摸索出适应北方长寿命霓虹灯制做的关键工艺方法,从而提高了北方霓虹灯的使用寿命。     

矿粒粒径对深海采矿扬矿泵磨损特性的影响

为研究矿粒粒径对深海采矿扬矿泵过流部件磨损特性的影响,采用DPM模型模拟泵内固液两相流动,并以基于流体动力学的Oka磨损模型仿真颗粒对过流部件的磨损,分析扬矿泵在不同矿粒粒径下的磨损规律.研究结果表明:随着矿粒粒径的增大,首级叶轮及次级叶轮的前后盖板磨损量分布逐渐均匀,前盖板磨损量的集中区域从出口压力面向叶轮中部及进口吸力面转移,后盖板磨损量集中分布区域从进口吸力面一侧向出口压力面一侧转移,叶片进口和出口的磨损面积均逐渐增大;首级空间导叶及次级空间导叶的叶片背面进口磨损面积逐渐增大,在轮毂出口处磨损区域向外逐渐偏移,且该位置磨损面积逐渐减小;当矿粒粒径从1.0 mm增大到5.0 mm时,首级叶轮和次级叶轮的前盖板最大磨损量分别上升132.9%和104.2%,首级叶轮和次级叶轮的叶片最大磨损量分别上升172.3%和142.5%,首级叶轮和次级叶轮的后盖板最大磨损量分别上升251.4%和102.3%,首级导叶和次级导叶的最大磨损量分别下降87.08%和74.26%.     

The biotechnology of crop legumes

Summary The absence of variety-independent gene transfer methods for major agronomic species has, until now, limited the usefulness of recombinant DNA techniques to crop improvement programs. Until recently, only Solanaceous crops could be used to study fundamental and applied problems in plant sciences. During the past five years rapid advances in cell biology, in combination with the development of novel gene transfer methodology allowed utilization of the tools of plant molecular biology in conventional breeding programs. Cereal and leguminous species were considered to be recalcitrant to genetic manipulation. As a result of the development of direct DNA transfer methodology into organized tissue, we are now in a position to introduce any foreign gene into almost all of the major cereals and legumes. This can be achieved efficiently, often in a variety-independent fashion. The object of this review is to provide a comprehensive account of the state of the art in gene transfer for the cultivated leguminous crops. Important oilseed and feed species primarily in industrialized countries, as well as minor but equally important species for sustaining growth populations in developing countries will be examined. Advantages of the various gene transfer methods that were shown to be useful for specific crops, as well as limitations and problems associated with each crop and gene transfer method will be discussed. Data from field trials of transgenic legumes, where available, will be presented.     

Parallel Optical Method in Laser Speckle Velocimetry and Particle Image Velocimetry

A method of parallel optical processing of double exposure specklegram or particle image using hololens array is presented.It can greatly decrease the processing time because the mechanical moving time of the X Y translation stage is decreased by tens of times.     

Cotton Image Segmentation Algorithm Based on Fusion Method of Markov Random Field and Quantum Particle Swarm Cluster

[Objective] The aim of this study was to improve the cotton image segmentation accuracy in a picking robot image processing system. [Method] An image segmentation algorithm based on a fusion method of Markov random field and quantum particle swarm optimization clustering was proposed. The process of the proposed algorithm is as follows: first, transform the RGB (red, green, blue) images into grayscale; second, use it to segment these images; finally, the threshold of the connected area is set on the basis of the segmented image to obtain the target area. Then, the cotton front image and the cotton side image are selected from the images collected from different angles. The segmentation experiment was carried out by using this algorithm, and compared with the Otsu algorithm, the fuzzy C-means algorithm, the quantum particle swarm image segmentation algorithm and the Markov random field image segmentation algorithm. [Result] The results showed that the segmentation accuracy and peak signal to noise ratio of the proposed algorithm were 98.94% and 77.48 dB. When compared with the Otsu algorithm, fuzzy C-means algorithm, quantum particle swarm optimization algorithm and Markov random field algorithm, the average segmentation accuracy and peak signal to noise ratio of the proposed algorithm increased by 2.47%–4.56%, and 9.81–13.11 dB, respectively. [Conclusion] The proposed algorithm had higher segmentation accuracy and higher peak signal to noise ratio than the other algorithms tested.     

不同生长年限铁皮石斛提取物的抗氧化活性及其水溶液性质的研究

比较了2年生和4年生铁皮石斛提取物对DPPH自由基和超氧阴离子的清除能力,并研究了这两组铁皮石斛提取物水溶液的粒度分布特点。结果表明,4年生铁皮石斛提取物对DPPH自由基和超氧阴离子的清除能力高于2年生铁皮石斛提取物,说明生长年限对铁皮石斛提取物的抗氧化性影响较大。1 mg/m L的2年生铁皮石斛提取物水溶液粒度分布主要集中在30~80 nm,而4年生铁皮石斛提取物水溶液在同样浓度下的粒度分布主要集中在110~125 nm。