Prediction of shelled shrimp weight by machine vision

The weight of shelled shrimp is an important parameter for grading process. The weight prediction of shelled shrimp by contour area is not accurate enough because of the ignorance of the shrimp thickness. In this paper, a multivariate prediction model containing area, perimeter, length, and width was established. A new calibration algorithm for extracting length of shelled shrimp was proposed, which contains binary image thinning, branch recognition and elimination, and length reconstruction, while its width was calculated during the process of length extracting. The model was further validated with another set of images from 30 shelled shrimps. For a comparison purpose, artificial neural network (ANN) was used for the shrimp weight predication. The ANN model resulted in a better prediction accuracy (with the average relative error at 2.67%), but took a tenfold increase in calculation time compared with the weight-area-perimeter (WAP) model (with the average relative error at 3.02%). We thus conclude that the WAP model is a better method for the prediction of the weight of shelled red shrimp.     

木质素磺酸盐外加剂对水泥砂浆性能的影响

针对水泥砂浆抗压强度低及抗渗性能差的问题,采用造纸废液主要成分--木质素磺酸钙为主要原料制备木质素系砂浆外加剂GCL1-M.水泥砂浆物理力学性能和微观结构测试结果表明,添加GCL1-M的砂浆减水率达到了30%,与未掺外加剂的砂浆相比,掺0.30%GCL1-M的硬化砂浆的28天抗压强度提高了20%,渗透压力提高了230%.氮吸附测试和电子扫描显微观测等结果表明,GCL1-M可减慢水泥的水化反应放热速度,降低砂浆的孔径,提高砂浆的抗渗性能.吸附性能及环境扫描电镜等测试结果表明,GCL1-M在水泥颗粒表面可形成网状结构吸附,同时可增加颗粒间的静电斥力位能,从而增强了对水泥砂浆的分散和保水作用,有利于提高砂浆的抗渗性能和抗压强度.     

非正式行为、社会交换与非正式组织博弈分析

组织内非正式行为的密集化是非正式组织形成的基础,论文通过对员工之间非正式行为的社会交换特点分析,探讨了非正式行为的社会交换的理性本质。以此为基础,最后通过博弈分析得出:非正式组织是参与者之间进行成本收益选择而形成的一个纳什均衡解。     

Tundra vegetation of three cirque basins in the northern San Juan Mountains, Colorado

The vegetation of three alpine cirque basins in the northern San Juan Mountains of southwestern Colorado was inventoried and analyzed for the degree of specificity shown by vascular plant communities for certain types of habitats identified as representative of the basins. A total of 197 vascular plant species representing 31 families was inventoried. Growth forms of all species were noted and a growth form spectrum for all of the communities was derived. The caespitose monocot and erect dicot growth forms are the most important growth forms among the community dominants. The most common growth form among all species is the rosette dicot.           

Alpine vascular flora of the Ruby Range, West Elk Mountains, Colorado

The Ruby Range is a northern extension of the West Elk Mountains of west central Colorado. Composed primarily of sedimentary rocks, the range is heavily faulted and intruded by many dikes and sills. Eight study areas, selected as representative of the major topographic features of the range, were analyzed floristically. A vascular flora of 220 species in 111 genera and 35 families is reported. The phytogeographic distribution of the flora is primarily alpine and western North American. The flora of the Ruby Range shows a 74% similarity to the flora of the San Juan Mountains to the southwest.     

CsPbBrI2 perovskites with low energy loss for high-performance indoor and outdoor photovoltaics

Over the years,the efficiency of inorganic perovskite solar cells (PSCs) has increased at an unprecedented pace.However,energy loss in the device has limited a ...     

以煤渣为填料的生物接触氧化法处理污水

研究以煤渣做填料的生物接触氧化法处理高浓度BOD污水的原理与技术;同时介绍其细菌的分离及培养、挂膜技术及运行工艺过程等.本法与其他比较,有占地面积小,经济高效的优越性.     

Precise measurement of single molecule and single cell based on nanopores/nanochannels'charge transfer

Diseases often come from a cell or even a molecule misperforms its function.Obtaining fluctuation of nucleic acids,proteins,gly-cans and other biomolecules is h...