腰果油改性硼酚醛树脂的制备及性能

本文以腰果油作为一种置换酚与酚(双酚A、苯酚)硼酸、多聚甲醛及六次甲基四胺在草酸的催化作用下,经两步反应制得了一种改性的硼酚醛树脂,并对其耐水解性和耐热稳定性进行了研究,结果表明此种树脂具有优良的耐水和耐热稳定性。     

米曲霉利用农业废弃物产木聚糖酶的条件优化

主要研究了米曲霉利用农业废弃物产木聚糖酶的情况.对实验室保藏菌株米曲霉M-9生长所必需的碳源、氮源、培养温度和培养基初始pH等条件进行了优化.实验表明,此菌株最适碳源是粒度小于0.08 mm的玉米芯(质量分数为4.0%),最佳复合氮源是质量分数为1.2%的酵母提取物加质量分数为0.8%的大豆蛋白胨,最适初始pH值为7.5,最适产酶温度为30℃,最佳转速为200 r/m in,添加表面活性剂吐温60对菌株产酶有促进作用.在最适培养条件下,培养5 d,米曲霉沪酿M-9木聚糖酶的产量高达795.93 U/mL,是优化前的2.2倍.     

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.     

悬索结构计算方法探讨

文章概述了悬索结构非线性计算理论的两节点直线单元、两节点曲线单元、三节点抛物元以及五节点悬链元模型,并且提出了三种具有一定精度的分别适合于不同条件的索结构计算的ANSYS实现方法,最后对以上诸方法进行了总结与评价.     

一类二阶具多偏差变元微分方程的周期解

主要讨论了一类二阶具多偏差变元的泛函微分方程周期解的存在性,利用重合度理论和关于周期函数的最佳不等式,得到了文中的若干结论．     

上海市生活垃圾分选模式研究

采用孔径为120mm，40mm和mm的三种手动筛，对生活垃圾筛分，并对筛分后生活垃圾分类，通过对其质量和含量的测定，得出如下结论：粒径大于120mm范围内的生活垃圾中，有资源化潜力的组分为塑料、有机物、纸类、包装物及玻璃；粒径为40～120mm范围内生活垃圾中，有资源化潜力的组分为有机物、塑料、玻璃、金属和包装物；粒径为8～40mm范围内的生活垃圾，只要将玻璃分离开来，可以直接生物处理；而粒径小于8mm的生活垃圾，可以直接生物处理．根据这个实验结果，为上海市生活垃圾制定了一条机械分选流程．     

Creep behavior and effect factors of a TiAl–Nb alloy at high temperature

The effect of solution treatment on the microstructure and creep properties of forged TiAl-Nb alloys was investigated.The results showed that the microstructure of forged alloy mainly consisted of γ/α₂ lamellar colonies and fine equiaxed recrystallized γ/α₂ grains.During the solution treatment the microstructure of the alloy transformed into a fully lamellar structure due to the lamellar colonies growth by consuming equiaxed grains.Compared with the forged alloy the creep l...     

中药废水处理方法研究

中药工业废水成分复杂,水质不稳定,处理难度较大,未见较为成熟的工艺技术。近年来,广大科研工作者对中药工业废水的处理技术进行了广泛的研究。对各类污水处理技术在中药工业废水处理中的应用研究进行了介绍,并对中药工业废水处理的应用技术的推广应用提出了建议。     

Genuine electronic structure and superconducting gap structure in(Ba0.6K0.4)Fe2As2 superconductor

The electronic structure and superconducting gap structure are prerequisites to establish microscopic theories in understanding the superconductivity mechanism ...     

网约车平台两阶段定价研究

平台在不同的发展阶段所面临的效应并不相同，必须采取针对性的定价策略。现有文献对两阶段定价策略和临界情况的研究比较有限。本研究依据网约车平台发展周期，研究了“扩张+盈利”两阶段的模式背后的定价机理。研究表明：扩张阶段只存在交叉网络外部性的情况下，网约车平台对双边用户的最优定价与交叉网络外部性和盈利阶段所面临的组内网络外部性正相关。盈利阶段同时存在交叉网络外部性和组内网络外部性的情况下，最优定价与交叉网络外部性正相关，与组内网络外部性负相关。本研究还探讨了网约车平台快速积累用户实现“烧钱”向“盈利”模式转变的影响因素，并给出相应的管理启示。