新型植物杀菌剂--苯并噻二唑类植物抗病诱导剂

植物抗病诱导剂是近年来发现的一种新型植物杀菌剂，苯并噻二唑类(BTH)就是其中重要的一类。对近年来BTH研究情况作一简要综述。     

A high propylene productivity over B2O3/SiO2@honeycomb cordierite catalyst for oxidative dehydrogenation of propane

Boron-based metal-free catalysts for oxidative dehydrogenation of propane (ODHP) have drawn great attention in both academia and industry due to their impressive activity and olefin selectivity. Herein, the SiO₂ and B₂O₃ sequentially coated honeycomb cordierite catalyst is designed by a two-step wash-coat method with different B₂O₃ loadings (0.1%-10%) and calcination temperatures (600, 700, 800 ℃). SiO₂ obtained by TEOS hydrolysis acts as a media layer to bridge the cordierite substrate and boron oxide via abundant Si-OH groups. The welldeveloped straight channels of honeycomb cordierite make it possible to carry out the reactor under high gas hourly space velocity (GHSV) and the thin wash-coated B₂O₃ layer can effectively facilitate the pore diffusion on the catalyst. The prepared B₂O₃/SiO₂@HC monolithic catalyst exhibits good catalytic performance at low boron oxide loading and achieves excellent propylene selectivity (86.0%), olefin selectivity (97.6%, propylene and ethylene) and negligible CO₂ (0.1%) at 16.9% propane conversion under high GHSV of 345,600 ml·(g B₂O₃)^-1·h^-1, leading to a high propylene space time yield of 15.7 g C₃H₆·(g B₂O₃)^-1·h^-1 by suppressing the overoxidation. The obtained results strongly indicate that the boron-based monolithic catalyst can be properly fabricated to warrant the high activity and high throughput with its high gas/surface ratio and straight channels.     

A high propylene productivity over B2O3/SiO2@honeycomb cordierite catalyst for oxidative dehydrogenation of propane

Boron-based metal-free catalysts for oxidative dehydrogenation of propane (ODHP) have drawn great attention in both academia and industry due to their impressive activity and olefin selectivity. Herein, the SiO₂ and B₂O₃ sequentially coated honeycomb cordierite catalyst is designed by a two-step wash-coat method with different B₂O₃ loadings (0.1%–10%) and calcination temperatures (600, 700, 800 °C). SiO₂ obtained by TEOS hydrolysis acts as a media layer to bridge the cordierite substrate and boron oxide via abundant SiOH groups. The well-developed straight channels of honeycomb cordierite make it possible to carry out the reactor under high gas hourly space velocity (GHSV) and the thin wash-coated B₂O₃ layer can effectively facilitate the pore diffusion on the catalyst. The prepared B₂O₃/SiO₂@HC monolithic catalyst exhibits good catalytic performance at low boron oxide loading and achieves excellent propylene selectivity (86.0%), olefin selectivity (97.6%, propylene and ethylene) and negligible CO₂ (0.1%) at 16.9% propane conversion under high GHSV of 345,600 ml·(g B₂O₃)⁻¹·h⁻¹, leading to a high propylene space time yield of 15.7 g C₃H₆·(g B₂O₃)⁻¹·h⁻¹ by suppressing the overoxidation. The obtained results strongly indicate that the boron-based monolithic catalyst can be properly fabricated to warrant the high activity and high throughput with its high gas/surface ratio and straight channels.     

乙烯装置急冷系统能量回收工艺特点分析

乙烯装置急冷系统接收来自炉区的高温裂解气，为降低乙烯装置能耗，必须尽可能回收裂解气中的热量。文中针对KBR乙烯流程，介绍了乙烯装置急冷系统能量逐步回收的过程及其工艺特点。     

基于样本缩减的支持向量机在流分类中的应用

网络流量分类对提高网络服务质量有着非常重要的作用.基于机器学习的网络流量分类中,海量的样本为训练带来了效率瓶颈.论文介绍了SVM算法原理,建立基于改进类别质心的样本缩减策略,并进行实验验证.结果表明,利用缩减样本的SVM训练时间仅为在原样本下训练时间的2％,且分类精度基本不变,证明了样本缩减策略的可行性和有效性.     

大采高综采工作面瓦斯与煤自燃综合治理技术

针对张集煤矿1215（3）高产高效综采工作面高瓦斯、易自燃开采过程中的安全问题,本文介绍了大采高综采工作面采空区顶板高位抽采技术,优化顶板走向钻孔位置,结合顺层钻孔和上隅角埋管等抽采瓦斯措施综合治理瓦斯,同时采取均压通风、加快工作面推进速度、采空区灌浆、注氮等技术措施防治煤自燃,保证了回采期间回风流瓦斯浓度平均小于0.5%,CO浓度20PPm以下,实现了工作面的正常安全生产。研究成果为淮南矿区一次采全高高产高效工作面的瓦斯、防火治理提供了借鉴经验。     

基于IOWA算子的区间组合预测方法

针对预测值与实际值都以区间数形式给出的组合预测问题,引进诱导有序加权平均(IOWA)算子,提出了以区间中心位置误差平方和与区间长度误差平方和的凸组合为准则的区间组合预测模型,给出了确定Ⅰ-OWA算子区间组合预测模型权系数的数学规划方法,实例分析表明,该模型能有效提高区间组合预测精度.     

企业选择IT外包服务商的模糊综合评价研究

IT外包是企业利用市场信息资源的一种有效途径,如何有效选择外包服务商是外包企业在进行外包决策的过程中所面临的一个重要问题.在相关研究的基础上,提出了一种选择IT外包服务商的模糊综合评价模型,将其运用于具体案例,结果显示该模型是有效、可行的.     

储能用锂电池模组主动式热管理系统性能研究

热管理对于保证电池模组的使用性能(包括安全性和寿命)具有重要意义.针对储能用方形锂离子电池模块,通过热流体模型仿真,研究了主动式风冷和液冷热管理系统性能.模块原串行式风冷方案被优化改进为串(并)行混合式风冷方案,提高了电池组温度场一致性,但对于降低最高温度作用有限,并发现液冷系统热管控性能明显优于风冷.还比较研究了风冷和液冷方案的能耗情况以及循环充放电过程中变流量工况对能耗的影响,发现空冷系统能耗约为液冷系统的6.2倍;变流量策略可以满足有效热管理的要求,而且降低了风冷系统24.3％的能耗和液冷系统19.7％的能耗.     

高速钢中贝氏体的二次硬化特征

研究了6-5-4-2高速钢中贝氏体和马氏体回火后的力学性能和组织结构。结果表明,贝氏体比马氏体具有更高的二次硬化效应以及抗回火稳定性和冲击韧性。透射电镜观察发现,马氏体在二次硬化峰温度范围回火时,有Fe_3C析出,而贝氏体铁素体和奥氏体中只析出弥散的MC和M_2C合金碳化物。这表明在贝氏体长大过程中存在合金元素的扩散。