石虎子河小流域降雨年内分配特征研究

结合昌图县石虎子河小流域2018—2021年的降雨数据，统计分析降雨年内分配不均匀系数、集中期和集中度等指标，进一步探究降雨年内分配特征。研究表明：石虎子河小流域降雨以小雨、中雨为主，分布均匀，丰、枯水年降雨分布特征基本一致，月内降雨分配不均匀而旬降雨量明显波动；年内降水集中度0.79～0.82,不均匀系数超过0.8,降雨集中期为每年7月上旬；侵蚀性降雨多发生于6～8月，总体分配不均匀。     

一种特高压带电作业报警器的设计

论文设计一款基于单片机控制的便携式特高压带电作业报警器,该报警器拥有多个可调节的挡位,可以用于多种电压等级(500kV, 750kV, 1000kV)的近电报警。该报警装置采用别针式胸牌的佩戴方式,方便佩戴于衣服任何部位,同时正面印有国家电网公司logo,美观实用。当工作人员佩戴报警器靠近小于安全距离的高压带电体时,报警器迅速响应进行报警,大大提高了作业人员的安全性。     

Direct Conversion of Glucose to 5-Hydroxymethylfurfural over Zirconium Phosphate Catalyst in a Biphasic System

Efficient and selective production of 5-hydroxymethylfurfural(HMF) from glucose was achieved in the presence of zirconium phosphate(ZrPO) catalyst in a biphasic system.With the use of this catalyst,a high HMF yield of 56.8% was obtained from glucose in a water-tetrahydrofuran(THF) biphasic system.Characterization results showed that such catalyst had weak to strong acid sites and contained both Lewis and Br?nsted acid sites.The results of comparative experiments over some other solid acid catalysts demonstrated that the Lewis acid sites on the ZrPO catalyst played a crucial role in the isomerization of glucose to fructose and the Br?nsted ones were active in the dehydration of generated fructose to HMF.Moreover,less levulinic acid(LA) and formic acid(FA)(0.5%) were detected in the reaction solution,indicating that this ZrPO catalyst exhibited high selectivity towards the formation of HMF.Furthermore,the ZrPO catalyst was very stable and could maintain its activity after being used for six times.     

基于SOM网络的差分隐私保护研究

差分隐私模型具有强大的隐私保护能力,但是也存在数据效用低等问题。为提高数据可用性并保护数据隐私,提出一种基于SOM网络的差分隐私算法(SOMDP)。首先利用SOM网络模型对数据进行聚类操作;其次,对每个划分好的聚类添加满足差分隐私的拉普拉斯噪声;最后,理论分析算法的可行性,并在真实数据集上评估SOMDP算法性能、算法的数据可用性和隐私性能。实验结果表明,SOMDP在达到差分隐私要求的前提下,可较大程度地提高差分隐私数据发布的效用。