中国科学技术大学学报最新文献_第2页

Experimental study on the effect of additives on the heat transfer performance of spray cold plate 添加剂对喷雾冷板传热性能影响的实验研究

Journal of University of Science and Technology of China Pub Date : 2022-01-01 DOI: 10.52396/justc-2021-0152

Ruoxin Liu, R. Zhao, Yong-Le Nian, W. Cheng

{"title":"Experimental study on the effect of additives on the heat transfer performance of spray cold plate","authors":"Ruoxin Liu, R. Zhao, Yong-Le Nian, W. Cheng","doi":"10.52396/justc-2021-0152","DOIUrl":"https://doi.org/10.52396/justc-2021-0152","url":null,"abstract":"The spray cold plate has a compact structure and high-efficiency heat exchange, which can meet the requirements of high heat flux dissipation of multiple heat sources, and is a reliable means to solve the heat dissipation of the next generation of chips. This paper proposes to use surfactants to enhance the heat transfer of the spray cold plate, and conduct a systematic experimental study on the heat transfer performance of the spray cold plate under different types and concentrations of additives. It was found that among the three surfactants, sodium dodecyl sulfate (SDS) can improve the heat transfer performance of the spray cold plate, and at the optimal concentration of 200ppm, the heat transfer coefficient of the spray cold plate was increased significantly by 19.8%. Both the n-octanol-distilled water and Tween 20-distilled water can reduce the heat transfer performance of the cold plate using multi nozzles. In addition, based on the experimental data, the dimensionless heat transfers correlations for the spray cold plate using additives were conducted, and the maximum errors of dimensionless correlations for using additives were 2.1%, 2.8%, and 5.4% respectively. This discovery provides a theoretical analysis and basis for the improvement of spray cold plates.","PeriodicalId":17548,"journal":{"name":"Journal of University of Science and Technology of China","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89120046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Distributed Nash equilibrium seeking design for energy consumption games of HVAC systems over digraphs 有向图上HVAC系统能耗博弈的分布式纳什均衡寻求设计

Journal of University of Science and Technology of China Pub Date : 2022-01-01 DOI: 10.52396/justc-2021-0153

Xinyu Liu, Jin Zhang, H. Ji, Xinghu Wang

引用次数: 0

TiO2-assisted GaN-nanowire-based stable ultraviolet photoelectrochemical detection 二氧化钛辅助氮化镓纳米线稳定紫外光电电化学检测

Journal of University of Science and Technology of China Pub Date : 2022-01-01 DOI: 10.52396/justc-2021-0205

Yang Kang, Xin Liu, Danhao Wang, Shih-Hao Fang, Yuan Luo, Haiding Sun

{"title":"TiO2-assisted GaN-nanowire-based stable ultraviolet photoelectrochemical detection","authors":"Yang Kang, Xin Liu, Danhao Wang, Shih-Hao Fang, Yuan Luo, Haiding Sun","doi":"10.52396/justc-2021-0205","DOIUrl":"https://doi.org/10.52396/justc-2021-0205","url":null,"abstract":"Ultraviolet photodetection plays an important role in optical communication and chemical- and bio- related sensing applications. Gallium nitride (GaN) nanowires-based photoelectrochemical-type photodetectors, which operate particularly in acqueous conditions, have been attracted extensive interest because of their low cost, fast photoresponse, and excellent responsivity. However, GaN nanowires, which have a large surface-to-volume ratio, suffer suffered from instability in photoelectrochemical environments because of photocorrosion. In this study, the structural and photoelectrochemical properties of GaN nanowires with improved photoresponse and chemical stability obtained by coating the nanowire surface with an ultrathin TiO2 protective layer were investigated. The photocurrent density of TiO2-coated GaN nanowires changed minimally over a relatively long operation time of 2000 s under 365-nm illumination. Meanwhile, the attenuation coefficient of the photocurrent density could be reduced to 49%, whereas it is as high as 85% in uncoated GaN nanowires. Furthermore, the photoelectrochemical behavior of the nanowires was investigated through electrochemical impedance spectroscopy measurements. The results shed light on the construction of long-term-stable GaN-nanowire-based photoelectrochemical-type photodetectors.","PeriodicalId":17548,"journal":{"name":"Journal of University of Science and Technology of China","volume":"110 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91043193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Steganalysis of neural networks based on parameter statistical bias 基于参数统计偏差的神经网络隐写分析

Journal of University of Science and Technology of China Pub Date : 2022-01-01 DOI: 10.52396/justc-2021-0197

Yi Yin, Weiming Zhang, Nenghai Yu, Kejiang Chen

{"title":"Steganalysis of neural networks based on parameter statistical bias","authors":"Yi Yin, Weiming Zhang, Nenghai Yu, Kejiang Chen","doi":"10.52396/justc-2021-0197","DOIUrl":"https://doi.org/10.52396/justc-2021-0197","url":null,"abstract":"Many pretrained deep learning models have been released to help engineers and researchers develop deep learning-based systems or conduct research with minimall effort. Previous work has shown that at secret message can be embedded in neural network parameters without compromising the accuracy of the model. Malicious developers can, therefore, hide malware or other baneful information in pretrained models, causing harm to society. Hence, reliable detection of these vicious pretrained models is urgently needed. We analyze existing approaches for hiding messages and find that they will ineluctably cause biases in the parameter statistics. Therefore, we propose steganalysis methods for steganography on neural network parameters that extract statistics from benign and malicious models and build classifiers based on the extracted statistics. To the best of our knowledge, this is the first study on neural network steganalysis. The experimental results reveal that our proposed algorithm can effectively detect a model with an embedded message. Notably, our detection methods are still valid in cases where the payload of the stego model is low.","PeriodicalId":17548,"journal":{"name":"Journal of University of Science and Technology of China","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82526683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Numerical investigation on heat transfer characterization of liquid lithium metal in pipe 液态锂金属在管道中的传热特性数值研究

Journal of University of Science and Technology of China Pub Date : 2022-01-01 DOI: 10.52396/justc-2021-0043

Yongfu Liu, Peng Tan

{"title":"Numerical investigation on heat transfer characterization of liquid lithium metal in pipe","authors":"Yongfu Liu, Peng Tan","doi":"10.52396/justc-2021-0043","DOIUrl":"https://doi.org/10.52396/justc-2021-0043","url":null,"abstract":"Liquid Li metal is a promising nuclear reactor coolant; however, relevant research regarding its heat transfer characteristics remains insufficient. In this study, a steady-state two-dimensional mathematical model is established to describe the heat transfer process of liquid Li in a straight pipe. A numerical analysis is conducted to investigate the effects of inlet velocity, inlet temperature, and wall heat flux on heat transfer in liquid Li. The results indicate the advantage of using liquid Li for improving heat transfer at high inlet temperatures (> 1000 K) compared with using liquid sodium and lead–bismuth eutectic. Considering the mechanism of the outlet radial heat flow model, the ratio of turbulent to molecular diffusion coefficients presents a parabolic distribution along the radius of the pipe. Increasing the inlet velocity, decreasing the inlet temperature, and decreasing the wall heat flux can effectively weaken the dominant role of molecular heat transfer owing to the low Prandtl number of liquid Li. The heat transfer of liquid Li is investigated comprehensively in this study, and the results provide a basis for the practical application of liquid Li as a promising coolant.","PeriodicalId":17548,"journal":{"name":"Journal of University of Science and Technology of China","volume":"30 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83319732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

The control of moldy risk during rice storage based on multivariate linear regression analysis and random forest algorithm 基于多元线性回归分析和随机森林算法的大米储藏霉变风险控制

Journal of University of Science and Technology of China Pub Date : 2022-01-01 DOI: 10.52396/justc-2021-0118

Yurui Deng, Xudong Cheng, Fangdong Tang, Yong Zhou

{"title":"The control of moldy risk during rice storage based on multivariate linear regression analysis and random forest algorithm","authors":"Yurui Deng, Xudong Cheng, Fangdong Tang, Yong Zhou","doi":"10.52396/justc-2021-0118","DOIUrl":"https://doi.org/10.52396/justc-2021-0118","url":null,"abstract":"Clarifying the mechanism of fungi growth is of great significance for maintaining the quality during grain storage. Among the factors that affect the growth of fungi spores, the most important factors are temperature, moisture content and storage time. Therefore, through this study, a multivariate linear regression model among several important factors, such as the spore number and ambient temperature, rice moisture content and storage days, were developed based on the experimental data. In order to build a more accurate model, we introduce a random forest algorithm into the fungal spore prediction during grain storage. The established regression models can be used to predict the spore number under different ambient temperature, rice moisture content and storage days during the storage process. For the random forest model, it could control the predicted value to be of the same order of magnitude as the actual value for 99% of the original data, which have a high accuracy to predict the spore number during the storage process. Furthermore, we plot the prediction surface graph to help practitioners to control the storage environment within the conditions in the low risk region.","PeriodicalId":17548,"journal":{"name":"Journal of University of Science and Technology of China","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72918471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Event-triggered sliding mode load frequency control for multi-area interconnected power systems under deception attacks 欺骗攻击下多区域互联电力系统的事件触发滑模负荷频率控制

Journal of University of Science and Technology of China Pub Date : 2021-05-27 DOI: 10.52396/JUST-2021-0033

Liu Xinghua, Bai Dandan, Sun Baoren, Wen Jiayan, Lv Wenjun, L. Kun

引用次数: 1

Testing bubbles based on modified PWY method 基于改进PWY法的气泡测试

Journal of University of Science and Technology of China Pub Date : 2021-05-27 DOI: 10.52396/JUST-2020-1138

Ye Wuyi, Liu Weibo

引用次数: 0

Temperature predictions of a single-room fire based on the CoKriging model 基于CoKriging模型的单室火灾温度预测

Journal of University of Science and Technology of China Pub Date : 2021-05-27 DOI: 10.52396/JUST-2020-1140

She Di, Jiang Yong, Zhuang Xianli, Liang Mengjie

引用次数: 1

Measure of riskiness based on RDEU model 基于RDEU模型的风险度量

Journal of University of Science and Technology of China Pub Date : 2021-05-27 DOI: 10.52396/JUST-2021-0012

Guo Chuanfeng, Du Xinze, Wu Qinyu, Ma Tiantian

引用次数: 0