Transient parametric pilot study on thermosyphon heat transport device: A computational fluid dynamics hypothesis and experimental exploration

This study aims to examine the practicality of a novel passive heat transport system “thermosyphon heat transport device” (THTD). It is a fluid-filled unit, with both source and sink amalgamated within it. A vertical tube-in-tube design has been incorporated, consisting of heat source, adiabatic height, and sink. To showcase the performance, a transient numerical analysis is performed using ANSYS Fluent, which is compared with the simple closed thermosiphon (SCT) for heat transport capability (1 kW) and different adiabatic heights (0.25, 1, and 1.5 m). Also, the influence of axial conduction is examined. The proposed Therminol VP1-based THTD has better heat transport capability over SCT due to a uniform flow pattern. Although the time response diminishes with adiabatic height, the novelty is justified as the heat gained by THTD (adiabatic height: 1.5 m) is 1.5 times more than SCT. Furthermore, the THTD performance is experimentally analyzed by varying the coolant flow rate (0.01, 0.02, and 0.03 kg/s), heat load (100−600 W), and transport distance (0.25 and 0.75 m), which yielded 80%−90% energy efficiency. As the THTD is crucial for a conceptual solar indoor cooker, the response under transient heating/cooling conditions is also investigated, which depicted 300 s for transient heating and 10−50 s for transient cooling.     

How do the internet technological developments shift the consumption pattern of paper products? Evidence from China

Using a monthly data between 2008 and 2019, this study investigated how the development of the Internet technologies has shaped the consumer consumption pattern of different types of paper products in China during this period. In detail, this study covers four major types of paper products in the Chinese market: newsprint, printing paper, household paper, and packaging paper. The developments of Internet technologies were decomposed into two aspects: the communication technology (CT) and the software platform technology (PT). Granger causality analysis was employed to determine whether the consumption pattern of paper products was affected by the development of the Internet. Furthermore, impulse-response analyses were utilized to measure how the consumption pattern of each paper product was shaped by the development of each aspect of Internet technologies, i.e., CT or PT. The empirical results suggested that the Internet developments are causing the consumption patterns shifts of all four paper products. Specifically, the consumptions of newsprint and printing paper were driven by both CT and PT. However, the consumptions of packaging paper and household paper were driven by the PT only. Compared to the development of CT, we found that the quick evolution of PT plays a more significant role in shifting people's consumption of paper products in China. The empirical results revealed by this study could provide valuable economics and policy implications to both academia and relevant industries.     

Research on image segmentation of Miao costume patterns based on the RSKP-UNet model北大核心CSCD

The Miao nationality is the sixth largest ethnic group in China which has a history of thousands of years. It has created a unique material culture and spiritual culture in its development process and the Miao costume is a highly condensed collection of the material and spiritual culture of the Miao nationality. As one of the unique symbols of Miao culture the Miao costume has profound cultural heritage and cultural connotations. The patterns of the Miao costume are particularly eye-catching as they not only symbolize the wisdom of the Miao people in thousands of years of production and life but also symbolize the pursuit of the good spirit of the Miao people. However under the impact of modern pop culture and foreign culture these cultural symbols are gradually disappearing. In order to protect and inherit them the Miao costume pattern segmentation has become the most important work. However the Miao costume pattern segmentation is quite difficult. At present there are few studies on the extraction classification identification and preservation of the features of Miao costume pattern segmentation. With the excellent segmentation performance of the U-Net model and the advantages of easy deployment the paper improves the basic structure of the U-Net model and proposes a Miao costume pattern segmentation algorithm based on the RSKP-UNet Residual Selective-Kernel Parallel U-Net model. The algorithm adds Residual modules in the encoder part of the U-Net model to improve the feature extraction capability of the model and embeds the SKNet modules and ParNet modules in the decoder part to enhance the feature expression capability of the model. The paper uses evaluation metrics to measure the segmentation performance of the model and compares it with four segmentation models based on deep learning. The paper not only combines the current research focus-deep learning and attention mechanism but also introduces the Lovász-hinge loss function to effectively solve the problem of class imbalance in the Miao costume patterns. The RSKP-UNet model is better than other models in various segmentation indicators. Compared with the benchmark model U-Net the Dice coefficient IoU precision recall and accuracy are improved by 6. 98% 11. 07% 2. 89% 6. 75% and 3. 92% . The segmentation algorithm proposed in this paper realizes the extraction of the element content of the Miao costume patterns through image segmentation of Miao costume patterns which can be used to build the Miao costume pattern database in this way thus helping designers relevant researchers and organizations to provide research foundation and completing the protection and inheritance of the Miao costume culture. The paper also provides some reference for the segmentation research of other minority costume patterns. © 2022 Authors. All rights reserved.     

沿对角线方向倾倒爆破拆除楼房

在楼房爆破拆除中,根据待拆楼房的围围环境,采用了沿楼房对角线方向定向倾倒拆除的方案,并取得了成功。文中介绍了爆破方案、布孔方法及具体的爆破参数。     

激光散斑干涉技术的应用

散斑干涉计量就是根据与物体变形有内在联系的散斑图，将物体表面位移或变形测量出来。介绍了激光散斑干涉技术的物理学基础、检测方法及其应用。说明它是一种非常便捷、先进、并具有发展潜力的光测技术。     

露天矿垂直与斜深孔爆破特征分析

根据永平铜矿实际爆破情况,运用爆轰理论,对露天矿垂直与倾斜两种中深孔的爆破特征进行了分析.分析从底盘抵抗线、孔网参数、大块与粮底、钻孔效率与作业成本和爆破地震效应五个方面入手,阐述了两种不同类型钻孔的不同爆破作用机制及其爆玻效果,肯定了倾斜孔在露天台阶爆破中所具有的独特优越性.     

鄂西南岩溶水的基本特征及分布规律

鄂西南山区岩溶水丰富,作为国家西部开发的重点地区之一,寻找到、利用好岩溶水资源,有利于鄂西南山区的经济发展。概述鄂西南山区地质背景及地貌特征,对岩溶水的基本特征、岩溶水水动力类型及地下暗河的发育分布规律进行分析论述。     

基于模糊模式识别的煤与瓦斯突出区域预测

借助于成熟的模糊理论与技术可以较客观地实现突出预测中不精确信息与不精确关系的正确表达与处理，综合考虑突出影响因素，提出了煤与瓦斯突出区域预测的模糊模式识别新方法.首先采用模糊聚类分析对煤与瓦斯突出的样本集合进行分类，建立不同程度的模糊模式.然后对待预测样本进行模糊模式识别，根据择近原则，哪一种模式与预测样本最接近，待预测样本即属于哪一种突出类型.此方法克服了模糊聚类单一分析方法的不确定性，实现了多指标定量化的预测，提高了预测效果的准确程度.通过实例验证，证明了预测的可靠性.     

煤矿区土地利用景观格局变化分析

利用遥感数据对煤矿区进行景观格局及变化研究,具有十分重要的意义。选择唐山市古冶区为研究对象,以3个时相（1987年、1992年和2001年）遥感图像为数据源,利用ENVI对图像进行预处理和人机交互解译,获取3期遥感图像的土地利用/覆盖分类图,同时获取各土地利用/覆盖类型的像元数。选取斑块的规模特征、斑块的形状特征、景观多样性指标、空间异质性指标进行计算,并进行景观格局变化分析。     

高宝山金矿区断裂构造特征及控矿成矿因素的探讨

从高宝山金故区断裂构造的规模，形态，产状、力学性质等方面，阐述了断裂构造与控矿成矿的关系，提出了从断层构造特征，成矿地质条件，成矿模式分析等方面指导找矿方向。