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防治煤自燃的高堆积固化泡沫的制备及应用

煤炭科学技术 2024年第2期52卷 159-170页

作者：胡相明王凯薛迪孙公正山东科技大学安全与环境工程学院山东青岛266590 山东科技大学矿山灾害预防控制省部共建国家重点实验室培育基地山东青岛266590

漏风是引发矿井煤自燃的重要原因,而煤自燃火灾影响了矿井的正常生产。为解决传统无机固化泡沫(TISF)在充填堵漏过程中存在胶凝时间长、堆积能力弱的问题,提出经液态硅酸钠(LSS)改性制备的速凝无机固化泡沫(RISF)。研究了不同掺量的LSS... 详细信息

漏风是引发矿井煤自燃的重要原因,而煤自燃火灾影响了矿井的正常生产。为解决传统无机固化泡沫(TISF)在充填堵漏过程中存在胶凝时间长、堆积能力弱的问题,提出经液态硅酸钠(LSS)改性制备的速凝无机固化泡沫(RISF)。研究了不同掺量的LSS对泡沫浆液胶凝时间、堆积能力等性能的影响规律,采用抗压强度、稳定性测试等表征手段,确定了LSS的最优添加量为5%(质量分数),RISF的28 d抗压强度达2.49 MPa,是TISF的1.7倍,最大密度比R为1.11,稳定性提升20%左右;胶凝时间和堆积能力的测试结果表明,与TISF相比,RISF的凝结时间大幅缩短(从683 s缩短到52 s),堆积能力提升(最大堆积高度提高1.9倍)。基于此,结合扫描电子显微镜(SEM)和X射线衍射(XRD)对RISF的速凝固化机理进行了探究。试验结果表明,RISF具有更多的水化产物且不同的水化产物紧密交织,颗粒水化过程中,LSS水解生成原硅酸根与溶液中的钙离子结合,加快水化反应,缩短了泡沫浆液的胶凝时间。但也发现,当LSS添加量超过5%时,RISF的抗压强度降低,稳定性下降,这主要是因为过量的LSS使溶液中的钙硅比例低于1.0,导致生成了低强度的水化产物。堵漏风试验和灭火试验结果表明,与TISF相比,RISF具有较高的堵漏效率和优良的防灭火性能,堵漏效率最高提升26.3%,并且在扑灭煤火时未出现复燃。RISF在利民煤矿矸石山的现场应用表明,其具有良好的降温灭火效果,有效解决了矸石山的高温难题,确保了矿井的正常生产。

关键词：煤自燃无机固化泡沫快速凝固机理充填堵漏材料

Experimental verification of generalized eigenstate thermalization hypothesis in an integrable system

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Light(Science & Applications) 2022年第7期11卷 1615-1624页

作者： Qin-Qin Wang Si-Jing Tao Wei-Wei Pan Zhe Chen Geng Chen kai sun Jin-Shi Xu Xiao-Ye Xu Yong-Jian Han Chuan-Feng Li Guang-Can Guo CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Identifying the general mechanics behind the equilibration of a complex isolated quantum system towards a state described by only a few parameters has been the focus of attention in non-equilibrium thermodynamics.And several experimentally unproven conjectures are proposed for the statistical description of quantum(non-)integrable models.The plausible eigenstate thermalization hypothesis(ETH),which suggests that each energy eigenstate itself is thermal,plays a crucial role in understanding the quantum thermalization in non-integrable systems;it is commonly believed that it does not exist in integrable systems.Nevertheless,integrable systems can still relax to the generalized Gibbs ensemble.From a microscopic perspective,understanding the origin of this generalized thermalization that occurs in an isolated integrable system is a fundamental open question lacking experimental investigations.Herein,we experimentally investigated the spin subsystem relaxation in an isolated spin-orbit coupling quantum system.By applying the quantum state engineering technique,we initialized the system with various distribution widths in the mutual eigenbasis of the conserved quantities.Then,we compared the steady state of the spin subsystem reached in a long-time coherent dynamics to the prediction of a generalized version of ETH and the underlying mechanism of the generalized thermalization is experimentally verified for the first time.Our results facilitate understanding the origin of quantum statistical mechanics.

关键词： integrable quantum state

基于观测方程重构滤波算法的锂离子电池荷电状态估计

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电工技术学报 2024年第7期39卷 2214-2224页

作者：黄凯孙恺郭永芳王子鹏李森茂省部共建电工装备可靠性与智能化国家重点实验室(河北工业大学) 天津300130 河北工业大学人工智能与数据科学学院天津300130

滤波算法中观测方程的准确性在电池状态评估中起着决定性作用。然而,该文通过试验发现,由于温度、工作电流和荷电状态(SOC)的影响,即使使用精度较高的电池模型,扩展卡尔曼滤波(EKF)算法中观测方程的输出值与实际电压之间仍会存在较大误... 详细信息

滤波算法中观测方程的准确性在电池状态评估中起着决定性作用。然而,该文通过试验发现,由于温度、工作电流和荷电状态(SOC)的影响,即使使用精度较高的电池模型,扩展卡尔曼滤波(EKF)算法中观测方程的输出值与实际电压之间仍会存在较大误差,即产生了较大的新息。该文提出一种基于观测方程重组的增强型扩展卡尔曼滤波(E-EKF)算法。该算法的核心思想是利用具有温度、SOC和电流自适应能力的误差修正策略对观测方程进行重组,实现算法中新息的降低,进而提高SOC估计的准确性。使用两种不同温度下的典型工况试验对E-EKF算法的性能进行了验证。试验结果表明,该算法能够适应不同的温度和工况,并具有较高的SOC估计精度。

关键词：扩展卡尔曼滤波算法误差修正方程观测方程重组 SOC 估计

Evolvable dialogue state tracking for statistical dialogue management

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Frontiers of Computer Science 2016年第2期10卷 201-215页

作者： kai YU Lu CHEN kai sun Qizhe XIE Su ZHU Key Laboratory of Shanghai Education Commission for Intelligent Interaction and Cognitive EngineeringSpeechLab Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China Department of Computer Science Cornell University Ithaca NY 14853 USA

Statistical dialogue management is the core of cognitive spoken dialogue systems （SDS） and has attracted great research interest. In recent years, SDS with the ability of evolution is of particular interest and becomes the cuttingedge of SDS research. Dialogue state tracking （DST） is a process to estimate the distribution of the dialogue states at each dialogue turn, given the previous interaction history. It plays an important role in statistical dialogue management. To provide a common testbed for advancing the research of DST, international DST challenges （DSTC） have been organised and well-attended by major SDS groups in the world. This paper reviews recent progresses on rule-based and statistical approaches during the challenges. In particular, this paper is focused on evolvable DST approaches for dialogue domain extension. The two primary aspects for evolution, semantic parsing and tracker, are discussed. Semantic enhancement and a DST framework which bridges rule-based and statistical models are introduced in detail. By effectively incorporating prior knowledge of dialogue state transition and the ability of being data-driven, the new framework supports reliable domain extension with little data and can continuously improve with more data available. This makes it excellent candidate for DST evolution. Experiments show that the evolvable DST approaches can achieve the state-of-the-art performance and outperform all previously submitted trackers in the third DSTC.

关键词： dialogue management domain extension,evolvable dialogue state tracking parser tracker

Particle packing theory guided multiscale alumina filled epoxy resin with excellent thermal and dielectric performances

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Journal of Materiomics 2022年第5期8卷 1058-1066页

作者： Qi-Kun Feng Chang Liu Dong-Li Zhang Yan-Hui Song kai sun Hai-Ping Xu Zhi-Min Dang State Key Laboratory of Power System Department of Electrical EngineeringTsinghua UniversityBeijing100084China School of Chemistry and Chemical Engineering Xi'an University of Science and TechnologyXi'an710054China Shanghai Engineering Research Center of Advanced Thermal Functional Materials Shanghai Polytechnic UniversityShanghai201209China

Polymers and composites with high thermal conductivity are promising yet challenging for the growing demand of thermal management in electrical and electronic equipment.Guided by the closest packing model,a multiscale filling Al_(2)O_(3) strategy was designed and incorporated with epoxy resin(EP)to form high thermal conductive composites in this work.Epoxy composites with single filler loading were also prepared.The microstructures,thermal,rheological,and dielectric characteristics of the multiscale filling Al_(2)O_(3)/EP composites have been investigated.Compared with single-scale Al_(2)O_(3) filled epoxy based composites,it is found that the multiscale filling Al_(2)O_(3)/EP composites exhibit higher thermal conductivity under the same filler loading of 50 vol%,which is attributed to the efficient heat conduction paths formed by appropriate multiscale fillers.Particularly,a remarkably improved thermal conductivity of 2.707 W m^(-1) K^(-1) was acquired in Al_(2)O_(3)/EP composites at filler loading of 50 vol%(5 mm Al_(2)O_(3)(26.67 vol%),30 mm Al_(2)O_(3)(27.41 vol%)and 70 mm Al_(2)O_(3)(45.92 vol%)),which is about 1300%higher than that of the pure epoxy resin.In addition,the dielectric constant of the Al_(2)O_(3)/EP composites were significantly improved while keeping the dielectric loss almost unchanged.The finite element simulation further verified the effectiveness of improving the thermal conductivity of materials in the heat dissipation of electrical equipment.Therefore,this research provides a simple strategy for manufacturing high thermal conductive composite materials with a wide range of potential applications as packaging materials.

关键词： Closest packing model Epoxy composites Alumina Thermal conductivity Dielectric property

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引力透镜时间延迟研究进展

科学通报 2024年第1期69卷 80-95页

作者：廖恺武汉大学物理科学与技术学院武汉430072

引力透镜效应是天文学研究经常用到的重要工具.这个效应中一个有趣的现象是同一天体源在某些情形下能够产生多个像.这些像依次到达地球并被人们观测到.它们之间的到达时间差称为时间延迟,携带着丰富的天文学信息.针对不同的天体源,人们... 详细信息

引力透镜效应是天文学研究经常用到的重要工具.这个效应中一个有趣的现象是同一天体源在某些情形下能够产生多个像.这些像依次到达地球并被人们观测到.它们之间的到达时间差称为时间延迟,携带着丰富的天文学信息.针对不同的天体源,人们发展出特定的观测策略和算法来测量时间延迟.传统的时间延迟观测源为透镜化的类星体.它们的时间延迟是通过对比光变曲线来测量的.在韦布望远镜时代,类星体时间延迟将给出准确的哈勃常数测量值,以期解决当前“哈勃常数争论”.同时,随着时域天文学时代的开启,透镜化的瞬变源,例如各类型的超新星、伽马射线暴及其余辉、快速射电暴和引力波也将被人们大量观测到.对于这些源,时间延迟测量有可能变得更加容易和准确.瞬变源透镜系统将带给我们更多关于引力本性、暗物质性质以及宇宙膨胀的信息.本文基于国内外在时间延迟领域的最新研究进展,介绍了时间延迟的测量方法、测量现状以及它在检验基础物理、研究天体物理和宇宙学方面的应用.

关键词：引力透镜时间延迟类星体瞬变源宇宙学

Characteristics of B,Zn and Se in stream sediments of Tanzania and their agricultural applications:Based on 1∶1000000 geochemical survey

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China Geology 2023年第1期6卷 1-14页

作者： Kang-kang Xu Hong-wei sun Wei Xie Fu-qing He Xiao-yang Liu kai sun Sheng-fei He Xing-yuan Wu Peng-hui Gong Godfrey Machumu Southern African Mining Research Institute China Geological SurveyTianjin 300170China North China Center of Geoscience Innovation Tianjin 300170China Tianjin Geological Mineral Testing Center Tianjin 300191China Geological Survey of Tanzania DodomaP.O Box 903Tanzania

Tanzania is located in eastern Africa with a predominantly agricultural ecomomy,the potential for developing and utilizing cultivated land are promising,but scientific guidance is required.B,Zn and Se are essential micronutrients for plants and human body with crucial biological functions,in particular,Se is significant for human health and considered as“the king of anti-cancer”.As these elements required by human or plants are mainly absorbed from soil directly or indirectly,therefore,it is important to understand the contents and distributions of them in the soil of cultivated land for guiding agricultural production.In this work,low-density geochemical survey at the scale of 1∶1000000 was carried out in Tanzania,and the results show that the concentrations of B,Zn and Se in stream sediments are low and their distributions are heterogeneous.According to the distributions of geological units,the existing cultivated land resources can be divided into five regions in Tanzania.Compared with the national background values,the concentrations of B,Zn and Se are insufficient overall but enriched locally in these regions.In general,element concentrations in stream sediments and soil have a positive correlation because of their similar sources,which is essential in agriculture application.Based on the information provided by low-density geochemical data and maps,the Se-sufficient and Se-rich regions were delineated in Tanzania,where can be used to develop Se-rich industries.Finally,this paper believes that geochemical survey is a powerful tool for cultivated land evaluation,agriculture management and land development.

关键词： Stream sediment Low-density geochemical survey Geochemical map Soil of cultivated land Agricultural applications Agricultural geological survey engineering Tanzania Selenium-rich agricultural products

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复杂环境下的轻量化道路目标识别算法研究

计算机工程 2024年第4期50卷 219-227页

作者：李振鲁黄威孙锴内蒙古大学电子信息工程学院内蒙古呼和浩特010021

道路目标识别是智能交通系统解决城市拥堵问题的核心技术之一,然而现有算法在复杂交通环境下识别效果较差,存在大量漏检和误检情况,且模型参数量大,不适合在实际场景下部署于资源有限的移动端设备。针对以上问题,提出一种复杂环境下的... 详细信息

道路目标识别是智能交通系统解决城市拥堵问题的核心技术之一,然而现有算法在复杂交通环境下识别效果较差,存在大量漏检和误检情况,且模型参数量大,不适合在实际场景下部署于资源有限的移动端设备。针对以上问题,提出一种复杂环境下的轻量化道路目标识别算法。基于SSD算法结构设计一种可重构的特征提取网络框架,利用3种轻量化模块分别构建浅层特征提取网络,以自定义的Additional Block构建深层特征提取网络,并分别采用通道注意力机制和轻量化感受野扩大(RFB-L)模块提升模型对各尺寸目标的检测效果。利用自定义的像素与通道信息融合模块实现浅层与深层特征的融合,丰富待检测特征图包含的信息。同时,提出一种多特征融合的学习率调节算法,使得训练过程中模型性能稳定地达到收敛。自制复杂拥堵道路数据集Hohhot_city用于算法训练和测试,与主流算法的对比实验结果表明,该算法性能明显优于参数量同级别的YOLOv4-tiny和YOLOv5s算法,在参数量不到YOLOv5m算法40%的情况下与其检测精度接近,并取得了12.8 ms的推理时间和99.1%的均值平均精度。

关键词：道路目标识别特征提取特征融合通道注意力感受野

Advances in selective catalytic oxidation of ammonia (NH_(3)-SCO): A review of catalyst structure-activity relationship and design principles

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Chinese Chemical Letters 2024年第1期35卷 169-180页

作者： Zhao Li Chunxue Wang Junjun Qiu Yixing Ma Chi Wang Xin sun kai Li Ping Ning Fei Wang Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500China National-Regional Engineering Center for Recovery of Waste Gases from Metallurgical and Chemical Industries Kunming 650500China Faculty of Chemical Engineering Kunming University of Science and TechnologyKunming 650500China

NH_(3) in ambient air directly leads to an increase in the aerosol content in the air. These substances lead to the formation of haze to various environmental problems after atmospheric circulation and diffusion. Controlling NH_(3) emissions caused by ammonia escaping from mobile and industrial sources can effectively reduce the NH_(3) content in ambient air. Among the various NH_(3) removal methods, the selective catalytic oxygen method (NH_(3)-SCO) is committed to oxidizing NH_(3) to environmentally harmless H_(2)O and N_(2);therefore, it is the most valuable and ideal ammonia removal method. In this review, the characteristics of loaded and core-shell catalysts in NH_(3)-SCO have been reviewed in the context of catalyst structure-activity relationships, and the H_(2)O resistance and SO2 resistance of the catalysts are discussed in the context of practical application conditions. Then the effects of the valence state of the active center, oxygen species on the catalyst surface, dispersion of the active center and acidic sites on the catalyst performance are discussed comprehensively. Finally, the shortcomings of the existing catalysts are summarized and the catalyst development is discussed based on the existing studies.

关键词： Ammonia Selective catalytic oxidation Active metals and supports Influence of gas composition Reaction mechanism Catalyst structure-activity relationship