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Preparation of PVA/GO/h-BN Janus Film with High Thermal Conductivity and Excellent Flexibility via a Density Deposition Self-assembly Method

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Chinese Journal of Polymer Science 2024年第8期42卷 1217-1226页

作者： Fang-Hua Luo Zhi-tao dong Guo-Hua Chen Chen Ma Huai-Yuan Wang College of Chemistry and Chemical Engineering Northeast Petroleum UniversityDaqing 163318China College of Materials Science and Engineering Huaqiao UniversityXiamen 361000China School of Chemical Engineering and Technology and State Key Laboratory for Chemical Engineering Tianjin UniversityTianjin 300350China

Janus films with asymmetric physical/chemical properties have attracted con siderable attention due to their promising applications in personal thermal management,electronic skin s,sensors,actuators,***,traditional methods for fabricating Janus films conventionally need the assistance of an interface or auxiliary equipment,which are usually complex and ***,flexible poly(vinyl alcohol)(PVA)/graphene oxide(GO)/h-BN(recorded as PVA/GO/h-BN)Janus films with thermally,optically,and electrically anisotropic properties are fabricated by a simple density deposition self-assem bly method,which just utilizes the density difference between GO and h-BN during water *** results show that the two sides of the acquired Janus films have obvious asymmetric *** the original state of the PVA/GO/h-BN Janus films,the thermal conductivity of the GO side(10.06 W·m^(-1)·K^(-1))is generally lower than that of the h-BN side(10.48W·m^(-1)·K^(-1)).But after GO is reduced,the thermal conductivity of the rGO side reaches 12.17 W·m^(-1)·K^(-1),surpassing that of the h-BN *** addition,the relative reflectance of the h-BN side of Janus film is also significantly higher than that of the rGO side,and the su rface resistance difference between the two sides is about 4 orders of *** prepared PVA/GO/h-BN Janus films show great application potential in human thermal management,light conversion switches,and electronic *** study provides a simple and versatile strategy for fabricating Janus films with multifunctional(such as thermal,optical,and electrical)anisotropies.

关键词： Janus films PVA/GO/h-BN Density deposition self-assembly method

Investigations of methane adsorption characteristics on marine-continental transitional shales and gas storage capacity models considering pore evolution

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Petroleum Science 2024年第4期21卷 2273-2286页

作者： Chen-Gang Lu Xian-Ming Xiao Zhen-Qian Xue Zhang-Xin Chen Yin-tao dong Yue Feng Gang Li School of Energy Resources China University of Geosciences (Beijing) School of Civil and Environmental Engineering Nanyang Technological University Chemical and Petroleum Engineering University of Calgary Eastern Institute of Technology (tentative) CNOOC Research Institute

Methane adsorption is a critical assessment of the gas storage capacity(GSC) of shales with geological conditions. Although the related research of marine shales has been well-illustrated, the methane adsorption of marine-continental transitional(MCT) shales is still ambiguous. In this study, a method of combining experimental data with analytical models was used to investigate the methane adsorption characteristics and GSC of MCT shales collected from the Qinshui Basin, China. The Ono-Kondo model was used to fit the adsorption data to obtain the adsorption parameters. Subsequently, the geological model of GSC based on pore evolution was constructed using a representative shale sample with a total organic carbon(TOC) content of 1.71%, and the effects of reservoir pressure coefficient and water saturation on GSC were explored. In experimental results, compared to the composition of the MCT shale, the pore structure dominates the methane adsorption, and meanwhile, the maturity mainly governs the pore structure. Besides, maturity in the middle-eastern region of the Qinshui Basin shows a strong positive correlation with burial depth. The two parameters, micropore pore volume and non-micropore surface area, induce a good fit for the adsorption capacity data of the shale. In simulation results, the depth,pressure coefficient, and water saturation of the shale all affect the GSC. It demonstrates a promising shale gas potential of the MCT shale in a deeper block, especially with low water saturation. Specifically,the economic feasibility of shale gas could be a major consideration for the shale with a depth of 60% in the Yushe-Wuxiang area. This study provides a valuable reference for the reservoir evaluation and favorable block search of MCT shale gas.

关键词： High-pressure methane adsorption Marine-continental transitional shale gas Ono-Kondo model Adsorption thermodynamics Gas storage capacity model

Covariance matrix estimation with pipeline structure in array signal processing

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The Journal of China Universities of Posts and Telecommunications 2024年

作者： Chen Ligang Cai Weijie Liu Zhihui dong tao Zeng Hao School of Microelectronics and Communication Engineering， Chongqing University Space Star Technology Company Limited

Estimating the covariance matrix of the received signal is a vital step in array signal processing. The traditional estimation method is completed generally by offline way after receiving the continuous sampling snapshots， which can not meet requirements of real-time performance. In this paper， the calculation of covariance matrix is divided into four pipeline operations， which are multiplication， accumulation， subtraction and division， *** new method leverages the parallel computing function of field programmable gate array(FPGA) to calculate the covariance matrix adopting a pipeline estimation method at each time when the array receives a new sampling snapshot. Compared with the traditional method， the new method not only improves the real-time performance， but also reduces the error in calculation caused by the rapid direction of arrival(DOA) change of the interested signal when the target is highly maneuverable.

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Feasibility of Synchronously Straightening Working Line of Adjacent Open-cast Mines

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Asian Agricultural Research 2024年第7期16卷 28-32页

作者： Ling LIU tao dong CCTEG Shenyang Engineering Company Shenyang 110015China

Taking Heidaigou Open-cast Mine and Haerwusu Open-cast Mine in Zhungeer mining area as the research objects,this paper deeply analyzes the current mining status of the two *** on the existing working line length,mining technology,transportation system,equipment configuration,transportation access and many other factors,it systematically discusses the feasibility of straightening the working line of adjacent open-cast *** in-depth theoretical analysis,it establishes the mathematical model of impact indicators and cost calculation,and it is concluded that the work line straightening can be technically ***,from the perspective of economic benefits,straightening the working line does not show obvious advantages.

关键词： Adjacent open-cast mines Tracing the mining Working line straightening Advancing direction

Solution to the Horizontal Crossing Problem of Transportation System at Key Points in Open-Pit Mines

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Asian Agricultural Research 2024年第7期16卷 36-38,47页

作者： tao dong Ling LIU CCTEG Shenyang Engineering Company Shenyang 110015China

In order to reduce the horizontal crossing transportation problems between coal trucks and stripping trucks,large and small vehicles,and transport trucks and belt conveyors at key points of open pit mine in production,the separate transportation mode of underpass bridge and overpass steel trestle is proposed to optimize the open pit development transportation system,so as to solve the practical problems that the horizontal cross of transport vehicles causes vehicle blockage,affects production schedule and production *** results show that the horizontal crossing road can be changed into a separate type of overpass steel trestle,which can realize the classified transportation of large and small vehicles,reduce the traffic density,make vehicles with different functions go their own way,eliminate the hidden danger of traffic accidents,and improve the production efficiency.

关键词： Open-pit mines Cross-transport Underpass bridge Overpass steel trestle Production efficiency

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汉魏六朝尚方职能及其与皇权关系

史学集刊 2024年第3期 73-82页

作者：董涛重庆大学历史学系重庆400044

汉晋时期,尚方隶属少府,主要为皇帝和宫廷制器。南北朝时期,尚方机构及其职能发生变化,但南朝与北朝又有差异。南朝左尚方负责王朝军械制作,右尚方仍为宫廷制器。左尚方制军械,改变了尚方的“私奉养”性质。北朝自魏孝文帝以来,尚方改... 详细信息

汉晋时期,尚方隶属少府,主要为皇帝和宫廷制器。南北朝时期,尚方机构及其职能发生变化,但南朝与北朝又有差异。南朝左尚方负责王朝军械制作,右尚方仍为宫廷制器。左尚方制军械,改变了尚方的“私奉养”性质。北朝自魏孝文帝以来,尚方改隶太府,被纳入朝廷财政体系,制器不再仅供皇帝和宫廷使用。南北朝尚方及其职能变化,虽不尽一致,但尚方“私奉养”色彩皆渐淡化。不过,汉晋六朝尚方一直具有为皇帝和宫廷制器的职责。尚方制器被称作“御器物”“禁器物”,成为皇帝与臣民身份差异的外在体现,堪称皇权的物质象征。历朝通常禁止臣民私求或仿造尚方器物,但魏晋以降,因皇权衰落,管控力度减弱。

关键词：汉魏六朝尚方皇权私奉养少府

基于多数据集深度学习的视觉传感图像目标增强识别

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传感技术学报 2024年第1期37卷 64-70页

作者：董涛杨宝华辽东学院信息工程学院辽宁丹东118000

视觉传感图像目标的特征变化幅度普遍较大,类别间样本不均衡,为了提高视觉传感图像关键目标识别效果,提出基于多数据集深度学习的视觉传感图像目标增强识别方法。采用颜色特征提取识别目标的特征量,通过计算视觉传感图像目标与背景区域... 详细信息

视觉传感图像目标的特征变化幅度普遍较大,类别间样本不均衡,为了提高视觉传感图像关键目标识别效果,提出基于多数据集深度学习的视觉传感图像目标增强识别方法。采用颜色特征提取识别目标的特征量,通过计算视觉传感图像目标与背景区域的纹理特征差异,构建具有多特征参数的卷积神经网络模型。采用指数Laplace损失函数降低模型中类内特征变化幅度,调整不同类中心的特征间距离。结合自适应分块标记完成目标增强识别全过程。以火焰和车辆监控视觉传感图像为分析对象,设计测试实验。结果表明:所提方法的视觉传感图像增强效果较好,能够有效识别出视觉传感图像中火灾发生的异常行为和车辆的驾驶行为,且目标识别耗时低于6.2 s,证明所提方法的实际应用价值较高。

关键词：视觉传感图像卷积神经网络目标识别纹理特征差异 Laplace损失函数分块标记

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多冷媒联合冻结技术在盾构抢险中的应用

隧道建设（中英文） 2024年第S01期44卷 381-386页

作者：董涛廖先斌广东华隧高科建设有限公司广东广州511442 广东中煤江南工程勘测设计有限公司广东广州510440

为解决地层冻结加固工程加固时间长、加固效果不足的问题,提出多冷媒联合制冷的新型技术,并以珠江三角洲水资源配置某盾构刀盘更换工程为案例背景,对液氮+盐水双冷媒联合冻结方案进行介绍。从地质条件、方案设计、数值计算验证和应用效... 详细信息

为解决地层冻结加固工程加固时间长、加固效果不足的问题,提出多冷媒联合制冷的新型技术,并以珠江三角洲水资源配置某盾构刀盘更换工程为案例背景,对液氮+盐水双冷媒联合冻结方案进行介绍。从地质条件、方案设计、数值计算验证和应用效果等方面入手,对多冷媒联合冻结技术的可行性进行分析。主要结论如下:1)液氮冻结速度快但均匀性欠佳,盐水冻结速度慢但均匀性较好,二者联合冻结可以有效完成高风险地层中的盾构开舱换刀;2)液氮冻结会造成掌子面工作环境温度偏低,本案例中开挖掌子面温度低于-40℃,环境温度约-13℃,作业人员应注意低温防护;3)为保证施工效率,盾构换刀冻结工程施工应在冻结壁交圈后及时清空土舱泥浆,防止泥浆冻结。

关键词：多冷媒联合冻结盾构开舱盾构刀盘液氮冻结盐水冻结

Efficacy and safety of fecal microbiota transplantation for treatment of ulcerative colitis:A post-consensus systematic review and metaanalysis

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World Journal of Clinical Cases 2024年第21期12卷 4691-4702页

作者： Jin-tao Zhang Nan Zhang Xue-tao dong Xiao-Ran Wang Hong-Wen Ma Yan-Di Liu Mu-Ran Li Department of Clinical Medicine School of MedicineNankai UniversityTianjin 300071China Department of Gastroenterology Tianjin Union Medical CenterTianjin 300122China

BACKGROUND Numerous studies have assessed the efficacy and safety of fecal microbiota transplantation(FMT)as a therapy for ulcerative colitis(UC).However,the treatment processes and outcomes of these studies *** To evaluate the efficacy and safety of FMT for treating UC by conducting a systematic *** The inclusion criteria involved reports of adult patients with UC treated with FMT,while studies that did not report clinical outcomes or that included patients with infection were *** remission(CR)and endoscopic remission(ER)were the primary and secondary outcomes,*** We included nine studies retrieved from five electronic *** FMT group had better CR than the control group[relative risk(RR)=1.53;95%confidence interval(CI):1.19-1.94;P<0.0008].ER was statistically significantly different between the two groups(RR=2.80;95%CI:1.93-4.05;P<0.00001).Adverse events did not differ significantly between the two *** FMT demonstrates favorable performance and safety;however,well-designed randomized clinical trials are still needed before the widespread use of FMT can be ***,standardizing the FMT process is urgently needed for improved safety and efficacy.

关键词： Fecal microbiota transplantation Randomized clinical trials Remission Ulcerative colitis Meta-analysis