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Potassium carbonate-based ternary transition temperature mixture (deep eutectic analogues) for CO absorption: Characterizations and DFT analysis

《环境科学与工程前沿（英文）》 2022年第16卷第7期 doi: 10.1007/s11783-021-1500-9

摘要：

•Addition of hindered amine increased thermal stability and viscosity of TTTM.

关键词： Ternary transition-temperature mixture FT-IR and thermal stability analysis Viscosity and correlation study Eyring’s absolute rate theory CO₂ solubility Density functional theory (DFT).

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Effect of different high viscosity modifiers on rheological properties of high viscosity asphalt

《结构与土木工程前沿（英文）》 2021年第15卷第6期页码 1390-1399 doi: 10.1007/s11709-021-0775-z

摘要： High viscosity asphalt (HVA) has been a great success as a drainage pavement material. However, the larger porosity of drainage asphalt mixtures weakens the cohesion and adhesion and leads to premature rutting, water damage, spalling and cracking. The purpose of this study was to investigate the rheological properties of HVA prepared using different high viscosity modifiers through conventional tests, Brookfield viscosity tests, dynamic shear rheometer tests and bending beam rheometer tests. The conventional performance results demonstrated SBS + rubber asphalt (SRA-1/2) exhibited excellent elastic recovery and low-temperature flexibility. The 60°C dynamic viscosity results indicated TPS + rubber asphalt (TRA) had the excellent adhesion. The rotational viscosity results and rheological results indicated that SRA-2 not only exhibited excellent temperature stability and workability, as well as excellent resistance to deformation and rutting resistance, but also exhibited excellent low-temperature cracking resistance and relaxation performance. Based on rheological results, the PG classification of HVA was 16% rubber + asphalt for PG76-22, 20% rubber + asphalt for PG88-22, TRA and SRA-1/2 for PG88-28. From comprehensive evaluation of the viscosity, temperature stability and sensitivity, as well as high/low temperature performance of HVA, SRA-2 was found to be more suited to the requirements of drainage asphalt pavement materials.

关键词： high viscosity asphalt rheological properties rubber modifier viscosity

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Experimental study on slurry-induced fracturing during shield tunneling

Teng WANG, Dajun YUAN, Dalong JIN, Xinggao LI

《结构与土木工程前沿（英文）》 2021年第15卷第2期页码 333-345 doi: 10.1007/s11709-021-0718-8

摘要： Facial support in slurry shield tunneling is provided by slurry pressure to balance the external earth and water pressure. Hydraulic fracturing may occur and cause a significant decrease in the support pressure if the slurry pressure exceeds the threshold of the soil or rock material, resulting in a serious face collapse accident. Preventing the occurrence of hydraulic fracturing in a slurry shield requires investigating the effects of related influencing factors on the hydraulic fracturing pressure and fracture pattern. In this study, a hydraulic fracturing apparatus was developed to test the slurry-induced fracturing of cohesive soil. The effects of different sample parameters and loading conditions, including types of holes, unconfined compressive strength, slurry viscosity, and axial and circumferential loads, on the fracturing pressure and fracture dip were examined. The results indicate that the fracture dip is mainly affected by the deviator stress. The fracturing pressure increases linearly with the increase in the circumferential pressure, but it is almost independent of the axial pressure. The unconfined compressive strength of soil can reflect its ability to resist fracturing failure. The fracturing pressure increases with an increase in the unconfined compressive strength as well as the slurry viscosity. Based on the test results, an empirical approach was proposed to estimate the fracturing pressure of the soil.

关键词： slurry shield tunneling hydraulic fracturing test fracturing pressure fracture dip unconfined compressive strength slurry viscosity

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New approach to determine the plastic viscosity of self-compacting concrete

M. BENAICHA,X. ROGUIEZ,O. JALBAUD,Y. BURTSCHELL,A. Hafidi ALAOUI

《结构与土木工程前沿（英文）》 2016年第10卷第2期页码 198-208 doi: 10.1007/s11709-015-0327-5

摘要： The rheology of concrete is best measured with the use of a rheometer. The slump flow test gives a good indication of the flowability of the mixture and is therefore still used extensively to judge the workability of SCC mixtures. However, this test presents some defects. The objective of this paper is to develop a new methodology for measuring the workability of a SCC. In this article, we have proposed a correlation between the plastic viscosity of concrete, the time and the characteristics of the flow final profile from the V-funnel coupled to a Plexiglas horizontal channel. The proposed approach, verified by experimental results, represents a simple, economical and usable tool on building site, and it allows to characterize rheologically the SCC from its flow. The comparison between our approach and the experimental values of the plastic viscosity shows that, in a laboratory or on site, instead of using a rheometer we can use our approach to characterize the rheological behavior of a SCC.

关键词： rheology viscosity V-funnel flow profile rheometer behavior

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A study on specialist or special disease clinics based on big data

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《医学前沿（英文）》 2014年第8卷第3期页码 376-381 doi: 10.1007/s11684-014-0356-9

摘要：

Correlation analysis and processing of massive medical information can be implemented through big data technology to find the relevance of different factors in the life cycle of a disease and to provide the basis for scientific research and clinical practice. This paper explores the concept of constructing a big medical data platform and introduces the clinical model construction. Medical data can be collected and consolidated by distributed computing technology. Through analysis technology, such as artificial neural network and grey model, a medical model can be built. Big data analysis, such as Hadoop, can be used to construct early prediction and intervention models as well as clinical decision-making model for specialist and special disease clinics. It establishes a new model for common clinical research for specialist and special disease clinics.

关键词： big data correlation analysis medical information integration data analysis clinical model

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A critical review of ash slagging mechanisms and viscosity measurement for low-rank coal and bio-slags

Md Tanvir ALAM, Baiqian DAI, Xiaojiang WU, Andrew HOADLEY, Lian ZHANG

《能源前沿（英文）》 2021年第15卷第1期页码 46-67 doi: 10.1007/s11708-020-0807-8

摘要： Gasification or combustion of coal and biomass is the most important form of power generation today. However, the use of coal/biomass at high temperatures has an inherent problem related to the ash generated. The formation of ash leads to a problematic phenomenon called slagging. Slagging is the accumulation of molten ash on the walls of the furnace, gasifier, or boiler and is detrimental as it reduces the heat transfer rate, and the combustion/gasification rate of unburnt carbon, causes mechanical failure, high-temperature corrosion and on occasions, superheater explosions. To improve the gasifier/combustor facility, it is very important to understand the key ash properties, slag characteristics, viscosity and critical viscosity temperature. This paper reviews the content, compositions, and melting characteristics of ashes in differently ranked coal and biomass, and discusses the formation mechanism, characteristics, and structure of slag. In particular, this paper focuses on low-rank coal and biomass that have been receiving increased attention recently. Besides, it reviews the available methodologies and formulae for slag viscosity measurement/prediction and summarizes the current limitations and potential applications. Moreover, it discusses the slagging behavior of different ranks of coal and biomass by examining the applicability of the current viscosity measurement methods to these fuels, and the viscosity prediction models and factors that affect the slag viscosity. This review shows that the existing viscosity models and slagging indices can only satisfactorily predict the viscosity and slagging propensity of high-rank coals but cannot predict the slagging propensity and slag viscosity of low-rank coal, and especially biomass ashes, even if they are limited to a particular composition only. Thus, there is a critical need for the development of an index, or a model or even a measurement method, which can predict/measure the slagging propensity and slag viscosity correctly for all low-rank coal and biomass ashes.

关键词： slag viscosity biomass low-rank coal combustion gasification

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中医五脏相关学说研究——从五行到五脏相关

邓铁涛,郑洪

《中国工程科学》 2008年第10卷第2期页码 7-13

摘要：

五行学说对中医学有深刻的影响，体现了传统医学重视联系、整体的特点，但五行学说本身有局限性，不能全面地反映事物间的普遍联系。中医以五脏配属五行，吸收了五行学说的精华；又根据脏腑学说的理论，在实践中超越了五行的限制。因此，中医的理论可名为“五脏相关学说”。在中医理论现代化中，可以将五脏之间的影响归纳为促进、抑制和协同3种关系，从多种角度来阐明中医的整体性与联系观。

关键词：中医脏腑学说五行

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粘-温修正的等效粘度模型分析研究

曲庆文

《中国工程科学》 2005年第7卷第5期页码 49-52

摘要：

在等效粘度模型的基础上，考虑温度对润滑剂粘度的影响，建立了粘-温修正的等效粘度分析计算模型，并运用该模型进行薄膜润滑条件下的轴承性能分析计算，得到了不同参数下轴承性能的变化规律。

关键词：薄膜润滑粘度温度

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Crystallization and viscosity-temperature characteristics during co-gasification of industrial sludge

Linmin ZHANG, Bin LIU, Juntao WEI, Xudong SONG, Yonghui BAI, Jiaofei WANG, Ying ZHOU, Huijun YANG, Guangsuo YU

《能源前沿（英文）》 2022年第16卷第6期页码 1037-1047 doi: 10.1007/s11708-022-0824-x

摘要： Co-gasification of industrial sludge (IS) and coal was an effective approach to achieve harmless and sustainable utilization of IS. The long-term and stable operation of a co-gasification largely depends on fluidity of coal-ash slag. Herein, the effects of IS addition on the crystallization and viscosity of Shuangmazao (SMZ) coal were investigated by means of high temperature stage coupled with an optical microscope (HTSOM), a scanning electron microscopy coupled with an energy dispersive X-ray spectrometry (SEM-EDS), X-ray diffraction (XRD), a Fourier transform infrared spectrometer (FTIR), and FactSage software. The results showed that when the proportion of IS was less than 60%, with the addition of IS, the slag existed in an amorphous form. This was due to the high content of SiO₂ and Al₂O₃ in SMZ ash and blended ash, which had a high glass-forming ability (GFA). The slag formed at a high temperature had a higher polymerization degree and viscosity, which led to a decrease in the migration ability between ions, and ultimately made the slag difficult to crystallize during the cooling. When the proportion of IS was higher than 60%, the addition of IS increased the CaO and FeO content in the system. As network modifiers, CaO and FeO could provide O²⁻ at a high temperature, which reacted with silicate network structure and continuously destroyed the complexity of network structure, thus reducing the polymerization degree and viscosity of slag. At this time, the migration ability between ions was enhanced, and needle-shaped/rod-shaped crystals were precipitated during the cooling process. Finally, the viscosity calculated by simulation and Einstein-Roscoe empirical formula demonstrated that the addition of IS could significantly improve the fluidity of coal ash and meet the requirements of the liquid slag-tapping gasifier. The purpose of this work was to provide theoretical support for slag flow mechanisms during the gasifier slagging-tapping process and the resource treatment of industrial solid waste.

关键词： co-gasification industrial sludge crystallization viscosity mineral matter evolution

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指数型粘度修正模型及应用

曲庆文,王梅,柴山,姚福生

《中国工程科学》 2001年第3卷第10期页码 53-58

摘要：

根据吸附理论和分子间能量的变化规律来确定表面相互作用程度，以此可定义吸附层，得出吸附层厚度的分析计算式。吸附层厚度对研究薄膜润滑是最关键的因素，是薄膜与厚膜不同分析的关键点。根据分子相互作用的基本理论及流体力学的基本定义得出指数型粘度修正的表达式，用于确定微小间隙内流体粘度的变化规律，从而建立薄膜润滑理论模型，计算薄膜润滑轴承的特性。

关键词：吸附层粘度薄膜润滑轴承

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连续粘变条件下的速度场分析

曲庆文,王梅,陈海真,柴山,姚福生

《中国工程科学》 2002年第4卷第6期页码 29-32

摘要：

流体的流动状态将直接影响轴承的润滑特性，轴承的润滑特性主要由润滑剂的粘度决定。工作中润滑剂的粘度变化影响其运动速度的变化，从而影响润滑剂的温升及内剪切稀化的程度等。尤其在薄膜润滑中，润滑膜的厚度极小，润滑剂流体粒子间的相对运动速度增大，其润滑剂特性的变化更为突出。以连续变化的粘度修正模型来研究在微小间隙内润滑剂的速度特性，得出间隙内速度的分布规律，为研究薄膜流体温度场和剪切稀化问题提供计算数据。

关键词：薄膜润滑粘度连续模型速度

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Digital image correlation-based structural state detection through deep learning

《结构与土木工程前沿（英文）》 2022年第16卷第1期页码 45-56 doi: 10.1007/s11709-021-0777-x

摘要： This paper presents a new approach for automatical classification of structural state through deep learning. In this work, a Convolutional Neural Network (CNN) was designed to fuse both the feature extraction and classification blocks into an intelligent and compact learning system and detect the structural state of a steel frame; the input was a series of vibration signals, and the output was a structural state. The digital image correlation (DIC) technology was utilized to collect vibration information of an actual steel frame, and subsequently, the raw signals, without further pre-processing, were directly utilized as the CNN samples. The results show that CNN can achieve 99% classification accuracy for the research model. Besides, compared with the backpropagation neural network (BPNN), the CNN had an accuracy similar to that of the BPNN, but it only consumes 19% of the training time. The outputs of the convolution and pooling layers were visually displayed and discussed as well. It is demonstrated that: 1) the CNN can extract the structural state information from the vibration signals and classify them; 2) the detection and computational performance of the CNN for the incomplete data are better than that of the BPNN; 3) the CNN has better anti-noise ability.

关键词： structural state detection deep learning digital image correlation vibration signal steel frame

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Diagnosis method based on wavelet coefficient scale relativity correlation dimension for fault

GU Junjie, TIAN Jin, PENG Xuezhi

《能源前沿（英文）》 2008年第2卷第2期页码 164-168 doi: 10.1007/s11708-008-0031-4

摘要： Correlation dimension as a tool to describe machinery condition is introduced. Vibration signals of the fan under different working conditions are analyzed using a threshold filtering algorithm based on the region relativity of the wavelet coefficients for reducing noise. The result shows that the characteristics of the signal could be preserved completely. The correlation dimension is able to identify conditions of the fan with faults compared with the normal condition, thereby providing an effective technology for condition monitoring and fault diagnosis of mechanical equipment.

关键词： effective technology monitoring mechanical equipment relativity Correlation

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Marble epistyles under shear: an experimental study of the role of “Relieving Space”

E. D. PASIOU, I. STAVRAKAS, D. TRIANTIS, S. K. KOURKOULIS

《结构与土木工程前沿（英文）》 2019年第13卷第4期页码 767-786 doi: 10.1007/s11709-019-0515-9

摘要： The mechanical response of mutually interconnected epistyles is studied experimentally. The specimens are made of two marble blocks connected to each other with an “I”-shaped titanium connector placed in grooves sculptured on the blocks and covered with cementitious material. The specific way of connecting epistyles simulates the one used by scientists restoring the ancient “connections” of the epistyles of the Parthenon Temple. This “connection,” although designed to sustain mainly tensile loading, undertakes, also, shear load, in case of excitations imposing to the epistyles displacements normal to the connector’s axis. Attention is focused to enlighten the role of a novel design technique aiming to relieve the stress field around the connector. According to this technique, part of the connector’s web is left uncovered, forming the so-called “ ,” assisting the unconstrained deformation of the connector. Both traditional and innovative sensing techniques were employed in an effort to obtain data from the interior of the three-material-complex (marble-cementitious material-titanium). Analysis of the data indicated that the “Relieving Space” reduces the overall stiffness of the system, protecting marble in case of over-loading. Moreover, it was concluded that the innovative techniques employed provide pre-failure indicators well in advance of the catastrophic failure of the specimens.

关键词： monuments of cultural heritage marble epistyles pressure stimulated currents acoustic emission digital image correlation

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新型高黏度改性沥青的研发和应用

杨林江

《中国工程科学》 2008年第10卷第12期页码 92-96

摘要：

针对杭州湾大桥桥面铺装对高黏度改性沥青的技术要求，研发了一种新型高黏度改性沥青［1］。通过分析基质沥青、SBS、化学助剂的红外光谱，在研究沥青改性过程中微观结构变化规律的基础上，提出了采用SBS加化学接枝反应剂（增黏剂）TW-1和增容剂TW-2的沥青改性配伍设计，使改性沥青在提高低温延度、弹性恢复能力的同时，大幅度提升了60 ℃动力黏度，而施工和易性不受影响，产品在杭州湾大桥工程中得到了成功的应用。

关键词：杭州湾大桥高黏度改性沥青配伍机理红外光谱分析路用性能施工性能