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Analysis and design of steel-concrete composite sandwich systems subjected to extreme loads

Kazi Md Abu SOHEL, Jat Yuen Richard LIEW, Min Hong ZHANG

《结构与土木工程前沿（英文）》 2011年第5卷第3期页码 278-293 doi: 10.1007/s11709-011-0120-z

摘要： This paper presents the design guide based on analytical, numerical and experimental investigation of Steel-concrete-steel (SCS) sandwich structural members comprising a lightweight concrete core with density ranged from 1300 to 1445 kg/m subjected to static, impact and blast loads. The performance of lightweight sandwich members is also compared with similar members with normal weight concrete core and ultra high strength concrete core ( = 180 MPa). Novel J-hook shear connectors were invented to prevent the separation of face plates from the concrete core under extreme loads and their uses are not restricted by the concrete core thickness. Flexural and punching are the primary modes of failure under static point load. Impact test results show that the SCS sandwich panels with the J-hook connectors are capable of resisting impact load with less damage in comparison than equivalent stiffened steel plate panels. Blast tests with 100 kg TNT were performed on SCS sandwich specimens to investigate the key parameters that affect the blast resistance of SCS sandwich structure. Plastic yield line method is proposed to predict the plastic capacity and post peak large deflection of the sandwich plates. Finally, an energy balanced model is developed to analyze the global behavior of SCS sandwich panels subjected to dynamic load.

关键词： blast load composite structure impact load lightweight concrete sandwich plate J-hook connector

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Modeling of shear walls using finite shear connector elements based on continuum plasticity

Ulf Arne GIRHAMMAR, Per Johan GUSTAFSSON, Bo KÄLLSNER

《结构与土木工程前沿（英文）》 2017年第11卷第2期页码 143-157 doi: 10.1007/s11709-016-0377-3

摘要： Light-frame timber buildings are often stabilized against lateral loads by using diaphragm action of roofs, floors and walls. The mechanical behavior of the sheathing-to-framing joints has a significant impact on the structural performance of shear walls. Most sheathing-to-framing joints show nonlinear load-displacement characteristics with plastic behavior. This paper is focused on the finite element modeling of shear walls. The purpose is to present a new shear connector element based on the theory of continuum plasticity. The incremental load-displacement relationship is derived based on the elastic-plastic stiffness tensor including the elastic stiffness tensor, the plastic modulus, a function representing the yield criterion and a hardening rule, and function representing the plastic potential. The plastic properties are determined from experimental results obtained from testing actual connections. Load-displacement curves for shear walls are calculated using the shear connector model and they are compared with experimental and other computational results. Also, the ultimate horizontal load-carrying capacity is compared to results obtained by an analytical plastic design method. Good agreements are found.

关键词： shear walls wall diaphragms finite element modelling plastic shear connector analytical modelling experimental comparison

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Predicting the capacity of perfobond rib shear connector using an ANN model and GSA method

Guorui SUN; Jun SHI; Yuang DENG

《结构与土木工程前沿（英文）》 2022年第16卷第10期页码 1233-1248 doi: 10.1007/s11709-022-0878-1

摘要： Due to recent advances in the field of artificial neural networks (ANN) and the global sensitivity analysis (GSA) method, the application of these techniques in structural analysis has become feasible. A connector is an important part of a composite beam, and its shear strength can have a significant impact on structural design. In this paper, the shear performance of perfobond rib shear connectors (PRSCs) is predicted based on the back propagation (BP) ANN model, the Genetic Algorithm (GA) method and GSA method. A database was created using push-out test test and related references, where the input variables were based on different empirical formulas and the output variables were the corresponding shear strengths. The results predicted by the ANN models and empirical equations were compared, and the factors affecting shear strength were examined by the GSA method. The results show that the use of ANN model optimization by GA method has fewer errors compared to the empirical equations. Furthermore, penetrating reinforcement has the greatest sensitivity to shear performance, while the bonding force between steel plate and concrete has the least sensitivity to shear strength.

关键词： perfobond rib shear connector shear strength ANN model global sensitivity analysis

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大孔径光纤过渡器中光波特性分析

王云明,孙小菡,张明德

《中国工程科学》 2002年第4卷第10期页码 52-56

摘要：

提出了基于束传输法（BPM）的大孔径光纤锥形过渡器理论分析模型。讨论了过渡器在纵向边界线性和非线性情况下（包括类似正弦型和余弦型变化），分别以大小端作为输入端口，耦合角度以及耦合长度对过渡器的损耗和耦合效率的影响，得出了过渡器最佳纵向边界、耦合角度和耦合长度。

关键词：束传输法（BPM）大孔径光纤锥形过渡器插入损耗

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Immunoregulatory effects of

Dan Luo, Zhengyun Zuo, Hongyan Zhao, Yong Tan, Cheng Xiao

《医学前沿（英文）》 2019年第13卷第5期页码 556-563 doi: 10.1007/s11684-018-0649-5

摘要： Hook F (TwHF) and its extracts have long been used for the treatment of rheumatoid arthritis, autoimmune diseases, and kidney disease due to their anti-inflammatory, immunoregulatory, and other pharmacological effects. However, the clinical immunoregulatory effects of TwHF and its extracts remain unclear, so we reviewed their effects for use in clinical practice. This review provides a comprehensive summary of the recent literature on the immunoregulatory effects of TwHF and its extracts in clinical studies. TwHF and its extracts affect the proliferation and activation of T and B cells; ratio of T cell subsets; inflammatory response of monocytes, macrophages, and immunoglobulins; and secretion of many cytokines. Together, these effects dictate immune function in a variety of diseases. TwHF and its extracts can be used alone or in combination with existing therapies against many immune disorders through immunomodulation.

关键词： Tripterygium wilfordii Hook F immunoregulation clinical studies

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清洁电力技术

Robin J. Batterham

《工程（英文）》 2020年第6卷第12期页码 1349-1350 doi: 10.1016/j.eng.2020.10.004

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Measurement and correlation of supercritical CO

Hiroshi MACHIDA, Ryosuke TAGUCHI, Yoshiyuki SATO, Louw J. FLOURUSSE, Cor J. PETERS, Richard L. SMITH

《化学科学与工程前沿（英文）》 2009年第3卷第1期页码 12-19 doi: 10.1007/s11705-009-0151-3

摘要： Ionicliquids combined with supercritical fluid technology hold great promise as working solvents for developing compact processes. Ionic liquids, which are organic molten salts, typically have extremely low volatility and high functionality, but possess high viscosities, surface tensions and low diffusion coefficients, which can limit their applicability. CO , on the other hand, especially in its supercritical state, is a green solvent that can be used advantageously when combined with the ionic liquid to provide viscosity and surface tension reduction and to promote mass transfer. The solubility of CO in the ionic liquid is key to estimating the important physical properties that include partition coefficients, viscosities, densities, interfacial tensions, thermal conductivities and heat capacities needed in contactor design. In this work, we examine a subset of available high pressure pure component ionic liquid PVT data and high pressure CO - ionic liquid solubility data and report new correlations for CO -ionic liquid systems with equations of state that have some industrial applications including: (1) general, (2) fuel desulfurization, (3) CO capture, and (4) chiral separation. New measurements of solubility data for the CO and 1-butyl-3-methylimidazolium octyl sulfate, [bmim][OcSO ] system are reported and correlated. In the correlation of the CO ionic liquid phase behavior, the Peng-Robinson and the Sanchez-Lacombe equations of state were considered and are compared. It is shown that excellent correlation of CO solubility can be obtained with either equation and they share some common characteristics regarding interaction parameters. In the Sanchez-Lacombe equation, parameters that are derived from the supercritical region were found to be important for obtaining good correlation of the CO -ionic liquid solubility data.

关键词： compact processes chiral ionic liquids separations thermodynamic properties equations of state

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Merits and limitations of TiO

Yu Yang, Hassan Javed, Danning Zhang, Deyi Li, Roopa Kamath, Kevin McVey, Kanwartej Sra, Pedro J.J.

《化学科学与工程前沿（英文）》 2017年第11卷第3期页码 387-394 doi: 10.1007/s11705-017-1657-8

摘要： Heavy hydrocarbons (HHCs) in soils impacted by crude oil spills are generally recalcitrant to biodegradation due to their low bioavailability and complex chemical structure. In this study, soils were pretreated with varying concentrations of ultraviolet radiation A (UVA) or ultraviolet radiation C (UVC) activated titanium dioxide (TiO ) (1%–5%) under varying moisture conditions (0%–300% water holding capacity (WHC)) to enhance biodegradation of HCCs and shorten remediation timeframes. We demonstrate that pretreatment of impacted soils with UVC-activated TiO in soil slurries could enhance bioremediation of HHCs. ?Total petroleum hydrocarbon (TPH) removal after 24 h exposure to UVC (254 nm and 4.8 mW/cm ) was (19.1±1.6)% in slurries with 300% WHC and 5 wt-% TiO . TPH removal was non-selective in the C15-C36 range and increased with moisture content and TiO concentration. In a 10-d bioremediation test, TPH removal in treated soil increased to (26.0±0.9)%, compared to (15.4±0.8)% for controls without photocatalytic pre-treatment. Enhanced biodegradation was also confirmed by respirometry. This suggests that addition of UVC-activated TiO to soil slurries can transform recalcitrant hydrocarbons into more bioavailable and biodegradable byproducts and increase the rate of subsequent biodegradation. However, similar results were not observed for soils pretreated with UVA activated TiO . This suggests that activation of TiO by sunlight and direct addition of TiO to unsaturated soils within landfarming setting may not be a feasible approach. Nevertheless, less than 1% of UVA (7.5 mW/cm ) or UVC (1.4 mW/cm ) penetrated beyond 0.3 cm soil depth, indicating that limited light penetration through soil would hinder the ability of TiO to enhance soil bioremediation under land farming conditions.

关键词： TiO₂ pretreatment bioremediation total petroleum hydrocarbons ultraviolet

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模块化海上平台连接器的动力响应研究

何晓晖,王景全,孙宏才,李峰

《中国工程科学》 2010年第12卷第11期页码 98-104

摘要：

采用刚性模块刚性连接器（RMRC）模型对模块化海上平台连接器的动力特性进行了研究。在该模型中，将由模块拼装而成的海上平台看成一个整体结构，而连接器的载荷简化为结构相应剖面的载荷。基于三维势流理论，通过引入“高频低速”的假设，推导了低航速浮体在波浪中运动及载荷响应分析的理论和方法。计算了2种海况、4种结构尺寸、7种浪向角下结构连接器的载荷响应，得到了连接器动力响应与海况、结构尺寸及浪向角之间的关系和规律，为模块化海上平台连接器的设计及使用提供了有益的借鉴。

关键词：模块化海上平台连接器动力响应

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Ribozyme and the mechanisms that underlie RNA catalysis

Timothy J. Wilson,Yijin Liu,David M. J. Lilley

《化学科学与工程前沿（英文）》 2016年第10卷第2期页码 178-185 doi: 10.1007/s11705-016-1558-2

摘要： Ribozymes are widespread, and catalyze some extremely important reactions in the cell. Mechanistically most fall into one of two classes, using either metal ions or general acid-base catalysis. The nucleolytic ribozymes fall into the latter class, mostly using nucleobases. A sub-set of these use a combination of guanine base plus adenine acid to catalyze the cleavage reaction. New ribozymes are still being discovered at regular intervals and we can speculate on the potential existence of ribozymes that catalyze chemistry beyond phosphoryl transfer reactions, perhaps using small-molecule coenzymes.

关键词： RNA catalysis RNA structure catalytic mechanism

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烃污染土壤的热处理工艺：针对可持续修复工艺进展的综述

Masiello, Gabriel Sabadell, Pedro J. J. Alvarez

《工程（英文）》 2016年第2卷第4期页码 426-437 doi: 10.1016/J.ENG.2016.04.005

摘要：

在受烃污染的土壤和底泥的修复处理工艺中，热处理工艺因其能快速且稳定地达到修复标准而占有重要地位。然而，持续高温属于能源密集型操作，且可破坏土壤性质，因此尽管此工艺被广泛应用，关于这些工艺的环境兼容性和可持续性却极少被报道。鉴于此，我们对几个针对烃污染土壤的常用热处理工艺进行了概述，对它们的潜在环境影响进行了评估；并基于能源需求、水需求、系统生态和土壤科学的全面考虑，提出了可持续且影响较小的发展框架。至今还没有一种通用适合的热处理工艺。工艺的恰当选择要根据污染状况( 包括环境中存在的烃种类) 和场地特征( 如被污染土壤的性质、水含量和热敏性) 而定。总之，处理工程与土壤科学、生态系统和植物生物学研究的有机结合是攻克技术瓶颈、提高去除率和促进热处理工艺可持续性发展的关键所在。

关键词：土壤分解土地改良焚烧裂解解吸

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Aseismic smart building isolation systems under multi-level earthquake excitations: Part I, conceptual design and nonlinear analysis

Min-Ho CHEY,J. Geoffrey CHASE,John B. MANDER,Athol J. CARR

《结构与土木工程前沿（英文）》 2015年第9卷第3期页码 286-296 doi: 10.1007/s11709-015-0307-9

摘要： As a novel structural control strategy, tuned mass damper (TMD) inspired passive and semi-active smart building isolation systems are suggested to reduce structural response and thus mitigate structural damage due to earthquake excitations. The isolated structure’s upper stories can be utilized as a large scaled TMD, and the isolation layer, as a core design point, between the separated upper and lower stories entails the insertion of rubber bearings and (i) viscous dampers (passive) or (ii) resettable devices (semi-active). The seismic performance of the suggested isolation systems are investigated for 12-story reinforced concrete moment resisting frames modeled as “10+ 2” stories and “8+ 4” stories. Passive viscous damper or semi-active resettable devices are parametrically evaluated through the optimal design principle of a large mass ratio TMD. Statistical performance metrics are presented for 30 earthquake records from the three suites of the SAC project. Based on nonlinear structural models, including P-delta effects and modified Takeda hysteresis, the inelastic time history analyses are conducted to compute the seismic performances across a wide range of seismic hazard intensities. Results show that semi-active smart building isolation systems can effectively manage seismic response for multi-degree-of freedom (MDOF) systems across a broader range of ground motions in comparison to uncontrolled case and passive solution.

关键词： tuned mass damper smart building isolation resettable device non-linear statistical assessment

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Purification of

PIETZSCH, J. ULRICH

《化学科学与工程前沿（英文）》 2013年第7卷第1期页码 37-42 doi: 10.1007/s11705-013-1303-z

摘要： Here a case study of -asparaginase II out of a recombinant is presented. The target protein was obtained by simple cell disintegration and acetone precipitation. The -asparaginase II has been crystallized in three different forms in the following microbatch crystallization. The rod-shaped crystals (~400 μm edge length) were obtained at either 8°C or 22°C after 17 h by addition of PEG . The rectangular-shaped crystals were obtained after further recrystallization of the rod-shaped crystals. The rhombic-shaped crystals formed at 8°C after 12 days when cold ethanol was used instead of PEG . All crystallizations were performed in tris-acetate buffer (50 mmol·L , pH 5.1). By crystallization, the specific activity of -asparaginase II has increased 5-fold. The protein content and the purity of the crystals were evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The more concentrated -asparaginase II out of an extract mixture and the presence of only less minor proteins after crystallization demonstrates that crystallization is an effective and mild method to purify the target protein. The single crystal X-ray diffraction pattern reveals that the crystals are proteins and the X-ray powder diffraction (XRPD) pattern shows clearly that the crystals forming in PEG and ethanol have different crystal structures.

关键词： protein crystallization L-asparaginase II purification