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Elasto-plastic fatigue crack growth analysis of plane problems in the presence of flaws using XFEM

SHEDBALE,I. V. SINGH,B. K. MISHRA

《结构与土木工程前沿（英文）》 2015年第9卷第4期页码 420-440 doi: 10.1007/s11709-015-0305-y

摘要： In this paper, elasto-plastic XFEM simulations have been performed to evaluate the fatigue life of plane crack problems in the presence of various defects. The stress-strain response of the material is modeled by Ramberg-Osgood equation. The von-Mises failure criterion has been used with isotropic hardening. The -integral for two fracture modes (mode-I and mode-II) is obtained by decomposing the displacement and stress fields into their symmetric and antisymmetric parts, then individual stress intensity factors are extracted from -integral. The fatigue life obtained by EPFM is found quite close to that obtained by LEFM.

关键词： XFEM von-Mises yield criterion isotropic hardening fatigue crack growth J-integral

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A toughness based deformation limit for X- and K-joints under brace axial tension

Bo GU,Xudong QIAN,Aziz AHMED

《结构与土木工程前沿（英文）》 2016年第10卷第3期页码 345-362 doi: 10.1007/s11709-016-0333-2

摘要： This study reports a deformation limit for the initiation of ductile fracture failure in fatigue-cracked circular hollow section (CHS) X- and K-joints subjected to brace axial tension. The proposed approach sets the deformation limit as the numerically computed crack driving force in a fatigue crack at the hot-spot location in the tubular joint reaches the material fracture toughness measured from standard fracture specimens. The calibration of the numerical procedure predicates on reported numerical computations on the crack driving force and previously published verification study against large-scale CHS X-joints with fatigue generated surface cracks. The development of the deformation limit includes a normalization procedure, which covers a wide range of the geometric parameters and material toughness levels. The lower-bound deformation limits thus developed follow a linear relationship with respect to the crack-depth ratio for both X- and K-joints. Comparison of the predicated deformation limit against experimental on cracked tubular X- and K-joints demonstrates the conservative nature of the proposed deformation limit. The proposed deformation limit, when extrapolated to a zero crack depth, provides an estimate on the deformation limits for intact X- and K-joints under brace axial loads.

关键词： circular hollow section (CHS) tubular joint fracture failure deformation limit J-integral

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species associated with eucalypt diseases in southern China

Shuaifei CHEN, Qianli LIU, Guoqing LI, Michael J. WINGFIELD

《农业科学与工程前沿（英文）》 2017年第4卷第4期页码 433-447 doi: 10.15302/J-FASE-2017173

摘要： The genus includes several important pathogens of species of and , mainly causing leaf and shoot blight. Recently, extensive shoot and leaf dieback and stem cankers suspected to be diseases have been found on young trees in Guangdong and Hainan Provinces. The occurrence of species and their association with eucalypt hosts within China needs to be investigated for tree diseases management. The isolates from the diseased samples were identified based on their morphological structures and phylogenetic analyses with DNA sequence data for the internal transcribed spacer region and large ribosome subunit RNA of the nuclear rDNA. This work revealed that three species of were present: from , from , both isolated from young eucalypt leaves and shoots in Guangdong Province, and , which was isolated from stem cankers of at four different sites across Guangdong and Hainan Provinces. These results confirmed that agents were associated with the diseases occurring on eucalypt hosts in South China. This is the first report of in Asia and the first report of in China on trees.

关键词： Corymbia Eucalyptus forest pathogens plantations Myrtaceae

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FeNi doped porous carbon as an efficient catalyst for oxygen evolution reaction

Jun-Wei Zhang, Hang Zhang, Tie-Zhen Ren, Zhong-Yong Yuan, Teresa J. Bandosz

《化学科学与工程前沿（英文）》 2021年第15卷第2期页码 279-287 doi: 10.1007/s11705-020-1965-2

摘要： Polymer-derived porous carbon was used as a support of iron and nickel species with an objective to obtain an efficient oxygen reduction reaction (OER) catalyst. The surface features were extensively characterized using X-ray diffraction, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. On FeNi-modified carbon the overpotential for OER was very low (280 mV) and comparable to that on noble metal catalyst IrO . The electrochemical properties have been investigated to reveal the difference between the binary alloy- and single metal-doped carbons. This work demonstrates a significant step for the development of low-cost, environmentally-friendly and highly-efficient OER catalysts.

关键词： OER polystyrene salt porous carbon FeNi alloy p/n junction

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Numerical investigation of the ultimate lateral resistance of piles in soft clay

TZIVAKOS,Michael J. KAVVADAS

《结构与土木工程前沿（英文）》 2014年第8卷第2期页码 194-200 doi: 10.1007/s11709-014-0251-0

摘要： The paper presents a numerical study on the undrained lateral response of a single, free-head, reinforced concrete pile in soft clays. Soil conditions simulating normally consolidated clays are examined—undrained shear strength increasing with depth—and the pile-soil interaction under static lateral loading is analyzed. The nonlinear ? curves proposed in literature for soft clays are imported into a beam-on-nonlinear-Winkler-foundation simulation in order to predict the pile head lateral load—displacement curve and the distribution of the horizontal displacement and bending moment along the pile. The striking differences among these methods require further investigation via 3D finite element analyses. The determination of the ultimate soil resistance from the results of the finite element analyses aims at providing the estimation of a range of values for the ultimate soil resistance coefficient with depth and the comparison of the derived values to the corresponding ones proposed by existing methodologies.

关键词： laterally loaded pile soft clay p?y curves finite element method (FEM)

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

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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Advances in eucalypt research in China

Yaojian XIE, Roger J. ARNOLD, Zhihua WU, Shuaifei CHEN, Apeng DU, Jianzhong LUO

《农业科学与工程前沿（英文）》 2017年第4卷第4期页码 380-390 doi: 10.15302/J-FASE-2017171

摘要： Eucalypt plantations in China currently exceed 4.5 Mhm , and this country has the third largest area of such plantations after India and Brazil. China’s eucalypt industry now comprises a complex, multifaceted industry including seedling propagation, fertilizer production and supply, plantation silviculture, harvesting and transport, wood processing for products including lumber, pulp and paper, and wood-based panels, as well as bioenergy production and various forest byproducts and non-wood forest products. In 2015, the combined value of output of this whole industry was around 300 billion CNY. Chinese research and development (R&D) has been instrumental in supporting growth and development across the whole breadth of the country’s eucalypt industry. In this report, recent advances in this R&D are reviewed under six key topics: (1) advanced propagation technology; (2) genetic resources and breeding; (3) targeted silviculture; (4) eucalypt disease and pest management; (5) enhancing plantation ecology and sustainability; and (6) wood processing and byproduct technology. R&D has greatly facilitated expansion and proliferation of all parts of China’s eucalypt industry. This industry is now of major importance to China’s economy; it involves tens of thousands of growers and companies that provide livelihoods for hundreds of thousands of people.

关键词： China Eucalypt Research Centre timber production tree improvement silviculture forest industry Eucalyptus

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Om Prakash, Stefan J. Green, Pooja Singh, Puja Jasrotia, Joel E. Kostka

《环境科学与工程前沿（英文）》 2021年第15卷第2期 doi: 10.1007/s11783-020-1315-0

摘要： Abstract • Rhodanobacter spp. are dominant in acidic, high nitrate and metal contaminated sites. • Dominance of Rhodanobacter is likely due to tolerance to low pH and heavy metals. • High organic content increases stress tolerance capacity. • Longer incubation time is critical for accurate assessment of MIC (various stresses). This work examines the physiologic basis of stress tolerance in bacterial strains of the genus Rhodanobacter that dominate in the acidic and highly metal contaminated near-source subsurface zone of the Oak Ridge Integrated Field Research Challenge (ORIFRC) site. Tolerance of R. denitrificans to levels of different stresses were studied in synthetic groundwater medium and R2A broth. Two strains of R. denitrificans, strains 2APBS1T and 116-2, tolerate low to circumneutral pH (4–8), high Uranium (1 mmol/L), elevated levels of nitrate (400 mmol/L) and high NaCl (2.5%). A combination of physiologic traits, such as growth at low pH, increased growth in the presence of high organics concentration, and tolerance of high concentrations of nitrate, NaCl and heavy metals is likely responsible for dominance of Rhodanobacter at the ORIFRC site. Furthermore, extended incubation times and use of low carbon media, better approximating site groundwater conditions, are critical for accurate determination of stress responses. This study expands knowledge of the ecophysiology of bacteria from the genus Rhodanobacter and identifies methodological approaches necessary for acquiring accurate tolerance data.

关键词： Rhodanobacter Uranium Nitrate Metals Stress tolerance

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Particle size distribution and shape control of Au nanoparticles used for particle gun

Ichiji, J. Watanabe, I. Hirasawa

《化学科学与工程前沿（英文）》 2013年第7卷第1期页码 60-64 doi: 10.1007/s11705-013-1313-x

摘要： Au nanoparticles are expected for the media to transfer genes into plants. However, the control of particle size distribution (PSD) and shape of Au nanoparticles is too difficult to design and prepare particles with suitable quality for the gene supporting media. Reduction crystallization experiments were performed in aqueous solution in order to clarify the effect of feeding conditions such as feeding profile, feeding rate, and feeding amount on PSD and shape of Au nanoparticles. Ascorbic acid (AsA) was selected as a reducing agent because it is safe for plants. Au particles of 50 nm, 50–200 nm, and 150–400 nm were obtained in batch operation, single-jet, and double-jet, respectively. Moreover, in single-jet and double-jet, the mean size of the obtained Au particles increases with the decrease of feeding rate or the increase of feeding amount. It is concluded that PSD of Au nanoparticles can be controlled in the range of 50–400 nm by changing feeding conditions of AsA and HAuCl aqueous solution.

关键词： reduction crystallization particle size distribution gene transferring media

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用高光谱发光法研究Cu(In_xi>,Ga_1–xi>)Se₂ (CIGS)模块中由P1引起的功率损耗的成因 Article

César Omar Ramírez Quiroz, Laura-Isabelle Dion-Bertrand, Christoph J.

《工程（英文）》 2020年第6卷第12期页码 1395-1402 doi: 10.1016/j.eng.2019.12.019

摘要：

在本文中，我们利用了高光谱高分辨率光致发光映射技术，这是一个强大的工具，可用于选择和优化在Cu(In_x,Ga_1-x)Se₂（CIGS）模块上对子电池进行图案化互连的激光烧蚀工艺。通过这种方式，我们可以完成对消融区域附近材料降解的深度监测以及对潜在机制的识别。具体而言，通过分析在CIGS沉积之前烧蚀的标准P1图案线，我们发现了沿着下部的钼槽边缘的异常发射猝灭效应。通过扫描电子显微镜（SEM）比较了P1边缘的横截面的形貌，我们进一步合理化产生这种效应的起因，但无法用厚度变化解释光发射的减少。我们还研究了激光诱导对CIGS沉积后的P1图案线带来的损伤。然后，我们首次记录了短距离损坏区域，该区域与在激光路径上应用的光学孔径无关。我们的发现能更好地理解P1引起的功率损耗，并为改进与行业相关的模块互连方案提供了新的见解。

关键词： Cu(Inx Ga1–x)Se2 电池到模块的效率差距由P1引起的功率损耗高光谱光致发光激光烧蚀短程热效应

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Development of a new method for RMR and Q classification method to optimize support system in tunneling

Asghar RAHMATI,Lohrasb FARAMARZI,Manouchehr SANEI

《结构与土木工程前沿（英文）》 2014年第8卷第4期页码 448-455 doi: 10.1007/s11709-014-0262-x

摘要： Rock mass classification system is very suitable for various engineering design and stability analysis. classification method is confirmed by Japan Highway Public Corporation that this method can figure out either strength or deformability of rock mass, further appropriating the amount of rock bolts, thickness of shotcrete, and size of pitch of steel ribs just after the blasting procedure. Based on these advantages of method, in this study, according to data of five deep and long tunnels in Iran, two equations for estimating the value of method from and classification systems were developed. These equations as a new method were able to optimize the support system for and classification systems. From classification and its application in these case studies, it is pointed out that the method for the design of support systems in underground working is more reliable than the and classification systems.

关键词： JH classification Q and RMR classification new method

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抗白粉病基因 Pm40i> 在我国“后 Pm21i> 时代”小麦育种中的重要作用 Perspective

唐圣雯,胡玉亭,钟胜福,罗培高

《工程（英文）》 2018年第4卷第4期页码 500-506 doi: 10.1016/j.eng.2018.06.004

摘要：

由小麦白粉菌[Blumeria graminis f. sp. tritici（Bgt）] 引起的小麦白粉病是一种重要的小麦叶部病害，对小麦的产量产生很大的影响。20 世纪80 年代，通过簇毛麦（Heuchera villosa）的6VS 染色体与小麦6AL 染色体易位将抗白粉病基因Pm21 转移到普通小麦中。最近，在一些地方发现了对Pm21 有毒的Bgt，虽然这些菌株的病理学特性还有待研究，但这一现象提醒小麦育种者应注意应用Pm21 的风险。来源于普通小麦与中间偃麦草（Thinopyrum intermedium）杂种后代的抗白粉病基因Pm40，被定位在小麦7BS 染色体上，对Bgt 具有广谱和持久的抗性。通过细胞学研究，并未在Pm40 的载体品种中发现大片段外缘染色体。过去几年的研究发现，Pm40 的载体品种具有优良的农艺性状。因此，我们相信在未来的育种工程中，Pm40 将会在Pm21 的抗性被克服之后起巨大的作用。另外，Pm21 和Pm40 都来源于外缘物种，这暗示着外源基因的抗性可能比小麦本身的基因更为持久和有效。

关键词：小麦白粉病 Pm21i> Pm40i> 外源基因内源抗性

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NiFeRuO_xi> nanosheets on Ni foam as an electrocatalyst for efficient

《化学科学与工程前沿（英文）》 2023年第17卷第11期页码 1698-1706 doi: 10.1007/s11705-023-2334-8

摘要： The electrocatalyst NiFeRuO_x/NF, comprised of NiFeRuO_x nanosheets grown on Ni foam, was synthesized using a hydrothermal process followed by thermal annealing. NiFeRuO_x/NF displays high electrocatalytic activity and stability for overall alkaline seawater splitting: 98 mV@ 10 mA∙cm⁻² in hydrogen evolution reaction, 318 mV@ 50 mA∙cm⁻² in oxygen evolution reaction, and a cell voltage of 1.53 V@ 10 mA∙cm⁻², as well as 20 h of durability. A solar-driven system containing such a bifunctional NiFeRuO_x/NF has an almost 100% Faradaic efficiency. The NiFeRuO_x coating around Ni foam is an anti-corrosion layer and also a critical factor for enhancement of bifunctional performances.

关键词： NiFeRuO_x nanosheets Ni foam electrocatalysis overall seawater splitting solar-driven system

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2014—2016年食品动物源RE-cmeABCi>阳性弯曲菌流行与耐药性现状 Article

刘德俊, 刘蔚雯, 李星, 姚红, 沈张奇, 汪洋, 沈建忠

《工程（英文）》 2020年第6卷第1期页码 34-39 doi: 10.1016/j.eng.2019.10.013

摘要：

弯曲菌是引起人类胃肠炎的一类重要食源性致病菌。RE-CmeABC是近年来弯曲菌中新发现的一种增强型耐药外排泵，可介导对兽医和人医临床治疗弯曲菌感染的重要药物，如氟喹诺酮类、酰胺醇类、大环内酯类及四环素类等药物的高水平耐药，而目前尚未有对该外排泵的大范围流行病学调查。因此，本研究调查了2014—2016年连续三年间我国山东、上海和广东等三个重点养殖区食品动物源RE-cmeABC阳性弯曲菌的流行与耐药性现状。结果显示，在1088株弯曲菌（931株结肠弯曲菌与157株空肠弯曲菌）中共检测出122株（11.2%）RE-cmeABC阳性菌株，包括111株（70.7%）空肠弯曲菌与11株（1.2%）结肠弯曲菌，空肠弯曲菌中RE-cmeABC的阳性率显著高于结肠弯曲菌。111株RE-cmeABC阳性空肠弯曲菌与46株RE-cmeABC阴性空肠弯曲菌相比在氟苯尼考、克林霉素和红霉素的耐药率上具有显著差异（P < 0.05），而在环丙沙星、四环素和庆大霉素的耐药率上无显著差异。然而，携带RE-cmeABC的菌株可以使环丙沙星与四环素对弯曲菌的MIC值分布趋于更高水平范围。脉冲场凝胶电泳分型（PFGE）结果显示RE-cmeABC阳性菌株在上海和广东地区以水平传播为主，在山东地区以克隆传播为主；三株分离于上海和广东的阳性菌为同一克隆型，4株分离于上海和山东的阳性菌为同一克隆型。本研究表明RE-cmeABC已在我国食品动物源弯曲菌中广泛流行，对公共卫生安全具有潜在威胁。

关键词： RE- cmeABC i> 弯曲菌环丙沙星氟苯尼考

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A highly efficient methodology for the preparation of

Yongxin Zhang, Shucheng Wang, Yaodong Huang

《化学科学与工程前沿（英文）》 2021年第15卷第3期页码 679-686 doi: 10.1007/s11705-020-1979-9

摘要： A convenient and highly efficient method is described for the synthesis of -methoxycarbazole derivatives, including those with sterically demanding, benzannulated, or strongly electron-donating or -withdrawing substituents. Various -methoxycarbazole derivatives were directly prepared in good-to-moderate yields by the Pd (dba) CHCl /9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene-catalyzed reactions of the corresponding dibromobiphenyl compounds and methoxya-mine. Based on this methodology, the first total synthesis of 3,3′-[oxybis(methylene)]bis(9-methoxy-9 -carbazole), an antimicrobial dimeric carbazole alkaloid previously isolated from the stem bark of , was achieved in 18% yield over seven steps from 1,2-dibromobenzene.

关键词： N-methoxyl carbazole dimeric N-methoxyl carbazole alkaloid total synthesis double N-arylation of methoxyamine