Effects of Particle Sizes of Rock Phosphate on Heavy Metals Uptake by Lolium Prenne, L in Pb-Zn Mine Soils

Zhongqiu Zhao 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Collaborative fabrication of poly(L-proline)s with well-defined mesopores and hydrophobicity: Synergistic effect of mesoporous confinement and hydrophobic micro-environment on organic transformations

Zhongqiu Liu,Yuanyuan Yu,Shengnan Li,Yaqi Liu,Guoqiang Zhang,Long Han,Yujing Liu,Jinmao You,Anguo Ying 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

The preparation of materials with a well-defined mesoporous structure and hydrophobicity is of greatsignificance for heterogeneous catalyst development, yet there still remains a challenge for fabricatingthe above materials without using templates. Herein, the polymerization of L-proline-functionalizedmonomer with crosslinkers containing variable alkyl-bridged length (n = 2,4,6,8) and vinyl-modifiedFe3O4 nanoparticles to construct mesoporous poly(L-proline)s (MPLPs) has been reported for the firsttime. The resultant MPLPs were analyzed by characterization methods, suggesting that MPLPs with awell-defined mesoporous structure and unique hydrophobicity were successfully constructed by synergisticregulation of vinyl-modified Fe3O4 nanoparticles and crosslinkers with alkyl-bridged length of 6carbon atoms, in which vinyl-modified Fe3O4 nanoparticles as structural reinforcer plays a vital rolefor the mesoporous formation. Moreover, the resultant MPLPs were found to be efficient catalysts forone-pot synthesis of functionalized spiroindolones and olefins. The kinetic study and the water contactangle indicate the mesoporous confinement and hydrophobic micro-environment in organic transformations. Hence, the high activity of MPLPs is ascribed to synergistic effect of mesoporous confinement andhydrophobic micro-environment, and the adsorption experiment results further confirm this synergisticcatalysis. This work promotes a textural engineering approach to the development of multifunctionalmaterials with well-defined mesopores and hydrophobicity.

Bending Performance of Lightweight Aggregate Concrete-filled Steel Tube Composite Beam

Zhongqiu Fu,Qiudong Wang,Yixun Wang,Bohai Ji 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.10

A composite beam, which consists of a Lightweight Aggregate Concrete Filled Steel Tube (LACFST), and a reinforced concrete slab deck, was investigated. Bending tests were performed to study its behaviour. Based on the test results and the assumptions therein, calculation methods proposed and design suggestions were proved by finite element analysis. The results shows that the composite beam had good ductility and high bearing capacity. The design bearing capacity can be calculated using a force balance method. The flexural stiffness, at the serviceability-level, can be found by superposition of the slab deck and LACFST beam stiffness. A three-line M-δ model was proposed for the lightweight aggregate concrete steel tube composite beam moment – deflection evolution. After validation by finite element analysis, the neutral axis was suggested as lying between the top of the steel tube and the bottom of the concrete deck when the composite beam failed.

Fatigue Evaluation of Cable-stayed Bridge Steel Deck Based on Predicted Traffic Flow Growth

Zhongqiu Fu,Bohai Ji,Zhi Ye,Yixun Wang 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.4

Statistical analysis of the measured traffic flow over the Nanjing No. 3 Yangtze River Bridge from 2006 to 2010 was conducted. The predictions of traffic flow growth model were established. Random traffic flow was simulated by Monte-Carlo method to study dynamic impact effects under vehicle load. Considering the dynamic impact effects and wheel mark transverse distribution, the nominal stress, hot spot stress, and notch stress in the steel bridge deck details was calculated. The results of three evaluation method were compared. Suggestions of analysis models and fatigue evaluation were proposed. The study showed that the maximum magnification coefficient of the dynamic impact effects was close to the suggestion of BS5400. The simplified model could be used to analysis local stress ignoring the superimposed effects of longitudinal multi-vehicles. The evaluated service life under hot spot stress was comparatively longer. In terms of bridge safety and convenience, notch stress for the roof weld and U rib-to-diaphragm weld and hot spot stress for diaphragm arc gap were more suitable for fatigue evaluation. And the roof weld was most likely to crack.

Experimental Study on the Fatigue Performance of Roof and U-rib Welds of Orthotropic Steel Bridge Decks

Zhongqiu Fu,Bohai Ji,Chengyi Zhang,Di Li 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.1

The fatigue performance of a roof-U rib weld on orthotropic steel bridge decks was studied by fatigue experiments on 40 specimens, considering the influences of amplitude, penetration rate, loading position, and steel strength. Influences of different factors on the fatigue life of crack initiation and specimen failure were studied by analysis of crack propagation in the weld and changes in stress amplitude. In addition, nominal stress amplitudes and hot spot stress amplitudes of the welds were compared and the suggested values of fatigue strength were proposed according to the test results. The study shows that increase of penetration rate can decrease the crack propagation rate and extend failure fatigue life. A larger steel strength can increase the fatigue strength of crack initiation. Under the same loading conditions, the fatigue life of crack initiation is about half of the failure fatigue strength. A nominal stress of 70 MPa and a hot spot stress of 75 MPa are recommended for fatigue strength of roof-U rib welds under the manufacturing process investigated here.

Fatigue performance of rib-roof weld in steel bridge decks with corner braces

Zhongqiu Fu,Bohai Ji,Yixun Wang,Jie Xu 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.1

To study the effects of corner braces on fatigue performance of the U-rib and roof weld in steel bridge decks, the fatigue experiment was carried out to compare characteristics of the crack shape with and without corner braces. The improvement of fatigue life and stress variation after setting corner braces were also analysed. Different parameters of corner brace sizes, arrangements, and detail types were considered in the FEM models to obtain stress distribution and variation at the weld. Furthermore, enhancement of the fatigue performance by corner braces was evaluated. The results demonstrated that the corner brace could improve the fatigue life of the U-rib and roof weld, which exerted even no influence on the crack shape. Moreover, stress of the roof weld was decreased and the crack position was transferred from the root weld to U-rib and corner brace weld. It was suggested no weld scallop should be drilled on the corner brace. A transverse rib with lower height which was set between U-ribs was favourable for improvement of fatigue performance.

Behaviour of lightweight aggregate concrete-filled steel tube under horizontal cyclic load

Zhongqiu Fu,Bohai Ji,Dongyang Wu,Zhenpeng Yu 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.32 No.6

A horizontal cyclic test was carried out to study the seismic performance of lightweight aggregate concrete filled steel tube (LACFST). The constitutive and hysteretic model of core lightweight aggregate concrete (LAC) was proposed for finite element simulation. The stress and strain changes of the steel tube and concrete filled inside were measured in the experiment, and the failure mode, hysteresis curve, skeleton curve, and strain curve of the test specimens were obtained. The influence of axial compression ratio, diameter-thickness ratio and material strength were analysed based on finite element model. The results show that the hysteresis curve of LACFST indicated favourable ductility, energy dissipation, and seismic performance. The LACFST failed when the concrete in the bottom first crushed and the steel tube then bulged, thus axial force imposed by prestressing was proved to be feasible. The proposed constitutive model and hysteretic model of LAC under the constraint of its steel tube was reliable. The bearing capacity and ductility of the specimen increase significantly with increasing thickness of the steel tube. The bearing capacity of the member improves while the ductility and energy dissipation performance slightly decreased with the increasing strength of the steel and concrete.

晚淸中國對繼受外國法的選擇

장중추(Zhang Zhongqiu)(張中秋) 경북대학교 아시아연구소 2014 아시아연구 Vol.- No.18

본고는 중국어 자료에 근거하여 만청 시기 외국법을 받아들인 대상국 및 그 경로와 방식의 선택에 대해 연구하였다. 주요한 선택으로 資訊、國情、政制、目標、國際環境、法律傳統 및 人力과 物力資源의 제약이 있지만, 國情. 政制와 目標가 關鍵이기 때문에 晩淸 시기 외국법을 받아들이는 대상국을 선택하는 과정은 다음과 같다. "師夷"(1842年)→"西人(法律)皆極詳明"(1898年)→"取法歐美"(1900年)→"중국과 서양의 것을 함께 취하고, 각국의 것을 참작한다"(1902年)→"동서 각국에서 법률에 정통한 박사나 변호사 초빙"(1905年), 1842年부터 1905年 전후 63年간 만청이 "師夷"에서 "變法修律"의 선택기를 거쳐 최후 일본을 선택하였는데, 그 목적은 일본을 모방하여 서방정치 법률의 핵심을 섭취하여 영사재판권을 회수 하려는 것이었다. 그 외 중일의 政敎、風俗、文字相通, 地域相近, 人才、物力 한계 등의 요소가 있었다. 만청은 받아들일 만한 대상국을 확정한 후에 계수의 경로와 방식에서 비교적 효과적인 留學、飜譯、考察 및 외국 전문가 초빙이라는 몇 가지 방식을 선택하였다. 먼저 만청 시기 대량으로 일본에 유학하였는데, 그중 법정을 전공자가 비교적 많았다. 다음으로 일본에서 법정을 전공한 인재는 만청이 근대 일본법을 이어 받는데 상당하게 지원하였는데 직접적으로 수혜를 받은 것이 변역이라고 할 수 있다. 변역과 마찬가지로 중요한 것은 조사 고찰인데, 법제에 대한 실지 고찰은 청정 오대신의 정치 고찰이 시작이라고 할 수 있으며, 실제는 모두 일본이 시작한 것을 본받아 진행한 것으로 광서 32년(1906)에 沈家木의 추천하에 董康 등이 일본에 가서 재판과 감옥 등을 고찰할 수 있었고, 선통 원년(1909)에는 헌정 고찰을 위해 李家駒 대신이 일본에 파견되어 사법제도를 고찰하였다. 고찰 이외에 다른 중요한 경로는 직접 일본 전문가를 초빙하여 중국 입법화와 법률교육에 참여시키는 것이었다. 만청 시기 외국법을 받아들이는 이러한 선택은 우리가 중외 법률 문화 교류를 살펴보는데 거울을 제공하고 있다. This article studies the selection of a target country for foreign law succession by China of late Qing Dynasty as well as the channels and approaches based on documentation in Chinese language. According to this article, the selection was mostly limited by information, national situation, political system, objectives, international environment, legal tradition and human and material resources, of which the national situation, political system and objectives serve as key factors. In this case, procedure of selection of foreign laws for succession in late Qing Dynasty was, "learning from the foreign countries"(1842) → "westerners' laws are all detailed and clear"(1898) → "introduce a law from Europe or the United States"(1900) → "adopting laws of the east and the west, consulting laws of all countries"(1902) → "hiring doctors and lawyers from eastern or western countries whom are proficient in law"(1905). So the 63 years from 1842 to 1905 was a period of selection by China of late Qing Dynasty from "learning from the west" to "political reform and amending laws". Qing government finally selected Japan as the target country for succession in order to absorb the essence of western politics and laws and to revoke Consular jurisdictions. Besides, some other factors such as politics, education, custom, written languages, geography, as well as human and material resources also promoted the choice of Qing government. After China of late Qing Dynasty had determined the target country for succession, in terms of the channels and approaches for the succession, several fairly effective methods including studying aboard, translating foreign writings, making survey trips and hiring foreign experts were adopted. First of all, among large numbers of Chinese students studying in Japan, quite a large group of them studied law and politics. Second, many talented students who studied law and politics in Japan provided a lot of intellectual support for the succession of modern Japanese law by China of late Qing Dynasty. Translation of books was one of the direct benefits. Field survey of legal systems, which was also important, started with the survey of politics by five government officials of Qing government. Actually, it was all inspired by Japan and proceeded through treating Japan as a role model. In the 32nd year of Guangxu Period (1906), recommended by ShenJiaben, Dong Kang, etc. were approved to go to Japan to make an inspection on the matters related to sentencing and prisons. In the first year of Xuantong Period (1909), Li Jiaju was also dispatched Japan to make an inspection of its judicial system. Important as field survey, directly hiring Japanese experts to participate in China's legislation and law education is another approach for succession of modern Japanese laws by China of late Qing Dynasty. Such selection by China of late Qing Dynasty for the purpose of succession of foreign laws have offered references to us for thinking about law succession and the current exchange of laws and cultures between China and foreign countries.

東병法觀察 : 東련的法律傳統與近代變革及其走向

張中秋 경북대학교 법학연구소 2006 법학논고 Vol.24 No.-

The stiffness-degradation law of base metal after fatigue cracking in steel bridge deck

Liang Fang,Zhongqiu Fu,Bohai Ji,Xincheng Li 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.2

The stiffness evaluation of cracked base metal is of great guidance to fatigue crack reinforcement. By carrying out fatigue tests and numerical simulation of typical cracking details in steel box girder, the strain-degradation law of cracked base metal was analyzed and the relationship between base metal stress and its displacement (stiffness) was explored. The feasibility of evaluating the stress of cracked base metal based on the stress field at the crack tip was verified. The results demonstrate that the stiffness of cracked base metal shows the fast-to-slow degradation trend with fatigue cracking and the base metal at 50mm or more behind the crack tip basically lose its bearing capacity. Drilling will further accelerate stiffness degradation with the increase of hole diameters. The base metal stress has a negative linear relation with its displacement (stiffness), The stress of cracked base metal is also related to stress intensity factor and its relative position (distance, included angle) to the crack tip, through which the local stiffness can be effectively evaluated. Since the stiffness is not uniformly distributed along the cracked base metal, the reinforcement patch is suggested to be designed according to the stiffness to avoid excessive reinforcement for the areas incompletely unloaded.