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Test analysis on prestressed concrete composite beams with steel boxes subjected to torsion and combined flexure and torsion

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Science China(Technological Sciences) 2012年第12期55卷 3302-3310页

作者： hu ShaoWei CHEN liang Nanjing Hydraulic Research Institute Nanjing 210029China Research Center on New Materials in Hydraulic Structures Ministry of Water ResourcesNanjing 210029China

While modem prestressed techniques have improved the torsion properties of high-strength concrete （HSC） composite beams with prestressed steel （PS） boxes, no research has been reported in either the national or international literature on the an- ti-torque and composite torque properties of this type of beam. With the aim of understanding the torque properties of these beams, this paper presents results of ten comprehensive tests; three of these were based on stirrup spacings and prestressing levels as the main parameters, while the other seven were based on torsional rates. The torsion tests were conducted on the re- sults which established several key parameters, including curves of constant torsion, strain curves of steel torsion, strain distri- bution of steel beams and concrete, curves of bending-moment and mid-span deflection, as well as cross strain *** prestressing impact-factor method was adopted to deduce semiempirical equations for cracking torque in such composite beams. Furthermore, this involves the use of the equation of ultimate torque based on tress-model-theory of the distortion an- gle, the calculated results show good agreement with the measured values. In summary, this paper offers theoretical analysis for future applications of HSC composite beams with PS boxes, and provides both validation of the methods employed and a reference point for on-going research on composite beams and related anti-torque studies.

关键词： high-strength concrete composite beams prestressed steel boxes torsion property cracking torque ultimate torque combined torsion torsion-bending correlation equation

Preparation of active coke combining coal with biomass and its denitrification performance

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Journal of Iron and Steel Research International 2021年第10期28卷 1203-1211页

作者： Xiao-hu Zhou sheng-fu Zhang Yu-yang Wei Farooq Sher Yang Li Wen-zhou Yu liang-ying Wen College of Materials Science and Engineering Chongqing UniversityChongqing400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and Advanced Materials Chongqing UniversityChongqing400044China School of Mechanical Aerospace and Automotive EngineeringFaculty of EngineeringEnvironment and ComputingCoventry UniversityCoventryCV15FBUK

To improve the selective catalytic reduction of NO with NH3 over active coke(AC),coal–biomass ACs were prepared from the mixture of poplar and 1/3 coking coal for increasing the active *** resultant ACs were characterized by N2 adsorption and X-ray photoelectron ***,the denitrification performance was tested at laboratory *** addition,density functional theory was used to analyze active sites on the surface of *** result revealed that,with an increase in poplar content,the decrease in micropores volume appeared in the reduction of denitrification ***,C−O group including hydroxyl and ether increased with the increase in poplar content,which was found to be most likely responsible for the promoted catalytic activity of AC toward NO reduction mainly because of enhancing NH3 *** comprehensive effect of two factors made the denitrification ability of AC increased first and then decreased.

关键词： Active coke Denitrification Pore structure Functional group Density functional theory

The Number of Triangles in Random Intersection Graphs

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Communications in Mathematics and Statistics 2023年第4期11卷 695-725页

作者： liang Dong Zhishui hu International Institute of Finance School of ManagementUniversity of Science and Technology of ChinaHefeiPeople’s Republic of China

Let Tn be the number of triangles in the random intersection graph G(n,m,p).When the mean of Tn is bounded,we obtain an upper bound on the total variation distance between Tn and a Poisson *** the mean of Tn tends to infinity,the Stein–Tikhomirov method is used to bound the error for the normal approximation of Tn with respect to the Kolmogorov metric.

关键词： Random intersection graph Stein’s method Poisson approximation Normal approximation

An Efficient Boron Source Activation Strategy for the Low‑Temperature Synthesis of Boron Nitride Nanotubes

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Nano-Micro Letters 2025年第1期17卷 548-558页

作者： Ying Wang Kai Zhang Liping Ding Liyun Wu Songfeng E Qian He Nanyang Wang hui Zuo Zhengyang Zhou Feng Ding Yue hu Jin Zhang Yagang Yao National Laboratory of Solid State Microstructures College of Engineering and Applied SciencesJiangsu Key Laboratory of Artificial Functional Materialsand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093People’s Republic of China School of Electronic Information and Artificial Intelligence Shaanxi University of Science&TechnologyXian 710000People’s Republic of China College of Bioresources Chemical and Materials Engineering Shaanxi University of Science&TechnologyXian 710000People’s Republic of China Key Laboratory of Carbon Materials of Zhejiang Province College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325000People’s Republic of China Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518000People’s Republic of China College of Chemical and Molecular Engineering Peking UniversityBeijing 100871People’s Republic of China

Lowering the synthesis temperature of boron nitride nanotubes(BNNTs)is crucial for their *** primary reason for adopting a high temperature is to enable the effective activation of highmelting-point solid *** this study,we developed a novel approach for efficiently activating boron by introducing alkali metal compounds into the conventional MgO–B *** approach can be adopted to form various low-melting-point AM–Mg–B–O growth *** growth systems have improved catalytic capability and reactivity even under low-temperature conditions,facilitating the synthesis of BNNTs at temperatures as low as 850℃.In addition,molecular dynamics simulations based on density functional theory theoretically demonstrate that the systems maintain a liquid state at low temperatures and interact with N atoms to form BN *** findings offer novel insights into the design of boron activation and are expected to facilitate research on the low-temperature synthesis of BNNTs.

关键词： Boron nitride nanotubes Low-temperature Boron activation Density functional theory

Degenerate cascade fluorescence: Optical spectral-line narrowing via a single microwave cavity

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Chinese Physics B 2021年第6期30卷 346-358页

作者： liang hu Xiang-Ming hu Qing-Ping hu College of Physical Science and Technology Central China Normal UniversityWuhan 430079China

For a three-level atom, two nondegenerate(even microwave and optical) electric dipole transitions are usually allowed;for either of these, the fluorescence spectra are well-described in terms of spontaneous transitions from a triplet of dressed sublevels to an adjacent lower-lying triplet. When the three dressed sublevels are equally spaced from each other, a remarkable feature known as degenerate cascade fluorescence takes place, which displays a five-peaked structure. We show that a single cavity can make all the spectral lines extremely narrow, whether they arise from cavity-coupled or cavity-free transitions. This effect is based on intrinsic cascade lasing feedback and makes it possible to use a single microwave cavity(even a bad cavity) to narrow the spectral lines in the optical frequency regime.

关键词： resonance fluorescence narrow spectral lines microwave cavity

Structure of V_2O_5-P_2O_5-Sb_2O_3-Bi_2O_3 glass

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International Journal of Minerals,Metallurgy and Materials 2012年第7期19卷 628-635页

作者： Hong-yan Li Zhi-liang Zhu Feng-li Yang Wei-dong Zhuang Yun-sheng hu Xiao-fan Wen National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous Metals and Grirem Advanced Materials Co. Ltd. Beijing 100088 China BOE Technology group Co. Ltd. Beijing 100015 China Beijing Asahi Glass Electronics Co. Ltd. Beijing 100015 China

The structure ofV2O5-P2O5-Sb2O3-Bi2O3glass and its state of crystallization were studied by means of infrared spectroscopy and X-ray diffraction analysis. The results indicate that, in this glass, V and P exist mainly in the form of a single-stranded linear （VO3）n and an isolated （PO4） tetrahedral with no double bond. Partial V and P are connected through O, forming an amorphous structure of layered vana- dium phosphate. Trivalent Sb3＋ and Bi3＋ open the V=O bond and appear in interlayers, so a weak three-dimensional structure is connected successfully. Along with the substitution of Sb203 for partial V205 or that of P205 for partial V205, the network structure of the glass is rein- forced, and the crystallization is reduced.

关键词： glass structure sealing vanadium pentoxide phosphorus pentoxide antimonous oxide bismuth trioxide

Tailor-made high elasticity and low-hysteresis hydrogels based on asymmetric H-bonding crosslinking for wearable applications

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Science China Chemistry 2025年

作者： Xiaofang Shi Nan Shi Miaomiao Dang Chengyu Ji Yingjie Li Peiyi Wu Zhiguo hu Collaborative Innovation Centre of Henan Province for Green Manufacturing of Fine Chemicals Henan Engineering Laboratory of Chemical Pharmaceutical and Biomedical Materials School of Chemistry and Chemical Engineering Henan Normal University State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Chemistry Chemical Engineering and Biotechnology & Center for Advanced Low-dimension Materials Donghua University

The conventional method of fabricating hydrogels constantly confronts the conflict between elasticity and toughness, limiting their repetitive application. Achieving the desired elasticity through a simple and low-cost approach is a significant challenge for hydrogels, particularly through rational molecular design. Here, low-hysteresis and high-toughness hydrogels are developed from the design of a new feature monomer, N-acryloylethylsemicarbazide (NACE). Based on a concept of “asymmetric Hbonding design”, the unique double and triple H-bonding of NACE can result in a novel asymmetric crosslinking polymer with alternating strong and weak H-bonding regions. The NACE is copolymerized with acrylamide (AM) to regulate the mechanical properties of hydrogel via H-bonding density. The P(NACE-AM) ionic hydrogels are obtained simply and rapidly via one-step photopolymerization without a chemical cross-linking agent. The P(NACE-AM) hydrogels combine superb mechanical elasticity and toughness, and excellent ionic conductivity, showing great potential as durable ionic conductive devices for wearable utilization.

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Mechanistic insights into sequestration of U(VI) toward magnetic biochar: Batch, XPS and EXAFS techniques

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Journal of Environmental Sciences 2018年第8期30卷 217-225页

作者： Qingyuan hu Yuling Zhu Baowei hu Songhua Lu Guodong sheng College of Life Science College of Chemistry and Chemical Engineering Shaoxing University Institute of Plasma Physics Chinese Academy of Science

The magnetic iron oxide（Fe3O4） nanoparticles stabilized on the biochar were synthesized by fast pyrolysis of Fe（II）-loaded hydrophyte biomass under N2 conditions. The batch experiments showed that magnetic biochar presented a large removal capacity（54.35 mg/g）at pH 3.0 and 293 K. The reductive co-precipitation of U（VI） to U（IV） by magnetic biochar was demonstrated according to X-ray diffraction, X-ray photoelectron spectroscopy and X-ray absorption near edge structure analysis. According to extended X-ray absorption fine structure analysis, the occurrence of U-Fe and U-U shells indicated that high effective removal of uranium was primarily inner-sphere coordination and then reductive co-precipitation at low pH. These observations provided the further understanding of uranium removal by magnetic materials in environmental remediation.

关键词： Magnetic biochar Uranium X-ray absorption spectroscopy Sequestration

Integrating potential distribution of dominant vegetation and land use into ecological restoration in the Yellow River Basin,China

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Journal of Mountain Science 2022年第10期19卷 2886-2904页

作者： JIAN sheng-qi Zhu Tian-sheng hu Cai-hong College of Water Resources and Environment Zhengzhou UniversityZhengzhou 450001China

Due to the influence of human activities such as cultivation and urban construction,the ecosystem of the Yellow River Basin(YRB)is subjected to increased vulnerability and even potential risk of *** restoration has led to an increase in vegetation,but excessive afforestation conversely results in low survival rate of trees,water shortages,and biodiversity *** is of great significance for achieving sustainable development of forests to reasonable revegetation in the *** present,the potential distribution pattern of dominant species and their mixed forms in the basin has not been effectively *** study simulated the potential distribution of dominant vegetation in the YRB based on Maximum Entropy(Max Ent)and Genetic Algorithm for Rule-Set Prediction(GARP)and explored the impact of human interference on it by employing land use as the environmental filter to distinguish the regions of human *** further predicted the potential distribution of typically mixed forests and discussed their human *** main results are as follows:(1)Except for Caragana korshinskii,all models had good above performance(0.7human activities caused great damage to the core growth regions of these vegetation.(3)Mean temperature of c

关键词： Yellow River Potential distribution Land use Mixed forests Vegetation restoration