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Effect of Progressive Substitution of Cement and Lime by Powdered Shells Used as a Curing Agent for Dredged Soil in a Port Area

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 88-102页

作者： sun Yang WANG Faxin SU Yaying LI Yiwei HE Feng College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210098China huai'an Research Institute Hohai UniversityHuai'an 223025China Jiangsu Fangyang Industrial Investment Corp.Ltd. Lianyungang 210098China

This study aimed to address the challenges of solid waste utilization,cost reduction,and carbon reduction in the treatment of deep-dredged soil at Xuwei Port in Lianyungang city of *** research in this area was ***,a curing agent made from powdered shells was used to solidify the dredged soil in *** employed laboratory orthogonal tests to investigate the physical and mechanical properties of the powdered shell-based curing *** was collected by conducting experiments to assess the role of powdered shells in the curing process and to determine the optimal ratios of powdered shells to solidified soil for different *** development of strength in solidified soil was studied in both seawater and pure water *** study revealed that the strength of the solidified soil was influenced by the substitution rate of powdered shells and their interaction with *** cement content had a positive effect on *** high-strength solidified soil,the recommended ratio of wet soil:cement:lime:powdered shells were 100:16:4:4,while for low-strength solidified soil,the recommended ratio was 100:5.4:2.4:***,under appropriate conditions,improved short-term strength by promoting the formation of expansive ettringite minerals that contributed to cementation and *** findings suggest that the combination of cement and powdered shells is synergistic,positively affecting the strength of solidified *** recommended ratios provide practical guidance for achieving desired strength levels while considering factors such as cost and carbon *** role of seawater in enhancing short-term strength through crystal formation is noteworthy and can be advantageous for certain *** conclusion,this research demonstrates the potential of using a powdered shell-based curing agent for solidifying dredged soil in an environmentally friendly and cost-effective *** recommended ratios for different str

关键词： carbon reduction and solidification dredged soil abandoned shells orthogonal test chemical additives(lime and cement) unconfined compressive strength(UCS)

A theoretical study of hydrothermal stability of P-modified ZSM-5 zeolites

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Science China Chemistry 2009年第3期52卷 282-287页

作者： YANG Jing sun huai School of Chemistry and Chemical Technology Shanghai Jiao Tong UniversityShanghai 200240China

Density functional theory was employed to study the hydrothermal stability of P-modified ZSM-5 zeolites using cluster models. The calculations of hydrolysis energies indicated that the introduction of phos-phorus increases the hydrothermal stability of ZSM-5 zeolites. The initial paths of dealumination were studied with explicit water molecules. It was found that the framework Al-O coordination bond can be replaced by coodination bonds between water molecules and the aluminium. One to three water molecules can form coordination bonds with framework Al and release energies. The P-modification restrain the dealumination. The calculated 27Al NMR chemical shifts for the obtained structures are consistent with the experimental measurements.

关键词： density functional theory P-ZSM-5 zeolite dealumination NMR

An image encryption algorithm based on improved baker transformation and chaotic S-box

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Chinese Physics B 2021年第6期30卷 216-225页

作者： Xing-Yuan Wang huai-huai sun Hao Gao School of Information Science and Technology Dalian Maritime UniversityDalian 116026China

The algorithm is an image encryption algorithm based on the improved baker transformation and chaotic substitution box(S-box). It mainly uses the initial values and parameters of a one-dimensional logistic chaotic system as an encryption key. Specifically, in the image scrambling stage, the algorithm primarily uses an improved baker transform method to process the image. In the image diffusion stage, the algorithm first uses the chaotic S-box method to process the encryption key. Secondly, an exclusive OR(XOR) operation is performed on the image and the encryption key to initially diffuse the image. Finally, the image is again diffused using the method of ortho XOR. Simulation analysis shows that the algorithm can achieve good encryption effect, simple and easy implementation, and good security. In the digital image communication transmission, it has good practical value.

关键词： image encryption improved baker transformation chaotic S-box chaotic sequence

Dynamics modeling and control of a transport aircraft for ultra-low altitude airdrop

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Chinese Journal of Aeronautics 2015年第2期28卷 478-487页

作者： Liu ri sun Xiuxia Dong Wenhan Aeronautics and Astronautics Engineering College Air Force Engineering University

The nonlinear aircraft model with heavy cargo moving inside is derived by using the sep- aration body method, which can describe the influence of the moving cargo on the aircraft attitude and altitude accurately. Furthermore, the nonlinear system is decoupled and linearized through the input^utput feedback linearization method. On this basis, an iterative quasi-sliding mode （SM） flight controller for speed and pitch angle control is proposed. At the first-level SM, a global dynamic switching function is introduced thus eliminating the reaching phase of the sliding motion. At the second-level SM, a nonlinear function with the property of ＂smaUer errors correspond to bigger gains and bigger errors correspond to saturated gains＂ is designed to form an integral sliding manifold, and the overcompensation of the integral term to big errors is weakened. Lyapunov- based analysis shows that the controller with strong robustness can reject both constant and time-varying model uncertainties. The performance of the proposed control strategy is verified in a maximum load airdrop mission.

关键词： Dynamics modeling Feedback liaearization Flight control Nonlinear system Sliding mode control Uncertainty

Numerical investigation on the geodynamical mechanism of the first major shock of 2006 Pingtung M_w7.0 earthquake

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Science China Earth Sciences 2011年第5期54卷 631-639页

作者： sun YuJun ZHANG huai SHI YaoLin Laboratory of Computational Geodynamics Graduate University of Chinese Academy of Sciences Beijing 100049 China

A strong Mw7.0 earthquake struck Pingtung offshore of Talwan on December 26, 2006. It consisted of two major events with an 8-minute interval. The first major shock occurred at 12：26 UTC. Focal mechanism results from Harvard, USGS, and BATS all indicated that the first major shock was a normal fault earthquake and the second one was dominated by strike-slip offsets. The location of the epicenter varied greatly in depth in different analyses. The latest results showed that the focal depth of the first shock was most probably around 40-44 km, placing the epicenter in the lithospheric mantle. However, this is not a location where earthquakes usually occur. To explore the geodynamical mechanism of this event, we carded out 2D finite element method （FEM） numerical experiments. Our primary results indicate that the geodynamical background, as well as the formation of Pingtung earthquake, is a consequence of the collision between Luzon arc and Chinese continental margin. Although Taiwan Island is in the shadow of NW-SE trending compressive collision zone, the existence of ductile lower crust leads to the decoupling between upper crust and lithospheric mantle. As lithospheric mantle subducts to the depth of around 250 km, the upper part of the bending subduction slab puts itself in an extensional state. The extensional stress from bending induced the occurrence of this normal fault earthquake at the critical point.

关键词： Pingtung earthquake geodynamical mechanism FEM simulation hierarchical rheology geodynamics

Prediction of adsorption of small molecules in porous materials based on ab initio force field method

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Science China Chemistry 2008年第8期51卷 760-767页

作者： LIU LianChi FU Jia sun huai School of Chemistry and Chemical Technology Shanghai Jiao Tong University Shanghai 200240 China

Computational prediction of adsorption of small molecules in porous materials has great impact on the basic and applied research in chemical engineering and material sciences. In this work,we report an approach based on grand canonical ensemble Monte Carlo(GCMC) simulations and ab initio force fields. We calculated the adsorption curves of ammonia in ZSM-5 zeolite and hydrogen in MOF-5(a metal-organic-framework material). The predictions agree well with experimental data. Because the predictions are based on the first principle force fields,this approach can be used for the adsorption prediction of new molecules or materials without experimental data as guidance.

关键词： Porous materials adsorption ab initio force field Grand Canonical ensemble Monte Carlo

Dynamics analysis for flux of carbon dioxide across seasurface

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Acta Oceanologica Sinica 1996年第4期15卷 447-455页

作者： Zhang huai and sun Fu Ocean University of Qingdao Qingdao 266003 China

The CO2 exchange between atmosphere and seawater has ho discussed. The physical process of exchange at seasurface is related closely with the atmospheric forcing. The result of a dynamics analysis of .the CO2 flux across the seasurface, and a computed example over the shelf area of the East China Sea are reported. The analysis and calculation show that the CO2 vertical flux at seawater is mainly dependent on the CO2 concentration difference between seawater and atmosphere. Its exchange velocity is affected by the friction velocity, solubility and resistivity. The agreement between this exchange velocity and recent wind tunnel experimental results is good with wind speed over the range4～ 10m/s. This flux can increase very fast with the increase of wind speed, but very small with the increase oftemperature. During the three cruise expeditions in October 1993, and April and October 1994, the CO2 vertical flux at seasurface was directed downward over the shelf area of the East China Sea. Because the CO2 Partial pressure difference between seawater and atmosphere was negative value, the flux value was - 45. 5μg/(m2.h) in average.

关键词： Friction velocity diffusivity solubility resistivity

Finite-time adaptive sliding mode control for heavyweight airdrop operations

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Journal of Systems Engineering and Electronics 2017年第2期28卷 338-346页

作者： ri Liu Xiuxia sun Wenhan Dong Dong Wang Aeronautics and Astronautics Engineering College Air Force Engineering University Xi’an 710038 China

This paper investigates the problem of designing a fast convergent sliding mode flight controller of a transport aircraft for heavyweight airdrop operations in the presence of bounded uncertainties without the prior knowledge of the bounds. On the basis of feedback linearization of the aircraft-cargo motion system, a novel integral sliding mode flight control law with gains adaptation is proposed. It contains a nominal control law used to achieve finite-time stabilization performance and a compensated control law used to reject the uncertainties. The switching gains of the compensated control law are tuned using adaptation algorithms, and the knowledge of the bounds of the uncertainties is not required to be known in advance. Meanwhile, the severe chattering of the sliding mode control that caused by high switching gains is effectively reduced. The controller and its performance are evaluated on a transport aircraft performing a maximum load airdrop task in a number of simulation scenarios.

关键词： flight control nonlinear system sliding mode control adaptive control finite-time stability

Numerical simulation of tectonic stress and strain rate fields in the northeastern margin of the Tibetan Plateau in association with major fault zones

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Science China Earth Sciences 2023年第10期66卷 2353-2367页

作者： Shuhong ZHOU huai ZHANG Yunqiang sun Caibo HU Yaolin SHI Key Laboratory of Computational Geodynamics University of Chinese Academy of SciencesBeijing100049China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai519080China Beijing Yanshan Earth Critical Zone National Research Station University of Chinese Academy of SciencesBeijing101408China College of Transportation and Civil Engineering Fujian Agriculture and Forestry UniversityFuzhou350002China

A series of large strike-slip and thrust faults have developed in the northeastern margin of the Tibetan Plateau since the Late Cenozoic,with strong and active tectonic activity and frequent occurrences of large *** of regional tectonic stress distribution,strain fields,and seismic hazards has not been well *** study introduces a three-dimensional viscoelastic finite element numerical model to calculate crustal stress and strain rate fields under current tectonic *** preliminary results show that the direction of the horizontal principal compressive stress rate and compressive horizontal principal strain rate in the northeastern margin of the Tibetan Plateau rotate clockwise as a whole,and this rotation is more significant in the southeast direction because of the block of the Alxa and the Ordos *** NE-SW horizontal principal compressive stress rate and SE horizontal tensile stress rate dominate the entire study *** maximum value of the horizontal principal compressive strain rate at a depth of 0 km in the model is approximately 4×10^(-8)yr^(-1)near the East Kunlun fault and is smaller in the stable Alxa and Ordos blocks at approximately 1×10^(-8)yr^(-1).The calculated regional stress state is in good agreement with the actual focal mechanism solution,indicating that strike-slip and thrust stress fields dominate the northeastern margin of the Tibetan *** Altyn Tagh,East Kunlun,and Haiyuan faults demonstrate that the maximum shear strain rate gradually decreases eastward,and the decrease in the maximum shear strain rate value is absorbed by orogenic uplift and crustal shortening at its *** western section of the Altyn Tagh fault,west-to-middle sections of the East Kunlun fault,and west-to-middle sections of the Haiyuan fault will have high seismic hazards in the future.

关键词： Northeastern margin of the Tibetan Plateau Finite element model Stress and strain fields Seismic hazard