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Experimental and numerical investigation into the non-explosive excavation of tunnels

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第6期14卷 1885-1900页

作者： Quan zhang Zhigang tao chun Yang Shan Guo Manchao He Chongyuan zhang Huiya Niu Chao Wang Shen Wang School of Mines China University of Mining and TechnologyXuzhouJiangsu221116China State Key Laboratory of Geomechanics and Deep Underground Engineering China University of Mining and TechnologyBeijing100083China School of Resources and Safety Engineering Central South UniversityChangsha410083China Department of Mining and Materials Engineering McGill UniversityMontrealQCH3A 0E8Canada Institute of Geomechanics Chinese Academy of Geological SciencesBeijing100081China College of Environmental Science and Engineering Ocean University of ChinaQingdao266100China School of Energy Science and Engineering Henan Polytechnic UniversityJiaozuo454003China

The use of explosives is restricted on some important holidays,and the handling of unexploded charge is very ***,an innovative non-explosive technology called instantaneous expansion(IE)was developed for ***,whose components are derived from solid wastes such as coal gangue and straw conduces to realizing the reuse of ***,its cost is lower than *** guns of IE are easy to treat with *** IE tunneling method is classified into two categories,*** with a single fracture(IESF)and IE with multiple fractures(IEMF),which are used to form the tunnel crosssection directionally cross-section and to fragment the rocks inside the cross-section,*** this study,the principle of IE tunneling was elaborated ***,tunneling experiments and numerical simulations were performed on IE,conventional blasting(CB)and shaped charge blasting(SCB)in *** experimental and numerical results show that IE achieved the best performance of directional rock breaking and corresponded to the most minor excavation-induced damage zone of the surrounding ***,the tunnel cross-section created by IE was flat and *** IE with CB and SCB,the over/under-excavation area decreased by 64%and 17%,and the excavation-induced damage zone fell by 26%and 11%,*** range of the loose circle is reduced,which is conducive to improving the long-term stability of the *** research provides a safe and economical tunneling method with excellent application prospects.

关键词： Instantaneous expansion(IE) Non-explosive Tunneling Smooth tunnel cross-section Excavation-induced damage zone

Magnetic graphene nanocomposite as an efficient catalyst for hydrogenation of nitroarenes

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Chinese Chemical Letters 2013年第6期24卷 539-541页

作者： Cheng Feng Hai-Yan zhang Ning-Zhao Shang Shu-tao Gao chun Wang College of Sciences Agricultural University of Hebei

Graphene-Fe3O4 nanocomposite（G-Fe3O4） was synthesized by a chemical co-precipitation method which was used as an efficient catalyst for the reduction of nitroarenes with hydrazine *** method has been applied to a broad range of compounds with different properties and the yields were in the range of 75%-92%.The G-Fe3O4 catalyst can be readily recovered and reused 5 times without significant loss of the catalytic activity.

关键词： Nitroarenes Magnetic graphene Reduction Hydrazine hydrate

基于RHT本构模型的连续装药预裂爆破孔距优化研究

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高压物理学报 2025年第1期39卷 109-118页

作者：张伟王建国王勉陶家龙昆明理工大学国土资源工程学院云南昆明650093 云南省教育厅爆破新技术工程研究中心云南昆明650093

为解决北衙金矿在使用预裂爆破技术时整体爆破效果不佳的问题,基于RHT损伤本构模型,利用ANSYS/LS-DYNA数值模拟软件,开展了不同孔距下预裂爆破的数值模拟研究。结果表明:当预裂孔炮孔间距为120 cm时,孔间裂纹存在较为明显的分叉,且裂纹... 详细信息

为解决北衙金矿在使用预裂爆破技术时整体爆破效果不佳的问题,基于RHT损伤本构模型,利用ANSYS/LS-DYNA数值模拟软件,开展了不同孔距下预裂爆破的数值模拟研究。结果表明:当预裂孔炮孔间距为120 cm时,孔间裂纹存在较为明显的分叉,且裂纹扩展范围较大;当炮孔间距为130 cm时,裂纹向四周扩展的范围减小,且炮孔周围岩石的损伤程度明显降低;当炮孔间距增加至140 cm时,相邻预裂孔连线上的裂纹仅在局部连通,无法实现孔间贯穿。上述结果说明,130 cm的炮孔间距在降低预裂爆破自身对岩体的扰动与实现有效爆破成缝之间达到了平衡。基于数值模拟试验结果开展了现场试验,爆破效果良好。研究结果可为矿山的预裂爆破设计和施工提供参考。

关键词：预裂爆破连续装药孔距优化 RHT本构模型

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EXPERIMENT STUDY ON SEDIMENT INCIPIENCE IN BACKWARD-FACING STEP FLOW

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Journal of Hydrodynamics 2007年第2期19卷 173-179页

作者： LIU chun-rong Huhe Aode tao Long-bin Department of-Engineering Mechanics Hunan University Changsha 410082 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China School of Engineering Griffith University PMB50 GCMC Qld9726 Australia

Flow over a backward-facing step was studied to investigate the effect of large-scale vortex structures on sediment incipience. The transient flow velocity field at the downstream of the backward-facing step was obtained using the technique of Particle Tracking Velocimetry （PTV）. The optical amplification technique was employed to measure the instantaneous flow velocities near the bed and the instantaneous bed shear stress was given. The experimental observations revealed a new insight into the oscillation of the large-scale structure and the three-dimensional characteristics of the flow. In particular, very high turbulence intensity, instantaneous horizontal velocity near the bed and the bed shear stress near the reattachment point were observed. The sediment incipient probability obtained from the sequent images of sediment particles near the bed indicates that the critical instantaneous shear stress of the sediment incipience is independent of flow conditions.

关键词： backward-facing step flow coherent structure,sediment incipience Particle Tracking Velocimetry (PTV)

Photolysis of chlortetracycline in aqueous solution:Kinetics,toxicity and products

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Journal of Environmental Sciences 2012年第2期24卷 254-260页

作者： Yong Chen Hua Li Zongping Wang tao tao Dongbin Wei chun Hu State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China School of Environmental Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China.

The aqueous photodegradation of the widely used antibiotic chlortetracycline（CTC） was investigated under simulated *** quantum yield of photodegradation increased from 3.3 × 10-4 to 8.5 × 10-3 within the pH range of 6.0 to *** presence of Ca2＋,Fe3＋,and NO3-enhanced the photodegradation of CTC,whereas Mg2＋,Mn2＋,and Zn2＋ inhibited the degradation with the order Mn2＋ Zn2＋ Mg2＋ at pH *** monovalent cations（Na＋ and K＋） had negligible effect on the photolysis of *** acid（FA） decreased the photodegradation of CTC due to light screening *** peroxide（H2O2） was formed concurrently with direct photodegradation of *** generation rate of H2O2 increased from 0.027 to 0.086 μmol/（***） when the pH ranged from 6.0 to *** CTC solution was about three-fold more toxic to the Photobacterium phosphoreum bacteria after irradiation,suggesting that the photoproducts and H2O2 formed in the CTC solution exhibited high risk on the *** LC-ESI（＋）-MS,the photoproducts of CTC were *** direct photodegradation of CTC was involved in hydroxylation and N-demethyl/dedismethyl *** main photoproducts included the iso-CTC analog containing hydroxyl groups（m/z 511.4 and 495.4）,and the N-demethyl/dedismethyl products of the photoproduct m/z 495.4（m/z 481.3 and 467.4）.In addition,the photochemical dechlorination of CTC led to tetracycline（m/z 445.5）.

关键词： chlortetracycline direct photodegradation phototoxicity photoproducts

Effect of mesopores on solidification of sirolimus self-microemulsifying drug delivery system

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Chinese Chemical Letters 2018年第12期29卷 1849-1852页

作者： chun tao Yue Yu Zhenzhen Chen Minxin zhang Linlin Liu Zhihong Liu Jialiang zhang Qian zhang Hongtao Song Department of Pharmacy Fuzong Clinical Medical College of Fujian Medical University (Fuzhou General Hospital) College of Pharmacy Fujian Medical University

To investigate the influence of mesopores towards the solidification of self-microemulsifying drug delivery system(SMEDDS), mesoporous silica nanospheres(MSNs) and Santa Barbara Amorphous-15(SBA-15) were compared. The MSNs had hydrodynamic size of 195.35 ± 5.82 nm, and pore diameter of 2.70 nm. The SBA-15 had hydrodynamic size of 2312.19 ± 106.93 nm, and pore diameter of 10.91 nm. The MSNs and SBA-15 showed similar loading efficiency of SMEDDS containing sirolimus(SRL). However,MSNs had higher drug dissolution and in vivo absorption, with relative bioavailability of 174.62%. Thus,the length of mesopores played a more important role in solidification of SMEDDS as compared with the pore diameter. This study suggests that the SMEDDS-MSNs can be a potential candidate for oral administration of hydrophobic drugs.

关键词： Mesopores Mesoporous silica nanospheres SBA-15 Self-microemulsifying drug delivery system Sirolimus Bioavailability

Numerical simulation research on surface radiation heat calculation of spacecraft in orbit whole course

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航空动力学报 2010年第10期25卷 2229-2237页

作者： SUN Bing zhang tao School of Astronautics Beijing University of Aeronautics and Astronautics Beijing 100191 China

The surface radiation heat simulation program based on Microsoft VC++ 6.0 for spacecraft in whole orbit course was *** to complexity of spacecraft structure,the spacecraft structures were decomposed to relatively regular *** generation of calculation grid was conducted by using structured grid and unstructured *** mainly solved automatic grid generation for arbitrary surface and data transmission between arbitrary shape interfaces,and the geometry structure,physical process,calculation accuracy and efficiency were *** factors and radiation transfer coefficients were calculated by combining finite element method and ray uniform *** to the position of surface cells,external heat flux was calculated with integral method for non-shaded surface and with ray uniform distribution method for shaded *** the spacecraft surface was wrapped with multilayer insulation material,the temperature field of multilayer insulation material was calculated with nodal network method and finite volume *** temperature of other parts without wrap was calculated with finite element *** temperature of unconnected regions available with radiation heat transfer relations was analyzed,and the calculation formulae were *** experiment shows that the simulation program is correct and effective.

关键词： spacecraft radiation heat calculation whole course numerical simulation

A vision-based navigation approach with multiple radial shape marks for indoor aircraft locating

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Chinese Journal of Aeronautics 2014年第1期27卷 76-84页

作者： Zhou Haoyin zhang tao Department of Automation School of Information Science and TechnologyTsinghua University National Key Laboratory of Integrated Flight Vehicle Control Technology Xi'an Flight Automatic Control Research Institute

Since GPS signals are unavailable for indoor navigation, current research mainly focuses on vision-based locating with a single mark. An obvious disadvantage with this approach is that locating will fail when the mark cannot be seen. The use of multiple marks can solve this problem. However, the extra process to design and identify different marks will significantly increase system complexity. In this paper, a novel vision-based locating method is proposed by using marks with feature points arranged in a radial shape. The feature points of the marks consist of inner points and outer points. The positions of the inner points are the same in all marks, while the positions of the outer points are different in different marks. Unlike traditional camera locating methods （the PnP methods）, the proposed method can calculate the camera location and the positions of the outer points simultaneously. Then the calculation results of the positions of the outer points are used to identify the mark. This method can make navigation with multiple marks more efficient. Simulations and real world experiments are carried out, and their results show that the proposed method is fast, accurate and robust to noise.

关键词： Flexible mark Indoor aircraft Multiple marks Navigation Vision-based locating

Capacitated stochastic coloured Petri net-based approach for computing two-terminal reliability of multi-state network

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Journal of Systems Engineering and Electronics 2012年第2期23卷 304-313页

作者： tao zhang Bo Guo College of Information Systems and Management National University of Defense TechnologyChangsha 410073R R.China

Classical network reliability problems assume both net- works and components have only binary states, fully working or fully failed states. But many actual networks are multi-state, such as communication networks and transportation networks. The nodes and arcs in the networks may be in intermediate states which are not fully working either fully failed. A simulation ap- proach for computing the two-terminal reliability of a multi-state network is described. Two-terminal reliability is defined as the probability that d units of demand can be supplied from the source to sink nodes under the time threshold T. The capacities of arcs may be in a stochastic state following any discrete or continuous distribution. The transmission time of each arc is also not a fixed number but stochastic according to its current capacity and de- mand. To solve this problem, a capacitated stochastic coloured Petri net is proposed for modelling the system behaviour. Places and transitions respectively stand for the nodes and arcs of a net- work. Capacitated transition and self-modified token colour with route information are defined to describe the multi-state network. By the simulation, the two-terminal reliability and node importance can be estimated and the optimal route whose reliability is highest can also be given. Finally, two examples of different kinds of multi- state networks are given.

关键词： two-terminal reliability multi-state network Petri net (PN) simulation node importance.