The crystal structure of one novel Mn（II） complex, [Mn（pmta）_3]_2[Mn（H_2O）_6]·4H_2O（1）, is reported（Hpmta = 5-methyl-1-phenyl-1H-1,2,3-triazole-4-carboxylic acid）. In the title compound, the asymmetric ...The crystal structure of one novel Mn（II） complex, [Mn（pmta）_3]_2[Mn（H_2O）_6]·4H_2O（1）, is reported（Hpmta = 5-methyl-1-phenyl-1H-1,2,3-triazole-4-carboxylic acid）. In the title compound, the asymmetric unit consists of a [Mn（pmta_）3]ˉ anion, half [Mn（H_2O）_6]^（2＋） counter cation and two lattice H_2O molecules, and the intra- and intermolecular hydrogen bonds connect the complex into a supramolecular structure. The liquid-state fluorescence spectra of complex 1 have been determined. Hirshfeld surface analysis was also studied. The main intermolecular interactions in the complex are O···H and H···H contacts.展开更多
The response displacement method(RDM)is recommended for the seismic analysis of underground structures in the transverse direction for many codes,including bases for design of structures-seismic actions for designing ...The response displacement method(RDM)is recommended for the seismic analysis of underground structures in the transverse direction for many codes,including bases for design of structures-seismic actions for designing geotechnical works(ISO 23469)and code for seismic design of urban rail transit structures(GB 50909-2014).However,there are some obvious limitations in the application of RDM.Springs and the shear stress of the soil could be approximately evaluated for the structures having a simple cross section,such as rectangular and circular structures.It is necessary to propose simplified seismic analysis methods for structures with complex cross sections.This paper refers to the idea of RDM and proposes three generalized response displacement methods(GRDM).In GRDM1,a part of the soil surrounding a structure is selected to generate a generalized underground structure with a rectangular cross section,and the same analysis model as RDM is applied to analyze the responses of the structure.In GRDM2,a hollow soil model without a generalized structure is used to compute the equivalent load caused by the relative displacement of the soil,and the soil-structure interaction model is applied to calculate the responses of the structure.In GRDM3,a continuous soil model is applied to compute the equivalent load caused by the relative displacement and shear stress of the soil,and the soil-structure interaction model is applied to analyze the responses of the structure,which is the same as the model used in GRDM2.The time-history analysis method(THAM)is used to evaluate the accuracy of the proposed simplified methods.Results show that the error of GRDM1 is about 20%,while the error is only 5%for GRDM2 and GRDM3.Among the three proposed methods,GRDM3 has obvious advantages regarding calculation efficiency and accuracy.Therefore,it is recommended to use GRDM3 for the seismic response analysis of underground structures that have conventional simple or complex cross sections.展开更多
Electrochemical micromachining （EMM） technology for fabricating micro structures is presented in this article. By applying ultra short pulses, dissolution of a workpiece can be restricted to the region very close to...Electrochemical micromachining （EMM） technology for fabricating micro structures is presented in this article. By applying ultra short pulses, dissolution of a workpiece can be restricted to the region very close to the electrode. First, an EMM system for meeting the requirements of the EMM process is established. Second, sets of experiments is carried out to investigate the influence of some of the predominant electrochemical process parameters such as electrical parameters, feed rate, electrode geometry features and electrolyte composition on machining quality, especially the influences of pulse on time on shape precision and working end shape of electrode on machined surface quality. Finally, after the preliminary experiments, a complex microstructure with good shape precision and surface quality is successfully obtained.展开更多
The northern Sichuan Basin,spreading in the northern section of the Longmenshan Fault Fold Belt,is characterized by dramatic fluctuations in the surface landforms,development of abdominal faults,and low-quality seismi...The northern Sichuan Basin,spreading in the northern section of the Longmenshan Fault Fold Belt,is characterized by dramatic fluctuations in the surface landforms,development of abdominal faults,and low-quality seismic data,resulting in difficulties in clarifying relevant structures.The key target formation,the Mid-Permian Qixia Fm,is deeply buried with thin reservoirs and high heterogeneity,which brings great challenges to seismic prediction.Under such circumstances,researches have been conducted jointly in terms of seismic data acquisition,processing and interpretation,and finally some relevant seismic survey technologies were developed suitable for surface/underground complex structures.Through surface structural surveys,dynamic deep-well lithologic identification,single-point detector deployment and process optimization,acquisition parameters can be excited.In addition,by using an observation systemwith high-coverage,wide-azimuth and huge-displacement,quality of acquired seismic data can be enhanced dramatically.Seismic imaging technologies for complex structures have been developed to enhance the quality of images for deep formations.These technologies are dominated by microscopic logging-constrained tomography static correction,high-resolution processing with fidelity and amplitude preservation and all-around PSDM in an angular domain.By using high-resolution gravity,magnetic and electric data,details related to geological structures and faults can be identified.In combination with fine seismic data interpretation,structural details and fault features can be verified effectively.Based on forwardmodeling and fine seismic calibration of reservoirs in individualwells,suitable attributes can be identified for predictions related to the distribution of reservoirs.By using all these auxiliary technologies,a large-scale structuralelithologic composite trap with a total area of 1223 km^(2) has been discovered in the NW Sichuan Basin.The Shuangyushi-Jiangyou area as a whole distributes on structural highs.In the areas to the south of Shuangyushi,the Qixia Fm dolomite reservoirs of platform margins are continuously developed.In conclusion,these auxiliary technologies can effectively allow trap identification and thin reservoir prediction in complex structures in the study area.In addition to clarifying the exploration orientation and providing a necessarily technical supports forwell development,these technologies help to accelerate the construction of demonstration projects for the exploration and development of deep marine carbonate formations.展开更多
Modern industrial equipment is increasingly characterized by miniaturization,integration,and high performance,necessitating the production of complex structural parts with exceptionally high internal surface quality.D...Modern industrial equipment is increasingly characterized by miniaturization,integration,and high performance,necessitating the production of complex structural parts with exceptionally high internal surface quality.Direct manufacturing often leads to high internal surface roughness,which traditional finishing and measuring methods cannot adequately address due to the decreasing size and increasing complexity of internal structures.This is especially true for components like pipes with large aspect ratios,extremely small deep holes,multi-stage bends,cross pipes,and array holes.To meet the high-performance manufacturing demands of these parts,advanced internal surface finishing and roughness measurement technologies have gained significant attention.This review focuses on the challenges and solutions related to internal surface parts with various apertures and complex structures.Internal surface finishing methods are categorized into mechanical finishing,fluid-based finishing,and energy-field-based finishing based on their characteristics.Roughness measurement technologies are divided into tool-probing and non-probing methods.The principles,required equipment,and key parameters of each finishing and measurement approach are discussed in detail.Additionally,the advantages and limitations of these methods are summarized,and future trends are forecasted.This paper serves as a comprehensive guide for researchers and engineers aiming to enhance the internal surface quality of complex structure parts.展开更多
The demand for lightweight and multifunctional surface structure in high-end equipment is steadily growing.The harmonization between flexibility and electromagnetic tunability has become a significant subject for stea...The demand for lightweight and multifunctional surface structure in high-end equipment is steadily growing.The harmonization between flexibility and electromagnetic tunability has become a significant subject for stealth morphing aircraft.This paper presents a microwave absorbing structure based on the kirigami configuration,aiming at improving the conformality with the negative Poisson’s ratio characteristic and expanding the radar stealth range with tunability.A precise electromagnetic reflectivity model of the impedance surface was established by the inversion method,and an integrated optimization algorithm was employed to optimize the structural parameters based on numerical analysis.Specimens composed of thermoplastic polyurethane elastic colloids and resistive materials were prepared to assess the in-plane mechanical tensile and electromagnetic absorption performances through experimental methods.The results indicate that the original absorption band spans 6.2-11.1 GHz,shifts to 8-18 GHz with stretching at a panel rotation angle of 16°,and remains nearly constant for further stretching.The specimens adhere to complex curved surfaces well in experiments and maintain the electromagnetic absorption performance compared with flat surfaces.This research offers a valuable reference for designing electromagnetic stealth structures that are highly stretchable and adjustable.展开更多
Two Cu(Ⅱ) complexes of [Cu(2,6-DPC)(Hnta)(H2O)]·H2O(2,6-DPC = 2,6-pyridinedicarboxylic-carboxylate, Hnta = nicotinic acid) and [Cu2(2,4-D)4(Hnta)2](2,4-D = 2,4-dichlorophenoxyacetic-carboxylate) were synthesized...Two Cu(Ⅱ) complexes of [Cu(2,6-DPC)(Hnta)(H2O)]·H2O(2,6-DPC = 2,6-pyridinedicarboxylic-carboxylate, Hnta = nicotinic acid) and [Cu2(2,4-D)4(Hnta)2](2,4-D = 2,4-dichlorophenoxyacetic-carboxylate) were synthesized and successfully obtained as single crystals in this paper. The supramolecular structures of the complexes from zero to three dimensions and the weak intermolecular force in the crystal were analyzed. The single-crystal structures of the complexes were further analyzed by Hirshfeld surface analysis. The competition capacity of the complexes about calf thymus DNA(ct-DNA) was also analyzed by fluorescence spectroscopy. The ability of complexes to cleave the plasmid DNA(pBR322-DNA) was determined by gel electrophoresis assay. And at last, the complexes’ cytotoxic activities were reviewed for four kinds of cancer cell lines(HeLa, MCF-7, HepG, SKOV-3), showing that the coordination polymer has anti-tumor activity and cytotoxicity.展开更多
To understand the mechanical response pattern of the existing structure and ground due to the construction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and str...To understand the mechanical response pattern of the existing structure and ground due to the construction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and stress variation of the existing structure and the effect of underground carriageway structures on the surface subsidence.The curves of the maximum differential subsidence,torsion angle,and distortion of the cross-section of the existing structure show two peaks in succession during traversing of two metro tunnels beneath it.The torsion angle of the existing structure changes when the two tunnels traverse beneath it in opposite directions.The first traversing of the shield tunnel mainly induces the magnitude variation in torsional deformation of the existing structure,but the second traversing of the subsurface tunnel may cause a dynamic change in the magnitude and form of torsional deformation in the existing structure.The shielding effect can reduce the surface subsidence caused by metro tunnel excavation to a certain extent,and the development trend of subsidence becomes slower as the excavation continues.展开更多
The research progress of soil loss under the dual structure of southwest karst is systematically studied. The results show that the research of the soil erosion in karst mountainous area started late, and the basic re...The research progress of soil loss under the dual structure of southwest karst is systematically studied. The results show that the research of the soil erosion in karst mountainous area started late, and the basic research is lagging. Most of the existing research results focus on the present situation, causes and control measures of surface erosion. The view of underground soil loss in the context of karst diploid structure has been recognized by most scholars. However, limited to the research methods and the lack of observational data, the way of underground soil loss, the amount of loss and its harm are still unclear. Therefore, seeking the necessary technical means to carry out the necessary field observation from the way and process of loss is the focus of the study of soil loss under karst structure in the future.展开更多
The surrounding geological conditions and supporting structures of underground engineering are often updated during construction,and these updates require repeated numerical modeling.To improve the numerical modeling ...The surrounding geological conditions and supporting structures of underground engineering are often updated during construction,and these updates require repeated numerical modeling.To improve the numerical modeling efficiency of underground engineering,a modularized and parametric modeling cloud server is developed by using Python codes.The basic framework of the cloud server is as follows:input the modeling parameters into the web platform,implement Rhino software and FLAC3D software to model and run simulations in the cloud server,and return the simulation results to the web platform.The modeling program can automatically generate instructions that can run the modeling process in Rhino based on the input modeling parameters.The main modules of the modeling program include modeling the 3D geological structures,the underground engineering structures,and the supporting structures as well as meshing the geometric models.In particular,various cross-sections of underground caverns are crafted as parametricmodules in themodeling program.Themodularized and parametric modeling program is used for a finite element simulation of the underground powerhouse of the Shuangjiangkou Hydropower Station.This complicatedmodel is rapidly generated for the simulation,and the simulation results are reasonable.Thus,this modularized and parametric modeling program is applicable for three-dimensional finite element simulations and analyses.展开更多
基金supported by the National Natural Science Foundation of China(No.20801012)New Energy Technology Co.Ltd.of Ai Naji of Jiangsu Province(No.8507040091)
文摘The crystal structure of one novel Mn（II） complex, [Mn（pmta）_3]_2[Mn（H_2O）_6]·4H_2O（1）, is reported（Hpmta = 5-methyl-1-phenyl-1H-1,2,3-triazole-4-carboxylic acid）. In the title compound, the asymmetric unit consists of a [Mn（pmta_）3]ˉ anion, half [Mn（H_2O）_6]^（2＋） counter cation and two lattice H_2O molecules, and the intra- and intermolecular hydrogen bonds connect the complex into a supramolecular structure. The liquid-state fluorescence spectra of complex 1 have been determined. Hirshfeld surface analysis was also studied. The main intermolecular interactions in the complex are O···H and H···H contacts.
基金National Natural Science Foundation of China under Grant No.52108453Natural Science Foundation of Jiangxi Province of China under Grant No.20212BAB214014+1 种基金National Key R&D Program of China under Grant No.2018YFC1504305Joint Funds of the National Natural Science Foundation of China under Grant No.U1839201。
文摘The response displacement method(RDM)is recommended for the seismic analysis of underground structures in the transverse direction for many codes,including bases for design of structures-seismic actions for designing geotechnical works(ISO 23469)and code for seismic design of urban rail transit structures(GB 50909-2014).However,there are some obvious limitations in the application of RDM.Springs and the shear stress of the soil could be approximately evaluated for the structures having a simple cross section,such as rectangular and circular structures.It is necessary to propose simplified seismic analysis methods for structures with complex cross sections.This paper refers to the idea of RDM and proposes three generalized response displacement methods(GRDM).In GRDM1,a part of the soil surrounding a structure is selected to generate a generalized underground structure with a rectangular cross section,and the same analysis model as RDM is applied to analyze the responses of the structure.In GRDM2,a hollow soil model without a generalized structure is used to compute the equivalent load caused by the relative displacement of the soil,and the soil-structure interaction model is applied to calculate the responses of the structure.In GRDM3,a continuous soil model is applied to compute the equivalent load caused by the relative displacement and shear stress of the soil,and the soil-structure interaction model is applied to analyze the responses of the structure,which is the same as the model used in GRDM2.The time-history analysis method(THAM)is used to evaluate the accuracy of the proposed simplified methods.Results show that the error of GRDM1 is about 20%,while the error is only 5%for GRDM2 and GRDM3.Among the three proposed methods,GRDM3 has obvious advantages regarding calculation efficiency and accuracy.Therefore,it is recommended to use GRDM3 for the seismic response analysis of underground structures that have conventional simple or complex cross sections.
基金National Natural Science Foundation of China (50635040)National High-tech Research and Development Program (2009AA04Z302)Jiangsu Provincial Natural Science Foundation (BK2008043)
文摘Electrochemical micromachining （EMM） technology for fabricating micro structures is presented in this article. By applying ultra short pulses, dissolution of a workpiece can be restricted to the region very close to the electrode. First, an EMM system for meeting the requirements of the EMM process is established. Second, sets of experiments is carried out to investigate the influence of some of the predominant electrochemical process parameters such as electrical parameters, feed rate, electrode geometry features and electrolyte composition on machining quality, especially the influences of pulse on time on shape precision and working end shape of electrode on machined surface quality. Finally, after the preliminary experiments, a complex microstructure with good shape precision and surface quality is successfully obtained.
基金Project supported by the National Major Science and Technology Project“Development of Large Oil/Gas Fields and Coalbed Methane”(No.2016ZX05004-005&2016ZX05007-004)the CNPC Major Science and Technology Project“Research and application of key technologies for maintaining gas productivity of 30 billion cubic meters in Southwest Oil and Gas Fields”(No.2016E-06,2016E-0602,2016E-0603&2016E-0604).
文摘The northern Sichuan Basin,spreading in the northern section of the Longmenshan Fault Fold Belt,is characterized by dramatic fluctuations in the surface landforms,development of abdominal faults,and low-quality seismic data,resulting in difficulties in clarifying relevant structures.The key target formation,the Mid-Permian Qixia Fm,is deeply buried with thin reservoirs and high heterogeneity,which brings great challenges to seismic prediction.Under such circumstances,researches have been conducted jointly in terms of seismic data acquisition,processing and interpretation,and finally some relevant seismic survey technologies were developed suitable for surface/underground complex structures.Through surface structural surveys,dynamic deep-well lithologic identification,single-point detector deployment and process optimization,acquisition parameters can be excited.In addition,by using an observation systemwith high-coverage,wide-azimuth and huge-displacement,quality of acquired seismic data can be enhanced dramatically.Seismic imaging technologies for complex structures have been developed to enhance the quality of images for deep formations.These technologies are dominated by microscopic logging-constrained tomography static correction,high-resolution processing with fidelity and amplitude preservation and all-around PSDM in an angular domain.By using high-resolution gravity,magnetic and electric data,details related to geological structures and faults can be identified.In combination with fine seismic data interpretation,structural details and fault features can be verified effectively.Based on forwardmodeling and fine seismic calibration of reservoirs in individualwells,suitable attributes can be identified for predictions related to the distribution of reservoirs.By using all these auxiliary technologies,a large-scale structuralelithologic composite trap with a total area of 1223 km^(2) has been discovered in the NW Sichuan Basin.The Shuangyushi-Jiangyou area as a whole distributes on structural highs.In the areas to the south of Shuangyushi,the Qixia Fm dolomite reservoirs of platform margins are continuously developed.In conclusion,these auxiliary technologies can effectively allow trap identification and thin reservoir prediction in complex structures in the study area.In addition to clarifying the exploration orientation and providing a necessarily technical supports forwell development,these technologies help to accelerate the construction of demonstration projects for the exploration and development of deep marine carbonate formations.
基金the financial supports from National Key R&D Program of China(No.2022YFB3403301)the Funds for International Cooperation and Exchange of the National Natural Science Foundation of China(No.52311530080)。
文摘Modern industrial equipment is increasingly characterized by miniaturization,integration,and high performance,necessitating the production of complex structural parts with exceptionally high internal surface quality.Direct manufacturing often leads to high internal surface roughness,which traditional finishing and measuring methods cannot adequately address due to the decreasing size and increasing complexity of internal structures.This is especially true for components like pipes with large aspect ratios,extremely small deep holes,multi-stage bends,cross pipes,and array holes.To meet the high-performance manufacturing demands of these parts,advanced internal surface finishing and roughness measurement technologies have gained significant attention.This review focuses on the challenges and solutions related to internal surface parts with various apertures and complex structures.Internal surface finishing methods are categorized into mechanical finishing,fluid-based finishing,and energy-field-based finishing based on their characteristics.Roughness measurement technologies are divided into tool-probing and non-probing methods.The principles,required equipment,and key parameters of each finishing and measurement approach are discussed in detail.Additionally,the advantages and limitations of these methods are summarized,and future trends are forecasted.This paper serves as a comprehensive guide for researchers and engineers aiming to enhance the internal surface quality of complex structure parts.
基金supported by the National Key Research and Development of China(Grant No.2022YFB4601901)the National Natural Science Foundation of China(Grant Nos.12122202 and 12302078)the Postdoctoral Innovative Talents Support Program of China(Grant No.BX20230470).
文摘The demand for lightweight and multifunctional surface structure in high-end equipment is steadily growing.The harmonization between flexibility and electromagnetic tunability has become a significant subject for stealth morphing aircraft.This paper presents a microwave absorbing structure based on the kirigami configuration,aiming at improving the conformality with the negative Poisson’s ratio characteristic and expanding the radar stealth range with tunability.A precise electromagnetic reflectivity model of the impedance surface was established by the inversion method,and an integrated optimization algorithm was employed to optimize the structural parameters based on numerical analysis.Specimens composed of thermoplastic polyurethane elastic colloids and resistive materials were prepared to assess the in-plane mechanical tensile and electromagnetic absorption performances through experimental methods.The results indicate that the original absorption band spans 6.2-11.1 GHz,shifts to 8-18 GHz with stretching at a panel rotation angle of 16°,and remains nearly constant for further stretching.The specimens adhere to complex curved surfaces well in experiments and maintain the electromagnetic absorption performance compared with flat surfaces.This research offers a valuable reference for designing electromagnetic stealth structures that are highly stretchable and adjustable.
基金Supported by the Guizhou Provincial Science and Technology Foundation(No.LKLS[2013]20)the Scientific and Technological Innovation Platform of Liupanshui(52020-2018-02-01 and 52020-2017-02-02)+1 种基金Youth Talent Growth Project of Educational Department of Guizhou Province(No.KY [2017]271)2011 Collaborative Innovation Center of Guizhou Province(Qian Jiao he xietongchuangxin zi [2016]02)
文摘Two Cu(Ⅱ) complexes of [Cu(2,6-DPC)(Hnta)(H2O)]·H2O(2,6-DPC = 2,6-pyridinedicarboxylic-carboxylate, Hnta = nicotinic acid) and [Cu2(2,4-D)4(Hnta)2](2,4-D = 2,4-dichlorophenoxyacetic-carboxylate) were synthesized and successfully obtained as single crystals in this paper. The supramolecular structures of the complexes from zero to three dimensions and the weak intermolecular force in the crystal were analyzed. The single-crystal structures of the complexes were further analyzed by Hirshfeld surface analysis. The competition capacity of the complexes about calf thymus DNA(ct-DNA) was also analyzed by fluorescence spectroscopy. The ability of complexes to cleave the plasmid DNA(pBR322-DNA) was determined by gel electrophoresis assay. And at last, the complexes’ cytotoxic activities were reviewed for four kinds of cancer cell lines(HeLa, MCF-7, HepG, SKOV-3), showing that the coordination polymer has anti-tumor activity and cytotoxicity.
基金National Natural Science Foundation of China,Grant/Award Numbers:51878060,52078046。
文摘To understand the mechanical response pattern of the existing structure and ground due to the construction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and stress variation of the existing structure and the effect of underground carriageway structures on the surface subsidence.The curves of the maximum differential subsidence,torsion angle,and distortion of the cross-section of the existing structure show two peaks in succession during traversing of two metro tunnels beneath it.The torsion angle of the existing structure changes when the two tunnels traverse beneath it in opposite directions.The first traversing of the shield tunnel mainly induces the magnitude variation in torsional deformation of the existing structure,but the second traversing of the subsurface tunnel may cause a dynamic change in the magnitude and form of torsional deformation in the existing structure.The shielding effect can reduce the surface subsidence caused by metro tunnel excavation to a certain extent,and the development trend of subsidence becomes slower as the excavation continues.
基金Supported by the National Science&Technology Pillar Program during the Twelfth FiveYear Plan Period of China(2012BAD05B06)the Fund Program for Science and Technology of Guizhou in 2012(Qiankehe Code J LKS[2012]No.27~~
文摘The research progress of soil loss under the dual structure of southwest karst is systematically studied. The results show that the research of the soil erosion in karst mountainous area started late, and the basic research is lagging. Most of the existing research results focus on the present situation, causes and control measures of surface erosion. The view of underground soil loss in the context of karst diploid structure has been recognized by most scholars. However, limited to the research methods and the lack of observational data, the way of underground soil loss, the amount of loss and its harm are still unclear. Therefore, seeking the necessary technical means to carry out the necessary field observation from the way and process of loss is the focus of the study of soil loss under karst structure in the future.
基金The Construction S&T Project of the Department of Transportation of Sichuan Province(Grant No.2023A02)the National Natural Science Foundation of China(No.52109135).
文摘The surrounding geological conditions and supporting structures of underground engineering are often updated during construction,and these updates require repeated numerical modeling.To improve the numerical modeling efficiency of underground engineering,a modularized and parametric modeling cloud server is developed by using Python codes.The basic framework of the cloud server is as follows:input the modeling parameters into the web platform,implement Rhino software and FLAC3D software to model and run simulations in the cloud server,and return the simulation results to the web platform.The modeling program can automatically generate instructions that can run the modeling process in Rhino based on the input modeling parameters.The main modules of the modeling program include modeling the 3D geological structures,the underground engineering structures,and the supporting structures as well as meshing the geometric models.In particular,various cross-sections of underground caverns are crafted as parametricmodules in themodeling program.Themodularized and parametric modeling program is used for a finite element simulation of the underground powerhouse of the Shuangjiangkou Hydropower Station.This complicatedmodel is rapidly generated for the simulation,and the simulation results are reasonable.Thus,this modularized and parametric modeling program is applicable for three-dimensional finite element simulations and analyses.
