During the chemical weathering of the uranium mill tailings,released uranium could be immobilized by the newly formed secondary minerals such as oxyhydroxides.A deeper understanding of the interaction between uranium ...During the chemical weathering of the uranium mill tailings,released uranium could be immobilized by the newly formed secondary minerals such as oxyhydroxides.A deeper understanding of the interaction between uranium and common oxyhydroxides under environmental conditions is necessary.In this work,uranium sorption behaviors on Al-,Mn-and Fe-oxyhydroxide minerals(boehmite,manganite,goethite,and lepidocrocite)were investigated by batch experiments.Results showed that the uranium sorption on Al-oxyhydroxide behaved significantly differently from the other three minerals.The sorption edge of the Mn-and Fe-oxyhydroxides located around pH 5,while the sorption edge of boehmite shifted about 1.5 pH unit to near neutral.The sorption isotherms of uranium on manganite,goethite and lepidocrocite at pH 5.0 could be well fitted by the Langmuir model.Instead of surface complexation,sorption on boehmite happened mainly by uranium-bearing carbonates and hydroxides precipitation as illustrated by the characterization results.Both carbonate and phosphate strongly affected the uranium sorption behavior.The removal efficiency of uranium by boehmite exceeded 98%after three sorption-desorption cycles,indicating it may be a potential material for uranium removal and recovery.展开更多
The complexation of phosphates in the quartz-metal ion-H_2O-oleate system was studied. Computer assisted calculations with the aid of the advanced program SOLGASWATER and known equilibrium constants were used to evalu...The complexation of phosphates in the quartz-metal ion-H_2O-oleate system was studied. Computer assisted calculations with the aid of the advanced program SOLGASWATER and known equilibrium constants were used to evaluate the mechanism,The calculation results revealed that in the presence of a certain amount of phosphates, metal ions adsorbed at the quartz-H_2O interface will be transferred into solution.Thus the competi- tion for metal ions between phosphates and the quartz surface leads to surface deactivation and re- duced floatability.Various distribution diagrams clearly demonstrate the change of surface complexation as a function of added phosphate concentration.The deactivation products were also evaluated.展开更多
The immobilisation of radionuclides in groundwater environments cannot be explained solely by the empirical models.These empirical models are not sen-sitive to the varying conditions that are found in nature.Sorption ...The immobilisation of radionuclides in groundwater environments cannot be explained solely by the empirical models.These empirical models are not sen-sitive to the varying conditions that are found in nature.Sorption has been shown to be very sensitive to pH,Eh and ionic strength of the solution in which the radionuclides are found.Batch sorption experiments at different ionic strengths were conducted and LogK constants for the sorption processes were determined.JChess Geochemical code was used to compare experimentally and predicted Log K constants obtained from surface complexation reactions with different granitic rock samples.For pH dependent sorption,1×10^(-5) mol·dm^(-3) solutions of NiCl_(2) were prepared,and the pH was adjusted from 4 to 11,with intervals of 0.6 to 0.8 on the pH scale using NaOH(aq)and HCl(aq).Different concentrations of pH adjusting solutions were made from very weak to very strong acid or base.Sample separation was performed and counting was performed for Ni using the scintillation counter.Packard TRI-CARB 2750 TR/LL Liquid Scintillation Counter:Used for Ni sorption studies,counting from 0 to 67 keV to 2σ.Results showed varying sorption properties from one granitic mineral to the other.There was no effect of ionic strength on the sorp-tion of Ni to Muscovite Mica(MM).Varying pH sorption isotherms for Ni sorption to Orthoclase Feldspar,showed experimental data and modelled matched for monodentate and bi dentate sorption using the same experimental conditions,modelling done assuming mono and bidentate complex formation.The following conclusions can be made after studying varying pH sorption profiles of selected granitic rocks and mineral in different NaCl concentrations,using different models.Ni sorption is suppressed in the presence of NaCl,due to competition for the sorption sites.展开更多
On-machine measurement(OMM)stands out as a pivotal technology in complex curved surface adaptive machining.However,the complex structure inherent in workpieces poses a significant challenge as the stylus orientation f...On-machine measurement(OMM)stands out as a pivotal technology in complex curved surface adaptive machining.However,the complex structure inherent in workpieces poses a significant challenge as the stylus orientation frequently shifts during the measurement process.Consequently,a substantial amount of time is allocated to calibrating pre-travel error and probe movement.Furthermore,the frequent movement of machine tools also increases the influence of machine errors.To enhance both accuracy and efficiency,an optimization strategy for the OMM process is proposed.Based on the kinematic chain of the machine tools,the relationship between the angle combination of rotary axes,the stylus orientation,and the calibration position of pre-travel error is disclosed.Additionally,an OMM efficiency optimization model for complex curved surfaces is developed.This model is solved to produce the optimal efficiency angle combinations for each to-be-measured point.Within each angle combination,the effects of positioning errors on measurement results are addressed by coordinate system offset and measurement result compensation method.Finally,the experiments on an impeller are used to demonstrate the practical utility of the proposed method.展开更多
In areas with a complex surface,the acquisition and processing of seismic data is a great challenge.Although elevation-static corrections can be used to eliminate the influences of topography,the distortions of seismi...In areas with a complex surface,the acquisition and processing of seismic data is a great challenge.Although elevation-static corrections can be used to eliminate the influences of topography,the distortions of seismic wavefields caused by simple vertical time shifts still greatly degrade the quality of the migrated images.Ray-based migration methods which can extrapolate and image the wavefields directly from the rugged topography are efficient ways to solve the problems mentioned above.In this paper,we carry out a study of prestack Gaussian beam depth migration under complex surface conditions.We modify the slant stack formula in order to contain the information of surface elevations and get an improved method with more accuracy by compositing local plane-wave components directly from the complex surface.First,we introduce the basic rules and computational procedures of conventional Gaussian beam migration.Then,we give the original method of Gaussian beam migration under complex surface conditions and an improved method in this paper.Finally,we validate the effectiveness of the improved method with trials of model and real data.展开更多
The interaction between radionuclides and solid/water interfaces is important to understand the physicochemical processes of radionuclides in the natural environment.Herein,the interaction of 60Co(Ⅱ) with TiO 2 in aq...The interaction between radionuclides and solid/water interfaces is important to understand the physicochemical processes of radionuclides in the natural environment.Herein,the interaction of 60Co(Ⅱ) with TiO 2 in aqueous solution as a function of pH and ionic strength was studied by using batch technique combined with surface complexation model and density functional theory(DFT) calculations.The batch experimental results showed that the adsorption of 60Co(Ⅱ) was dependent on pH and independent of ionic strength,indicating the formation of inner-sphere surface complexes on TiO 2 surfaces.The results of surface complexation models and DFT calculations indicated that the surface species of 60Co(Ⅱ) adsorbed on TiO 2 followed the trend:B structure(i.e.,60Co(Ⅱ) was linked to one bridge oxygen site) was the dominant surface species at low pH,and TT structure(i.e.,60Co(Ⅱ) was linked to two terminal oxygen sites) became the important surface complex at neutral and alkaline pH values.These results demonstrated that a multi-technique approach could lead to definitive information on the structures of adsorbed 60Co(Ⅱ) at the molecular level at the TiO 2 /water interfaces,as well as realistic models to rationalize and accurately evaluate the macroscopic manifestations of radionuclide adsorption phenomena.展开更多
Airborne laser scanning （ALS） is a technique used to obtain Digital Surface Models （DSM） and Digital Terrain Models （DTM） efficiently, and filtering is the key procedure used to derive DTM from point clouds. Gen...Airborne laser scanning （ALS） is a technique used to obtain Digital Surface Models （DSM） and Digital Terrain Models （DTM） efficiently, and filtering is the key procedure used to derive DTM from point clouds. Generating seed points is an initial step for most filtering algorithms, whereas existing algorithms usually define a regular window size to generate seed points. This may lead to an inadequate density of seed points, and further introduce error type I, especially in steep terrain and forested areas. In this study, we propose the use of object- based analysis to derive surface complexity information from ALS datasets, which can then be used to improve seed point generation. We assume that an area is complex if it is composed of many small objects, with no buildings within the area. Using these assumptions, we propose and implement a new segmentation algorithm based on a grid index, which we call the Edge and Slope Restricted Region Growing （ESRGG） algorithm. Surface complexity information is obtained by statistical analysis of the number of objects derived by segmentation in each area. Then, for complex areas, a smaller window size is defined to generate seed points. Experimental results show that the proposed algorithm could greatly improve the filtering results in complex areas, especially in steep terrain and forested areas.展开更多
Large,3D curved electronics are a trend of the microelectronic industry due to their unique ability to conformally coexist with complex surfaces while retaining the electronic functions of 2D planar integrated circuit...Large,3D curved electronics are a trend of the microelectronic industry due to their unique ability to conformally coexist with complex surfaces while retaining the electronic functions of 2D planar integrated circuit technologies.However,these curved electronics present great challenges to the fabrication processes.Here,we propose a reconfigurable,mask-free,conformal fabrication strategy with a robot-like system,called robotized‘transfer-and-jet’printing,to assemble diverse electronic devices on complex surfaces.This novel method is a ground-breaking advance with the unique capability to integrate rigid chips,flexible electronics,and conformal circuits on complex surfaces.Critically,each process,including transfer printing,inkjet printing,and plasma treating,are mask-free,digitalized,and programmable.The robotization techniques,including measurement,surface reconstruction and localization,and path programming,break through the fundamental constraints of 2D planar microfabrication in the context of geometric shape and size.The transfer printing begins with the laser lift-off of rigid chips or flexible electronics from donor substrates,which are then transferred onto a curved surface via a dexterous robotic palm.Then the robotic electrohydrodynamic printing directly writes submicrometer structures on the curved surface.Their permutation and combination allow versatile conformal microfabrication.Finally,robotized hybrid printing is utilized to successfully fabricate a conformal heater and antenna on a spherical surface and a flexible smart sensing skin on a winged model,where the curved circuit,flexible capacitive and piezoelectric sensor arrays,and rigid digital–analog conversion chips are assembled.Robotized hybrid printing is an innovative printing technology,enabling additive,noncontact and digital microfabrication for 3D curved electronics.展开更多
To improve the grinding quality of robotic belt grinding systems for the workpieces with complex shaped surfaces, new concepts of the dexterity grinding point and the dexterity grinding space are proposed and their ma...To improve the grinding quality of robotic belt grinding systems for the workpieces with complex shaped surfaces, new concepts of the dexterity grinding point and the dexterity grinding space are proposed and their mathematical descriptions are defined. Factors influencing the dexterity grinding space are analyzed. And a method to determine the necessary dexterity grinding space is suggested. Based on particle swarm optimization （PSO） method, a strategy to optimize the grinding robot structural dimensions and position with respect to the grinding wheel is put forward to obtain the necessary dexterity grinding space. Finally, to grind an aerial engine blade, a dedicated PPPRRR （P： prismatic R： rotary） grinding robot structural dimensions and position with respect to the grinding wheel are optimized using the above strategy. According to simulation results, if the blade is placed within the dexterity grinding space, only one gripper and one grinding machine are needed to grind its complex shaped surfaces.展开更多
Taking AutoCAD2000 as platform, an algorithm for the reconstruction ofsurface from scattered data points based on VBA is presented. With this core technology customerscan be free from traditional AutoCAD as an electro...Taking AutoCAD2000 as platform, an algorithm for the reconstruction ofsurface from scattered data points based on VBA is presented. With this core technology customerscan be free from traditional AutoCAD as an electronic board and begin to create actual presentationof real-world objects. VBA is not only a very powerful tool of development, but with very simplesyntax. Associating with those solids, objects and commands of AutoCAD 2000, VBA notably simplifiesprevious complex algorithms, graphical presentations and processing, etc. Meanwhile, it can avoidappearance of complex data structure and data format in reverse design with other modeling software.Applying VBA to reverse engineering can greatly improve modeling efficiency and facilitate surfacereconstruction.展开更多
The aim of this study was to investigate the inhibitory effect of heparin/fibronectin （Hep/Fn） complexes on neointimal hyperplasia following endovascular intervention. Hep/Fn complexes were immobilized onto titanium...The aim of this study was to investigate the inhibitory effect of heparin/fibronectin （Hep/Fn） complexes on neointimal hyperplasia following endovascular intervention. Hep/Fn complexes were immobilized onto titanium （Ti） surfaces, with subsequent X-ray photoelectron spectroscopy （XPS）, Toluidine Blue 0 （TBO） and immunohistochemistry methods were used to characterize surface properties. Smooth muscle cell （SMC） cultures were used to evaluate the effect of Hep/Fn complexes on SMC proliferation. Results showed that Hep/Fn complexes successfully immobilized onto Ti surfaces and resulted in an inhibition of SMC proliferation. This study suggests that Hep/Fn surface-immobilized biomaterials develop as a new generation of biomaterials to prevent neointimal hyperplasia, particularly for use in cardiovascular implants.展开更多
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
Aimed at inner quality controlling for complex surface parts, an ultrasonic testing system for complex surface parts has been developed using ultrasonic NDT(Non-destructive Testing)which has features of strong penetra...Aimed at inner quality controlling for complex surface parts, an ultrasonic testing system for complex surface parts has been developed using ultrasonic NDT(Non-destructive Testing)which has features of strong penetration, well direction, high sensitivity, low cost, and harmless to people and material. The technologies of the computer, NC (Numerical control), precision mechanism, signal analysis and processing were integrated in the testing system. The system includes a PC, system software, ultrasonic data acquisition card, stepper motor drive card and five-axis precision mechanical device, etc. The software was developed using WIN98-based VC++. According to CAD data of the parts and interpolation methods, the scanning programs can be programmed. The five-axis scanning system is driven by the CNC(computer numerical control) system to control the attitude of ultrasonic probes. The system’s automatic scanning for complex surface parts, real-time acquiring ultrasonic data and automatic identifying flaw signal have been realized. This system can be used not only for testing complex surface parts, but for testing random curve parts. With fast testing speed, high sensitivity, high testing precision and high reliability, the system has a wide adaptability.展开更多
Parts of complex surface are widely used now in many fields, and their detection has caused much concern. In China many manufactories still carry on the traditional way of manual detection, which requires highly skill...Parts of complex surface are widely used now in many fields, and their detection has caused much concern. In China many manufactories still carry on the traditional way of manual detection, which requires highly skilled personnel and efficiency is low. Some large manufactories have imported auto-detecting equipments, which require CAD data on the parts, or just divide the surface into several approximate planes for automatic detection. Phased-array system is seldom used, and the cost is high. Besides, most of the systems have not considered the automatic sensitivity compensation of parts with varying thickness. To improve the detection quality and efficiency of nondestructive test (NDT) of parts of complex surface, this paper puts forward an integrated ultrasonic NDT system characterized by: (1) Use of ultrasonic measurement and reverse of curved surface to solve the CAD data problem; (2) Use of an automatic sensitivity compensation algorithm (based on the part’s modelling information obtained in surface reverse) to fit the variety of the thickness; (3) Use of template matching and pseudo-color imaging to improve the quality of detection results. The system features integration of low cost mature technologies, and is suitable for detection of various parts of different complex surfaces in medium-and-small enterprises. The test results showed that the system can automatically detect parts of complex surface successfully, and that the inspection result is good and reliable.展开更多
Walkaway VSP cannot obtain accurate velocity field,as it asymmetrically reflects ray path and provides uneven coverage to underground target,thereby presenting issues related to imaging quality.In this study,we propos...Walkaway VSP cannot obtain accurate velocity field,as it asymmetrically reflects ray path and provides uneven coverage to underground target,thereby presenting issues related to imaging quality.In this study,we propose combining traveltime tomography and prestack depth migration for VSP of an angle-domain walkaway,in a bid to establish accurate two-dimensional and three-dimensional(3 D)velocity models.First,residual curvature was defined to update velocity,and an accurate velocity field was established.To establish a high-precision velocity model,we deduced the relationship between the residual depth and traveltime of common imaging gathers(CIGs)in walkaway VSP.Solving renewal velocity using the least squares method,a four-parameter tomographic inversion equation was derived comprising formation dip angle,incidence angle,residual depth,and sensitivity matrix.In the angle domain,the reflected wave was divided into up-and down-transmitted waves and their traveltimes were calculated.The systematic cumulative method was employed in prestack depth migration of a complex surface.Through prestack depth migration,the offset-domain CIGs were obtained,and dip angle was established by defining the stack section horizon.Runge–Kutta ray tracing was employed to calculate the ray path from the reflection point to the detection point,to determine the incident angle,and to subsequently calculate the ray path from the reflection point to the irregular surface.The offset-domain residual depths were mapped to the angle domain,and a new tomographic equation was established and solved.Application in the double complex area of the Tarim Basin showed the four-parameter tomographic inversion equation derived in this paper to be both correct and practical and that the migration algorithm was able to adapt to the complex surface.展开更多
A novel method for preparing metalllzed film has been studied.The reduction process and properties of the poly(vinyl alcohol)(PVA)were probed by several analytic means.According to the etudies,a mechanism for the poly...A novel method for preparing metalllzed film has been studied.The reduction process and properties of the poly(vinyl alcohol)(PVA)were probed by several analytic means.According to the etudies,a mechanism for the polymer surface reduction metallization was proposed and proved.展开更多
The earth surface in the Sichuan Basin and its periphery is geologically complex,which causes low signal-to-noise ratio of seismic data,poor imaging quality of seismic profiles and great difficulty in data acquisition...The earth surface in the Sichuan Basin and its periphery is geologically complex,which causes low signal-to-noise ratio of seismic data,poor imaging quality of seismic profiles and great difficulty in data acquisition.In order to ensure high-quality operation of the seismic survey project in the complex surface of the Sichuan Basin,researchers have been working continuously to solve the bottleneck problems in the seismic acquisition technology for complex surface in recent years.In addition,the upgrading of acquisition technology and operation capacity is promoted effectively by means of technical innovation,and a series of key technologies for seismic acquisition are developed.And the following application results of this series of technologies are obtained.First,the optimization design technology of the geometry based on wave equation forward modeling and actual data,combined with prestack migration imaging can show the influence of different acquisition schemes on the prestack imaging effect of complex targets more directly,which makes the seismic acquisition scheme more economic and effective.Second,by extracting landform risks and surface obstacle information intelligently,combined with field fine reconnaissance,landform risk identification and hierarchical evaluation and indoors intelligent optimization of well-shot physical point deployment are conducted,and thus the GISt intelligent deployment technology of shot point in complex surface is formed,which effectively reduces the risks of operation.Third,the cavity excitation technology which reduces the initial pressure of explosive pulse and extends the explosive action time of explosives can increase the conversion rate of rock excitation energy into effective elastic wave energy and the reflected energy and improve the quality of seismic single shot data.Fourth,combination of the automatic evaluation technology for field seismic data acquired in mountainous regions and the KL-GMLiveQC1.0 software can improve the evaluation efficiency,reduce the evaluation cost and ensure the high-quality acquisition of seismic data in complex surface.In conclusion,this series of key seismic acquisition technologies greatly improve the signal-to-noise ratio and resolution of seismic data,lay a foundation for fine reservoir prediction,and ensure the continuous important breakthrough of three-dimensional natural gas exploration and development in the gas fields of marine carbonate rock,shale gas,volcanic rock and shallow tight sandstone gas in the Sichuan Basin.展开更多
This study investigates the potential of natural Brown Coal(BC)as a sustainable,cost-effective adsorbent for the removal of manganese(Mn2+)from contaminated groundwater.A series of batch adsorp-tion experiments was co...This study investigates the potential of natural Brown Coal(BC)as a sustainable,cost-effective adsorbent for the removal of manganese(Mn2+)from contaminated groundwater.A series of batch adsorp-tion experiments was conducted to assess the influence of key operational parameters—such as solution pH,2+initial Mn concentration,BC dosage,temperature,and the presence of competing ions—on 2+Mn removal efficiency.The environmental compatibility and regeneration potential of BC were also evaluated to deter-mine its practical viability for repeated use.To better understand the adsorption behaviour,equilibrium and kinetic data were analysed using established isotherm and kinetic models,while thermodynamic parameters were computed to assess the spontaneity and thermal characteristics of the adsorption process.Furthermore,geochemical modelling and comprehensive BC characterization—including surface morphology,miner-alogical and elemental composition,and functional group analysis—were 2+performed to elucidate Mn speciation under varying environmental conditions and to uncover the underlying adsorption mechanisms.2+Results showed that Mn removal efficiency increased with higher pH,temperature,and BC dosage,but 2+declined at elevated initial Mn concentrations due to active site saturation.The process was spontaneous 2 and endothermic,with the Langmuir isotherm model(R=0.994)and pseudo-second-order kinetic model 2(R=0.996)providing the best fit to experimental data.Mechanistic analysis indicated that chemisorption,2+primarily through ion exchange and inner-sphere complexation,was the dominant mode of Mn uptake.3+The presence of competing cations,especially Fe and Cu2+,2+significantly hindered Mn removal due to preferential binding.Importantly,BC exhibited strong reusability,maintaining over 80%removal effi-ciency across four adsorption–desorption cycles without evidence of secondary pollutants.These findings demonstrate the potential of natural BC as an efficient,reusable,and environmentally benign material for treating manganese-contaminated groundwater.展开更多
By encapsulating nanoscale particles of goethite(α-FeO(OH)),hydrous ceric oxide(CeO_(2)·H_(2)O,HCO)and silver nanoparticles(AgNPs)in the pores of polystyrene anion exchanger D201,a novel nanocomposite FeO(OH)-HC...By encapsulating nanoscale particles of goethite(α-FeO(OH)),hydrous ceric oxide(CeO_(2)·H_(2)O,HCO)and silver nanoparticles(AgNPs)in the pores of polystyrene anion exchanger D201,a novel nanocomposite FeO(OH)-HCO-Ag-D201 was prepared for the effective removal of arsenic from water.The isotherm study shows that FeO(OH)-HCO-Ag-D201 has excellent adsorption performance for As(III)and As(V),with an increased adsorption capacity of As(III)to 40.12 mg/g compared to that of 22.03 mg/g by the composite adsorbent without AgNPs(FeO(OH)-HCO-D201).The adsorption kinetics data showed that the sorption rate of FeO(OH)-HCO-Ag-D201 for As(III)is less than that for As(V),and the adsorption of As(III)and As(V)were consistent with the pseudo-second-order model and the pseudofirst-order model,respectively.Neutral or basic conditions are favored for the adsorption of As(III/V)by FeO(OH)-HCO-Ag-D201.Compared with nitrate/chloride/bicarbonate,sulfate/silicate/phosphate showed more remarkable inhibition of arsenic removal by FeO(OH)-HCO-Ag-D201,whereas natural organic matter showed no interference to the arsenic removal.The As(V)adsorption involved different interactions such as electrostatic attraction and surface complexation,while the adsorption of As(III)involved the part oxidization of As(III)to As(V)and the simultaneous adsorption of As(III)and As(V).In addition to the Ce(IV)in CeO_(2)·H_(2)O acted as an oxidant,the synergistic effect ofα-FeO(OH)and AgNPs also contributed to the oxidization of As(III)to As(V).Moreover,the reusable property suggested that this FeO(OH)-HCO-Ag-D201 nanocomposite has great potential for arsenic-contaminated water purification.展开更多
FT IR, Raman microscopy, XRD, 29 Si and 27 Al MAS NMR, were used to investigate changes in surface properties of a natural illite sample after acid base potentiometric titration. The characteristic ...FT IR, Raman microscopy, XRD, 29 Si and 27 Al MAS NMR, were used to investigate changes in surface properties of a natural illite sample after acid base potentiometric titration. The characteristic XRD lines indicated the presence of surface Al Si complexes, preferable to Al(OH) 3 precipitates. In the microscopic Raman spectra, the vibration peaks of Si O and Al O bonds diminished as a result of treatment with acid, then increased after hydroxide back titration. The varied ratio of signal intensity between IV Al and VI Al species in 27 Al MAS NMR spectra, together with the stable BET surface area after acidimetric titration, suggested that edge faces and basal planes in the layer structure of illite participated in dissolution of structural components. The combined spectroscopic evidence demonstrated that the reactions between illite surfaces and acid leaching silicic acid and aluminum ions should be considered in the model description of surface acid base properties of the aqueous illite.展开更多
基金National Natural Science Foundation of China(NSFC,No.11475008)。
文摘During the chemical weathering of the uranium mill tailings,released uranium could be immobilized by the newly formed secondary minerals such as oxyhydroxides.A deeper understanding of the interaction between uranium and common oxyhydroxides under environmental conditions is necessary.In this work,uranium sorption behaviors on Al-,Mn-and Fe-oxyhydroxide minerals(boehmite,manganite,goethite,and lepidocrocite)were investigated by batch experiments.Results showed that the uranium sorption on Al-oxyhydroxide behaved significantly differently from the other three minerals.The sorption edge of the Mn-and Fe-oxyhydroxides located around pH 5,while the sorption edge of boehmite shifted about 1.5 pH unit to near neutral.The sorption isotherms of uranium on manganite,goethite and lepidocrocite at pH 5.0 could be well fitted by the Langmuir model.Instead of surface complexation,sorption on boehmite happened mainly by uranium-bearing carbonates and hydroxides precipitation as illustrated by the characterization results.Both carbonate and phosphate strongly affected the uranium sorption behavior.The removal efficiency of uranium by boehmite exceeded 98%after three sorption-desorption cycles,indicating it may be a potential material for uranium removal and recovery.
文摘The complexation of phosphates in the quartz-metal ion-H_2O-oleate system was studied. Computer assisted calculations with the aid of the advanced program SOLGASWATER and known equilibrium constants were used to evaluate the mechanism,The calculation results revealed that in the presence of a certain amount of phosphates, metal ions adsorbed at the quartz-H_2O interface will be transferred into solution.Thus the competi- tion for metal ions between phosphates and the quartz surface leads to surface deactivation and re- duced floatability.Various distribution diagrams clearly demonstrate the change of surface complexation as a function of added phosphate concentration.The deactivation products were also evaluated.
文摘The immobilisation of radionuclides in groundwater environments cannot be explained solely by the empirical models.These empirical models are not sen-sitive to the varying conditions that are found in nature.Sorption has been shown to be very sensitive to pH,Eh and ionic strength of the solution in which the radionuclides are found.Batch sorption experiments at different ionic strengths were conducted and LogK constants for the sorption processes were determined.JChess Geochemical code was used to compare experimentally and predicted Log K constants obtained from surface complexation reactions with different granitic rock samples.For pH dependent sorption,1×10^(-5) mol·dm^(-3) solutions of NiCl_(2) were prepared,and the pH was adjusted from 4 to 11,with intervals of 0.6 to 0.8 on the pH scale using NaOH(aq)and HCl(aq).Different concentrations of pH adjusting solutions were made from very weak to very strong acid or base.Sample separation was performed and counting was performed for Ni using the scintillation counter.Packard TRI-CARB 2750 TR/LL Liquid Scintillation Counter:Used for Ni sorption studies,counting from 0 to 67 keV to 2σ.Results showed varying sorption properties from one granitic mineral to the other.There was no effect of ionic strength on the sorp-tion of Ni to Muscovite Mica(MM).Varying pH sorption isotherms for Ni sorption to Orthoclase Feldspar,showed experimental data and modelled matched for monodentate and bi dentate sorption using the same experimental conditions,modelling done assuming mono and bidentate complex formation.The following conclusions can be made after studying varying pH sorption profiles of selected granitic rocks and mineral in different NaCl concentrations,using different models.Ni sorption is suppressed in the presence of NaCl,due to competition for the sorption sites.
基金Projects(51775445,52175435)supported by the National Natural Science Foundation of ChinaProject(CX2023051)supported by the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China。
文摘On-machine measurement(OMM)stands out as a pivotal technology in complex curved surface adaptive machining.However,the complex structure inherent in workpieces poses a significant challenge as the stylus orientation frequently shifts during the measurement process.Consequently,a substantial amount of time is allocated to calibrating pre-travel error and probe movement.Furthermore,the frequent movement of machine tools also increases the influence of machine errors.To enhance both accuracy and efficiency,an optimization strategy for the OMM process is proposed.Based on the kinematic chain of the machine tools,the relationship between the angle combination of rotary axes,the stylus orientation,and the calibration position of pre-travel error is disclosed.Additionally,an OMM efficiency optimization model for complex curved surfaces is developed.This model is solved to produce the optimal efficiency angle combinations for each to-be-measured point.Within each angle combination,the effects of positioning errors on measurement results are addressed by coordinate system offset and measurement result compensation method.Finally,the experiments on an impeller are used to demonstrate the practical utility of the proposed method.
基金supported by the National 863 Program of China(Grant No.2007AA060502)the National 973 Program of China(Grant No.2007CB209605)the Graduate Student Innovation Fund of China University of Petroleum(EastChina)(Grant No.S2010-1).
文摘In areas with a complex surface,the acquisition and processing of seismic data is a great challenge.Although elevation-static corrections can be used to eliminate the influences of topography,the distortions of seismic wavefields caused by simple vertical time shifts still greatly degrade the quality of the migrated images.Ray-based migration methods which can extrapolate and image the wavefields directly from the rugged topography are efficient ways to solve the problems mentioned above.In this paper,we carry out a study of prestack Gaussian beam depth migration under complex surface conditions.We modify the slant stack formula in order to contain the information of surface elevations and get an improved method with more accuracy by compositing local plane-wave components directly from the complex surface.First,we introduce the basic rules and computational procedures of conventional Gaussian beam migration.Then,we give the original method of Gaussian beam migration under complex surface conditions and an improved method in this paper.Finally,we validate the effectiveness of the improved method with trials of model and real data.
基金Progress of Projects Supported by NSFCsupported by the National Basic Research Program of China (2011CB933700)the National Natural Science Foundation of China (20907055,20971126,21071147,91126020,21077107)
文摘The interaction between radionuclides and solid/water interfaces is important to understand the physicochemical processes of radionuclides in the natural environment.Herein,the interaction of 60Co(Ⅱ) with TiO 2 in aqueous solution as a function of pH and ionic strength was studied by using batch technique combined with surface complexation model and density functional theory(DFT) calculations.The batch experimental results showed that the adsorption of 60Co(Ⅱ) was dependent on pH and independent of ionic strength,indicating the formation of inner-sphere surface complexes on TiO 2 surfaces.The results of surface complexation models and DFT calculations indicated that the surface species of 60Co(Ⅱ) adsorbed on TiO 2 followed the trend:B structure(i.e.,60Co(Ⅱ) was linked to one bridge oxygen site) was the dominant surface species at low pH,and TT structure(i.e.,60Co(Ⅱ) was linked to two terminal oxygen sites) became the important surface complex at neutral and alkaline pH values.These results demonstrated that a multi-technique approach could lead to definitive information on the structures of adsorbed 60Co(Ⅱ) at the molecular level at the TiO 2 /water interfaces,as well as realistic models to rationalize and accurately evaluate the macroscopic manifestations of radionuclide adsorption phenomena.
基金Acknowledgements The authors would like m thank the anonymous reviewers for providing comments to improve the quality of this paper, and iSPACE of Research Studios Austria FG （RSA） （http：//ispace.researchstudio. at/） for providing the ALS datasets. The study described in this paper is funded by the National Natural Science Foundation of China （Grant No. 41301493）, the High Resolution Earth Observation Science Foundation of China （GFZX04060103-5-17）, and Special Fund for Surveying and Mapping Scientific Research in the Public Interest （201412007）.
文摘Airborne laser scanning （ALS） is a technique used to obtain Digital Surface Models （DSM） and Digital Terrain Models （DTM） efficiently, and filtering is the key procedure used to derive DTM from point clouds. Generating seed points is an initial step for most filtering algorithms, whereas existing algorithms usually define a regular window size to generate seed points. This may lead to an inadequate density of seed points, and further introduce error type I, especially in steep terrain and forested areas. In this study, we propose the use of object- based analysis to derive surface complexity information from ALS datasets, which can then be used to improve seed point generation. We assume that an area is complex if it is composed of many small objects, with no buildings within the area. Using these assumptions, we propose and implement a new segmentation algorithm based on a grid index, which we call the Edge and Slope Restricted Region Growing （ESRGG） algorithm. Surface complexity information is obtained by statistical analysis of the number of objects derived by segmentation in each area. Then, for complex areas, a smaller window size is defined to generate seed points. Experimental results show that the proposed algorithm could greatly improve the filtering results in complex areas, especially in steep terrain and forested areas.
基金The authors acknowledge support from the National Nat-ural Science Foundation of China(51635007,51925503,51705179)Natural Science Foundation of Hubei Province of China(2020CFA028).
文摘Large,3D curved electronics are a trend of the microelectronic industry due to their unique ability to conformally coexist with complex surfaces while retaining the electronic functions of 2D planar integrated circuit technologies.However,these curved electronics present great challenges to the fabrication processes.Here,we propose a reconfigurable,mask-free,conformal fabrication strategy with a robot-like system,called robotized‘transfer-and-jet’printing,to assemble diverse electronic devices on complex surfaces.This novel method is a ground-breaking advance with the unique capability to integrate rigid chips,flexible electronics,and conformal circuits on complex surfaces.Critically,each process,including transfer printing,inkjet printing,and plasma treating,are mask-free,digitalized,and programmable.The robotization techniques,including measurement,surface reconstruction and localization,and path programming,break through the fundamental constraints of 2D planar microfabrication in the context of geometric shape and size.The transfer printing begins with the laser lift-off of rigid chips or flexible electronics from donor substrates,which are then transferred onto a curved surface via a dexterous robotic palm.Then the robotic electrohydrodynamic printing directly writes submicrometer structures on the curved surface.Their permutation and combination allow versatile conformal microfabrication.Finally,robotized hybrid printing is utilized to successfully fabricate a conformal heater and antenna on a spherical surface and a flexible smart sensing skin on a winged model,where the curved circuit,flexible capacitive and piezoelectric sensor arrays,and rigid digital–analog conversion chips are assembled.Robotized hybrid printing is an innovative printing technology,enabling additive,noncontact and digital microfabrication for 3D curved electronics.
基金National Natural Science Foundation of China （51075013） Beijing Natural Science Foundation （4102035）+1 种基金 Fundamental Research Funds for the Central Universities （YWF-10-01-A09） Research Foundation of State Key Laboratory for Manufacturing Systems Engineering （Xi＇an Jiaotong University）
文摘To improve the grinding quality of robotic belt grinding systems for the workpieces with complex shaped surfaces, new concepts of the dexterity grinding point and the dexterity grinding space are proposed and their mathematical descriptions are defined. Factors influencing the dexterity grinding space are analyzed. And a method to determine the necessary dexterity grinding space is suggested. Based on particle swarm optimization （PSO） method, a strategy to optimize the grinding robot structural dimensions and position with respect to the grinding wheel is put forward to obtain the necessary dexterity grinding space. Finally, to grind an aerial engine blade, a dedicated PPPRRR （P： prismatic R： rotary） grinding robot structural dimensions and position with respect to the grinding wheel are optimized using the above strategy. According to simulation results, if the blade is placed within the dexterity grinding space, only one gripper and one grinding machine are needed to grind its complex shaped surfaces.
文摘Taking AutoCAD2000 as platform, an algorithm for the reconstruction ofsurface from scattered data points based on VBA is presented. With this core technology customerscan be free from traditional AutoCAD as an electronic board and begin to create actual presentationof real-world objects. VBA is not only a very powerful tool of development, but with very simplesyntax. Associating with those solids, objects and commands of AutoCAD 2000, VBA notably simplifiesprevious complex algorithms, graphical presentations and processing, etc. Meanwhile, it can avoidappearance of complex data structure and data format in reverse design with other modeling software.Applying VBA to reverse engineering can greatly improve modeling efficiency and facilitate surfacereconstruction.
基金supported by the financial support of Natural Science Research Program of Jiangsu Education Department(No.13KJB310014)Natural Science Foundation of Jiangsu Province(BK20140429)the Natural Science Foundation of Nantong University(No.14ZY015,No.13R23)
文摘The aim of this study was to investigate the inhibitory effect of heparin/fibronectin （Hep/Fn） complexes on neointimal hyperplasia following endovascular intervention. Hep/Fn complexes were immobilized onto titanium （Ti） surfaces, with subsequent X-ray photoelectron spectroscopy （XPS）, Toluidine Blue 0 （TBO） and immunohistochemistry methods were used to characterize surface properties. Smooth muscle cell （SMC） cultures were used to evaluate the effect of Hep/Fn complexes on SMC proliferation. Results showed that Hep/Fn complexes successfully immobilized onto Ti surfaces and resulted in an inhibition of SMC proliferation. This study suggests that Hep/Fn surface-immobilized biomaterials develop as a new generation of biomaterials to prevent neointimal hyperplasia, particularly for use in cardiovascular implants.
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.
文摘Aimed at inner quality controlling for complex surface parts, an ultrasonic testing system for complex surface parts has been developed using ultrasonic NDT(Non-destructive Testing)which has features of strong penetration, well direction, high sensitivity, low cost, and harmless to people and material. The technologies of the computer, NC (Numerical control), precision mechanism, signal analysis and processing were integrated in the testing system. The system includes a PC, system software, ultrasonic data acquisition card, stepper motor drive card and five-axis precision mechanical device, etc. The software was developed using WIN98-based VC++. According to CAD data of the parts and interpolation methods, the scanning programs can be programmed. The five-axis scanning system is driven by the CNC(computer numerical control) system to control the attitude of ultrasonic probes. The system’s automatic scanning for complex surface parts, real-time acquiring ultrasonic data and automatic identifying flaw signal have been realized. This system can be used not only for testing complex surface parts, but for testing random curve parts. With fast testing speed, high sensitivity, high testing precision and high reliability, the system has a wide adaptability.
文摘Parts of complex surface are widely used now in many fields, and their detection has caused much concern. In China many manufactories still carry on the traditional way of manual detection, which requires highly skilled personnel and efficiency is low. Some large manufactories have imported auto-detecting equipments, which require CAD data on the parts, or just divide the surface into several approximate planes for automatic detection. Phased-array system is seldom used, and the cost is high. Besides, most of the systems have not considered the automatic sensitivity compensation of parts with varying thickness. To improve the detection quality and efficiency of nondestructive test (NDT) of parts of complex surface, this paper puts forward an integrated ultrasonic NDT system characterized by: (1) Use of ultrasonic measurement and reverse of curved surface to solve the CAD data problem; (2) Use of an automatic sensitivity compensation algorithm (based on the part’s modelling information obtained in surface reverse) to fit the variety of the thickness; (3) Use of template matching and pseudo-color imaging to improve the quality of detection results. The system features integration of low cost mature technologies, and is suitable for detection of various parts of different complex surfaces in medium-and-small enterprises. The test results showed that the system can automatically detect parts of complex surface successfully, and that the inspection result is good and reliable.
基金supported by the national project "Geophysical Complex Technologies for Reservoirs and Unconventional Gas Reservoirs"(No.2017 ZX05018-004-003)
文摘Walkaway VSP cannot obtain accurate velocity field,as it asymmetrically reflects ray path and provides uneven coverage to underground target,thereby presenting issues related to imaging quality.In this study,we propose combining traveltime tomography and prestack depth migration for VSP of an angle-domain walkaway,in a bid to establish accurate two-dimensional and three-dimensional(3 D)velocity models.First,residual curvature was defined to update velocity,and an accurate velocity field was established.To establish a high-precision velocity model,we deduced the relationship between the residual depth and traveltime of common imaging gathers(CIGs)in walkaway VSP.Solving renewal velocity using the least squares method,a four-parameter tomographic inversion equation was derived comprising formation dip angle,incidence angle,residual depth,and sensitivity matrix.In the angle domain,the reflected wave was divided into up-and down-transmitted waves and their traveltimes were calculated.The systematic cumulative method was employed in prestack depth migration of a complex surface.Through prestack depth migration,the offset-domain CIGs were obtained,and dip angle was established by defining the stack section horizon.Runge–Kutta ray tracing was employed to calculate the ray path from the reflection point to the detection point,to determine the incident angle,and to subsequently calculate the ray path from the reflection point to the irregular surface.The offset-domain residual depths were mapped to the angle domain,and a new tomographic equation was established and solved.Application in the double complex area of the Tarim Basin showed the four-parameter tomographic inversion equation derived in this paper to be both correct and practical and that the migration algorithm was able to adapt to the complex surface.
基金The project surported by State"863"PlanNational Natural science fund.
文摘A novel method for preparing metalllzed film has been studied.The reduction process and properties of the poly(vinyl alcohol)(PVA)were probed by several analytic means.According to the etudies,a mechanism for the polymer surface reduction metallization was proposed and proved.
基金Project supported by Project 4-“Research and Application of Key Geophysical Technologies of Carbonate Rocks in Sichuan Basin”(No.:2016E-06-04)under the Major Science and Technology Special Project of PetroChina Company Limited“Research and Application of Key Technologies for Natural Gas Production of 30 Billion Cubic Meters in Southwest Oil and Gas Field”.
文摘The earth surface in the Sichuan Basin and its periphery is geologically complex,which causes low signal-to-noise ratio of seismic data,poor imaging quality of seismic profiles and great difficulty in data acquisition.In order to ensure high-quality operation of the seismic survey project in the complex surface of the Sichuan Basin,researchers have been working continuously to solve the bottleneck problems in the seismic acquisition technology for complex surface in recent years.In addition,the upgrading of acquisition technology and operation capacity is promoted effectively by means of technical innovation,and a series of key technologies for seismic acquisition are developed.And the following application results of this series of technologies are obtained.First,the optimization design technology of the geometry based on wave equation forward modeling and actual data,combined with prestack migration imaging can show the influence of different acquisition schemes on the prestack imaging effect of complex targets more directly,which makes the seismic acquisition scheme more economic and effective.Second,by extracting landform risks and surface obstacle information intelligently,combined with field fine reconnaissance,landform risk identification and hierarchical evaluation and indoors intelligent optimization of well-shot physical point deployment are conducted,and thus the GISt intelligent deployment technology of shot point in complex surface is formed,which effectively reduces the risks of operation.Third,the cavity excitation technology which reduces the initial pressure of explosive pulse and extends the explosive action time of explosives can increase the conversion rate of rock excitation energy into effective elastic wave energy and the reflected energy and improve the quality of seismic single shot data.Fourth,combination of the automatic evaluation technology for field seismic data acquired in mountainous regions and the KL-GMLiveQC1.0 software can improve the evaluation efficiency,reduce the evaluation cost and ensure the high-quality acquisition of seismic data in complex surface.In conclusion,this series of key seismic acquisition technologies greatly improve the signal-to-noise ratio and resolution of seismic data,lay a foundation for fine reservoir prediction,and ensure the continuous important breakthrough of three-dimensional natural gas exploration and development in the gas fields of marine carbonate rock,shale gas,volcanic rock and shallow tight sandstone gas in the Sichuan Basin.
文摘This study investigates the potential of natural Brown Coal(BC)as a sustainable,cost-effective adsorbent for the removal of manganese(Mn2+)from contaminated groundwater.A series of batch adsorp-tion experiments was conducted to assess the influence of key operational parameters—such as solution pH,2+initial Mn concentration,BC dosage,temperature,and the presence of competing ions—on 2+Mn removal efficiency.The environmental compatibility and regeneration potential of BC were also evaluated to deter-mine its practical viability for repeated use.To better understand the adsorption behaviour,equilibrium and kinetic data were analysed using established isotherm and kinetic models,while thermodynamic parameters were computed to assess the spontaneity and thermal characteristics of the adsorption process.Furthermore,geochemical modelling and comprehensive BC characterization—including surface morphology,miner-alogical and elemental composition,and functional group analysis—were 2+performed to elucidate Mn speciation under varying environmental conditions and to uncover the underlying adsorption mechanisms.2+Results showed that Mn removal efficiency increased with higher pH,temperature,and BC dosage,but 2+declined at elevated initial Mn concentrations due to active site saturation.The process was spontaneous 2 and endothermic,with the Langmuir isotherm model(R=0.994)and pseudo-second-order kinetic model 2(R=0.996)providing the best fit to experimental data.Mechanistic analysis indicated that chemisorption,2+primarily through ion exchange and inner-sphere complexation,was the dominant mode of Mn uptake.3+The presence of competing cations,especially Fe and Cu2+,2+significantly hindered Mn removal due to preferential binding.Importantly,BC exhibited strong reusability,maintaining over 80%removal effi-ciency across four adsorption–desorption cycles without evidence of secondary pollutants.These findings demonstrate the potential of natural BC as an efficient,reusable,and environmentally benign material for treating manganese-contaminated groundwater.
基金supported by the National Key Research and Development Program of China(No.2022YFA1205601).
文摘By encapsulating nanoscale particles of goethite(α-FeO(OH)),hydrous ceric oxide(CeO_(2)·H_(2)O,HCO)and silver nanoparticles(AgNPs)in the pores of polystyrene anion exchanger D201,a novel nanocomposite FeO(OH)-HCO-Ag-D201 was prepared for the effective removal of arsenic from water.The isotherm study shows that FeO(OH)-HCO-Ag-D201 has excellent adsorption performance for As(III)and As(V),with an increased adsorption capacity of As(III)to 40.12 mg/g compared to that of 22.03 mg/g by the composite adsorbent without AgNPs(FeO(OH)-HCO-D201).The adsorption kinetics data showed that the sorption rate of FeO(OH)-HCO-Ag-D201 for As(III)is less than that for As(V),and the adsorption of As(III)and As(V)were consistent with the pseudo-second-order model and the pseudofirst-order model,respectively.Neutral or basic conditions are favored for the adsorption of As(III/V)by FeO(OH)-HCO-Ag-D201.Compared with nitrate/chloride/bicarbonate,sulfate/silicate/phosphate showed more remarkable inhibition of arsenic removal by FeO(OH)-HCO-Ag-D201,whereas natural organic matter showed no interference to the arsenic removal.The As(V)adsorption involved different interactions such as electrostatic attraction and surface complexation,while the adsorption of As(III)involved the part oxidization of As(III)to As(V)and the simultaneous adsorption of As(III)and As(V).In addition to the Ce(IV)in CeO_(2)·H_(2)O acted as an oxidant,the synergistic effect ofα-FeO(OH)and AgNPs also contributed to the oxidization of As(III)to As(V).Moreover,the reusable property suggested that this FeO(OH)-HCO-Ag-D201 nanocomposite has great potential for arsenic-contaminated water purification.
文摘FT IR, Raman microscopy, XRD, 29 Si and 27 Al MAS NMR, were used to investigate changes in surface properties of a natural illite sample after acid base potentiometric titration. The characteristic XRD lines indicated the presence of surface Al Si complexes, preferable to Al(OH) 3 precipitates. In the microscopic Raman spectra, the vibration peaks of Si O and Al O bonds diminished as a result of treatment with acid, then increased after hydroxide back titration. The varied ratio of signal intensity between IV Al and VI Al species in 27 Al MAS NMR spectra, together with the stable BET surface area after acidimetric titration, suggested that edge faces and basal planes in the layer structure of illite participated in dissolution of structural components. The combined spectroscopic evidence demonstrated that the reactions between illite surfaces and acid leaching silicic acid and aluminum ions should be considered in the model description of surface acid base properties of the aqueous illite.
