A water-absorbent resin was prepared using a corn starch/acrylic acid/N,N'-methylene bisacrylamide ternary blend system through radiation crosslinking with a 10 MeV electron accelerator. The structure and thermal stability of the resin were characterized using infrared spectroscopy and thermogravimetric analysis. The relationships between water or saline water absorbency of absorbent and its particle size, the neutralization degree of acrylic acid, and the absorbed doses were investigated. Additionally, the water absorption capability, water retention rate, and degradation rate of the resin in soil were determined. The results demonstrated that a starch-based crosslinked resin was successfully prepared through electron beam radiation polymerization, exhibiting excellent thermal stability and water absorption properties. When the neutralization degree of acrylic acid was 80% and the absorbed dose was 10 kGy, the water absorbency, saline water absorbency, and soil water absorbency of the resin with a particle size of 150-180 μm were 204.4 g/g, 35.9 g/g, and 45.0 g/g, respectively. The water retention rate of soil with added absorbent resin reached 20.7% after one month, representing an improvement by a factor of 2.5 compared to pure water. The degradation rate of the water-absorbent resin can reached 67.2% after four months, indicating a low environmental impact. This study applied radiation processing technology to the design and development of natural polymer-based functional materials, providing theoretical and practical references for preparing starch-based water-absorbent resins using electron beam irradiation.

Radioactive aerosols (polonium and polonium compounds) generated during the normal operation of lead-bismuth coolants are extremely toxic and radioactive, thus rendering them detrimental to the operation staff and environment. Thus, radioactive polonium aerosols generated during polonium removal must be captured and immobilized. In this study, an aerosol fixative with desirable wettability and capture fixation properties was prepared using compounding xanthan gum (XG) with a grafted polymer polyacrylamide grafted acrylic acid, 2-hydroxyethyl acrylate (PAM-g-PAA/PHEA), and a polyacrylamide-based material was used for the substrate. The structure of the aerosol fixative was analyzed and confirmed via infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The thermal properties, wettability, as well as capture and fixation effects of tellurium (simulated polonium) aerosols were investigated via thermogravimetric analysis, contact-angle measurements, and fixed-sedimentation experiments. The results showed that PAM-g-PAA/PHEA and XG synergistically formed a dual-network structure through hydrogen bonding and that the thermal, wettability, and immobilization properties of the aerosol fixative improved. The optimal addition amount of XG was determined to be 0.05% based on the results of sedimentation experiments, wettability, and fixation rate. At this optimal amount, the aerosol fixing agent exerts the greatest effect on the hydrogen bond and van der Waals forces of tellurium powder. The lowest contact angle is 38.38°, and the tellurium powder infiltrated completely within 80 s. Based on the mass-concentration change, the sedimentation fixation rate is 99.24%, which indicates that atomization fixation is suitable for capturing and fixing radioactive aerosols. The small droplets atomized by the aerosol fixing agent in this study rapidly deposited aerosols, followed by continuous capture and fixation. The results of batch fixed sedimentation verify that this type of aerosol fixing agent is suitable for the capture and fixation of tellurium aerosols, thus providing technical support for the capture and fixation of radioactive polonium aerosols.

To develop an efficient antibacterial coating material, the basic formulas for epoxy acrylate 6215-100 and triepropanediol diacrylate are derived using silicone quaternary ammonium salt (QAC) as an antibacterial agent and fluorine-containing acrylate as a hydrophobic monomer. Different ultraviolet (UV)-photocuring formulations are established based on different proportions of antibacterial agents and hydrophobic monomers. The surface morphology, double-bond transformation, thermal stability, mechanical properties, and antibacterial properties of coatings containing different proportions of additives are investigated. The results showed that the higher the QAC content in the coating, the better was the antibacterial effect. Moreover, the antibacterial-zone diameter of the coating reached 4.05 mm when 25% 1UV-F:9QAC was added. The double-bond conversion rate of all samples exceeded 80%. The mechanical properties deteriorated with the increase in the additives. The maximum water contact angle of the 1UV-F:9QAC coating was 91.1°. The 3UV-F:7QAC additive demonstrated the best comprehensive performance when the additive amount was 15%; it exhibited a bacteriostatic range of 1.3 mm against Staphylococcus aureus, a maximum tensile strength of 3.06 MPa, and an elongation at break of 44.0%. The coating exhibited a double-bond conversion rate exceeding 90%, and its thermal stability did not degrade significantly.

In national defense, aerospace, and nuclear power fields, the service environments of polymer materials in equipment are complex and necessitate high requirements for their radiation resistance and thermal stability. Therefore, studying the aging behavior of polymer materials in a coupled radiation-thermal environment is crucial. In this study, F2311 rubber material was subjected to aging tests in the temperature range of 36-70 °C, with an absorbed γ dose of 20 kGy, 100 kGy, 200 kGy. The effects of the coupled temperature and absorbed dose on the mechanical properties of F2311 were investigated. The gaseous products released by the F2311 material and their kinetic laws were determined using gas-phase infrared spectra. The experimental results showed that the mechanical properties of the F2311 elastomer deteriorated rapidly in the radiation-thermal environment. Radiolytic outgassing was inevitable, and the gaseous products included corrosive halogen hydrides. Gas-phase infrared spectroscopy can quickly identify and quantitatively analyze gaseous products to trace and supervise the service reliability of equipment. This study is expected to provide a basis for the study of coupled multifactor aging and compatibility of fluorine rubber.

Stator bars are crucial components in motor production. The traditional process used for curing the surface paint of stator bars has a long cycle, low efficiency, and high energy consumption. Infrared radiation curing is a method that can potentially overcome these issues. This study investigated the curing behaviors of three types of paints (low-resistance, high-resistance, and red enamel paints) on the surfaces of stator bars under infrared radiation. The paint samples were prepared using an epoxy glass cloth plate as the substrate material and a silicon carbide infrared radiation plate as the infrared radiation source. The cured paint was characterized via infrared spectroscopy and scanning electron microscopy. The degree of curing and the electrical properties of each sample were measured and compared with those obtained using the traditional curing process. The results indicated that the degree of curing of the three types of paints after curing by infrared radiation was higher than that under the traditional curing process by 8.98%, 10.33%, and 10.40%, respectively, and that the surface drying effect could be achieved in 2 min. The electrical properties and surface morphologies of the paints were shown to satisfy the standard performance requirements. The paints cured by infrared radiation exhibited good electrical properties. The study thus demonstrated the high efficiency and practicability of the infrared radiation curing method, as well as its wide potential applicability.

The long-term, slow reaction that occurs when polyethylene (PE) is exposed to oxygen after ionizing radiation is known as post-radiation oxidation, which significantly affects the long-term performance of radiation-modified PE materials. In this study, an ultrahigh molecular weight polyethylene (UHMWPE) film, a high-density polyethylene (HDPE) film, and a low-density polyethylene (LDPE) film were selected as typical PE materials and irradiated with γ-rays. Subsequently, the carbonyl products of the post-radiation slow oxidation reaction were quantitatively analyzed using Fourier transform infrared spectroscopy and by varying the temperature, oxygen partial pressure, and absorbed dose. The effects of these factors on the oxidation behavior of PE after radiation were systematically investigated. Post-radiation oxidation was clearly observed in the UHMWPE and HDPE films. Meanwhile, the LDPE film showed weak post-radiation oxidation, which could be maintained for a long time at room temperature, with the highest reaction rate occurring at 50 °C. However, above 70 °C, the oxidation reaction could only be maintained for a few hours. Additionally, a significant positive correlation was observed among the post-radiation oxidation reaction, oxygen partial pressure, and absorbed dose. This study not only offers a new perspective for understanding the post-radiation oxidation reaction of PE but also provides guidance for improving the accelerated-aging evaluation of radiation-modified PE materials.

The strong fluorescence of 7-hydroxycoumarin yielded by the reaction of coumarin with hydroxyl radicals (?OH) was used as a fluorescent probe to determine the yield of 7-hydroxycoumarin aqueous solutions with different concentrations of TBP and TiAP after gamma ray irradiation. The reaction rate constants of TBP and TiAP with ?OH at room temperature were determined via pseudo-first order kinetic fitting (kTBP= (9.0 ± 0.2) ×109 L/（mol·s）and kTiAP= (5.3 ± 0.2) ×109 L/（mol·s）),respectively. Owing to the stronger hydrophobicity of TiAP compared with that of TBP,its reaction rate constant with ?OH is lower than that of TBP,thus resulting in a higher yield of ?OH in the TiAP solution compared to the TBP solution with the same concentration. This study provides a simple,convenient and efficient method for investigating the reactions between extractants and ?OH.

This study leverages the ability of polytetrafluoroethylene (PTFE) to generate stable free radicals under ionizing radiation to develop a solid PTFE dosimeter sheet. Experimental results indicate a strong positive correlation between free radical response and absorbed dose over a broad range (1-180 kGy). The performance of the dosimeter was minimally influenced by dose rate and energy dependence,while the effects of irradiation temperature and post-irradiation storage time on free-radical decay exhibited clear and consistent patterns. Unlike conventional dosimeters used in the industry,the PTFE dosimeter is suitable for high-dose measurements and calibrations,covering a range of 1-180 kGy with a total uncertainty of less than 5.02%,demonstrating high metrological reliability. This study provides valuable insights into precise dose control and calibration in the irradiation processing of polymers and other functional materials.

In the clinical practice of radiotherapy,how to quickly,safely,accurately and economically monitor the irradiation dose or implement quality assurance measures before irradiation has always been a research hotspot in this research field. In this study,the reaction between nitrate ions and free radicals produced by water radiolysis was innovatively used as a dose-response mechanism. A radiation-grafted silica gel acrylic composite was selected as a matrix material to develop a tough radiation composite hydrogel dosimeter with high mechanical strength. The experimental results showed that the hydrogel dosimeter exhibited the best dose-response linear correlation under a sodium nitrate concentration of 0.5 mol/L and sodium formate concentration of 2.5×10-3 mol/L. In addition,the prepared hydrogel dosimeter not only exhibited excellent puncture resistance,non-brittleness,high pressure resistance,and adjustable mechanical properties,but also displayed impressive time stability in practical applications,indicating potential for commercialization.

This study examines the changes in properties and aging mechanisms of polyphenylene oxide (PPO) foams under two densities when subjected to combined γ-radiation (0–1 kGy) and 3% compression. The investigation focuses on the effects of absorbed dose and compression on various characteristics,including the mechanical properties,thermal stability,thermal conductivity,surface morphology,and chemical structure of PPO foams. The types and yields of gases released during radiation exposure are revealed using gas-phase infrared spectroscopy. The results showed that the collapse and permanent deformation of the surface pore structure in PPO foams following γ radiation and compression aging significantly contribute to increase in elastic modulus and thermal conductivity. No significant changes were observed in the internal radicals or surface functional group structures of the samples before and after aging. The concentration of residual radicals within the samples was influenced by radiation-induced chemical changes and the absorbed dose. Upon radiation exposure and subsequent aging in an O2/N2 atmosphere,PPO foams emited CO2,CO,and alkanes. In addition,the CO2 yield of PPO foams after radiation-compression aging was slightly reduced due to the permanent deformation caused by compression,compared to γ-radiation aging alone. These findings hold significant value for the evaluation of γ-radiation–compression aging mechanisms and the lifespan of PPO foams.

To enhance the capacitive performance of supercapacitors,NiMoO4 electrode materials were synthesized by applying a molybdenum source to the nickel foam (NF) surface using irradiation technology. The morphology,microstructure,and electrochemical properties of the materials were optimized by varying the absorbed dose. The in situ synthesized NiMoO4 on an NF surface is an effective anode material for supercapacitors,demonstrating impressive energy storage capabilities. Its specific capacitance reaches 586.1 C/g at a current density of 1 A/g. It maintains a specific capacitance of 361.5 C/g at 15 A/g,resulting in a performance retention of 85.6%. Furthermore,the material retains a specific capacitance of 533.4 C/g with a capacity retention rate of 91.6% after 10 000 charge/discharge cycles,indicating strong cycling stability. The NiMoO4 electrode material was combined with activated carbon (AC) to create a hybrid supercapacitor,NiMoO4//AC. This device,operating at a maximum voltage of 1.7 V,exhibited a high energy density of 44.5 Wh/kg at a power density of 800.0 W/kg. The specific capacitance of the device remained at 93.2% after 5 000 charge/discharge cycles at a current density of 10 A/g. This study demonstrated that NiMoO4 electrode materials,prepared via irradiation,possess excellent electrochemical properties and significant application potential,offering a novel approach for designing high-efficiency,low-cost supercapacitor electrodes.

This article describes the preparation of continuous metal-organic framework (MOF) Zn(bdc)(dabco)?0.5 membranes on flexible polymer substrates using a radiation-induced method. The morphologies and structures of the membranes were investigated using X-ray diffraction,Fourier-transform infrared spectroscopy,and scanning electron microscopy. Their light hydrocarbon-adsorption properties were characterized using Brunauer-Emmett-Teller specific surface area measurements,density functional theory pore-size analysis,and single-component adsorption isotherms. The results indicated that the Zn(bdc)(dabco)0.5 membranes exhibited higher adsorption for ethane and propane than for methane. Moreover,the Zn(bdc)(dabco)0.5 membranes showed enhanced ethane/methane selectivity (reaching 11 at atmospheric pressure) and propane/methane selectivity (reaching 10 at atmospheric pressure). This study demonstrates the unique advantages of MOF membranes in the field of separation.

Temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) was grafted onto the surface of graphene oxide (GO) via reversible addition-fragmentation chain transfer polymerization initiated by γ-ray radiation. Raman spectroscopy and X-ray photoelectron spectroscopy analyses indicated that GO was reduced synchronously upon the radiation grafting polymerization of NIPAAm in an aqueous solution. A pulse radiolysis study demonstrated that NIPAAm reacted with both hydrated electrons (eaq-) and hydroxyl radicals (OH) produced by water radiolysis of which the reaction rate constants were 1.0×1010 L/(mol?s) and (4.3±0.2)×109 L/(mol?s),respectively. The addition reaction between NIPAAm and OH produces a radical at the unsaturated double bond of NIPAAm,which initiates the free radical polymerization of the monomers. Meanwhile,the reaction between NIPAAm and eaq- not only consumes strongly reductive eaq- but also produces weakly reductive radical anion intermediates,which decreases the reduction degree of rGO. The residual oxygen-containing groups on the surface of rGO with a low degree of reduction degree,such as carboxyl groups,endowed rGO-g-PNIPAAm with good pH responsiveness. Compared to pristine GO without PNIPAAm grafting,rGO-g-PNIPAAm which prepared with an absorbed dose of 3.6 kGy for radiation grafting polymerization exhibited a 30% higher photothermal conversion efficiency under near-infrared LASER irradiation. This study provides a convenient and controllable method for preparing photothermal conversion materials with pH and temperature dual responsiveness.

MXene/graphene oxide (GO) composites have broad application prospects in fields,such as energy,environment,and biomedicine. In this study,few-layer Ti3C2Tx was mixed with GO,which was then reduced and surface-modified using γ-ray radiation. Simultaneously,a composite hydrogel (M/rGO) was prepared by self-assembly from the interaction between the surface groups of reduced graphene oxide (rGO) and the oxygen-containing functional groups on the surface of Ti3C2Tx. The M/rGO-75 composite hydrogel prepared at an absorbed dose of 75 kGy exhibited a uniform three-dimensional network structure. The hydrogel was further freeze-dried and annealed to remove surface oxygen-containing functional groups and prepare a new composite aerogel (H-M/rGO),which maintained the original network structure. The prepared H-M/rGO electrode was used as a supercapacitor electrode. The optimized and synthesized H-M/rGO-75 composite aerogel exhibited a mass-specific capacitance of 119 F/g at a current density of 1 A/g,which was significantly higher than those of GO and aerogels without MXene. In addition,it exhibited excellent rate performance,conductivity,and cycling stability.

To enhance the radiation stability of silicone rubber (SR) and ensure its safe and reliable performance,hexagonal boron nitride (h-BN) was incorporated into SR as a functional filler. The effects of the filler amount and size on the mechanical properties,thermal stability,and radiation resistance of SR composites were investigated. The mechanism through which h-BN improved the radiation stability of SR was explored. The experimental results of stress-strain and hardness tests showed that the SR composite filled with 20 parts of h-BN (BN/SR-20) exhibited excellent mechanical properties. The tensile strength,100% constant tensile stress (S100),and hardness of BN/SR-20 improved by 5.9%,69.1%,and 15.6%,respectively,compared with those of unfilled SR (SR-U). BN/SR-20 displayed higher radiation resistance than SR-U,and its tensile strength and S100 were significantly better than those of SR-U in an ionizing-radiation environment. A larger transverse size of h-BN was found to be more effective in slowing down the radiation-aging process of SR. In addition,gas chromatography analysis of the radiolytic gas (hydrogen) yield and oxygen consumption of the composites and free-radical-scavenging experiments revealed that the addition of h-BN reduced the diffusion rate of O2 in SR and enhanced the radiation resistance of the composites.

Pre-oxidation is one of the key steps in the preparation of carbon fibers, and most of the defects generated in this process are inherited by the carbon fibers. Therefore, the structural optimization of polyacrylonitrile (PAN) pre-oxidized fibers is particularly important for enhancing the mechanical properties of carbon fibers. Irradiation is a modification method for optimizing the structure of pre-oxidized PAN fibers and effectively improving their mechanical properties. In this study, the microstructural evolution of high-dose electron beam irradiated PAN fibers during the pre-oxidation is investigated. Synchrotron radiation in situsmall angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) were used to characterize the heat treatment process of high-dose irradiated and unirradiated PAN fibers. Additionally, the characterization of PAN pre-oxidized fibers was analytically investigated by combining differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR).The results showed that high-dose irradiation (500 kGy) promoted the cross-linking and cyclization of the PAN fibers during heat treatment, thus effectively alleviating the intense exotherms caused by the cyclization and reducing the initial cyclization temperature. Additionally, high-dose irradiation significantly affected the molecular structure of the PAN fibers, whereas high-dose irradiation of the PAN fibers during the heat treatment reduced the transverse microporous (D) size, orientation angle (Beq), and crystal-layer spacing d002 to 7.61 nm, 8.58°, and 0.352 nm, respectively. In summary, high-dose irradiation improves the microstructure of the PAN fibers after heat treatment, which facilitates improvements to the structure and the properties of the corresponding carbon fibers.

This study focuses on the preparation of fabric-based flexible circuits using polyester fabric (PET) as a substrate via radiation curing and chemical copper plating methods. The microstructures, elemental distributions, durabilities, and stabilities of the flexible circuits were investigated. In this experiment, an industrial electron accelerator was utilized in conjunction with a steel plate "film" mold containing circuit structures to achieve selective irradiation by electron beams. Consequently, cured coating areas corresponding precisely to the designed circuit diagram (containing Ag/Fe3O4 catalyst) were formed on the fabric. Subsequently, metal layers were deposited in situ via chemical plating to construct fabric-based flexible circuits. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) results demonstrated that the fabricated flexible circuit exhibited a well-defined structure and a highly crystalline conductive copper layer. During a bending test comprising 15 000 cycles, the resistance change rate of the fabric-based flexible circuit remained below 16%, whereas during a temperature variation test ranging from 15 ℃ to 55 ℃, it remained below 5%. These results suggest that the circuit exhibits exceptional durability and stability. The fabrication method for fabric-based flexible circuits presented herin offers novel insights into the development of smart textile products.

Fiber absorbents are among the most economical materials for uranium extraction from seawater. Marine organisms are prone to fouling while being deployed in the sea, severely impairing the adsorption properties of the fiber. In this study, a novel antimicrobial adsorbent (UHMWPE-g-GEAO) was prepared by grafting guanidino and amidoxime groups onto ultra-high molecular weight polyethylene (UHMWPE) using radiation-induced graft polymerization technique. The guanidino groups endowed the fiber with excellent resistance to biofouling, enabling it to kill 99.9% of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). UHMWPE-g-GEAO fibers exhibited a fast uranium adsorption rate and high adsorption capacity, reaching 156.00 mg/g in aqueous solution and 1.39 mg/g in real seawater within 14 days. Additionally, the adsorbent exhibited superior reusability, preserving more than 94.5% of its adsorption efficiency and 96.2% of its desorption efficiency after five adsorption-desorption cycles. In this study, a reusable UHMWPE antimicrobial adsorbent fiber with promising potential for uranium extraction from seawater was developed.

Trichloroacetic acid is a common nonvolatile byproduct of drinking water disinfection and poses carcinogenic risks to the human body. In this study, four types of nano-oxide@microcrystalline-cellulose-based adsorbents (P25@microcrystalline cellulose, SiO?@microcrystalline cellulose (MCC-g-GMA@SiO2), Fe3O4@microcrystalline cellulose, and Fe2O3@microcrystalline cellulose) were successfully prepared by the pre-radiation grafting-embedding method. Subsequently, their ability to remove trichloroacetic acid from drinking water was investigated. The micro zonation morphology and surface properties of the materials were characterized and tested using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), Thermogravimetric (TG) analysis, and Scanning electron microscopy (SEM) characterization methods. The effects of monomer concentration, embedding concentration, and absorbed dose on the weight gain rate were systematically investigated. A complete static adsorption equilibrium curve was obtained on the basis of the results of adsorption experiments of four buried nano-oxides. The performance of SiO2@microcrystalline cellulose was found to be significantly higher than that of the other three adsorbents. When the volum percentage of monomer concentration was 30%, the mass percentage of embedding concentration was 4%, and the absorbed dose was 60 kGy, the removal rate of trichloroacetic acid in drinking water reached 83.27%. This series of adsorbent materials present significant potential for practical application in drinking water purification.

This study investigated the impact of low-dose electron beam irradiation on the structure-property correlation of linear low-density polyethylene (LLDPE), ternary copolymer polypropylene (co-PP), and their blends. Effects of the absorbed dose on the rheological properties, strength, crystallization behavior, crystal structure, and mechanical properties of LLDPE/co-PP blended polyolefins with various blending ratios were examined. The melt index test results indicate that, for LLDPE: co-PP ratios of 3∶1 and 1∶1, the melt index of each prepared polyolefin decreases and its crosslinking degree increases as the absorbed dose increases. However, for a LLDPE: co-PP ratio of 1∶3, the crosslinking degree of the polyolefin decreased with increasing absorbed dose. The crystal structure and crystallization behavior of the polyolefins were minimally affected by their absorbed doses, however, varying the ratios of blended LLDPE and co-PP affected the crystallization of both LLDPE and co-PP. For a blend with 1: 1 ratio, an absorbed dose greater than 2 kGy resulted in a sample elongation at break exceeding 890% and a fracture strength of 25.4 MPa those of both LLDPE and co-PP. Additionally, the stress-strain curves of the prepared polyolefins indicated that the absorbed dose enhanced the compatibility between LLDPE and co-PP. Thus, low-dose irradiation of LLDPE/co-PP polyolefins would offer a new avenue of research on polyolefin product development.

Fingerprints are an important trace material evidence for police to identify criminal. Cadmium sulfide quantum dots (CdS QDs) are fluorescent-labeled nanomaterials that can be used to improve the clarity and resolution of fingerprints. In this study, thioglycollic acid (TGA) was successfully modified to CdS QDs using the in-situ radiation reduction method, and synthetic TGA-CdS QDs were combined with polyvinyl acetate (PVAc) to form a TGA-CdS QDs/PVAc gel fingerprint film for fingerprint development. The structure and properties of the TGA-CdS QDs were characterized and tested using Fourier transform infrared (FTIR) spectroscopy, fluorescence spectrum, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The effects of temperature, concentration of TGA-CdS QDs, pH, and mass fraction of the PVAc gel fingerprint film on fingerprint development were investigated. The results showed that a combination of 6 mg/mL TGA-CdS QDs solution with 20% PVAc gel fingerprint film at room temperature (25 ℃) and pH of 9.0 resulted in the clearest, most complete, and high-resolution fingerprint patterns of fluorescence display. The carboxylic acid group formed by TGA-CdS QDs in an alkaline solution completely combined with the amino acids, proteins, fats, urea, and other components of the fingerprint residue attached to the PVAc gel film. Under ultraviolet irradiation, the fingerprint lines were clearly displayed in the form of fluorescence. The fingerprint display method can be effectively used in criminal investigation.