Energy Spectrum Analysis Research Articles

A simple synthesis of a core-shell structure PPy-Au nanocomposite for immunosensing of C-reactive protein

High-sensitivity C-reactive protein (hs-CRP) is an inflammatory biomarker and can accurately predict the development of cardiovascular disease (CVD). We synthesized a core-shell structure PPy-Au nanocomposite in situ by chemically oxidizing pyrrole (Py) with HAuCl4 and the produced Au nanoparticles realized the doping in the polymerization. Analysis of morphology and energy spectrum as well as electrochemical characterization confirmed the successful one-pot synthesis. The conductive polymers with porous structure provide abundant sites for anti-CRP binding and effectively enhanced the sensitivity of the label-free BSA/anti-CRP/PPy-Au/GCE immunosensor. Its analytical performance was observed using differential pulse voltammetry (DPV), with a linear range from 0.0005 to 60 μg mL−1 and a detection limit of 0.17 ng mL−1. The platform demonstrated satisfactory selectivity, stability, and reproducibility. To validate its clinical application, we detected CRP in human serum samples with a recovery rate of 101.00–105.95% and investigated the consistency of the developed method and immunoturbidimetry with a deviation between −1.2% and +3.2%, suggesting great potential for use in point-of-care testing (POCT).

CO2 corrosion prediction on 20# steel under the influence of corrosion product film

Based on corrosion thermodynamics and kinetics, considering the multi-field coupling effects of fluid flow, electrochemical reaction and mass transfer process, a new corrosion prediction mechanistic model was proposed by introducing the influence factor of corrosion product film on diffusion coefficient of ion mass transfer, which is based on the CO 2 corrosion prediction model proposed by Nesic et al. The influence of temperature, flow rate and pH value on CO 2 corrosion behavior on 20# steel was studied by orthogonal tests. Scanning electron microscopy (SEM) and energy spectrum analysis (EDS) was used to analyze the surface and cross section morphology of the corrosion product film, and the thickness of the corrosion product film was measured. The results show that the introduced influence factor can simplify the ion mass transfer calculation in the presence of corrosion product film, and the relative error between the predicted value of the modified model and the experimental results is satisfactorily controlled less than 10%. Compared with the prediction model without considering the influence of corrosion product film, the influence factor can effectively correct the high prediction value of the mechanistic model under the influence of corrosion product film, improve the accuracy and applicability of corrosion prediction, and provide important theoretical guidance for the design, manufacturing, operation and maintenance of oil and gas production pipelines and related facilities.

The hydrothermal performance and corrosion resistance of MgO@Nb2O5 composite coatings on Mg–7Y alloy in natural seawater

MgO@Nb2O5 composite coating was prepared on the surface of Mg–7Y alloy by micro-arc oxidation technique. The microstructure of the composite coatings was tested by scanning electron microscopy, energy spectrum analysis, X-ray diffraction and scanning kelvin probe force microscope. The hydrothermal performance and corrosion resistance of MgO@Nb2O5 composite coatings were analyzed by electrochemistry tests and laser confocal. The results showed that microspore diameter, porosity and roughness of the composite coatings were all decreased with the increasing of Nb2O5 concentration. The micro-arc oxidation composite coatings were mainly composed of MgO and Nb2O5. Compared with the micro-arc oxidation coating without Nb2O5, the corrosion voltage of the micro-arc oxidation coating with Nb2O5 was increased and the corrosion current was reduced. The corrosion resistance of Mg–7Y alloy was effectively improved by the MgO@Nb2O5 composite coatings, and the best corrosion resistance of the micro-arc oxidation coating was achieved when the Nb2O5 concentration was 2 g/L. The hydrothermal test demonstrated that the hydrothermal resistance of the coatings was significantly improved due to the addition of Nb2O5.

НАУЧНЫЙ АНАЛИЗ ФИОЛЕТОВОГО ВОСЬМИУГОЛЬНОГО СТОЛБЧАТОГО ИЗДЕЛИЯ, НАЙДЕННОГО НА МОГИЛЬНИКЕ ХЭЦЗЯ, СЯНЬЯН, ШЭНЬСИ, И СВЯЗАННЫЕ С ЭТИМ ВОПРОСЫ

In this paper, we chose late war purple octagonal prismatic ware excavated at the Hejia Cemetery in Xianyang as the object of study, and carried out scientific analysis using ultra-deep field microscopy, scanning electron microscopy and energy spectrum analysis, X-ray diffraction, and microscopic Raman spectroscopy. First of all, the features of the formation and weathering process were determined, then the samples of unweathered areas obtained by the sectioning method were examined, and it was confirmed that all 12 samples are barium copper silicate with the main phases of Chinese violet (BaCuSi2O6) and Chinese dark blue (BaCu2Si2O7) colors. Based on compositional characteristics, etc. it was also found that this group of purple octagonal vessels embodies two different manufacturing processes and may represent an evolution of the process from lead-barium glass to cupro-barium silicate. On this basis, issues such as the population, distribution area and functional characteristics of this type of dish are discussed in order to obtain new ideas and evidence for relevant research.

Development of an areal density imaging for boron and other elements

Boron areal densities in pure boron samples were determined using energy-resolved neutron measurements. For non-destructive measurement of boron content, the neutron-energy spectrum was measured with prompt γ-ray activation analysis. It was confirmed that the areal density of samples could be measured with 1% to 10% accuracy for high boron content by neutron energy spectrum analysis. The viability of this analysis is also discussed compared with the traditional quantitative analysis.

Loess microstructure indication indexes for the study of palaeoclimatic conditions in northwest China

AbstractThe Loess Plateau of China, located to the west of the Liupan Mountains and north of the Qinling Mountains stretching across the Yellow River, is the main loess deposit area in Northwest China. The loess in the northwest of China has deposits with large thickness and extensive distribution. Scanning electron microscopy (SEM) and energy spectrum analysis of loess have been performed to study the relationship between the loess microstructures and the forming climates Era. The relevant indexes were evaluated including the sand‐dropping speed (Vn), certain sedimentary depths (hn sand particle volume (Vd) and element ratios of Ca/Fe, K/Al, Si/Al and Ca/Mg. The microstructure indexes of loess accumulation and evolution reflect paleoclimate conditions and time scales to a certain extent. The important discovery is the microscopic sand‐dropping speed (Vn) and the sedimentary depth hn) calculation method of different sedimentary ages. These indices are compared with the record of major aeolian‐forming climates from the Guliya ice core, and provide a reliable benchmark for studying climate change It also can be used as important indicators of monsoonal change and environmental evolution reconstruction. The index of sand sedimentation speed (Vn) got from loess microstructure could reflect sand‐dropping speed and loess deposition course. According the article can serve as new indicators of climatic changes of different forming loess layers. It can also be concluded that the climatic indexes obtained from loess microstructure can reflect climate conditions of loess forming. The loess forming climatic parameters are synchronous correspond to Tengger Desert and Guliya ice core for studying climate change, then microscopic parameters can also be used for preliminary analysis of loess climate formation and has be found corresponding evidence, and the loess climatic parameters correspond to the other two indexes. The analysis of loess microstructure indexes is very useful in researching climate change. Loess microstructure indexes can find new indicators and information about the monsoon climate evolution and paleoclimate changes.

Evolution Behavior and Fracture Criterion of Carbides in D2 Cold‐Work Die Steel During Hot Working Process

Investigating the fracture mechanisms of carbides is of paramount importance for optimizing hot working processes in die steels. This work establishes a comprehensive criterion equation to predict the behavior of carbide fracture in D2 cold‐work die steel during hot working process. High‐temperature laser confocal microscope is employed to prepare samples with varying solidification rates. Subsequently, these samples are subjected to a range of heating temperatures spanning from 1000 °C and 1100 °C. The samples are analyzed utilizing scanning electron microscopy energy spectrum analysis and X‐ray diffraction. The activation energy of M7C3 carbides is calculated through the utilization of kinetic equations and the Arrhenius law. Additionally, a criterion model for the fracture behavior of M7C3 carbides in D2 cold‐work die steel is established. The results reveal that thin hollow rod‐shaped carbide is easy to fracture. Moreover, the activation energy for phase transition of M7C3 carbides in D2 cold‐work die steels is determined to be 226.974 KJ mol−1. Furthermore, the fracture behavior of carbides in D2 cold‐work steel is found to be influenced by various factors such as heating temperature, deformation rate, and peak stress. Finally, the criterion model demonstrates substantial agreement with the experimental observations gathered, affirming its reliability and accuracy.

Uranium Occurrence State and Its Implication for Sandstone-Type Uranium Mineralization within the Hanbazhai Area of the Longchuanjiang Basin, China

The Mangbang Formation in the Hanbazhai area is part of the uranium ore field in the Longchuanjiang Basin, China. Uraniferous sandstones from this formation are examined in this study. The type and mode of occurrence of uranium are investigated in detail using an experiment for the sequential extraction of uranium, as well as an electron probe, scanning electron microscopy, and energy spectrum analyses. The sequential extraction experiment indicates that the proportion of uranium minerals is significantly greater than that of the adsorbed uranium in the samples, with the latter being largely present in framboidal pyrites and clay minerals. The results show that these uranium minerals are mainly composed of coffinite and uranium phosphosilicates, which closely coexist with framboidal pyrites, carbon debris, feldspar minerals, and clay minerals. The discovery of coffinite and uranium phosphosilicates is discussed in context with their symbiotic relationship and geochemical environment. Uraniferous sandstones are considered to have undergone at least two stages of mineralization: the sedimentary–diagenetic stage and the later uranium enrichment by fluid. The geochemical environment of the sedimentary–diagenetic stage is generally a sulfide-reducing environment, and the later fluids are rich in U, Si, P, and Y.

Electrochemical synthesis of Co–Pr intermetallic compounds by the co-reduction of Co(II) and Pr(III) ions in a molten LiCl–KCl eutectic

For effective recovery of the fission element Pr from spent nuclear fuel (SNF) by using molten salt electrolysis technology, the electrochemical behavior of Pr(III) on inert Mo electrode in the molten LiCl–KCl system was investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques, indicating that the reduction of Pr(III) on the Mo electrode is a one-step reaction process with three electrons. Subsequently, electrochemical methods were used to reveal and calculate the kinetic and thermodynamic parameters of the Pr(III) ion reduction process. The co-reduction reaction of Pr(III) and Co(II) ions was explored, and five different CoxPry intermetallic compounds were detected. Meanwhile, only one Co2Pr intermetallic compound was obtained by galvanostatic and potentiostatic electrolysis with the best electrochemical parameters, and the thermodynamic properties of the Co2Pr intermetallic compound were calculated at different temperatures. The co-reduction product was verified using X-ray diffraction (XRD), and the composition was determined by scanning electron microscopy (SEM) with energy spectrum analysis (EDS) and X-ray photoelectron spectroscopy (XPS). In addition, the produced Co2Pr intermetallic compound has magnetic properties with a saturation magnetization of 10.3 emu/g.

Cause Analysis of Leakage Failure of Seamless Steel Pipe during Pipeline Pressure Test

By means of chemical analysis, tensile test, metallographic analysis, and energy spectrum analysis, the leakage causes of seamless steel pipe in the process of pipeline pressure test were analyzed. The analysis shows that the crack of steel pipe appears before rolling, and the non-metallic inclusions near the crack are the crack source or preferred path of steel pipe cracking. The leakage of steel pipe defects in the subsequent eddy current and ultrasonic inspection is one of the main reasons the unqualified steel pipe flows into the construction site and leads to the leakage of the pressure test.

A study on the collapse characteristics of loess based on energy spectrum superposition method

Mineral types form the basis for studying the structural stability of loess, and identifying mineral types at the microscopic scale has always been a difficult task. Identifying mineral types at the microscopic scale is very helpful in understanding the differential role that different minerals play in the structural stability of loess, and it can also clarify the specific mineral changes that occur during the process of humidification and dehumidification. Using an innovative energy spectrum superposition method, this article combines backscattered electron imaging and X-ray energy spectrum analysis results to achieve direct identification of the eight main minerals in loess, including quartz, illite, and chlorite, within SEM images. The mineral identification results provide a basis for statistical analysis of mineral water sensitivity and morphological changes under wetting conditions. The results demonstrate that chlorite and hematite, which account for no more than 23% of the loess composition, play a crucial role in binding. Furthermore, these minerals exhibit significant hydrolysis phenomena. Particularly, the intense decomposition of chlorite leads to the displacement of non-binding quartz and feldspar particles, thereby altering the pore structure of loess. These findings are of great significance in understanding the multi-level collapsibility of loess.

Electrospun Carboxymethyl Cellulose/Polyvinyl Alcohol Nanofiber Membranes for Enhanced Metal Ion Removal

Carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) composite nanofiber membranes were prepared by electrostatic spinning, using CMC and PVA as raw materials and glutaraldehyde as a cross-linking agent. The structure, morphology, thermal stability, and filtration performance of CMC/PVA nanofiber membranes were characterized by advanced instrumental analysis methods such as scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, ultraviolet analysis, and energy spectrum analysis. The results show that the average fiber diameter decreases from 381 nm to 183 nm when the spinning voltage is 23 KV and the jet speed is 2 µL/min. The obtained fiber has the smallest particle size and the most uniform distribution. Infrared spectroscopy analysis confirms that the adsorption behavior of nanofiber membranes on Cu2+ and Cr6+ is chemical adsorption. The retention rates of CMC/PVA nanofiber membranes for Cu2+ and Cr6+ reached 97.2% and 98.8%, respectively. The adsorption capacities of Cu2+ and Cr6+ were 26.34 and 28.93 mg·g−1, respectively. The adsorption of heavy metal ions by nanofiber membranes can be explained by the pseudo-second-order kinetic mechanism of the chemisorption process and the Langmuir isotherm model.

Failure Analysis of High-Pressure Turbine Blades in Steam Power Plants

This paper describes the failure of high-pressure steam turbine blades. During the Serious Inspection, it was discovered that the ninth-stage high-pressure turbine blade had failed. The causes of blade failure are examined via visual inspection and destructive testing. The failure mechanism of the blades was determined by conducting mechanical properties testing, metallographic inspection, and energy spectrum analysis. The mechanical properties of the leaf and root blade specimens were within the range of blade steel for steam turbines according to the Chinese National Standard (GB/T 8732-2004), but the chemical composition was not identical. This is consistent with the root blade fracture pattern where the hardness value plotted from the test results is the lowest at the root blade location, which is the primary cause of fissure propagation.

Effect and mechanism of DC magnetic field combined with calcium chloride on saltiness and flavor enhancement of low salt pork gel

This study intended to investigate the synergistic effect of direct current magnetic field (DC-MF) and calcium chloride (CaCl2) on improving the saltiness and quality of pork gel and to explore the potential adjustment mechanisms involved. Pork mince was subjected to low-salt treatment of DC-MF for 3 h (T1), CaCl2 substitution (T2) or DC-MF combined with CaCl2 (T3) respectively under high and low salt controls (HC and LC). Heat-induced gels of pork mince were prepared and analyzed in terms of gel texture, saltiness perception, moisture status, salt release and protein structure. Results indicated that DC-MF combined with CaCl2 treatment could reduce the addition of sodium chloride by 5% while maintaining the saltiness and overall acceptability of mince as well as improving its texture and yield. Further studies revealed that DC-MF in concert with CaCl2 treatment could not only increase the moisture content of mince gel, but also enhance saltiness perception by causing gel matrix to release salt-bearing juices under external forces. The energy spectrum analysis also illustrated that co-treatment technique could avoid the salt loss of minced meat during cooking process. Finally, a possible potential regulatory mechanism was speculated that the synergistic action of DC-MF and CaCl2 could alter the gel texture and sodium salt availability by modifying protein conformation and inducing a competitive binding reaction site for calcium and sodium ions. In conclusion, synergistic treatment by DC-MF and CaCl2 was a potential strategy in meat salt reduction.

Dodecane/Silica Phase Change Microcapsules: Fabrication, Structure and Stability

With the growing concern for energy and environmental issues, phase change materials are increasingly being recognized as a promising and eco-friendly energy storage material. However, the application of solid-liquid phase change materials is hindered by leakage issues. One effective solution to this issue is the fabrication of phase change microcapsules by encapsulating phase change materials. In this study, we designed and prepared phase change microcapsules composed of dodecane core and silica shell via interfacial polymerization, utilizing tetraethyl orthosilicate as the silicon source. The microstructure, composition, phase change properties and thermal stability of the microcapsules were analyzed using various techniques such as scanning electron microscopy, infrared spectroscopy, energy spectrum analysis, differential scanning calorimetry and thermogravimetric analysis. The findings revealed that the microcapsules had good microscopic morphology and uniform particle size of about 300–400 nm when the core–shell mass ratio was 5:5. Moreover, these microcapsules exhibited excellent phase change function and thermal stability.

High-efficiency cleaning technology and lifespan prediction for the ceramic membrane treating secondary treated effluent.

Chemical cleaning is one of the key technical means to control membrane fouling, restore membrane flux and ensure the stable operation of membrane systems. In the experiment, the six most representative chemical cleaning agents for ceramic membranes, such as sulfuric acid (H2SO4), sodium hydroxide (NaOH), sodium hypochlorite (NaClO), ethylenediaminetetraacetic acid disodium salt (EDTA-Na2), sodium dodecyl sulfate (SDS) and nonylphenol polyoxyethylene ether (OP-10), were used as research objects. The cleaning effect of the two-step combined cleaning of chemical cleaning agents on the fouled membrane was systematically investigated. Results showed that the order of the chemical cleaning agent had a significant effect on the cleaning effect. The best chemical cleaning program was determined to be NaClO first and then SDS: the fouled ceramic membrane was soaked in NaClO solution at 0.15% for 2.5 h and further soaked in SDS solution at five times its own critical micelle concentration for 2.5 h. The predicted long-term lifespan of the ceramic membranes was 4.91 years. Scanning electron microscopy-energy spectrum analysis showed that the surface roughness of the cleaned ceramic membrane was slightly higher than that of the new membrane. The contact angle was slightly lower than that of the new membrane.

Research on Oxygenation Components under a High-Pressure Oxygen Environment

Oxygen nozzles play an important role in aircraft oxygen systems, and the oxygen valve is one of the most important components of the oxygen nozzle. In order to investigate the ignition source of three fires of a certain type of aircraft, combustion analysis, energy spectrum analysis, and material analysis were conducted. Based on the results of the analysis, oxygen impact tests were carried out under different conditions to identify the superior material and to calculate the lifetime of a PA1010 oxygen valve. The test platform was constructed at the National Key Experimental Base of Fire Science. The PA1010 oxygen nozzle and the F3 oxygen nozzle were the main test subjects. The test results show that the lifetime of the PA1010 oxygen valve under high-pressure oxygen was about 2532, and F3 was the safer material for the oxygen valve. This research provides a reference for the safety design of oxygen valves under high-pressure environments and facilitates further research into aircraft oxygen systems.

Investigation of Optical Properties and Activity of Wheat Stripe Rust Urediospores

Stripe rust is one of the most common diseases challenging the safe production of wheat. Rapid identification and analysis of urediospores, responsible for disease transmission, are the key to preventing and controlling stripe rust. The current spore detection is time-consuming and requires auxiliary equipment, but many optical detection methods and sensors with high efficiency, sensitivity, and detection ability have been developed and widely used. Thus, the investigation of optical parameters is the prerequisite for optical sensitive detection and is detailed in this study. Firstly, the microscopic images and surface elements of wheat stripe rust urediospores were obtained using a high-resolution electron microscope and an energy spectrum analyzer. The reflectivity and absorptivity spectra in the near-infrared band of active/inactivate urediospores were measured. Further, the optical parameters, such as reflection phase shift, complex refractive index, and dielectric constant, of the urediospores were analyzed based on electromagnetic theory and Kramers–Kronig relation. The results revealed that the urediospores have a strong tolerance to near-infrared light, and the real part of the complex refractive index n was between 1.0 and 1.4. These observations indicate that whether the spores are active or not has little effect on the real part and dielectric constant of the complex refractive index but has a significant impact on the imaginary part and extinction coefficient of the complex refractive index, and the corresponding relationship between the optical properties of urediospores and biological components was established. These findings were verified with HPLC-MS and Near-Infrared Spectroscopy Analysis Technology and lay a theoretical foundation for detecting urediospores of wheat stripe rust by using optical sensors. The study provides a reference for the analysis of optical characteristics of other biological samples.

Experimental and Numerical Study on Deflagration Characteristics of Large-Scale Propane-Air Mixture.

Seven deflagration tests of a propane-air mixture were carried out in a 22.5 m3 large-scale chamber. The effects of initial volume, gas concentration, and initial turbulence intensity on deflagration characteristics were analyzed. The main frequency of the explosion wave was quantitatively determined by the combination of the wavelet transform and energy spectrum analysis. The results show that the explosive overpressure is formed by the discharge of combustion products and secondary combustion, and the effects of turbulence and gas concentration on the explosive overpressure are higher than the initial volume. Under the condition of weak initial turbulence, the main frequency of gas explosion wave is between 32.13 and 48.33 Hz. Under strong initial turbulence conditions, the main frequency of the gas explosion wave increases with the increase of overpressure, and the empirical formula of the relationship between the main frequency and overpressure is summarized, which could provide theoretical support for the design of mechanical metamaterials for oil and gas explosion. Finally, the flame acceleration simulator numerical model was calibrated through tests, and the overpressure simulation values were in good agreement with the experimental data. The leakage, diffusion, and explosion of a liquefied hydrocarbon loading station in a petrochemical enterprise were simulated. The lethal distance and explosion overpressure at key buildings are predicted for different wind speed conditions. The simulation results can provide a technical basis for evaluating personnel injury and building damage.

Adsorption Characteristics and Mechanism of Ammonia Nitrogen in Water by Nano Zero-valent Iron-modified Biochar

The adsorption performances of ammonia nitrogen (NH+4-N) in water by unmodified biochar are ineffective. In this study, nano zero-valent iron-modified biochar (nZVI@BC) was prepared to remove NH+4-N from water. The NH+4-N adsorption characteristics of nZVI@BC were investigated through adsorption batch experiments. The composition and structure characteristics of nZVI@BC were analyzed using scanning electron microscopy, energy spectrum analysis, BET-N2 surface area (SSA), X-ray diffraction, and FTIR spectra to explore the main adsorption mechanism of NH+4-N by nZVI@BC. The results showed that the composite synthesized at the iron to biochar mass ratio of 1:30 (nZVI@BC1/30) performed well in NH+4-N adsorption at 298 K. The maximum adsorption amount of nZVI@BC1/30 at 298 K was remarkably increased by 45.96% and reached 16.60 mg·g-1. The pseudo-second-order model and Langmuir model fitted well with the adsorption process of NH+4-N by nZVI@BC1/30. There was competitive adsorption between coexisting cations and NH+4-N, and the sequence of coexisting cations to the adsorption of NH+4-N by nZVI@BC1/30 was Ca2+> Mg2+> K+> Na+. The adsorption mechanism of NH+4-N by nZVI@BC1/30 could be mainly attributed to ion exchange and hydrogen bonding. In conclusion, nano zero-valent iron-modified biochar can improve the adsorption performance of NH+4-N and enhance the application potential of biochar in the field of nitrogen removal from water.